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Biomedical subjects

N M Trieff

Publications and source records attributed to N M Trieff.

At least 37 records · Page 2Linked to original sources

Inactivation of poliovirus by chloramine-T.

Since concern has recently been expressed about the presence of genotoxic substances due to chlorination of water and wastewater, chloramine-T (CAT) is proposed as an alternative disinfectant to chlorine. The viricidal properties of chlorine and CAT were compared. Kinetics of inactivation of poliovirus type 2 by chlorine and CAT in chlorine demand-free water were investigated by using a kinetic apparatus. Inactivation of the virus by chlorine and CAT occurred in two steps. The initial linear part of the inactivation curve followed a pseudo-first-order reaction with the virus. An obvious dose-response relationship was demonstrated with CAT. The rate of inactivation of the virus by CAT was faster in acid medium than in alkaline medium. Inactivation kinetic studies were performed at different temperatures, and the kinetic, Arrhenius, and thermodynamic parameters were evaluated. The rate of inactivation of poliovirus type 2 by chlorine was faster than that by CAT under identical conditions. A mechanism for the viral inactivation in acid conditions was proposed which led to a rate equation consistent with the experimental results. The results indicate that CAT may be an effective viricide against poliovirus type 2 in an acid medium.

Chloramines↗

Correlation of the chemical structure of 4-nitroquinolines inactivating human cytomegalovirus and established in vivo carcinogenicity tests.

Inactivation of the infectivity of human cytomegalovirus (CMV) and herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) has been observed following exposure to 4-nitroquinoline 1-oxide (NQO) or its metabolite, 4-hydroxyaminoquinoline 1-oxide (HAQO). The present study of the specificity of the chemical structure of 4-nitroquinolines demonstrated that both the 4-nitro and 1-oxide groups were required for inactivation of virus infectivity. Reduction of the 4-nitro group to a 4-hydroxyamino group enhanced activity, while further reduction to an amino group resulted in loss of activity against virus infectivity. The capacity to inactivate virus was also lost by substitution of the pyridine ring for the quinoline nucleus of NQO. The relationship between the chemical structure and the ability to inactivate viruses studied here correlates well with earlier in vivo carcinogenicity studies of the same group of chemicals.

4-Nitroquinoline-1-oxide↗

Kinetics of uptake and biliary excretion of benzo(alpha)pyrene and mutagenic metabolites in isolated perfused rat liver.

An isolated liver perfusion system was used as a simplifying tool to study the metabolism and excretion of benzo(alpha)pyrene (BP) as a prototype carcinogen/mutagen. Phenobarbital (PB) was used to induce liver microsomal enzymes in Sprague-Dawley male rats prior to isolated liver perfusion. Control livers were run simultaneously using generally tritiated (G-3H)BP/BP as substrate in the perfusion medium. Both biliary excretion and liver weight were increased in the induced compared to control liver, but biliary flow when corrected for liver weight is statistically the same for both control and PB-induced livers. The excretion rat of radioactivity in the bile is always higher for PB-induced than for control liver (maximum radioactive excretion at 1 hr). There is a more rapid radioactivity removal in the liver perfusion medium for PB-induced than for control livers. Data are explained by increased metabolism of BP in induced liver leading to the presence of more polar metabolites undergoing preferential biliary excretion than in the control liver. Results support in vivo experimental data. Extracts from liver and bile were tested for microbial mutagenicity by the Ames test (TA 100) after TLC separation. The control liver shows virtually no mutagenicity in bile, only in TLC fractions from the liver. The PB-induced liver shows significant mutagenicity in several TLC fractions in both bile and liver. The net effect of induction is to produce more mutagenic metabolites of BP, excreted in the bile, and presenting a significant exposure of carcinogens/mutagens, and consequent hazard to man.

Animals↗

High pressure liquid chromatographic separation of two major toxic compounds from Gymnodinium breve davis.

Cultured Gymnodinium breve cells were extracted in acidified ether and fractionated by a new, convenient procedure utilizing thin layer chromatography or elution dry column chromatography. The most toxic fraction was further separated either directly by analytical high pressure liquid chromatography (HPLC) or in subsequent work by preparative, followed by analytical HPLC. Two toxic compounds, designated T46 and T47, were isolated; purity of each was demonstrated by rechromatography in analytical HPLC with both adsorptive and reverse phase packings. Both the single pass and recycle modes of operation were used with two detector systems in each to demonstrate a single entity. UV, fluorescence, and stability data differentiated these compounds from previously described, less toxic components from G. breve.

Animals↗

Structure activity relation for some 1,4-benzodiazepinones: correlation between rate constants for reduction by sodium borohydride and antileptazol ED50.

Significant correlation in 11 different 1,4-benzodiazepinones has been established between log k2 (the second order rate constant for the reduction of the "azepinones" by sodium borohydride) and their ED50 against leptazol-induced seizures in mice. The results suggest a possible involvement of the carobnyl group at the receptor site.

Animals↗

Structure-activity relationships of some selected beta-adrenergic blocking agents--oxidation with N-bromosuccinimide.

A relationship between in vitro rate of oxidation by N-bromosuccinimide (NBS) and the pharmacologic activity (pA2) of different beta-adrenergic blockers for different blocking agent-tissue combinations has been studied. The rates of oxidation of the alcoholic group in the drugs by NBS, as well as their molecular conformations as represented by molecular models, were studied in order to determine requirements for selectivity and potency of action of beta-adrenergic blocking agents. Using data from all 7 drugs studied--both nonselective and selective blocking agents--no significant correlation between pA2 and -log k2 (k2 is the second order rate constant for the oxidative reaction) was found. If data from only the 4 nonselective agents were used (16 drug-tissue combinations), a correlation significant at p less than 0.01 was found. Hypotheses are presented to account for the selective action of some beta-adrenergic blocking agents.

Adrenergic beta-Antagonists↗

Contemporary work-related environmental diseases.

This paper is a general review of occupational diseases with particular emphasis on contemporary work-related diseases. Reasons for the difficulties in diagnosis and treatment of industrial disease are given. The basic principles of occupational health are reviewed. The particular occupational diseases discussed in detail are the clinical pneumoconioses, and the contemporary diseases: angiosarcoma from exposure to vinyl chloride and respiratory carcinoma from bichloromethyl ether exposure. Numerous other environmental hazards are mentioned. The role of the Occupational Safety and thealth Administration (OSHA) is discussed, as is the role of the physician from the point of view of taking an appropriate medical history from an occupational vantage and medical diagnosis of occupational disease. Attitudinal aspects are emphasized.

Attitude of Health Personnel↗

Sewage treatment by controlled eutrophication: bacterial study.

Several groups of bacteria were isolated and identified in an evaluation of the microbiological properties of a sewage treatment system involving the process of controlled eutrophication in a marine setting (J. G. Songer, N. M. Trieff, R. F. Smith, and D. Grajcer, 1974). Fecal coliforms, enterococci, Salmonellae, Shigellae, Vibrio parahaemolyticus, and Vibrio alginolyticus were studied at three stages of the treatment process. Significant reductions in fecal coliforms (P < 0.01) and enterococci (P < 0.01) were noted from raw sewage to effluent. Salmonellae and Shigellae were not detected at any stage, nor was V. parahaemolyticus. V. alginolyticus was isolated from the effluent only, reflecting the halophilic nature of the organism; low concentrations in raw sewage increased in the more saline effluent. Brine shrimp (Artemia salina), the herbivores in this system, were tested and found to have extremely low numbers of the organisms under study associated with them. Findings point further toward the use of this system as a combined mariculture-sewage treatment facility.

Analysis of Variance↗