Objective:To discuss the effect of circadion rhythm gene TIMELESS(TIM)silencing on immune escape of the ovarian cancer cells,and to clarify its related mechanism.Methods:The CD8+T lymphocytes were isolated and identified by flow cytometry to detect the proportion of CD3+/CD8+cell subsets.The human ovarian cancer SK-OV-3 cells were cultured in vitro and divided into interference plasmid transfected with TIM small interfering(siRNA)(si-TIM),negative control plasmid(si-NC),programmed death ligand 1(PD-L1)over-expression plasmid(oe-PD-L1),and negative control plasmid(oe-NC)groups.The cells were further divided into blank control group(BC group,non-transfection),si-NC group(transfected with si-NC),si-TIM group(transfected with si-TIM),si-NC+oe-NC group(transfected with si-NC and oe-NC),and si-TIM+oe-PD-L1 group(transfected with si-TIM and oe-PD-L1).Real-time fluorescence quantitative PCR(RT-qPCR)and Western blotting methods were used to detect the expression levels of TIM mRNA and protein in the SK-OV-3 cells to verify TIM gene silencing.The transfected SK-OV-3 cells were co-cultured with activated CD8+T lymphocytes and divided into BC group(SK-OV-3 cells cultured alone),BC/T group,si-NC/T group,si-TIM/T group,si-NC+oe-NC/T group,and si-TIM+oe-PD-L1/T group.CCK-8 method was used to detect the survival rates of the SK-OV-3 cells in various groups;flow cytometry was used to detect the apoptotic rates of the SK-OV-3 cells and positive expression rate of PD-L1 on surface of the cells in various groups;enzyme-linked immunosorbent assay(ELISA)method was used to detect the levels of interferon-γ(IFN-γ)and tumor necrosis factor-α(TNF-α)in the co-culture supernatant;lactate dehydrogenase(LDH)release assay was used to detect the cytotoxicity of the CD8+T lymphocytes in various groups;RT-qPCR method was used to detect the expression levels of TIM and PD-L1 mRNA in the SK-OV-3 cells in various groups;Western blotting method was used to detect the expression levels of TIM and PD-L1 proteins in the SK-OV-3 cells in various groups.Results:After scparated with immune magnetic bead method,the proportion of CD8+T lymphocyte(CD3+/CD8+)subsets was(96.56%±0.59%),indicating high purity of the extracted CD8+T lymphocytes.Compared with BC group,the expression levels of TIM mRNA and protein in the cells in si-TIM group were significantly decreased(P<0.01),suggesting successful TIM gene silencing in the ovarian cancer SK-OV-3 cells.The CCK-8 results showed that compared with BC group,the survival rate of the SK-OV-3 cells in BC/T group was significantly decreased(P<0.01);compared with BC/T group,the survival rate of the SK-OV-3 cells in si-TIM/T group was significantly decreased(P<0.01).The flow cytometry results showed that compared with BC group,the apoptotic rate of the SK-OV-3 cells in BC/T group was significantly increased(P<0.01);compared with BC/T group,the apoptotic rate of the SK-OV-3 cells in si-TIM/T group was significantly increased(P<0.01);compared with si-TIM/T group,the apoptotic rate of the SK-OV-3 cells in si-TIM+oe-PD-L1/T group was significantly decreased(P<0.01).Compared with BC group,the positive expression rate of PD-L1 on surface of the SK-OV-3 cells in si-TIM group was significantly decreased(P<0.01).The ELISA results showed that compared with BC/T group,the levels of IFN-γ and TNF-α in the culture supernatant in si-TIM/T group were significantly increased(P<0.01);compared with si-TIM/T group,the levels of IFN-γ and TNF-α in the supernatant in si-TIM+oe-PD-L1/T group were significantly decreased(P<0.01).The LDH release assay results showed that compared with BC/T group,the cytotoxicity of the CD8+T lymphocytes in si-TIM/T group was significantly increased(P<0.01);compared with si-TIM/T group,the cytotoxicity of the CD8+T lymphocytes in si-TIM+oe-PD-L1/T group was significantly weakened(P<0.01).The RT-qPCR and Western blotting results showed that compared with BC group,the expression levels of PD-L1 mRNA and protein in the SK-OV-3 cells in si-TIM group were significantly decreased(P<0.01);compared with si-TIM group,the expression level of PD-L1 protein in the cells in si-TIM+oe-PD-L1 group was significantly increased(P<0.01).Conclusion:TIM gene silencing enhances the cytotoxic effect of CD8+T lymphocytes on ovarian cancer SK-OV-3 cells and inhibits immune escape,and its mechanism may be related to the regulation of PD-L1 protein expression.

Objective:To investigate the effects and mechanisms of allogeneic epidermal stem cells (ESCs) on the survival of allogeneic full-thickness skin grafts in nude mice with full-thickness skin defect wounds.Methods:Experimental research methods were applied. Primary ESCs that appeared paving stone-like after being cultured for 7 d were obtained by enzymatic digestion method from one 4-week-old male BALB/c-NU nude mouse (the same strain, age, and sex below). The cells of third passage were identified by flow cytometry to positively express ESC marker CD44 and negatively express CD45, meanwhile, the positive expression of ESC markers of p63 and integrin 6α, and negative expression of CD71 were identified by immunofluorescence method. The ESCs of third passage in the logarithmic growth phase were used for the following experiments. Twenty-six nude mice were equally divided into phosphate buffered saline (PBS) group and ESCs group according to the random number table. A full-thickness skin defect wound was made on the back of each nude mouse, and then the wounds of the two groups were sprayed with equal volumes of PBS and ESCs, respectively. The wounds were transplanted with full-thickness skin grafts cut from the backs of 4 other nude mice. Each ten nude mice from the two groups were selected, the wound healing and skin survival on post surgery day (PSD) 0 (immediately), 3, 7, 14, and 21 were observed, and the survival ratio and shrinkage rate of skin grafts on PSD 3, 7, 14, and 21 were calculated (the number of sample was the number of surviving skin grafts at each time point); the blood perfusion in the skin grafts on PSD 3, 7, and 14 was detected by the laser speckle blood flow imager, and the blood flow ratio of nude mice skin grafts in ESCs group to PBS group at each time point was calculated (the number of sample was the pair number of surviving skin grafts in group pairing at each time point). The skin graft tissue of each 3 nude mice remained in the two groups were collected on PSD 7, and the mRNA expressions and protein expressions of tumor necrosis factor α (TNF-α), interleukin 8 (IL-8), IL-10, type Ⅰ collagen, type Ⅲ collagen, and matrix metalloproteinase 9 (MMP-9) in the tissue were detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction and Western blotting, respectively. Data were statistically analyzed with Log-rank test, analysis of variance for repeated measurement, one-way analysis of variance, independent sample t test, and Bonferroni correction. Results:Taking the condition on PSD 0 as a reference, the wounds of nude mice in the two groups healed gradually on PSD 3, 7, 14, and 21, and the shrinkage of skin grafts was gradually obvious. Among them, the shrinkage healing of wound of nude mice in PBS group was more significant than that in ESCs group. On PSD 3, the skin graft of 1 nude mouse failed in ESCs group, while the skin graft of 3 nude mice failed in PBS group. On PSD 7, the skin graft of another nude mouse failed in PBS group. The survival ratio of skin grafts of nude mice in the two groups was similar on PSD 3, 7, 14, and 21 ( P>0.05). On PSD 3, 7, 14, and 21, the shrinkage rates of skin grafts of nude mice in ESCs group were (9.2±0.4)%, (19.7±1.2)%, (53.6±3.5)%, and (62.2±5.1)%, respectively, which was significantly lower than (11.0±0.9)%, (47.8±2.8)%, (86.1±7.1)%, and (89.7±9.0)% in PBS group ( t=5.719, 26.650, 11.940, 7.617, P<0.01). On PSD 3, 7, and 14, blood perfusion signals were observed in the skin grafts of nude mice in the two groups. The average blood perfusion ratios of the skin grafts of nude mice in ESCs group to PBS group were greater than 1, and there was no statistically significant difference in the overall comparison of 3 time points ( P>0.05). On PSD 7, compared with those of PBS group, the mRNA and protein expressions of TNF-α, IL-8, type Ⅰ collagen, and type Ⅲ collagen in the skin graft tissue of nude mice in ESCs group were significantly reduced, while the mRNA and protein expressions of IL-10 and MMP-9 in the skin graft tissue of nude mice in ESCs group were significantly increased (in mRNA comparison, t=2.823, 2.934, 2.845, 2.860, 3.877, 2.916, P<0.05). Conclusions:Allogeneic ESCs can reduce the shrinkage of allogeneic full-thickness skin grafts transplanted on full-thickness skin defect wounds in nude mice, promote the formation of new blood vessels between the skin graft and the wound, reduce inflammation and collagen protein expression, and promote the expression of MMP-9, thus improving the survival quality of skin grafts.

Epidemiology is one of main courses for undergraduate students majoring in preventive medicine.There are some limitations in the traditional epidemiology teaching,which is usually characterized in indoctrinated education:"lectured by the teachers and listened by the students." In Zhejiang University,staff of the epidemiology division tried to explore a new teaching mode as ‘student-centered,teacher-leading,question-based,and combining with literature discussion and course practice.'After practicing for two years,students were inspired in learning initiatives,with teaching effectiveness obviously improved.

Objective To investigate the predictive value of plasma gelsolin in the prognosis of patients with ST-sgement elevation myocardial infarction ( STEMI ) and undergone primary percutaneous coronary intervention ( PCI ) .Methods The study included 206 patients with STEMI and undergone primary PCI, 148 patients with stable angina pectoris and received elective PCI and 80 healthy volunteer as the health population (NP) control.Blood samples were taken at admission on day 1, 3, 5, 7 and 9 to determine the plasma gelsolin level .Patients′baseline clinical characteristics , blood biochemistry tests results , details of operation and their cardiovascular risk factors were recorded .Major adverse cardiovascular events (MACE) within one year were recorded.Results (1) Compared to the stable angina group and the NP group, the level of plasma gelsolin of STEMI patients were obviously decreased at various time points ( all P<0.05 ) .There were no statistical differences between the stable angina group and the NP group .( 2 ) Patients with STEMI were catagorized into MACE group (n=78) and non-MACE group (n=128) according their follow up record in 1 year.The level of plasma gelsolin in patients with MACE were lower than the non-MACE group ( P <0.05 ) with the minimum value detected on day 7.Among patients complicated with MACE (n=78), they were further devided into the deceased group (n=18) and the survival group (n=60).Plasma gelsolin levels were lower in the deceased group with satistical differences found on day 5, 7 and 9.(3) Single factor Logistic regression analysis showed that the level of plasma gelsolin on day 7 was independent risk factor of MACE within one year ( P =0.014 ) .( 4 ) Setting the cutoff value of plasma gelsolin on day 7 as 21.7 mg/L,the sensitivity and speciticity for the MACE in STEMI patients treated with primary PCI within one year were 82.1%and 81.4%respectively , with the area under the receiver operator characteristic curve ( ROC ) was 0.854 ( 95% confidence interval 0.732 -0.961 , P <0.01 ) . Conclusions Plasma gelsolin levels are correlated with the severity of STEMI lesions and plasma gelsolin can be used as predicting factor of prognosis .