ISSN:1015-9770    

DOI:10.1159/000108741

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Smooth muscle cells (SMCs) implicated in the human atheromatous process show dedifferentiated features characterized by typical changes in cytoskeletal elements. In the normal media, quiescent SMCs express predominantly the α-smooth muscle (SM) actin isoform. In the human atheromatous plaque and in rat experimental intimal thickening 15 days after balloon-induced endothelial injury, a decrease in the α-SM actin isoform and a predominance of the β-cytoplasmic actin isoform develop. Thus, the study of cytoskeletal changes enables a better definition of SMC phenotype. Furthermore, in vitro SMCs may represent a useful experimental model to study phenotypic modifications of SMCs during pathological process. Cytokines and growth factors, released by cells present in the atheromatous plaque, and extracellular components of the arterial wall, such as heparin, modulate the expression of α-SM actin in cultured SMCs and represent good candidates to exert important regulatory actions in vivo. Clones of aortic SMC derived from rats of different ages show different phenotypic features. A better understanding of the mechanisms leading to cytoskeletal modifications may help in the clarification of the mechanisms playing a role in the development of arterial pathological eve

ISSN:1015-9770    

DOI:10.1159/000108742

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Vascular dementia is growing in importance, so is the confusion surrounding it. Vascular dementia may be regarded as a syndrome of cognitive impairment resulting from vascular diseases, especially ischemic brain changes. It may be related to many different vascular mechanisms, types of brain changes and risk factors. However, currently no precise knowledge exists regarding the extent to which these factors cause, contribute or only coincide with the cognitive loss. The resulting imprecision in definition and diagnosis breeds confusion regarding prevention, treatment and incidence of the syndrome. In addition, the changing patterns of age of the population, risk factors and types of stroke complicate the clinical picture. Instead of comfortable categorization, the emphasis needs to be shifted to identifying and understanding the interactive vascular factors that contribute to cognitive impairment. This may open avenues in the search for modifiable and treatable vascular components.

ISSN:1015-9770    

DOI:10.1159/000108661

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Identification of precursors of stroke is the first step in instituting a program for disease prevention. These precursors include risk factors: hypertension, diabetes, cigarette smoking, left ventricular hypertrophy by ECG, as well as predisposing diseases: coronary heart disease, cardiac failure and atrial fibrillation. Two preventive approaches may be taken: one is a public health approach whereby the entire population is informed of the dangers of certain highly prevalent risk factors for disease: antismoking and hypertension awareness campaigns and the current United States National Cholesterol Education Program are examples of this approach; the other is more focused and requires treatment by physicians of individuals found to be at increased risk of stroke. For the public health approach to be feasible, the risk factor under attack needs to be prevalent in the population and potent as a disease promotor. For precursors occurring infrequently in the population but with a high relative risk, or where the multiple borderline levels of risk factors are present, treatment of high risk individuals is in order. Use of the stroke risk function enables the treating physician to determine the conditional probability of stroke in the individual patient. The individual''s risk of stroke can be compared to that of an average person of the same age and sex and has been shown to be useful in predicting stroke recurrence and death.

ISSN:1015-9770    

DOI:10.1159/000108743

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Aspirin is effective in reducing vascular outcomes in patients with atherosclerosis, with a relative risk reduction of about 30% for stroke, 22% for stroke and death and 15% for vascular mortality. Apparently 900 and 1,300 mg aspirin are similar in efficacy. Whether low dose aspirin, such as 75 or 30 mg/day, is as effective in preventing strokes is less certain. Complications of high dose aspirin are more frequent than with low doses. The Ticlopidine Aspirin Stroke Study showed, in the 1st year, a 42% risk reduction for stroke and death and a 47% risk reduction for stroke and stroke death. The superiority of ticlopidine in the reduction in strokes was seen in both males and females. Save for a reversible severe neutropenia in 0.9% of patients on ticlopidine, side effects related to ticlopidine were relatively benign and reversible. The Canadian American Ticlopidine Study compared ticlopidine to placebo in patients with completed major strokes. The primary outcome cluster of stroke, myocardial infarction and vascular death showed a risk reduction of about 30% in the ticlopidine group, providing strong evidence that ticlopidine conveys a clinically important reduction in the risk of thromboembolic events in patients with a history of completed thromboembolic stroke. In conclusion, aspirin is effective in preventing stroke, myocardial infarction and death from vascular causes. Ticlopidine is more effective than aspirin in preventing stroke. The modest, reversible risk of neutropenia, affecting less than 1 % of patients, makes the benefit-risk ratio a reasonable one. Meta-analysis of pooled antiplatelet stroke prevention trials and antiplatelet studies in other indications add statistical strength to these observations and yield important new inferences in subgroups of risk, which show the way for improved prevention of the individual patient and for more focused prevention trials in the future.

ISSN:1015-9770    

DOI:10.1159/000108744

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

All aspects of stroke management are best considered within the World Health Organisation''s framework of illness, which acknowledges four levels: pathology; impairment; disability, and handicap. Prevention ultimately aims to prevent death and minimise handicap. It may be targeted at pathology, preventing cerebral infarction; impairment, preventing symptoms and signs; disability, minimising dependence, or handicap, maximising freedom within society. The risk of recurrence of symptomatic stroke is relatively low (10%/year) and the reduction in risk achievable is only modest (20% reduction). Consequently, it is always necessary to balance the risks of intervention, and the costs (e.g. in terms of reduced pleasure or increased anxiety) against the potential benefit. In severely dependent people, it is unlikely that intervention is warranted.

ISSN:1015-9770    

DOI:10.1159/000108745

出版商:S. Karger AG    

年代:1993

数据来源: Karger

ISSN:1015-9770    

DOI:10.1159/000108663

出版商:S. Karger AG    

年代:1993

数据来源: Karger

ISSN:1015-9770    

DOI:10.1159/000108664

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

A group of 30 patients with symptomatic internal carotid artery (ICA) occlusion and different computed tomography (CT) patterns of cerebral ischemia (14 borderzone and/or terminal, 16 territorial) were studied by means of transcranial Doppler (TCD) to determine the relationship between vasomotor reactivity and the topography of the infarct on CT scan. The vasomotor reactivity was evaluated by assessing the mean flow velocity changes observed in the middle cerebral artery (MCA) after the longest possible apnea and i.v. Diamox injection (12–15 mg/kg body weight). An impairment in the vasomotor response was found in 13 out of 14 patients with borderzone and/or terminal ischemia but in only 1 out of 16 with complete territorial ischemia. No relationship with the basal MCA flow velocity was observed. Diamox and apnea tests in TCD examination can be considered useful tools for investigating the hemodynamic changes following ICA occlusion.

ISSN:1015-9770    

DOI:10.1159/000108665

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The ultimate goal of biomedical research is the promotion of health and the prevention of disease and disability. We are indeed fortunate that preventive measures for stroke are now available and applicable; also, important additional strategies are being actively explored. Future studies of stroke prevention need to address three aspects of the stroke syndrome: (1) the prevention of the initial episode; (2) the prevention of brain cell destruction during the acute period, and (3) the prevention or reduction of cognitive and physical deficits as a consequence of cell death. The economic and social impact of stroke is difficult to evaluate. In the past, the usual economic estimates were based on the cost of long-term disability. Today, with methods of early intervention now available, the cost of acute medical and surgical care, as well as long-term consequences, need to be included.

ISSN:1015-9770    

DOI:10.1159/000108746

出版商:S. Karger AG    

年代:1993

数据来源: Karger