(HealthDay News) -- For the first time, the American Diabetes Association (ADA) has come out in support of low-carbohydrate diets for people with diabetes who want to manage their weight.
The ADA voiced its support of low-calorie or low-carbohydrate diets in its newly published 2008 clinical practice recommendations.
The recommendations are intended to help physicians guide their patients in diabetes prevention and management.
The ADA estimates that more than 20 million children and adults are living with diabetes in the United States. However, about one-third of those people have the disease but have not yet been diagnosed, according to the association.
Prior to the release of the 2008 recommendations, the ADA did not support low-carbohydrate diets for diabetes management due to a lack of evidence supporting their safety and effectiveness.
Whether a person can stick with a diet is more important than the diet's theme, according to the association. Low-carbohydrate and low-calorie diets are equally effective in helping people lose weight over a year. However, the recommendations do also include guidelines for monitoring the lipid profiles and kidney health of people who choose a low-carbohydrate, high-protein diet.
The recommendations continue to support sustained, moderate weight loss and increased physical activity for people who are overweight, obese, living with diabetes or at risk for becoming diabetic.
"The risks of overweight and obesity are well-known. We recognize that people are looking for realistic ways to lose weight," Ann Albright, president of health care and education for the ADA, said in a prepared statement. "The evidence is clear that both low-carbohydrate and low-fat calorie restricted diets result in similar weight loss at one year. We're not endorsing either of these weight-loss plans over any other method of losing weight. What we want health-care providers to know is that it's important for patients to choose a plan that works for them, and that the health-care team support their patients' weight-loss efforts and provide appropriate monitoring of patients' health."
Being overweight and physically inactive both increase the risk of type 2 diabetes, according to the ADA. Being overweight or obese also make the treatment of type 1 and type 2 diabetes more difficult. The 2008 recommendations state that all adults who are overweight and have an additional risk factor for diabetes should be tested for diabetes or pre-diabetes.
According to the U.S. Centers for Disease Control and Prevention, people who have pre-diabetes can avoid diabetes if they lose 7 percent of their body weight and get more than 150 minutes of activity a week.
Developing and maintaining a disaster kit for diabetes self-management is also included in the new recommendations, along with revised guidelines for care of diabetes in older adults.
More information
To learn more about diabetes, visit the U.S. Centers for Disease Control and Prevention.
more discussion: Forum
· Addiction Forum · Ask the Doctors Forum · Ayurveda Forum · Ayurvedic & Thai Herbs Forum · Colon Cleansing Forum · Dental Forum · Diabetes Forum · Diet Forum · General Cleansing Forum · Hepatitis A, B. C Forum · Integrated Medicine Forum · Live Blood Analysis Forum · Ozone-Oxygen-Forum · pH - Alkaline - Acidity Forum · Weight Loss Forum
Sunday, December 30, 2007
Thursday, December 27, 2007
Radiancio
Enjoy Beauty from the Inside Out - Guaranteed!
Try a Proprietary Formula for Health And Beauty based on Ayurveda - the Oldest and Most Holistic, Comprehensive Medical System Available.
If you want to maximize your beauty and eliminate dull and fatigued looking skin tone, acne, dry and lackluster hair, or weak and cracking nails, there is proven help available. India's men and women have been reaping the powerful benefits of Ayurveda for the past 5,000 years!
Radiancio is a natural supplement geared towards optimizing and enhancing the appearance and condition of your hair, nails, and skin while strengthening the body and overall well-being.
It will help you: Increase Keratin Formation. Enhance Collagen Synthesis. Reduce Elastin Breakdown. Improve Cellular Regeneration. Reduce Formation of Sebum. Clear Pores and Eradicate Acne. Renew Confidence and Esteem. Radiancio is a product of: 5000 years of Ayurvedic wisdom. Modern testing and research.
Breakthrough encapsulation technique. Laboratory-controlled potency. Doctor-approved, carefully calibrated formula. http://www.radiancio.com/index.htm?aff=dreddyclinic
more discussion: Forum
· Addiction Forum · Ask the Doctors Forum · Ayurveda Forum · Ayurvedic & Thai Herbs Forum · Colon Cleansing Forum · Dental Forum · Diabetes Forum · Diet Forum · General Cleansing Forum · Hepatitis A, B. C Forum · Integrated Medicine Forum · Live Blood Analysis Forum · Ozone-Oxygen-Forum · pH - Alkaline - Acidity Forum · Weight Loss Forum
Try a Proprietary Formula for Health And Beauty based on Ayurveda - the Oldest and Most Holistic, Comprehensive Medical System Available.
If you want to maximize your beauty and eliminate dull and fatigued looking skin tone, acne, dry and lackluster hair, or weak and cracking nails, there is proven help available. India's men and women have been reaping the powerful benefits of Ayurveda for the past 5,000 years!
Radiancio is a natural supplement geared towards optimizing and enhancing the appearance and condition of your hair, nails, and skin while strengthening the body and overall well-being.
It will help you: Increase Keratin Formation. Enhance Collagen Synthesis. Reduce Elastin Breakdown. Improve Cellular Regeneration. Reduce Formation of Sebum. Clear Pores and Eradicate Acne. Renew Confidence and Esteem. Radiancio is a product of: 5000 years of Ayurvedic wisdom. Modern testing and research.
Breakthrough encapsulation technique. Laboratory-controlled potency. Doctor-approved, carefully calibrated formula. http://www.radiancio.com/index.htm?aff=dreddyclinic
more discussion: Forum
· Addiction Forum · Ask the Doctors Forum · Ayurveda Forum · Ayurvedic & Thai Herbs Forum · Colon Cleansing Forum · Dental Forum · Diabetes Forum · Diet Forum · General Cleansing Forum · Hepatitis A, B. C Forum · Integrated Medicine Forum · Live Blood Analysis Forum · Ozone-Oxygen-Forum · pH - Alkaline - Acidity Forum · Weight Loss Forum
Sunday, December 23, 2007
School Salad Bar Boosts Kids' Fruit, Veggie Intake
(HealthDay News) -- Simply adding a salad bar to the school lunch room helps elementary school students eat significantly more fruits and vegetables, U.S. researchers say.
The University of California, Los Angeles, study included 337 children in grades 2 through 5 at three L.A. area schools. The children were interviewed before and after their schools started offering a lunch salad bar.
The frequency of the students' fruit and vegetable consumption increased from 2.97 times a day to 4.09 times a day after introduction of the lunch salad bar. There was also a considerable decline in the amount of cholesterol, saturated fat and total fat consumed by the children.
The study, published in the December issue of the journal Public Health Nutrition, included nutrition education for the students.
"One of the major contributing factors to the high rate of overweight children in the United States is that they do not consume the daily recommended servings of fruits and vegetables," lead author Dr. Wendy Slusser, assistant professor of pediatrics at Mattel Children's Hospital UCLA and the UCLA School of Public Health, said in a prepared statement.
"Increasing the availability and accessibility to healthy foods is one way to improve children's diets. In turn, this sets up opportunities for kids to have repeated exposure to healthy food and positively impact their choices," she said.
"The salad bar program showed us that children will indeed eat more fruits and vegetables if offered in an appetizing and accessible manner. Future studies should evaluate parent education with school lunch menu changes, as well as why boys are less likely to eat from the salad bar at lunch than girls," Slusser said.
More information
The Nemours Foundation has more about healthy eating for children.
more discussion: Forum
· Addiction Forum · Ask the Doctors Forum · Ayurveda Forum · Ayurvedic & Thai Herbs Forum · Colon Cleansing Forum · Dental Forum · Diabetes Forum · Diet Forum · General Cleansing Forum · Hepatitis A, B. C Forum · Integrated Medicine Forum · Live Blood Analysis Forum · Ozone-Oxygen-Forum · pH - Alkaline - Acidity Forum · Weight Loss Forum
The University of California, Los Angeles, study included 337 children in grades 2 through 5 at three L.A. area schools. The children were interviewed before and after their schools started offering a lunch salad bar.
The frequency of the students' fruit and vegetable consumption increased from 2.97 times a day to 4.09 times a day after introduction of the lunch salad bar. There was also a considerable decline in the amount of cholesterol, saturated fat and total fat consumed by the children.
The study, published in the December issue of the journal Public Health Nutrition, included nutrition education for the students.
"One of the major contributing factors to the high rate of overweight children in the United States is that they do not consume the daily recommended servings of fruits and vegetables," lead author Dr. Wendy Slusser, assistant professor of pediatrics at Mattel Children's Hospital UCLA and the UCLA School of Public Health, said in a prepared statement.
"Increasing the availability and accessibility to healthy foods is one way to improve children's diets. In turn, this sets up opportunities for kids to have repeated exposure to healthy food and positively impact their choices," she said.
"The salad bar program showed us that children will indeed eat more fruits and vegetables if offered in an appetizing and accessible manner. Future studies should evaluate parent education with school lunch menu changes, as well as why boys are less likely to eat from the salad bar at lunch than girls," Slusser said.
More information
The Nemours Foundation has more about healthy eating for children.
more discussion: Forum
· Addiction Forum · Ask the Doctors Forum · Ayurveda Forum · Ayurvedic & Thai Herbs Forum · Colon Cleansing Forum · Dental Forum · Diabetes Forum · Diet Forum · General Cleansing Forum · Hepatitis A, B. C Forum · Integrated Medicine Forum · Live Blood Analysis Forum · Ozone-Oxygen-Forum · pH - Alkaline - Acidity Forum · Weight Loss Forum
Oxy-Powder®$42.95  Top Quality Colon Cleansing |
Thursday, December 20, 2007
Standard Hepatitis B Treatment Bested by Newcomer
(HealthDay News) -- New research suggests that a newer medication approved for treating hepatitis B is more effective than the standard treatment, lamivudine.
Additionally, the Chinese scientists found that a significantly smaller number of people developed resistance to the newer drug, known as telbivudine (Tyzeka, Sebivo).
The study, which is published in the Dec. 20 issue of the New England Journal of Medicine, found that about 8 percent more people responded to telbivudine than lamivudine, and the risk of resistance was at least halved for people taking telbivudine.
"The multiple therapeutic choices now available for hepatitis B will enhance the ability of clinicians to maintain long-term control of HBV replication, ultimately improving clinical outcomes for more patients. These results support telbivudine as an effective therapy for patients with chronic hepatitis B," the study authors wrote.
Hepatitis B is a viral infection that attacks the liver. It can be spread in many ways, including through the exchange of blood and other bodily fluids when having sex, from sharing needles, or from a mother to her baby during pregnancy, according to the U.S. Centers for Disease Control and Prevention.
As many as one third of people infected have no symptoms, according to the CDC. When symptoms do occur, they may include jaundice, fatigue, abdominal pain, loss of appetite, nausea, vomiting and joint pain. For most people, the infection is transient, lasting no more than six months or so. However, the infection can become chronic. This occurs in only about 6 percent of people over 5 who are infected with the hepatitis B virus, in about 30 percent of infected children between 1 and 5 years old, and in as many as 90 percent of babies who are infected with the virus. Chronic hepatitis B can cause scarring of the liver, which can lead to liver cancer or liver failure.
The goal of treatment is to keep levels of the hepatitis B virus as low as possible. Even if hepatitis B levels become so low that they're undetectable, long-term treatment is still required to prevent recurrence. People with hepatitis B are tested to see if they are positive or negative for E-antigens. A positive result on the E-antigen test often indicates a stronger infection, according to the Hepatitis B Foundation. Someone with a positive result is referred to as HBeAg-positive.
While there are several treatment options available to suppress the virus, one problem is that people can develop resistance to these drugs. Two new drugs, entecavir (Baraclude) and telbivudine, have been approved to treat hepatitis B since 2005.
The current study looked at how effective telbivudine is compared to the standard first-line treatment, lamivudine.
The researchers randomly assigned 1,370 people with chronic hepatitis B to receive either 600 milligrams of telbivudine or 100 milligrams of lamivudine once daily.
After a year of treatment, 75.3 percent of HBeAg-positive people taking telbivudine showed a therapeutic response versus 67 percent of those on lamivudine. In HBeAg-negative people, 64.7 percent of those on telbivudine had a response compared to 56.3 percent of those on lamivudine.
The number of study volunteers who had undetectable levels of hepatitis B virus by the end of the treatment year were much greater for those on telbivudine. In HBeAg-positive people, 60 percent achieved undetectable levels on telbivudine versus 40.4 percent for those taking lamivudine. For HBeAg-negative study participants, telbivudine brought viral levels down to undetectable for 88.3 percent compared to 71.4 percent for lamivudine. Telbivudine also got those viral levels down about five to six weeks faster, on average, than lamivudine.
Resistance developed in 5 percent of HBeAg-positive people taking telbivudine and in 11 percent of those on lamivudine. For those who were HBeAg-negative, the rates of resistance were 2.3 percent for those on telbivudine and 10.7 percent for those on lamivudine.
According to the study's authors, both medications have a similar side effect profile, and no significant differences were found in the current study volunteers.
"Telbivudine seems to work and be safe. It seems to have shown a better therapeutic and histological response," said Dr. Marc Siegel, an internist at New York University Medical Center.
"It decreases the risk of cirrhosis. It's well-tolerated, and it prevents the progression of hepatitis B better than the standard treatment right now," said Siegel.
The study authors pointed out that telbivudine hasn't yet been compared to the other new hepatitis B medication, entecavir, in a randomized clinical trial. Entecavir has also been shown to be more effective than lamivudine and creates less resistance as well.
More information
To learn more about available treatments for hepatitis B, visit the Hepatitis B Foundation.
Additionally, the Chinese scientists found that a significantly smaller number of people developed resistance to the newer drug, known as telbivudine (Tyzeka, Sebivo).
The study, which is published in the Dec. 20 issue of the New England Journal of Medicine, found that about 8 percent more people responded to telbivudine than lamivudine, and the risk of resistance was at least halved for people taking telbivudine.
"The multiple therapeutic choices now available for hepatitis B will enhance the ability of clinicians to maintain long-term control of HBV replication, ultimately improving clinical outcomes for more patients. These results support telbivudine as an effective therapy for patients with chronic hepatitis B," the study authors wrote.
Hepatitis B is a viral infection that attacks the liver. It can be spread in many ways, including through the exchange of blood and other bodily fluids when having sex, from sharing needles, or from a mother to her baby during pregnancy, according to the U.S. Centers for Disease Control and Prevention.
As many as one third of people infected have no symptoms, according to the CDC. When symptoms do occur, they may include jaundice, fatigue, abdominal pain, loss of appetite, nausea, vomiting and joint pain. For most people, the infection is transient, lasting no more than six months or so. However, the infection can become chronic. This occurs in only about 6 percent of people over 5 who are infected with the hepatitis B virus, in about 30 percent of infected children between 1 and 5 years old, and in as many as 90 percent of babies who are infected with the virus. Chronic hepatitis B can cause scarring of the liver, which can lead to liver cancer or liver failure.
The goal of treatment is to keep levels of the hepatitis B virus as low as possible. Even if hepatitis B levels become so low that they're undetectable, long-term treatment is still required to prevent recurrence. People with hepatitis B are tested to see if they are positive or negative for E-antigens. A positive result on the E-antigen test often indicates a stronger infection, according to the Hepatitis B Foundation. Someone with a positive result is referred to as HBeAg-positive.
While there are several treatment options available to suppress the virus, one problem is that people can develop resistance to these drugs. Two new drugs, entecavir (Baraclude) and telbivudine, have been approved to treat hepatitis B since 2005.
The current study looked at how effective telbivudine is compared to the standard first-line treatment, lamivudine.
The researchers randomly assigned 1,370 people with chronic hepatitis B to receive either 600 milligrams of telbivudine or 100 milligrams of lamivudine once daily.
After a year of treatment, 75.3 percent of HBeAg-positive people taking telbivudine showed a therapeutic response versus 67 percent of those on lamivudine. In HBeAg-negative people, 64.7 percent of those on telbivudine had a response compared to 56.3 percent of those on lamivudine.
The number of study volunteers who had undetectable levels of hepatitis B virus by the end of the treatment year were much greater for those on telbivudine. In HBeAg-positive people, 60 percent achieved undetectable levels on telbivudine versus 40.4 percent for those taking lamivudine. For HBeAg-negative study participants, telbivudine brought viral levels down to undetectable for 88.3 percent compared to 71.4 percent for lamivudine. Telbivudine also got those viral levels down about five to six weeks faster, on average, than lamivudine.
Resistance developed in 5 percent of HBeAg-positive people taking telbivudine and in 11 percent of those on lamivudine. For those who were HBeAg-negative, the rates of resistance were 2.3 percent for those on telbivudine and 10.7 percent for those on lamivudine.
According to the study's authors, both medications have a similar side effect profile, and no significant differences were found in the current study volunteers.
"Telbivudine seems to work and be safe. It seems to have shown a better therapeutic and histological response," said Dr. Marc Siegel, an internist at New York University Medical Center.
"It decreases the risk of cirrhosis. It's well-tolerated, and it prevents the progression of hepatitis B better than the standard treatment right now," said Siegel.
The study authors pointed out that telbivudine hasn't yet been compared to the other new hepatitis B medication, entecavir, in a randomized clinical trial. Entecavir has also been shown to be more effective than lamivudine and creates less resistance as well.
More information
To learn more about available treatments for hepatitis B, visit the Hepatitis B Foundation.
Tuesday, December 18, 2007
Health Tip: Cuticle Care
(HealthDay News) - The tearing of a hangnail, or other cuts and tears in the sensitive skin around the fingernails or toenails, can trigger an infection.
Here are suggestions reduce your risk, courtesy of the University of Michigan Health System:
· Addiction Forum · Ask the Doctors Forum · Ayurveda Forum · Ayurvedic & Thai Herbs Forum · Colon Cleansing Forum · Dental Forum · Diabetes Forum · Diet Forum · General Cleansing Forum · Hepatitis A, B. C Forum · Integrated Medicine Forum · Live Blood Analysis Forum · Ozone-Oxygen-Forum · pH - Alkaline - Acidity Forum · Weight Loss Forum
Here are suggestions reduce your risk, courtesy of the University of Michigan Health System:
- Do not pick at your nails and avoid cutting the cuticles.
- Push cuticles back from the nail gently, using a sterile instrument.
- Never pull a hangnail.
- Wear gloves if you are performing an activity that may cut or scratch your fingers.
- See your doctor about a diabetes screening if you get frequent nail infections.
· Addiction Forum · Ask the Doctors Forum · Ayurveda Forum · Ayurvedic & Thai Herbs Forum · Colon Cleansing Forum · Dental Forum · Diabetes Forum · Diet Forum · General Cleansing Forum · Hepatitis A, B. C Forum · Integrated Medicine Forum · Live Blood Analysis Forum · Ozone-Oxygen-Forum · pH - Alkaline - Acidity Forum · Weight Loss Forum
Oxy-Powder®$42.95 Top Quality Colon Cleansing |
Friday, December 14, 2007
Menopause May Be Unique to Humans
(HealthDay News) -- Scientists have found no evidence that female chimpanzees go through menopause in the way that human females do -- even though their ability to reproduce tends to taper off at a similar age.
"When we look at the healthiest individuals, it looks like chimpanzees may actually be reproducing better than humans in their forties," researcher Melissa Emery Thompson, of Harvard University, said in a prepared statement. "The oldest chimpanzee known to give birth in the wild is estimated to have been 55. She began reproductive cycling again shortly before her death at the age of 63."
Thompson's team analyzed fertility rate data on female chimpanzees in the wild. They found that they, like humans, have declining birth rates after the age of 40. This suggests that the "biological clock" in humans has been relatively preserved over the course of evolution, the study authors said.
However, unlike humans, female chimpanzee fertility tends to decline along with their survival odds. Healthy females maintain high birth rates late into life.
"The adaptive significance of human menopause, or post-reproductive life span, is still debated. This study provides greater evolutionary context to this debate," Thompson and her colleagues wrote.
These findings in chimpanzees, along with recent findings in wild gorillas and orangutans, indicate that "menopause is not part of the life cycle of living apes but has been uniquely derived in the human lineage."
The study is published in the Dec. 13 issue of the journal Current Biology.
More information
The U.S. National Institute on Aging has more about menopause.
more discussion: Forum
· Addiction Forum · Ask the Doctors Forum · Ayurveda Forum · Ayurvedic & Thai Herbs Forum · Colon Cleansing Forum · Dental Forum · Diabetes Forum · Diet Forum · General Cleansing Forum · Hepatitis A, B. C Forum · Integrated Medicine Forum · Live Blood Analysis Forum · Ozone-Oxygen-Forum · pH - Alkaline - Acidity Forum · Weight Loss Forum
"When we look at the healthiest individuals, it looks like chimpanzees may actually be reproducing better than humans in their forties," researcher Melissa Emery Thompson, of Harvard University, said in a prepared statement. "The oldest chimpanzee known to give birth in the wild is estimated to have been 55. She began reproductive cycling again shortly before her death at the age of 63."
Thompson's team analyzed fertility rate data on female chimpanzees in the wild. They found that they, like humans, have declining birth rates after the age of 40. This suggests that the "biological clock" in humans has been relatively preserved over the course of evolution, the study authors said.
However, unlike humans, female chimpanzee fertility tends to decline along with their survival odds. Healthy females maintain high birth rates late into life.
"The adaptive significance of human menopause, or post-reproductive life span, is still debated. This study provides greater evolutionary context to this debate," Thompson and her colleagues wrote.
These findings in chimpanzees, along with recent findings in wild gorillas and orangutans, indicate that "menopause is not part of the life cycle of living apes but has been uniquely derived in the human lineage."
The study is published in the Dec. 13 issue of the journal Current Biology.
More information
The U.S. National Institute on Aging has more about menopause.
more discussion: Forum
· Addiction Forum · Ask the Doctors Forum · Ayurveda Forum · Ayurvedic & Thai Herbs Forum · Colon Cleansing Forum · Dental Forum · Diabetes Forum · Diet Forum · General Cleansing Forum · Hepatitis A, B. C Forum · Integrated Medicine Forum · Live Blood Analysis Forum · Ozone-Oxygen-Forum · pH - Alkaline - Acidity Forum · Weight Loss Forum
Tuesday, December 11, 2007
Drug Combo With Antibiotic May Slow MS Progression
(HealthDay News) -- Combining an antibiotic with a medication currently used to treat multiple sclerosis may slow progression of the disease, according to researchers at the Louisiana State Health Sciences Center in Shreveport.
Their study included 15 patients (average age 44.5) with relapsing-remitting MS who'd been taking interferon for at least six months and were experiencing symptoms and developing new brain lesions.
For four months, the patients took 100 milligrams daily of the antibiotic doxycycline in addition to their interferon therapy. During the study, they had monthly neurological examinations, MRI brain scans and blood work.
At the end of the four months, 60 percent of the patients had a more than 25 percent reduction in the number of brain lesions. Patients also had lower disability scores. One patient relapsed.
Side effects were mild and included only the known side effects of the two drugs individually, rather than side effects caused by combining the two medications, the researchers said.
The study, funded by Biogen Idec Inc., was posted online Dec. 10 and will be published in the February 2008 print issue of the Archives of Neurology.
"There is a growing interest in combination therapy in patients with MS to stabilize the clinical course, reduce the rate of clinical relapses and decelerate the progressive course of the underlying pathologic mechanism," the study authors wrote. "Overall, data from this cohort suggest that the treatment combination of oral doxycycline and interferon beta-1a may be safe and effective in some patients with MS; however, further controlled clinical trials are warranted to demonstrate safety and efficacy in a larger patient population."
More information
The U.S. National Institute of Neurological Disorders and Stroke has more about multiple sclerosis.
Their study included 15 patients (average age 44.5) with relapsing-remitting MS who'd been taking interferon for at least six months and were experiencing symptoms and developing new brain lesions.
For four months, the patients took 100 milligrams daily of the antibiotic doxycycline in addition to their interferon therapy. During the study, they had monthly neurological examinations, MRI brain scans and blood work.
At the end of the four months, 60 percent of the patients had a more than 25 percent reduction in the number of brain lesions. Patients also had lower disability scores. One patient relapsed.
Side effects were mild and included only the known side effects of the two drugs individually, rather than side effects caused by combining the two medications, the researchers said.
The study, funded by Biogen Idec Inc., was posted online Dec. 10 and will be published in the February 2008 print issue of the Archives of Neurology.
"There is a growing interest in combination therapy in patients with MS to stabilize the clinical course, reduce the rate of clinical relapses and decelerate the progressive course of the underlying pathologic mechanism," the study authors wrote. "Overall, data from this cohort suggest that the treatment combination of oral doxycycline and interferon beta-1a may be safe and effective in some patients with MS; however, further controlled clinical trials are warranted to demonstrate safety and efficacy in a larger patient population."
More information
The U.S. National Institute of Neurological Disorders and Stroke has more about multiple sclerosis.
Friday, December 07, 2007
New Kind of Stem Cells Reverse Sickle Cell Anemia
(HealthDay News) --Scientists have succeeded in using cells virtually identical to embryonic stem cells to "correct" sickle cell anemia in mice.
The breakthrough was made possible by another advance announced barely two weeks ago that scientists had created "induced pluripotent stem" (iPS) cells from human skin cells. These iPS cells are very similar, although not exactly identical, to embryonic stem cells. The process bypasses the need to use embryos, and thus circumvents many of the ethical complications surrounding this type of research.
The first research announcement had left open the question of whether iPS cells could actually be used for therapeutic purposes.
That question has now been at least partially answered by this latest report.
"This study is important as a proof of principle that these iPS cells can be used to correct mutations," said Dr. Jacob Hanna, lead author of the study, which is published in the Dec. 6 online issue of Science Express.
Hanna is a postdoctoral fellow in Rudolf Jaenisch's laboratory at The Whitehead Institute in Boston.
"It's very fascinating that they're using these reprogrammed cells to make hematopoietic cells [which can produce different blood and immune cells] to then treat the genetic defect in these mice," said Paul Sanberg, director of the University of South Florida Center for Aging and Brain Repair in Tampa.
Embryonic stem cells are pluripotent, meaning they have the capacity to develop into virtually any cell type in the body. The hope is that such cells may one day yield treatments or cures for diseases such as diabetes, liver failure, spinal injury, stroke, Alzheimer's disease and heart disease.
However, harvesting embryonic stem cells involves destroying a viable embryo, stirring much political debate. In the United States, embryonic stem cell research has been severely limited since August 2001, when President George W. Bush placed limits on federal funding of the field and restricted the number of embryonic stem cell lines that could be used.
Since that time, researchers have been racing to find other sources of viable stem cells -- iPS cells are one outcome of that race.
For this study, Hanna and his colleagues used a process similar to the one revealed two weeks ago, taking skin cells from the tails of mice with sickle cell anemia and using them to produce iPS cells. The researchers then replaced the mutated gene with a healthy gene in the new cells.
Once the iPS cells had differentiated into hematopoietic stem cells, they were reintroduced into the mice, where they began to produce healthy blood cells.
Some 10 percent of the human population, mostly blacks, carry the mutation for sickle cell anemia. The exact mutation is well known, as is the protocol for differentiating embryonic stem cells into precursors of bone marrow adult stem cells, making the condition well-suited to study.
In sickle cell anemia, red blood cells become sickle-shaped and can't move easily through the blood vessels.
Although exciting, the process is still fraught with potential danger.
The procedure to turn skin cells into iPS cells could lead to cancer (although none of the mice in this study showed any evidence of tumors). Also, the healthy genes were introduced into the mice via retroviruses, which can introduce other problems.
"Now the major question in the field is can you make iPSs with a safer method, that don't use retroviruses, because viruses can integrate into the DNA and activate dangerous genes or silence necessary genes," Hanna explained.
"I like the fact that they're saying this is a first step, because they're using retroviruses, and they have to show that this is a safe approach," added Sanberg.
More information
Learn more about stem cells at the International Society for Stem Cell Research.
The breakthrough was made possible by another advance announced barely two weeks ago that scientists had created "induced pluripotent stem" (iPS) cells from human skin cells. These iPS cells are very similar, although not exactly identical, to embryonic stem cells. The process bypasses the need to use embryos, and thus circumvents many of the ethical complications surrounding this type of research.
The first research announcement had left open the question of whether iPS cells could actually be used for therapeutic purposes.
That question has now been at least partially answered by this latest report.
"This study is important as a proof of principle that these iPS cells can be used to correct mutations," said Dr. Jacob Hanna, lead author of the study, which is published in the Dec. 6 online issue of Science Express.
Hanna is a postdoctoral fellow in Rudolf Jaenisch's laboratory at The Whitehead Institute in Boston.
"It's very fascinating that they're using these reprogrammed cells to make hematopoietic cells [which can produce different blood and immune cells] to then treat the genetic defect in these mice," said Paul Sanberg, director of the University of South Florida Center for Aging and Brain Repair in Tampa.
Embryonic stem cells are pluripotent, meaning they have the capacity to develop into virtually any cell type in the body. The hope is that such cells may one day yield treatments or cures for diseases such as diabetes, liver failure, spinal injury, stroke, Alzheimer's disease and heart disease.
However, harvesting embryonic stem cells involves destroying a viable embryo, stirring much political debate. In the United States, embryonic stem cell research has been severely limited since August 2001, when President George W. Bush placed limits on federal funding of the field and restricted the number of embryonic stem cell lines that could be used.
Since that time, researchers have been racing to find other sources of viable stem cells -- iPS cells are one outcome of that race.
For this study, Hanna and his colleagues used a process similar to the one revealed two weeks ago, taking skin cells from the tails of mice with sickle cell anemia and using them to produce iPS cells. The researchers then replaced the mutated gene with a healthy gene in the new cells.
Once the iPS cells had differentiated into hematopoietic stem cells, they were reintroduced into the mice, where they began to produce healthy blood cells.
Some 10 percent of the human population, mostly blacks, carry the mutation for sickle cell anemia. The exact mutation is well known, as is the protocol for differentiating embryonic stem cells into precursors of bone marrow adult stem cells, making the condition well-suited to study.
In sickle cell anemia, red blood cells become sickle-shaped and can't move easily through the blood vessels.
Although exciting, the process is still fraught with potential danger.
The procedure to turn skin cells into iPS cells could lead to cancer (although none of the mice in this study showed any evidence of tumors). Also, the healthy genes were introduced into the mice via retroviruses, which can introduce other problems.
"Now the major question in the field is can you make iPSs with a safer method, that don't use retroviruses, because viruses can integrate into the DNA and activate dangerous genes or silence necessary genes," Hanna explained.
"I like the fact that they're saying this is a first step, because they're using retroviruses, and they have to show that this is a safe approach," added Sanberg.
More information
Learn more about stem cells at the International Society for Stem Cell Research.
Sunday, December 02, 2007
Overlooked Mutation Can Spur HIV Drug Resistance
(HealthDay News) -- One in 10 HIV-infected people receiving drug treatment harbors a hidden genetic mutation that renders certain strains of the virus more resistant to antiretroviral medications, researchers say.
Their study suggests that the N348I mutation should now be added to standard HIV gene tests that AIDS specialists use as they decide which cocktail of drugs a patient should receive.
"The importance of N348I is also underscored by the fact that it appears relatively early after starting drug therapy," noted study senior author Gilda Tachedjian, head of the Molecular Interactions Group at the Macfarlane Burnet Institute for Medical Research and Public Health, in Melbourne, Australia.
The mutation, largely overlooked by researchers, appears to confer resistance to zidovudine (AZT or Retrovir), the first drug ever approved to fight HIV; and nevirapine (Viramune), one of a group of powerful antiretroviral medications.
Both medicines fall into a broad category of drugs called reverse transcriptase inhibitors (RTIs), so named because they target a key enzyme on HIV called reverse transcriptase.
Tachedjian's group published its findings late Friday in the December issue of PLoS Medicine on the eve of World AIDS Day.
Gene tests aimed at gauging a particular strain of HIV's resistance to common AIDS drugs are routine in clinical practice, noted Mattias Gotte, an associate professor of microbiology and immunology at McGill University in Montreal. Gotte is also the author of an accompanying commentary in the journal.
"You go as an infected person to a clinician, and you get a certain regimen. Most of the time the clinician uses genotyping [gene tests] to see whether certain preexisting mutations may compromise therapy," he explained. "The other thing that happens is when you are on a failing regimen. Then, the clinician would genotype the virus and eventually base his or her decision on the results."
The trick is to match the patient's version of HIV to a group of drugs that will be least prone to resistance.
In the case of nevirapine and other widely used RTIs, AIDS experts thought they knew where the key points of resistance lay on the reverse transcriptase molecule, and so they designed their tests accordingly.
"Genotyping assays currently look for drug-resistance mutations in the first two-thirds (N-terminal region) of the reverse transcriptase," Tachedjian explained. "The reason for this is that it is where most of the important resistance mutations have occurred."
But there's another region on the enzyme, called the C-terminal, that's also essential to proper reverse transcriptase function.
"Our logic for the current study was that since the C-terminal region is involved in how the enzyme 'works,' then it is likely that drug resistance mutations could [also] emerge in this region," Tachedjian said.
In their study, her team analyzed samples from more than 1,000 HIV patients who had received antiretroviral drug therapy. They then compared their results to samples taken from 368 HIV-positive patients who had not yet undergone drug therapy.
The C-Terminal N348I mutation turned up in 12 percent of patients who'd been exposed to HIV-suppressing drugs, the researchers report.
In contrast, fewer than 1 percent of the not-treated patients had the resistance-linked mutation -- suggesting that it developed after the virus had been exposed to AIDS drugs.
"The N348I mutation is different from most of the other mutations described to date because it confers some level of resistance to nevirapine and zidovudine, which are drugs belonging to two different classes of reverse transcriptase inhibitors," Tachedjian pointed out. "N348I can work alone to confer resistance to nevirapine and zidovudine and can augment resistance when in the presence of other drug mutations found in the N-terminal region of the enzyme."
The trouble is, standard genotyping tests are designed to pick up N-terminal mutations but they ignore the C-terminal region, including N348I.
According to Tachedjian, that means the finding "may have implications for genotypic resistance testing, particularly for patients on zidovudine and nevirapine therapy, and therefore should be considered for incorporation in [standard] genotyping assays."
The advent of new antiretroviral drugs means these gene tests are already going to have to be altered, she added, "and while we are making these changes it could be relatively straightforward to include" the C-terminal region, and N348I, in the tests as well.
Tachedjian believes other overlooked, resistance-conferring mutations might also be hiding out in the C-terminal region, and her team is currently looking into that possibility.
In the meantime, the N348I discovery could have implications for AIDS drug development, Gotte pointed out.
"We learn a lot when we study mechanisms of resistance, in terms of what we should avoid in regard to drug development and how we can make drugs better," he said.
Gotte stressed that HIV-positive patients should not be overly concerned that their doctors are missing a key factor as they seek to determine the best treatment strategy.
While adding N348I to the genotyping mix will improve treatment design, "it's still a minor piece of the puzzle that's missing here," he said. "I wouldn't be too worried about this because clinicians also look for other parameters" as they choose effective therapies, he added.
More information
Find out more about HIV at the U.S. National Institute of Allergy and Infectious Diseases.
Their study suggests that the N348I mutation should now be added to standard HIV gene tests that AIDS specialists use as they decide which cocktail of drugs a patient should receive.
"The importance of N348I is also underscored by the fact that it appears relatively early after starting drug therapy," noted study senior author Gilda Tachedjian, head of the Molecular Interactions Group at the Macfarlane Burnet Institute for Medical Research and Public Health, in Melbourne, Australia.
The mutation, largely overlooked by researchers, appears to confer resistance to zidovudine (AZT or Retrovir), the first drug ever approved to fight HIV; and nevirapine (Viramune), one of a group of powerful antiretroviral medications.
Both medicines fall into a broad category of drugs called reverse transcriptase inhibitors (RTIs), so named because they target a key enzyme on HIV called reverse transcriptase.
Tachedjian's group published its findings late Friday in the December issue of PLoS Medicine on the eve of World AIDS Day.
Gene tests aimed at gauging a particular strain of HIV's resistance to common AIDS drugs are routine in clinical practice, noted Mattias Gotte, an associate professor of microbiology and immunology at McGill University in Montreal. Gotte is also the author of an accompanying commentary in the journal.
"You go as an infected person to a clinician, and you get a certain regimen. Most of the time the clinician uses genotyping [gene tests] to see whether certain preexisting mutations may compromise therapy," he explained. "The other thing that happens is when you are on a failing regimen. Then, the clinician would genotype the virus and eventually base his or her decision on the results."
The trick is to match the patient's version of HIV to a group of drugs that will be least prone to resistance.
In the case of nevirapine and other widely used RTIs, AIDS experts thought they knew where the key points of resistance lay on the reverse transcriptase molecule, and so they designed their tests accordingly.
"Genotyping assays currently look for drug-resistance mutations in the first two-thirds (N-terminal region) of the reverse transcriptase," Tachedjian explained. "The reason for this is that it is where most of the important resistance mutations have occurred."
But there's another region on the enzyme, called the C-terminal, that's also essential to proper reverse transcriptase function.
"Our logic for the current study was that since the C-terminal region is involved in how the enzyme 'works,' then it is likely that drug resistance mutations could [also] emerge in this region," Tachedjian said.
In their study, her team analyzed samples from more than 1,000 HIV patients who had received antiretroviral drug therapy. They then compared their results to samples taken from 368 HIV-positive patients who had not yet undergone drug therapy.
The C-Terminal N348I mutation turned up in 12 percent of patients who'd been exposed to HIV-suppressing drugs, the researchers report.
In contrast, fewer than 1 percent of the not-treated patients had the resistance-linked mutation -- suggesting that it developed after the virus had been exposed to AIDS drugs.
"The N348I mutation is different from most of the other mutations described to date because it confers some level of resistance to nevirapine and zidovudine, which are drugs belonging to two different classes of reverse transcriptase inhibitors," Tachedjian pointed out. "N348I can work alone to confer resistance to nevirapine and zidovudine and can augment resistance when in the presence of other drug mutations found in the N-terminal region of the enzyme."
The trouble is, standard genotyping tests are designed to pick up N-terminal mutations but they ignore the C-terminal region, including N348I.
According to Tachedjian, that means the finding "may have implications for genotypic resistance testing, particularly for patients on zidovudine and nevirapine therapy, and therefore should be considered for incorporation in [standard] genotyping assays."
The advent of new antiretroviral drugs means these gene tests are already going to have to be altered, she added, "and while we are making these changes it could be relatively straightforward to include" the C-terminal region, and N348I, in the tests as well.
Tachedjian believes other overlooked, resistance-conferring mutations might also be hiding out in the C-terminal region, and her team is currently looking into that possibility.
In the meantime, the N348I discovery could have implications for AIDS drug development, Gotte pointed out.
"We learn a lot when we study mechanisms of resistance, in terms of what we should avoid in regard to drug development and how we can make drugs better," he said.
Gotte stressed that HIV-positive patients should not be overly concerned that their doctors are missing a key factor as they seek to determine the best treatment strategy.
While adding N348I to the genotyping mix will improve treatment design, "it's still a minor piece of the puzzle that's missing here," he said. "I wouldn't be too worried about this because clinicians also look for other parameters" as they choose effective therapies, he added.
More information
Find out more about HIV at the U.S. National Institute of Allergy and Infectious Diseases.
Subscribe to:
Posts (Atom)
Kamarani
