Histology and histopathology Vol.11, nº 4 (1996)
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- 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 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 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 aspects of the yol k-sac and digestive tract of larvae of the Senegal sole, Solea senegalensis (Kaup, 1858)(Murcia : F. Hernández, 1996) Sarasquete, C.; Gonzalez de Canales, M.L.; Arellano, J.M.; Muñoz-Cueto, J.A.; Ribeiro, L.; Dinis, M.T.Histochemical distribution of glycoproteins, carbohydrates and proteins rich in different aminoacids were studied using histological and histochemical procedures, in Senegal sole, Solea senegalensis (Kaup, 1858) larvae from hatching until day 15. Glycogen, proteins and glycoproteins were detected in the yolk-sac of the larvae at hatching and during the yolk-resorption. The epithelia1 digestive system (brush border, enterocytes and goblet cells) contained neutral and acid mucins (carboxylated andlor sulphated). Glycogen was observed in the cytoplasm of the digestive absortive cells (enterocytes) and in the liver (hepatocytes) on day 3-4 posthatching. Protein reactions, and specially those that showed proteins rich in arginine, tyrosine and tryptophan, were very intense in the zymogen granules of the pancreatic cells. Oesophageal and intestinal goblet cells contained glucose N-acetyl and sialic acid residues, but the mucin content of these mucous cells did not show affinity towards Con-A, suggesting the absence of glycoproteins with Mannose andlor glucose residues. WGA showed a very intense positivity in the microvilli of the digestive epithelium of the larvae and positive granules for both lectins, specially for Con-A, were detected in the cytoplasm of the anterior intestinal enterocytes.
- PublicationOpen AccessThe role of neuromedin B in the regulation of rat pituitary-adrenocortical function(Murcia : F. Hernández, 1996) Malendowicz, L.K.; Macchi, C.; Nussdorfer, G.G.; Nowak, M.The effects of a 7-day administration of neuromedin B (NMB) andlor ( ~ ~D-rphe~12,)-b ornbesin, an NMB-receptor antagonist (NMB-A) on the function of pituitary-adrenocortical axis were investigated in the rat. NMB raised the plasma concentration of aldosterone, without affecting that of ACTH or corticosterone; the simultaneous administration of NMB-A prevented the effect of NMB. Neither NMB nor NMB-A treatments induced significant changes in adenohypophysis and adrenal weights, nor in the average volume of zona glomerulosa and zona reticularis cells. NMB-A administration lowered the volume of zona fasciculata cells, an effect annulled by the concomitant NMB administration. Our results suggest that NMB specifically stimulates aldosterone secretion, and that endogenous NMB or NMB-like peptides exert a tonic stimulating action on the growth of zona fasciculata cells.