Methane-cycling microbial communities and methane emission in natural and restored peatlands

We addressed how restoration of forestry-drained peatlands affects CH(4)-cycling microbes. Despite similar community compositions, the abundance of methanogens and methanotrophs was lower in restored than in natural sites and correlated with CH(4) emission. Poor establishment of methanogens may thus explain low CH(4) emissions on restored peatlands even 10 to 12 years after restoration.     

Postlabelling HPLC analysis of lipophilic DNA adducts from human lung

A new modification of the 32P postlabelling method was described for the analysis of lipophilic DNA in human tissues. To isolate these DNA adducts the method applied nuclease P1 enrichment before labelling and butanol extraction after labelling, followed by high performance liquid chromatography HPLC separation and flow through radioactivity detection. These enrichment methods are known to work for many adducts of polycyclic aromatic hydrocarbons PAHs . In human peripheral lung tissue fro m smokers the apparent level of the DNA adducts observed was 25-244 adducts per 108 nucelotides; in two alleged non smokers the level of adducts was 17 and 109 adducts per 108 nucleotides. When the same samples were analysed by thin layer chromatography TLC , as in the conventional postlabelling assay, the recovery was 5 of that of the HPLC method. Nevertheless, the results from the two methods correlated. In TLC the adducts were lost because they did not remain in the origin in D1 of the TLC development. There was no large difference in recovery between the two techniques for the PAH-DNA adduct standards used. The present results are underestimates of the true adduct levels because there is no way to correct for labelling efficiency and recovery of unknown adducts. Yet they give a lower estimate of the level of lipophilic DNA adducts in human lung tissue.     

The Activities of Lysyl Hydroxylase 3 (LH3) Regulate the Amount and Oligomerization Status of Adiponectin

Lysyl hydroxylase 3 (LH3) has lysyl hydroxylase, galactosyltransferase, and glucosyltransferase activities, which are sequentially required for the formation of glucosylgalactosyl hydroxylysines in collagens. Here we demonstrate for the first time that LH3 also modifies the lysine residues in the collagenous domain of adiponectin, which has important roles in glucose and lipid metabolism and inflammation. Hydroxylation and, especially, glycosylation of the lysine residues of adiponectin have been shown to be essential for the formation of the more active high molecular weight adiponectin oligomers and thus for its function. In cells that totally lack LH3 enzyme, the galactosylhydroxylysine residues of adiponectin were not glucosylated to glucosylgalactosylhydroxylysine residues and the formation of high and middle molecular weight adiponectin oligomers was impaired. Circulating adiponectin levels in mutant mice lacking the lysyl hydroxylase activity of LH3 were significantly reduced, which indicates that LH3 is required for complete modification of lysine residues in adiponectin and the loss of some of the glycosylated hydroxylysine residues severely affects the secretion of adiponectin. LH mutant mice with reduced adiponectin level showed a high fat diet-induced increase in glucose, triglyceride, and LDL-cholesterol levels, hallmarks of the metabolic syndrome in humans. Our results reveal the first indication that LH3 is an important regulator of adiponectin biosynthesis, secretion and activity and thus might be a potential candidate for therapeutic applications in diseases associated with obesity and insulin resistance.     

Hydrophilic compounds in liquids of enzymatic hydrolyzed spruce and pine biomass

This study was focused on organic acids and metals in biofluids of wood. Without seasoning, fresh woods from spruce and bark, phloem, and heartwood from pine were used as materials, which were degraded with either microbes of oyster mushroom, baker’s yeast, or lactic acid bacteria. Due to neutral pH of the fluids, ambient temperature, atmospheric pressure, and short reaction time, native wood microbe populations were supposed to be present. The water content of the fresh woods was 4 to 20%. The study showed that process methodology and experimental conditions affected the generation of lactic, citric, succinic, and adipic acids, which are considered as source chemicals in the biopolymer industry. In addition to the organic acids and metals, the process produced monosaccharides, polysaccharides, and phenolic acids such as benzoic, salicylic, cinnamic, vanillic, tannic, and conifer (ferulic) acids. Concentrations of total acids and acetic and succinic acids in pine fluids from bark, phloem, and heartwood were 58.4 g/kg and 3.5 to 6.9 g/kg, respectively. In spruce, the most dominant acids were l-lactic and l-malic acids. As for metals, Ag and Cr were detected at 0.01-g/kg quantities in pine bark. Alkali metals K, Mg, Sr, and Ca were detected at 10, 8, 1.3, and 4 g/kg, respectively.     

Effect of Willow Tit Poecile montanus alarm calls on attack rates by Pygmy Owls Glaucidium passerinum

One suggested anti‐predator function of alarm calls is to deliver a message to a predator that it has been detected. Moreover, giving the alarm call could provide a signal to the predator that capturing the individual giving the alarm is more difficult than capturing its silent group members, as the caller is probably the most aware of the predator's location. In an aviary experiment using stuffed dummy Willow Tits Poecile montanus, we assessed whether an authentic alarm call given by Willow Tit affected Pygmy Owl Glaucidium passerinum prey preference. In the experiment, the Owls attacked only the ‘silent’ dummy individuals, suggesting that alarm calling could offer direct fitness benefits to the caller by decreasing the attack risk of the caller relative to its group members.     

Electrocatalytic oxidation and determination of deferasirox and deferiprone on a nickel oxyhydroxide-modified electrode

The electrocatalytic oxidation of two orally administered iron chelator drugs (deferiprone, CP20, and deferasirox, ICL670) was investigated on a nickel oxyhydroxide-modified nickel electrode in alkaline solution. The oxidation process involved and its kinetics were investigated using cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy techniques, as well as steady-state polarization measurements. Voltammetric studies indicated that in the presence of the drugs under study, the anodic peak current of low-valence nickel species increased, followed by a decrease in the corresponding cathodic current. This result indicates that the drugs were oxidized via oxyhydroxide species immobilized on the electrode surface via an EC' mechanism. A mechanism based on the electrochemical generation of Ni(III) active sites and their subsequent consumption by the drugs in question was also investigated. The corresponding rate law under the control of charge transfer was developed, and kinetic parameters were derived. In this context, the charge-transfer resistance accessible both theoretically and through impedancemetry was used as a criterion. The rate constants of the catalytic oxidation of the drugs and the electron-transfer coefficients are reported. A sensitive, simple, and time-saving amperometric procedure was developed for the analysis of deferasirox and deferiprone, with detection limits of 28 and 19 microM, respectively. The electrode was used for the direct assay of deferasirox and deferiprone tablets.     

Evaluation of the Validity of Job Exposure Matrix for Psychosocial Factors at Work

Objective

To study the performance of a developed job exposure matrix (JEM) for the assessment of psychosocial factors at work in terms of accuracy, possible misclassification bias and predictive ability to detect known associations with depression and low back pain (LBP).

Materials and Methods

We utilized two large population surveys (the Health 2000 Study and the Finnish Work and Health Surveys), one to construct the JEM and another to test matrix performance. In the first study, information on job demands, job control, monotonous work and social support at work was collected via face-to-face interviews. Job strain was operationalized based on job demands and job control using quadrant approach. In the second study, the sensitivity and specificity were estimated applying a Bayesian approach. The magnitude of misclassification error was examined by calculating the biased odds ratios as a function of the sensitivity and specificity of the JEM and fixed true prevalence and odds ratios. Finally, we adjusted for misclassification error the observed associations between JEM measures and selected health outcomes.

Results

The matrix showed a good accuracy for job control and job strain, while its performance for other exposures was relatively low. Without correction for exposure misclassification, the JEM was able to detect the association between job strain and depression in men and between monotonous work and LBP in both genders.

Conclusions

Our results suggest that JEM more accurately identifies occupations with low control and high strain than those with high demands or low social support. Overall, the present JEM is a useful source of job-level psychosocial exposures in epidemiological studies lacking individual-level exposure information. Furthermore, we showed the applicability of a Bayesian approach in the evaluation of the performance of the JEM in a situation where, in practice, no gold standard of exposure assessment exists.     

Capillary electrophoresis with UV detection and mass spectrometry in method development for profiling metabolites of steroid hormone metabolism

The aim of this study was to develop a method for comprehensive profiling of metabolites involved in mammalian steroid metabolism. The study was performed using the partial filling micellar electrokinetic chromatography (PF-MEKC) technique for determination of endogenous low-hydrophilic steroids. The detection techniques in capillary electrophoresis were UV absorption and electrospray mass spectrometry (ESI-MS). Thirteen steroids were included in the method development, and the selected were metabolites involved in major pathways of steroid biosynthesis. Although only eight of them could be separated and detected with UV, they could be identified by ESI-MS using selected ion monitoring (SIM) technique. Tandem MS spectra were also collected. UV detection was more sensitive than MS due to better separation of compounds and the selective signal sensitivity. The lowest limits of detection were 10-100ng/mL for cortisone, corticosterone, hydrocortisone and testosterone. The other steroids could be detected at 500-1000ng/mL. The identification of cortisone, corticosterone, hydrocortisone, estrogen and testosterone were made in patient urine samples and their concentrations were 1-40mug/L.