OBJECTIVE: To evaluate the effect of biodegradable magnesium alloy materials in promoting tendon-bone healing during rotator cuff tear repair and to investigate their potential underlying biological mechanisms. METHODS: Forty-eight 8-week-old Sprague Dawley rats were taken and randomly divided into groups A, B, and C. Rotator cuff tear models were created and repaired using magnesium alloy sutures in group A and Vicryl Plus 4-0 absorbable sutures in group B, while only subcutaneous incisions and sutures were performed in group C. Organ samples of groups A and B were taken for HE staining at 1 and 2 weeks after operation to evaluate the safety of magnesium alloy, and specimens from the supraspinatus tendon and proximal humerus were harvested at 2, 4, 8, and 12 weeks after operation. The specimens were observed macroscopically at 4 and 12 weeks after operation. Biomechanical tests were performed at 4, 8, and 12 weeks to test the ultimate load and stiffness of the healing sites in groups A and B. At 2, 4, and 12 weeks, the specimens were subjected to the following tests: Micro-CT to evaluate the formation of bone tunnels in groups A and B, HE staining and Masson staining to observe the regeneration of fibrocartilage at the tendon-bone interface after decalcification and sectioning, and Goldner trichrome staining to evaluate the calcification. Immunohistochemical staining was performed to detect the expressions of angiogenic factors, including vascular endothelial growth factor (VEGF) and bone morphogenetic protein 2 (BMP-2), as well as osteogenic factors at the tendon-bone interface. Additionally, immunofluorescence staining was used to examine the expressions of Arginase 1 and Integrin beta-2 to assess M1 and M2 macrophage polarization at the tendon-bone interface. The role of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway in tendon-bone healing was further analyzed using real-time fluorescence quantitative PCR. RESULTS: Analysis of visceral sections revealed that magnesium ions released during the degradation of magnesium alloys did not cause significant toxic effects on organs such as the heart, liver, spleen, lungs, and kidneys, indicating good biosafety. Histological analysis further demonstrated that fibrocartilage regeneration at the tendon-bone interface in group A occurred earlier, and the amount of fibrocartilage was significantly greater compared to group B, suggesting a positive effect of magnesium alloy material on tendon-bone interface repair. Additionally, Micro-CT analysis results revealed that bone tunnel formation occurred more rapidly in group A compared to group B, further supporting the beneficial effect of magnesium alloy on bone healing. Biomechanical testing showed that the ultimate load in group A was consistently higher than in group B, and the stiffness of group A was also greater than that of group B at 4 weeks, indicating stronger tissue-carrying capacity following tendon-bone interface repair and highlighting the potential of magnesium alloy in enhancing tendon-bone healing. Immunohistochemical staining results indicated that the expressions of VEGF and BMP-2 were significantly upregulated during the early stages of healing, suggesting that magnesium alloy effectively promoted angiogenesis and bone formation, thereby accelerating the tendon-bone healing process. Immunofluorescence staining further revealed that magnesium ions exerted significant anti-inflammatory effects by regulating macrophage polarization, promoting their shift toward the M2 phenotype. Real-time fluorescence quantitative PCR results demonstrated that magnesium ions could facilitate tendon-bone healing by modulating the PI3K/AKT signaling pathway. CONCLUSION Biodegradable magnesium alloy material accelerated fibrocartilage regeneration and calcification at the tendon-bone interface in rat rotator cuff tear repair by regulating the PI3K/AKT signaling pathway, thereby significantly enhancing tendon-bone healing.
Animals ; Rotator Cuff Injuries/metabolism* ; Rats, Sprague-Dawley ; Signal Transduction ; Wound Healing/drug effects* ; Alloys/pharmacology* ; Rats ; Proto-Oncogene Proteins c-akt/metabolism* ; Rotator Cuff/metabolism* ; Macrophages/metabolism* ; Magnesium/pharmacology* ; Phosphatidylinositol 3-Kinases/metabolism* ; Vascular Endothelial Growth Factor A/metabolism* ; Male ; Biocompatible Materials ; Bone Morphogenetic Protein 2/metabolism*

To summarize the perioperative nursing experience of a patient with thoracic and abdominal aortic dissection aneurysm after Stanford type A aortic dissection surgery,who underwent intra-abdominal aortic aneurysm endovascular isolation,in situ fenestration branch covered stent placement,and artificial blood vessel bypass.The nursing points include regular evaluation of the intra-abdominal pressure of the patient,being on guard against the rupture of the dissection;specialist nurses participated in the preoperative multidisciplinary discussion;establishing an emergency plan for the rescue of ruptured aortic dissection;monitoring the vital signs of patients closely to prevent critical complications during surgery.After multidisciplinary treatment and meticulous care,the patient's surgery went smoothly and the postoperative recovery was good.The patient was discharged 8 days later.

To summarize the perioperative nursing experience of a patient with thoracic and abdominal aortic dissection aneurysm after Stanford type A aortic dissection surgery,who underwent intra-abdominal aortic aneurysm endovascular isolation,in situ fenestration branch covered stent placement,and artificial blood vessel bypass.The nursing points include regular evaluation of the intra-abdominal pressure of the patient,being on guard against the rupture of the dissection;specialist nurses participated in the preoperative multidisciplinary discussion;establishing an emergency plan for the rescue of ruptured aortic dissection;monitoring the vital signs of patients closely to prevent critical complications during surgery.After multidisciplinary treatment and meticulous care,the patient's surgery went smoothly and the postoperative recovery was good.The patient was discharged 8 days later.

Total mesorectal excision (TME) has become the basic principle of surgical treat-ment for middle and low rectal cancer. Some of patients with ultra-low rectal cancer require under-going intersphincteric resection (ISR). Due to the limitation of the narrow pelvis, TME and ISR put forward higher requirements for the precise separation of the anatomical level and the protection of neurological function during the operation. At present, evaluation of the difficulty of surgery for middle and low rectal cancer is mainly based on the subjective judgment of chief surgeon, and there is no unified and objective scoring system or prediction model that can classify the difficulty of surgery for middle and low rectal cancer before surgery. The authors review relevant literatures and summarize the existing studies related to pelvic measurement for predicting the difficulty of surgery for middle and low rectal cancer, in order to provide significant guidance for the selection of surgical approach for patients with middle and low rectal cancer.

A fluorescent microsphere-based immunochromatographic strip test (FICT) was developed for the rapid, sensitive, and quantitative detection of porcine reproductive and respiratory syndrome virus (PRRSV) antibodies at the pen-side. The assay was based on the formation of a sandwich immune-complex (anti-pig IgG-PRRSV antibodies-NSP7/N), which was validated by a comparison with IDEXX-ELISA using 3325 clinical specimens. The diagnostic specificity, sensitivity, and accuracy of FICT were 97.28, 93.41, and 94.95%, respectively. FICT showed a good correlation with the virus neutralization assay. Overall, a promising pen-side diagnostic tool was developed for the rapid and quantitative detection of PRRSV antibodies within 15 min.

Objective To study the correlation between transplanted kidney dysfunction and oc-currence of the panel reactive antibody ( PRA, also referred as anti-HLA antibody ) and anti-Major-Histo-compatibility-Complex class Ⅰrelated chain A (MICA) antibody.Methods The tests for detecting PRA and anti-MICA antibody were performed on 679 renal transplant patients from December , 2009 to June, 2010 who received transplantation before 2008 in Beijing Friendship Hospital .Enzyme-Linked Immunosor-bent Assay ( ELISA) was used to detect anti-HLA antibody using LAT-1240 ( OneLambda Inc .) .MICA Ab-Scan Kit was adopted to detect anti-MICA antibody .Continuous observation of graft function was conducted . Results 108 out of 679 patients showed anti-HLA antibody and/or anti-MICA antibody positive results . Among them, 81 patients were positive only for anti-HLA antibody, 18 patients were positive only for anti-MICA antibody and other 9 patients showed anti-HLA and anti-MICA antibodies double positive .Among all of the kidney transplant patients with a failed or decreased renal function , 71 patients were positive for anti-HLA antibody;16 patients were positive for anti-MICA antibody;and other 9 patients were positive for both anti-HLA and anti-MICA antibodies .The results demonstrated that anti-HLA and anti-MICA antibodies af-fected the renal functions in patient with renal transplantation (χ2 =353.92, P <0.001).Conclusion Anti-HLA and MICA antibodies showed significant positive correlations with chronic allograft failure in the patients with renal transplantation .

Objective To explore the therapeutic effect of erythropoietin (EPO)combined oral iron in patients with chronic congestive heart failure( CHF)accompanied by anemia. MethodsNinety six patients with CHF accompanied by anemia, whom were consecutively hospitalized from January 2007 to December 2009, were enrolled into this study. They were randomly divided into treatment group accepted routine anti-heart failure therapy combined EPO and oral iron, and control group solely accepted routine anti-heart failure therapy. After 6 months follow up, the changes of hemoglobin ( Hb ), cardiac function classification, left ventricular ejection fraction(LVEF) ,6-minute walking distance,readmission rate of CHF and cardiac death were compared between two groups. ResultsCompared with those before therapy, we found significant improvements of hemoglobin level ( [ 120. 12 ± 10. 42 ] g/L vs [ 86.40 ± 14. 30 ] g/L, P ＜ 0. 01 ), cardiac function classification ( 2. 65 ± 0. 67 vs 3. 13 ±0. 61, P ＜ 0. 01 ), LVEF ( [ 37.21 ± 4. 96 ]％ vs [ 33. 92 ± 7. 28 ]％, P ＜ 0. 01 ), 6-minute walking distance ( [ 443.52 ± 97. 39 ] mvs [ 379. 15 ± 59. 34 ] m, P ＜ 0. 01 ) in treatment group after EPO combined oral iron administration. After 6 months follow up, we also found significant improvements of Hb level ( [ 120. 12 ±10. 42 ] g/L vs [ 86. 40 ± 14. 30 ] g/L, P ＜ 0. 01 ), cardiac function classification ( 2.65 ± 0. 67 vs 2. 98 ± 0. 81,P＜0.01),LVEF([37.21 ± 4.96]％ vs [34.67 ±4.10]％,P ＜ 0. 01),6-minute walking distance ( [443.52 ±97. 39 ] mvs [ 379. 15 ± 59. 34 ] m, P ＜ 0. 01 ) in the comparison between treatment and control group. The readmission rate of CHF fell significantly in treatment group compared to control (20. 83％ vs 39. 58％ ,P ＜ 0. 05 ). However, we found no significant difference in cardiac death rate ( 0％ vs 4. 17％, P ＞0. 05). ConclusionTreatment of EPO combined oral iron could significantly improve the cardiac function,increase exercise tolerance,lower the readmission rate of CHF in patients with chronic congestive heart failure (CHF)accompanied by anemia.

Objective To analyze the sensitized factors in urinemia patients who waiting for renal transplantation.Methods 2429 patients with urinemia from April 2002 to December 2008 were subjected to the detection of panel reactive antibody, and classified into 5 groups according to their clinical data:(A) no history disease group (n = 1097) who never experienced transfusion, pregnancy and transplantation; (B) Transfusion group (n = 361) who received transfusion more than 200 ml; (C) Pregnancy group (n = 481) who experienced pregnancy; (D) Transfusion+ pregnancy group (n= 294) who experienced both pregnancy and transfusion; (E) Re-transplantation group (n = 196) who experienced failed transplantation before, and waited for the second renal transplantation.Results All the males in group A were negative for PRA, and females were weakly positive for HLA Ⅱ antibody.The incidence of PRA production in group B was 15.24 % (55/361).Thirty-nine patients were positive for PRA in group C with the incidence being 8.11 % (39/481).The PRA positive rate in groups D and E was 30.61 % (90/294) and 70.92 % (139/196) respectively.PRA intensity was more than 60 % in 72 patients in group E.Conclusion Transfusion and pregnancy caused lower incidence of PRA positive rate.The incidence was much higher in transfusion + pregnancy patients than that in patients with transfusion or pregnancy alone.Graft caused the higher incidence of PRA than by transfusion and pregnancy.

BACKGROUND:Tissue engineered skin has been used to repair defect skin, but it is not as good as to completely replace permanent skin. OBJECTIVE: To explore the biological characteristics and clinical application of various types of tissue engineered skin. METHODS: Pubmed data (1990-01/2005-12) was retrieved by computer with the key words of "tissue-engineered skin". CNKI database (2002-01/2007-12) was retrieved with the same key words. RESULTS AND CONCLUSION: Totally 226 literatures were primarily selected. After reading titles and Abstracts, studies addressing irrelative objective or repetitive content were excluded, and 11 literatures were included. The aim of skin tissue engineering is to create skin substitute that close to human.skin in histology and functional characteristics. There were many mature tissue engineered skin in clinic, and various artificial skins were developed. Their structure was similar to human, but only had skin barrier function and lack of skin appendages, so they did not have complete skin function, and did not reach skin reestablishment. Ideal skin substitute should process cuticular layer and dermial layer. The dermial layer can reach rapid vascularization and nerve redistribution, can promote physiological wound repair. The cuticular layer can rapidly obtain full barrier and protection function, which can be fully integration with wound surface. A good dermial carrier has good histocompatibility, and a certain physical and chemical properties, such as strength, scratchability, elasticity, gas permeation, water vapor permeability. These can provide a good adherence between dermis and wound surface, offer an ideal fiber stent for cell growth, and finally promote autologous skin growth. Tissue engineered skin has good prospect, but there are many problems that should be solved in biocompatibility and skin function reestablishment.

BACKGROUND: It remains poorly understood regarding the incidence of panel reactive antibody (PRA) production and its influence to renal function and long-term survival in China. OBJECTIVE: To investigate the incidence of PRA after living renal transplant, so as to provide reference for predicting long-term renal survival. METHODS: A total of 54 patients who received living renal transplantation in Beijing Friendship Hospital from March 2005 and October 2007, were selected. PRA, serum creatinine and urea nitrogen level were detected 1-2 years after transplantation. PRA assay was conducted using One Lambda ELISA HLA-Ⅰ +Ⅱ antigen tray. Serum creatinine and urea nitrogen data were offered by clinical laboratory. RESULTS AND CONCLUSION: A total of 12.96% (7/54) patients showed PRA positive after transplantation, with HLA-Ⅱ antibody positive in 6 patients, and HLA-Ⅰ + Ⅱ antibody positive in 1 patient. In these 7 patients, 6 underwent primary transplantation, and PRA negative before transplantation; 1 patient underwent transplantation for the second time, and HLA-Ⅱ antibody positive before transplantation. Creatine and urea nitrogen level were abnormal in 1 patient with HLA-Ⅰ + ⅠⅡ antibody positive and 2 patients with HLA-Ⅱ antibody highly positive. Creatinine and urea nitrogen levels were normal in 4 patients with low level HLA-Ⅱ antibody. Results show that HLA-Ⅰ +Ⅱ antibody positive and high level HLA-Ⅱ antibody affect renal function in living renal recipients, but low level HLA-Ⅱ antibody has no effect on renal function.