Claud Andrew Powers, Ph.D., has 40 research publications, most of which are related to the physiological regulation and function of tissue kallikrein – a protease he discovered in the rat pituitary gland. Tissue kallikrein is involved in the generation of bioactive peptides, and in the rat pituitary kallikrein is selectively localized in the pars intermedia (which makes POMC-related peptides such as alpha-melanocyte-stimulating hormone) and in prolactin-producing cells (lactotrophs) of the anterior pituitary. In rat pituitary lactotrophs, kallikrein exhibits a major sex difference due to powerful induction by estrogens; it is also subject to inhibitory regulation by dopaminergic neuroendocrine systems. Dr. Powers discovered a novel thiol-dependent processing reaction where kallikrein processed prolactin (25K) to novel products by a set of cleavages in the C-terminal domain to yield a 21K processed form and other small peptides. The 21K prolactin product was subsequently identified as a hormonally regulated product of the regulated secretory pathway. The 21K processed prolactin exhibits both estrogen and dopaminergic regulation and is released from the pituitary. The functional role of this novel prolactin processing pathway remains unclear. Dr. Powers has been the course director of the medical pharmacology course in the School of Medicine at NYMC since 1998 and has mainly focused on medical education in pharmacology since that time. He has introduced a number on innovative teaching approaches into the medical pharmacology course and has received multiple awards for his teaching activities at NYMC. 

Education

• Ph.D., Pharmacology, University of Kansas Medical Center
• Postdoctoral Training, University of Tennessee Health Sciences Center

Honors and Awards

• Dean’s Faculty Award for Excellence in Mentoring – New York Medical College, 2021
• Certificate of Appreciation and Mentoring Award – New York Medical College, 2016
• Elected to Alpha Omega Alpha Honor Medical Society by NYMC SOM students, 2016
• Awarded Core of Medical Educators Membership, New York Medical College 2015
• Teaching Excellence Award – New York Medical College, 2013 and 2002

Research

Glandular kallikrein (GK) is a protease that can generate bioactive peptides from inactive precursor proteins. Investigation of the role of GK in prohormone processing led to its discovery in the pituitary where it is highly induced by estrogens and repressed by dopamine in lcells that secrete prolactin (PRL). A novel processing reaction was discovered which enabled GK to cleave 3 highly conserved sites in the C-terminus of PRL to generate a large N-terminal fragment (174 a.a.), and 3 smaller peptides (11, 3, and 9 a.a.). The pituitary was found to secrete an estrogen- dependent PRL product (PRL1-173) produced by GK processing. The biological significance of this unusual processing remains a mystery.

Another research interest concerned the role of hormonal interplay in integrative physiology. The work indicates that estrogens and antiestrogens can modulate the actions and/or secretion of thyroid hormone, growth hormone (GH) and insulin-like growth factor I (IGF-I) to influence energy balance, bone and lipid metabolism, growth and cardiovascular function. Conversely, changes in the functional status of the thyroid or GH-IGF-I axis may alter the effects of estrogens and antiestrogens on such targets. The potential role of estrogen-related receptor-gamma in tamoxifen actions have also been an area of interest. The research may provide insights relevant to novel therapeutic uses for antiestrogens.

Educational Research Interests:

The relation of student attendance at voluntary class sessions is an area of interest of Dr. Powers. ‘Audience-response systems’ (ARS) are used in large classroom settings to provide students with the opportunity to actively engage with the material being presented in a stimulating manner that provides students with immediate feedback on their learning. Data collected in such sessions is being analyzed to examine the relation of class attendance to student performance, and the utility of such technology for enhancing student learning.

Publications

• Laffey M, Ashwat E, Lui H, et. al. "Corrigendum to "Donor-recipient race-ethnicity concordance and patient survival after liver transplantation" [HPB 26 (2024) 772-781]." HPB : the official journal of the International Hepato Pancreato Biliary Association, 26(9), (2024) 1203. doi: 10.1016/j.hpb.2024.06.007
• Laffey M, Ashwat E, Lui H, et. al. "Donor-recipient race-ethnicity concordance and patient survival after liver transplantation." HPB : the official journal of the International Hepato Pancreato Biliary Association, 26(6), (2024) 772-781. doi: 10.1016/j.hpb.2024.03.003
• Hsiao-Nakamoto J, Chiu CL, VandeVrede L, et. al. "Alterations in Lysosomal, Glial and Neurodegenerative Biomarkers in Patients with Sporadic and Genetic Forms of Frontotemporal Dementia." bioRxiv : the preprint server for biology, (), (2024) . pii: 2024.02.09.579529. doi: 10.1101/2024.02.09.579529
• Russell SR, Drack AV, Cideciyan AV, et. al. "Intravitreal antisense oligonucleotide sepofarsen in Leber congenital amaurosis type 10: a phase 1b/2 trial." Nature medicine, 28(5), (2022) 1014-1021. doi: 10.1038/s41591-022-01755-w
• Johnston PA, Kitchens JL, LaBree K, et. al. "COVID-19 and Oncology: Operationalizing Best Practices Across Collaborative Health Systems." Clinical journal of oncology nursing, 24(4), (2020) 444-447. doi: 10.1188/20.CJON.444-447
• Kim M, Powers CA, Curtin LI, et. al. "A Translational Hepatic Artery Infusion (HAI) Model for Hepatocellular Carcinoma in Woodchucks." The Journal of surgical research, 251(), (2020) 126-136. doi: 10.1016/j.jss.2020.02.002
• Sumaroka A, Cideciyan AV, Charng J, et. al. "Autosomal Dominant Retinitis Pigmentosa Due to Class B Rhodopsin Mutations: An Objective Outcome for Future Treatment Trials." International journal of molecular sciences, 20(21), (2019) . doi: 10.3390/ijms20215344

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Professional Service

• Executive-Chief-Proctor of NBME Exams at NYMC (2002 to Present)
• Director of Ph.D. Program in Pharmacology at New York Medical College (1987 to 1994)
• Chair of Task Group on Student Services, Catalogs, Publications and Promotional Materials: Self-Study for Accreditation by the Middle States Association/Council of Higher Education (MSA/CHE) (1994 to 1995)
• Chair of NYMC Radiation Safety Committee (2000 to 2013)
• Chair of Faculty Subcommittee of the LCME Task Force for SOM Re-Accreditation (December 2013 to April 2015)
• Member of Curriculum Re-Design Steering Committee (September 2019 to Present)

Memberships and Affiliations

• Endocrine Society
• American Society for Pharmacology and Experimental Therapeutics
• Federation of American Societies of Experimental Biology

Teaching Responsibilities

• Course Director: Medical Pharmacology I (SOM)
• Course Director: Medical Pharmacology II (SOM)
• Course Director: Selected Topics in Endocrine Pharmacology (GSBMS)
• Course Director: Selected Topics in Neuropharmacology (GSBMS)
• Lecturer: Pharmacology Part I (GSBMS)
• Lecturer: Pharmacology Part II (GSBMS)
• Lecturer: Dental Pharmacology (TCDM)