Summary Streptomyces scabies is one of a group of organisms that causes the economically important disease potato scab. Analysis of the S. scabies genome sequence indicates that it is likely to secrete many proteins via the twin arginine protein transport (Tat) pathway, including several proteins whose coding sequences may have been acquired through horizontal gene transfer and share a common ancestor with proteins in other plant pathogens.
View Article and Find Full Text PDFAuthors present a case of an 83 years old female, who suddenly became unconscious and had seizures, during bowel preparation for colonoscopy, but before taking the sodium phosphate purgative. Laboratory investigations revealed severe hyponatremia. Hypertonic saline infusion was administered, the electrolyte disturbance returned to normal, the patient slowly regained her consciousness and her disorientation started to improve gradually.
View Article and Find Full Text PDFA multicommuted flow system with the propulsion device placed before detection is proposed for the determination of tartaric acid and free potassium in table and Port wines. A dialysis unit was introduced to increase sample dilution and minimize matrix interferences. The determination of tartaric acid was based on the spectrophotometric monitorization of the complex formed by the dialyzed analyte with vanadate.
View Article and Find Full Text PDFA novel class of thymine, adenine and lipoamino acid based non-viral carriers for gene delivery has been developed. Their ability to bind to DNA by hydrogen bonding was confirmed by NMR diffusion, isothermal titration calorimetry and transmission electron microscopy experiments.
View Article and Find Full Text PDFThe conformational properties of lanthanide(III) complexes with the mono- and biphosphonate analogues of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate (DOTA) are investigated by means of density functional theory (DFT) calculations and NMR spectroscopy. Geometry optimizations performed at the B3LYP/6-31G(d) level and using a 46 + 4f(n) effective core potential for lanthanides provide two energy minima corresponding to the square-antiprismatic (SAP) and twisted square-antiprismatic (TSAP) geometries. Our calculations give relative free energies between the SAP and TSAP isomers in fairly good agreement with the experimental values.
View Article and Find Full Text PDFPantoea ananatis is a Gram-negative plant pathogen that causes disease on a broad range of host plants, including pineapple, maize, rice, onion, melons, and Eucalyptus, and has been implicated in several cases of human disease. Here, we report the genome sequence of P. ananatis LMG20103 isolated from diseased Eucalyptus in South Africa.
View Article and Find Full Text PDFThe nasal route as a site of vaccine delivery for both local and systemic effect is currently of considerable interest. The administration of vaccines to mucosal surfaces such as the nasopharynx associated lymphoid tissues confers many advantages since the nasal mucosa is a primary site through which most inhaled antigens are encountered. However, the success of intranasally delivered mucosal vaccines is limited by lack of effective vaccine formulations or delivery systems suitable for use in humans.
View Article and Find Full Text PDFHorseradish peroxidase (HRP) has been broadly used and investigated for many analytical purposes; it is an enzyme that catalyzes the reduction of hydrogen peroxide in the presence of a reducing compound. The objective of this work was to develop a methodology for the spectrophotometric determination of the activity of peroxidase in vegetable extracts using a flow method with a sequential injection lab-on-valve format. The developed system is based on the reaction between hydrogen peroxide (H(2)O(2)) and 2,2-azinobis(3-ethylbenzothiazoline-6)sulfonic acid (ABTS) catalyzed by the enzyme (HRP).
View Article and Find Full Text PDFResearch related to peptide, vaccine, and gene delivery has grown exponentially over the last decade. In this review, we discuss the development of delivery systems for peptides, gene and vaccine products. Special focus is given to different lipidation and glycosylation strategies to improve the metabolic stability and membrane permeability of therapeutics, and their targeting to specific sites.
View Article and Find Full Text PDFEur J Clin Microbiol Infect Dis
February 2010
The purpose of this study was to characterise verotoxigenic Escherichia coli (VTEC) strains isolated in Hungary from 2000 to 2006. Altogether, 33 human VTEC strains were investigated to define the O:H antigens, verotoxin 1, 2 (vtx1 and 2), intimin (eae), enteroaggregative heat-stable toxin (ast1), autoagglutinating adhesin (saa) and enterohaemolysin (ehlyA) genes and sensitivity to 11 antimicrobial agents. The strains belonged to 14 different O:H serotypes, among which O157:NM (non-motile) was the most prevalent (45%, 15/33).
View Article and Find Full Text PDFA variety of functional polymer chains prepared by RAFT were directly grafted onto 5, 10, and 20 nm gold nanoparticles (AuNPs). The polymer shell coating the AuNPs was densely packed because of the strong binding between the trithioester groups on the polymer chain-ends and gold. It was found that due to the densely packed nature of the shell the polymer chains were significantly stretched compared to their usual Gaussian coil conformation in water.
View Article and Find Full Text PDFObjectives: Oral lichen planus (OLP) is a chronic inflammatory disease of the oral mucosa. Its etiology is still unclear. Neurogenic components might contribute to the inflammatory process.
View Article and Find Full Text PDFOral delivery of hydrophilic, ionisable drugs remains a major challenge in drug development and a number of active pharmaceuticals fail to reach the market of oral drugs because of a lack of absorption and/or stability issues. One possible approach to improving the bioavailability of such drug candidates is to increase their lipophilicity, which is a key parameter in the permeation across cell membranes. However, modifying the chemical structure by adding lipid residues often results in changes in activity.
View Article and Find Full Text PDFOne of the factors responsible for the poor immunogenicity of synthetic peptide antigens is the lack of conformational integrity. Embedding the minimal epitopes in helix-promoting peptide sequences has successfully enhanced the immunogenicity of the epitopes derived from the alpha-helical regions of the M protein of group A streptococci (Streptococcus pyogenes, GAS). However, the introduction of "foreign" peptide sequences is believed to have an unfavourable impact on the antigen specificity.
View Article and Find Full Text PDFJasmonate is a key signalling compound in plant defence that is synthesized in wounded tissues. In this work, we have found that this molecule is also a strong chemoattractant for the phythopathogenic bacteria Dickeya dadantii (ex-Erwinia chysanthemi). Jasmonic acid induced the expression of a subset of bacterial genes possibly involved in virulence/survival in the plant apoplast and bacterial cells pre-treated with jasmonate showed increased virulence in chicory and Saintpaulia leaves.
View Article and Find Full Text PDFThe lipid core peptide (LCP) is a novel, synthetic, self-adjuvanted vaccine delivery system that neatly incorporates the adjuvant, carrier and antigenic peptides of a vaccine into a single molecular entity. This system has been previously shown to efficiently deliver vaccines and induce immunity. Because adjuvants target sentinels of the immune response, such as dendritic cells (DCs), that are widely distributed throughout the body to initiate specific immune responses, we investigated the effects of the adjuvant on DCs.
View Article and Find Full Text PDFThe stoichiometries and stability constants of a series of Al(3+)-N-phosponomethyl glycine (PMG/H(3)L) complexes have been determined in acidic aqueous solution using a combination of precise potentiometric titration data, quantitative (27)Al and (31)P NMR spectra, ATR-FTIR spectrum and ESI-MS measurements (0.6M NaCl, 25 degrees C). Besides the mononuclear AlH(2)L(2+), Al(H(2)L)(HL), Al(HL)(2)(-) and Al(HL)L(2-), dimeric Al(2)(HL)L(+) and trinuclear Al(3)H(5)L(4)(2+) complexes have been postulated.
View Article and Find Full Text PDFInt J Food Microbiol
October 2009
The aim of this work was to investigate the effect of phenolic acids on cell membrane permeability of lactic acid bacteria from wine. Several phenolic acids were tested for their effects on the cell membrane of Oenococcus oeni and Lactobacillus hilgardii by measuring potassium and phosphate efflux, proton influx and by assessing culture viability employing a fluorescence technique based on membrane integrity. The experimental results indicate that hydroxycinnamic acids (p-coumaric, caffeic and ferulic acids) induce greater ion leakages and higher proton influx than hydroxybenzoic acids (p-hydroxibenzoic, protocatechuic, gallic, vanillic, and syringic acids).
View Article and Find Full Text PDFMicroarray comparative genomic hybridisation (aCGH) provides an estimate of the relative abundance of genomic DNA (gDNA) taken from comparator and reference organisms by hybridisation to a microarray containing probes that represent sequences from the reference organism. The experimental method is used in a number of biological applications, including the detection of human chromosomal aberrations, and in comparative genomic analysis of bacterial strains, but optimisation of the analysis is desirable in each problem domain.We present a method for analysis of bacterial aCGH data that encodes spatial information from the reference genome in a hidden Markov model.
View Article and Find Full Text PDFCharacterization of an Escherichia coli O157 strain collection (n = 42) derived from healthy Hungarian cattle revealed the existence of diverse pathotypes. Enteropathogenic E. coli (EPEC; eae positive) appeared to be the most frequent pathotype (n = 22 strains), 11 O157 strains were typical enterohemorrhagic E.
View Article and Find Full Text PDF17beta-Oxazolinyl steroids 7a-g and 8a-g were synthesized. The Lewis acid-catalysed reactions of (20R)-3beta-acetoxy-21-azidomethyl-20-hydroxypregn-5-ene with substituted aromatic aldehydes led to the formation of 3beta-acetoxyandrost-5-enes substituted in position 17beta with oxazolinyl residues (7a-g). Oppenauer oxidation of the 3beta-hydroxy-exo-heterocyclic steroids yielded the corresponding Delta(4)-3-ketosteroids.
View Article and Find Full Text PDFGene delivery research has come a long way in recent years but there are still a number of barriers preventing therapeutic gene-based drugs reaching the market. Dendrimers or multi-component carriers may provide a means to overcome the issues of gene degradation and transport to the target site by employing different entities in the same carrier. We will discuss some recent approaches to gene delivery using modified dendrimers.
View Article and Find Full Text PDFAlthough most commercial vaccines are delivered by injection, there is an increasing interest in needle-free vaccine delivery for reasons including the ability to elicit immune responses at mucosal surfaces, ease of administration, and the ability to administer vaccines without the need for trained medical professionals. This review summarizes strategies and technologies that are being used to improve oral vaccine absorption. Peptides and proteins, which comprise important vaccine components, exhibit unfavorable physicochemical properties including degradation in the gastrointestinal tract, and poor transport across the intestinal wall, which hinder oral vaccine development.
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