A century ago the Flexner Report facilitated the process of modern medical education reform.Half a century ago,Problem-based learning initiated the student-centered medical education model.At present training medical students' competency will usher in the third reform in medical education.Over 100 years' development and in the global context of current medical education reform,China's medical education has become an important part of the world medical education.Harbin Medical University conducted an all-around reform through international cooperation and received the accreditation referenced according to global standards in medical education,which is an epitome of the medical education reform in China.

Ephedrae Radix Et Rhizoma is a traditional Chinese medicine, and the effect of antiperspirant has been recorded in books on Chinese medicines in all dynasties. By referring the relative literatures on Ephedrae Radix Et Rhizoma from home and abroad, the study progress in the chemical constituents, pharmacological actions and clinical application of Ephedrae Radix Et Rhizoma in the latest 40 years were reviewed to lay foundation for the reasonable exploitation and utilization of Ephedrae Radix Et Rhizoma.

BACKGROUND:Artificial femoral head replacement provides a new idea for the repair of unstable intertrochanteric fracture. Artificial prosthesis replacement may affect original femoral biomechanical stability and lead to a variety of adverse consequences. OBJECTIVE:To analyze the stress distribution of femoral head replacement in the treatment of unstable femoral intertrochanteric fractures with three-dimensional finite element analysis. METHODS:One male old volunteer was randomly selected from population who underwent health examination. The left femur was scanned with spiral CT, and the three-dimensional finite element models of the human femur and prosthesis were established. The three-dimensional finite element model was used to simulate the actual working conditions of human climbing stairs, and the stress distribution of the bone channels around the surface of the femur and the prosthesis was analyzed with three-dimensional finite element analysis. RESULTS AND CONCLUSION: Under normal condition, the stress of the human femur was in a consistent state. Stress changed gradualy from the proximal end to the distal end. The stress of the prosthesis was concentrated in the middle section. The prosthesis of inner stress distribution was analyzed to obtain stress distribution of prosthesis and femur cancelous bone interface. The analysis found that stress change trend was consistent. The results suggest that artificial femoral head replacement does not have a significant effect on the overal stress distribution of the human femur, and the overal stress distribution does not change, and the maximum stress region is located in the middle of the whole femur. After the reconstruction, the stress concentration of the femur is not observed.

Objective To study and evaluate mini-titanum-plates the effects applied to four limbs bone and joint fracture.Methods 132 patients in our hospital suffered from four limbs fractures treated with open reduction internal fixation of Medicon mini-plate from February 2004 to June 2013 were studied retrospectively,including 60 cases of metacarpal and phalanx fracture(93 lesions),37 cases of metatarsal and phalanx fracture(62 lesions),15 cases of radial head fracture,9 cases of scaphoid fracture,4 cases of coronoid process of ulna fracture,4 cases of patella frature,3 cases of condyles of femur.Results Clinical outcomes:hands and feet group:follow-up postoperative 8-12 months,evaluation results showed that excellent was 78cases,good was 66cases,poor was 11cases,good rate was 92.9％.group of radius head fracture:Fractures got osteal union after 6 months to 1 year.good rate was 93.3％.group of scaphoid bone fracture:Fractures got osteal healing.all cases adopt improved Mayo Evaluation Wrist Function to evaluate,good rate was 88.9％.Including 4 cases of Coronoid process of ulna fracture,4 cases of patella fracture,3 cases of femoral condylar fracture,the excellent good rates was 100％.Conclusions Metacarpal and metatarsals phalanx fracture treated with mini-plate can get reduction anatomically,control rotation,prevent malformation and keep compression,they are the ideal internal fixation material;free fragments for intra-articular fracture fixed by mini-titanum-plate and screws can get reduction precisely,be fixed satisfactory,also can choose the appropriate application.

Objective To construct a chimeric infectious clone of the fatal virulent strain SDLY 107, containing the gene fragments encoding 2A and 3B proteins of the mild virulent strain SDLY 1, and to establish a reverse genetic system platform for further investigation on virulence of enterovirus 71 strains. Methods The overlap PCR analysis was performed to obtain the gene fragments encoding 2A and 3B pro-teins of the mild virulent strain SDLY 1.The obtained gene fragments were digested and then cloned into a plasmid pMD19-T containing the full-length gene of SDLY 107 strain by using gene replacement strategy. The recombinant RNA was transfected into Vero cells for the preparation of recombinant virus particles.Sev-eral assays including the PCR, indirect immunofluorescence ( IFA) , Western blot and sequencing were per-formed for virus identification.Virus titers were measured by 50%cell culture infective dose ( CCID50 ) and plaque assay.Results The infectious clones of SDLY 107-2A-1 and SDLY 107-3B-1 chimeric virus strains were constructed successfully.Typical cytopathic effect was observed in Vero cells after viral transfection. Identification of the rescued viruses by PCR, IFA, Western blot and sequencing further confirmed the suc-cessful construction of infectious virus strains.The virus titers of SDLY 107-2A-1 and SDLY 107-3B-1 strains detected by CCID50 and plaque assay were 1.25 ×105 PFU/ml and 0.7 ×105 PFU/ml, respectively. Conclusion The chimeric viruses SDLY 107-2A-1 and SDLY 107-3B-1 were rescued successfully, causing cytopathic effects similar to those by using the parental virus strain SDLY 107.This study might pave the way for further investigation on in vitro and in vivo virulence of enterovirus 71 strains.

OBJECTIVETo investigate the effect of low-molecular-weight heparin (LMWH) combined with paclitaxel (PTX) on the invasiveness and migration of nasopharyngeal carcinoma cells and explore the molecular mechanisms.

METHODSMTT assay was used to detect the growth inhibition induced by LMWH and PTX in CNE1 and CNE2 cells. Wound healing assay and Transwell migration assay were employed to assess the effects of the drugs on the cell migration, and Transwell invasion assay was used to evaluate the cell invasiveness. The cellular expression of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) were analyzed by Western blotting. ELISA was used to determine the expression of heparanase (HPA) in the culture medium of the cells.

RESULTSMTT assay showed an obvious suppression of CNE1 and CNE2 cell proliferation in response to LMWH and PTX treatments. Treatment with 200 U·ml LMWH combined with 0.1 µmol·L PTX for 24 h resulted in the inhibition rates of migration of 66.70% and 70.53% in CNE1 and CNE2 cells, respectively significantly higher than the rates in cells with PTX treatment alone. The combined treatment with LMWH and PTX for 24 h also caused a significantly higher inhibition rate of cell invasion than LMWH and PTX alone. LMWH enhanced the down-regulation of MMP-9 and HPA induced by PTX.

CONCLUSIONLMWH can enhance the inhibitory effect of PTX on the migration and invasion of nasopharyngeal carcinoma cells, the mechanism of which may involve the down-regulation of MMP-9 and HPA expressions.

Carcinoma ; Cell Line, Tumor ; Cell Movement ; drug effects ; Cell Proliferation ; drug effects ; Glucuronidase ; metabolism ; Heparin Lyase ; metabolism ; Heparin, Low-Molecular-Weight ; administration & dosage ; pharmacology ; Humans ; Matrix Metalloproteinase 9 ; metabolism ; Nasopharyngeal Neoplasms ; pathology ; Paclitaxel ; administration & dosage ; pharmacology ; Tissue Inhibitor of Metalloproteinase-1 ; metabolism

Objective: To investigate the effects on human peripheral blood erythrocytes of long-term occupational contact with chromate. Methods: A dynamic cohort study was conducted of chromate-exposed workers (343 cases) and non-chromate-exposed workers (73 cases) at a chromate production enterprise who were selected according to specific inclusion and exclusion criteria from 2010 to 2015. Personal information and chromate exposure information were obtained by questionnaire. A generalized estimating equation was employed to analyze the effects on human peripheral blood erythrocytes of long-term occupational contact with chromate, controlling for age, gender, smoking, alcohol consumption and body mass index. Results: The mean ages and working ages of those entering the cohort study were 36.67 ±6.78 and 38.47 ± 7.18, respectively, for the exposure group and 8.39 ± 6.02 and 12.86 ± 8.34, respectively, for the control group. The erythrocyte content [(4.73±0.46), (4.81±0.53), (4.41±0.45)]×10¹²/L in the peripheral blood in the chromate exposure group was lower than that [(4.76±0.42), (4.95±0.45), (4.47±0.39)]×10¹²/L in the control group for the years 2010, 2011, 2012 and 2014 (t values were 0.38, 1.96, 0.92 and 1.21; P values were 0.703, 0.051, 0.358 and 0.227, respectively). The correlations between the years 2010 and 2011, 2011 and 2012, 2012 and 2014, and 2014 and 2015 were 0.667, 0.464,-0.070 and 0.020, respectively (P<0.001). The RR for males and those that consumed alcohol were 0.661 (95% CI: 0.616-0.709) and 0.910 (95% CI: 0.811- 1.201), respectively. Compared with the control group, the risk of reduced erythrocyte levels in the peripheral blood was increased by 0.915 (95% CI: 0.852- 0.982) in the chromate-exposed group. Conclusions The erythrocyte content of peripheral blood was reduced after long-term exposure to chromate. Maleness and alcohol consumption were factors that increased the risk of reduced peripheral blood erythrocytes in the chromate-exposed population.

Objective:To investigate the prevalence of Mycoplasma pneumoniae ( Mp) in children undergoing physical examination. Methods:This study randomly enrolled 1 303 children at the age of 6-12 years who underwent physical examination in 2023. Their oral and pharyngeal swabs as well as venous blood samples were collected. The prevalence of Mp in these subjects was detected using isolation and culturing, nucleic acid detection and serological test. Chi-square test was used for statistical analysis. Results:Among the 1 303 children, the detection rate of Mp was 4.1% (53/1 303) by culturing, 7.3% (95/1 303) by nucleic acid detection and 13.6% (177/1 303) by serological test. Statistical analysis showed that there were significant differences in the the detection rates of Mp among children undergoing physical examination between the three methods ( P<0.05). Conclusions:The detection rate of Mp in children undergoing physical examination in 2023 was about 4.1%. Isolation and culturing was more accurate than nucleic acid detection and serological test in the detection of Mp in healthy population as the latter two methods would overestimate the rate.

Objective To evaluate the relationship between clinicopathological features and central lymph nodes metastasis in patients with papillary thyroid microcarcinoma (PTMC),and aim to provide an appropriate operation in clinic.Methods The clinical data of 536 patients undergoing surgical treatment in Department of Thyroid Surgery,the First Affiliated Hospital of Zhengzhou University from January 2015 to December 2017,who had pathologically confirmed popillary thyroid microcarcinoma (PTMC) were retrospectively analyzed.Thyroidectomy and isthmectomy with central compartment neck dissection were performed in all patients.The patients were divided into two groups according to whether there existed central lymph node metastasis,and compared the differences of gender,age,number of cancer lesions,tumor breakthrough envelope,BRAFV600E gene mutation,and tumor maximum diameter in the central lymph node metastasis,respectively,by t-test x2-test.Univariate logistic regression analysis and multivariate binary logistic regression analysis were conducted to find risky factors.Results There existed difference between two groups by completing the gender,age,the BRAFV600E gene mutation and maximal tumor diameter(P ＜ 0.05).Univariate logistic regression analysis indicated that gender (P =0.046),age (P ＜ 0.01),maximal tumor diameter(P ＜0.01) and the BRAFV600E gene mutation(P =0.016) were significant predictors for central lymph nodes metastasis.And multivariate binary logistic regression analysis revealed that the rate of lymph node metastasis significantly increased in cases of larger tumor diameter(P ＜0.01),BRAFV600E gene mutation(P =0.035) and ageing below 45 years old (P ＜ 0.01).Conclusions The treatment for central lymph node metastasis of PTMC should be different considering elements including BRAF600E gene mutation prophylactic,ageing below 45 years old and larger tumor diameter.Therefore central lymphadenectomy should be performed when the primary lesion was resected.

ObjectiveTo observe the effect of Jiaji electroacupuncture combined with neurodynamic mobilization on nerve conduction velocity and the expression of Netrin-1, Slit2 and Rho GTPases after sciatic nerve injury in rabbits. MethodsA total of 216 New Zealand rabbits were randomly divided into nomal control group (NC), vector virus group (VV), Jiaji electroacupuncture combined with neurodynamic mobilization group (EN), Netrin-1 group (N1), Slit2 group (S2) and N1+S2 group. Each group was divided into three subgroups according to the postoperative treatment time points (one, two and four weeks), with twelve rabbits in each subgroup. The rabbit model of Sunderland Ⅲ degree injury of the left sciatic nerve was established by clamping method. There was no intervention in NC, and virus was injected during the preparation of the model. Jiaji electroacupuncture and neurodynamic mobilization were administrated three days after operation in EN group. Nerve conduction velocity of sciatic nerve was measured with electromyography. The sciatic nerve and L_4-6 spinal cords were obtained, the expression of Netrin-1 and Slit2 mRNA were detected real-time quantitative polymerase chain reaction and immunofluorescence double staining, and the expression of Rac1, Cdc42 and RhoA protein were observed via Western blotting. ResultsOne, two and four weeks after modeling, the nerve conduction velocity was more in EN group and N1+S2 group than in N1 group and S2 group (P < 0.05); the Netrin-1 and Slit2 mRNA expression were higher in the EN group and N1+S2 group than in the VV group and NC group (P < 0.05); the protein expression of Rac1 and Cdc42 were higher, and the protein expression of RhoA was lower in EN group and N1+S2 group than in N1 group, S2 group and VV group (P < 0.05). ConclusionJiaji electroacupuncture combined with nerve mobilization may promote the axonal regeneration by regulating the expression of Netrin-1 and Slit2, adjusting the imbalance of Rho GTPases enzyme system, and then promoting cytoskeleton reorganization and peripheral nerve regeneration after injury.