Saturday, October 24, 2009

Ho hum! Here we go again: Traffic pollution may be to blame for miscarriages, say researchers

It's quite amazing how these guys pick out one factor and confidently say THAT is the cause. There is any number of reasons why winter babies might not survive. Illness is greater in winter, for instance. Only the last paragraph below shows some sense

Traffic pollution may be to blame for miscarriages, researchers believe. A study of 400 women having IVF treatment in Brazil found that those who became pregnant in winter, when pollution levels are particularly high, were twice as likely to miscarry in the first eight weeks as those who conceived at other times of the year. The researchers say that the findings may be relevant to other countries, including Britain, where air pollution regularly exceeds the levels considered safe by the World Health Organisation.

Paulo Marcelo Perin, from the University of São Paulo, told the American Society for Reproductive Medicine conference in Atlanta, Georgia, that miscarriage rates were 20 to 30 per cent in winter months, compared with 10 to 15 per cent in other seasons. Air quality is thought to be worse in winter because increased rain and fog bring down levels of sooty “particulate matter”, known as PM10s and emitted by industry and traffic, to where they can be breathed in by people.

Dr Perin said that women exposed to levels of PM10s only slightly above the recommended safe limit (50 micrograms per cubic metre) had a greater chance of losing a baby. “We saw a significant increase in the miscarriage rates in winter,” he said. “There was a 2.5 fold increase in pregnancy loss [in women] exposed to high levels of pollution. “Our previous studies have shown higher implantation failure rates when women are exposed to pollution. Our latest study found that air pollution significantly decreased the cell population.

“When you have a decrease in cell mass you compromise embryo viability. Because diesel is a major component of air pollution we can assume most of the effect is from diesel.”

A second study by American researchers on 7,500 women undergoing IVF also suggested a decline in fertility due to exposure to nitrogen dioxide, another common air pollutant.

Up to one in six couples in Britain have problems conceiving naturally and more than 37,000 women received fertility treatment in the UK in 2007, the latest year for which figures are available.

Stuart Lavery, the director of the IVF unit at Hammersmith Hospital, in London, said that it was possible that pollution could affect the chances of pregnancy but more studies were needed to confirm the effect. He added: “This is an area that is crying out for good research.”


Patients on anti-obesity drug liraglutide lose a stone in 20 weeks

Long term side-effects would need to be evaluated

Patients given a new anti-obesity drug lost more than a stone in weight in five months — almost twice as much as those taking other treatments — trial results have shown. A study of liraglutide, which is marketed as Victoza and given by injection, suggests that it can promote dramatic weight loss and help obese patients to avoid the onset of type 2 diabetes.

The Europe-wide trial of 564 people with a body mass index between 30 and 40 — normally defined as obese — found that high doses of the drug were much more successful than the anti-obesity pill orlistat or a placebo injection.

The average weight loss of participants given a daily 3mg dose of liraglutide, coupled with an exercise and diet regime, was 15.9lb (7.2kg), compared with 9lb (4.1kg) for those taking three orlistat pills a day. Even smaller doses of 1.2mg, 1.8mg and 2.4mg reduced weight by 10.5lb (4.8kg), 12.1lb (5.5kg) and 13.9lb (6.3kg) respectively. Those given the dummy treatment lost only 6.2lb (2.8kg).

The findings, published online in The Lancet, also showed that a higher proportion of individuals (76 per cent) lost more than 5 per cent of their body weight with 3mg of liraglutide than orlistat (44 per cent) and the placebo (30 per cent). The injection works by intensifying the feeling of being full, and by reducing the speed at which the stomach empties.

During the past 20 years the rate of obesity has risen three-fold, and in some European countries more than 30 per cent of the population is obese. About 50 per cent of all adults in Europe are classified as overweight. Obesity increases the risk of hypertension, diabetes and atherosclerosis — all risk factors for cardiovascular disease.

Arne Astrup, of the Department of Human Nutrition at the University of Copenhagen, Denmark, and his team studied the effect of liraglutide on the weight of obese individuals without type 2 diabetes.

At the start of the study, about a third of patients in each group had pre-diabetes — with higher than normal blood glucose levels but not yet bad enough to qualify as diabetes. A report from Diabetes UK, published this week, suggested that 7 million Britons suffer from pre-diabetes, putting them at 15 times greater risk of developing type 2 diabetes.

The authors concluded: “Treatment with liraglutide, in addition to an energy-deficit diet and exercise programme, led to a sustained, clinically relevant, dose- dependent weight loss significantly greater than that with placebo and orlistat. “Liraglutide offers a new mode of action for the treatment of obesity and improved efficacy compared with currently available therapies. Its effect on pre-diabetes suggests that it might be important for treating obese pre-diabetic individuals.”

They added that further studies, over longer than five months, were needed to establish the long-term risk-benefit profile for liraglutide. Nausea and vomiting had occurred more often in individuals on liraglutide than in those on the placebo, but adverse reactions were mainly transient and rarely led to the patient stopping treatment.

In an accompanying commentary, George Bray, of the division of clinical obesity and metabolism at Pennington Biomedical Research Centre, Louisiana State University, said: “[This] important report shows a dose-related reduction of food intake and bodyweight in overweight and obese individuals treated with liraglutide.” He added that one limitation to the use of drugs such as liraglutide was that they required an injection. “Whether long-term use of an injectable drug is palatable as a treatment for obesity is yet to be established,” he said.


Viral Link to Chronic Fatigue

Chronic fatigue syndrome (CFS) is a complex and debilitating disorder that is often linked to immune system dysfunction but whose cause(s) remain mysterious. Lombardi et al. (p. 585, published online 8 October; see the Perspective by Coffin and Stoye) now present a tantalizing new lead. In blood samples from 101 patients with well-documented CFS, over two-thirds (68) contained DNA from a recently described human gammaretrovirus, xenotropic murine leukemia virus–related virus (XMRV), which possesses sequence similarity to a murine leukemia virus. Cell culture assays confirmed that XMRV derived from CFS patient plasma and from T and B lymphocytes was infectious. Although the correlation with CFS is striking, whether the virus plays a causal role in the disorder remains to be determined. Interestingly, nearly 4% of the 218 healthy donors tested were positive for XMRV, which suggests that this virus—whose pathogenic potential is unknown—may be present in a significant proportion of the general population.


Journal abstract:

Detection of an Infectious Retrovirus, XMRV, in Blood Cells of Patients with Chronic Fatigue Syndrome

By Vincent C. Lombardi et al.

Chronic fatigue syndrome (CFS) is a debilitating disease of unknown etiology that is estimated to affect 17 million people worldwide. Studying peripheral blood mononuclear cells (PBMCs) from CFS patients, we identified DNA from a human gammaretrovirus, xenotropic murine leukemia virus–related virus (XMRV), in 68 of 101 patients (67%) as compared to 8 of 218 (3.7%) healthy controls. Cell culture experiments revealed that patient-derived XMRV is infectious and that both cell-associated and cell-free transmission of the virus are possible. Secondary viral infections were established in uninfected primary lymphocytes and indicator cell lines after their exposure to activated PBMCs, B cells, T cells, or plasma derived from CFS patients. These findings raise the possibility that XMRV may be a contributing factor in the pathogenesis of CFS.

Science 23 October 2009: Vol. 326. no. 5952, pp. 585 - 589

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