Health and Medicine – Page 36

Black Cohosh and Hot Flashes

black cohosh menopause remedy According to news just in from the American Chemical Society, millions of women use the herb black cohosh (Cimicifuga racemosa) as a dietary supplement to help treat hot flashes and other menopausal symptoms. However, there are no definitive clinical trials to say whether they are wasting their money or not. Some studies report that black cohosh helps relieve menopausal symptoms such as hot flashes, while others do not.

A new study to be published May 17 in the Journal of Agricultural & Food Chemistry reveals that many of the black cohosh supplements sold across the US actually do not contain any of this plant at all. Rather, they are formulated with a related plant species that has none of the same chemical compounds or clinical applications as the native North American plant.

Edward Kennelly, Fredi Kronenberg and colleagues report that a new analytical technique, allowed them to quickly test 11 products on the market claiming to contain black cohosh. Three contained an inactive adulterant, and one contained both genuine black cohosh and an Asian imitator. Products containing only black cohosh varied significantly in the amounts of the compounds believed to relieve menopausal symptoms.

“In the US, botanical dietary supplements are regulated as foods, rather than drugs,” noted Kennelly, “The manufacturers are required to follow good manufacturing practices, so this misbranding should not occur. Unfortunately, our study shows that at least in the case of black cohosh, many manufacturers are not following the regulations.”

In other words, caveat emptor applies as always, adds Kennedy: “Consumers should be aware of this situation in order to make proper choices for their health care.”

Traditional Chinese Medicine Analyzed

HuÃ¡ngqÃ (huangqi) is a plant root used in one of the most common tonics of Chinese traditional herbal medicine with purported activity in cancer, diabetes, inflammation, and nephritis.

As such, there is a lot of interest in the active ingredients of this species as it might lead to novel pharmaceuticals against a range of illnesses. Now, researchers in China have used a powerful spectroscopic technique to identify the active chemical components of this remedy.

Sudoku to Beat Schizophrenia

Jennifer Barnett and researchers at the University of Cambridge’s Department of Psychiatry have discovered that intelligence can reduce the effects and severity of schizophrenia, bipolar disorder, depression, and other neuropsychiatric disorders.

It was already known that intelligence can protect against dementia and the effects of head injury. Now, Barnett and her colleagues have reviewed the literature to discover that intelligence can also act as a buffer against the potentially debilitating effects of schizophrenia and other disorders. They found that for people with a higher IQ, the symptoms of schizophrenia were less severe and the ability to function in daily life better than for those people of lower IQ.

The team found that a phenomenon known as “cognitive reserve” made people more resilient to disabilities arising from these disorders. Fortunately, cognitive reserve can be strengthened through education, neurocognitive activation (doing sudoku, crosswords, and other puzzles), or other treatment programs. It may also be possible to improve cognitive reserve through the use of cognition-enhancing drugs, say the researchers.

“Cognitive reserve may greatly improve our understanding of individual differences in the causes and consequences of schizophrenia and other neuropsychiatric disorders,” Barnett explains. Team leader Barbara Sahakian adds that “We are very excited about these novel results. We have known for some time that it is important to ‘use it or lose it’ with regard to ageing and dementia, but it now seems that this concept applies more widely.”

The research will appear online in the journal Psychological Medicine

You can play suduko online at Sciencebase.

Antibiotics for asthma

Researchers at Imperial College London have demonstrated that an antibiotic is effective at treating acute asthma attacks, potentially providing a new way to help asthma sufferers.

The team found that the antibiotic, telithromycin, can hasten the recovery time of patients who have had asthma attacks by three days, as well as reducing their symptoms and improving lung function. Treatment for some serious asthma attacks can involve the use of steroids, which help control inflammation of the lungs and bronchodilators to open airways. However, telithromycin, an antibiotic was tested as part of the TELICAST (TELIthromycin, Chlamydophila and ASThma) study on 278 patients at 70 centres around the world, including St Mary’s Hospital, London to see whether asthma therapy could be added to the drug’s repertoire.

The patients were enrolled in the study within 24 hours of an acute asthma attack requiring acute medical care. They were then randomised double blind to either ten days oral treatment with a single 800mg dose of telithromycin daily, or placebo in addition to usual treatment. Symptoms and lung function for the patients in the telithromycin group improved significantly compared to those in the placebo group, with improvements being around twice as great at the end of the treatment period. Recovery time was also cut from an average of eight days for the placebo group, to five days for those in the telithromycin group.

Sebastian Johnston from Imperial College London, who led the research, said: ‘Traditionally antibiotics have not proven effective in treating asthma attacks, but this development could open up a whole new area of research in the treatment of asthma.”

Pox Virus Undressed to Make its Entry

Geoffrey Smith of Imperial College London and colleagues have discovered how Vaccinia, the smallpox vaccine, enters cells and causes infection. The findings shed light on a novel mechanism by which active pox viruses can infect people. Apparently, the Vaccinia virus sheds its outer lipid membrane to enter cells. This naked entrance mechanism is unique in virology and could pave the way for a range of new antiviral drugs.

Many viruses, such as the H5N1 avian influenza virus, are surrounded by a single lipid membrane, or envelope. To enter cells this membrane has to be shed. Previously, all enveloped viruses were thought to shed their lipid membrane by fusion with a cell membrane which allows the viral core to be released into the cell.

In contrast, the extracellular form of Vaccinia virus has two lipid membranes, meaning a single fusion event will not release a naked virus core into the cell. The Imperial team has found that interactions between negatively charged molecules on the cell surface and sugar-linked proteins, glycoproteins, on the virus’ surface split the virus outer envelope without fusing, allowing the poxvirus to enter the cell.

As well as discovering how the double membrane problem is solved, the researchers demonstrated that these multiply charged, polyionic, compounds can destroy the poxvirus even days after infection has started. Disrupting the outer membrane with polyanionic compounds exposes the virus, allowing antiviral antibodies to be more effective. The disruption of the outer membrane also limits the spread of the virus in the body.

“This work has uncovered a completely novel biological process,” Smith, “It increases our understanding of how viruses can manipulate biological membranes and will help the development of new drugs against poxviruses, such as variola virus, the cause of smallpox.”

Details in Proc Nat Acad Sci

Bird Flu Poll

H5N1 at last reached British shores this month and now both the Eastern and Western seaboards of the USA are on tenterhooks. In the spirit of serious scientific debate, I’ve posted a poll all about avian influenza on the SciScoop Science Forum.

So, are we all doomed to be tarred and feathered or is it just a load of media fluff and feathers? You decide.Meanwhile, check out SciScoop regular contributor Chad’s excellent ongoing posting on the bird flu story on SciScoop.

Cat Flu Among the Pigeons

Dodgy mixed metaphors in Nature press releases aside, an important paper published this week and leaked by the media ahead of embargo expiration (tut, tut) reports how the first case of a domestic cat dying from the avian influenza H5N1 virus in Thailand in 2004 hit the airwaves.

Since then, numerous cases have emerged globally, including the death and euthanasia of 147 captive tigers fed virus-infected chicken carcasses. As feline fatalities increase scientists are now urging that the role cats might play in spreading avian influenza and the evolution of the virus ought to be reconsidered.

Albert Osterhaus and colleagues at Erasmus University in the Netherlands discuss the latest reports and experimental studies that underline the vulnerability of cats to H5N1 virus infection and the risks that cats pose to agencies fighting its global spread. They emphasise how cats can be infected with the virus through contact with domestic and wild birds, and then excrete the virus from the respiratory and digestive tract, sometimes transmitting infection to other cats. They also note that cats fed virus-infected chickens can be infected directly through the gut. This worryingly novel route for influenza transmission in mammals could be a serious cause for concern.

Despite this evidence, the authors argue that the impact of cats on the epidemiology of the avian influenza virus is still being overlooked by key organizations such as the World Health Organization (WHO).

The authors conclude that they cannot rule out the possibility of the virus mutating into a more dangerous strain in feline and other mammalian hosts, and suggest increased surveillance and precautions to be taken to prevent the virus leaping to humans.

More information in Nature this week.

Vestigial Virgins

Ivan Pedrosa and colleagues at Harvard have demonstrated how MRI (magnetic resonance imaging) can help rule out a diagnosis of acute appendicitis during pregnancy when ultrasound results are inconclusive.

Appendicitis during pregnancy can lead to numerous complications, not least because of the need for emergency surgery. Ultrasound has been used to reveal an inflamed appendix, but it is not always conclusive, especially in the late stages of pregnancy.

The full story now in the MRI section of SpectroscopyNOW.com

Bird Flu Vaccine

The BBC reports today that it has been given exclusive “access” to a Belgian trial of a new bird flu vaccine.

400 volunteers signed up to receive either the new vaccine or a placebo in the randomised double-blind trial of the GlaxoSmithkline vaccine. 399 said they were doing it for humanitarian reasons, one admitted it was for the money (300 euros) and the experience. Let’s just hope the “experience” isn’t as interesting as that suffered by volunteers in another recent trial for a drug that also triggers changes in the body’s immune system.

Benzene in Soft Drinks

Benzene Structure This is an update to my earlier posting about benzene in soda.

Today, March 31, the UK’s Food Standards Agency has published the results of an analytical survey of benzene levels in 150 soft drinks on the market in the UK. They state that contrary to fears, benzene was not detectable in the majority of products sampled.

However, four products did contain trace amounts of benzene that are above World Health Organization (WHO) guidelines for drinking water and the FSA has ordered these to be withdrawn. An FSA spokesman explained that while the levels of this potential carcinogen are very low it is prudent for the sake of public confidence that products that contain more than the WHO suggests is acceptable should not be sold.

The issue does not address the growing fear of risk that has become endemic in Western society, but once again reinforces the negative image of “chemicals” among consumers. This is despite the fact that one of the ingredients that leads to the benzene forming in such products in the first place is vitamin C!

The FSA spokesman adds that “The levels of benzene reported in this survey will only make a negligible impact on people’s overall exposure to benzene and so any additional risk to health is, therefore, likely to be minimal.” This should be considered in the much wider context of everyday benzene sources to which a lot of people are exposed on a daily basis, vehicle fuels and cigarette smoke, for instance.

The four drinks being withdrawn from supermarket shelves all list sodium benzoate and vitamin C (ascorbic acid) as ingredients and are: Co-op brand “low calorie bitter lemon”, Popstar “still sugar free lemon & lime drink”, Morrisons brand “no added sugar pineapple & grapefruit crush”, and Hyberry “High juice no added sugar blackcurrant squash”.

It is only certain batches of these products that contain benzene at levels above WHO guidelines, but the FSA is essentially presenting the drinks industry with an ultimatum that could see an end to a consumer issue that has been known about for at least fifteen years.

More information on the FSA report is available here.