基于CYP2C9和VKORC1基因多态性预测老年房颤患者使用华法林的稳定剂量

目的:探讨CYP2C9和VKORC1基因多态性对房颤患者华法林稳定剂量的影响,建立适合汉族人群老年房颤患者的华法林给药模型,指导华法林个体化抗凝治疗。方法:对200例口服华法林抗凝的老年患者进行CYP2C9和VKORC1基因分型,比较不同基因型房颤患者华法林日均稳定剂量的差异。采用多元线性回归分析法依据CYP2C9和VKORC1基因型、年龄、身高、体质量、合并用药建立华法林稳定剂量计算公式。结果:INR稳定在2.0～3.0之间时,CYP2C9*1/*1基因型患者日均使用华法林剂量(3.87±0.71)mg显著高于CYP2C9*3基因型患者(1.05±0.59)mg;VKORC1-1639AA基因型患者日均使用华法林剂量(2.94±1.03)mg显著低于VKORC1-1639GA/GG基因型患者(5.76±1.12)mg。通过多元线性回归分析得出华法林稳定剂量公式,建立的回归模型中包含年龄、体质量、合并用药、CYP2C9*3和VKORC1-1639基因型,该模型能解释约56.5%个体间华法林剂量差异。结论:基于CYP2C9和VKORC1基因多态性建立的华法林稳定剂量预测公式,能帮助指导华法林在老年房颤患者中的抗凝治疗。     

VKORC1-3673G>A、CYP2C9*3、CYP4F2 rs2108622和CYP2C19*2基因多态性对中国汉族房颤患者华法林维持剂量的影响

目的 探讨VKORC1-3673G>A、CYP2C9^*3、CYP4F2 rs2108622和CYP2C19^*2位点基因多态性对中国汉族房颤患者华法林维持剂量的影响。方法 收集107例服用华法林达维持剂量的汉族房颤患者的血样和临床相关资料,应用PCR-RFLP法检测VKORC1-3673G>A、CYP2C9^*3、CYP4F2 rs2108622和CYP2C19^*2基因型,采用独立样本t检验分析基因型与华法林维持剂量的相关性。多元线性回归建立给药模型,探讨基因多态性对华法林维持剂量的影响。结果 VKORC1-3673G>A、CYP2C9^*3、CYP4F2 rs2108622基因多态性和患者年龄、体质量能解释45.2%的华法林维持剂量差异。CYP2C19^*2基因多态性对本研究人群华法林维持剂量无影响。结论 VKORC1-3673G>A、CYP2C9^*3、CYP4F2 rs2108622基因多态性显著影响中国汉族房颤患者的华法林维持剂量。     

樟芝多糖通过调节肠黏膜浸润的Th9及IL-9的表达调控小鼠慢性结肠炎的机制研究

目的 研究樟芝多糖调节结肠黏膜浸润的Th9及其细胞因子IL-9的表达,从而减轻小鼠慢性结肠炎的机制。方法 利用葡聚糖硫酸钠（dextran sulfate sodium,DSS）构建小鼠慢性结肠炎模型,设置正常组、模型组、阳性对照组（抗IL-9抗体注射组）以及樟芝多糖组（20 mg·kg^-1）。DAI评分综合评价小鼠1个月内活动能力,测定小鼠1个月内的体质量变化,流式细胞术检测外周血、结肠黏膜固有层中单个核细胞中CD4+IL-9+T细胞的比例,ELISA法检测外周血及结肠黏膜中IL-9、TGF-β以及IL-4的表达,实时荧光定量PCR检测小鼠结肠黏膜中IL-9、TGF-β、smad3及IL-4的表达,HE染色观察小鼠结肠组织病理。结果 DSS可以引起小鼠慢性结肠炎性病变,DAI评分结果显示模型组小鼠活动能力明显下降,而樟芝多糖干预后DAI评分显著降低（P<0.05）,模型组小鼠外周血及结肠黏膜固有层中Th9比例相比正常组显著增高（P<0.05）,外周血及结肠黏膜中IL-9、TGF-β及IL-4的蛋白及mRNA表达也显著增高（P<0.05）。阳性对照组及樟芝多糖组小鼠外周血及结肠黏膜固有层中Th9比例相比模型组显著下调（P<0.05）,且外周血及结肠黏膜中IL-9,TGF-β以及IL-4的蛋白及mRNA表达也显著下调（P<0.05）,HE染色结肠病理情况明显好转。结论 樟芝多糖可以通过调节Th9比例和IL-9表达改善小鼠慢性结肠炎,其作用与免疫调节及抗炎作用有关。     

腹主动脉瘤组织原纤维蛋白-1表达水平及其对患者生存结局的影响

目的 探讨腹主动脉瘤组织原纤维蛋白-1(FBN1)表达水平及其对患者生存结局的影响.方法 收集45例腹主动脉瘤(AAA)患者主动脉瘤组织和29例正常腹动脉血管壁组织,免疫组织化学染色检测组织基质金属蛋白酶(MMP9)、FBN1蛋白表达定位,蛋白质免疫印迹法检测组织FBN1、MMP9蛋白表达水平,实时荧光定量PCR检测组织FBN1、MMP9 mRNA表达水平.对45例AAA患者进行随访,分析FBN1表达与患者病理资料及生存结局的关系.结果 FBN1、MMP9主要表达于动脉瘤组织巨噬细胞或平滑肌细胞,主动脉瘤组织FBN1、MMP9蛋白阳性表达率86.7%、93.3%均高于正常动脉壁组织34.5%、48.3%(χ2=21.467,19.450,P<0.001).主动脉瘤组织FBN1、MMP9 mRNA相对表达量分别为(1.89 ±0.19)和(2.29 ± 0.31),正常动脉壁组织分别为(0.79 ±0.15)和(1.32 ±0.12),主动脉瘤组织FBN1、MMP9 mRNA相对表达量高于正常动脉壁组织(t=26.317,t=16.061,P<0.001),差异有统计学意义;主动脉瘤组织FBN1、MMP9蛋白表达量分别为(1.08 ±0.11)和(1.02 ±0.10),正常动脉壁组织分别为(0.29 ±0.06)和(0.39 ±0.07),主动脉瘤组织FBN1、MMP9蛋白表达量高于正常动脉壁组织(t=35.376,t=19.548,P<0.001).对照组FBN1与MMP9表达无相关性(P>0.05),AAA组FBN1与MMP9表达呈成正相关(r=0.861,P<0.05),差异有统计学意义.主动脉瘤破裂及瘤体直径>8.0 cm患者FBN1表达水平高于瘤体直径≤8.0 cm者,差异有统计学意义(P=0.047).FBN1阴性患者5年生存率为87.2%,FBN1阳性患者5年生存率为48.1%,FBN1阴性组5年生存率高于阳性组(χ2=17.081,P<0.05).结论 腹主动脉瘤组织FBN1表达显著升高,FBN1表达越高,患者生存率越低,FBN1可以作为AAA患者生存结局的评估指标之一.     

Celecoxib is a substrate of CYP2D6: Impact on celecoxib metabolism in individuals with CYP2C9*3 variants

Celecoxib was characterized as a substrate of human cytochrome P450 (CYP) 2D6 in vitro. In recombinant CYP2D6, celecoxib hydroxylation showed atypical substrate inhibition kinetics with apparent K_m, K_i, and V_max of 67.2 μM, 12.6 μM, and 1.33 μM/min, respectively. In human liver microsomes (HLMs), a concentration-dependent inhibition of celecoxib hydroxylation by quinidine was observed after CYP2C9 and CYP3A4 were inhibited. In individual HLMs with variable CYP2D6 activities, a significant correlation was observed between celecoxib hydroxylation and CYP2D6-selective dextromethorphan O-demethylation when CYP2C9 and CYP3A4 activities were suppressed (r = 0.97, P < 0.0001). Molecular modeling showed two predominant docking modes of celecoxib with CYP2D6, resulting in either a substrate or an inhibitor. A second allosteric binding antechamber, which stabilized the inhibition mode, was revealed. Modeling results were consistent with the observed substrate inhibition kinetics. Using HLMs from individual donors, the relative contribution of CYP2D6 to celecoxib metabolism was found to be highly variable and dependent on CYP2C9 genotypes, ranging from no contribution in extensive metabolizers with CYP2C9*1*1 genotype to approximately 30% in slow metabolizers with allelic variants CYP2C9*1*3 and CYP2C9*3*3. These results demonstrate that celecoxib may become a potential victim of CYP2D6-associated drug-drug interactions, particularly in individuals with reduced CYP2C9 activity.     

What is the impact of the 2017 cochrane systematic review and meta-analysis that evaluated the use of PCSK9 inhibitors for lowering cardiovascular disease and mortality?

Introduction: In 2017, Schmidt et al. conducted a Cochrane systematic review and meta-analysis to evaluate the effect of using proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors to reduce low-density-lipoprotein- cholesterol (LDL-C) and cardiovascular disease (CVD). The Cochrane review was a systematic review and meta-analysis of 20 randomized, double-blinded trials that compared the use of PCSK9 inhibitors with statins/ezetimibe, ezetimibe, or placebo for a treatment duration of at least 24 weeks. The use of PCSK9 inhibitors lowered the risk for CVD (OR 0.86 (0.80 to 0.92)) but not mortality (OR 1.02 (0.91 to 1.14)) when compared to placebo.

Areas covered: The following article evaluates the recently published Cochrane review and clarifies the efficacy of PCSK9 inhibitors for improving cardiovascular morbidity and mortality.

Expert opinion: The Cochrane review discussed suggests that PCSK9 inhibitors are effective in lowering LDL-C and the risk of CVD but not the risk of mortality. The higher price of PCSK9 inhibitors is a further deterrent for using them as a substitute for statins – cholesterol lowering medications with history showing they lower mortality. Statins should remain the gold-standard cholesterol-lowering drug class until PCSK9 inhibitors become more affordable and demonstrate consistent efficacy for reducing CVD and mortality.     

A safety evaluation of evolocumab

Introduction: Evolocumab is an injectable, fully human monoclonal antibody and a member of the newest class of low density lipoprotein cholesterol (LDL-C) lowering agents called proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors. The PCSK9 inhibitors are the most significant advance in lipid therapy since the introduction of the first statin 30 years ago.

Areas covered: The PCSK9 monoclonal antibodies have demonstrated a consistently high LDL-C lowering efficacy with and without statins and/or other lipid lowering therapies (LLT). LDL-C levels achieved with these agents are lower than has ever been possible before. This review will focus on the overall safety of evolocumab including cognitive impairment, very low LDL-C levels, new onset diabetes and glucose abnormalities, effect on vitamin E and steroid hormones, liver and muscle abnormalities, and immunogenicity and injection site reactions. The phase II and III clinical trials had relatively low patient-years of exposure, but the open label extension studies and the recently published outcomes trial, FOURIER, will be the focus of this paper. The safety profile of evolocumab to date is remarkable and extremely encouraging as will be demonstrated.

Expert opinion: The PCSK9 inhibitors will be responsible for a new era in lipid therapy that will expand our knowledge of lipid levels and cardiovascular disease (CVD) prevention with an efficacy and safety profile not previously available in clinical practice.     

柚皮苷对H_2O_2诱导H9c2心肌细胞损伤保护作用

目的探讨柚皮苷对H_2O_2诱导的H9c2心肌细胞凋亡的保护作用及机制。方法体外培养H9c2心肌细胞,用H_2O_2诱导建立细胞凋亡模型。实验设对照组、模型组、柚皮苷低、中、高剂量组(10、20、40μmol/L),噻唑蓝法检测细胞活力并用显微镜观察各组细胞形态;原位末端标记法检测H9c2心肌细胞凋亡情况;RT-PCR及Western blot法检测凋亡相关因子Bcl-2、Bax、caspase-3 m RNA及蛋白表达。结果与对照组比较,模型组细胞凋亡率[(17.2±2.1)%]明显升高(P<0.01);与模型组比较,10、20、40μmol/L柚皮苷组细胞凋亡率[分别为(10.7±1.9)%、(5.7±1.2)%、(6.4±1.5)%]均下降(均P<0.05)。与对照组比较,模型组H9c2心肌细胞Bcl-2蛋白表达水平(0.76±0.16)明显下调,Bax、caspase-3蛋白表达水平[分别为(5.42±0.52)、(1.09±0.11)]均上调(均P<0.01);与模型组比较,10、20、40μmol/L柚皮苷组H9c2心肌细胞Bcl-2蛋白表达水平[分别为(1.37±0.11)、(1.65±0.09)、(1.65±0.15)]均上调,Bax、caspase-3蛋白表达水平[分别为(2.78±0.55)、(3.43±0.15)、(2.69±0.26)和(0.59±0.08)、(0.77±0.06)、(0.82±0.05)]均下调(均P<0.05)。结论柚皮苷对H_2O_2诱导的H9c2心肌细胞损伤具有一定保护作用,其机制可能与其对凋亡信号途径的抑制作用有关。     

More Than a “Number”: Perspectives of Prenatal Care Quality from Mothers of Color and Providers

Introduction

African American mothers and other mothers of historically underserved populations consistently have higher rates of adverse birth outcomes than White mothers. Increasing prenatal care use among these mothers may reduce these disparities. Most prenatal care research focuses on prenatal care adequacy rather than concepts of quality. Even less research examines the dual perspectives of African American mothers and prenatal care providers. In this qualitative study, we compared perceptions of prenatal care quality between African American and mixed race mothers and prenatal care providers.