Biographies of Key Personnel

Padmanabhan Nair, Ph.D., Founder and President of the company, has over 45 years of research experience in the biomedical field.  He has held several key positions in academia and in the US government.  He was a Fulbright scholar to the Johns Hopkins University at the McCollum-Pratt Institute, elected Fellow of the AAAS and is a member of several prestigious professional societies.  For 21 years he was Director of Medical Research at Sinai Hospital of Baltimore.  For over a decade he was associated with the USDA's Beltsville Human Nutrition Research Center.  He is currently Adjunct Professor of International Health at the Johns Hopkins University.

Prasanna Nair, M.D., M.P.H. , Vice-President, has been on the faculty of the Department of Pediatrics, University of Maryland School of Medicine, for 43 years.  She is a Professor of Pediatrics, a clinician, educator, epidemiologist and researcher.  Her research has focused on early-intervention in substance-abusing women and their infants, vertical transmission of HIV, and care of HIV-exposed infants and children.   


Dr. Padmanabhan P. Nair

PPN.jpg (76357 bytes)Education

University of Travancore, India B.Sc. 1951 Chemistry, Physics, Biology
University of Bombay, India M.Sc. 1954 Biochemistry
University of Bombay, India Ph.D 1956 Biochemistry
McCollum Pratt Institute, Johns Hopkins University Postdoctoral 1960-62 Cell Biology

Professional Experience

1957-58     Postdoctoral Fellow, Indian Council of Medical Research, Institute of Science, Bombay
1958-60       Research Officer, Dept. of Pathology, All-India Institute of Med. Sciences, New Delhi
1960-63       Fulbright Scholar, Dept. of State, Johns Hopkins University
1960-62       Research Associate, Dept. of Biology and McCollum-Pratt Institute, Johns Hopkins University
1962-63       Senior Research Associate, Biochemistry Research Division, Dept. of Medicine, Sinai Hospital, Baltimore
1963-83       Director, Biochemistry Research Division and Division of Research Medicine, Sinai Hospital, Baltimore
1972-84       Lecturer, Dept. of Medicine, Johns Hopkins University School of Medicine, Baltimore
1980-88       Assistant Professor, Department of Biochemistry, Johns Hopkins University School of Hygiene & Public Health
1983-93       Research Scientist, Lipid Nutrition Laboratory, Beltsville Human Nutrition Research Center, ARS, USDA, Beltsville, MD
1991-97       Adjunct Associate Professor, Dept. of International Health, Center for Human Nutrition, Johns Hopkins School of Public Health
1993-98       Research Scientist, Nutrient Requirements & Functions Laboratory, Beltsville Human Nutrition Research Center, ARS, USDA
1997-pres   Adjunct Professor, Department of International Health, Center for Human Nutrition, Johns Hopkins University School of Public Health

Honors and Major Professional Assignments

1955-56      Raptakos Medical Research Fellow, India 
1960-63     Fulbright Scholar, Dept. of State 
1962          Visiting Scientist, City of Hope Medical Center, Duarte, CA
1962-64     Program Director, NIH Training Program in Lipid Metabolism, Dept. of Medicine, Sinai Hosp., Baltimore
1966          Elected Fellow, AAAS
1966-72     Member, Council AAAS
1968-72     Principal Investigator, Apollo Space Program Contract, "Pathophysiology of Hyperoxia"
1978          Elected to the Roll of Honor, Academic, Institute of Science, Bombay- Plaque unveiled by V. V.Giri, President of India 
1974-85     Associate Editor, "Lipids"
1978-81     Program Director: NCI "Collaborative Study on Dietary Patterns, Nutritional Assessment and Cancer Among American Vegetarians"
1979-pres  Member AAAS Consortium of Affiliates for International Programs
1980          Visiting Professor, Univ. of Kerala, Trivandrum 
1990          Invited Contributor, Section on BILE ACIDS in Encyclopedia of Human Biology, Ed. Renato Dulbecco
1991          Who's Who in the East

Major Accomplishments  


Developed the tocopherol-phosphomolybdic acid color reaction (Nair-Magar Color Reaction)


Pioneered the development of gas-liquid chromatographic techniques for fat-soluble vitamins, sterols, bile acids and steroid hormones.


Isolated Clostridium perfringens ATCC 19574 from a human subject and demonstrated the existence of a bile salt deconjugating enzyme, cholylglycine hydrolase (bile salt hydrolase). Purified and characterized the enzyme and made it available for distribution to other investigators worldwide for the deconjugation of the naturally occuring bile salt conjugates with glycine and taurine.


Developed the isolated human ovarian perfusion system for the study of steroid metabolism by the human ovary.


Postulated the role of vitamin E in the regulation of heme synthesis in hematopoietic and non-hematopoietic cells.


Demonstrated the therapeutic value of pharmacological doses of vitamin E for the treatment of porphyria cutanea tarda.


Isolated, identified and localized di-2-ethylhexyl phthalate (DEHP) in heart muscle mitochondria. This led to the discovery of DEHP as a plasticizer that migrates from blood bags into blood used in transfusions and the interest in DEHP and as an environmental problem.


Demonstrated that administration of vitamin E alleviated the symptoms of mammary dysplasia and that symptomatic relief was associated with a concomitant shift in ketosteroid excretion.


Demonstrated that lithocholic acid could occur in tissue-bound form. Isolated N--lithocholyl lysine from tissues and established proof of structure by synthesis.


Developed assay for the quantitative assessment of mutagenicity (SOS Microplate Mutagenicity Assay) and demonstrated that this method is a valuable adjunct to other markers of cancer risk.


Developed unique affinity column for the separation of eukaryotic DNA from prokaryotic DNA


Developed method to isolate colonic cells from fecal samples. This technique is a major advance in our ability to study cancer of the colon and other diseases of the large bowel. This approach can also be used for studying the influence of diet on the cells lining the gastrointestinal tract.


Nair, PP and Kritchevsky, D, (eds). The Bile Acids, Chemistry, Physiology and Metabolism, Vol. I Chemistry. 1971 Plenum Press, New York

Nair, PP and Kayden, HJ (eds). Vitamin E and its Role in Cellular Metabolism. Ann. N.Y. Acad. Sci., N. Y. Vol 203, 1972.

Nair, PP and Kritchevsky, D (eds). The Bile Acids, Chemistry, Physiology and Metabolism, Vol. II Physiology and Metabolism 1973. Plenum Press, New York.

Nair, PP and Kritchevsky, D (eds). The Bile Acids, Chemistry, Physiology and Metabolism, Vol. III  Pathophysiology Plenum Press, New York, 1976.

Nair, PP (ed). Diet, Nutrient Intake and Metabolism in Populations at High and Low Risk for Colon Cancer. Amer. J. Clin. Nutr. (Monograph), Vol 40 (4 Suppl), Oct. 1984.

Setchell, KDR, Kritchevsky, D, and Nair, PP (eds.). The Bile Acids, Chemistry, Physiology and Metabolism: Vol. IV Methods and Applications 1988. Plenum Press, New York.


Selected Publications
(over 200 peer-reviewed articles & book chapters)

Nair PP, Magar NG. Colorimetric determination of vitamin E. Indian J Med Res. 42(4):577-84, 1954.

Nair PP, Magar NG. Determination of vitamin E in blood. J. Biol. Chem. 220:157-160, 1956.

Nair PP, Sarlos IJ, Solomon D, and Turner DA. Simultaneous separation of 17-ketosteroids
and estrogens by biphase gas chromatography. Anal. Biochem. 7: 96, 1964.

Kritchevsky D, Werthessen NT, Shapiro IL, Nair PP, and Turner, DA. Transfer of radioactivity of cholesterol-7-3H to fatty acids of tissue lipids in vivo.  Nature 207: 194, 1965.

Nair PP, Sarlos I, and Machiz J. Microquantitative separation of isomeric dimethyltocols by gas-liquid chromatography. Arch. Biochem. Biophys. 114 (3): 488, 1966.

Okishio T and Nair PP. An improved column for gas-liquid chromatography of substituted cholanic acids. Anal Biochem 15: 360, 1966.

Okishio T and Nair PP. Studies on Bile Acids. Some observations on the intra-cellular localization of major bile acids in rat liver. Biochem. 5: 3662, 1966.

Nair PP, Gordon M, Reback J. The enzymatic cleavage of the carbon-nitrogen bond in 3, 7, 12-trihydroxy-5b-cholan-24-oylglycine. J Biol. Chem. 242: 7-10, 1967.

Okishio T, Nair PP, and Gordon. M. Studies on bile acids: Microquantitative separation of cellular bile acids by gas-liquid chromatography. Biochem. J. 102: 654, 1967.

Nazir DJ, Beroza M, and Nair, PP. Isolation and identification of di (2-ethylhexyl) phthalate - A component of heart muscle mitochondria. Fed. Proc. 26 (2): 412, 1967.

Nair PP, Gordon M, Tepper SA and Kritchevsky D. Conversion of 5,7-cholestadien-3β-ol to 3
, 7, 12-trihydroxy-5β-cholanoic acid in the bile fistula rat. J. Biol. Chem. 243: 4034, 1968.

Nair PP and deLeon S. Stereochemical studies on the microquantitative detection of vitamin D by gas-liquid chromatography. Arch. Biochem. Biophys. 128: 663, 1968.

Weglicki WB, Luna Z, and Nair PP. Alpha-tocopherol: Sex and tissue specific difference in mature and senescent rats. Nature 221: 185, 1969.

Murty HS and Nair PP. Prevention of allylisopropylacetamide-induced experimental porphyria in the rat by vitamin E. Nature 223: 200, 1969.

Hari SM, Caasi PI, Brooks SK, Nair PP. Biosynthesis of Heme in the Vitamin E-deficient Rat J. Biol. Chem. 245: 5498 - 5504, 1970. 

Nair PP, Banwell JG, Gorbach SL, Lilis C, Alcaraz A. Tropical Sprue and Malnutrition in West Bengal: III. Biochemical Characterisitics of Bile Salts in the Small Intestine. Am. J. Clinical Nutrition 23(12): 1569 - 1578, 1970.

Nair PP, Mezey E, Murty HS, Quartner J, and Mendeloff, AI: Vitamin E and porphyrin metabolism in man. Arch. Intern. Med. 128: 411, 1971.

Baggish MS, Strummer D, Nair PP and Frank J. Human ovary under isolated perfusion. Obstet. Gynecol. 38: 463, 1971.

Nazir DJ, Alcaraz AP, Bierl BA, Beroza M, and Nair PP. Isolation, identification, and specific localization of di-2-ethylhexyl phthalate in bovine heart muscle mitochodria. Biochem. 10: 4228, 1971.

Nazir DJ, Beroza M, Nair PP:  Di-2-ethylhexyl phthalate in bovine heart muscle mitochondria:  Its detection, characterization, and specific localization. Environ Health Perspectives 3:  141 -148,

Stein MS, Caasi P, Nair PP. Some aspects of DEHP and its action on lipid metabolism.
Environ Health Perspectives 3:149-52, 1973.

Sherr HP, Nair PP, White JJ, Banwell JG, Lockwood DH. Bile acid metabolism and hepatic disease following small bowel bypass for obesity. Am. J. Clinical Nutrition  27(12): 1369-1379, 1974.

Kritchevsky D, Davidson LM, Shapiro IL, Kim HK, Kitagawa M, Malhotra S,  Nair PP,  Clarkson TB, Bersohn I, Winter PAD. Lipid metabolism and experimental atherosclerosis in baboons: influence of cholesterol-free, semi-synthetic diets. Am. J. Clinical Nutrition 27(1): 29 - 50, 1974.

Hauswirth JW, Nair PP. Effects of different vitamin E-deficient basal diets on hepatic catalase and microsomal cytochromes P-450 and b5 in rats Am. J. Clinical Nutrition  28(10): 1087 - 1094, 1975.

Mazumder A, Patnaik RN, Bhagavan BS, Nair PP: Isolation and characterization of attached and non-attached populations of rat colon epithelial cells in culture. J. Natl Cancer Inst. 62: 1145-1449, 1979.

Turjman N, Nair PP: Nature of tissue-bound lithocholic acid and its implications on the role of bile acids in carcinogenesis. Cancer Res. 41:3761-3763, 1981.

Sundaram GS, London RS, Goldstein PJ, Wenk R, Lustgarten J, Margolis S, Nair PP: Serum hormones and lipoproteins in benign breast disease. Cancer Res. 41:3814-3816, 1981.

Nair PP, Turjman N: Role of bile acids and neutral sterols in familial cancer syndromes of the colon. Diseases of the Colon and Rectum. Dis. Colon Rectum 26:629-632, 1983.

Nair PP. Diet, nutrition intake, and metabolism in populations at high and low risk for colon cancer. Preface. Am. J. Clinical Nutrition 40(4 Suppl):879, 1984.

Nair PP. Diet, nutrition intake, and metabolism in populations at high and low risk for colon cancer. Introduction: correlates of diet, nutrient intake, and metabolism in relation to colon cancer. Am. J. Clinical Nutrition 40(4 Suppl):880-886, 1984. 

Calkins BM, Whittaker DJ, Nair PP, Rider AA, Turjman N. Diet, nutrition intake, and metabolism in populations at high and low risk for colon cancer. Nutrient intake. Am. J. Clinical Nutrition 40(4 Suppl), 896-905, 1984.

AA Rider, BM Calkins, RS Arthur, and PP Nair Diet, nutrition intake, and metabolism in populations at high and low risk for colon cancer. Concordance of nutrient information obtained by different methods. Am. J. Clinical Nutrition 40(4 Suppl): 906-913, 1984.

Rider AA, Calkins BM, Arthur RS, Nair PP. Diet, nutrition intake, and metabolism in populations at high and low risk for colon cancer. Concordance of nutrient information obtained by different methods. Am. J. Clinical Nutrition 40(4 Suppl):906-13, 1984.

Nair PP, Turjman N, Kessie G, Calkins B, Goodman GT, Davidovitz H, Nimmagadda G. Diet, nutrition intake, and metabolism in populations at high and low risk for colon cancer. Dietary cholesterol, beta-sitosterol, and stigmasterol. Am. J. Clinical Nutrition 40(4 Suppl):927-30, 1984.

Nair PP, Turjman N, Goodman GT, Guidry C, Calkins BM. Diet, nutrition intake, and metabolism in populations at high and low risk for colon cancer. Metabolism of neutral sterols. Am. J. Clinical Nutrition 40 (4 Suppl): 931-936, 1984.

Turjman N, Goodman GT, Jaeger B, Nair PP. Diet, nutrition intake, and metabolism in populations at high and low risk for colon cancer. Metabolism of bile acids. Am. J. Clinical Nutrition 40(4 Suppl):937-41, 1984.

Turjman N, Nair PP. Diet, nutrition intake, and metabolism in populations at high and low risk for colon cancer. In situ bromination for the separation of the cholesterol-cholestanol pair in human fecal extracts. Am. J. Clinical Nutrition 40(4 Suppl):952-956, 1984.

Nair, P.P., Kessie, G. and Turjman, N.: Synthesis of N--Lithocholyl-L-lysine, a component of tissue-bound lithocholic acid, via lithocholyl-N-hydroxysuccinimide. J. Steroid Biochem. 23: 573-576, 1985.

Nair, P.P., Kessie, G. and Flanagan VP. Reaffirmation of the validity of enzymatic cleavage of lithocholic acid from N-e-lithocholyl-L-lysine and N-a-CBZ-N-e-lithocholyl-L-lysine. J. Lipid Res. 27: 905-909, 1986.

Jones DY, Judd JT, Taylor PR, Campbell WS, Nair PP. Influence of caloric contribution and saturation of dietary fat on plasma lipids in premenopausal women
Am. J. Clinical Nutrition 45(6): 1451 - 1456, 1987.

Hamilton SR, Hyland J, McAvinchey D, Chaudhry Y, Harka L, Kim HT, Cichon P, Floyd J, Turjman N, Kessie G, Nair PP, Dick J: Effects of chronic dietary beer and ethanol consumption on experimental colonic carcinogenesis by azoxymethane in rats. Cancer Res. 47: 1551-1559, 1987.

Nair PP: Role of bile acids and neutral sterols in carcinogenesis. Am. J. Clinical Nutrition 48(9): 768-774, 1988.

Bhathena SJ, Berlin E, Judd J, Nair PP, Kennedy BW, Jones J, Smith PM, Jones Y, Taylor PR, Campbell WS. Hormones regulating lipid and carbohydrate metabolism in premenopausal women: modulation by dietary lipids. Am. J. Clinical Nutrition 49(5): 752 - 757, 1989.

Nair PP, Shami S, Sainz E, Menon M, Jerabek LB, Jones DY, Judd JT, Campbell WS, Schiffman MH, Taylor PR, Schatzkin A, Guidry C, Brown CC. Influence of dietary fat on fecal mutagenicity in premenopausal women. Int. J. Cancer 46:374-377, 1990.

Nair PP, Shami S, Sainz E, Judd JT, Taylor PR, Schatzkin A. Quantitative assessment of the genotoxicity of fecapentaenes. Mutation Res. 260: 153-157, 1991.

Iyengar V, Albaugh GP, Lohani A, Nair PP. Human stools as a source of viable colonic epithelial cells. FASEB J. 5: 2856-2859, 1991.

Bhathena SJ , Berlin E, Judd JT, Kim YC,  Law JS, Bhagavan HN, Ballard-Barbash R,  Nair PP. Effects of omega 3 fatty acids and vitamin E on hormones involved in carbohydrate and lipid metabolism in men. Am. J. Clinical Nutrition, 54(11): 684 - 688, 1991.

Kramer TN, Schoene N, Douglass LW, Judd JT, Ballard-Barbash R, Taylor PR, Bhagavan HN, Nair PP. Increased vitamin E intake restores fish-oil-induced suppressed blastogenesis of mitogen-stimulated T lymphocytes.
Am. J. Clinical Nutrition 54(11): 896 - 902, 1991.

Albaugh GP, Iyengar V, Lohani A, Malayeri M, Bala S, Nair PP. Isolation of exfoliated colonic epithelial cells, a novel non-invasive approach to the study of cellular markers. Int. J. Cancer 52: 347-350, 1992.

Nair PP. Nutrients and the human genome: New frontiers for the next century. FASEB J. 7: 501-502, 1993.

Nair PP, Judd JT, Berlin E, Taylor PR, Shami S, Sainz E, Bhagavan HN. Dietary fish oil-induced changes in the distribution of a-tocopherol, retinol, and -carotene in plasma, red blood cells, and platelets: modulation by vitamin E.
Am. J. Clinical Nutrition. 58(10): 98 - 102, 1993.

Nair, PP, Flanagan VP, Oliver JE. Electron impact ionization mass spectra of lithocholyl amides: evidence for a C(20) to C(23) rearrangement involving the loss of a C4 H9 fragmentOrganic Mass Spectrometry 29: 335-341, 1994.

Nair PP, Kessie G, Patnaik R, Guidry C. Isolation and HPLC of N-S-lithocholyl lysine as its fluorescamine and dimethylaminoazobenzene isothiocyanate derivatives. Steroids 59:212 - 216, 1994.


Pfeil RM, Venkat JA, Plimmer JR,Shami S, Davis K, Nair PP. Quantitative assessment of groundwater quality using a biological indicator: Some preliminary observations. Arch. Envir. Contam. Toxicology 26(2):201-207, 1994.

Han, JS, Nair PP. Flow cytometric identification of cell-surface markers on cultured colonic cell lines using monoclonal antibodies. Cancer 76: 195-200, 1995.

Mathew B, Sankaranarayanan R, Nair PP, Varghese C, Somanathan T, Amma BP, Amma NS, Nair MK. Evaluation of Chemoprevention of Oral Cancer with Spirulina fusiformis. Nutrition and Cancer 24:197-202, 1995.

Venkat JA, Shami S, Davis S, Nayak M, Plimmer JR, Pfiel R, Nair PP. Relative genotoxic activities of pesticides evaluated by a modified SOS microplate assay. Environ. Mol. Mutagen. 25: 67-76, 1995.

Bhathena SJ, Berlin E, Judd JT, Clevidence BA, Taylor PR, Campbell WS, Nair PP. Selective responses of hormones involved in carbohydrate and lipid metabolism and properties of erythrocyte membranes during the menstrual cycle in premenopausal women consuming moderate amounts of alcohol. Am. J. Clinical Nutrition 62(10): 751 - 756, 1995.

Nair PP, Lohani A, Norkus EP, Feagins H, Bhagavan HN. Uptake and distribution of carotenoids, retinol and tocopherols in human colonic epithelial cells, in vivo. Cancer Epidemiol. Biomarkers & Prev. 5: 913-916, 1996.

Dorgan JF, Judd JT, Longcope C, Brown C, Schatzkin A, Clevidence BA, Campbell WS, Nair PP, Franz C, Kahle L, Taylor PR. Effects of dietary fat and fiber on plasma and urine androgens and estrogens in men: a controlled feeding study. Am. J. Clinical Nutrition 64(12): 850 - 855, 1996.

Malayeri M, Albaugh G, Davis K, Bhathena S, Nair PP. Exfoliated human colonic epithelial cells: Insulin binding and molecular cloning of the insulin receptor. Med. Sci. Res. 25: 801-803, 1997.

Sankaranarayanan R, Mathew B, Varghese C, Sudhakaran PR, Menon V, Jayadeep A, Nair, MK, Mathews C, Mahalingam TR, Balaram P, Nair, PP. Chemoprevention of oral leukoplakia with vitamin A and b-carotene: an assessment. Oral Oncol. 33(4):231-236, 1997.

Dutta SK, Nair PP. Noninvasive detection of colorectal cancer by molecular tools: Coming of Age. Gastroenterology, Editorial 114:1333-1335, 1998.

Desilets DJ, Davis KE, Nair PP, Salata KF, Maydonovitch CL,Howard RS, Kikendall JW, Wong RKH, Lectin Binding To Human Colonocytes is Predictive of Colonic Neoplasia. Am.J. Gastroenterology 94:744-750, 1999.

Nair, PP. Lifestyle, Nutrition, and Lead Poisoning. Proceedings of the International Conference on Lead Poisoning Prevention & Treatment, Bangalore, India August 8 -10, 1999 

Nair PP, Davis KE, Shami S, Lagerholm S. The induction of SOS function in Escherichia coli K-12/PQ37 by 4-nitroquinoline oxide (4-NQO) and fecapentaenes-12 and -14 is bile salt sensitive:implications for colon carcinogenesis. Mutation Res. 447:179-185, 2000.

Iyengar GV, Nair PP: Global outlook on nutrition and the environment. Meeting the challenges of the next millennium. Science of the Total Environment 249(1-3):331-46, 2000 (United Nations).

Nair P, Lagerholm S, Dutta S, Shami S, Davis K, Ma S,  Malayeri M.  Coprocytobiology: on the nature of cellular elements from stools in the pathophysiology of colonic disease. J. Clin  Gastroenterol 36(5 Suppl): S84-93, discussion S94-6, 2003

Gireesh T, Nair PP, Sudhakaran PR. Studies on the bioavailability of the provitamin A carotenoid, beta-carotene, using human exfoliated colonic epithelial cells. Br. J. Nutrition. 92(2):241-5, 2004.

Lagerholm Sa, Lagerholm So,  Dutta S, Nair PP. Noninvasive detection of c-myc p64, c-myc p67 and c-erbb-2 in colorectal cancerScand J Gastroenterol. 40(11):1343-1350, 2005.

Nair PP, Kamra, A, Kalavapudi S, Kessie G, Shores R, Chen JAutologous Gastrointestinal Progenitor Stem Cells (GIP-C) Isolated from Stool Samples. GTCBio Stem Cell Research & Therapeutics April 11-12, 2005, p164.

Kamra A, Kessie G, Chen JH, Kalavapudi S, Shores RL, McElroy I, Gireesh T, Sudhakaran PR, Dutta SK, Nair PP. Exfoliated Colonic Epithelial Cells: Surrogate Targets for Evaluation of Bioactive Food Components in Cancer Prevention.  J. Nutr. 135:2719-2722,2005.