Health and Medicine – Page 33

Needle free bird flu vaccine

A needle-free, DNA-based, vaccine against avian influenza strain H5N1 has been developed by UK company Powder Med Ltd and will soon enter clinical trials.

This new vaccine is based upon PowderMed’s proprietary system for delivering DNA
vaccines — it is a needle-free injection device that fires gold particles coated with DNA
(encoding genes specific to the flu strain) at supersonic speed into the immune cells of
the skin. This first-time-in-man clinical trial will examine the ability of a vaccine based
upon the Vietnam H5N1 avian influenza strain to protect against a potential pandemic
form of flu.

A previous study, conducted by PowderMed in the United States, demonstrated that this
vaccine technology was able to produce 100% protective immune responses in adult
volunteers to a vaccine which encoded an annual influenza strain

Of course, who’s to say H5N1 will be the cause of the imminent bird flu epidemic or indeed that any avian influenza strain will be the next big viral attack on the human race. There are also sorts of terrifying possibilities lying dormant in exotic hosts the world over…think SARS…think HIV…think ebola…

This is my report from the Royal Society on emerging viral infections

Chemical panacea

Could researchers in Australia have developed a pharmaceutical panacea to beat all those herbal remedies offered in a multitude of spam emails and websites that claim to cure everything. They are working pre-clinical models of a new class of drug that could treat a range of problems from inflammation and cancer to eye and heart disease.

Certain types of skin cancers, age-related macular degeneration (AMD) and diabetic retinopathy are likely to be among the first uses for the drug, which has already shown efficacy in pre-clinical models.

“This may be a ‘one-size fits all’ therapy, because it targets a master regulator gene called c-Jun which appears to be involved in all of these diseases,” explains Levon Khachigian, of the Centre for Vascular Research (CVR), at the University of New South Wales. “c-Jun is an important disease-causing gene,” adds Khachigian. “It stands out because we don’t see much of it in normal tissue but it is highly expressed in diseased blood vessels, eyes, lungs, joints, and in the gut — in any number of areas involving inflammation and aggressive vascular growth.

The experimental drug they are testing goes by the enigmatic name of Dz13, and with equal enigma behaves like a secret agent finding its target, c-Jun, and killing it point blank. “It is a specific, pre-programmed ‘molecular assassin’,” says Khachigian.

He and colleagues report full details in Nature Biotechnology this month. The next step will be to test the drug in a small human trial on non-melanoma skin cancers. “If such a trial were successful, it would be a significant development given the high rates of skin cancer and because the main treatment currently is surgical excision, which can cause scarring,” said Khachigian.

A cooling hot drink

The current heatwave in England has had countless old wives, and a few elderly husbands, calling for a nice cup of tea to cool them down. And, when I say tea, I’m not talking none of that chilled variety that comes in peach and lemon and all sorts of other gawdy flavours, I mean a nice cup pored from a cosy-covered pot, with a splash of semi-skimmed milk and a couple of lumps of sugar (ten if you’re a builder or plumber, of course). So, what’s going on? Why drink a hot drink when it’s hot and you want to cool down.

Physically, it’s an illogical thing to do, Captain. Add something hot to a body at a lower temperature and the cooler body will absorb heat energy from that hot something and its temperature will rise, surely?

Physiologically, things might not be so clear-cut. Drink a hot drink, and yes, the temperature of your stomach’s contents will rise, but this will also cause a slight hastening of the heart, expanding blood vessels across the skin, and an increase in sweating as the brain switches on the various feedback-controlled temperature regulators.

It’s that word ‘feedback’ that provides a possible clue as to why a cup of hot tea might have gained its reputation among English old wives as a good coolant. Feedback loops always have a time delay. So, the instant burst of heat that comes from sipping on a nice cup of tea will inevitably bring you out in a bit of a sweat, raise your heart rate etc, but those compensatory measures take time to be reversed, possibly more time than it takes for the contents of your gut to reach ‘body temperature’ again. So, their cooling effect may just last a little longer than is actually needed to get you back to normal temperature and so you may end up a little cooler than when you started.

All that said, I don’t think our temperature feedback systems are that tardy. The real reason that old wives perceive a hot cup of tea to have a cooling effect is probably more to do with interrupting whatever activity it was that made them hot in the first place, partaking of the cup-of-tea creation ceremony, and sitting down in a darkened room with their feet up to drink it.

I could be wrong, and now that the storms are on their way this atypical English weather is likely to be replaced with the more usual wet and grey with which visitors become so familiar.

Now, where did I put those teabags…?

Chronic fatigue diagnosis

The cause of CFS, also known as myalgic encephalomyelitis (ME), post-viral fatigue syndrome (PVFS), is not yet known and its symptoms are broad, ranging from fatigue, pain, muscle weakness, and depression to digestive disturbances, immune system weakness, and breathing problems. Moreover, there is no simple diagnostic test for the disease and patients often rely on a sympathetic physician to recognise the problem, but who, nevertheless, does not necessarily have the tools to offer a definitive answer nor an effective treatment. An objective clinical diagnostic test would make understanding and treating this disease far easier. Japanes researchers have now used a type of infra-red spectroscopy to distinguish between plasma from CFS patients and healthy volunteers. They reckon a non-invasive test will be available soon.

More…

Playing tag to detect heart problems

New research using magnetic resonance imageing (MRI) is challenging conventional views regarding atherosclerosis and latent heart problems in patients that otherwise appear healthy.

By tagging different tissue prior to a scan, researchers can obtain a detailed view of the movement and function of those tissues. Now, by studying subjects in the Multi-Ethnic Study of Atherosclerosis (MESA) project, Joao Lima of the Department of Radiology, at Johns Hopkins University, in Baltimore, Maryland, and colleagues there and in five other centres, have investigated whether an increase in the thickness of the carotid artery (so-called intima-media thickness, or IMT) can be related to reduced heart function. The MESA study is a prospective observational study including four ethnic groups and the participants have no clinical cardiovascular disease.

You can read the full story in the first July update of spectroscopyNOW.com

Beer vs Wine

Beer or Wine? The choice is yours! Beer is better for you than wine, apparently. Beer contains valuable B vitamins, such as B12, folic acid and niacin, as well as antioxidants, such as polyphenols and ferulic acid. Which makes it the healthier choice, contrary to popular opinion. her also contains soluble fibre, which is good for digestion. Even the “active” ingredient in alcohol, whether from beer or wine, allegedly helps keep arteries clear of blockages.

So, who is making this startling claim?

Apparently, none other than the chairman of the food science department at the University of California at Davis, Charles Bamforth.

Interestingly, Bamforth is UCB’s Anheuser-Busch endowed professor and author of the book Beer: Health and Nutrition. ‘People say red wine is key to that,’ Bamforth says, ‘But beer, if you looked at it holistically, is healthier than wine. But it is not perceived that way.’

Anheuser-Busch? Isn’t that the company that makes Bud?

Even more intriguingly, the budweiser.com site announces that you have to be over 21 to enter its site and you have to tap in your birthday before you can….like teens aren’t going to just put 01-01-50 or something similar. By the way, it’s tough if you were born in 1900 – no Bud fest for you!

Britain unprepared for flu pandemic shock

Reuters is reporting that general practitioner Steve Hajioff warns that the UK’s preparations for a bird flu pandemic are inadequate.

The UK is on high alert for bird flu following the dead swan incident in Scotland and is stockpiling vaccine. Hajioff, however, suggests that the impact on infrastructure of an avian influenza epidemic would be like a thousand 9/11’s. “In the present day, you are talking about five million people across Europe and hundreds of thousands in the UK. It’s like 1,000 September 11ths all at once,” he said.

The insensitivity of such a phrase aside, Hajioff went on to tell BBC radio: “I’m a GP and I can prepare my surgery, but if the electricity company that supplies my power has not prepared, then I am not going to be able to treat patients.”

What worries me, is whether or not Dr Hajioff is qualified to offer a new thread to the scare-mongering surrounding bird flu in this way. Maybe he is. His website tells us he “is a broadcaster, a healthcare informatics consultant, a public health physician, and a writer.” It goes on to say that he has a particular interest in international health systems, communicable disease control and electronic data security.” Interestingly(?), “For fun, he paints, skis, cooks and drives his MG. He is also a keen MIDI musician.”

And, seeing as the reporting on his offering to BBC Radio suggests he didn’t actually tell the audience anything that isn’t fairly obvious then perhaps he is qualified after all.

Just for the record, despite the continued scaremongering for almost every H5N1 is yet to mutate into a human transmissable form and the evidence points to the likelihood that such a mutant would have less virulence among humans than H5N1 has among birds.

We’ll see.

Time running out for MRSA

Apparently, “most doctors” have not heard of the “new” killer big that left a nine-year old boy with lungs full of holes after a bad scrape to his knee. At least that’s according to an article in Time magazine. And it seems that readers of the Digg site too were at a loss to understand how this bug could have remained so anonymous. So, what is this mystery bug?

Well, it’s none other than MRSA, or methicillin resistant Staphylococcus aureus, sometimes labelled as multiple resistant, mentioned numerous times on this site and countless others. This nasty little microbe, as it’s name would suggest is a strain of S aureus that has evolved resistance to methicillin, and various other antibiotics. It’s well known in the UK, Japan and elsewhere. It’s certainly been the subject of multiply repugnant media scare stories about killer hospitals in the UK for the last couple of years at the very least. Indeed, its existence has prompted the UK government in its usual kneejerk response to media scare stories to have the whole of the National Health Service re-organised so that everyone has to use an antiseptic gel, wet wipe or whatever every single time they enter a ward, exit a ward, breathe in, breathe out…….

The variation on theme cited by Time, however, adds another couple of capitals to that acronym C and A for community acquired MRSA. This bug has hit the streets in other words.

The street-wise MRSA is not such a tough cookie as its hospital-dwelling cousin. It does respond to antibiotics, but it does spread much more easily among otherwise healthy people, says Time, and could, under pressure, evolve significant resistance. The strain that nine-year old picked up from a knee scrape spread through his body very rapidly indeed. But, his is not an isolated case. Never mind H5N1 and SARS, it’s MRSA you have to watch.

Schizophrenia drugs warning for journalists

Many years ago, when I was writing on a weekly basis for New Scientist, in fact long before the magazine even had a web presence, I wrote a short news item about a new class of drugs for treating the symptoms schizophrenia.

Within days of that issue hitting the shelves I received several letters from desperate readers asking where they could get hold of the drug. Unfortunately, it was very much in the experimental stages and as far as I am aware the compound in question never did make it to market. A lesson learned.

A press release from the American Chemical Society announces yet another development in the drug discovery process for schizophrenia. At first, I was reluctant to follow it up, but even though once again the discovery is preliminary and not yet at the pharmaceutical marketing stage, it is an interesting enough lead to warrant a mention.

Indeed, scientists are reporting progress toward treating a long-neglected group of symptoms that impair the functioning of people with schizophrenia. This chronic, highly debilitating disease affects 3 million people in the United States. Schizophrenia involves “positive” symptoms (hallucinations and delusions), “negative” symptoms (apathy and withdrawal) and cognitive symptoms (such as difficulty in filtering out unimportant sensory information).

Despite major advances in drug therapy for the positive and negative symptoms, cognitive symptoms – which appear in 85 percent of patients – go largely untreated today. A team of researchers at Pfizer, including Bruce Rogers, report the discovery of a potential drug for schizophrenia’s cognitive symptoms. Their study will appear in the June 29 issue of the Journal of Medicinal Chemistry.

The new compound, PHA-543,613, is believed to mimic nicotine’s biochemical effects in the brain in enhancing cognition. More than 80 percent of people with schizophrenia are heavy smokers, and scientists believe smoking may be a form of self-medication for the disease. PHA-543,613 improved cognitive functioning in animal tests, including object recognition and P50 gating – a common test to measure auditory information processing. The researchalso provides additional support for the hypothesis that such compounds represent a novel, potential pharmacotherapy to treat the cognitive deficits in schizophrenia. One has been shown in separate reports to improve cognitive functioning in healthy human volunteers.

You can find the paper through its DOI – 10.1021/jm0602413 – here. Just cut and paste the number into the yellow science toolbox on that page and click the DOI go button. If you’d like to add this toolbox to your website, please grab the simple javascript and slot it into a suitable position on the page. The team at the Usefulchem blog are already using the companion science search box.

Lead in China’s children

Researchers in Beijing have carried out a meta-analysis of AAS and ICP-MS results published during 1994-2004 to obtain a countrywide picture of how the level of lead in children’s blood is changing and how where they live effects their exposure to this toxic element.

Perhaps predictably, the team found that those children living in urban or industrial regions had much higher levels of lead than those living in rural areas. The figures they reviewed also contrast sharply with the children’s western counterparts who have much lower lead levels on average. The issue is a matter of significant public health importance for China, the researchers say.

Exposure to lead can affect the central nervous system and affect learning ability and growth. It is ubiquitous in the environment and can be absorbed in the human body by inhalation and ingestion from a variety of sources such as contaminated water, soil, food, lead-containing products such as paint and from vehicle exhausts in areas where tetra-ethyl lead is still used as engine an anti-knocking agent.

More…