PubMed Health⌕ Search

Biomedical subjects

M L Bastos

Publications and source records attributed to M L Bastos.

45 records · Page 3Linked to original sources
PubMedDate not supplied

Glutathione and cysteine measurement in biological samples by HPLC with a glassy carbon working detector.

An HPLC method using a glassy carbon working detector for measuring cysteine and reduced glutathione (GSH) in biological samples was developed. Oxidized glutathione (GSSG) was also measured after reduction with glutathione reductase. This study was conducted in human plasma. Cysteine and GSH standard curves were linear in the physiological range, presenting detection limits of 22.0 pmol and 6.0 pmol respectively. Plasmatic results found were 43.92 +/- 4.15, 4.50 +/- 0.65, and 0.19 +/- 0.12 mM (means +/- SE), for cysteine, GSH and GSSG, respectively. Peak specificity for cysteine and reduced glutathione was certified by their disappearance after treatment with N-ethylmaleimide.

Adult↗
PubMedDate not supplied

Evaluation of ethanol analysis on brain and liver by head-space gas chromatography.

An evaluation of the reliability of ethanol analysis in brain by the head-space gas chromatographic method has shown the following. (a) This method may be used directly, without prior distillation, with homogenized brain tissue; (b) a good correlation exists with values obtained on blood (blood/brain ratio of 0.97 and 1.32 for blood ethanol concentrations of 0.1 and 0.2 g/dl respectively); (c) in non-preserved blood, there is a 15% deviance in the correlation resulting from changes in ethanol concentration; (d) the same evaluation applied to ethanol analysis in liver reveals a poor correlation between the results in liver and blood; this is believed to result mainly from natural oxidative losses of ethanol in liver, and also from the variable fat content of the liver samples analyzed. Caution is emphasized with regard to interpretations of blood/brain and blood/liver ethanol concentration ratios for the purpose of determining pre- and post absorption stages of intoxication where samples involved are not properly preserved.

Analysis of Variance↗
PubMedDate not supplied

The study of oxidative stress in freshly isolated Ca(2+)-tolerant cardiomyocytes from the adult rat.

Cardiotoxicity studies using isolated heart cells are becoming increasingly advocated as a supplement to, and sometimes as a replacement for, whole heart or whole animal experimentation. In fact, the use of isolated cardiomyocytes has the great advantage of enabling mechanistic and comparative studies of compounds, which are directly toxic to cardiomyocytes. Since the 1970s, different procedures have been developed in order to obtain Ca(2+)-tolerant cardiomyocytes. The advances in this field will be reviewed and an optimised method to obtain freshly isolated Ca(2+)-tolerant cardiomyocytes from the adult rat for use in toxicological studies will be described. With this procedure, a high number of rod-shaped cells can be obtained (6-7 x 10(6)/heart corresponding to 70% of total number of cells). It is also possible to maintain cell viability, glutathione content and enzymatic activity of glutathione reductase (GR), glutathione peroxidase (GPX) and glutathione S-transferase (GST) in acceptable levels for 4 hours. Cardiotoxicity studies performed with isoproterenol (ISO) in the presence of copper and with the model toxic substance tert-butylhydroperoxide (t-BHP) demonstrate the importance of oxidative stress as a cardiotoxic mechanism elicited by these molecules. The results obtained are also good indicators for future applications of this methodology to other cardiotoxicity studies.

Animals↗
PubMedDate not supplied

Improved detection and identification of basic drugs extracted from tissue using TLC.

Improved separation of methaqualone, lidocaine, cocaine, phencyclidine, phenacetin and methadone was achieved by a double development technique using dichloromethane:methyl ethyl ketone:ammonia (90:10:1.5 and 30:70:2). Improved identification of spots for some basic drugs was achieved after the traditional detection spray sequence with successive topical applications of: Marquis reagent, Mandelin reagent and a special ammonium molybdate fuming sulfuric acid reagent.

Chromatography, Thin Layer↗
PubMedDate not supplied

[The trajectory of the Brazilian Nurses Association-Alagoas].

This article outlines the trajectory of the Brazilian Association of Nursing (ABEn) in Alagoas and its influence in the organization of the nursing profession in this federal state. It points out that ABEn-AL was the first institution to organize nursing in Alagoas, since it was founded prior to any nursing graduation course or even any nursing syndicate. Therefore, ABEn is considered a decisive landmark in the political and professional organization of nursing in the state of Alagoas.

Brazil↗
PubMedDate not supplied

Selective determination of chromium (VI) in powdered milk infant formulas by electrothermal atomization atomic absorption spectrometry after ion exchange.

A previously developed method was adapted to the selective determination of hexavalent chromium in powdered milk infant formulas. The species in reconstituted milk was separated on an ion-exchange column, Chromabond NH2, and measured by electrothermal atomization atomic absorption spectrometry. The detection limit was 1.8 micrograms/L, and the linearity range under optimized conditions was 1.8-50.0 micrograms/L. The precision values were 4.1 and 6.5% for the analytical and overall procedures, respectively. The procedure was validated by the method of standard additions (5.0, 10.0, and 25.0 micrograms/L), and the recoveries were all > 93%. The developed method is sensitive, accurate, and precise for determination of Cr(VI) in powdered milks. It was applied to the determination of Cr(VI) in 20 commercial brands, i.e., 7 infant formulas, 5 follow-up milks, and 8 dietetic milks. The values found ranged from < 10 to 75 ng/g.

Chromatography, Ion Exchange↗