Characterization and in vitro sensitivity of cholinesterases of gilthead seabream (Sparus aurata) to organophosphate pesticides.

The characterization of cholinesterase activity in brain and muscle of gilthead seabream was carried out using four specific substrates and three selective inhibitors. In addition, K and V were calculated from the Michaelis-Menten equation for ASCh and BSCh substrates. Finally, the in vitro sensitivity of brain and muscle cholinesterases to three organophosphates (OPs) was also investigated by estimating inhibition kinetics.

Simplification of iron speciation in wine samples: a spectrophotometric approach.

A simple direct spectrophotometric method was developed for the analysis of Fe(II) and total Fe in wine samples. This method is based on the formation of an Fe(II) complex with 2,2'-dipyridylketone picolinoylhydrazone (DPKPH), which shows a maximum green-blue absorption (λ = 700 nm) at pH 4.9.

Toxicity of parathion on embryo and yolk-sac larvae of gilthead seabream (Sparus aurata l.): effects on survival, cholinesterase, and carboxylesterase activity.

This study was conducted to examine the acute toxicity of the organophosphorus pesticide (OP) parathion on embryos and yolk-sac larvae of gilthead seabream (Sparus aurata), and to investigate the effects of this compound on cholinesterase and carboxylesterase activity of seabream larvae in the phase of endogenous feeding. The 72-h LC50 for yolk-sac larvae (0.523 mg L⁻¹) was about two-fold lower than the 48-h LC50 for embryos (1.

Cholinesterase activity in gilthead seabream (Sparus aurata) larvae: Characterization and sensitivity to the organophosphate azinphosmethyl.

Assessment of cholinesterase (ChE) inhibition is widely used as a specific biomarker for evaluating the exposure and effects of non-target organisms to anticholinesterase agents. Cholinesterase and carboxylesterase activities have been measured in larvae of gilthead seabream, Sparus aurata, during the endogenous feeding stage, and ChE was characterized with the aid of diagnostic substrates and inhibitors. The results of the present study showed that whole-body ChE of yolk-sac seabream larvae possesses typical properties of acetylcholinesterase (AChE) with a apparent affinity constant (K(m)) of 0.

Comparative toxic effects of formulated simazine on Vibrio fischeri and gilthead seabream (Sparus aurata L.) larvae.

The use of Early Life Stage (ELS) tests is a useful tool in risk assessment. The purpose of this study was to compare the sensitivity of the seabream (Sparus aurata) larvae with the extensively used Microtox test on a commercial formulation containing simazine, an s-triazine herbicide. To this end, survival, growth and histopathological changes displayed by seabream yolk sac larvae exposed during 72 h post-hatching to nominal concentrations of the commercial preparation up to its saturating concentration in water, and bioluminescence of the marine bacteria Vibrio fischeri (Microtox) were studied.

Toxicity of a commercial herbicide containing terbutryn and triasulfuron to seabream (Sparus aurata L.) larvae: a comparison with the Microtox test.

The present study aimed to compare the sensitivity of larvae of the gilthead seabream (Sparus aurata), a valuable fish species of the Spanish South Atlantic littoral, with the extensively used Microtox test on a commercial herbicide formulation containing terbutryn (59.4%) and triasulfuron (0.6%).

Oxidation of cholinesterase-inhibiting pesticides: A simple experiment to illustrate the role of bioactivation in the toxicity of chemicals.

A simple undergraduate laboratory experiment that can be used in Biochemistry and Toxicology courses to illustrate the importance of metabolic reactions in the toxicity of chemical substances is reported. It involves the experimental confirmation that oxidized phosphorothionate esters, commonly used as insecticides, are stronger cholinesterase inhibitors and therefore exhibit higher toxicity than do their sulphur analogs starting from which the first are formed by in vivo oxidative desulphuration. Two separated aliquots of a bovine blood sample are incubated with parathion and paraoxon, its oxygen analog, and compared for cholinesterase activity with "normal" blood.

A study on ten short tandem repeat systems: African immigrant and Spanish population data.

This work presents the results obtained from a genetic-population study for the D1S1656 system in the population of Southwest Spain (Huelva, Cádiz and Sevilla), Spaniards of Caucasian origin from North Africa (Ceuta), as well as in the black Central West African and Moroccan immigrant populations in Spain. The results of a study of the autochtonous population of the Canary Islands (n=138), and immigrant Central West African populations in Spain (n=132), obtained for nine short tandem repeat (STR) loci (D3S1358, VWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D7S820), as well as the amelogenin locus, all contained in Profiler Plus (Perkin-Elmer) PCR amplification kits, are also presented. Except for the FGA and VWA data on immigrant Central West African populations in Spain, no deviations from the Hardy-Weinberg equilibrium were detected.

A study among the population of Sevilla of death due to submersion.

Death due to submersion is of great interest from the medical-legal point of view, given the increase in nautical activity among children and adults alike over the past number of years. However, the lack of reliable statistical data concerning the impact of this specific form of death in our country must be emphasized. These are the circumstances that have led us to study the incidence of this form of death in a specific area.

Precision of estimating time of death by vitreous potassium--comparison of various equations.

This paper is a study of the precision of estimating the time since death comparing the equations developed by different authors. Our aim is to determine with the maximum degree of accuracy the exact time of death of the individual. We consider that the study has been fully justified by the observed differences in the results obtained from the different equations under study when the concentration of potassium in the vitreous humour was identical.

Group-specific component (GC) polymorphism in Cádiz (southern Spain).

The genetic polymorphism of group-specific component (GC) was analysed in a sample of 443 healthy unrelated subjects of both sexes resident in the province of Cádiz (Southern Spain). Isoelectric focusing was carried out in polyacrylamide gels followed by staining with coomassie blue R 250. The estimated gene frequencies were as follows: GC*1S = 0.

Polymorphisms of the enzyme systems galactose-1-phosphate uridyltransferase (GALT) and esterase D (EsD) in the province of Cádiz, southern Spain.

Galactose-phosphate uridyltransferase (GALT) and esterase D (EsD) phenotypes were determined by isoelectric focusing in ultrathin-layer polyacrylamide gel (PAGIF) for 406 healthy subjects randomly chosen and residing in the province of Cádiz, in Southern Spain. The following gene frequencies were observed: for GALT, GALT1 = 0.952 970 3 and GALT2 = 0.

Polymorphism of the plasminogen (PLG) system in Cádiz Province, southern Spain.

In this work, the authors report a plasminogen (PLG) system genetic-population study in a sample of 378 healthy subjects, of both sexes and unrelated, all resident in the province of Cádiz in Southern Spain. In this study, the PLG types were determined by isoelectric focusing in polyacrylamide gels (PAGIF), followed by staining with Coomassie blue. The genic frequencies obtained were the following: PLG A = 0.