ABSTRACT. Mechanical stretch affects the healing and remodeling process of the anterior cruciate ligament (ACL) after surgery in important ways. In this study, the effects of mechanical stress on gene expression of type I and III collagen by cultured human ACL cells and roles of transforming growth factor (TGF)-β1 in the regulation of mechanical strain-induced gene expression were investigated. Uniaxial cyclic stretch was applied on ACL cells at 10 cycles/min with 10% length stretch for 24 h. mRNA expression of the type I and type III collagen was increased by the cyclic stretch. TGF-β1 protein in the cell culture supernatant was also increased by the stretch. In the presence of anti-TGF-β1 antibody, stretch-induced increase in type I and type III mRNA expression was markedly ablated. The results suggest that the stretch-induced mRNA expression of the type I and type III collagen is mediated via an autocrine mechanism of TGF-β1 released from ligament cells.

These results demonstrating a higher therapeutic effect of naltrexone in Korean alcohol-dependent individuals with the Asp40 variant genotype than the Asn40 genotype are consistent with previous study results in individuals of European descent. This is the first study to examine the pharmacogenetics treatment response to naltrexone in non-European subjects.

Headless compression screw fixation of fifth metatarsal Jones fractures provided excellent results, allowing athletes to return to full activity without both screw insertion site irritation and clinical refracture.

Background:Although anterior cruciate ligament (ACL) reconstruction techniques that preserve remnant tissues have been described, complete preservation may be difficult, with little known about its clinical advantages.Purpose:To compare clinical outcomes in patients undergoing ACL reconstruction with and without ACL remnant preservation.Study Design:Case-control study.Methods:Of 372 patients who underwent surgical treatment of an ACL injury between September 2006 and July 2010, 154 had no remaining identifiable ligament tissue and were excluded from this study. Attempts were made to preserve the ACL remnant as much as possible in the remaining 218 patients. These patients were divided into 2 groups: those in whom the remnant was preserved (group 1, n = 85) and those in whom the remnant was not preserved (group 2, n = 98). Patients were followed for at least 24 months. Outcomes, including graft rupture, were compared in the 2 groups.Results:Time from injury to surgery was significantly shorter (7.3 ± 16.3 vs 16.0 ± 30.3 months; P < .05) and the preinjury Tegner activity was significantly higher (7.6 ± 1.4 vs 7.1 ± 1.2; P < .05; 95% confidence interval, 1.2-13.7) in group 1 than in group 2. The postoperative negative ratio of the pivot-shift test was similar in the 2 groups (87% vs 81%). Anterior stability of the knee, as measured by a KT-2000 arthrometer, was significantly better in group 1 than in group 2 (1.0 ± 0.8 vs 1.3 ± 1.0 mm; P < .05). ACL graft rupture occurred in 1 patient (1.1%) in group 1 and in 7 patients (7.1%) in group 2 (P < .05). Regression analysis showed that preservation of the remnant decreased the likelihood of graft rupture (odds ratio, 11.2; 95% confidence interval, 1.2-101.7).Conclusion:These findings confirmed that preserving the remnant tissue of the ACL may facilitate recovery of function and decrease graft rupture after primary reconstruction.

These results suggest that having one or two copies of the A118G allele is common among Koreans and may be an important genetic factor in the etiology of alcohol dependence and the frequency of alcohol consumption.