Learn More
BACKGROUND Previous studies have described apoptosis in the stratum granulosum and in the stratum corneum, but not in the germinative compartment in normal skin. In psoriasis, an increased epidermal apoptosis has been observed in the differentiated compartment, suggesting that apoptosis has a key role in the pathogenesis of psoriasis, as a counteracting(More)
In human epidermis, germinative cell production is determined by three parameters: the cell cycle time, the loss of cycling cells by programmed cell death and the proportion of keratinocytes actively engaged in the cell cycle or growth fraction. The last parameter is still a subject of debate as the identification of a proliferative cell with certainty is(More)
Using an in vitro double labeling technique with two different levels of 3H-thymidine, the duration of the phase of DNA synthesis (S) and the labeling index (LI) were measured in the colorectal mucosa of three groups of patients: patients with colorectal neoplasms (adenomas and/or adenocarcinomas), patients with inflammatory bowel disease, and a control(More)
BACKGROUND The size of the germinative growth fraction (i.e. the number of actively proliferating germinative cells) of normal human epidermis is still a subject of debate. Ki-67 antigen and PCNA, an auxiliary protein of d-polymerase, are considered as markers of the growth fraction when used under optimal conditions. METHOD In the present work, we have(More)
Human keratinocytes grown at an air-liquid interface on dead de-epidermalized dermis exhibit a pattern of organization similar to that seen in vivo. Cell renewal is limited to the basal layer. The cell cycle time determined after 7 days of culture, using a percentage labelled mitoses (PLM) technique, was about 15 h. This result is comparable with published(More)
A mathematical model of cell renewal in epidermis is proposed for describing how psoriatic lesions might develop, based on available cell kinetic data for normal and psoriatic epidermis. Our simulations clearly demonstrate that an increase in the turnover rate in the germinative cell population cannot alone induce the typical psoriatic tissue architecture(More)
Paraffin sections from animal or human tissues fixed in different fixatives were submitted to immunostaining with the mouse monoclonal antibody 19A2, developed by Ogata et al. (1987a) against cyclin/PCNA. Detection of the bound antibody was performed by the indirect method with biotinylated sheep antibody and streptavidin-biotin-peroxidase complexes. No, or(More)
Tumor necrosis factor (TNF) is cytotoxic for many tumoral cell lines, whereas normal cells generally are considered resistant to this action. This study shows that this cytokine causes massive death of bovine endothelial cells in primary culture in a concentration- and time-dependent manner. Dying cells exhibit all the ultrastructural changes and the(More)
Two-third hepatectomy or sham operation was performed in BD IX rats immediately after intraportal injection of colon adenocarcinoma cells of the DHD-K12-TR strain. A dramatic increase in the incidence and growth of tumor cell colonies formed in the liver was observed in the partially hepatectomized as compared to sham-operated animals. Tumors formed in(More)
MCF-7 cells were co-transfected with the human HSP27 antisense cDNA and the neomycin resistance gene, included in the constitutive expression vector pSVL, and the phenotypical changes associated with decreased expression of the HSP27 protein were analysed. Three out of 10 neomycin-resistant clones obtained proliferated normally and showed a normal HSP27(More)