Officials discuss health climate change
Tue, 03 Jul 2007 20:14:28 GMTBy MARGIE MASON, AP Medical Writer
KUALA LUMPUR, Malaysia - Officials from more than a dozen Asian countries met Tuesday in Malaysia to outline health problems their populations are facing in relation to a rise in global temperatures.
Officials discussed ways to work together to limit the fallout in a region expected to be hit hard by flooding, drought, heat waves, mosquito-borne diseases and waterborne illnesses.
The World Health Organization estimates climate change has already directly or indirectly killed more than 1 million people globally since 2000. More than half of those deaths have occurred in the Asia-Pacific area, the world's most populous region. Those figures do not include deaths linked to urban air pollution, which kills about 800,000 worldwide each year, according to WHO.
"We're not going to have a magic bullet to fix climate change in the next 50 years. We need to motivate an awful lot of people to change their behavior in a lot of different ways," said Kristie Ebi, of the WHO's Global Environmental Change unit, a lead author on the health chapter in a report by the Intergovernmental Panel on Climate Change, a U.N. network of 2,000 scientists.
Ebi said health officials are about a decade behind other sectors, such as water and agriculture, in taking a look at what climate change could mean and how to deal with it. She said countries seeing the effects firsthand are now starting to realize that any problems with air, water or food will directly affect people's health. The poorest countries in Asia and Africa are expected to suffer the most.
Scientists have predicted droughts will lower crop yields and raise malnutrition in some areas, dust storms and wildfires will boost respiratory illnesses, and flooding from severe storms will increase drowning, injury and disease such as diarrhea. Increasing temperatures could also lead to the growth of more harmful algae that can sicken people who eat shellfish and reef fish. People living in low-lying coastal areas will also face more storms, flooding and saltwater intrusion into fresh groundwater that is vital for drinking.
Singapore saw mean annual temperatures increase 2.7 degrees Fahrenheit between 1978 and 1998, while the number of dengue fever cases jumped 10-fold during the same period.
Malaria has recently reached Bhutan and new areas in Papua New Guinea for the first time. In the past, mosquitoes that spread the disease were unable to breed in the cooler climates there, but warmer temperatures have helped vector-borne diseases to flourish.
Melting of glaciers in the Himalayas have created about 20 lakes in Nepal that are in danger of overflowing their banks, which could create a torrent of water and debris capable of wiping out villages and farms below.
The four-day workshop in Malaysia lays the groundwork for a ministerial-level meeting on the topic next month in Bangkok, Thailand.
Study Twins form after embryo collapses
Tue, 03 Jul 2007 20:17:40 GMTBy MARIA CHENG, AP Medical Writer
LYON, France - Scientists proposed a new theory this week for how identical twins are formed as embryos, in a discovery that may improve a broad range of artificial reproduction techniques.
Using specialized computer software to take photos every two minutes of 33 embryos growing in a laboratory, Dr. Dianna Payne, a visiting research fellow at the Mio Fertility Clinic in Japan, and colleagues documented for the first time the early days of twin development.
The research was presented Monday at a meeting of the European Society for Human Reproduction and Embryology in Lyon, France.
Payne and colleagues found that identical twins are formed after an embryo essentially collapses, splitting the progenitor cells — those that contain the body's fundamental genetic material — in half. That leaves the same genetic material divided in two on opposite sides of the embryo. Eventually, two separate fetuses develop.
"This is very exciting because it explains the principle of how we get twins," said Dr. Soren Ziebe, an artificial reproduction expert at the University of Copenhagen, who was not connected to Payne's research.
"Until now, we have assumed that at some point when the embryo breaks out of its shell to adhere to the uterus, it somehow gets divided into two," Ziebe said. Payne's theory presents a plausible explanation of how that division occurs, according to Ziebe.
"This is an exciting paper because by watching the embryo growing continuously, it has given a new insight into the processes by which the embryo divides," said Dr. Alison Murdoch, a professor of reproductive medicine at Newcastle University's Fertility Centre. Murdoch was not connected to Payne's research.
While conducting the research, Payne also found a possible explanation for why in-vitro fertilization techniques are more likely to create twins. Only about three pairs of twins per thousand deliveries occur as a result of natural conception. But for IVF deliveries, there are nearly 21 pairs of twins for every thousand.
To date, scientists have been at a loss to explain the discrepancy. Payne suggests that the laboratory conditions in which embryos are grown — in solutions that attempt to reproduce the uterus environment — are different enough to somehow provoke the development of twins.
"There are a lot of very subtle effects in the body, like different gas concentrations, enzymes or salt solutions," said Payne. While scientists attempt to replicate an embryo's natural environment, they are still far off. "The difference between the lab conditions and what's present in the body is probably resulting in more twins," she said.
"We need to take careful account of this new information," Murdoch said, adding that growing embryos for longer periods in the laboratory may be adding to the likelihood of having twins.
Payne suggested that with more research, doctors could potentially devise a test to predict which embryos might be inclined to produce identical twins. Because carrying twins is more risky than carrying a single baby, experts think the success rates of artificial reproduction would increase if twins could be avoided.
In the photos from Payne's research, scientists were able to observe two distinct "inner cell masses" in the embryos that developed twins. Of the 26 embryos that developed enough for them to observe, two had these distinct internal cell masses that scientists think are characteristic of twins.
Experts think that Payne's discovery could be applied to a number of artificial reproduction techniques.
"If we can improve the laboratory conditions for embryos to minimize the development of twins, then we can optimize the conditions for all eggs and embryos in artificial reproduction," said Ziebe. "This research has the potential to help all IVF procedures."
Study Chocolate reduces blood pressure
Tue, 03 Jul 2007 20:12:41 GMTBy LINDSEY TANNER, AP Medical Writer
CHICAGO - Here's some good and bad news for chocoholics: Dark chocolate seems to lower blood pressure, but it requires an amount less than two Hershey's Kisses to do it, a small study suggests.
The new research from Germany adds to mounting evidence linking dark chocolate with health benefits, but it's the first to suggest that just a tiny amount may suffice.
Volunteers for the study ate just over 6 grams of dark chocolate daily for almost five months — one square from a German chocolate bar called Ritter Sport, equal to about 1 1/2 Hershey's Kisses. People who ate that amount ended up with lower blood pressure readings than those who ate white chocolate.
University of Cologne researcher Dr. Dirk Taubert, the study's lead author, said the blood pressure reductions with dark chocolate were small but still substantial enough to potentially reduce cardiovascular disease risks, although study volunteers weren't followed long enough to measure that effect.
The research involved just 44 people aged 56 through 73, but the results echo other small studies of cocoa-containing foods. Cocoa contains flavanols, plant-based compounds that also are credited with giving red wine its heart-healthy benefits.
One problem is chocolate bars containing cocoa tend to have lots of calories, so Taubert and his colleagues tested small amounts containing just 30 calories each.
The study appears in Wednesday's Journal of the American Medical Association. It was funded by University Hospital in Cologne.
The results are interesting but need to be duplicated in larger, more ethnically diverse populations, said Dr. Laura Svetkey, director of Duke University's Hypertension Center.
She stressed that the study results should not be viewed as license to gorge on chocolate.
"I would be as happy as the next person if I got to eat more chocolate," she said, but cautioned that weight gain from eating large amounts of dark chocolate would counteract any benefits on blood pressure.
Study participants were otherwise healthy and mostly normal-weight German adults with mild high blood pressure or pre-hypertension, which includes readings between 120 over 80 and 139 over 89.
Average blood pressure at the start was about 147 over 86.
Every day for 18 weeks, the volunteers were instructed to eat one-square portions of a 16-square Ritter Sport bar, or a similar portion of white chocolate. White chocolate doesn't contain cocoa.
Systolic blood pressure, the top number, fell an average of nearly three points and diastolic dropped almost two points in the dark chocolate group, compared with no change in blood pressure readings in the white chocolate group.
Tests suggested that steady exposure to dark chocolate prompted chemical changes that helped dilate blood vessels and regulate blood pressure, the researchers said.
Participants were told not to eat other cocoa-containing products and to continue regular eating habits and activity levels. They also kept food diaries so researchers could see if other foods might have influenced the results.
But, said Taubert, "It is very unlikely that other factors may explain the blood pressure reduction."
Dr. Lawrence Appel of Johns Hopkins School of Medicine said the most proven non-drug methods for lowering blood pressure are losing weight and eating less salt. Eating dark chocolate might help if combined with those two, he said.
For most people, "the lower your blood pressure, the better you are. So if you can get it lower from different strategies that's good for the long term," Appel said,
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On the Net:
JAMA: http://jama.ama-assn.org
Study Better equipment can cut illness
Tue, 03 Jul 2007 20:20:39 GMTBy STEVE HARTSOE, Associated Press Writer
RALEIGH, N.C. - Fewer children and workers at out-of-home day care centers would get sick if the centers had better equipment for changing diapers, washing hands and preparing food, according to a study.
Automatic faucets and foot-activated, rollout bins for diaper disposal can help reduce the spread of infectious diseases. But those and other upgrades are costly: roughly $10,000 per center, according to researchers at the University of North Carolina at Chapel Hill.
The report appeared in Monday's edition of Pediatrics, the journal of the American Academy of Pediatrics.
About 70 percent of U.S. children spend at least part of the day with caregivers other than their parents and with children who are not their siblings, according to the National Association for the Education of Young Children. Research shows children are more likely to get sick in those environments, the study said.
For the report, researchers monitored 23 pairs of child care centers in North Carolina, matched by size and license level. Half the centers received around $7,000 worth of equipment upgrades — which cost another $3,000 to install — while the other group used existing equipment. Both groups received sanitation and hygiene training.
The upgrades also featured cast polymer tabletops with impermeable, seamless surfaces for preparing food, changing diapers and washing hands. All the equipment was made by the Winterville, N.C.-based The Sabre Companies LLC.
After about seven months, both groups improved hygiene, but the group with higher-grade equipment fared better. For children, that group recorded less than one illness per 100 days compared with 1.58 illnesses at the day care centers using unchanged equipment, the study said.
Staff in these centers with new equipment were absent less than half as often as the other workers during the study period. Fewer sick workers can significantly improve a day care environment, researchers said.
William C. Walton III, president and chief executive of The Sabre Companies, said the equipment, which the company has made for about six years, is used in day care centers in Oklahoma, Illinois and other states. Between 80 and 100 centers use it in North Carolina.
While the results make sense, the roughly $10,000 cost for upgrading day care centers could make it too expensive for most to make such changes, said Dr. Karen Ytterberg, a pediatrician at the Mayo Clinic in Rochester, Minn., who reviewed the study.
Researchers said they hope the findings lead to low-interest loans through a foundation or other sources that can make the improvements more accessible to a greater number of child care centers.
The study was paid for by the North Carolina Department of Health and Human Services and the National Institute of Environmental Health Sciences.
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On the Net:
Pediatrics: http://pediatrics.aappublications.org/
The Sabre Companies: http://www.sabregrp.com/Hatteras/hatteras_collection.htm
Eye checks urged for signs of later heart disease
Tue, 03 Jul 2007 11:01:55 GMTBy Tan Ee Lyn
HONG KONG - A study in Australia has shown that changes occur in blood vessels in the eyes of heavier and obese children from as young as six, warning signs that might be linked to cardiovascular disease in later life.
Previously, these changes -- widening of veins and narrowing of arteries -- were only observed in the retinas of heavy teenagers and adults, and this is the first time that such troubling signs have been seen in children so young.
Writing in the International Journal of Obesity, the researchers called for extensive monitoring of these subtle blood vessel changes as they can be an early indication of risks such as hypertension and stroke when the children enter adulthood.
&;It was initially thought that the risk profile developed in adolescents and young adults, but suggests that these changes probably occur even at an early age,&; Paul Mitchell, a professor at the University of Sydney's Centre for Vision Research, said in a telephone interview.
&;It may be worthwhile examining children or adolescents for subtle retinal vessel size as these could be markers of a person's risks as they get older into adulthood.&;
The retina is a thin layer of neural cells that lines the back of the eyeball.
The study involved 1,740 six-year-olds from 34 schools in Sydney.
After accounting for differences such as sex, ethnicity, length of the eyeball, birth weight and mean blood pressure, the researchers found unique changes in minute blood vessels in the retinas of children who were over the mean weight.
The average diameter of their retinal veins was 2.1 microns larger than those of their lighter peers. However, the average diameter of retinal arteries in the heavy children was 2.2 microns narrower than other children.
Veins carry low-oxygen blood back to the heart, while arteries carry oxygenated blood from the heart.
&;The reason for widening of the veins may simply relate to a larger blood volume associated with a heavier child. It's harder to explain the effects on the retinal . It could be a reflex response in obese children, but that remains to be seen,&; Mitchell added.
It also remained to be seen if the changes to blood vessels were reversible.
&;In adult populations, we haven't reversibility so often. For the narrowing of arteries associated with elevated blood pressure, even when blood pressure is back to normal, the arteries don't seem to respond, but we don't know about the ,&; Mitchell said.
