Claud Andrew Powers, Ph.D.

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

• Member, Alpha Omega Alpha Honor Medical Society 
• Dean’s Faculty Award for Excellence in Mentoring, New York Medical College, 2021
• Certificate of Appreciation and Mentoring Award, New York Medical College, 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 live student attendance at voluntary class lectures is an area of educational interest of Dr. Powers. He introduced the use of ‘audience-response systems’ (ARS) in large classroom lectures to provide students with the opportunity to actively engage with the material being presented. Students can use their cell phones to answer questions posed in lecture, and the correct answers are then shown to provide immediate feedback. Students are also encouraged to interact/discuss questions prior to answering to enhance the learning experience. Data collected in such sessions is being analyzed to examine the relation of engaged lecture attendance to student performance, and the value of such technology for enhancing student learning.

Publications

• Conroy C, Bylsma S, Nasari A, et. al. "US professional medical societies' public statements regarding violence in Palestine and Israel from October to December 2023: a mixed-methods study." BMJ open, 16(7), (2026) e089385. doi: 10.1136/bmjopen-2024-089385
• Hung JH, Iyer I, Thng ZX, et. al. "Proteomic profile of faricimab-associated occlusive retinal vasculitis." Eye (London, England), 40(3), (2026) 293-296. doi: 10.1038/s41433-025-04175-5
• Liu H, Zhang W, Di M, et. al. "Survival benefit associated with liver transplantation for hepatocellular carcinoma based on tumor burden scores at listing." Hepatology communications, 9(1), (2025) . doi: 10.1097/HC9.0000000000000619
• Kim M, Powers CA, Fisher DT, et. al. "Enhancing Anti-PD-1 Immunotherapy by Targeting MDSCs via Hepatic Arterial Infusion in Breast Cancer Liver Metastases." Cancers, 16(21), (2024) . doi: 10.3390/cancers16213711
• 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

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Memberships and Affiliations

• Endocrine Society
• American Society for Pharmacology and Experimental Therapeutics

Teaching Responsibilities

• Lecturer Fundamental Processes of Life (SOM year 1)
• Lecturer Introduction to Systems (Heme and Neoplasia)(SOM year 1)
• Lecturer Systems 1 (Brain and Behavior) (SOM year 1)
• Lecturer Systems 2 (Cardiorespiratory) (SOM year 2)
• Lecturer Systems 3 (Renal, Reproduction and Endocrine)(SOM year 2)
• Lecturer Systems 4 (GI, Dermatology, MS and Rheum) (SOM year 2)
• Lecturer Dental Pharmacology (Touro College of Dental Medicine)(year 1)
• Lecturer Pharmacology 1010 (GSBMS)(year 2)
• Lecturer Pharmacology 1020 (GSBMS)(year 2)
• Lecturer in advanced courses in Pharmacology (year 2 and 3 of GSBMS Ph.D. and M.S. programs)
• M.S. Literature Review Theses for GSBMS (Faculty sponsor or reader for multiple M.S. literature reviews every year.)