Brain and pituitary-adrenal lesions of Trypanosoma brucei brucei and Trypanosoma congolense infections in the West African Dwarf rams: Is trypanotolerance overrated?

Trypanosomosis of the West African Dwarf (WAD) sheep is often neglected due to emphasis on trypanotolerance. Nevertheless, significant pathological changes may occur in tissues of infected WAD sheep. The purpose of this study was to evaluate the brain, pituitary, and adrenal lesions of Trypanosoma brucei brucei (Tbb) and Trypanosoma congolense (Tc) infections in WAD rams. Fifteen WAD rams were infected intraperitoneally with Tbb or Tc (106 trypanosomes/animal) or were uninfected controls (5 rams per group). Adrenocorticotrophic hormone (ACTH) and cortisol were assayed in serum by enzyme immunoassay technique. The brain, pituitary, and adrenal glands were processed for histopathology. Serum ACTH levels of infected rams were significantly (P < .05) higher than that of controls on days 14 and 70 post infection (PI). Serum cortisol levels of infected rams were significantly (P < .05) higher than that of controls only on day 14 PI. Mortality was 60% in Tbb- and 40% in Tc-infected rams. The brain of the infected groups showed chromatolysis of cortical neurons and Purkinje cells with severe encephalitis. Degenerative, necrotic, and inflammatory changes were seen in the pituitary and adrenal glands of the infected rams. Adrenal corticomedullary ratio was significantly (P < .05) higher in Tc-infected rams than controls. Based on the high mortality levels, likely due to severe encephalitis, the WAD sheep may not be regarded as trypanotolerant.

The Effects of Silymarin on Acetaminophen-Induced Acute Hepatic and Renal Toxicities in Domestic Pigeons (Columba livia).

This study evaluated the effects of silymarin on acetaminophen-induced acute liver and kidney toxicities in domestic pigeons (Columba livia). Standard colorimetric methods with commercial kits were used to measure the serum activities or levels of biomarkers associated with liver and kidney damage, such as aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, urea, uric acid, total protein, albumin, and total cholesterol, in 21 pigeons randomly assigned into 3 groups (A, B, and C). Groups A and B were administered acetaminophen 3000 mg/ kg PO q24h at the beginning of the experiment (hour 0). Group B pigeons were further treated with silymarin 35 mg/kg, starting at 12 hours after acetaminophen exposure (post-AA), with the silymarin treatment continuing q12h for 3 days. Group C pigeons served as the control group and were given tap water as the placebo. Blood was collected from the pigeons at hours 0, 12, 24, 48, and 72 of the experiment for serum biochemistry analyses. The results showed that treatment of group B pigeons with silymarin decreased the serum levels of aspartate aminotransferase, alanine aminotransferase, urea, and uric acid compared with the untreated control (group A). It also prevented decreases in serum alkaline phosphatase, total protein, albumin, and cholesterol seen in Group A. Mortality, which was 86% in the untreated control (group A), was completely prevented in group B. It was concluded that silymarin remediated the effects of acetaminophen-induced acute toxic liver and kidney injuries, which may result in pigeon mortality.