UN Applauds Sri Lanaka Govt.’s Steps to Safeguard Childen’s Rights

UN Secretary General Ban ki-Moon applauded the Sri Lankan Government’s creation in April 2007 of a special task force on children and armed conflict, and called on authorities to take measures to prevent armed groups’ abduction and recruitment of children as soldiers and to secure the release of current child soldiers. Read more

Teaching Quality ‘must Improve’

‘The South African government and its partners should find ways to put effective measures in place so that better results could be achieved at all school levels in future,” says Education Minister Naledi Pandor. Read more

America’s Female Dentists Support More Liberal Politics Than Male Colleagues

A recent Wealthy Dentist survey asked dentists who they would like to see win the upcoming US presidential election. Two out of three dentists responding to this survey said they would rather see a Republican in the Oval Office than a Democrat. Among the dentists surveyed, the Republican favorite was Mitt Romney, while Democrats prefer Hillary Clinton. Read more

Lack of Deep Sleep May Increase Risk of Type 2 Diabetes

Suppression of slow-wave sleep in healthy young adults significantly decreases their ability to regulate blood-sugar levels and increases the risk of type 2 diabetes, report researchers at the University of Chicago Medical Center in the “Early Edition” of the Proceedings of the National Academy of Science, available online as soon as Dec. 31, 2007.

Deep sleep, also called “slow-wave sleep,” is thought to be the most restorative sleep stage, but its significance for physical well-being has not been demonstrated. This study found that after only three nights of selective slow-wave sleep suppression, young healthy subjects became less sensitive to insulin. Although they needed more insulin to dispose of the same amount of glucose, their insulin secretion did not increase to compensate for the reduced sensitivity, resulting in reduced tolerance to glucose and increased risk for type 2 diabetes. The decrease in insulin sensitivity was comparable to that caused by gaining 20 to 30 pounds.

Previous studies have demonstrated that reduced sleep quantity can impair glucose metabolism and appetite regulation resulting in increased risk of obesity and diabetes. This current study provides the first evidence linking poor sleep quality to increased diabetes risk.

“These findings demonstrate a clear role for slow-wave sleep in maintaining normal glucose control,” said the study’s lead author, Esra Tasali, MD, assistant professor of medicine at the University of Chicago Medical Center. “A profound decrease in slow-wave sleep had an immediate and significant adverse effect on insulin sensitivity and glucose tolerance.”

“Since reduced amounts of deep sleep are typical of aging and of common obesity-related sleep disorders, such as obstructive sleep apnea these results suggest that strategies to improve sleep quality, as well as quantity, may help to prevent or delay the onset of type 2 diabetes in populations at risk,” said Eve Van Cauter, PhD, professor of medicine at the University of Chicago and senior author of the study.

The researchers studied nine lean, healthy volunteers, five men and four women between the ages of 20 and 31. The subjects spent two consecutive nights in the sleep laboratory, where they went to bed at 11 P.M., slept undisturbed but carefully monitored, and got out of bed 8.5 hours later, at 7:30 A.M.

The same subjects were also studied for three consecutive nights during which they followed identical nighttime routines. During this session, however, when their brain waves indicated that they were drifting into slow-wave sleep they were subtly disturbed by sounds administered through speakers beside the bed.

These sounds were loud enough to disrupt deep sleep but not so loud as to cause a full awakening. This technique enabled the researchers to decrease slow-wave sleep by about 90 percent, shifting the subjects from the onset of deep sleep (stage 3 or 4) to a lighter sleep (stage 2) without altering total sleep time.

“Our system proved quite effective,” Tasali said. When asked about the sounds the next morning, study subjects vaguely recalled hearing a noise “three or four times,” during the night. Some recalled as many as 10 to 15. On average, however, subjects required about 250-300 interventions each night, fewer the first night but more on subsequent nights as “slow-wave pressure,” the body’s need for deep sleep, accumulated night after night.

“This decrease in slow-wave sleep resembles the changes in sleep patterns caused by 40 years of aging,” Tasali said. Young adults spend 80 to 100 minutes per night in slow-wave sleep, while people over age 60 generally have less than 20 minutes. “In this experiment,” she said, “we gave people in their 20s the sleep of those in their 60s.”

At the end of each study, the researchers gave intravenous glucose (a sugar solution) to each subject, then took blood samples every few minutes to measure the levels of glucose and insulin, the hormone that controls glucose uptake.

They found that when slow-wave sleep was suppressed for only three nights, young healthy subjects became about 25 percent less sensitive to insulin. As insulin sensitivity decreased, subjects needed more insulin to dispose of the same amount of glucose. But for eight of the nine subjects, insulin secretion did not go up to compensate for reduced effects. The result was a 23 percent increase in blood-glucose levels, comparable to older adults with impaired glucose tolerance.

Those with low baseline levels of slow-wave sleep had the lowest levels after having their sleep patterns disrupted and the greatest decrease in insulin sensitivity.

The alarming rise in the prevalence of type 2 diabetes is generally attributed to the epidemic of obesity combined with the aging of the population. “Previous studies from our lab have demonstrated many connections between chronic, partial, sleep deprivation, changes in appetite, metabolic abnormalities, obesity, and diabetes risk,” said Van Cauter. “These results solidify those links and add a new wrinkle, the role of poor sleep quality, which is also associated with aging.”

“Chronic shallow non-REM sleep, decreased insulin sensitivity and elevated diabetes risk are typical of aging,” the authors conclude. “Our findings raise the question of whether age-related changes in sleep quality contribute to the development of these metabolic alterations.”

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‘Swish-and-spit’ Test Accurate for Cancer

A morning gargle could someday be more than a breath freshener - it could spot head and neck cancer, say scientists at the Johns Hopkins Kimmel Cancer Center.

Their new study of a mouth rinse that captures genetic signatures common to the disease holds promise for screening those at high risk, including heavy smokers and alcohol drinkers.

Lead investigator Joseph Califano, M.D., says his group at Johns Hopkins asked 211 head and neck cancer patients and 527 individuals without cancers of the mouth, larynx or pharynx to brush the inside of their mouths, then rinse and gargle with a salt solution.

The researchers collected the rinsed saliva and filtered out cells thought to contain one or more of 21 bits of chemically altered genes common only to head and neck cancers. Tumor and blood samples also were collected.

The cellular mishaps occur when small molecules called methyl groups clamp on to the DNA ladder structure of a gene. In the grip of too many methyl groups, these genes can incorrectly switch on or off in a process called hypermethylation. “Mass-methylation” of particular genes can lead to cancer, the researchers say. Methylation mistakes in other genes could be triggered simply by aging and amount to no more than fine lines and wrinkles.

“The challenge is to predict which hypermethylated genes are most specific to cancer,” says Califano, an associate professor of otolaryngology - head and neck cancer and oncology at Johns Hopkins. And because every cancer process involves a unique genetic fingerprint, combining several gene signatures for the disease rather than using single ones may identify a larger percentage of cancer patients.

Califano and his colleagues’ report in the January 1 issue of Clinical Cancer Research noted that of 21 hypermethylated genes, seven of them were the best predictors of cancer within cell-laden saliva. Of the seven best, he tested panels of three to five genes on saliva rinses.

One panel correctly identified 66 out of 154 patients (42.9 percent) with the disease, and accurately ruled out the disease in 203 of 248 healthy subjects (81.9 percent).

Califano’s team used a different set of seven hypermethylated genes among blood samples as well. Although the blood test was more accurate than the saliva test at detecting cancer in patients with the disease (34 out of 37), there was a trade-off in the number of healthy individuals it spotted (53 of 173).

“Few tests can be perfect 100 percent of the time in identifying both normal and cancerous cells,” says Califano. “Because head and neck cancers are not widespread, it makes more sense to screen those at high risk and to focus on a test’s ability to accurately rule out healthy people.”

Califano notes that tests designed for broader populations, like PSA, focus on identifying a widespread disease in large numbers of people.

A saliva test, Califano says, is easy to do, painless and cheap, capturing cells from a wide area of the mouth. Some head and neck tumors do not shed genetic material into the blood, making the saliva test a better bet.

The Johns Hopkins investigators said more studies are needed to refine the test by uncovering additional hypermethylated genes that play a role, and to automate the test before multi-institutional clinical trials can begin. One of the first clinical uses for such a test could be to detect recurrence in current head and neck cancer patients.

There are nearly 50,000 cases of head and neck cancer diagnosed in the U.S. annually. Most are found when the disease has spread, and less than a year after diagnosis, many recur. Causes include heavy tobacco and alcohol use. Other head and neck cancers are caused by the sexually transmitted human papillomavirus.

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Silence May Lead to Phantom Noises Misinterpreted As Tinnitus

Phantom noises, that mimic ringing in the ears associated with tinnitus, can be experienced by people with normal hearing in quiet situations, according to new research published in the January 2008 edition of Otolaryngology - Head and Neck Surgery.

The Brazilian study, which consisted of 66 people with normal hearing and no tinnitus, found that among subjects placed in a quiet environment where they were asked to focus on their hearing senses, 68 percent experienced phantom ringing noises similar to that of tinnitus. This is compared to only 45.5 percent of participants who heard phantom ringing when asked to focus on visual stimuli and not on their hearing, and 19.7 percent of those asked to focus on a task in a quiet environment.

The authors believe that these findings show that with regards to tinnitus, the role of attention to symptoms, as well as silence, plays a large role in experience and severity.

Tinnitus, an auditory perception that cannot be attributed to an external source, affects at least 36 million Americans on some level, with at least seven million experiencing it so severely that it interferes with daily activities. The disorder is most often caused by damage to the microscopic endings of the hearing nerve in the inner ear, although it can also be attributed to allergies, high or low blood pressure (blood circulation problems), a tumor, diabetes, thyroid problems, injury to the head or neck, and use of medications such as anti-inflammatories, antibiotics, sedatives, antidepressants, and aspirin.

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