Effect of miR-21 down-regulated by H 2O 2 on osteogenic differentiation of MC3T3-E1 cells / 中国修复重建外科杂志

Objective : To explore the effect and mechanism of miR-21 down-regulated which was induced by H 2O 2 on osteogenic differentiation of MC3T3-E1 cells.

Notch1 signaling activation protected myocardium against hypoxia injury via reducing programmed cell death

Programmed cell death plays an important role in cardio protection, and Notch1 was an important factor related to programmed cell death. The role of Notch1 on ischemia myocardium remains unclear.H9C2 myocardial cells were cultured with routine medium, transfected with Notch1 over expression plasmid, Notch1-siRNA-overexpression plasmid and vehicle plasmid for further hypoxic experiment. Condition of hypoxic experiment was 1% oxygen centration and culturing for 12hours, then the cell proliferation activity and apoptosis rate was assessed by MTS kit and flow cytometry, respectively. The expressions of Caspase-3, Caspase-9 and Bcl-2 were determined by RT-qPCR and Western Blot, respectively. Compared with normoxia treatment, hypoxia could decrease H9C2 cell proliferation activity as well as Bcl-2 mRNA expression, and increase cell apoptosis rate as well as Caspase-3 and Caspase-9 mRNA expression. Notch1 activation could increase proliferation activity as well as Bcl-2 mRNA expression, while decrease apoptosis rate as well as Caspase-3 and Caspase-9 mRNA expression. Compared with Notch1 activation H9C2 cells, the opposite effect on programmed cell death was observed in cells with Notch1-siRNA-overexpression plasmid. Targeted activation of Notch1 gene to reduce hypoxia-induced programmed cell death in myocardial cells via up-regulating the expression of Caspase-3 and Caspase-9 and inhibiting the expression of Bcl-2

EFFECT OF ACTIVED RAW264.7 INDUCED BY H2O2 ON MIGRATION, PROLIFERATION AND OSTEOGENESIS GENE EXPRESSION OF MC3T3-E1 / 中国修复重建外科杂志

OBJECTIVE: To explore the effect of H2O2-actived RAW264.7 macrophages on the migration, proliferation, and osteogenesis gene expression of MC3T3-E1 in mice. METHODS: MC3T3-E1 cells and RAW264.7 cells were cultured to the 7th generation. RAW264.7 macrophages were stimulated with 0, 25, 50 and 100 μmol/L H2O2, the cell proliferation rate was detected by MTS at 1, 3, and 6 hours after stimulated, and superoxide dismutase (SOD) content by SOD assay kit at 1 hour after stimulated. The appropriate concentration and action time of H2O2-actived RAW264.7 were obtained. The supernatant of RAW264.7 macrophages stimulated by H2O2 or not was collected at 24 hours. Then, the supernatant was used to culture MC3T3-E1 cells in groups B (not stimulated by H2O2) and C (stimulated by H2O2), and DMEM was used as a control in group A. The migration of MC3T3-E1 cells was detected at 12 and 24 hours by cell scratch test, the proliferation of MC3T3-E1 cells at 24, 48, and 72 hours by MTS assay. MC3T3-E1 cells were cultured with only complete medium in blank control group, with complete medium containing 50 μg/mL vitamin C + 10 nmol/L β sodium glycerophosphate in positive group, normal control group (adding the supernatant not stimulated by H2O2), and experimental group (adding the supernatant stimulated by H2O2). At 3, 7, and 14 days, RT-PCR was used to determine the osteogenesis related mRNA expressions of alkaline phosphatase (ALP), Runx2, osteopontin (OPN), osteocalcin (OC), bone sialoprotein (BSP), and collagen type I (COL-I). RESULTS: The results of MTS and SOD assay showed that the appropriate concentration and action time of H2O2-actived RAW264.7 macrophages were 25 μmol/L and 1 hour, respectively. MTS assay showed that the proliferation rate of MC3T3-E1 cells was significant higher in groups B and C than group A (P<0.05), in group B than group C, and significant difference was shown between groups at 2 and 3 days (P<0.05). The cell scratch test indicated that the migration of MC3T3-E1 cells was significantly faster in groups B and C than group A, and in group C than group B at 12 hours (P<0.05); many migrated cells were observed in all scratch sites of groups B and C at 24 hours. When compared with positive control group, the mRNA expressions of ALP, Runx2, OC and BSP in experimental group were significantly down-regulated at 7 and 14 days (P<0.05). When compared blank control group, the mRNA expressions of OPN and COL-I in experimental group were significantly down-regulated at 7 and 14 days (P<0.05). CONCLUSIONS: The appropriate concentration and action time of H2O2-actived RAW264.7 macrophages are 25 μmol/L and 1 hour. The H2O2-actived RAW264.7 cells can promote MC3T3-E1 cells migration, and suppress MC3T3-E1 cells proliferation and expressions of osteogenesis related genes.

Optimization of triple plasmids transfection into HEK293 cells mediated by polyethylenimine / 生物医学工程学杂志

In the present study, packaging system composed of pAAV-CMV-GFP, pAAV-RC and pHelper were transfected into human embryonic kidney 293 cells (HEK293 cells) mediated by polyethyleneimine (PEI) to explore an optimal transfection condition. Different total plasmid DNA dosages (1, 2, 3, 4, 5, 6 μg) and different PEI/Plasmid ratios (1:1, 3:1, 5:1, 7:1) were tested with detection of green fluorescence protein (GFP) with ImagePro Plus6. 0 Software. Then transfection efficiency of the optimized transfection system was further observed for different time periods(12, 24, 36, 48, 60, 72 h). The results showed that total plasmid dosage of 4 μg/well with PEI/plasmid ratio of 3 : 1-5 : 1 was an efficient transfection condition. Transfection efficiency-time curve was an S-shaped curve. Transfection efficiency reached a plateau at 60 h after transfection. The optimized conditions for PEI-mediated transfection at the optimal time result in enhanced transfection efficiency of triple plasmid into HEK293 cells.

Risk factors of cardiorenal syndrome type 1 in patients with acute myocardial infarction / 中国医师杂志

Objectives To investigate the risk factors of cardiorenal syndrome type 1 (CRS1) in patients with acute myocardial infarction (AMI).Methods The medical date of hospitalized patients with AMI from January,2013 to February,2014 in Hunan Provincial People~ Hospital were reviewed.A total of 265 patients with AMI was divided into CRS1 and non-CRS1 groups.The univariate comparison and multivariate Logistic regression analysis were performed to obtain the CRS1 risk factors.Results In the 265 AMI patients,CRS1 was found in 59 patients (22.3％).Age,history of diabetes,Killip classification,left ventricular ejection fraction (LVFF),baseline serum creatinine,blood urea nitrogen,uric acid,baseline evaluated glomerular filtration rate (eGFR),serum sodium,the left anterior descending artery lesion,emergency percutaneous coronary intervention (PCI),β-blocker,and angiotensin converting enzyme inhibitor/angiotensin receptor antagonist (ACEI/ARB) were statistically different between CRS1 and non-CRS1 groups (all P ＜ 0.05).Multivariate logistic regression showed that age,history of diabetes,Killip classification,reduced LVEF,reduced eGFR,hyponatremia,the left anterior descending artery lesionn,emergency PCI non-undergo,and β-blocker non-use were independent risk factors for CRS1 after AMI.Conclusions CRS1 is a common complication in AMI patients,which is associated with many factors.Our data suggest that patients with AMI should be more comprehensively assessed and monitored,thereby preventing the occurrence of CRS1.

Risk factors for Type 1 cardio-renal syndrome after ST-segment elevation myocardial infarction / 中南大学学报(医学版)

Objective: To explore the risk factors for Type 1 cardio-renal syndrome (CRS1) atfer ST-segment elevation myocardial infarction (STEMI). Methods: A total of 378 patients with STEMI were divided into two groups: a CRS1 group (n=98) and a non-CRS1 group (n=280). Clinical characteristics in the 2 groups were compared, and independent risk factors for CRS1 after STEMI were analyzed, and the effect of emergency Results: In the 378 STEMI patients, CRS1 was found in 98 patients (25.9%). Between the 2 groups, there was significant difference in 12 parameters, including age, history of diabetes, admission mean arterial pressure, admission systolic blood pressure, admission heart rate, Killip classification, left ventricular ejection fraction, baseline serum creatinine, baseline evaluated glomerular ifltration rate (eGFR), emergency PCI, β-blockers and angiotensin converting enzyme inhibitor/angiotensin, receptor antagonist (ACEI/ARB) application (allP0.05). Conclusion: CRS1 is a common complication of STEMI, which is associated with many factors. Immediate revascularization can reduce the incidence of CRS1 in patients with ST-segment elevation myocardial infarction.

Analysis of anemia in chronic heart failure / 中国医师杂志

Objective To investigate the correlation between the incidence and characteristics of anemia in chronic heart failure population through retrospective analysis of patients hospitalized at the Hunan Provincial People's Hospital.Methods A total of 259 patients who were diagnosed as chronic heart failure (CHF) and hospitalized at the Hunan Provincial People's Hospital from October to November in 2012 was collected,and divided into cardiac function Ⅰ ～ Ⅳ grade,then their clinical characteristics was analyzed.Results (1)Compared with CHF patients without anemia,the creatinine value was significantly higher,the percentage of patients with severe heart failure was significantly higher in the CHF patients with anemia (P＜ 0.05).(2) Logistic regression analysis demonstrated that age (95％ CI:1.123 ～ 3.580,P ＜ 0.05),renal insufficiency (95％ CI:1.320 ～ 4.845,P ＜ 0.05),and cardiac function (95 ％ CI:1.368 ～ 3.385,P ＜ 0.05) in patients with heart failure were important risk factors for anemia.Conclusions Anemia was common in CHF patients.The poorer cardiac function was and the lower hemoglobin was,the higher incidence of anemia was.The patients with anemia had the characteristics of worse renal function and poorer nutritional status compared patients without anemia.Age,renal insufficiency,and cardiac function were important risk factors for anemia.

Influence of dehydration degree on biomechanics of allogeneic bone nails / 中国组织工程研究

BACKGROUND:With increasing freeze-drying time,the water content of allogeneic bone reduces along with the bone mechanical strength.The suitable dehydration degree that maintains mechanical strength of allogeneic bone and allows long-term preservation at room temperature remains controversial.OBJECTIVE:To detect the mechanical properties of bovine bone nail following different degrees of dehydration using the three-point bending mechanics tests.DESIGN,TIME AND SETTING:Biomechanical analysis,comparative observation.The experiment was performed at the Mechanical Laboratory of Southern Medical University between May 2007 and May 2008.MATERIALS:Bone nails,50 mm length and 3 mm diameter,made from healthy adult bovine femoral cortical bone were divided into control and freeze-drying groups (8,12,24 hours,respectively) with 20 samples in each group.METHODS:The water content of bone nails with or without freeze-drying was measured by SH10A Moisture Quick Determination Meter.Three-point bending mechanics tests were performed using MTS 858 Mini Bionix.The parameters included load range 0-2000 N,resolution 0.01 N,cross beam replacement resolution 0.001 mm,span 50 mm and loading speed (cross beam replacement speed) 2 mm/min.MAIN OUTCOME MEASURES:Water content,maximal load and elasticity load.RESULTS:The water content of control group was 7%-9%,and following freeze-drying for 8 hours,the water content was 5.5%-6%,which met the standard of freeze-drying bone;Compared with control group,the maximal load and elasticity load reduced respectively 0.004% and 0.000 8% (P＞0.05).Following freeze-drying for 12 and 24 hours,the water content was 3.5%-4% and 1%-1.5%;the maximal load reduced 21% and 37% and the elasticity load reduced 22.5% and 39% compared with control group (P＜0.05).CONCLUSION:Freeze-drying for 8 hours is the best time of dehydration.The mechanical load and elastic modulus reduce with increasing freeze-drying time.

Effect of defatting on the biomechanics of cortical bone / 中国组织工程研究

BACKGROUND: Defatting is to reduce the special cell surface antigens by clearing fat and lipoprotein, so as to decrease immunological rejection, improve the biocompatibility of allograft bone, and increase osteogenic potential. However, the effect of defatting on biomechanical performance of bone remains controversial.OBJECTIVE: To explore the influence of defatting on the biomechanics of bovine cortical bone samples.DESIGN, TIME AND SETTING: Randomized, self-controlled observation was performed in Futian People's Hospital of Guangdong Medical College between 2006 and 2008.MATERIALS: Eight pairs of healthy adult bovine femora were used. Bone blocks, 50 mm long and 10 mm wide, were selected from each pair of femora, and burnished into 24 pairs of 7 mm×7 mm×40 mm rectangular bovine cortical bone samples.METHODS: The 24 pairs of cortical bone samples were randomly divided into two groups (n=12). One of each pair was selected as test group sample, and the other as control group sample. The samples of test group were defatted In 500 mL chloroform and methanol mixture (1:1) for 24 hours, while control samples were immerged in deionized water for 24 hours. Six samples from each group were selected for axial compressive test and three-point bending test.MAIN OUTCOME MEASURES: Load and deflection of every sample.RESULTS: Axial compressive test showed that the maximum load and the maximum strain of defatted samples were significantly decreased compared with control group, but the fragility and elastic modulus were increased (P < 0.05). In three-point bending test, the maximum load and the maximum stress of defatted sampled were significantly decreased, the maximum deflection was decreased, and the elastic modulus was increased (P < 0.05).CONCLUSION: The mechanical strength of cortical bone decreased but the fragility increased after defatting.

Application of dynamic condylar screw in treatment of intertrochanteric fractures of the femur / 中华创伤杂志

Objective To observe the application and efficacy of dynamic condylar screw (DCS) in treating intertrochanteric fractures of the femur and discuss the fixation principle, feasibility, advanta-ges and related issues. Methods A retrospective analysis was done on 23 patients with intertrochanter-ic fractures of the femur treated with DCS from January 2000 to December 2006. Of all, there were 10 elderly patients with different levels of various kinds of internal diseases and 13 young patients injuried by high-energy such as traffic accidents. According to Boyd' s classfication, there was one patient with type Ⅰ fracture, five with type Ⅱ , nine with type Ⅲ and eight with type Ⅳ. After a detailed pre-operative physical examination and targeted treatment, DCS fixation was employed for intertrochanteric fractures of the femur. Results A follow-up for average 18 months showed no death. Early complications occurred in three patients including two with pulmonary infection and one with urinary tract infection, who got cured after proper treatment. There was one patient with long-term complication, post-traumatic arthritis. All 23 patients got bone healing, with excellenee rate of 96% according to Harris criteria. There were no complications like breakage of nails, nonunion, eoxa yarn deformity, shortening or external rotation of the lower limb. Conclusions DCS has advantages of simple operation, reliable fixation and coincidence with biomechanical characteristics and hence is one of ideal methods for treatment of intertrochanteric frac-ture of the femur, especially for subtrochanteric fracture, contrary chanteric fractur, fracture involving large pyriform troehanteric and comminuted fractures of sub-trochanteric lateral os integumentale.

Study on the correlation between estrogen level and tenosynovitis in postmenopausal women / 中国综合临床

Objective To investigate the relationship between estrogen levels and tenosynovitis in postm-enopausal women. Methods 74 cases of postmenopausal women,including 32 cases of tenesynovitis (group A),42 cases healthy postrnenopausal women for the control group (group B) were observed. 42 cases of normal menstruation women were taken as control group (group C). Results The estrogen level was (89.7066±126.7458) pmol/L in group A,(45.6768±30.6342) pmol/L in group B,and (626.7384±361.5348)pmol/L in group C,There is statistical difference between group A and group C (P<0.05). Conclusions Tenosynovitis incidence in postmeno-pausal women has no significant relationship with the level of estrogen change.

Small incision and Absorbable suture for closed Achilles tendon rupture / 中国矫形外科杂志

[Objective]To investigate new methods of the management of closed rupture of Achilles tendon surgery to reduce postoperative skin necrosis.[Method]Small incisions and Absorbable sutures were used to manage 39 cases of closed Achilles tendon rupture,with proximal stump a Bunnell-type suture and remote stump percutaneous repair.[Result]In the 39 cases,three developed slight skin necrosis,of which two healed by changing dressings,the other one healed by debriding and sutureing.Follow-up of 10 months to 36 months was available for 35 cases.According to Arner-Lindholm efficacy evaluation standard,29 cases (82.9%) had excellent result,4(11.4%) had good result,with the good to excellent result of 94.3%.[Conclusion]Small incisions and Absorbable sutures used to manage the closed Achilles tendon rupture,with proximal stump a Bunnell-type suture and remote stump percutaneous repair is an effective and reliable methord for closed Achilles tendon repture,with small invasion,less impact on the skin blood supply,less skin necrosis,less re-rupture reinfection,and faster recovery.