December 30, 2005

'Coaching' in labor makes little difference

When a woman is giving birth, having a "coach" tell her to push during contractions makes almost no difference in shortening labor, and may actually increase her risk of subsequent problems with her bladder, scientists at UT Southwestern Medical Center have found.

For the most part, it doesn't matter whether the mother is coached or not, the scientists report in the recent issue of the American Journal of Obstetrics and Gynecology. And scientists noted that further study must be done to determine if bladder problems were permanent.

"Oftentimes, it's best for the patient to do what's more comfortable for her," said Dr. Steven Bloom, lead author of the paper and interim chair of obstetrics and gynecology at UT Southwestern.

In the study, UT Southwestern scientists focused on second-stage labor - the time in which the cervix is fully dilated and the baby begins to descend. This report follows an earlier one that found a rise in pelvic-floor problems among coached women.

The new study involved 320 women at Parkland Memorial Hospital who were giving birth for the first time, had uncomplicated pregnancies and did not receive epidural anesthesia. They were randomly assigned, with both groups tended by nurse-midwives. Of the two groups, 163 were coached to push for 10 seconds during a contraction, and 157 told to "do what comes naturally".

For women who were randomly assigned to the coaching group, the second stage of labor was shortened by 13 minutes, from 59 to 46 minutes.

"There were no other findings to show that coaching or not coaching was advantageous or harmful," Dr. Bloom said.

The earlier study, reported in the recent issue of Obstetrics and Gynecology, involved the same group of women. In it, scientists investigated whether coaching causes long-term problems to the mother's pelvic region.........

Emily      Permalink


December 30, 2005

Patients With Breast Implants Frequently Develop Complications

Almost one-third of women who underwent reconstructive breast implantation after mastectomy had at least one short-term complication in the chest or breast area, with one in five women requiring additional surgery, as per a studyin the recent issue of Archives of Surgery, one of the JAMA/Archives journals.

Breast cancer is the most common malignancy among women in North American, Europe, Australia, New Zealand and some parts of South America, according to background information in the article. Women with breast cancer and their physicians may face several choices in the course of therapy, including whether to remove the breast (mastectomy) or undergo breast-conserving therapies, when and whether to reconstruct the breast following mastectomy and what materials to use in doing so. Surgeons performing postmastectomy reconstruction can form the new breast from flaps of skin and other tissue from the woman's body (autologous tissue) or insert an implant, and sometimes use both techniques at once. A number of women choose implants alone because the procedure is simpler and requires less operation time than those using autologous tissue, and it can preserve the color of the skin of the breast and possibly some of its sensitivity.

Trine F. Henrikson, M.D., of the Danish Registry for Plastic Surgery of the Breast (DPB), Copenhagen, Denmark, and his colleagues analyzed data from 574 women in the registry who underwent postmastectomy breast reconstruction between June 1, 1999, and July 24, 2003. The patients' surgeons reported the dates and details of each implantation and filled out follow-up forms when the women returned for subsequent visits. The women, ages 21 to 78 years with a mean (average) age of 51 years, were monitored through Sept. 15, 2003.

Following their first implantation, 31 percent of the women developed at least one adverse event, 16 percent developed two complications and 8 percent experienced three or more during the course of the study. The most common complications were infection, blood clotting, seroma (collection of serum in the tissues) and skin perforation. Forty-nine percent of these complications occurred within three months and 67 percent within six months.........

Emily      Permalink


December 28, 2005

Dramatic Increase Bariatric Surgeries

The number of bariatric surgeries performed in the U.S. increased by 450 percent between 1998 and 2002, a growth the scientists say could be linked with use of the minimally invasive laparoscopic technique, according to an article in the recent issue of Archives of Surgery, one of the JAMA/Archives journals.

Currently, surgery is the only effective sustained weight loss option for patients with morbid obesity, according to background information in the article. "The increased enthusiasm for bariatric surgery coincides with the development and dissemination of the laparoscopic approach to bariatric surgery," the authors write. The American Society for Bariatric Surgery (ASBS) estimated that approximately 140,000 bariatric procedures would be performed in 2004.

Ninh T. Nguyen, M.D., and his colleagues from the University of California, Irvine Medical Center, Orange, evaluated Nationwide Inpatient Sample (NIS) data for patients who underwent bariatric surgery for the therapy of morbid obesity from 1998 through 2002 to see if the recent growth in bariatric operations correlated with the widespread use of laparoscopic bariatric surgery.

Between 1998 and 2002, the number of bariatric operations performed in the U.S. increased by 450 percent, from 12,775 to 70,256 cases. Most of the bariatric operations consisted of Roux-en-Y gastric bypass, which increased from 78 percent of bariatric surgeries in 1998 to 92 percent in 2002. Laparoscopic bariatric surgery also increased, from 2.1 percent to 17.9 percent of bariatric surgeries from 1998 to 2002. The number of institutions that perform bariatric surgery increased from 131 to 323. The scientists also saw an increase in the number of bariatric surgeons with membership in the American Society for Bariatric Surgery, from 258 to 631 members.........

Sue      Permalink


December 28, 2005

Smoking Associated With Psoriasis

Cigarette smoking is associated with the clinical severity of the skin disease psoriasis, and both smoking and obesity are more prevalent among psoriasis patients, according to two studies in the recent issue of theArchives of Dermatology, one of the JAMA/Archives journals.

Psoriasis is a chronic, persistent, lifelong disease characterized by scaly red plaques on the surface of the skin. Eventhough psoriasis is not a life-threatening disease, the disability experienced by patients with psoriasis is comparable with that of patients with other chronic illnesses, such as heart disease, diabetes, cancer, and depression, according to background information in the article. Cigarette smoking is a risk factor for a number of chronic diseases, including psoriasis, but little is known about the effect of smoking on psoriasis severity.

Cristina Fortes, Ph.D., of Istituto di Ricovero e Cura a Carattere Scientifico, Rome, Italy, and his colleagues conducted a cross-sectional study to evaluate the association between different components of smoking history and the clinical severity of psoriasis. They analyzed data on 818 adults with psoriasis in inpatient wards of a hospital for skin diseases.

"Specifically, patients who smoked more than a pack of cigarettes (more than 20 cigarettes) daily had twice the risk of more severe psoriasis compared with those who smoked ten cigarettes or less per day," the authors report.

Cigarette-years, measured as the product of the intensity and duration of smoking, significantly increased the risk of clinically more severe psoriasis. "Separate analyses for men and women showed that the effect of cigarette-years on psoriasis severity was stronger for women than for men," the authors write.

"Smoking is associated with the clinical severity of psoriasis and highlights the importance of smoking cessation in patients with psoriasis," they conclude.........

Sue      Permalink


December 28, 2005

Recipients Of Cochlear Implants

Among elderly patients with profound hearing loss, age at time of receipt of an electronic hearing device known as a cochlear implant does not predict subsequent hearing ability, as per a studyin the recent issue of the Archives of Otolaryngology-Head and Neck Surgery, one of the JAMA/Archives journals.

Among the 35 million people in the United States aged 65 and older, between 250,000 and 400,000 have severe to profound hearing loss. Psychological disturbances, social and emotional handicaps, and significant reductions in mental and physical functioning are known to be associated with advanced levels of hearing loss in elderly people, according to background information in the article. A question of growing importance is whether cochlear implantation can address these concerns for elderly patients. A cochlear implant is a small, complex electronic device that includes a microphone, a speech processor, a transmitter and receiver/stimulator, and electrodes. It is implanted and connected to the inner ear to help people with certain types of hearing loss to hear.

Janice Leung, A.B., and his colleagues at The Johns Hopkins Hospital, Baltimore, Md., examined the performance of multichannel cochlear implant recipients in a large database of adult subjects. The scientists analyzed data on 749 adolescents and adults with profound hearing loss who underwent implantation at The Johns Hopkins Hospital and in two clinical trials at the Cochlear Corporation, Englewood, Colo., and Advanced Bionics, Sylmar, Calif. The authors used statistical modeling techniques to identify factors that predict outcomes after cochlear implantation. They examined the difference between baseline performance on monosyllabic word recognition, and performance within the first year of implantation.........

Sue      Permalink


December 28, 2005

More Noise In Gene Expression

Human identical twins have different fingerprints and march to the beat of subtly different phenotypes, an indication of heterogeneity which led bioengineering scientists at the University of California, San Diego (UCSD) to devised computer algorithms that identify the underlying sources of variation at the basic level of life: unscripted fluctuations within individual cells and variations between identical cells.

"Researchers might assume that natural selection would prune any sloppiness at the level of gene expression, but recent studies by our group at UCSD and others have shown that is definitely not the case," said Jeff Hasty, a bioengineering professor at UCSD's Jacobs School of Engineering. "A number of individual genes produce less than 10 copies of regulatory messenger molecules, which is such a small number that it makes clockwork-like regularity of downstream cellular circuits statistically impossible. Our group and others have detected and classified significant downstream fluctuations that result from this source of 'intrinsic noise' in gene expression."

Hasty leads a team of scientists at UCSD that will report in a Dec. 21 advanced online publication by Nature a mathematical description of "extrinsic noise," an even larger component of variation in gene expression. This second type of noise results because no two geneticcally identical cells can keep the same time. The measurement of extrinsic noise was based on experiments involving baker's yeast, Saccharomyces cerevisiae, but the phenomenon and the way it is described mathematically would apply to other types of cells and other species.

"Individual yeast cells exist at various stages of their growth cycle, and this extrinsic variability explains a large component of the noise that must be accounted for in creating a mathematical model of the cell," said Dmitri Volfson, project scientist and a co-author of the study. "In this case, one yeast cell may be preparing to divide, another may be the result of a recent division, and the phenotypes of these two otherwise identical cells can be very different."........

Scott      Permalink


December 28, 2005

Two Million Americans Carry MRSA

New research estimates that about 2 million people carry a strain of drug-resistant bacteria in their noses. This research, which was conducted by the Centers for Disease Control and Prevention (CDC), is the first reliable nationwide estimate of colonization with Staphylococcus aureus, including methicillin-resistant Staphylococcus aureus (MRSA). It is published in the Jan. 15 issue of The Journal of Infectious Diseases, now available online.

Those colonized with normal strains of staph are at higher risk of infection with the bacterium, which can lead to conditions ranging from mild skin infections to fatal toxic shock syndrome. MRSA causes more difficult-to-treat and, sometimes, more virulent illnesses. MRSA was once primarily a problem in hospitals, but is now a growing problem in communities around the country.

Matthew J. Kuehnert, MD, and his colleagues collected samples from nearly 10,000 participants in the 2001-2002 National Health and Nutritional Examination Survey, a representative sample of the U.S. population.

Nearly one-third were found to be colonized with staph. Prevalence was highest among males and children between 6 and 11 years old. MRSA prevalence was 0.8 percent. MRSA was highest among women and those older than 60, but those colonized with strains usually associated with community-associated MRSA were more likely to be younger and black.

Overall, strains and toxins previously found to be associated with community-associated MRSA were unusual. The genetic diversity of strains was remarkable-about half of isolates, including MRSA strains, had unique molecular fingerprinting patterns, and some fell outside recognized groups.

"There is a lot about staph colonization we don't know," Dr. Kuehnert said. "Interestingly, carriage of certain strains do seem to vary by sociodemographics, particularly age and race. We need to learn more in order to allow design of new, more effective interventions," he added, including vaccines or antimicrobial therapy. "Data from subsequent survey years may determine whether there are ongoing trends in colonization".........

Mark      Permalink


December 28, 2005

Eradication of Polio Nears

Polio is on track to become only the second disease ever eradicated. In two studies in the Dec. 15 issue of The Journal of Infectious Diseases, now available online, researchers are working to ensure that once it is gone, it stays gone. One study reduces concerns that people whose immune systems were weakened by HIV would re-introduce poliovirus into the community. The other study looks at the how switching forms of vaccine from a live, attenuated vaccine to an inactivated version may affect communities.

Oral polio vaccine (OPV), one of the vaccines instrumental in driving the disease to near-eradication, contains weakened live virus strains. The vaccine is highly effective, easy to administer, relatively inexpensive, and has been used for more than 40 years. Those given the vaccine excrete, or "shed," virus in their stool. There is some concern over the use of OPV, however, because vaccine-derived poliovirus (VDPV) can occasionally cause another form of polio.

Furthermore, in rare cases, immunodeficient persons have shown prolonged shedding of VDPV, which may be transmitted to contacts, thus potentially re-introducing polio into the community. Concerns had been raised that this issue would be a particular challenge in countries with high HIV prevalence.

Karen Hennessey, PhD, MSPH, and his colleagues in Cote d'Ivoire and at the Centers for Disease Control and Prevention examined the duration of shedding of oral poliomyelitis vaccine by individuals with HIV infection.

Dr. Hennessey and his colleagues tested stool specimens at various intervals following vaccination. Out of a total of 419 adults with HIV infection, no poliovirus was isolated from any of the specimens. Because of these results, it is likely that fewer than 1 percent of adults with HIV infection experience prolonged virus shedding when exposed to OPV, "and therefore probably represent minimal risk of re-introducing vaccine virus into the population after poliovirus has been eradicated," the authors concluded.........

Mark      Permalink


December 28, 2005

How a High-Fat Diet Causes Type 2 Diabetes?

Howard Hughes Medical Institute scientists have discovered a molecular link between a high-fat, Western-style diet, and the onset of type 2 diabetes. In studies in mice, the researchers showed that a high-fat diet disrupts insulin production, resulting in the classic signs of type 2 diabetes.

In an article published in the December 29, 2005, issue of the journal Cell, the scientists report that knocking out a single gene encoding the enzyme GnT-4a glycosyltransferase (GnT-4a ) disrupts insulin production. Importantly, the researchers showed that a high-fat diet suppresses the activity of GnT-4a and leads to type 2 diabetes due to failure of the pancreatic beta cells.

"We have discovered a mechanistic explanation for beta cell failure in response to a high-fat diet and obesity, a molecular trigger which begins the chain of events leading from hyperglycemia to insulin resistance and type 2 diabetes," said Jamey Marth, a Howard Hughes Medical Institute investigator at the University of California, San Diego (UCSD). Marth and first author Kazuaki Ohtsubo at UCSD collaborated on the studies with scientists from the Kirin Brewery Co. Ltd., and the University of Fukui, both in Japan.

The discovery of the link between diet and insulin production offers new information that may aid in the development of therapys that target the early stages of type 2 diabetes. In its earliest phases, the disease causes failure of insulin-secreting beta cells in the pancreas, which leads to elevated blood glucose levels. As the disease progresses, the insulin-secreting beta cells overcompensate for the elevated blood glucose, and eventually pump out too much insulin. This leads to insulin resistance and full-blown type 2 diabetes.

Worldwide, more than 200 million people have type 2 diabetes, and close to 20 million people in the United States have been diagnosed with the disorder. The new studies suggest that people with an inherited predisposition to type 2 diabetes might have variations in the gene for GnT-4a, said the researchers.........

JoAnn      Permalink


December 28, 2005

Defeating Malarial Parasite Defense

The world's deadliest malaria parasite, Plasmodium falciparum, sneaks past the human immune system with the help of a wardrobe of invisibility cloaks. If a person's immune cells learn to recognize one of the parasite's a number of camouflage proteins, the surviving invaders can swap disguises and slip away again to cause more damage. Malaria kills an estimated 2.7 million people annually worldwide, 75 percent of them children in Africa.

Howard Hughes Medical Institute (HHMI) international research scholars in Australia have determined how P. falciparum can turn on one cloaking gene and keep dozens of others silent until each is needed in turn. Their findings, published in the December 28, 2005, issue of Nature, reveal the mechanism of action of the genetic machinery thought to be the key to the parasite's survival.

A DNA sequence near the start of a cloaking gene, known as the gene's promoter, not only turns up production of its protein, but also keeps all other cloaking genes under wraps, according to Alan Cowman and Brendan Crabb, HHMI international research scholars at the Walter and Eliza Hall Institute of Medical Research in Melbourne, Australia, and their co-authors. "The promoter is all you need for activation and silencing," Cowman said. "It's the main site of action where everything is happening."

Malaria parasites enter human blood from infected mosquitoes. The organisms invade and promptly remodel red blood cells. They decorate the surface of the cells they occupy with a protein called PfEMP1, made by the var gene family.

Using this versatile surface protein, the parasite evades the host's immune system using two basic strategies. First, the protein sticks infected red blood cells to the blood vessel lining, removing the infected cells from circulation, where they would probably be destroyed.........

Mark      Permalink