Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P02794 (ferritin)
 17,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Organized lymphoid tissue in the rat colon exists as clusters (colonic lymphoid patches) of intramucosal and submucosal follicles in the proximal, mid, and distal colon, interspersed by solitary follicles. The follicular lymphoid cells of colonic lymphoid patches are separated from the gut lumen by a highly specialized lymphoepithelium which lacks mature goblet cells. Cells of this epithelium are of two types: those characterized by an electron-dense cytoplasm, large numbers of apical vesicles and lysosomes, and prolonged extensions of the apical cytoplasm forming thin partitions between the gut lumen and underlying intercellular spaces; and cells with a less electron-dense cytoplasm, distorted mitochondria, and little endoplasmic reticulum. Both cell types bear normal microvilli and have numerous lateral membrane processes which penetrate large intercellular spaces. A ferritin-India ink label infused into the colonic lumen was preferentially adsorbed onto the surface of this follicle-associated epithelium. Indigenous colonic bacteria were observed penetrating the superficial cytoplasm of the electron-dense cells where they were enclosed in lysosomes and digested. An antigen-sampling role is proposed for the colonic lymphoid patch epithelium.
 ...
PMID:Morphological study of antigen-sampling structures in the rat large intestine. 669 72

The derivation of membranous epithelial (M) cells, which are specialized antigen sampling cells overlying the lymphoid follicles of Peyer's patches, is unknown; it has been suggested recently, however, that M cells differentiate from absorptive cells on the follicular epithelium. To examine whether M cells, like other intestinal epithelial cells, derive directly from undifferentiated crypt cells, we studied the structure, selected functional features, proliferation, and distribution of Peyer's patch M cells in the ileum of adult mice. We observed a spectrum of M-cell structure ranging from mature to immature-appearing M cells. Most immature-appearing M cells lacked the central cytoplasmic hollow found in those mature M cells that contained lymphoid cells. The microvilli of immature-appearing M cells were more numerous and regular appearing than those of mature M cells, but they were sparser and shorter, and some were wider than those of absorptive cells. Many immature-appearing M cells contained more free ribosomes than did mature M cells. Both mature and immature-appearing M cells were observed on all regions of follicular domes, including the base near the mouths of surrounding crypts. Type 1 reovirions adhered with considerable selectivity to the apical membrane of mature and immature-appearing M cells but were observed in endocytic vesicles only in mature M cells. Neither mature nor immature-appearing M cells showed evidence of lipid absorption, in contrast to adjacent absorptive cells. Both mature and immature-appearing M cells internalized more bound cationized ferritin than did absorptive cells. Only mature M cells transported cationized ferritin to the intercellular spaces. Nuclei of a few immature-appearing M cells were labeled 24 h after injection of [3H]thymidine in concert with the appearance of labeled absorptive cell nuclei. These observations strongly suggest that many, if not all, M cells derive directly from undifferentiated crypt cells.
 ...
PMID:Structure, distribution, and origin of M cells in Peyer's patches of mouse ileum. 670 62

Ultrastructural localization of immunoglobulin G (IgG) in the postcapillary venules (PVC) of normal and nude mouse lymph nodes was examined in thin sections which had been stained sequentially with primary exposure to biotin-conjugated goat anti-mouse IgG serum and a secondary immersion in a ferritin-linked avidin (IF). In the normal mouse PCV, reaction products showing IgG-binding sites were detected as large IF clusters on the luminal membrane of the endothelial cells, as small IF clusters in the intercellular spaces between the endothelial cells and some migrating lymphocytes, and as uniform precipitates of large numbers of IF particles in the basement membrane. By contrast, nude mouse PCV retained a few or almost no IgG-binding sites in portions comparable to those observed in the normal mouse. A relatively large number of plasma cells in the lymphoid stroma of both strains possessed large IF clusters on the cell surfaces. The significance of the IgG localization in the PCV of the two strains is discussed in relation to the mechanism of lymphocyte recirculation.
 ...
PMID:An immunoelectron microscopic study of immunoglobulin G in the postcapillary venules of normal and nude mouse lymph nodes. 685 67

We describe a new cellular component of normal mouse thymuses, which is isolated by fractionated trypsin dissociation of minced thymus tissue followed by repeated unit gravity sedimentation. These cells are of unusually large size, with diameters of 30 mum and more. They represent cellular complexes of single large cells filled with high numbers of lymphoid cells. The majority of the engulfed lymphoid cells is not only fully intact, as judged by morphological criteria, but, moreover, includes a high proportion of mitotic figures. Electron microscopic investigations reveal the epithelial character of the large thymic nurse cells (TNC). The peripherally situated cytoplasmic tonofilament streams, and characteristic vacuoles filled with coarse, unidentified material, closely resemble cytoplasmic organelles found in the cortical reticuloepithelial cells described in situ. The internalized lymphocytes are located within caveolae lined by plasma membranes. These TNC caveolae are completely sequestered, and have lost any communication with the extracellular space, as demonstrated by the inability of an electrondense marker, cationized ferritin, to diffuse into the perilymphocytic clefts. The structural interactions between the membranes of the engulfed thymocytes with the surrounding TNC caveolar membranes were investigated both in ultrathin sections and in freeze-etch preparates. Two distinct contact types between both membranes were discerned: (a) complete, close contact along the entire lymphocyte circumference, and (b) more frequently, contact restricted to discrete, localized areas. Judging from their size and distribution, the localized contacts could correspond particle aggregates of freeze-etch preparates, which morphologically resemble certain stages of gap junction. Furthermore, we regularly found square arrays of particles of uniform size, which so far have been thought to be typical for cell membranes actively engaged in ion exchange. Tight junction-like particle arrays, which were present on TNC outer membranes, and probably represented disrupted contacts between adjacent TNC in the intact tissue, could not be found on caveolar or lymphocyte membranes. Finally, one of the most conspicuous specializations of the TNC caveolar membrane were membrane invaginations, which were arranged mainly in groups, and which probably reflect endo- or exocytotoxic events. We investigated the surface antigen phenotype of TNC by indirect immunofluorescence, with monoclonal antibodies against determinants of H-2- complex subregions as well as against lymphocyte differentiation markers. Semiquantification was reached with flow cytofluorimetry, followed by morphological control by fluorescence microscopy. The surface antigen formula of TNC is: Ig(-), Thy-l(-), H-2K(++), I-A (++), I-E/C(+), H-D(++), Ly-1(-), Ly-2(-), Qat-4(-), Qat-5(-), and peanut agglutinin (PNA)(-). Thymic macrophages, which were identified by double fluorescence, with rhodamine- coupled zymosan as a phagocytosis marker, were serologically identical with TNC. Free thymocytes, in contrast, had the following antigen formula: Ig(-), Thy-1(++), H-2K(+/-), I-A(-), I-E/C(-), H-2D(+/-), Ly-1(+/-), Ly-2(+), Qat- 4(-), Qat-5(-), and PNA(+). The unprecedented finding of high numbers of dividing thymocytes sojourning within thymic epithelial cells, and the particular specializations of the TNC caveolar membranes surrounding these engulfed thymocytes is the basis of a hypothesis that postulates that an intraepithelial differentiation cycle is one essential step in, intrathymic T lymphocyte generation.
 ...
PMID:Thymic nurse cells. Lymphoepithelial cell complexes in murine thymuses: morphological and serological characterization. 696 12

Mononuclear cells from peripheral blood of normal humans, unselected spleen cells from patients with Hodgkin's disease, and selected T and non-T lymphoid cells from normal peripheral blood and from the spleens of Hodgkin's disease patients were examined for de novo synthesis and secretion of ferritin. After precipitation of labeled lysates and supernatants from unseparated and selected T cells with antiserum to human liver ferritin, two bands were visible on sodium dodecyl sulfate-polyacrylimide gel analysis. The two bands were detected in molecular weight regions 19,000 and 21,000, which are thought to represent the L and H subunits of the ferritin molecule, respectively. The slower band (subunit H) was more radioactive than the faster band (subunit L). The H subunit is found in greater amounts in the serum of some tumor patients, but its cellular origin has not been established. The present findings indicate that cells of the immune system contribute to the synthesis and secretion of a ferritin molecule with a high proportion of H subunits.
 ...
PMID:Ferritin synthesis by human T lymphocytes. 696 22

Selected populations of human peripheral blood T lymphocytes, B lymphocytes, monocytes and polymorphonuclear cells were examined for their intracellular content of lactoferrin transferrin and ferritin by an indirect immunofluorescence technique. Lactoferrin was found in polymorphs but not in lymphoid cells. Two different lactoferrin staining patterns were observed which we designated 'perinuclear', characterized by a ring of positive material round the nucleus, and cytoplasmic, in which most positive material was distributed in the cytoplasm. The former staining pattern was found in high density polymorphs the latter was associated with low density polymorphs occasionally found contaminating the peripheral blood mononuclear cell suspension. After incubation in vitro, the perinuclear pattern changed to cytoplasmic staining. Transferrin was found in T cells and polymorphs. In contrast, only a few transferrin containing cells were detected in the B cell and monocyte fractions. Following overnight incubation, a halo of positive material was found surrounding T cells stained for transferrin, suggesting that T cells released transferrin during incubation. Ferritin was also found in T cells and adherent cells. Following latex particle ingestion, the intensity of ferritin staining was markedly increased. Only a small proportion of lymphoid cells and monocytes stained for transferrin or ferritin in the total peripheral blood mononuclear cell suspension. The results indicate, therefore, that in response to manipulation procedures used routinely for the selection of human peripheral blood lymphoid cells, detectable amounts of transferrin and ferritin are present in T but not B cells. The fact that T cells are equipped with proteins known to participate in binding and storage of iron may constitute, at least in part, the basis for the contribution of these cells to the regulation of other major biological systems.
 ...
PMID:Iron binding proteins in selected human peripheral blood cell sets: immunofluorescence. 700 Jan 58

1. The serum ferritin level provides a valuable index of the body iron store. An increase in serum ferritin has often been observed in patients with neoplastic disease and correlates well with the stage of cancer. A few studies have suggested the potential of urinary ferritin as a marker for transitional cell carcinoma. The rationale of the measurement, however, has not been investigated in detail. 2. Urinary ferritin levels were evaluated in patients with diverse urological diseases to investigate their potential clinical implications. 3. Analysis of logarithmic transformed values (ng/mg creatinine) showed that patients with both neoplastic and non-neoplastic urological diseases had significantly higher ferritin levels than normal control subjects (P = 0.02). There was no apparent difference between subgroups of patients with urological disease (P > 0.5). For patients with urothelial carcinoma, univariate analysis revealed a strong positive relationship between urinary ferritin levels and the density of lymphoid cells in tumour stroma (P = 0.0001), while no important association was observed with tumour grade (P = 0.32), stage (P = 0.29) or urinary cytology detection (P = 0.33). Patients with muscle-invasive tumour had significantly higher ferritin levels than those with papillary, superficial cancer (P < 0.05). For patients with non-neoplastic urological disease (n = 19), urinary ferritin levels tend to correlate with the severity of tissue inflammation (P = 0.03). 4. The results suggest that urinary ferritin may reflect the degree of local inflammatory reaction in the urinary tract.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Clinical significance of urinary ferritin excretion in patients with transitional cell carcinoma. 763 55

Uptake of ferritin by M cells in follicle-associated epithelium at various sites in the small and large intestines was examined in 4 healthy 5-week-old pigs by use of electron microscopy. A 2.5% solution of ferritin in saline was injected into ligated loops of the jejunum and ileum containing aggregations of lymphoid follicles (Peyer's patches), as well as into intestinal loops containing lymphoglandular complexes at the ileocecal junction, in the central colonic flexure, and in the rectum. As negative control, saline solution was injected into loops at identical localizations. After an exposure period of 2 hours, uptake of ferritin by M cells, but not by enteroabsorptive cells of the small and large intestines, was observed. Numbers of M cells with ferritin and total M cells were counted and the percentage was calculated. Total number of M cells was highest in lymphoglandular complexes in the rectum and lowest on domes of the ileal Peyer's patch. High numbers of M cells with ferritin were found on domes of the jejunal Peyer's patch, and in lymphoglandular complexes at the ileocecal entrance and in the rectum. Only a few M cells on domes of the ileal Peyer's patch and in lymphoglandular complexes in the central colonic flexure contained ferritin. The percentage of M cells with internalized ferritin was similar on domes of the ileal Peyer's patch, and in lymphoglandular complexes at the ileocecal junction and in the rectum. It was higher on domes of the jejunal Peyer's patches and lower in lymphoglandular complexes of the central colonic flexure. Ferritin was found in the apical tubulovesicular system, multivesicular bodies, and a few vacuoles in the central area of M cells. Ferritin was exocytosed into the lateral intercellular spaces next to M cells. Uptake of ferritin by intraepithelial cells in the follicle-associated epithelium could not be documented, but ferritin was present in vesicles of subepithelial macrophages.
 ...
PMID:Ultrastructural study of the uptake of ferritin by M cells in the follicle-associated epithelium in the small and large intestines of pigs. 765 79

The uptake of macromolecular and particulate materials in bronchus-associated lymphoid tissue (BALT) in turkeys was examined using transmission electron microscopy. Tracer materials used were live and ultraviolet-killed (UV-killed) Bordetella avium and ferritin. Suspensions of bacteria and ferritin were instilled via intratracheal catheterization and allowed to remain in contact with the respiratory surfaces for 0, 10, 30, 60, 90, and 120 min. Ferritin and B. avium were taken up by both ciliated and non-ciliated cells of the epithelium overlying BALT (BALT epithelium). Ferritin was found in organelles associated with endocytosis (i.e. apical vesicles, endosomes, cytoplasmic vacuoles) and was apparently transported across epithelial cells, since it was also found in intercellular spaces. Bacteria were found in vacuoles within BALT epithelial cells, but not free in intercellular spaces. Some macrophages in BALT epithelium also contained bacteria. No differences were observed between uptake of live and UV-killed bacteria. We conclude that both ciliated and non-ciliated cells of BALT epithelium in turkeys are able to take up macromolecular and particulate materials. Bacteria are also accessible to intraepithelial macrophages, although whether they are taken up directly from the bronchial surface or whether they pass through epithelial cells first could not be determined. This evidence suggests that antigens, including respiratory pathogens, could gain access to cells of the avian immune system by transepithelial passage in BALT.
 ...
PMID:Uptake of ferritin and Bordetella avium in bronchus-associated lymphoid tissue of turkeys. 804 86

A combination of immunohistochemical techniques, a panel of monoclonal antibodies, and computer-assisted morphometric analysis was used to examine the response of the ileal Peyer's patch of fetal lambs 7 days after treatment with ferritin per os. Consistent with previous studies in fetal lambs that have reported the ileal Peyer's patch to be indifferent to antigen, the present study did not find any significant changes in the size of the predominantly B-cell dome/follicle compartment or the predominantly T-cell interfollicular area, nor were differences identified in the distribution of IgM-positive (+), CD4+, and CD8+ cells in these two compartments. However, both compartments showed a significant increase (p < 0.05) in the percentage of area occupied by MHC II+ cells and a significant decrease (p < 0.05) in the percentage of area occupied by CD44+ and B5+ cells. These changes show that the ileal Peyer's patch of fetal lambs is not indifferent to antigen and may represent the transition of a purely primary lymphoid organ to an organ that has both primary and secondary lymphoid functions.
 ...
PMID:Response of leucocyte populations in the illeal Peyer's patch of fetal lambs treated with ferritin per os. 892 64


<< Previous 1 2 3 4 5 6 7 8 Next >>