RESUMEN
On October 4, 2018, an outbreak of gastroenteritis associated with sapovirus occurred among elementary school students in Gyeonggi-do, Korea. Epidemiologic studies were conducted in a retrospective cohort approach. Using self-administered questionnaires, we collected information on symptoms and food items consumed. Of the 999 subjects, 17 developed patients that met the case definition. The main symptom was vomiting (100%), and the symptomatic age was 6-12 years. Positive samples were identified by conventional reverse transcription polymerase chain reaction for sequencing. They were classified into genotype GI.3 by phylogenetic analysis. This is the first report of an outbreak associated with sapovirus GI.3 in Korea.
Asunto(s)
Infecciones por Caliciviridae/diagnóstico , Gastroenteritis/diagnóstico , Sapovirus/aislamiento & purificación , Infecciones por Caliciviridae/epidemiología , Infecciones por Caliciviridae/virología , Niño , Brotes de Enfermedades , Femenino , Gastroenteritis/epidemiología , Gastroenteritis/virología , Genotipo , Humanos , Masculino , Filogenia , ARN Viral/análisis , República de Corea/epidemiología , Estudios Retrospectivos , Sapovirus/clasificación , Sapovirus/genética , Instituciones AcadémicasRESUMEN
NADPH-cytochrome P450 reductase (CPR) transfers electrons from NADPH to cytochrome P450, and catalyzes the one-electron reduction of many drugs and foreign compounds. Various forms of spectrophotometric titration have been performed to investigate the electron-accepting properties of CPR, particularly, to examine its ability to reduce cytochrome c and ferricyanide. In this study, the reduction of 1,1-diphenyl-2-picrylhydrazyl (DPPH) by CPR was assessed as a means of monitoring CPR activity. The principle advantage of DPPH is that its reduction can be assayed directly in the reaction medium by a continuous spectrophotometry. Thus, electrons released from NADPH by CPR were transferred to DPPH, and DPPH reduction was then followed spectrophotometrically by measuring A(520) reduction. Optimal assay concentrations of DPPH, CPR, potassium phosphate buffer, and NADPH were first established. DPPH reduction activity was found to depend upon the strength of the buffer used, which was optimal at 100 mM potassium phosphate and pH 7.6. The extinction coefficient of DPPH was 4.09mM(-1) cm(-1). DPPH reduction followed classical Michaelis-Menten kinetics (K(m) = 28 microM, k(cat) = 1690 min(-1)). This method uses readily available materials, and has the additional advantages of being rapid and inexpensive.