Despite much research, cancer remains incurable in most cases. However, a team of scientists at the Scripps Research Institute in California believe antibiotics could form the basis of a new approach to treating tumors. They studied two fused proteins that are part of the tumour-creation process, and discovered a way of attaching substances to the killer DNA, effectively stopping it from reproducing. Although research continues, the most likely candidate look to be the aminoglycoside group of antibiotics, which could be used to create a new breed of cancer-killing medication.
Broken bones that refuse to heal could soon be set straight with a new drug that stimulates the growth of blood vessels. The University of California in San Francisco has begun testing the technique on mice, and believes that human trials could start within a year.
Known as VEGF, the drug used in the study is also being tested as a way of helping patients with blocked arteries grow replacements. However, the team discovered that many of the nutrients needed to heal bones were also increased by the drug. Testers took 20 mice with broken bone and moved the splints holding the bone in place every day. In ordinary mice this stopped any healing, but mice injected with VEGF began to heal after 10 days.
SCIENTIST ENVISION ANTI-AIDS CREAMS
The first laboratory model of the female genital tract to shed light on how women become HIV-infected during sex is fuelling hopes that new prophylactic creams can be developed to prevent the spread of Aids, researchers said.
Scientists at the University of Pittsburgh and Northwestern University have already shown that only a small amount of the anti-Aids drug, PMPA, completely blocks HIV transmission when applied to human cervical tissue.
With a grant from the national institutes of health, researchers are about to begin tests on three other unidentified drugs which they hope will prove equally effective. “A model such as this is long overdue in understanding the virologic and host factors involved in HIV transmission in women,” said University of Pittsburgh microbiology professor Phalguni Gupta yesterday.
“The main route of HIV transmission has always been sexual, and heterosexuals are quickly becoming the target HIV-positive population, particularly in third-world countries.”
The new model, detailed in the journal Nature medicine, uses tissues provided by otherwise healthy women who undergo reproductive surgical repair. Earlier Aids-transmission models have relied on only a single layer of cells, Gupta said. But the new model provides the natural tissue architecture of the female genitaltract including epithelial cells, submucosa and immune cells.
Researchers place non-cellular HIV on top of a thumbnail-size piece of squamous cervical tissue and look to see how much of the virus penetrates to the bottom.
Gupta plans to develop a model using rectal tissue that can be used to study HIV transmission between homosexual men, Such models also can be used to study different strains of HIV as well as other sexually transmitted diseases. “This is the only system that tests not only the effectiveness but the toxicity of drugs people might think of using in creams or suppositories,” he said.
PMPA, an experimental reverse transcriptase inhibitor developed by California-based Gilead Science Inc., was found to block HIV transmission without signs of toxic reaction, Gupta said. Researchers believes the drug prevented the Aids virus from replicating. Scientists at Northwestern University were studying the results of the test to determine exactly how the drug worked.
ZERO IN ON SWEET TOOTH GENE
Gary Beauchamp. Director of the Monell Chemical senses Centre in Phildelphia, told a meeting of the American Chemical Society on Tuesday new research on mice had narrowed the hunt for a genetic sweet tooth to a strip of DNA. This area, located on mouse chromosome four, “is a likely candidate for a Sweet taste gene,” Beauchamo said. “It plays a prominent role in sweet perception in mice and, most likely, in humans.”
The Monell research narrowed the field to some 100 of the approximately 10,00 genes which make up the chromosome. Discovery of which is the actual “sweet tooth” gene could come by the end of the year, he said. This gene, Beauchamp said, “Affects not only liking for sweetness but also affects the physiological response of the taste nerve to sweetness.”
Isolating and understanding the sweet tooth gene could help enhance understanding of how taste receptors interact with the body’s other systems, Beauchamp said. It also could help to explain taste differences, such as why some people prefer milk chocolate while others prefer the bittersweet variety, eventually paving the way for “tailor-made” sweets designed to appeal to very specific sets of taste buds. “We believe the gene somehow controls variations in sweet perception.,” Beauchamp said.
SOME CHILDREN DON’T EAT CAKE!
NO TO GLUTEN
Wheat intolerance means that you can’t have foods that contain gluten and certain milk products. For example, you can’t have things like: biscuits, cakes, pasta, pizzas, suji, ice-creams, processed tinned foods, non-dairy creamers, yoghurt, hot chocolate, canned soups, salad dressings, cheese spread, tomato sauce and peanut butter.
This means that you can’t even think about an occasional intake of gluten containing foods. Treatment for celiac disease is a diet containing “No GLUTEN’.
Since it is a life-long affliction, the treatment for celiac too goes on for life.
Remember, it is better to be ultra-sensitive to even an unintentional Ingestion of gluten.
Therefore, always read the labels of commercial foods and raw materials before purchase.
Always be careful while eating out. Which also means informing your party host in advance about your/child’s wheat intolerance.
Don’t forget to supplement your diet with adequate nutrients under medical supervision.
What is Wheat allergy?
Celiac disease is a condition caused by a permanent intolerance to gluten, Gluten is a protein present in wheat, barley, rye, oats. In some people gluten reacts adversely with the intestinal lining, thus reducing its ability to absorb food or more precisely nutients. Wheat therefore is poison for patients suffering from celiac.
Typical symptoms of celiac are chronic diarrhea, vomiting, listlessness, recurrent abdominal pain, malnutrition, stunted growth irritability, anemia and weight loss. It’s a disease that manifests itself in children (cases range from 18 months to 12 years) and while a drastic diet therapy cures the attendant problems the allergy is a life long ailment.
“If a child shows symptoms like these, the first and most important thing to do is to see a specialist and get them diagnosed. An endoscopy and a biopsy is a must as that is what determines the diagnosis. It is dangerous to stop wheat and its by-products on your own. Self medication is also a big nono.”
Celiac is not a major problem at the moment. There is o need to be alarmed just a need to be careful and conscious. The problem is completely treatable and one needn’t lose hope. Of course, a strict diet is necessary and that may seem like a monumental task while dealing with kids.
Compliance is important to prevent complications. An increased appetite, decreased malabsorption, increase in height and weight and improved sense of wellbeing are the signs of good compliance,” adds Agarwala.
As an alternative to wheat diets, nutritionists and doctors advise a diet dominated by rice, arrowroot, potato, soybean, dal, sago, tapioca, maize, cornflower, besan and buckwheat flour. Fresh fruits, juices, salads, fresh vegetables, idlis, dosas, roasted corn are some of the other food items that can make a menu interesting. Doctors also advise against an occasional intake of glutenous food as it may cause relapse.
Hospitals like Apollo Indraprastha, Kalawati Saran, AIIMS and Maulana Azad Medical College offer facilities for diagnosing celiac in Delhi.
WHICH WAY OUT? MEN AND WOMEN HAVE DIFFERENT ANSWERS
Chalk one up for the Y chromosome: According to a new study, men who get lost can often find their way out of unfamiliar places better than women.
The findings add a biological counterpart to prior research that indicated men and women tend to use different strategies to navigate. The new work suggest they use different parts of their brains, too. Researchers scanned the brains of 12 men and 12 women as they tried to escape a three-dimensional virtual-reality maze. The volunteers pushed buttons to move their virtual selves left, right or ahead.
In the real world, that might be like trying to find a specific place in an unfamiliar city, said neurologist Dr. Matthias Riepe of the University of Ulm in Germany. The mengot ut of the maze in an average of two minutes and 22 seconds, vs. an average of three minutes and 16 seconds for the women. That fits with previous studies in animals and people that suggest males navigate better in an unfamiliar environment. The brain scans found that while both sexes used some of the same parts of the brain for the task, there were also some differences. Riepe and colleagues describe the results in the April issue of the journal Nature Neuroscience.
One difference involved the hippocampus, a banana-shaped structure deep in the brain that is crucial for navigation. People have a hippocampus in each side of the brain. Riepe’s study found that both sexes used the right hippocampus in negotiating the maze. But only men used the left hippocampus. Conversely, women used an outer part of the brain called the right prefrontal cortex, while men in the study didn’t. That might reflect differences in how men and women handle information about the space around them. Riepe and colleagues said. Prior work suggests that women rely mostly on landmarks to navigate (“Turn right at the drugstore, then left at the grocery”) while men lean toward using geometry, as one would figure from a map (“The museum should be over that way”). The women’s activity in the cortex reflect the effort of keeping landmark cues in mind, while the hippocampus activity in the men might be needed for the geometric approach, the researchers said.
Riepe said his study could not explore whether the brain differences are larned or biologically programmed. But he said he suspects the latter, because they also appear in rats. Diane Halpern, a psychologist at California State University in San Bernardino and an experton gender differences in thinking, noted that sex differences in brain activity have been observed for other tasks, such as reading.
So it’s not surprising to find another example, she said. Such differences probably result from both experience and programmed influences, because the brain changes in response to experience, said Halpern stressing that women generally outperform men in some mental tasks - such as creating of a list of words that begin with a given letter - so one can’t say that menare generally smartern than women. Riepe said his study couldn’t explain the popular notice that men are more reluctant than women to ask for directions when lost. “That’s a different story, I think, “ he said.
DOCTORS ADVISE AGAINST VITAMIN C WITH CANCER THERAPY
Taking high doses of Vitamin C while undergoing traditional cancer therapy may interfere with radiation or chemotherapy treatments and, in a perverse way, possible protect the very cancer cells that treatments are designed to destroy, doctors said yesterday.
Vitamin C, also called ascorbic acid, has long been taken by both healthy people and those who are ill in hopes that its antioxidant properties will work to destroy harmful substances in the body known as free radicals. The common oxidation process that results in these free radicals may play a part in causing cancer. Supplemental tablets containing Vitamin C is just one of many types of alternative and complementary therapies that cancer patients turn to, either out of desperation simply in a desire to feel better.
A high dosage of Vitamin C would be roughly 1,000 milligrams a day, researchers said.
Dr. David Golde, physician-in chief at memorial Sloan-Kettering Cancer Centre in New York, said it is not unreasonable for healthy people to supplement their diets with Vitamin C, they should be aware that most tumours are known to posses a high concentration of the chemical already.
“we don’t know what the cancer cell is doing with the Vitamin C,” Golde said. “ My experience as a biologist would suggest that it’s no accident. “ The use of Vitamin C as an alternative therapy has been coming back into vogue after a hiatus following a study by Mayo Clinic researchers that showed it had no benefit, said Barrie Cassileth, head of the Integrative Medicine Service at Memorial Sloan-Kettering.
Cassileth and Golde were speaking at an annual seminar here sponsored by the American Cancer Society. Their latest research showed cancer cells transport a version of Vitamin C called dehydroascorbic acid through cellular channels normally used to admit the energy source glucose. Cancer cells are also known have many more glucose transport channels than normal cells. “Overall, we need to think about the nutritional needs of tumour cells, as well as those of normal cells, in formulating answers to patient questions regarding taking supplemental Vitamins C,” he said.
While prudent advice for cancer patients is to have very good eating habits, Cassileth said alternative therapies that have not been adequately studied may in fact be harmful. She said patients may inadvertently interfere with their treatment, with anaesthetic agents and even trigger cardiac arrest. “That’s the last thing we want to happen in oncology,” she said.
PHYTASE IN FEED CAN BOOST PRODUCTION IN POULTRY
Enzymes can play an important role in poultry nutrition or feeding. Phytase is one among them. It acts on phytates present in feed stuffs. Phytate is present mainly in cell walls in association with pectate. It is an inositol-phosphoric acid, occurring as calcium and magnesium salt. It is considered an anti-nutrient. It is said to reduce protein digestion with the formation of phytate-protein complexes. It decreases the availability of certain minerals like phosphorus, zinc, magnesium and iron. In these phosphorus is very important. Along with pectate, phytate hinder the entry of digestive enzymes into the cells.
The enzyme phytase hydrolyses or destroys phytate of the cell walls. Hence, digestive enzymes enter freely into the cells, resulting in improved cellular digestion. Added to it, cell walls are also digested and their nutrients are available in the gastro-intestinal tract for poultry.
These include, some proteins, fats and other minerals, mostly phosphorus and calcium. Moreover, phytase is said to reduce phosphorus excretion from the gut, leading to its conservation.
Phytase is formed in seeds, when they sprout or germinate and it is helpful to the young growing plants to have more nutrients from the seeds. Phytase is also present in appreciable amounts in the young growing parts of plants and its concentration slowly gets reduced as the parts mature.
It is also present in growing media of microorganisms including fungi. A few feed stuffs like wheat bran also contain a little in them. Thus, phytase in the gastro-intestinal tract originates from plant feed sources, the growing gut microflora and to a little extent endogenous production by the intestinal mucosa.
Feeding experiments indicated that, phytase is effective in improving the nutrient utility and mineral availability of feed stuffs, particularly phosphorus. This resulted in increased feed conversion rate, leading to enhanced growth rate and performance.
Phytase is relatively stable at higher temperatures of feed processing to some extent. It is also economical to produce it, as compared to many other enzymes, such as cellulase and lignase. Thus, to improve the nutritive value of feed stuffs and to minimise wasteage phytase is used in poulty feeds. At present, enzyme supplemented poultry feed are more common in western countries.
Current capabilities worldwide seem set to invade our planetary neighbor in the coming two decades. A number of missions are planned by several countries to send either orbiting or landing spacecraft to Mars. Mars has always intrigued the planet watcher more than any other object in the sky. Its reddish angry hue led to its christening as a war god. No less fascinating is its to know that the hue arises from the presence of rust in considerable quantities among the rubble lying on its surface, a rubble which turns out to be highly magnetic!
Many intricate channels visible on its surface lead one to suppose that water in a liquid form must have once flowed. Evidence exists for events of catastrophic flooding in the past. Currently, of course, no liquid water exists on Mars. However, frozen water is present in the polar caps of the planet and as water of hydration in the soil minerals and perhaps, as a permanent frost in the sub-surface layer.
We know water exists on Mars in small quantities. We also know that much larger quantities must have flowed on the surface in the past. We do not know what processes might have heated the planet in the past, if at all, and kept it in a wet and warm condition. It seems the most pressing questions which need to be answered regarding Mars, is not so much about its present as its past. Was it wet and warm in an earlier epoch? Did such epochs happen periodically? Were the conditions on the surface and the atmosphere at that time such as to have supported life of some kind?
One of the missions planned in the immediate future is the Mars Surveyor 2001 scheduled to be launched by NASA on April 10, 2001. It will land on Mars on January 22, 2002. However, many Mars missions have failed in the recent past.
Whenever this missions scheduled and launched, on arrival at Mars year later, it can only propel our digging up of Martian history throught a gaint leap. Mission planners will choose the landing site close to the Martian equator after looking at high resolution images of the surface, which will provided by an orbiter accompanying the landing instrument. The planners have to take into account whether the landing sit might be too rocky, too steep or be a region with too much dust flying around. An engineer would select the safest possible site, while a scientist where the most interesting scientific experiments might be performed!
The instruments on board this mission are the Marie Curie Rover instruments, which include a camera and an Alpha Proton X-ray Spectrometer (APXS), and a robotic arm of the rover meant to scoop up Martian soil and rock samples for experiments. The APXS can determine which elements are found in rocks and soils beyond the reach of the Lander’s robotic arm. It will be used to analyse the chemistry of soils that stick to a magnet mounted on one of the Lander’s legs.
The APXS will bombard its target with alpha particles (helium nuclei), and examine any reflected alpha particles, protons or X-rays scattered from the target. Since each chemical element present in the sample will scatter these particles in different ways, this will give such an instrument a handle in finding out the chemical content of Martian soils. In addition, the mission is equipped with other technology experiments crucial for future human missions to Mars. For example, existence of fine dust in the Martian atmosphere might clog astronaut equipment. One would also need to know the radiation risk for human explorers.
“Two worlds, one Sun” will be inscribed on the sundial that will be set up on the Martian surface by the robotic instruments. The Lander’s panaromic camera (pancam) can image the sundial and the shadow cast on it by the Sun. We can be aware of the time at this site on Mars, whenever we wish to know its!
The final sundial design was arrived at after sifting through many student suggestions. The sundial will include inscriptions in 24 languages, representing three-quarters of the earth’s people.
are only some of the instruments and some of the experiments that
can be performed by robotic instruments on board any such mission
to Mars. There is a lot we would like to know about this planet
and we have only started digging as yet!
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