Handgrip-induced airway dilation in asthmatic patients with bronchoconstriction induced by MCh inhalation.

We investigated the effects of static and rhythmic handgrip on the time course of recovery of airway resistance measured with the interrupter technique (Rint) following bronchoconstriction induced by methacholine (MCh) inhalation in 17 asthmatic patients. On three separate occasions, a 100 +/- 5% increase in baseline Rint was induced by MCh inhalation. Subsequently, patients either rested [control trials (CTs)] or performed 3-min bouts of static or rhythmic handgrip. Respiratory and cardiovascular variables were continuously monitored. Rint changes were assessed at 1-min intervals for 30 min after rest and both types of handgrip. Plasma catecholamine concentrations were also determined at scheduled intervals. Bronchoconstriction increased ventilation (P < 0.01) but did not affect cardiovascular variables and plasma catecholamine concentrations. Handgrip provoked an increase in cardiovascular variables (P < 0.01) and plasma norepinephrine concentrations (P < 0.05) but caused no additional changes in ventilation. Rint only partially recovered within 30 min after CTs, whereas it consistently decreased 1 min after both handgrip paradigms and remained lower than after CTs (P always <0.01) for the whole 30-min observation period. Sympathetic activation and withdrawal of cholinergic input to the airway smooth muscle reflexly induced by activation of skeletal muscle and carotid sinus receptors may be the primary events accounting for the bronchodilator response induced by handgrip. Mediators co-released in response to sympathetic activation may also have contributed.     

Enhancement of fruit byproducts through bioconversion by Hermetia illucens (Diptera: Stratiomyidae)

Bioconversion is a biological process by which organic materials are converted into products with higher biological and commercial value. During its larval stage the black soldier fly Hermetia illucens is extremely voracious and can feed on a wide variety of organic materials. To study the impact of different fruit byproducts on the insect's growth, final larval biomass, substrate reduction, bioconversion parameters, and larval nutritional composition, 10 000 black soldier fly larvae (BSFL) were reared on 7.0 kg of one of three substrates (strawberry, tangerine, or orange) or on a standard diet as a control. The results highlight that BSFL can successfully feed and grow on each of these diets, though their development time, growth rate, and final biomass were differently impacted by the substrates, with strawberry being the most suitable. The lipid and protein contents of BSFL were similar among larvae fed on different substrates; however, major differences were detected in ash, micronutrient, fiber, fatty acid, and amino acid contents. Overall, the results indicate that fruit waste management through the BSFL bioconversion process represents a commercially promising resource for regional and national agrifood companies. Our study offers new perspectives for sustainable and environmentally friendly industrial development by which fruit byproducts or waste might be disposed of or unconventionally enhanced to create secondary products of high biological and economic value, including BSFL biomass as animal feed or, in perspective, as alternative protein source for human nutrition.     

A hidden Markov model for continuous longitudinal data with missing responses and dropout

We propose a hidden Markov model for multivariate continuous longitudinal responses with covariates that accounts for three different types of missing pattern: (I) partially missing outcomes at a given time occasion, (II) completely missing outcomes at a given time occasion (intermittent pattern), and (III) dropout before the end of the period of observation (monotone pattern). The missing-at-random (MAR) assumption is formulated to deal with the first two types of missingness, while to account for the informative dropout, we rely on an extra absorbing state. Estimation of the model parameters is based on the maximum likelihood method that is implemented by an expectation-maximization (EM) algorithm relying on suitable recursions. The proposal is illustrated by a Monte Carlo simulation study and an application based on historical data on primary biliary cholangitis.     

Dynamic properties of axonal transport of proteins and glycoproteins: A study based on the effects of metaphase blocking drugs in the developing optic pathway of chick embryos

Some properties of the axonal transport of proteins and glycoproteins along the optic pathway of chick embryos and newly hatched chicks were studied by labelling retinal ganglion cells with 3H-proline or 3H-fucose. A study of the effects of colchicine (COL) and vinblastine (VLB) on embryonic axonal transport was also carried out. Marked changes in the efficiency of axonal transport were found throughout development. In particular, the fraction of retinal ganglion cell proteins which is rapidly exported toward tectal terminals increases during embryonic life but steadily decreases after hatching. Glycoprotein transport behaves similarly except that its efficiency is relatively higher at stages when critical events of synaptic maturation in the tectum are reported to occur. Embryonic axonal transport is blocked by COL and VLB at very low intravitreal concentrations. Retinal protein synthesis and the morphology of ganglion cells are profoundly altered by the drugs: in general, COL and VLB effects were much more marked in embryonic than in mature neurons. An analysis of the time course of rapid transport along embryonic optic axons was carried out by reducing the efflux of labelled proteins from the eye by giving VLB intravitreally 2 h after the pulse. It revealed some peculiar features in the retino-tectal migration of glycoproteins and confirmed their progressive accumulation within terminals as previously described by radioautography. These results suggest that axonal transport of proteins during embryonic life undergoes changes in parallel with synaptic maturation. It may thus be considered as one of the factors controlling the genesis of neuronal networks.     

Random Walk Models for Bayesian Clustering of Gene Expression Profiles

The analysis of gene expression temporal profiles is a topic of increasing interest in functional genomics. Model-based clustering methods are particularly interesting because they are able to capture the dynamic nature of these data and to identify the optimal number of clusters. We have defined a new Bayesian method that allows us to cope with some important issues that remain unsolved in the currently available approaches: the presence of time dislocations in gene expression, the non-stationarity of the processes generating the data, and the presence of data collected on an irregular temporal grid. Our method, which is based on random walk models, requires only mild a priori assumptions about the nature of the processes generating the data and explicitly models inter-gene variability within each cluster. It has first been validated on simulated datasets and then employed for the analysis of a dataset relative to serum-stimulated fibroblasts. In all cases, the results have been promising, showing that the method can be helpful in functional genomics research.     

Regulation of a formin complex by the microtubule plus end protein tea1p

The plus ends of microtubules have been speculated to regulate the actin cytoskeleton for the proper positioning of sites of cell polarization and cytokinesis. In the fission yeast Schizosaccharomyces pombe, interphase microtubules and the kelch repeat protein tea1p regulate polarized cell growth. Here, we show that tea1p is directly deposited at cell tips by microtubule plus ends. Tea1p associates in large "polarisome" complexes with bud6p and for3p, a formin that assembles actin cables. Tea1p also interacts in a separate complex with the CLIP-170 protein tip1p, a microtubule plus end-binding protein that anchors tea1p to the microtubule plus end. Localization experiments suggest that tea1p and bud6p regulate formin distribution and actin cable assembly. Although single mutants still polarize, for3Deltabud6Deltatea1Delta triple-mutant cells lack polarity, indicating that these proteins contribute overlapping functions in cell polarization. Thus, these experiments begin to elucidate how microtubules contribute to the proper spatial regulation of actin assembly and polarized cell growth.     

TNFα expressed on the surface of microparticles modulates endothelial cell fate in rheumatoid arthritis

Background

Rheumatoid arthritis (RA) is associated with a high prevalence of atherosclerosis. Recently increased levels of microparticles (MPs) have been reported in patients with RA. MPs could represent a link between autoimmunity and endothelial dysfunction by expressing tumor necrosis factor alpha (TNFα), a key cytokine involved in the pathogenesis of RA, altering endothelial apoptosis and autophagy. The aim of this study was to investigate TNFα expression on MPs and its relationship with endothelial cell fate.

Methods

MPs were purified from peripheral blood from 20 healthy controls (HC) and from 20 patients with RA, before (time (T)0) and after (T4) 4-month treatment with etanercept (ETA). Surface expression of TNFα was performed by flow cytometry analysis. EA.hy926 cells, an immortalized endothelial cell line, were treated with RA-MPs purified at T0 and at T4 and also, with RA-MPs in vitro treated with ETA. Apoptosis and autophagy were then evaluated.

Results

RA-MPs purified at T0 expressed TNFα on their surface and this expression significantly decreased at T4. Moreover, at T0 RA-MPs, significantly increased both apoptosis and autophagy levels on endothelial cells, in a dose-dependent manner. RA-MPs did not significantly change these parameters after 4 months of in vivo treatment with ETA.

Conclusions

Our data demonstrate that MPs isolated from patients with RA exert a pathological effect on endothelial cells by TNFα expressed on their surface. In vivo and in vitro treatment with ETA modulates this effect, suggesting anti-TNF therapy protects against endothelial damage in patients with RA.

     

Engineering a peptide epitope display system on filamentous bacteriophage

Abstract: The genome of bacteriophage fd has been engineered to allow foreign amino acid sequences to be displayed in the exposed N-terminal segment of the major coat protein in the virus particle: small peptides can be encoded directly; larger peptides are encoded in hybrid virions, in which wild-type coat protein subunits are interspersed with coat proteins displaying the foreign peptides. Biophysical techniques, such as X-ray diffraction, indicate that the inclusion of the peptides can be achieved without significant disturbance to the helical parameters that define the protein—protein interactions in the assembled virion and the exposure of the peptides can be verified by analysing the susceptibility to attack by proteolytic enzymes. Peptide sequences from the V3 loop of the surface glycoprotein gp120 of HIV-1 strain MN (HIV-1_MN) displayed in this way are remarkably effective structural mimics of the natural epitope. They are recognised by human HIV antisera and evoke high titres of virus-neutralizing antibodies in mice. Antibody production is stimulated by simultaneous inoculation with T cell epitopes similarly displayed on filamentous bacteriophage. The bacteriophage display system offers a powerful means of studying the immunological recognition of proteins. The specificity of the immune response, the ability to recruit helper T cells, the lack of need for external adjuvants and the structural mimicry of defined peptide epitopes, suggest that it will also be an inexpensive and simple route to the production of effective vaccines.     

Alkaloid and lignan constituents of Cinnamosma madagascariensis

A new lignan glycoside, 5-methoxy-9-β-xylopyranosyl-(-)- isolariciresinol and two indole alkaloids have been characterised from the bark of Cinnamosma madagascariensis.