Biomedical subjects
Publications and source records attributed to A I Hashem.
A dihydroampicillin (3) and a dihydrocephalexin (4) have been synthesized by condensing alpha-(cyclohexa-1, 3-dienyl)glycyl chloride with 6-aminopenicillanic acid (1) and 7-deacetoxycephalosporanic acid (2) respectively. The two antibiotics obtained show enhanced antimicrobial activity towards certain bacterial strains compared with ampicillin and cephalexin.
Utilizing Bayesian belief networks as a model of causality, we examined medical students' ability to discover causal relationships from observational data. Nine sets of patient cases were generated from relatively simple causal belief networks by stochastic simulation. Twenty participants examined the data sets and attempted to discover the underlying causal relationships. Performance was poor in general, except at discovering the absence of a causal relationship. This work supports the potential for combining human and computer methods for causal discovery.
alpha-(2-Thienylidene)-gamma-aryl-delta beta,gamma-butenolides 1 are prepared by condensing thiophene-2-aldehyde with beta-aroylpropionic acids in sodium acetate-acetic anhydride mixture. The butenolides react with ammonia in ethanol to give the corresponding 5-oxo-2-pyrrolines 2. Hydrazine hydrate reacts with the butenolides 1 with the formation of the corresponding acrylic acid hydrazides 3. Ring closure of the latter hydrazides with hydrochloric/acetic acid mixture gives the pyridazinones 4. The biological activity of the synthesized compounds is tested against bacterial and yeast strains. The butenolides 1 and the oxopyrrolines 2 inhibit the growth of yeast and gram-negative strain. The hydrazides 3 and the pyridazinones 4 are effective on gram-positive strains.