Fatty acid esters of juvenoid alcohols as insect hormonogen agents (juvenogens)

A series of 8 new juvenogens (3--10) was prepared starting from a pair of isomeric insect juvenile hormone bioanalogues ( and ). The biological activity of the juvenogens -- was tested for their effect on reproduction of the blowfly Neobellieria (Sarcophaga) bullata and for the juvenilizing activity on the termite Prorhinotermes simplex. Results of biological screening are important in structure--activity studies and promising for potential practical application of some of the juvenogens studied, especially against termites.     

Is ADHD adaptive or non-adaptive behavior?

The evolutionary approach to the issue of ADHD derives from the assumption that what is regarded as a pathological phenomenon today was once an adaptive response to the conditions of life in the ancestral stages of human development. The paper argues against this conception on the basis of the clinical picture of ADHD. The author believes that in the previous "natural" conditions the ADHD syndrome was even more of a maladaptation than in the "protective" conditions of present-day life.     

DNA-adducts and atherosclerosis: a study of accidental and sudden death males in the Czech Republic

Atherosclerosis and carcinogenesis may share some common mechanisms of the genotoxic action of exogenous compounds, such as polycyclic aromatic hydrocarbons (PAHs). The main objective of this study was to test the hypothesis that "bulky" aromatic DNA-adducts in smooth muscle cells (SMCs) of thoracic aortas taken at autopsy from sudden and accidental death male subjects, aged between 30 and 60 years (N=133), are associated with the stage of atherosclerosis. The subjects with severe atherosclerotic damage were treated as "Cases" (N=66). The subjects meeting diagnostic criteria for slight and moderate total atherosclerotic body damage were treated as "Controls" (N=67). An additional objective of the study was to evaluate the effect of known atherogenic risk factors and possible modifiers of atherosclerotic changes, such as age, smoking, plasma lipid and antioxidant vitamin levels and some genetic susceptibility markers, e.g. polymorphisms of GSTM1, GSTT1, NAT2, CYP1A1 or apolipoprotein E (APO E) genes. We found significantly higher DNA-adduct levels in "Cases" as compared with "Controls" (2.11+/-1.07 adducts/10(8) nucleotides versus 1.49+/-0.55 adducts/10(8) nucleotides, P<0.001). "Cases" were significantly older and had elevated heart weight and plasma cholesterol levels and a higher frequency of overweight subjects as compared with "Controls". No significant differences in DNA-adduct levels between smokers and non-smokers within either group were detected. Multivariate logistic regression revealed that the "bulky" aromatic DNA-adducts, which are the most likely related to environmental exposure to genotoxic chemicals, remain a statistically significant predictor of the stage of atherosclerosis (OR=3.76, 95% CI=1.54-9.18, P=0.004) even after adjustment for age, smoking, obesity, heart weight and genetic susceptibility markers (GSTT1 and CYP1A1-MspI polymorphisms) that were also significant predictors. The fact that the "bulky" aromatic DNA-adduct levels predict the progression of atherosclerosis independently of smoking indicates that the formation of atherosclerotic plaques may also be initiated by environmental exposures other than tobacco smoke.     

Evaluation of the efficiency of extraction of ultraviolet-absorbing pollen allergens and organic pollutants from airborne dust samples by capillary electromigration methods

Capillary electromigration methods, zone electrophoresis (CZE) and micellar electrokinetic chromatography (MEKC), have been used for evaluation of the efficiency of different extraction agents applied to the extraction of pollen allergens and organic pollutants from dust samples collected during different periods (before, during and after pollen seasons) and in different locations in air-filtration devices (car-traffic tunnel in Prague and a metro station in Paris). Water and acetic acid extracts were analyzed by CZE using acetic acid as background electrolyte (BGE). Water and alkaline water-SDS-buffer extracts were analyzed by MEKC in Tris-phosphate BGE with anionic detergent sodium dodecylsulfate (SDS) micellar pseudophase. More material was extracted and more components were found in the water-buffer extracts than in the water extracts, and better resolution of the components was achieved by MEKC than by CZE. Significant differences have been found in the analyses of dust extracts of different origin. More material and more components have been found in the extracts of the dust collected in the pollen-rich period (March, April) than in the pollen-free period (December, January).     

A simple,optimized method for the determination of sulphide in whole blood by GC-mS as a marker of bowel fermentation processes

Hydrogen sulphide is produced in human large intestine by anaerobic fermentation and may play a pathogenic role. An analytical method for determination of sulphide in whole blood using an extractive alkylation technique was optimised and validated for this purpose. The sample was mixed with organic phase containing pentafluorobenzyl bromide as an alkylating agent. The benzalkonium chloride was used as a phase-transfer catalyst. The quantitative determination was performed using GC-MS technique in selected ion monitoring mode. The blood levels of sulphide of healthy controls were measured (35-80 microM/l). The method is versatile, reproducible (RSD=2.7%) and suitable for research of anaerobic fermentation in vivo.     

Reversed-phase liquid chromatographic-mass spectrometric determination of microcystin-LR in cyanobacteria blooms under alkaline conditions

Reversed-phase HPLC coupled to the atmospheric pressure ionization-electrospray ionization (API-ESI) MS was used for microcystin-LR detection and quantitation in samples of dried Microcystis aeruginosa cells. An alkaline linear gradient (20 mmol/l ammonium hydroxide-acetonitrile, pH 9.7) was used for elution of the toxic peptides. Limit of detection was 1 microg/ml (20 ng per injection) in the scan mode of MS and 0.1 microg/ml (2 ng per injection) in the case of selective ion monitoring.     

Peripheral venous hypertension after the creation of arteriovenous fistula for haemodialysis

The function of an arteriovenous (av) fistula for haemodialysis may be complicated by manifestation of peripheral venous hypertension, which results from the arterial blood flow through the venous system into the periphery of the upper extremity. Its development is most typically caused by a proximal forearm av-fistula, as, in addition to the desirable arterialisation of the subcutaneous venous system of the arm, arterialisation of the venous system of the forearm and the hand may occur and possibly promote the development of venous hypertension, which may in the extreme result in gangrene of the fingers. Awareness of these problems as well as of the necessity of their surgical solution is essential for doctors dealing with haemodialysis.     

Disruption of microtubules leads to glucocorticoid receptor degradation in HeLa cell line

The role of microtubules (MTs) in steroid hormone-dependent human glucocorticoid receptor (hGR) activation/translocation is controversial. It was demonstrated recently that colchicine (COL) down-regulates hGR-driven genes in primary human hepatocytes by a mechanism involving inhibition of hGR translocation to the nucleus. To investigate whether inhibition of hGR translocation is the sole reason for its inactivation, we used human cervical carcinoma cells (HeLa) as a model. Herein we present evidence that perturbation of microtubules in HeLa cells leads to rapid time- and dose-dependent degradation of hGR protein. Degradation is proteasome mediated as revealed by its reversibility by proteasome inhibitor MG132. Moreover, degradation was observed for neither wt-hGR nor hGR mutants S226A and K419A in transiently transfected COS-1 cells. On the other hand, c-jun N-terminal kinase (JNK) seems not to be involved in the process because JNK inhibitor 1,9-Pyrazoloanthrone (SP600125) does not reverse hGR degradation. Similarly, another hGR functional antagonist, nuclear factor kappa beta (NFkappaB), did not play any role in the degradation process.