September 10, 2008, 8:53 PM CT

Cryopreservation techniques bring hopes for women

Emerging cryopreservation techniques are increasing hope of restoring fertility for women after diseases such as ovary cancer that lead to destruction of reproductive tissue. The same techniques can also be used to maintain stocks of farm animals, and protect against extinction of endangered animal species by maintaining banks of ovarian tissue or even nascent embryos that can used to produce offspring at some point in the future.

Until now these clearly related fields of research concerning preservation of animal and human ovarian tissue have been largely separate, but are now coming together to reinforce each other, following a highly successful workshop on cryopreservation of ovarian tissue, organised by the European Science Foundation (ESF). The human and animals cryopreservation fields have much to teach each other, and progress in both is likely to be accelerated as a result of growing collaboration, as per the ESF workshop's convenor Claus Yding Andersen.

Both parties can learn from each other," said Andersen. "Experiments which cannot be performed in women can be done in animal species," he noted, pointing out that much of the progress in humans has come as a result of animal experiments. But it is in humans where most successful transplantations of frozen ovarian tissue after thawing have been carried out, and where greatest experience in the field has been gained. Therefore the ESF conference considered how this could be applied to conservation of endangered species. "The vast experience in women, with several children born as a result of transplantation of frozen/thawed ovarian tissue, can be applied in endangered species to know where to implant and how to obtain pregnancies," said Andersen. The techniques will also be valuable in agriculture, for preserving ovaries of farm animals in tissue banks with the potential for subsequent re-creation......... Posted by: Rose      Read more         Source

April 17, 2008, 8:22 PM CT

Will screening for aortic aneurysm be effective?

Pilot screening programmes for abdominal aortic aneurysms in men aged 65 are due to be launched in England this year, but is this move too hasty? Two experts debate the issue in this weeks BMJ.

Around 90% of people with a ruptured aortic aneurysm die. But if the aneurysm is discovered before it ruptures and is repaired by an experienced vascular surgeon, mortality is around 7.4%, writes James Johnson, consultant surgeon at Halton General Hospital, Runcorn.

Around 5% of men aged between 65 and 74 have abdominal aortic aneurysms, but they rarely cause symptoms, so screening in this age group would potentially ensure that most aortic aneurysms are diagnosed and repaired.

But the case for screening is not clear-cut claims Johnson.

He points to wide variations in the mortality for surgical repair between hospitals in England. In addition, a number of patients will not be fit enough to have a repairaneurysm is a disease that rarely exists in isolation. Most patients will also have hypertension, or a history of myocardial infarction, stroke or diabetes.

As a result, a number of patients will be left with the knowledge that they have a life threatening condition that is liable to cause sudden death and that nothing can be done about it, writes Johnson......... Posted by: Rose      Read more         Source

April 17, 2008, 8:19 PM CT

Study finds 1 in 5 Iraq and Afghanistan veterans suffer from PTSD

Nearly 20 percent of military service members who have returned from Iraq and Afghanistan -- 300,000 in all -- report symptoms of post traumatic stress disorder or major depression, yet only slight more than half have sought therapy, as per a new RAND Corporation study.

In addition, scientists found about 19 percent of returning service members report that they experienced a possible traumatic brain injury while deployed, with 7 percent reporting both a probable brain injury and current PTSD or major depression.

A number of service members said they do not seek therapy for psychological illnesses because they fear it will harm their careers. But even among those who do seek help for PTSD or major depression, only about half receive therapy that scientists consider minimally adequate for their illnesses.

In the first analysis of its kind, scientists estimate that PTSD and depression among returning service members will cost the nation as much as $6.2 billion in the two years following deployment -- an amount that includes both direct medical care and costs for lost productivity and suicide. Investing in more high-quality therapy could save close to $2 billion within two years by substantially reducing those indirect costs, the 500-page study concludes......... Posted by: Rose      Read more         Source

April 17, 2008, 8:17 PM CT

Treatment To Prevent Allergic Reactions to Food

Scientists at National Jewish Medical and Research Center are conducting trials to evaluate a method to prevent allergic reactions to food. They are feeding peanut- and egg-allergic people increasing doses of an investigational protein extract from the foods to see if they can induce the participants' immune systems to tolerate the food.

"We hope these trials will lead to the development of the first active, preventive therapy for food allergies," said pediatric allergist David Fleischer, MD, principal investigator for the National Jewish studies. "If proved to be successful, it would offer great hope for allergic patients and their families, whose lives are haunted by a daily fear of food".

Currently the only advice doctors can give to the estimated 12 million Americans who have food allergies is to avoid the food and carry a self-injectable dose of epinephrine in case they accidentally consume the allergenic food. There is no therapy available to prevent an allergic reaction to food other than strict avoidance of that food. It can often be difficult to determine if a food contains peanuts or eggs, particularly when eating at a restaurant or food prepared by another person. It can even be difficult recognizing egg and peanut proteins listed on food ingredient labels, particularly from products that are not manufactured in the U.S. As a result, thousands of people rush to emergency rooms every year suffering severe allergic reactions to food. As a number of as 200 people die from allergic reactions to food each year......... Posted by: Rose      Read more         Source

March 24, 2008, 8:24 PM CT

Artificial Enzymes That Also Undergo 'Evolution In A Test Tube'

Mankind triumphed in a recent 'competition' against nature when researchers succeeded in creating a new type of enzyme for a reaction for which no naturally occurring enzyme has evolved. This achievement opens the door to the development of a variety of potential applications in medicine and industry.

Enzymes are, without a doubt, a valuable model for understanding the intricate works of nature. These molecular machines - which without them, life would not exist - are responsible for initiating chemical reactions within the body. Millions of years of natural selection have fine-tuned the activity of such enzymes, allowing chemical reactions to take place millions of times faster. In order to create artificial enzymes, a comprehensive understanding of the structure of natural enzymes, their mode of action, as well as advanced protein engineering techniques is needed. A team of researchers from the University of Washington, Seattle, and the Weizmann Institute of Science, Israel, made a crucial breakthrough toward this endeavor. Their findings have recently been reported in the scientific journal Nature.

Enzymes are biological catalysts that are made from a string of amino acids, which fold into specific three-dimensional protein structures. The scientists' aim was to create an enzyme for a specific chemical reaction whereby a proton (a positively charged hydrogen atom) is removed from carbon - a highly demanding reaction and rate-determining step in numerous processes for which no enzymes currently exist, but which would be beneficial in helping to speed up the reaction. During the first heat of the 'competition,' the research team designed the 'heart' of the enzymatic machine - the active site - where the chemical reactions take place......... Posted by: Rose      Read more         Source

March 24, 2008, 8:21 PM CT

Risky teen behavior may not occur at home or school?

How can scientists track where teens go when not in or near home or school to see if this movement has an impact on health-related behavior such as smoking or sexual activity" The answer is through that ubiquitous teen accessory the cell phone.

In a paper reported in the recent issue of the Journal of Adolescent Health scientists from Indiana University School of Medicine report on a pilot study which reviewed the feasibility of using global position system -enabled cell phones to track where 14- to 16-year-old girls spent their time.

We didnt know if the technology would work, if the kids would take the cell phones with them or would leave them at home. But they did carry the phones and the GPS data revealed that they were spending more time away from home, school and surrounding areas than anticipated. Learning that we were able to track their movement is important because prior studies which have looked at the effect of environment on teens have focused only on home, school and surrounding areas, said Sarah Wiehe, M.D., M.P.H., an assistant professor of pediatrics at the IU School of Medicine and a Regenstrief Institute affiliated scientist.

A persons environment in some way influences or is at least linked to their health and health outcomes and in the case of adolescents their health behaviors. But we dont have a great idea of why that association exists. What in the environment is contributing to behavior choices such as drug use" When tracked with GPS we know where the teens are and when they are there but we dont know what they are doing. Now that we know that the technology works, that the girls took their phones with them, we need to learn the characteristics of the environments in which they find themselves, she added......... Posted by: Rose      Read more         Source

March 24, 2008, 8:19 PM CT

Staph aureus resists our natural defenses

Scientists at the University of Washington have uncovered how the bacterium Staphylococcus aureus, including the notorious MRSA (methicillin-resistant Staph aureus) superbug strains, resists our body's natural defenses against infection. The work, which was featured on the cover of the March 21 issue of Science, could lead to new ways to fight the bacteria.

Dr. Ferric Fang, UW professor of laboratory medicine and microbiology, and his UW colleagues Dr. Anthony Richardson and Dr. Stephen Libby set out to determine what makes Staph aureus a better pathogen than other bacteria. They focused on a chemical compound called nitric oxide (NO), a natural antibiotic that our cells excrete to protect us from pathogens. For most bacteria, NO creates an environment that keeps invading microbes from undergoing respiration or fermentation, vital chemical processes that allow bacteria to grow.

The scientists observed that Staph aureus has a mechanism that allows it to produce lactic acid in the presence of NO, which allows it to maintain its chemical balance and keep growing and thriving in the harsh host environment. When Staph aureus is exposed to NO, it produces the novel enzyme responsible for lactic acid production, along with another enzyme that converts NO to non-toxic products. NO is usually found in the nose and nasal passages, and is meant to protect people against disease-causing microbes. But Staph aureus is usually found in the nose despite the presence of NO, the scientists explained......... Posted by: Rose      Read more         Source

March 7, 2008, 5:37 AM CT

Engineered protein shows potential as a strep vaccine

A University of California, San Diego-led research team has demonstrated that immunization with a stabilized version of a protein found on Streptococcus bacteria can provide protection against Strep infections, which afflict more than 600 million people each year and kill 400,000.

In the March 7 issue of the journal Science, the scientists describe, for the first time, the detailed structure of the streptococcal M protein, which is critical to the virulence of Group A Streptococcus (GAS). GAS causes a wide variety of human diseases including strep throat, rheumatic fever, and the life-threatening flesh-eating syndrome called necrotizing fasciitis. Studies were performed using M1 protein, which represents the version of M protein present on the most common disease-associated GAS strains.

The team also produced a variant of M1 protein that stimulates the immune system in mice, without the serious side effects caused by natural M1 protein. They say that their results should help researchers develop M1 protein-based vaccines against GAS.

Using X-ray crystallography, we determined that M1 protein has an irregular, unstable structure, explained Partho Ghosh, a professor of chemistry and biochemistry in UCSDs Division of Physical Sciences. We created a modified version of M1 with a more stable structure, and observed that it is just as effective at eliciting an immune reaction, but safer than the original version of M1, which has serious drawbacks to its use in a vaccine......... Posted by: Rose      Read more         Source

March 3, 2008, 9:51 PM CT

Gender differences in language appear biological

Eventhough scientists have long agreed that girls have superior language abilities than boys, until now no one has clearly provided a biological basis that may account for their differences.

For the first time -- and in unambiguous findings -- scientists from Northwestern University and the University of Haifa show both that areas of the brain linked to language work harder in girls than in boys during language tasks, and that boys and girls rely on different parts of the brain when performing these tasks.

Our findings which suggest that language processing is more sensory in boys and more abstract in girls -- could have major implications for teaching children and even provide support for advocates of single sex classrooms, said Douglas D. Burman, research associate in Northwesterns Roxelyn and Richard Pepper Department of Communication Sciences and Disorders.

Burman is primary author of Sex Differences in Neural Processing of Language Among Children. Co-authored by James R. Booth (Northwestern University) and Tali Bitan (University of Haifa), the article would be reported in the recent issue of the journal Neuropsychologia and now is available online at http://dx.doi.org/10.1016/j.neuropsychologia.2007.12.021.

Using functional magnetic resonance imaging (fMRI), the scientists measured brain activity in 31 boys and in 31 girls aged 9 to 15 as they performed spelling and writing language tasks......... Posted by: Rose      Read more         Source

January 14, 2008, 5:25 PM CT

Genetic determinants of Alzheimer's disease

The Netherlands, January 14, 2008 A rapid and accurate DHPLC assay for determination of apolipoprotein E genotypes has been developed by scientists from the Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China. This assay combines PCR and DHPLC and can be used to conduct efficient genotyping of the human population, which in turn will help in the diagnosis and therapy of Alzheimers disease. A description of the assay has been published this month in the Journal of Alzheimers Disease.

Apolipoprotein E is a predisposing gene of Alzheimers disease and a number of other diseases. APOE has three major alleles, 2, 3 and 4. The combinations of the three common alleles result in six genotypes (22, 33, 44, 23, 34, and 24) that exist within the population. A number of studies indicate that people who have the E4 allele are at greater risk to develop Alzheimer's disease than those with the E3 allele and that the E2 allele may even help resist Alzheimer's disease. As a result, the rapid and accurate determination of APOE genotypes and the assessment of disease predisposition will be extremely valuable in augmenting the clinical diagnosis and therapy of the disease.

The medical genetic team, led by Professor Xiang-Min Xu at Southern Medical University, developed the assay during research funded by the National Science Fund for Distinguished Young Scholars of China. The polymerase chain reaction (PCR) was designed to generate the 191-bp amplicons containing two common polymorphisms within codons 112 and 158 in exon4 of the APOE gene. The PCR amplicons for each sample were subjected to denaturing high-performance liquid chromatography (DHPLC) analysis, which waccording toformed under partially denaturing conditions as determined by profiling the mixture of a tested sample and a homozygous standard control amplicon at the given ratio. In almost 300 samples detected, the accuracy of the assay reached 100%......... Posted by: Rose      Read more         Source