The kinetic and pharmacological characteristics of3H-spiroperidol binding sites were studied in slide mounted sections of rat forebrain, and optical binding conditions were defined. Using the receptor macroautoradiographic techniques with tritium-sensitive LKB sheet film, the distribution of dopamine (D2) receptor was determined in slices including striatum of rat brain. The autoradiograms were analyzed using Video Digitizer System combined with video camera and minicomputer, and the subtraction images were obtained. These studies suggest that this quantitative receptor macroautoradiography might be useful in the explanation of etiology in the field of neuro psychiatric diseases and the fundamental studies of positron emission computed tomography, since this method has several advantages over in vivo autoradiography and in vitro receptor assay.
Twenty-one patients with cerebrovascular disease (5 with hemorrhage, 10 with infarction, 2 with TIA, 4 with motor disturbance of unknown cause) were studied using N-isopropyl-p- (123I) iodoamphetamine (123I-IMP) and single photon emission CT. In 3 of 5 cases with cerebral hemorrhage, perfusion defects were shown in and around the region o f hematomas, furthermore, one o f the cases with internal capsular hematoma, the perfusion defect extended to the cortical area corresponding to the neurological pathway. In one case with MCA infarction, the perfusion defect was greater and clearer than the low density area on X-ray computed tomography (CT) . These results reveale the123I-IMP study provides physiological information in contrast with X-ray CT which provides anatomical information. In 3 of 9 cases with multiple small deep hemispheric infarctions on X-ray CT, the perfusion to the basal ganglia was suspected to be decreased on123I-IMP images. However, this visual findings was not definitive and, in fact, the diseased side was not always consistent with the clinical findings. For quantitative analysis, symmetrical regions of interest (ROIs) were constructed both basal ganglia and the ratio of average counts over the ROI to those over the whole slice was calculated. In the small infarction group, the mean±GS.D. of the values was 0.89±0.09 in right and 0.89±0.08 in left. Although the values were not significantly di, Jerent from those of normal subjects (0.99±0.02 in right, 0.97±0.03 in left), they distributed in the range less than normal in 5 of 9 cases. This method was thought to be useful and practical to evaluate the cerebral blood flow in basal ganglia of patients with deep hemispheric infarction.
Three kinds of firebricks infiltrated with litium hydroxide or carbonate were irradiated with neutrons and the liberation of tritium on heating the firebricks was investigated by using gas and liquid scintillation technique. Tritium produced by6Li (n, a) 3Hreaction was almost quantitatively recovered as tritiated water; the recovery was found to depend on porosity of firebricks. The liberation curves of tritium from the firebricks were more complicated than those from lithium hydroxide and carbonate.
It was found that p-nitrophenylacetylene polymerizes in chlorinated hydrocarbons by γ-ray irradiation, while it does not polymerize in the solid state, nor in the oxygen-containing organic solvents. The rate of polymerization in methylene chloride at 25°C was approximately proportional to the intensity of γ-ray, and the value of the apparent activation energy for the polymerization was negative. These results can be explained on the assumption that the polymerization in the chlorinated hydrocarbons is initiated by cationic species. The results obtained from the mass spectrometry of the monomer are consistent with the above assumption. The molecular weight distribution, the d.c. conductivity, and the UV-visible spectra of the polymers were measured.