OBJECTIVETo investigate the effects of arsenic trioxide (As(2)O(3)) on the apoptosis and p-glycoprotein (P-gp) expression of multidrug-resistant human leukemia cells.

METHODSHuman multidrug-resistant leukemia cell line K562/ADM overexpressing the MDR1 gene, was used as the target cells. The cell proliferating activity was assessed using the MTT colorimetric assay. Cytomorphology was investigated under light, confocal and electron microscopes. DNA fragmentation was examined using agarose gel electrophoresis, while p-gp expression, cell cycle status and sub-G1 cells were determined using flow cytometry.

RESULTSZero point five to 20 micromol/L As(2)O(3) inhibited the proliferation of K562/ADM cells, and K562/ADM cells were more sensitive to As(2)O(3) than the parental K562 cells. As(2)O(3)-induced apoptosis of K562/ADM cells was determined by the observance of typical morphological changes and the appearance of DNA ladder and sub-G1 cell populations. As(2)O(3) significantly inhibited the P-gp expression of K562/ADM cells, and synergistically enhanced the sensitivity of the drug-resistant cells to adriamycin.

CONCLUSIONSAs(2)O(3) induces growth-inhibition and apoptosis, down-regulates P-gp expression and exerts a synergistic effect in combination with adriamycin in multidrug-resistant leukemia cells.

ATP-Binding Cassette, Sub-Family B, Member 1 ; analysis ; Apoptosis ; drug effects ; Arsenicals ; pharmacology ; Drug Resistance, Multiple ; Gene Expression ; Genes, MDR ; Humans ; Leukemia ; genetics ; metabolism ; Oxides ; pharmacology

Objective:To establish and verify a dynamic web-based nomogram for predicting futile recanalization after thrombectomy in acute ischemic stroke.Methods:Three hundred and four acute ischemic stroke patients admitted to the Second Affiliated Hospital of Soochow University from May 2017 to April 2021 were retrospectively enrolled. All these patients underwent mechanical thrombectomy and obtained successful recanalization. The eligible patients were randomly divided into training group ( n=216) and test group ( n=88) by 7∶3. The nomogram was established and internally validated with the data of the training group, and externally validated with the data of the test group. For the training group, multivariate Logistic regression analysis was performed by including all variables with P<0.05 in univariate analysis, and the independent predictors of futile recanalization were screened out to construct a nomogram. In the training group and the test group, the performance of the nomogram was verified by C-index, calibration chart and decision curve analysis respectively. Results:No significant difference was detected between the training group and the test group in futile recanalization [134/216 (62.0%) vs 56/88 (63.6%), χ 2=0.07, P=0.794]. Multivariate Logistic regression analysis showed that age ( OR=1.04,95% CI 1.00-1.08, P=0.033), National Institutes of Health Stroke Scale (NIHSS) score on admission ( OR=1.11,95% CI 1.04-1.19, P=0.001), neutrophil to lymphocyte ratio ( OR=1.19,95% CI 1.07-1.32, P=0.001), glycated hemoglobins ( OR=2.02,95% CI 1.34-3.05, P<0.001), poor collateral status ( OR=10.87,95% CI 4.08-29.01, P<0.001), postoperative high density ( OR=11.38,95% CI 4.56-28.40, P<0.001) were independent risk factors for futile recanalization. The C-index of this nomogram in the training group and the test group was 0.92 (95% CI 0.877-0.954, P<0.001) and 0.93 (95% CI 0.87-0.98, P<0.001), respectively. Conclusion:This web-based nomogram, including age, NIHSS score on admission, neutrophil to lymphocyte ratio, glycated hemoglobin, poor collateral status and postoperative high density, predicted individual probability of futile recanalization after mechanical thrombectomy with good discrimination and clinical utility.