Author: David Bradley

Solvent abuse

Adolescent drug use has fallen overall since the late 1990s, but the “recreational” use of solvents is on the increase. Solvent, or inhalant, abuse is now the fourth most abused drug among US teens according to NIDA.

Inhalants, which include volatile organic compounds such as butane and aromatic hydrocarbons (like toluene) activate the same areas of the brain as do other drugs of abuse. However, understanding their precise mode of action has not been clarified until now.

Toluene is found in paint thinners, varnishes and even nail polish remover and is commonly abused and new research shows that it stimulates dopamine release in specific regions of the brain known as drug reward pathways. The results, obtained by Arthur Riegel and colleagues at the Vollom Institute, in Portland, Oregon, suggest that the brain interprets inhalation of toluene as a rewarding experience which can result in continued abuse and re-abuse.The findings could help in developing strategies to prevent and treat addiction to substances containing toluene.

Surprisingly, researchers also found that toluene-containing substances are most effective at low concentrations. Since toluene is rapidly absorbed by the brain, this might explain why the preferred mode of delivery is by “huffing” or “sniffing”. Sniffing is frequently considered a harmless recreational or party drug but unlike other drugs, even a single session of inhaling the compound can disrupt heart rhythms enough to cause cardiac arrest and lower oxygen levels enough to cause suffocation. Not a good thing.

The research is published today in the journal Neuropsychopharmacology.

Obesity and colon cancer link

Obesity is a major risk factor for colon cancer, but until now medical scientists were at a loss to explain why. Now, a study of on three human colon cancer cell-lines has demonstrated that the “fat hormone” leptin may enhance the growth of colonic cancer cells. The discovery not only offers an explanation as to the underlying cause of the increase colon cancer risk in obesity but could lead to a new approach to fighting this type of cancer.

The hormone leptin is released by fat cells, adipocytes, so the higher your body fat content (calculate your body fat now), the higher the concentration of leptin in your blood stream is likely to be. Leptin plays a key role in regulating metabolism, body weight and energy expenditure.

According to previous research, people who are obese are two to three times more likely to develop colon cancer than their leaner counterparts. Other research revealed that some colon cancer cells carry receptors for leptin.

Now, scientists at the University of California San Diego School of Medicine believe they have found the link.

“These results may explain why obesity increases a person’s risk of colonic cancer, and the fact that we have shown how leptin stimulates these cells means that drug companies may be in a better position to develop new treatments against the disease,’ says UCSD’s Kim Barrett.

The team grew cancer cells in the laboratory and found that leptin could stimulate their growth. In two out of three cell lines, leptin also blocked normal programmed cell death, apoptosis, which usually prevents runaway cell growth. When apoptosis fails normal cells can become cancerous.

The researchers explain that they have also found the complex chemical signalling pathways in the cell that are influenced by leptin, which reinforces their claim that leptin does indeed play a critical part in influencing cancer cell growth in the colon.

The results are published in detail in the journal BJS.

Two for tea

Two tea time stories in the news today. The first reports on a very small study showing that adding milk to tea negates the cardiovascular health benefits because it interferes with nitric oxide (NO), the natural vasodilation controller (You’ll know it from my article on Viagra. The second news item is about the antibacterial effects of green tea (it doesn’t say whether adding milk negates those benefits, but I cannot imagine drinking green tea with milk anyway.)

New York Smells

Today, the New York City authorities were investigating a persistent smell of “gas” across a large part of the lower Manhattan area of the city.

Hundreds of people reported the odd, but apparently not noxious smell, to the New York Police Department, but at the time of writing the identity of the gas remained unknown. Despite this, Mayor Michael Bloomberg somehow manages to make confident proclamations that the gas is “not dangerous”.

Over on Digg, a heated debate has been raging since the first news of the mystery smell was released on an unsuspecting public. Some members of the so-called online “news” community, claim to live in NYC and that there is no smell. Others muse that Howard Stern is to blame, while yet others are confused as to whether this represents a homeland security issue.

Some New Yorkers are saying the gas smells of gasoline (petrol to those of us this side of the pond), while others reckon it’s more like natural gas (methane, of course, has no odour so a very strong smelling sulfur-containing compound – mercaptan – is added in tiny amounts to give it a smell).

The BBC reported that the source was across the Hudson River in New Jersey, where officials said a natural gas leak originating in the Chelsea district of Manhattan, had occurred.

New York, new york, so good they named it twice…

Explosive Electronics

I am currently writing about the latest research from Mark Kuzyk – famed discoverer of the Kuzyk effect also known as the Kuzyk quantum gap. He and his colleagues have discovered a whole new class of compounds that could eventually revolutionize optical information processing (more on that in the January issue of Intute Spotlight). Anyway, he told me that getting a stronger and stronger optical, so-called non-linear response, from the materials he and his colleagues are devising will “require deliberate and painstaking molecular design and synthesis.”

But, there are also some even more serious obstacles than acumen in synthetic chemistry. He explained that molecules that have a large nonlinear-optical susceptibility, i.e. are perfect for the job in hand are often rather unstable too. Now, obviously that’s something that you have to avoid if you’re going to incorporate a molecule into a device (ask Richard Friend who has spent the last decade and a half working with his chemist colleagues to make their plastic LEDs not only bright and useful but as long-lived as possible).

All compounds are created with an intrinsic stability but some are created more unstable than others. Kuyzk told me that he had once suggested to a chemist colleague when he was at Bell Labs in the 1980s that he should try and make a specific molecule the structure of which should have produced a large optical response. “He laughed when he saw the structure,” Kuyzk said, “claiming that it would be much more explosive than TNT.” Now, I wouldn’t have liked to have been the project student charged with synthesising that nonlinear optical compound without some understanding of the stability, or otherwise, of conjugated organic bonding systems.

On a related matter, photo-stability (as opposed to thermal stability), Kuzyk also revealed to me that several years ago, a student in his group, Brent Howell, serendipitously stumbled upon a dye-doped polymer system that not only acted as a laser but recovered from photo-degradation if the system was left in the dark for a couple of days.

Furthermore, the material could be hardened to photodegradation by cycling through degradation and recovery. “We have proposed a model of the mechanisms, and are still doing experiments to test our hypothesis,” Kuyzk adds. A paper that shows recovery in two-photon absorbing materials appears in Optics Letters.

UK PubMed Central

A UK version of the free biomedical research server PubMed Central will provide free access to a permanent online archive of peer-reviewed research papers in medicine and the life sciences.

UK research funders, led by the Wellcome Trust, awarded the contract to develop UKPMC to a partnership between the British Library, The University of Manchester and the European Bioinformatics Institute (EMBL-EBI).

Members of this group now require that articles describing the results of research they support are made available in UKPMC with the aim of maximising its impact. The UKPMC service will ensure that articles resulting from research paid for by any member of the funding consortium will be freely available, fully searchable and extensively linked to other online resources.

The UKPMC essentially mirrors the US PubMed Central database but as of 8th January 2007, UK scientists will also be able to submit their research outputs for inclusion in UKPMC.

Mark Walport, Director of the Wellcome Trust commented: “Medical research is not complete until the results have been communicated. The development of UKPMC provides a great opportunity for this research to be made freely available, and I am very pleased that a first class partnership of the British Library, the University of Manchester, and the European Bioinformatics Institute will be running it.”

The British Library will run the service, promote it to researchers, as well as offering support for those who want to include their research papers in UKPMC. The University of Manchester hosts the service — on servers based at MIMAS (Manchester Information and Associated Services) — and will support the process of engaging with higher-education users. EBI, which is part of the European Molecular Biology Laboratory (EMBL), will contribute its biomedical domain knowledge and state-of-the-art text-mining tools to integrate the research literature with the underlying bioinformatics databases.

The launch of UKPMC brings into sharp relief once again the ethical debate surrounding scholarly publication. The Wellcome Trust has insisted that authors publish research arising from its funding in open access repositories since 1st October 2006.

Writing in PLoS Biology in 2005, Robert Terry (Senior Policy Adviser at the Wellcome Trust, Cambridge, United Kingdom), discussing the plans for UKPMC at the time said, “For a funder, having all its research in one format, ‘under one roof’, and searchable will improve the efficiency of strategy setting–for example, setting funding priorities–assessing the outputs of the funded research, and even gaining an insight into the impact of the work. As grants management becomes more electronic, there can be a direct link between original research proposals and the research outputs.”

According to AJ Cann on MicrobiologyBytes recently, this widely adopted funding-body policy already means “publishers are over a barrel – sign up or sign out.”

Blu-ray and HD DVD

If you’ve been worrying that either one of the high-definition video technologies – Blu-Ray or HD DVD could become the next Betamax, then worry no further. It seems that Korean company LG Electronics has come to the rescue with a dual format system that will cope with both.

It seems like an obvious idea – combine both capabilities in one machine. Why not? My DVD recorder can read and write positively and negatively and it’s not as if the new formats suffer from the differing form factor and mutually exclusivity issues as VHS tapes and Betamax tapes.

“We’ve developed the Super Multi Blue Player to end the confusion caused by the current competition between Blu-ray Disc and HD DVD. Customers are no longer forced to choose between the two formats,” explains Hee Gook Lee, president and chief technology officer of LG Electronics in a press release disseminated on January 7. “As Full HD TV is already gaining ground, we are hoping that the Super Multi Blue Player will play the trigger role in expanding and advancing both Full HD TV and high- definition DVD market volume together.”

You can read more techie details in that press release and I won’t bore you with them here, suffice to say that it’s pretty unlikely these machines will appear in the UK in the very near future, but early adopters Stateside will be able to go dual blue some time in the next couple of months.

Both high-def DVD formats were introduced in 2006 and 2007 is expected to see film studios release more of their output in these formats as more players become available. With the advent of dual-format players, the studios will not be forced to opt for an either-or scenario nor have to offer both formats in a single product package.

Knights of the chemical realm

Right royal honours were bestowed on two of my very oldest contacts in the field of chemistry this week. Royal Society of Chemistry president Professor Jim Feast was awarded the CBE in the New Year Honours List for ‘services to polymer chemistry.’ And, supramolecular ex-pat Fraser Stoddart was given a Knighthood for to ‘services to chemistry and molecular nanotechnology.’

Congratulations to them both. With such accolades under their belts, it’s surely only a matter of time before either one of them gets that phone call from Stockholm too.

Pluto is a planet

Well, no, it is, and it isn’t. It all depends on your perspective and what you feel about there being more than 20 planets in the Solar System rather than the more usually seen 9.

David Weintraub takes us on a cosmic tour through the history books from Aristotle’s logical fallacies of aether and perfect spheres moving in perfect circles to the discovery of dozens upon dozens of shapely and shapeless objects littering the once perfect heavens.

On 24th August 2006, as reported on Sciencebase (and everywhere else, admittedly), the International Astronomical Union decreed that Pluto should be demoted to the status of dwarf planet. After all, it’s discovery was a pure accident, it shouldn’t really have been spotted where it was in the 1930s at all, and it’s just so small, and really just the biggest of what we now refer to as the Kuiper Belt Objects.

However, there is no scientific reason to label Pluto as “not a planet”.

In one sense, Weintraub’s argument hinges on the fact that we cannot define what is and what is not a planet on the basis of a mnemonic taught to science students – My Very Earthly Mother Just Served Us Nasty Pizza.

Space is far more messy than that. Between Mars and Jupiter, where earlier astronomers hoped to find a planet that fit the now debunked Titius-Bode rule (which never quite became law), we find some startlingly large asteroids instead, among them Ceres. Then there is Eris (formerly known as UB313 and colloquially as Xena), and a myriad swarm of Kuiper belt objects, trans-Neptunian object, Oort cloud objects…

The list goes on. But, in the final reckoning is it for us to draw lines and say such and such an icy rock whirling around the sun billions of miles from earth is any more planet than the next chunk of ice and rock.

Pluto looks like a planet, moves like a planet, and quacks like a planet. Obviously that last one isn’t quite right. But, it’s not a planet like the inner planets, it’s not a gas giant, and it’s not like an asteroid, which would have been much more appropriately named planetoids rather than being labelled literally as “star-like”.

Weintraub anticipates that there will be no problem for the young, upcoming astronomers to simply add qualifiers to all the different kinds of planet we find. Nothing will be less alien than terms such as giant, terrestrial, icy, pulsar, belt-embedded prefixing the word planet and allowing is to create a sophisticated taxonomy that allows us to understand the nature of the universe around us.

It will make for an unwieldy mnemonic with our Earthly Mother having to add all kinds of toppings to that Nasty Pizza to make it stick. But then planets are intrinsically unwieldy.

RFID for chemicals

RFID for moleculesA new type of radio frequency identification (RFID) sensor for gaseous molecules has been created based on a standard RFID tag coated with a chemically sensitive film at low cost. The use of multivariate analysis allows these new RFID sensors to be used to identify and quantify vapours important to industrial, in health, law enforcement, and of security applications.

Radislav Potyrailo and William Morris of the Materials Analysis and Chemical Sciences Technology at General Electric Global Research Center, in Niskayuna, New York, explain the benefits of their new technology in a forthcoming issue of the journal Analytical Chemistry. “Distributed sensor networks are critical for numerous applications such as monitoring of transport of pollution plumes across the perimeters of industrial plants, leak detection from storage tanks, health monitoring of buildings, large-area tracking of contamination sources in natural water supplies, and spatially resolved combinatorial screening of materials,” they explain.

More…