摘要:

Forty patients were studied by computerized tomography and by radionuclide brain imaging. The final diagnosis was infarction in 29 patients, intracerebral hematoma in seven, acute SAH in one, and old cerebrovascular accidents in three. CT was far superior to RN in detecting intracerebral hematomas and distinguishing them from cerebral infarction. The results of CT and RN tests were comparable regarding the percentage of abnormalities. However, the results in the same patients were not identical in 55% of the cases, indicating a complementary role for the two tests. There was no relationship between the frequency of abnormalities on CT and the time lapse afte the onset of cerebral infarction. RN uptake was not seen in patients with old cerebrovascular accidents.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

To elicit evidence concerning neurogenic control, regional cerebral blood flow determined by measurement of cortical temperature was examined in monkeys. Following three hours of temporary occlusion of the MCA, pressure autoregulation was preserved in all control animals. Presumptive partial chemical sympathectomy, produced by the administration of either L-alphamethyl- tyrosine or 3-alpha-dimethyl-tyrosine methyl ester HCI, was associated with loss of pressure autoregulation following 1.5 hours of occlusion of the MCA on only the side of the occlusion. Failure of pressure autoregulation in the treated animals implies that sympathetic control was a partial requirement of proper postischemic pressure autoregulation.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Diazoxide failed to safely relieve cerebral vasospasm by intracisternal injections in dogs and by intracarotid injections in monkeys despite in vitro documentation of arterial relaxation with this agent. Administration of the drug frequently produced hypotension and, in the presence of vasospasm, was associated with a high mortality rate.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

A new model for studies on atherogenesis in the cerebrovascular system was obtained by using recently established strokeprone spontaneously hypertensive rats (SHRSP). SHRSP on a hypercholesterolemic diet (20% suet, 5% cholesterol, and 2% cholic acid) had ring-like fat deposits in the circle of Willis, which were detected within a few weeks by new techniques for the macroscopical demonstration of fat deposits "as a whole" and were proved to be good quantitative indices for the initiation of atherogenesis. Experimental studies using more than 200 rats including SHRSP, experimental hypertensive rats (renal infarction hypertension) and WK rats, fed a hypercholesterolemic diet with 1% salt in the drinking water for 1 week, 2 weeks, 10 weeks and more than 10 weeks, revealed that the arterial fat deposition in the brain was affected by BP, serum cholesterol level, strain difference and age. High BP was confirmed to be more important than the other factors by the quantitative analysis of sudanophilic rings in relation to BP.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Acute changes in the redox state of NADH in the cerebral cortex of cats were investigated following occlusion of the middle cerebral artery (MCA) and were correlated with alterations of regional cerebral blood flow in the ischemic cortex determined autoradiographically. Arterial occlusion was accomplished via the transorbital approach. Cortical fluorescence and reflected light signals were recorded from the central MCA territory by means of a beam-splitting fluorometer, and a fluorescence signal corrected for alterations in intravascular hemoglobin was derived. Following arterial occlusion, there was a rapid increase in cortical NADH fluorescence, peaking within 30 to 70 seconds at 20% to 40% of full scale. This was followed by a slow linear decline in fluorescence over the next several minutes. The behavior of cortical NADH fluorescence was unaffected by replacement of the ambient air over the cortical surface with nitrogen. Mean regional blood flow values in the most ischemic gyri two to 15 minutes following arterial occlusion were 21% to 23% of the corresponding values in the opposite, nonischemic hemisphere. In individual animals, peak NADH fluorescence values following arterial occlusion correlated with the extent of blood flow reduction in the affected ischemic gyri (P < 0.05).

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

The distribution of regional cerebral blood flow (rCBF) within the cerebral hemispheres of rats was investigated following an hypoxic-ischemic insult consisting of a 30-minute exposure to 6.5% to 7% inspired oxygen coupled with unilateral ligation of the common carotid artery and maintenance of normal blood pressure (modified Levine preparation). rCBF was estimated by means of an autoradiographic method employing „C-antipyrine. Mean arterial Po2values of 26.8 to 27.5 mm Hg were attained during the insult period. rCBF rose above control values in all structures of the hemisphere contralateral to carotid artery ligation. Structures of the hemisphere ipsilateral to arterial ligation exhibited rCBF values less than those of the opposite side. However, the degree to which carotid artery occlusion reduced the rCBF of a structure relative to that of the opposite hemisphere varied greatly from region to region, with the greatest decrements occurring in the lateral cerebral cortex and the caudoputamen. Previous studies in this model have shown that these regions of the hemisphere ipsilateral to carotid artery occlusion are zones of frequent histological injury. These data suggest that inhomogeneities of rCBF may in part determine the phenomenon of „selective vulnerability” of the nervous system to hypoxia-ischemia.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

SUMMARY Thirty-one patients with acute cerebral infarction were treated with the thrombolytic agent urokinase for either a single or a double infusion period, each of ten hours. The effects of urokinase therapy administered at dosage rates of 1,200, 1,500 or 1,700 CTA urokinase units per pound of body weight per hour were followed by serial blood coagulation and other biochemical studies. In the dosage used, urokinase produced a prompt sustained increase, 20-fold to 40-fold, of plasma thrombolytic activity with relatively minor disturbance of the blood coagulation system. Nevertheless, hemorrhagic complications occurred in several patients and distinctly favorable therapeutic effects were not observed.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Four patients undergoing urokinase infusion therapy for acute occlusive cerebrovascular disease had intracerebral hemorrhage in the ischemic hemisphere. Three patients died during the acute phase of their illness and an autopsy was performed on two. The pathogenesis of cerebral bleeding in these case reports is discussed.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Continuous measurements of systemic blood pressure (BP), cerebral perfusion pressure and CBF were accomplished in the cat during transient hypertension, hypercapnia and bilateral carotid artery occlusion. From these measurements resistance values in the circle of Willis and in the cerebral arteries distal to the circle were calculated. The results indicate that the arteries of the circle of Willis and the arteries distal to the circle of Willis dilate and contract independently.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

The degree of recovery of the somatosensory cortical evoked response following a period (15 to 65 minutes) of partial ischemia, produced by temporary occlusion of the middle cerebral artery (MCA), was assessed in baboons and related to the local tissue blood flow and Pth before, during and after the occlusion. Flow was measured using the technique of two-minute hydrogen clearance. Failure of complete recovery of the evoked response was associated with significantly greater depths of ischemia and tissue hypoxia during occlusion, and with significantly greater and persisting tissue hypoxia after occlusion, than complete recovery. Complete recovery of the eioked response also was associated with tissue hyperoxia after occlusion. The reduced postocclusive Po2 levels associated with incomplete recovery of the evoked response suggest that reduced perfusion during ischemia was sufficiently severe to cause some degree of irreversible anoxic damage. The effect of a brief (three to ten minutes) period of ventilation with air (instead of oxygen) under such low-now conditions was to depress the evoked response significantly further; normally perfused brain, however, was unaffected by this procedure. This finding has clinical implications in regard to normobaric oxygen therapy.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID