ABSTRACT
Bicycling is frequently recommended as a form of aerobic exercise to reduce the risk of cardiovascular events, yet it is not without safety risks. The recent accidental death of locally-known cyclist has raised safety concerns of recreational cycling on Arkansas roads. This article summarizes cycling accident statistics obtained from the Arkansas State Highway and Transportation Department for a three year period.
Subject(s)
Accidents, Traffic/statistics & numerical data , Bicycling , Adolescent , Arkansas/epidemiology , Bicycling/injuries , Child , Child, Preschool , HumansABSTRACT
Glutathione S-transferase (EC 2.5.1.18) was detected in the cytosolic and microsomal fractions of adult Dirofilaria immitis females at respective levels of 30 nmol and 3 nmol min-1 (mg protein)-1 activity with the substrate 1-chloro-2,4-dinitrobenzene (CDNB). The transferase activity in the cytosolic fraction of adult Brugia pahangi females was 10 nmol min-1 mg-1 with CDNB; determination of its activity in the microsomal fraction of this filariid was not attempted. These filarial glutathione S-transferases were further characterized after their purification by glutathione-affinity chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the cytosolic transferase from D. immitis, molecular weight 47000, yielded a single subunit of around 28 kDa. The cytosolic and microsomal transferases from D. immitis differed in their activity with CDNB, 1,2-dichloro-4-nitrobenzene, 4-benzylchloride and ethacrynic acid. The cytosolic transferase from B. pahangi was distinguished by its high activity with ethacrynic acid. Both glutathione S-transferases from D. immitis also functioned as a glutathione peroxidase, strongly preferring cumene hydroperoxide as a substrate over hydrogen peroxide. Both were equiactive inhibitors of malonaldehyde formation in the NADPH-microsomal lipid peroxidation system. Thus, in addition to the ability of filarial glutathione S-transferases to detoxify electrophilic xenobiotics, at least those from D. immitis also exhibited selenium-independent glutathione peroxidase activity. Their glutathione S-transferase function suggests a potential role for these enzymes in the leukotriene synthetic pathway, if filariae can form such eicosanoids from arachidonate. Functioning as a glutathione peroxidase, they could serve to protect filarial membrane lipids from peroxidation.
Subject(s)
Brugia/enzymology , Dirofilaria immitis/enzymology , Filarioidea/enzymology , Glutathione Transferase/metabolism , Animals , Chromatography, Affinity , Dinitrochlorobenzene/metabolism , Electrophoresis, Polyacrylamide Gel , Ethacrynic Acid/metabolism , Female , Glutathione Transferase/isolation & purification , Microsomes, Liver/enzymology , Molecular Weight , Nitrobenzenes/metabolism , Rats , Rats, Inbred StrainsABSTRACT
Direct culture on Lowenstein-Jensen slopes and on three media made selective for tubercle bacilli by the addition of four antibacterial agents was compared with guinea-pig inoculation on 490 tissue specimens. Tubercle bacilli were obtained from 15 specimens by culture and 14 by guinea-pig inoculation; only one specimen was positive by guinea-pig and not by culture. The most efficient culture medium was a selective 7H11 slope. Routine guinea-pig inoculation has been replaced by a wider range of culture procedures.