Monthly Archives: August 2014

Tinnitus less common in women who drink more coffee

Otolaryngology_Nursing

A new study finds that women who consume more caffeine are less likely to have tinnitus – a condition where a person perceives noise in one or both ears, or in the head, even though there is no external sound.

 

The researchers, from Brigham and Women’s Hospital (BWH) in Boston, MA, write about their findings in The American Journal of Medicine.

According to the American Tinnitus Association, around 50 million people in the US experience some degree of tinnitus, which is often described as “ringing in the ears” although some people also hear hissing, buzzing, roaring, clicking or chirping. Of these, about 1 million are so badly affected they cannot function normally day to day.

For the study, the researchers analyzed data on over 65,000 women with and without tinnitus from the Nurses’ Health Study II.

The women were aged between 30 and 44 at the start of the study in 1991, when researchers collected a wealth of information on medical history, lifestyle and diet. At this point, the average caffeine intake was 242.3 mg per day – the equivalent of nearly two and a half 8-ounce cups of coffee. Most of the caffeine consumed came from coffee drinking.

In 2009, 18 years after they joined the study, the women were asked questions about tinnitus, including date of onset, where applicable. When a woman reported experiencing symptoms either daily or on a few days per week, the researchers counted it as a case. They identified a total of 5,289 cases of reported incident tinnitus.

Women who consumed more caffeine less likely to be among tinnitus cases

When they analyzed the results, the team found the more caffeine women consumed, the less likely they were to be among the tinnitus cases.

Senior author Gary Curhan, a physician-researcher in BWH’s Channing Division of Network Medicine and professor of Medicine at Harvard Medical School, says:

“We observed a significant inverse association between caffeine intake and the incidence of tinnitus among these women.”

He and his and colleagues found that regardless of age, rates of tinnitus were 15% lower among women who consumed 450-599 mg a day of caffeine, compared with women who drank less than 150 mg a day (about one and a half 8-ounce cups of coffee).

Prof. Curham notes that while the reason behind the finding is unclear, we know that “caffeine stimulates the central nervous system, and previous research has demonstrated that caffeine has a direct effect on the inner ear in both bench science and animal studies.”

The researchers say more evidence is required before we can say whether increased caffeine intake might improve tinnitus symptoms.

Funds from the National Institutes of Health helped finance the study.

Medical News Today recently reported on another study where researchers found tinnitus affects processing of emotions. Writing in the journal Brain Research, they describe how, compared with people not affected by the condition, those with tinnitus process emotions differently in the brain.

Written by Catharine Paddock PhD

http://www.medicalnewstoday.com/articles/280775.php

 

 

 

 

Biomarker for head and neck cancers identified

Otolaryngology

Although mutations in a gene dubbed “the guardian of the genome” are widely recognized as being associated with more aggressive forms of cancer, researchers at the University of California, San Diego School of Medicine have found evidence suggesting that the deleterious health effects of the mutated gene may in large part be due to other genetic abnormalities, at least in squamous cell head and neck cancers.

The study, published online in the journal Nature Genetics, shows that high mortality rates among head and neck cancer patients tend to occur only when mutations in the tumor suppressor gene coincide with missing segments of genetic material on the cancer genome’s third chromosome.

The link between the two had not been observed before because the mutations co-occur in about 70 percent of head and neck tumors and because full genetic fingerprints of large numbers of cancer tumors have become available only recently.

“These two genetic malfunctions are not two separate stab wounds to the body,” said co-senior author Trey Ideker, PhD, chief of the Division of Genetics. “One exposes the Achilles tendon and the other is a direct blow to it.”

To patients with these cancers, the study’s results mean that there may be therapeutic value in testing tumors for the two genetic identifiers, known as a TP53 mutation (short for tumor protein 53) and a 3p deletion (short for deletions of genetic information on the short arm “p” of the third chromosome).

TP53 plays a key role in regulating cell growth, detecting and fixing DNA, and directing cell apoptosis (death) if the DNA damage is irreparable. Because of this, the TP53 protein is sometimes called the “guardian of the genome.”

The study’s findings suggest that if both markers are present, treatment should be intensified. If only one mutation is present, treatment might be de-intensified because the TP53 mutation alone is less deadly than previously thought. The latter would have immediate benefits in reducing deaths caused by complications related to medical care.

“We are in the early stages of being able to personalize head and neck cancer treatments based on the tumor’s actual biology, the same as what’s done with breast cancers,” said co-senior author Quyen Nguyen, MD, PhD, associate professor of Otolaryngology-Head and Neck Surgery. “In the past, treatments have been based largely on the size and location of the tumor. Now, we know that some large tumors may respond to less aggressive treatment while some small tumors may need intensified treatment. This will have a huge impact for patients.”

The study analyzed the complete genomic signatures of 250 cases of squamous cell head and neck cancer extracted from The Cancer Genome Atlas, a repository of sequenced cancer genomes for more than 20 different types of human cancers maintained by the National Institutes of Cancer. All of the tumors were from patients younger than 85 years of age.

Of these, 179 had both mutations; 50 had one of the two mutations; and 22 had neither mutation. Comparisons with patient outcome data showed that half of patients with both mutations would likely die of cancer within 2 years, while 66 percent of patients with one or neither mutation would be expected to live five years or more. These survival statistics were independent of the patients’ clinical cancer stage.

Besides causing cervical cancer, the human papilloma virus (HPV) is implicated in the growing epidemic of head and neck cancers in otherwise healthy adults. It is believed that the virus can co-opt the activity of TP53, affecting cells in much the same way as a TP53 mutation but without causing a mutation. For this reason, the analysis examined HPV-positive and HPV-negative tumors separately.

One of the study’s more compelling discoveries is that among HPV-positive tumors, the most aggressive cancer cases were also highly linked to the presence of 3p deletions.

“Our findings raise fundamental questions about the role of TP53 in cancer and suggest that some of the deleterious health effects of TP53 mutations might actually be due to something else going on in the third chromosome,” said lead author Andrew Gross, a graduate student in the Bioinformatics and Systems Biology Program.

 

http://www.medicalnewstoday.com/releases/280558.php