Emmanuel N. Maduagwu

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The biochemical and toxicological effects of occupational and dietary exposure of humans to cyanide poisoning from large-scale cassava processing and ingestion of cassava foods were investigated using spectrophotometric and enzymatic methods. Analysis of urinary and serum thiocyanate (cyanide metabolite) from workers in cassava processing industries, who(More)
A survey to determine the extent of the nitrosamine contamination of some popular fermented Nigerian beverages by dimethyl- and diethylnitrosamine has been carried out in the Lagos, Ogun, Oyo, Ondo, Kwara and Benue States of Nigeria, following the mass spectrometric detection of these carcinogens in palm wine and nono (sour milk). The indication is that the(More)
The in vitro metabolism of nitrosodimethylamine (NDMA) was studied in liver tissue obtained from male weanling kwashiorkor wistar rats. The elimination of this compound and that of nitrosomorpholine (NMOR) from the blood, after a single intravenous dose, was also investigated. N-demethylase activity in liver microsomes of the test animals was not(More)
The ability of certain species of bacteria and yeasts that usually contaminate fresh palm sap to induce the formation of the carcinogen dimethylnitrosamine from suitable precursors (trimethylamine, dimethylamine, nitrate, and nitrite) was investigated in vitro under neutral and acid pH conditions. In the incubation media containing cell suspensions of each(More)
The effect of graded levels of thiamin on the metabolism of linamarin was investigated in rats. It was observed that on a diet deficient in thiamin, a large amount of linamarin was recovered unchanged in the urine, together with significantly more thiocyanate (SCN-) relative to the control. The least amount of thiocyanate (p less than 0.05 relative to(More)
  • E N Maduagwu
  • Food and chemical toxicology : an international…
  • 1989
The metabolism of linamarin [2(beta-D-glucopyranosyloxy)isobutyronitrile] was investigated in male albino Wistar rats and using rat liver microsomal preparations. In the in vitro experiments incubations of varying concentrations of linamarin at pH 6.0-6.5 with liver microsomal preparations resulted in rapid degradation of the substrate without concomitant(More)
The biliary excretion of linamarin (2[beta-D-glucopyranosyloxy]isobutyronitrile) was studied in male albino Wistar rats injected i.p. with single doses of 300 mg linamarin/kg following cannulation of the bile duct in vivo; 24 hr faeces of uncannulated rats, similarly dosed, was examined for excretory products. Enzymatic and spectrophotometric analyses of(More)
The hepatotoxicity which usually accompanies the oral administration of dimethylnitrosamine (DMN) to laboratory animals was studied in male rats, guinea pigs, cats, lizards, ducks, and monkeys. A single dosage of 50 mg/kg, which is necrotizing to rat liver, in most cases produced within 30 hr more acute liver damage in cats than in guinea pigs, rats, or(More)
Nitrosatability of dried Nigerian vegetables and spices was investigated under simulated gastric conditions. N-Nitroso-dimethylamine (NDMA) was the only volatile nitrosamine found above the preformed level except in ugwu where N-nitroso-piperidine (2.3 ppb) was also detected. The lowest NDMA value of 0.4 ppb was found in bitterleaf while onions had the(More)