摘要:

The scanning electron microscope (SEM) has been employed to study the effects of ischemia on the luminal surface of the common carotid artery. Fifteen adult rabbits were lightly anesthetized and the common carotid arteries surgically exposed. The right carotid artery was occluded with a single Heifetz clip for five minutes (five animals), 15 minutes (five animals), and 30 minutes (five animals). Following removal of the clip, the animals were immediately perfused with glutaraldehyde and the arteries excised and prepared for critical point drying. Four additional rabbits were perfused following the same method with no surgical procedures performed in the neck. Normal aortas were also examined. The nature and frequency of endothelial cell alterations were determined by analysis of ten randomly selected SEM fields. Examination of the endothelial surface of arterial segments distal to the occluding clip revealed the presence of numerous “crater-like” defects as well as outpouchings or “balloons.” The numbers of craters and balloons were significantly increased in the ischemic (distal) arterial segment as compared to either proximal or sham-operated control segments (P < 0.001). These endothelial cell alterations were never observed in random micrographs of arterial segments taken from unoperated control animals, but were seen at the ostia of some intercostal arteries of the aorta. It is suggested that these craters and balloons could cause interference with blood flow and the for mation of platelet thrombi by their protrusion into the lumen, as well as alteration of the permeability of the arterial intima.

ISSN:0039-2499    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

Fifty-two stroke patients, 43 with cerebral ischemia and nine with cerebral hemorrhage, underwent continuous cardiac monitoring in an Intensive Stroke Care Unit shortly after the onset of the acute cerebrovascular accident. In the group of patients with no evidence of pre-existing heart disease, eight of 18 with cerebral ischemia and five of seven with hemorrhage developed ECG abnormalities. Additional ECG changes were noted in 21 of 25 patients with cerebral ischemia and two of two with hemorrhage who were known to have previous heart disease. Both disturbances in rhythm and conduction and “ischemic” ST-T alterations were detected and the frequency of the former exceeded that of the latter. The ECG alterations were transient in 32 patients and permanent in four. New electrocardiographical abnormalities in patients without evidence of heart disease prior to the stroke were associated with poorer prognosis. The pathogenetic mechanisms leading to the appearance of cardiac abnormalities in stroke patients are considered.

ISSN:0039-2499    

出版商:OVID    

年代:1974

数据来源: OVID

ISSN:0039-2499    

出版商:OVID    

年代:1974

数据来源: OVID

ISSN:0039-2499    

出版商:OVID    

年代:1974

数据来源: OVID

ISSN:0039-2499    

出版商:OVID    

年代:1974

数据来源: OVID

ISSN:0039-2499    

出版商:OVID    

年代:1974

数据来源: OVID

ISSN:0039-2499    

出版商:OVID    

年代:1974

数据来源: OVID