247 results for qubit oscillator frequency
Original paper - Comparison of media and serum supplementation for generation of monophosphoryl lipid A/interferon-γ–matured type I dendritic cells for immunotherapy
Contributors: Sonja T.H.M. Kolanowski, Lathees Sritharan, Suzanne N. Lissenberg-Thunnissen, Gijs M.W. Van Schijndel, S. Marieke Van Ham, Anja Ten Brinke
... Ex vivo–generated monocyte-derived dendritic cells (DCs) matured with monophosphoryl lipid A (MPLA) and interferon-γ (IFN-γ) can be used as cancer immunotherapy. MPLA/IFN-γ DCs induce Th1 T cell responses and have migratory capacity. Different culture regimens have been used for generation of immunotherapeutic DCs, with varying results. In the present study, culture conditions for MPLA/IFN-γ–matured type I DCs were optimized for clinical application.
First multi-epitope subunit vaccine against extraintestinal pathogenic Escherichia coli delivered by a bacterial type-3 secretion system (T3SS)
Contributors: Andreas Wieser, Giuseppe Magistro, Dominik Nörenberg, Christiane Hoffmann, Sören Schubert
... Infections due to extraintestinal pathogenic E. coli (ExPEC) are very common in humans as well as in animals. In humans ExPEC infections include urinary tract infections (UTI), septicemia, and wound infections, which result in significant morbidity, mortality, and substantial healthcare costs. In view of the increasing number of ExPEC infections caused by more and more resistant strains, effective prevention would be desirable. Given the rising treatment costs, a vaccine may be cost-effective in selected patient groups, such as women with recurrent UTI, patients with neurologic disorders impairing bladder function and men with prostate hyperplasia. Previous vaccine studies used single target proteins or whole inactivated ExPEC cells. Here, we describe a vaccine system for oral application based on artificial multiple subunit vaccine proteins. Those multi-epitope proteins are composed of predicted epitopes derived from ExPEC virulence-associated proteins. As ExPEC are known to form intracellular biofilms in the urothelium and can also resist killing by non-activated macrophages, T-cell responses are supposed to be an important measure to counteract these stages of ExPEC during infection. Therefore, a live bacterial antigen delivery system based upon the Salmonella type-III secretion system (T3SS) was used in this study to directly deliver the vaccine proteins into the cytoplasm of the host cells. Epitope-rich domains of the proteins FyuA, IroN, ChuA, IreA, Iha, and Usp were expressed in an attenuated Salmonella enterica serovar Typhimurium strain and translocated into target cells for extended periods of time inducing a strong T-cell response. No significant antibody titre increase against the secreted vaccine proteins could be detected in vaginal wash or serum. Despite that, one of the vaccine proteins was able to significantly reduce bacterial load in the challenge model of intraperitoneal sepsis. This study shows that a vaccine encompassing distinct epitopes of virulence-associated ExPEC proteins (i) can be applied for a T3SS-dependent vaccination strategy, (ii) elicits T-cell responses and (iii) confers protection after a single application.
Fragmentation of peptides with intra-chain disulfide bonds in triple quadrupole mass spectrometry and its quantitative application to biological samples
Contributors: Yun Chen, Shanlei Qiao, Ce Wang
... A growing number of peptides are being used today in bioanalytical laboratories. Because of this, there is an increasing interest in the development of highly sensitive, specific and robust liquid chromatography/tandem mass spectrometry (LC/MS/MS) assays for the quantitative analysis of peptides in biological samples. Among the mass spectrometers previously used for peptide quantification, triple quadrupole mass spectrometers are generally not considered the instrument of choice. With this instrumentation, collision cascades or multiple fragmentations tend to generate multiple peaks that have weak intensities. This leads to a loss in detection sensitivity. However, in cases where immonium product ions were formed in abundance, it was found that peptide quantification succeeded. A common feature of these peptides is their intra-loop structure. To elucidate the usefulness of this feature in fragmentation, several peptide analytes with intra-chain disulfide bonds were investigated in this study, including a newly synthesized analog having a single amino acid substitution. The results presented here indicate that abrupt bond cleavage from the intra-loop structure of peptides could be one of the premises for intense immonium ion generation. In contrast, any preferential cleavage of peptide bonds (e.g., proline effect) that gives rise to a linearized sequence would break the intactness of the loop and prevent it from completely dissociating. In addition, the utilization of immonium product ions in LC/MS/MS was demonstrated for the determination of peptides with intra-chain disulfide bonds in biological fluids.
Research brief - Impact of Using Updated Food Consumption and Composition Data on Selected MyPyramid Food Group Nutrient Profiles
Contributors: Sedigheh Yamini, WenYen Juan, Kristin Marcoe, Patricia Britten
... To examine the changes observed in 5 nutrients of selected USDA food subgroups by partitioning the overall changes into those caused by consumption changes over time, and those caused by nutrient database revisions.
Contributors: Carmen Stavarache, B. Yim, M. Vinatoru, Y. Maeda
... The influence of ultrasound (200kHz) on the decomposition of water solution (around 100 ppm) of chlorobenzene in the presence and absence of iron and palladium sulfates was investigated. The intermediates of sonolysis were identified, leading to a deeper insight on the degradation mechanism. It was established that chlorobenzene, a volatile compound, is degraded mainly by pyrolysis inside cavitation bubbles. The first sonolysis product is benzene, formed, by an outside cavitation reaction, from phenyl radicals and hydrogen atoms, sonolytically generated from water. Polyphenolic compounds, as chlorobenzene sonochemical degradation, are reported. Alternative mechanism to chlorobenzene sonolysis is advanced to explain phenols, chlorophenols and benzene formation. This work brings some light on the reaction sites and decomposition mechanisms during sonication of chlorobenzene. Keywords: chlorobenzene, sonolysis, sonochemical mechanism, waste water treatment.
The dominant 55kDa allergen of the subtropical Bahia grass (Paspalum notatum) pollen is a group 13 pollen allergen, Pas n 13
Contributors: Janet M. Davies, Astrid Voskamp, Thanh D. Dang, Benjamin Pettit, Dorothy Loo, Arnd Petersen, Michelle M. Hill, John W. Upham, Jennifer M. Rolland, Robyn E. O’Hehir
... Bahia grass, Paspalum notatum, is an important pollen allergen source with a long season of pollination and wide distribution in subtropical and temperate regions. We aimed to characterize the 55kDa allergen of Bahia grass pollen (BaGP) and ascertain its clinical importance. BaGP extract was separated by 2D-PAGE and immunoblotted with serum IgE of a grass pollen-allergic patient. The amino-terminal protein sequence of the predominant allergen isoform at 55kDa had similarity with the group 13 allergens of Timothy grass and maize pollen, Phl p 13 and Zea m 13. Four sequences obtained by rapid amplification of the allergen cDNA ends represented multiple isoforms of Pas n 13. The predicted full length cDNA for Pas n 13 encoded a 423 amino acid glycoprotein including a signal peptide of 28 residues and with a predicted pI of 7.0. Tandem mass spectrometry of tryptic peptides of 2D gel spots identified peptides specific to the deduced amino acid sequence for each of the four Pas n 13 cDNA, representing 47% of the predicted mature protein sequence of Pas n 13. There was 80.6% and 72.6% amino acid identity with Zea m 13 and Phl p 13, respectively. Reactivity with a Phl p 13-specific monoclonal antibody AF6 supported designation of this allergen as Pas n 13. The allergen was purified from BaGP extract by ammonium sulphate precipitation, hydrophobic interaction and size exclusion chromatography. Purified Pas n 13 reacted with serum IgE of 34 of 71 (48%) grass pollen-allergic patients and specifically inhibited IgE reactivity with the 55kDa band of BaGP for two grass pollen-allergic donors. Four isoforms of Pas n 13 from pI 6.3–7.8 had IgE-reactivity with grass pollen allergic sera. The allergenic activity of purified Pas n 13 was demonstrated by activation of basophils from whole blood of three grass pollen-allergic donors tested but not control donors. Pas n 13 is thus a clinically relevant pollen allergen of the subtropical Bahia grass likely to be important in eliciting seasonal allergic rhinitis and asthma in grass pollen-allergic patients.
Contributors: K. Yamada, H. Hoshikawa, S. Maki, T. Ozaki, Y. Kuroki, S. Kamado, Y. Kojima
... The addition of 0.25–0.5at.% of Ag to Mg–3.4Gd–0.1Zr (at.%) alloy significantly enhances the age-hardening response, particularly in underaged conditions. The peak-aged Mg–3.4Gd–0.5Ag–0.1Zr alloy exhibits an extremely high ultimate strength, of above 410MPa. The plate precipitates are formed on the basal plane of the matrix with a high number density in underaged conditions and co-exist with β′ phase in the peak-aged condition. The co-precipitation effectively contributes to the strengthening of the alloy. In the Ag-added Mg–Gd alloys, characteristic initial structure change is found.
Identification and expression analysis of cold and freezing stress responsive genes of Brassica oleracea
Contributors: Nasar Uddin Ahmed, Hee-Jeong Jung, Jong-In Park, Yong-Gu Cho, Yoonkang Hur, Ill-Sup Nou
... Cold and freezing stress is a major environmental constraint to the production of Brassica crops. Enhancement of tolerance by exploiting cold and freezing tolerance related genes offers the most efficient approach to address this problem. Cold-induced transcriptional profiling is a promising approach to the identification of potential genes related to cold and freezing stress tolerance. In this study, 99 highly expressed genes were identified from a whole genome microarray dataset of Brassica rapa. Blast search analysis of the Brassica oleracea database revealed the corresponding homologous genes. To validate their expression, pre-selected cold tolerant and susceptible cabbage lines were analyzed. Out of 99 BoCRGs, 43 were differentially expressed in response to varying degrees of cold and freezing stress in the contrasting cabbage lines. Among the differentially expressed genes, 18 were highly up-regulated in the tolerant lines, which is consistent with their microarray expression. Additionally, 12 BoCRGs were expressed differentially after cold stress treatment in two contrasting cabbage lines, and BoCRG54, 56, 59, 62, 70, 72 and 99 were predicted to be involved in cold regulatory pathways. Taken together, the cold-responsive genes identified in this study provide additional direction for elucidating the regulatory network of low temperature stress tolerance and developing cold and freezing stress resistant Brassica crops.
Original article - Multi-locus genotyping reveals absence of genetic structure in field populations of the brown ear tick (Rhipicephalus appendiculatus) in Kenya
Contributors: Esther G. Kanduma, Joram M. Mwacharo, Stephen Mwaura, Joyce N. Njuguna, Inosters Nzuki, Peter W. Kinyanjui, Naftaly Githaka, Heloise Heyne, Olivier Hanotte, Robert A. Skilton
... Rhipicephalus appendiculatus is an important tick vector of several pathogens and parasitizes domestic and wild animals across eastern and southern Africa. However, its inherent genetic variation and population structure is poorly understood. To investigate whether mammalian host species, geographic separation and resulting reproductive isolation, or a combination of these, define the genetic structure of R. appendiculatus, we analyzed multi-locus genotype data from 392 individuals from 10 geographic locations in Kenya generated in an earlier study. These ticks were associated with three types of mammalian host situations; (1) cattle grazing systems, (2) cattle and wildlife co-grazing systems (3) wildlife grazing systems without livestock. We also analyzed data from 460 individuals from 10 populations maintained as closed laboratory stocks and 117 individuals from five other species in the genus Rhipicephalus. The pattern of genotypes observed indicated low levels of genetic differentiation between the ten field populations (FST=0.014±0.002) and a lack of genetic divergence corresponding to the degree of separation of the geographic sampling locations. There was also no clear association of particular tick genotypes with specific host species. This is consistent with tick dispersal over large geographic ranges and lack of host specificity. In contrast, the 10 laboratory populations (FST=0.248±0.015) and the five other species of Rhipicephalus (FST=0.368±0.032) were strongly differentiated into distinct genetic groups. Some laboratory bred populations diverged markedly from their field counterparts in spite of originally being sampled from the same geographic locations. Our results demonstrate a lack of defined population genetic differentiation in field populations of the generalist R. appendiculatus in Kenya, which may be a result of the frequent anthropogenic movement of livestock and mobility of its several wildlife hosts between different locations.
Brief report - PIKK-dependent phosphorylation of Mre11 induces MRN complex inactivation by disassembly from chromatin
Contributors: Michela Di Virgilio, Carol Y. Ying, Jean Gautier
... The role of Mre11 phosphorylation in the cellular response to DNA double-strand breaks (DSBs) is not well understood. Here, we show that phosphorylation of Mre11 at SQ/TQ motifs by PIKKs (PI3 Kinase-related Kinases) induces MRN (Mre11–Rad50–Nbs1) complex dissociation from chromatin by reducing Mre11 affinity for DNA. Whereas phosphorylation of Mre11 at these residues is not required for DSB-induced ATM (Ataxia-Telangiectasia mutated) activation, abrogation of Mre11 dephosphorylation impairs ATM signaling. Our study provides a functional characterization of the DNA damage-induced Mre11 phosphorylation, and suggests that MRN inactivation participates in the down-regulation of damage signaling during checkpoint recovery following DSB repair.