Search results for "epithelium"

Manganese effects on haematopoietic cells and circulating coelomocytes of Asterias rubens (Linnaeus)

2008

Abstract Manganese (Mn) is a naturally abundant metal in marine sediments where it mainly occurs as MnO 2 . During hypoxic conditions it is converted into a bioavailable state, Mn 2+ , and can reach levels that previously have shown effects on immune competent cells of the crustacean, Nephrops norvegicus . Here we investigated if Mn also affects circulating coelomocytes and their renewal in the common sea star, Asterias rubens , when exposed to concentrations of Mn that can be found in nature. When the sea stars were exposed to Mn it accumulated in the coelomic fluid and the number of circulating coelomocytes, in contrast to what was recorded in Nephrops , increased significantly. By using …

Unusual basement layer in the midgut of gammaridean Niphargus virei Chevreux (Crustacea, Amphipoda).

1988

The basement membrane of the midgut and posterior caeca epithelium in the gammaridean amphipod Niphargus virei Chevreux, 1896 is made of an unusual structure. This basal lamina, properly called “basal layer”, shows a dense sheet formed by a system of dense hexagonal plates connected by thin filaments. Histochemical studies and enzymatic reactions lead to the conclusion that these structures are proteinaceous, without collagenous protein, and embedded in a neutral polysaccharide matrix. The possible mechanical significance of these mesenteric structures is discussed.

2021

The intestinal microbiota influences mammalian host physiology in health and disease locally in the gut but also in organs devoid of direct contact with bacteria such as the liver and brain. Extracellular vesicles (EVs) or outer membrane vesicles (OMVs) released by microbes are increasingly recognized for their potential role as biological shuttle systems for inter‐kingdom communication. However, physiologically relevant evidence for the transfer of functional biomolecules from the intestinal microbiota to individual host cells by OMVs in vivo is scarce. By introducing Escherichia coli engineered to express Cre‐recombinase (E. coli Cre) into mice with a Rosa26.tdTomato‐reporter background, …

Supravital Uptake of Methylene Blue by Dendritic Cells within Stratified Squamous Epithelia: a Light and Electron Microscope Study

1996

Electron microscopic data on methylene blue staining of dendritic cells in the epithelia of the soft palate and skin of the mouse after supravital dye injection are presented. The ultra-structural details were compared with corresponding light microscopic findings. Methylene blue stained tissue was fixed by immersion in a paraformaldehyde-glutaraldehyde solution containing phosphomolybdic acid. The ensuing dye precipitate was stabilized by ammonium heptamolybdate. The light microscopic investigation revealed that selective staining of dendritic cells depended on the presence of ambient oxygen. In addition, delicate morphological characteristics, like spinous structures of the dendrites, wer…

Engagement of the periesophageal ring during Holothuria polii response to erythrocyte injection.

2009

In Holothuria polii, the periesophageal ring is an important organ supplying spherule cells after stimulation with foreign material. In animals injected with formalinized sheep erythrocytes, in fact, a depletion of spherule cells is observed in the periesophageal ring, whereas in the connective tissue, in the external epithelium and around the antigen- injected site, small, transparent cells can be visualized. It is supposed that the latter are stem cells of spherule cells.

Immunohistochemical expression of apoptotic factors, cytokeratins, and metalloproteinase-9 in periapical and epithelialized gingival lesions

2012

Bellmann K, 2010, CELL STRESS CHAPERON, V15, P101, DOI 10.1007-s12192-009-0126-9; Cappello Francesco, 2011, Front Biosci (Schol Ed), V3, P341, DOI 10.2741-s155; Cappello F, 2006, CANCER, V107, P2417, DOI 10.1002-cncr.22265; Cappello F, 2002, EUR J HISTOCHEM, V46, P199; Carneiro E, 2009, ORAL SURG ORAL MED O, V107, P127, DOI 10.1016-j.tripleo.2008.07.030; Chandra D, 2007, J BIOL CHEM, V282, P31289, DOI 10.1074-jbc.M702777200; Fujita Y, 2011, ODONTOLOGY, V100, P215; Garcia Celia Carrillo, 2007, Med Oral Patol Oral Cir Bucal, V12, pE585; Garcia CC, 2009, ORAL SURG ORAL MED O, V107, pE43, DOI 10.1016-j.tripleo.2008.12.002; Gregory CD, 2011, J PATHOL, V223, P177, DOI 10.1002-path.2792; Gupta S, …

B Cell Expansion Hinders the Stroma-Epithelium Regenerative Crosstalk During Mucosal Healing

2021

Little is known about the pro-resolution role of immune cells recruited to damaged tissue. Using an experimental model of intestinal epithelial damage and repair, we identified B cells as the dominant cell type in the healing colon. Single-cell RNA-sequencing (scRNAseq) revealed the expansion of an IFN-induced B cell subset during experimental mucosal healing which was associated with colitis severity. In line with this, B cell depletion during mucosal healing resulted in accelerated recovery upon injury, which was associated with enhanced expression of tissue remodeling genes. scRNA-seq from the epithelial and stromal compartment confirmed that lack of B cells during mucosal healing alters…

2014

Type I interferon (IFN-α/β) represents the key element of the antiviral defense mechanisms against most viruses, however, rotaviruses that infect the gut epithelium, display little sensitivity to type I IFN. Here, we report that the intestinal epithelium is a unique cell compartment in the organism that does not depend on type I IFN in antiviral defenses. Type I IFN was unable to induce antiviral gene expression in intestinal epithelial cells (IEC) that correlated well with low epithelial expression of both chains of the IFN-α/β receptor complex. In stark contrast, IECs strongly responded to IFN-λ on baseline, upon IFN treatment and virus challenge. Commensal microflora was found to establi…

Indocyanine Green Angiography in Congenital Hypertrophy of the Retinal Pigment Epithelium

2017

PURPOSE To report a case of congenital hypertrophy of the retinal pigment epithelium followed up for 7 years showing features not previously reported. METHODS A complete fundus examination including fluorescein angiography was performed at first examination and at follow-up. RESULTS The area of congenital hypertrophy of the retinal pigment epithelium presented morphologic changes, showing enlargement of the lesion on one side associated with partial regression on another side. In addition, the indocyanine green angiography findings revealed that this test was more useful than fluorescein angiography to delineate the real boundaries of the lesion and disclosed hypofluorescent areas inside th…

Indocyanine green in congenital hypertrophy of the retinal pigment epithelium

2005

To report a case of congenital hypertrophy of the retinal pigment epithelium followed up for 7 years showing features not previously reported. A complete fundus examination including fluorescein angiography was performed at first examination and at follow-up. The area of congenital hypertrophy of the retinal pigment epithelium presented morphologic changes, showing enlargement of the lesion on one side associated with partial regression on another side. In addition, the indocyanine green angiography findings revealed that this test was more useful than fluorescein angiography to delineate the real boundaries of the lesion and disclosed hypofluorescent areas inside the main lesion that were …