Health Meaning

- Young women with irregular periods may be at higher risk of developing and dying from cancer of ovary-later in life, researchers have found a 50- year study of women in California. The new research provides the first evidence linking the abnormally long periods or cycles missed at a higher risk of ovarian cancer. He also challenges a hypothesis long as the risk increased progressively with the total number of ovulations a woman.

Having fewer ovulatory cycles is widely regarded as a protective factor against ovarian cancer. It is why hormonal birth control pills, pregnancy and tubal ligations, which stop ovulation were thought to reduce the risk of this disease. "This study is certainly curious, because it contradicts what we thought we knew about ovarian cancer and the incessant ovulation," says Mitchell Maiman, an OB / GYN at Staten Island University Hospital in New York.

Although ovarian cancer accounts for only 3% of all cancers in women, it is the main cause of death from gynecological cancer. Less than half of women diagnosed with ovarian cancer survive more than 5 years. The first symptoms, including abdominal pain and bloating, often go unnoticed or are misdiagnosed as irritable bowel syndrome. Because there is no routine testing and some markers to identify groups at increased risk of ovarian cancers, most cases are when they are beyond the point of cure. Age is a risk factor for more than half of all ovarian cancers are diagnosed in women aged over 63. Heredity is another 10% to 15% of women diagnosed with cancer of the ovary have one or more genetic risk factors more known.

To identify other risk factors, epidemiologist Barbara Cohn, director of studies on the development of children's health from the Institute of Public Health and Oakland, California, and colleagues analyzed data from more than 15,000 women from California who enrolled in a study of pregnancy in 1959. This study sought to keep the risk of disease during the lifetime of the mothers and their children. Irregularities-defined as cycles lasting 35 days or a long-term history of rare or missed menstrual periods were reported at the beginning of the study, while the average age of the women was 26. About 13% of women reported irregular periods.

Over the next 50 years, 116 women developed ovarian cancer, 84 of them died. Women with a history of menstrual irregularities were almost twice as likely as women with normal periods to develop ovarian cancer and die from it by the age of 70. This link increases with age , the researchers report in the number of the month of International Journal of Cancer . For example, women with menstrual irregularities were about three times more likely to develop and die from ovarian cancer 77 years compared to women with normal periods. At that time, the risk of irregular periods was as great as the risk for women with a family history of the disease, said Cohn.

The researchers say it is likely that many women in the study who developed ovarian cancer also suffered from a hormonal disorder called polycystic ovary syndrome (PCOS). PCOS is often characterized by irregular or absent periods. But it is impossible to know for sure, because these diagnostic criteria were established after the beginning of the study. PCOS is a known risk factor for endometrial cancer, although previous studies on the link between PCOS and ovarian cancer were found results with a certain mixture pointing to an increased risk, some pointing reduced risk, and others turn up no significant association.

Maiman said the new study may guide future research not only about who is at risk for ovarian cancer, but who could benefit from screening efforts or prevention. "If validated it could give us another risk assessment factor for determining people at high risk where screening is prudent."

But the design of this type of research will require more answers grained several key questions, said Mia Gaudet, a cancer epidemiologist who is the strategic director of breast and cancer research gynecological cancer at the American Society in Atlanta. "Research is beginning to show that the characteristics of the menstrual cycle may be more important than the number. For example, were the heaviest periods that someone who was cycling regularly? A study designed today would ask different questions, "says Gaudet." [This is] a first step that deserves a closer look. "

Antibiotics have been taken on the chin lately. Not only drug resistance increases, but pharmaceutical companies have dropped antibiotic research programs because drugs are difficult and expensive to manufacture. Now, help is on the way. Researchers now report that they have found a way to multiply the new members of one of the most common classes of antibiotics called macrolides. The work could lead to new weapons against antibiotic-resistant infections, and maybe save millions of lives.

macrolides, medications that include erythromycin and azithromycin, were first developed in the 1950s Since then, they have become a bulwark against bacterial and fungal infections. Chemically, macrolides are giant rings containing 14 to 16 carbon atoms, with one or more sugar appendages that hang on the side. Bacteria synthesize them fight their neighbors. However, the bacteria did not evolve to make good macrolide drugs in people. So chemists medicinal group of researchers who are actually building new startup drug with natural versions and modify their links one at a time in an effort to make them safer and more efficient. But in most cases it is impossible to limit the changes to a single link on a large molecule. When multiple bonds are reacted, the result is an unwanted mixture wide finished product, none of which contain only a desired specific modification to make a better drug.

To solve this problem, a chemist at Harvard University Andrew Myers and his colleagues adapted a strategy of divide and rule they applied antibiotic tetracycline in 05. They started with three basic structures macrolide ring and broke down in each molecular eight modules "." They then carefully mapped reactions necessary to put the pieces together. For two of these linkers have even invented new chemical reactions to forge links so. This allowed them to tinker with the modules individually and then reassembled. Repeating the strategy several times, they forged more than 300 completely new macrolides.

When administered to a group of bacterial laboratory cultures, many of these compounds showed potent antibiotic activity against microbes resistant to antibiotics, including methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus reports online today in Nature of the team . Perhaps as important, Myers said, is that all reactions used to assemble produce high yields of the final products. This is essential, he notes, because bacteria do not produce the starting material for the novel compounds. So if one of them is a valuable medicinal chemists will be able to synthesize large quantities cheaply from scratch.

"This is an excellent example of the beautiful chemistry will have a tangible societal benefit," said Phil Baran, a chemist organic synthesis at the Scripps Research Institute in San Diego, California. Myers has set up a company, macrolides Pharmaceuticals, to market the work.

Zika virus, the pathogen once obscure now widely feared to cause birth defects and other problems, has spread far very quickly since an outbreak was first noticed in northern Brazil in early 2015 it reached more than 40 countries throughout the Americas, even making the Cape Verde islands off the west coast of Africa. More than a million people have been infected.

As public health officials are trying to contain the epidemic, researchers are racing to answer a key question with important implications for which risk areas, and what methods might work to slow its spread: What mosquitoes transmit the virus? Responding to the question is a challenge. Scientists need evidence of both mosquitoes bred and wild caught laboratory to make the case that a given species is guilty.

Last week, a Rio de Janeiro team announced it had caught several Aedes aegypti infected Zika first-infected mosquitoes found in Brazil. Species, the yellow fever mosquito, has long been the main suspect, but some scientists believe that the virus must have Zika other carriers have spread so quickly and have field studies and laboratory courses for solve the problem. Until the evidence is, "we must not jump to conclusions," said Duane Gubler, a virologist at the medical school Duke-NUS in Singapore.

A. aegypti won suspicion because it spreads dengue and chikungunya and yellow fever is common in urban areas of Brazil where major outbreaks occurred and throughout Latin America. But evidence of wild mosquitoes infected Zika was lacking. It is more difficult than one might expect to find them. In dengue outbreaks, says Sander Koenraadt, entomologist at Wageningen University in the Netherlands, researchers generally find that less than 1% of the sampled mosquitoes are infected with the dengue virus, even when people get sick. "You have to watch a lot of mosquitoes to find [infected ones]," Gubler said. Mosquitoes "infect people and die before anyone shows up at the hospital" with the symptoms of the disease, said Oliver Brady, an entomologist at the University of Oxford in the UK.

For insects to transmit a virus they must infected blood from a human or animal and become infected themselves. The virus then travel from the gut to their saliva. Only a few species are susceptible to particular viruses.

To test whether a given species is able to transmit a virus, researchers feed on insects on the infected blood in the laboratory and a week later to collect saliva from them. If saliva contains infectious virus, the species is considered a "competent" vector. Not all competent laboratory vectors spread the disease, however. This depends on several factors such as the frequency with which species stings if it feeds mainly on humans or other animals, and how long he lives. To confirm that a species transmit the disease, researchers also need to find mosquitoes infected with the virus in nature.

You have to watch a lot of mosquitoes to find [infected ones].

the team that reported the first mosquitoes Zika-infected in Brazil, led by Ricardo Lourenço de Oliveira, entomologist at the Oswaldo Cruz Foundation (Fiocruz) in Rio de Janeiro, vacuumed mosquitoes from homes and streets in parts of Rio de Janeiro where people lived complain Zika symptoms. Over 10 months, they collected more than 1,500 mosquitoes, identified and tested pooled samples of the same sex and species for the presence of Zika and other viruses. Nearly half were A. aegypti , and most of the others were Culex quinquefasciatus , another common mosquito in urban Brazil. About 5% were other species. A species called A. albopictus , widely known as the Asian tiger mosquito, which can also transmit Zika in the laboratory and was found infected by the virus in Mexico and Gabon, made only about 2% of the capture, Lourenço de Oliveira said. They found Zika virus in three sets of women A. aegypti mosquitoes, but none of the other species.

The absence of viruses in C. quinquefasciatus is somewhat reassuring, Lourenço de Oliveira said, but the case is not closed. Constância Ayres, entomologist at Fiocruz in Recife, Brazil, said his laboratory has evidence that the species is a possible vector; they found the Zika virus in the saliva of C. quinquefasciatus who had fed infected blood. (His team presented its work for publication.)

Lab tests can be misleading, however. "There is a classic discrepancy between what you see in the lab and what happens in nature," says Brady. " albopictus and aegypti are both very competent in the laboratory "as vectors of dengue." But in Europe, where we have generalized albopictus and almost no aegypti , you do not have huge dengue outbreaks. "

Ayres and others are still looking for Zika in nature. She and her colleagues have collected and identified over 5,000 mosquitoes in the Recife region since March, from homes where patients lived Zika confirmed and emergency care centers. it expects the money to the promised subsidy before it can perform the reaction tests polymerase chain to find the virus mosquitoes are carriers, she said.

Culex mosquitoes transmit several viruses related to Zika, and it would not be particularly surprising if both Culex and Aedes species could spread Zika, Ayres said. Gubler should Culex is a plausible carrier. He noted that several relatives Zika propagated by Culex mosquitoes, including West Nile virus, targeting the nervous system, which also seems to Zika.

If Culex Mosquitoes can transmit Zika virus, which will slow its spread even more difficult. C. quinquefasciatus is located as far north as Iowa and Indiana in the US, although people there are protected by mosquito nets and other factors. In Latin America, most vector control methods are targeted A. aegypti . These efforts have made barely a dent in curbing the spread of the virus so far Zika said Paul Reiter, an entomologist at the Pasteur Institute in Paris. Targeting multiple vectors at once will only make the task more difficult. "If [ C. ] quinquefaciatis is a vector," he said, "we can not say enough about mosquito control."

LONDON - A team of British scientists announced new evidence linking disease today degenerative fatal brain that killed 10 people in Britain since 1994, with bovine spongiform encephalopathy (BSE), a neurological condition known as `` the mad cow '' that has infected more than 150,000 cattle British.

The researchers have developed a test that reveals strong similarities between proteins considered responsible for human disease - a new variant of Creutzfeldt-Jakob disease (vCJD) - and those related to the BSE. `` This is the most suggestive evidence so far that the new variant CJD came from BSE, '' said Byron Caughey, a biochemist at the National Institute of Health Rocky Mountain Laboratory (NIH) in the Montana. All experts agree, however.

At a press conference this morning, John Collinge of Imperial College School of Medicine at the hospital, St. Mary London, said the simple test distinguishes the differences between the infectious proteins, or prion, isolated from the brain of humans or infected animals. Researchers decompose prion with an enzyme and separating them depending on the number of sugar groups attached thereto. relative abundances of proteins with different numbers of sugar groups produce characteristic patterns of BSE, classical CJD and the new strain of vCJD. The report will appear in tomorrow Collinge Nature

Collinge's team found that the prion model of vCJD. - That hit the victims up to 45 years - looks much closer to the ESB model of people with classic CJD, a common condition, although rare, which tends to hit the elderly. But because the new test requires brain tissue, it is usually possible to run after a patient died. The team now hopes to detect proteins in other tissue of the body that could be sampled while the patient is still alive. They analyze the lymph nodes and tonsils, where prions replicate. Collinge hope to have the results of such a test in a few months. With a potentially test can detect the disease early, `` we should seriously consider developing therapeutic products, '' said Collinge.

But some experts welcomed the results with caution. `` It's an interesting idea, but not compelling, '' said Paul Brown, a neuroscientist at the main campus of NIH in Bethesda, Maryland. Brown said he is skeptical that the differences between the forms of prions revealed in the new trial account for variations of CJD, and awaits the results of experiments on transgenic mice. Mice produce human prion which, when modified, is bound to vCJD. The mice were injected with brain tissue of victims of vCJD, but so far none have contracted CJD. Results are expected next year.

WASHINGTON, DC - Prompted by the alarming statistics on the incidence and costs of sexually transmitted diseases (STDs) in the United STATES, called a blue-ribbon panel of medical today for a national campaign against this epidemic under-reported.

Each year more than 12 million people in the United States, a quarter of them teenagers, are infected with STDs or suffer long -term effects such as pelvic inflammatory disease - a rate infection much higher than in other developed countries, said the panel, which was appointed by the Institute of medicine. Many of these diseases - including herpes and STDs "modern" such as hepatitis B and AIDS - are caused by viruses and are thus difficult or impossible to cure. The overall picture, said David Celentano School of Hygiene and Public Health at Johns Hopkins University, is "a national disgrace."

In a report entitled "The hidden epidemic", the committee, led by internist William T. Butler, Baylor College of Medicine in Houston reconstructed a disturbing picture emerges in the scientific literature and government data. Here are some highlights:

• * Teens are the most at risk of contracting STDs group but only 11% of adolescents reported got the facts of life --basic information about sex, that is -. parents

  * By 12th grade, 70% of teens have had sex, and nearly 40% of them have had four or more partners

  * In 1994, pelvic inflammatory disease has accumulated the most medical expenses -. $ 4.15 billion -. any STDs other than AIDS

  * US Gonorrhea rates are 50 times higher than they are in Sweden.

The exposure to STDs is commonplace and "hidden" for a number of reasons, the report said. He said that parents and teachers do not like to talk about negative consequences of sex, some doctors are ignorant of the insidious nature of STDs, and many problems have no symptoms in the early stages, particularly in women. Increased awareness of AIDS and how it spreads is forcing the MST on the closet, said Celentano, a committee member. "Probably the number one risk [factor] HIV is an STD," he said.

The report calls for a national campaign to educate the public and doctors about STDs and believes that health care providers must make a special effort to monitor and treat the partners of STD patients. This recommendation, Butler said, aims to bacterial infections easily curable such as gonorrhea, syphilis, and chlamydia.

In recognition of the amazing advances in clinical and basic research on AIDS, the editors of Science chose new weapon against HIV as the discovery of the year for 1996. price, an annual event welcomes new drugs and a new understanding of how the virus infects cells - advances that bring hope people infected with HIV after years of stalemate in the war against AIDS.

an article describing the context of the award notes that these developments started last December, when the first of a new class of drugs, protease inhibitors, came on the market. protease inhibitors stuck the active site of a key enzyme of HIV and, when taken in combination with AZT or other drugs can reduce the virus to undetectable levels in the blood. These cocktails of powerful drugs are no miracle solution, and only a fraction of HIV-positive people can afford to take, but they block the virus to an unsuspected degree ago few years.

In basic research realm, science notes that this year the researchers identified HIV long sought factors. They proved to be of chemokines, small molecules to polypeptides that are part of the arsenal of natural arms of the immune system. In a series of reports throughout the years, researchers have found that, to enter a cell, HIV must first bind to a cell surface receptor which normally receives chemokines, and the virus can not not infect people born with defective chemokine receptor. This idea opens the door to new treatments and vaccines perhaps.

Science also honored nine stages of research with potential benefits to society as a finalist for discovery of the year. They include research on the origins of life, which ignited the imagination of the public with evidence of possible past life on Mars; new types of lasers that could one day make better CD-ROM; and decoding programs cellular self-destruction, which may have implications for research in diseases such as cancer and stroke.

A controversial new study has put a cloud over one of the most spectacular successes in AIDS. The anti-HIV drug AZT, when administered to pregnant women infected with HIV, can reduce the likelihood of mother to child transmission by almost 70%. But a study in pregnant mice now suggests that, at very high doses, the drug can cause tumors in the offspring. The manufacturer of the drug, however, has evidence suggesting that AZT in prescribed doses is safe. To get to the bottom of things, the National Institutes of Health convened a group of experts in Washington, DC, which plans to issue a recommendation tomorrow morning.

The disturbing new study, led by Lucy Anderson the National Cancer Institute, shows that megadoses pregnant mice given AZT gave birth to puppies that were more likely to develop liver tumors, lung and genitourinary tract. The Anderson team found that AZT - which stops the AIDS virus to copy itself by interfering with the synthesis of viral DNA -. was incorporated into the DNA of the puppies in a variety of fabrics, they may think leads to tumors

at lower doses, however, there is no evidence of cancer risk . When researchers at Glaxo Wellcome, which makes AZT, administered pregnant mice doses similar to those given to people, they found no increased risk of tumors in the offspring. Scientists have not seen evidence that children of AZT-treated mothers have higher rates of tumors. In addition, said Jack Killen, head of the AIDS division at the National Institute of Allergy and Infectious Diseases, researchers have known since 1989 that AZT can cause cancer in mice and yet have not seen an increase tumors in adults on medication.

group meeting today heard presentations Anderson and Glaxo Wellcome researchers and is now deliberating on the data. In principle, the committee could advise the Ministry of Health and Social Services to reverse its current recommendation that pregnant women with HIV take AZT to prevent transmission to newborns. But this is unlikely. "Many people have watched this - ethicists, clinicians, basic scientists - and everyone agrees there is no basis to change the recommendation," says Killen, the panel chair Yet said. -it, "we need to supervise children carefully and thoroughly provide information to the public so that women at the decision to have him."

university officials applauded a federal appeals court decision to throw accusations by a former graduate student in his school defrauded the federal Government wrongly taking credit for his work in grant applications. On January 22, the Appeal Court firmly rejected the accusations made by the applicant, nutritionist Pamela Berge, easing fears of universities they could face a wave of similar lawsuits.

The lawsuit stems from working Berge in 1987 as a researcher study visit cytomegalovirus (CMV) at the University of Alabama, Birmingham (UAB). Three years later, a graduate student accused Berge UAB plagiarizing his work. The university has conducted two surveys, but found no fault, and the Department of Health and Human Services apparently refused to take the case. Thus in 1993, Berge prosecuted under the False Claims Act - which allows "qui tam" lawsuits by citizens who allege fraud in government contracts - saying UAB and four of its researchers had made false statements in grant proposals to the National Institutes of Health (NIH), which funded the work of CMV. In 1995, a federal court in Baltimore UAB ordered to pay $ 1.65 million and researchers $ 10,000, of which 30% went to Berge.

The 4th US Circuit Court of Appeals in Richmond, Virginia, however, was not persuaded by allegations of Berge. He found that the alleged false statements "are not significant to [NIH's] funding decisions, and ... in fact, are not even wrong." And the court found that Berge, when a doctoral student at Cornell University, had overestimated his contribution: "The pride of any graduate student to think that these subsidies depend on the results of his work is beyond belief This is not the way. Big science works "One of the lawyers Berge, Alexander T. Bok Boston, said she will appeal

university groups -.. Including several filed amicus curiae briefs in the case - the language hope scathing court discourage other qui tam suits. the decision, said the lawyer of the UAB, Barbara Mishkin Washington sends the message that this kind of dispute between the co-authors "are not a federal case. "

The people with cystic fibrosis are prone to lung infections killer. However, scientists have attempted to understand how the underlying genetic defect of the disease - a mutated gene that leads to poor transport chloride in and out of cells - favors these infections. Now comes a possible explanation: An antibiotic that normally produces the lung is inactivated in a salty environment. The discovery, published in the current issue of Cell , suggests that the passage somehow the antibiotic back on - or replace it with another that can run into the salty lung fluid - could reduce the number of fatal infections.

Last year, researchers found that certain strains of bacteria are tame in low salt lung fluid of healthy people, but thrive in the salty lung fluid of patients with cystic fibrosis. Now a team led by James Wilson of the Institute for Human Gene Therapy in Philadelphia and Michael Zasloff of Magainin Research Institute in Plymouth Meeting, Pennsylvania, seems to have found what distinguishes these pulmonary fluids apart. They found in human lung cells messenger RNA that helps make a protein called human -defensin, first isolated from the kidney dialysis fluid it a few years ago.

In the presence of poor liquid salt, they found, a synthetic version of the human -defensin was a powerful weapon against a broad spectrum of bacteria, including P. aeruginosa and E. coli , two bugs that afflict people with cystic fibrosis. But when exposed to high levels of salt, human -defensin was virtually powerless. "It helps to fill this gap on how a defect in an ion channel leads to defects in the lungs," says molecular biologist Mark Anderson Magainin institute.

Not everyone is convinced that all people with cystic fibrosis have pulmonary salty liquid. Nevertheless, the experts welcome the conclusion. "It's very exciting," said Charles Bevins of the Cleveland Clinic, who helped isolate -defensins trachea of ​​the cow and the gastrointestinal tract. Bevins said
human -defensin could be used as a medicine to fight against infections of cystic fibrosis lung if researchers are able to modify it to withstand high levels of salt. drugs most likely candidates, he said, are Protegrin, a compound isolated neutrophils pork or microbial peptides called magainins there first isolated 10 years from frog skin, some of which are better than defensins in salt solutions.