In order to meet the demand of higher medical education reform and to enhance the re-search capability among medical undergraduates , Capital Medical University carried out a project named undergraduate scientific research and innovation program. In the process of the project , several problems were found in both undergraduates and tutors including lack of document indexing skill , professional English ability , doctor-patient communication consciousness , data statistics and paper writing skills of undergraduates and limited time, insufficient funds and lacking experiences of tutors. Through establish-ing sound and standard training system, increasing scientific research funding, setting up incentive mech-anism and increasing scientific research ability training courses, scientific research ability of undergradu-ates and tutors were firmly strengthened.

Objective To explore the contribution of psychoso cial factors including personality and social support to the onset of upper dige stive tract cancer. Methods Ninety-eight patients with up per digestive tract cancer were chosen as disease group, with 98 healthy persons as control group, who matched with disease group in habitation, age, sex and ed ucation level. Both the two groups were studied by Eysenck Personality Questionn aire (EPQ) and social support scale. The differences between the two groups were analyzed. Results The E score of EPQ in disease group was lower than that in control group, but its P and L scores were higher, and the su pport utilization degree in disease group was much lower than that in control gr oup. Positive correlation was found between the E score of EPQ and social suppor t utilization degree in disease group. Conclusion The onset of upper digestive tract cancer is correlated with personality and social suppo rt.

Objective To explore the effects of psychosocial f actors including life events and coping style on the onset of upper digestive tr act cancer. Methods A total of 98 patients with upper diges tive tract cancer were chosen as experiment group, while 98 healthy persons were chosen as control group, who matched with experiment group in habits, age, sex and education background. Both the two groups were studied by Life Event Scale a nd Simplified Coping Style Questionnaire. The difference between the contributio n of psychosocial factors in the two groups was analyzed. Results The stimulating amount and frequency of negative life events in experimen t group were much higher than those in control group, while those of its positiv e life events were much lower. The total score of passive coping style in experi ment group was higher than that in control group, while the total score of posit ive coping style was lower. Conclusion Stress may be one of the etiological factors in causing upper digestive tract cancer, and passive co ping style may also be a risk factor for the etiology of upper digestive tract c ancer.

Objective To explore the effects of different extracts of modified Siwu Siteng Decoction (TFT-Ⅰ, TFT-Ⅱ) on rat models with hyperuricemia. Methods Rat model with hyperuricemia was induced by hypoxanthine and oxonic acid potassium salt. Seventy rats were randomly divided into 7 groups:normal group, model group, allopurinol group, TFT-Ⅰ high and low dose groups, TFT-Ⅱhigh and low dose groups. Each dose group was given lavage with related medicine, and blank group and model group were given lavage with distilled water for one week, respectively. Uric acid in serum (SUA) was measured through fully automatic biochemical analyzer, and xanthine oxidase (XOD) activity in serum and liver tissue was measured through colorimetric method. Results Compared with model group, TFT-Ⅰ and TFT-Ⅱ high dose groups significantly reduced the level of SUA, serum and liver XOD activity (P<0.05), with significant statistical difference between the two groups (P<0.05). TFT-Ⅰ and TFT-Ⅱ low dose groups had no significant effects on SUA, and XOD activity in serum and liver (P>0.05). Conclusion Alcohol soluble ingredients of astragalus membranaceus and Siwu decoction in modified Siwu Siteng Decoction can effectively reduce the level of blood uric acid.

Objective To investigate the role of interleukin-4 (IL-4) and interleukin-5 (IL-5) in the pathogenesis of steroid-resistant (SR) asthma.Methods Fifteen patients with SR asthma and 15 patients with steroid-sensitive (SS) asthma were selected based on their clinical responses to prednisone therapy. The peripheral blood mononuclear cells (PBMCs) were obtained and incubated with phytohemagglutinin (PHA) in vitro for 48 h in the presence or absence of dexamethasone (10-7 mol/L). Expressions of IL-4 and IL-5 mRNA in PBMCs were determined by reverse transcription-polymerase chain reaction (RT-PCR), and mRNA positive PBMCs for IL-4 and IL-5 were measured with in situ hybridization using digoxin-labeled cDNA probes.Results In the absence of dexamethasone, there was no significant difference in the expressions of IL-4 and IL-5 mRNA between SR and SS asthmatics, and the numbers of mRNA positive cells for IL-4 and IL-5 were also similar between these two groups, however, in the presence of dexamethasone (10-7 mol/L), expressions of IL-4 mRNA (P<0.01) and IL-5 mRNA (P<0.05) were significantly inhibited in SS asthmatics, but not in SR asthmatics (P>0.05). The numbers of IL-4 and IL-5 mRNA positive cells decreased from 5.50±1.60 to 2.27±0.98 (P<0.01) and from 5.03±1.29 to 1.67±0.70 (P<0.01), respectively in SS asthmatics, but in the patients with SR asthma, there was no significant change in the number of cells expressing mRNA for IL-4 or IL-5.Conclusion The gene expression of IL-4 and IL-5 in SR asthma was not inhibited by dexamethasone at the concentration of 10-7 mol/L. It is suggested that the relative unresponsiveness of T cells to glucocorticoids and persistent production of cytokines may be one of the mechanisms of steroid resistance in asthma.

Escherichia coli (E. coli) FadR regulator plays dual roles in fatty acid metabolism, which not only represses the fatty acid degradation (fad) system, but also activates the unsaturated fatty acid synthesis pathway. Earlier structural and biochemical studies of FadR protein have provided insights into interplay between FadR protein with its DNA target and/or ligand, while the missing knowledge gap (esp. residues with indirect roles in DNA binding) remains unclear. Here we report this case through deep mapping of old E. coli fadR mutants accumulated. Molecular dissection of E. coli K113 strain, a fadR mutant that can grow on decanoic acid (C10) as sole carbon sources unexpectedly revealed a single point mutation of T178G in fadR locus (W60G in FadRk113). We also observed that a single genetically-recessive mutation of W60G in FadR regulatory protein can lead to loss of its DNA-binding activity, and thereby impair all the regulatory roles in fatty acid metabolisms. Structural analyses of FadR protein indicated that the hydrophobic interaction amongst the three amino acids (W60, F74 and W75) is critical for its DNA-binding ability by maintaining the configuration of its neighboring two β-sheets. Further site-directed mutagenesis analyses demonstrated that the FadR mutants (F74G and/or W75G) do not exhibit the detected DNA-binding activity, validating above structural reasoning.
3-Oxoacyl-(Acyl-Carrier-Protein) Synthase ; genetics ; metabolism ; Amino Acid Sequence ; Bacterial Proteins ; chemistry ; genetics ; metabolism ; DNA, Bacterial ; chemistry ; metabolism ; Escherichia coli ; genetics ; metabolism ; Escherichia coli Proteins ; genetics ; metabolism ; Fatty Acid Synthase, Type II ; genetics ; metabolism ; Fatty Acids ; metabolism ; Gene Expression Regulation, Bacterial ; Hydro-Lyases ; genetics ; metabolism ; Hydrophobic and Hydrophilic Interactions ; Lipid Metabolism ; Models, Molecular ; Molecular Sequence Data ; Mutation ; Protein Binding ; Protein Structure, Secondary ; Repressor Proteins ; chemistry ; genetics ; metabolism ; Sequence Alignment ; Sequence Homology, Amino Acid ; Signal Transduction

Objective For patient-specific open-wedge high tibial osteotomy(OWHTO),a novel anatomical fixation plate was designed,and the effects of geometric parameters and material selection on biomechanical fixation were studied.Methods A patient-specific OWHTO anatomical fixation plate was designed and constructed,and the effects of design parameters(thickness,width,and length of the fixation plate)and four different materials(stainless steel,titanium alloy,magnesium alloy,and PEEK)on the biomechanics of the OWHTO fixation system were studied using finite element analysis.The biomechanical differences between the anatomical fixation plate and TomoFix fixation plate were also compared.Results The thickness had a greater effect on the micromotion of the osteotomy space than the length and width of the fixation plate did.Titanium alloy or magnesium alloy fixation plates were more conducive than stainless steel and PEEK materials in obtaining reasonable stability and mechanical transfer simultaneously.Compared with that of the TomoFix plate,the maximum von Mises stress of the anatomical fixation plate was reduced by 13.5%;the maximum von Mises stress of the screws and tibia was increased by 9.8%and 18.4%,respectively;and the micromotion at the maximum osteotomy space cc was increased by 49.3%.Conclusions Anatomical fixation plates have a positive effect on reducing the stress-shielding effect and improving biomechanical properties under the premise of ensuring stability.This study provides a reference for the development of OWHTO anatomical fixation plates.

Objective To investigate the feasibility and primary clinical outcomes of a kind of independent research and development customized 3D printed external fixator in the treatment of tibial fracture.Methods Data of 7 tibial fracture patients who were treated using computer-assisted reduction and 3D printing technique including a new kind of customized external fixator with automatical reduction function from December 2013 to November 2015 were retrospectively analyzed.There were 5 males and 2 females in this cohort.The age of the patients ranged from 25 to 49 years old,with an average age of 38.1 years old.The procedure was as follows.At first,two or three pins were placed separately into the distal and proximal tibia away from fracture site.Then,the CT scanning was performed on the fractured tibia.According to the CT scanning data,the external fixator was designed by computer software and manufactured by the 3D printing technique.The reduction of tibial fracture was achieved automatically after the 3D printed external fixator was connected to the inserted pins.Finally,the accuracy of reduction was assessed by postoperative X-ray image.During the different fracture healing course,the stress environment could be dynamically adjusted by screwing or unscrewing the nuts to fulfill rigid fixation,compression fixation or elastic fixation for the bone healing.Results All the 7 cases had obtained successful reduction by only one time operation with the 3D printed external fixators.The average lateral angulation was 1.42°± 1.13°,and the average anteroposterior angulation was 1.65°± 1.36°,while the average lateral displacement was 1.38± 1.44 mm,and the average anteroposterior displacement was 1.83± 1.30 mm,which were measured from postoperative X-ray image.The individual durations of the operation were 9 min,8 min,9 min,1.5 min,1.4 min,1.4 min and 2.4 min,respectively.All fractures had achieved bony union in 19-25 weeks after operation,with an average time of 21.4±1.6 weeks.All patients were followed up for 6 months when removal of the external fixator,and no refracture occurred.Conclusion The customized 3D printed external fixator has the function of automatical reduction.In addition,it can provide three kinds of fixation modes,which are rigid fixation,compression fixation and elastic fixation.It has the advantages of simple operation,accurate reduction,reasonable fixation,etc.

Objective To explore the influence of cucurbitacin E (CuE) on autophagy in human bladder cancer cell line T24 and further study its impacts on cell proliferation. Methods MTT assay was used to determine the proliferation inhibition capacity of CuE on T24 and western blot to check the impacts of CuE treatment on the expression of classic autophagy markers LC3A/B and p62. LC3 turnover assay and GFP-RFP-LC3 fluorescent assay were performed to determine autophagy flux. Western-blot was used to check the autophagy inhibition ability of 3-MA on CuE treatment and MTT assay and cell counting assay were used to check the influence of CuE-induced autophagy on cell proliferation with/without autophagy inhibition. Results CuE inhibited the proliferation of T24 and the IC50 in 24 h was about 0.75 μmol/L. CuE treatment increased the expression of LC3A/B Ⅱ and LC3A/B Ⅱ/Ⅰ ratio (P < 0.05) , but decreased the expression of p62 (P < 0.05) , indicating the induction of autophagy. Autophagy flux was induced because of positive LC3 turnover assay and the increase of yellow and red dots in GFP-RFP-LC3 fluorescent assay (P < 0.05). CuE-induced autophagy was inhibited by 3-MA (P < 0.05). With autophagy inhibition, CuE's proliferation suppression ability on T24 was attenuated (P <0.05). Conclusion CuE induces autophagy in bladder cancer cell line T24 and the induced autophagy positively contributes to the inhibitation of cell proliferation.

Objective:To evaluate the mechanical performance of customized metal prosthesis with tibia stems of varying lengths for tibial bone defects reconstruction.Methods:Morphologically matched postoperative finite element models of bone defect revision were developed, with three gradients (15 mm, 30 mm, and 45 mm) according to the degree of bone defect and were reconstructed with 3D printed tantalum metal prosthesis using three tibial stem lengths (80 mm, 120 mm, and 150 mm), respectively. Conventional static and dynamic (walking gait) loading was performed to analyze the peak tibial stress distribution and accumulated sliding distance at the prosthetic interface, and to assess the effects of the three tibial stems of different lengths on the stability of the customized tibial defect restorations and the internal tibial stress state.Results:The peak accumulated sliding distance of the dynamically loaded morphologically matched restorations ranged from 17.94 to 21.31 mm with static loading, which were 68% to 84.3% higher than those of 10.26 to 11.69 mm with static loading. The peak tibial stresses in the dynamically loaded model were greater than those in the statically loaded model, with an increase of 28%-49.2%, including 132.94-143.88 MPa in the statically loaded model and 170.41-200.14 MPa in the dynamically loaded model. The overall accumulated sliding distance of the tibia prosthetic model gradually decreased from the tibial osteotomy surface, and the accumulated peak sliding distances ranged from 10.26 to 11.69 mm for static loading, and from 17.94 to 21.31 mm for dynamic loading. The bone tissue stresses in the anterolateral and medial-posterior tibia increased gradually from top to bottom, and the maximum stress value in each section was in the posterior medial tibia (the maximum value was 200.14 MPa). The highest bone tissue stress in the lateral tibia was affected by the tibial stem length, which resulted in a different location, and it was the area most affected by stress shielding (maximum value of 170.65 MPa).Conclusion:For stability assessment of morphologically matched tantalum customized prosthesis, physiological gait dynamic loading studies are more reliable than static loading; the choice of tibial stem length depends on a combination of accumulated peak sliding distances and tibial bone stress distribution factors.