BACKGROUND:Bone marrow mesenchymal stem cel s can be differentiated into myocardial cel s induced by 5-azacytidine in vitro, which provides an opportunity for cel transplantation in the treatment of heart disease. OBJECTIVE:To study the induction effects of 5-azacytidine at different concentrations on the myocardial differentiation of bone marrow mesenchymal stem cel s in rats. METHODS:Passage 3 bone marrow mesechymal stem cel s were incubated with DMEM containing 0, 5, 10, 20μmol/L 5-azacytidine for 24 hours, and then the induced medium was replaced by DMEM containing 5%fetal bovine serum for subsequent 28-day culture. Afterwards, expression of cardiac troponin I was detected by immunocytochemical method. RESULTS AND CONCLUSION:Cel death occurred at 24 hours after 5-azacytidine induction, which was more obvious in the 20μmol/L group than the 5 and 10μmol/L groups. The positive expression of cardiac troponin I was significantly lower in the 5μmol/L group than the 10 and 20μmol/L groups (P<0.05), but there was no significant difference between the 10 and 20μmol/L groups (P>0.05). These experimental findings indicate that 5-azacytidine can induce the differentiation of rat bone marrow mesenchymal stem cel s into myocardial cel s in vitro, and its optimal concentration is 10μmol/L.

AIM:To put forward three-level design(Box-Behnken design) for fitting response surfaces to optimize the extraction technology of total flavonoids from Hypericum ascyron L.METHODS:Four factors,including temperature,reflux time,concentration of ethanol,ratio of solvent to raw material were used to examine the yield of total flavonoids.Prediction was carried out through comparing the observed and predicted values.RESULTS:The results suggested that ethanol concentration and extraction temperature were two statistically significant factors.The optimum conditions of extraction process consisted of the ratio(mL:g)of solvent to material(13.3:1),ethanol concentration(53.2%),extraction temperature(78.7℃)and extraction time(2.3h).Regression coefficient of bino-mial fitting complex model was as high as 0.984 6.Bias between observed and predicted values was -4.01%.CONCLUSION:Box-Behnken design is success in optimizing the extaction in close agreement with the predicted values of the mathematic model.

Nitric oxide is an important signalling and effector molecule which plays an indispensable role in modulating the function of platelets.Recent research revealed that a L-arginine/nitric oxide pathway presented in human platelets and nitric oxide derived from this pathway was called platelet-derived nitric oxide.The impaired synthesis and release of platelet-derived nitric oxide is closely related to the onset and development of some cardiovascular diseases,such as hypertension,atherosclerosis and diabetes.Recent progress in the relationship between platelet-derived nitric oxide and some cardiovascular diseases is reviewed in this article.Thorough research in PDNO not only has great clinical significance but also contributes to finding new ideas and new target for drug therapy.

AIM:To put forward three-level design(Box-Behnken design)for fitting response surfaces to optimize the extraction technology of total flavonoids from Hypericum ascyron L.METHODS:Four factors,including temperature,reflux time,concentration of ethanol,ratio of solvent to raw material were used to examine the yield of total flavonoids.Prediction was carried out through comparing the observed and predicted values.RESULTS:The results suggested that ethanol concentration and extraction temperature were two statistically significant factors.The optimum conditions of extraction process consisted of the ratio(mL:g)of solvent to material(13.3:1),ethanol concentration(53.2%),extraction temperature(78.7℃)and extraction time(2.3h).Regression coefficient of binomial fitting complex model was as high as 0.984 6.Bias between observed and predicted values was-4.01%.CONCLUSION:Box-Behnken design is success in optimizing the extaction in close agreement with the predicted values of the mathematic model.

BACKGROUNDHeterosexual sex has become the dominant transmission route in China. Recently studies reported high heterogeneity in heterosexual transmission risk in resource-limited countries. The aim of this study was to summarize the risk of HIV transmission among Chinese serodiscordant couples.

METHODSA systematic review and meta-analysis of observational studies of heterosexual HIV transmission among serodiscordant couples in China was conducted. Two reviewers conducted a literature search using the China National Knowledge Infrastructure (CNKI), Chinese Medical Current Contents (CMCC), and Medline databases. Pooled transmission estimates per 100 person-years (PY) were calculated using a random-effects model. Meta-regression analysis and subgroup analysis stratified by study design, transmission direction and period of antiretroviral therapy (ART) availability were conducted to assess the factors associated with transmission.

RESULTSEleven eligible studies were identified reporting on 11 984 couples and 405 HIV transmission events. HIV transmission risk from HIV-positive individuals to heterosexual partners was 1.68 (95%CI 0.74 - 2.62) per 100 PY. Study design did not reach statistical significance in meta-regression analysis. The pooled female-to-male transmission estimate was 1.11 (95%CI 0.09 - 2.14) per 100 PY and male-to-female transmission estimate was 1.43 (95%CI 0.19 - 2.68) per 100 PY. The pooled estimate for those before the availability of the Chinese National Free Antiretroviral Therapy Program (2.13 (95%CI 0.00 - 4.63) per 100 PY) was higher than that for those after the implementation of this program (1.44 (95%CI 0.62 - 2.26) per 100 PY).

CONCLUSIONSTransmission estimates in China were lower than other developing countries, but higher than developed countries. Research that better defines HIV secondary transmission rates and the associated behavioral, treatment adherence, and health-related risk factors among heterosexual serodiscordant couples in China is needed.

China ; Female ; HIV Infections ; etiology ; transmission ; Heterosexuality ; Humans ; Male ; Risk

Objective:To detect 11 kinds of illegally added chemicals in anti-fatigue health foods including sildenafil ,tadalafil, vardenafil , acetildenafil , homosildenafil , hydorxyhomosildenafil , norneosildenafil , aminotadalafil , pseudovardenafil , thioaildenafil and noracetildenafil.Methods:An HPLC-MS/MS method was used with LUNA C18(250 mm ×4.6 mm, 5μm)as the analysis column and triethylamine phosphate , acetonitrile and methanol as the mobile phase with gradient elution at the flow rate of 1ml.min-1 .An ESI+scan and an MS/MS mode were applied .The qualitative and quantitative analysis were carried out by HPLC-MS/MS.Results:Through the detection of 100 batches of samples , 85 batches were only found illegally added chemical substance sildenafil mainly at the concentration of 5-15 mg per granule .Conclusion:The method of HPLC-MS/MS can be used as a powerful screening tool for the rapid drug screening in basic level drug control laboratories to reduce chemical substances illegally added in anti -fatigue health foods .

Objective: To analyze the pathogenic surveillance programs and related factors on bacillary dysentery in Beijing, 2008-2017, to provide evidence for the practices of diagnosis, treatment and prevention of the disease. Methods: Analysis was conducted on surveillance data of bacillary dysentery, collected from the surveillance areas of national bacillary dysentery in Beijing. Shigella positive rate of stool samples were used as the gold standard while detection rate of Shigella, diagnostic accordance rate and resistance were computed on data from the surveillance programs. Chi-square test was used to compare the rates and unconditional logistic regression was used to analyze the related factors of Shigella infection. Results: Both the reported incidence rate on bacillary dysentery and detection rate of Shigella in diarrhea patients showed significantly decreasing trend, from 2008 to 2017. The accordance rate of bacillary dysentery was only 7.80% (111/1 423). Shigella sonnei was the most frequently isolated strain (73.95%, 159/215) followed by Shigella flexnery. Results from the multivariate logistic regression of Shigella positive rate revealed that among those patients who were routine test of stool positive vs. routine test of stool positive (OR=1.863, 95%CI: 1.402-2.475), onset from July to October vs. other months'time (OR=7.271, 95%CI: 4.514-11.709) temperature ≥38 ℃vs. temperature <38 ℃(OR=4.516, 95%CI: 3.369-6.053) and age from 6 to 59 years old vs. other ages (OR=1.617, 95%CI: 1.085-2.410), presenting higher positive detection rates of Shigella from the stool tests. The resistant rates on ampicillin and nalidixic acid were 97.57% (201/206) and 94.90% (186/196), both higher than on other antibiotics. The resistant rates on ciprofloxacin (16.33%, 32/196), ofloxacin (9.57%, 11/115) and on amoxilin (15.05%, 31/206) were relatively low. The resistant rate appeared higher on Shigella flexnery than on Shigella sonnei. The proportion of strains with resistance on 3 more drugs, was 30.00%(21/70). Conclusions: The diagnostic accordance rate of bacillary dysentery in Beijing was low, with severe resistance of Shigella. Our findings suggested that clinicians should take multiple factors into account in their practices about epidemiological history, clinical symptom and testing results for diarrhea patients.
Adolescent ; Adult ; Anti-Bacterial Agents/therapeutic use* ; Beijing/epidemiology* ; Child ; China/epidemiology* ; Dysentery, Bacillary/prevention & control* ; Feces/microbiology* ; Humans ; Middle Aged ; Population Surveillance/methods* ; Sentinel Surveillance ; Shigella/isolation & purification* ; Shigella flexneri/isolation & purification* ; Shigella sonnei/isolation & purification* ; Young Adult