摘要:

Bilateral carotid artery ligation was made in 14 SHR while rCBF was serially measured with hydrogen clearance. Blood pressure was controlled with an intra-arterial catheter connected to a reservoir. There was no significant correlation between blood pressure and rCBF prior to the carotid occlusion, but afterwards there was a progressirely increasingly negative correlation between mean arterial blood pressure and rCBF with time. These observations indicate that the severity of ischemia is greater in the presence of hypertension if the hypertension is present prior to the onset of ischemia and the blood pressure maintained constant thereafter.

ISSN:0039-2499    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

The major conceptions of cerebral blood flow (CBF) control dereloped In the 19th and 20th centuries are listed. The systems of CBF regulation are considered from the viewpoint of automatic control. In the classification of CBF regulation mechanisms, 4 types are identified. The effectors of CBF regulation, i.e. the specific arterial segments through which each type of regulation is accomplished, were found to be mainly the major arteries of the brain and the small pial arteries rather than the intracerebral arterioles. Review of controlling influences on these effectors of regulation, (myogenic, humoral and neurogenic), show that priority should be given to neurogenic mechanisms. Several criteria governing efficiency of CBF regulation are proposed. Review of interactions of different types of CBF regulation shows that there may be both synergistic and antagonistic relationships. Information about the processes is important for medical practice.

ISSN:0039-2499    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

Non-invasive ultrasonic imaging of the carotid bifurcation by duplex scanning and ultrasonic arteriography combined with pulsed Doppler spectrum analysis demonstrated patency of the external and internal carotid arteries distal to a common carotid occlusion in 3 patients. Common carotid occlusion is not invariably associated with thrombosis of the ipsilateral internal carotid artery. Identification of internal carotid patency by the use of ultrasonic techniques will permit surgical treatment in selected cases.

ISSN:0039-2499    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

Statistical analyses were made of the mortality of persons diagnosed as having definite TIA in an epidemiologic survey of a biracial Southern community. None of the usual risk factors associated with this illness such as heart disease, hypertension or diabetes appears to account for the excess deaths observed in a 10 year period of follow up.

ISSN:0039-2499    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

Of 312 stroke patients who bad a CT scan, 37 had presented clinically with a lacunar syndrome. In 18 of the 37, lacunar sized infarcts were demonstrated on the scan, 13 had normal scans and in 6 large infarcts were found. Of these 6, 5 had a pure motor hemiplegia and one a pure sensory stroke.Clinical evidence and anglography revealed a potential and treatable source of eraboli in both the lacunar sized and the large infarcts. Two conclusions are drawn: a clinical lacunar syndrome may be associated with a large infarct; demonstration of a lacunar infarct on CT scan does not exdude the need for angiography in appropriate cases to discover a possible source of eraboli.

ISSN:0039-2499    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

In helically-cut strips of dog cerebral, coronary and mesenteric arteries, contracted with prostaglandin (PG) F2αor K+, tbe addition of verapamii caused a dose-related relaxation. Verapamil-induced relaxations were greater in cerebral than in the other arteries when contracted with PGF2α, but did not significantly differ in tbe arteries contracted with K+. Similar results were obtained with diltiazem and nifedipine. The contractile response to PGF2αwas attenuated by pretreatment with verapamii, the attenuation being greater in cerebral than in mesenteric arteries. Nitrogiycerin and sodium nitroprusside relaxed cerebral, coronary and mesenteric arteries contracted with PGF2αto a similar extent. It may be concluded that dog cerebral arteries contracted with PGF2α, one of endogenous rasospastic substances, are more susceptible to agents which interfere with the influx of Ca++across cell membranes than coronary and mesenteric arteries; these agents may thus be of value in the treatment and prophylaxis of cerebral vasospasm.

ISSN:0039-2499    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

The ratio between media thickness and lumen radios was determined in cerebral arterial vessels of 15- and 200-day-old spontaneously hypertensive (SHR) and normotenshe rats (Kyoto Wistar and local Wistar rats). A modification of Furuyama's morpbometrical method was used. There was a statistically significant increase of media/radius ratio among medium size and large vessels in 15-day-old SHR. Furthermore, the media cross section area and lumen radius was increased in the internal carotid arteries of young SHR. These early vascular aberrations could be caused by the slight increase of blood pressure at this age or be due to other genetically determined mechanisms in SHR. In 200-day-old SHR a significantly increased media/radius ratio was seen in arterial vessels with a radius <80 μm when compared to local Wistar rats but only in the smallest arterioles (r< 20 μm) when compared to Kyoto Wistar rats. The present results offer a likely explanation for the increased cerebrovascular resistance during maximum vasodilatation in SHR.

ISSN:0039-2499    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

Cerebral hypoxla-ollgemia was produced by lowering of the arterial Po2to 30 mm Hg and by right common carotid artery occlusion in rats who were pretreated with intravenous Krebs' solution, gammahydroxybutyrate (GHB) (500 mg/kg) or gamma-butyrolactone (GBL) (300 mg/kg). At 0.5 h exposure the right cerebral hemisphere of animals receiving Krebs', GHB or GBL showed equivalent decreases of ATP and phosphocreatine and increases of ADP, AMP and lactate which indicated that these depressant drags had no beneficial effect on the energy metabolism of the acutely hypoxlc-oligemic brain. In a second series of rats in which Krebs' solution, GHB or GBL were administered to animals daring the early recovery period from 0.5 h hypoxic-oligemic exposure, the brain metabolic patterns of the right hemisphere indicated that GHB retarded the restitution of energy phosphates and the oxidation of the accumulated lactate; whereas, GBL led to a delayed metabolic deterioration. It is concluded that GHB and GBL do not beneficially alter cerebral energy metabolism during acute hypoxia-oligemia and that their administration during restitution may result In metabolic alterations which suggest an unfavorable effect.

ISSN:0039-2499    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

Tandem arteiiosclerotic lesions of the carotid sinus and siphon increase the risks of carotid endarterectomy; when tbe sipbon lesion is sererely stenotic, a microvascular bypass may be the preferable procedure. Two patients, each with severe siphon stenosis and significant sinus lesions, however, were subjected to carotid endarterectomy as their initial surgical procedure. The postoperative arteriogram showed resolution of the siphon stenosis in both patients. The identification of an associated extracranial lesion, or the presence of a lesion located more distal in the siphon than atheroma usually occur, should alert the surgeon that the intracranial obstruction may be due to embolism. In patients with these tandem lesions, therefore, a repeat arteriogram, performed several weeks after endarterectomy or sufficient medical treatment interval, may show resolution of the intracranlal lesion, and may avoid an unnecessary bypass procedure.

ISSN:0039-2499    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

A patient is reported who during vigorous back bleeding after unclamping of the internal carotid artery during endarterectomy had EEG slowing and a postoperative increase in neurological deficit. This phenomenon, an apparent steal, has not been reported and suggests that EEG monitoring Is as vital at unclamping as it U after clamping. The patient also raises questions about the risk of early endarterectomy for those who have persistent deficits, even with unobstructed vessels.

ISSN:0039-2499    

出版商:OVID    

年代:1980

数据来源: OVID