ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

A system is presented for the classification of experimental models of cerebral ischemia by a mechanism of induction and distribution of the cerebral insult. Application of the proposed system to the scientific literature may help to resolve apparent conflicts in experimental findings and establish a frame of reference upon which to estimate the relevance of specific animal data to clinical phenomena. Experimental ischemic lesions and pathophysiological states must be considered the net product of variables in etiology and distribution of ischemia in the species chosen under the specific anesthesia selected.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

An ocular pneumoplethysmograph was devised to measure the systolic pressure in the ophthalmic artery and to obtain calibrated pulse volume changes from the ocular globe, with simultaneous recording from both eyes. The instrument is selfcontained and portable. It can be applied by paramedical personnel, and the graphic recording is readily interpreted by the physician. It has proved to be 100% accurate in noninvasively detecting unilateral carotid occlusion or preocclusive stenosis. This technique, when combined with carotid compression, has been shown to be most valuable in assessing the tolerance of a cerebral hemisphere to proximal carotid occlusion. It was used to evaluate a wide variety of carotid arterial lesions. Elective carotid resection without graft replacement and urgent and elective carotid ligations were performed, based on the preoperative prediction that such procedures would be tolerated without neurological injury. The instrument and the technique of its application are simple, safe, and accurate.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

The interrelationships between cerebral edema, intracranial pressure (ICP), and cerebral blood flow (CBF) were studied in acute and chronic triethyl tin sulfate treated rats. Prior to pentobarbital anesthesia behavioral observations were made. ICP and regional CBF were measured under steady state conditions and brain water content was determined by vacuum drying of the right cerebral hemisphere. Control and chronic animals were neurologically normal.There were two distinct acute groups: (1) acute low pressure (ALP) animals - alert but tetraparetic, and (2) acute high pressure (AHP) animals - deeply stuporous, with minimal pain response and gross EEG slowing. ICP was significantly elevated only in AHP animals. Hemispheric CBF was significantly reduced in AHP and chronic animals. The interaction of increased pressure and edema (AHP) produced the greatest decrease in CBF, although deep white flows were significantly affected in all experimental groups. Chronic animals had significantly lower flow in four of seven regions compared to ALP animals despite no significant difference in ICP. Water content was significantly increased in all experimental groups with the greatest increase in the chronic animals.In the absence of any significant increase in ICP, cerebral edema appears to cause a significant reduction in cerebral blood flow and this reduction corresponds with the magnitude and location of the edema.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

The fine structure of the microvasculature in areas of focal cerebral ischemia was studied in squirrel monkeys and the changes in areas of impaired and unimpaired microvascular filling, as defined by carbon perfusion, were compared. Microcirculatory obstruction became evident three hours following middle cerebral artery (MCA) occlusion and appeared to be partly the result of compression of capillaries by perivascular glial swelling and developing cerebral edema. Slight endothelial swelling was a common finding. Intraluminal membrane-bound bodies were occasionally identified but they did not appear to be producing significant obstruction. The tight endothelial junctions remained intact and there was no evidence of accelerated micropinocytosis. Severe neuronal injury frequently preceded the development of the microvascular obstruction and was more widespread than the zones of impaired perfusion.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

A new angiographical classification of primary intra* cerebral hemorrhage is presented.We have clarified the predilection sites of intracerebral hemorrhage and the advancing direction of the hematoma by studying autopsy cases. Furthermore, we tried to detect the presence or absence of destruction of the internal capsule and ventricular ventricular rupture by means of angiography. Our classification, introducing the idea of dynamic changes of hematoma advancement from localized to advanced type, can be applied to clinical practice. This classification, along with the patient's level of consciousness, is felt to be the most important indication for operation.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

The Mg+ + requiring adenosine triphosphatase (ATPase) associated with neuronal synaptic vesicles is extremely vulnerable to ischemia. After five minutes of ischemia both the maximum velocity and the substrate binding capacity of the enzyme were decreased. Results also indicate that these changes are related to the rapid intraneuronal lactic acidosis accompanying Ischemia. Ischemia was simulated by 37°C incubation of gerbil brain after decapitation. According to a recent hypothesis this enzyme plays a key role in exocytotic neurotransmitter release. Therefore, any inhibition of the ability of this enzyme to function would result in a drastically reduced capacity for transsynaptic impulse propagation.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Analysis of death certification in North Carolina for a three-year period, 1969 through 1971, showed regional differences in mortality rates from stroke in white men, with the highest rates in the Plains (tobacco growing and farming) area and the lowest rates in the Mountain region. These geographic differences in death rates were observed in all but the youngest age decade and also in the various types of stroke, i.e., hemorrhagic and occlusive cerebrovascular diseases. This regional variation in mortality, however, was not present in white women or blacks. The prevalence at death of heart disease, hypertension and diabetes also was higher in the Plains than in the Mountain region, suggesting that the observed geographic variation of stroke mortality is related to one or more of these major risk factors. It is concluded that the geographic differences in stroke mortality, which had been reported during previous decades, are real and are not due to variations in death certification, errors in diagnosis, or other explanations that might artificially produce inaccuracies in vital statistics.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

The predilection sites of cerebrovascular lesions (cerebral hemorrhage and/or softening) were studied in 1,278 strokeprone spontaneously hypertensive rats (SHRSP). The precise supply to the main cerebral arteries was determined by trypan blue injections and microangiography. The three major territories were the anteromedial cortex, the occipital cortex, and the basal ganglia. A common angioarchitectural characteristic of these three areas was the blood supply through "recurrent branching" from the main stream. In the basal ganglia, where there is a preponderance of lesions, the arteries responsible for these lesions belonged to the lateral group of lenticulostriate arteries. The primary pre-stroke arterial lesions were further studied microangiographically in SHRSP killed at the time the initial symptoms of stroke were detected. These points were located at the "boundary zone" of the main cerebral arteries. Our findings indicated the importance of these two angioarchitectural minor loci as the basis for functional or organic circulatory disturbances that may cause stroke. Since these local factors of stroke are common in the cortex and basal ganglia of rats and basal ganglia of humans, these SHRSP are regarded as good pathogenetic models for studies on stroke in humans.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

A pathological examination was performed on normotensive rats (NTR) and spontaneously hypertensive rats (SHR) following bilateral common carotid artery ligation. After ligation, diffuse and extensive cerebral infarcts in the carotid artery territory occurred frequently in SHR, while NTR occasionally had wellcircumscribed small infarcts.The posterior communicating arteries, which are the major anastomotic channels connecting the carotid and vertebrobasilar systems, did not show any anomalies and were well developed in SHR and NTR. Vascular changes secondary to hypertension, such as fibrinoid necrosis or thickening of the wall, were not observed in SHR. Because of the paucity of structural difference of the blood vessels, the more diffuse and extensive cerebral infarcts in SHR after carotid occlusion were attributed to the hemodynamic difference rather than the morphological difference between the two groups.The results of the present experiment suggest that hypertension per se, i.e., hemodynamic factors, may be operative for the development of cerebral infarction.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID