Mary Lee Vance

Research Interests:Growth Hormone Physiology:The regulation of growth hormone (GH) secretion and the physiology of the decline in GH secretion with aging is a major focus of my research. Growth hormone has pivotal role in influencing protein, lipid and carbohydrate metabolism in adults. This hormone has an anabolic effect by increasing muscle mass and decreasing fat mass in adults with GH deficiency (usually a result of a pituitary gland tumor) and in older adults. Current research aims are to determine the reasons for the decline in GH secretion association with aging, the effects of GH replacement in GH-deficient adults and evaluation of novel new peptides which stimulate GH secretion in GH deficient adults and in older adults with diminished GH secretion. The other areas of research involves studies in patients with pituitary tumors. These studies involve administration of new medical therapies to treat specific types of pituitary tumor, i.e., GH secreting and prolactin secreting tumors. Recently developed drugs are effective in reducing excessive GH and prolactin secretion by these tumor types. These medications are an effective treatment for patients, either as primary therapy or in the setting of persistent hormone hypersecretion after surgery and/or radiation therapy. Additional studies involve the administration of hypothalamic hormones (GHRH, CRH) to determine the prevalence of GH deficiency and the need for chronic steroid replacement therapy in patients with known pituitary disease, primarily those treated with surgery and/or radiation therapy.Expertise:All of my research studies are conducted in adults, patients and normal volunteers. These groups are the ultimate test of scientific hypotheses and treatment strategies. Studies in human beings require particular precautions and safeguards as well as a testable hypothesis. In essence, these studies do not allow for discarding a study group and selecting another. Thus, the design of human studies requires attention to not only the hypothesis and study design to to issues of safety and efficiency. In evaluating the effects of growth hormone treatment, the administration of stable (non-radioactive) isotopes is used to determine the effects of GH on protein, lipid and carbohydrate metabolism. This methodology is used to the metabolic effects of GH therapy. Other methods of assessing treatment effects includes monitoring and interpreting exercise studies, oxygen consumption and strength studies.

The studies of growth hormone in adults are very relevant to the potential widespread use of this hormone to counteract some of the effects of aging to promoting more rapid recovery for severe catabolic illnesses and to providing GH replacement in adultswith GH deficiency.Expert witness:Medical malpractice cases (3) involving patients with Cushing's syndromeConsultancies: Serono Pharmaceutical Co.;Sandoz Pharmaceutical Co.;Sensus Drug Development Corp.;Wyeth Ayerst Pharmaceutical Co.