Differential impacts of long-term (CO<Subscript>2</Subscript>) and O<Subscript>3</Subscript> exposure on growth of northern conifer and deciduous tree species

The long-term effects of elevated CO₂ and CO₂+O₃ concentrations on the growth allocation in northern provenances of Norway spruce [Picea abies (L.) Karst.], Scots pine [Pinus sylvestris (L.)] and pubescent birch clones (Betula pubescens Ehrh.) were examined in open-top chambers after a 4-year-long experiment. The total biomass responses of the tree seedlings to increased CO₂ and CO₂+O₃ concentrations were not statistically significant and varied between the provenances and species. The seedlings of northern origin were the least sensitive in their response to treatments. The total biomass of the Norway spruce seedlings slightly decreased in response to CO₂ in three provenances. Scots pine from the local provenance had a slight biomass increase after elevated CO₂+O₃ treatment. The slower-growing birch clone seemed to benefit from elevated CO₂, whereas in the faster-growing clone, reductions in biomass accumulation were seen. The combined CO₂+O₃ treatment reduced the positive effects of elevated CO₂, especially in the slower-growing birches. Observations of significant effects were limited to a few parameters. Carbon dioxide treatment decreased needle dry weight of Norway spruce in one northern provenance. The needle and wood dry weight increased (CO₂ + O₃) in local Scots pine. Significant birch response was limited to increased fine root density (O₃ + CO₂) in the inland clone. The diverse effects of elevated CO₂ and CO₂ +O₃ on seedling growth and biomass provide evidence that exposure of northern trees to the enhanced variable CO₂ and O₃ concentrations of the future will have varied effects on the growth of these species. The direction and magnitude of those effects will differ depending on species and origins.     

Tracing and interpreting fine-scale human impact in northern Fennoscandia with the aid of modern pollen analogues

A set of moss samples (n=58) was collected and analysed to obtain modern pollen analogues for both natural and human induced vegetation types in northern Fennoscandia. Vegetation types with settlement, trampling and grazing were selected from the different latitudinal forest zones (birch, pine, and mixed forest). The moss species varied between samples but the size of the sample was kept constant. Numerical analyses such as Redundancy Analysis (RDA) indicate that in northern areas human presence is mainly visible as increased values of Gramineae, Rumex acetosa/acetosella, R. obtusifolius, Solidago-type and Achillea-type pollen. Partial RDA further reveals that settlement is strongly correlated with high values of Rumex acetosa/acetosella, whereas trampled sites are significantly characterised by Gramineae and, to a smaller extent, Cyperaceae pollen. It is therefore possible to distinguish the impact of different types of human activities on vegetation on the basis of the pollen spectra. Later, these data will be used to interpret the presence, nature, and duration of human impact from fossil records from the same area. Received June 6, 2001 / Accepted December 12, 2001     

Interaction of exercise and adenosine receptor agonist and antagonist on rat heart antioxidant defense system

This study investigated the interactive effects of acute exercise and adenosine receptor agonist and antagonist on antioxidant enzyme activities, glutathione and lipid peroxidation in the heart of the rat. Male Fisher-344 rats were divided into six groups and treated as follows: (1) saline control; (2) acute exercise (100% VO_2max); (3) R-Phenyl isopropyl adenosine (R-PIA) (3.46 mol/kg, i.p.); (4) theophylline (1.70 mol/kg, i.p.) plus acute exercise; (5) theophylline plus R-PIA; and (6) theophylline. Animals were sacrificed 1 h after treatments; hearts were isolated and analyzed. The results show that acute exercise as well as adenosine receptor agonist R-PIA significantly enhanced cardiac superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and glutathione reductase (GR) activity by 36–135% and 16–51%, respectively. Adenosine receptor agonist R-PIA significantly decreased cardiac GSSG concentration and enhanced GSH/GSSG ratio by 22 and 30%, respectively. Whereas theophylline treatment blocked the activation of antioxidant enzyme activities enhanced by acute exercise and R-PIA. Theophylline treatment significantly increased lipid peroxidation by 43% in the heart of exercised rats. The study concluded that the adenosine receptors are involved in the upregulation of cardiac antioxidant defense system and attenuation of lipid peroxidation due to acute exercise in rats. (Mol Cell Biochem 270: 209–214, 2005)     

Delineation of Cohen syndrome following a large-scale genotype-phenotype screen

Cohen syndrome is an autosomal recessive condition associated with developmental delay, facial dysmorphism, pigmentary retinopathy, and neutropenia. The pleiotropic phenotype, combined with insufficient clinical data, often leads to an erroneous diagnosis and has led to confusion in the literature. Here, we report the results of a comprehensive genotype-phenotype study on the largest cohort of patients with Cohen syndrome assembled to date. We found 22 different COH1 mutations, of which 19 are novel, in probands identified by our diagnostic criteria. In addition, we identified another three novel mutations in patients with incomplete clinical data. By contrast, no COH1 mutations were found in patients with a provisional diagnosis of Cohen syndrome who did not fulfill the diagnostic criteria ("Cohen-like" syndrome). This study provides a molecular confirmation of the clinical phenotype associated with Cohen syndrome and provides a basis for laboratory screening that will be valuable in its diagnosis.     

Cost of reproduction in Callosobruchus maculatus: effects of mating on male longevity and the effect of male mating status on female longevity

One of the most studied life-history trade-offs is that resulting from the cost of reproduction: a trade-off arises when reproduction diverts limited resources from other life-history traits. We examine the cost of reproduction in male, and the effect of male mating status on female Callosobruchus maculatus seed beetles. Cost of reproduction for male C. maculatus was manifested as reduced longevity. There was also a positive relationship between male body size and male longevity. Females mated to males that had already copulated twice did not live as long as females mated to males that had copulated once or not at all. The third copulation of males also lasted longer than the two previous ones. We conclude that even though the cost of reproduction for males has been studied much less than that in females, there is growing evidence that male reproductive effort is more complex than has traditionally been thought.     

Metal ion complexes of macrocyclic polyamines enhance both the phosphate hydrolysis and imidazole ring opening of RNA 5'-cap structure

The cleavage of P1-(7-methylguanosyl-5') P3-(guanosyl-5') triphosphate, a RNA 5'-cap model, by 2-hydroxyethyl- (6a-6c) and 2-aminoethyl- (7a-7c) substituted macrocycles in the presence and absence of Zn2+ and Cu2+ ions has been studied at pH 7.2 and 60 degrees. In the presence of the metal ions, hydrolysis of the phosphate group is enhanced. The mono- and dinuclear Zn2+ complexes promote solely the phosphate hydrolysis, whereas the corresponding Cu2+ complexes accelerate both the phosphate hydrolysis and the imidazole ring opening of the 7-methylguanine base. In the absence of the metal ions, the macrocycles mainly promote breakdown of the 7-methylguanine base, most probably by enhancing the nucleophilic attack of hydroxide ion on the C(8)-atom by shielding the repulsive negative charge on the phosphate moiety. The 2-hydroxyethyl and 2-aminoethyl side arms exhibit a two- to three-fold rate acceleration. Opening of the imidazole ring eventually results in cleavage of the triphosphate bridge.     

Fishing-induced changes in predation pressure by perch (<Emphasis Type="Italic">Perca fluviatilis</Emphasis>) regulate littoral benthic macroinvertebrate biomass,density, and community structure

We aimed to study whether the varying changes in predation pressure by perch (Perca fluviatilis) reflect the biomass, density, and community structure of the benthic macroinvertebrates. Prey preference is size-dependent, and overall predation pressure is density dependent, and thus the size structure of the P. fluviatilis population should affect the structure of the macroinvertebrate community, and the population density of P. fluviatilis should reflect the overall density of benthic macroinvertebrates. We sampled the littoral benthic community in a boreal lake that had been divided into two parts that were subjected to two different fishing procedures during 2007–2012 period and analyzed the macroinvertebrate diet of fish. The benthic macroinvertebrate community reflected the predation pressure. Total macroinvertebrate biomass increased during the study period in the lake division with a non-size-selective fishing procedure (NSF), i.e., all invertivorous perch size-classes targeted, but decreased in the section with negatively size-selective fishing procedure (SSF), i.e., large invertivorous individuals ≥ 16 cm were not targeted. This difference was a result of the increase in large-sized species, such as Odonata, for the NSF procedure and decrease in the SSF procedure. In contrast to total biomass, total macroinvertebrate density did not show a response to predator size structure but rather total macroinvertebrate density decreased with increasing fish density. The study demonstrates the effect of predation pressure of P. fluviatilis on benthic communities, thus highlighting the keystone predator role of the species in boreal lakes and gives more insight on the multiple effects of fish predation on littoral benthic communities.     

Immune cell phenotype and functional defects in Netherton syndrome

Background

Netherton syndrome (NS) is a rare life-threatening syndrome caused by SPINK5 mutations leading to a skin barrier defect and a severe atopic diathesis. NS patients are prone to bacterial infections, but the understanding of the underlying immune deficiency is incomplete.

Results

We analyzed blood lymphocyte phenotypes and function in relation to clinical infections in 11 Finnish NS patients, aged 3 to 17?years, and healthy age-matched controls. The proportion of B cells (CD19⁺) and naïve B cells (CD27^?, IgD⁺) were high while memory B cells (CD27⁺) and switched memory B cells (CD27⁺IgM^?IgD^?), crucial for the secondary response to pathogens, was below or in the lowest quartile of the reference values in 8/11 (73%) and 9/11 (82%) patients, respectively. The proportion of activated non-differentiated B cells (CD21^low, CD38l^ow) was below or in the lowest quartile of the reference values in 10/11 (91%) patients. Despite normal T cell counts, the proportion of naïve CD4⁺ T cells was reduced significantly and the proportion of CD8⁺ T central memory significantly elevated. An increased proportion of CD57⁺ CD8⁺ T cells indicated increased differentiation potential of the T cells. The proportion of cytotoxic NK cells was elevated in NS patients in phenotypic analysis based on CD56DIM, CD16⁺ and CD27^? NK cells but in functional analysis, decreased expression of CD107a/b indicated impaired cytotoxicity.The T and NK cell phenotype seen in NS patients also significantly differed from that of age-matched atopic dermatitis (AD) patients, indicating a distinctive profile in NS. The frequency of skin infections correlated with the proportion of CD62L⁺ T cells, naïve CD4⁺ and CD27⁺ CD8⁺ T cells and with activated B cells. Clinically beneficial intravenous immunoglobulin therapy (IVIG) increased naïve T cells and terminal differentiated effector memory CD8⁺ cells and decreased the proportion of activated B cells and plasmablasts in three patients studied.

Conclusions

This study shows novel quantitative and functional aberrations in several lymphocyte subpopulations, which correlate with the frequency of infections in patients with Netherton syndrome. IVIG therapy normalized some dysbalancies and was clinically beneficial.