1,159 research outputs found
Genomic Profiling Reveals Distinct Routes To Complement Resistance in Klebsiella pneumoniae.
The serum complement system is a first line of defense against bacterial invaders. Resistance to killing by serum enhances the capacity of Klebsiella pneumoniae to cause infection, but it is an incompletely understood virulence trait. Identifying and characterizing the factors responsible for preventing activation of, and killing by, serum complement could inform new approaches to treatment of K. pneumoniae infections. Here, we used functional genomic profiling to define the genetic basis of complement resistance in four diverse serum-resistant K. pneumoniae strains (NTUH-K2044, B5055, ATCC 43816, and RH201207), and explored their recognition by key complement components. More than 90 genes contributed to resistance in one or more strains, but only three, rfaH, lpp, and arnD, were common to all four strains. Deletion of the antiterminator rfaH, which controls the expression of capsule and O side chains, resulted in dramatic complement resistance reductions in all strains. The murein lipoprotein gene lpp promoted capsule retention through a mechanism dependent on its C-terminal lysine residue; its deletion led to modest reductions in complement resistance. Binding experiments with the complement components C3b and C5b-9 showed that the underlying mechanism of evasion varied in the four strains: B5055 and NTUH-K2044 appeared to bypass recognition by complement entirely, while ATCC 43816 and RH201207 were able to resist killing despite being associated with substantial levels of C5b-9. All rfaH and lpp mutants bound C3b and C5b-9 in large quantities. Our findings show that, even among this small selection of isolates, K. pneumoniae adopts differing mechanisms and utilizes distinct gene sets to avoid complement attack
The Genome of Streptococcus mitis B6 - What Is a Commensal?
Streptococcus mitis is the closest relative of the major human pathogen S. pneumoniae. The 2,15 Mb sequence of the Streptococcus mitis B6 chromosome, an unusually high-level beta-lactam resistant and multiple antibiotic resistant strain, has now been determined to encode 2100 genes. The accessory genome is estimated to represent over 40%, including 75 mostly novel transposases and IS, the prophage φB6 and another seven phage related regions. Tetracycline resistance mediated by Tn5801, and an unusual and large gene cluster containing three aminoglycoside resistance determinants have not been described in other Streptococcus spp. Comparative genomic analyses including hybridization experiments on a S. mitis B6 specific microarray reveal that individual S. mitis strains are almost as distantly related to the B6 strain as S. pneumoniae. Both species share a core of over 900 genes. Most proteins described as pneumococcal virulence factors are present in S. mitis B6, but the three choline binding proteins PcpA, PspA and PspC, and three gene clusters containing the hyaluronidase gene, ply and lytA, and the capsular genes are absent in S. mitis B6 and other S. mitis as well and confirm their importance for the pathogenetic potential of S. pneumoniae. Despite the close relatedness between the two species, the S. mitis B6 genome reveals a striking X-alignment when compared with S. pneumoniae
Intermittent Fasting Exacerbates the Acute Immune and Behavioral Sickness Response to the Viral Mimic Poly(I:C) in Mice
Intermitted fasting and other forms of calorie restriction are increasingly demonstrated to exert potential health benefits. Interestingly, restricted feeding is also able to mitigate sickness in response to bacterial factors stimulating Toll-like receptor 4 (TLR4). However, little is known about how fasting modifies the activity of virus-associated molecular patterns. We therefore analyzed the impact of an intermittent fasting (IF) regimen on the immune and behavioral response to the TLR3 agonist and viral mimic polyinosinic:polycytidylic acid [Poly(I:C)] in mice. The effects of intraperitoneally injected Poly(I:C) (12 mg/kg) on plasma and cerebral cytokine expression and behavior (locomotion, exploration, and ingestion) were examined in male C57BL/6N mice under control conditions and following a 9 days period of intermittent (alternate day) fasting (IF). Poly(I:C) increased the circulating levels of cytokines (TNF-α, MCP-1, IL-6, IL-10, IFN-α, IFN-γ), an effect amplified by IF. In addition, IF aggravated sickness behavior in response to Poly(I:C), while cerebral cytokine expression was enhanced by application of Poly(I:C) in the absence of a significant effect of IF. Furthermore, IF augmented the expression of neuropeptide Y (NPY) mRNA in the hypothalamus and increased the plasma levels of corticosterone, while Poly(I:C) had little effect on these readouts. Our data show that IF does not abate, but exaggerates the immune and sickness response to the viral mimic Poly(I:C). This adverse effect of IF occurs despite increased hypothalamic NPY expression and enhanced plasma corticosterone. We therefore propose that the effects of IF on the immune and behavioral responses to viral and bacterial factors are subject to different neuronal and neuroendocrine control mechanisms
Ocorrência de doenças oftalmológicas em eqüinos utilizados para tração urbana na cidade de Londrina, PR
Ocorrência de anticorpos contra Leptospira spp. em eqüinos de área urbana de Londrina, Paraná, Brasil
A total of 320 horses were studied in this paper, both male and female, between two and 17 years of age, which were used for traction of wagons in the urban area of the municipality of Londrina (PR). These animals were kept, after their daily work, in abandoned areas or plots, in the outskirts of the urban area of the city. When these animals were attended by the veterinarians, between 1996 and 2005, none of them presented symptoms suggesting leptospirosis. The most frequent reasons for the visit were loss of weight, unwillingness for work, parasitism, laminess, and wounds. Microscopic Seroagglutination Test (SAM), with 22 Leptospira serovars, was performed in sera sample from all these animals. The aim of this study was to investigate the occurrence of antibodies against Leptospira spp. in horses from the urban area of Londrina (PR). From the samples tested, 214 (66.88%) were considered positive, with titers between 100 and 3200, being that 49 (22.90%) presented antibodies against a single serovar of Leptospira, and 165 (77.10%) samples presented antibodies against two or more serovars simultaneously, where in 88 (53.33%) it was possible to characterize the most likely probable serovar. Antibodies against the serovar Icterohaemorrhagiae were detected in 32 (23.36%) animals.Foram estudados 320 eqĂĽinos, machos e fĂŞmeas com idade entre dois a 17 anos, utilizados para tração de carroças na área urbana do municĂpio de Londrina (PR). Estes animais eram mantidos, apĂłs a jornada diária de serviço, em áreas ou terrenos baldios, localizados na periferia da área urbana do municĂpio. Por ocasiĂŁo do atendimento, realizado entre 1996 e 2005, no Hospital Veterinário da Universidade Estadual de Londrina, nenhum dos animais apresentou sintomas sugestivos de leptospirose, sendo os motivos mais freqĂĽentes, o emagrecimento, a indisposição para o trabalho, a verminose, problemas no sistema locomotor e feridas. A prova de soroaglutinação microscĂłpica (SAM), com 22 sorovares de Leptospira, foi realizada em amostra de soro de todos os animais. O objetivo deste trabalho foi investigar a ocorrĂŞncia de anticorpos contra Leptospira spp. em eqĂĽinos da área urbana do municĂpio de Londrina. Foram consideradas positivas 214 (66,88%) amostras de soros com tĂtulos entre 100 e 3200, sendo em 49 (22,90%) detectadas anticorpos contra um Ăşnico sorovar de Leptospira e em 165 (77,10%) amostras com anticorpos contra dois ou mais sorovares simultâneamente, sendo em 88 (53,33%) destes caracterizado o sorovar mais provável. Anticorpos contra o sorovar Icterohaemorrhagiae foram detectados em 32 (23,36%) animais
Frequency of median mononeuropathy in patients with mild diabetic neuropathy in the early diabetes intervention trial (EDIT)
We used electrophysiologic criteria to identify median mononeuropathy (MM) of the nondominant wrist among 414 patients enrolled in a multicenter study of patients with mild diabetic neuropathy, according to consensus recommendations. Patients with absent sural or peroneal responses or greater than mild symptoms of carpal tunnel syndrome were ineligible. Ninety-five of 414 participants (23%) fulfilled criteria for MM, independent of diabetes type. Patients with MM had a longer duration of diabetes than remaining patients, independent of age, and patients with MM and type II diabetes were more likely to be female (34% vs. 19%; P = 0.008), shorter (165.7 vs. 172.7 cm; P = 0.001), and have a higher body mass index (32.5 vs. 29.1; P = 0.0008) than remaining type II patients. Sural or peroneal conduction abnormalities did not influence the frequency of MM. These results suggest that patients with diabetic neuropathy require special consideration with regard to the evaluation of suspected carpal tunnel syndrome. © 1996 John Wiley & Sons, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50167/1/3_ftp.pd
Levodopa therapy in Parkinson’s disease: Influence on liquid chromatographic tandem mass spectrometricbased measurements of plasma and urinary normetanephrine, metanephrine and methoxytyramine
Background: Medication-related interferences with measurements of catecholamines and their metabolites represent important causes of false-positive results during diagnosis of phaeochromocytomas and paragangliomas (PPGLs). Such interferences are less troublesome with measurements by liquid chromatography with tandem mass-spectrometry (LC-MS/MS) than by other methods, but can still present problems for some drugs. Levodopa, the precursor for dopamine used in the treatment of Parkinson’s disease, represents one potentially interfering medication. Methods: Plasma and urine samples, obtained from 20 Parkinsonian patients receiving levodopa, were analysed for concentrations of catecholamines and their O-methylated metabolites by LC-MS/MS. Results were compared with those from a group of 120 age-matched subjects and 18 patients with PPGLs. Results: Plasma and urinary free and deconjugated (freeþconjugated) methoxytyramine, as well as urinary dopamine, showed 22- to 148-fold higher (P<0.0001) concentrations in patients receiving levodopa than in the reference group. In contrast, plasma normetanephrine, urinary noradrenaline and urinary free and deconjugated normetanephrine concentrations were unaffected. Plasma free metanephrine, urinary adrenaline and urinary free and deconjugated metanephrine all showed higher (P<0.05) concentrations in Parkinsonian patients than the reference group, but this was only a problem for adrenaline. Similar to normetanephrine, plasma and urinary metanephrine remained below the 97.5 percentiles of the reference group in almost all Parkinsonian patients. Conclusions: These data establish that although levodopa treatment confounds identification of PPGLs that produce dopamine, the therapy is not a problem for use of LC-MS/MS measurements of plasma and urinary normetanephrine and metanephrine to diagnose more commonly encountered PPGLs that produce noradrenaline or adrenaline
Pathophysiological Changes in the Enteric Nervous System of Rotenone-Exposed Mice as Early Radiological Markers for Parkinson's Disease
Parkinson's disease (PD) is known to involve the peripheral nervous system (PNS) and the enteric nervous system (ENS). Functional changes in PNS and ENS appear early in the course of the disease and are responsible for some of the non-motor symptoms observed in PD patients like constipation, that can precede the appearance of motor symptoms by years. Here we analyzed the effect of the pesticide rotenone, a mitochondrial Complex I inhibitor, on the function and neuronal composition of the ENS by measuring intestinal contractility in a tissue bath and by analyzing related protein expression. Our results show that rotenone changes the normal physiological response of the intestine to carbachol, dopamine and electric field stimulation (EFS). Changes in the reaction to EFS seem to be related to the reduction in the cholinergic input but also related to the noradrenergic input, as suggested by the non-adrenergic non-cholinergic (NANC) reaction to the EFS in rotenone-exposed mice. The magnitude and direction of these alterations varies between intestinal regions and exposure times and is associated with an early up-regulation of dopaminergic, cholinergic and adrenergic receptors and an irregular reduction in the amount of enteric neurons in rotenone-exposed mice. The early appearance of these alterations, that start occurring before the substantia nigra is affected in this mouse model, suggests that these alterations could be also observed in patients before the onset of motor symptoms and makes them ideal potential candidates to be used as radiological markers for the detection of Parkinson's disease in its early stages
Anti-Tumor Necrosis Factor α Therapeutics Differentially Affect Leishmania Infection of Human Macrophages
Tumor necrosis factor α (TNFα) drives the pathophysiology of human autoimmune diseases and consequently, neutralizing antibodies (Abs) or Ab-derived molecules directed against TNFα are essential therapeutics. As treatment with several TNFα blockers has been reported to entail a higher risk of infectious diseases such as leishmaniasis, we established an in vitro model based on Leishmania-infected human macrophages, co-cultured with autologous T-cells, for the analysis and comparison of anti-TNFα therapeutics. We demonstrate that neutralization of soluble TNFα (sTNFα) by the anti-TNFα Abs Humira®, Remicade®, and its biosimilar Remsima® negatively affects infection as treatment with these agents significantly reduces Leishmania-induced T-cell proliferation and increases the number of infected macrophages. By contrast, we show that blockade of sTNFα by Cimzia® does not affect T-cell proliferation and infection rates. Moreover, compared to Remicade®, treatment with Cimzia® does not impair the expression of cytolytic effector proteins in proliferating T-cells. Our data demonstrate that Cimzia® supports parasite control through its conjugated polyethylene glycol (PEG) moiety as PEGylation of Remicade® improves the clearance of intracellular Leishmania. This effect can be linked to complement activation, with levels of complement component C5a being increased upon treatment with Cimzia® or a PEGylated form of Remicade®. Taken together, we provide an in vitro model of human leishmaniasis that allows direct comparison of different anti-TNFα agents. Our results enhance the understanding of the efficacy and adverse effects of TNFα blockers and they contribute to evaluate anti-TNFα therapy for patients living in countries with a high prevalence of leishmaniasis
Empfehlungen fĂĽr eine nationale Open Science Strategie in Ă–sterreich / Recommendations for a National Open Science Strategy in Austria
A look at international activities on Open Science reveals a broad spectrum from individual institutional policies to national action plans. The present Recommendations for a National Open Science Strategy in Austria are based on these international initiatives and present practical considerations for their coordinated implementation with regard to strategic developments in research, technology and innovation (RTI) in Austria until 2030. They are addressed to all relevant actors in the RTI system, in particular to Research Performing Organisations, Research Funding Organisations, Research Policy, memory institutions such as Libraries and Researchers. The recommendation paper was developed from 2018 to 2020 by the OANA working group "Open Science Strategy" and published for the first time in spring 2020 for a public consultation. The now available final version of the recommendation document, which contains feedback and comments from the consultation, is intended to provide an impetus for further discussion and implementation of Open Science in Austria and serves as a contribution and basis for a potential national Open Science Strategy in Austria. The document builds on the diverse expertise of the authors (academia, administration, library and archive, information technology, science policy, funding system, etc.) and reflects their personal experiences and opinions.Der Blick auf internationale Aktivitäten zu Open Science zeigt ein breites Spektrum von einzelnen institutionellen Policies bis hin zu nationalen Aktionsplänen. Die vorliegenden Empfehlungen für eine nationale Open Science Strategie in Österreich orientieren sich an diesen internationalen Initiativen und stellen praktische Überlegungen für ihre koordinierte Implementierung im Hinblick auf strategische Entwicklungen in Forschung, Technologie und Innovation (FTI) bis 2030 in Österreich dar. Dabei richten sie sich an alle relevanten Akteur*innen im FTI System, im Besonderen an Forschungsstätten, Forschungsförderer, Forschungspolitik, Gedächtnisinstitutionen wie Bibliotheken und Wissenschafter*innen. Das Empfehlungspapier wurde von 2018 bis 2020 von der OANA-Arbeitsgruppe "Open Science Strategie" entwickelt und im Frühling 2020 das erste Mal für eine öffentliche Konsultation veröffentlicht. Die nun vorliegende finale Version des Empfehlungsdokuments, die Feedback und Kommentare aus der Konsultation enthält, soll ein Anstoß für die weitere Diskussion und Umsetzung von Open Science in Österreich sein und als Beitrag und Grundlage einer potentiellen nationalen Open Science Strategie in Österreich dienen. Das Dokument baut auf der vielfältigen Expertise der Autor*innen auf (Wissenschaft, Administration, Bibliothek und Archiv, Informationstechnologie, Wissenschaftspolitik, Förderwesen etc.) und spiegelt deren persönliche Erfahrungen und Meinung wider
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