Some of the most beneficial discoveries were realized by chance. For Prof. Nava Dekel of the Weizmann Institute's biological regulation department, some completely unexpected results of biopsies performed on the uteri of women with fertility problems may hold hope for women trying to conceive. Dekel and a research team that included Drs. Yael Kalma and Yulia Gnainsky, who worked in collaboration with Drs. Amichai Barash and Irit Granot of the Kaplan Medical Center in Rehovot, had been investigating a protein they suspected plays a role in the implantation of a fertilized egg in the uterus. The team took biopsies at several stages in the menstrual cycles of 12 women with fertility problems and unsuccessful IVF treatments to see if levels of this protein changed over the course of the cycle. Indeed, the team's research went according to plan and they found evidence pointing to the protein's role. The surprise came soon after: Of the 12 women participating in the study, 11 became pregnant during the next round of IVF. The idea of biopsy incisions - basically small wounds - leading to such a positive outcome was counterintuitive, and Dekel realized something interesting was happening. She and her team repeated the biopsies, this time on a group of 45 volunteers, and compared results to a control group of 89 women who did not undergo biopsy. The results were clear: The procedure doubled a woman's chances of becoming pregnant. On the basis of this and evidence obtained from previous studies, the scientists suggest that some form of mild physical distress, such as a biopsy, may make conditions in the uterus favorable for implantation. Dekel and her team are now looking for the exact mechanisms involved when an unreceptive uterus turns receptive following local injury. They are conducting both animal studies and human clinical trials to identify genes that may play a role. In the future, this accidental finding may give birth to new treatments to improve the success rate of IVF, or even tackle some types of fertility problems directly. FATTENING FIZZ: THE HARD TRUTH ABOUT SOFT DRINKS Pay attention, you four-in-10 Israelis who consume sweetened drinks and sodas during an average day: Nearly a third of Israelis don't know that regularly drinking sugary soft drinks can lead to obesity. In fact, drinking just one non-diet beverage a day means a weight gain of seven kilos per year. The Education Ministry decided recently to remove non-diet beverages from schools starting in September, similar to a decision facilitated by former president Bill Clinton in the US. A new Intersite poll conducted among a representative sample of 502 Jewish adults (for the Israel Center for Bariatric Surgery at Assuta Medical Center in Tel Aviv) found that 10% believe sugary soft drinks are not responsible for health problems; 17% think that drinking them is neither healthful nor fattening; 33% said they are "quite health damaging and fattening"; and 32% acknowledged that they cause health problems and obesity. Another eight percent did not know if such a link exists. Women and higher-income people are more likely to know that these soft drinks can lead to obesity. Two-fifths said that a day prior to the poll they had drunk sweetened non-diet beverages, while half drank one to two glasses and another half drank more than three. Soft drink consumption declines with age, (61% between 18 and 22 years compared to 16% among people over 60) and higher educational level. A glass of regular cola contains 140 calories, and sweetened juice 150 calories. TOBACCO'S 'SLEEPER EFFECT' The urge to smoke again after having tried just one cigarette can lie dormant for more than three years, indicating a "sleeper effect," according to a British study of teenage smoking habits published in the journal Tobacco Control. Young teens who smoked just one cigarette at the age of 11 were twice as likely to take up smoking within the next few years as their peers who resisted the urge, the study shows; this was despite not having smoked in the intervening period. In 2004, 14% of 11-year-olds and 62% of 15-year-olds in England said they had experimented with cigarettes. The researchers base their findings on annual surveys of almost 6,000 11- to 16-year-old pupils attending 36 representative schools across south London. All of the youngsters underwent measurements of salivary cotinine, a biochemical indicator of nicotine intake. By the age of 14, pupils who had given smoking a go just once at the age of 11 were twice as likely to have become regular smokers as their peers who had not. This was the case even after a gap of three years or more. These findings held true irrespective of gender, ethnicity and deprivation - all factors known to influence the likelihood of smoking. Other influential factors, such as whether the parents smoked, or whether the pupil was a bit of a rebel, also had no bearing. The researchers say their findings provide the first clear evidence of a "sleeper effect" or period of "dormant vulnerability," for teenagers who experiment with smoking just the once. Just one cigarette could change the reward pathway in the brain, which might then be activated by triggers such as stress, depression or the school environment, suggest the authors. Alternatively, trying out a cigarette might simply break down the social barriers that prevent teens from smoking, such as fear of displeasing adults, they say.