1. A homogeneous preparation of pig kidney diamine oxidase was obtained by polyacrylamide gel electrophoresis and immunodiffusion. Its molecular weight was estimated as 170,000 by Sephadex G-200 column chromatography and as 220,000 by SDS-polyacrylamide gel electrophoresis. After mercaptoethanol cleavage of disulfide bonding, the molecular weight of the subunit was 130,000. 2. Little contamination was observed in the preparation of human placenta by SDSpolyacrylamide gel electrophoresis and immunoelectrophoresis and the molecular weight was calculated as 300,000 and 280,000 by the extrapolation from the calibration curve of Sephadex G-200 column chromatography and SDS-polyacrylamide gel electrophoresis, respectively. The subunit was 170,000. 3. By immunodiffusion, immunoelectrophoresis and inhibition test of the enzyme activity using a heterologous antiserum, a good cross-reactivity was observed between the anti-human diamine oxidase serum and pig diamine oxidase. 4. The activities of the two enzymes were not almost inhibited by homologous and heterologous antisera.
Medical examination was performed on the divers in Ohura for 7 years from 1969 to 1972. Aseptic bone necrosis was found in 268 of 450 divers (59.5%). Men with over 5 years of experience in diving were highly affected (more than 54.4%). These bone lesions were found most frequently in the proximal end of the femur and the humerus. There was a significantly higher incidence of bone lesions in the men who dived over 30 meters. In the group of men with one or more bone lesions, 73.1% were known to have been treated for bends. The bone, once exposed to a certain compression of air, would have a tendency to develop bone lesions even after cessation of diving. Type A2 (linear opacity) led to the structural failure of the joint surface of the femur and the humerus. Histopathological study was carried out on the sections of bone obtained from three autopsy cases and four operated cases. Formation of air bubbles in the bone marrow cavity seemed to be the most important as the cause for the occurrence of aseptic bone necrosis, and local circulatory disturbance might be the most responsible for the progression of the bone lesion.
Since Langer published his work on the cleavage lines of the skin in 1861, many Japanese and foreign authors have referred to Langer’s lines as the most appropriate guides for skin incisions giving minimum scarring after heelings, but it has recently been suggested that the cleavage lines of Langer do not constitute a suitable guide for making an incision. Furthermore, comparison with directions of the lines described in the published textbooks has shown some discrepancies in detail among these descriptions, especially in the face. Therefore, Japanese cleavage lines were examined in the facial region of seven male and four female Japanese cadavers, and the following results were obtained. 1) Forehead: The long axes of the cleavage lines tend to run transversely as a whole. 2) Eyelids: The lines run, drawing a concentric loops, around the eye fissures. 3) Lips: The main direction of the lines on the upper lip is radial upwardly, and the lines radiate downward on the lower lip.
Repetitive cortical stimulation induced rhythmical masticatory jaw movement and masseteric nerve activity in cats with the spinal cord sectioned at the C2 level. Jaw depression alone did not induce any rhythmical jaw movement, but it turned the irregular jaw movement evoked by subthreshold cortical stimulation into the regular jaw movement as evoked by suprathreshold conical stimulation. The cortically induced rhythmical masseteric nerve activity could be induced even in immobilized condition and after cerebellectomy, although the rhythmical nerve activity was depressed in amplitude and the rhythm became slower than before immobilization. Tonic jaw depression after immobilization facilitated the tonic activity in the masseteric nerve and also induced a remarkable increase in the amplitude of the cortically evoked rhythmical nerve activity and a slight acceleration of the rhythm, leading to the same masticatory rhythm as before immobilization. It was concluded (1) that the cortically induced masticatory rhythm in cats is basically generated centrally and (2) that the tonic inputs from the muscle spindle in the jaw-closing muscles participate in the rhythm formation by supplying tonic excitatory inputs mainly to the jaw-closer motoneuron and also to the central rhythm generator.
An autopsy case of the hydranencephaly, which is a malformation of the brain, was presented. In spite of its rarity, it is emphasized that oral pathologists and surgeons should have a general knowledge of it, because of its close resemblance to hydrocephalus.
The effect of repeated intragastric administration of N-nitrosomethylurea on the molar gingival epithelium of the hamster was investigated both histologically and histoautoradiographically. Thickening and downward proliferation of the gingival epithelium were evident from the second month of the treatment, in the attachment epithelium and interdental epithelium. Subsequently, the apical part of the crevicular epithelium, epithelium of the oral aspect of the gingiva, and the marginal crevicular epithelium thickened. About three months after the beginning of the administration, thickening, hyperkeratosis, and downward proliferation of the gingival epithelium were widespread, and proliferated epithelial cell nests were parakeratotic, often assuming a structure of keratotic cyst, which invaded the periodontium, accompanied with compressive resorption of the alveolar bone and involvement of bone marrows. Cellular atypia appeared three months after the fast treatment, occasionally suggesting early malignancy. Epithelial proliferation was generally not accompanied with any distinct inflammatory change. In the autoradiographic analysis, it was clearly noticed that labeled cells had increased in each epithelial zone before the histological changes became evident. The results of the present experiment were discussed in reference to the pathogenesis of gingival carcinoma.