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Thứ Tư, 8 tháng 5, 2013

BPA linked with lower testosterone

BPA is found in some plastics, canned food containers and other food packaging, and most people in the U.S. have the chemical in their urine.

Chronic exposure to the chemical bisphenol A (BPA) may lower testosterone levels in men, a new study from China suggests.

In the study, men who were exposed to BPA because they worked in a chemical plant for at least six months had lower levels of testosterone in their blood compared with those who worked in a tap water factory.

Specifically, chemical plant workers had reduced levels of "free" testosterone, which is the form thought to have the greatest influence on the body. (Most testosterone in the body is not "free," but is bound to a protein.)

The findings provide even more evidence that BPA may change men's sex hormone levels, said study researcher Dr. De-Kun Li, a senior research scientist at Kaiser Permanente's Division of Research in Oakland, Calif.

Previous studies, also conducted on Chinese factory workers, have suggested that BPA may lower sperm counts as well as increase the risk of sexual dysfunction in men — health effects that are controlled in part by sex hormones.

BPA is similar to the female hormone estrogen, meaning that it could have effects on the human body. The effect of BPA on men may be more immediate and easier to detect than the effect on women, because men have very low levels of estrogen to begin with, Li said. [See Is BPA Really a Health Hazard?]

However, whether similar effects would be seen in the general population at lower exposure levels is not known, and need to be studied further. BPA is found in some plastics, canned food containers and other food packaging, and most people in the U.S. have the chemical in their urine.

Heather Patisaul, an associate professor at North Carolina State University who studies the effects of BPA, noted that the study looked at BPA in the blood, rather than the urine. BPA levels in the blood are thought to be a better measure of chronic exposure to the chemical, but are typically very low, and could be influenced by environmental contamination, Patisaul said.

Men who don't work in a chemical factory would likely have BPA levels in their blood that are too low to detect, Patisaul said. In the study, about 70 percent of men who worked in the chemical plant had detectable levels of BPA in their blood, while the same was true of 5 percent of those who worked in the water factory.

"This data should not raise alarm bells for men who don't work in chemical factories," Patisaul said.

Patisaul said that the new study was small and did not do a great job of accounting for differences in hormone levels that might be due to the time of day samples were collected.

The study was published online May 6 in the journal Fertility and Sterility.

View the original article here

Thứ Sáu, 26 tháng 4, 2013

Salmonella outbreak linked to cucumbers sickens 73

An outbreak of Salmonella linked to cucumbers imported from Mexico has sickened 73 people in 18 states, according to an announcement today from the Centers for Disease Control and Prevention (CDC).

People affected by the outbreak became ill between January and April of this year. So far, 14 patients have been hospitalized, but no one has died, the CDC said.

States with the most reported cases include California (28 cases), Arizona (nine cases) and Minnesota, (eight cases.) Cases also have been reported in Colorado, Idaho, Illinois, Louisiana, Massachusetts, Maryland, Nevada, New Mexico, North Carolina, Ohio, Oregon, South Dakota, Texas, Virginia and Wisconsin.

After an initial investigation, the source of the outbreak appears to be imported cucumbers from two companies in Culiacán, Mexico: Daniel Cardenas Izabal and Miracle Greenhouse, the CDC said.

Two-thirds of the 45 patients interviewed by investigators reported eating cucumbers before they became sick. Currently, there's no evidence that the contaminated cucumbers are still being sold in stores, the CDC said. But the agency is blocking cucumber imports from the two Mexico-based companies until they can show that their cucumbers are not contaminated.

All patients were sick with a strain of bacteria called Salmonella Saintpaul. Symptoms of Salmonella food poisoning include diarrhea, fever and abdominal cramps. People typically become ill from Salmonella about 12 to 72 hours after eating food contaminated with the bacteria, the CDC said.

Consumers should wash all produce — including cucumbers — before eating, cutting or cooking, the CDC said.

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Thứ Tư, 13 tháng 3, 2013

Rare meat allergy linked to ticks found in kids

Some children living in the U.S. Southeast have a rare meat allergy linked to tick bites, according to a new study.

Bites from ticks, usually lone star ticks, cause the body to become allergic to a protein called alpha-gal — which also happens to be found in some mammals, including cows, pigs and sheep, the researchers said. When people who have been bitten develop this allergy, and then eat meat from these animals, they can experience hives, swelling, or more rarely, a life-threatening allergic reaction known as anaphylaxis.

Cases of the meat allergy in adults were first reported in 2008, and have been on the rise in recent years, the researchers said. The new study is the first to describe the allergy in children, said study researcher Dr. Scott Commins, an assistant professor of medicine and pediatrics at the University of Virginia.

The study identified 45 kids with the allergy who visited clinics at the University of Virginia or in the surrounding area. All of the children had experienced recurrent hives or anaphylaxis, and tests revealed they had antibodies against the alpha-gal protein, which are involved in the allergic reaction. In addition, all of the children had been bitten by ticks in the past.

Commins said he suspects that this meat allergy is underdiagnosed. Because the allergic reaction is delayed — occurring three to six hours after eating meat — people may not think to link the meat they ate earlier to their later reaction. This may be particularly true in children, who would typically need parents to make the link for them, Commins said.

In many cases, the meat allergy eventually goes away. But if patients experience more tick bites, they may see their allergy come back, Commins said.

The new study did not include a so-called food challenge test that could prove that meat was responsible for the children's allergies. During a food challenge, a patient eats a particular food and waits to see if there's a reaction. Commins said he did not feel comfortable performing a meat food challenge in children because sometimes the reactions to meat for those with allergies can be quite severe. But previous studies have shown that adults with antibodies against alpha-gal react to meat in a food challenge.

The American College of Allergy Asthma and Immunology agrees that there's a link between tick bites and the development of meat allergy, but notes that meat allergy is uncommon.

The researchers aren't sure why there's been an increase in this allergy in recent years. But an increase in awareness about the condition, or a change in the tick population, could play a role.

There's currently no treatment for the condition except to refrain from eating meat. The best way to prevent the allergy is to avoid tick bites, Commins said.

The study was presented last month at the American Academy of Allergy, Asthma & Immunology's annual meeting in San Antonio, Texas. It is set to be published in an upcoming issue of the journal Pediatrics.

The researchers have received funding for other work from ViraCor-IBT Laboratories, a company that provides diagnostic testing for allergies and other diseases.

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Same-sex marriage linked to longer lives

Since the advent of same-sex marriage in Denmark, married gay men and women have seen their death rates drop, a new study finds.

The research fits well with other studies that have linked health and marriage among opposite-sex couples. Men in same-sex couples now have lower mortality rates than unmarried or divorced men, with only men in opposite-sex marriages living longer.

"Among men in Denmark, it is more dangerous to be unmarried or divorced than to be married to another man," said study researcher Martin Frisch of the Statens Serum Institute in Copenhagen and the Center for Sexology Research of Aalborg University.

Tracking health

Denmark was the first nation in the world to legalize same-sex marriage, doing so in 1989. That length of time provides a unique advantage for researchers looking at the effects of legalized marriage, Frisch told LiveScience.

In the United States, same-sex marriage is now legal in the District of Columbia and nine states (Connecticut, Iowa, Maine, Maryland, Massachusetts, New Hampshire, New York, Vermont and Washington). The federal government does not recognize these unions.

Frisch and his colleagues used data from the country's Civil Registration System, which is used to issue citizens identification numbers (similar to Social Security numbers) and contains basic demographic information, including marital status and death dates. This database gave them information on 6.5 million Danes between 1982 and 2011.

During the study period, about 1.7 million of the people in the registry died, allowing the researchers to calculate mortality rates for the 29-year period. Controlling for education, income, city and population density, the researchers found that marriage made a difference.

Men and women in opposite-sex marriages had the lowest mortality rates of any other group in the study, including people who were widowed, divorced or unmarried. Female widows and divorcees were about 1.4 and 1.6 times more likely to die during the study period than those who were married to a man, respectively, and mortality rates for unmarried women rose slightly between 1982 and 2011, from 1.5 to 1.7 times more likely to die than married women.

Male widowers were 1.4 times more likely to die than men in opposite-sex marriages as of 2011, a slight increase from 1.2 in 1982. Men who were divorced also saw their chance of mortality go up over the study period, from 1.3 to 1.7 times more likely to die than married men. For unmarried men, the same numbers rose from 1.2 to 1.7 between 1982 and 2011.

Same-sex marriage and survival

Starting in 1989, when same-sex marriage was introduced, mortality rates among gays and lesbians who got married have declined. As of 2011, men in same-sex marriages were only 1.4 times more likely to die during the study period than men in opposite-sex marriages, a number lower than unmarried or divorced men. [5 Myths About Gay People Debunked]

Part of the mortality drop likely has to do with the development of antiretroviral therapies to treat HIV and AIDS, Fisch said. The syndrome affects gay men disproportionately, but drug therapies have been available since 1995 and 1996. As a result, gay men went from the group with the highest mortality rates to the group with the second-lowest, behind only men married to women.

Married lesbians also saw their mortality rates decline between 1989 and 2011, Frisch said, but not as dramatically.

"Since the year 2000, same-sex married Danish lesbians have had mortality rates that are almost 90 percent higher than opposite-sex women in Denmark," he said. Their mortality rates may even be increasing, he added.

Based on data about causes of death, the researchers think that an increased suicide risk among Danish lesbians explains a large part of their mortality lag. Married lesbians were more than six times more likely to commit suicide than married straight women. They were also at a 60 percent increased risk of death from cancer, for reasons not yet understood.

On one hand, the study reveals that mortality rates are not necessarily elevated in gay men, despite many studies finding disproportionate physical and mental health struggles among this group (often associated with social stigma). Marriage may protect against the societal challenges of being gay, or healthier gay men may be more likely to enter marriages.

On the other hand, Frisch said, the data suggest that men and women who are gay still struggle more than their straight counterparts. Both same-sex-married men and women had elevated suicide rates over straight-married couples, he said.

"It is important now to identify those factors that make more homosexuals than heterosexuals vulnerable to life's challenges to such an extent that suicide may appear to be the only way out," Frisch said.

The researchers report their findings online March 11 in the International Journal of Epidemiology.

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Thứ Sáu, 1 tháng 3, 2013

BPA exposure linked to kids' asthma risk

Children exposed to the chemical bisphenol A, or BPA, may be at an increased risk for asthma, a new study suggests.

During the study, kids who had greater exposure to BPA at ages 3, 5 and 7 were more likely to be diagnosed with asthma before age 12 than children who had less exposure.

BPA is found in some plastics, canned food containers and other food packaging, and most people have detectable levels of the chemical in their urine. Previous studies have linked BPA to a number of health conditions, including childhood obesity and behavior problems.

The new study is the first to report a link between BPA exposure during childhood and an increased risk for asthma. An earlier study found a link between BPA exposure in the womb during the second trimester of pregnancy, and an elevated risk of wheezing at age 3.

However, the new study only found an association, and cannot prove that BPA exposure plays any role in causing asthma.

To examine the link, Dr. Kathleen Donohue, an assistant professor of medicine at Columbia University, and colleagues analyzed urine samples from 568 pregnant women, and later, their children. Urine samples contain a breakdown product of BPA. While these samples do not provide a direct measure of BPA levels in the blood and tissue, researchers use them to gauge what a person may have been exposed to.

Physicians later diagnosed asthma based on the children's symptoms, their performance on a test of lung function, and their medical history. A separate question was used to assess whether or not the children experienced problems with wheezing.

The link between BPA exposure and asthma held even after the researchers took into account factors that could have affected the children's risk of breathing problems, such as exposure to secondhand smoke. However, it's still possible that factors not accounted for by the study, such as whether or not a child was breast-fed, could explain the link.

Interestingly, the study actually found that BPA exposure during the third trimester before birth was linked to a reduced risk of wheezing at age 5. Because there's no biological explanation for how BPA exposure could reduce a child's risk for asthma, the researchers speculate that the third trimester might not be the right window of time in which to assess a child's risk of asthma later in life. They note that it is the second trimester, not the third, that is a critical period for the development of airways and the immune system.

Strategies for lowering BPA exposure include eating less canned food, and choosing glass, porcelain or stainless steel containers to hold hot food and liquids, rather than plastic containers, according to the National Institute of Environmental Health Sciences.

The study will be published in the March issue of the Journal of Allergy and Clinical Immunology.

Another study published this month concluded that levels of BPA in the blood were too low to have biological effects on people, but other researchers argued that more research on this issue is needed.

View the original article here

Thứ Ba, 26 tháng 2, 2013

BIG BROTHER?US Linked to Censorship, Surveillance on Internet

Even the most open, democratic governments have sought laws and new forms of surveillance that many see as a new wave of censorship -- and that includes the United States.

The U.S. government asked Google for data on its users more than 31,000 times in 2012 alone, for example. And the government rarely obtained a search warrant first, Google recently revealed; in nearly all cases, the company ended up turning over at least some data.

Some argue that heightened surveillance, restrictions on Internet freedom and even censorship are necessary to protect intellectual property rights, prevent cyberespionage, fight child pornography, and protect national interests such as nuclear power plants from hackers. And here the U.S. is far from alone.

"A number of democratic states have considered or implemented various restrictions in response to the potential legal, economic, and security challenges raised by new media," notes the Freedom House report "Freedom on the Net 2012."

Anxiety over online theft and cyberattacks is not unwarranted. Virtually every major U.S. company and media outlet has been a victim. Google was attacked back in 2009. Facebook, Apple and Microsoft revealed this month that hackers had breeched their defenses. And The New York Times and Wall Street Journal have fought off Chinese hackers for months. Indeed, dozens of countries have their own online hacking groups -- so-called cyber or asymmetrical warfare divisions.

'A number of democratic states have considered or implemented various restrictions.'

- Freedom House report Freedom on the Net 2012

"It's been going on in China since at least at least May 2002," said Alan Paller, founder of the SANS Institute, an information security and training firm.

Consequently, lawmakers -- even President Obama in his State of the Union speech -- have been motivated to take steps to stem the hacking tide. However, the road to better security could also stifle free speech.

When the International Telecommunication Union (ITU) met in Dubai in December, some 89 member countries including Russia, China, Cuba, and Iran, supported a treaty that would give individual governments more control over the Internet's infrastructure.

Sensing a thinly veiled attempt to suppress dissent, 55 countries -- including Canada and the U.S. -- said no.

While the agreement has failed (for the time being), individual governments -- including Canada and the U.S. -- continue to introduce their own legislation to control what's online.

North of the border, for example, the Canadian government proposed Bill C-30, known as the Protecting Children from Internet Predators Act. Proponents claimed the measure was designed to combat the exploitation of children, but it required Internet service providers to create monitoring systems that would allow the police to intercept and track all online communications -- without a warrant. The public reaction was so fiercely opposed to Bill C-30 that Canadian authorities were forced to withdraw it this month.

On this side of the border, the U.S. government continues to conduct warrantless online searches. Thanks to outdated laws such as the Electronic Communications Privacy Act of 1986 and other regulations protecting copyrighted materials, U.S. authorities are increasingly looking at private online communications, often without any oversight by a judge.

Google says it has seen a 70 percent increase in requests from authorities for information about its users, information which includes private e-mails and search data. The biggest requester? The U.S. government, which sought information 8,438 times in the last six months of 2012. Google complied with those requests in roughly 88 percent of the cases.

While Google states it is against such broad government access to personal information -- dealing with such requests costs Google time and money -- where it stands on strict Internet freedoms is mutable.

Shortly before his State of the Union speech, President Obama signed an executive order designed to let federal government agencies share critical cyberthreat information with private companies to protect companies involved in supporting the nation's critical infrastructure.

“We know hackers steal people’s identities and infiltrate private e-mail," the President said in his speech. "We cannot look back years from now and wonder why we did nothing in the face of real threats to our security and our economy."

Even though the data shared by the government could include personal information, in this case companies have been in favor of the executive order. The reason: private firms don't have to in turn share data their data about their users with the government.

However, that may be about to change. As the President implied, Congress is working on reintroducing the Cyber Intelligence Sharing and Protection Act (CISPA). It would enable companies to divulge private information to government authorities if the companies perceived some form of "cyber threats." Any personal information -- Facebook jokes, Twitter tussles, errant Web searches -- could be handed over to a variety of government agencies if that information has anything to do with the potential vulnerability of a computer network.

"CISPA offers broad immunities to companies who choose to share data with government agencies," the Electronic Frontier Foundation's Mark M. Jaycox explained in a blog post. "It also creates avenues for companies to share data with any federal agencies, including military intelligence agencies like the National Security Agency."

While congress has yet to hammer out new, possibly more precise, language for a reintroduced CISPA bill, the powers it grants to both private companies and government authorities could end up making them partners in nationwide surveillance -- the same complaint often levied against countries like China.

Follow John R. Quain on Twitter @jqontech or find more tech coverage at J-Q.com.

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Thứ Năm, 21 tháng 2, 2013

Feds indict 4 over 2009 salmonella outbreak linked to Georgia peanut plant

ATLANTA – A federal grand jury indicted four employees of a peanut company linked to a 2009 salmonella outbreak that killed nine people and sickened hundreds.

The indictment was unsealed Wednesday in federal court in Georgia and charges four employees with Virginia-based Peanut Corp. of America. The charges include conspiracy, wire fraud, obstruction of justice and others related to contaminated or misbranded food.

Named in the indictment were company owner Stewart Parnell, his brother and company vice president Michael Parnell, Georgia plant manager Samuel Lightsey and Georgia plant quality assurance manager Mary Wilkerson.

The recall of Peanut Corp.'s peanut products was one of the largest in history. FDA inspectors found remarkably bad conditions inside Parnell's processing plant in Blakely, Ga., including mold and roaches.

The indictment accused the Parnells and Lightsey of conspiring to defraud customers and obtain money through false and fraudulent pretenses. Wilkerson was charged with obstruction of justice.

The U.S. attorney's office declined to comment until after a news conference later Thursday.

The indictment alleged the conspiracy lasted from about June 2003 through February 2009. The indictment said peanut products were shipped after it tested positive for salmonella, and the company failed to inform customers.

Stewart Parnell, who invoked the Fifth Amendment to avoid testifying before Congress in February 2009, once directed employees to "turn them loose" after samples of peanuts had tested positive for salmonella and then were cleared in a second test, according to e-mails uncovered at the time by congressional investigators.

The indictment cited emails sent between defendants talking about the contamination in the product.

A federal judge in 2010 approved a $12 million insurance settlement for more than 100 salmonella victims.

Even President Barack Obama expressed concern at the height of the product recalls, noting that his daughter Sasha eats peanut butter for lunch as often as three times a week.

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Thứ Tư, 20 tháng 2, 2013

Caffeine linked to low birth weight in babies

One cup of fresh coffee a day significantly increases the chances of giving birth to an underweight baby, a study has found.

The new findings from a large Scandinavian study suggest current guidelines on caffeine consumption during pregnancy may not go far enough.

A daily dose of between 200 and 300 milligrams of caffeine – roughly equivalent to one cup of fresh coffee or two cups of instant – increased the risk of a baby being small for gestational age (SGA) by up to 62 percent.

The association was independent of smoking, a major risk factor for low birth weight, which may be linked to caffeine intake.

Coffee, but not other sources of caffeine, was also associated with longer pregnancies.

The reason for this remains a mystery. It could be due to some aspect of behavior rather than the effects of any substance in coffee, according to the researchers.

Currently the World Health Organization recommends a caffeine consumption limit of 300 milligrams per day for pregnant women.

However, the new study shows that even 200 milligrams per day of caffeine can increase SGA risk. Writing in the online journal BMC Medicine, the researchers concluded: 'This association should be further investigated and recommendations might have to be re-evaluated.'

A baby is said to be small for gestational weight if it weighs about 4.4 pounds or less after a normal length pregnancy. Such babies can suffer complications at birth or long-term health problems, including impaired neurodevelopment.

Along with nutrients and oxygen, caffeine passes across the placental barrier, but is not easily inactivated by the developing fetus.

Click for more on this story from Sky News Australia.

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