VP4 and VP7 Genotyping of Group A Rotavirus Isolated from Diarrhea Patients in Seoul by Multiplex PCR

The incidence and distribution of the human rotavirus G types (VP7 associated: G1~G4) and P types (VP4 associated: P[4], P[6], P[8], P[10]) were determined from 89 rotavirus strains isolated from diarrhea patients between 2001 and 2002 using reverse transcription and multiplex polymerase chain reaction. G types were identified from 83 (95.5%) and P types were from 82 (92.1%) strains. The predominant genotypes were P[4]G2 (28.1%) and P[6]G4 (27%) with much lower incidence of genotypes P[10]G1 (1.1%) and P[10]G3 (1.1%). P[9] type was not detected. A significant genotypic shift was observed that P[4] was the most prevalent genotype that accounted for 75% during the spring season of 2001, coinfection with P[4] and P[6] for 17.5%. P[6] increased gradually to account for 53% of the strains analysed in the following 2002 spring season. Mixed G types revealing coinfections G2/G3 and G3/G4 were found at low frequency (2.2%).

Effects of Patent Ductus Arteriosus on Right Ventricle in Premature Infants: by M-mode and Doppler Echocardiography

PURPOSE: Patent ductus arteriosus, derived left to right shunt flows, elevate the pulmonary artery pressure in infants and children and may alter right ventricular afterload thereby right ventricular function. Therefore, we examined the effects of patent ductus arteriosus on the right ventricular systolic time interval in premature infants by non-invasive Doppler echocardiography. METHODS: Tweleve premature infants with patent ductus arteriosus were studied by M-mode and Doppler echocardiography before and after treatment with mefenamic acid. Heart rate (HR), ratio of left atrium/aorta (LA/AO), right ventricular preejection period (RVPEP), right ventricular ejection time (RVET) and right ventricular systolic time interval (RVSTI : ratio of RVPEP/RVET), both corrected or uncorrected for heart rate were measured. RESULTS: After mefenamic acid treatment, in infants showing clinical response, right ventricular preejection period (RVPEP) and right ventricular systolic time intetrval (RVSTI), both corrected or uncorrected for heart rate, decreased significantly following ductal closure (RVPEP : 70.3msecc +/- 14.5 vs 54.3msec +/- 10.9, P<0.01, RVPEPc : 129.2msec +/- 13.5 vs 111.7msec +/- 8.4, P<0.01, RVSTI : 0.38 +/- 0.09 vs 0.28 +/- 0.05, P<0.05, RVSTIc : 0.31 +/- 0.04 vs 0.27 +/- 0.03, P<0.01). CONCLUSION: Premature infants with patent ductus arteriosus exhibit echocardiographic evidence of increased RVSTI as a result of increased right ventricular afterload. This results suggest that we have to make every effort to prevent the ductal reopening or early closure of ductus arteriosus in premature infants.