AIM: To investigate whether viable apoptotic cells and phagocytosis of them affect the activation of T lymphocytes. METHODS: Ultraviolet irradiation was used to induce apoptotic cells in vitro and the model of phagocytosis of these cells was established. Cytokine TGF ?1 was detected by ELISA. The rate of apoptotic cells and phagocytosis of them were assessed by flow cytometry. Furthermore, flow cytometry was also employed to examine the expression of activation signs, such as CD69, CD25, CD71, of T lymphocytes under the intervention of apoptotic cells and macrophage which ingested apoptotic cells, to reflect whether the apoptotic cells and the phagocytosis of these cells could influence the activation of lymphocytes stimulated by Con A. RESULTS: Ingestion of apoptotic cells increased TGF ?1 secretion. Only the macrophages that had ingested apoptotic cells could suppress the activation of lymphocytes. The expression of the markers of lymphocytes activation such as CD69, CD25, CD71 had been restrained. These inhibition effects were abolished by monoclonal anti-TGF ?1 antibody. CONCLUSION: The macrophages that have ingested apoptotic cells inhibit expression of CD69, CD25 and CD71 of T lymphocytes stimulated by ConA. This effect is dependent on the increase in TGF ?1 secretion in local site. [

Objective To investigate the correlation of medial meniscus extrusion with meniscus injury location, type and genu varum. Methods From March 2014 to March 2015, a total of 97 patients with injury of medial meniscus undergoing ar?throscopy and surgery were selected as subjects, including 40 males and 57 females, aged 32-66 years, with a mean age of 51.2± 10.71 years. Based on the MRI of knee, there were 38 cases with medial meniscus extrusion≥3 mm (extrusion group) and 59 cases without medial meniscus extrusion (non?extrusion group). Genu varus was measured on X?ray (Femur?Tibia?Angle<182°). The me?dial meniscus tear type was observed under arthroscopy (longitudinal tear, horizontal tear, oblique tear, radial tear, complex tear), as well as the meniscus tear location (anterior tear, body tear, posterior tear, root tear). The age, gender, BMI and involved side were compared between two groups. Multifactor unconditioned Logistic regression analysis was employed to analyze risk factors of medial meniscus extrusion. Results Two groups of patient showed no statistically significant difference in age (t=-1.511, P=0.135), gender (χ2=0.208, P=0.648), BMI (t=0.249, P=0.650) and side (χ2=0.052, P=0.820). The incidence of meniscus extru?sion in patients with genu varum was 89% (25/28), and the incidence of meniscus extrusion in patients with meniscus root tear was 78% (18/23). Significant difference could be spotted in the analysis of meniscal root tear (χ2=19.329, P=0.000), complex tear (χ2=5.111, P=0.024), genu varus (χ2=41.481, P=0.000) between patients with medial meniscus extrusion or without medial meniscus extrusion. Meanwhile, meniscus anterior tear (χ2=0.044, P=1.000), body tear (χ2=0.261, P=0.661), posterior tear (χ2=3.722, P=0.086), longitudinal tear (χ2=0.054, P=0.816), horizontal tear (χ2=0.317, P=0.790), oblique tear (χ2=0.198, P=0.819), radial tear (χ2=1.188, P=0.385) no statistical significance. By multifactor analysis, OR values of genu varus and root tear were 101.976 (95%CI:15.973, 651.041, P=0.000) and 35.517 (95%CI:6.804, 185.399, P=0.000), respectively. Conclusion Menis?cal root tear and genu varum were risk factors of medial meniscus extrusion.

With the continuous progress of diagnosis and treatment technology on knee osteoarthrosis,the concept of"stepwise treatment" and "keeping meniscus as much as possible" has been deeply rooted in people's minds.As an important anatomical structure for maintaining the annular tension of the medial meniscus of the knee,more and more attention has been paid to the posterior root.After the root tear of the medial meniscus,the annular tension loss,leading to the meniscus bearing load function partial or complete loss,and secondary knee medial space narrow,cartilage degeneration and genu varus deformity.In the treatment of root tear of the medial meniscus different scholars hold different views.The treatment of the medial meniscus posterior root tear of the knee is mainly conservative treatment and operative treatment,and the conservative treatment mainly includes non-steroidal drugs,functional exercise,physical therapy,and so on.The surgical treatment mainly included the medial meniscus partial resection of the medial meniscus under the arthroscope,the medial meniscus posterior root repair under the arthroscopy,and osteotomy with medial meniscus posterior root repair under the arthroscopy.Despite the short-term curative effect of conservative therapy and resection is satisfied,long-term follow-up has no obvious improvement with knee pain,function and activity levels,and causes secondary biomechanical change of knee.For patients of age ＜65,genu varus ＜5°,Outerbridge cartilage classification ＜ grade Ⅲ and grade of Kellgren-Lawrence ＜ level Ⅲ,the curative effect of medial meniscus posterior root repair under the arthroscopy is satisfied,with good healing rate,and can delay the process of osteoarthritis in certain degree.For patients with joint deformities (medial proximal tibial angle ＜ 85°/lateral distal femur angle ＞90°) genu varus ＞5°,osteotomy can effectively improve the clinical curative effect.However,whether to repair the medial meniscus posterior root together is still controversial.

Objective Taking pig kidney as an example, through a series of comparative and analogical experiments, the influencing factors of compressive stress at relaxation stage of biological tissues were analyzed, and a more accurate and widely applicable biomechanical model at relaxation stage was established. Methods The compressive stress relaxation experiments of pig kidney under different conditions were carried out by using the self-built mechanical experiment platform. The collected data were analyzed and mapped, and various factors affecting the relaxation force changes were summarized. Based on the conclusion, the neural network learning algorithm was used to model the force change process at relaxation stage of pig kidney. Results The pre-extrusion pressure and relaxation time were the main influencing factors for compressive stress changes of biological tissues at relaxation stage. The average error of test sample validation experiment was 6.4 mN, and the average prediction error of generalization sample validation experiment was 34.9 mN, so the modeling effect was good. Conclusions Neural network modeling algorithm has the advantages of strong generalization ability and good fault tolerance, which contributes to providing more realistic force tactile feedback prediction for virtual surgery system. It is also a new idea for mechanical modeling of nonlinear biological tissues.

Objective To explore the correlation between old anterior cruciate ligament (ACL) injury with medial menis-cal tears and posterior slope of tibial plateau. Methods Between July 2014 and February 2016, retrospective analyzed 177 pa-tients diagnosed with old ACL injury (injured to surgery time>3 months) who has been underwent arthroscopic treatment. 93 pa-tients included in this study contained 65 male and 28 female,the average age was (32.36±4.50) years old (ranged from 21 to 44 years). All patients were diagnosed with ACL rupture and no associated medial meniscus tear by MR examination at the time of in-jury and before operation. Posterior slope angle of tibial plateau was measured via MR. The patients were divided into two groups according to the presence of medial meniscus tear by preoperative MR examination. Statistical analysis was employed to analyze the difference between the two groups of patients's age, body mass index (BMI), posterior slope angle of tibial plateau, gender and side. The patients were divided into group of posterior slope of tibial plateau ≥10° and posterior slope of tibial plateau<10° re-spectively. Statistical analysis was employed to analyze the incidence of concomitant medial meniscus tear between the two groups. Result All 93 patients in this study were followed up for the average of 8.63 ± 3.74 months. 51(51/93, 55%) patients were com-firmed of concomitant medial meniscus tear and 42 (42/93, 45%) patients without medial meniscus tear through MR and arthro-scope. There was no statistical difference between two groups in age (t=0.843, P=0.843), gender (χ2=1.027, P=0.338), BMI (t=0.568, P=0.571) and side (χ2=0.110, P=0.438). There was a certain correlation between the medial meniscal tears and posterior slope angle of tibial plateau in this group and the values were considered statistically significant ( r=0.602, P=0.000). Posterior slope angle of tibial plateau of medial meniscus tear group (10.51°±2.83°) was significantly higher than that in non medial menis-cus tear group (7.39°±4.62°). Values were considered statistically significant .71.15%(37/51) of the patients showed medial meniscus tear in the group of posterior slope of tibial plateau ≥10° , however, only 34.14%(14/42) patients indicated medial meniscus tear in group of posterior slope of tibial plateau<10°, and the difference was statistically significant(χ2=12.677,P=0.000). Con-clusion There is a certain correlation between old ACL injury with medial meniscal tears and posterior slope angle of tibial pla-teau. With the continuous increase of ACL injury time, high posterior slope angle of tibial plateau (≥10°) is more likely to increase the incidence of medial meniscus tear.

BACKGROUND: Preliminary study has prepared the three-dimensional silk fibroin/chitosan/nano-hydroxyapatite scaffold successfully.OBJECTIVE: To explore the mechanical properties, physical characteristics, chemical composition and antibiotic sustained-release ability of three-dimensional silk fibroin/chitosan/nano-hydroxyapatite scaffold loaded with levofloxacin. METHODS: Levofloxacin/chitosan (3:1) microspheres were constructed by emulsion settlement filter method. 5, 7.5 and 10 g of microspheres were added into 2％ of silk fibroin/chitosan/nano-hydroxyapatite mixed solution through freeze drying and chemical cross-linking to obtain the scaffolds loaded with antibiotics. The scaffolds loaded with antibiotics underwent scanning electron microscope observation, and chemical composition analysis. The sustained release, mechanical properties, porosity, water absorption expansion rate and hot water soluble loss rate were detected. RESULTS AND CONCLUSION: (1) Scanning electron microscope observed that there were drug microspheres at the inner wall of the scaffold, and the voidage was decreased with mass of microspheres increasing. (2) Energy spectrum analysis showed that the three kinds of scaffolds were rich in calcium and phosphonium ions. (3) The three kinds of scaffolds showed the same releasing trend, which presented with sudden-release effect at the former 3 days (release> 50％) , and then tended to be stable. The release rate was the slowest in the scaffold loaded with 10 g of microscopes, and the rapidest in the scaffold loaded with 5 g of microscopes. (4) With the mass of microspheres increasing, there was an increase in the compressive and tension abilities and hot water soluble loss rate, and a decrease in the porosity, mean pore size and water absorption expansion rate. (5) These results indicate that the three-dimensional tissue-engineered scaffold loaded with levofloxacin is constructed successfully by freeze drying and chemical cross-linking method, which holds good sustained-release effect and compressive ability, water absorption expansion rate and hot water soluble loss rate.

Objective:To investigate the efficacy of tibiofibular-based reconstruction technique with single femoral tunnel for Fanelli type C posterolateral complex (PLC) injury.Methods:A retrospective case series study was conducted to analyze the clinical data of 16 patients with Fanelli type C PLC injury admitted to Tianjin Hospital from July 2016 to July 2019, including 10 males and 6 females, aged 20-61 years [(36.5±13.9)years]. PLC reconstruction was performed by tibiofibular-based technique with single femoral tunnel using gracilis tendon and semi-tendinosus autografts. If the posterior and anterior cruciate ligaments (PCL/ACL) rupture were combined, arthroscopic single bundle reconstruction was performed simultaneously. If the posteromedial corner (PMC) injury was combined, PMC repair or reconstruction surgery was performed simultaneously. Operation time and intraoperative blood loss were recorded. When the bone needle and tunnel for PLC were drilled during the operation, the interference of the femoral tunnel through the cruciate ligament was observed under the arthroscope. Before and at 6 and 12 months after operation, the varus stability of the knee joint was evaluated with the difference of lateral joint space width of both knees and the International Knee Documentation Committee (IKDC) objective classification of varus stability of the knee joint; the external rotation stability was evaluated with the difference of external rotation angle of both knees and the IKDC objective classification of external rotation stability of the knee joint. Before, at 6 and 12 months after operation and at the last follow-up, IKDC 2000 subjective score and Lysholm score were compared. The occurrence of complications was observed.Results:All the patients were followed up for 12-36 months [24(15, 33)months]. The operation time was 100-220 minutes [175.0(111.3, 200.0)minutes], with intraoperative blood loss of 30-150 ml [(84.3±36.5)ml]. Intraoperative arthroscopy showed no interference of perforation between PLC and cruciate ligament femoral tunnel. The differences of lateral joint space width of both knees at 6 and 12 months after operation were 0.5(0.2, 1.4)mm and 0.6(0.2, 1.5)mm respectively, which were both significantly improved compared with 12.1(10.8, 12.6)mm before operation ( P<0.05), while there was no significant difference at 6 and 12 months after operation ( P>0.05). The IKDC objective classification of varus stability of the knee joint was grade A in 13 patients, grade B in two and grade C in one at 6 or 12 months after operation, and showed statistical difference from grade D in all the patients before operation ( P<0.01). At 6 and 12 months after operation, the difference of external rotation angle of both knees was -2.0(-3.2, 1.3)° and -1.4(-3.0, 1.7)° respectively, which were significantly improved compared with 16.8(13.9, 18.4)° before operation ( P<0.05), while there was no significant difference at 6 and 12 months after operation ( P>0.05). IKDC objective classification of external rotation stability of the knee joint was grade A in 14 patients, grade B in one and grade C in one at 6 or 12 months after operation, and showed statistical difference from grade C in 14 patients and grade D in 2 before operation ( P<0.01). At 6 and 12 months after operation and at the last follow-up, the IKDC 2000 subjective scores [(76.3±4.7)points, (80.3±4.4)points, (79.9±3.8)points respectively] and the Lysholm scores [(76.1±3.9)points, (81.1±4.3)points, (82.8±3.2)points respectively] were significantly improved compared with those before operation [(48.6±3.7)points and (52.6±2.4)points] ( P<0.05). The IKDC 2000 subjective scores and Lysholm scores were significantly improved at 12 months after operation and at the last follow-up than those at 6 months after operation ( P<0.05). There were no significant differences in the IKDC 2000 subjective scores and Lysholm scores at 12 months after operation and at the last follow-up ( P>0.05). There were no complications such as wound infection, vascular and nerve injury, joint stiffness or ectopic ossification. Conclusion:For Fanelli type C PLC injury, tibiofibular-based reconstruction technique with single femoral tunnel reduces the interference between the lateral femoral tunnels, significantly improves the varus and external rotation stability and the function of the knee joint, and has few complications and satisfactory short-term clinical efficacy.

OBJECTIVETo analyze the distribution characteristics of hirsutism and the law of meridian differentiation in polycystic ovarian syndrome (PCOS).

METHODSFor the patients of PCOS, the modified Ferriman-Gallwey score (mF-G score) was adopted to evaluate the hirsutism distribution. The clementine data mining software was used to analyze the distribution region of hirsutism and the correlation with meridian.

RESULTSA total of 141 patients of PCOS participated in the study. The most common regions of hirsutism were in the upper lip (50.35%) and the lower abdomen (34.04%). The higher frequencies of hirsutism at two regions were at the upper lip and lower abdomen (24.82%), the upper lip and chest (12.06%) and the upper lip and thigh (11.35%). In the analysis on the correlation of the upper lip, lower abdomen and chest with other regions, hirsutism was more common in the nearby regions. In reference to the running course of meridian, the frequencies of hirsutism from high to low were the conception vessel (63.12%), the thoroughfare vessel (61.70%), the liver meridian of foot-(58.16%) and the stomach meridian of foot-(57.45%). According to:-, the high incidence of hirsutism (59.57%） resulted from the change ofand blood inmeridian. .

CONCLUSIONBlood plays the important role in the growth of body hair. Regarding theattribution, the incidence of hirsutism at theregions is higher than theregions. The occurrence of hirsutism is closely related toand blood changes in meridians. The conception vessel, the thoroughfare vessel, the liver meridian of foot-andmeridian act highly on the disease.

Objective: To evaluate the effect of the ischemic post-conditioning (IPC) on the prevention of the cardio-renal damage in patients with acute ST-segment elevation myocardial infarction (STEMI) after primary percutaneous coronary intervention (PPCI). Methods: A total of 251 consecutive STEMI patients underwent PPCI in the heart center of Tianjin Third Central Hospital from January 2012 to June 2014 were enrolled in this prospective, randomized, control, single-blinded, clinical registry study. Patients were randomly divided into IPC group (123 cases) and control group (128 cases) with random number table. Patients in IPC group underwent three times of inflation/deflation with low inflation pressure using a balloon catheter within one minute after culprit vessel blood recovery, and then treated by PPCI. Patients in control group received PPCI procedure directly. The basic clinical characteristics, incidence of reperfusion arrhythmia during the procedure, the rate of electrocardiogram ST-segment decline, peak value of myocardial necrosis markers, incidence of contrast induced acute kidney injury(CI-AKI), and one-year major adverse cardiovascular events(MACE) which including myocardial infarction again, malignant arrhythmia, rehospitalization for heart failure, repeat revascularization, stroke, and death after the procedure were analyzed between the two groups. Results: The age of IPC group and control group were comparable((61.2±12.6) vs. (64.2±12.1) years old, P=0.768). The incidence of reperfusion arrhythmia during the procedure was significantly lower in the IPC group than in the control group(42.28% (52/123) vs. 57.03% (73/128), P=0.023). The rate of electrocardiogram ST-segment decline immediately after the procedure was significantly higher in the IPC group than in the control group (77.24% (95/123) vs. 64.84% (83/128), P=0.037). The peak value of myocardial necrosis markers after the procedure were significantly lower in the IPC group than in the control group(creatine kinase: 1 257 (682, 2 202) U/L vs. 1 737(794, 2 816)U/L, P=0.029; creatine kinase-MB: 123(75, 218)U/L vs.165(95, 288)U/L, P=0.010). The rate of CI-AKI after the procedure was significantly lower in the IPC group than in the control group(5.69%(7/123) vs. 14.06%(18/128), P=0.034). The rate of the one-year MACE was significantly lower in the IPC group than in the control group(7.32%(9/123) vs. 15.63% (20/128), P=0.040). Conclusion The IPC strategy performed eight before PPCI can reduce myocardial ischemia- reperfusion injury, decline the rates of CI-AKI and one-year MACE significantly in STEMI patients, thus has a significant protective effect on heart and kidney in STEMI patients. Clinical Trial Registration Chinese Clinical Trials Registry, ChiCTR-ICR-15006590.

Objective:To establish and evaluate a predictive model for recurrence risk of Graves′ disease after antithyroid drugs(ATD) withdrawal.Methods:Among 308 patients with newly onset Graves′ disease taking ATD from 2012 to 2019, 170 patients who completed follow-up were enrolled and divided into relapse and remission groups according to whether hyperthyroidism reoccurred within 2 years after ATD withdrawal to establish the discovery cohort. An internal validation cohort was constructed by repeating the sampling with bootstrap. Cox regression analysis was used to screen risk factors and establish a predictive model, named Graves′ Recurrence Evaluation System(GRES). The differentiation and accuracy of GRES model were evaluated and compared with the GREAT score.Results:Of 170 patients, 90 Graves′ disease cases relapsed within 2 years after ATD withdrawal. According to Cox regression analysis, family history of Graves′ disease, younger age(<30 years), grade Ⅱ-Ⅲ goiter, high level of TRAb(≥13 IU/L), large thyroid volume(≥26.4 cm 3) and low 25(OH) D(<14.7 ng/mL) were included in the predictive model: PI=0.672×family history+ 0.405×age+ 0.491×severity of goiter+ 0.808×TRAb+ 1.423×thyroid volume+ 0.579×25(OH) D. PI≥1.449 was associated with a higher risk of recurrence after drug withdrawal. The GRES model has good prediction in assessing Graves′ disease relapse within 2 years after ATD withdrawal and better than GREAT score. Conclusion:GRES model can be used to evaluate the recurrence risk within 2 years for patients with newly onset Graves′ disease after ATD withdrawal, and facilitate clinicians to reasonably select treatment modalities in order to improve the remission rate.