, Dong Been Park Animal models of peripheral nerve ischemia have yielded variable results.
The question of whether postischemia re-estableshment of blood flow to the nerves auguments injury has not been examined.
To study this question, the ipsilateral common iliac and femoral arteries were occluded with arterial snares for 3 hours in rats. C14-butanol tissue distribution was then used to measure blood flow in both sciatic and posterior tivial nerve trunks during occlusion and reperfusion.
Clinical limb function was graded serially, with the undisturbed contralateral limb serving as the study control. Nerve blood flow was reduced throughout the ischemic period and was only 20% of the control value in the posterior tibial nerve. All rats had functional impairment with an average limb function score of 7.5(normal score<2). During reperfusion period, blood flow in the distal sciatic and posterior tibial nerves was approximately double that of control nerbes at 2 hours.
At 21 hours, tibial nerve blood flow was still twice that of the control nerve, but flows in the distal sciatic nerve were unchanged from control levels. Clinically, limb function improved progressively after reperfusion.
It was concluded that nerve ischemia is attended by a relatively prolonged hyperemic flow response during reperfusion.
, Kyu Man Shin The purpose of this study is to investigate e effects of preischemic hyperglycemia on e alterations of'adenosine triphosphate and lactate concentrations in e acutefocal ischernic brain of the cats.
Acute focal cerebral ischemia in cats was induced by occlusion of the left middlecerebral artery through the postorbital technique. The experimental animals were divided into 3 goups: sham control, occlusion and recirculation groups. Each group was divided into 2 subgroups: normoglycemic and hyperglycemic groups.
The experimental results are obtained as fo11ows;
1) In normoglycemic subgroups of occlusion and recirculation proups, amount of adenosinetriphosphate in ischmic brain decreased significantly to 3.0% and 13.0% of the sham control,respectively(p < 0.001).
In hyperglycemic subgroups of occlusion and recirculation groups, amount of adenosine trisphosphate decreased a little more an at in normoglycemic subgroups, even so there wasno statistic significancy(p > 0.1).
2) In normoglycemic subgroups of occlusion and recirculation groups, amount of lactate inischemic brain increased signigicantly to 175.7% and 187.9% of the sham control, respectively(p < 0.001).
In hyperglycemic subgroups of occlusion and recirculation groups, amount of lactate increased nore than that in normoglycemic subgroups with statistic significancy(0.001 < p < 0.01).
These results suggest that hyperglycemia before ischemia serves to elevate glucose transport into brain tissue and thereby, to promote profound tissue acidosis throughanaerobic glycolysis caused by a failure of adenosine triphosphate stnthesis during the ischemicperiod.
The object of this investigation was to study the effects of Naloxone on histopathological changes in cats subjected thoracic cord contusion. Twenty cats were divided 4 groups : The first group was sham control(3 Cats). The second group was the impact group that was induced by T9 cord injury without treatment(6 Cats). The third group was the saline group that was induced by T9 cord injury and treatment with Saline(6 Cats). The fourth group was the Naloxone group that was induced by T9 cord injury and treatment with Naloxone(6 Cats). The histopathological evaluation of the injured spinal cords in Naloxone-treated Cats had less tissue damage than would be observed in time-matched standards. The histopathology in Saline-treated group had slightly better than typical of what we would expect in impact group.
, Kyu Man Shin The pathological lesion in spinal injury is usually more severe in the central gray matter and spreads centrifugally to surrounding white matter. Opiate antagonists, naloxone, by blocking the pathophysiologic effect of endorphins, should increase both mean arterial pressure and spinal cord blood flow and limit neurologic injury. Naloxone produce increase of lateral column blood flow and ameliorate the central gray matter ischemia. We have investigated to thoracic cord confusion. The spinal cord of naloxone-treated cats has less tissue damage than would be observed in time-matched standards.
This study was undertaken in order to define the beneficial action of methylprednisolone sodium succinate on the lactate metabolism in injuried spinal cord. The spinal cord was exposed by dorsal laminectomy from L2 to L5 under the operating microscope. A 400gm - cm injury was produced at the L2 vertebral level of the cord. The lactate content peaked at 2 ours of the injury, and remained significantly elevated for 8 hours compared to uninjuried normal cord. The changes of tissue lactate in the spinal cord following injury are consistent with marked reduction in blood flow in the injuried spinal cord tissue following blunt contusion trauma. The elevation in lactate observed at 1 hour, 2 hour and 4 hour after the injury were prevented by intravenous administration of single 30 mg/kg dose of menthylprednisolone at 30 minutes after the injury. The results suggest that the beneficial effect of the intravenous administration of a 30 mg/kg dose of methylprednisolone may improve blood flow to the injuried tissue of spinal cord.
Moyamoya disease is a cerebrovascular disease of unknown etiology, which is characterized by bilateral stenosis or occlusion at terminal portion of internal carotid artery and at proximal portion of anterior cerebral artery and/or middle cerebral artery and abnormal vascular network in the vicinity of the arterial occlusions. It occurs frequently in Asian countries, particularly in Korea and Japan, but is rare in Western countries. To establish the etiology of moyamoya disease, much about the pathology from autopsies, factors involved in its pathogenesis, and its genetics have been studied. It may occur at any age from childhood to adulthood and in general, initial manifestation is cerebral ischemic symptoms in children and intracranial hemorrhage symptoms in adults. Because it progress and cause recurrent stroke, early diagnosis and proper management has been recognized. Cerebral angiography is essential for definitive diagnosis and treatment plan. Magnetic resonance imaging/magnetic resonance angiography is useful for diagnosis and follow-up tools after revascularization. Evaluation of the cerebral hemodynamics by single photon emission computed tomography and positron emission tomography is useful for diagnosis and assessment of the severity of cerebral ischemia in moyamoya patients. Surgical revascularization is effective for moyamoya disease manifesting as ischemic symptoms, to prevent further ischemia and infarction. In hemorrhagic type moyamoya disease, revascularization can be considered. Direct bypass, indirect synangiosis and combined methods are used. Outcomes of revascularization are excellent in preventing transient ischemic attacks in most patients.
Citations
, Si Hoon Park, Hee Jung Oh Coronary artery-to-left ventricular fistula is an unusual anomaly in adult and consists of a communication between one of coronary arteries and cardiac chambers. Most patients with coronary artery to ventricular fistulae are usually asymptomatic, but some can suffer from anginal pain. which can be caused myocardial ischemia due to coronary steal mechanism. In absence of concomitant atherosclerotic coronary artery disease or left ventricular hypertrophy causing an oxygen demand-supply imbalance, coronary steal appears to be a major importance in pathogenesis of myocardial ischemia in cases with generalized arterial systemic fistulae. We experienced 2 incidently found cases of coronary artery-to-left ventricular fistulae. We report these cases with a review of literature.
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