Kamran Kaveh

Nutrition and immunity: the effects of the combination of arginine and tryptophan on growth performance, serum parameters and immune response in broiler chickens challenged with infectious bursal disease vaccine.

To explore the effects of the combination of tryptophan (Trp) and arginine (Arg) on growth performance, serum parameters and immune response of broiler chickens challenged with intermediate plus strain of infectious bursal disease virus vaccine, an in vivo experiment was conducted. A corn–soybean meal-based diet containing different levels of Arg and Trp was used. Cobb500 male broiler chickens from 0 to 49 days of age were subjected to a diet supplemented with the combination of Trp and Arg. Growth performance parameters and serum parameters were measured at 27 and 49 days of age. To evaluate the immunomodulatory effects of the combination of Trp and Arg on the challenged chickens, we measured the serum levels of interferon-α, interferon-γ and immunoglobulin G at 27, 35, 42, and 49 days of age. The results showed that the three evaluated immune system parameters including interferon-α, interferon-γ and immunoglobulin G were significantly enhanced after treatment. This enhancement resulted in the recovery of infectious bursal disease virus-infected chickens compared with controls as confirmed by histopathological examinations. Moreover, serum parameters such as albumin and total protein increased, whereas the treatment decreased (P<0.05) the feed:gain ratio, aspartate amino-transferase, alkaline phosphatase, lactic dehydrogenase, triglyceride and cholesterol. These findings suggest that the combination of Arg and Trp has a regulatory effect on growth performance. Moreover, it modulates the systemic immune response against infectious bursal disease.

Repair of compact bone critical sized defect with bone tissue engineering in rabbits

The study was conducted to investigate the effect of bone tissue engineering comprised of combination of bone marrow-derived osteoblasts and corticocancellous bone graft in repairing 15 mm compact bone critical sized defect. Implant of corticocancellous bone graft alone served as group I. For the second group, bone marrow-derived osteoblasts seeded into scaffold of corticocancellous bone graft and the third group with no treatment served as the control group. Rabbits were euthanized on the fifth (only in group II) and the eighth week (all groups) postoperative. Radiographs were taken on the weekly interval. After euthanasia at the fifth and eighth weeks, the implants were harvested for, gross, histology and scanning electron microscope observations. In group I, new bone formation was only observed at the margin of defect and in the defect centre, hypertrophied chondrocytes was detected and major bone formation pattern was creeping substitution. New bone formation at margin of defect and osteogenesis at the centre were observed in the animals of group II, and the bone formation pattern included osteogenesis, osteoconduction, and osteoinduction. The most important finding of the control group was fibroblasts. The tissue engineering bone graft constructed by autogenous bone marrow-derived osteoblasts and corticocancellous bone graft was better than the graft alone in bone formation capability.