Canine model of ischemic stroke with permanent middle cerebral artery occlusion: clinical and histopathological findings

The aim of the present study was to assess the clinical and histopathological findings in a canine model of ischemic stroke. Cerebral ischemic stroke was induced by middle cerebral artery occlusion in four healthy beagle dogs using silicone plugs. They showed neurological signs of forebrain dysfunction such as reduced responsiveness, head turning, circling, postural reaction deficits, perceptual deficits, and hemianopsia. These signs gradually regressed within 4 weeks without therapy. On magnetic resonance imaging, T2 hyperintensity and T1 hypointensity were found in the cerebral cortex and basal ganglia. These lesions were well-defined and sharply demarcated from adjacent brain parenchyma with a homogenous appearance. No abnormalities of the cerebrospinal fluid were observed. At necropsy, atrophic and necrotic lesions were observed in the cerebral cortex. The cerebral cortex, basal ganglia, and thalamus were partially unstained with triphenyl-tetrazolium chloride. Histopathologically, typical features of infarction were identified in cortical and thalamic lesions. This study demonstrates that our canine model resembles the conditions of real stroke patients.

The Risk Factors of Cholestasis in Very Low Birth Weight Infants

PURPOSE: This study was aimed to investigate the risk factors of cholestasis in very low birth weight infants (VLBWI). METHODS: The study includes 466 VLBWI admitted to the neonatal intensive care unit at Samsung medical center from November 1994 to January 2003 and the data were collected retrospectively from their medical records. They were divided into two groups; cholestatic group (group 1) and control group (group 2) by level of direct bilirubin at 2.0 mg/dL. RESULTS: The mean gestational age and birth weight were lower in group 1. In group 1, enteral feeding was started later, time to achieve full and near full enteral feeding were delayed and duration of parenteral nutrition was longer than group 2. The incidence of bronchopulmonary dysplasia was significantly higher in group 1, but the incidences of sepsis and necrotizing enterocolitis were not different between the two groups. After adjusting for birth weight and gestational age, logistic regression analysis of the above factors revealed that the factors significantly related to cholestasis were longer duration of parenteral nutrition and longer time to achieve near full enteral feeding. CONCLUSION: Earlier near full enteral feeding and shorter duration of parenteral nutrition decreased the incidence of cholestasis.