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AbstractWe found that diisopropylamine dichloroacetate (DADA), known as a vasodilator, enhanced growth of keratinocytes in 4 days culture at 1–30 μg/ml, and such promoting effects of cell proliferation were reconfirmed by measuring DNA synthesis using [3H]thymidine incorporation. On the other hand, this substance enhanced synthesis of keratin K1, a potent marker of differentiation in keratinocytes, at 1–100 μg/ml in low calcium (0.1 mM) or high calcium medium (1.25 mM). Moreover, the formation of cornified envelope, another potent marker of differentiation in keratinocytes, was also promoted by DADA at a concentration of 0.1–10 mMwhich includes valid concentration of DADA for the enhancement of keratin K1 formation (1–100 μg/ml: 0.05–0.5 mMDADA). These results indicate that DADA has a double function, enhancement of both proliferation and differentiation of cells, which could be linked to the turnover of skin epidermis. Furthermore, in order to analyze the effect of DADA on keratinocytes, we examined the effects of each component of this substance, diisopropylamine (DIA) and dichloroacetate (DCA), on keratinocytes. As the result of these investigations, evidence was found that DCA was effective on enhancement of cell growth, but DIA was ineffective. Moreover, we found that DCA was effective on keratinocyte differentiation by evaluating the enhancement of a differentiation marker, formation of cornified envelopes, within 10 mM, while DIA was not effective. Therefore, we concluded that only DCA was an active component of the DADA molecule for the proliferation and the differentiation of keratinocytes in vitro.

Summary: A case of progressive systemic sclerosis associated with colonic involvement is described. Barium-enema examination revealed segmental involvement. Colonoscopic examination of the whole range of the involved colon revealed wide-mouthed diverticula with interspersed rigid areas and numerous ulcerations. These colonoscopic findings appeared to be distinct from those associated with tuberculosis and Crohn's disease.