Objective: To study the effect of chronic stress on spatial learning and memory and nitric oxide (NO) in hippocampus of the rats Method: Chronic stress model was established by electric-foot accompanied with noise Morris watermaze was used to observe spatial learning and memory abilities, contents of NO and activities of NOS in hippocampus were measured during the test Result: The spatial learning and memory of chronic stress rats were significantly decreased in Morris watermaze Contents of NO (3 87?0 47 nmol/mgpro) and NOS activity (102 64?13 33 pmol/mgpro/min) in hippocampus of the stress rats were significantly higher than that of normal rats (2 76?0 43 nmol/mgpro, 78 25?10 67 pmol/mgpro/min respectively) Conclusion: Chronic stress impairs spatial learning and memory abilities of rats, which may be related to the increase of NO in their hippocampus

Objective To investigate the efficacy and safety of interventional therapy for central airway stenosing pulmonary disease. Methods In 389 petients diagnosed as central airway stenosis, their primary diseases were handled timely and correctly. On the basis of handling the primary disease, cetral airway stenosis was treated by interventional techniques, including electrosurgical unit (ESU), laser, argon plasma coagulation, freezing, high-pressure balloon expansion, stent implantation, local injection and toilet with lavage. Following the American College of Chest Physicians (ACCP) guidelines, the therapeutic effects were evaluated based on correction of stenosis after interventional treatment and the dyspnea scores. Results Of the 389 patients, 154 were treated with electrosurgical unit under bronchoscopy, 18 with laser, 76 with freezing, 69 with argon plasma coagulation, 35 with high-pressure balloon expansion, 21 with tracheobronchial stent implantation, and 16 with local injection and laving clearance. Evaluation of the therapeutic effects was made one month after the interventional treatment. As a result of the interventional treatment, a complete relieve was observed in 152 cases (39.1%), partial relieve in 138 cases (35.5%), mild response in 67 cases (17.2%), no response in 32 cases (8.2%), and with 17 deaths (4.4%). The total effective rate was 91.8%. The dyspnea scores were 1.8?0.5 before the treatment, and 0.7?0.4 after the treatment, with statistically significant difference (P

Objective To observe the effects of cyclic tensile strain (CTS) on in vitro expression of glycosaminoglycans (GAG) in rabbit chondrocytes of different ages.Methods Nine male New Zealand rabbits were grouped into juvenile (2 months), adult (8 months), and senior (31 months) groups. The bilateral knee joints were harvested using sterile technique from each rabbits. In each age group, rabbit articular chondrocytes were cultivated in vitro after randomization into a control group and a CTS group, with 6 specimens in each. In the next 3 days, CTS was applied (sin10％, 0. 5 Hz, 6 h/d) in the CTS group for 6 hours per day while no CTS was applied in the control group. After the first CTS treatment, the supernatant of cell culture was collected every 12 hours from each specimen in both groups to assess the GAG levels by Alcian blue assay.Results Expressions of GAG showed significant increases in both control and CTS groups in each age group ( P ＜ 0. 05) . Different age groups showed significant differences in the GAG secretion over different time points. Compared with the younger cells, the older ones showed the most significant difference in growth between the control and CTS groups at 12 hours, though the older cells produced less GAG than the younger ones in both groups at the end of the experiment (72 hours).Conclusions CTS can stimulate rabbit chondrocytes of different ages to secrete more GAG, and younger cells tend to produce more GAG than the older ones.

Objective To explore the histological properties of isolated chondrons and chondrocytes from rabbit knee cartilage,and to determine if these properties vary with age.Methods Three groups of rabbit knees were evaluated according to different age:(1) young (2 months,n=10);(2) adult (8 months,n=10);and (3) old (31 months,n=10).The cartilage structure,proteoglycan,collagen-2,and collagen-6 content were determined by light microscopic using hematoxylin-eosin (HE),Toluidine Blue,and col-2,6 staining.The chondrons were enzymatically isolated using 0.3 g/L dispase and 0.2 g/L collagenase-2 by shaking for 3 hours.The morphology and composition of isolated chondrons were observed by HE and collagen-6 immunostaining staining after overnight coverslip monolayer culture under a microscopy.Results The chondrocytes became sparser and the total content of proteoglycans and collagen-2 were decreased in the articular cartilage with age.Compared to the chondrocytes,the surrounding rim or capsule was more obvious in the isolated chondrons,and they exhibited obvious differences in shape.The cells within one cluster from different age groups were similar to the morphology observed in cartilage in situ.The adult and old chondrons generally possessed a thicker pericellular matrix with more enclosed cells,and the chondrons contained more cells can reach 47％.Conclusion These findings further suggest that the properties of the chondrons and pericellular matrix have an important influence on the biomechanical microenvironment of the knee joint cartilage degeneration that occurs with age.

BACKGROUND:Such methods as transplanting autologous periosteum or autologous bone marrow mesenchymal stem cells (BMSCs) can promote the repair of articular cartilage defects for sure. But they all have their own limits in chondrogenic abilities,which results in an unsatisfactory curative effect.OBJECTIVE:To study the effect of transplanting BMSCs (which were induced into chondrocytes) combined with autogenous periosteum on repairing articular cartilage defects in rabbits.MATERIALS:A total of 18 New Zealand rabbits,aged 6-8 months,were divided with random digits table method into 3 groups,namely,periosteum+BMSCs group,periosteum group and blank control group,with 6 ones (12 knee joint samples) in each group. METHODS:In periosteum+BMSCs group,BMSCs were harvested and adherently cultured with trypsin digestion method. Then they were induced by transforming growth factor 81 into chondrocytes. At the same time,immunofluorescence labeling was performed to BMSCs membranes with PKH-26. Full-thickness articular cartilage defects (diameter:3mm,depth:3mm) were made to bilateral condylus medialis femoris of all rabbits. In periosteum+BMSCs group and periosteum group,defects were covered by homolateral autogenous proximal tibia periosteums,with germinal layer facing to cavitas medullaris. After that,the periosteum+BMSCs group received 3 sutures,followed by injection of 20 μL BMSCs suspension (1×109/L) into the defects,after which the last suture was taken. The periosteum group underwent coverage with periosteum on defects only. The blank control group underwent perforate only.MAIN OUTCOME MEASURES:General observation,histological observation,Wakitani's score,immunohistochemical and in situ hybridization detection of collagen type Ⅱ were performed to defects at 6 and 12 weeks following operation.RESULTS:No sutured periosteums were found desquamate. In periosteum+BMSCs group,defects were filled with hyaline cartilage-like repairing tissues at week 6 following operation;Week 12 following operation saw remodeled tissues whose cells were mainly the implanted cells labeled with PKH-26. In periosteum group,repairing tissues in defect areas were ivory white,smooth with light introcession and distinctively different from the surrounding normal cartilage tissue. In the blank control group,clearer introcession or irregular appearance,even broken surrounding cartilage tissues could be seen in the defect area. Both Wakitani's score and histological score were highest in periosteum+BMSCs group at week 6 and 12 following operation (P＜0.05),with higher ones in periosteum group than in the control group (P＜0.05). What'more,matrix around cells in the repairing tissues showed positive results to both immunohistochemical and in situ hybridization staining of collagen typeⅡ,which proved that cells in repairing tissues were the implanted ones.CONCLUSION:Transplanted BMSCs (which were induced into chondrocytes) combined with autogenous periosteum can form hyaline cartilage-like repairing tissues through which articular cartilage defects are repaired.

Objective To characterize the biomechanical behavior and properties of the chondrons enzymatically isolated from rabbit knee articular cartilage in virto. Methods Eight months old New Zealand white rabbits were randomly divided into chondroctye and chondron groups (4 rabbits in each group). In chondrocyte groups, the full articular cartilages from both knees were enzymatically isolated to chondrocytes by 0.4% pronase and 0.025% collagenase type-Ⅱ in turn. In chondron groups, chondrons were obtained from articular cartilage using the mixture of 0.3% dispase (a neutral protease) and 0.2% collagenase type-Ⅱin at 37C for 3 h. The micropipette aspiration was used to quantify changes in biomechanical properties of chondrons and chondrocytes and the viscoelastic parameters, including K1, K2, E∞ (equilibrium modulus), E0(instantaneous modulus), and μ (apparent viscosity), were calculated coupled with standard linear half-space viscoelastic solid model. Results In response to a constant negative pressure of 0.2-0.4 kPa, the chondrocytes exhibited standard linear viscoelastic solid properties. Namely, the cells showed an initial elastic response followed by a viscoelastic creep response. then cells continued to enter into the micropipette with a monotonically decreasing rate of deformation, until reaching equilibrium within about (110±18) s. Comparing with chondrocytes, the chondrons exhibited significant viscoelasticity under a greater negative pressure of 1.0-1.2 kPa. But the instantaneous length deformed into the micropipette significantly reduced, and the equilibrium time reduced to (36.5±4.5) s. The equilibrium modulus (E∞), the instantaneous modulus (E0) and the apparent viscosity (μ) of chondrons were significantly higher than the those of chondrocytes. Conclusion Comparing with chondrocytes, the chondrons exhibited significant viscoelastic properties, and viscoelastic properties of chondrons have increased in vitro.

Objective To analyze the clinical feasibility and effectiveness of the "G"-shaped surgical approach in robotic pancreatoduodenectomy. Methods The clinical data of 17 patients who were undergoing robotic pancreatoduodenectomy at the First Hospital of Shanxi Medical University from June 2017 to March 2018 was analyzed. Results All the 17 robotic pancreatoduodenectomy operations via the "G"-shaped surgical approach were successful. The operationtime was (499 ±146) min (350-825 min), and the blood loss was (119±38) ml (20-500 ml). All surgical margins were negative. All patients recovered well after surgeries, and the postoperative hospital stay was (21 ±6) (14-36 days). However, one patient experienced secondary surgery due to bilioenteric anastomosis fistula, fortunately the surgical process went successfully. This patient had pancreatic leakage (class B) after surgery and was discharged with tubes after a conservative treatment, another patient had gastroplegia and recovered completely after conservative treatment. Conclusion It is a safe and feasible procedure to use the robotic pancreatoduodenectomy with the"G"-shaped surgical approach.

Objective:To investigate the differences in gene expression levels in knee chondrocytes and chondrons in vitro.Methods:The chondrocytes and chondrons were isolated from full thickness of the 8-months ( n=5) rabbit knees cartilage. Chondrons from right knee were enzymatically isolated using 0.3% dispase and 0.2% collagenase-2 with shaking for 3 hours. Chondrocytes were isolated by 0.4% Pronase and 0.025% collagenase-2 from left knee. The mRNA levels in chondrocytes and chondrons were analyzed by quantitative real-time PCR, including matrix proteins [aggrecan(Agg), collagen(Col-2), Col-6A6, Col-10, Col-11], MMPs and inhibitors (MMP-1, MMP-3, MMP-9, MMP-13, TIMP-1, TIMP-2, TIMP-3), cytoskeletal proteins (Sox-9, vinculin, tubulin, actin), cytokines (IL-β, TNF-α). Analysis was performed using SPSS 16.0 statistical software, and the two-group comparisons were considered as significant by t-test at P<0.05. Results:Compared to the chondrocytes, the Agg [(5.78±0.90) vs (1.89±0.27), t=9.26, P<0.001], Col-2 [(6.29±0.76) vs (3.06±0.60), t=7.46, P<0.001], Col-6A6 [(0.89±0.18) vs (0.22±0.06), t=7.90, P<0.001], Col-10 [(3.83±0.76) vs (1.00±0.26), t=7.88, P<0.001] and TIMP-1 [(1.98±0.85) vs (1.03±0.34), t=2.32, P=0.049], TIMP-2[(3.46±1.50) vs (1.52±1.06), t=2.36, P=0.046], TIMP-3 [(3.96±0.50) vs (1.36±0.18), t=10.94, P<0.001], Sox-9 [(7.09±2.93) vs (3.24±0.77), t=2.84, P=0.022], vinculin [(3.42±1.69) vs (1.46±0.68), t=2.41, P=0.043], tubulin[(9.34±0.71) vs (2.35±0.80), t=14.61, P<0.001] showed higher expression in the chondrons. Compared to the chondrocytes, the MMP-1 [(1.02±0.30) vs (2.67±0.45), t=6.91, P<0.001], MMP-3 [(1.21±0.32) vs (2.52±0.79), t=3.44, P=0.009], MMP-13 [(1.23±0.34) vs (3.42±0.86), t=5.30, P=0.007], IL-1β [(1.02±0.14) vs (2.70±0.49), t=7.37, P<0.001], TNF-α [(0.99±0.08) vs (3.15±0.54), t=8.85, P<0.001] showed lower expression in the chondrons. There were no difference between chondrons and chondrocytes for Col-11, MMP-9, actin ( P>0.05). Conclusion:The gene expression of extracellular matrix components are higher and the gene expression levels of inflammatory factors and MMPs are decreased in chondrons compared with the chondrocytes, suggesting the chondrons have more multiplication potential as seeding cells for tissue-engineered cartilage.

Objective:To investigate the short-term effects of articular injection of hyaluronic acid combined with glucocorticoid in patients with knee osteoarthritis.Methods:From October 2017 to June 2018, a total of 188 patients diagnosed with knee osteoarthritis received parallel articular injection. There were 60 cases with mild knee osteoarthritis, 72 with moderate and 56 with severe according to the WOMAC knee functional score. There patients were divided into group rank Ⅰ48 cases, Ⅱ 49 cases, Ⅲ 45 cases, Ⅳ 46 cases according to the knee joint X-ray Kellgren-Lawrence classification. The unified treatment regimen was 2.5 ml Sodium Hyaluronate (SHA) injection for the first time, SHA 2.5 ml and compound betamethasone injection (CBI) 1 ml for the second week, and 2.5 ml of SHA for the third week. WOMAC score and Lequesne index were used to evaluate joint function before the first injection and after SHA and SHA+CBI injection. The improvement rate of Lequesne index ≥30% or improvement rate of WOMAC score ≥25% was regarded as effective treatment.Results:Lequesne index and WOMAC score decreased gradually in the mild, moderate and severe groups after 3 weeks of injection. Among these patients, the improvement rates of Lequesne index after SHA injection and SHA+CBI injection were 36.44%±8.46% and 49.26%±13.75% in the mild group, 23.09%±12.61% and 30.66%±14.95% in the moderate group, and 10.50%±8.78% and 11.07%±6.52% in the severe group. The improvement rate of WOMAC score in the mild group after SHA injection and after SHA+CBI injection was greater than 25%. After SHA injection, the improvement rate of WOMAC score was 13.06%±10.21% in the moderate group, and 27.49%±13.61% after SHA+CBI injection. Those in severe group were all less than 25%. Kendall's staub correlation analysis results showed that there was a strong positive correlation between WOMAC function score and X-ray Kellgren-Lawrence classification ( r=0.744, P<0.001). The Lequesne index and WOMAC scores of the Kellgren-Lawrence X-ray classification decreased gradually after 3 weeks of injection. The improvement rate of Lequesne index period in group rank Ⅰ after SHA and SHA+CBI injection was 36.64%±10.05% and 52.00%±8.19%, respectively. That for group rank Ⅱ was 32.05%±8.09% and 41.95%±10.53%, group rank Ⅲ 16.93%±10.34% and 27.77%±10.25%, group rank Ⅳ 7.52%±5.53% and 7.60%±6.66%. The improvement rate of WOMAC score period in group rank Ⅰ after SHA and SHA+CBI injection was 29.48%±11.77% and 42.59%±13.55%, respectively. That for group rank Ⅱ was 26.72%±10.21% and 30.49%±16.90%, group rank Ⅲ 13.78%±5.96% and 23.05%±9.52%, group rank Ⅳ 4.77%±3.80% and 4.27%±4.23%. Conclusion:For mild or X-ray classification Ⅰ, Ⅱ knee osteoarthritis patients, articular injection SHA or SHA+CBI are effective. Further, SHA+CBI is better than single injection of SHA. SHA+CBI injection was effective for moderate knee osteoarthritis patients. For severe or X-ray classification Ⅲ, Ⅳ patients, SHA or SHA+CBI injection at interval are invalid.

Objective:To investigate the cognition and learning habits of different types of postgraduates and evaluate learning effect and its potential risk factors on clinical epidemiology in a medical college, so as to provide relevant data for improving the teaching method and learning effect of clinical research methods for postgraduates.Methods:A cross-sectional study design was conducted to enroll all the postgraduates of Grade 2020 in a military medical school. A self-filled questionnaire was adopted to collect data. The discrepancy of cognition and learning habits between different types of postgraduates was evaluated by univariate analysis. Discussion was conducted to clarify the potential risk factors of learning effect. t tests or Mann-Whitney U tests were conducted to test the differences between groups for continuous variables. Chi-squared tests or McNemar tests were applied to evaluate the difference between groups for categorical variables. Results:A total of 652 postgraduate students were enrolled for analysis, including 409 master students (62.7) and 243 doctoral students (37.3). The proportion of doctoral students who have heard of clinical epidemiology ( χ2=19.99, P<0.001), who have learned clinical epidemiology ( χ2=9.20, P=0.002), who are interested in ( χ2=11.41, P=0.001) and think the course is important ( χ2=10.71, P=0.001), who previewed before class( χ2=11.21, P=0.001), reviewed after class ( χ2=3.29, P=0.001) and actively discuss in class ( χ2=11.64, P=0.001) is significantly higher than that of master students, the difference was statistically significance. The average score of all the postgraduates was (5.50±1.62) points before teaching and (7.47±1.90) points after teaching, the difference was statistically significant ( t=-23.49, P<0.001). After teaching, the grades of full-time students improved more than that of part-time graduate students, there was statistical significance in the master group ( t=4.41, P<0.001), while not in the doctor group ( t=0.94, P=0.351). Conclusions:The mastery of key points on clinical epidemiology have significantly improved after teaching among the postgraduates of different types. Different teaching methods and processes should be adopted to the variety of postgraduates according to their knowledge foundations and shortcomings. Besides, standardizing their learning habits are of certain significance to improve the learning effect.