N4hydroxylation of sulfamethoxazole by cytochrome P450 of the cytochrome P4502C subfamily and reduction of sulfamethoxazole hydroxylamine in human and rat hepatic microsomes. Drug Metab

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Canadian Veterinary Journal 29 9 709 712

Gastrointestinal adenocarcinomas are the most common nonhaematopoietic gastrointestinal tumours in cats. They are highly malignant tumours causing intestinal obstruction due to the annular, stenosing nature to their growth. Current literature is largely based on surveys of pathology records. Therefore, a retrospective study was conducted to evaluate clinical course and prognosis with surgical excision of the tumour. In published reports feline gastrointestinal adenocarcinoma represented 20-35% of gastrointestinal neoplasms in the cat; the average age was greater than ten years; and there was a greater incidence in Siamese than in other breeds. The small intestine accounted for 70% of cases. In this restrospective study, cats usually had a long history of nonspecific gastrointestinal disease; weight loss and vomiting were the most common signs. Abdominal radiographs demonstrated intestinal obstruction, and an abdominal mass was often palpable. With intestinal resection and anastomosis, median survival time was 2.5 months (range: 0-24 months). It is suggested that tubular adenocarcinomas may have a better prognosis than other histological types, especially if metastasis is not present at the time of surgery. A significant disease-free interval is possible in some cases.

American Journal of Veterinary Research 66 12 2065 2072 United States

OBJECTIVE: To determine whether a deficiency in systemic or local (pars intermedia) antioxidant capacity is associated with pituitary pars intermedia oxidative stress and pituitary pars intermedia dysfunction (PPID) in horses. SAMPLE POPULATION: Blood samples from 20 horses with PPID and 20 healthy client-owned horses, archived paraffin-embedded adrenal gland and substantia nigra tissues from 20 horses, and pituitary gland tissue from 16 horses. PROCEDURES: Total glutathione, superoxide dismutase, and glutathione peroxidase activities were determined in RBCs. Accumulation of a systemic marker of oxidative stress (3-nitrotyrosine) was assessed in plasma and formalin-fixed, paraffin-embedded adrenal gland and substantia nigra tissues. Local antioxidants (total and manganese superoxide dismutase, glutathione peroxidase, and total glutathione) were measured in pars intermedia tissues. RESULTS: No significant differences existed in systemic antioxidant enzyme activity or accumulation of 3-nitrotyrosine between horses with PPID and control horses. In pituitary gland tissues, glutathione peroxidase activity was increased in horses with oxidative stress, whereas total glutathione concentration and superoxide dismutase activity remained unchanged. There was an age-associated decrease in manganese superoxide dismutase activity in the pars intermedia. CONCLUSIONS AND CLINICAL RELEVANCE: There was no evidence of systemic accumulation of oxidative stress markers or deficiencies in antioxidant capacity in horses with PPID, suggesting that these are unlikely to be major predisposing factors in the development of PPID. Manganese superoxide dismutase activity in the pars intermedia decreased significantly with increasing age. Role of an age-associated decrease in antioxidant capacity for the pars intermedia in the development of PPID in horses warrants further investigation

Canadian Veterinary Journal 29 8 654 657

Seven dogs with histories of intermittent vomiting and diarrhoea had greatly elevated alkaline phosphatase and alanine aminotransferase activities and total bilirubin concentrations. Exploratory laparotomy in each dog revealed a 3 to 10 cm mass in the body of the pancreas and obstruction of the common bile duct. Three dogs treated with pancreatectomy, gastrojejunostomy, and cholecystojejunostomy died within five weeks. Three dogs treated with conservative surgical procedures were alive 8, 16, and 26 months postoperatively. One dog was killed because of suspected neoplasia. Hepatic enzyme activity and bilirubin levels decreased greatly in the surviving dogs. Histological examination of the pancreatic masses indicated chronic pancreatitis. Hepatic biopsies revealed evidence of cholestasis. It is concluded that chronic pancreatitis should be included in the differential diagnosis of icterus, bile duct obstruction, and masses in the pancreas.