ABSTRACT
Nine cases of septic arthritis following arthroscopy are reviewed retrospectively. All cases of septic arthritis followed arthroscopic surgery. The average age of the patients was 49 years. The diagnosis was confirmed by bacterial cultures of the joint aspirates. All cases were treated by appropriate antibiotics supplemented by repeat arthroscopy and placement of a suction irrigation system. The average stay in hospital was 21 days. The authors suggest that it is not possible to predict such a major complication based on risk factors and therefore present a cost/benefit analysis of antibiotic prophylaxis using first-generation cephalosporins as a possible means of reducing hospital costs and patient morbidity.
Subject(s)
Anti-Bacterial Agents/therapeutic use , Arthritis, Infectious/etiology , Arthroscopy/adverse effects , Premedication/economics , Adolescent , Adult , Arthritis, Infectious/economics , Arthritis, Infectious/prevention & control , Clostridium Infections/etiology , Cost-Benefit Analysis , Female , Humans , Knee Joint/surgery , Lactams , Length of Stay , Male , Middle Aged , Retrospective Studies , Shoulder Joint/surgery , Staphylococcal Infections/etiologyABSTRACT
The low tissue concentrations of tetrahydrobiopterin, as well as the antagonism between the catecholamine feedback inhibition of tyrosine hydroxylase and the reduced cofactor concentrations, suggest that dihydropteridine reductase may play an important role in the regulation of catecholamine biosynthesis. The interaction of the different components involved in the hydroxylation of tyrosine was studied in vitro in a complex system composed of tyrosine hydroxylase, dihydropteridine reductase, and the different cofactors. This system has several important characteristics: (a) the rate of dihydroxyphenylalanine formation can be controlled by the concentration of dihydropteridine reductase; (b) low concentrations of catecholamines (2 x 10(-5) M) can produce a marked inhibition of tyrosine hydroxylase activity; and (c) the catecholamine feedback-inhibition of tyrosine hydroxylase can be antagonized by increasing concentrations of dihydropteridine reductase. The properties of the in vitro tyrosine hydroxylase-dihydropteridine reductase system suggest that dihydropteridine reductase may have an important role in vivo in the determination of the rates of dihydroxyphenylalanine formation and on the effectiveness of the catecholamine feedback-inhibition of tyrosine hydroxylase activity.
