BACKGROUND:Mechanical stimulation triggers a muscle tissue remodeling, during which, myoblast process is a multi-stage development process. Many signals in extracellular matrix are involved in myoblast process, and mechanical signals are considered as important external factors for muscle formation and regeneration.
Numerous studies concerning cyclic tensile stress effects on myoblast proliferation and apoptosis have been reported, but the specific mechanism underlying the mechanical stimulation in muscle formation is stil unclear. OBJECTIVE:To study the effects of cyclic stretch on proliferation of C2C12 myoblasts and its mechanism.
METHODS:C2C12 myoblasts were cultured in vitro under 10%cyclic stretch for 6, 12 and 24 hours.
RESULTS AND CONCLUSION:The results of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay showed that with the time of cyclic stretch, the proliferation of C2C12 myoblasts and the rate of S-phase fraction were gradual y increased and peaked at 12 hours (P<0.05), and then decreased. Western blot assay showed that the expression of nuclear transcription factorκB protein was decreased with time, which was inversely correlated to the proliferation of C2C12 myoblasts, but increased at 24 hours under the cyclic stretch. These findings indicate that the cyclic stretch can induce C2C12 myoblasts proliferation and alter the cellcycle. Nuclear transcription factorκB may be involved in this process.

Objective To study effects of 1 800 MHz electromagnetic field exposure in pregnancy on the ultrastructure of the hippocampus of offspring rats. Methods Ninety Wistar rats(female and male was 2:1) were mated,and the pregnant rats were exposed to 1 800 MHz microwave field with power density of 0.5 mW/cm2 or 1.0 mW /cm2,12 h/d,for 21 consecutive days,the rats in the control group received dummy exposure. Three rats aged 3 days and 72 days were selected from groups for ultrastructure observation of hippocampus. Results No significant pathological changes were observed in nerve cells and capillary vessels in the hippocampus. Conclusion The results of the present paper indicate that pregnancy exposure to 1 800 MHz electromagnetic field,may not lead to abnormal ultrastructure changes in hippocampus of offspring rats

Leukemia is a kind of cloning disease from malignant hematopoietic stem cells. Its patho-genesis may have relationship with proliferation out of control,dysdiffreentiation and inhibition of apoptosis about leukemia cells. The study confirms that CD44 is expressed in leukemia cells,promoting the occurrence and development of leukemia through participation in cell adhension,proliferation,migration and invasion behavior. In vitro experiment shows that CD44 targeted therapies can effectively kill leukemia cells,and reduce the toxicity to normal tissue cells. Therefore,aiming at the design of the anticancer drugs targeted for CD44 is expected to be used in clinical treatment of leukemia.

Objective To investigate the efficacy of the indocyanine green (ICG) clearance test (ICGR15) combined with the model for end-stage liver disease (MELD) for assessing the short-term prognosis of patients with liver failure.Methods Eighty patients with liver failure were analyzed retrospectively.ICGR15 and relevant clinical data within 24 hours of diagnosis were analyzed.Meanwhile,the MELD score and King's College Hospital (KCH) were evaluated.All findings were tested for correlation with 3-month mortality.Quantitative data were analyzed with analysis of variance and Student's t-test.Count data were analyzed with chi-square test.Correlation analysis was performed with Pearson's coefficient test.Results Among 80 patients with liver failure,39 patients survived and 41 died.The mortality rate of all patients was 51.2％.The serum total bilirubin,creainine concentrations,ICGR15,MELD scores and patient number in accordance with KCH criteria of surviving patients were (288.0±109.1) μmol/L,(63.3±24.4) μmol/L,(48.1±10.2)％,20.6±4.4,and 6 cases,respectively,which were lower than those in dead patients [(340.7 ± 108.2) μmol/L,(98.8 ± 59.1) μmol/L,(60.2 ± 10.6) ％,26.9 ± 7.1 and 19 cases,respectively] (P =0.033,P＝ 0.001,P＝ 0.000,P＝ 0.000 and P =0.003,respectively).There was no significant difference of ICGR15 among four types of liver failure.A positive correlation was observed between ICGR15 and MELD score (r=0.289,P=0.009).The ICGR15-MELD model was created by subjecting ICGR15 and MELD scores to Logistic regression analysis.The following ICGR15-MELD model,Logit (P) =0.105 × ICGR15 + 0.178 × MELD score-9.734,was constructed by Logistic regression analysis.The area under the receiver operating characteristic (ROC) curve was 0.860 and the cut offpoint of 0.3 had sensitivity of 85.40％ and specificity of 74.40％.The area under the curve of the ICGR15-MELD model was significantly higher than those of ICGR15 (0.791),MELD score (0.770) and KCH criteria (0.655).Conclusions ICGR15 and MELD scores perform better than the KCH criteria in predicting the prognosis of liver failure.The ICGR15-MELD model is superior to ICGR15,MELD score,and KCH in predicting the short term prognosis of patients with liver failure.

Objective To isolate enterovirus 71 from a death children,and analyze whether the neurovirulence was related to the variation of nucleotide and amino acid. Methods Enterovirus 71 was isolated from throat swabs which were colleted from Shandong Linyi People's Hospital. The full length genome was sequenced by amplification with RT-PCR and sequencing of 9 overlapped gene fragments covering full length of the genomes. The nucleotide and amino acid sequenced was aligned by BLAST, Bioedit and MEGA 4. Results A strain of enterovirus 71 was isolated and named as SDLY107. The full length was 7405 bp. The results of homology analysis of overall nucleotide sequence showed that strain Fuyang. Anhui. P. R. C/17.08/2 had highest homology (98.6%)with strain SDLY107, and the homology was 80.0% between strain SDLY107 with prototype strain BrCr/70,and 86. 5% between strain SDLY107 with nerve strain MS/87. Phylogenetic analysis showed that the phylogeny was close between SDLY107 with some isolated strains from Chinese Mainland, such as Beijing, Henan, Guangxi, Sbenzhen, Lanzhou, Fuyang, Chongqing and Zhejiang strains, which was clustered for C4 subtype. The results of amino acid sequence analysis showed that there were 2 mutations, E947D and K1873R, for strain SDLY107. Conclusion SDLY107 belonged to C4 subtype, amino acid mutations E947D and K1873R of which may be relevant to the pathogenicity of EV71.

Objective To screen the prevalence of celiac disease with serologic markers in the central Chinese population,specifically in patients with chronic diarrhea-predominant irritable bowel syndrome (D-IBS).Methods A total of 282 adult patients with D-IBS were selected based on ROME Ⅲ criteria with 296 age and sex matched consecutive healthy individuals as controls.A gluten-free diet (GFD) was advised in subjects positive for IgA/IgG anti-htTG/DGP antibodies and the serologic antibodies were retested after the GFD.Results Among the 578 study subjects,five D-IBS patients (5/282,1.77％) and two healthy controls (2/296,0.68％) were positive for anti-htTG/DGP antibodies.Among the seven positive cases,one was lost to follow-up and only four were evaluated during GFD therapy for an average of 5.2 months with clinical and/or serological manifestations improved.Conclusions The prevalence of celiac disease may not be uncommon in China.Compared with the healthy population,patients with D-IBS tend to be affected more.Thus,it is significantly important to conduct routine screening for celiac disease in patients with D-IBS.

Objective To observe the effect of Dai medicine Yapan on TGF-β1/Smads signaling transduction pathway in unilateral ureteral obstruction (UUO) rats,and to explore its possible mechanism in rat renal interstitial fibrosis inhibitory effect.Methods The UUO rat model was established by conducting the unilateral ureteral obstruction(UUO) in 120 male rats.Normal saline gavage or medication were performed for 28 d and serum was collected for detecting BUN and Scr.Then the rats were killed for taking the renal tissue and conducting HE and Masson staining.The expression of TGF-β1,Smad2 and Smad7 in kidney tissues were detected by using the immunohistochemical method.The mRNA expression was detected by RT-PCR;the protein expression was detected by Western blot.Results Various Yapan doses groups could reduce the level of serum BUN and Scr in experimental rats,alleviated renal tubular interstitial inflammatory cells and renal interstitial fibrosis degree,meanwhile up-regulated the expression of TGF-β1,Smad2 mRNA and protein (P＜0.05),while down-regulated the expression of Smad7 mRNA and protein (P＜ 0.05).Conclusion Different concentrations groups of Dai medician Yapan may inhibit Smad2 mRNA expression in some extent,upregulates Smad7 mRNA expression,inhibits the expression of TGF-β1 in kidney tissues through interfering TGF-β1/Smads signaling transduction pathway,thus obtains a therapeutic effect for inhibiting kidney interstitial fibrosis in UUO rat.

Objective To survey the incidence of sleep disorders among patients with industrial injuries and analyze the relevant factors.MethodsA total of 112 depressed patients ( male 106,female 6; aged 22-79 years,course of disease 35 d-25 years) were assessed by a professional psychologist using life satisfaction index A,the type A behavior pattern scale,the Pittsburgh sleep quality index (PSQI) and the Barthel index.ResultsThe incidence of disordered sleep was 40.18％ (45/112),of whom mildly depressed patients were 34.29％,moderately depressed patients 42.86％ and severely depressed patients 85.71％.The incidence of sleep disorders increased with increasing depression severity.The incidence of disordered sleep was significantly higher among the severely depressed patients than among those mildly or moderately depressed,but there was no significant difference in incidence between moderately and mildly depressed patients.PSQI scores among the severely and moderately depressed patients were significantly higher than among those mildly depressed,but there was no statistically significant difference in average PSQI scores between the severely and moderately depressed patients.The sleep disorder group suffered significantly poorer sleep quality and took significantly longer to get to sleep.There were no significant differences in average age,educational level,marital status,social relations,family and social support,gender distribution or course of disease between the two groups.There were,however,significant differences in family income,life satisfaction,character type and disease species between the groups.ConclusionThe incidence of disordered sleep among depressed patients after industrial injury is correlated with the severity of depression,family income,life satisfaction,the type of injury and the patient's character.

Aim To study whether Ophiopogonin D has an effect inhibitory on myocardial hypertrophy induced by AngiotensinⅡand its possible mechanism. Methods Rat myocardial cell line H9 c2 were cultured in vitro. The effect of Ophiopogonin D on cell vitality was tested by;H9 c2 cells were treated with AngⅡ 1μmol ·L-1 after 24h to induce the cardiac hypertrophy,then it was co-treated with different concentrations of Ophio-pogonin D were added for 24h. After above,the total protein content was detected by BCA method;Quantita-tive real-time PCR ( qRT-PCR ) technique was used to examine the expression of marker genes BNP and β-MHC mRNA ,which representing the function of hear-ing; Western blot was used method to detect the ex-pression of autophagy protein LC3 B and high-through-put screening technology was emptoyed to verify it. In addi-tion, the changes of mitochondrial membrane po-tential in H9c2 myocardial cell were also examined. Results The cell viability results showed that H9 c-2 cells exposed to different concentrations of AngⅡ had no significant effect on vitality compared with the con-trol group after 24 h,but high concentrations of Ophio-pogonin D ( 50 ~100μmol · L-1 ) could obviously in-hibit the cell activity. Ot-her experimental results showed that myocardial cells treated with AngⅡ for 24h could cause myocardial hypertrophy,which appar-ently displayed the growth level of specific hypertrophic gene mRNA expression and the marked increase of the total protein expression. As hypertrophy was activated by AngⅡ, cells autophagy would be significantly en-hanced at the same time, more-over, the mitochondrial membrane potential would be reduced. But the effects of Ophiopogonin D could significantly reverse those pathological changes. Conclusion All above experi-mental results indicate that Ophiopogonin D can in-hibitmyocardial hypertrophy induced by AngⅡand pos-sibly plays a critical role in cardiovascular protection.

Objective To compare the degree of cell injury induced by 3D protein (SDLY11 and SDLY107) of enterovirus 71 (EV71) strains.Methods EV71 strains SDLY11 and SDLY107 were respectively isolated from children with mild and severe hand foot mouth disease.The target genes 11-3D-Flag and 107-3D-Flag were amplified by reverse transcription-polymerase chain reation (RT-PCR) and inserted into the eukaryotic expression vector pcDNA3.1.The recombinant plasmids 11-3D-Flag-pcDNA3.1 and 107-3D-Flag-pcDNA3.1 were transformed into Escherichia.coli DH5α, respectively, and were identified by enzyme digestion and sequencing.The recombinant plasmids were transfected into rhabdomyosarcoma (RD) cells, respectively.Expression of 3D protein was detected by indirect immunofluorescence assay and western blot.Cell injury induced by 3D protein was detected with lactate dehydrogenase (LDH) test, cell proliferation was detected by 3-(4,5-dimethylthiazolyl-2)-2,5-diphenylthiazolium bromide (MTT) test, and cell apoptosis was detected with Annexin-V and PI.Multiple comparisons among groups were analyzed using LSD-t test if multiple sets of variables were consistent with homogeneity of variance.If not, Dunnett T3 test was used.Results The 1 400 bp fragments were amplified by reverse tramscription (RT)-polymerase chain reaction (PCR), and the recombinant plasmids were digested by enzyme and the 1 400 bp and 5 400 bp fragments were obtained and identified.Gene sequencing showed that the sequences were consistent with the target genes.The specific fluorescence was observed by indirect immunofluorescence assay, and the western blot showed that the molecular weight of the target protein was 55×103.The LDH test showed that the A490 of SDLY11 3D protein transfection group (0.790±0.048) was higher than that of SDLY107 3D protein transfection group (0.641±0.018).The difference was statistically significant (t=5.14, P<0.05).The cell membrane damage caused by SDLY11 3D protein was more severe than SDLY107 3D protein.The MTT test showed that the A570 of SDLY11 3D protein transfection group (1.028±0.020) was lower than that of SDLY107 3D protein transfection group (1.081±0.002), and the difference was statistically significant (t=3.31, P<0.05).The effect on cell proliferation activity of SDLY11 3D protein was greater than SDLY107 3D protein.The results of Annexin-V/PI showed that the percentage of apoptotic cells of SDLY11 3D protein transfection group and SDLY107 3D protein transfection group were (1.471±0.246)% and (1.465±0.237)%, respectively, and the difference was not statistically significant (t=0.04, P=0.973).Conclusions Compared with the SDLY11 3D protein, SDLY107 3D protein induces slighter cell injury, has weaker effect on cell proliferation activity, and is more favorable for virus replication in cells.