BACKGROUND: Bone marrow mesenchymal stem cells (BMSCs) are conveniently cultured and separated in vitro because theirimmunogenicity is low. Therefore, BMSCs are suitable for cell transplantation. Research has shown that BMSCs are potential to repair neurological defect. OBJECTIVE: To determine whether in vitro cultured BMSCs can be transplanted to repair peripheral nerve injury or not, and to investigate its mechanisms. DESIGN, TIME AND SETTING: Randomized controlled animal study This study was performed in Department of Toxicology, Public Health College of Jilin University from March 2006 to March 2007.MATERIALS: Fifty healthy female Wistar rats aging 2 months and six 1-week-old female Wistar rats were used for extraction of BMSCs. Rabbit-anti-nerve growth factor (NGF) monoclonal antibody was provided by Santa Cruz Company. METHODS:BMSCs were separated and cultured with adherent method. In the 3rd generation, BMSCs were preiabeled with bromodeoxyuridine (BrdU) 48 hours before transplantation. Fifty healthy Wistar rats were selected to prepare sciatic nerve crush injury models with clamping method.Subsequently, rats were randomly divided into transplantation group and control group, with 25 rats in each group. Rats in the transplantation group underwent transplantation of BrdU-labeied BMSCs at nerve injured sites; while, the same volume DMEM was injected into rats in the control group. MAIN OUTCOME MEASURES: Injured nerve in the transplantation group suffered from anti-BrdU staining 1, 2, 4, and 6 weeks after surgery. Distal injured nerve in both groups suffered from NGF immunohistochemical staining 1, 2, 4, and 6 weeks after surgery. Image analysis system was adopted to analyze integrated absorbance of positive expression. Gait analysis was performed every week after surgery to measure sciatic nerve function index, and it was also adopted to measure regenerated nerve conduction velocity 6 weeks after surgery. Subsequently, amount and inner diameter of medullated nerve fibers were calculated after luxol fast blue staining, while wet weight of experimental-lateral gastrocnemius muscle and cross section area of muscle fiber were measured at the same time. RESULTS: Fifty rats were included in the final analysis. BrdU-labeled positive cells could be found at injured nerve in the transplantation group 1, 2, and 4 weeks after surgery. Integrated absorbance of NGF protein expression in the transplantation group was significantly higher than that in the control group 1 and 2 weeks after surgery (P < 0.01), but there were no significant differences between the two groups 4 and 6 weeks after surgery (P > 0.05). Sciatic nerve function index in the transplantation group superiorly recovered to that in the control group 3-6 weeks after surgery. Furthermore, 6 weeks after surgery, nerve conduction velocity, amount and diameter of medullated nerve fibers, wet weight and cross section area of gastrocnemius muscle in the transplantation group were significantly higher than those in the control group (P < 0.05-0.01). CONCLUSION: BMSCs can be transplantated into injuried nerve tissue, and promote the recovery of nerve function in the micro-enviroment, improve NGF expression in an early phase may be one of its mechanisms.

BACKGROUND:Bipolar femoral head prosthesis has achieved the desired repair effect in patients with femoral neck fracture, but there is stil much controversy on the biomechanical properties of bipolar artificial femoral head prosthesis. OBJECTIVE:To compare biomechanical properties of the bipolar femoral head prosthesis replacement and internal fixation in the repair of femoral neck fracture in the elderly. METHODS:Twenty-three (46 sides) senile femoral neck fracture specimens were analyzed and randomized into internal fixation group(n=23)and bipolar femoral head prosthesis replacement group (n=23). Specimens in the internal fixation group underwent conventional metal implant fixation. Specimens in the bipolar femoral head prosthesis replacement group underwent bipolar femoral head prosthesis replacement. Mechanical properties of femoral prosthesis stem were tested on universal testing machine. Biomechanical properties after bipolar femoral head prosthesis replacement and internal fixation were compared. RESULTS AND CONCLUSION:(1) The maximum loadwassignificantly higher in the bipolar femoral head prosthesis replacement group than in the internal fixation group (P< 0.05). The maximum load trend images showed that the maximum load was significantly higher in the bipolar femoral head prosthesis replacement group than in the internal fixation group (P< 0.05). (2) The displacement in axial pul test was significantly shorter in the bipolar femoral head prosthesis replacement group than in theinternal fixation group (P< 0.05). The displacement trend images exhibited that the displacement in axial pul test was significantly shorter in the bipolar femoral head prosthesis replacement group than in the internal fixation group (P< 0.05). (3) These findings suggest that compared with the implant, bipolar femoral head prosthesis replacement in the repair of femoral neck fracture in the elderly is more stable, has better repair effects, can elevate hip function and obtain good initial stability.

Objective To improve detectable rate of gastric schwannoma by endoscopic ultrasonography (EUS). Method Clinical data and endoscopic ultrasonography (EUS) imaging features of 4 cases were retrospectively ana-lyzed which diagnosed as gastric schwannoma pathologically and immunohistochemically while diagnosed as gastric stromal tumor by EUS from May 2008 to June 2015 and reviewed the literature. Results 4 cases of gastric schwan-nomas are female and benign, all 4 lesions are solitary, 3 in gastric body, and 1 in fundus by endoscopic. By EUS, all lesions are originated from muscularis propria, hypoechoic change, even echoes and clear board without calcifica-tion or cystic changes. 2 cases have halo artifacts around the lesion. Literature review found that gastric schwannoma tended to occur in female, halo artifacts could be the feature of gastric schwannoma, calcification or cystic changes were rare in gastric schwannoma which were common in gastric stromal tumors. Conclusion It was difficult to distin-guish gastric schwannoma and gastric stromal tumors that originated from muscularis propria by EUS. For female patients with lesions originated from muscularis propria, originated from muscularis propria and occurred in gastric body, it was necessary to observe lesions whether there was being calcification or cystic and halo artifacts. Integrated all these performance, we should be in consideration of gastric stromal tumors, meanwhile, excluding the possibility of gastric schwannoma.

Objective: To provide a scientific standard of left ventricular Tei index for healthy people from various region of China, and to lay a reliable foundation for the evaluation of left ventricular diastolic and systolic function. Methods: The correlation and principal component analysis were used to explore the left ventricular Tei index, which based on the data of 3 562 samples from 50 regions of China by means of literature retrieval. hTe nine geographical factors were longitude(X1), latitude(X2), altitude(X3), annual sunshine hours (X4), the annual average temperature (X5), annual average relative humidity (X6), annual precipitation (X7), annual temperature range (X8) and annual average wind speed (X9). ArcGIS sotfware was applied to calculate the spatial distribution regularities of letf ventricular Tei index. Results: hTere is a signiifcant correlation between the healthy people’s letf ventricular Tei index and geographical factors, and the correlationcoeffcients were 0.107 (r1), 0.301 (r2), 0.029 (r3), 0.277 (r4),?0.256(r5),?0.289(r6),?0.320(r7), 0.310 (r8) and 0.117 (r9), respectively. A linear equation between the Tei index and the geographical factor was obtained by regression analysis based on the three extracting principal components. hTe geographical distribution tendency chart for healthy people’s letf Tei index was iftted out by the ArcGIS spatial interpolation analysis. Conclusion: hTe geographical distribution for letf ventricular Tei index in China follows certain pattern. hTe reference value in North is higher than that in South, while the value in East is higher than that in West.

Objective To explore the influence of glucose-lowering rate on left ventricular function in patients with type 2 diabetes mellitus (T2DM). Methods One hundred and thirty-two cases of type 2 diabetes mellitus and 135 cases of type 2 diabetes mellitus with coronary heart disease (T2DM+CHD)received intensive glucose lowering therapy. Then, after measuring left ventricular ejection fraction (LVEF) and E/A ratio, the variation was analyzed. Results LVEF was significantly higher than that before intensive therapy in T2DMsubgroup with glucose-lowering rate less than 6 m mol · L-1 · d-1( P＜0.05 ). So was T2DM+CHD subgroup with glucose-lowering rate less than 4 mmol· L-1 · d-1 (P＜0.05). LVEF was significantly lower than that before intensive therapy in T2DM+CHD subgroup with glucose-lowering rate greater than 4 mmol · L-1 · d-1( P＜0. 05 ),while by the end of following up for 3 months, LVEF stepped up and no significant difference was observed between subgroups ( P ＞ 0. 05 ). The E/A ratio stepped up in both subgroups after intensive therapy ( P ＜ 0. 05 ).Conclusions For T2DM patients with coronary heart disease, excessively fast glucose-lowering rate may impair left ventricular function. Long-term good control of blood glucose restores the impaired left ventricular function causes by excessively fast glucose-lowering rate. After intensive therapy, left ventricular diastolic function finally improves in both subgroups regardless of the glucose-lowering rate and coronary heart disease.

Stroke has increasingly become one of the three major diseases threatening human beings,among which acute ischemic stroke is the most common.Intravenous thrombolysis has become the first choice for acute ischemic stroke,but a large number of studies have shown that intravenous thrombolysis increases the risk of hemorrhagic transformation.The latest advances in clinical types,incidence,mechanism and risk factors of hemorrhagic transformation after thrombolysis with recombinant human tissue plasminogen activator are reviewed in this article,and the possible predictors of hemorrhagic transformation are discussed,aiming to provide new reference for clinical thrombolytic therapy.

Objective To establish the quantitative standard of intraepidermal nerve fibers in healthy Chinese and provide reference basis for the early diagnosis of peripheral neuropathy through the large sample system of quantitative research by skin biopsy.Methods Adult skin samples of different anatomical locations,age and gender were obtained from 192 healthy volunteers who performed skin biopsies in our hospital from May 2009 to July 2013;they were divided into 6 groups according to different anatomic sites (distal upper arm,distal forearm,opisthenar,proximal thigh,distal crus and acrotarsium) and 4 groups according to the ages (patients under 20 years old,patients of 21-40 years old,patients of 41-60 years old and patients older than 61 years).Quantitative observation of the intraepidermal nerve fibers was performed by skin biopsy and immunohistochemical technique.Half males and half females were chosen.Results The comparison of intra epidermal nerve fiber density (IENFD) among thigh,leg,dorsum of foot and the comparison among upper arm,forearm,dorsum of hand showed statistical significance (P＜0.05).Along with the limbs part from proximal to distal,the IENFD in the upper and lower limbs both manifested a degressive tendency by degrees (normal reference value ranges of each anatomic site:upper arm＞320.00 fibers/mm2,forearm＞190.57 fibers/mm2,opisthenar＞184.37 fibers/mm2,thigh＞418.36 fibers/mm2,crus＞157.35 fibers/mm2,and acrotarsium＞ 140.00 fibers/mm2).The IENFD among patients under 20 years old,patients of 21-40 years old,patients of 41-60 years old and patients older than 61 years did not show statistically significant differences (P＞0.05).The IENFD between patients under 20 years old and patients older than 61 years showed statistical significance (P＜0.05).The IENFD in male and female adults did not show statistical significance (P＞0.05).Conclusions A significant difference of IENFD is observed among different anatomic sites.Ages has small effect on IENFD,and gender has no effect on IENFD.

Objective To explore the morphological characteristics of intraepidermal nerve fibers in healthy Chinese by skin biopsy,to provide reference basis for the early diagnosis of peripheral neuropathy.Methods Skin biopsies samples were obtained from 192 healthy volunteers (half male and half female,collected in our hospital from June 2009 to August 2013),and these samples were divided into 6 groups according to different anatomic sites (far-end of the upper arm,far-end of the forearm,opisthenar,near-end of thigh,far-end of crus and acrotarsium) and 4 groups according to age (patients of younger than 20,patients of 21-40 years old,patients of 41-60 years old and patients of older than 61).Morphological observation of the intraepidermal nerve fibers was performed by skin biopsy and immunohistochemical technique.Results Various branch models emerged at each location:non-branching,branching at the epidermis-dermis junction,branching near the epidermis-dermis junction,branching at faraway side of epidermis-dermis junction,and branching near the cuticle.Branch models showed no significant diferences among patients of different ages.The above branch models appeared in far-end of the upper arm,far-end of the forearm,opisthenar,near-end of thigh,far-end of crus and acrotarsium,and as body based site famess,skin nerve fibers usually had more branches,and more axon expansion and varicose.Conclusions The age and lanatomic sites do not affect the branching pattems of intraepidermal nerve fibers.The closer to the extremities,the more branches of the intraepidermal nerve fiber.

OBJECTIVE: To observe the status of protein kinase B(Akt) signaling pathway in Akt phosphorylation induced by free silica(SiO_2) in mouse monocyte macrophage cell RAW264.7, and the role of Akt signaling pathway in early inflammatory response of silicosis. METHODS: i) RAW264.7 cells were routinely cultured and divided into SiO_2 stimulation groups at 5 different time points, and were stimulated for 15, 30, 60, 120 and 240 minutes with SiO_2 suspension with a final concentration of 100 mg/L, and a control group without SiO_2 treatment. At the end of treatment, the cells were collected and the expression of phospho-(Ser/Thr) Akt(p-Akt) was detected by Western blotting to select the optimal time of treatment. ii) RAW264.7 cells were divided into control group(no treatment), SiO_2 exposure group(previous concentration of 100 mg/L SiO_2 suspension) and intervention group(pre-treated with Akt activation inhibitor deguelin for one hour and then treated with 100 mg/L SiO_2 suspension), samples were collected after incubation for 60 minutes. The p-Akt expression and distribution in cells were detected by cellular immunofluorescence assay, the relative expression of p-Akt in cells was detected by Western blotting, and the levels of tumor necrosis factor-α(TNF-α) and transforming growth factor-β1(TGF-β1) in the supernatant of cells were detected by enzyme-linked immunosorbent assay. RESULTS: i) The optimal treatment time of RAW264.7 cells for SiO_2 exposure model was 60 minutes in vitro. ii) The results of cellular immunofluorescence assay showed that Akt phosphorylation was activated in RAW264.7 cells after stimulant with SiO_2, and the fluorescence of p-Akt was enhanced in the SiO_2 exposure group than the control group, and in the intervention group it was relatively weaker than the SiO_2 exposure group. The relative expression of p-Akt as well as the levels of TNF-α and TGF-β1 in the SiO_2 exposure group and the intervention group were higher than that in the control group(P<0.05), and the above three idexes in the intervention group were lower than the SiO_2 exposure group(P<0.05). CONCLUSION: Akt signaling pathway is involved in the process of SiO_2-induced macrophages phosphorylation, and participates in the early inflammatory response of silicosis.

OBJECTIVE: To explore the effect of wearing earphone to listen to music on the high-frequency noise-induced hearing loss(NIHL) in noise-exposure workers. METHODS: A total of 651 male noise-exposure workers in an automobile manufacturer were selected as study subjects by using judgment sampling method. The level of noise exposure in the individuals and the pure tone hearing threshold were tested. According to the frequency of wearing earphone to listen to music after work, the subjects were divided into low-, medium-and high-frequency earphone-using groups, with 60, 436 and 155 workers in each group, respectively. The effects of wearing earphone to listen to music combined with occupational noise exposure on high-frequency NIHL were analyzed. RESULTS: The high-frequency NIHL detection rate of the study subjects was 31.3%(204/651). The detection rate of high-frequency NIHL in these three groups from low to high was low-, medium-and high-frequency earphone-using groups(P<0.01). The detection rate of high-frequency NIHL in the high-frequency earphone-using group was higher than that of the low-and medium-frequency earphone-using groups(43.2% vs 25.0%, 43.2% vs 28.0%, P<0.01). Multivariate logistic regression analysis showed that wearing earphones to listen to music was a risk factor for high-frequency NIHL in noise-exposure workers(P<0.01) after eliminating the influence of confounding factors such as age, length and level of noise-exposure, and wearing anti-noise ear plugs. The higher frequency of wearing earphone to listen to music, the higher risk of high-frequency NIHL. CONCLUSION: Wearing earphone to listen to music after work and occupational noise exposure had a synergistic effect on high-frequency NIHL in noise-exposure workers.