Histology and histopathology Vol.21, nº 1 (2006)

Ir a Estadísticas

Permanent URI for this collection

http://hdl.handle.net/10201/177581

Browse

Recent Submissions

Now showing 1 - 5 of 11
  • Thumbnail Image
    Publication
    Open Access
    Histochemical analysis of glycoconjugates in the domestic cat testis
    (Murcia : F. Hernández, 2006) Desantis, S.; Ventriglia, G.; Zubani, D.; Deflorio, M.; Megalofonou, P.; Acone, F.; Zarrilli, A.; Palmieri, G.; De Metrio, G.
    The localization and characterization of oligosaccharide sequences in the cat testis was investigated using 12 lectins in combination with the ßelimination reaction, N-Glycosidase F and sialidase digestion. Leydig cells expressed O-linked glycans with terminal aGalNAc (HPA reactivity) and N-glycans with terminal/internal aMan (Con A affinity). The basement membrane showed terminal Neu5Aca2,6Gal/GalNAc, Galß1,3GalNAc, a/ßGalNAc, and GlcNAc (SNA, PNA, HPA, SBA, GSA II reactivity) in O-linked oligosaccharides, terminal Galß1,4GlcNAc (RCA120 staining) and aMan in N-linked oligosaccharides; in addition, terminal Neu5Aca2,3Galß1,4GlcNac, Forssman pentasaccharide, aGal, aL-Fuc and internal GlcNAc (MAL II, DBA, GSA I-B4, UEA I, KOH-sialidase-WGA affinity) formed both O- and N-linked oligosaccharides. The Sertoli cells cytoplasm contained terminal Neu5Ac- Galß1,4GlcNAc, Neu5Ac-ßGalNAc as well as internal GlcNAc in O-linked glycans, aMan in N-linked glycoproteins and terminal Neu5Aca2,6Gal/ GalNAc in both O- and N-linked oligosaccharides. Spermatogonia exhibited cytoplasmic N-linked glycoproteins with aMan residues. The spermatocytes cytoplasm expressed terminal Neu5Aca2,3Galß1,4 GlcNAc and Galß1,3GalNAc in O-linked oligosaccharides, terminal Galß1,4GlcNAc and a/ßGalNAc in N-linked glycoconjugates. The Golgi region showed terminal Neu5aca2,3Galß1,4GlcNac, Galß1,4GlcNAc, Forssman pentasaccharide, and aGalNAc in O-linked oligosaccharides, aMan and terminal ßGal in N-linked oligosaccharides. The acrosomes of Golgi-phase spermatids expressed terminal Galß1,3GalNAc, Galß1,4GlcNAc, Forssmann pentasaccharide, a/ßGalNAc, aGal and internal GlcNAc in O-linked oligosaccharides, terminal a/ßGalNAc, aGal and terminal/internal aMan in N-linked glycoproteins. The acrosomes of cap-phase spermatids lacked internal Forssman pentasaccharide and aGal, while having increased a/ßGalNAc. The acrosomes of elongated spermatids did not show terminal Galß1,3GalNAc, displayed terminal Galß1,4GlcNAc and a/ßGalNAc in N-glycans and Neu5Ac-Galß1,3GalNAc in O-linked oligosaccharides.
  • Thumbnail Image
    Publication
    Open Access
    Current concepts in ovarian epithelial tumorigenesis: correlation between morphological and molecular data
    (Murcia : F. Hernández, 2006) Scott, Mike; McCluggage, W.G
    Ovarian carcinoma is the most lethal gynaecological malignancy, most tumours being advanced at presentation. However, little is known about precursor lesions and the cell of origin of epithelial ovarian malignancy. In this review, the proposed cell of origin is discussed as well as recent molecular data relating to ovarian cancers of different morphological types. It is stressed that ovarian carcinoma is a heterogeneous group of neoplasms with several different morphological types, each with their own underlying molecular genetic events. Recent data suggest that mucinous ovarian cancers and a small subset of serous cancers (low grade ovarian serous carcinoma) develop through a well-defined adenoma-carcinoma sequence while the much more common high grade ovarian serous carcinoma develops de novo from the ovarian surface epithelium or the epithelium of cortical inclusion cysts. The realisation that various morphological types of epithelial ovarian cancer are associated with different molecular genetic events is a major advance in the study of ovarian cancer. It can be anticipated that this will lead to the development of specific therapeutic agents of value against a specific tumour type.
  • Thumbnail Image
    Publication
    Open Access
    Winding through the WNT pathway during cellular development and demise
    (Murcia : F. Hernández, 2006) Li, F.; Chong, Z.Z.; Maiese, K.
    In slightly over a period of twenty years, our comprehension of the cellular and molecular mechanisms that govern the Wnt signaling pathway continue to unfold. The Wnt proteins were initially implicated in viral carcinogenesis experiments associated with mammary tumors, but since this period investigations focusing on the Wnt pathways and their transmembrane receptors termed Frizzled have been advanced to demonstrate the critical nature of Wnt for the development of a variety of cell populations as well as the potential of the Wnt pathway to avert apoptotic injury. In particular, Wnt signaling plays a significant role in both the cardiovascular and nervous systems during embryonic cell patterning, proliferation, differentiation, and orientation. Furthermore, modulation of Wnt signaling under specific cellular influences can either promote or prevent the early and late stages of apoptotic cellular injury in neurons, endothelial cells, vascular smooth muscle cells, and cardiomyocytes. A number of downstream signal transduction pathways can mediate the biological response of the Wnt proteins that include Dishevelled, ß-catenin, intracellular calcium, protein kinase C, Akt, and glycogen synthase kinase-3ß. Interestingly, these cellular cascades of the Wnt-Frizzled pathways can participate in several neurodegenerative, vascular, and cardiac disorders and may be closely integrated with the function of trophic factors. Identification of the critical elements that modulate the Wnt-Frizzled signaling pathway should continue to unlock the potential of Wnt pathway for the development of new therapeutic options against neurodegenerative and vascular diseases.
  • Thumbnail Image
    Publication
    Open Access
    Ghrelin cell density in the gastrointestinal tracts of animal models of human diabetes
    (Murcia : F. Hernández, 2006) Rauma, J.; Spangeus, A.; El-Salhy, M.
    Ghrelin cell density in the gastrointestinal tract of animal models of human diabetes type 1 and 2 was investigated. The animals used were non-obese diabetic (NOD) mice and obese diabetic mice. Ghrelin cells were detected by immunohistochemistry and quantified by computerized image analysis. Ghrelinimmunoreactive cells were detected in all animals studied. They were abundant in the oxyntic mucosa, patchy and few in the duodenum and rare in the colon. The density of ghrelin-immunoreactive cells decreased in diabetic, pre-diabetic NOD mice and in obese diabetic mice as compared to controls, though not statistically significant. It was concluded that the reduced density of ghrelin-immunoreactive cells in animal models of human diabetes type 1 and 2 might explain the slow gastric emptying and slow intestinal transit found in diabetes gastroenteropathy.
  • Thumbnail Image
    Publication
    Open Access
    Recombinant generation of two fragments of the rat complement inhibitory factor H [FH(SCR1-7) and FH(SCR1-4)] and their structural and functional characterization in comparison to FH isolated from rat serum
    (Murcia : F. Hernández, 2006) Demberg, T.; Heine, I.; Götze, O.; Altermann, W.W.; Seliger, B.; Schlaf, G.
    Factor H (FH) is the predominant soluble inhibitor of the complement system. With a concentration of 200-800 µg/ml in human and rat plasma it acts as a cofactor for the soluble factor I (FI)-mediated cleavage of the component C3b to iC3b. Furthermore it competes with factor B for binding to C3b and C3(H2O) and promotes the dissociation of the C3bBb complex. FH is a monomer of about 155 kDa which comprises 20 short consensus repeats (SCR), each of which is composed of approximately 60 amino acid (aa) residues. Two functional fragments of FH comprising the SCR1-4 or SCR1-7 were generated using either the Baculovirus system or stably transfected human embryonal kidney cells, respectively. These fragments, as well as FH purified from rat serum, were first analyzed for their relative molecular weights (Mr) using non-reducing or reducing SDS-PAGE. The Mr of the FH variants differed by about 20 % depending on the experimental conditions employed. Only the Mr of proteins separated under reducing conditions were in accordance with the MW calculated from the aa sequence. Analyses of the glycosylation patterns using PAS-staining showed a lack of staining of the recombinant variants (SCR1-4 and SCR1-7) in contrast to FH(SCR1-20) from serum. Using a complement hemolysis assay (CH50-assay) all three variants exhibited a molar complement inhibitory activity of FH(1-20)/FH(1-7)/FH(1-4) of about 3/1/1. These data support the postulated model of FH bearing three binding sites for its ligand C3b, from which one is located in the SCR1-4, whereas the other two are located in the SCR8-20.