Magnetic resonance imaging-measured bone marrow adipose tissue area is inversely related to cortical bone area in children and adolescents aged 5-18 years.

Previous studies have shown an inverse correlation between bone marrow adipose tissue and bone mineral density in cancellous bone; however, such relationships in cortical bone are less studied, especially in children. A total of 185 healthy children and adolescents (76 females and 109 males, aged 5-18 years) were included in this study. Right femoral bone marrow adipose tissue area (BMA), right femoral cortical bone area (CBA), subcutaneous adipose tissue, visceral adipose tissue, and skeletal muscle were accessed by whole-body magnetic resonance imaging. In regression analysis with CBA as the dependent variable and BMA as the independent variable, BMA negatively contributed to CBA after adjusting for weight and total body fat or subcutaneous adipose tissue, visceral adipose tissue, and skeletal muscle (ß = -0.201 to -0.272, p < 0.001). These results suggest an inverse relationship between BMA and CBA in children and adolescents after adjustment of body weight or body composition. The data support the hypothesis that a competitive relationship exists between bone and marrow fat in cortical bone and is consistent with a similar finding in cancellous bone in previous studies. Future research is needed to clarify the role of marrow fat in childhood fractures that are related to cortical bone quality.

[Animal model and modified technique of orthotopic liver transplantation in rats].

OBJECTIVE: To modify orthotopic liver transplantation method with two-cuff technique. METHODS: On the basis of cuff technique, the donor liver was perfused through the abdominal aorta with 20 ml cold perfusate. The anastomosis of the suprahepatic vena cave(SVC) was sutured end-to-end with 8/0 nylon line, and the continuity of infrahepatic vena cave(IVC) and portal vein(PV) were established by means of cuff method respectively. The bile duct anastomosis was performed by internal stent. RESULTS: Orthotopic liver transplantations were performed in 360 rats. The time for donor operation and liver preparation was (31.2 +/- 5.0) min and (12.0 +/- 3.0) min, and the recipient operative and anhepatic time was (45.0 +/- 5.5) min and (20.0 +/- 2.5) min, respectively. The two-day survival rate was 91.4%. In non-intervention group, one-week survival rate was 86.5%. CONCLUSION: The modified model is easily available and highly reproducible which provides a practical and stable experimental model for the study of liver transplantation.