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Biomedical subjects

M Arroyo

Publications and source records attributed to M Arroyo.

68 records · Page 4Linked to original sources
PubMedDate not supplied

Activation and stabilization of penicillin V acylase from streptomyces lavendulae in the presence of glycerol and glycols.

Penicillin V acylase (EC 3.5.1.11) from Streptomyces lavendulae showed both enhanced activity and stability in mixed water/glycerol and water/glycols solvents. The catalytic activity was increased up to a critical concentration of these cosolvents, but further addition of the latter led to a gradual protein deactivation. The highest stabilizing effect was achieved in the presence of glycerol. Thermal stability was increased proportionally to the concentration of glycerol and glycols in the reaction mixture only if the amount added is below the threshold concentration. Reaction conditions that allow simultaneously enhanced activity and stability in the hydrolysis of penicillin V catalyzed by penicillin V acylase from S. lavendulae could be established.

Catalysis↗
PubMedDate not supplied

Effects of nitrate and prophylactic aspirin on upper gastrointestinal bleeding: a retrospective case-control study.

Experimental studies suggest that nitric-oxide releasing drugs reduce gastroduodenal damage induced by non-steroidal anti-inflammatory drugs, but it is not known whether these agents have this effect in humans. The aim of the present study was to evaluate the risk of upper gastrointestinal bleeding in patients who receive aspirin and nitrates for vascular occlusive diseases. This was a retrospective case-control study of 736 consecutive patients admitted with upper gastrointestinal bleeding, compared with 1472 age- and sex-matched hospital controls. Chronic low-dose aspirin regimens had been used by 12.6% of cases and 5.7% of controls, nitrates by 4.8% and 5.8%, and combined nitrates and low-dose aspirin by 2.7% and 1.9%, respectively. Logistic regression analysis identified low-dose aspirin use as an independent risk factor for gastrointestinal bleeding, whereas nitrate use was found to be a protective factor. The combination of both nitrate and low-dose aspirin was not associated with an increased risk of bleeding.

Anti-Inflammatory Agents, Non-Steroidal↗