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Biomedical subjects

Paul Erne

Publications and source records attributed to Paul Erne.

33 records · Page 2Linked to original sources
PubMed2004

Cell adhesion molecule T-cadherin regulates vascular cell adhesion, phenotype and motility.

T-cadherin (T-cad), an unusual glycosylphosphatidylinositol (GPI)-anchored member of the cadherin family of cell adhesion molecules, is widely expressed in the cardiovascular system. The expression profile of T-cad within diseased (atherosclerotic and restenotic) vessels indicates some relationship between expression of T-cad and the phenotypic status of resident cells. Using cultures of human aortic smooth muscle cells (SMC) and human umbilical vein endothelial cells (HUVEC) we investigate the hypothesis that T-cad may function in modulating adhesive properties of vascular cells. Coating of culture plates with recombinant T-cad protein or with antibody against the first amino-terminal domain of T-cad (anti-EC1) significantly decreased adhesion and spreading of SMC and HUVEC. HUVECs adherent on T-cad or anti-EC1 substratum exhibited an elongated morphology and associated redistribution of the cytoskeleton and focal adhesions to a distinctly peripheral location. These changes are characteristic of the less-adhesive, motile or pro-migratory, pro-angiogenic phenotype. Boyden chamber migration assay demonstrated that the deadhesion induced by T-cad facilitates cell migration towards a serum gradient. Overexpression of T-cad in vascular cells using adenoviral vectors does not influence cell adhesion or motility per se, but increases the detachment and migratory responses induced by T-cad substratum. The data suggest that T-cad acts as an anti-adhesive signal for vascular cells, thus modulating vascular cell phenotype and migration properties.

Antibodies↗
PubMed2004

Cost-effectiveness of losartan versus atenolol in treating hypertension--an analysis of the LIFE study from a Swiss perspective.

AIMS: To determine the economic benefit of losartan versus atenolol in patients with essential hypertension from the perspective of the Swiss healthcare system. METHODS AND RESULTS: The cost-effectiveness of losartan versus atenolol in the treatment of hypertension was analyzed by applying the results of the LIFE study to the Swiss healthcare system using a decision analysis framework. The cost-effectiveness shows the losartan cohort to provide an additional life expectancy of 0.05 years per patient compared to the atenolol cohort, over a mean follow-up period of 4.8 years. Losartan therapy in hypertensive patients produced net cost savings of CHF 24 per patient and per 4.8 years compared to atenolol from the perspective of the Swiss health care system. This result was robust after varying costs of medication, stroke, myocardial infarction and life expectancy. CONCLUSION: The use of a losartan-based regimen in hypertensive patients with left ventricular hypertrophy in Switzerland is net cost-saving compared with a atenolol-based regimen.

Aged↗
PubMed2004

Risks and benefits of optimised medical and revascularisation therapy in elderly patients with angina--on-treatment analysis of the TIME trial.

AIM: To assess treatment effects of optimised medical therapy and PCI or CABG surgery on one-year outcome in patients 75 years old with chronic angina. METHODS AND RESULTS: On-treatment analysis of the TIME data: all re-vascularised patients (REVASC n=174: 112 randomised to revascularisation and 62 to drugs with late revascularisation) were compared to all patients on continued drug therapy (MED n=127: 86 randomised to drugs and 41 to revascularisation only). Baseline characteristics of both groups were similar (age 80 +/- 4 years). Risk of death at one year (adjusted hazard ratio (HR)=1.31; 95%-CI: 0.58-2.99; P=0.52) and of death/infarction (adjusted hazard RATIO=1.77; 95%-CI 0.91-3.41; P=0.09) were comparable between REVASC and MED patients. Furthermore, the risk of death within 30 days was even slightly lower among REVASC patients (unadjusted hazard RATIO=0.73; 95%-CI: 0.21-2.53; P=0.98). Overall, REVASC patients had greater improvements in symptoms and well-being than MED patients (P<0.01). Surgical patients had similar mortality rates as angioplasty patients, but they also had greater symptomatic improvements (P<0.01). CONCLUSION: Treated medically, elderly patients with chronic angina have a similarly high 30-day and one-year mortality as patients of the same age being re-vascularised; however, they can expect lower improvements in symptoms and well being.

Aged↗
PubMed2004

The calcium channel blocker amlodipine exerts its anti-proliferative action via p21(Waf1/Cip1) gene activation.

Proliferation of vascular smooth muscle cells (VSMC) contributes to the progression of atherosclerotic plaques. Calcium channel blockers have been shown to reduce VSMC proliferation, but the underlying molecular mechanism remains unclear. p21(Waf1/Cip1) is a potent inhibitor of cell cycle progression. Here, we demonstrate that amlodipine (10(-6) to 10(-8) M) activates de novo synthesis of p21(Waf1/Cip1) in vitro. We show that amlodipine-dependent activation of p21(Waf1/Cip1) involves the action of the glucocorticoid receptor (GR) and C/EBP-alpha. The underlying pathway apparently involves the action of mitogen-activated protein kinase or protein kinase C, but not of extracellular signal-related kinase or changes of intracellular calcium. Amlodipine-induced p21(Waf1/Cip1) promoter activity and expression were abrogated by C/EBP-alpha antisense oligonucleotide or by the GR antagonist RU486. Amlodipine-dependent inhibition of cell proliferation was partially reversed by RU486 at 10(-8) M (58%+/-29%), antisense oligonucleotides targeting C/EBP-alpha (91%+/-26%), or antisense mRNAs targeting p21(Waf1/Cip1) (96%+/-32%, n=6); scrambled antisense oligonucleotides or those directed against C/EBP-beta were ineffective. The data suggest that the anti-proliferative action of amlodipine is achieved by induction of the p21 (Waf1/Cip1) gene, which may explain beneficial covert effects of this widely used cardiovascular therapeutic drug beyond a more limited role as a vascular relaxant.

Amlodipine↗
PubMed2003

Polarisation of T-cadherin to the leading edge of migrating vascular cells in vitro: a function in vascular cell motility?

Both histological and in vitro studies indicate a relationship between T-cadherin levels and acquisition of a modulated, migratory phenotype by vascular cells. This study further examines a role for T-cadherin in relation to cell migration and adhesion. Fluorescence microscopic examination of T-cadherin localisation in confluent cultures of human umbilical vein endothelial cells (HUVEC), human aortic smooth muscle cells and the human carcinoma cell line ECV-304 revealed global distribution over the entire cell body, and with only slight enrichment at cell borders. This contrasts with restricted cell-cell junction localisation of classical cadherin (for example, VE-cadherin in HUVEC). In wounded cultures, T-cadherin polarised to the leading edge of cells migrating into the wound area, again contrasting with classical VE-cadherin, which was undetectable in this region. Confocal microscopy demonstrated that potential signalling functions of T-cadherin at the leading edge are unrelated to physical interactions with caveolin. Adherence of HUVEC onto a monolayer of T-cadherin-transfected L929 cells is significantly reduced compared with adhesion onto control (T-cadherin-negative) L929. Thus T-cadherin is not required for maintenance of intercellular adhesion, but may rather function as a signalling molecule involved in cell-cell recognition and sensing of the environment in processes where cell detachment occurs.

Cadherins↗
PubMed2003

Ca2+ -dependent interaction of S100A1 with the sarcoplasmic reticulum Ca2+ -ATPase2a and phospholamban in the human heart.

The Ca(2+)-binding S100A1 protein displays a specific and high expression level in the human myocardium and is considered to be an important regulator of heart contractility. Diminished protein levels detected in dilated cardiomyopathy possibly contribute to impaired Ca(2+) handling and contractility in heart failure. To elucidate the S100A1 signaling pathway in the human heart, we searched for S100A1 target proteins by applying S100A1-specific affinity chromatography and immunoprecipitation techniques. We detected the formation of a Ca(2+)-dependent complex of S100A1 with SERCA2a and PLB in the human myocardium. Using confocal laser scanning microscopy, we showed that all three proteins co-localize at the level of the SR in primary mouse cardiomyocytes and confirmed these results by immunoelectron microscopy in human biopsies. Our results support a regulatory role of S100A1 in the contraction-relaxation cycle in the human heart.

Animals↗
PubMed2003

Outcome of elderly patients with chronic symptomatic coronary artery disease with an invasive vs optimized medical treatment strategy: one-year results of the randomized TIME trial.

CONTEXT: The risk-benefit ratio of invasive vs medical management of elderly patients with symptomatic chronic coronary artery disease (CAD) is unclear. The Trial of Invasive versus Medical therapy in Elderly patients (TIME) recently showed early benefits in quality of life from invasive therapy in patients aged 75 years or older, although with a certain excess in mortality. OBJECTIVE: To assess the long-term value of invasive vs medical management of chronic CAD in elderly adults in terms of quality of life and prevention of major adverse cardiac events. DESIGN: One-year follow-up analysis of TIME, a prospective randomized trial with enrollment between February 1996 and November 2000. SETTING AND PARTICIPANTS: A total of 282 patients with Canadian Cardiac Society class 2 or higher angina despite treatment with 2 or more anti-anginal drugs who survived for the first 6 months after enrollment in TIME (mean age, 80 years [range, 75-91 years]; 42% women), enrolled at 14 centers in Switzerland. INTERVENTIONS: Participants were randomly assigned to undergo coronary angiography followed by revascularization (if feasible) (n = 140 surviving 6 months) or to receive optimized medical therapy (n = 142 surviving 6 months). MAIN OUTCOME MEASURES: Quality of life, assessed by standardized questionnaire; major adverse cardiac events (death, nonfatal myocardial infarction, or hospitalization for acute coronary syndrome) after 1 year. RESULTS: After 1 year, improvements in angina and quality of life persisted for both therapies compared with baseline, but the early difference favoring invasive therapy disappeared. Among invasive therapy patients, later hospitalization with revascularization was much less likely (10% vs 46%; hazard ratio [HR], 0.19; 95% confidence interval [CI], 0.11-0.32; P<.001). However, 1-year mortality (11.1% for invasive; 8.1% for medical; HR, 1.51; 95% CI, 0.72-3.16; P =.28) and death or nonfatal myocardial infarction rates (17.0% for invasive; 19.6% for medical; HR, 0.90; 95% CI, 0.53-1.53; P =.71) were not significantly different. Overall major adverse cardiac event rates were higher for medical patients after 6 months (49.3% vs 19.0% for invasive; P<.001), a difference which increased to 64.2% vs 25.5% after 12 months (P<.001). CONCLUSIONS: In contrast with differences in early results, 1-year outcomes in elderly patients with chronic angina are similar with regard to symptoms, quality of life, and death or nonfatal infarction with invasive vs optimized medical strategies based on this intention-to-treat analysis. The invasive approach carries an early intervention risk, while medical management poses an almost 50% chance of later hospitalization and revascularization.

Aged↗
PubMed2003

Aryl hydrocarbon receptor ligands repress T-cadherin expression in vascular smooth muscle cells.

T-cadherin, a glycosylphosphatidylinositol-modified cadherin subtype, is highly expressed in cardiac and vascular tissues. Neither the functions nor regulation of T-cadherin in these tissues is understood. We have cloned rat T-cadherin cDNA encoding the full length amino acid sequence. The 5(') untranslated nucleotide sequences of rat, mouse, and human T-cadherin contain a conserved GCGTG motif which constitutes the invariant core sequence of dioxin- or xenobiotic-regulatory elements. These elements function as target sites for aryl hydrocarbon receptor/aryl hydrocarbon nuclear translocator (AhR/ARNT) in genes regulated by this transcription factor. Using cultures of rat aortic smooth muscle cells this study presents data revealing T-cadherin as a putative target gene for negative regulation of expression through AHR signalling. Prototypic AHR agonists benzo[a]pyrene (BaP) or 7,12-dimethylbenzanthracene (DMBA) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) repressed T-cadherin mRNA levels. Repression was antagonized by the cognate AHR antagonist alpha-naphthoflavone (alpha-NF). Repression was insensitive to inhibitors of gene transcription (actinomycin D) or de novo protein synthesis (cycloheximide), suggesting AHR/ARNT functions directly in transcriptional repression of T-cad. Regulation of adhesion proteins through the AHR pathway may represent a novel mechanism of action by atherogenic polycyclic aromatic hydrocarbons.

5' Untranslated Regions↗
PubMed2002

Expression of adhesion molecule T-cadherin is increased during neointima formation in experimental restenosis.

Phenotypic modulation, migration and proliferation of vascular smooth muscle cells (SMCs) are major events in restenosis after percutaneous transluminal angioplasty. Surface cell adhesion molecules, essential to morphogenesis and maintenance of adult tissue architecture, are likely to be involved, but little is known about cell adhesion molecules expressed on SMCs. T-cadherin is a glycosyl phosphatidylinositol-anchored member of the cadherin superfamily of adhesion molecules. Although highly expressed in vascular and cardiac tissues, its function in these tissues is unknown. We previously reported increased expression of T-cadherin in intimal SMCs in atherosclerotic lesions and proposed a role for T-cadherin in phenotype control. Here we performed immunohistochemical analysis of spatial and temporal changes in vascular T-cadherin expression following balloon catheterisation of the rat carotid artery. T-cadherin expression in SMCs markedly increases in the media early (1-4 days) after injury, and later (day 7-28) in forming neointima, especially in its preluminal area. Staining for monocyte/macrophage antigen ED-1, proliferating cell nuclear antigen and smooth muscle alpha-actin revealed that spatial and temporal changes in T-cadherin level coincided with the peak in cell migration and proliferation activity during neointima formation. In colchicine-treated cultures of rat aortic SMCs T-cadherin expression is increased in dividing M-phase cells but decreased in non-dividing cells. Together the data support an association between T-cadherin expression and SMC phenotype.

Angioplasty, Balloon↗
PubMed2002

The economic efficiency of amlodipine in the treatment of coronary atherosclerosis--an analysis based on the PREVENT study.

BACKGROUND: High health service expenditure on the one hand, and the politically declared objective of stability of statutory contributions and restriction of public funds on the other hand, have been central points of the political and social discussion for several years. The over-proportional increase in health service expenditure is obvious, compared to the increase in the costs of living. PATIENTS AND METHODS: Cost-effectiveness of amlodipine in the treatment of coronary atherosclerosis was analysed by applying the results of the PREVENT study to the Swiss health system. RESULTS: Calculation of effectiveness shows an additional life expectancy of 0.083 years in the amlodipine cohort compared to the placebo cohort, over an observation period of 3 years. The cost-effectiveness of amlodipine treatment is approximately CHF 14,650 per life-year gained. CONCLUSION: The administration of the calcium antagonist amlodipine in CHD patients is cost-effective.

Amlodipine↗
PubMed1997

Age-Dependent Prevalence of Cardioembolic Sources Detected by TEE: Diagnostic and Therapeutic Implications.

To define the prevalence of cardioembolic sources found by transesophageal echocardiography (TEE) in different age groups of patients with and without cryptogenic systemic embolism, TEE risk factors for cardiogenic embolism were identified from 341 consecutive patients referred for TEE. One hundred and thirty-five had cryptogenic cerebral or systemic peripheral embolic events (CEE) and 206 other indications for TEE (CTR). Cardioembolic sources were found in 40% of CEE and in 29% of CTR (P < 0.02). Specifically, left atrial (LA) thrombi (P < 0.0001), atrial septal aneurysm with right-to-left shunt (P < 0.002), and atherosclerotic aortic plaques (P < 0.02) were more frequent. The prevalence of potential cardioembolic sources was significantly higher in patients >/= 70-years old than in younger patients (P < 0.03), specifically LA thrombi (P < 0.004) and atherosclerotic aortic plaques (P < 0.0001). In patients >/= 70-years old, potential cardioembolic sources were found in 63% and in 40% in CEE and CTR (P = 0.073), respectively. However, LA thrombi were more frequent in CEE (P < 0.003). Thus, potential cardioembolic sources observed by TEE are found more frequently in patients >/= 70-years old than in younger patients. LA thrombi were more frequent in CEE than in CTR patients >/= 70-years old. In patients >/= 70-years old with CEE who are eligible for an anticoagulant regimen, a search for potential cardioembolic sources by TEE should be considered.

Journal Article↗
PubMedDate not supplied

The road to bioabsorbable stents: reaching clinical reality?

This article provides an overview of the evolution of revascularization devices since Grüntzig's initial introduction of balloon angioplasty in 1977. In-stent restenosis (ISR) is the major shortcoming of conventional (permanent-implant) stent therapy; even with the innovation and promising benefits of drug-eluting stents, management of ISR is very difficult. ISR is mainly caused by the interaction between the blood and the stent surface and a permanent mechanical irritation of the vascular tissue. Thus stenting technology has moved toward the development of temporary implants composed of biocompatible materials which mechanically support the vessel during the period of high risk for recoil and then completely biodegrade in the long term. Preclinical and first clinical experiences with bioabsorbable magnesium stents are discussed.

Absorbable Implants↗
PubMedDate not supplied

Acoustic cardiographic parameters and their relationship to invasive hemodynamic measurements in patients with left ventricular systolic dysfunction.

Data obtained at cardiac catheterization were used to evaluate the utility of acoustic cardiographic data in assessing the hemodynamic abnormalities associated with left ventricular systolic dysfunction (LVSD). Thirty-seven patients (mean age, 62.6 years) underwent catheterization, and hemodynamic data were recorded. Acoustic cardiographic recordings were obtained using a system that records and algorithmically interprets diastolic heart sounds and parameters analogous to traditional systolic time intervals. Seventeen patients had LVSD (defined as ejection fraction <50%). The 17 patients with LVSD composed the cohort for analysis. There were strong associations between acoustic cardiographic parameters and left ventricular end-diastolic pressure, ejection fraction, and maximum contractility. Heart rate tended to influence the strength of these correlations. The authors conclude that acoustic cardiographic data can be used in the evaluation of patients with known or suspected LVSD, and specifically in the selection of patients for cardiac resynchronization therapy and the optimization of the settings of implanted resynchronization devices.

Acoustics↗