Adipose triglyceride lipase regulates eicosanoid production in activated human mast cells

Human mast cells (MCs) contain TG-rich cytoplasmic lipid droplets (LDs) with high arachidonic acid (AA) content. Here, we investigated the functional role of adipose TG lipase (ATGL) in TG hydrolysis and the ensuing release of AA as substrate for eicosanoid generation by activated human primary MCs in culture. Silencing of ATGL in MCs by siRNAs induced the accumulation of neutral lipids in LDs. IgE-dependent activation of MCs triggered the secretion of the two major eicosanoids, prostaglandin D2 (PGD2) and leukotriene C4 (LTC4). The immediate release of PGD2 from the activated MCs was solely dependent on cyclooxygenase (COX) 1, while during the delayed phase of lipid mediator production, the inducible COX-2 also contributed to its release. Importantly, when ATGL-silenced MCs were activated, the secretion of both PGD2 and LTC4 was significantly reduced. Interestingly, the inhibitory effect on the release of LTC4 was even more pronounced in ATGL-silenced MCs than in cytosolic phospholipase A₂-silenced MCs. These data show that ATGL hydrolyzes AA-containing TGs present in human MC LDs and define ATGL as a novel regulator of the substrate availability of AA for eicosanoid generation upon MC activation.     

Obesity and labour market success in Finland: The difference between having a high BMI and being fat

This paper examines the relationship between obesity and labour market success in Finland, using various indicators of individual body composition along with body mass index (BMI). Weight, height, fat mass and waist circumference are measured by health professionals. We find that only waist circumference has a negative association with wages for women, whereas no obesity measure is significant in the linear wage models for men. However, all measures of obesity are negatively associated with women's employment probability and fat mass is negatively associated with men's employment probability. We also find that the use of categories for waist circumference and fat mass has a substantial influence on the results. For example, the category for high fat mass is associated with roughly 5.5% lower wages for men. All in all, the results indicate that in the absence of measures of body composition, there is a risk that labour market penalties associated with obesity are measured with bias.     

Juvenile Barn Swallows Hirundo rustica L. from late broods start autumn migration younger,fuel less effectively and show lower return rates than juveniles from early broods

Long‐distance migratory passerines may exhibit different post‐fledging rearing times between their early and late broods due to limited time and energy resources. This could affect the migratory fuelling behaviour, condition and fitness of juvenile birds. We analysed long‐term (13‐year) biometric data (body mass, fat score) on Barn Swallows ringed at the nest and later recaptured during their initial stages of autumn migration. The return rates of early‐ and late‐born juveniles after overwintering in Africa were further compared to estimate their fitness. We found that juveniles from late broods started migrating south on average 11 days younger compared with juveniles from early broods. Body masses of nestlings did not differ between early and late broods, but juveniles from late broods were in better condition after leaving the nest, possibly due to a longer period of parental care. Having started migration, juveniles from late broods were, however, less efficient in accumulating energy than juveniles from early broods. A younger departure age, together with less efficient fuelling of late brood juveniles, may partly explain the 39% lower return probability and hence lower fitness value of late‐brood juveniles. Our study is the first to show that juveniles from the early and late broods exhibit different fuelling behaviour and departure strategies (in terms of age and timing), which may be reflected in the fitness value of offspring.     

Alphavirus Replicase Protein NSP1 Induces Filopodia and Rearrangement of Actin Filaments

Expression of the NSP1 protein of Semliki Forest virus and Sindbis virus in cultured cells induced filopodia-like extensions containing NSP1 but not F actin. The actin stress fibers disappeared, whereas vimentin, keratin, and tubulin networks remained intact. The effects of NSP1 were dependent on its palmitoylation but not on its enzymatic activities and were also observed in virus-infected cells.     

Effect of cellulose physical characteristics, especially the water sorption value, on the efficiency of its hydrolysis catalyzed by free or immobilized cellulase

Cellulase, an enzymatic complex that synergically promotes the degradation of cellulose to glucose and cellobiose, free or adsorbed onto Si/SiO₂ wafers at 60 °C has been employed as catalyst in the hydrolysis of microcrystalline cellulose (Avicel), microcrystalline cellulose pre-treated with hot phosphoric acid (CP), cotton cellulose (CC) and eucalyptus cellulose (EC). The physical characteristics such as index of crystallinity (I_C), degree of polymerization (DP) and water sorption values were determined for all samples. The largest conversion rates of cellulose into the above-mentioned products using free cellulase were observed for samples with the largest water sorption values; conversion rates showed no correlation with either I_C or DP of the biopolymer. Cellulose with large water sorption value possesses large pore volumes, hence higher accessibility. The catalytic efficiency of immobilized cellulase could not be correlated with the physical characteristics of cellulose samples. The hydrolysis rates of the same cellulose samples with immobilized cellulase were lower than those by the free enzyme, due to the diffusion barrier (biopolymer chains approaching to the immobilized enzyme) and less effective contact between the enzyme active site and its substrate. Immobilized cellulase, unlike its free counterpart, can be recycled at least six times without loss of catalytic activity, leading to higher overall cellulose conversion.     

Synthesis of optically active diols using an efficient polymer bound cinchona alkaloid derivative

A new insoluble polymer containing a Cinchona alkaloid derivative has been synthesized and used as chiral ligand in the heterogeneous enantioselective dihydroxylation of olefins. It is shown that the enantioselectivity of the optically active diols obtained from both aliphatic and aromatic substrates is always comparable to that observed in the homogeneous phase under the same reaction conditions. A method for evaluating the enantiomeric excesses of the optically active products is also described. © 1995 Wiley-Liss, Inc.     

Enhanced BDNF Signaling is Associated with an Antidepressant-like Behavioral Response and Changes in Brain Monoamines

1. Neurotrophins and serotonin have both been implicated in the pathophysiology of depression and in the mechanisms of antidepressant treatments. 2. Brain-derived neurotrophic factor (BDNF) influences the growth and plasticity of serotonergic (5-HT) neurons via the activation of trkB receptor. 3. Transgenic mice overexpressing the full-length trkB receptor (TrkB.TK+) and showing increased trkB activity in brain, and their wild type (WT) littermates, were injected with the antidepressant fluoxetine or saline, and analyzed behaviorally in the forced swimming test paradigm and biochemically for the concentrations of brain monoamines and their metabolites. 4. The TrkB.TK+ mice displayed increased latency to immobility in the forced swim test, suggesting resistance to behavioral despair. 5. Fluoxetine increased the latency to immobility in wild-type mice to a similar level as seen in the trkB.TK+ mice after saline treatment, but had no further behavioral effect in the swimming behavior of the trkB.TK+ mice. 6. Only minor differences in the levels of brain monoamines and their metabolites were observed between the transgenic and wild-type mice. 7. These data, together with other recent observations, suggest that trkB activation may play a critical role in the behavioral responses to antidepressant drugs in mice.     

In vitro development of theDrosophila chorion in a chemically defined organ culture medium

Summary TheDrosophila chorion is produced normally in isolated follicles in Robb's chemically defined culture medium. The complex architecture of the shell developed in vitro from follicles as young as early stage 10 is completely normal morphologically. In addition, the time required for in vitro development closely approximates that observed for in vivo development. Comparisons of insect culture media developed by Robb, Grace, Schneider, and Echalier show large variations in their ability to supportDrosophila chorion development.     

萨哈林岛舞蛛属一新种记述

记述了采自萨哈林岛1新种,Alopecosa mikhailovi sp.nov.,2♂♂,新种与solivaga种团近似.