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Biomedical subjects

N Nose

Publications and source records attributed to N Nose.

28 records · Page 2Linked to original sources
PubMed1981

Determination of nitrite in human, cow and market milks by gas-liquid chromatography with electron-capture detection.

A simple and practical method for the determination of very small amounts of nitrite in human, cow and market milks is described. It is based on the reaction of nitrate with 1-hydrazinophthalazine in acidic solution to form tetrazolophthalazine, a stable compound which can be extracted with an organic solvent and then determined by gas-liquid chromatography with electron-capture detection using a column of 3% OV-225 on Chromosorb W HP; the detection limit for nitrite was 2 ng/ml. The procedure for determining nitrite in milks involves extraction with solvent, followed by further clean-up by alumina column chromatography; the detection limit is about 4 ppb and recovery in human, cow and market milks was satisfactory. The method makes possible a micro-assay for nitrite. The tetrazolophthalazine was identified by its elemental composition, melting point and by combined gas chromatography-mass spectrometry.

Animals↗
PubMed1980

Gas chromatographic determination of nitrite in foods as trimethylsilyl derivative of 1H-benzotriazole.

1,2-Diaminobenzene reacts with nitrite in acidic solution to form 1H-benzotriazole, which can be extracted into ethyl acetate. After evaporation of the ethyl acetate, 1H-benzotriazole is determined as its trimethylsilyl derivative by gas--liquid chromatography on a column of 15% SE-30 on chromosorb G HP at 200 degrees C with flame-ionization detection. The nitrite concentration is calculated from the peak height. Amounts of 0.5--10 microgram of nitrite-nitrogen can be determined. For the determintion of nitrite in foods, clean-up of the crude extracts by ion-exchange column chromatography allows the satisfactory elimination of interferents and permits concentrations down to 0.41 ppm to be determined. The recovery of the nitrite added to foods at the 4.1 ppm level ranges from 94.6 to 98.7% and at the 8.2 ppm level it ranges from 95.2 to 98.8%. The trimethylsilyl derivative of 1H-benzotriazole was identified as 1-trimethylsilylbenzotriazole by combined gas chromatographic--mass spectrometric examination and nuclear magnetic resonance spectrometry.

Food Analysis↗
PubMed1976

Gas-liquid chromatographic determination of sulphonamides.

Simultaneous qualitative analysis of fourteen sulpha drugs and their individual quantitative determinations have been performed by gas-liquid chromatography on solutions of dimethylformamide dialkylacetal derivatives of the drugs in acetone. Linear calibration curves were obtained for each sulpha drug under appropriate conditions. The structures of the above derivatives are assumed to be N1-methyl, N4-acetal sulphonamides, which can be detected with an electron capture detector with highly sensitive response. Columns used were 10% OV-101, 5% XE-60 and 5% OV-225.

Acetals↗
PubMedDate not supplied

Evaluations of p53 immunoreactivity, nucleolar organizer regions, and proliferating cell nuclear antigen in non-small cell lung carcinoma.

We examined p53 protein expression, proliferating cell nuclear antigen (PCNA), and argyrophilic nuclear organizer regions (AgNOR), in 102 patients with surgically-treated non-small cell lung cancer (NSCLC). p53 positive cases with DO-1 were defined when more than 10% of the tumor cell nuclei were stained. Mean AgNOR count and PCNA LI were 2.80 and 40.7 and there were no significant differences of AgNOR count and PCNA LI between p53 positive and negative cases. We assessed the relationship between the p53 immunoreactivity and various clinical or pathological parameters. p53 positive rate of stage III disease (46.3%) was significantly higher than that of stage II disease (28.6%). The p53 positive rate of squamous cell carcinoma (42.1%) tended to be higher than that of adenocarcinoma (33.9%). In the survival curves of patients with NSCLC according to the p53 immunoreactivity, there was no significant difference between p53 positive and negative cases. Eight potential prognostic parameters (p53 immunoreactivity, AgNOR count, PCNA LI, sex, age, year of operation, histology, and stage) were also estimated, using univariate and multivariate analysis. In univariate analysis, PCNA LI and AgNOR count, and stage were significantly related to shortened survival. In multivariate analysis, PCNA LI, Age, and stage were independently associated with shortened survival of NSCLC patients. PCNA staining may be more useful than p53 and AgNOR staining in assessing the aggressiveness of surgically-treated NSCLC, although the most useful clinical prognostic parameter should be achieved by the combined analysis of several prognostic indicators.

Adult↗
PubMedDate not supplied

Simultaneous liquid chromatographic determination of residual synthetic antibacterials in cultured fish.

A liquid chromatographic method is described to determine simultaneously the following 11 synthetic antibacterial agents used in a fishery: nitrofuran derivatives furazolidone, nifurpirinol, difurazone, and furamizole; sulfa drugs sulfamerazine, sulfisozole, sulfamonomethoxine, and sulfadimethoxine; and, oxolinic, nalidixic, and piromidic acids. A Nucleosil C18 column was used with tetrahydrofuran-acetonitrile-phosphoric acid-water (29 + 1 + 0.06 + 69.94) as the mobile phase. Pretreatment of the fish meat sample with acetone extraction and alumina column cleanup gave good separation of the LC peaks without interference from any other components. Recovery of the antibacterial agents was ca 80%. The lower limit of detection of the drugs was 1-2 ng for 10 microL injection.

Animals↗