Berberine-induced morphologic differentiation and down-regulation of c-Ki-ras2 protooncogene expression in human teratocarcinoma cells

A pluripotent human teratocarcinoma cell clone, NT2/D1, which was derived from the Tera-2 cell line, was induced to differentiate into cells with neuronal cell morphology by treatment with berberine. As early as 1 day after a 24-h treatment of cells with berberine at a non-toxic dose of 0.1 mg/ml in culture medium, the cells started to show morphologic changes, developing into terminally differentiated neuronal cells with long, inter-connecting network-like cellular structures. This process is much faster as compared with that induced by treatment with retinoic acid (RA), which took at least several days to develop. Unlike RA, berberine could not induce murine teratocarcinoma cell line, F9, to differentiate into endodermal cells. It was also found that, although the NT2/D1 cell clone exhibited amplification and enhanced mRNA expression of c-Ki-ras2 gene as did the parent cell line, a marked down-regulation of c-Ki-ras2 mRNA expression was observed. However, there was no change in actin mRNA expression even after differentiation had occurred. Thus, morphologic differentiation of teratocarcinoma cells into neuronal cells is found to be associated with down-regulation of a protooncogene which plays some definite role in oncogenesis. The mechanism by which berberine induces differentiation in these cells needs further investigation.

[Clinical pathological analysis of recurrent oral ulcer and Behçet's syndrome]

Histopathological features of 53 cases of recurrent oral ulcer (ROU) and 28 cases of Behçet's syndrome (BS) were studied. The findings of light microscopic examinations are as follows: (1) The inflammatory cell reactions in early lesions are characterized by predominant lymphocytes and monocytes which differ from those in later lesions. (2) The vascular lesions are more significant in BS than in ROU. (3) The number of mast cells in the oral lesions of BS is more than that in ROU and controls. (4) Bacteria are observed in 11 specimens stained with HE and multinucleated epithelial giant cells are found in one specimen. It is considered that the lymphomonocytes in epithelial layer may play a role in the destruction of the epithelial cells through autoimmunization.

[Long-term results of the treatment of mandibular condyle fracture]

Long-term result of conservative and surgical treatment of varying types of mandibular condyle fracture in 34 cases was investigated. The study shows that 90% cases of condyle fracture, including that complicated with dislocation and displacement, could be successfully treated with simple immobilization by intermaxillary elastic bands. The long-term result of close reduction is closely related to the interval between the trauma and the start of treatment, the earlier the beginning of the treatment, the better the result. The unfavourable immediate result in form of imperfect occlusion and excursion, etc. could be corrected by forced mandibular movement. 10 cases complicated with badly dislocation or communicated fracture were treated with condylectomy, satisfactory results were achieved in 80% of them.