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by priyasaravanan_1406 at 11-26-2012, 09:41 PM
1 comments
Metals possess wide range of applications from domestic to industrial use. Inspite of its toxic nature and effect on exposure of various metals few metals are very essential for the human body to carry out normal biological functions. The significant elements playing a vital role in influencing biological process are Chromium(III), cobalt, copper, Iron, Magnesium, Manganese, Molybdenum, selenium, vanadium, tantalum and zinc.
Chromium(III): The recommended daily intake of this element is 0.06mg and the dietary chromium(III) is involved in the metabolism of lipids and sugars. Chromium is widely used in paint industry, fabrication industries and in leather industry for tanning. The industrial exposure to compounds of chromium is found to cause skin ulcers, perforations in the nasal area and inflammation of liver and larynx. The target organ of chromium is the respiratory tract, central nervous system (CNS), liver, skin and kidney.
Cobalt: Key element of vitamin B12 and the recommended daily dietary intake is 0.3mg. Cobalt is generally obtained as a by product from different metals and is widely used in salt form as catalyst in paint industry to enhance the activities like drying of paints and to produce pigments. Excess intake of cobalt results in a condition called polycythemia and the target organs of cobalt are the GI tract, respiratory tract, CNS, cardio vascular system, skin and endocrine.
Copper: Plays a vital role in oxygen transport and influences the uptake of iron by the body and also involved in biological process by transporting electrons. The recommended daily dietary intake is 3.2mg. Copper is widely used metal in industries and its salts posses antibacterial and antifungal properties. The sensitivity to copper toxicity is less in humans but the oral intake of copper in its salt form may even be fatal. Blood and GI tract are the target sites of copper.
Iron: Significant element for the production of hemoglobin and also aides oxygen transport with daily dietary intake of 15mg. Iron as a metal is widely used in the steel industry for fabrication. Iron toxicity is either acute or chronic. Hemochromatosis is the condition arising as a result of chronic iron poisoning. The target systems of iron are the GI tract, respiratory tract, CNS, liver, blood and endocrine.
Manganese: Manganese is a significant element required for good bone health and structure. The recommended daily dietary intake of manganese is 5mg. Manganese as such and its derivatives are used in manufacturing steel alloys, batteries, coils, glass and many other applications. The target sites of manganese are the respiratory tract and CNS. The acute manganese poisoning as a result of inhalation affects the respiratory system whereas the chronic toxicity affects the central nervous system.
Magnesium: Being a co-factor for different enzymes catalyzing various biochemical reactions and important element in energy production the recommended daily dietary intake of magnesium is 500mg. The major industrial application of magnesium is in manufacturing alloys. Inhalation of the oxide form of magnesium causes metal fume fever. The target organ of magnesium is the central nervous system.
Molybdenum: The recommended daily intake of molybdenum is 0.35mg. The multiple functions of molybdenum involves energy production, maintaining the function of kidney by processing the water and participation in the biologic phenomenon of the nervous system. Molybdenum finds its way into industries producing lubricants and catalysts and it is also used in manufacturing temperature resistant steel alloys. Molybdenum toxicity in humans is not evident. The target organs of molybdenum are the liver, blood, kidney and bone.
Selenium: Selenium is considered as a good antioxidant protecting cells from free radicals and also important element for a good immune system. The recommended daily dietary intake of selenium is 0.06 to 0.15mg. Selenium finds its way into industries manufacturing electronic items, ceramic and steel industries and chemical industry. Acute toxicity of selenium causes damage to the central nervous system and chronic toxicity is exhibited by GI tract disorders, smell in the breath, anemia, damage to spleen and pain in the lumbar region. Selenium is also classified as teratogen. GI tract, CNS, skin and liver are the target sites of selenium.
Vanadium: Vanadium takes care of the blood vessels by protecting them by blocking or inhibiting the formation of cholesterol. It is involved in energy production and metabolism of fat as well. The recommended daily intake of vanadium is 2.5mg. Vanadium is used in the process of steel making, pigment production and also in the production of insecticides. Bronchitis and bronchopneumonia are the conditions upon exposure to vanadium. Also effects on GI tract, skin and tongue is noticed. The target organs of vanadium are the respiratory tract, CNS, skin and kidney.
Zinc: Zinc is the most important element participating in cell division and growth. Zinc is also considered as a vital factor in fertility. Zinc has an affinity for immune system, hair, nails and skin and enhances them. Zinc can also be mentioned as an elemental factor in gene expression. The recommended daily intake is about 12mg. Zinc is used in manufacturing various products like paint, rubber, preservatives of wood, paper and glass. The metal fume fever on inhaling zinc oxide and skin toxicity on exposure to zinc chloride are some of the effects of zinc compounds. Zinc targets the GI tract, blood and the bone.
Thus the significance of the dietary elements and the occupational hazards of the same elements has been explained.
Chromium(III): The recommended daily intake of this element is 0.06mg and the dietary chromium(III) is involved in the metabolism of lipids and sugars. Chromium is widely used in paint industry, fabrication industries and in leather industry for tanning. The industrial exposure to compounds of chromium is found to cause skin ulcers, perforations in the nasal area and inflammation of liver and larynx. The target organ of chromium is the respiratory tract, central nervous system (CNS), liver, skin and kidney.
Cobalt: Key element of vitamin B12 and the recommended daily dietary intake is 0.3mg. Cobalt is generally obtained as a by product from different metals and is widely used in salt form as catalyst in paint industry to enhance the activities like drying of paints and to produce pigments. Excess intake of cobalt results in a condition called polycythemia and the target organs of cobalt are the GI tract, respiratory tract, CNS, cardio vascular system, skin and endocrine.
Copper: Plays a vital role in oxygen transport and influences the uptake of iron by the body and also involved in biological process by transporting electrons. The recommended daily dietary intake is 3.2mg. Copper is widely used metal in industries and its salts posses antibacterial and antifungal properties. The sensitivity to copper toxicity is less in humans but the oral intake of copper in its salt form may even be fatal. Blood and GI tract are the target sites of copper.
Iron: Significant element for the production of hemoglobin and also aides oxygen transport with daily dietary intake of 15mg. Iron as a metal is widely used in the steel industry for fabrication. Iron toxicity is either acute or chronic. Hemochromatosis is the condition arising as a result of chronic iron poisoning. The target systems of iron are the GI tract, respiratory tract, CNS, liver, blood and endocrine.
Manganese: Manganese is a significant element required for good bone health and structure. The recommended daily dietary intake of manganese is 5mg. Manganese as such and its derivatives are used in manufacturing steel alloys, batteries, coils, glass and many other applications. The target sites of manganese are the respiratory tract and CNS. The acute manganese poisoning as a result of inhalation affects the respiratory system whereas the chronic toxicity affects the central nervous system.
Magnesium: Being a co-factor for different enzymes catalyzing various biochemical reactions and important element in energy production the recommended daily dietary intake of magnesium is 500mg. The major industrial application of magnesium is in manufacturing alloys. Inhalation of the oxide form of magnesium causes metal fume fever. The target organ of magnesium is the central nervous system.
Molybdenum: The recommended daily intake of molybdenum is 0.35mg. The multiple functions of molybdenum involves energy production, maintaining the function of kidney by processing the water and participation in the biologic phenomenon of the nervous system. Molybdenum finds its way into industries producing lubricants and catalysts and it is also used in manufacturing temperature resistant steel alloys. Molybdenum toxicity in humans is not evident. The target organs of molybdenum are the liver, blood, kidney and bone.
Selenium: Selenium is considered as a good antioxidant protecting cells from free radicals and also important element for a good immune system. The recommended daily dietary intake of selenium is 0.06 to 0.15mg. Selenium finds its way into industries manufacturing electronic items, ceramic and steel industries and chemical industry. Acute toxicity of selenium causes damage to the central nervous system and chronic toxicity is exhibited by GI tract disorders, smell in the breath, anemia, damage to spleen and pain in the lumbar region. Selenium is also classified as teratogen. GI tract, CNS, skin and liver are the target sites of selenium.
Vanadium: Vanadium takes care of the blood vessels by protecting them by blocking or inhibiting the formation of cholesterol. It is involved in energy production and metabolism of fat as well. The recommended daily intake of vanadium is 2.5mg. Vanadium is used in the process of steel making, pigment production and also in the production of insecticides. Bronchitis and bronchopneumonia are the conditions upon exposure to vanadium. Also effects on GI tract, skin and tongue is noticed. The target organs of vanadium are the respiratory tract, CNS, skin and kidney.
Zinc: Zinc is the most important element participating in cell division and growth. Zinc is also considered as a vital factor in fertility. Zinc has an affinity for immune system, hair, nails and skin and enhances them. Zinc can also be mentioned as an elemental factor in gene expression. The recommended daily intake is about 12mg. Zinc is used in manufacturing various products like paint, rubber, preservatives of wood, paper and glass. The metal fume fever on inhaling zinc oxide and skin toxicity on exposure to zinc chloride are some of the effects of zinc compounds. Zinc targets the GI tract, blood and the bone.
Thus the significance of the dietary elements and the occupational hazards of the same elements has been explained.
by bvs science freak at 11-25-2012, 02:47 AM
2 comments
Hi,
I believe that becoming a mastery in a particular subjects of life science and Non-Life science subjects can help me acquire a great knowledge to become a successful researcher in the field of life science.
My Favourite inter-disciplines or life science studies are:
Genetic Engineering
Microbiology
Immunology
Pharmaceutical Biotechnology
Cell biology
Molecular biology
Biochemistry
Tissue culture studies
Nano biotechnology and
Ayurvedic/siddha/Indian traditional medicines.
I've a hope and confidence that i can surely become a master in biotechnology by doing M.Sc.Biotechnology and Phd in genetic engineering can give a mastery knowledge in GE.
But i don't know how to enrich myself in remaining subjects or don't know how to acquire a mastery in other disciplines..
My thought's may be stupid.But help me How to approach or to work to acquire broad knowledge in all those subjects..
Plz ..I'll be very helpful if any one can show a right path..
Plz..Help me by giving what ever suggestions,I'm ready to work hard..
I believe that becoming a mastery in a particular subjects of life science and Non-Life science subjects can help me acquire a great knowledge to become a successful researcher in the field of life science.
My Favourite inter-disciplines or life science studies are:
Genetic Engineering
Microbiology
Immunology
Pharmaceutical Biotechnology
Cell biology
Molecular biology
Biochemistry
Tissue culture studies
Nano biotechnology and
Ayurvedic/siddha/Indian traditional medicines.
I've a hope and confidence that i can surely become a master in biotechnology by doing M.Sc.Biotechnology and Phd in genetic engineering can give a mastery knowledge in GE.
But i don't know how to enrich myself in remaining subjects or don't know how to acquire a mastery in other disciplines..
My thought's may be stupid.But help me How to approach or to work to acquire broad knowledge in all those subjects..
Plz ..I'll be very helpful if any one can show a right path..
Plz..Help me by giving what ever suggestions,I'm ready to work hard..
by BojanaL at 11-24-2012, 03:24 AM
1 comments
There has been a lot of research on artificial retina and stem cell treatments to restore normal human level vision.
Thanks to the complex sensory system we can hear, smell, see, feel and taste the world around us. Each sense is important and has unique anatomy that can help us modify our behavior and adapt to the environmental changes. When one of the senses is damaged, remaining senses intensify their function (blind people hear better than people with normal vision). Sight can be impaired in numerous ways. Due to complicated anatomy of eye and associated neuronal connections, development of a device that could help restore damaged vision is truly a challenge. Luckily, advanced technology allowed scientists to design couple of prototypes that will soon become available for a worldwide use.
Eye is the central organ for the sense of vision. Retina is photosensitive part of the eye; it consists of the rods and cones (modified neuronal cell) that are responding to the light by generating action potential that is traveling through the optic nerve (formed by the retinal ganglion axons) to the visual cortex where image will finally be created. Blindness is usually associated with retinal damage, either as a consequence of an accident or as a result of diseases like macular degeneration, retinitis pigmentosa, cone-rod dystrophy…..
Two types of retinal devices are currently under investigation.
Epiretinal device consists of internal and external part. Silicon platinum electrode array (internal part) is placed on the inner surface of the retina. External part of the device consists of glasses containing miniature camera. Images captured by camera are wirelessly sent back to antenna in the inner electrode array. Electric impulses from the array will trigger remaining retinal cells and generate electric signal (visual information) that will travel to the brain via optic nerve. Patients need to learn how to interpret visual patterns. Disadvantage: external part of the device can be bulky and patient needs to move head to “update” visual information. Also, internal part needs to fit perfectly to prevent disturbance of the nearby axons (it can be fixed to the retina using miniature tacks). Epiretinal device finished clinical trials successfully; soon it will become available in couple of European countries.
Subretinal device is placed on the surface of the retina, between retinal photosensitive cells and retinal pigment layer. This prototype stimulates retinal cells directly. It consists of silicon pad containing light sensitive micro-photodiodes. Electric signal, generated by light, passes to the retinal cells and further to the brain. This device doesn’t need external apparatus, but it requires power supply to amplify up-coming light signals, which is the main disadvantage of the subretinal device. Problem could be solved using the artificial cells able to generate electricity. Experiments of that kind were conducted couple years ago, when group of scientists wanted to design artificial cell using eel’s electrocyte as a cell model. Eel use electrocytes to stun the prey, but they are also important for detection of various stimulus. Biochemistry behind the cell electricity is relatively simple. Cell voltage and electric current are associated with ion channels activity. Exchange of sodium and potassium currents over the cell membrane alter the cell voltage and trigger electric current. Electrocytes act like a nervous cells - initial signal travels fast and it is easily transferred to the next cell. Different types of ion channels will be more or less densely distributed along the cell membrane (depending on their function). Electric eel can generate up to 600 volts of electricity thanks to thousand of simultaneously firing electrocytes. Scientists wanted to investigate what are the main ion channels and find a way to increase produced electricity by altering their functions. Using the software, numerical design optimization method was applied to investigate which channels produce electricity under which circumstances. After main channels were detected, scientists enhanced their activity and ended up with the cell that could produce 40% more electricity than electrocyte in the natural environment. This type of cells could serve as bio-battery. Using 4 mm wide layer of electrocytes, 300 microwatts of electricity was generated. That amount of electricity would be enough for various implanted micro-devices, including retinal device. Artificial cell is still under investigation.
Although described devices are still not available (at least not everywhere), nor they are perfect, blind people are closer than ever to regain their sight.
Related Video's from Youtube - Copyright respective owners
Thanks to the complex sensory system we can hear, smell, see, feel and taste the world around us. Each sense is important and has unique anatomy that can help us modify our behavior and adapt to the environmental changes. When one of the senses is damaged, remaining senses intensify their function (blind people hear better than people with normal vision). Sight can be impaired in numerous ways. Due to complicated anatomy of eye and associated neuronal connections, development of a device that could help restore damaged vision is truly a challenge. Luckily, advanced technology allowed scientists to design couple of prototypes that will soon become available for a worldwide use.
Eye is the central organ for the sense of vision. Retina is photosensitive part of the eye; it consists of the rods and cones (modified neuronal cell) that are responding to the light by generating action potential that is traveling through the optic nerve (formed by the retinal ganglion axons) to the visual cortex where image will finally be created. Blindness is usually associated with retinal damage, either as a consequence of an accident or as a result of diseases like macular degeneration, retinitis pigmentosa, cone-rod dystrophy…..
Two types of retinal devices are currently under investigation.
Epiretinal device consists of internal and external part. Silicon platinum electrode array (internal part) is placed on the inner surface of the retina. External part of the device consists of glasses containing miniature camera. Images captured by camera are wirelessly sent back to antenna in the inner electrode array. Electric impulses from the array will trigger remaining retinal cells and generate electric signal (visual information) that will travel to the brain via optic nerve. Patients need to learn how to interpret visual patterns. Disadvantage: external part of the device can be bulky and patient needs to move head to “update” visual information. Also, internal part needs to fit perfectly to prevent disturbance of the nearby axons (it can be fixed to the retina using miniature tacks). Epiretinal device finished clinical trials successfully; soon it will become available in couple of European countries.
Subretinal device is placed on the surface of the retina, between retinal photosensitive cells and retinal pigment layer. This prototype stimulates retinal cells directly. It consists of silicon pad containing light sensitive micro-photodiodes. Electric signal, generated by light, passes to the retinal cells and further to the brain. This device doesn’t need external apparatus, but it requires power supply to amplify up-coming light signals, which is the main disadvantage of the subretinal device. Problem could be solved using the artificial cells able to generate electricity. Experiments of that kind were conducted couple years ago, when group of scientists wanted to design artificial cell using eel’s electrocyte as a cell model. Eel use electrocytes to stun the prey, but they are also important for detection of various stimulus. Biochemistry behind the cell electricity is relatively simple. Cell voltage and electric current are associated with ion channels activity. Exchange of sodium and potassium currents over the cell membrane alter the cell voltage and trigger electric current. Electrocytes act like a nervous cells - initial signal travels fast and it is easily transferred to the next cell. Different types of ion channels will be more or less densely distributed along the cell membrane (depending on their function). Electric eel can generate up to 600 volts of electricity thanks to thousand of simultaneously firing electrocytes. Scientists wanted to investigate what are the main ion channels and find a way to increase produced electricity by altering their functions. Using the software, numerical design optimization method was applied to investigate which channels produce electricity under which circumstances. After main channels were detected, scientists enhanced their activity and ended up with the cell that could produce 40% more electricity than electrocyte in the natural environment. This type of cells could serve as bio-battery. Using 4 mm wide layer of electrocytes, 300 microwatts of electricity was generated. That amount of electricity would be enough for various implanted micro-devices, including retinal device. Artificial cell is still under investigation.
Although described devices are still not available (at least not everywhere), nor they are perfect, blind people are closer than ever to regain their sight.
Related Video's from Youtube - Copyright respective owners
by BojanaL at 11-23-2012, 08:45 PM
0 comments
Researchers in Japan and California (Stanford, UC Irvine) have developed plastic antibodies capable of seizing and neutralizing dangerous materials in the body.
Immune system is complex set of cells, chemical signals and proteins united to target and eliminate the antigens (foreign molecules) after they enter the body. Antigens could be infective agents (like microorganisms), toxins or endogenous metabolites that should be cleared from the body. B-lymphocytes produce specifically shaped immunoglobulins (class of proteins) better known as antibodies that will bind to antigens and remove them from the organism. Bond between antigen and antibody is strong and specific: perfectly designed antibody will match antigen just like key will match certain lock. When organism is facing disease for the first time, it needs time before adequate antibody is created, but with each new infection (caused by the same pathogen) - immune response will be executed faster. Vaccination is mimicking naturally occurring pathogen attack; provoked immune system will produce antibodies against the pathogen and provide resistance against specific disease. A lot of severe infectious diseases were eradicated thanks to vaccination.
Besides vaccination, advanced technological methods allowed scientists to produce desired antibodies in laboratory using different animal species (by purifying their blood or through cellular cloning). Until recently, antibody production was exclusively associated with living creatures. Basic structure of the antibody is well known, but there is still a variable part of the protein that will change to fit each new antigen presented. In the body, one B cell lymphocyte could produce over billion different antibodies that will match and eliminate foreign substances successfully. Manually created antibodies were hard to produce without modern manufacturing techniques. Nanotechnology is already widely used and applied in various scientific fields. It proved to be useful even in the field of immunity, enabling scientists to develop first plastic antibody.
Dr. Ken Shea, Professor of the Chemistry at the University of California, designed and tested first nanotech derived antibody. Nanomaterials and nanoparticles are made out of polymers that will assemble in a predetermined way. To obtain a mold that will be used for the artificial antibody production, plastic material was placed around antigen. After antigen was removed, cavity that left behind served as pattern for plastic antibody production because it perfectly matches shape of the antigen that should be recognized and eliminated. When bigger pool of plastic antibodies was created, professor Shea start experiments with mice to test their efficacy in vivo. Mice were injected with lethal dose of bee venom. Animals that didn't receive plastic antibodies died, while 60% of immunized mice survived lethal dose of toxin. Important observation in this experiment was that plastic antibody managed to recognize circulating toxin (antigen) out of many other molecules in the blood and successfully eliminate it in 60% of animals. Besides proven selectivity, plastic antibodies have few more advantages compared to naturally derived antibodies. They are abiotic and manufacturing process doesn't require living organisms. Production is simple, faster and cheaper than conventionally applied procedure. Artificial molding of the antigen requires less time than naturally occurring recognition and response. Also, plastic antibodies could be applied in numerous ways. Dr. Shea’s laboratory is mainly focused on antidote production. Intoxication after snake or spider bite are often in the nature; some of them require fast and efficient treatment, and unfortunately, list of toxins without appropriate antidote is still long. Other promising application of plastic antibodies could be seen in protein purification and in a diagnostics field. Couple of issues needs to be solved before experiments on human start. Scientists still investigate clearance and metabolism (after binding to the antigens) of plastic antibodies. Main weak point: without naturally created antibodies, organisms will not “remember” antigen attack and it will be helpless when same antigen enters the body in the future (if artificially antibodies are not provided again). As mentioned before, adequate immune system response is dependent upon chemical signals and different type of cells that are playing complex roles while defending the body against foreign substances. Plastic antibodies couldn't communicate with the rest of the immune system and couldn't blend in cascade events typical for the immune response - they act on their own. But that doesn't mean that artificial antibodies should be rejected, they just need to be modified.
Plastic antibodies proved to have great potential and multiple applications and it is just a matter of time when they will be improved and approved for human use.
Immune system is complex set of cells, chemical signals and proteins united to target and eliminate the antigens (foreign molecules) after they enter the body. Antigens could be infective agents (like microorganisms), toxins or endogenous metabolites that should be cleared from the body. B-lymphocytes produce specifically shaped immunoglobulins (class of proteins) better known as antibodies that will bind to antigens and remove them from the organism. Bond between antigen and antibody is strong and specific: perfectly designed antibody will match antigen just like key will match certain lock. When organism is facing disease for the first time, it needs time before adequate antibody is created, but with each new infection (caused by the same pathogen) - immune response will be executed faster. Vaccination is mimicking naturally occurring pathogen attack; provoked immune system will produce antibodies against the pathogen and provide resistance against specific disease. A lot of severe infectious diseases were eradicated thanks to vaccination.
Besides vaccination, advanced technological methods allowed scientists to produce desired antibodies in laboratory using different animal species (by purifying their blood or through cellular cloning). Until recently, antibody production was exclusively associated with living creatures. Basic structure of the antibody is well known, but there is still a variable part of the protein that will change to fit each new antigen presented. In the body, one B cell lymphocyte could produce over billion different antibodies that will match and eliminate foreign substances successfully. Manually created antibodies were hard to produce without modern manufacturing techniques. Nanotechnology is already widely used and applied in various scientific fields. It proved to be useful even in the field of immunity, enabling scientists to develop first plastic antibody.
Dr. Ken Shea, Professor of the Chemistry at the University of California, designed and tested first nanotech derived antibody. Nanomaterials and nanoparticles are made out of polymers that will assemble in a predetermined way. To obtain a mold that will be used for the artificial antibody production, plastic material was placed around antigen. After antigen was removed, cavity that left behind served as pattern for plastic antibody production because it perfectly matches shape of the antigen that should be recognized and eliminated. When bigger pool of plastic antibodies was created, professor Shea start experiments with mice to test their efficacy in vivo. Mice were injected with lethal dose of bee venom. Animals that didn't receive plastic antibodies died, while 60% of immunized mice survived lethal dose of toxin. Important observation in this experiment was that plastic antibody managed to recognize circulating toxin (antigen) out of many other molecules in the blood and successfully eliminate it in 60% of animals. Besides proven selectivity, plastic antibodies have few more advantages compared to naturally derived antibodies. They are abiotic and manufacturing process doesn't require living organisms. Production is simple, faster and cheaper than conventionally applied procedure. Artificial molding of the antigen requires less time than naturally occurring recognition and response. Also, plastic antibodies could be applied in numerous ways. Dr. Shea’s laboratory is mainly focused on antidote production. Intoxication after snake or spider bite are often in the nature; some of them require fast and efficient treatment, and unfortunately, list of toxins without appropriate antidote is still long. Other promising application of plastic antibodies could be seen in protein purification and in a diagnostics field. Couple of issues needs to be solved before experiments on human start. Scientists still investigate clearance and metabolism (after binding to the antigens) of plastic antibodies. Main weak point: without naturally created antibodies, organisms will not “remember” antigen attack and it will be helpless when same antigen enters the body in the future (if artificially antibodies are not provided again). As mentioned before, adequate immune system response is dependent upon chemical signals and different type of cells that are playing complex roles while defending the body against foreign substances. Plastic antibodies couldn't communicate with the rest of the immune system and couldn't blend in cascade events typical for the immune response - they act on their own. But that doesn't mean that artificial antibodies should be rejected, they just need to be modified.
Plastic antibodies proved to have great potential and multiple applications and it is just a matter of time when they will be improved and approved for human use.
by BojanaL at 11-23-2012, 03:22 AM
0 comments
May be the food we are eating for Thanksgiving dinner is genetically modified, ex: Apples, Papayas, Potatoes and Corn.
Arctic Apples
Unique characteristic of each apple (no matter of the size, color or taste) is that slicing and peeling will change the color of the flesh. This characteristic does not make the apple inedible, but most people will find browning apples repulsive. Industry of food, dealing with sliced apples, is using different tricks to prevent apples from changing the color (like pouring vitamin C and calcium) and keep them desirable for the buyers. However, additives are not the perfect solution because they usually change the taste of the apple. Change of color is consequence of cell injury induced by cutting. Ruptured cells trigger reaction between polyphenol oxidase and chemicals in the apple that eventually alter the color of the slices. Scientists recently discovered four genes responsible for polyphenol oxidase production. Experiments showed that silencing of those 4 genes could prevent apple flesh from turning brown and soon enough, non-browning apple variety, known as arctic apple was developed. Golden Delicious and Granny Smith varieties are already modified in the “arctic apples” manner, but manufacturers are waiting for the regulatory approval before they become publically available.
Rainbow papayas
Just like any other living creature, plants are susceptible to different viral infections. ~30 years ago, Ringspot virus destroyed large portion of Hawaiian papaya fields. Only solution that could stop fast spreading of the virus was strenghtening of the plants by genetic engineering. Viral capsid proteins were inserted in the plant's genome. Similar to vaccination, this procedure boost plant’s immune system and ensure recovery of the papaya industry. Today, 80% of Hawaiian papaya is genetically modified. Tests showed that plant containing virus is not harmful for human health because viral particles undergo digestion as soon as they reach our stomach. Genetically modified papaya is available in most countries around the globe.
Potatoes
Potato is among the top 5 most cultivated plants on the planet. Roughly estimated, annual consumption of the potato is 33 kg per man. Although there are just 200 known potato species, long cultivation period and high popularity of the plant resulted in few thousand varieties available all over the world. Potato is rich in carbohydrates, vitamins, minerals, and carotenoids but conventional cooking methods destroy most of its nutritional value. Due to high carbohydrate level, excessive amount of potato in a diet can result in weight gain. Two years ago, group of Indian scientists genetically modified seven varieties of potato (that could be cultivated in different climates) by adding AmaA1 gene with the goal to increases protein content. Experiments showed that protein level could be increased up to 60% compared to non-modified plants. Also, this genetic modification increased crop yield. Nutritionally “improved” potato could help eradicate protein deficiency in the world. It is not marketed yet.
Corn
Corn (maize) is one of the oldest crops. Some evidence showed that corn was cultivated 2500 years BC. Due to widespread use, corn is genetically improved to become tolerant against insects and herbicides. In 2009, 85% of USA corn was genetically modified. Just like rice and potato, corn is staple food in the large portion of world and modifications that could increase its nutritional value are important. Vitamin E is acting like antioxidant and plays important role in pregnancy, it is recommended in cancer treatment and for prevention of the Alzheimer and Parkinson’s disease. Main sources of vitamin E are vegetable oils, nuts and seeds, but experiments showed that genetically modified corn could also be a good source of vitamin E. More complex experiment using South African variety resulted in transgenic corn rich in vitamin C, folate and beta carotene. It was shown that genetic modification could affect separate biosynthetic pathways and increase the level of three different nutrients beneficial for the human health. Vitamin enriched corn is still in experimental phase.
Whatever you are having for dinner, I hope you will spend a pleasant evening with your family and friends. Happy Thanksgiving!
Related video:
Arctic Apples
Unique characteristic of each apple (no matter of the size, color or taste) is that slicing and peeling will change the color of the flesh. This characteristic does not make the apple inedible, but most people will find browning apples repulsive. Industry of food, dealing with sliced apples, is using different tricks to prevent apples from changing the color (like pouring vitamin C and calcium) and keep them desirable for the buyers. However, additives are not the perfect solution because they usually change the taste of the apple. Change of color is consequence of cell injury induced by cutting. Ruptured cells trigger reaction between polyphenol oxidase and chemicals in the apple that eventually alter the color of the slices. Scientists recently discovered four genes responsible for polyphenol oxidase production. Experiments showed that silencing of those 4 genes could prevent apple flesh from turning brown and soon enough, non-browning apple variety, known as arctic apple was developed. Golden Delicious and Granny Smith varieties are already modified in the “arctic apples” manner, but manufacturers are waiting for the regulatory approval before they become publically available.
Rainbow papayas
Just like any other living creature, plants are susceptible to different viral infections. ~30 years ago, Ringspot virus destroyed large portion of Hawaiian papaya fields. Only solution that could stop fast spreading of the virus was strenghtening of the plants by genetic engineering. Viral capsid proteins were inserted in the plant's genome. Similar to vaccination, this procedure boost plant’s immune system and ensure recovery of the papaya industry. Today, 80% of Hawaiian papaya is genetically modified. Tests showed that plant containing virus is not harmful for human health because viral particles undergo digestion as soon as they reach our stomach. Genetically modified papaya is available in most countries around the globe.
Potatoes
Potato is among the top 5 most cultivated plants on the planet. Roughly estimated, annual consumption of the potato is 33 kg per man. Although there are just 200 known potato species, long cultivation period and high popularity of the plant resulted in few thousand varieties available all over the world. Potato is rich in carbohydrates, vitamins, minerals, and carotenoids but conventional cooking methods destroy most of its nutritional value. Due to high carbohydrate level, excessive amount of potato in a diet can result in weight gain. Two years ago, group of Indian scientists genetically modified seven varieties of potato (that could be cultivated in different climates) by adding AmaA1 gene with the goal to increases protein content. Experiments showed that protein level could be increased up to 60% compared to non-modified plants. Also, this genetic modification increased crop yield. Nutritionally “improved” potato could help eradicate protein deficiency in the world. It is not marketed yet.
Corn
Corn (maize) is one of the oldest crops. Some evidence showed that corn was cultivated 2500 years BC. Due to widespread use, corn is genetically improved to become tolerant against insects and herbicides. In 2009, 85% of USA corn was genetically modified. Just like rice and potato, corn is staple food in the large portion of world and modifications that could increase its nutritional value are important. Vitamin E is acting like antioxidant and plays important role in pregnancy, it is recommended in cancer treatment and for prevention of the Alzheimer and Parkinson’s disease. Main sources of vitamin E are vegetable oils, nuts and seeds, but experiments showed that genetically modified corn could also be a good source of vitamin E. More complex experiment using South African variety resulted in transgenic corn rich in vitamin C, folate and beta carotene. It was shown that genetic modification could affect separate biosynthetic pathways and increase the level of three different nutrients beneficial for the human health. Vitamin enriched corn is still in experimental phase.
Whatever you are having for dinner, I hope you will spend a pleasant evening with your family and friends. Happy Thanksgiving!
Related video:
by BojanaL at 11-23-2012, 03:19 AM
0 comments
Genetically modified food is becoming our reality and is possibly landing on our Thanksgiving dinner plate too.
Genetic engineering could increase nutritional value of the food, provide immunity against different microorganisms and resistance against pests or extreme weather conditions and enhance biomass production. A lot of plants were already modified and improved, but so far just few of them are approved for human use.
Thanksgiving dinner is prepared using the food native to the New World. In the near future, thanks to rapidly growing industry of genetically modified food, traditional Thanksgiving dinner could easily become genetically modified.
Here are traditional ingredients of Thanksgiving dinner and their genetic improvements:
Milk
2-3% of human babies are allergic to the cow’s milk. Genetic engineering improved milk formula by removing beta-lactoglobulin or BLG, protein that triggers allergic reaction. Cow needs to be genetically modified to produce BLG free milk. It is complicated procedure, but proved to be successful in the experiment conducted in the New Zealand. BLG gene in the cow’s egg was “silenced” (down-regulated) prior to fertilization. Not all attempts to down-regulate the gene were successful and just a small number of embryos survived long gestation period (290 days). Those that survived, grew-up in hypo-allergic milk producing cows. Besides being safe for use in people that are prone to milk allergy, BLG free milk is nutritionally valuable due to higher concentration of casein (another milk protein). Safety tests need to be performed before genetically modified milk become available for worldwide use.
Carrots
Carrots are rich in dietary fibers, minerals and vitamins. So far, they have been genetically modified to resist pests, fungi and to increase herbicide tolerance. With latest genetic improvements, carrots could become important source of another element essential for human health - calcium. Carrots are rich in calcium, but without proper calcium carriers it couldn’t be maximally absorbed. Increased level of proteins that act like carriers would increase calcium bioavailability. Experiments with mice showed that genetically altered carrots provide 50% more calcium than regular carrots. Test with human showed that genetically modified carrots offer 41% more calcium compared to unaltered plants. Calcium and vitamin D are necessary for the proper bone metabolism and adequate bone mineral density. Osteoporosis is famous and widespread disease resulting from lack of calcium in the bones; it is usually treated by various calcium containing pills. Genetically modified plants would simplify the procedure by providing calcium directly from the meal. Calcium “enriched” carrots are still not available.
Golden Rice
Rice is popular and often consumed plant (a staple food for more than 50% of the human population). It is estimated that rice provides 1/5 of the calories intake in the world. Besides high carbohydrate level, rice is rich in minerals and vitamin B group. Genetically modified rice became rich in another element - beta-carotene, a precursor of vitamin A. Endosperm (edible part of the rice) is site of beta-carotene production, thanks to newly incorporated psy (daffodil derived) and crtl (Erwinia uredovora derived) genes. Expression of both genes is under control of the endosperm specific promoter. Lycopene is the end product of genetically modified plant but enzymes located in the endosperm transform lycopene to beta-carotene that is responsible for the yellow color of the modified rice. Dose of vitamin A and its bioavailability is high. One cup of golden rice per day satisfies daily needs for vitamin A. A lot of organizations recognized the potential golden rice could have for the world regions that are struggling with vitamin A deficiency and supported financially whole project (Bill Gates and Hellen Keller International organization, for example). It’s estimated that golden rice could become available for worldwide use in 2013.
Tomatoes
Tomatoes can be consumed as a part of the salads, juices, in cooked meals…. With low caloric value and high level of different vitamins, minerals and pigments, regular intake of this plant is a guarantee for good health. Recently, scientists figured out the way to increase the value of tomatoes even more. Genetic engineering result in plant producing small peptide, 6F, that mimic the action of ApoA-1, responsible for lowering of the LDL (low density lipoprotein) or “bad” cholesterol level. Increased LDL level is responsible for atherosclerotic plaques and arterial inflammation, increasing the risk of cardiac attack and myocardial ischemia. Cardiovascular mortality is one of the leading causes of death in the modern society. Scientific community is focused on this issue, and modified tomatoes could be one of the promising solutions. Efficiency of the genetically altered tomatoes is tested on the mice. Animals were kept on the high fat diet until atherosclerotic plaques and arterial inflammation became detectable. Tomatoes producing 6F peptide helped reduce LDL level and level of arterial inflammation; 6F decreased both atherosclerotic plaques and level of lysophosphatidic acid (associated with plaque formation), and increased the level of paraoxonase enzyme responsible for good cholesterol level, with antioxidant activity that could prevent heart attack. Future experiments will show if modified plant could combat arterial disorders in humans.
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Genetic engineering could increase nutritional value of the food, provide immunity against different microorganisms and resistance against pests or extreme weather conditions and enhance biomass production. A lot of plants were already modified and improved, but so far just few of them are approved for human use.
Thanksgiving dinner is prepared using the food native to the New World. In the near future, thanks to rapidly growing industry of genetically modified food, traditional Thanksgiving dinner could easily become genetically modified.
Here are traditional ingredients of Thanksgiving dinner and their genetic improvements:
Milk
2-3% of human babies are allergic to the cow’s milk. Genetic engineering improved milk formula by removing beta-lactoglobulin or BLG, protein that triggers allergic reaction. Cow needs to be genetically modified to produce BLG free milk. It is complicated procedure, but proved to be successful in the experiment conducted in the New Zealand. BLG gene in the cow’s egg was “silenced” (down-regulated) prior to fertilization. Not all attempts to down-regulate the gene were successful and just a small number of embryos survived long gestation period (290 days). Those that survived, grew-up in hypo-allergic milk producing cows. Besides being safe for use in people that are prone to milk allergy, BLG free milk is nutritionally valuable due to higher concentration of casein (another milk protein). Safety tests need to be performed before genetically modified milk become available for worldwide use.
Carrots
Carrots are rich in dietary fibers, minerals and vitamins. So far, they have been genetically modified to resist pests, fungi and to increase herbicide tolerance. With latest genetic improvements, carrots could become important source of another element essential for human health - calcium. Carrots are rich in calcium, but without proper calcium carriers it couldn’t be maximally absorbed. Increased level of proteins that act like carriers would increase calcium bioavailability. Experiments with mice showed that genetically altered carrots provide 50% more calcium than regular carrots. Test with human showed that genetically modified carrots offer 41% more calcium compared to unaltered plants. Calcium and vitamin D are necessary for the proper bone metabolism and adequate bone mineral density. Osteoporosis is famous and widespread disease resulting from lack of calcium in the bones; it is usually treated by various calcium containing pills. Genetically modified plants would simplify the procedure by providing calcium directly from the meal. Calcium “enriched” carrots are still not available.
Golden Rice
Rice is popular and often consumed plant (a staple food for more than 50% of the human population). It is estimated that rice provides 1/5 of the calories intake in the world. Besides high carbohydrate level, rice is rich in minerals and vitamin B group. Genetically modified rice became rich in another element - beta-carotene, a precursor of vitamin A. Endosperm (edible part of the rice) is site of beta-carotene production, thanks to newly incorporated psy (daffodil derived) and crtl (Erwinia uredovora derived) genes. Expression of both genes is under control of the endosperm specific promoter. Lycopene is the end product of genetically modified plant but enzymes located in the endosperm transform lycopene to beta-carotene that is responsible for the yellow color of the modified rice. Dose of vitamin A and its bioavailability is high. One cup of golden rice per day satisfies daily needs for vitamin A. A lot of organizations recognized the potential golden rice could have for the world regions that are struggling with vitamin A deficiency and supported financially whole project (Bill Gates and Hellen Keller International organization, for example). It’s estimated that golden rice could become available for worldwide use in 2013.
Tomatoes
Tomatoes can be consumed as a part of the salads, juices, in cooked meals…. With low caloric value and high level of different vitamins, minerals and pigments, regular intake of this plant is a guarantee for good health. Recently, scientists figured out the way to increase the value of tomatoes even more. Genetic engineering result in plant producing small peptide, 6F, that mimic the action of ApoA-1, responsible for lowering of the LDL (low density lipoprotein) or “bad” cholesterol level. Increased LDL level is responsible for atherosclerotic plaques and arterial inflammation, increasing the risk of cardiac attack and myocardial ischemia. Cardiovascular mortality is one of the leading causes of death in the modern society. Scientific community is focused on this issue, and modified tomatoes could be one of the promising solutions. Efficiency of the genetically altered tomatoes is tested on the mice. Animals were kept on the high fat diet until atherosclerotic plaques and arterial inflammation became detectable. Tomatoes producing 6F peptide helped reduce LDL level and level of arterial inflammation; 6F decreased both atherosclerotic plaques and level of lysophosphatidic acid (associated with plaque formation), and increased the level of paraoxonase enzyme responsible for good cholesterol level, with antioxidant activity that could prevent heart attack. Future experiments will show if modified plant could combat arterial disorders in humans.
Related videos
by BojanaL at 11-22-2012, 05:13 PM
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Scientists at Princeton University have developed a synthetic enzyme that will modulate ingested drug to prevent its metabolic degradation and reduce both toxicity and dose needed for expected medical effect.
Long and healthy life of the average man is dependent on the productive pharmaceutical industry. Thousands of drugs are available all over the globe. Despite having healing effect, drugs are associated with more or less severe adverse effects. Ingested chemicals are undergoing metabolic transformation before they are eliminated from the body. Metabolites (end products of drug degradation) could be reactive and inflict damage to the nearby healthy tissue. Liver is essential organ for drug transformation; it could be imagined as waste factory of the human body, where different chemicals are degraded thanks to numerous enzymatically enhanced biochemical processes.
Drug (xenobiotic) metabolism facilitates drug elimination from the organism by converting lipophilic compounds into hydrophilic metabolites. This process decreases pharmaceutical potential of the drug. Higher concentration of the drug is always applied to ensure desired medical effect. Enzymes responsible for drug metabolism are known as CYP enzymes (located mainly in the liver); they provoke either detoxification, when toxic compound is metabolized into less toxic metabolite, or toxication, when non-toxic compound is transformed into harmful metabolite. Xenobiotic metabolism is divided in couple of phases. In the first phase mixed function oxydases will eliminate hydrogen or add oxygen to create more polar compound that could be easily excreted from the body. Some drugs will be eliminated after this phase. Some other demand further transformation: endogenous substrate will bond to the newly added functional groups and increase polarity of the created conjugate. In the second phase, interaction of the polar functional groups of the phase I metabolites result in detoxified product. Conjugation reactions including methylation, acetylation, sulphation, glucuronidation on the carboxyl, hydroxyl, amino and sulfhydryl groups are turning reactive phase I conjugates into less active metabolites that could be excreted easily.
Scientists from the Chemical department of Princeton University and Caltech group of California Institute of Technology's Materials and Process Simulation Center teamed up to develop synthetic enzyme that will modulate ingested drug to prevent its metabolic degradation and reduce both toxicity and dose needed for expected medical effect. Created enzyme is acting like a catalyst that is replacing certain hydrogen with fluoride atoms. Altered drug molecule is stable and “safe” from the liver enzymes with the same (or even increased) pharmaceutical potential. Without metabolic degradation, level of available drug in the body is high and dose could be easily reduced. Addition of fluorine results in increased lipophilicity of a drug (essential for all in vivo acting molecules). It also increases fat solubility resulting in elevated drug bioavailability. Fluoride enhances binding of the drug to the enzymatic or receptor sites. Carbon and fluorine create strong bond with a higher oxidative and thermal stability compared to carbon – hydrogen bond. Some other functional groups could also make reversible electrostatic bonds with fluoride. This kind of substitution is useful when developing drugs where stable covalent bonds with molecular targets are needed.
Synthetic enzyme that is responsible for hydrogen – fluoride substitution is similar to cytochrome P450 that replaces hydrogen for oxygen atoms. However, unlike iron based cytochrome P450 enzyme, newly developed enzyme is manganese based. This enzyme is developed two years ago with a goal to increase drug reactivity by replacing hydrogen atoms with chlorine atoms. Scientists assumed that manganese based cytochrome P450 could also work properly if fluoride atoms are offered. They experimented with couple of fluoride materials and discovered that combination of silver fluoride and tetrabutylammonium fluoride trihydrate is the easiest and the safest way to incorporate fluoride into drug molecule. Computational methods are further used to test drug safety and pharmaceutical activity. Besides being effective in decreasing toxicity and dose applied, this method could be used in designing radioactive tracer drugs as easiest and less expensive method in medical imaging (to determine mechanism of action and exact reactive site of the drug in the organism). Already marketed drugs are currently under investigation for the potential improvement using fluorination method. Scientists are especially focused on steroid drugs because this class of drugs is widely used. All kind of hormone replacement therapy and/or birth control pills and various anti-inflammatory drugs are typical representatives of steroid drugs.
Further experiments will show if fluorination could alleviate unwanted side effects and provide safe and efficient drug treatment.
Long and healthy life of the average man is dependent on the productive pharmaceutical industry. Thousands of drugs are available all over the globe. Despite having healing effect, drugs are associated with more or less severe adverse effects. Ingested chemicals are undergoing metabolic transformation before they are eliminated from the body. Metabolites (end products of drug degradation) could be reactive and inflict damage to the nearby healthy tissue. Liver is essential organ for drug transformation; it could be imagined as waste factory of the human body, where different chemicals are degraded thanks to numerous enzymatically enhanced biochemical processes.
Drug (xenobiotic) metabolism facilitates drug elimination from the organism by converting lipophilic compounds into hydrophilic metabolites. This process decreases pharmaceutical potential of the drug. Higher concentration of the drug is always applied to ensure desired medical effect. Enzymes responsible for drug metabolism are known as CYP enzymes (located mainly in the liver); they provoke either detoxification, when toxic compound is metabolized into less toxic metabolite, or toxication, when non-toxic compound is transformed into harmful metabolite. Xenobiotic metabolism is divided in couple of phases. In the first phase mixed function oxydases will eliminate hydrogen or add oxygen to create more polar compound that could be easily excreted from the body. Some drugs will be eliminated after this phase. Some other demand further transformation: endogenous substrate will bond to the newly added functional groups and increase polarity of the created conjugate. In the second phase, interaction of the polar functional groups of the phase I metabolites result in detoxified product. Conjugation reactions including methylation, acetylation, sulphation, glucuronidation on the carboxyl, hydroxyl, amino and sulfhydryl groups are turning reactive phase I conjugates into less active metabolites that could be excreted easily.
Scientists from the Chemical department of Princeton University and Caltech group of California Institute of Technology's Materials and Process Simulation Center teamed up to develop synthetic enzyme that will modulate ingested drug to prevent its metabolic degradation and reduce both toxicity and dose needed for expected medical effect. Created enzyme is acting like a catalyst that is replacing certain hydrogen with fluoride atoms. Altered drug molecule is stable and “safe” from the liver enzymes with the same (or even increased) pharmaceutical potential. Without metabolic degradation, level of available drug in the body is high and dose could be easily reduced. Addition of fluorine results in increased lipophilicity of a drug (essential for all in vivo acting molecules). It also increases fat solubility resulting in elevated drug bioavailability. Fluoride enhances binding of the drug to the enzymatic or receptor sites. Carbon and fluorine create strong bond with a higher oxidative and thermal stability compared to carbon – hydrogen bond. Some other functional groups could also make reversible electrostatic bonds with fluoride. This kind of substitution is useful when developing drugs where stable covalent bonds with molecular targets are needed.
Synthetic enzyme that is responsible for hydrogen – fluoride substitution is similar to cytochrome P450 that replaces hydrogen for oxygen atoms. However, unlike iron based cytochrome P450 enzyme, newly developed enzyme is manganese based. This enzyme is developed two years ago with a goal to increase drug reactivity by replacing hydrogen atoms with chlorine atoms. Scientists assumed that manganese based cytochrome P450 could also work properly if fluoride atoms are offered. They experimented with couple of fluoride materials and discovered that combination of silver fluoride and tetrabutylammonium fluoride trihydrate is the easiest and the safest way to incorporate fluoride into drug molecule. Computational methods are further used to test drug safety and pharmaceutical activity. Besides being effective in decreasing toxicity and dose applied, this method could be used in designing radioactive tracer drugs as easiest and less expensive method in medical imaging (to determine mechanism of action and exact reactive site of the drug in the organism). Already marketed drugs are currently under investigation for the potential improvement using fluorination method. Scientists are especially focused on steroid drugs because this class of drugs is widely used. All kind of hormone replacement therapy and/or birth control pills and various anti-inflammatory drugs are typical representatives of steroid drugs.
Further experiments will show if fluorination could alleviate unwanted side effects and provide safe and efficient drug treatment.
by priyasaravanan_1406 at 11-21-2012, 08:27 PM
5 comments
Toxicant is the name given to the substances that are potential to cause any undesirable effect in the living organism even causing death of the organism on exposure to such compounds. In simpler term a toxicant is called as poison. With wide variety of toxicants present in the environment one cannot escape from being exposed to it either intentionally or unintentionally. How does these toxic substances gain entry into our body on exposure and what happens to it in our system and how it is eliminated from the body is a quite interesting phenomenon very well defined under the area of science called as ‘Toxicology’.
The mode of exposure to the toxic substance determines the route of entry of the substance into the body. The mode of exposure is either by a physical contact like handling the substance or through inhaling the toxicant or through intake of the toxic substance. In case of physical contact with the substance the route of entry is skin and in case of inhalation the route of entry is lungs and gastrointestinal tract in the scenario of direct intake. Inspite of these multiple routes of entry the toxicant ultimately enters the blood stream. Besides all these routes the toxicant gains direct entry into the blood stream by injecting the substance either intravenously, intraperitoneal, subcutaneously or intramuscularly.
The skin which acts as the barrier between the body and the environment is a quite challenging route for the toxicants to enter the body. The epidermal layer of cells, the hair follicles, oil gland and sweat gland present on the skin are the possible route of entry for a toxicant to reach the blood stream. The entry through epidermal layer is difficult for the toxicants as it has to cross underlying layers such as the germinal layer and corium to reach the blood stream. The rate of diffusion of the toxicant is directly proportional to the permeable nature of the skin. Except for few toxics like acids and alkali makes the skin highly permeable by damaging the skin layer. The permeability of the skin is different for different species.
The toxic agents present in the air enter the body through respiratory tract upon inhalation. The toxic gases like carbon monoxide, sulphur dioxide and nitrogen dioxide and the volatile substances like benzene, the suspended particulate matter in the air enters the lungs through respiration. The absorption of these toxics in lungs is influenced by the larger area of the lungs and increased blood flow to the lungs. The quantity of the toxic gas in the air and the partial pressure of the same are the two factors governing the entry of the toxic gases through inhalation. The solubility nature of the toxic element decides the rate of diffusion of the substance from the lungs to the blood stream.
The next route of entry to be discussed is the gastrointestinal tract where the toxins make its entry via food chain. Also direct intake of toxic substance intentionally reaches the gastrointestinal tract. Thus the toxins reaching the GI tract is mostly harmless till the process of absorption of the toxin by the GI tract takes place. As the GI tract has several transport channels for the various nutrients, minerals and aminoacid present in the food, some of the toxins uses these transport system to reach the blood stream. The micro flora, acid and enzymes present in the GI tract are considered as important factors determining the fate of the toxin entering the GI tract. There is a possibility that the action of any of these factors on the toxic substance can reduce the toxicity of the substance. The rate of toxic element entering the blood stream from the GI tract depends upon the dissolution nature of the element.
Once entering the blood stream through different routes the toxicants either reaches their target organs or gets collected at various sites. The various such collection or storage units are the plasma proteins (albumin, globulin, and transferrin), the fat deposit of the body, the bone, the liver and the kidney. The toxicity of the element is organ specific and hence it need not be exhibited at the storage points.
Finally the distributed compounds are eliminated from the body by the proper functioning of the two vital organs, the liver and the kidney. The liver metabolizes the toxic element and releases into the bile for excretion and the kidney filters the blood and eliminates the toxins.
The amount of toxic substance, the length of exposure to the toxic substance, the age and health of the exposed individual are factors to be observed and analyzed to understand the effects of the toxin on the individual.
The mode of exposure to the toxic substance determines the route of entry of the substance into the body. The mode of exposure is either by a physical contact like handling the substance or through inhaling the toxicant or through intake of the toxic substance. In case of physical contact with the substance the route of entry is skin and in case of inhalation the route of entry is lungs and gastrointestinal tract in the scenario of direct intake. Inspite of these multiple routes of entry the toxicant ultimately enters the blood stream. Besides all these routes the toxicant gains direct entry into the blood stream by injecting the substance either intravenously, intraperitoneal, subcutaneously or intramuscularly.
The skin which acts as the barrier between the body and the environment is a quite challenging route for the toxicants to enter the body. The epidermal layer of cells, the hair follicles, oil gland and sweat gland present on the skin are the possible route of entry for a toxicant to reach the blood stream. The entry through epidermal layer is difficult for the toxicants as it has to cross underlying layers such as the germinal layer and corium to reach the blood stream. The rate of diffusion of the toxicant is directly proportional to the permeable nature of the skin. Except for few toxics like acids and alkali makes the skin highly permeable by damaging the skin layer. The permeability of the skin is different for different species.
The toxic agents present in the air enter the body through respiratory tract upon inhalation. The toxic gases like carbon monoxide, sulphur dioxide and nitrogen dioxide and the volatile substances like benzene, the suspended particulate matter in the air enters the lungs through respiration. The absorption of these toxics in lungs is influenced by the larger area of the lungs and increased blood flow to the lungs. The quantity of the toxic gas in the air and the partial pressure of the same are the two factors governing the entry of the toxic gases through inhalation. The solubility nature of the toxic element decides the rate of diffusion of the substance from the lungs to the blood stream.
The next route of entry to be discussed is the gastrointestinal tract where the toxins make its entry via food chain. Also direct intake of toxic substance intentionally reaches the gastrointestinal tract. Thus the toxins reaching the GI tract is mostly harmless till the process of absorption of the toxin by the GI tract takes place. As the GI tract has several transport channels for the various nutrients, minerals and aminoacid present in the food, some of the toxins uses these transport system to reach the blood stream. The micro flora, acid and enzymes present in the GI tract are considered as important factors determining the fate of the toxin entering the GI tract. There is a possibility that the action of any of these factors on the toxic substance can reduce the toxicity of the substance. The rate of toxic element entering the blood stream from the GI tract depends upon the dissolution nature of the element.
Once entering the blood stream through different routes the toxicants either reaches their target organs or gets collected at various sites. The various such collection or storage units are the plasma proteins (albumin, globulin, and transferrin), the fat deposit of the body, the bone, the liver and the kidney. The toxicity of the element is organ specific and hence it need not be exhibited at the storage points.
Finally the distributed compounds are eliminated from the body by the proper functioning of the two vital organs, the liver and the kidney. The liver metabolizes the toxic element and releases into the bile for excretion and the kidney filters the blood and eliminates the toxins.
The amount of toxic substance, the length of exposure to the toxic substance, the age and health of the exposed individual are factors to be observed and analyzed to understand the effects of the toxin on the individual.
by Kamat2010 at 11-21-2012, 06:41 PM
0 comments
Cytokines belong to a class of regulatory proteins that are produced in very minute amounts upon stimulation and are generally pleiotropic in nature i.e. have multiple actions on different target cells or organs. They are potent molecules and some distinct cytokines have functions that are redundant and overlapping. The cytokines may be autocrine or paracrine having important role in the cross talk between the cells within the body. The advance in RDT has helped in grouping the cytokines and their receptors based on their structure by the cloning of their genes. The cytokine molecules, their receptors and their signal transduction pathways have become promising targets for the study of therapeutic interference due to the multifunctional nature of the cytokines.
The role of cytokines in the immune and inflammatory disorders has led to the advancement of the cytokine-based therapies. Manipulating the functions of the cytokines with the aim of either blocking or restoring the activity of the specific cytokines is one of the approaches in the cytokine therapies. The coupling of the cytokines with the toxins, cloning of the cytokines, formation and fusion of recombinant cytokines and its receptors with the Fc portion of the human IgG1and albumin for stabilizing and thus increasing the serum half-life of the proteins, are being studied. The cloning of the natural and synthetic antagonists that interfere in the ligand-receptor interaction is being studied. The use of gene therapy and antisense oligonucleotides in delivering cytokines is also being assessed. The currently used approach for cytokine therapy is the use of monoclonal antibodies (mAbs) for blocking or neutralizing the action of cytokines. The use of completely human anticytokine mAbs for clinical purpose has been approved.
A novel approach in the treatment of inflammatory autoimmune diseases is the targeting of inflammatory cytokines. The drugs that block their action e.g. TNF (Tumor Necrosis Factor) are being used successfully in therapeutics of rheumatoid arthritis (RA). Apart from it, the fusion proteins of the sTNF receptor and Interleukin (IL) 1R antagonist are also major components in the RA therapeutics. The therapy involving the TNF α and IL-1 antagonists are now having wider scope and their use is being extended to other autoimmune inflammatory diseases. The use of TNF blockers are much more efficient than the therapy aimed at only the antagonism of the IL-1. The successful studies on IL-1 have led to the development of mAbs that target some of the cytokines and their receptors such as IL-6, IL-8, IL-18 and Interferon γ in different clinical conditions. The cytokine therapy using recombinant cytokines has been successful in different cases such as
a) IL-2 in cancer
b) IFN-α and its derivatives in various types of viral infections and cancer
c) IFN-β in multiple sclerosis
d) IFN-γ in cancer and osteoporosis
e) IL-11 in post chemotherapy induced thrombocytopenia
In some cases, recombinant cytokines have produced no effect as seen in case of recombinant IL-10 that is immunosuppressive, however further research is required to analyse any possible therapeutic application in future. In rare cases, adverse side effects have been produced as seen in IL-12.
Autovaccination has been developed as a novel strategy for the therapy of various chronic diseases that result due to excess production of certain factors. The physical association of the foreign proteins with the self-antigens has been used for overcoming the tolerance against self-antigens. Successful studies have been performed in mice using immunologic complexes by chemical coupling of cytokines IL-9 and IL-12 that lead to the complete inhibition of the function of cytokines. Resistance for cutaneous leishmaniasis was seen in IL-9 vaccinated mice and for the experimental autoimmune encephalomyelitis (EAE) in the IL-12 vaccinated mice.
Application of cytokine therapy in different allergic diseases and asthma has shown great promise. Th2-dependent mechanisms mediate most of the allergic reactions in the body with the involvement of almost all the Th2 cytokines such as IL-4, IL-5, IL-9, and IL-13 making them potential targets for the cytokine therapy against allergic diseases. The main promoter of Th2 development is IL-4 in in-vivo and in-vitro as seen in murine models using OVA as the allergen. The role of IL-5 in allergic asthma is also being studied, though much success has not been achieved. Three anti-asthmatic drug leads in clinical phase I trials that are related to IL-13 demonstrate IL-13 to be a potential target for allergic asthma. Further studies are being conducted in mice to define the roles of IL-4 and IL-13 in different infectious and allergic diseases by using knockout models.
The pleiotropic nature of the cytokines remains to be a drawback in the application of cytokine therapy for complex diseases. Hence, if experiments could be designed for the simultaneous inactivation or activation of multiple cytokines, then complex disorders could be treated with this therapy. RNA interference could help in achieving this goal in future due to the advancement in RNAi delivery studies.
The role of cytokines in the immune and inflammatory disorders has led to the advancement of the cytokine-based therapies. Manipulating the functions of the cytokines with the aim of either blocking or restoring the activity of the specific cytokines is one of the approaches in the cytokine therapies. The coupling of the cytokines with the toxins, cloning of the cytokines, formation and fusion of recombinant cytokines and its receptors with the Fc portion of the human IgG1and albumin for stabilizing and thus increasing the serum half-life of the proteins, are being studied. The cloning of the natural and synthetic antagonists that interfere in the ligand-receptor interaction is being studied. The use of gene therapy and antisense oligonucleotides in delivering cytokines is also being assessed. The currently used approach for cytokine therapy is the use of monoclonal antibodies (mAbs) for blocking or neutralizing the action of cytokines. The use of completely human anticytokine mAbs for clinical purpose has been approved.
A novel approach in the treatment of inflammatory autoimmune diseases is the targeting of inflammatory cytokines. The drugs that block their action e.g. TNF (Tumor Necrosis Factor) are being used successfully in therapeutics of rheumatoid arthritis (RA). Apart from it, the fusion proteins of the sTNF receptor and Interleukin (IL) 1R antagonist are also major components in the RA therapeutics. The therapy involving the TNF α and IL-1 antagonists are now having wider scope and their use is being extended to other autoimmune inflammatory diseases. The use of TNF blockers are much more efficient than the therapy aimed at only the antagonism of the IL-1. The successful studies on IL-1 have led to the development of mAbs that target some of the cytokines and their receptors such as IL-6, IL-8, IL-18 and Interferon γ in different clinical conditions. The cytokine therapy using recombinant cytokines has been successful in different cases such as
a) IL-2 in cancer
b) IFN-α and its derivatives in various types of viral infections and cancer
c) IFN-β in multiple sclerosis
d) IFN-γ in cancer and osteoporosis
e) IL-11 in post chemotherapy induced thrombocytopenia
In some cases, recombinant cytokines have produced no effect as seen in case of recombinant IL-10 that is immunosuppressive, however further research is required to analyse any possible therapeutic application in future. In rare cases, adverse side effects have been produced as seen in IL-12.
Autovaccination has been developed as a novel strategy for the therapy of various chronic diseases that result due to excess production of certain factors. The physical association of the foreign proteins with the self-antigens has been used for overcoming the tolerance against self-antigens. Successful studies have been performed in mice using immunologic complexes by chemical coupling of cytokines IL-9 and IL-12 that lead to the complete inhibition of the function of cytokines. Resistance for cutaneous leishmaniasis was seen in IL-9 vaccinated mice and for the experimental autoimmune encephalomyelitis (EAE) in the IL-12 vaccinated mice.
Application of cytokine therapy in different allergic diseases and asthma has shown great promise. Th2-dependent mechanisms mediate most of the allergic reactions in the body with the involvement of almost all the Th2 cytokines such as IL-4, IL-5, IL-9, and IL-13 making them potential targets for the cytokine therapy against allergic diseases. The main promoter of Th2 development is IL-4 in in-vivo and in-vitro as seen in murine models using OVA as the allergen. The role of IL-5 in allergic asthma is also being studied, though much success has not been achieved. Three anti-asthmatic drug leads in clinical phase I trials that are related to IL-13 demonstrate IL-13 to be a potential target for allergic asthma. Further studies are being conducted in mice to define the roles of IL-4 and IL-13 in different infectious and allergic diseases by using knockout models.
The pleiotropic nature of the cytokines remains to be a drawback in the application of cytokine therapy for complex diseases. Hence, if experiments could be designed for the simultaneous inactivation or activation of multiple cytokines, then complex disorders could be treated with this therapy. RNA interference could help in achieving this goal in future due to the advancement in RNAi delivery studies.
by Kamat2010 at 11-21-2012, 01:51 PM
0 comments
The advance in the field of recombinant DNA technology and the techniques of plant transformation have helped in the creation of novel platforms for the production of proteins on the whole plants growing in soil or plant suspension cells that are grown in a bioreactor with fully defined synthetic media. Studies related to the use of plants as heterologous expression systems for the expression of recombinant proteins, both native as well as modified therapeutic ones from humans has gained importance in the past two decades with successful experiments related to the plant-based production of pharmaceutical proteins.
The scientists Barta et al. have established the ability of plants to express human genes. They have illustrated the expression of transcripts of human growth hormone fusion gene in the callus tissue of sunflower and undifferentiated tobacco, although there was no detection of any protein formation. Two potential therapeutic proteins have been successfully expressed in plant expression systems: human serum albumin that was expressed successfully in the potato and tobacco leaves and suspension cells and monoclonal antibody expressed in the leaves of tobacco. This process of using the plant-based systems for use as platforms for the effective production of molecules with industrial and pharmacological significance, is termed as ‘molecular farming’ (MF) with the pharmaceutically significant products obtained from them being termed as plant-derived pharmaceuticals (PDPs). A number of PDPs are being developed and commercialized that include antigens, blood substitutes, different enzymes, cytokines, antibodies and their fragments and many other important proteins.
The plant expression systems offer a number of advantages over other expression system platforms for the production of recombinant proteins such as being inexpensive, scaled highly as well as unsupportive of the growth of human pathogens. Due to the advantages offered, replacing the mammalian cell lines with plants for the expression and production of recombinant proteins was considered, though it had some technical drawbacks. The high investment involved with fermentation infrastructure, low grade performance of plants when compared to mammalian cell lines and the lack of regulation systems in plants for the production of biopharmaceutical products resulted in the lack of industrial interest.
Latest research has helped in overcoming the technical hurdles in the utility of plant expression systems.
a) Improvement of the intrinsic yields could be done by maximizing transcription by optimal expression construct designing, stability of mRNAs for translation, increasing the copy number of transgene and introduction of these transgenes within the germplasm. Reverse transition cycling is one of the methods employed for increasing yield and for convenient extraction. This process has been employed in some oil crops as well as seed storage proteins.
b) The downstream processing (DSP) of the yielded protein is very essential that requires the isolation of the expressed protein and involves the removal of fibers, by-products of metabolism as well as oil, based on the crops involved as in case of nicotine from tobacco leaves, etc.
c) One of the regulatory aspects of MF is the presence of plant glycans that may be necessary for the biological activity, stability, targeting, PK (Pharmacokinetic) as well as immunogenic properties of the therapeutic proteins that are glycoprotein. in nature.
However, the differences between plant and human glycans and the effect of the plant glycans on the protein structure, activity, etc have resulted in initiating research to abolish the plant-specific glycosylases by gene knockout and RNA interference as seen in tobacco, Arabidopsis, etc.
The absence of commercial pedigree of proteins was one of the hurdles faced by MF solved by the production of non-medical proteins by the plants for the commercial use. E.g. Maize was used as a platform for the production of avidin and β-glucoronidase (GUS) enzymes that have potential use in molecular biology. Both the proteins were similar to the natural ones in every aspect of activity, structure, etc. Although, there has not been much progress in the commercial production of such type of proteins for therapeutic use, it opens up new prospect for future research studies.
The regulatory perspective of the PDPs that involves the replacement of cell banks with seed banks, accounting natural variation in the plant organs by verifying batch to batch consistency, operating and processing techniques for various expression and production systems are some of the guidelines of FDA for the commercialization of plant-derived proteins.
The good manufacturing practice (GMP) strategy of the PDPs from whole plants is essential for the development of plant expression systems that includes
1) the selection of appropriate plants or crops as expression systems,
2) selection of proper cultivation method,
3) Knowledge of relative merits about the stable as well as transient expression systems and the DSP in plant systems compared to the other cell lines like mammalian, yeast, or bacterial.
The use of PDPs in near future can be foreseen in the development of various pharmaceutical products, vaccines, etc by solving the issues and adopting different strategies of GMP.
The scientists Barta et al. have established the ability of plants to express human genes. They have illustrated the expression of transcripts of human growth hormone fusion gene in the callus tissue of sunflower and undifferentiated tobacco, although there was no detection of any protein formation. Two potential therapeutic proteins have been successfully expressed in plant expression systems: human serum albumin that was expressed successfully in the potato and tobacco leaves and suspension cells and monoclonal antibody expressed in the leaves of tobacco. This process of using the plant-based systems for use as platforms for the effective production of molecules with industrial and pharmacological significance, is termed as ‘molecular farming’ (MF) with the pharmaceutically significant products obtained from them being termed as plant-derived pharmaceuticals (PDPs). A number of PDPs are being developed and commercialized that include antigens, blood substitutes, different enzymes, cytokines, antibodies and their fragments and many other important proteins.
The plant expression systems offer a number of advantages over other expression system platforms for the production of recombinant proteins such as being inexpensive, scaled highly as well as unsupportive of the growth of human pathogens. Due to the advantages offered, replacing the mammalian cell lines with plants for the expression and production of recombinant proteins was considered, though it had some technical drawbacks. The high investment involved with fermentation infrastructure, low grade performance of plants when compared to mammalian cell lines and the lack of regulation systems in plants for the production of biopharmaceutical products resulted in the lack of industrial interest.
Latest research has helped in overcoming the technical hurdles in the utility of plant expression systems.
a) Improvement of the intrinsic yields could be done by maximizing transcription by optimal expression construct designing, stability of mRNAs for translation, increasing the copy number of transgene and introduction of these transgenes within the germplasm. Reverse transition cycling is one of the methods employed for increasing yield and for convenient extraction. This process has been employed in some oil crops as well as seed storage proteins.
b) The downstream processing (DSP) of the yielded protein is very essential that requires the isolation of the expressed protein and involves the removal of fibers, by-products of metabolism as well as oil, based on the crops involved as in case of nicotine from tobacco leaves, etc.
c) One of the regulatory aspects of MF is the presence of plant glycans that may be necessary for the biological activity, stability, targeting, PK (Pharmacokinetic) as well as immunogenic properties of the therapeutic proteins that are glycoprotein. in nature.
However, the differences between plant and human glycans and the effect of the plant glycans on the protein structure, activity, etc have resulted in initiating research to abolish the plant-specific glycosylases by gene knockout and RNA interference as seen in tobacco, Arabidopsis, etc.
The absence of commercial pedigree of proteins was one of the hurdles faced by MF solved by the production of non-medical proteins by the plants for the commercial use. E.g. Maize was used as a platform for the production of avidin and β-glucoronidase (GUS) enzymes that have potential use in molecular biology. Both the proteins were similar to the natural ones in every aspect of activity, structure, etc. Although, there has not been much progress in the commercial production of such type of proteins for therapeutic use, it opens up new prospect for future research studies.
The regulatory perspective of the PDPs that involves the replacement of cell banks with seed banks, accounting natural variation in the plant organs by verifying batch to batch consistency, operating and processing techniques for various expression and production systems are some of the guidelines of FDA for the commercialization of plant-derived proteins.
The good manufacturing practice (GMP) strategy of the PDPs from whole plants is essential for the development of plant expression systems that includes
1) the selection of appropriate plants or crops as expression systems,
2) selection of proper cultivation method,
3) Knowledge of relative merits about the stable as well as transient expression systems and the DSP in plant systems compared to the other cell lines like mammalian, yeast, or bacterial.
The use of PDPs in near future can be foreseen in the development of various pharmaceutical products, vaccines, etc by solving the issues and adopting different strategies of GMP.
by kanagasundar87 at 11-20-2012, 01:57 PM
3 comments
Hi all,
I am prepare in entrance exam. I need help.
A restriction endonuclease has the recognition sequence G/AATTC, where "/" indicate the cut side. This sequence is found, on average, once every 'X' residues in a chromosome. 'X' =
Options
a. 146 base - pairs
b. 200 base - pairs
c 256 base - pairs
d. 4096 base - pairs
advance thanks reply as soon as possible
I am prepare in entrance exam. I need help.
A restriction endonuclease has the recognition sequence G/AATTC, where "/" indicate the cut side. This sequence is found, on average, once every 'X' residues in a chromosome. 'X' =
Options
a. 146 base - pairs
b. 200 base - pairs
c 256 base - pairs
d. 4096 base - pairs
advance thanks reply as soon as possible
by Kamat2010 at 11-20-2012, 02:39 AM
3 comments
Hair loss is one of the common problems faced by a large number of men and women. There are a number of remedies that are available in the market namely wigs, topical treatments, drugs, nutrient supplements like vitamin, hair transplant surgery, caps and hats or complete shaving of hair. Other than these treatments, there are a number of associations, support groups, counsellors, etc to help people cope with the mental agony caused due to hair loss. Since, no permanent cure has yet been devised for the baldness, constant research studies are being carried out to find out the reasons responsible for the development of baldness.
Research has shown that the development of hair follicles takes place in the womb and after birth; there is no appearance of new follicles. In the head of a person, there are about 100,000 follicles and if the follicles are severely damaged due to any reason, it results in its end of the follicles and there is no further formation of hair from those follicles. The follicles are limited in their ability for regeneration and as there is no new formation of follicles after birth, it causes severe hair loss resulting in baldness.
The scientists in the University of Pennsylvania have illustrated the role of a particular gene that is responsible for the hair follicle formation. They have performed successful studies in mice for the regeneration of hair follicles. They have found the role of a particular gene called Wnt, which on manipulation leads to hair follicle regeneration. This study provides an area of vast application for devising methods regarding hair re-growth.
The studies showed the role of Wnt gene in the process of wound healing and the formation of new hair follicles. Different experiments were performed, which illustrated the formation of new follicles in the wound healing process; hence, this could be manipulated for increasing the number of follicles to a great extent. The experiment involved the removal of small sections of skin from the mice that resulted in the formation of new skin in those regions due to stem cell activity. During the process of the wound healing, it was observed that the skin that formed during the healing process possessed the characteristics of the normal skin with the original glands, hair follicles and eventually the same appearance. It was seen that if the Wnt gene was active, the normal healing process was achieved, while in the Wnt gene knockout mice or the mice, in which the Wnt gene was blocked, there was no formation of hair follicles. Moreover, it was also observed that increasing the activity of Wnt gene resulted in an increase in hair growth. Hence, it was concluded that the creation of wounds caused the ‘waking up’ of the Wnt gene, which activated the wound healing process, thereby resulting in formation of hair follicles resulting in new hair growth.
Hence, it can be seen that the studies have created a new view among the scientists to look at the aspect of gene therapy for baldness instead of looking at hormones. Although, the regeneration ability of many animals is known like the re-growth of tail, limbs, etc, the ability of regeneration in mammals was thought to be quite limited. However, the successful studies of regeneration of hair follicles and surrounding area of skin in mice after the creation of wounds have generated interest for further in-depth studies in this area and for successful translation to human studies. The new possibilities in the treatment of wounds have shown great promise for reconsidering the regenerative capabilities of skin in mammals.
The studies on the Wnt gene may stimulate detailed analysis on the subject for finding new solutions and treatments for baldness. However, it fails to generate the same amount of enthusiasm in others as previous researches on the discovery of ‘hairless’ gene responsible for baldness by scientists in Columbia University in 1998 could not be translated into hair loss therapies due to various reasons. Hence, the development of permanent solutions for baldness using gene therapy is a dream for future as extensive studies are essential related to the subject. The role of inherited genes and stem cells in the development of baldness continue to excite the scientists for further detailed research on the subject.
Research has shown that the development of hair follicles takes place in the womb and after birth; there is no appearance of new follicles. In the head of a person, there are about 100,000 follicles and if the follicles are severely damaged due to any reason, it results in its end of the follicles and there is no further formation of hair from those follicles. The follicles are limited in their ability for regeneration and as there is no new formation of follicles after birth, it causes severe hair loss resulting in baldness.
The scientists in the University of Pennsylvania have illustrated the role of a particular gene that is responsible for the hair follicle formation. They have performed successful studies in mice for the regeneration of hair follicles. They have found the role of a particular gene called Wnt, which on manipulation leads to hair follicle regeneration. This study provides an area of vast application for devising methods regarding hair re-growth.
The studies showed the role of Wnt gene in the process of wound healing and the formation of new hair follicles. Different experiments were performed, which illustrated the formation of new follicles in the wound healing process; hence, this could be manipulated for increasing the number of follicles to a great extent. The experiment involved the removal of small sections of skin from the mice that resulted in the formation of new skin in those regions due to stem cell activity. During the process of the wound healing, it was observed that the skin that formed during the healing process possessed the characteristics of the normal skin with the original glands, hair follicles and eventually the same appearance. It was seen that if the Wnt gene was active, the normal healing process was achieved, while in the Wnt gene knockout mice or the mice, in which the Wnt gene was blocked, there was no formation of hair follicles. Moreover, it was also observed that increasing the activity of Wnt gene resulted in an increase in hair growth. Hence, it was concluded that the creation of wounds caused the ‘waking up’ of the Wnt gene, which activated the wound healing process, thereby resulting in formation of hair follicles resulting in new hair growth.
Hence, it can be seen that the studies have created a new view among the scientists to look at the aspect of gene therapy for baldness instead of looking at hormones. Although, the regeneration ability of many animals is known like the re-growth of tail, limbs, etc, the ability of regeneration in mammals was thought to be quite limited. However, the successful studies of regeneration of hair follicles and surrounding area of skin in mice after the creation of wounds have generated interest for further in-depth studies in this area and for successful translation to human studies. The new possibilities in the treatment of wounds have shown great promise for reconsidering the regenerative capabilities of skin in mammals.
The studies on the Wnt gene may stimulate detailed analysis on the subject for finding new solutions and treatments for baldness. However, it fails to generate the same amount of enthusiasm in others as previous researches on the discovery of ‘hairless’ gene responsible for baldness by scientists in Columbia University in 1998 could not be translated into hair loss therapies due to various reasons. Hence, the development of permanent solutions for baldness using gene therapy is a dream for future as extensive studies are essential related to the subject. The role of inherited genes and stem cells in the development of baldness continue to excite the scientists for further detailed research on the subject.
by priyasaravanan_1406 at 11-19-2012, 11:42 PM
0 comments
What is immunity and types of immunity:
Human body is a store house of wonders and astonishing features and functions making it an interesting and curious subject to understand and deal with. Made up of millions of cells, the role of each cell, tissue and organ right from the date of manufacture (embryo) till expiry (death) is quite amazing. Our body takes care of itself very well and also knows how to protect itself from molecules foreign to the body. In this regard our body has a well developed defensive system always ready to fight with the pathogen entering the body called as the immune system and the resistance towards a pathogen is called as the immunity. Here let us discuss the two types of immunity, the innate immunity and the acquired immunity and the phenomenon of defense in both these types of immunity.
Innate Immunity: The inbuilt immunity of an individual based on his or her genetic makeup is called as the innate immunity in contrast to the prior exposure to antigen to develop immunity. The innate immunity is seen either at species level or racial level or individual level. Species innate immunity as the name implies is the immunity shown by all individuals of the same species to the pathogens of different species. Racial immunity is the term applied to the difference in resistance shown by races or groups belonging to the same species. The individual innate immunity is the difference in resistance among individuals belonging to the same race or group.
The mechanism of defense in innate immunity is categorized into three types based on the type of protective barriers involved. They are the anatomical barrier, the physiological barrier and the phagocytic or endocytic barrier. The anatomical barriers protecting the body from various pathogens is the skin and the mucous membrane lining the respiratory tract, digestive tract etc. Skin, the large blanket covering all the organs of the body spread from head to toe is the first layer of defense. The hair follicles on the skin, the oil and sweat glands present in skin all forms the components of defensive mechanism of the skin. The mucous membrane lining the nasal area plays an important role in trapping the pathogens trying to enter the body. The mucous membrane lining the respiratory tract has cilial structure which pushes the foreign body out of the system, thus protecting the individual. Also the mucous membrane of the GI tract has similar function in tackling the pathogen. The tear, saliva and mucous are the secretions engaged in antibacterial and antiviral activity.
Looking into the physiological barrier they are the pH, temperature and chemical mediators. Temperature acts as an immunity agent by showing direct effect on the pathogen. For example chicks with high body temperature show resistance to anthrax. Likewise pH also contributes to immunity. The acidic nature of the stomach restricts and eliminates the growth of various pathogens. One example of chemical mediators as barriers is well indicated by the bacterial cell wall cleaving property of the hydrolytic enzyme, the lysozyme. The phagocytic or endocytic mode of defense involves the role of cells in forming structures to engulf and digest the pathogen, bacteria for example.
Acquired Immunity: Acquired immunity is the specific resistance developed by the body only on exposure to antigen (the foreign body). The four salient features of an acquired immunity are Antigen specificity, diversity of the immune system in recognition of molecule, the immunologic memory which stores the information of the type of antigen attacked and the type of immunity developed to the same and retrieve the information on the second attack by the same antigen and finally the ability to recognize the self and non-self antigens.
Acquired immunity is classified into active and passive acquired immunity each again falls into two categories called as the natural and artificial immunity. Active acquired immunity is the immunity developed by the body in response to an antigen, which once developed seems to exist in the individual forever and also it is stored in the memory of the immune system and exhibited on attack by the same antigen for the second time. Natural active immunity is the immunity developed naturally in response to any infection whereas artificial active immunity is induced in an individual with the help of vaccines.
Passive immunity is the induction of immunity in the immune deficient individual by introducing antibodies or immune cells as such to them. Unlike active immunity, passive immunity exists only for a short term and no immunological memory takes place. The transfer of immune particles from mother to fetus via placenta or breast milk is an example of natural passive immunity whereas the introduction of processed serum rich in antibodies to an immune deficient host is artificial passive immunity.
Though the immune system of our body challenges most of the pathogens, the evolution of new viruses challenges the immune system which can be explained by an example of the action of HIV on the immune system.
Human body is a store house of wonders and astonishing features and functions making it an interesting and curious subject to understand and deal with. Made up of millions of cells, the role of each cell, tissue and organ right from the date of manufacture (embryo) till expiry (death) is quite amazing. Our body takes care of itself very well and also knows how to protect itself from molecules foreign to the body. In this regard our body has a well developed defensive system always ready to fight with the pathogen entering the body called as the immune system and the resistance towards a pathogen is called as the immunity. Here let us discuss the two types of immunity, the innate immunity and the acquired immunity and the phenomenon of defense in both these types of immunity.
Innate Immunity: The inbuilt immunity of an individual based on his or her genetic makeup is called as the innate immunity in contrast to the prior exposure to antigen to develop immunity. The innate immunity is seen either at species level or racial level or individual level. Species innate immunity as the name implies is the immunity shown by all individuals of the same species to the pathogens of different species. Racial immunity is the term applied to the difference in resistance shown by races or groups belonging to the same species. The individual innate immunity is the difference in resistance among individuals belonging to the same race or group.
The mechanism of defense in innate immunity is categorized into three types based on the type of protective barriers involved. They are the anatomical barrier, the physiological barrier and the phagocytic or endocytic barrier. The anatomical barriers protecting the body from various pathogens is the skin and the mucous membrane lining the respiratory tract, digestive tract etc. Skin, the large blanket covering all the organs of the body spread from head to toe is the first layer of defense. The hair follicles on the skin, the oil and sweat glands present in skin all forms the components of defensive mechanism of the skin. The mucous membrane lining the nasal area plays an important role in trapping the pathogens trying to enter the body. The mucous membrane lining the respiratory tract has cilial structure which pushes the foreign body out of the system, thus protecting the individual. Also the mucous membrane of the GI tract has similar function in tackling the pathogen. The tear, saliva and mucous are the secretions engaged in antibacterial and antiviral activity.
Looking into the physiological barrier they are the pH, temperature and chemical mediators. Temperature acts as an immunity agent by showing direct effect on the pathogen. For example chicks with high body temperature show resistance to anthrax. Likewise pH also contributes to immunity. The acidic nature of the stomach restricts and eliminates the growth of various pathogens. One example of chemical mediators as barriers is well indicated by the bacterial cell wall cleaving property of the hydrolytic enzyme, the lysozyme. The phagocytic or endocytic mode of defense involves the role of cells in forming structures to engulf and digest the pathogen, bacteria for example.
Acquired Immunity: Acquired immunity is the specific resistance developed by the body only on exposure to antigen (the foreign body). The four salient features of an acquired immunity are Antigen specificity, diversity of the immune system in recognition of molecule, the immunologic memory which stores the information of the type of antigen attacked and the type of immunity developed to the same and retrieve the information on the second attack by the same antigen and finally the ability to recognize the self and non-self antigens.
Acquired immunity is classified into active and passive acquired immunity each again falls into two categories called as the natural and artificial immunity. Active acquired immunity is the immunity developed by the body in response to an antigen, which once developed seems to exist in the individual forever and also it is stored in the memory of the immune system and exhibited on attack by the same antigen for the second time. Natural active immunity is the immunity developed naturally in response to any infection whereas artificial active immunity is induced in an individual with the help of vaccines.
Passive immunity is the induction of immunity in the immune deficient individual by introducing antibodies or immune cells as such to them. Unlike active immunity, passive immunity exists only for a short term and no immunological memory takes place. The transfer of immune particles from mother to fetus via placenta or breast milk is an example of natural passive immunity whereas the introduction of processed serum rich in antibodies to an immune deficient host is artificial passive immunity.
Though the immune system of our body challenges most of the pathogens, the evolution of new viruses challenges the immune system which can be explained by an example of the action of HIV on the immune system.
by Blackmoa at 11-19-2012, 10:29 PM
1 comments
Hey everyone,
Is it possible for sepal leaves to get chromosome number n, or are they always 2n?
Is it possible for sepal leaves to get chromosome number n, or are they always 2n?
by ashwathi at 11-19-2012, 10:28 PM
2 comments
Since time unknown, man has been involved in exploiting the nature around him for the benefit of his own. With the advent of biotechnology the tendency has increased and attained the thresh hold level. The level of interference by man is to a great extent arising thoughts of concern within the human population themselves. The genetically modified organisms and their products may disturb the equilibrium of ecosystem and can even pose as a threat to the stability of the planet even.
It was in the early 1970s that the discussions regarding ethical and non ethical issues concerning recombinant DNA technology was initiated. The concern is about non stability of such experiments conducted and their effects upon nature. A committee called as National Institute of Health, USA was formed which look into the issues which needs attention. The committee has put up certain guidelines for the experiments which have to be strictly adhered to by any experiment conducted in any of the nations. The objectives laid down mainly include practices which consist of conducting experiments on any living organism and the techniques applied for the same.
Risk assessment:
Risk assessment of the experiment involves determining the amount of uncertainty and the possible consequences involved in the same. The prime objectives included are determining the kind and level of experiments to be conducted on the living beings. The identification and evaluation of potential threats by the planned introduction of living organisms is done by risk assessment. This assessment is done by two steps:
(i) Initial assessment: These involve determining the risk involved based on the organism which is used for the experiments. Depending on the effect of organisms they are classified in to different Risk Groups (RG) -1, 2, 3, and 4.
RG 1- involves organisms which are not associated with any disease occurring in humans.
RG2- involves organisms which are involved in causing non lethal ailments in humans and for which treatment is easily and effectively available.
RG3- includes organisms which are linked with serious diseased condition in humans and the cure may be available.
RG4- consists of organisms which can cause highly dangerous health issues for which prevention and treatment is not developed.
(ii) Comprehensive assessment: This involves factors such as features of organism included like pathogenicity, virulence etc. and the type of manipulation involved.
Following risk assessment, the experiments are grouped under different categories which require clearance from different organisations like, Institutional Bio Safety Committee (IBC), Recombinant DNA Advisory Committee (RAC), Office of Biotechnology Activities, and many more. After risk assessment, the concerned group of persons involved will be directed to get approval from these committees. The risk assessment takes into consideration the following factors:
(i) The physical and biological nature of both donor and recipient organisms.
(ii) The properties of vector involved
(iii) The characteristics of DNA insert involved
(iv) Different techniques involved like detection, isolation, transfer and expression.
(v) Differences in the native and genetically modified organisms (GMO), the use of such organisms for several benefits and impact of such organisms in the environment and the impact of experiments on the organisms.
Potential threats involved in biotechnology:
The transgenic organism produced may affect other organisms negatively such as development of transgenic weeds or parasites. Often, the transfer is intended to be expressed by organisms lacking some property or by organisms which can provide products of economical importance. The chance of transfer of the transgene into a similar organism resulting in production of a hazardous organism or conditions may also arise wherein the transgene can also be overly expressed disturbing the well being of other organisms. Developments of insects or pathogens which are resistant to such transfers are also possible. The existence of the GMO s may affect the environment in which it thrives upsetting the equilibrium as they do not actually belong to the environment. Finally the product produced can also cause health hazards among organisms and especially humans.
Following the assessment of organisms involved in biotechnology, the products obtained from such organisms is also assessed to confirm that they do not pose any kind of threat to the humans when consumed. The assessment is based on the product that is modified, safety of the introduced transgene and the corresponding products formed .It essentially takes into consideration the genetics of organism involved, the technical procedures followed and composition of product formed.
It was in the early 1970s that the discussions regarding ethical and non ethical issues concerning recombinant DNA technology was initiated. The concern is about non stability of such experiments conducted and their effects upon nature. A committee called as National Institute of Health, USA was formed which look into the issues which needs attention. The committee has put up certain guidelines for the experiments which have to be strictly adhered to by any experiment conducted in any of the nations. The objectives laid down mainly include practices which consist of conducting experiments on any living organism and the techniques applied for the same.
Risk assessment:
Risk assessment of the experiment involves determining the amount of uncertainty and the possible consequences involved in the same. The prime objectives included are determining the kind and level of experiments to be conducted on the living beings. The identification and evaluation of potential threats by the planned introduction of living organisms is done by risk assessment. This assessment is done by two steps:
(i) Initial assessment: These involve determining the risk involved based on the organism which is used for the experiments. Depending on the effect of organisms they are classified in to different Risk Groups (RG) -1, 2, 3, and 4.
RG 1- involves organisms which are not associated with any disease occurring in humans.
RG2- involves organisms which are involved in causing non lethal ailments in humans and for which treatment is easily and effectively available.
RG3- includes organisms which are linked with serious diseased condition in humans and the cure may be available.
RG4- consists of organisms which can cause highly dangerous health issues for which prevention and treatment is not developed.
(ii) Comprehensive assessment: This involves factors such as features of organism included like pathogenicity, virulence etc. and the type of manipulation involved.
Following risk assessment, the experiments are grouped under different categories which require clearance from different organisations like, Institutional Bio Safety Committee (IBC), Recombinant DNA Advisory Committee (RAC), Office of Biotechnology Activities, and many more. After risk assessment, the concerned group of persons involved will be directed to get approval from these committees. The risk assessment takes into consideration the following factors:
(i) The physical and biological nature of both donor and recipient organisms.
(ii) The properties of vector involved
(iii) The characteristics of DNA insert involved
(iv) Different techniques involved like detection, isolation, transfer and expression.
(v) Differences in the native and genetically modified organisms (GMO), the use of such organisms for several benefits and impact of such organisms in the environment and the impact of experiments on the organisms.
Potential threats involved in biotechnology:
The transgenic organism produced may affect other organisms negatively such as development of transgenic weeds or parasites. Often, the transfer is intended to be expressed by organisms lacking some property or by organisms which can provide products of economical importance. The chance of transfer of the transgene into a similar organism resulting in production of a hazardous organism or conditions may also arise wherein the transgene can also be overly expressed disturbing the well being of other organisms. Developments of insects or pathogens which are resistant to such transfers are also possible. The existence of the GMO s may affect the environment in which it thrives upsetting the equilibrium as they do not actually belong to the environment. Finally the product produced can also cause health hazards among organisms and especially humans.
Following the assessment of organisms involved in biotechnology, the products obtained from such organisms is also assessed to confirm that they do not pose any kind of threat to the humans when consumed. The assessment is based on the product that is modified, safety of the introduced transgene and the corresponding products formed .It essentially takes into consideration the genetics of organism involved, the technical procedures followed and composition of product formed.
by ashwathi at 11-19-2012, 10:08 PM
1 comments
A wide variety of compounds obtained from organisms is used in treatment of diseases. These compounds may be obtained from recombinant and non recombinant organisms.
A large number of products from non recombinant organisms serve as pharmaceuticals. In certain cases, the micro organisms as such serve as cure for certain diseases like, for eg: the lactobacillus species. Various products like antibiotics, vitamins, enzymes, organics acids etc., play an inevitable role in disease treatment. Pharmaceutically important biochemical is also produced from plant cell cultures. Cultured animal cells too play their role in prevention and treatment of diseases.
The major drawback in using products from non recombinant organisms is the lower availability the products and the comparatively limited ability of products to cure diseases. They have to be used in its natural form and hence the spectrum of diseases covered is not wide spread. The advent of genetic engineering has enabled large scale production of existing and new products in disease treatment. The products from genetic engineering include:
Genetically engineered micro organisms:
Human gene has been known to encode a large number of pharmaceutically important proteins. These are cloned and expressed in micro organisms for increased production. Microbes are used as hosts in cloning purposes. E. coli, yeast are some of the most common examples of microbes which are used as hosts. In yeast many recombinant proteins having pharmaceutical significance has been produced. Eg: recombinant insulin used in the treatment of diabetes, human growth hormone for dwarfism, interferon, interleukin, granulocyte macrophage colony stimulating factor, etc.
The most extensive protein developed in such a manner is human insulin. It consists of two chains known as A and B which are interlinked by two disulphide bridges. The gene coding was integrated separately to a host cell, expressed and modified to produce functional insulin.
Animal cell cultures are also used for expression of human genes encoding pharmaceutically valuable proteins. The main proteins produced by this way are erythropoietin and blood clotting factor VIII. Plant cells producing recombinant proteins are high in demand as many ethical issues related to animal cell culture do not exist with the transgenic plants. In the case of transgenic plants, the process of retrieval of recombinant proteins from the parts of plant cells is comparatively easy. The most relevant example of transgenic plants aiding in the disease treatment is production of a polypeptide called hirudin. This is produced by a synthetic gene expressed in the plant Brassica napus. This is produced as a fusion protein with oleisn which is an oil body protein. Upon successful integration and extraction, the hirudin is extracted with water and later centrifuged to separate our protein from the rest of the proteins produced with the help of oil body. The pure hirudin is separated from olesin by subjecting the obtained oil moisture to proteolytic cleavage.
Antisense nucleotides:
A novel approach of disease treatment is the production of antisense oligonucleotide. It involves production and use of oligonucleotides complementary to the 5’ end of the parasite mRNAs. This antisense oligonucleotide is often linked with acridine for increasing the effectiveness of the same. The application of such oligonucleotides is in the case of cancer.
Monoclonal antibodies:
These have been known to exhibit several therapeutic applications like providing passive immunity, treatment of certain diseases like leprosy, deliver of immunotoxins specifically to cancer cells etc.
Drug designing:
This involves designing special drugs for special requirements of disease or the patient. These are designed to specifically bind to the critical site of target molecules thus inactivating the latter. These are so designed so that they do not exhibit any side effects rather than conventional drugs. Important examples are propanolol used in treatment of hypertension or heart attacks. Another example is cimetidine which blocks the hydrogen receptor in the stomach so that it effects the formation of ulcers in the stomach curing it. This has served as an important mechanism in treatment of cancer, gout, malaria, etc. Thos has resulted in developing a drug called azidothymidine (AZT) for treatment against HIV.
Drug delivery and targeting:
An effective improvement in the disease treatment is the introduction of technique of drug targeting. Often it is seen that conventional medicines loose their activity or sometimes part of their activity as they follow general distribution pattern. In drug targeting, the drugs are so targeted so that it affects only the required tissues and does not act upon anything else. This greatly enhances the drug effects and limits the amount of dosage required. Immunotoxins are the main example of such site directed delivery of drugs.
Gene therapy is yet another novel approach in the field of disease treatment with many successful examples in treating disease like cancer. Studies are being conducted on improving and developing the procedure for large scale use.
A large number of products from non recombinant organisms serve as pharmaceuticals. In certain cases, the micro organisms as such serve as cure for certain diseases like, for eg: the lactobacillus species. Various products like antibiotics, vitamins, enzymes, organics acids etc., play an inevitable role in disease treatment. Pharmaceutically important biochemical is also produced from plant cell cultures. Cultured animal cells too play their role in prevention and treatment of diseases.
The major drawback in using products from non recombinant organisms is the lower availability the products and the comparatively limited ability of products to cure diseases. They have to be used in its natural form and hence the spectrum of diseases covered is not wide spread. The advent of genetic engineering has enabled large scale production of existing and new products in disease treatment. The products from genetic engineering include:
Genetically engineered micro organisms:
Human gene has been known to encode a large number of pharmaceutically important proteins. These are cloned and expressed in micro organisms for increased production. Microbes are used as hosts in cloning purposes. E. coli, yeast are some of the most common examples of microbes which are used as hosts. In yeast many recombinant proteins having pharmaceutical significance has been produced. Eg: recombinant insulin used in the treatment of diabetes, human growth hormone for dwarfism, interferon, interleukin, granulocyte macrophage colony stimulating factor, etc.
The most extensive protein developed in such a manner is human insulin. It consists of two chains known as A and B which are interlinked by two disulphide bridges. The gene coding was integrated separately to a host cell, expressed and modified to produce functional insulin.
Animal cell cultures are also used for expression of human genes encoding pharmaceutically valuable proteins. The main proteins produced by this way are erythropoietin and blood clotting factor VIII. Plant cells producing recombinant proteins are high in demand as many ethical issues related to animal cell culture do not exist with the transgenic plants. In the case of transgenic plants, the process of retrieval of recombinant proteins from the parts of plant cells is comparatively easy. The most relevant example of transgenic plants aiding in the disease treatment is production of a polypeptide called hirudin. This is produced by a synthetic gene expressed in the plant Brassica napus. This is produced as a fusion protein with oleisn which is an oil body protein. Upon successful integration and extraction, the hirudin is extracted with water and later centrifuged to separate our protein from the rest of the proteins produced with the help of oil body. The pure hirudin is separated from olesin by subjecting the obtained oil moisture to proteolytic cleavage.
Antisense nucleotides:
A novel approach of disease treatment is the production of antisense oligonucleotide. It involves production and use of oligonucleotides complementary to the 5’ end of the parasite mRNAs. This antisense oligonucleotide is often linked with acridine for increasing the effectiveness of the same. The application of such oligonucleotides is in the case of cancer.
Monoclonal antibodies:
These have been known to exhibit several therapeutic applications like providing passive immunity, treatment of certain diseases like leprosy, deliver of immunotoxins specifically to cancer cells etc.
Drug designing:
This involves designing special drugs for special requirements of disease or the patient. These are designed to specifically bind to the critical site of target molecules thus inactivating the latter. These are so designed so that they do not exhibit any side effects rather than conventional drugs. Important examples are propanolol used in treatment of hypertension or heart attacks. Another example is cimetidine which blocks the hydrogen receptor in the stomach so that it effects the formation of ulcers in the stomach curing it. This has served as an important mechanism in treatment of cancer, gout, malaria, etc. Thos has resulted in developing a drug called azidothymidine (AZT) for treatment against HIV.
Drug delivery and targeting:
An effective improvement in the disease treatment is the introduction of technique of drug targeting. Often it is seen that conventional medicines loose their activity or sometimes part of their activity as they follow general distribution pattern. In drug targeting, the drugs are so targeted so that it affects only the required tissues and does not act upon anything else. This greatly enhances the drug effects and limits the amount of dosage required. Immunotoxins are the main example of such site directed delivery of drugs.
Gene therapy is yet another novel approach in the field of disease treatment with many successful examples in treating disease like cancer. Studies are being conducted on improving and developing the procedure for large scale use.
by ashwathi at 11-19-2012, 12:14 PM
0 comments
An embryo derived from a somatic cell of a plant rather than the zygote is known as somatic embryo. The process of production of somatic embryo is known as somatic embryogenesis. Micro propagation refers to the technique by which different meristem such as root, shoot, somatic embryos are utilized to produce new plants from them under controlled environmental conditions or in vitro. The regeneration refers to development of organised structures like root or shoot from culture cells or tissues. Somatic embryos when used in micropropagation and differentiation leads to formation of a whole new plant in vitro.
Mechanism of development of somatic embryos:
The development of somatic embryo by somatic embryogenesis occurs from a single cell through micropropagation of meristematic cell also known as explant. This single cell undergoes rapid division and differentiation to form a cluster of cells. This gets isolated by breaking of cytoplasmic connections between different cells of the cell mass. The highly active mass of meristematic cells of somatic embryos undergoes rapid changes by differentiation. It develops through different phases like globular, round shaped, heart shaped, torpedo shaped and finally cotyledonary stages to form a somatic embryo.
A somatic embryo consists of a shoot plumule and a root radicle. Often it is seen that, in a developing somatic embryo the shoot plumule is seen propagating outwards and the radicle towards the center of callus or cell mass. Thus in most cases, the developing embryo develops only shoot and undergo shoot regeneration. In order to regenerate root, this has to be induced with growth factors which promote root regeneration. The somatic embryos which are produced by the following were seen to be associated with abnormal developmental features like cotyledons which are more in number, abnormally shaped. This problem can be prevented by the addition of abscisic acid in the culture medium used to propagate somatic embryos.
The development of somatic embryos goes through various processes like somatic embryo induction phase where the induction is initiated in auxin medium to produce a mass of cells. This is then transferred into developmental medium low in auxin concentration where the cell develops into cotyledons. The cotyledons so produced enter a somatic embryo conversion phase to form embryos. These are mostly subjected to a maturation phase so that the somatic embryo formed gets stable.
In certain cases, the micro propagation of plants is possible only from somatic embryos such as oil palm, date palms etc. It is also recommended to micro propagate plants affected with virus of plant body by somatic embryos only.
The production of somatic embryos gets affected by factors like:
Growth regulators:
The presence of certain growth regulators is seen to influence the growth of somatic embryos. In most cases, the growth medium is added with an auxin which promotes development of somatic embryos. The presence of auxins promotes hypermethylation of DNA leading to the totipotency of the cell. In certain plants the presence of auxin is known to trigger the development of cells so that they divide asymmetrically and the daughter cells produced by each division sticks together to form a clump of cells known as proembryogenic masses or embryogenic clumps. These can be differentiated and each cell can be developed to produce a somatic embryo. Totipotent cells, which have the ability to divide and differentiate, release some glycoproteins into the medium when they differentiate. This glycoprotein when isolated and added to medium of cell cluster was found to initiate differentiation leading to somatic embryogenesis. These glycoproteins produced are known as arabinogalactan proteins.
Several other factors are also known to influence the growth of somatic embryos like nitrogen source, genotype of explant used, high potassium levels, dissolved oxygen level and even the presence of cytokinin in certain species.
Production of artificial seed:
Somatic embryo can be used to produce artificial seeds. It consists of a bead of gel containing somatic embryo along with nutrients, growth regulators, pesticides, antibiotics, all the necessary requirements needed by the embryo to develop into a new plantlet. It is produce by mainly two systems
Desiccated system: This involves hardening of the somatic embryo in the maturation phase by adding polymer or treating them with abscisic acid. This is followed by drying or desiccation to produce a desiccated system.
Hydrated system: This involves coating the embryos in a gel with materials similar to sodium alginate. The corresponding process involves allowing sodium alginate to fall into a solution of calcium chloride. The drop before falling is inserted with embryos thus it falls into the solution forming a gel coat around the embryo.
The hydrated system is less stable and has to be planted soon. It also undergoes hydration when it comes in contact with atmosphere thus by this process it has made possible to produce seeds which can be transported , stored and even planted to produce plants when required.
Mechanism of development of somatic embryos:
The development of somatic embryo by somatic embryogenesis occurs from a single cell through micropropagation of meristematic cell also known as explant. This single cell undergoes rapid division and differentiation to form a cluster of cells. This gets isolated by breaking of cytoplasmic connections between different cells of the cell mass. The highly active mass of meristematic cells of somatic embryos undergoes rapid changes by differentiation. It develops through different phases like globular, round shaped, heart shaped, torpedo shaped and finally cotyledonary stages to form a somatic embryo.
A somatic embryo consists of a shoot plumule and a root radicle. Often it is seen that, in a developing somatic embryo the shoot plumule is seen propagating outwards and the radicle towards the center of callus or cell mass. Thus in most cases, the developing embryo develops only shoot and undergo shoot regeneration. In order to regenerate root, this has to be induced with growth factors which promote root regeneration. The somatic embryos which are produced by the following were seen to be associated with abnormal developmental features like cotyledons which are more in number, abnormally shaped. This problem can be prevented by the addition of abscisic acid in the culture medium used to propagate somatic embryos.
The development of somatic embryos goes through various processes like somatic embryo induction phase where the induction is initiated in auxin medium to produce a mass of cells. This is then transferred into developmental medium low in auxin concentration where the cell develops into cotyledons. The cotyledons so produced enter a somatic embryo conversion phase to form embryos. These are mostly subjected to a maturation phase so that the somatic embryo formed gets stable.
In certain cases, the micro propagation of plants is possible only from somatic embryos such as oil palm, date palms etc. It is also recommended to micro propagate plants affected with virus of plant body by somatic embryos only.
The production of somatic embryos gets affected by factors like:
Growth regulators:
The presence of certain growth regulators is seen to influence the growth of somatic embryos. In most cases, the growth medium is added with an auxin which promotes development of somatic embryos. The presence of auxins promotes hypermethylation of DNA leading to the totipotency of the cell. In certain plants the presence of auxin is known to trigger the development of cells so that they divide asymmetrically and the daughter cells produced by each division sticks together to form a clump of cells known as proembryogenic masses or embryogenic clumps. These can be differentiated and each cell can be developed to produce a somatic embryo. Totipotent cells, which have the ability to divide and differentiate, release some glycoproteins into the medium when they differentiate. This glycoprotein when isolated and added to medium of cell cluster was found to initiate differentiation leading to somatic embryogenesis. These glycoproteins produced are known as arabinogalactan proteins.
Several other factors are also known to influence the growth of somatic embryos like nitrogen source, genotype of explant used, high potassium levels, dissolved oxygen level and even the presence of cytokinin in certain species.
Production of artificial seed:
Somatic embryo can be used to produce artificial seeds. It consists of a bead of gel containing somatic embryo along with nutrients, growth regulators, pesticides, antibiotics, all the necessary requirements needed by the embryo to develop into a new plantlet. It is produce by mainly two systems
Desiccated system: This involves hardening of the somatic embryo in the maturation phase by adding polymer or treating them with abscisic acid. This is followed by drying or desiccation to produce a desiccated system.
Hydrated system: This involves coating the embryos in a gel with materials similar to sodium alginate. The corresponding process involves allowing sodium alginate to fall into a solution of calcium chloride. The drop before falling is inserted with embryos thus it falls into the solution forming a gel coat around the embryo.
The hydrated system is less stable and has to be planted soon. It also undergoes hydration when it comes in contact with atmosphere thus by this process it has made possible to produce seeds which can be transported , stored and even planted to produce plants when required.
by ashwathi at 11-19-2012, 10:36 AM
1 comments
Altering the genes as a treatment against a disease is known as gene therapy. A variety of diseases has been known to be caused as a result of defective genes in humans such as Parkinson’s disease, cystic fibrosis, haemophilia, cancer etc. Thus a change in the genes can be used as a treatment mechanism for treating the diseases.
Several modes of mechanism are followed in gene therapy:
(i) Replacement: In this therapy, the defective gene is replaced with a properly functioning one. In certain cases the diseases may be caused by loss of certain genes as a result of mutation, or the diseased condition can arise due to the genes being permanently turned off.
(ii) Regulation: Certain regulations or alterations in genes leading to decline of certain important functions or activation of some defective function can be the cause of the disease. Appropriate regulations of gene expression can lead to proper gene expression and treatment of the disease.
(iii) Enhancement of defective cell appearance: Certain disease can be caused as a result of the defective cell being not recognised by the immune system. The gene therapy is targeted so that these cells become distinct and the same is recognised by the immune system and acted upon them.
In gene therapy, a gene cannot be inserted directly into a human cell. It needs specific carriers which are known as ‘vectors’ which carry these genes into the cell. In gene therapy, viruses are mainly used as vectors.
Depending on the target cell, the gene therapy can be divided into two main types:-
Germline gene therapy and Somatic cell gene therapy.
In germline gene therapy, the gene transfer is targeted to germ cells and the modification of genes in the same is acquired. This results in transfer of modified genes into the future generations. This can help in eradicating certain diseases from a family or from a population as a whole. But this process has been so far possible only theoretically. The dangerous implications of the proposed methodology have inhibited it from being acquiring acceptance.
In somatic gene therapy, the gene is introduced into somatic cells of the diseased. The gene is introduced into the somatic cells where the expression of critical genes is important for restoration of specific cellular activity. Since somatic cells are non reproductive this change in the genes are not transferred into the next generations and remain in the same species.
Mode of action:
In gene therapy, mostly a normal gene is replaced in the position of a defective gene. This transfer of corrected gene is done with the help of carriers known as vectors. The most common vector used in these cases is viruses which have been genetically altered so that it does not actually affect the person negatively but rather improves the diseased condition of the person. The vectors are directed to infect target cells that are cells where a defective gene is present and the corrected genetic material is unloaded into the defective cell. The correction of the defects helps in restoration of the defective condition.
Cancer treatment by gene therapy:-
Gene therapy has been applied most successfully in the treatment of cancer. The property of selective targeting and tumour destruction is the most prominent accounting to its use in cancer cure. A main example is defective P53 gene in tumour cell. The P53 gene is a tumour suppressor gene. It is seen that in persons with tumour, the P53 gene has been affected with mutations and is non functional. Introduction of wild type gene by gene therapy into the affected persons restores the functional gene and results in death of tumour cells.
Another major example in gene therapy in cancer cure is regulation of K-RAS. This is an oncogene known for causing cancer. In cancerous condition, the over expression of the corresponding gene is reported. Gene therapy facilitates introducing antisense gene into the cell over expressing this gene. This causes silencing of the corresponding gene by formation of double stranded RNA affecting the protein production and expression.
The process also involves several risk factors the main one being instability of viruses. The viruses which are used as vectors may develop its infectious property and lead to toxicity, immune responses from the body or the accidental integration into some other site will lead to lethal conditions.
Several modes of mechanism are followed in gene therapy:
(i) Replacement: In this therapy, the defective gene is replaced with a properly functioning one. In certain cases the diseases may be caused by loss of certain genes as a result of mutation, or the diseased condition can arise due to the genes being permanently turned off.
(ii) Regulation: Certain regulations or alterations in genes leading to decline of certain important functions or activation of some defective function can be the cause of the disease. Appropriate regulations of gene expression can lead to proper gene expression and treatment of the disease.
(iii) Enhancement of defective cell appearance: Certain disease can be caused as a result of the defective cell being not recognised by the immune system. The gene therapy is targeted so that these cells become distinct and the same is recognised by the immune system and acted upon them.
In gene therapy, a gene cannot be inserted directly into a human cell. It needs specific carriers which are known as ‘vectors’ which carry these genes into the cell. In gene therapy, viruses are mainly used as vectors.
Depending on the target cell, the gene therapy can be divided into two main types:-
Germline gene therapy and Somatic cell gene therapy.
In germline gene therapy, the gene transfer is targeted to germ cells and the modification of genes in the same is acquired. This results in transfer of modified genes into the future generations. This can help in eradicating certain diseases from a family or from a population as a whole. But this process has been so far possible only theoretically. The dangerous implications of the proposed methodology have inhibited it from being acquiring acceptance.
In somatic gene therapy, the gene is introduced into somatic cells of the diseased. The gene is introduced into the somatic cells where the expression of critical genes is important for restoration of specific cellular activity. Since somatic cells are non reproductive this change in the genes are not transferred into the next generations and remain in the same species.
Mode of action:
In gene therapy, mostly a normal gene is replaced in the position of a defective gene. This transfer of corrected gene is done with the help of carriers known as vectors. The most common vector used in these cases is viruses which have been genetically altered so that it does not actually affect the person negatively but rather improves the diseased condition of the person. The vectors are directed to infect target cells that are cells where a defective gene is present and the corrected genetic material is unloaded into the defective cell. The correction of the defects helps in restoration of the defective condition.
Cancer treatment by gene therapy:-
Gene therapy has been applied most successfully in the treatment of cancer. The property of selective targeting and tumour destruction is the most prominent accounting to its use in cancer cure. A main example is defective P53 gene in tumour cell. The P53 gene is a tumour suppressor gene. It is seen that in persons with tumour, the P53 gene has been affected with mutations and is non functional. Introduction of wild type gene by gene therapy into the affected persons restores the functional gene and results in death of tumour cells.
Another major example in gene therapy in cancer cure is regulation of K-RAS. This is an oncogene known for causing cancer. In cancerous condition, the over expression of the corresponding gene is reported. Gene therapy facilitates introducing antisense gene into the cell over expressing this gene. This causes silencing of the corresponding gene by formation of double stranded RNA affecting the protein production and expression.
The process also involves several risk factors the main one being instability of viruses. The viruses which are used as vectors may develop its infectious property and lead to toxicity, immune responses from the body or the accidental integration into some other site will lead to lethal conditions.
by Kamat2010 at 11-18-2012, 09:45 PM
2 comments
Nanomaterials (NMs) have been defined as particles having one dimension less than 100nm. Among them, the materials with atleast two dimensions between 1 and 100 nm are known as nanoparticles (NPs). In the environment, nanoparticles always exist from different sources both natural as well as anthropogenic and are referred to by many names for traditional use. In air, they are referred to as ultra fine particles and as colloids with different range of size in soil and water systems. In the urban areas, different combustion sources including diesel and gasoline fueled vehicles have contributed a high percentage of different particulate matter including nanoparticles that amount to almost 36% of the total particulate number concentrations. The effect of the nanoscale particulate matter on health especially the respiratory system is being investigated. In comparison to the studies on the ecological systems, the research on human health has focused on various adverse effects that include inflammatory and fibrotic reactions as well as oxidative stress.
Apart from the natural sources of the nanomaterials present in the environment like colloids in soil and water, the manufacture of synthetic nanomaterials has also contributed to the increase in the amount of the nanoparticles present in the environment. The unique properties of the nanomaterials such as mechanical, optical, electrical conductivity, catalytic, etc due to their size in nanoscale has resulted in an exponential growth in the development of various engineered and manufactured nanomaterials for their exploitation in different fields. The development of a wide range of nanomaterials including carbon nanotubes, nanopolymers, quantum dots, dendrimers, nanofibers, nanowires, etc are constantly expanding the synthetic preparation of the NPs. Due to the tremendous increase in the production of NMs, their release into the environment affects the ecosystem health, which is an increasing concern for the regulatory authorities. It necessitates the setting of different guidelines that will give adequate environmental protection as well as help in the growth and development of nanotechnology.
The effect of the accumulation of NMs after uptake is not clearly known, as much research has not been conducted in this area. However, it is assumed that the different organisms living in the environments loaded with NPs would incorporate the NPs within their bodies mainly through the gut, which then gives rise to the possibility of their translocation within the body. Various ecotoxicological studies have been conducted on the different animal models e.g. daphnids. Uptake of the NPs and their translocation from the gut to the reserve fat droplets has been demonstrated successfully. However, the exact mechanism of the whole process is still under investigation. It has been suggested that the entry of NPs is also possible by diffusion through the plasma membranes as well as by endocytosis or adhesion processes.
The release of the NPs into the environment could be intentional or unintentional. The intentional release includes the release of iron NPs into the groundwater for remediation and is controlled in nature. However, the unintentional release of the NPs includes the emissions in atmosphere as well as the solid or liquid waste streams from the production facilities and is uncontrolled. The NPs present in fabric, health care products, cosmetics, etc also enter the environment proportional to the use of the products. Although, the toxicity mechanisms related to the NMs have not been completely elucidated, the different cellular mechanisms in the human body in which the NMs may have adverse effect include
a) the disruption of cell membranes leading to loss of membrane integrity;
b) protein oxidation and loss of structure and function of proteins;
c) genotoxicity due to damage in nucleic acids;
d) energy transduction interruption and disruption in intracellular communication;
e) reactive oxygen species (ROS) formation leading to cell damage; and
f) release of toxic components
Ecotoxicological studies on other aquatic organisms and microorganisms have shown the toxic effects of NPs. In case of microorganisms, they have been found to inhibit their growth acting as antibacterial agents and are toxic to other microorganisms due to the formation of ROS species. In case of other aquatic animals, they have been found to accelerate the lipid peroxidation in the brain acting as neurotoxins and causing changes in the gene expression as well as affecting the developmental stages of the animals post fertilization. The toxicity studies of NPs on soil faces a number of issues due to the presence of manufactured as well as natural NPs that limit the knowledge regarding the effect of different NPs on soil and terrestrial plants. Hence, in-depth study related to the interaction of the NPs with the soil components is essential. The repercussions of the interactions between the NPs and natural organic matter on the fate of ecosystem can be known by the study of the behaviour, bioavailability and characterization of the NPs.
Apart from the natural sources of the nanomaterials present in the environment like colloids in soil and water, the manufacture of synthetic nanomaterials has also contributed to the increase in the amount of the nanoparticles present in the environment. The unique properties of the nanomaterials such as mechanical, optical, electrical conductivity, catalytic, etc due to their size in nanoscale has resulted in an exponential growth in the development of various engineered and manufactured nanomaterials for their exploitation in different fields. The development of a wide range of nanomaterials including carbon nanotubes, nanopolymers, quantum dots, dendrimers, nanofibers, nanowires, etc are constantly expanding the synthetic preparation of the NPs. Due to the tremendous increase in the production of NMs, their release into the environment affects the ecosystem health, which is an increasing concern for the regulatory authorities. It necessitates the setting of different guidelines that will give adequate environmental protection as well as help in the growth and development of nanotechnology.
The effect of the accumulation of NMs after uptake is not clearly known, as much research has not been conducted in this area. However, it is assumed that the different organisms living in the environments loaded with NPs would incorporate the NPs within their bodies mainly through the gut, which then gives rise to the possibility of their translocation within the body. Various ecotoxicological studies have been conducted on the different animal models e.g. daphnids. Uptake of the NPs and their translocation from the gut to the reserve fat droplets has been demonstrated successfully. However, the exact mechanism of the whole process is still under investigation. It has been suggested that the entry of NPs is also possible by diffusion through the plasma membranes as well as by endocytosis or adhesion processes.
The release of the NPs into the environment could be intentional or unintentional. The intentional release includes the release of iron NPs into the groundwater for remediation and is controlled in nature. However, the unintentional release of the NPs includes the emissions in atmosphere as well as the solid or liquid waste streams from the production facilities and is uncontrolled. The NPs present in fabric, health care products, cosmetics, etc also enter the environment proportional to the use of the products. Although, the toxicity mechanisms related to the NMs have not been completely elucidated, the different cellular mechanisms in the human body in which the NMs may have adverse effect include
a) the disruption of cell membranes leading to loss of membrane integrity;
b) protein oxidation and loss of structure and function of proteins;
c) genotoxicity due to damage in nucleic acids;
d) energy transduction interruption and disruption in intracellular communication;
e) reactive oxygen species (ROS) formation leading to cell damage; and
f) release of toxic components
Ecotoxicological studies on other aquatic organisms and microorganisms have shown the toxic effects of NPs. In case of microorganisms, they have been found to inhibit their growth acting as antibacterial agents and are toxic to other microorganisms due to the formation of ROS species. In case of other aquatic animals, they have been found to accelerate the lipid peroxidation in the brain acting as neurotoxins and causing changes in the gene expression as well as affecting the developmental stages of the animals post fertilization. The toxicity studies of NPs on soil faces a number of issues due to the presence of manufactured as well as natural NPs that limit the knowledge regarding the effect of different NPs on soil and terrestrial plants. Hence, in-depth study related to the interaction of the NPs with the soil components is essential. The repercussions of the interactions between the NPs and natural organic matter on the fate of ecosystem can be known by the study of the behaviour, bioavailability and characterization of the NPs.
by Kamat2010 at 11-18-2012, 03:54 AM
3 comments
Much advance has been made in the field of nanotechnology and nanomedicine, which has initiated the study of the use of robots in the nanometer scale known as nanorobots. The technology of nanorobots has become a raging topic and advanced research is being carried out for the use of robots in the therapeutics of various fatal diseases, for various biomedical applications and manipulations in nanomedicine. The building of biosensors and the nanokinetic devices are a major requirement in the operation and locomotion of nanorobots. Although, nanorobots remain to be a part of scientific fiction, they may have much clinical aspect in future medical diagnostics. Manipulation of nanorobots is a technology enabled by the NanoElectroMechanical Systems or NEMS. With various novel materials and structures in nanoscale, NEMS will help in the development of new nanosensors and nanoactuators.
The science of nanorobotics plays a vital role in the development of robots, whose structure is built by using nanoscale components and objects. The nature of the components being in the nano scale allows the researchers for the engineering of the mimic of human beings. The construction of the various complex parts, which constitute the robots have been possible due to nanorobotics. Nanobots, nanites, nanoids or nanomites are some of the hypothetical devices created with the knowledge of nanorobotics.
Various approaches have been used for the development of nanorobots such as
a) self-directed assembly as seen in the self-assembled monolayers, self-assembled lipidic micelles and vesicles, which follow the Brownian theory of self-assembly.
b) DNA-directed assembly using part of DNA for assembling, which works on the self-assembly principle of complementary base pairing and has application in the DNA based rotary motors.
c) Protein-directed assembly as is seen in genetically engineered chaperon proteins that help in the assembly of gold nanoparticles and CDSe semiconductor quantum dots into arrays in the nanoscale range. Ratchet action protein based molecular motors have also found much application in biology.
d) Microbes and virus directed assembly, which includes various bacteria that are incorporated into microelectromechanical systems (MEMS) and help in acting as living motors, pumps, etc. Viral capsid shells have also found application in acting as scaffolds for the assembly of the nanoparticles such as quantum dots.
The study of the nanorobots is creating wider applications in near future. A number of potential applications of the nanorobots have been brought forward such as
1. Transmigration of the WBC and other inflammatory cells to the inflamed tissues by attaching to them for accelerating the healing process.
2. Drug delivery nanorobots, known as ‘pharmacytes’ will be applied in future therapeutics related to cancer in chemotherapy for precise dosage administration of the chemicals as well as in the anti-HIV therapeutics.
3. Can be used as ancillary devices for processing different chemical reactions in the injured organs.
4. Can help in the control and monitor of glucose levels in diabetic patients.
5. They may be utilized for the targeting and destruction of kidney stones.
6. Can be applied in the therapeutics for atherosclerosis. The atherosclerotic plaques are localized mainly in the coronary arteries. The medical nanorobots may help in locating the atherosclerotic lesions in the stenosed blood vessels and help in their mechanical, chemical, or pharmacological treatment.
7. Nanodentistry is one of the unique applications, whereby nanorobots help in different processes involved in dentistry. They help in inducing oral anaesthesia, desensitization of tooth, manipulation of the tissue for the re-allignment and straightening of the irregular set of teeth and for the improvement of the teeth durability, major tooth repair, generation of nanofiller, improvement of appearance of teeth, etc.
8. Can help in surgery by using surgical nanorobots for nanomanipulation in the target site with programming and guidance from a surgeon.
9. Can find application in cryostasis i.e. reversal of freezing injury by introduction of cryoprotectants and other chemicals into the vascular system rapidly suing nanorobots.
10. Can help in the diagnosis and testing of different diseases and help in their monitoring by recording different biological variables such as temperature, pressure, activity of immune system, etc very rapidly at the target site after oral introduction of nanorobots.
11. Can help in gene therapy for different genetic diseases by helping in introducing different modifications and correction by editing in the right place in the DNA or the proteins attached to the DNA.
However, some disadvantages accompany the use of nanorobots. The complexity of the design and manufacture accompanied by high cost is a major drawback in its wide application. The other disadvantages are the possible anti-social applications that accompany every new discovery in science.
In spite of the drawbacks, the application of molecular nanotechnology may help in the development of therapeutics for different fatal diseases in future, thus creating a revolution in healthcare.
.
The science of nanorobotics plays a vital role in the development of robots, whose structure is built by using nanoscale components and objects. The nature of the components being in the nano scale allows the researchers for the engineering of the mimic of human beings. The construction of the various complex parts, which constitute the robots have been possible due to nanorobotics. Nanobots, nanites, nanoids or nanomites are some of the hypothetical devices created with the knowledge of nanorobotics.
Various approaches have been used for the development of nanorobots such as
a) self-directed assembly as seen in the self-assembled monolayers, self-assembled lipidic micelles and vesicles, which follow the Brownian theory of self-assembly.
b) DNA-directed assembly using part of DNA for assembling, which works on the self-assembly principle of complementary base pairing and has application in the DNA based rotary motors.
c) Protein-directed assembly as is seen in genetically engineered chaperon proteins that help in the assembly of gold nanoparticles and CDSe semiconductor quantum dots into arrays in the nanoscale range. Ratchet action protein based molecular motors have also found much application in biology.
d) Microbes and virus directed assembly, which includes various bacteria that are incorporated into microelectromechanical systems (MEMS) and help in acting as living motors, pumps, etc. Viral capsid shells have also found application in acting as scaffolds for the assembly of the nanoparticles such as quantum dots.
The study of the nanorobots is creating wider applications in near future. A number of potential applications of the nanorobots have been brought forward such as
1. Transmigration of the WBC and other inflammatory cells to the inflamed tissues by attaching to them for accelerating the healing process.
2. Drug delivery nanorobots, known as ‘pharmacytes’ will be applied in future therapeutics related to cancer in chemotherapy for precise dosage administration of the chemicals as well as in the anti-HIV therapeutics.
3. Can be used as ancillary devices for processing different chemical reactions in the injured organs.
4. Can help in the control and monitor of glucose levels in diabetic patients.
5. They may be utilized for the targeting and destruction of kidney stones.
6. Can be applied in the therapeutics for atherosclerosis. The atherosclerotic plaques are localized mainly in the coronary arteries. The medical nanorobots may help in locating the atherosclerotic lesions in the stenosed blood vessels and help in their mechanical, chemical, or pharmacological treatment.
7. Nanodentistry is one of the unique applications, whereby nanorobots help in different processes involved in dentistry. They help in inducing oral anaesthesia, desensitization of tooth, manipulation of the tissue for the re-allignment and straightening of the irregular set of teeth and for the improvement of the teeth durability, major tooth repair, generation of nanofiller, improvement of appearance of teeth, etc.
8. Can help in surgery by using surgical nanorobots for nanomanipulation in the target site with programming and guidance from a surgeon.
9. Can find application in cryostasis i.e. reversal of freezing injury by introduction of cryoprotectants and other chemicals into the vascular system rapidly suing nanorobots.
10. Can help in the diagnosis and testing of different diseases and help in their monitoring by recording different biological variables such as temperature, pressure, activity of immune system, etc very rapidly at the target site after oral introduction of nanorobots.
11. Can help in gene therapy for different genetic diseases by helping in introducing different modifications and correction by editing in the right place in the DNA or the proteins attached to the DNA.
However, some disadvantages accompany the use of nanorobots. The complexity of the design and manufacture accompanied by high cost is a major drawback in its wide application. The other disadvantages are the possible anti-social applications that accompany every new discovery in science.
In spite of the drawbacks, the application of molecular nanotechnology may help in the development of therapeutics for different fatal diseases in future, thus creating a revolution in healthcare.
.