Friday, June 18, 2010
By Ed Edelson
Friday, June 18, 2010
Of that list, five risk factors usually related to lifestyle -- high blood pressure, smoking, , diet and physical activity -- are responsible for a full 80 percent of all stroke risk, according to the researchers.
The findings come the INTERSTROKE study, a standardized case-control study of 3,000 people who had had strokes and an equal number of healthy individuals with no from 22 countries. It was published online June 18 in The Lancet.
The study -- slated to be presented Friday at the World Congress on Cardiology in Beijing -- reports that the 10 factors significantly associated with stroke risk are high , smoking, physical activity, waist-to-hip ratio (abdominal obesity), diet, blood lipid (fat) levels, diabetes, alcohol intake, stress and depression, and heart disorders.
important that most of the risk factors associated with stroke are
modifiable," said Dr. Martin J. O'Donnell, an associate professor of
Controlling blood pressure is important, he said, because it plays a major role in both forms of stroke: ischemic, the most common form (caused by blockage of a brain blood vessel), and hemorrhagic or bleeding stroke, in which a blood vessel in the brain bursts.
"The most important thing about hypertension is its controllability," O'Donnell said. "Blood pressure is easily measured, and there are lots of treatments."
He added that the other risk factors -- smoking, abdominal obesity, diet and physical activity -- in the top five contributors to stroke risk were modifiable as well.
The researchers pointed out several potential limitations of the study, including the sample size, which they said "might be inadequate to provide reliable information" about the importance of each risk factor in different regions and ethnic groups.
Many of the same risk factors have cropped up in other studies, but this is the first stroke risk study to include both low- and middle-income participants in developing countries and to include a brain scan of all participating stroke survivors, according to the researchers.
countries joining in the study were
INTERSTROKE study confirms that "is the
leading cause of stroke in developing countries" as well as developed nations,
Dr. Jack V. Tu, of the
A second phase of the INTERSTROKE study is underway, with researchers looking at the importance of risk factors in different regions, ethnic groups and types of ischemic stroke. They'll also study the association between genetics and stroke risk. The researchers plan to enroll 20,000 participants.
Larry B. Goldstein, director of the
"The bottom line is that the risk factors for low- and middle-income countries seem to be pretty similar to those of Western countries," Goldstein said. "The findings reiterate the importance of attention to lifestyle factors in stroke risk -- diet, smoking, physical activity."
Controllable and uncontrollable are listed by the American Heart Association.
By Amy Norton
Friday, June 18, 2010
Researchers found that among 3,500 older adults they followed for up to a dozen years, the risk of developing depression symptoms declined by 2 percent for every 10-milligram (mg) increase in daily vitamin B6 from .
The same was true for every 10-microgram (mcg) increase in vitamin B12 intake.
The findings, published in the American Journal of Clinical Nutrition, do not prove that the B vitamins themselves protect against depression. But the results do echo those of some previous studies tying the vitamins -- as well as folate, another B vitamin -- to depression risk.
The prime shortcoming of most of those previous studies, however, was that they studied people at one point in time, rather than following them over years -- making it unclear whether the lower B-vitamin intake came before or after the depression.
The main strength of the current study is that it followed a large group of people over 12 years, measuring depression symptoms at several time points, lead researcher Dr. Kimberly Skarupski, an associate professor at Rush University Medical Center in Chicago, told Reuters Health in an email.
That bolsters the case that relatively low intakes of the might contribute to depression in some people. Still, Skarupski and her colleagues say their results should be interpreted with "caution," because study participants' consumption of the vitamins might be a proxy for other factors, like a generally .
The study included 3,500 Chicago-area adults who were at least 65 years old and depression-free at the outset. Participants' consumption of folate and vitamins B6 and B12 was estimated based on their responses to a detailed dietary questionnaire. They were then assessed for depression periodically over the next dozen years.
The researchers found that anywhere from 11 percent to 14 percent of participants had symptoms indicative of clinical depression at some point during the follow-up.
When they looked at the relationship between B vitamins and depression, they found that the risk generally dipped as consumption of B6 or B12 increased. The link held when Skarupski's team accounted for a number of other factors -- such as race, education and income, antidepressant use and like smoking and drinking.
While the results do not prove cause-and-effect, Skarupski said they do emphasize the importance of older adults' being mindful of their diets.
Vitamin B6 is found in a range of foods, including beans, potatoes, bananas, meat, chicken, peanut butter and certain fish, like salmon and tuna. The for men older than 50 is 1.7 mg per day, while women are advised to get 1.5 mg; the upper limit is set at 100 mg daily, as too much B6 can cause nerve damage.
The recommended dietary allowance for the vitamin in adults is 2.4 micrograms per day; there is no established upper limit for B12 because of its low potential for harmful effects. Because older adults have difficulty absorbing the B12 naturally found in food, experts generally recommend that they try to get their daily allotment through fortified food or a multivitamin.
People in the current study consumed anywhere from 0.6 mg to 200 mg of B6 each day, while B12 intakes ranged from 0.3 to 266 mcg per day.
According to Skarupski's team, it is biologically plausible that the two vitamins would affect depression risk.
Both B6 and B12 are involved in healthy nervous system function, and overt B12 deficiency causes a neurological syndrome that includes problems with thinking and memory, as well as depression symptoms.
For its part, vitamin B6 is involved in synthesizing chemical "messengers" in the brain, including serotonin. Serotonin dysfunction is believed to play a key role in depression.
Much remains to be learned about B vitamins and depression, however. There is little evidence, for example, that taking the vitamins can help treat depression -- though preliminary findings from one recent study suggested that folate may enhance the effects of antidepressant medication.
this study, folate intake was not linked to
depression risk, as it has been in some studies from other countries. A
potential explanation, Skarupski and her colleagues
speculate, is that outright folate deficiency is rare
Friday, June 18, 2010
FRIDAY, June 18 (HealthDay News) -- New research appears to dash hopes that people who consume more vitamin D might be at less risk of developing several less-common types of cancer.
Authors of a new study analyzed blood samples drawn from more than 12,000 men and women in 10 studies. The previous studies followed the patients for as long as 33 years, allowing researchers to determine if they developed cancer.
"We did not see in persons with high vitamin D blood concentrations compared to normal concentrations for any of these cancers," said study co-investigator Dr. Demetrius Albanes of the U.S. National Cancer Institute in an institute news release. "And, at the other end of the spectrum, we did not see higher cancer risk for participants with low levels."
However, the researchers did find that people with high levels of vitamin D were more likely to develop pancreatic cancer. It's not clear if there's a cause-and-effect relationship, and the study authors called for more research to assess the .
The findings were published online June 18 in advance of print publication in the July issue of the American Journal of Epidemiology.
more about vitamin
D, see the
Friday, June 18, 2010
ScienceDaily (June 18, 2010) Italian postmenopausal women who have a low calcium intake show a higher risk of developing both osteoporosis and hypertension (a chronic medical condition in which arterial blood pressure is elevated) than those who consume higher levels of calcium according to research presented at EULAR 2010, the Annual Congress of the European League Against Rheumatism in Rome, Italy.
In this Italian study of 825 postmenopausal women with hypertension, a significantly increased proportion of women (35.4%) who consumed a lower amount of calcium through intake from dairy sources, had a concurrent diagnosis of both hypertension and osteoporosis, compared with women who consumed a higher amount of calcium (19.3% p<0.001).
Further statistical analyses revealed that a lower calcium intake was associated with an increased risk of developing hypertension or osteoporosis over time when compared with controls (Odds Ratio (OR) hypertension: 1.43; 95%CI: 1.12-1.82, osteoporosis: OR 1.46; CI: 1.15-1.85). Women who consumed a lower amount of calcium were shown to be most likely to develop both conditions over time compared with women consuming a higher amount of calcium (OR 1.60; CI: 1.09-2.34).
"Our study confirms that there may be a link between
hypertension and low bone mass and that a low calcium intake could be a risk
factor for the development of osteoporosis in postmenopausal women" said
Professor Maria Manara, Department of Rheumatology, Gaetano Pini Institute,
The 825 subjects involved in the study were recruited
from a cohort of 9,898 postmenopausal women referred to the Osteometabolic
unit of the Gaetano Pini
Friday, June 18, 2010
Researchers analyzed nine studies collected by the International Head and Neck Cancer Epidemiology consortium. They found that regular coffee drinkers (four or more cups a day) were 39 percent less likely to develop oral and pharynx cancers than people who didn't drink coffee.
"Since coffee is so widely used and there is a relatively high incidence and low of these forms of cancers, our results have important public health implications that need to be further addressed," lead researcher Mia Hashibe, an assistant professor in the department of family and preventive medicine at the University of Utah, said in an American Association for news release.
"What makes our results so unique is that we had a very large sample size, and since we combined data across many studies, we had more statistical power to detect associations between cancer and coffee," she added.
The study appears in the current issue of the journal Cancer Epidemiology, Biomarkers & Prevention.
The U.S. National Cancer Institute has more about head and neck cancer.
Friday, June 18, 2010
ScienceDaily (June 18, 2010) During pregnancy, many women experience remission of autoimmune diseases like multiple sclerosis and uveitis. Now, scientists have described a biological mechanism responsible for changes in the immune system that helps to explain the remission.
The expression of an enzyme known as pyruvate kinase is reduced in immune cells in pregnant women compared to non-pregnant women, according to Howard R. Petty, Ph.D., biophysicist at the University of Michigan Kellogg Eye Center and Roberto Romero, M.D., of the National Institutes for Health.
The study, which appears online ahead of print in the August issue of the American Journal of Reproductive Immunology, also reports that expression of the enzyme is lower in pregnant women compared to those with pre-eclampsia, a condition with inflammatory components.
The study is significant because the newly discovered mechanism points to a pathway that could be targeted for treatment. "It may be possible to design drugs that mildly suppress pyruvate kinase activity as a means of replicating the immune status of normal pregnancy," says Petty.
In addition to pre-eclampsia, he believes that rheumatoid arthritis, type 1 diabetes, and uveitis may eventually yield to similarly designed drugs.
In his search to explain the phenomenon, Petty knew to look for a metabolic pathway or mechanism with two characteristics. It had to "dial down" the intensity of the normal immune response, an action needed so that a pregnant woman does not reject the fetus, which has proteins from the father that are "foreign" to the mother. At the same time, such a mechanism must support cell growth needed by the developing fetus.
The activity of the enzyme pyruvate kinase -- and its product, pyruvate -- fills both roles: promoting cell growth while modifying the immune response. Because pyruvate kinase activity is depressed during pregnancy, cell metabolism supports an increased production of lipids, carbohydrates, amino acids, and other substances that support cell growth.
Petty explains that our normal robust immune response depends upon pyruvate to promote calcium signaling, which, in turn, stimulates the production of messenger molecules called cytokines. When pyruvate is decreased during pregnancy, calcium signaling is also reduced, and the immune response is different than that in non-pregnant individuals. Says Petty, "Modification of signaling along this pathway allows the pregnant woman to maintain an immune response, but at a level that will not harm the fetus."
The study included 21 women in their third trimester of a normal pregnancy, 25 women with pre-eclampsia, and a control group of non-pregnant women. Petty and colleagues used a variety of methods to confirm their findings, including fluorescence microscopy and flow cytometry, which are used to study cell signaling.
The higher levels of the enzyme seen in women with pre-eclampsia bolster the study's findings, says Petty. "Pre-eclampsia has features of inflammatory disease. If you don't reduce these pyruvate levels, you heighten inflammatory disease," he adds. Petty wonders whether one day enzyme levels could be tested early in pregnancy to predict the likelihood of developing pre-eclampsia or other complications.
It is possible, says Petty, that the general mechanisms described in the current study may apply to more than one complication of pregnancy. This possibility -- and that of designing drugs to suppress pyruvate kinase activity -- is the focus of future research. "I have a long list of things I'd like to see developed for the clinic in the next five years," adds Petty.
Romero is chief of the Perinatology Research Branch (PRB) of the National Institute of Child Health and Human Development/National Institutes of Health (NICHD/NIH).
Yi Xu, Sally A. Madsen-Bouterse, Roberto Romero, Sonia Hassan, Pooja Mittal, Megan Elfline, Aiping Zhu, Howard R. Petty. Leukocyte Pyruvate Kinase Expression is Reduced in Normal Human Pregnancy but not in Pre-eclampsia. American Journal of Reproductive Immunology, 2010; DOI: 10.1111/j.1600-0897.2010.00881.x
By Ed Edelson
Friday, June 18, 2010
FRIDAY, June 18 (HealthDay News) -- Drinking coffee or tea in moderation reduces the risk of developing , and both high and moderate tea drinking reduces the risk of dying from the condition, according to a large-scale study from Dutch researchers.
It found that people who had two to four cups a day of coffee had a 20 percent lower risk of heart disease compared to those drinking less than two or more than four cups a day. Moderate also slightly -- but not significantly -- reduced the risk of death from heart disease and all causes.
Tea's performance was stronger on both counts. Drinking three to six cups of tea a day was associated with a 45 percent from heart disease, compared to drinking less than one cup a day, and drinking more than six cups of tea a day was associated with a 36 percent lower risk of getting heart disease in the first place.
No effect of coffee or tea consumption on the risk of stroke was seen in the study.
Study authors found, however, that coffee and tea drinkers in The Netherlands had very different health behaviors, with more coffee drinkers smoking and having less healthy diets.
Suzanne Steinbaum, director of women and heart
Experts note, however, that it's too early to make specific recommendations on coffee and tea drinking for the sake of better health, despite a growing number of studies that suggest the beverages may help protect against heart disease.
Discussing the study from The Netherlands in context of other research, Hu noted that this is not the first report on coffee and tea consumption and heart disease mortality. "Overall, the studies were consistent in showing that higher did not increase the risk of morbidity or mortality from cardiovascular disease," he said. "Several suggested there might be a slight protective effect."
Those studies also suggested a protective effect of tea, Hu said, but "the problem with this is that different types of tea are consumed in different populations, so it is difficult to compare results in different studies." (Most people in the Dutch study reported using black tea).
Many people still have a lingering belief that coffee might be dangerous, because early studies suggested an increased risk of heart disease, Hu said. Some of those studies used self-reports from people after a heart attack, so there was a problem of "recall bias," Hu noted. "Certainly, is not likely to cause harm in terms of cardiovascular health," he concluded.
"Common sense should always prevail," said Dr. Arthur L. Klatsky, a senior consultant in cardiology at Kaiser Permanente Northern California and an adjunct investigator in its division of research, who led a previous study showing reduced incidence of heart rhythm abnormalities in coffee drinkers. "If you have unpleasant symptoms from caffeine, you should avoid it. Some people get insomnia even if they take it at noon."
But there is evidence that moderate coffee consumption is associated with a decreased risk of type 2 diabetes, Klatsky said.
One possible confounding factor is that people who drink moderate amounts of either coffee or tea tend to have a healthier lifestyle, exercising more and avoiding obesity, said Steinbaum.
Still, "this and other studies have shown that drinking two to four a day is associated with a 20 percent reduction in heart disease," Steinbaum said. When people ask her whether coffee drinking is dangerous, "my response is that drinking coffee is not unhealthy," she said.
The study was published online June 18 in Arteriosclerosis, Thrombosis and Vascular Biology.
More information on caffeine and heart disease can be found at the American Heart Association.
Thursday, June 17, 2010
Thursday, June 17, 2010
ScienceDaily (June 17,
2010) Contrary to
popular belief, paying a premium price for free-range eggs may not be healthier
than eating regular eggs, a new study reports. Scientists found that free-range
Their findings appear in ACS' bi-weekly Journal of Agricultural and Food Chemistry.
In the new study, Pao-Chi Liao and colleagues note that free-range chickens are those that have continuous access to fresh air, sunshine, and exercise, in contrast to chickens that are confined to cages. Demand for eggs from free-range chickens has increased steadily due to their supposed better nutrition qualities, including higher levels of certain healthy fats. But scientists suspect that free-range chickens may risk getting higher levels of exposure to environmental pollutants, particularly PCDDs and PCDFs, potentially toxic substances that are produced as by-products of burning waste. Also known as dioxins, these substances may cause a wide range of health problems in humans, including reproductive and developmental problems and cancer.
The scientists collected six free-range eggs and 12
regular eggs from farms and markets in
Jing-Fang Hsu, Chun Chen, Pao-Chi Liao. Elevated PCDD/F Levels and Distinctive PCDD/F Congener Profiles in Free Range Eggs. Journal of Agricultural and Food Chemistry, 2010; : 100603133421072 DOI: 10.1021/jf100456b
Thursday, June 17, 2010
salt is an important source of dietary iodine in the
Iodine helps prevent thyroid conditions such as goiter and neonatal iodine deficiency. Iodized salt has been sold in the since the 1920s, but Americans' iodine levels have decreased 50 percent over the past three decades, the experts noted.
Overall, Americans still receive sufficient iodine, but research suggests that many pregnant women may be iodine-deficient. Iodine is essential for proper synthesis of thyroid hormones, which are critical to normal and to prevent neurodevelopmental and neurobehavioral problems.
they agree with calls for reduced salt consumption in order to improve heart
health, the ATA members "recommend that all producers of commercially
prepared foods -- accounting for up to 70 percent of all salt consumed in the
The ATA recommends that women take 150 micrograms of iodine supplements daily during pregnancy and breast-feeding, and that all prenatal vitamin/mineral preparations contain 150 micrograms of iodine.
The American Thyroid Association has more about iodine deficiency.
By Amy Norton
Thursday, June 17, 2010
The findings do not prove that manganese -- which is present in food, water, air and soil -- is the reason for the slower development. But they are in line with the general understanding of manganese -- that small amounts in the diet are necessary for normal , while high amounts can be harmful.
What's new in this study is that it focused on manganese levels in the first few years of life, and whether there might be any effects of relatively low-level environmental exposure on the still-developing brain.
of what's been known about the health effects of elevated manganese levels has
come from studies of workers heavily exposed to the element on the job,
explained lead researcher Dr. Birgit Claus Henn, of
the Harvard in
In their study, Henn and her colleagues found that at the age of 12 months, children in either the bottom 20 percent or the top 20 percent for blood manganese levels had lower scores on a standard test of mental development than those whose manganese levels fell in between.
On the other hand, blood manganese at age 2 was not related to mental development scores. And while there was still a relationship between manganese levels at age 12 months and mental-development scores at , the connection was weaker, the researchers report in the journal Epidemiology.
Because the study is the first to look at blood manganese levels and brain development in children this age, the findings should be "interpreted cautiously," Henn told Reuters Health in an email.
However, she said, "if our findings are confirmed in other studies, the results suggest that both low and high manganese levels may have on neurodevelopment among young children, especially at 1 year of age, which may be a sensitive time point."
Manganese is a natural component of rock and soil, and people are routinely exposed to it through air, water and food, including grains, . It is also used in industry, mainly in steel production, and heavy occupational exposure to manganese can be toxic to nerve cells -- leading to symptoms such as difficulty concentrating and Parkinson-like problems like slowed movement and coordination problems.
For the , Henn and her colleagues followed 448 Mexican children from birth to age 3. Every six months, the children were given standard tests of mental development, including measures of vocalization and communication, memory and problem-solving -- such as tackling simple goals like reaching a toy.
In general, children in the bottom and top 20 percent for blood manganese at the age of 12 months scored about three points lower than their peers on the mental development.
According to Henn, that difference is akin to what has been seen when young children's of lead -- which is known to harm early brain development -- rise from 10 micrograms per deciliter of blood (mcg/dL) to 30 mcg/dL. ( of 10 mcg/dL or higher are considered to be potentially dangerous in young children.)
In this study, children in the bottom 20 percent for manganese at the age of 12 months had levels below roughly 20 mcg/L. In the top 20 percent, levels were higher than 28 mcg/L.
It is not certain that the manganese levels themselves were responsible for the relatively lower mental-development scores. The researchers did account for a number of other factors -- including blood lead levels and mothers' IQ and education levels -- and the connection remained.
However, Henn said that it is still possible that other factors, such as exposures to other environmental toxins, could explain the findings.
For now, she said, there are some steps parents can take to limit young children's exposure to manganese while ensuring that they also get enough of it. Manganese is present in some fertilizers and fungicides, for instance, so parents can try to limit their children's exposure to those products.
Henn also noted that while manganese levels in public drinking water are regulated, there can be high levels in well water. So avoiding that water source may be helpful.
On the other hand, Henn said, it is rare for people to be overexposed to manganese through food. So parents should make sure that their children get the healthful foods -- including whole grains and green, -- that contain manganese.
Epidemiology, July 2010.
By Steven Reinberg
Thursday, June 17, 2010
The gut of all mammals is populated with thousands of different types of bacteria, many of which are essential for developing a normal . But some of these bacteria also appear to have a part in the development of autoimmune diseases, the researchers explained.
While these experiments in mice are still preliminary, and animal studies often fail to produce similar results in humans, the findings could lead to a new way of looking at autoimmune diseases and might even result in new ways to treat or prevent them.
"It may eventually be possible to ameliorate or protect from human autoimmune diseases, arthritis and others, by treating with probiotics, antibiotics or other inhibitors of bacterial products," Mathis said.
For the study, Mathis and colleagues raised mice genetically prone to developing arthritis in a germ-free environment. These mice had fewer arthritis-causing antibodies than mice raised in a normal environment.
However, when the mice were put in a non-germ-free environment and had segmented filamentous bacteria placed in their stomachs, which is a common , the animals quickly started making antibodies and developed arthritis within four days, the researchers found.
"It is important to recognize that individuals do not 'catch' arthritis via bacterial infections," Mathis said. "Rather, the bacteria trigger a program to play out on a genetically susceptible background."
In this case, the bacteria cause the mice to make more of a type of white blood cell. The immune system reacts to these cells as threatening antibodies that in turn trigger rheumatoid arthritis, Mathis explained.
The notion that bacteria in the stomach can affect the development of autoimmune diseases such as rheumatoid arthritis is not that farfetched since these bacteria have been linked to irritable bowel syndrome and other such diseases.
For example, stomach ulcers are caused by bacteria and successfully treated with antibiotics.
Dr. Nancy Klimas, a professor of medicine at the University of Miami and a specialist in immunology, said that "this concept of the gut flora being important to human health is considered a rather radical concept, but it's been embraced more and more recently."
"You can cruise through your whole life with that little gene hanging out there and never ever have a health problem, but if you get certain acute infections those infections can trigger a huge and then you are left with this lifelong arthritis condition," she said.
In the future, changing the bacteria in the gut could prevent or treat some of these diseases, Klimas said. "This is an exciting new way of thinking, and it could certainly change the way we practice medicine."
Klimas speculated that the overuse of antibiotics may be changing the bacterial environment in the stomach and causing drastic increases in diseases.
"This raises the possibility that when you see illnesses that seem to be inflammatory or autoimmune, this flora of the gut may well be playing a role," she said.
For more on arthritis, visit the U.S. National Library of Medicine.
By Mike Stobbe
AP Medical Writer
The Associated Press
Thursday, June 17, 2010
In 2008, ERS saw an estimated 1 million visits from people abusing prescription or over-the-counter medicines mostly painkillers and sedatives. That was about the same number of visits from those overdosing on heroin, cocaine and other , according to a government report released Thursday.
Only five years earlier, illegal drug visits outnumbered those from legal medications by a 2-to-1 margin.
"It's a pretty startling jump," Delany said. He led a team that worked with the Centers for Disease Control and Prevention on the report.
Painkillers and sedatives clearly drove the trend. ER visits for the painkillers oxycodone and hydrocodone more than doubled from 2004 to 2008. And cases from one kind of tranquilizer nearly doubled.
estimates are based on emergency room data from more than 200
Health officials are not sure why painkiller abuse rose so dramatically. But the number of prescriptions has been increasing, so some of those who ended up in ERs may have gotten their medicine legally.
The authors did not estimate how many of the ER patients died. A CDC report last year found that the rate of drug-related deaths roughly doubled from the late 1990s to 2006, and most of the increase was attributed to prescription opiates such as the painkillers methadone, Oxycontin and Vicodin.
The use of painkillers has grown in recent years as doctors tried to correct the traditional undertreatment of pain, and pharmaceutical companies ramped up marketing of new pain medications.
many doctors and patients don't fully recognize the medications' dangers, said
Susan Foster, a vice president at
"People believe they're safer because they're prescribed by doctors and approved by the FDA," she said.
The report is being published this week in a CDC publication, Morbidity and Mortality Weekly Report.
Thursday, June 17, 2010
ScienceDaily (June 17, 2010) Virginia Commonwealth University researchers have discovered a mechanism by which an enzyme regulates gene expression and growth in melanoma cells, a finding that could someday lead to more effective drugs to attack cancers and make them more treatable.
Melanoma, the most serious type of skin cancer, is highly resistant to current therapeutic strategies for reasons that are not well understood. New research at VCU suggests that an enzyme discovered in 2003 might be used to target a specific genetic component that helps to regulate gene expression and defends melanoma cells against treatment.
The findings are reported online in the Proceedings of the National Academy of Sciences.
"By selectively and specifically targeting molecules for degradation that serve as gatekeepers for cancer growth, progression and resistance to therapy, it may be possible to turn the cancer cells' defense into an offense that can be used as an effective approach to destroy the tumor," said Paul B. Fisher, Ph.D., professor and chair of the Department of Human and Molecular Genetics and director of the VCU Institute of Molecular Medicine in the VCU School of Medicine.
Several years ago, Fisher led a team of scientists at
Fisher, now at VCU, and colleagues report that hPNPaseold-35 selectively targets and degrades a genetic component known as microRNA-221. MicroRNAs are short genetic components that act like a volume control knob to regulate the production of defined proteins in cells.
MicroRNAs regulate the expression of more than a third of human genes. In recent years, they have been recognized as causing over- or under-expression of genes linked to the majority of cancers and other diseases. Researchers are exploring microRNAs' roles to understand how they could be used as potential targets for therapies.
The work by Fisher's group indicates that showering the cell with the hPNPaseold-35 enzyme preferentially degrades microRNA-221, a microRNA that is elevated in multiple cancers including melanoma and which regulates gene expression that promotes the cancer cells' ability to thrive and spread. MicroRNA-221 also endows melanoma and other cancers with the capacity to resist chemotherapy.
"The present study provides the first observation that microRNAs may be regulated by selective degradation, providing an entry point for developing novel approaches for the therapy of melanoma and other cancers, Fisher said.
The VCU study also found that interferon-beta, a treatment for melanoma and other cancers, induces cells to produce the enzyme while also interfering with the ability of microRNA-221 to perform. Fisher said this provides one possible explanation for how interferon-beta suppresses growth of melanoma cells.
The work was supported by grants from the National Institutes of Health and the Samuel Waxman Cancer Research Foundation.
Fisher, who also is the first incumbent of the Thelma Newmeyer Corman Endowed Chair in Cancer Research at the VCU Massey Cancer Center, led the investigative team at the VCU School of Medicine, which included Swadesh K. Das, Ph.D., a postdoctoral fellow; Upneet K. Sokhi, graduate student; Sujit K. Bhutia, Ph.D., postdoctoral fellow; Belal Azab, graduate student; Zhao-zhong Su, Ph.D., associate professor in VCU's Department of Human and Molecular Genetics; and Devanand Sarkar, MBBS, Ph.D., assistant professor the Department of Human and Molecular Genetics and member of the VCU Institute of Molecular Medicine.
Das, U. K. Sokhi, S. K. Bhutia,
B. Azab, Z.-z. Su, D. Sarkar,
P. B. Fisher. Human polynucleotide phosphorylase
selectively and preferentially degrades microRNA-221 in human melanoma cells.
Proceedings of the
By Amy Norton
Thursday, June 17, 2010
While exercise can trigger in some people, there is also evidence that physically active asthmatics tend to have better overall asthma control than their sedentary counterparts. But whether that signals a benefit of exercise, per se, has been unclear.
the new study, Shilpa Dogra
and colleagues at
The researchers had 18 study participants go through three months of supervised exercise training, where they worked out aerobically three times per week -- with activities like jogging, walking on a treadmill or pedaling on a stationary bike -- and performed strengthening exercises once a week.
The exercisers then continued to work out on their own for another three months.
The rest of the study participants served as a control group, maintaining their usual lifestyle habits.
After the initial three months, Dogra's team found, the exercise group improved its average score on a standard questionnaire gauging asthma-symptom control -- a change that moved the group from the category of "relatively well-controlled" to "well-controlled."
Similarly, the exercisers reported gains in a questionnaire on asthma-related -- which measures, for example, how much a person's symptoms limit his or her daily activities or affect emotional well-being.
The exercise group also maintained those gains over the three months of home workouts, whereas the control group's scores remained largely unchanged during the study period.
Previous studies have suggested that exercise can improve asthma-related quality of life. But this is the first to show that it may also aid symptom control, Dogra told Reuters Health in an email.
And while the study used a supervised program to ensure that participants were following a specific regimen, Dogra said that adults with asthma can generally perform similar moderate exercise on their own.
In their study, Dogra and her colleagues found little evidence of harm from exercise. One person in the exercise group had an that required hospitalization, but it did not occur during physical activity and seemed to be unrelated to the workout regimen.
The study had a number of limitations, including its small size and a lack of objective measures of asthma control.
On the other hand, Dogra pointed out that there are well-established benefits of regular exercise -- including weight control and a reduced risk of -- that people with or without asthma stand to gain. In fact, she noted, adults with asthma have been shown to have higher-than-average rates of heart disease and obesity, underscoring the of physical activity.
There is still a need for much more research into asthma and exercise, according to Dogra. Among the remaining questions, she said, are whether children with asthma can gain similar benefits from exercise, and whether there are "optimal" types of activities for aiding asthma control.
Thursday, June 17, 2010
ScienceDaily (June 17, 2010) A multi-institutional research team has found that rare variants in the gene coding an enzyme that controls the activity of a key immune cell occur more frequently in individuals with autoimmune disorders like rheumatoid arthritis and type 1 diabetes. Their report, which will appear in the journal Nature and is receiving early online release, identifies a pathway that could be a therapeutic target and may present a model for future investigations of the role of rare gene variants in common disorders.
"Pathways that involve rare disease-associated
variants may point the way to therapies," explains Shiv
Pillai, MD, PhD, of the
Earlier research conducted by Pillai's
team, in collaboration with investigators at the
Most studies searching for genetic contributions to common diseases have been genome-wide association studies (GWAS), which scan key markers across participants' genomes to find variations that are more frequent in those affected by a particular disorder. These scans have identified some common variants associated with conditions such as heart disease, cholesterol levels, type 2 diabetes, and some autoimmune disorders; but in general the contribution of these variants to disease susceptibility has been very small. GWAS approaches have not linked any variants in SIAE to human autoimmunity; however, since such studies do not scan each base pair in every gene, they cannot find variants that occur rarely in the general population but more frequently in affected individuals.
To more fully investigate the possible contribution of rare SIAE variants to human autoimmunity, the researchers completely scanned the protein-coding portions of the SIAE gene in blood samples from a total of 923 individuals with common autoimmune disorders and 648 control participants. Variants that interfered with either the activity or the secretion of the enzyme were found in 24 autoimmune participants and 2 of the controls, indicating that these changes were almost nine times more common in patients with autoimmune disease than in controls. One variant only prevented the secretion of SIAE if inherited from both parents, but the other 11 identified variants interfered with the enzyme's activity when only a single gene copy was altered.
"While loss-of-function variants in SIAE itself
account for only about 2 or 3 percent of autoimmune cases, Pillai
explains, "we are actively investigating other genes in this pathway that
may be defective in a larger percentage of patients. We're also identifying
subsets of patients with SIAE defects who may be candidates for several
approaches to alleviate or even correct the defects." Pillai
is an associate professor of Medicine at
Co-lead authors of the Nature paper -- all from
Ira Surolia, Stephan P. Pirnie, Vasant Chellappa, Kendra N. Taylor, Annaiah Cariappa, Jesse Moya, Haoyuan Liu, Daphne W. Bell, David R. Driscoll, Sven Diederichs, Khaleda Haider, Ilka Netravali, Sheila Le, Roberto Elia, Ethan Dow, Annette Lee, Jan Freudenberg, Philip L. De Jager, Yves Chretien, Ajit Varki, Marcy E. MacDonald, Tammy Gillis, Timothy W. Behrens, Donald Bloch, Deborah Collier, Joshua Korzenik, Daniel K. Podolsky, David Hafler, Mandakolathur Murali, Bruce Sands, John H. Stone, Peter K. Gregersen & Shiv Pillai. Functionally defective germline variants of sialic acid acetylesterase in autoimmunity. Nature, June 16, 2010 DOI: 10.1038/nature09115
Wednesday, June 16, 2010
Wednesday, June 16, 2010
ScienceDaily (June 16,
2010) Women who drink
Scandinavian boiled coffee, which chemically resembles French press and
Turkish/Greek coffee, more than four times a day run a lower risk of developing
breast cancer than women who drink coffee less than once a day. This is shown
by Lena Nilsson and her associates at
A major difference between boiled and filtered coffee is that the boiled version contains up to 80 times as much coffee-specific fatty acids. These fatty acids have previously been shown in animal experiments to inhibit the growth of cancer.
By comparing filtered coffee and boiled coffee in the Vδsterbotten Intervention Project (64,603 participants), researchers at Umeε University have been able to show for the first time that various brewing techniques can lead to different risk patterns for cancer. For total cancer, prostate cancer, colorectal cancer, and many other less common forms of cancer, there was no correlation.
Among women who drank boiled coffee more than four times a day there was a lowered risk of breast cancer compared with women who drank coffee less than once a day. Among women who drank filtered coffee there was an increased risk for early breast cancer (under 49 years old) and a decreased risk for late breast cancer (over 55 years old). Boiled-coffee drinkers, but not filtered-coffee drinkers, also had an increased risk of pancreatic cancer and lung cancer among men.
The study, recently published in the scientific journal Cancer Causes and Control, is the first in the world to compare the consumption of coffee prepared with two brewing techniques in regard to cancer.
Wednesday, June 16, 2010
Children exposed to the toxic gas and to dog allergen during their first year of life were nearly five times as likely to have asthma at age 7 compared to kids with neither exposure, while dog allergen plus secondhand smoke nearly tripled the risk.
studies of asthma in children have looked at single risk
factors, but in the real world, people often face multiple exposures, Dr. Chris Carlsten
To investigate the interplay between such exposures, the researchers looked at 380 children at high risk for asthma who had been followed since infancy. The children were considered to be at high risk because they had at least one close relative with asthma, or at least two close relatives with allergies.
The children and their families had been participating in a study of whether reducing exposure to potentially allergy-promoting factors, such as household dust and secondhand smoke, might reduce their risk of developing asthma or allergies.
In the current analysis, the researchers compared children's exposure to dog allergens, secondhand smoke (measured by checking their urine for the nicotine byproduct cotinine, as well as their umbilical cord blood at birth), and nitrogen dioxide, which is found in automobile exhaust and produced by other types of fuel burning.
At age 7, 71 of the children (19 percent) had asthma, while 141 (almost 41 percent) had "bronchial hyperreactivity" -- twitchy airways in which the tiny tubes of the airways tighten up more intensely in response to a given stimulus (for example, cold air) than they would in a person without the condition, causing difficulty breathing.
Owning a dog was the only factor that independently increased asthma risk, the researchers found; individual exposure to air pollutants didn't up risk.
However, combinations of exposures did sharply increase risk. For example, 7-year-olds exposed to dogs in infancy as well as to nitrogen dioxide were 4.8 times as likely to have asthma as children with neither exposure, while the combined risk for dog and secondhand smoke exposure was 2.7 times greater.
The risk with multiple exposures was even greater for the subset of children who had "atopy" -- the inherited tendency to develop allergic illness, such as eczema, hay fever or asthma; and for these children, early exposure to secondhand smoke alone tripled risk of bronchial hyperresponsiveness.
While the exact mechanism through which these exposures could increase asthma risk isn't known, gas and particles could damage the lining of the airways and trigger inflammation, the researchers say.
Wednesday, June 16, 2010
ScienceDaily (June 16, 2010) Low-salt foods may be harder for some people to like than others, according to a study by a Penn State College of Agricultural Sciences food scientist. The research indicates that genetics influence some of the difference in the levels of salt we like to eat.
Those conclusions are important because recent, well-publicized efforts to reduce the salt content in food have left many people struggling to accept fare that simply does not taste as good to them as it does to others, pointed out John Hayes, assistant professor of food science, who was lead investigator on the study.
Diets high in salt can increase the risk of high blood pressure and stroke. That is why public health experts and food companies are working together on ways to help consumers lower salt intake through foods that are enjoyable to eat. This study increases understanding of salt preference and consumption.
The research involved 87 carefully screened participants who sampled salty foods such as broth, chips and pretzels, on multiple occasions, spread out over weeks. Test subjects were 45 men and 42 women, reportedly healthy, ranging in age from 20 to 40 years. The sample was composed of individuals who were not actively modifying their dietary intake and did not smoke cigarettes. They rated the intensity of taste on a commonly used scientific scale, ranging from barely detectable to strongest sensation of any kind.
The study, a collaboration between Hayes and Valerie Duffy, professor of allied health science and Bridget S. Sullivan, Master's graduate, University of Connecticut, appeared in the June 16 issue of Physiology & Behavior.
"Most of us like the taste of salt. However, some individuals eat more salt, both because they like the taste of saltiness more, and also because it is needed to block other unpleasant tastes in food," said Hayes.
"Supertasters, people who experience tastes more intensely, consume more salt than do nontasters. Snack foods have saltiness as their primary flavor, and at least for these foods, more is better, so the supertasters seem to like them more."
However, supertasters also need higher levels of salt to block unpleasant bitter tastes in foods such as cheese, Hayes noted. "For example, cheese is a wonderful blend of dairy flavors from fermented milk, but also bitter tastes from ripening that are blocked by salt," he said. "A supertaster finds low-salt cheese unpleasant because the bitterness is too pronounced."
Hayes cited research done more than 75 years ago by a chemist named Fox and a geneticist named Blakeslee, showing that individuals differ in their ability to taste certain chemicals. As a result, Hayes explained, we know that a wide range in taste acuity exists, and this variation is as normal as variations in eye and hair color.
"Some people, called supertasters, describe bitter compounds as being extremely bitter, while others, called nontasters, find these same bitter compounds to be tasteless or only weakly bitter," he said. "Response to bitter compounds is one of many ways to identify biological differences in food preference because supertasting is not limited to bitterness.
"Individuals who experience more bitterness also perceive more saltiness in table salt, more sweetness from table sugar, more burn from chili peppers, and more tingle from carbonated drinks."
Supertasters live in a neon food world, Hayes noted. Nontasters, on the other extreme, live in a pastel food world.
"Interestingly, nontasters may be more likely to add salt to foods at the table because they need more salt to reach the same level of perceived saltiness as a supertaster," he said. "However, most of the salt we consume comes from salt added to processed foods and not from the salt shaker."
The U.S. Department of Agriculture and the National Institutes of Health supported this work.
Hayes et al. Explaining variability in sodium intake through oral sensory phenotype, salt sensation and liking. Physiology & Behavior, 2010; 100 (4): 369 DOI: 10.1016/j.physbeh.2010.03.017
European Respiratory Journal, online June 7, 2010.
By Serena Gordon
Wednesday, June 16, 2010
WEDNESDAY, June 16 (HealthDay News) -- may have something else to be concerned about -- an increased risk of cancer, according to a new consensus report produced by experts recruited jointly by the American Cancer Society and the American Diabetes Association.
Other research has suggested that some , such as certain insulins, may also be associated with the development of some cancers. But the evidence isn't conclusive, and it's difficult to tease out whether the insulin is responsible for the association or other associated with diabetes could be the root of the link.
"There have been some epidemiological studies that suggest that individuals who are obese or who have [high levels of insulin] appear to have an increased prevalence of , but it's a complex issue because the association is not true for all cancers," explained Dr. David Harlan, director of the Diabetes Center of Excellence at the University of Massachusetts Memorial Medical Center in Worcester, and one of the authors of the consensus report.
"So, there's some smoke to suggest an association -- but no clear fire," he added.
As for the possible insulin-and-cancer link, Harlan said that because a weak association was found, it's definitely an area that needs to be pursued further. But, he said, that doesn't mean that anyone should change the way they're managing their diabetes.
"Our greatest concern is that individuals with diabetes might choose not to treat their diabetes with insulin or a particular insulin out of concern for a malignancy. The risk of is a far greater concern," noted Harlan. "It's like when someone decides to drive across the country because they're afraid to fly. While there is a slight risk of dying in a plane crash, statistically it's far riskier to drive."
The consensus report is published in the July/August issue of CA: A Cancer Journal for Clinicians.
The experts found evidence of an association between diabetes and an increased risk of liver, pancreas, endometrial, colon/rectal, breast and bladder cancer. Interestingly, they found evidence that diabetes is associated with a reduced risk of prostate cancer.
a strong consensus that there is a link between diabetes and cancer, and there
are some very plausible biologic links," said the report's lead author,
Dr. Edward Giovannucci, a professor of nutrition and
epidemiology at the Harvard in
And, he said, there's definitely an overlap in some of the risk factors for both type 2 diabetes and cancer, especially obesity.
The panel also found research that suggests the commonly used type 2 diabetes medication, metformin, might offer users some protection against cancer. Giovannucci said this may be because the drug reduces insulin resistance and lowers the need for additional insulin, or that metformin may act on cells in other direct or indirect ways.
He said it's not always the most popular message, but to lower the risk of cancer, it's important to reduce your body weight, exercise, improve your diet and avoid smoking.
Alice Bender, the nutrition communications manager for the American Institute for (AICR), said she wasn't surprised by the findings in the consensus report. "What we're seeing is that there are a lot of commonalities between chronic diseases and their risk factors," she said.
Bender agreed with Giovannucci's suggestions and said the AICR recommends three guidelines for everyone: a healthy body weight; be physically active for at least 30 minutes a day; and, eat a mostly plant-based diet that's healthy and varied.
"At least for cancer, we know that each factor independently lowers the risk of certain cancers, but all three done together are even more powerful. And, I suspect that's the case for preventing type 2 diabetes also," she said.
Bender also emphasized the need to moderate the consumption of alcohol, which means no more than one drink per day for women and no more than two drinks per day for men.
Learn more about potentially preventing cancer with diet and exercise from the American Cancer Society.
Wednesday, June 16, 2010
WASHINGTON (Reuters) More Americans are exercising but rates of obesity and smoking have not changed, according to the latest government data.
But 34.7 percent claimed in 2009 they engage in regular leisure physical activity, up from 31.9 percent in 2008. And 39.8 percent said they had been tested for the , slightly more than 38.7 percent in 2008.
The CDC also recommends that every adult get an HIV test. The CDC estimates that about 1 million Americans are infected with the human immunodeficiency virus that causes AIDS, but more than 20 percent have not been tested and do not know it.
· The prevalence of obesity among adults aged 20 and over has increased from 19.4 percent in 1997 to 28 percent in 2009.
· In 2009, 9 percent of adults 18 and over had diabetes, up from 8.2 percent in 2008 and 5 percent in 1997.
· 20.6 percent of adults smoked, about the same as in 2008.
· Nearly 23 percent of adults had at least one day of binge drinking in 2009, defined as having five or more drinks in a day.
· Just over 4 percent of all Americans said they had an asthma attack in the past year.
(Editing by Cynthia Osterman)
Wednesday, June 16, 2010
WEDNESDAY, June 16 (HealthDay News) -- A new study has found a link between air pollution and breathing-related disruptions during sleep.
Conducted by the Harvard School of Public Health and Brigham & Women's Hospital, the authors say this the first attempt to document a link between exposure to pollution and sleep-disordered breathing.
Breathing-related sleep disruptions come in several forms, of which the best known is . It causes people to repeatedly wake up when their airways constrict and breathing is cut off. In many cases, sufferers don't realize they have the condition, which can contribute to the development of heart disease and stroke.
the study, researchers tried to discover if air pollution -- which irritates
the airways -- has anything to do with sleep disruptions, which affect an
estimated 17 percent of adults in the
study authors pored over data from the Sleep Heart Health Study, which examined
the heart health and of more than 6,000
people between 1995 and 1998. They then compared those patterns to
Environmental Protection Agency (EPA) air pollution data on seven cities:
The researchers analyzed data on more than 3,000 people and adjusted for factors such as age, gender, smoking and temperature so they wouldn't throw off the results.
They found that incidents of sleep apnea and low levels of oxygen during sleep went up as the temperature rose during all seasons of the year. Sleep-disordered breathing also rose during the summer as air pollution worsened.
Particles of pollution "may influence sleep through effects on the central nervous system, as well as the upper airways," wrote co-author Antonella Zanobetti in a news release, noting that the exact mechanism is unclear. "These new data suggest that reduction in air pollution exposure might decrease the severity of such sleep disruptions."
The study, funded by the U.S. National Heart Lung and Blood Institute, the EPA and the U.S. National Institute of Environmental Health Sciences, appeared online June 14 in the American Journal of Respiratory and Critical Care Medicine.
For more about sleep apnea, try the U.S. National Library of Medicine.
Wednesday, June 16, 2010
In the study, researchers failed to see a significant association between eating eggs occasionally or almost daily and the development of type 2 diabetes in nearly 4,000 older men and women.
eggs are a key source of dietary cholesterol, they also contain a number of
other potentially beneficial nutrients, Dr. Luc Djousse
of Brigham and Women's
eggs could serve as a readily available and inexpensive source for vitamins,
proteins and other nutrients in the
To investigate, the researchers looked at 3,898 men and women participating in the Cardiovascular Health Study. All were at least 65 years old when they enrolled in the study. During follow-up, which averaged about 11 years, 313 people developed type 2 diabetes, which is closely linked to being overweight as well as poor diet and lack of exercise.
Djousse and his colleagues found no relationship between any amount of egg consumption and increased 2 diabetes. They also found no link between dietary cholesterol overall and diabetes risk. While men in the top category of egg consumption, meaning they ate eggs almost daily, were at increased type 2 diabetes risk, this increase wasn't statistically significant, meaning it could have been due to chance.
Other studies that have linked eggs to diabetes have found an association with very , the researchers note, generally for eating seven or more eggs a week. On average, participants in this study ate less than one egg a week, the researchers add, so there may not have been enough people with very high egg intakes to establish whether this was harmful.
Nevertheless, they conclude, the current investigation doesn't back any significant relationship between egg consumption and type 2 diabetes.
By Amanda Gardner
Wednesday, June 16, 2010
WEDNESDAY, June 16 (HealthDay News) -- In describing a set of concrete symptoms for "" for the first time, British researchers have also determined that only about 2 percent of men aged 40 to 80 suffer from the condition, far less than previously thought.
Male menopause, also called "andropause" or late-onset hypogonadism, supposedly results from declines in testosterone production that occur later in life, but there has been some debate on how real the phenomenon is, the study authors noted.
"Some indeed suffer from [male menopause]. It is a genuine syndrome, but much less common than previously assumed," concluded Dr. Ilpo Huhtaniemi, senior author of a study published online June 16 in the New England Journal of Medicine.
"This is important because it demonstrates that genuine symptomatic androgen deficiencies [androgens are ] is less common than believed, and that only the right patients [should] get androgen treatment," added Huhtaniemi, a professor of reproductive endocrinology in the department of surgery and cancer at Imperial College London.
Many men have been taking to combat the perceived effects of aging, even though it's not clear if taking these supplements help or if they're even safe. The result has been mass confusion, not only as to whether male menopause exists but also how to treat it.
lot of people abuse testosterone who shouldn't and a lot of men who should get
it aren't," said Dr. Michael Hermans, an
associate professor of surgery in the Texas A&M Health Science Center
College of Medicine and chief of the section of andrology,
male sexual dysfunction and male infertility at Scott & White in
Of 32 possible symptoms, only nine were linked with decreased testosterone levels. Three were physical -- not being able to engage in strenuous physical activity, not being able to walk more than 1 kilometer and not being able to bend over or kneel -- and three were psychological -- low energy, sadness and fatigue.
Three sexual symptoms -- less frequent morning erections, lower sex drive and erectile dysfunction -- were more robustly related to testosterone levels.
But even with this new diagnostic criteria, the challenge of treating men with sexual and other symptoms of male menopause is still far from straightforward.
symptoms that are associated with hypogonadism are
not necessarily going to be treated by testosterone therapy," pointed out
Dr. Natan Bar-Chama, director of male reproductive
medicine and an associate professor of urology at
"Just because an older guy comes in and says he has a bad sex life, you don't automatically give him testosterone," Hermans added.
Tuesday, June 15 2010
By Kate Kelland
Tuesday, June 15 2010
LONDON (Reuters) who have higher levels of vitamin B6 and certain essential proteins in their blood have a lower risk of getting lung cancer than those deficient in these nutrients, according to study by .
Scientists at the International Agency for Research on Cancer (IARC) said that although they had not found a causal link, the results may be a clue to why some smokers never get lung cancer and some non-smokers or do.
Lung cancer is the most common form of the disease in the world and 90 percent of all cases are caused by cigarette smoking. It kills 1.2 million people a year.
About 10 to 15 percent of smokers develop lung cancer -- although they often die of other smoking-related causes like , stroke or emphysema. Lung cancer is also known to kill people who never smoked or who gave up years ago.
The IARC study, which looked at around 900 , found a link to low levels of vitamin B6 and an amino acid called methionine, found in protein like meat, fish and nuts. B6 is also found in meat, nuts, vegetables and bananas.
"What we have found is that these two things are strong markers of lung , but we have not shown they are causing that rise in risk," said Paul Brennan of the Lyon-based IARC, who led the study and published its findings in the Journal of the American Medical Association (JAMA) on Tuesday.
"This indicates that diet may have an important role in lung , but it's still a little premature to say simply that if you change your diet and eat more foods with these vitamins then you'll change your future lung cancer risk."
Nutrients Key To DNA Health
Brennan said the change in risk of lung cancer linked to B6 and methionine levels was the same for all three groups, although of course the overall risk of getting the disease was much higher in the smokers to start with.
"For the two nutrients together, the risk reduction was about 60 percent," he said. "Obviously if you had a very high risk because you smoke, then a 60 percent reduction of that is quite important, although not as important as quitting smoking."
A Swedish study in 2005 found that women with high levels of vitamin B6 had a lower risk of developing colorectal cancer.
"Basically, these B vitamins and nutrients are all involved in the pathway which is responsible for the creation and maintenance of DNA," Brennan said. "So obviously you would want that pathway to work as well as possible."
(Editing by Peter Graff)
Tuesday, June 15 2010
Deposits of calcium in blood vessels have been linked to blood vessel blockages and and stroke. Because of this, many women have concerns about taking calcium pills to maintain bone strength, according to the authors of a report published in the June 16 issue of the journal Menopause.
For this study, the researchers used cardiac imaging to measure CAC levels in 754 women who were aged 50 to 59 at the time of enrollment. CAC scores were similar among women who took calcium (1,000 milligrams of elemental calcium daily) plus vitamin D3 (400 International Units daily) for an average of seven years and women who took a placebo.
"This study provides reassuring evidence that moderate doses of do not increase calcium deposition in the coronary arteries. Thus, women need not avoid these supplements and sacrifice bone health due to concern about such a risk," Dr. JoAnn Manson, chief of preventive medicine at in Boston, said in a hospital news release.
The U.S. National Institute of Arthritis and Musculoskeletal and Skin Diseases has more about calcium and vitamin D.
Tuesday, June 15 2010
In a study of nearly 1,000 Italian adults with and without pancreatic cancer, researchers found that those whose diets were high in so-called "glycemic index" showed a greater risk of the cancer than participants whose diets were relatively .
Glycemic index refers to how rapidly a food causes blood sugar to rise. High-glycemic index foods, like white bread and potatoes, tend to spur a quick elevation in , while low-glycemic index foods, such as lentils, soybeans, yogurt and many high-fiber grains, create a more gradual increase in blood sugar.
In the new study, researchers found no relationship between the total carbohydrates in participants' diets and their risk of pancreatic cancer. And when they focused on fruit intake, higher consumption was related to a lower risk of the disease.
In contrast, there was a relationship between increased and higher intakes of sugar, candy, honey and jam. This suggests that sugary, processed carbohydrates -- rather than carbs like fiber-rich grains, fruits and vegetables -- may be particularly linked to pancreatic cancer, the researchers report in the Annals of Epidemiology.
Pancreatic cancer is a relatively uncommon but particularly , with only about 5 percent of patients surviving for five years. Early on, the disease causes no symptoms, or only vague problems like indigestion, so it is rarely caught before it has advanced.
Researchers, therefore, are particularly interested in discovering modifiable risk factors for the cancer. Studies so far have identified smoking and long-standing diabetes as risk factors. But the role of diet remains unclear.
Some studies have found links between pancreatic cancer and high intakes of red meat and dietary fat, while others have failed to find such a relationship. Findings on carbohydrates and sugar have been similarly inconsistent.
the current study, researchers led by Marta Rossi of the Mario Negri Institute for Pharmacological Research in
Each patient was compared with two cancer-free adults the same age and sex.
Overall, Rossi's team found, the one-third of participants with the highest-glycemic index diets were 78 percent more likely to have pancreatic cancer than the third with the lowest-glycemic index diets. The middle third fell in between, with a 56 percent higher risk.
The researchers then looked at certain select sources of carbohydrates, including fruit and a category that included sugar, candy, honey and jam. High intakes of the latter, it turned out, were linked to an increased risk of pancreatic cancer.
Rossi and her colleagues accounted for certain other factors, including participants' weight, smoking history and any diabetes diagnoses -- suggesting that higher rates of smoking, obesity or diabetes do not explain the link between pancreatic cancer and sugary diets.
According to the American Cancer Society, the average adult has just over a 1 percent chance of developing pancreatic cancer in his or her life. So even the 78 percent increase in that one percent risk linked to high-glycemic index diets in this study would translate into a small absolute risk for an individual.
The study does not show that sugary foods cause pancreatic cancer, but it is possible that such diets could contribute to pancreatic risk, according to the researchers. Even in the absence of diabetes, such foods influence the body's secretion of the . And insulin encourages the growth and division of cells in the pancreas -- raising the possibility that the hormone could encourage the growth and spread of pancreatic cancer cells.
More research is needed, however, to show whether this is the case, they write.
Annals of Epidemiology, June 2010.
By Randy Dotinga
Tuesday, June 15 2010
TUESDAY, June 15 (HealthDay News) -- A new study shows that people with high levels of a B vitamin are half as likely as others to develop . But while the reduction in risk is significant, this doesn't mean that smokers should hit the vitamin aisle instead of quitting.
While the study links vitamin B6, as well as one amino acid, to fewer , it doesn't conclude that consuming the nutrients will reduce the risk. Future research is needed to confirm that there's a cause-and-effect relationship at work, not just an association, researchers said.
The findings appear in the June 16 issue of the Journal of the American Medical Association.
The researchers examined a study of almost 520,000 Europeans who were recruited between 1992 and 2000. They compared 899 who developed lung cancer by 2006 to 1,770 similarly matched people who hadn't developed the disease.
The researchers found that those with the highest levels of vitamin B6in their blood were 56 percent less likely to have developed lung cancer than those with the lowest levels. There was a similar difference -- a 48 percent decline -- for those with the highest levels of methionine, an amino acid, compared to those with the lowest concentrations.
reductions in risk held up for both smokers and non-smokers, said study co-author
Paul Brennan, a researcher with the World Health Organization's International
Agency for Research on Cancer in
Normally, as many as 15 percent of lifetime smokers will develop lung cancer, but fewer than 1 percent of those who never smoke do, Brennan said.
reduction in risk is impressive and it could be a step forward toward greater
understanding of how food and medications may prevent lung cancer, said the
Both vitamin B6and methionine are important to good health and available in supplement form.
Vitamin B6helps the body protect itself against disease and process glucose (sugar) in the blood; it's found in foods such as bananas, fish, chicken, potatoes, peanut butter and . Methionine is found in foods such as red meat, fish and beans. People can suffer from methionine deficiency, which can cause medical problems, including liver damage.
However, the experts said that it's possible that some other factor related to the vitamin and amino acid is affecting the lung cancer rate, such as a specific food that they are found in.
If vitamin B6and methionine really do lower the , researchers aren't sure of the mechanism. However, both nutrients are linked to the body's construction of DNA, and lowered levels might lead to errors, Brennan theorized.
So should you take supplements to boost the levels of vitamin B6and methionine, just in case? No, Brennan said. "There is no evidence that vitamin supplements may reduce and even some evidence that they may increase cancer risk," he said.
a related study, also published in the same issue of JAMA, researchers
The team surveyed 437 patients diagnosed with early-stage lung cancer, 386 of whom were eligible for tumor-removing surgery. A total of 241 patients underwent the surgery within four months of their diagnosis.
According to the study, patients were less inclined to opt for surgery if they felt that their diagnosis was less than 90 percent certain; if they felt that their quality of life would be worse in one year because of the surgery; or because they felt there had been poor quality communication about their cancer care. Black patients who had two or more co-existing illnesses or who lacked a regular source of care also tended to opt for surgery less often, as did lower-income compared to more affluent whites, the report said.
There's more on nutrition and cancer risk at the U.S. National Cancer Institute.
By Maggie Fox
Health and Science Editor
Tuesday, June 15 2010
WASHINGTON (Reuters) New U.S. nutritional guidelines should focus on keeping Americans from getting even fatter, experts said on Tuesday, with an emphasis not only on healthy foods but on finding ways to help Americans eat better and exercise more.
This is especially true for children, among whom obesity rates have tripled in the past 30 years.
The report from more than a dozen experts of the Advisory Committee, was released at http://www.cnpp.usda.gov/DGAs2010-DGACReport.htm for a 30-day public comment period.
HHS and the U.S. Department of Agriculture will then draw up new guidelines, as required by Congress every five years.
guidelines set standards for
They also suggest decreasing sodium from the current level of less than 2,300 milligrams a day to less than 1,500 and said Americans need to phase out processed grains like white flour.
"There is a call for drinking fewer sugar-sweetened beverages. There is a call to decrease saturated fat from 10 percent to 7 percent of daily calories. It is sort of a graduated approach to decrease the of the American public," Slade-Sawyer said.
And it veered into public policy, something avoided in past reports.
"The daunting public health challenge is to accomplish population-wide adoption of healthful dietary patterns within the context of powerful influences that currently promote unhealthy consumer choices, behaviors, and lifestyles," the report said.
"For all Americans, especially those with low income, create greater financial incentives to purchase, prepare, and consume vegetables and fruit, whole grains, seafood, fat-free and low-fat milk and , lean meats, and other healthy foods," the report added.
It suggested development of fish farms to help people afford fish.
(Editing by Julie Steenhuysen and Vicki Allen)
By Ed Edelson
Tuesday, June 15 2010
research was conducted with twins to try to eliminate the possible effect of
genetics as much as possible, explained Dr. Jun Dai, an assistant professor of
nutrition and epidemiology at
The Mediterranean-style diet differs from standard American fare by featuring a low content of and high intake of fish, fruits, vegetables, olive oil, nuts and cereals, with a glass or two of wine a day. Many studies have linked it to a lower .
This latest research included 276 male twins, some identical, some fraternal; fraternal twins share 50 percent of their genes while identical twins share 100 percent. The researchers measured their heart rate variability, the variation in the time interval between heartbeats in everyday life. "Higher variability reflects good ," Dai explained.
The men in the study reported their food preferences on a questionnaire, and were scored by how closely their intake matched that of a . Their heart activity was measured and recorded with a portable, battery-operated electrocardiogram monitor.
The study found that higher Mediterranean diet scores were related to greater variability in heart rate. On a nine-point scale, every one-unit difference was associated with a greater heart rate variability of 3.9 percent to 13 percent. This equates to a 9 percent to 14 percent of heart-related death, the report said.
The results can't be generalized to everyone, because all the twins in the study were white males, the report said. "But this should encourage more people to choose a healthy diet and others in the health-care system to promote it," Dai said.
rate variability is well-known to be related to cardiac health, said Dr. Gordon
F. Tomaselli, chief of cardiology at
The results have an inevitable range of uncertainty, since they depended on self-reports of dietary habits, and the physical link between diet and heart rate variability is not completely clear, Tomaselli said. "But all other things being equal, a more Mediterranean-like diet appears to swing the balance to the healthy side of the autonomic system," he added.
Tomaselli said he tries to steer people toward a Mediterranean-type diet, without necessarily using the term. "I see a lot of people who I think should eat more fish and reduce caloric intake, to eat more , to use canola or olive oil when they use oil, and to back off salty foods," he said.
Details and variations on the theme of the Mediterranean diet are outlined by the American Heart Association.
By Lauran Neergaard
AP Medical Writer
The Associated Press
Tuesday, June 15 2010
realized that I didn't need to use a sledgehammer. It was my choice," said
It's an unthinkable notion for a generation raised on the message that early saves lives, but specialists say more tumors actually are being found too early. That is raising uncomfortable questions about how aggressively to treat early growths in some cases, even how aggressively to test along with a push for more of the informed-choice programs such as the one Soviero used.
"The message has been, `Early detection, early detection, early detection.' That's true for some things but not all things," said Dr. Laura Esserman, a at UCSF. She helped lead a study, reported last week, that found mammography is increasing diagnoses of tumors deemed genetically very low risk.
"It's not just all about finding any cancer. It's about being more discriminating when you do find it," she added.
Today's can unearth tumors that scientists say never would have threatened the person's life. The problem is there aren't surefire ways to tell in advance which tumors won't be dangerous .just some clues that doctors use in prescribing treatment.
Work is under way to better predict that, and even the staunchest supporters of screening call overdiagnosis a problem that needs tackling.
"We're really at a tipping point right now, where we have a trade-off between the benefits of finding cancer early and the harms that are caused," said Dr. Len Lichtenfeld of the . "We treat more patients than we know will benefit. ... We just don't know who they are."
Nowhere is the disconnect more obvious than with prostate cancer screening. Most men over 50 have had a to check for it even though major medical groups don't recommend routine PSAs, worried they may do more harm than good for the average man.
the evidence? A study of 76,000
A European study of 162,000 men screened less aggressively a PSA every four years versus none found seven fewer deaths per 10,000 men screened. But 48 men had to be treated to prevent each death, meaning many men who weren't facing death experienced treatment that can have such side effects as .
Thus, the American Cancer Society urges that men weigh the limitations of PSAs against their individual risk and fear of cancer before deciding for themselves. Government guidelines say men over 75 shouldn't get a PSA at all although about one-third do.
is the controversy that refuses to die," said Dr. Michael Barry of
Mammograms aren't nearly as controversial, except for the when-to-start-them question. Most medical groups advise age 40; a government task force ignited complaints last year by advising not until 50. Generally, studies find they cut the risk of death from breast cancer by roughly 20 percent.
The trade-off: More than three-quarters of the 1 million-plus anxiety-provoking biopsies done each year to check out suspicious spots turn out to have been false alarms.
The bigger unknown is overdiagnosis, as closer mammogram readings spot ever-earlier growths.
A study in last month's Journal of the said nearly one-quarter of breast tumors found by mammograms may be overdiagnosed. That includes invasive cancer, but also a common milk-duct growth called DCIS, or ductal carcinoma in situ.
DCIS isn't invasive cancer and isn't life-threatening; it's described as "stage zero" cancer or even pre-cancer. But it is a risk factor for later developing invasive disease, and many of the 50,000 DCIS cases a year get the same care as women with outright early cancer.
Research is examining when and how to scale back aggressive DCIS care. At UCSF, Dr. Shelley Hwang is testing whether hormone drugs such as tamoxifen allow DCIS patients to avoid surgery altogether.
A colleague, Dr. Karla Kerlikowske, this spring reported tumor markers that suggest up to 44 percent of DCIS patients might skip aggressive treatment. A government panel last year even urged removing the word "carcinoma" from the name, to lessen fear.
DCIS, Esserman is designing a first-of-a-kind study
to start by summer's end at five
"If you've had a normal mammogram and develop a new mass, don't ignore that. If you have a new symptom, those are things you don't want to ignore," Esserman said. "The public also has to understand that it's complicated and there are some cancers that are very slow-growing."
problem with our tests is they can see too much," added study author Dr.
H. Gilbert Welch of
Another issue is overscreening testing people who won't benefit, or testing too often.
Just on Monday, a survey of 950 doctors published in Archives of Internal Medicine found fewer than one-third follow national guidelines that say 30-somethings at low risk of cervical cancer need a Pap smear every three years instead of every year. They even too frequently screen women who tested free of the virus that causes this slow-growing tumor.
Worse, a 2004 study estimated nearly 10 million women had still received a Pap, which only checks for signs of cervical cancer, after losing their cervix to a hysterectomy for noncancerous reasons.
Then there are the "incidentalomas," a word recently coined to describe another growing problem. Get a chest CT scan to check for, say, heart disease. In addition to your arteries, it might also show your lungs and any dot or shadow leads to even more testing to rule out cancer.
That happened to Lichtenfeld, the cancer society expert, during his own heart CT two years ago. A follow-up scan six months later showed the small nodule on his lung wasn't growing, but did flag as suspicious additional tiny inflamed spots. Lichtenfeld knew those spots weren't very risky and refused doctors' recommendations for pricey additional tests.
However those overarching questions turn out, patients today face tough treatment choices and that's where "shared decision-making" programs come in. They help patients balance the right amount of care for their comfort level. Some, like Soviero, want less while others want more.
underuse to one person might be overuse to another," said Jeff Belkora, who directs the decision-services program at
UCSF's program sends newly diagnosed a DVD to watch before that all-important first visit with a cancer specialist, to outline treatment options for their cancer stage and dispel myths. Patients also are offered a unique service, the aid of an intern to create a good list of questions to ask at that visit and then to attend with them, recording the doctor's answers so they won't forget.
Soviero, now 63, first used the program in 2000 and her right breast remains cancer-free, affirming her choice to avoid chemotherapy. Last year, a mammogram spotted a tiny, unrelated tumor in her other breast. She went through the program again, and her fears about another round of radiation were relieved. She chose the same care lumpectomy and radiation but no chemo.
"The hard part of making a decision is you never know. ... I was lucky. I made the right decision, but you only know that down the road, looking back," Soviero said.
UCSF Decision Services: http://www.decisionservices.ucsf.edu/
Foundation for Informed Medical Decision-Making: http://www.informedmedicaldecisions.org
Archives of Internal Medicine: http://archinte.ama-assn.org/
Journal of the National Cancer Institute: http://jnci.oxfordjournals.org/
Veterans Affairs Outcomes Group: http://www.vaoutcomes.org
American Cancer Society: http://www.cancer.org
Tuesday, June 15 2010
ScienceDaily (June 15, 2010) New research from NYU Langone Medical Center shows that a simple, inexpensive and noninvasive carotid artery ultrasound of the neck can be used as a preliminary diagnostic tool for coronary artery disease (CAD). This may be an alternative to the standard, expensive and more invasive coronary angiography. The ultrasound test can also be used to rule out the diagnosis of CAD in patients presenting with reduced heart pump function.
The new study appears in the June 2010 issue of the American Heart Journal.
"Our research has identified that carotid artery ultrasound is capable of identifying the presence of severe and extensive coronary artery disease," said Harmony R. Reynolds, MD, assistant professor of Medicine and associate director of the Cardiovascular Clinical Research Center at NYU Langone Medical Center. "Based on our findings, physicians might consider using the carotid ultrasound test as an initial screen for CAD in patients with reduced heart pump function and no history of heart attack. If a patient tests positive for plaque buildup in the neck arteries, then it can be followed by angiography of the heart arteries."
When a patient has reduced heart function, severe and extensive CAD is often the cause. CAD is a narrowing of the arteries in the heart caused by deposits of plaque. This condition reduces the flow of blood and oxygen to the heart and may lead to weakening of heart muscle and/or a heart attack.
Traditional diagnosis of CAD is through coronary angiography. However, this test is an invasive and expensive catheter imaging procedure that is associated with risks from contrast material and radiation exposure. In the study, patients underwent the noninvasive carotid artery ultrasound to determine the artery's intima-media thickness (IMT) and presence or absence of plaque. Researchers concluded that carotid artery ultrasound is a valuable screening tool for diagnosing and excluding CAD when a patient has heart muscle weakness without a known cause.
"Ultrasound of the carotid artery is a very widely
available and inexpensive technique, offered at
Harmony R. Reynolds, David A. Steckman, Paul A. Tunick, Itzhak Kronzon, Iryna Lobach, Barry P. Rosenzweig. Normal intima-media thickness on carotid ultrasound reliably excludes an ischemic cause of cardiomyopathy. American Heart Journal, 2010; 159 (6): 1059 DOI: 10.1016/j.ahj.2010.03.026
Tuesday, June 15 2010
WASHINGTON (Reuters) The World Health Organization, governments and nonprofit groups are saving lives by distributing drugs to developing countries, but they are not paying enough attention to the dangers of drug-resistant bugs, according to a report released on Tuesday.
Since 2006 donors have spent more than $1.5 billion on specialized drugs to treat resistant bacteria and viruses, and this could worsen, the report cautions.
Bacteria and viruses begin to evolve resistance to drugs almost as soon as they first encounter them. If leaves even one microbe alive, it will reproduce and whatever genetic attributes helped it survive will be multiplied in the next generation.
week, experts told a Congressional panel that
The Center's report looks for even broader action, urging WHO to lead others, including , governments, philanthropies that buy and distribute medicines, hospitals, healthcare providers, pharmacies and patients.
The report finds clear links between increased drug availability and resistance. For instance, in countries with the highest use of antibiotics, 75 to 90 percent of Streptococcus pneumoniae strains are drug-resistant, it found.
"The number of people being treated for HIV/AIDS, for example, increased 10-fold between 2002 and 2007; there was an 8-fold rise in deliveries of (drugs) for between 2005 and 2006, and the Stop TB Partnership's Global Drug Facility has expanded access to drugs for TB patients, offering nearly 14 million patient treatments in 93 countries since 2001," the report reads.
"While increased access to necessary drugs is clearly desirable, it brings challenges in preserving the efficacy of these drugs and ensuring they are used appropriately."
The Center for Global Development, an independent, nonprofit group, specializes in research on global poverty and inequality.
(Reporting by Maggie Fox; Editing by Paul Simao)
Monday, June 14, 2010
By Anne Harding
Monday, June 14, 2010
the percentage of women who choose to have their other, cancer-free breast
removed at the same time for preventive reasons is increasing, Dr. Elizabeth B.
Habermann of the
In 1990, the National Institutes of Health recommended breast-conserving surgery-"lumpectomy," in which only the tumor and are removed-along with radiation as the preferred treatment for breast cancer in one breast. Numerous studies done in the previous decade had found that women fared just as well with lumpectomy and radiation as they did with mastectomy, a more radical operation that carries greater risk of complications.
and her team decided to conduct their study after investigations by researchers
While nearly 41 percent of the women diagnosed in 2000 had mastectomies, 37 percent of those diagnosed in 2006 did, the researchers found.
But the percentage of women who had their other, non-cancerous breast removed as well increased to around 6 percent by 2006, from around 2 percent in 2000.
reason why mastectomy rates were increasing at the three centers while
continuing to decline overall isn't clear, Habermann
said. Patients who are referred to these centers might be seeking more than women
treated elsewhere in the
On the other hand, according to the researcher, "it's possible that these cancer centers are seeing trends ahead of what's going to happen nationwide."
There was a small increase in mastectomy rates between 2005 and 2006, Habermann noted. While this increase wasn't statistically significant, meaning it could have been due to chance, it could also signal a future rise in mastectomy rates.
She and her colleagues will continue to follow the trend in mastectomy rates, and are particularly interested in monitoring outcomes for the women who opt for having both breasts removed.
"There are some good things about it," Habermann noted. "It's very uncommon to have breast cancer after having both breasts removed." However, she added, "there are issues...because it's a larger operation and there may be more complications."
Monday, June 14, 2010
ScienceDaily (June 14, 2010) Results of new research reveal that the insulin-producing beta cells can proliferate in patients recently diagnosed with type 1 diabetes and suggest that, in the future, an intervention might be devised which could allow such patients to renew their own capacity to produce insulin.
Researchers from the
The research is published on-line at Diabetologia and is funded by Juvenile Diabetes Research Foundation.
The findings are important because, until now, it has
been generally believed that, in humans, beta cells divide only very
infrequently after the first year or so of life and that they do not readily
proliferate once type 1 diabetes is diagnosed. By studying the same unique
collection of pancreas specimens that last year led the research team to
conclude that some cases of type 1 diabetes may have a viral cause, this
current study presents evidence that there is a 10-fold increase in islet cell
replication in patients recently diagnosed with type 1 diabetes. A similar
response had been seen previously in an animal model of type 1 diabetes by a
member of the team, Professor Adrian Bone (
The factors that trigger the replication process in patients with type 1 diabetes are still unclear, although the study shows a correlation with the infiltration of immune cells (which suggests that an immune mediator is likely to be involved).
The results of the research offer the hope that, in future, it might be possible to encourage a newly diagnosed type 1 diabetes patient's own beta cells to reproduce as a means of replacing those being destroyed by the disease. The development of such a therapy could mean that some patients with type 1 diabetes would be able to produce their own insulin for a longer period, thereby reducing the need for pharmaceutical interventions.
Professor Noel Morgan, Director of the Institute of Biomedical and Clinical Sciences at the Peninsula Medical School, commented: "Our findings are significant because they challenge current thinking and offer the hope that, at some point in the future, a therapy could be developed that would allow individuals who are developing type 1 diabetes to retain their own insulin. We are a long way from this point, but the first steps have been taken with this research."
He added: "We could not have come to our current conclusions without access to the unique collection of pancreas specimens from patients who died soon after being diagnosed with type 1 diabetes, which was collected by our colleague Dr. Alan Foulis from the Department of Pathology at Glasgow Royal Infirmary. The specimens are allowing us to investigate the cellular processes that occur in the beta cells of people with type 1 diabetes in a way that has not been possible before."
Karen Addington, CEO at JDRF said: "Interventions to halt and reverse the onset of type 1 diabetes are a fundamental part of JDRF's objective to cure, treat and prevent type 1 diabetes and its complications, and these results inform our global research programme. These are early stage findings, but we are positive about the impact this could have for people diagnosed with type 1 diabetes in the future."
A. Willcox, S. J. Richardson, A. J. Bone, A. K. Foulis, N. G. Morgan. Evidence of increased islet cell proliferation in patients with recent-onset type 1 diabetes. Diabetologia, 2010; DOI: 10.1007/s00125-010-1817-6
By Maria Cheng
AP Medical Writer
The Associated Press
Monday, June 14, 2010
In an analysis of five following about 60,000 patients, experts found a link between people taking medicines known as angiotensin-receptor blockers, or ARBs, and cancer. The drugs are taken by millions of people worldwide for conditions like high blood pressure, heart problems and diabetic kidney disease.
In the analysis, researchers found that people who took the drugs had about a 1 percent higher risk of getting cancer than people who weren't on the drugs. This included a whole prostate, breast and a noticable spike in lung cancer.
About 85 percent of those people were on telmisartan, sold as Micardis, made by Boehringer Ingelheim Corp. There was no difference in the rate of cancer deaths in people on the drugs compared to those not on them.
The study was published Monday in the medical journal, . No funding was provided for the study, but Dr. Ilke Sipahi, the study's lead author, has received past payments from drug makers Pfizer Inc., AstraZeneca PLC and Ranbaxy Pharmaceuticals Inc., which all make blood pressure drugs. Other authors reported similar grants from other pharmaceuticals.
risk for the is modest,"
said Sipahi, associate director of heart failure and
Sipahi and colleagues calculated that one extra cancer case will occur for every 105 people taking the medications for about four years. He said there wasn't enough information to know if this disappears once people stop taking the medications.
The maker of the most-used drug in the study, Boehringer Ingelheim, disputed the findings and said Micardis is one of the best-researched drugs worldwide. The company claimed in a statement that it had "internal safety data" contradicting the Lancet study. According to studies run by the pharmaceutical, there was no link between increased and Micardis.
Sipahi warned patients not to stop taking their drugs, and recommended they consult their doctor if they were concerned.
Since completing the analysis, Sipahi said he now thinks twice about whether to prescribe the drugs. But he said many heart patients couldn't take other drugs because of their side effects and they should continue taking ARBs since their chances of dying from heart failure outweighed their chances of getting cancer.
In an accompanying commentary in the Lancet Oncology, Steven Nissen, a cardiologist at the Cleveland Clinic, described the study as "disturbing and provocative." He called for regulatory agencies to order drug makers to submit more data on their products and to promptly report their findings.
Michael Thun, vice-president emeritus of epidemiology and surveillance at the , said the study underlined how hard it is to pick up potentially dangerous side effects in drugs once they are on the market. He was not connected to the study.
Because cancer can take decades to develop, Thun said it's impossible to know if a new drug can in the future before it goes on sale. "There's a tension between making drugs available in a timely way and detecting some cancer effect in the long term that you didn't expect," he said.
Thun also added it would be important to determine if it was a single drug linked to cancer, like Micardis, or if the entire class of drugs was implicated.
Monday, June 14, 2010
ScienceDaily (June 14, 2010) The use of medications that increase sensitivity to the sun, combined with exposure to sunlight, appears to be associated with the risk of age-related cataract, according to a report posted online that will appear in the August print issue of Archives of Ophthalmology, one of the JAMA/Archives journals.
Besides age, several risk factors have been identified for common types of cataract, including smoking, diabetes and hypertension, according to background information in the article. Sunlight and exposure to ultraviolet-B (UV-B) rays have been shown to be associated with cortical cataract, clouding or opacity occurring first on the outer edges of the lenses. Some medications taken by mouth or by injection have been shown to increase sensitivity to the sun, causing signs and symptoms such as itching or rash on areas of the skin exposed to sunlight.
To determine if these medications also affect the
association of sun exposure to cortical cataract, Barbara E. K. Klein, M.D.,
M.P.H., and colleagues at the
An increasing percentage of study participants reported having taken these types of medications over a 15-year follow-up period (24.1 percent at the beginning of the study, compared with 44.8 percent at the 15-year follow-up). The overall incidence of cataract was not associated with their use or with exposure to sunlight. However, after adjusting for age and sex, an interaction between sun-sensitizing medication use and UV-B exposure was associated with the development of cortical cataract.
"The medications (active ingredients) represent a broad range of chemical compounds, and the specific mechanism for the interaction is unclear," the authors write. The lens of the eye develops from the same layer of tissue as the skin, and medication that increases the skin's response to the sun may modify the effect of sunlight exposure on the eye as well.
"Our results need to be evaluated in other populations, especially in view of the increasing frequency of sun-sensitizing medications," the authors conclude. "If our findings are confirmed, it would be important to examine whether the effect is greater in those with higher levels of ambient sunlight (UV-B) exposure and if dose or duration of medication use is also important. Because cortical cataract is a common lens opacity in adults, present in about 16 percent of the Beaver Dam Eye Study population at the baseline examination, our study findings may be relevant to public health."
Barbara E. K. Klein; Kristine E. Lee; Lorraine G. Danforth; Tracie M. Schaich; Karen J. Cruickshanks; Ronald Klein. Selected Sun-Sensitizing Medications and Incident Cataract. Arch Ophthalmol, 2010; 0 (2010): 2010. 138 [link ]
By Anne Harding
Monday, June 14, 2010
Dr. Richard Karas of the Molecular Cardiology Research Institute at and his colleagues had previously found that people with low levels of low-density lipoprotein (LDL, a.k.a. "bad" cholesterol) were actually at higher risk of cancer.
In the current study, the researchers used the same body of research-dozens of "" clinical trials of cholesterol-lowering drugs called statins-to investigate whether there might be a relationship between their high-density lipoprotein (HDL) levels and cancer risk. (Karas and one of his co-authors have received consulting fees or grants from two statin manufacturers.)
Their analysis, of 24 studies in all, included about 76,000 people assigned to take statins and nearly 70,000 people who were given placebo. They followed subjects for an average of about five years.
The risk of developing any type of cancer during follow-up decreased as a person's baseline HDL cholesterol levels rose, Karas and his colleagues found. Doctors recommend that be above 40 milligrams per deciliter (mg/dL) for men and above 50 mg/dL for women.
For example, for people with HDL levels of 30 mg/dL, there would be about 15 cases per 10,000 people per year; with HDL levels of 50 mg/dL, there would be just 10 cancers for every 10,000 people. Each 10 mg/dL increase in HDL levels reduced cancer risk by 36 percent.
"Really, the higher the better," Karas said. People can increase their HDL levels by exercising, eating well, maintaining a healthy weight, drinking moderately, and not smoking, he added. Taking statins will modestly increase HDL levels.
"Our most effective HDL-raising drug that's currently available is niacin," he added, noting that just 10 percent of people who could benefit from the drug are taking it.
Niacin is a B-vitamin, but given in mega-doses; the findings should in no way be seen as recommending that people start taking the drug to cut cancer risk, Karas warned. But, he added, the findings do suggest the idea is worth investigating.
It's unclear why HDL cholesterol would reduce cancer risk, but it may be due to its antioxidant effects, according to Karas. HDL cholesterol may also help the in its task of searching for and destroying abnormal and potentially cancerous cells, he added.
HDL directly affects cancer risk or not is unclear. Low HDL cholesterol could
also simply be a marker for that increase
disease risk, such as inflammation, Dr. Jennifer G. Robinson of the
The things that people can do to up HDL cholesterol levels-exercising, quitting smoking, eating right, keeping their weight under control-are good for us no matter what, Robinson wrote.
Monday, June 14, 2010
ScienceDaily (June 14, 2010) White blood cells with receptors for both virus and nerve proteins may assault nerves after fighting an infection
A virus infection can incite the body to attack its own nerve tissue by activating unusual, disease-fighting cells with receptors for both viral and nerve proteins. The dual-receptor observation suggests a way brain and spinal cord nerve damage might be triggered in susceptible young adults afflicted with multiple sclerosis (MS).
This is thought to be the first study to reveal a mechanism for autoimmune disease that depends on destroyer immune cells expressing dual receptors for a normal protein made by the body and a pathogen.
Multiple sclerosis is one of many autoimmune disorders in which the body's lines of defense become misguided and start damaging normal tissue. In the case of multiple sclerosis, the protective sheath around major nerves -- the myelin -- in the brain and spinal cord disintegrates. Like a frayed electrical cord, the nerves no longer transmit a clear signal.
People with multiple sclerosis might lose their ability to see, walk, or use their arms, depending on which nerves are affected. The symptoms can appear, disappear, and re-appear. The disease is more common in women than in men.
In healthy people, the immune system is kept in check to tolerate the usual proteins and cells in the body, much like an eager watch dog is put on a leash and trained to ignore friends and neighbors, yet still protect the family.
"Autoimmunity is believed to arise from an accidental breakdown in this tolerance of the body's own proteins. This breakdown is triggered by something in the environment, most likely a pathogen," noted Goverman, professor and acting chair of immunology whose research concentrates on the origins of autoimmune disease. Her lab is studying mechanisms that maintain tolerance, as well as the "tripping" mechanisms that defeat it.
In their most recently published study, her research team genetically engineered mice that over-produce a certain type of white blood cell from a group known as killer T cells. The normal function of killer cells is to attack tumor cells or cells infected with viruses or other pathogens. These T cells have receptors that recognize specific proteins that infected cells display to them, much like holding up a target in a window.
The specific killer T cells examined in this study were CD8+ T cells. The Goverman lab engineered mice to over-produce CD8+cells that recognized myelin basic protein, a predominant protein in the myelin sheath that covers nerves. The major question investigated in the study was whether the genetically engineered mice would exhibit a disease that resembled multiple sclerosis.
The researchers infected the mice with a virus that has itself been engineered to produce myelin basic protein. This infection should activate the CD8+T cells to first attack the virally infected cells making myelin basic protein to eliminate the virus, then kill other cells that make myelin basic protein to wrap around nerves. Killing those cells would destroy the myelin sheath.
As expected, the mice developed a multiple sclerosis-like disease. But the researchers were surprised when viruses lacking the myelin basic protein also triggered the disease.
Additional cross-breeding experiments revealed the existence of two receptors on a few of the CD8+T cells. These cells, engineered specifically to bind to myelin basic protein, also built their own receptors for viruses, and could recognize both. When exposed to cells infected with viruses, they would bind to and destroy them using one receptor. Geared up as if they were beserk, some of these double-agent cells then would head elsewhere to bind their other receptor to cells producing myelin basic protein and ruin the coats on nerve cells.
"These results," the authors noted, "demonstrate a role for dual-receptor cells in autoimmunity." The study also points to why a ubiquitous viral infection could leave most people without any lasting effects, but trigger autoimmunity in genetically predisposed individuals.
The findings open a new perspective on the proposal that multiple sclerosis is virally induced, despite the inability to detect infectious virus in the central nervous system of multiple sclerosis patients. Data from other studies show that CD8+T cells can cross the blood-brain barrier, and also that multiple sclerosis patients have more central nervous system protein-specific CD8+T cells, compared to healthy people.
In the dual-receptor model, the autoimmune activity against nerve protein can continue after the virus is wiped out. Multiple sclerosis patients usually have high levels of antibodies indicating past infectious from several common viruses, but a live virus associated with multiple sclerosis has not been consistently observed. Therefore, to date, no specific virus has been confirmed as a causative agent for multiple sclerosis.
The authors explained that it's possible that multiple viruses could influence susceptibility to multiple sclerosis. The ability of any particular virus to contribute to the disease could depend on an individual's own repertoire of other predisposing genes, exposure to other predisposing environmental factors, and the random chance that T cells had been generated that recognize a myelin protein and a pathogen.
Receptors on T cells are randomly generated during their development. This observation helps explain why multiple sclerosis is partly a matter of chance. Some people with a genetic predisposition and environmental exposure develop the disease, while others with similar genetic predisposition and environmental exposure do not.
It's uncertain how common these dual-receptor T cells are, according to the researchers, although there are reports that up to one-third of human T cells express dual receptors. Goverman and her group plan to test samples from multiple sclerosis patients and see how many have dual-receptor T-cells.
A grant from the National Institutes of Health supported the study.
Qingyong Ji, Antoine Perchellet, Joan M Goverman. Viral infection triggers central nervous system autoimmunity via activation of CD8 T cells expressing dual TCRs. Nature Immunology, 2010; DOI: 10.1038/ni.1888
By Julie Steenhuysen
Monday, June 14, 2010
The study turned up a known offender - the APOE4 gene - as the most strongly linked with the disease, but it also confirmed three other genes - CLU, CRI, PICALM - that have been more recently linked with Alzheimer's.
And they fingered two others - BIN1 and CNTN5 - which have been suspected, but not strongly linked with Alzheimer's.
While the findings are preliminary, "they may help prioritize targets for future genetic studies," Drs. Alessandro Biffi and Christopher Anderson of Massachusetts General and the Broad Institute wrote in the Archives of Neurology.
Researchers suspect genes can explain 60 to 80 percent of the risk of late onset Alzheimer's disease, the kind that occurs with age.
He said it now appears unlikely that there are many more single genes like APOE4 that contribute significantly to Alzheimer's disease, but there are likely many genes that, when combined, raise a person's risk.
"The way most of us will get through these big sets of risk genes. They are beginning to discover a few of them. None of them is sufficient to get Alzheimer's on its own," Thompson said in a telephone interview.
"It's the slow erosion of the brain from an army of culprits."
Monday, June 14, 2010
ScienceDaily (June 14, 2010) Nearly half of patients hospitalized with bipolar disorder may suffer from hypertension, and the younger a person is diagnosed with the psychiatric condition the more likely they are to develop high blood pressure, according to a recent Michigan State University study.
The study, led by MSU psychiatrist Dale D'Mello, analyzed 99 patients hospitalized for bipolar disorder, a condition sometimes called manic-depressive disorder and characterized by mood swings ranging from depression to mental hyperactivity known as mania.
D'Mello presented his findings -- which could
lead to improved treatments -- recently at the American Psychiatric
Association's 2010 annual meeting in
While the connection between such disorders and cardio-metabolic conditions such as heart disease and diabetes has been established, D'Mello also discovered bipolar patients with high blood pressure suffered higher levels of mania.
"There is a large clinical relevance to the finding hypertension could be linked to the severity of bipolar disorders," he said. "There is some similarity to the pathology of the two conditions; they both can be triggered by stress and are tied to the excretion of norepinephrine, a hormone affecting how the brain reacts to stress."
Understanding how bipolar disorder and cardio-metabolic conditions are linked could help physicians create more effective treatment options, he added.
"These findings show that we should look to treat hypertension more aggressively in bipolar patients," said D'Mello, who has been studying the link between psychiatric and medical conditions for decades. "There also is some evidence hypertension may lead to brain lesions; diagnosing high blood pressure and treating it earlier may change the medical outcomes for people battling bipolar disorders."
In addition, similar to how certain drugs such as lithium do not work as well in bipolar patients who are obese, different medications may be identified that work better.
D'Mello, a professor in MSU's Department of Psychiatry, part of the colleges of Human Medicine and Osteopathic Medicine, said the next step is to discover how hypertension and other cardio-metabolic disorders interact over the long term.
"Is this just a point of time comparison or an enduring concern? We need to follow people and look at mania ratings over a period of time and not just during a hospital stay," he said.
By Megan Brooks
Monday, June 14, 2010
NEW YORK (Reuters Health) Among rice lovers, people who eat brown rice or other whole grains seem to have a lower risk of developing diabetes than those who eat , Boston-based researchers said on Monday.
Among more than 197,000 US adults followed for up to 22 years, they found that eating more refined white rice was associated with a higher risk of type 2 diabetes, while eating more brown rice was associated with a lower .
general, the public should pay special attention to their and try to
replace refined carbohydrates, including white rice, with whole grains,"
Dr. Qi Sun, of Harvard School of Public Health and
Brigham and Women's Hospital, told Reuters Health by email. Current
More Americans are eating rice, Sun and colleagues note in their report. According to the U.S. Department of Agriculture, rice consumption has shot up more than threefold since the 1930s. However, most of the rice eaten by Americans is refined white rice, which is stripped of its fiber, vitamins and minerals in the refining process and is more likely to fuel an increase in blood sugar after eating than its healthier whole grain cousin, brown rice.
Across all three studies, having more white rice in the diet was associated with an elevated risk of type 2 diabetes, the researchers report in the Archives of Internal Medicine.
When they pooled the data and took into account and lifestyle factors that might influence the results, the doctors and nurses who ate the most white rice (at least 5 servings per week) had a significant 17 percent higher risk of than those who ate the least white rice (less than 1 serving a month).
In contrast, eating 2 or more servings of brown rice each week, as opposed to less than 1 serving a month, was associated with an 11 percent reduced risk of developing type 2 diabetes. Again, this was after accounting for other diet and lifestyle factors that might influence the results. The seen for higher brown rice consumption was "not dramatic, albeit significant," Sun said.
The researchers estimate that replacing one third of a serving of white rice daily (about 50 grams) with the same amount of brown rice could lower a of getting type 2 diabetes by 16 percent. They further estimate that replacing white rice with whole grains as a group could be associated with a risk reduction as great as 36 percent.
It's important to note that white rice contributed less than 2 percent of total calories for study subjects; brown rice less than 1 percent. Given that rice was not a significant part of the diet, there could be other reasons for the findings, the researchers acknowledge. But Sun pointed out that they adjusted for numerous factors that might influence the results and the findings still held up.
It's also possible that eating more brown rice is a marker for a healthier lifestyle. And, in fact, the brown rice eaters in the study did have a more health-conscious lifestyle and diet.
However, Sun said, "we adjusted for these factors including body adiposity (fat), smoking, physical activity, and other dietary factors, and the significant associations remained. This suggests that what we observed is unlikely the result of other factors."
The consistency of the results across all 3 studies also suggests that the findings are unlikely to be due to chance, Sun and colleagues note in their report.
2 diabetes, which is closely linked to being overweight as well as poor diet
and lack of exercise, is reaching epidemic levels. An estimated 8 percent of
"From a public health point of view, replacing refined grains such as white rice by whole grains, including brown rice, should be recommended to facilitate the prevention of type 2 diabetes," Sun and colleagues conclude.
Source: Archives of Internal Medicine, June 14, 2010.
By Kate Kelland
Monday, June 14, 2010
Researchers found that among men exposed to pesticides such as DDT, carriers of the gene variants were three and a half times more likely to develop Parkinson's than those with the normal version of the gene.
The scientists, whose work was published in the Archives of Neurology journal, think the brains of people with the fail to flush out toxins as efficiently as those with normal versions of the gene, suggesting environmental as well as genetic factors are important in the risk of Parkinson's.
DDT, which belongs to a group of pesticides known as organochlorines, is one of the "Dirty Dozen" chemicals banned by a 2001 United Nations convention after it was found to be a toxin that can suppress the immune system.
It is infamous for threatening bird populations by thinning eggshells, and has also been linked to increase risks in humans of diseases such as cancer and Parkinson's -- an incurable and often deadly .
But exemptions to the DDT ban are allowed in many developing nations because it so effective in killing mosquitoes. DDT's Swiss inventor Paul Hermann Muller won the 1948 Nobel Prize for Medicine -- before its wider were known.
Elbaz and Fabien Dutheil,
The scientists found the link was around 3.5 times stronger in men who carried two copies of a gene known as ABCB1, which plays a role in helping the brain flush out dangerous chemicals.
"It seems therefore that people who have these variations would have higher levels of insecticides in the brain because the brain's pump is not clearing them out properly."
Elbaz said his work supported a growing body of evidence that genetic factors alone were not to blame for Parkinson's, but that when they combined with factors in the environment, the risk could significantly increase.
(Editing by Jon Boyle)
By Rachael Myers Lowe
Monday, June 14, 2010
Cataracts, in which a clear lens becomes cloudy, are the leading cause of impaired vision. More than half of all aged 75 or older Americans have a cataract or have had . The first symptoms may be difficulty seeing at night followed by increasingly blurred and dimmed vision.
Earlier research by Dr. Barbara Klein and colleagues had shown that certain "sun-sensitizing" medications might be linked to cataracts in men. To see if this was true in all people, the University of Wisconsin School of Medicine and her colleagues analyzed the medical records of 2119 patients followed over 15 years.
They found that for varying levels of sunlight exposure, people who used a number of drugs including the painkiller naproxen, the diabetes drug glyburide, the antibiotic ciprofloxacin, the antidepressant amitriptyline, and the blood pressure medication hydrochlorothiazide had about a 26 percent chance of developing a condition known as a cortical cataract.
Still, Klein was reluctant to make too much of the results. "I don't want to scare the pants off people," she told Reuters Health when asked if the data warranted warning about cataract risks with the use of these drugs and sun exposure.
Much more research has to be done to meticulously measure drug dosage and duration and sun exposures before definitive conclusions can be drawn, she cautioned.
the other study, Julie Mares, of the
Delaying cataracts in an increasingly aging population could reduce a on the healthcare system, Mares and colleagues write in the June issue of the Archives of Ophthalmology after finding a healthy diet may delay cataracts at least 2 and a half years.
While the biggest risk for getting cataracts is getting older, smoking is the most common "modifiable" risk factor reported in population studies. Sun exposure and poor diets have also been associated with increased risk but on diets has usually focus on a limited number of vitamins or minerals at a time.
The researchers analyzed data from 1808 women enrolled in the Women's Health Initiative Observational Study for an association between eating a healthy diet and the development of cataracts.
Cataracts were common in the women and occurred more often as they got older. Overall, 41 percent of the women (736) had evidence of cataract severe enough to warrant surgery in at least one eye or reported having had cataract surgery.
After taking age, smoking, and other factors into account, researchers found the women who ate the diets highest in and lowest in fats had a 37 percent lower risk of cataracts than women in the study who ate less healthy diets.
By another measure, "if you take two women of the same age, the woman with the lowest healthy diet score would be about 1 and a half times more likely to have a cataract at any given age," Mares said.
The study doesn't directly prove cause and effect, "but so many arrows point in this direction that sometimes we don't need clinical trials to hit us over the head to suggest that small changes we do on a day-to-day basis can have a large impact on our health in the future," Mares said.
The "more than half" of Americans who have cataracts or have had surgery for them "might be cut to roughly 40% -- or 40 rather than 50 of every 100 Americans -- if those of us with poorer than average diets ate healthy diets; and cut further still if we did not smoke," Mares said.
Despite the limitations of her study of drugs and sun exposure, the other study's finding that diet might prevent some cataracts is "exciting," Klein said.
"Anything you can do to delay putting a knife in someone's eye is a good thing," Klein said.
Archives of Ophthalmology, June and August 2010.
By Mike Stobbe
AP Medical Writer
The Associated Press
Monday, June 14, 2010
together, more than 2 million of 12 million
study is being called the first to estimate how often current and former
patients have skipped getting care because of money worries. It was led by
Kathryn Weaver, a researcher at
Survey participants were asked if they had needed medical care in the previous year but didn't get it because they couldn't afford it. Cancer survivors younger than 65 were between 1.5 and 2 times more likely to have said yes to that question than those who hadn't had cancer.
makes sense cancer survivors can be expected to have more health problems,
said David Howard, an
"If anything, I was surprised it was so low," said Howard, who was not involved in the new study.
About 10 percent of cancer survivors also said they had to forgo filling prescriptions. Another 11 percent said they put off dental care and 3 percent postponed mental health services because of costs.
The new study suggests that far more than the uninsured are struggling with medical bills. Those with insurance may still have trouble paying for copays, deductibles and care not covered by their plan, experts said.