ISSN:0039-2499    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

We tested the antiplatelet effects of low-dose aspirin in patients with occlusive cerebrovascular disease, because conventional dosage aspirin inhibits vascular synthesis of prostacyclin at the same time that it inhibits platelets. The effects on platelet function and thromboxane A2synthesis of 40 mg of aspirin daily or 40 mg aspirin plus dipyridamole were measured in 23 patients starting within a week after the onset of cerebral ischemia. All patients had normal baseline platelet aggregation responses to four stimuli: arachidonate, epinephrine, adenosine diphosphate and collagen. The generation of thromboxane A2 by platelets, measured as serum thromboxane B2, was also normal. After 3 to 7 days of low dose aspirin therapy, platelet aggregation responses were suppressed to the extent observed with higher dosage aspirin. Serotonin release during platelet aggregation was inhibited by more than 95% and thromboxane B2levels in clotted blood fell by more than 95%. Responses to aspirin treatment were similar in patients with transient ischemic attacks and in those with stroke and were also similar in both sexes. No differences in platelet responses were observed between patients receiving aspirin alone and aspirin plus dipyridamole. Thus 40 mg aspirin daily inhibited platelet responses as effectively as higher doses of aspirin in patients who had recent cerebral ischemia and showed a cumulative antiplatelet effect.

ISSN:0039-2499    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

Thromboxane B2 (TXB2) is the stable metabolite of thromboxane A2 (TXA2), a potent vasoconstrictor which induces irreversible platelet aggregation. The inhibition of TXA2 by aspirin and other agents has been associated with improved outcome following cerebral ischemia in clinical and laboratory studies. To investigate the relation of TXA2 production to cerebral ischemia, we measured the urinary excretion of TXA2 metabolites in 30 patients with acute cerebral ischemia. Urinary immunoreactive TXB2 for this group of ischemic patients was elevated compared to normals, 1818 ± 344 pg/mg Cr (mean ± SE) vs 880 ± 122 pg/mg Cr (p<.05). Among various subsets of the ischemic patients, those with severe stroke (2108 ± 536 pg/mg Cr), large vessel disease (1646 ± 335 pg/mg Cr), and cardiogenic stroke (2712 ± 1045 pg/mg Cr) were all significantly elevated. Of the stroke patients, only the males demonstrated this significant elevation. These elevations of urinary immunoreactive TXB2 are consistent with a role for increased platelet activation in the pathogenesis of some forms of cerebral ischemia and suggest that gender differences in arachidonate metabolism may exist for stroke patients.

ISSN:0039-2499    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

Beta-thromboglobulin (betaTG) and malondialdehyde-like material (MDA-LM) plasma levels were studied in patients affected by transient ischemic attacks (TIA) after 2-4 months from the last episode. BetaTG and MDA-LM values were significantly higher in TIA patients than in 20 controls matched for age. No correlation between MDA-LM and betaTG was seen. This study suggests that in vivo platelet activation and, likely, increase of platelet cyclo-oxygenase activity can be detectable in TIA patients.

ISSN:0039-2499    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

Prostacyclin is a powerful vasodilator and inhibitor of platelet aggregation that has been implicated to play a role in cerebrovascular disease. Prostacyclin is unstable in aqueous solution and stabilized in serum by binding to an unidentified serum protein as measured by gel filtration. In 15 patients with ischemic stroke we measured the serum prostacyclin binding capacity and the rate of degradation of exogenously added prostacyclin. There was a significant reduction in serum prostacyclin binding capacity and a significant increase in rate of degradation in the patients with ischemic stroke as a whole compared to controls, and in patients with persistent deficits compared to those with transient deficits. Decreased serum prostacyclin binding capacity and accelerated rate of prostacyclin degradation in vitro, may reflect an accelerated rate in vivo of prostacyclin degradation, thereby increasing susceptibility to stroke. Since only a small number of patients were investigated, the findings are of a preliminary nature and must be confirmed by further studies with large numbers of patients and appropriate patient controls.

ISSN:0039-2499    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

The effects of ethanol ingestion on ADP-induced platelet aggregation and associated thromboxane formation were studied in the platelet-rich plasma of 10 healthy male volunteers, each serving as his own control. Ethanol caused a transient decrease in threshold concentration of ADP to produce irreversible aggregation. Over a wide range of ADP total platelet aggregation was increased. In the presence of irreversible aggregation, formation of thromboxane B2 rose from 303 ± 56 to 950 ± 212 fmol per 107 platelets (p< 0.01). The effects lasted as long as ethanol was present in blood, did not significantly correlate to blood ethanol levels and exhibited great individual variation. It remains to be proved, whether these observations could contribute to the increased risk of ischemic brain infarction associated with acute ethanol ingestion.

ISSN:0039-2499    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

Impact of digital substraction angiography by intravenous injection (DSAV) was. examined in a private neurology clinic. In the evaluation of threatened stroke, advent of DSAV was associated with reduced use of both traditional noninvasive tests (from 100% of patients to 36%), and conventional arteriograms (from 29% to 4%). Less compelling indications were often prescreened with noninvasive tests; more compelling symptoms usually had initial DSAV. Conventional arteriograms were done for compelling indications and negative or inadequate DSAV. The average cost of evaluation was increased siightiy in patients treated medically and reduced greatly in those having surgery. While cost and convenience might support such utilization, issues of quality of evaluation require consideration.

ISSN:0039-2499    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

In a prospective controlled trial we compared the clinical outcome for unselected acute stroke patients in a non-intensjve stroke unit (n= 110) and in general medical wards (n= 183). The patients were comparable in age, marital state and functional impairment on admission. Case fatality rates over the first year after the stroke were similar in the two groups. By three months after the stroke, 15% of the survivors initially admitted to the stroke unit and 39% of those admitted to general medical wards remained hospitalized (p< 0.001). The corresponding figures by one year after the cerebrovascular accident were 12% and 28%, respectively (p< 0.05). A greater proportion of surviving stroke unit patients was independent in walking (0.10 >p> 0.05), personal hygiene (p< 0.05) and dressing (p< 0.001). Essential features of the stroke unit are team work headed by a stroke nurse, staff, patient and family education and very early onset of rehabilitation. We conclude that this strategy improves functional outcome and reduces the need for long-term hospital care.

ISSN:0039-2499    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

One hundred neurologically asymptomatic male subjects (aged 50-69 years), randomly selected through population registers, were screened for atherosclerotic lesions of the cervical carotid arteries, using a high resolution multi-gate pulsed Doppler system. In 93 subjects serum was assayed for total and HDL cholesterol. Besides, cuff arterial blood pressure measurements were made. Twenty-three of these subjects (Group III) were classified as abnormal according to the Doppler investigation (degree of narrowing < 50% in 78% of the cases). Seven of these 23 subjects also had a history of ischemic heart disease or intermittent claudication. Of the 70 subjects with a normal Doppler examination 16 had a history of ischemic heart disease and/or intermittent claudication (Group II). The remaining 54 subjects served as controls (Group I). The frequency of asymptomatic atherosclerotic lesions of the cervical carotid arteries in the population under investigation was 23%. The HDL/total cholesterol ratio was lower and the frequency of high blood pressure higher in the Groups II and III than in Group I. The findings in this study support the idea that a low serum HDL/total cholesterol ratio and high blood pressure have a high degree of association with atherosclerotic lesions of the cervical carotid arteries. This association is already apparent at an early stage of the disease, i.e. in asymptomatic subjects with a slight to moderate degree of carotid artery narrowing.

ISSN:0039-2499    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

Fluosol-DA (Perfluorochemical Blood Substitute) was investigated in a previous study and found to provide some protection from ischemia and possible usefulness in limiting the size of infarction. In the present study, larger doses over longer periods of acute focal cerebral ischemia were used. Twenty four cats had transorbital ligation of the middle cerebral artery (MCA). The 12 experimental animals were given 20% Fluosol-DA. The control group of 12 received isotonic saline solution. Twenty-four hours after the MCA occlusion, the cats were perfused with saline and phosphate-buffered formalin. The brains were removed and immersed in 10% formalin for 2 weeks. The results of macroscopic and histological examination suggested that, although Fluosol-DA did not provide complete protection from ischemic injury to the brains of the cats treated, it may have helped to slow the development of the pathological changes.

ISSN:0039-2499    

出版商:OVID    

年代:1985

数据来源: OVID