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)

In neuroblastoma, N-myc amplification has been found to be strikingly associated with rapid tumour progression and poor prognosis. Recent studies have demonstrated that cell proliferative activity also significantly predicts the clinical outcome in patients with neuroblastoma. In order to define the correlation between N-myc amplification and cell proliferation rate, in the present investigation the two parameters were first assessed in 48 neuroblastoma tumours. N-myc amplification was evaluated in frozen specimens by Southern-blot analysis using the NB 19-21 probe and it was detected in nine patients. Cell proliferative activity was determined by measuring the AgNOR protein area in histological sections selectively stained by silver. The mean AgNOR protein area value of neuroblastomas with N-myc amplification (3.63 +/- 1.62 microns2) was not significantly different from that of neuroblastomas without N-myc amplification (2.46 +/- 1.57 microns2; P = 0.30). On the other hand, both N-myc amplification and AgNOR protein expression were found to be significantly related to the clinical outcome of the disease (P < 0.001 and P = 0.0143, respectively; median follow-up time = 47 months; range 18-106 months). In a second set of experiments, the relationship between N-myc amplification and cell proliferation rate was assessed in seven established human neuroblastoma cell lines. N-myc amplification was found to be completely independent of the population doubling time (DT), which, on the contrary, was strictly related to the quantitative expression of AgNOR protein (r = -0.947; P < 0.001). Altogether, the present results indicate that N-myc amplification and cell proliferation rate are not interrelated in neuroblastoma, each representing an independent biological parameter of cancer cells associated with the clinical behaviour of the disease.
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PMID:N-myc amplification and cell proliferation rate in human neuroblastoma. 942 91

An isomaltotriose-producing endo-dextranase was simply purified from cell-free culture broth of a Fusarium sp. by ethanol fractionation and consecutive column chromatographies using DEAE-Toyopearl and Bio-Gel P-100. The purified enzyme was judged to be homogeneous on PAGE and SDS-PAGE as well as isoelectric focusing. The molecular mass of the enzyme was estimated to be about 69 kDa by SDS-PAGE. The enzyme is an acidic protein with a pI of 4.6. The optimum pH and temperature were pH 6.5 and 35 degrees C, respectively. The enzyme was completely stable over the range of pH 4.5-11.8 at 4 degrees C for 24 h and at temperatures below 45 degrees C. Inactivation of the enzyme was found to be partial with 5 mM Cu2+, being about 70% inhibition and complete with 5 mM of Fe3+, Hg2+, Ag+ or NBS. The enzyme split dextran in an endo-lytic action to produce a large amount of isomaltotriose and a slight amount of isomaltose and glucose. The anomeric configurations of the reaction products formed by the enzyme were alpha-form, indicating that the alpha-glycoside linkages in the substrate are retained. The final yield of isomaltotriose from dextran T-2000 was about 62%.
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PMID:Purification and characterization of an isomaltotriose-producing endo-dextranase from a Fusarium sp. 950 22

Although previous work has demonstrated that biological phosphates ('biophosphates') record significant changes in delta18O associated with variations in local climate and seasonality, the repeatability of these analyses between laboratories has not previously been tested. We serially sampled enamel on four Cretaceous dinosaur teeth for phosphate delta18O analysis at up to three different facilities. With the exception of one set of unprocessed enamel samples, the material supplied to each laboratory was chemically processed to silver phosphate. Each laboratory analyzed sample sets by pyrolysis (thermochemical decomposition) in a ThermoFinnigan TC/EA attached to a ThermoFinnigan Delta Plus mass spectrometer. Significant interference between phosphate samples and the NIST reference material 8557 barium sulfate (NBS 127) distorts some of the results. Samples analyzed immediately following NBS 127 may be depleted by 6 per thousand isotopically and in instrument peak amplitude response by 80%. Substantial interference can persist over the subsequent 20 silver phosphate samples, and can influence the instrument peak amplitude response from some organic standards. Experiments using reagent-grade silver phosphate link these effects to divalent cations, particularly Ca2+ and Ba2+, which linger in the reactor and scavenge oxygen evolved from pyrolysis of subsequent samples. Unprocessed enamel includes 40 wt% calcium and self-scavenges oxygen, disrupting the isotopic measurements for the first half of a set and depleting subsequent organic standards by up to 9 per thousand. In sets without NBS 127 or calcium, such interference did not occur and an interlaboratory comparison of results from enamel shows reproducible, significantly correlated peaked delta18O patterns with a 2-3 per thousand dynamic range, consistent with previous results from contemporaneous teeth. Whereas both unprocessed enamel and the NBS 127 barium sulfate should be applied to biological phosphate ('biophosphate') stable isotope research with caution, seasonal variations in enamel phosphate delta18O are a paleoecologically valuable, reproducible phenomenon in theropod dinosaur teeth.
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PMID:Stable oxygen isotopes from theropod dinosaur tooth enamel: interlaboratory comparison of results and analytical interference by reference standards. 1551 30

Attenuated tissue culture-adapted and natural street rabies virus (RV) strains differ greatly in their neuroinvasiveness. To identify the elements responsible for the ability of an RV to enter the CNS from a peripheral site and to cause lethal neurological disease, we constructed a full-length cDNA clone of silver-haired bat-associated RV (SHBRV) strain 18 and exchanged the genes encoding RV proteins and genomic sequences of this highly neuroinvasive RV strain with those of a highly attenuated nonneuroinvasive RV vaccine strain (SN0). Analysis of the recombinant RV (SB0), which was recovered from SHBRV-18 cDNA, indicated that this RV is phenotypically indistinguishable from WT SHBRV-18. Characterization of the chimeric viruses revealed that in addition to the RV glycoprotein, which plays a predominant role in the ability of an RV to invade the CNS from a peripheral site, viral elements such as the trailer sequence, the RV polymerase, and the pseudogene contribute to RV neuroinvasiveness. Analyses also revealed that neuroinvasiveness of an RV correlates inversely with the time necessary for internalization of RV virions and with the capacity of the virus to grow in neuroblastoma cells.
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PMID:Identification of viral genomic elements responsible for rabies virus neuroinvasiveness. 1552 Mar 87

Xylanase of low molecular weight (K II) was isolated from the fungus Aspergillus niger IBT-90 cultivated in medium with wheat bran. K II was purified by precipitation with ammonium sulphate (20-80% saturation) and gel filtration on Biogel P-10. This enzyme is most active in hydrolysis of birchwood xylan at 50 degrees C and pH 5.5. Xylanase K II has an ability to degrade 1,4-beta-bonds and to debranch substrates. It degrades not only xylans but also cellulose, an important factor for its application in bakery. Ag+, Fe3+ and NBS are strong inhibitors of the enzyme. DTT and Na+ activate xylanase K II by 24 and 13%, respectively. Enzyme K II used as additive to flour improves dough properties, increases the volume of wheat-rye and whole meal bread, and increases the porosity of crumb and the moisture of the final product, consequently extending the shelf life of bread.
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PMID:Isolation and properties of Aspergillus niger IBT-90 xylanase for bakery. 1601 37

To probe the mitochondrial involvement in neurodegenerative processes, we have generated a high-resolution map of the mitochondrial proteome from a human neuroblastoma SH-SY5Y cell line that has been used for creating cytoplasmic hybrid cell systems. Two mitochondrial preparations were evaluated using two-dimensional (2D) gel electrophoresis and mass spectrometry; one obtained from differential centrifugation and the other by a multiple-step percoll/metrizamide gradient. The 2D gel maps prepared from these mitochondrial fractions separated over 300 distinct spots as visualized by colloidal Coomassie blue (CCB), or closer to 400 proteins with silver staining. The most abundant proteins identified in the mitochondrial fraction prepared by differential centrifugation were those of mitochondrial, cytoplasmic, and endoplasmic reticulum origin. Proteins obtained using the more intensive two-step gradient method were almost exclusively known to be associated with mitochondria. From this latter preparation, 84 of the most abundant gel spots were analyzed, out of which 61 proteins were identified. The absence of many membrane-associated proteins known to be associated with the mitochondrion and the limited number of total proteins observed in the 2D gel maps suggest that the majority of mitochondrial proteins are not being detected under these separation and staining conditions. An insoluble pellet obtained after solubilization of the mitochondrial fraction prepared with the percoll/metrizamide gradient was boiled in sodium dodecylsulfate (SDS) and separated by 1D sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE). This separation yielded some additional proteins, many of which are likely membrane-associated. These studies form the basis for the analysis of differential protein expression in cybrid cellular models of neurodegenerative disorders and in affected tissue from diseased states.
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PMID:Two-dimensional electrophoresis and mass spectrometric identification of mitochondrial proteins from an SH-SY5Y neuroblastoma cell line. 1612 Feb 76

Recent advances in MALDI MS/MS instrumentation allow a high degree of automation in the efficient detection of peptide fragment ions that can be used for protein identification. However, the performance of the technique is dependent on the MALDI sample preparation. We present a simple and robust two-layer sample preparation method tailored for sensitive and reproducible generation of MALDI MS/MS data. This method produces a strong and uniform crystal layer which allows acquisition of high quality MS/MS spectra over the entire sample surface area. Furthermore, due to its crystal strength, the matrix/sample layer can be washed extensively on target, enabling direct analysis of samples containing impurities, such as salts and surfactants. This method is demonstrated to be very useful in routine analysis of in-gel tryptic digests of silver-stained protein gel spots, without the need of desalting steps or hunting for "hot" spots. As an example, seven threonine-phosphorylated proteins involved in signal transduction in response to growth factor stimulation within the lipid raft fractions of the IMR5 neuroblastoma cells have been identified using differential gel display, in-gel digestion and MALDI MS/MS with the new two-layer sample preparation method. Some of these proteins have the functions of maintaining raft structure or cell signaling.
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PMID:Simple and robust two-layer matrix/sample preparation method for MALDI MS/MS analysis of peptides. 1621 24

An expedient synthesis of enantiomerically pure threo-beta-hydroxy-alpha-amino acid derivatives of phenylalanine, tyrosine, histidine, and tryptophan is described. The NBS-mediated radical bromination of the N,N-di-tert-butoxycarbonyl protected alpha-amino acids and subsequent treatment with silver nitrate in acetone provided the trans-oxazolidinones predominantly. Cesium carbonate catalyzed hydrolysis then generated the beta-hydroxy amino acid derivatives in excellent overall yield.
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PMID:Expedient synthesis of threo-beta-hydroxy-alpha-amino acid derivatives: phenylalanine, tyrosine, histidine, and tryptophan. 1693 77

The effects of steroid compounds from Pacific Ocean starfishes were studied using cultured neuroblastoma C-1300 cells. Vital observations and examination of silver-impregnated preparations showed that the test substances in a concentration of 2-10 microM stimulate differentiation and improves survival of neuroblastoma cells under adverse conditions (similarly to neurotrophins). These substances in high concentrations (20-40 microM) had no effect or exhibited cytotoxic activity. The screening test allowed us to select several compounds for further studies of neurotrophic and neuroprotective properties.
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PMID:Neurotrophic effects of polyhydroxylated steroids and steroid glycosides in cultured neuroblastoma cells. 1718 Oct 59

In the present study, an ultrahigh-resolution system was applied as a simple and convenient technique to characterize the extent of metal nanoparticle agglomeration in solution and to visualize nanoparticle agglomeration, uptake, and surface interaction in three cell phenotypes under normal culture conditions. The experimental results demonstrated that silver (25, 80, 130 nm); aluminum (80 nm); and manganese (40 nm) particles and agglomerates were effectively internalized by rat liver cells (BRL 3A), rat alveolar macrophages (MACs), and rat neuroendocrine cells (PC-12). Individual and agglomerated nanoparticles were observed within the cells and agglomerates were observed on the cell surface membranes. The particles were initially dispersed in aqueous or physiological balanced salt solutions and agglomeration was observed using the Ultra Resolution Imaging (URI) system. Different methods, such as sonication and addition of surfactant (0.1% sodium dodecyl sulfate [SDS]) reduced agglomeration. Due to effects of SDS itself on cell viability, the surfactant could not be directly applied during cell exposure. Therefore, following addition of 0.1% SDS, the particles were washed twice with ultrapure water, which reduced agglomeration even further. Reducing the agglomeration of the nanoparticles is important for studying their uptake and in applications that benefit from individual nanoparticles such as diagnostics. In summary, this study demonstrates a simple technique to characterize the extent of nanoparticle agglomeration in solution and visualize nanoparticle (40 nm and larger) uptake and interaction with cells. Additionally, an example application of nanoparticle labeling onto the surface and neurite extensions of murine neuroblastoma cells (N2A) is presented as a potential imaging tool.
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PMID:Assessment of metal nanoparticle agglomeration, uptake, and interaction using high-illuminating system. 1745 53


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