In 6 cats, cerebral infarction was produced by transorbital occlusion of the left middle cerebral artery (MCA). Five animals developed typical cortical infarcts. Eight weeks later, cerebral blood flow (CBF) was determined by 14C-iodoantipyrine autoradiography and the number of intact neurons was counted histologically. Two non-operated cats served as controls. Cortical blood flow in the infarcted hemisphere was reduced by 24.6-74.4% when compared to the flow in the contralateral cortex and in controls. Averaged white matter flow was decreased by 39.1%. Regional cortical flow was gradually reduced from parasagittal regions towards the infarct. In the surrounding of the infarct, cortical perfusion was decreased to 24.8 +/- 9.7 ml/100 g/min, i.e. 19.7% of contralateral flow. Although the infarcts were sharply demarcated macroscopically, the number of cortical neurons decreased gradually from the midline to the peri-infarct zone. A significant linear correlation was found between absolute CBF-values and the number of neurons in areas of the infarcted hemisphere. The homolateral gyrus lateralis had normal neuronal density but flow was reduced by 20%. These findings suggest that the blood flow reduction in tissue surrounding chronic infarcts is due to neuronal cell loss and to functional inactivation caused by damage of afferent fibers.

In experimental RG1 2.2 glioma of rat brain, local blood flow, glucose utilization, protein synthesis, glucose and ATP content were measured by means of triple tracer autoradiography and bioluminescence technique, respectively, to determine hemodynamic and metabolic thresholds for local tumor energy failure. Perfusion thresholds were estimated at tumor blood flow values of 69.0 +/- 0.1 ml/100 g/min (estimate +/- standard error) and of 69 +/- 7.1 ml/100 g/min for the beginning of the decline in regional ATP and glucose content, respectively. Metabolic thresholds were derived at tumor glucose utilization values of 70.6 +/- 8.3 mumol/100 g/min for reduced protein synthesis, of 55.0 +/- 0.2 mumol/100 g/min for the decrease in glucose content, and 34.7 +/- 4.7 mumol/100 g/min for decline in ATP content. Our results suggest that blood flow limits glucose supply to tumor tissue at much higher flow rates than in normal brain which, in turn, is associated with a decrease in tumor glucose utilization. A reduction and not an increase in tumor glucose availability could be a more appropriate strategy for the induction of energy failure in tumors.

No abstract

No abstract

The border of a chronic infarct is sharply demarcated. We found in our investigation, however, that this is merely a macroscopic diagnosis and does not say anything about the structure of the tissue and the content of morphologically preserved neurons in the marginal zones. In six cats the left cerebral artery was permanently occluded. Eight weeks later the animals were killed and autoradiographic investigations were conducted on cryostat sections to determine rCBF. Adjacent to every 20-microns section, a 10-microns HE section was prepared. Preserved nerve cells were counted in several areas of the cortex in a symmetric fashion in both the infarcted and the contralateral side in the identical regions where rCBF had been measured in the preceding section. Two additional non-ischemic cat brains served as controls, which were investigated in the same manner as described above. A marked loss of neurons was observed in the border zone of the infarct. Only occasionally preserved ganglion cells were seen in each cortical layer. Even in areas one gyrus distant to the margin of the infarct the number of neurons was still reduced by one third as compared to the contralateral side. Starting only with the lateral gyrus the number of ganglionic cells was found to be equal on both sides.

No abstract

No abstract

Spontaneous cerebellar haemorrhage accounts for 10% of all intracranial spontaneous haematomas. It is a disease which principally affects patients over middle age, and it is rare in childhood. To twelve cases previously reported we now add a further three. Attention is drawn to the diagnostic difficulties and the values of echoencephalography, angiography, and computerized axial tomography in diagnosis and localisation of the condition. Prognosis can be good even in cases in poor condition of diagnosis and treatment are prompt.