Comparative Analysis of QCM and Electrochemical Aptasensors for SARS-CoV-2 Detection.

The rapid and accurate detection of SARS-CoV-2, particularly its spike receptor-binding domain (S-RBD), was crucial for managing the COVID-19 pandemic. This study presents the development and optimization of two types of aptasensors: quartz crystal microbalance (QCM) and electrochemical sensors, both employing thiol-modified DNA aptamers for S-RBD detection. The QCM aptasensor demonstrated exceptional sensitivity, achieved by optimizing aptamer concentration, buffer composition, and pre-treatment conditions, with a limit of detection (LOD) of 0.

Metals - impact and implications.

Impact of metal in vitro administration on rat tissue oxygen consumption is referred in the first part. Toxicological implications of in vivo metal administration to rats and the study of potential penetration of metal into the rat brain, which may eventually result in oxygen radical production are presented in second part.

Study of the genotoxicity of toluene.

Chromosome analysis was conducted for peripheral lymphocytes of 23 printers exposed to toluene concentrations of 590 mg/m3 in a rotary machine workshop and to rotogravure printing inks. The percentages of aberrant cells were 2.30 in the printers and 1.

The IPCS Collaborative Study on Neurobehavioral Screening Methods: V. Results of chemical testing. Steering Group.

The IPCS Collaborative Study on Neurobehavioral Screening Methods was undertaken to determine the intra- and inter-laboratory reliability of a functional observational battery (FOB) and an automated assessment of motor activity in eight laboratories world-wide. Following the training phase and the conduct of proficiency studies in all laboratories, participants proceeded to test the effects of seven chemicals in both single dose and four-week repeated dosing scenarios. The chemicals studied were acrylamide, bisacrylamide, p,p'-DDT, lead acetate, parathion, toluene, and triethyl tin.

The IPCS Collaborative Study on Neurobehavioral Screening Methods: IV. Control data. Steering Group.

The goal of the International Programme on Chemical Safety (IPCS) Collaborative Study on Neurobehavioral Screening Methods was to determine the intra- and inter-laboratory reliability of a functional observational battery (FOB) and an automated assessment of motor activity in eight laboratories worldwide. The control data were crucial to the outcome of the studies in terms of sensitivity and reliability of the test measures, which in turn impact on the between-laboratory comparisons of chemical effects. In addition, analyses of control data can aid in determining endpoints that may require modification to improve their sensitivity and reliability.

The IPCS Collaborative Study on Neurobehavioral Screening Methods: III. Results of proficiency studies. Steering Group.

The goal of the IPCS Collaborative Study on Neurobehavioral Screening Methods was to determine the intra- and inter-laboratory reliability of a functional observational battery (FOB) and an automated assessment of motor activity in eight laboratories world-wide. The first phase of the Collaborative Study involved training the participants: evidence of training was then evaluated using positive-control compounds. The positive-control studies required the laboratories to identify, using the FOB, specific neurotoxic syndromes produced by acute exposure to p,p'-DDT, parathion, and by short-term repeated dosing with acrylamide.

Pattern of inhalation exposure: blood levels and acute subnarcotic effects of toluene and acetone in rats.

Solvent blood concentrations and subnarcotic effects (inhibition of electrically evoked seizures) were measured in rats exposed to constant or fluctuating air concentrations of toluene or acetone. A 4 hour exposure of resting rats to toluene at an air concentration of 1 and 2 mg/l, or to acetone at 4 and 10 mg/l, led to blood levels of 6.7 and 12.

The influence of a magnetic field on manganese transport into rat brain.

The aim of this study was to detect the effect of a magnetic field on manganese transport into rat brains. An experimental group of Female Wistar rats was given 0.48 mg Mn2+ per kg body weight intratracheally twice a week for 3 months and simultaneously exposed to a magnetic field: B = 10 mT, f = 50 Hz for 1 hr.

Oxidative phenotype polymorphism (P450 2D6) and metabolism of toluene.

Oxidative phenotype P-450 2D6 was examined using sparteine test in 3 groups of persons to determine if there is a coincidence in the defect of the oxidative biotransformation of sparteine and impaired oxidation of toluene, which could explain interindividual differences in the amounts of hippuric acid in the urine in exposed persons. The following groups of persons were examined: 30 rotogravure printers exposed to toluene vapors at concentrations of 8-307 ppm; 20 workers, 2 months after the cessation of the long-term exposure to toluene at concentrations of 104-1,170 ppm; 48 healthy volunteers with no exposure to toluene. Among the 98 persons 5 poor metabolizers (PMs) of sparteine were found, none in the group of printers exposed to toluene.

Neurotoxicity profile of supermethrin, a new pyrethroid insecticide.

The use of a standard two-tier neurotoxicity screening procedure in the context of risk assessment is exemplified. Testing of a new pyrethroid in rats addressed the following sequence of questions: Does the substance evoke neurotoxic symptoms in sublethal doses? Do these symptoms reflect a primary neurotropic action? What are the dynamic characteristics of injury, the clinical profile of effect, and the relative potency of the tested substance compared to similar compounds? - The testing protocol is an animal analogue of a systematic neurological and psychological examination in man. First tier tests (structured observation, motor activity measurement, simple neurological examination) were applied after the first dose, during repeated dosing phase and in the restitution phase.

Relative acute neurotoxicity of solvents: isoeffective air concentrations of 48 compounds evaluated in rats and mice.

Effect-air concentration regressions of 48 common solvents (aromatic, aliphatic, and chlorinated hydrocarbons, alcohols, ketones, acetates) were determined for 4-hr inhalation exposures in male rats and for 2-hr exposures in female mice. Inhibition of propagation and maintenance of the electrically evoked seizure discharge was used as a criterion of the acute neurotropic effect. The isoeffective concentrations in air were estimated by interpolation on the level of one-third of the maximum effect (ECC).