Murat Dabak

Background: Extrarenal 1α,25-dihydroxyvitamin D3 (1,25-D) locally produced by immune cells plays crucial roles on the regulation of the immune system. However, in vivo status of extrarenal 1,25-D and 25- hydroxyvitamin D (25-D) in acute inflammatory conditions are unknown. Objective: The aim of this study was to determine extrarenal 1,25-D level in circulation in bilaterally nephrectomized rats induced by low-dose lipopolysaccharide (LPS). Methods: Renal 1,25-D synthesis was terminated through bilateral nephrectomy in rats. The rats received intraperitoneal LPS (50 µg/kg BW) three times and the experiment was ended 24 hours after nephrectomy. Serum 1,25-D, 25-D, calcium, phosphorus, intact parathyroid hormone and calcitonin levels were measured and immunohistochemistry were applied to detect the sources of extrarenal 1,25-D synthesis. Results: Circulatory 1,25-D concentration remarkably increased in the both LPS-treated and non-treated bilaterally nephrectomized rats. Elevated circulatory 1,25-D didn’t have hypercalcemic endocrinal effects. Increased 1,25-D level also resulted in concurrent rapid and dramatic depletion of circulatory 25-D. Conclusions: In conclusion, extrarenal 1,25-D could enter into the systemic circulation and therefore, might have systemic effects besides its autocrin and paracrine functions.

The diagnosis of previous cases of feline tuberculosis in Turkey has been made based solely on pathological changes without isolation of the causative agent. This case report details the first case of feline tuberculosis in Turkey for which the causative agent (Mycobacterium bovis) was confirmed with microbiological isolation, morphological evaluation, molecular (PCR) characterization and antibiotic sensitivity. Systemic tuberculosis was diagnosed via postmortem examination of a 5-year-old stray male cat. Mycobacterium bovis was isolated from the lungs, bronchial and gastrointestinal lymph nodes, kidney and liver. The isolate was defined as M. bovis using the Genotype MTBC assay (Hain Lifescience, Germany), which allows differentiation of species within the Mycobacterium tuberculosis complex with an easy-to-perform reverse hybridization assay. Pathological changes were characterized by multifocal to coalescing granulomatous inflammation in the lungs, liver, lymph nodes and kidneys. Further pathological changes included severe, diffuse, hepatocytic atrophy, periportal fibrosis with lymphohistiocytic infiltration, multifocal lymphohistiocytic interstitial nephritis, mild focal pulmonary anthracosis and mild renal and hepatic amyloidosis. Infection by immunosuppressive viral pathogens including feline herpes virus-1, feline immunodeficiency virus and feline parvovirus virus were ruled out by polymerase chain reaction assay (PCR). The isolated mycobacteria were susceptible to isoniazid, ethambutol, rifampicin or streptomycin. Disseminated M. bovis is a rare infection in cats. Involvement of submandibular lymph nodes suggested that primary transmission might have been the oral route in the present case.

The aim of the present study was to determine the vitamin D status in cattle with malignant catarrhal fever (MCF). Twelve cattle diagnosed as MCF and 6 healthy cattle (controls) were used in the study. Serum 1,25-dihydroxyvitamin D₃ (1,25-D), 25-hydroxyvitamin D₃ (25-D), calcium, phosphorus and parathyroid hormone (PTH) levels were determined as 96.83 pg/ml, 30.0 ng/ml, 2.19 mmol/l, 1.57 mmol/l and 15.21 pg/ml in MCF group and 42.33 pg/ml, 37.0 ng/ml, 2.43 mmol/l, 1.96 mmol/l and 36.08 pg/ml in controls, respectively. Although serum 1,25-D level in the MCF group was increased (P<0.01), serum calcium (P<0.01) and PTH (P<0.05) levels were decreased compared to the controls. The results suggest that there might be an interaction between vitamin D status and MCF.