No abstract

No abstract

The efficacy of osteogenic protein-1 (OP-1; BMP-7) in regeneration of articular cartilage was examined by creating knee chondral defects in sheep. With a specially designed instrument in both knees, two 10 mm (diameter) chondral defects were created: one in the trochlea and the other on the femoral condyle. The recombinant BMP was delivered via an extra-articulary positioned mini-osmotic pump, which was fixed to the femoral diaphysis above the knee joint, and connected by a polyethylene tubing to the articular space. Prior to use, the compatibility of OP-1 with mini-osmotic pumps was tested in vitro by measuring aggregation/precipitation and modification of the released protein by size exclusion and reversed phase HPLC. The average amount of aggregation was 15% and about 5% of OP-1 was modified. However, the biological activity of OP-1 released from pumps over a period of 2 weeks at 37 degrees C was equal to ROS cell assay OP-1 standard. Following surgery, a total of 55 microg (low dose) or 170 microg (high dose) OP-1 in acetate buffer (pH 4.5) was slowly released from the pump over a period of 2 weeks. The pumps connected to control knees were filled with acetate buffer as a vehicle. Twelve animals were operated, six of which were treated with the low OP-1 dose, and six with the high OP-1 dose. Three sheep of each group were killed either at 3 or 6 months following surgery, based on arthroscopical evaluation. The chondral defects in the control knees remained empty during the observation period. At 3 months following surgery, defects treated with both OP-1 doses were filled with connective tissue and cartilage. At 6 months following surgery, both doses of OP-1 stimulated regeneration in treated knees. The boundaries between new and old cartilage were well fused and mechanically resisted animals' weight bearing. The regenerated cartilage was rich in proteoglycans and type II collagen, as demonstrated by toluidine blue staining and immunohistochemistry. No signs of endochondral bone formation above the bony tidemark were observed. We suggest that a recombinant bone morphogenctic protein stimulates ingrowth of mesenchymal cells into the chondral defects which then transform into newly formed articular cartilage-like tissue.

ABSTRACT:In 16 male dogs who suffered from perineal hernia, polypropylene mesh was used to close a defect in the pelvic diaphragm. Pelvic bone was drilled on the pelvic floor and mesh was sutured through holes by polypropylene suture. Strong pelvic diaphragm, good long-term results and time-sparing by this technique was achieved. Suture sinuses were developed in two dogs one month postoperatively. Objectives of this study were to describe a new alternative technique of perineal herniorraphy and postoperative possible complications. Weakness of internal obturator muscle flap is complication which can be observed during transposition of internal obturator muscle flap. This technique can be used when internal obturator muscle flap is weak like the operation of the first choice.

Background: The aim of this study was to investigate the effect of low-pressure pneumoperitoneum and pentoxifylline, a methylxanthine derivative, in the prevention of injury caused by free oxygen radicals generated during CO₂ pneumoperitoneum. Methods: Twenty-eight rabbits were allocated randomly to 4 groups. Control group rabbits (group 1) were subjected to anesthesia for 60 min; group 2 and 3 animals were subjected to a CO₂ pneumoperitoneum (15 or 7 mm Hg); and group 4 rabbits received 50 mg/kg pentoxifylline, followed by a 15-mm-Hg pneumoperitoneum. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), lipid hydroperoxide, glutathione reductase and total antioxidant status were measured. Results: Compared with group 1, a significant increase in lipid hydroperoxide levels at the end of the pneumoperitoneum and 30 min after deflation and a significant decrease in total antioxidant status 24 h after deflation were recorded in group 2. In addition, a significant increase was observed in ALT, AST and LDH levels. These changes were attenuated by low-pressure pneumoperitoneum, whereas pentoxifylline pretreatment appeared to attenuate only transaminase levels. Conclusion: Low-pressure pneumoperitoneum could attenuate ischemia/reperfusion injury induced by CO₂ pneumoperitoneum in a rabbit model whereas pentoxifylline pretreatment appeared to attenuate only transaminase levels. Pentoxifylline did not prevent the development of oxidative stress.