February 16, 2012

Aliquots — research highlights from VUMC laboratories


‘Acid test’ for cervical cancer

Women infected with human immunodeficiency virus (HIV) constitute one of the populations at highest risk for human papillomavirus-induced cervical cancer. While HIV-infected women in developing countries, such as India, are living longer thanks to antiretroviral therapy, their risk of invasive cervical cancer remains high due to lack of access to affordable and accurate cervical cancer screening and prevention services.

Visual inspection of the cervix after application of dilute acetic acid (household vinegar), or VIA, is being studied as a low-tech, low-cost alternative to the traditional screening method for cervical cancer: the Pap smear (or cervical cytology). Vikrant Sahasrabuddhe, M.D., Dr.P.H., and colleagues compared the accuracy of cervical cytology with VIA for detection of cervical precancerous changes in 303 HIV-infected women in Pune, India.

In the Jan. 1 International Journal of Cancer, they report that VIA performed better than cytology in this setting, suggesting that VIA, which is easy and inexpensive, can be a good alternative or adjunct screening test for HIV-infected women.

The research was supported by grants from the National Cancer Institute, the National Institutes of Health’s Fogarty International Center and the Indian Council of Medical Research.

Melissa Marino


Stem cells take heart



Antonis Hatzopoulos, Ph.D., and colleagues are exploring how the Wnt signaling pathway, which is known to play many roles in cardiovascular development, regulates ES cell differentiation into other cell types. They report in the Jan. 1 issue of Stem Cells and Development that multiple waves of different types of Wnt signaling – “noncanonical” and “canonical” – regulate ES cell differentiation. Blocking the initial noncanonical Wnt signaling promoted blood cell development. Blocking the later peak of canonical Wnt signaling favored cardiovascular cell development and also activated compensatory Wnt signaling that further increased the number of cardiac progenitor cells.

The findings provide new insights on Wnt signaling during ES cell differentiation and point to a method for inducing the cells to become cardiac muscle cells.

This research was supported by grants from the National Heart, Lung and Blood Institute.

Leigh MacMillan


Memory intact in early psychosis

Patients with schizophrenia and psychotic bipolar disorder have widespread deficits in brain structure and function, but when these deficits appear and how they progress are open questions. Lisa Williams, Ph.D., and colleagues explored structure and function of the hippocampus, a brain region essential to memory and emotional processing, in patients in the early stage of psychotic illness.



The investigators trained early psychosis patients and healthy control subjects to perform a relational memory task (which requires the “binding” together of distinct memory elements). They tested the participants during a functional magnetic resonance imaging (fMRI) scan and measured hippocampal volume and activity. They found that many of the patients with early psychosis had normal hippocampal structure and function.

The results, reported in the Jan. 15 issue of Biological Psychiatry, provide evidence that some of the brain deficits found in chronic psychosis patients are not fully present in early stages of the disease. The findings provide a rationale for early intervention to delay, reduce or prevent memory deficits and hippocampal abnormalities.

This research was supported by the National Institute of Mental Health.

Leigh MacMillan


On the tail of RSV infection mechanism

Respiratory syncytial virus (RSV) is a leading cause of serious lower respiratory illness in infants and the elderly. However, there is no licensed RSV vaccine and therapeutic options are limited.

James Crowe Jr., M.D., and colleagues are studying the cellular life cycle of the virus. In the January/February issue of mBio, they describe the molecular mechanisms that drive the assembly of the virus into thread-like structures (filaments) at the surface of epithelial cells (the types of cells that line the airways). They show that a specific “bit” of the RSV fusion protein – an amino acid residue in the “tail” of the protein – is critical for coordinating the assembly of these filaments by mediating the incorporation of other viral proteins. Mutation of this residue prevented filament formation and the incorporation of other viral proteins into virus-like particles.

The findings, the authors suggest, could help guide the development of new antiviral therapies and also provide new insights about how the virus is released from infected cells and spreads.

The research was supported by grants from the National Institute of General Medical Sciences, the National Institute for Allergy and Infectious Diseases, the Burroughs Wellcome Fund, and the March of Dimes.

Melissa Marino


We welcome suggestions for research to highlight in Aliquots. The items should be primary research articles (no reviews, editorials or commentaries) published within the last two months in a peer-reviewed journal. Please send the article citation (PDF if available) and any other feedback about the column to: aliquots@vanderbilt.edu.



Past Aliquots

June 22, 2012
June 8, 2012
May 11, 2012
April 27, 2012
April 13, 2012
March 30, 2012
March 16, 2012