Plant response to biotic stress: Is there a common epigenetic response during plant-pathogenic and symbiotic interactions?

Science.gov (United States)

Zogli, Prince; Libault, Marc

2017-10-01

Plants constantly interact with pathogenic and symbiotic microorganisms. Recent studies have revealed several regulatory mechanisms controlling these interactions. Among them, the plant defense system is activated not only in response to pathogenic, but also in response to symbiotic microbes. Interestingly, shortly after symbiotic microbial recognition, the plant defense system is suppressed to promote plant infection by symbionts. Research studies have demonstrated the influence of the plant epigenome in modulating both pathogenic and symbiotic plant-microbe interactions, thereby influencing plant survival, adaptation and evolution of the plant response to microbial infections. It is however unclear if plant pathogenic and symbiotic responses share similar epigenomic profiles or if epigenomic changes differentially regulate plant-microbe symbiosis and pathogenesis. In this mini-review, we provide an update of the current knowledge of epigenomic control on plant immune responses and symbiosis, with a special attention being paid to knowledge gap and potential strategies to fill-in the missing links. Copyright © 2017 Elsevier B.V. All rights reserved.

Antibody-independent mechanisms regulate the establishment of chronic Plasmodium infection

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Lin, Jingwen; Cunningham, Deirdre; Tumwine, Irene; Kushinga, Garikai; McLaughlin, Sarah; Spence, Philip; Böhme, Ulrike; Sanders, Mandy; Conteh, Solomon; Bushell, Ellen; Metcalf, Tom; Billker, Oliver; Duffy, Patrick E.; Newbold, Chris; Berriman, Matthew; Langhorne, Jean

2017-01-01

Malaria is caused by parasites of the genus Plasmodium. All human-infecting Plasmodium species can establish long-lasting chronic infections1–5, creating an infectious reservoir to sustain transmission1,6. It is widely accepted that maintenance of chronic infection involves evasion of adaptive immunity by antigenic variation7. However, genes involved in this process have been identified in only two of five human-infecting species: P. falciparum and P. knowlesi. Furthermore, little is understood about the early events in establishment of chronic infection in these species. Using a rodent model we demonstrate that only a minority of parasites from among the infecting population, expressing one of several clusters of virulence-associated pir genes, establishes a chronic infection. This process occurs in different species of parasite and in different hosts. Establishment of chronicity is independent of adaptive immunity and therefore different from the mechanism proposed for maintainance of chronic P. falciparum infections7–9. Furthermore, we show that the proportions of parasites expressing different types of pir genes regulate the time taken to establish a chronic infection. Since pir genes are common to most, if not all, species of Plasmodium10, this process may be a common way of regulating the establishment of chronic infections. PMID:28165471

Symbiotic Cognitive Computing

OpenAIRE

Farrell, Robert G.; Lenchner, Jonathan; Kephjart, Jeffrey O.; Webb, Alan M.; Muller, MIchael J.; Erikson, Thomas D.; Melville, David O.; Bellamy, Rachel K.E.; Gruen, Daniel M.; Connell, Jonathan H.; Soroker, Danny; Aaron, Andy; Trewin, Shari M.; Ashoori, Maryam; Ellis, Jason B.

2016-01-01

IBM Research is engaged in a research program in symbiotic cognitive computing to investigate how to embed cognitive computing in physical spaces. This article proposes 5 key principles of symbiotic cognitive computing.  We describe how these principles are applied in a particular symbiotic cognitive computing environment and in an illustrative application.  

Chronic mucus hypersecretion in COPD and death from pulmonary infection

DEFF Research Database (Denmark)

Prescott, E; Lange, P; Vestbo, J

1995-01-01

The association of chronic mucus hypersecretion and mortality is a matter of debate. We wished to determine whether the relationship between chronic mucus hypersecretion and chronic obstructive pulmonary disease (COPD)-related mortality could be explained by proneness to pulmonary infection. We...... with pulmonary infection implicated (relative risk (RR) 3.5) but not of death without pulmonary infection (RR 0.9). We consider that subjects with COPD and chronic mucus hypersecretion are more likely to die from pulmonary infections than subjects without chronic mucus hypersecretion. This may explain the excess...... radiography, death was classified as either due to pulmonary infection (n = 38), other causes (n = 51), or unclassifiable (n = 12). Of subjects reporting chronic mucus hypersecretion at the initial examination, pulmonary infection was implicated in 54% of deaths, whereas this only occurred in 28% of subjects...

Biofilms in chronic infections - a matter of opportunity - monospecies biofilms in multispecies infections

DEFF Research Database (Denmark)

Burmølle, Mette; Thomsen, Trine Rolighed; Fazli, Mustafa

2010-01-01

It has become evident that aggregation or biofilm formation is an important survival mechanism for bacteria in almost any environment. In this review, we summarize recent visualizations of bacterial aggregates in several chronic infections (chronic otitis media, cystic fibrosis, infection due...... to permanent tissue fillers and chronic wounds) both as to distribution (such as where in the wound bed) and organization (monospecies or multispecies microcolonies). We correlate these biofilm observations to observations of commensal biofilms (dental and intestine) and biofilms in natural ecosystems (soil......). The observations of the chronic biofilm infections point toward a trend of low bacterial diversity and sovereign monospecies biofilm aggregates even though the infection in which they reside are multispecies. In contrast to this, commensal and natural biofilm aggregates contain multiple species that are believed...

Diagnosis and understanding of chronic biofilm infections

DEFF Research Database (Denmark)

Thomsen, Trine Rolighed

2016-01-01

Title: Diagnosis and understanding of chronic biofilm infections. Name: Trine Rolighed Thomsen Aalborg University and Danish Technological Institute, Denmark Recent evidence suggests that the microbial community, its spatial distribution and activity play an important role in the prolongation......, anaerobic or unculturable bacteria living in biofilms. Thus, diagnosis of chronic infections is challenged by lack of appropriate sampling strategies and by limitations in microbiological testing methods. The purpose of this study was to improve sampling and diagnosis of chronic infections, especially...... considering the biofilm issue. Systematic and optimized sampling of various specimen types was performed. Extended culture, optimized DNA extraction, quantitative PCR, cloning, next generation sequencing and PNA FISH were applied on different types of specimens for optimized diagnosis. For further...

Nodulation outer proteins: double-edged swords of symbiotic rhizobia.

Science.gov (United States)

Staehelin, Christian; Krishnan, Hari B

2015-09-15

Rhizobia are nitrogen-fixing bacteria that establish a nodule symbiosis with legumes. Nodule formation depends on signals and surface determinants produced by both symbiotic partners. Among them, rhizobial Nops (nodulation outer proteins) play a crucial symbiotic role in many strain-host combinations. Nops are defined as proteins secreted via a rhizobial T3SS (type III secretion system). Functional T3SSs have been characterized in many rhizobial strains. Nops have been identified using various genetic, biochemical, proteomic, genomic and experimental approaches. Certain Nops represent extracellular components of the T3SS, which are visible in electron micrographs as bacterial surface appendages called T3 (type III) pili. Other Nops are T3 effector proteins that can be translocated into plant cells. Rhizobial T3 effectors manipulate cellular processes in host cells to suppress plant defence responses against rhizobia and to promote symbiosis-related processes. Accordingly, mutant strains deficient in synthesis or secretion of T3 effectors show reduced symbiotic properties on certain host plants. On the other hand, direct or indirect recognition of T3 effectors by plant cells expressing specific R (resistance) proteins can result in effector triggered defence responses that negatively affect rhizobial infection. Hence Nops are double-edged swords that may promote establishment of symbiosis with one legume (symbiotic factors) and impair symbiotic processes when bacteria are inoculated on another legume species (asymbiotic factors). In the present review, we provide an overview of our current understanding of Nops. We summarize their symbiotic effects, their biochemical properties and their possible modes of action. Finally, we discuss future perspectives in the field of T3 effector research. © 2015 Authors; published by Portland Press Limited.

Primary peak and chronic malaria infection levels are correlated in experimentally infected great reed warblers.

Science.gov (United States)

Asghar, Muhammad; Westerdahl, Helena; Zehtindjiev, Pavel; Ilieva, Mihaela; Hasselquist, Dennis; Bensch, Staffan

2012-09-01

Malaria parasites often manage to maintain an infection for several months or years in their vertebrate hosts. In humans, rodents and birds, most of the fitness costs associated with malaria infections are in the short initial primary (high parasitaemia) phase of the infection, whereas the chronic phase (low parasitaemia) is more benign to the host. In wild birds, malaria parasites have mainly been studied during the chronic phase of the infection. This is because the initial primary phase of infection is short in duration and infected birds with severe disease symptoms tend to hide in sheltered places and are thus rarely caught and sampled. We therefore wanted to investigate the relationship between the parasitaemia during the primary and chronic phases of the infection using an experimental infection approach. We found a significant positive correlation between parasitaemia in the primary peak and the subsequent chronic phase of infection when we experimentally infected great reed warblers (Acrocephalus arundinaceus) with Plasmodium ashfordi. The reason for this association remains to be understood, but might arise from individual variation in exoerythrocytic parasite reservoirs in hosts, parasite antigenic diversity and/or host genetics. Our results suggest that the chronic phase parasitaemia can be used to qualitatively infer the parasitaemia of the preceding and more severe primary phase, which is a very important finding for studies of avian malaria in wild populations.

Toxic effects of arsenic on Sinorhizobium-Medicago sativa symbiotic interaction

Energy Technology Data Exchange (ETDEWEB)

Pajuelo, Eloisa [Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, 41012 Seville (Spain); Rodriguez-Llorente, Ignacio D. [Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, 41012 Seville (Spain)], E-mail: irodri@us.es; Dary, Mohammed; Palomares, Antonio J. [Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, 41012 Seville (Spain)

2008-07-15

Recently, the Rhizobium-legume symbiotic interaction has been proposed as an interesting tool in bioremediation. However, little is known about the effect of most common contaminants on this process. The phytotoxic effects of arsenic on nodulation of Medicago sativa have been examined in vitro using the highly arsenic resistant and symbiotically effective Sinorhizobium sp. strain MA11. The bacteria were able to grow on plates containing As concentrations as high as 10 mM. Nevertheless, as little as 25-35 {mu}M arsenite produced a 75% decrease in the total number of nodules, due to a 90% reduction in the number of rhizobial infections, as could be determined using the strain MA11 carrying a lacZ reporter gene. This effect was associated to root hair damage and a shorter infective root zone. However, once nodulation was established nodule development seemed to continue normally, although earlier senescence could be observed in nodules of arsenic-grown plants. - First steps of nodulation of alfalfa, in particular infection thread formation, are more sensitive to As than nitrogen fixation due to plant effects.

Two closely related Rho GTPases, Cdc42 and RacA, of the en-dophytic fungus Epichloë festucae have contrasting roles for ROS production and symbiotic infection synchronized with the host plant.

Science.gov (United States)

Kayano, Yuka; Tanaka, Aiko; Takemoto, Daigo

2018-01-01

Epichloë festucae is an endophytic fungus which systemically colonizes temperate grasses to establish symbiotic associations. Maintaining symptomless infection is a key requirement for endophytes, a feature that distinguishes them from pathogenic fungi. While pathogenic fungi extend their hyphae by tip growth, hyphae of E. festucae systemically colonize the intercellular space of expanding host leaves via a unique mechanism of hyphal intercalary growth. This study reports that two homologous Rho GTPases, Cdc42 and RacA, have distinctive roles in the regulation of E. festucae growth in planta. Here we highlight the vital role of Cdc42 for intercalary hyphal growth, as well as involvement of RacA in regulation of hyphal network formation, and demonstrate the consequences of mutations in these genes on plant tissue infection. Functions of Cdc42 and RacA are mediated via interactions with BemA and NoxR respectively, which are expected components of the ROS producing NOX complex. Symbiotic defects found in the racA mutant were rescued by introduction of a Cdc42 with key amino acids substitutions crucial for RacA function, highlighting the significance of the specific interactions of these GTPases with BemA and NoxR for their functional differentiation in symbiotic infection.

Models of symbiotic stars

Science.gov (United States)

Friedjung, Michael

1993-01-01

One of the most important features of symbiotic stars is the coexistence of a cool spectral component that is apparently very similar to the spectrum of a cool giant, with at least one hot continuum, and emission lines from very different stages of ionization. The cool component dominates the infrared spectrum of S-type symbiotics; it tends to be veiled in this wavelength range by what appears to be excess emission in D-type symbiotics, this excess usually being attributed to circumstellar dust. The hot continuum (or continua) dominates the ultraviolet. X-rays have sometimes also been observed. Another important feature of symbiotic stars that needs to be explained is the variability. Different forms occur, some variability being periodic. This type of variability can, in a few cases, strongly suggest the presence of eclipses of a binary system. One of the most characteristic forms of variability is that characterizing the active phases. This basic form of variation is traditionally associated in the optical with the veiling of the cool spectrum and the disappearance of high-ionization emission lines, the latter progressively appearing (in classical cases, reappearing) later. Such spectral changes recall those of novae, but spectroscopic signatures of the high-ejection velocities observed for novae are not usually detected in symbiotic stars. However, the light curves of the 'symbiotic nova' subclass recall those of novae. We may also mention in this connection that radio observations (or, in a few cases, optical observations) of nebulae indicate ejection from symbiotic stars, with deviations from spherical symmetry. We shall give a historical overview of the proposed models for symbiotic stars and make a critical analysis in the light of the observations of symbiotic stars. We describe the empirical approach to models and use the observational data to diagnose the physical conditions in the symbiotics stars. Finally, we compare the results of this empirical

Phyllanthus species for chronic hepatitis B virus infection

DEFF Research Database (Denmark)

Yun, Xia; Luo, Hui; Liu, Jian Ping

2011-01-01

Phyllanthus species for patients with chronic hepatitis B virus (HBV) infection have been assessed in clinical trials, but no consensus regarding their usefulness exists.......Phyllanthus species for patients with chronic hepatitis B virus (HBV) infection have been assessed in clinical trials, but no consensus regarding their usefulness exists....

Comparing the bacterial diversity of acute and chronic dental root canal infections.

Directory of Open Access Journals (Sweden)

Adriana L Santos

Full Text Available This study performed barcoded multiplex pyrosequencing with a 454 FLX instrument to compare the microbiota of dental root canal infections associated with acute (symptomatic or chronic (asymptomatic apical periodontitis. Analysis of samples from 9 acute abscesses and 8 chronic infections yielded partial 16S rRNA gene sequences that were taxonomically classified into 916 bacterial species-level operational taxonomic units (OTUs (at 3% divergence belonging to 67 genera and 13 phyla. The most abundant phyla in acute infections were Firmicutes (52%, Fusobacteria (17% and Bacteroidetes (13%, while in chronic infections the dominant were Firmicutes (59%, Bacteroidetes (14% and Actinobacteria (10%. Members of Fusobacteria were much more prevalent in acute (89% than in chronic cases (50%. The most abundant/prevalent genera in acute infections were Fusobacterium and Parvimonas. Twenty genera were exclusively detected in acute infections and 18 in chronic infections. Only 18% (n = 165 of the OTUs at 3% divergence were shared by acute and chronic infections. Diversity and richness estimators revealed that acute infections were significantly more diverse than chronic infections. Although a high interindividual variation in bacterial communities was observed, many samples tended to group together according to the type of infection (acute or chronic. This study is one of the most comprehensive in-deep comparisons of the microbiota associated with acute and chronic dental root canal infections and highlights the role of diverse polymicrobial communities as the unit of pathogenicity in acute infections. The overall diversity of endodontic infections as revealed by the pyrosequencing technique was much higher than previously reported for endodontic infections.

Middle Ear Infection (Chronic Otitis Media) and Hearing Loss

Science.gov (United States)

... ENT Doctor Near You Middle Ear Infection (Chronic Otitis Media) and Hearing Loss Middle Ear Infection (Chronic ... relations staff at newsroom@entnet.org . What is otitis media? Otitis media refers to inflammation of the ...

Role of antimicrobial peptides in controlling symbiotic bacterial populations.

Science.gov (United States)

Mergaert, P

2018-04-25

Covering: up to 2018 Antimicrobial peptides (AMPs) have been known for well over three decades as crucial mediators of the innate immune response in animals and plants, where they are involved in the killing of infecting microbes. However, AMPs have now also been found to be produced by eukaryotic hosts during symbiotic interactions with bacteria. These symbiotic AMPs target the symbionts and therefore have a more subtle biological role: not eliminating the microbial symbiont population but rather keeping it in check. The arsenal of AMPs and the symbionts' adaptations to resist them are in a careful balance, which contributes to the establishment of the host-microbe homeostasis. Although in many cases the biological roles of symbiotic AMPs remain elusive, for a number of symbiotic interactions, precise functions have been assigned or proposed to the AMPs, which are discussed here. The microbiota living on epithelia in animals, from the most primitive ones to the mammals, are challenged by a cocktail of AMPs that determine the specific composition of the bacterial community as well as its spatial organization. In the symbiosis of legume plants with nitrogen-fixing rhizobium bacteria, the host deploys an extremely large panel of AMPs - called nodule-specific cysteine-rich (NCR) peptides - that drive the bacteria into a terminally differentiated state and manipulate the symbiont physiology to maximize the benefit for the host. The NCR peptides are used as tools to enslave the bacterial symbionts, limiting their reproduction but keeping them metabolically active for nitrogen fixation. In the nutritional symbiotic interactions of insects and protists that have vertically transmitted bacterial symbionts with reduced genomes, symbiotic AMPs could facilitate the integration of the endosymbiont and host metabolism by favouring the flow of metabolites across the symbiont membrane through membrane permeabilization.

Symbiotic stars

Science.gov (United States)

Kafatos, M.; Michalitsianos, A. G.

1984-01-01

The physical characteristics of symbiotic star systems are discussed, based on a review of recent observational data. A model of a symbiotic star system is presented which illustrates how a cool red-giant star is embedded in a nebula whose atoms are ionized by the energetic radiation from its hot compact companion. UV outbursts from symbiotic systems are explained by two principal models: an accretion-disk-outburst model which describes how material expelled from the tenuous envelope of the red giant forms an inwardly-spiralling disk around the hot companion, and a thermonuclear-outburst model in which the companion is specifically a white dwarf which superheats the material expelled from the red giant to the point where thermonuclear reactions occur and radiation is emitted. It is suspected that the evolutionary course of binary systems is predetermined by the initial mass and angular momentum of the gas cloud within which binary stars are born. Since red giants and Mira variables are thought to be stars with a mass of one or two solar mass, it is believed that the original cloud from which a symbiotic system is formed can consist of no more than a few solar masses of gas.

Autoreactive T Cells and Chronic Fungal Infection Drive Esophageal Carcinogenesis

Science.gov (United States)

Zhu, Feng; Willette-Brown, Jami; Song, Na-Young; Lomada, Dakshayani; Song, Yongmei; Xue, Liyan; Gray, Zane; Zhao, Zitong; Davis, Sean R.; Sun, Zhonghe; Zhang, Peilin; Wu, Xiaolin; Zhan, Qimin; Richie, Ellen R.; Hu, Yinling

2018-01-01

SUMMARY Humans with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), a T cell–driven autoimmune disease caused by impaired central tolerance, are susceptible to developing chronic fungal infection and esophageal squamous cell carcinoma (ESCC). However, the relationship between autoreactive T cells and chronic fungal infection in ESCC development remains unclear. We find that kinase-dead Ikkα knockin mice develop phenotypes reminiscent of APECED, including impaired central tolerance, autoreactive T cells, chronic fungal infection, and ESCCs expressing specific human ESCC markers. Using this model, we investigated the potential link between ESCC and fungal infection. Autoreactive CD4 T cells permit fungal infection and incite tissue injury and inflammation. Antifungal treatment or depletion of autoreactive CD4 T cells rescues, whereas oral fungal administration promotes, ESCC development. Inhibition of inflammation or EGFR activity decreases fungal burden. Importantly, fungal infection is highly associated with ESCCs in non-autoimmune human patients. Therefore, autoreactive T cells and chronic fungal infection, fostered by inflammation and epithelial injury, promote ESCC development. PMID:28407484

Middle Ear Infection (Chronic Otitis Media) and Hearing Loss

Science.gov (United States)

... Marketplace Find an ENT Doctor Near You Middle Ear Infection (Chronic Otitis Media) and Hearing Loss Middle Ear Infection (Chronic Otitis ... relations staff at newsroom@entnet.org . What is otitis media? Otitis media refers to inflammation of the middle ...

Immune regulation in chronic hepatitis C virus infection

DEFF Research Database (Denmark)

Hartling, Hans Jakob; Ballegaard, Vibe Cecilie; Nielsen, Nick Schou

2016-01-01

The immunological result of infection with Hepatitis C virus (HCV) depends on the delicate balance between a vigorous immune response that may clear the infection, but with a risk of unspecific inflammation and, or a less inflammatory response that leads to chronic infection. In general, exhaustion...... and impairment of cytotoxic function of HCV-specific T cells and NK cells are found in patients with chronic HCV infection. In contrast, an increase in immune regulatory functions is found primarily in form of increased IL-10 production possibly due to increased level and function of anti-inflammatory Tregs...

[Infected knee prostheses. Part 2: chronic late infections].

Science.gov (United States)

Herrmann, P; Thoele, P; Heppert, V

2013-06-01

Treatment of late and chronic infections, which require the replacement of all the infected implant material. All infections lasting more than 4 weeks that have been proven to be bacterial and/or obvious signs of infection. Unsuitable for anesthesia, high acute infection with sepsis and risk for bacteremia with danger to life, large soft tissue damage where plastic surgery coverage is not possible. Arthrotomy, synovectomy, removal of all foreign bodies including all residue of polymethylmethacrylate (PMMA), jet lavage, spacer, drainage, wound closure or temporary closure using vacuum sealing. Bed rest with a leg brace and drainage until daily drainage volume is exchange of the spacer. In the literature, the success rate for both the one-stage or the two-stage procedure is about 80-95%. In our very nonhomogeneous collective the overall rate of success is about 81%.

Symbiotic bacteria contribute to increasing the population size of a freshwater crustacean, Daphnia magna.

Science.gov (United States)

Peerakietkhajorn, Saranya; Tsukada, Koji; Kato, Yasuhiko; Matsuura, Tomoaki; Watanabe, Hajime

2015-04-01

The filter-feeding crustacean Daphnia is a key organism in freshwater ecosystems. Here, we report the effect of symbiotic bacteria on ecologically important life history traits, such as population dynamics and longevity, in Daphnia magna. By disinfection of the daphniid embryos with glutaraldehyde, aposymbiotic daphniids were prepared and cultured under bacteria-free conditions. Removal of bacteria from the daphniids was monitored by quantitative polymerase chain reaction for bacterial 16S rRNA gene. The population of aposymbiotic daphniids was reduced 10-folds compared with that of the control daphniids. Importantly, re-infection with symbiotic bacteria caused daphniids to regain bacteria and increase their fecundity to the level of the control daphniids, suggesting that symbiotic bacteria regulate Daphnia fecundity. To identify the species of symbiotic bacteria, 16S rRNA genes of bacteria in daphniids were sequenced. This revealed that 50% of sequences belonged to the Limnohabitans sp. of the Betaproteobacteria class and that the diversity of bacterial taxa was relatively low. These results suggested that symbiotic bacteria have a beneficial effect on D. magna, and that aposymbiotic Daphnia are useful tools in understanding the role of symbiotic bacteria in the environmental responses and evolution of their hosts. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

Airway inflammation in nonobstructive and obstructive chronic bronchitis with chronic haemophilus influenzae airway infection. Comparison with noninfected patients with chronic obstructive pulmonary disease

NARCIS (Netherlands)

Bresser, P.; Out, T. A.; van Alphen, L.; Jansen, H. M.; Lutter, R.

2000-01-01

Nonencapsulated Haemophilus influenzae often causes chronic infections of the lower respiratory tract in both nonobstructive and obstructive chronic bronchitis. We assessed airway inflammation in clinically stable, chronically H. influenzae-infected patients with nonobstructive (CB-HI, n = 10) and

Chronic Gastritis and its Association with H. Pylori Infection.

Science.gov (United States)

Fatema, J; Khan, A H; Uddin, M J; Rahman, M H; Saha, M; Safwath, S A; Alam, M J; Mamun, M A

2015-10-01

This cross sectional study was designed to see association of chronic gastritis including its type with H. pylori infection. Consecutive patients undergoing endoscopic examination having histopathological evidence of chronic gastritis were enrolled in the study and was done in Sylhet MAG Osmani Medical College from July 2011 to June 2012. Biopsies were taken from antrum, body and fundus in all patients. Histopathological examinations were done using H-E stain and for detection of H. pylori, rapid urease test, anti-H.pylori antibody test and histopathological test with modified Giemsa stain were done. Patients having results positive in at least two methods were considered infected by H. pylori. Total 80 dyspeptic patients having chronic gastritis were evaluated. Out of them 67(83.8%) had H. pylori infection and 13(16.2%) were H. pylori negative. Among all patients 57(71.2%) had pangastritis and 23(28.8%) had antral gastritis with female and male predominance respectively. H. pylori infection was present in 49(86.0%) cases of pangastritis and 18(78.3%) cases of antral gastritis. H. pylori infection was a little higher among males (34, 50.7%) females (33, 49.3%). H. pylori infection is the predominant cause of chronic gastritis and pangastritis is the major type.

LysM domains mediate lipochitin-oligosaccharide recognition and Nfr genes extend the symbiotic host range

DEFF Research Database (Denmark)

Radutoiu, Simona; Madsen, Lene H; Madsen, Esben B

2007-01-01

and Nfr5 Nod-factor receptor genes in Medicago truncatula and L. filicaulis, extends their host range to include bacterial strains, Mesorhizobium loti or DZL, normally infecting L. japonicus. As a result, the symbiotic program is induced, nodules develop and infection threads are formed. Using L...

Symbiotic stars

International Nuclear Information System (INIS)

Kafatos, M.; Michalitsianos, A.G.

1984-01-01

Among the several hundred million binary systems estimated to lie within 3000 light years of the solar system, a tiny fraction, no more than a few hundred, belong to a curious subclass whose radiation has a wavelength distribution so peculiar that it long defied explanation. Such systems radiate strongly in the visible region of the spectrum, but some of them do so even more strongly at both shorter and longer wavelengths: in the ultraviolet region and in the infrared and radio regions. This odd distribution of radiation is best explained by the pairing of a cool red giant star and an intensely hot small star that is virtually in contact with its larger companion. Such objects have become known as symbiotic stars. On photographic plate only the giant star can be discerned, but evidence for the existence of the hot companion has been supplied by satellite-born instruments capable of detecting ultraviolet radiation. The spectra of symbiotic stars indicate that the cool red giant is surrounded by a very hot ionized gas. Symbiotic stars also flared up in outbursts indicating the ejection of material in the form of a shell or a ring. Symbiotic stars may therefore represent a transitory phase in the evolution of certain types of binary systems in which there is substantial transfer of matter from the larger partner to the smaller

The symbiotics as binary stars

International Nuclear Information System (INIS)

Plavec, M.J.

1982-01-01

The author envisages at least three models that can give a symbiotic object: He has called them, respectively, the PN symbiotic, the Algol symbiotic, and the novalike symbiotic. Their properties are briefly discussed. The most promising model is one of a binary system in the second stage of mass transfer, actually at the beginning of it: The cool component is a red giant ascending the asymptotic branch, expanding but not yet filling its critical lobe. The hot star is a subdwarf located in the same region of the Hertzsprung-Russell diagram as the central stars of planetary nebulae. It may be closely related to them, or it may be a helium star, actually a remnant of an Algol primary which underwent the first stage of mass transfer. In these cases, accretion on this star may not play a significant role (PN symbiotic). Perhaps more often, the subdwarf is a ''rejuvenated'' degenerate dwarf whose nuclear burning shells were ignited and are maintained by accretion of material coming from the red giant in the form of a stellar wind. Eruptions are often inevitable: this is the novalike symbiotic. A third alternative is a system in the first stage of mass transfer, where the photons needed for ionization of the nebula come from an accretion disk surrounding a main sequence star: an Algol symbiotic. In spite of considerable observational effort, the symbiotics are known so poorly that it is hard to decide between the models, or even decide if all three can actually exist. (Auth.)

Extrahepatic manifestations associated with Chronic Hepatitis C Virus Infection

Directory of Open Access Journals (Sweden)

A. Flores-Chávez

Full Text Available Summary Chronic hepatitis C virus (HCV infection has been associated with both organ-specific and systemic autoimmune diseases, with cryoglobulinemia being the most frequent associated disease. Experimental, virologic, and clinical evidence have demon-strated a close association between HCV infection and some systemic autoimmune diseases, especially Sjögren’s syndrome, but also rheumatoid arthritis and lupus. A higher prevalence of hematological processes has also been described in patients with HCV infection, including cytopenias and lymphoproliferative disorders (B-cell lymphoma. In addition, patients with chronic HCV infection have a higher frequency of other extrahepatic manifestations including endocrine, metabolic and cardiovascular disorders that may worse the prognosis of patients, along with neuropsychiatric manifestations and general symptoms that have a significant influence on the quality of life of the patient. Direct-acting antiviral therapies (DAAs that have recently begun to be used are providing the opportunity to effectively cure chronic HCV infection and reduce the burden of both hepatic and extrahepatic complications.

Chronic hepatitis caused by persistent parvovirus B19 infection

Directory of Open Access Journals (Sweden)

Mogensen Trine H

2010-08-01

Full Text Available Abstract Background Human infection with parvovirus B19 may lead to a diverse spectrum of clinical manifestations, including benign erythema infectiosum in children, transient aplastic crisis in patients with haemolytic anaemia, and congenital hydrops foetalis. These different diseases represent direct consequences of the ability of parvovirus B19 to target the erythroid cell lineage. However, accumulating evidence suggests that this virus can also infect other cell types resulting in diverse clinical manifestations, of which the pathogenesis remains to be fully elucidated. This has prompted important questions regarding the tropism of the virus and its possible involvement in a broad range of infectious and autoimmune medical conditions. Case Presentation Here, we present an unusual case of persistent parvovirus B19 infection as a cause of chronic hepatitis. This patient had persistent parvovirus B19 viraemia over a period of more than four years and displayed signs of chronic hepatitis evidenced by fluctuating elevated levels of ALAT and a liver biopsy demonstrating chronic hepatitis. Other known causes of hepatitis and liver damage were excluded. In addition, the patient was evaluated for immunodeficiency, since she had lymphopenia both prior to and following clearance of parvovirus B19 infection. Conclusions In this case report, we describe the current knowledge on the natural history and pathogenesis of parvovirus B19 infection, and discuss the existing evidence of parvovirus B19 as a cause of acute and chronic hepatitis. We suggest that parvovirus B19 was the direct cause of this patient's chronic hepatitis, and that she had an idiopathic lymphopenia, which may have predisposed her to persistent infection, rather than bone marrow depression secondary to infection. In addition, we propose that her liver involvement may have represented a viral reservoir. Finally, we suggest that clinicians should be aware of parvovirus B19 as an unusual

Cost of Illness of Chronic Hepatitis B Infection in Vietnam

NARCIS (Netherlands)

Tu, Hong Anh T.; Woerdenbag, Herman J.; Riewpaiboon, Arthorn; Kane, Sumit; Le, Diep M.; Postma, Maarten J.; Li, Shu Chuen

2012-01-01

To estimate the total financial burden of chronic hepatitis B virus (HBV) infection for Vietnam by quantifying the direct medical, the direct nonmedical, and indirect costs among patients with various stages of chronic HBV infection. Direct medical cost data were retrieved retrospectively from

Epidemic Spread of Symbiotic and Non-Symbiotic Bradyrhizobium Genotypes Across California.

Science.gov (United States)

Hollowell, A C; Regus, J U; Gano, K A; Bantay, R; Centeno, D; Pham, J; Lyu, J Y; Moore, D; Bernardo, A; Lopez, G; Patil, A; Patel, S; Lii, Y; Sachs, J L

2016-04-01

The patterns and drivers of bacterial strain dominance remain poorly understood in natural populations. Here, we cultured 1292 Bradyrhizobium isolates from symbiotic root nodules and the soil root interface of the host plant Acmispon strigosus across a >840-km transect in California. To investigate epidemiology and the potential role of accessory loci as epidemic drivers, isolates were genotyped at two chromosomal loci and were assayed for presence or absence of accessory "symbiosis island" loci that encode capacity to form nodules on hosts. We found that Bradyrhizobium populations were very diverse but dominated by few haplotypes-with a single "epidemic" haplotype constituting nearly 30 % of collected isolates and spreading nearly statewide. In many Bradyrhizobium lineages, we inferred presence and absence of the symbiosis island suggesting recurrent evolutionary gain and or loss of symbiotic capacity. We did not find statistical phylogenetic evidence that the symbiosis island acquisition promotes strain dominance and both symbiotic and non-symbiotic strains exhibited population dominance and spatial spread. Our dataset reveals that a strikingly few Bradyrhizobium genotypes can rapidly spread to dominate a landscape and suggests that these epidemics are not driven by the acquisition of accessory loci as occurs in key human pathogens.

Phenotypic complementation of genetic immunodeficiency by chronic herpesvirus infection.

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MacDuff, Donna A; Reese, Tiffany A; Kimmey, Jacqueline M; Weiss, Leslie A; Song, Christina; Zhang, Xin; Kambal, Amal; Duan, Erning; Carrero, Javier A; Boisson, Bertrand; Laplantine, Emmanuel; Israel, Alain; Picard, Capucine; Colonna, Marco; Edelson, Brian T; Sibley, L David; Stallings, Christina L; Casanova, Jean-Laurent; Iwai, Kazuhiro; Virgin, Herbert W

2015-01-20

Variation in the presentation of hereditary immunodeficiencies may be explained by genetic or environmental factors. Patients with mutations in HOIL1 (RBCK1) present with amylopectinosis-associated myopathy with or without hyper-inflammation and immunodeficiency. We report that barrier-raised HOIL-1-deficient mice exhibit amylopectin-like deposits in the myocardium but show minimal signs of hyper-inflammation. However, they show immunodeficiency upon acute infection with Listeria monocytogenes, Toxoplasma gondii or Citrobacter rodentium. Increased susceptibility to Listeria was due to HOIL-1 function in hematopoietic cells and macrophages in production of protective cytokines. In contrast, HOIL-1-deficient mice showed enhanced control of chronic Mycobacterium tuberculosis or murine γ-herpesvirus 68 (MHV68), and these infections conferred a hyper-inflammatory phenotype. Surprisingly, chronic infection with MHV68 complemented the immunodeficiency of HOIL-1, IL-6, Caspase-1 and Caspase-1;Caspase-11-deficient mice following Listeria infection. Thus chronic herpesvirus infection generates signs of auto-inflammation and complements genetic immunodeficiency in mutant mice, highlighting the importance of accounting for the virome in genotype-phenotype studies.

Symbiotic formulation in experimentally induced liver fibrosis in rats: intestinal microbiota as a key point to treat liver damage?

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D'Argenio, Giuseppe; Cariello, Rita; Tuccillo, Concetta; Mazzone, Giovanna; Federico, Alessandro; Funaro, Annalisa; De Magistris, Laura; Grossi, Enzo; Callegari, Maria L; Chirico, Marilena; Caporaso, Nicola; Romano, Marco; Morelli, Lorenzo; Loguercio, Carmela

2013-05-01

Evidence indicates that intestinal microbiota may participate in both the induction and the progression of liver damage. The aim of our research was the detection and evaluation of the effects of chronic treatment with a symbiotic formulation on CCl4 -induced rat liver fibrosis. CCl4 significantly increased gastric permeability in respect to basal values, and the treatment with symbiotic significantly decreased it. CCl4 per se induced a decrease in intestinal permeability. This effect was also seen in fibrotic rats treated with symbiotic and was still evident when normal rats were treated with symbiotic alone (P symbiotic treatment normalized the plasma levels of TNF-α and significantly enhanced anti-inflammatory cytokine IL 10. TNF-α, TGF-β, TLR4, TLR2, iNOS and α-SMA mRNA expression in the liver were up-regulated in rats with CCl4 -induced liver fibrosis and down-regulated by symbiotic treatment. Moreover, IL-10 and eNOS mRNA levels were increased in the CCL4 (+) symbiotic group. Symbiotic treatment of fibrotic rats normalized serum ALT, AST and improved histology and liver collagen deposition. DGGE analysis of faecal samples revealed that CCl4 administration and symbiotic treatment either alone or in combination produced modifications in faecal profiles vs controls. Our results provide evidence that in CCl4 -induced liver fibrosis, significant changes in gastro-intestinal permeability and in faecal flora occur. Treatment with a specific symbiotic formulation significantly affects these changes, leading to improvement in both liver inflammation and fibrosis. © 2013 John Wiley & Sons A/S.

Symbiotic Optimization of Behavior

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2015-05-01

SYMBIOTIC OPTIMIZATION OF BEHAVIOR UNIVERSITY OF WASHINGTON MAY 2015 FINAL TECHNICAL REPORT APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED...2014 4. TITLE AND SUBTITLE SYMBIOTIC OPTIMIZATION OF BEHAVIOR 5a. CONTRACT NUMBER FA8750-12-1-0304 5b. GRANT NUMBER N/A 5c. PROGRAM ELEMENT

Chronic hepatitis B virus infection in Asian countries.

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Merican, I; Guan, R; Amarapuka, D; Alexander, M J; Chutaputti, A; Chien, R N; Hasnian, S S; Leung, N; Lesmana, L; Phiet, P H; Sjalfoellah Noer, H M; Sollano, J; Sun, H S; Xu, D Z

2000-12-01

Of the estimated 50 million new cases of hepatitis B virus (HBV) infection diagnosed annually, 5-10% of adults and up to 90% of infants will become chronically infected, 75% of these in Asia where hepatitis B is the leading cause of chronic hepatitis, cirrhosis and hepatocellular carcinoma (HCC). In Indonesia, 4.6% of the population was positive for HBsAg in 1994 and of these, 21% were positive for HBeAg and 73% for anti-HBe; 44% and 45% of Indonesian patients with cirrhosis and HCC, respectively, were HBsAg positive. In the Philippines, there appear to be two types of age-specific HBsAg prevalence, suggesting different modes of transmission. In Thailand, 8-10% of males and 6-8% of females are HBsAg positive, with HBsAg also found in 30% of patients with cirrhosis and 50-75% of those with HCC. In Taiwan, 75-80% of patients with chronic liver disease are HBsAg positive, and HBsAg is found in 34% and 72% of patients with cirrhosis and HCC, respectively. In China, 73% of patients with chronic hepatitis and 78% and 71% of those with cirrhosis and HCC, respectively, are HBsAg positive. In Singapore, the prevalence of HBsAg has dropped since the introduction of HBV vaccination and the HBsAg seroprevalence of unvaccinated individuals over 5 years of age is 4.5%. In Malaysia, 5.24% of healthy volunteers, with a mean age of 34 years, were positive for HBsAg in 1997. In the highly endemic countries in Asia, the majority of infections are contracted postnatally or perinatally. Three phases of chronic HBV infection are recognized: phase 1 patients are HBeAg positive with high levels of virus in the serum and minimal hepatic inflammation; phase 2 patients have intermittent or continuous hepatitis of varying degrees of severity; phase 3 is the inactive phase during which viral concentrations are low and there is minimal inflammatory activity in the liver. In general, patients who clear HBeAg have a better prognosis than patients who remain HBeAg-positive for prolonged periods of

Phage inhibit pathogen dissemination by targeting bacterial migrants in a chronic infection model

DEFF Research Database (Denmark)

Darch, Sophie E.; Kragh, Kasper N.; Abbott, Evelyn A.

2017-01-01

The microbial communities inhabiting chronic infections are often composed of spatially organized micrometer-sized, highly dense aggregates. It has recently been hypothesized that aggregates are responsible for the high tolerance of chronic infections to host immune functions and antimicrobial...... production; however, seeding of new aggregates by dispersed migrants was inhibited. We propose a model in which aggregates provide a mechanism that allows P. aeruginosa to tolerate phage therapy during chronic infection without the need for genetic mutation. IMPORTANCE Bacteria in chronic infections often...... reside in communities composed of micrometer-sized, highly dense aggregates. A primary challenge for studying aggregates has been the lack of laboratory systems that promote natural aggregate formation in relevant environments. Here, we developed a growth medium that mimics chronic lung infection...

Microbiome change by symbiotic invasion in lichens

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Maier, Stefanie; Wedin, Mats; Fernandez-Brime, Samantha; Cronholm, Bodil; Westberg, Martin; Weber, Bettina; Grube, Martin

2016-04-01

Biological soil crusts (BSC) seal the soil surface from erosive forces in many habitats where plants cannot compete. Lichens symbioses of fungi and algae often form significant fraction of these microbial assemblages. In addition to the fungal symbiont, many species of other fungi can inhabit the lichenic structures and interact with their hosts in different ways, ranging from commensalism to parasitism. More than 1800 species of lichenicolous (lichen-inhabiting) fungi are known to science. One example is Diploschistes muscorum, a common species in lichen-dominated BSC that infects lichens of the genus Cladonia. D. muscorum starts as a lichenicolous fungus, invading the lichen Cladonia symphycarpa and gradually develops an independent Diploschistes lichen thallus. Furthermore, bacterial groups, such as Alphaproteobacteria and Acidobacteria, have been consistently recovered from lichen thalli and evidence is rapidly accumulating that these microbes may generally play integral roles in the lichen symbiosis. Here we describe lichen microbiome dynamics as the parasitic lichen D. muscorum takes over C. symphycarpa. We used high-throughput 16S rRNA gene and photobiont-specific ITS rDNA sequencing to track bacterial and algal transitions during the infection process, and employed fluorescence in situ hybridization to localize bacteria in the Cladonia and Diploschistes lichen thalli. We sampled four transitional stages, at sites in Sweden and Germany: A) Cladonia with no visible infection, B) early infection stage defined by the first visible Diploschistes thallus, C) late-stage infection with parts of the Cladonia thallus still identifiable, and D) final stage with a fully developed Diploschistes thallus, A gradual microbiome shift occurred during the transition, but fractions of Cladonia-associated bacteria were retained during the process of symbiotic reorganization. Consistent changes observed across sites included a notable decrease in the relative abundance of

Interplay of Pathogen-Induced Defense Responses and Symbiotic Establishment in Medicago truncatula

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Tao Chen

2017-05-01

Full Text Available Suppression of host innate immunity appears to be required for the establishment of symbiosis between rhizobia and host plants. In this study, we established a system that included a host plant, a bacterial pathogen and a symbiotic rhizobium to study the role of innate immunity during symbiotic interactions. A pathogenic bacterium, Pseudomonas syringae pv. tomato strain DC3000 (Pst DC3000, was shown to cause chlorosis in Medicago truncatula A17. Sinorhizobium meliloti strain Sm2011 (Sm2011 and Pst DC3000 strain alone induced similar defense responses in M. truncatula. However, when co-inoculated, Sm2011 specifically suppressed the defense responses induced by Pst DC3000, such as MAPK activation and ROS production. Inoculation with Sm2011 suppressed the transcription of defense-related genes triggered by Pst DC3000 infection, including the receptor of bacterial flagellin (FLS2, pathogenesis-related protein 10 (PR10, and the transcription factor WRKY33. Interestingly, inoculation with Pst DC3000 specifically inhibited the expression of the symbiosis marker genes nodule inception and nodulation pectate lyase and reduced the numbers of infection threads and nodules on M. truncatula A17 roots, indicating that Pst DC3000 inhibits the establishment of symbiosis in M. truncatula. In addition, defense-related genes, such as MAPK3/6, RbohC, and WRKY33, exhibited a transient increase in their expression in the early stage of symbiosis with Sm2011, but the expression dropped down to normal levels at later symbiotic stages. Our results suggest that plant innate immunity plays an antagonistic role in symbiosis by directly reducing the numbers of infection threads and nodules.

Do symbiotic and Vitamin E supplementation have favorite effects in nonalcoholic fatty liver disease? A randomized, double-blind, placebo-controlled trial.

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Ekhlasi, Golnaz; Kolahdouz Mohammadi, Roya; Agah, Shahram; Zarrati, Mitra; Hosseini, Agha Fatemeh; Arabshahi, Seyed Soroush Soltani; Shidfar, Farzad

2016-01-01

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the world. Oral administration of symbiotic and Vitamin E has been proposed as an effective treatment in NAFLD patients. This study was carried out to assess the effects of symbiotic and/or Vitamin E supplementation on liver enzymes, leptin, lipid profile, and some parameters of insulin resistance (IR) in NAFLD patients. We randomly assigned sixty NAFLD adult patients to receive (1) symbiotic twice daily + Vitamin E-like placebo capsule; (2) 400 IU/d Vitamin E + symbiotic-like placebo; (3) symbiotic twice daily + 400 IU/d Vitamin E; and (4) symbiotic-like placebo + Vitamin E-like placebo for 8 weeks. Symbiotic plus Vitamin E supplementation led to a significant decrease in concentrations of liver transaminase ( P ≤ 0.05). Mean difference of apolipoprotein A-1 was more significant in symbiotic group compared to control. However, mean difference of apolipoprotein B100/A-1 was only significant in symbiotic group compared to control. At the end of the study, significant differences in total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) were seen between the symbiotic plus Vitamin E and control groups ( P symbiotic plus Vitamin E supplements led to a significant decrease in concentrations of triglycerides (TG) after the intervention. Significant differences in leptin, fasting blood sugar (FBS), and insulin levels were seen between the symbiotic plus Vitamin E and control groups at the end of the study ( P symbiotic and/or Vitamin E supplementation did not affect high-density lipoprotein cholesterol and homeostasis model assessment for IR levels. In our study, symbiotic plus Vitamin E supplementation was the most effective treatment in lowering liver enzymes, leptin, FBS, insulin, TG, TC, and LDL-C among NAFLD patients.

High infection control rate and function after routine one-stage exchange for chronically infected TKA.

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Jenny, Jean-Yves; Barbe, Bruno; Gaudias, Jeannot; Boeri, Cyril; Argenson, Jean-Noël

2013-01-01

Many surgeons consider two-stage exchange the gold standard for treating chronic infection after TKA. One-stage exchange is an alternative for infection control and might provide better knee function, but the rates of infection control and levels of function are unclear. We asked whether a one-stage exchange protocol would lead to infection control rates and knee function similar to those after two-stage exchange. We followed all 47 patients with chronically infected TKAs treated with one-stage exchange between July 2004 and February 2007. We monitored for recurrence of infection and obtained Knee Society Scores. We followed patients a minimum of 3 years or until death or infection recurrence. Three of the 47 patients (6%) experienced a persistence or recurrence of the index infection with the same pathogen isolated. Three patients (6%) had control of the index infection but between 6 and 17 months experienced an infection with another pathogen. The 3-year survival rates were 87% for being free of any infection and 91% for being healed of the index infection. Twenty-five of the 45 patients (56%) had a Knee Society Score of more than 150 points. While routine one-stage exchange was not associated with a higher rate of infection recurrence failure, knee function was not improved compared to that of historical patients having two-stage exchange. One stage-exchange may be a reasonable alternative in chronically infected TKA as a more convenient approach for patients without the risks of two operations and hospitalizations and for reducing costs. The ideal one stage-exchange candidate should be identified in future studies.

Bystander chronic infection negatively impacts development of CD8+ T cell memory

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Stelekati, Erietta; Shin, Haina; Doering, Travis A.; Dolfi, Douglas V.; Ziegler, Carly G.; Beiting, Daniel P.; Dawson, Lucas; Liboon, Jennifer; Wolski, David; Ali, Mohammed-Alkhatim A.; Katsikis, Peter D.; Shen, Hao; Roos, David S.; Haining, W. Nicholas; Lauer, Georg M.; Wherry, E. John

2014-01-01

Summary Epidemiological evidence suggests that chronic infections impair immune responses to unrelated pathogens and vaccines. The underlying mechanisms, however, are unclear and distinguishing effects on priming versus development of immunological memory has been challenging. We investigated whether bystander chronic infections impact differentiation of memory CD8+ T cells, the hallmark of protective immunity against intracellular pathogens. Chronic bystander infections impaired development of memory CD8+ T cells in several mouse models and humans. These effects were independent of initial priming and were associated with chronic inflammatory signatures. Chronic inflammation negatively impacted the number of bystander CD8+ T cells and their memory development. Distinct underlying mechanisms of altered survival and differentiation were revealed with the latter regulated by the transcription factors T-bet and Blimp-1. Thus, exposure to prolonged bystander inflammation impairs the effector to memory transition. These data have relevance for immunity and vaccination during persisting infections and chronic inflammation. PMID:24837104

[Comorbidities as risk factors of chronic kidney disease in HIV-infected persons].

Science.gov (United States)

Marchewka, Zofia; Szymczak, Aleksandra; Knysz, Brygida

2015-12-16

Significant survival prolongation in HIV-infected patients due to effective antiretroviral therapy is connected with increasing prevalence of chronic non-infective diseases in this population, among them chronic kidney disease. The pathogenesis of kidney disease in the setting of HIV includes conditions specific for HIV infection: direct effect of the virus, stage of immunodeficiency and drug toxicity. Chronic comorbidities, such as diabetes mellitus, hypertension, and hyperlipidemia, are additional significant risk factors of kidney disease. In HIV-infected individuals some distinct features of these conditions are observed, which are partly related to the virus and antiretroviral therapy. The article summarizes the effect of comorbidities on kidney function in HIV-infected persons.

A lung segmental model of chronic Pseudomonas infection in sheep.

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David Collie

Full Text Available Chronic lung infection with Pseudomonas aeruginosa is a major contributor to morbidity, mortality and premature death in cystic fibrosis. A new paradigm for managing such infections is needed, as are relevant and translatable animal models to identify and test concepts. We sought to improve on limitations associated with existing models of infection in small animals through developing a lung segmental model of chronic Pseudomonas infection in sheep.Using local lung instillation of P. aeruginosa suspended in agar beads we were able to demonstrate that such infection led to the development of a suppurative, necrotising and pyogranulomatous pneumonia centred on the instilled beads. No overt evidence of organ or systemic compromise was apparent in any animal during the course of infection. Infection persisted in the lungs of individual animals for as long as 66 days after initial instillation. Quantitative microbiology applied to bronchoalveolar lavage fluid derived from infected segments proved an insensitive index of the presence of significant infection in lung tissue (>10(4 cfu/g.The agar bead model of chronic P. aeruginosa lung infection in sheep is a relevant platform to investigate both the pathobiology of such infections as well as novel approaches to their diagnosis and therapy. Particular ethical benefits relate to the model in terms of refining existing approaches by compromising a smaller proportion of the lung with infection and facilitating longitudinal assessment by bronchoscopy, and also potentially reducing animal numbers through facilitating within-animal comparisons of differential therapeutic approaches.

A lung segmental model of chronic Pseudomonas infection in sheep.

Science.gov (United States)

Collie, David; Govan, John; Wright, Steven; Thornton, Elisabeth; Tennant, Peter; Smith, Sionagh; Doherty, Catherine; McLachlan, Gerry

2013-01-01

Chronic lung infection with Pseudomonas aeruginosa is a major contributor to morbidity, mortality and premature death in cystic fibrosis. A new paradigm for managing such infections is needed, as are relevant and translatable animal models to identify and test concepts. We sought to improve on limitations associated with existing models of infection in small animals through developing a lung segmental model of chronic Pseudomonas infection in sheep. Using local lung instillation of P. aeruginosa suspended in agar beads we were able to demonstrate that such infection led to the development of a suppurative, necrotising and pyogranulomatous pneumonia centred on the instilled beads. No overt evidence of organ or systemic compromise was apparent in any animal during the course of infection. Infection persisted in the lungs of individual animals for as long as 66 days after initial instillation. Quantitative microbiology applied to bronchoalveolar lavage fluid derived from infected segments proved an insensitive index of the presence of significant infection in lung tissue (>10(4) cfu/g). The agar bead model of chronic P. aeruginosa lung infection in sheep is a relevant platform to investigate both the pathobiology of such infections as well as novel approaches to their diagnosis and therapy. Particular ethical benefits relate to the model in terms of refining existing approaches by compromising a smaller proportion of the lung with infection and facilitating longitudinal assessment by bronchoscopy, and also potentially reducing animal numbers through facilitating within-animal comparisons of differential therapeutic approaches.

Outbursts in Symbiotic Binaries

Science.gov (United States)

Sonneborn, George (Technical Monitor); Kenyon, Scott J.

2004-01-01

Two models have been proposed for the outbursts of symbiotic stars. In the thermonuclear model, outbursts begin when the hydrogen burning shell of a hot white dwarf reaches a critical mass. After a rapid increase in the luminosity and effective temperature, the white dwarf evolves at constant luminosity to lower effective temperatures, remains at optical maximum for several years, and then returns to quiescence along a white dwarf cooling curve. In disk instability models, the brightness rises when the accretion rate from the disk onto the central white dwarf abruptly increases by factors of 5-20. After a few month to several year period at maximum, both the luminosity and the effective temperature of the disk decline as the system returns to quiescence. If most symbiotic stars undergo thermonuclear eruptions, then symbiotics are probably poor candidates for type I supernovae. However, they can then provide approx. 10% of the material which stars recycle back into the interstellar medium. If disk instabilities are the dominant eruption mechanism, symbiotics are promising type Ia candidates but recycle less material into the interstellar medium.

Chronic prostatic infection and inflammation by Propionibacterium acnes in a rat prostate infection model.

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Olsson, Jan; Drott, Johanna Bergh; Laurantzon, Lovisa; Laurantzon, Oscar; Bergh, Anders; Elgh, Fredrik

2012-01-01

Chronic inflammation in the prostate, seen as infiltration of inflammatory cells into the prostate gland in histological samples, affects approximately half the male population without indication of prostate disease, and is almost ubiquitous in patients diagnosed with benign prostate hyperplasia and cancer. Several studies have demonstrated the gram-positive bacterium Propionibacterium acnes to be frequently present in prostate tissue from men suffering from prostate disease. P. acnes has been shown to be associated with histological inflammation in human prostatectomy specimens, and also to induce strong inflammatory response in prostate-derived tissue culture models. The present paper describes a rat model for assessment of the pathogenic potential of P. acnes in prostate. Prostate glands of Sprague Dawley rats (n = 98) were exposed via an abdominal incision and live P. acnes or, in control rats, saline were injected into the ventral and dorso-lateral lobes. Rats were sacrificed 5 days, 3 weeks, 3 months and 6 months post infection, and prostate tissue was analyzed for bacterial content and histological inflammation. Rat sera were assessed for levels of CRP and anti-P. acnes IgG. Live P. acnes could be recovered from the dorso-lateral lobes up to 3 months post infection, while the ventral lobes were cleared from bacteria at that time. In samples up to 3 months post infection, the dorso-lateral lobes exhibited intense focal inflammation. CRP and IgG levels were elevated throughout the span of the experiment, and reached maximum levels 3 weeks and 3 months post infection, respectively. We show that P. acnes have the potential to cause chronic infection in previously healthy prostate, and that the infection has potential to cause chronic histological inflammation in the infected tissue. The high prevalence of P. acnes in human prostate tissue calls for resolution of pathogenic details. The present rat model suggests that complications such as chronic

Symbiotic Stars in X-rays

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Luna, G. J. M.; Sokoloski, J. L.; Mukai, K.; Nelson, T.

2014-01-01

Until recently, symbiotic binary systems in which a white dwarf accretes from a red giant were thought to be mainly a soft X-ray population. Here we describe the detection with the X-ray Telescope (XRT) on the Swift satellite of 9 white dwarf symbiotics that were not previously known to be X-ray sources and one that was previously detected as a supersoft X-ray source. The 9 new X-ray detections were the result of a survey of 41 symbiotic stars, and they increase the number of symbiotic stars known to be X-ray sources by approximately 30%. Swift/XRT detected all of the new X-ray sources at energies greater than 2 keV. Their X-ray spectra are consistent with thermal emission and fall naturally into three distinct groups. The first group contains those sources with a single, highly absorbed hard component, which we identify as probably coming from an accretion-disk boundary layer. The second group is composed of those sources with a single, soft X-ray spectral component, which likely arises in a region where low-velocity shocks produce X-ray emission, i.e. a colliding-wind region. The third group consists of those sources with both hard and soft X-ray spectral components. We also find that unlike in the optical, where rapid, stochastic brightness variations from the accretion disk typically are not seen, detectable UV flickering is a common property of symbiotic stars. Supporting our physical interpretation of the two X-ray spectral components, simultaneous Swift UV photometry shows that symbiotic stars with harder X-ray emission tend to have stronger UV flickering, which is usually associated with accretion through a disk. To place these new observations in the context of previous work on X-ray emission from symbiotic stars, we modified and extended the alpha/beta/gamma classification scheme for symbiotic-star X-ray spectra that was introduced by Muerset et al. based upon observations with the ROSAT satellite, to include a new sigma classification for sources with

The role of helicobacter pylori infection in the pathogenesis of chronic urticaria

International Nuclear Information System (INIS)

Ghazzawi, I.M.; Obidat, N.A.

2004-01-01

Objective: To determine the prevalence of H. pylori infection in patients with idiopathic chronic urticaria (ICU) and to see if eradication of the bacterium affects the course of the urticaria. Patients and Methods: One hundred patients with idiopathic chronic urticaria and 43 healthy subjects (matched for age and sex) underwent serological testing for H. pylori infection. All patients with idiopathic chronic urticaria were examined for Helicobacter pylori infection with the /sup 13/C-urea test as well as the serological testing. Gastric biopsy was obtained from 36 patients. Patients with proven Helicobacter pylori infection were given treatment for 2 weeks. Six weeks afterwards they were tested again for Helicobacter pylori infection, and their urticaria was clinically assessed. Results: There was no significant difference in the seroprevalence of H. pylori infection between : idiopathic chronic urticaria patients and healthy subjects. Helicobacter pylori was detected in 76% of patients and 69.8% of controls. Out of the 76 patients treated, only 24 showed complete remission of their urticaria after successfully eradicating Helicobacter pylori infection, the others only having some improvement in their symptoms. Conclusion: Patients with idiopathic chronic urticaria have similar high rates of H. pylori infection as healthy subjects. Bacterium eradication is associated with improvement of urticaria symptoms, suggesting a possible role of Helicobacter pylori in the pathogenesis of this skin disorder. (author)

Symbiotic stars according to IRAS observations

International Nuclear Information System (INIS)

Luud, L.; Tuvikene, T.

1987-01-01

Symbiotic stars contained in Allen's catalog are examined with a view to establishing their coincidence with sources of far infrared radiation in the catalog of point sources observed with the IRAS satellite. Altogether, 72 symbiotic or suspected symbiotic objects have been identified. A list of the identified stars has been compiled, and the energy distributions in the infrared spectra of selected stars are given. It has been found that the presence of dust in symbiotic systems is a more widespread phenomenon than hitherto believed. Almost 40% of them are dust systems. Among them, objects with dust temperature of several tens of degrees kelvin have been found. It is shown that the only useful two-color diagram is the (K - m 12 )-(m 12 - m 25 ) diagram. Finally, attention is drawn to a type of symbiotic stars having cold components of the spectral class G; these require a special investigation

A polarimetric survey of symbiotic stars

International Nuclear Information System (INIS)

Schulte-Ladbeck, R.E.; Magalhaes, A.M.; Magalhaes, A.M.

1990-01-01

We present optical and near-infrared linear polarization observations of 24 symbiotic stars, 14 observed with polarimetry for the first time. In combination with published data, we find that ∼ 50% of the symbiotics observed polarimetrically show evidence for intrinsic polarization. We discuss the results in the light of previous observations and comment on the temporal variability and wavelength dependence of the polarization. Dust scattering is identified as the dominant mechanism producing polarization in symbiotic stars. While we cannot exclude that some symbiotic systems are completely engulfed in their dust shells our data indicate that the Hα emission line may originate from outside of the dust-scattering envelopes in some systems

Comorbidities as risk factors of chronic kidney disease in HIV-infected persons

Directory of Open Access Journals (Sweden)

Zofia Marchewka

2015-12-01

Full Text Available Significant survival prolongation in HIV-infected patients due to effective antiretroviral therapy is connected with increasing prevalence of chronic non-infective diseases in this population, among them chronic kidney disease. The pathogenesis of kidney disease in the setting of HIV includes conditions specific for HIV infection: direct effect of the virus, stage of immunodeficiency and drug toxicity. Chronic comorbidities, such as diabetes mellitus, hypertension, and hyperlipidemia, are additional significant risk factors of kidney disease. In HIV-infected individuals some distinct features of these conditions are observed, which are partly related to the virus and antiretroviral therapy. The article summarizes the effect of comorbidities on kidney function in HIV-infected persons.

 Molecular evolution and positive selection of the symbiotic gene NORK in Medicago truncatula

DEFF Research Database (Denmark)

De Mita, Stephane; Santoni, Sylvain; Hochu, Isabelle

2006-01-01

. The membrane-anchored receptor NORK (nodulation receptor kinase) of the legume Medicago truncatula controls early steps of root infection by two symbiotic microorganisms: nitrogen-fixing bacteria (rhizobia) and endomycorrhizal fungi (Glomales). We analyzed the diversity of the gene NORK by sequencing 4...

Properties of cold components of symbiotic stars

International Nuclear Information System (INIS)

Luud, L.; Leehdyarv, L.

1986-01-01

Using the Blackwell-Shallis method the luminosities, temperatures and radii for cold components of symbiotic stars and for a sample of field red giants have been determined by means of infrared photometric observations. It turned out that the cold components of symbiotic stars do not differ from the normal red giants of the asymptotic branch. The masses of cold components of symbiotic stars have been found to be close to 3 M* (M* is the solar mass).The cold components of symbiotic stars do not fill their Roche lobes. About 10 times more carbon stars than the normal value in the vicinity of the Sun have been found among the cold components of symbiotic stars

Identification of entomopathogenic nematodes and symbiotic bacteria from Nam Nao National Park in Thailand and larvicidal activity of symbiotic bacteria against Aedes aegypti and Aedes albopictus.

Science.gov (United States)

Yooyangket, Temsiri; Muangpat, Paramaporn; Polseela, Raxsina; Tandhavanant, Sarunporn; Thanwisai, Aunchalee; Vitta, Apichat

2018-01-01

Entomopathogenic nematodes (EPNs) that are symbiotically associated with Xenorhabdus and Photorhabdus bacteria can kill target insects via direct infection and toxin action. There are limited reports identifying such organisms in the National Park of Thailand. Therefore, the objectives of this study were to identify EPNs and symbiotic bacteria from Nam Nao National Park, Phetchabun Province, Thailand and to evaluate the larvicidal activity of bacteria against Aedes aegypti and Ae. albopictus. A total of 12 EPN isolates belonging to Steinernema and Heterorhabditis were obtained form 940 soil samples between February 2014 and July 2016. EPNs were molecularly identified as S. websteri (10 isolates) and H. baujardi (2 isolates). Symbiotic bacteria were isolated from EPNs and molecularly identified as P. luminescens subsp. akhurstii (13 isolates), X. stockiae (11 isolates), X. vietnamensis (2 isolates) and X. japonica (1 isolate). For the bioassay, bacterial suspensions were evaluated for toxicity against third to early fourth instar larvae of Aedes spp. The larvae of both Aedes species were orally susceptible to symbiotic bacteria. The highest larval mortality of Ae. aegypti was 99% after exposure to X. stockiae (bNN112.3_TH) at 96 h, and the highest mortality of Ae. albopictus was 98% after exposure to P. luminescens subsp. akhurstii (bNN121.4_TH) at 96 h. In contrast to the control groups (Escherichia coli and distilled water), the mortality rate of both mosquito larvae ranged between 0 and 7% at 72 h. Here, we report the first observation of X. vietnamensis in Thailand. Additionally, we report the first observation of P. luminescens subsp. akhurstii associated with H. baujardi in Thailand. X. stockiae has potential to be a biocontrol agent for mosquitoes. This investigation provides a survey of the basic diversity of EPNs and symbiotic bacteria in the National Park of Thailand, and it is a bacterial resource for further studies of bioactive compounds.

Symbiotic stars observed from the IRAS satellite

International Nuclear Information System (INIS)

Luud, L.; Tuvikene, T.

1987-01-01

Symbiotic stars according to Alfven's catalogue have been checked for coincidence with the IRAS-observed for-infrared sources. 72 symbiotic and possible symbiotic stars have been identified with the IRAS-observed sources. A catalogue of identified stars and energy distributions of representative stars are given. It turns out that the dust in symbiotic stars is a more widespread phenomenon than that it was believed before. Almost 40% of systems are the dusty ones. Among objects with dust temperature some tens of K have been found. It is shown that the only useful two-color diagram is (K-m 12 )-(m 12 -m 25 ). Attention is paid to a type of symbiotic stars with G spectral class cold component which needs special investigation

Association between Helicobacter pylori Infection and Chronic Urticaria: A Meta-Analysis

Directory of Open Access Journals (Sweden)

Huiyuan Gu

2015-01-01

Full Text Available Background. Some studies have shown the possible involvement of Helicobacter pylori (H. pylori infection in chronic urticaria, but the relationship remains controversial. The aim of this meta-analysis was to quantitatively assess the association between H. pylori infection and chronic urticaria. Methods. Observational studies comparing the prevalence of H. pylori infection in patients with chronic urticaria and control subjects were identified through a systematic search in MEDLINE and EMBASE up to July 2014. H. pylori infection was confirmed by serological or nonserological tests. For subgroup analyses, studies were separated by region, publication year, and H. pylori detection method to screen the potential factors resulting in heterogeneity. Results. 16 studies involving 965 CU cases and 1235 controls were included. Overall, the prevalence of H. pylori infection was higher in urticarial patients than in controls (OR = 1.66; 95% CI: 1.12–2.45; P=0.01. This result persisted in subanalysis of nine high-quality studies (OR = 1.36; 95% CI: 1.03–1.80; P=0.03. Subgroup analysis showed that detection method of H. pylori is also a potential influential factor for the overall results. Conclusions. Our present meta-analysis suggests that H. pylori infection is significantly, though weakly, associated with an increased risk of chronic urticaria.

Host-secreted antimicrobial peptide enforces symbiotic selectivity in Medicago truncatula.

Science.gov (United States)

Wang, Qi; Yang, Shengming; Liu, Jinge; Terecskei, Kata; Ábrahám, Edit; Gombár, Anikó; Domonkos, Ágota; Szűcs, Attila; Körmöczi, Péter; Wang, Ting; Fodor, Lili; Mao, Linyong; Fei, Zhangjun; Kondorosi, Éva; Kaló, Péter; Kereszt, Attila; Zhu, Hongyan

2017-06-27

Legumes engage in root nodule symbioses with nitrogen-fixing soil bacteria known as rhizobia. In nodule cells, bacteria are enclosed in membrane-bound vesicles called symbiosomes and differentiate into bacteroids that are capable of converting atmospheric nitrogen into ammonia. Bacteroid differentiation and prolonged intracellular survival are essential for development of functional nodules. However, in the Medicago truncatula - Sinorhizobium meliloti symbiosis, incompatibility between symbiotic partners frequently occurs, leading to the formation of infected nodules defective in nitrogen fixation (Fix - ). Here, we report the identification and cloning of the M. truncatula NFS2 gene that regulates this type of specificity pertaining to S. meliloti strain Rm41. We demonstrate that NFS2 encodes a nodule-specific cysteine-rich (NCR) peptide that acts to promote bacterial lysis after differentiation. The negative role of NFS2 in symbiosis is contingent on host genetic background and can be counteracted by other genes encoded by the host. This work extends the paradigm of NCR function to include the negative regulation of symbiotic persistence in host-strain interactions. Our data suggest that NCR peptides are host determinants of symbiotic specificity in M. truncatula and possibly in closely related legumes that form indeterminate nodules in which bacterial symbionts undergo terminal differentiation.

Low dose chronic Schistosoma mansoni infection increases susceptibility to Mycobacterium bovis BCG infection in mice

DEFF Research Database (Denmark)

Elias, D; Akuffo, H; Thors, C

2005-01-01

The incidence of mycobacterial diseases is high and the efficacy of Bacillus Calmette Guerin (BCG) is low in most areas of the world where chronic worm infections are common. However, if and how concurrent worm infections could affect immunity to mycobacterial infections has not been elucidated. ...

Perioperative synbiotics administration decreases postoperative infections in patients with colorectal cancer: a randomized, double-blind clinical trial

Directory of Open Access Journals (Sweden)

ALINE TABORDA FLESCH

Full Text Available ABSTRACT Objective: to evaluate the effect of perioperative administration of symbiotics on the incidence of surgical wound infection in patients undergoing surgery for colorectal cancer. Methods: We conducted a randomized clinical trial with colorectal cancer patients undergoing elective surgery, randomly assigned to receive symbiotics or placebo for five days prior to the surgical procedure and for 14 days after surgery. We studied 91 patients, 49 in the symbiotics group (Lactobacillus acidophilus 108 to 109 CFU, Lactobacillus rhamnosus 108 to 109 CFU, Lactobacillus casei 108 to 109 CFU, Bifi dobacterium 108 to 109 CFU and fructo-oligosaccharide (FOS 6g and 42 in the placebo group. Results: surgical site infection occurred in one (2% patient in the symbiotics group and in nine (21.4% patients in the control group (p=0.002. There were three cases of intraabdominal abscess and four cases of pneumonia in the control group, whereas we observed no infections in patients receiving symbiotics (p=0.001. Conclusion: the perioperative administration of symbiotics significantly reduced postoperative infection rates in patients with colorectal cancer. Additional studies are needed to confirm the role of symbiotics in the surgical treatment of colorectal cancer.

Spectrophotometric observations of symbiotic stars

International Nuclear Information System (INIS)

Ipatov, A.P.; Yudin, B.F.

1985-01-01

The data of spectrophotometric observations of symbiotic stars Z And, AX Per, CI Cyg, BF Cyg, YY Her, V 443 Her, AG Dra, AG Peg, AS 296, EG And, V 1016 Cyg, and HM Sge are presented. The spectral range of observations is 3300-7500 A, resolution is 50 A. The data obtained allowed to reveal specific characteristics inherent to the radiation of symbiotic stars and to estimate the parameters of their individual components. Analysis of the spectra of symbiotic stars in the range of 1300-7500 A wavelengths suggests a hypothesis, according to which a hot source in the Rayleigh - Jeans spectral range has a less steep inclination in the energy distribution, than a black-body one. A disk, formed during cold star substance accretion through an internal Lagrangian point onto a denser component of the system, can play the role of the source. In this case one manages to obtain the energy distribution in the symbiotic star spectrum consistent with the observed distribution

Cryptosporidiosis and other intestinal parasitic infections in patients with chronic diarrhea.

Science.gov (United States)

Mahdi, Nadham K; Ali, Naeel H

2004-09-01

To consider the relationship of the parasitic infections including cryptosporidium with chronic diarrhea. Also the effect of chronic disease as pulmonary tuberculosis (TB) and nosocomial infection on the occurrence rate of parasites in cases of chronic diarrhea. Stool samples were collected from 205 patients in teaching, general, child and maternity hospitals in Basrah, Iraq, suffering from chronic diarrhea during 2000. Out of these patients, there were 40 patients with pulmonary TB and 50 inpatients with nosocomial infection. Also 175 apparently healthy individuals who have no episodes of diarrhea for at least 2-months were served as a control group. Direct smear method and then formalin ether sedimentation method were carried out for stool samples to detect intestinal parasites. Fecal smears were prepared from the sediment and stained by the modified Ziehl Neelsen stain for the recovery of red pink oocysts of cryptosporidium. Out of the 205 examined patients, cryptosporidium oocysts were found to be excreted in 20 (9.7%) patients in comparing to 1.1% of the control group. The difference is statistically significant. There were 109 (53.2%) patients found to be positive for intestinal parasitic infections compared to 26 (14.8%) of the control group. The difference is also statistically significant. Out of the 40 TB patients, 2 (5%) were found to excrete cryptosporidium oocysts and also 27 (67.3%) were positive for intestinal parasites. In addition, there were 4 (8%) excreting cryptosporidium oocysts and 23 (46%) infecting by intestinal parasites among the in patients with nosocomial infection. Both acid and non-acid fast parasites should be considered in the differential diagnosis of undiagnosed chronic diarrhea especially among patients with pulmonary TB or nosocomial infection.

Phenotypes selected during chronic lung infection in cystic fibrosis patients

DEFF Research Database (Denmark)

Ciofu, Oana; Mandsberg, Lotte F; Wang, Hengzhuang

2012-01-01

During chronic lung infection of patients with cystic fibrosis, Pseudomonas aeruginosa can survive for long periods of time under the challenging selective pressure imposed by the immune system and antibiotic treatment as a result of its biofilm mode of growth and adaptive evolution mediated by g...... the importance of biofilm prevention strategies by early aggressive antibiotic prophylaxis or therapy before phenotypic diversification during chronic lung infection of patients with cystic fibrosis....

A Medicago truncatula tobacco retrotransposon insertion mutant collection with defects in nodule development and symbiotic nitrogen fixation.

Science.gov (United States)

Pislariu, Catalina I; Murray, Jeremy D; Wen, JiangQi; Cosson, Viviane; Muni, RajaSekhara Reddy Duvvuru; Wang, Mingyi; Benedito, Vagner A; Andriankaja, Andry; Cheng, Xiaofei; Jerez, Ivone Torres; Mondy, Samuel; Zhang, Shulan; Taylor, Mark E; Tadege, Million; Ratet, Pascal; Mysore, Kirankumar S; Chen, Rujin; Udvardi, Michael K

2012-08-01

A Tnt1-insertion mutant population of Medicago truncatula ecotype R108 was screened for defects in nodulation and symbiotic nitrogen fixation. Primary screening of 9,300 mutant lines yielded 317 lines with putative defects in nodule development and/or nitrogen fixation. Of these, 230 lines were rescreened, and 156 lines were confirmed with defective symbiotic nitrogen fixation. Mutants were sorted into six distinct phenotypic categories: 72 nonnodulating mutants (Nod-), 51 mutants with totally ineffective nodules (Nod+ Fix-), 17 mutants with partially ineffective nodules (Nod+ Fix+/-), 27 mutants defective in nodule emergence, elongation, and nitrogen fixation (Nod+/- Fix-), one mutant with delayed and reduced nodulation but effective in nitrogen fixation (dNod+/- Fix+), and 11 supernodulating mutants (Nod++Fix+/-). A total of 2,801 flanking sequence tags were generated from the 156 symbiotic mutant lines. Analysis of flanking sequence tags revealed 14 insertion alleles of the following known symbiotic genes: NODULE INCEPTION (NIN), DOESN'T MAKE INFECTIONS3 (DMI3/CCaMK), ERF REQUIRED FOR NODULATION, and SUPERNUMERARY NODULES (SUNN). In parallel, a polymerase chain reaction-based strategy was used to identify Tnt1 insertions in known symbiotic genes, which revealed 25 additional insertion alleles in the following genes: DMI1, DMI2, DMI3, NIN, NODULATION SIGNALING PATHWAY1 (NSP1), NSP2, SUNN, and SICKLE. Thirty-nine Nod- lines were also screened for arbuscular mycorrhizal symbiosis phenotypes, and 30 mutants exhibited defects in arbuscular mycorrhizal symbiosis. Morphological and developmental features of several new symbiotic mutants are reported. The collection of mutants described here is a source of novel alleles of known symbiotic genes and a resource for cloning novel symbiotic genes via Tnt1 tagging.

Congenital Toxoplasmosis in Chronically Infected and Subsequently Challenged Ewes.

Science.gov (United States)

Dos Santos, Thaís Rabelo; Faria, Gabriela da Silva Magalhães; Guerreiro, Bruna Martins; Dal Pietro, Nathalia Helena Pereira da Silva; Lopes, Welber Daniel Zanetti; da Silva, Helenara Machado; Garcia, João Luis; Luvizotto, Maria Cecília Rui; Bresciani, Katia Denise Saraiva; da Costa, Alvimar José

2016-01-01

This experiment studied congenital transmission in sheep experimentally infected with oocysts of Toxoplasma gondii and reinfected at one of three stages of pregnancy. Twenty ewes were experimentally infected with T. gondii strain ME49 (day 0). After the T. gondii infection became chronic (IFAT≤512), the ewes were allocated with rams for coverage. After the diagnosis of pregnancy, these ewes were allocated into four experimental groups (n = 5): I-reinfected with T. gondii on the 40th day of gestation (DG); II-reinfected on DG 80; III-reinfected on DG 120; and IV-saline solution on DG 120 (not reinfected). Five ewes (IFATewes produced lambs serologically positive for T. gondii. The results of the mouse bioassay, immunohistochemistry and PCR assays revealed the presence of T. gondii in all 20 sheep and their lambs. The congenital transmission of T. gondii was associated with fetal loss and abnormalities in persistently infected sheep and in ewes infected and subsequently reinfected by this protozoan. Therefore, congenital T. gondii infection was common when ewes were chronically infected prior to pregnancy, with or without reinfection during at various stages of gestation.

Chronic Infections of the Urinary Tract and Bladder Cancer Risk: a Systematic Review.

Science.gov (United States)

Anderson-Otunu, Oghenetejiri; Akhtar, Saeed

2016-01-01

Literature on the relationship between recurrent urinary tract infections and urinary bladder carcinoma risk has been inconsistent. Therefore, we carried out this systematic review of observational studies to ascertain if there is any association between chronic urinary tract infection and urinary bladder carcinoma. A total of 10 databases were searched using Boolean: CINAHL, PUBMED, Google Scholar, Medline, Science Direct, SCIRUS, Cochrane, UK PubMed central, NHS evidence and WHO-website. The search yielded an initial hit of 3,518 articles and after screening and critical appraisal, seven studies were included for this review. Four articles reported an association between chronic urinary tract infections and bladder cancer while three concluded a weak or no association at least in one gender. Main findings in this review were that most of the studies reported an association between chronic urinary tract infections and bladder cancer risk. However, inferences about the causal association between chronic urinary tract infections and bladder cancer risk should be drawn cautiously considering the methodological limitations of case-control studies included in this review. Therefore, more empirical evidence is needed to determine the causal nature of relationships between chronic urinary tract infections and bladder cancer risk.

Endosymbiont-based immunity in Drosophila melanogaster against parasitic nematode infection.

Science.gov (United States)

Yadav, Shruti; Frazer, Joanna; Banga, Ashima; Pruitt, Katherine; Harsh, Sneh; Jaenike, John; Eleftherianos, Ioannis

2018-01-01

Associations between endosymbiotic bacteria and their hosts represent a complex ecosystem within organisms ranging from humans to protozoa. Drosophila species are known to naturally harbor Wolbachia and Spiroplasma endosymbionts, which play a protective role against certain microbial infections. Here, we investigated whether the presence or absence of endosymbionts affects the immune response of Drosophila melanogaster larvae to infection by Steinernema carpocapsae nematodes carrying or lacking their mutualistic Gram-negative bacteria Xenorhabdus nematophila (symbiotic or axenic nematodes, respectively). We find that the presence of Wolbachia alone or together with Spiroplasma promotes the survival of larvae in response to infection with S. carpocapsae symbiotic nematodes, but not against axenic nematodes. We also find that Wolbachia numbers are reduced in Spiroplasma-free larvae infected with axenic compared to symbiotic nematodes, and they are also reduced in Spiroplasma-containing compared to Spiroplasma-free larvae infected with axenic nematodes. We further show that S. carpocapsae axenic nematode infection induces the Toll pathway in the absence of Wolbachia, and that symbiotic nematode infection leads to increased phenoloxidase activity in D. melanogaster larvae devoid of endosymbionts. Finally, infection with either type of nematode alters the metabolic status and the fat body lipid droplet size in D. melanogaster larvae containing only Wolbachia or both endosymbionts. Our results suggest an interaction between Wolbachia endosymbionts with the immune response of D. melanogaster against infection with the entomopathogenic nematodes S. carpocapsae. Results from this study indicate a complex interplay between insect hosts, endosymbiotic microbes and pathogenic organisms.

SS 383: A NEW S-TYPE YELLOW SYMBIOTIC STAR?

Energy Technology Data Exchange (ETDEWEB)

Baella, N. O.; Pereira, C. B. [Observatório Nacional, Rua José Cristino 77, CEP 20921-400, São Cristóvão, Rio de Janeiro (Brazil); Miranda, L. F. [Departamento de Física Aplicada, Facultad de Ciencias, Universidad de Vigo, E-36310 Vigo (Spain)

2013-11-01

Symbiotic stars are key objects in understanding the formation and evolution of interacting binary systems, and are probably the progenitors of Type Ia supernovae. However, the number of known symbiotic stars is much lower than predicted. We aim to search for new symbiotic stars, with particular emphasis on the S-type yellow symbiotic stars, in order to determine their total population, evolutionary timescales, and physical properties. The Two Micron All Sky Survey (2MASS) (J – H) versus (H – K {sub s}) color-color diagram has been previously used to identify new symbiotic star candidates and show that yellow symbiotics are located in a particular region of that diagram. Candidate symbiotic stars are selected on the basis of their locus in the 2MASS (J – H) versus (H – K {sub s}) diagram and the presence of Hα line emission in the Stephenson and Sanduleak Hα survey. This diagram separates S-type yellow symbiotic stars from the rest of the S-type symbiotic stars, allowing us to select candidate yellow symbiotics. To establish the true nature of the candidates, intermediate-resolution spectroscopy is obtained. We have identified the Hα emission line source SS 383 as an S-type yellow symbiotic candidate by its position in the 2MASS color-color diagram. The optical spectrum of SS 383 shows Balmer, He I, He II, and [O III] emission lines, in combination with TiO absorption bands that confirm its symbiotic nature. The derived electron density (≅10{sup 8-9} cm{sup –3}), He I emission line intensity ratios, and position in the [O III] λ5007/Hβ versus [O III] λ4363/Hγ diagram indicate that SS 383 is an S-type symbiotic star, with a probable spectral type of K7-M0 deduced for its cool component based on TiO indices. The spectral type and the position of SS 383 (corrected for reddening) in the 2MASS color-color diagram strongly suggest that SS 383 is an S-type yellow symbiotic. Our result points out that the 2MASS color-color diagram is a powerful tool in

SS 383: A NEW S-TYPE YELLOW SYMBIOTIC STAR?

International Nuclear Information System (INIS)

Baella, N. O.; Pereira, C. B.; Miranda, L. F.

2013-01-01

Symbiotic stars are key objects in understanding the formation and evolution of interacting binary systems, and are probably the progenitors of Type Ia supernovae. However, the number of known symbiotic stars is much lower than predicted. We aim to search for new symbiotic stars, with particular emphasis on the S-type yellow symbiotic stars, in order to determine their total population, evolutionary timescales, and physical properties. The Two Micron All Sky Survey (2MASS) (J – H) versus (H – K s ) color-color diagram has been previously used to identify new symbiotic star candidates and show that yellow symbiotics are located in a particular region of that diagram. Candidate symbiotic stars are selected on the basis of their locus in the 2MASS (J – H) versus (H – K s ) diagram and the presence of Hα line emission in the Stephenson and Sanduleak Hα survey. This diagram separates S-type yellow symbiotic stars from the rest of the S-type symbiotic stars, allowing us to select candidate yellow symbiotics. To establish the true nature of the candidates, intermediate-resolution spectroscopy is obtained. We have identified the Hα emission line source SS 383 as an S-type yellow symbiotic candidate by its position in the 2MASS color-color diagram. The optical spectrum of SS 383 shows Balmer, He I, He II, and [O III] emission lines, in combination with TiO absorption bands that confirm its symbiotic nature. The derived electron density (≅10 8-9 cm –3 ), He I emission line intensity ratios, and position in the [O III] λ5007/Hβ versus [O III] λ4363/Hγ diagram indicate that SS 383 is an S-type symbiotic star, with a probable spectral type of K7-M0 deduced for its cool component based on TiO indices. The spectral type and the position of SS 383 (corrected for reddening) in the 2MASS color-color diagram strongly suggest that SS 383 is an S-type yellow symbiotic. Our result points out that the 2MASS color-color diagram is a powerful tool in identifying new S

Properties of the cold components of symbiotic stars

International Nuclear Information System (INIS)

Luud, L.; Leedyarv, L.

1986-01-01

The basic physical parameters of the cold components of symbiotic stars and comparison red giants have been determined from the data of infrared photometry by means of the Blackwell-Shallis method. It is found that the cold components of the symbiotic stars do not differ from normal red giants of the asymptotic branch. The masses of the cold components of the symbiotic stars are close to 3M. The red components of the symbiotic stars do not fill their Roche lobes. Among the cold components of the symbiotic stars, there are approximately ten times as many carbon stars as among the red giants in the neighborhood of the Sun

Construction and symbiotic competence of a luxA-deletion mutant of Vibrio fischeri.

Science.gov (United States)

Visick, K G; Ruby, E G

1996-10-10

Bioluminescence by the squid Euprymna scolopes requires colonization of its light organ by the symbiotic luminous bacterium Vibrio fischeri. Investigation of the genetic determinants underlying bacterial symbiotic competence in this system has necessitated the continuing establishment and application of molecular genetic techniques in V. fischeri. We developed a procedure for the introduction of plasmid DNA into V. fischeri by electroporation, and isolated a mutant strain that overcame the apparent restriction barrier between V. fischeri and Escherichia coli. Using the technique of electroporation in combination with that of gene replacement, we constructed a non-luminous strain of V. fischeri (delta luxA::erm). In addition, we used the transducing phage rp-1 for the first time to transfer a chromosomal antibiotic resistance marker to another strain of V. fischeri. The luxA mutant was able to colonize E. scolopes as quickly and to the same extent as wild type. This result suggested that, at least during the initial stages of colonization, luminescence per se is not an essential factor for the symbiotic infection.

PREVALENCE OF MALNUTRITION IN CHILDREN WITH CHRONIC HEPATITIS B INFECTION.

Science.gov (United States)

Şahin, Yasin

2016-01-01

There have been limited studies investigating the impact of chronic hepatitis B virus infection on the growth of children. Our objective was to investigate the prevalence of malnutrition in children with chronic hepatitis B infection. The nutritional status of patients was retrospectively evaluated in the outpatient Clinic of Pediatric Gastroenterology between February and November 2014. During the study, biochemical laboratory parameters, duration of disease, liver biopsy scores, and medication were evaluated. Additionally body mass index and body mass index centiles were calculated. Of the 96 patients in this study, 68 were male and 28 were female, and the mean age was 144.7±43.9 months and 146.1±47.3 months, respectively. According to body mass index centiles five (5.2%) patients were underweight, seven (7.3%) patients were overweight, and seven (7.3%) patients were obese. Moderate rates of malnutrition (including obesity) were found in chronic hepatitis B infection. Additional nutritional status information of healthy and sick children should be assessed in the infection's early period, and timely interventions should be initiated.

Interacting Winds in Eclipsing Symbiotic Systems

Indian Academy of Sciences (India)

2016-01-27

Jan 27, 2016 ... Interacting Winds in Eclipsing Symbiotic Systems – The Case Study of EG Andromedae ... to obtain the physical parameters of a quiescent eclipsing symbiotic system. ... Articles are also visible in Web of Science immediately.

UV line emission of symbiotic stars

International Nuclear Information System (INIS)

Nussbaumer, H.

1982-01-01

General characteristics of emission line spectra from symbiotic stars are outlined. Data from some special line ratios in the 1000 A - 3000 A range, and others connecting the visual and the far UV lines are presented, and their application to symbiotic stars is discussed. Integrated fractional abundances for ions easily observed in the far UV are given to facilitate abundance determinations for nebular conditions. It is found that the physical conditions of the regions emitting the emission line spectra differ considerably among different symbiotic stars. (Auth.)

Chronic hepatitis E virus infection in liver transplant recipients

NARCIS (Netherlands)

Haagsma, Elizabeth B.; van den Berg, Arie P.; Porte, Robert J.; Benne, Cornelis A.; Vennema, Harry; Reimerink, Johan H. J.; Koopmans, Marion P. G.

Hepatitis E virus (HEV) infection is known to run a self-limiting course. Sporadic cases of acute hepatitis due to infection with HEV genotype 3, present in pig populations, are increasingly recognized. Zoonotic transmission seems infrequent. The entity of unexplained chronic hepatitis after liver

Revisiting Symbiotic Job Scheduling

OpenAIRE

Eyerman , Stijn; Michaud , Pierre; Rogiest , Wouter

2015-01-01

International audience; —Symbiotic job scheduling exploits the fact that in a system with shared resources, the performance of jobs is impacted by the behavior of other co-running jobs. By coscheduling combinations of jobs that have low interference, the performance of a system can be increased. In this paper, we investigate the impact of using symbiotic job scheduling for increasing throughput. We find that even for a theoretically optimal scheduler, this impact is very low, despite the subs...

Salmonella Typhimurium gastroenteritis leading to chronic prosthetic vascular graft infection.

Science.gov (United States)

Cullinan, Milo; Clarke, Michael; Dallman, Tim; Peart, Steven; Wilson, Deborah; Weiand, Daniel

2017-08-01

Introduction. It is estimated up to 6 % of prosthetic vascular grafts become infected. Staphylococcus aureus is predominant in early infection and coagulase-negative staphylococci are predominant in late infections. Enterobacteriaceae cause 14-40 % of prosthetic vascular graft infections. This is, to our knowledge the first reported case of Salmonella gastroenteritis causing chronic prosthetic vascular graft infection (PVGI). Case presentation. A 57 years old lady presented with signs and symptoms of prosthetic vascular graft infection. Three years earlier, she had undergone a prosthetic axillo-femoral bypass graft for critical limb ischaemia. The infected prosthetic vascular graft was removed and Salmonella Typhimurium was isolated on culture. In the intervening period, Salmonella Typhimurium was isolated from a faecal specimen, collected during an episode of acute gastroenteritis. Whole-genome sequencing (WGS) showed that the respective Salmonella Typhimurium isolates differed by only a single nucleotide polymorphism (SNP). Salmonella Typhimurium was not isolated on culture of a faecal specimen collected five days following cessation of antimicrobial therapy. Six months after removal of the prosthetic graft, the patient remains under follow-up for her peripheral vascular disease, which currently requires no further surgical intervention. Conclusion. This case has clear implications for the management of chronic PVGI. It is vital to collect high-quality surgical specimens for microbiological analysis and empirical choices of antibiotics are unlikely to cover all potential pathogens. It may also be prudent to enquire about a history of acute gastroenteritis when assessing patients presenting with chronic PVGI.

Does bovine besnoitiosis affect the sexual function of chronically infected bulls?

Science.gov (United States)

Esteban-Gil, A; Jacquiet, P; Florentin, S; Decaudin, A; Berthelot, X; Ronsin, P; Grisez, C; Prevot, F; Alzieu, J P; Marois, M; Corboz, N; Peglion, M; Vilardell, C; Liénard, E; Bouhsira, E; Castillo, J A; Franc, M; Picard-Hagen, N

2016-09-15

Bovine besnoitiosis is a reemerging disease in Europe. The clinically Besnoitia besnoiti infection in bulls is characterized by fever, nasal discharge, and orchitis in the acute phase and by scleroderma in the chronic phase. However, in many bulls, B besnoiti infection remains at a subclinical stage. Bull infertility is an economically relevant consequence of besnoitiosis infection. It is not clear, however, if semen quality returns to normal levels when infected animals have clinically recovered. The aim of this study was to examine the relationship between chronic besnoitiosis and bull sexual function in a region of eastern France, where the disease is reemerging, by comparing semen quality and genital lesions in 11 uninfected, 17 subclinically infected, and 12 clinically infected bulls. The presence of anti-B besnoiti antibodies was detected by Western blot test. Semen was collected by electroejaculation. Bulls clinically infected with B besnoiti showed significantly more genital tract alterations than uninfected or subclinically infected bulls. No relationship was evidenced between besnoitiosis infectious status and semen quality, whereas a significant relationship was noted between genital lesions and semen score. This means that in the absence of moderate to severe genital lesions, chronic bovine besnoitiosis is unlikely to alter semen quality. However, as the presence of infected animals could lead to spread of the disease, culling or separation of clinically infected bulls from the remaining healthy animals is strongly recommended. Copyright © 2016 Elsevier Inc. All rights reserved.

The evolutionary status of symbiotic stars

International Nuclear Information System (INIS)

Rudak, B.

1982-01-01

The evolutionary relations between symbiotic stars and cataclysmic variables are presented. The symbiotic stars are assumed to be long period detached binaries containing a carbon-oxygen degenerate primary and a red giant losing its mass through a spherically symmetric wind. Such systems can be obtained in Case C evolution, provided a common envelope during a rapid mass transfer phase was not formed. The same way recurrent novae containing a red giant as a secondary component may be produced. The factors influencing the differences between symbiotic stars and nova-type stars are discussed. (Auth.)

Symbiotic leghemoglobins are crucial for nitrogen fixation in legume root nodules but not for general plant growth and development

DEFF Research Database (Denmark)

Ott, Thomas; van Dongen, Joost T; Günther, Catrin

2005-01-01

Hemoglobins are ubiquitous in nature and among the best-characterized proteins. Genetics has revealed crucial roles for human hemoglobins, but similar data are lacking for plants. Plants contain symbiotic and nonsymbiotic hemoglobins; the former are thought to be important for symbiotic nitrogen...... fixation (SNF). In legumes, SNF occurs in specialized organs, called nodules, which contain millions of nitrogen-fixing rhizobia, called bacteroids. The induction of nodule-specific plant genes, including those encoding symbiotic leghemoglobins (Lb), accompanies nodule development. Leghemoglobins...... accumulate to millimolar concentrations in the cytoplasm of infected plant cells prior to nitrogen fixation and are thought to buffer free oxygen in the nanomolar range, avoiding inactivation of oxygen-labile nitrogenase while maintaining high oxygen flux for respiration. Although widely accepted...

Proteomic Analysis of Leptospira interrogans Shed in Urine of Chronically Infected Hosts▿

OpenAIRE

Monahan, Avril M.; Callanan, John J.; Nally, Jarlath E.

2008-01-01

Leptospirosis is a global zoonotic disease. The causative agent, pathogenic Leptospira species, survives in the renal tubules of chronically infected hosts, from where leptospires are shed via urine into the environment. Infection of new hosts can present as an array of acute and chronic disease processes reflecting variations in host-pathogen interactions. The present study was designed to reproduce the carrier phase of infection in Rattus norvegicus, thus facilitating shedding of leptospire...

75 FR 55797 - Draft Guidance for Industry on Chronic Hepatitis C Virus Infection: Developing Direct-Acting...

Science.gov (United States)

2010-09-14

...] Draft Guidance for Industry on Chronic Hepatitis C Virus Infection: Developing Direct-Acting Antiviral... entitled ``Chronic Hepatitis C Virus Infection: Developing Direct-Acting Antiviral Agents for Treatment... announcing the availability of a draft guidance for industry entitled ``Chronic Hepatitis C Virus Infection...

Autoimmune and Neoplastic Thyroid Diseases Associated with Hepatitis C Chronic Infection

Directory of Open Access Journals (Sweden)

Poupak Fallahi

2014-01-01

Full Text Available Frequently, patients with hepatitis C virus (HCV chronic infection have high levels of serum anti-thyroperoxidase and/or anti-thyroglobulin autoantibodies, ultrasonographic signs of chronic autoimmune thyroiditis, and subclinical hypothyroidism, in female gender versus healthy controls, or hepatitis B virus infected patients. In patients with “HCV-associated mixed cryoglobulinemia” (MC + HCV, a higher prevalence of thyroid autoimmune disorders was shown not only compared to controls, but also versus HCV patients without cryoglobulinemia. Patients with MC + HCV or HCV chronic infection show a higher prevalence of papillary thyroid cancer than controls, in particular in patients with autoimmune thyroiditis. Patients with HCV chronic infection, or with MC + HCV, in presence of autoimmune thyroiditis, show higher serum levels of T-helper (Th1 (C-X-C motif ligand 10 (CXCL10 chemokine, but normal levels of Th2 (C-C motif ligand 2 chemokine, than patients without thyroiditis. HCV thyroid infection could act by upregulating CXCL10 gene expression and secretion in thyrocytes recruiting Th1 lymphocytes that secrete interferon-γ and tumor necrosis factor-α. These cytokines might induce a further CXCL10 secretion by thyrocytes, thus perpetuating the immune cascade, which may lead to the appearance of autoimmune thyroid disorders in genetically predisposed subjects. A careful monitoring of thyroid function, particularly where nodules occur, is recommended in HCV patients.

Symbiotic star H1-36

Energy Technology Data Exchange (ETDEWEB)

Allen, D A

1983-01-01

It is suggested that H1-36 should be classified as a symbiotic star rather than a planetary nebula. Evidence of a cool giant now exists and the high-excitation emission-line spectrum resembles the spectra of many symbiotic stars. The optical spectrum, radio spectrum, high spectral index of +0.9 and computed mass-loss rate are among the features discussed.

Spectrophotometry of Symbiotic Stars (Abstract)

Science.gov (United States)

Boyd, D.

2017-12-01

(Abstract only) Symbiotic stars are fascinating objects - complex binary systems comprising a cool red giant star and a small hot object, often a white dwarf, both embedded in a nebula formed by a wind from the giant star. UV radiation from the hot star ionizes the nebula, producing a range of emission lines. These objects have composite spectra with contributions from both stars plus the nebula and these spectra can change on many timescales. Being moderately bright, they lend themselves well to amateur spectroscopy. This paper describes the symbiotic star phenomenon, shows how spectrophotometry can be used to extract astrophysically useful information about the nature of these systems, and gives results for three symbiotic stars based on the author's observations.

Chronic Hepatitis B and C Virus Infection and Risk for Non-Hodgkin Lymphoma in HIV-Infected Patients

DEFF Research Database (Denmark)

Wang, Qing; De Luca, Andrea; Smith, Colette

2017-01-01

Background: Non-Hodgkin lymphoma (NHL) is the most common AIDS-defining condition in the era of antiretroviral therapy (ART). Whether chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infection promote NHL in HIV-infected patients is unclear. Objective: To investigate whether chronic HBV...... and HCV infection are associated with increased incidence of NHL in HIV-infected patients. Design: Cohort study. Setting: 18 of 33 cohorts from the Collaboration of Observational HIV Epidemiological Research Europe (COHERE). Patients: HIV-infected patients with information on HBV surface antigen...... measurements and detectable HCV RNA, or a positive HCV antibody test result if HCV RNA measurements were not available. Measurements: Time-dependent Cox models to assess risk for NHL in treatment-naive patients and those initiating ART, with inverse probability weighting to control for informative censoring...

Chronic obstructive pulmonary disease and risk of infection

DEFF Research Database (Denmark)

Lange, Peter

2009-01-01

This review article focuses on the risk of infections in patients with chronic obstructive pulmonary disease (COPD). Throughout the years there have been a number of studies describing the risk of pulmonary infections in patients with COPD, whereas only few studies have focused on the risk...... of infection outside the lungs. With increasing severity of COPD the risk of respiratory tract infection also increases. The impairment of the innate immune system is most likely responsible for both the colonization of respiratory tract with bacteria and for an increased risk of infection with new strains...... of bacteria causing acute exacerbations. Also lung infections like pneumonia, lung abscess and empyema are more often seen in patients with COPD than in healthy subjects. With regard to extrapulmonary infections, it seems that COPD patients are not at higher risk of infection compared with subjects without...

On the model of symbiotic stars

International Nuclear Information System (INIS)

Tutukov, A.V.; Yungelson, L.R.

1982-01-01

The authors discuss conditions necessary for appearance and discovery of the symbiotic star phenomenon within the model of a binary consisting of a red (super)giant 3 solar masses not filling the Roche lobe and of an accreting hot degenerate CO-dwarf 0.8 solar masses. Within this model ''classical'' symbiotic stars may exist only within a narrow region of mass accretion rates and separations of components: 10 -7 approximately -7 solar masses/y and 3x10 13 approximately 14 cm. The evolutionary status of symbiotic stars and related objects and the mechanisms of their variability are discussed. (Auth.)

lowered serum triglyceride levels among chronic hepatitis b-infected

African Journals Online (AJOL)

User

about the effect of the two pathological stages of chronic hepatitis B (CHB) infection – chronic- symptomatic and ... 2 hepatitis B disease and plasma metabolite dys- regulation has become the subject of interest by most biomedical researchers over the past dec- ade. The liver as a ..... leukin – 1, and interferon – α stimulate.

Symbiotic and antibiotic interactions between gut commensal microbiota and host immune system

Directory of Open Access Journals (Sweden)

Mantas Kazimieras Malys

2015-01-01

Full Text Available The human gut commensal microbiota forms a complex population of microorganisms that survive by maintaining a symbiotic relationship with the host. Amongst the metabolic benefits it brings, formation of adaptive immune system and maintenance of its homeostasis are functions that play an important role. This review discusses the integral elements of commensal microbiota that stimulate responses of different parts of the immune system and lead to health or disease. It aims to establish conditions and factors that contribute to gut commensal microbiota's transformation from symbiotic to antibiotic relationship with human. We suggest that the host-microbiota relationship has been evolved to benefit both parties and any changes that may lead to disease, are not due to unfriendly properties of the gut microbiota but due to host genetics or environmental changes such as diet or infection.

Sofosbuvir based treatment of chronic hepatitis C genotype 3 infections

DEFF Research Database (Denmark)

Dalgard, Olav; Weiland, Ola; Noraberg, Geir

2017-01-01

BACKGROUND AND AIMS: Chronic hepatitis C virus (HCV) genotype 3 infection with advanced liver disease has emerged as the most challenging to treat. We retrospectively assessed the treatment outcome of sofosbuvir (SOF) based regimes for treatment of HCV genotype 3 infections in a real life setting...... in Scandinavia. METHODS: Consecutive patients with chronic HCV genotype 3 infection were enrolled at 16 treatment centers in Denmark, Sweden, Norway and Finland. Patients who had received a SOF containing regimen were included. The fibrosis stage was evaluated by liver biopsy or transient liver elastography...... was similar for all treatment regimens, but lower in men (p = 0.042), and in patients with decompensated liver disease (p = 0.004). CONCLUSION: We found that sofosbuvir based treatment in a real-life setting could offer SVR rates exceeding 90% in patients with HCV genotype 3 infection and advanced liver...

CD4 T Cell Responses in Latent and Chronic Viral Infections

Science.gov (United States)

Walton, Senta; Mandaric, Sanja; Oxenius, Annette

2013-01-01

The spectrum of tasks which is fulfilled by CD4 T cells in the setting of viral infections is large, ranging from support of CD8 T cells and humoral immunity to exertion of direct antiviral effector functions. While our knowledge about the differentiation pathways, plasticity, and memory of CD4 T cell responses upon acute infections or immunizations has significantly increased during the past years, much less is still known about CD4 T cell differentiation and their beneficial or pathological functions during persistent viral infections. In this review we summarize current knowledge about the differentiation, direct or indirect antiviral effector functions, and the regulation of virus-specific CD4 T cells in the setting of persistent latent or active chronic viral infections with a particular emphasis on herpes virus infections for the former and chronic lymphocytic choriomeningitis virus infection for the latter. PMID:23717308

Poliovirus mutants excreted by a chronically infected hypogammaglobulinemic patient establish persistent infections in human intestinal cells

International Nuclear Information System (INIS)

Labadie, Karine; Pelletier, Isabelle; Saulnier, Aure; Martin, Javier; Colbere-Garapin, Florence

2004-01-01

Immunodeficient patients whose gut is chronically infected by vaccine-derived poliovirus (VDPV) may excrete large amounts of virus for years. To investigate how poliovirus (PV) establishes chronic infections in the gut, we tested whether it is possible to establish persistent VDPV infections in human intestinal Caco-2 cells. Four type 3 VDPV mutants, representative of the viral evolution in the gut of a hypogammaglobulinemic patient over almost 2 years [J. Virol. 74 (2000) 3001], were used to infect both undifferentiated, dividing cells, and differentiated, polarized enterocytes. A VDPV mutant excreted 36 days postvaccination by the patient was lytic in both types of intestinal cell cultures, like the parental Sabin 3 (S3) strain. In contrast, three VDPVs excreted 136, 442, and 637 days postvaccination, established persistent infections both in undifferentiated cells and in enterocytes. Thus, viral determinants selected between day 36 and 136 conferred on VDPV mutants the capacity to infect intestinal cells persistently. The percentage of persistently VDPV-infected cultures was higher in enterocytes than in undifferentiated cells, implicating cellular determinants involved in the differentiation of enterocytes in persistent VDPV infections. The establishment of persistent infections in enterocytes was not due to poor replication of VDPVs in these cells, but was associated with reduced viral adsorption to the cell surface

The infrared variability and nature of symbiotic stars

International Nuclear Information System (INIS)

Feast, M.W.; Catchpole, R.M.; Whitelock, P.A.; Carter, B.S.; Roberts, G.

1983-01-01

Infrared variability and spectra show that the symbiotic systems (He 2-106, He 2-38, He 2-34) contain Mira variable components. The first two also show a longer term infrared variability. It is suggested that this is due to variable dust obscuration (as in R Aqr). The phenomenon is then too frequent for the dust clouds to be confined to the orbital planes of the binary systems. Seven Miras in symbiotics have known periods which range from 370 to 580 days, suggesting a greater frequency of long-period Miras in symbiotics than in the general field. Symbiotic Miras have dust excesses with colour temperatures near 1000 K. Observations of four other symbiotic systems (Pe 2-3, He 2-87, H 2-5, AG Peg) are consistent with their containing non-variable or low amplitude M-type components. (author)

Clinical Holistic Medicine: Chronic Infections and Autoimmune Diseases

OpenAIRE

Ventegodt, Søren; Merrick, Joav

2005-01-01

The consciousness-based (holistic) medical toolbox might be useful in general practice and in cases of recurrent infections and chronic infection or inflammation. From our clinical experiences, there is hope for improvement from a number of diseases caused by disorders affecting the regulation of the immune system when the physician includes the holistic medical approach.Our scientific understanding of the connection between consciousness and cellular order is still limited. Consciousness-bas...

Symbiotic Miras

International Nuclear Information System (INIS)

Whitelock, P.A.

1987-01-01

This paper concerns interacting binary systems involving Mira variables. Twenty-six objects which potentially fall into this category are identified and observations of them covering the spectral regions from X-ray to radio are reviewed. Particular emphasis is given to near-infrared observations which are pertinent to establishing the presence of a Mira variable and also to new far-infrared data from IRAS. The majority of the objects under consideration have been classified as symbiotic stars. They are closely related to the well-known binary, o Cet, which might be described as mildly symbiotic. It is shown how the knowledge of normal Miras can contribute to the understanding of the evolutionary condition and luminosities of these binary Miras. Distances are derived for those objects with measured pulsation periods. The significance of the relatively long pulsation periods shown by these objects is also discussed. 165 references

Chronic Pseudomonas aeruginosa lung infection in normal and athymic rats

DEFF Research Database (Denmark)

Johansen, H K; Espersen, F; Pedersen, S S

1993-01-01

We have compared a chronic lung infection with Pseudomonas aeruginosa embedded in alginate beads in normal and athymic rats with an acute infection with free live P. aeruginosa bacteria. The following parameters were observed and described: mortality, macroscopic and microscopic pathologic changes...

Anti-soluble liver antigen (SLA) antibodies in chronic HCV infection.

Science.gov (United States)

Vitozzi, Susana; Lapierre, Pascal; Djilali-Saiah, Idriss; Marceau, Gabriel; Beland, Kathie; Alvarez, Fernando

2004-05-01

Hepatitis C infection is associated with autoimmune disorders, such as the production of autoantibodies. Anti-LKM1 and anti-LC1, immunomarkers of type 2 autoimmune hepatitis, have been previously associated with a HCV infection. Anti-Soluble-Liver-Antigen autoantibodies (SLA) are specifically associated with type 1 and type 2 autoimmune hepatitis and more closely related to patients who relapse after steroid therapy. The recent molecular cloning of the soluble liver antigen provides the opportunity to develop more specific tests for the detection of antibodies against it. The aim of this work is to characterize anti-soluble-liver autoantibodies in sera from patients chronically infected by HCV. A recombinant cDNA from activated Jurkat cells coding for the full length tRNP(Ser)Sec/SLA antigen was obtained. ELISA, Western Blot and immunoprecipitation tests were developed and used to search for linear and conformational epitopes recognized by anti-SLA antibodies in sera from patients chronically infected by HCV. Anti-soluble liver antigen antibodies were found in sera from 10.4% of HCV-infected patients. The prevalence was significantly increased to 27% when anti-LKM1 was also present. Most anti-SLA reactivity was directed against conformational epitopes on the antigen. The means titers by ELISA were lower than those obtained in type 2 AIH. The result of autoantibody isotyping showed a subclass restriction to IgG1 and also IgG4. This study shows the presence of anti-SLA antibodies in approximately 10% of HCV infected patients. The prevalence of SLA autoantibodies in HCV infected patients increases when LKM1 autoantibodies are also present. The relationship between the prevalence of this characteristic autoimmune hepatitis autoantibody and the implication of an autoimmune phenomenon in the liver injury of patients chronically infected by HCV needs further investigation.

Morula-like cells in photo-symbiotic clams harboring zooxanthellae.

Science.gov (United States)

Nakayama, K; Nishijima, M; Maruyama, T

1998-06-01

Symbiosis is observed between zooxanthellae, symbiotic dinoflagellates, and giant clams and related clams which belong to the families Tridacnidae and Cardiidae. We have previously shown that a photo-symbiotic clam Tridacna crocea has three types of hemocytes, the eosinophilic granular hemocyte with phagocytic activity, the agranular cell with electron lucent granules, and the morula-like cell with large (ca. 2 mum in diameter) colorless granules. The function of the morula-like cell is not clear, but it has not been reported in any other bivalves except photo-symbiotic clams T. crocea and Tridacna maxima. In order to clarify whether it is specific to photo-symbiotic clams or not, we studied hemocytes in the photo-symbiotic clams Tridacna derasa (Tridacnidae), Hippopus hippopus (Tridacnidae) and Corculum cardissa (Cardiidae), and a closely related non-symbiotic clam Fulvia mutica (Cardiidae). The eosinophilic granular hemocytes and the agranular cells were found in all of the clams examined. However, the morula-like cells which were packed with many large electron dense granules (ca. 2 mum in diameter), were observed only in the photo-symbiotic clams. In F. mutica, a closely related non-symbiotic clam, this type of hemocyte was not found. Instead a hemocyte with vacuoles and a few large granules containing peroxidase activity was observed. The large granules of F. mutica varied in size from ca. 1-9 mum in diameter. Present data suggests that the presence of morula-like cells is restricted to photo-symbiotic clams and that the hemocytes associated with the morula-like cells may have some functional relationship to symbiosis with zooxanthellae.

Effects of adding ribavirin to interferon to treat chronic hepatitis C infection

DEFF Research Database (Denmark)

Brok, Jesper; Gluud, Lise L; Gluud, Christian

2005-01-01

Evidence shows that a combination therapy of ribavirin plus interferon clears hepatitis C virus from the blood in about 40% of patients with chronic hepatitis C infection, but the effects on clinical outcomes are unclear. We evaluated the beneficial and harmful effects of ribavirin plus interferon...... vs interferon alone for treatment of patients with chronic hepatitis C infection. Randomized trials were included irrespective of blinding, language, or publication status. Trials were identified through the Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Library, MEDLINE....... In conclusion, the effect of ribavirin plus interferon on viral clearance may lead to reduced mortality and morbidity in patients with chronic hepatitis C infection. However, combination therapy is associated with increased risk for adverse events....

Hepatitis virus infection and chronic liver disease among atomic-bomb survivors

International Nuclear Information System (INIS)

Fujiwara, Saeko; Cologne, John; Akahoshi, Masazumi; Kusumi, Shizuyo; Kodama, Kazunori; Yoshizawa, Hiroshi

2000-01-01

Hepatitis C and B virus (HCV, HBV) infection plays a crucial role in the etiology of chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma, which have been reported to increase with radiation dose among the atomic bomb survivors. The purpose of this study is to investigate whether radiation exposure altered the prevalence of hepatitis virus infection or accelerated the progress toward chronic hepatitis after hepatitis virus infection. Levels of serum antibody to hepatitis C virus (anti-HCV), HBs antigen (HBsAg), and anti-HBs antibody (anti-HBs) were measured for 6,121 participants in the Adult Health Study of atomic bomb survivors in Hiroshima and Nagasaki. No relationship was found between anti-HCV prevalence and radiation dose, after adjusting for age, sex, city, history of blood transfusion, acupuncture, and family history, but prevalence of anti-HCV was significantly lower overall among the radiation-exposed people (relative prevalence 0.84, p=0.022) compared to people with estimated radiation dose 0 Gy. No significant interaction was found between any of the above mentioned risk factors and radiation dose. People with anti-HCV positive had 13 times higher prevalence of chronic liver disease than those without anti-HCV. However, the radiation dose response for chronic liver disease among anti-HCV positive survivors may be greater than that among anti-HCV negative survivors (slope ratio 20), but the difference was marginally significant (p=0.097). Prevalence of HBsAg increased with whole-body kerma. However, no trend with radiation dose was found in the anti-HBs prevalence. In the background, prevalence of chronic liver disease in people with HBsAg-positive was approximately three times higher that in those without HBsAg. No difference in slope of the dose was found among HBsAg positive and negative individuals (slope: HBsAg positive 0.91/Gy, HBsAg negative 0.11/Gy, difference p=0.66). In conclusion, no dose-response relationship was found between

Hepatitis virus infection and chronic liver disease among atomic-bomb survivors

Energy Technology Data Exchange (ETDEWEB)

Fujiwara, Saeko; Cologne, John; Akahoshi, Masazumi [Radiation Effects Research Foundation, Hiroshima (Japan); Kusumi, Shizuyo [Institute of Radiation Epidemiology, Radiation Effects Association, Tokyo (Japan); Kodama, Kazunori; Yoshizawa, Hiroshi [Hiroshima University School of Medicine, Hiroshima (Japan)

2000-05-01

Hepatitis C and B virus (HCV, HBV) infection plays a crucial role in the etiology of chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma, which have been reported to increase with radiation dose among the atomic bomb survivors. The purpose of this study is to investigate whether radiation exposure altered the prevalence of hepatitis virus infection or accelerated the progress toward chronic hepatitis after hepatitis virus infection. Levels of serum antibody to hepatitis C virus (anti-HCV), HBs antigen (HBsAg), and anti-HBs antibody (anti-HBs) were measured for 6,121 participants in the Adult Health Study of atomic bomb survivors in Hiroshima and Nagasaki. No relationship was found between anti-HCV prevalence and radiation dose, after adjusting for age, sex, city, history of blood transfusion, acupuncture, and family history, but prevalence of anti-HCV was significantly lower overall among the radiation-exposed people (relative prevalence 0.84, p=0.022) compared to people with estimated radiation dose 0 Gy. No significant interaction was found between any of the above mentioned risk factors and radiation dose. People with anti-HCV positive had 13 times higher prevalence of chronic liver disease than those without anti-HCV. However, the radiation dose response for chronic liver disease among anti-HCV positive survivors may be greater than that among anti-HCV negative survivors (slope ratio 20), but the difference was marginally significant (p=0.097). Prevalence of HBsAg increased with whole-body kerma. However, no trend with radiation dose was found in the anti-HBs prevalence. In the background, prevalence of chronic liver disease in people with HBsAg-positive was approximately three times higher that in those without HBsAg. No difference in slope of the dose was found among HBsAg positive and negative individuals (slope: HBsAg positive 0.91/Gy, HBsAg negative 0.11/Gy, difference p=0.66). In conclusion, no dose-response relationship was found between

Routine one-stage exchange for chronic infection after total hip replacement.

Science.gov (United States)

Jenny, Jean-Yves; Lengert, Régis; Diesinger, Yann; Gaudias, Jeannot; Boeri, Cyril; Kempf, Jean-François

2014-12-01

We hypothesized that a routine one-stage exchange for treatment of chronically infected total hip replacement (THR) will lead to (1) a higher rate of infection recurrence and (2) a poorer hip outcome than the published rates after two-stage exchange. Sixty-five cases have been treated consecutively with one-stage exchange. All patients have been followed for a period of three to six years or until death or infection recurrence. The five-year rate for infection recurrence was 16%. The five-year survival rate for recurrence of the index infection was 8%. Forty-two percent of the hips had a good or excellent PMA score, and 46% a good or excellent OH score. Routine one-stage exchange was not associated with a higher recurrence rate and a poorer hip function than previously published series of two-stage exchange. Therefore, there is little support to choose two-stage exchange as the routine treatment for management of chronically infected THR.

Impaired Thymic Output in Patients with Chronic Hepatitis C Virus Infection

DEFF Research Database (Denmark)

Hartling, Hans Jakob; Gaardbo, Julie Christine; Ronit, Andreas

2013-01-01

Altered T cell homeostasis in chronic hepatitis C virus (HCV) infection has been demonstrated. However, it is unknown if fibrosis is associated with more perturbed T cell homeostasis in chronic HCV infection. The aim of the present study was to examine and compare T cell subsets including recent...... thymic emigrants (RTE), naive, memory, senescent, apoptotic and IL-7 receptor α (CD127) expressing CD4+ and CD8+ T cells as well as telomere length and interferon-γ production in HCV-infected patients with (n=25) and without (n=26) fibrosis as well as in healthy controls (n=24). Decreased proportions...... of CD4+ and CD8+ RTE were found in HCV-infected patients, especially in HCV-infected patients with fibrosis (14.3% (9.7-23.0) and 28.8% (16.1-40.5), respectively) compared to healthy controls (24.2% (16.3-32.1), P=0.004, and 39.1% (31.6-55.0), P=0.010, respectively). Furthermore, HCV-infected patients...

Prion Infectivity in Fat of Deer with Chronic Wasting Disease▿

OpenAIRE

Race, Brent; Meade-White, Kimberly; Race, Richard; Chesebro, Bruce

2009-01-01

Chronic wasting disease (CWD) is a neurodegenerative prion disease of cervids. Some animal prion diseases, such as bovine spongiform encephalopathy, can infect humans; however, human susceptibility to CWD is unknown. In ruminants, prion infectivity is found in central nervous system and lymphoid tissues, with smaller amounts in intestine and muscle. In mice, prion infectivity was recently detected in fat. Since ruminant fat is consumed by humans and fed to animals, we determined infectivity t...

A DESCRIPTIVE STUDY OF FUNGAL INFECTIONS IN CHRONICALLY DISCHARGING EARS

Directory of Open Access Journals (Sweden)

Sujatha

2015-08-01

Full Text Available BACKGROUND : Chronic Suppurative Otitis Media (CSOM is a disease of multiple aetiology and well known for its persis tence and recurrence inspite of treatment and are the bearbug of otologist, paediatrician and general practitioner. One of the reason s for the refractoriness to treatment and chronicity is coexist ing fungal infection of the ear. OBJECTIVES: Are to find out the prevalence of fungal infections in chronic discharging ears and to identify and isolate the type of fungus prevalent in these ears . MATERIALS AND METHOD S: Tertiary care hospital level descrip tive study was conducted in 50 cases of CSOM with actively discharging ears for a period of one year starting from February 2013. For all the cases aural swabs were collected from the diseased ear and were used for direct microscopic examination in potassi um hydroxide wet mount. Ear swab was cultured on Sabouraud’s dextrose agar plate for fungal cultures. The patient characteristics were prospectively recorded and results were analysed. CONCLUSION : There is high prevalence of coexisting fungal infection in actively discharging ears of CSOM patients

SPARCHS: Symbiotic, Polymorphic, Automatic, Resilient, Clean-Slate, Host Security

Science.gov (United States)

2016-03-01

SPARCHS: SYMBIOTIC , POLYMORPHIC, AUTOMATIC, RESILIENT, CLEAN-SLATE, HOST SECURITY COLUMBIA UNIVERSITY MARCH 2016 FINAL... SYMBIOTIC , POLYMORPHIC, AUTOTOMIC, RESILIENT, CLEAN-SLATE, HOST SECURITY 5a. CONTRACT NUMBER N/A 5b. GRANT NUMBER FA8750-10-2-0253 5c. PROGRAM...17 4.2.3 SYMBIOTIC EMBEDDED MACHINES

Occult hepatitis B virus infection is not associated with disease progression of chronic hepatitis C virus infection.

Science.gov (United States)

Cho, Junhyeon; Lee, Sang Soo; Choi, Yun Suk; Jeon, Yejoo; Chung, Jung Wha; Baeg, Joo Yeong; Si, Won Keun; Jang, Eun Sun; Kim, Jin-Wook; Jeong, Sook-Hyang

2016-11-14

To clarify the prevalence of occult hepatitis B virus (HBV) infection (OBI) and the association between OBI and liver disease progression, defined as development of liver cirrhosis or hepatocellular carcinoma (HCC), worsening of Child-Pugh class, or mortality in cases of chronic hepatitis C virus (HCV) infection. This prospective cohort study enrolled 174 patients with chronic HCV infection (chronic hepatitis, n = 83; cirrhosis, n = 47; HCC, n = 44), and evaluated disease progression during a mean follow-up of 38.7 mo. OBI was defined as HBV DNA positivity in 2 or more different viral genomic regions by nested polymerase chain reaction using 4 sets of primers in the S, C, P and X open reading frame of the HBV genome. The overall OBI prevalence in chronic HCV patients at enrollment was 18.4%, with 16.9%, 25.5% and 13.6% in the chronic hepatitis C, liver cirrhosis and HCC groups, respectively ( P = 0.845). During follow-up, 52 patients showed disease progression, which was independently associated with aspartate aminotransferase > 40 IU/L, Child-Pugh score and sustained virologic response (SVR), but not with OBI positivity. In 136 patients who were not in the SVR state during the study period, OBI positivity was associated with neither disease progression, nor HCC development. The prevalence of OBI in chronic HCV patients was 18.4%, and OBI was not associated with disease progression in South Koreans.

Helicobacter pylori gene silencing in vivo demonstrates urease is essential for chronic infection.

Science.gov (United States)

Debowski, Aleksandra W; Walton, Senta M; Chua, Eng-Guan; Tay, Alfred Chin-Yen; Liao, Tingting; Lamichhane, Binit; Himbeck, Robyn; Stubbs, Keith A; Marshall, Barry J; Fulurija, Alma; Benghezal, Mohammed

2017-06-01

Helicobacter pylori infection causes chronic active gastritis that after many years of infection can develop into peptic ulceration or gastric adenocarcinoma. The bacterium is highly adapted to surviving in the gastric environment and a key adaptation is the virulence factor urease. Although widely postulated, the requirement of urease expression for persistent infection has not been elucidated experimentally as conventional urease knockout mutants are incapable of colonization. To overcome this constraint, conditional H. pylori urease mutants were constructed by adapting the tetracycline inducible expression system that enabled changing the urease phenotype of the bacteria during established infection. Through tight regulation we demonstrate that urease expression is not only required for establishing initial colonization but also for maintaining chronic infection. Furthermore, successful isolation of tet-escape mutants from a late infection time point revealed the strong selective pressure on this gastric pathogen to continuously express urease in order to maintain chronic infection. In addition to mutations in the conditional gene expression system, escape mutants were found to harbor changes in other genes including the alternative RNA polymerase sigma factor, fliA, highlighting the genetic plasticity of H. pylori to adapt to a changing niche. The tet-system described here opens up opportunities to studying genes involved in the chronic stage of H. pylori infection to gain insight into bacterial mechanisms promoting immune escape and life-long infection. Furthermore, this genetic tool also allows for a new avenue of inquiry into understanding the importance of various virulence determinants in a changing biological environment when the bacterium is put under duress.

Helicobacter pylori gene silencing in vivo demonstrates urease is essential for chronic infection.

Directory of Open Access Journals (Sweden)

Aleksandra W Debowski

2017-06-01

Full Text Available Helicobacter pylori infection causes chronic active gastritis that after many years of infection can develop into peptic ulceration or gastric adenocarcinoma. The bacterium is highly adapted to surviving in the gastric environment and a key adaptation is the virulence factor urease. Although widely postulated, the requirement of urease expression for persistent infection has not been elucidated experimentally as conventional urease knockout mutants are incapable of colonization. To overcome this constraint, conditional H. pylori urease mutants were constructed by adapting the tetracycline inducible expression system that enabled changing the urease phenotype of the bacteria during established infection. Through tight regulation we demonstrate that urease expression is not only required for establishing initial colonization but also for maintaining chronic infection. Furthermore, successful isolation of tet-escape mutants from a late infection time point revealed the strong selective pressure on this gastric pathogen to continuously express urease in order to maintain chronic infection. In addition to mutations in the conditional gene expression system, escape mutants were found to harbor changes in other genes including the alternative RNA polymerase sigma factor, fliA, highlighting the genetic plasticity of H. pylori to adapt to a changing niche. The tet-system described here opens up opportunities to studying genes involved in the chronic stage of H. pylori infection to gain insight into bacterial mechanisms promoting immune escape and life-long infection. Furthermore, this genetic tool also allows for a new avenue of inquiry into understanding the importance of various virulence determinants in a changing biological environment when the bacterium is put under duress.

Ad-hoc Symbiotic Interactive Displays through DLNA

DEFF Research Database (Denmark)

Bitsch, Jannick Elimar; Bouvin, Niels Olof

2012-01-01

The concept of symbiotic displays covers the opportunistic pairing of mobile devices with screen devices that can be discovered and controlled across a network. Mobile applications that use symbiotic displays can offer the user an improved experience, but the lack of a widely deployed infras......- tructure means that the concept has seen little use. We design and implement a solution for using DLNA playback devices as symbiotic screens. DLNA devices are not designed to support interactive content, but to share and play media content in the home. Our work includes constructing a mechanism for real...

Acute or chronic life-threatening diseases associated with Epstein-Barr virus infection.

Science.gov (United States)

Okano, Motohiko; Gross, Thomas G

2012-06-01

Infectious mononucleosis (IM) is one of the representative, usually benign, acute diseases associated with primary Epstein-Barr virus (EBV) infection. IM is generally self-limiting and is characterized mostly by transient fever, lymphadenopathy and hepatosplenomegaly. However, very rarely primary EBV infection results in severe or fatal conditions such as hemophagocytic lymphohistiocytosis together with fulminant hepatitis designated as severe or fatal IM or EBV-associated hemophagocytic lymphohistiocytosis alone. In addition, chronic EBV-associated diseases include Burkitt's lymphoma, undifferentiated nasopharyngeal carcinoma, Hodgkin lymphoma, T-cell lymphoproliferative disorder (LPD)/lymphoma, natural killer-cell LPD including leukemia or lymphoma, gastric carcinoma, pyothorax-associated lymphoma and senile B-cell LPD as well as chronic active EBV infection and LPD/lymphoma in patients with immunodeficiency. The number of chronic life-threatening diseases linked to the EBV infection is increasingly reported and many of these diseases have a poor prognosis. This review will focus on the historical, pathogenetic, diagnostic, therapeutic and prophylactic issues of EBV-associated life-threatening diseases.

The first symbiotic stars from the LAMOST survey

International Nuclear Information System (INIS)

Li, Jiao; Chen, Xue-Fei; Han, Zhan-Wen; Mikołajewska, Joanna; Luo, A-Li; Wu, Yue; Yang, Ming; Rebassa-Mansergas, Alberto; Hou, Yong-Hui; Wang, Yue-Fei; Zhang, Yong

2015-01-01

Symbiotic stars are interacting binary systems with the longest orbital periods. They are typically formed by a white dwarf and a red giant that are embedded in a nebula. These objects are natural astrophysical laboratories for studying the evolution of binaries. Current estimates of the population of symbiotic stars in the Milky Way vary from 3000 up to 400 000. However, a current census has found less than 300. The Large sky Area Multi-Object fiber Spectroscopic Telescope (LAMOST) survey can obtain hundreds of thousands of stellar spectra per year, providing a good opportunity to search for new symbiotic stars. We detect four such binaries among 4 147 802 spectra released by LAMOST, of which two are new identifications. The first is LAMOST J12280490–014825.7, considered to be an S-type halo symbiotic star. The second is LAMOST J202629.80+423652.0, a D-type symbiotic star. (paper)

The role of bacterial biofilms in chronic infections

DEFF Research Database (Denmark)

Bjarnsholt, Thomas

2013-01-01

wounds, chronic otitis media and implant- and catheter-associated infections, affect millions of people in the developed world each year and many deaths occur as a consequence. In general, bacteria have two life forms during growth and proliferation. In one form, the bacteria exist as single, independent...... cells (planktonic) whereas in the other form, bacteria are organized into sessile aggregates. The latter form is commonly referred to as the biofilm growth phenotype. Acute infections are assumed to involve planktonic bacteria, which are generally treatable with antibiotics, although successful......Acute infections caused by pathogenic bacteria have been studied extensively for well over 100 years. These infections killed millions of people in previous centuries, but they have been combated effectively by the development of modern vaccines, antibiotics and infection control measures. Most...

Chronic Mycobacterium marinum Infection Acts as a Tumor Promoter in Japanese Medaka (Oryzias latipes)

Science.gov (United States)

An accumulating body of research indicates there is an increased cancer risk associated with chronic infections. The genus Mycobacterium contains a number of species, including M tuberculosis, which mount chronic infections and have been implicated in higher cancer risk. Several ...

Near IR spectra of symbiotic stars

International Nuclear Information System (INIS)

Andrillat, Y.

1982-01-01

The author reports on recent observations from the near IR spectra of symbiotic stars. The helium and oxygen lines useful for the construction of theoretical models are identified. Observations for cool stars and novae (nebular phase) are outlined and the spectra of specific symbiotic stars between lambdalambda 8000-11000 are presented and discussed. (Auth./C.F.)

Non-symbiotic haemoglobins-What's happening beyond nitric oxide scavenging?

Science.gov (United States)

Hill, Robert D

2012-01-01

Non-symbiotic haemoglobins have been an active research topic for over 30 years, during which time a considerable portfolio of knowledge has accumulated relative to their chemical and molecular properties, and their presence and mode of induction in plants. While progress has been made towards understanding their physiological role, there remain a number of unanswered questions with respect to their biological function. This review attempts to update recent progress in this area and to introduce a hypothesis as to how non-symbiotic haemoglobins might participate in regulating hormone signal transduction. Advances have been made towards understanding the structural nuances that explain some of the differences in ligand association characteristics of class 1 and class 2 non-symbiotic haemoglobins. Non-symbiotic haemoglobins have been found to function in seed development and germination, flowering, root development and differentiation, abiotic stress responses, pathogen invasion and symbiotic bacterial associations. Microarray analyses under various stress conditions yield uneven results relative to non-symbiotic haemoglobin expression. Increasing evidence of the role of nitric oxide (NO) in hormone responses and the known involvement of non-symbiotic haemoglobins in scavenging NO provide opportunities for fruitful research, particularly at the cellular level. Circumstantial evidence suggests that non-symbiotic haemoglobins may have a critical function in the signal transduction pathways of auxin, ethylene, jasmonic acid, salicylic acid, cytokinin and abscisic acid. There is a strong need for research on haemoglobin gene expression at the cellular level relative to hormone signal transduction.

Management of Developmentally Disabled Children with Chronic Infections.

Science.gov (United States)

Andersen, Richard D.

1988-01-01

The nature of chronic infections in developmentally disabled children is reviewed, along with appropriate management strategies for care providers and implications for other children. Discussed are herpes simplex virus, cytomegalovirus, hepatitis B virus, and human immunodeficiency virus. (Author/JDD)

The symbiotic star H1-36

International Nuclear Information System (INIS)

Allen, D.A.

1983-01-01

It is suggested that H1-36 should be classified as a symbiotic star rather than a planetary nebula. Evidence of a cool giant now exists and the high-excitation emission-line spectrum resembles the spectra of many symbiotic stars. The optical spectrum, radio spectrum, high spectral index of +0.9 and computed mass-loss rate are among the features discussed

Chronic pulmonary infection with Stenotrophomonas maltophilia and lung function in patients with cystic fibrosis

DEFF Research Database (Denmark)

Dalbøge, C S; Hansen, C R; Pressler, T

2011-01-01

Background The clinical consequences of chronic Stenotrophomonas maltophilia infection in cystic fibrosis (CF) patient are still unclear. Method All patients treated in the Copenhagen CF centre (N=278) from 1 January 2008 to 31 December 2009 were included. Each patient chronically infected with S...

Determination of the term symbiotic star

International Nuclear Information System (INIS)

Boyarchuk, A.A.

1982-01-01

The author proposes the following criteria for the use of the term symbiotic star: The symbiotic stars must have a spectrum which simultaneously present the cool star features (TiO bands or G-band, etc.), and the emission lines of HeII and/or [OIII], and/or [NeIII], and lines which require even higher ionization level. He also proposes a classification of symbiotic stars according to different types of observations: according to 1) UBV photometry, 2) infrared observations, 3) radio observations, 4) absorption spectrum, 5) emission spectrum. The limted amount of ultraviolet and X-ray observations prevents any classification. The author thinks that the groups are not independent, one type showing variations belonging to another group. (Auth./C.F.)

ATM facilitates mouse gammaherpesvirus reactivation from myeloid cells during chronic infection.

Science.gov (United States)

Kulinski, Joseph M; Darrah, Eric J; Broniowska, Katarzyna A; Mboko, Wadzanai P; Mounce, Bryan C; Malherbe, Laurent P; Corbett, John A; Gauld, Stephen B; Tarakanova, Vera L

2015-09-01

Gammaherpesviruses are cancer-associated pathogens that establish life-long infection in most adults. Insufficiency of Ataxia-Telangiectasia mutated (ATM) kinase leads to a poor control of chronic gammaherpesvirus infection via an unknown mechanism that likely involves a suboptimal antiviral response. In contrast to the phenotype in the intact host, ATM facilitates gammaherpesvirus reactivation and replication in vitro. We hypothesized that ATM mediates both pro- and antiviral activities to regulate chronic gammaherpesvirus infection in an immunocompetent host. To test the proposed proviral activity of ATM in vivo, we generated mice with ATM deficiency limited to myeloid cells. Myeloid-specific ATM deficiency attenuated gammaherpesvirus infection during the establishment of viral latency. The results of our study uncover a proviral role of ATM in the context of gammaherpesvirus infection in vivo and support a model where ATM combines pro- and antiviral functions to facilitate both gammaherpesvirus-specific T cell immune response and viral reactivation in vivo. Copyright © 2015 Elsevier Inc. All rights reserved.

IL-21 augments NK effector functions in chronically HIV-infected individuals

Science.gov (United States)

Strbo, Natasa; de Armas, Lesley; Liu, Huanliang; Kolber, Michael A.; Lichtenheld, Mathias; Pahwa, Savita

2009-01-01

Objective This study addresses the interleukin (IL)-21 effects on resting peripheral blood NK cells in chronically HIV-infected individuals. Design The effects of IL-21 on perforin expression, proliferation, degranulation, IFN-γ production, cytotoxicity and induction of STAT phosphorylation in NK cells were determined in vitro. Methods Peripheral blood mononuclear cells from HIV-infected and healthy individuals were incubated in vitro for 6h, 24h or 5 days with IL-21 or IL-15. Percentages of perforin, IFN-γ, CD107a, NKG2D and STAT3-5 positive cells were determined within NK cell populations. K562 cells were used as target cells in NK cytotoxicity assay. Results Frequency of CD56dim cells in chronically HIV-infected individuals was diminished. Perforin expression in CD56dim and CD56bright was comparable in healthy and HIV-infected individuals. IL-15 up-regulated perforin expression primarily in CD56bright NK cells while IL-21 up-regulated perforin in both NK subsets. IL-21 and IL- 15 up-regulated CD107a and IFN-γ as well as NK cytotoxicity. IL-15 predominantly activated STAT5, while IL-21 activated STAT5 and STAT3. IL-15, but not IL-21 increased NK cell proliferation in uninfected and HIV-infected individuals. Conclusion IL-21 augments NK effector functions in chronically HIV-infected individuals and due to its perforin enhancing properties it has potential for immunotherapy or as a vaccine adjuvant. PMID:18670213

HAART impact on prevalence of chronic otitis media in Brazilian HIV-infected children.

Science.gov (United States)

Weber, Raimar; Pinheiro Neto, Carlos Diógenes; Miziara, Ivan Dieb; Araújo Filho, Bernardo Cunha

2006-01-01

The advent of new antiretroviral drugs such as protease inhibitors has generated sensible changes in morbity and mortality in HIV-infected patients. To evaluate the impact of Highly Active Antiretroviral Therapy (HAART) on the prevalence of chronic otitis media in HIV-infected pediatric population. We analyzed medical charts of 471 children aged zero to 12 years and 11 months with HIV infection from an Ambulatory of ENT and AIDS. Children were divided according to the age: 0 to 5 years and 11 months and 6 to 12 years and 11 months and classified as having chronic otitis media based on history, physical examination, audiologic and tympanometric data. Prevalence of chronic otitis media, as well as CD4+ lymphocyte count were compared between groups in use of HAART and the group without HAART. Out of 459 children, 65 (14.2%) had chronic otitis media. We observed that in children aged 0 to 5 years and 11 months who were taking HAART there was significant lower prevalence of chronic otitis media (p=0.02). The use of HAART was associated to higher mean CD4+ lymphocyte count (pmedia in HIV infected children, probably due to increase in mean CD4+ lymphocyte count.

Serum sphingomyelin has potential to reflect hepatic injury in chronic hepatitis B virus infection

OpenAIRE

Su-Jun Zheng; Feng Qu; Jun-Feng Li; Jing Zhao; Jing-Yun Zhang; Mei Liu; Feng Ren; Yu Chen; Jin-Lan Zhang; Zhong-Ping Duan

2015-01-01

Objective: To explore the relation between serum sphingolipids and hepatic injury in chronic HBV infection. Methods: A cohort of participants including 48 healthy persons, 103 chronic HBV-infected patients containing chronic hepatitis B (CHB) and HBV-related cirrhosis were included. High performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) was performed to detect serum sphingolipids. The serological indicators were detected and quantified. The valid liver biop...

Non-symbiotic haemoglobins—What's happening beyond nitric oxide scavenging?

Science.gov (United States)

Hill, Robert D.

2012-01-01

Background and aims Non-symbiotic haemoglobins have been an active research topic for over 30 years, during which time a considerable portfolio of knowledge has accumulated relative to their chemical and molecular properties, and their presence and mode of induction in plants. While progress has been made towards understanding their physiological role, there remain a number of unanswered questions with respect to their biological function. This review attempts to update recent progress in this area and to introduce a hypothesis as to how non-symbiotic haemoglobins might participate in regulating hormone signal transduction. Principal results Advances have been made towards understanding the structural nuances that explain some of the differences in ligand association characteristics of class 1 and class 2 non-symbiotic haemoglobins. Non-symbiotic haemoglobins have been found to function in seed development and germination, flowering, root development and differentiation, abiotic stress responses, pathogen invasion and symbiotic bacterial associations. Microarray analyses under various stress conditions yield uneven results relative to non-symbiotic haemoglobin expression. Increasing evidence of the role of nitric oxide (NO) in hormone responses and the known involvement of non-symbiotic haemoglobins in scavenging NO provide opportunities for fruitful research, particularly at the cellular level. Conclusions Circumstantial evidence suggests that non-symbiotic haemoglobins may have a critical function in the signal transduction pathways of auxin, ethylene, jasmonic acid, salicylic acid, cytokinin and abscisic acid. There is a strong need for research on haemoglobin gene expression at the cellular level relative to hormone signal transduction. PMID:22479675

Symbiotic and nonsymbiotic hemoglobin genes of Casuarina glauca

DEFF Research Database (Denmark)

Jacobsen-Lyon, K; Jensen, Erik Østergaard; Jørgensen, Jan-Elo

1995-01-01

Frankia. Both the nonsymbiotic and symbiotic genes retained their specific patterns of expression when introduced into the legume Lotus corniculatus. We interpret this finding to mean that the controls of expression of the symbiotic gene in Casuarina must be similar to the controls of expression...... of the leghemoglobin genes that operate in nodules formed during the interaction between rhizobia and legumes. Deletion analyses of the promoters of the Casuarina symbiotic genes delineated a region that contains nodulin motifs identified in legumes; this region is critical for the controlled expression...... of the Casuarina gene. The finding that the nonsymbiotic Casuarina gene is also correctly expressed in L. corniculatus suggests to us that a comparable non-symbiotic hemoglobin gene will be found in legume species. Udgivelsesdato: 1995-Feb...

Chronic hepatitis C infection is associated with insulin resistance and lipid profiles.

Science.gov (United States)

Dai, Chia-Yen; Yeh, Ming-Lun; Huang, Chung-Feng; Hou, Chen-Hsiu; Hsieh, Ming-Yen; Huang, Jee-Fu; Lin, I-Ling; Lin, Zu-Yau; Chen, Shinn-Chern; Wang, Liang-Yen; Chuang, Wan-Long; Yu, Ming-Lung; Tung, Hung-Da

2015-05-01

Chronic hepatitis C virus (HCV) infection has been suggested to be associated with non-insulin-dependent diabetes mellitus and lipid profiles. This study aimed to investigate the possible relationships of insulin resistance (IR) and lipid profiles with chronic hepatitis C (CHC) patients in Taiwan. We enrolled 160 hospital-based CHC patients with liver biopsy and the 480 controlled individuals without CHC and chronic hepatitis B from communities without known history of non-insulin-dependent diabetes mellitus. Fasting plasma glucose, total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides (TGs), alanine aminotransferase, and serum insulin levels, and homeostasis model assessment (HOMA-IR) were tested. When comparing factors between CHC patients, and sex- and age-matched controls who had no HCV infection, patients with HCV infection had a significantly higher alanine aminotransferase level, fasting plasma glucose level, insulin level, and HOMA-IR (P C and LDL-C levels (all P  2.5]), a high body mass index, TGs, and HCV RNA level are independent factors significantly associated with high HOMA-IR in multivariate logistic analyses. Chronic HCV infection was associated with metabolic characteristics including IR and lipid profile. IR was also associated with virological characteristics. © 2013 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.

Hepatitis C virus infection can mimic type 1 (antinuclear antibody positive) autoimmune chronic active hepatitis.

Science.gov (United States)

Pawlotsky, J M; Deforges, L; Bretagne, S; André, C; Métreau, J M; Thiers, V; Zafrani, E S; Goossens, M; Duval, J; Mavier, J P

1993-01-01

Hepatitis C virus (HCV) has been shown to induce anti-liver-kidney microsomal-1 (LKM1) antibody positive chronic active hepatitis, simulating type 2 autoimmune chronic active hepatitis. The cases of five patients presenting with features of type 1 (antinuclear antibody positive) autoimmune chronic active hepatitis and extrahepatic autoimmune manifestations, in whom immunosuppressive treatment had no effect on liver disease are presented. In these patients, HCV infection could be shown by the presence in serum of anti-HCV antibodies and HCV-RNA detected by polymerase chain reaction. These cases suggest the following: (a) chronic HCV infection can mimic type 1, as well as type 2, autoimmune chronic active hepatitis; (b) HCV infection might be systematically sought in patients presenting with features of type 1 autoimmune chronic active hepatitis, with special care in patients who are unresponsive to immunosuppressive treatment. Images Figure PMID:7686122

A Medicago truncatula Tobacco Retrotransposon Insertion Mutant Collection with Defects in Nodule Development and Symbiotic Nitrogen Fixation1[W][OA

Science.gov (United States)

Pislariu, Catalina I.; D. Murray, Jeremy; Wen, JiangQi; Cosson, Viviane; Muni, RajaSekhara Reddy Duvvuru; Wang, Mingyi; A. Benedito, Vagner; Andriankaja, Andry; Cheng, Xiaofei; Jerez, Ivone Torres; Mondy, Samuel; Zhang, Shulan; Taylor, Mark E.; Tadege, Million; Ratet, Pascal; Mysore, Kirankumar S.; Chen, Rujin; Udvardi, Michael K.

2012-01-01

A Tnt1-insertion mutant population of Medicago truncatula ecotype R108 was screened for defects in nodulation and symbiotic nitrogen fixation. Primary screening of 9,300 mutant lines yielded 317 lines with putative defects in nodule development and/or nitrogen fixation. Of these, 230 lines were rescreened, and 156 lines were confirmed with defective symbiotic nitrogen fixation. Mutants were sorted into six distinct phenotypic categories: 72 nonnodulating mutants (Nod−), 51 mutants with totally ineffective nodules (Nod+ Fix−), 17 mutants with partially ineffective nodules (Nod+ Fix+/−), 27 mutants defective in nodule emergence, elongation, and nitrogen fixation (Nod+/− Fix−), one mutant with delayed and reduced nodulation but effective in nitrogen fixation (dNod+/− Fix+), and 11 supernodulating mutants (Nod++Fix+/−). A total of 2,801 flanking sequence tags were generated from the 156 symbiotic mutant lines. Analysis of flanking sequence tags revealed 14 insertion alleles of the following known symbiotic genes: NODULE INCEPTION (NIN), DOESN’T MAKE INFECTIONS3 (DMI3/CCaMK), ERF REQUIRED FOR NODULATION, and SUPERNUMERARY NODULES (SUNN). In parallel, a polymerase chain reaction-based strategy was used to identify Tnt1 insertions in known symbiotic genes, which revealed 25 additional insertion alleles in the following genes: DMI1, DMI2, DMI3, NIN, NODULATION SIGNALING PATHWAY1 (NSP1), NSP2, SUNN, and SICKLE. Thirty-nine Nod− lines were also screened for arbuscular mycorrhizal symbiosis phenotypes, and 30 mutants exhibited defects in arbuscular mycorrhizal symbiosis. Morphological and developmental features of several new symbiotic mutants are reported. The collection of mutants described here is a source of novel alleles of known symbiotic genes and a resource for cloning novel symbiotic genes via Tnt1 tagging. PMID:22679222

Chronic Pseudomonas aeruginosa infection definition: EuroCareCF Working Group report

DEFF Research Database (Denmark)

Pressler, T; Bohmova, C; Conway, S

2011-01-01

are particularly challenging: the progressive nature of the disease and the wide variation in severity influence considerably the outcome of drug testing. A validated, universally accepted, and clinically useful classification of patients infected with P. aeruginosa, particularly those chronically infected...

The symbiotic star H1-36

International Nuclear Information System (INIS)

Allen, D.A.

1983-01-01

Optical and infrared spectrophotometry is presented of the high-excitation emission-line star H1-36. The presence of a variable M giant is established: H1-36 may therefore be classified as a symbiotic star. The observations are interpreted in terms of the usual binary model for symbiotic stars, namely that an unseen star is heated by accretion of gas from its companion M giant. (author)

Rare Freshwater Ciliate Paramecium chlorelligerum Kahl, 1935 and Its Macronuclear Symbiotic Bacterium "Candidatus Holospora parva".

Science.gov (United States)

Lanzoni, Olivia; Fokin, Sergei I; Lebedeva, Natalia; Migunova, Alexandra; Petroni, Giulio; Potekhin, Alexey

2016-01-01

Ciliated protists often form symbioses with many diverse microorganisms. In particular, symbiotic associations between ciliates and green algae, as well as between ciliates and intracellular bacteria, are rather wide-spread in nature. In this study, we describe the complex symbiotic system between a very rare ciliate, Paramecium chlorelligerum, unicellular algae inhabiting its cytoplasm, and novel bacteria colonizing the host macronucleus. Paramecium chlorelligerum, previously found only twice in Germany, was retrieved from a novel location in vicinity of St. Petersburg in Russia. Species identification was based on both classical morphological methods and analysis of the small subunit rDNA. Numerous algae occupying the cytoplasm of this ciliate were identified with ultrastructural and molecular methods as representatives of the Meyerella genus, which before was not considered among symbiotic algae. In the same locality at least fifteen other species of "green" ciliates were found, thus it is indeed a biodiversity hot-spot for such protists. A novel species of bacterial symbionts living in the macronucleus of Paramecium chlorelligerum cells was morphologically and ultrastructurally investigated in detail with the description of its life cycle and infection capabilities. The new endosymbiont was molecularly characterized following the full-cycle rRNA approach. Furthermore, phylogenetic analysis confirmed that the novel bacterium is a member of Holospora genus branching basally but sharing all characteristics of the genus except inducing connecting piece formation during the infected host nucleus division. We propose the name "Candidatus Holospora parva" for this newly described species. The described complex system raises new questions on how these microorganisms evolve and interact in symbiosis.

Rare Freshwater Ciliate Paramecium chlorelligerum Kahl, 1935 and Its Macronuclear Symbiotic Bacterium "Candidatus Holospora parva".

Directory of Open Access Journals (Sweden)

Olivia Lanzoni

Full Text Available Ciliated protists often form symbioses with many diverse microorganisms. In particular, symbiotic associations between ciliates and green algae, as well as between ciliates and intracellular bacteria, are rather wide-spread in nature. In this study, we describe the complex symbiotic system between a very rare ciliate, Paramecium chlorelligerum, unicellular algae inhabiting its cytoplasm, and novel bacteria colonizing the host macronucleus. Paramecium chlorelligerum, previously found only twice in Germany, was retrieved from a novel location in vicinity of St. Petersburg in Russia. Species identification was based on both classical morphological methods and analysis of the small subunit rDNA. Numerous algae occupying the cytoplasm of this ciliate were identified with ultrastructural and molecular methods as representatives of the Meyerella genus, which before was not considered among symbiotic algae. In the same locality at least fifteen other species of "green" ciliates were found, thus it is indeed a biodiversity hot-spot for such protists. A novel species of bacterial symbionts living in the macronucleus of Paramecium chlorelligerum cells was morphologically and ultrastructurally investigated in detail with the description of its life cycle and infection capabilities. The new endosymbiont was molecularly characterized following the full-cycle rRNA approach. Furthermore, phylogenetic analysis confirmed that the novel bacterium is a member of Holospora genus branching basally but sharing all characteristics of the genus except inducing connecting piece formation during the infected host nucleus division. We propose the name "Candidatus Holospora parva" for this newly described species. The described complex system raises new questions on how these microorganisms evolve and interact in symbiosis.

Adaptive evolution of the symbiotic gene NORK is not correlated with shifts of rhizobial specificity in the genus Medicago

NARCIS (Netherlands)

Mita, De S.; Santoni, S.; Ronfort, J.; Bataillon, T.

2007-01-01

The NODULATION RECEPTOR KINASE (NORK) gene encodes a Leucine-Rich Repeat (LRR)-containing receptor-like protein and controls the infection by symbiotic rhizobia and endomycorrhizal fungi in Legumes. The occurrence of numerous amino acid changes driven by directional selection has been reported in

Clinical and epidemiological features of patients with chronic hepatitis C co-infected with HIV

Directory of Open Access Journals (Sweden)

Braga Eduardo Lorens

Full Text Available Co-infection with hepatitis C virus (HCV and human immunodeficiency virus (HIV is increasingly common and affects the clinical course of chronic hepatitis C. Highly active antiretroviral therapy has improved the life expectancy of HIV infected patients, but, by extending survival, it permits the development of HCV cirrhosis. This study tried to evaluate clinical and epidemiological features of patients with chronic hepatitis C co-infected with HIV. We evaluated 134 HCV-infected patients: i group A - 65 co-infected HCV/HIV patients, ii group B - 69 mono-infected HCV patients. The impact of HIV infection on HCV liver disease was analyzed using Child's score, ultrasound findings and liver histology. Patients were subjected to HCV genotyping and anti-HBs dosage. Patients mean age was 42.4 years (±9.1 and 97 (72.4% were males. Injected drug use and homo/bisexual practice were more frequently encountered in the co-infected group: 68.3% and 78.0%, respectively. Antibodies against hepatitis B virus (anti-HBs were found in only 38.1% of the patients (66.7% group A x 33.3% group B. Ten out of 14 individuals (71.4% who had liver disease (Child B or C and 25 out of 34 (73.5% who showed ultrasound evidence of chronic liver disease were in the co-infection group. HCV genotype-2/3 was more frequently encountered in co-infected patients (36.9% group A vs. 21.8% group B. Conclusions: a HIV infection seems to adversely affect the clinical course of chronic hepatitis C, b injected drug use, bi/homosexual practice and genotype-2/3 were more frequently encountered in co-infected patients, c immunization against HBV should be encouraged in these patients.

Effects of symbiotic bacteria on chemical sensitivity of Daphnia magna.

Science.gov (United States)

Manakul, Patcharaporn; Peerakietkhajorn, Saranya; Matsuura, Tomoaki; Kato, Yasuhiko; Watanabe, Hajime

2017-07-01

The crustacean zooplankton Daphnia magna has been widely used for chemical toxicity tests. Although abiotic factors have been well documented in ecotoxicological test protocols, biotic factors that may affect the sensitivity to chemical compounds remain limited. Recently, we identified symbiotic bacteria that are critical for the growth and reproduction of D. magna. The presence of symbiotic bacteria on Daphnia raised the question as to whether these bacteria have a positive or negative effect on toxicity tests. In order to evaluate the effects of symbiotic bacteria on toxicity tests, bacteria-free Daphnia were prepared, and their chemical sensitivities were compared with that of Daphnia with symbiotic bacteria based on an acute immobilization test. The Daphnia with symbiotic bacteria showed higher chemical resistance to nonylphenol, fenoxycarb, and pentachlorophenol than bacteria-free Daphnia. These results suggested potential roles of symbiotic bacteria in the chemical resistance of its host Daphnia. Copyright © 2017 Elsevier Ltd. All rights reserved.

Persistence of Tetracapsuloides bryosalmonae (Myxozoa) in chronically infected brown trout Salmo trutta.

Science.gov (United States)

Abd-Elfattah, Ahmed; Kumar, Gokhlesh; Soliman, Hatem; El-Matbouli, Mansour

2014-08-21

Proliferative kidney disease (PKD) is a widespread disease of farmed and wild salmonid populations in Europe and North America, caused by the myxozoan parasite Tetracapsuloides bryosalmonae. Limited studies have been performed on the epidemiological role in spread of the disease played by fish that survive infection with T. bryosalmonae. The aim of the present study was to evaluate the persistence of T. bryosalmonae developmental stages in chronically infected brown trout Salmo trutta up to 2 yr after initial exposure to laboratory-infected colonies of the parasite's alternate host, the bryozoan Fredericella sultana. Kidney, liver, spleen, intestine, brain, gills and blood were sampled 24, 52, 78 and 104 wk post-exposure (wpe) and tested for T. bryosalmonae by PCR and immunohistochemistry (IHC). Cohabitation trials with specific pathogen free (SPF) F. sultana colonies were conducted to test the viability of T. bryosalmonae. PCR detected T. bryosalmonae DNA in all tissue samples collected at the 4 time points. Developmental stages of T. bryosalmonae were demonstrated by IHC in most samples at the 4 time points. Cohabitation of SPF F. sultana with chronically infected brown trout resulted in successful transmission of T. bryosalmonae to the bryozoan. This study verified the persistence of T. bryosalmonae in chronically infected brown trout and their ability to infect the bryozoan F. sultana up to 104 wpe.

Hepatitis C virus quasispecies and pseudotype analysis from acute infection to chronicity in HIV-1 co-infected individuals.

Science.gov (United States)

Ferns, R Bridget; Tarr, Alexander W; Hue, Stephane; Urbanowicz, Richard A; McClure, C Patrick; Gilson, Richard; Ball, Jonathan K; Nastouli, Eleni; Garson, Jeremy A; Pillay, Deenan

2016-05-01

HIV-1 infected patients who acquire HCV infection have higher rates of chronicity and liver disease progression than patients with HCV mono-infection. Understanding early events in this pathogenic process is important. We applied single genome sequencing of the E1 to NS3 regions and viral pseudotype neutralization assays to explore the consequences of viral quasispecies evolution from pre-seroconversion to chronicity in four co-infected individuals (mean follow up 566 days). We observed that one to three founder viruses were transmitted. Relatively low viral sequence diversity, possibly related to an impaired immune response, due to HIV infection was observed in three patients. However, the fourth patient, after an early purifying selection displayed increasing E2 sequence evolution, possibly related to being on suppressive antiretroviral therapy. Viral pseudotypes generated from HCV variants showed relative resistance to neutralization by autologous plasma but not to plasma collected from later time points, confirming ongoing virus escape from antibody neutralization. Copyright © 2016 Elsevier Inc. All rights reserved.

Interaction of TLR-IFN and HLA polymorphisms on susceptibility of chronic HBV infection in Southwest Han Chinese.

Science.gov (United States)

He, Dengming; Tao, Shiqi; Guo, Shimin; Li, Maoshi; Wu, Junqiu; Huang, Hongfei; Guo, Xinwu; Yan, Guohua; Zhu, Peng; Wang, Yuming

2015-08-01

The toll-like receptor-interferon (TLR-IFN) signalling pathway plays a crucial role in HBV infection. Human leucocyte antigen (HLA) polymorphisms are associated with chronic HBV infection by genome wide association study (GWAS). We aimed to explore interaction between TLR-IFN and HLA gene polymorphisms in susceptibility of chronic HBV infection. In the Chinese Southwest Han population, 1191 chronic HBV infection patients and 273 HBV clearance were selected. A total of 39 single nucleotide polymorphism loci in 23 genes of the TLR-IFN pathway and four HLA polymorphism loci associated with chronic HBV infection identified by GWAS were selected for genotyping. SNPStats, QVALUE, and multifactor dimensionality reduction were used for statistical analysis. A significant association was seen in several of the TLR-IFN pathway genes, TLR9 rs352140 (OR = 0.70, P = 0.0088), IL1B rs16944 (OR = 0.67, P = 0.016), IL12B rs3212227 (OR = 1.38, P = 0.021), IFNGR1 rs3799488 (OR = 1.48, P = 0.0048), IFNGR2 rs1059293 (OR = 0.27, P = 0.011), MX1 rs467960 (OR = 0.68, P = 0.022), as well as four loci in HLA, rs3077 (OR = 0.55, P rs16944 (0.13%), rs1143623 and rs6613 (0.10%). The combination of rs9277535 in HLA and rs16944 in IL1B was the best model to predict chronic HBV infection (testing accuracy = 0.6040, P = 0.0010, cross-validation consistency = 10/10). TLR-IFN pathway gene polymorphisms are associated with chronic HBV infection. Interactions with polymorphisms in these genes may be one mechanism by which HLA polymorphisms influence susceptibility to chronic HBV infection, as specific single nucleotide polymorphism combinations are highly predictive of chronic HBV infection. © 2014 The Authors. Liver International Published by John Wiley & Sons Ltd.

Mortality in patients with chronic and cleared hepatitis C viral infection: a nationwide cohort study

DEFF Research Database (Denmark)

Omland, Lars Haukali; Krarup, Henrik; Jepsen, Peter

2010-01-01

It is unknown whether mortality differs between patients with chronic hepatitis C virus (HCV) replication and those who cleared the virus after infection. We examined the impact of chronic HCV replication on mortality among Danish patients testing positive for HCV antibodies.......It is unknown whether mortality differs between patients with chronic hepatitis C virus (HCV) replication and those who cleared the virus after infection. We examined the impact of chronic HCV replication on mortality among Danish patients testing positive for HCV antibodies....

Significance of occult hbv infection in patients with chronic hepatitis c

International Nuclear Information System (INIS)

Anwar, W.; Sarwar, M.; Saif, M.; Hussain, A.B.; Tariq, W.Z.

2006-01-01

Objective: To determine the frequency of occurrence of occult Hepatitis B infection in chronic hepatitis C patients and its impact (if any) on the effectivity of standard chronic hepatitis C treatment. Design: Quasi-experimental study. Place and Duration of Study: The study was conducted at the Department of Medicine, Military Hospital, Rawalpindi, and Virology Department, Armed Forces Institute of Pathology, Rawalpindi, for a period of nine months from January 2003 to September 2003. Patients and Methods: This study was conducted on 30 HBsAg negative patients with chronic hepatitis C liver disease who were receiving combination therapy with interferon and ribavirin. Occult hepatitis B infection was assessed by carrying out HBV DNA by polymerase chain reaction (PCR) in the sera of these patients. Markers of previous hepatitis B infection Le; anti-HBs and total anti-HBc antibodies were also tested. Response to treatment for hepatitis C (with interferon and ribavirin) was assessed at the end of six months of therapy by measuring ALT levels and HCV RNA by PCR in the serum. Results: In our study only one patient (3.33%) was found to be harbouring HBV DNA in the serum detectable by PCR, with markers of previous HBV infection (both anti HBc antibodies and anti HBs antibodies were positive). A total 14 patients (46.67%) had markers of previous HBV infection, while 16 patients (53.33%) had no such sero markers. Twenty five out of 30 patients (83.33%) responded to treatment and 5 (16.66%) turned out to be non-responders. The single case of occult hepatitis B detected in this study responded to hepatitis C treatment. Conclusion: Occult hepatitis B is not a common occurrence in chronic hepatitis C patients and it did not alter the outcome of treatment for hepatitis C in our study. (author)

The role of environmental tobacco exposure and Helicobacter pylori infection in the risk of chronic tonsillitis in children

Directory of Open Access Journals (Sweden)

Chen Li’e

Full Text Available ABSTRACT CONTEXT AND OBJECTIVE: Helicobacter pylori (H. pylori is a chronic infectious pathogen with high prevalence. This study investigated the interaction between environmental tobacco exposure and H. pylori infection on the incidence of chronic tonsillitis in Chinese children. DESIGN AND SETTING: Cross-sectional study performed in an outpatient clinic in China. METHODS: Pediatric patients with chronic tonsillitis were enrolled. H. pylori infection was determined according to the presence of H. pylori CagA IgG antibodies. Serum cotinine levels and environmental tobacco smoke (ETS exposure were determined for all participants. RESULTS: There was no significant difference in H. pylori infection between the children with chronic tonsillitis and children free of disease, but there was a significant difference in ETS between the two groups (P = 0.011. We next studied the association between ETS and chronic tonsillitis based on H. pylori infection status. In the patients with H. pylori infection, there was a significant difference in ETS distribution between the chronic tonsillitis and control groups (P = 0.022. Taking the participants without ETS as the reference, multivariate logistic regression analysis showed that those with high ETS had higher susceptibility to chronic tonsillitis (adjusted OR = 2.33; 95% CI: 1.67-3.25; adjusted P < 0.001. However, among those without H. pylori infection, ETS did not predispose towards chronic tonsillitis. CONCLUSION: Our findings suggest that tobacco exposure should be a putative mediator risk factor to chronic tonsillitis among children with H. pylori infection.

The Risk of Chronic Gastrointestinal Disorders Following Acute Infection with Intestinal Parasites

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Jason Blitz

2018-01-01

Full Text Available Background: Infectious gastroenteritis (IGE is caused by numerous bacterial, viral, and parasitic pathogens. A history of IGE has been shown in previous studies to increase the risk of developing chronic gastrointestinal disorders and other chronic conditions. As bacteria and viruses represent the majority of pathogen-specific causes of IGE, post-infectious studies have primarily focused on these organisms. The objective of this study was to investigate an association between a history of parasite-associated IGE and the subsequent development of chronic post-infectious gastrointestinal and non-gastrointestinal disorders in a military population.Methods: International Classification of Diseases, 9th Revision Clinical Modification (ICD-9-CM diagnostic coding data for primary exposures and outcomes were obtained for a retrospective cohort study of active component military personnel from 1998 to 2013. Exposed subjects consisted of individuals with documented infection with one of ten parasitic pathogens. Unexposed subjects were matched to exposed subjects on demographic and operational deployment history parameters. Adjusted odds ratios (aORs were estimated using logistic regression for several chronic disorders previously shown to be associated with a history of IGE.Results: A total of 896 subjects with a parasitic exposure were matched to 3681 unexposed subjects for multivariate regression analysis. Individuals infected with Balantidium coli, Ascaris lumbricoides, Strongyloides stercoralis, Necator americanus/Ancylostoma duodenale, and Taenia spp. had higher aOR for development of several chronic gastrointestinal disorders when compared with unexposed subjects after controlling for various covariates.Conclusion: We found that parasite-associated enteric infection increases the risk of development of post-infectious chronic gastrointestinal disorders in a military population. These results require confirmation in similar populations and in the

Outbursts of symbiotic novae

International Nuclear Information System (INIS)

Kenyon, S.J.; Truran, J.W.

1983-01-01

We discuss possible conditions under which thermonuclear burning episodes in the hydrogen-rich envelopes of accreting white dwarfs give rise to outbursts similar in nature to those observed in the symbiotic stars AG Peg, RT Ser, RR Tel, AS 239, V1016 Cyg, V1329 Cyg, and HM Sge. In principle, thermonuclear runaways involving low-luminosity white dwarfs accreting matter at low rates produce configurations that evolve into A--F supergiants at maximum visual light and which resemble the outbursts of RR Tel, RT Ser, and AG peg. Very weak, nondegenerage hydrogen shell flashes on white dwarfs accreting matter at high rates (M> or approx. =10 -8 M/sub sun/ yr -1 ) do not produce cool supergiants at maximum, and may explain the outbursts in V1016 Cyg, V1329 Cyg, and HM Sge. The low accretion rates demanded for systems developing strong hydrogen shell flashes on low-luminsoity white dwarfs are not compatible with observations of ''normal'' quiescent symbiotic stars. The extremely slow outbursts of symbiotic novae appear to be typical of accreting white dwarfs in wide binaries, which suggests that the outbursts of classical novae may be accelerated by the interaction of the expanding white dwarf envelope with its close binary companion

Symbiotic Origin of Aging.

Science.gov (United States)

Greenberg, Edward F; Vatolin, Sergei

2018-06-01

Normally aging cells are characterized by an unbalanced mitochondrial dynamic skewed toward punctate mitochondria. Genetic and pharmacological manipulation of mitochondrial fission/fusion cycles can contribute to both accelerated and decelerated cellular or organismal aging. In this work, we connect these experimental data with the symbiotic theory of mitochondrial origin to generate new insight into the evolutionary origin of aging. Mitochondria originated from autotrophic α-proteobacteria during an ancient endosymbiotic event early in eukaryote evolution. To expand beyond individual host cells, dividing α-proteobacteria initiated host cell lysis; apoptosis is a product of this original symbiont cell lytic exit program. Over the course of evolution, the host eukaryotic cell attenuated the harmful effect of symbiotic proto-mitochondria, and modern mitochondria are now functionally interdependent with eukaryotic cells; they retain their own circular genomes and independent replication timing. In nondividing differentiated or multipotent eukaryotic cells, intracellular mitochondria undergo repeated fission/fusion cycles, favoring fission as organisms age. The discordance between cellular quiescence and mitochondrial proliferation generates intracellular stress, eventually leading to a gradual decline in host cell performance and age-related pathology. Hence, aging evolved from a conflict between maintenance of a quiescent, nonproliferative state and the evolutionarily conserved propagation program driving the life cycle of former symbiotic organisms: mitochondria.

Intracellular pH and its response to CO2-driven seawater acidification in symbiotic versus non-symbiotic coral cells.

Science.gov (United States)

Gibbin, Emma M; Putnam, Hollie M; Davy, Simon K; Gates, Ruth D

2014-06-01

Regulating intracellular pH (pHi) is critical for optimising the metabolic activity of corals, yet the mechanisms involved in pH regulation and the buffering capacity within coral cells are not well understood. Our study investigated how the presence of symbiotic dinoflagellates affects the response of pHi to PCO2-driven seawater acidification in cells isolated from Pocillopora damicornis. Using the fluorescent dye BCECF-AM, in conjunction with confocal microscopy, we simultaneously characterised the pHi response in host coral cells and their dinoflagellate symbionts, in symbiotic and non-symbiotic states under saturating light, with and without the photosynthetic inhibitor DCMU. Each treatment was run under control (pH 7.8) and CO2-acidified seawater conditions (decreasing pH from 7.8 to 6.8). After 105 min of CO2 addition, by which time the external pH (pHe) had declined to 6.8, the dinoflagellate symbionts had increased their pHi by 0.5 pH units above control levels when in the absence of DCMU. In contrast, in both symbiotic and non-symbiotic host coral cells, 15 min of CO2 addition (0.2 pH unit drop in pHe) led to cytoplasmic acidosis equivalent to 0.3-0.4 pH units irrespective of whether DCMU was present. Despite further seawater acidification over the duration of the experiment, the pHi of non-symbiotic coral cells did not change, though in host cells containing a symbiont cell the pHi recovered to control levels when photsynthesis was not inhibited. This recovery was negated when cells were incubated with DCMU. Our results reveal that photosynthetic activity of the endosymbiont is tightly coupled with the ability of the host cell to recover from cellular acidosis after exposure to high CO2/low pH. © 2014. Published by The Company of Biologists Ltd.

Establishment of Chronic Infection: Brucella's Stealth Strategy

Science.gov (United States)

Ahmed, Waqas; Zheng, Ke; Liu, Zheng-Fei

2016-01-01

Brucella is a facultative intracellular pathogen that causes zoonotic infection known as brucellosis which results in abortion and infertility in natural host. Humans, especially in low income countries, can acquire infection by direct contact with infected animal or by consumption of animal products and show high morbidity, severe economic losses and public health problems. However for survival, host cells develop complex immune mechanisms to defeat and battle against attacking pathogens and maintain a balance between host resistance and Brucella virulence. On the other hand as a successful intracellular pathogen, Brucella has evolved multiple strategies to evade immune response mechanisms to establish persistent infection and replication within host. In this review, we mainly summarize the “Stealth” strategies employed by Brucella to modulate innate and the adaptive immune systems, autophagy, apoptosis and possible role of small noncoding RNA in the establishment of chronic infection. The purpose of this review is to give an overview for recent understanding how this pathogen evades immune response mechanisms of host, which will facilitate to understanding the pathogenesis of brucellosis and the development of novel, more effective therapeutic approaches to treat brucellosis. PMID:27014640

Symbiotic binaries

International Nuclear Information System (INIS)

Mikolajewska, J.; Iijima, T.

1988-01-01

The symbiotic star BF Cyg shows periodic variations in its spectrum. [O3] line intensity changes in antiphase with the blue continuum, H-Balmer and He1 emission line intensity. These variations are interpreted in terms of a hot star moving on an eccentric orbit and ionizing a part of an M-type giant wind. 20 refs., 2 figs., 1 tab. (author)

Rare Freshwater Ciliate Paramecium chlorelligerum Kahl, 1935 and Its Macronuclear Symbiotic Bacterium “Candidatus Holospora parva”

Science.gov (United States)

Lebedeva, Natalia; Migunova, Alexandra; Petroni, Giulio

2016-01-01

Ciliated protists often form symbioses with many diverse microorganisms. In particular, symbiotic associations between ciliates and green algae, as well as between ciliates and intracellular bacteria, are rather wide-spread in nature. In this study, we describe the complex symbiotic system between a very rare ciliate, Paramecium chlorelligerum, unicellular algae inhabiting its cytoplasm, and novel bacteria colonizing the host macronucleus. Paramecium chlorelligerum, previously found only twice in Germany, was retrieved from a novel location in vicinity of St. Petersburg in Russia. Species identification was based on both classical morphological methods and analysis of the small subunit rDNA. Numerous algae occupying the cytoplasm of this ciliate were identified with ultrastructural and molecular methods as representatives of the Meyerella genus, which before was not considered among symbiotic algae. In the same locality at least fifteen other species of “green” ciliates were found, thus it is indeed a biodiversity hot-spot for such protists. A novel species of bacterial symbionts living in the macronucleus of Paramecium chlorelligerum cells was morphologically and ultrastructurally investigated in detail with the description of its life cycle and infection capabilities. The new endosymbiont was molecularly characterized following the full-cycle rRNA approach. Furthermore, phylogenetic analysis confirmed that the novel bacterium is a member of Holospora genus branching basally but sharing all characteristics of the genus except inducing connecting piece formation during the infected host nucleus division. We propose the name “Candidatus Holospora parva” for this newly described species. The described complex system raises new questions on how these microorganisms evolve and interact in symbiosis. PMID:27992463

Effect of neem cake/fertilizers on symbiotic and non-symbiotic N2 fixing bacteria

International Nuclear Information System (INIS)

Akhtar, S.; Solangi, A.H.; Gilani, G.; Pirzada, M.H.

2002-01-01

Neem cake amendment in soil at 1.3% no adverse effect on the population of four symbiotic Rhizobium species viz., japonicum, R. leguminosarum, R. Phaseoli and R. Fredii and three non-symbiotic free living nitrogen fixers bacteria viz., Pseudomonas diazotrophicus, Klebsiella planticola and Enterobacter cloacae. Neem cake extracted with n-hexane stimulated the growth of Rhizobium species in vitro, whereas Neem cake expeller extracted neither inhibited nor stimulated the growth of Rhizobium species except for R. Fredii, whose was slightly retarded. The fertilizers (urea, NPK and DAP) had no adverse effect on these bacteria even at the dosage ten times higher the recommended dose. (author)

Recent photometry of selected symbiotic stars

Science.gov (United States)

Vrašťák, M.

2018-04-01

A new multicolour (BVRcIc) photometric observations of symbiotic stars UV Aur, YY Her, V443 Her, V1016 Cyg, PU Vul, V407 Cyg, V471 Per and suspected symbiotic stars ZZ CMi, NQ Gem, V934 Her, V335 Vul, V627 Cas is presented. The data were obtained from 2016 October to 2018 January by the metod of classical CCD photometry. The monitoring program is still running, so on this paper partial light curves are presented.

Insulin resistance and liver steatosis in chronic hepatitis C infection genotype 3.

Science.gov (United States)

Abenavoli, Ludovico; Masarone, Mario; Peta, Valentina; Milic, Natasa; Kobyliak, Nazarii; Rouabhia, Samir; Persico, Marcello

2014-11-07

Hepatitis C virus (HCV) infection is a common chronic liver disease worldwide. Non-alcoholic fatty liver disease and insulin resistance (IR) are the major determinants of fibrosis progression and response to antiviral therapy. The pathogenetic link between IR and chronic HCV infection is complex, and is associated with HCV genotype. Liver steatosis is the most common in the patients infected with genotype 3 virus, possibly due to direct effects of genotype 3 viral proteins. To the contrary, hepatic steatosis in the patients infected with other genotypes is thought to be mostly due to the changes in host metabolism, involving IR. In HCV genotype 3, liver steatosis correlates with viral load, reverts after reaching the sustained virologic response and reoccurs in the relapsers. A therapeutic strategy to improve IR and liver steatosis and subsequently the response to antiviral treatment in these patients is warranted.

Symbiotic and VV Cephei stars in the Small Magellanic Cloud

International Nuclear Information System (INIS)

Walker, A.R.

1983-01-01

Three symbiotic stars, including a carbon symbiotic star, are identified in the Small Magellanic Cloud, thus two out of five known symbiotic stars in the Magellanic Clouds have C rather than M components, compared to our own Galaxy where the proportion is much lower. This supports the assertion that the symbiotic phenomenon follows the higher C:M star ratio in the Magellanic Clouds and is not a property of M binaries alone. Two other emission-line stars are discussed; one is the only known VV Cephei star in the SMC while the second is a composite Be + K supergiant system. (author)

Hepatitis E virus genotype three infection of human liver chimeric mice as a model for chronic HEV infection

NARCIS (Netherlands)

M.D.B. van de Garde (Martijn D.B.); S.D. Pas (Suzan); G. van der Net (Guido); R.A. de Man (Robert); A.D.M.E. Osterhaus (Albert); B.L. Haagmans (Bart); A. Boonstra (Andre); T. Vanwolleghem (Thomas)

2016-01-01

textabstractGenotype (gt) 3 hepatitis E virus (HEV) infections are emerging in Western countries. Immunosuppressed patients are at risk of chronic HEV infection and progressive liver damage, but no adequate model system currently mimics this disease course. Here we explore the possibilities of in

Chronic cutaneous ulcers secondary to Haemophilus ducreyi infection.

Science.gov (United States)

Peel, Trisha N; Bhatti, Deepak; De Boer, Jim C; Stratov, Ivan; Spelman, Denis W

2010-03-15

Haemophilus ducreyi is a well recognised causative agent of genital ulcers and chancroid. We report two unusual cases of non-sexually transmitted H. ducreyi infection leading to chronic lower limb ulcers. Both patients were Australian expatriates visiting Australia from the Pacific Islands--one from Papua New Guinea and the other from Vanuatu.

Relation between Helicobacter pylori infection and chronic urticaria

Directory of Open Access Journals (Sweden)

Adianez Sugrañes-Montalván

2017-12-01

Conclusions: In the present study, the relationship between chronic urticaria and Helicobacter pylori infection was demonstrated. Apparently, the eradicating treatment for Helicobacter pylori was effective as the patients had no symptoms after treatment. Specific immunoglobulin G and Urease Test together constitute a suitable diagnostic module for the diagnosis of Helicobacter pylori conditions.

Phylogeny of Symbiotic Genes and the Symbiotic Properties of Rhizobia Specific to Astragalus glycyphyllos L.

Science.gov (United States)

Gnat, Sebastian; Małek, Wanda; Oleńska, Ewa; Wdowiak-Wróbel, Sylwia; Kalita, Michał; Łotocka, Barbara; Wójcik, Magdalena

2015-01-01

The phylogeny of symbiotic genes of Astragalus glycyphyllos L. (liquorice milkvetch) nodule isolates was studied by comparative sequence analysis of nodA, nodC, nodH and nifH loci. In all these genes phylograms, liquorice milkvetch rhizobia (closely related to bacteria of three species, i.e. Mesorhizobium amorphae, Mesorhizobium septentrionale and Mesorhizobium ciceri) formed one clearly separate cluster suggesting the horizontal transfer of symbiotic genes from a single ancestor to the bacteria being studied. The high sequence similarity of the symbiotic genes of A. glycyphyllos rhizobia (99-100% in the case of nodAC and nifH genes, and 98-99% in the case of nodH one) points to the relatively recent (in evolutionary scale) lateral transfer of these genes. In the nodACH and nifH phylograms, A. glycyphyllos nodule isolates were grouped together with the genus Mesorhizobium species in one monophyletic clade, close to M. ciceri, Mesorhizobium opportunistum and Mesorhizobium australicum symbiovar biserrulae bacteria, which correlates with the close relationship of these rhizobia host plants. Plant tests revealed the narrow host range of A. glycyphyllos rhizobia. They formed effective symbiotic interactions with their native host (A. glycyphyllos) and Amorpha fruticosa but not with 11 other fabacean species. The nodules induced on A. glycyphyllos roots were indeterminate with apical, persistent meristem, an age gradient of nodule tissues and cortical vascular bundles. To reflect the symbiosis-adaptive phenotype of rhizobia, specific for A. glycyphyllos, we propose for these bacteria the new symbiovar "glycyphyllae", based on nodA and nodC genes sequences.

Evolutionary Instability of Symbiotic Function in Bradyrhizobium japonicum

Science.gov (United States)

Sachs, Joel L.; Russell, James E.; Hollowell, Amanda C.

2011-01-01

Bacterial mutualists are often acquired from the environment by eukaryotic hosts. However, both theory and empirical work suggest that this bacterial lifestyle is evolutionarily unstable. Bacterial evolution outside of the host is predicted to favor traits that promote an independent lifestyle in the environment at a cost to symbiotic function. Consistent with these predictions, environmentally-acquired bacterial mutualists often lose symbiotic function over evolutionary time. Here, we investigate the evolutionary erosion of symbiotic traits in Bradyrhizobium japonicum, a nodulating root symbiont of legumes. Building on a previous published phylogeny we infer loss events of nodulation capability in a natural population of Bradyrhizobium, potentially driven by mutation or deletion of symbiosis loci. Subsequently, we experimentally evolved representative strains from the symbiont population under host-free in vitro conditions to examine potential drivers of these loss events. Among Bradyrhizobium genotypes that evolved significant increases in fitness in vitro, two exhibited reduced symbiotic quality, but no experimentally evolved strain lost nodulation capability or evolved any fixed changes at six sequenced loci. Our results are consistent with trade-offs between symbiotic quality and fitness in a host free environment. However, the drivers of loss-of-nodulation events in natural Bradyrhizobium populations remain unknown. PMID:22073160

[Progress of heterotrophic studies on symbiotic corals].

Science.gov (United States)

Yang, Yang-Chu-Qiao; Hong, Wen Ting; Wang, Shu Hong

2017-12-01

Heterotrophy of zooxanthellae symbiotic corals refers to the nutrition directly coming from food absorption, not the nutrition obtained from photosynthesis. Most ex situ propagation of symbiotic corals focused on the effects of irradiation, flow rate and water quality on corals, few of them involved in the demand and supply of coral heterotrophic nutrition. This paper reviewed the significance of heterotrophic nutrient supply to symbiotic corals from the sources of coral heterotrophic nutrition, the factors affecting the supply of coral heterotrophic nutrient, and the methods of how to study the coral heterotrophy. In general, the research of coral heterotrophy is just at the beginning stage, and future studies should focus on the inherent mechanism of coral feeding selection and developing more effective research methods.

Chronic schistosomiasis during pregnancy epigenetically reprograms T-cell differentiation in offspring of infected mothers.

Science.gov (United States)

Klar, Kathrin; Perchermeier, Sophie; Bhattacharjee, Sonakshi; Harb, Hani; Adler, Thure; Istvanffy, Rouzanna; Loffredo-Verde, Eva; Oostendorp, Robert A; Renz, Harald; Prazeres da Costa, Clarissa

2017-05-01

Schistosomiasis is a nontransplacental helminth infection. Chronic infection during pregnancy suppresses allergic airway responses in offspring. We addressed the question whether in utero exposure to chronic schistosome infection (Reg phase) in mice affects B-cell and T-cell development. Therefore, we focused our analyses on T-cell differentiation capacity induced by epigenetic changes in promoter regions of signature cytokines in offspring. Here, we show that naïve T cells from offspring of schistosome infected female mice had a strong capacity to differentiate into T H 1 cells, whereas T H 2 differentiation was impaired. In accordance, reduced levels of histone acetylation of the IL-4 promoter regions were observed in naïve T cells. To conclude, our mouse model revealed distinct epigenetic changes within the naïve T-cell compartment affecting T H 2 and T H 1 cell differentiation in offspring of mothers with chronic helminth infection. These findings could eventually help understand how helminths alter T-cell driven immune responses induced by allergens, bacterial or viral infections, as well as vaccines. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

X-ray observations of symbiotic stars

Energy Technology Data Exchange (ETDEWEB)

Allen, D A [Anglo-Australian Observatory, Epping (Australia)

1981-11-01

Observations of 19 symbiotic stars made with the image proportional counter of the Einstein Observatory are reported. Three were detected as soft X-ray sources. All three have shown slow-nova eruptions in the past 40 years. The data are interpreted as support for a model for slow novae involving thermonuclear events on white dwarfs which accrete from M giant companions. Symbiotic stars in their steady state, not being detected X-ray sources, are presumed to be powered by the accretion process alone.

[Response of arbuscular mycorrhizal fungal lipid metabolism to symbiotic signals in mycorrhiza].

Science.gov (United States)

Tian, Lei; Li, Yuanjing; Tian, Chunjie

2016-01-04

Arbuscular mycorrhizal (AM) fungi play an important role in energy flow and nutrient cycling, besides their wide distribution in the cosystem. With a long co-evolution, AM fungi and host plant have formed a symbiotic relationship, and fungal lipid metabolism may be the key point to find the symbiotic mechanism in arbusculart mycorrhiza. Here, we reviewed the most recent progress on the interaction between AM fungal lipid metabolism and symbiotic signaling networks, especially the response of AM fungal lipid metabolism to symbiotic signals. Furthermore, we discussed the response of AM fungal lipid storage and release to symbiotic or non-symbiotic status, and the correlation between fungal lipid metabolism and nutrient transfer in mycorrhiza. In addition, we explored the feedback of the lipolysis process to molecular signals during the establishment of symbiosis, and the corresponding material conversion and energy metabolism besides the crosstalk of fungal lipid metabolism and signaling networks. This review will help understand symbiotic mechanism of arbuscular mycorrhiza fungi and further application in ecosystem.

Microscopic observation of symbiotic and aposymbiotic juvenile corals in nutrient-enriched seawater.

Science.gov (United States)

Tanaka, Yasuaki; Iguchi, Akira; Inoue, Mayuri; Mori, Chiharu; Sakai, Kazuhiko; Suzuki, Atsushi; Kawahata, Hodaka; Nakamura, Takashi

2013-03-15

Symbiotic and aposymbiotic juvenile corals, which were grown in the laboratory from the gametes of the scleractinian coral Acropora digitifera and had settled down onto plastic culture plates, were observed with a microscope under different nutrient conditions. The symbiotic corals successfully removed the surrounding benthic microalgae (BMA), whereas the aposymbiotic corals were in close physical contact with BMA. The areal growth rate of the symbiotic corals was significantly higher than that of the aposymbiotic corals. The addition of nutrients to the culture seawater increased the chlorophyll a content in the symbiotic coral polyps and enhanced the growth of some of the symbiotic corals, however the average growth rate was not significantly affected, most likely because of the competition with BMA. The comparison between the symbiotic and aposymbiotic juvenile corals showed that the establishment of a symbiotic association could be imperative for post-settlement juvenile corals to survive in high-nutrient seawater. Copyright © 2012 Elsevier Ltd. All rights reserved.

Prevalence of Irritable Bowel Syndrome and Chronic Fatigue 10 Years After Giardia Infection.

Science.gov (United States)

Litleskare, Sverre; Rortveit, Guri; Eide, Geir Egil; Hanevik, Kurt; Langeland, Nina; Wensaas, Knut-Arne

2018-03-06

Irritable bowel syndrome (IBS) is a complication that can follow gastrointestinal infection, but it is not clear if patients also develop chronic fatigue. We investigated the prevalence and odds ratio of IBS and chronic fatigue 10 years after an outbreak of Giardia lamblia, compared with a control cohort, and changes in prevalence over time. We performed a prospective follow-up study of 1252 laboratory-confirmed cases of giardiasis (exposed), which developed in Bergen, Norway in 2004. Statistics Norway provided us with information from 2504 unexposed individuals from Bergen, matched by age and sex (controls). Questionnaires were mailed to participants 3, 6, and 10 years after the outbreak. Results from the 3- and 6-year follow-up analyses have been published previously. We report the 10-year data and changes in prevalence among time points, determined by logistic regression using generalized estimating equations. The prevalence of IBS 10 years after the outbreak was 43% (n = 248) among 576 exposed individuals and 14% (n = 94) among 685 controls (adjusted odds ratio for development of IBS in exposed individuals, 4.74; 95% CI, 3.61-6.23). At this time point, the prevalence of chronic fatigue was 26% (n = 153) among 587 exposed individuals and 11% (n = 73) among 692 controls (adjusted odds ratio, 3.01; 95% CI, 2.22-4.08). The prevalence of IBS among exposed persons did not change significantly from 6 years after infection (40%) to 10 years after infection (43%; adjusted odds ratio for the change 1.03; 95% CI, 0.87-1.22). However, the prevalence of chronic fatigue decreased from 31% at 6 years after infection to 26% at 10 years after infection (adjusted odds ratio for the change 0.74; 95% CI, 0.61-0.90). The prevalence of IBS did not change significantly from 6 years after an outbreak of Giardia lamblia infection in Norway to 10 years after. However, the prevalence of chronic fatigue decreased significantly from 6 to 10 years afterward. IBS and chronic fatigue were

Symbiotic regulation of plant growth, development and reproduction

Science.gov (United States)

Russell J. Rodriguez; D. Carl Freeman; E. Durant McArthur; Yong Ok Kim; Regina S. Redman

2009-01-01

The growth and development of rice (Oryzae sativa) seedlings was shown to be regulated epigenetically by a fungal endophyte. In contrast to un-inoculated (nonsymbiotic) plants, endophyte colonized (symbiotic) plants preferentially allocated resources into root growth until root hairs were well established. During that time symbiotic roots expanded at...

Comprehensive EST analysis of the symbiotic sea anemone, Anemonia viridis.

Science.gov (United States)

Sabourault, Cécile; Ganot, Philippe; Deleury, Emeline; Allemand, Denis; Furla, Paola

2009-07-23

Coral reef ecosystems are renowned for their diversity and beauty. Their immense ecological success is due to a symbiotic association between cnidarian hosts and unicellular dinoflagellate algae, known as zooxanthellae. These algae are photosynthetic and the cnidarian-zooxanthellae association is based on nutritional exchanges. Maintenance of such an intimate cellular partnership involves many crosstalks between the partners. To better characterize symbiotic relationships between a cnidarian host and its dinoflagellate symbionts, we conducted a large-scale EST study on a symbiotic sea anemone, Anemonia viridis, in which the two tissue layers (epiderm and gastroderm) can be easily separated. A single cDNA library was constructed from symbiotic tissue of sea anemones A. viridis in various environmental conditions (both normal and stressed). We generated 39,939 high quality ESTs, which were assembled into 14,504 unique sequences (UniSeqs). Sequences were analysed and sorted according to their putative origin (animal, algal or bacterial). We identified many new repeated elements in the 3'UTR of most animal genes, suggesting that these elements potentially have a biological role, especially with respect to gene expression regulation. We identified genes of animal origin that have no homolog in the non-symbiotic starlet sea anemone Nematostella vectensis genome, but in other symbiotic cnidarians, and may therefore be involved in the symbiosis relationship in A. viridis. Comparison of protein domain occurrence in A. viridis with that in N. vectensis demonstrated an increase in abundance of some molecular functions, such as protein binding or antioxidant activity, suggesting that these functions are essential for the symbiotic state and may be specific adaptations. This large dataset of sequences provides a valuable resource for future studies on symbiotic interactions in Cnidaria. The comparison with the closest available genome, the sea anemone N. vectensis, as well as

Comprehensive EST analysis of the symbiotic sea anemone, Anemonia viridis

Directory of Open Access Journals (Sweden)

Deleury Emeline

2009-07-01

Full Text Available Abstract Background Coral reef ecosystems are renowned for their diversity and beauty. Their immense ecological success is due to a symbiotic association between cnidarian hosts and unicellular dinoflagellate algae, known as zooxanthellae. These algae are photosynthetic and the cnidarian-zooxanthellae association is based on nutritional exchanges. Maintenance of such an intimate cellular partnership involves many crosstalks between the partners. To better characterize symbiotic relationships between a cnidarian host and its dinoflagellate symbionts, we conducted a large-scale EST study on a symbiotic sea anemone, Anemonia viridis, in which the two tissue layers (epiderm and gastroderm can be easily separated. Results A single cDNA library was constructed from symbiotic tissue of sea anemones A. viridis in various environmental conditions (both normal and stressed. We generated 39,939 high quality ESTs, which were assembled into 14,504 unique sequences (UniSeqs. Sequences were analysed and sorted according to their putative origin (animal, algal or bacterial. We identified many new repeated elements in the 3'UTR of most animal genes, suggesting that these elements potentially have a biological role, especially with respect to gene expression regulation. We identified genes of animal origin that have no homolog in the non-symbiotic starlet sea anemone Nematostella vectensis genome, but in other symbiotic cnidarians, and may therefore be involved in the symbiosis relationship in A. viridis. Comparison of protein domain occurrence in A. viridis with that in N. vectensis demonstrated an increase in abundance of some molecular functions, such as protein binding or antioxidant activity, suggesting that these functions are essential for the symbiotic state and may be specific adaptations. Conclusion This large dataset of sequences provides a valuable resource for future studies on symbiotic interactions in Cnidaria. The comparison with the closest

Association of Interleukin-27 gene rs153109 polymorphism and chronic hepatitis B infection

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Samira Mokhtari

2017-04-01

Full Text Available Background: According to World Health Organization (WHO report about 400 million people are chronically infected with hepatitis B virus (HBV. Host immune responses which are mainly controlled by cytokines, can be either effective in disease progression or control the infection. Interleukin-27 (IL-27 is a pro-inflammatory cytokine which promotes Th1 responses. Genetic variations (e.g. single nucleotide polymorphisms [SNPs] can affect the product or activity of IL-27 gene. The aim of present study was to determine the association between IL-27 rs153109 and chronic HBV infection among the Iranian population. Materials and Methods: In this study chronic HBV patients (n=120, Anti-HBc Ab positive and HBsAg positive for more than 6 months and controls (n=120 from healthy individuals referred to Tehran Taleghani hospital (2013-2014 were studied. Genotypes of IL-27 gene polymorphism were detected by PCR-RFLP. DNA sequencing was applied on 10% of samples to validate the genotyping results. The studied variables were polymorphism genotypes/alleles, clinical status, age and gender. Results: Results showed no statistically significant difference for patients and control groups neither in genotype frequencies of AA among the chronic group (30% compared to healthy controls (32.5% (P=0.368; nor in allele frequency A 60.4% for patients against A 59.2% in control groups (P=0.780. Conclusion: Despite the importance of IL-27 in the immune response, the findings of this study suggests that genetic variants of IL-27 SNP 153109A/G were not associated with susceptibility to the chronic infection of HBV.

Evolutionary signals of symbiotic persistence in the legume-rhizobia mutualism.

Science.gov (United States)

Werner, Gijsbert D A; Cornwell, William K; Cornelissen, Johannes H C; Kiers, E Toby

2015-08-18

Understanding the origins and evolutionary trajectories of symbiotic partnerships remains a major challenge. Why are some symbioses lost over evolutionary time whereas others become crucial for survival? Here, we use a quantitative trait reconstruction method to characterize different evolutionary stages in the ancient symbiosis between legumes (Fabaceae) and nitrogen-fixing bacteria, asking how labile is symbiosis across different host clades. We find that more than half of the 1,195 extant nodulating legumes analyzed have a high likelihood (>95%) of being in a state of high symbiotic persistence, meaning that they show a continued capacity to form the symbiosis over evolutionary time, even though the partnership has remained facultative and is not obligate. To explore patterns associated with the likelihood of loss and retention of the N2-fixing symbiosis, we tested for correlations between symbiotic persistence and legume distribution, climate, soil and trait data. We found a strong latitudinal effect and demonstrated that low mean annual temperatures are associated with high symbiotic persistence in legumes. Although no significant correlations between soil variables and symbiotic persistence were found, nitrogen and phosphorus leaf contents were positively correlated with legumes in a state of high symbiotic persistence. This pattern suggests that highly demanding nutrient lifestyles are associated with more stable partnerships, potentially because they "lock" the hosts into symbiotic dependency. Quantitative reconstruction methods are emerging as a powerful comparative tool to study broad patterns of symbiont loss and retention across diverse partnerships.

Evolutionary signals of symbiotic persistence in the legume–rhizobia mutualism

Science.gov (United States)

Werner, Gijsbert D. A.; Cornwell, William K.; Cornelissen, Johannes H. C.; Kiers, E. Toby

2015-01-01

Understanding the origins and evolutionary trajectories of symbiotic partnerships remains a major challenge. Why are some symbioses lost over evolutionary time whereas others become crucial for survival? Here, we use a quantitative trait reconstruction method to characterize different evolutionary stages in the ancient symbiosis between legumes (Fabaceae) and nitrogen-fixing bacteria, asking how labile is symbiosis across different host clades. We find that more than half of the 1,195 extant nodulating legumes analyzed have a high likelihood (>95%) of being in a state of high symbiotic persistence, meaning that they show a continued capacity to form the symbiosis over evolutionary time, even though the partnership has remained facultative and is not obligate. To explore patterns associated with the likelihood of loss and retention of the N2-fixing symbiosis, we tested for correlations between symbiotic persistence and legume distribution, climate, soil and trait data. We found a strong latitudinal effect and demonstrated that low mean annual temperatures are associated with high symbiotic persistence in legumes. Although no significant correlations between soil variables and symbiotic persistence were found, nitrogen and phosphorus leaf contents were positively correlated with legumes in a state of high symbiotic persistence. This pattern suggests that highly demanding nutrient lifestyles are associated with more stable partnerships, potentially because they “lock” the hosts into symbiotic dependency. Quantitative reconstruction methods are emerging as a powerful comparative tool to study broad patterns of symbiont loss and retention across diverse partnerships. PMID:26041807

X-ray observations of symbiotic stars

International Nuclear Information System (INIS)

Allen, D.A.

1981-01-01

Observations of 19 symbiotic stars made with the image proportional counter of the Einstein Observatory are reported. Three were detected as soft X-ray sources. All three have shown slow-nova eruptions in the past 40 years. The data are interpreted as support for a model for slow novae involving thermonuclear events on white dwarfs which accrete from M giant companions. Symbiotic stars in their steady state, not being detected X-ray sources, are presumed to be powered by the accretion process alone. (author)

Exhaled breath analysis using electronic nose in cystic fibrosis and primary ciliary dyskinesia patients with chronic pulmonary infections

DEFF Research Database (Denmark)

Joensen, Odin; Paff, Tamara; Haarman, Eric G

2014-01-01

The current diagnostic work-up and monitoring of pulmonary infections may be perceived as invasive, is time consuming and expensive. In this explorative study, we investigated whether or not a non-invasive exhaled breath analysis using an electronic nose would discriminate between cystic fibrosis...... (CF) and primary ciliary dyskinesia (PCD) with or without various well characterized chronic pulmonary infections. We recruited 64 patients with CF and 21 with PCD based on known chronic infection status. 21 healthy volunteers served as controls. An electronic nose was employed to analyze exhaled......, this method significantly discriminates CF patients suffering from a chronic pulmonary P. aeruginosa (PA) infection from CF patients without a chronic pulmonary infection. Further studies are needed for verification and to investigate the role of electronic nose technology in the very early diagnostic workup...

Two negative regulatory systems of root nodule symbiosis - how are symbiotic benefits and costs balanced?

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Nishida, Hanna; Suzaki, Takuya

2018-05-30

Root nodule symbiosis is one of the best-characterized mutualistic relationships between plants-microbes symbiosis, where mainly leguminous species can obtain nitrogen sources fixed by nitrogen-fixing rhizobia through the formation of symbiotic organs root nodules. In order to drive this symbiotic process, plants need to provide carbon sources that should be used for their growth. Therefore, a balance between the benefits of obtaining nitrogen sources and the costs of losing carbon sources needs to be maintained during root nodule symbiosis. Plants have developed at least two negative regulatory systems of root nodule symbiosis. One strategy involves the regulation of nodule number in response to rhizobial infection. For this regulation, a systemic long-range signaling between roots and shoots called autoregulation of nodulation has a pivotal role. Another strategy involves the regulation of root nodule symbiosis in response to nitrate, the most abundant form of nitrogen nutrients in the soil. Recent studies indicate that a long-distance signaling is shared between the two strategies, where NIN and NRSYM1, two paralogous RWP-RK transcription factors, can activate the production of nodulation-related CLE peptides in response to different inputs. Here, we give an overview of such progress in our understanding of molecular mechanisms relevant to the control of the symbiotic balance, including their biological significance.

Fibrosis assessment in patients with chronic hepatitis B virus (HBV) infection

Science.gov (United States)

Parikh, Pathik; Ryan, John D.

2017-01-01

Chronic hepatitis B virus (HBV) infection is a major cause of liver morbidity and mortality worldwide. While a proportion of the 250 million individuals chronically infected with HBV will not come to significant harm or require therapy, many others risk developing complications of the end-stage liver disease such as decompensated cirrhosis and hepatocellular carcinoma (HCC), without intervention. Due to the complex natural history of HBV infection, patients require an expert assessment to interpret biochemistry, viral serology and appropriately stage the disease, and to initiate monitoring and/or therapy where indicated. The detection and quantification of liver fibrosis is a key factor for disease management and prognostication for an individual with HBV. The reliance on invasive liver biopsy to stage disease is diminishing with the advent of robust non-invasive blood- and imaging-based algorithms which can reliably stage disease in many cases. These tests are now incorporated into International guidelines for HBV management and relied upon daily to inform clinical judgement. Both blood- and imaging-based approaches have advantages over liver biopsy, including minimal risks, lower cost, better patient acceptance and speed of results, while disadvantages include lower diagnostic accuracy in intermediate disease stages and variability with co-existing hepatic inflammation or steatosis. This review outlines the methods of fibrosis assessment in chronic HBV infection and focuses on the most commonly used blood- and imaging-based non-invasive tests, reviewing their diagnostic performance and applicability to patient care. PMID:28251119

Chronic urinary tract infections in patients with spinal cord lesions - biofilm infection with need for long-term antibiotic treatment.

Science.gov (United States)

Tofte, Nete; Nielsen, Alex C Y; Trøstrup, Hannah; Andersen, Christine B; Von Linstow, Michael; Hansen, Birgitte; Biering-Sørensen, Fin; Høiby, Niels; Moser, Claus

2017-04-01

Patients suffering from spinal cord injuries resulting in complete or incomplete paraplegia or tetraplegia are highly disposed to frequent, recurrent or even chronic urinary tract infections (UTIs). The reason for the increased risk of acquiring UTIs is multifactorial, including reduced sensation of classical UTI symptoms, incomplete bladder emptying, frequent catheterizations or chronic urinary tract catheters. Biofilms in relation to UTIs have been shown both on catheters, on concrements or as intracellular bacterial communities (IBCs). Due to the increased risk of acquiring recurrent or chronic UTIs and frequent antibiotic treatments, patients experience an increased risk of being infected with antibiotic-resistant bacteria like extended-spectrum β-lactamase-producing Escherichia coli or Klebsiella spp., but also bacteria like Pseudomonas aeruginosa inherently resistant to several antibiotics. Diagnosing the UTI can also be challenging, especially distinguishing harmless colonization from pathogenic infection. Based on a previous study showing activation of humoral immune response toward UTI pathogens in patients with spinal cord lesions (SCL), the present mini review is an evaluation of using antibody response as an indicator of chronic biofilm UTI. In addition, we evaluated the effect of long-term treatment with antibiotics in patients with SCLs and chronic UTI, defined by culturing of a uropathogen in the urine and elevated specific precipitating antibodies against the same uropathogen in a blood sample. Elimination of chronic UTI, decrease in specific precipitating antibody values and avoiding selection of new multidrug-resistant (MDR) uropathogens were the primary markers for effect of treatment. The results of this evaluation suggest that the long-term treatment strategy in SCL patients with chronic UTI may be effective; however, randomized prospective results are needed to confirm this. © 2017 APMIS. Published by John Wiley & Sons Ltd.

Transient urinary retention and chronic neuropathic pain associated with genital herpes simplex virus infection.

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Haanpää, Maija; Paavonen, Jorma

2004-10-01

Genital herpes (GH) causes genital ulcer disease, severe transient pain, and often paresthesias. Whether or not GH can cause urinary retention or chronic neuropathic pain is not well known. We present two immunocompetent patients with GH associated with neuropathic symptoms. We also review the literature on GH and associated neurologic problems. Patient 1 had primary herpes simplex virus (HSV)-2 infection with transient urinary retention and chronic bilateral neuropathic pain in the sacral area. Patient 2 had recurrent HSV-1 associated with unitaleral chronic neuropathic pain in the sacral area. Although transient urinary retention associated with GH is not uncommon, chronic neuropathic pain has not been reported previously. Our cases show that chronic neuropathic pain, that is "pain initiated or caused by a primary lesion or dysfunction in the nervous system," can follow genital HSV infection.

Hepatitis E virus (HEV) genotype 3 infection of human liver chimeric mice as a model for chronic HEV infection

NARCIS (Netherlands)

M.D.B. van de Garde (Martijn D.B.); S.D. Pas (Suzan); Van Der Net, G. (Guido); R.A. de Man (Robert); A.D.M.E. Osterhaus (Albert); B.L. Haagmans (Bart); P.A. Boonstra (André); T. Vanwolleghem (Thomas)

2016-01-01

textabstractGenotype 3 (gt3) hepatitis E virus (HEV) infections are emerging in Western countries. Immunosuppressed patients are at risk of chronic HEV infection and progressive liver damage, but no adequate model system currently mimics this disease course. Here we explore the possibilities of in

Pattern recognition receptor responses in children with chronic hepatitis B virus infection

DEFF Research Database (Denmark)

Heiberg, Ida Louise; Winther, Thilde Nordmann; Paludan, Søren Riis

2012-01-01

Several studies have demonstrated that hepatitis B virus (HBV) affects the expression and function of Toll like receptors (TLRs), but data on TLR function in HBV infection are mainly from adult patients. The natural history of chronic hepatitis B (CHB) infection is distinctly different in childre...

Physical Structure of Four Symbiotic Binaries

Science.gov (United States)

Kenyon, Scott J. (Principal Investigator)

1997-01-01

Disk accretion powers many astronomical objects, including pre-main sequence stars, interacting binary systems, and active galactic nuclei. Unfortunately, models developed to explain the behavior of disks and their surroundings - boundary layers, jets, and winds - lack much predictive power, because the physical mechanism driving disk evolution - the viscosity - is not understood. Observations of many types of accreting systems are needed to constrain the basic physics of disks and provide input for improved models. Symbiotic stars are an attractive laboratory for studying physical phenomena associated with disk accretion. These long period binaries (P(sub orb) approx. 2-3 yr) contain an evolved red giant star, a hot companion, and an ionized nebula. The secondary star usually is a white dwarf accreting material from the wind of its red giant companion. A good example of this type of symbiotic is BF Cygni: our analysis shows that disk accretion powers the nuclear burning shell of the hot white dwarf and also manages to eject material perpendicular to the orbital plane (Mikolajewska, Kenyon, and Mikolajewski 1989). The hot components in other symbiotic binaries appear powered by tidal overflow from a very evolved red giant companion. We recently completed a study of CI Cygni and demonstrated that the accreting secondary is a solar-type main sequence star, rather than a white dwarf (Kenyon et aL 1991). This project continued our study of symbiotic binary systems. Our general plan was to combine archival ultraviolet and optical spectrophotometry with high quality optical radial velocity observations to determine the variation of line and continuum sources as functions of orbital phase. We were very successful in generating orbital solutions and phasing UV+optical spectra for five systems: AG Dra, V443 Her, RW Hya, AG Peg, and AX Per. Summaries of our main results for these systems appear below. A second goal of our project was to consider general models for the

Simultaneous Chronic Invasive Fungal Infection and Tracheal Fungus Ball Mimicking Cancer in an Immunocompetent Patient

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Erdoğan Çetinkaya

2016-01-01

Full Text Available Fungal infections of the lung are uncommon and mainly affect people with immune deficiency. There are crucial problems in the diagnosis and treatment of this condition. Invasive pulmonary aspergillosis and candidiasis are the most common opportunistic fungal infections. Aspergillus species (spp. are saprophytes molds that exist in nature as spores and rarely cause disease in immunocompetent individuals. In patients with immune deficiency or chronic lung disease, such as cavitary lung disease or bronchiectasis, Aspergillus may cause a variety of aspergillosis infections. Here we present a case of a 57-year-old patient without immunodeficiency or chronic lung disease who was diagnosed with endotracheal fungus ball and chronic fungal infection, possibly due to Aspergillus. Bronchoscopic examination showed a paralyzed right vocal cord and vegetating mass that was yellow in color, at the posterior wall of tracheal lumen. After 3 months, both the parenchymal and tracheal lesions were completely resolved.

Burkholderia cenocepacia Vaginal Infection in Patient with Smoldering Myeloma and Chronic Hepatitis C

OpenAIRE

Petrucca, Andrea; Cipriani, Paola; Sessa, Rosa; Teggi, Antonella; Pustorino, Rosalia; Santapaola, Daniela; Nicoletti, Mauro

2004-01-01

We report a case of a vaginal infection caused by a strain of Burkholderia cenocepacia. The strain was isolated from vaginal swab specimens from a 68-year-old woman with smoldering myeloma and chronic hepatitis C virus infection who was hospitalized for abdominal abscess. Treatment with piperacillin/tazobactam eliminated B. cenocepacia infection and vaginal symptoms.

Coevolution of Symbiotic Species

OpenAIRE

Leok, Boon Tiong Melvin

1996-01-01

This paper will consider the coevolution of species which are symbiotic in their interaction. In particular, we shall analyse the interaction of squirrels and oak trees, and develop a mathematical framework for determining the coevolutionary equilibrium for consumption and production patterns.

Anti-LC1 autoantibodies in patients with chronic hepatitis C virus infection.

Science.gov (United States)

Béland, Kathie; Lapierre, Pascal; Marceau, Gabriel; Alvarez, Fernando

2004-03-01

Various autoantibodies have been reported in patients chronically infected by hepatitis C virus. 2% to 10% of theses patients have anti-liver-kidney microsome type 1 (anti-LKM1) autoantibodies. In type 2 autoimmune hepatitis, anti-LKM1 autoantibodies are frequently associated with anti-liver-cytosol type 1 (anti-LC1) autoantibodies. To determine the prevalence of anti-LC1 autoantibodies in a hepatitis C-positive population and characterize their reactivity. 146 patients suffering from liver diseases, of which 99 were chronically infected by hepatitis C virus, were tested by Western blotting and immunoprecipitation to detect and characterize anti-LC1 autoantibodies. 12% of this hepatitis C population had anti-LC1 autoantibodies. LC1 positivity by Western blotting was 30% of LC1+ sera. Epitopes were found throughout the protein but linear epitopes were situated in the 395-541 amino acid region of formiminotransferase cyclodeaminase. Three putative conformational epitopes were identified by phage display. Anti-LC1 autoantibodies are as prevalent as anti-LKM1 autoantibodies in patients infected with hepatitis C virus and their production is not dependent of anti-LKM1 autoantibodies formation. Autoantibody reactivity against the anti-LC1 antigen is different in hepatitis C than in type 2 autoimmune hepatitis. Anti-LC1 autoantibodies can now be regarded as a serological marker of autoimmunity in chronic hepatitis C infection.

Molybdate transporter ModABC is important for Pseudomonas aeruginosa chronic lung infection.

Science.gov (United States)

Périnet, Simone; Jeukens, Julie; Kukavica-Ibrulj, Irena; Ouellet, Myriam M; Charette, Steve J; Levesque, Roger C

2016-01-12

Mechanisms underlying the success of Pseudomonas aeruginosa in chronic lung infection among cystic fibrosis (CF) patients are poorly defined. The modA gene was previously linked to in vivo competitiveness of P. aeruginosa by a genetic screening in the rat lung. This gene encodes a subunit of transporter ModABC, which is responsible for extracellular uptake of molybdate. This compound is essential for molybdoenzymes, including nitrate reductases. Since anaerobic growth conditions are known to occur during CF chronic lung infection, inactivation of a molybdate transporter could inhibit proliferation through the inactivation of denitrification enzymes. Hence, we performed phenotypic characterization of a modA mutant strain obtained by signature-tagged mutagenesis (STM_modA) and assessed its virulence in vivo with two host models. The STM_modA mutant was in fact defective for anaerobic growth and unable to use nitrates in the growth medium for anaerobic respiration. Bacterial growth and nitrate usage were restored when the medium was supplemented with molybdate. Most significantly, the mutant strain showed reduced virulence compared to wild-type strain PAO1 according to a competitive index in the rat model of chronic lung infection and a predation assay with Dictyostelium discoideum amoebae. As the latter took place in aerobic conditions, the in vivo impact of the mutation in modA appears to extend beyond its effect on anaerobic growth. These results support the modABC-encoded transporter as important for the pathogenesis of P. aeruginosa, and suggest that enzymatic machinery implicated in anaerobic growth during chronic lung infection in CF merits further investigation as a potential target for therapeutic intervention.

Chronic Open Infective Lateral Malleolus Bursitis Management Using Local Rotational Flap

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Yong-Beom Lee

2017-01-01

Full Text Available Background. Using a sinus tarsi rotational flap is an uncommon approach to treating chronic open infective lateral malleolus bursitis. Methods. We treated eight patients, including six males, using this approach. First, we debrided all the infected tissues and used a negative pressure wound closure system where needed. After acute infection had been controlled, the local rotational flap was used for cases where the wound could not be closed by a simple suture or bone exposure. The rotational flap was detached with a curved skin incision at the sinus tarsi next to the open wound and sutured to the defect, paying careful attention to the superficial peroneal nerve. The donor site was managed with a split-thickness skin graft. Results. The patients’ mean age was 74.1 years. Six patients had a wound after suppurative infection, but two patients had ulcer-type bursitis. Six patients demonstrated full flap healing, but two patients had venous congestion necrosis. Conclusion. A sinus tarsi rotational flap is a useful method to ensure healing and coverage of chronic open lateral malleolus bursitis, especially for small to medium wounds with cavity and bone exposure.

Development of an in vivo model of Chlamydia abortus chronic infection in mice overexpressing IL-10.

Science.gov (United States)

Del Río, Laura; Murcia, Antonio; Buendía, Antonio J; Álvarez, Daniel; Ortega, Nieves; Navarro, José A; Salinas, Jesús; Caro, María Rosa

2018-01-01

Chlamydia abortus, like other members of the family Chlamydiaceae, have a unique intracellular developmental cycle that is characterized by its chronic nature. Infection of a flock can remain undetected for months, until abortion occurs the following reproductive season but, to date, neither the location nor the mechanisms that maintain this latent phase are fully understood. Studies have shown that IL-10 produced as a response to certain micro-organisms sustains the intracellular survival of pathogens and increases host susceptibility to chlamydial infections. In order to induce a sustained infection C. abortus, transgenic mice that constitutively express IL-10 were infected and the immunological mechanisms that maintain infection in these mice were compared with the mechanisms of a resistant wild-type mouse strain. Viable bacteria could be detected in different tissues of transgenic mice up to 28 days after infection, as analysed by bacterial isolation and immunohistochemistry. Chronic infection in these mice was associated with an impaired recruitment of macrophages, decreased iNOS activity at the site of infection and a more diffuse distribution of inflammatory cells in the liver. This murine model can be of great help for understanding the immunological and bacterial mechanisms that lead to chronic chlamydial infections. Copyright © 2017 Elsevier B.V. All rights reserved.

Experimental chronic hepatitis B infection of neonatal tree shrews (Tupaia belangeri chinensis: A model to study molecular causes for susceptibility and disease progression to chronic hepatitis in humans

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Wang Qi

2012-08-01

Full Text Available Abstract Background Hepatitis B virus (HBV infection continues to be an escalating global health problem. Feasible and effective animal models for HBV infection are the prerequisite for developing novel therapies for this disease. The tree shrew (Tupaia is a small animal species evolutionary closely related to humans, and thus is permissive to certain human viral pathogens. Whether tree shrews could be chronically infected with HBV in vivo has been controversial for decades. Most published research has been reported on adult tree shrews, and only small numbers of HBV infected newborn tree shrews had been observed over short time periods. We investigated susceptibility of newborn tree shrews to experimental HBV infection as well as viral clearance over a protracted time period. Results Forty-six newborn tree shrews were inoculated with the sera from HBV-infected patients or tree shrews. Serum and liver samples of the inoculated animals were periodically collected and analyzed using fluorescence quantitative polymerase chain reaction, enzyme-linked immunosorbent assay, Southern blot, and immunohistochemistry. Six tree shrews were confirmed and four were suspected as chronically HBV-infected for more than 48 (up to 228 weeks after inoculation, including three that had been inoculated with serum from a confirmed HBV-infected tree shrew. Conclusions Outbred neonatal tree shrews can be long-term chronically infected with HBV at a frequency comparable to humans. The model resembles human disease where also a smaller proportion of infected individuals develop chronic HBV related disease. This model might enable genetic and immunologic investigations which would allow determination of underlying molecular causes favoring susceptibility for chronic HBV infection and disease establishment vs. viral clearance.

Managing an Acute and Chronic Periprosthetic Infection

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Cristian Barrientos

2017-01-01

Full Text Available A case report of a 65-year-old female with a history of right total hip arthroplasty (THA in 2007 and left THA in 2009 was presented. She consulted with our institution for the first time, on December 2013, for right hip pain and fistula on the THA incision. It was managed as a chronic infection, so a two-stage revision was performed. First-time intraoperative cultures were positive for Staphylococcus aureus (3/5 and Proteus mirabilis (2/5. Three weeks after the second half of the review, it evolved with acute fever and pain in relation to right hip. No antibiotics were used, arthrocentesis was performed, and a coagulase-negative staphylococci multisensible was isolated at the 5th day. Since the germ was different from the first revision, it was decided to perform a one-stage revision. One year after the first review, the patient has no local signs of infection and presents ESV and RPC in normal limits. The indication and management of periprosthetic infections are discussed.

The role of pharmacogenetics in the treatment of chronic hepatitis C infection.

Science.gov (United States)

Kawaguchi-Suzuki, Marina; Frye, Reginald F

2014-02-01

Hepatitis C virus (HCV) chronically infects 170 million people worldwide. Until recently, combination therapy with peginterferon-α (pegIFN) and ribavirin (RBV) has been the standard of care. However, for many patients, especially those infected with the most common HCV genotype 1 (HCV-1), this treatment has resulted in unsatisfactory treatment response rates. Many clinical factors, including pharmacogenetics, influence the treatment response rate. Genetic variation in the interleukin 28B (IL28B) gene is the major determinant of treatment response, a finding that has been replicated in multiple independent cohorts. This review focuses on the association between pharmacogenetics and conventional pegIFN/RBV therapy in patients infected with HCV non-genotype 1; patients reinfected with HCV after liver transplantation; and patients coinfected with HCV and human immunodeficiency virus. We also review the pharmacogenetic data for boceprevir and telaprevir triple therapy in patients with HCV-1 infection, as well as viral genomic polymorphisms and genetic variants that may protect against anemia. Pharmacogenetic information offers a personalized medicine approach to help clinicians and patients make better informed decisions to maximize response and minimize toxicity for the treatment of chronic HCV infection. © 2013 Pharmacotherapy Publications, Inc.

Changes of Treg and Th17 cells balance in the development of acute and chronic hepatitis B virus infection

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Xue-Song Liang

2012-05-01

Full Text Available Abstract Background Many studies suggest that in chronic hepatitis B virus (HBV infection regulate T (Treg cells and interlukin-17-producing T help cells (Th17 are mutually antagonistic in the immune response. This study is aimed to reveal the cell differentiation environment and the significance of Treg and Th17 balance in the development of acute and chronic HBV infection. Methods Ten patients with acute HBV infection (AHB and forty-eight patients with chronic HBV infection, including 12 asymptomatic HBV carriers (HBV carriers, 18 chronic hepatitis B patients (CHB and 18 acute-on-chronic HBV-related liver failure (ACHBLF were enrolled. Treg and Th17 cells differentiation related cytokine levels were detected by using ELISA. Flow cytometry was employed to count the Treg and Th17 frequency in peripheral blood. Results Compared to health controls both AHB and ACHBLF patients favoured Th17 cell differentiation, accompanied by a higher proportion of peripheral Th17 cells (P  Conclusions Th17 cells are involved in acute and chronic HBV infection, especially in AHB and ACHBLF. CHB and ACHBLF patients manifested obvious Treg/Th17 ratio imbalance, which might be linked to disease progression and the continuous HBV infection.

Chronic urinary tract infections in patients with spinal cord lesions – biofilm infection with need for long-term antibiotic treatment

DEFF Research Database (Denmark)

Tofte, Nete; Nielsen, Alex C.Y.; Trøstrup, Hannah

2017-01-01

Patients suffering from spinal cord injuries resulting in complete or incomplete paraplegia or tetraplegia are highly disposed to frequent, recurrent or even chronic urinary tract infections (UTIs). The reason for the increased risk of acquiring UTIs is multifactorial, including reduced sensation...... of classical UTI symptoms, incomplete bladder emptying, frequent catheterizations or chronic urinary tract catheters. Biofilms in relation to UTIs have been shown both on catheters, on concrements or as intracellular bacterial communities (IBCs). Due to the increased risk of acquiring recurrent or chronic UTIs...... the UTI can also be challenging, especially distinguishing harmless colonization from pathogenic infection. Based on a previous study showing activation of humoral immune response toward UTI pathogens in patients with spinal cord lesions (SCL), the present mini review is an evaluation of using antibody...

Important Late-Stage Symbiotic Role of the Sinorhizobium meliloti Exopolysaccharide Succinoglycan.

Science.gov (United States)

Arnold, Markus F F; Penterman, Jon; Shabab, Mohammed; Chen, Esther J; Walker, Graham C

2018-07-01

Sinorhizobium meliloti enters into beneficial symbiotic interactions with Medicago species of legumes. Bacterial exopolysaccharides play critical signaling roles in infection thread initiation and growth during the early stages of root nodule formation. After endocytosis of S. meliloti by plant cells in the developing nodule, plant-derived nodule-specific cysteine-rich (NCR) peptides mediate terminal differentiation of the bacteria into nitrogen-fixing bacteroids. Previous transcriptional studies showed that the intensively studied cationic peptide NCR247 induces expression of the exo genes that encode the proteins required for succinoglycan biosynthesis. In addition, genetic studies have shown that some exo mutants exhibit increased sensitivity to the antimicrobial action of NCR247. Therefore, we investigated whether the symbiotically active S. meliloti exopolysaccharide succinoglycan can protect S. meliloti against the antimicrobial activity of NCR247. We discovered that high-molecular-weight forms of succinoglycan have the ability to protect S. meliloti from the antimicrobial action of the NCR247 peptide but low-molecular-weight forms of wild-type succinoglycan do not. The protective function of high-molecular-weight succinoglycan occurs via direct molecular interactions between anionic succinoglycan and the cationic NCR247 peptide, but this interaction is not chiral. Taken together, our observations suggest that S. meliloti exopolysaccharides not only may be critical during early stages of nodule invasion but also are upregulated at a late stage of symbiosis to protect bacteria against the bactericidal action of cationic NCR peptides. Our findings represent an important step forward in fully understanding the complete set of exopolysaccharide functions during legume symbiosis. IMPORTANCE Symbiotic interactions between rhizobia and legumes are economically important for global food production. The legume symbiosis also is a major part of the global nitrogen

Tricycloalternarene Analogs from a Symbiotic Fungus Aspergillus sp. D and Their Antimicrobial and Cytotoxic Effects.

Science.gov (United States)

Zhang, Huawei; Zhao, Ziping; Chen, Jianwei; Bai, Xuelian; Wang, Hong

2018-04-09

Bioassay-guided fractionation of the crude extract of fermentation broth of one symbiotic strain Aspergillus sp. D from the coastal plant Edgeworthia chrysantha Lindl. led to isolation of one new meroterpenoid, tricycloalternarene 14b ( 1 ), together with four known analogs ( 2 - 5 ), tricycloalternarenes 2b ( 2 ), 3a ( 3 ), 3b ( 4 ), and ACTG-toxin F ( 5 ). Their chemical structures were unambiguously established on the basis of NMR, mass spectrometry, and optical rotation data analysis, as well as by comparison with literature data. Biological assays indicated that compound 2 exhibited potent in vitro cytotoxicity against human lung adenocarcinoma A549 cell line with an IC 50 value of 2.91 μM, and compound 5 had a moderate inhibitory effect on Candida albicans , with an MIC value of 15.63 μM. The results indicated that this symbiotic strain D is an important producer of tricycloalternarene derivatives, with potential therapeutic application in treatment of cancer and pathogen infection.

SEARCHING FOR NEW YELLOW SYMBIOTIC STARS: POSITIVE IDENTIFICATION OF StHα63

Energy Technology Data Exchange (ETDEWEB)

Baella, N. O. [Unidad de Astronomía, Instituto Geofísico del Perú, Lima, Per (Peru); Pereira, C. B.; Alvarez-Candal, A. [Observatório Nacional/MCTI, Rua Gen. José Cristino, 77, 20921-400, Rio de Janeiro (Brazil); Miranda, L. F., E-mail: nobar.baella@gmail.com, E-mail: claudio@on.br, E-mail: alvarez@on.br, E-mail: lfm@iaa.es [Instituto de Astrofísica de Andalucía- CSIC, C/Glorieta de la Astronomía s/n, E-18008 Granada (Spain)

2016-04-15

Yellow symbiotic stars are useful targets for probing whether mass transfer has happened in their binary systems. However, the number of known yellow symbiotic stars is very scarce. We report spectroscopic observations of five candidate yellow symbiotic stars that were selected by their positions in the 2MASS (J − H) versus (H − K{sub s}) diagram and which were included in some emission-line catalogs. Among the five candidates, only StHα63 is identified as a new yellow symbiotic star because of its spectrum and its position in the [TiO]{sub 1}–[TiO]{sub 2} diagram, which indicates a K4–K6 spectral type. In addition, the derived electron density (∼10{sup 8.4} cm{sup −3}) and several emission-line intensity ratios provide further support for that classification. The other four candidates are rejected as symbiotic stars because three of them actually do not show emission lines and the fourth one only Balmer emission lines. We also found that the WISE W3–W4 index clearly separates normal K-giants from yellow symbiotic stars and therefore can be used as an additional tool for selecting candidate yellow symbiotic stars.

Novel, non-symbiotic isolates of Neorhizobium from a dryland agricultural soil.

Science.gov (United States)

Soenens, Amalia; Imperial, Juan

2018-01-01

Semi-selective enrichment, followed by PCR screening, resulted in the successful direct isolation of fast-growing Rhizobia from a dryland agricultural soil. Over 50% of these isolates belong to the genus Neorhizobium , as concluded from partial rpoB and near-complete 16S rDNA sequence analysis. Further genotypic and genomic analysis of five representative isolates confirmed that they form a coherent group within Neorhizobium , closer to N. galegae than to the remaining Neorhizobium species, but clearly differentiated from the former, and constituting at least one new genomospecies within Neorhizobium. All the isolates lacked nod and nif symbiotic genes but contained a repABC replication/maintenance region, characteristic of rhizobial plasmids, within large contigs from their draft genome sequences. These repABC sequences were related, but not identical, to repABC sequences found in symbiotic plasmids from N. galegae , suggesting that the non-symbiotic isolates have the potential to harbor symbiotic plasmids. This is the first report of non-symbiotic members of Neorhizobium from soil.

The collective radio properties of symbiotic stars

International Nuclear Information System (INIS)

Seaquist, E.R.; Taylor, A.R.

1990-01-01

Radio measurements of symbiotic stars are reported which extend the search for radio emission and provide multifrequency and multiepoch measurements of previously detected stars. The results show no evidence that there are time variations in excess of about 30 percent over a period of several years in the detected stars. The radio flux densities are correlated with brightness in the IR, especially at the longer IR wavelengths where dust emission dominates. It is confirmed that symbiotics with the latest red giant spectral types are the most luminous radio emitters. The D-types are the most radio-luminous. Virtually all detected stars with measurements at more than one frequency exhibit a positive spectral index, consistent with optically thick thermal bremsstrahlung. The binary separation for a number of radio-emitting symbiotics is estimated, and it is found that the distribution of inferred binary separations is dramatically different for IR D-types than for S-types. 37 refs

Chronic kidney disease of uncertain etiology in Sri Lanka: Are leptospirosis and Hantaviral infection likely causes?

Science.gov (United States)

Gamage, Chandika Damesh; Sarathkumara, Yomani Dilukshi

2016-06-01

Chronic kidney disease of uncertain etiology (CKDu) has been a severe burden and a public health crisis in Sri Lanka over the past two decades. Many studies have established hypotheses to identify potential risk factors although causative agents, risk factors and etiology of this disease are still uncertain. Several studies have postulated that fungal and bacterial nephrotoxins are a possible etiological factor; however, the precise link between hypothesized risk factors and the pathogenesis of chronic kidney disease has yet to be proven in prior studies. Leptospirosis and Hantavirus infections are important zoonotic diseases that are naturally maintained and transmitted via infected rodent populations and which present similar clinical and epidemiological features. Both infections are known to be a cause of acute kidney damage that can proceed into chronic renal failure. Several studies have reported presence of both infections in Sri Lanka. Therefore, we hypothesized that pathogenic Leptospira or Hantavirus are possible causative agents of acute kidney damage which eventually progresses to chronic kidney disease in Sri Lanka. The proposed hypothesis will be evaluated by means of an observational study design. Past infection will be assessed by a cross-sectional study to detect the presence of IgG antibodies with further confirmatory testing among chronic kidney disease patients and individuals from the community in selected endemic areas compared to low prevalence areas. Identification of possible risk factors for these infections will be followed by a case-control study and causality will be further determined with a cohort study. If the current hypothesis is true, affected communities will be subjected for medical interventions related to the disease for patient management while considering supportive therapies. Furthermore and possibly enhance their preventive and control measures to improve vector control to decrease the risk of infection. Copyright © 2016

Mupirocin in the Treatment of Staphylococcal Infections in Chronic Rhinosinusitis: A Meta-Analysis.

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Jong Seung Kim

Full Text Available Saline irrigation of the nasal cavity is a classic and effective treatment for acute or chronic rhinosinusitis. Topical antibiotics such as mupirocin have been widely used for recalcitrant chronic rhinosinusitis. Therefore, the purpose of this study was to evaluate the effect of saline irrigation using mupirocin.A systematic literature review and meta-analysis of mupirocin saline irrigation were performed using EMBASE, MEDLINE, and Cochrane library through December 2015. Data were analyzed with R 3.2.2 software. A random effects model was used because of the diversity of included studies. Sensitivity analysis of particular tested groups and single proportion tests were also performed. The main outcome measure was residual staphylococcal infection, as confirmed by culture or PCR.Two RCTs, two prospective studies and two retrospective studies were included. A random effects model meta-analysis of the pooled data identified a relative risk of residual infection of 0.13 (95% CI: 0.06-0.26, p<0.05 with low heterogeneity (I2 = 0%. The proportion of residual staphylococcal infections after 1 month was 0.08 (95% CI: 0.04-0.16. However, this proportion increased to 0.53 at 6 months (95% CI: 0.27-0.78.The short-term use of mupirocin has a strongly reductive effect on staphylococcal infection in chronic rhinosinusitis. Although there is currently a lack of clear evidence, future studies with well-designed inclusion criteria and randomized controlled trials are needed to examine mupirocin's long-term effect on chronic rhinosinusitis.

NAD1 Controls Defense-Like Responses in Medicago truncatula Symbiotic Nitrogen Fixing Nodules Following Rhizobial Colonization in a BacA-Independent Manner

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Domonkos, Ágota; Kovács, Szilárd; Gombár, Anikó; Kiss, Ernő; Horváth, Beatrix; Kováts, Gyöngyi Z.; Farkas, Attila; Tóth, Mónika T.; Ayaydin, Ferhan; Bóka, Károly; Fodor, Lili; Endre, Gabriella; Kaló, Péter

2017-01-01

Legumes form endosymbiotic interaction with host compatible rhizobia, resulting in the development of nitrogen-fixing root nodules. Within symbiotic nodules, rhizobia are intracellularly accommodated in plant-derived membrane compartments, termed symbiosomes. In mature nodule, the massively colonized cells tolerate the existence of rhizobia without manifestation of visible defense responses, indicating the suppression of plant immunity in the nodule in the favur of the symbiotic partner. Medicago truncatula DNF2 (defective in nitrogen fixation 2) and NAD1 (nodules with activated defense 1) genes are essential for the control of plant defense during the colonization of the nitrogen-fixing nodule and are required for bacteroid persistence. The previously identified nodule-specific NAD1 gene encodes a protein of unknown function. Herein, we present the analysis of novel NAD1 mutant alleles to better understand the function of NAD1 in the repression of immune responses in symbiotic nodules. By exploiting the advantage of plant double and rhizobial mutants defective in establishing nitrogen-fixing symbiotic interaction, we show that NAD1 functions following the release of rhizobia from the infection threads and colonization of nodule cells. The suppression of plant defense is self-dependent of the differentiation status of the rhizobia. The corresponding phenotype of nad1 and dnf2 mutants and the similarity in the induction of defense-associated genes in both mutants suggest that NAD1 and DNF2 operate close together in the same pathway controlling defense responses in symbiotic nodules. PMID:29240711

NAD1 Controls Defense-Like Responses in Medicago truncatula Symbiotic Nitrogen Fixing Nodules Following Rhizobial Colonization in a BacA-Independent Manner

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Ágota Domonkos

2017-12-01

Full Text Available Legumes form endosymbiotic interaction with host compatible rhizobia, resulting in the development of nitrogen-fixing root nodules. Within symbiotic nodules, rhizobia are intracellularly accommodated in plant-derived membrane compartments, termed symbiosomes. In mature nodule, the massively colonized cells tolerate the existence of rhizobia without manifestation of visible defense responses, indicating the suppression of plant immunity in the nodule in the favur of the symbiotic partner. Medicago truncatula DNF2 (defective in nitrogen fixation 2 and NAD1 (nodules with activated defense 1 genes are essential for the control of plant defense during the colonization of the nitrogen-fixing nodule and are required for bacteroid persistence. The previously identified nodule-specific NAD1 gene encodes a protein of unknown function. Herein, we present the analysis of novel NAD1 mutant alleles to better understand the function of NAD1 in the repression of immune responses in symbiotic nodules. By exploiting the advantage of plant double and rhizobial mutants defective in establishing nitrogen-fixing symbiotic interaction, we show that NAD1 functions following the release of rhizobia from the infection threads and colonization of nodule cells. The suppression of plant defense is self-dependent of the differentiation status of the rhizobia. The corresponding phenotype of nad1 and dnf2 mutants and the similarity in the induction of defense-associated genes in both mutants suggest that NAD1 and DNF2 operate close together in the same pathway controlling defense responses in symbiotic nodules.

NAD1 Controls Defense-Like Responses in Medicago truncatula Symbiotic Nitrogen Fixing Nodules Following Rhizobial Colonization in a BacA-Independent Manner.

Science.gov (United States)

Domonkos, Ágota; Kovács, Szilárd; Gombár, Anikó; Kiss, Ernő; Horváth, Beatrix; Kováts, Gyöngyi Z; Farkas, Attila; Tóth, Mónika T; Ayaydin, Ferhan; Bóka, Károly; Fodor, Lili; Ratet, Pascal; Kereszt, Attila; Endre, Gabriella; Kaló, Péter

2017-12-14

Legumes form endosymbiotic interaction with host compatible rhizobia, resulting in the development of nitrogen-fixing root nodules. Within symbiotic nodules, rhizobia are intracellularly accommodated in plant-derived membrane compartments, termed symbiosomes. In mature nodule, the massively colonized cells tolerate the existence of rhizobia without manifestation of visible defense responses, indicating the suppression of plant immunity in the nodule in the favur of the symbiotic partner. Medicago truncatula DNF2 (defective in nitrogen fixation 2) and NAD1 (nodules with activated defense 1) genes are essential for the control of plant defense during the colonization of the nitrogen-fixing nodule and are required for bacteroid persistence. The previously identified nodule-specific NAD1 gene encodes a protein of unknown function. Herein, we present the analysis of novel NAD1 mutant alleles to better understand the function of NAD1 in the repression of immune responses in symbiotic nodules. By exploiting the advantage of plant double and rhizobial mutants defective in establishing nitrogen-fixing symbiotic interaction, we show that NAD1 functions following the release of rhizobia from the infection threads and colonization of nodule cells. The suppression of plant defense is self-dependent of the differentiation status of the rhizobia. The corresponding phenotype of nad1 and dnf2 mutants and the similarity in the induction of defense-associated genes in both mutants suggest that NAD1 and DNF2 operate close together in the same pathway controlling defense responses in symbiotic nodules.

Positive signature-tagged mutagenesis in Pseudomonas aeruginosa: tracking patho-adaptive mutations promoting airways chronic infection.

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Irene Bianconi

2011-02-01

Full Text Available The opportunistic pathogen Pseudomonas aeruginosa can establish life-long chronic infections in the airways of cystic fibrosis (CF patients. Persistent lifestyle is established with P. aeruginosa patho-adaptive variants, which are clonal with the initially-acquired strains. Several reports indicated that P. aeruginosa adapts by loss-of-function mutations which enhance fitness in CF airways and sustain its clonal expansion during chronic infection. To validate this model of P. aeruginosa adaptation to CF airways and to identify novel genes involved in this microevolution, we designed a novel approach of positive-selection screening by PCR-based signature-tagged mutagenesis (Pos-STM in a murine model of chronic airways infection. A systematic positive-selection scheme using sequential rounds of in vivo screenings for bacterial maintenance, as opposed to elimination, generated a list of genes whose inactivation increased the colonization and persistence in chronic airways infection. The phenotypes associated to these Pos-STM mutations reflect alterations in diverse aspects of P. aeruginosa biology which include lack of swimming and twitching motility, lack of production of the virulence factors such as pyocyanin, biofilm formation, and metabolic functions. In addition, Pos-STM mutants showed altered invasion and stimulation of immune response when tested in human respiratory epithelial cells, indicating that P. aeruginosa is prone to revise the interaction with its host during persistent lifestyle. Finally, sequence analysis of Pos-STM genes in longitudinally P. aeruginosa isolates from CF patients identified signs of patho-adaptive mutations within the genome. This novel Pos-STM approach identified bacterial functions that can have important clinical implications for the persistent lifestyle and disease progression of the airway chronic infection.

Polarimetry of symbiotic stars

International Nuclear Information System (INIS)

Piirola, V.

1983-01-01

Five symbiotic stars have been observed for linear polarization (UBVRI) in September 1981. Three systems, CH Cyg, CI Cyg and AG Peg show intrinsic polarization while in the case of Z And and AX Per the observed polarization seems to be mostly of interstellar origin. The position angle of polarization of CI Cyg and AG Peg rotates strongly vs. wavelength, as observed also for CH Cyg in 1977-80. The polarization of CH Cyg has decreased since May 1980, especially in the I, R and U bands, so that the maximum polarization is now in the blue (Psub(B) approx. 0.3%). Probably one is monitoring the formation, growth and disappearance of dust particles in the atmosphere of this star. Two related systems, PU Vul (Nova Vul 1979) and R Aql (Mira) have polarization behaviour rather similar to that of symbiotic stars which suggests that the M type giant present in these systems is responsible for most of the intrinsic polarization. (Auth.)

Iron status and anaemia of chronic disease in HIV-infected African ...

African Journals Online (AJOL)

2009-03-11

Mar 11, 2009 ... A large percentage of women had anaemia of chronic disease, with HIV-infected ... subjects were recruited per week over a 25-week period (March 2000 ..... Washington DC: Academy for Educational Development; 1993.

Recurrent paratyphoid fever A co-infected with hepatitis A reactivated chronic hepatitis B.

Science.gov (United States)

Liu, Yanling; Xiong, Yujiao; Huang, Wenxiang; Jia, Bei

2014-05-12

We report here a case of recurrent paratyphoid fever A with hepatitis A co-infection in a patient with chronic hepatitis B. A 26-year-old male patient, who was a hepatitis B virus carrier, was co-infected with Salmonella enterica serovar Paratyphi A and hepatitis A virus. The recurrence of the paratyphoid fever may be ascribed to the coexistence of hepatitis B, a course of ceftriaxone plus levofloxacin that was too short and the insensitivity of paratyphoid fever A to levofloxacin. We find that an adequate course and dose of ceftriaxone is a better strategy for treating paratyphoid fever. Furthermore, the co-infection of paratyphoid fever with hepatitis A may stimulate cellular immunity and break immunotolerance. Thus, the administration of the anti-viral agent entecavir may greatly improve the prognosis of this patient with chronic hepatitis B, and the episodes of paratyphoid fever and hepatitis A infection prompt the use of timely antiviral therapy.

Radio observations of symbiotic stars

Energy Technology Data Exchange (ETDEWEB)

Wright, A E [Commonwealth Scientific and Industrial Research Organization, Epping (Australia). Div. of Radiophysics; Allen, D A

1978-09-01

A search for 2-cm continuum emission from 91 symbiotic stars has been undertaken using the Parkes radio telescope. Nine sources have been detected, four of which are reported for the first time. The radio spectral indices are mostly about + 0.6; these are interpreted in terms of mass loss. In two stars a portion of the radio spectrum has an index of zero, and for one of these stars (RX Puppis) this is plausibly a manifestation of the cessation of symbiotic activity that occurred about two decades ago. There is an extraordinarily good correlation between the detectability at 2cm and the presence of circumstellar dust, but not between the radio and optical domains. The importance of continued radio monitoring of HM Sagittae over the next few years is stressed.

Rhinovirus genome variation during chronic upper and lower respiratory tract infections.

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Caroline Tapparel

Full Text Available Routine screening of lung transplant recipients and hospital patients for respiratory virus infections allowed to identify human rhinovirus (HRV in the upper and lower respiratory tracts, including immunocompromised hosts chronically infected with the same strain over weeks or months. Phylogenetic analysis of 144 HRV-positive samples showed no apparent correlation between a given viral genotype or species and their ability to invade the lower respiratory tract or lead to protracted infection. By contrast, protracted infections were found almost exclusively in immunocompromised patients, thus suggesting that host factors rather than the virus genotype modulate disease outcome, in particular the immune response. Complete genome sequencing of five chronic cases to study rhinovirus genome adaptation showed that the calculated mutation frequency was in the range observed during acute human infections. Analysis of mutation hot spot regions between specimens collected at different times or in different body sites revealed that non-synonymous changes were mostly concentrated in the viral capsid genes VP1, VP2 and VP3, independent of the HRV type. In an immunosuppressed lung transplant recipient infected with the same HRV strain for more than two years, both classical and ultra-deep sequencing of samples collected at different time points in the upper and lower respiratory tracts showed that these virus populations were phylogenetically indistinguishable over the course of infection, except for the last month. Specific signatures were found in the last two lower respiratory tract populations, including changes in the 5'UTR polypyrimidine tract and the VP2 immunogenic site 2. These results highlight for the first time the ability of a given rhinovirus to evolve in the course of a natural infection in immunocompromised patients and complement data obtained from previous experimental inoculation studies in immunocompetent volunteers.

Detection of Porphyromonas gingivalis, Porphyromonas endodontalis, Prevotella intermedia, and Prevotella nigrescens in chronic endodontic infection.

Science.gov (United States)

Tomazinho, Luiz Fernando; Avila-Campos, Mario J

2007-02-01

Black-pigmented anaerobic rods such as Prevotella spp. and Porphyromonas spp. are involved in the etiology and perpetuation of endodontic infections. The aim of this study was to evaluate the prevalence of these species in chronic endodontic infections by using culture and polymerase chain reaction (PCR) techniques. Samples of 100 patients with root canals displaying chronic endodontic infections were obtained by sterilized paper points. Bacterial identification was performed by using culture and PCR techniques. By culture, in 33% of the samples, P. intermedia-P. nigrescens (75.8%), P. gingivalis (27.3%), and P. endodontalis (9.1%) were identified, and by PCR 60% of the samples harbored P. nigrescens (43.3%), P. gingivalis (43.3%), P. intermedia (31.7%), and P. endodontalis (23.3%). The presence of these black-pigmented anaerobic rods alone or in association in chronic endodontic infections seems to be frequent. PCR is a very sensitive technique for detecting DNA from bacterial cells. Culturing is only able to reveal living bacteria and is less sensitive for the identification of low numbers of bacterial cells.

Structured approach to design of diagnostic test evaluation studies for chronic progressive infections in animals

DEFF Research Database (Denmark)

Nielsen, Søren Saxmose; Toft, Nils; Gardner, Ian Andrew

2011-01-01

Diagnostic test evaluations (DTEs) for chronic infections are challenging because a protracted incubation period has to be considered in the design of the DTE, and the adverse effects of infection may be widespread and progressive over an animal's entire life. Frequently, the specific purpose......) than originally intended. The objective of this paper is to outline a structured approach to the design and conduct of a DTE for diagnostic tests used for chronic infections in animals, and intended for different purposes. We describe the process from reflections about test purpose and the underlying...... of the test is not formally considered when a test is evaluated. Therefore, the result is often a DTE where test sensitivity and specificity estimates are biased, either because of problems with establishing the true infection status or because the test detects another aspect of the infection (and analyte...

Effect of Subliminal Stimulation of Symbiotic Fantasies on Behavior Modification Treatment of Obesity.

Science.gov (United States)

And Others; Silverman, Lloyd H.

1978-01-01

Obese women were treated in behavior modification programs for overeating. Behavior programs were accompanied by subliminal stimulation and by symbiotic and control messages. The symbiotic condition gave evidence of enhancing weight loss. This finding supports the proposition that subliminal stimulation of symbiotic fantasies can enhance the…

Symbiotic stars as an old disk population

Energy Technology Data Exchange (ETDEWEB)

Wallerstein, G [Joint Inst. for Lab. Astrophysics, Boulder, CO (USA)

1981-10-01

A table of all symbiotic stars in the General Catalogue of Variable Stars and its supplements has been assembled and their radial velocities have been discussed. A velocity dispersion of 63 +- 14 km/s is found for all the stars and a value of 58 +- 14 km/s is established if the probable halo star, AG Dra, is omitted. The space distribution is similar to that of an old disk population. Some implications of low masses for the symbiotic stars are discussed, and some suggestions are made regarding possibly useful observations.

Isolation and characterization of a virus (CvV-BW1 that infects symbiotic algae of Paramecium bursaria in Lake Biwa, Japan

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Kasahara Masahiro

2010-09-01

Full Text Available Abstract Background We performed an environmental study of viruses infecting the symbiotic single-celled algae of Paramecium bursaria (Paramecium bursaria Chlorella virus, PBCV in Lake Biwa, the largest lake in Japan. The viruses detected were all Chlorella variabilis virus (CvV = NC64A virus. One of them, designated CvV-BW1, was subjected to further characterization. Results CvV-BW1 formed small plaques and had a linear DNA genome of 370 kb, as judged by pulsed-field gel electrophoresis. Restriction analysis indicated that CvV-BW1 DNA belongs to group H, one of the most resistant groups among CvV DNAs. Based on a phylogenetic tree constructed using the dnapol gene, CvV was classified into two clades, A and B. CvV-BW1 belonged to clade B, in contrast to all previously identified virus strains of group H that belonged to clade A. Conclusions We conclude that CvV-BW1 composes a distinct species within C. variabilis virus.

Novel, non-symbiotic isolates of Neorhizobium from a dryland agricultural soil

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Amalia Soenens

2018-05-01

Full Text Available Semi-selective enrichment, followed by PCR screening, resulted in the successful direct isolation of fast-growing Rhizobia from a dryland agricultural soil. Over 50% of these isolates belong to the genus Neorhizobium, as concluded from partial rpoB and near-complete 16S rDNA sequence analysis. Further genotypic and genomic analysis of five representative isolates confirmed that they form a coherent group within Neorhizobium, closer to N. galegae than to the remaining Neorhizobium species, but clearly differentiated from the former, and constituting at least one new genomospecies within Neorhizobium. All the isolates lacked nod and nif symbiotic genes but contained a repABC replication/maintenance region, characteristic of rhizobial plasmids, within large contigs from their draft genome sequences. These repABC sequences were related, but not identical, to repABC sequences found in symbiotic plasmids from N. galegae, suggesting that the non-symbiotic isolates have the potential to harbor symbiotic plasmids. This is the first report of non-symbiotic members of Neorhizobium from soil.

Symbiotic polydnavirus and venom reveal parasitoid to its hyperparasitoids.

Science.gov (United States)

Zhu, Feng; Cusumano, Antonino; Bloem, Janneke; Weldegergis, Berhane T; Villela, Alexandre; Fatouros, Nina E; van Loon, Joop J A; Dicke, Marcel; Harvey, Jeffrey A; Vogel, Heiko; Poelman, Erik H

2018-05-15

Symbiotic relationships may provide organisms with key innovations that aid in the establishment of new niches. For example, during oviposition, some species of parasitoid wasps, whose larvae develop inside the bodies of other insects, inject polydnaviruses into their hosts. These symbiotic viruses disrupt host immune responses, allowing the parasitoid's progeny to survive. Here we show that symbiotic polydnaviruses also have a downside to the parasitoid's progeny by initiating a multitrophic chain of interactions that reveals the parasitoid larvae to their enemies. These enemies are hyperparasitoids that use the parasitoid progeny as host for their own offspring. We found that the virus and venom injected by the parasitoid during oviposition, but not the parasitoid progeny itself, affected hyperparasitoid attraction toward plant volatiles induced by feeding of parasitized caterpillars. We identified activity of virus-related genes in the caterpillar salivary gland. Moreover, the virus affected the activity of elicitors of salivary origin that induce plant responses to caterpillar feeding. The changes in caterpillar saliva were critical in inducing plant volatiles that are used by hyperparasitoids to locate parasitized caterpillars. Our results show that symbiotic organisms may be key drivers of multitrophic ecological interactions. We anticipate that this phenomenon is widespread in nature, because of the abundance of symbiotic microorganisms across trophic levels in ecological communities. Their role should be more prominently integrated in community ecology to understand organization of natural and managed ecosystems, as well as adaptations of individual organisms that are part of these communities.

Cost-Benefit Comparison of Two Proposed Overseas Programs for Reducing Chronic Hepatitis B Infection among Refugees: Is Screening Essential?

Science.gov (United States)

Jazwa, Amelia; Coleman, Margaret S.; Gazmararian, Julie; Wingate, La’Marcus T.; Maskery, Brian; Mitchell, Tarissa; Weinberg, Michelle

2015-01-01

Background Refugees are at an increased risk of chronic Hepatitis B Virus (HBV) infection because many of their countries of origin, as well as host countries, have intermediate-to-high prevalence rates. Refugees arriving to the US are also at risk of serious sequelae from chronic HBV infection because they are not routinely screened for the virus overseas or in domestic post-arrival exams, and may live in the US for years without awareness of their infection status. Methods A cohort of 26,548 refugees who arrived in Minnesota and Georgia during 2005–2010 was evaluated to determine the prevalence of chronic HBV infection. This prevalence information was then used in a cost-benefit analysis comparing two variations of a proposed overseas program to prevent or ameliorate the effects of HBV infection, titled ‘Screen, then vaccinate or initiate management’ (SVIM) and ‘Vaccinate only’ (VO). The analyses were performed in 2013. All values were converted to US 2012 dollars. Results The estimated six year period-prevalence of chronic HBV infection was 6.8% in the overall refugee population arriving to Minnesota and Georgia and 7.1% in those ≥ 6 years of age. The SVIM program variation was more cost beneficial than VO. While the up-front costs of SVIM were higher than VO ($154,084 vs. $73,758; n=58,538 refugees), the SVIM proposal displayed a positive net benefit, ranging from $24 million to $130 million after only 5 years since program initiation, depending on domestic post-arrival screening rates in the VO proposal. Conclusions Chronic HBV infection remains an important health problem in refugees resettling to the United States. An overseas screening policy for chronic HBV infection is more cost-beneficial than a ‘Vaccination only’ policy. The major benefit drivers for the screening policy are earlier medical management of chronic HBV infection and averted lost societal contributions from premature death. PMID:25595868

Cost-benefit comparison of two proposed overseas programs for reducing chronic Hepatitis B infection among refugees: is screening essential?

Science.gov (United States)

Jazwa, Amelia; Coleman, Margaret S; Gazmararian, Julie; Wingate, La'Marcus T; Maskery, Brian; Mitchell, Tarissa; Weinberg, Michelle

2015-03-10

Refugees are at an increased risk of chronic Hepatitis B virus (HBV) infection because many of their countries of origin, as well as host countries, have intermediate-to-high prevalence rates. Refugees arriving to the US are also at risk of serious sequelae from chronic HBV infection because they are not routinely screened for the virus overseas or in domestic post-arrival exams, and may live in the US for years without awareness of their infection status. A cohort of 26,548 refugees who arrived in Minnesota and Georgia during 2005-2010 was evaluated to determine the prevalence of chronic HBV infection. This prevalence information was then used in a cost-benefit analysis comparing two variations of a proposed overseas program to prevent or ameliorate the effects of HBV infection, titled 'Screen, then vaccinate or initiate management' (SVIM) and 'Vaccinate only' (VO). The analyses were performed in 2013. All values were converted to US 2012 dollars. The estimated six year period-prevalence of chronic HBV infection was 6.8% in the overall refugee population arriving to Minnesota and Georgia and 7.1% in those ≥6 years of age. The SVIM program variation was more cost beneficial than VO. While the up-front costs of SVIM were higher than VO ($154,084 vs. $73,758; n=58,538 refugees), the SVIM proposal displayed a positive net benefit, ranging from $24 million to $130 million after only 5 years since program initiation, depending on domestic post-arrival screening rates in the VO proposal. Chronic HBV infection remains an important health problem in refugees resettling to the United States. An overseas screening policy for chronic HBV infection is more cost-beneficial than a 'Vaccination only' policy. The major benefit drivers for the screening policy are earlier medical management of chronic HBV infection and averted lost societal contributions from premature death. Published by Elsevier Ltd.

Human papillomavirus infection among Bangladeshi women with cervical intraepithelial neoplasia and chronic cervicitis

Directory of Open Access Journals (Sweden)

Elisha Khandker

2016-01-01

Full Text Available Background and objectives: Cervical cancer is one of the leading causes of morbidity and mortality. Human papillomavirus (HPV is known to be associated with cervical intraepithelial neoplasia (CIN and cancer. The objective of the present study was to determine the rate of HPV infection among the Bangladeshi women with different grades of CIN and cancer. Methods: Women aged 20 to 55 years, diagnosed as a case of chronic cervicits, cervical intraepithelial neoplasia (CIN or invasive cancer by Papanicolaou (Pap smear and colposcopy directed biopsy were enrolled in the study. High and intermediate risk oncogenic HPV were detected in cervical samples by real time PCR (rt-PCR. Results: Seventy two women with chronic cervicitis and different grades of CIN were included in the study. Out of 72 cases, 28 (38.9% and 44 (61.1% had chronic cervicitis and CIN respectively. Overall, the HPV infection rate was 43.1% (95% CI= 32%-54% among the study population. CIN cases had significantly high (p<0.01 HPV infection (78.6%; 95% CI=60%-89% compared to cases with chronic cervicitis (18.2%; 95% CI=11.1%-34.5%. Women between the age of 20-30 years had the highest positive rate (50.0% followed by 31-40 years age group (43.6%. All CIN grade 2 and 3 had HPV infection. Conclusion: The study showed that HPV was strongly associated with different grades of CIN. Specific HPV types should be determined to find out the most prevalent HPV types among the Bangladeshi women with CIN and cervical cancers. IMC J Med Sci 2016; 10(1: 29-32

Screening of blood donors for chronic Coxiella burnetii infection after large Q fever outbreaks

NARCIS (Netherlands)

Slot, Ed; Hogema, Boris M.; Molier, Michel; Zaaijer, Hans L.

2014-01-01

The Netherlands experienced major Q fever outbreaks from 2007 through 2009. An increasing number of human chronic Q fever cases has been reported in the affected area. Blood donors unaware of chronic Coxiella burnetii infection might be infectious for transfusion recipients. Local blood donations

Phylogeny of nodulation genes and symbiotic diversity of Acacia senegal (L.) Willd. and A. seyal (Del.) Mesorhizobium strains from different regions of Senegal.

Science.gov (United States)

Bakhoum, Niokhor; Galiana, Antoine; Le Roux, Christine; Kane, Aboubacry; Duponnois, Robin; Ndoye, Fatou; Fall, Dioumacor; Noba, Kandioura; Sylla, Samba Ndao; Diouf, Diégane

2015-04-01

Acacia senegal and Acacia seyal are small, deciduous legume trees, most highly valued for nitrogen fixation and for the production of gum arabic, a commodity of international trade since ancient times. Symbiotic nitrogen fixation by legumes represents the main natural input of atmospheric N2 into ecosystems which may ultimately benefit all organisms. We analyzed the nod and nif symbiotic genes and symbiotic properties of root-nodulating bacteria isolated from A. senegal and A. seyal in Senegal. The symbiotic genes of rhizobial strains from the two Acacia species were closed to those of Mesorhizobium plurifarium and grouped separately in the phylogenetic trees. Phylogeny of rhizobial nitrogen fixation gene nifH was similar to those of nodulation genes (nodA and nodC). All A. senegal rhizobial strains showed identical nodA, nodC, and nifH gene sequences. By contrast, A. seyal rhizobial strains exhibited different symbiotic gene sequences. Efficiency tests demonstrated that inoculation of both Acacia species significantly affected nodulation, total dry weight, acetylene reduction activity (ARA), and specific acetylene reduction activity (SARA) of plants. However, these cross-inoculation tests did not show any specificity of Mesorhizobium strains toward a given Acacia host species in terms of infectivity and efficiency as stated by principal component analysis (PCA). This study demonstrates that large-scale inoculation of A. senegal and A. seyal in the framework of reafforestation programs requires a preliminary step of rhizobial strain selection for both Acacia species.

Radio emission from symbiotic variables: CI Cygni, Z Andromedae, and EG Andromedae - Temporal variability as clues to the nature of symbiotics

International Nuclear Information System (INIS)

Torbett, M.V.; Campbell, B.

1989-01-01

A continuing survey of interacting binary systems has yielded first detections of the symbiotic variables CI Cyg and EG And and reproduced previous flux measurements for Z And. The CI Cyg observation implies considerable radio variability for some symbiotics, while the radio flux from Z And indicates this object has been reasonably stable in the radio for years. Rapid radio variability may indicate the presence of mass transfer through an accretion disk. 27 refs

Comparative energetics of three fusion-fission symbiotic nuclear reactor systems

International Nuclear Information System (INIS)

Gordon, C.W.; Harms, A.A.

1975-01-01

The energetics of three symbiotic fusion-fission nuclear reactor concepts are investigated. The fuel and power balances are considered for various values of systems parameters. The results from this analysis suggest that symbiotic fusion-fission systems are advantageous from the standpoint of economy and resource utilization. (Auth.)

Request for regular monitoring of the symbiotic variable RT Cru

Science.gov (United States)

Waagen, Elizabeth O.

2014-08-01

Dr. Margarita Karovska (Harvard-Smithsonian Center for Astrophysics) and colleagues have requested AAVSO observer assistance in their campaign on the symbiotic variable RT Cru (member of a new class of hard X-ray emitting symbiotic binaries). Weekly or more frequent monitoring (B, V, and visual) beginning now is requested in support of upcoming Chandra observations still to be scheduled. "We plan Chandra observations of RT Cru in the near future that will help us understand the characteristics of the accretion onto the white dwarf in this sub-class of symbiotics. This is an important step for determining the precursor conditions for formation of a fraction of asymmetric Planetary Nebulae, and the potential of symbiotic systems as progenitors of at least a fraction of Type Ia supernovae." Finder charts with sequence may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details and observations.

Origin and evolutionary stage of symbiotic stars

Energy Technology Data Exchange (ETDEWEB)

Tutukov, A V; Yungel' son, L R [AN SSSR, Moscow. Astronomicheskij Sovet

1976-08-01

Symbiotic stars are considered which best of all are described by the binary star model. An analysis of properties of symbiotic stars shows that their hot components should be either carbon-oxygen dwarfs with thin hydrogen-helium envelopes or helium stars with thin mantles. Cold components are red giants losing matter at the rate of 10/sup -5/-10/sup -6/ M/yr over the period of 10/sup 5/-10/sup 6/ years (M is the Sun mass). Such systems can be formed of wide pairs as a result of loss of envelope of an initially more massive star of the system by way of continuous outflow of matter or expulsion due to dynamic instability at the red giant stage,, and also of closer pairs as a result of exchange of matter between the components. It has been shown that hot components of symbiotic stars can accrete 10/sup -6/-10/sup -9/ M/yr, and some consequencies of accretion on a C-O dwarf have been considered.

Comparative symbiotic plasmid analysis indicates that symbiosis gene ancestor type affects plasmid genetic evolution.

Science.gov (United States)

Wang, X; Zhao, L; Zhang, L; Wu, Y; Chou, M; Wei, G

2018-07-01

Rhizobial symbiotic plasmids play vital roles in mutualistic symbiosis with legume plants by executing the functions of nodulation and nitrogen fixation. To explore the gene composition and genetic constitution of rhizobial symbiotic plasmids, comparison analyses of 24 rhizobial symbiotic plasmids derived from four rhizobial genera was carried out. Results illustrated that rhizobial symbiotic plasmids had higher proportion of functional genes participating in amino acid transport and metabolism, replication; recombination and repair; carbohydrate transport and metabolism; energy production and conversion and transcription. Mesorhizobium amorphae CCNWGS0123 symbiotic plasmid - pM0123d had similar gene composition with pR899b and pSNGR234a. All symbiotic plasmids shared 13 orthologous genes, including five nod and eight nif/fix genes which participate in the rhizobia-legume symbiosis process. These plasmids contained nod genes from four ancestors and fix genes from six ancestors. The ancestral type of pM0123d nod genes was similar with that of Rhizobium etli plasmids, while the ancestral type of pM0123d fix genes was same as that of pM7653Rb. The phylogenetic trees constructed based on nodCIJ and fixABC displayed different topological structures mainly due to nodCIJ and fixABC ancestral type discordance. The study presents valuable insights into mosaic structures and the evolution of rhizobial symbiotic plasmids. This study compared 24 rhizobial symbiotic plasmids that included four genera and 11 species, illuminating the functional gene composition and symbiosis gene ancestor types of symbiotic plasmids from higher taxonomy. It provides valuable insights into mosaic structures and the evolution of symbiotic plasmids. © 2018 The Society for Applied Microbiology.

The Search for Symbiotic Stars in the IPHAS Survey

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Corradi R. L. M.

2012-06-01

Full Text Available We have started a project to search for symbiotic stars using the data from IPHAS, the Hα survey of the Northern Galactic plane. Candidates are selected from the IPHAS photometric catalogue based on their colors, combined with the information in the near-infrared from 2MASS. So far, follow-up spectroscopy allowed us to discover 14 new symbiotic stars, compared to the 10 systems previously known in the IPHAS survey area. Their general characteristics and the most notable cases are briefly presented. the spectroscopic campaign also allowed us to refine the selection criteria for symbiotic stars in IPHAS. Perspectives, which include the extension of the survey in the Southern Galactic plane and a portion of the bulge (VPHAS+, are discussed.

Phyllanthus species versus antiviral drugs for chronic hepatitis B virus infection

DEFF Research Database (Denmark)

Yun, Xia; Luo, Hui; Liu, Jian Ping

2013-01-01

Phyllanthus species for patients with chronic hepatitis B virus (HBV) infection have been assessed in clinical trials, but no consensus regarding their usefulness exists. When compared with placebo or no intervention, we were unable to identify convincing evidence that phyllanthus species...

Drug-Driven Phenotypic Convergence Supports Rational Treatment Strategies of Chronic Infections

DEFF Research Database (Denmark)

Imamovic, Lejla; Ellabaan, Mostafa Mostafa Hashim; Dantas Machado, Ana Manuel

2018-01-01

Chronic Pseudomonas aeruginosa infections evade antibiotic therapy and are associated with mortality in cystic fibrosis (CF) patients. We find that in vitro resistance evolution of P. aeruginosa toward clinically relevant antibiotics leads to phenotypic convergence toward distinct states. These s...

Formation of broad Balmer wings in symbiotic stars

International Nuclear Information System (INIS)

Chang, Seok-Jun; Heo, Jeong-Eun; Hong, Chae-Lin; Lee, Hee-Won

2016-01-01

Symbiotic stars are binary systems composed of a hot white dwarf and a mass losing giant. In addition to many prominent emission lines symbiotic stars exhibit Raman scattered O VI features at 6825 and 7088 Å. Another notable feature present in the spectra of many symbiotics is the broad wings around Balmer lines. Astrophysical mechanisms that can produce broad wings include Thomson scattering by free electrons and Raman scattering of Ly,β and higher series by neutral hydrogen. In this poster presentation we produce broad wings around Hα and H,β adopting a Monte Carlo techinique in order to make a quantitative comparison of these two mechanisms. Thomson wings are characterized by the exponential cutoff given by the termal width whereas the Raman wings are dependent on the column density and continuum shape in the far UV region. A brief discussion is provided. (paper)

Immunovirological analyses of chronically simian immunodeficiency virus SIVmnd-1- and SIVmnd-2-infected mandrills (Mandrillus sphinx).

Science.gov (United States)

Apetrei, Cristian; Sumpter, Beth; Souquiere, Sandrine; Chahroudi, Ann; Makuwa, Maria; Reed, Patricia; Ribeiro, Ruy M; Pandrea, Ivona; Roques, Pierre; Silvestri, Guido

2011-12-01

Simian immunodeficiency virus (SIV) infection in African nonhuman primate (NHP) natural hosts is usually nonpathogenic, despite high levels of virus replication. We have previously shown that chronic SIV infection in sooty mangabeys (SMs) and African green monkeys (AGMs) is associated with low levels of immune activation and bystander T cell apoptosis. To compare these features with those observed in another natural host, the mandrill (MND), we conducted a cross-sectional survey of the 23 SIV-infected and 25 uninfected MNDs from the only semifree colony of mandrills available worldwide. Viral loads (VLs) were determined and phenotypic and functional analysis of peripheral blood- and lymph node-derived lymphocytes was performed. We found that mandrills chronically infected with SIVmnd-1 or SIVmnd-2 have similar levels of viral replication, and we observed a trend toward lower CD4+ T cell counts in chronically SIVmnd-2-infected MNDs than SIVmnd-1-infected MNDs. No correlation between CD4+ T cell counts and VLs in SIV-infected MNDs could be established. Of note, the levels of T cell activation, proliferation, and apoptosis were comparable between SIVmnd-1- and SIVmnd-2-infected MNDs and to those observed in uninfected animals, with the only exception being an increase in tumor necrosis factor alpha-producing CD8+ T cells in SIVmnd-2-infected MNDs. Overall, these findings recapitulate previous observations in SIV-infected SMs and AGMs and lend further evidence to the hypothesis that low levels of immune activation protect natural SIV hosts from disease progression.

Clinical and morphological characteristics of chronic uretheroprostatitis associated with chlamydial and mycoplasmal infections

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Yu. S. Kondratyeva

2012-01-01

Full Text Available The purpose of this study was to investigate the clinical symptoms, features of morphological structure of prostate in patients with chronic recurrent prostatitis associated with chlamydial and mycoplasmal infections. 60 male patients were examined. Anamnesis and interview data, results of laboratory and instrumental tests were analyzed. In 73.3% of cases cultural test and PCR allowed to identify M. hominis, U. urealiticum, M. genitalium, C. trachomatis in patients with chronic uretheroprostatitis. Out of 16 patients (26,6% of all examined with chronic recurrent uretheroprostatitis for whom neither chlamidial nor mycoplasmal infection was diagnosed by laboratory tests, for 14 patients (87,5% it was confirmed that patogenic urogenital infectious agents were localized intracellularly. Pathomorphological investigation of prostate bioptates allowed to estimate the type and degree of specific changes in the prostate tissue in cases of recurrent uretheroprostatitis resistant to the therapy and with frequent relapses.

Effect of chronic hepatitis C virus infection on bone disease in postmenopausal women.

LENUS (Irish Health Repository)

Nanda, Kavinderjit S

2012-02-01

BACKGROUND & AIMS: Limited data are available on the contribution of chronic HCV infection to the development of bone disease in postmenopausal women. We studied whether women who acquired HCV infection through administration of HCV genotype 1b-contaminated anti-D immunoglobulin from a single source had decreased bone mineral density (BMD) or altered levels of bone turnover markers (BTMs), compared with women who spontaneously resolved infection or age-matched healthy controls. METHODS: From a cohort of postmenopausal Irish women, we compared BMD, determined by dual-energy x-ray absorptiometry, and a panel of BTMs in 20 women chronically infected with HCV (PCR(+)), 21 women who had spontaneously resolved infection (PCR(-)), and 23 age-matched healthy controls. RESULTS: Levels of BTMs and BMD were similar in PCR(+) and PCR(-) women and healthy age-matched controls. However, there was an increased frequency of fractures in PCR(+) (n = 6) compared with PCR(-) women (n = 0, P = .007). PCR(+) women with fractures were postmenopausal for a longer time (median, 15.5, range, 5-20 years vs 4.5, range, 1-20 years in PCR(+) women without fractures; P = .033), had lower BMD at the hip (0.79, range, 0.77-0.9 g\\/cm(2) vs 0.96, range, 0.81-1.10 g\\/cm(2); P = .007), and had a lower body mass index (23.7, range 21.2-28.5 kg\\/m(2) vs 25.6, range 22.1-36.6 kg\\/m(2); P = .035). There was no difference in liver disease severity or BTMs in PCR(+) women with or without fractures. CONCLUSIONS: Chronic HCV infection did not lead to discernable metabolic bone disease in postmenopausal women, but it might be a risk factor for bone fractures, so preventive measures should be introduced. To view this article\\'s video abstract, go to the AGA\\'s YouTube Channel.

Diversity, Roles, and Biotechnological Applications of Symbiotic Microorganisms in the Gut of Termite.

Science.gov (United States)

Zhou, Jing; Duan, Jiwei; Gao, Mingkun; Wang, Ying; Wang, Xiaohua; Zhao, Kai

2018-05-12

Termites are global pests and can cause serious damage to buildings, crops, and plantation forests. The symbiotic intestinal flora plays an important role in the digestion of cellulose and nitrogen in the life of termites. Termites and their symbiotic microbes in the gut form a synergistic system. These organism work together to digest lignocellulose to make the termites grow on nitrogen deficient food. In this paper, the diversity of symbiotic microorganisms in the gut of termites, including protozoan, spirochetes, actinomycetes, fungus and bacteria, and their role in the digestion of lignocellulose and also the biotechnological applications of these symbiotic microorganisms are discussed. The high efficiency lignocellulose degradation systems of symbiotic microbes in termite gut not only provided a new way of biological energy development, but also has immense prospect in the application of cellulase enzymes. In addition, the study on the symbiotic microorganisms in the gut of termites will also provide a new method for the biological control of termites by the endophytic bacteria in the gut of termites.

Chronic Chlamydia pneumoniae infection and bronchial asthma: Is there a link?

Directory of Open Access Journals (Sweden)

Agarwal A

2008-01-01

Full Text Available Purpose: Besides well-defined environmental causes, accumulating evidence suggests that respiratory tract infections play an important role in the pathogenesis of asthma. Among these Chlamydia pneumoniae infection has been discussed as possibly inducing the development of asthma. Methods: This study was designed to investigate the presence of anti chlamydial IgG, IgA, and IgM antibodies by ELISA in serum samples of 60 adults with a clinical history of asthma and 100 healthy age and sex matched controls. All the samples positive for Chlamydial genus specific IgG antibodies were then subjected to Chlamydia pneumoniae species specific IgG antibody ELISA. Results: The IgG anti chlamydial antibody-positivity rate in the patients with bronchial asthma (80% was significantly higher in all age groups than that in the healthy age and sex matched controls (59%. No significant association was observed for IgA and IgM anti chlamydial antibodies. C. pneumoniae species specific IgG antibody seroprevalence was also found to be significantly higher in all age groups in comparison to controls (61.66% vs 38%. Conclusions: Serological evidence of chronic infection with C. pneumoniae was more frequent in patients with asthma compared with control subjects. Our results support the correlation of bronchial asthma and chronic infection with C. pneumoniae in Indian population.

Radio molecular maser line study of symbiotic stars

International Nuclear Information System (INIS)

Cohen, N.L.; Ghigo, F.D.

1980-01-01

A sample of symbiotic stars has been searched for maser emission from the 1665- and 1667-MHz OH mainlines, the 22-GHz H 2 O line, and the 43-GHz SiO line. R Aqr remains the sole symbiotic for which maser emission has been detected. Its SiO spectrum reveals a pedestal of emission with a narrow superposed peak at V/sub LSR/ -26.4 +- 0.7 km/s. The line's existence and the pedestal feature are both characteristic of SiO lines found in late-type variables by Snyder et al. [Astrophys. J. 224, 512 (1978)]. For the other symbiotic stars, it is possible that conditions favorable for maser emission have been suppressed by the presence of a hot companion. Alternatively our findings may argue against the presence of late-type variables in symbiotic stars. In either case, R Aqr seems to be in a class by itself. We cannot confirm the suggestion that R Aqr is a binary, since the spectral feature has not shifted noticeably in the two years since the observations by Lepine, LeSqueren, and Scalise [Astrophys. J. 225, 869 (1978)]. However, we point out that monitoring the pedestal emission over a number of years is the least ambiguous way to discern any velocity shift that might result from orbital motion

Bacteriophages encode factors required for protection in a symbiotic mutualism.

Science.gov (United States)

Oliver, Kerry M; Degnan, Patrick H; Hunter, Martha S; Moran, Nancy A

2009-08-21

Bacteriophages are known to carry key virulence factors for pathogenic bacteria, but their roles in symbiotic bacteria are less well understood. The heritable symbiont Hamiltonella defensa protects the aphid Acyrthosiphon pisum from attack by the parasitoid Aphidius ervi by killing developing wasp larvae. In a controlled genetic background, we show that a toxin-encoding bacteriophage is required to produce the protective phenotype. Phage loss occurs repeatedly in laboratory-held H. defensa-infected aphid clonal lines, resulting in increased susceptibility to parasitism in each instance. Our results show that these mobile genetic elements can endow a bacterial symbiont with benefits that extend to the animal host. Thus, phages vector ecologically important traits, such as defense against parasitoids, within and among symbiont and animal host lineages.

Innate and adaptive immune response to chronic pulmonary infection of hyphae of Aspergillus fumigatus in a new murine model.

Science.gov (United States)

Wang, Fengyuan; Zhang, Caiyun; Jiang, Yuan; Kou, Caixia; Kong, Qingtao; Long, Nanbiao; Lu, Ling; Sang, Hong

2017-10-01

The pathogenesis of chronic pulmonary aspergillosis (CPA) has seldom been studied due partly to a lack of animal models. Since hypha is the main morphology colonizing the airway in CPA, it's critical to study the immune reaction to chronic pulmonary infection of hyphae of Aspergillus fumigatus, which also has seldom been studied in vivo before. We established a novel murine model of chronic pulmonary infection of hyphae by challenging immunocompetent mice with tightly-structured hyphae balls intratracheally, and described the ensuing immunoreaction to hyphae and conidia, and the pathogenesis of CPA. Our experiment proved that the hyphae balls could induce a chronic pulmonary infection for 28 days with a considerable recrudescence at day 28 post-infection. Lungs infected with hyphae balls were remarkable for the many neutrophils and macrophages that flooded into airway lumens, with peribronchiolar infiltration of leukocytes. There was a transient increase of Th2 cells and Th17 cells at day 7 post-infection in the lung tissue. In contrast, lungs infected with conidia showed no peribronchiolar infiltration of leukocytes, but an influx of a great number of macrophages, and a much less number of neutrophils in the lumen. Besides, conidia activated the co-response of Th1, Th2 and Th17 cells with an increase of Treg cells in the lung tissue (quite different from most previous studies). We established a new murine model of chronic infection of hyphae to mimic the formation of CPA, and provide a new marker for different immune responses to hyphae and conidia.

Sperm Morphological Features Associated with Chronic Chagas Disease in the Semen of Experimentally Infected Dogs

Science.gov (United States)

Rodríguez-Morales, Olivia; Pedro-Martínez, Elvia; Hernández-Pichardo, José Ernesto; Alejandre-Aguilar, Ricardo; Aranda-Fraustro, Alberto; Graullera-Rivera, Verónica; Arce-Fonseca, Minerva

2014-01-01

The presence of trypanosomatids in the reproductive systems of different mammals (causing genital lesions in the acute stage of the disease) may predispose the animals to low semen quality. However, there are no studies examining the alterations in the sperm morphological features in the chronic stage of Trypanosoma cruzi infection. Knowledge of these aspects is important to understand the other ways of transmission of the Chagas disease. Progressive motility, mass motility, concentration, and sperm morphology of 84 ejaculates of dogs that were chronically infected with T. cruzi were evaluated. Most of the findings were consistent with the reference values and with those obtained from healthy control dogs. The scrotal circumference was not correlated with spermatozoa concentration in the infected animals. In conclusion, the T. cruzi Ninoa (MHOM/MX/1994/Ninoa) strain does not cause significant alterations in the semen quality of dogs experiencing chronic Chagas disease (at concentrations of 5 × 104 to 1 × 106 parasites per animal). PMID:25114010

A DISCUSSION ON THE CLASSIFICATION AND EVOLUTION OF SYMBIOTIC STARS

NARCIS (Netherlands)

SEAL, P

1990-01-01

A H-R diagram is drawn from the bolometric luminosities and effective temperatures of 24 symbiotic stars and compared with theoretical evolutionary tracks of Population I metal-rich stars. It is shown that the S-type and D-type symbiotic stars are classified very clearly in course of their evolution

Irritable bowel syndrome and chronic fatigue 6 years after giardia infection: a controlled prospective cohort study.

Science.gov (United States)

Hanevik, Kurt; Wensaas, Knut-Arne; Rortveit, Guri; Eide, Geir Egil; Mørch, Kristine; Langeland, Nina

2014-11-15

Functional gastrointestinal disorders and fatigue may follow acute infections. This study aimed to estimate the persistence, prevalence, and risk of irritable bowel syndrome and chronic fatigue 6 years after Giardia infection. We performed a controlled prospective study of a cohort of 1252 individuals who had laboratory-confirmed Giardia infection during a waterborne outbreak in 2004. In total, 748 cohort cases (exposed) and 878 matched controls responded to a postal questionnaire 6 years later (in 2010). Responses were compared to data from the same cohort 3 years before (in 2007). The prevalences of irritable bowel syndrome (39.4%) by Rome III criteria and chronic fatigue (30.8%) in the exposed group 6 years after giardiasis were significantly elevated compared with controls, with adjusted relative risks (RRs) of 3.4 (95% confidence interval [CI], 2.9-3.9) and 2.9 (95% CI, 2.3-3.4), respectively. In the exposed group, the prevalence of irritable bowel syndrome decreased by 6.7% (RR, 0.85 [95% CI, .77-.93]), whereas the prevalence of chronic fatigue decreased by 15.3% from 3 to 6 years after Giardia infection (RR, 0.69 [95% CI, .62-.77]). Giardia exposure was a significant risk factor for persistence of both conditions, and increasing age was a risk factor for persisting chronic fatigue. Giardia infection in a nonendemic setting is associated with an increased risk for irritable bowel syndrome and chronic fatigue 6 years later. The prevalences of both conditions decrease over time, indicating that this intestinal protozoan parasite may elicit very long-term, but slowly self-limiting, complications. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America.

Persistent Coxiella burnetii infection in mice overexpressing IL-10: an efficient model for chronic Q fever pathogenesis.

Directory of Open Access Journals (Sweden)

Soraya Meghari

2008-02-01

Full Text Available Interleukin (IL-10 increases host susceptibility to microorganisms and is involved in intracellular persistence of bacterial pathogens. IL-10 is associated with chronic Q fever, an infectious disease due to the intracellular bacterium Coxiella burnetii. Nevertheless, accurate animal models of chronic C. burnetii infection are lacking. Transgenic mice constitutively expressing IL-10 in macrophages were infected with C. burnetti by intraperitoneal and intratracheal routes and infection was analyzed through real-time PCR and antibody production. Transgenic mice exhibited sustained tissue infection and strong antibody response in contrast to wild-type mice; thus, bacterial persistence was IL-10-dependent as in chronic Q fever. The number of granulomas was low in spleen and liver of transgenic mice infected through the intraperitoneal route, as in patients with chronic Q fever. Macrophages from transgenic mice were unable to kill C. burnetii. C. burnetii-stimulated macrophages were characterized by non-microbicidal transcriptional program consisting of increased expression of arginase-1, mannose receptor, and Ym1/2, in contrast to wild-type macrophages in which expression of inducible NO synthase and inflammatory cytokines was increased. In vivo results emphasized macrophage data. In spleen and liver of transgenic mice infected with C. burnetii by the intraperitoneal route, the expression of arginase-1 was increased while microbicidal pathway consisting of IL-12p40, IL-23p19, and inducible NO synthase was depressed. The overexpression of IL-10 in macrophages prevents anti-infectious competence of host, including the ability to mount granulomatous response and microbicidal pathway in tissues. To our knowledge, this is the first efficient model for chronic Q fever pathogenesis.

The Relationship between Chronic Constipation and Urinary Tract Infection in Children: A Case-Control Clinical Study

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Gholamreza Sarvari

2017-09-01

Full Text Available Background Urinary tract infection (UTI is one of the most common bacterial infections in children, if not diagnosed leads to serious complications such as hypertension, chronic renal failure and renal scar. Constipation is one of the main risk factors for recurrent UTI. The aim of present study was to investigate the relationship between chronic constipation and urinary tract infection in children. Materials and Methods In this case-control study 105 patients with functional chronic constipation as case group, compared with 104 children without chronic constipation as control. The control group was matched according to gender and age. The prevalence of UTI in children with and without constipation as well as their improvement was compared after treatment. Results The prevalence of UTI in case and control groups was 13.3% and 6.7%, respectively (P=0.17. The prevalence of UTI in case group decreased to 3.8% after treatment of constipation. Escherichia coli (E coli was the most commonly isolated organism in both groups. Conclusion Results of present study showed that despite of no significant urinary tract infection incidence between children with constipation and those without constipation, the constipation should still be considered as a predisposing risk factor for the UTI occurrence.

The 2012 revised Dutch national guidelines for the treatment of chronic hepatitis B virus infection

NARCIS (Netherlands)

Buster, E. H. C. J.; Baak, B. C.; Bakker, C. M.; Beuers, U. H. W.; Brouwer, J. T.; Drenth, J. P. H.; van Erpecum, K. J.; van Hoek, B.; Honkoop, P.; Kerbert-Dreteler, M. J.; Koek, G. H.; van Nieuwkerk, K. M. J.; van Soest, H.; van der Spek, B. W.; Tan, A. C. I. T. L.; Vrolijk, J. M.; Janssen, H. L. A.

2012-01-01

In 2008, the Netherlands Association of Gastroenterologists and Hepatologists (Nederlands Vereniging van Maag-Darm-Leverartsen) published the Dutch national guidelines for the treatment of chronic hepatitis B virus infection. New insights into the treatment of chronic hepatitis B with relevance for

Exploring the potential of symbiotic fungal endophytes in cereal disease suppression

DEFF Research Database (Denmark)

O'Hanlon, Karen; Knorr, Kamilla; Jørgensen, Lise Nistrup

2012-01-01

, and environmental and health concerns surrounding the use of chemical treatments. There is currently a demand for new disease control strategies, and one such strategy involves the use of symbiotic fungal endophytes as biological control agents against fungal pathogens in cereals. Despite the fact that biological...... control by symbiotic fungal endophytes has been documented, particularly with respect to clavicipitaceous endophytes in C3 cool-season grasses, this area remains relatively underexplored in cereals. We highlight for the first time the potential in using symbiotic fungal endophytes to control foliar cereal...

Lung Metastases from Bile Duct Adenocarcinoma Mimicking Chronic Airway Infection and Causing Diagnostic Difficulty.

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Sato, Mitsuo; Okachi, Shotaro; Fukihara, Jun; Shimoyama, Yoshie; Wakahara, Keiko; Sakakibara, Toshihiro; Hase, Tetsunari; Onishi, Yasuharu; Ogura, Yasuhiro; Maeda, Osamu; Hasegawa, Yoshinori

2018-05-15

We herein report a case of lung metastases with unusual radiological appearances that mimicked those of chronic airway infection, causing diagnostic difficulty. A 60-year-old woman who underwent liver transplantation from a living donor was incidentally diagnosed with bile duct adenocarcinoma after a histopathological analysis of her explanted liver. Six months later, chest computed tomography (CT) revealed bilateral bronchogenic dissemination that had gradually worsened, suggesting chronic airway infection. A biopsy with bronchoscopy from a mass lesion beyond a segmental bronchus revealed adenocarcinoma identical to that of her bile duct adenocarcinoma, leading to the diagnosis of multiple lung metastases from bile duct adenocarcinoma.

Synovial Calprotectin: An Inexpensive Biomarker to Exclude a Chronic Prosthetic Joint Infection.

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Wouthuyzen-Bakker, Marjan; Ploegmakers, Joris J W; Ottink, Karsten; Kampinga, Greetje A; Wagenmakers-Huizenga, Lucie; Jutte, Paul C; Kobold, Anneke C M

2018-04-01

To diagnose or exclude a chronic prosthetic joint infection (PJI) can be a clinical challenge. Therefore, sensitive and specific biomarkers are needed in the diagnostic work-up. Calprotectin is a protein with antimicrobial properties and is released by activated neutrophils, making it a specific marker for infection. Because of its low costs and ability to obtain a quantitative value as a point of care test, it is an attractive marker to use in clinical practice. In addition, the test is already used in routine care in most hospitals for other indications and therefore easy to implement. Between June 2015 and June 2017 we collected synovial fluid of all consecutive patients who underwent revision surgery of a prosthetic joint because of chronic pain with or without prosthetic loosening. Synovial calprotectin was measured using a lateral flow immunoassay. A PJI was defined by the diagnostic criteria described by the Musculoskeletal Infection Society. Fifty-two patients with chronic pain were included. A PJI was diagnosed in 15 of 52 (29%) patients. The median calprotectin in the PJI group was 859 mg/L (interquartile range 86-1707) vs 7 mg/L (interquartile range 3-25) in the control group (P < .001). With a cut-off value of 50 mg/L, synovial calprotectin showed a sensitivity, specificity, positive predictive value, and negative predictive value of 86.7%, 91.7%, 81.3%, and 94.4%, respectively. Synovial calprotectin is a useful and cheap biomarker to use in the diagnostic work-up of patients with chronic pain, especially to exclude a PJI prior to revision surgery. Copyright © 2017 Elsevier Inc. All rights reserved.

Complementary and Alternative Medicine Use by Patients Chronically Infected with Hepatitis C Virus

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Colin P White

2007-01-01

Full Text Available Complementary and alternative medicine (CAM is becoming increasingly popular in North America. The use of CAM is also popular in patients with chronic liver disease but is not well documented. The extent of use of CAM in chronic hepatitis C virus (HCV infected patients was determined, and the demographic and clinical data between users and nonusers of CAM was compared.

Nontypeable Haemophilus influenzae biofilms: role in chronic airway infections

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W Edward Swords

2012-07-01

Full Text Available Like many pathogens inhabiting mucosal surfaces, nontypeable Haemophilus influenzae (NTHi forms multicellular biofilm communities both in vitro and in various infection models. In the past 15 years much has been learned about determinants of biofilm formation by this organism and potential roles in bacterial virulence, especially in the context of chronic and recurrent infections. However, this concept has not been without some degree of controversy, and in the past some have expressed doubts about the relevance of NTHi biofilms to disease. In this review, I will summarize the present information on the composition and potential role(s of NTHi biofilms in different clinical contexts, as well as highlight potential areas for future work.

Nontypeable Haemophilus influenzae biofilms: role in chronic airway infections.

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Swords, W Edward

2012-01-01

Like many pathogens inhabiting mucosal surfaces, nontypeable Haemophilus influenzae (NTHi) forms multicellular biofilm communities both in vitro and in various infection models. In the past 15 years much has been learned about determinants of biofilm formation by this organism and potential roles in bacterial virulence, especially in the context of chronic and recurrent infections. However, this concept has not been without some degree of controversy, and in the past some have expressed doubts about the relevance of NTHi biofilms to disease. In this review, I will summarize the present information on the composition and potential role(s) of NTHi biofilms in different clinical contexts, as well as highlight potential areas for future work.

Body size and symbiotic status influence gonad development in Aiptasia pallida anemones.

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Carlisle, Judith F; Murphy, Grant K; Roark, Alison M

2017-01-01

Pale anemones ( Aiptasia pallida ) coexist with dinoflagellates (primarily Symbiodinium minutum ) in a mutualistic relationship. The purpose of this study was to investigate the role of these symbionts in gonad development of anemone hosts. Symbiotic and aposymbiotic anemones were subjected to light cycles that induced gametogenesis. These anemones were then sampled weekly for nine weeks, and gonad development was analyzed histologically. Anemone size was measured as mean body column diameter, and oocytes or sperm follicles were counted for each anemone. Generalized linear models were used to evaluate the influence of body size and symbiotic status on whether gonads were present and on the number of oocytes or sperm follicles produced. Body size predicted whether gonads were present, with larger anemones being more likely than smaller anemones to develop gonads. Both body size and symbiotic status predicted gonad size, such that larger and symbiotic anemones produced more oocytes and sperm follicles than smaller and aposymbiotic anemones. Overall, only 22 % of aposymbiotic females produced oocytes, whereas 63 % of symbiotic females produced oocytes. Similarly, 6 % of aposymbiotic males produced sperm follicles, whereas 60 % of symbiotic males produced sperm follicles. Thus, while gonads were present in 62 % of symbiotic anemones, they were present in only 11 % of aposymbiotic anemones. These results indicate that dinoflagellate symbionts influence gonad development and thus sexual maturation in both female and male Aiptasia pallida anemones. This finding substantiates and expands our current understanding of the importance of symbionts in the development and physiology of cnidarian hosts.

Activated ClpP kills persisters and eradicates a chronic biofilm infection.

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Conlon, Brian P.; Nakayasu, Ernesto S.; Fleck, Laura E.; LaFleur, Michael D.; Isabella, Vincent M.; Coleman, K.; Leonard, Steve N.; Smith, Richard D.; Adkins, Joshua N.; Lewis, Kim

2013-11-21

The current antibiotic crisis stems from two distinct phenomena-drug resistance, and drug tolerance. Resistance mechanisms such as drug efflux or modification prevent antibiotics from binding to their targets 1, allowing pathogens to grow. Antibiotic tolerance is the property of persister cells, phenotypic variants of regular bacteria 2. Antibiotics kill by corrupting targets, but these are inactive in dormant persisters, leading to tolerance. Persisters were first identified by Joseph Bigger in 1944, when he discovered a surviving sub-population of Staphylococcus following treatment with penicillin3. Persisters are largely responsible for recalcitrance of chronic diseases such as tuberculosis, and various infections associated with biofilms - endocarditis, osteomyelitis, infections of catheters and indwelling devices, and deep-seated infections of soft tissues 4. There are a number of redundant pathways involved in persister formation5,6 precluding development of drugs inhibiting their formation. The acyldepsipeptide antibiotic (ADEP 4) has been shown to activate the ClpP protease resulting in death of growing cells 7. Here we show that ADEP4 activated ClpP becomes a fairly non-specific protease and kills persister cells by degradation of over 400 intracellular targets. clpP mutants are resistant to ADEP4 7, but we find that they display increased susceptibility to killing by a range of conventional antibiotics. Combining ADEP4 with rifampicin leads to eradication of persisters, stationary and biofilm populations of Staphylococcus aureus in vitro and in a deep-seated murine infection. Target corruption/activation provides an approach to killing persisters and eradicating chronic infections.

On origin and evolutionary stage of symbiotic stars

International Nuclear Information System (INIS)

Tutukov, A.V.; Yungel'son, L.R.

1976-01-01

Symbiotic stars are considered which best of all are described by the binary star model. An analysis of properties of symbiotic stars shows that their hot components should be either carbon-oxygen dwarfs with thin hydrogen-helium envelopes or helium stars with thin mantles. Cold components are red giants losing matter with the rate of 10 -5 -10 -6 M/yr over the period of 10 5 -10 6 years (M is the Sun mass). Such systems can be formed of wide pairs as a result of loss of envelope of an initially more massive star of the system by way of continuous outflow of matter or expulsion due to dynamic instability at the stage of red giant, and also of more close pairs as a result of exchange of matter between the components. It has been shown that hot components of symbiotic stars can accrete 10 -6 -10 -9 M/yr and some consequencies of accretion on a C-O dwarf have been considered

Sigma Factor SigB Is Crucial to Mediate Staphylococcus aureus Adaptation during Chronic Infections.

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Lorena Tuchscherr

2015-04-01

Full Text Available Staphylococcus aureus is a major human pathogen that causes a range of infections from acute invasive to chronic and difficult-to-treat. Infection strategies associated with persisting S. aureus infections are bacterial host cell invasion and the bacterial ability to dynamically change phenotypes from the aggressive wild-type to small colony variants (SCVs, which are adapted for intracellular long-term persistence. The underlying mechanisms of the bacterial switching and adaptation mechanisms appear to be very dynamic, but are largely unknown. Here, we analyzed the role and the crosstalk of the global S. aureus regulators agr, sarA and SigB by generating single, double and triple mutants, and testing them with proteome analysis and in different in vitro and in vivo infection models. We were able to demonstrate that SigB is the crucial factor for adaptation in chronic infections. During acute infection, the bacteria require the simultaneous action of the agr and sarA loci to defend against invading immune cells by causing inflammation and cytotoxicity and to escape from phagosomes in their host cells that enable them to settle an infection at high bacterial density. To persist intracellularly the bacteria subsequently need to silence agr and sarA. Indeed agr and sarA deletion mutants expressed a much lower number of virulence factors and could persist at high numbers intracellularly. SigB plays a crucial function to promote bacterial intracellular persistence. In fact, ΔsigB-mutants did not generate SCVs and were completely cleared by the host cells within a few days. In this study we identified SigB as an essential factor that enables the bacteria to switch from the highly aggressive phenotype that settles an acute infection to a silent SCV-phenotype that allows for long-term intracellular persistence. Consequently, the SigB-operon represents a possible target to develop preventive and therapeutic strategies against chronic and therapy

Sigma Factor SigB Is Crucial to Mediate Staphylococcus aureus Adaptation during Chronic Infections.

Science.gov (United States)

Tuchscherr, Lorena; Bischoff, Markus; Lattar, Santiago M; Noto Llana, Mariangeles; Pförtner, Henrike; Niemann, Silke; Geraci, Jennifer; Van de Vyver, Hélène; Fraunholz, Martin J; Cheung, Ambrose L; Herrmann, Mathias; Völker, Uwe; Sordelli, Daniel O; Peters, Georg; Löffler, Bettina

2015-04-01

Staphylococcus aureus is a major human pathogen that causes a range of infections from acute invasive to chronic and difficult-to-treat. Infection strategies associated with persisting S. aureus infections are bacterial host cell invasion and the bacterial ability to dynamically change phenotypes from the aggressive wild-type to small colony variants (SCVs), which are adapted for intracellular long-term persistence. The underlying mechanisms of the bacterial switching and adaptation mechanisms appear to be very dynamic, but are largely unknown. Here, we analyzed the role and the crosstalk of the global S. aureus regulators agr, sarA and SigB by generating single, double and triple mutants, and testing them with proteome analysis and in different in vitro and in vivo infection models. We were able to demonstrate that SigB is the crucial factor for adaptation in chronic infections. During acute infection, the bacteria require the simultaneous action of the agr and sarA loci to defend against invading immune cells by causing inflammation and cytotoxicity and to escape from phagosomes in their host cells that enable them to settle an infection at high bacterial density. To persist intracellularly the bacteria subsequently need to silence agr and sarA. Indeed agr and sarA deletion mutants expressed a much lower number of virulence factors and could persist at high numbers intracellularly. SigB plays a crucial function to promote bacterial intracellular persistence. In fact, ΔsigB-mutants did not generate SCVs and were completely cleared by the host cells within a few days. In this study we identified SigB as an essential factor that enables the bacteria to switch from the highly aggressive phenotype that settles an acute infection to a silent SCV-phenotype that allows for long-term intracellular persistence. Consequently, the SigB-operon represents a possible target to develop preventive and therapeutic strategies against chronic and therapy-refractory infections.

AGB stellar evolution and symbiotic stars

International Nuclear Information System (INIS)

Schild, H.

1989-01-01

Published data on the mass loss rates and periods of Miras and OH/IR stars have been compiled. There is a good correlation between mass loss rate and period and a smooth transition from Miras to OH/IR sources. At periods below 600 d. the mass loss increases exponentially but at longer periods it remains constant. As a Mira evolves from short to longer periods, its mass loss rate increases dramatically. Phenomenologically, the object evolves from a classical Mira into a variable OH/IR source. Symbiotic stars cluster in the transition zone where Miras transform into OH/IR stars and mass loss increase is at its steepest. The red star in these symbiotic systems is in the same evolutionary status as short periodic OH/IR stars. (author)

Chronic Subdural Hematoma Infected by Propionibacterium Acnes: A Case Report

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Yamamoto, Shusuke; Asahi, Takashi; Akioka, Naoki; Kashiwazaki, Daina; Kuwayama, Naoya; Kuroda, Satoshi

2015-01-01

We present a very rare case of a patient with an infected subdural hematoma due to Propionibacterium acnes. A 63-year-old male complained of dizziness and was admitted to our hospital. He had a history of left chronic subdural hematoma due to a traffic accident, which had been conservatively treated. Physical, neurological and laboratory examinations revealed no definite abnormality. Plain CT scan demonstrated a hypodense crescentic fluid collection over the surface of the left cerebral hemisphere. The patient was diagnosed with chronic subdural hematoma and underwent burr hole surgery three times and selective embolization of the middle meningeal artery, but the lesion easily recurred. Repeated culture examinations of white sedimentation detected P. acnes. Therefore, he underwent craniotomy surgery followed by intravenous administration of antibiotics. The infected subdural hematoma was covered with a thick, yellowish outer membrane, and the large volume of pus and hematoma was removed. However, the lesion recurred again and a low-density area developed in the left frontal lobe. Craniotomy surgery was performed a second time, and two Penrose drainages were put in both the epidural and subdural spaces. Subsequently, the lesions completely resolved and he was discharged without any neurological deficits. Infected subdural hematoma may be refractory to burr hole surgery or craniotomy alone, in which case aggressive treatment with craniotomy and continuous drainage should be indicated before the brain parenchyma suffers irreversible damage. PMID:25759659

Aromaphytobalneotherapy in Treatment and Prophylaxis of Frequent Respiratory Infections in Children with Chronic and Disabling Diseases

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O. M. Konova

2016-01-01

Full Text Available In children with chronic pathologies, co-occurring frequent respiratory infections of a prolonged course obstructs and reduce the effectiveness of rehabilitation measures, and adversely affect the adaptation reserves. Hydrotherapeutic factors are widely used for the prevention of colds in children from the first days of life. Addition to the water of medicinal and phytoaromatic preparations increases their efficiency. For patients with chronic pathology, when prescribing balneotherapeutic factors for treatment and prophylaxis of respiratory infections, it is important to take into account the potential risk of adverse effects on the symptoms of the underlying disease. Researches in patients with orthopedic, chronic gastroenterological diseases, spastic forms of cerebral palsy, with co-occurring frequent respiratory infections of a prolonged course in history revealed that addition of medicinal baths based on phytoaromatic preparation, containing eucalyptus oil, to the rehabilitation complex is an effective method of preventing and stopping initial symptoms of respiratory infections. It also contributes to the adaptation reserves of the organism, without adversely affecting the course of the underlying disease.

Dust around the Cool Component of D-Type Symbiotic Binaries

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Jurkic, Tomislav; Kotnik-Karuza, Dubravka

2018-04-01

D type symbiotic binaries are an excellent astrophysical laboratory for investigation of the dust properties and dust formation under the influence of theMira stellar wind and nova activity and of the mass loss and mass transfer between components in such a widely separated system. We present a study of the properties of circumstellar dust in symbiotic Miras by use of long-term near-IR photometry and colour indices. The published JHKL magnitudes of o Ceti, RX Pup, KM Vel, V366 Car, V835 Cen, RR Tel, HM Sge and R Aqr have been collected, analyzed and corrected for short-term variations caused by Mira pulsations. Assuming spherical temperature distribution of the dust in the close neighbourhood of the Mira, the DUSTY code was used to solve the radiative transfer in order to determine the dust temperature and its properties in each particular case. Common dust properties of the symbiotic Miras have been found, suggesting similar conditions in the condensation region of the studied symbiotic Miras. Silicate dust with the inner dust shell radius determined by the dust condensation and with the dust temperature of 900-1200 K can fully explain the observed colour indices. R Aqr is an exception and showed lower dust temperature of 650 K. Obscuration events visible in light curves can be explained by variable dust optical depth with minimal variations of other dust properties. More active symbioticMiras that underwent recent nova outbursts showed higher dust optical depths and larger maximum grain sizes of the order of μm, which means that the post-nova activity could stimulate the dust formation and the grain growth. Optically thicker dust shells and higher dust condensation temperatures have been found in symbiotic Miras compared to their single counterparts, suggesting different conditions for dust production.

Properties of symbiotic stars from studies in the optical region

International Nuclear Information System (INIS)

Ciatti, F.

1982-01-01

The author uses observations of symbiotic stars in the optical region to discuss the following aspects: definition, photometric and spectroscopic evolution, the three-component model, evidence for the binary nature, spectroscopic properties and anomalies, single-star interpretations, the ''very slow novae'' and BQ// stars and a comparison of symbiotic stars with other classes. (C.F.)

Chronic hepatitis E infection with an emerging virus strain in a heart transplant recipient successfully treated with ribavirin: a case report.

Science.gov (United States)

Waldenström, Jesper; Castedal, Maria; Konar, Jan; Karason, Kristjan; Lagging, Martin; Norder, Helene

2015-08-26

During the last decade hepatitis E infections have been recognized as a health problem in high-income countries, where hepatitis E virus genotype 3 is endemic. The infection is often self-limiting, but may develop into chronic infection in immunocompromised patients, especially in solid organ recipients. If these patients or patients with underlying liver disease get hepatitis E infection, they may develop liver failure and cirrhosis. Hepatitis E virus is occasionally found in blood products and transfusion transmission has been reported. We present the first case of chronic hepatitis E infection in a heart transplant recipient in Sweden. A 63-year-old Swedish white man presented with highly elevated liver enzymes 6 months after heart transplantation. Polymerase chain reaction revealed chronic hepatitis E infection, caused by a virus strain found infecting symptomatic cases in Sweden and other European countries. During transplantation, he received blood products from 17 donors, and transfusion transmission is highly likely. The only detectable marker for hepatitis E infection was hepatitis E virus ribonucleic acid for more than 2 months before anti-hepatitis E virus developed. He was treated successfully with ribavirin and decreased immunosuppression. Our patient was probably infected through contaminated blood products and subsequently developed chronic infection, which was cured upon treatment. This highlights the need for evaluating the problem with chronic hepatitis E infection in immunocompromised patients, and for discussion concerning screening of blood products. Polymerase chain reaction-based methods are recommended for diagnosing hepatitis E infection in patients with compromised immunity. In addition, knowledge needs to be gained on the infecting virus strain, which may be more virulent than other strains.

Vacuum-assisted closure versus closure without vacuum assistance for preventing surgical site infections and infections of chronic wounds: a meta-analysis of randomized controlled trials.

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Tansarli, Giannoula S; Vardakas, Konstantinos Z; Stratoulias, Constantinos; Peppas, George; Kapaskelis, Anastasios; Falagas, Matthew E

2014-08-01

We sought to examine whether vacuum-assisted closure (VAC) is associated with fewer surgical site infections (SSIs) or infections of chronic wounds than other management procedures for surgical wounds. The PubMed and Scopus databases were searched systematically. Randomized controlled trials (RCTs) comparing the development of SSIs or infections of chronic wounds between patients treated with VAC for acute or chronic wounds and those whose wounds were treated without VAC were considered eligible for inclusion in the study. Eight RCTs met the inclusion criteria for the study. Four of the studies included chronic or diabetic lower extremity wounds and four included fractures. In three of four studies reporting on fractures, the wounds were not closed post-operatively, whereas in one study primary closure of the wound was performed. With regard to wounds left open after the stabilization of fractures, patients whose wounds were treated with VAC developed fewer SSIs than those whose wounds were treated without VAC ([367 patients (196 with VAC; 171 without VAC) relative risk [RR], 0.47; 95% CI 0.28-0.81]). On the contrary, no difference in the development of SSIs occurred among patients with chronic or diabetic lower-extremity wounds treated with VAC and those whose wounds were treated without VAC ([638 patients (320 with VAC; 318 without VAC) RR 1.67; 95% CI: 0.71-3.94]). The available evidence suggests that the development of infections in wounds treated with VAC depends on the type of wound being treated.

Agreement between pre-operative and intra-operative bacteriological samples in 85 chronic peri-prosthetic infections.

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Matter-Parrat, V; Ronde-Oustau, C; Boéri, C; Gaudias, J; Jenny, J-Y

2017-04-01

Whether pre-operative microbiological sampling contributes to the management of chronic peri-prosthetic infection remains controversial. We assessed agreement between the results of pre-operative and intra-operative samples in patients undergoing single-stage prosthesis exchange to treat chronic peri-prosthetic infection. Agreement between pre-operative and intra-operative samples exceeds 75% in patients undergoing single-stage exchange of a hip or knee prosthesis to treat chronic peri-prosthetic infection. This single-centre retrospective study included 85 single-stage prosthesis exchange procedures in 82 patients with chronic peri-prosthetic infection at the hip or knee. Agreement between pre-operative and intra-operative sample results was evaluated. Changes to the initial antibiotic regimen made based on the intra-operative sample results were recorded. Of 149 pre-operative samples, 109 yielded positive cultures, in 75/85 cases. Of 452 intra-operative samples, 354 yielded positive cultures, in 85/85 cases. Agreement was complete in 54 (63%) cases and partial in 9 (11%) cases; there was no agreement in the remaining 22 (26%) cases. The complete agreement rate was significantly lower than 75% (P=0.01). The initial antibiotic regimen was inadequate in a single case. Pre-operative sampling may contribute to the diagnosis of peri-prosthetic infection but is neither necessary nor sufficient to confirm the diagnosis and identify the causative agent. The spectrum of the initial antibiotic regimen cannot be safely narrowed based on the pre-operative sample results. We suggest the routine prescription of a probabilistic broad-spectrum antibiotic regimen immediately after the prosthesis exchange, even when a pathogen was identified before surgery. IV, retrospective study. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Genetic and Molecular Mechanisms Underlying Symbiotic Specificity in Legume-Rhizobium Interactions.

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Wang, Qi; Liu, Jinge; Zhu, Hongyan

2018-01-01

Legumes are able to form a symbiotic relationship with nitrogen-fixing soil bacteria called rhizobia. The result of this symbiosis is to form nodules on the plant root, within which the bacteria can convert atmospheric nitrogen into ammonia that can be used by the plant. Establishment of a successful symbiosis requires the two symbiotic partners to be compatible with each other throughout the process of symbiotic development. However, incompatibility frequently occurs, such that a bacterial strain is unable to nodulate a particular host plant or forms nodules that are incapable of fixing nitrogen. Genetic and molecular mechanisms that regulate symbiotic specificity are diverse, involving a wide range of host and bacterial genes/signals with various modes of action. In this review, we will provide an update on our current knowledge of how the recognition specificity has evolved in the context of symbiosis signaling and plant immunity.

ESTs analysis reveals putative genes involved in symbiotic seed germination in Dendrobium officinale.

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Zhao, Ming-Ming; Zhang, Gang; Zhang, Da-Wei; Hsiao, Yu-Yun; Guo, Shun-Xing

2013-01-01

Dendrobiumofficinale (Orchidaceae) is one of the world's most endangered plants with great medicinal value. In nature, D. officinale seeds must establish symbiotic relationships with fungi to germinate. However, the molecular events involved in the interaction between fungus and plant during this process are poorly understood. To isolate the genes involved in symbiotic germination, a suppression subtractive hybridization (SSH) cDNA library of symbiotically germinated D. officinale seeds was constructed. From this library, 1437 expressed sequence tags (ESTs) were clustered to 1074 Unigenes (including 902 singletons and 172 contigs), which were searched against the NCBI non-redundant (NR) protein database (E-value cutoff, e(-5)). Based on sequence similarity with known proteins, 579 differentially expressed genes in D. officinale were identified and classified into different functional categories by Gene Ontology (GO), Clusters of orthologous Groups of proteins (COGs) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The expression levels of 15 selected genes emblematic of symbiotic germination were confirmed via real-time quantitative PCR. These genes were classified into various categories, including defense and stress response, metabolism, transcriptional regulation, transport process and signal transduction pathways. All transcripts were upregulated in the symbiotically germinated seeds (SGS). The functions of these genes in symbiotic germination were predicted. Furthermore, two fungus-induced calcium-dependent protein kinases (CDPKs), which were upregulated 6.76- and 26.69-fold in SGS compared with un-germinated seeds (UGS), were cloned from D. officinale and characterized for the first time. This study provides the first global overview of genes putatively involved in D. officinale symbiotic seed germination and provides a foundation for further functional research regarding symbiotic relationships in orchids.

ESTs analysis reveals putative genes involved in symbiotic seed germination in Dendrobium officinale.

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Ming-Ming Zhao

Full Text Available Dendrobiumofficinale (Orchidaceae is one of the world's most endangered plants with great medicinal value. In nature, D. officinale seeds must establish symbiotic relationships with fungi to germinate. However, the molecular events involved in the interaction between fungus and plant during this process are poorly understood. To isolate the genes involved in symbiotic germination, a suppression subtractive hybridization (SSH cDNA library of symbiotically germinated D. officinale seeds was constructed. From this library, 1437 expressed sequence tags (ESTs were clustered to 1074 Unigenes (including 902 singletons and 172 contigs, which were searched against the NCBI non-redundant (NR protein database (E-value cutoff, e(-5. Based on sequence similarity with known proteins, 579 differentially expressed genes in D. officinale were identified and classified into different functional categories by Gene Ontology (GO, Clusters of orthologous Groups of proteins (COGs and Kyoto Encyclopedia of Genes and Genomes (KEGG pathways. The expression levels of 15 selected genes emblematic of symbiotic germination were confirmed via real-time quantitative PCR. These genes were classified into various categories, including defense and stress response, metabolism, transcriptional regulation, transport process and signal transduction pathways. All transcripts were upregulated in the symbiotically germinated seeds (SGS. The functions of these genes in symbiotic germination were predicted. Furthermore, two fungus-induced calcium-dependent protein kinases (CDPKs, which were upregulated 6.76- and 26.69-fold in SGS compared with un-germinated seeds (UGS, were cloned from D. officinale and characterized for the first time. This study provides the first global overview of genes putatively involved in D. officinale symbiotic seed germination and provides a foundation for further functional research regarding symbiotic relationships in orchids.

ESTs Analysis Reveals Putative Genes Involved in Symbiotic Seed Germination in Dendrobium officinale

Science.gov (United States)

Zhao, Ming-Ming; Zhang, Gang; Zhang, Da-Wei; Hsiao, Yu-Yun; Guo, Shun-Xing

2013-01-01

Dendrobium officinale (Orchidaceae) is one of the world’s most endangered plants with great medicinal value. In nature, D . officinale seeds must establish symbiotic relationships with fungi to germinate. However, the molecular events involved in the interaction between fungus and plant during this process are poorly understood. To isolate the genes involved in symbiotic germination, a suppression subtractive hybridization (SSH) cDNA library of symbiotically germinated D . officinale seeds was constructed. From this library, 1437 expressed sequence tags (ESTs) were clustered to 1074 Unigenes (including 902 singletons and 172 contigs), which were searched against the NCBI non-redundant (NR) protein database (E-value cutoff, e-5). Based on sequence similarity with known proteins, 579 differentially expressed genes in D . officinale were identified and classified into different functional categories by Gene Ontology (GO), Clusters of orthologous Groups of proteins (COGs) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The expression levels of 15 selected genes emblematic of symbiotic germination were confirmed via real-time quantitative PCR. These genes were classified into various categories, including defense and stress response, metabolism, transcriptional regulation, transport process and signal transduction pathways. All transcripts were upregulated in the symbiotically germinated seeds (SGS). The functions of these genes in symbiotic germination were predicted. Furthermore, two fungus-induced calcium-dependent protein kinases (CDPKs), which were upregulated 6.76- and 26.69-fold in SGS compared with un-germinated seeds (UGS), were cloned from D . officinale and characterized for the first time. This study provides the first global overview of genes putatively involved in D . officinale symbiotic seed germination and provides a foundation for further functional research regarding symbiotic relationships in orchids. PMID:23967335

Infrared variability and nature of symbiotic stars

Energy Technology Data Exchange (ETDEWEB)

Feast, M W; Robertson, B S.C.; Catchpole, R M [Royal Observatory, Cape Town (South Africa)

1977-05-01

Most symbiotic stars may be placed in one of two classes according to their infrared colours. In one group the systems contain an M type giant. In the other there is evidence for a star plus infrared emission from dust. JHKL photometry is given for three members of each class. Photometry of the VV Cephei system FR Sct is also given. No evidence for variability was found for systems without dust. The three systems with dust (RX Pup, RR Tel and PK 280-2/sup 0/.1) each show large variations of the stellar component (..delta..J, 1sup(m).6 to 2sup(m).7). It is concluded that these dusty systems contain Mira variables. For the systems without dust the mass transfer in the system is presumably through the inner Lagrangian point. For systems containing Miras it is possible that the companion accretes matter from a general stellar wind. Symbiotic systems containing Mira variables have more dust than average Mira variables. Either an unusually dense stellar wind is needed to produce a symbiotic system or such a system produces dust, perhaps in a high-density region resulting from the interaction of the stellar wind with the companion.

Economics of symbiotic nuclear fleets at equilibrium

International Nuclear Information System (INIS)

Bidaud, Adrien; Guillemin, P.; Lecarpentier, David

2008-01-01

Many decades of industrial experience have proven that thermal reactors are able to provide a safe, reliable and competitive source of electricity. The higher construction costs of fast reactors compared to thermal reactors could be compensated by their better use of fissile material during the probable fast development of nuclear energy in the first half of the century. Thus, despite the over-cost of their cores, on the longer term, fast reactors are expected to take the lead in the nuclear reactor race. In the mean term, multi-strata symbiotic parks, using high conversion-rate thermal reactors, may delay fast reactor start up. We compare projected fuel cycle costs and cost of electricity of various symbiotic nuclear fleets, on the basis of a simple economic model and elementary costs estimated on publicly available data. These parameters and their evolution over reactor-life time scale can hardly be estimated. That is why we look at the sensitivities of our results to large modifications of the input parameters. The aim of our simple economic model is to understand which reactor characteristics should be optimized to enhance their economic performance when working as a single symbiotic fleet. (authors)

Chronic hepatitis C infection and liver disease in HIV co-infected patients in Asia

Science.gov (United States)

Durier, Nicolas; Yunihastuti, Evy; Ruxrungtham, Kiat; Van Kinh, Nguyen; Kamarulzaman, Adeeba; Boettiger, David; Widhani, Alvina; Avihingsanon, Anchalee; Huy, Bui Vu; Omar, Sharifah Faridah binti Syed; Sanityoso, Andri; Chittmittrapap, Salyavit; Dung, Nguyen Thi Hoai; Pillai, Veena; Suwan-Ampai, Tuangporn; Law, Matthew; Sohn, Annette H.; Matthews, Gail

2016-01-01

Data on markers of hepatitis C virus (HCV) disease in HIV-HCV co-infected patients in resource-limited settings are scarce. We assessed HCV-RNA, HCV genotype (GT), IL28B GT, and liver fibrosis (FibroScan®) in 480 HIV-infected patients with positive HCV antibody in four HIV treatment centers in South East Asia. We enrolled 165 (34.4%) patients in Jakarta, 158 (32.9%) in Bangkok, 110 (22.9%) in Hanoi, and 47 (9.8%) in Kuala Lumpur. Overall, 426 (88.8%) were male, the median (IQR) age was 38.1 (34.7–42.5) years, 365 (76.0%) reported HCV exposure through injecting drug use, and 453 (94.4%) were on combination antiretroviral therapy. The median (IQR) CD4 count was 446 (325–614) cells/mm3 and 208 (94.1%) of 221 patients tested had HIV-1 RNA F4). One patient (0.3%) had FibroScan® failure. A high proportion of HIV-HCV co-infected patients had chronic HCV infection. HCV GT1 was predominant, and 62% of patients had liver disease warranting prompt treatment (>=F2). PMID:27917597

Insect symbiotic bacteria harbour viral pathogens for transovarial transmission.

Science.gov (United States)

Jia, Dongsheng; Mao, Qianzhuo; Chen, Yong; Liu, Yuyan; Chen, Qian; Wu, Wei; Zhang, Xiaofeng; Chen, Hongyan; Li, Yi; Wei, Taiyun

2017-03-06

Many insects, including mosquitoes, planthoppers, aphids and leafhoppers, are the hosts of bacterial symbionts and the vectors for transmitting viral pathogens 1-3 . In general, symbiotic bacteria can indirectly affect viral transmission by enhancing immunity and resistance to viruses in insects 3-5 . Whether symbiotic bacteria can directly interact with the virus and mediate its transmission has been unknown. Here, we show that an insect symbiotic bacterium directly harbours a viral pathogen and mediates its transovarial transmission to offspring. We observe rice dwarf virus (a plant reovirus) binding to the envelopes of the bacterium Sulcia, a common obligate symbiont of leafhoppers 6-8 , allowing the virus to exploit the ancient oocyte entry path of Sulcia in rice leafhopper vectors. Such virus-bacterium binding is mediated by the specific interaction of the viral capsid protein and the Sulcia outer membrane protein. Treatment with antibiotics or antibodies against Sulcia outer membrane protein interferes with this interaction and strongly prevents viral transmission to insect offspring. This newly discovered virus-bacterium interaction represents the first evidence that a viral pathogen can directly exploit a symbiotic bacterium for its transmission. We believe that such a model of virus-bacterium communication is a common phenomenon in nature.

Late-type components of slow novae and symbiotic stars

Energy Technology Data Exchange (ETDEWEB)

Allen, D A [Anglo-Australian Observatory, Epping (Australia); Royal Observatory, Edinburgh (UK))

1980-08-01

It is argued that the various types of symbiotic stars and the slow novae are the same phenomena exhibiting a range of associated time-scales, the slow novae being of intermediate speed. Evidence is summarized showing that both types of object contain normal M giants or mira variables. This fact is at odds with currently fashionable single-star models for slow novae, according to which the M star is totally disrupted before the outburst. Spectral types of the late-type components are presented for nearly 80 symbiotic stars and slow novae, derived from 2 ..mu..m spectroscopy. It is found that both the intensity of the emission spectrum and the electron density of the gas are functions of the spectral type of the late-type star. Explanations for these correlations are given. On the assumption that the late-type components are normal giants, spectroscopic parallaxes are determined; credible distances are derived which indicate that the known symbiotic stars have been sampled as far afield as the Galactic Centre. Hydrogen shell flashes on a white dwarf accreting gas from the late-type components offer an attractive explanation of the phenomena of slow novae and symbiotic stars, and such models are discussed in the concluding section.

Does a Common Pathway Transduce Symbiotic Signals in Plant-Microbe Interactions?

Science.gov (United States)

Genre, Andrea; Russo, Giulia

2016-01-01

Recent years have witnessed major advances in our knowledge of plant mutualistic symbioses such as the rhizobium-legume symbiosis (RLS) and arbuscular mycorrhizas (AM). Some of these findings caused the revision of longstanding hypotheses, but one of the most solid theories is that a conserved set of plant proteins rules the transduction of symbiotic signals from beneficial glomeromycetes and rhizobia in a so-called common symbiotic pathway (CSP). Nevertheless, the picture still misses several elements, and a few crucial points remain unclear. How does one common pathway discriminate between - at least - two symbionts? Can we exclude that microbes other than AM fungi and rhizobia also use this pathway to communicate with their host plants? We here discuss the possibility that our current view is biased by a long-lasting focus on legumes, whose ability to develop both AM and RLS is an exception among plants and a recent innovation in their evolution; investigations in non-legumes are starting to place legume symbiotic signaling in a broader perspective. Furthermore, recent studies suggest that CSP proteins act in a wider scenario of symbiotic and non-symbiotic signaling. Overall, evidence is accumulating in favor of distinct activities for CSP proteins in AM and RLS, depending on the molecular and cellular context where they act.

Environmental Burkholderia cenocepacia Strain Enhances Fitness by Serial Passages during Long-Term Chronic Airways Infection in Mice

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Alessandra Bragonzi

2017-11-01

Full Text Available Burkholderia cenocepacia is an important opportunistic pathogen in cystic fibrosis (CF patients, and has also been isolated from natural environments. In previous work, we explored the virulence and pathogenic potential of environmental B. cenocepacia strains and demonstrated that they do not differ from clinical strains in some pathogenic traits. Here, we investigated the ability of the environmental B. cenocepacia Mex1 strain, isolated from the maize rhizosphere, to persist and increase its virulence after serial passages in a mouse model of chronic infection. B. cenocepacia Mex1 strain, belonging to the recA lineage IIIA, was embedded in agar beads and challenged into the lung of C57Bl/6 mice. The mice were sacrificed after 28 days from infection and their lungs were tested for bacterial loads. Agar beads containing the pool of B. cenocepacia colonies from the four sequential passages were used to infect the mice. The environmental B. cenocepacia strain showed a low incidence of chronic infection after the first passage; after the second, third and fourth passages in mice, its ability to establish chronic infection increased significantly and progressively up to 100%. Colonial morphology analysis and genetic profiling of the Mex1-derived clones recovered after the fourth passage from infected mice revealed that they were indistinguishable from the challenged strain both at phenotypic and genetic level. By testing the virulence of single clones in the Galleria mellonella infection model, we found that two Mex1-derived clones significantly increased their pathogenicity compared to the parental Mex1 strain and behaved similarly to the clinical and epidemic B. cenocepacia LMG16656T. Our findings suggest that serial passages of the environmental B. cenocepacia Mex1 strain in mice resulted in an increased ability to determine chronic lung infection and the appearance of clonal variants with increased virulence in non-vertebrate hosts.

Recurrent signature patterns in HIV-1 B clade envelope glycoproteins associated with either early or chronic infections.

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S Gnanakaran

2011-09-01

Full Text Available Here we have identified HIV-1 B clade Envelope (Env amino acid signatures from early in infection that may be favored at transmission, as well as patterns of recurrent mutation in chronic infection that may reflect common pathways of immune evasion. To accomplish this, we compared thousands of sequences derived by single genome amplification from several hundred individuals that were sampled either early in infection or were chronically infected. Samples were divided at the outset into hypothesis-forming and validation sets, and we used phylogenetically corrected statistical strategies to identify signatures, systematically scanning all of Env. Signatures included single amino acids, glycosylation motifs, and multi-site patterns based on functional or structural groupings of amino acids. We identified signatures near the CCR5 co-receptor-binding region, near the CD4 binding site, and in the signal peptide and cytoplasmic domain, which may influence Env expression and processing. Two signatures patterns associated with transmission were particularly interesting. The first was the most statistically robust signature, located in position 12 in the signal peptide. The second was the loss of an N-linked glycosylation site at positions 413-415; the presence of this site has been recently found to be associated with escape from potent and broad neutralizing antibodies, consistent with enabling a common pathway for immune escape during chronic infection. Its recurrent loss in early infection suggests it may impact fitness at the time of transmission or during early viral expansion. The signature patterns we identified implicate Env expression levels in selection at viral transmission or in early expansion, and suggest that immune evasion patterns that recur in many individuals during chronic infection when antibodies are present can be selected against when the infection is being established prior to the adaptive immune response.

Genetic variation of hepatitis B surface antigen among acute and chronic hepatitis B virus infections in The Netherlands.

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Cremer, Jeroen; Hofstraat, Sanne H I; van Heiningen, Francoise; Veldhuijzen, Irene K; van Benthem, Birgit H B; Benschop, Kimberley S M

2018-05-24

Genetic variation within hepatitis B surface antigen (HBsAg), in particular within the major hydrophobic region (MHR), is related to immune/vaccine and test failures and can have a significant impact on the vaccination and diagnosis of acute infection. This study shows, for the first time, variation among acute cases and compares the amino acid variation within the HBsAg between acute and chronic infections. We analyzed the virus isolated from 1231 acute and 585 chronic cases reported to an anonymized public health surveillance database between 2004 and 2014 in The Netherlands. HBsAg analysis revealed the circulation of 6 genotypes (Gt); GtA was the dominant genotype followed by GtD among both acute (68.2% and 17.4%, respectively) and chronic (34.9% and 34.2%, respectively) cases. Variation was the highest among chronic strains compared to that among acute strains. Both acute and chronic GtD showed the highest variation compared to that of other genotypes (P < .01). Substitutions within the MHR were found in 8.5% of the acute strains and 18.6% of the chronic strains. Specific MHR substitutions described to have an impact on vaccine/immune escape and/or HBsAg test failure were found among 4.1% of the acute strains and 7.0% of the chronic strains. In conclusion, we show a high variation of HBsAg among acute and chronic hepatitis B virus-infected cases in The Netherlands, in particular among those infected with GtD, and compare, for the first time, variation in frequencies between acute and chronic cases. Additional studies on the impact of these variations on vaccination and test failure need to be conducted, as well as whether HBsAg false-negative variants have been missed. © 2018 The Authors. Journal of Medical Virology Published by Wiley Periodicals, Inc.

Assessment of immunological changes in Epstein-Barr virus co-infection in Egyptian chronic HCV patients

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Sahar Shoman

2014-09-01

Full Text Available Epstein-Barr virus (EBV plays a major role in liver pathology. Similar to other members of the herpesvirus family, EBV establishes a persistent infection in more than 90% of adults. The aim of this study was to evaluate the impact of EBV and chronic hepatitis C co-infection (HCV on biochemical and immunological responses in patients. The study was conducted in 62 patients and 33 apparently healthy controls. Patients were divided into three groups: group I, consisting of 31 patients with chronic hepatitis C infection (CHC, group II, consisting of eight patients with EBV infection and without HCV infection and group III, consisting of 23 patients with EBV and chronic HCV. The percentage of CD3+ cells, helper CD4+ cells and CD19+ B-cells was measured by flow cytometry. Human interferon-γ (IFN-γ and interleukin (IL-15 levels were measured by an ELISA. The levels of liver alanine aminotransferase and aspartate aminotransferase enzymes were higher in EBV/HCV patients compared to that in EBV and HCV mono-infected patients. EBV/HCV patients had significantly reduced percentages of CD3+ and CD4+ cells compared to EBV patients. Serum IFN-γ levels were significantly reduced in EBV/HCV patients (3.86 pg/mL compared to CHC patients (6.76 pg/mL and normal controls (4.69 pg/mL. A significant increase in serum IL-15 levels was observed in EBV/HCV patients (67.7 pg/mL compared to EBV patients (29.3 pg/mL. Taken together, these observations suggest that HCV and EBV co-infection can potentiate immune response dampening in patients.

Infection dynamic of symbiotic bacteria in the pea aphid Acyrthosiphon pisum gut and host immune response at the early steps in the infection process.

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Renoz, François; Noël, Christine; Errachid, Abdelmounaim; Foray, Vincent; Hance, Thierry

2015-01-01

In addition to its obligatory symbiont Buchnera aphidicola, the pea aphid Acyrthosiphon pisum can harbor several facultative bacterial symbionts which can be mutualistic in the context of various ecological interactions. Belonging to a genus where many members have been described as pathogen in invertebrates, Serratia symbiotica is one of the most common facultative partners found in aphids. The recent discovery of strains able to grow outside their host allowed us to simulate environmental acquisition of symbiotic bacteria by aphids. Here, we performed an experiment to characterize the A. pisum response to the ingestion of the free-living S. symbiotica CWBI-2.3T in comparison to the ingestion of the pathogenic Serratia marcescens Db11 at the early steps in the infection process. We found that, while S. marcescens Db11 killed the aphids within a few days, S. symbiotica CWBI-2.3T did not affect host survival and colonized the whole digestive tract within a few days. Gene expression analysis of immune genes suggests that S. symbiotica CWBI-2.3T did not trigger an immune reaction, while S. marcescens Db11 did, and supports the hypothesis of a fine-tuning of the host immune response set-up for fighting pathogens while maintaining mutualistic partners. Our results also suggest that the lysosomal system and the JNK pathway are possibly involved in the regulation of invasive bacteria in aphids and that the activation of the JNK pathway is IMD-independent in the pea aphid.

Induction of Type I Interferons by Therapeutic Nanoparticle-Based Vaccination Is Indispensable to Reinforce Cytotoxic CD8+ T Cell Responses During Chronic Retroviral Infection

Science.gov (United States)

Knuschke, Torben; Rotan, Olga; Bayer, Wibke; Kollenda, Sebastian; Dickow, Julia; Sutter, Kathrin; Hansen, Wiebke; Dittmer, Ulf; Lang, Karl S.; Epple, Matthias; Buer, Jan; Westendorf, Astrid M.

2018-01-01

T cell dysfunction and immunosuppression are characteristic for chronic viral infections and contribute to viral persistence. Overcoming these burdens is the goal of new therapeutic strategies to cure chronic infectious diseases. We recently described that therapeutic vaccination of chronic retrovirus infected mice with a calcium phosphate (CaP) nanoparticle (NP)-based vaccine carrier, functionalized with CpG and viral peptides is able to efficiently reactivate the CD8+ T cell response and improve the eradication of virus infected cells. However, the mechanisms underlying this effect were largely unclear. While type I interferons (IFNs I) are considered to drive T cell exhaustion by persistent immune activation during chronic viral infection, we here describe an indispensable role of IFN I induced by therapeutic vaccination to efficiently reinforce cytotoxic CD8+ T cells (CTL) and improve control of chronic retroviral infection. The induction of IFN I is CpG dependent and leads to significant IFN signaling indicated by upregulation of IFN stimulated genes. By vaccinating chronically retrovirus-infected mice lacking the IFN I receptor (IFNAR−/−) or by blocking IFN I signaling in vivo during therapeutic vaccination, we demonstrate that IFN I signaling is necessary to drive full reactivation of CTLs. Surprisingly, we also identified an impaired suppressive capability of regulatory T cells in the presence of IFNα, which implicates an important role for vaccine-induced IFNα in the regulation of the T cell response during chronic retroviral infection. Our data suggest that inducing IFN I signaling in conjunction with the presentation of viral antigens can reactivate immune functions and reduce viral loads in chronic infections. Therefore, we propose CaP NPs as potential therapeutic tool to treat chronic infections. PMID:29740425

Health implications of chronic hepatosplenomegaly in Kenyan school-aged children chronically exposed to malarial infections and Schistosoma mansoni

DEFF Research Database (Denmark)

Wilson, Shona; Vennervald, Birgitte J; Kadzo, Hilda

2010-01-01

Hepatosplenomegaly among school-aged children in sub-Saharan Africa is highly prevalent. Two of the more common aetiological agents of hepatosplenomegaly, namely chronic exposure to malaria and Schistosoma mansoni infection, can result in similar clinical presentation, with the liver and spleen...... being chronically enlarged and of a firm consistency. Where co-endemic, the two parasites are thought to synergistically exacerbate hepatosplenomegaly. Here, two potential health consequences, i.e. dilation of the portal vein (indicative of increased portal pressure) and stunting of growth, were...... with hepatosplenomegaly. Children who presented with hepatosplenomegaly had the lowest height-for-age Z-scores. This study shows that hepatosplenomegaly associated with chronic exposure to malaria and schistosomiasis is not a benign symptom amongst school-aged children but has potential long-term health consequences....

PFGE and antibiotic susceptibility phenotype analysis of Pseudomonas aeruginosa strain chronically infecting Cystic Fibrosis patients

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Giovanna Pulcrano

2008-09-01

Full Text Available Pseudomonas aeruginosa is the leading cause of chronic lung infection and following pulmonary worsening of cystic fibrosis patients. To verify whether bacterial modifications regarding motility, mucoidy, and serum susceptibility proceeded from an adaptation to chronic infection or a replacement with a new strain, sequential P. aeruginosa isolates of known phenotype collected from 5 cystic fibrosis patients were typed by pulsed-field gel electophoresis (PFGE. Antimicrobial susceptibility testing of all isolates was performed by the disc diffusion method. PFGE typing demonstrated that strains dissimilar in colony morphotype and of different antibiotic susceptibility patterns could be of the same genotype. Some patients were colonized with a rather constant P. aeruginosa flora, with strains of different phenotypes but of one genotype. Instead, some patients may be colonized by more than one genotype. Secretion of mucoid exopolysaccharide and acquisition of a new antibiotic susceptibility phenotype in these strain appear to evolve during chronic colonization in cystic fibrosis patients from specific adaptation to infection rather than from acquisition of new bacterial strains.

Chronic Actinomyces Infection Caused by Retained Cervical Cerclage: A Case Report.

Science.gov (United States)

Lyttle, Brianna; Johnson, Julia V

2016-01-01

Historically, Actinomyces infection has been associated primarily with the intrauterine device. Recently, case reports associating Actinomyces with other implants have been described, including nonwoven polypropylene mesh used for urethral slings and Mersilene cerclage placements. However, there are no reported cases of chronic Actinomyces infections associated with retained Mersilene cerclage. A 51-year-old woman, gravida 3, para 3, presented with a 10-year history of vaginal discharge and Actinomyces identified on endometrial biopsy. After failing medical treatment and undergoing a hysterectomy, the patient was found to have a retained Mersilene cerclage. This is the first case to report persistent Actinomyces infection with a retained Mersilene cerclage. No current recommendations exist for assessing full removal of cerclage. Clinicians should have a high suspicion of Actinomyces infection in a patient who presents with persistent vaginal discharge and history of cerclage placement.

Autoimmunity and Extrahepatic Manifestations in Treatment-Naïve Children with Chronic Hepatitis C Virus Infection

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Giuseppe Indolfi

2012-01-01

Full Text Available Hepatitis C virus (HCV infection has been associated with autoimmunity and extrahepatic manifestations in adults. Few data are available on these topics in children. Nonorgan specific auto-antibodies development is part of the natural course of chronic hepatitis C in children. Smooth muscle autoantibody is the most common autoantibody found, while liver-kidney microsomal type-1 antibody positivity is the most peculiar autoimmune feature of children with HCV infection. The clinical significance of non-organ specific autoantibodies in the course of paediatric chronic hepatitis C is still debated. Autoantibody positivity can be considered neutral for most patients, while it can be associated with negative connotations for others, especially those positive for liver-kidney microsomal type-1 autoantibody. Subclinical hypothyroidism but not autoimmune thyroiditis has been demonstrated in HCV infection in children, while only few cases of HCV-associated membranoproliferative glomerulonephritis have been described. Single reports are available in the literature reporting the anecdotal association between chronic hepatitis C and other extrahepatic manifestations such as myopathy and opsoclonus-myoclonus syndrome. Despite the low incidence of extrahepatic manifestations of chronic hepatitis C in children, overall, available data suggest a careful monitoring.

Hepatitis virus infection and chronic liver disease among atomic-bomb survivors

Energy Technology Data Exchange (ETDEWEB)

Fujiwara, S.; Cologne, J.; Akahoshi, M. [Radiation Effects Research Foundation, Hiroshima (Japan); Kusumi, S.; Kodama, K.; Yoshizawa, H.

2000-05-01

The purpose of this study is to analyze various laboratory indicators of inflammation measured in atomic bomb survivors. Subjects are 6304 survivors who underwent inflammatory tests at RERF between 1998 and 1992 and whose radiation doses (DS86) are available. Inflammatory tests include leukocyte counts, neutrophil counts, erythrocyte sedimentation rate, corrected erythrocyte sedimentation rate, alpha 1 globulin, alpha 2 globulin, and sialic acid. Adjusting for age, sex, smoking, and city of residence, regression analysis was conducted. Regression analysis, adjusted for age, sex, smoking, and city of residence showed statistically significant associations with radiation dose for leukocyte counts (71.0 /mm{sup 3}/Gy, p=0.00151), erythrocyte sedimentation rate (1.58 mm/hour/Gy, p=0.0001), corrected erythrocyte sedimentation rate (1.14 mm/hour/Gy, p=0.0001), alpha 1 globulin (0.0057 g/dl/Gy, p=0.0001), alpha 2 globulin (0.0128 g/dl/Gy, p=0.0001), and sialic acid (1.2711 mg/dl/Gy, p=0.0001), but not for neutrophil counts (29.9 /mm{sup 3}/Gy, p=0.1729). Standardized scores combining results from these seven inflammatory tests showed significant associations with radiation dose both for persons with and without inflammatory disease, and for two inflammatory conditions in particular, chronic thyroiditis and chronic liver disease. In analyses of data from 403 AHS patients, in whom both inflammation indicators and T-cell ratios were measured, increased inflammation correlates with decreases in CD4 T-cells. Since the laboratory indicators of inflammation that we studied are not specific for particular clinical diseases, the implication of their dose-response-pattern is hard to interpret. The general occurrence of infectious diseases in survivors is not related to radiation dose. Such a relationship does exist, however, for other diseases in which infection may play an etiologic role. Virologic studies in A-bomb survivors have suggested dose-response alterations in immune

Latent toxoplasmosis is associated with neurocognitive impairment in young adults with and without chronic HIV infection.

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Ene, L; Marcotte, T D; Umlauf, A; Grancea, C; Temereanca, A; Bharti, A; Achim, C L; Letendre, S; Ruta, S M

2016-10-15

We evaluated the impact of latent toxoplasmosis (LT) on neurocognitive (NC) and neurobehavioural functioning in young adults with and without chronic HIV infection, using a standardised NC test battery, self-reported Beck Depression Inventory, Frontal System Behavior Scale, MINI-International Neuropsychiatric Interview and risk-assessment battery. 194 young adults (median age 24years, 48.2% males) with chronic HIV infection (HIV+) since childhood and 51 HIV seronegative (HIV-) participants were included. HIV+ individuals had good current immunological status (median CD4: 479 cells/μl) despite a low CD4 nadir (median: 93 cells/μl). LT (positive anti-Toxoplasma IgG antibodies) was present in one third of participants. The impairment rates in the HIV- with and without Toxo were not significantly different (p=0.17). However, we observed an increasing trend (pToxoplasmosis may contribute to NC impairment in young adults, including those with and without chronic HIV infection. Copyright © 2016 Elsevier B.V. All rights reserved.

Genus Phyllanthus for chronic hepatitis B virus infection

DEFF Research Database (Denmark)

Liu, J; Lin, Haili; McIntosh, H

2001-01-01

To evaluate the efficacy and safety of genus Phyllanthus for chronic hepatitis B virus (HBV) infection we performed a systematic review of randomized clinical trials. Randomized trials comparing genus Phyllanthus vs. placebo, no intervention, general nonspecific treatment, other herbal medicine.......85-17.21) compared with placebo or no intervention. There was no significant difference on clearance of serum HBsAg, HBeAg and HBV DNA between Phyllanthus and IFN. Phyllanthus species were better than nonspecific treatment or other herbal medicines for the clearance of serum HBsAg, HBeAg, HBV DNA, and liver enzyme...

Profile disparity of Raman-scattered O VI in symbiotic stars

International Nuclear Information System (INIS)

Lee, Hee-Won

2016-01-01

Symbiotic stars are wide binary systems consisting of a hot compact star (usually a white dwarf) and a mass losing giant. Symbiotic activities are believed to occur through gravitational capture of a fraction of the slow stellar wind from the giant. Raman scattered features of O VI resonance doublet 1032 and 1038 appearing at around 6825 Å and 7082 Å are a unique spectroscopic diagnostic tool to probe the mass transfer process in symbiotic stars. The Raman O VI features often exhibit multiple peak structures and in many cases the blue peak of 7082 features is relatively more suppressed than that of 6825 features. We propose that the disparity of the two profiles is attributed to the local variation of optical depths of O VI, implying that the accretion flow is convergent in the red emission region and divergent in the blue emission region. It is argued in this presentation that Raman scattering by atomic hydrogen is a natural mirror to provide an edge-on view of the accretion disk and a lateral view of the bipolar outflow in symbiotic stars. We discuss the spectropolarimetric implications of this interpretation. (paper)

Mycobacterium tuberculosis from chronic murine infections that grows in liquid but not on solid medium

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Mitchison Denis A

2004-11-01

Full Text Available Abstract Background Old, stationary cultures of Mycobacterium tuberculosis contain a majority of bacteria that can grow in broth cultures but cannot grow on solid medium plates. These may be in a non-replicating, dormant growth phase. We hypothesised that a similar population might be present in chronic, murine tuberculosis. Methods Estimates of the numbers of viable M. tuberculosis, strain H37Rv, in the spleens and lungs of mice in a 7-day acute infection and in a 10-month chronic infection were made by conventional plate counts and, as broth counts, by noting presence or absence of growth in serial replicate dilutions in liquid medium. Results Plate and broth counts in 6 mice gave similar mean values in the acute infection, 7 days after infection. However, the broth counts were much higher in 36 mice with a chronic infection at 10 months. Broth counts averaged 5.290 log10 cfu /organ from spleens and 5.523 log10 cfu/organ from lungs, while plate counts were 3.858 log10 cfu/organ from spleens and 3.662 log10 cfu/organ from lungs, indicating that the total bacterial population contained only 3.7% bacilli in spleens and 1.4% bacilli in lungs, capable of growth on plates. Conclusion The proportion growing on plates might be a measure of the "dormancy" of the bacilli equally applicable to cultural and animal models.

FLOW MEDIATED DILATION AND CAROTID INTIMA MEDIA THICKNESS IN PATIENTS WITH CHRONIC GASTRITIS ASSOCIATED WITH HELICOBACTER PYLORI INFECTION.

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Judaki, Arezo; Norozi, Siros; Ahmadi, Mohammad Reza Hafezi; Ghavam, Samira Mis; Asadollahi, Khairollah; Rahmani, Asghar

2017-12-01

Endothelial dysfunction is one of the early stages of vascular diseases. The aim of this study was to investigate the endothelial dysfunction markers in patients with chronic gastritis associated with Helicobacter pylori (H. pylori) infection. By a cross sectional study, basic and clinical information of 120 participants (40 patients with positive H. pylori infection, 40 patients with negative H. pylori infection and 40 healthy people) were analyzed. Carotid intima media thickness and flow-mediated dilation levels were measured in all patients and controls. Soluble vascular cell adhesion molecule-1 (sVCAM-1) and intercellular adhesion molecule-1 (ICAM-1) were measured with Elisa for all subjects. IgG level was assessed in chronic gastritis patients. The flow-mediated dilation level in patients with positive H. pylori infection (0.17%±0.09) was significantly lower than those with negative H. pylori infection (0.21% ±0.10, Pgastritis. The levels of flow-mediated dilation, carotid intima media thickness and sICAM-1 were higher among patients with positive H. pylori infection. Patients with chronic gastritis associated with H. pylori infection are at risk of endothelial dysfunction due to flow-mediated dilation and carotid intima media thickness abnormalities and increased level of sICAM-1 and sVCAM-1.

Chronic hepatitis B infection and HBV DNA-containing capsids: Modeling and analysis

Science.gov (United States)

Manna, Kalyan; Chakrabarty, Siddhartha P.

2015-05-01

We analyze the dynamics of chronic HBV infection taking into account both uninfected and infected hepatocytes along with the intracellular HBV DNA-containing capsids and the virions. While previous HBV models have included either the uninfected hepatocytes or the intracellular HBV DNA-containing capsids, our model accounts for both these two populations. We prove the conditions for local and global stability of both the uninfected and infected steady states in terms of the basic reproduction number. Further, we incorporate a time lag in the model to encompass the intracellular delay in the production of the infected hepatocytes and find that this delay does not affect the overall dynamics of the system. The results for the model and the delay model are finally numerically illustrated.

Induction of Type I Interferons by Therapeutic Nanoparticle-Based Vaccination Is Indispensable to Reinforce Cytotoxic CD8+ T Cell Responses During Chronic Retroviral Infection

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Torben Knuschke

2018-04-01

Full Text Available T cell dysfunction and immunosuppression are characteristic for chronic viral infections and contribute to viral persistence. Overcoming these burdens is the goal of new therapeutic strategies to cure chronic infectious diseases. We recently described that therapeutic vaccination of chronic retrovirus infected mice with a calcium phosphate (CaP nanoparticle (NP-based vaccine carrier, functionalized with CpG and viral peptides is able to efficiently reactivate the CD8+ T cell response and improve the eradication of virus infected cells. However, the mechanisms underlying this effect were largely unclear. While type I interferons (IFNs I are considered to drive T cell exhaustion by persistent immune activation during chronic viral infection, we here describe an indispensable role of IFN I induced by therapeutic vaccination to efficiently reinforce cytotoxic CD8+ T cells (CTL and improve control of chronic retroviral infection. The induction of IFN I is CpG dependent and leads to significant IFN signaling indicated by upregulation of IFN stimulated genes. By vaccinating chronically retrovirus-infected mice lacking the IFN I receptor (IFNAR−/− or by blocking IFN I signaling in vivo during therapeutic vaccination, we demonstrate that IFN I signaling is necessary to drive full reactivation of CTLs. Surprisingly, we also identified an impaired suppressive capability of regulatory T cells in the presence of IFNα, which implicates an important role for vaccine-induced IFNα in the regulation of the T cell response during chronic retroviral infection. Our data suggest that inducing IFN I signaling in conjunction with the presentation of viral antigens can reactivate immune functions and reduce viral loads in chronic infections. Therefore, we propose CaP NPs as potential therapeutic tool to treat chronic infections.

Virus-specific cytotoxic T cells in chronic active Epstein-Barr virus infection.

Science.gov (United States)

Shibayama, Haruna; Imadome, Ken-Ichi; Onozawa, Erika; Tsuzura, Akiho; Miura, Osamu; Koyama, Takatoshi; Arai, Ayako

2017-01-01

Chronic active Epstein-Barr virus infection (CAEBV) is a disease characterized by clonally proliferating and activated EBV-infected T or NK cells accompanied by chronic inflammation and T- or NK-cell neoplasms. However, the mechanism for developing CAEBV has not been clarified to date. Because the decreased number or inactivation of EBV-specific cytotoxic T lymphocytes (CTLs) resulted in the development of EBV-positive B-cell neoplasms, we investigated the number of CTLs in CAEBV patients using the tetrameric complexes of HLA-restricted EBV-specific peptides. Among the seven patients examined, EBV-specific CTLs were detected in the peripheral blood mononuclear cells (PBMCs) of four cases but were not detected in three cases. The ratio of EBV-specific CTLs in PBMCs tended to be higher in the patients with active disease than in those with inactive disease. In two patients in whom EBV-specific CTLs had not been detected, CTLs appeared after the eradication of EBV-infected T cells by allogeneic bone marrow transplantation. These results suggested that the failure of CTLs had a role in developing CAEBV, although the induction number and function of EBV-specific CTLs might vary in each patient.

Chronic Active Epstein–Barr Virus Infection

Directory of Open Access Journals (Sweden)

Li Jun

2012-06-01

Full Text Available Chronic active Epstein-Barr virus (CAEBV infection is a systemic Epstein-Barr virus (EBV positive lymphoprolifetative disease characterized by fever, lymphadenopathy, splenomegaly, unusual pattern of anti- EBV antibodies, and/or increased EBV genomes in affected tissues. Most cases are from Asia. So far, there is hardly any adult case reported from mainland of China. We herein presented a 33-year-old man with fever, facial erythema and rash, lymphadenopathy, lower limbs weakness, splenomegaly and liver lesion. EBV VCA, EA and EBNA were all positive. EBV DNA could be found in serum and PBMC. In situ hybridization of EBV encoded RNA in skin and liver biopsy was positive. Viral load in serum decreased under interferon alpha therapy. To our knowledge, it’s the first adult case reported from mainland of China.

Symbiotic star UV emission and theoretical models

International Nuclear Information System (INIS)

Kafatos, M.

1982-01-01

Observations of symbiotic stars in the far UV have provided important information on the nature of these objects. The canonical spectrum of a symbiotic star, e.g. RW Hya, Z And, AG Peg, is dominated by strong allowed and semiforbidden lines of a variety of at least twice ionized elements. Weaker emission from neutral and singly ionized species is also present. A continuum may or may not be present in the 1200 - 2000 A range but is generally present in the range 2000 - 3200 A range. The suspected hot subdwarf continuum is seen in some cases in the range 1200 - 2000 A (RW Hya, AG Peg, SY Mus). The presence of an accretion disk is difficult to demonstrate and to this date the best candidate for accretion to a main sequence star remains CI Cyg. A number of equations have been derived by the author that can yield the accretion parameters from the observable quantities. Boundary layer temperatures approximately 10 5 K and accretion rates approximately > 10 -5 solar masses/yr are required for accreting main sequence companions. To this date, though, most of the symbiotics may only require the presence of a approximately 10 5 K hot subdwarf. (Auth.)

He 2-104 - A symbiotic proto-planetary nebula?

International Nuclear Information System (INIS)

Schwarz, H.E.; Aspin, C.; Lutz, J.H.

1989-01-01

CCD observations are presented for He 2-104, an object previously classified as both PN and symbiotic star, which show that this is in fact a protoplanetary nebula (PPN) with a dynamical age of about 800 yr. The presence of highly collimated jets, extending over 75 arcsec on the sky, combined with an energy distribution showing a hot as well as a cool component, indicates that He 2-104 is a binary PPN. Since the primary is probably a Mira with a 400-d period (as reported by Whitelock, 1988), it is proposed that the system is a symbiotic PPN. 16 refs

Challenges in the management of chronic HBV infection in West Africa: The clinician's perspective.

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Okonkwo, Uchenna C; Onyekwere, Charles A

2016-01-01

Hepatitis B infection has become a public health issue in recent years. Approximately 350 million of the world's population are chronically infected reaching endemic proportions in West Africa. Guidelines for treatment are continuously improving but are becoming more complex. To determine the challenges hepatologists experience in the management of patients with chronic hepatitis B. This was a cross-sectional descriptive study conducted among hepatologists in West Africa during a regional hepatitis conference in 2013. Forty-six hepatologists completed the questionnaire. When evaluating a patient for chronic hepatitis B, the preferred investigations were: LFT (100%); abdominal ultrasound (93.5%); HBeAg (93.5%); HBV DNA (78%); HBsAg measure (22%); HBV genotype (15.2%); and liver biopsy (34.8%). Most had their patients on nucleoside/nucleotide analogue but follow-up visits after 1 year were problematic. The majority of hepatologists had good intentions regarding the evaluation of their patients, but only a small percentage of patients are properly investigated. © The Author(s) 2014.

Time trends of chronic HBV infection over prior decades - A global analysis.

Science.gov (United States)

Ott, Jördis J; Horn, Johannes; Krause, Gérard; Mikolajczyk, Rafael T

2017-01-01

Information on trends in chronic hepatitis B virus (HBV) prevalence across countries is lacking. We studied changes in chronic HBV infection over previous decades by country, and assessed patterns of change between and within WHO-defined regions. Based on data from a published systematic review on chronic HBV, we applied a linear model on the logit scale to assess time trends in country-specific prevalence. Estimated HBsAg prevalence in 2000 and relative changes in prevalence over time were evaluated by country and region. Sufficient data were available for 50 countries, mostly showing reductions in prevalence over time. Various degrees of heterogeneity were observed within regions, with a relatively homogenous pattern in the Eastern Mediterranean region with strong decreases in HBsAg prevalence. Europe showed a mixed pattern: higher and stable chronic HBsAg prevalence in Eastern, and constantly low prevalence in Western Europe. In Africa, some countries demonstrated no change in prevalence; increases were seen in Uganda (odds ratio 1.05 per year; 95% confidence interval 1.04-1.06), Nigeria (1.02; 1.02-1.02), Senegal (1.01; 1.01-1.02), and South Africa (1.02; 1.01-1.02). With some exceptions, country-patterns overlapped among countries of South East Asian and Western Pacific regions, characterized by low-medium HBsAg decreases, most prominent in China and Malaysia. Most countries experienced decreases in HBsAg prevalence. Dynamics varied, even within regions; decreases occurred mostly before the direct effects of childhood vaccination may have manifested. These findings together with stable and increasing HBsAg prevalence in some countries of Africa and Eastern Europe indicate the need for further tailored country-specific prevention. This study investigated time trends in prevalence of chronic HBV infection in 50 countries worldwide over the last decade, by estimating relative changes in prevalence. Results show decreases in chronic HBV infection in most countries

Taxonomically Different Co-Microsymbionts of a Relict Legume, Oxytropis popoviana, Have Complementary Sets of Symbiotic Genes and Together Increase the Efficiency of Plant Nodulation.

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Safronova, Vera I; Belimov, Andrey A; Sazanova, Anna L; Chirak, Elizaveta R; Verkhozina, Alla V; Kuznetsova, Irina G; Andronov, Evgeny E; Puhalsky, Jan V; Tikhonovich, Igor A

2018-06-20

Ten rhizobial strains were isolated from root nodules of a relict legume Oxytropis popoviana Peschkova. For identification of the isolates, sequencing of rrs, the internal transcribed spacer region, and housekeeping genes recA, glnII, and rpoB was used. Nine fast-growing isolates were Mesorhizobium-related; eight strains were identified as M. japonicum and one isolate belonged to M. kowhaii. The only slow-growing isolate was identified as a Bradyrhizobium sp. Two strains, M. japonicum Opo-242 and Bradyrhizobium sp. strain Opo-243, were isolated from the same nodule. Symbiotic genes of these isolates were searched throughout the whole-genome sequences. The common nodABC genes and other symbiotic genes required for plant nodulation and nitrogen fixation were present in the isolate Opo-242. Strain Opo-243 did not contain the principal nod, nif, and fix genes; however, five genes (nodP, nodQ, nifL, nolK, and noeL) affecting the specificity of plant-rhizobia interactions but absent in isolate Opo-242 were detected. Strain Opo-243 could not induce nodules but significantly accelerated the root nodule formation after coinoculation with isolate Opo-242. Thus, we demonstrated that taxonomically different strains of the archaic symbiotic system can be co-microsymbionts infecting the same nodule and promoting the nodulation process due to complementary sets of symbiotic genes.

Chronic oral infection with major periodontal bacteria Tannerella forsythia modulates systemic atherosclerosis risk factors and inflammatory markers.

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Chukkapalli, Sasanka S; Rivera-Kweh, Mercedes F; Velsko, Irina M; Chen, Hao; Zheng, Donghang; Bhattacharyya, Indraneel; Gangula, Pandu R; Lucas, Alexandra R; Kesavalu, Lakshmyya

2015-04-01

Tannerella forsythia is a Gram-negative anaerobic organism that inhabits the subgingival cavity and initiates connective tissue destruction and alveolar bone resorption in periodontal disease (PD). PD is a chronic immunoinflammatory disease and has been linked to several systemic diseases including atherosclerosis. This study evaluated the effects of a chronic oral infection with T. forsythia ATCC 43037 on the induction of PD, inflammatory markers and atherosclerosis risk factors in hyperlipidemic ApoE(null) mice. Mice were orally infected for 12 and 24 weeks prior to euthanasia. Bacterial colonization of the oral cavity and bacteremia was confirmed via isolation of genomic DNA from oral plaque and tissues. Oral infection elicited significantly elevated levels of serum IgG and IgM antibodies and alveolar bone resorption compared to control mice. Tannerella forsythia-infected mice had increased serum amyloid A, and significantly reduced serum nitric oxide when compared to controls. Tannerella forsythia chronic infection also significantly increased serum lipoproteins suggesting altered cholesterol metabolism and potential for aortic inflammation. Despite enhanced acute phase reactants and altered lipid profiles, T. forsythia infection was associated with decreased aortic plaque. This study investigates the potential of a known periodontal bacterial pathogen found in atherosclerotic plaque in humans to accelerate atherosclerosis in hyperlipdemic mice. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

[Challenges of lopinavir/ritonavir in the chronicity of human immunodeficiency virus infection].

Science.gov (United States)

Aguirrebengoa, Koldo

2014-11-01

Combination antiretroviral therapy (ART) has increased patient survival, which is currently similar to that of the general population in western countries. However, ART is unable to completely restore normal health, given the persistence of chronic immune activation. Human immunodeficiency virus (HIV) infection has become a chronic disease and 50% of patients will soon be older than 50 years. Currently, there is a debate on the possibility of accelerated aging in the HIV-infected population. An overlap has been observed between chronic inflammation, age-related comorbidities, lifestyle, and the long-term toxicity of ART. ART-related toxicity can encourage the development of comorbidities, especially cardiovascular and renal complications, while toxicity-especially that of thymidine analogs-can also contribute to inflammation and aging. Evidence is available on simplification strategies with boosted protease inhibitor monotherapy aiming to avoid or reduce potential or demonstrated toxicity. Currently, studies are underway of dual therapy strategies with lopinavir/ritonavir (LPV/r) with distinct antiretroviral agents. The studies with the largest samples are those with raltegravir and lamivudine. The GARDEL trial has demonstrated that dual therapy with LPV/r plus a generic drug such as lamivudine is non-inferior to triple therapy in treatment- naïve patients. All of the above indicates the response to the challenge posed to LPV/r by the chronic phase of the disease and by the need to reduce costs. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

Characterization of glutathione peroxidase diversity in the symbiotic sea anemone Anemonia viridis.

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Pey, Alexis; Zamoum, Thamilla; Christen, Richard; Merle, Pierre-Laurent; Furla, Paola

2017-01-01

Cnidarians living in symbiosis with photosynthetic dinoflagellates (commonly named zooxanthellae) are exposed to high concentrations of reactive oxygen species (ROS) upon illumination. To quench ROS production, both the cnidarian host and zooxanthellae express a full suite of antioxidant enzymes. Studying antioxidative balance is therefore crucial to understanding how symbiotic cnidarians cope with ROS production. We characterized glutathione peroxidases (GPx) in the symbiotic cnidarian Anemonia viridis by analysis of their isoform diversity, their activity distribution in the three cellular compartments (ectoderm, endoderm and zooxanthellae) and their involvement in the response to thermal stress. We identified a GPx repertoire through a phylogenetic analysis showing 7 GPx transcripts belonging to the A. viridis host and 4 GPx transcripts strongly related to Symbiodinium sp. The biochemical approach, used for the first time with a cnidarian species, allowed the identification of GPx activity in the three cellular compartments and in the animal mitochondrial fraction, and revealed a high GPx electrophoretic diversity. The symbiotic lifestyle of zooxanthellae requires more GPx activity and diversity than that of free-living species. Heat stress induced no modification of GPx activities. We highlight a high GPx diversity in A. viridis tissues by genomic and biochemical approaches. GPx activities represent an overall constitutive enzymatic pattern inherent to symbiotic lifestyle adaptation. This work allows the characterization of the GPx family in a symbiotic cnidarian and establishes a foundation for future studies of GPx in symbiotic cnidarians. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

Terbinafine-loaded wound dressing for chronic superficial fungal infections.

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Paskiabi, Farnoush Asghari; Bonakdar, Shahin; Shokrgozar, Mohammad Ali; Imani, Mohammad; Jahanshiri, Zahra; Shams-Ghahfarokhi, Masoomeh; Razzaghi-Abyaneh, Mehdi

2017-04-01

In spite of developing new drugs and modern formulations, the treatments of chronic fungal infections are still challenging. Fibrous wound dressings are new suggestions for the treatment of chronic superficial infections. In the present study, we formulated an antifungal agent, terbinafine hydrochloride (TFH), which is a hydrophobic drug, in wound dressings prepared by electrospun polycaprolactone, polycaprolactone/gelatin (50:50 w/w) and gelatin. To obtain more water-stable meshes, the preparations were treated by glutaraldehyde and their properties were determined before and after treatment. The morphology of fibrous meshes was observed by scanning electron microscopy. Drug loading efficiency and release rate were measured by high performance liquid chromatography (HPLC) and the release rate was monitored for 144h. Antifungal tests were performed on Trichophyton mentagrophytes, Aspergillus fumigatus and Candida albicans cultured on Muller-Hinton agar. The toxicity of the meshes was measured after 24h and 14days by MTT assay. Terbinafine loading of polycaprolactone/gelatin (50:50) was 100% and it released the highest amount of TFH too. In antifungal tests, all samples were able to hinderT. mentagrophytes and A. fumigatus but not C. albicans growth among them, polycaprolactone fibers made the largest inhibition zone. In MTT assay, none of prepared samples showed toxicity against L929 cells. Teken together, the prepared TFH-loaded PCL/gelatin electrospun meshes were able to release TFH slowly and in a steady state in time. With respect to no obvious cytotoxicity in MTT assay and stong antifungal activity toward T. mentagrophytesin vitro, these TFH-based meshes could be considered as potential candidates in clinical application as wound dressing for treatment of chronic dermatophytosis. Copyright © 2016 Elsevier B.V. All rights reserved.

Chronic Respiratory Infection in Patients with Chronic Obstructive Pulmonary Disease: What Is the Role of Antibiotics?

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Miravitlles, Marc; Anzueto, Antonio

2017-06-23

Chronic infections are associated with exacerbation in patients with chronic obstructive pulmonary disease (COPD). The major objective of the management of these patients is the prevention and effective treatment of exacerbations. Patients that have increased sputum production, associated with purulence and worsening shortness of breath, are the ones that will benefit from antibiotic therapy. It is important to give the appropriate antibiotic therapy to prevent treatment failure, relapse, and the emergence of resistant pathogens. In some patients, systemic corticosteroids are also indicated to improve symptoms. In order to identify which patients are more likely to benefit from these therapies, clinical guidelines recommend stratifying patients based on their risk factor associated with poor outcome or recurrence. It has been identified that patients with more severe disease, recurrent infection and presence of purulent sputum are the ones that will be more likely to benefit from this therapy. Another approach related to disease prevention could be the use of prophylactic antibiotics during steady state condition. Some studies have evaluated the continuous or the intermittent use of antibiotics in order to prevent exacerbations. Due to increased bacterial resistance to antibiotics and the presence of side effects, several antibiotics have been developed to be nebulized for both treatment and prevention of acute exacerbations. There is a need to design long-term studies to evaluate these interventions in the natural history of the disease. The purpose of this publication is to review our understanding of the role of bacterial infection in patients with COPD exacerbation, the role of antibiotics, and future interventions.

Progression of chronic pulmonary tuberculosis in mice intravenously infected with ethambutol resistant Mycobacterium tuberculosis

Directory of Open Access Journals (Sweden)

Srivastava S

2008-01-01

Full Text Available Purpose: Ethambutol (EMB is an important first line drug, however little information on its molecular mechanism of resistance and pathogenicity of resistant isolates is available. Present work was designed to study virulence of the EMB resistant M. tuberculosis strains and the host responses in-vivo on infection of EMB resistant M. tuberculosis using Balb/c mouse model of infection. Methods: Three groups of Balb/c mice (female, age 4-6 wk; 21 mice in each group were infected intravenously with 106 CFU of M. tuberculosis H37Rv and two EMB resistant clinical isolates. Age and sex matched control animals were mock inoculated with Middlebrook 7H9 broth alone. At 10, 20, 30, 40, 50, 60, and 70 days post-infection three animals from each group were sacrificed by cervical dislocation and lung tissue was collected for further analysis. Results: Infection with EMB resistant M. tuberculosis led to progressive and chronic disease with significantly high bacillary load (p=0.02. Massive infiltration and exacerbated lung pathology with increased expression of IFN-γ and TNF-α was observed in lungs of mice infected with EMB resistant strains. The present study suggests that infection with EMB resistant M. tuberculosis leads to chronic infection with subsequent loss of lung function, bacterial persistence with elevated expression of TNF-α resulting in increased lung pathology. Conclusion: These findings highlight that EMB resistant M. tuberculosis regulates host immune response differentially and its pathogenicity is different from drug sensitive strains of M. tuberculosis.

PCR for diagnosis of male Trichomonas vaginalis infection with chronic prostatitis and urethritis.

Science.gov (United States)

Lee, Jong Jin; Moon, Hong Sang; Lee, Tchun Yong; Hwang, Hwan Sik; Ahn, Myoung-Hee; Ryu, Jae-Sook

2012-06-01

The aim of this study was to assess the usefulness of PCR for diagnosis of Trichomonas vaginalis infection among male patients with chronic recurrent prostatitis and urethritis. Between June 2001 and December 2003, a total of 33 patients visited the Department of Urology, Hanyang University Guri Hospital and were examined for T. vaginalis infection by PCR and culture in TYM medium. For the PCR, we used primers based on a repetitive sequence cloned from T. vaginalis (TV-E650). Voided bladder urine (VB1 and VB3) was sampled from 33 men with symptoms of lower urinary tract infection (urethral charge, residual urine sensation, and frequency). Culture failed to detect any T. vaginalis infection whereas PCR identified 7 cases of trichomoniasis (21.2%). Five of the 7 cases had been diagnosed with prostatitis and 2 with urethritis. PCR for the 5 prostatitis cases yielded a positive 330 bp band from bothVB1 and VB3, whereas positive results were only obtained from VB1 for the 2 urethritis patients. We showed that the PCR method could detect T. vaginalis when there was only 1 T. vaginalis cell per PCR mixture. Our results strongly support the usefulness of PCR on urine samples for detecting T. vaginalis in chronic prostatitis and urethritis patients.

Experimental chronic Pseudomonas aeruginosa lung infection in rats. Non-specific stimulation with LPS reduces lethality as efficiently as specific immunization

DEFF Research Database (Denmark)

Lange, K H; Hougen, H P; Høiby, N

1995-01-01

In a rat model of chronic Pseudomonas aeruginosa lung infection mimicking cystic fibrosis, we investigated the possibility of preventing chronic lung inflammation or decreasing the progression of the infection. We compared the lethality, pathology, bacterial clearance, and immunogenicity after...... with either E. coli LPS or P. aeruginosa sonicate. Four and two weeks prior to challenge other rats were vaccinated with either E. coli LPS or P. aeruginosa sonicate. Controls did not receive any stimulation or vaccination. The lethality after challenge was lower in rats stimulated with E. coli LPS (p = 0...... but not to prevent the chronic P. aeruginosa lung infection and inflammation caused by alginate-embedded bacteria....

The undiagnosed chronically-infected HCV population in France. Implications for expanded testing recommendations in 2014.

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Cécile Brouard

Full Text Available Recent HCV therapeutic advances make effective screening crucial for potential HCV eradication. To identify the target population for a possible population-based screening strategy to complement current risk-based testing in France, we aimed to estimate the number of adults with undiagnosed chronic HCV infection and age and gender distribution at two time points: 2004 and 2014.A model taking into account mortality, HCV incidence and diagnosis rates was applied to the 2004 national seroprevalence survey.In 2014, an estimated 74,102 individuals aged 18 to 80 were undiagnosed for chronic HCV infection (plausible interval: 64,920-83,283 compared with 100,868 [95%CI: 58,534-143,202] in 2004. Men aged 18-59 represented approximately half of the undiagnosed population in 2014. The proportion of undiagnosed individuals in 2004 (43% varied from 21.9% to 74.1% in the 1945-1965 and 1924-1944 birth cohorts. Consequently, age and gender distributions between the chronically-infected (diagnosed and undiagnosed and undiagnosed HCV populations were different, the 1945-1965 birth cohort representing 48.9% and 24.7%, respectively.Many individuals were still undiagnosed in 2014 despite a marked reduction with respect to 2004. The present work contributed to the 2014 recommendation of a new French complementary screening strategy, consisting in one-time simultaneous HCV, HBV and HIV testing in men aged 18-60. Further studies are needed to assess the cost-effectiveness and feasibility of such a strategy. We also demonstrated that data on the undiagnosed HCV population are crucial to help adapt testing strategies, as the features of the chronically-infected HCV population are very distinct.

Infrared studies of symbiotic stars

International Nuclear Information System (INIS)

Allen, D.A.

1982-01-01

Infrared photometry and spectroscopy of symbiotic stars is reviewed. It is shown that at wavelengths beyond 1 μm these systems are generally dominated by the cool star's photosphere and, indeed, are indistinguishable from ordinary late-type giants. About 25% of symbiotic stars exhibit additional emission due to circumstellar dust. Most of the dusty systems probably involve Mira variables, the dust forming in the atmospheres of the Miras. In a few cases the dust is much cooler and the cool component hotter; the dust must then form in distant gas shielded from the hot component, perhaps by an accretion disk. Spectroscopy at 2 μm can be used to spectral type the cool components, even in the presence of some dust emission. Distances may thereby be estimated, though with some uncertainty. Spectroscopy at longer wavelengths reveals information about the dust itself. In most cases this dust appears to include silicate grains, which form in the oxygen-rich envelope of an M star. In the case of HD 33036, however, different emission features are found which suggest a carbon-rich environment. (Auth.)

Causative Role of Sexually Transmitted Infections in the Development of Chronic Cystitis Complicated with Leukoplakia of the Bladder

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Alexander I. Neymark, PhD, ScD

2012-09-01

Full Text Available The objective of this study was the investigation of the influence of chlamydial, mycoplasmal and trichomonas infection on the development of urinary bladder leukoplakia. The article presents the results of the examination of women with chronic cystitis complicated with leukoplakia of the bladder, and associated with concomitant sexually transmitted infections, including the results of culture analysis of the cervical canal content and urinary bladder biopsy samples, as well as molecular-biological analyses confirming the presence of sexually transmitted infections, pathomorphological characteristics of tissue samples from leukoplakia foci typical for different types of infectious agents. In this study, 60 women with chronic cystitis, complicated with leukoplakia of the bladder and associated with concomitant sexually transmitted infections were examined. Using PCR diagnostics, Mycoplasma hominis and Chlamydia albicans were found to be the most frequently occurring agents, followed by Ureaplasma urealyticum, Chlamydia trachomatis and Trichomonas vaginalis. The results of culture analyses demonstrated that M. hominis and U. urealyticum were prevalent in patients with chronic urinary tract inflammatory processes, followed by Tr. vaginalis. Candida fungi show practically the same frequency of occurrence. The pathomorphological examination of the foci of leukoplakia in the urinary bladder (in 30 subjects demonstrated metaplasia of the transitional epithelium to the stratified pavement squamous epithelium with inflammatory cellular infiltration of the lamina propria in all types of infections. The intensity of the urothelial transformation and stromal inflammatory processes were determined by the type of predominant infection. Pathomorphological characteristics of the foci of leukoplakia correlate with the etiology of chronic inflammation and are relevant for etiological diagnosis and treatment.

Enhancing virus-specific immunity in vivo by combining therapeutic vaccination and PD-L1 blockade in chronic hepadnaviral infection.

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Jia Liu

2014-01-01

Full Text Available Hepatitis B virus (HBV persistence is facilitated by exhaustion of CD8 T cells that express the inhibitory receptor programmed cell death-1 (PD-1. Improvement of the HBV-specific T cell function has been obtained in vitro by inhibiting the PD-1/PD-ligand 1 (PD-L1 interaction. In this study, we examined whether in vivo blockade of the PD-1 pathway enhances virus-specific T cell immunity and leads to the resolution of chronic hepadnaviral infection in the woodchuck model. The woodchuck PD-1 was first cloned, characterized, and its expression patterns on T cells from woodchucks with acute or chronic woodchuck hepatitis virus (WHV infection were investigated. Woodchucks chronically infected with WHV received a combination therapy with nucleoside analogue entecavir (ETV, therapeutic DNA vaccination and woodchuck PD-L1 antibody treatment. The gain of T cell function and the suppression of WHV replication by this therapy were evaluated. We could show that PD-1 expression on CD8 T cells was correlated with WHV viral loads during WHV infection. ETV treatment significantly decreased PD-1 expression on CD8 T cells in chronic carriers. In vivo blockade of PD-1/PD-L1 pathway on CD8 T cells, in combination with ETV treatment and DNA vaccination, potently enhanced the function of virus-specific T cells. Moreover, the combination therapy potently suppressed WHV replication, leading to sustained immunological control of viral infection, anti-WHs antibody development and complete viral clearance in some woodchucks. Our results provide a new approach to improve T cell function in chronic hepatitis B infection, which may be used to design new immunotherapeutic strategies in patients.

Frequency of Hepatitis B and C Co-Infection in Chronic Liver ...

African Journals Online (AJOL)

olayemitoyin

Summary: Hepatitis B (HBsAg) and C (HCV) virus are becoming a significant causative factors in the aetiology of chronic liver disease (CLD) worldwide. However, the information on the frequency of HBsAg and HCV virus co-infection in CLD is sparsely reported in Nigeria. In this study, we assessed the frequency of HBsAg ...

A randomized clinical trial on the effectiveness of a symbiotic product to decolonize patients harboring multidrug-resistant Gram-negative bacilli

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Mariana Correa Coelho Salomão

Full Text Available Abstract INTRODUCTION: We aimed to evaluate the effectiveness of a symbiotic product to decolonize the intestinal tract of patients harboring multidrug-resistant (MDR Gram-negative bacilli and to prevent nosocomial infections. METHODS: This was a randomized, double blind, placebo-controlled clinical trial, conducted in a tertiary-care university hospital. All adult hospitalized patients with a positive clinical culture and a positive rectal swab for any MDR Gram-negative bacilli were potentially eligible. Exclusion criteria were pregnancy, immunosuppression, and bowel obstruction/perforation. The intervention consisted of administering a symbiotic product (Lactobacillus bulgaricus, Lactobacillus rhamnosus, and fructo-oligosaccharides twice a day for seven days via the oral/enteral route. RESULTS: Between August 1, 2012 and December 22, 2013, 116 of 275 eligible patients were allocated to treatment (n=57 and placebo (n=59. Overall, 101 patients received at least four doses of the study products and were included in the modified intention-to-treat analysis. The primary study outcome, a negative rectal swab for MDR Gram-negative bacilli after treatment, was identified in 16.7% (8/48 and 20.7% (11/53 of patients in the experimental and placebo group, respectively (p=0.60. The secondary outcome, the combined incidence of nosocomial respiratory and urinary tract infections, was 37.5% (18/48 in the experimental group versus 22.6% (12/53 in the control group (adjusted odds ratio: 1.95, 95% confidence interval: 0.69-5.50, p=0.21. Length of stay after the beginning of the intervention, incidence of adverse events, and in-hospital mortality rates were similar in both study groups. CONCLUSIONS: Under the present study conditions, symbiotic administration was not effective for decolonizing hospitalized patients harboring MDR Gram-negative bacilli.

Comparative efficacy of some quinolones and doxycycline against chronic infection of brucella melitensis 16M in balb/c mice

International Nuclear Information System (INIS)

Safi, M.; Albalaa, B.; Mahmoud, N.H.; Mariri, A.A.

2016-01-01

This study was under taken to observe various treatment methods for brucellosis caused by Brucella melitensis . The effect of therapeutic regimens with ciprofloxacin, ofloxacin and levofloxacin alone or in combination with doxycycline was assessed against B. melitensis chronic infection using 200 mice. Doxycycline alone or in combination with ciprofloxacin was significantly found to reduce the infection till 135 days post-infection (p<0.0001). Moreover, doxycycline was more effective than ciprofloxacin and ofloxacin 135 days post-infection (p = 0.04 and p = 0.02, respectively). However, treatment with quinolone-doxycycline combinations revealed synergistic effects as they were able to reduce the splenic cell forming unit (CFU) from day 45 post-infection. Similarly, doxycycline treatment reduced the splenic colony forming unit (CFU) from day 90 post-infection. In conclusion, doxycycline seems to be the most effective agent against Brucella chronic infection. (author)

An update on probiotics, prebiotics and symbiotics in clinical nutrition.

Science.gov (United States)

Olveira, Gabriel; González-Molero, Inmaculada

2016-11-01

The concept of prebiotics, probiotics, and symbiotics and their use in different situations of daily clinical practice related to clinical nutrition is reviewed, as well as their role in the treatment/prevention of diarrhea (acute, induced by antibiotics, secondary to radiotherapy), inflammatory bowel disease (ulcerative colitis and pouchitis), in colonic health (constipation, irritable bowel), in liver disease (steatosis and minimum encephalopathy), and in intensive care, surgical, and liver transplantation. While their effectiveness for preventing antibiotic-induced diarrhea and pouchitis in ulcerative colitis appears to be shown, additional studies are needed to establish recommendations in most clinical settings. The risk of infection associated to use of probiotics is relatively low; however, there are selected groups of patients in whom they should be used with caution (as jejunum infusion). Copyright © 2016 SEEN. Publicado por Elsevier España, S.L.U. All rights reserved.

Helicobacter Pylori infection of the gallbladder and the risk of chronic cholecystitis and cholelithiasis: A systematic review and meta-analysis.

Science.gov (United States)

Cen, Li; Pan, Jiaqi; Zhou, Boyan; Yu, Chaohui; Li, Youming; Chen, Weixing; Shen, Zhe

2018-02-01

Helicobacter pylori is coexisted with various diseases, including chronic gastritis, ulcer, and gastric cancer. Besides, chronic cholecystitis and cholelithiasis are extremely widespread over the world, which are considered as high health-care cost burdens of digestive diseases. Epidemiologic evidence on Helicobacter pylori infection in gallbladder increasing the risk of biliary diseases has been contradictory. Conduct a meta-analysis of overall studies and investigate an association between Helicobacter pylori infection of the gallbladder with chronic cholecystitis/cholelithiasis. We used PubMed, EMBASE, and Cochrane library databases to identify all published studies before August 2017. Pooled odds ratios (OR) and corresponding 95% confidence intervals (CIs) were obtained using the random effects model. Heterogeneity, sensitivity, and stratified analyses were also performed. Eighteen studies involving 1544 participants and 1061 biliary cases with chronic cholecystitis/cholelithiasis were included. Helicobacter pylori infection of the gallbladder was significantly associated with an increased risk of chronic cholecystitis and cholecystitis (OR = 3.022; 95% CI, 1.897-4.815; I 2  = 20.1%). In addition, country-based subgroup analysis also showed a positive association between Helicobacter pylori positivity and chronic cholecystitis/cholelithiasis risk. The ORs (95% CIs) for Asian and non-Asian region studies were 3.75 (1.83-7.71) and 2.25 (1.29-3.89), respectively. This meta-analysis suggests that infection of the gallbladder with Helicobacter pylori is closely related to an increased risk of chronic cholecystitis and cholelithiasis. © 2017 John Wiley & Sons Ltd.

Infection dynamic of symbiotic bacteria in the pea aphid Acyrthosiphon pisum gut and host immune response at the early steps in the infection process.

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François Renoz

Full Text Available In addition to its obligatory symbiont Buchnera aphidicola, the pea aphid Acyrthosiphon pisum can harbor several facultative bacterial symbionts which can be mutualistic in the context of various ecological interactions. Belonging to a genus where many members have been described as pathogen in invertebrates, Serratia symbiotica is one of the most common facultative partners found in aphids. The recent discovery of strains able to grow outside their host allowed us to simulate environmental acquisition of symbiotic bacteria by aphids. Here, we performed an experiment to characterize the A. pisum response to the ingestion of the free-living S. symbiotica CWBI-2.3T in comparison to the ingestion of the pathogenic Serratia marcescens Db11 at the early steps in the infection process. We found that, while S. marcescens Db11 killed the aphids within a few days, S. symbiotica CWBI-2.3T did not affect host survival and colonized the whole digestive tract within a few days. Gene expression analysis of immune genes suggests that S. symbiotica CWBI-2.3T did not trigger an immune reaction, while S. marcescens Db11 did, and supports the hypothesis of a fine-tuning of the host immune response set-up for fighting pathogens while maintaining mutualistic partners. Our results also suggest that the lysosomal system and the JNK pathway are possibly involved in the regulation of invasive bacteria in aphids and that the activation of the JNK pathway is IMD-independent in the pea aphid.

Genetic Diversity and Symbiotic Efficiency of Indigenous Common Bean Rhizobia in Croatia

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Ines Pohajda

2016-01-01

Full Text Available Nodule bacteria (rhizobia in symbiotic associations with legumes enable considerable entries of biologically fixed nitrogen into soil. Efforts are therefore made to intensify the natural process of symbiotic nitrogen fixation by legume inoculation. Studies of field populationsof rhizobia open up the possibility to preserve and probably exploit some indigenous strains with hidden symbiotic or ecological potentials. The main aim of the present study is to determine genetic diversity of common bean rhizobia isolated from different field sites in central Croatia and to evaluate their symbiotic efficiency and compatibility with host plants. The isolation procedure revealed that most soil samples contained no indigenous common bean rhizobia. The results indicate that the cropping history had a significant impact on the presence of indigenous strains. Although all isolates were found to belong to species Rhizobium leguminosarum, significant genetic diversity at the strain level was determined. Application of both random amplifi cation of polymorphic DNA (RAPD and enterobacterial repetitive intergenic consensus–polymerase chain reaction (ERIC-PCR methods resulted in similar grouping of strains. Symbiotic efficiency of indigenous rhizobia as well as their compatibility with two commonly grown bean varieties were tested in field experiments. Application of indigenous rhizobial strains as inoculants resulted in significantly different values of nodulation, seed yield as well as plant nitrogen and seed protein contents. The most abundant nodulation and the highest plant nitrogen and protein contents were determined in plants inoculated with R. leguminosarum strains S17/2 and S21/6. Although, in general, the inoculation had a positive impact on seed yield, differences depending on the applied strain were not determined. The overall results show the high degree of symbiotic efficiency of the specific indigenous strain S21/6. These results indicate different

Genetic Diversity and Symbiotic Efficiency of Indigenous Common Bean Rhizobia in Croatia.

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Pohajda, Ines; Babić, Katarina Huić; Rajnović, Ivana; Kajić, Sanja; Sikora, Sanja

2016-12-01

Nodule bacteria (rhizobia) in symbiotic associations with legumes enable considerable entries of biologically fixed nitrogen into soil. Efforts are therefore made to intensify the natural process of symbiotic nitrogen fixation by legume inoculation. Studies of field populations of rhizobia open up the possibility to preserve and probably exploit some indigenous strains with hidden symbiotic or ecological potentials. The main aim of the present study is to determine genetic diversity of common bean rhizobia isolated from different field sites in central Croatia and to evaluate their symbiotic efficiency and compatibility with host plants. The isolation procedure revealed that most soil samples contained no indigenous common bean rhizobia. The results indicate that the cropping history had a significant impact on the presence of indigenous strains. Although all isolates were found to belong to species Rhizobium leguminosarum , significant genetic diversity at the strain level was determined. Application of both random amplification of polymorphic DNA (RAPD) and enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC- -PCR) methods resulted in similar grouping of strains. Symbiotic efficiency of indigenous rhizobia as well as their compatibility with two commonly grown bean varieties were tested in field experiments. Application of indigenous rhizobial strains as inoculants resulted in significantly different values of nodulation, seed yield as well as plant nitrogen and seed protein contents. The most abundant nodulation and the highest plant nitrogen and protein contents were determined in plants inoculated with R. leguminosarum strains S 17/2 and S 21/6 . Although, in general, the inoculation had a positive impact on seed yield, differences depending on the applied strain were not determined. The overall results show the high degree of symbiotic efficiency of the specific indigenous strain S 21/6 . These results indicate different symbiotic

Molecular identification of chronic bee paralysis virus infection in Apis mellifera colonies in Japan.

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Morimoto, Tomomi; Kojima, Yuriko; Yoshiyama, Mikio; Kimura, Kiyoshi; Yang, Bu; Kadowaki, Tatsuhiko

2012-07-01

Chronic bee paralysis virus (CBPV) infection causes chronic paralysis and loss of workers in honey bee colonies around the world. Although CBPV shows a worldwide distribution, it had not been molecularly detected in Japan. Our investigation of Apis mellifera and Apis cerana japonica colonies with RT-PCR has revealed CBPV infection in A. mellifera but not A. c. japonica colonies in Japan. The prevalence of CBPV is low compared with that of other viruses: deformed wing virus (DWV), black queen cell virus (BQCV), Israel acute paralysis virus (IAPV), and sac brood virus (SBV), previously reported in Japan. Because of its low prevalence (5.6%) in A. mellifera colonies, the incidence of colony losses by CBPV infection must be sporadic in Japan. The presence of the (-) strand RNA in dying workers suggests that CBPV infection and replication may contribute to their symptoms. Phylogenetic analysis demonstrates a geographic separation of Japanese isolates from European, Uruguayan, and mainland US isolates. The lack of major exchange of honey bees between Europe/mainland US and Japan for the recent 26 years (1985-2010) may have resulted in the geographic separation of Japanese CBPV isolates.

T-cell homeostasis in chronic HCV-infected patients treated with interferon and ribavirin or an interferon-free regimen

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Hartling, Hans Jakob; Birch, Carsten; Gaardbo, Julie C

2015-01-01

Direct-acting antiviral has replaced pegylated interferon-α and ribavirin-based treatment in the treatment of chronic hepatitis C virus (HCV) infection. While interferon-α is immune modulating and causes lymphopenia, interferon-free regimens seem to be well-tolerated. This study aimed to compare T......-cell homeostasis before, during, and after HCV treatment with or without interferon-α in patients with chronic HCV infection. A total of 20 patients with chronic HCV infection were treated with pegylated interferon-α and ribavirin, and six patients were treated with an interferon-free regimen. All patients were...... compared to prior treatment values. Finally, a proportion of CD8+ effector memory was lower while proportion of apoptotic T cells was higher after sustained virologic response compared to prior treatment. Despite lymphopenia during interferon, alterations in T-cell homeostasis during treatment were...

Radio emission from symbiotic stars: a binary model

International Nuclear Information System (INIS)

Taylor, A.R.; Seaquist, E.R.

1985-01-01

The authors examine a binary model for symbiotic stars to account for their radio properties. The system is comprised of a cool, mass-losing star and a hot companion. Radio emission arises in the portion of the stellar wind photo-ionized by the hot star. Computer simulations for the case of uniform mass loss at constant velocity show that when less than half the wind is ionized, optically thick spectral indices greater than +0.6 are produced. Model fits to radio spectra allow the binary separation, wind density and ionizing photon luminosity to be calculated. They apply the model to the symbiotic star H1-36. (orig.)

Investigating Tactile Stimulation in Symbiotic Systems

DEFF Research Database (Denmark)

Orso, Valeria; Mazza, Renato; Gamberini, Luciano

2017-01-01

The core characteristics of tactile stimuli, i.e., recognition reliability and tolerance to ambient interference, make them an ideal candidate to be integrated into a symbiotic system. The selection of the appropriate stimulation is indeed important in order not to hinder the interaction from...

Population dynamics of Vibrio fischeri during infection of Euprymna scolopes.

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McCann, Jessica; Stabb, Eric V; Millikan, Deborah S; Ruby, Edward G

2003-10-01

The luminous bacterium Vibrio fischeri colonizes a specialized light-emitting organ within its squid host, Euprymna scolopes. Newly hatched juvenile squid must acquire their symbiont from ambient seawater, where the bacteria are present at low concentrations. To understand the population dynamics of V. fischeri during colonization more fully, we used mini-Tn7 transposons to mark bacteria with antibiotic resistance so that the growth of their progeny could be monitored. When grown in culture, there was no detectable metabolic burden on V. fischeri cells carrying the transposon, which inserts in single copy in a specific intergenic region of the V. fischeri genome. Strains marked with mini-Tn7 also appeared to be equivalent to the wild type in their ability to infect and multiply within the host during coinoculation experiments. Studies of the early stages of colonization suggested that only a few bacteria became associated with symbiotic tissue when animals were exposed for a discrete period (3 h) to an inoculum of V. fischeri cells equivalent to natural population levels; nevertheless, all these hosts became infected. When three differentially marked strains of V. fischeri were coincubated with juvenile squid, the number of strains recovered from an individual symbiotic organ was directly dependent on the size of the inoculum. Further, these results indicated that, when exposed to low numbers of V. fischeri, the host may become colonized by only one or a few bacterial cells, suggesting that symbiotic infection is highly efficient.

Molecular and biochemical analysis of symbiotic plant receptor kinase complexes

Energy Technology Data Exchange (ETDEWEB)

Cook, Douglas R; Riely, Brendan K

2010-09-01

DE-FG02-01ER15200 was a 36-month project, initiated on Sept 1, 2005 and extended with a one-year no cost extension to August 31, 2009. During the project period we published seven manuscripts (2 in review). Including the prior project period (2002-2005) we published 12 manuscripts in journals that include Science, PNAS, The Plant Cell, Plant Journal, Plant Physiology, and MPMI. The primary focus of this work was to further elucidate the function of the Nod factor signaling pathway that is involved in initiation of the legume-rhizobium symbiosis and in particular to explore the relationship between receptor kinase-like proteins and downstream effectors of symbiotic development. During the project period we have map-base cloned two additional players in symbiotic development, including an ERF transcription factor and an ethylene pathway gene (EIN2) that negatively regulates symbiotic signaling; we have also further characterized the subcellular distribution and function of a nuclear-localized symbiosis-specific ion channel, DMI1. The major outcome of the work has been the development of systems for exploring and validating protein-protein interactions that connect symbiotic receptor-like proteins to downstream responses. In this regard, we have developed both homologous (i.e., in planta) and heterologous (i.e., in yeast) systems to test protein interactions. Using yeast 2-hybrid screens we isolated the only known interactor of the nuclear-localized calcium-responsive kinase DMI3. We have also used yeast 2-hybrid methodology to identify interactions between symbiotic signaling proteins and certain RopGTPase/RopGEF proteins that regulate root hair polar growth. More important to the long-term goals of our work, we have established a TAP tagging system that identifies in planta interactions based on co-immuno precipitation and mass spectrometry. The validity of this approach has been shown using known interactors that either co-iummnoprecipate (i.e., remorin) or co

The Role of Chronic Mesh Infection in Delayed-Onset Vaginal Mesh Complications or Recurrent Urinary Tract Infections: Results From Explanted Mesh Cultures.

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Mellano, Erin M; Nakamura, Leah Y; Choi, Judy M; Kang, Diana C; Grisales, Tamara; Raz, Shlomo; Rodriguez, Larissa V

2016-01-01

Vaginal mesh complications necessitating excision are increasingly prevalent. We aim to study whether subclinical chronically infected mesh contributes to the development of delayed-onset mesh complications or recurrent urinary tract infections (UTIs). Women undergoing mesh removal from August 2013 through May 2014 were identified by surgical code for vaginal mesh removal. Only women undergoing removal of anti-incontinence mesh were included. Exclusion criteria included any women undergoing simultaneous prolapse mesh removal. We abstracted preoperative and postoperative information from the medical record and compared mesh culture results from patients with and without mesh extrusion, de novo recurrent UTIs, and delayed-onset pain. One hundred seven women with only anti-incontinence mesh removed were included in the analysis. Onset of complications after mesh placement was within the first 6 months in 70 (65%) of 107 and delayed (≥6 months) in 37 (35%) of 107. A positive culture from the explanted mesh was obtained from 82 (77%) of 107 patients, and 40 (37%) of 107 were positive with potential pathogens. There were no significant differences in culture results when comparing patients with delayed-onset versus immediate pain, extrusion with no extrusion, and de novo recurrent UTIs with no infections. In this large cohort of patients with mesh removed for a diverse array of complications, cultures of the explanted vaginal mesh demonstrate frequent low-density bacterial colonization. We found no differences in culture results from women with delayed-onset pain versus acute pain, vaginal mesh extrusions versus no extrusions, or recurrent UTIs using standard culture methods. Chronic prosthetic infections in other areas of medicine are associated with bacterial biofilms, which are resistant to typical culture techniques. Further studies using culture-independent methods are needed to investigate the potential role of chronic bacterial infections in delayed vaginal mesh

Seroprevalence of chronic hepatitis B virus infection and prior immunity in immigrants and refugees: a systematic review and meta-analysis.

Science.gov (United States)

Rossi, Carmine; Shrier, Ian; Marshall, Lee; Cnossen, Sonya; Schwartzman, Kevin; Klein, Marina B; Schwarzer, Guido; Greenaway, Chris

2012-01-01

International migrants experience increased mortality from hepatocellular carcinoma compared to host populations, largely due to undetected chronic hepatitis B infection (HBV). We conducted a systematic review of the seroprevalence of chronic HBV and prior immunity in migrants arriving in low HBV prevalence countries to identify those at highest risk in order to guide disease prevention and control strategies. Medline, Medline In-Process, EMBASE and the Cochrane Database of Systematic Reviews were searched. Studies that reported HBV surface antigen or surface antibodies in migrants were included. The seroprevalence of chronic HBV and prior immunity were pooled by region of origin and immigrant class, using a random-effects model. A random-effects logistic regression was performed to explore heterogeneity. The number of chronically infected migrants in each immigrant-receiving country was estimated using the pooled HBV seroprevalences and country-specific census data. A total of 110 studies, representing 209,822 immigrants and refugees were included. The overall pooled seroprevalence of infection was 7.2% (95% CI: 6.3%-8.2%) and the seroprevalence of prior immunity was 39.7% (95% CI: 35.7%-43.9%). HBV seroprevalence differed significantly by region of origin. Migrants from East Asia and Sub-Saharan Africa were at highest risk and migrants from Eastern Europe were at an intermediate risk of infection. Region of origin, refugee status and decade of study were independently associated with infection in the adjusted random-effects logistic model. Almost 3.5 million migrants (95% CI: 2.8-4.5 million) are estimated to be chronically infected with HBV. The seroprevalence of chronic HBV infection is high in migrants from most world regions, particularly among those from East Asia, Sub-Saharan Africa and Eastern Europe, and more than 50% were found to be susceptible to HBV. Targeted screening and vaccination of international migrants can become an important component of HBV

Seroprevalence of chronic hepatitis B virus infection and prior immunity in immigrants and refugees: a systematic review and meta-analysis.

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Carmine Rossi

Full Text Available BACKGROUND: International migrants experience increased mortality from hepatocellular carcinoma compared to host populations, largely due to undetected chronic hepatitis B infection (HBV. We conducted a systematic review of the seroprevalence of chronic HBV and prior immunity in migrants arriving in low HBV prevalence countries to identify those at highest risk in order to guide disease prevention and control strategies. METHODS AND FINDINGS: Medline, Medline In-Process, EMBASE and the Cochrane Database of Systematic Reviews were searched. Studies that reported HBV surface antigen or surface antibodies in migrants were included. The seroprevalence of chronic HBV and prior immunity were pooled by region of origin and immigrant class, using a random-effects model. A random-effects logistic regression was performed to explore heterogeneity. The number of chronically infected migrants in each immigrant-receiving country was estimated using the pooled HBV seroprevalences and country-specific census data. A total of 110 studies, representing 209,822 immigrants and refugees were included. The overall pooled seroprevalence of infection was 7.2% (95% CI: 6.3%-8.2% and the seroprevalence of prior immunity was 39.7% (95% CI: 35.7%-43.9%. HBV seroprevalence differed significantly by region of origin. Migrants from East Asia and Sub-Saharan Africa were at highest risk and migrants from Eastern Europe were at an intermediate risk of infection. Region of origin, refugee status and decade of study were independently associated with infection in the adjusted random-effects logistic model. Almost 3.5 million migrants (95% CI: 2.8-4.5 million are estimated to be chronically infected with HBV. CONCLUSIONS: The seroprevalence of chronic HBV infection is high in migrants from most world regions, particularly among those from East Asia, Sub-Saharan Africa and Eastern Europe, and more than 50% were found to be susceptible to HBV. Targeted screening and vaccination of

18F-FDG uptake in the stomach on screening PET/CT: value for predicting Helicobacter pylori infection and chronic atrophic gastritis

International Nuclear Information System (INIS)

Kobayashi, Shigeki; Ogura, Mayumi; Suzawa, Naohisa; Horiki, Noriyuki; Katsurahara, Masaki; Ogura, Toru; Sakuma, Hajime

2016-01-01

The aim of this study was to determine the value of 18 F-FDG uptake on screening PET/CT images for the prediction of Helicobacter pylori (H. pylori) infection and chronic atrophic gastritis. Among subjects who underwent 18 F-FDG PET/CT for cancer screening from April 2005 to November 2015, PET/CT images were analyzed in 88 subjects who had gastrointestinal fiberscopy within 6 months. The volumes of interest (VOIs) were placed in the fornix, corpus and antrum of the stomach to determine maximal standardized uptake value (SUVmax) and mean SUV (SUVmean). Receiver operating characteristic curve (ROC) analysis was performed to determine the diagnostic performance of SUV indicators in predicting H. pylori infection and chronic atrophic gastritis. SUV indicators of the stomach were significantly higher in subjects with H. pylori infection than those without (from P < 0.001 to P < 0.05). ROC analysis revealed that SUVmean had the highest performance in predicting H. pylori infection (AUC 0.807) and chronic atrophic gastritis (AUC 0.784). SUVmean exhibited the sensitivity of 86.5 % and the specificity of 70.6 % in predicting H. pylori infection, and the sensitivity of 75.0 % and 78.6 % in predicting chronic atrophic gastritis. Assessment of 18 F-FDG uptake in the stomach reflecting active inflammation is useful in predicting patients with H. pylori infection and subsequent chronic atrophic gastritis which is closely associated with the risk of gastric neoplasms

Symbiotic Activity of Pea (Pisum sativum) after Application of Nod Factors under Field Conditions

OpenAIRE

Siczek, Anna; Lipiec, Jerzy; Wielbo, Jerzy; Kidaj, Dominika; Szarlip, Paweł

2014-01-01

Growth and symbiotic activity of legumes are mediated by Nod factors (LCO, lipo-chitooligosaccharides). To assess the effects of application of Nod factors on symbiotic activity and yield of pea, a two-year field experiment was conducted on a Haplic Luvisol developed from loess. Nod factors were isolated from Rhizobium leguminosarum bv. viciae strain GR09. Pea seeds were treated with the Nod factors (10−11 M) or water (control) before planting. Symbiotic activity was evaluated by measurement...

Histology of chronic gastritis with and without duodenitis in patients with Helicobacter pylori infection.

OpenAIRE

Phull, P S; Price, A B; Stephens, J; Rathbone, B J; Jacyna, M R

1996-01-01

AIM: To compare the histological characteristics of Helicobacter pylori positive chronic gastritis in patients with and without associated duodenitis. METHODS: Gastric mucosal biopsy specimens were obtained from patients undergoing endoscopy for dyspepsia. Severity of gastritis and density of H pylori infection were graded according to the Sydney system. RESULTS: Of the 69 patients studied, 15 had normal histology, 22 had chronic gastritis only (77.3% H pylori positive), 21 had duodenitis (90...

Оptimization of periodontitis treatment in patients with chronic brucellosis infection

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L.A. Soboleva

2010-06-01

Full Text Available For the purpose to determine the clinical pathogenetic efficacy of Cycloferon liniment in the combined therapy of parodontitis in patients with chronic brucellosis medical examination and treatment of 50 patients was carried out. It was established that use of liniment Cycloferon in the combined treatment of patients with pariodontitis against chronic brucellosis allowed to accelerate process of normalization of parameters of lipid peroxidation and antioxidant potential of blood, to decrease infection load (herpes symplex virus I, candida albicans, staphylococcus aureus in parodontal recess and evidence of local inflammation with reduction of activity of tumour necrosis and interleukin 1b, that provided acceleration of recovery processes, lowering in frequency of pariodontitis recurrences

Discovery of a Possible Symbiotic Binary in the Large Magellanic Cloud

Science.gov (United States)

Mathew, Blesson; Reid, Warren A.; Mennickent, R. E.; Banerjee, D. P. K.

2017-12-01

We report the discovery of a possible symbiotic star, in the Large Magellanic Cloud (LMC). The object under consideration here, designated as RP 870, was detected during the course of a comprehensive H$\\alpha$ survey of the LMC by Reid & Parker (2012). The spectrum of RP 870 showed high ionization emission lines of He I, He II and [O III] and molecular absorption bands of TiO $\\lambda$$\\lambda$6180, 7100. The collective signatures of a hot component (high excitation/ionization lines) and of a cool component (TiO molecular bands) are seen in RP 870, from which we propose it as a symbiotic star. Since known symbiotic systems are rare in the LMC, possibly less than a dozen are known, we thought the present detection to be interesting enough to be reported.

IL-35, a hallmark of immune-regulation in cancer progression, chronic infections and inflammatory diseases.

Science.gov (United States)

Teymouri, Manouchehr; Pirro, Matteo; Fallarino, Francesca; Gargaro, Marco; Sahebkar, Amirhosein

2018-03-25

Cytokine members of the IL-12 family have attracted enormous attention in the last few years, with IL-35 being the one of the most attractive-suppressive cytokine. IL-35 is an important mediator of regulatory T cell function. Regulatory T cells play key roles in restoring immune homeostasis after facing challenges such as infection by specific pathogens. Moreover, a crucial role for regulatory T cell populations has been demonstrated in several physiological processes, including establishment of fetal-maternal tolerance, maintenance of self-tolerance and prevention of autoimmune diseases. However, a deleterious involvement of immune regulatory T cells has been documented in specific inhibition of immune responses against tumor cells, promotion of chronic infections and establishment of chronic inflammatory disorders. In this review, we attempt to shed light on the concept of immune-homoeostasis on the aforementioned issues, taking IL-35 as the hallmark of regulatory responses. The dilemma between immune-mediated cancer treatment and inflammation is discussed. Histopathological indications of chronic vs. acute infections are elaborated. Moreover, the evidence that IL-35 requires additional immune-regulatory cytokines, such as IL-10 and TGF-β, to induce effective and maximal anti-inflammatory effects suggest that immune-regulation requires multi-factorial analysis of many immune playmakers rather than a specific immune target. © 2018 UICC.

Chronic Trichuris muris infection causes neoplastic change in the intestine and exacerbates tumour formation in APC min/+ mice.

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Kelly S Hayes

2017-06-01

Full Text Available Incidences of infection-related cancers are on the rise in developing countries where the prevalence of intestinal nematode worm infections are also high. Trichuris muris (T. muris is a murine gut-dwelling nematode that is the direct model for human T. trichiura, one of the major soil-transmitted helminth infections of humans. In order to assess whether chronic infection with T. muris does indeed influence the development of cancer hallmarks, both wild type mice and colon cancer model (APC min/+ mice were infected with this parasite. Parasite infection in wild type mice led to the development of neoplastic change similar to that seen in mice that had been treated with the carcinogen azoxymethane. Additionally, both chronic and acute infection in the APCmin/+ mice led to an enhanced tumour development that was distinct to the site of infection suggesting systemic control. By blocking the parasite induced T regulatory response in these mice, the increase in the number of tumours following infection was abrogated. Thus T. muris infection alone causes an increase in gut pathologies that are known to be markers of cancer but also increases the incidence of tumour formation in a colon cancer model. The influence of parasitic worm infection on the development of cancer may therefore be significant.

Chronic hepatitis B virus infection in Sjögren's syndrome. Prevalence and clinical significance in 603 patients.

Science.gov (United States)

Marcos, Miguel; Alvarez, Fausto; Brito-Zerón, Pilar; Bove, Albert; Perez-De-Lis, Marta; Diaz-Lagares, Candido; Sanchez-Tapias, Jose-Maria; Ramos-Casals, Manuel

2009-06-01

To analyze the prevalence and clinical characteristics of chronic hepatitis B virus (HBV) infection in a large series of patients with Sjögren syndrome (SS). We investigated the prevalence of chronic HBV infection in 603 consecutive patients with SS diagnosed in our department between 1994 and 2008. There were 517 patients with primary SS (482 women and 35 men, with a mean age at the time of fulfillment of the classification criteria of 57 years) and 86 patients with SS associated with chronic HCV infection (66 women and 20 men, with a mean age at the time of fulfillment of the classification criteria of 65 years). All patients fulfilled 4 or more of the 1993 European Community Study Group criteria for SS. The presence of HBsAg+ was detected in five (0.83%) of the 603 patients with SS. All HBsAg+ patients had primary SS. No patient with HCV-related SS had HBV coinfection. There were 4 women and 1 man, with a mean age at diagnosis of primary SS of 65 years (range 31 to 89 years). All patients showed sicca and systemic involvement. The main extraglandular feature was articular involvement in 5 (100%) patients (including arthritis in two). The main immunologic features were RF in 4 (80%) patients and ANA in 3 (60%). No patient had hypocomplementemia, cryoglobulinemia, antimitochondrial or anti-LKM1 antibodies. Liver involvement was detected in two patients and consisted of slightly raised levels of transaminases. No patient showed clinical manifestations of liver disease such as hepatomegaly, splenomegaly, jaundice or clinical features of hepatic decompensation (ascites, encephalopathy or gastrointestinal bleeding). We found a prevalence of chronic HBV infection of 0.83% in SS, very similar to the prevalence in general population in Spain (0.7%). In contrast to the close association between SS and HCV, chronic HBV infection is not associated with SS in our geographical area, with a ratio SS-HBV/SS-HCV cases of 1:10.

MtZIP6 is a novel metal transporter required for symbiotic nitrogen fixation in nodules of Medicago truncatula plants

OpenAIRE

Saez Somolinos, Ángela; Imperial Ródenas, Juan; Gonzalez Guerrero, Manuel

2015-01-01

Symbiotic nitrogen fixation (SNF) carried out by the interaction rhizobia-legumes takes place in legume root nodules. Many of the enzymes involved in SNF are metalloproteins that obtain their metal cofactor from the host plant. Metals reach the nodule through the vasculature, where they are released in the apoplast on the infection/differentiation zone (zone II) of the nodule (Rodriguez-Haas et al., 2013). From there, these oligonutrients have to cross a number of membranes to be used for met...

Genes Required for Free Phage Production are Essential for Pseudomonas aeruginosa Chronic Lung Infections.

Science.gov (United States)

Lemieux, Andrée-Ann; Jeukens, Julie; Kukavica-Ibrulj, Irena; Fothergill, Joanne L; Boyle, Brian; Laroche, Jérôme; Tucker, Nicholas P; Winstanley, Craig; Levesque, Roger C

2016-02-01

The opportunistic pathogen Pseudomonas aeruginosa causes chronic lung infection in patients with cystic fibrosis. The Liverpool Epidemic Strain LESB58 is highly resistant to antibiotics, transmissible, and associated with increased morbidity and mortality. Its genome contains 6 prophages and 5 genomic islands. We constructed a polymerase chain reaction (PCR)-based signature-tagged mutagenesis library of 9216 LESB58 mutants and screened the mutants in a rat model of chronic lung infection. A total of 162 mutants were identified as defective for in vivo maintenance, with 11 signature-tagged mutagenesis mutants having insertions in prophage and genomic island genes. Many of these mutants showed both diminished virulence and reduced phage production. Transcription profiling by quantitative PCR and RNA-Seq suggested that disruption of these prophages had a widespread trans-acting effect on the transcriptome. This study demonstrates that temperate phages play a pivotal role in the establishment of infection through modulation of bacterial host gene expression. © The Author 2015. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Chronic Trichuris muris infection decreases diversity of the intestinal microbiota and concomitantly increases the abundance of lactobacilli

DEFF Research Database (Denmark)

Holm, Jacob Bak; Sorobetea, Daniel; Kiilerich, Pia

2015-01-01

The intestinal microbiota is vital for shaping the local intestinal environment as well as host immunity and metabolism. At the same time, epidemiological and experimental evidence suggest an important role for parasitic worm infections in maintaining the inflammatory and regulatory balance...... of the Lactobacillus genus. In parallel, chronic T. muris infection resulted in a significant shift in the balance between regulatory and inflammatory T cells in the intestinal adaptive immune system, in favour of inflammatory cells. Together, these data demonstrate that chronic parasite infection strongly influences...

A serum microRNA signature is associated with the immune control of chronic hepatitis B virus infection.

Directory of Open Access Journals (Sweden)

Maurizia Rossana Brunetto

Full Text Available BACKGROUND AND AIMS: The virus/host interplay mediates liver pathology in chronic HBV infection. MiRNAs play a pivotal role in virus/host interactions and are detected in both serum and HBsAg-particles, but studies of their dynamics during chronic infection and antiviral therapy are missing. We studied serum miRNAs during different phases of chronic HBV infection and antiviral treatment. METHODS: MiRNAs were profiled by miRCURY-LNA-Universal-RT-miRNA-PCR (Exiqon-A/S and qPCR-panels-I/II-739-miRNA-assays and single-RT-q-PCRs. Two cohorts of well-characterized HBsAg-carriers were studied (median follow-up 34-52 months: a training-panel (141 sera and HBsAg-particles (32 samples from 61 HBsAg-carriers and b validation-panel (136 sera from 84 carriers. RESULTS: Thirty-one miRNAs were differentially expressed in inactive-carriers (IC and chronic-hepatitis-B (CHB with the largest difference for miR-122-5p, miR-99a-5p and miR-192-5p (liver-specific-miRNAs, over-expressed in both sera and HBsAg-particles of CHB (ANOVA/U-test p-values: 8.3 Log10 IU/mL, ρ = -0.732, p<0.001 and HBsAg (3.40, 0.11/5.49 Log10 IU/mL, ρ = -0.883, p<0.001. At multivariate analysis HBV-DNA (p = 0.002, HBsAg (p<0.001 and infection-phase (p<0.001, but not ALT (p = 0.360 correlated with MiR-B-Index. In SVR to Peg-IFN/NUCs MiR-B-Index improved during-therapy and post-treatment reaching IC-like values (5.32, -1.65/10.91 vs 6.68, 0.54/9.53, p = 0.324 beckoning sustained HBV-immune-control earlier than HBsAg-decline. CONCLUSIONS: Serum miRNA profile change dynamically during the different phases of chronic HBV infection. We identified a miRNA signature associated with both natural-occurring and therapy-induced immune control of HBV infection. The MiR-B-Index might be a useful biomarker for the early identification of the sustained switch from CHB to inactive HBV-infection in patients treated with antivirals.

A single evolutionary innovation drives the deep evolution of symbiotic N2-fixation in angiosperms

Science.gov (United States)

Werner, Gijsbert D. A.; Cornwell, William K.; Sprent, Janet I.; Kattge, Jens; Kiers, E. Toby

2014-01-01

Symbiotic associations occur in every habitat on earth, but we know very little about their evolutionary histories. Current models of trait evolution cannot adequately reconstruct the deep history of symbiotic innovation, because they assume homogenous evolutionary processes across millions of years. Here we use a recently developed, heterogeneous and quantitative phylogenetic framework to study the origin of the symbiosis between angiosperms and nitrogen-fixing (N2) bacterial symbionts housed in nodules. We compile the largest database of global nodulating plant species and reconstruct the symbiosis’ evolution. We identify a single, cryptic evolutionary innovation driving symbiotic N2-fixation evolution, followed by multiple gains and losses of the symbiosis, and the subsequent emergence of ‘stable fixers’ (clades extremely unlikely to lose the symbiosis). Originating over 100 MYA, this innovation suggests deep homology in symbiotic N2-fixation. Identifying cryptic innovations on the tree of life is key to understanding the evolution of complex traits, including symbiotic partnerships. PMID:24912610

Symbiotic regulation of plant growth, development and reproduction

Science.gov (United States)

Rodriguez, R.J.; Freeman, D. Carl; McArthur, E.D.; Kim, Y.-O.; Redman, R.S.

2009-01-01

The growth and development of rice (Oryzae sativa) seedlings was shown to be regulated epigenetically by a fungal endophyte. In contrast to un-inoculated (nonsymbiotic) plants, endophyte colonized (symbiotic) plants preferentially allocated resources into root growth until root hairs were well established. During that time symbiotic roots expanded at five times the rate observed in nonsymbiotic plants. Endophytes also influenced sexual reproduction of mature big sagebrush (Artemisia tridentata) plants. Two spatially distinct big sagebrush subspecies and their hybrids were symbiotic with unique fungal endophytes, despite being separated by only 380 m distance and 60 m elevation. A double reciprocal transplant experiment of parental and hybrid plants, and soils across the hybrid zone showed that fungal endophytes interact with the soils and different plant genotypes to confer enhanced plant reproduction in soil native to the endophyte and reduced reproduction in soil alien to the endophyte. Moreover, the most prevalent endophyte of the hybrid zone reduced the fitness of both parental subspecies. Because these endophytes are passed to the next generation of plants on seed coats, this interaction provides a selective advantage, habitat specificity, and the means of restricting gene flow, thereby making the hybrid zone stable, narrow and potentially leading to speciation. ?? 2009 Landes Bioscience.

Energy distributions of symbiotic novae

International Nuclear Information System (INIS)

Bryan, G.L.; Kwok, S.

1991-01-01

The IRAS low-resolution spectra of three recent symbiotic novae are fitted with a dust continuum radiative transfer model. It is found that the dust shells are detached from the photosphere and that the sizes of the inner radii are correlated with times since outburst. An analysis of the IUE spectra of HM Sge at different epochs suggests that the strength of the 2200 A feature is decreasing with times and the grains responsible for the feature are probably formed in the white dwarf ejecta. A complete accounting of the entire energy budget from radio to X-ray shows that most of the energy is emitted by the cool component in the infrared, and a significant fraction of the flux of the hot component is escaping in the far-ultraviolet. The density-bounded nature of the circumstellar gas nebulae could be the result of a bipolar geometry of the nebulae. Unlike classical novae, the optical outburst of symbiotic novae is due to the ionization of the preexisting envelope of the cool component and is not the result of a sudden ejection by the hot component. 55 refs

Toxoplasma gondii Actively Inhibits Neuronal Function in Chronically Infected Mice

Science.gov (United States)

Haroon, Fahad; Händel, Ulrike; Angenstein, Frank; Goldschmidt, Jürgen; Kreutzmann, Peter; Lison, Holger; Fischer, Klaus-Dieter; Scheich, Henning; Wetzel, Wolfram; Schlüter, Dirk; Budinger, Eike

2012-01-01

Upon infection with the obligate intracellular parasite Toxoplasma gondii, fast replicating tachyzoites infect a broad spectrum of host cells including neurons. Under the pressure of the immune response, tachyzoites convert into slow-replicating bradyzoites, which persist as cysts in neurons. Currently, it is unclear whether T. gondii alters the functional activity of neurons, which may contribute to altered behaviour of T. gondii–infected mice and men. In the present study we demonstrate that upon oral infection with T. gondii cysts, chronically infected BALB/c mice lost over time their natural fear against cat urine which was paralleled by the persistence of the parasite in brain regions affecting behaviour and odor perception. Detailed immunohistochemistry showed that in infected neurons not only parasitic cysts but also the host cell cytoplasm and some axons stained positive for Toxoplasma antigen suggesting that parasitic proteins might directly interfere with neuronal function. In fact, in vitro live cell calcium (Ca2+) imaging studies revealed that tachyzoites actively manipulated Ca2+ signalling upon glutamate stimulation leading either to hyper- or hypo-responsive neurons. Experiments with the endoplasmatic reticulum Ca2+ uptake inhibitor thapsigargin indicate that tachyzoites deplete Ca2+ stores in the endoplasmatic reticulum. Furthermore in vivo studies revealed that the activity-dependent uptake of the potassium analogue thallium was reduced in cyst harbouring neurons indicating their functional impairment. The percentage of non-functional neurons increased over time In conclusion, both bradyzoites and tachyzoites functionally silence infected neurons, which may significantly contribute to the altered behaviour of the host. PMID:22530040

Toxoplasma gondii actively inhibits neuronal function in chronically infected mice.

Directory of Open Access Journals (Sweden)

Fahad Haroon

Full Text Available Upon infection with the obligate intracellular parasite Toxoplasma gondii, fast replicating tachyzoites infect a broad spectrum of host cells including neurons. Under the pressure of the immune response, tachyzoites convert into slow-replicating bradyzoites, which persist as cysts in neurons. Currently, it is unclear whether T. gondii alters the functional activity of neurons, which may contribute to altered behaviour of T. gondii-infected mice and men. In the present study we demonstrate that upon oral infection with T. gondii cysts, chronically infected BALB/c mice lost over time their natural fear against cat urine which was paralleled by the persistence of the parasite in brain regions affecting behaviour and odor perception. Detailed immunohistochemistry showed that in infected neurons not only parasitic cysts but also the host cell cytoplasm and some axons stained positive for Toxoplasma antigen suggesting that parasitic proteins might directly interfere with neuronal function. In fact, in vitro live cell calcium (Ca(2+ imaging studies revealed that tachyzoites actively manipulated Ca(2+ signalling upon glutamate stimulation leading either to hyper- or hypo-responsive neurons. Experiments with the endoplasmatic reticulum Ca(2+ uptake inhibitor thapsigargin indicate that tachyzoites deplete Ca(2+ stores in the endoplasmatic reticulum. Furthermore in vivo studies revealed that the activity-dependent uptake of the potassium analogue thallium was reduced in cyst harbouring neurons indicating their functional impairment. The percentage of non-functional neurons increased over time In conclusion, both bradyzoites and tachyzoites functionally silence infected neurons, which may significantly contribute to the altered behaviour of the host.

Sofosbuvir and Simeprevir Treatment of a Stem Cell Transplanted Teenager With Chronic Hepatitis C Infection.

Science.gov (United States)

Fischler, Björn; Priftakis, Peter; Sundin, Mikael

2016-06-01

There have been no previous reports on the use of interferon-free combinations in pediatric patients with chronic hepatitis C infection. An infected adolescent with severe sickle cell disease underwent stem cell transplantation and subsequent treatment with sofosbuvir and simeprevir during ongoing immunosuppression. Despite the emergence of peripheral edema as a side effect, treatment was continued with sustained antiviral response.

Impact of chronic infections (periodontic and endodontic in implant dentistry

Directory of Open Access Journals (Sweden)

Bhumanapalli Venkata Ramesh Reddy

2015-01-01

Full Text Available Dental implant plays an important role in oral rehabilitation. In recent decades, the concept of restoratively driven implant placement has become well-accepted. Thus, an increasing number of patients, especially those with past or present periodontitis or with periapical infections, desire to receive dental implants to restore their lost teeth. This review discusses the relationship between chronic periodontal and periapical infections with periimplantitis, with a focus on implant outcome. The studies considered for the inclusion were searched in MEDLINE (pubmed. The search was restricted to studies published in English from 1980 to 2015. Screening of eligible studies and data extraction were carried out by the reviewers. The articles included in the review comprised in vitro studies, in vivo studies (animals and humans, abstracts, and review articles.

Use of FDG-PET to detect a chronic odontogenic infection as a possible source of the brain abscess.

Science.gov (United States)

Sato, Jun; Kuroshima, Takeshi; Wada, Mayumi; Satoh, Akira; Watanabe, Shiro; Okamoto, Shozo; Shiga, Tohru; Tamaki, Nagara; Kitagawa, Yoshimasa

2016-05-01

This study describes the use of (18)F-fluoro-2-deoxyglucose positron emission tomography (FDG-PET) to detect a chronic odontogenic infection as the possible origin of a brain abscess (BA). A 74-year-old man with esophageal carcinoma was referred to our department to determine the origin of a BA in his oral cavity. He had no acute odontogenic infections. The BA was drained, and bacteria of the Staphylococcus milleri group were detected. Whole body FDG-PET revealed that the only sites of definite uptake of FDG were the esophageal carcinoma and the left upper maxillary region (SUVmax: 4.5). These findings suggested that the BA may have originated from a chronic periodontal infection. Six teeth with progressive chronic periodontal disease were extracted to remove the possible source of BA. These findings excluded the possibility of direct spread of bacteria from the odontogenic infectious lesion to the intracranial cavity. After extraction, there was no relapse of BA.

Salmonella Typhimurium undergoes distinct genetic adaption during chronic infections of mice

DEFF Research Database (Denmark)

Søndberg, Emilie; Jelsbak, Lotte

2016-01-01

Background Typhoid fever caused by Salmonella enterica serovar Typhi (S. Typhi) is a severe systemic human disease and endemic in regions of the world with poor drinking water quality and sewage treatment facilities. A significant number of patients become asymptomatic life-long carriers of S....... In the current study genetic adaptation during experimental chronic S. Typhimurium infections of mice, an established model of chronic typhoid fever, was probed as an approach for studying the molecular mechanisms of host-adaptation during long-term host-association. Results Individually sequence-tagged wild...

Resource utilization of symbiotic high-temperature gas-cooled reactor systems

International Nuclear Information System (INIS)

Borgonovi, G.M.; Brogli, R.H.

1978-01-01

The cumulative uranium requirements of different symbiotic combinations of high-temperature gas-cooled reactor (HTGR) prebreeders have been calculated assuming an open-end nuclear economy. The results obtained indicate that the combination of prebreeders and near-breeders does not save resources over a self-generated recycle case of comparable conversion ratio, and that it may take between 40 and 50 yr before the symbiotic system containing breeders starts saving resources over an HTGR with self-generated recycle and a conversion ratio of 0.83

A new carbon-symbiotic star in the Large Magellanic Cloud

International Nuclear Information System (INIS)

Cowley, A.P.; Hartwick, F.D.A.

1989-01-01

A new carbon-symbiotic star, designated as CH-95, was discovered during a study of the kinematics of CH stars in the LMC. The spectrum of CH-95 is presented. Some of the strong emission lines found include H, He I, He II, forbidden O III, and the broad C III/N III blend at 4640 A, often seen in compact systems such as X-ray binaries. A comparison was made with other C-star symbiotics in the LMC, SMC, and Draco. 12 refs

Terbinafine-loaded wound dressing for chronic superficial fungal infections

International Nuclear Information System (INIS)

Paskiabi, Farnoush Asghari; Bonakdar, Shahin; Shokrgozar, Mohammad Ali; Imani, Mohammad; Jahanshiri, Zahra; Shams-Ghahfarokhi, Masoomeh; Razzaghi-Abyaneh, Mehdi

2017-01-01

In spite of developing new drugs and modern formulations, the treatments of chronic fungal infections are still challenging. Fibrous wound dressings are new suggestions for the treatment of chronic superficial infections. In the present study, we formulated an antifungal agent, terbinafine hydrochloride (TFH), which is a hydrophobic drug, in wound dressings prepared by electrospun polycaprolactone, polycaprolactone/gelatin (50:50 w/w) and gelatin. To obtain more water-stable meshes, the preparations were treated by glutaraldehyde and their properties were determined before and after treatment. The morphology of fibrous meshes was observed by scanning electron microscopy. Drug loading efficiency and release rate were measured by high performance liquid chromatography (HPLC) and the release rate was monitored for 144 h. Antifungal tests were performed on Trichophyton mentagrophytes, Aspergillus fumigatus and Candida albicans cultured on Muller-Hinton agar. The toxicity of the meshes was measured after 24 h and 14 days by MTT assay. Terbinafine loading of polycaprolactone/gelatin (50:50) was 100% and it released the highest amount of TFH too. In antifungal tests, all samples were able to hinderT. mentagrophytes and A. fumigatus but not C. albicans growth among them, polycaprolactone fibers made the largest inhibition zone. In MTT assay, none of prepared samples showed toxicity against L929 cells. Teken together, the prepared TFH-loaded PCL/gelatin electrospun meshes were able to release TFH slowly and in a steady state in time. With respect to no obvious cytotoxicity in MTT assay and stong antifungal activity toward T. mentagrophytesin vitro, these TFH-based meshes could be considered as potential candidates in clinical application as wound dressing for treatment of chronic dermatophytosis. - Highlights: • Terbinafine (TFH)-loaded PCL/gelatin electrospun fibers were successfully fabricated. • TFH-loaded PCL/gelatin electrospun fibers showed a slow drug release

Terbinafine-loaded wound dressing for chronic superficial fungal infections

Energy Technology Data Exchange (ETDEWEB)

Paskiabi, Farnoush Asghari [Department of Mycology, Pasteur Institute of Iran, Tehran 13164. Iran (Iran, Islamic Republic of); Microbiology Research Center, Pasteur Institute of Iran, Tehran 13164. Iran (Iran, Islamic Republic of); Bonakdar, Shahin; Shokrgozar, Mohammad Ali [National Cell Bank Department, Pasteur Institute of Iran, Tehran 13164 (Iran, Islamic Republic of); Imani, Mohammad [Department of Novel Drug Delivery Systems, Iran Polymer and Petrochemical Institute, Tehran (Iran, Islamic Republic of); Jahanshiri, Zahra [Department of Mycology, Pasteur Institute of Iran, Tehran 13164. Iran (Iran, Islamic Republic of); Shams-Ghahfarokhi, Masoomeh [Department of Mycology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Razzaghi-Abyaneh, Mehdi, E-mail: mrab442@yahoo.com [Department of Mycology, Pasteur Institute of Iran, Tehran 13164. Iran (Iran, Islamic Republic of); Microbiology Research Center, Pasteur Institute of Iran, Tehran 13164. Iran (Iran, Islamic Republic of)

2017-04-01

In spite of developing new drugs and modern formulations, the treatments of chronic fungal infections are still challenging. Fibrous wound dressings are new suggestions for the treatment of chronic superficial infections. In the present study, we formulated an antifungal agent, terbinafine hydrochloride (TFH), which is a hydrophobic drug, in wound dressings prepared by electrospun polycaprolactone, polycaprolactone/gelatin (50:50 w/w) and gelatin. To obtain more water-stable meshes, the preparations were treated by glutaraldehyde and their properties were determined before and after treatment. The morphology of fibrous meshes was observed by scanning electron microscopy. Drug loading efficiency and release rate were measured by high performance liquid chromatography (HPLC) and the release rate was monitored for 144 h. Antifungal tests were performed on Trichophyton mentagrophytes, Aspergillus fumigatus and Candida albicans cultured on Muller-Hinton agar. The toxicity of the meshes was measured after 24 h and 14 days by MTT assay. Terbinafine loading of polycaprolactone/gelatin (50:50) was 100% and it released the highest amount of TFH too. In antifungal tests, all samples were able to hinderT. mentagrophytes and A. fumigatus but not C. albicans growth among them, polycaprolactone fibers made the largest inhibition zone. In MTT assay, none of prepared samples showed toxicity against L929 cells. Teken together, the prepared TFH-loaded PCL/gelatin electrospun meshes were able to release TFH slowly and in a steady state in time. With respect to no obvious cytotoxicity in MTT assay and stong antifungal activity toward T. mentagrophytesin vitro, these TFH-based meshes could be considered as potential candidates in clinical application as wound dressing for treatment of chronic dermatophytosis. - Highlights: • Terbinafine (TFH)-loaded PCL/gelatin electrospun fibers were successfully fabricated. • TFH-loaded PCL/gelatin electrospun fibers showed a slow drug release

On the late-type components of slow novae and symbiotic stars

International Nuclear Information System (INIS)

Allen, D.A.

1980-01-01

It is argued that the various types of symbiotic stars and the slow novae are the same phenomena exhibiting a range of associated time-scales, the slow novae being of intermediate speed. Evidence is summarized showing that both types of object contain normal M giants or mira variables. This fact is at odds with currently fashionable single-star models for slow novae, according to which the M star is totally disrupted before the outburst. Spectral types of the late-type components are presented for nearly 80 symbiotic stars and slow novae, derived from 2 μm spectroscopy. It is found that both the intensity of the emission spectrum and the electron density of the gas are functions of the spectral type of the late-type star. Explanations for these correlations are given. On the assumption that the late-type components are normal giants, spectroscopic parallaxes are determined; credible distances are derived which indicate that the known symbiotic stars have been sampled as far afield as the Galactic Centre. Hydrogen shell flashes on a white dwarf accreting gas from the late-type components offer an attractive explanation of the phenomena of slow novae and symbiotic stars, and such models are discussed in the concluding section. (author)

Prevention of Pneumococcal Infection in Children with Chronic Diseases of the Nasopharynx Reduces the Incidence of Other Respiratory Tract Infections: Results of a Comparative Prospective Study

Directory of Open Access Journals (Sweden)

V. P. Vavilova

2015-01-01

Full Text Available Background: A promising approach to solving the problem of widespread infections of the respiratory tract in children is the use ofspecific prophylaxis against the pneumococcus.Objective: Our aim was to examine the clinical efficacy of PCV13 of children with chronic foci of infection in the nasopharynx and the changes of local factors of protection of the upper respiratory tract.Methods: We have evaluated the incidence of respiratory tract and ENT infections in children with chronic diseases of the nasopharynx. Research period: January 2011 — January 2015. Upper airway function examination included cytologic analysis — counting the main cell populations ratio in the common cytoplasm, lysozym activity and secretory immunoglobulin of class A (sIgA in nasal secretions.Results: The study involved 876 children 2–5 years old. Main group (PCV13 amounted to 448 patients, and the control group (unvaccinated 428. Annual dynamic observation showed a significant reduction of acute morbidity by 2 times (p < 0.001, pneumonia by 2.4 times (p = 0.042, acute bronchitis by 2.5 times (p = 0.008, concomitant ENT pathology (acute otitis media and acute exacerbations of chronic sinusitis by 2.2 times (p = 0.001 and 2.3 times (p = 0.004, respectively. There was a positive effect of vaccination on the level of local factors of protection of the upper respiratory tract (lysozyme, sIgA, the somatic cell count in nasal secretions.Conclusion: PCV13 vaccination reduces the risk of developing acute respiratory infections and ENT infections in children with chronic diseases of the nasopharynx. This is against the background of recovery in the levels of factors of local immunity.

Symbiotic factors in Burkholderia essential for establishing an association with the bean bug, Riptortus pedestris.

Science.gov (United States)

Kim, Jiyeun Kate; Lee, Bok Luel

2015-01-01

Symbiotic bacteria are common in insects and intimately affect the various aspects of insect host biology. In a number of insect symbiosis models, it has been possible to elucidate the effects of the symbiont on host biology, whereas there is a limited understanding of the impact of the association on the bacterial symbiont, mainly due to the difficulty of cultivating insect symbionts in vitro. Furthermore, the molecular features that determine the establishment and persistence of the symbionts in their host (i.e., symbiotic factors) have remained elusive. However, the recently established model, the bean bug Riptortus pedestris, provides a good opportunity to study bacterial symbiotic factors at a molecular level through their cultivable symbionts. Bean bugs acquire genus Burkholderia cells from the environment and harbor them as gut symbionts in the specialized posterior midgut. The genome of the Burkholderia symbiont was sequenced, and the genomic information was used to generate genetically manipulated Burkholderia symbiont strains. Using mutant symbionts, we identified several novel symbiotic factors necessary for establishing a successful association with the host gut. In this review, these symbiotic factors are classified into three categories based on the colonization dynamics of the mutant symbiont strains: initiation, accommodation, and persistence factors. In addition, the molecular characteristics of the symbiotic factors are described. These newly identified symbiotic factors and on-going studies of the Riptortus-Burkholderia symbiosis are expected to contribute to the understanding of the molecular cross-talk between insects and bacterial symbionts that are of ecological and evolutionary importance. © 2014 Wiley Periodicals, Inc.

The Limitations of In Vitro Experimentation in Understanding Biofilms and Chronic Infection

DEFF Research Database (Denmark)

Roberts, Aled E. L.; Kragh, Kasper N.; Bjarnsholt, Thomas

2015-01-01

a systematic review of the most widely used in vitro biofilm systems, and we discuss why they are not always representative of the in vivo biofilms found in chronic infections. We present examples of methods that will help us to bridge the gap between in vitro and in vivo biofilm work so that we can ultimately......We have become increasingly aware that, during infection, pathogenic bacteria often grow in multicellular biofilms that are often highly resistant to antibacterial strategies. In order to understand how biofilms form and contribute to infection, many research groups around the world have heavily...

The Trust Project - Symbiotic Human Machine Teams: Social Cueing for Trust and Reliance

Science.gov (United States)

2016-06-30

AFRL-RH-WP-TR-2016-0096 THE TRUST PROJECT - SYMBIOTIC HUMAN-MACHINE TEAMS: SOCIAL CUEING FOR TRUST & RELIANCE Susan Rivers, Monika Lohani, Marissa...30 JUN 2012 – 30 JUN 2016 4. TITLE AND SUBTITLE THE TRUST PROJECT - SYMBIOTIC HUMAN-MACHINE TEAMS: SOCIAL CUEING FOR TRUST & RELIANCE 5a. CONTRACT

Regulatory NK cells mediated between immunosuppressive monocytes and dysfunctional T cells in chronic HBV infection.

Science.gov (United States)

Li, Haijun; Zhai, Naicui; Wang, Zhongfeng; Song, Hongxiao; Yang, Yang; Cui, An; Li, Tianyang; Wang, Guangyi; Niu, Junqi; Crispe, Ian Nicholas; Su, Lishan; Tu, Zhengkun

2017-09-12

HBV infection represents a major health problem worldwide, but the immunological mechanisms by which HBV causes chronic persistent infection remain only partly understood. Recently, cell subsets with suppressive features have been recognised among monocytes and natural killer (NK) cells. Here we examine the effects of HBV on monocytes and NK cells. Monocytes and NK cells derived from chronic HBV-infected patients and healthy controls were purified and characterised for phenotype, gene expression and cytokines secretion by flow cytometry, quantitative real-time (qRT)-PCR, ELISA and western blotting. Culture and coculture of monocytes and NK cells were used to determine NK cell activation, using intracellular cytokines staining. In chronic HBV infection, monocytes express higher levels of PD-L1, HLA-E, interleukin (IL)-10 and TGF-β, and NK cells express higher levels of PD-1, CD94 and IL-10, compared with healthy individuals. HBV employs hepatitis B surface antigen (HBsAg) to induce suppressive monocytes with HLA-E, PD-L1, IL-10 and TGF-β expression via the MyD88/NFκB signalling pathway. HBV-treated monocytes induce NK cells to produce IL-10, via PD-L1 and HLA-E signals. Such NK cells inhibit autologous T cell activation. Our findings reveal an immunosuppressive cascade, in which HBV generates suppressive monocytes, which initiate regulatory NK cells differentiation resulting in T cell inhibition. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Rotation of the Mass Donors in High-mass X-ray Binaries and Symbiotic Stars

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K. Stoyanov

2015-02-01

Full Text Available Our aim is to investigate the tidal interaction in High-mass X-ray Binaries and Symbiotic stars in order to determine in which objects the rotation of the mass donors is synchronized or pseudosynchronized with the orbital motion of the compact companion. We find that the Be/X-ray binaries are not synchronized and the orbital periods of the systems are greater than the rotational periods of the mass donors. The giant and supergiant High-mass X-ray binaries and symbiotic stars are close to synchronization. We compare the rotation of mass donors in symbiotics with the projected rotational velocities of field giants and find that the M giants in S-type symbiotics rotate on average 1.5 times faster than the field M giants. We find that the projected rotational velocity of the red giant in symbiotic star MWC 560 is v sin i= 8.2±1.5 km.s−1, and estimate its rotational period to be Prot<>/sub = 144 - 306 days. Using the theoretical predictions of tidal interaction and pseudosynchronization, we estimate the orbital eccentricity e = 0.68 − 0.82.

Challenges with current inhaled treatments for chronic Pseudomonas aeruginosa infection in patients with cystic fibrosis.

LENUS (Irish Health Repository)

Greally, Peter

2012-06-01

Pseudomonas aeruginosa (Pa) is the predominant pathogen infecting the airways of patients with cystic fibrosis (CF). Initial colonization is usually transient and associated with non-mucoid strains, which can be eradicated if identified early. This strategy can prevent, or at least delay, chronic Pa infection, which eventually develops in the majority of patients by their late teens or early adulthood. This article discusses the management and latest treatment developments of Pa lung infection in patients with CF, with a focus on nebulized antibiotic therapy.

Frequency of hepatitis B and C co-infection in chronic liver disease ...

African Journals Online (AJOL)

Hepatitis B (HBsAg) and C (HCV) virus are becoming a significant causative factors in the aetiology of chronic liver disease (CLD) worldwide. However, the information on the frequency of HBsAg and HCV virus co-infection in CLD is sparsely reported in Nigeria. In this study, we assessed the frequency of HBsAg and HCV ...

Chronic Tobacco-Smoking on Psychopathological Symptoms, Impulsivity and Cognitive Deficits in HIV-Infected Individuals.

Science.gov (United States)

Chang, Linda; Lim, Ahnate; Lau, Eric; Alicata, Daniel

2017-09-01

HIV-infected individuals (HIV+) has 2-3 times the rate of tobacco smoking than the general population, and whether smoking may lead to greater psychiatric symptoms or cognitive deficits remains unclear. We evaluated the independent and combined effects of being HIV+ and chronic tobacco-smoking on impulsivity, psychopathological symptoms and cognition. 104 participants [27 seronegative (SN)-non-Smokers, 26 SN-Smokers, 29 HIV+ non-Smokers, 22 HIV+ Smokers] were assessed for psychopathology symptoms (Symptom Checklist-90, SCL-90), depressive symptoms (Center for Epidemiologic Studies-Depression Scale, CES-D), impulsivity (Barratt Impulsiveness Scale, BIS), decision-making (The Iowa Gambling Task, IGT, and Wisconsin Card Sorting Test, WCST), and cognition (seven neurocognitive domains). Both HIV+ and Smoker groups had higher SCL-90 and CES-D scores, with highest scores in HIV+ Smokers. On BIS, both HIV+ and Smokers had higher Total Impulsiveness scores, with higher behavioral impulsivity in Smokers, highest in HIV+ Smokers. Furthermore, across the four groups, HIV+ Smokers lost most money and made fewest advantageous choices on the IGT, and had highest percent errors on WCST. Lastly, HIV+ had lower z-scores on all cognitive domains, with the lowest scores in HIV+ Smokers. These findings suggest that HIV-infection and chronic tobacco smoking may lead to additive deleterious effects on impulsivity, psychopathological (especially depressive) symptoms and cognitive dysfunction. Although greater impulsivity may be premorbid in HIV+ and Smokers, the lack of benefits of nicotine in chronic Smokers on attention and psychopathology, especially those with HIV-infection, may be due to the negative effects of chronic smoking on dopaminergic and cardio-neurovascular systems. Tobacco smoking may contribute to psychopathology and neurocognitive disorders in HIV+ individuals.

Interacting Winds in Eclipsing Symbiotic Systems - The Case Study of EG Andromedae

Science.gov (United States)

Calabrò, Emanuele

2014-03-01

We report the mathematical representation of the so called eccentric eclipse model, whose numerical solutions can be used to obtain the physical parameters of a quiescent eclipsing symbiotic system. Indeed the nebular region produced by the collision of the stellar winds should be shifted to the orbital axis because of the orbital motion of the system. This mechanism is not negligible, and it led us to modify the classical concept of an eclipse. The orbital elements obtained from spectroscopy and photometry of the symbiotic EG Andromedae were used to test the eccentric eclipse model. Consistent values for the unknown orbital elements of this symbiotic were obtained. The physical parameters are in agreement with those obtained by means of other simulations for this system.

Diffuse skin hyperpigmentation associated with chronic minocycline use in a patient with prosthetic joint infection

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Hadi Berbari

2017-01-01

Full Text Available Cutaneous hyperpigmentation is a recognized adverse effect of chronic minocycline use occurring in up to 50% of patients. In this report we present a rare case of extensive skin hyperpigmentation involving both lower extremities in a patient receiving long term minocycline. The patient was receiving minocycline as suppression for chronic prosthetic joint infection. Risk factors associated with minocycline-induced cutaneous pigmentation (MICH will be reviewed.

As a Rare Site of Invasive Fungal Infection, Chronic Granulomatous Aspergillus Synovitis: A Case Report

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Aylin Canbolat Ayhan

2013-06-01

Full Text Available Aspergillus can causes invasive disease of various organs especially in patients with weakened immune systems. Aspergillus synovitis and arthritis are uncommon types of involvement due to this infection. Approches to fungal osteoarticular infections are based on only case reports. This paper presents a rare case of chronic granulomatous Aspergillus synovitis in an immunocompromised 5-year old girl who was treated for acute lymphoblastic leukemia.

Immunolocalization and Changes of Hydroxyproline-Rich Glycoproteins During Symbiotic Germination of Dendrobium officinale.

Science.gov (United States)

Li, Yuan-Yuan; Chen, Xiao-Mei; Zhang, Ying; Cho, Yu-Hsiu; Wang, Ai-Rong; Yeung, Edward C; Zeng, Xu; Guo, Shun-Xing; Lee, Yung-I

2018-01-01

Hydroxyproline-rich glycoproteins (HRGPs) are abundant cell wall components involved in mycorrhizal symbiosis, but little is known about their function in orchid mycorrhizal association. To gain further insight into the role of HRGPs in orchid symbiosis, the location and function of HRGPs were investigated during symbiotic germination of Dendrobium officinale . The presence of JIM11 epitope in developing protocorms was determined using immunodot blots and immunohistochemical staining procedures. Real-time PCR was also employed to verify the expression patterns of genes coding for extensin-like genes selected from the transcriptomic database. The importance of HRGPs in symbiotic germination was further investigated using 3,4-dehydro-L-proline (3,4-DHP), an inhibitor of HRGP biosynthesis. In symbiotic cultures, immunodot blots of JIM11 signals were moderate in mature seeds, and the signals became stronger in swollen embryos. After germination, signal intensities decreased in developing protocorms. In contrast, in asymbiotic cultures, JIM11 signals were much lower as compared with those stages in symbiotic cultures. Immunofluorescence staining enabled the visualization of JIM11 epitope in mature embryo and protocorm cells. Positive signals were initially localized in the larger cells near the basal (suspensor) end of uninfected embryos, marking the future colonization site of fungal hyphae. After 1 week of inoculation, the basal end of embryos had been colonized, and a strong signal was detected mostly at the mid- and basal regions of the enlarging protocorm. As protocorm development progressed, the signal was concentrated in the colonized cells at the basal end. In colonized cells, signals were present in the walls and intracellularly associated with hyphae and the pelotons. The precise localization of JIM11 epitope is further examined by immunogold labeling. In the colonized cells, gold particles were found mainly in the cell wall and the interfacial matrix near the

Managing the fusion burn to improve symbiotic system performance

International Nuclear Information System (INIS)

Renier, J.P.; Martin, J.G.

1979-01-01

Symbiotic power systems, in which fissile fuel is produced in fusion-powered factories and burned in thermal reactors characterized by high conversion ratios, constitute an interesting near-term fusion application. It is shown that the economic feasibility of such systems depend on adroit management of the fusion burn. The economics of symbiotes is complex: reprocessing and fabrication of the fusion reactor blankets are important components of the production cost of fissile fuel, but burning fissile material in the breeder blanket raises overall costs and lowers the support ratio. Analyses of factories which assume that the fusion power is constant during an irradiation cycle underestimate their potential. To illustrate the effect of adroit engineering of the fusion burn, this paper analyzes systems based on D-T and semi-catalyzed D-D fusion-powered U-233 breeders. To make the D-T symbiote self-sufficient, tritium is bred in separate lithium blankets designed so as to minimize overall costs. All blankets are assumed to have spherical geometry, with 85% closure. Neutronics depletion calculations were performed with a revised version of the discrete ordinates code XSDRN-PM, using multigroup (100 neutron, 21 gamma-ray groups) coupled cross-section libraries

Mortality from respiratory infections and chronic obstructive pulmonary disease and associations with environmental quality.

Science.gov (United States)

Respiratory infections (RI) and chronic obstructive pulmonary disease (COPD) have been identified by the World Health Organization as conditions which may be strongly influenced by environmental factors. We examined the associations between environmental quality and U.S. county m...

T-bet-mediated Tim-3 expression dampens monocyte function during chronic hepatitis C virus infection.

Science.gov (United States)

Yi, Wenjing; Zhang, Peixin; Liang, Yan; Zhou, Yun; Shen, Huanjun; Fan, Chao; Moorman, Jonathan P; Yao, Zhi Q; Jia, Zhansheng; Zhang, Ying

2017-03-01

Hepatitis C virus (HCV) induces a high rate of chronic infection via dysregulation of host immunity. We have previously shown that T-cell immunoglobulin and mucin domain protein-3 (Tim-3) is up-regulated on monocyte/macrophages (M/Mφ) during chronic HCV infection; little is known, however, about the transcription factor that controls its expression in these cells. In this study, we investigated the role of transcription factor, T-box expressed in T cells (T-bet), in Tim-3 expression in M/Mφ in the setting of HCV infection. We demonstrate that T-bet is constitutively expressed in resting CD14 + M/Mφ in the peripheral blood. M/Mφ from chronically HCV-infected individuals exhibit a significant increase in T-bet expression that positively correlates with an increased level of Tim-3 expression. Up-regulation of T-bet is also observed in CD14 + M/Mφ incubated with HCV + Huh7.5 cells, as well as in primary M/Mφ or monocytic THP-1 cells exposed to HCV core protein in vitro, which is reversible by blocking HCV core/gC1qR interactions. Moreover, the HCV core-induced up-regulation of T-bet and Tim-3 expression in M/Mφ can be abrogated by incubating the cells with SP600125 - an inhibitor for the c-Jun N-terminal kinase (JNK) signalling pathway. Importantly, silencing T-bet gene expression decreases Tim-3 expression and enhances interleukin-12 secretion as well as signal transducer and activator of transcription 1 phosphorylation. These data suggest that T-bet, induced by the HCV core/gC1qR interaction, enhances Tim-3 expression via the JNK pathway, leading to dampened M/Mφ function during HCV infection. These findings reveal a novel mechanism for Tim-3 regulation via T-bet during HCV infection, providing new targets to combat this global epidemic viral disease. © 2016 John Wiley & Sons Ltd.

Arbidol: a broad-spectrum antiviral that inhibits acute and chronic HCV infection

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Pécheur Eve-Isabelle

2006-07-01

Full Text Available Abstract Arbidol (ARB is an antiviral compound that was originally proven effective for treatment of influenza and several other respiratory viral infections. The broad spectrum of ARB anti-viral activity led us to evaluate its effect on hepatitis C virus (HCV infection and replication in cell culture. Long-term ARB treatment of Huh7 cells chronically replicating a genomic length genotype 1b replicon resulted in sustained reduction of viral RNA and protein expression, and eventually cured HCV infected cells. Pre-treatment of human hepatoma Huh7.5.1 cells with 15 μM ARB for 24 to 48 hours inhibited acute infection with JFH-1 virus by up to 1000-fold. The inhibitory effect of ARB on HCV was not due to generalized cytotoxicity, nor to augmentation of IFN antiviral signaling pathways, but involved impaired virus-mediated membrane fusion. ARB's affinity for membranes may inhibit several aspects of the HCV lifecycle that are membrane-dependent.

Genetic and metabolic signals during acute enteric bacterial infection alter the microbiota and drive progression to chronic inflammatory disease

Energy Technology Data Exchange (ETDEWEB)

Kamdar, Karishma; Khakpour, Samira; Chen, Jingyu; Leone, Vanessa; Brulc, Jennifer; Mangatu, Thomas; Antonopoulos, Dionysios A.; Chang, Eugene B; Kahn, Stacy A.; Kirschner, Barbara S; Young, Glenn; DePaolo, R. William

2016-01-13

Chronic inflammatory disorders are thought to arise due to an interplay between predisposing host genetics and environmental factors. For example, the onset of inflammatory bowel disease is associated with enteric proteobacterial infection, yet the mechanistic basis for this association is unclear. We have shown previously that genetic defiency in TLR1 promotes acute enteric infection by the proteobacteria Yersinia enterocolitica. Examining that model further, we uncovered an altered cellular immune response that promotes the recruitment of neutrophils which in turn increases metabolism of the respiratory electron acceptor tetrathionate by Yersinia. These events drive permanent alterations in anti-commensal immunity, microbiota composition, and chronic inflammation, which persist long after Yersinia clearence. Deletion of the bacterial genes involved in tetrathionate respiration or treatment using targeted probiotics could prevent microbiota alterations and inflammation. Thus, acute infection can drive long term immune and microbiota alterations leading to chronic inflammatory disease in genetically predisposed individuals.

Impact of Chronic Hepatitis C Virus Genotype 1b Infection on Triglyceride Concentration in Serum Lipoprotein Fractions

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Tomohisa Nagano

2015-08-01

Full Text Available Reduced low-density lipoprotein (LDL cholesterol level is a characteristic feature of dyslipidemia in chronic hepatitis C virus (HCV infection. However, abnormality in serum triglyceride (TG has not been fully investigated. To clarify the impact of HCV genotype 1b (G1b infection and advanced fibrosis on serum TG profiles, TG concentrations in lipoprotein fractions were examined in fasting sera from 185 subjects with active or cleared HCV infection by high-performance liquid chromatography. Serum lipoproteins were fractionated into four classes: chylomicron, very low-density lipoprotein (VLDL, LDL, and high-density lipoprotein (HDL. Then, the significance of HCV G1b infection on TG levels in each lipoprotein fraction was determined using multiple regression models. We found that active HCV G1b infection was positively associated with high HDL-TG levels and low VLDL-TG levels, independent of other factors included in the regression model. In VLDL sub-fractions, active HCV infection was only found to be associated with low levels of large VLDL-TG. Similarly, advanced liver fibrosis in chronic HCV G1b infection was associated with high levels of LDL-TG, HDL-TG, and small VLDL-TG, independent of other clinical factors. These findings indicate that active HCV G1b infection and advanced fibrosis are closely associated with abnormal serum TG profiles.

St 2-22 - Another Symbiotic Star with High-Velocity Bipolar Jets

Science.gov (United States)

Tomov, T.; Zamanov, R.; Gałan, C.; Pietrukowicz, P.

2017-09-01

We report the detection of high-velocity components in the wings of Hα emission line in spectra of symbiotic binary star St 2-22 obtained in 2005. This finding encouraged us to start the present investigation in order to show that this poorly-studied object is a jet-producing system. We have used high-resolution optical and low-resolution near-infrared spectra, as well as available optical and infrared photometry, to evaluate some physical parameters of the St 2-22 components and characteristics of the jets. We confirm that St 2-22 is a S-type symbiotic star. Our results demonstrate that an unnoticed outburst, similar to those in classical symbiotic systems, occurred in the first half of 2005. During the outburst, collimated bipolar jets were ejected by the hot component of St 2-22 with an average velocity of about 1700 km/s.

Bullous pemphigoid associated with chronic hepatitis C virus infection in a hepatitis B virus endemic area: A case report.

Science.gov (United States)

Jang, Hyunil; Jin, Young-Joo; Yoon, Chang Hwi; Kim, Cheol-Woo; Kim, Lucia

2018-04-01

Bullous pemphigoid is a type of acute or chronic autoimmune disease that involves subepidermal skin lesions with bulla formation. Although viral infections, such as, human herpes virus (HHV), human immunodeficiency virus, cytomegalovirus, Epstein-Barr virus, HHV-6, hepatitis B virus (HBV), and hepatitis C virus (HCV), are known factors of bullous pemphigoid, HCV infection has only been rarely associated factor, especially in HBV endemic area. A 78-year-old man was admitted to our hospital due to erythematous bulla of onset 3 months before presentation affecting his entire body. Pathologic findings, that is, subepidermal bullae containing eosinophils and neutrophils with superficial perivascular lymphocytic and eosinophilic infiltration, were consistent with bullous pemphigoid. Anti-HCV was positive and HCV quantitative real-time polymerase chain reaction (PCR) was 1.25 x 10 IU/mL. HCV genotype was 2a. After a diagnosis of bullous pemphigoid associated with chronic HCV infection was reached, he was treated with oral methylprednisolone for bullous pemphigoid, and his skin lesions improved. Oral direct-acting antiviral agents (sofosbuvir plus ribavirin) were prescribed for chronic hepatitis C, and sustained viral response was achieved. The authors report a rare case of bullous pemphigoid associated with chronic HCV infection in a HBV endemic area and advise that HCV should be considered in the differential diagnosis of factors precipitating bullous pemphigoid, even in HBV endemic areas.

Telomere Dynamics in Immune Senescence and Exhaustion Triggered by Chronic Viral Infection

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Marcia Bellon

2017-10-01

Full Text Available The progressive loss of immunological memory during aging correlates with a reduced proliferative capacity and shortened telomeres of T cells. Growing evidence suggests that this phenotype is recapitulated during chronic viral infection. The antigenic volume imposed by persistent and latent viruses exposes the immune system to unique challenges that lead to host T-cell exhaustion, characterized by impaired T-cell functions. These dysfunctional memory T cells lack telomerase, the protein capable of extending and stabilizing chromosome ends, imposing constraints on telomere dynamics. A deleterious consequence of this excessive telomere shortening is the premature induction of replicative senescence of viral-specific CD8+ memory T cells. While senescent cells are unable to expand, they can survive for extended periods of time and are more resistant to apoptotic signals. This review takes a closer look at T-cell exhaustion in chronic viruses known to cause human disease: Epstein–Barr virus (EBV, Hepatitis B/C/D virus (HBV/HCV/HDV, human herpesvirus 8 (HHV-8, human immunodeficiency virus (HIV, human T-cell leukemia virus type I (HTLV-I, human papillomavirus (HPV, herpes simplex virus-1/2(HSV-1/2, and Varicella–Zoster virus (VZV. Current literature linking T-cell exhaustion with critical telomere lengths and immune senescence are discussed. The concept that enduring antigen stimulation leads to T-cell exhaustion that favors telomere attrition and a cell fate marked by enhanced T-cell senescence appears to be a common endpoint to chronic viral infections.

Impact of Helminth Infection on the Clinical and Microbiological Presentation of Chagas Diseases in Chronically Infected Patients.

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Fernando Salvador

2016-04-01

Full Text Available Helminth infections are highly prevalent in tropical and subtropical countries, coexisting in Chagas disease endemic areas. Helminth infections in humans may modulate the host immune system, changing the Th1/Th2 polarization. This immunological disturbance could modify the immune response to other infections. The aim of this study is to evaluate the relationship between clinical, microbiological and epidemiological characteristics of Chagas disease patients, with the presence of helminth infection.A prospective observational study was conducted at Vall d'Hebron University Hospital (Barcelona, Spain. Inclusion criteria were: age over 18 years, diagnosis of Chagas disease, and not having received specific treatment for Chagas disease previously to the inclusion. The study protocol included Chagas disease assessment (cardiac and digestive evaluation, detection of T. cruzi DNA measured by PCR in peripheral blood, and helminth infection diagnosis (detection of IgG anti-Strongyloides stercoralis by ELISA, microscopic examination of stool samples from three different days, and specific faecal culture for S. stercoralis larvae.Overall, 65 patients were included, median age was 38 years, 75.4% were women and most of them came from Bolivia. Cardiac and digestive involvement was present in 18.5% and 27.7% of patients respectively. T. cruzi PCR was positive in 28 (43.1% patients. Helminth infection was diagnosed in 12 (18.5% patients. No differences were observed in clinical and epidemiological characteristics between patients with and without helminth infection. Nevertheless, the proportion of patients with positive T. cruzi PCR was higher among patients with helminth infection compared with patients without helminth infection (75% vs 35.8%, p = 0.021.We observed a high prevalence of S. stercoralis infection among chronic Chagas disease patients attended in our tropical medicine unit. Strongyloidiasis was associated with significantly higher proportion of

INFECTIOUS VIRUS-ANTIBODY COMPLEX IN THE BLOOD OF CHRONICALLY INFECTED MICE

Science.gov (United States)

Notkins, Abner Louis; Mahar, Suellen; Scheele, Christina; Goffman, Joel

1966-01-01

If viremic sera from mice chronically infected with lactic dehydrogenase virus (LDV) were first treated with ether or ultraviolet light to inactivate the infectious virus, neutralizing antibody could be demonstrated. Significant amounts of antibody, however, were not detected until the mice had been infected for about 2½ months and its presence did not result in the elimination of the chronic viremia. Virus isolated from sera containing neutralizing antibody was found to be relatively resistant to neutralization by anti-LDV. Further studies revealed that the resistant virus existed in the form of an infectious virus-antibody complex (sensitized virus). The presence of such a complex was demonstrated by the fact that the virus fraction which persisted after in vivo or in vitro exposure to mouse anti-LDV was readily neutralized by goat anti-mouse sera or goat anti-mouse γ-globulin, whereas virus that had not been previously exposed to mouse anti-LDV was completely resistant to neutralization by goat anti-mouse sera. These findings suggest that (a) sensitization may play an important role in the resistance and susceptibility of a virus to neutralization by antiviral antibody, and (b) an anti-γ-globulin may prove useful in neutralizing the resistant fraction and in demonstrating otherwise undetectable antiviral antibody. PMID:5944351

Interleukin-1 gene polymorphisms in chronic gastritis patients infected with Helicobacter pylori as risk factors of gastric cancer development.

Science.gov (United States)

Hnatyszyn, Andrzej; Wielgus, Karolina; Kaczmarek-Rys, Marta; Skrzypczak-Zielinska, Marzena; Szalata, Marlena; Mikolajczyk-Stecyna, Joanna; Stanczyk, Jerzy; Dziuba, Ireneusz; Mikstacki, Adam; Slomski, Ryszard

2013-12-01

Epidemiological investigations indicated association of the Helicobacter pylori infections with the occurrence of inflammatory conditions of the gastric mucosa and development of chronic gastritis and intestinal type of gastric cancer. IL1A and IL1B genes have been proposed as key factors in determining risk of gastritis and malignant transformation. The aim of this paper was to evaluate association of interleukin-1 gene polymorphisms with chronic gastritis, atrophy, intestinal metaplasia, dysplasia and intestinal type of gastric cancer in H. pylori-infected patients. Patients subjected to analysis represent group of 144 consecutive cases that suffered from dyspepsia with coexisting infection of H. pylori and chronic gastritis, chronic atrophic gastritis, intestinal metaplasia, dysplasia or gastric cancer. Molecular studies involved analysis of -889C>T polymorphism of IL1A gene and +3954C>T polymorphism of IL1B gene. Statistical analysis of association of polymorphism -889C>T of gene IL1A with changes in gastric mucosa showed lack of significance, whereas +3954C>T polymorphism of IL1B gene showed significant association. Frequency of allele T of +3954C>T polymorphism of IL1B gene was higher in group of patients with chronic gastritis, atrophy, intestinal metaplasia, dysplasia or intestinal type of gastric cancer (32.1 %) as compared with population group (23 %), χ(2) = 4.61 and p = 0.03. This corresponds to odds ratio: 1.58, 95 % CI: 1.04-2.4. Our results indicate that +3954C>T polymorphism of IL1B gene increase susceptibility to inflammatory response of gastric mucosa H. pylori-infected patients and plays a significant role in the development of chronic gastritis, atrophy, intestinal metaplasia, dysplasia and the initiation of carcinogenesis.

Symbiots: Conceptual Interventions Into Urban Energy Systems

DEFF Research Database (Denmark)

Bergström, Jenny; Mazé, Ramia; Redströmand, Johan

2009-01-01

Symbiots set out to examine values such as ease-of-use, comfort, and rationality assumed within conventions of ‘good design’, in order to expose issues related to energy consumption and current human- (versus eco-) centered design paradigms. Exploring re-interpretations of graphical patterns, arc...

The immune response to chronic Pseudomonas aeruginosa lung infection in cystic fibrosis patients is predominantly of the Th2 type

DEFF Research Database (Denmark)

Moser, C; Kjaergaard, S; Pressler, T

2000-01-01

Most cystic fibrosis (CF) patients with chronic Pseudomonas aeruginosa lung infection have a persistent acute type lung inflammation dominated by polymorphonuclear neutrophils (PMN) and a pronounced antibody response against P. aeruginosa. We speculated whether this immune response in CF...... is of the Th2 type and whether a change to a Th1 type immune response could improve the prognosis. Therefore, we studied 14 CF patients with (CF +P) and 14 CF patients without (CF -P) chronic P. aeruginosa lung infection. The specific production of interferon-gamma (IFN-gamma) and interleukin-4 (IL-4......: Rho=0.524; ptype immune response is most frequent in CF patients with chronic P. aeruginosa lung infection, and the patients with a Th1-dominated immune response had the best lung function. The clinical implication is that a change to a Th1 type immune response might...

Clinical Predictors of Liver Fibrosis in Patients With Chronic Hepatitis B Virus Infection From Children to Adults.

Science.gov (United States)

Wu, Jia-Feng; Song, Shih-Hsi; Lee, Chee-Seng; Chen, Huey-Ling; Ni, Yen-Hsuan; Hsu, Hong-Yuan; Wu, Tzee-Chung; Chang, Mei-Hwei

2018-04-11

This study aimed to elucidate predictors of liver fibrosis in patients with chronic hepatitis B virus (HBV) infection. Transient elastography was performed to define liver stiffness in 533 patients with chronic HBV infection (mean age ± standard deviation, 30.72 ± 0.57 years). Protein array was performed on serum samples and lysates of Huh7 cells transfected with HBV mutants; the results were confirmed by enzyme-linked immunosorbent assay. Single-nucleotide polymorphisms in the gene encoding interleukin 1β (IL-1β) were examined in patients with chronic HBV infection with and without liver fibrosis. Male sex, age ≥18 years, and serum α-fetoprotein level >3.6 ng/mL were independent predictors of a liver stiffness measurement of ≥7 kPa (P = .005, .019, and rs16944 and the CC genotype at rs1143627 in the gene encoding IL-1β were associated with higher serum IL-1β levels and liver fibrosis. Male sex, age ≥18 years, elevated α-fetoprotein level, and HBeAg-negative hepatitis are risk factors for liver fibrosis. IL-1β is involved in the progression of liver fibrosis in subjects with HBeAg-negative hepatitis.

The Biomarker GlycA Is Associated with Chronic Inflammation and Predicts Long-Term Risk of Severe Infection.

Science.gov (United States)

Ritchie, Scott C; Würtz, Peter; Nath, Artika P; Abraham, Gad; Havulinna, Aki S; Fearnley, Liam G; Sarin, Antti-Pekka; Kangas, Antti J; Soininen, Pasi; Aalto, Kristiina; Seppälä, Ilkka; Raitoharju, Emma; Salmi, Marko; Maksimow, Mikael; Männistö, Satu; Kähönen, Mika; Juonala, Markus; Ripatti, Samuli; Lehtimäki, Terho; Jalkanen, Sirpa; Perola, Markus; Raitakari, Olli; Salomaa, Veikko; Ala-Korpela, Mika; Kettunen, Johannes; Inouye, Michael

2015-10-28

The biomarker glycoprotein acetylation (GlycA) has been shown to predict risk of cardiovascular disease and all-cause mortality. Here, we characterize biological processes associated with GlycA by leveraging population-based omics data and health records from >10,000 individuals. Our analyses show that GlycA levels are chronic within individuals for up to a decade. In apparently healthy individuals, elevated GlycA corresponded to elevation of myriad inflammatory cytokines, as well as a gene coexpression network indicative of increased neutrophil activity, suggesting that individuals with high GlycA may be in a state of chronic inflammatory response. Accordingly, analysis of infection-related hospitalization and death records showed that increased GlycA increased long-term risk of severe non-localized and respiratory infections, particularly septicaemia and pneumonia. In total, our work demonstrates that GlycA is a biomarker for chronic inflammation, neutrophil activity, and risk of future severe infection. It also illustrates the utility of leveraging multi-layered omics data and health records to elucidate the molecular and cellular processes associated with biomarkers. Copyright © 2015 Elsevier Inc. All rights reserved.

Nitrous oxide production in sputum from cystic fibrosis patients with chronic Pseudomonas aeruginosa lung infection.

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Mette Kolpen

Full Text Available Chronic lung infection by Pseudomonas aeruginosa is the major severe complication in cystic fibrosis (CF patients, where P. aeruginosa persists and grows in biofilms in the endobronchial mucus under hypoxic conditions. Numerous polymorphonuclear leukocytes (PMNs surround the biofilms and create local anoxia by consuming the majority of O2 for production of reactive oxygen species (ROS. We hypothesized that P. aeruginosa acquires energy for growth in anaerobic endobronchial mucus by denitrification, which can be demonstrated by production of nitrous oxide (N2O, an intermediate in the denitrification pathway. We measured N2O and O2 with electrochemical microsensors in 8 freshly expectorated sputum samples from 7 CF patients with chronic P. aeruginosa infection. The concentrations of NO3(- and NO2(- in sputum were estimated by the Griess reagent. We found a maximum median concentration of 41.8 µM N2O (range 1.4-157.9 µM N2O. The concentration of N2O in the sputum was higher below the oxygenated layers. In 4 samples the N2O concentration increased during the initial 6 h of measurements before decreasing for approximately 6 h. Concomitantly, the concentration of NO3(- decreased in sputum during 24 hours of incubation. We demonstrate for the first time production of N2O in clinical material from infected human airways indicating pathogenic metabolism based on denitrification. Therefore, P. aeruginosa may acquire energy for growth by denitrification in anoxic endobronchial mucus in CF patients. Such ability for anaerobic growth may be a hitherto ignored key aspect of chronic P. aeruginosa infections that can inform new strategies for treatment and prevention.

Nitrous oxide production in sputum from cystic fibrosis patients with chronic Pseudomonas aeruginosa lung infection.

Science.gov (United States)

Kolpen, Mette; Kühl, Michael; Bjarnsholt, Thomas; Moser, Claus; Hansen, Christine Rønne; Liengaard, Lars; Kharazmi, Arsalan; Pressler, Tanja; Høiby, Niels; Jensen, Peter Østrup

2014-01-01

Chronic lung infection by Pseudomonas aeruginosa is the major severe complication in cystic fibrosis (CF) patients, where P. aeruginosa persists and grows in biofilms in the endobronchial mucus under hypoxic conditions. Numerous polymorphonuclear leukocytes (PMNs) surround the biofilms and create local anoxia by consuming the majority of O2 for production of reactive oxygen species (ROS). We hypothesized that P. aeruginosa acquires energy for growth in anaerobic endobronchial mucus by denitrification, which can be demonstrated by production of nitrous oxide (N2O), an intermediate in the denitrification pathway. We measured N2O and O2 with electrochemical microsensors in 8 freshly expectorated sputum samples from 7 CF patients with chronic P. aeruginosa infection. The concentrations of NO3(-) and NO2(-) in sputum were estimated by the Griess reagent. We found a maximum median concentration of 41.8 µM N2O (range 1.4-157.9 µM N2O). The concentration of N2O in the sputum was higher below the oxygenated layers. In 4 samples the N2O concentration increased during the initial 6 h of measurements before decreasing for approximately 6 h. Concomitantly, the concentration of NO3(-) decreased in sputum during 24 hours of incubation. We demonstrate for the first time production of N2O in clinical material from infected human airways indicating pathogenic metabolism based on denitrification. Therefore, P. aeruginosa may acquire energy for growth by denitrification in anoxic endobronchial mucus in CF patients. Such ability for anaerobic growth may be a hitherto ignored key aspect of chronic P. aeruginosa infections that can inform new strategies for treatment and prevention.

Impaired Subset Progression and Polyfunctionality of T Cells in Mice Exposed to Methamphetamine during Chronic LCMV Infection.

Science.gov (United States)

Sriram, Uma; Hill, Beth L; Cenna, Jonathan M; Gofman, Larisa; Fernandes, Nicole C; Haldar, Bijayesh; Potula, Raghava

2016-01-01

Methamphetamine (METH) is a widely used psychostimulant that severely impacts the host's innate and adaptive immune systems and has profound immunological implications. T cells play a critical role in orchestrating immune responses. We have shown recently how chronic exposure to METH affects T cell activation using a murine model of lymphocytic choriomeningitis virus (LCMV) infection. Using the TriCOM (trinary state combinations) feature of GemStone™ to study the polyfunctionality of T cells, we have analyzed how METH affected the cytokine production pattern over the course of chronic LCMV infection. Furthermore, we have studied in detail the effects of METH on splenic T cell functions, such as cytokine production and degranulation, and how they regulate each other. We used the Probability State Modeling (PSM) program to visualize the differentiation of effector/memory T cell subsets during LCMV infection and analyze the effects of METH on T cell subset progression. We recently demonstrated that METH increased PD-1 expression on T cells during viral infection. In this study, we further analyzed the impact of PD-1 expression on T cell functional markers as well as its expression in the effector/memory subsets. Overall, our study indicates that analyzing polyfunctionality of T cells can provide additional insight into T cell effector functions. Analysis of T cell heterogeneity is important to highlight changes in the evolution of memory/effector functions during chronic viral infections. Our study also highlights the impact of METH on PD-1 expression and its consequences on T cell responses.

Adipose Tissue Is a Neglected Viral Reservoir and an Inflammatory Site during Chronic HIV and SIV Infection.

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Abderaouf Damouche

2015-09-01

Full Text Available Two of the crucial aspects of human immunodeficiency virus (HIV infection are (i viral persistence in reservoirs (precluding viral eradication and (ii chronic inflammation (directly associated with all-cause morbidities in antiretroviral therapy (ART-controlled HIV-infected patients. The objective of the present study was to assess the potential involvement of adipose tissue in these two aspects. Adipose tissue is composed of adipocytes and the stromal vascular fraction (SVF; the latter comprises immune cells such as CD4+ T cells and macrophages (both of which are important target cells for HIV. The inflammatory potential of adipose tissue has been extensively described in the context of obesity. During HIV infection, the inflammatory profile of adipose tissue has been revealed by the occurrence of lipodystrophies (primarily related to ART. Data on the impact of HIV on the SVF (especially in individuals not receiving ART are scarce. We first analyzed the impact of simian immunodeficiency virus (SIV infection on abdominal subcutaneous and visceral adipose tissues in SIVmac251 infected macaques and found that both adipocytes and adipose tissue immune cells were affected. The adipocyte density was elevated, and adipose tissue immune cells presented enhanced immune activation and/or inflammatory profiles. We detected cell-associated SIV DNA and RNA in the SVF and in sorted CD4+ T cells and macrophages from adipose tissue. We demonstrated that SVF cells (including CD4+ T cells are infected in ART-controlled HIV-infected patients. Importantly, the production of HIV RNA was detected by in situ hybridization, and after the in vitro reactivation of sorted CD4+ T cells from adipose tissue. We thus identified adipose tissue as a crucial cofactor in both viral persistence and chronic immune activation/inflammation during HIV infection. These observations open up new therapeutic strategies for limiting the size of the viral reservoir and decreasing low

Original article The Symbiotic Bond Questionnaire – theoretical background and psychometric qualities

OpenAIRE

Aleksandra Lewandowska-Walter; Magdalena Błażek; Maria Kaźmierczak

2015-01-01

Background The article describes the Symbiotic Bond Questionnaire (SBQ) – the theoretical background as well as its psychometric characteristics and psychological correlates. The items were created on the basis of the definition of symbiotic personality (Johnson, 1994a). Participants and procedure For these initial survey development and cross-validation studies, the factor structure and psychometric properties of the SBQ were examined. To assess the SBQ’s reliability, the...

Survey Explores Symbiotic Relationship between China’s Nonofficial Finance and SMEs

Institute of Scientific and Technical Information of China (English)

虞群娥; 李爱喜

2008-01-01

Domestic and foreign studies have revealed the existence of an interactive development relationship between nono cial nance and small and medium-sizedenterprises.Based on the empirical findings of a Hangzhou case study,this article substantiates the existence of a very strong symbiotic relationship between China’s nono cial nance and small and medium-sized enterprises(SMEs).This symbiotic relationship is an equilibrium outcome among three market players:formalnance,nono cial nance and SMEs.Meanwhile,it is also a rational choice and suboptimal equilibrium point reached under the existing institutional spaceconstraints.In our empirical study,we found that formal nance failure left a space for symbiosis to survive in two ways:the comparative advantages of nono cialnance created an institutional basis for symbiosis to grow,and immense SME fund shortages created a market space for symbiosis to thrive.In this article,we alsoput forward some recommendations for further development of such a symbiotic relationship.

The microorganisms in chronically infected end-stage and non-end-stage cystic fibrosis patients

DEFF Research Database (Denmark)

Rudkjøbing, Vibeke B; Thomsen, Trine R; Alhede, Morten

2011-01-01

Patients suffering from cystic fibrosis (CF) develop chronic lung infections because of highly viscous mucus, where bacteria can form biofilms. In this study, we investigated the microorganisms present in the lungs of end-stage and non-end-stage patients using standard culturing techniques and mo...

77 FR 30293 - Recommendations for the Identification of Hepatitis C Virus (HCV) Chronic Infection

Science.gov (United States)

2012-05-22

...: Division of Viral Hepatitis, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Centers... Morgan, Division of Viral Hepatitis, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB...-2012-0005] Recommendations for the Identification of Hepatitis C Virus (HCV) Chronic Infection AGENCY...

Rhizobial peptidase HrrP cleaves host-encoded signaling peptides and mediates symbiotic compatibility.

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Price, Paul A; Tanner, Houston R; Dillon, Brett A; Shabab, Mohammed; Walker, Graham C; Griffitts, Joel S

2015-12-08

Legume-rhizobium pairs are often observed that produce symbiotic root nodules but fail to fix nitrogen. Using the Sinorhizobium meliloti and Medicago truncatula symbiotic system, we previously described several naturally occurring accessory plasmids capable of disrupting the late stages of nodule development while enhancing bacterial proliferation within the nodule. We report here that host range restriction peptidase (hrrP), a gene found on one of these plasmids, is capable of conferring both these properties. hrrP encodes an M16A family metallopeptidase whose catalytic activity is required for these symbiotic effects. The ability of hrrP to suppress nitrogen fixation is conditioned upon the genotypes of both the host plant and the hrrP-expressing rhizobial strain, suggesting its involvement in symbiotic communication. Purified HrrP protein is capable of degrading a range of nodule-specific cysteine-rich (NCR) peptides encoded by M. truncatula. NCR peptides are crucial signals used by M. truncatula for inducing and maintaining rhizobial differentiation within nodules, as demonstrated in the accompanying article [Horváth B, et al. (2015) Proc Natl Acad Sci USA, 10.1073/pnas.1500777112]. The expression pattern of hrrP and its effects on rhizobial morphology are consistent with the NCR peptide cleavage model. This work points to a symbiotic dialogue involving a complex ensemble of host-derived signaling peptides and bacterial modifier enzymes capable of adjusting signal strength, sometimes with exploitative outcomes.

Minocycline attenuates HIV-1 infection and suppresses chronic immune activation in humanized NOD/LtsZ-scidIL-2Rγnull mice

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Singh, Maneesh; Singh, Pratibha; Vaira, Dolores; Amand, Mathieu; Rahmouni, Souad; Moutschen, Michel

2014-01-01

More than a quarter of a century of research has established chronic immune activation and dysfunctional T cells as central features of chronic HIV infection and subsequent immunodeficiency. Consequently, the search for a new immunomodulatory therapy that could reduce immune activation and improve T-cell function has been increased. However, the lack of small animal models for in vivo HIV study has hampered progress. In the current study, we have investigated a model of cord blood haematopoietic progenitor cells (CB-HPCs) -transplanted humanized NOD/LtsZ-scidIL-2Rγnull mice in which progression of HIV infection is associated with widespread chronic immune activation and inflammation. Indeed, HIV infection in humanized NSG mice caused up-regulation of several T-cell immune activation markers such as CD38, HLA-DR, CD69 and co-receptor CCR5. T-cell exhaustion markers PD-1 and CTLA-4 were found to be significantly up-regulated on T cells. Moreover, increased plasmatic levels of lipopolysaccharide, sCD14 and interleukin-10 were also observed in infected mice. Treatment with minocycline resulted in a significant decrease of expression of cellular and plasma immune activation markers, inhibition of HIV replication and improved T-cell counts in HIV-infected humanized NSG mice. The study demonstrates that minocycline could be an effective, low-cost adjunctive treatment to regulate chronic immune activation and replication of HIV. PMID:24409837

Chronic wasting disease prion infection of differentiated neurospheres.

Science.gov (United States)

Iwamaru, Yoshifumi; Mathiason, Candace K; Telling, Glenn C; Hoover, Edward A

2017-07-04

A possible strategy to develop more diverse cell culture systems permissive to infection with naturally occurring prions is to exploit culture of neurospheres from transgenic mice expressing the normal prion protein (PrP) of the native host species. Accordingly, we developed differentiated neurosphere cultures from the cervid PrP-expressing mice to investigate whether this in vitro system would support replication of non-adapted cervid-origin chronic wasting disease (CWD) prions. Here we report the successful amplification of disease-associated PrP in differentiated neurosphere cultures within 3 weeks after exposure to CWD prions from both white-tailed deer or elk. This neurosphere culture system provides a new in vitro tool that can be used to assess non-adapted CWD prion propagation and transmission.

Impaired platelet aggregation and rebalanced hemostasis in patients with chronic hepatitis C virus infection

DEFF Research Database (Denmark)

Nielsen, Nick S.; Jespersen, Sofie; Gaardbo, Julie C.

2017-01-01

Increased risk of both cardiovascular disease (CVD) and bleeding has been found in patients with chronic hepatitis C (CHC) infection, and a re-balanced hemostasis has been proposed. The aim of this study was to investigate functional whole blood coagulation and platelet function in CHC infection....... The prospective study included 82 patients with CHC infection (39 with advanced liver fibrosis and 43 with no or mild liver fibrosis) and 39 healthy controls. A total of 33 patients were treated for CHC infection and achieved sustained virological response (SVR). Baseline and post-treatment blood samples were...... collected. Hemostasis was assessed by both standard coagulation tests and functional whole blood hemostatic assays (thromboelastograhy (TEG), and platelet aggregation (Multiplate). Patients with CHC and advanced fibrosis had impaired platelet aggregation both compared to patients with no or mild fibrosis...

Pre-announcement of symbiotic guests: transcriptional reprogramming by mycorrhizal lipochitooligosaccharides shows a strict co-dependency on the GRAS transcription factors NSP1 and RAM1.

Science.gov (United States)

Hohnjec, Natalija; Czaja-Hasse, Lisa F; Hogekamp, Claudia; Küster, Helge

2015-11-23

infecting hyphae; linking responses to externally applied LCOs with early root colonization. Since both RAM1 and NSP1 were essential for the pre-symbiotic transcriptional reprogramming by Myc-LCOs, we propose that downstream of the CSSP, these GRAS transcription factors act synergistically in the transduction of those diffusible signals that pre-announce the presence of symbiotic fungi.

Postnatal Infections and Immunology Affecting Chronic Lung Disease of Prematurity.

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Pryhuber, Gloria S

2015-12-01

Premature infants suffer significant respiratory morbidity during infancy with long-term negative consequences on health, quality of life, and health care costs. Enhanced susceptibility to a variety of infections and inflammation play a large role in early and prolonged lung disease following premature birth, although the mechanisms of susceptibility and immune dysregulation are active areas of research. This article reviews aspects of host-pathogen interactions and immune responses that are altered by preterm birth and that impact chronic respiratory morbidity in these children. Copyright © 2015 Elsevier Inc. All rights reserved.

Infrared spectroscopy of symbiotic stars and the nature of their cool components

International Nuclear Information System (INIS)

Kenyon, S.J.; Gallagher, J.S.

1983-01-01

We present low-resolution 2--4 μm spectroscopy of a small sample of symbiotic stars, in an effort to determine if the giant components of these systems fill their Roche Lobes. A [2.35]-[2.2] color index measures the strength of the CO absorption band and provides a useful discriminant of luminosity class among single M-type giants which separates normal giants from supergiants at the same spectral type. Although interpretation of symbiotic spectra is complicated somewhat by their binary nature, our results suggest the late-type components in these systems range from normal red giants to bright asymptotic giants. The possible presence of non-Roche Lobe filling, low-luminosity giants in some symbiotic stars cannot be understood within the framework of existing theories for these interesting objects, and thus may provide important information for understanding mass transfer in binary systems

Mixed infections may promote diversification of mutualistic symbionts: why are there ineffective rhizobia?

Science.gov (United States)

Friesen, M L; Mathias, A

2010-02-01

While strategy variation is a key feature of symbiotic mutualisms, little work focuses on the origin of this diversity. Rhizobia strategies range from mutualistic nitrogen fixers to parasitic nonfixers that hoard plant resources to increase their own survival in soil. Host plants reward beneficial rhizobia with higher nodule growth rates, generating a trade-off between reproduction in nodules and subsequent survival in soil. However, hosts might not discriminate between strains in mixed infections, allowing nonfixing strains to escape sanctions. We construct an adaptive dynamics model of symbiotic nitrogen-fixation and find general situations where symbionts undergo adaptive diversification, but in most situations complete nonfixers do not evolve. Social conflict in mixed infections when symbionts face a survival-reproduction trade-off can drive the origin of some coexisting symbiont strategies, where less mutualistic strains exploit benefits generated by better mutualists.

Combination ledipasvir-sofosbuvir for the treatment of chronic hepatitis C virus infection: a review and clinical perspective

Directory of Open Access Journals (Sweden)

Nkuize M

2016-06-01

Full Text Available Marcel Nkuize,1 Thomas Sersté,1,2 Michel Buset,1 Jean-Pierre Mulkay11Department of Gastroenterology and Hepatology, Saint-Pierre University Hospital, 2Department of Gastroenterology, Pancreatology and Hepatology, Hôpital Academique Erasme, Université Libre de Bruxelles, Brussels, Belgium Abstract: Chronic hepatitis C treatment has continued to evolve, and interferon-free, oral treatment with direct-acting antiviral agents is the current standard of care. Recently, a new treatment, which is a combination of two direct-acting antiviral agents, ledipasvir 90 mg (anti-NS5A and sofosbuvir 400 mg (anti-NS5B, has been approved in the US and the European Union for the treatment of chronic hepatitis C viral infection. In Phase III trials among chronic hepatitis C virus genotype 1 monoinfected (treatment-naïve, treatment-experienced, and with advanced liver disease or posttransplant patients and HIV–hepatitis C virus coinfected patients, the ledipasvir-sofosbuvir fixed-dose combination is associated with a higher rate of sustained virologic response at 12 weeks after therapy has ceased. According to preliminary data, the ledipasvir-sofosbuvir combination also may be effective against hepatitis C genotype 4 virus infection. The ledipasvir-sofosbuvir combination taken orally is generally well-tolerated. Moreover, the combination treatment may suppress the effect of predictive factors of chronic hepatitis C that have historically been known to be associated with treatment failure. Thus, the fixed-dose single-tablet combination of ledipasvir-sofosbuvir offers a new era for the effective treatment of a variety of patients suffering from chronic hepatitis C virus infection.Keywords: ledipasvir, liver disease, ethnicity, DAA, HIV

First Resolved Images of the Mira AB Symbiotic Binary at Centimeter Wavelengths

OpenAIRE

Matthews, Lynn D.; Karovska, Margarita

2005-01-01

We report the first spatially resolved radio continuum measurements of the Mira AB symbiotic binary system, based on observations obtained with the Very Large Array (VLA). This is the first time that a symbiotic binary has been resolved unambiguously at centimeter wavelengths. We describe the results of VLA monitoring of both stars over a ten month period, together with constraints on their individual spectral energy distributions, variability, and radio emission mechanisms. The emission from...

Prevalence and risk factors of hepatitis D virus infection in patients with chronic hepatitis B infection attending the three main tertiary hospitals in Libya.

Science.gov (United States)

Elzouki, Abdel-Naser; Bashir, Saleh M; Elahmer, Omar; Elzouki, Islam; Alkhattali, Fathi

2017-12-01

Globally, More than 350 million individuals are chronically infected with hepatitis B virus (HBV), and >20 million of them are co-infected with hepatitis D virus (HDV). The aim of this study was to determine the pattern of HDV infection in patients with chronic hepatitis B in three main tertiary hospitals in Tripoli and Benghazi, Libya. This cross sectional and descriptive study was conducted on 162 patients with chronic hepatitis B positive for more than six months) who were followed up at hepatitis clinics of the three main tertiary hospitals in Tripoli city (88 patients from Tripoli Medical Centre and Tripoli Central Hospital) and Benghazi city (74 patients from Aljomhoria Hospital) during the period from January 2010 to June 2012. HBV and HDV markers were detected by enzyme linked fluorescent assay (ELFA) or enzyme-linked immunosorbent assay and HBV-DNA was quantified by real-time PCR techniques. The mean age of patients was 36,92 ± 15,35. One hundred and three (63.6%) of them were males and 59 (36,4%) were females. Four patients (2,5%) were tested positive for anti-HD antibodies, all of them have had clinical and/or histological diagnosis of cirrhosis. In multivariable regression analysis, age (p = .04), elevation of serum ALT (p = .03), elevation of serum AST (p = .04), and presence of cirrhosis (p = .003) were significantly related to HDV seropositivity. Although the study demonstrated that Libya has low to moderate prevalence of HDV (2,5%), it is important for policy makers and health care providers to continue the preventive measures for HDV spread, and HBV prevention program including utilization of HBV vaccine. Furthermore, it is imperative to screen chronic HBV patients for HDV for close observation for early diagnosis of subsequent development of liver cirrhosis. Moreover, further epidemiologic and genetic studies are needed to explore the trend for HDV infection in Libya. Copyright © 2017 Pan-Arab Association of Gastroenterology

Wound-Healing Peptides for Treatment of Chronic Diabetic Foot Ulcers and Other Infected Skin Injuries

Directory of Open Access Journals (Sweden)

Ana Gomes

2017-10-01

Full Text Available As the incidence of diabetes continues to increase in the western world, the prevalence of chronic wounds related to this condition continues to be a major focus of wound care research. Additionally, over 50% of chronic wounds exhibit signs and symptoms that are consistent with localized bacterial biofilms underlying severe infections that contribute to tissue destruction, delayed wound-healing and other serious complications. Most current biomedical approaches for advanced wound care aim at providing antimicrobial protection to the open wound together with a matrix scaffold (often collagen-based to boost reestablishment of the skin tissue. Therefore, the present review is focused on the efforts that have been made over the past years to find peptides possessing wound-healing properties, towards the development of new and effective wound care treatments for diabetic foot ulcers and other skin and soft tissue infections.

Wound-Healing Peptides for Treatment of Chronic Diabetic Foot Ulcers and Other Infected Skin Injuries.

Science.gov (United States)

Gomes, Ana; Teixeira, Cátia; Ferraz, Ricardo; Prudêncio, Cristina; Gomes, Paula

2017-10-18

As the incidence of diabetes continues to increase in the western world, the prevalence of chronic wounds related to this condition continues to be a major focus of wound care research. Additionally, over 50% of chronic wounds exhibit signs and symptoms that are consistent with localized bacterial biofilms underlying severe infections that contribute to tissue destruction, delayed wound-healing and other serious complications. Most current biomedical approaches for advanced wound care aim at providing antimicrobial protection to the open wound together with a matrix scaffold (often collagen-based) to boost reestablishment of the skin tissue. Therefore, the present review is focused on the efforts that have been made over the past years to find peptides possessing wound-healing properties, towards the development of new and effective wound care treatments for diabetic foot ulcers and other skin and soft tissue infections.

Soluble CD163 predicts incident chronic lung, kidney and liver disease in HIV infection