Anatomical distribution of spontaneous iron pigment overload in the liver of han wistar and sprague-dawley rats

The authors performed a retrospective study to determine and describe the incidence of spontaneous pigment overload in the liver of control Han Wistar and Sprague-Dawley rats. Data was collected from 1170 control animals (550 Han-Wistar and 620 Sprague-Dawley) from control dose groups from long term regulatory studies (104-week carcinogenicity studies). Further 628 control animals (300 Han-Wistar and 328 Sprague-Dawley) from control dose groups from short term regulatory studies (13-week and 4 weeks studies) evaluated at the authors’ laboratory between 2009 and 2011. Livers from Han Wistar and Sprague-Dawley rats were re-evaluated using special stains to identify the nature of the pigments. In the periportal hepatocytes and in scattered sinusoidal Kupffer cells, the predominant pigment was identified as haemosiderin and a diagnosis of spontaneous iron overload was made. A comparison between the two strains revealed higher incidences of iron overload in Han Wistar rats than Sprague-Dawley rats. A significant sex difference was observed in both strains but was greater in Han Wistar rats. An age-related increase in the incidence and severity of pigment deposition was also apparent. Since there is little compiled data on spontaneous pigment overload in the liver the aim of this report was to summarize and discuss the incidence, distribution and factors affecting the occurrence of this background finding in control rats on toxicity studies

A ventricular septal defect in a juvenile ostrich (Struthio camelus): A case report

(Zimbabwe Veterinary Journal, 2001, 32 (3&4): 76-80

Pathological findings in broiler chickens with malabsorption syndrome in Zimbabwe

A year-long study of pathological manifestations in broiler chickens with the malabsorption syndrome (MAS) was undertaken. A total of 52 cases comprising 368 chickens including formalin-fixed specimens were analysed. Gross and microscopic lesions were common in the pancreas and the intestines. Over 80% of the birds had pancreatic lesions characterised by fibrosis, while 75% had thin, dilated and mucus-filled intestines associated with villi sloughing and cellular infiltration in the duodenum and goblet cell hyperplasia in the jejunum. The severity of stunting was associated with intestinal bacterial infections, management systems, and the time during the course of the study period. Severe stunting and rickets were present during the first quarter of the study period, suggesting a vertical transmission during that period, while milder stunting was seen as the disease incidence subsided, suggesting a horizontal transmission and a gradual build-up of immunity by broiler parents

Myocarditis, Disseminated Infection, and Early Viral Persistence Following Experimental Coxsackievirus B Infection of Cynomolgus Monkeys

Coxsackievirus B (CVB) infection is a common cause of acute viral myocarditis. The clinical presentation of myocarditis caused by this enterovirus is highly variable, ranging from mildly symptoms to complete hemodynamic collapse. These variations in initial symptoms and in the immediate and long term outcomes of this disease have impeded development of effective treatment strategies. Nine cynomolgus monkeys were inoculated with myocarditic strains of CVB. Virological studies performed up to 28 days post-inoculation demonstrated the development of neutralizing antibody in all animals, and the presence of CVB in plasma. High dose intravenous inoculation (n = 2) resulted in severe disseminated disease, while low dose intravenous (n = 6) or oral infection (1 animal) resulted in clinically unapparent infection. Transient, minor, echocardiographic abnormalities were noted in several animals, but no animals displayed signs of significant acute cardiac failure. Although viremia rapidly resolved, signs of myocardial inflammation and injury were observed in all animals at the time of necropsy, and CVB was detected in postmortem myocardial specimens up to 28 days PI. This non-human primate system replicates many features of illness in acute coxsackievirus myocarditis and demonstrates that myocardial involvement may be common in enteroviral infection; it may provide a model system for testing of treatment strategies for enteroviral infections and acute coxsackievirus myocarditis