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

Live sporangiophores of Phycomyces blakesleeanus were centrifuged at 35,000 rpm. The cell contents sedimented into distinct layers, and each layer was studied with an electron microscope and with cytochemical methods. The following layers were found (their volumes and their densities are shown in Fig. 3): 1. polyphosphates; 2. polyphosphates and protein crystals; 3. glycogen; 4. yellow layer with ferritin; 5. ribosomes; 6. protein crystals; 7. mitochondria; 8. mitochondria and fibrils; 9. nuclei; 10. endoplasmic reticulum; 11. vesicles, membranes, and reticulum; 12. vacuole; 13. lipoproteins, membranes; 14. fat droplet. The densities of the various layers were determined by the injection of droplets of inert oils of known density into the sporangiosphores before centrifugation. Sedimented cell organelles could be isolated. Centrifuged nuclei of a lycopene-producing mutant were injected into the intact sporangiophore of an albino host where they induced color formation. The ensuing spores, when plated, gave a mixture of white and colored colonies. It was concluded that cell organelles, sedimented by centrifugation of living sporangiophores, remain alive and can be used for biochemical studies. Microspectrophotometric examination of the layers indicated the presence of cytochromes and flavines in the mitochondria and of cytochromes in the nuclei. No pigments corresponding to the action spectrum for the light growth response were found.
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PMID:Intracellular centrifugal separation of organelles in Phycomyces. 578 70

The intracellular pathway of an enzyme resistant GnRH agonist (D-Lys6-GnRH) conjugated to ferritin or to colloidal gold was followed in cultured pituitary cells. After an initial uniform distribution over the cell surface of gonadotropes, the electrondense marker was internalized, either individually or in small groups. Some, but not all marker was associated with invaginated membrane specializations showing a proteineous coat at their cytoplasmic site. After longer incubation times, the marker appeared in the lysosomal compartment and the Golgi apparatus, where it could be found in the vesicular as well as cisternal portion. In addition, the receptor-mediated endocytosis of the GnRH antagonist D-p-Glu1-D-Phe2-D-Trp3-D-Lys6-GnRH was studied by light and electron microscopic autoradiography after 30 and 60 min of incubation to ensure uptake. At both time points, in in vitro as well as in vivo studies, silver grains were localized over cytoplasmic organelles of castration cells, including dilated endoplasmic reticulum, lysosomes, and clear vesicles. No consistent association with cell nuclei, mitochondria, or secretory vesicles could be observed. The results suggest that both agonist and antagonist are binding selectively to the plasma membrane of gonadotropes and subsequently are taken up via receptor-mediated endocytosis for degradation or possible action on synthetic processes.
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PMID:Receptor-mediated binding and uptake of GnRH agonist and antagonist by pituitary cells. 609 Oct 67

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.
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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

An ultrastructural survey of peripheral blood lymphocytes in 81 patients with chronic lymphatic leukemia (CLL) demonstrated intracytoplasmic inclusions in 15 of them. These inclusions consisted of round, dense bodies, ferritin deposits, lipid-containing bodies, concentric rings of endoplasmic reticulum, microfibrillar formations and crystalloid inclusions. The variety of these inclusions suggests that cases diagnosed by light microscopy as classical CLL are actually subtypes which may differ in their clinical course and ultimate prognosis.
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PMID:Intracytoplasmic inclusions in the peripheral blood lymphocytes of patients with chronic lymphatic leukemia. 613 75

The present observations describe the endocystosis and intracellular transport in the endothelial cells lining the sinuses of the rat liver and occurring 3 min after intravenous administration of two protein tracers: horseradish peroxidase and ferritin. Internalization of the proteins is exclusively by bristle coated pits followed by intracellular sequestration in bristle coated vesicles (diameter 90-210 nm). No other form of endocytosis is present in the endothelial cells of the liver sinuses. The bristle coated vesicles fuse with smooth membrane lined tubules (diameter 20-70 nm) termed transfer tubules. In this way the tracers are deposited into the lumens of the transfer tubules. The transfer tubules in turn fuse with preexisting electron-lucent endosomes which then receive the protein markers. In addition, direct fusion of bristle coated vesicles with endosomes occurs in limited measure. Bristle coated vesicles may fuse with other bristle coated vesicles while losing their clathrin coat, resulting in the formation of new endosomes which may enlarge through fusion with additional bristle coated vesicles or perhaps also with transfer tubules. The sinus endothelium also contains lysosomal vesicles which appear as dense bodies or multivesicular bodies. No protein tracers have been observed in these dense bodies at the time interval (i.e., 3 min) examined. Neither has a direct fusion between endosomes and lysosomes been found. The transfer tubules may be continuous with or may be derived from cisternae of the Golgi complex. No luminal continuity between transfer tubules and endoplasmic reticulum has been observed. The sinus endothelium also contains small bristle coated vesicles (30-40 nm) often attached to Golgi cisternae. These do not participate in the transport of endocytosed protein tracer and are in this respect functionally distinct from the large bristle coated vesicles derived from the endothelial plasmalemma. Serial sections show that there are extensive connections between the endocytic transport organelles: bristle coated vesicles, transfer tubules, and endosomes, possibly forming an intracellular luminal continuum.
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PMID:In vivo endocytosis by bristle coated pits of protein tracers and their intracellular transport in the endothelial cells lining the sinuses of the liver. I. The endosomal disposition. 614 1

Hyaline bodies of odontogenic cyst were examined by histological, histochemical and electron microscopic observations. They were seen only in odontogenic cysts and their prevalence was 6.9% in 576 cases of the cysts. They occurred most frequently within the epithelial lining, but a few bodies were observed in the connective tissue walls. Histochemical reactions of hyaline bodies were similar to those of dental cuticles, but differed from keratin. Ultrastructurally, hyaline bodies were typed into two forms: lamellated and homogeneous. The lamellated bodies were composed of alternate electron-dense and electron-lucent layers. The homogeneous bodies were occasionally formed around granular material, mineralized masses and cholesterol clefts. Hyaline bodies adjoined epithelial cells via a basal lamina-like structure and half-desmosomes. Epithelial cells containing well-developed, rough surfaced, endoplasmic reticulum were seen adjacent to hyaline bodies. Ferritin-like granules were found in the cytoplasm of epithelial cells near hyaline bodies. By electron probe X-ray microanalysis, inorganic elements within the ferritin-like granules were the same in constitution as those in the outermost electron-dense layer of the lamellated bodies. By scanning electron microscopy, hyaline bodies displayed ellipsoidal and stick-like shapes. The present study suggested that hyaline bodies are particular products formed by odontogenic epithelium.
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PMID:Hyaline bodies of odontogenic cysts: histological, histochemical and electron microscopic studies. 616 Feb 29

Extra- and intracellular distribution of Prostatic Binding Protein (PBP) was studied in the different genital organs of the male rat by immunocytochemistry at the light and electron microscopic levels. PBP was extracted from cytosols of rat ventral prostate and used for immunization of rabbits. The specificity of the antiserum raised was tested by "western blotting" and immunoelectrophoresis. From the different fixatives tested for optimal structural and antigenic preservation of the ventral prostate a mixture containing 2.5% paraformaldehyde, 0.5% glutaraldehyde and 0.5% CaCl2 in cacodylate buffer, 0.05 M, pH 7.3 was selected. Using the immunofluorescence technique and the unlabeled antibody enzyme method PBP-immunoreactivity was detected at the light microscopic level in the luminal secretions of the ventral prostate. No reaction was observed with the seminal vesicle, the coagulating gland, the dorsal and lateral prostates, the epididymis and the testis. Intracellular secretory granules reacting with PBP antiserum were exclusively found in the secretory cells of the ventral prostate. Insufficiently fixed cells showed a diffuse generalized reaction of the cytoplasm indicating a leakage of the antigen from the secretory granules. Such artifacts were common in tissue sections processed with the preembedding-staining procedure. At the ultrastructural level therefore mostly the postembedding staining method was performed using both the unlabeled antibody enzyme method and the ferritin-labeled immunoglobulin technique in osmicated, Epon-embedded tissue. Labeling with either method was intense in the secretory granules and the condensing vacuoles, while the labeling density of the rough endoplasmic reticulum and the Golgi cisternae was in the background range. Castration experiments showed that secretory material displaying PBP immunoreactivity was retained within the acinar lumen of the gland for several days after castration, but was absent from most secretory cells already by four days after castration. Immunocytochemistry of PBP therefore is a very sensitive method for analysing the secretory activity and its androgen dependence of the prostate of the rat.
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PMID:Intracellular localization of Prostatic Binding Protein (PBP) in rat prostate by light and electron microscopic immunocytochemistry. 618 15

The localization of foot-and-mouth disease viral-induced RNA polymerase has been determined in situ and in partially fractionated cell components by using polymerase antisera tagged with either peroxidase or ferritin. Electron microscopic examination revealed the polymerase to be heavily concentrated on membranes of the smooth membranous vacuoles (SMV) which are newly formed during infection and which were previously shown to be the site where newly synthesized viral RNA appeared. Polymerase antigen was also seen to be associated with the endoplasmic reticulum (ER), the assumed site of original synthesis, and to a lesser extent with mitochondria and the Golgi apparatus. There was no significant polymerase attachment to nuclear and plasma membranes.
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PMID:Association of foot-and-mouth disease virus induced RNA polymerase with host cell organelles. 631 90

The subcellular location of class I H-2 histocompatibility antigens was determined for mouse liver using immunocytochemical techniques and correlated with information determined by cell fractionation and analysis in situ. Surface antigens first were localized by standard procedures involving surface labeling with ferritin-labeled antibody. This approach could not be used for internal membranes either in situ or in fractions since the antigens are not expressed at the cytoplasmic surface. For this purpose, thin sections of tissues embedded in Lowicryl were analyzed and quantitated. The in situ analysis confirmed the presence of H-2 antigens on internal membrane compartments as well as on the cell surface and helped rule out the possibility that distributions based on analyses by immunoprecipitation of fractions of internal membranes were influenced greatly by plasma membrane contamination. Quantitation was provided by immunoprecipitation of H-2 antigens from radioiodinated or metabolically labeled isolated and highly purified cell fractions. The findings establish the presence of class I H-2 histocompatibility antigens in endoplasmic reticulum, Golgi apparatus and plasma membrane in the approximate ratios of 1:3:7. No class I H-2 histocompatibility antigens could be detected in mitochondria, salt extracts of isolated membranes or NP-40-insoluble membrane material.
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PMID:Immunocytochemical localization of class I H-2 histocompatibility antigens of mouse liver. 633 41

Recently, significant advances have been made in characterizing the pathway of elastin biosynthesis from the biochemical point of view and a 70,000 dalton protein, designated tropoelastin, appears to be the primary translation product and soluble intermediate of the insoluble elastin. However, relatively little is known concerning the intracellular secretory pathway of tropoelastin. We previously developed an electron microscopic technique using elastin-specific antibody and ferritin-conjugated secondary antibody to identify intracellular elastin and to identify, provisionally, intracellular vesicles containing elastin ( Damiano et al., Conn. Tiss . Res. 8: 185-188, 1981). However, the method did not permit localization of elastin in other intracellular organelles. We now describe an improved post-embedding technique using the peroxidase-antiperoxidase method to detect the primary elastin antibody and have localized elastin in both the endothelial and medial cells of the embryonic chick aorta. Specific staining was visualized in the cisternae of the endoplasmic reticulum, in the Golgi apparatus, and in vesicles forming on the trans side of the Golgi. Some of these smaller vesicles appeared to fuse, forming larger vesicles which may have a storage function. Both types of vesicles were seen fusing with the cell plasma membrane, suggesting that elastin is secreted by an exocytotic process. These results suggest that tropoelastin follows the classical pathway for protein secretion.
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PMID:Secretion of elastin in the embryonic chick aorta as visualized by immunoelectron microscopy. 637 17


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