Ultrafast Optical Switch
Indian researchers have made ultrafast optical switches using double-walled carbon nanotubes. They used pristine and molybdenum filled double walled carbon nanotubes (DWNTs) suspended in heavy water. Such designed DWNTs show excellent ultrafast optical switching properties using extremely short pulses of energy that lasts for 50 femtoseconds.
One femtosecond is a millionth of a nanosecond, which is one billionth of a second. DWNTs, two carbon atoms thick, yet conduct electricity. This quality makes them well-suited for advanced solar panels, sensors and a host of other applications. The findings of the study have been published in the 26th August 2009 issue Applied Physics Letters.
Friday, September 04, 2009
Optical Fibre on New Turf
Optical fibre has already been hailed for its role in revolutionizing communication. Now, researchers take optical fibre to new domain of application. An Indian research team has designed an analytical method using optical fibre. The fibre-optic part accommodates sample volume of 1 microlitre placed between the two ends of optical fibres.
LPME (Liquid-phase microextraction) using 25–30 microlitre of organic solvent was found to produce more sensitive results than SDME (single drop microextraction). The new technique as used in combination with sample handling techniques produced limits of detection of analytes which were better than obtained by previously reported spectrophotometry. The findings of the study have been published in the 26th August 2009 issue of Analytica Chimica Acta.
Optical fibre has already been hailed for its role in revolutionizing communication. Now, researchers take optical fibre to new domain of application. An Indian research team has designed an analytical method using optical fibre. The fibre-optic part accommodates sample volume of 1 microlitre placed between the two ends of optical fibres.
LPME (Liquid-phase microextraction) using 25–30 microlitre of organic solvent was found to produce more sensitive results than SDME (single drop microextraction). The new technique as used in combination with sample handling techniques produced limits of detection of analytes which were better than obtained by previously reported spectrophotometry. The findings of the study have been published in the 26th August 2009 issue of Analytica Chimica Acta.
Saturday, May 23, 2009
Just Another Species, Yet
Survival is a talent. Everyday we prove this. From waking up in the morning to going bed at night, we do chores of things that other animals don’t. For us, life is not just mere foraging for food and mating. Since we invented agriculture, we began to move away from nature. We gave up hunting and gathering and nomadic life. Groups of humans living together formed society. Initial knack of doing things spawned specialists who later gave rise to classes and professions.
Our forefathers came to know that agriculture and seasonal change are intricately linked. They culled seeds and knew which grow when. This knowledge in the shape of rudimentary agriculture was the first stepping stone of modern human civilization. Winter gives way to spring. And spring to summer. We yearn for every season. We have developed unique ability to adapt to any season. Humans have spread from North Pole to South Pole. Though we are dense around the equator, we show our dominance in temperate and colder regions.
Survival is a talent. Everyday we prove this. From waking up in the morning to going bed at night, we do chores of things that other animals don’t. For us, life is not just mere foraging for food and mating. Since we invented agriculture, we began to move away from nature. We gave up hunting and gathering and nomadic life. Groups of humans living together formed society. Initial knack of doing things spawned specialists who later gave rise to classes and professions.
Our forefathers came to know that agriculture and seasonal change are intricately linked. They culled seeds and knew which grow when. This knowledge in the shape of rudimentary agriculture was the first stepping stone of modern human civilization. Winter gives way to spring. And spring to summer. We yearn for every season. We have developed unique ability to adapt to any season. Humans have spread from North Pole to South Pole. Though we are dense around the equator, we show our dominance in temperate and colder regions.
Saturday, May 02, 2009
New Protective Shield against Cervical Cancer
A research team from Kolkata has discovered that an isothiocyanate compound in combination with sulphoraphane and anti-cancer drug could help battle out cervical cancer. Studies were performed to measure the degree of controlled cell death induced by either isothiocyanates alone, or in combination with adriamycin or etoposide (anti-cancer drugs). Death of cancer cells was evident from biochemical evidence. This effect of isothiocyanates might prove to be of considerable value in synergistic therapy of cervical cancer such that the drug dose level could be minimized. This research will be very significant as India bears the 25 per cent burden of global cervical cancer cases and natural isothiocyanates isolated from cruciferous vegetables are known to be effective chemopreventive agents and exhibit protective effect against cancers in a variety of target organs. The findings of the study have been published in the 12th April 2009 Molecular and Cellular Biochemistry.
A research team from Kolkata has discovered that an isothiocyanate compound in combination with sulphoraphane and anti-cancer drug could help battle out cervical cancer. Studies were performed to measure the degree of controlled cell death induced by either isothiocyanates alone, or in combination with adriamycin or etoposide (anti-cancer drugs). Death of cancer cells was evident from biochemical evidence. This effect of isothiocyanates might prove to be of considerable value in synergistic therapy of cervical cancer such that the drug dose level could be minimized. This research will be very significant as India bears the 25 per cent burden of global cervical cancer cases and natural isothiocyanates isolated from cruciferous vegetables are known to be effective chemopreventive agents and exhibit protective effect against cancers in a variety of target organs. The findings of the study have been published in the 12th April 2009 Molecular and Cellular Biochemistry.
Saturday, March 21, 2009
Silk Insect Could Yield Anti-fungal and Anti-bacterial Drugs
A research team from West Bengal has discovered that the wild insect called Antheraea mylitta which yields Indian tasar silk harbours a wide variety of proteins and peptides. These molecules possess potent anti-fungal and anti-bacterial activity to combat microbial attack, claims the research team. The researchers have found that the insect secrets a compound called AmFPI-1 that inhibits the activity of a fungal enzyme (secreted by Aspergillus oryzae) protecting against fungal infection. The study results will help design specific inhibitors against fungal enzymes. The findings of the research have been published in the April 2009 issue of Journal of Structural Biology.
A research team from West Bengal has discovered that the wild insect called Antheraea mylitta which yields Indian tasar silk harbours a wide variety of proteins and peptides. These molecules possess potent anti-fungal and anti-bacterial activity to combat microbial attack, claims the research team. The researchers have found that the insect secrets a compound called AmFPI-1 that inhibits the activity of a fungal enzyme (secreted by Aspergillus oryzae) protecting against fungal infection. The study results will help design specific inhibitors against fungal enzymes. The findings of the research have been published in the April 2009 issue of Journal of Structural Biology.
Tuesday, March 03, 2009
Mystery of Nanostripe Patterns of Aluminium Surface
An Indian research team has deciphered the mystery of microscopic origin of nanostripe patterns on electropolished surface of aluminium. Using sophisticated techniques like atomic force microscopy and computer-based simulations, the researchers have discovered that nanostripe patterns due to relaxation and reconstruction of the new surfaces exposed followed by textural changes at the surface. This is caused by dissolution during polishing on aluminium surface.
These insights will be very handy as electropolished samples have a wide range of industrial applications including the preparation of thin metal samples for transmission electron microscopy because electropolishing does not cause mechanical deformation of surface layers usually observed when mechanical polishing is used. The findings of the study have been published in the 4th March 2009 issue of Nanotechnology.
An Indian research team has deciphered the mystery of microscopic origin of nanostripe patterns on electropolished surface of aluminium. Using sophisticated techniques like atomic force microscopy and computer-based simulations, the researchers have discovered that nanostripe patterns due to relaxation and reconstruction of the new surfaces exposed followed by textural changes at the surface. This is caused by dissolution during polishing on aluminium surface.
These insights will be very handy as electropolished samples have a wide range of industrial applications including the preparation of thin metal samples for transmission electron microscopy because electropolishing does not cause mechanical deformation of surface layers usually observed when mechanical polishing is used. The findings of the study have been published in the 4th March 2009 issue of Nanotechnology.
Monday, February 16, 2009
DNA-based Diagnosis and Therapy
An Indian research team has deciphered the effects of a novel molecule when it was delivered into the helical structure of nucleic acids (DNA). Known as ‘thioacetamido linkage’ (TANA), the linker is an extended five-atom amide linker as opposed to four-atom phosphodiester linker backbone present in the DNA. Using sophisticated analytical techniques, it was observed that TANA destabilizes the helical structure of DNA.
The results of the study will widen our understanding on the nature and strength of forces that stabilize nucleic acids and facilitate the development of databases having potential applications in nucleic acid-based diagnostic and therapeutic protocols. The findings of the study have been published in the 6th February 2009 online issue of Journal of Medicinal Chemistry.
An Indian research team has deciphered the effects of a novel molecule when it was delivered into the helical structure of nucleic acids (DNA). Known as ‘thioacetamido linkage’ (TANA), the linker is an extended five-atom amide linker as opposed to four-atom phosphodiester linker backbone present in the DNA. Using sophisticated analytical techniques, it was observed that TANA destabilizes the helical structure of DNA.
The results of the study will widen our understanding on the nature and strength of forces that stabilize nucleic acids and facilitate the development of databases having potential applications in nucleic acid-based diagnostic and therapeutic protocols. The findings of the study have been published in the 6th February 2009 online issue of Journal of Medicinal Chemistry.
Sunday, February 15, 2009
New Carving Tool for Nanodevices
An Indian research team has devised a new method to produce uniform metallic coats on the surfaces of nanostructures. The method which utilizes scattered Ga ions to decompose organometallic molecules delivers metallic coats on nano-sized structures which are not accessible to the primary beam. The method can be used to provide electrical contacts on inaccessible regions of prototype nanodevices, such as ion batteries, electrophoresis cells, and cantilevers. The findings of the study have been published in the 18th February 2009 issue of Nanotechnology.
An Indian research team has devised a new method to produce uniform metallic coats on the surfaces of nanostructures. The method which utilizes scattered Ga ions to decompose organometallic molecules delivers metallic coats on nano-sized structures which are not accessible to the primary beam. The method can be used to provide electrical contacts on inaccessible regions of prototype nanodevices, such as ion batteries, electrophoresis cells, and cantilevers. The findings of the study have been published in the 18th February 2009 issue of Nanotechnology.
Saturday, January 17, 2009
Probeless Deposit of Nanomaterials
An Indian research team has developed electron-beam-induced deposition method to deposit tiny structures without the need of fine probes. The method relies on the build-up of surface potential on an insulating surface exposed to an electron beam. Feature sizes as small as 20 nm can be deposited without the need to use fine probes. This helps overcome the limitation of probe size imposed on the resolution. The use of pure metal vapor also renders the process inherently clean, say the researchers in the 29th September 2008 issue of Applied Physics Letters.
An Indian research team has developed electron-beam-induced deposition method to deposit tiny structures without the need of fine probes. The method relies on the build-up of surface potential on an insulating surface exposed to an electron beam. Feature sizes as small as 20 nm can be deposited without the need to use fine probes. This helps overcome the limitation of probe size imposed on the resolution. The use of pure metal vapor also renders the process inherently clean, say the researchers in the 29th September 2008 issue of Applied Physics Letters.
Wednesday, January 14, 2009
Morphine Could Cure TB
A research team from National Institute of Pharmaceutical Education and Research has discovered that morphine could battle out tuberculosis infection in mice. The team found that morphine exerted maximum effect at a dose of 5 mg per kg body weight of the mice.
Morphine boosted the immune cells of mice and initiated macrophage-mediated protective mechanism against mice tuberculosis. The study has shown that morphine alleviated mice tuberculosis infection at a dose dependent manner. The study results might be helpful in developing new opioid-like chemicals against tuberculosis, write the researchers in 30 January 2008 issue of Life Sciences.
Every second someone new is infected with TB. Overall, one-third of the world’s population is currently infected with TB. People with HIV and TB infection are much more likely to develop TB. In 2005, 8.8 million people fell ill with TB and 1.6 million died from it. TB is primarily a disease of people living in the developing world: 98% of TB deaths are in low- and medium-income countries. But no country is TB-free.
The World Health Organization (WHO) estimates that the largest number of new TB cases in 2005 occurred in the South-East Asia Region, which accounted for 34% of incident cases globally. However, the estimated incidence rate in sub-Saharan Africa is nearly twice that of the South-East Asia Region, at nearly 350 cases per 100 000 population. Add to it emergence of drug resistant TB bugs. Under these circumstances, the present study is important as it highlights a novel way out to get rid of TB.
A research team from National Institute of Pharmaceutical Education and Research has discovered that morphine could battle out tuberculosis infection in mice. The team found that morphine exerted maximum effect at a dose of 5 mg per kg body weight of the mice.
Morphine boosted the immune cells of mice and initiated macrophage-mediated protective mechanism against mice tuberculosis. The study has shown that morphine alleviated mice tuberculosis infection at a dose dependent manner. The study results might be helpful in developing new opioid-like chemicals against tuberculosis, write the researchers in 30 January 2008 issue of Life Sciences.
Every second someone new is infected with TB. Overall, one-third of the world’s population is currently infected with TB. People with HIV and TB infection are much more likely to develop TB. In 2005, 8.8 million people fell ill with TB and 1.6 million died from it. TB is primarily a disease of people living in the developing world: 98% of TB deaths are in low- and medium-income countries. But no country is TB-free.
The World Health Organization (WHO) estimates that the largest number of new TB cases in 2005 occurred in the South-East Asia Region, which accounted for 34% of incident cases globally. However, the estimated incidence rate in sub-Saharan Africa is nearly twice that of the South-East Asia Region, at nearly 350 cases per 100 000 population. Add to it emergence of drug resistant TB bugs. Under these circumstances, the present study is important as it highlights a novel way out to get rid of TB.
Saturday, January 10, 2009
Black Carbon – A Menace
Recent study suggests that black carbon deposition in Arctic regions may contribute to global warming by reducing the albedo of snow. This not only reduces the amount of solar energy reflected by snow in Arctic regions, but also increases the rate of snow melt, revealing dark substrates like vegetation and soil earlier in the year and thus amplifying black carbon’s effect on climate.
And also new observations show that in some regions black carbon is as culpable as CO2 for the warming, and in some cases, has a greater effect. In the winter and spring, heavily polluted air masses are transported over the Indian Ocean from central Asia, where the majority of black carbon is from cooking fires. Black carbon has been found to be part of brown cloud hovering over the Indian Ocean and it also contributes to warming of atmosphere.
Recent study suggests that black carbon deposition in Arctic regions may contribute to global warming by reducing the albedo of snow. This not only reduces the amount of solar energy reflected by snow in Arctic regions, but also increases the rate of snow melt, revealing dark substrates like vegetation and soil earlier in the year and thus amplifying black carbon’s effect on climate.
And also new observations show that in some regions black carbon is as culpable as CO2 for the warming, and in some cases, has a greater effect. In the winter and spring, heavily polluted air masses are transported over the Indian Ocean from central Asia, where the majority of black carbon is from cooking fires. Black carbon has been found to be part of brown cloud hovering over the Indian Ocean and it also contributes to warming of atmosphere.
Saturday, December 20, 2008
Venomous Remedy for Brittle Bone
A research team from Kolkata has stumbled upon the antiosteoporosis activity of the Indian black scorpion (Heterometrus bengalensis). In studies with rats, the researchers found that scorpion venom significantly restored the osteoporosis changes of urine, blood and bone. The scorpion venom also restored the bone dimensions, morphology and histological changes. This study confirms that the Indian black scorpion venom may influence bone-remodeling process by stimulating bone formation and reducing bone resorption process of osteogenesis (formation of bone cells). The findings of the study have been published in the 19th October 2008 online issue of Toxicon.
A research team from Kolkata has stumbled upon the antiosteoporosis activity of the Indian black scorpion (Heterometrus bengalensis). In studies with rats, the researchers found that scorpion venom significantly restored the osteoporosis changes of urine, blood and bone. The scorpion venom also restored the bone dimensions, morphology and histological changes. This study confirms that the Indian black scorpion venom may influence bone-remodeling process by stimulating bone formation and reducing bone resorption process of osteogenesis (formation of bone cells). The findings of the study have been published in the 19th October 2008 online issue of Toxicon.
Saturday, February 09, 2008
Eco-friendly Printing Ink
Printing ink from vegetable oils is a good replacement for the mineral-based ink used currently. Vegetable oil is environment friendly, claims a study. “It will reduce the organic compounds released during printing,” says Santinath Ghosh from the department of Chemical Technology at the Calcutta University.
“Volatile organic compounds leads to formation of smog in printing units, which pose serious health hazards to workers,” says Ghosh who led a joint research team from the university and Kolkata-based dic India Limited. dic is the biggest manufacturer of natural ink in the country. The volatile organic compound also affects the ozone layer.
The study says that the ink is more stable than its mineral-based counterpart.
It dries faster and gives a good image quality. It also helps conserve non-renewable petroleum oils. Mineral oil-based ink uses non-renewable petroleum oils, which make up for 30 per cent of the offset printing inks in the graphic art industry.
For the study, the team developed several printing inks using vegetable oils such as rapeseed, soybean, palm oil and rice bran, and mixing other chemical ingredients such as phenolic-resins and polyethylene wax paste. Resins were added to the vegetable oil.
When the results were compared, it was found that the products using vegetable oils—rice bran oil and palm oil—produced better results in terms of stability, and quality of print. Although the cost of the ink will be 8-10 per cent more than mineral oil-based product, it will avoid a lot of occupational problems, including improving the health of printing workers.
The above article was originally published in 15 January 2008 issue of Down To Earth, a science and environment fortnightly
Printing ink from vegetable oils is a good replacement for the mineral-based ink used currently. Vegetable oil is environment friendly, claims a study. “It will reduce the organic compounds released during printing,” says Santinath Ghosh from the department of Chemical Technology at the Calcutta University.
“Volatile organic compounds leads to formation of smog in printing units, which pose serious health hazards to workers,” says Ghosh who led a joint research team from the university and Kolkata-based dic India Limited. dic is the biggest manufacturer of natural ink in the country. The volatile organic compound also affects the ozone layer.
The study says that the ink is more stable than its mineral-based counterpart.
It dries faster and gives a good image quality. It also helps conserve non-renewable petroleum oils. Mineral oil-based ink uses non-renewable petroleum oils, which make up for 30 per cent of the offset printing inks in the graphic art industry.
For the study, the team developed several printing inks using vegetable oils such as rapeseed, soybean, palm oil and rice bran, and mixing other chemical ingredients such as phenolic-resins and polyethylene wax paste. Resins were added to the vegetable oil.
When the results were compared, it was found that the products using vegetable oils—rice bran oil and palm oil—produced better results in terms of stability, and quality of print. Although the cost of the ink will be 8-10 per cent more than mineral oil-based product, it will avoid a lot of occupational problems, including improving the health of printing workers.
The above article was originally published in 15 January 2008 issue of Down To Earth, a science and environment fortnightly
Monday, November 05, 2007
Sunderbans polluted: Persistent organic pollutants found
Rising sea level and erosion aside, the Sundarbans now face a new threat. An international research team has detected polybrominated diphenyl ethers (pbde), a persistent organic pollutant, in the core sediment from seven sites in the wetland. pbdes are used as flame-retardants in electrical equipments, plastics, textiles, building materials, vehicles and aircraft industries. Earlier research has established that pbdes can be persistent, bioaccumulative and toxic. They can cause liver and neuro-developmental toxicity and affect thyroid hormone levels.
“The huge discharge of municipal wastewater along with local industries’ waste may have contributed to elevated levels of pbdes. The presence of several textile plants along the upper stretch of Hooghly estuary indicates local use of pbde formulates for textile production,” says Santosh Kumar Sarkar, a co-researcher at the department of marine sciences in the Calcutta University, in a study published in the recent issue of Marine Pollution Bulletin (Vol 54, No 8).
Sarkar says, among the 12 kinds of pbdes found, the penta-bde mixture is most dangerous. “We will give due emphasis on the risks of exposure to wildlife species and humans now,” he adds. He feels the results will help monitor the wetland for more persistent organic pollutants.
The above article was originally written by this blogger and published in the 15th October 2007 issue of Down To Earth, a science and environment fortnightly published from New Delhi
Rising sea level and erosion aside, the Sundarbans now face a new threat. An international research team has detected polybrominated diphenyl ethers (pbde), a persistent organic pollutant, in the core sediment from seven sites in the wetland. pbdes are used as flame-retardants in electrical equipments, plastics, textiles, building materials, vehicles and aircraft industries. Earlier research has established that pbdes can be persistent, bioaccumulative and toxic. They can cause liver and neuro-developmental toxicity and affect thyroid hormone levels.
“The huge discharge of municipal wastewater along with local industries’ waste may have contributed to elevated levels of pbdes. The presence of several textile plants along the upper stretch of Hooghly estuary indicates local use of pbde formulates for textile production,” says Santosh Kumar Sarkar, a co-researcher at the department of marine sciences in the Calcutta University, in a study published in the recent issue of Marine Pollution Bulletin (Vol 54, No 8).
Sarkar says, among the 12 kinds of pbdes found, the penta-bde mixture is most dangerous. “We will give due emphasis on the risks of exposure to wildlife species and humans now,” he adds. He feels the results will help monitor the wetland for more persistent organic pollutants.
The above article was originally written by this blogger and published in the 15th October 2007 issue of Down To Earth, a science and environment fortnightly published from New Delhi
Sunday, July 29, 2007
Human Urine Aids the Growth of Fish Food Organism
A research team from West Bengal has discovered that human urine could be an excellent liquid waste aid in the mass production of fish food organism called Moina micrura, a type of zooplankton. The team studied the nutrient potentials of human urine and then compared its efficacy with other waste products like cow urine, human-cow mixed urine, vermin-compost, cow dung, poultry droppings and mixed wastes (vermin-cow-poultry) for the mass culture of M. micrura in 24 outdoor tanks.
The team found that the newly born M. micrura held in the treatment with human urine started reproduction at least 4 days earlier than other solid wastes. Total number of M. micrura counted in the culture tank, related with offspring production per life span, was maximum in case of human urine treatment, followed by human–cow mixed urine, cow urine, vermin-compost, poultry droppings, mixed wastes (vermin–cow–poultry), cow dung and control treatments.
The relationship between the total offspring production per female per life span and the nitrogen content of water in different treatments implied that human urine can be used for the mass production of zooplankton Moina micrura required for larval and post larval rearing of commercial fishes, write the researchers in a recent issue of Ecological Engineering.
A research team from West Bengal has discovered that human urine could be an excellent liquid waste aid in the mass production of fish food organism called Moina micrura, a type of zooplankton. The team studied the nutrient potentials of human urine and then compared its efficacy with other waste products like cow urine, human-cow mixed urine, vermin-compost, cow dung, poultry droppings and mixed wastes (vermin-cow-poultry) for the mass culture of M. micrura in 24 outdoor tanks.
The team found that the newly born M. micrura held in the treatment with human urine started reproduction at least 4 days earlier than other solid wastes. Total number of M. micrura counted in the culture tank, related with offspring production per life span, was maximum in case of human urine treatment, followed by human–cow mixed urine, cow urine, vermin-compost, poultry droppings, mixed wastes (vermin–cow–poultry), cow dung and control treatments.
The relationship between the total offspring production per female per life span and the nitrogen content of water in different treatments implied that human urine can be used for the mass production of zooplankton Moina micrura required for larval and post larval rearing of commercial fishes, write the researchers in a recent issue of Ecological Engineering.
Wednesday, July 25, 2007
A Potential Remedy for Malignant Malaria
A research team from Kolkata has discovered a complex organic compound that inhibits the activity of an enzyme that is essential for the survival and growth of Plasmodium falciparum, a parasite that causes malignant malaria in humans. According to the research team, the compound called hexadecyltrimethylammonium bromide (HDTAB) disrupted the activity of the enzyme called choline kinase, an enzyme which plays vital role in the biosynthesis of the most essential phospholipid, phosphatidylcholine in P. falciparum.
HDTAB inhibited P. falciparum choline kinase (PfCK) in a dose-dependent manner and offered very potent antimalarial activity in lab studies against P. falciparum. Furthermore, the antimalarial activity of HDTAB paralleled the decrease in phosphatidylcholine content, which was found to correlate with the decreased phosphocholine generation. These results suggest that inhibition of choline kinase by HDTAB leads to decreased phosphocholine, which in turn causes a decrease in phosphatidylcholine biosynthesis, resulting in death of the parasite.
Moreover, HDTAB exhibited profound antimalarial activity in vivo against the rodent malaria parasite Plasmodium yoelii (N-67 strain). Interestingly, parasites at the trophozoite and schizont stages were found to be particularly sensitive to HDTAB, write the researchers in a recent issue of Antimicrobial Agents and Chemotherapy.
Malaria is still a burning problem in India and other developing countries and second biggest killer after tuberculosis. Till November 2006, nearly 1.04 million Indians were afflicted with malaria. Of all the malaria cases, .46 million cases were P. falciparum cases. Some of the states like MP, Orissa, A.P., West Bengal, Gujarat, North Eastern States, Bihar and Maharashtra are highly endemic for P. falciparum and these states contribute around 97 per cent of the total P. falciparum cases in the country.
Since the 1990s, malaria returned with vengeance. The new obstacles have been resistance in P. falciparum to chloroquine and other anti-malarial drugs and human resistance to chemical control of vectors. Malaria control has become a complex enterprise.
Malaria also causes huge economic loss in a country like India. India has spent up to 25 per cent of its health budget on malaria control from 1977-1997. In 1997, India also started a five-year program for malaria control aimed to target 100 districts where 80 per cent of all P. falciparum cases occur.
A research team from Kolkata has discovered a complex organic compound that inhibits the activity of an enzyme that is essential for the survival and growth of Plasmodium falciparum, a parasite that causes malignant malaria in humans. According to the research team, the compound called hexadecyltrimethylammonium bromide (HDTAB) disrupted the activity of the enzyme called choline kinase, an enzyme which plays vital role in the biosynthesis of the most essential phospholipid, phosphatidylcholine in P. falciparum.
HDTAB inhibited P. falciparum choline kinase (PfCK) in a dose-dependent manner and offered very potent antimalarial activity in lab studies against P. falciparum. Furthermore, the antimalarial activity of HDTAB paralleled the decrease in phosphatidylcholine content, which was found to correlate with the decreased phosphocholine generation. These results suggest that inhibition of choline kinase by HDTAB leads to decreased phosphocholine, which in turn causes a decrease in phosphatidylcholine biosynthesis, resulting in death of the parasite.
Moreover, HDTAB exhibited profound antimalarial activity in vivo against the rodent malaria parasite Plasmodium yoelii (N-67 strain). Interestingly, parasites at the trophozoite and schizont stages were found to be particularly sensitive to HDTAB, write the researchers in a recent issue of Antimicrobial Agents and Chemotherapy.
Malaria is still a burning problem in India and other developing countries and second biggest killer after tuberculosis. Till November 2006, nearly 1.04 million Indians were afflicted with malaria. Of all the malaria cases, .46 million cases were P. falciparum cases. Some of the states like MP, Orissa, A.P., West Bengal, Gujarat, North Eastern States, Bihar and Maharashtra are highly endemic for P. falciparum and these states contribute around 97 per cent of the total P. falciparum cases in the country.
Since the 1990s, malaria returned with vengeance. The new obstacles have been resistance in P. falciparum to chloroquine and other anti-malarial drugs and human resistance to chemical control of vectors. Malaria control has become a complex enterprise.
Malaria also causes huge economic loss in a country like India. India has spent up to 25 per cent of its health budget on malaria control from 1977-1997. In 1997, India also started a five-year program for malaria control aimed to target 100 districts where 80 per cent of all P. falciparum cases occur.
Sunday, July 22, 2007
Herbal Cure for Amoebiasis
Indian camphorweed, that grows in lowlands and swamps, may hold the key to a cure for amoebiasis, a disease caused by the parasite Entamoeba histolytica that mostly hits the poor. A team of researchers from Jadavpur University and Indian Institute of Chemical Biology, both in Kolkata, have isolated a compound from the root of this plant that stops the growth of the parasite.
Among the seven compounds isolated from the root extract of the shrub (Pluchea indica) is r/j/3.
“This pure compound, chemically a thiophene derivative, was most effective in checking the proliferation of the parasites,” says lead researcher Tapan Kumar Chatterjee.
This could be a potent anti-amoebic drug, he says. The findings of the study will be published in a forthcoming issue of Phytomedicine.
The researchers took a virulent strain (hm1) of E histolytica and cultured trophozoites, the stage in which the parasite resides in the intestine and causes symptoms of amoebiasis. Then they exposed the trophozoites to varying doses of the pure compound.
r/j/3 showed optimum result at a dose of 0.00005 gm per ml. Two hours after administration, it caused granulation in the trophozoites. In four hours, the trophozoites were completely broken down. r/j/3 acted slower than synthetic drugs like metronidazole. “But being a plant product, it is safe and non-toxic. Metronidazole is very toxic and parasites are sometimes resistant to it,” Chatterjee says.
The above article was originally published in Down To Earth, a science and environment fortnightly published from New Delhi and written by this blogger.
Indian camphorweed, that grows in lowlands and swamps, may hold the key to a cure for amoebiasis, a disease caused by the parasite Entamoeba histolytica that mostly hits the poor. A team of researchers from Jadavpur University and Indian Institute of Chemical Biology, both in Kolkata, have isolated a compound from the root of this plant that stops the growth of the parasite.
Among the seven compounds isolated from the root extract of the shrub (Pluchea indica) is r/j/3.
“This pure compound, chemically a thiophene derivative, was most effective in checking the proliferation of the parasites,” says lead researcher Tapan Kumar Chatterjee.
This could be a potent anti-amoebic drug, he says. The findings of the study will be published in a forthcoming issue of Phytomedicine.
The researchers took a virulent strain (hm1) of E histolytica and cultured trophozoites, the stage in which the parasite resides in the intestine and causes symptoms of amoebiasis. Then they exposed the trophozoites to varying doses of the pure compound.
r/j/3 showed optimum result at a dose of 0.00005 gm per ml. Two hours after administration, it caused granulation in the trophozoites. In four hours, the trophozoites were completely broken down. r/j/3 acted slower than synthetic drugs like metronidazole. “But being a plant product, it is safe and non-toxic. Metronidazole is very toxic and parasites are sometimes resistant to it,” Chatterjee says.
The above article was originally published in Down To Earth, a science and environment fortnightly published from New Delhi and written by this blogger.
Saturday, June 30, 2007
Aloe vera could cure Kala-azar
known for its cosmetic applications, aloe vera, the wonder plant, has now been found to possess ingredients that can cure kala-azar and some other forms of leishmaniasis. Ghrita Kumari, as the plant is locally known, can kill two forms of leishmania parasites, researchers from Kolkata’s Institute of Post Graduate Medical Education and Research and Indian Institute of Chemical Biology have found. Leishmaniasis is a disease caused by protozoan parasites that belong to the genus Leishmania and is transmitted by certain species of sand fly.
In laboratory experiments, the team found that leaf extracts of the aloe vera plant directly killed two kinds of parasites, promastigotes and amastigotes. The promastigote form enters the human body through sand-fly bites and morphs into amastigote inside the macrophage cells, a type of immune cells derived from while blood cells.
This causes kala-azar or leishmaniasis with symptoms like fever, loss of appetite and enlarged spleen and liver.
“Aloe vera extracts activated cultured mice macrophages increasing the production of toxic metabolites of oxygen like superoxide anions, hydrogen peroxide and nitric oxide,” says Mitali Chatterjee, lead co-author of the study. “I feel that these toxic metabolites help generate oxidative stress-destroying leishmania parasites inside the macrophages,” she says. According to her, the study has immense potential as aloe vera is easily available and its toxicity is low. Aloe vera, she says, could be a potential herbal remedy for kala-azar and other types of leishmaniasis.
To study the efficacy of aloe vera extract, five parasitic strains including k27 and jish 118 were isolated from patients with cutaneous leishmaniasis, lv81 and l280, from patients with mucocutaneous leishmaniasis while mon 29 and 2001 were isolated from patients with visceral leishmaniasis.
After culling promastigotes from patients, the team converted them into amastigotes in culture media outside macrophage cells. Then promastigotes and amastigotes were exposed to various concentrations of the plant leaf extract. “The extract possesses a direct parasiticidal effect on leishmania promastigotes, irrespective of the species, suggesting its efficacy in all forms of leishmaniasis,” comments Chitra Mandal, one of the authors.
The potency of the extract to kill leishmania amastigotes was over 25-fold higher than in promastigotes, write the researchers in Glycoconjugate Journal (Vol 24, No 1). This was significant, considering amastigotes are responsible for the disease.
According to the researchers, the study is significant as available anti-lesihmanial therapy has drawbacks like toxic side-effects, high cost and drug-resistance. Aloe vera could be an effective antidote to kala-azar, which according to the National Vector Borne Disease Control Programme, puts 165.4 million people at risk in Bihar, Jharkhand, Uttar Pradesh and West Bengal.
The above article was originally published in the 30 April 2007 issue of Down To Earth, a science and environment fortnightly published in New Delhi and written by this blogger.
known for its cosmetic applications, aloe vera, the wonder plant, has now been found to possess ingredients that can cure kala-azar and some other forms of leishmaniasis. Ghrita Kumari, as the plant is locally known, can kill two forms of leishmania parasites, researchers from Kolkata’s Institute of Post Graduate Medical Education and Research and Indian Institute of Chemical Biology have found. Leishmaniasis is a disease caused by protozoan parasites that belong to the genus Leishmania and is transmitted by certain species of sand fly.
In laboratory experiments, the team found that leaf extracts of the aloe vera plant directly killed two kinds of parasites, promastigotes and amastigotes. The promastigote form enters the human body through sand-fly bites and morphs into amastigote inside the macrophage cells, a type of immune cells derived from while blood cells.
This causes kala-azar or leishmaniasis with symptoms like fever, loss of appetite and enlarged spleen and liver.
“Aloe vera extracts activated cultured mice macrophages increasing the production of toxic metabolites of oxygen like superoxide anions, hydrogen peroxide and nitric oxide,” says Mitali Chatterjee, lead co-author of the study. “I feel that these toxic metabolites help generate oxidative stress-destroying leishmania parasites inside the macrophages,” she says. According to her, the study has immense potential as aloe vera is easily available and its toxicity is low. Aloe vera, she says, could be a potential herbal remedy for kala-azar and other types of leishmaniasis.
To study the efficacy of aloe vera extract, five parasitic strains including k27 and jish 118 were isolated from patients with cutaneous leishmaniasis, lv81 and l280, from patients with mucocutaneous leishmaniasis while mon 29 and 2001 were isolated from patients with visceral leishmaniasis.
After culling promastigotes from patients, the team converted them into amastigotes in culture media outside macrophage cells. Then promastigotes and amastigotes were exposed to various concentrations of the plant leaf extract. “The extract possesses a direct parasiticidal effect on leishmania promastigotes, irrespective of the species, suggesting its efficacy in all forms of leishmaniasis,” comments Chitra Mandal, one of the authors.
The potency of the extract to kill leishmania amastigotes was over 25-fold higher than in promastigotes, write the researchers in Glycoconjugate Journal (Vol 24, No 1). This was significant, considering amastigotes are responsible for the disease.
According to the researchers, the study is significant as available anti-lesihmanial therapy has drawbacks like toxic side-effects, high cost and drug-resistance. Aloe vera could be an effective antidote to kala-azar, which according to the National Vector Borne Disease Control Programme, puts 165.4 million people at risk in Bihar, Jharkhand, Uttar Pradesh and West Bengal.
The above article was originally published in the 30 April 2007 issue of Down To Earth, a science and environment fortnightly published in New Delhi and written by this blogger.
Friday, June 29, 2007
Scorpion Venom Antidote to Blood Cancer
venom spewed by the deadly Indian black scorpion (Heterometrus bengalensis) could have a possible cure for human blood cancer, a new research claims.A joint team from Indian Institute of Chemical Biology, Kolkata, and University of Calcutta found in laboratory tests that venom from the black scorpion stopped the proliferation of cultured human blood cancer cells and drove them to commit mass suicide (apoptosis or programmed cell death).
“This is the first report of anti-cancer potential of Indian black scorpion venom from India,” says Aparna Gomes, who led the research. “We have already identified that the anti-cancer effects of scorpion venom are due to the presence of certain proteins,” says Antony Gomes, co-author of the study to be published in a forthcoming issue of Leukemia Research.
The researchers are working to decipher the identity of the anti-cancer proteins in scorpion venom and find how those proteins inhibit the growth of cancer cells. This provides clues to the development of a new anti-cancer drug.
The researchers cultured two types of human leukaemic cell lines (u937 and k562) and exposed them to doses of scorpion venom for 48 hours. The team took two million of each type of leukaemic cells. The u937 cells were exposed to 0.0000415 gram/ml of scorpion venom and k562 cells to 0.0000883 gram/ml. A batch of unexposed leukaemic cells was treated as controls. The study found that both the doses of venom halted the growth of 50 per cent of the cancer cells. Sophisticated imaging techniques revealed that the venom-treated cancer cells underwent controlled death.
The control cancer cells showed intact cell membrane, but the treated cells clearly showed deep ridges and furrows as well as severe membrane bulging, the hallmark of mass death. The treated cells had damaged nuclei as well as fragmented dna compared to intact ones of controls. The venom also arrested the cell cycle reducing the dna content of the cancer cells.
Such study results are encouraging. “Of the 90 species of venomous Indian scorpions, we have seen only one species,” says Antony Gomes. He believes that more effective anti-cancer drugs can be made by studying venoms.
A cheap anti-leukaemic drug is urgently needed as the National Cancer Registry has identified leukemia among ten of the leading cancers in Delhi, Aurangabad, Barshi, Bangalore, Nagpur and Thiruvananthapuram.
The above article was originally published in 'Down To Earth', a science and environmently fortnightly and written by this blogger
venom spewed by the deadly Indian black scorpion (Heterometrus bengalensis) could have a possible cure for human blood cancer, a new research claims.A joint team from Indian Institute of Chemical Biology, Kolkata, and University of Calcutta found in laboratory tests that venom from the black scorpion stopped the proliferation of cultured human blood cancer cells and drove them to commit mass suicide (apoptosis or programmed cell death).
“This is the first report of anti-cancer potential of Indian black scorpion venom from India,” says Aparna Gomes, who led the research. “We have already identified that the anti-cancer effects of scorpion venom are due to the presence of certain proteins,” says Antony Gomes, co-author of the study to be published in a forthcoming issue of Leukemia Research.
The researchers are working to decipher the identity of the anti-cancer proteins in scorpion venom and find how those proteins inhibit the growth of cancer cells. This provides clues to the development of a new anti-cancer drug.
The researchers cultured two types of human leukaemic cell lines (u937 and k562) and exposed them to doses of scorpion venom for 48 hours. The team took two million of each type of leukaemic cells. The u937 cells were exposed to 0.0000415 gram/ml of scorpion venom and k562 cells to 0.0000883 gram/ml. A batch of unexposed leukaemic cells was treated as controls. The study found that both the doses of venom halted the growth of 50 per cent of the cancer cells. Sophisticated imaging techniques revealed that the venom-treated cancer cells underwent controlled death.
The control cancer cells showed intact cell membrane, but the treated cells clearly showed deep ridges and furrows as well as severe membrane bulging, the hallmark of mass death. The treated cells had damaged nuclei as well as fragmented dna compared to intact ones of controls. The venom also arrested the cell cycle reducing the dna content of the cancer cells.
Such study results are encouraging. “Of the 90 species of venomous Indian scorpions, we have seen only one species,” says Antony Gomes. He believes that more effective anti-cancer drugs can be made by studying venoms.
A cheap anti-leukaemic drug is urgently needed as the National Cancer Registry has identified leukemia among ten of the leading cancers in Delhi, Aurangabad, Barshi, Bangalore, Nagpur and Thiruvananthapuram.
The above article was originally published in 'Down To Earth', a science and environmently fortnightly and written by this blogger
Wednesday, February 28, 2007
Nanoparticles Could Help in Screening Individuals for Thalassaemia
A type of nanoparticles could provide clues to whether a person carries the defective gene for thalassaemia, claims a research team from Kolkata-based Calcutta University. Known as copper nanoparticles (CuNPs), the nanomolecules form various protein aggregates binding to haemoglobin, the metalloprotein in red blood cells. Besides protein aggregrates, the copper nanoparticles also precipitate the aggregated protein.
The researchers found that the nanoparticles formed a distinct aggregation when bound to a mutated form of haemoglobin that leads to beta-thalassaemia. Using special techniques like atomic absorption spectroscopy and high-pressure liquid chromatography, the team found the nanoparticles were co-precipitated with specific variants of haemoglobin. Studies showed that protein initially broke the nanoclusters into smaller sizes (4nm), followed by gradual increase in cluster size. A suitable scaling up of the approach may have important implications in screening haemoglobinopathies such beta-thalassaemia, write the researchers in a recent issue of Nanomedicine.
According to an estimate, there would be about 45 million carriers and about 15,000 infants born each year with haemoglobinopathies in India. The carrier frequency of haemoglobinopathy varies from 3 to 17 per cent in different population groups of India. In India, beta-thalassaemia comprises about 80–90 per cent of the total thalassaemias reported. More than 200 beta-thalassaemia mutations have been identified all over the world and of these about 28 mutations have been documented in Indian patients. There is growing concern that thalassemia may become a very serious problem in the next 50 years.
A type of nanoparticles could provide clues to whether a person carries the defective gene for thalassaemia, claims a research team from Kolkata-based Calcutta University. Known as copper nanoparticles (CuNPs), the nanomolecules form various protein aggregates binding to haemoglobin, the metalloprotein in red blood cells. Besides protein aggregrates, the copper nanoparticles also precipitate the aggregated protein.
The researchers found that the nanoparticles formed a distinct aggregation when bound to a mutated form of haemoglobin that leads to beta-thalassaemia. Using special techniques like atomic absorption spectroscopy and high-pressure liquid chromatography, the team found the nanoparticles were co-precipitated with specific variants of haemoglobin. Studies showed that protein initially broke the nanoclusters into smaller sizes (4nm), followed by gradual increase in cluster size. A suitable scaling up of the approach may have important implications in screening haemoglobinopathies such beta-thalassaemia, write the researchers in a recent issue of Nanomedicine.
According to an estimate, there would be about 45 million carriers and about 15,000 infants born each year with haemoglobinopathies in India. The carrier frequency of haemoglobinopathy varies from 3 to 17 per cent in different population groups of India. In India, beta-thalassaemia comprises about 80–90 per cent of the total thalassaemias reported. More than 200 beta-thalassaemia mutations have been identified all over the world and of these about 28 mutations have been documented in Indian patients. There is growing concern that thalassemia may become a very serious problem in the next 50 years.
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