The auricular myocardiocytes of the heart constitute an endocrine organ characterization of a porcine cardiac peptide hormone,cardiodilatin-126

Summary A peptide hormone was extracted from the porcine right atrium following a bioassay for differential vaso-relaxant effects on smooth muscle strips from aorta and renal and inferior mesenteric arteries. The isolation procedure included several steps of gel-permeation and ion-exchange chromatography, and high performance liquid chromatography. During the isolation procedure, other peptides of smaller molecular weight were also found, which, in relation to cardiodilatin-126 (CDD-126), are shorter at their N-terminal. Among these, CDD-88 has also been isolated and characterizied, and has been established as a prominent member of the cardiac hormone family. The N-terminal and C-terminal segments of the 126 amino acid-containing molecule were synthesized and used to raise region-specific antibodies. The natural peptide was then localized within myoendocrine cells of the right atrium where specific atrial granules are located. Renal effects of cardiodilation were studied in conscious dogs and showed strong diuretic and natriuretic activities. According to our functional studies, cardiodilatin-126 and cardiodilatin-88 possess qualities of a significant hormone family regarding the regulation of extracellular fluid volume and blood pressure.     

通心络对急性心肌梗死保守治疗患者疗效观察

目的:观察通心络胶囊对急性心肌梗死(AMI)未接受经皮冠状动脉介入治疗(PCI)或溶栓治疗后患者的疗效。方法:对我院收治的ST段抬高未实施PCI或溶栓治疗的AMI患者,随机分为常规药物治疗作为对照组(20例)和同时加服用通心络胶囊的治疗组(20例)。于发病后一月内观察再发心绞痛、急性心血管事件、左室射血分数(LVEF)改变。结果:通心络组心功能改善较对照组明显,通心络组再发心绞痛及急性心血管事件较对照组明显减少。结论:通心络对急性心肌梗死保守治疗患者不仅减少心绞痛发作及急性心血管事件的发生而且可改善心功能。     

The effect of adrenaline on the temperature dependency of cardiac action potentials in pink salmon Oncorhynchus gorbuscha

Using sharp electrode impalement, action potentials recorded from atrial and ventricular tissue of pink salmon Oncorhynchus gorbuscha generally decreased in duration with increasing test temperature (6, 10, 16 and 20° C). Stimulation of the tissue using 500 nM adrenaline had no significant effect on the duration of the atrial action potential at any test temperature but lengthened the ventricular action potential by ~17%.     

The impact of confounders on the test performance of natriuretic peptides for cardiac dysfunction in subjects aged 80 and older

The hypothesis that natriuretic peptides could be used to identify ‘pancardiac’ damage has been proposed. However, multiple factors are known to influence circulating levels of natriuretic peptides, especially in the very old. Therefore, the impact of confounders on the association between natriuretic peptide levels and cardiac dysfunction was further explored in subjects aged 80 and older. A diagnostic cross-sectional study embedded within the BELFRAIL study (n = 567) was performed. Baseline BNP and NT-proBNP levels were measured and echocardiograms were performed at the subject's home. Cardiac dysfunction was defined as systolic dysfunction, valvular heart disease or isolated severe diastolic dysfunction. Several functional and structural echocardiographic parameters were independently related to circulating levels of natriuretic peptides. Cystatin C, BMI, β blockers, diabetes, heart frequency, usCRP, age and sex were identified as confounders. The prevalence of cardiac dysfunction was 17.1% in the subjects without and 30.8% in the subjects with chronic atrial fibrillation (CAF) or pacemaker (PM). Only in subjects with CAF or PM the C statistic for cardiac dysfunction improved after correcting for confounders. The post-test probability for a negative test (PTP−) ranged from 3.7% to 12.2% and the PTP+ ranged from 21.9% to 62.2% in different strata of confounders. According to these data adjusting for identified confounders does not improve the diagnostic accuracy of the natriuretic peptides for cardiac dysfunction, except in subjects with CAF or PM. Stratifying for individual confounders showed that different cut-off values could be used to optimize the diagnostic characteristics of natriuretic peptides.     

Massive conformation change in the prion protein: Using dual-basin structure-based models to find misfolding pathways

We employ all-atom structure-based models with a force field with multiple energetic basins for the C-terminal (residues 166-226) of the mammalian prion protein. One basin represents the known alpha-helical (αH) structure while the other represents the same residues in a left-handed beta-helical (LHBH) conformation. The LHBH structure has been proposed to help describe one class of in vitro grown fibrils, as well as possibly self-templating the conversion of normal cellular prion protein to the infectious form. Yet, it is unclear how the protein may make this global rearrangement. Our results demonstrate that the conformation changes are not strongly limited by large-scale geometry modification and that there may exist an overall preference for the LHBH conformation. Furthermore, our model presents novel intermediate trapping conformations with twisted LHBH structure.     

Changes of collagen metabolism predict the left ventricular remodeling after myocardial infarction

Objectives: To analyze the predictive value of cardiac collagen metabolism “in vivo" in patients with myocardial infarction (MI) treated with percutaneous coronary intervention (PCI). Design: Forty-five patients (age 66 ± 8.27) underwent biochemical analysis for cardiac collagen metabolism (groups A, B and C); 30 patients with their first MI were treated with successful PCI (group A; n = 30), group B (n = 5) were MI patients with unsuccessful PCI. Group C were patients without MI (n = 10), they underwent elective diagnostic coronary angiography only. The collagen metabolism was analyzed in acute and subacute MI phases by using serum blood markers: the carboxy-terminal propeptide of type I procollagen (PICP), amino-terminal propeptide of type III procollagen (PIIINP) and carboxy-terminal telopeptide of type I collagen (ICTP). Furthermore, the ejection fraction (EF) and left ventricular end-diastolic volume maximal changes in the course of 6 months were measured by echocardiography. Results: A significant increase of both PICP and PIIINP on day 4 following MI was detected. Furthermore, PICP and PIIINP level assessed on the 30th day was significantly higher in the PCI unsuccessful group versus successful group. PICP level on day 4 above 110 ug/l and PIIINP level above 4 ug/l was significantly often found in the subgroup of patients with the EF improvement less than 10% or worsening and with significant left ventricular dilatation during 6 months follow-up. Cardiac catheterization itself does not affect collagen metabolism. Conclusion: We concluded that collagen metabolism markers enable to study in vivo the MI healing and to predict left ventricular functional and volume changes.     

TGF-β superfamily regulates a switch that mediates differentiation either into adipocytes or myocytes in left atrium derived pluripotent cells (LA-PCS)

Many stem cell studies have focused on the subject of cell fate and the signal molecules that modulate the regulatory switches for a given differentiation pathway. Genome-wide screens for cell fate determination signals require a cell source that differentiates purely into a single cell type. From adult rat left atrium, we established LA-PCs that differentiates into cardiac/skeletal myocytes or adipocytes with almost 100% purity. In this study, we compared gene expression profiles of undifferentiated LA-PCs with those of differentiated cells [adipocytes (Adi) or cardiac/skeletal myocytes (Myo)] to identify the signals that set the regulatory switch for adipocyte or myocyte differentiation. Microarray analysis verified the feasibility of genome-wide screening by this method. Using a pathway analysis screen, we found that members of the TGF-β superfamily signal transduction pathways modulate the adipocyte/myocyte differentiation switch. Further analysis determined that recombinant TGF-β inhibits adipogenesis and induces myogenesis simultaneously in a dose-dependent manner. Moreover, noggin induces differentiation into fully developed beating cardiac myocytes in vitro. These results provided new insight into the molecules that modulate the differentiation switch and validated a screening method for their identification.     

科尔沁沙地蒙古族户级水平庭园植物多样性分析——以内蒙古通辽市科尔沁左翼后旗的研究为例

为了表明农户庭园在户级水平上对农业生物多样性保护的作用,在内蒙古通辽市科尔沁左翼后旗采用随机抽样和农户推荐选择20个农户,同时在邻近地区的汉族地区选择10个农户作为对比分析。在此基础上对其家庭庭园采用典型取样法设立30个样方进行调查。结果表明：巴首嘎查庭园植物有100种、哈日乌苏种畜场共有84种、公济号村有87种,包括栽培及野生蔬菜、水果、观赏、药用、饲用等植物。三个村庄庭园植物物种丰富度分析比较发现巴首嘎查的物种丰富度相对最高,而哈日乌苏种畜场的相对最低,反映巴首村对庭园物种多样性保护的贡献相对最大。这些差异是由于自然条件、庭园面积、庭园历史、庭园管理条件及庭园管理者、当地农牧民对庭园植物的传统知识和文化的认识的差异所造成。文末还对调查的三个村庄的庭园植物进行了初步编目。