Saturday, November 29, 2008

e-mail !##/@!

Science Daily (Nov. 28, 2008)

Expressing Emotions In E-mail So As Not To Be Misinterpreted

Daniel A. Menchik and Xiaoli Tian (both of the University of Chicago) studied how we use emoticons, subject lines, and signatures to define how we want to be interpreted in email. The authors find that "a shift to email interaction requires a new set of interactional skills to be developed."

Unlike face-to-face conversations, email interactions leave out tone of voice, body-language and context, which can lead to misunderstandings. While these authors agree that there are difficulties, they believe that no way of communicating is actually superior to another.

Menchik and Tian argue that face-to-face and internet-based contexts each require a set of distinct interaction strategies. "People can cultivate ways of communicating in online contexts that are equally as effective as those used offline," they write. "The degree to which … individuals develop unique conventions in the medium will determine their ability to communicate effectively."

The research focuses on "the case of a well-known scientific organization that decided to replace occasional meetings of a research panel with ongoing email interaction." The panel encountered numerous problems conversing via email. But the researchers identified several ways people were able to overcome these barriers.

"People innovate in response to the challenges of a new context for the communication of essential elements of language," the authors write.

Capital letters, use of quotations, emoticons, exclamation points, punctuation, bullet points, style and even color help the sender communicate the meaning of a word or message. For example, "I feel betrayed" reads differently from "I FEEL SO BETRAYED!! ;)" where the capital letters and winking smiley face indicate sarcasm.

Participants also maintained their conversational flow by cutting and pasting from previous emails and using subject lines that referenced previous discussions. In email listservs these devices help address comments to a certain individual and help the discussion to stay on topic.

Signatures, disclaimers and other information about the person's state of mind were also commonly used when writing an email. The authors found that subjects felt more comfortable communicating once they knew a little about each other, like the information included in a signature. They also found that indicating the frame of mind as a disclaimer, (i.e. "I wrote this at 5AM" or "on a blackberry while on vacation") helped prevent the email from being misinterpreted.

Developers have picked up on these cues with the advent of linguistic monitors such as Eudora's MoodWatch feature. This program tries to indicate to the sender that their email might be considered inflammatory, and to the receiver that they are about to receive such an email.

reference

Putting Social Context into Text: The Semiotics of E-mail Interaction
Daniel A. Menchik and Xiaoli Tian
American Journal of Sociology
Volume 114 Number 2 (September 2008): 332–70
Link to AJS abstract

Link to Science Daily article

Don't blame television

Science Daily (November 26, 2008)

Television: Not the Only Channel to Early Sex

Watching plenty of television combined with low self-esteem, poor relationships with parents, and low academic achievement are some of the factors that may add up to young people having sex before the age of 15. Alternatively, a parent's positive influence may go a long way to reduce risky sexual behavior during adolescence, according to Myeshia Price and Dr. Janet Hyde from the University of Wisconsin.

Adolescents who engage in sexual acts before the age of 15 are likely to do so without adequate protection, putting them at higher risk of sexually transmitted infections and, for girls, unwanted pregnancies. In 2006, the Centers for Disease Control and Prevention found that 750,000 pregnancies and almost half of new cases of sexually transmitted infections were among adolescents.

To help identify ways to reduce the number of adolescents who have sex before the age of 15, Price and Hyde examined a combination of individual, family, and sociocultural factors thought to predict early sexual activity. A total of 273 adolescents (146 girls and 127 boys) took part in the Wisconsin Study of Families and Work and were studied between the ages of 13 and 15. They were asked about their sexual behavior, puberty, academic achievement, self-esteem, depression, sports participation, symptoms of attention-deficit hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD), family structure and quality of relationships with parents, and exposure to sexuality through the media.

Of the 273 adolescents studied, 15 percent had experienced early sex - intercourse and/or oral sex. Girls who had been sexually active before the age of 15 spent more time watching television, had lower self-esteem, had poor relationships with their parents, had lived with either a single mother or step-parent, showed signs of ADHD, and underachieved at school. Those boys who had engaged in early sexual activity were further into their puberty, spent more time watching television, had lower self-esteem, showed signs of ADHD and ODD, and had poor relationships with their parents.

One factor had a particularly large effect: the amount of time spent watching television. Across all risk factors, the more factors pushing young people to have sex early, the more likely they were to do so. For example, compared to an adolescent with zero risks, someone with three of the above influences (the average for the studied sample) was five times more likely to have had sex by the age of 15. These findings strongly suggest that intervention programs aimed at reducing the number of adolescents who have sex at a younger age are more likely to be effective if they target a combination of factors.

This study also shows that parents influence adolescents' decision to engage, or not, in early sexual activity. The authors recommend that "preventive measures should not be left up to teachers and counselors alone, but might include parents." They add that "positive influence from parents, coupled with comprehensive education programs, have the potential to have an unsurpassed effect on early adolescent sexual activity."

reference:

When Two Isn’t Better Than One: Predictors of Early Sexual Activity in Adolescence Using a Cumulative Risk Model.
Myeshia N. Price and Janet Shibley Hyde
Journal of Youth and Adolescence, 2008; DOI: 10.1007/s10964-008-9351-2
Link to JYA abstract

Link to Science Daily article

HIV diagnoses in Europe doubled

Roger Pebody for Aidsmap (November 28, 2008)

HIV diagnoses in European MSM have almost doubled since 2000, UK tops the list

Data from 23 European countries show that the annual number of HIV diagnoses in men who have sex with men (MSM) has increased by 86% between 2000 and 2006, report epidemiologists in the November 2008 issue of Sexually Transmitted Infections. The United Kingdom is the country with the highest number of new diagnoses in Europe, but dramatic increases were also seen in low prevalence countries in Central and Eastern Europe.

Giedrius Likatavicius and colleagues from the EuroHIV programme analyzed data on new HIV diagnoses in men who have sex with men from 30 European countries (the member states of the European Union, plus Switzerland, Iceland and Norway).

For the year 2006, a total of 7,693 new diagnoses in MSM were reported in the 27 European countries which had data available (excluding Spain, Italy and Estonia). That equates to 57 cases per million adult men in the population (57/million).

However the 2,597 diagnoses in the United Kingdom that year made it the country with the largest number of new cases in Europe and also the country with the highest rate of new diagnoses among MSM per million male adults (130/million). The rate was also above 100 cases per million men in the Netherlands and Luxembourg, and above 75 cases per million men in Switzerland and Portugal.

For the comparison of 2000 and 2006, data were available for 23 countries. The other countries could not provide data for each year, or had changed their surveillance system during the period. The Netherlands, France and Spain are among the countries excluded from the analysis for these reasons.

There was an overall increase of 86% in the number of new diagnoses between 2000 and 2006. Only four countries reported a decrease (Cyprus, Iceland, Lithuania and Luxembourg).

Cases increased by 91% in the UK, and the number of annual diagnoses more than doubled in several countries, including Finland, Germany and Norway.

Despite having a comparatively low prevalence, rates also doubled in Hungary (118% increase) and tripled in Slovenia (257% increase). The authors draw attention to sexual mobility and high levels of reported risk behavior in such countries, which they say leaves open the potential for the rapid spread of HIV there.

More encouragingly, in all but one of the 18 countries which had data on late diagnosis, the proportion of cases diagnosed late had decreased. In 2000, 25% of men were diagnosed late, but by 2006 this was down to 10%.

The authors point to studies demonstrating continued risk behavior. Indeed, this week also saw the release of new data which identifies increases in risky sexual behavior among MSM in Denmark.

The annual Sex Life Survey has been run in 2000, 2001, 2002 and 2006, with over 3,000 men participating in the most recent survey. The researchers report several increases in risk behavior, each of which is statistically significant:

In the three previous surveys, between 26% and 28% of men reported unprotected anal sex that was not known to be with a man of the same HIV status. In 2006, 33% of men reported this behavior.

Previously, between 84% and 86% of men reported any anal sex. In 2006, this rose to 92%.

The average number of anal sex partners increased from 8 to 9.4.

The proportion of men with one steady partner dropped from 26% to 20%, while the numbers who only had casual partners rose from 28% to 34%. The proportion of men with both steady and casual partners rose from 29% to 35%.


Returning to the European surveillance report, its authors conclude: “We have reported a recent increase in the number of HIV diagnoses among MSM in nearly all EU and EFTA countries, and in some countries this probably represents a true increase in incidence. This, combined with the high prevalence of HIV reported in many gay community settings, the high prevalence of HIV among MSM diagnosed with STI and the high sexual mobility of this population, highlight the need for a Europe-wide HIV prevention strategy.”

Reference


An increase in newly diagnosed HIV cases reported among men who have sex with men in Europe, 2000–6: implications for a European public health strategy.
G Likatavicius et al
.

Sexually Transmitted Infections 200884: 499-505. doi:10.1136/sti.2008.031419.
Link to STI abstract

HIV and risk behaviour among men who have sex with men in Denmark - the 2006 Sex Life Survey.
S A Cowan & J Haff
Eurosurveillance Volume 13, Issue 48, 27 November 2008.

Links to Eurosurveillance abstract

Link to Aidsmap article

Slowing the virus


Science Daily (November 28, 2008)

Selenium May Slow March Of AIDS

Increasing the production of naturally occurring proteins that contain selenium in human blood cells slows down multiplication of the AIDS virus, according to biochemists.

"We have found that increasing the expression of proteins that contain selenium negatively affects the replication of HIV," said K. Sandeep Prabhu, Penn State assistant professor of immunology and molecular toxicology. "Our results suggest a reduction in viral replication by at least 10-fold."

Selenium is a micronutrient that the body needs to maintain normal metabolism. Unlike other nutrients, which bind to certain proteins and modulate the protein's activity, selenium gets incorporated into proteins in the form of an amino acid called selenocysteine.

These proteins – selenoproteins – are especially important in reducing the stress caused by an infection, thereby slowing its spread.

Upon infecting a person, the virus quickly degrades selenoproteins so that it can replicate efficiently. It is unclear just how the virus is able to silence these proteins but Prabhu and his colleagues believe that stress inflicted on cells by the rapidly dividing virus, which produces a key protein known as Tat, is the likely culprit.

Tat is one of about 14 odd proteins produced by HIV during the first stage of infection. The job of these proteins is to trigger the expression of all the other genes that the virus needs to sustain itself. In addition, Tat also plays a key role in helping the virus replicate.

One of the proteins that targets Tat is a selenoprotein known as TR1.

"Since HIV targets the selenoproteins, we thought that the logical way to deal with the virus is to increase the expression of such proteins in the body," explained Prabhu, whose team's findings are outlined this week (Nov. 28) in the Journal of Biological Chemistry.

Researchers first isolated blood cells from healthy human volunteers who did not have HIV, and infected those cells with the virus. Next, they added tiny amounts of a selenium compound – sodium selenite – into the cell culture to see the effect on viral replication.

Results from the tests indicate that the addition of selenium inhibits the replication of HIV at least 10-fold, compared to cell cultures in which no selenium is added. When the researchers selectively reduced production of the selenium containing TR1 protein, they observed a 3.5-fold increase in viral replication.

"This confirms that while increasing the expression of TR1 has a negative impact on the replication of HIV, reducing it helps the virus replicate more efficiently," explained Prabhu. He believes that TR1 works by upsetting the chemical structure of Tat, which in turn reduces the virus' ability to replicate.

Reference:

Thioredoxin Reductase-1 Negatively Regulates HIV-1 Transactivating Protein Tat-dependent Transcription in Human Macrophages
Parisa Kalantari
et al
Journal of Biological Chemistry Vol. 283, Issue 48, 33183-33190, November 28, 2008

Link to JBC abstract

Link to Science Daily article

Friday, November 28, 2008

over 50’s risky sex


Michael Carter for Aidsmap (November 27, 2008)

Older HIV-positive gay men as likely to have risky sex as younger gay men with HIV

A significant number of people living with HIV in London are aged over 50, researchers report in the December edition of Sexually Transmitted Infections. Another finding of the study was that the proportion of gay men aged 50-plus reporting unprotected sex with men who were HIV-negative or whose HIV status they did not know, was similar to that reported by younger gay men.

The number of people living with HIV in the UK has doubled since effective HIV treatment became available. There are two reasons for this: patients are living significantly longer thanks to antiretroviral therapy, and there are new HIV diagnoses.

A “graying” of the HIV epidemic in the US has been reported, but there has hitherto been little research on the ageing of the HIV-positive population in the UK.

Researchers therefore designed a study looking at the age of diagnosis, sexual behavior and some social characteristics of people living with HIV who were aged over 50, focusing their attention on gay men.

There were no significant differences in sexual behavior between older and younger gay men. The researchers found gay men in their 50s just as likely as gay men in other age groups to report unprotected anal sex with a gay men who was HIV-negative or of unknown HIV status.

Furthermore, gay men in their 50s reported that they had had unprotected anal sex with an average of four men who were HIV-negative or of unknown HIV status in the previous three months. This was no different to the number reported by gay men in other age groups.

The investigators think that these findings show the importance of targeting HIV prevention messages at older as well as younger HIV-positive gay men.

Older gay men were, however, less likely to report “serosorting” (the selection of other HIV-positive partners) than gay men aged under 50.


“Our study highlights the diversity of older people living with HIV”, write the investigators, “the over 50s with HIV do not simply comprise an ageing cohort of people diagnosed in their 30s and 40s, but also people diagnosed with HIV over the age of 50 years.”

They conclude, “this diversity will present a continuing challenge for HIV treatment and prevention among older people living with HIV in the UK. Positive prevention programs should target HIV-positive gay men of all ages because older gay men with HIV were just as likely to report high-risk sexual behavior as younger gay men.”

Reference

Over fifty and living with HIV in London.
Elford, J. et al.
Sexually Transmitted Infections 84: 468-72, 2008.

Link to STI abstract

Link to Aidsmap article

New Vaccine trials

Science Daily (November 27, 2008)

Phase I Clinical Trial To Test Combination Of Two HIV Vaccine Candidates Starts In London

The International AIDS Vaccine Initiative (IAVI) and the St. Stephen’s AIDS Trust at the Chelsea and Westminster Hospital have initiated a Phase I clinical trial in London, UK to test a prime-boost combination of two HIV vaccine candidates.

“Prevention is crucial in the fight against HIV and AIDS, and a vaccine is one of the most powerful prevention tools we know to combat infectious diseases,” said Professor Brian Gazzard, Research Director at the St. Stephen’s AIDS Trust and the principle investigator of this trial. “We hope this trial will contribute to a better understanding of how to induce with a vaccine an immune response to protect against HIV infection and AIDS.”

The news follows promising results recently announced by IAVI and partners for one of the two vaccine candidates to be tested, the MVA-based TBC-M4, which in a recent phase I trial generated modest immune responses in all volunteers who received the highest dose. According to Patricia Fast, Chief Medical Officer at the International AIDS Vaccine Initiative, “The responses observed with this vaccine candidate warrant further research to improve immune activation. We have learned from other studies that a prime-boost regimen has the potential to achieve just this.”

That is why the new trial will include a DNA-based vaccine candidate called ADVAX to prime the immune system. Previous Phase I studies with different DNA and MVA-based HIV vaccines in combination have shown that this prime-boost regimen was safe and well tolerated, and also able to generate enhanced immune responses when compared with the responses generated by either vaccine alone. The ADVAX vaccine candidate also offers economic value; it is relatively easy and cheap to manufacture, which makes it particularly appealing for use in the developing world.

A separate Phase I trial testing ADVAX and the MVA-based candidates in a prime-boost regime is planned for India. This trial would use a different mode of administration for the priming vaccine, different dosages and different vaccine regimens. Collectively, the results of both trials will help determine whether further development of both AIDS vaccine candidates in a prime-boost combination is warranted.

Link to Science Daily article

PrEP

Clare Wilson for New Scientist (November 22 -28. 2008)

Safer sex in a pill

As a gay man living in the US, John has seen every kind of AIDS awareness campaign out there. He is intelligent and well informed, yet sometimes he has unsafe sex. He never plans to, but he does not always have a condom handy and occasionally, on the spur of the moment, decides not to use one.

Such behavior is not that unusual among gay men, but unlike most, John (not his real name) isn't leaving himself totally exposed. That is because his doctor is willing to do something most would not countenance - prescribe John a medicine that could lower his risk of catching HIV.

This strategy is called pre-exposure prophylaxis, or PrEP, and John gets it from Marcus Conant, a doctor with a long history of standing up for gay rights. PrEP has yet to be proven in clinical trials, and Conant will only prescribe it for a select group of his patients - those who understand the limitations of this tactic. But if the most optimistic predictions are borne out, by taking a pill once a day John is radically reducing his risk of infection even if he has condom-free sex with as many people as he likes. It is more likely that the medicine has a modest effect - perhaps reducing the risk by around two-thirds - but even so, it significantly improves John's odds in the dicey game he plays.

For now PrEP is only available to a select few, but that looks set to change very soon. PrEP is being tested in several large trials, with the first results due next year. If it works, PrEP could save millions of lives from the epidemic that is still raging around the world, infecting an estimated 7000 people every day.

While it sounds like good news, PrEP is not without its critics. The main fear is that it will lull people into a false sense of security, encouraging them to have more unsafe sex and so, paradoxically, spreading the virus further and faster. There is also a looming firestorm over a drug that apparently gives people license to have unprotected sex or inject themselves with illegal drugs.

Wilson goes on to explore the impact of the slow progress in finding a vaccine.

She points out that PrEP involves drugs already used as a treatment for HIV, known as highly active antiretroviral therapy, or HAART. These drugs have shelf-loads of safety data to back them up and could be ready to use as PrEP long before any vaccine or microbicide goes on sale.

PrEP has its roots in an existing strategy called post-exposure prophylaxis (PEP), in which people who have come into accidental contact with HIV are given antivirals afterwards.

Early antivirals had nasty side effects and involved taking large numbers of pills in complex combinations, so they were not appealing for use as PrEP. But in the past few years more user-friendly drugs with fewer side effects have been developed, making PrEP possible. One such drug, tenofovir, is just a single daily pill. The other is a two-in-one daily pill called Truvada, which contains tenofovir plus a drug called emtricitabine.

Several large trials designed to answer the question of effectiveness are ongoing. They involve a total of 19,000 people at high risk - including gay men, injecting drug users and sexually active women in HIV hot spots - in various parts of the world The first results on tenofovir should be out next year, with data on Truvada expected in 2010.

Conant, who has perhaps more experience than anyone of seeing PrEP in the real world, accepts that some of his patients probably do have more unsafe sex as a result. "I'm fairly certain that some engage in more high-risk behavior because they have got access to the drugs," he says. "But that's not true of all the patients."

However, such "behavioral disinhibition" did not seem to happen in the African trial, perhaps because the participants also received free condoms and advice on safe sex. Bob Grant, who researches HIV prevention at the University of California, San Francisco, and helped run the African trial, speculates that some users may even have less unsafe sex. "PrEP might put people in a different frame of mind," he says. "When people take a pill a day, that reminds them that they are at risk of catching HIV."

Another concern is drug resistance. HIV easily evolves immunity to antiviral drugs, which is why people on HAART take three different ones simultaneously: the probability of the virus acquiring resistance to all three at once is vanishingly small.

The fear with PrEP is that some users will be HIV positive without knowing it, and because PrEP only involves one or two drugs their virus will evolve resistance. These people then become a potential source of infection for others on PrEP. The drugs are also lost to them as a treatment, as well as to anyone that they subsequently infect.

Resistance is less common for tenofovir and Truvada than for many of the other antiviral drugs, but it does occur. One solution would be to insist that people on PrEP are regularly tested for HIV, though this would raise the cost.

Wilson makes the point, not only does PrEP raise scientific questions, it also opens a political debate. It is almost certain that some people will find PrEP morally objectionable and that there will be acrimonious debates over who should pay for it.

There is also the issue of cost in poorer countries. Many manufacturers now sell antivirals in these countries at cost price - about $1 a day in the case of Truvada. Even so, the drugs only get to about a third of those who need them. Against this background, providing PrEP to everyone at risk from HIV in the developing world seems a fantasy.

Link to the Conant Foundation

Link to the New Scientist article


Accompanying the article (in the same edition - New Scientist November 22 -28. 2008) is a summary of the problems with an HIV vaccine

The trouble with vaccines

Why has the search for an HIV vaccine hit so many dead ends?

Vaccines against other viral infections use viruses that have been either weakened or killed to trigger an immune response without causing disease. This approach is acceptable for most diseases but is seen as too risky with HIV, as a weakened virus could mutate and become lethal again.

The first attempts to create an HIV vaccine involved isolating the main molecule on the virus surface, called gp120, and injecting it. As expected, people given gp120 made antibodies to the virus, but unfortunately these were not potent enough to prevent infection. Researchers have not given up on the antibody approach, but it is probably at least 10 years away from producing results.

"There are no really good candidates at this point," says Dennis Burton, an immunologist at Scripps Research Institute in La Jolla, California. In the meantime, most vaccine researchers have turned their attention to a different branch of the immune system: the T-cells. While antibodies destroy free-floating viruses, T-cells kill other cells that are infected with virus. This approach was inspired by the discovery of a few rare individuals whose T-cells apparently made them immune to HIV.T-cell vaccines involve injecting HIV genes into the bloodstream. The genes are taken up by cells and used to make HIV proteins. T-cells recognize the proteins as foreign and learn to attack cells infected with HIV itself.

There are more than a dozen T-cell vaccines in development involving various mixes of HIV genes, but confidence in this approach took a big knock in late 2007 after the first large-scale trial ended in failure The trial, called STEP, tested a vaccine made by drug company Merck. It comprised a weakened cold virus carrying three HIV genes. For reasons still unknown, the vaccine not only failed to protect against HIV but actually doubled the infection risk in men who already had some immunity to the cold virus.

Vaccine researchers are now reassessing the whole T-cell approach, and a planned trial of a US National Institutes of Health (NIH) vaccine very similar to the Merck one was cancelled in July this year. The failure of the STEP trial could even make it harder to run trials of any kind of HIV vaccine in future, as volunteers will have to be told that the Merck vaccine raised the risk of infection for some people. "The warning will be ramped up," says Margaret Johnston, head of HIV vaccine research at the NIH.
It is not exactly a selling point.

Link to New Scientist article

Woolies gone?


The Times reports that UK Woolworths stores will close after Christmas. The High street retail chain, which opened its first British shop almost 100 years ago’ has debts of £385 million

Its 800 outlets will open as usual, but many are expected to shut for good after Christmas, despite government intervention to save the jobs of almost 30,000 people who work for Woolworths.


Peter Brookes - The Times

Wednesday, November 26, 2008

Torture Pardons

Countdown: John Dean on Torture Prosecutions

Rachel Maddow Show: Turley on Torture Prosecutions

Bad Sex honored

A friend sent us this article by James Pressley from Bloomberg News (November 25, 2008)

Bad Sex in Fiction Awards Go to John Updike, Rachel Johnson

John Updike’s sex scenes -- including a romp with a “Widows of Eastwick” witch in a beachside motel room -- won a Lifetime Achievement Award at Britain’s ever- anxiously awaited Bad Sex in Fiction Awards.

Rachel Johnson, the sister of London Mayor Boris Johnson, captured the 16th annual Bad Sex Award itself for a scene in “Shire Hell” that begins with moans and nibbles and works up to screaming and other animal noises.

The contest seeks to dishonor the author of the year’s worst sex scene. London’s monthly Literary Review inaugurated the prize in 1993 “to draw attention to the crude, tasteless, often perfunctory use of redundant passages of sexual description in the modern novel, and to discourage it.”

The judges cited Updike for his “unique achievement” after his latest novel, “The Widows of Eastwick,” garnered a fourth consecutive nomination for the prize.

“Good Sex or Bad Sex, he has kept us entertained for many years,” the judges said in a statement, quoting from a passage so redolent in lips, rubbing and “deep throbs” that we blush to reproduce it here.

Link to Bloomberg article

whizz out

BBC News on line (November 25, 2006)

Men guilty over fake penis scam

The makers of a prosthetic penis to help men cheat on drugs tests have pleaded guilty to two charges of conspiracy in a US federal court in Pittsburgh. They could face up to eight years in prison and a $500,000 fine when they are sentenced in February.

The two men, George Wills and Robert Catalano, had been selling the device - known as the Whizzinator - over the internet for three years.
The device was sold with a heating element and fake urine to help people test negative for illegal substances.

The men ran an internet company known as Puck Technology, which between 2005 and 2008 sold the Whizzinator and a similar device, known as Number One.

"The Whizzinator is the ultimate solution for a drug testing device," says a statement on the website of the California-based company, which calls itself the "undisputed leader in synthetic urine."
"The prosthetic penis is very realistic and concealing is simple, while our quality production and materials assures you that the Whizzinator will let it flow again and again, anytime, anywhere you need it!"

Link to BBC news report


Sperm size

Science Daily (November 26, 2008)

Sperm Size Isn't Everything

— Contrary to common scientific belief, the length of a sperm's tail does not always determine how fast it can swim. Research published in the open access journal BMC Evolutionary Biology has shown that in the counter-intuitive microscopic world in which sperm operate, streamlining and longer tails don't always provide a speed advantage.

Stuart Humphries, from the University of Sheffield, and collaborators from the University of Western Australia have critically evaluated the evidence linking sperm shape to swimming speed. He said, "It seems clear that some assumptions regarding the physics of sperm locomotion have hampered our progress in understanding the processes mediating sperm competition. It is commonly believed that selection for increased sperm performance will favor the evolution of longer, and therefore faster swimming, sperm. In fact, the relative lengths of a sperm's constituent parts, rather than their absolute lengths, are likely to be the target of selection."

Small size and low swimming speeds mean that, in hydrodynamic terms, sperm operate in a very different regime from the one that we are used to. At this microscopic scale, although a longer tail does allow a sperm to generate more thrust, the drag created by a sperm's head is often enough to counteract any such gains.

According to Humphries, "We suggest that, irrespective of whether tail length, total length or head length is used, any attempts to correlate a single measure of length to speed are likely to be futile. We argue that accounting for the balance between drag from the head and thrust from the tail will allow us to extend our understanding of the link between sperm form and function."

These findings imply that, contrary to current thinking, one cannot attribute the evolution of longer sperm to any competitive advantage that length alone gives them.

reference:

Sperm competition: linking form to function.
Stuart Humphries et al
BMC Evolutionary Biology 2008, 8:319doi:10.1186/1471-2148-8-published 25 November 2008

Link to BMB Evol. Biology abstract

Link to Science Daily article

'slash Aids'?

Imogen Foulkes for BBC News, Geneva (November 26, 2008)

Universal test 'would slash Aids'

Universal testing for HIV, followed by immediate treatment could cut the number of people developing full-blown Aids by up to 95%, and "could virtually end the AIDS epidemic in Africa in about a decade," according to a mathematical model published in The Lancet .
For the study, Charlie Gilks, an AIDS treatment expert at the World Health Organization, and colleagues, used data from South Africa and Malawi.

It is suggested that this strategy could virtually eliminate HIV transmission.

The study used computer modeling to project what would happen if everyone over 15 was tested every year. But the WHO said that weak health care systems meant that universal testing was not a realistic idea. It adds that giving treatment to patients who are not yet sick may increase drug resistance, while the side effects of taking Aids treatment drugs for very long periods are as yet unknown but could be severe.

At first sight, the results of the WHO study are a clear argument for universal HIV testing - it could become a run-of-the-mill medical check like those for high blood pressure or cholesterol.

Diagnosis and immediate treatment with anti-retroviral drugs could, researchers say, reduce cases of Aids in a generalized epidemic from 20 in 1,000 people to just one in 1,000 within 10 years.

At the moment HIV testing and treatment are patchy, and while around three million people are receiving anti-retrovirals, a further 6.7 million need them.

Writing in a commentary piece in The Lancet, Dr Geoffrey Garnett, from Imperial College London, said: "At its best, the strategy would prevent morbidity and mortality for the population, both through better treatment of the individual and reduced spread of HIV.
"At its worst, the strategy will involve over-testing, over-treatment, side effects, resistance, and potentially reduced autonomy of the individual in their choices of care."

Universal voluntary HIV testing with immediate antiretroviral therapy as a strategy for elimination of HIV transmission: a mathematical model
Reuben M Granich MD et al
The Lancet, Early Online Publication, 26 November 2008
doi:10.1016/S0140-6736(08)61697-9

Link to The Lancet abstract

Link to BBC News report

Bloomberg News also covers the study in more detail

Link to Bloomberg news article


Tuesday, November 25, 2008

‘not financially secure’

Science Daily (November 24, 2008)

76 Percent Of American Middle-class Households Not Financially Secure

As the economy continues to reel, a new report finds that 4 million American households lost economic security between 2000 and 2006, and that a majority of America's middle class households are either borderline or at high risk of falling out of the middle class altogether.

The new report, "From Middle to Shaky Ground: The Economic Decline of America's Middle Class, 2000-2006" was published by the policy center Demos and the Institute for Assets and Social Policy (IASP) at Brandeis University.

From Middle to Shaky Ground shows some worrying trends in America's households, including:

  • The median financial assets held by middle-class families declined by 22 percent. This means that for every dollar in median assets that middle-class families held in 2000, they held just 78 cents in 2006. These figures do not include home equity and therefore do not reflect additional losses families may have experienced due a decline in their home values.
  • Monthly housing expenses for the middle class rose by 9 percent. As a result, the percentage of middle-class families who match the Department of Housing and Urban Development's definition of "housing burdened" rose from 31 percent in 2000 to 37 percent in 2006.
  • The number of middle-class families in which at least one member lacks health insurance grew from 18 percent in 2000 to 25 percent in 2006.

"Declines such as these in any one area are alarming," said Tom Shapiro, Professor of Law and Director of the Institute on Assets and Social Policy at Brandeis. "Bad news across a range of areas supporting financial stability means the middle class is confronting its greatest challenge since the Great Depression."

This is the third report in a series based on the Middle Class Security Index. The first examined the overall economic security of the middle class, the second focused on African-American and Latino households.

Link to Demos site.

Link to Science Daily article

Teen Smoking – Dad?


Science Daily (November 24, 2008)

Smoking, Teens And Their Parents: New Research

A new study found that adolescents were at the greatest risk of smoking when their parents began smoking at an early age and the parents' smoking quickly reached high levels and persisted over time.

The study draws from the long-running Indiana University Smoking Survey and builds on previous research that suggests smoking behavior is influenced by both genetics and the environment.

"This particular study focuses more on the genetic influence in the specific case of a parent's smoking behavior impacting a teenage son or daughter's smoking," said Jon Macy, project director of the IU Smoking Survey in the Department of Psychological and Brain Sciences. "The study findings suggest that the characteristics of early onset and high levels of long-term smoking are great candidates for behavioral and molecular genetic studies of the causes of smoking and how smoking behavior is passed from one generation to the next.

Previous studies, many of which relied on parents' current smoking status only, offered mixed results about whether parental smoking is predictive of adolescent smoking. The current study, however, used longitudinal data to identify more detailed information about parental smoking behaviors such as amount of smoking, speed of escalation, peak of use and persistence over time.

The IU Smoking Survey, a 28-year longitudinal study of the natural history of cigarette smoking, is the longest running study of its kind. Researchers began collecting data in 1980 from middle and high school students in Monroe County, Ind. Researchers continue to collect data from participants and have now started surveying their children.

"This study used a more informative description of parental smoking behaviors," Macy said. "We've found that these descriptions might do a better job than current parental smoking status of predicting risk of their adolescent children starting to smoke."

reference:

Multiple Trajectories of Cigarette Smoking and the Intergenerational Transmission of Smoking: A multigenerational, longitudinal study of a Midwestern community sample.
Laurie Chassin et al
Health Psychology
Vol. 27, No. 6, 819–828 November 2008
Link to the Study report

link to Science Daily article

New Ebola Virus


Science Daily (November 24, 2008)

New Species of Ebola Virus Discovered

Scientists report the discovery of a new species of Ebola virus, provisionally named Bundibugyo ebolavirus. The virus, which was responsible for a hemorrhagic fever outbreak in western Uganda in 2007, has been characterized by a team of researchers from the Centers for Disease Control and Prevention in Atlanta, Georgia the Uganda Virus Research Institute; the Uganda Ministry of Health; and Columbia University.

Ebola virus infection in humans causes severe disease for which there is presently no vaccine or other treatment. Case fatalities range historically between 53 and 90%. Therefore, research efforts into the Ebola virus genus and potential diagnostics are ongoing, with the discovery of Bundibugyo ebolavirus representing one of the latest pieces added to this puzzle.

The new virus is genetically distinct from all other known Ebola virus species, differing by more than 30% at the genetic level. More traditional ELISA-based assays detected the new virus; however, the unique nature of this virus created initial challenges for traditional Ebola virus molecular diagnostic assays and genome sequencing approaches.

To determine the genetic signature of this new Ebola virus species, scientists used a recently developed random-primed pyro-sequencing approach, quickly determining the genetic sequence of over 70% of the virus genome.

Knowledge of this sequence then allowed for the rapid development of a sensitive molecular detection assay which was deployed to the field as part of the outbreak response. This draft sequence also allowed for easy completion of the whole genome sequence using a traditional primer walking approach and prompt confirmation that this virus represented a new Ebola virus species.

Current worldwide efforts to design effective diagnostics, antivirals and vaccines will need to take into account the distinct nature of this new member of the Ebola virus genus.

reference:

Newly Discovered Ebola Virus Associated with Hemorrhagic Fever Outbreak in Uganda.
Jonathan S. Towner et al.
PLoS Pathogens 2008; 4(11): e1000212 DOI: 10.1371/journal.ppat.1000212

Link to PLoS Pathogens abstract

Link to Science Daily article

“cyberchondria”

John Markoff for the New York Times (November 25, 2008)

Microsoft Examines Causes of ‘Cyberchondria’

On Monday, Microsoft researchers published the results of a study of health-related Web searches on popular search engines as well as a survey of the company’s employees.

The study suggests that self-diagnosis by search engine frequently leads Web searchers to conclude the worst about what ails them.

The researchers said they had undertaken the study as part of an effort to add features to Microsoft’s search service that could make it more of an adviser and less of a blind information retrieval tool.

Although the term “cyberchondria” emerged in 2000 to refer to the practice of leaping to dire conclusions while researching health matters online, the Microsoft study is the first systematic look at the anxieties of people doing searches related to health care, Eric Horvitz said.

Mr. Horvitz, an artificial intelligence researcher at Microsoft Research, said many people treated search engines as if they could answer questions like a human expert.

“People tend to look at just the first couple results,” Mr. Horvitz said. “If they find ‘brain tumor’ or ‘A.L.S.,’ that’s their launching point.”

Mr. Horvitz is a computer scientist and has a medical degree, and his fellow investigator, Ryen W. White, is a specialist in information retrieval technology.

They found that Web searches for things like headache and chest pain were just as likely or more likely to lead people to pages describing serious conditions as benign ones, even though the serious illnesses are much more rare.

Mr. Horvitz said that in addition to his interest in creating a Web search tool that would give more reliable answers, the research was driven by clear memories from his medical school education of what was often referred to as “second-year syndrome” or “medical schoolitis.”

He said he remembered “sitting on a cold seat with my legs dangling off the examination table,” convinced that he was suffering from a rare and incurable skin disease.

While the doctor was out of the room, Mr. Horvitz said, he took a look at his medical chart and saw that the doctor’s notes read, “Eric is in medical school, and he has been reading a lot.”

The researchers said that Web searchers’ propensity to jump to awful conclusions was basic human behavior that has been noted by research scientists for decades.

In 1974, the psychologists Amos Tversky and Daniel Kahneman wrote a seminal paper about decisions that are based on beliefs about the likelihood of uncertain events, like the outcome of an election or the future value of the dollar.

They said that people usually employ common sense rules to aid in decisions. The rules can be quite useful, but they also frequently lead to systematic errors in judgment.

The Microsoft researchers noted that reliance on the rankings of Web search results contributes a similar bias to the judgments people make about illness.

MSR-TR-2008-178
Cyberchondria: Studies of the Escalation of Medical Concerns in Web Search
Ryen White & Eric Horvitz

November 2008

Link to Microsoft research abstract

Judgment under Uncertainty: Heuristics and Biases
Amos Tversky and Daniel Kahneman
Science
27 September 1974 185: 1124-1131 [DOI: 10.1126/science.185.4157.1124] (in Articles)
Link to Science abstract

Link to New York Times article

Monday, November 24, 2008

Matchstalk men and Matchstalk cats and dogs

off-label prescribing

Science Daily (November 24, 2008)

14 Drugs Identified As Most Urgently Needing Study For Off-label Use

Physicians and policy-makers know that drugs are frequently prescribed to treat certain diseases despite a lack of FDA approval — a practice known as off-label prescribing. Yet they say the problem is so big they don't know how to begin tackling it.

A potential game plan now exists. A group of researchers has developed a list of 14 widely prescribed medications most urgently in need of additional study to determine how effective and safe they are for their off-label uses. Antidepressants and antipsychotics are the most prominent classes of drugs on the list, which specifically targets drugs that have high levels of off-label use without good scientific backing.

"Off-label prescribing means that we're venturing into uncharted territory where we lack the usual level of evidence presented to the FDA that tells us these drugs are safe and effective," said Randall Stafford, MD, PhD, associate professor of medicine at the Stanford Prevention Research Center, who is the senior author of the study. "This list of priority drugs might be a start for confronting the problem of off-label use with limited evidence."

Stafford collaborated on the research with lead author Surrey Walton, PhD, assistant professor of pharmacy administration at the University of Illinois-Chicago, and other researchers at UIC and the University of Chicago.

At the top of the list was quetiapine (brand name Seroquel), an antipsychotic approved by the U.S. Food and Drug Administration in 1997 for treating schizophrenia. Not only did this drug lead all others in its high rate of off-label uses with limited evidence (76 percent of all uses of the drug), it also had features that raised additional concerns, including its high cost at $207 per prescription, heavy marketing and the presence of a "black-box" warning from the FDA, Stafford said.

Rounding out the top five were warfarin, escitalopram, risperidone and montelukast.

The most common off-label use for six of the 14 drugs on the list was for bipolar disorder. "Many of the drugs and the conditions on the list represent situations where inadequate response to treatment is common and where drug side-effects are frequent," Stafford said. "Not only are these areas where patients and physicians are naturally interested in trying off-label therapies, but areas targeted for expansion by the makers of these drugs.

"When the volume of off-label use of any drug reaches the magnitude that we're documenting, it suggests a role of the pharmaceutical industry in facilitating these types of uses," he added.

Although companies are largely prohibited from marketing off-label uses to physicians and consumers, they make use of exceptions or may market drugs illegally, Stafford said. Companies are allowed to share with physicians any published research that supports off-label uses. Several recent lawsuits have identified systematic plans on the part of some companies to market their products for off-label uses, he noted.

To come up with a plan for determining which drugs were most in need of additional research for off-label use, Stafford and his colleagues convened a panel of nine experts from the FDA, the health-insurance industry, the pharmaceutical industry and academia. Based on the panel's input, the researchers identified three factors to help them prioritize the drugs that should appear on the list, including:

  • The volume of off-label drug use with inadequate evidence supporting that use (based on a large, ongoing national survey of physician prescribing patterns conducted by IMS Health, a private market-research company).
  • The safety of the drug (based on any safety warnings issued by the FDA).
  • A composite of the drug's cost, how long it had been on the market and the amount spent marketing the drug.

After collecting the information, the researchers computed the drug rankings in each category and then came up with an overall list of the 14 drugs most in need of additional study. "Despite examining the data in a variety of ways by providing more or less emphasis on certain factors, we still came up with a very consistent list of drugs," Stafford said.

Clinical indications associated with on-label and off-label uses for top 14 drugs. (Credit: Image courtesy of Stanford University Medical Center)

reference

Prioritizing Future Research on Off-Label Prescribing: Results of a Quantitative Evaluation
Surrey M. Walton, Ph.D et al
Pharmacotherapy,Volume: 28 | Issue: 12 Cover date: December 2008 Page(s): 1443-1452 doi:10.1592/phco.28.12.1443

Link to Pharmacotherapy abstract

Link to Science Daily article

Vaccine stratergy

Science Daily (November 24, 2008)

Strategy For Predicting Immunity Of Vaccines Developed

In the first study of its kind, researchers at the Yerkes National Primate Research Center and Emory Vaccine Center, Emory University, have developed a multidisciplinary approach involving immunology, genomics and bioinformatics to predict the immunity of a vaccine without exposing individuals to infection. This approach addresses a long-standing challenge in the development of vaccines--that of only being able to determine immunity or effectiveness long after vaccination and, often, only after being exposed to infection.

The study, which used the yellow fever vaccine (YF-17D) as a model, represents a long awaited step forward in vaccine immunology and predictive health.
YF-17D is one of the most successful vaccines ever developed and has been administered to nearly half a billion people over the last 70 years.

"A single shot of the vaccine induces immunity in many people for nearly 30 years," says Bali Pulendran, PhD, lead Yerkes researcher of the study and professor in the Department of Pathology and Laboratory Medicine at Emory University School of Medicine. "Despite the great success of the yellow fever vaccine, little has been known about the immunological mechanisms that make it effective," he continues.

The researchers used YF-17D to predict the body's ability shortly after immunization to stimulate a strong and enduring immunity. Researchers vaccinated 15 healthy individuals with YF-17D and studied the T cell and antibody responses in their blood. There was a striking variation in these responses between individuals. Analysis of gene expression patterns in white blood cells revealed in the majority of the individuals the vaccine induced a network of genes involved in the early innate immune response against viruses.

"Using a bioinformatics approach, we were able to identify distinct gene signatures that correlated with the T cell response and the antibody response induced by the vaccine," says Pulendran. "To determine whether these gene signatures could predict immune response, we vaccinated a second group of individuals and were able to predict with up to 90 percent accuracy which of the vaccinated individuals would develop a strong T or B cell immunity to yellow fever."

Pulendran and his colleagues are now working to determine whether this approach can be used to predict the effectiveness of other vaccines, including flu vaccines. The ability to successfully predict the immunity and effectiveness of vaccines would facilitate the rapid evaluation of new and emerging vaccines, and the identification of individuals who are unlikely to be protected by a vaccine.

reference:

Systems biology approach predicts immunogenicity of the yellow fever vaccine in humans.
Troy D. Querec et al
Nature Immunology
, Online November 23, 2008
doi:10.1038/ni.1688
Link to Nature Immunology abstract

Link to Science Daily article