Robust Variable Selection and Estimation Based on Kernel Modal Regression.

Model-free variable selection has attracted increasing interest recently due to its flexibility in algorithmic design and outstanding performance in real-world applications. However, most of the existing statistical methods are formulated under the mean square error (MSE) criterion, and susceptible to non-Gaussian noise and outliers. As the MSE criterion requires the data to satisfy Gaussian noise condition, it potentially hampers the effectiveness of model-free methods in complex circumstances. To circumvent this issue, we present a new model-free variable selection algorithm by integrating kernel modal regression and gradient-based variable identification together. The derived modal regression estimator is related closely to information theoretic learning under the maximum correntropy criterion, and assures algorithmic robustness to complex noise by replacing learning of the conditional mean with the conditional mode. The gradient information of estimator offers a model-free metric to screen the key variables. In theory, we investigate the theoretical foundations of our new model on generalization-bound and variable selection consistency. In applications, the effectiveness of the proposed method is verified by data experiments.

APOBEC3 deletion polymorphism is associated with epithelial ovarian cancer risk among Chinese women.

Ovarian cancer remains the leading cause of death from gynecological malignancies and the second most common gynecological malignancy among women worldwide. However, the etiology still remains largely unknown. Previous studies identified APOBEC3 gene deletions were significantly associated with higher breast cancer risk in both European and Chinese women. Considering both breast and ovarian cancers being hormonally driven and sharing multiple risk factors, we performed this case-control study to evaluate the association between APOBEC3 deletion and epithelial ovarian cancer (EOC) risk. We analyzed the APOBEC3 deletion in a case-control study of 2,938 Chinese women (including 1,374 EOC cases and 1,564 healthy controls). All participants were genotyped using real-time qualitative PCR (qPCR). APOBEC3 deletion was significant associated with EOC risk, with ORs (95 % CIs) of 1.46 (1.14-1.86) associated with one copy deletion and 2.53 (0.91-7.06) associated with two copy deletion compared with subjects with no deletion (P for trend =1.50 × 10(-3)). Additional adjustments and stratified analyses did not change the results materially. Our data suggests that the loss genotypes of APOBEC3 deletion predispose their carriers to EOC.

Assessment of transvaginal hysterotomy combined with medication for cesarean scar ectopic pregnancy.

The objective of this retrospective study was to explore a novel surgical technique, transvaginal hysterotomy combined with methotrexate injection, for treatment of cesarean scar ectopic pregnancy in 12 patients. All patients underwent the operation. Mean (SD; 95% CI) operative time was 21.6 (7.3; 17.0-26.2) minutes, and intraoperative blood loss was 90.8 (59.6; 52.9-128.7) mL. Postoperative ultrasonography confirmed removal of the pregnancy sac. The length of hospital stay was 7.4 (3.7; 5.0-9.8) days. The first normal postoperative menstrual period was at 28.3 (5.6; 24.7-31.9) days after surgery. The serum ß-human chorionic gonadotropin concentration returned to normal at 15.8 (6.3; 11.8-19.8) days. We conclude that surgical removal of the ectopic sac via transvaginal hysterotomy combined with methotrexate injection during the operation is a potentially good new approach to treatment of cesarean scar ectopic pregnancy. The efficacy and safety of the technique need further confirmation in future studies.

Proportional changes of CD4+CD25+Foxp3+ regulatory T cells in maternal peripheral blood during pregnancy and labor at term and preterm.

PURPOSE: To evaluate the proportional changes of CD4+CD25+Foxp3+ regulatory T cells (Tregs) in maternal peripheral blood during pregnancy and labor at term and preterm. METHODS: Peripheral blood was collected from 20 non-pregnant controls and 139 pregnant women (60 at different gestational ages, 48 at term with or without labor, and 31 in threatened or actual preterm labor). CD4+CD25+Foxp3+ Tregs in peripheral blood samples were analyzed in peripheral blood samples by flow cytometry. Placentas from preterm women were examined for the presence of histological chorioamnionitis (HC). RESULTS: The percentage of circulating CD4+CD25+Foxp3+ Tregs was significantly increased in women during the first trimester compared with non-pregnant controls (P < 0.0001), peaking during the second trimester and then declining slightly in the third trimester. There was a significantly lower level of CD4+CD25+Foxp3+ Tregs in women with term labor than in those at term without labor (P < 0.0001). Women admitted in preterm labor had a lower proportion of CD4+CD25+Foxp3+ cells than those admitted with threatening preterm labor (P < 0.0001). Preterm women with evidence of HC had decreased proportion of CD4+CD25+Foxp3+ cells than those without HC in preterm deliveries (P=0.008). Moreover, the percentages of CD4+CD25+Foxp3+ cells in preterm subjects, irrespective of the HC status, were significantly diminished compared with women with normal pregnancy at the same gestational age (P < 0.0001). CONCLUSION: Our data reveal a marked elevation of peripheral blood CD4+CD25+Foxp3+ Tregs during early pregnancy, but a dramatic decline during labor, either at term or preterm, suggesting their involvement in the maintenance of pregnancy and the initiation of labor.