临时起搏器经皮冠状动脉介入术治疗高风险冠状动脉病变的效果观察

目的分析并总结采用临时起搏器在实施经皮冠状动脉介入术治疗高风险冠状动脉病变中的应用效果。方法回顾性分析在临时起搏器支持下实施PCI的18例高危病人的临床资料,分析临时起搏器置入以及冠脉介入的操作情况。结果本组病人置入临时起搏电极起搏成功率达到100％。结论联合应用临时起搏器与经皮冠脉介入术治疗急性心肌梗死（AMI）与慢性血管闭塞性病变患者,能够降低经皮冠脉介入术治疗中由于严重心律失常导致的血液动力学改变,使病人尽快恢复正常心率以及各主要脏器的供血,减少患者的病死率,具有较高的安全性,值得在临床上广泛推广应用。     

Modeling of the influence of gap-junction coupling on synchronization of central and peripheral sinoatrial node cells

Mathematical modeling of the electric activity of pairs of true (central) and latent (peripheral) sinoatrial pacemaker cells coupled through gap junctions revealed that attenuation of coupling conductance increases the beat phase shift; below a critical conductance there is no synchronization. The phase difference also depends on the type of interacting cells, being maximal for a “central”-“peripheral” cell pair.     

Second‐order cooperation: Cooperative offspring as a living public good arising from second‐order selection on non‐cooperative individuals

Switching rate between cooperating and non‐cooperating genotypes is a crucial social evolution factor, often neglected by game theory‐inspired theoretical and experimental frameworks. We show that the evolution of alleles increasing the mutation or phenotypic switching rates toward cooperation is in itself a social dilemma. Although cooperative offspring are often unlikely to reproduce, due to high cost of cooperation, they can be seen both as a living public good and a part of the extended parental phenotype. The competition between individuals that generate cooperators and ones that do not is often more relevant than the competition between cooperators and non‐cooperators. The dilemma of second‐order cooperation we describe relates directly to eusociality, but can be also interpreted as a division of labor or a soma‐germline distinction. The results of our simulations shine a new light on what Darwin had already termed a “special difficulty” of evolutionary theory and describe a novel type of cooperation dynamics.     

Structures of the Human HCN1 Hyperpolarization-Activated Channel

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LSY-2 is essential for maintaining the germ-soma distinction in C. elegans

The mechanisms that specify and maintain the characteristics of germ cells during animal development are poorly understood. In this study, we demonstrated that loss of function of the zinc-finger gene lsy-2 results in various somatic cells adopting germ cells characteristics, including expression of germline-specific P granules, enhanced RNAi activity and transgene silencing. The soma to germ transformation in lsy-2 mutants requires the activities of multiple chromatin remodeling complexes, including the MES-4 complex and the ISW-1 complex. The distinct germline-specific features in somatic cells and the gene expression profile indicate that LSY-2 acts in the Mec complex in this process. Our study demonstrated that lsy-2 functions in the maintenance of the soma-germ distinction.     

左房增大对起搏器术后的老年阵发性房颤患者再发房颤的影响

目的：探讨植入心脏起搏器的老年阵发性房颤患者再发房颤（包括无症状性房颤）发生率及左房容积指数对再发房颤的影响。方法：收集2012年1月-2013年12月在我院起搏器门诊长期随访且未服用抗心律失常药物的起搏器术后老年阵发性房颤患者148例,记录基线特征、超声心动图参数及随访期间内房颤发生情况。分别根据左房容积指数及房颤负荷进行分组,应用Cox回归分析探讨起搏器检测的再发房颤及房颤高负荷的危险因素。结果：患者平均随访时间为22.79个月,期间57.43%的患者再发房颤,22.97%的患者为房颤高负荷,15.54%的患者为无症状房颤。多因素Cox回归分析发现左房增大分别是再发房颤及房颤高负荷的独立危险因素。结论：左房容积指数是预测起搏器术后老年阵发性房颤患者房颤复发及房颤高负荷的独立危险因素。     

Telomere attrition and growth: a life‐history framework and case study in common terns

The relationship between growth and age‐specific telomere length, as a proxy of somatic state, is increasingly investigated, but observed patterns vary and a predictive framework is lacking. We outline expectations based on the assumption that telomere maintenance is costly and argue that individual heterogeneity in resource acquisition is predicted to lead to positive covariance between growth and telomere length. However, canalization of resource allocation to the trait with a larger effect on fitness, rendering that trait relatively invariant, can cause the absence of covariance. In a case study of common tern (Sterna hirundo) chicks, in which hatching order is the main determinant of variation in resource acquisition within broods, we find that body mass, but not telomere length or attrition, varies with hatching order. Moreover, body mass and growth positively predict survival to fledging, whereas telomere length and attrition do not. Using a novel statistical method to quantify standardized variance in plasticity, we estimate between‐individual variation in telomere attrition to be only 12% of that of growth. Consistent with the relative invariance of telomere attrition, we find no correlation between age‐specific body mass or growth and telomere attrition. We suggest that common tern chicks prioritize investment in long‐term somatic state (as indicated by canalization of telomere maintenance) over immediate survival benefits of growth as part of an efficient brood reduction strategy that benefits the parents. As such, interspecific variation in the growth–telomere length relationship may be explained by the extent to which parents benefit from rapid mortality of excess offspring.