Health Meaning

SAN DIEGO - When you hear of insulin, you probably think of diabetes, but perhaps it could soon bring to mind the disease Alzheimer. The connection is an enzyme that breaks insulin and a protein that causes Alzheimer's disease. Now, a preliminary study suggests that dysfunction of this enzyme may be responsible for Alzheimer's disease in some families.

Alzheimer patients suffer from excessive amounts of a protein called b amyloid, which for some reason built into their brain. In some cases, it appears that genetic mutations increase the production of b amyloid. Alternatively enzymes - so far unknown - which break b amyloid simply do not work fast enough. In 1994, researchers found the first candidate: Insulin-degrading enzyme (IDE) breaks down b amyloid in a test tube. FDI but does not seem likely to be clinically important, because it is normally found in the cytoplasm, and b amyloid built between the inner closed cells or vesicles in the cell.

New evidence for the importance of FDI came from Dennis Selkoe, Wesley Farris and colleagues from Harvard Medical School in Boston. Although screening of brain cells to proteins that destroy b amyloid, they discovered that FDI seemed to have more naturally secreted b amyloid. At the annual meeting of the Society for Neuroscience here Farris November 11 reported that blocking FDI activity stopped approximately 70% of b amyloid ventilation in isolated cell membranes from brain tissue. And causing cells to overproduce FDI intensified the rate of b amyloid ventilation.

The team also worked with the geneticist Rudolf Tanzi and his colleagues from Massachusetts General Hospital to see whether mutations in the gene for FDI could contribute to Alzheimer's disease in people with a family history of disease. The Tanzi group provided data on the seven families of Alzheimer's disease appears to be related to the region of chromosome 10 that contains idea. Selkoe's team analyzed the cells of these families and found that members of the same family had significantly fewer b amyloid degradation than normal, suggesting that FDI can contribute to broken disease. The team is looking for more families with Alzheimer's disease that can have such mutations.

The data are "very encouraging," says Alzheimer's researcher Frank Laferla of the University of California, Irvine, but he remains convinced that IDE cleans most of b amyloid . "It will not be a single enzyme that degrades b amyloid," he said.

Related Sites

Summary of the Society for Neuroscience meeting
learn more about Alzheimer's disease from the National Institute on Aging

Scientists have modified a common respiratory viruses to destroy cancer cells while leaving healthy unharmed, said a report in tomorrow's issue of Science . The next step - a clinical trial in human cancer patients - is already underway

The cancer killer pathogen is genetically modified lung and a family member of adenovirus .. Biochemist Frank McCormick and ONYX Pharmaceuticals colleagues in Richmond, California, found that the modified virus is unable to replicate in normal cells, but it develops into cancer cells lacking the gene p53 that suppresses tumor growth. The p53 gene, leaving cells vulnerable to the virus when it is out, is one whose loss or inactivation is linked to the development of 50% of human cancers. Consequently, the virus could be widely applicable in the treatment of cancer, particularly because the loss of p53 also allows to make cancers resistant to conventional chemotherapeutic drugs. The modified virus has killed human tumors implanted in mice while sparing normal cells.

`` What I like is how smart he is, '' said Richard Klausner, director of the National Cancer Institute. `` It has been a longstanding fantasy to find a [anti-cancer] virus. '' However, he warned that `` not all [new cancer treatment] who is intelligent and focused [to tumor cells] will end up being useful. ''

ONYX team tests the safety of the virus in people with cancer of the head or neck that do not respond to conventional therapies. The tests should be completed in 1997. To date, the virus, which is injected directly into the tumors of patients appears to be safe. But it is too early to say whether the virus has the same ability to kill tumors in humans it has in mice.

WASHINGTON, DC - A deadlock that has gripped the longest and most expensive war in modern times - war against cancer - can finally eased. The cancer death rate in the US fell by 2.6% between 1991 and 1995, the National Cancer Institute (NCI) announced today, marking the first sustained decline 6 decades of modern cancer cases.

"This looks like a turning point in the war 25 years on cancer," Donna Shalala, Secretary of Health and Human Services, said in a statement today. "It is not just a blip once, but a trend of real and promising fall." After a 6.4% increase in mortality from cancer between 1971 and 190, the decline suggests that lifestyle changes and improved treatments start paying.

For example, lung cancer mortality among men dropped 6.7%, representing more than half of the overall decline of 4.3% of cancer deaths in men. NCI attributes this decline in part to the 15% decrease between 1955 and 1970, the percentage of men who smoke. For women, however, lung cancer deaths increased, apparently because smoking among women increased in the 1960s increasing numbers of lung cancer offset strong gains against breast cancer because of diagnostic earlier and better treatment, keeping the overall decline in women's cancer mortality to only 1.1%.

African Americans seemed to make the biggest gains. They experienced an overall decline of 5.6% of cancer mortality, compared with an increase of 18.3% between 1971 and 190.

definitive cancer rates for 1995 will not be released before next year, but experts predict the downward trend will remain relatively unchanged. Says the NCI Director Richard Klausner, "The 190s will be remembered as the decade when we turned measurably tide against cancer."

LONDON - claims in the British media this week that the government is ready to give fire green transplantation of organs from genetically modified pigs in human patients were dismissed as "pure speculation" by a Ministry of Health official. The official said a decision will be announced in 1997.

The London Times and the BBC reported yesterday that the government had accepted the recommendation of an inquiry it was safe to advancing transplants. They reported that the inquiry, chaired by Ian Kennedy, professor of medical law and ethics at the College, London King raised the issue that pig organs could spread to humans potentially dangerous animal viruses. Nevertheless, the Committee has concluded that neither the security nor the ethical issues blocking the way for pig to human transplants. Transgenic pigs are a regulatory protein that helps prevent the immune system from attacking a transplanted organ.

A Ministry of Health official has neither confirmed nor denied that the government planned to approve pigs to humans. "The report will be published in the new year, and we will have to wait until then," he said. A spokesman Imutran, the company based in Cambridge UK, which developed transgenic pigs, says the company n has no information on the content of the report. "speculation is new for us," she said.

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a laboratory of tests indicated that a chemical found in grapes and other fruits and vegetables is a potential antitumor agent. But experts warn that the compound, described in a report in tomorrow's issue of Science , is at least 2 years of testing in humans, and early results do not justify more trips the wine rack.

medicinal chemist John Pezzuto and colleagues at the University of Illinois, Chicago, did not expect it to improve the image of red wine when they began their study. His team was one of many who just a few years began testing some 1,000 plant extracts from around the world for the presence of potential antitumor agents. Their main assay revealed that extracts which inhibit an enzyme called cyclo-oxygenase-1, a cog in the body's inflammatory response. Pezzuto says, "anti-inflammatory agents tend to be good antitumor compounds."

> The team narrowed the 1000 extracts down to three that seemed particularly promising. The most powerful came from Peru roots of Cassia quinquangulata tree, extracts of which are used in traditional medicine to treat fever. Further experiments on a hosted component of the extract called resveratrol, a compound produced in some plants when they are subjected to a stress or pathogen attack. The compound did well in the anti-tumor tests. In addition to inhibition of cyclooxygenase, it impeded the DNA mutations in Salmonella bacteria, increasing the activity of an enzyme in the liver of mice that detoxifies carcinogens, precancerous lesions inhibited in mouse mammary cells, and growth upset of skin tumors in mice exposed to a powerful skin. carcinogenic

Resveratrol is particularly useful as anti-cancer drug candidate because it is easy to obtain: The chemical is abundant in grape skin and has been found in at least 70 other species of plants, including peanuts and mulberries. But experts warn that the compound has a long way to go before the beginning of the pharmacy. "This is a good lead, but it is very early," says Peter Greenwald, director of the division Prevention and fight against cancer from the National Cancer Institute. Greenwald adds that resveratrol is facing at least 2 years' other animal testing and safety testing before it is considered a human cancer prevention trial: "We are certainly far from saying" drink lots of red wine "

A vaccine against cholera cheap performed well in a pilot in Vietnam. The discovery, published in the tomorrow The Lancet , is a breakthrough in the search long and frustrating in developing countries an effective vaccine against cholera, a potentially fatal disease spread by contaminated drinking water.

at the end of 1992, a team led by researchers at the National Institute of Hygiene and Epidemiology in Hanoi, Vietnam, and the National Institute of Child Health and Human Development United States has given the oral vaccine - which is to kill all Vibrio cholerae , the cholera bacteria - to more than 67,000 residents of Hue, Vietnam. A number approximately equal did not receive the vaccine. In 1993, 37 people were vaccinated admitted to a hospital with cholera, against 92 cases in the control group. Thus, the vaccine decreased hospital admissions for cholera by 60%.

Developed and produced at the institute in Hanoi, the vaccine is relatively cheap to produce and easy to distribute as it remains active without refrigeration. He also seems to be equally effective in children and adults. What surprised the researchers, because a similar set, tested vaccine killed in Bangladesh in the 1980s seems to be less strong in children.

"This study is important," said Myron M. Levine, director of the Center for Vaccine Development at the University of Maryland School of Medicine, "because it demonstrates that a developing country can design, produce and evaluate a moderately effective vaccine in a large field trial with little outside help. "

researchers plan to launch a larger trial in Vietnam later this year between the vaccine against placebo. If proven effective, the vaccine could be pressed into service quickly in Vietnam, where more than 3,000 people receive cholera every year. Levine adds that a similar vaccine against other strains of cholera could be produced in developing countries such as Zaire, where an outbreak has killed 12,000 people in the Rwandan refugee camps in July 1994.

Creating a new organism from a single cell was more science fiction than science. Not anymore. Scientists have cloned a sheep using a cell nucleus taken from the udder of an adult sheep, according to a report is expected later this week Nature . The breakthrough has generated a fierce reaction from ethicists and others who fear the prospect of human cloning.

embryologist Ian Wilmut and his colleagues at the Roslin Institute Scotland first increased udder cells in laboratory dishes, then put the nuclei of these cells into egg cells whose DNA had been removed . They found that in the bud, the genome transferred back to embryonic pattern of gene expression, prompting the egg to start dividing. The viable embryo was then placed into the uterus of the ewe that had produced the egg.

Wilmut team first used this technique a year ago, producing lambs with nuclei transplanted from very early embryos. In their latest work, the group reports how cells taken from sheep at any time in their life will do the job. In addition to the lamb of the breast tissue of a sheep 6 years, four children were produced with cores 9 day old embryos and three from the cells of the skin 26 days fetus.

Others have new bodies, mainly amphibians and mice using embryonic nuclei, but failed when they used adult cells. "We now have strong evidence that it is feasible," said researcher Colin Stewart embryo Centre for Research and Development Frederick Cancer National Cancer Institute in Frederick, Maryland.

We thought that in mature somatic cells, certain genes necessary for the development have been transformed permanently, even lost. Thus the success of the group was a "surprise," says Wilmut. "The mechanisms that regulate the expression of genes are more labile than we could have imagined." Finally, Wilmut said he hopes to use nuclear transplantation to create sheep or cattle with genes added to their specific genomes

Theoretically, people could also be cloned. Imagine how much someone would pay for a basketball team fielding five versions of Michael Jordan. Wilmut said Science Now that his group was opposed to human cloning ethically. "We do not know if it will work [in people]," he added. Activists, however, take measures to counteract this possibility. For example, the critic Jeremy Rifkin Biotechnology of the Foundation on Economic Trends announced yesterday his group, as well as some religious leaders and non-governmental organizations, "is determined to mount a global effort opposed human cloning and will seek legislation to ban this technology in every nation. "Several countries - including Germany and the United Kingdom. - Have the laws on the books banning human cloning, but the United States is not among them

People with too little dopamine in their brains develop the debilitating symptoms of Parkinson's disease. Now scientists have identified a molecule that helps the brain get just the right amount of this neurotransmitter. The discovery, published in today's issue of Science * raises the possibility enticing that increasing or restoring the activity of this molecule, called Nurr1, omitting nerve cells could relieve or prevent Parkinson's disease.

researchers already knew that a gene called Nurr1 is most active in brain cells that produce dopamine. To find out what the gene's protein fact, a team led by Thomas Perlmann of the Ludwig Institute for Cancer Research and Lars Olson of the Karolinska Institute, both in Stockholm, Sweden, has created a strain of mice lacking the Nurr1 gene. These mice failed to nurse and died one day after birth. The only physical difference that the group could detect between KO and normal animals of the same age was in the midbrain region, which contains neurons that degenerate in Parkinson's disease. The cells were poorly organized, suggesting that they had never specialized in dopamine-producing neurons.

The team confirmed this suspicion by testing the presence of proteins known to be produced by these particular neurons. Nurr1, tyrosine hydroxylase (an enzyme essential for the production of dopamine) and of other proteins were all absent. Other experiments have suggested that Nurr1 not only causes dopamine cells to form in the first place, but it also helps produce the right amounts of dopamine. "Finding [protein] that affects such a specific [section] brain is very exciting," said neurobiologist Ron McKay of the National Institute of Neurological Disorders and Stroke in Bethesda, Maryland. The results raise the tantalizing possibility that the increase or the restoration of Nurr1 activity in failing nerve cells can delay or prevent Parkinson's symptoms.

It may also help researchers track down the cause of the disease. Because Parkinson's disease does not seem to run in families, experts have long sought an external cause, such as a toxic environment. It may now be possible to narrow the search by looking at how the potential toxic substances affect Nurr1. And that could lead to treatment, says molecular biologist Orla Conneely Baylor College of Medicine in Houston, whose team discovered the origin Nurr1: "If we find [toxicants] that inhibit the activity of Nurr1, we can then be able to identify drugs that can counteract that. "

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The number and shape of moles on your skin can indicate your risk of malignant melanoma, the most dangerous type of skin cancer. The results, reported in tomorrow's issue of The Journal of the American Medical Association , suggest that doctors should regularly examine moles of patients during physical examinations.

Although researchers have long known that large, irregular shaped moles are most likely to go wrong, Margaret Tucker of the National Cancer Institute and colleagues at Harvard Medical School wanted to identify the relation between the size, number and type of mole and melanoma risk. They asked dermatologists in two research centers on the major skin cancer - the Melanoma Clinic at the University of California, San Francisco, and the pigmented lesion clinic of the Hospital of the University of Pennsylvania - take detailed notes on the characteristics of moles for patients and melanoma moles turned into

having collected data on 738 patients with melanoma and 1,030 melanoma patients, Tucker's team found that subjects with more than 100 small moles -. 2-5 millimeters in diameter - were twice as high a risk of melanoma as did people with fewer moles. In addition, having one mole with an irregular contour or a color marbled also doubled the risk. Patients with 10 or more moles irregular had 12 times the risk of cancer patients without these moles.

The results are not surprising, as other epidemiological studies have implicated the moles as a risk factor for melanoma, said Sewa Legha, a clinical oncologist at MD Anderson Cancer Center in Houston. However, he said, better quantify the risk is important because too few doctors understand the importance of regular skin examinations. "Doctors are not well versed in recognizing abnormal moles," he said. "It should be a part of a routine physical examination." Tucker added that the data his team "allow doctors to determine, based on physical examination, if a person is at moderate risk or very high risk."

Scientists have linked two major air pollutants with mortality rates increased in 12 European cities. The findings, published in the issue of tomorrow British Medical Journal , are sure to fuel a contentious debate in Europe and the United States on proposed standards that greatly reduce exposure to air pollutants.

An international team led by Klea Katsouyanni of the University of Athens analyzed the daily fluctuations in the levels of two pollutants - sulfur dioxide and particulates - and mortality rates in cities. They found that the average increase of 50 micrograms per cubic meter either sulfur dioxide or black smoke (small particles) on a given day was associated with an average increase of 3% of deaths in western European cities studied - Athens, Barcelona, ​​Cologne, London, Lyon, Milan and Paris. Such levels of pollutants, however, have been linked to a lower increase in mortality rates in the cities of Eastern Europe and Central Bratislava, Krakow, Lodz, Poznan and Wroclaw sulfur dioxide is linked to increased 0.8% of deaths, and the black smoke she gave up 0.6%.

we do not know why people in Eastern and Central Europe, with higher levels of pollution means, seem to be less exposed to daily increases in air pollution. "It was not an effect we expected," said Katsouyanni. One possibility, she and other experts speculate, is that older people are more vulnerable to the adverse effects of air pollution and because Europeans East have an expected shorter life, their cities are less at risk.

the regional difference is treated in other studies on air pollution and health of the European Union . A European project approach

The scientists found that immune systems ravaged by AIDS patients can bounce back from the state of the art drug treatment kept the HIV at bay for a year. But the findings, reported in tomorrow's issue of Science * it clear that the complete reconstruction of a devastated immune system of HIV is a challenge, especially given the limitations of treatment available today.

The new HIV treatments are ward off illness and death in thousands of people. To get a better idea of ​​how prices of the immune system after therapy immunologist Brigitte Autran of H ™ pital Pitié Salpétrire in Paris and colleagues analyzed white blood cells or T cells, which have a receptor known as CD4 name on their surfaces. HIV selectively infects the cells of the immune system, leading to their destruction. In time, people with HIV are left with so few CD4 their immune system can not repel even the wimpiest bacteria, viruses or fungi.

A major benefit widely observed in people receiving powerful new treatments is bouncing CD4 dramatically. Yet overall, but most healthy people infected CD4 do not return to normal levels. Moreover, it is unclear whether patients really regenerate CD4 or simply "redistribute" those who were sequestered in the lymph nodes and other tissues. This, in turn, determines how the effectiveness of the "new" are CD4 fight against infections.

The group analyzed the CD4 Autran who returned in eight adults taking a powerful combination of three anti-HIV drugs. After 1 year, the drugs had pushed the virus and CD4 cells had jumped twice. But because all the CD4 are not created equal, the researchers used other markers on the surfaces of these cells in order to classify them as belonging to the "memory" or subset "naive". A memory cell only responds to invaders it has seen before, while the naive cells can initiate an immune response - and create memory cells - against newcomers. In the first 4 months of treatment, the group found, CD4 return were mostly of the memory cells. But after this initial phase, the naive population rose sharply, indicating that the new cells were generated. - And by providing a "directory" more diverse CD4 capable of responding to new invaders

The study is "the best that the analysis of T cells back after a triple drug therapy that I saw "says immunologist Donald Mosier of the Scripps research Institute in la Jolla, California. However, he warns, the chances are "slim to none" that HIV drugs will eventually allow the immune system to replenish completely with fully functional CD4, both because of the limitations of medicine and the ability of the immune system to settle. "I would be really surprised if you can keep doing this year after year," he said. Autran has hope, however. "I'm very optimistic that if we could reduce the level of virus replication enough, we could discuss this, "she said.

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A computer that can diagnose common psychiatric disorders could be a useful aid for busy physicians and make screening more common mental disorders. And for some disorders, patients seem more willing to confide in telephony based system than in their personal physicians, according to a study in tomorrow's issue of Journal of the American Medical Association .

With medical examinations for 10 minutes or less, many primary care physicians do not have time to ask questions that can help diagnose mental illness - and patients do not usually wear volunteers these informations. "There is a high rate of undetected mental disorders in the population," says Kenneth Kobak, a psychologist who led the study at the Dean Foundation for Health, Research and Education, Middleton, Wisconsin. "These people go to their regular doctors in the family, but doctors are not catching it."

So Kobak and his colleagues created a computer to ask questions based on a common questionnaire called the primary care evaluation of mental disorders, which is used to diagnose alcohol abuse, major depression, bulimia and other disorders. They set up an interactive voice response system, similar to that used by many directory assistance for telephone companies, where the computer asks a question, and the listener responds. in the review of 0 patients in four primary care clinics, a clinical eating disorder, and alcohol treatment facility, computer and medical disorders professional each found in approximately 60% of their patients. Even more striking, patients with alcohol abuse were twice as likely to admit their illness to the computer as their primary care physician.

Experts say that the computer system could be a useful aid for busy doctors. "It works very well for what it is, which is a screening device," says Jean Endicott, a psychologist at the College of Physicians and Surgeons of Columbia University, New York. "I think the availability of these types of programs and procedures should certainly improve screening and detection, and hopefully treat these diseases. "

A vaccine against rotavirus significantly reduced the number of deaths from childhood diarrhea in Venezuela, according to a study published in the tomorrow of New England Journal of Medicine . But critics say that the effectiveness of the vaccine has not been confirmed in the poorest countries, where inadequate nutrition could work against her, and they argue that most developing countries will not be able to pay anyway.

Nearly 00,000 infants and children die each year, mostly in developing countries, severe diarrhea caused by rotavirus infections. Although the virus infects almost everyone in the world, it only kills children. A child with severe rotavirus diarrhea can suffer from 10 to 15 episodes of diarrhea and vomiting every day. And although treatment with rehydration salts and the right food can save lives, researchers have worked for years on a vaccine that could reduce the severity of the disease, especially in poor countries health care and developing nutrition.

In the early 190s, Albert Kapikian and colleagues at the National Institute of Allergy and Infectious Diseases developed a vaccine, and tests in Finland and the United States have shown that it could reduce the incidence of severe diarrhea. But in tests in developing countries such as Brazil and Peru, it has reduced the cases of 30% to 45%. Kapikian and his colleagues decided to create their own vaccine trial in a poor urban area near Caracas, Venezuela, with a dose 10 times stronger vaccine

Unlike previous trials -. Which counted all cases in which a child was sick and would not be detected a reduction in the severity of the disease - the researchers counted the number of cases where a child has been hospitalized with severe diarrhea. In the study of 20 infants, the vaccine reduced the incidence of severe disease by 88% compared to the control group. The only side effect of the vaccine was a slight fever.

But other researchers say diarrhea vaccine efficacy in Venezuela does not mean it will work everywhere. Richard Cash, of the Harvard School of Public Health and Harvard Institute for International Development, explains the impressive results in Venezuela could be due to better nutrition that strengthens the immune system, and a lower rate of overall diarrhea than Brazil or Peru. "What you really need to do is try to Bangladesh or in countries in sub-Saharan Africa where sanitation is worse," he said. Treasury also emphasizes that, at $ 30 per dose, the vaccine is too expensive for many developing countries, where five average annual health care spending only $ $ 20 per person.

For vaccines to teach the body to recognize a pathogen, they must insert a diagnostic fragment in macrophages and other cells of the immune system. Viruses can do the job, but they can be dangerous - especially in patients whose immune system is already weakened by a viral infection. Now researchers report that a single bacterial protein may act as carrier, priming the immune system to respond to specific foreign proteins. The new technology, reported in the current issue of Proceedings of the National Academy of Sciences could be adaptable in a delivery system for vaccines against AIDS.

The key to the new technology is a protein called hsp70, which belongs to a group of proteins called "heat shock proteins" or "stress proteins" have been found in bacteria and higher organisms. These protein strongly stimulate the immune system of mammals. in recent years, several research groups have created vaccines that protect mice against cancer by injecting them isolated stress proteins from own tumor cells of the mouse. Now, Rick Young immunologist and his colleagues at the Whitehead Institute and Massachusetts Institute of Technology have coaxed a mouse immune system to recognize other proteins by attaching them to a heat shock isolated tuberculosis bacilli proteins and injecting the combination into the animal.

the group has created a prototype vaccine to mice by binding a protein to chicken ovalbumin called hsp70 tuberculosis proteins. They then implanted in mice genetically a cancer cell line festooned with the ovalbumin protein. Generally, these cancer cells overwhelm the immune system of the host. But because hsp70 somehow made known target the immune systems of host mice, ovalbumin on cancer cell surfaces was like a bull's eye in the sights of a sniper. The mouse immune system responded enthusiastically, killing invasive cancer cells. After 40 days, 80% protected mice were still alive, whereas all the control mice died of tumors.

Heat shock proteins are "much safer" than viral vaccines, said Michael Starnbach, immunologist at Harvard Medical School in Boston. And although researchers do not know how the heat shock proteins to sneak into killer T cells, they might be able to deliver almost any antigen. "It's exciting," says Starnbach.

Blood vessels, such as highways and roads that reach most addresses, run through almost all tissues of the body. The problem for doctors is that drugs of this transportation system moving almost everywhere find their way to many more nooks and crannies than they are supposed to. Now, German researchers have found a low-tech solution to get the goods to specific places of the body: tiny polymer spheres with drugs that can be accommodated in specific sets of narrow vessels called capillaries before releasing their loads. The technique, reported in the next month of Nature Biotechnology , could provide a new vehicle for delivering drugs to people with heart disease and other ailments.

heart attacks occur when clogged arteries prevent the heart to circulate enough blood to sustain itself. Treatment is possible to create new pathways for blood to reach the heart muscle using a protein called fibroblast growth factor (FGF) to stimulate the growth of new blood vessels. FGF, use has however not found widespread as a treatment again because of two major problems :. Enzymes quickly disable FGF outstanding, and high doses can dilate blood vessels and lower blood pressure dangerously

To deliver FGF where it is needed more precisely, a team led by physiologist Wulf Ito Institute Max Planck physiology and clinical research in Bad Nauheim, Germany, FGF attached to small letters - resin spheres, 7 micrometers in diameter, which are too big to squeeze through capillaries. A sphere of drug loaded "looks like a golf ball with FGF in small bumps," says Ito.

The researchers tested the technique on healthy pigs, injection of spheres in an artery feeds a part of the heart muscle. in seconds, 60% of the spheres inserted into capillaries fed by the artery. the remaining 40% were probably slightly smaller and squeaked through, said Ito. Do not worry, the rest of body "gets a very, very small dose," he said. Indeed, the remaining spheres were so diffusely distributed outside of the heart tissue that researchers could not find one.

If other research shows that injecting spheres trigger a new hair growth, they could have "huge clinical implications," said Elazer Edelman, director of the Harvard-MIT biomedical engineering Center in Cambridge, Massachusetts. Already, similar spheres get their first test in people: Edelman has conducted tests in which FGF-bearing areas are located in people's chests as they are open for coronary bypass surgery. "It will be interesting to see how these injectable spheres work in clinical trials," he said.

New blood test can quickly reveal whether a child has a bacterial infection. If the test, described in the March Journal of Pediatrics , can be developed for widespread use, it could help doctors save the lives of some infants, as well as millions of dollars in treatments for babies appear to have infections.

Because infants are so vulnerable to infections, doctors must make hasty decisions as to whether a baby who looks ill really needs an antibiotic. Often wandering on the safe side, the doctors end up treating 17 healthy babies for everyone who is later confirmed to have an infection. For a decade, immunologists have sought a molecule in the immune system of the newborn which could serve as a warning flag for an infection. But the molecules tested so far, none have been proven.

Leonore Herzenberg, Erica Weirich, and their colleagues at Stanford University Medical Center has undertaken to develop a simple blood test for the latest and most promising sentinel molecule called CD11b. The molecule appears on the surface of neutrophils, a type of immune cell, within 5 minutes of being exposed to a bacterial toxin called saccharide lipopoly. Researchers designed a fluorescent marker that clings to CD11b and can be accessed regularly by Laserlight. They screened blood of 106 children suspected of having an infection, or high risk for one. They also come with a proven, but slower test for an infection that flags C-reactive protein (CRP). Every 15 babies tested positive for CRP, which is produced in large quantities during infection, were also positive for CD11b. In addition, there were no false positive results CD11b.

If confirmed, the results "could ultimately change how doctors decide how to treat newborns," said Herzenberg. But Robert Baltimore, a pediatrician at Yale University Children Hospital, is not so sure. Although the test "has a very high predictive value", he said, he could suffer the fate of many previous laboratory tests for babies - doctors ignore. "Very often, they will order the test and treat babies anyway," even if the test comes out negative, he said.

Blood is known spiral as it flows through the arteries, but researchers at a conference Royal Academy of Engineering announced yesterday in London that the helical flows Whirl like a corkscrew. In addition, the twists and branches of blood vessels promote the swirling flow, which runs through the plaque and helps prevent atherosclerosis.

Until recently, researchers lacked the power of the computer to accurately model the blood flow in the complex, three-dimensional geometries, said Spencer Sherwin, a fluid dynamicist at Imperial College London science, technology and medicine. But a new computer program written by Sherwin and colleagues seems to have finally managed to accurately model the arterial blood flow: Their calculations correspond to the MRI data on the speed of blood within the arteries, says Danesh of Tafti national Center for Supercomputing Applications in Champaign, Illinois.

the new program could open the way for more sustainable arterial grafts, natural or artificial replacements for the arteries, which do not work mate Colin said Caro, a physiologist also at Imperial College. About half of arterial grafts fail in 10 years, after being blocked by a thickening of the inner wall. This can happen because surgeons tend to join grafts perpendicular to the vessel wall in a single flat plane, rather than the curve as a freeway onramp that ships are natural.

Sherwin now considering the use of simulations and real arteries MRI to determine the optimum angle of arterial grafts to maintain swirling blood flow that could prevent blockages.

"the results of the blood are obviously important to improve arterial graft construct," said Michael Bettmann, a cardiovascular specialist at Medical Center Dartmouth-Hitchcock Dartmouth in New Hampshire, "but they can also be useful to the development of new techniques, primarily those not operating for the treatment of peripheral arterial disease. "

AIDS patients survive longer these days, but most still succumb to opportunistic infections that escape an immune system weakened by HIV. Now, however, scientists have evidence that immuno-cell field which stops naturally with age may be able to return to active duty in some people. The discovery, reported in the current Journal of Clinical Investigation , suggests that the body could resume production of certain immune cells after the drug hitter HIV in submission

immune cells called T lymphocytes - . Frontline troops into battle against foreign microbes - are produced in the bone marrow and then battle prepared in the thymus, a small gland at the base of the neck. This training is considered to occur before birth until puberty, when the thymus atrophy and is generally thought to stop functioning. In adulthood, according to most medical textbooks, thymus treated the T cells enough to deal with most microbial invaders one person is likely to encounter in a lifetime. But attacks against HIV destroys T-cells, leaving patients infected defenseless against many pathogens. Nevertheless, some studies have shown that patients on powerful new antiviral therapies seem able to regenerate some of these cells once viral loads were reduced for a sufficient period of time -. Leading researchers to question the source of these new T cells

To see if the thymus may be the source of these new T cells, immunologist Joseph McCune and his colleagues at the Gladstone Institute of Virology and immunology in San Francisco thymus size measured in 99 HIV-positive patients. The team used a technique called computed tomography, which creates an image in three dimensions X-ray of internal organs. About half of the subjects had a much more thymus tissue that HIV-negative controls. In addition, the size of the thymus gland of a subject closely related to blood levels of T cells - indirect proof that the thymus may be working and the release of these immune cells, say the authors

Experts warn that rejuvenation. thymus tissue alone does not prove that the gland is working properly. Yet the results are "a good argument" for a revival of the thymus function, says immunologist Brigitte Autran of the Pitié-Salpêtrière Hospital in Paris, whose team discovered some of the first evidence that immune reconstitution could be possible. "It is clear that the immune system is more difficult to try to raise the number of T cells," adds Mario Roederer, an immunologist at the University of Stanford.

An epilepsy drug used in Europe removes key signs of addiction to cocaine in baboons and rats, according to a study in Synapse this week . If confirmed in human studies, the finding may lead to a new way to help cocaine addicts kick the habit.

The drug, called gamma vinyl-GABA (GVG), seems to erase a chemical characteristic of cocaine and other addictive drugs: a surge of dopamine, a neurotransmitter in the brain's reward centers. GVG does not act on dopamine directly, but increases levels of a neurotransmitter called gamma-aminobutyric acid (GABA) that acts as a brake on dopamine release; that GABA may boost curb excessive neuronal activity leading to seizures. In the early 190s neuropharmacologist Stephen Dewey of Brookhaven National Laboratory in Upton, New York, and colleagues began to test whether GVG also removes dopamine-induced increase in cocaine.

In the current study, the team gave Dewey cocaine 20 baboons, some of whom had previously received injections of GVG and followed dopamine levels in the brain baboons using a technique imaging called positron emission tomography. While cocaine produces a large increase in dopamine in baboons not given GVG, the researchers did not see this increase in animals treated with GVG, suggesting that the drug "blocks the neurochemical action of cocaine," says . -member of Charles Ashby team, neuropharmacologist at St. Johns University in Jamaica, New York

the researchers then investigated whether GVG could also block a behavior related to drug addiction in rats: their tendency to return to a place they had already received an addictive drug. This behavior reflects the ability of rats to link environmental signals with drug taking, an association that often triggers drug cravings in people. researchers discovered that GVG stopped the behavior, indicating that it could weaken drug cravings.

"We hope that GVG will dramatically reduce the tendency of an addict back to cocaine," said Ashby . Of course, if this hope is realized will depend on the results of clinical trials are expected to begin later this year. "This is obviously something that should be followed," said Frank Vocci neuropharmacologist of the National Institute on Drug Abuse.

A drug combination therapy for hepatitis C cured almost half of the patients tested. Experts say the results described in tomorrow New England Journal of Medicine , make a good case to give both ribavirin and interferon alfa-2b as a standard treatment. But they note that more effective drugs will be needed to eliminate the virus in all patients

One of the most common infections in the world., Hepatitis C is carried by about 170 million people . While most people have no symptoms, about 20% develop chronic inflammation that scars and destroys the liver. The virus kills about 10,000 people each year. Until recently, the only accepted treatment was 6 months interferon repeated injections to stimulate an immune response against the virus. This approach, experts say, is able to cure less than 20% of patients who undergo this. Recent clinical trials have shown that the antiviral ribavirin may enhance the effectiveness of interferon, but few patients were tested.

Two teams have now studied the combo drug in randomized controlled trials. John McHutchinson the Scripps Clinic in La Jolla, California, gave daily doses of the association or interferon alone in 912 previously untreated patients. After 6 months the combination had cleared the virus from the blood of 31% of the subjects in this group. "For a chronic condition, we have something that is very impressive," said McHutchinson. Another trial, conducted by Gary Davis of the University of Florida, Gainesville, tried the combo drug on 345 patients who had been treated successfully with interferon alone, but later relapse. This cured 49% of patients. (the success rate is higher than in the Scripps trial because the relapsed patients Florida trial have been known to respond to interferon.) the studies were funded in part by Schering-Plough, which makes both drugs.

the results represent "a breakthrough in the treatment of hepatitis C," says Jake Liang, a researcher at the National Institute of diabetes and digestive and kidney diseases. But he says it will take the discovery of new drugs to see the most dramatic improvements in treatment.