A new cell line, designated as HSC-5 and derived from human skin squamous cell carcinoma (SCC), has been established in vitro and maintained proliferative in continuous tissue culture for over two years. The cells grow in a monolayer in vitro and have anaplastic epithelioid features. The doubling time was about 35 hr at the 30th passage. Chromosome analysis showed hypotetraploidy with a modal number of 76. A trial of transplantation of the cultured cells into nude mice was not successful. Analysis of cytokeratins from HSC-5 by two-dimensional gel electrophoresis revealed polypeptides No. 5, 8, 13, 18 and 19. The cell line is available to other investigators.

We have examined cytokeratins from stratum corneum (s. corneum) of the palm and back of hands by biochemical techniques which characterize cytokeratin No. 9 (CK9). By two-dimensional gel electrophoresis, cytokeratins from s. corneum of the palm (PSC) were resolved into three spots (designated as CK-A, CK-B and CK-C by us), and cytokeratins from s. corneum of the back of hands (BSC) were resolved into two spots (CK-A and CK-C). The results of polypeptide mapping and the spot positions in two-dimensional gels suggest that CK-A, CK-B and CK-C are degraded products derived from CK1/2, CK9 and CK10/11 in living keratinocytes of epidermis, respectively. While the spots of CK-A and CK-B were prominent and the spot of CK-C was very weak in PSC, the spots of CK-A and CK-C were prominent and the spot of CK-B was not detected in BSC. In filament reconstitution in vitro, cytokeratins from PSC formed intermediate-sized filaments similar to those commonly observed using cytokeratins from whole epidermis. In contrast, cytokeratins from BSC formed only short filaments and small granules. In order to examine this difference in detail, polypeptides were eluted electrophoretically from gel slices containing spots. Addition of eluted CK-B to cytokeratins from BSC promoted the formation of intermediate-sized filaments similar to those from PSC. Furthermore, although the mixture of eluted CK-A and CK-C did not form intermediate-sized filaments, the combination of CK-A and CK-B alone did form them.(ABSTRACT TRUNCATED AT 250 WORDS)

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Nine mutant strains defective in flocculating abilities were derived from the flocculating parent Pseudomonas strain C-120. Mutations in flocculating ability did not influence the rate and extent of cell growth. Amongthem, six strains which did not form floes at all completely lacked DNAbinding activity. Other mutant strains formed floes to a lesser extent as compared with the parent. Cell envelopes and SDS-extracted envelopes prepared from the parent strain, but not from nonflocculating mutant strains, held DNA-binding activities, indicating that DNA-binding activities of cell envelopes and SDS-extracted envelopes represented that of the wild type cells responsible for flocculation. DNA-binding activities of cell envelopes were abolished by treating with proteases, suggesting that the DNAbinding factor is a proteinaceous component. Susceptibility of DNAbinding activities of SDS-extracted envelopes to 2,4,6-trinitrobenzene sulfonic acid or at high temperatures supported this assumption. Although cell envelopes prepared from the parent cells and mutant cells were subjected to SDS-polyacrylamide gel electrophoresis, no differences in protein composition were observed. Pseudomonas strain C-120, which was isolated from activated sludge, flocculates spontaneously after the late logarithmic growth phase, and floes are rapidly and completely deflocculated by treatment with added deoxyribonuclease (DNase).1) In a previous paper,2) we showed that the component responsible for flocculation was extracted from floes by treatment with 3m guanidine hydrochlo

An 82-year-old Japanese woman had numerous palmoplantar keratotic plugs and pits, resembling 'music box spines'. Histological examination revealed compact columns of parakeratosis in the horny layer. Ultrastructually, the affected stratum corneum contained numberous variable-sized pyknotic nuclei, and cells in the stratum granulosum contained fewer keratohyalin granules. Autoradiographic analysis by [3H]thymidine [3H]TdR incorporation into epidermal cells of affected skin slices in organ culture revealed that only basal cells below the keratotic plug were stimulated to proliferate. Two-dimensional gel electrophoresis revealed that palmar keratotic plugs contained the keratin filaments that are specifically present in the plantar viable epidermal layer, or other hyperproliferative epithelial cells.