Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We evaluated platelet accumulation in carotid arteries by means of a dual-radiotracer method, using indium-111-labeled platelets and technetium-99m-labeled human serum albumin, in 123 patients (92 men, 31 women; median age 60 years). Sixty patients had symptoms of transient ischemic carotid artery disease, and 63 patients with peripheral arterial occlusive disease served as controls. Antiplatelet treatment with acetylsalicylic acid was taken by 53 of the 123 patients. In 36 of the 60 symptomatic patients, platelet scintigraphy was repeated 3-4 days after carotid endarterectomy. Comparison of different scintigraphic parameters (platelet accumulation index and percent of the injected dose of labeled platelets at the carotid bifurcation) showed no significant differences between symptomatic and asymptomatic patients, and the severity of stenosis and the presence of plaque ulceration also had no influence on the parameters. There was no difference between patients with a short (less than 4 weeks) or long (greater than 4 weeks) interval from the last transient ischemic attack to scintigraphy and no difference between patients with or without antiplatelet treatment. Classifying the patients according to plaque morphology judged by high-resolution real-time ultrasonography also demonstrated no differences. No significant correlation was found between any scintigraphic parameter and other platelet function parameters such as platelet survival time, platelet turnover rate, and concentration of platelet-specific proteins. Quantification of platelet deposition after carotid endarterectomy in 36 patients demonstrated a significant increase of the median platelet accumulation index and the percent injected dose index. There were no significant differences between patients receiving high-dose (1.0 g/day) or low-dose (1.0 g/day) acetylsalicylic acid in scintigraphic results.(ABSTRACT TRUNCATED AT 250 WORDS)
Stroke 1989 Jan
PMID:Indium-111-labeled platelet scintigraphy in carotid atherosclerosis. 291 31

A prospective study was conducted of 82 carotid endarterectomy plaques from 73 patients to determine the incidence of intraplaque hemorrhage, its relation to the production of cerebral ischemic symptoms, and the role of the antiplatelets. These included 42 with hemispheric transient ischemic attacks (TIA), nine with hemispheric stroke (Group A), and 31 with nonhemispheric TIA's or asymptomatic carotid stenosis (Group B). The plaques were evaluated for the presence of hemorrhage. Intraplaque hemorrhage was present in 63 (76.8%) of 82; 46 (90.2%) of 51 in Group A had hemorrhage, in contrast to 17 (54.8%) of 31 in Group B (P less than .001). Twenty-nine (56.86%) plaques from patients in Group A had multiple hemorrhages and 22 (43.14%) had single or no hemorrhages; in contrast to two (6.45%) that had multiple hemorrhages and 29 (93.55%) that had single or no hemorrhages in patients in Group B (P less than .0005). Forty-seven plaques were removed from patients receiving antiplatelets; 43 (91.48%) of these showed hemorrhages. Of the 35 plaques that were removed from patients not receiving antiplatelets, 26 (74.2%) showed hemorrhages (P = .071). However, when the plaques were studied for multiple hemorrhages, 28 (59.5%) of 47 had multiple hemorrhages in patients receiving antiplatelet agents in contrast to 3 (8.57%) of 35 in patients receiving antiplatelet agents (P less than .00001). The authors conclude that 1) the intraplaque hemorrhage is an important and common feature in symptomatic carotid disease, 2) antiplatelets increase the incidence of plaque hemorrhages, particularly multiple hemorrhages that carry higher incidence of symptoms. Therefore the use of antiplatelet agents in certain patients with carotid artery disease is questioned.
 ...
PMID:Prospective clinicopathologic study of carotid intraplague hemorrhage. 291 42

To determine the incidence of perioperative silent cerebral infarction, 97 patients who underwent carotid endarterectomy were prospectively studied with preoperative and postoperative computed tomograms. Thirty-one of 96 patients (32%) had findings of cerebral infarction on preoperative computed tomograms. Silent cerebral infarction was found preoperatively in 17 patients (18%) (lacunar infarction in 10, cortical infarction in five, both cortical and lacunar infarctions in one, and cerebellar infarction in one). Transient ischemic attacks occurred in 10 of the 17 patients with silent cerebral infarction; however, symptoms were appropriate to the site in only five of these 10 patients. Fourteen of the 17 patients with silent cerebral infarction had a hemodynamically significant carotid stenosis, and seven patients had an ulcerated plaque on preoperative angiogram. The incidence of these lesions was similar to that found in the group of 66 patients without cerebral infarction. Endarterectomy specimens revealed a higher but not significantly different incidence of ulcerated plaque in the silent cerebral infarction group. There were no perioperative deaths. Following surgery, one patient (1%) with a preoperative silent cerebral infarction suffered a transient ischemic attack, and two patients (2%) with normal preoperative computed tomograms developed permanent neurologic deficits with new cortical infarctions on postoperative computed tomograms. No new silent cerebral infarctions were found on postoperative computed tomograms in any of the 97 patients. Our data suggest that silent cerebral infarction is a common preoperative finding with an as-yet unclear etiology and that carotid endarterectomy does not appear to be a cause.
Stroke 1989 Mar
PMID:Prospective analysis of carotid endarterectomy and silent cerebral infarction in 97 patients. 292 70

Cerebral amyloid angiopathy (CAA) refers to a group of hereditary (hereditary cerebral hemorrhage with amyloidosis, HCHWA and sporadic (SCAA) disorders characterized by amyloid fibril deposition restricted to the leptomeningeal and cortical vasculature leading to recurrent hemorrhagic and/or ischemic accidents. On clinical and biochemical grounds, two forms of HCHWA can be distinguished. The amyloid subunit of the HCHWA of Icelandic origin is related to Cystatin C, while amyloid from patients of Dutch origin (HCHWA-D) is related to the beta-protein (or A4), the main component of vascular and plaque core amyloid in Alzheimer's disease (AD) and Down's syndrome (DS) [corrected]. SCAA is an increasingly recognized cause of stroke in normotensive individual amounting to 5-10% of all cerebrovascular accidents. We now report the isolation and partial amino acid sequence of the amyloid subunit from a case of SCAA and a new case of HCHWA-D. The recognition that a heterogeneous group of diseases are linked by similar pathological and chemical features suggests that diversity of etiological factors may promote a common pathogenetic mechanism leading to amyloid-beta (A beta) deposition, and open new ways of research in AD and CAA as they are related to dementia and stroke.
 ...
PMID:Beta-protein deposition: a pathogenetic link between Alzheimer's disease and cerebral amyloid angiopathies. 305 68

Carotid Doppler is an accurate, safe and repeatable method of assessing arterial calibre, for distinguishing harmless neck bruits and to identify the stroke prone individual. It is completely non-invasive and can be used serially to monitor progression in carotid stenosis. It is a valuable clinical tool in diagnosis and management in patients at risk of stroke, but has definite limitations, such as in differentiating carotid occlusion from severe stenosis. B-mode imaging, although valuable in identifying arterial anatomy, and detecting plaques, cannot accurately evaluate the degree of stenosis. It is of limited value in identifying plaque hemorrhage and ulceration. Doppler ultrasound technology has advanced rapidly in the last decade, especially in the combination of B-mode imaging and Doppler (Duplex), as well as in evaluating of the intracranial circulation (transcranial Doppler). In the next decade, it may become the new gold standard for evaluating the extracranial and intracranial circulation.
 ...
PMID:The value of carotid Doppler ultrasound in asymptomatic extracranial arterial disease. 306 31

A spectrum of asymptomatic patients with carotid bifurcation disease exists, with varying degrees of risk for each sub-group. With Duplex scanning we studied the carotid arteries of several asymptomatic populations: volunteers at a health fair, patients referred to our vascular laboratory because of cervical bruits or associated vascular disease, and the contralateral asymptomatic vessels in those patients who had previously undergone endarterectomy. Volunteers had an extremely low incidence of carotid disease, possibly reflecting a bias of more healthy individuals attending a health fair. The contralateral asymptomatic vessels and vessels in the hospital asymptomatic group both had similar disease, with mainly fibrous or calcific plaques. Occurrence of new carotid territory symptoms was low in each hospital group. However, there were more strokes in the territory of the contralateral asymptomatic vessels, suggesting a greater risk for these patients. Symptomatic vessels tend to have plaques that are heterogeneous and echolucent. Change in plaque morphology may eventually become the best predictor of stroke risk, but longer follow-up studies of plaque progression are needed. In the meantime, the characteristics of asymptomatic populations in carotid artery studies must be carefully defined.
 ...
PMID:The spectrum of carotid artery disease in asymptomatic patients. 306 8

Patients with diabetes mellitus are more prone to stroke than non-diabetic patients. Using Duplex ultrasound imaging of the carotid bifurcation, we have found it possible to classify atherosclerotic plaques into four groups which appear to reflect the plaque pathology. Using this classification we have found that diabetics and non-diabetics have similar ultrasound plaque type distributions in symptomatic patients. Further subdivision of the diabetic patients on the basis of their mode of diabetic control has shown that insulin treated diabetics tend to show little evidence of intraplaque haemorrhage and ulceration. These features suggest that factors other than atherosclerosis at the carotid bifurcation may be responsible for the increased stroke risk in diabetic patients. Diabetic microangiopathy and reduced vessel compliance due to medial calcification have been suggested as possible factors. Insulin treatment of diabetics may protect against the development of occlusive atherosclerosis.
 ...
PMID:Carotid artery disease: the influence of diabetes mellitus. 306 9

Carotid endarterectomy is a controversial procedure. Despite the increasing incidence of its performance, there have been as yet no prospective randomised trials which have conclusively shown its benefits for patients with carotid artery atherosclerosis. Until the results of such studies become available, a rational approach to the estimation of stroke risk in these patients can be based on an understanding of their carotid plaque morphology. Over the past 4 years we have examined plaque morphology with a B-mode duplex scanner and have been able to categorise the degree of heterogeneity of plaques into 4 types depending on the degree of plaque echolucency. We have shown good correlation between the preoperative plaque type and the operation specimen. Furthermore, we have found that the risk of symptom development correlates with the development of a more echolucent plaque. Finally, while plaque heterogeneity may be a good predictor of the risk of embolism from the plaque, other deleterious factors such as hypertension may determine the severity of the ensuing neurological event. The approach in our unit has been to operate on symptomatic patients with demonstrated high grade or heterogeneous carotid artery atherosclerosis appropriate to the patient's symptoms. We have found that most asymptomatic patients have subcritical stenoses and dense homogeneous plaques, and we treat these conservatively. On the other hand, surgery is recommended for asymptomatic patients with high grade stenoses and heterogeneous plaques. We have been able to follow this policy with a morbidity and mortality of 2.6% and 1.0% respectively.
 ...
PMID:Is there still a place for carotid endarterectomy? 307 99

Results are presented of a retrospective analysis of 651 carotid endarterectomies in 605 patients with carotid territorial transient ischemic attacks (TIAs). All operations were performed by the same surgeon in a community hospital from 1963 to 1986. Arteriographic findings consisted of carotid stenosis of 50% or greater in 88.5% of patients and stenosis less than 50% and/or an ulcerated plaque in the remaining 11.5%. Medical risk factors were detected in 92% of patients; hypertension, peripheral vascular disease, and coronary atherosclerosis were most prevalent. All operative procedures were conducted with the patients under general anesthesia, routine shunting, and arterial closure without a patch. The perioperative stroke rate was 1.5% (10 patients); the morality rate was 0.8% (three deaths from myocardial infarction and two from stroke) for a combined stroke and mortality rate of 2.0% (13 of 605 patients). Follow-up (mean 61.8 months) was possible in 570 (96%) of the patients surviving operation without a perioperative stroke. The cumulative probability of late stroke (i.e., cerebral infarct ipsilateral to the operated artery) was 2.5% at 5 years and 8.1% at 10 years. When the perioperative stroke-mortality rate (2.0%) is combined with the data for late ipsilateral stroke, the 5- and 10-year probabilities of ipsilateral stroke were 4.5% and 9.9%, respectively (mean 1% per year for 10-year period). Coronary atherosclerosis accounted for 43% of late deaths and 16% of strokes. The perioperative stroke-mortality rate of 2.0% in this group of patients falls within the acceptable range for carotid endarterectomy in patients with TIA.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Carotid endarterectomy in patients with territorial transient ischemic attacks. 317 81

Cerebral amyloid angiopathy (CAA) is a biochemically heterogeneous entity most commonly associated with stroke syndromes, Alzheimer's disease (AD), Down's syndrome, and miscellaneous neurologic conditions. The authors have applied and extended (using formic acid pretreatment of histologic sections) an immunocytochemical technique that used antibody to a synthetic 28-amino acid peptide representing a segment of the AD amyloid precursor, to study CAA and related parenchymal amyloid deposits in brain tissues originally derived from: 1) patients with CAA with or without typical clinicopathologic features of AD, cerebral hemorrhage, and infarcts; 2) a young boy with angiocentric brain amyloid; 3) patients with familial (Icelandic, Dutch) forms of cerebral hemorrhage caused by CAA; and 4) Japanese patients with nonfamilial CAA-related brain hemorrhage, sometimes associated with histopathology characteristic of AD. Formic acid pretreatment of sections resulted in markedly enhanced staining of senile plaque core and microvascular, especially capillary, amyloid, and some apparent staining of the neuritic component of senile plaques. Perivascular halos of immunoreactive material were observed frequently. Neurofibrillary tangles were not immunolabeled, nor were blood vessels or any parenchymal components within cerebral white matter. CAA in Japanese patients with nonfamilial encephalic hemorrhages appeared immunocytochemically identical to AD-related CAA. Arterioles in brains that had severe CAA frequently showed significant stenosis of their lumina by nonamyloid hyaline or cellular material.
 ...
PMID:Immunohistochemical study of cerebral amyloid angiopathy. II. Enhancement of immunostaining using formic acid pretreatment of tissue sections. 317 97


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>