By Maggie Fox, Health and Science Editor - Mon Dec 10, 5:15 PM PST
WASHINGTON (Reuters) - People who eat a lot of red meat and processed meats have a higher risk of several types of cancer, including lung cancer and colorectal cancer, U.S. researchers reported on Monday.
The work is the first big study to show a link between meat and lung cancer. It also shows that people who eat a lot of meat have a higher risk of liver and esophageal cancer and that men raise their risk of pancreatic cancer by eating red meat.
"A decrease in the consumption of red and processed meat could reduce the incidence of cancer at multiple sites," Dr. Amanda Cross and colleagues at the U.S. National Cancer Institute wrote in their report, published in the Public Library of Science journal PLoS Medicine.
The researchers studied 500,000 people aged 50 to 71 who took part in a diet and health study done in conjunction with the AARP, formerly the American Association for Retired Persons.
After eight years, 53,396 cases of cancer were diagnosed.
"Statistically significant elevated risks (ranging from 20 percent to 60 percent) were evident for esophageal, colorectal, liver, and lung cancer, comparing individuals in the highest with those in the lowest quintile of red meat intake," the researchers wrote.
The people in the top 20 percent of eating processed meat had a 20 percent higher risk of colorectal cancer -- mostly rectal cancer -- and a 16 percent higher risk for lung cancer.
"Furthermore, red meat intake was associated with an elevated risk for cancers of the esophagus and liver," the researchers wrote.
These differences held even when smoking was accounted for.
"Red meat intake was not associated with gastric or bladder cancer, leukemia, lymphoma, or melanoma," added the researchers, whose study is freely available on the Internet at http://medicine.plosjournals.org/perlserv/?request=get-document& doi=10.1371/journal.pmed.0040325.
Red meat was defined as all types of beef, pork and lamb. Processed meat included bacon, red meat sausage, poultry sausage, luncheon meats, cold cuts, ham and most types of hot dogs including turkey dogs.
Meats can cause cancer by several routes, the researchers noted. "For example, they are both sources of saturated fat and iron, which have independently been associated with carcinogenesis," the researchers wrote.
Meat is also a source of several chemicals known to cause DNA mutations, including N-nitroso compounds (NOCs), heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs).
Jeanine Genkinger of Georgetown University in Washington, D.C., and Anita Koushik of the University of Montreal said the findings fit in with other research.
"Meat consumption in relation to cancer risk has been reported in over a hundred epidemiological studies from many countries with diverse diets," they wrote in a commentary.
Tuesday, December 11, 2007
Monday, December 10, 2007
Study Shows Why the Flu Likes Winter
y GINA KOLATA
Published: December 5, 2007
Researchers in New York believe they have solved one of the great mysteries of the flu: Why does the infection spread primarily in the winter months?
Skip to next paragraph
Related
Times Health Guide: The Flu
The answer, they say, has to do with the virus itself. It is more stable and stays in the air longer when air is cold and dry, the exact conditions for much of the flu season.
“Influenza virus is more likely to be transmitted during winter on the way to the subway than in a warm room,” said Peter Palese, a flu researcher who is professor and chairman of the microbiology department at Mount Sinai School of Medicine in New York and the lead author of the flu study.
Dr. Palese published details of his findings in the Oct. 19 issue of PLoS Pathogens. The crucial hint that allowed him to do his study came from a paper published in the aftermath of the 1918 flu pandemic, when doctors were puzzling over why and how the virus had spread so quickly and been so deadly.
As long as flu has been recognized, people have asked, Why winter? The very name, “influenza,” is an Italian word that some historians proposed, originated in the mid-18th century as influenza di freddo, or “influence of the cold.”
Flu season in northern latitudes is from November to March, the coldest months. In southern latitudes, it is from May until September. In the tropics, there is not much flu at all and no real flu season.
There was no shortage of hypotheses. Some said flu came in winter because people are indoors; and children are in school, crowded together, getting the flu and passing it on to their families.
Others proposed a diminished immune response because people make less vitamin D or melatonin when days are shorter. Others pointed to the direction of air currents in the upper atmosphere. But many scientists were not convinced.
“We know one of the largest factors is kids in school — most of the major epidemics are traced to children,” said Dr. Jonathan McCullers, a flu researcher at St. Jude Children’s Research Hospital in Memphis. “But that still does not explain wintertime. We don’t see flu in September and October.”
As for the crowding argument, Dr. McCullers said, “That never made sense.” People work all year round and crowd into buses and subways and planes no matter what the season.
“We needed some actual data,” Dr. McCullers added.
But getting data was surprisingly difficult, Dr. Palese said.
The ideal study would expose people to the virus under different conditions and ask how likely they were to become infected. Such a study, Dr. Palese said, would not be permitted because there would be no benefit to the individuals.
There were no suitable test animals. Mice can be infected with the influenza virus but do not transmit it. Ferrets can be infected and transmit the virus, but they are somewhat large, they bite and they are expensive, so researchers would rather not work with them.
To his surprise, Dr. Palese stumbled upon a solution that appeared to be a good second best.
Reading a paper published in 1919 in the Journal of the American Medical Association on the flu epidemic at Camp Cody in New Mexico, he came upon a key passage: “It is interesting to note that very soon after the epidemic of influenza reached this camp, our laboratory guinea pigs began to die.” At first, the study’s authors wrote, they thought the animals had died from food poisoning. But, they continued, “a necropsy on a dead pig revealed unmistakable signs of pneumonia.”
Dr. Palese bought some guinea pigs and exposed them to the flu virus. Just as the paper suggested, they got the flu and spread it among themselves. So Dr. Palese and his colleagues began their experiments.
By varying air temperature and humidity in the guinea pigs’ quarters, they discovered that transmission was excellent at 41 degrees. It declined as the temperature rose until, by 86 degrees, the virus was not transmitted at all.
The virus was transmitted best at a low humidity, 20 percent, and not transmitted at all when the humidity reached 80 percent.
The animals also released viruses nearly two days longer at 41 degrees than at a typical room temperature of 68 degrees.
Flu viruses spread through the air, unlike cold viruses, Dr. Palese said, which primarily spread by direct contact when people touch surfaces that had been touched by someone with a cold or shake hands with someone who is infected, for example.
Flu viruses are more stable in cold air, and low humidity also helps the virus particles remain in the air. That is because the viruses float in the air in little respiratory droplets, Dr. Palese said. When the air is humid, those droplets pick up water, grow larger and fall to the ground.
But Dr. Palese does not suggest staying in a greenhouse all winter to avoid the flu. The best strategy, he says, is a flu shot.
It is unclear why infected animals released viruses for a longer time at lower temperatures. There was no difference in their immune response, but one possibility is that their upper airways are cooler, making the virus residing there more stable.
Flu researchers said they were delighted to get some solid data at last on flu seasonality.
“It was great work, and work that needed to be done,” said Dr. Terrence Tumpe, a senior microbiologist at the Centers for Disease Control and Prevention.
Dr. McCullers said he was pleased to see something convincing on the flu season question.
“It was a really interesting paper, the first really scientific approach, to answer a classic question that we’ve been debating for years and years,” he said.
As for Dr. Palese, he was glad he spotted the journal article that mentioned guinea pigs.
“Sometimes it pays to read the old literature,” he said.
Published: December 5, 2007
Researchers in New York believe they have solved one of the great mysteries of the flu: Why does the infection spread primarily in the winter months?
Skip to next paragraph
Related
Times Health Guide: The Flu
The answer, they say, has to do with the virus itself. It is more stable and stays in the air longer when air is cold and dry, the exact conditions for much of the flu season.
“Influenza virus is more likely to be transmitted during winter on the way to the subway than in a warm room,” said Peter Palese, a flu researcher who is professor and chairman of the microbiology department at Mount Sinai School of Medicine in New York and the lead author of the flu study.
Dr. Palese published details of his findings in the Oct. 19 issue of PLoS Pathogens. The crucial hint that allowed him to do his study came from a paper published in the aftermath of the 1918 flu pandemic, when doctors were puzzling over why and how the virus had spread so quickly and been so deadly.
As long as flu has been recognized, people have asked, Why winter? The very name, “influenza,” is an Italian word that some historians proposed, originated in the mid-18th century as influenza di freddo, or “influence of the cold.”
Flu season in northern latitudes is from November to March, the coldest months. In southern latitudes, it is from May until September. In the tropics, there is not much flu at all and no real flu season.
There was no shortage of hypotheses. Some said flu came in winter because people are indoors; and children are in school, crowded together, getting the flu and passing it on to their families.
Others proposed a diminished immune response because people make less vitamin D or melatonin when days are shorter. Others pointed to the direction of air currents in the upper atmosphere. But many scientists were not convinced.
“We know one of the largest factors is kids in school — most of the major epidemics are traced to children,” said Dr. Jonathan McCullers, a flu researcher at St. Jude Children’s Research Hospital in Memphis. “But that still does not explain wintertime. We don’t see flu in September and October.”
As for the crowding argument, Dr. McCullers said, “That never made sense.” People work all year round and crowd into buses and subways and planes no matter what the season.
“We needed some actual data,” Dr. McCullers added.
But getting data was surprisingly difficult, Dr. Palese said.
The ideal study would expose people to the virus under different conditions and ask how likely they were to become infected. Such a study, Dr. Palese said, would not be permitted because there would be no benefit to the individuals.
There were no suitable test animals. Mice can be infected with the influenza virus but do not transmit it. Ferrets can be infected and transmit the virus, but they are somewhat large, they bite and they are expensive, so researchers would rather not work with them.
To his surprise, Dr. Palese stumbled upon a solution that appeared to be a good second best.
Reading a paper published in 1919 in the Journal of the American Medical Association on the flu epidemic at Camp Cody in New Mexico, he came upon a key passage: “It is interesting to note that very soon after the epidemic of influenza reached this camp, our laboratory guinea pigs began to die.” At first, the study’s authors wrote, they thought the animals had died from food poisoning. But, they continued, “a necropsy on a dead pig revealed unmistakable signs of pneumonia.”
Dr. Palese bought some guinea pigs and exposed them to the flu virus. Just as the paper suggested, they got the flu and spread it among themselves. So Dr. Palese and his colleagues began their experiments.
By varying air temperature and humidity in the guinea pigs’ quarters, they discovered that transmission was excellent at 41 degrees. It declined as the temperature rose until, by 86 degrees, the virus was not transmitted at all.
The virus was transmitted best at a low humidity, 20 percent, and not transmitted at all when the humidity reached 80 percent.
The animals also released viruses nearly two days longer at 41 degrees than at a typical room temperature of 68 degrees.
Flu viruses spread through the air, unlike cold viruses, Dr. Palese said, which primarily spread by direct contact when people touch surfaces that had been touched by someone with a cold or shake hands with someone who is infected, for example.
Flu viruses are more stable in cold air, and low humidity also helps the virus particles remain in the air. That is because the viruses float in the air in little respiratory droplets, Dr. Palese said. When the air is humid, those droplets pick up water, grow larger and fall to the ground.
But Dr. Palese does not suggest staying in a greenhouse all winter to avoid the flu. The best strategy, he says, is a flu shot.
It is unclear why infected animals released viruses for a longer time at lower temperatures. There was no difference in their immune response, but one possibility is that their upper airways are cooler, making the virus residing there more stable.
Flu researchers said they were delighted to get some solid data at last on flu seasonality.
“It was great work, and work that needed to be done,” said Dr. Terrence Tumpe, a senior microbiologist at the Centers for Disease Control and Prevention.
Dr. McCullers said he was pleased to see something convincing on the flu season question.
“It was a really interesting paper, the first really scientific approach, to answer a classic question that we’ve been debating for years and years,” he said.
As for Dr. Palese, he was glad he spotted the journal article that mentioned guinea pigs.
“Sometimes it pays to read the old literature,” he said.
Wednesday, November 14, 2007
Breast-Feeding Cuts Food Allergy Risk
WEDNESDAY, Nov. 14 (HealthDay News) -- Breast-feeding in the first three months of life appears to help shield children from developing food allergies.
ADVERTISEMENT
That's just one of a number of findings on food allergies scheduled to be presented this week at the annual meeting of the American College of Allergy, Asthma and Immunology in Dallas.
Research has determined a possible role for food allergy prevention strategies in high-risk children, including maternal food avoidance in pregnancy, breast-feeding, maternal food avoidance while breast-feeding, use of hyper-allergenic formulas, delayed introduction of allergenic foods and probiotics, noted one expert.
"A review of 18 studies demonstrates a significant protective effect of exclusive breast-feeding for at least three months for children with high risk for atopy (genetic tendency to develop allergic diseases) against the development of atopic dermatitis and early childhood asthma-like symptoms," Dr. Robert Wood, international health director for pediatric allergy and immunology at Johns Hopkins School of Medicine, said in a prepared statement.
He offered a number of recommendations for children at high risk of allergic diseases:
* Women should avoid peanuts and tree nuts during pregnancy and while breast-feeding.
* Mothers should supplement breast-feeding with a hypoallergenic formula (extensively or partially hydrolyzed).
* Delay feeding these children solid foods until they're six months old.
* Delay introduction of milk and egg until age 1 and peanut and tree nuts until age 3.
* Start early intervention when signs of food allergy appear (secondary prevention).
In a planned presentation about allergies and dietary restrictions, another expert noted that a person may have an allergy to one member of a food family, but may be able to eat other members of the same food family.
For example, one study on nine common fish found cross-reactivity and allergenicity were highest among cod, salmon and pollack and lowest among halibut, flounder, tuna and mackerel. Another study on edible nuts found cross-reactivity was strong among walnut, pecan and hazelnut; moderate among cashew, pistachio, Brazil nut and almond; and extremely low between peanut and tree nuts.
"You may be allergic to a particular part of a food, but not to another part," Dr. Sami Bahna, chief of allergy and immunology at Louisiana State University in Shreveport, said in a prepared statement.
Another expert said doctors need to consider food allergy as a potential cause of gastrointestinal or dermatological symptoms in patients.
"The eosinophilic gastrointestinal disorders (EGID) which may affect the esophagus, stomach, colon and rectum are mostly chronic and recurrent disorders that adversely impact quality of life for patients and families," Dr. Amal Assa'ad, director of the Food Allergy & Eosinophilic Disorders Clinic at Cincinnati Children's Medical Center, said in a prepared statement.
"Patients with EGID have a high rate of sensitization to food and environmental allergens, and many of them have a high rate of clinical symptoms with various food ingestions. A subset of patients respond to removal of major food allergens from their diet," Assa'ad said.
"EGID management often requires multiple specialists, including the primary physician, allergy and immunology, gastroenterology, nutrition and psychology," she noted.
ADVERTISEMENT
That's just one of a number of findings on food allergies scheduled to be presented this week at the annual meeting of the American College of Allergy, Asthma and Immunology in Dallas.
Research has determined a possible role for food allergy prevention strategies in high-risk children, including maternal food avoidance in pregnancy, breast-feeding, maternal food avoidance while breast-feeding, use of hyper-allergenic formulas, delayed introduction of allergenic foods and probiotics, noted one expert.
"A review of 18 studies demonstrates a significant protective effect of exclusive breast-feeding for at least three months for children with high risk for atopy (genetic tendency to develop allergic diseases) against the development of atopic dermatitis and early childhood asthma-like symptoms," Dr. Robert Wood, international health director for pediatric allergy and immunology at Johns Hopkins School of Medicine, said in a prepared statement.
He offered a number of recommendations for children at high risk of allergic diseases:
* Women should avoid peanuts and tree nuts during pregnancy and while breast-feeding.
* Mothers should supplement breast-feeding with a hypoallergenic formula (extensively or partially hydrolyzed).
* Delay feeding these children solid foods until they're six months old.
* Delay introduction of milk and egg until age 1 and peanut and tree nuts until age 3.
* Start early intervention when signs of food allergy appear (secondary prevention).
In a planned presentation about allergies and dietary restrictions, another expert noted that a person may have an allergy to one member of a food family, but may be able to eat other members of the same food family.
For example, one study on nine common fish found cross-reactivity and allergenicity were highest among cod, salmon and pollack and lowest among halibut, flounder, tuna and mackerel. Another study on edible nuts found cross-reactivity was strong among walnut, pecan and hazelnut; moderate among cashew, pistachio, Brazil nut and almond; and extremely low between peanut and tree nuts.
"You may be allergic to a particular part of a food, but not to another part," Dr. Sami Bahna, chief of allergy and immunology at Louisiana State University in Shreveport, said in a prepared statement.
Another expert said doctors need to consider food allergy as a potential cause of gastrointestinal or dermatological symptoms in patients.
"The eosinophilic gastrointestinal disorders (EGID) which may affect the esophagus, stomach, colon and rectum are mostly chronic and recurrent disorders that adversely impact quality of life for patients and families," Dr. Amal Assa'ad, director of the Food Allergy & Eosinophilic Disorders Clinic at Cincinnati Children's Medical Center, said in a prepared statement.
"Patients with EGID have a high rate of sensitization to food and environmental allergens, and many of them have a high rate of clinical symptoms with various food ingestions. A subset of patients respond to removal of major food allergens from their diet," Assa'ad said.
"EGID management often requires multiple specialists, including the primary physician, allergy and immunology, gastroenterology, nutrition and psychology," she noted.
Monday, July 23, 2007
Study Links Diet Soft Drinks With Cardiac Risk
By Ed Edelson
HealthDay Reporter 1 hour, 31 minutes ago
MONDAY, July 23 (HealthDay News) -- Drinking more than one soda a day -- even if it's the sugar-free diet kind -- is associated with an increased incidence of metabolic syndrome, a cluster of risk factors linked to the development of diabetes and cardiovascular disease, a study finds.
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The link to diet soda found in the study was "striking" but not entirely a surprise, said Dr. Ramachandran Vasan, study senior author and professor of medicine at Boston University School of Medicine. There had been some hints of it in earlier studies, he said.
"But this is the first study to show the association in a prospective fashion and in a large population," Vasan said.
That population consisted of more than 6,000 participants in the Framingham Heart Study, which has been following residents of a Massachusetts town since 1948. When the soda portion of the study began, all participants were free of metabolic syndrome, a collection of risk factors including high blood pressure, elevated levels of the blood fats called triglycerides, low levels of the artery-protecting HDL cholesterol, high fasting blood sugar levels and excessive waist circumference. Metabolic syndrome is the presence of three or more of these risk factors.
Over the four years of the study, people who consumed more than one soft drink of any kind a day were 44 percent more likely to develop metabolic syndrome than those who didn't drink a soda a day.
The findings are published in the July 24 issue of the journal Circulation.
A variety of explanations, none proven, have been proposed for the link between diet soft drink consumption and metabolic syndrome, Vasan said. That association was evident even when the researchers accounted for other factors, such as levels of saturated fat and fiber in the diet, total calorie intake, smoking and physical activity.
One theory is that the high sweetness of all soft drinks makes a person more prone to eat sugary, fattening foods. Another is that the caramel content of soft drinks promotes metabolic changes that lead to insulin resistance. "These are hotly debated by nutritional experts," Vasan said.
Vasan, who noted that he is not a nutritional expert, said he leans toward the theory that "this is a marker of dietary behavior" -- that people who like to drink sweet soda also like to eat the kind of foods that cardiac nutritionists warn against.
"But we cannot infer causality," Vasan said, meaning there is no proof that soda itself is the villain. "We have an association. Maybe it is a causal one or maybe it is a marker of something else."
Carefully controlled animal studies might resolve the cause-and-effect issue, he said.
Dr. Elizabeth G. Nabel, director of the U.S. National Heart, Lung, and Blood Institute, which funds the Framingham Heart Study, said in a prepared statement: "Other studies have shown that the extra calories and sugar in soft drinks contribute to weight gain, and therefore heart disease risk. This study echoes those findings by extending the link to all soft drinks and the metabolic syndrome."
HealthDay Reporter 1 hour, 31 minutes ago
MONDAY, July 23 (HealthDay News) -- Drinking more than one soda a day -- even if it's the sugar-free diet kind -- is associated with an increased incidence of metabolic syndrome, a cluster of risk factors linked to the development of diabetes and cardiovascular disease, a study finds.
ADVERTISEMENT
The link to diet soda found in the study was "striking" but not entirely a surprise, said Dr. Ramachandran Vasan, study senior author and professor of medicine at Boston University School of Medicine. There had been some hints of it in earlier studies, he said.
"But this is the first study to show the association in a prospective fashion and in a large population," Vasan said.
That population consisted of more than 6,000 participants in the Framingham Heart Study, which has been following residents of a Massachusetts town since 1948. When the soda portion of the study began, all participants were free of metabolic syndrome, a collection of risk factors including high blood pressure, elevated levels of the blood fats called triglycerides, low levels of the artery-protecting HDL cholesterol, high fasting blood sugar levels and excessive waist circumference. Metabolic syndrome is the presence of three or more of these risk factors.
Over the four years of the study, people who consumed more than one soft drink of any kind a day were 44 percent more likely to develop metabolic syndrome than those who didn't drink a soda a day.
The findings are published in the July 24 issue of the journal Circulation.
A variety of explanations, none proven, have been proposed for the link between diet soft drink consumption and metabolic syndrome, Vasan said. That association was evident even when the researchers accounted for other factors, such as levels of saturated fat and fiber in the diet, total calorie intake, smoking and physical activity.
One theory is that the high sweetness of all soft drinks makes a person more prone to eat sugary, fattening foods. Another is that the caramel content of soft drinks promotes metabolic changes that lead to insulin resistance. "These are hotly debated by nutritional experts," Vasan said.
Vasan, who noted that he is not a nutritional expert, said he leans toward the theory that "this is a marker of dietary behavior" -- that people who like to drink sweet soda also like to eat the kind of foods that cardiac nutritionists warn against.
"But we cannot infer causality," Vasan said, meaning there is no proof that soda itself is the villain. "We have an association. Maybe it is a causal one or maybe it is a marker of something else."
Carefully controlled animal studies might resolve the cause-and-effect issue, he said.
Dr. Elizabeth G. Nabel, director of the U.S. National Heart, Lung, and Blood Institute, which funds the Framingham Heart Study, said in a prepared statement: "Other studies have shown that the extra calories and sugar in soft drinks contribute to weight gain, and therefore heart disease risk. This study echoes those findings by extending the link to all soft drinks and the metabolic syndrome."
Sunday, July 22, 2007
Plastic Hemoglobin May Help Save Trauma Victims, Soldiers
Dr Lance Twyman, professor of chemistry at Sheffield University has developed a synthetic form of hemoglobin that may save thousands of lives each year.
They say that the artificial blood is light to carry, does not need to be kept cool and can be kept for longer.
The new blood is made up of plastic molecules that have an iron atom at their core, like haemoglobin, that can carry oxygen through the body.
The scientists said the artificial blood could be cheap to produce and they were looking for extra funding to develop a final prototype that would be suitable for biological testing.
Dr Lance Twyman, of the university's Department of Chemistry, said: "We are very excited about the potential for this product and about the fact that this could save lives.
"Many people die from superficial wounds when they are trapped in an accident or are injured on the battlefield and can't get blood before they get to hospital.
"This product can be stored a lot more easily than blood, meaning large quantities could be carried easily by ambulances and the armed forces."
A sample of the artificial blood prototype will be on display at the Science Museum in London from 22 May as part of an exhibition about the history of plastics.
They say that the artificial blood is light to carry, does not need to be kept cool and can be kept for longer.
The new blood is made up of plastic molecules that have an iron atom at their core, like haemoglobin, that can carry oxygen through the body.
The scientists said the artificial blood could be cheap to produce and they were looking for extra funding to develop a final prototype that would be suitable for biological testing.
Dr Lance Twyman, of the university's Department of Chemistry, said: "We are very excited about the potential for this product and about the fact that this could save lives.
"Many people die from superficial wounds when they are trapped in an accident or are injured on the battlefield and can't get blood before they get to hospital.
"This product can be stored a lot more easily than blood, meaning large quantities could be carried easily by ambulances and the armed forces."
A sample of the artificial blood prototype will be on display at the Science Museum in London from 22 May as part of an exhibition about the history of plastics.
Wednesday, June 6, 2007
Teams mimic stem cells using skin cells
NEW YORK - In a leap forward for stem cell research, three independent teams of scientists reported Wednesday that they have produced the equivalent of embryonic stem cells in mice using skin cells without the controversial destruction of embryos.
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If the same could be done with human skin cells — a big if — the procedure could lead to breakthrough medical treatments without the contentious ethical and political debates surrounding the use of embryos.
Experts were impressed by the achievement.
"I think it's one of the most exciting things that has come out about embryonic stem cells, period," said researcher Dr. Asa Abeliovich of Columbia University in New York, who didn't participate in the work. "It's very convincing that it's real."
But he and others cautioned that it will take further study to see whether this scientific advance can be harnessed for creating new human therapies. For one thing, the procedure used to get the mouse skin cells to mimic embryonic stem cells wouldn't be suitable. And it's simply not known whether the mouse results can be reproduced with human cells.
"We have a long way to go," said John Gearhart of Johns Hopkins University, a stem cell researcher who also wasn't involved in the new work.
In any case, scientists said, the advance does not mean that research that involves getting stem cells from human embryos should now be abandoned. "We simply don't know which approach ... will work the best," said researcher Konrad Hochedlinger of the Harvard Stem Cell Institute, who led one of the three teams.
Embryonic stem cells are prized because they can develop into all types of tissue. So experts believe they might be used for transplant therapies in people who are paralyzed or have illnesses ranging from diabetes to Parkinson's disease.
To harvest human embryonic stem cells, embryos must be destroyed, an action many people oppose.
Scientists have long hoped to find a way to reprogram ordinary body cells to act like stem cells, avoiding the use of embryos altogether. The new mouse studies seem to have accomplished that. Past experiments seeking alternative routes to getting stem cells have generally involved tampering with an embryo or egg.
At a press conference Wednesday, Hochedlinger and a member of a second team said their work was not an attempt to evade the ethical objections to embryo destruction. Instead, they said, the goal was to learn how cell reprogramming works.
But in a telephone interview, a prominent critic of embryonic stem cell research welcomed the new work on ethical terms.
"This is what we were looking for people to explore because it may provide all the advantages of embryonic stem cells without the moral problem," said Richard Doerflinger, deputy director of pro-life activities for the U.S. Conference of Catholic Bishops. "So I'm very encouraged."
Hochedlinger and colleagues present their work in the inaugural issue of the journal Cell Stem Cell. (The first word in the journal's name refers to its publisher, Cell Press).
The other two teams reported their results Wednesday on the Web site of the journal Nature. Rudolf Jaenisch of the Whitehead Institute in Cambridge, Mass., is the senior author of one paper, and the work behind the other paper was led by Shinya Yamanaka of Kyoto University in Japan.
The new work builds on a landmark paper Yamanaka published last August. He found that by slipping four genes into mouse skin cells called fibroblasts, he could make the altered cells behave much like embryonic stem cells in lab tests.
But these so-called "iPS" cells still showed significant differences from embryonic stem cells. The three new papers report on creating iPS cells that proved virtually identical to stem cells in a variety of lab tests.
The technique used in the mouse studies could promote cancer in any patients getting therapy based on iPS cells, so researchers emphasized that a new approach that avoids that hazard would have to be developed.
Gearhart called that a major issue to be resolved. In addition, he said, scientists still must show that these cells can give rise to many cell types in the lab, as embryonic stem cells can.
And all this must be accomplished in human cells — a difficult task, he said, because introducing genes into human cells is a major challenge.
If the technique can be harnessed for people, the iPS cells and the tissue they develop into would provide a genetic match to the person who donated the skin cells. That would make them suitable for transplant to that person, theoretically without fear of rejection.
ADVERTISEMENT
If the same could be done with human skin cells — a big if — the procedure could lead to breakthrough medical treatments without the contentious ethical and political debates surrounding the use of embryos.
Experts were impressed by the achievement.
"I think it's one of the most exciting things that has come out about embryonic stem cells, period," said researcher Dr. Asa Abeliovich of Columbia University in New York, who didn't participate in the work. "It's very convincing that it's real."
But he and others cautioned that it will take further study to see whether this scientific advance can be harnessed for creating new human therapies. For one thing, the procedure used to get the mouse skin cells to mimic embryonic stem cells wouldn't be suitable. And it's simply not known whether the mouse results can be reproduced with human cells.
"We have a long way to go," said John Gearhart of Johns Hopkins University, a stem cell researcher who also wasn't involved in the new work.
In any case, scientists said, the advance does not mean that research that involves getting stem cells from human embryos should now be abandoned. "We simply don't know which approach ... will work the best," said researcher Konrad Hochedlinger of the Harvard Stem Cell Institute, who led one of the three teams.
Embryonic stem cells are prized because they can develop into all types of tissue. So experts believe they might be used for transplant therapies in people who are paralyzed or have illnesses ranging from diabetes to Parkinson's disease.
To harvest human embryonic stem cells, embryos must be destroyed, an action many people oppose.
Scientists have long hoped to find a way to reprogram ordinary body cells to act like stem cells, avoiding the use of embryos altogether. The new mouse studies seem to have accomplished that. Past experiments seeking alternative routes to getting stem cells have generally involved tampering with an embryo or egg.
At a press conference Wednesday, Hochedlinger and a member of a second team said their work was not an attempt to evade the ethical objections to embryo destruction. Instead, they said, the goal was to learn how cell reprogramming works.
But in a telephone interview, a prominent critic of embryonic stem cell research welcomed the new work on ethical terms.
"This is what we were looking for people to explore because it may provide all the advantages of embryonic stem cells without the moral problem," said Richard Doerflinger, deputy director of pro-life activities for the U.S. Conference of Catholic Bishops. "So I'm very encouraged."
Hochedlinger and colleagues present their work in the inaugural issue of the journal Cell Stem Cell. (The first word in the journal's name refers to its publisher, Cell Press).
The other two teams reported their results Wednesday on the Web site of the journal Nature. Rudolf Jaenisch of the Whitehead Institute in Cambridge, Mass., is the senior author of one paper, and the work behind the other paper was led by Shinya Yamanaka of Kyoto University in Japan.
The new work builds on a landmark paper Yamanaka published last August. He found that by slipping four genes into mouse skin cells called fibroblasts, he could make the altered cells behave much like embryonic stem cells in lab tests.
But these so-called "iPS" cells still showed significant differences from embryonic stem cells. The three new papers report on creating iPS cells that proved virtually identical to stem cells in a variety of lab tests.
The technique used in the mouse studies could promote cancer in any patients getting therapy based on iPS cells, so researchers emphasized that a new approach that avoids that hazard would have to be developed.
Gearhart called that a major issue to be resolved. In addition, he said, scientists still must show that these cells can give rise to many cell types in the lab, as embryonic stem cells can.
And all this must be accomplished in human cells — a difficult task, he said, because introducing genes into human cells is a major challenge.
If the technique can be harnessed for people, the iPS cells and the tissue they develop into would provide a genetic match to the person who donated the skin cells. That would make them suitable for transplant to that person, theoretically without fear of rejection.
Wednesday, April 11, 2007
No genetic link found for heart risk, study says
CHICAGO (Reuters) - Genetic testing failed to find any gene mutations that predict a higher risk of heart disease, a study released on Tuesday said.
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Scientists at Yale University worked up the genetic profiles of nearly 1,500 people to examine 85 genes that smaller, earlier studies suggested might confer susceptibility to heart problems.
More than half the patients had come to a hospital having suffered a heart attack or other acute symptoms, while the others had experienced no heart trouble.
Only one genetic variation showed even a modest association to heart problems in the study, which was published in the
Journal of the American Medical Association.
"We therefore conclude that our findings, in this large sample ... cannot support that this panel of gene variants contains bona fide (heart disease) risk factors," study author Dr. Thomas Morgan wrote. Morgan is now at Washington University in St. Louis.
A significant proportion of pregnant women opt for genetic testing to determine if the fetus will develop an array of potential ailments such as cystic fibrosis or a form of mental retardation.
Increasingly, genetic testing is also being performed later in life to detect if a person has a higher risk of contracting diseases such as Alzheimer's or inherited breast cancer.
The availability of genetic testing also raises complex ethical questions, such as who should know about a person's risk and what should be done about it.
"Our findings come at a critical juncture in complex disease genetics," Morgan wrote, adding that several clinics offer genetic tests for several of the gene mutations his study examined.
"However, our findings suggest that such clinical genetic testing is premature and underscore the importance of robust replication studies of reported associations prior to their application to clinical care," he added.
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Scientists at Yale University worked up the genetic profiles of nearly 1,500 people to examine 85 genes that smaller, earlier studies suggested might confer susceptibility to heart problems.
More than half the patients had come to a hospital having suffered a heart attack or other acute symptoms, while the others had experienced no heart trouble.
Only one genetic variation showed even a modest association to heart problems in the study, which was published in the
Journal of the American Medical Association.
"We therefore conclude that our findings, in this large sample ... cannot support that this panel of gene variants contains bona fide (heart disease) risk factors," study author Dr. Thomas Morgan wrote. Morgan is now at Washington University in St. Louis.
A significant proportion of pregnant women opt for genetic testing to determine if the fetus will develop an array of potential ailments such as cystic fibrosis or a form of mental retardation.
Increasingly, genetic testing is also being performed later in life to detect if a person has a higher risk of contracting diseases such as Alzheimer's or inherited breast cancer.
The availability of genetic testing also raises complex ethical questions, such as who should know about a person's risk and what should be done about it.
"Our findings come at a critical juncture in complex disease genetics," Morgan wrote, adding that several clinics offer genetic tests for several of the gene mutations his study examined.
"However, our findings suggest that such clinical genetic testing is premature and underscore the importance of robust replication studies of reported associations prior to their application to clinical care," he added.
Monday, April 9, 2007
Scottish Scientists Develop "Spray-On Computers" for Healthcare
Scottish ingenuity has graced the world with some of the world's greatest inventions. First there was the game of golf, which was quickly followed by the development of Scotch whiskey, and last but not least, spray-on computers. Yep, entirely self-powered, self-networking digital "specks" which will be capable of collecting volumes of data on patients.
Speckled computing - some of the most advanced computing technology in the world - is currently being researched and developed by a group of Scottish experts.
The individual appliances, or 'specks', will form networks that can be programmed like ordinary computers.
Spraying them directly onto a person creates the ability to carry out different tests at the same time, for example muscle movement and pulse rate. This allows a complete picture of the patient's condition to be built up quickly.
The computing innovation, being developed by scientists at Edinburgh, Glasgow, St Andrews and Strathclyde universities, will be displayed at the Edinburgh International Science Festival next Friday as part of a talk by Damal Arvind, leading speckled computing professor and director of the Scottish consortium.
Arvind said: "This is the new class of computing: devices which can sense and process the data they receive. They also have a radio so they can network and there's a battery in there as well, so they are entirely self-powered.
Speckled computing - some of the most advanced computing technology in the world - is currently being researched and developed by a group of Scottish experts.
The individual appliances, or 'specks', will form networks that can be programmed like ordinary computers.
Spraying them directly onto a person creates the ability to carry out different tests at the same time, for example muscle movement and pulse rate. This allows a complete picture of the patient's condition to be built up quickly.
The computing innovation, being developed by scientists at Edinburgh, Glasgow, St Andrews and Strathclyde universities, will be displayed at the Edinburgh International Science Festival next Friday as part of a talk by Damal Arvind, leading speckled computing professor and director of the Scottish consortium.
Arvind said: "This is the new class of computing: devices which can sense and process the data they receive. They also have a radio so they can network and there's a battery in there as well, so they are entirely self-powered.
Sunday, April 8, 2007
Self Pap Smears??
A New Frontier in Awkward: Do Your Own Pap-Smears
Sure, we here at Medgadget are big fans of patients doing self-exams. Self breast exams and self testicular exams are excellent ways for patients to take their health into their own hands (bad pun intended). But doing your own pap smear? Will the kit come w/ a speculum and an angled mirror? No...there's just nothing good that can come from this.
Women who forgo screening for cervical cancer may be more inclined to participate in such programs if they're provided with a kit to obtain cervical samples at home, Dutch investigators report.
It's estimated that 28 percent of women in the Netherlands do not participate in cervical screening programs. Dr. Chris J. L. M. Meijer from VU University Medical Center, Amsterdam, and colleagues wanted to see if such women would agree to testing if they could provide samples without going to a clinic.
As reported in the International Journal of Cancer, 2,546 women who had not undergone regular cervical screening were mailed a self-sample kit. It included a small brush for collecting a cervical specimen, a collection tube, easy-to-follow instructions and a padded envelope for returning the sample to the lab. There it would be tested for human papillomavirus (HPV), which is the cause of nearly all cases of cervical cancer.
The rate of high grade pre-cancer detected in the self-sampling responders (1.67 percent) was significantly higher than in the other group (0.97 percent).
"Importantly," the researchers say, the costs of detecting one such lesion via self-sampling "are in the same range as those calculated for conventional ... screening."
Furthermore, they calculate that if the strategy was extended to the entire Netherlands, self-sampling could result in the early detection of 1,085 extra pre-cancerous lesions, "leading to roughly 100 cervical cancers being prevented or detected earlier."
Hmmm...maybe we spoke too soon...apparently Dutch women are very comfortable taking their own cervical samples. As always, our female fans, we need your help on this one: Would ya', Could ya', Should ya'?
Sure, we here at Medgadget are big fans of patients doing self-exams. Self breast exams and self testicular exams are excellent ways for patients to take their health into their own hands (bad pun intended). But doing your own pap smear? Will the kit come w/ a speculum and an angled mirror? No...there's just nothing good that can come from this.
Women who forgo screening for cervical cancer may be more inclined to participate in such programs if they're provided with a kit to obtain cervical samples at home, Dutch investigators report.
It's estimated that 28 percent of women in the Netherlands do not participate in cervical screening programs. Dr. Chris J. L. M. Meijer from VU University Medical Center, Amsterdam, and colleagues wanted to see if such women would agree to testing if they could provide samples without going to a clinic.
As reported in the International Journal of Cancer, 2,546 women who had not undergone regular cervical screening were mailed a self-sample kit. It included a small brush for collecting a cervical specimen, a collection tube, easy-to-follow instructions and a padded envelope for returning the sample to the lab. There it would be tested for human papillomavirus (HPV), which is the cause of nearly all cases of cervical cancer.
The rate of high grade pre-cancer detected in the self-sampling responders (1.67 percent) was significantly higher than in the other group (0.97 percent).
"Importantly," the researchers say, the costs of detecting one such lesion via self-sampling "are in the same range as those calculated for conventional ... screening."
Furthermore, they calculate that if the strategy was extended to the entire Netherlands, self-sampling could result in the early detection of 1,085 extra pre-cancerous lesions, "leading to roughly 100 cervical cancers being prevented or detected earlier."
Hmmm...maybe we spoke too soon...apparently Dutch women are very comfortable taking their own cervical samples. As always, our female fans, we need your help on this one: Would ya', Could ya', Should ya'?
Wednesday, March 28, 2007
Novel Antimicrobial Peptide Discovered
he University of British Columbia is reporting the discovery of a new antimicrobial peptide by its researchers, in collaboration with Inimex Pharmaceuticals, a spin-off university company:
"Antibiotics are now under threat because of the explosion in antibiotic-resistant bacteria. A third of all deaths on this planet are the result of infection so there is an urgent need to create new therapies," says Robert Hancock, principal investigator and Canada Research Chair in Pathogenomics and Antimicrobials. "The beauty of this peptide is that it acts on the host to trigger a protective response and doesn't act on bacteria directly. That means it's unlikely bacteria will become resistant to it."
The team found that a peptide, or chain of amino acids, they have dubbed innate defense regulator peptide (IDR-1), can increase innate immunity without triggering harmful inflammation, and offer protection both before and after infection is present.
The discovery, in animal models, will be published March 25 in the journal Nature Biotechnology.
Researchers tested the peptide's effectiveness against Staphylococcus aureus including MRSA; a superbug called vancomycin-resistant Enterococcus (VRE); and Salmonella. In Staph and VRE infections, although bacteria were not completely eradicated, IDR-1 significantly reduced bacteria counts and mortality, when given either 24-48 hours before or four hours after infection began. In Salmonella, the peptide offered significant protection when administered prior to infection setting in.
Data showed that IDR-1 activates several signaling pathways to stimulate infection-clearing chemokines -- a chemical mediator that mobilizes immune response.
In addition, the peptide did not produce harmful inflammation and toxicity often seen when the immune system is stimulated and, in fact, actually reduced the potentially harmful septic response. Sepsis, a consequence of a ravaging inflammatory response associated with infection, kills as many as 200,000 annually.
"Antibiotics are now under threat because of the explosion in antibiotic-resistant bacteria. A third of all deaths on this planet are the result of infection so there is an urgent need to create new therapies," says Robert Hancock, principal investigator and Canada Research Chair in Pathogenomics and Antimicrobials. "The beauty of this peptide is that it acts on the host to trigger a protective response and doesn't act on bacteria directly. That means it's unlikely bacteria will become resistant to it."
The team found that a peptide, or chain of amino acids, they have dubbed innate defense regulator peptide (IDR-1), can increase innate immunity without triggering harmful inflammation, and offer protection both before and after infection is present.
The discovery, in animal models, will be published March 25 in the journal Nature Biotechnology.
Researchers tested the peptide's effectiveness against Staphylococcus aureus including MRSA; a superbug called vancomycin-resistant Enterococcus (VRE); and Salmonella. In Staph and VRE infections, although bacteria were not completely eradicated, IDR-1 significantly reduced bacteria counts and mortality, when given either 24-48 hours before or four hours after infection began. In Salmonella, the peptide offered significant protection when administered prior to infection setting in.
Data showed that IDR-1 activates several signaling pathways to stimulate infection-clearing chemokines -- a chemical mediator that mobilizes immune response.
In addition, the peptide did not produce harmful inflammation and toxicity often seen when the immune system is stimulated and, in fact, actually reduced the potentially harmful septic response. Sepsis, a consequence of a ravaging inflammatory response associated with infection, kills as many as 200,000 annually.
Thursday, March 22, 2007
Trends in Tuberculosis Incidence: MMWR
In 2006, a total of 13,767 tuberculosis (TB) cases (4.6 per 100,000 population) were reported in the United States, representing a 3.2% decline from the 2005 rate. This report summarizes provisional 2006 TB incidence data from the National TB Surveillance System and describes trends since 1993. The TB rate in 2006 was the lowest recorded since national reporting began in 1953, but the rate of decline has slowed since 2000. The average annual percentage decline in the TB incidence rate decreased from 7.3% per year during 1993--2000 (95% confidence interval [CI] = 6.9%--7.8%) to 3.8% during 2000--2006 (CI = 3.1%--4.5%). Foreign-born persons and racial/ethnic minority populations continue to be affected disproportionately by TB in the United States. In 2006, the TB rate among foreign-born persons in the United States was 9.5 times that of U.S.-born persons.* The TB rates among blacks, Asians, and Hispanics† were 8.4, 21.2, and 7.6 times higher than rates among whites, respectively. The slowing of the decline in the overall national TB rate and the inability to effectively address persistent disparities in TB rates between U.S.-born and foreign-born persons and between whites and racial/ethnic minority populations threaten progress toward the goal of eliminating TB in the United States. In 1989, CDC and the Advisory Committee for the Elimination of Tuberculosis issued a strategic plan for the elimination of TB, setting an interim target case rate of 3.5 per 100,000 population by 2000 and ultimately the elimination of TB (i.e., <1 case per 1 million population) in the United States by 2010 (1).
TB is a nationally notifiable disease. Health departments in the 50 states and District of Columbia (DC) electronically report to CDC any TB cases that meet the CDC and Council of State and Territorial Epidemiologists case definition.§ Reports include the patient's race, ethnicity (i.e., Hispanic or non-Hispanic), treatment information, and drug-susceptibility test results if available. For this analysis, CDC calculated national and state TB rates (2) and rates for foreign-born and U.S.-born persons (3) and racial/ethnic populations (4) by using current U.S. census population estimates for the years 1993 through 2006.
In 2006, TB incidence rates in the 51 reporting areas ranged from 0.8 (Wyoming) to 12.6 (DC) cases per 100,000 population (median: 3.4 cases). Thirty states had lower rates in 2006 than 2005; 20 states and DC had higher rates (Table 1). In 2006, for the second consecutive year and the second time since national reporting began, approximately half of states (26 of 50) had TB rates of <3.5 per 100,000 (Figure 1); however, 11 of those 26 states had higher rates of TB in 2006 than in 2005. Seven states (California, Florida, Georgia, Illinois, New Jersey, New York, and Texas) reported more than 500 cases each for 2006; combined, these seven states accounted for 60% (8,259) of all TB cases.
Among U.S.-born persons, the number and rate of TB cases continued to decline in 2006. The U.S.-born TB rate was 2.3 per 100,000 population (5,924 or 43.3% of all cases with known origin of birth), representing a 7.0% decline in rate since 2005 and a 68.6% decline since 1993 (Figure 2).
Among foreign-born persons, the number of TB cases increased in 2006, but the rate decreased. The foreign-born TB rate in 2006 was 21.9 per 100,000 population, representing a 0.5% decline in rate since 2006 and a 35.8% decline since 1993. As the rate of decline in TB cases among foreign-born persons lagged behind the decline in TB cases among U.S.-born persons, the foreign-born to U.S.-born rate ratio increased 7.0%, from 8.9 in 2005 to 9.5 in 2006. In 2006, approximately half (55.6%) of TB cases among foreign-born persons were reported in persons from five countries: Mexico (1,912), the Philippines (856), Vietnam (630), India (540), and China (376).
In 2006, for the third consecutive year, more TB cases were reported among Hispanics than any other racial/ethnic population. Among persons with TB whose country of birth was known, 95.6% (3,126 of 3,269) of Asians, 74.7% (3,024 of 4,050) of Hispanics, 29.9% (1,110 of 3,712) of blacks, and 17.8% (427 of 2,404) of whites were foreign born. From 2005 to 2006, TB rates declined for all racial/ethnic minorities except American Indians/Alaska Natives and Native Hawaiians or Other Pacific Islanders¶ (Table 2).
Human immunodeficiency virus (HIV) contributes to the TB pandemic because immune suppression increases the likelihood of rapid progression from TB infection to TB disease. From 2005 to 2006, among TB cases with HIV status reported,** the percentage of TB cases with HIV infection decreased 4.4% (from 13.0% to 12.4%), but the percentage of TB cases with unknown HIV status increased 10.3% (from 28.7% to 31.7%).†† The decline in the percentage of TB cases with HIV infection might reflect incomplete reporting of HIV test results attributed to a lack of HIV testing or HIV reporting.
A total of 124 cases of multidrug-resistant TB (MDR TB)§§ were reported in 2005, the most recent year for which complete drug-susceptibility data are available.¶¶ The proportion of MDR-TB cases remained constant at 1.2% from 2004 (129 of 10,846 TB cases) to 2005 (124 of 10,662). In 2005, MDR TB continued to disproportionately affect foreign-born persons, who accounted for 101 (81.5%) of 124 MDR-TB cases.
The recommended length of drug therapy for most types of TB is 6--9 months. In 2003, the latest year for which treatment data are complete, 82.7% of patients for whom <1 year of treatment was indicated completed therapy within 1 year, below the Healthy People 2010 target of 90% (objective 14-12).
TB is a nationally notifiable disease. Health departments in the 50 states and District of Columbia (DC) electronically report to CDC any TB cases that meet the CDC and Council of State and Territorial Epidemiologists case definition.§ Reports include the patient's race, ethnicity (i.e., Hispanic or non-Hispanic), treatment information, and drug-susceptibility test results if available. For this analysis, CDC calculated national and state TB rates (2) and rates for foreign-born and U.S.-born persons (3) and racial/ethnic populations (4) by using current U.S. census population estimates for the years 1993 through 2006.
In 2006, TB incidence rates in the 51 reporting areas ranged from 0.8 (Wyoming) to 12.6 (DC) cases per 100,000 population (median: 3.4 cases). Thirty states had lower rates in 2006 than 2005; 20 states and DC had higher rates (Table 1). In 2006, for the second consecutive year and the second time since national reporting began, approximately half of states (26 of 50) had TB rates of <3.5 per 100,000 (Figure 1); however, 11 of those 26 states had higher rates of TB in 2006 than in 2005. Seven states (California, Florida, Georgia, Illinois, New Jersey, New York, and Texas) reported more than 500 cases each for 2006; combined, these seven states accounted for 60% (8,259) of all TB cases.
Among U.S.-born persons, the number and rate of TB cases continued to decline in 2006. The U.S.-born TB rate was 2.3 per 100,000 population (5,924 or 43.3% of all cases with known origin of birth), representing a 7.0% decline in rate since 2005 and a 68.6% decline since 1993 (Figure 2).
Among foreign-born persons, the number of TB cases increased in 2006, but the rate decreased. The foreign-born TB rate in 2006 was 21.9 per 100,000 population, representing a 0.5% decline in rate since 2006 and a 35.8% decline since 1993. As the rate of decline in TB cases among foreign-born persons lagged behind the decline in TB cases among U.S.-born persons, the foreign-born to U.S.-born rate ratio increased 7.0%, from 8.9 in 2005 to 9.5 in 2006. In 2006, approximately half (55.6%) of TB cases among foreign-born persons were reported in persons from five countries: Mexico (1,912), the Philippines (856), Vietnam (630), India (540), and China (376).
In 2006, for the third consecutive year, more TB cases were reported among Hispanics than any other racial/ethnic population. Among persons with TB whose country of birth was known, 95.6% (3,126 of 3,269) of Asians, 74.7% (3,024 of 4,050) of Hispanics, 29.9% (1,110 of 3,712) of blacks, and 17.8% (427 of 2,404) of whites were foreign born. From 2005 to 2006, TB rates declined for all racial/ethnic minorities except American Indians/Alaska Natives and Native Hawaiians or Other Pacific Islanders¶ (Table 2).
Human immunodeficiency virus (HIV) contributes to the TB pandemic because immune suppression increases the likelihood of rapid progression from TB infection to TB disease. From 2005 to 2006, among TB cases with HIV status reported,** the percentage of TB cases with HIV infection decreased 4.4% (from 13.0% to 12.4%), but the percentage of TB cases with unknown HIV status increased 10.3% (from 28.7% to 31.7%).†† The decline in the percentage of TB cases with HIV infection might reflect incomplete reporting of HIV test results attributed to a lack of HIV testing or HIV reporting.
A total of 124 cases of multidrug-resistant TB (MDR TB)§§ were reported in 2005, the most recent year for which complete drug-susceptibility data are available.¶¶ The proportion of MDR-TB cases remained constant at 1.2% from 2004 (129 of 10,846 TB cases) to 2005 (124 of 10,662). In 2005, MDR TB continued to disproportionately affect foreign-born persons, who accounted for 101 (81.5%) of 124 MDR-TB cases.
The recommended length of drug therapy for most types of TB is 6--9 months. In 2003, the latest year for which treatment data are complete, 82.7% of patients for whom <1 year of treatment was indicated completed therapy within 1 year, below the Healthy People 2010 target of 90% (objective 14-12).
Tuesday, March 13, 2007
Time Travel
Well, I actually can't believe that researchers have spent time and money researching time travel. And, after all this time, the researchers say that time travel can't be done.
As if I needed a scientist to tell me that time travel can't be done.
This just iterates the old saying or rather definition of a doctor
A doctor is someone who know more and more about less and less until he knows everything about nothing
CJ
As if I needed a scientist to tell me that time travel can't be done.
This just iterates the old saying or rather definition of a doctor
A doctor is someone who know more and more about less and less until he knows everything about nothing
CJ
You Can't Travel Back in Time, Scientists Say
The urge to hug a departed loved one again or prevent atrocities are among the compelling reasons that keep the notion of time travel alive in the minds of many.
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While the idea makes for great fiction, some scientists now say traveling to the past is impossible.
There are a handful of scenarios that theorists have suggested for how one might travel to the past, said Brian Greene, author of the bestseller, “The Elegant Universe” and a physicist at Columbia University.“And almost all of them, if you look at them closely, brush up right at the edge of physics as we understand it. Most of us think that almost all of them can be ruled out.”
The fourth dimension
In physics, time is described as a dimension much like length, width, and height. When you travel from your house to the grocery store, you’re traveling through a direction in space, making headway in all the spatial dimensions—length, width and height. But you’re also traveling forward in time, the fourth dimension.
“Space and time are tangled together in a sort of a four-dimensional fabric called space-time,” said Charles Liu, an astrophysicist with the City University of New York, College of Staten Island and co-author of the book “One Universe: At Home In The Cosmos.”
Space-time, Liu explains, can be thought of as a piece of spandex with four dimensions. “When something that has mass—you and I, an object, a planet, or any star—sits in that piece of four-dimensional spandex, it causes it to create a dimple,” he said. “That dimple is a manifestation of space-time bending to accommodate this mass.”
The bending of space-time causes objects to move on a curved path and that curvature of space is what we know as gravity.
Mathematically one can go backwards or forwards in the three spatial dimensions. But time doesn’t share this multi-directional freedom.
“In this four-dimensional space-time, you’re only able to move forward in time,” Liu told LiveScience.
Tunneling to the past
A handful of proposals exist for time travel. The most developed of these approaches involves a wormhole—a hypothetical tunnel connecting two regions of space-time. The regions bridged could be two completely different universes or two parts of one universe. Matter can travel through either mouth of the wormhole to reach a destination on the other side.
“Wormholes are the future, wormholes are the past,” said Michio Kaku, author of “Hyperspace” and “Parallel Worlds” and a physicist at the City University of New York. “But we have to be very careful. The gasoline necessary to energize a time machine is far beyond anything that we can assemble with today’s technology.”
To punch a hole into the fabric of space-time, Kaku explained, would require the energy of a star or negative energy, an exotic entity with an energy of less than nothing.
Greene, an expert on string theory—which views matter in a minimum of 10 dimensions and tries to bridge the gap between particle physics and nature's fundamental forces, questioned this scenario.
“Many people who study the subject doubt that that approach has any chance of working,” Greene said in an interview . “But the basic idea if you’re very, very optimistic is that if you fiddle with the wormhole openings, you can make it not only a shortcut from a point in space to another point in space, but a shortcut from one moment in time to another moment in time.”
* Video: How to Time Travel!
Cosmic strings
Another popular theory for potential time travelers involves something called cosmic strings—narrow tubes of energy stretched across the entire length of the ever-expanding universe. These skinny regions, leftover from the early cosmos, are predicted to contain huge amounts of mass and therefore could warp the space-time around them.
Cosmic strings are either infinite or they’re in loops, with no ends, said J. Richard Gott, author of “Time Travel in Einstein's Universe” and an astrophysicist at Princeton University. “So they are either like spaghetti or SpaghettiO’s.”
The approach of two such strings parallel to each other, said Gott, will bend space-time so vigorously and in such a particular configuration that might make time travel possible, in theory.
“This is a project that a super civilization might attempt,” Gott told LiveScience. “It’s far beyond what we can do. We’re a civilization that’s not even controlling the energy resources of our planet.”
Impossible, for now
Mathematically, you can certainly say something is traveling to the past, Liu said. “But it is not possible for you and me to travel backward in time,” he said.
However, some scientists believe that traveling to the past is, in fact, theoretically possible, though impractical.
Maybe if there were a theory of everything, one could solve all of Einstein’s equations through a wormhole, and see whether time travel is really possible, Kaku said. “But that would require a technology far more advanced than anything we can muster," he said. "Don’t expect any young inventor to announce tomorrow in a press release that he or she has invented a time machine in their basement.”
For now, the only definitive part of travel in the fourth dimension is that we’re stepping further into the future with each passing moment. So for those hoping to see Earth a million years from now, scientists have good news.
“If you want to know what the Earth is like one million years from now, I’ll tell you how to do that,” said Greene, a consultant for “Déjà Vu,” a recent movie that dealt with time travel. “Build a spaceship. Go near the speed of light for a length of time—that I could calculate. Come back to Earth, and when you step out of your ship you will have aged perhaps one year while the Earth would have aged one million years. You would have traveled to Earth’s future.”
More about Time Travel
ADVERTISEMENT
While the idea makes for great fiction, some scientists now say traveling to the past is impossible.
There are a handful of scenarios that theorists have suggested for how one might travel to the past, said Brian Greene, author of the bestseller, “The Elegant Universe” and a physicist at Columbia University.“And almost all of them, if you look at them closely, brush up right at the edge of physics as we understand it. Most of us think that almost all of them can be ruled out.”
The fourth dimension
In physics, time is described as a dimension much like length, width, and height. When you travel from your house to the grocery store, you’re traveling through a direction in space, making headway in all the spatial dimensions—length, width and height. But you’re also traveling forward in time, the fourth dimension.
“Space and time are tangled together in a sort of a four-dimensional fabric called space-time,” said Charles Liu, an astrophysicist with the City University of New York, College of Staten Island and co-author of the book “One Universe: At Home In The Cosmos.”
Space-time, Liu explains, can be thought of as a piece of spandex with four dimensions. “When something that has mass—you and I, an object, a planet, or any star—sits in that piece of four-dimensional spandex, it causes it to create a dimple,” he said. “That dimple is a manifestation of space-time bending to accommodate this mass.”
The bending of space-time causes objects to move on a curved path and that curvature of space is what we know as gravity.
Mathematically one can go backwards or forwards in the three spatial dimensions. But time doesn’t share this multi-directional freedom.
“In this four-dimensional space-time, you’re only able to move forward in time,” Liu told LiveScience.
Tunneling to the past
A handful of proposals exist for time travel. The most developed of these approaches involves a wormhole—a hypothetical tunnel connecting two regions of space-time. The regions bridged could be two completely different universes or two parts of one universe. Matter can travel through either mouth of the wormhole to reach a destination on the other side.
“Wormholes are the future, wormholes are the past,” said Michio Kaku, author of “Hyperspace” and “Parallel Worlds” and a physicist at the City University of New York. “But we have to be very careful. The gasoline necessary to energize a time machine is far beyond anything that we can assemble with today’s technology.”
To punch a hole into the fabric of space-time, Kaku explained, would require the energy of a star or negative energy, an exotic entity with an energy of less than nothing.
Greene, an expert on string theory—which views matter in a minimum of 10 dimensions and tries to bridge the gap between particle physics and nature's fundamental forces, questioned this scenario.
“Many people who study the subject doubt that that approach has any chance of working,” Greene said in an interview . “But the basic idea if you’re very, very optimistic is that if you fiddle with the wormhole openings, you can make it not only a shortcut from a point in space to another point in space, but a shortcut from one moment in time to another moment in time.”
* Video: How to Time Travel!
Cosmic strings
Another popular theory for potential time travelers involves something called cosmic strings—narrow tubes of energy stretched across the entire length of the ever-expanding universe. These skinny regions, leftover from the early cosmos, are predicted to contain huge amounts of mass and therefore could warp the space-time around them.
Cosmic strings are either infinite or they’re in loops, with no ends, said J. Richard Gott, author of “Time Travel in Einstein's Universe” and an astrophysicist at Princeton University. “So they are either like spaghetti or SpaghettiO’s.”
The approach of two such strings parallel to each other, said Gott, will bend space-time so vigorously and in such a particular configuration that might make time travel possible, in theory.
“This is a project that a super civilization might attempt,” Gott told LiveScience. “It’s far beyond what we can do. We’re a civilization that’s not even controlling the energy resources of our planet.”
Impossible, for now
Mathematically, you can certainly say something is traveling to the past, Liu said. “But it is not possible for you and me to travel backward in time,” he said.
However, some scientists believe that traveling to the past is, in fact, theoretically possible, though impractical.
Maybe if there were a theory of everything, one could solve all of Einstein’s equations through a wormhole, and see whether time travel is really possible, Kaku said. “But that would require a technology far more advanced than anything we can muster," he said. "Don’t expect any young inventor to announce tomorrow in a press release that he or she has invented a time machine in their basement.”
For now, the only definitive part of travel in the fourth dimension is that we’re stepping further into the future with each passing moment. So for those hoping to see Earth a million years from now, scientists have good news.
“If you want to know what the Earth is like one million years from now, I’ll tell you how to do that,” said Greene, a consultant for “Déjà Vu,” a recent movie that dealt with time travel. “Build a spaceship. Go near the speed of light for a length of time—that I could calculate. Come back to Earth, and when you step out of your ship you will have aged perhaps one year while the Earth would have aged one million years. You would have traveled to Earth’s future.”
More about Time Travel
Sunday, February 18, 2007
House was right: Everybody lies
Lying to doctor can mean health risks
CHICAGO - There's an open secret in medicine: Patients lie.
understate how much they drink and overstate how much they exercise. They feign symptoms to get appointments quicker and ask doctors to hide the truth from insurance companies.
"Doctors have a rule of thumb. Whatever the patient says they're drinking, multiply it by three," said Dr. Bruce Rowe, a family doctor in suburban Milwaukee. "If they say two drinks a day, assume they have six."
Hippocrates, the father of medicine, is said to have warned his students around 400 B.C. that patients often dissemble when they say they've taken their medicine. TV's fictional Dr. Gregory House repeats the same message to his crack team: "Everybody lies."
But lying can lead to expensive diagnostic procedures and unneeded referrals to specialists. It also can have disastrous results.
"I definitely learned my lesson. I could have ended up in a coma," said Michael Levine, a 28-year-old financial adviser in Los Angeles, who lied to a specialist he saw for a wrist injury. Misguided pride, he said, kept him from mentioning the Xanax he was taking for anxiety. He didn't think the doctor needed to know.
"He wasn't my regular doctor. He was treating my wrist," Levine explained.
The doctor prescribed the pain reliever Vicodin and Levine took it on top of Xanax. The next few days vanished in a cloud of grogginess. Levine slept through ringing phones and alarms and woke up exhausted. His wrist pain was easing, but he could barely function. Eventually, he stopped the Vicodin, returned to the doctor and, under questioning, confessed.
"The doctor said, 'Why didn't you tell me? I never would have prescribed you that,'" said Levine, who now realizes how easily he could have overdosed and died. "For the future, I will always 'fess up."
Why do patients lie? The examination room itself is an environment that discourages honesty, said Los Angeles psychiatrist Dr. Charles Sophy.
"You're naked in a gown and you have a guy standing there clothed, with a coat on and there's all sorts of things in his pocket. And you're sitting there, basically naked ... that makes it hard to come clean," Sophy said. On top of that, the doctor may be rushed.
Researchers say patients often lie to save face. They want to be "good patients" in their doctors' eyes. But that's a misguided and risky practice. For example, a woman who doesn't want to admit she smokes and then is prescribed birth control pills is at greater risk for blood clots.
Some researchers estimate more than half of patients tell their doctors they're taking their medicine exactly as prescribed when they're not. In reality, they don't like the side effects, can't afford the pills or didn't understand the instructions.
A study by researchers at Johns Hopkins School of Medicine found a big gap between what patients said and what they did. Researchers looked at how patients with breathing problems used an inhaler equipped with a device that recorded the date and time of use and compared that with what the patients said.
Seventy-three percent of patients reported using the inhaler on average three times a day, but only 15 percent actually were using it that often. And 14 percent apparently deliberately emptied their inhalers before their appointments to make it look as if they were good patients.
Some doctors are seeking approaches that encourage more honesty. Dr. Zach Rosen, medical director of New York's Montefiore Family Health Center, asks his patients a series of questions to determine whether they're taking their medicine.
"I ask, 'What medications are you taking?' At first, I just want the names," he said. "They say, 'I'm taking X, Y or Z.' Then I'll say, 'That's great. How often are you taking that medication?' ... Then I'll say, 'Are you experiencing any problem in taking your medications?'"
Asking several questions takes more time. But the approach elicits better, more honest responses than a single question, Rosen believes.
Doctors also should avoid phrases that sound judgmental, said Nate Rickles, an assistant professor of pharmacy at Northeastern University. There's a big difference between "Why aren't you taking the medication as prescribed?" and "A number of my patients don't take their medication as prescribed and they do it for a variety of reasons. What do you think might be going on with you?"
When alcoholics seek detox treatment from Dr. Akikur Mohammad, an addiction specialist at the University of Southern California School of Medicine, they must tell him exactly how much they've been drinking so he can give them the right dose of medication to treat withdrawal.
"I tell them, 'You can lie to your friend, you can lie to your family members, but you came here for help and your report will determine the treatment plan. If I undermedicate you, you may have seizures and die,'" Mohammad said. Despite the warnings, patients still sometimes mislead him, he said.
Cyndi Smith, a 45-year-old Weight Watchers leader in suburban Chicago, admits her own lying past when it came to questions about her exercise and eating habits. She says she lied because she was fooling herself.
"You convince yourself of certain things and it becomes true, when in reality it's not," she said. If her doctor had questioned her more thoroughly, she says she might have told the truth.
"I think doctors could be a little more point-blank," she said. "And we need to be a little more honest."
Saturday, February 17, 2007
Human Compassion Surprisingly Limited, Study Finds
AN FRANCISCO—While a person's accidental death reported on the evening news can bring viewers to tears, mass killings reported as statistics fail to tickle human emotions, a new study finds.
The Internet and other modern communications bring atrocities such as killings in Darfur, Sudan into homes and office cubicles. But knowledge of these events fails to motivate most to take action, said Paul Slovic, a University of Oregon researcher.
People typically react very strongly to one death but their emotions fade as the number of victims increase, Slovic reported here yesterday at the annual meeting of the American Association for the Advancement of Science.
"We go all out to save a single identified victim, be it a person or an animal, but as the numbers increase, we level off," Slovic said. "We don't feel any different to say 88 people dying than we do to 87. This is a disturbing model, because it means that lives are not equal, and that as problems become bigger we become insensitive to the prospect of additional deaths."
Human insensitivity to large-scale human suffering has been observed in the past century with genocides in Armenia, the Ukraine, Nazi Germany and Rwanda, among others.
"We have to understand what it is in our makeup—psychologically, socially, politically and institutionally—that has allowed genocide to go unabated for a century," Slovic said. "If we don't answer that question and use the answer to change things, we will see another century of horrible atrocities around the world."
Slovic previously studied this phenomenon by presenting photographs to a group of subjects. In the first photograph eight children needed $300,000 to receive medical attention in order to save their lives. In the next photograph, one child needed $300,000 for medical bills.
Most subjects were willing to donate to the one and not the group of children.
In his latest research, Slovic and colleagues showed three photos to participants: a starving African girl, a starving African boy and a photo of both of them together.
Participants felt equivalent amounts of sympathy for each child when viewed separately, but compassion levels declined when the children were viewed together.
"The studies ... suggest a disturbing psychological tendency," Slovic said. "Our capacity to feel is limited. Even at two, people start to lose it.”
Tuesday, February 13, 2007
Non-Invasive Preemptive Sepsis Monitor for the Smallest Patients
Drs. Pam Griffin and Randall Moorman at the University of Virginia Health System have developed a bedside monitoring device that detects unique cardiac rhythms, which their research shows are characteristic for the development of neonatal sepsis.
Dr. Randall Moorman, study co-author and cardiologist at the UVa Health System, was instrumental in developing the novel bedside monitoring system to predict the likelihood that sepsis will occur in a baby in the next 24 hours. The new system analyzes heartbeat signals obtained from a standard bedside heart rate monitor and looks for patterns that give an early indication that the baby is getting sick. Characteristics such as decreased variability of the heart rate along with brief episodes of slowing of the heart rate indicate that the infant may be getting an infection. These characteristic patterns can serve as an early warning to the physicians and nurses caring for the infants."At UVa we found characteristic heart rate patterns in infants twelve or more hours before they were known to be infected, and we designed a computer program to detect these patterns," said Moorman. "We worked with colleagues at Wake Forest to be sure that these heart rate characteristics typical of illness happened in sick infants elsewhere."
Now after years of testing and clearance from the Food and Drug Administration, academic research hospitals are participating in a multi-center National Institutes of Health-sponsored study to further test if heart rate characteristic monitoring improves outcomes for NICU babies.
Thursday, February 8, 2007
Rarely seen 'living fossil' shark caught off Tokyo
TOKYO (AFP) - A goblin shark -- a rarely seen species often called a "living fossil" -- was caught alive in Tokyo Bay but died after being put on display, an aquarium said.
The grey, long-nosed shark was caught in fishermen's nets around 150 to 200 metres (500 to 650 feet) deep. It was discovered by officials of the Tokyo Sea Life Park when they took a boat with local fishermen on January 25
The grey, long-nosed shark was caught in fishermen's nets around 150 to 200 metres (500 to 650 feet) deep. It was discovered by officials of the Tokyo Sea Life Park when they took a boat with local fishermen on January 25
"We were able to bring it to the aquarium alive and show it to the public," said an official at the park.
But the shark died on the morning of January 27.
"Dead goblin sharks are caught from time to time, but it is rarely seen alive. We were able to document the way the shark swims. After it died, we dissected the specimen for further studies," he said.
The shark was about 1.3 metres long.
Currently Updating
Sorry that I have not been writing in the blog, I am currently updating some of the links and my other blogs. I will then again start using this blog once that is finished.
CJ
CJ
Monday, February 5, 2007
Quote of the Day
It is no use to blame the looking glass if your face is askew. The mirror is not an instrument of enlightenment but of illusion.
Ghost in the Shell 2: Innocense
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