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Biomedical subjects

J M Roche

Publications and source records attributed to J M Roche.

5 recordsLinked to original sources

Development of a research-based protocol to rule out tuberculosis by means of continuous quality improvement techniques.

Centers for Disease Control and Prevention guidelines mandate that patients be kept in respiratory isolation until three negative results of acid-fast bacillus smears, obtained on three separate days, have been documented. This mandate, coupled with the increased prevalence of Tuberculosis and a limited number of isolation rooms, indicated that an effective system needed to be developed to avoid unnecessary time spent in isolation. When it was found that patients spent a mean of 6.6 days in isolation before three negative results of acid-fast bacillus smears were obtained, a quality improvement project was initiated by the department of medicine. A multidisciplinary group with representation from epidemiology, nursing, medicine, the microbiology laboratory, and respiratory therapy reviewed current practice and developed a protocol to rule out tuberculosis. The protocol, which incorporates gastric lavage and sputum induction, facilitates the collection and processing of specimens within a target of 4 days from the time of placement in isolation. The protocol was reinforced by traditional staff education and large posters displayed on nursing units for easy reference. The mean time spent in isolation to rule out tuberculosis was significantly decreased with the protocol to 4.9 days (p < 0.001). After implementation, 56.6% of patients were out of isolation within 4 days, compared with only 2.6% before the protocol's implementation. This represents both a significant cost saving and improved patient outcomes. Current efforts center on continuous maintenance and improvement of these gains.

Adult↗

Effects of aging on monoamine oxidase activity of mouse and rabbit tissues.

The effect of aging on the monoamine oxidase (MAO) activity in tissues of mice and rabbits was evaluated. There were no alterations in the MAO activity of liver, kidney, pancreas and brain (adult mice and rabbits) or testis and heart (adult mice) with aging. There were no alterations in the norepinephrine content of the brain, kidney and heart of older mice. The present study indicates that increased MAO activity is not inevitably associated with aging in all species.

Aging↗

Monoamine oxidase and catechol-O-methyl transferase activity in Tetrahymena.

Tetrahymena pyriformis strain HSM was found to have monomine oxidase (MAO) and a catechol-3-methyl transferase-like (COMT) activity. As in mammalian tissues, the MAO activity is predominantly localized in the mitochondrial pellet and COMT in the cytosol. The COMT-like activity was present in amounts comparable to several mouse tissues and was inhibited by tropolone. MAO activity was much lower than in any of the mouse tissues tested, and its activity varied greatly from preparation to preparation. The substrate preference of Tetrahymena MAO was tryptamine greater than serotonin greater than dopamine, and activity increased with increasing pH from pH 6.5 to pH 7.8, as does that of mouse liver MAO. Teh Km of Tetrahymena MAO for tryptamine was approximately 4 micrometer, an order of magnitude lower than that of mouse liver MAO. Sensitivity of inhibition by MAO inhibitors was variable. In some preparations, no inhibition was observed. In others clear inhibition was obtained, harmine and clorgyline being among the most potent inhibitors.

Animals↗

Effect of ether, chloroform and carbon dioxide on monoamine inactivation.

To determine if anaesthetic agents alter monoamine inactivation, we exposed tissue homogenates (liver, kidney and brain) from mice and rabbits to ether and chloroform vapors and carbon dioxide gas. These anaesthetic agents inhibited monoamine oxidase (MAO) activity against typtamine and serotonin. Concentrations of anaesthetic agents that are achieved in the plasma of man during general anaesthesia caused a 27% (ether) and 49% (chloroform) reduction in mouse liver MAO; higher concentrations caused a 95% inhibition mouse or rabbit liver MAO. Kinetic analysis with tryptamine as substrate indicate that ether and chloroform are noncompetitive, reversible MAO inhibitors that preferentially inhibit Type B MAO. Ether and chloroform cause noncompetitive inhibition of serotonin oxidation by mouse liver MAO and competitive inhibition of serotonin oxidation by mouse brain and kidney MAO. Ether or chloroform did not alter catechol-O-methyltransferase activity from tissues of mice. Isolated blood platelets (rabbit and human) were used as a model system for neuronal uptake. Ether caused an irreversible inhibition of serotonin uptake by platelets.

Amines↗