Biomedical subjects

B S De Martinis

Publications and source records attributed to B S De Martinis.

4 recordsLinked to original sources

PubMed2006

Alcohol distribution in different postmortem body fluids.

AIMS: The determination of postmortem ethanol is one of the most frequently requested analyses in forensic toxicology and of extreme importance, especially when the concentration is found to be above the legal level for intoxication at one sampling site and below that level at another sampling site. Because of the unavailability of blood samples for toxicological analysis or even contaminated samples, there is an enormous effort to find alternative sampling sites, such as vitreous humor for ethanol analysis. The main purpose of this study was to establish correlations between urine and blood alcohol concentrations collected from different sites and vitreous humor. METHODS: Ethanol concentrations were determined in specimens of heart, subclavian and femoral blood, urine and vitreous humor, collected from 21 cadavers who were victims of different causes of death. Determinations of ethanol were performed in duplicate using capillary gas chromatography/flame ionization detector and headspace techniques. RESULTS: Statistical analysis of the results indicated that there were no significant differences among urine and blood samples collected from different sites compared to vitreous humor. Regarding vitreous humor ethanol concentration, Pearson's correlation coefficient was 0.97 for femoral blood and urine, 0.96 for heart blood and 0.94 for subclavian blood. The results demonstrated that all the fluids tested against vitreous humor significantly correlated with P (associated probability for the used correlation tests) <0.05. CONCLUSIONS: Vitreous humor can be considered as an alternative sample to urine and blood specimens.

Body Fluids↗

PubMed2001

Effect of vitamin C supplementation against cisplatin-induced toxicity and oxidative DNA damage in rats.

Antitumor agents are used as a common therapy against some kinds of cancer. However, as with many agents that have mammalian cell toxicity as a target, physiological adverse effects can occur such as nephrotoxicity and genotoxicity that can be induced in non-tumor cells by generating activated oxygen species, which attack the DNA frequently resulting in oxidative DNA damage. To diminish the undesirable side-effects of therapy and to reduce the levels of oxidative DNA damage, it is recommended for patients to ingest food supplements and vitamins combinations containing substantial amounts of antioxidants. In the present study, we investigated the effects of cisplatin and vitamin C on the renal toxicity and on the oxidative DNA damage. Rats were co-treated with the chemotherapeutic agent cisplatin (5 mg kg(-1) body weight) and dietary doses of vitamin C (50 and 100 mg kg(-1) body weight). Results demonstrated that depending on the treatment protocol, we observed alterations in parameters such as body weight, urinary volume and urinary creatinine, indicating some kidney toxicity. We also observed changes in the urinary levels of 8-OHdG, suggesting possible oxidative DNA damage.

8-Hydroxy-2'-Deoxyguanosine↗

PubMed2000

An alternative supercritical fluid extraction system for aqueous matrices and its application in pesticides residue analysis.

Supercritical fluid extraction (SFE) is a rapid and convenient method for the isolation of organic compounds from environmental samples. This paper describes a supercritical carbon dioxide (CO2) extraction system that uses a newly designed extraction cell to recover organic compounds from an aqueous matrix. Analysis of the extracts by gas chromatography-electron capture detector (GC-ECD) indicated that the herbicide trifluralin (2,6-dinitro-N,N-dipropyl-4-trifluoromethylaniline) could be quantitatively extracted by using the SFE system proposed with small amounts of sample. The percentage of recovery obtained with the SFE system described was twice as high as the result obtained using a conventional solid-phase extraction technique. Extraction by SFE was completed in a short period of time using a simple and low-cost home-made system that did not require the use of organic solvents.

Calibration↗

PubMed1999

Genotoxicity of fractionated organic material in airborne particles from São Paulo, Brazil.

Particulate matter less than 10 microns aerodynamic diameter (PM10) is associated with adverse health effects including increased respiratory problems and mortality. PM10 is also associated with increases in cancer in some urban areas. Identification of toxic compounds in PM10 is a step toward estimating exposure to these compounds and evaluating their public health risk. However, the toxic compounds on PM10 are part of a highly complex mixture of compounds that makes chemical characterization difficult. Before this study, there has been little investigation of genotoxic compounds in particulate matter from Latin American cities. Here, both bioassay (mutagenicity) and chemical analyses were conducted with organic solvent extracts of PM10 collected from São Paulo, a major Brazilian city. Sequential extraction in dichloromethane (DCM) followed by acetone (ACE) yielded 20.3% and 10.2% of the total mass, respectively. Non-polar and moderately polar organic material solubilized in DCM. ACE extracted more polar organic species and some inorganic ions. Both extracts were fractionated separately using cyanopropyl-bonded silica chromatography with organic solvents of increasing polarity. The mass distribution among the fractions was measured. The mutagenic activity of the fractions was assayed using the microsuspension procedure with the Salmonella typhimurium tester strain TA98, with and without addition of metabolic enzymes (S9). The DCM extract had about four times higher mutagenic activity than the ACE extract. In general, addition of S9 resulted in an increase in mutagenicity of DCM fractions, but a decrease for the ACE extract. Most of the activity was concentrated in fractions in the mid-range of polarity within both the DCM and ACE extracts. The fractions were analyzed by gas chromatography with mass selective detection (GC/MS) without derivatization. The most mutagenic fractions in the DCM extract contained ketones, aldehydes, and quinolines. The most mutagenic ACE fraction had ketones, carboxylic acids, and aldehydes.

Air Pollutants↗