Objective To explore the applicability of the Perceived Stress Scale(PSS) in Chinese medical students.Methods 773 medical students completed the PSS and the Depression Anxiety Stress Scale (DASS).The reliability and validity of the PSS were analyzed.Results The exploratory factor analysis showed that two factors were extracted from the scale,which could explain 53.74％ of the total variance.The confirmatory factor analysis verified that the structure of the PSS was two-dimensional (x2/df =2.863,CFI =0.943,TLI =0.924,GFI =0.951,AGFI =0.921,RMSEA =0.07).The internal consistency coefficient of the PSS,the perceived stress subscale and the perceived coping ability subscale were 0.858,0.852 and 0.750.The relationship between the PSS and the DASS was significant,which demonstrated that the PSS had a good criterion-related validity.In addition,t-test showed that girls had a higher level of the perceived stress than boys (t =-2.574,P =0.01),and students who lived in rural had a higher level of the perceived stress than students who lived in urban (t =2.788,P =0.005).Conclusion The study indicates that the PSS has a high level of the reliability and validity,and it is worthy of exploring the perceived stress in medical students.

[ ABSTRACT] AIM:To observe the inhibitory effect of madecassoside on the LPS-stimulated microglia and to inves-tigate its possible mechanism.METHODS:Microglia cells of neonatal Sprague-Dawley ( SD) rats were cultured, isolated and purified.Microglia cells were activated with lipopolysaccharide ( LPS) .The inhibitory effect of madecassoside on micro-glia was measured by MTT assay.Tumor necrosis factor alpha (TNF-α), interleukin 1β(IL-1β) were detected by ELISA. Cell cycle and apoptotic rate were evaluated by flow cytometry.The expression of TLR4 was detected by Western blotting. The expression of NF-κB was detected by RT-PCR.RESULTS: LPS induced the proliferation of microglia and release in-flammatory cytokines significantly.Compared with LPS group, madecassoside inhibited the proliferation of microglia induced by LPS in a dose dependent manner.The IC50 value of madecassoside was 10.97 nmol/L to microglia after incubation for 48 h.Madecassoside also decreased the levels of TNF-αand IL-6, increased the ratios of microglia at the G2 phase and the ap-optotic rate, decreased the expression of TLR4 and NF-κB significantly (P<0.05).CONCLUSION:Madecassoside has in-hibitory effects on the proliferation of LPS-stimulated microglia, by which the mechanism may be related to inhibition of the expression of TLR4 and NF-κB, change of cell cycle distribution and induction of microglia apoptosis.

BACKGROUND: How to effectively harvest bone marrow mesenchymal stem cells with homogeneity is crucial for cartilage tissue engineering research. OBJECTIVE: To isolate and culture rat bone marrow mesenchymal stem cells and to observe biological characteristics of the cells. METHODS: Bone marrow mesenchymal stem cells were isolated from the femur and tibia of 30 Sprague-Dawley rats using the whole bone marrow adhesion method. Cell surface markers were identified using flow cytometry, cell proliferation ability was observed through cell counting, and cell survival rate was determined by MTT assay. RESULTS AND CONCLUSION: The harvested cells were mostly round and oval, which partially showed a triangular shape. Cell fusion appeared after 12-15 days of inoculation. The proliferation of passaged cells was accelerated. Two hours after passage, the cells evenly covered the bottom of the culture dish. With the increasing of cell generations, the cell proliferation ability was gradually decreased. The survival rates of cells at passages 1-5 were over 95%, significantly higher than those at passages 6 and 7 (P < 0.05). The harvested cells were negative for CD34, but positive for CD44. To conclude, the whole bone marrow adhesion method is effective to isolate rat bone marrow mesenchymal stem cells with stable growth and strong proliferation ability. Passage 5 cells can be selected as seed cells for cartilage tissue engineering.

Background Evaluation of intra-retinal layer thickness plays an important role in the diagnosis and monitor of various eye diseases,and spectral domain optical coherence tomography (OCT) is a frequently used tool.Software analysis method was used to measure the retinal thickness in previous study,but the study on the reliability of automatic layered software is lack.Objective This study was to evaluate the repeatability and reproducibility of thickness profile measurement of intra-retinal layers determined by an automated algorithm applied to OCT images from RTVue100 OCT instrument.Methods In this prospective cross-sectional study,retinal thickness images at 6 mm around fovea were obtained from 18 right eyes of 18 normal subjects with RTVue100 OCT instrument.The retinal images were segmented into retinal nerve fiber layer (RNFL),ganglion cell layer and inner plexiform layer(GCL+IPL),inner nuclear layer (INL),outer plexiform layer (OPL),outer nuclear layer (ONL),inner segment (IS),outer segment (OS) and retinal pigment epithelial (RPE) layer using automated algorithm method.Then Matlab software was used to analyze the measuring outcome.Interclass correlation coefficient (ICC) and coefficients of reproducibility (COR) were calculated from the results of two-time examination by the same examiner to evaluate the repeatability and from the results of two different examiners to assess the reproducibility.Written informed consent was obtained from each subject prior to any medical procedure.Results The entire retinal thickness measured by RTVue-OCT was (303.22± 14.10) μm in the horizontal meridian and (306.68 ± 13.32) μm in the vertical meridian,with the maximum values of retinal thickness in the GCL+ IPL and ONL.Whether in the horizontal meridian or in the vertical meridian,the ICC and COR were ＜0.60 in the OPL,IS and OS;while those in the RNFL,GCL+IPL,INL,ONL and RPE layer were ＞0.70.Conclusions RTVue OCT with automated algorithm is a useful and reliable approach to the measurement of intra-retinal layer thickness.Automated segmentation can offer accurate and repeatable thickness profile of OCT retinal image.This method may improve the diagnosis and monitoring of retinal diseases.

Objective To observe the feasibility of posterior internal fixation with pedicle screw rod system for upper cervical vertebra injury. Methods 16 patients with upper cervical vertebra injury accepted posterior pedicle screw system internal fixation were reviewed. Results Venous plexus behind C2 damaged in operation in a case, who needed a microscope for hemostasis. No complication, such as neurological symptoms worse, cerebrospinal fluid leakage, hematoma and infection of incision happened post operation. The neurological symptoms improved 81.8% in all the 7 cases who complained before operation. No complication was found in the follow-up 3 to 18 months after discharge. Their activities of upper cervical was basically unaffected. Conclusion Posterior internal fixation with pedicle screw rod system can provide stable support for patients with upper cervical injury.

Objective To evaluate the efifcacy and inlfuencing factors of 3%hypertonic saline (HS) inhalation in treatment of bronchiolitis. Methods Clinical data together with the detection of 16 types of respiratory tract virus from hospitalized pediatric patients with primary diagnosis of bronchiolitis from June 2009 to December 2012 were retrospectively analyzed. The endpoint indicators for evaluation on the efifcacy of nebulized 3%HS inhalation were the percent decrease of clinical severity (CS) score after 2 days' treatment and the hospitalization time. Factors affecting efifcacy were further explored. Results The CS score in nebulized 3%HS treated group decreased in average of 42.86%(11.11%-66.67%), signiifcantly higher than that (26.79%, 0.00%-50.00%) in the untreated group (P=0.006). No difference of between the two groups (P=0.26). Multiple linear regression analysis showed that nebulized 3%HS inhalation has better efifcacy on the patients older than 3 months having breastfeeding, respiratory synthetic syncytial virus (RSV) infection and extensive wheezing sound auscultation of the lungs. The multiple linear regression analysis model was statistically signiifcant (R2=0.58, P<0.001). Conclusions After 2 days' treatment with 3%hypertonic saline inhalation, the CS score of bronchiolitis patients was decreased. The treatment can be recommended in hospitalized patient older than 3 months with breastfeeding, RSV infection, and extensive wheezing sound auscultation of the lungs.

Objective To study the effectiveness of niacinamide in treating maintenance hemodialysis patients with hyperphosphatemia.Methods It was a prospective and randomized controlled trial.Patients with hyperphosphatemia (serum phosphate ＞ 1.45 mmol/L) were randomly assigned into two groups:control group (continue their original phosphate binder and rocaltrol treatment) and niacinamide therapy group (additionally received niacinamide,titrated from 600 mg/d to 1200 mg/d).The treatment lasted for 8 weeks.Serum phosphate and calcium were tested every 2 weeks and normalized protein catabolic rate and other relevant indexes were tested monthly.Results 100 patients were recruited and 93 of them completed the trial,including 44 from the therapy group and 49 from the control group.By the repeated measures analysis of variance,changes of serum phosphate in two groups displayed a statistical significant difference,but the levels of serum calcium in both remained steady.At the end of trial,compared to control group,therapy group appeared decreased serum phosphate levels [(1.59±0.36) mmol/L vs (1.94±0.25) mmol/L,P ＜ 0.001] and increased serum HDL levels [(1.32±0.54) mmol/L vs (1.09±0.41) mmol/L,P=0.02].Meanwhile,two groups showed no significant difference in intact parathyoid hormone and alkaline phosphatase.Adverse reactions including thrombocytopenia and gastrointestinal dysfunction were observed in niacinamide therapy group.Conclusions Niacinamide is effective on controlling hyperphosphatemia along with phosphate binder in maintenance hemodialysis patients.It also increases the serum HDL levels.Nonetheless,it is important to monitor the number of platelet.

Objective To study the set-up errors by CBCT in IMRT with two different immobilization techniques for thoracic and abdominal tumors.Methods Sixty patients with thoracic and abdominal tumor were included in this study and separated into study group and the control group.The study group were immobilized with carbon fiber holder,vacuum bag and thermoplastic mask.The control group were immobilized with carbon fiber holder and thermoplastic mask.CBCT scan and auto-match online were regularly performed before the treatment.The setup of left-right(x),superior-inferior(y),anterior-posterior (z) were received.The value of the Mptv was calculated,meanwhile.The grouped t-test of was carried out between these two methods.Results The shift errors in x-,y-,z-dimension of the study group were (0.32 ± 2.58) mm,(-0.40 ± 3.89) mm,(-0.75 ± 2.43) mm.The Mrrv were 5.60 mm,6.08 mm,6.32 mm.The translation set-up errors in x-,y-,z-dimension of the control group were(0.62 ±3.60),(2.44 ± 4.93),(0.66 ±2.85) mm,respectively.The MPrv were 8.07,10.63,6.90 mm,respectively.The t-test value were t =-0.78,-5.11,-4.22,P =0.440,0.000,0.000,respectively.Conclusions The immobilization techniques with carbon fiber holder,vacuum bag and thermoplastic mask would be better than the techniques without the vacuum bag in reducing the setup errors.

Glomus Tumor ; pathology ; Humans ; Skin Neoplasms ; pathology

Objective To investigate the single nucleotide polymorphism at G-395A site of the Klotho (KL) gene and to analyze its correlation with the coronary heart disease(CHD) and serum Cystatin C(Cys C) level in the elderly Chinese Han population in central China.Methods A case-control study was conducted in 278 elderly Chinese Han population in this department,who were divided into CHD group(138 cases)and control group(140 cases) according to bear angiography coronary or not.G-395A polymorphism of KL gene was determined by TaqMan Gene probe method,and the relationship between G-395A polymorphism and coronary heart disease and serum Cys-C level was analyzed.Results Compared with the control group,the frequency of GG genotype of G-395A in CHD group was significantly higher,and the frequency of AA genotype and AG genotype was not statistically significant.The levels of Cys-C in the GG genotype were higher than those in the AA and AG genotypes both in the control group and coronary heart disease group.Conclusion In the elderly Han population in central China,the risk of suffering coronary heart disease is higher among the GG genotype of the G-395A locus of the KL gene.KL gene G-395A site gene mutation may affect the development of atherosclerosis by affecting blood Cys-C levels.