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)

Small and medium lymphocytes from the peripheral blood and lymphoid tissues of the rabbit react in suspension with antibodies directed against different immunoglobulin determinants. Through immunofluorescence, it was possible to show that numerous discrete spots on the surface of the positive lymphocytes carry immunoglobulin molecules. The positive lymphocytes are about one-half of all lymphocytes in the different preparations; thymus lymphocytes are all negative. With antisera specific for rabbit IgM as well as with antisera directed against allotypic determinants specific for IgM or IgG, it was possible to show that about nine-tenths of the immunoglobulin-positive lymphocytes carry IgM molecules on their surface. With antisera directed against a- and b-locus determinants, it was also possible to demonstrate that both heavy and light chains were present in the surface immunoglobulins. Furthermore, in animals which were heterozygous at the a or the b locus, it was found that each lymphocyte had immunoglobulins synthesized under the influence of only one of two alleles. A very small proportion of lymphocytes could be shown to have a specific surface reaction with one antigen (horse ferritin); the proportion of these cells increased very much after immunization.
 ...
PMID:Immunoglobulin spots on the surface of rabbit lymphocytes. 491 41

Surface immunoglobulin-bearing cells were selected from suspensions of human tonsil cells by the reverse immune cytoadherence technique. The method employed a hybrid antibody directed against Ig on lymphoid cells and against ferritin bound to sheep red blood cells (SRBC). Only 6% of the cells formed rosettes. When subjected to electron microscopy they were shown to consist of a morphologically heterogeneous population of cells. However, most cells in the center of rosettes showed ribosome-associated endoplasmic reticulum (RER) and polyribosomes. Usually these organelles were located in close proximity to membrane sites where a 400-600 A bridge was resolved between the lymphocyte and the ferritin particle on the SRBC. The bridge is postulated to consist at least in part of Ig. Only 50% of the plasma cells formed rosettes and bridges could not be resolved. The surface of the plasma cells within rosettes differed from that of plasma cells which had not reacted with ferritin-coated sheep erythrocytes. The incidence of plasma cells and gamma-globulin-bearing lymphoid cells was corroborated with the help of fluorescent antibody techniques.
 ...
PMID:Electron microscope study of surface immunoglobulin-bearing human tonsil cells. 506 76

Simultaneous detection of specific surface markers by immunogold and intracellular peroxidase activity was determined ultrastructurally in normal and leukaemic progenitors of platelets, erythrocytes and granulocytes. A new method of fixation was employed to preserve platelet peroxidase activity. Monoclonal antibodies to platelet glycoproteins labelled exclusively platelet peroxidase (PPO) positive cells, i.e. platelets, megakaryocytes and promegakaryoblasts (PMKB). In acute megakaryoblastic leukaemia, most PMKB possessed both markers while a few PMKB identified by PPO did not bind monoclonal antibodies. This result suggests that PPO appears earlier in maturation than platelet glycoproteins. Although all glycoproteins (GP) displayed fewer sites in PMKB than platelets, GP Ib was often observed in more mature megakaryocytes. Surface (glycophorin A) and intracytoplasmic markers including ferritin, intra-mitrochondrial iron and diffuse peroxidase activity due to haemoglobin of erythroid progenitors, appeared simultaneously. The number of glycophorin A sites increased with maturation. In leukaemia involving PMKB and proerythroblasts, the surface markers were coincident with the localization of peroxidase activity; glycophorin A was always absent from blasts which exhibited PPO activity localized in endoplasmic reticulum. Platelet glycoproteins were never expressed in any other cell lineage. The myeloid surface antigen was present on normal late neutrophilic promyelocytes after the cessation of myeloperoxidase synthesis. In some cases of M1 and M2 AML (FAB classification), labelling was identical to normal cells while in others the antigen appeared earlier than normal. Our findings show that the surface phenotype of blasts from non-lymphoid leukaemia and the intracellular peroxidase activity of a given cell type can be simultaneously demonstrated and analysed by electron microscopy.
 ...
PMID:Simultaneous detection of membrane markers with monoclonal antibodies and peroxidatic activities in leukaemia: ultrastructural analysis using a new method of fixation preserving the platelet peroxidase. 609 46

Within the epithelium that overlies the dome regions of Peyer's patches, exist specialized surface epithelial cells (M) which function to take up macromolecules from the gut lumen. These cells may be of great importance in processing antigenic material in the gut. The predominant lymphoid structures of the small intestine are isolated lymphoid follicles, by virtue of their frequency. These follicles are difficult to study because they are not grossly visible. In the present study, three guinea pigs drank India ink mixed into their water for 1, 3, and 5 months. Two hours prior to sacrifice, animals were given an intraintestinal injection of ferritin or India ink. Using a hand lens, the Peyer's patches and isolated follicles were clearly identified among the villi of the intestine. Light microscopy revealed ink in the surface epithelium covering the isolated follicles and within the substance of the follicles. Transmission electron microscopy demonstrated M cells over isolated follicles and Peyer's patches. These cells had lighter staining cytoplasm, while the mitochrondria stained darker with prominent cristae, and the microvilli were shorter. Therefore, M cells do exist within isolated follicles and structurally appear the same as those found in Peyer's patches. This implicates the isolated follicles in the overall antigen processing role of gut-associated lymphoid tissues. The present method facilitates identification of isolated lymphoid follicles which will allow functional studies to be performed on these structures.
 ...
PMID:Demonstration of M cells in the specialized follicle-associated epithelium overlying isolated lymphoid follicles in the gut. 620 May 55

Six peripheral blood lymphoid fractions (total lymphocytes, non-T, T, Tar (autologous rosette-forming T cells/precursor), T mu (helper), and T gamma (suppressor) lymphocytes) isolated through rosetting procedures were examined for the presence of ferritin by a direct immunofluorescence technique. Although ferritin was present in all lymphoid fractions studied, a significantly higher proportion of ferritin-containing cells were detected in the T-cell fraction than in the non-T-cell fraction, (mean +/- SD = 7.9 +/- 1.6% and 5.0 +/- 1.2%, respectively). T mu- and T gamma-cell fractions showed a twofold increase in the number of ferritin-positive cells (14.1 +/- 1.4% and 15.4 +/- 2.6%, respectively), as compared with Tar (7.0 +/- 0.9%)-and total lymphocyte (6.9 +/- 1.3%)-cell fractions. These results indicate that ferritin is preferentially distributed in T mu and T gamma lymphocytes and may constitute the basis for explaining some of the roles exercised by these cells in the control of other biological systems.
 ...
PMID:Ferritin in normal human peripheral blood T-lymphocyte subpopulations. 623 11

In order to better understand the mechanism of lymphocyte surface receptor redistribution induced by externally added ligands, polycationized ferritin (PCF), a nonconventional ligand, was tested using both fluorescence and electron microscopy for its ability to cause patching and capping of anionic molecules on the surface of both transformed and normal mouse lymphocytes. Binding of PCF at 0 degree C for 1 hour induces the appearance of patches; subsequent incubation at 37 degrees for 30--60 minutes causes the formation of a cap structure with the lymphoid cells tested (T-lymphoma cells and splenic lymphocytes). Using various experimental treatments (e.g., sodium azide, cytochalasin B and D, colchicine, prefixation, and cold temperatures), PCF-induced capping has been found to be temperature sensitive, and to require metabolic energy and an intact cytoskeletal system. In addition, using double immunofluorescence techniques which involve rhodamine-labeled PCF and fluorescein-conjugated heavy meromyosin, it has been observed that the formation of the PCF-induced cap coincides with an accumulation of intracellular actin directly beneath the cap structure. Furthermore, agents such as dibutyryl cyclic AMP and theophylline, which cause an increase in intracellular cyclic AMP, have been shown to stimulate PCF-associated capping. This study suggests that increasing levels of intracellular cyclic AMP may activate, directly or indirectly, membrane-associated contractile elements required for the aggregation of membrane proteins into patches and caps.
 ...
PMID:Lymphocyte capping induced by polycationized ferritin. 625 11

The distribution and density of receptors for concanavalin A (Con A) on the surfaces of cells of intact and isolated popliteal and axillary lymph nodes were investigated in the rabbit. Intact lymph nodes were perfused via the subcapsular (marginal) sinus with either Con A peroxidase or Con A ferritin, fixed with glutaraldehyde, and processed for electron microscopy. Both Con A peroxidase and Con A ferritin were distributed on the plasmalemma of lymphocytes, macrophages, neutrophils, plasma cells, reticular endothelial cells, and the vascular endothelium. Counts of Con A-conjugated ferritin particles indicated that the density of Con A receptors was generally similar for lymphocytes, macrophages, and neutrophils but lower on plasma cells. When lymph node cells were isolated by mechanical methods and exposed to Con A ferritin, the label was homogenously distributed on the cell surfaces of most cells. However, Con A binding was significantly higher on the surface of isolated cells than in the intact node. It is suggested that the increase in density of Con A binding sites on isolated cells may possibly be due to an unmasking of cell surface moieties in which additional Con A receptor sites become available as a result of the isolation procedure. The density of Con A ferritin binding sites was also significantly lower on the surface of isolated plasma cells than the lymphocyte and macrophage, suggesting that the density distribution of cell surface saccharides is different for various lymphoid cells.
 ...
PMID:Concanavalin A receptor sites on lymph node cells in vivo and in vitro. 629 43

The monoclonal antibody OKT9 (a known transferrin receptor antibody) and a monoclonal antibody to transferrin (ATfn) were used to localize the transferrin receptor and transferrin on marrow cells. After incubation of cell suspensions with the antibody, the cells were reacted with an affinity purified Fab fragment of goat anti-mouse IgG conjugated to horseradish peroxidase (GAM-HRP), which was in turn visualized by reaction with 3,3'-diaminobenzidine (DAB). Erythroblast cell surfaces stained intensely with OKT9-GAM-HRP-DAB, weaker staining was observed on reticulocyte surfaces, whereas erythrocyte surfaces lacked staining. Staining was present on surface caveolae, which often contained endogenous ferritin particles. Moderate to strong OKT9 staining was observed on less than 10% of presumed lymphoid cells. Monocytes, macrophages, promyelocytes, granulocytes, megakaryocytes and platelets consistently lacked OKT9 staining. ATfn-GAM-HRP-DAB staining of erythroid cells was similar to that observed with OKT9 staining; however, in contrast to the latter staining, ATfn stained the surfaces of megakaryocytes, platelets, monocytes and most lymphocytes. Promyelocytes stained weakly, whereas late granulocytes lacked staining. These results indicate that the T9 transferrin receptor (1) is largely confined to erythroid cells in marrow, (2) is diffusely distributed on the surface of early erythroid cells, (3) decreases with cell maturation, and (4) is lost when haemoglobin synthesis is completed. Transferrin appears in a similar distribution on erythroid cell surfaces but also appears to bind to some cell surfaces lacking the T9 receptor.
 ...
PMID:Ultrastructural localization of the transferrin receptor and transferrin on marrow cell surfaces. 630 35

Surface labeling and internalization of insulin was demonstrated ultrastructurally with human peripheral lymphocytes and with "activated"/transformed lymphocytes from mitogen-treated cultures using the colloidal gold-labeled insulin-bovine serum albumin (GIA) procedure. The majority of peripheral lymphocytes bound only limited amounts of the insulin complex, while approximately 15% of the lymphocyte population bound modest to comparatively large quantities of the labeled hormone. Quantitative labeling data indicated a skewed GIA labeling continuum for peripheral lymphocytes rather than separate, distinct populations. Sequential labeling studies with the GIA complex followed by either the ferritin-conjugated goat anti-human immunoglobulin or the E-rosette techniques indicated that insulin labeling was neither T nor B cell specific, since extremes of GIA labeling were found in both populations. Many, but not all, circulating lymphocytes with elevated insulin binding had morphological features suggestive of "active" cells, viz., larger cell, nuclear, nucleolar, and Golgi sizes, dispersed chromatin, and greater numbers of polysomes than lymphocytes having minimal GIA labeling. Both phytohemagglutinin (PHA), a T-cell mitogen, and pokeweed mitogen (PWM), a B/T cell mitogen, induced an increase in mean GIA labeling of cultured lymphoid cells as compared to non-mitogen-treated controls. The majority of mitogen-transformed "blast-like" cells had more extensive insulin labeling than nontransformed small (medium)-size lymphocytes, although an overlap in labeling densities was noted in these two groups. PHA induced a slight increase in mean surface GIA labeling of the nontransformed lymphocyte population at 48 and 72 hr of culture as compared to similar cells in non-mitogen-treated controls and PWM cultures. We interpret these findings as indicating the emergence of increased numbers of insulin binding sites on lymphocytes, both those in the circulation and in mitogen-treated cultures, during the early response (activation) to functional and/or metabolic modulations of the cell; this surface change does not appear to be directly related to blastogenic transformation.
 ...
PMID:Insulin complex binding to human peripheral and mitogen-stimulated lymphocytes. 637 Nov 32

Serum ferritin was determined by immunoradiometry in children aged 6 months to 3 years, immediately before leaving hospital where they had been treated for various acute, non-haematological diseases. A low value was found in 13% of them. Serum ferritin concentration is a sensitive method in differentiating between iron deficiency and infectious anaemia. A significantly higher mean value was found in children affected by malignant disease (acute lymphoid or myeloid leukaemia, various solid tumours).
 ...
PMID:Serum ferritin level in infants and children with anaemia and malignant disease. 657 72


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