心血管老化和心力衰竭

老年人心血管系统的老化是很明显的,动脉硬化改变了后负荷以及左心室的形状.尽管左心室的心脏收缩功能仍然能够维持,但是左心室的舒张功能则大大改变.运动时老年人的心血管功能产生明显的改变,老年人可以通过运动训练改善心血管功能.老化引起心血管结构和功能改变,从而降低心脏疾病出现的阈值.对老年人在运动或休息时心血管结构和功能的改变进行了综述.     

Inhibition of proliferation and differentiation and promotion of apoptosis by cyclin L2 in mouse embryonic carcinoma P19 cells

Cyclin L2 (CCNL2) is a novel member of the cyclin gene family. In a previous study, we demonstrated that CCNL2 expression was upregulated in ventricular septum tissues from patients with ventricular septal defect compared to healthy controls. In the present study, we established a stable CCNL2-overexpressing P19 cell line that can differentiate to myocardial cells when treated with 1% dimethyl sulfoxide (DMSO). Our data showed that stable CCNL2-overexpressing P19 cells were less differentiated after treatment with 1% DMSO and that expression of myocardial cell differentiation-related genes (such as cardiac actin, GATA4, Mef2C, Nkx2.5, and BNP) were reduced compared to vector-only transfected P19. Moreover, P19 cells overexpressing the CCNL2 gene had a reduced growth rate and a remarkably decreased S phase. We also found that these cells underwent apoptosis, as detected by two different apoptosis assays. The anti-apoptotic Bcl-2 protein was also downregulated in these cells. In addition, real-time PCR analysis revealed that expression of Wnt and β-catenin was suppressed and GSK3β was induced in the CCNL2-overexpressing P19 cells. These data suggest that overexpression of CCNL2 inhibited proliferation and differentiation of mouse embryonic carcinoma P19 cells and induced them to undergo apoptosis, possibly through the Wnt signal transduction pathway.     

Occurrence of proteins immunoreactive with anti-coupling factor B in phosphorylating membrane preparations

Coupling factor B has been isolated from beef heart mitochondria, apparently in multiple forms which differ in molecular weight and specific activity. Since it has no known intrinsic catalytic activity, detection and quantitation have been based upon the factor B-dependent stimulation of ATP-linked activities in factor B-deficient submitochondrial particles. This communication reports the development of a reliable and more universally applicable enzyme-linked immunosorbent assay (ELISA) for detection and quantitation of factor B in soluble or membranous preparations. The assay requires nanoliter volumes of rabbit antiserum raised against purified factor B and will detect nanogram amounts of the coupling factor. Analysis of beef heart submitochondrial particles using a competitive binding ELISA indicated a factor B content of 0.27 nmol/mg protein, making factor B stoichiometric with F₁ (0.3–0.6 nmol/mg). Furthermore, application of the factor B ELISA has indicated the presence of material cross-reacting with the beef heart factor B-antiserum in phosphorylating membranes from chloroplasts, Escherichia coli, Paracoccus denitrificans and the thermophilic bacterium, PS3. Negative results were obtained with mitochondria and microsomes from rat liver, purple membranes from Halobium halobacterium and sarcoplasmic reticulum from rabbit skeletal muscle.     

On the performance of adaptive preprocessing technique in analyzing high‐dimensional censored data

Preprocessing for high‐dimensional censored datasets, such as the microarray data, is generally considered as an important technique to gain further stability by reducing potential noise from the data. When variable selection including inference is carried out with high‐dimensional censored data the objective is to obtain a smaller subset of variables and then perform the inferential analysis using model estimates based on the selected subset of variables. This two stage inferential analysis is prone to circularity bias because of the noise that might still remain in the dataset. In this work, I propose an adaptive preprocessing technique that uses sure independence screening (SIS) idea to accomplish variable selection and reduces the circularity bias by some popularly known refined high‐dimensional methods such as the elastic net, adaptive elastic net, weighted elastic net, elastic net‐AFT, and two greedy variable selection methods known as TCS, PC‐simple all implemented with the accelerated lifetime models. The proposed technique addresses several features including the issue of collinearity between important and some unimportant covariates, which is often the case in high‐dimensional setting under variable selection framework, and different level of censoring. Simulation studies along with an empirical analysis with a real microarray data, mantle cell lymphoma, is carried out to demonstrate the performance of the adaptive pre‐processing technique.     

微信平台健康教育在肺心病患者延续护理中的应用

目的：探讨微信平台健康教育在慢性肺源性心脏病（肺心病）患者延续护理中的效果，为临床护理工作提供依据。方法：将90 名肺心病患者按出院顺序分成观察组和对照组，各45 例，对照组进行定期随访，观察组利用微信平台进行健康教育，6 个月后评 价两组患者的遵医行为，并采用慢性肺源性心脏病患者生命质量测定量表（QLICD-CPHD）于患者出院时及6 个月后进行生活质 量评价。结果：观察组患者具有很好的遵医行为，对照组遵医行为较差，两组比较有显著差异（P<0.01）。两组患者干预前生活质量 比较无显著差异（P＞0.05）；观察组在干预前后，生活质量各模块无明显改变（P＞0.05），对照组生活质量各模块明显降低，与观察 组比较，差异有统计学意义（P<0.05）。结论：微信教育在一定程度上能够地提高患者的遵医行为,弥补传统健康教育的不足，提升 了健康教育的效果，值得临床借鉴。     

GENETIC SIMILARITY BETWEEN PARENTS PREDICTS HATCHING FAILURE: NONINCESTUOUS INBREEDING IN THE GREAT REED WARBLER?

The DNA-fingerprinting technique was used to find the true pedigrees and to detect the overall genetic similarity between mates of great reed warblers (Acrocephalus arundinaceus) at an isolated breeding site in Sweden. The study covered 4 yr preceded by 3 yr when almost all adults and nestlings in the study area had been banded. DNA fingerprinting revealed that the putative father had sired 97% of the young (N = 455). The mate's genetic similarity, revealed as the proportion of bands shared in restriction fragment length polymorphism (RFLP) patterns, was high compared with other species of wild birds. Also, band sharing was higher between mates native to the area than between pairs in which the female was experimentally introduced from a distant breeding site. Hatching success of eggs was negatively correlated with the degree of genetic similarity between the mates, whereas pedigree data, up to the level of great-grandparents, clearly demonstrated an absence of close inbreeding. These are the first data showing a significant fitness cost associated with the choice of a mate that has high genetic similarity, even if it is not a close kin. This cost might be caused by generalized negative consequences of genomewide inbreeding in the present study, possibly accentuated by recent population bottlenecks.     

Ventricular flow dynamics with varying LVAD inflow cannula lengths: In-silico evaluation in a multiscale model

Left ventricular assist devices are associated with thromboembolic events, which are potentially caused by altered intraventricular flow. Due to patient variability, differences in apical wall thickness affects cannula insertion lengths, potentially promoting unfavourable intraventricular flow patterns which are thought to be correlated to the risk of thrombosis. This study aimed to present a 3D multiscale computational fluid dynamic model of the left ventricle (LV) developed using a commercial software, Ansys, and evaluate the risk of thrombosis with varying inflow cannula insertion lengths in a severely dilated LV. Based on a HeartWare HVAD inflow cannula, insertion lengths of 5, 19, 24 and 50 mm represented cases of apical hypertrophy, typical ranges of apical thicknesses and an experimental length, respectively. The risk of thrombosis was evaluated based on blood washout, residence time, instantaneous blood stagnation and a pulsatility index. By introducing fresh blood to displace pre-existing blood in the LV, after 5 cardiac cycles, 46.7%, 45.7%, 45.1% and 41.8% of pre-existing blood remained for insertion lengths of 5, 19, 24 and 50 mm, respectively. Compared to the 50 mm insertion, blood residence time was at least 9%, 7% and 6% higher with the 5, 19 and 24 mm insertion lengths, respectively. No instantaneous stagnation at the apex was observed directly after the E-wave. Pulsatility indices adjacent to the cannula increased with shorter insertion lengths. For the specific scenario studied, a longer insertion length, relative to LV size, may be advantageous to minimise thrombosis by increasing LV washout and reducing blood residence time.     

Morphologische Untersuchungen von Putenherzen nach Aufnahme von Fusarientoxinen durch das Futter

100 turkey poults (1 day of age) were housed in 16 boxes, each containing 6–7 animals. In each case 4 boxes constituted 4 feeding groups. One was the control group and the other three received a feed containing different quantities of the mycotoxin moniliformin (0.8; 1.6; 2.4 mg/kg) and beauvericin (0.8; 1.7; 2.5 mg/kg). The animals were fed for 12 weeks and then slaughtered. Pieces of the heart were examined by routine histology. The microscopical evaluation showed cell infiltration into the heart muscle and alterations of the heart muscle. However, a relation could be detected between the mycotoxin concentration in the feed and the frequency and the quality of heart alterations.

Presented at the 25^th Mykotoxin Workshop in Giessen, Germany, May 19–21, 2003     

An anisotropic constitutive model for immersogeometric fluid–structure interaction analysis of bioprosthetic heart valves

This paper considers an anisotropic hyperelastic soft tissue model, originally proposed for native valve tissue and referred to herein as the Lee–Sacks model, in an isogeometric thin shell analysis framework that can be readily combined with immersogeometric fluid–structure interaction (FSI) analysis for high-fidelity simulations of bioprosthetic heart valves (BHVs) interacting with blood flow. We find that the Lee–Sacks model is well-suited to reproduce the anisotropic stress–strain behavior of the cross-linked bovine pericardial tissues that are commonly used in BHVs. An automated procedure for parameter selection leads to an instance of the Lee–Sacks model that matches biaxial stress–strain data from the literature more closely, over a wider range of strains, than other soft tissue models. The relative simplicity of the Lee–Sacks model is attractive for computationally-demanding applications such as FSI analysis and we use the model to demonstrate how the presence and direction of material anisotropy affect the FSI dynamics of BHV leaflets.     

急性呼吸系统感染与气象因素的相关性分析研究

目的:分析研究急性呼吸系统感染与气象因素的相关性。方法:记录2011年1月-2012年12月上海市胸科医院急诊就诊的急性呼吸系统感染人数,并采用SPSS19.0与同期气象资料进行相关性分析。结果:发现急性呼吸系统感染具有冬季高发、夏季低发的特征。急性呼吸感染人数与平均气温、最高气温、最低气温呈显著负相关,而与日平均气压呈显著正相关。温度对呼吸系统感染数影响具有滞后效应。结论:气温、气压等气象因素与呼吸系统感染发病有明显相关。