Histology and histopathology Vol.11, nº 4 (1996)
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- PublicationOpen AccessCyclosporin-A affects the organization of cytoskeleton of normal human keratinocytes in culture(Murcia : F. Hernández, 1996) Prignano, F.; Domenici Lombardo, L.; Gerlini, G.; Pimpinelli, N.; Romagnoli, P.Cyclosporin-A (CsA) is a potent immunoregulatory molecule which has been widely used in many immunomediated and inflammatory skin diseases. It inhibits the proliferation of keratinocytes, but its possible effects(s) on cell differentiation are poorly known. To address this issue, we have studied the influence of CsA on the assembly of intermediate filaments by normal human keratinocytes in culture. Control keratinocytes were flat; the cells which had not reached confluence stained intensely for vimentin and weakly for cytokeratins; confluent cells stained with intermediate intensity for both types of proteins and the cells adhering on the top of others, interpreted as the best differentiated ones, stained for cytokeratins but not for vimentin. CsA (1.6 pg/ml for 10 days) inhibited the growth of keratinocytes, which never reached confluence; most cells appeared small and roundish, only some stained for cytokeratins and few for vimentin. By electron microscopy, a well organized meshwork of tonofibrils was recognized in many control keratinocytes, but never in CsA-treated keratinocytes. We propose that the cytoskeleton could be a target of CsA and that its alteration mediates other effects of CsA on keratinocytes, including those on cell growth.
- PublicationOpen AccessLectin histochemistry of the submandibular and sublingual salivary glands in rats(Murcia : F. Hernández, 1996) Hirshberg, A.; Bodner, L.; Naor, H.; Skutelsky, E.; Dayan, D.Tissue sections from rat submandibular and sublingual glands were studied with lectin probes to identify terminal sugars of the glycoconjugates in various cell types of the salivary glands. The lectins used in the study were Canavalia ensiformis (Con A), Triticum vulgaris (WGA), Succinyl WGA (S-WGA) Ricirzus communis I (RCA-I), Arachis hypogaea (PNA), and Ulex europeaus (UEA-I). The cytoplasm and cell membrane of both the serous and mucous acinar cells present high similarity in the distribution of some sugar residues, but differ considerably in the expression of specific sugars which appear either in the serous or in the mucous cells. The cytoplasm and cell membrane of the serous and mucous acinar cells express Mannose (Man) and Glucose (Glc), but lack Galactose (Gal), and N-acetylgalactosamine (GalNAc). Fucose (Fuc) is present only in the mucous acinar cytoplasm. The moderate to intense binding of WGA to the acinar and ductal cells and the lack of binding of S-WGA, indicate the presence of sialic acid rather than N-acetylglucosamine (GlcNAc). These sialic acid residues are not associated with PNA-binding sugar sequences as pretreatment with neuraminidase is not associated with exposure of additional PNA receptors.
- PublicationOpen AccessThe retinoblastoma gene family and its role in proliferation, differentiation and development(Murcia : F. Hernández, 1996) De Luca, A.; Esposito, V.; Baldi, A.; Giordano, A.The retinoblastoma gene family is composed of three members: the retinoblastoma gene, one of the most well studied tumor suppressor genes and two related proteins, p107 and pRb2lp130. These three proteins share many structural and functional features and play a fundamental role in growth control. Intense investieation of these moteins has identified a series of U similar cell-cycle regulators and transcription factors with which they interact. Although the precise function of the retinoblastoma gene product and its relatives remains unknown, recent data suggests that they play parallel roles in controlling cell cycle progression and promoting cellular differentiation. In this review, we will attempt to clarify some of the molecular mechanisms by which these three related proteins cooperate to control cellular proliferation and differentiation.
- PublicationOpen AccessHistochemical detection of expression of binding sites for labelled hyaluronic acid and carrier-immobilized synthetic (histo-blood group trisaccharides) or biochemically purified (ganglioside GM1) glycoligands in nasal polyps and other human lesions including neoplasms(Murcia : F. Hernández, 1996) Hassid, S.; Salmon, I.; Bovin, N.V.; Kiss, R.; Gabius, H.J.; Danguy, A.This study is intended to demonstrate the versatility and feasibility of custom-made oligosaccharide- exposing neoglycoconjugates including histo-blood group epitopes in various human lesions, including nasal polyps. The binding of the biotinylated probes was determined on formalin-fixed paraffinembedded sections from archive materials. The general aspects of our results may be interpreted as follows: the neoglycoconjugates used here can readily detect differences in the ability of cells to bind glycan residues in tissue sections, thereby enabling the extent of the binding capacity of various types of human lesions to be compared. Furthermore, the reactivity to glycan may reflect characteristics of the cells and their environment. The investigation into pathological disorders with respect to the binding capacity of these carrierimmobilized mono- or oligosaccharide structures derived from custom-made synthesis or biochemical purification is based on the prospect of translating progress in this field into the establishment of potentially beneficial procedures for medical diagnosis and pathological classification.
- PublicationOpen AccessImmunocytochemical localization of myotonin protein kinase on muscle from patients with congenital myotonic dystrophy(Murcia : F. Hernández, 1996) Tachi, N.; Kozuka, N.; Ohya, K.; Chiba, S.; Kikuchi, K.Using a polyclonal anti myotonin-protein kinase (M-PK) antibody against synthetic M-PK peptides corresponding to part of the amino acid sequence, and the immunohistochemical analysis of indirect immunoperoxidase, we have investigated localization of M-PK on muscle from patients with congenital myotonic dystrophy. In congenital myotonic dystrophy (MD) patients, one month and 3 months old, M-PK was weakly expressed at sarcolemma of muscle fibers. In congenital MD patients from 2 to 9 years of age, M-PK was clearly expressed at sarcolemma of muscle fibers. M-PK of immature muscle is weakly expressed at sarcolemma. With aging, M-PK is clearly expressed at sarcolemma of muscle from MD patient and normal control.