Helicobacter pylori-induced inhibition of vascular endothelial cell functions: a role for VacA-dependent nitric oxide reduction

Epidemiological and clinical studies provide compelling support for a causal relationship between Helicobacter pylori infection and endothelial dysfunction, leading to vascular diseases. However, clear biochemical evidence for this association is limited. In the present study, we have conducted a comprehensive investigation of endothelial injury in bovine aortic endothelial cells (BAECs) induced by H. pylori-conditioned medium (HPCM) prepared from H. pylori 60190 [vacuolating cytotoxin A (Vac(+))]. BAECs were treated with either unconditioned media, HPCM (0-25% vol/vol), or Escherichia coli-conditioned media for 24 h, and cell functions were monitored. Vac(+) HPCM significantly decreased BAEC proliferation, tube formation, and migration (by up to 44%, 65%, and 28%, respectively). Posttreatment, we also observed sporadic zonnula occludens-1 immunolocalization along the cell-cell border, and increased BAEC permeability to FD40 Dextran, indicating barrier reduction. These effects were blocked by 5-nitro-2-(3-phenylpropylamino)benzoic acid (VacA inhibitor) and were not observed with conditioned media prepared from either VacA-deleted H. pylori or E. coli. The cellular mechanism mediating these events was also considered. Vac(+) HPCM (but not Vac(-)) reduced nitric oxide (NO) by \u3e50%, whereas S-nitroso-N-acetylpenicillamine, an NO donor, recovered all Vac(+) HPCM-dependent effects on cell functions. We further demonstrated that laminar shear stress, an endothelial NO synthase/NO stimulus in vivo, could also recover the Vac(+) HPCM-induced decreases in BAEC functions. This study shows, for the first time, a significant proatherogenic effect of H. pylori-secreted factors on a range of vascular endothelial dysfunction markers. Specifically, the VacA-dependent reduction in endothelial NO is indicated in these events. The atheroprotective impact of laminar shear stress in this context is also evident

Про маловідомі математичні таблиці Якова Пилипа Кулика

У статті описано маловідомі математичні таблиці професора Пражського університету Якова Пилипа Кулика. Виконано короткий аналіз складу та структури таблиць, що не тільки широко використовувались в арифметиці, алгебрі, теорії чисел і в теорії алгебраїчних рівнянь, але й мали широке практичне застосування.В статье описаны малоизвестные математические таблицы профессора Пражского университета Якова Филиппа Кулика. Произведен короткий анализ содержания и структуры таблиц, которые не только широко использовались в арифметике, алгебре, теории чисел и в теории алгебраических уравнений, но и имели широкое практическое применение.The unknown mathematical tables by Jakob Pilip Kulik – the professor of Prague University, are described in this article. The analysis of the content and structure of tables was conducted, they were not only used widely in arithmetic, algebra, the theory of numbers and in the Theory of equalizations of algebra, but They had a wide practical application

Hospital outbreak of carbapenem-resistant Enterobacterales associated with a bla OXA-48 plasmid carried mostly by Escherichia coli ST399

A hospital outbreak of carbapenem-resistant Enterobacterales was detected by routine surveillance. Whole genome sequencing and subsequent analysis revealed a conserved promiscuous blaOXA-48 carrying plasmid as the defining factor within this outbreak. Four different species of Enterobacterales were involved in the outbreak. Escherichia coli ST399 accounted for 35 of all the 55 isolates. Comparative genomics analysis using publicly available E. coli ST399 genomes showed that the outbreak E. coli ST399 isolates formed a unique clade. We developed a mathematical model of pOXA-48-like plasmid transmission between host lineages and used it to estimate its conjugation rate, giving a lower bound of 0.23 conjugation events per lineage per year. Our analysis suggests that co-evolution between the pOXA-48-like plasmid and E. coli ST399 could have played a role in the outbreak. This is the first study to report carbapenem-resistant E. coli ST399 carrying blaOXA-48 as the main cause of a plasmid-borne outbreak within a hospital setting. Our findings suggest complementary roles for both plasmid conjugation and clonal expansion in the emergence of this outbreak

In Vivo Characterization of a Wireless Telemetry Module for a Capsule Endoscopy System Utilizing a Conformal Antenna

This paper describes the design, fabrication, packaging, and performance characterization of a conformal helix antenna created on the outside of a 10 mm ×30 mm capsule endoscope designed to operate at a carrier frequency of 433 MHz within human tissue. Wireless data transfer was established between the integrated capsule system and an external receiver. The telemetry system was tested within a tissue phantom and in vivo porcine models. Two different types of transmission modes were tested. The first mode, replicating normal operating conditions, used data packets at a steady power level of 0 dBm, while the capsule was being withdrawn at a steady rate from the small intestine. The second mode, replicating the worst-case clinical scenario of capsule retention within the small bowel, sent data with stepwise increasing power levels of –10, 0, 6, and 10 dBm, with the capsule fixed in position. The temperature of the tissue surrounding the external antenna was monitored at all times using thermistors embedded within the capsule shell to observe potential safety issues. The recorded data showed, for both modes of operation, a low error transmission of 10−3 packet error rate and 10−5 bit error rate and no temperature increase of the tissue according to IEEE standards

Redox-Catalyzed Binding of Dinitrogen by Molybdenum N-tert-Hydrocarbylanilide Complexes: Implications for Dinitrogen Functionalization and Reductive Cleavage

The splitting of dinitrogen (1 atm, THF, 25 °C) by Mo(N[R]Ar)_3 (R = C(CD_3)_2CH_3, Ar = 3,5-C_6H_3Me_2) giving 2 equiv of nitride N⋮Mo(N[R]Ar)3 is found to be accelerated in the presence of sodium amalgam. Careful control of the Mo(N[R]Ar)_3 concentration led to the isolation and characterization of the anionic dinitrogen complex, [(THF)xNa][(N_2)Mo(N[R]Ar)_3], where x is from 0 to 3. Via electrochemical experiments and synthetic studies, [(THF)xNa][(N2)Mo(N[R]Ar)_3] is found to be a key intermediate in the acceleration of N_2 splitting by Mo(N[R]Ar)_3 in the presence of sodium amalgam. Accordingly, in the presence of an electron acceptor, [(THF)xNa][(N_2)Mo(N[R]Ar)_3] reacts with Mo(N[R]Ar)_3 to give the neutral N2-bridged complex (μ-N_2){Mo(N[R]Ar)_3}_2, which in turn splits to 2 equiv of nitride N⋮Mo(N[R]Ar)3. It is seen that the function of sodium amalgam in this system is as a redox catalyst, accelerating the conversion of Mo(N[R]Ar)_3 to (μ-N2){Mo(N[R]Ar)3}2, a dinuclear dinitrogen complex that does not lose N_2 readily. Electrochemical or chemical outer-sphere oxidation of [(THF)xNa][(N2)Mo(N[R]Ar)_3] leads to rapid N_2 evolution with regeneration of Mo(N[R]Ar)_3, presumably via the neutral mononuclear dinitrogen complex (N2)Mo(N[R]Ar)_3. In situ generated [(THF)xNa][(N_2)Mo(N[R]Ar)_3] was efficiently trapped by ClSiMe3 to give (Me3SiNN)Mo(N[R]Ar)_3. This complex underwent reaction with methyl triflate to give the dimethyl hydrazido cationic species, [(Me_2NN)Mo(N[R]Ar)_3][OTf]. The synthesis of the monomethyl complex (MeNN)Mo(N[R]Ar)_3 also was achieved. Experiments designed to trap the neutral mononuclear dinitrogen complex (N_2)Mo(N[R]Ar)_3 gave rise to efficient syntheses of heterodinuclear dinitrogen complexes including (Ph[tBu]N)3Ti(μ-N_2)Mo(N[R]Ar)_3, which also was synthesized in its ^(15)N_2-labeled form. Synthesis and characterization data for the new N-adamantyl-substituted three-coordinate molybdenum(III) complex Mo(N[Ad]Ar)_3 (Ad = 1-adamantyl, Ar = 3,5-C_6H_3Me_2) are presented. The complex is found to react with dinitrogen (1 atm, THF, 25 °C) in the presence of sodium amalgam to give the dinitrogen anion complex [(THF)xNa][(N_2)Mo(N[Ad]Ar)_3]; the synthesis does not require careful regulation of the Mo(N[Ad]Ar)_3 concentration. Indeed, under no conditions has Mo(N[Ad]Ar)_3 been observed to split dinitrogen or to give rise to a dinuclear μ-N_2 complex; this striking contrast with the reactivity of Mo(N[R]Ar)_3 (R = C(CD_3)_2CH_3) is attributed to the enhanced steric protection at Mo afforded by the 1-adamantyl substituents

Group interventions to improve health outcomes : a framework for their design and delivery

Peer reviewedPublisher PD

Cloning and heterologous expression of bovine pyroglutamyl peptidase type-1 in Escherichia coli : purification , biochemical and kinetic characterisation

We describe the cloning, expression and purification of the bovine XM866409 form of pyroglutamyl-aminopeptidase I. The amino acid sequence, deduced from the nucleotide sequence, revealed that it consists of 209 amino acid residues and showed to have 98% homology with the human AJ278828 form of the enzyme. Three amino acid residues at positions 81, 205 and 208 were found to vary among the two sequences. The bovine enzyme was expressed in XL10-gold Esherichia coli cells. Immobilizied Ni-ion affinity chromatography was used to purify the expressed protein resulting in a yield of 3.3mg of PAP1 per litre culture. The purified enzyme had a specific activity of 1700 units/ml. SDS-PAGE produced a single band for bovine PAP1 with a molecular weight of ~23-24 kDa which is in good agreement with previously reported data on PAP1. Kinetic constants Km and Kcat were 59μΜ and 3.5s-1, respectively. It possessed an optimum pH between 9-9.5, a temperature of 37°C and showed an absolute requirement for a thiol-reducing agent (10mM DTT). EDTA didn’t prove to have an effect on enzyme activity. Competitive inhibition was seen with pyroglutamyl peptides pGlu-His-Pro-NH2 (TRH; Ki= 44.1 uM), pGlu-Ala- OH (Ki=141 uM) and pGlu-Val-OH (Ki=652.17)

Polypeptide-grafted macroporous polyHIPE by surface-initiated N-Carboxyanhydride (NCA) polymerization as a platform for bioconjugation

A new class of functional macroporous monoliths from polymerized high internal phase emulsion (polyHIPE) with tunable surface functional groups was developed by direct polypeptide surface grafting. In the first step, amino-functional polyHIPEs were obtained by the addition of 4-vinylbenzyl or 4-vinylbenzylphthalimide to the styrenic emulsion and thermal radical polymerization. The obtained monoliths present the expected open-cell morphology and a high surface area. The incorporated amino group was successfully utilized to initiate the ring-opening polymer- ization of benzyl-L-glutamate N-carboxyanhydride (BLG NCA) and benzyloxycarbonyl-L-lysine (Lys(Z)) NCA, which resulted in a dense homogeneous coating of polypeptides throughout the internal polyHIPE surfaces as confirmed by SEM and FTIR analysis. The amount of polypeptide grafted to the polyHIPE surfaces could be modulated by varying the initial ratio of amino acid NCA to amino-functional polyHIPE. Subsequent removal of the polypeptide protecting groups yielded highly functional polyHIPE-g-poly(glutamic acid) and polyHIPE-g- poly(lysine). Both types of polypeptide-grafted monoliths responded to pH by changes in their hydrohilicity. The possibility to use the high density of function (−COOH or −NH2) for secondary reaction was demonstrated by the successful bioconjugation of enhanced green fluorescent protein (eGFP) and fluorescein isocyanate (FITC) on the polymer 3D-scaffold surface. The amount of eGFP and FITC conjugated to the polypeptide-grafted polyHIPE was significantly higher than to the amino- functional polyHIPE, signifying the advantage of polypeptide grafting to achieve highly functional polyHIPEs

Inclusive education for deaf students: literacy practices and South African sign language

This is an Accepted Manuscript of an article published by Taylor & Francis in Southern African Linguistics and Applied Language Studies on 16 July 2012, available online: http://www.tandfonline.com/10.2989/16073614.2012.693707.This article considers the feasibility of inclusive education for Deaf students in a mainstream Further Education and Training (FET) classroom through the use of a South African Sign Language interpreter. It revisits the centrality of language in Deaf students' education and reports on progressive policy changes in the areas of language, education and disability in South Africa. The article surveys classroom discourse and literacy practices in a mainstream FET classroom, focusing particularly on students' acquisition of text literacy skills in Business English. Drawing on theoretical frameworks from the New Literacy Studies, Critical Discourse Analysis and the Social Model of Disability, the article argues that there is definitely potential for establishing inclusive education for Deaf students in a mainstream classroom. It however highlights that there are many difficulties and challenges around providing fully inclusive education for Deaf students. It was found that the signed interpretations in this classroom frequently represent an impoverished form of language while some types of pedagogic practice impede the interpreter's signing. The article concludes that interpreters and teachers need to be trained in forms of language and pedagogy that would benefit all students in class, including Deaf students