Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027819 (neuroblastoma)
 27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Putrescine, the end-product of ornithine decarboxylase (ODC: L-ornithine carboxylyase, EC; 4.1.1.17) action, induces the synthesis of a protein(s), in L1210, neuroblastoma, and H-35 cells as well as in rat liver, which inhibits ODC activity. Spermidine and spermine, distal products of ODC activity, also induce the synthesis of a similar protein in H-35 cells. These ODC-inhibitors are heat-labile, trypsin-sensitive, and their induction is dependent upon protein synthesis. They have short half-lives which range from 18 to 66 min; these half-lives are similar to those of the ODC derived from the same source. They are noncompetitive inhibitors of ODC activity with an apparent molecular weight of 26,500. Each inhibitor crossreacts with the ODC's of the other cells and forms an enzyme-inhibitor complex which is stable during Sephadex chromatography; however, after treatment with ammonium sulfate, enzyme and inhibitor activities can be dissociated and recovered intact from the same column. We propose the name antizyme for proteins whose synthesis is induced by the proximal or distal products of the enzyme they inhibit.
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PMID:Induction of a protein inhibitor to ornithine decarboxylase by the end products of its reaction. 106 59

A semiautomated method consisting of digestion of animal feeds in a block digestor and determination of ammonia by ammonia-salicylate reaction has been studied collaboratively, along with the official final action Kjeldahl method, sec. 7.016. Each collaborator analyzed 16 feed samples, tryptophan, ammonium dihydrogen phosphate NBS standard, and ammonium sulfate primary standard. Statistical analysis showed that the 2 methods agreed. The semiautomated method has been adopted as official first action.
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PMID:Collaborative study of a semiautomated method for the determination of crude protein in animal feeds. 124 27

An automated macro Kjeldahl instrument determines per cent protein at the rate of 20 samples/hr. The methodology involved is similar to the present official final action Kjeldahl method, sec. 7.016. The 2 methods were compared in a collaborative study. Sixteen animal feeds, 4 meats, tryptophan, ammonium dihydrogen phosphate NBS standard, and ammonium sulfate primary standard were analyzed by the participating laboratories. The data were agreement between the 2 methods. The automated method has been adopted as official first action for the determination of crude protein in feeds, plants, and cereal foods.
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PMID:Collaborative study of an automated method for the determination of crude protein in animal feeds. 124 29

Microspectrofluorometry was used to study the regulation of intracellular pH (pHi) in 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein (BCECF)-loaded astrocytes and the neuroblastoma-glioma cells of the NG 108-15 line. The cells rapidly regulated pHi during an acid transient induced by an NH4+ prepulse. This regulation was blocked by removal of Na+, or by addition of 1 mM amiloride. The back regulation was also inhibited when extracellular pH (pHc) was lowered. Furthermore, when cells were exposed to buffer with reduced or increased pHc, pHi changed in parallel. Thus, although these cells possess at least one efficient H+ extrusion mechanism, which is likely to be the ubiquitous Na+/H+ antiporter, they fail to regulate pHi to a normal value unless pHc is held constant. The implications of these findings are discussed.
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PMID:The regulation of intracellular pH in cultured astrocytes and neuroblastoma cells, and its dependence on extracellular pH in a HCO3-free solution. 129 78

Scrapie prions are composed largely, if not entirely, of the scrapie prion protein (PrPSc) that is encoded by a chromosomal gene. Scrapie-infected mouse neuroblastoma (ScN2a) and hamster brain (ScHaB) cells synthesize PrPSc from the normal PrP isoform (PrPC) or a precursor through a posttranslational process. In pulse-chase radiolabeling experiments, we found that presence of brefeldin A (BFA) during both the pulse and the chase periods prevented the synthesis of PrPSc. Removal of BFA after the chase permitted synthesis of PrPSc to resume. BFA also blocked the export of nascent PrPC to the cell surface but did not alter the distribution of intracellular deposits of PrPSc. Under the same conditions, BFA caused the redistribution of the Golgi marker MG160 into the endoplasmic reticulum (ER). Using monensin as an inhibitor of mid-Golgi glycosylation, we determined that PrP traverses the mid-Golgi stack before acquiring protease resistance. About 1 h after the formation of PrPSc, its N-terminus was removed by a proteolytic process that was inhibited by ammonium chloride, chloroquine, and monensin, arguing that this is a lysosomal event. These results suggest that the ER is not competent for the synthesis of PrPSc and that the synthesis of PrPSc occurs during the transit of PrP between the mid-Golgi stack and lysosomes. Presumably, the endocytic pathway features in the synthesis of PrPSc.
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PMID:Synthesis and trafficking of prion proteins in cultured cells. 135 22

A protein of neurite outgrowth activity has been identified in porcine seminal plasma after ammonium sulfate precipitation and affinity chromatography on heparin-Sepharose. Upon SDS-PAGE, the polypeptide is shown to have a M(r) of 16,000-18,000. Biologically by induction of neuritic processes on neuroblastoma cells, and immunologically by cross-reaction with specific antisera, this seminal plasma protein differs from acidic fibroblast growth factor (aFGF), basic fibroblast growth factor (bFGF) and nerve growth factor (NGF). The neurite outgrowth activity is relatively stable at pH 3-7 and under denaturing conditions of 8 M urea and beta-mercaptoethanol, but is inactivated by treatment of trypsin. This appears to be a novel protein, enhancing morphological differentiation of neuroblastoma cells in culture.
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PMID:A heparin-binding protein in porcine seminal plasma stimulates neurite outgrowth on neuroblastoma cells in culture. 138 97

1. A new 17-kDa mammalian ribosomal protein (PR17) was purified to homogeneity from the rat exocrine pancreas. The purification procedure was based on acidic extraction of a heat-denatured homogenate, ammonium-sulfate precipitation, hydrophobic chromatography on phenyl-Sepharose and analytical reverse-phase HPLC on mu Bondapak C18. Fractions of interest were collected using an antiserum directed against the first (1-14) moiety of somatostatin (1-28). 30 micrograms pure RP17 were obtained from 1 g fresh pancreas. 2. A short 111-b cDNA encoding RP17 was amplified from rat pancreatic first-strand cDNA template by using two 64-fold degenerate heptadecamer primers in the DNA-polymerase-chain reaction. From the sequence of amplified cDNA, an unambiguous oligonucleotide probe was designed to screen a rat pancreatic cDNA library. A cDNA clone coding for RP17 was isolated, whose nucleotide sequence, with an open reading frame coding for 155 amino acids (molecular mass of 17,199 Da), confirmed the partial amino acid sequences directly obtained from the purified protein. 3. Northern-blot analysis showed that a similar 0.75-kb transcript was present in rat pancreas, in the rat pancreatic acinar cell line AR 4-2J and in the human neuroblastoma cell-line NB-OK-1, the highest level being in the latter two preparations, despite similar levels of RP17 in all three preparations, as tested with a rabbit antiserum directed against purified RP17. 4. The N-terminal sequence of both RP17 and the ribosomal protein YL43 from Saccharomyces cerevisiae (39 amino acid residues) showed a high degree of identity (77%), indicating that RP17 is a mammalian homolog of yeast ribosomal protein YL43.
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PMID:Purification, primary structure and molecular cloning of a rat ribosomal protein showing homology with yeast ribosomal protein YL34. 173 22

A method was developed for the determination of tin in human serum by radiochemical neutron activation analysis, using the long-lived radioisotope Sn(T1/2 = 115.09 days). This radioisotope decays to a daughter isotope 113mIn, the most suitable nuclide for counting (T1/2 = 1.658 h, gamma-ray of 391.7 keV). Experience showed that, with the exception of the serum samples with the lowest tin levels, in the experimental conditions of the present study tin could mostly also be determined by using its radioisotope 117mSn(T1/2 = 13.61 days, gamma-ray of 158.5 keV). Samples were collected and prepared by using the procedure elaborated by the authors, which proved its effectiveness in preventing significant sample contamination on several occasions. Because samples had to be irradiated at 10(14) n.cm-2.s-1, dry ashing was necessary. After irradiation, tin was separated by solvent extraction of tin(IV) iodide from a sulfuric acid-ammonium iodide solution with toluene. The dry ashing and solvent extraction steps were exhaustively tested by means of radioactive tracer experiments whereas the accuracy and precision of the analytical method were thoroughly checked by analyzing biological reference materials (Bowen's kale powder, the NBS' bovine liver, the NBS' nonfat milk powder, and the "second-generation" biological reference material--freeze-dried human serum--for trace element determinations, developed by the authors).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Determination of tin in human blood serum by radiochemical neutron activation analysis. 188 71

Aconitine-modified sodium channels in the neuroblastoma cell membrane were investigated with patch-clamp technique in outside-out configuration. When aconitine (0.1 mmol/l) was present in the pipette solution two types of modified single sodium channels were observed. The first type showed openings with normal amplitude (slope conductance 15.5 pS) and bursting behaviour. The second type of modified channel openings was characterized with low amplitude (slope conductance 2.8 pS) and longer open time as comparing to unmodified channels. The low-amplitude channels were shown to have altered ion selectivity: they were permeable to NH4+. Both populations of aconitine-modified channels could be blocked by tetrodotoxin. In contrast to macroscopic current experiments (Mozhayeva et al. 1977) the development of aconitine modification was not affected by repetitive stimulation and external application of the agent had no effect on single sodium channels in outside-out membrane patch.
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PMID:Aconitine-induced modification of single sodium channels in neuroblastoma cell membrane. 216 97

Screening serum by enzyme-linked immunosorbent assay (ELISA) to paraformaldehyde-fixed neuroblastoma cells revealed spontaneous neuron-reactive antibodies in three strains of autoimmune mice not present in comparable studies of BALB/c mice. Immunoglobulin isolation from pooled sera by either ammonium sulfate precipitation or passage over a protein G column enabled quantitative binding by (1) ELISA to neuroblastoma cells and (2) Western blots of plasma membrane preparations of brain cortex and neuroblastoma cells. The antibodies recognized proteins of apparent molecular weights 101,000, 68,000, 63,000, 57,000, 53,000, 43,000, 39,000, and 31,000 Da on the brain cortex and 63,000, 57,000, and 43,000 Da on the neuroblastoma cell membranes. The class of antibody binding was predominantly IgG in the MRL/lpr and IgM in the NZB/W. Differences between MRL/lpr, NZB/W and BXSB mice were observed although it is not yet apparent if this represents a difference in autoantibody production between the strains.
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PMID:Immunoglobulin binding to neuronal cell surface epitopes in murine systemic lupus erythematosus. 222 4


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