Objective To investigate the antitumor mechanism of sodium arsenite on human gastric carcinoma cell line SGC-7901 in vitro. Methods MTT assay, light microscopy, electron microscopy, flow cytometry, and immunocytochemical staining were used to analyze the effect of sodium arsenite on biologic behavior of SGC-7901 cells. Results Sodium arsenite (2.50 ～ 40.00 ?mol/L) could inhibit the growth of gastric carcinoma cells, it depended on the duxation and concentration, and its 50% inhibitory concentration(IC50) was 8.69 ?mol/L after 72 hours' treatment. SGC-7901 cells were arrested significantly in G2/M phase treated with sodium arsenite for 48 and 72 hours. SGC-7901 cells presented typical morphologic feature of apoptosis and necrosis after exposure to sodium arsenite. Sodium arsenite up-regulated Caspase-3 protein expression in SGC-7901. Conclusion Sodium arsenite could obviously inhibit the proliferation of SGC-7901 cells, induce cell cycle arrest and apoptosis and necrosis of the cells. its mechanism is possibly associated with inhibition of elimination of ROS and the up-regulated expression of Caspase-3 protein.

Objective To explore the effects of biomimetic electrical stimulation on inducing differentiation of rat bone marrow mesenchymal stem cells(MSCs) into cardiomyocyte-like cells in isolated myocardium.Methods MSCs and cardiac myocytes from SD rats were isolated and cultured by modified method.MSCs were then co-cultured with cardiac myocytes(MSCs/ cardiomyocyte co-culture system).The co-culture system was divided into stimulated group and non-stimulated group.MSCs cells in stimulated group were given supra-threshold square biphasic pulses stimulation(5ms duration,0.5Hz,10V) lasting for 2h each day,while in non-stimulated group were routinely cultured.Each group was divided into three subgroups according to the incubation time of 3,5 and 7 days.The characteristic morphology of MSCs in every subgroup was observed under light microscope.The expression of cTnT in MSCs was detected by immunofluorescence.The rate of cTnT positive expression was also compared between two groups.Results The growth and frequency of myocardial wave of MSCs cells in stimulated group were better or higher than those in non-stimulated group.No expression of cTnT was detected in non-stimulated group at the 5th day of the experiment,while a few MSCs cells in the stimulated group expressed cTnT at the same time point.The cTnT expression was detected in the MSCs cells in the both groups on the 7th day.The rate of cTnT positive expression in stimulated group(20.98%?5.55%) was significantly higher than that in non-stimulated group(13.20%?3.98%,P

Objective To study the correlation between lactate/albumin ratio level and incidence of multiple organ dysfunction syndrome (MODS) as well as mortality in patients with severe sepsis or septic shock.Methods In January 2012-September 2013, 54 patients who were admitted to the intensive care unit(ICU) of a hospital developed severe sepsis and septic shock on the first day of admission, clinical data of patients were analyzed.Results On the first and second days of admission, 30(55.56%)and 26(53.06%)patients developed MODS;lactate/albumin ratio between MODS group and non-MODS group on the first and second days of admission were both significantly different (both P<0.05).Multivariate logistic regression analysis showed that lactate/albumin ratio, oxygenation index (PaO2/FiO2), as well as acute physiology and chronic health evaluation (APACHE Ⅱ) were independent risk factors for predicting MODS in patients with severe sepsis.Lactate/albumin ratios between MODS group and non-MODS group, death group and non-death group were both significantly different (both P<0.05);lactate/albumin ratio was correlated with APACHE Ⅱand PaO2/FiO2, the higher the APACHE Ⅱ score and the lower the PaO2/FiO2, the higher of lactate/albumin ratio.The area under the receiver operating curve (ROC curve) analysis showed that incidence and mortality of MODS on the first day of admission predicted by lactate /albumin ratio were 0.85 and 0.84 respectively;sensitivity, specificity, positive predictive value, and negative predictive value of occurrence of MODS predicted by lactate /albumin ratio>1.735 were 80.00%, 79.17%, 82.67%, and 75.92% respectively, sensitivity, specificity, positive predictive value, and negative predictive value of mortality were 100.00%, 51.02%, 17.23%, and 100.00% respectively.Conclusion Lactate/albumin ratio level is closely correlated with incidence and mortality of MODS in patients with severe sepsis or septic shock.

Objective To determine immune modulatory activity of activated hepatic stellate cells( HSCs) in hepatocellular carcinoma and immune response in tumor microenvironment. Methods Cell proliferation was measured by BrdU incorporation with a microtiter plate reader at 450 nm. The effect of HSCs on T cell proliferation was measured by MLR. Mouse hepatic cancer cell line H22 were implanted on the backs of BALB/c mice to establish the subcutaneous transplanted tumor model. Then the mice were sacrificed after 20 days for anatomical and size determination. Furthermore, Paraffin-embedded tissue was removed by serial tissue sectioning and immunohistochemically examined for expression of T lymphocyte subsets. T lymphocyte subsets in splenocytes were detected by FCM. Apoptotic mononuclear cells were evaluated by FITC-labeled Tunel assay. Results We determined that HSCsCM promoted hepatocellular carcinoma(HCC) cell line proliferation and HSCs inhibit T cell proliferation by MLR in vitro. We also examined normal immune mice to assess the immunosuppression of HSCs in the development of HCC. In the co-transplantation with HSCs group, T cells and their subtypes decreased obviously in the tumors and the spleen. The results showed that co-transplanted HSCs can induce more PD-L1 expression and more mononuclear cell apoptosis in tumor tissue. Conclusion Our results demonstrated that HSCs promote HCC progression partially because of their immune regulatory activity. Our data supply new information to support an integral role for HSCs in promoting HCC progression and suggest that HSCs may serve as a therapeutic target for HCC.

Objective Accumulating reports have suggested that hepatic stellate cells (HSCs) exhibit immunosuppressive ability and may be responsible for the occurrence and development of hepatocellular carcinoma (HCC).The mechanisms through which HSCs affect T-cell-induced adaptive immune responses and the relationship with the regulatory T cells (Treg cells) were studied.Methods We isolated HSCs from wildtype mice to demonstrate the influence of HSCs on T-cell proliferation and explored their effect on Treg cells through mixed leukocyte reactions (MLRs) in vitro.Results We found that activated HSCs could induce T-cell hyporesponsiveness in adaptive immune response by inhibiting the proliferation of T cells andincreasing the quantity of Treg cells.Conclusion Activated HSCs may lead to hypoergia of T cells in adaptive immune reaction and up-regulate the expression of Treg cells,thus facilitating immunotolarance.

Objective To investigate the effect of different gene expression levels of Syntenin on invasion and mi?gration of glioma cells and the underlying molecular mechanisms. Methods Lentiviral RNA interference was used to knockdown the expression of syntenin in U-87 cells. Real-time quantitative PCR was used to detect mRNA expression levels of syntenin . Transwell assay and adhesion assay were used to examine the invasion, migration and adhesion, re?spectively. Western-blot was used to detect the protein expression levels of Syntenin, AKT, p-AKT, and MMP-9. Re?sults The mRNA expression level of Syntenin was greatly reduced in interference group compared with empty vector group (P<0.01). The ability of invasion and migration was much lower in interference group than in empty vector group (P<0.01). However, there were no significant differences in invasion and migration between empty vector group and con?trol group. The adhesion ability of glioma U-87 cells was much higher in interference group than in empty vector group (P<0.05). However, when U-87 cells were seeded on 96-wells coated with HUVEC, the adhesion ability was much lower in interference group than in empty vector group(P<0.05). The protein expression levels of Syntenin, p-AKT, and MMP-9 in interference group were markedly decreased compared with empty vector group(P<0.05). There was no signif?icant difference in expression of AKT protein between interference group and empty vector group (P>0.05). Conclusion Syntenin may enhance the invasion and migration ability of glioma though up-regulation of p-AKT, which in turn pro?motes MMP-9 expression in a corresponding signal transduction pathway.

Objective To observe effects of Genistein and 5fluorouracil(5-FU) on human colon carcinoma cell line Colo320.Methods The MTT assay and median-effect principle were used.Results The two drugs were antagonistic at higher concentrations and synergistic at lower concentrations,The sequence and time of drug administration can influence the effects of the two drugs on Colo320.Conclusion The two drugs were cooperated at lower concentrations and antagonistic at higher concentrations.The sequence and time of drug administration were also important for their effects on the cells.

Objective: To investigate a cluster of coronavirus disease 2019(COVID-19)caused by latent infection in Haikou,so as to provide reference for the prevention and control of COVID-19 clusters. Methods: An epidemiological investigation was conducted according to the COVID-19 Prevention and Control Program(Fourth Edition). The course of diagnosis and treatment,clinical characteristics and field investigation data were collected to analyze the transmission chain and the intergeneration between cases. Results : Among 39 people involved,five confirmed cases and two asymptomatic infections were found,with an attack rate of 17.95%. The cases aged from 40 to 65 years and lived in the dormitories near the farm of Dongshan. The first case(named Case 1)closely contacted with a confirmed case of COVID-19 in Chengmai from January 28 to February 10,was isolated on February 13 and developed symptoms on February 16. The other six cases(Case 2 to Case 7)shared the water source with Case 1 from January 28 to February 13(within the incubation period of Case 1). They needed to open the power switch outside Case 1's room and the water valve in Case 1's washroom before the use of water. They might be infected by contacting the doorknob and the water valve contacted by Case 1,or by the aerosol formed after Case 1 used the washroom,then infected each other when living together. The onset of Case 2 to Case 7 was earlier than Case 1,and they had no travelling history in Hubei Province 14 days before and contacted no confirmed cases except Case 1. Therefore,Case 1 was the source of the cluster during his incubation period of COVID-19. Conclusion This was a cluster of COVID-19 due to latent transmission by living in the same area and touching the same objects indirectly,which indicated that COVID-19 was infectious in the incubation period.

Objective: To dynamically evaluate left ventricular perfusion, global and local functional changes during left ventricular aneurysm (LVA) formation and to explore the relationship between the size of LVA and LVEF, LVESV, LVEDV by gated99mTc-MIBI SPECT (GSPECT) and gated18F-FDG PET metabolic (GPET) imaging in experimental pigs. Methods: LVA model was established by occlusion of left circumlfex artery (LCX) and placing an Ameroid constrictor at the proximal end of left anterior descending artery (LAD) in a total of 16 Chinese mini-pigs. At the 1st, 4th and 8th weeks of surgery, the changes of total perfusion defect (TPD), LVA formation and LVEF, LVESV, LVEDV were dynamically evaluated by GSPECT and GPET; the relationships between the size of LVA and LVEF, LVESV, LVEDV were analyzed respectively.Results: There were 5 pigs died in surgery and 2 died at the 1st week of modeling. According to golden (pathological) standard, 9 animals successfully ifnished the dynamic imaging study. At the 1st week of (basic) modeling, 4 animals formed large LVA, 2 formed small LVA at the apex and 3 without LVA formation. At the 4th and 8th weeks of modeling, dynamic imaging presented that the animals with large LVA had gradually increased range and degree of perfusion defect, LVEDV, LVESV, while gradually decreased LVEF; the above indexes were relatively stable in animals with small or none LVA. In addition, the size of LVA was related to LVEF (r=-7.26), LVEDV (r=0.855) and LVESV (r=0.825), allP<0.05. Conclusion: In experimental pigs, at the beginning of LVA formation, large range and severe perfusion defect may cause large aneurysm, the LV functional damage and remodeling may gradually increase and the prognosis is poor; in contrast, the animals with small or none LVA have better prognosis and usually without ventricular remodeling; which implies that in acute phase of LVA formation, the size of aneurysm may predict the trend of global LV systolic function and remodeling at the early stage.

Objective: To assess the feasibility of coronary lfow reserve (CFR) detection by SPECT myocardial perfusion imaging using a self developed software with preliminary clinical veriifcation. Methods: CFR calculation software was developed according to Mat lab guide. A total of 16 patients were enrolled including 13 male and 3 female at the mean age of (58±11) years . CAG conifrmed that 25 coronary branches were with stenosis>50% and 23 branches were without stenosis. 2-day ATP/rest99mTc-sestamibi dynamic SPECT myocardial perfusion imaging was conducted to detect CFR. First transit counts were used to sketch the interested pulmonary artery segments and to obtain the arterial input curve of contrast agent as total PAC reached to heart. Reconstructed short-axis images were divided into 3 sections to sketch interested territories (ROI) and to obtain RMC at each territory. Estimated CFR was expressed by the ratio of MBF=RMC/PAC followed by calculating the ratio of MFR=MBFstress/MBFrest. Results: The difference between simulated value and true value could be ignored which conifrmed that our program may accurately measure CFR. The reproducibility by different operators (r=0.986) and the same operator (r=0.983) was good. CFR value in non-stenosis branches were higher than stenosis branches (1.28 ± 0.19) vs (1.10 ± 0.27),P=0.008 and CFR value in stenosis branches was negatively related to stenosis degree (r=-0.5,P=0.02). Conclusion: Our self developed software is reliable for CFR detection by SPECT myocardial perfusion imaging; preliminary study showed good application prospect in clinical practice.