Evaluation of the Test-mate ChE (cholinesterase) field kit in acute organophosphorus poisoning

STUDY OBJECTIVE: Measurement of acetylcholinesterase (AChE) is recommended in the management of organophosphorus poisoning, which results in 200,000 deaths worldwide annually. The Test-mate ChE 400 is a portable field kit designed for detecting occupational organophosphorus exposure that measures RBC AChE and plasma cholinesterase (PChE) within 4 minutes. We evaluate Test-mate against a reference laboratory test in patients with acute organophosphorus self-poisoning. METHODS: This was a cross-sectional comparison study of 14 patients with acute organophosphorus poisoning between May 2007 and June 2008. RBC AChE and PChE were measured in 96 and 91 samples, respectively, with the Test-mate ChE field kit and compared with a reference laboratory, using the limits of agreement method (Bland and Altman), κ statistics, and Spearman's correlation coefficients. RESULTS: There was good agreement between the Test-mate ChE and the reference laboratory for RBC AChE. The mean difference (Test-mate-reference) was -0.62 U/g hemoglobin, 95% limits of agreement -10.84 to 9.59 U/g hemoglobin. Good agreement was also observed between the categories of mild, moderate, and severe RBC AChE inhibition (weighted κ 0.85; 95% confidence interval [CI] 0.83 to 0.87). Measurement of PChE also showed good agreement, with a mean difference (Test-mate-reference) of +0.06 U/mL blood, 95% limits of agreement -0.41 to 0.53 U/mL blood. Spearman's correlation coefficients were 0.87 (95% CI 0.81 to 0.91) for RBC AChE and 0.76 (95% CI 0.66 to 0.84) for PChE. Analysis for within-subject correlation of subjects did not change the limits of agreement. CONCLUSION: The Test-mate ChE field kit reliably provides rapid measurement of RBC AChE in acute organophosphorus poisoning.

Cholinesterase measurements with an automated kit

Background the Test-mate kit determines acetylcholinesterase (AChE, EC 3.1.1.7) and hemoglobin content of a drop of blood, displaying enzyme activities normalized to 25degreesC. Previous models produced inconsistent results at different temperatures. This report focuses on the current model, ChE 400, and two instruments of a previous OP model.Methods AChE activities were determined by the Ellman assay, using the three kits and a 96-well microplate reader Temperatures ranged from 10 to 37degreesC. Fetal bovine serum was the source of AChE.Results Normalized activities decreased below 20degreesC in the ChE model and below 25 C in the OP models. Activities of the same serum sample differed between the three Test-mate kits, ranging from 1.03 to 1.49 mumoles/min/ml. Percent errors were greater than with the microplate reader at all temperatures.Conclusions Neither we nor the manufacturer recommend the current Test-mate model for fieldwork. Nevertheless, there have been field measurements with Test-Mate kits, and we recommend that an enzyme activity standard be run in parallel with their use. (C) 2002 Wiley-Liss, Inc.

Efeito antimutagênico, antigenotóxico, antiobesidade e antioxidante da Ilex paraguariensis (erva-mate)

O extrato aquoso de erva-mate, obtido a partir de folhas secas de Ilex paraguariensis, é uma bebida amplamente consumida na América do Sul. Inicialmente, nosso objetivo foi caracterizar os compostos presentes nas amostras de erva-mate disponíveis no mercado brasileiro (CH: chimarrão; T: chá mate torrado; G: chá mate torrado, comercialmente acondicionado em garrafas ou C: em copos; TS: chá mate torrado solúvel A mutagenicidade, citotoxicidade e antimutagenicidade de todas as amostras também foram avaliadas atavés do Teste de Ames na presença e na ausência de ativação metabólica. Em seguida, analisamos a amostra TS (2,5, 5,0 e 10 mg/mL) quanto a sua atividade antioxidante e antigenotóxica. Além disso, avaliamos também os efeitos da amostra TS sobre a sinalização da leptina e da insulina no hipotálamo e o estresse oxidativo hepático de ratos adultos obesos programados pela superalimentação neonatal (S). Para induzir S, o tamanho da ninhada foi reduzido a três filhotes por lactante e as ninhadas com número padrão de filhotes (dez/lactante) foram utilizadas como controle. Aos 150 dias de vida, as proles S foram subdivididas em: TS - tratados com extrato aquoso de erva-mate (1g/kg de peso corporal/dia, por gavagem) e S - recebendo água por gavagem durante 30 dias. A prole controle (C) também recebeu água nas mesmas condições do grupo S. Em nossos resultados, verificamos a presença de ácido clorogênico, cafeína e teobromina em todas as amostras analisadas. O conteúdo de compostos fenólicos nas infusões estudadas foram CH: 5,140,23; T: 4,330,01; G: 0,930,25; C: 0,800,3 e TS: 8,350,5 mg/ml. Não observamos efeito mutagênico ou citotóxico nas amostras analisadas. Um efeito antimutagênico significativo foi observado para a cepa TA97 (pré-, co- e pós-tratamento), na presença de ativação metabólica, em todas as amostras testadas. A amostra TS também apresentou um efeito antimutagênico significativo para a TA102 (pré-, co-e e pós-tratamento), na presença de ativação metabólica. Na análise exclusiva da amostra TS, observamos uma atividade antioxidante quando utilizado o ensaio de DPPH, apresentando IC50 69,3+3,1 μg/ml. Além disso, a amostra TS apresentou um efeito protetor sobre a quebra do DNA plasmidial induzida por radicais superóxido e hidroxila, de maneira dose dependente. No teste do cometa, detectamos um efeito antigenotóxico induzido pelo TS em cultura primária de células epiteliais de esôfago. Em nossos testes in vivo observamos que os animais TS não desenvolveram sobrepeso, obesidade visceral e hiperfagia. A resistência hipotalâmica à leptina não foi significativamente revertida, porém a resistência à insulina foi minimizada pelo tratamento com TS no grupo programado pela S. No fígado, TS normalizou as atividades das enzimas antioxidantes (SOD, GPx e CAT) e diminuiu os marcadores de estresse oxidativo, MDA e 4-HNE. O tratamento com TS também reduziu o conteúdo de glicogênio e triglicerídios hepáticos. Nossos resultados sugerem que a erva-mate foi capaz de proteger o DNA contra danos oxidativos, aumentou as defesas antioxidantes, melhorou a função hepática em ratos superalimentados na lactação, talvez através da modulação da sinalização hipotalâmica da insulina podendo ser, portanto, uma importante ferramenta para prevenção e tratamento de doenças relacionadas ao estresse oxidativo.

Sexual cannibalism and mate choice

Sexual cannibalism, where a female kills and consumes a courting male, represents an extreme form of sexual conflict and has been proposed as a mechanism of mate choice. We evaluate the evidence for mate choice through premating sexual cannibalism via mate rejection, other indirect mechanisms of mate 'choice' and choice in postmating sexual cannibalism. We highlight a paucity of investigations, particularly of field studies, and note gaps in our knowledge. There is empirical support for the size-dependent sexual cannibalism predicted by mate choice through premating sexual cannibalism. This may represent mate choice operating on absolute male size but it could be a by-product of female foraging behaviour and greater vulnerability of relatively smaller males. Thus, indirect mate choice is as plausible an explanation of size-dependent sexual cannibalism as is direct mate choice based on discrimination of male traits. Direct female choice, mediated through premating sexual cannibalism, has yet to be demonstrated. We suggest a framework for distinguishing direct and indirect choice and note an absence of information on which to test it. There is evidence for sequential mate choice in postmating sexual cannibalism, but the nature or basis of the female's discriminatory behaviour remains unclear. Costs and long-term fitness benefits of the putative mate choice have been largely ignored. Reversed sexual cannibalism, in which the male eats the female, presumably occurs when the gain from food is high and potential gain from mating low and probably has little to do with mate choice. (c) 2005 The Association for the Study of Animal Behaviour Published by Elsevier Ltd. All rights reserved.

Size-assortative pairing in Gammarus pulex (Crustacea : Amphipoda): a test of the timing hypothesis

We present the first empirical test of the timing hypothesis regarding the generation of size-assortative pairing in amphipods. The timing hypothesis proposes that, since large males are better able to afford the costs of mate guarding than small males, the former can take larger females into precopula earlier in the female moult cycle than is feasible for the latter. This leaves small males to form pairs with smaller females closer to moult, thus generating size assortment. We presented male Gammarus pulex, collected both in precopula and as singletons, with females that were (1) previously guarded and therefore near to copulatory moult and (2) previously unguarded and therefore far from copulatory moult. This comparison tested the prediction of the timing hypothesis, that size assortment should break down when the opportunity for time-based male decisions is removed, but that size assortment should occur where timing is not disrupted. Counter to the hypothesis, we found that size assortment did not break down upon removal of the time factor. Large males tended to initiate mate guarding earlier than small males in both female moult groups. However, only in the previously unguarded group did large males guard for longer than small males. This result suggests that, although size assortment occurred in all groups, the causative mechanisms that generated this pattern may differ between these groups. We therefore consider the possible importance of mechanisms such as aggression, simultaneous manipulation of females and female resistance in producing size assortment where males encounter numerous females that are close to moult. We also observed that prior recent guarding experience by males had no effect on latency to guard or size-assortative pairing. (C) 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.

Attractive silences in cricket courtship song : mate choice using a short-range signal /

Matings systems using signals for sexual communication have been studied extensively and results commonly suggest that females use these signals for locating males, species-identification, and mate choice. Although numerous mating systems employ multiple signals, research has generally focused on long-range signals perhaps due to their prominence and ease of study. This study focused on the short-range acoustic courtship song of crickets. The results presented here suggest this signal is under selection by female choice. Females mated preferentially with males having shorter silences between the two types of ticks within the song. The length of these silences (Gap 1) was correlated with male condition such that males having long silences were significantly lower in mass with respect to body size when compared to males having short silences. Both Gap 1 length and male condition were significantly repeatable within males over time suggesting the possibility these traits have a genetic basis. This study is the first empirical study to test female preferences within the natural variation of the courtship song. It now appears, at least in crickets, that both the longand short-range signals of a multi-signal mating system may contribute to male mating success.

Différence intersexuelle dans la jalousie : un test de l’hypothèse émotionnelle

Selon certains modèles évolutionnistes, les femmes seraient davantage affectées par l’infidélité émotionnelle de leur partenaire masculin que par son infidélité sexuelle. Les mécanismes psychologiques responsables auraient évolué pendant notre passé de chasseur-cueilleur de façon à assurer à la femme un accès exclusif aux ressources économiques provenant du partenaire. Or la situation économique des femmes d’aujourd’hui a considérablement changé depuis cette époque, plusieurs d’entre-elles étant indépendantes financièrement. Dans la présente recherche, nous testons l’hypothèse que les femmes qui sont indépendantes financièrement sont moins intensément, ou moins rapidement, jalouses que les femmes qui dépendent financièrement de leur partenaire. Nous cherchons aussi à savoir si le nombre d’enfants, ou certains traits de personnalité ont une influence sur la jalousie. L’échantillon était constitué d’une soixantaine de femmes et les données proviennent de questionnaires et de mises en situation fictives. Nos résultats ne supportent pas l’hypothèse principale, les divers sous-groupes de femmes étant jalouses à la même intensité. Nous considérons divers facteurs pouvant expliquer l’absence de différences, par exemple, la possibilité que certains aspects de la relation de couple puissent cacher l’effet de la situation économique des femmes. D’autres résultats montrent une différence significative dans l’intensité de la jalousie selon l’identité de la personne en relation avec le partenaire (ancienne versus nouvelle amie). Ces résultats sont aussi évalués dans une perspective évolutionniste.

Ultraviolet plumage colors predict mate preferences in starlings

Avian plumage has long been used to test theories of sexual selection, with humans assessing the colors, However, many birds see in the ultraviolet (<400 nm), to which humans are blind, Consequently, it is important to know whether natural variation in UV reflectance from plumage functions in sexual signaling, We show that female starlings rank males differently when UV wavelengths are present or absent, Principal component analysis of approximate to 1300 reflectance spectra (300-700 nm) taken from sexually dimorphic plumage regions of males predicted preference under the UV+ treatment. Under UV- conditions, females ranked males in a different and nonrandom order, but plumage reflectance in the human visible spectrum did not predict choice, Natural variation in UV reflectance is thus important in avian mate assessment, and the prevailing light environment can have profound effects on observed mating preferences.

Ultraviolet vision and mate choice in zebra finches

SEXUAL selection is one of the most actively studied areas of evolutionary biology(1-3), and ever since Darwin(1) birds have been probably the most popular taxon for testing the predictions about colour variation. Humans have been used to assess 'colour', an approach which may be flawed(4,5) as many birds see in the ultraviolet (to which humans are blind), and have at least four spectral classes of retinal cone cells (humans have only three), Here we report experiments on zebra finches which test the hypothesis that the ultraviolet waveband (300-400 nm) is used in avian mate-choice decisions. We found that the ultraviolet is used, and that it probably contributes to hue perception. This finding may have,vide implications for future studies of avian sexual selection and colour, and supports one hypothesized function of avian ultraviolet vision, the role of which is largely unknown.(4,6,7)

Developmental stress and female mate choice behaviour in the zebra finch

The potential effects of early environmental conditions on adult female mate choice have been largely neglected in studies of sexual selection. Our study tested whether developmental stress affects the mate choice behaviour of female zebra finches, Taeniopygia guttata, when choosing between potential mates. In an experiment manipulating developmental condition, female zebra finches were raised under nutritional stress or control conditions. In adulthood, female preferences were assessed using extensive four-stimulus mate choice trials. Nutritional stress affected growth rates during the period of stress, with experimentally stressed females lighter than controls. During mate choice trials stressed females were almost three times less active than controls and made fewer sampling visits to the stimulus males, although we found no evidence of a direct effect of developmental experience on which males were preferred. Thus, developmental experience had a clear effect on behavioural patterns in a mate choice context. To test whether this effect is specific to a mate choice context, we also investigated the effect of developmental stress on female activity rates in three social contexts: isolation, contact with a conspecific male (a potential mate) and contact with a conspecific female. Here, female activity did not differ between the experimental treatments in any of the social situations. Overall, our findings suggest that environmental conditions during early development can have long-term context-dependent consequences for adult female mate choice behaviour, mediated by changes in activity rates.

Trade-offs and implicit preferences in human mate selection

Two novel to domain research methods - choice modelling and the implicit Association Test (IAT) - were applied to measure trade-offs and implicit preferences in human mate preferences. Collectively, findings from four experiments supported the explanatory superiority of Sexual Strategies Theory as a model of between sex and within sex variability in mate preferences.

Melhoramento genético de erva-mate nativa do Estado de Mato Grosso do Sul

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeitos da temperatura e do mate (Ilex paraguariensis) sobre o processo de carcinogênese de esôfago em ratos wistar machos

Pós-graduação em Biologia Geral e Aplicada - IBB

Efeito do consumo agudo de erva mate sobre o rendimento fisíco em esteira ergométrica e indicadores metabólicos da exaustão em jogadores profissionais de futebol

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)