The N-terminal sequence of antileukoprotease isolated from bronchial secretion

Antileukoprotease (ALP) was isolated from bronchial secretion. The amino acid composition as well as the N-terminal sequence were determined. No homology with other low molecular weight proteinase inhibitors was found.     

Melanoma RBPome identification reveals PDIA6 as an unconventional RNA-binding protein involved in metastasis

RNA-binding proteins (RBPs) have been relatively overlooked in cancer research despite their contribution to virtually every cancer hallmark. Here, we use RNA interactome capture (RIC) to characterize the melanoma RBPome and uncover novel RBPs involved in melanoma progression. Comparison of RIC profiles of a non-tumoral versus a metastatic cell line revealed prevalent changes in RNA-binding capacities that were not associated with changes in RBP levels. Extensive functional validation of a selected group of 24 RBPs using five different in vitro assays unveiled unanticipated roles of RBPs in melanoma malignancy. As proof-of-principle we focused on PDIA6, an ER-lumen chaperone that displayed a novel RNA-binding activity. We show that PDIA6 is involved in metastatic progression, map its RNA-binding domain, and find that RNA binding is required for PDIA6 tumorigenic properties. These results exemplify how RIC technologies can be harnessed to uncover novel vulnerabilities of cancer cells.     

Selenium content of livers from sex-linked dwarf and normal broiler breeders

Plasma concentrations of cGH, T₃, and T₄ were not different between dwarf and normal broiler breeders. Normal hens had a liver selenium content of 710±35 ng/g, and dwarf hens 656 ±nine ng/g (n=8). Following injections into a wing vein of different doses (1.5, 3, 6, 12, and 24 μg/kg) of the hypothalamic hormone TRH, GH was increased after 15 min. This effect seemed to last longer in dwarf chickens. Plasma concentrations of T₃ increased significantly 1 h after TRH in normal hens, but TRH was ineffective in raising T₃ levels in dwarf animals. The selenium content of livers obtained following decapitation after 2 h was also increased in normal hens up to 902±42 ng/g using the highest dose of TRH (24 μg/kg). This seemed not to be the case for dwarf animals. A much smaller. number of hepatic cGH receptors was also found in dwarf hens, whereas the affinity of the hepatic GH receptor was not influenced by the genotype. It is concluded that the sex-linked dwarf hens are unable to increase their hepatic T₄ into T₃ conversion following a TRH challenge probably because of a deficiency in hepatic GH receptors. The lower content of selenium in dwarfs and their inability to increase its uptake after TRH seem therefore to support the hypothesis that selenium has a direct role in the activity of the 5′-deiodinase complex.     

High Mortality amongst Adolescents and Adults with Bacterial Meningitis in Sub-Saharan Africa: An Analysis of 715 Cases from Malawi

Mortality from bacterial meningitis in African adults is significantly higher than those in better resourced settings and adjunctive therapeutic interventions such as dexamethasone and glycerol have been shown to be ineffective. We conducted a study analysing data from clinical trials of bacterial meningitis in Blantyre, Malawi to investigate the clinical parameters associated with this high mortality.

Methods

We searched for all clinical trials undertaken in Blantyre investigating bacterial meningitis from 1990 to the current time and combined the data from all included trial datasets into one database. We used logistic regression to relate individual clinical parameters to mortality. Adults with community acquired bacterial meningitis were included if the CSF culture isolate was consistent with meningitis or if the CSF white cell count was >100 cells/mm³ (>50% neutrophils) in HIV negative participants and >5 cells/mm³ in HIV positive participants. Outcome was measured by mortality at discharge from hospital (after 10 days of antibiotic therapy) and community follow up (day 40).

Results

Seven hundred and fifteen episodes of bacterial meningitis were evaluated. The mortality rate was 45% at day 10 and 54% at day 40. The most common pathogens were S.pneumoniae (84% of positive CSF isolates) and N.meningitidis (4%). 607/694 (87%) participants tested were HIV antibody positive. Treatment delays within the hospital system were marked. The median presenting GCS was 12/15, 17% had GCS<8 and 44.9% had a seizure during the illness. Coma, seizures, tachycardia and anaemia were all significantly associated with mortality on multivariate analysis. HIV status and pneumococcal culture positivity in the CSF were not associated with mortality. Adults with community acquired bacterial meningitis in Malawi present with a severe clinical phenotype. Predictors of high mortality are different to those seen in Western settings. Optimising in-hospital care and minimising treatment delays presents an opportunity to improve outcomes considerably.     

Fruit Traits in Baboon Diet: A Comparison with Plant Species Characteristics in West Africa

Primate fruit choice among plant species has been attributed to different morphological plant and fruit characteristics. Despite a high abundance of animal-dispersed plant species in the savanna–forest mosaic of West Africa, few data are available on the interplay between morphological fruit traits and primate fruit consumers in this ecosystem. We tested whether olive baboons (Papio anubis) at Comoé National Park, north-eastern Ivory Coast, prefer fruit species with particular characteristics relative to the availability of these traits among the woody plant species at the study site. Specifically we were interested in the suites of traits that best predict fruit choice and seed handling by baboons. The baboons ate fruit/seeds from 74 identified plant species, representing 25 percent of the regional pool of woody plant species. They preferred trees to shrubs and lianas as fruit sources. Otherwise, baboons seemed to consume whatever fruit type, color, and size of fruit and seeds available, though they especially included larger fruit into their diet. Against expectations from the African bird–monkey fruit syndrome of brightly colored drupes and berries, baboons ate mostly species having large, dull-colored fruit. Fruit type and color best described whether baboons included a species into their diet, whereas fruit type and seed size best predicted whether baboons predated upon the seeds of their food plant species. As most plant species at the study site had medium-sized to large fruits and seeds, large frugivores like baboons might be particularly important for plant fitness and plant community dynamics in West African savanna–forest ecosystems.     

High-affinity AKAP7delta-protein kinase A interaction yields novel protein kinase A-anchoring disruptor peptides

PKA (protein kinase A) is tethered to subcellular compartments by direct interaction of its regulatory subunits (RI or RII) with AKAPs (A kinase-anchoring proteins). AKAPs preferentially bind RII subunits via their RII-binding domains. RII-binding domains form structurally conserved amphipathic helices with unrelated sequences. Their binding affinities for RII subunits differ greatly within the AKAP family. Amongst the AKAPs that bind RIIalpha subunits with high affinity is AKAP7delta [AKAP18delta; K(d) (equilibrium dissociation constant) value of 31 nM]. An N-terminally truncated AKAP7delta mutant binds RIIalpha subunits with higher affinity than the full-length protein presumably due to loss of an inhibitory region [Henn, Edemir, Stefan, Wiesner, Lorenz, Theilig, Schmidtt, Vossebein, Tamma, Beyermann et al. (2004) J. Biol. Chem. 279, 26654-26665]. In the present study, we demonstrate that peptides (25 amino acid residues) derived from the RII-binding domain of AKAP7delta bind RIIalpha subunits with higher affinity (K(d)=0.4+/-0.3 nM) than either full-length or N-terminally truncated AKAP7delta, or peptides derived from other RII binding domains. The AKAP7delta-derived peptides and stearate-coupled membrane-permeable mutants effectively disrupt AKAP-RII subunit interactions in vitro and in cell-based assays. Thus they are valuable novel tools for studying anchored PKA signalling. Molecular modelling indicated that the high affinity binding of the amphipathic helix, which forms the RII-binding domain of AKAP7delta, with RII subunits involves both the hydrophobic and the hydrophilic faces of the helix. Alanine scanning (25 amino acid peptides, SPOT technology, combined with RII overlay assays) of the RII binding domain revealed that hydrophobic amino acid residues form the backbone of the interaction and that hydrogen bond- and salt-bridge-forming amino acid residues increase the affinity of the interaction.     

Microtubules of guard cells are light sensitive

Guard cells of stomata are characterized by ordered bundles of microtubules radiating from the ventral side toward the dorsal side of the cylindrical cell. It was suggested that microtubules play a role in directing the radial arrangement of the cellulose micro-fibrils of guard cells. However, the role of microtubules in daily cycles of opening and closing of stomata is not clear. The organization of microtubules in guard cells of Commelina communis leaves was studied by analysis of three-dimensional immunofluorescent images. It was found that while guard cell microtubules in the epidermis of leaves incubated in the light were organized in parallel, straight and dense bundles, in the dark they were less straight and oriented randomly near the stomatal pore. The effect of blue and red light on the organization of guard cell microtubules resembled the effects of white light and dark respectively. When stomata were induced to open in the dark with fusicoccin, microtubules remained in the dark configuration. Furthermore, when incubated in the light, guard cell microtubules were more resistant to oryzalin. Similarly, microtubules of Arabidopsis guard cells, expressing green fluorescent protein-tubulin alpha 6, were disorganized in the dark, but were organized in parallel arrays in the presence of white light. The dynamics of microtubule rearrangement upon transfer of intact leaves from dark to light was followed in single stomata, showing that an arrangement of microtubules typical for light conditions was obtained after 1 h in the light. Our data suggest that microtubule organization in guard cells is responsive to light signals.     

Influence of steam and dry heat pretreatment on fibre properties and cellulase degradation of cellulosic fibres

Cellulosic fabric samples of cotton, viscose, lyocell and modal were pretreated with steam and dry heat in the range of 100–190°C. The samples were then treated with a Trichoderma reesei cellulase preparation (total culture filtrate – TC), with mechanical agitation, at a high enzyme dosage of 75% by weight of fabric, for 8 hours. Generally, viscose proved to be easily degradable, followed by cotton and modal. The degree of hydrolysis was the least for Lyocell. Dry heat pretreatments exerted a lower influence on degradation rate than steam pretreatments which showed a distinct maximum at a steam temperature of 130°C. The hydrolysis rate varied strongly depending on treatment conditions and fibre type. Water retention values in treated substrates were changed by up to 20% of initial values.