Mutations in the genes low-density lipoprotein (LDL) receptor-related protein-6 (LRP6) and myocyte enhancer factor 2A (MEF2A) were reported in families with coronary artery disease (CAD). We intend to determine the mutational spectrum of these genes among hyperlipidemic and normolipidemic CAD families. Forty probands with early-onset CAD were recruited from 19 hyperlipidemic and 21 normolipidemic Chinese families. We sequenced all exons and intron-exon boundaries of LRP6 and MEF2A, and found a novel heterozygous variant in LRP6 from a proband with normolipidemic CAD. This variant led to a substitution of histidine to tyrosine (Y418H) in an evolutionarily conserved domain YWTD in exon 6 and was not found in 1025 unrelated healthy individuals. Co-segregated with CAD in the affected family, LRP6_Y418H significantly debilitated the Wnt3a-associated signaling pathway, suppressed endothelial cell proliferation and migration, and decreased anti-apoptotic ability. However, it exhibited no influences on low-density lipoprotein cholesterol uptake. Thus, mutation Y418H in LRP6 likely contributes to normolipidemic familial CAD via impairing endothelial cell functions and weakening the Wnt3a signaling pathway.

Background: The prediction accuracy of pulse pressure variation (PPV) for fluid responsiveness was proposed to be unreliable in low tidal volume (Vt) ventilation. It was suggested that changes in PPV obtained by transiently increasing Vt to 8 ml/kg accurately predicted fluid responsiveness even in subjects receiving low Vt. We assessed whether the changes in PPV induced by a Vt challenge predicted fluid responsiveness in our critically ill subjects ventilated with low Vt 6 ml/kg. Methods: This study is a prospective single-center study. PPV and other parameters were measured at a Vt of 6 mL/kg, 8 mL/kg, and after volume expansion. The prediction accuracy of PPV and other parameters for fluid responsiveness before and after tidal volume challenge was also analyzed using receiver operating characteristic (ROC) curves. Results: Thirty-one of the 76 subjects enrolled in the study were responders (41%). Respiratory system compliance of all subjects decreased significantly (26 ± 4.3). The PPV values were significantly higher in the responder group than the non-responder group before (8.8 ± 2.7 vs 6.8 ± 3.1) or after (13.0 ± 1.7 vs 8.5 ± 3.0) Vt challenge. In the receiver operating characteristic curve (ROC) analysis, PPV₆ showed unsatisfactory predictive capability with an area under the curve (AUC) of 0.69 (95%CI, 0.57–0.79, p = 0.002) at a Vt of 6 mL/kg. PPV₈ andΔPPV_6–8 showed good predictive capability with an AUC of 0.90 (95% CI, 0.81–0.96, p < 0.001) and 0.90 (95% CI, 0.80–0.95, P < 0.001) respectively. The corresponding cutoff values were 11% for PPV₈ and 2% for ΔPPV_6–8. Conclusions: PPV shows a poor operative performance as a predictor of fluid responsiveness in critically ill subjects ventilated with a tidal volume of 6 mL/ kg. Vt challenge could improve the predictive accuracy of PPV to a good but not excellent extent when respiratory system compliance decreased significantly.

Background and Purpose— The first genomewide association study of ischemic stroke in whites has identified multiple susceptibility loci. We confirmed this study by examining associations with ischemic stroke in a Chinese Han population. Methods— Twenty-five common variants were genotyped in a relatively large sample size including 1123 subjects with ischemic stroke cases (thrombosis stroke=716, lacunar infarction=407) and 557 normal control subjects. The association analyses were performed at both single nucleotide polymorphism and haplotype levels. False discovery rate q value method was applied for multiple testing corrections. Results— rs11052413, a intergenic single nucleotide polymorphism, was most significantly associated with ischemic stroke independent of traditional cardiovascular risk factors in additive (OR=1.51, 95% CI=1.19 to 1.92, P =7.4×10 ⁻⁴ , q=0.018) and dominant models (OR=1.59, 95% CI=1.20 to 2.08, P =9.2×10 ⁻⁴ , q=0.023). In addition, both ZNF650 rs10204475 and intergenic single nucleotide polymorphism rs10486776 were associated with ischemic stroke as well as independent of traditional cardiovascular risk factors in dominant models (OR=1.47, 95% CI=1.12 to 1.96, P =0.005, q=0.040 and OR=1.53, 95% CI=1.15 to 2.02, P =0.003, q=0.036, respectively). No significant results were found in stroke subtype analysis after multiple corrections. Conclusion— Our study confirmed previously reported associations between ischemic stroke and rs11052413, rs10486776, and ZNF 650 rs10204475 in a Chinese Han population. The mechanism whereby the genetic variants exert their effects on ischemic stroke remains to be further elucidated.