A European survey has issued preliminary results which show flu virus resistance to oseltamivir (Tamiflu). Some samples of the A (H1N1) virus, a human flu virus which is spreading in Europe this winter, is resistant to Tamiflu, a well-known antiviral drug.
The EU-funded VIRGIL network has tested 437 samples of the A (H1N1) flu virus strain between November 2007 and January 2008 in 18 European countries - of which 59 from nine different countries have become resistant to oseltamivir, 26 of them from Norway out of 37 that were sent for testing (in Norway).
Norwegian authorities, as soon as this high level of resistance to oseltamivir in the A H1N1 viruses became evident, notified other EU nations as well as the WHO (World Health Organization). An advisory to doctors and the general public has been issued by Norwegian authorities (advisory in Norwegian).
The significance of this latest data from the VIRGIL network is being assessed by experts from ECDC (European Center for Disease Prevention and Control), the European Commission, and WHO. Authorities say an interim joint-assessment will be issued soon, based on the preliminary results.
It is not possible at this stage to be precise as to how widespread and at what level influenza virus resistance to Tamiflu is in Europe. Experts suggest that resistant is significant throughout the continent, but perhaps not as high as it is in Norway.
Patients who become infected with the A (H1N1) flu virus strain do not seem to become sicker than those infected with "normal" seasonal influenza, the ECDC reports. Nevertheless, one should bear in mind that influenza A can be a serious and life-threatening illness for the elderly, the very young, and for those with debilitating illnesses.
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Saturday, February 2, 2008
Patients with Metabolic Disorder show comparable or better results in Treatment of Hypertension with Diuretics
Diuretics appear to show similar or better results for treating hypertension in patients with metabolic syndromes, when compared with calcium-channel blockers, alpha-blockers, or angiotensin-converting enzyme (ACE) inhibitors. In a report in the January 28 issue of Archives of Internal Medicine, a JAMA/Archives journal, the latter appeared to offer no advantage in improving the clinical outcome. When compared across racial groups, this seemed to be especially true for black patients.
Metabolic syndrome (a set of medical disorders that contribute to cardiovascular disease and diabetes), coupled with hypertension (high blood pressure) can put patients at an especially high risk of complications from cardiovascular disease. In this study, metabolic syndrome was defined by hypertension combined with at least two of the following factors: diabetes or pre-diabetes; a body mass index (BMI) of at least 30; high triglyceride levels; or low levels of high-density lipoprotein ("good" cholesterol).
Some medications for high blood pressure, including alpha-blockers, ACE inhibitors, and calcium-channel blockers, have been advocated over other drugs, such as beta-blockers and diuretics, for their favorable short term effects on metabolic parameters such as blood glucose or blood cholesterol levels.
Jackson T. Wright Jr., M.D., Ph.D., of Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, and colleagues evaluated data collected in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT). This study engaged a total 42,418 participants with hypertension and at least one other risk factor for cardiovascular disease. In this trial, patients were randomly assigned to take one drug as follows: diuretic (chlorthalidone, 15,255 patients), a calcium channel blocker (amlodipine besylate, 9,048 patients), an alpha-blocker (doxazosin mesylate, 9,061 patients) or an ACE inhibitor (lisinopril, 9,054 patients). This drug was used to start treatment, and if necessary for blood pressure control, other drugs could be added. Followup of participants continued for an average of 4.9 years for all drugs, with the exception of the alpha-blocker. The latter was discontinued after an average of 3.2 years due to increased rate of cardiovascular disease including an almost two-fold increased rate of heart failure in comparison to the diuretic population. Of the ALLHAT population, 23,077 ALLHAT participants (54.4 percent) met criteria for metabolic syndrome.
In their analysis, the authors report that, "No differences were noted among the four treatment groups, regardless of race or metabolic syndrome status for the primary end point (non-fatal myocardial infarction [heart attack] and fatal coronary heart disease)." In patients displaying metabolic syndrome (7,327 black and 15,750 white patients), the calcium channel blocker, ACE inhibitor and alpha-blocker showed higher rates of heart failure compared with the diuretic; the ACE inhibitor and the alpha-blocker additionally carried an increased risk for combined cardiovascular disease.
"The lack of benefit of the agents with the most favorable metabolic profile (i.e., ACE inhibitors and alpha-blockers) was especially marked in the black participants with metabolic syndrome," the authors continue. "The magnitude of the excess risk of end-stage renal [kidney] disease (70 percent), heart failure (49 percent) and stroke (37 percent) and the increased risk of combined cardiovascular disease and combined coronary heart disease strongly argue against the preference of ACE inhibitors over diuretics as the initial therapy in black patients with metabolic syndrome. Similar higher risk was noted for those randomized to the alpha-blocker vs. the diuretic."
The authors conclude, "These findings fail to provide support for the selection of alpha-blockers, ACE inhibitors, or calcium channel blockers over thiazide-type diuretics to prevent cardiovascular or renal outcomes in patients with metabolic syndrome, despite their more favorable metabolic profiles."
See Full Article
Metabolic syndrome (a set of medical disorders that contribute to cardiovascular disease and diabetes), coupled with hypertension (high blood pressure) can put patients at an especially high risk of complications from cardiovascular disease. In this study, metabolic syndrome was defined by hypertension combined with at least two of the following factors: diabetes or pre-diabetes; a body mass index (BMI) of at least 30; high triglyceride levels; or low levels of high-density lipoprotein ("good" cholesterol).
Some medications for high blood pressure, including alpha-blockers, ACE inhibitors, and calcium-channel blockers, have been advocated over other drugs, such as beta-blockers and diuretics, for their favorable short term effects on metabolic parameters such as blood glucose or blood cholesterol levels.
Jackson T. Wright Jr., M.D., Ph.D., of Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, and colleagues evaluated data collected in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT). This study engaged a total 42,418 participants with hypertension and at least one other risk factor for cardiovascular disease. In this trial, patients were randomly assigned to take one drug as follows: diuretic (chlorthalidone, 15,255 patients), a calcium channel blocker (amlodipine besylate, 9,048 patients), an alpha-blocker (doxazosin mesylate, 9,061 patients) or an ACE inhibitor (lisinopril, 9,054 patients). This drug was used to start treatment, and if necessary for blood pressure control, other drugs could be added. Followup of participants continued for an average of 4.9 years for all drugs, with the exception of the alpha-blocker. The latter was discontinued after an average of 3.2 years due to increased rate of cardiovascular disease including an almost two-fold increased rate of heart failure in comparison to the diuretic population. Of the ALLHAT population, 23,077 ALLHAT participants (54.4 percent) met criteria for metabolic syndrome.
In their analysis, the authors report that, "No differences were noted among the four treatment groups, regardless of race or metabolic syndrome status for the primary end point (non-fatal myocardial infarction [heart attack] and fatal coronary heart disease)." In patients displaying metabolic syndrome (7,327 black and 15,750 white patients), the calcium channel blocker, ACE inhibitor and alpha-blocker showed higher rates of heart failure compared with the diuretic; the ACE inhibitor and the alpha-blocker additionally carried an increased risk for combined cardiovascular disease.
"The lack of benefit of the agents with the most favorable metabolic profile (i.e., ACE inhibitors and alpha-blockers) was especially marked in the black participants with metabolic syndrome," the authors continue. "The magnitude of the excess risk of end-stage renal [kidney] disease (70 percent), heart failure (49 percent) and stroke (37 percent) and the increased risk of combined cardiovascular disease and combined coronary heart disease strongly argue against the preference of ACE inhibitors over diuretics as the initial therapy in black patients with metabolic syndrome. Similar higher risk was noted for those randomized to the alpha-blocker vs. the diuretic."
The authors conclude, "These findings fail to provide support for the selection of alpha-blockers, ACE inhibitors, or calcium channel blockers over thiazide-type diuretics to prevent cardiovascular or renal outcomes in patients with metabolic syndrome, despite their more favorable metabolic profiles."
See Full Article
Connection found between Inactive Lifestyles and Accelerated Aging
Those who are physically active in their leisure time seem to be younger than those with inactive lifestyles, from a biological perspective.
Generally, people who participate in regular exercise already have lower rates of cardiovascular disease, type 2 diabetes, cancer, high blood pressure, obesity, and osteoporosis. However, according to a report in the January 28 issue of Archives of Internal Medicine, one of the JAMA/Archives journals, there might be more to this than just avoiding these diseases. "A sedentary lifestyle increases the propensity to aging-related disease and premature death," the authors write. "Inactivity may diminish life expectancy not only by predisposing to aging-related diseases but also because it may influence the aging process itself."
A group of 2,401 white twins was studied by Lynn F. Cherkas, Ph.D., of King's College London, and colleagues. The team administered questionnaires related to physical activity level, smoking habits, and social and economic factors. Notably, the participants also provided a blood sample, and DNA was extracted from the white blood cells (leukocytes.)
The leukocyte DNA samples were analyzed for the length of their repeating sequences at each end of the chromosomes. These sequences, called telomeres, may serve as a marker of biological age, as they progressively shorten over time.
As expected, telomere length decreased with age, contributing to an average loss of 21 nucleotides (the basic structural units of DNA) per year. Less physically active men and women displayed shorter leukocyte telomeres than those who were more active in their leisure time. Even after normalizing for various factors, this trend remained. "Such a relationship between leukocyte telomere length and physical activity level remained significant after adjustment for body mass index, smoking, socioeconomic status and physical activity at work," observe the authors. "The mean difference in leukocyte telomere length between the most active [who performed an average of 199 minutes of physical activity per week] and least active [16 minutes of physical activity per week] subjects was 200 nucleotides, which means that the most active subjects had telomeres the same length as sedentary individuals up to 10 years younger, on average." When pairs of twins with different levels of physical activities were subsequently analyzed, similar results were shown.
The authors suggest a few mechanisms by which more sedentary lifestyles might contribute to telomere degeneration. One could be damage to cells caused by exposure to oxygen, called oxidative stress. Increased inflammation in sedentary persons may also create this effect Additionally, telomere length has been linked to perceived stress levels. This psychological stress may be reduced by physical activity, thus lessening its severity on telomeres and the aging process.
The authors conclude, relating this to daily life. "The U.S. guidelines recommend that 30 minutes of moderate-intensity physical activity at least five days a week can have significant health benefits," state the authors. "Our results underscore the vital importance of these guidelines. They show that adults who partake in regular physical activity are biologically younger than sedentary individuals. This conclusion provides a powerful message that could be used by clinicians to promote the potential anti-aging effect of regular exercise."
This study was supported in part by a grant from the Welcome Trust, grants from the National Institutes of Health and a grant from The Healthcare Foundation of New Jersey.
See Full Article
Generally, people who participate in regular exercise already have lower rates of cardiovascular disease, type 2 diabetes, cancer, high blood pressure, obesity, and osteoporosis. However, according to a report in the January 28 issue of Archives of Internal Medicine, one of the JAMA/Archives journals, there might be more to this than just avoiding these diseases. "A sedentary lifestyle increases the propensity to aging-related disease and premature death," the authors write. "Inactivity may diminish life expectancy not only by predisposing to aging-related diseases but also because it may influence the aging process itself."
A group of 2,401 white twins was studied by Lynn F. Cherkas, Ph.D., of King's College London, and colleagues. The team administered questionnaires related to physical activity level, smoking habits, and social and economic factors. Notably, the participants also provided a blood sample, and DNA was extracted from the white blood cells (leukocytes.)
The leukocyte DNA samples were analyzed for the length of their repeating sequences at each end of the chromosomes. These sequences, called telomeres, may serve as a marker of biological age, as they progressively shorten over time.
As expected, telomere length decreased with age, contributing to an average loss of 21 nucleotides (the basic structural units of DNA) per year. Less physically active men and women displayed shorter leukocyte telomeres than those who were more active in their leisure time. Even after normalizing for various factors, this trend remained. "Such a relationship between leukocyte telomere length and physical activity level remained significant after adjustment for body mass index, smoking, socioeconomic status and physical activity at work," observe the authors. "The mean difference in leukocyte telomere length between the most active [who performed an average of 199 minutes of physical activity per week] and least active [16 minutes of physical activity per week] subjects was 200 nucleotides, which means that the most active subjects had telomeres the same length as sedentary individuals up to 10 years younger, on average." When pairs of twins with different levels of physical activities were subsequently analyzed, similar results were shown.
The authors suggest a few mechanisms by which more sedentary lifestyles might contribute to telomere degeneration. One could be damage to cells caused by exposure to oxygen, called oxidative stress. Increased inflammation in sedentary persons may also create this effect Additionally, telomere length has been linked to perceived stress levels. This psychological stress may be reduced by physical activity, thus lessening its severity on telomeres and the aging process.
The authors conclude, relating this to daily life. "The U.S. guidelines recommend that 30 minutes of moderate-intensity physical activity at least five days a week can have significant health benefits," state the authors. "Our results underscore the vital importance of these guidelines. They show that adults who partake in regular physical activity are biologically younger than sedentary individuals. This conclusion provides a powerful message that could be used by clinicians to promote the potential anti-aging effect of regular exercise."
This study was supported in part by a grant from the Welcome Trust, grants from the National Institutes of Health and a grant from The Healthcare Foundation of New Jersey.
See Full Article
FDA alerts doctors about Suicide Risk of Antiepileptic Drugs
The US Food and Drug Administration (FDA) issued new information, yesterday, 31st January, to alert doctors and other health professionals about the increased risk of patients having suicidal thoughts and behaviors as a result of taking antiepileptic drugs for epilepsy, bipolar disorder, migraines, and other conditions.
The agency has just completed a review of placebo controlled studies on 11 antiepileptic drugs and found that patients who took them had two times the risk of suicidal thoughts and behaviors (suicidality) of patients who took placebo only (0.43 versus 0.22 per cent). In epidemiological terms, this is an extra 2.1 per 1,000 patients.
In March 2005, the FDA asked manufacturers of marketed antiepileptic drugs for which there were adequately designed controlled clinical trials, for the data following a preliminary analysis of several drugs that suggested an increased risk of suicidality. The agency received and analyzed data from 199 such trials covering 11 drugs.
The analysis covered 27,863 patients on the drugs, and 16,029 on placebo. Among the patients taking the drugs there were 4 suicides and 105 reports of suicidal thoughts and behaviors. Among the placebo patients, there were no suicides and 35 reports of suicidal thoughts and behaviors.
The risk of suicidality was observed to increase after one week of starting on the drugs, and stayed higher for at least 24 weeks.
There was no clear pattern of risk across age groups, and the risk was the same for all 11 drugs and all demographic subgroups, said the agency.
Director of the Division of Neurology Products in the FDA's Center for Drug Evaluation and Research, Dr. Russell Katz said:
"We want health care professionals to have the most up to date drug safety information."
" This is an example of FDA working with drug manufacturers throughout products' life cycles to keep health care professionals informed of new safety data," he added.
The agency advises patients who are presently on antiepileptic medication not to change or stop their dose until they have discussed the impact of this information with their doctor.
Doctors and other health care providers should contact their patients, their patients' caregivers and families and let them know about the increased risk of suicidal thoughts and behaviors so they can look out for any changes in behavior.
See Full Article
The agency has just completed a review of placebo controlled studies on 11 antiepileptic drugs and found that patients who took them had two times the risk of suicidal thoughts and behaviors (suicidality) of patients who took placebo only (0.43 versus 0.22 per cent). In epidemiological terms, this is an extra 2.1 per 1,000 patients.
In March 2005, the FDA asked manufacturers of marketed antiepileptic drugs for which there were adequately designed controlled clinical trials, for the data following a preliminary analysis of several drugs that suggested an increased risk of suicidality. The agency received and analyzed data from 199 such trials covering 11 drugs.
The analysis covered 27,863 patients on the drugs, and 16,029 on placebo. Among the patients taking the drugs there were 4 suicides and 105 reports of suicidal thoughts and behaviors. Among the placebo patients, there were no suicides and 35 reports of suicidal thoughts and behaviors.
The risk of suicidality was observed to increase after one week of starting on the drugs, and stayed higher for at least 24 weeks.
There was no clear pattern of risk across age groups, and the risk was the same for all 11 drugs and all demographic subgroups, said the agency.
Director of the Division of Neurology Products in the FDA's Center for Drug Evaluation and Research, Dr. Russell Katz said:
"We want health care professionals to have the most up to date drug safety information."
" This is an example of FDA working with drug manufacturers throughout products' life cycles to keep health care professionals informed of new safety data," he added.
The agency advises patients who are presently on antiepileptic medication not to change or stop their dose until they have discussed the impact of this information with their doctor.
Doctors and other health care providers should contact their patients, their patients' caregivers and families and let them know about the increased risk of suicidal thoughts and behaviors so they can look out for any changes in behavior.
See Full Article
How scratching an Itch affects the Brain
Using imaging technology for the first time to investigate the phenomenon, US researchers have revealed what goes on in the brain when we scratch, giving new clues about why the behavior brings relief and is hard to stop.
The study is the work of researchers at Wake Forest University Baptist Medical Center in North Carolina, and is published in the 31st January early online issue of the Journal of Investigative Dermatology.
Lead author and dermatologist specializing in itch-related conditions, Dr. Gil Yosipovitch said:
"It's important to understand the mechanism of relief so we can develop more effective treatments."
"For some people, itch is a chronic condition that affects overall health," explained Yosipovitch.
He and his colleagues wrote that imaging studies had looked at how the brain reacts to pruritis or itching conditions, but not what happens when the behavioral response, scratching, is going on.
The researchers recruited 13 healthy participants to undergo functional magnetic resonance imaging (fMRI), a type of scan where you can see different areas of the brain light up when the volunteer is doing different things, for instance when using limbs, thinking or talking.
A small brush was used to scratch participants on the lower leg for 30 seconds, then stopped for 30 seconds, then started again, and so on, for five minutes altogether.
The researchers found, to their surprise, that during the 30 seconds of scratching time, parts of the brain normally active when aversive emotions and memories are experienced, became significantly less active.
The parts of the brain showing reduced activity during scratching were the anterior cingulate cortex, which is linked with aversion to unpleasant sensory stimuli, and the posterior cingulate cortex, which is associated with memory. Lowest activity in these areas coincided with times when the participants felt the scratching to be most intense.
Yosipovitch said:
"We know scratching is pleasurable, but we haven't known why. It's possible that scratching may suppress the emotional components of itch and bring about its relief."
He said sometime patients find intense scratching, sometimes so hard that the skin bleeds, is the only way to relieve chronic itching.
"This is the first real scientific evidence showing that itch may be inhibited by scratching," said Yosipovitch.
He was keen to point out that scratching is not recommended because it damages the skin, but it is important to find out what is going on when people feel relief from scratching so new treatments can be developed, such as drugs that target the relevant part of the brain to produce the same effect.
As well as finding that some parts of the brain became less active during scratching, Yosipovitch and colleagues found that other parts became more active. This included activation of both sides of the secondary somatosensory cortex, which is involved in pain, and the prefrontal cortex, which is linked to compulsive behavior.
Other parts of the brain that also became bilaterally more active during scratching were the insular cortex, the inferior parietal lobe, and the cerebellum.
The activation of the prefrontal cortex, which is associated with compulsive behavior, might explain the compulsive nature of scratching behavior - the urge to keep on scratching, said the researchers.
There is one limitation to the study which could be significant, and that is the scratching was not done when itch was present. The scientists are carrying on with the research to see if they get the same results with chronic itch. They suggested that:
"Future studies that investigate the central effects of scratching in chronic itch conditions will be of high clinical relevance."
The researchers said it was important to find new treatments because moderate to severe itch bothers many people, for instance anyone with eczema, which in American alone affects 30 million people.
Another group that will benefit from new treatments are over 40 per cent of kidney dialysis patients, who have a 17 per cent higher risk of dying, probably because of lack of sleep, if they have itch.
See Full Articles
The study is the work of researchers at Wake Forest University Baptist Medical Center in North Carolina, and is published in the 31st January early online issue of the Journal of Investigative Dermatology.
Lead author and dermatologist specializing in itch-related conditions, Dr. Gil Yosipovitch said:
"It's important to understand the mechanism of relief so we can develop more effective treatments."
"For some people, itch is a chronic condition that affects overall health," explained Yosipovitch.
He and his colleagues wrote that imaging studies had looked at how the brain reacts to pruritis or itching conditions, but not what happens when the behavioral response, scratching, is going on.
The researchers recruited 13 healthy participants to undergo functional magnetic resonance imaging (fMRI), a type of scan where you can see different areas of the brain light up when the volunteer is doing different things, for instance when using limbs, thinking or talking.
A small brush was used to scratch participants on the lower leg for 30 seconds, then stopped for 30 seconds, then started again, and so on, for five minutes altogether.
The researchers found, to their surprise, that during the 30 seconds of scratching time, parts of the brain normally active when aversive emotions and memories are experienced, became significantly less active.
The parts of the brain showing reduced activity during scratching were the anterior cingulate cortex, which is linked with aversion to unpleasant sensory stimuli, and the posterior cingulate cortex, which is associated with memory. Lowest activity in these areas coincided with times when the participants felt the scratching to be most intense.
Yosipovitch said:
"We know scratching is pleasurable, but we haven't known why. It's possible that scratching may suppress the emotional components of itch and bring about its relief."
He said sometime patients find intense scratching, sometimes so hard that the skin bleeds, is the only way to relieve chronic itching.
"This is the first real scientific evidence showing that itch may be inhibited by scratching," said Yosipovitch.
He was keen to point out that scratching is not recommended because it damages the skin, but it is important to find out what is going on when people feel relief from scratching so new treatments can be developed, such as drugs that target the relevant part of the brain to produce the same effect.
As well as finding that some parts of the brain became less active during scratching, Yosipovitch and colleagues found that other parts became more active. This included activation of both sides of the secondary somatosensory cortex, which is involved in pain, and the prefrontal cortex, which is linked to compulsive behavior.
Other parts of the brain that also became bilaterally more active during scratching were the insular cortex, the inferior parietal lobe, and the cerebellum.
The activation of the prefrontal cortex, which is associated with compulsive behavior, might explain the compulsive nature of scratching behavior - the urge to keep on scratching, said the researchers.
There is one limitation to the study which could be significant, and that is the scratching was not done when itch was present. The scientists are carrying on with the research to see if they get the same results with chronic itch. They suggested that:
"Future studies that investigate the central effects of scratching in chronic itch conditions will be of high clinical relevance."
The researchers said it was important to find new treatments because moderate to severe itch bothers many people, for instance anyone with eczema, which in American alone affects 30 million people.
Another group that will benefit from new treatments are over 40 per cent of kidney dialysis patients, who have a 17 per cent higher risk of dying, probably because of lack of sleep, if they have itch.
See Full Articles
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