Biology – Page 77 – David Bradley

Periodic Post

Periodic table of sex

Mosts chemists get to see some wacky periodic tables during their careers – circular ones, spiral ones, ones that rearrange all the elements etc etc. Then there are the foody ones and then there are the giant periodic tables, the arty farty ones, the online version, the flash table.

And, then there’s the periodic table of sex.

I didn’t think it was real at first, but several sciencebase visitors have been searching for this incredible object during the last few days, so I thought I’d uncover the truth. Apparently, just such a PT exists, its elementary in the most lewd way, but is available from Amazon. Apparently, allposters.com have stopped selling it, so I’d grab one while you can: Periodic table of sex

It’s not every post I get to categorise as chemistry, sex and geek all at the same time, but this one was simply begging for it. I hate to think what good-ole Dmitri Mendeleev would have made of it though, but surely it’d make the perfect gift for the chemistry student in your life. Wouldn’t it?

Plan B contraceptive

On Friday, August 18, Barr Laboratories asked the US Food and Drugs Administration to reconsider its application to make its Plan B contraceptive available over the counter. According to FierceBiotech’s John Carroll, “Given the FDA’s sudden willingness to work out a marketing plan for the contraceptive, Barr has a good shot at finally obtaining an approval that should have come through in 2004.” Carroll reckons that the FDA now has the opportunity to show the US that science and not ideology controls how therapeutics are reviewed. “Given the Bush administration’s clear preference for ideology,” Carroll says, “the FDA may have more difficulties ahead. But for now, there’s reason for hope.”

Plan B is an “emergency” contraceptive, backup birth control, in other words, a form of contraception often referred to as a morning after pill. It comes in the form of two levonorgestrel pills, which are taken orally after unprotected sex. Plan B reduces the risk of pregnancy. Those who oppose it on ideological grounds posit that it is tantamount to an abortion despite the fact that the timescale within which it must be used can be shorter than the time within which conception generally occurs.

More on Plan B from the FDA here. The FDA announced at the end of July that, “It is proceeding to work with [Barr] to resolve the remaining policy issues associated with the marketing of Plan B as an over-the-counter option.”

Will keep you posted on this or you can subscribe for free to FierceBiotech to get the low down.

An elephant task

The ivory trade was banned by CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora) in 1989. However, illegal trade continues and as such researchers in India suggest that there is a continued need to characterize Asian elephant ivory and to be able to compare it with African ivory so that national and international laws can be implemented more effectively.

Previously, Erich Raubenheimer and colleagues in the Department of Oral Pathology, Medical University of Southern Africa, established an ivory database that would allow law enforcers to trace the source of illegal ivory and so identify poorly managed game parks, particularly in Africa. However, the ivory of Asian elephants, of which half are found in India, is more prized than African ivory. It is only the males of the Asian elephant that has tusks and they are much smaller than those of its African counterpart. Despite the illegal price differential between continents, the ivory of African and Asian elephants is indistinguishable in superficial appearance, particularly once processed, so it is almost impossible to trace the origin of tusks or a piece of work.

Read the elephant’s tale on spectroscopynow.com

Brain protein unlocked

A key protein linked to neurodegenerative diseases, such as Huntington’s and Alzheimer’s diseases, has been characterised using NMR by US researchers.

John Cavanagh, Douglas Kojetin, David Kordys, and Richele Thompson of North Carolina State University teamed with colleagues Ronald Venters of Duke University and Rajiv Kumar of the Mayo Clinic and Foundation have obtained a structure for the protein, calbindin-D28K. This protein modulates calcium levels by sequestering calcium from areas that have too much or serves as an on/off switch for further chemical reactions. It is found in the kidneys, pancreas, ocular nerve and large amounts are present in the brain. It is its role in the brain as a “bodyguard” against the action of the enzyme caspase-3 that links it to neurodegenerative diseases. By binding to and inhibiting caspase-3, calbindin D28K prevents the formation of damaging plaque and tangle formation in the brain, which are hallmarks of neurodegenerative disease. The structure of this key protein has remained elusive, until now.

Read on…

A hearty approach to female sexual dysfunction

Heart drugs are proving rather useful to pharma companies hoping to find lucrative treatments of another kind of disorder, that maybe involves the heart, but mostly involves the loins.

A heart drug that went into clinical trials in the 1990s has become the linchpin for efforts to develop a medication to treat female sexual arousal disorder (FSAD), researchers are reporting. An estimated 40 percent of women have FSAD or another form of female sexual dysfunction, the difficulty or inability to find satisfaction in sexual expression.

Compounds that sustain the activity of vasoactive intestinal peptide (VIP) are a major target of drug research efforts. VIP controls blood flow to the vagina, and decreased blood flow is believed to be one factor in female sexual dysfunction. VIP is degraded in the body by several enzymes, including an enzyme called NEP. Blocking NEP thus allows VIP to continue working.

David Pryde and colleagues at Pfizer in the UK (the company that brought us Viagra) began work with Candoxatril, a powerful NEP inhibitor tested in the 1990s for chronic heart failure. By re-engineering Candoxatril’s molecular structure, they developed a compound with the key actions needed for an FSAD drug.

The new compound blocks NEP, takes effect rapidly, and continues having an effect for a relatively short time. “The compound demonstrates excellent efficacy in a rabbit model of sexual arousal and was expected to be similarly efficacious in humans,” the researchers state in the Journal of Medicinal Chemistry. The compound is undergoing clinical evaluation as a potential treatment for FSAD.

Nitroglycerine and Sex

Nitroglycerine is best known for being the explosive substance you daren’t drop if you’re in a 1950s B movie. But, it also has several medical applications including acting as a vasodilator in the treatment of angina. It was in searching for novel and patentable drugs with similar activity that led to the discovery of Viagra, an experimental drug originally destined for the heart, which found itself pumping blood in an altogether different physiological venue.

Now, nitrogylcerine, or glycerine trinitrate as The Times (London) referred to it yesterday, is set to enter clinical trials as a topical alternative to Viagra and other impotence treatments.

Topical, you say? Doesn’t that mean it has to be rubbed in?

Indeed, Futura Medical in collaboration with GlaxoSmithKline, hope to market a gel that would be applied directly to the penis, cause vasodilation, and that blood pumping we mentioned earlier. The trials will also investigate the effects the gel has on women who share the experience of topical application with a male partner. Why the ladies don’t get their own separate trial The Times does not say. Of course, nitroglycerine is well known for causing headaches, so there’s a little, or big, wedge of irony in any such trial, surely?

Futura and GSK expect the new product codenamed MED2002, for some odd reason, to pass muster with the regulators in 2008 (so why didn’t they call it MED2008?) and be marketed soon thereafter as an over-the-counter, or maybe under-the-counter-in-a-brown-paper-bag, product.

In the meantime, we now have another product for the spammers to add to their list of fake Rx sales, so watch out for spams with subject lines containing – MED2oo2, M@d2002, Medd2002, etc etc, ad infinitum.

Seat of Female Libido Revealed

Over on Digg, there’s news that the organ in the brain responsible for female sexual response has been found. As one might expect, there are lots of sexist comments posting very early and at an alarming rate from the members: Female Libido

The actual news item in question can be found here, written by my good friend at New Scientist, Andy Coghlan.

Owl pellet dissection

A friend of mine is into nature conservation in a big way and one of the tools of the trade, which to the outsider may seem rather odd, is owl pellet dissection. I had a go at dissecting an owl pellet myself, here you can see the results

Owl pellets are the regurgitated remains (bones, feathers and other indigestibles) that accumulate in this bird of prey’s gizzard after it dines on small rodents and other critters. The dessicated pellets are to be found lying where they are discarded by the owl and can provide important information about what critters are being preyed on in owl territory.

The only way to get at that information, however, is to tease apart the pellet with tweezers and other implements to extract the bones from the tangle of hair and other detritus. It needs a steady hand, a keen eye, and a lot of patience. What you will find within is quite amazing though, tiny jaw bones and skulls, femurs, tibias pelvic bones and more.

Identifying which bone belongs to which creature takes even more patience, but it is possible and provides useful insights into the prevalence or otherwise of particular small mammals in a given area where owls prey.

For more on owl pellet dissection, check out this site http://www.kidwings.com/owlpellets/.

The reason I bring it up (pardon the pun) today, is that owl pellet dissection was the hot new search phrase on the sciencebase site this last month, with dozens of visitors all flapping for information on the subject. It’s not a topic that’s been searched for here before, so I thought I’d provide some background in case we have another flutter of en-raptor-ed activity.

Herring Gulls fighting

These two birds I photographed in my in-law’s garden were anything but lovebirds, although they might look like they were dancing seconds before and seconds after they were tearing each other’s feathers off and spitting blood. This didn’t seem to be a bar-room brawl between chums fighting over fishy scraps, these two were at it for a good half an hour. It has to have been a territorial or mating rights argument of some sort.

Nature really is red in beak and claw.

Erotic brain

What a surprise! Medical researchers have discovered that women’s brains light up when they look at erotic images just as men’s brains do.

Researchers at Washington University School of Medicine in St. Louis measured brainwave activity of 264 women as they viewed a series of 55 colour slides that contained various scenes from water skiers to snarling dogs to partially-clad couples in sensual poses.

What they found may seem like a “no brainer.” When study volunteers viewed erotic pictures, their brains produced electrical responses that were stronger than those elicited by other material that was viewed, no matter how pleasant or disturbing the other material may have been. This difference in brainwave response emerged very quickly, suggesting that different neural circuits may be involved in the processing of erotic images.

“That surprised us,” says WUSTL’s Andrey Anokhin, “We believed both pleasant and disturbing images would evoke a rapid response, but erotic scenes always elicited the strongest response.”

As subjects looked at the slides, electrodes on their scalps measured changes in the brain’s electrical activity called event-related potentials (ERPs). The researchers learned that regardless of a picture’s content, the brain acts very quickly to classify the visual image. The ERPs begin firing in the brain’s cortex long before a person is conscious of whether they are seeing a picture that is pleasant, unpleasant or neutral.

Previous research has suggested that men are more stimulated by erotic images than women. Anokhin says the fact that the women’s brains in this study exhibited such a quick response to erotic pictures suggests that, perhaps for evolutionary reasons, our brains are programmed to preferentially respond to erotic material.

“Usually men subjectively rate erotic material much higher than women,” he says. “So based on those data we would expect lower responses in women, but that was not the case. Women have responses as strong as those seen in men.”

So when one sees statistics on net usage that reveal porn accounts for 80% of traffic, it might not just be males who are using up all that bandwidth? Really? Well, I never!

What’s most intriguing though, is that when one searches for the original news release on this item from WUSTL, the cached page in Google shows the context for the phrase “erotic images elicit” as being:

“Attention grabber Erotic images elicit strong response from brain … When study…”

Well, WUSTL press officer, it certainly grabbed my attention. The news release could have done with a few more pictures though!