BACKGROUND:It is reported that long-term endurance training can induce the transformation of muscle fibers and the myosin heavy chain (MHC) isoforms from the fast type into the slow type. But the change of MHC isoforms mRNAs in the movement training needs further study.OBJECTIVE: To observe the effect of the treadmill training on the contractile function of gastrocnemius MHC in male SD rats.DESIGN: A randomized controlled animal experiment.SETTING: Medical Experimental Center of Xi'an Jiaotong University.MATERIALS: Totally 40 male SD rats aged 7 weeks with the body mass of (230±16) g were selected. All the animals had not experienced the treadmill exercise before the experiment. Reagents: The primary antibodies were the murine anti-actin and anti-MHC Ⅱ of fast contractile type of skeletal muscle monoclonal antibodies, ABCam products. The secondary antibody was the alkaline phosphatase-conjugated anti-murine IgG, SIGMA product.METHODS: The experiment was conducted at the Medical Experimental Center of Xi'an Jiaotong University from March to October 2005. All the rats were randomly assigned into control group (n =10) and training group (n =30). The rats in the training group took movement training for 4-6 weeks with the exercise intensity of 75%VO2max (18.5-24 m/min,gradient of 0°), once 50 minutes and twice a day. The rats in the control group did free exercise, and did not receive any intervention. At weeks 4, 5 and 6, MHC mRNA content was measured by reverse transcription-polymerase chain reaction (RT-PCR) and change of myosin muscle fibers and size of cross section area (CSA) were determined by immunohistochemical method in 10 rats. The rats were anesthetized before the gastrocnemius liberated gently. Tension transducer and electrical stimulator were applied to give square wave pulse stimulation. The gastrocnemius was extended gradually till the Lmax position of initial length of muscle, at which the isometric contraction tension reached the maximal value for 10 minutes. The muscle length and tension were recorded. The right-side gastrocnemius was obtained to measure the wet weight, and the ratio with the body mass was calculated. The ratio of muscle mass to body mass was determined by the following formula: muscle mass (mg)/body mass (g) ×100%.MAIN OUTCOME MEASURES: ①MHC mRNA content of gastrocnemius, ②change of myosin muscle fibers and size of CSA, ③body mass of rats and gastrocnemius mass, and ④maximal tension of isometric contraction of gastrocnemius.RESULTS: A total of 40 included rats were involved in the result analysis. ①MHC mRNA content of gastrocnemius: The expression of total MHC mRNA of the training group was 105% of that of the control group after the endurance training for 4 weeks (P ＜ 0.01). The expression of MHC Ⅱ a was higher than that in the control group (1.27±0.08,1.17±0.06, P ＜ 0.05). The expression of MHC Ⅱ x mRNA was higher than that in the control group (1.29±0.04,1.19±0.05, P ＜ 0.01 ).②change of myosin muscle fibers and size of CSA: the MHC of rats had the main expression of the Ⅱ slow contractile type of muscle fibers, but less expression of Ⅰ fast contractile type of muscle fibers ratio after 4-6 weeks aerobic exercise. The CSA of type Ⅰ and type Ⅱ muscle fibers of the rats in the control group were (1 958.0±30.5), (1 656.1± 35.3) μm2, respectively. However, as compared with the control group, the CSA of type I and type Ⅱ muscle fibers of the rats in the four-week-training group increased by 24.5 % and 22.1% (P ＜ 0.01) respectively. In the five-week-training group, the related value increased by 26.4 % and 51.5 % (P ＜ 0.01), respectively. In the six-week-training group, the related value increased by 33.2% and 48.9% (P ＜ 0.01), respectively. ③body mass of rats and gastrocnemius mass:The wet weight of gastrocnemius [(135.6±3.1 ), (139.2±5.1), (148.4±6.2) mg] was higher in the training group than the control group [(103.2±3.4), (87.5±2.9), (68.3±3.3) mg,P ＜ 0.01] at weeks 4, 5 and 6. Relative weight of gastrocnemius [(0.55±0.01), (0.56±0.02), (0.59±0.03)] was higher in the training group than the control group [(0.43±0.02), (0.37± 0.04), (0.29±0.05),P ＜ 0.05-0.01] at weeks 4, 5 and 6. ④maximal tension of isometric contraction of gastrocnemius:The maximal tension of isometric contraction increased significantly in the training group as compared with the control group after square wave pulse stimulation at week 6 (P ＜ 0.01).CONCLUSION: Expression of MHC Ⅱ x and MHC Ⅱ b, the CSA of muscle fibers and the maximal tension of isometric contraction are all increased after the short-term endurance training. It indicates that the aerobic exercise may promote the contractile function of MHC.

Objective To study the effect of 4- 6 weeks' treadmill training of male SD rats on the contractile function of their gnstroenemius myosin heavy chain (MHC). Methods Forty male SD rats were randomly divided into control group and training group. The treadmill training of the training group rats was incessantly performed for 4- 6 weeks at an intensity of about 75% VO2max (18. 5- 24 m/min, gradient of 0°, each training session lasting 50 minutes, twice a day). The content of gastrocnemlas MHC mRNA was tested by reverse transcription polymernse chain reaction (RT-PCR), and the changes of muscle fibre and its cross-section area (CSA) were measured using immunohistochemistry. Electric stimulation tests were used to determine the maximal tension of isometric contraction of the post-training gastrocnemius. Results ① After continuous treadmill training for 4 - 6 weeks, we found that the content of the total MHC, MHC Ⅰ , MHC Ⅱ x, MHC Ⅱ a mRNAs was 105%, 105%, 109% and 108% of that in the resting control group, respectively, and the MHC Ⅱ b mRNA content did not change significantly. The percentage of MHC Ⅰ mRNA in the total MHC mRNA increased while that of MHC Ⅱ mRNA decreased after aerobic training. ② The slow type of fibre type Ⅰ was the main part of the MHC after training and the CSA of the muscle fibres increased simultaneously. ③ The maximal tension of isometric contraction by pulse stimulation of square wave in the training group increased significantly compared with that in the control group (P<0. 01). Conclusion The findings indicate that aerobic exercise may promote an increase in the contractile function of MHC.

The second class is not only a useful supplement to the first class but also an effective way to improve the comprehensive quality and ability of students.Through the deliberate research training and laboratory work,the second class of scientific research facilitates the medical students' developing scientific thinking,expanding professional knowledge,enhancing the ability to do scientific research and cultivating the spirit of teamwork.

BACKGROUND:Stem cel transplantation has incomparable superiorities in the treatment of cardiovascular diseases. But stem cel s have a very low efficiency to differentiate into myocardial cel s spontaneously, and there are many factors influencing stem cel differentiation. OBJECTIVE:To clarify the pros and cons of different sources of stem cel s in the treatment of myocardial infarction, to investigate the methods for improving the differentiation efficiency of myocardial cel s, optimal differentiation conditions and mechanism underlying exercise-induced stem cel mobilization and endogenous myocardial cel regeneration. METHODS:A computer-based search of CNKI and PubMed databases was performed by the first author for articles related to stem cel therapy for myocardial infarction and stem cel differentiation into myocardial cel s, exercise effect on stem cel proliferation and myocardial cel regeneration published from 1985 to 2015. The key words were“stem cel s, myocardial infarction, myocardial regeneration, cardiac cel , exercise”in Chinese and English, respectively. Final y, 54 articles were included in result analysis. RESULTS AND CONCLUSION:In recent years, a variety of chemical inducers and biological components have been used in the myocardial differentiation of stem cel s. Simulation of myocardial microenvironment and vascular cel growth factors are the main methods of inducing myocardial differentiation. Aerobic exercise-induced stem cel mobilization can induce ischemic cardiac angiogenesis and upregulate a variety of vascular endothelial growth factors so as to promote myocardial proliferation and repair. However, in-depth exploration is stil needed in the harvesting of stem cel s, transplant rejection, and regulatory mechanisms underlying the directed differentiation of stem cel s into cardiomyocytes.

Non-motor symptoms are an important component of the manifestations of Parkinson's disease(PD);they usually include sleep disorder,neuropsychotic symptoms,autonomic dysfunction,pain,and so on.Non-motor symptoms are multifactorial and mainly involve various non-dopaminergic neurotransmitter systems.These symptoms are not only a result of disease progression,but also can appear in the early stage of the disease,and they can have a major impact on the quality of life.The early notice of these symptoms may lead to better therapeutic strategies and subsequently to the improvement of the quality of life in PD patients.

Objective To report our clinical outcomes of treating tibial defects combined with soft tissue defects using Ilizarov technique.Methods From May 2010 to February 2015,52 patients with combined bone and soft tissue defects of the tibia were treated at our department.They were 41 males and 11 females,aged from 19 to 65 years (average,37.7 years).By Gustilo classification,49 cases were type ⅢB and 3 type ⅢC.The areas of soft tissue defect ranged from 7 cm ×3 cm to 28 cm × 15 cm,and the tibial defects ranged from 5 cm to 15 cm in length (average,12.6 cm).The schemes of Ilizarov technique depended on the location and size of the tibial defects.Open wound dressing combined with bone transport was adopted in 21 cases,limb shortening followed by bone lengthening with compression at the fracture ends in 12 cases,and tissue flap transplantation combined with bone transport or lengthening in 19 cases.Results The follow-up time of the 52 patients ranged from 13 to 61 months (average,27.1 months).The distance of bone transport or lengthening ranged from 5.0 cm to 13.6 cm (average,10.8 cm);the bone transport speed averaged 0.81 mm/day.The tibiae united in all the 52 patients;the time for external fixation ranged from 13 to 21 months (average,15.3 months);the external fixation index was 2.3 months/cm.According to the Paley functional criteria,23 cases were excellent,19 good,9 fair,and one poor,yielding an excellent to good rate of 80.7％.Conclusion According to the location and size of the bone and soft tissue defects of the tibia,the 3 schemes of Ilizarov technique can be rationally chosen to obtain fine clinical outcomes.

Objective To study the relationship between ultrasonographic appearance of the endometrium and the blood flow of uterine artery,ovarian stroma and VEGF in the spontaneous ovulating cycle.Methods A total of 30 women with normal ovulating function participated in this study.On the day of positive urinary LH,the subjects were divided into three groups(A,B and C) according to Gonen's criterions of endometrial echogenic patterns.The peak systolic velocity(PSV),end-diastolic velocity(EDV),resistance index(RI) in uterine arteries and ovarian stromal vessels were measured with transvaginal color Doppler ultrasonography;follicle-stimulating hormone(FSH),luteinizing hormone(LH),estradiol(E_(2)) and progesterone(P) were assessed by fluoroimmunoassay;and vascular endothelial growth factor(VEGF) was assessed by Enzyme-linked immunosorbent assay on the third day of the cycle,the pre-ovulating phase,and the 6～7 day after ovulation.Results ① During the pre-ovulatory phase uterine arteries and ovarian stromal blood flow PSV in group A was significantly higher than that in group C(P0.05).Conclusion Lower receptivity in the hyperechogenic endometrium may be related with corpus luteum defection and disorder of the uterine blood vessel activities.

Objective The purpose of the study was to explore influence of family factors on dietary behavior of primary and secondary studen t s in Guangzhou city, in order to provide suggestions for intervention of dietary behavi or. Methods The study population included 1 539 student-parent s pairs selected from Guangzhou city by using the method of stratified multistage cluster random sampling, and data were collected through questionnaires. Results The ratio of parents who often reminded and forced the ir children to eat some fo od they thought of as nutrition were 56.0% and 7.7%, and 39.7%, 29.2% of ch ildren complied with their parents, respectively. At dinner, 14.8% and 27.5% of parents often and sometimes criticized their children, and the ratio of childre n couldn't eat anything and only eat a little food were 5.9%,19.3%, respectively . Forty-two point three of primary and secondary school students watched televi sion wh en they had a dinner, which made 39.4% of students not eat seriously. C onclusions Dietary behavior of primary and secondary school students is influenced strongly by their parents and family environment, it is necessary for parents and themselves to grasp enough nutritional knowledge.

Objective To explore the clinical features and diagnostic method of primary natural killer( NK)/T cell meningeal lymphoma. Methods An unusual case of a 19-year-old male with primary NK/T cell meningeal lymphoma was reported. His clinical presentation and laboratory findings were discussed. The related literatures have been reviewed. Results The patient presented with diplopia,headache, vomiting and facial drooping at the onset, followed by progressive pain and weakness of the four limbs. Cerebrospinal fluid showed significant increase in pressure, leukocytes number, levels of protein,normal glucose and adenosine deaminase, negative tuberculosis antibody and sterile staining. In cerebrospinal fluid cytological analysis, May-Grunwald-Gimsa staining showed large number of atypical lymphocytes with irregular nucleus and nuclear fission, Ki-67 immunostaining showed extensive proliferative activity of the lymphoid cells. Flow cytometric immunophenotypic analysis of cerebrospinal fluid indicated 97. 98 percent of cells expressed surface CD3, CD7, CD56, CD2, CD5, and partially expressed CD8. This was a rare immunophenotype for NK/T-cell. Cranial MRI with gadolinium showed thickening of the trigeminal nerve with slight enhancement and diffuse leptomeningeal enhancement. CT of the chest and abdomen and bone marrow biopsies were negative. He was diagnosed as primary NK/T cell meningeal lymphoma based on the clinical features and related examination. Conclusions Primary NK/T cell meningeal lymphoma is a rare type of primary central nervous lymphomas which has special immunophenotype. The clinical features include progressive raised intra-cranial pressure, multiple cranial and spinal nerve involvements. Cerebrospinal fluid cytological analysis and flow cytometric immunophenotypic analysis are key work-up for diagnosis. It has poor response to chemotherapy and radiotherapy.

Objective To explore the cost-effectiveness and clinical effect of three platinum based chemotherapy regiments for advanced non small cell lung cancer (NSCLC).Methods 100 patients who were diagnosed as NSCLC,were randomly divided into four groups.The group Ⅰ received NP which was given NVB and DDP.The group Ⅱreceived GP which was given GEM and DDP.The group Ⅲ received TP which was given taxotere and DDP.The clinical effect,adverse reaction and cost effectiveness of the three groups were assessed.Results The clinical effective rates of the three groups were 31.43%,36.36%,37.50% from Ⅰ to Ⅲ group.The adverse events of the group Ⅰ and group Ⅱ were more than those of the group Ⅲ.In the adverse effects of treatment,the major cytotoxicity was digestive reaction and leukopenia in the two groups,but they were tolerable.The ratios of cost effectiveness in the four groups were 550.22yuan,556.48yuan,583.23yuan from Ⅰ to Ⅲ group.Conclusion The NP group is the best one in total cost.