The Relationship between Parental Depressive Symptoms,Family Type,and Adolescent Functioning

It is evident that parental depressive symptoms negatively influence adolescent behavior and various psychosocial outcomes. Certain family types like families with a chronically ill parent and single parent families are more vulnerable to parental depressive symptoms. However, the relationship between these symptoms, family type, and adolescent functioning remains largely unclear. This study examined relations between self-report of parental depressive symptoms and adolescent functioning in 86 two-parent families including a parent with a chronic medical condition, 94 families with healthy single parents, and 69 families with 2 healthy parents (comparison group). Parents completed the Beck Depression Inventory. Adolescents filled in the Youth Self-Report measuring problem behavior, and other instruments measuring psychosocial outcomes (stress, grade point average, school problems, and self-esteem). Multilevel analyses were used to examine the effects of family type, parental depressive symptoms, adolescents'' gender and age, and interaction effects on adolescent functioning. The results indicated that adolescents with chronically ill and single parents had a lower grade point average (p<.01) than the comparison group. Adolescents of single parents reported more internalizing problems (p<.01) and externalizing problems (p<.05) than children from the other family types. Parental depressive symptoms were strongly related to child report of stress (p<.001). Adolescents of depressed chronically ill parents were particularly vulnerable to internalizing problems (interaction effect, p<.05). Older children and girls, and especially older girls, displayed more internalizing problems and stress. It can be concluded that growing up with a chronically ill parent in a family with 2 parents may have less impact on adolescent problem behavior than growing up in a single parent family. Health practitioners are encouraged to be attentive to the unique and combined influence of family type and parental depressive symptoms on adolescent functioning. Older and female adolescents deserve particular attention.     

In vivo analysis of proteomes and interactomes using Parallel Affinity Capture (iPAC) coupled to mass spectrometry

Affinity purification coupled to mass spectrometry provides a reliable method for identifying proteins and their binding partners. In this study we have used Drosophila melanogaster proteins triple tagged with Flag, Strep II, and Yellow fluorescent protein in vivo within affinity pull-down experiments and isolated these proteins in their native complexes from embryos. We describe a pipeline for determining interactomes by Parallel Affinity Capture (iPAC) and show its use by identifying partners of several protein baits with a range of sizes and subcellular locations. This purification protocol employs the different tags in parallel and involves detailed comparison of resulting mass spectrometry data sets, ensuring the interaction lists achieved are of high confidence. We show that this approach identifies known interactors of bait proteins as well as novel interaction partners by comparing data achieved with published interaction data sets. The high confidence in vivo protein data sets presented here add new data to the currently incomplete D. melanogaster interactome. Additionally we report contaminant proteins that are persistent with affinity purifications irrespective of the tagged bait.     

Transgenic rice as a novel production system for <Emphasis Type="Italic">Melanocarpus</Emphasis> and <Emphasis Type="Italic">Pycnoporus</Emphasis> laccases

Laccases have numerous biotechnological applications, among them food processing. The widespread use of laccases has increased the demand for an inexpensive and safe source of recombinant enzyme. We explored the use of a rice-based system for the production of two fungal laccases derived from the ascomycete Melanocarpus albomyces and the basidiomycete Pycnoporus cinnabarinus. High-expression levels of active recombinant laccases were achieved by targeting expression to the endosperm of rice seeds. The laccase cDNAs were fused to a plant-derived signal sequence for targeting to the secretory pathway, and placed under the control of a constitutive seed-specific promoter fused to an intron for enhanced expression. This construct enabled the recovery of on average 0.1-1% of soluble laccase in total soluble proteins (TSP). The highest yields of recombinant laccases obtained in rice seeds were 13 and 39 ppm for riceMaL and ricePycL, respectively. The rice-produced laccases were purified and characterized. The wild-type and the recombinant proteins showed similar biochemical features in terms of molecular mass, pI, temperature and optimal pH and the N-terminus was correctly processed. Although presenting lower kinetic parameters, the rice-produced laccases were also suitable for the oxidative cross-linking of a food model substrate [maize-bran feruloylated arabinoxylans (AX)].     

Variation in predator species abundance can cause variable selection pressure on warning signaling prey

Predation pressure is expected to drive visual warning signals to evolve toward conspicuousness. However, coloration of defended species varies tremendously and can at certain instances be considered as more camouflaged rather than conspicuous. Recent theoretical studies suggest that the variation in signal conspicuousness can be caused by variation (within or between species) in predators' willingness to attack defended prey or by the broadness of the predators' signal generalization. If some of the predator species are capable of coping with the secondary defenses of their prey, selection can favor reduced prey signal conspicuousness via reduced detectability or recognition. In this study, we combine data collected during three large-scale field experiments to assess whether variation in avian predator species (red kite, black kite, common buzzard, short-toed eagle, and booted eagle) affects the predation pressure on warningly and non-warningly colored artificial snakes. Predation pressure varied among locations and interestingly, if common buzzards were abundant, there were disadvantages to snakes possessing warning signaling. Our results indicate that predator community can have important consequences on the evolution of warning signals. Predators that ignore the warning signal and defense can be the key for the maintenance of variation in warning signal architecture and maintenance of inconspicuous signaling.     

Probiotic Bacteria May Become Dormant during Storage

The determination of bacterial viability in probiotic products is of economic, technological, and clinical significance. We compared four methods to enumerate three Bifidobacterium strains in fermented oat products during storage. A subpopulation of nonculturable cells retained a functional cell membrane typical of viable cells, indicating that probiotic bacteria become dormant during storage.     

SCCmec in staphylococci: genes on the move

Staphylococcal cassette chromosome (SCC) elements are, so far, the only vectors described for the mecA gene encoding methicillin resistance in staphylococci. SCCmec elements are classified according to the type of recombinase they carry and their general genetic composition. SCCmec types I-V have been described, and SCC elements lacking mecA have also been reported. In this review, we summarize the current knowledge about SCC structure and distribution, including genetic variants and rudiments of the elements. Its origin is still unknown, but one assumes that staphylococcal cassette chromosome is transferred between staphylococci, and mecA-positive coagulase-negative staphylococci may be a potential reservoir for these elements. Staphylococcal genomes seem to change continuously as genetic elements move in and out, but no mechanism of transfer has been found responsible for moving SCC elements between different staphylococcal species. Observations suggesting de novo production of methicillin-resistant staphylococci and horizontal gene transfer of SCCmec will be discussed.     

Influence of nutrient status and grazing pressure on the fate of Francisella tularensis in lake water

The natural reservoir of Francisella tularensis , the causative agent of tularaemia, is yet to be identified. We investigated the possibility that Francisella persists in natural aquatic ecosystems between outbreaks. It was hypothesized that nutrient-rich environments, with strong protozoan predation, favour the occurrence of the tularaemia bacterium. To investigate the differences in adaptation to aquatic environments of the species and subspecies of Francisella , we screened 23 strains for their ability to survive grazing by the ciliate Tetrahymena pyriformis . All the Francisella strains tested were consumed at a low rate, although significant differences between subspecies were found. The survival and virulence of gfp -labelled F. tularensis ssp. holarctica were then studied in a microcosm experiment using natural lake water, with varying food web complexities and nutrient availabilities. High nutrient conditions in combination with high abundances of nanoflagellates were found to favour F. tularensis ssp. holarctica . The bacterium was observed both free-living and within the cells of a nanoflagellate. Francisella tularensis entered a viable but nonculturable state during the microcosm experiment. When studied over a longer period of time, F. tularensis ssp. holarctica survived in the lake water, but loss of virulence was not prevented by either high nutrient availability or the presence of predators.     

In brown adipocytes,adrenergically induced β1-/β3-(Gs)-, α2-(Gi)- and α1-(Gq)-signalling to Erk1/2 activation is not mediated via EGF receptor transactivation

Brown adipose tissue is unusual in that the neurotransmitter norepinephrine influences cell destiny in ways generally associated with effects of classical growth factors: regulation of cell proliferation, of apoptosis, and progression of differentiation. The norepinephrine effects are mediated through G-protein-coupled receptors; further mediation of such stimulation to e.g. Erk1/2 activation is in cell biology in general accepted to occur through transactivation of the EGF receptor (by external or internal pathways). We have examined here the significance of such transactivation in brown adipocytes. Stimulation of mature brown adipocytes with cirazoline (α₁-adrenoceptor coupled via G_q), clonidine (α₂ via G_i) or CL316243 (β₃ via G_s) or via β₁-receptors significantly activated Erk1/2. Pretreatment with the EGF receptor kinase inhibitor AG1478 had, remarkably, no significant effect on Erk1/2 activation induced by any of these adrenergic agonists (although it fully abolished EGF-induced Erk1/2 activation), demonstrating absence of EGF receptor-mediated transactivation. Results with brown preadipocytes (cells in more proliferative states) were not qualitatively different. Joint stimulation of all adrenoceptors with norepinephrine did not result in synergism on Erk1/2 activation. AG1478 action on EGF-stimulated Erk1/2 phosphorylation showed a sharp concentration–response relationship (IC₅₀ 0.3 µM); a minor apparent effect of AG1478 on norepinephrine-stimulated Erk1/2 phosphorylation showed nonspecific kinetics, implying caution in interpretation of partial effects of AG1478 as reported in other systems. Transactivation of the EGF receptor is clearly not a universal prerequisite for coupling of G-protein coupled receptors to Erk1/2 signalling cascades.