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Archive - Jun 14, 2013

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Skin Odor Analysis May Be Useful in Detection and Early Diagnosis of Melanoma

According to new research from the Monell Chemical Senses Center and collaborating institutions, odors from human skin cells can be used to identify melanoma, the deadliest form of skin cancer. In addition to detecting a unique odor signature associated with melanoma cells, the researchers demonstrated that a nanotechnology-based sensor could reliably differentiate melanoma cells from normal skin cells. The findings suggest that non-invasive odor analysis may be a valuable technique in the detection and early diagnosis of human melanoma. Melanoma is a tumor affecting melanocytes, skin cells that produce the dark pigment that gives skin its color. The disease is responsible for approximately 75 percent of skin cancer deaths, with chances of survival directly related to how early the cancer is detected. Current detection methods most commonly rely on visual inspection of the skin, which is highly dependent on individual self-examination and clinical skill. The current study took advantage of the fact that human skin produces numerous airborne chemical molecules known as volatile organic compounds, or VOCs, many of which are odorous. "There is a potential wealth of information waiting to be extracted from examination of VOCs associated with various diseases, including cancers, genetic disorders, and viral or bacterial infections," notes George Preti, Ph.D., an organic chemist at Monell who is one of the paper's senior authors. In the study, published in the July 15, 2013 issue of the Journal of Chromatography B, researchers used sophisticated sampling and analytical techniques to identify VOCs from melanoma cells at three stages of the disease, as well as from normal melanocytes. All the cells were grown in culture.

Same Gene Inhibits Breast Cancer and Strengthens Heart in Animal Model

Researchers at Case Western Reserve University have found that a single gene provides a double advantage against disease: Not only does it inhibit the growth and spread of breast tumors, but it also makes hearts healthier. In 2012, medical school researchers discovered the suppressive effects of the gene HEXIM1 on breast cancer in mouse models. Now they have demonstrated that it also enhances the number and density of blood vessels in the heart – a sure sign of cardiac fitness. Scientists re-expressed the HEXIM1 gene in the adult mouse heart and found that the hearts grew heavier and larger without exercise. In addition, the animals' resting heart rates decreased. The lowered heart rate indicates improved efficiency, and is supported by their finding that transgenic hearts were pumping more blood per beat. The team also discovered that untrained transgenic mice ran twice as long as those without any genetic modification. "Our promising discovery reveals the potential for HEXIM1 to kill two birds with one stone – potentially circumventing heart disease as well as cancer, the country's leading causes of death," said Monica Montano, Ph.D., associate professor of pharmacology, member of the Case Comprehensive Cancer Center, who created the mice for the heart and breast cancer research and one of the lead researchers in this study. Hypertension and subsequent heart failure are characterized by a mismatch between the heart muscles' need for oxygen and nutrients and blood vessels' inability to deliver either at the rate required. This deficit leads to an enlarged heart that, in turn, often ultimately weakens and stops. The researchers showed that increasing blood vessel growth through the artificial enhancement of HEXIM1 levels improved overall function – HEXIM1 may be a possible therapeutic target for heart disease.

Ancient and Modern Leprosy Bacterial Genomes Offer Insights into Disease History

From skeletons and biopsies, an international team of scientists has been successful in reconstructing a dozen medieval and modern genomes of the leprosy-causing bacteria Mycobacterium leprae. Under the direction of Professor Johannes Krause, University of Tübingen, and Professor Stewart Cole, Swiss Federal Institute of Technology of Lausanne (EPFL), the research group created a genome from archaeological finds for the first time without having to resort to a reference sequence. Professor Almut Nebel and Dr. Ben Krause-Kyora, both of the Institute of Clinical Molecular Biology, Kiel University, belong to the team, whose findings were published online on June 13, 2013 in Science magazine. Leprosy, a devastating infectious and chronic disease, was widespread in Europe until the Late Middle Ages. Persons infected with the disease were isolated in leprosy colonies specifically built for the patients. Today, the disease is found in 91 countries worldwide with more than 200,000 new infections per year. In order to trace the history of the disease, the scientists reconstructed the complete genomes of M. leprae from five medieval skeletons from Denmark, Sweden, and Great Britain. These specimens exhibited the characteristic bone changes associated with leprosy. Additionally, the M. leprae genetic substance was decoded from seven biopsy samples of contemporary patients. The researchers compared the European medieval M. leprae genome with those of the seven biopsies and four additional modern bacteria strains. They observed that all M. leprae strains have a common ancestor that existed less than 4,000 years ago. This result is supported by the earliest archaeological evidence of the disease in India.