Health and Masculinities Shaped by Agency within Structures among Young Unemployed Men in a Northern Swedish Context

AimThe aim of our paper was to explore expressions of life choices and life chances (aspects of agency within structures) related to power and experiences of health among early unemployed adolescent young men during the transition period to adulthood. These expressions of agency within structure were interpreted in the light of Cockerham’s Health Lifestyles Theory. Furthermore, social constructions of masculinities were addressed in our analysis.MethodsRepeated interviews with ten young men in a cohort of school leavers were analyzed with qualitative content analysis.ConclusionsQualitative research could contribute to develop the understanding of the agency within structure relationships. Future studies need to pay attention to experiences of health among young people at the margin of the labor market in various milieus – and to analyze these in relation to gender constructions and within the frame-work of agency within structure.     

Interleukin-4 activates ion channels in B lymphocytes.

The lymphokine interleukin-4 (IL-4) has been shown to induce dramatic changes in the physiology of resting B cells. We have applied the patch clamp technique in the cell attached and inside/out configurations to resting and IL-4-treated B cells to determine whether specific ion conductances result as a consequence of IL-4 action. We report here that two distinct ion channel events occur in B lymphocytes after treatment with IL-4, (i) induction of an inward rectifying K+ channel that is not observed in untreated cells, and (ii) activation of a large conductance anion channel that is normally silent in non-treated cells in the cell attached patch configuration. These data present the first evidence of a direct effect by IL-4 on ion channels and we suggest roles for these two ionic conductances in IL-4-induced B cell activation.     

A Nuclear Marker for Mammalian Cells and Its Use with Intracerebral Transplants

The Hoechst dye staining method has been successfully applied to the central nervous system in mammals and its use has been demonstrated in intracerebral transplantation. The technique is rapid, simple and based on intrinsic nuclear properties. It was found to be permanent and valid whatever the animal strains or ages, allowing the distinction of rat cells from those of mouse, studied either separately or in a cross-transplantation model. It permitted the detection of grafted cells in the area of transplantation and the observation of early dispersion around the implantation site. Moreover, it can be combined with immunohistochemistry as demonstrated by a myelin marker in a relevant model. Immunodetection can thus help to directly observe grafted cells, at distance from the locus of transplantation, confirming their presence in the graft-type myelin patches.

Because of its rapid performance, this technique can be used systematically after transplantation to check for the presence of grafted cells in the host.     

Molecular modelling of protein-carbohydrate interactions. Understanding the specificities of two legume lectins towards oligosaccharides

By means of a series of new molecular modelling tools, the conformationalbehaviour of mannose-containing di- and trisaccharides boundto either concanavalin A or Lathyrus ochrus isolectin I (LOLI)has been assessed. Tools for estimating and analysing eitherthe ‘rigid’ or the ‘relaxed’ potentialenergy surfaces, representing the conformational space availablefor carbohydrates once interacting with lectins, are reportedfor the first time. Restrictions of conformational space arepredicted to occur with different magnitudes, depending on thenature of the glycosidic linkages, as well as the size of thecarbohydrates. Results from these molecular modelling studiesare compared to existing structural data. Not only could theobserved conformations and orientations of carbohydrates incrystalline lectin–oligosaccharides complexes be reproduced,but several other likely situations were also predicted to occur.Entropy calculations have been performed for comparison withexperimental thermodynamics data. The results of the simulationcan also help giving an explanation of some observed affinityconstants at the molecular level. concanavalin A Lathyrus ochrus lectin-oligosaccharide molecular modelling     

Membrane-associated hyaluronate-binding activity of chondrosarcoma chondrocytes

The association of hyaluronate with the surface of chondrocytes was examined by several approaches using primary cultures of chondrocytes derived from the Swarm rat chondrosarcoma. In culture, chondrosarcoma chondrocytes produced large pericellular coats, which can be visualized by particle exclusion, and which can be removed by Streptomyces hyaluronidase. Exposure of chondrocytes, which had been metabolically labelled with 3H-acetate, to exogenous hyaluronate or to Streptomyces hyaluronidase resulted in the release of 36-38% of the endogenous, labelled chondroitin sulfate from the cell layer into the incubation solution. These results imply that at least 37% of the cell layer chondroitin sulfate proteoglycan is retained there by an interaction with hyaluronate. Thus membranes were prepared from cultured chondrocytes and examined for sites which bind 3H-hyaluronate. Binding was observed and found to be saturable, specific for hyaluronate, of high affinity (Kd = approximately 10(-10) M), and destroyed by treating the membranes with trypsin. The 3H-hyaluronate-binding activity was inhibited competitively by hyaluronate decasaccharides but not by hexasaccharides or octasaccharides, indicating that the binding sites recognize a sequence of hyaluronate composed of five disaccharide repeats. The binding activity was partially purified from a detergent extract of chondrocyte membranes by ion exchange chromatography on DEAE-cellulose, followed by affinity chromatography on wheat germ agglutinin-agarose. Analysis of the partially purified binding activity by SDS-PAGE revealed five protein bands of 48,000-66,000 daltons in silver-stained gels. SDS-PAGE followed by Western blotting and exposure to monoclonal antibodies which recognize epitopes present in link protein and in the hyaluronate-binding region of cartilage proteoglycan revealed no immunoreactive protein bands in the partially purified material. We conclude that one mechanism by which hyaluronate associates with the chondrocyte surface may be via interaction with a membrane-bound hyaluronate-binding protein which is distinct from link protein and proteoglycan.     

Multi-year sampling provides insight into the bet-hedging capacity of the soil-stored seed reserve of a threatened Acacia species from Western Australia

This multi-year study examined temperature requirements for dormancy release in physically dormant seeds of the threatened legume Acacia awestoniana (Fabaceae) from Western Australia. Seeds were collected from a single site in three consecutive years and exposed to multiple laboratory-based ‘fire’-related temperature treatments (intensity × duration). Experiments were conducted on seeds freshly collected and after 12 months storage under dry laboratory conditions in order to separate the influence of the maternal environment from post-harvest storage conditions on thresholds for dormancy release. Initial seed viability and non-dormant seed fraction did not differ between seed cohorts but there was a clear effect of storage on seed response: fresh seeds from 2016 demonstrated greater thermal resilience than stored seeds collected in the same year. Equally, there was a strong inter-annual response to treatments from fresh seeds collected in 2016 and 2017 attributed to the influence of the maternal environment during seed development. Seeds collected in 2015 and 2016 and stored for 12 months also demonstrated significant differences in their response to treatments, with 2015 seeds responding more favourably to treatment conditions than those from 2016. Plastic responses to external stimuli provide seeds with a strong bet-hedging capacity and the potential to cope with high levels of environmental heterogeneity, especially a mosaic of fire conditions. Such data provide insight for the management, conservation and restoration of this and similar threatened plant species in fire-prone ecosystems in the face of a rapidly changing climate and expected associated changes in the fire regime.