Study on early warning threshold values for 7 common communicable diseases in Gansu province, 2016 / 中华流行病学杂志

Objective: To optimize the warning threshold values of common communicable diseases in Gansu province, and improve the early warning effect. Method: An early warning model was set up for influenza, scarlet fever, other infectious diarrheal diseases, dysentery, typhoid and paratyphoid, viral hepatitis type E and hand foot and mouth disease (HFMD) respectively in Gansu by using the moving percentile method and cumulative sum method. By calculating the sensitivity, specificity, predictive value of positive test, predictive value of negative test, Youden' index and receiver-operating characteristic curve, the optimum early warning threshold values for communicable diseases in Gansu were selected. Results: The optimum early warning boundary values of influenza, scarlet fever, other infectious diarrheal diseases, dysentery, typhoid and paratyphoid, and viral hepatitis type E were P(90), P(80), P(95), P(90), P(80) and P(90) respectively. The optimum early warning parameters of HFMD were k=1.2, H=5σ. Under the optimum early warning boundary values/parameters, the early warning sensitivities of influenza, scarlet fever, other infectious diarrheal diseases, dysentery, typhoid and paratyphoid, viral hepatitis type E and HFMD were 86.67%, 100.00%, 91.67%, 100.00%, 100.00%, 100.00% and 100.00%, the specificities were 86.49%, 62.22%, 75.00%, 100.00%, 97.92%, 89.13% and 74.47%. The predictive values of positive test were 72.22%, 29.17%, 52.38%, 100.00%, 80.00%, 54.55% and 29.41%, and the predictive values of negative test were 94.12%, 100.00%, 96.77%, 100.00%, 100.00%, 100.00% and 100.00%, and the Youden' indexes were 0.73, 0.62, 0.67, 1.00, 0.98,0.89 and 0.74. Receiver-operating characteristic curve showed that the values/parameters of this warning boundary were the points closest to the upper left of the coordinate diagram. Conclusion: The early warning thresholds of influenza, other infectious diarrheal diseases, dysentery and hepatitis E in Gansu may be raised appropriately and the early warning parameters of HFMD need to be adjusted to improve the effectiveness of early warning.

Lead time bias and its control in observational studies for clinical outcomes / 中华流行病学杂志

Lead time bias might exist in observational study for clinical outcomes. This paper summarizes the concept of lead time bias, causes and control of lead time bias by using the studies of influences of screening diagnostic test on cancer patients'survival and highly active antiretroviral therapy on HIV/AIDS patients' survival as examples for the purpose of providing thinking and methods in the control of lead time bias for the accurate evaluation of the effects of interventions, such as test and treatment, on the diseases with multi courses or phases.

14,15-Epoxyeicosatrienoic acid induces the proliferation and anti-apoptosis of human carcinoma cell

Epoxyeicosatrienoic acids [EETs], which are cytochrome P450 epoxygenase metabolites of arachidonic acid, have anti-inflammatory effects, modulate smooth muscle proliferation, and inhibit smooth muscle migration. This study was designed to determine whether exogenous EETs have any effect on the cell proliferation and apoptosis of carcinoma cell as well as the possible signaling pathways of EETs in this regulation. The effects of EETs on the proliferation and anti-apoptosis of human carcinoma cells were measured by MTT assay and flowcytometric analysis, and the regulation of PPARy, epithelial growth factor receptor [EGFR], extracellular signal-regulated kinase [ERK], phosphatidylinositol 3 [PI3]-Kinase/AKT pathways was investigated by reverse transcriptase polymerase chain reaction [RT-PCR] and western blot analysis. Results of this study suggested that 14, 15-EET may activate the expression of PPARy in Tea-8113 cells. 14,15-EET may stimulate cell proliferation, and increase the percentage of cells during S-G2-M phase in Tea-8113 cells significantly. The levels of EGFR, ERK, and PI3 kinase/AKT proteins were significantly induced by treatment of 14, 15-EET and 14,15-EET/ AUDA, but no significant changes were observed by addition of GW9662. These findings suggest that exogenous 14,15-EET has potent inhibitory effect on proliferation, and could induce apoptosis in Tea-8113 cell, and these changes are related to the expression of PPARganna, the activation of EGFR, ERK, and PI3 kinase/AKT proteins