Malekzadeh is prof. and dir., Digestive Disease Res. Inst., Tehran U. of Medical Sciences. He obtained his MD, specialty board of medicine and subspecialty board of gastroenterology from Shiraz U., Iran. He has worked in various capacities in Iranian med. eductn. and res. institutes. He was chancellor, Shiraz U.; Min. of Health and Medical Education; and secretary, Iranian Acad. of Med. Sciences. He has received 14 natl. awards including Razi, Avicenna, Yalda, Hadavi, Tabatbaei and Iranian Science awards. He is a member of 18 national and international academies and scientific societies. He has published more than 440 papers in internatl. journals with more than 1700 citations and is included among the top 1% world highly cited scientist in the clinical Medicine in Essential Science Indicators. His h-index is 53 in Scopus. He has established the Golestan Cohort and Persian cohort study in Iran.