Author: David Bradley

Bird Flu Between People

Why doesn’t H5N1 pass from person to person as easily as it passes from bird to bird? After all, H5N1 can replicate very efficiently in someone’s lungs.

Japanese researchers now think they have an answer to this vexing question. The bird virus, they have found, preferentially binds to cells in different regions of the human airway from those favoured by human influenza viruses.

Flu viruses infecting humans and birds are known to home in on slightly different versions of the same molecule, found on the surface of cells that line the respiratory tract. Yoshihiro Kawaoka and colleagues report in today’s Nature the effect this has on patients. Whereas the version of the molecule preferentially bound by human viruses is more prevalent on cells higher up in the airway, the molecule that is preferentially targeted by avian viruses tends to be found on cells deep within the lungs, in the air sacs, or alveoli, of the lung.

This may explain why human-to-human transmission of H5N1 remains uncommon, explain the authors. The virus may preferentially enter cells deep down inside the lungs, meaning that an infected person is less likely to spread the virus by coughing or sneezing. The researchers add, however, that should the virus ever acquire the ability to infect cells higher up in the airway then it may make the leap to a human to human infectious disease.

Parallel findings are also published today in Science, by Thijs Kuiken and colleagues. They have identified alveoli type II pneumocytes, scavenging cells within the lumen of the alveoli as the cells to which H5N1 predominantly attaches. These findings are in contrast to the received wisdom that avian influenza viruses have little or no affinity for cells of the human respiratory tract.

Stretching a Point

A press release from the Journal of Investigative Dermatology describes the latest research into stretch marks. The release says stretch marks are “unsightly” and describes them as a “disorder”. Fair enough. It then goes on to discuss the finding that women with this disorder, appear to be at increased risk of pelvic prolapse. How could this be and what are the warning signs?

Like stretch marks, pelvic prolapse is a connective tissue disorder and pelvic weakness is a serious condition caused by deterioration of support structures that can result in pressure, pain, vaginal bulge and/or urinary incontinence. The scientists who report their results explain that pelvic prolapse is an extremely under-reported condition with no official data as to how many women suffer from the condition. Tracked cases in the US, however, show more than 300,000 procedures are performed annually to repair the condition, which has been previously associated with pregnancy. This new study, however, found that stretch marks were twice as common in women with prolapse as those without, hinting at a hitherto hidden connection.

Stretch marks occur when skin is stretched beyond its usual capabilities and normal production of collagen is disrupted. As a result, scars or stretch marks form. Alexa Kimball and colleagues reviewed results from a survey issued to urogynecology and dermatology patients. Participants ranged in age from 25-90 with an average weight of 152 pounds (70 kg).

Analysis of multiple variables identified stretch marks as the only significant predictor of pelvic
prolapse. Follow-up studies will further investigate the incidence and correlation of these two connective tissue disorders and how genetic factors contribute to incidence. Research will also include prospective studies to validate findings and identify predictive markers to prevent the progression of this condition.

The paper is available through www.jidonline.org

Double your Money in Bird Flu Lottery

It’s like buying two tickets instead of one for the national lottery, you may shorten the odds ever so slightly, but there’s still very little chance of winning. That should be your first thought on hearing that the strain of avian influenza currently making the media sweat has evolved into two distinct variants. That’s the big news emerging from the International Conference on Emerging Infectious Diseases in Atlanta this week.

Rebecca Garten of the US Centers for Disease Control and Prevention reports that she and her colleagues analysed more than 300 H5N1 samples from infected birds and people between 2003 and summer 2005, and found two distinct sub-types of the virus. The genetically distinct H5N1 strain is thought to have emerged in 2005 and infected people in Indonesia.

The concern is that the existence of this variant points to an increased risk of a human-transmissable form of avian influenza emerging at some stage. Of course, the emergence of distinct strains of a single type of flu virus is nothing remarkable. Flu viruses are notoriously quick to evolve. After all, they wouldn’t be endemic in their host populations if they weren’t, as a second wave of infection would simply be defeated by the already primed immune defences. Evolution provides each successive strain with a new set of proteins to avoid detection by the immune system. Regardless, H5N1 is still a bird virus, it only very rarely infects people. It will take more than a simple single mutation to allow it to leap from a bird host environment to humans and even then, many researchers concede that it is likely to lose virulence when it does so.

Beaming up a Blind Date

Personally, I’m way past the dating game, having been happily married for several years. But, as an angsty teen with a passion for the more nerdy things in life – many of which begin with the prefixes astro-, star-, and chem- Trek Passions would have been a lifesaver. If you’re looking for love and haven’t yet found your Lieutenant Uhura, your Han Solo, or even your Ford Prefect, then this site could be the place to go. Essentially, it’s an off the dial free dating site for sci fi fans and it does exactly what it says on the tin. It interfaces lonely hearts, enables matter transportation of an amorous kind, and basically presses all the right buttons among the millions of Trekkies, Starwarsies, Clarkies, and perhaps even Wyndhamies out there.

McCoy: [to Spock] You see, I feel sorrier for you than I do for him [referring to Kirk] because you’ll never know the things that love can drive a man to. The ecstasies, the miseries, the broken rules, the desperate chances, the glorious failures and the glorious victories. All of these things you’ll never know, simply because the word “love” isn’t written into your book. Good night, Spock.

So, sign up, but watch out it’s a scary worlds out there…

Detox Kits

A sciencebase visitors attempted to spam the blog recently with an advert for his detox kits. Needless to say, this blog automatically adds a rel=nofollow tag to all comment URLs, so it’s a waste of time spamming us anyway, but moreover, all comments are moderated so that cr*pfloods are easily averted.

Anyway, if you want to find out what a detox kit is check this Google search: detox kits – Google Search

It seems that the marketing spiel claims that these kits can clear out the tell-tale signs of any drug of abuse and so help users pass drugs tests. Looks like bunk to me, nothing can “detox” your body. Metabolites have to be excreted eventually and chemical analysis would reveal the presence of even modified metabolites in your urine.

One thing that does worry me about these kits though. If they do “mop up” drugs and drug metabolites from your bloodstream then they’re going to have to be incredibly selective so as not to interfere with prescription drugs, surely.

I’d be very wary of using them (they’re rather pricey too!) to try and pass a drugs test. Much easier just to avoid those drugs of abuse in the first place.

Why Do Stars Twinkle?

Why do stars twinkle? It’s a similar effect to why a hot road looks shimmery. The turbulent atmosphere refracts the incoming starlight to different degrees so the “beam” of light reaching your eye becomes randomly distorted but deviates only minutely from its path, just enough so that it looks like the star is twinkling. It’s the bane of ground-based astronomers and is part of the reason we sent up the Hubble space telescope. However, there are techniques that can overcome twinkle.

Twinkle no more Little Star

A laser optics system can produce a guide star anywhere in the night sky of the southern hemisphere, thanks to work by scientists at Cerro Paranal in Chile, home of the ESO Very Large Telescope array. The star allows astronomers to apply adaptive optics systems to their telescopes effectively cancelling out atmospheric disturbances, better known as a star’s twinkle!

Read the latest on detwinkling in the Spotlight Newsletter

Interview with Steve Bryant

I interviewed Steve Bryant for the chemistry magazine Reactive Reports, mainly about PubChem, how and why it was set up, what are its limitations, and the various controversies surrounding this chemistry database.

Bryant had become increasingly involved with information resources because, he told me, that is the most valuable thing we can do with computers and molecular databases. Making the information as accessible to researchers as possible was to be critical. “There was a whole world of information about the bio activities/properties of small molecules that was not included in our retrieval systems in as good a way as it could have been,” he says, “I thought it be worthwhile to do as it would have a major impact on research.”

Read the complete interview in the March 2006 edition of Reactive Reports.

Antiperspirants Cause a Stink

Philippa Darbre of the University of Reading, England, has published a review of the putative health effects of organometallic compounds that mimic estrogen and could increase the burden of “aberrant oestrogen signalling within the human breast”. Of particular relevance to public health is her suggestion that the aluminum compounds used in the manufacture of underarm antiperspirants may somehow be involved in an increased risk of breast cancer. The paper is already causing a stir in the UK, however, it is also causing controversy particularly because it does not represent any new experimental evidence but draws new conclusions from other studies.

You can read the full story in Issue 53 of chemistry webzine Reactive Reports, out now!!!

Repulsive Particles

When it comes to particles, we usually think of opposites attracting – north and south, positive and negative. But, somehow particles that one might expect to mutually repel somehow manage to form clusters in solution. How this can be was the subject of a research project undertaken by Gerhard Kahl of the Institute of Theoretical Physics at the Vienna University of Technology, and colleagues. Their finding could be important for understanding how polymers become organized and improve the prospects of the burgeoning field of soft matter research.

Get the complete picture in the March issue of chemistry webzine ReactiveReports.com

Censorship

Check out Indiana University’s Censearchip. It allows you to see how search engine censorship (on Google or Yahoo) in various countries affects the search engine results pages (SERPs) you see depending on where you search from (well if you’re in China, France, Germany, and the USA. It’s quite fascinating to see the tag clouds it generates to show the differences between searching in different countries.

The tool’s developers, Mark Meiss and Filippo Menczer at the Indiana University School of Informatics, caution that ‘In order to give as accurate a comparison as possible, we’ve disabled the ‘SafeSearch’ feature that search engines use to block images with explicit violent or sexual content from their search results. Some of the images returned may be quite graphic and inappropriate for children. Please exercise caution in your searches!’

You have been warned.