Hepatocyte growth factor is a predominant chemoattractant for gingival epithelial cells produced by radicular cyst-derived fibroblast-like cells.

To clarify whether fibroblasts could be involved in the pathogenesis of periodontal pocket formation, the chemotactic activity of radicular cyst-derived fibroblast-like cell (RCF)-conditioned medium (RCF-CM) for gingival epithelial cells was examined using a modified Boyden chamber assay. RCF-CM possessed significant chemotactic activity, which was decreased markedly by treatment with anti-human hepatocyte growth factor (HGF) antibody. Furthermore, the chemotactic activity of RCF-CM was well correlated with HGF content. These results show that the RCF secrete an HGF-like factor, and suggest that such a factor derived from periodontal fibroblasts might play a role in epithelial apical migration in periodontitis.

[Head injury in children--with special reference to CT findings (author's transl)].

Findings of computerized tomography (CT) in 183 cases of head injury in children were investigated with special reference to CT findings of mild head injury. As was expected, CT findings of mild head injury fell within the normal range, in almost all cases. However, abnormal findings were noticed in 4 out of 34 cases (12%) in acute stage and 7 out of 76 cases (9%) in chronic stage. They were 3 cases of localized low density area in acute stage and 6 cases of mild cerebral atrophy in chronic stage, etc. There were some cases of mild head injury in which CT findings were normal while EEG examination revealed abnormality. Also in some cases, x-ray study demonstrated linear skull fracture which CT failed to show. These conventional techniques could be still remained as useful adjunct aid in diagnosis of head injury. CT findings of cases of cerebral contusion in their acute stage were divided as follows; normal, low density, small ventricle and ventricular and/or cisternal hemorrhage, frequency of incidence being 38, 17, 22, 11% respectively. These findings were invariably converted to cerebral atrophy from 10 days to 2 months after the impacts. In the cases with intracranial hematoma revealed by CT, only 32% of them showed clinical signs of Araki's type IV in their acute stage and 63% of them showed no neurological defects, that is Araki's type I & II. A case of extreme diffuse cerebral atrophy which followed acute subdural hematoma caused by tear of bridging veins without cortical contusion was presented.