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Query: UMLS:C0027819 (neuroblastoma)
 27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of chlorhexidine digluconate preadded to urine samples for a neuroblastoma-screening test in preventing the break-down of creatinine (Cre), vanillylmandelic acid (VMA), and homovanillic acid (HVA) by creatinine-cleaving bacteria and the influence of the added disinfectant on the HPLC determination of urinary Cre, VMA, vanillillactic acid (VLA) and HVA. Laboratory or field experiments showed that preadded disinfectant (0.02% volume) nearly completely inhibited the growth of the bacteria and satisfactorily protected urinary Cre, VMA, and HVA from bacterial decomposition. Chlorhexidine digluconate was comparable to benzalkonium chloride in its inhibitory effects on the growth and activities of creatinine-cleaving bacteria. Unlike benzalkonium chloride, chlorhexidine digluconate added to urine samples gave no troubles in subsequent analytical processes. Addition of the disinfectant (0.02% volume) to standard Cre, VMA, VLA, and HVA solution did not affect retention times and sensitivities in HPLC analyses. To estimate influences of the added disinfectant on the serial HPLC determinations of VMA, VLA, and HVA on a large number of urine samples (40, 80, 120, 160, 200, or 5, 500), HPLC analyses were performed on standard VMA, VLA, and HVA solution with repeated injection of the disinfectant in great amounts into a column. The results showed no appreciable changes in the retention times and sensitivities of VMA, VLA, and HVA, and almost complete elution of the disinfectant retained on the column were possible with water-methanol (1:1, 2:8) or methanol washing.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Bacterial contamination of infant urine samples obtained from filter papers used in neuroblastoma-screening tests. (6) Protective effects of preaddition of chlorhexidine digluconate in filter papers or containers for urine on bacterial break-down of creatinine, vanillylmandelic acid and homovanillic acid]. 146 45

Recent studies indicate that ethanol (EtOH) potentiates ion current through the channel associated with the 5-hydroxytryptamine3 (5-HT3)-type serotonin receptor. The present study was designed to determine 1) whether such potentiation occurs in adult mammalian neurons expressing 5-HT3 receptors; 2) whether potentiation is selective for the 5-HT3 receptor, relative to other ligand-gated ion channels; and 3) possible mechanisms by which EtOH potentiates this response. EtOH potentiated 5-HT3 receptor-mediated ion current in freshly isolated nodose ganglion neurons at concentrations similar to those previously reported to be effective in neuroblastoma cells (25-100 mM). Current was blocked by the selective 5-HT3 antagonist ICS 205-930 even in the presence of EtOH, and current activated by a 5-HT3 agonist (2-methyl-5-HT) was potentiated by EtOH. Thus, EtOH appears to produce potentiation via an alteration in the function of 5-HT3 receptors and not through an independent effect. gamma-Aminobutyric acidA receptor-mediated Cl- current was not potentiated by EtOH in neurons in which potentiation of responses to 5-HT was observed. Methanol potentiated 5-HT3 receptor-mediated current with a potency lower than that of EtOH. Potentiation by EtOH decreased with increasing 5-HT concentration. In addition, EtOH increased the decay rate of current. EtOH did not alter the reversal potential of the 5-HT3 receptor-mediated current. These observations indicate that intoxicating concentrations of EtOH selectively potentiate 5-HT3 receptor-mediated responses by increasing the apparent potency of 5-HT for activating ion current.
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PMID:Ethanol potentiation of 5-hydroxytryptamine3 receptor-mediated ion current in neuroblastoma cells and isolated adult mammalian neurons. 171 16

In this study, hepatic microsomes from 5,6-benzoflavone induced C57BL/10 mice were used. To inhibit monooxygenase activities, the monoclonal antibody MAb 1-7-1 recognizing two isoenzymes of methylcholanthrene-induced cytochrome P-450 was applied. Microsomes were incubated with tritium labeled benzo(a)pyrene [G-3H]BP for 10 min at 37 degrees C. The incubation mixture contained: 50 mM potassium phosphate buffer, pH 7.25; 30 mM KCl; 3 mM MgCl2; 2 mM NADPH; 80 microM [G-3H]BP (specific activity 50 mCi/mmol); and monoclonal antibody MAb 1-7-1 or ascites fluid (NBS) containing nonspecific IgG as a control. The ratio of antibody protein/microsomal protein was 2:5. BP metabolites were extracted from incubation mixtures by ethyl acetate. The organic layer was dried over sodium sulfate, and evaporated under a stream of nitrogen. To separate BP metabolites HPLC technology was used. The column was eluted with methanol gradient (60-100%) for 45 minutes. The radio-activity of collected samples was determined using liquid scintillation counter. Differential inhibitory effects of MAb 1-7-1 on BP-metabolites formation were found, e.g. 7,8-diol was inhibited by 86.1% and quinones by 62.5%. The predominant metabolite, 3-OH-BP, was inhibited by 80.4%. Moreover, it was found that MAb 1-7-1 inhibition of benzo(a)pyrene hydroxylase activity (by 75.8%, as measured by fluorescent technique) was very similar to the inhibition of 3-OH-BP along with 9-OH-BP formation (as measured by HPLC).
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PMID:[Effect of monoclonal antibody against methylcholanthrene-induced cytochrome P-450 forms on benzo(a)pyrene metabolism in hepatic microsomes of C57BL/10 mice]. 209 79

The sensitivity and selectivity of high-resolution gas chromatography/mass spectrometry in the negative ion chemical ionization mode with methane as reagent gas was evaluated for the characterization of polar substituted polycyclic aromatic compounds (PAC). The fragmentation patterns were affected by the nature of the substituent for polar substituted nitro-PAC that showed detection limits of 50 pg at full-scan acquisition. This technique has been applied to the characterization of polar high-performance liquid chromatographic fractions of diesel exhaust particulate (NBS Standard Reference Material 1650) and enabled the identification of 20 PAC of different chemical classes. Among them, hydroxynitro-, dinitro- and nitrosubstituted secondary amines were identified for the first time in diesel exhaust particulate. In addition, 'filament-on' thermospray (TSP) liquid chromatography/mass spectrometry (LC/MS) with positive and negative ions have been used for the characterization of similar polar compounds such as 2-nitroquinoline, 1,8-naphthalic anhydride, naphthalene sulphonic acid and 1,2-hydroxynitronaphthalene. LC analyses were performed on a reversed-phase system using either acetonitrile-water or methanol-water with 0.1 M ammonium acetate and 1% acetic acid as eluent. With negative ion TSP LC/MS a four- to fivefold loss in sensitivity was observed for naphthalene sulphonic acid compared with nitrohydroxy-PAC, that showed a minimum detectable amount of 50 ng in the reconstructed ion chromatogram.
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PMID:Characterization of polar substituted polycyclic aromatic compounds using high-resolution gas chromatography/mass spectrometry negative ion chemical ionization and positive and negative ion thermospray liquid chromatography/mass spectrometry. 246 74

A tissue culture virus isolation procedure for rabies street strain virus on mouse neuroblastoma cells is described. Parameters for the optimum sensitivity of the procedure were determined to include a minimum 4-day incubation of virus in tissue culture and the use of diethylaminoethyl-dextran for increased cell susceptibility. The in vitro procedure performed well in a comparison with the fluorescent-antibody test and the mouse inoculation test (MIT) on weakly positive brain tissue. Decomposed specimens and virus inhibitors present in brain suspensions were found to interfere with the in vitro procedure. A Formalin-methanol fixative was found to be superior on plastic 96-well plates to previously used fixatives. A 2-year clinical trial of the procedure in parallel with the MIT demonstrated the practicality of the procedure. Accordingly, the New York State rabies diagnostic laboratory has replaced the MIT with the in vitro procedure as a backup for the fluorescent-antibody test in the routine diagnosis of rabies.
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PMID:Development and evaluation of an in vitro virus isolation procedure as a replacement for the mouse inoculation test in rabies diagnosis. 268 Dec 54

The content and concentration of fatty acids lightly and tightly bound with proteins and the concentration of cholesterol were studied in differentiated and undifferentiated neuroblastoma C1300 N18 cells. Lightly bound lipids were extracted by the method of Blight and Dyer with subsequent additional rinsing by chloroform-methanol (1:1) and methanol extractions. The remaining protein-bound lipid was cleaved by mild alkaline hydrolysis in the methanol medium. Methyl esters of fatty acid were the fraction tightly bound with proteins. The main components in the fractions were fatty acids 16:0, 18:0, 18:1 omega 9, 20:4 omega 6. Cell differentiation caused changes essential in the content and concentration of fatty acids in the both fractions: the total quantity of saturated fatty acids was found to increase, the relative level of saturated fatty acids was higher in the tightly bound lipid fraction. During cell differentiation the level of cholesterol increased per 1 mg of protein in the lightly bound lipid fraction. In the tightly bound lipid fraction the cholesterol level per 1 mg of protein was unchanged.
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PMID:[Content of fatty acids bound to proteins and of cholesterol in neuroblastoma C1300 N18 cells during differentiation]. 274 16

A method for determining serum catecholamine metabolites such as vanillylmandelic acid (VMA), 3-methoxy-4-hydroxyphenyl glycol (MHPG) and homovanillic acid (HVA) in neuroblastoma by using high performance liquid chromatography and electrochemical detector is described. The separation of catecholamine metabolites was performed on a reverse phase column with an eluting system containing citric acid-potassium hydrogen phosphate buffer and methanol as the organic modifier. The experimental results showed that VMA and HVA levels in the serum of neuroblastoma patients were 15-30 times higher than that of the normal control group. The same phenomenon also occurred in patients with stage II neuroblastoma. Serum VMA, MHPG and HVA levels reduced to normal in patients suffering from neuroblastoma after surgery. Serum catecholamine metabolites analysed by using HPLC/ECD is more simple, sensitive and reliable than that by usual urine assay and might be used for the diagnosis of neuroblastoma even in early stage.
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PMID:Determination of serum catecholamine metabolites in neuroblastoma by high performance liquid chromatography with electrochemical detection. 350 18

N-Acetylneuraminic acid (Neu5Ac) and [6-2H]-Neu5Ac were prepared from 2-acetamido-2-deoxy-D-glucose (N-acetyl-D-glucosamine). Then Henry reaction of a 1-deoxy-1-nitro derivative of GlcNAc (protected 1-C-nitroanhydro-D-glucitol) with cyclohexylidene-D-glyceraldehyde, followed by successive acetylation and reductive denitration with Bu3SnH, gave an anhydrononitol intermediate (6) diastereo-selectively in high yields. Debenzylidenation of 6 freed its distal primary carbinol group, which was subjected to catalytic oxidation followed by hydrolysis, esterification (diazomethane), and acetylation to give a protected methyl nononate. This ester was transformed into the known methyl N-acetyl-4,7,8,9-tetra-O-acetyl-2,3-dehydroneuraminate (15), which was identical with a sample prepared from Neu5Ac. Neu5Ac was obtained from 15 by bromoetherification (NBS, methanol) followed by reductive debromination with Bu3SnH and hydrolysis. Similarly, the [6-2H]-derivative of 15 was transformed into [6-2H]-Neu5Ac.
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PMID:A synthesis of N-acetylneuraminic acid and [6-2H]-N-acetylneuraminic acid from N-acetyl-D-glucosamine. 362 Dec 40

A method for the determination of selenium in human spermatozoa and prostasomes is described. The samples were digested with 25% (w/v) tetramethylammonium hydroxide (TMAH) in methanol and analyzed by atomic absorption spectrometry with electrothermal atomization and Zeeman background correction (ET-AAS). Nickel was used as a matrix modifier. Calibration was performed using the matrix-based calibration curve. The TMAH-digestion method agreed well with a conventional digestion procedure using concentrated nitric acid. The TMAH-digestion does not require heating or strong acids and it was suitable for small biological samples. The average recovery of added selenium in spermatozoan digests was 95.1 +/- 5.2% (n = 5). The coefficient of variation was 9.1% (n = 21). The accuracy of the method tested with the NBS standard 1577 (bovine liver, certified at 1.1 +/- 0.1 micrograms Se/g) resulted in a value of 0.98 +/- 0.10 micrograms Se/g (n = 16). The method was further tested in an interlaboratory comparison study.
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PMID:Determination of selenium in human spermatozoa and prostasomes using base digestion and electrothermal atomic absorption spectrophotometry. 367 30

In the mixed culture system nontransformed 3T3 fibroblasts cells inhibited the plating efficiency of neuroblastoma (N2a) cells, whereas heat or methanol killed fibroblasts did not. In contrast, chloroform/methanol extracted 3T3 cells inhibited the plating efficiency of neuroblastoma cells to the same extent as had been the case with living 3T3 cells. In the present study, we discuss the possibility that nontransformed cells surface components can modify the proliferation of neuroblastoma cells.
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PMID:Mouse neuroblastoma cloning efficiency modulation by quiescent 3T3 cells in culture. 395 32


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