Gene mapping of the inner ear: Effects on hearing and balance

Hearing loss associated with aging or other disorders is a significant public health problem.

Within the inner ear are specialized sensory cells that include hair cells. Additional supporting cells also contained in the cochlea, provide structural and functional support to the hair cells. Collectively, these specialized cells help detect sound and enable us to hear. Similar specialized cells located in the utricle (pouch near the cochlea) help us maintain balance. This is part of the vestibular system.

These specialized cells are not able to repair themselves or regenerate. Aging along with certain medications, injuries, disease processes, and infections can lead to a loss of hearing and balance problems.

Research scientists from the University of Maryland School of Medicine and scientists from Tel Aviv University Sackler School of Medicine have collaborated in identifying a technique to help isolate a family of proteins that are essential for inner ear cell development.

Historical methods of analyzing gene activity have usually required thousands of cells. In contrast, the research teams, supported by the National Institute on Deafness and Other Communication Disorders (NIDCD) utilized a new technique for analyzing gene activity within one cell. This has allowed the researchers to better understand developmental patterns associated with the inner ear and vestibular system. This new knowledge may help lead to identifying ways to promote regeneration within the inner ear.

In a second study, the researchers used RNA sequencing technology to search for common regulatory regions within the genes expressed in specialized hair cells. They found a group of gene regulators known as Regulatory Factor Xs (RFX) are particularly active in the hair cells. This is believed to play a large part in hearing. In mice who lacked two RFX proteins, loss of hair cells and hearing occurred within 2 weeks after birth. Deafness occurred at approximately 3 months.

 

References:

National Institute on Deafness and Other Communication Disorders (NIDCD)

http://www.nidcd.nih.gov/news/releases/15/Pages/10152015.aspx

Are Annual Physicals Really Necessary?

27th Jan 2016 Medical News

It is estimated that over 45 million Americans will get a routine physical examination this year. Certain aspects of the annual physical are now covered under preventative care without cost to the patient.

Interestingly, an article written by Dr. Ezekiel Emanuel, who is one of the experts that helped develop President Obama’s health care law feel that for most, an annual physical is “worthless”. He further contends that the cost of annual exams outweighs any potential benefits. This has sparked a great debate over whether the routine annual physical is really necessary.

There has been a greater push for evidence-based medicine. Taken from a 2012 review conducted by an international group of researchers, 14 randomized clinical trials that included over 182,000 people found that annual physical exams do not lower the overall cost of medical care, future appointment, disease-related deaths or even hospitalizations. Some such as Dr. Emanuel further contend that annual exams may lead to further screenings or tests with abnormal findings which have no specific meaning.

While some argue that annual physicals are geared primarily toward insurance companies and billing, many physicians feel that waiting until you are sick to establish with a physician is not the best practice. A one-on-one interaction with the physician in a non-stressed time that may allow a better physician-patient connection and thereby giving the physician a greater overall understanding of the patient. Perhaps a restructuring of the annual physical would be more beneficial? This point has been brought up by some physicians.

Based on the results of large longitudinal population study (Aerobic Longitudinal Study) of over 12,000 people, 99.8% of middle age adults do not manage the 7 primary risk factors in cardiovascular (and other) diseases:

  1. Avoid smoking
  2. 30 minutes of moderate physical activity daily
  3. Control cholesterol levels
  4. Manage blood pressure
  5. Manage weight
  6. Control blood sugar
  7. Eat healthy foods

Only 0.2% of the study participants managed all 7 habits in their lifestyle! Fewer than 10% met 5 more of the habits described above. No cardiovascular related events occurred in any of the participants who met ideal levels of the 7 habits during the 20 year period of the study.

Taking this information into account, perhaps risk stratification (presence of medical comorbidities, disease risk factors and medications taken) should dictate frequency of check-ups while those who are asymptomatic may not need an “annual” physical but rather a periodic visit to review preventative and lifestyle factors such as those mentioned in the Aerobic Longitudinal Study.

 

References:

Emanuel, Ezekiel. Skip Your Annual Physical. New York Times op-ed. January 9, 2015

Zika Outbreak in the Amercas and now in Florida

20th Jan 2016 Diseases

A recent outbreak of a mosquito borne virus known as Zika has been the source of great public health concern in Brazil. It is estimated that 1.3 million cases of Zika have been identified since May of 2015.

The Zika virus is named after the Zika Forest in Uganda, where in 1947 the virus was isolated from a Rhesus monkey. It was not until 2007, that the first major outbreak of the Zika virus took place in Micronesia. Since that time additional large outbreaks have occurred in French Polynesia with over 10,000 cases identified in late 2013. The current outbreak in Brazil, is the largest ever in the Americas.

The virus is transmitted to humans by the Aedes aegypti mosquito. Once bitten by an infected mosquito, symptoms usually begin after an incubation period of three to twelve days. The CDC estimates that one in five who are bitten by an infected mosquito will develop clinical symptoms. Symptoms of the disease include the onset of a headache, rash, fever, joint pain(s), conjunctivitis and malaise. Clinically, the disease can appear very similar to dengue. For most, the disease process is mild and can last up to a week. Until recent, no deaths have been reported, Brazilian health officials and doctors are recommending that women avoid getting pregnant until after mosquito season. The virus has been linked to babies born with a rare neurological disorder in which there is incomplete brain development, known as microcephaly. The number of cases identified during this recent outbreak is over 10 times the amount from 2014. A number of recent infant deaths are being investigated to identify if there is a link.

The first case of Zika was identified in Puerto Rico last month. Public Health experts anticipated the spread of the virus into the southern United States by the spring, but we already have had 3 cases in Florida and one in Hillsborough county..

At present, there is no specific antiviral treatment for the Zika virus. Treatment is focused around supportive care including rest, consumption of fluids to prevent dehydration, and the use of acetaminophen.

Minimizing exposure to mosquitos is the only way to prevent the spread of the virus. The use of appropriate repellents, protective clothing covering the extremities, and the use of mosquito nets and screens are recommended to minimize the potential for infection.

 References:

Information accessed from www.cdc.gov/zika/index.html