Decrease in Plasma Cyclophilin A Concentration at 1 Month after Myocardial Infarction Predicts Better Left Ventricular Performance and Synchronicity at 6 Months: A Pilot Study in Patients with ST Elevation Myocardial Infarction

Background: Cyclophilin A (CyPA) concentration increases in acute coronary syndrome. In an animal model of acute myocardial infarction, administration of angiotensin-converting-enzyme inhibitor was associated with lower left ventricular (LV) CyPA concentration and improved LV performance. This study investigated the relationships between changes in plasma CyPA concentrations and LV remodeling in patients with ST-elevation myocardial infarction (STEMI).Methods and Results: We enrolled 55 patients who underwent percutaneous coronary intervention for acute STEMI. Plasma CyPA, matrix metalloproteinase (MMP), interleukin-6 and high-sensitivity C-reactive protein concentrations were measured at baseline and at one-month follow-up. Echocardiography was performed at baseline and at one-, three-, and six-month follow-up. Patients with a decrease in baseline CyPA concentration at one-month follow-up (n = 28) had a significant increase in LV ejection fraction (LVEF) (from 60.2 ± 11.5% to 64.6 ± 9.9%, p < 0. 001) and preserved LV synchrony at six months. Patients without a decrease in CyPA concentration at one month (n = 27) did not show improvement in LVEF and had a significantly increased systolic dyssynchrony index (SDI) (from 1.170 ± 0.510% to 1.637 ± 1.299%, p = 0.042) at six months. Multiple linear regression analysis showed a significant association between one-month CyPA concentration and six-month LVEF. The one-month MMP-2 concentration was positively correlated with one-month CyPA concentration and LV SDI.Conclusions: Decreased CyPA concentration at one-month follow-up after STEMI was associated with better LVEF and SDI at six months. Changes in CyPA, therefore, may be a prognosticator of patient outcome.     

促红细胞生成素对血液透析患者血浆脂联素水平及左心室肥厚的影响

目的：促红细胞生成素（EPO）在维持性血液透析患者中具有保护心血管的作用,本文旨在探讨EPO在血液透析病人中对脂联素（ADPN）水平及左心室肥厚的影响。方法：46名维持性血液透析患者用EPO治疗8周,分别在治疗前,治疗第2、4、8周后测定血红蛋白（Hb）,红细胞压积（Hct）,血浆白蛋白（ALB）,体重指数（BMI）,C反应蛋白（CRP）,血清铁蛋白（SF）,血清铁饱和度（TAST）,ELISA测定ADPN水平;彩色多普勒超声测定左心室心肌重量（LVM）及计算左心室心肌重量指数（LVMI）。结果：血液透析患者血清ADPN水平高于正常人;用EPO治疗2周后即出现ADPN水平升高,第4周后ADPN水平进一步升高,第8周与第4周比较无明显变化;应用EPO可降低CRP、SF水平;ADPN是LVMI的重要影响因子,EPO可改善左心室肥厚与功能。结论：EPO可提高血液透析患者ADPN水平,降低CRP、SF水平,减轻左心室肥厚。     

PDIA1 和EF1D 在左侧和右侧结肠癌差异表达的实验研究

目的:初步确定蛋白质二硫化异构酶A1和延伸因子1-delta为左侧和右侧结肠癌中差异表达蛋白,为左侧和右侧结肠癌在肿瘤生物学方面的差异提供分子遗传学依据。方法:收集人左侧结肠癌(LSCC)和右侧结肠癌(RSCC)组织标本,进行二维凝胶电泳、质谱分析和生物信息学分离和鉴定左右侧结肠癌中差异表达蛋白质,进一步应用RT-PCR、Western Blot和免疫组织化学技术检测蛋白质二硫化异构酶A1和延伸因子1-delta在左侧和右侧结肠癌中的表达状态。结果:筛选并成功鉴定出左侧和右侧结肠癌中16种差异表达蛋白质,与右侧结肠癌比较,10种蛋白在左侧结肠癌表达上调,6种蛋白在左侧结肠癌表达下调,其中蛋白质二硫化异构酶A1在左侧结肠癌中表达上调,延伸因子1-delta在左侧结肠癌中表达下调,并通过RT-PCR、Western Blot和免疫组化方法证实了在左侧和右侧结肠癌中该两种蛋白表达的差异,与蛋白质组学结果一致。结论:左侧结肠癌和右侧结肠癌的蛋白质组存在差异,其中蛋白质二硫化异构酶A1和延伸因子1-delta在mRNA和蛋白水平均存在差异,这些可能是左侧和右侧结肠癌生物学行为差异的原因。     

Modeling late entry bias in survival analysis

In a failure time analysis, we sometimes observe additional study subjects who enter during the study period. These late entries are treated as left-truncated data in the statistical literature. However, with real data, there is a substantial possibility that the delayed entries may have extremely different hazards compared to the other standard subjects. We focus on a situation in which such entry bias might arise in the analysis of survival data. The purpose of the present article is to develop an appropriate methodology for making inference about data including late entries. We construct a model that includes parameters for the effect of delayed entry bias having no specification for the distribution of entry time. We also discuss likelihood inference based on this model and derive the asymptotic behavior of estimates. A simulation study is conducted for a finite sample size in order to compare the analysis results using our method with those using the standard method, where independence between entry time and failure time is assumed. We apply this method to mortality analysis among atomic bomb survivors defined in a geographical study region.     

A mean field Ising model for cortical rotation in amphibian one-cell stage embryos

We propose a new physical mechanism of cortical rotation generation in one-cell embryos of amphibians based on a phase transition in the ensemble of microtubules localized to the cortical region of the cell interior. Microtubules, protein polymers formed from tubulin heterodimers, are highly negatively charged, which results in strong electrostatic interactions over tens of nanometers, even in the presence of counterions that partially screen electrostatic interactions. A simplified model that offers a plausible representation of these effects is based on the Ising Hamiltonian, which has been robustly applied to explain a wide range of order-disorder transitions in physics, chemistry and other sciences. An Ising model phase transition, especially with the supercooperative flow alignment effect of global rotation of the cortex, provides an alternative to models of cortical rotation based on microtubule polymerization or motor molecules. Insofar as there is any reality to the concept that microtubules are involved in consciousness, we propose that cortical rotation in the one-cell embryo is a better place to look for the purported microtubule entanglement or coherence properties than the adult brain.     

The natriuretic peptide time-course in end-stage heart failure patients supported by left ventricular assist device implant: focus on NT-proCNP

This study aimed to evaluate left ventricular assist device (LVAD) effects on natriuretic peptide (NP) prohormone plasma levels in end-stage heart failure (HF) patients, especially NT-proCNP, in order to better characterize the NP system during hemodynamic recovery by LVAD. HF patients (n=17, NYHA III-IV) undergoing LVAD were studied: 6 died of multi-organ failure syndrome (NS) and 11 survived (S). Total sequential organ failure assessment (t-SOFA) score and blood samples were obtained at admission (T1) and at 24, 72h and 1, 2, 4 weeks (T2-T6) after LVAD. In S, NT-proANP and NT-proCNP significantly increased at 24h after implantation, reaching a reduction to basal levels at 4 weeks following LVAD [NT-proANP: T1 vs. T2 p=0.017, NT-proCNP: T1 vs. T2 p=0.028, T1 vs. T3 p=0.043]. Elevated NT-proBNP plasma levels were observed at all times. In NS, NP plasma levels sustained higher with respect to S. No statistical variation was observed for NT-proCNP and NT-proANP in S and NS while NT-proBNP reached significant differences at T4 in NS. Considering S+NS, only NT-proCNP strongly correlated with t-SOFA score at T1 (rho=0.554, p=0.04) while subdividing patients NT-proCNP positively correlated in NS with t-SOFA score (rho=0.988, p=0.002) only at T4. In NS a correlation between NT-proCNP and NT-proBNP at T1 was observed (rho=-0.900, p=0.037). Both IL-6 and TNF-alpha sustained higher in NS patients than in S; in particular, statistical significance was observed for IL-6. The study of new peptides, such as NT-proCNP, would provide additional information for identifying patients who are more likely to recover.     

1956-2009年内蒙古苏尼特左旗荒漠草原的降水格局

弄清全球变化背景下不同地区降水格局的变化对科学理解气候变化及其影响具有重要意义。苏尼特左旗荒漠草原是温带干旱半干旱地区的典型荒漠草原,对气候变化,特别是降水变化非常敏感。利用1956-2009年的日降水资料探讨了苏尼特左旗荒漠草原降水格局的变化规律,以为揭示气候变化的影响机制提供依据。结果表明,该地区年均降水量为191.9 mm,年际变化剧烈,变异系数达26.63%;年均降水日数为63.8 d,变异系数16.9%。生长季降水占全年的85%,但各月变异系数均>50%;降水日数占全年的63%。年和生长季的各月降水以中等降水量、弱降水日数为主,中等强度以上降水事件较少。近50 a来,年和生长季的降水量、降水日数与各等级降水事件均呈下降趋势,年降水减少的原因在于中等降水事件的减少、生长季降水减少的原因在于弱降水事件的减少。年降水减少将影响草地的土壤水分与植物返青;而生长季降水减少将直接影响草地固碳。气候变化背景下年与生长季降水的减少将进一步加剧该地区干旱程度并影响植物的生长发育,从而直接威胁到草地畜牧业的发展。     

微电极阵列芯片技术研究48h房颤犬左、右心耳电生理特性

目的应用微电极阵列芯片（microelectrode arrays chip,MEA）技术评价48 h房颤（atrial fibrillation,AF）犬左、右心耳（LAA、RAA）的电生理特性。方法随意来源犬12只,以600次/分起搏右心房建立AF模型,分为48 h AF组（n=6）和对照组（n=6）。造模成功后迅速开胸剪取LAA、RAA,置于盛有台式液的MEA中,分别记录AF组及对照组LAA、RAA场电位（field action potential,FAP）形态、振幅、放电频率及激动传导情况。结果 AF组LAA、RAA组织FAP节律绝对不齐,LAA（185.22±25.62）次/分,较对照组（156.44±8.88）次/分增加15.67%（P〈0.01）,RAA（102.39±16）次/分,较对照组（156.44±8.88）次/分减慢34.62%（P〈0.01）。48 h AF组LAA组织电压（458.33±26.73）μV较对照组（740.55±18.93）μV降低38.11%（P〈0.01）,RAA（504.83±39.93）μV较对照组（840.56±18.93）μV明显降低（P〈0.01）,48 h房颤组LAA组织FAP时程（45.28±8.59）ms较对照组（70.77±6.98）ms缩短15 ms（P〈0.01）。RAA（61.78±7.1）ms较对照组（75.83±7.63）ms缩短14 ms（P〈0.01）。48 h AF组LAA、RAA FAP传导异质性增加。结论应用MEA技术可反映心肌组织片场电位电生理特性,48 h AF后LAA放电频率增加,频率绝对不齐,LAA、RAA电压降低,场电位时程延长。     

组织多普勒成像对射血分数正常的心衰患者左心功能评价

目的:探讨组织多普勒成像(TDI)技术评价射血分数正常的心衰患者左室长轴功能特点。方法:选取30名健康人(Ⅰ组)、EF>50%的心衰患者30名(Ⅱ组)和EF<50%的心衰患者30名(Ⅲ组)作为研究对象,采用TDI在二尖瓣环室间隔(ivs)、侧壁(l)、前壁(a)、后壁(p)、下壁(d)测量其Sm、DSm、IVCTm、TSm、Em、Am、IVRTm、TEm等指标。结果:Ⅰ组、Ⅱ组、Ⅲ组DSm、Sm逐渐减低,(P<0.05);而IVCTm、TSm逐渐升高(P<0.05);IVRTm、TEm在Ⅰ组、Ⅲ组、Ⅱ组逐渐升高(P<0.05);DSm及TEm在诊断EF>50%心衰患者心功能的指标中ROC曲线下面积最大,同样DSp及TEp在五个位点中ROC曲线下面积最大。结论:射血分数正常的心衰患者存在收缩减低;DSm及TEm是诊断EF>50%心衰患者心功能比较有效的指标;后壁是诊断的最佳位点。