Biomedical subjects

Sang-Jin Shin

Publications and source records attributed to Sang-Jin Shin.

3 recordsLinked to original sources

PubMed2005

Inhibition of inducible nitric oxide synthase promotes recovery of motor function in rats after sciatic nerve ischemia and reperfusion.

PURPOSE: To investigate the effects of inhibition of inducible nitric oxide synthase (iNOS) on the recovery of motor function in the rat sciatic nerve after ischemia and reperfusion injury. METHODS: A 10-mm segment of the sciatic nerve from 169 rats had 2 hours of ischemia followed by up to 42 days of reperfusion. The animals were divided into 2 groups that received either iNOS inhibitor 1400W or the same volume of sterile water subcutaneously. A walking track test was used to evaluate the motor functional recovery during reperfusion. Statistical analysis was performed for the measurements of the sciatic functional index (SFI) by using 2-way analysis of variance; 1-way analysis of variance was used for the post hoc analysis of specific values at each time point of the SFI measurement. RESULTS: 1400W-treated rats had earlier motor functional recovery than controls, with a significantly improved SFI between days 11 and 28. Histology showed less axonal degeneration and earlier regeneration of nerve fibers in the 1400W group than in the controls. Inducible NOS messenger RNA and protein were up-regulated during the first 3 days of reperfusion but there was a down-regulation of neuronal NOS and up-regulation of endothelial NOS in control animals. 1400W treatment attenuated the increase of iNOS but had no effect on neuronal NOS and endothelial NOS. CONCLUSIONS: Our results indicate that early inhibition of iNOS appears to be critical for reducing or preventing ischemia and reperfusion injury.

Analysis of Variance↗

PubMed2003

Regulation of matrix turnover in meniscal explants: role of mechanical stress, interleukin-1, and nitric oxide.

The meniscus is an intra-articular fibrocartilaginous structure that serves essential biomechanical roles in the knee. With injury or arthritis, the meniscus may be exposed to significant changes in its biochemical and biomechanical environments that likely contribute to the progression of joint disease. The goal of this study was to examine the influence of mechanical stress on matrix turnover in the meniscus in the presence of interleukin-1 (IL-1) and to determine the role of nitric oxide (NO) in these processes. Explants of porcine menisci were subjected to dynamic compressive stresses at 0.1 MPa for 24 h at 0.5 Hz with 1 ng/ml IL-1, and the synthesis of total protein, proteoglycan, and NO was measured. The effects of a nitric oxide synthase 2 (NOS2) inhibitor were determined. Dynamic compression significantly increased protein and proteoglycan synthesis by 68 and 58%, respectively, compared with uncompressed explants. This stimulatory effect of mechanical stress was prevented by the presence of IL-1 but was restored by specifically inhibiting NOS2. Release of proteoglycans into the medium was increased by IL-1 or mechanical compression and further enhanced by IL-1 and compression together. Stimulation of proteoglycan release in response to compression was dependent on NOS2 regardless of the presence of IL-1. These finding suggest that IL-1 may modulate the effects of mechanical stress on extracellular matrix turnover through a pathway that is dependent on NO.

Animals↗

PubMedDate not supplied

Posterolateral rotatory instability treated by a modified biceps rerouting technique: technical considerations and results in cases with and without posterior cruciate ligament insufficiency.

PURPOSE: This study compared the clinical results of modified biceps femoris tenodesis with posterolateral rotatory instability (PLRI) injuries and PLRI combined with PCL injuries. TYPE OF STUDY: Case series. METHODS: Of 46 patients treated for PLRI, 21 had isolated PLRI (group 1), and 25 had PLRI with PCL injuries (group 2). The most common cause of injury was motor vehicle accident. The PCL was reconstructed using an arthroscopic 1-incision technique. The advantages of the modified Clancy technique include fixation of the biceps tendon to the isometric position and reduced surgical damage to the iliotibial band by dissection to the lateral femoral epicondyle through the interval between the iliotibial band and biceps muscle. RESULTS: All knees tested positive in the preoperative reverse pivot shift test, and 43 patients (93%) tested negative postoperatively. The side-to-side difference of an average external rotation thigh-foot angle (ERTFA) at both 30 degrees and 90 degrees of knee flexion was 15 degrees and 11 degrees in group 1 and 21 degrees and 26 degrees in group 2 preoperatively. Postoperative ERTFA tested at 30 degrees and 90 degrees of knee flexion were 10 degrees less than the uninvolved knee in both groups. At a mean follow-up of 40.3 months, the postoperative Lysholm knee score was 93.6 in group 1 and 90.4 in group 2. The postoperative HSS mean value was 91.1 in group 1 and 87.9 in group 2. A correction loss of more than 5 degrees was found in 3 patients of group 1 and in 5 patients of group 2 at an average 12 months after surgery. In 5 of 8 patients, severe scar tissues were found at the insertion site of the biceps tendon to the fibula during surgery. These tissues were associated with damage of the involved structures at the time of injury. CONCLUSIONS: Based on our experience, we recommend the modified biceps tenodesis for the reconstruction of both PLRI injuries and PLRI combined with PCL injuries except in patients with severe damage at the attachment site of the biceps tendon.

Adolescent↗