Biomedical subjects

Min Tian

Publications and source records attributed to Min Tian.

4 recordsLinked to original sources

PubMed2007

Arthroscopic single-bundle reconstruction of posterior cruciate ligament with quadrupled hamstring tendon.

OBJECTIVE: To evaluate the technique and outcome of arthroscopic single-bundle reconstruction of posterior cruciate ligament (PCL) with quadrupled hamstring tendon. METHODS: From April 2001 to October 2004, 49 knees with PCL tears in 49 patients were verified with arthroscope in this department. Of them, 13 were combined with anterior cruciate ligament tears, 14 with disruptions of the posterolateral corner, 6 with ruptures of the posteromedial corner and medial collateral ligament, 9 with lateral meniscus tears, 5 with medial meniscus tears and 2 with popliteal vascular tears. All the damaged PCLs were reconstructed with single-bundle of autogenous quadrupled hamstring tendons under arthroscope. Biodegradable interference screws or blunt titanium interference screws were used for direct anatomic fixation of the reconstructed ligament. RESULTS: After operation, no severe complications occurred at early stage in the 49 patients. All of them were followed up for 10-52 months with an average of 22.0 months+/-10.7 months. Lysholm score was remarkably improved from 30-60 (mean: 47.96+/-8.16) preoperatively to 70-95 (mean: 89.08+/-6.10) at the last postoperative follow-up (P less than 0.01). Furthermore, there was a significant improvement in International Knee Documentation Committee (IKDC) score from abnormal (Grade C) in 10 knees and severely abnormal (Grade D) in 39 preoperatively to normal (Grade A) in 20, nearly normal (Grade B) in 24 and abnormal in 5 at the last follow-up. Of the 49 patients, 40 returned to the same activity level as before and 9 were under the level. CONCLUSIONS: Single-bundle reconstruction of PCL with quadrupled hamstring tendons has the advantage of minimal trauma in surgery and satisfactory outcome.

Adolescent↗

PubMed2006

Multiple-ligament injured knee.

OBJECTIVE: To explore the clinical characteristic of the multiple-ligament injured knee and evaluate the protocol, technique and outcome of treatment for the multiple-ligament injured knee. METHODS: From October 2001 to March 2005, 9 knees with combined anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) tears in 9 patients were identified with clinical and arthroscopic examinations. Of them, 5 knees were combined with ruptures of posteromedial corner (PMC) and medial collateral ligament (MCL), 4 with disruptions of posterolateral corner (PLC), 2 with popliteal vascular injuries and 1 with peroneal nerve injuries. Six patients were hospitalized in acute phase of trauma, 2 received repairs of popliteal artery and 4 had repairs of PMC and MCL. Reconstructions of ACL and PCL with autografts under arthroscope were performed in all patients at 4 to 10 weeks after trauma, including reconstruction of PLC with the posterior half of biceps femoris tendon tenodesis in 4 patients and reconstructions of PMC and MCL with femoral fascia in 1 patient. RESULTS: No severe complications occurred at early stage after operation in the 9 patients. All of them were followed-up for 10-39 months with an average of 23.00 months+/-9.46 months. Lysholm score was 70-95 with an average of 85.00+/-8.29. International Knee Documentation Committee (IKDC) score was from severely abnormal (Grade D) in 9 knees at initial examination to normal (Grade A) in 2 knees, nearly normal (Grade B) in 6 knees and abnormal in 1 knee at the last follow-up. Of the 9 patients, 7 returned to the same activity level before injury and 2 were under the level. CONCLUSIONS: The multiple-ligament injured knee with severe instability is usually combined with other important structure damages. Therefore, careful assessment and treatment of the combined injuries are essential. Reconstructions of ACL and PCL under arthroscope, combined with repairs or reconstructions of the extraarticular ligaments simultaneously or in stages, have advantage of minimal trauma in surgery and satisfactory outcome.

Adult↗

PubMed2005

Sphingosine-1-phosphate agonists increase macrophage homing, lymphocyte contacts, and endothelial junctional complex formation in murine lymph nodes.

The sphingosine-1-phosphate (S1P) receptor agonist, phosphorylated FTY720 (FTY-P), causes lymphopenia, lymphocyte sequestration in mesenteric lymph nodes (MLNs), and immunosuppression. Using multiple techniques to analyze MLN cells harvested from mice treated with S1P receptor agonists, we saw a redistribution of lymphocytes out of nodal sinuses and an expansion of follicles. Although changes in circulating monocytes were not observed with overnight exposure to FTY720, we saw a significant increase in S1P receptor 1 (S1P1)-expressing CD68+ macrophages in subcapsular sinuses of FTY-P-treated MLNs. This was confirmed by quantitative analysis of F4/80+ cells in MLN suspensions. The sinus volume and number of S1P1-positive cells within sinuses were also increased by FTY-P. High endothelial venules and lymphatic endothelium expressed high levels of S1P1, and treatment with FTY-P resulted in intense staining and colocalization of CD31, beta-catenin, and zona occludens 1 in junctions between sinus cells. Transmission electron microscopy showed that FTY-P greatly reduced lymphocyte microvilli and increased cell-cell contacts in the parenchyma. Immunoelectron microscopy revealed that intranodal lymphocytes lacked surface expression of S1P1, whereas S1P1 was evident on the surface and within the cytoplasm of macrophages, endothelial cells, and stromal cells. This subcellular pattern of intranodal receptor distribution was unchanged by treatment with FTY-P. We conclude that S1P1 agonists have profound effects on macrophages and endothelial cells, in addition to inducing lymphopenia.

Animals↗

PubMed2003

Downregulation of electroacupuncture at ST36 on TNF-alpha in rats with ulcerative colitis.

AIM: To investigate the regulatory effect of electroacupuncture (EA) at Zusanli (ST36) on tumor necrosis factor-alpha (TNF-alpha) in rats with ulcerative colitis (UC), and further elucidate the therapeutic mechanism of EA on UC. METHODS: Thirty-two male Sprague-Dawley (SD) rats were randomly divided into four groups (n=8): normal control group; UC control group; UC+ST36 group and UC+non-acupoint group. A solution containing ethanol and 2,4,6-trinitrobenzenesulfonic acid (TNBS) was instilled into the distal colon in the rat (at a dose of 100 mg/kg) to set up UC rat model. Rats in wakefulness state of UC+ST36 group were stimulated at ST36 by EA once a day, while those of UC+non-acupoint group were done at 0.5 cm beside ST36. After 10 d treatment, all rats were sacrificed simultaneously. Colon musocal inflammation and damage were assessed by measuring colon mass, morphologic damage score, colonic myeloperoxidase enzyme (MPO) activity, serum TNF-alpha and colonic TNF-alpha mRNA level. Morphologic damage score was examined under stereomicroscope. Colonic MPO activity was measured by spectrophotometer method. Serum TNF-alpha concentration was determined by radioimmunoassay (RIA). Colonic TNF-alpha mRNA expression level was analyzed by semiquantitative reverse transcription polymerase chain reaction (RT-PCR). RESULTS: Ratio of colonic mass/body mass (m(C)/m(B)) and activity of colonic MPO (microkat/g tissue) markedly increased (8.5+/-2.6 vs 2.5+/-0.4; 145+/-25 vs 24+/-8, P<0.01 vs normal control group). Compared with normal control rats, serum TNF-alpha and colonic TNF-alpha mRNA level in UC control group were increased 2.5 fold (2 278+/-170 vs 894+/-248, P<0.01) and 4.3 fold (0.98+/-0.11 vs 0.23+/-0.11, P<0.01), respectively. After EA at ST36, m(C)/m(B) and MPO activity were reduced significantly (5.3+/-2.0 vs 8.5+/-2.6; 104+/-36 vs 145+/-25, P<0.01, 0.05) compared with those of UC control group. Serum TNF-alpha and colonic TNF-alpha mRNA level were inhibited by EA stimulation at ST36 (P<0.01). The inhibitory rate was 16 % and 44 %, respectively. Morphologic damage score was also increased markedly in rat with UC (P<0.01), whereas it was decreased by EA at ST36 (P<0.05). There was no significant difference between UC control group and UC+EA at non-acupoint (P>0.05). Furthermore, these parameters were highly correlated with each other (P<0.01). CONCLUSION: Serum TNF-alpha concentration and colonic TNF-alpha mRNA expression level are increased significantly in UC rats in correlation with the severity of disease. It indicates that TNF-alpha is closely involved in the immune abnormalities and inflammatory responses in UC. EA at ST36 has therapeutic effect on UC by downregulating serum TNF-alpha and colonic TNF-alpha mRNA expression. High levels of TNF-alpha and its corresponding mRNA expression seem to be implicated in the pathogenesis of UC.

Animals↗