Search PubMed⌕ Search

Biomedical subjects

J F Toole

Publications and source records attributed to J F Toole.

At least 73 records · Page 4Linked to original sources
PubMed1989

Cigarette smoking cessation and extracranial carotid atherosclerosis.

Using B-mode ultrasonography, cigarette smoking was found to be a strong, independent risk factor for extracranial carotid atherosclerosis in 1692 black and white men and women admitted for diagnostic evaluation of the carotid arteries. We found that the difference in mean plaque thickness was smaller between past smokers and nonsmokers than between current smokers and nonsmokers, suggesting that the rate of progression of carotid atherosclerosis may be slower in people who quit smoking compared with people who continue to smoke.

Adult↗
PubMed1989

The effect of radiation on carotid arteries. A review article.

The effects of irradiation on blood vessels supplying the brain are reviewed. Short-term and long-term effects on large arteries result in an atheroscleroticlike disorder. The response may have a latency up to 20 years before the onset of symptoms and signs. This delay is probably related to the diameter of the irradiated artery; the interval is longer for larger arteries. However, it is possible that the apparent injury to the large arteries is in fact due to occlusion of the vasa vasorum because the microvasculature is especially vulnerable to radiation damage.

Animals↗
PubMed1989

Cerebral infarction in patients with transient ischemic attacks.

Cranial computed tomography of 284 patients with transient ischemic attacks (TIAs) and without previous stroke was evaluated. The sample population included patients with carotid and/or vertebrobasilar TIAs. Computed tomography revealed cerebral infarction in 34 patients, including 5 with multiple infarctions. The lesion location was consistent with TIA symptoms in 16 patients. In another 16 patients, however, the lesion location did not correspond to the TIA symptoms; these lesions were attributed to previous silent infarctions. Two patients with multiple infarctions had both symptomatic and asymptomatic lesions. Age and carotid stenosis were each significantly related to an increased chance of detecting cerebral infarction (either symptomatic or asymptomatic). No significant relationship between race, gender, hypertension, diabetes, cardiac disease, or smoking and the incidence of infarction was found by either univariate or multivariate analyses.

Aged↗
PubMed1989

Cause specific mortality following cerebral infarction.

Mortality from four causes (index stroke, subsequent stroke, cardiac disease and non-cardiovascular causes) was examined during a 5 year follow-up of 1694 cerebral infarction patients admitted to 25 community hospitals between 1969 and 1973. The hazard for mortality from the index stroke was high initially, but declined to a negligible level by 6 months post-stroke. In contrast, hazards for mortality from subsequent strokes, cardiac diseases and non-cardiovascular causes each peaked midway through the first year, declined during the remainder of that year, and then increased in the latter part of the follow-up. Proportional hazards analysis indicated that advanced age and increased stroke severity were the only factors significantly related to increased risk from each of the four causes of death. Other risk factors were significant only for one or two select causes of death. White patients were less likely to die from subsequent strokes, but more likely to die from cardiac diseases, than were non-white patients (primarily blacks). Males were more likely to die from both the index stroke and non-cardiovascular causes than females. A history of cardiac disease increased the risk of death from both the index stroke and from future cardiac events, while a history of hypertension or diabetes increased the risk of death from non-cardiovascular causes, and a history of previous stroke increased the risk of death from subsequent stroke.

Age Factors↗
PubMed1989

Correlation of carotid bruits and carotid atherosclerosis detected by B-mode real-time ultrasonography.

The extent of carotid atherosclerosis evaluated by B-mode real-time ultrasound and the presence of bruits established by carotid phonoangiography were determined in 1,107 patients. Unilateral bruit was associated with increased atherosclerosis compared with no bruit (p less than or equal to 0.0001). However, there was no association between laterality of the bruit and the degree of atherosclerosis (p = 0.66). There was marginal evidence that patients with bilateral bruits had more severe atherosclerosis than patients with unilateral bruit (p = 0.046). The relation between bruit and atherosclerosis categorized by B-mode ultrasound was not sufficient to reliably predict the presence or absence of disease in an individual patient, though the presence of a bruit should be viewed as a risk factor for, or an indicator of, increased risk of systemic atherosclerosis.

Auscultation↗
PubMed1989

Pentoxifylline increases cerebral blood flow in patients with cerebrovascular disease.

We determined the immediate effects of pentoxifylline on cerebral blood flow in 10 patients with cerebrovascular disease; four received 400 mg and six received 800 mg pentoxifylline orally. Regional cerebral blood flow was measured before (baseline) and 2, 4, and 6 hours after pentoxifylline administration using the xenon-133 clearance technique with 16 detectors (eight per hemisphere). Global cerebral blood flow as a percentage of the baseline value increased significantly after 800 mg but not 400 mg pentoxifylline (p = 0.017 and p = 0.29, respectively). Regional cerebral blood flow as a percentage of the baseline value at the detector with the lowest baseline value increased significantly 2 hours after both 400 mg and 800 mg pentoxifylline (p = 0.038 and p = 0.010, respectively). Cerebrovascular reactivity to carbon dioxide was preserved despite the increases in cerebral blood flow. Pentoxifylline increases cerebral blood flow and is not associated with "intracerebral steal" in patients with cerebrovascular disease.

Aged↗
PubMed1989

Changes in survival following stroke in five North Carolina counties observed during two different periods.

We evaluated survival following stroke for patients from a five-county area of rural North Carolina enrolled in either of two community hospital-based stroke survey programs. In this area, the first program enrolled 843 stroke patients between 1970 and 1973 and the second program enrolled 786 stroke patients between 1979 and 1980. One-year survival increased from 49% in the first program to 62% in the second for all stroke patients, from 54% to 68% for patients with cerebral infarction, and from 18% to 55% for patients with cerebral hemorrhage. While other reports have attributed declining stroke mortality to a decline in the incidence of stroke, our study suggests that increased survival after stroke may account for a large portion of the decrease in stroke mortality.

Actuarial Analysis↗
PubMed1989

Extracranial carotid atherosclerosis in black and white patients with transient ischemic attacks.

To evaluate the association between extracranial carotid atherosclerosis, race, and transient ischemic attack, we carried out a retrospective hospital chart review and quantified the extent of noninvasively determined extracranial carotid atherosclerosis in 25 black patients greater than 45 years old with transient ischemic attacks. Two sex- and age-matched white patients with transient ischemic attacks were similarly studied for each black patient. Extent of extracranial carotid atherosclerosis (expressed as B-mode score) was similar for blacks and whites. B-mode score was only slightly less in patients with posterior- than in those with anterior-circulation transient ischemic attacks. Fifty-six patients (35 white, 21 black) had unilateral anterior-circulation transient ischemic attacks. Of the 32 patients with more extensive extracranial carotid atherosclerosis ipsilateral to the affected hemisphere, 23 (66% of 35) were white; only nine (43% of 21) were black. In the 35 white patients, the extent of disease in the ipsilateral carotid artery was significantly greater (p less than 0.03) than that in the contralateral carotid artery. When B-mode scores in the left and right carotid arteries were combined for the subgroup of patients with unilateral anterior-circulation transient ischemic attacks, blacks had slightly more atherosclerosis in the extracranial arteries than whites.

Arteriosclerosis↗
PubMed1989

Changes in survival after transient ischemic attacks: observations comparing the 1970s and 1980s.

We compared survival following transient ischemic attack (TIA) in 2 prospective cohorts of TIA patients admitted to Wake Forest University Medical Center. The 1st consisted of 177 patients admitted between 1961 and 1973, and the 2nd of 185 patients admitted between 1980 and 1983. Patients in the 2nd cohort had significantly greater longevity than patients in the 1st cohort, both univariately and after adjustment for cerebrovascular risk factors. The adjusted 1-year survival estimate increased from 91% in the 1st cohort to 98% in the 2nd, and the adjusted 3-year survival estimate increased from 83% in the 1st to 94% in the 2nd. The underlying causes for this dramatic improvement in survival may include early identification and aggressive management of TIAs or coexisting diseases, improved management of subsequent completed strokes or myocardial infarctions, or unadjusted differences in these cohorts. The data imply that reports of TIA survival from different periods may not be comparable.

Cohort Studies↗
PubMed1988

Carotid endarterectomy: what is its current status?

The plethora of recent articles regarding carotid endarterectomy has tended to confuse rather than clarify its indications, efficacy, and acceptability. The National Institutes of Health has recently funded two large multicenter controlled clinical trials, one including asymptomatic persons with carotid stenoses, and the other, patients having transient ischemic episodes or minor strokes. Eight academic professors of neurology (four), neurosurgery (two), and vascular surgery (two) with a long and abiding interest in cerebrovascular disease prepared a statement delineating acceptable levels of mortality and morbidity from this procedure. These might serve as guidelines until the large trials have been completed.

Arteriosclerosis↗
PubMed1987

Middle cerebral artery stenosis--a neglected problem?

Transcranial Doppler ultrasonography has great potential for clinical investigations that evaluate flow through the middle cerebral artery in health and disease. This technique will help to elucidate the syndromes of middle cerebral artery stenosis and occlusion, which have been overshadowed by the syndromes of internal carotid artery disease in the past.

Arterial Occlusive Diseases↗
PubMed1987

Multicenter validation study of real-time (B-mode) ultrasound, arteriography, and pathologic examination.

The ability of high-resolution ultrasound, angiography, and pathologic examination of endarterectomy specimens to identify and quantitate atherosclerosis was compared in a five-center study. The carotid bifurcation in 900 patients was evaluated by angiography and ultrasound. In 216 cases, high-quality endarterectomy specimens were available for comparison with the preoperative images. All comparisons were made in a blinded fashion. Results indicate that ultrasound is able to differentiate angiographically normal from abnormal arteries with a sensitivity of 88% (1077 of 1233 arteries) and accuracy of 79% (1251 of 1578 arteries). Angiographic stenoses equal to or greater than 50% diameter were accurately identified by ultrasound imaging in 72% (1133 of 1578 arteries) of cases, and this was improved by the addition of other functional data (i.e., Doppler spectral analysis and oculoplethysmography). There was only modest correlation of absolute measurements of lesion width, minimal lumen, and standard lumen by the two imaging techniques (r = 0.28 to 0.55). Ultrasound measurements of lesion width were on the average 2 mm greater than those of angiography. The lumen averaged 1.5 mm larger when measured by ultrasound techniques. In the subset in which data were available from endarterectomy specimens, ultrasound showed the best correlation with lesion width (mean difference -1.1 mm) and angiography correlated best with minimal lumen (mean difference -0.1 mm). Neither examination consistently identified ulcerated plaques. Although ultrasound imaging alone has limited usefulness in quantitating luminal stenosis, this can be improved by the use of Doppler spectral analysis and oculoplethysmography. Ultrasound is superior to angiography for quantifying atherosclerotic plaque (lesion width) and will be an important tool for further study of atherosclerotic lesions.

Adolescent↗
PubMed1986

Asymptomatic carotid bruit and stenosis. A prospective follow-up study.

We observed 70 patients with asymptomatic carotid bruits with and without stenoses for cerebral and myocardial ischemic events. Four patients developed transient ischemic attacks (TIAs) without subsequent cerebral infarctions; all of the TIAs occurred distal to vessels with greater than or equal to 50% stenoses. Three cerebral infarctions occurred, but only one was distal to a vessel with stenosis greater than or equal to 50%. Six myocardial infarctions occurred, predominantly in patients with previous myocardial infarctions, congestive heart failure, and left ventricular hypertrophy. Our results confirm previous reports that an asymptomatic carotid stenosis is more often complicated by a TIA than an unheralded cerebral infarction. Cerebral infarctions that do occur are often only marginally related to the carotid bifurcation lesion. In patients with asymptomatic carotid bruit and stenosis, myocardial infarctions occur more frequently and are more commonly the cause of death than cerebral infarctions.

Aged↗
PubMed1985

Factors influencing return to work following cerebral infarction.

A study of 379 patients, employed before cerebral infarction and living one year afterward, was undertaken to determine what factors had influenced their returning to work. We found age, occupation, degree of disability, race, and hemisphere infarcted to be significant. Younger patients with less disability were more likely to return to work. Patients employed in professional-managerial positions were more likely to return to work than patients in blue-collar or farming positions. Although there were no racial differences following a left-hemisphere infarct, white patients were more likely to return to work following a right-hemisphere infarct. Sex, blood pressure, severity of stroke, educational level, consciousness level at admission, maximum weakness in extremities, first v repeated stroke, care by a specially trained stroke team, rehabilitation therapy, and speech did not additionally influence the probability of returning to work.

Age Factors↗
PubMed1985

The role of plasma lipids in carotid bifurcation atherosclerosis.

The severity of coronary artery atherosclerosis correlates with increased plasma concentrations of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglycerides and with decreased plasma concentrations of high-density lipoprotein cholesterol (HDL-C). The role of plasma lipoproteins in the pathogenesis of cerebral atherosclerosis, however, is less clear. Several investigators report that lipoprotein abnormalities correlate inversely with the incidence of cerebral infarction. We analyzed risk factors for carotid bifurcation atherosclerosis in 121 consecutive patients who underwent cerebral angiography. This analysis revealed a significant positive correlation between the plasma TC/HDL-C ratio and the extent of carotid bifurcation atherosclerosis (p = 0.01). The extent of atherosclerosis correlated inversely with plasma concentrations of HDL-C (p = 0.02). Triglyceride concentration correlated positively with the extent of atherosclerosis with marginal significance (p = 0.07). LDL-C and TC concentrations did not correlate with bifurcation atherosclerosis (p greater than 0.1). Only 4% of the variation in the extent of bifurcation atherosclerosis was explicable on the basis of plasma lipoprotein concentrations.

Aged↗