Platelet aggregation, stroke, and transient ischemic attack in middle-aged and elderly patients

Platelet aggregation was studied with optical density methods in a group of 39 patients with stroke or transient ischemic attacks (TIA) and in age, sex, and race-matched controls. The patients were divided at age 60 into young stroke patients and young controls (18 pairs) and old stroke patients and old controls (21 pairs). A semiquantitative measure of the threshold of phase II of platelet aggregation and distinct of disaggregation 3 minutes after peak aggregation were used as an index of platelet aggregability. Aggregability was significantly greater in young stroke patients than in young controls. Aggregability was similar in old stroke patients and old controls. Both old stroke patients and old controls were hyperaggregable compared with young controls, indicating that aggregability rises with age. This suggests that platelet aggregability is significant risk factor for stroke but is relatively more important in the younger than in the older stroke patient.     

Cigarette smoking as a determinant of high-grade carotid artery stenosis in Hispanic, black, and white patients with stroke or transient ischemic attack

The effect of chitin, poly-beta-(1 --> 4)-N-acetyl-glucosamine, and chitosan, a polymer of glucosamine obtained by the deacetylation of chitin, on growth and nutrient digestibility was studied in grass shrimp, Penaeus monodon. Shrimp were fed for 8 wk diets containing no supplement (control) or 2, 5 or 10 g/100 g chitin or chitosan. Each diet was fed to triplicate groups of shrimp with a mean initial body weight of 0.45 +/- 0.05 g. Significantly higher body weight gains were observed in shrimp fed the 5% chitin diet than in those fed the 10% chitin or the control diet. The weight gain of shrimp decreased as dietary chitosan supplementation level increased (r = 0. 87, P < 0.05). Feed efficiencies (FE) and protein efficiency ratios (PER) followed the same pattern. Lower protein and lipid digestibilities and lower body protein and lipid contents were observed in shrimp fed all chitosan-containing diets than in controls (P < 0.05). Carbohydrate digestibility was lower in shrimp fed the 10% chitosan diet than in those fed the control diet. Lower protein and lipid digestibilities, body lipid content and blood cholesterol concentration were observed in shrimp fed the 10% chitin diet compared with controls (P < 0.05). Higher weight gains, body lipid contents and blood cholesterol concentrations were observed in shrimp fed the 2 and 5% chitin diets than in those fed the chitosan diets. Shrimp fed the 5% chitin diet had higher protein and lipid digestibilities and higher body protein content than those fed the 5% chitosan diet (P < 0.05). These data suggest that dietary chitin, supplemented at 5%, enhances P. monodon growth, whereas chitosan depresses shrimp growth, regardless of the supplementation level.     

Oculoplethysmography. Evaluation of patients with transient ischemic attacks from internal carotid artery disease

Oculoplethysmography was used to evaluate 66 patients with transient ischemic attacks prior to cerebral angiography. Fifty-eight (87.9%) symptomatic internal carotid arteries had anatomically significant stenosis. Only 69 per cent of these 58 arteries had positive OPG test. Thirty-one per cent of the arteries were well compensated hemodynamically with collaterals and had a false negative test. A negative OPG test does not rule out an anatomically significant internal carotid artery stenosis.     

Soluble adhesion molecules reflect endothelial cell activation in ischemic stroke and in carotid atherosclerosis

BACKGROUND AND PURPOSE: Activation of endothelial cells and platelets plays an important role in the development of atherosclerosis and thrombotic disorders. Soluble adhesion molecules originating from these cells can be demonstrated in plasma. We hypothesized that elevated plasma concentrations of soluble P-selectin (sP-selectin), soluble intercellular adhesion mole-cule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), and soluble E-selectin (sE-selectin) can reflect activation of endothelial cells and/or platelets in acute ischemic stroke and in previously symptomatic internal carotid artery stenosis. METHODS: Plasma was sampled from patients within 2 days of acute ischemic stroke (n = 28), from patients with a previous (> 1 week) transient or persistent ischemic neurological deficit associated with stenosis of the internal carotid artery (n = 34), and from control patients without a history of vascular disease (n = 34). Concentrations of sP-selectin, sICAM-1, sVCAM-1, and sE-selectin were measured by means of an enzyme-linked immunosorbent assay. RESULTS: Compared with control subjects, sP-selectin and sE-selectin were significantly elevated in the acute stage of ischemic stroke (P < .0001 and P = .001, respectively) as well as in previously symptomatic carotid stenosis (P < .0001 and P = .0007). sICAM-1 and sVCAM-1 were not increased. CONCLUSIONS: The elevated levels of sE-selectin indicate that endothelial cell activation occurs both in the acute stage of ischemic stroke and in previously symptomatic carotid atherosclerosis. Increased sP-selectin concentrations reflect endothelial cell activation as well but may also be caused by platelet activation.     

Frequency of deep vein thrombosis in patients with patent foramen ovale and ischemic stroke or transient ischemic attack

To evaluate the additional value of transesophageal (TEE) compared with transthoracic (TTE) echocardiography and the role of patent foramen ovale (PFO) and deep vein thrombosis in the work-up of embolic events, patients with presumed cardiac embolic stroke or transient ischemic attack (neurovascular etiology was excluded) were prospectively studied by transthoracic and transesophageal contrast echocardiography. If PFO was detected echocardiographically, PFO size was assessed semiquantitatively and phlebography of both legs was performed. Two hundred forty-two consecutive patients (153 men, 60 +/- 15 years) were studied. In 197 patients, neuroimaging showed evidence of embolic infarction. TEE identified 138 potential cardiac sources of embolism in 111 patients, compared with 69 by TTE (p <0.01) in 59 patients. TEE detected potential cardiac sources in 52 patients with negative TTE examination and was significantly superior compared with TTE for identifying left atrial thrombi, spontaneous echo contrast, PFO, atrial septal aneurysm, and atheroma of the ascending aorta. In patients with a positive TTE, additional diagnostic information by TEE was found in only 6 patients and did not change therapy. Phlebography was performed in 53 patients with PFO and revealed deep vein thrombosis in 5 patients (9.5%); all had medium or large PFOs. Thus, in patients with cerebral ischemia of suspected cardiogenic origin and a normal TTE examination, TEE detects potential causes of embolism in 31% of patients and is therefore of diagnostic relevance. Conversely, in the presence of a diagnostic TTE an additional TEE confers only marginal diagnostic benefit. Deep venous thrombosis was detected in nearly 10% of patients with PFO as the sole identifiable cardiac risk factor. Given that in 4 of 5 patients deep vein thrombosis was clinically silent, phlebography should be performed in patients with medium or large interatrial shunts if paradoxical embolism is suspected.     

Chordoma and chondrosarcoma: relationship to the internal carotid artery

In 6 patients with chordoma and 1 patient with a chondrosarcoma in the petroclival region, the internal carotid artery (ICA) showed a rather interesting relationship. The striking finding was the marked anterior (ventral) displacement of the adjacent segments of the ICA by the tumour. Complete encasement of the artery was not seen despite the massive size of the tumour. Narrowing of the caliber of ICA was seen in 1 case. The displacement of the ICA pointed toward the origin of the tumour and the pattern of its spread suggested pre-operatively the pathological diagnosis. Pre-operative recognition of the carotid artery neoplasm relation helped to better protect the ICA during surgery on these formidable lesions.     

Differentiation between transient ischemic attack and ischemic stroke within the first six hours after onset of symptoms by using 99mTc-ECD-SPECT

The aim of this study was to define the accuracy of 99mTc-ethyl cysteinate dimer-single photon emission computed tomography (99mTc-ECD-SPECT) in distinguishing transient ischemic attack from completed ischemic stroke at early stages after the onset of symptoms. In a prospective study we examined 82 patients within 6 hours after the onset of symptoms (neurologic deficit caused by middle cerebral artery ischemia) using both 99mTc-ECD-SPECT and computed tomography (CT). The follow-up was based on Scandinavian Stroke Scale (SSS) 24 hours and 5-7 days, as well as on CT 7 days, after the event. SPECT evaluation was performed both visually and using semiquantitative region-of-interest (ROI) analysis. According to visual SPECT analysis, on admission 59 of 82 patients had activity deficits in the symptomatic hemisphere. After 7 days, all these patients had neurologic symptoms (SSS 28 +/- 12 points), caused by a cerebral infarction as evidenced with CT. Twenty-three of 82 patients displayed no early activity deficit despite clinical symptoms. None of these patients had neurologic symptoms after 7 days (indicating transient ischemic attack or prolonged reversible ischemic neurologic deficit). In the semiquantitative SPECT analysis, all patients had abnormal count densities in the respective ROI (activity < 90% compared with the contralateral side). All patients with transient ischemia (n = 23) had count rate densities more than 70% of the respective contralateral ROI, whereas all patients with subsequent infarction (n = 59) had values < 70%. Use of 99mTc-ECD-SPECT allows transient ischemia to be distinguished from ischemic infarction using relative regional activity thresholds within the first 6 hours after onset of symptoms.     

Homocysteine in sickle cell disease: relationship to stroke

This research project was conducted in the Ottawa-Carleton region of Ontario to provide information on reasons why students did not participate in a Grade 7 hepatitis B school immunization project, and to determine whether telephone contact increased attendance at the community catch-up clinics above that achieved by a notice sent home with the child from school. A matched comparison group design was used. The overall uptake of the first dose of the vaccine in the region was 94% of 8,560 eligible students; 90% were immunized at the school clinic and 4% at the community catch-up clinic. About 4% of the parents refused to have their child immunized at the school or catch-up clinics. Of parents in the intervention group 198 (95%) were contacted by phone. The major reasons for non-participation at the school clinics were: (1) the child was not at school on the clinic day, or the child was sick (51%), (2) there were problems with the consent form (21%), and (3) the parents did not know of the program (10%). More students from the intervention group (72%) came for vaccination than did those of the control group (50%) (p < 0.01).     

High intensity transient signals (HITS) in patients with carotid artery disease

Interest in the Doppler ultrasound phenomenon of "High Intensity Transient Signals" (HITS) is based on the, thus far, unproven hypothesis, that these signals may to some extent represent silent cerebral microembolism ahead of a TIA/stroke and hence identify patients at risk for stroke. We prospectively investigated 80 patients with 102 moderate/severe internal carotid artery lesions. Patients with additional potential sources of cerebral ischemia were excluded. Bilateral transcranial Doppler monitorings of the middle cerebral arteries (MCA) were performed for =>30 min. HITS occurred more often in patients with completed stroke (21.9%) than in patients with transient ischemic deficits (12.5%), but significantly less in asymptomatic subjects (4.3%) (p<0.05). The incidence was maximal in patients examined within the first week after the onset of stroke. HITS were significantly more often associated with severe (> 70%) (23.5%) than with moderate (50 - 70%) internal carotid artery stenosis (3.4%) (p<0.05). These figures are closely related to annual stroke risk estimates recently reported about patients evaluated in multi-centre trials for carotid endarterectomy, and support the concept that HITS associated with carotid disease represent an important individual risk predictor.     

Role of carotid sonography as a first examination in the evaluation of patients with transient ischemic attacks and strokes: benefit in relation to age

PURPOSE: We studied the influence of age on the utility of carotid sonography in patients with transient ischemic attacks and strokes. METHODS: The results of Doppler ultrasound examinations of the carotid arteries in 613 consecutive patients with transient ischemic attacks (n = 450) or strokes (n = 163) were analyzed for different age groups. For each patient, the grade of stenosis was scored for the ipsilateral internal carotid artery. The results of the ultrasound examinations were correlated with angiographic findings and findings at endarterectomy. The extent of atherosclerosis for each age group was expressed as the ratio between the number of grade II-IV stenoses (> or = 50%) in the carotid arteries and the number of patients in that group ("atherosclerosis ratio"). RESULTS: Under the age of 40 years, high-grade atherosclerotic stenoses were not found. However, 3 relatively young patients had dissections of the internal carotid arteries. The atherosclerosis ratio exceeded 0.5 for age groups 65-69 years through 80+ years. Among the patients with high-grade stenoses, ischemic heart disease prevented endarterectomy in 63% of patients in age group 80+ years, 44% in age group 75-79 years, and 26% in age group 70-74 years. CONCLUSIONS: Carotid sonography did not detect any significant atherosclerotic changes in young patients but was useful for diagnosing other etiologies of ischemic cerebral disease, eg, carotid dissection. At the other end of the spectrum, the impact of carotid sonography on patient management appears to be limited in patients over the age of 70 years. Carotid sonography seems to be most useful for patients 40-69 years old.     

Early transoesophageal echocardiography in cryptogenic and lacunar stroke and transient ischaemic attack

OBJECTIVE: To determine, prospectively, the effect of clinical factors on the duration of frank haematuria and the incidence of clot retention after transurethral resection of the prostate (TURP). PATIENTS AND METHODS: Seventy-nine men who underwent TURP in a 3-month period were entered into this study, during which the time to cessation of bleeding and the occurrence of clot retention(s) were recorded over a 4-week period. The effect of other clinical factors (histology, weight of tissue resected. operative duration, grade of surgeon and resection rate) was also assessed. RESULTS: Gross haematuria ceased in 47%, 73%, 96%, and 97% of patients at the end of the first, second, third and fourth weeks, respectively. The duration of postoperative bleeding was significantly associated with the weight of tissue resected and the operation time (P<0.001 and <0.05, respectively). Furthermore, five patients were re-admitted with clot retention, but there was no significant correlation between the occurrence of this morbidity and any of the other indices. CONCLUSION: Postoperative bleeding usually stops within 3 weeks of TURP. This period, which is about half the time hitherto assumed, is directly related to the size of the gland resected and the duration of the procedure. However, the occurrence of clot retention is not significantly associated with the duration of haematuria or any of the other clinical factors evaluated. Thus, a high fluid intake is mandatory for 3 weeks after TURP, but men who continue to bleed should be advised to continue with a high-fluid regimen until their urine is clear.     

Risk factors for ischemic stroke: Dubbo Study of the elderly

Extensive clinical experience with the implantable cardioverter defibrillator (ICD) combined with recently completed prospective, randomized trials like MADIT and AVID, have demonstrated the lifesaving efficacy of this therapy and its superiority compared to conventional medical management in treating patients at high risk of sudden arrhythmic death. This evidence has in turn spurred great interest in further ICD studies. Since the ability of the ICD to save lives is no longer in question, there is a need to reexamine the real objectives of these new studies.     

Evaluation of non-cerebral complications in light of ischemic stroke severity

Extracerebral complications which were observed in great number of ischemic stroke patients increased the risk of death and disability. Pneumonia, myocardial infarction, pulmonary embolisms and urinary tract infections are most often. We considered the influences of extracerebral complications on anterior circulation territory disturbances. A cohort of 1697 patients with first-ever ischemic stroke within anterior circulation region was evaluated. Patients were divided into three groups: A, B, C according to the heaviness of stroke. We understood the heaviness of stroke as a degree of cerebral disfunction occurring within the first 24 hours of the onset and assessed it using Clinical Groups of the Whole Body Activity (CG WBM). CG WBM is an original classification, a three-degree one, prepared by Department of Neurology University School of Medicine Sciences in Bydgoszcz. The rate of complications was statistically significantly lower in group A with the mild course of ischemic stroke than in group B with moderate or in group C with the severe course of ischemic stroke. Pneumonia, myocardial infarction and pulmonary embolism were recognized more often in patients with fatal outcome. The amount of extracerebral complications raised with the severity of the ischemic stroke.     

Allergen-induced cytokine production in atopic disease and its relationship to disease severity

The Th2 cytokines, interleukin (IL)-4 and IL-5, have an important role in atopic disease. CD30 is a transmembrane molecule that may be expressed on a proportion of activated T-lymphocytes and has been reported to be a marker for Th2 phenotype. Our objective was to compare the in vitro cytokine responses and CD30 expression of peripheral blood mononuclear cells (PBMCs) to stimulation with house dust mite antigen (Dermatophagoides pteronyssinus) in atopic asthmatics, atopic nonasthmatics, and normal subjects, and to see if atopic asthmatic cytokine production correlated with symptomatic disease activity and whether cytokine production was allergen-specific. Eighteen atopic asthmatics (all were allocated a symptomatic disease score), 6 atopic nonasthmatics, and 7 healthy nonatopic individuals were studied. Resting serum IL-4 levels were measured, then PBMCs were separated using Lymphoprep density centrifugation and cultured in modified RPMI 1640 medium. PBMCs were stimulated with IL-2 alone or with D. pteronyssinus (1,000 subcutaneous units/ml) with IL-2 and harvested after 5 and 10 d. Using monoclonal antibodies and flow cytometry we obtained the percentage of CD4+ T cells expressing CD30 and the intensity of CD30 staining. Culture supernatants were analyzed for IL-4 and interferon gamma (IFN-gamma) using an enzyme-linked immunosorbent assay. In 9 atopic asthmatics PBMCs were also stimulated nonspecifically using phytohemagglutinin (PHA). IL-4 was detectable in the serum of atopic subjects but not in normal subjects. Stimulation of PBMCs with D. pteronyssinus produced significant amounts of IL-4 in atopic asthmatics and atopic nonasthmatics, but minimal quantities in normal subjects. Much lower levels of IFN-gamma were produced by atopic asthmatics in response to D. pteronyssinus compared to atopic nonasthmatics. IFN-gamma levels had an inverse correlation with asthmatic symptom score. CD4+ T-cell expression of CD30 also correlated inversely with IFN-gamma production and IFN-gamma:IL-4 ratio. PHA produced minimal levels of IL-4 compared to specific allergen stimulation. It is concluded that different groups of atopic patients exhibit different patterns of allergen-induced cytokine production. In vitro allergen-induced cytokine production in atopic asthmatics correlated with symptomatic disease activity, and is allergen-specific.     

Lipoprotein(a) in patients with carotid atherosclerosis and ischemic cerebrovascular disorders

Two novel peptides, named PACAP (pituitary adenylate cyclase activating polypeptide) containing 38 (PACAP38) and 27 residues (PACAP27) were recently isolated from ovine hypothalami. In order to investigate the pituitary cell type(s) that bear a receptor for PACAP, PACAP38 was biotinylated and used for cytochemical examination of binding. The cells were also identified by immunocytochemical methods using the antisera against each of the rat anterior pituitary hormones or an antiserum against S-100 protein, a marker for pituitary folliculo-stellate (FS) cells. Biotinylated PACAP38 (biot-PACAP) exhibited adenylate cyclase stimulating activity (ACSA) comparable to PACAP38 in rat pituitary cell cultures, and displaced the bound 125I-PACAP27 to the rat pituitary membrane preparation to the same extent as PACAP38. After 2-4 days of culture, dispersed rat pituitary cells were incubated with varying concentrations of biot-PACAP at room temperature or 4 degrees C. The bound biot-PACAP38 was visualized by avidin-biotin-peroxidase complex (ABC) method with nickel intensification. Biot-PACAP-positive and pituitary hormone or S-100-positive cells were counted. More than 90% of S-100-positive cells bound biot-PACAP38. A considerable number of GH and PRL cells and a lesser number of ACTH cells also bound biot-PACAP38, whereas only a few identified LH, FSH, or TSH cells bound biot-PACAP38. These results suggest that FS cells are a major target cell type for PACAP. A recent study from our laboratory demonstrated that PACAP stimulated the release of interleukin (IL)-6 in rat pituitary cell cultures. FS cells are known to produce IL-6.     

Ultrasonographic manifestations of carotid atherosclerosis and glucose intolerance in elderly eastern Finnish men

OBJECTIVE: To study the association of ultrasonographic manifestations of common carotid atherosclerosis with glucose intolerance in survivors of the cohort of men born in 1900-1919 in eastern Finland. RESEARCH DESIGN AND METHODS: Carotid ultrasonography was carried out for 182 men in 1989. Glucose tolerance status classified based on an oral glucose tolerance test in 1984 and 1989 surveys was used in both prospective and cross-sectional analyses. RESULTS: Carotid atherosclerosis was common in men aged 70-89 years. There was no significant difference in the maximal carotid intimal-medial thickness between diabetic and nondiabetic men and over different age-groups; it was 1.28, 1.33, and 1.36 mm in subjects with diabetes, impaired glucose tolerance, and normal glucose tolerance, respectively (P = 0.69). No association between the presence of a nonmineralized or a mineralized atherosclerotic lesion with diabetes was found. Fasting plasma insulin did not relate to ultrasonographically detectable atherosclerotic lesions. CONCLUSIONS: Hyperglycemia and hyperinsulinemia may not be main contributors to atherosclerosis in elderly men, partly because smoking is less common and total and LDL cholesterol concentrations are lower in diabetic men than in men with normal glucose tolerance.     

Cognitive performance in HIV-1 infection: relationship to severity of disease and brain atrophy

We examined cognitive performance in 72 HIV-1 infected patients and 34 controls. None of the patients had opportunistic infections or unusual neoplasms of the central nervous system (CNS). Factors other than HIV-1 known to cause cognitive decline were excluded from both groups. Cognitive functioning analysed with special emphasis on the severity of HIV infection was related to neuroradiological and immunological findings. In patients with AIDS-related complex (CDC IVa) or AIDS (CDC IVc,d), a deterioration of memory as well as cognitive speed and flexibility was detected. Furthermore, memory deficits were associated with central cerebral and infratentorial atrophy in those patients, while no association was found between cognitive deficits and immunological abnormalities. Patients at CDC stages II or III showed slight association between altered cognitive speed and flexibility and elevated leukocyte count, suggesting a subclinical CNS disease already at early stages of HIV infection.     

The relationship of hydroxyeicosatetraenoic acids and F2-isoprostanes to plaque instability in human carotid atherosclerosis

Evidence for increased oxidant stress has been reported in human atherosclerosis. However, no information is available about the importance of in situ oxidant stress in relation to plaque stability. This information is relevant because the morbidity and mortality of atherosclerosis are essentially the consequences of acute ischemic syndromes due to unstable plaques. We studied 30 carotid atherosclerotic plaques retrieved by endarterectomy from 18 asymptomatic (stable plaques) and 12 symptomatic patients (unstable plaques). Four normal arteries served as controls. After lipid extraction and ester hydrolysis, quantitation of different indices of oxidant stress were analyzed, including hydroxyeicosatetraenoic acids (HETEs), epoxyeicosatetraenoic acids (EETs), ketoeicosatetraenoic acids (oxo-ETEs), and F2-isoprostanes using online reverse-phase high-performance liquid chromatography tandem mass spectrometry (LC/MS/MS). All measurements were carried out in a strictly double-blind procedure. We found elevated levels of the different compounds in atherosclerotic plaques. Levels of HETEs were 24 times higher than EETs, oxo-ETEs, or F2-isoprostanes. Levels of HETEs, but not those of EETs, oxo-ETEs or F2-isoprostanes, were significantly elevated in plaques retrieved from symptomatic patients compared with those retrieved from asymptomatic patients (1, 738 +/- 274 vs. 1,002 +/- 107 pmol/ micromol lipid phosphorous, respectively; P < 0.01). One monooxygenated arachidonate species, 9-HETE, which cannot be derived from known enzymatic reactions, was the most abundant and significant compound observed in plaques, suggesting that nonenzymatic lipid peroxidation predominates in advanced atherosclerosis and may promote plaque instability.