Relative frequency of norovirus infection in children with acute gastroenteritis.

AIM: The aim of this study was to determine the prevalence of norovirus among children with acute gastroenteritis in 2009 and 2010. We also aimed that, to detecting the possible clinical and laboratory differences among cases in 2009 and 2010. METHODS: Fecal samples were collected from children under 16 years of age who were admitted for acute gastroenteritis. Norovirus was detected using immunochromatography. For the comparison of seasonal distribution, clinical manifestations, and laboratory results between cases, we divided subjects into two groups by year. RESULTS: Norovirus infection was detected in 112 of the 1027 collected samples (10.9%). In three cases with norovirus, other enteric viruses like rotavirus and adenovirus are detected concurrently, and these were excluded. After the exclusion of three cases with co-infections, statistical analysis was made in 109 cases. Most of the positive cases were between 1-24 months of age (N.=75, 67%). The rate of norovirus infection peaked in winter in 2010 (P<0.05). However, the rates were not significantly different between seasons in 2009 (P>0.05). We did not detect any positive cases in late summer and autumn in 2010. Diarrhea (97.2%), vomiting (95.4%), and abdominal pain (65.1%) were most frequently encountered symptoms of patients with norovirus. Leukocytosis and neutrophilia were significantly higher in 2010 than 2009 (P<0.05). CONCLUSION: The prevalence and clinical characteristics of norovirus in our study group is similar but seasonal distribution is different between two years. Most of the cases were <24 months of age. Like rotavirus, norovirus vaccine can be developed to prevent infection.

Incidence assessment of rotavirus and adenovirus associated acute gastroenteritis cases in early childhood.

This study was undertaken to give an insight into the incidence of acute gastroenteritis cases of rotaviral/adenoviral aetiology in patients presenting to the emergency room of an inner-city government teaching hospital. Group A rotavirus and adenovirus serotype 40-41 antigen results were obtained via immunochromatography. In 2007, there were 1543 patients with gastroenteritis between 0-5 years of age whose stool samples were tested for rota and adenovirus, of whom 386 (25%) had positive stool samples for rotavirus, and 133 (8.6%) for adenovirus serotype 40-41. The majority of rotavirus (74.6%) and adenovirus (73%) cases were between 0-2 years of age. The peak season for rotavirus gastroenteritis was January (44%) and February (50.6%), whereas July (9.7%) and August (9%) were months of low incidence. For enteric adenoviral infections summer was the peak season, with August (20.9%) and July (17.3%) being the foremost months. Among the viral gastroenteritis cases, rotavirus infections were in the majority. A seasonal trend emerges for viral gastroenteritis: Rota virus infections are most frequently seen in winter whereas adenoviral infections prefer summer months. Both viruses mostly affect children up to 2 years.

Induction of muscle weakness by local inflammation: an experimental animal model.

OBJECTIVE AND DESIGN: The objective of this study was to characterize the response of skeletal muscle to a localized inflammation induced by the inflammatory agent casein. METHODS: An inflammatory agent, casein, was injected into the right hindlimb and saline was injected into the left hindlimb of normal adult mice, once daily for six consecutive days. Inflammatory response was monitored by immunohistochemical labeling of leukocytes. Muscle protein levels were determined by electrophoresis and muscle function was determined by isometric force measurements. RESULTS: Local inflammation was induced by casein in association with the accumulation of extensive neutrophils and macrophages in the soleus muscle. This local inflammation resulted in a shift in myosin heavy chain (MHC) isoform expression and a significant reduction in total MHC concentration in the soleus. Maximal twitch and tetanic forces were significantly reduced in the inflamed soleus. Contractile function in soleus was fully restored after two weeks of recovery, along with the restoration of protein concentration and the disappearance of inflammatory cells. CONCLUSION: This study establishes a unique and robust model in which mechanisms of local inflammation induced muscle protein degradation, reduction of contractile force, and subsequent recovery from this condition can be further studied.

Acute effects of escalating doses of amiodarone in isolated guinea pig hearts.

Cardiac effects of escalating concentrations of amiodarone were determined on isolated perfused guinea pig hearts (Langendorff preparations). Spontaneously beating hearts were instrumented for the measurement of RR, PQ, QRS, QT and QTc durations (from a bipolar electrogram), and dP/dtmax and dP/dtmin from an isovolumetric left ventricular pressure curve. Ten hearts were exposed to escalating concentrations of amiodarone (10-7, 10-6, 10-5 and 10-4 M) in dimethyl sulfoxide (DMSO)/Krebs-Henseleit or to DMSO/Krebs-Henseleit (vehicle). Measurements were collected during the last minute of a 15-min concentration. Means of all parameters were compared by ANOVA with repeated measures design. When compared with vehicle, amiodarone prolonged QT and QTc durations at concentrations >10-6 M. The apparent lengthening of RR, PQ and QRS at concentrations >10-6 M did not achieve statistical significance. Similarly, the apparent decreases in dP/dtmax and dP/dtmin at concentrations >10-6 M did not achieve statistical significance. The putative therapeutic concentration of amiodarone is between 2 and 4 x 10-6 M. In this study, at a concentration of 10-6 M, only RR and dP/dtmin tended to change, but they were not different from vehicle. Thus, amiodarone in this preparation has little potential for cardiac toxicity at therapeutic concentrations.

Effects of chronic, oral amiodarone on left ventricular pressure, electrocardiograms, and action potentials from myocardium in vivo and from Purkinje fibers in vitro.

Left ventricular pressure, electrocardiograms, and action potentials from myocardium and Purkinje fibers were recorded from five untreated controls and five dogs given amiodarone at 25 mg/kg every 12 hours for 4 weeks, followed by 25 mg/kg once daily for an additional 6 weeks. QT interval and action potential duration were more prolonged following treatment with amiodarone, but there were no significant changes in Purkinje fibers except that automaticity was suppressed. This study demonstrated that amiodarone given orally for 10 weeks to healthy dogs lengthens action potential duration of myocardium but has no effect on Purkinje fibers or heart rate variability. This is contrary to previous reports of dogs given amiodarone at a lower dose and for shorter times.

Hemodynamic and electrocardiographic effects of graded doses of amiodarone in healthy dogs anesthetized with morphine/alpha chloralose.

This research was designed to study acute hemodynamic and electrocardiographic effects of amiodarone and to determine an IV dose of amiodarone that minimally affects left ventricular function and does not increase the tendency for ventricular arrhythmia.