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)

Electrophoretic variants of phosphoglucose isomerase (PGI) in Colias butterflies have been studied from field and laboratory viewpoints. The transmission pattern is that of a dimeric enzyme controlled by one structural gene locus. Populations usually harbor four to six allelic mobility classes. These mobility classes are shared among species complexes, though their frequencies differ widely. Preliminary Ferguson plot analysis of the variants has been carried out. Purified preparations of Colias PGI alleles are more effective in standardizing Ferguson plots than heterologous proteins, such as ferritin. Variation of Ferguson plot parameters is not an infallible guide to electrophoretically "cryptic alleles," as one putative case proved to be due to nonallele-specific effects. S, M, and F mobility classes in two Colias semispecies show the same retardation coefficients in Ferguson plots. Adults early in the flight periods of their nonoverlapping generations show genotype frequencies in Hardy-Weinberg equilibrium, but heterozygote excess develops as the insects age. Simple directional selection and large-scale population mixing are unlikely to be causes of this, although several other selection modes remain possible. Identical-by-descent lines of the four frequent-to-common alleles in C. eurytheme have been set up in culture, and enzyme has been purified from these for study of functional properties. Major differenecs in heat stability and in various kinetic parameters are found among the ten possible genotypes. In some cases, heterosis for kinetic parameters is seen; in other cases, opposing trends in kinetic function and heat stability create potential for net heterosis in function. Possible interpretations of these results in an adaptive metabolic context are discussed, and directions for further work are stated.
Genetics 1977 Sep
PMID:Adaptation at specific loci. I. Natural selection on phosphoglucose isomerase of Colias butterflies: Biochemical and population aspects. 91 29

The electron-dense tracers ferritin, and iron-dextran, and the protein horseradish peroxidase, have been used to investigate the ultrastructural basis of permeability in the upper and lower segments of the Malpighian tubules of Glomeris marginata. All these materials were able to cross the basal lamina and enter the tubule lumen of the upper segment, and it was established that horseradish peroxidase was able to enter the channels which interrupt the apical junctions. In the upper segment, ferritin, iron-dextran, and horseradish peroxidase are taken up and accumulated within intracellular vesicles. In the lower segment ferritin and iron-dextran enter the cells but become generally distributed over the cytoplasm, as well as entering membrane-bounded vacoules. The behaviour of horseradish peroxidase could not be assessed by owing to the presence of endogenous peroxidase activity in the cells. After fixation by direct application of glutaraldehyde to the undissected tubules, the extracellular spaces contained large numbers of membrane-bounded vesicles. The significance of these observations is discussed in relation to the physiological activities of the tubules.
Cell Tissue Res 1977 Sep 05
PMID:Ultrastructural tracer studies on the permeability of the Malpighian tubule of the pill millipede, Glomeris marginate (Villers). 92 20

The iron status of a population of 1564 subjects living in the northwestern United States was evaluated by measurements of transferrin saturation, red cell protoporphyrin, and serum ferritin. The frequency distribution of these parameters showed no distinct separation between normal and iron-deficient subjects. When only one of these three parameters was abnormal (transferrin saturation below 15%, red cell protoporphyrin above 100 mug/ml packed red blood cells, serum ferritin below 12 ng/ml), the prevalence of anemia was only slightly greater (10.9%) than in the entire sample (8.3%). The prevalence of anemia was increased to 28% in individuals with two or more abnormal parameters, and to 63% when all three parameters were abnormal. As defined by the presence of at least two abnormal parameters, the prevalence of iron deficiency in various populations separated on the basis of age and sex ranged from 3% in adolescent and adult males to 20% in menstruating women. It is concluded that the accuracy of detecting iron deficiency in population surveys can be substantially improved by employing a battery of laboratory measurements of the iron status.
Blood 1976 Sep
PMID:Evaluation of the iron status of a population. 95 65

In the presence of serum-containing medium, BHK cells attached and spread during a 1-h period onto a 3-5 nm thick serum layer absorbed on the substratum surface. The closest approach of the plasma membrane to the serum layer was observed to be about 9nm, which was determined by tilting the sectioned cells in a goniometer holder. Bundles of microfilaments or other cytoplasmic specializations were not observed in association with the regions of close contact. However, in the space between the plasma membrane and the adsorbed serum layer, a diffusely stained material could be visualized after fixation/staining by the tannic acid-glutaraldehyde technique. This technique also permitted increased clarity of visualization of trilaminar appearance of the plasma membrane. The distribution and mobility of anionic sites on the surfaces of attached and spreading cells was determined by labeling with polycationic ferritin. We observed movement of polycationic ferritin into large clusters on the cell surface, collapse of cell surface microextensions, and endocytosis, all of which were similar to our previous findings utilizing cells in suspension. However, the absolute amount of ferritin bound to the upper cell surface was less than that previously observed when suspended cells were put under similar labeling conditions. Also, polycationic ferritin did not appear to penetrate between the lower cell surface and the substratum.
J Cell Biol 1976 Sep
PMID:Initial attachment of baby hamster kidney cells to an epoxy substratum. Ultrastructural analysis. 95 72

The Fleischer ring of keratoconus was studied with the transmission electron microscope in four corneal buttons. The ring was characterized by accumulations of ferritin particles in the widened intercellular spaces and/or in the cytoplasmic vacuoles of the corneal epithelium. Both changes were prominent in basal layers in three cases; in one case, ferritin-containing vacuoles were noted in wing cell layers. Ferritin particles were also scattered over the corneal epithelium in all cases. For comparison, normal human corneas and conjunctivas were studied. Ferritin particles were scattered over the corneal epithelium and throughout the basal cells of the conjunctiva. They were not found in corneal stroma or endothelium. In conjunctival stroma, numerous ferritin particles were observed in the cytoplasm of some macrophages. Possible origin of these particles and the cause of their deposition are discussed.
Arch Ophthalmol 1976 Sep
PMID:Electron microscopical study of the Fleisher ring. 96 67

The concentration of circulating ferritin was measured in 250 normal adult women and 229 women presenting with early breast cancer. Ferritin concentrations are higher in cancer patients than in normal women. Patients with an intial circulating ferritin concentration above 200 mug/1 have a higher tumour recurrence rate during the subsequent 4 years.
Br J Cancer 1976 Sep
PMID:Serum ferritin concentration in early breast cancer. 97 2

The 4S RNA genes in HeLa mitochondrial DNA (mtDNA) have been mapped by electron microscopy using the electron-opaque label ferritin. This method is based on the high affinity interaction between the protein, avidin,and biotin. 4S RNA, covalently coupled to biotin, was hybridized to single-stranded mtDNA. The hybrids were then labeled with ferritin-avidin conjugates. The positions of ferritin-labeled 4S RNA genes were determined relative to the rRNA genes on both heavy (H) and light (L) strands of mtDNA. This region was recognized as a duplex segment after hybridization either with rRNA in the case of H strands or with DNA complementary to rRNA in the case of L strands. Our studies suggest that at least nineteen 4S RNA genes are present in the HeLa mitochondrial genome. On the H strand, we have confirmed the nine map positions found in a previous electron microscope mapping study (Wu et al., 1972) and obtained evidence for three additional 4S RNA genes. On the L strand, seven 4S RNA genes have been mapped. The nineteen genes are distributed more or less uniformly around the genome. There is a pair of closely spaced genes, approximately 150 nucleotides apart, on the H strand, and another closely spaced pair on the L strand.
Cell 1976 Sep
PMID:An electron microscope study of the relative positions of the 4S and ribosomal RNA genes in HeLa cells mitochondrial DNA. 97 42

Using immune electron microscopy, an attempt has been made to visualise viral particles in Crohn's disease tissue and faeces. No particles resembling viruses were observed, but in the absence of a specific antiserum a negative result does not exclude the presence of a virus, particularly if it is sparsely distributed. Compared with controls, an abundance of a 12 nm particle was found in all Crohn's disease tissue and one small intestinal lymphoma. This particle has been identified as ferritin and is unlikely to be of aetiological significance.
Gut 1976 Sep
PMID:Ferritin in Crohn's disease tissue: detection by electron microscopy. 97 10

We have examined the role of receptor clustering in intact erythrocyte membranes exhibiting enhanced lectin-mediated cell agglutination by analyzing freeze-fracture and freeze-etch images of human erythrocytes labeled with ferritin-conjugated soybean agglutinin. We find that trypsinization and fixation of intact erythrocytes, in either order, causes no alteration of the random distribution of ferritin-conjugated soybean agglutinin on the surfaces of these cells as compared to their distribution on the surfaces of fixed erythrocytes and untreated erythrocyte ghosts. Furthermore, clustering of the intramembranous particles in the membrane of intact erythrocytes was not found with any of the cells described above. We conclude that clustering of the soybean agglutinin receptors is not a major factor involved in the enhanced agglutination of intact trypsinized erythrocytes. Caution is necessary in transferring information obtained with erythrocyte ghosts, where clustering can be induced, to intact erythrocytes.
Biochim Biophys Acta 1976 Sep 21
PMID:Receptor distribution and the mechanism of enhanced erythrocyte agglutination by soybean agglutinin. 98 34

The specific antiserum against a type of ferritin that is especially common to leukemia cells and the placenta was used to test, by countercurrent immunoelectrophoresis, sera from humans with various diseases. The best results were obtained with leukemia; patients with chronic myelogenous leukemia in blastic phase, acute myelogenous leukemia, lymphogenous leukemia, and unclassifiable juvenile leukemia frequently showed a positive reaction, but patients with chronic myelogenous leukemia in static phase did not. The average incidence of positive reaction among all leukemia patients was 54.0%. Patients with other malignant tumors (i.e., multiple myeloma, malignant lymphoma and carcinomas of the stomach, rectum, and liver) also often showed a positive reaction. The average incidence of positive reaction among all the patients with malignant diseases of the hematopoietic system, except for leukemia, was 34.3%, and that among patients with nonhematologic malignant neoplasms was 36.8%. However, the incidence of a positive reaction in patients with benign diseases and healthy individuals was less than 3%.
J Natl Cancer Inst 1975 Sep
PMID:Antiserum against leukemia cell ferritin as a diagnostic tool for malignant neoplasms. 105 55


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