The possibilities of hair analysis in the determination of involuntary doping in sports.

Although not yet fully recognised by international sporting committees, hair analysis in doping control may be a useful adjunct to drug testing of urine. It may permit access to retrospective information and the identification of banned substances, especially when exogenous abuse has to be distinguished from other forms of involuntary exposure to identical substances. Negative hair results coupled with positive urine samples may be used to draw conclusions of involuntary doping in sports whenever athletes claim not to have ingested any drug, identical substances are present in their environment or are normal constituents of food and beverages served to them immediately before the competition. Two cases are well described in the literature in which hair analyses were fundamental in documenting positive doping after urinalysis. In Brazil, 2 cases of athletes testing positive for banned substances caught our attention because of the possibility of involuntary doping; hair analysis, if performed, may have helped to clarify the results of the urinalysis. Despite the fact that it cannot be used for routine control and overrule positive urinalysis, hair analysis can detect long term exposure as well as those substances which are not excreted in urine. In the current International Olympic Committee (IOC) code, hair analysis is not yet considered useful even in special cases of doping control.

Occurrence of aflatoxins B1, B2, G1 and G2 in cooked food components of whole meals marketed in fast food outlets of the city of São Paulo, SP, Brazil.

Samples of cooked components of regular meals served at fast food outlets of the city of São Paulo, Brazil were analysed for aflatoxins B1, B2, G1 and G2. The 322 samples were composed of prepared traditional Brazilian and ethnic foods in which aflatoxins might be present. Thin-layer chromatography was used for separation of the compounds and their determination was achieved by both long wave UV light and fluorodensitometry. Aflatoxins were detected in 30 samples (9.31% of the total) in a range of 2.80 to 1323 ng/g for B1 + B2 + G1 + G2 with 90th percentiles of 158 (B1 + G1) and 258 (B1 + B2 + G1 + G2). Aflatoxin B1 was detected in all contaminated samples. The contamination levels and frequency of aflatoxins B1 and G1 in positive samples above 20 ng/g in this study are high, indicating that there is a certain degree of exposure of the population to the carcinogenic aflatoxin.

Drug monitoring of quinine in men with nonsevere falciparum malaria: study in the Amazon region of Brazil.

Quinine sulfate has been the drug of choice for the treatment of the ever-increasing number of cases of falciparum malaria in tropical countries. Because of the spectrum of adverse effects produced by the drug in the so-called cinchona syndrome, the variation in its pharmacokinetics during the episodes of falciparum malaria, and the different therapeutic regimens proposed in different countries, the authors monitored quinine plasma concentrations in daily samples of 20 men of the Amazon region in Brazil with nonsevere falciparum malaria who were administered 1 g quinine sulfate every 12 hours for 7 days. Three blood samples were collected from each patient each day: two immediately before administration of the drug (7 am and 7 pm) and one at 11 am. A total of 440 samples were analyzed by a validated method developed in the authors' laboratories using the high-performance liquid chromatographic technique. The overall quinine plasma levels obtained varied from 1.52 to 16.89 microg/mL. From the second day of treatment, overall levels varied from 2.33 to 14.29 microg/mL; the peak concentrations showed values from 4.22 to 16.89 microg/mL, showing the efficacy of the therapeutic regimen used. Adverse effects (signs and symptoms of cinchonism) were observed in all patients. However, no cases of hypoglycemia were detected. Intrapatient comparisons of the obtained quinine plasma concentrations were statistically significant. The quinine dose may be reduced on day 4 of treatment when asexual parasitemia is absent. This way, no resistance to the drug is observed, cinchonism can be minimized, and good adherence to the regimen is obtained.

Validated high-performance liquid chromatographic method for the determination of lamotrigine in human plasma.

A high-performance liquid chromatographic (HPLC) procedure for lamotrigine was developed and validated. Lamotrigine (LTG) and an internal standard were extracted from plasma using liquid-liquid extraction under alkaline conditions into an organic solvent. The method was linear in the range 0.78-46.95 micromol/l, with a mean coefficient of correlation (r)> or =0.99923. The limit of detection (LOD) and limit of quantification (LOQ) were 0.19 and 0.58 micromol/l, respectively. Within- and between-run precision studies demonstrated C.V.<3% at all tested concentrations. LTG median recovery was 86.14%. Antiepileptic drugs tested did not interfere with the assay. The method showed to be appropriate for monitoring LTG in plasma samples.

Validation of an ion-trap gas chromatographic-mass spectrometric method for the determination of cocaine and metabolites and cocaethylene in post mortem whole blood.

The coingestion of cocaine (COC) and ethanol is a very frequent occurrence and is known to increase the risk of morbidity and mortality. The formation occurs of a transesterification product, the cocaethylene (CE), which is even more toxic than cocaine. In order to study the role of ethanol as an agent of interaction in lethal cocaine intoxication, and to establish its influence in post mortem cocaine concentrations, an ion-trap gas chromatographic-mass spectrometric method (GC-MS) was validated to quantify simultaneously the agent and its biotransformation products, benzoylecgonine (BE), ecgoninemethylester (EME) and the 'biomarker' of the interaction, the CE present in whole blood. Deuterated internal standards were added to 2 ml of post mortem whole blood and extracted in Bond Elut Certify columns. The residues were evaporated and derivatized with N-methyl-N-t-butyldimethylsilyltrifluoroacetamide (MTBSTFA). Detection was performed by electron impact ionization. The monitored ions were m/z 82/85 for EME-tert-butyldimethylsilyl (TBDMS)/EME-d3-TBDMS; m/z 182/185 for COC/COC-d3; m/z 196/199 for CE/CE-d3 and m/z 282/285 for BE-TBDMS/BE-d3-TBDMS. The limits of detection and quantification were found to be 25 ng and 50 ng ml(-1), respectively, for COC and CE, and 50 and 100 ng ml(-1) for BE and EME. Accuracy was different for each of the compounds, varying from 65 to 98%. The dynamic range of the assay was 50-2000 ng ml(-1).

[Human exposure to trihalomethanes in drinking water]. / Exposição humana a trialometanos presentes em água tratada.

Halogenated hydrocarbon compounds, some of them recognized as carcinogenic to different animal species can be found in drinking water. Chloroform, bromodichloromethane, dibromochloromethane and bromoform are the most important trihalomethanes found in potable water. They are produced in natural waters during chlorinated desinfection by the halogenation of precursors, specially humic and fulvic compounds. The review, in the MEDLINE covers the period from 1974 to 1998, presents the general aspects of the formation of trihalomethanes, sources of human exposure and their toxicological meaning for exposed organisms: toxicokinetic disposition and spectrum of toxic effects (carcinogenic, mutagenic and teratogenic).

Origin of blood ethanol in decomposed bodies.

Problems related to blood contamination by other postmortem fluids in decomposed bodies (DB) make the interpretation of medicolegal blood alcohol levels (B EtOH) a very difficult task. So the aim of this paper is to show the utilization of vitreous humor (VH) as the biological fluid for an unequivocal determination of ethanol origin in DB for forensic purposes. Alcohol was determined in VH, blood (chest fluid-CF) and urine (Ur) collected from 27 DB in different states of putrefaction. A simple head-space gas-chromatographic method was used. In fifteen cases alcohol was found to be of endogenous production due to its absence in VH. In the twelve remainders, alcohol was detected in VH and CF in an atypical distribution. Examining the reliable scene and historical information together with the analytical data, ethanol origin in these cases was classified: endogenous production (3 cases), ingested (2 cases), both (2 cases), contaminated plus endogenous production (3 cases) and unable to determine (2 cases). According to the results obtained it was possible to conclude that alcohol analysis in VH is fundamental for determining the origin of ethanol detected in CF of DB.

A field method for the determination of whole blood cholinesterase.

Blood cholinesterase activity is an efficient indicator of exposure to organophosphate insecticides. Field methods, in spite of lacking sensitivity, are important when practical determinations and immediate results are necessary One of the mostly used field methods to assess blood cholinesterase activity is the Lovibond Cholinesterase Field Kit. This paper proposes to substitute the comparator disk of the Lovibond Field Kit with a set of standard solutions that exhibit similar colours. Dilutions of Bromothymol blue, whole blood and acetic acid in different concentrations were used to construct a set of coloured solutions which correspond to different degrees of ChE inhibition. The comparison of acetylcholinesterase activity measured with the two methods showed good agreement and satisfactory reproducibility of results. The use of a standard colored solution kit seems more suitable and manageable for field studies than the Lovibond comparator disk.

Cocaine-related problems in the city of São Paulo, 1982-1986.

From 1982 to 1986, there was an overall increase in the number and amount of illicit cocaine seized at São Paulo. There was a total of 1,552 seizures of illicit cocaine, which were confirmed by testing in the laboratory of the Technical Service of Forensic Toxicology, a section of the Medical-Legal Institute of São Paulo. The increase in cocaine seizures was accompanied by an increase in cocaine-related mortality. Although there were no cocaine-related deaths reported in the city before 1982, there was an increasing trend in the number of such deaths during the five-year period that followed.

Aspectos toxicologicos de inseticidas de uso domestico. / The toxicological aspects of domestic inseticides

A analise critica das varias formulacoes de inseticidas de uso domestico encontradas no mercado e apresentada do ponto de vista toxicologico. A descricao exata dos rotulos dos produtos comerciais mais significativos; as caracteristicas quimicas e propriedades fisico-quimicas de seus principios ativos, acrescidas do estudo toxocinetico e toxodinamico; a toxicidade dos solventes, propelentes e sinergistas, componentes dessas formulacoes, sao tambem referidos. A classificacao dos inseticidas, de acordo com os indices de toxicidade propostos pela Organizacao Mundial da Saude, bem como o estudo toxicologico dos citados produtos sao feitos a fim de que se possa alertar para o risco de acidentes toxicos aos quais o consumidor brasileiro esta exposto

Aspectos toxicologicos de hidrocarbonetos alifaticos clorados. / Toxicological aspects of chlorinated aliphatic hydrocarbons

Os autores apresentam um estudo de revisao sobre os aspectos toxicologicos de hidrocarbonetos alifaticos, clorados. As propriedades fisico-quimicas, o uso industrial e as principais fases das intoxicacoes ocupacionais sao descritos para o cloroformio, tetracloreto de carbono, metilcloroformio, tricloetileno e tetracloroetileno

Teratogenese quimica: um problema ocupacional?. / Chemical teratogenesis: an occupational program?

A possibilidade de aparecimento de malformacoes em recem-nascidos, cujas maes se expuseram a agentes ambientais, e relativamente bem conhecida. Entretanto, muito pouco se sabe das consequencias de uma exposicao continua a agentes quimicos ocupacionais. A incidencia de deformacoes devera, em virtude das caracteristicas dessa exposicao, ser muito maior em mulheres ocupacionalmente expostas do que nas demais. Algumas consideracoes sao feitas a respeito do risco no aparecimento desse efeito embriotoxico

Exposicao ocupacional ao sulfeto de carbono. / Occupational exposure to carbon sulphide

Reponsavel por mais de um tipo de acao toxica e com largo emprego industrial, o sulfeto de carbono constitui, segundo o presente trabalho, um exemplo tipico de substancia quimica, que se enquadra na categoria de compostos,cujo binomio causa-efeito nem sempre pode ser considerado. Medidas tecnicas de protecao,como ventilacao, exaustao, cortinas protetoras, sao aplicadas para reduzir as possibilidades de risco de exposicao a esse solvente. Contudo,estas se apresentam "quase sempre ineficientes para uma reducao tao drastica de sua concentracao no ambiente. O autor preconiza a introducao dos Limites de Tolerancia Biologicos (LTB)como medida suplementar para a determinacao da absorcao total do xenobiotico, "que devera estar aquem dos limites maximos toleraveis". A determinacao biologica do grau de exposicao ao sulfeto de carbono e comumente obtida atraves do teste cinetico da iodoazida. Relata, tambem, o mecanismo de acao toxica do CS considerando a velocidade e extensao da absorcao, a velocidade de eliminacao, a biotransformacao, os possiveis sitios de acao e, ainda, observa que a teoria do efeito quelante dos produtos de biotransformacao, os possiveis sitios de acao, e, ainda observa que a teoria do efeito quelante dos produtos de biotransformacao do CS2 e a mais promissora para elucidar o seu mecanismo de acao, sugerindo que estudos nesse sentido sejam intensos

Paraquat e diquat: aspectos toxicologicos. / Paraquat and diquat: toxicological aspects

Por apresentarem uma eficiente acao herbicida o Paraquat e o Diquat tem sido extensivamente aplicados a agricultura, para o controle e exterminio de ervas daninhas. A literatura existente sobre esses compostos, com relacao aos efeitos toxicos, restringe-se, quase que somente a exposicoes a curto prazo e a concentracoes elevadas que levam, via de regra, a intoxicacoes agudas, geralmente letais. Como o consumo desses compostos tende a aumentar, colocando em risco a saude dos trabalhadores expostos, principalmente nas zonas rurais, o autor apresenta os aspectos mais relevantes em todas as fases das intoxicacoes.Sao relatadas suas propriedades fisico-quimicas, mecanismo de acao herbicida, tipos de exposicao, toxocinetica e toxodinamica, bem como sinais e sintomas das intoxicacoes. Sugere, tambem, a analise para a determinacao qualitativa dos compostos em material biologico