Background:Liver lesions in cattle not only have negative effects on the cattle breedingindustry, but also lead to loss of animal protein production, and in particularto endanger the consumers’ health. OBJECTIVES:This study was carried out to examine the macroscopic and histopathologiclesions of liver in slaughtered cattle of Zabol City. METHODS:Livers of 281 cattle slaughtered at the industrial slaughterhouse of Zabol Citywere collected from March to September 2015 for gross and microscopicinvestigation. Tissue processing was conducted from specimens inspected totissue lesions with routine protocol and histopathological changes of liverswere examined under light microscopy. RESULTS:Macroscopic investigation of 281 cases showed 90 livers (32.02%) with gross lesions.In histopathological examination, there were 83 cases (29.53%) withhydatidosis, 3 cases (1.07%) with fasciolosis, 2 cases (0.71%) withperihepatitis and 2 cases (0.71%) with lipidosis.                                                                              CONCLUSIONS:Based on the results of this study, the most frequent liver lesion in cattleslaughtered in Zabol City was hydatidosis indicating the active life cycle of Echinococcusguanulosus and the outbreak of this parasitic disease in dogs and othercarnivores in Sistan region

BACKGROUND: Considering widely administration of methylphenidate and also its immunosuppressive effects on different organs, importance of related microscopic studies is obvious. OBJECTIVES: Determining histological effects of methylphenidate on adrenal glands and lymphatic organs in mice. METHODS: A total number of 30 adult male Balb/C mice were provided, weighed and divided into one control and two experimental groups. The control group received water by gavages once a day, for 40 days. The experimental groups were orally administered MPH hydrochloride (2mg/kg and 10mg/kg body weight,) respectively. Animals were anesthetized and blood samples were collected through cardiac puncture for analysis of blood cells. Spleen, thymus, lymph nodes and adrenal glands were removed and processed for microscopic studies through hematoxylin and eosin staining. Spleen samples were processed for plasma cell count and staining (label antibody CD138*). The data were analyzed using analysis of variance (ANOVA) and p