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Monday, March 31, 2008

MMR Doctor denies submitting kids to painful tests just to prove his Theories

Dr. Andrew Wakefield told a General Medical Council (GMC) disciplinary panel he did not submit young children to painful tests just to further his theories linking vaccinations to autism. He stressed that the tests were clinically necessary to diagnose and treat the young children - he said the children had autistic-like symptoms as well as debilitating bowel diseases.

A decade ago Dr. Wakefield said the MMR vaccine may cause autism.

Professor John Walker-Smith, the doctor of the young children, had ordered all the tests, according to Wakefield. The investigations - including painful colonoscopies, lumbar punctures (taking spinal fluid), brain scans, blood tests, and urine tests - were stopped when they could not reveal a link to the children's problems. He insisted that the well-being of the children was "our foremost consideration".

Dr. Wakefield is not a practicing clinician, he is an academic. He is accused of ordering tests against the children's best interests in order to further his own research - and by doing so breaking rules. However, he says he played no role whatsoever in deciding whether the tests should or should not take place. According to Wakefield, all the parents were very keen for their children to be included in the tests, and knew about the research program.

He said parents had told him about their 'normal' children who developed autism after receiving the MMR vaccine and started investigating a potential link in 1995. He had previously investigated a possible link between the MMR vaccine and Crohn's disease. "They were telling what turned out to be a remarkably consistent story of a normal child who they had lost, who had lost speech, communication, play, interaction with siblings, had sometimes become incontinent … was bloated, off their food, was losing weight, was failing to thrive."

While answering the Panel's questions (during the hearing) several supporters were gathered outside with banners indicating support for Wakefield. Professor Walker-Smith, Professor Simon Murch and Dr. Wakefield all deny serious professional conduct.

According to the Daily Mail, Dr. Wakefield charged over £150 ($300) per hour to a law firm that had planned to sue the vaccine's manufacturer. He invoiced Richard Barr, a lawyer, the hourly rate for investigating alleged dangerous side-effects of the MMR vaccine. Two years later Wakefield published his research paper, alleging a causal link between MMR and autism in young children. However, he did not disclose that he was being paid as an expert adviser for Mr. Barr, who was in legal proceedings against the manufacturers of the MMR vaccine - a clear conflict of interest.

Most of the children who were examined were represented by Mr. Barr. When Dr. Wakefield's report came out, it led to a dramatic drop in the number of children receiving the MMR jab, and a subsequent rise in children developing measles.

According to the Daily Mail, Dr. Wakefield "was also accused of dishonesty in applying for £55,000 of legal-aid money for his research, even though these costs had already been met by the NHS." According to Wakefield, he needed two funding sources for two separate investigations.

Wakefield told the Panel that the Royal Free Hospital's (London) ethics committee had fully approved the invasive tests on the children. Dr. Michael Pegg, who was the Committee's chairman said this was not true - Wakefield suggested that Dr. Pegg's memory is at fault.

The hearing continues.

See Full Article

Thursday, March 27, 2008

Contact Patterns and the Flow of Infectious Diseases

Researchers in Europe have analyzed and modeled social contact patterns in order to better understand the spread of respiratory infections. The study is published in the open-access journal PLoS Medicine.

It is common to use mathematical modeling techniques to understand and predict the impact of infectious diseases. The models help policy officials and researchers make recommendations regarding intervention, treatment, and prevention of infectious and contagious diseases. In assessing the likelihood that a disease will spread among a population, researchers use contact rates - how many people that a person contacts in a day - as a key predictor. Contact rates are usually assumed to follow a certain pattern, but researchers have not yet directly observed these patterns. To improve our understanding of contact rates and to analyze patterns among age groups and social settings, researchers have decided to directly ask people how many contacts they have in a day and then generated models based on these data.

Joël Mossong (Microbiology Unit, Laboratoire National de Santé, Luxembourg and Centre de Recherche Public Santé, Luxembourg) and colleagues from several European nations recruited 7,290 people from Belgium, Germany, Finland, Great Britain, Italy, Luxembourg, The Netherlands, and Poland. The participants recorded basic demographic information and noted physical (kiss, handshake, e.g.) and nonphysical (two-way conversation without skin-to-skin contact) contacts for one day.

The researchers found that the participants averaged 13.4 contacts per day (97,904 contacts in total). The diversity of contact information is summarized below:

* Children had more contacts than adults
* People who live in large households had more contacts
* People had more contacts on weekdays than on Sundays
* Longer duration and higher frequency contact tended to be physical
* People of the same age tended to mix more frequently than people of different ages
* About 70% of daily contacts lasted less longer an hour
* About 75% of contacts with strangers lasted less than 15 minutes

"One of the most important findings of our study is that the age and intensity patterns of contact are remarkably similar across different European countries even though the average number of contacts recorded differed. This similarity implies that the results may well be applicable to other European countries, and that the initial phase of spread of newly emerging infections in susceptible populations, such as SARS was in 2003, is likely to be very similar across Europe and in countries with similar social structures," write the authors.

Mossong and colleagues then modeled the contact patterns using mathematical and statistical techniques. They were also able to create a model of how a respiratory infection epidemic may spread throughout a population. Results predicted that during the initial spread of a respiratory infection, 5- to 19-year olds would suffer the greatest burden. These younger people have many more contacts per day and more contacts within their own age group.

The authors conclude: "Our survey is, to our knowledge, the first population-based prospective survey of mixing patterns pertinent to the spread of airborne and close-contact infectious diseases performed in several European countries using a similar diary methodology. The quantification of these mixing patterns shows a remarkable similarity in degree of assortativeness, which likely results in similar patterns of spread in different populations. This finding represents a significant advance in our understanding of the spread of these infectious diseases and should help to improve the parameterization of mathematical models used to design control strategies."

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Dementia Risk in Old Age linked to Belly Size in Midlife

A new study by researchers from the US and Sweden showed that having a large belly in midlife increased the risk of having dementia in old age, with overweight and obese people with large bellies having double or triple the risk. In other words, while being overweight and obese was a risk factor, the study showed this was significantly affected by where the weight was carried in midlife.

The study is published in the online issue of the journal Neurology, and was conducted by Dr. Rachel Whitmer, who is a research scientist at the Kaiser Permanente Division of Research in Oakland, California, and colleagues.

Previous research has linked waist circumference or central obesity and body mass index (BMI) in elderly people to the risk of developing dementia, and it has also shown that having a large abdomen in midlife is linked to higher risk of heart disease, stroke and diabetes.

But this is the first study to show a link between belly fat in midlife and the risk of developing dementia decades later.

Whitmer and colleagues studied 6,583 health plan members of Kaiser Permanente living in Northern California who had had their sagittal abdominal diameter (SAD) measured between 1964 and 1973 when they were aged between 40 and 45.

SAD, which is a measure of belly density, is taken using a caliper that measures the distance from the back to the upper abdomen, when positioned midway between the top of the pelvis and the bottom of the ribcage.

The researchers explained that the size of the belly at this point is an indicator of the amount of fat tissue that is wrapped around the organs in the abdomen.

By examining medical records between 1994 and 2006, the researchers established that 16 per cent (1,049) of the participants had dementia an average of 36 years later.

Using statistical techniques and adjusting for age, sex, race, education, blood pressure, stroke, and other medical and demographic variables, they examined the links between midlife SAD and dementia incidence.

The results showed that:

* Participants who were overweight and had a large belly in midlife were 2.3 times more likely to develop dementia some 30 years later than those who were of normal weight and belly size.

* Participants who were obese and also had a large belly in midlife were 3.6 times more likely to develop dementia later in life compared with those of normal weight and belly size.

* Participants who were overweight or obese but did not have a large belly in midlife, had an 80 per cent increased risk of dementia.

* Having a high SAD measure, ie larger than normal abdomen, in midlife appeared to increase the risk of dementia regardless of whether the person had normal overall weight, was overweight or obese, and regardless of existing health conditions, including diabetes, stroke and cardiovascular disease.

* Being non-white, having high blood pressure, high cholesterol or diabetes, and less than a high school level of education was closely linked to higher abdominal obesity.

The study concluded that:

"Central obesity in midlife increases risk of dementia independent of diabetes and cardiovascular comorbidities. Fifty percent of adults have central obesity; therefore, mechanisms linking central obesity to dementia need to be unveiled."

Whitmer suggested that measuring midlife belly size may be a better indicator of long term disruption of metabolism that leads to dementia than using abdominal size in older people because as people age they lose muscle and bone mass and their belly becomes proportionally larger.

She said this was a disturbing finding, considering that 50 per cent of adult Americans have abdominal obesity.

"It is well known that being overweight in midlife and beyond increases risk factors for disease," said Whitmer.

"However, where one carries the weight, especially in midlife, appears to be an important predictor for dementia risk," she added.

Changes in the brain that lead to Alzheimer's can start in young to middle adulthood, as autopsies have revealed, explained Whitmer. Research has also shown that high abdominal fat in older people is linked to higher rate of brain atrophy. However, Whitmer said that:

"These findings imply that the dangerous effects of abdominal obesity on the brain may start long before the signs of dementia appear."

However, the researchers also cautioned that, as with all observational studies, you cannot say these results show that belly size drives dementia risk, the more likely explanation is that it is one of a complex set of inter-related health factors and behaviors.

The researchers called for further studies to investigate the underlying mechanisms that link belly size in midlife to risk of developing dementia later.

Dementia is not a specific disease, it is an umbrella term for a group of symptoms caused by a range of brain disorders that prevents people getting on with everyday life such as eating and getting dressed or going shopping. It impairs memory, language, ability to solve problems, and control emotions, and can change a person's personality or make them anxious or see things that aren't there.

Alzheimer's disease and stroke are two examples of diseases that can cause dementia. Drugs can slow or improve some of the symptoms but there is no cure.

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Sunday, March 23, 2008

The Far-Reaching Role of Nanominerals: From Ocean to Atmosphere to Biosphere

The ubiquity of tiny particles of minerals--mineral nanoparticles--in oceans and rivers, atmosphere and soils, and in living cells are providing scientists with new ways of understanding Earth's workings. Our planet's physical, chemical, and biological processes are influenced or driven by the properties of these minerals.

So states a team of researchers from seven universities in a paper published in this week's issue of the journal Science: "Nanominerals, Mineral Nanoparticles, and Earth Systems."

The way in which these infinitesimally small minerals influence Earth's systems is more complex than previously thought, the scientists say. Their work is funded by the National Science Foundation (NSF).

"This is an excellent summary of the relevance of natural nanoparticles in the Earth system," said Enriqueta Barrera, program director in NSF's Division of Earth Sciences. "It shows that there is much to be learned about the role of nanominerals, and points to the need for future research."

Minerals have an enormous range of physical and chemical properties due to a wide range of composition and structure, including particle size. Each mineral has a set of specific physical and chemical properties. Nanominerals, however, have one critical difference: a range of physical and chemical properties, depending on their size and shape.

"This difference changes our view of the diversity and complexity of minerals, and how they influence Earth systems," said Michael Hochella of the Virginia Polytechnic Institute and State University in Blacksburg, Va.

The role of nanominerals is far-reaching, said Hochella. Nanominerals are widely distributed throughout the atmosphere, oceans, surface and underground waters, and soils, and in most living organisms, even within proteins.

Nanoparticles play an important role in the lives of ocean-dwelling phytoplankton, for example, which remove carbon dioxide from the atmosphere. Phytoplankton growth is limited by iron availability. Iron in the ocean is composed of nanocolloids, nanominerals, and mineral nanoparticles, supplied by rivers, glaciers and deposition from the atmosphere. Nanoscale reactions resulting in the formation of phytoplankton biominerals, such as calcium carbonate, are important influences on oceanic and global carbon cycling.

On land, nanometer-scale hematite catalyzes the oxidation of manganese, resulting in the rapid formation of minerals that absorb heavy metals in water and soils. The rate of oxidation is increased when nanoparticles are present.

Conversely, harmful heavy metals may disperse widely, courtesy of nanominerals. In research at the Clark Fork River Superfund Complex in Montana, Hochella discovered a nanomineral involved in the movement of lead, arsenic, copper, and zinc through hundred of miles of Clark River drainage basin.

Nanominerals can also move radioactive substances. Research at one of the most contaminated nuclear sites in the world, a nuclear waste reprocessing plant in Mayak, Russian, has shown that plutonium travels in local groundwater, carried by mineral nanoparticles.

In the atmosphere, mineral nanoparticles impact heating and cooling. Such particles act as water droplet growth centers, which lead to cloud formation. The size and density of droplets influences solar radiation and cloud longevity, which in turn influence average global temperatures.

"The biogeochemical and ecological impact of natural and synthetic nanomaterials is one of the fastest growing areas of research, with not only vital scientific, but also large environmental, economic, and political consequences," the authors conclude.

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Genetics Research in Zebrafish has Potential to Reduce Birth Defects in Humans

By injecting a customized "genetic patch" into early stage fish embryos, researchers at Washington University School of Medicine in St. Louis were able to correct a genetic mutation so the embryos developed normally.

The research could lead to the prevention of up to one-fifth of birth defects in humans caused by genetic mutations, according to the authors.

Erik C. Madsen, first author and an M.D./Ph.D. student in the Medical Scientist Training Program at Washington University School of Medicine, made the groundbreaking discovery using a zebrafish model of Menkes disease, a rare, inherited disorder of copper metabolism caused by a mutation in the human version of the ATP7A gene. Zebrafish are vertebrates that develop similarly to humans, and their transparency allows researchers to observe embryonic development.

Children who have Menkes disease have seizures, extensive neurodegeneration in the gray matter of the brain, abnormal bone development and kinky, colorless hair. Most children with Menkes die before age 10, and treatment with copper is largely ineffective.

The research is published this month in the Proceedings of the National Academy of Sciences' advance online edition.

The development of organs in the fetus is nearly complete at a very early stage. By that time, the mutation causing Menkes disease has already affected brain and nerve development.

Madsen and Bryce Mendelsohn, also an M.D./Ph.D. student at the School of Medicine, wondered if they could prevent the Menkes-like disease in zebrafish by correcting genetic mutations that impair copper metabolism during the brief period in which organs develop. Both students work in the lab of Jonathan D. Gitlin, M.D., the Helene B. Roberson Professor of Pediatrics at the School of Medicine and director of Genetics and Genomic Medicine at St. Louis Children's Hospital.

The researchers used zebrafish with two different mutations in the ATP7A gene, resulting in a disease in the fish that has many of the same characteristics of the human Menkes disease. Madsen designed a specific therapy to correct each mutation with morpholinos, synthetic molecules that modify gene expression. The zebrafish embryos were injected with the customized therapy during the critical window of development, and the researchers found that the zebrafish hatched and grew without any discernible defects.

"This method of copper delivery suggests that the prevention of the neurodegenerative features in Menkes disease in children may be possible with therapeutic interventions that correct the genetic defect within a specific developmental window," Madsen said.

The genetic mutations Madsen and the researchers worked with are caused by splicing defects, or an interruption in genetic code. The morpholinos prevent that interruption by patching over the defect so the gene can generate its normal product.

"Consider the genetic code as a book, and someone has put in random letters or gibberish in the middle of the book," Madsen said. "To be able to read the book, you have to ignore the gibberish. If we can make cells ignore the gibberish, or the splicing defect, the fetus can develop normally."

Up to 20 percent of genetic diseases are caused by splicing defects, Madsen said, so this treatment method could potentially be used for many other genetic diseases.

"The idea is that we can modify the treatment to target a specific mutation and design molecules to alter gene function in the same way the morpholino oligonucleotides can," Gitlin said.

The work is an important step toward personalized medicine, which can tailor treatment to an individual's genetic makeup.

"Eventually we would like to know each person's genome sequence so we know what mutations each person has that may lead to disease," Gitlin said. "That way, you don't get a drug for cancer that works against any kind of cancer, you get a drug for the specific mutation that causes your cancer. That's what personalized medicine is all about."

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Thursday, March 20, 2008

Age of Stored Blood Affects Cardiac Surgery Success

A new US study found that cardiac surgery patients who received blood transfusions of blood that had been stored for 2 weeks or less had lower rates of complications and death than those who received blood that was older.

The study was the work of researchers based at the Cleveland Clinic Foundation, Cleveland, Ohio, and is published in the 20th March issue of the New England Journal of Medicine (NEJM).

In this large observational study, the investigators compared 2,872 cardiac surgery patients who received transfusion blood that had been donated within the previous 2 weeks with 3,130 cardiac surgery patients who received transfusion blood that had been donated more than 2 weeks earlier.

They found that the patients who were given older blood had a higher risk of dying in hospital than their newer blood counterparts (2.8 versus 1.7 per cent), and they were significantly more likely to need prolonged ventilation support, have kidney failure, sepsis (inflammation affecting the whole body), or multiple organ failure.

The Cleveland Clinic investigators also discovered a direct "dose response" relationship between days of storage and the chances of a combination of serious complications or adverse events. After eliminating potential confounding factors, an analysis revealed that patients who had received older blood had a significantly higher rate of combined serious adverse events than those who received newer blood.

Also, they found that patients who received newer blood had a higher chance of surviving the first year after surgery than those who received older blood 92.6 versus 89.0 per cent).

Editor in chief of Journal Watch (published by NEJM), Dr. Harlan M. Krumholz, Harold H. Hines, Jr. Professor of Medicine in the Section of Cardiovascular Medicine at the Yale University School of Medicine, said that the study raised important questions about usage of old blood for use in cardiac surgery transfusions.

The study findings are likely to be true throughout the US, said Krumholz, adding that:

"With a blood supply in constant demand, finding a solution to this problem will not be easy."

"For now, it seems reasonable to try to ensure that patients needing transfusions who are at the highest risk for adverse events receive blood that is as fresh as possible," urged Krumholz.

Previous, smaller studies have already raised questions about the shelf life of donated blood and risks to patients. Some hospitals have already brought in new procedures to minimize the use of donated blood during cardiac surgery, such as reducing anemia before surgery, using drugs to stop bleeding during and after surgery, increasing the use of "scavenged blood" where blood lost by the patient is saved and reused, and even discharging patients with a lower than normal red cell count, according to a report by the Los Angeles Times.

The paper also reports that the Cleveland Clinic researchers are planning to conduct a prospective, blinded, randomized controlled study to confirm the findings.

A number of explanations have been offered to explain why older blood raises risks to patients. One of these is that stored blood loses nitric oxide, an important agent in the delivery of oxygen to tissue cells, and another is that red blood cells become more rigid and sticky as they age, making it difficult for them to squeeze through narrow blood vessels and raising the risk of a clot.

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Alzheimer's Disease Risk increases if both Parents have Disease

In adulthood, the children of parents who have both been diagnosed with Alzheimer's disease have an increase risk of developing the disease, as reported in the March 2008 issue of the Archives of Neurology, which is one of the JAMA/Archives Journals.

Alzheimer's disease is a terminal, neurodegenerative disorder that commonly affects patients over 65 years old. "Alzheimer's disease is a common cause of dementia in the U.S. population and the leading cause of cognitive impairment in the elderly population," states the article.

Additionally, because there is a strong genetic component to the disease, the identification of genes involved in Alzheimer's disease is an important step towards detecting others at risk for the condition. "Because Alzheimer's disease is so common in the general population, it is not uncommon for both spouses to develop the disease. Offspring of two such affected individuals would presumably carry a higher burden of these Alzheimer's disease-associated genes." One such gene whose mutation has shown to be linked with Alzheimer's codes for the protein apolipoprotein E.

To this end, Suman Jayadev, M.D., of the University of Washington, Seattle, and colleagues examined the number of instances of Alzheimer's disease in the adult children of 111 families in which both parents had a clinical diagnoses of the disease. They also noted the age at which the onset of dementia occurred.

Suman Jayadev, M.D., of the University of Washington, Seattle, and colleagues studied the frequency of Alzheimer's disease in adult children of 111 families in which both parents had been clinically diagnosed with the disease. Ages at onset of dementia were also noted.

There were 297 offspring who reached adulthood. The following statistics were found, and are shown in contrast with the statistics available for the general population:

* 22.6 % developed Alzheimer's disease (estimated 6%-13% in the general population)
* 66.3 years was the average age at onset for the children
* There was a 31% increased risk for children older than 60 years
* There was a 41.8% increased risk for children older than 70 years

It is notable that at the time of the study, not all of the unaffected individuals had reached 70 years old, so this statistic may be underestimated. The authors write: "Of the 240 unaffected individuals, 189 (78.8 percent) had not yet reached age 70 years, suggesting that the incidence of Alzheimer's disease (22.6 percent) is an underestimation of the final incidence rate of Alzheimer's disease in this population."

Additional family members may present with Alzheimer's disease, but this did not increase the risk of developing the disease. It did, however, indicate a younger age of onset, for those who developed the illness. That is, children with no history of the disease beyond the parents had an older age at onset (72 years) compared with having one parents with a family history of the disease (60 years) or both parents with a family history (57 years.)

The authors conclude stating that such children in whom both parents have suffered from Alzheimer's are at a higher risk for the disease. "The role of family history and the specific genes involved in this phenomenon require a better definition," they say. "Families with a significant Alzheimer's disease history may be more likely to be referred to an Alzheimer's disease research center and, thus, the present patients may be 'enriched' for a particularly Alzheimer's disease-prone subgroup. Following these families as the offspring continue to age will provide increasingly informative data."

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Low Folate Diet Linked to Sperm Abnormality

The old adage "we are what we eat" received further support this week, and may even suggest "we are what our parents ate" when a new study by researchers in the US revealed that healthy men who have a diet low in folate have a higher risk of chromosomal abnormalities in their sperm. Chromosomal abnormalities in sperm are known to cause a range of congenital conditions such as Down syndrome and learning and development disorders.

The study is the work of scientists at the University of California (UC), Berkeley, and the Lawrence Berkeley National Laboratory, and is published in the 19th March issue of the journal Human Reproduction.

Women of childbearing age are encouraged to maintain a healthy intake of folate because it is essential for healthy fetal development, and to prevent neural tube birth defects such as spina bifida or anencephaly (severe type of brain damage). That is why folic acid is now added to bread, cereal, flour and other grain products in the US.

But this is the first study to suggest that folate intake in men may affect their children.

Researcher at UC Berkeley's School of Public Health and coordinator of the study, Suzanne Young, said:

"Recent studies have suggested that paternal diet affects sperm count and motility, which is important for conception, but this new study takes it further to say that male diet may be important for healthy offspring as well."

Young said their study was the first to examine the effects of diet on chromosomal abnormalities in sperm.

"These abnormalities would cause either miscarriages or children with genetic syndromes if the sperm fertilized an egg," explained Young.

The researchers said that about 1 to 4 per cent of healthy male sperm has an abnormal number of chromosomes, or aneuploidy. These abnormalities arise when cells divide (meiosis) in the testis, but their cause is not well understood.

If an aneuploidic sperm fertilizes a normal egg, the fetus would either miscarry or develop a chromosomal disorder, such as trisomy, where cells have three copies of each chromosome instead of the more usual two (one from each parent).

In this study the investigators looked at three chromosomes linked with common types of aneuploidy in live births: X, Y and chromosome 21. Down syndrome, for example, is caused by having an extra chromosome 21. Klinefelter syndrome, which can affect language and learning development, is caused by an extra X chromosome in boys, and boys carrying an extra Y chromosome have XYY syndrome, also linked to learning and behavioral difficulties.

The participants were 97 non-smoking men with no previous history of reproductive or fertility problems. The aged from 22 to 80 and were either still working at or had retired from a government research laboratory.

The men filled in questionnaires about their diet and supplements like multi-vitamins and other nutrients. Semen samples were taken up to a week later.

After taking out the effects of age, alcohol and medical history, the results showed that men who reported the highest folate intake had a 19 per cent lower rate of aneuploidic sperm that men with moderate folate intake, and 20 per cent lower than men with the lowest folate intake.

The analysis did not show any links between aneuploidy and other nutrients such as zinc, calcium, beta-carotene and other vitamins, said the researchers, who concluded that:

"Men with high folate intake had lower overall frequencies of several types of aneuploid sperm."

Co-principal investigator of the study, professor of epidemiology and maternal and child health at UC Berkeley's School of Public Health, Brenda Eskenazi, said:

"The emphasis related to the birth of a healthy baby has been weighted towards the health and diet of women, not just during pregnancy, but before."

"What we're finding now is that a nutritious diet, specifically folate intake, may be beneficial for men as well when it comes to producing healthy offspring," she added.

Folate, which occurs naturally in a range of foods such as liver, leafy green vegetables, peas, beans, lentils and citrus fruits, is a water soluble vitamin of the B group.

Folate is essential for DNA, RNA and protein synthesis and the development of new cells. It also helps to control homocysteine, an amino acid that has been linked to heart disease.

But before men hoping to become dads rush out to buy folic acid or start maxing out on lentils, they should take note, as the researchers themselves suggested, that this study only found a link between folate and healthy sperm, it did not establish for certain that there is a cause and effect relationship.

Study co-principal investigator and chair of the Radiation Biosciences Department at Lawrence Berkeley National Laboratory, Andrew Wyrobek, cautioned:

"We can't yet say that increasing folate in your diet will lead to healthier sperm."

"But we did come up with enough evidence to justify a larger, clinical and pharmacological trial in men to examine the causal relationships between dietary folate levels and chromosomal abnormalities in their sperm," added Wyrobek.

This information will help us set dietary folate levels that may reduce the risk of miscarriage or birth defects linked to the fathers," he said.

If further research supports these findings, the researchers suggest it might be a good idea to increase the current recommended 400 micrograms daily allowance of folate for men hoping to become dads.

See Full Article

Tuesday, March 18, 2008

Chronic Snoring remains after Surgery for Obese and African-American Children

A new study from Cincinnati Children's Hospital Medical Center reports that surgery to remove children's tonsils and adenoids to treat sleep-disordered breathing (SDB) may be successful in the short term. However, children who gain weight rapidly and African-American children tend to relapse or even worsen. The study is published in the American Journal of Respiratory and Critical Care Medicine.

Adenotonsillectomy - or removal of the tonsils and adenoids - is a surgery that is frequently performed on children. About 19 per 10,000 children in Canada, 50 per 10,000 in the U.S, and 115 per 10,000 in the Netherlands receive the surgery. Although it is often the first treatment option for SDB in children, many patients are only provided with short-term relief from SDB.

Author Raouf Amin, M.D., who directs pulmonary medicine at the hospital, writes, "The high rate of recurrence we observed in both obese and non-obese children indicates that SDB is a chronic condition."

Amin and colleagues used a sample of 40 healthy children, ages 7 to 13, whose parents and otolaryngologists agreed to treat chronic snoring with adenotonsillectomy. Thirty sex- and age-matched children who were not having the surgery were recruited as a control group. At the time of recruitment, each child received a polysomnography (PSG) - a multi-parametric test used to study sleep. PSGs were again performed at six weeks, six months, and a year after the surgery for both the treatment and control groups.

Six weeks after surgery, most of the children with SDB improved their apnea-hypopnea index (AHI) scores. However, the rate of relapse after one year had no correlation with the six-week score. Traits such as obesity, worse SDB at baseline, rapid body mass index (BMI) gain, and being African-American were associated with children who relapse.

"Most post-adenotonsillectomy outcome studies have focused on the assessment of SDB six to 16 weeks after surgery. Resolution of SDB during this window was usually interpreted as a cure for the disorder." Dr. Amin notes that, "We report[ed] for the first time the longitudinal outcome of adenotonsillectomy in healthy children, the important influence of BMI gain velocity and African-American race on recurrence of SDB."

Before surgery, about 50% of the non-obese children and 67% of the obese children had an AHI score of greater than 3. A year after surgery, 27% and 79%, respectively, had AHI score of greater than 3. These changes indicate that the surgery was significantly more effective in non-obese children after on year. Children who were obese at the baseline and, independently, children who had rapid BMI gain were more likely to relapse than those who lacked these characteristics.

Amin clarifies, "These results highlight the differential disease mechanisms between those due to obesity and those due to the rapid change in body composition associated with accelerated BMI gain." Additionally, relapse was significantly associated with children who had higher blood pressure.

"SDB appears to be a chronic disorder that is clearly linked to other medical problems. Given the rate of relapse, we advocate long-term follow up of children with SDB, monitoring of BMI gain, and reevaluation of children who demonstrate rapid BMI gain, especially those who are African-American," conclude the researchers.

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Toxin Found in Leading Organic Brands

A new study commissioned by a US consumer watchdog found that leading brands of personal care products such as shampoos, lotions and body washes that are labeled organic or 100 per cent natural contain an unidisclosed carcinogenic toxin 1,4-Dioxane. The tests were carried out by a well known, reputable third party laboratory said the consumer group.

The announcement was made by the Organic Consumers Association (OCA), a consumer group with over half a million members, in a press statement posted on their website on Friday March 14th.

The reason the toxin is present is because it is a byproduct of ethoxylation, a process that the OCA describes as "a cheap short-cut companies use to provide mildness to harsh ingredients". Ethoxylation uses the petrochemical Ethylene Oxide and produces 1,4-Dioxane as a byproduct. OCA reports that 1,4-Dioxane is in the list of known cancer causing chemicals that is published every year by the Governor of California under the state's proposition 65 (the Safe Drinking Water and Toxic Enforcement Act of 1986).

The OCA said that 1,4-Dioxane has "no place" in "natural" or "organic" branded personal care products. According to the group, the California Environmental Protection Agency (EPA) classes 1,4-Dioxane as a leading contaminant of groundwater and suspects it to be a kidney toxicant, neurotoxicant and respiratory toxicant.

The toxin is often present in conventional personal care products, said the OCA, as shown by other research, but the objection here is that it was found in so called "natural" and "organic" products, none of which are certified under the US Department of Agriculture's National Organic Program. Some of the leading brands found to contain 1,4-Dioxane include:

* JASON Pure Natural & Organic.
* Giovanni Organic Cosmetics.
* Kiss My Face.
* Nature's Gate Organics.

The OCA is calling for all so called organic brands that include ethoxylate ingredients or use any petrochemicals in their ingredients to drop their claim to being organic and show this on their labeling and branding.

OCA's Executive Director, Ronnie Cummins, told the press:

"The practice of ethoxylating ingredients or using other petroleum compounds must end for natural personal care, and is that much more outrageous in so-called organics brand products."

At a time when Americans are trying to wean themselves off petroleum-based ingredients, it is "self-defeating that we are literally bathing ourselves and our children in toxic petroleum compounds," said David Steinman, environmental health consumer advocate and author of The Safe Shopper's Bible.

"But consumers should also take heart in the emergence of a growing number of companies who've received the message and who are seeking to completely avoid petrochemicals in their cosmetic and personal care products," added Steinman.

Steinman recommended consumers wishing to buy organic products check that they contain ingredients certified under the USDA National Organic Program.

The OCA said all the USDA Certified brands tested in their study were 1,4-Dioxane-free, including Dr. Bronner's, Sensibility Soaps (Nourish), and Terressentials.

They also found that all German Natural BDIH certified brands they tested were also free of the toxin, including Aubrey Organics and Dr. Hauschka.

The OCA commented that unfortunately most personal care products sold in health food stores that claim to be "organic" contain ingredients that are not certified under the USDA National Organic Program. They contain only "cheap water extracts of organic herbs and maybe a few other token organic ingredients for organic veneer," said the OCA in their press statement.

The main ingredient in such products, said the association, is conventional manmade cleansers and conditioning chemicals, made partly using petrochemicals.

Market surveys show that consumers are prepared to pay more for products branded as "natural" or "organic", said the OCA. But they are not expecting them to contain petrochemical-modified ingredients or toxin like 1,4-Dioxane.

A clue to the presence of ethoxylation byproducts like 1,4-Dioxane is when the ingredient list contains names like "myreth," "oleth," "laureth," "ceteareth," any other "eth," and also names like "PEG," "polyethylene," "polyethylene glycol," "polyoxyethylene," or "oxynol", said the consumer group.

Cummins urged consumers to be more aware, because:

"When it comes to misbranding organic personal care products in the US, it's almost complete anarchy and buyer beware unless the product is certified under the USDA National Organic Program."

Government regulators don't agree on whether trace levels of 1,4-dioxane in personal care and household products are toxic. Personal care products are regulated by the US Food and Drug Administration, which maintains that the amounts typically found in them are not hazardous to consumers, said a report in the Washington Post.

According to the Post, the OCA gets 90 per cent of its funding from private individuals and the rest is from grants and donations from companies, including two that make personal care products. The OCA tested one of these, Dr. Bronner's Magic Soaps (which was found not to contain 1,4-dioxane).

Spokespeople for some of the companies listed by the OCA as having products containing the toxin were surprised by these results and said they would be investigating further.

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Friday, March 14, 2008

Smart and Personal Health Search Engine Offered By Insurer

American health insurer and benefits provider Aetna has launched a "smart" web-based search engine that uses personal medical history and other background information to make it easier for their members to research and find health information that is relevant and useful to them personally, such as drugs and treatments available for their particular conditions, estimated healthcare costs and local specialists who participate in their health plan.

The company, who has teamed up with health information technology company Healthline Networks to provide the new SmartSource service, said it wants to help its members to manage their own healthcare.

The system has already been piloted among Aetna's 35,000 employees and will gradually be rolled out to its members starting in August this year.

Meg McCabe, Aetna's vice president of medical and eHealth products, said in a press statement yesterday that the company wants to be an industry leader in giving personalized health information to its members, and that the new service:

"Pulls information from a variety of Aetna web resources to intelligently organize search results based on a member's insurance plan, zip code, and overall health, thereby helping members to become more engaged in their health care decisions."

The technical challenge of providing relevant and useful health information in an age of information overload (you can spend hours researching a particular illness on the internet these days and still not find anything useful to your particular case) is the bringing together of a person's medical history, local information about where they live, and other personal data, and then use this to probe the vast array of medical knowledge that is now available in digital form.

By teaming up with Healthline, Aetna claims that SmartSource meets this challenge, because it takes into account personal information such as the user's gender, age, zip code, employer and health care plan, as well as information stored in their personal health record (PHR). This customized information, or member profile, together with a suite of online tools, acts like an intelligent search engine that probes a unique collection of resources, including:

* Aetna InteliHealth (developed with Harvard Medical School and Columbia School of Dental Medicine): an online consumer health information website that contains user friendly health resources.

* Aetna DocFind: a directory where the user can find local physicians, hospitals, specialists, dentists, pharmacies, eye care centers and other health facilities who participate in their health plan.

* Estimate the Cost of Care: helps users work out average costs of medical and dental procedures, prescription drugs, office visits and medical tests based on their zip code.

* Healthwise Knowledgebase: this is like a decision support resource that helps users make informed choices about treatment options according to their own needs and preferences.

Concerns have been voiced by various interest groups that using personal data in this way opens up the possibility that it will be used against the individual. For example, it could be used to reject applications or raise premiums.

McCabe told the New York Times it would not be a good business decision to use this information to raise premiums or reject applications. She said the company would also ensure that the "information is secured and shared, based on the member's purposes", and there was a need to "develop a relationship with our members based on trust".

In its news release, Aetna describes itself as serving "approximately 36.7 million people with information and resources", but it is not clear how many of these will be offered the new service. Media reports quote figures of up to 16.8 million members.

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Flu Outbreak closes Hong Kong Schools

Outbreaks of influenza-like illness (ILI) in over 20 schools that are linked to the deaths of three children have caused the government to shut all schools in Hong Kong for two weeks, keeping half a million children away, reported Reuters.

According to information from the Center for Health Protection (CHP) of the Department of Health (DH) in Hong Kong, up to yesterday, Wednesday 12th March, health officials had received reports of 184 ILI cases in outbreaks affecting 23 schools. Officials from the CHP have visited all the schools and given appropriate advice, according to a press release on the CHP website.

ILI can be caused by influenza or other respiratory viruses, said the CHP, who will be giving out public information on seasonal influenza today. The center has also set up a hotline.

Three children, aged 2, 3 and 7 have died in the last two weeks, the older two had seasonal flu and the cause of illness in the youngest is still undetermined, said Reuters.

The government has closed the schools as a precaution because the number of young children getting the flu seems to be higher this year, Health Secretary York Chow told a press conference. The second reason was the number of deaths so far.

A fourth death was reported to the CHP yesterday, that of a 21 month old boy who developed fever and cough on February 22nd, was admitted to Alice Ho Miu Ling Nethersole Hospital the next day, and was transferred to the Intensive Care Unit (ICU) of the Prince of Wales Hospital after developing generalized seizure. He died on 22nd February. A sample taken from the boy tested negative for influenza types A and B, and there is no evidence that he had influenza, said the CHP. The case is still being investigated.

Another 3 year old boy is in a stable condition, according to the CHP who received an update on his condition yesterday, when he was admitted to the ICU at Princess Margaret Hospital with symptoms of persistent fever, cough and shortness of breath. A sample taken from him has tested positive for influenza type A (H1N1).

Health officials have visited the kindergarten the boy attended, where so far no ILI outbreak has been reported.

Giving out further information on the 7 year old boy who died in Tuen Mun Hospital after being admitted with respiratory and neurological symptoms, the CHP said a sample taken from him has tested positive for influenza A (H1N1), and the case has been referred to the Coroner's Court.

While it is natural for parents to be concerned, experts have told the press there is no cause for panic and that every few years or so there is a higher than usual incidence of flu outbreaks.

In the meantime, the Hong Kong Department of Health suggests people boost their immune system against the flu by "having a proper diet, regular exercise, and adequate rests, reducing stress and avoiding smoking". They also urge people to "maintain good personal and environmental hygiene."

Hong Kong's hotline for seasonal flu information is on telephone number 2125-1133, open Monday to Friday, 9 am to 6 pm (provided by Center for Health Protection, CHP).

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Modeling Flu Pandemics may help prevent them

An article published in the Early Edition of the Proceedings of the National Academy of Sciences in the United States of America suggests that we can reduce the likelihood of a pandemic influenza outbreak in the United States by quickly implementing social-distancing measures alongside antiviral treatment and prophylaxis (preventive measures) until a vaccine becomes accessible.

The study was conducted by three teams of researchers in the US and England who worked closely with federal officials. The teams and an informatics group - part of the Models of Infectious Disease Agent Study (MIDAS) Network, funded by the National Institute of General Medical Sciences (NIGMS) - set out to study several intervention combinations to aid the planning process for a national pandemic.

The authors, led by M. Elizabeth Halloran, M.D., D.Sc. and Ira M. Longini Jr., Ph.D., (Fred Hutchinson Cancer Research Center and professors of biostatistics at the University of Washington), investigated the natural course of infectious diseases by using sophisticated mathematical and statistical models. Longini notes that to make sure the results were robust, the federal government wanted three groups to be working on the same problem. The data, says Longini, "would be used to inform national pandemic planning," and thus they got the highest level of input.

Since a flu vaccine was not available when the researchers began the study, they focused on the effectiveness of using antiviral and social-distancing interventions (e.g. closing schools) together in order to prevent an influenza pandemic. According to earlier studies, models have shown that an available vaccine, even if low-efficacy, would be helpful in reducing the speed of a pandemic.

Halloran notes: "The good news was that all three of the disease-modeling groups involved in the study found that an outbreak of pandemic flu similar to the pandemic of 1918 could be mitigated if these measures were implemented quickly."

One research team consisted of Halloran, Longini, a computer scientist Shufu Xu, and others at the Los Alamos National Laboratories. Researchers at Imperial College in London and the University of Pittsburgh comprised a second group, and a third group included researchers at Virginia Bioinformatics Institute at Virginia Tech in Blacksburg, Va.

Each research team used separate but similar computer models. They calculated how influenza would disperse in a city of about 8.6 million people, such as Chicago, IL. The models assumed that residents of the virtual community interacted in households, schools, workplaces, and the community, just as they usually do. The models all assumed attack-rate patterns that were analogous to US flu pandemics that have occurred in the past.

To take into account real-world unpredictability and several other characteristics of the disease and the population, Halloran and colleagues use stochastic modeling when predicting the spread of influenza. The first step in building pandemic models requires researchers to come up with various assumptions about the ways in which people interact and how the virus spreads. They can then introduce intervention strategies to the model in order to test how effective they are.

Two categories of intervention were assessed:

1. Medical intervention: surveillance used to identify cases, and antiviral agents are used to treat patients and prevent the disease among close contacts
2. Non-pharmaceutical: social distancing - closing schools, voluntary quarantine, restricting travel restrictions

The models allowed researchers to analyze how combinations of targeted antiviral treatment, prophylaxis, and social-distancing strategies affect five intervention scenarios of varying stringency and disease transmissibility levels. Transmissibility of the virus is calculated as the average number of secondary cases that each primary case infects at the beginning of the epidemic, and how rapidly these cases arise. These data aid the researchers in estimating the likelihood that an epidemic will become a pandemic.

The three computer simulations predict about 47 to 60 percent of the population will have symptomatic influenza if there is no intervention.

In the least-stringent scenario, interventions were implemented after 1 percent of the population had developed symptomatic influenza, schools were closed, 60 percent of clinical influenza patients received antivirals and their contacts received prophylaxis, 30 percent complied with quarantine, and 60 percent complied with social-distancing measures.

The three computer-modeling groups predict an 83 to 94 percent reduction in cases of influenza using combined intervention strategies at a lower transmissibility of the virus, even in the least-stringent scenario.

Longini maintains that the researchers "ran this simulation with the assumption that the pandemic was as virulent and lethal as the 1918 pandemic." He adds: "Even when modeling the situation of pandemic flu, with a modest compliance range in social-distancing measures, and modest ability to identify and treat and prophylax with antivirals, the interventions were similarly - though not identically - effective in all three models."

The researchers believe that the policy implications of these findings are noteworthy. "If one could achieve these levels of compliance, ascertainment and social distancing, then there is a possibility of considerably mitigating a pandemic until a vaccine was available." They caution, though, that the levels of disease ascertainment and compliance that were entered into the models may not be realistic.

"These models, which are built from the best available data and with the best tools, contribute greatly to our understanding of how a pandemic could spread and what measures might protect the public's health," said Jeremy M. Berg, Ph.D., director of the NIGMS, which supports the MIDAS program. "But they are not our only resource; field work and experimental studies remain critical and will enhance the quality and reliability of these and other models," conclude the authors.

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Tuesday, March 11, 2008

Macular Degeneration more than Doubles Heart Attack and Stroke Risk

Age related macular degeneration (AMD) doubles the risk of dying from a heart attack, according to research released on February 28, 2008 in the British Journal of Opthalmology.

AMD is a progressive eye diseases which affects the center of the retina, known as the macula, at the back of the eye. This portion of the eye is most specialized for fine, central vision tasks, including reading or driving. It is most common among the elderly, and in developed countries it is a major cause of untreatable blindness.

An Australian team of researchers at the University of Sydney analyzed over 3600 people aged 49 years or more between 1992 and 1994. Five years later, a follow up was performed on 2335 of these people; after ten years, 1952 were examined again. The analysis included physical examinations and photographs of the retina itself -- the causes of death of participants during the study was also noted based on the national register.

Of the population under age 75 who participated in the study, early presentation of AMD was linked to a double in the risk of death from heart attack or stroke within a decade. The late stage disease was associated with a five fold increase in death from heart attack and ten time the risk of death from stroke.

As there are some concerns that current treatments for AMD could elevate stroke risk, these results have extremely important implications for the treatment of this disease in the elderly.

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PSA less useful in Prostate Screening now Biopsies have improved

Researchers in the US suggest that the prostate specific antigen (PSA) test is now less useful in prostate cancer screening, and may have lost some of its predictive value, because biopsy techniques have improved in the ten years or so since the research that justified the use of PSA as a diagnostic tool was done.

The study is the work of Drs. Douglas Scherr and Michael Schwartz, and colleagues at the New York Presbyterian Hospital of the Weill Medical College of Cornell University, based in New York City, and is published in the 10 March online issue of the journal Cancer.

The correlation between PSA levels and positive prostate biopsy results was established at a time when biopsy patterns were not as they are today. Much of the data to justify the PSA test as a useful diagnostic tool was generated in the 1990s. Today, more biopsies are taken, and more samples are taken from each patient.

Scherr, Schwartz and colleagues examined data on 1,607 patients whose prostate biopsies were carried out at their hospital between 1993 and 2005 and grouped them according to when they received their biopsies: 1993-1997, 1998-2001, and 2002-2005. They then looked for how patterns of practice, and correlation between PSA and biopsy results shifted with time.

Using the number of biopsies performed, the number that were positive, the number of biopsy samples taken, the age of the patient, the most recent PSA before the biopsy and the volume of the prostate, the researchers assessed the potential links between PSA levels and the rate of positive biopsies.

They found that:

* The number of biopsies performed, the percentage of positive biopsies, and patient age did not change significantly over time.

* But there was more frequent use of PSA level 2.5 to 3.99 ng/ml as a biopsy indication (ie tendency toward lower PSA threshold).

* And there was an increase in the median number of core samples taken at the time of the biopsy.

* In men with a normal digital rectal exam, there was a moderate correlation between PSA level and positive biopsy rate between 1993 and 1997, but not after that.

* Fewer biopsies were performed for the indication of a suspicious digital rectal exam.

* The positive biopsy rate in men with PSA levels between 2.0 and 3.99 ng/ml was the same or higher than that for men with higher PSA levels.

* Multivariate analysis showed that PSA was not a significant predictor of biopsy result in men with a normal digital rectal exam.

The researchers concluded that:

"Early in the PSA era, the predictive power of PSA depended on multiple factors: high prevalence of disease, higher prevalence of high-grade disease, and low likelihood of prostate cancer diagnosis in men with low PSA."

But today, because of the "culling effect" of more frequent biopsies and shifts in biopsy patterns, they said that:

"The correlation between PSA and biopsy result is lost in men with normal DRE [digital rectal exam]," and that "diagnosing a higher proportion of tumors in men with a PSA between 2.0 and 4.0 ng/mL has negatively influenced the predictive value of PSA for cancer detection".

According to the American Cancer Society, the PSA level normally goes above 4 ng/ml when cancer is present, but around 15 per cent of men with a PSA under 4 will have prostate cancer.

Scherr told WebMD that whether the PSA level was as low as 2.5 or as high as 10, the chance of finding cancer was about the same in the men who had biopsies, so the usefulness of using PSA to find the men who need biopsies has been lost, he said, especially given that the prostate cancers they are finding are also smaller.

The researchers said there was an urgent need for new blood or urinary markers to predict who should have a prostate biopsy, because apart from family history or signs from previous biopsy results, there is little help available to give doctors a clue as to who should be referred for a prostate biopsy.

Dr. Robert Smith, Director of Screening at the American Cancer Society told WebMD that while PSA is an imperfect test, it "happens to be the best one we have at the moment", and that:

"Because of the uncertainties, leading cancer organizations, including ACS, recommend that men discuss the pros and cons of this test with their doctors."

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Hope for Crohn's Patients with Fistulas found in HUMIRA/Adalimumab

At the recent European Crohn's and Colitis Organization (ECCO) annual meeting in Lyon, France, Abbott Laboratories announced that HUMIRA (Adalimumab) is successful in the treatment of fistulas in susceptible Crohn's patients.

Crohn's Disease (CD) is a gastrointestinal disorder which is indicated by chronic inflammation of the wall of the digestive tract. The disease involves constant cycles of flare-ups and remission throughout the life of the patient, and without proper treatment, must be addressed surgically. It is considered an inflammatory bowel disease (IBD), similar to ulcerative colitis. Up to 43% of Crohn's disease patients develop painful and embarrassing fistulas, which are tunnels that connect affected organs to surrounding tissues such as the bladder, vagina, or skin. These are difficult to treat, can cause fecal discharge in abnormal locations, and can thus lead to incontinence, infections, and complications that will necessitate surgery.

HUMIRA, or Adalimumab works by binding Tumor Necrosis Factor α (TNF-α), an important part of the immune response pathway -- in this way it is related to infliximab and other TNF-α blockers. It has been approved in several countries for treatment of many autoimmune diseases including CD, psoriasis, and certain types of arthritis. Abbott Labs is also studying HUMIRA in pediatric CD.

The fistula study was based on data taken in the CHARM study. In a subanalysis, it was shown that fistula healing was improved with treatment with HUMIRA:

* 60% of patients experienced fistula healing at one year of treatment
* 76% of patients who experienced healing at one year sustained the healing through two years
* 71% of patients demonstrated a 50% reduction in the number of draining fistulas after two years of treatment

Over a two year term, fistula patients had a higher quality of life because the CD was in remission, defined as scoring greater than 170 points on the Inflammatory Bowel Disease Questionnaire (IBDQ): after 1 year, 54% of patients and after 2 years, 60% of patients achieved this score.

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Saturday, March 8, 2008

New Colorectal Cancer Screening Guidelines Focus on Prevention

A consortium of cancer groups has published new guidelines for screening colorectal cancer, which for the first time focus on prevention and early detection.

The guidelines are published online in CA, A Cancer Journal for Clinicians and were issued by the American Cancer Society Colorectal Cancer Advisory Group, the US Multi-Society Task Force, and the American College of Radiology Colon Cancer Committee.

The new guidelines add two new screening tests: stool DNA and CT or "virtual" colonography to the existing list that already includes options such as the more familiar colonoscopy and double contrast barium enema.

The new recommendations are also more specific about the pros and cons of the different options, for instance some of the more invasive tests are more likely to prevent cancer because they find pre-cancerous polyps which can be removed before the disease develops. Other tests are less likely to find pre-cancerous growths, but still detect most cancers, said the American Cancer Society (ACS) in a press statement.

The aim of the guidelines is to help doctors and patients make better decisions about colon cancer screening.

They are written for people over 50 with an average risk of developing colon cancer and anyone with a higher than normal risk should have more intensive screening, said the ACS.

Colorectal Cancer (CRC, also shortened to colon cancer) is the third most common cancer diagnosed among American men and women and the second leading cause of cancer death in the US. The ACS said that although the rates of new cases is going down, there would be even fewer if more people who should be screened actually did.

All types of screening have the potential to find early stage cancer, but only some can find pre-cancerous growths, which are easier to treat.

The guidelines only include tests described in scientific literature as being able to detect at least 50 per cent of cancers.

The figures show that where colon cancer is stopped before it has spread to lymph nodes and other organs, 90 per cent of patients survive more than 5 years after diagnosis. This compares with a 10 per cent rate of survival for 5 years or more among patients whose cancer has spread.

The guidelines recommend that where tests are available, and patients are willing, doctors should encourage testing for both polyps and cancer.

Dr. Durado Brooks, Director of Prostate and Colorectal Cancer at the ACS said this was the first time such guidelines have stated a preference for one type of test over another, explaining that:

"In the past we've created a list [of options] and left it up to providers and patients to decide what would work best for them."

But now, it is becoming clearer with research that some tests are more likely to help prevent cancer, he said, "and for the first time our guidelines state that colorectal cancer prevention should be the primary goal of screening".

Also, while the guidelines suggest some tests are better than others, the main thing is to get tested, said Brooks, explaining that:

"The best test is the test the patients can get and will take, but patients should be aware that there is a greater potential for certain types of tests to prevent cancer."

The new guidelines give 4 tests that give the best chance of finding both polyps and cancer:

1. Flexible sigmoidoscopy (recommended every 5 years).
2. Colonoscopy (every 10 years).
3. Double contrast barium enema (every 5 years).
4. CT (computer tomography or "virtual") colonography (every 5 years).

In sigmoidoscopy and colonoscopy tests, a camera on the end of a flexible tube is inserted in the patient's rectum and colon to see if there are any polyps or cancers. Any polyps found can be removed during the procedure. A colonoscopy searches the whole length of the colon, whereas a sigmoidoscopy only looks at the one third nearest the rectum, so if the latter finds anything it is normally followed by a full colonoscopy to look at the unexamined areas.

In the double contrast barium enema test, barium sulfate (a liquid that looks and feels like watery chalk) and air is introduced into the colon via a catheter. X-rays are then taken to see what shape the barium, which is opaque to X-ray, takes and if there are any polyps or cancerous growths. If these are found, then a colonoscopy is usually recommended to confirm the diagnosis.

CT colonography involves taking CT (computed tomography) images (the patient goes into a large circular machine) of the colon while it is filled with air. If this finds polyps or cancerous growths it is usually followed by a colonoscopy to make sure.

The guidelines also specify three types of stool test that look for cancer, rather than polyps. These are:

1. Guaiac-based fecal occult blood testing (gFOBT; recommended every year).
2. Fecal immunochemical test (FIT; every year).
3. Stool DNA (frequency not specified).

The first two tests, gFOBT and FIT, look for blood in the stool, which can indicate cancer or it could be a large polyp that has started bleeding.

The third test, stool DNA, is quite new. It looks at the DNA of cells shed via the stool to see if any known DNA signatures of cancer are present. It's still a new technique and there is not enough information on how frequently the test should be carried out. The ACS warns that it may not pick up all DNA cancer signatures.

Again, a positive result in any of these three tests would normally be followed up with a colonoscopy.

For the first time, the guidelines also deal with quality of tests. Brooks explained this was necessary because there was a "fair amount of testing going on in the marketplace that is of such poor quality that in many ways you're doing patients a disservice".

One example is the FOBT test. If this shows a positive or suspicious result, good practice recommends the patient is referred for a colonoscopy, but this sometimes does not happen. Brooks said that is a "mistake", and carries the risk that "cancers are going to be missed". Hence the guidelines "go to great lengths to spell out the quality issues that need to be in place for any type of test," he explained.

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Wednesday, March 5, 2008

Urinary Catheterization

Urinary or Urethral catheterization is a process in which a urinary catheter (such as a Foley catheter) is either inserted through a female patient's urinary tract into their bladder or attached to a male patient's penis. A balloon located at the end of the catheter is usually inflated with sterile water to prevent the catheter from slipping out. In this manner, the patient's urine is collected and contained for various medical purposes. The procedure of catheterization will usually be done by a clinician, often a nurse, although self-catheterization is possible as well.

Urinary catheterization is a routine medical procedure that has both diagnostic and therapeutic purposes.

Types of Catheterization

Catheters come in a large variety of sizes; materials (latex, silicone, PVC, or Teflon); and types (Foley catheter, straight catheter, or coude tip catheter). In the case of internal catheters, those inserted into the urethra, the smallest size is usually recommended, although a larger size is sometimes needed to control leakage of urine around the catheter. A large size can also become necessary when the urine is thick, bloody or contains large amounts of sediment. Larger internal catheters, however, are more likely to cause damage to the urethra. Some people have developed allergies or sensitivities to latex after long-term latex catheter use. In such cases, silicone or Teflon types should be used.

Proper catheter use can also often be determined by the length of time for which the process is necessary: long-term (often called indwelling) or short-term use.

Sex Differences

In males, the catheter tube is inserted into the urinary tract through the penis. A condom catheter can also be used. In females, the catheter is inserted into the urethral meatus, after a cleansing using povidone-iodine. The procedure can be complicated in females due to varying layouts of the genitalia (due to age, obesity, Female genital cutting, childbirth, or other factors), but a good clinician should rely on anatomical landmarks and patience when dealing with such a patient.

Indication

Diagnostic

o Collection of uncontaminated urine specimen
o Monitoring of urine output
o Imaging of the urinary tract

Therapeutic

o Acute urinary retention (eg, benign prostatic hypertrophy, blood clots)
o Chronic obstruction that causes hydronephrosis
o Initiation of continuous bladder irrigation
o Intermittent decompression for neurogenic bladder
o Hygienic care of bedridden patients

Contraindication

Urinary catheterization is contraindicated in the presence of traumatic injury to the lower urinary tract (eg, urethral tear). This condition may be suspected in male patients with a pelvic or straddle-type injury. Signs that increase suspicion for injury are a high-riding or boggy prostate, perineal hematoma, or blood at the meatus. When any of these findings are present in the setting of concerning trauma, a retrograde urethrogram should be performed to rule out a urethral tear prior to placing a catheter into the bladder.

Anesthesia

Topical anesthesia is administered with lidocaine gel 2%. Many facilities have a preloaded syringe with an opening appropriate for insertion into the meatus available either separately or in the catheter kit. To instill, hold the penis firmly and extended, place the tip of the syringe in the meatus, and apply gentle but continuous pressure on the plunger.

Equipment

Commercial single-use urethral catheterization tray

o Povidone iodine
o Sterile cotton balls
o Water-soluble lubrication gel
o Sterile drapes
o Sterile gloves
o Urethral catheter
o Prefilled 10-mL saline syringe
o Urinometer connected to a collection bag

Sterile anesthetic lubricant (eg, lidocaine gel 2%) with a blunt tip urethral applicator or a plastic syringe (5-10 mL)

Positioning

Place the patient supine, in the frogleg position, with knees flexed.

Technique

· Explain the procedure, benefits, risks, complications, and alternatives to the patient or the patient's representative.

· Position the patient supine, in bed, and uncover the genitalia.

· Open the catheter tray and place it on the gurney in between the patient's legs; use the sterile package as an extended sterile field. Open the iodine/chlorhexidine preparatory solution and pour it onto the sterile cotton balls. Open a sterile lidocaine 2% lubricant with applicator or a 10-mL syringe and sterile 2% lidocaine gel and place them on the sterile field.

· Wear sterile gloves and use the nondominant hand to hold the penis and retract the foreskin (if present). This hand is the nonsterile hand and holds the penis throughout the procedure.

· Use the sterile hand and sterile forceps to prep the urethra and glans in circular motions with at least 3 different cotton balls. Use the sterile drapes that are provided with the catheter tray to create a sterile field around the penis.

· Using a syringe with no needle, instill 5-10 mL of lidocaine gel 2% into the urethra. Place a finger on the meatus to help prevent spillage of the anesthetic lubricant. Allow 2-3 minutes before proceeding with the urethral catheterization.

· Hold the catheter with the sterile hand or leave it in the sterile field to remove the cover. Apply a generous amount of the nonanesthetic lubricant that is provided with the catheter tray to the catheter.

· While holding the penis at approximately 90º to the gurney and stretching it upward to straighten out the penile urethra, slowly and gently introduce the catheter into the urethra. Continue to advance the catheter until the proximal Y-shaped ports are at the meatus.

· Wait for urine to drain from the larger port to ensure that the distal end of the catheter is in the urethra. The lubricant jelly–filled distal catheter openings may delay urine return. If no spontaneous return of urine occurs, try attaching a 60-mL syringe to aspirate urine. If urine return is still not visible, withdraw the catheter and reattempt the procedure (preferably after using ultrasonography to verify the presence of urine in the bladder).

· After visualization of urine return (and while the proximal ports are at the level of the meatus), inflate the distal balloon by injecting 5-10 mL of 0.9% NaCl (normal saline) through the cuff inflation port. Inflation of the balloon inside the urethra results in severe pain, gross hematuria, and, possibly, urethral tear.

· Gently withdraw the catheter from the urethra until resistance is met. Secure the catheter to the patient's thigh with a wide tape. Creating a gutter to elevate the catheter from the thigh may increase the patient's comfort. If the patient is uncircumcised, make sure to reduce the foreskin, as failure to do so can cause paraphimosis.

Pearls

Insertion of a Coudé catheter: The Coudé catheter, which has a stiffer and pointed tip, was designed to overcome urethral obstruction that a more flexible catheter cannot negotiate (eg, patients with benign prostatic hypertrophy). To place a Coudé catheter, follow the procedure described above. The elbow on the tip of the catheter should face anteriorly to allow the small rounded ball on the tip of the catheter to negotiate the urogenital diaphragm.

Perineal pressure assistance: The distal tip of the catheter might become caught in the posterior fold between the urethra and the urogenital diaphragm. An assistant can apply upward pressure to the perineum while the catheter is advanced to direct the catheter tip upward through the urogenital diaphragm.

Complications

-Infections

o Urethritis
o Cystitis
o Pyelonephritis
o Transient bacteremia

-Paraphimosis, caused by failure to reduce the foreskin after catheterization

-Creation of false passages

-Urethral strictures

-Urethral perforation

-Bleeding

Open Section

* Prophylactic antibiotics are recommended for patients with prosthetic heart valves, artificial urethral sphincters, or penile implants.

* Catheter types and sizes

o Adults: Foley (16-18 F)
o Adults with obstruction at the prostate: Coudé (18 F)
o Children: Foley (5-12 F)
o Infants younger than 6 months: Feeding tube (5 F) with tape

Reference

http://www.emedicine.com
Served as Primary source.

http://www.wikipedia.org
Served as Secondary source.

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Black Tea may help fight Type 2 Diabetes

Scientists in Scotland have unexpectedly discovered that black tea may help to combat type 2 diabetes. The discovery is at the laboratory stage and the research team is hoping to get funding to investigate further and replicate their findings in clinical settings.

The discovery is the work of Dr. Graham Rena and his team at the Neurosciences Institute of the University of Dundee, and is published in the journal Aging Cell.

Although green tea has for some time been regarded as a health giving food, not many have thought the same about black tea.

Rena and colleagues are researching compounds that have the potential to replace insulin in type 2 diabetes, the type of diabetes where the body's cells have become resistant to insulin, an essential regulator of blood sugar.

Working with fellow researchers from the Scottish Crop Research Institute, Rena and his team found that the black tea compounds theaflavins and thearubigins behaved like insulin.

Rena explained:

"What we have found is that these constituents can mimic insulin action on proteins known as FOXOs."

FOXOs (short for forkhead transcription factor family O) are known to regulate links between diet and health in many organisms, including mice, worms and fruit flies, said Rena. He said:

"The task now is to see whether we can translate these findings into something useful for human health."

Rena pointed out that the Dundee study is just the first step, and if they can find substances that restore the regulation of the FOXO proteins in people with type 2 diabetes, then these could be used to help them overcome some of the serious health problems that this diagnosis brings.

Rena warned that people should not rush out and start drinking lots of black tea in the hope that it will cure their diabetes. A lot more research is needed:

"We are still some way from this leading to new treatments or dietary advice. Our research into tea compounds is at a preclinical, experimental stage and people with diabetes should continue to take their medicines as directed by their doctor," said Rena.

But, he said there is definitely something worth exploring in these natural substances in black tea, and they may have health giving benefits, not just to people with diabetes, he added.

Rena is hoping to get further funding to enable his team to look more closely into how the tea compounds behave like insulin, and also to discover if the effects shown in the laboratory can be replicated in clinical settings.

Diabetes is the fastest growing epidemic in the world.

More than 350 million people worldwide will have the disease by 2030, according to World Health Organization (WHO) estimates.

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Monday, March 3, 2008

Discovery of 'Rain-Making' Bacteria could have Implications for Climate

Brent Christner, LSU professor of biological sciences, in partnership with colleagues in Montana and France, recently found evidence that rain-making bacteria are widely distributed in the atmosphere. These biological particles could factor heavily into the precipitation cycle, affecting climate, agricultural productivity and even global warming. Christner and his colleagues will publish their results in the prestigious journal Science on Feb. 29.

Christner's team examined precipitation from global locations and demonstrated that the most active ice nuclei - a substrate that enhances the formation of ice - are biological in origin. This is important because the formation of ice in clouds is required for snow and most rainfall. Dust and soot particles can serve as ice nuclei, but biological ice nuclei are capable of catalyzing freezing at much warmer temperatures. If present in clouds, biological ice nuclei may affect the processes that trigger precipitation.

The concept of rain-making bacteria isn't far-fetched. Cloud seeding with silver iodide or dry ice has been done for more than 60 years. Many ski resorts use a commercially available freeze-dried preparation of ice-nucleating bacteria to make snow when the temperature is just a few degrees below freezing.

"My colleague David Sands from Montana State University proposed the concept of 'bioprecipitation' over 25 years ago and few scientists took it seriously, but evidence is beginning to accumulate that supports this idea," said Christner.

But, what makes this research more complicated is that most known ice-nucleating bacteria are plant pathogens. These pathogens, which are basically germs, can cause freezing injury in plants, resulting in devastating economic effects on agricultural crop yields.

"As is often the case with bacterial pathogens, other phases of their life cycle are frequently ignored because of the focused interest in their role in plant or animal health," said Christner. "Transport through the atmosphere is a very efficient dissemination strategy, so the ability of a pathogen to affect its precipitation from the atmosphere would be advantageous in finding new hosts."

It is possible that the atmosphere represents one facet of the infection cycle, whereby the bacteria infects a plant, multiplies, is aerosolized into the atmosphere and then delivered to a new plant through atmospheric precipitation.

"The role that biological particles play in atmospheric processes has been largely overlooked. However, we have found biological ice nuclei in precipitation samples from Antarctica to Louisiana - they're ubiquitous. Our results provide an impetus for atmospheric scientists to start thinking about the role these particles play in precipitation," said Christner. "This work is truly multi-disciplinary, bridging the disciplines of ecology, microbiology, plant pathology and climatology. It represents a completely new avenue of research and clearly demonstrates that we are just beginning to understand the intricate interplay between the planet's climate and biosphere."

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Saturday, March 1, 2008

Urinary Catheterization (Male)

Researched and Presented by Anthony
Description: Male Urinary Catheterization.
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Urinary catheterization may be performed as either a therapeutic or a diagnostic procedure. Therapeutically, catheters may be placed to decompress the bladder in patients with acute or chronic urinary retention. In addition, catheters may be placed to facilitate bladder irrigation in patients with gross hematuria. Diagnostically, urinary catheters may be placed to obtain an uncontaminated urine sample for microbiologic testing, to measure urinary output in critically ill patients or during surgical procedures, or to measure post-void residuals.