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Integrated management of cardiac failure: the cardiac failure clinic

null

《医学前沿(英文)》 2011年 第5卷 第1期   页码 20-25 doi: 10.1007/s11684-011-0106-1

摘要:

The prevalence of the risk factors and the risk of cardiac failure are both increasing in China. This might be the consequence of the changes of the life conditions (emigration to the urban areas, changes in the diet and life style, lack of physical exercise, etc.). The wide range of clinical presentations of cardiac failure (acute or chronic) and of therapeutic approaches (medical or surgical) makes necessary the integration within the same structure of the various experts involved in the diagnosis and the treatment of cardiac diseases. Technologic and human resources required to offer all the options represent a multifaceted commitment which should be focused optimally in dedicated centers. In these centers, collaboration should replace competition between the medical and the surgical cardiac specialists. Development of team work should permit to optimize the cost efficacy of the treatments. Most of all, such a structure will facilitate the translation of innovative therapies between the research centers and clinical facilities.

关键词: cardiac failure     cardiac transplantation     mechanical circulatory support    

Distinct mononuclear diploid cardiac subpopulation with minimal cell–cell communications persists in

《医学前沿(英文)》   页码 939-956 doi: 10.1007/s11684-023-0987-9

摘要: A small proportion of mononuclear diploid cardiomyocytes (MNDCMs), with regeneration potential, could persist in adult mammalian heart. However, the heterogeneity of MNDCMs and changes during development remains to be illuminated. To this end, 12 645 cardiac cells were generated from embryonic day 17.5 and postnatal days 2 and 8 mice by single-cell RNA sequencing. Three cardiac developmental paths were identified: two switching to cardiomyocytes (CM) maturation with close CM–fibroblast (FB) communications and one maintaining MNDCM status with least CM–FB communications. Proliferative MNDCMs having interactions with macrophages and non-proliferative MNDCMs (non-pMNDCMs) with minimal cell–cell communications were identified in the third path. The non-pMNDCMs possessed distinct properties: the lowest mitochondrial metabolisms, the highest glycolysis, and high expression of Myl4 and Tnni1. Single-nucleus RNA sequencing and immunohistochemical staining further proved that the Myl4+Tnni1+ MNDCMs persisted in embryonic and adult hearts. These MNDCMs were mapped to the heart by integrating the spatial and single-cell transcriptomic data. In conclusion, a novel non-pMNDCM subpopulation with minimal cell–cell communications was unveiled, highlighting the importance of microenvironment contribution to CM fate during maturation. These findings could improve the understanding of MNDCM heterogeneity and cardiac development, thus providing new clues for approaches to effective cardiac regeneration.

关键词: mononuclear diploid cardiomyocytes     cell–cell communication     cardiac fibroblast     single-cell RNA sequencing     cardiac regeneration    

Association of cardiac disease with the risk of post-lung transplantation mortality in Chinese recipients

《医学前沿(英文)》 2023年 第17卷 第1期   页码 58-67 doi: 10.1007/s11684-022-0937-y

摘要: The current organ allocation rules prioritize elderly and urgent patients on the lung transplantation (LT) waiting list. A steady increase in the threshold at which age is taken into consideration for LT has been observed. This retrospective cohort study recruited 166 lung transplant recipients aged 65 years between January 2016 and October 2020 in the largest LT center in China. In the cohort, subgroups of patients aged 65–70 years (111 recipients, group 65–70) and 70 years (55 recipients, group 70) were included. Group D restrictive lung disease was the main indication of a lung transplant in recipients over 65 years. A significantly higher percentage of coronary artery stenosis was observed in the group 70 (30.9% vs. 14.4% in group 65–70, P = 0.014). ECMO bridging to LT was performed in 5.4% (group 65–70) and 7.3% (group 70) of patients. Kaplan–Meier estimates showed that recipients with cardiac abnormalities had a significantly increased risk of mortality. After adjusting for potential confounders, cardiac abnormality was shown to be independently associated with the increased risk of post-LT mortality (HR 6.37, P = 0.0060). Our result showed that LT can be performed in candidates with an advanced age and can provide life-extending benefits.

关键词: cardiac disease     mortality     aged population     lung transplantation    

Management of mantle cell leukemia with cardiac involvement leading to cardiogenic shock

null

《医学前沿(英文)》 2014年 第8卷 第2期   页码 254-258 doi: 10.1007/s11684-014-0319-1

摘要:

Mantle cell lymphoma is an aggressive subtype of B cell non-Hodgkin lymphoma. It can progress to leukemic phase but frank leukemic picture at initial presentation is not common. Leukemic phase indicates advance stage of the disease and generally associated with extensive extra-nodal involvement. Pericardial invasion has been reported, however we could not find a report of myocardial infiltration by this disease since the appraisal of the term “mantle cell lymphoma” in 1992. Here we report a case of cardiac involvement by mantle cell leukemia leading to cardiogenic shock which complicates the treatment decisions.

关键词: mantle cell lymphoma     bendamustine     cardiogenic shock    

Effects of RNA interference targeting angiotensin 1a receptor on blood pressure and cardiac hypertrophy

ZHANG Jingqun, SUN Honglei, MA Yexin, WANG Daowen

《医学前沿(英文)》 2008年 第2卷 第1期   页码 19-24 doi: 10.1007/s11684-008-0005-2

摘要: The aim of this study is to investigate the effects of RNA interference (RNAi) targeting angiotensin 1a receptor (AT1a) on blood pressure and cardiac hypertrophy of rats with renovascular hypertension. Two RNAi plasmids, pAT1a-shRNA1 and pAT1a-shRNA2 each carrying a U6 promoter and an AT1a-specific shRNA-coding template sequence corresponding to the sites 928–946, 978–996 of the mRNA transcript, and a control plasmid pCon carrying a nonspecific shRNA-coding sequence were constructed. Thirty Sprague – Dawley rats with renovascular hypertension (2-kidney 1-clip) were randomly divided into 5 equal groups: Control group (without any intervention), pAT1a-shRNA1, pAT1a-shRNA2, pCon groups (with injection of the corresponding plasmid 4 mg/kg respectively into the tail vein), and valsartan group (30 mg/kg·d by gavage). Three weeks after drug administration, pAT1a-shRNA1, pAT1a-shRNA2 and valsartan respectively resulted in decrease of the tail blood pressure by (15.1 ± 5.4), (16.4 ± 8.4) and (30.6 ± 18.2) mmHg. However, the tail blood pressure increased further by about 25 mmHg in both of pCon and control groups. The carotid artery pressures of pAT1a-shRNA1, pAT1a-shRNA2 and valsartan groups were all significantly lower than those of the control and pCon groups. The ratio of left ventricle weight to body weight (LV/BW) of the rats in pAT1a-shRNA1, pAT1a-shRNA2, and valsartan groups decreased significantly than in the control group ( < 0.01), similar to those of the normal SD rats( > 0.05). Histopathological examination showed that the myocardiocytes were significantly hypertrophic and the basal membrane of the aorta was significantly thickened in the control group and such changes were alleviated in the pAT1a-shRNA1, pAT1a-shRNA2 and valsartan groups. Compared with the control group, pAT1a-shRNA1 and pAT1a-shRNA2 groups had lowered expression of AT1 receptor (in the myocardium and the thoracic aorta (all < 0.01); however, there were no significant differences in expression levels of AT1 receptor in valsartan and the control groups ( > 0.05). We conclude that RNAi targeting AT1a receptor inhibits the development of renovascular hypertension and the accompanying cardiac hypertrophy. RNAi technology may become a new strategy of gene therapy for hypertension.

关键词: therapy     Sprague     administration     cardiac hypertrophy     valsartan    

Chronic inhibition of cyclic guanosine monophosphate-specific phosphodiesterase 5 prevented cardiac fibrosis

null

《医学前沿(英文)》 2014年 第8卷 第4期   页码 445-455 doi: 10.1007/s11684-014-0378-3

摘要:

Recent evidences suggested that cyclic guanosine monophosphate-specific phosphodiesterase 5 (PDE5) inhibitor represents an important therapeutic target for cardiovascular diseases. Whether and how it ameliorates cardiac fibrosis, a major cause of diastolic dysfunction and heart failure, is unknown. The purpose of this study was to investigate the effects of PDE5 inhibitor on cardiac fibrosis. We assessed cardiac fibrosis and pathology in mice subjected to transverse aortic constriction (TAC). Oral sildenafil, a PDE5 inhibitor, was administered in the therapy group. In control mice, 4 weeks of TAC induced significant cardiac dysfunction, cardiac fibrosis, and cardiac fibroblast activation (proliferation and transformation to myofibroblasts). Sildenafil treatment markedly prevented TAC-induced cardiac dysfunction, cardiac fibrosis and cardiac fibroblast activation but did not block TAC-induced transforming growth factor-β1 (TGF-β1) production and phosphorylation of Smad2/3. In isolated cardiac fibroblasts, sildenafil blocked TGF-β1-induced cardiac fibroblast transformation, proliferation and collagen synthesis. Furthermore, we found that sildenafil induced phosphorylated cAMP response element binding protein (CREB) and reduced CREB-binding protein 1 (CBP1) recruitment to Smad transcriptional complexes. PDE5 inhibition prevents cardiac fibrosis by reducing CBP1 recruitment to Smad transcriptional complexes through CREB activation in cardiac fibroblasts.

关键词: PDE5     cardiac fibrosis     TGF-β     CREB    

Acetyl salicylic acid attenuates cardiac hypertrophy through Wnt signaling

null

《医学前沿(英文)》 2015年 第9卷 第4期   页码 444-456 doi: 10.1007/s11684-015-0421-z

摘要:

Ventricular hypertrophy is a powerful and independent predictor of cardiovascular morbid events. The vascular properties of low-dose acetyl salicylic acid (aspirin) provide cardiovascular benefits through the irreversible inhibition of platelet cyclooxygenase 1; however, the possible anti-hypertrophic properties and potential mechanism of aspirin have not been investigated in detail. In this study, healthy wild-type male mice were randomly divided into three groups and subjected to transverse aortic constriction (TAC) or sham operation. The TAC-operated mice were treated with the human equivalent of low-dose aspirin (10 mg·kg−1·d−1); the remaining mice received an equal amount of phosphate buffered saline with 0.65% ethanol, which was used as a vehicle. A cardiomyocyte hypertrophy model induced by angiotensin II (10 nmol·L−1) was treated with the human equivalent of low (10 or 100 µmol·L−1) and high (1000 µmol·L−1) aspirin concentrations in plasma. Changes in the cardiac structure and function were assessed through echocardiography and transmission electron microscopy. Gene expression was determined through RT-PCR and western blot analysis. Results indicated that aspirin treatment abrogated the increased thickness of the left ventricular anterior and posterior walls, the swelling of mitochondria, and the increased surface area in in vivo and in vitro hypertrophy models. Aspirin also normalized the upregulated hypertrophic biomarkers, β-myosin heavy chain (β-MHC), atrial natriuretic peptide (ANP), and b-type natriuretic peptide (BNP). Aspirin efficiently reversed the upregulation of β-catenin and P-Akt expression and the TAC- or ANG II-induced downregulation of GSK-3β. Therefore, low-dose aspirin possesses significant anti-hypertrophic properties at clinically relevant concentrations for anti-thrombotic therapy. The downregulation of β-catenin and Akt may be the underlying signaling mechanism of the effects of aspirin.

关键词: aspirin     Akt     cardiac hypertrophy     GSK-3β     Wnt/β-catenin    

PAK1 is a novel cardiac protective signaling molecule

null

《医学前沿(英文)》 2014年 第8卷 第4期   页码 399-403 doi: 10.1007/s11684-014-0380-9

摘要:

We review here the novel cardiac protective effects of the multifunctional enzyme, p21-activated kinase 1 (PAK1), a member of a serine/threonine protein kinase family. Despite the large body of evidence from studies in noncardiac tissue indicating that PAK1 activity is key in the regulation of a number of cellular functions, the role of PAK1 in the heart has only been revealed over the past few years. In this review, we assemble an overview of the recent findings on PAK1 signaling in the heart, particularly its cardiac protective effects. We present a model for PAK1 signaling that provides a mechanism for specifically affecting cardiac cellular processes in which regulation of protein phosphorylation states by protein phosphatase 2A (PP2A) predominates. We discuss the anti-adrenergic and antihypertrophic cardiac protective effects of PAK1, as well as its role in maintaining ventricular Ca2+ homeostasis and electrophysiological stability under physiological, β-adrenergic and hypertrophic stress conditions.

关键词: p21-activated kinase 1 (PAK1)     heart    

Progressive failure analysis of notched composite plate by utilizing macro mechanics approach

《结构与土木工程前沿(英文)》 2021年 第15卷 第3期   页码 623-642 doi: 10.1007/s11709-021-0726-8

摘要: In this study, gradual and sudden reduction methods were combined to simulate a progressive failure in notched composite plates using a macro mechanics approach. Using the presented method, a progressive failure is simulated based on a linear softening law prior to a catastrophic failure, and thereafter, sudden reduction methods are employed for modeling a progressive failure. This combination method significantly reduces the computational cost and is also capable of simultaneously predicting the first and last ply failures (LPFs) in composite plates. The proposed method is intended to predict the first ply failure (FPF), LPF, and dominant failure modes of carbon/epoxy and glass/epoxy notched composite plates. In addition, the effects of mechanical properties and different stacking sequences on the propagation of damage in notched composite plates were studied. The results of the presented method were compared with experimental data previously reported in the literature. By comparing the numerical and experimental data, it is revealed that the proposed method can accurately simulate the failure propagation in notched composite plates at a low computational cost.

关键词: progressive failure     notched composite plate     Hashin failure criterion     macro mechanics approach     finite element method    

Bending failure performance of a shield tunnel segment based on full-scale test and numerical analysis

《结构与土木工程前沿(英文)》   页码 1033-1046 doi: 10.1007/s11709-023-0973-y

摘要: This study focuses on the bending failure performance of a shield tunnel segment. A full-scale test was conducted to investigate deformation and failure characteristics. During the loading, the bending failure process can be divided into four stages: the elastic stage, working stage with cracks, failure stage, and ultimate stage. The characteristic loads between contiguous stages are the cracking, failure, and ultimate loads. A numerical model corresponding to the test was established using the elastoplastic damage constitutive model of concrete. After a comparative analysis of the simulation and test results, parametric studies were performed to discuss the influence of the reinforcement ratio and proportion of tensile longitudinal reinforcement on the bearing capacity. The results indicated that the change in the reinforcement ratio and the proportion of tensile longitudinal reinforcement had little effect on the cracking load but significantly influenced the failure and ultimate loads of the segment. It is suggested that in the reinforcement design of the subway segment, the reinforcement ratio and the proportion of tensile longitudinal reinforcement can be chosen in the range of 0.7%–1.2% and 49%–55%, respectively, allowing the segment to effectively use the reinforcement and exert the design strength, thereby improving the bearing capacity of the segment.

关键词: shield tunnel     bearing capacity     failure mechanism     segment reinforcement    

Overview on acute-on-chronic liver failure

null

《医学前沿(英文)》 2016年 第10卷 第1期   页码 1-17 doi: 10.1007/s11684-016-0439-x

摘要:

Liver failure (LF) is defined as severe dysfunction in hepatic synthesis, detoxification, and metabolism induced by various etiologies. Clinical presentation of LF typically includes severe jaundice, coagulation disorder, hepatic encephalopathy, and ascites. LF can be classified into acute LF, acute-on-chronic LF (ACLF), and chronic LF. ACLF has been demonstrated as a distinct syndrome with unique clinical presentation and outcomes. The severity, curability, and reversibility of ACLF have attracted considerable attention. Remarkable developments in ACLF-related conception, diagnostic criteria, pathogenesis, and therapy have been achieved. However, this disease, especially its diagnostic criteria, remains controversial. In this paper, we systemically reviewed the current understanding of ACLF from its definition, etiology, pathophysiology, pathology, and clinical presentation to management by thoroughly comparing important findings between east and west countries, as well as those from other regions. We also discussed the controversies, challenges, and needs for future studies to promote the standardization and optimization of the diagnosis and treatment for ACLF.

关键词: liver failure     chronic liver failure     acute-on-chronic liver failure     diagnosis     prognosis     treatment    

Surficial stability analysis of soil slope under seepage based on a novel failure mode

《结构与土木工程前沿(英文)》 2021年 第15卷 第3期   页码 712-726 doi: 10.1007/s11709-021-0729-5

摘要: Normally, the edge effects of surficial landslides are not considered in the infinite slope method for surficial stability analysis of soil slopes. In this study, the limit stress state and discrimination equation of an infinite slope under saturated seepage flow were analyzed based on the Mohr-Coulomb strength criterion. Therefore, a novel failure mode involving three sliding zones (upper tension zone, middle shear sliding zone, and lower compression zone) was proposed. Accordingly, based on the limit equilibrium analysis, a semi-analytical framework considering the edge effect for the surficial stability of a soil slope under downslope seepage was established. Subsequently, the new failure mode was verified via a numerical finite element analysis based on the reduced strength theory with ABAQUS and some simplified methods using SLIDE software. The results obtained by the new failure mode agree well with those obtained by the numerical analysis and traditional simplified methods, and can be efficiently used to assess the surficial stability of soil slopes under rainwater seepage. Finally, an evaluation of the infinite slope method was performed using the semi-analytical method proposed in this study. The results show that the infinite slope tends to be conservative because the edge effect is neglected, particularly when the ratio of surficial slope length to depth is relatively small.

关键词: soil slope     seepage     surficial failure mode     stress state     edge effects    

LSSVM-based approach for refining soil failure criteria and calculating safety factor of slopes

Shiguo XIAO; Shaohong LI

《结构与土木工程前沿(英文)》 2022年 第16卷 第7期   页码 871-881 doi: 10.1007/s11709-022-0863-8

摘要: The failure criteria of practical soil mass are very complex, and have significant influence on the safety factor of slope stability. The Coulomb strength criterion and the power-law failure criterion are classically simplified. Each one has limited applicability owing to the noticeable difference between calculated predictions and actual results in some cases. In the work reported here, an analysis method based on the least square support vector machine (LSSVM), a machine learning model, is purposefully provided to establish a complex nonlinear failure criterion via iteration computation based on strength test data of the soil, which is of more extensive applicability to many problems of slope stability. In particular, three evaluation indexes including coefficient of determination, mean absolute percentage error, and mean square error indicate that fitting precision of the machine learning-based failure criterion is better than those of the linear Coulomb criterion and nonlinear power-law criterion. Based on the proposed LSSVM approach to determine the failure criterion, the limit equilibrium method can be used to calculate the safety factor of three-dimensional slope stability. Analysis of results of the safety factor of two three-dimensional homogeneous slopes shows that the maximum relative errors between the proposed approach and the linear failure criterion-based method and the power-law failure criterion-based method are about 12% and 7%, respectively.

关键词: slope stability     safety factor     failure criterion     least square support vector machine    

Study of high-strength CFRP bolted joints with failure- monitoring cone washers

Tsukasa KATSUMATA, Yoshihiro MIZUTANI, Akira TODOROKI, Ryosuke MATSUZAKI

《机械工程前沿(英文)》 2011年 第6卷 第3期   页码 272-276 doi: 10.1007/s11465-011-0231-1

摘要:

To increase the strength of carbon-fiber-reinforced plastic (CFRP) bolted joints, a method to increase the friction force between carbon-fiber-reinforced plastic members was proposed. The increase in failure load for the proposed joint was confirmed in finite-element method analyses and joint tests. Additionally, the feasibility of damage monitoring using surface strains of the cone washer was demonstrated.

关键词: composite     bolted joint     failure monitoring     finite-element method    

Analysis of stress and failure in rock specimens with closed and open flaws on the surface

《结构与土木工程前沿(英文)》 2021年 第15卷 第5期   页码 1222-1237 doi: 10.1007/s11709-021-0773-1

摘要: The influence of closed and open surface flaws on the stress distribution and failure in rock specimens is investigated. Heterogeneous finite element models are developed to simulate the compression tests on flawed rock specimens. The simulated specimens include those with closed flaws and those with open flaws on the surface. Systematic analyses are conducted to investigate the influences of the flaw inclination, friction coefficient and the confining stress on failure behavior. Numerical results show significant differences in the stress, displacement, and failure behavior of the closed and open flaws when they are subjected to pure compression; however, their behaviors under shear and tensile loads are similar. According to the results, when compression is the dominant mode of stress applied to the flaw surface, an open flaw may play a destressing role in the rock and relocate the stress concentration and failure zones. The presented results in this article suggest that failure at the rock surface may be managed in a favorable manner by fabricating open flaws on the rock surface. The insights gained from this research can be helpful in managing failure at the boundaries of rock structures.

关键词: surface flaw     heterogeneity     circular hole     numerical modeling     relative displacement    

标题 作者 时间 类型 操作

Integrated management of cardiac failure: the cardiac failure clinic

null

期刊论文

Distinct mononuclear diploid cardiac subpopulation with minimal cell–cell communications persists in

期刊论文

Association of cardiac disease with the risk of post-lung transplantation mortality in Chinese recipients

期刊论文

Management of mantle cell leukemia with cardiac involvement leading to cardiogenic shock

null

期刊论文

Effects of RNA interference targeting angiotensin 1a receptor on blood pressure and cardiac hypertrophy

ZHANG Jingqun, SUN Honglei, MA Yexin, WANG Daowen

期刊论文

Chronic inhibition of cyclic guanosine monophosphate-specific phosphodiesterase 5 prevented cardiac fibrosis

null

期刊论文

Acetyl salicylic acid attenuates cardiac hypertrophy through Wnt signaling

null

期刊论文

PAK1 is a novel cardiac protective signaling molecule

null

期刊论文

Progressive failure analysis of notched composite plate by utilizing macro mechanics approach

期刊论文

Bending failure performance of a shield tunnel segment based on full-scale test and numerical analysis

期刊论文

Overview on acute-on-chronic liver failure

null

期刊论文

Surficial stability analysis of soil slope under seepage based on a novel failure mode

期刊论文

LSSVM-based approach for refining soil failure criteria and calculating safety factor of slopes

Shiguo XIAO; Shaohong LI

期刊论文

Study of high-strength CFRP bolted joints with failure- monitoring cone washers

Tsukasa KATSUMATA, Yoshihiro MIZUTANI, Akira TODOROKI, Ryosuke MATSUZAKI

期刊论文

Analysis of stress and failure in rock specimens with closed and open flaws on the surface

期刊论文