October 17, 2007, 4:49 AM CT

Study shows reducing class size may be more cost-effective

Reducing the number of students per classroom in U.S. primary schools may be more cost-effective than most public health and medical interventions, as per a research studyby scientists at Columbia University Mailman School of Public Health and the Virginia Commonwealth University. The study indicates that class-size reductions would generate more quality-adjusted life-year gains per dollar invested than the majority of medical interventions. The findings would be reported in the recent issue of the American Journal of Public Health.

The scientists estimated the health and economic effects of reducing class sizes from 2225 students to 1317 students in kindergarten through grade 3 nationwide, based on an intervention tested in Project STAR (Student Teacher Achievement Ratio), a large multi-school randomized trial that began in 1985. Project STAR is considered the highest quality long-term experiment to date in the field of education.

The study shows that a student graduating from high school after attending smaller-sized classes gains an average of 1.7 quality-adjusted life-years and generates a net $168,431 in lifetime revenue. Higher earnings and better job quality enhance access to health insurance coverage, reduce exposure to hazardous work conditions, and provide individuals and families with the necessary resources to move out of unfavorable neighborhoods and to purchase goods and services, says Peter A. Muennig, MD, MPH, assistant professor of Health Policy and Management at the Mailman School. Regardless of class size, the net effect of graduating from high school is roughly equivalent to taking 20 years of bad health off of your life."........ Posted by: Janet      Read more         Source

October 17, 2007, 4:47 AM CT

Gold nanorods to fighting cancer

Scientists have shown how tiny "nanorods" of gold can be triggered by a laser beam to blast holes in the membranes of tumor cells, setting in motion a complex biochemical mechanism that leads to a tumor cell's self-destruction.

Tumor cell membranes often have an abnormally high number of receptor sites to capture molecules of folic acid, or folate, a form of vitamin B that a number of tumor cells crave. The Purdue scientists attached folate to the gold nanorods, enabling them to target the receptors and attach to the tumor cell membranes.

"The cells are then illuminated with light in the near-infrared range," said Ji-Xin Cheng (pronounced Gee-Shin), an assistant professor in Purdue's Weldon School of Biomedical Engineering. "This light can easily pass through tissue but is absorbed by the nanorods and converted rapidly into heat, leading to miniature explosions on the cell surface".

Researchers have recently determined that gold nanorods and other nanostructures can be used to target and destroy tumor cells, but it was generally assumed that cell death was due to the high heat produced by the light-absorbing nanoparticles. The Purdue team discovered, however, that a more complex biochemical scenario is responsible for killing the cells.

"We have observed that rather than cooking the cells to death, the nanorods first punch holes in the membrane, and cell death is then chemically induced, in this case by an influx of calcium," said Alexander Wei, an associate professor of chemistry at Purdue......... Posted by: Janet      Read more         Source

October 16, 2007, 7:44 PM CT

Farm kids have lower risk of asthma

Farm children appear to have a lower risk of asthma than their urban counterparts or even those living in a non-agricultural rural environment, as per a University of Alberta study.

Analysis of two surveys involving 13,524 asthmafree children aged less than 12 years in the ongoing Canadian National Longitudinal Survey of Children and Youth (NLSCY) showed that children living in a farming environment had a lower risk of developing asthma than their counterparts who resided in either non-farming rural environments, such as residential acreages and rural towns, or an urban environment.

The two-year cumulative occurence rate of asthma was only 2.3 per cent in farm children, in comparison to 5.3 per cent for other rural and 5.7 per cent for urban children.

The study was published recently in the journal Respirology.

Farm children of ages one to five years also showed a stronger protective effect against asthma than those aged six to 11 years, possibly due to earlier exposure to the farm environment, said William Midodzi, lead author on the study and a PhD candidate in the Department of Public Health Sciences in the University of Alberta School of Public Health in Edmonton, Canada.

As well, youngsters with parental history of asthma living in farming environments had a reduced risk of asthma in comparison to children living in rural non-farm environments, whereas children with parental history of asthma living in urban areas had a higher risk when compared with children living in rural non-farm environments......... Posted by: JoAnn      Read more         Source

October 16, 2007, 7:38 PM CT

How schizophrenia develops

Schizophrenia may occur, in part, because of a problem in an intermittent on/off switch for a gene involved in making a key chemical messenger in the brain, researchers have found in a study of human brain tissue. The scientists observed that the gene is turned on at increasingly high rates during normal development of the prefrontal cortex, the part of the brain involved in higher functions like thinking and decision-making but that this normal increase may not occur in people with schizophrenia.

The study was funded by the National Institutes of Healths National Institute of Mental Health (NIMH) and National Institute of Child Health and Human Development.

The gene, GAD1, makes an enzyme essential for production of the chemical messenger, called GABA. The more the gene is turned on, the more GABA synthesis can occur, under normal circumstances. GABA helps regulate the flow of electrical traffic that enables brain cells to communicate with each other. It is among the major neurotransmitters in the brain.

Abnormalities in brain development and in GABA synthesis are known to play a role in schizophrenia, but the underlying molecular mechanisms are unknown. In this study, researchers discovered that defects in specific epigenetic actions biochemical reactions that regulate gene activity, such as turning genes on and off so that they can make substances like the GAD1 enzyme are involved......... Posted by: JoAnn      Read more         Source

October 16, 2007, 7:21 PM CT

Ear infection superbug resistant to all pediatric antibiotics

Scientists have discovered a strain of bacteria resistant to all approved drugs used to fight ear infections in children, as per an article would be published tomorrow in the Journal of the American Medical Association (JAMA). A pair of pediatricians discovered the strain because it is their standard practice to perform an uncommon procedure called tympanocentesis (ear tap) on children when several antibiotics fail to clear up their ear infections. The procedure involves puncturing the childs eardrum and draining fluid to relieve pressure and pain. Analyzing the drained fluid is the only way to describe the bacterial strain causing the infection.

Even after the ear tap and additional rounds of antibiotics, infections persisted in a small group of children in a Rochester, New York, pediatric practice, leading to ear tube surgery and, in one case, to permanent hearing loss. The physicians realized they may be dealing with a superbug and tested the children's ear tap fluid at the University of Rochester Medical Center. The tests showed that the superbug, called the 19A strain, could be killed only by an antibiotic (levofloxacin, Levaquin) approved for adults that had a warning in its label against use in children. With no other choice, they treated the children with crushed, adult-approved pills, and it worked......... Posted by: Mark      Read more         Source

October 15, 2007, 9:52 PM CT

Oxytocin Level and Mother-Child Bond

Humans are hard-wired to form enduring bonds with others. One of the primary bonds across the mammalian species is the mother-infant bond. Evolutionarily speaking, it is in a mother's best interest to foster the well-being of her child; however, some mothers just seem a bit more maternal than others do. Now, new research points to a hormone that predicts the level of bonding between mother and child.

In animals, oxytocin, dubbed "the hormone of love and bonding," is critically important for the development of parenting, is elicited during sexual intercourse, and is involved in maintaining close relationships. Animals with no oxytocin exhibit slower pup retrieval and less licking and self-grooming. These findings implicate oxytocin in the bonding process, but little research has been done on this relationship in humans.

Ruth Feldman, psychology professor at Bar-Ilan University in Israel, conducted the first study to demonstrate the links between oxytocin and bonding in human mothers. Feldman and his colleagues measured plasma oxytocin from sixty-two pregnant women during their first trimester, third trimester, and the first postpartum month.

They also observed the mother and child interact, defining the level of attachment along four aspects: gaze, affect, touch, and vocalization. Stronger attachment would mean that the mother focused her gaze mostly on the child, exhibited a positive energy towards the child, maintained constant affectionate and stimulating touch with the child, used a "motherese" speech with the child, and these species-typical maternal behaviors were adapted to the infant's alert state......... Posted by: JoAnn      Read more         Source

October 15, 2007, 6:19 PM CT

Cancer death rate decline doubling

A new report from the nations leading cancer organizations shows cancer death rates decreased on average 2.1 percent per year from 2002 through 2004, nearly twice the annual decrease of 1.1 percent per year from 1993 through 2002. The findings are in the Annual Report to the Nation on the Status of Cancer, 1975-2004, Featuring Cancer in American Indians and Alaska Natives published online October 15, 2007 (www.interscience.wiley.com/cancer/report2007) and appearing in the November 15, 2007, issue of Cancer.

A featured special section provides the most comprehensive cancer data to date for American Indians and Alaska Natives (AI/AN) across the United States. Cancer incidence rates among AI/AN men and women varied two hundred percent among six geographic regions of the country. From 1999 through 2004, AI/AN men from the Northern Plains region and AI/AN women from Alaska and the Northern and Southern Plains regions had higher cancer incidence rates than non-Hispanic white (NHW) men and women in the same areas.

Among the general population, the report suggests that long-term declines in cancer death rates continued through 2004 for both sexes and, despite overall higher death rates for men, the declines from 2002 through 2004 were 2.6 percent per year among men and 1.8 percent per year among women. Death rates decreased for the majority of the top 15 cancers in men and women. Important declines were noted for the three leading causes of cancer deaths in men: lung, prostate and colorectal cancers. In women, deaths rates from colorectal cancer and breast cancer decreased, while the rate of increase for lung cancer deaths slowed substantially......... Posted by: Janet      Read more         Source

October 15, 2007, 6:13 PM CT

Consumption of raw fish: potential health concerns

Two case studies from Japan presented at the 72nd Annual Meeting of the American College of Gastroenterology point to a potential health problem in the United States, as more Americans consume raw fish in the form of sushi and sashimi. Anisakiasis (round worm) is a human parasitic infection caused by the consumption of raw or undercooked seafood containing Anisakis larvae. Consumers should be aware that while larvae for the parasitic worm Anisakis cannot survive in a human host, the ingested larvae can produce severe intestinal problems warranting a visit to the emergency room.

When ingested by humans, the larvae attach themselves to the tissues lining the stomach and intestines, resulting in sudden abdominal pain, nausea, vomiting, and diarrhea. Since the larvae cannot survive in humans and eventually die, intestinal anisakiasis commonly resolves on its own.

Scientists in Japan examined two cases of intestinal anisakiasis presenting as an obstruction of the small intestine. In each case, both patients, ages 64 and 70, were rushed to the emergency room with sudden abdominal pain and vomiting after eating raw sardines as sashimi two days earlier. The diagnosis of anisakiasis in the stomach can easily be confirmed by endoscopy. However, small intestinal anisakiasis is difficult to diagnose. Both patients had abdominal X-rays showed air-fluid levels suggesting a small intestinal obstruction. Using a multidetector-row computed tomography (MDCT), doctors obtained high quality images of the small bowel, and found the intestinal blockage was caused by the presence of Anisakis larvae. Fluid replacement and resting immediately relieved the patients symptoms......... Posted by: Janet      Read more         Source

October 15, 2007, 6:09 PM CT

Night-time acid reflux can impact sleep

As per results of a survey presented at the 72nd Annual Scientific Meeting of the American College of Gastroenterology, nighttime acid reflux, along with some of the less typical manifestations or symptoms of gastroesophageal reflux disease (GERD), is linked to significant sleep impairment.

In a recent national survey, scientists assessed the prevalence of sleep impairment among people with GERD and people without GERD based on response to an Internet survey of a general population of U.S. adults. Using a validated GERD screening tool, 701 respondents were identified with GERD and the remaining were controls. Bonnie Dean, MPH, PhD, of Cerner LifeSciences, Ronnie Fass, MD of the University of Arizona and their research team observed that sleep impairment was more common among people with GERD (41.9 percent) than those without GERD (19.4 percent). Scientists observed that 49.5 percent of respondents with nighttime GERD reported sleeping poorly often or most of the time, in comparison to 36.7 percent of people with daytime GERD.

Using the survey, scientists also assessed sleep impairment among patients experiencing frequent nighttime atypical manifestations of GERD. In this case, Dr. Dean and her colleagues reviewed the subgroup of respondents with GERD, as identified using the validated GERD screener. They observed that atypical manifestations or symptoms of GERD (i.e. coughing, sore throat, snoring, wheezing, choking, and chest pain) were common among those with acid reflux. Of GERD patients, 74 percent had at least one nighttime atypical manifestation. For almost every daytime and nighttime atypical manifestation assessed, more than 20 percent of GERD patients reported their occurrence as frequent (more than 2 days or nights per week). Scientists also observed that sleep impairment was more common among GERD patients with atypical manifestations in comparison to GERD patients with only typical or classic symptoms such as heartburn and acid regurgitation. For eight of the nine nighttime atypical manifestations assessed, the proportion of GERD cases reporting sleep impairment was significantly higher for GERD cases with the atypical manifestation compared with GERD cases without the atypical manifestation......... Posted by: Sue      Read more         Source

October 15, 2007, 4:53 PM CT

Serious, manifestations of acid reflux

A number of people may not realize that symptoms such as chronic cough or chest pain can be caused by acid reflux into the esophagus, because they do not experience classic heartburn symptoms or acid regurgitation. Two new studies presented at the 72nd ACG Annual Scientific Meeting highlight the little known correlation between gastroesophageal reflux and seemingly unrelated problems.

Scientists at the Brigham & Womens Hospital in Boston studied patients in emergency rooms who complained of serious chest pain. They measured and recorded pH levels in the esophagus of 31 patients for two days to determine whether excessive acid caused their chest pain. Scientists found more women than men were being rushed to the emergency room with chest pain that was not correlation to the heart. Abnormal reflux of acid that would fit the diagnosis of GERD was seen in 57 percent of patients. There are two types of acid reflux, supine, which occurs when the patient is sleeping, and upright which occurs when the patient is awake. In this study, men had more upright reflux, while women experienced both reflux during sleep and while they were awake.

As per lead investigator Dr. Julia J. Liu, Often the role of acid reflux has been overlooked as a potential factor in the diagnosis and therapy of patients with serious chest pain. But, it is important for patients never to assume their chest pain is caused by GERD until they have been thoroughly reviewed by a doctor to rule out heart disease. If they experience persistent chest pain, they should seek emergency medical care......... Posted by: Sue      Read more         Source