Effect of chronic vanadium administration in drinking water to rats

Two-month old Wistar rats of both sexes received, as sole drinking liquid, an aqueous solution of ammonium metavanadate (AMV) at a concentration of 0.01 or 0.05 mg V cm^–3 (0.2 or 1.0 mM) for a period of 4 weeks. It was calculated that the animals took up doses of 1.5 and 5–6 mg V kg body weight^–1 24 h^–1, respectively. Food and AMV solution consumption in the experimental groups was similar to food and water consumption in the control group. A statistically significant decrease of consumption of AMV solution at a concentration of 0.05 mg V cm^–3 was noted only in males. Hematological examination demonstrated a decrease in the erythrocyte count, hemoglobin level and hematocrit index. This decrease in the erythrocyte count was associated with an increased percentage of reticulocytes in the peripheral blood of the animals drinking the solution with a higher vanadium content. Biochemical analyses demonstrated a decrease of l-ascorbic acid levels in the plasma and erythrocytes of animals drinking the AMV solutions. A distinct tendency for the malonyldialdehyde level to increase in the blood was also observed. Among the enzymes examined in the erythrocytes (catalase, glucose-6-phosphate dehydrogenase, lactate dehydrogenase and -aminolevulinic acid dehydratase [ALA-D]) only ALA-D activity was depressed.     

The relationship between airborne pollen and fungal spore concentrations and seasonal pollen allergy symptoms in Cracow in 1997–1999

The investigation of airborne pollen and fungalspore concentrations was carried out in Cracowbetween 1997–1999. For this study thevolumetric method has been employed (Burkard).At the same time the clinical diagnosis ofpollen allergy in 40 patients was obtained onthe basis of an interview, positive skin pricktests with pollen extracts and increasedspecific IgE level. An increase in seasonalallergy symptoms in all patients occurred fromthe middle of May to the middle of August.Eighty eight percent of the patients (35 out of40) were sensitive to Poaceae pollen and about50% of them were additionally sensitive totree and herb pollen excluding grasses. Forpatients with additional allergy to tree pollenthe seasonal symptoms started at the end ofMarch (Betula) while for patients withadditional allergy to herb pollen it wasextended to the middle of September (Artemisia).Five people out of 40 revealed positive skinreactions to Alternaria spores and anincrease in specific IgE level. Positive skinreaction to Cladosporium spores with noincrease in specific IgE level occurred in 2patients. The increase in seasonal allergysymptoms in people sensitive to Alternariaspores noted in July and August could becaused not only by these spores but also byPoaceae pollen.     

Equivalent models of indanol isomers adsorption on cellulose tribenzoate

The adsorption isotherm data of (R)- and (S)-1-indanol and of their racemic mixture on cellulose tribenzoate were measured by frontal analysis. The experimental data for each enantiomers were fitted to the single-component bilangmuir isotherm model. The competitive experimental data were fitted to the ideal adsorption solution model (IAS), the real adsorption solution model (RAS), and the bilangmuir thermodynamically consistent model (BTC). The mass transfer kinetic parameters were estimated from systematic comparisons between the experimental single-component band profiles and profiles calculated using the general rate model (GR) of chromatography coupled with the generalized Maxwell-Stefan equation (GMS). The validation of the isotherm model and of the mass transfer kinetic model was made by comparing the experimental band profiles obtained for solutions of the two enantiomers and those calculated with the competitive GR-GMS model. The excellent agreement observed proves that a combination of the BTC isotherm model and the GMS kinetic model, using the best values of the BTC and GMS parameters estimated from single component experiments, allows an excellent prediction of the binary isotherm and the binary mass transfer kinetics.     

Presence of histamine and mast cells in chicken oviduct

The purpose of the present study was: (1) to demonstrate immunocytochemically the localization of histamine in the wall of four chicken oviductal parts, i.e. infundibulum, magnum, isthmus, and shell gland, (2) to identify the presence of mast cells in chicken oviduct, and (3) to determine histamine concentration in oviductal tissue by the spectrofluorometric method. Experiments were carried out on Isa Brown laying hens decapitated just after oviposition. The specific immuno-reactivity for histamine and the presence of mast cells were found in the wall of all the examined oviductal parts. The immuno-reactive histamine was localized in epithelium, tubular glands, connective tissue layer, circular and longitudinal muscles, and endothelium and muscles of blood vessels. The intensity of immuno-positive reaction was as follows: infundibulum > shell gland > magnum = isthmus and correlated with quantitatively determined histamine level and tissue density of mast cells. It is suggested that mast cells are the main source of histamine in the chicken oviduct.     

Cloning,expression, and purification of the His6-tagged hyper-thermostable dUTPase from Pyrococcus woesei in Escherichia coli: application in PCR

The gene encoding dUTPase from Pyrococcus woesei was cloned into Escherichia coli expression system. It shows 100% gene identity to homologous gene in Pyrococcus furiosus. The expression of N-terminal His(6)-tagged Pwo dUTPase was performed in E. coli BL21(DE3)pLysS and E. coli Rosetta(DE3)pLysS strain that contains plasmid encoding additional copies of rare E. coli tRNAs. E. coli Rosetta(pLysS) strain was found with two times higher expression yield of His(6)-tagged Pwo dUTPase than E. coli BL21(DE3)pLysS. The His(6)-tagged Pwo dUTPase was purified on Ni(2+)-IDA-Sepharose, dialyzed, and the enzyme activity was investigated. We found that His(6)-tag domain has no influence on dUTP hydrolytic activity. dUTP is generated during PCR from dCTP, which inhibits the polymerization of DNA catalyzed by DNA polymerase with 3(')-5(') exonuclease activity. We observed that the thermostable His(6)-tagged Pwo dUTPase used for the polymerase chain reaction with P. woesei DNA polymerase improves the efficiency of PCR and it allows for amplification of longer targets.     

Circadian gene methylation in rotating-shift nurses: a cross-sectional study

Investigating the methylation status of the circadian genes may contribute to a better understanding of the shift work-related circadian disruption in individuals exposed to artificial light at night. In the present study, we determined the methylation status of the circadian genes associated with a shift work pattern among nurses and midwives participating in a cross-sectional study in Lodz, Poland.

Quantitative methylation polymerase chain reaction assays were used to assess promoter CpG methylation in PER1, PER2, PER3, CRY1, CRY2, BMAL1, CLOCK, and NPAS2 in genomic DNA from whole blood of 347 women having a rotating-shift work schedule and 363 women working days only. The percentage of methylated reference (PMR) was assessed using fluorescent probes for PER1, PER2, PER3, CRY1, and NPAS2, and the percentage of gene methylation, as the methylation index (MI), using two sets of primers for BMAL1, CLOCK, and CRY2.

We tested the possible association between current and lifetime rotating night-shift work characteristics and circadian gene methylation by using proportional odds regression model with blood DNA methylation, categorized into tertiles, and adjusted for age, current smoking status, folate intake and blood collection time. The findings indicated that CpG methylation in PER2 promoter was significantly decreased (P < 0.004) among nurses and midwives currently working rotating shifts, as compared with day-working nurses and midwives. The lower percentage of PER2 methylation was associated with a higher monthly frequency of current night duties (2–7 night shifts, and eight or more night shifts per month) (P = 0.012) and was associated at borderline significance (P = 0.092) with the lifetime duration of shift work (>10 ≤ 20 years and >20 ≤ 43 years of rotating-shift work) among nurses and midwives (N = 710). Moreover, women with a longer lifetime duration of shift work presented a lower status of PER1 methylation (P = 0.040) than did the women with up to 10 years of rotating-shift work. Long lifetime duration of shift work (> 10 years) among current rotating night-shift workers (N = 347) was associated with BMAL1 hypomethylation (P = 0.013).

Among eight of the investigated circadian genes, only PER1, PER2, and BMAL1 showed differential methylation attributable to the rotating-shift work of nurses and midwives. The findings on blood-based DNA methylation in the circadian genes may provide a better insight into the mechanistic principles underlying the possible health effects of night-shift work but these should be verified in further studies recruiting larger populations of shift workers.     

Identification of antitumour activity of novel derivatives of 8-aryl-2,6,7,8-tetrahydroimidazo[2,1-c][1,2,4]triazine-3,4-dione and 8-aryl-4-imino-2,3,7,8-tetrahydroimidazo[2,1-c][1,2,4]triazin-3(6H)-one

The series of 8-aryl-2,6,7,8-tetrahydroimidazo[2,1-c][1,2,4]triazine-3,4-diones (11-20) and 8-aryl-4-imino-2,3,7,8-tetrahydroimidazo[2,1-c][1,2,4]triazin-3(6H)-ones (21-25) were designed and their in vitro cytotoxic activities against human LS180, HeLa, T47D, A549 and RPMI 8226 carcinoma cells are presented. In the crystalline state molecule 12 exists as the predominant tautomeric 3-oxo form, whereas the second possible 3-hydroxy tautomer is not observed. Compound 19 revealed a strong affection to LS180 cancer cells at lower tested concentration (37.9 microM) and simultaneously was found to be non-toxic towards the normal cell line investigated--GMK cells. Furthermore, this compound was proved to possess the efficiency for DNA strand breakage of the examined cancer cell lines. However, imidazotriazin-3,4-dione 20 was able to cause significant viability decreases in human RPMI 8226 peripheral blood myeloma cells. Compound 22 has exhibited remarkable inhibitory effects against LS180 and A549 carcinoma cells, whereas 24 revealed the highest growth inhibition against A549 cell line. Simultaneously, at lower tested concentration these compounds were proved to be completely non-toxic for GMK cells. Moreover, cytotoxic and antibacterial properties of starting, tautomeric 1-aryl-2-hydrazonoimidazolidines (1-6 and 8-9) are presented. Six of them (1-2, 4-6 and 9) proved active as antimicrobials. All these compounds revealed MIC values in the range of 15.0-78.6 microM. Their activities were compared to those of ampicillin and chloramphenicol.     

Temperature Sensitivity Conferred by ligA Alleles from Psychrophilic Bacteria upon Substitution in Mesophilic Bacteria and a Yeast Species

We have assembled a collection of 13 psychrophilic ligA alleles that can serve as genetic elements for engineering mesophiles to a temperature-sensitive (TS) phenotype. When these ligA alleles were substituted into Francisella novicida, they conferred a TS phenotype with restrictive temperatures between 33 and 39°C. When the F. novicidaligA hybrid strains were plated above their restrictive temperatures, eight of them generated temperature-resistant variants. For two alleles, the mutations that led to temperature resistance clustered near the 5′ end of the gene, and the mutations increased the predicted strength of the ribosome binding site at least 3-fold. Four F. novicida ligA hybrid strains generated no temperature-resistant variants at a detectable level. These results suggest that multiple mutations are needed to create temperature-resistant variants of these ligA gene products. One ligA allele was isolated from a Colwellia species that has a maximal growth temperature of 12°C, and this allele supported growth of F. novicida only as a hybrid between the psychrophilic and the F. novicidaligA genes. However, the full psychrophilic gene alone supported the growth of Salmonella enterica, imparting a restrictive temperature of 27°C. We also tested two ligA alleles from two Pseudoalteromonas strains for their ability to support the viability of a Saccharomyces cerevisiae strain that lacked its essential gene, CDC9, encoding an ATP-dependent DNA ligase. In both cases, the psychrophilic bacterial alleles supported yeast viability and their expression generated TS phenotypes. This collection of ligA alleles should be useful in engineering bacteria, and possibly eukaryotic microbes, to predictable TS phenotypes.