Does malaoxon play a role in the geno- and cytotoxic effects of malathion on human choriocarcinoma cells?

This investigation was undertaken to elucidate whether the active metabolite of malathion, malaoxon, has any role in exerting cyto- and genotoxic effects for human choriocarcinoma (JAR) cell line which is an acceptable model for human placental cells. Gas chromatography-mass spectrometry (GC-MS) analysis were separately performed on the cell compartment and supernatant cell culture medium after subjecting the cell line to different malathion concentrations (10-400 µg/mL) and for various incubation periods (0.5 to 24 hours). GC-MS analysis showed that the sonication performed for the disruption of the cells did not cause the chemical change of malathion. The uptake of malathion by the cells was relatively fast. However, the presence of malaoxon, even in trace amounts, could not be confirmed either in samples originating from disrupted cells or in the cell culture medium. Although the hydrolysis of malaoxon occurred in the culture medium, this degradation process could not be counted as a reason for the absence of malaoxon. Since both malathion and malaoxon standard compounds could be accurately detected and distinguished by the applied liquid-liquid extraction and GC-MS methods, one can conclude that, in the case of JAR cells, the parent compound, (i.e. malathion itself) is responsible for the observed in vitro cyto- and genotoxic effects. Our results indicate that the direct toxicity of malathion contributes to the complications of pregnancy observed for environmental malathion exposure.

[Can the decrease of blood alcohol level be accelerated? Results of a clinical study]. / Gyorsítható-e a véralkoholszint csökkentése? Egy klinikai vizsgálat eredményei.

The purpose of this study was to examine the effect of Guardian Angel powder (GA) on the blood alcohol level. According to the experimental protocol, two sets of measurement were performed: modeling the eating and drinking habit of a typical family or social meeting, alcohol containing drinks corresponding to 70 g of pure alcohol and copious amount of food were consumed first without GA powder, then with GA powder. In the latter case GA powder was dissolved in water and one dose was taken before eating, the other one was consumed during eating. Blood samples were hourly collected from the volunteers in both sets for four hours. The measurement of blood alcohol level was performed by gas chromatography-mass spectrometry method proceeding to Solid Phase Micro Extraction (SPME). Our results show that the blood alcohol level decreased significantly when two doses of GA powder were consumed. After two hours of taking GA powder, the blood alcohol level was significantly lower in each volunteers compared to their own blood alcohol level measured in the absence of GA powder. This result shows that the individual variation of the alcohol metabolism does not influence significantly the effect of GA powder. Further studies are needed to investigate the detailed mechanism of the action of GA powder to find out whether GA powder influences the absorption of alcohol or/and the metabolism of alcohol.

Structural basis of the cofactor function of denatured albumin in plasminogen activation by tissue-type plasminogen activator.

Certain denatured proteins function as cofactors in the activation of plasminogen by tissue-type plasminogen activator. The present study approached the structural requirements for the cofactor activity of a model protein (human serum albumin). Heat denaturation of 100-230 microM albumin (80 degrees C and 60-90 min) reproducibly yielded aggregates with radius in the range of 10-150 nm. The major determinant of the cofactor potency was the size of the aggregates. The increase of particle size correlated with the cofactor activity, and there was a minimal requirement for the size of the cofactor (about 10 nm radius). Similar to other proteins, the molecular aggregates with cofactor function contained a significant amount of antiparallel intermolecular beta-sheets. Plasmin pre-digestion increased the cofactor efficiency (related to C-terminal lysine exposure) and did not affect profoundly the structure of the aggregates, suggesting a long-lasting and even a self-augmenting cofactor function of the denatured protein.

Maximum-entropy decomposition of fluorescence correlation spectroscopy data: application to liposome-human serum albumin association.

Fluorescence correlation spectroscopy was used to measure the diffusion behavior of a mixture of DMPC or DMPC/DMPG liposomes with human serum albumin (HSA) and mesoporphyrin (MP), which was used as the fluorescent label for liposomes and HSA as well. For decomposing the fluorescence intensity autocorrelation function (ACF) into components corresponding to a liposome population, HSA and MP, we used a maximum entropy procedure that computes a distribution of diffusion times consistent with the ACF data. We found that a simple parametric non-linear fit with a discrete set of decay components did not converge to a stable parameter set. The distribution calculated with the maximum entropy method was stable and the average size of the particles calculated from the effective diffusion time was in good agreement with the data determined using the discrete-component fit.