Home About us Contact
|
Home About us Contact | ||
|
|
||
Epithelial Structures (epithelial + structure)
Selected AbstractsIn vitro reconstructed mucosa-integrating Langerhans' cellsEXPERIMENTAL DERMATOLOGY, Issue 4 2003P. Sivard Abstract:, All three-dimensional in vitro mucosal models constructed, thus far, have only been reconstituted by epithelial cells. We have developed a reconstructed oral and vaginal epithelium that integrates Langerhans' cells (LC), the dendritic cells (DC) of malpighian epithelia. The epithelium was composed of gingival or vaginal keratinocytes seeded on a de-epidermized dermis (DED) and grown in submerged culture for 2 weeks. LC precursors, obtained after differentiation of cord blood-derived CD34+ hematopoietic progenitor cells (CD34+HPC) by granulocyte macrophage-colony stimulating factor (GM-CSF), tumor necrosis factor-, (TNF-,), transforming growth factor-, (TGF-,) and Flt3-ligand (Flt3-L), were introduced after 6,8 days of culture into the reconstituted epithelium. The in vitro reconstituted mucosal epithelium formed a multilayered, well-differentiated epithelial structure, confirmed by the immunohistochemical expression of cytokeratins 4, 6, 10, 13, 14, 16 and involucrin. LC were identified in the basal and suprabasal epithelial layers by CD1a antigen, S100 protein and Langerin/CD207 expression, and by transmission electron microscopy. Type IV collagen was expressed at the chorio,epithelial junction, and most ultrastructural features of this junction were visualized by electron microscopy. This in vitro reconstructed gingiva or vagina integrating LC represents interesting models very similar to native tissues. Because LC play an important role in the mucosal immune system, our models could be useful for conducting studies on interactions with pathogenic agents (viruses, bacteria etc.), as well as in pharmacological, toxicological and clinical research. [source] p63 expression in normal human epidermis and epidermal appendages and their tumorsJOURNAL OF CUTANEOUS PATHOLOGY, Issue 1 2003Miki Tsujita-Kyutoku Background:, p63, a member of the p53 gene family, is expressed in basal cells of several different organs. Methods:, The immunoreactivity of p63 was examined in normal human epidermis and epidermal appendages and their tumors, and compared with proliferative activity as evaluated by Ki-67. Results:, In normal skin, p63 expression was seen in basal/suprabasal cells of the epidermis, outer root sheath and hair matrix cells of the hair follicle, seboblast situated in the outermost layer of sebaceous glands, and outer layer cells of the ductal portion and myoepithelial cells of the secretory portion of the sweat glands. p63 expression was confined to the cells forming a continuous basal rim along the normal epithelial structure. In tumors, p63 expression resembled that in normal tissue in that tumor components originating from p63-positive cells were constantly positive for p63. In normal and tumor tissues, not all p63-positive cells were positive for Ki-67. Conclusions:, p63 expression may be a marker of basal/progenitor cells in tumors of epidermis and epidermal appendages, and may be a diagnostic marker of these tumors. [source] Cover Picture: BioEssays 1/2009BIOESSAYS, Issue 1 2009Article first published online: 22 JAN 200 Cover Photograph: A photograph of Oscarella lobularis in a typical biocoenosis. This common and easily accessible sponge is characterized by relatively simple histology and cell composition, absence of skeleton, and strongly pronounced epithelial structure. On pages tkk-tkk, Ereskovsky et al, detail the specific features that make O. lobularis a promising homoscleromorph sponge model for evolutionary and developmental researchers. [source] The Homoscleromorph sponge Oscarellalobularis, a promising sponge model in evolutionary and developmental biologyBIOESSAYS, Issue 1 2009Model sponge Oscarella lobularis Abstract Sponges branch basally in the metazoan phylogenetic tree and are believed to be composed of four distinct lineages with still uncertain relationships. Indeed, some molecular studies propose that Homoscleromorpha may be a fourth Sponge lineage, distinct from Demospongiae in which they were traditionally classified. They harbour many features that distinguish them from other sponges and are more evocative of those of the eumetazoans. They are notably the only sponges to possess a basement membrane with collagen IV and specialized cell-junctions, thus possessing true epithelia. Among Homoscleromorphs, we have chosen Oscarella lobularis as a model species. This common and easily accessible sponge is characterized by relatively simple histology and cell composition, absence of skeleton, and strongly pronounced epithelial structure. In this review, we explore the specific features that make O. lobularis a promising homoscleromorph sponge model for evolutionary and developmental researches. [source] Zonal differentiation of the epithelium including the lid wiper at the human lid marginACTA OPHTHALMOLOGICA, Issue 2008E KNOP Purpose The lid margin represent the "other end" of the tear film and appear critically important for ocular surface integrity, in addition to the glandular structures that produce the tears. It guarantees the thin expansion of the tear film with every blink and prevents the leakage of tears over the lid border. However, the differentiation of the lid margin zones is insufficiently known as yet. Methods The upper and lower lid margin in human whole-mount specimens from ten body donors was investigated in serial section histology and compared to the image by in-vivo confocal microscopy in four eyes with a Heidelberg retina tomograph and Rostock cornea module (RLSM). Results At the inner lid border, following the keratinised epidermis of the free lid margin, a narrow zone (100-150µm) of para-keratinised squamous epithelium represented the muco-cutaneous junction (MCJ) corresponding to the line of Marx. This was followed by a much broader zone of epithelial thickening (50-100µm) that formed a kind of cushion, reclined sharply at the inner lid border and represented the so called lid wiper which extended for about 1mm and finally transformed into the epithelium of the sub-tarsal fold. MCJ and lid wiper extended all along the lid margin from nasal to temporal in upper and lower lid. Details of the epithelial structure as well as the underlying dermal papillae in these zones were also detectable by RLSM. Conclusion Due to its location and structure, the lid wiper appears as the structure that actually spreads the tear film and is distinct from the MCJ/line of Marx. Better knowledge of the lid margin structure and its different zones appears important for the understanding of ocular surface disease, in particular the dry eye disease. [source] Zebrafish E-cadherin: Expression during early embryogenesis and regulation during brain developmentDEVELOPMENTAL DYNAMICS, Issue 2 2001Sherry G. Babb Abstract Zebrafish E-cadherin (cdh1) cell adhesion molecule cDNAs were cloned. We investigated spatial and temporal expression of cdh1 during early embryogenesis. Expression was observed in blastomeres, the anterior mesoderm during gastrulation, and developing epithelial structures. In the developing nervous system, cdh1 was detected at the pharyngula stage (24 hpf) in the midbrain-hindbrain boundary (MHB). Developmental regulation of MHB formation involves wnt1 and pax2.1. wnt1 expression preceded cdh1 expression during MHB formation, and cdh1 expression in the MHB was dependent on normal development of this structure. © 2001 Wiley-Liss, Inc. [source] Clinicopathological and immnuohistochemical findings in a series of folliculosebaceous cystic hamartomaJOURNAL OF CUTANEOUS PATHOLOGY, Issue 2 2009Jose M. Suarez-Peñaranda Background:, Folliculo-sebaceous cystic hamartoma (FSCH) is an uncommon skin condition presenting as a slow-growing papulo-nodular lesion, in or around the nose. Most cases are not clinically suspected and only histopathological examination allows the diagnosis. Pathological features include a dermal-located infundibulo-cystic structure with sebaceous glands radiating around, a stromal component encircling the epithelial structures, with clefts between the lesional epithelial and stromal parts, as well as between this and the adjacent dermis. Results:, We report eight patients with the diagnosis of FSCH (5 females and 3 males), with ages ranging from 35 to 77 years. Most cases (5 out of 8) were located in or around the nose and sizes were comprised between 0.6 and 1.2 cm. Lesions had grown for long periods of time, up to ten years in one case. Immunohistochemistry showed staining for p63 in the epithelial component of all lesions, while CD10 was only present in some sebocytes. CD34 and Factor XIIIa positive cells were present in the lesional stroma. Staining for androgen and alpha-estrogen receptors was also usually noticed. Conclusions:, FCSH is a hamartomatous skin lesion, clinically indistinct but with well-defined histopathological features. Immunohistochemistry shows a profile very close to normal sebaceous glands. [source] Androgen Receptor Expression Helps to Differentiate BCC From Trichoblastoma and TrichoepitheliomaJOURNAL OF CUTANEOUS PATHOLOGY, Issue 1 2005L. Izikson Histological differentiation between basal cell carcinoma and benign trichoblastic neoplasms such as trichoepithelioma and trichoblastoma can be difficult on small biopsies. Therefore, several attempts have been made to identify immunohistochemical differences between these entities. Recent studies showed androgen receptor expression in a number of mature epithelial structures in the skin and in epithelial neoplasms including basal cell carcinoma. In contrast, androgen receptor expression was absent in mature hair follicles or the few trichogenic neoplasms studied to date. These findings suggested that androgen receptor expression might be a useful adjunct in the histological differential diagnosis between basal cell carcinoma and benign trichoblastic neoplasms. Therefore, we performed immunohistochemical analysis of androgen receptor expression in 32 basal cell carcinomas and 10 benign trichoblastic tumors (6 trichoepitheliomas and 4 trichoblastomas). In our study, expression of androgen receptor was detected in 78% of basal cell carcinomas. None of the trichoblastic tumors showed any androgen receptor immunoreactivity. These results confirm the lack of androgen receptor expression in benign trichoblastic neoplasms and indicate that finding of androgen receptor expression points to basal cell carcinoma as the most likely diagnosis. [source] Subunits of the epithelial sodium channel family are differentially expressed in the retina of mice with ocular hypertensionJOURNAL OF NEUROCHEMISTRY, Issue 1 2005Frank M. Dyka Abstract Glaucoma is a prevalent cause of blindness, resulting in the apoptotic death of retinal ganglion cells and optic nerve degeneration. The disease is often associated with elevated intraocular pressure, however, molecular mechanisms involved in ganglion cell death are poorly understood. To identify proteins contributing to this pathological process, we analysed the retinal gene expression of DBA/2J mice that develop an elevated intraocular pressure by the age of 6 months with subsequent ganglion cell loss. In this study, we identified subunits of the epithelial sodium channel (ENaC) family that are specifically expressed under elevated intraocular pressure. Using reverse transcriptase polymerase chain reaction we observed a significant increase of ,-ENaC in the neuronal retina of DBA/2J mice when compared with control animals, while ,-ENaC and ,-ENaC were not detectable in this tissue. Specific immune sera to ENaC subunits showed up-regulation of ,-ENaC in synaptic and nuclear layers of the retina, and in the retinal pigment epithelium. Consistent with our polymerase chain reaction data, ,-ENaC was not detected by specific antibodies in the retina, while ,-ENaC was only present in the retinal pigment epithelium under ocular hypertension. Finally, the increase of ,-ENaC gene expression in the neuronal retina and the retinal pigment epithelium was not observed in other tissues of DBA/2J mice. Since the intraocular pressure is regulated by the transport of aqueous humour across epithelial structures of the eye that in turn is associated with ion flux, the specific up-regulation of ENaC proteins could serve as a protecting mechanism against elevated intraocular pressure. [source] Up-regulation of proproliferative genes and the ligand/receptor pair placental growth factor and vascular endothelial growth factor receptor 1 in hepatitis C cirrhosisLIVER INTERNATIONAL, Issue 7 2007Xiao X. Huang Abstract Background/Aims: Cirrhosis can lead to hepatocellular carcinoma (HCC). Non-diseased liver and hepatitis C virus (HCV)-associated cirrhosis with or without HCC were compared. Method: Proliferation pathway genes, immune response genes and oncogenes were analysed by a quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and immunostaining. Results: Real-time RT-PCR showed up-regulation of genes in HCV cirrhosis including the proliferation-associated genes bone morphogenetic protein 3 (BMP3), placental growth factor 3 (PGF3), vascular endothelial growth factor receptor 1 (VEGFR1) and soluble VEGFR1, the oncogene FYN, and the immune response-associated genes toll-like receptor 9 (TLR9) and natural killer cell transcript 4 (NK4). Expressions of TLR2 and the oncogenes B-cell CLL/lymphoma 9 (BCL9) and PIM2 were decreased in HCV cirrhosis. In addition, PIM2 and TLR2 were increased in HCV cirrhosis with HCC compared with HCV cirrhosis. The ligand/receptor pair PGF and VEGFR1 was intensely expressed by the portal tract vascular endothelium. VEGFR1 was expressed in reactive biliary epithelial structures in fibrotic septum and in some stellate cells and macrophages. Conclusion: PGF and VEGFR1 may have an important role in the pathogenesis of the neovascular response in cirrhosis. [source] Vincristine-induced Eccrine Squamous SyringometaplasiaPEDIATRIC DERMATOLOGY, Issue 6 2008Lacey Mitchell Thomas M.D. Concentration of the chemotherapeutic agents is believed to effect toxic changes in these epithelial structures. We report the first case of vincristine-induced eccrine squamous syringometaplasia in a 12-year-old patient undergoing treatment for rhabdomyosarcoma. [source] Laser-capture microdissection in prostate cancer research: establishment and validation of a powerful tool for the assessment of tumour,stroma interactionsBJU INTERNATIONAL, Issue 6 2008Chitranjan J. Shukla OBJECTIVES To describe our experience with the optimization and validation of laser-capture microdissection (LCM) for biomarker analysis in prostate tissues. As LCM allows the separation of benign and malignant epithelial structures and stromal elements, it not only allows identification of the source of the biomarker, but might also accentuate gene or protein expression changes by reducing contamination by other cellular elements. MATERIALS AND METHODS In all, 19 fresh-frozen prostate tissue samples were subjected to LCM, with the cDNA being analysed using quantitative polymerase chain reaction for several genes, to identify the optimum number of cells for capture, as well as gene markers assessing for the purity of the captured cells. The localization was further confirmed by in situ hybridization. RESULTS Prostate-specific antigen (PSA) and cytokeratin 8, were expressed solely by epithelial cells, whereas hepatocyte growth factor (HGF) and tissue inhibitor of metalloproteinases-3 (TIMP3) were expressed only by stromal cells, and the levels of transcripts of these genes were unaltered between benign and malignant tissues. CONCLUSIONS These data suggest that PSA, cytokeratin 8, HGF and TIMP3 are reliable gene markers of purity of epithelial and stromal compartments for LCM of prostate tumours. Although this technique is not new and is increasingly used in laboratories, it needs optimization and stringent validation criteria before data analysis. This applies to all tissue types subjected to LCM. [source] | |||||||||||||