Streptococcus pneumoniae
is the main cause of pneumonia, meningitis, and other conditions that kill thousands of children every year worldwide. The replacement of pneumococcal serotypes among the ...vaccinated population has evidenced the need for new vaccines with broader coverage and driven the research for protein-based vaccines. Pneumococcal surface protein A (PspA) protects
S. pneumoniae
from the bactericidal effect of human apolactoferrin and prevents complement deposition. Several studies indicate that PspA is a very promising target for novel vaccine formulations. Here we describe a production and purification process for an untagged recombinant fragment of PspA from clade 4 (PspA4Pro), which has been shown to be cross-reactive with several PspA variants. PspA4Pro was obtained using lactose as inducer in Phytone auto-induction batch or glycerol limited fed-batch in 5-L bioreactor. The purification process includes two novel steps: (i) clarification using a cationic detergent to precipitate contaminant proteins, nucleic acids, and other negatively charged molecules as the lipopolysaccharide, which is the major endotoxin; and (ii) cryoprecipitation that eliminates aggregates and contaminants, which precipitate at −20 °C and pH 4.0, leaving PspA4Pro in the supernatant. The final process consisted of cell rupture in a continuous high-pressure homogenizer, clarification, anion exchange chromatography, cryoprecipitation, and cation exchange chromatography. This process avoided costly tag removal steps and recovered 35.3 ± 2.5% of PspA4Pro with 97.8 ± 0.36% purity and reduced endotoxin concentration by >99.9%. Circular dichroism and lactoferrin binding assay showed that PspA4Pro secondary structure and biological activity were preserved after purification and remained stable in a wide range of temperatures and pH values.
This paper attempts to point out a disparity between keeping rabies epidemiological statistics and rabies virus sequencing in the Russian Federation. While data on rabies prevention and laboratory ...detection are duly gathered, virus sequencing efforts remain insufficient. Along with a lack of public information and mass vaccination campaigns for wildlife and pets, this also might have an impact on the current rabies situation, which is of high risk in Russia. Additionally, drawing on GenBank data, it is suggested that some isolated rabies variants might be circulating in the country.
07 PPARβ, un exercice mimétique Lendoye, E; Giordano, C; Sibille, B ...
Diabetes & metabolism,
March 2012, Letnik:
38
Journal Article
Recenzirano
Introduction L’exercice induit un remodelage oxydatif du muscle squelettique caractérisé par une augmentation du nombre de fibres oxydatives et de capillaires sanguins. Chez la souris, l’activation ...ou la surexpression « muscle spécifique » de PPARβ (Peroxisome Proliferator-Activated Receptor beta) donne lieu aux mêmes modifications. Chez les animaux traités avec un agoniste de PPARβ ce remodelage est extrêmement rapide puisque terminé en 48 heures. Nos travaux récents montrent que dans ce laps de temps, le remodelage musculaire s’accompagne, comme chez les individus entrainés, d’une augmentation de la densité myonucléaire et d’un changement de la composition trimérique de l’AMPK (AMP-activated protein kinase). Matériels et méthodes La densité myonucléaire a été mesurée chez des souris transgéniques qui sur-expriment ou non PPARβ spécifiquement au niveau musculaire, ainsi que chez des souris traitées ou non avec du GW0742, activateur spécifique de PPARβ. Les niveaux d’expression des sous-unités de l’AMPK ont été analysés par PCR quantitative et par western blot. Les effets de l’entraînement et du jeûne, ont également été analysés. Résultats Nous montrons d’une part que l’activation pharmacologique de PPARβ provoque une accrétion myonucléaire rapide et massive (+20 % après 48 h), qui semble résulter de la fusion de précurseurs musculaires pré-existant avec les fibres musculaires. D’autre part, l’activation de PPARβ induit, in vivo et in cellulo, une diminution (- 50 %) rapide (2 h) et soutenue (48 h) de l’expression de l’AMPKγ3, sous-unité de l’AMPK exprimée uniquement au niveau musculaire. L’augmentation de la densité myonucléaire et la diminution de l’expression de l’AMPK γ 3 sont aussi retrouvées dans les muscles de souris surexprimant PPARβ. Conclusion : La rapidité remarquable de tous ces événements chez des souris traitées avec un agoniste spécifique de PPARβ témoigne de l’extrême flexibilité du muscle squelettique tant au niveau structural que métabolique. L’importante accrétion myonucléaire et les modifications de la composition de l’AMPK peuvent expliquer en partie la reprogrammation des fibres.
A symbolic interactionist perspective on the emotions is presented that highlights their social character, forges links to cognitive processes, and suggests ways in which emotions influence long-term ...patterns of criminal involvement. This neo-Meadian perspective contrasts with theories of desistance that focus on the role of informal social controls and develops the view of an emotional self that flourishes somewhat independent of the major role transitions typically emphasized in sociological studies of the life course. The authors also explore ways in which attention to the emotional realms of experience adds to traditional treatments of the impact of adult transition events (e.g., the good marriage effect). Interviews with male and female adolescent offenders and two waves of adult followup data document general patterns of association and support the argument that a social view of emotional processes is critical to a comprehensive understanding of life course patterns of criminal continuity and change. Adapted from the source document.
Abstract Purpose To assess changes in self-reported intimate partner violence (IPV) experience from adolescence through young adulthood. To examine whether individual change in indicators of ...relationship context—qualities and dynamics of the relationship, changes in partners, and relationship type (dating, cohabiting, and married)—were associated with change in self-reports of IPV. Methods Drawing on longitudinal population-based data, the Toledo Adolescent Relationships Study, we used fixed-effects models to estimate within-person change in associations between features of respondents' intimate relationships and the proportion of relationships with IPV from adolescence through young adulthood. Analyses focused on 1,146 young men and women ages 13–29 years (51% female). Items measuring IPV were from the Conflict Tactics Scale. Results More than half of respondents (53%) experienced discontinuity in IPV across relationships. Among those reporting violence, the vast majority (87%) did not experience violence in all of their relationships. Age-related patterns were similar for men and women with IPV peaking in young adulthood. Infidelity, frequency of disagreements, and partner continuity were associated with a higher proportion of relationships with IPV. Improvements in the nature and character of romantic relationships were associated with a lower accumulation of IPV experiences. Conclusions IPV, although prevalent, does not represent a consistent experience. As young adults develop higher quality relationships they move toward desistance from IPV. Yet, variability in these experiences is observed, supporting previous calls for programs that promote the development of healthy relationships among adolescents and young adults.
Leber's hereditary optic neuropathy (LHON), the most frequent mitochondrial disease, is associated with mitochondrial DNA (mtDNA) point mutations affecting Complex I subunits, usually homoplasmic. ...This blinding disorder is characterized by incomplete penetrance, possibly related to several genetic modifying factors. We recently reported that increased mitochondrial biogenesis in unaffected mutation carriers is a compensatory mechanism, which reduces penetrance. Also, environmental factors such as cigarette smoking have been implicated as disease triggers. To investigate this issue further, we first assessed the relationship between cigarette smoke and mtDNA copy number in blood cells from large cohorts of LHON families, finding that smoking was significantly associated with the lowest mtDNA content in affected individuals. To unwrap the mechanism of tobacco toxicity in LHON, we exposed fibroblasts from affected individuals, unaffected mutation carriers and controls to cigarette smoke condensate (CSC). CSC decreased mtDNA copy number in all cells; moreover, it caused significant reduction of ATP level only in mutated cells including carriers. This implies that the bioenergetic compensation in carriers is hampered by exposure to smoke derivatives. We also observed that in untreated cells the level of carbonylated proteins was highest in affected individuals, whereas the level of several detoxifying enzymes was highest in carriers. Thus, carriers are particularly successful in reactive oxygen species (ROS) scavenging capacity. After CSC exposure, the amount of detoxifying enzymes increased in all cells, but carbonylated proteins increased only in LHON mutant cells, mostly from affected individuals. All considered, it appears that exposure to smoke derivatives has a more deleterious effect in affected individuals, whereas carriers are the most efficient in mitigating ROS rather than recovering bioenergetics. Therefore, the identification of genetic modifiers that modulate LHON penetrance must take into account also the exposure to environmental triggers such as tobacco smoke.
The yeast
Saccharomyces cerevisiae
is the most used microorganism for ethanol production, however, on its wild form it cannot assimilate xylose. The previous
ex-vivo
isomerization of xylose to ...xylulose catalyzed by the enzyme xylose isomerase (XI) is an alternative to overcome this limitation. The present work evaluated continuous 2G ethanol production through xylose simultaneous isomerization and fermentation (SIF) using xylose isomerase co-immobilized with yeast. From the initial studies carried out with five different industrial
S. cerevisiae
strains, Itaiquara
®
baker´s yeast was selected due to its good performance in terms of ethanol yield (0.34 g/g) and productivity (2.1 g/L/h) having xylose as a carbon source. Continuous xylose SIF in a fixed-bed reactor was run for 7 days with high values of ethanol yield (0.37 g/g) and productivity (1.9 g/L/h). The operation for longer periods could be possible upon implementing strategies for pH and contamination control, showing great progress to achieve a feasible industrial 2G ethanol production process.
Graphic abstract
Amphiphilic copolymers of various-molecular-weight (MW) poly(ethylene glycol) (PEG) were synthesized via reversible addition–fragmentation chain transfer (RAFT) polymerization. The first PEG series, ...poly(ethylene glycol)monomethacrylate (PEGMA, average Mn 200 and 400 MW), contained an −OH terminal group, and the second series, poly(ethylene glycol) monomethyl ether monomethacrylate (PEGMMA, average Mn 200, 400, and 1000 MW), possessed an −OCH3 terminal group. A total of five PEG-functionalized copolymers contained the same hydrophobic monomer, butyl acrylate (BA), and were successfully reproduced via a one-pot synthesis. The resulting PEG-functionalized copolymers provide a systematic trend of properties including surface tension, critical micelle concentration (CMC), cloud point (CP), and foam lifetime based on the average MW of the PEG monomer and final polymer properties. In general, the PEGMA series produced more stable foams with PEGMA200 demonstrating the least change in foam height with time over a 10 min period. The important exception is that at elevated temperatures, the PEGMMA1000 copolymer had longer foam lifetimes. The self-assembling copolymers were characterized by gel permeation chromatography (GPC), 1H nuclear magnetic resonance (NMR), attenuated total reflection Fourier transform infrared (FTIR-ATR), CMC, surface tension, dynamic light scattering (DLS), as a foam using a dynamic foam analyzer (DFA), and foam lifetime at ambient and elevated temperatures. The copolymers described highlight the importance of the PEG monomer MW and terminal end group for surface interaction and final polymer properties for foam stabilization.
▪.
▶
Thermomyces lanuginosus lipase (TLL) immobilized by multipoint covalent attachment on glyoxyl-resin allowed obtaining derivatives with the highest hydrolytic activity (olive oil emulsion ...hydrolysis) and thermal stability. ▶ Lipase from
Pseudomonas fluorescens (PFL) showed to be more active in ester synthesis than olive oil emulsion hydrolysis. ▶ Immobilized lipases on resin activated with glutaraldehyde undergo strong distortion of the enzyme three-dimensional structure. ▶ Highest conversion into biodiesel was found in the transesterification of palm oil catalyzed by both TLL and PFL glyoxyl-derivatives.
Microbial lipase preparations from
Thermomyces lanuginosus (TLL) and
Pseudomonas fluorescens (PFL) were immobilized by multipoint covalent attachment on Toyopearl AF-amino-650M resin and the most active and thermal stable derivatives used to catalyze the transesterification reaction of babassu and palm oils with ethanol in solvent-free media. For this, different activating agents, mainly glutaraldehyde, glycidol and epichlorohydrin were used and immobilization parameters were estimated based on the hydrolysis of olive oil emulsion and butyl butyrate synthesis. TLL immobilized on glyoxyl-resin allowed obtaining derivatives with the highest hydrolytic activity (HA
der) and thermal stability, between 27 and 31 times more stable than the soluble lipase. Although PFL derivatives were found to be less active and thermally stables, similar formation of butyl butyrate concentrations were found for both TLL and PFL derivatives. The highest conversion into biodiesel was found in the transesterification of palm oil catalyzed by both TLL and PFL glyoxyl-derivatives.
Capabilities of highly sensitive surface-enhanced infrared absorption (SEIRA) spectroscopy are demonstrated by exploiting large-area templates (cm2) based on self-organized (SO) nanorod antennas. We ...engineered highly dense arrays of gold nanorod antennas featuring polarization-sensitive localized plasmon resonances, tunable over a broadband near- and mid-infrared (IR) spectrum, in overlap with the so-called “functional group” window. We demonstrate polarization-sensitive SEIRA activity, homogeneous over macroscopic areas and stable in time, by exploiting prototype self-assembled monolayers of IR-active octadecanthiol (ODT) molecules. The strong coupling between the plasmonic excitation and molecular stretching modes gives rise to characteristic Fano resonances in SEIRA. The SO engineering of the active hotspots in the arrays allows us to achieve signal amplitude improved up to 5.7%. This figure is competitive to the response of lithographic nanoantennas and is stable when the optical excitation spot varies from the micro- to macroscale, thus enabling highly sensitive SEIRA spectroscopy with cost-effective nanosensor devices.
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