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Sample records for contrasting infection strategies

  1. Contrasting life strategies of viruses that infect photo- and heterotrophic bacteria, as revealed by viral tagging.

    PubMed

    Deng, Li; Gregory, Ann; Yilmaz, Suzan; Poulos, Bonnie T; Hugenholtz, Philip; Sullivan, Matthew B

    2012-10-30

    Ocean viruses are ubiquitous and abundant and play important roles in global biogeochemical cycles by means of their mortality, horizontal gene transfer, and manipulation of host metabolism. However, the obstacles involved in linking viruses to their hosts in a high-throughput manner bottlenecks our ability to understand virus-host interactions in complex communities. We have developed a method called viral tagging (VT), which combines mixtures of host cells and fluorescent viruses with flow cytometry. We investigated multiple viruses which infect each of two model marine bacteria that represent the slow-growing, photoautotrophic genus Synechococcus (Cyanobacteria) and the fast-growing, heterotrophic genus Pseudoalteromonas (Gammaproteobacteria). Overall, viral tagging results for viral infection were consistent with plaque and liquid infection assays for cyanobacterial myo-, podo- and siphoviruses and some (myo- and podoviruses) but not all (four siphoviruses) heterotrophic bacterial viruses. Virus-tagged Pseudoalteromonas organisms were proportional to the added viruses under varied infection conditions (virus-bacterium ratios), while no more than 50% of the Synechococcus organisms were virus tagged even at viral abundances that exceeded (5 to 10×) that of their hosts. Further, we found that host growth phase minimally impacts the fraction of virus-tagged Synechococcus organisms while greatly affecting phage adsorption to Pseudoalteromonas. Together these findings suggest that at least two contrasting viral life strategies exist in the oceans and that they likely reflect adaptation to their host microbes. Looking forward to the point at which the virus-tagging signature is well understood (e.g., for Synechococcus), application to natural communities should begin to provide population genomic data at the proper scale for predictively modeling two of the most abundant biological entities on Earth. Viral study suffers from an inability to link viruses to hosts en

  2. Contrasting Infection Strategies in Generalist and Specialist Wasp Parasitoids of Drosophila melanogaster

    PubMed Central

    Schlenke, Todd A; Morales, Jorge; Govind, Shubha; Clark, Andrew G

    2007-01-01

    Although host–parasitoid interactions are becoming well characterized at the organismal and cellular levels, much remains to be understood of the molecular bases for the host immune response and the parasitoids' ability to defeat this immune response. Leptopilina boulardi and L. heterotoma, two closely related, highly infectious natural parasitoids of Drosophila melanogaster, appear to use very different infection strategies at the cellular level. Here, we further characterize cellular level differences in the infection characteristics of these two wasp species using newly derived, virulent inbred strains, and then use whole genome microarrays to compare the transcriptional response of Drosophila to each. While flies attacked by the melanogaster group specialist L. boulardi (strain Lb17) up-regulate numerous genes encoding proteolytic enzymes, components of the Toll and JAK/STAT pathways, and the melanization cascade as part of a combined cellular and humoral innate immune response, flies attacked by the generalist L. heterotoma (strain Lh14) do not appear to initiate an immune transcriptional response at the time points post-infection we assayed, perhaps due to the rapid venom-mediated lysis of host hemocytes (blood cells). Thus, the specialist parasitoid appears to invoke a full-blown immune response in the host, but suppresses and/or evades downstream components of this response. Given that activation of the host immune response likely depletes the energetic resources of the host, the specialist's infection strategy seems relatively disadvantageous. However, we uncover the mechanism for one potentially important fitness tradeoff of the generalist's highly immune suppressive infection strategy. PMID:17967061

  3. The Value of Contrast: Contrasting the Value of Strategies.

    ERIC Educational Resources Information Center

    Garcia, Erica C.; Putte, F. C. M. V.

    1988-01-01

    Analyzes the differences in usage of the Spanish preterite and imperfect by native speakers of Spanish and by nonnative speakers of Spanish whose first language is Dutch. Teaching strategies to enhance the learner's awareness of context and sequencing are suggested. (LMO)

  4. Photochemotherapeutic strategy against Acanthamoeba infections.

    PubMed

    Aqeel, Yousuf; Siddiqui, Ruqaiyyah; Anwar, Ayaz; Shah, Muhammad Raza; Khoja, Shahrukh; Khan, Naveed Ahmed

    2015-01-01

    Acanthamoeba is a protist pathogen that can cause serious human infections, including blinding keratitis and a granulomatous amoebic encephalitis that almost always results in death. The current treatment for these infections includes a mixture of drugs, and even then, a recurrence can occur. Photochemotherapy has shown promise in the treatment of Acanthamoeba infections; however, the selective targeting of pathogenic Acanthamoeba has remained a major concern. The mannose-binding protein is an important adhesin expressed on the surface membranes of pathogenic Acanthamoeba organisms. To specifically target Acanthamoeba, the overall aim of this study was to synthesize a photosensitizing compound (porphyrin) conjugated with mannose and test its efficacy in vitro. The synthesis of mannose-conjugated porphyrin was achieved by mixing benzaldehyde and pyrrole, yielding tetraphenylporphyrin. Tetraphenylporphyrin was then converted into mono-nitrophenylporphyrin by selectively nitrating the para position of the phenyl rings, as confirmed by nuclear magnetic resonance (NMR) spectroscopy. The mono-nitrophenylporphyrin was reduced to mono-aminophenylporphyrin in the presence of tin dichloride and confirmed by a peak at m/z 629. Finally, mono-aminoporphyrin was conjugated with mannose, resulting in the formation of an imine bond. Mannose-conjugated porphyrin was confirmed through spectroscopic analysis and showed that it absorbed light of wavelengths ranging from 425 to 475 nm. To determine the antiacanthamoebic effects of the derived product, amoebae were incubated with mannose-conjugated porphyrin for 1 h and washed 3 times to remove extracellular compound. Next, the amoebae were exposed to light of the appropriate wavelength for 1 h. The results revealed that mannose-conjugated porphyrin produced potent trophicidal effects and blocked excystation. In contrast, Acanthamoeba castellanii incubated with mannose alone and porphyrin alone did not exhibit an antiamoebic effect

  5. Photochemotherapeutic Strategy against Acanthamoeba Infections

    PubMed Central

    Aqeel, Yousuf; Siddiqui, Ruqaiyyah; Anwar, Ayaz; Shah, Muhammad Raza; Khoja, Shahrukh

    2015-01-01

    Acanthamoeba is a protist pathogen that can cause serious human infections, including blinding keratitis and a granulomatous amoebic encephalitis that almost always results in death. The current treatment for these infections includes a mixture of drugs, and even then, a recurrence can occur. Photochemotherapy has shown promise in the treatment of Acanthamoeba infections; however, the selective targeting of pathogenic Acanthamoeba has remained a major concern. The mannose-binding protein is an important adhesin expressed on the surface membranes of pathogenic Acanthamoeba organisms. To specifically target Acanthamoeba, the overall aim of this study was to synthesize a photosensitizing compound (porphyrin) conjugated with mannose and test its efficacy in vitro. The synthesis of mannose-conjugated porphyrin was achieved by mixing benzaldehyde and pyrrole, yielding tetraphenylporphyrin. Tetraphenylporphyrin was then converted into mono-nitrophenylporphyrin by selectively nitrating the para position of the phenyl rings, as confirmed by nuclear magnetic resonance (NMR) spectroscopy. The mono-nitrophenylporphyrin was reduced to mono-aminophenylporphyrin in the presence of tin dichloride and confirmed by a peak at m/z 629. Finally, mono-aminoporphyrin was conjugated with mannose, resulting in the formation of an imine bond. Mannose-conjugated porphyrin was confirmed through spectroscopic analysis and showed that it absorbed light of wavelengths ranging from 425 to 475 nm. To determine the antiacanthamoebic effects of the derived product, amoebae were incubated with mannose-conjugated porphyrin for 1 h and washed 3 times to remove extracellular compound. Next, the amoebae were exposed to light of the appropriate wavelength for 1 h. The results revealed that mannose-conjugated porphyrin produced potent trophicidal effects and blocked excystation. In contrast, Acanthamoeba castellanii incubated with mannose alone and porphyrin alone did not exhibit an antiamoebic effect

  6. Contrast enhanced exposure strategy in multi-beam mask writing

    NASA Astrophysics Data System (ADS)

    Belic, Nikola; Hofmann, Ulrich; Klikovits, Jan; Martens, Stephan

    2013-03-01

    Since multi electron beam exposure has become a serious contender for next generation mask making, proximity- and process effect corrections (PEC) need to be adapted to this technology. With feature sizes in the order of the short-range blurs (resist and tool), contrast enhancements need to be combined with standard linearity corrections. Different PEC strategies are reviewed and compared with respect to their suitability for multi-beam exposure. This analysis recommends a hybrid approach that combines the benefits of shape- and dose PEC and is optimally applicable for multibeam exposure. Exposure results on the proof-of-concept 50keV electron multi-beam mask exposure tool (eMET POC) and a standard 50 kV vector shaped beam tool (VSB) are shown to verify that the combined PEC with overdose contrast enhancement covers the whole pattern range from isolated to opaque.

  7. Mosquito defense strategies against viral infection

    PubMed Central

    Cheng, Gong; Liu, Yang; Wang, Penghua; Xiao, Xiaoping

    2015-01-01

    Mosquito-borne viral diseases are a major concern of global health and result in significant economic losses in many countries. As natural vectors, mosquitoes are very permissive to and allow systemic and persistent arbovirus infection. Intriguingly, persistent viral propagation in mosquito tissues neither results in dramatic pathological sequelae nor impairs the vectorial behavior or lifespan, indicating that mosquitoes have evolved mechanisms to tolerate persistent infection and developed efficient antiviral strategies to restrict viral replication to non-pathogenic levels. Here, we provide an overview of recent progress in understanding mosquito antiviral immunity and advances in the strategies by which mosquitoes control viral infection in specific tissues. PMID:26626596

  8. Novel strategies to fight Candida species infection.

    PubMed

    Rodrigues, Maria Elisa; Silva, Sónia; Azeredo, Joana; Henriques, Mariana

    2016-08-01

    In recent years, there has been a significant increase in the incidence of human fungal infections. The increase in cases of infection caused by Candida species, and the consequent excessive use of antimicrobials, has favored the emergence of resistance to conventional antifungal agents over the past decades. Consequently, Candida infections morbidity and mortality are also increasing. Therefore, new approaches are needed to improve the outcome of patients suffering from Candida infections, because it seems unlikely that the established standard treatments will drastically lower the morbidity of mucocutaneous Candida infections and the high mortality associated with invasive candidiasis. This review aims to present the last advances in the traditional antifungal therapy, and present an overview of novel strategies that are being explored for the treatment of Candida infections, with a special focus on combined antifungal agents, antifungal therapies with alternative compounds (plant extracts and essential oils), adjuvant immunotherapy, photodynamic therapy and laser therapy.

  9. Two unlike cousins: Candida albicans and C. glabrata infection strategies

    PubMed Central

    Brunke, Sascha; Hube, Bernhard

    2013-01-01

    Candida albicans and C. glabrata are the two most common pathogenic yeasts of humans, yet they are phylogenetically, genetically and phenotypically very different. In this review, we compare and contrast the strategies of C. albicans and C. glabrata to attach to and invade into the host, obtain nutrients and evade the host immune response. Although their strategies share some basic concepts, they differ greatly in their outcome. While C. albicans follows an aggressive strategy to subvert the host response and to obtain nutrients for its survival, C. glabrata seems to have evolved a strategy which is based on stealth, evasion and persistence, without causing severe damage in murine models. However, both fungi are successful as commensals and as pathogens of humans. Understanding these strategies will help in finding novel ways to fight Candida, and fungal infections in general. PMID:23253282

  10. Immunization strategies for Clostridium difficile infections.

    PubMed

    Rebeaud, Fabien; Bachmann, Martin F

    2012-04-01

    Clostridium difficile infection is a major cause of nosocomial disease in Western countries. The recent emergence of hypervirulent strains resistant to most antibiotics correlates with increasing disease incidence, severity and lethal outcomes. Current treatments rely on metronidazol and vancomycin, but the limited ability of these antibiotics to cure infection and prevent relapse highlights the need for new strategies. A better knowledge of the molecular mechanisms of the disease, the host immune response and identification of key virulence factors of Clostridium difficile now permits the development of new products specifically targeting the pathogen. Immune-based strategies relying on active vaccination or passive administration of antibody products are the focus of intense research and, today, the efficacy of monoclonal antibodies and of two vaccines are evaluated clinically. This review presents recent data, discusses the different strategies and highlights the challenges linked to the development of immunization strategies against this emerging threat.

  11. Periprosthetic Knee Infection: Ten Strategies That Work

    PubMed Central

    Cavanaugh, Priscilla Ku; Diaz-Ledezma, Claudio

    2013-01-01

    Periprosthetic joint infection (PJI) is one of the most serious complications following total knee arthroplasty (TKA). The demand for TKA is rapidly increasing, resulting in a subsequent increase in infections involving knee prosthesis. Despite the existence of common management practices, the best approach for several aspects in the management of periprosthetic knee infection remains controversial. This review examines the current understanding in the management of the following aspects of PJI: preoperative risk stratification, preoperative antibiotics, preoperative skin preparation, outpatient diagnosis, assessing for infection in revision cases, improving culture utility, irrigation and debridement, one and two-stage revision, and patient prognostic information. Moreover, ten strategies for the management of periprosthetic knee infection based on available literature, and experience of the authors were reviewed. PMID:24368992

  12. Contrasting drought-response strategies in California redwoods.

    PubMed

    Ambrose, Anthony R; Baxter, Wendy L; Wong, Christopher S; Næsborg, Rikke R; Williams, Cameron B; Dawson, Todd E

    2015-05-01

    We compared the physiology and growth of seedlings originating from different Sequoia sempervirens (D. Don.) Endl. (coast redwood) and Sequoiadendron giganteum (Lindl.) Buchh. (giant sequoia) populations subjected to progressive drought followed by a recovery period in a controlled greenhouse experiment. Our objective was to examine how multiple plant traits interact to influence the response of seedlings of each species and seed population to a single drought and recovery cycle. We measured soil and plant water status, leaf gas exchange, stem embolism and growth of control (well-watered) and drought-stressed (water withheld) seedlings from each population at the beginning, middle and end of a 6-week drought period and again 2 weeks after re-watering. The drought had a significant effect on many aspects of seedling performance, but water-stressed seedlings regained most physiological functioning by the end of the recovery period. Sequoiadendron seedlings exhibited a greater degree of isohydry (water status regulation), lower levels of stem embolism, higher biomass allocation to roots and lower sensitivity of growth to drought compared with Sequoia. Only minor intra-specific differences were observed among populations. Our results show that seedlings of the two redwood species exhibit contrasting drought-response strategies that align with the environmental conditions these trees experience in their native habitats, and demonstrate trade-offs and coordination among traits affecting plant water use, carbon gain and growth under drought.

  13. Immunotherapeutic strategies to combat staphylococcal infections.

    PubMed

    Ohlsen, Knut; Lorenz, Udo

    2010-08-01

    Antibiotic-resistant staphylococci are the leading cause of nosocomial infections in many hospitals around the world. Meanwhile, methicillin-resistant Staphylococcus aureus (MRSA) spread also in the community where highly virulent strains infect healthy adults that have no predisposing risk factors. Although a few novel antibiotics have been recently introduced into clinical practice, the search for alternative strategies to efficiently combat staphylococcal infections is urgently demanded to decrease the enormous burden caused by pathogenic staphylococci. In particular, immunological strategies based on vaccine development or therapeutic antibodies may significantly enhance the efficiency of anti-staphylococcal therapy. Most approaches are directed against surface components of staphylococci such as cell wall-linked adhesins, teichoic acids, capsule, the biofilm component PIA/PNAG, or soluble virulence determinants such as alpha-toxin, Panton-Valentine leukocidin, or superantigenic enterotoxins. Although 2 recent clinical trials have failed, several novel promising vaccines and therapeutic antibodies are currently in preclinical and clinical development.

  14. Establishment of Chronic Infection: Brucella's Stealth Strategy

    PubMed Central

    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

  15. Establishment of Chronic Infection: Brucella's Stealth Strategy.

    PubMed

    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.

  16. Combinatorial strategies for combating invasive fungal infections.

    PubMed

    Spitzer, Michaela; Robbins, Nicole; Wright, Gerard D

    2017-02-17

    Invasive fungal infections are an important cause of human mortality and morbidity, particularly for immunocompromised populations. However, there remains a paucity of antifungal drug treatments available to combat these fungal pathogens. Further, antifungal compounds are plagued with problems such as host toxicity, fungistatic activity, and the emergence of drug resistance in pathogen populations. A promising therapeutic strategy to increase drug effectiveness and mitigate the emergence of drug resistance is through the use of combination drug therapy. In this review we describe the current arsenal of antifungals in medicine and elaborate on the benefits of combination therapy to expand our current antifungal drug repertoire. We examine those antifungal combinations that have shown potential against fungal pathogens and discuss strategies being employed to discover novel combination therapeutics, in particular combining antifungal agents with non-antifungal bioactive compounds. The findings summarized in this review highlight the promise of combinatorial strategies in combatting invasive mycoses.

  17. Metabolic profiles of sunflower genotypes with contrasting response to Sclerotinia sclerotiorum infection.

    PubMed

    Peluffo, Lucila; Lia, Verónica; Troglia, Carolina; Maringolo, Carla; Norma, Paniego; Escande, Alberto; Esteban Hopp, H; Lytovchenko, Anna; Fernie, Alisdair R; Heinz, Ruth; Carrari, Fernando

    2010-01-01

    We report a comprehensive primary metabolite profiling of sunflower (Helianthus annuus) genotypes displaying contrasting behavior to Sclerotinia sclerotiorum infection. Applying a GC-MS-based metabolite profiling approach, we were able to identify differential patterns involving a total of 63 metabolites including major and minor sugars and sugar alcohols, organic acids, amino acids, fatty acids and few soluble secondary metabolites in the sunflower capitulum, the main target organ of pathogen attack. Metabolic changes and disease incidence of the two contrasting genotypes were determined throughout the main infection period (R5.2-R6). Both point-by-point and non-parametric statistical analyses showed metabolic differences between genotypes as well as interaction effects between genotype and time after inoculation. Network correlation analyses suggested that these metabolic changes were synchronized in a time-dependent manner in response to the pathogen. Concerted differential metabolic changes were detected to a higher extent in the susceptible, rather than the resistant genotype, thereby allowing differentiation of modules composed by intermediates of the same pathway which are highly interconnected in the susceptible line but not in the resistant one. Evaluation of these data also demonstrated a genotype specific regulation of distinct metabolic pathways, suggesting the importance of detection of metabolic patterns rather than specific metabolite changes when looking for metabolic markers differentially responding to pathogen infection. In summary, the GC-MS strategy developed in this study was suitable for detection of differences in carbon primary metabolism in sunflower capitulum, a tissue which is the main entry point for this and other pathogens which cause great detrimental impact on crop yield.

  18. Contrasting Strategies of Tree Function in a Seasonal Amazon Rainforest

    NASA Astrophysics Data System (ADS)

    Ivanov, V. Y.; Oliveira, R.; Agee, E.; Brum, M., Jr.; Saleska, S. R.; Fatichi, S.; Ewing, G.

    2015-12-01

    The increased frequency and severity of drought conditions in the Amazon Basin region have emphasized the question of rainforest vulnerability and resilience to heat and drought-induced stresses. However, what emerges from much research is that the impacts of droughts, essential controlling factors of the rainforest function, and variability of tree-scale strategies are yet to be fully understood. We present here a preliminary analysis of hydraulic relations of a seasonal Amazon rainforest using a set of ecohydrologic data collected through the GoAmazon project over dry and wet seasons. Expressions of different hydraulic strategies are identified that convey different implications for tree resilience during short- (diurnal) and longer-term (seasonal) stress periods. These hydraulic strategies appear to be inter-related with the tree growth and non-structural carbohydrate dynamics, contributing to the understanding of trait coordination at the whole-plant scale. Integration of individual responses is conducted over a range of wood density and exposure conditions. The results of this research thus shed light on the implication of variations in the rainforest function for future stresses, vital for predictive models of ecosystem dynamics of next generation.

  19. Contrasting movement strategies among juvenile albatrosses and petrels.

    PubMed

    de Grissac, Sophie; Börger, Luca; Guitteaud, Audrey; Weimerskirch, Henri

    2016-05-18

    Animal movement is a fundamental eco-evolutionary process yet the behaviour of juvenile animals is largely unknown for many species, especially for soaring seabirds which can range widely over the oceans at low cost. We present an unprecedented dataset of 98 juvenile albatrosses and petrels (nine species), tracked for the first three months after independence. There was a startling diversity within and among species in the type and scale of post-natal movement strategies, ranging from area-restricted to nomadic patterns. Spatial scales were clustered in three groups that ranged from <3000 km to >6000 km from the natal nest. In seven of the nine species, the orientation of flight paths and other movement statistics showed strong similarities between juveniles and adults, providing evidence for innate orientation abilities. Our results have implications for understanding the development of foraging behaviour in naïve individuals and the evolution of life history traits such as survival, lifespan and breeding strategy.

  20. Contrasting movement strategies among juvenile albatrosses and petrels

    NASA Astrophysics Data System (ADS)

    de Grissac, Sophie; Börger, Luca; Guitteaud, Audrey; Weimerskirch, Henri

    2016-05-01

    Animal movement is a fundamental eco-evolutionary process yet the behaviour of juvenile animals is largely unknown for many species, especially for soaring seabirds which can range widely over the oceans at low cost. We present an unprecedented dataset of 98 juvenile albatrosses and petrels (nine species), tracked for the first three months after independence. There was a startling diversity within and among species in the type and scale of post-natal movement strategies, ranging from area-restricted to nomadic patterns. Spatial scales were clustered in three groups that ranged from <3000 km to >6000 km from the natal nest. In seven of the nine species, the orientation of flight paths and other movement statistics showed strong similarities between juveniles and adults, providing evidence for innate orientation abilities. Our results have implications for understanding the development of foraging behaviour in naïve individuals and the evolution of life history traits such as survival, lifespan and breeding strategy.

  1. Contrasting movement strategies among juvenile albatrosses and petrels

    PubMed Central

    de Grissac, Sophie; Börger, Luca; Guitteaud, Audrey; Weimerskirch, Henri

    2016-01-01

    Animal movement is a fundamental eco-evolutionary process yet the behaviour of juvenile animals is largely unknown for many species, especially for soaring seabirds which can range widely over the oceans at low cost. We present an unprecedented dataset of 98 juvenile albatrosses and petrels (nine species), tracked for the first three months after independence. There was a startling diversity within and among species in the type and scale of post-natal movement strategies, ranging from area-restricted to nomadic patterns. Spatial scales were clustered in three groups that ranged from <3000 km to >6000 km from the natal nest. In seven of the nine species, the orientation of flight paths and other movement statistics showed strong similarities between juveniles and adults, providing evidence for innate orientation abilities. Our results have implications for understanding the development of foraging behaviour in naïve individuals and the evolution of life history traits such as survival, lifespan and breeding strategy. PMID:27189182

  2. Adaptation strategies to climate change and climate variability: a comparative study between seven contrasting river basins.

    NASA Astrophysics Data System (ADS)

    Droogers, P.

    2003-04-01

    Climate change and climate variability is and will have a tremendous impact on hydrology and consequently on food security and environmental protection. From the four major components in climate change and climate variability studies, projection, mitigation, impact and adaptation, has the latter so far received less attention than the other three. An international collaboration of ten institutions is comparing adaptation strategies between contrasting basins ranging from wet to dry and from poor to rich. Basins included are: Mekong, Walawe (Sri Lanka), Rhine, Sacramento, Syr Darya, Volta, and Zayandeh (Iran). Simulation models at basin and field scale have been set up and possible adaptation strategies are explored by these models. Preliminary results indicate that appropriate adaptation strategies are different between these seven contrasting basins. It is also clear that these adaptation strategies should focus on increased variability rather than on the overall change of the mean. The focus was hereby not only on an increase in variation but especially on the number of successive dry and wet years. Results show that the studies on these adaptation strategies could not be performed only at one scale, but that a combination of field scale as well as basin scale analysis is essential.

  3. Contrasting clinical outcomes in two cohorts of cats naturally infected with feline immunodeficiency virus (FIV)

    PubMed Central

    Bęczkowski, Paweł M.; Litster, Annette; Lin, Tsang Long; Mellor, Dominic J.; Willett, Brian J.; Hosie, Margaret J.

    2015-01-01

    Despite over 25 years of feline immunodeficiency virus (FIV) research, relatively little is known about the longitudinal course of FIV infection following natural infection. In contrast to published reports of experimental infections using lethal strains of the virus, clinical signs of naturally acquired FIV infection can be mild or inapparent, rather than life-threatening. In this prospective, longitudinal controlled study, based in Chicago, IL (n = 17) and Memphis, TN (n = 27), we investigated two cohorts of privately owned, naturally infected cats kept under different housing conditions. Cats in the Chicago cohort (Group 1) were kept in households of ≤2 cats, while the Memphis cohort (Group 2) comprised part of a large multi-cat household of over 60 cats kept indoors only, with unrestricted access to one another. The majority of cats from Group 1 did not display clinical signs consistent with immunodeficiency during the 22-month observation period. In contrast, the outcome of infection in Group 2 was dramatically different; 17/27 (63%) of cats lost a median of 51.3% of their bodyweight (P < 0.0005) and died during the study period, with lymphoma being the most common cause of mortality. Although the decrease in CD4+ T cell count between enrolment and terminal disease was significant (P = 0.0017), the CD4:CD8 ratio at the time of enrolment did not reliably distinguish FIV-positive cats classified as ‘healthy’ and ‘not healthy’ at either cohort. FIV load at enrolment was significantly lower in Group 1 than in Group 2 (P < 0.0001), but there were no significant differences at enrolment between healthy and not healthy cats at either group. In conclusion, the results of this study suggest that management and housing conditions impact on disease progression and survival times of FIV-positive cats. PMID:25595267

  4. Is nitrogen transfer among plants enhanced by contrasting nutrient-acquisition strategies?

    PubMed

    Teste, François P; Veneklaas, Erik J; Dixon, Kingsley W; Lambers, Hans

    2015-01-01

    Nitrogen (N) transfer among plants has been found where at least one plant can fix N2 . In nutrient-poor soils, where plants with contrasting nutrient-acquisition strategies (without N2 fixation) co-occur, it is unclear if N transfer exists and what promotes it. A novel multi-species microcosm pot experiment was conducted to quantify N transfer between arbuscular mycorrhizal (AM), ectomycorrhizal (EM), dual AM/EM, and non-mycorrhizal cluster-rooted plants in nutrient-poor soils with mycorrhizal mesh barriers. We foliar-fed plants with a K(15) NO3 solution to quantify one-way N transfer from 'donor' to 'receiver' plants. We also quantified mycorrhizal colonization and root intermingling. Transfer of N between plants with contrasting nutrient-acquisition strategies occurred at both low and high soil nutrient levels with or without root intermingling. The magnitude of N transfer was relatively high (representing 4% of donor plant N) given the lack of N2 fixation. Receiver plants forming ectomycorrhizas or cluster roots were more enriched compared with AM-only plants. We demonstrate N transfer between plants of contrasting nutrient-acquisition strategies, and a preferential enrichment of cluster-rooted and EM plants compared with AM plants. Nutrient exchanges among plants are potentially important in promoting plant coexistence in nutrient-poor soils.

  5. Current drug discovery strategies against arenavirus infections.

    PubMed

    Pasquato, Antonella; Burri, Dominique J; Kunz, Stefan

    2012-11-01

    Arenaviruses are a large group of emerging viruses including several causative agents of severe hemorrhagic fevers with high mortality in man. Considering the number of people affected and the currently limited therapeutic options, novel efficacious therapeutics against arenaviruses are urgently needed. Over the past decade, significant advances in knowledge about the basic virology of arenaviruses have been accompanied by the development of novel therapeutics targeting different steps of the arenaviral life cycle. High-throughput, small-molecule screens identified potent and broadly active inhibitors of arenavirus entry that were instrumental for the dissection of unique features of arenavirus fusion. Novel inhibitors of arenavirus replication have been successfully tested in animal models and hold promise for application in humans. Late in the arenavirus life cycle, the proteolytic processing of the arenavirus envelope glycoprotein precursor and cellular factors critically involved virion assembly and budding provide further promising 'druggable' targets for novel therapeutics to combat human arenavirus infection.

  6. Biofilm infections, their resilience to therapy and innovative treatment strategies.

    PubMed

    Römling, U; Balsalobre, C

    2012-12-01

    Biofilm formation of microorganisms causes persistent tissue and foreign body infections resistant to treatment with antimicrobial agents. Up to 80% of human bacterial infections are biofilm associated; such infections are most frequently caused by Staphylococcus epidermidis, Pseudomonas aeruginosa, Staphylococcus aureus and Enterobacteria such as Escherichia coli. The accurate diagnosis of biofilm infections is often difficult, which prevents the appropriate choice of treatment. As biofilm infections significantly contribute to patient morbidity and substantial healthcare costs, novel strategies to treat these infections are urgently required. Nucleotide second messengers, c-di-GMP, (p)ppGpp and potentially c-di-AMP, are major regulators of biofilm formation and associated antibiotic tolerance. Consequently, different components of these signalling networks might be appropriate targets for antibiofilm therapy in combination with antibiotic treatment strategies. In addition, cyclic di-nucleotides are microbial-associated molecular patterns with an almost universal presence. Their conserved structures sensed by the eukaryotic host have a widespread effect on the immune system. Thus, cyclic di-nucleotides are also potential immunotherapeutic agents to treat antibiotic-resistant bacterial infections.

  7. Zernike Phase Contrast Electron Cryo-Tomography Applied to Marine Cyanobacteria Infected with Cyanophages

    PubMed Central

    Dai, Wei; Fu, Caroline; Khant, Htet A.; Ludtke, Steven J.; Schmid, Michael F.; Chiu, Wah

    2015-01-01

    Advances in electron cryo-tomography have provided a new opportunity to visualize the internal 3D structures of a bacterium. An electron microscope equipped with Zernike phase contrast optics produces images with dramatically increased contrast compared to images obtained by conventional electron microscopy. Here we describe a protocol to apply Zernike phase plate technology for acquiring electron tomographic tilt series of cyanophage-infected cyanobacterial cells embedded in ice, without staining or chemical fixation. We detail the procedures for aligning and assessing phase plates for data collection, and methods to obtain 3D structures of cyanophage assembly intermediates in the host, by subtomogram alignment, classification and averaging. Acquiring three to four tomographic tilt series takes approximately 12 h on a JEM2200FS electron microscope. We expect this time requirement to decrease substantially as the technique matures. Time required for annotation and subtomogram averaging varies widely depending on the project goals and data volume. PMID:25321408

  8. Contrastive prevalence of feline retrovirus infections between northern and southern Vietnam.

    PubMed

    Nakamura, K; Miyazawa, T; Ikeda, Y; Sato, E; Nishimura, Y; Nguyen, N T; Takahashi, E; Mochizuki, M; Mikami, T

    2000-08-01

    The prevalence of infections with three feline retroviruses; feline leukemia virus (FeLV), feline immunodeficiency virus (FIV) and feline foamy virus (FeFV), was examined in domestic cats (Felis catus) and leopard cats (Felis bengalensis) in southern Vietnam in 1998. We then compared this data with our previous study in northern Vietnam in 1997. None of the cats had FeLV antigens in both the northern and southern areas. In contrast, there is a great distinction in the seropositivity of FIV. Twenty-two percent of domestic cats had FIV antibodies whereas no FIV positive cats were detected in northern area. FIV may have entered southern Vietnam recently and spread rapidly. FeFV infections were found in both areas, suggesting that FeFV might be present in the cat populations in Vietnam from the earliest time.

  9. Contrasting relatedness patterns in bottlenose dolphins (Tursiops sp.) with different alliance strategies.

    PubMed

    Krützen, Michael; Sherwin, William B; Connor, Richard C; Barré, Lynne M; Van de Casteele, Tom; Mann, Janet; Brooks, Robert

    2003-03-07

    Male bottlenose dolphins (Tursiops sp.) in Shark Bay have one of the most complex male societies outside humans. Two broad mating strategies have been identified in males. In the first strategy, there are two types of alliances: stable 'first-order' pairs and trios that herd individual females in reproductive condition, and 'second-order' teams of two first-order alliances (five or six individuals) that join forces against rivals in contests for females. In the alternative strategy, a 'super-alliance' of ca. 14 individuals, males form pairs or trios to herd females, but in contrast to the stable alliances, these pairs and trios are highly labile. Here, we show that males in stable first-order alliances and the derived second-order alliances are often strongly related, so that they may gain inclusive fitness benefits from alliance membership. By contrast, members of the super-alliance are no more closely related than expected by chance. Further, the strength of the association of alliance partners within the super-alliance, as measured by an index of joint participation in consorting a female, was not correlated with their genetic relatedness. Thus, within one population and one sex, it appears that there may be simultaneous operation of more than one mode of group formation.

  10. Sorghum (Sorghum bicolor) varieties adopt strongly contrasting strategies in response to drought.

    PubMed

    Ogbaga, Chukwuma C; Stepien, Piotr; Johnson, Giles N

    2014-10-01

    Sorghum is one of the most drought tolerant crops but surprisingly, little is known about the mechanisms achieving this. We have compared physiological and biochemical responses to drought in two sorghum cultivars with contrasting drought tolerance. These closely related cultivars have starkly contrasting responses to water deficit. In the less tolerant Samsorg 40, drought induced progressive loss of photosynthesis. The more drought tolerant Samsorg 17 maintained photosynthesis, transpiration and chlorophyll content until the most extreme conditions. In Samsorg 40, there was a highly specific down-regulation of selected proteins, with loss of PSII and Rubisco but maintenance of PSI and cytochrome b6 f, allowing plants to maintain ATP synthesis. The nitrogen released allows for accumulation of glycine betaine and proline. To the best of our knowledge, this is the first example of specific reengineering of the photosynthetic apparatus in response to drought. In contrast, in Samsorg 17 we detected no substantial change in the photosynthetic apparatus. Rather, plants showed constitutively high soluble sugar concentration, enabling them to maintain transpiration and photosynthesis, even in extremely dry conditions. The implications for these strikingly contrasted strategies are discussed in relation to agricultural and natural systems.

  11. Preston M. Hickey memorial lecture. Ionic and nonionic iodinated contrast media: evolution and strategies for use.

    PubMed

    McClennan, B L

    1990-08-01

    The search for better radiopaque iodinated contrast material for intravascular use is continuing, but the recent development of new lower osmolality contrast media (LOCM), both ionic and nonionic, has dramatically affected the practice of radiology. The major issue retarding the introduction of LOCM into clinical practice in this country has been the increased cost of the media. Numerous preliminary assumptions and probabilities about the tolerance, efficacy, and overall safety of LOCM have been documented in scientific studies. The lower osmolality, reduced chemotoxicity, and high hydrophilicity of new compounds, particularly the nonionic variety compared with conventional high osmolality ionic agents (HOCM), offer a significant margin of safety to patients with known risk factors. Mounting data suggest that low or no risk patients are benefited as well, perhaps to an even greater degree. Costly trade-offs to the universal use of LOCM exist, therefore careful consideration of the advantages and disadvantages of LOCM for intravascular administration is required. This article, presented as the Preston M. Hickey Memorial Lecture to the Michigan Radiological Society in March of 1990, explores the historical development of iodinated intravascular contrast media, especially LOCM, and cites existing data that form the basis for various strategies for their use, that is, selective, universal, or nonvascular use. Better, safer, and less expensive contrast media are a realistic expectation in this new decade of technological promise. Reducing adverse side effects from the use of any new drug or technology must be our continued, collective goal.

  12. The role of carbohydrates in infection strategies of enteric pathogens.

    PubMed

    Kato, Kentaro; Ishiwa, Akiko

    2015-03-01

    Enteric pathogens cause considerable public health concerns worldwide including tropical regions. Here, we review the roles of carbohydrates in the infection strategies of various enteric pathogens including viruses, bacteria and protozoa, which infect the epithelial lining of the human and animal intestine. At host cell entry, enteric viruses, including norovirus, recognize mainly histo-blood group antigens. At the initial step of bacterial infections, carbohydrates also function as receptors for attachment. Here, we describe the function of carbohydrates in infection by Salmonella enterica and several bacterial species that produce a variety of fimbrial adhesions. During invasion by enteropathogenic protozoa, apicomplexan parasites utilize sialic acids or sulfated glycans. Carbohydrates serve as receptors for infection by these microbes; however, their usage of carbohydrates varies depending on the microbe. On the surface of the mucosal tissues of the gastrointestinal tract, various carbohydrate moieties are present and play a crucial role in infection, representing the site of infection or route of access for most microbes. During the infection and/or invasion process of the microbes, carbohydrates function as receptors for various microbes, but they can also function as a barrier to infection. One approach to develop effective prophylactic and therapeutic antimicrobial agents is to modify the drug structure. Another approach is to modify the mode of inhibition of infection depending on the individual pathogen by using and mimicking the interactions with carbohydrates. In addition, similarities in mode of infection may also be utilized. Our findings will be useful in the development of new drugs for the treatment of enteric pathogens.

  13. Adaptive strategies in nocturnally migrating insects and songbirds: contrasting responses to wind.

    PubMed

    Chapman, Jason W; Nilsson, Cecilia; Lim, Ka S; Bäckman, Johan; Reynolds, Don R; Alerstam, Thomas

    2016-01-01

    Animals that use flight as their mode of transportation must cope with the fact that their migration and orientation performance is strongly affected by the flow of the medium they are moving in, that is by the winds. Different strategies can be used to mitigate the negative effects and benefit from the positive effects of a moving flow. The strategies an animal can use will be constrained by the relationship between the speed of the flow and the speed of the animal's own propulsion in relation to the surrounding air. Here we analyse entomological and ornithological radar data from north-western Europe to investigate how two different nocturnal migrant taxa, the noctuid moth Autographa gamma and songbirds, deal with wind by analysing variation in resulting flight directions in relation to the wind-dependent angle between the animal's heading and track direction. Our results, from fixed locations along the migratory journey, reveal different global strategies used by moths and songbirds during their migratory journeys. As expected, nocturnally migrating moths experienced a greater degree of wind drift than nocturnally migrating songbirds, but both groups were more affected by wind in autumn than in spring. The songbirds' strategies involve elements of both drift and compensation, providing some benefits from wind in combination with destination and time control. In contrast, moths expose themselves to a significantly higher degree of drift in order to obtain strong wind assistance, surpassing the songbirds in mean ground speed, at the cost of a comparatively lower spatiotemporal migratory precision. Moths and songbirds show contrasting but adaptive responses to migrating through a moving flow, which are fine-tuned to the respective flight capabilities of each group in relation to the wind currents they travel within.

  14. Marriage Strategy of Structure and Composition Designs for Intensifying Ultrasound & MR & CT Trimodal Contrast Imaging.

    PubMed

    Zhang, Kun; Chen, Hangrong; Li, Pei; Bo, Xiaowan; Li, Xiaolong; Zeng, Zeng; Xu, Huixiong

    2015-08-26

    Despite great efforts having been devoted to the design of multimodal imaging probe, almost all design principles of nanotheranostic agents subordinate to simple assemblies of building blocks, resulting in complex preparation process and discounted ability, that is, 1 + 1 < 2. In this report, a novel design strategy, marriage of structure design and composition design that can maximize imaging ability of each building block, ultimately achieving 1 + 1 ≥ 2, has been established. Moreover, a high-efficient ultrasound (US) & MR & CT trimodal contrast agent acts as model to instantiate this design strategy, wherein nanoparticles-induced nonlinear scattering and rattle-type structure-induced double scattering enhancing US imaging, and uniform distribution of Mn(2+) paramagentic centers and "core-satellite" structure of Au atoms favoring enhanced MR imaging and CT imaging, respectively have been validated, achieving optimization of structure design. Importantly, the selected components, silica, Au and MnO are endowed with excellent biocompatibility, displaying the marriage strategy of composition design with aforementioned structure optimization. In in vivo evaluations, such a biocompatible trimodal probe is demonstrated of excellent performance in intensifying CT, MR and US imaging in vivo, especially after positively charged modification by PEI promoting more probes retained in tumor. More importantly, as a universal design strategy, the involved principles in constructing such a US&MR&CT trimodal imaging probe promise great potentials in guiding designs of other materials-based multimodal imaging probe.

  15. Saprolegnia diclina IIIA and S. parasitica employ different infection strategies when colonizing eggs of Atlantic salmon, Salmo salar L.

    PubMed

    Songe, M M; Willems, A; Wiik-Nielsen, J; Thoen, E; Evensen, Ø; van West, P; Skaar, I

    2016-03-01

    Here, we address the morphological changes of eyed eggs of Atlantic salmon, Salmo salar L. infected with Saprolegnia from a commercial hatchery and after experimental infection. Eyed eggs infected with Saprolegnia spp. from 10 Atlantic salmon females were obtained. Egg pathology was investigated by light and scanning electron microscopy. Eggs from six of ten females were infected with S. parasitica, and two females had infections with S. diclina clade IIIA; two Saprolegnia isolates remained unidentified. Light microscopy showed S. diclina infection resulted in the chorion in some areas being completely destroyed, whereas eggs infected with S. parasitica had an apparently intact chorion with hyphae growing within or beneath the chorion. The same contrasting pathology was found in experimentally infected eggs. Scanning electron microscopy revealed that S. parasitica grew on the egg surface and hyphae were found penetrating the chorion of the egg, and re-emerging on the surface away from the infection site. The two Saprolegnia species employ different infection strategies when colonizing salmon eggs. Saprolegnia diclina infection results in chorion destruction, while S. parasitica penetrates intact chorion. We discuss the possibility these infection mechanisms representing a necrotrophic (S. diclina) vs. a facultative biotrophic strategy (S. parasitica).

  16. Targeted Screening Strategies to Detect Trypanosoma cruzi Infection in Children

    PubMed Central

    Levy, Michael Z.; Kawai, Vivian; Bowman, Natalie M.; Waller, Lance A.; Cabrera, Lilia; Pinedo-Cancino, Viviana V.; Seitz, Amy E.; Steurer, Frank J.; Cornejo del Carpio, Juan G.; Cordova-Benzaquen, Eleazar; Maguire, James H.; Gilman, Robert H.; Bern, Caryn

    2007-01-01

    Background Millions of people are infected with Trypanosoma cruzi, the causative agent of Chagas disease in Latin America. Anti-trypanosomal drug therapy can cure infected individuals, but treatment efficacy is highest early in infection. Vector control campaigns disrupt transmission of T. cruzi, but without timely diagnosis, children infected prior to vector control often miss the window of opportunity for effective chemotherapy. Methods and Findings We performed a serological survey in children 2–18 years old living in a peri-urban community of Arequipa, Peru, and linked the results to entomologic, spatial and census data gathered during a vector control campaign. 23 of 433 (5.3% [95% CI 3.4–7.9]) children were confirmed seropositive for T. cruzi infection by two methods. Spatial analysis revealed that households with infected children were very tightly clustered within looser clusters of households with parasite-infected vectors. Bayesian hierarchical mixed models, which controlled for clustering of infection, showed that a child's risk of being seropositive increased by 20% per year of age and 4% per vector captured within the child's house. Receiver operator characteristic (ROC) plots of best-fit models suggest that more than 83% of infected children could be identified while testing only 22% of eligible children. Conclusions We found evidence of spatially-focal vector-borne T. cruzi transmission in peri-urban Arequipa. Ongoing vector control campaigns, in addition to preventing further parasite transmission, facilitate the collection of data essential to identifying children at high risk of T. cruzi infection. Targeted screening strategies could make integration of diagnosis and treatment of children into Chagas disease control programs feasible in lower-resource settings. PMID:18160979

  17. Tuberculosis and HIV co-infection: screening and treatment strategies.

    PubMed

    Venkatesh, Kartik K; Swaminathan, Soumya; Andrews, Jason R; Mayer, Kenneth H

    2011-06-18

    Globally, tuberculosis (TB) and HIV interact in deadly synergy. The high burden of TB among HIV-infected individuals underlies the importance of TB diagnosis, treatment and prevention for clinicians involved in HIV care. Despite expanding access to antiretroviral therapy (ART) to treat HIV infection in resource-limited settings, many individuals in need of therapy initiate ART too late and have already developed clinically significant TB by the time they present for care. Many co-infected individuals are in need of concurrent ART and anti-TB therapy, which dramatically improves survival, but also raises several management challenges, including drug interactions, shared drug toxicities and TB immune reconstitution inflammatory syndrome (IRIS). Due to the survival benefits of promptly initiating ART among all HIV-infected individuals, including those with TB, it is recommended that co-infected individuals receive treatment for both diseases, regardless of CD4+ cell count. We review current screening and treatment strategies for TB and HIV co-infection. Recent findings and ongoing studies will assist clinicians in managing the prevention and treatment of TB and HIV co-infection, which remains a major global health challenge.

  18. Therapeutic and prevention strategies against human enterovirus 71 infection

    PubMed Central

    Kok, Chee Choy

    2015-01-01

    Human enterovirus 71 (HEV71) is the cause of hand, foot and mouth disease and associated neurological complications in children under five years of age. There has been an increase in HEV71 epidemic activity throughout the Asia-Pacific region in the past decade, and it is predicted to replace poliovirus as the extant neurotropic enterovirus of highest global public health significance. To date there is no effective antiviral treatment and no vaccine is available to prevent HEV71 infection. The increase in prevalence, virulence and geographic spread of HEV71 infection over the past decade provides increasing incentive for the development of new therapeutic and prevention strategies against this emerging viral infection. The current review focuses on the potential, advantages and disadvantages of these strategies. Since the explosion of outbreaks leading to large epidemics in China, research in natural therapeutic products has identified several groups of compounds with anti-HEV71 activities. Concurrently, the search for effective synthetic antivirals has produced promising results. Other therapeutic strategies including immunotherapy and the use of oligonucleotides have also been explored. A sound prevention strategy is crucial in order to control the spread of HEV71. To this end the ultimate goal is the rapid development, regulatory approval and widespread implementation of a safe and effective vaccine. The various forms of HEV71 vaccine designs are highlighted in this review. Given the rapid progress of research in this area, eradication of the virus is likely to be achieved. PMID:25964873

  19. Genetic strategy to prevent influenza virus infections in animals.

    PubMed

    Chen, Jianzhu; Chen, Steve C-Y; Stern, Patrick; Scott, Benjamin B; Lois, Carlos

    2008-02-15

    The natural reservoirs of influenza viruses are aquatic birds. After adaptation, avian viruses can acquire the ability to infect humans and cause severe disease. Because domestic poultry serves as a key link between the natural reservoir of influenza viruses and epidemics and pandemics in human populations, an effective measure to control influenza would be to eliminate or reduce influenza virus infection in domestic poultry. The development and distribution of influenza-resistant poultry represents a proactive strategy for controlling the origin of influenza epidemics and pandemics in both poultry and human populations. Recent developments in RNA interference and transgenesis in birds should facilitate the development of influenza-resistant poultry.

  20. Treatment Strategies for Human Arboviral Infections Applicable to Veterinary Medicine

    DTIC Science & Technology

    1992-06-16

    0 Lf Reprintod from Tropical Veterinary Medicine : Current Issues and Perspectives 1• • Volume 653 of the Annals of the New York Academy of Sciences...June 16, 1992 _ Treatment Strategies for Human = __ Arboviral Infections Applicable to I= ’ Veterinary Medicine = ! Chlh. MEIR KENDE (A) U •Department...A 3 0. C . U. 2 * >. U u U>1 it 020 ce*. 0. , -,r- 8 C- ed U a - .; U~u0.M KENDE: HUMAN ARBOVIRAL INFECTIONS AND VETERINARY MEDICINE 299 TABLE 2

  1. Ecosystem service benefits of contrasting conservation strategies in a human-dominated region.

    PubMed

    Eigenbrod, Felix; Anderson, Barbara J; Armsworth, Paul R; Heinemeyer, Andreas; Jackson, Sarah F; Parnell, Mark; Thomas, Chris D; Gaston, Kevin J

    2009-08-22

    The hope among policy-makers and scientists alike is that conservation strategies designed to protect biodiversity also provide direct benefits to people by protecting other vital ecosystem services. The few studies that have examined the delivery of ecosystem services by existing conservation efforts have concentrated on large, 'wilderness'-style biodiversity reserves. However, such reserves are not realistic options for densely populated regions. Here, we provide the first analyses that compare representation of biodiversity and three other ecosystem services across several contrasting conservation strategies in a human-dominated landscape (England). We show that small protected areas and protected landscapes (restrictive zoning) deliver high carbon storage and biodiversity, while existing incentive payment (agri-environment) schemes target areas that offer little advantage over other parts of England in terms of biodiversity, carbon storage and agricultural production. A fourth ecosystem service-recreation-is under-represented by all three strategies. Our findings are encouraging as they illustrate that restrictive zoning can play a major role in protecting natural capital assets in densely populated regions. However, trade-offs exist even among the four ecosystem services we considered, suggesting that a portfolio of conservation and sustainability investments will be needed to deliver both biodiversity and the other ecosystem services demanded by society.

  2. Contrasting energy allocation strategies of two sympatric Merluccius species in an upwelling system.

    PubMed

    Rey, J; Fernandez-Peralta, L; Quintanilla, L F; Hidalgo, M; Presas, C; Salmeron, F; Puerto, M A

    2015-03-01

    This study investigated the somatic growth and energy allocation strategy of two sympatric hake species (Merluccius polli and Merluccius senegalensis), coexisting under the strong influence of the Mauritanian upwelling. The results revealed that ontogeny, bathymetry, geography and reproduction shaped the differences found between the condition dynamics of the two species. Aside from species-specific differences, individuals were observed in better condition in the northernmost area (more influenced by the permanent upwelling) and in the deepest waters, probably the most favourable habitat for Merluccius spp. Both species also displayed contrasting trade-offs in energy allocation probably due to the dissimilarity of their habitats, which favours the existence of divergent adaptive strategies in response to different ontogenic requirements. It was hypothesized that M. polli invests in mass and energy reserves while sacrificing growth, as larger sizes may not provide an ecological advantage in a deeper and more stable environment. Moreover, M. senegalensis capitalizes on a steady growth without major disruptions, enabling earlier spawning at the expense of a lower somatic mass, which is fitting to a less stable shallower environment. This study sheds new light on differences in the biological traits and life strategies of Merluccius spp., which permit their overlap in a complex upwelling system and may contribute to the long-lasting scientific-based management of these species.

  3. Contemporary Diagnostic Strategies for the Detection of Helicobacter pylori Infection

    PubMed Central

    Elfant, Adam B.; Howden, Colin W.; Stollman, Neil

    2012-01-01

    Helicobacter pylori infection is highly prevalent, affecting approximately half of the world’s population. While the majority of infected individuals are asymptomatic, H. pylori infection is associated with certain diseases, including peptic ulcers (either duodenal or gastric), gastritis, and 2 malignancies—gastric cancer and gastric mucosa-associated lymphoid tissue lymphoma. Many of the epidemiologic associations between these diseases and H. pylori infection have been further validated by treatment studies, which show that effective eradication therapy correlates with a decreased risk of disease. A variety of testing strategies are used to detect H. pylori infection. Serologic techniques are widely available and inexpensive, but they are no longer preferred as they have low sensitivities and specificities, and they may show a positive result for a long period following effective therapy. The remaining testing methods are divided into 2 categories: invasive tests (which require endoscopy) and noninvasive tests. Noninvasive test methods such as the urea breath test and stool antigen test have gained popularity due to their high sensitivities and specificities. Further, both of these methods may be used to confirm the absence of infection following eradication therapy. Due to the increasing incidence of treatment failure (caused in part by antibiotic resistance), post-treatment testing is recommended to confirm H. pylori eradication. PMID:24847180

  4. Epidemic spreading on random surfer networks with infected avoidance strategy

    NASA Astrophysics Data System (ADS)

    Feng, Yun; Ding, Li; Huang, Yun-Han; Guan, Zhi-Hong

    2016-12-01

    In this paper, we study epidemic spreading on random surfer networks with infected avoidance (IA) strategy. In particular, we consider that susceptible individuals’ moving direction angles are affected by the current location information received from infected individuals through a directed information network. The model is mainly analyzed by discrete-time numerical simulations. The results indicate that the IA strategy can restrain epidemic spreading effectively. However, when long-distance jumps of individuals exist, the IA strategy’s effectiveness on restraining epidemic spreading is heavily reduced. Finally, it is found that the influence of the noises from information transferring process on epidemic spreading is indistinctive. Project supported in part by the National Natural Science Foundation of China (Grant Nos. 61403284, 61272114, 61673303, and 61672112) and the Marine Renewable Energy Special Fund Project of the State Oceanic Administration of China (Grant No. GHME2013JS01).

  5. Model-Based Simulation and Prediction of an Antiviral Strategy against Influenza A Infection

    PubMed Central

    Hur, Kye-Yeon; Moon, Joon-Young; Kim, Seung-Hwan; Yoo, Joo-Yeon

    2013-01-01

    There is a strong need to develop novel strategies in using antiviral agents to efficiently treat influenza infections. Thus, we constructed a rule-based mathematical model that reflects the complicated interactions of the host immunity and viral life cycle and analyzed the key controlling steps of influenza infections. The main characteristics of the pandemic and seasonal influenza strains were estimated using parameter values derived from cells infected with Influenza A/California/04/2009 and Influenza A/NewCaledonia/20/99, respectively. The quantitative dynamics of the infected host cells revealed a more aggressive progression of the pandemic strain than the seasonal strain. The perturbation of each parameter in the model was then tested for its effects on viral production. In both the seasonal and pandemic strains, the inhibition of the viral release (kC), the reinforcement of viral attachment (kV), and an increased transition rate of infected cells into activated cells (kI) exhibited significant suppression effects on the viral production; however, these inhibitory effects were only observed when the numerical perturbations were performed at the early stages of the infection. In contrast, combinatorial perturbations of both the inhibition of viral release and either the reinforcement of the activation of infected cells or the viral attachment exhibited a significant reduction in the viral production even at a later stage of infection. These results suggest that, in addition to blocking the viral release, a combination therapy that also enhances either the viral attachment or the transition of the infected cells might provide an alternative for effectively controlling progressed influenza infection. PMID:23874556

  6. Variations in Strategies to Prevent Ventriculostomy-Related Infections

    PubMed Central

    Czeisler, Barry M.; Lord, Aaron S.

    2016-01-01

    Background and Purpose: The ideal strategy to prevent infections in patients with external ventricular drains (EVDs) is unclear. Methods: We conducted a cross-sectional survey of members of the Neurocritical Care Society on infection prevention practices for patients with EVDs between April and July 2015. Results: The survey was completed by 52 individuals (5% response rate). Catheter selection, use of prolonged prophylactic systemic antibiotics (PPSAs), cerebrospinal fluid (CSF) collection policies, location of EVD placement, and performance of routine EVD exchanges varied. Antibiotic-impregnated catheters (AICs) and conventional catheters (CCs) were used with similar frequency, but no respondents reported routine use of silver-impregnated catheters (SICs). The majority of respondents were either neutral or disagreed with the need for PPSA with all catheter types (CC: 75%, AIC: 85%, and SIC: 87%). Despite this, 55% of the respondents reported PPSAs were routinely administered to patients with EVDs at their institutions. The majority (80%) of the respondents reported CSF collection only on an as-needed basis. The EVD placement was restricted to the operating room at 27% of the respondents’ institutions. Only 2 respondents (4%) reported that routine EVD exchanges were performed at their institution. Conclusion: Practice patterns demonstrate that institutions use varying strategies to prevent ventriculostomy-related infections. Identification and further study of optimum care for these patients are essential to decrease the risk of complications and to aid development of practice standards. PMID:28042365

  7. Towards a new strategy for the diagnosis of congenital Trypanosoma cruzi infection.

    PubMed

    Abras, Alba; Muñoz, Carmen; Ballart, Cristina; Berenguer, Pere; Llovet, Teresa; Herrero, Mercedes; Tebar, Silvia; Pinazo, María-Jesús; Posada, Elizabeth; Martí, Carmen; Fumadó, Victoria; Bosch, Jordi; Coll, Oriol; Juncosa, Teresa; Ginovart, Gemma; Armengol, Josep; Gascón, Joaquim; Portús, Montserrat; Gállego, Montserrat

    2017-02-15

    The immigration of Latin American women of childbearing age has spread the congenital transmission of Chagas disease to non-endemic areas, and the disease is now a worldwide problem. Some European health authorities have implemented screening programs to prevent vertical transmission, but the lack of a uniform protocol calls for the urgent establishment of a new strategy, common for all laboratories. Our aims were (i) to analyze the trend of passive IgG antibodies in the newborn by means of five serological tests for the diagnosis and follow-up of congenital Trypanosoma cruzi infection, (ii) to assess the utility of these techniques for diagnosing a congenital transmission, and (iii) to propose a strategy for a prompt, efficient and cost-effective diagnosis of T. cruzi infection. In non-infected newborns, a continuous decreasing trend of passive IgG antibodies was observed, but none of the serological assays seroreverted in all the infants before 12 months. From 12 months onwards, serological tests achieved negative results in all the samples analyzed, with the exception of the highly sensitive chemiluminescent microparticle immunoassay (CMIA). In contrast, in congenitally infected infants, the antibody decline was only detected after treatment initiation. In order to improve the diagnosis of congenital T. cruzi infection, we propose a new strategy involving fewer tests that allows significant cost savings. The protocol could start 1 month after birth with a parasitological test and/or a PCR. If negative, a serological test would be carried out at 9 months, which if positive, would be followed by another at around 12 months for confirmation.

  8. Infection Strategies of Intestinal Parasite Pathogens and Host Cell Responses

    PubMed Central

    Di Genova, Bruno M.; Tonelli, Renata R.

    2016-01-01

    Giardia lamblia, Cryptosporidium sp., and Entamoeba histolytica are important pathogenic intestinal parasites and are amongst the leading causes worldwide of diarrheal illness in humans. Diseases caused by these organisms, giardiasis, cryptosporidiosis, and amoebiasis, respectively, are characterized by self-limited diarrhea but can evolve to long-term complications. The cellular and molecular mechanisms underlying the pathogenesis of diarrhea associated with these three pathogens are being unraveled, with knowledge of both the strategies explored by the parasites to establish infection and the methods evolved by hosts to avoid it. Special attention is being given to molecules participating in parasite–host interaction and in the mechanisms implicated in the diseases’ pathophysiologic processes. This review focuses on cell mechanisms that are modulated during infection, including gene transcription, cytoskeleton rearrangements, signal transduction pathways, and cell death. PMID:26973630

  9. Automated identification of retinal vessels using a multiscale directional contrast quantification (MDCQ) strategy

    SciTech Connect

    Zhen, Yi; Zhang, Xinyuan; Wang, Ningli E-mail: puj@upmc.edu; Gu, Suicheng; Meng, Xin; Zheng, Bin; Pu, Jiantao E-mail: puj@upmc.edu

    2014-09-15

    Purpose: A novel algorithm is presented to automatically identify the retinal vessels depicted in color fundus photographs. Methods: The proposed algorithm quantifies the contrast of each pixel in retinal images at multiple scales and fuses the resulting consequent contrast images in a progressive manner by leveraging their spatial difference and continuity. The multiscale strategy is to deal with the variety of retinal vessels in width, intensity, resolution, and orientation; and the progressive fusion is to combine consequent images and meanwhile avoid a sudden fusion of image noise and/or artifacts in space. To quantitatively assess the performance of the algorithm, we tested it on three publicly available databases, namely, DRIVE, STARE, and HRF. The agreement between the computer results and the manual delineation in these databases were quantified by computing their overlapping in both area and length (centerline). The measures include sensitivity, specificity, and accuracy. Results: For the DRIVE database, the sensitivities in identifying vessels in area and length were around 90% and 70%, respectively, the accuracy in pixel classification was around 99%, and the precisions in terms of both area and length were around 94%. For the STARE database, the sensitivities in identifying vessels were around 90% in area and 70% in length, and the accuracy in pixel classification was around 97%. For the HRF database, the sensitivities in identifying vessels were around 92% in area and 83% in length for the healthy subgroup, around 92% in area and 75% in length for the glaucomatous subgroup, around 91% in area and 73% in length for the diabetic retinopathy subgroup. For all three subgroups, the accuracy was around 98%. Conclusions: The experimental results demonstrate that the developed algorithm is capable of identifying retinal vessels depicted in color fundus photographs in a relatively reliable manner.

  10. Immunotherapeutic strategies in the treatment of HIV infection and AIDS.

    PubMed

    Birx, D L; Redfield, R R

    1993-08-01

    The immune response against HIV does not result in complete viral clearance. Recent interventions have focused on novel strategies to modify human anti-HIV immunity. Active vaccination of patients with HIV infection (vaccine therapy) safely alters the immune repertoire against HIV. This unique approach will provide insight into the immunoregulatory consequences of HIV-specific innate and adaptive immune responses, and hopefully define the immunological Achilles heel of HIV. Once defined, researchers, aided by current biotechnological techniques, can rationally design future vaccines and immune based therapeutic products.

  11. New molecular strategies for reducing implantable medical devices associated infections.

    PubMed

    Holban, Alina Maria; Gestal, Monica Cartelle; Grumezescu, Alexandru Mihai

    2014-01-01

    Due to the great prevalence of persistent and recurrent implanted device associated-infections novel and alternative therapeutic approaches are intensely investigated. For reducing complications and antibiotic resistance development, one major strategy is using natural or synthetic modulators for targeting microbial molecular pathways which are not related with cell multiplication and death, as Quorum Sensing, virulence and biofilm formation. The purpose of this review paper is to discuss the most recent in vitro approaches, investigating the efficiency of some novel antimicrobial products and the nano-technologic progress performed in order to increase their effect and stability.

  12. Contrasting drought tolerance strategies in two desert annuals of hybrid origin

    PubMed Central

    Rosenthal, David M.; Stiller, Volker; Sperry, John S.; Donovan, Lisa A.

    2010-01-01

    Woody plants native to mesic habitats tend to be more vulnerable to drought-induced cavitation than those in xeric habitats. Cavitation resistance in herbaceous plants, however, is rarely studied and whether or not annual plants in arid habitats conform to the trends observed in woody plants is unknown. This question is addressed by comparing the hydraulic properties of annual plants endemic to relatively mesic and seasonally xeric habitats in the Great Basin Desert, in both native and experimental settings. Vulnerability to cavitation between species differed as predicted when vulnerability curves of similar-sized native individuals were compared. Contrary to expectations, Helianthus anomalus from the relatively mesic dune sites, on average, exhibited higher native embolism, lower soil-to-leaf hydraulic conductance (kL) and lower transpiration rates, than its xeric analogue, H. deserticola. In transplant gardens, H. anomalus’ vulnerability to cavitation was unaffected by transplant location or watering treatment. In H. deserticola, however, vulnerability to cavitation varied significantly in response to watering in transplant gardens and varied as a function of stem water potential (Ψstem). H. deserticola largely avoided cavitation through its higher water status and generally more resistant xylem, traits consistent with a short life cycle and typical drought-escape strategy. By contrast, H. anomalus’ higher native embolism is likely to be adaptive by lowering plant conductance and transpiration rate, thus preventing the loss of root-to-soil hydraulic contact in the coarse sand dune soils. For H. anomalus this dehydration avoidance strategy is consistent with its relatively long 3–4 month life cycle and low-competition habitat. We conclude that variance of hydraulic parameters in herbaceous plants is a function of soil moisture heterogeneity and is consistent with the notion that trait plasticity to fine-grained environmental variation can be adaptive. PMID

  13. Production and robustness of a Cacao agroecosystem: effects of two contrasting types of management strategies.

    PubMed

    Sabatier, Rodolphe; Wiegand, Kerstin; Meyer, Katrin

    2013-01-01

    Ecological intensification, i.e. relying on ecological processes to replace chemical inputs, is often presented as the ideal alternative to conventional farming based on an intensive use of chemicals. It is said to both maintain high yield and provide more robustness to the agroecosystem. However few studies compared the two types of management with respect to their consequences for production and robustness toward perturbation. In this study our aim is to assess productive performance and robustness toward diverse perturbations of a Cacao agroecosystem managed with two contrasting groups of strategies: one group of strategies relying on a high level of pesticides and a second relying on low levels of pesticides. We conducted this study using a dynamical model of a Cacao agroecosystem that includes Cacao production dynamics, and dynamics of three insects: a pest (the Cacao Pod Borer, Conopomorpha cramerella) and two characteristic but unspecified beneficial insects (a pollinator of Cacao and a parasitoid of the Cacao Pod Borer). Our results showed two opposite behaviors of the Cacao agroecosystem depending on its management, i.e. an agroecosystem relying on a high input of pesticides and showing low ecosystem functioning and an agroecosystem with low inputs, relying on a high functioning of the ecosystem. From the production point of view, no type of management clearly outclassed the other and their ranking depended on the type of pesticide used. From the robustness point of view, the two types of managements performed differently when subjected to different types of perturbations. Ecologically intensive systems were more robust to pest outbreaks and perturbations related to pesticide characteristics while chemically intensive systems were more robust to Cacao production and management-related perturbation.

  14. Contrasting drought tolerance strategies in two desert annuals of hybrid origin.

    PubMed

    Rosenthal, David M; Stiller, Volker; Sperry, John S; Donovan, Lisa A

    2010-06-01

    Woody plants native to mesic habitats tend to be more vulnerable to drought-induced cavitation than those in xeric habitats. Cavitation resistance in herbaceous plants, however, is rarely studied and whether or not annual plants in arid habitats conform to the trends observed in woody plants is unknown. This question is addressed by comparing the hydraulic properties of annual plants endemic to relatively mesic and seasonally xeric habitats in the Great Basin Desert, in both native and experimental settings. Vulnerability to cavitation between species differed as predicted when vulnerability curves of similar-sized native individuals were compared. Contrary to expectations, Helianthus anomalus from the relatively mesic dune sites, on average, exhibited higher native embolism, lower soil-to-leaf hydraulic conductance (k(L)) and lower transpiration rates, than its xeric analogue, H. deserticola. In transplant gardens, H. anomalus' vulnerability to cavitation was unaffected by transplant location or watering treatment. In H. deserticola, however, vulnerability to cavitation varied significantly in response to watering in transplant gardens and varied as a function of stem water potential (Psi(stem)). H. deserticola largely avoided cavitation through its higher water status and generally more resistant xylem, traits consistent with a short life cycle and typical drought-escape strategy. By contrast, H. anomalus' higher native embolism is likely to be adaptive by lowering plant conductance and transpiration rate, thus preventing the loss of root-to-soil hydraulic contact in the coarse sand dune soils. For H. anomalus this dehydration avoidance strategy is consistent with its relatively long 3-4 month life cycle and low-competition habitat. We conclude that variance of hydraulic parameters in herbaceous plants is a function of soil moisture heterogeneity and is consistent with the notion that trait plasticity to fine-grained environmental variation can be adaptive.

  15. Production and Robustness of a Cacao Agroecosystem: Effects of Two Contrasting Types of Management Strategies

    PubMed Central

    Sabatier, Rodolphe; Wiegand, Kerstin; Meyer, Katrin

    2013-01-01

    Ecological intensification, i.e. relying on ecological processes to replace chemical inputs, is often presented as the ideal alternative to conventional farming based on an intensive use of chemicals. It is said to both maintain high yield and provide more robustness to the agroecosystem. However few studies compared the two types of management with respect to their consequences for production and robustness toward perturbation. In this study our aim is to assess productive performance and robustness toward diverse perturbations of a Cacao agroecosystem managed with two contrasting groups of strategies: one group of strategies relying on a high level of pesticides and a second relying on low levels of pesticides. We conducted this study using a dynamical model of a Cacao agroecosystem that includes Cacao production dynamics, and dynamics of three insects: a pest (the Cacao Pod Borer, Conopomorpha cramerella) and two characteristic but unspecified beneficial insects (a pollinator of Cacao and a parasitoid of the Cacao Pod Borer). Our results showed two opposite behaviors of the Cacao agroecosystem depending on its management, i.e. an agroecosystem relying on a high input of pesticides and showing low ecosystem functioning and an agroecosystem with low inputs, relying on a high functioning of the ecosystem. From the production point of view, no type of management clearly outclassed the other and their ranking depended on the type of pesticide used. From the robustness point of view, the two types of managements performed differently when subjected to different types of perturbations. Ecologically intensive systems were more robust to pest outbreaks and perturbations related to pesticide characteristics while chemically intensive systems were more robust to Cacao production and management-related perturbation. PMID:24312469

  16. Provoking "Eureka" moments for effective infection control strategies.

    PubMed

    Pittet, Didier

    2014-01-01

    Safety is now a fundamental principle of patient care and a critical component of quality management. Health care-associated infection prevention strategies need to be constantly revisited and updated to be effective. The "Geneva hand hygiene model" is a typical example of a breakthrough innovatory campaign that caught fire and went viral worldwide, thanks to its adoption by the World Health Organization (WHO) as the First Global Patient Safety Challenge. The campaign remains an inspiration for further innovation. To encourage new and disruptive technologies with the potential to improve patient safety through the successful implementation of the WHO multimodal strategy, the University of Geneva Hospitals/WHO Collaborating Centre on Patient Safety, together with the Aesculap Academy, have created a series of "Hand Hygiene Excellence Awards" and "Hand Hygiene Innovation Awards" worldwide.

  17. Contrasting strategies to cope with drought conditions by two tropical forage C4 grasses

    PubMed Central

    Cardoso, Juan Andrés; Pineda, Marcela; Jiménez, Juan de la Cruz; Vergara, Manuel Fernando; Rao, Idupulapati M.

    2015-01-01

    Drought severely limits forage productivity of C4 grasses across the tropics. The avoidance of water deficit by increasing the capacity for water uptake or by controlling water loss are common responses in forage C4 grasses. Napier grass (Pennisetum purpureum) and Brachiaria hybrid cv. Mulato II are tropical C4 grasses used for livestock production due to their reputed resistance to drought conditions. However, there is scant information on the mechanisms used by these grasses to overcome water-limited conditions. Therefore, assessments of cumulative transpired water, shoot growth, leaf rolling, leaf gas exchange, dry mass production and a number of morpho-physiological traits were recorded over a period of 21 days under well-watered or drought conditions. Drought reduced shoot dry mass of both grasses by 35 %, yet each grass exhibited contrasting strategies to cope with water shortage. Napier grass transpired most available water by the end of the drought treatment, whereas a significant amount of water was still available for Mulato II. Napier grass maintained carbon assimilation until the soil was fairly dry, whereas Mulato II restricted water loss by early stomatal closure at relatively wet soil conditions. Our results suggest that Napier grass exhibits a ‘water-spending’ behaviour that might be targeted to areas with intermittent drought stress, whereas Mulato II displays a ‘water-saving’ nature that could be directed to areas with longer dry periods. PMID:26333827

  18. Grapevine Pathogenic Microorganisms: Understanding Infection Strategies and Host Response Scenarios

    PubMed Central

    Armijo, Grace; Schlechter, Rudolf; Agurto, Mario; Muñoz, Daniela; Nuñez, Constanza; Arce-Johnson, Patricio

    2016-01-01

    Grapevine (Vitis vinifera L.) is one of the most important fruit crop worldwide. Commercial cultivars are greatly affected by a large number of pathogenic microorganisms that cause diseases during pre- and/or post-harvest periods, affecting production, processing and export, along with fruit quality. Among the potential threats, we can find bacteria, fungi, oomycete, or viruses with different life cycles, infection mechanisms and evasion strategies. While plant–pathogen interactions are cycles of resistance and susceptibility, resistance traits from natural resources are selected and may be used for breeding purposes and for a sustainable agriculture. In this context, here we summarize some of the most important diseases affecting V. vinifera together with their causal agents. The aim of this work is to bring a comprehensive review of the infection strategies deployed by significant types of pathogens while understanding the host response in both resistance and susceptibility scenarios. New approaches being used to uncover grapevine status during biotic stresses and scientific-based procedures needed to control plant diseases and crop protection are also addressed. PMID:27066032

  19. Pestilence, persistence and pathogenicity: infection strategies of Bartonella

    PubMed Central

    Minnick, Michael F; Battisti, James M

    2009-01-01

    It has been nearly two decades since the discovery of Bartonella as an agent of bacillary angiomatosis in AIDS patients and persistent bacteremia and ‘nonculturable’ endocarditis in homeless people. Since that time, the number of Bartonella species identified has increased from one to 24, and 10 of these bacteria are associated with human disease. Although Bartonella is the only genus that infects human erythrocytes and triggers pathological angiogenesis in the vascular bed, the group remains understudied compared with most other bacterial pathogens. Numerous questions regarding Bartonella's molecular pathogenesis and epidemiology remain unanswered. Virtually every mammal harbors one or more Bartonella species and their transmission typically involves a hematophagous arthropod vector. However, many details regarding epidemiology and the public health threat imposed by these animal reservoirs is unclear. A handful of studies have shown that bartonellae are highly-adapted pathogens whose parasitic strategy has evolved to cause persistent infections of the host. To this end, virulence attributes of Bartonella include the subversion of host cells with effector molecules delivered via a type IV secretion system, induction of pathological angiogenesis through various means, including inhibition of apoptosis and activation of hypoxia-inducing factor 1, use of afimbrial adhesins that are orthologs of Yersinia adhesin A, incorporation of lipopolysaccharides with low endotoxic potency in the outer membrane, and several other virulence factors that help Bartonella infect and persist in erythrocytes and endothelial cells of the host circulatory system. PMID:19659429

  20. Attacking HIV provirus: therapeutic strategies to disrupt persistent infection.

    PubMed

    Margolis, David M; Archin, Nancy M

    2006-12-01

    The therapeutic armamentarium for human immunodeficiency virus type 1 (HIV-1) infection continues to expand. New targets such as entry and integration have recently been successfully exploited. However, HIV-infected patients in need of treatment are currently committed to lifelong suppressive therapy. The persistence of integrated HIV DNA genomes capable of producing virus is a fundamental obstacle to the eradication or cure of HIV infection. Rational molecular or pharmacologic strategies to eliminate persistent HIV proviral genomes are an unaddressed therapeutic need. Coupled with potent antiretroviral therapy, treatments that could efficiently deplete the persistent DNA reservoir of HIV could radically alter treatment paradigms. Prior attempts to target persistent proviral infection deployed intensive antiretroviral therapy (ART) in combination with global inducers of T-cell activation. Initial trials of this approach were unsuccessful. Non-specific T-cell activation may induce high-level viral replication above a level that can be fully contained by ART, while increasing the susceptibility of uninfected cells. Selective targeting of HIV provirus via agents that induce the expression of quiescent HIV, but have limited effects on the uninfected host cell is an alternate approach to attack latent HIV. Recent studies define the role of repressive chromatin structure in maintaining HIV quiescence, and suggest that mechanisms that remodel chromatin about the HIV promoter are a possible therapeutic target. Other studies have uncovered specific factors that may act to induce or maintain latency by limiting the efficiency of HIV gene expression. Attempts to deplete latent HIV using drugs that alter chromatin structure have entered clinical study.

  1. Contrasting Transcriptional Responses of a Virulent and an Attenuated Strain of Mycobacterium tuberculosis Infecting Macrophages

    PubMed Central

    Hinds, Jason; Malloff, Chad A.; Bains, Manjeet; Hancock, Robert E.; Lam, Wan L.

    2010-01-01

    Background H37Rv and H37Ra are well-described laboratory strains of Mycobacterium tuberculosis derived from the same parental strain, H37, that show dramatically different pathogenic phenotypes. Methodology/Principal Findings In this study, the transcriptomes of the two strains during axenic growth in broth and during intracellular growth within murine bone-marrow macrophages were compared by whole genome expression profiling. We identified and compared adaptations of either strain upon encountering an intracellular environment, and also contrasted the transcriptomes of the two strains while inside macrophages. In the former comparison, both strains induced genes that would facilitate intracellular survival including those involved in mycobactin synthesis and fatty acid metabolism. However, this response was stronger and more extensive for H37Rv than for H37Ra. This was manifested as the differential expression of a greater number of genes and an increased magnitude of expression for these genes in H37Rv. In comparing intracellular transcriptional signatures, fifty genes were found to be differentially expressed between the strains. Of these fifty, twelve were under control of the PhoPR regulon. Further differences between strains included genes whose products were members of the ESAT-6 family of proteins, or were associated with their secretion. Conclusions/Significance Along with the recent identification of single nucleotide polymorphisms in H37Ra when compared to H37Rv, our demonstration of differential expression of PhoP-regulated and ESX-1 region-related genes during macrophage infection further highlights the significance of these genes in the attenuation of H37Ra. PMID:20548782

  2. Different biomechanical design and ecophysiological strategies in juveniles of two liana species with contrasting growth habit.

    PubMed

    Chen, Ya-Jun; Bongers, Frans; Zhang, Jiao-Lin; Liu, Jin-Yu; Cao, Kun-Fang

    2014-06-01

    • Premise of the study: Lianas constitute a major functional type in tropical zones. While some liana species start climbing immediately after germination (shade-avoidance), others have a long self-supporting phase (shade-tolerance). The morphophysiological characteristics of these two growth habits are unknown.• Methods: We quantified growth traits, biomass allocation, mechanics, anatomy, and hydraulics for saplings of Ventilago calyculata (an immediate obligate climber) and Ziziphus attopensis (having a long self-supporting phase), both in the family Rhamnaceae. The mechanics, anatomy, and hydraulics for the mature individuals of the two species were also evaluated.• Key results: In the juvenile stage, V. calyculata had a higher slenderness ratio, height growth rate, and photosynthetic rate but similar biomass growth rate compared with Z. attopensis. In contrast, Z. attopensis had a higher leaf area growth rate, specific leaf area, and leaf mass fraction. Ziziphus attopensis had stiffer, but less conductive stems than V. calyculata. Stem rigidity of saplings decreased from base to apex in Z. attopensis, but increased in V. calyculata. Both species had similar resistance to xylem embolism. However, the leaves of V. calyculata were able to resist greater water deficits. At the mature stage, wider and longer vessels emerged in the xylem, and both species increased stem specific conductivity and drought resistance in stems and leaves. Ventilago calyculata had significantly higher specific conductivity and was more drought tolerant than Z. attopensis.• Conclusions: The two lianas differed significantly in growth, biomass allocation, anatomy, mechanics, ecophysiology, and hydraulic properties in line with their growth habits and shade adaptation strategies.

  3. Carbon rhizodeposition by plants of contrasting strategies for resource acquisition: responses to various nitrogen fertility regimes

    NASA Astrophysics Data System (ADS)

    Baptist, Florence; Aranjuelo, I.; Lopez-Sangil, L.; Rovia, P.; Nogués, S.

    2010-05-01

    Rhizodeposition by plants is one of the most important physiological mechanisms related to carbon and nitrogen cycling which is also believed to vary along the acquisition-conservation continuum. However, owing to methodological difficulties (i.e. narrow zone of soil around roots and rapid assimilation by soil microbes), root exudation and variations between species are one of the most poorly understood belowground process. Although previous approaches such as hydroponic culture based system, permit the chemical analysis of exudates, the fact that this protocol is qualitative, conditions its utility (see review in Phillips et al. 2008). Others techniques based on pulse-labelling approach have been developed to quantify rhizodeposition but are rarely sufficient to uniformly label all plant inputs to soil. Consequently with this typical pulse chase methods, recent assimilates are labeled but the recalcitrant carbon will not be labeled and therefore the contribution of this carbon will not be considered. Hence, traditional pulse labelling is not a quantitative means of tracing carbon due to inhomogeneous labelling and so limits greatly comparative studies of rhizodeposition fluxes at the interspecific level. In this study we developped a new protocole based on a long-term (3 months) steady state 13C labelling in order (1) to quantify rhizodeposition fluxes for six graminoid species caracterized by contrasted nutrient acquisition strategies and (2) to investigate to what extent various level of nitrogen fertility regimes modulate rhizodeposition fluxes. This method will enable to quantify under natural soil conditions both the accumulation of 13C in the soil but also the quantity that has been respired by the microorganisms during a given time and so will give an integrated picture of rhizodeposition fluxes for each species under each nitrogen fertility level. Results are currently being processed and will be presented at the conference. References: Phillips RP, Erlitz

  4. Different patterns of oviposition learning in two closely related ectoparasitoid wasps with contrasting reproductive strategies.

    PubMed

    Sasakawa, Kôji; Uchijima, Kenta; Shibao, Harunobu; Shimada, Masakazu

    2013-02-01

    Many parasitoid wasps learn host-associated cues and use them in subsequent host-searching behavior. This associative learning, namely "oviposition learning," has been investigated in many studies. However, few studies have compared multiple species, and no comparative study has previously been conducted on ectoparasitoid species. We compared the effects of oviposition learning on host preference and offspring sex ratio in two closely related ectoparasitoid wasps with contrasting reproductive strategies, Anisopteromalus calandrae (r-strategist) and its sibling species (K-strategist). Using two bruchine hosts, Callosobruchus chinensis and Callosobruchus maculatus larvae infesting the cowpea Vigna unguiculata, oviposition choice experiments were performed at high and low host densities. In both species, no conspicuous effect on the offspring sex ratio was detected, but effects on host preference were found to differ between the species. In A. calandrae, the effects were detected only at high host density, suggesting that oviposition learning plays a role in host discrimination from a short distance but not from a long distance. In the sibling species, those effects were not detected in any of the cases, suggesting the absence of oviposition learning. These results are compatible with those of previous comparative studies of endoparasitoid wasps in that few lifetime oviposition experiences and/or low reward per foraging decision result in low or absent oviposition learning ability. This finding may indicate that ecological traits contributing to learning ability are similar between endoparasitoid and ectoparasitoid wasps. Thus, our species comparison of ectoparasitoids provides another model system for investigating learning and memory dynamics in parasitoid wasps.

  5. Monitoring strategies of stream phosphorus under contrasting climate-driven flow regimes

    NASA Astrophysics Data System (ADS)

    Goyenola, G.; Meerhoff, M.; Teixeira-de Mello, F.; González-Bergonzoni, I.; Graeber, D.; Fosalba, C.; Vidal, N.; Mazzeo, N.; Ovesen, N. B.; Jeppesen, E.; Kronvang, B.

    2015-10-01

    Climate and hydrology are relevant control factors determining the timing and amount of nutrient losses from land to downstream aquatic systems, in particular of phosphorus (P) from agricultural lands. The main objective of the study was to evaluate the differences in P export patterns and the performance of alternative monitoring strategies in streams under contrasting climate-driven flow regimes. We compared a set of paired streams draining lowland micro-catchments under temperate climate and stable discharge conditions (Denmark) and under sub-tropical climate and flashy conditions (Uruguay). We applied two alternative nutrient sampling programs (high-frequency composite sampling and low-frequency instantaneous-grab sampling) and estimated the contribution derived from point and diffuse sources fitting a source apportionment model. We expected to detect a pattern of higher total and particulate phosphorus export from diffuse sources in streams in Uruguay streams, mostly as a consequence of higher variability in flow regime (higher flashiness). Contrarily, we found a higher contribution of dissolved P in flashy streams. We did not find a notably poorer performance of the low-frequency sampling program to estimate P exports in flashy streams compared to the less variable streams. We also found signs of interaction between climate/hydrology and land use intensity, in particular in the presence of point sources of P, leading to a bias towards underestimation of P in hydrologically stable streams and overestimation of P in flashy streams. Based on our findings, we suggest that the evaluation and use of more accurate monitoring methods, such as automatized flow-proportional water samplers and automatized bankside analyzers, should be prioritized whenever logistically possible. However, it seems particularly relevant in currently flashy systems and also in systems where climate change predictions suggest an increase in stream flashiness.

  6. Different patterns of oviposition learning in two closely related ectoparasitoid wasps with contrasting reproductive strategies

    NASA Astrophysics Data System (ADS)

    Sasakawa, Kôji; Uchijima, Kenta; Shibao, Harunobu; Shimada, Masakazu

    2013-02-01

    Many parasitoid wasps learn host-associated cues and use them in subsequent host-searching behavior. This associative learning, namely "oviposition learning," has been investigated in many studies. However, few studies have compared multiple species, and no comparative study has previously been conducted on ectoparasitoid species. We compared the effects of oviposition learning on host preference and offspring sex ratio in two closely related ectoparasitoid wasps with contrasting reproductive strategies, Anisopteromalus calandrae (r-strategist) and its sibling species (K-strategist). Using two bruchine hosts, Callosobruchus chinensis and Callosobruchus maculatus larvae infesting the cowpea Vigna unguiculata, oviposition choice experiments were performed at high and low host densities. In both species, no conspicuous effect on the offspring sex ratio was detected, but effects on host preference were found to differ between the species. In A. calandrae, the effects were detected only at high host density, suggesting that oviposition learning plays a role in host discrimination from a short distance but not from a long distance. In the sibling species, those effects were not detected in any of the cases, suggesting the absence of oviposition learning. These results are compatible with those of previous comparative studies of endoparasitoid wasps in that few lifetime oviposition experiences and/or low reward per foraging decision result in low or absent oviposition learning ability. This finding may indicate that ecological traits contributing to learning ability are similar between endoparasitoid and ectoparasitoid wasps. Thus, our species comparison of ectoparasitoids provides another model system for investigating learning and memory dynamics in parasitoid wasps.

  7. Preventive strategy for BVDV infection in North America.

    PubMed

    Ridpath, Julia

    2012-02-01

    Despite 60 years of vaccination, bovine viral diarrhea virus (BVDV) infections remain a source of significant economic loss for producers in the United States. Control program design in the United States varies by region based on the incidence of BVDV, density of animal populations, animal movement, contact with wildlife populations, level of producer compliance, variation among circulating BVDV strains, prevalent type of production unit or industry and support offered by state institutions. The Upper Peninsula BVDV Eradication Program in Michigan, the Montana BVD-PI Herd Biosecurity Project, the Washington State BVDV Testing program and the Alabama Voluntary BVD Control Program illustrates four different regional approaches. All four programs are voluntary rather than government mandated and a large component of each was the identification and removal of animals persistently infected with BVDV. The Washington, Montana and Alabama programs focus on herd screening to eliminate PI's but did not have eradication as a goal. The Michigan program was unique in that its goal was to eradicate BVDV from a defined geographic region. While the Washington, Alabama and Montana programs were beneficial to individual producers they did not have a significant impact on the prevalence of BVDV. In contrast, the Michigan program has reduced incidence of herds harboring PI animals in the region. Organizers of all four programs noted that compliance with control programs was directly linked to education and the presence of a support network composed of fellow producers, engaged veterinarians and knowledgeable diagnosticians.

  8. Strategies for prevention of ultrasound-guided prostate biopsy infections

    PubMed Central

    Lu, Diane D; Raman, Jay D

    2016-01-01

    Prostate cancer is the most common cancer in male patients and the second leading cause of cancer-related mortality in males. To confirm the diagnosis of prostate cancer, an ultrasound-guided needle biopsy is necessary to obtain prostate tissue sufficient for histologic analysis by pathologists. Ultrasound-guided prostate needle biopsy can be accomplished via a transperineal or transrectal approach. The latter biopsy technique involves placing an ultrasound probe into the rectum, visualizing the prostate located just anterior to it, and then obtaining 12–14 biopsies. Each biopsy core requires piercing of the rectal mucosa which can inherently contribute to infection. The increasing infectious risk of prostate needle biopsy requires refinement and re-evaluation of the process in which the technique is performed. Such processes include (but are not limited to) prebiopsy risk stratification, antibiotic prophylaxis, use of rectal preparations, and equipment processing. In the subsequent review, we highlight the current available information on different strategies to reduce the risk of infection following prostate needle biopsy. PMID:27468242

  9. A Conserved Potential Development Framework Applies to Shoots of Legume Species with Contrasting Morphogenetic Strategies

    PubMed Central

    Faverjon, Lucas; Escobar-Gutiérrez, Abraham J.; Litrico, Isabelle; Louarn, Gaëtan

    2017-01-01

    A great variety of legume species are used for forage production and grown in multi-species grasslands. Despite their close phylogenetic relationship, they display a broad range of morphologies that markedly affect their competitive abilities and persistence in mixtures. Little is yet known about the component traits that control the deployment of plant architecture in most of these species. During the present study, we compared the patterns of shoot organogenesis and shoot organ growth in contrasting forage species belonging to the four morphogenetic groups previously identified in herbaceous legumes (i.e., stolon-formers, rhizome-formers, crown-formers tolerant to defoliation and crown-formers intolerant to defoliation). To achieve this, three greenhouse experiments were carried out using plant species from each group (namely alfalfa, birdsfoot trefoil, sainfoin, kura clover, red clover, and white clover) which were grown at low density under non-limiting water and soil nutrient availability. The potential morphogenesis of shoots characterized under these conditions showed that all the species shared a number of common morphogenetic features. All complied with a generalized classification of shoot axes into three types (main axis, primary and secondary axes). A common quantitative framework for vegetative growth and development involved: (i) the regular development of all shoot axes in thermal time and a deterministic branching pattern in the absence of stress; (ii) a temporal coordination of organ growth at the phytomer level that was highly conserved irrespective of phytomer position, and (iii) an identical allometry determining the surface area of all the leaves. The species differed in their architecture as a consequence of the values taken by component traits of morphogenesis. Assessing the relationships between the traits studied showed that these species were distinct from each other along two main PCA axes which explained 68% of total variance: the first

  10. Novel agents and strategies to treat herpes simplex virus infections.

    PubMed

    Kleymann, Gerald

    2003-02-01

    The quiet pandemic of herpes simplex virus (HSV) infection has plagued humanity since ancient times, causing mucocutaneous infection, such as herpes labialis and herpes genitalis. Disease symptoms often interfere with everyday activities and occasionally HSV infections are the cause of life-threatening or sight-impairing disease, especially in neonates and the immunocompromised patient population. After primary or initial infection the virus persists for life in a latent form in neurons of the host, periodically reactivating and often resulting in significant psychosocial distress for the patient. Currently, no cure is available. In the mid-1950s the first antiviral, idoxuridine, was developed for topical treatment of herpes disease and, in 1978, vidarabine was licensed for systemic use to treat HSV encephalitis. Acyclovir (Zovirax), a potent, specific and tolerable nucleosidic inhibitor of the herpes DNA polymerase, was a milestone in the development of antiviral drugs in the late 1970s. In the mid-1990s, when acyclovir became a generic drug, valacyclovir (Valtrex) and famciclovir (Famvir), prodrugs of the gold standard and penciclovir (Denavir), Vectavir), a close analogue, were launched. Though numerous approaches and strategies were tested and considerable effort was expended in the search of the next generation of an antiherpetic therapy, it proved difficult to outperform acyclovir. Notable in this regard was the award of a Nobel Prize in 1988 for the elucidation of mechanistic principles which resulted in the development of new drugs such as acyclovir. Vaccines, interleukins, interferons, therapeutic proteins, antibodies, immunomodulators and small-molecule drugs with specific or nonspecific modes of action lacked either efficacy or the required safety profile to replace the nucleosidic drugs acyclovir, valacyclovir, penciclovir and famciclovir as the first choice of treatment. Recently though, new inhibitors of the HSV helicase-primase with potent in vitro

  11. Transfer of Learning Strategies: Contrast of Self-Instructional and Traditional Training Formats with EMR Children.

    ERIC Educational Resources Information Center

    Borkowski, John G.; Varnhagen, Connie Kendall

    1984-01-01

    Twelve mentally retarded children were taught anticipation and paraphase strategies imbedded in either a self-instructional format or a traditional didactic training format. Six Ss in a control condition received no explicit strategy instructions. Although no differences were found for self-instructional vs. traditional training formats, both…

  12. A bundle strategy including patient hand hygiene to decrease clostridium difficile infections.

    PubMed

    Pokrywka, Marian; Feigel, Jody; Douglas, Barbara; Grossberger, Susan; Hensler, Amelia; Hensler, Amelia; Weber, David

    2014-01-01

    Prevention strategies for Clostridium difficile infection traditionally have addressed barrier precautions, environmental disinfection, and health care worker hand hygiene. When applied as a bundle, this approach has been used widely as an evidence-based strategy to prevent hospital-acquired C. difficile infection. Expanding the bundle to include patient hand hygiene is a nurse-driven approach to prevent C. difficile transmission.

  13. Data for evaluation of fast kurtosis strategies, b-value optimization and exploration of diffusion MRI contrast

    NASA Astrophysics Data System (ADS)

    Hansen, Brian; Jespersen, Sune Nørhøj

    2016-08-01

    Here we describe and provide diffusion magnetic resonance imaging (dMRI) data that was acquired in neural tissue and a physical phantom. Data acquired in biological tissue includes: fixed rat brain (acquired at 9.4 T) and spinal cord (acquired at 16.4 T) and in normal human brain (acquired at 3 T). This data was recently used for evaluation of diffusion kurtosis imaging (DKI) contrasts and for comparison to diffusion tensor imaging (DTI) parameter contrast. The data has also been used to optimize b-values for ex vivo and in vivo fast kurtosis imaging. The remaining data was obtained in a physical phantom with three orthogonal fiber orientations (fresh asparagus stems) for exploration of the kurtosis fractional anisotropy. However, the data may have broader interest and, collectively, may form the basis for image contrast exploration and simulations based on a wide range of dMRI analysis strategies.

  14. Data for evaluation of fast kurtosis strategies, b-value optimization and exploration of diffusion MRI contrast

    PubMed Central

    Hansen, Brian; Jespersen, Sune Nørhøj

    2016-01-01

    Here we describe and provide diffusion magnetic resonance imaging (dMRI) data that was acquired in neural tissue and a physical phantom. Data acquired in biological tissue includes: fixed rat brain (acquired at 9.4 T) and spinal cord (acquired at 16.4 T) and in normal human brain (acquired at 3 T). This data was recently used for evaluation of diffusion kurtosis imaging (DKI) contrasts and for comparison to diffusion tensor imaging (DTI) parameter contrast. The data has also been used to optimize b-values for ex vivo and in vivo fast kurtosis imaging. The remaining data was obtained in a physical phantom with three orthogonal fiber orientations (fresh asparagus stems) for exploration of the kurtosis fractional anisotropy. However, the data may have broader interest and, collectively, may form the basis for image contrast exploration and simulations based on a wide range of dMRI analysis strategies. PMID:27576023

  15. Quasispecies spatial models for RNA viruses with different replication modes and infection strategies.

    PubMed

    Sardanyés, Josep; Elena, Santiago F

    2011-01-01

    Empirical observations and theoretical studies suggest that viruses may use different replication strategies to amplify their genomes, which impact the dynamics of mutation accumulation in viral populations and therefore, their fitness and virulence. Similarly, during natural infections, viruses replicate and infect cells that are rarely in suspension but spatially organized. Surprisingly, most quasispecies models of virus replication have ignored these two phenomena. In order to study these two viral characteristics, we have developed stochastic cellular automata models that simulate two different modes of replication (geometric vs stamping machine) for quasispecies replicating and spreading on a two-dimensional space. Furthermore, we explored these two replication models considering epistatic fitness landscapes (antagonistic vs synergistic) and different scenarios for cell-to-cell spread, one with free superinfection and another with superinfection inhibition. We found that the master sequences for populations replicating geometrically and with antagonistic fitness effects vanished at low critical mutation rates. By contrast, the highest critical mutation rate was observed for populations replicating geometrically but with a synergistic fitness landscape. Our simulations also showed that for stamping machine replication and antagonistic epistasis, a combination that appears to be common among plant viruses, populations further increased their robustness by inhibiting superinfection. We have also shown that the mode of replication strongly influenced the linkage between viral loci, which rapidly reached linkage equilibrium at increasing mutations for geometric replication. We also found that the strategy that minimized the time required to spread over the whole space was the stamping machine with antagonistic epistasis among mutations. Finally, our simulations revealed that the multiplicity of infection fluctuated but generically increased along time.

  16. New Biomedical Technologies and Strategies for Prevention of HIV and Other Sexually Transmitted Infections

    PubMed Central

    2016-01-01

    Sexually transmitted infections remain to be of public health concern in many developing countries. Their control is important, considering the high incidence of acute infections, complications and sequelae, and their socioeconomic impact. This article discusses the new biomedical technologies and strategies for the prevention of HIV and other sexually transmitted infections. PMID:27703837

  17. Contrastive Lexical Pragmatics as an Effective Strategy in Teaching Pragmatics: A Review Article

    ERIC Educational Resources Information Center

    Ghaemi, Farid; Ziafar, Meisam

    2011-01-01

    Pragmatic aspect of formulaic language must be emphasized and employed in second language acquisition. Translation of formulaic speech can help learners better understand the pragmatic nature of L2 prefabricated language through comparing them with their L1 (first language) equivalents. This study proposes a contrastive lexical pragmatic approach…

  18. Serological Evidence of Contrasted Exposure to Arboviral Infections between Islands of the Union of Comoros (Indian Ocean)

    PubMed Central

    Dellagi, Koussay; Salez, Nicolas; Maquart, Marianne; Larrieu, Sophie; Yssouf, Amina; Silaï, Rahamatou; Leparc-Goffart, Isabelle; Tortosa, Pablo; de Lamballerie, Xavier

    2016-01-01

    A cross sectional serological survey of arboviral infections in humans was conducted on the three islands of the Union of Comoros, Indian Ocean, in order to test a previously suggested contrasted exposure of the three neighboring islands to arthropod-borne epidemics. Four hundred human sera were collected on Ngazidja (Grande Comore), Mwali (Mohéli) and Ndzouani (Anjouan), and were tested by ELISA for IgM and/or IgG antibodies to Dengue (DENV), Chikungunya (CHIKV), Rift Valley fever (RVFV), West Nile (WNV), Tick borne encephalitis (TBEV) and Yellow fever (YFV) viruses and for neutralizing antibodies to DENV serotypes 1–4. Very few sera were positive for IgM antibodies to the tested viruses indicating that the sero-survey was performed during an inter epidemic phase for the investigated arbovirus infections, except for RVF which showed evidence of recent infections on all three islands. IgG reactivity with at least one arbovirus was observed in almost 85% of tested sera, with seropositivity rates increasing with age, indicative of an intense and long lasting exposure of the Comorian population to arboviral risk. Interestingly, the positivity rates for IgG antibodies to DENV and CHIKV were significantly higher on Ngazidja, confirming the previously suggested prominent exposure of this island to these arboviruses, while serological traces of WNV infection were detected most frequently on Mwali suggesting some transmission specificities associated with this island only. The study provides the first evidence for circulation of RVFV in human populations from the Union of Comoros and further suggests that the virus is currently circulating on the three islands in an inconspicuous manner. This study supports contrasted exposure of the islands of the Comoros archipelago to arboviral infections. The observation is discussed in terms of ecological factors that may affect the abundance and distribution of vector populations on the three islands as well as concurring

  19. [Extravasation of contrast media at the puncture site: Strategies for managment].

    PubMed

    Pacheco Compaña, F J; Gago Vidal, B; Méndez Díaz, C

    2014-01-01

    The incidence of contrast medium extravasation at the venipuncture site has increased with the generalized use of automatic injectors. Most extravasations only cause slight edema and erythema. Nevertheless, in some cases extravasation can result in severe skin lesions or even in compartment syndrome. Lesions caused by extravasation usually resolve spontaneously with conservative treatment. Although the complications of extravasation are well known, institutional protocols are normally lacking and the criteria for taking action and the type of treatment, whether based on the literature or personal preferences, tend to vary. In this article, we review the incidence, risk factors, clinical manifestations, and options for preventing and treating contrast medium extravasation in soft tissues. Finally, we present the protocol we use to manage extravasation at our hospital.

  20. Contrasting reproductive strategies of triploid hybrid males in vertebrate mating systems.

    PubMed

    Pruvost, N B M; Mikulíček, P; Choleva, L; Reyer, H-U

    2015-01-01

    The scarcity of parthenogenetic vertebrates is often attributed to their 'inferior' mode of clonal reproduction, which restricts them to self-reproduce their own genotype lineage and leaves little evolutionary potential with regard to speciation and evolution of sexual reproduction. Here, we show that for some taxa, such uniformity does not hold. Using hybridogenetic water frogs (Pelophylax esculentus) as a model system, we demonstrate that triploid hybrid males from two geographic regions exhibit very different reproductive modes. With an integrative data set combining field studies, crossing experiments, flow cytometry and microsatellite analyses, we found that triploid hybrids from Central Europe are rare, occur in male sex only and form diploid gametes of a single clonal lineage. In contrast, triploid hybrids from north-western Europe are widespread, occur in both sexes and produce recombined haploid gametes. These differences translate into contrasting reproductive roles between regions. In Central Europe, triploid hybrid males sexually parasitize diploid hybrids and just perpetuate their own genotype--which is the usual pattern in parthenogens. In north-western Europe, on the other hand, the triploid males are gamete donors for diploid hybrids, thereby stabilizing the mixed 2n-3n hybrid populations. By demonstrating these contrasting roles in male reproduction, we draw attention to a new significant evolutionary potential for animals with nonsexual reproduction, namely reproductive plasticity.

  1. Scaffold-based Anti-infection Strategies in Bone Repair

    PubMed Central

    Johnson, Christopher T.; García, Andrés J.

    2014-01-01

    Bone fractures and non-union defects often require surgical intervention where biomaterials are used to correct the defect, and approximately 10% of these procedures are compromised by bacterial infection. Currently, treatment options are limited to sustained, high doses of antibiotics and surgical debridement of affected tissue, leaving a significant, unmet need for the development of therapies to combat device-associated biofilm and infections. Engineering implants to prevent infection is a desirable material characteristic. Tissue engineered scaffolds for bone repair provide a means to both regenerate bone and serve as a base for adding antimicrobial agents. Incorporating anti-infection properties into regenerative medicine therapies could improve clinical outcomes and reduce the morbidity and mortality associated with biomaterial implant-associated infections. This review focuses on current animal models and technologies available to assess bone repair in the context of infection, antimicrobial agents to fight infection, the current state of antimicrobial scaffolds, and future directions in the field. PMID:25476163

  2. Contrasting Adult and Infant Immune Responses to HIV Infection and Vaccination

    PubMed Central

    Martinez, David R.; Permar, Sallie R.

    2015-01-01

    Extensive studies have demonstrated that infant immune responses are distinct from those of adults. Despite these differences, infant immunization can elicit protective immune responses at levels comparable to or, in some cases, higher than adult immune responses to many vaccines. To date, only a few HIV vaccine candidates have been tested in infant populations, and none of them evaluated vaccine efficacy. Recent exciting studies showing that HIV-infected infants can develop broad neutralizing antibody responses and that some HIV vaccine regimens can elicit high levels of potentially protective antibodies in infants provide support for the development and testing of HIV vaccines in pediatric populations. In this review, we discuss the differences in adult and infant immune responses in the setting of HIV infection and vaccination. PMID:26656117

  3. Sequential Isotopic Signature Along Gladius Highlights Contrasted Individual Foraging Strategies of Jumbo Squid (Dosidicus gigas)

    PubMed Central

    Lorrain, Anne; Argüelles, Juan; Alegre, Ana; Bertrand, Arnaud; Munaron, Jean-Marie; Richard, Pierre; Cherel, Yves

    2011-01-01

    Background Cephalopods play a major role in marine ecosystems, but knowledge of their feeding ecology is limited. In particular, intra- and inter-individual variations in their use of resources has not been adequatly explored, although there is growing evidence that individual organisms can vary considerably in the way they use their habitats and resources. Methodology/Principal Findings Using δ13C and δ15N values of serially sampled gladius (an archival tissue), we examined high resolution variations in the trophic niche of five large (>60 cm mantle length) jumbo squids (Dosidicus gigas) that were collected off the coast of Peru. We report the first evidence of large inter-individual differences in jumbo squid foraging strategies with no systematic increase of trophic level with size. Overall, gladius δ13C values indicated one or several migrations through the squid's lifetime (∼8–9 months), during which δ15N values also fluctuated (range: 1 to 5‰). One individual showed an unexpected terminal 4.6‰ δ15N decrease (more than one trophic level), thus indicating a shift from higher- to lower-trophic level prey at that time. The data illustrate the high diversity of prey types and foraging histories of this species at the individual level. Conclusions/Significance The isotopic signature of gladii proved to be a powerful tool to depict high resolution and ontogenic variations in individual foraging strategies of squids, thus complementing traditional information offered by stomach content analysis and stable isotopes on metabolically active tissues. The observed differences in life history strategies highlight the high degree of plasticity of the jumbo squid and its high potential to adapt to environmental changes. PMID:21779391

  4. A comparison of stable caesium uptake by six grass species of contrasting growth strategy.

    PubMed

    Willey, N J; Martin, M H

    1997-01-01

    Six plant species in the family Gramineae were used to investigate the relationship between Cs uptake, nutrient regime and plant growth strategy sensu Grime (1979: Plant Growth Strategies and Vegetation Processes, John Wiley). The roots of 66 day old Elymus repens (L.) Gould., Bromus sterilis L., Agrostis stolonifera L., Anthoxanthum odoratum L., Festuca ovina L. and Nardus stricta L. plants grown in acid-washed sand at high and low nutrient levels were exposed to a 96 h pulse of stable Cs at 0.05 mM, 0.15 mM, 0.3 mM, 1.0 mM and 3.0 mM concentrations. Different nutrient regimes induced large differences in dry wt in E. repens, B. sterilis and A. stolonifera plants but only small differences in N. stricta and F. ovina plants. At high nutrient concentrations, A. stolonifera, A. odoratum, F. ovina and N. stricta shoots showed significantly greater increases in internal Cs concentration with rising external Cs concentrations than did E. repens and B. sterilis shoots. The relationship between increases in shoot and external Cs concentrations was statistically indistinguishable between species in plants grown at the low nutrient concentration. These patterns of Cs uptake ensured that with long-term high K concentrations the more competitive plants (E. repens and B. sterilis) accumulated higher concentrations of Cs from low external concentrations than did non-competitive plants or competitive plants grown at low nutrient levels. It is suggested that the relationship between plant growth strategy sensu Grime (1979) and Cs accumulation patterns may help to explain the different concentrations to which species accumulate radiocaesium from the soil.

  5. Automated Analysis and Classification of Infected Macrophages Using Bright-Field Amplitude Contrast Data

    DTIC Science & Technology

    2012-08-01

    foreground pixels  in  the  binary   image are  assigned a corresponding  marker  label.    In  spite  of  all  the  efforts  to  avoid multiple  markers ...25 Figure 6. (A) Original Image (B) Pre-Processed Image (C) Binary Mask by Minimum Error...GFP) integrated onto the chromosome under the control of a constitutive promoter, at a multiplicity of infection (MOI, bacteria/ cell) of 100

  6. Complementary strategies for developing Gd-free high-field T₁ MRI contrast agents based on Mn(III) porphyrins.

    PubMed

    Cheng, Weiran; Haedicke, Inga E; Nofiele, Joris; Martinez, Francisco; Beera, Kiran; Scholl, Timothy J; Cheng, Hai-Ling Margaret; Zhang, Xiao-An

    2014-01-23

    Mn(III) porphyrin (MnP) holds the promise of addressing the emerging challenges associated with Gd-based clinical MRI contrast agents (CAs), namely, Gd-related adverse effect and decreasing sensitivity at high clinical magnetic fields. Two complementary strategies for developing new MnPs as Gd-free CAs with optimized biocompatibility were established to improve relaxivity or clearance rate. MnPs with distinct and tunable pharmacokinetic properties can consequently be constructed for different in vivo applications at clinical field of 3 T.

  7. Contrasting regulation of macrophage iron homeostasis in response to infection with Listeria monocytogenes depending on localization of bacteria.

    PubMed

    Haschka, David; Nairz, Manfred; Demetz, Egon; Wienerroither, Sebastian; Decker, Thomas; Weiss, Günter

    2015-06-01

    Due to its multiple roles for the proliferation and pathogenicity of many microbes on the one hand and via modulation of immune effector functions on the other hand the control over iron homeostasis is thought to play a decisive role in the course of infections. Diversion of cellular iron traffic is considered as an important defense mechanism of macrophages to reduce metal availability for intracellular bacteria residing in the phagosome. However, evidence is lacking whether such alterations of iron homeostasis also become evident upon infection with bacteria gaining access to the cytosol like Listeria monocytogenes. Here we show that infection of macrophages with L. monocytogenes triggers the expression of the major cellular iron exporter ferroportin1 and induces cellular iron egress. As the growth of Listeria within macrophages is promoted by iron, stimulation of ferroportin1 functionality limits the availability of the metal for Listeria residing in the cytoplasm, whereas ferroportin1 degradation upon hepcidin treatment increases intracellular bacterial growth. In parallel to an increase of ferroportin1 expression, infected macrophages induce anti-microbial immune effector mechanisms such as TNFα formation or NO expression which are aggravated upon iron deficiency. These adaptive changes of iron homeostasis and immune response pathways are only found in macrophages infected with Listeria which express listeriolysin O and are therefore able to escape from the phagosome to the cytoplasm. Listeriolysin O deficient Listeria which are restricted to the phagosome are even killed by excess iron which may be based on "iron intoxification" via macrophage radical formation, because iron supplementation in that setting is paralleled by increased ROS formation. Our results indicate that ferroportin1 mediated iron export is a nutritional immune effector pathway to control infection with Listeria residing in the cytoplasm, whereas a different strategy is observed in mutant

  8. Contrasting drought survival strategies of sympatric willows (genus: Salix): consequences for coexistence and habitat specialization.

    PubMed

    Savage, Jessica A; Cavender-Bares, Jeannine M

    2011-06-01

    Many willow species (genus: Salix) co-occur within habitats (α-diversity) and across the landscape (β-diversity) throughout North America. This high diversity is challenging to explain because closely related species often share similar functional traits and thus experience heightened competition and shared pest and pathogen susceptibility. To investigate whether traits related to drought survival are important in maintaining diversity, we conducted an experimental dry-down on six willow species in a greenhouse. We compared species' growth rates, stem and leaf hydraulics, leaf function and dieback and examined potential associations between their drought responses and habitat affinities. Habitat affinities were characterized based on species occurrence in randomly established field plots in central Minnesota. Overall, species that occur in drier, more seasonally variable habitats tended to have higher water-use efficiency, and faster growth rates than species from wetter habitats. However, the greatest difference in drought survival strategies was found between two species with similar habitat affinities. We conclude that differences in willow species could be important in both driving habitat differentiation and permitting temporal differentiation in resource utilization within habitats. Therefore, species' water-use strategies could be important in maintaining both α- and β-diversity across the landscape.

  9. Plasticity in N uptake among sympatric species with contrasting nutrient acquisition strategies in a tropical forest.

    PubMed

    Andersen, Kelly M; Mayor, Jordan R; Turner, Benjamin L

    2017-03-06

    Nitrogen (N) availability influences the productivity and distribution of plants in tropical montane forests. Strategies to acquire soil N, such as direct uptake of organic compounds or associations with root symbionts to enhance N acquisition in exchange for carbon (C), may facilitate plant species coexistence and ecosystem N retention. Alternatively, rapid microbial turnover of soil N forms in tropical soils might promote flexible plant N-uptake strategies and mediate species coexistence. We tested whether sympatric plant species with divergent root symbiont associations, and therefore potentially different nutrient acquisition strategies, partition chemical forms of N or show plasticity in N uptake in a tropical pre-montane forest in Panama. We traced the movement of three (15) N forms into soil pools, microbes, and seedlings of eleven species differing in root traits. Seedlings were grown in a split-plot field transplant experiment, with plots receiving equimolar mixtures of ammonium, nitrate, and glycine, with one form isotopically labeled in each block. After 48-hours, more (15) N was recovered in microbes than in plants, while all pools (extractable organic and inorganic N, microbial biomass, and leaves) contained greater amounts of (15) N from nitrate than from ammonium or glycine. Furthermore, (13) C from dual-labeled glycine was not recovered in the leaves of any seedlings, suggesting the studied species do not directly take up organic N or transform organic N prior to translocation to leaves. Nitrogen uptake differed by root symbiont group only for nitrate, with greater (15) N recovery in plants with arbuscular mycorrhizal (AM) associations or proteoid roots compared to orchids. Some root trait groups differed in (15) N recovery among N forms, with greater nitrate uptake than ammonium or glycine by AM-associated and N2 -fixing plants. However, only five of eleven species showed differences in uptake among N forms. Our results indicate flexibility in

  10. Two Hymenophyllaceae species from contrasting natural environments exhibit a homoiochlorophyllous strategy in response to desiccation stress.

    PubMed

    Flores-Bavestrello, Alejandra; Król, Marianna; Ivanov, Alexander G; Hüner, Norman P A; García-Plazaola, José Ignacio; Corcuera, Luis J; Bravo, León A

    2016-02-01

    Hymenophyllaceae is a desiccation tolerant family of Pteridophytes which are poikilohydric epiphytes. Their fronds are composed by a single layer of cells and lack true mesophyll cells and stomata. Although they are associated with humid and shady environments, their vertical distribution varies along the trunk of the host plant with some species inhabiting the drier sides with a higher irradiance. The aim of this work was to compare the structure and function of the photosynthetic apparatus during desiccation and rehydration in two species, Hymenophyllum dentatum and Hymenoglossum cruentum, isolated from a contrasting vertical distribution along the trunk of their hosts. Both species were subjected to desiccation and rehydration kinetics to analyze frond phenotypic plasticity, as well as the structure, composition and function of the photosynthetic apparatus. Minimal differences in photosynthetic pigments were observed upon dehydration. Measurements of ϕPSII (effective quantum yield of PSII), ϕNPQ (quantum yield of the regulated energy dissipation of PSII), ϕNO (quantum yield of non-regulated energy dissipation of PSII), and TL (thermoluminescence) indicate that both species convert a functional photochemical apparatus into a structure which exhibits maximum quenching capacity in the dehydrated state with minimal changes in photosynthetic pigments and polypeptide compositions. This dehydration-induced conversion in the photosynthetic apparatus is completely reversible upon rehydration. We conclude that H. dentatum and H. cruentum are homoiochlorophyllous with respect to desiccation stress and exhibited no correlation between inherent desiccation tolerance and the vertical distribution along the host tree trunk.

  11. Understanding strategies for seed dispersal by wind under contrasting atmospheric conditions

    PubMed Central

    Wright, S. Joseph; Trakhtenbrot, Ana; Bohrer, Gil; Detto, Matteo; Katul, Gabriel G.; Horvitz, Nir; Muller-Landau, Helene C.; Jones, Frank A.; Nathan, Ran

    2008-01-01

    Traits associated with seed dispersal vary tremendously among sympatric wind-dispersed plants. We used two contrasting tropical tree species, seed traps, micrometeorology, and a mechanistic model to evaluate how variation in four key traits affects seed dispersal by wind. The conceptual framework of movement ecology, wherein external factors (wind) interact with internal factors (plant traits) that enable movement and determine when and where movement occurs, fully captures the variable inputs and outputs of wind dispersal models and informs their interpretation. We used model calculations to evaluate the spatial pattern of dispersed seeds for the 16 factorial combinations of four traits. The study species differed dramatically in traits related to the timing of seed release, and a strong species by season interaction affected most aspects of the spatial pattern of dispersed seeds. A rich interplay among plant traits and seasonal differences in atmospheric conditions caused this interaction. Several of the same plant traits are crucial for both seed dispersal and other aspects of life history variation. Observed traits that limit dispersal are likely to be constrained by their life history consequences. PMID:19060189

  12. Ubiquitination as an Efficient Molecular Strategy Employed in Salmonella Infection

    PubMed Central

    Narayanan, Lakshmi A.; Edelmann, Mariola J.

    2014-01-01

    The ubiquitin modification has various functions in the host innate immune system in response to the bacterial infection. To counteract the host immunity, Salmonella can specifically target ubiquitin pathways by its effector proteins. In this review, we describe the multiple facets of ubiquitin function during infection with Salmonella enterica Typhimurium and hypothesize how these studies on the host–pathogen interactions can help to understand the general function of the ubiquitination pathway in the host cell. PMID:25505465

  13. Ubiquitination as an efficient molecular strategy employed in salmonella infection.

    PubMed

    Narayanan, Lakshmi A; Edelmann, Mariola J

    2014-01-01

    The ubiquitin modification has various functions in the host innate immune system in response to the bacterial infection. To counteract the host immunity, Salmonella can specifically target ubiquitin pathways by its effector proteins. In this review, we describe the multiple facets of ubiquitin function during infection with Salmonella enterica Typhimurium and hypothesize how these studies on the host-pathogen interactions can help to understand the general function of the ubiquitination pathway in the host cell.

  14. Different leaf cost–benefit strategies of ferns distributed in contrasting light habitats of sub-tropical forests

    PubMed Central

    Zhu, Shi-Dan; Li, Rong-Hua; Song, Juan; He, Peng-Cheng; Liu, Hui; Berninger, Frank; Ye, Qing

    2016-01-01

    Background and Aims Ferns are abundant in sub-tropical forests in southern China, with some species being restricted to shaded understorey of natural forests, while others are widespread in disturbed, open habitats. To explain this distribution pattern, we hypothesize that ferns that occur in disturbed forests (FDF) have a different leaf cost–benefit strategy compared with ferns that occur in natural forests (FNF), with a quicker return on carbon investment in disturbed habitats compared with old-growth forests. Methods We chose 16 fern species from contrasting light habitats (eight FDF and eight FNF) and studied leaf functional traits, including leaf life span (LLS), specific leaf area (SLA), leaf nitrogen and phosphorus concentrations (N and P), maximum net photosynthetic rates (A), leaf construction cost (CC) and payback time (PBT), to conduct a leaf cost–benefit analysis for the two fern groups. Key Results The two groups, FDF and FNF, did not differ significantly in SLA, leaf N and P, and CC, but FDF had significantly higher A, greater photosynthetic nitrogen- and phosphorus-use efficiencies (PNUE and PPUE), and shorter PBT and LLS compared with FNF. Further, across the 16 fern species, LLS was significantly correlated with A, PNUE, PPUE and PBT, but not with SLA and CC. Conclusions Our results demonstrate that leaf cost–benefit analysis contributes to understanding the distribution pattern of ferns in contrasting light habitats of sub-tropical forests: FDF employing a quick-return strategy can pre-empt resources and rapidly grow in the high-resource environment of open habitats; while a slow-return strategy in FNF allows their persistence in the shaded understorey of old-growth forests. PMID:26684751

  15. Root transcriptional responses of two melon genotypes with contrasting resistance to Monosporascus cannonballus (Pollack et Uecker) infection

    PubMed Central

    2012-01-01

    Background Monosporascus cannonballus is the main causal agent of melon vine decline disease. Several studies have been carried out mainly focused on the study of the penetration of this pathogen into melon roots, the evaluation of symptoms severity on infected roots, and screening assays for breeding programs. However, a detailed molecular view on the early interaction between M. cannonballus and melon roots in either susceptible or resistant genotypes is lacking. In the present study, we used a melon oligo-based microarray to investigate the gene expression responses of two melon genotypes, Cucumis melo ‘Piel de sapo’ (‘PS’) and C. melo ‘Pat 81’, with contrasting resistance to the disease. This study was carried out at 1 and 3 days after infection (DPI) by M. cannonballus. Results Our results indicate a dissimilar behavior of the susceptible vs. the resistant genotypes from 1 to 3 DPI. ‘PS’ responded with a more rapid infection response than ‘Pat 81’ at 1 DPI. At 3 DPI the total number of differentially expressed genes identified in ‘PS’ declined from 451 to 359, while the total number of differentially expressed transcripts in ‘Pat 81’ increased from 187 to 849. Several deregulated transcripts coded for components of Ca2+ and jasmonic acid (JA) signalling pathways, as well as for other proteins related to defence mechanisms. Transcriptional differences in the activation of the JA-mediated response in ‘Pat 81’ compared to ‘PS’ suggested that JA response might be partially responsible for their observed differences in resistance. Conclusions As a result of this study we have identified for the first time a set of candidate genes involved in the root response to the infection of the pathogen causing melon vine decline. This information is useful for understanding the disease progression and resistance mechanisms few days after inoculation. PMID:23134692

  16. Serological response to Helicobacter pylori infection among Latin American populations with contrasting risks of gastric cancer

    PubMed Central

    Camargo, M. Constanza; Beltran, Mauricio; Conde-Glez, Carlos; Harris, Paul R.; Michel, Angelika; Waterboer, Tim; Flórez, Astrid Carolina; Torres, Javier; Ferreccio, Catterina; Sampson, Joshua N.; Pawlita, Michael; Rabkin, Charles S.

    2015-01-01

    Gastric cancer is a rare outcome of chronic Helicobacter pylori infection. Serologic profiles may reveal bacterial, environmental and/or host factors associated with cancer risk. We therefore compared specific anti-H. pylori antibodies among populations with at least 2-fold differences in gastric cancer mortality from Mexico, Colombia and Chile. Our study included 1,776 adults (mean age 42 years) from three nationally representative surveys, equally divided between residents of high- and low-risk areas. Antibodies to 15 immunogenic H. pylori antigens were measured by fluorescent bead-based multiplex assays; results were summarized to identify overall H. pylori seropositivity. We used logistic regression to model associations between antibody seroreactivity and regional cancer risk (high vs. low), adjusting for country, age and sex. Both risk areas had similar H. pylori seroprevalence. Residents in high- and low-risk areas were seroreactive to a similar number of antigens (means 8.2 vs. 7.9, respectively; adjusted-odds ratio, OR: 1.02, p=0.05). Seroreactivities to Catalase and the known virulence proteins CagA and VacA were each significantly (p<0.05) associated with residence in high-risk areas, but ORs were moderate (1.26, 1.42, and 1.41, respectively) and their discriminatory power was low (ROC area under curve <0.6). The association of Catalase was independent from effects of either CagA or VacA. Sensitivity analyses for antibody associations restricted to H. pylori-seropositive individuals generally replicated significant associations. Our findings suggest that humoral responses to H. pylori are insufficient to distinguish high and low gastric cancer risk in Latin America. Factors determining population variation of gastric cancer burden remain to be identified. PMID:26178251

  17. Combined off-resonance imaging and T2 relaxation in the rotating frame for positive contrast MR imaging of infection in a murine burn model

    PubMed Central

    Andronesi, Ovidiu C.; Mintzopoulos, Dionyssios; Righi, Valeria; Psychogios, Nikolaos; Kesarwani, Meenu; He, Jianxin; Yasuhara, Shingo; Dai, George; Rahme, Laurence G.; Tzika, Aria A.

    2010-01-01

    Purpose To develop novel magnetic resonance (MR) imaging methods to monitor accumulation of macrophages in inflammation and infection. Positive-contrast MR imaging provides an alternative to negative-contrast MRI, exploiting the chemical shift induced by ultra-small superparamagnetic iron-oxide (USPIO) nanoparticles to nearby water molecules. We introduce a novel combination of off-resonance (ORI) positive-contrast MRI and T2ρ relaxation in the rotating frame (ORI-T2ρ) for positive-contrast MR imaging of USPIO. Materials and Methods We tested ORI-T2ρ in phantoms and imaged in vivo the accumulation of USPIO-labeled macrophages at the infection site in a mouse model of burn trauma and infection with Pseudomonas aeruginosa (PA). PA infection is clinically important. The USPIO nanoparticles were injected directly in the animals in solution, and macrophage labeling occurred in vivo in the animal model. Results We observed a significant difference between ORI-T2ρ and ORI, which leads us to suggest that ORI-T2ρ is more sensitive in detecting USPIO signal. To this end, the ORI-T2ρ positive contrast method may prove to be of higher utility in future research. Conclusion Our results may have direct implications in the longitudinal monitoring of infection, and open perspectives for testing novel anti-infective compounds. PMID:21031524

  18. Spontaneous Strategy Use Protects Against Visual Working Memory Deficits in Older Adults Infected with HIV

    PubMed Central

    Woods, Steven Paul; Weber, Erica; Cameron, Marizela V.; Dawson, Matthew S.; Delano-Wood, Lisa; Bondi, Mark W.; Grant, Igor

    2010-01-01

    Recent studies suggest that older human immunodeficiency virus (HIV)-infected adults are at particular risk for HIV-associated neurocognitive disorders (HAND), including dementia. Deficits in attention/working memory are posited to play a central role in the development of HAND among older adults. The aim of the present study was to examine the possible protective benefits of spontaneous strategy use during a visual working memory task in 46 older and 42 younger adults infected with HIV. Results revealed a significant interaction between age and strategy use, with older adults who used a meta-cognitive strategy demonstrating superior working memory performance versus non-strategy users. This effect was not observed in the younger HIV-infected sample and was not better explained by possible confounding factors, such as education, comorbid medical conditions, or HIV disease severity. Within the older group, strategy use was associated with better executive functions and higher estimated verbal intelligence. Findings from this study suggest that working memory declines in older HIV-infected adults are moderated by the use of higher-level mnemonic strategies and may inform cognitive neurorehabilitation efforts to improve cognitive and everyday functioning outcomes in older persons living with HIV infection. PMID:20876195

  19. Spontaneous strategy use protects against visual working memory deficits in older adults infected with HIV.

    PubMed

    Woods, Steven Paul; Weber, Erica; Cameron, Marizela V; Dawson, Matthew S; Delano-Wood, Lisa; Bondi, Mark W; Grant, Igor

    2010-12-01

    Recent studies suggest that older human immunodeficiency virus (HIV)-infected adults are at particular risk for HIV-associated neurocognitive disorders (HAND), including dementia. Deficits in attention/working memory are posited to play a central role in the development of HAND among older adults. The aim of the present study was to examine the possible protective benefits of spontaneous strategy use during a visual working memory task in 46 older and 42 younger adults infected with HIV. Results revealed a significant interaction between age and strategy use, with older adults who used a meta-cognitive strategy demonstrating superior working memory performance versus non-strategy users. This effect was not observed in the younger HIV-infected sample and was not better explained by possible confounding factors, such as education, comorbid medical conditions, or HIV disease severity. Within the older group, strategy use was associated with better executive functions and higher estimated verbal intelligence. Findings from this study suggest that working memory declines in older HIV-infected adults are moderated by the use of higher-level mnemonic strategies and may inform cognitive neurorehabilitation efforts to improve cognitive and everyday functioning outcomes in older persons living with HIV infection.

  20. Clinical Appearance of Oral Candida Infection and Therapeutic Strategies

    PubMed Central

    Patil, Shankargouda; Rao, Roopa S.; Majumdar, Barnali; Anil, Sukumaran

    2015-01-01

    Candida species present both as commensals and opportunistic pathogens of the oral cavity. For decades, it has enthralled the clinicians to investigate its pathogenicity and to improvise newer therapeutic regimens based on the updated molecular research. Candida is readily isolated from the oral cavity, but simple carriage does not predictably result in development of an infection. Whether it remains as a commensal, or transmutes into a pathogen, is usually determined by pre-existing or associated variations in the host immune system. The candida infections may range from non-life threatening superficial mucocutaneous disorders to invasive disseminated disease involving multiple organs. In fact, with the increase in number of AIDS cases, there is a resurgence of less common forms of oral candida infections. The treatment after confirmation of the diagnosis should include recognizing and eliminating the underlying causes such as ill-fitting oral appliances, history of medications (antibiotics, corticosteroids, etc.), immunological and endocrine disorders, nutritional deficiency states and prolonged hospitalization. Treatment with appropriate topical antifungal agents such as amphotericin, nystatin, or miconazole usually resolves the symptoms of superficial infection. Occasionally, administration of systemic antifungal agents may be necessary in immunocompromised patients, the selection of which should be based upon history of recent azole exposure, a history of intolerance to an antifungal agent, the dominant Candida species and current susceptibility data. PMID:26733948

  1. Strategies for the prevention of periprosthetic joint infection.

    PubMed

    Adeli, B; Parvizi, J

    2012-11-01

    Periprosthetic joint infection (PJI) is a devastating complication which can follow a total joint arthroplasty (TJA). Although rare, this ongoing threat undermines the success of TJA, a historically reputable procedure. It has haunted the orthopedic community for decades and several ongoing studies have provided insights and new approaches to effectively battle this multilayered problem.

  2. Ubiquitination as an efficient molecular strategy employed in salmonella infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ubiquitin modification has various functions in the host innate immune system in response to the bacterial infection. To counteract the host immunity, Salmonella can specifically target ubiquitin pathways by its effector proteins. In this review, we describe the multiple facets of ubiquitin func...

  3. Potential strategies for the eradication of multidrug-resistant Gram-negative bacterial infections.

    PubMed

    Huwaitat, Rawan; McCloskey, Alice P; Gilmore, Brendan F; Laverty, Garry

    2016-07-01

    Antimicrobial resistance is one of the leading threats to society. The increasing burden of multidrug-resistant Gram-negative infection is particularly concerning as such bacteria are demonstrating resistance to nearly all currently licensed therapies. Various strategies have been hypothesized to treat multidrug-resistant Gram-negative infections including: targeting the Gram-negative outer membrane; neutralization of lipopolysaccharide; inhibition of bacterial efflux pumps and prevention of protein folding. Silver and silver nanoparticles, fusogenic liposomes and nanotubes are potential strategies for extending the activity of licensed, Gram-positive selective, antibiotics to Gram-negatives. This may serve as a strategy to fill the current void in pharmaceutical development in the short term. This review outlines the most promising strategies that could be implemented to solve the threat of multidrug-resistant Gram-negative infections.

  4. Estimating updraft velocity components over large spatial scales: contrasting migration strategies of golden eagles and turkey vultures.

    PubMed

    Bohrer, Gil; Brandes, David; Mandel, James T; Bildstein, Keith L; Miller, Tricia A; Lanzone, Michael; Katzner, Todd; Maisonneuve, Charles; Tremblay, Junior A

    2012-02-01

    Soaring birds migrate in massive numbers worldwide. These migrations are complex and dynamic phenomena, strongly influenced by meteorological conditions that produce thermal and orographic uplift as the birds traverse the landscape. Herein we report on how methods were developed to estimate the strength of thermal and orographic uplift using publicly available digital weather and topography datasets at continental scale. We apply these methods to contrast flight strategies of two morphologically similar but behaviourally different species: golden eagle, Aquila chrysaetos, and turkey vulture, Cathartes aura, during autumn migration across eastern North America tracked using GPS tags. We show that turkey vultures nearly exclusively used thermal lift, whereas golden eagles primarily use orographic lift during migration. It has not been shown previously that migration tracks are affected by species-specific specialisation to a particular uplift mode. The methods introduced herein to estimate uplift components and test for differences in weather use can be applied to study movement of any soaring species.

  5. Strategies for fast and low-dose laboratory-based phase contrast tomography for microstructural scaffold analysis in tissue engineering

    NASA Astrophysics Data System (ADS)

    Hagen, Charlotte K.; Maghsoudlou, Panagiotis; Totonelli, Giorgia; Diemoz, Paul C.; Endrizzi, Marco; Zamir, Anna; Coan, Paola; Bravin, Alberto; De Coppi, Paolo; Olivo, Alessandro

    2016-10-01

    The application of x-ray phase contrast computed tomography (PCT) to the field of tissue engineering is dis- cussed. Specific focus is on the edge illumination PCT method, which can be adapted to weakly coherent x-ray sources, permitting PCT imaging in standard (non-synchrotron) laboratory environments. The method was applied to a prominent research topic in tissue engineering, namely the development of effective and reliable decellularization protocols to derive scaffolds from native tissue. Results show that edge illumination PCT provides sufficient image quality to evaluate the microstructural integrity of scaffolds and, thus, to assess the performance of the used decellularization technique. In order to highlight that edge illumination PCT can ultimately comply with demands on a high specimen throughput and low doses of radiation, recently developed strategies for scan time and dose reduction are discussed.

  6. Genomic innovations linked to infection strategies across emerging pathogenic chytrid fungi.

    PubMed

    Farrer, Rhys A; Martel, An; Verbrugghe, Elin; Abouelleil, Amr; Ducatelle, Richard; Longcore, Joyce E; James, Timothy Y; Pasmans, Frank; Fisher, Matthew C; Cuomo, Christina A

    2017-03-21

    To understand the evolutionary pathways that lead to emerging infections of vertebrates, here we explore the genomic innovations that allow free-living chytrid fungi to adapt to and colonize amphibian hosts. Sequencing and comparing the genomes of two pathogenic species of Batrachochytrium to those of close saprophytic relatives reveals that pathogenicity is associated with remarkable expansions of protease and cell wall gene families, while divergent infection strategies are linked to radiations of lineage-specific gene families. By comparing the host-pathogen response to infection for both pathogens, we illuminate the traits that underpin a strikingly different immune response within a shared host species. Our results show that, despite commonalities that promote infection, specific gene-family radiations contribute to distinct infection strategies. The breadth and evolutionary novelty of candidate virulence factors that we discover underscores the urgent need to halt the advance of pathogenic chytrids and prevent incipient loss of biodiversity.

  7. Beyond early infant diagnosis: case finding strategies for identification of HIV-infected infants and children

    PubMed Central

    Ahmed, Saeed; Kim, Maria H.; Sugandhi, Nandita; Phelps, B. Ryan; Sabelli, Rachael; Diallo, Mamadou O.; Young, Paul; Duncan, Dana; Kellerman, Scott E.

    2014-01-01

    There are 3.4 million children infected with HIV worldwide, with up to 2.6 million eligible for treatment under current guidelines. However, roughly 70% of infected children are not receiving live-saving HIV care and treatment. Strengthening case finding through improved diagnosis strategies, and actively linking identified HIV-infected children to care and treatment is essential to ensuring that these children benefit from the care and treatment available to them. Without attention or advocacy, the majority of these children will remain undiagnosed and die from complications of HIV. In this article, we summarize the challenges of identifying HIV-infected infants and children, review currently available evidence and guidance, describe promising new strategies for case finding, and make recommendations for future research and interventions to improve identification of HIV-infected infants and children. PMID:24361633

  8. Genomic innovations linked to infection strategies across emerging pathogenic chytrid fungi

    PubMed Central

    Farrer, Rhys A.; Martel, An; Verbrugghe, Elin; Abouelleil, Amr; Ducatelle, Richard; Longcore, Joyce E.; James, Timothy Y.; Pasmans, Frank; Fisher, Matthew C.; Cuomo, Christina A.

    2017-01-01

    To understand the evolutionary pathways that lead to emerging infections of vertebrates, here we explore the genomic innovations that allow free-living chytrid fungi to adapt to and colonize amphibian hosts. Sequencing and comparing the genomes of two pathogenic species of Batrachochytrium to those of close saprophytic relatives reveals that pathogenicity is associated with remarkable expansions of protease and cell wall gene families, while divergent infection strategies are linked to radiations of lineage-specific gene families. By comparing the host–pathogen response to infection for both pathogens, we illuminate the traits that underpin a strikingly different immune response within a shared host species. Our results show that, despite commonalities that promote infection, specific gene-family radiations contribute to distinct infection strategies. The breadth and evolutionary novelty of candidate virulence factors that we discover underscores the urgent need to halt the advance of pathogenic chytrids and prevent incipient loss of biodiversity. PMID:28322291

  9. Contrasting micro/nano architecture on termite wings: two divergent strategies for optimising success of colonisation flights.

    PubMed

    Watson, Gregory S; Cribb, Bronwen W; Watson, Jolanta A

    2011-01-01

    Many termite species typically fly during or shortly after rain periods. Local precipitation will ensure water will be present when establishing a new colony after the initial flight. Here we show how different species of termite utilise two distinct and contrasting strategies for optimising the success of the colonisation flight. Nasutitermes sp. and Microcerotermes sp. fly during rain periods and adopt hydrophobic structuring/'technologies' on their wings to contend with a moving canvas of droplets in daylight hours. Schedorhinotermes sp. fly after rain periods (typically at night) and thus do not come into contact with mobile droplets. These termites, in contrast, display hydrophilic structuring on their wings with a small scale roughness which is not dimensionally sufficient to introduce an increase in hydrophobicity. The lack of hydrophobicity allows the termite to be hydrophilicly captured at locations where water may be present in large quantities; sufficient for the initial colonization period. The high wettability of the termite cuticle (Schedorhinotermes sp.) indicates that the membrane has a high surface energy and thus will also have strong attractions with solid particles. To investigate this the termite wings were also interacted with both artificial and natural contaminants in the form of hydrophilic silicon beads of various sizes, 4 µm C(18) beads and three differently structured pollens. These were compared to the superhydrophobic surface of the planthopper (Desudaba psittacus) and a native Si wafer surface. The termite cuticle demonstrated higher adhesive interactions with all particles in comparison to those measured on the plant hopper.

  10. Looking into Candida albicans infection, host response, and antifungal strategies

    PubMed Central

    Wang, Yan

    2015-01-01

    Candida albicans, a commonly encountered fungal pathogen, causes diseases varying from superficial mucosal complaints to life-threatening systemic disorders. Among the virulence traits of C. albicans, yeast-to-hypha transition is most widely acknowledged. Host innate immunity to C. albicans critically requires pattern recognition receptors (PRRs), and defence against C. albicans infection is provided by an exquisite interplay between the innate and adaptive arms of the host immune system. PMID:25590793

  11. Looking into Candida albicans infection, host response, and antifungal strategies.

    PubMed

    Wang, Yan

    2015-01-01

    Candida albicans, a commonly encountered fungal pathogen, causes diseases varying from superficial mucosal complaints to life-threatening systemic disorders. Among the virulence traits of C. albicans, yeast-to-hypha transition is most widely acknowledged. Host innate immunity to C. albicans critically requires pattern recognition receptors (PRRs), and defence against C. albicans infection is provided by an exquisite interplay between the innate and adaptive arms of the host immune system.

  12. Drought responses of two gymnosperm species with contrasting stomatal regulation strategies under elevated [CO2] and temperature.

    PubMed

    Duan, Honglang; O'Grady, Anthony P; Duursma, Remko A; Choat, Brendan; Huang, Guomin; Smith, Renee A; Jiang, Yanan; Tissue, David T

    2015-07-01

    Future climate regimes characterized by rising [CO2], rising temperatures and associated droughts may differentially affect tree growth and physiology. However, the interactive effects of these three factors are complex because elevated [CO2] and elevated temperature may generate differential physiological responses during drought. To date, the interactive effects of elevated [CO2] and elevated temperature on drought-induced tree mortality remain poorly understood in gymnosperm species that differ in stomatal regulation strategies. Water relations and carbon dynamics were examined in two species with contrasting stomatal regulation strategies: Pinus radiata D. Don (relatively isohydric gymnosperm; regulating stomata to maintain leaf water potential above critical thresholds) and Callitris rhomboidea R. Br (relatively anisohydric gymnosperm; allowing leaf water potential to decline as the soil dries), to assess response to drought as a function of [CO2] and temperature. Both species were grown in two [CO2] (C(a) (ambient, 400 μl l(-1)) and C(e) (elevated, 640 μl l(-1))) and two temperature (T(a) (ambient) and T(e) (ambient +4 °C)) treatments in a sun-lit glasshouse under well-watered conditions. Drought plants were then exposed to a progressive drought until mortality. Prior to mortality, extensive xylem cavitation occurred in both species, but significant depletion of non-structural carbohydrates was not observed in either species. Te resulted in faster mortality in P. radiata, but it did not modify the time-to-mortality in C. rhomboidea. C(e) did not delay the time-to-mortality in either species under drought or T(e) treatments. In summary, elevated temperature (+4 °C) had greater influence than elevated [CO2] (+240 μl l(-1)) on drought responses of the two studied gymnosperm species, while stomatal regulation strategies did not generally affect the relative contributions of hydraulic failure and carbohydrate depletion to mortality under severe drought.

  13. Strategy for the treatment of Helicobacter pylori infection.

    PubMed

    Shiota, Seiji; Yamaoka, Yoshio

    2014-01-01

    The eradication of Helicobacter pylori not only heals peptic ulcers but also prevents their recurrence and reduces the risk of development of gastric cancer and other H. pylori-associated disorders. H. pylori eradication heals gastritis and may prevent the spread of infection, reducing the future costs required for the treatment of subsequent H. pylori-associated diseases. There are various guidelines for the management of H. pylori infection worldwide, such as the guidelines of the American College of Gastroenterology, Maastricht IV, the Second Asia-Pacific Consensus Conference, and Japan. The Japanese health insurance system approved H. pylori eradication therapy for H. pylori-related chronic gastritis in 2013. Triple therapy regimens comprising 1 proton pump inhibitor and 2 antimicrobial agents such as amoxicillin, clarithromycin, metronidazole, levofloxacin, or tetracycline have been widely used to eradicate this bacterium. The rate of successful eradication has declined owing to the increased rate of drug resistance stemming from the wide usage of antibiotics. This issue is of particular relevance with regard to clarithromycin. In worldwide, clarithromycin-based triple therapy should be abandoned, as it is no longer effective. Quadruple therapy and sequential therapy are reasonable alternatives for initial therapy. First-line treatment should be recommended on the basis of an understanding of the local prevalence of H. pylori antimicrobial resistance.

  14. [Microbicides for preventing sexually transmitted infections: Current status and strategies for preclinical evaluation of new candidates].

    PubMed

    Fernández Romero, José A; Gil, Pedro I; Ré, Viviana; Robbiani, Melissa; Paglini, Gabriela

    2014-01-01

    Microbicides are a new tool, still under investigation, which could help prevent infection by the human immunodeficiency virus (HIV) and other sexually transmitted infections (STIs). Increasing evidence shows that the complexity of sexual transmission of viral pathogens requires the identification of compounds able to block the early events during the cycle of viral infection. In this manuscript we provide a comprehensive review of the different microbicide strategies that have been studied or are currently being considered for STI prevention, particularly emphasizing those having the potential to block HIV infection. The manuscript also reviews the complex process that is required to conduct future clinical studies in humans and concludes with a brief discussion of the strategies that could be part of the immediate future in microbicide research.

  15. Real-time PCR strategy for parasite quantification in blood and tissue samples of experimental Trypanosoma cruzi infection.

    PubMed

    Caldas, Sérgio; Caldas, Ivo Santana; Diniz, Lívia de Figueiredo; Lima, Wanderson Geraldo de; Oliveira, Riva de Paula; Cecílio, Alzira Batista; Ribeiro, Isabela; Talvani, André; Bahia, Maria Terezinha

    2012-09-01

    The lack of an accurate diagnosis has been a serious obstacle to the advancement of the anti-Trypanosoma cruzi chemotherapy and long-term infection can result in different health risks to human. PCRs are alternative methods, more sensitive than conventional parasitological techniques, which due to their low sensitivities are considered unsuitable for these purposes. The aim of this study was to investigate a sensitive diagnostic strategy to quantify blood and cardiac tissues parasites based on real-time PCR tools during acute and chronic phases of murine Chagas disease, as well as to monitor the evolution of infection in those mice under specific treatment. In parallel, fresh blood examination, immunological analysis and quantification of cardiac inflammation were also performed to confront and improve real-time PCR data. Similar profiles of parasitemia curves were observed in both quantification techniques during the acute phase of the infection. In contrast, parasites could be quantified only by real-time PCR at 60 and 120 days of infection. In cardiac tissue, real-time PCR detected T. cruzi DNA in 100% of infected mice, and using this tool a significant Pearson correlation between parasite load in peripheral blood and in cardiac tissue during acute and chronic phases was observed. Levels of serum CCL2, CCL5 and nitric oxide were coincident with parasite load but focal and diffuse mononuclear infiltrates was observed, even with significant (p<0.05) reduction of parasitism after 60 days of infection. Later, this methodology was used to monitor the evolution of infection in animals treated with itraconazole (Itz). Itz-treatment induced a reduction of parasite load in both blood and cardiac muscle at the treatment period, but after the end of chemotherapy an increase of parasitism was detected. Interestingly, inflammatory mediators levels and heart inflammation intensity had similar evolution to the parasite load, in the group of animals treated. Taken together, our

  16. A Novel Strategy for Live Detection of Viral Infection in Drosophila melanogaster

    PubMed Central

    Ekström, Jens-Ola; Hultmark, Dan

    2016-01-01

    We have created a transgenic reporter for virus infection, and used it to study Nora virus infection in Drosophila melanogaster. The transgenic construct, Munin, expresses the yeast transcription factor Gal4, tethered to a transmembrane anchor via a linker that can be cleaved by a viral protease. In infected cells, liberated Gal4 will then transcribe any gene that is linked to a promoter with a UAS motif, the target for Gal4 transcription. For instance, infected cells will glow red in the offspring of a cross between the Munin stock and flies with a UAS-RFPnls transgene (expressing a red fluorescent protein). In such flies we show that after natural infection, via the faecal-oral route, 5–15% of the midgut cells are infected, but there is little if any infection elsewhere. By contrast, we can detect infection in many other tissues after injection of virus into the body cavity. The same principle could be applied for other viruses and it could also be used to express or suppress any gene of interest in infected cells. PMID:27189868

  17. Contrasting genetic structure of rear edge and continuous range populations of a parasitic butterfly infected by Wolbachia

    PubMed Central

    2013-01-01

    Background Climatic oscillations are among the long-term factors shaping the molecular features of animals and plants and it is generally supposed that the rear edges (i.e., the low-latitude limits of distribution of any given specialised species) situated closer to glacial refugia are vital long-term stores of genetic diversity. In the present study, we compared the genetic structure of several populations of an endangered and obligate myrmecophilous butterfly (Maculinea arion) from two distinct and geographically distant parts of its European distribution (i.e., Italy and Poland), which fully represent the ecological and morphological variation occurring across the continent. Results We sequenced the COI mitochondrial DNA gene (the ‘barcoding gene’) and the EF-1α nuclear gene and found substantial genetic differentiation among M. arion Italian populations in both markers. Eleven mtDNA haplotypes were present in Italy. In contrast, almost no mtDNA polymorphisms was found in the Polish M. arion populations, where genetic differentiation at the nuclear gene was low to moderate. Interestingly, the within-population diversity levels in the EF-1α gene observed in Italy and in Poland were comparable. The genetic data did not support any subspecies divisions or any ecological specialisations. All of the populations studied were infected with a single strain of Wolbachia and our screening suggested 100% prevalence of the bacterium. Conclusions Differences in the genetic structure of M. arion observed in Italy and in Poland may be explained by the rear edge theory. Although we were not able to pinpoint any specific evolutionarily significant units, we suggest that the Italian peninsula should be considered as a region of special conservation concern and one that is important for maintaining the genetic diversity of M. arion in Europe. The observed pattern of mtDNA differentiation among the populations could not be explained by an endosymbiotic infection. PMID

  18. The role of bacterial biofilm in persistent infections and control strategies

    PubMed Central

    Chen, Li; Wen, Yu-mei

    2011-01-01

    Bacterial biofilms can be viewed as a specific type of persistent bacterial infection. After initial invasion, microbes can attach to living and non-living surfaces, such as prosthetics and indwelling medical devices, and form a biofilm composed of extracellular polysaccharides, proteins, and other components. In hosts, biofilm formation may trigger drug resistance and inflammation, resulting in persistent infections. The clinical aspects of biofilm formation and leading strategies for biofilm inhibitors will be discussed in this mini-review. PMID:21485310

  19. Global strategies are required to cure and eliminate HBV infection.

    PubMed

    Revill, Peter; Testoni, Barbara; Locarnini, Stephen; Zoulim, Fabien

    2016-04-01

    Chronic HBV infection results in >1 million deaths per year from cirrhosis and liver cancer. No known cure for chronic HBV exists, due in part to the continued presence of transcriptionally active DNA in the nucleus that is not directly targeted by current antiviral therapies. A coordinated approach is urgently needed to advance an HBV cure worldwide, such as those established in the HIV field. We propose the establishment of an International Coalition to Eliminate Hepatitis B Virus (ICE-HBV) to facilitate the formation of international working groups on HBV virology, immunology, innovative tools and clinical trials: to promote awareness and education as well as to drive changes in government policy and ensure funds are channelled to HBV cure research and drug development. With the ICE-HBV in place, it should be possible to enable a HBV cure within the next decade.

  20. Negotiating hospital infections: The debate between ecological balance and eradication strategies in British hospitals, 1947-1969

    PubMed Central

    Condrau, Flurin; Kirk, Robert G. W.

    2012-01-01

    This paper reviews and contrasts two strategies of infection control that emerged in response to the growing use of antibiotics within British hospitals, c.1946-1969. At this time, we argue, the hospital became an arena within which representatives of the medical sciences and clinical practices contested not so much the content of knowledge but the way that knowledge translated into practice. Key to our story are the conceptual assumptions about antibiotics put forward by clinicians, on the one hand, and microbiologists on the other. The former embraced antibiotics as the latest weapon in their fight to eradicate disease. For clinicians, the use of antibiotics were utilised within a conceptual frame that prioritised the value of the individual patient before them. Microbiologists, in contrast, understood antibiotics quite differently. They adopted a complex understanding of the way antibiotics functioned within the hospital environment that emphasised the relational and ecological aspects of their use. Despite their broader environmental focus, microbiologists focus on the ways in which bacteria travelled led to ever greater emphasis to be placed on the «healthy» body which, having been exposed to antibiotics, became a dangerous carrier of resistant staphylococcal strains. The surrounding debate regarding the appropriate use of antibiotics reveals the complex relationship between hospital, the medical sciences and clinical practice. We conclude that the history of hospital infections invites a more fundamental reflection on global hospital cultures, antibiotic prescription practices, and the fostering of an interdisciplinary spirit among the professional groups living and working in the hospital. PMID:22332465

  1. [Social marketing: applying commercial strategies to the prevention of nosocomial infections].

    PubMed

    Sax, Hugo; Longtin, Yves; Alvarez-Ceyssat, Raymonde; Bonfillon, Chantal; Cavallero, Sabrina; Dayer, Pierre; Ginet, Claude; Herrault, Pascale

    2009-04-01

    Although a large proportion of healthcare-associated infections are avoidable, healthcare workers do not always practice evidence-based preventive strategies. Marketing technologies might help to improve patient safety. This article presents the basic principles of marketing and its potential use to promote good infection control practices. The marketing mix (Product, Price, Place, and Promotion) should be taken into account to induce behaviour change. By placing the emphasis on the perceived "profits" for healthcare workers the approach might lose its moral aspect and gain in effectiveness. VigiGerme, a non-commercial registered trademark, applies social marketing techniques to infection control and prevention.

  2. Novel Strategies in the Prevention and Treatment of Urinary Tract Infections

    PubMed Central

    Lüthje, Petra; Brauner, Annelie

    2016-01-01

    Urinary tract infections are one of the most common bacterial infections, especially in women and children, frequently treated with antibiotics. The alarming increase in antibiotic resistance is a global threat to future treatment of infections. Therefore, alternative strategies are urgently needed. The innate immune system plays a fundamental role in protecting the urinary tract from infections. Antimicrobial peptides form an important part of the innate immunity. They are produced by epithelial cells and neutrophils and defend the urinary tract against invading bacteria. Since efficient resistance mechanisms have not evolved among bacterial pathogens, much effort has been put into exploring the role of antimicrobial peptides and possibilities to utilize them in clinical practice. Here, we describe the impact of antimicrobial peptides in the urinary tract and ways to enhance the production by hormones like vitamin D and estrogen. We also discuss the potential of medicinal herbs to be used in the prophylaxis and the treatment of urinary tract infections. PMID:26828523

  3. New insight on antimicrobial therapy adjustment strategies for gram-negative bacterial infection

    PubMed Central

    Du, Wei; Chen, Hong; Xiao, Shuzhen; Tang, Wei; Shi, Guochao

    2017-01-01

    Abstract Gram-negative bacterial infections, especially multidrug-resistant (MDR) bacterial infection, are becoming a serious threat to public health. Although it is widely accepted that both appropriate initial empirical therapy and targeted therapy are important, but for patients needing therapy adjustment, few studies have explored whether adjustment strategy based on microbiologic susceptibility test (MST) brings better outcome compared with empirical adjustment. A total of 320 patients with gram-negative bacterial infection (airway, blood, or pleural effusion) were selected and a prospective cohort study was conducted. Baseline characteristics and outcomes (microbiologic, clinical, and economic) were documented during follow-up. MDR and nosocomial infections were common among subjects. Initial therapies consistent with MST could result in reduced in-hospital mortality, treatment failure rate, infection-related death, percentages of patients needing therapy adjustment, and daily hospitalization cost with increased successful treatment rate compared with inconsistent with MST, and microbiologic outcomes were also better with appropriate therapies. For patients needing therapy adjustment, relying on MST gained no significant benefit on mortality, clinical, or microbiologic outcomes compared with depending on clinical experience. But for patients with MDR infection, adjustment relying on MST gained more benefit than non-MDR infection. Appropriate initial therapy significantly improved the prognosis of patients with gram-negative bacterial infections, but improvement was not that obvious for patients needing therapy adjustment which was based on MST compared with clinical experience, and more beneficial effects of adjustment relying on MST were obtained for patients with MDR bacterial infection. PMID:28353572

  4. Comparative multilocus phylogeography of two Palaearctic spruce bark beetles: influence of contrasting ecological strategies on genetic variation.

    PubMed

    Mayer, François; Piel, Frédéric B; Cassel-Lundhagen, Anna; Kirichenko, Natalia; Grumiau, Laurent; Økland, Bjørn; Bertheau, Coralie; Grégoire, Jean-Claude; Mardulyn, Patrick

    2015-03-01

    While phylogeographic patterns of organisms are often interpreted through past environmental disturbances, mediated by climate changes, and geographic barriers, they may also be strongly influenced by species-specific traits. To investigate the impact of such traits, we focused on two Eurasian spruce bark beetles that share a similar geographic distribution, but differ in their ecology and reproduction. Ips typographus is an aggressive tree-killing species characterized by strong dispersal, whereas Dendroctonus micans is a discrete inbreeding species (sib mating is the rule), parasite of living trees and a poor disperser. We compared genetic variation between the two species over both beetles' entire range in Eurasia with five independent gene fragments, to evaluate whether their intrinsic differences could have an influence over their phylogeographic patterns. We highlighted widely divergent patterns of genetic variation for the two species and argue that the difference is indeed largely compatible with their contrasting dispersal strategies and modes of reproduction. In addition, genetic structure in I. typographus divides European populations in a northern and a southern group, as was previously observed for its host plant, and suggests past allopatric divergence. A long divergence time was estimated between East Asian and other populations of both species, indicating their long-standing presence in Eurasia, prior to the last glacial maximum. Finally, the strong population structure observed in D. micans for the mitochondrial locus provides insights into the recent colonization history of this species, from its native European range to regions where it was recently introduced.

  5. Oomycete Interactions with Plants: Infection Strategies and Resistance Principles

    PubMed Central

    Doumane, Mehdi

    2015-01-01

    SUMMARY The Oomycota include many economically significant microbial pathogens of crop species. Understanding the mechanisms by which oomycetes infect plants and identifying methods to provide durable resistance are major research goals. Over the last few years, many elicitors that trigger plant immunity have been identified, as well as host genes that mediate susceptibility to oomycete pathogens. The mechanisms behind these processes have subsequently been investigated and many new discoveries made, marking a period of exciting research in the oomycete pathology field. This review provides an introduction to our current knowledge of the pathogenic mechanisms used by oomycetes, including elicitors and effectors, plus an overview of the major principles of host resistance: the established R gene hypothesis and the more recently defined susceptibility (S) gene model. Future directions for development of oomycete-resistant plants are discussed, along with ways that recent discoveries in the field of oomycete-plant interactions are generating novel means of studying how pathogen and symbiont colonizations overlap. PMID:26041933

  6. Antifungal Resistance and New Strategies to Control Fungal Infections

    PubMed Central

    Vandeputte, Patrick; Ferrari, Selene; Coste, Alix T.

    2012-01-01

    Despite improvement of antifungal therapies over the last 30 years, the phenomenon of antifungal resistance is still of major concern in clinical practice. In the last 10 years the molecular mechanisms underlying this phenomenon were extensively unraveled. In this paper, after a brief overview of currently available antifungals, molecular mechanisms of antifungal resistance will be detailed. It appears that major mechanisms of resistance are essential due to the deregulation of antifungal resistance effector genes. This deregulation is a consequence of point mutations occurring in transcriptional regulators of these effector genes. Resistance can also follow the emergence of point mutations directly in the genes coding antifungal targets. In addition we further describe new strategies currently undertaken to discover alternative therapy targets and antifungals. Identification of new antifungals is essentially achieved by the screening of natural or synthetic chemical compound collections. Discovery of new putative antifungal targets is performed through genome-wide approaches for a better understanding of the human pathogenic fungi biology. PMID:22187560

  7. Contrasting Spatial Distribution and Risk Factors for Past Infection with Scrub Typhus and Murine Typhus in Vientiane City, Lao PDR

    PubMed Central

    Vallée, Julie; Thaojaikong, Thaksinaporn; Moore, Catrin E.; Phetsouvanh, Rattanaphone; Richards, Allen L.; Souris, Marc; Fournet, Florence; Salem, Gérard; Gonzalez, Jean-Paul J.; Newton, Paul N.

    2010-01-01

    Background The aetiological diagnostic of fevers in Laos remains difficult due to limited laboratory diagnostic facilities. However, it has recently become apparent that both scrub and murine typhus are common causes of previous undiagnosed fever. Epidemiological data suggests that scrub typhus would be more common in rural areas and murine typhus in urban areas, but there is very little recent information on factors involved in scrub and murine typhus transmission, especially where they are sympatric - as is the case in Vientiane, the capital of the Lao PDR. Methodology and Principal Findings We therefore determined the frequency of IgG seropositivity against scrub typhus (Orientia tsutsugamushi) and murine typhus (Rickettsia typhi), as indices of prior exposure to these pathogens, in randomly selected adults in urban and peri-urban Vientiane City (n = 2,002, ≥35 years). Anti-scrub and murine typhus IgG were detected by ELISA assays using filter paper elutes. We validated the accuracy of ELISA of these elutes against ELISA using serum samples. The overall prevalence of scrub and murine typhus IgG antibodies was 20.3% and 20.6%, respectively. Scrub typhus seropositivity was significantly higher among adults living in the periphery (28.4%) than in the central zone (13.1%) of Vientiane. In contrast, seroprevalence of murine typhus IgG antibodies was significantly higher in the central zone (30.8%) as compared to the periphery (14.4%). In multivariate analysis, adults with a longer residence in Vientiane were at significant greater risk of past infection with murine typhus and at lower risk for scrub typhus. Those with no education, living on low incomes, living on plots of land with poor sanitary conditions, living in large households, and farmers were at higher risk of scrub typhus and those living in neighborhoods with high building density and close to markets were at greater risk for murine typhus and at lower risk of scrub typhus past infection

  8. The immunology of human cytomegalovirus latency: could latent infection be cleared by novel immunotherapeutic strategies?

    PubMed

    Wills, Mark R; Poole, Emma; Lau, Betty; Krishna, Ben; Sinclair, John H

    2015-03-01

    While the host immune response following primary human cytomegalovirus (HCMV) infection is generally effective at stopping virus replication and dissemination, virus is never cleared by the host and like all herpesviruses, persists for life. At least in part, this persistence is known to be facilitated by the ability of HCMV to establish latency in myeloid cells in which infection is essentially silent with, importantly, a total lack of new virus production. However, although the viral transcription programme during latency is much suppressed, a number of viral genes are expressed during latent infection at the protein level and many of these have been shown to have profound effects on the latent cell and its environment. Intriguingly, many of these latency-associated genes are also expressed during lytic infection. Therefore, why the same potent host immune responses generated during lytic infection to these viral gene products are not recognized during latency, thereby allowing clearance of latently infected cells, is far from clear. Reactivation from latency is also a major cause of HCMV-mediated disease, particularly in the immune compromised and immune naive, and is also likely to be a major source of virus in chronic subclinical HCMV infection which has been suggested to be associated with long-term diseases such as atherosclerosis and some neoplasias. Consequently, understanding latency and why latently infected cells appear to be immunoprivileged is crucial for an understanding of the pathogenesis of HCMV and may help to design strategies to eliminate latent virus reservoirs, at least in certain clinical settings.

  9. Prevention of catheter-associated urinary tract infection: implementation strategies of international guidelines1

    PubMed Central

    Andrade, Vera Lúcia Fonseca; Fernandes, Filipa Alexandra Veludo

    2016-01-01

    Objective to describe strategies used by health professionals on the implementation of the Centers for Disease Control and Prevention guidelines for the prevention of urinary infection related to catheterism. Method systematic review on literature based on data from CINAHL(r), Nursing & Allied Health Collection, Cochrane Plus Collection, MedicLatina, MEDLINE(r), Academic Search Complete, ACS - American Chemical Society, Health Reference Center Academic, Nursing Reference Center, ScienceDirect Journals and Wiley Online Library. A sample of 13 articles was selected. Results studies have highlighted the decrease of urinary tract infection related to catheterism through reminder systems to decrease of people submitted to urinary catheterism, audits about nursing professionals practice and bundles expansion. Conclusion the present review systemizes the knowledge of used strategies by health professionals on introduction to international recommendations, describing a rate decrease of such infection in clinical practice. PMID:27027676

  10. Healthcare Outbreaks Associated With a Water Reservoir and Infection Prevention Strategies.

    PubMed

    Kanamori, Hajime; Weber, David J; Rutala, William A

    2016-06-01

    Hospital water may serve as a reservoir of healthcare-associated pathogens, and contaminated water can lead to outbreaks and severe infections. The clinical features of waterborne outbreaks and infections as well as prevention strategies and control measures are reviewed. The common waterborne pathogens were bacteria, including Legionella and other gram-negative bacteria, and nontuberculous mycobacteria, although fungi and viruses were occasionally described. These pathogens caused a variety of infections, including bacteremia and invasive and disseminated diseases, particularly among immunocompromised hosts and critically ill adults as well as neonates. Waterborne outbreaks occurred in healthcare settings with emergence of new reported reservoirs, including electronic faucets (Pseudomonas aeruginosa and Legionella), decorative water wall fountains (Legionella), and heater-cooler devices used in cardiac surgery (Mycobacterium chimaera). Advanced molecular techniques are useful for achieving a better understanding of reservoirs and transmission pathways of waterborne pathogens. Developing prevention strategies based on water reservoirs provides a practical approach for healthcare personnel.

  11. The EPIICAL project: an emerging global collaboration to investigate immunotherapeutic strategies in HIV-infected children.

    PubMed

    Palma, P; Foster, C; Rojo, P; Zangari, P; Yates, A; Cotugno, N; Klein, N; Luzuriaga, K; Pahwa, S; Nastouli, E; Gibb, D M; Borkowsky, W; Bernardi, S; Calvez, V; Manno, E; Mora, Nadia; Compagnucci, A; Wahren, B; Muñoz-Fernández, Má; De Rossi, A; Ananworanich, J; Pillay, D; Giaquinto, C; Rossi, P

    The EPIICAL (Early-treated Perinatally HIV-infected Individuals: Improving Children's Actual Life with Novel Immunotherapeutic Strategies) project arises from the firm belief that perinatally infected children treated with suppressive antiretroviral therapy (ART) from early infancy represent the optimal population model in which to study novel immunotherapeutic strategies aimed at achieving ART-free remission. This is because HIV-infected infants treated within 2-3 months of life have a much reduced viral reservoir size, and rarely show HIV-specific immunity but preserve normal immune development. The goal of EPIICAL is the establishment of an international collaboration to develop a predictive platform using this model to select promising HIV therapeutic vaccine candidates, leading to prioritisation or deprioritisation of novel immunotherapeutic strategies. To establish this platform, the EPIICAL Consortium aims to: develop predictive models of virological and immunological dynamics associated with response to early ART and to treatment interruption using available data from existing cohorts/studies of early-treated perinatally HIV-infected children; optimise methodologies to better characterise immunological, virological and genomic correlates/profiles associated with viral control; test novel immunotherapeutic strategies using in vivo proof-of-concept (PoC) studies with the aim of inducing virological, immunological and transcriptomic correlates/profiles equivalent to those defined by the predictive model. This approach will strengthen the capacity for discovery, development and initial testing of new therapeutic vaccine strategies through the integrated efforts of leading international scientific groups, with the aim of improving the health of HIV-infected individuals.

  12. Receptivity of female Neohelice granulata (Brachyura, Varunidae): different strategies to maximize their reproductive success in contrasting habitats

    NASA Astrophysics Data System (ADS)

    Sal Moyano, María Paz; Luppi, Tomás; Gavio, María Andrea; Vallina, Micaela; McLay, Colin

    2012-12-01

    The extent of the receptive period may determine the mating strategies employed by female crabs to obtain mates. Here, we studied the receptivity of female Neohelice granulata (Dana, 1851) in the laboratory, including the form of the vulvae and the anatomy of the seminal receptacle (SR). We examined the factors that influence the duration of receptivity by comparing two populations inhabiting contrasting habitats: Mar Chiquita Coastal lagoon (MCL), which is an oligo-polyhaline estuary, and San Antonio Oeste (SAO), which is an eu-hyperhaline marine bay. Non-receptive females have immobile vulva opercula, while receptive females have mobile opercula. Histological sections of the SR showed that the degree of epithelium secretions was associated with the receptive stage of females, and they may be involved in the maintenance of viable sperm and in the dehiscence of spermatophores. The existence of a special tissue at the junction of the oviduct and the SR was described and proposed as an internal mechanism influencing the timing of ovulation. The duration of receptivity was dependent on the SR load and the capacity to lay eggs. Thus, females with empty SR exhibited longer receptivity and did not lay eggs, while those with full SR exhibited shorter receptivity and always laid eggs. Interpopulation differences showed that females from SAO had shorter receptivity and heavier SR and laid eggs more frequently than females from MCL. Based on our results, we suggest that N. granulata females can adjust the duration of their receptivity and control the moment of fertilization according to different internal mechanisms related to the morphology of the vulvae, the fullness of the SR and anatomical attributes of the SR. An important consequence of this control is greater sperm competition. The extent of the receptive period and the number of times that a female could become receptive in a single reproductive season may also depend on the habitat characteristics.

  13. The Rise and Fall of an Evolutionary Innovation: Contrasting Strategies of Venom Evolution in Ancient and Young Animals

    PubMed Central

    Sunagar, Kartik; Moran, Yehu

    2015-01-01

    Animal venoms are theorized to evolve under the significant influence of positive Darwinian selection in a chemical arms race scenario, where the evolution of venom resistance in prey and the invention of potent venom in the secreting animal exert reciprocal selection pressures. Venom research to date has mainly focused on evolutionarily younger lineages, such as snakes and cone snails, while mostly neglecting ancient clades (e.g., cnidarians, coleoids, spiders and centipedes). By examining genome, venom-gland transcriptome and sequences from the public repositories, we report the molecular evolutionary regimes of several centipede and spider toxin families, which surprisingly accumulated low-levels of sequence variations, despite their long evolutionary histories. Molecular evolutionary assessment of over 3500 nucleotide sequences from 85 toxin families spanning the breadth of the animal kingdom has unraveled a contrasting evolutionary strategy employed by ancient and evolutionarily young clades. We show that the venoms of ancient lineages remarkably evolve under the heavy constraints of negative selection, while toxin families in lineages that originated relatively recently rapidly diversify under the influence of positive selection. We propose that animal venoms mostly employ a ‘two-speed’ mode of evolution, where the major influence of diversifying selection accompanies the earlier stages of ecological specialization (e.g., diet and range expansion) in the evolutionary history of the species–the period of expansion, resulting in the rapid diversification of the venom arsenal, followed by longer periods of purifying selection that preserve the potent toxin pharmacopeia–the period of purification and fixation. However, species in the period of purification may re-enter the period of expansion upon experiencing a major shift in ecology or environment. Thus, we highlight for the first time the significant roles of purifying and episodic selections in

  14. Strategies to Prevent Surgical Site Infections in Acute Care Hospitals: 2014 Update

    PubMed Central

    Anderson, Deverick J.; Podgorny, Kelly; Berríos-Torres, Sandra I.; Bratzler, Dale W.; Dellinger, E. Patchen; Greene, Linda; Nyquist, Ann-Christine; Saiman, Lisa; Yokoe, Deborah S.; Maragakis, Lisa L.; Kaye, Keith S.

    2014-01-01

    PURPOSE Previously published guidelines are available that provide comprehensive recommendations for detecting and preventing healthcare-associated infections (HAIs). The intent of this document is to highlight practical recommendations in a concise format designed to assist acute care hospitals in implementing and prioritizing their surgical site infection (SSI) prevention efforts. This document updates “Strategies to Prevent Surgical Site Infections in Acute Care Hospitals,”1 published in 2008. This expert guidance document is sponsored by the Society for Healthcare Epidemiology of America (SHEA) and is the product of a collaborative effort led by SHEA, the Infectious Diseases Society of America (IDSA), the American Hospital Association (AHA), the Association for Professionals in Infection Control and Epidemiology (APIC), and The Joint Commission, with major contributions from representatives of a number of organizations and societies with content expertise. The list of endorsing and supporting organizations is presented in the introduction to the 2014 updates.2 PMID:24799638

  15. Outcomes of co-infection by two potyviruses: implications for the evolution of manipulative strategies

    PubMed Central

    Salvaudon, Lucie; De Moraes, Consuelo M.; Mescher, Mark C.

    2013-01-01

    Recent studies have documented effects of plant viruses on host plants that appear to enhance transmission by insect vectors. But, almost no empirical work has explored the implications of such apparent manipulation for interactions among co-infecting pathogens. We examined single and mixed infections of two potyviruses, watermelon mosaic virus (WMV) and zucchini yellow mosaic virus (ZYMV), that frequently co-occur in cucurbitaceae populations and share the same aphid vectors. We found that ZYMV isolates replicated at similar rates in single and mixed infections, whereas WMV strains accumulated to significantly lower levels in the presence of ZYMV. Furthermore, ZYMV induced changes in leaf colour and volatile emissions that enhanced aphid (Aphis gossypii) recruitment to infected plants. By contrast, WMV did not elicit strong effects on plant–aphid interactions. Nevertheless, WMV was still readily transmitted from mixed infections, despite fairing poorly in in-plant competition. These findings suggest that pathogen effects on host–vector interactions may well influence competition among co-infecting pathogens. For example, if non-manipulative pathogens benefit from the increased vector traffic elicited by manipulative competitors, their costs of competition may be mitigated to some extent. Conversely, the benefits of manipulation may be limited by free-rider effects in systems where there is strong competition among pathogens for host resources and/or access to vectors. PMID:23407835

  16. Outcomes of co-infection by two potyviruses: implications for the evolution of manipulative strategies.

    PubMed

    Salvaudon, Lucie; De Moraes, Consuelo M; Mescher, Mark C

    2013-04-07

    Recent studies have documented effects of plant viruses on host plants that appear to enhance transmission by insect vectors. But, almost no empirical work has explored the implications of such apparent manipulation for interactions among co-infecting pathogens. We examined single and mixed infections of two potyviruses, watermelon mosaic virus (WMV) and zucchini yellow mosaic virus (ZYMV), that frequently co-occur in cucurbitaceae populations and share the same aphid vectors. We found that ZYMV isolates replicated at similar rates in single and mixed infections, whereas WMV strains accumulated to significantly lower levels in the presence of ZYMV. Furthermore, ZYMV induced changes in leaf colour and volatile emissions that enhanced aphid (Aphis gossypii) recruitment to infected plants. By contrast, WMV did not elicit strong effects on plant-aphid interactions. Nevertheless, WMV was still readily transmitted from mixed infections, despite fairing poorly in in-plant competition. These findings suggest that pathogen effects on host-vector interactions may well influence competition among co-infecting pathogens. For example, if non-manipulative pathogens benefit from the increased vector traffic elicited by manipulative competitors, their costs of competition may be mitigated to some extent. Conversely, the benefits of manipulation may be limited by free-rider effects in systems where there is strong competition among pathogens for host resources and/or access to vectors.

  17. Host Life History Strategy, Species Diversity, and Habitat Influence Trypanosoma cruzi Vector Infection in Changing Landscapes

    PubMed Central

    Gottdenker, Nicole L.; Chaves, Luis Fernando; Calzada, José E.; Saldaña, Azael; Carroll, C. Ronald

    2012-01-01

    Background Anthropogenic land use may influence transmission of multi-host vector-borne pathogens by changing diversity, relative abundance, and community composition of reservoir hosts. These reservoir hosts may have varying competence for vector-borne pathogens depending on species-specific characteristics, such as life history strategy. The objective of this study is to evaluate how anthropogenic land use change influences blood meal species composition and the effects of changing blood meal species composition on the parasite infection rate of the Chagas disease vector Rhodnius pallescens in Panama. Methodology/Principal Findings R. pallescens vectors (N = 643) were collected in different habitat types across a gradient of anthropogenic disturbance. Blood meal species in DNA extracted from these vectors was identified in 243 (40.3%) vectors by amplification and sequencing of a vertebrate-specific fragment of the 12SrRNA gene, and T. cruzi vector infection was determined by pcr. Vector infection rate was significantly greater in deforested habitats as compared to contiguous forests. Forty-two different species of blood meal were identified in R. pallescens, and species composition of blood meals varied across habitat types. Mammals (88.3%) dominated R. pallescens blood meals. Xenarthrans (sloths and tamanduas) were the most frequently identified species in blood meals across all habitat types. A regression tree analysis indicated that blood meal species diversity, host life history strategy (measured as rmax, the maximum intrinsic rate of population increase), and habitat type (forest fragments and peridomiciliary sites) were important determinants of vector infection with T. cruzi. The mean intrinsic rate of increase and the skewness and variability of rmax were positively associated with higher vector infection rate at a site. Conclusions/Significance In this study, anthropogenic landscape disturbance increased vector infection with T. cruzi, potentially

  18. Effectiveness of nitrate addition and increased oil content as methane mitigation strategies for beef cattle fed two contrasting basal diets.

    PubMed

    Troy, S M; Duthie, C-A; Hyslop, J J; Roehe, R; Ross, D W; Wallace, R J; Waterhouse, A; Rooke, J A

    2015-04-01

    The objectives of this study were to investigate the effects of (1) the addition of nitrate and (2) an increase in dietary oil on methane (CH4) and hydrogen (H2) emissions from 2 breeds (cross-bred Charolais and purebred Luing) of finishing beef cattle receiving 2 contrasting basal diets consisting (grams per kilogram DM) of 500:500 (Mixed) and 80:920 (Concentrate) forage to concentrate ratios. Within each basal diet there were 3 treatments: (i) control treatments (mixed-CTL and concentrate-CTL) contained rapeseed meal as the protein source, which was replaced with either (ii) calcium nitrate (mixed-NIT and concentrate-NIT) supplying 21.5 g nitrate/kg DM, or (iii) rapeseed cake (mixed-RSC and concentrate-RSC) to increase dietary oil from 27 (CTL) to 53 g/kg DM (RSC). Following adaption to diets, CH4 and H2 emissions were measured on 1 occasion from each of the 76 steers over a 13-wk period. Dry matter intakes tended (P = 0.051) to be greater for the concentrate diet than the mixed diet; however, when expressed as grams DMI per kilogram BW, there was no difference between diets (P = 0.41). Dry matter intakes for NIT or RSC did not differ from CTL. Steers fed a concentrate diet produced less CH4 and H2 than those fed a mixed diet (P < 0.001). Molar proportions of acetate (P < 0.001) and butyrate (P < 0.01) were lower and propionate (P < 0.001) and valerate (P < 0.05) higher in the rumen fluid from steers fed the concentrate diet. For the mixed diet, CH4 yield (grams per kilogram DMI) was decreased by 17% when nitrate was added (P < 0.01), while H2 yield increased by 160% (P < 0.001). The addition of RSC to the mixed diet decreased CH4 yield by 7.5% (P = 0.18). However, for the concentrate diet neither addition of nitrate (P = 0.65) nor increasing dietary oil content (P = 0.46) decreased CH4 yield compared to concentrate-CTL. Molar proportions of acetate were higher (P < 0.001) and those of propionate lower (P < 0.01) in rumen fluid from NIT treatments compared to

  19. Protective effect of a prime-boost strategy with plasmid DNA followed by recombinant adenovirus expressing TgAMA1 as vaccines against Toxoplasma gondii infection in mice.

    PubMed

    Yu, Longzheng; Yamagishi, Junya; Zhang, Shoufa; Jin, Chunmei; Aboge, Gabriel Oluga; Zhang, Houshuang; Zhang, Guohong; Tanaka, Tetsuya; Fujisaki, Kozo; Nishikawa, Yoshifumi; Xuan, Xuenan

    2012-09-01

    A heterologous prime-boost strategy with priming plasmid DNA followed by recombinant virus expressing relevant antigens is known to stimulate protective immunity against intracellular parasites. In this study, we have evaluated a heterologous prime-boost strategy for immunizing mice against Toxoplasma gondii infection. Our results revealed that the prime-boost strategy using both plasmid DNA and adenoviral vector encoding TgAMA1 may stimulate both humoral and Th1/Th2 cellular immune responses specific for TgAMA1. Moreover, C57BL/6 mice immunized with the pAMA1/Ad5Null, pNull/Ad5AMA1, and pAMA1/Ad5AMA1 constructs showed survival rates of 12.5%, 37.5%, and 50%, respectively. In contrast, all the pNull/Ad5Null immunized mice died after infection with the PLK-GFP strain of T. gondii. Brain cyst burden was reduced by 23% in mice immunized with pAMA1/Ad5AMA1 compared with the pNull/Ad5AMA1 immunized mice. These results demonstrate that the heterologous DNA priming and recombinant adenovirus boost strategy may provide protective immunity against T. gondii infection.

  20. Pseudomonas aeruginosa adapts its iron uptake strategies in function of the type of infections.

    PubMed

    Cornelis, Pierre; Dingemans, Jozef

    2013-01-01

    Pseudomonas aeruginosa is a Gram-negative γ-Proteobacterium which is known for its capacity to colonize various niches, including some invertebrate and vertebrate hosts, making it one of the most frequent bacteria causing opportunistic infections. P. aeruginosa is able to cause acute as well as chronic infections and it uses different colonization and virulence factors to do so. Infections range from septicemia, urinary infections, burn wound colonization, and chronic colonization of the lungs of cystic fibrosis patients. Like the vast majority of organisms, P. aeruginosa needs iron to sustain growth. P. aeruginosa utilizes different strategies to take up iron, depending on the type of infection it causes. Two siderophores are produced by this bacterium, pyoverdine and pyochelin, characterized by high and low affinities for iron respectively. P. aeruginosa is also able to utilize different siderophores from other microorganisms (siderophore piracy). It can also take up heme from hemoproteins via two different systems. Under microaerobic or anaerobic conditions, P. aeruginosa is also able to take up ferrous iron via its Feo system using redox-cycling phenazines. Depending on the type of infection, P. aeruginosa can therefore adapt by switching from one iron uptake system to another as we will describe in this short review.

  1. Emerging therapeutic strategies to prevent infection-related microvascular endothelial activation and dysfunction

    PubMed Central

    Darwish, Ilyse; Liles, W Conrad

    2013-01-01

    Recent evidence suggests that loss of endothelial barrier function and resulting microvascular leak play important mechanistic roles in the pathogenesis of infection-related end-organ dysfunction and failure. Several distinct therapeutic strategies, designed to prevent or limit infection-related microvascular endothelial activation and permeability, thereby mitigating end-organ injury/dysfunction, have recently been investigated in pre-clinical models. In this review, these potential therapeutic strategies, namely, VEGFR2/Src antagonists, sphingosine-1-phosphate agonists, fibrinopeptide Bβ15–42, slit2N, secinH3, angiopoietin-1/tie-2 agonists, angiopoietin-2 antagonists, statins, atrial natriuretic peptide, and mesenchymal stromal (stem) cells, are discussed in terms of their translational potential for the management of clinical infectious diseases. PMID:23863603

  2. Loki-Infect 3 : a portable networked agent model for designing community-level containment strategies.

    SciTech Connect

    Evans, Leland B.; Cannon, Daniel C.; Hobbs, Jacob A.; Davey, Victoria J.; Glass, Robert John, Jr.

    2010-12-01

    Loki-Infect 3 is a desktop application intended for use by community-level decision makers. It allows rapid construction of small-scale studies of emerging or hypothetical infectious diseases in their communities and evaluation of the potential effectiveness of various containment strategies. It was designed with an emphasis on modularity, portability, and ease of use. Our goal is to make this program freely available to community workers across the world.

  3. Healthcare associated infection: novel strategies and antimicrobial implants to prevent surgical site infection

    PubMed Central

    Leaper, David; McBain, Andrew J; Kramer, Axel; Assadian, Ojan; Sanchez, Jose Luis Alfonso; Lumio, Jukka; Kiernan, Martin

    2010-01-01

    This report is based on a Hygienist Panel Meeting held at St Anne's Manor, Wokingham on 24–25 June 2009. The panel agreed that greater use should be made of antiseptics to reduce reliance on antibiotics with their associated risk of antibiotic resistance. When choosing an antiseptic for clinical use, the Biocompatibility Index, which considers both the microbiocidal activity and any cytotoxic effects of an antiseptic agent, was considered to be a useful tool. The need for longer and more proactive post-discharge surveillance of surgical patients was also agreed to be a priority, especially given the current growth of day-case surgery. The introduction of surgical safety checklists, such as the World Health Organization's Safe Surgery Saves Lives initiative, is a useful contribution to improving safety and prevention of SSIs and should be used universally. Considering sutures as ‘implants’, with a hard or non-shedding surface to which micro-organisms can form biofilm and cause surgical site infections, was felt to be a useful concept. PMID:20819330

  4. New Diagnostic Strategies for Detection of Helicobacter pylori Infection in Pediatric Patients

    PubMed Central

    Gold, Benjamin D.; Gilger, Mark A.; Czinn, Steven J.

    2014-01-01

    Helicobacter pylori (H pylori) is a common chronic bacterial infection that is an important cause of peptic ulcer disease and gastroduodenal disease in children. H pylori is also associated with extragastric manifestations, including growth reduction, iron-deficiency anemia, and idiopathic thrombocytopenic purpura. Current guidelines recommend endoscopy with biopsy for the definitive demonstration of H pylori infection. In contrast to serology, the fecal antigen test and the urea breath test provide reliable, sensitive, and specific results for detecting active H pylori infection in children before and after treatment. The first-line treatment option for pediatric patients is triple therapy with a proton pump inhibitor and 2 antibiotics, which include amoxicillin and clarithromycin or metronidazole. Decreasing eradication rates and the emergence of antibiotic-resistant strains of H pylori have led to the use of other treatments, such as sequential therapy or triple therapy with newer antibiotics, particularly in geographic areas with high rates of antibiotic resistance. Patients should be tested after treatment to confirm eradication, as the absence of symptoms does not necessarily mean that H pylori is no longer present. This clinical roundtable monograph provides an overview of H pylori infection, as well as expert insight into the diagnosis and management of H pylori infection in children. PMID:26491414

  5. YELLOW FEVER PREVENTION STRATEGIES AWARENESS AMONG HIV-INFECTED PATIENTS IN SÃO PAULO, BRAZIL

    PubMed Central

    Avelino-Silva, Vivian Iida; Francelino, Hilario Sousa; Kallás, Esper Georges

    2014-01-01

    Introduction: Vaccination is the main preventive strategy against Yellow Fever (YF), which is a public health concern in Brazil. However, HIV-infected patients might have insufficient knowledge regarding YF, YF prevention, and vaccines in general. Methods: In this questionnaire-based study, data from 158 HIV-infected individuals were addressed in three distinct outpatient clinics in São Paulo. Information was collected on demographic and clinical characteristics, as well as patients' knowledge of vaccines, YF and YF preventive strategies. In addition, individual YF vaccine recommendations and vaccine status were investigated. Results: Although most participants adequately ascertain the vaccine as the main prevention strategy against YF, few participants were aware of the severity and lack of specific treatment for YF. Discrepancy in YF vaccine (patients who should have taken the vaccine, but did not) was observed in 18.8% of participants. Conclusion: YF is an important and preventable public health concern, and these results demonstrate that more information is necessary for the HIV-infected population. PMID:25229222

  6. Controlled Mycobacterium tuberculosis infection in mice under treatment with anti-IL-17A or IL-17F antibodies, in contrast to TNFα neutralization

    PubMed Central

    Segueni, Noria; Tritto, Elaine; Bourigault, Marie-Laure; Rose, Stéphanie; Erard, François; Le Bert, Marc; Jacobs, Muazzam; Di Padova, Franco; Stiehl, Daniel P.; Moulin, Pierre; Brees, Dominique; Chibout, Salah-Dine; Ryffel, Bernhard; Kammüller, Michael; Quesniaux, Valerie F.

    2016-01-01

    Antibodies targeting IL-17A or its receptor IL-17RA show unprecedented efficacy in the treatment of autoimmune diseases such as psoriasis. These therapies, by neutralizing critical mediators of immunity, may increase susceptibility to infections. Here, we compared the effect of antibodies neutralizing IL-17A, IL-17F or TNFα on murine host responses to Mycobacterium tuberculosis infection by evaluating lung transcriptomic, microbiological and histological analyses. Coinciding with a significant increase of mycobacterial burden and pathological changes following TNFα blockade, gene array analyses of infected lungs revealed major changes of inflammatory and immune gene expression signatures 4 weeks post-infection. Specifically, gene expression associated with host-pathogen interactions, macrophage recruitment, activation and polarization, host-antimycobacterial activities, immunomodulatory responses, as well as extracellular matrix metallopeptidases, were markedly modulated by TNFα blockade. IL-17A or IL-17F neutralization elicited only mild changes of few genes without impaired host resistance four weeks after M. tuberculosis infection. Further, the absence of both IL-17RA and IL-22 pathways in genetically deficient mice did not profoundly compromise host control of M. tuberculosis over a 6-months period, ruling out potential compensation between these two pathways, while TNFα-deficient mice succumbed rapidly. These data provide experimental confirmation of the low clinical risk of mycobacterial infection under anti-IL-17A therapy, in contrast to anti-TNFα treatment. PMID:27853279

  7. Introduced and native congeners use different resource allocation strategies to maintain performance during infection.

    PubMed

    Coon, Courtney A C; Brace, Amber J; McWilliams, Scott R; McCue, Marshall D; Martin, Lynn B

    2014-01-01

    Abstract Hosts can manage parasitic infections using an array of tactics, which are likely to vary contingent on coevolutionary history between the host and the parasite. Here we asked whether coping ability of congeners that differ in host-parasite coevolutionary history differed in response to experimental infections with a coccidian parasite. House sparrows (Passer domesticus) and gray-headed sparrows (Passer griseus) are sympatric and ecologically similar, but house sparrows are recent colonizers of Kenya, the site of our comparison, whereas gray-headed sparrows are native. We evaluated three variables as barometers of infection coping ability: vertical flight, pectoral muscle size, and fat score. We also measured routing of a dose of (13)C-labeled leucine, an essential amino acid, among tissues to compare resource allocation strategies in response to infection. We found that burden effects on performance were minimal in both species, but house sparrows maintained considerably higher burdens than gray-headed sparrows regardless of exposure. House sparrows also had more exogeneous leucine tracer in all tissues after 24 h, demonstrating a difference in the way the two species allocate or distribute resources. We argue that house sparrows may be maintaining larger resource reserves to mitigate costs associated with exposure and infection. Additionally, in response to increased parasite exposure, gray-headed sparrows had less leucine tracer in their spleens and more in their gonads, whereas house sparrows did not change allocation, perhaps indicating a trade-off that is not experienced by the introduced species.

  8. Simple strategies to reduce healthcare associated infections in the neonatal intensive care unit: line, tube, and hand hygiene.

    PubMed

    Graham, Philip L

    2010-09-01

    This article describes strategies to prevent 2 important healthcare associated infections in the neonatal intensive care unit: central line-associated bloodstream infections and catheter-associated urinary tract infections. Hand hygiene is discussed as the cornerstone for prevention of all healthcare associated infections. Specific recommendations for education and training of health care personnel who insert and maintain central venous catheters and urinary tract catheters are made and best practices for insertion and maintenance of these catheters are discussed. Throughout this article, the emphasis is on prevention of these high morbidity and mortality healthcare associated infections.

  9. Contrasting expression of immune genes in scaled and scaleless skin of Atlantic salmon infected with young stages of Lepeophtheirus salmonis.

    PubMed

    Holm, H Jodaa; Skugor, S; Bjelland, A K; Radunovic, S; Wadsworth, S; Koppang, E O; Evensen, Ø

    2017-02-01

    Atlantic salmon skin tissues with and without scales were taken from two preferred sites of salmon louse (Lepeophtheirus salmonis) attachment, behind the dorsal fin (scaled) and from the top of the head (scaleless), respectively. Tissues were profiled by qPCR of 32 genes to study responses to copepodids, 4 days post infection (dpi), and during the moult of copepodids to the chalimus stage, at 8 dpi. Basal/constitutive differences were found for many immune-related genes between the two skin sites; e.g., mannose binding protein C was over 100 fold higher expressed in the scaled skin from the back in comparison to the skin without scales from the head. With lice-infection, at 4 dpi most genes in both tissues showed lower values than in the non-infected control. By 8 dpi, the majority of responses increased towards the control levels, including cytokines of Th1, Th17 and Th2 pathways. Immunohistochemistry of three immune factors revealed an even distribution of MHC class II positive cells throughout epidermis, including the top layer of keratinocytes, marked compartmentalization of Mx(+) and CD8α(+) cells close to stratum basale, and an increase in numbers of CD8α(+) cells in response to infection. In conclusion, suppression of immune genes during the copepodid stage likely sets off a beneficial situation for the parasite. At the moult to chalimus stage 8 dpi, only few genes surpassed the non-infected control levels, including CD8α. The gene expression pattern was reflected in the increased number of CD8α expressing cells, thus revealing a relatively minor activation of skin T-cell defenses in Atlantic salmon in response to L. salmonis infection.

  10. Evaluating Infection Prevention Strategies in Out-Patient Dialysis Units Using Agent-Based Modeling.

    PubMed

    Wares, Joanna R; Lawson, Barry; Shemin, Douglas; D'Agata, Erika M C

    2016-01-01

    Patients receiving chronic hemodialysis (CHD) are among the most vulnerable to infections caused by multidrug-resistant organisms (MDRO), which are associated with high rates of morbidity and mortality. Current guidelines to reduce transmission of MDRO in the out-patient dialysis unit are targeted at patients considered to be high-risk for transmitting these organisms: those with infected skin wounds not contained by a dressing, or those with fecal incontinence or uncontrolled diarrhea. Here, we hypothesize that targeting patients receiving antimicrobial treatment would more effectively reduce transmission and acquisition of MDRO. We also hypothesize that environmental contamination plays a role in the dissemination of MDRO in the dialysis unit. To address our hypotheses, we built an agent-based model to simulate different treatment strategies in a dialysis unit. Our results suggest that reducing antimicrobial treatment, either by reducing the number of patients receiving treatment or by reducing the duration of the treatment, markedly reduces overall colonization rates and also the levels of environmental contamination in the dialysis unit. Our results also suggest that improving the environmental decontamination efficacy between patient dialysis treatments is an effective method for reducing colonization and contamination rates. These findings have important implications for the development and implementation of future infection prevention strategies.

  11. Immune surveillance mechanisms of the skin against the stealth infection strategy of Pseudomonas aeruginosa-review.

    PubMed

    Andonova, Maria; Urumova, Valentina

    2013-09-01

    The present review aims to provide insight into the complex interactions between the host and Pseudomonas aeruginosa-an opportunistic microbial agent causing skin infections. Heat, humidity and skin pH are among the factors beneficial for the development of this Gram-negative agent. To cause infection, Pseudomonas aeruginosa should first overcome the primary mechanisms of defense including the cell elements and humoral factors of the skin, as well as non-specific responses-phagocytosis, inflammation, acute phase response. All they are analysed with emphasis on the fact that their detailed understanding would help revealing their potential and allow for their efficient control. The microorganism, being more alterable and more flexible than the host, uses stealth strategies and modes of life. The review goes over the arsenal of virulence factors, used by Pseudomonas aeruginosa to attack the host defense mechanisms. The bacterial pathogenic strategies for invasion, resulting in collapse of skin defense are analysed. Several novel therapeutic approached to Pseudomonas aeruginosa skin infections are briefly reviewed.

  12. Evaluation of testing strategies to identify infected animals at a single round of testing within dairy herds known to be infected with Mycobacterium avium ssp. paratuberculosis.

    PubMed

    More, S J; Cameron, A R; Strain, S; Cashman, W; Ezanno, P; Kenny, K; Fourichon, C; Graham, D

    2015-08-01

    As part of a broader control strategy within herds known to be infected with Mycobacterium avium ssp. paratuberculosis (MAP), individual animal testing is generally conducted to identify infected animals for action, usually culling. Opportunities are now available to quantitatively compare different testing strategies (combinations of tests) in known infected herds. This study evaluates the effectiveness, cost, and cost-effectiveness of different testing strategies to identify infected animals at a single round of testing within dairy herds known to be MAP infected. A model was developed, taking account of both within-herd infection dynamics and test performance, to simulate the use of different tests at a single round of testing in a known infected herd. Model inputs included the number of animals at different stages of infection, the sensitivity and specificity of each test, and the costs of testing and culling. Testing strategies included either milk or serum ELISA alone or with fecal culture in series. Model outputs included effectiveness (detection fraction, the proportion of truly infected animals in the herd that are successfully detected by the testing strategy), cost, and cost-effectiveness (testing cost per true positive detected, total cost per true positive detected). Several assumptions were made: MAP was introduced with a single animal and no management interventions were implemented to limit within-herd transmission of MAP before this test. In medium herds, between 7 and 26% of infected animals are detected at a single round of testing, the former using the milk ELISA and fecal culture in series 5 yr after MAP introduction and the latter using fecal culture alone 15 yr after MAP introduction. The combined costs of testing and culling at a single round of testing increases with time since introduction of MAP infection, with culling costs being much greater than testing costs. The cost-effectiveness of testing varied by testing strategy. It was also

  13. Spore Density Determines Infection Strategy by the Plant Pathogenic Fungus Plectosphaerella cucumerina1[OPEN

    PubMed Central

    2016-01-01

    Necrotrophic and biotrophic pathogens are resisted by different plant defenses. While necrotrophic pathogens are sensitive to jasmonic acid (JA)-dependent resistance, biotrophic pathogens are resisted by salicylic acid (SA)- and reactive oxygen species (ROS)-dependent resistance. Although many pathogens switch from biotrophy to necrotrophy during infection, little is known about the signals triggering this transition. This study is based on the observation that the early colonization pattern and symptom development by the ascomycete pathogen Plectosphaerella cucumerina (P. cucumerina) vary between inoculation methods. Using the Arabidopsis (Arabidopsis thaliana) defense response as a proxy for infection strategy, we examined whether P. cucumerina alternates between hemibiotrophic and necrotrophic lifestyles, depending on initial spore density and distribution on the leaf surface. Untargeted metabolome analysis revealed profound differences in metabolic defense signatures upon different inoculation methods. Quantification of JA and SA, marker gene expression, and cell death confirmed that infection from high spore densities activates JA-dependent defenses with excessive cell death, while infection from low spore densities induces SA-dependent defenses with lower levels of cell death. Phenotyping of Arabidopsis mutants in JA, SA, and ROS signaling confirmed that P. cucumerina is differentially resisted by JA- and SA/ROS-dependent defenses, depending on initial spore density and distribution on the leaf. Furthermore, in situ staining for early callose deposition at the infection sites revealed that necrotrophy by P. cucumerina is associated with elevated host defense. We conclude that P. cucumerina adapts to early-acting plant defenses by switching from a hemibiotrophic to a necrotrophic infection program, thereby gaining an advantage of immunity-related cell death in the host. PMID:26842622

  14. An insight into a combination of ELISA strategies to diagnose small ruminant lentivirus infections.

    PubMed

    de Andrés, X; Ramírez, H; Bertolotti, L; San Román, B; Glaria, I; Crespo, H; Jáuregui, P; Minguijón, E; Juste, R; Leginagoikoa, I; Pérez, M; Luján, L; Badiola, J J; Polledo, L; García-Marín, J F; Riezu, J I; Borrás-Cuesta, F; de Andrés, D; Rosati, S; Reina, R; Amorena, B

    2013-04-15

    A single broadly reactive standard ELISA is commonly applied to control small ruminant lentivirus (SRLV) spread, but type specific ELISA strategies are gaining interest in areas with highly prevalent and heterogeneous SRLV infections. Short (15-residue) synthetic peptides (n=60) were designed in this study using deduced amino acid sequence profiles of SRLV circulating in sheep from North Central Spain and SRLV described previously. The corresponding ELISAs and two standard ELISAs were employed to analyze sera from sheep flocks either controlled or infected with different SRLV genotypes. Two outbreaks, showing SRLV-induced arthritis (genotype B2) and encephalitis (genotype A), were represented among the infected flocks. The ELISA results revealed that none of the assays detected all the infected animals in the global population analyzed, the assay performance varying according to the genetic type of the strain circulating in the area and the test antigen. Five of the six highly reactive (57-62%) single peptide ELISAs were further assessed, revealing that the ELISA based on peptide 98M (type A ENV-SU5, consensus from the neurological outbreak) detected positives in the majority of the type-A specific sera tested (Se: 86%; Sp: 98%) and not in the arthritic type B outbreak. ENV-TM ELISAs based on peptides 126M1 (Se: 82%; Sp: 95%) and 126M2 0,65 0.77 (Se: 68%; Sp: 88%) detected preferentially caprine arthritis encephalitis (CAEV, type B) and visna/maedi (VMV, type A) virus infections respectively, which may help to perform a preliminary CAEV vs. VMV-like typing of the flock. The use of particular peptide ELISAs and standard tests individually or combined may be useful in the different areas under study, to determine disease progression, diagnose/type infection and prevent its spread.

  15. Strategies to enhance immune function in hematopoietic transplantation recipients who have fungal infections.

    PubMed

    Safdar, A

    2006-09-01

    The challenges in the treatment of systemic fungal infections after HSCT include: (1) changing epidemiology as less drug-susceptible saprophytic fungi are increasingly associated with human disease; (2) the difficulty of early and correct diagnosis, even with the new generation of enzymatic immunoassays; (3) the inability to reduce or eliminate predisposing factors, especially severe immune suppression in most transplant patients with these infections and (4) the uncertain role of antifungal drug combinations and risk of drug antagonism complicating effective empiric-pre-emptive therapy. Current, developing and future immune enhancement strategies including recombinant granulocyte- and granulocyte macrophage-colony stimulating factor (GM-CSF), interferon-gamma (IFN-gamma), adjuvant pro-inflammatory cytokine therapy during mobilized donor granulocyte transfusions, therapeutic potential of pentraxin, adaptive immune transfer and dendritic cell fungal vaccines. Improved understanding of the molecular pathogenesis of fungal infections and of the complexity of host antifungal immune responses has provided the critical information to readdress existing treatment paradigms and further evaluate the role of GM-CSF and IFN-gamma early in the course of therapy against life-threatening fungal infections in high-risk patients following stem cell transplantation.

  16. A Compendium of Strategies to Prevent Healthcare-Associated Infections in Acute Care Hospitals: 2014 Updates

    PubMed Central

    Yokoe, Deborah S.; Anderson, Deverick J.; Berenholtz, Sean M.; Calfee, David P.; Dubberke, Erik R.; Ellingson, Katherine D.; Gerding, Dale N.; Haas, Janet P.; Kaye, Keith S.; Klompas, Michael; Lo, Evelyn; Marschall, Jonas; Mermel, Leonard A.; Nicolle, Lindsay E.; Salgado, Cassandra D.; Bryant, Kristina; Classen, David; Crist, Katrina; Deloney, Valerie M.; Fishman, Neil O.; Foster, Nancy; Goldmann, Donald A.; Humphreys, Eve; Jernigan, John A.; Padberg, Jennifer; Perl, Trish M.; Podgorny, Kelly; Septimus, Edward J.; VanAmringe, Margaret; Weaver, Tom; Weinstein, Robert A.; Wise, Robert; Maragakis, Lisa L.

    2014-01-01

    Since the publication of “A Compendium of Strategies to Prevent Healthcare-Associated Infections in Acute Care Hospitals” in 2008, prevention of healthcare-associated infections (HAIs) has become a national priority. Despite improvements, preventable HAIs continue to occur. The 2014 updates to the Compendium were created to provide acute care hospitals with up-to-date, practical, expert guidance to assist in prioritizing and implementing their HAI prevention efforts. They are the product of a highly collaborative effort led by the Society for Healthcare Epidemiology of America (SHEA), the Infectious Diseases Society of America (IDSA), the American Hospital Association (AHA), the Association for Professionals in Infection Control and Epidemiology (APIC), and The Joint Commission, with major contributions from representatives of a number of organizations and societies with content expertise, including the Centers for Disease Control and Prevention (CDC), the Institute for Healthcare Improvement (IHI), the Pediatric Infectious Diseases Society (PIDS), the Society for Critical Care Medicine (SCCM), the Society for Hospital Medicine (SHM), and the Surgical Infection Society (SIS). PMID:25026611

  17. Strategies for managing systemic fungal infection and the place of itraconazole.

    PubMed

    Potter, Michael

    2005-09-01

    Systemic fungal infections are an increasing cause of mortality and morbidity in patients with haematological malignancies and certain other conditions associated with profound immunosuppression. The majority of such infections are caused by Aspergillus and Candida species. In recent years, the number of available drugs effective in the therapy of these difficult infections has expanded. Large clinical trials have been performed in different settings such as prophylaxis, empirical and first-line therapy. For prophylaxis, the azoles fluconazole and itraconazole have been most widely studied. These azoles are available in both oral and intravenous formulations. Itraconazole has a wide spectrum of activity including Aspergillus, Candida albicans and non-albicans species. Two large studies comparing the use of itraconazole with fluconazole for primary prophylaxis in high-risk patients who were recipients of allogeneic stem cell transplants have recently been reported. These have confirmed that itraconazole is effective in this setting in reducing the rate of systemic fungal infections. However, there are concerns with regard to increased toxicity and the potential for drug interactions with itraconazole compared with fluconazole. In the empirical setting, large randomized studies support the use of caspofungin and liposomal amphotericin B. Voriconazole and lipid-associated amphotericin B have been shown to be effective in first-line therapy and caspofungin for salvage. New approaches to management include efforts at improving diagnosis, combination antifungal therapy and treatment strategies for emerging moulds.

  18. A compendium of strategies to prevent healthcare-associated infections in acute care hospitals: 2014 updates.

    PubMed

    Yokoe, Deborah S; Anderson, Deverick J; Berenholtz, Sean M; Calfee, David P; Dubberke, Erik R; Ellingson, Katherine D; Gerding, Dale N; Haas, Janet P; Kaye, Keith S; Klompas, Michael; Lo, Evelyn; Marschall, Jonas; Mermel, Leonard A; Nicolle, Lindsay E; Salgado, Cassandra D; Bryant, Kristina; Classen, David; Crist, Katrina; Deloney, Valerie M; Fishman, Neil O; Foster, Nancy; Goldmann, Donald A; Humphreys, Eve; Jernigan, John A; Padberg, Jennifer; Perl, Trish M; Podgorny, Kelly; Septimus, Edward J; VanAmringe, Margaret; Weaver, Tom; Weinstein, Robert A; Wise, Robert; Maragakis, Lisa L

    2014-08-01

    Since the publication of "A Compendium of Strategies to Prevent Healthcare-Associated Infections in Acute Care Hospitals" in 2008, prevention of healthcare-associated infections (HAIs) has become a national priority. Despite improvements, preventable HAIs continue to occur. The 2014 updates to the Compendium were created to provide acute care hospitals with up-to-date, practical, expert guidance to assist in prioritizing and implementing their HAI prevention efforts. They are the product of a highly collaborative effort led by the Society for Healthcare Epidemiology of America (SHEA), the Infectious Diseases Society of America (IDSA), the American Hospital Association (AHA), the Association for Professionals in Infection Control and Epidemiology (APIC), and The Joint Commission, with major contributions from representatives of a number of organizations and societies with content expertise, including the Centers for Disease Control and Prevention (CDC), the Institute for Healthcare Improvement (IHI), the Pediatric Infectious Diseases Society (PIDS), the Society for Critical Care Medicine (SCCM), the Society for Hospital Medicine (SHM), and the Surgical Infection Society (SIS).

  19. A Compendium of Strategies to Prevent Healthcare-Associated Infections in Acute Care Hospitals: 2014 Updates.

    PubMed

    Yokoe, Deborah S; Anderson, Deverick J; Berenholtz, Sean M; Calfee, David P; Dubberke, Erik R; Ellingson, Katherine D; Gerding, Dale N; Haas, Janet P; Kaye, Keith S; Klompas, Michael; Lo, Evelyn; Marschall, Jonas; Mermel, Leonard A; Nicolle, Lindsay E; Salgado, Cassandra D; Bryant, Kristina; Classen, David; Crist, Katrina; Deloney, Valerie M; Fishman, Neil O; Foster, Nancy; Goldmann, Donald A; Humphreys, Eve; Jernigan, John A; Padberg, Jennifer; Perl, Trish M; Podgorny, Kelly; Septimus, Edward J; VanAmringe, Margaret; Weaver, Tom; Weinstein, Robert A; Wise, Robert; Maragakis, Lisa L

    2014-08-01

    Since the publication of "A Compendium of Strategies to Prevent Healthcare-Associated Infections in Acute Care Hospitals" in 2008, prevention of healthcare-associated infections (HAIs) has become a national priority. Despite improvements, preventable HAIs continue to occur. The 2014 updates to the Compendium were created to provide acute care hospitals with up-to-date, practical, expert guidance to assist in prioritizing and implementing their HAI prevention efforts. They are the product of a highly collaborative effort led by the Society for Healthcare Epidemiology of America (SHEA), the Infectious Diseases Society of America (IDSA), the American Hospital Association (AHA), the Association for Professionals in Infection Control and Epidemiology (APIC), and The Joint Commission, with major contributions from representatives of a number of organizations and societies with content expertise, including the Centers for Disease Control and Prevention (CDC), the Institute for Healthcare Improvement (IHI), the Pediatric Infectious Diseases Society (PIDS), the Society for Critical Care Medicine (SCCM), the Society for Hospital Medicine (SHM), and the Surgical Infection Society (SIS).

  20. Molecular Profiles of Contrasting Shade Response Strategies in Wild Plants: Differential Control of Immunity and Shoot Elongation[OPEN

    PubMed Central

    Keuskamp, Diederik H.; Buti, Sara; van Veen, Hans; Reinen, Emilie; Voesenek, Laurentius A.C.J.

    2017-01-01

    Plants growing at high densities elongate their shoots to reach for light, a response known as the shade avoidance syndrome (SAS). Phytochrome-mediated detection of far-red light reflection from neighboring plants activates growth-promoting molecular pathways leading to SAS. However, it is unknown how plants that complete their life cycle in the forest understory and are shade tolerant prevent SAS when exposed to shade. Here, we show how two wild Geranium species from different native light environments regulate contrasting responses to light quality cues. A comparative RNA sequencing approach unveiled the molecular underpinnings of their contrasting growth responses to far-red light enrichment. It also identified differential phytochrome control of plant immunity genes and confirmed that far-red enrichment indeed contrastingly affects resistance against Botrytis cinerea between the two species. Furthermore, we identify a number of candidate regulators of differential shade avoidance. Three of these, the receptor-like kinases FERONIA and THESEUS1 and the non-DNA binding bHLH protein KIDARI, are functionally validated in Arabidopsis thaliana through gene knockout and/or overexpression studies. We propose that these components may be associated with either showing or not showing shade avoidance responses. PMID:28138015

  1. Molecular profiles of contrasting shade response strategies in wild plants: differential control of immunity and shoot elongation.

    PubMed

    Gommers, Charlotte M M; Keuskamp, Diederik H; Buti, Sara; Van Veen, Hans; Koevoets, Iko T; Reinen, Emilie; Voesenek, Laurentius A C J; Pierik, Ronald

    2017-01-30

    Plants growing at high densities elongate their shoots to reach for light, a response known as the shade avoidance syndrome (SAS). Phytochrome-mediated detection of far-red light reflection from neighbouring plants activates growth-promoting molecular pathways leading to SAS. It is however unknown how plants that complete their life cycle in the forest understory and are shade tolerant prevent SAS when exposed to shade. Here we show how two wild Geranium species from different native light environments regulate contrasting responses to light quality cues. A comparative RNA sequencing approach unveiled the molecular underpinnings of their contrasting growth responses to far-red light enrichment. It also identified differential phytochrome control of plant immunity genes and confirmed that far-red enrichment indeed contrastingly affects resistance against Botrytis cinerea between the two species. Furthermore, we identify a number of candidate regulators of differential shade avoidance. Three of these, the receptor-like kinases FERONIA and THESEUS1 and the non-DNA binding bHLH protein KIDARI, are functionally validated in Arabidopsis thaliana through gene knockout and/or overexpression studies. We propose that these components may be associated with either showing or not showing shade avoidance responses.

  2. Chronic Hepatitis C Virus Infection: A Review of Current Direct-Acting Antiviral Treatment Strategies

    PubMed Central

    Zhang, Johnathan; Nguyen, Douglas; Hu, Ke-Qin

    2016-01-01

    Chronic Hepatitis C virus (HCV) infection carries a significant clinical burden in the United States, affecting more than 4.6 million Americans. Untreated chronic HCV infection can result in cirrhosis, portal hypertension, and hepatocellular carcinoma. Previous interferon based treatment carried low rates of success and significant adverse effects. The advent of new generation oral antiviral therapy has led to major improvements in efficacy and tolerability but has also resulted in an explosion of data with increased treatment choice complexity. Treatment guidelines are constantly evolving due to emerging regimens and real world treatment data. There also still remain subpopulations for whom current treatments are lacking or unclearly defined. Thus, the race for development of HCV treatment regimens still continues. This review of the current literature will discuss the current recommended treatment strategies and briefly overview next generation agents. PMID:27293521

  3. Global burden of Shigella infections: implications for vaccine development and implementation of control strategies.

    PubMed Central

    Kotloff, K. L.; Winickoff, J. P.; Ivanoff, B.; Clemens, J. D.; Swerdlow, D. L.; Sansonetti, P. J.; Adak, G. K.; Levine, M. M.

    1999-01-01

    Few studies provide data on the global morbidity and mortality caused by infection with Shigella spp.; such estimates are needed, however, to plan strategies of prevention and treatment. Here we report the results of a review of the literature published between 1966 and 1997 on Shigella infection. The data obtained permit calculation of the number of cases of Shigella infection and the associated mortality occurring worldwide each year, by age, and (as a proxy for disease severity) by clinical category, i.e. mild cases remaining at home, moderate cases requiring outpatient care, and severe cases demanding hospitalization. A sensitivity analysis was performed to estimate the high and low range of morbid and fatal cases in each category. Finally, the frequency distribution of Shigella infection, by serogroup and serotype and by region of the world, was determined. The annual number of Shigella episodes throughout the world was estimated to be 164.7 million, of which 163.2 million were in developing countries (with 1.1 million deaths) and 1.5 million in industrialized countries. A total of 69% of all episodes and 61% of all deaths attributable to shigellosis involved children under 5 years of age. The median percentages of isolates of S. flexneri, S. sonnei, S. boydii, and S. dysenteriae were, respectively, 60%, 15%, 6%, and 6% (30% of S. dysenteriae cases were type 1) in developing countries; and 16%, 77%, 2%, and 1% in industrialized countries. In developing countries, the predominant serotype of S. flexneri is 2a, followed by 1b, 3a, 4a, and 6. In industrialized countries, most isolates are S. flexneri 2a or other unspecified type 2 strains. Shigellosis, which continues to have an important global impact, cannot be adequately controlled with the existing prevention and treatment measures. Innovative strategies, including development of vaccines against the most common serotypes, could provide substantial benefits. PMID:10516787

  4. Quantitative assessment of organizational culture within hospitals and its relevance to infection prevention and control strategies.

    PubMed

    Borg, M A; Waisfisz, B; Frank, U

    2015-05-01

    It has been suggested that organizational culture (OC) is an important driver of infection prevention and control (IPC) behaviour among healthcare workers. This study examined OC in seven European hospitals using a validated assessment tool based on Hofstede's model, and identified significant variations in OC scores. Hospitals with low prevalence of meticillin-resistant Staphylococcus aureus (MRSA) exhibited high scores for change facilitation and change readiness, whereas hospitals with high prevalence of MRSA exhibited low scores for these determinants. It is possible to use tools, available outside health care, to study OC within hospitals and gain better insight into IPC behaviour change strategies.

  5. Predictive models of control strategies involved in containing indoor airborne infections.

    PubMed

    Chen, S-C; Chang, C-F; Liao, C-M

    2006-12-01

    Recently developed control measure modeling approaches for containing airborne infections, including engineering controls with respiratory protection and public health interventions, are readily amenable to an integrated-scale analysis. Here we show that such models can be derived from an integrated-scale analysis generated from three different types of functional relationship: Wells-Riley mathematical model, competing-risks model, and Von Foerster equation, both of the key epidemiological determinants involved and of the functional connections between them. We examine mathematically the impact of engineering control measures such as enhanced air exchange and air filtration rates with personal masking combined with public health interventions such as vaccination, isolation, and contact tracing in containing the spread of indoor airborne infections including influenza, chickenpox, measles, and severe acute respiratory syndrome (SARS). If enhanced engineering controls could reduce the basic reproductive number (R0) below 1.60 for chickenpox and 3 for measles, our simulations show that in such a prepared response with public health interventions would have a high probability of containing the indoor airborne infections. Combinations of engineering control measures and public health interventions could moderately contain influenza strains with an R0 as high as 4. Our analysis indicates that effective isolation of symptomatic patients with low-efficacy contact tracing is sufficient to control a SARS outbreak. We suggest that a valuable added dimension to public health inventions could be provided by systematically quantifying transmissibility and proportion of asymptomatic infection of indoor airborne infection. Practical Implications We have developed a flexible mathematical model that can help determine the best intervention strategies for containing indoor airborne infections. The approach presented here is scalable and can be extended to include additional control

  6. Interferon response following infection with genetically similar isolates of viral haemorrhagic septicaemia virus (VHSV) exhibiting contrasting virulence in rainbow trout.

    PubMed

    Campbell, S; McBeath, A; Secombes, C; Snow, M; Collet, B

    2011-01-01

    Isolates of viral haemorrhagic septicaemia virus (VHSV) were identified which are genetically similar yet, based on their isolation history were considered likely to differ in virulence in juvenile rainbow trout. An experimental infection study was performed in order to verify this hypothesis and provide an experimental infectivity model with which to investigate the basis for susceptibility of rainbow trout to this commercially important virus. Significant differences in mortality were obtained following both intraperitoneal (IP) injection and immersion challenges with an early marine (DK-M.Rhabdo) and early rainbow trout VHSV isolate (DK-F1) respectively. Expression of Type I IFN, Mx1 (an IFN-inducible protein), and viral genes (encoding nucleo-, phospho-, matrix, glyco- and non-viron proteins) was studied in sequential tissue samples using real-time quantitative PCR (QPCR). Resulting data revealed a significant increase in IFN and Mx1 expression detected in fish challenged by IP injection with both isolates. Expression levels of these genes were directly related to the degree of viral replication as measured by the expression of VHSV RNAs. In immersion-challenged fish a significant increase in Mx1 was observed only when using the virulent isolate DK-F1; however no elevated host response was detectable in fish challenged with the marine isolate DK-M.Rhabdo. Quintessentially the inability to detect any virus in trout challenged with the marine isolate via immersion suggests the virus was incapable of establishing infection. The mechanisms for this appear to be more related to initial cellular entry and replication rather than due to the overcoming of initial infection via an elevated host innate immune response.

  7. Contrasting patterns in the small-scale heterogeneity of human helminth infections in urban and rural environments in Brazil.

    PubMed

    Brooker, Simon; Alexander, Neal; Geiger, Stefan; Moyeed, Rana A; Stander, Julian; Fleming, Fiona; Hotez, Peter J; Correa-Oliveira, Rodrigo; Bethony, Jeffrey

    2006-09-01

    Marked heterogeneity exists in the patterns of parasitic infection between individuals, households and communities. Analysis of parasite distributions within populations is complicated by the fact that parasite distributions are highly aggregated and few studies have explicitly incorporated this distribution when investigating small-scale spatial heterogeneities. This study aimed to quantify the small-scale (within- and between-household) heterogeneity of helminth infection in an area of Minas Gerais State, Brazil, with rural and urban sectors. Parasitological data from a cross-sectional survey of 1,249 individuals aged 0-86 years from 242 households were analysed. Within-household clustering of infection was assessed using random effect logistic regression models and between-household spatial heterogeneity was assessed using a Bayesian negative binomial spatial model. The overall prevalence of hookworm (Necator americanus) was 66.9%, the prevalence of Schistosoma mansoni was 44.9% and the prevalence of Ascaris lumbricoides was 48.8%. Statistical analysis indicated significant (within) household and (between household) spatial clustering of hookworm in both rural and urban areas and of S. mansoni in rural areas. There was no evidence of either household or spatial clustering of S. mansoni in urban areas. The spatial correlation of S. mansoni was estimated to reduce by half over a distance of 700 m in the rural area. Rural hookworm had a much smaller half-distance (28 m) and urban hookworm showed an even smaller half-distance (12 m). We suggest that such species-specific differences in patterns of infection by environment are primarily due to variation in exposure and parasite life cycle, although host genetic factors cannot be ruled out.

  8. Contrasting patterns in the small-scale heterogeneity of human helminth infections in urban and rural environments in Brazil

    PubMed Central

    Brooker, Simon; Alexander, Neal; Geiger, Stefan; Moyeed, Rana A; Stander, Julian; Fleming, Fiona; Hotez, Peter J; Correa-Oliveira, Rodrigo; Bethony, Jeffrey

    2006-01-01

    Marked heterogeneity exists in the patterns of parasitic infection between individuals, households and communities. Analysis of parasite distributions within populations is complicated by the fact that parasite distributions are highly aggregated, and few studies have explicitly incorporated this distribution when investigating small-scale spatial heterogeneities. This study aimed to quantify the small-scale (within and between household) heterogeneity of helminth infection in an area of Minas Gerais State, Brazil with rural and urban sectors. Parasitological data from a cross-sectional survey of 1,249 individuals aged 0-86 years from 242 households were analysed. Within household clustering of infection was assessed using random effect logistic regression models and between household spatial heterogeneity was assessed using a Bayesian negative binomial spatial model. The overall prevalence of hookworm (Necator americanus) was 66.9%, the prevalence of Schistosoma mansoni was 44.9%, and the prevalence of Ascaris lumbricoides was 48.8%. Statistical analysis indicated significant (within) household and (between household) spatial clustering of hookworm in both rural and urban areas and of S. mansoni in rural areas. There was no evidence of either household or spatial clustering of S. mansoni in urban areas. The spatial correlation of S. mansoni was estimated to reduce by half over a distance of 700m in the rural area. Rural hookworm had a much smaller half-distance and urban hookworm showed an even smaller half-distance (12m). We suggest that such species-specific differences in patterns of infection by environment are primarily due to variation in exposure and parasite life cycle, although host genetic factors cannot be ruled out. PMID:16814294

  9. Resistance and Susceptibility to Malarial Infection: A Host Defense Strategy against Malaria

    PubMed Central

    BAKIR, Hanaa; YONES, Doaa; GALAL, Lamia; HUSEEIN, Enas

    2015-01-01

    Background: In an effort to understand what limits the virulence of malaria parasites in relation to the host genetic and immunogenic background, we investigated the possibility that the parasite and host genotype crossover interactions constrain virulence. Methods: Two groups of mice from different genotypes were used (C57BL/6 (B6) and DBA/2 mice). The mice were infected with a virulent parasite line Plasmodium yoelii 17XL (P. yoelii 17XL). Parasitemia, hematocrit value and lymphocytes yielded by livers and spleens were evaluated. Fluorescence Activated Cell Sorting (FACS) analysis illustrated phenotypic characterization of lymphocytes. Results: Infection with P. yoelii 17XL did not result in the death of DBA/2 mice. In contrast, B6 mice developed significantly high parasitemia and succumbed to death. Using (FACS) analysis, DBA/2 mice were found to experience a marked expansion of interleukin (IL)-2Rβ+ CD3int cells and γδ T cells in the liver, especially in the recovery phase. The expansion of unconventional T cells (i.e. B220+ T cells) was also marked in DBA/2 mice. Conclusion: The outcome of murine malaria infections depends on the dynamic interplay between the immune-mediator and the genotype of the host. PMID:26811732

  10. [An ultrastructural study of the cervix epitelium infected with the human papillomavirus types 16 and 18 before and after treatment with contrasting thermo-laser therapy].

    PubMed

    Manykin, A A; Ezhov, V V; Belov, S V; Danileĭko, Iu K; Saliuk, V A; Dymkovets, V P; Gushchina, E A; Lisitsyn, F V

    2014-01-01

    The results of the ultrastructural study of the epithelium of the patient cervix infected by the human papillomavirus (HPV) types 16 and 18 before and after treatment by contrasting thermo-laser therapy (CTLT) are presented. It was shown in this work that 1.5 and 6 months after treatment HPV DNA was not detected in the biopsy and the smear of the cervix using the polymerase chain reaction (PCR). In the ultrathin sections, the structure of the epithelial cells from the biopsy after treatment corresponded to norm. There was effective elimination of HPV types 16 and 18 as Induces by CTLT method.

  11. Contrasting phenotypic plasticity in the photoprotective strategies of the invasive species Carpobrotus edulis and the coexisting native species Crithmum maritimum.

    PubMed

    Fenollosa, Erola; Munné-Bosch, Sergi; Pintó-Marijuan, Marta

    2017-01-05

    Photoprotective strategies vary greatly within the plant kingdom and reflect a plant's physiological status and capacity to cope with environment variations. The plasticity and intensity of these responses may determine plant success. Invasive species are reported to show increased vigor to displace native species. Describing the mechanisms that confer such vigor is essential to understanding the success of invasive species. We performed an experiment whereby two species were monitored: Carpobrotus edulis, an aggressive invasive species in the Mediterranean basin, and Crithmum maritimum, a coexisting native species in the Cap de Creus Natural Park (NE Spain). We analyzed their photoprotective responses to seasonal environmental dynamics by comparing the capacity of the invader to respond to the local environmental stresses throughout the year. Our study analyses ecophysiological markers and photoprotective strategies to gain an insight into the success of invaders. We found that both species showed completely different but effective photoprotective strategies: in summer, C. edulis took special advantage of the xanthophyll cycle, whereas the success of C. maritimum in summer stemmed from morphological changes and alterations on β-carotene content. Winter also presented differences between the species, as the native showed reduced Fv /Fm ratios. Our experimental design allowed us to introduce a new approach to compare phenotypic plasticity: the integrated phenotypic plasticity index (PPint ), defined as the maximum Euclidian distance between phenotypes, using a combination of different variables to describe them. This index revealed significantly greater phenotypic plasticity in the invasive species compared to the native species.

  12. Task-based strategy for optimized contrast enhanced breast imaging: Analysis of six imaging techniques for mammography and tomosynthesis

    SciTech Connect

    Ikejimba, Lynda C.; Kiarashi, Nooshin; Ghate, Sujata V.; Samei, Ehsan; Lo, Joseph Y.

    2014-06-15

    Purpose: The use of contrast agents in breast imaging has the capability of enhancing nodule detectability and providing physiological information. Accordingly, there has been a growing trend toward using iodine as a contrast medium in digital mammography (DM) and digital breast tomosynthesis (DBT). Widespread use raises concerns about the best way to use iodine in DM and DBT, and thus a comparison is necessary to evaluate typical iodine-enhanced imaging methods. This study used a task-based observer model to determine the optimal imaging approach by analyzing six imaging paradigms in terms of their ability to resolve iodine at a given dose: unsubtracted mammography and tomosynthesis, temporal subtraction mammography and tomosynthesis, and dual energy subtraction mammography and tomosynthesis. Methods: Imaging performance was characterized using a detectability index d{sup ′}, derived from the system task transfer function (TTF), an imaging task, iodine signal difference, and the noise power spectrum (NPS). The task modeled a 10 mm diameter lesion containing iodine concentrations between 2.1 mg/cc and 8.6 mg/cc. TTF was obtained using an edge phantom, and the NPS was measured over several exposure levels, energies, and target-filter combinations. Using a structured CIRS phantom, d{sup ′} was generated as a function of dose and iodine concentration. Results: For all iodine concentrations and dose, temporal subtraction techniques for mammography and tomosynthesis yielded the highest d{sup ′}, while dual energy techniques for both modalities demonstrated the next best performance. Unsubtracted imaging resulted in the lowest d{sup ′} values for both modalities, with unsubtracted mammography performing the worst out of all six paradigms. Conclusions: At any dose, temporal subtraction imaging provides the greatest detectability, with temporally subtracted DBT performing the highest. The authors attribute the successful performance to excellent cancellation of

  13. Task-based strategy for optimized contrast enhanced breast imaging: Analysis of six imaging techniques for mammography and tomosynthesis

    PubMed Central

    Ikejimba, Lynda C.; Kiarashi, Nooshin; Ghate, Sujata V.; Samei, Ehsan; Lo, Joseph Y.

    2014-01-01

    Purpose: The use of contrast agents in breast imaging has the capability of enhancing nodule detectability and providing physiological information. Accordingly, there has been a growing trend toward using iodine as a contrast medium in digital mammography (DM) and digital breast tomosynthesis (DBT). Widespread use raises concerns about the best way to use iodine in DM and DBT, and thus a comparison is necessary to evaluate typical iodine-enhanced imaging methods. This study used a task-based observer model to determine the optimal imaging approach by analyzing six imaging paradigms in terms of their ability to resolve iodine at a given dose: unsubtracted mammography and tomosynthesis, temporal subtraction mammography and tomosynthesis, and dual energy subtraction mammography and tomosynthesis. Methods: Imaging performance was characterized using a detectability index d′, derived from the system task transfer function (TTF), an imaging task, iodine signal difference, and the noise power spectrum (NPS). The task modeled a 10 mm diameter lesion containing iodine concentrations between 2.1 mg/cc and 8.6 mg/cc. TTF was obtained using an edge phantom, and the NPS was measured over several exposure levels, energies, and target-filter combinations. Using a structured CIRS phantom, d′ was generated as a function of dose and iodine concentration. Results: For all iodine concentrations and dose, temporal subtraction techniques for mammography and tomosynthesis yielded the highest d′, while dual energy techniques for both modalities demonstrated the next best performance. Unsubtracted imaging resulted in the lowest d′ values for both modalities, with unsubtracted mammography performing the worst out of all six paradigms. Conclusions: At any dose, temporal subtraction imaging provides the greatest detectability, with temporally subtracted DBT performing the highest. The authors attribute the successful performance to excellent cancellation of inplane structures and

  14. Strategies for controlling non-transmissible infection outbreaks using a large human movement data set.

    PubMed

    Hancock, Penelope A; Rehman, Yasmin; Hall, Ian M; Edeghere, Obaghe; Danon, Leon; House, Thomas A; Keeling, Matthew J

    2014-09-01

    Prediction and control of the spread of infectious disease in human populations benefits greatly from our growing capacity to quantify human movement behavior. Here we develop a mathematical model for non-transmissible infections contracted from a localized environmental source, informed by a detailed description of movement patterns of the population of Great Britain. The model is applied to outbreaks of Legionnaires' disease, a potentially life-threatening form of pneumonia caused by the bacteria Legionella pneumophilia. We use case-report data from three recent outbreaks that have occurred in Great Britain where the source has already been identified by public health agencies. We first demonstrate that the amount of individual-level heterogeneity incorporated in the movement data greatly influences our ability to predict the source location. The most accurate predictions were obtained using reported travel histories to describe movements of infected individuals, but using detailed simulation models to estimate movement patterns offers an effective fast alternative. Secondly, once the source is identified, we show that our model can be used to accurately determine the population likely to have been exposed to the pathogen, and hence predict the residential locations of infected individuals. The results give rise to an effective control strategy that can be implemented rapidly in response to an outbreak.

  15. [Strategies for preventing de novo hepatitis B infection after liver transplantation (II)].

    PubMed

    Fernández Castroagudín, Javier

    2014-07-01

    Although active immunization against the hepatitis B virus (HBV) through vaccination constitutes a fundamental strategy in the prevention of infection by this virus, it is not effective in isolation for preventing de novo HBV infections in recipients of liver grafts from core antigen antibody (anti-HBc) positive donors. In this situation, the risk of developing de novo hepatitis B depends on the recipient's serological status. It has been shown that, for vaccinated patients and in the absence of prophylaxis with nucleoside/nucleotide analogues and/or hyperimmune gamma globulin, the prevalence and cumulative incidence of HBV infection after transplantation is an intermediate risk. The absence of a surface antigen antibody (anti-HBs) titer cutoff considered protective, the gradual reduction of these titers after vaccination, the presence of false positives for anti-HBs in patients undergoing infusion of blood products and escape mutations of the hepatitis B surface antigen (HBsAg) could explain this lack of efficacy. For this reason, it is recommended that vaccination protocols be implemented universally, along with the follow-up of the level of protection in patients with cirrhosis, adding prophylaxis with analogues when receiving a graft from an anti-HBc-positive donor. Clinical and serological surveillance alone can be considered for patients with anti-HBs levels greater than 200 mUI/mL after vaccination.

  16. Strategies for Controlling Non-Transmissible Infection Outbreaks Using a Large Human Movement Data Set

    PubMed Central

    Hancock, Penelope A.; Rehman, Yasmin; Hall, Ian M.; Edeghere, Obaghe; Danon, Leon; House, Thomas A.; Keeling, Matthew J.

    2014-01-01

    Prediction and control of the spread of infectious disease in human populations benefits greatly from our growing capacity to quantify human movement behavior. Here we develop a mathematical model for non-transmissible infections contracted from a localized environmental source, informed by a detailed description of movement patterns of the population of Great Britain. The model is applied to outbreaks of Legionnaires' disease, a potentially life-threatening form of pneumonia caused by the bacteria Legionella pneumophilia. We use case-report data from three recent outbreaks that have occurred in Great Britain where the source has already been identified by public health agencies. We first demonstrate that the amount of individual-level heterogeneity incorporated in the movement data greatly influences our ability to predict the source location. The most accurate predictions were obtained using reported travel histories to describe movements of infected individuals, but using detailed simulation models to estimate movement patterns offers an effective fast alternative. Secondly, once the source is identified, we show that our model can be used to accurately determine the population likely to have been exposed to the pathogen, and hence predict the residential locations of infected individuals. The results give rise to an effective control strategy that can be implemented rapidly in response to an outbreak. PMID:25211122

  17. Transcriptional and Metabolic Changes Associated to the Infection by Fusarium verticillioides in Maize Inbreds with Contrasting Ear Rot Resistance

    PubMed Central

    Campos-Bermudez, Valeria A.; Fauguel, Carolina M.; Tronconi, Marcos A.; Casati, Paula; Presello, Daniel A.; Andreo, Carlos S.

    2013-01-01

    Fusarium verticillioides causes ear rot and grain mycotoxins in maize (Zea mays L.), which are harmful to human and animal health. Breeding and growing less susceptible plant genotypes is one alternative to reduce these detrimental effects. A better understanding of the resistance mechanisms would facilitate the implementation of strategic molecular agriculture to breeding of resistant germplasm. Our aim was to identify genes and metabolites that may be related to the Fusarium reaction in a resistant (L4637) and a susceptible (L4674) inbred. Gene expression data were obtained from microarray hybridizations in inoculated and non-inoculated kernels from both inbreds. Fungal inoculation did not produce considerable changes in gene expression and metabolites in L4637. Defense-related genes changed in L4674 kernels, responding specifically to the pathogen infection. These results indicate that L4637 resistance may be mainly due to constitutive defense mechanisms preventing fungal infection. These mechanisms seem to be poorly expressed in L4674; and despite the inoculation activate a defense response; this is not enough to prevent the disease progress in this susceptible line. Through this study, a global view of differential genes expressed and metabolites accumulated during resistance and susceptibility to F. verticillioides inoculation has been obtained, giving additional information about the mechanisms and pathways conferring resistance to this important disease in maize. PMID:23637860

  18. NOD1 in contrast to NOD2 functional polymorphism influence Chlamydia trachomatis infection and the risk of tubal factor infertility

    PubMed Central

    Branković, Ivan; van Ess, Eleanne F.; Noz, Marlies P.; Wiericx, Wilhelmina (Anke) J.; Spaargaren, Joke; Morré, Servaas A.; Ouburg, Sander

    2015-01-01

    Intracellular pattern-recognition receptors NOD1 and NOD2 are capable of sensing common structural units of bacterial walls. Recognition triggers specific immune signalling pathways and leads to pro-inflammatory cytokine upregulation and adequate immune response. We investigated whether two functional polymorphisms in NOD1 and NOD2 exert an effect on susceptibility to (STD patients) and severity of (female patients visiting the fertility clinic) Chlamydia trachomatis infection in 807 Dutch Caucasian women. A significant association of the NOD1 +32656 GG insertion variant with protection against infection with C. trachomatis has been detected [p: 0.0057; OR: 0.52]. When comparing C. trachomatis-positive women without symptoms to C. trachomatis-positive women with symptoms, and to C. trachomatis-positive women with TFI, we observed an increasing trend in carriage of the GG allele [Ptrend: 0.0003]. NOD2 1007fs failed to reveal an association. We hypothesize that the underlying mechanism might be a functional effect of the GG insertion on IFN-beta-dependent regulation of immune response in the genital tract. The research is part of an ongoing effort of identifying key polymorphisms that determine the risk of TFI and effectively translating them into the clinical setting for the purpose of optimizing diagnostic management of women at risk for developing TFI. PMID:25854006

  19. Is closure of entire wards necessary to control norovirus outbreaks in hospital? Comparing the effectiveness of two infection control strategies.

    PubMed

    Illingworth, E; Taborn, E; Fielding, D; Cheesbrough, J; Diggle, P J; Orr, D

    2011-09-01

    The standard approach for norovirus control in hospitals in the UK, as outlined by the Health Protection Agency guidance and implemented previously by Lancashire Teaching Hospitals, involves the early closure of affected wards. However, this has a major impact on bed-days lost and cancelled admissions. In 2008, a new strategy was introduced in the study hospital, key elements of which included closure of affected ward bays (rather than wards), installation of bay doors, enhanced cleaning, a rapid in-house molecular test and an enlarged infection control team. The impact of these changes was assessed by comparing two norovirus seasons (2007-08 and 2009-10) before and after implementation of the new strategy, expressing the contrast between seasons as a ratio (r) of expected counts in the two seasons. There was a significant decrease in the ratio of confirmed hospital outbreaks to community outbreaks (r = 0.317, P = 0.025), the number of days of restricted admissions on hospital wards per outbreak (r = 0.742, P = 0.041), and the number of hospital bed-days lost per outbreak (r = 0.344, P <0.001). However, there was no significant change in the number of patients affected per hospital outbreak (r = 1.080, P = 0.517), or the number of hospital staff affected per outbreak (r = 0.651, P = 0.105). Closure of entire wards during norovirus outbreaks is not always necessary. The changes implemented at the study hospital resulted in a significant reduction in the number of bed-days lost per outbreak, and this, together with a reduction in outbreak frequency, resulted in considerable cost savings.

  20. Contrasting behavioral and feeding strategies recorded by tidal-flat bivalve trace fossils from the Upper Carboniferous of eastern Kansas

    USGS Publications Warehouse

    Mangano, M.G.; Buatois, L.A.; West, R.R.; Maples, C.G.

    1998-01-01

    Upper Carboniferous tidal-flat deposits near Waverly, eastern Kansas (Stull Shale Member, Kanwaka Shale Formation), host abundant and very well-preserved trace fossils attributed to the activity of burrowing bivalves. Thin shell lenses with an abundant bivalve fauna area associated with the ichnofossil-bearing beds and afford an unusual opportunity to relate trace fossils to their makers. Two distinctive life and feeding strategies can be reconstructed on the basis of trace fossil analysis and functional morphology. Lockeria siliquaria hyporeliefs commonly are connected with vertical to inclined, truncated endichnial shafts in the absence of horizontal locomotion traces. These structures record vertical and oblique displacement through the sediment, and suggest relatively stable domiciles rather than temporary resting traces as typically considered. Crowded bedding surfaces displaying cross-cutting relationships between specimens of L. siliquaria and differential preservation at the top (concave versus convex epireliefs) record a complex history of successive events of colonization, erosion, deposition, and recolonization (time-averaged assemblages). Irregujlar contours of some large hypichnia indicate the cast of the foot, while other outlines closely match the anterior area of Wilkingia, its suggested tracemaker. Relatively stable, vertical to inclined life positions and dominanit vertical mobility suggest a filter-feeding strategy. Moreover, the elongate shell and pallial sinus of Wilkingia providfe a strong independent line of evidence for an opisthosiphonate, moderately deep-tier inhabitant. Wilingia may represent a pioneer attempt at siphon-feeding in the late Paleozoic, preceding the outcome of the Mesozoic infaunal radiation. A second strategy is represented by Lockeia ornata and association locomotionm and locomotion/feding structures. Lockeia ornata is commonly connected with chevron locomotion traces that record the bifurcated foot of a protobranch

  1. Alterations in Kernel Proteome after Infection with Fusarium culmorum in Two Triticale Cultivars with Contrasting Resistance to Fusarium Head Blight

    PubMed Central

    Perlikowski, Dawid; Wiśniewska, Halina; Kaczmarek, Joanna; Góral, Tomasz; Ochodzki, Piotr; Kwiatek, Michał; Majka, Maciej; Augustyniak, Adam; Kosmala, Arkadiusz

    2016-01-01

    Highlight: The level of pathogen alpha-amylase and plant beta-amylase activities could be components of plant-pathogen interaction associated with the resistance of triticale to Fusarium head blight. Triticale was used here as a model to recognize new components of molecular mechanism of resistance to Fusarium head blight (FHB) in cereals. Fusarium-damaged kernels (FDK) of two lines distinct in levels of resistance to FHB were applied into a proteome profiling using two-dimensional gel electrophoresis (2-DE) to create protein maps and mass spectrometry (MS) to identify the proteins differentially accumulated between the analyzed lines. This proteomic research was supported by a measurement of alpha- and beta-amylase activities, mycotoxin content, and fungal biomass in the analyzed kernels. The 2-DE analysis indicated a total of 23 spots with clear differences in a protein content between the more resistant and more susceptible triticale lines after infection with Fusarium culmorum. A majority of the proteins were involved in a cell carbohydrate metabolism, stressing the importance of this protein group in a plant response to Fusarium infection. The increased accumulation levels of different isoforms of plant beta-amylase were observed for a more susceptible triticale line after inoculation but these were not supported by a total level of beta-amylase activity, showing the highest value in the control conditions. The more resistant line was characterized by a higher abundance of alpha-amylase inhibitor CM2 subunit and simultaneously a lower activity of alpha-amylase after inoculation. We suggest that the level of pathogen alpha-amylase and plant beta-amylase activities could be components of plant-pathogen interaction associated with the resistance of triticale to FHB. PMID:27582751

  2. Deuterium Labeling Strategies for Creating Contrast in Structure-Function Studies of Model Bacterial Outer Membranes Using Neutron Reflectometry.

    PubMed

    Le Brun, Anton P; Clifton, Luke A; Holt, Stephen A; Holden, Peter J; Lakey, Jeremy H

    2016-01-01

    Studying the outer membrane of Gram-negative bacteria is challenging due to the complex nature of its structure. Therefore, simplified models are required to undertake structure-function studies of processes that occur at the outer membrane/fluid interface. Model membranes can be created by immobilizing bilayers to solid supports such as gold or silicon surfaces, or as monolayers on a liquid support where the surface pressure and fluidity of the lipids can be controlled. Both model systems are amenable to having their structure probed by neutron reflectometry, a technique that provides a one-dimensional depth profile through a membrane detailing its thickness and composition. One of the strengths of neutron scattering is the ability to use contrast matching, allowing molecules containing hydrogen and those enriched with deuterium to be highlighted or matched out against the bulk isotopic composition of the solvent. Lipopolysaccharides, a major component of the outer membrane, can be isolated for incorporation into model membranes. Here, we describe the deuteration of lipopolysaccharides from rough strains of Escherichia coli for incorporation into model outer membranes, and how the use of deuterated materials enhances structural analysis of model membranes by neutron reflectometry.

  3. Root foraging for Patchy Phosphorus of Plant Species with Contrasting Foraging Strategy - Role of Roots and Mycorrhiza

    NASA Astrophysics Data System (ADS)

    Felderer, B.; Robinson, B. H.; Jansa, J.; Vontobel, P.; Frossard, E.; Schulin, R.

    2009-04-01

    Plant nutrients are distributed heterogeneously in soil. Thus the nutrient distribution together with nutrient availability, temporal and spatial development of roots determine nutrient uptake by the plants. Plants have developed several strategies to cope with the patchy nutrient distribution. Preferential root development within nutrient-enriched patches is a prominent response to heterogeneous nutrient distribution. This capacity to precisely allocate roots is called morphological plasticity and is highly variable between plant species. Another strategy is the increased nutrient uptake per unit of root surface in the nutrient-rich patches as compared to root zones outside such patches, so-called physiological plasticity . Additionally, enhanced nutrient uptake from nutrient-rich patches might be supported by increased production of mycorrhizal extraradical hyphae. We refer to this phenomenon as plastic response of the mycorrhiza-plant association. Relative importance for nutrient acquisition of these responses to heterogeneous nutrient distribution might vary between plant species. However, quantitative data are very rare. We will investigate nutrient acquisition and root development over time in sandy substrate with heterogeneous phosphorus (P) distribution of two model plant species with different nutrient foraging strategies (Lotus corniculatus, Trifolium arvense). These plant species are characterized by high and low morphological plasticity, respectively (according to results of preliminary experiments). We follow three main goals in a single mesocosm experiment, where P is to be homogeneously or patchily distributed in a sandy substrate: 1. - Imaging of root architecture of Lotus corniculatus and Trifolium arvense on a time line. 2. - Assessment of the physiological plasticity of Lotus corniculatus and Trifolium arvense 3. - Determination of the plasticity of mycorrhiza-plant association of Lotus corniculatus and Trifolium arvense associated with either of

  4. Antimicrobial and host-defense peptides as new anti-infective therapeutic strategies.

    PubMed

    Hancock, Robert E W; Sahl, Hans-Georg

    2006-12-01

    Short cationic amphiphilic peptides with antimicrobial and/or immunomodulatory activities are present in virtually every life form, as an important component of (innate) immune defenses. These host-defense peptides provide a template for two separate classes of antimicrobial drugs. Direct-acting antimicrobial host-defense peptides can be rapid-acting and potent, and possess an unusually broad spectrum of activity; consequently, they have prospects as new antibiotics, although clinical trials to date have shown efficacy only as topical agents. But for these compounds to fulfill their therapeutic promise and overcome clinical setbacks, further work is needed to understand their mechanisms of action and reduce the potential for unwanted toxicity, to make them more resistant to protease degradation and improve serum half-life, as well as to devise means of manufacturing them on a large scale in a consistent and cost-effective manner. In contrast, the role of cationic host-defense peptides in modulating the innate immune response and boosting infection-resolving immunity while dampening potentially harmful pro-inflammatory (septic) responses gives these peptides the potential to become an entirely new therapeutic approach against bacterial infections.

  5. Responses of serpentine plants to pine invasion: Vegetation diversity and nickel accumulation in species with contrasting adaptive strategies.

    PubMed

    Selvi, Federico; Carrari, Elisa; Colzi, Ilaria; Coppi, Andrea; Gonnelli, Cristina

    2017-04-01

    Introduction of non-native trees is one of the major threats to ecosystem integrity and biodiversity. Stands of maritime pine (Pinus pinaster Ait.) introduced decades ago represent a threat to the specialized plant communities of serpentine outcrops in Italy. This study investigates the effects of such invasions at the community and species level, based on vegetation sampling in three selected sites with comparable environmental conditions. Pine cover caused a decrease of α-diversity by lowering the species evenness of the community, though species richness was not negatively affected. Compositional changes between the two habitats were significant but not clearly associated with a decrease in taxonomic distinctness in the pine stands. As many as nine indicator species were found in the open vegetation, along with the obligate endemics Odontarrhena bertolonii and Armeria denticulata. Both of them declined in the pine stands. Here, an increase in the phytoavailable nickel fraction was associated with a decrease in total nickel concentration in the soil, via mobilization of the metal caused by lowering of pH induced by the conifer litter. The nickel-hyperaccumulator O. bertolonii was able to maintain high metal concentrations in the shoots despite a decrease in root concentration, resulting in a higher shoot/root ratio in the pine stands (~20). Conversely, shoot/root ratio in the non-accumulator Plantago holosteum was <1 and not affected by the conifer, as well as its abundance in this anthropogenic habitat. Contrasting responses of the two species were likely due to their different sensitivity to modified light and soil conditions, whereas stability of shoot nickel-concentration in O. bertolonii did not support increased predation by natural enemies as one of the causes for its decline under the conifer. Progressive thinning of these stands is advocated to limit soil nickel mobilization and to restore a unique ecosystem with its endemic metallophytes.

  6. Increase of Transmitted Drug Resistance among HIV-Infected Sub-Saharan Africans Residing in Spain in Contrast to the Native Population

    PubMed Central

    Yebra, Gonzalo; de Mulder, Miguel; Pérez-Elías, María Jesús; Pérez-Molina, José Antonio; Galán, Juan Carlos; Llenas-García, Jara; Moreno, Santiago; Holguín, África

    2011-01-01

    Background The prevalence of transmitted HIV drug resistance (TDR) is stabilizing or decreasing in developed countries. However, this trend is not specifically evaluated among immigrants from regions without well-implemented antiretroviral strategies. Methods TDR trends during 1996–2010 were analyzed among naïve HIV-infected patients in Spain, considering their origin and other factors. TDR mutations were defined according to the World Health Organization list. Results Pol sequence was available for 732 HIV-infected patients: 292 native Spanish, 226 sub-Saharan Africans (SSA), 114 Central-South Americans (CSA) and 100 from other regions. Global TDR prevalence was 9.7% (10.6% for Spanish, 8.4% for SSA and 7.9% for CSA). The highest prevalences were found for protease inhibitors (PI) in Spanish (3.1%), for non-nucleoside reverse transcriptase inhibitors (NNRTI) in SSA (6.5%) and for nucleoside reverse transcriptase inhibitors (NRTI) in both Spanish and SSA (6.5%). The global TDR rate decreased from 11.3% in 2004–2006 to 8.4% in 2007–2010. Characteristics related to a decreasing TDR trend in 2007-10 were Spanish and CSA origin, NRTI- and NNRTI-resistance, HIV-1 subtype B, male sex and infection through injection drug use. TDR remained stable for PI-resistance, in patients infected through sexual intercourse and in those carrying non-B variants. However, TDR increased among SSA and females. K103N was the predominant mutation in all groups and periods. Conclusion TDR prevalence tended to decrease among HIV-infected native Spanish and Central-South Americans, but it increased up to 13% in sub-Saharan immigrants in 2007–2010. These results highlight the importance of a specific TDR surveillance among immigrants to prevent future therapeutic failures, especially when administering NNRTIs. PMID:22046345

  7. Tailored enrichment strategy detects low abundant small noncoding RNAs in HIV-1 infected cells

    PubMed Central

    2012-01-01

    Background The various classes of small noncoding RNAs (sncRNAs) are important regulators of gene expression across divergent types of organisms. While a rapidly increasing number of sncRNAs has been identified over recent years, the isolation of sncRNAs of low abundance remains challenging. Virally encoded sncRNAs, particularly those of RNA viruses, can be expressed at very low levels. This is best illustrated by HIV-1 where virus encoded sncRNAs represent approximately 0.1-1.0% of all sncRNAs in HIV-1 infected cells or were found to be undetected. Thus, we applied a novel, sequence targeted enrichment strategy to capture HIV-1 derived sncRNAs in HIV-1 infected primary CD4+ T-lymphocytes and macrophages that allows a greater than 100-fold enrichment of low abundant sncRNAs. Results Eight hundred and ninety-two individual HIV-1 sncRNAs were cloned and sequenced from nine different sncRNA libraries derived from five independent experiments. These clones represent up to 90% of all sncRNA clones in the generated libraries. Two hundred and sixteen HIV-1 sncRNAs were distinguishable as unique clones. They are spread throughout the HIV-1 genome, however, forming certain clusters, and almost 10% show an antisense orientation. The length of HIV-1 sncRNAs varies between 16 and 89 nucleotides with an unexpected peak at 31 to 50 nucleotides, thus, longer than cellular microRNAs or short-interfering RNAs (siRNAs). Exemplary HIV-1 sncRNAs were also generated in cells infected with different primary HIV-1 isolates and can inhibit HIV-1 replication. Conclusions HIV-1 infected cells generate virally encoded sncRNAs, which might play a role in the HIV-1 life cycle. Furthermore, the enormous capacity to enrich low abundance sncRNAs in a sequence specific manner highly recommends our selection strategy for any type of investigation where origin or target sequences of the sought-after sncRNAs are known. PMID:22458358

  8. C3 and C4 biomass allocation responses to elevated CO2 and nitrogen: contrasting resource capture strategies

    USGS Publications Warehouse

    White, K.P.; Langley, J.A.; Cahoon, D.R.; Megonigal, J.P.

    2012-01-01

    Plants alter biomass allocation to optimize resource capture. Plant strategy for resource capture may have important implications in intertidal marshes, where soil nitrogen (N) levels and atmospheric carbon dioxide (CO2) are changing. We conducted a factorial manipulation of atmospheric CO2 (ambient and ambient + 340 ppm) and soil N (ambient and ambient + 25 g m-2 year-1) in an intertidal marsh composed of common North Atlantic C3 and C4 species. Estimation of C3 stem turnover was used to adjust aboveground C3 productivity, and fine root productivity was partitioned into C3-C4 functional groups by isotopic analysis. The results suggest that the plants follow resource capture theory. The C3 species increased aboveground productivity under the added N and elevated CO2 treatment (P 2 alone. C3 fine root production decreased with added N (P 2 (P = 0.0481). The C4 species increased growth under high N availability both above- and belowground, but that stimulation was diminished under elevated CO2. The results suggest that the marsh vegetation allocates biomass according to resource capture at the individual plant level rather than for optimal ecosystem viability in regards to biomass influence over the processes that maintain soil surface elevation in equilibrium with sea level.

  9. Carbon source-sink limitations differ between two species with contrasting growth strategies: Source-sink limitations vary with growth strategy

    DOE PAGES

    Burnett, Angela C.; Rogers, A.; Rees, M.; ...

    2016-09-22

    When we understand how carbon source and sink strengths limit plant growth we realized how critical the knowledge gap is in hindering efforts to maximize crop yield. Here, we investigated how differences in growth rate arise from source–sink limitations, using a model system comparing a fast-growing domesticated annual barley (Hordeum vulgare cv. NFC Tipple) with a slow-growing wild perennial relative (Hordeum bulbosum). Source strength was manipulated by growing plants at sub-ambient and elevated CO2 concentrations ([CO2]). Limitations on vegetative growth imposed by source and sink were diagnosed by measuring relative growth rate, developmental plasticity, photosynthesis and major carbon and nitrogenmore » metabolite pools. Growth was sink limited in the annual but source limited in the perennial. RGR and carbon acquisition were higher in the annual, but photosynthesis responded weakly to elevated [CO2] indicating that source strength was near maximal at current [CO2]. In contrast, photosynthetic rate and sink development responded strongly to elevated [CO2] in the perennial, indicating significant source limitation. Sink limitation was avoided in the perennial by high sink plasticity: a marked increase in tillering and root:shoot ratio at elevated [CO2], and lower non-structural carbohydrate accumulation. Finally, by alleviating sink limitation during vegetative development could be important for maximizing growth of elite cereals under future elevated [CO2].« less

  10. Carbon source-sink limitations differ between two species with contrasting growth strategies: Source-sink limitations vary with growth strategy

    SciTech Connect

    Burnett, Angela C.; Rogers, A.; Rees, M.; Osborne, Colin P.

    2016-09-22

    When we understand how carbon source and sink strengths limit plant growth we realized how critical the knowledge gap is in hindering efforts to maximize crop yield. Here, we investigated how differences in growth rate arise from source–sink limitations, using a model system comparing a fast-growing domesticated annual barley (Hordeum vulgare cv. NFC Tipple) with a slow-growing wild perennial relative (Hordeum bulbosum). Source strength was manipulated by growing plants at sub-ambient and elevated CO2 concentrations ([CO2]). Limitations on vegetative growth imposed by source and sink were diagnosed by measuring relative growth rate, developmental plasticity, photosynthesis and major carbon and nitrogen metabolite pools. Growth was sink limited in the annual but source limited in the perennial. RGR and carbon acquisition were higher in the annual, but photosynthesis responded weakly to elevated [CO2] indicating that source strength was near maximal at current [CO2]. In contrast, photosynthetic rate and sink development responded strongly to elevated [CO2] in the perennial, indicating significant source limitation. Sink limitation was avoided in the perennial by high sink plasticity: a marked increase in tillering and root:shoot ratio at elevated [CO2], and lower non-structural carbohydrate accumulation. Finally, by alleviating sink limitation during vegetative development could be important for maximizing growth of elite cereals under future elevated [CO2].

  11. Contrasting reproductive strategies in three deep-sea octocorals from eastern Canada: Primnoa resedaeformis, Keratoisis ornata, and Anthomastus grandiflorus

    NASA Astrophysics Data System (ADS)

    Mercier, A.; Hamel, J.-F.

    2011-06-01

    Various aspects of reproduction were studied in three deep-sea octocorals belonging to the order Alcyonacea that co-occur at bathyal depths on the continental edge and the slope of eastern Canada. The main goals were to expand knowledge of deep-water heterotrophic corals and ascertain whether reproductive strategies could explain the known patterns of occurrence. Anthomastus grandiflorus is a gonochoric species with a female-biased sex ratio that exhibits internal fertilization and brooding of planula larvae. Conversely, Primnoa resedaeformis and Keratoisis ornata rely on broadcast spawning and external fertilization; their sexuality remains undetermined as spermatocysts were not found. In P. resedaeformis, the presence of mixed size classes of oocytes in samples from all months, depths, and locations studied suggests continuous oogenesis or overlapping development of oocyte cohorts, indicative of a gametogenic cycle spanning more than a year. No evidence of periodicity was found in this species, although it could have been masked by the striking bathymetric variation in potential relative fecundity (oocytes polyp-1). The two other octocorals displayed a clear annual breeding pattern. Spawning in K. ornata and larval release in A. grandiflorus occurred in late summer and fall, respectively, possibly in response to environmental factors, as supported by shifts in the reproductive peak of A. grandiflorus across latitudes. The three species are presumed to share a nonfeeding larval mode, and data on their reproductive potential do not present any striking disparities. Published data on bycatches and video surveys in Atlantic Canada indicate that the gonochoric brooder A. grandiflorus is more widely distributed than the two free spawners, P. resedaeformis and K. ornata, which is contrary to common dispersal potential paradigms.

  12. Can Soil Seed Banks Serve as Genetic Memory? A Study of Three Species with Contrasting Life History Strategies

    PubMed Central

    Mandák, Bohumil; Zákravský, Petr; Mahelka, Václav; Plačková, Ivana

    2012-01-01

    We attempted to confirm that seed banks can be viewed as an important genetic reservoir by testing the hypothesis that standing (aboveground) plants represent a nonrandom sample of the seed bank. We sampled multilocus allozyme genotypes from three species with different life history strategies: Amaranthus retroflexus, Carduus acanthoides, Pastinaca sativa. In four populations of each species we analysed the extent to which allele and genotype frequencies vary in consecutive life history stages including the summer seed bank, which has been overlooked up to now. We compared the winter seed bank (i.e., seeds collected before the spring germination peak), seedlings, rosettes, the summer seed bank (i.e., seeds collected after the spring germination peak) and fruiting plants. We found that: (1) All three species partitioned most of their genetic diversity within life history stages and less among stages within populations and among populations. (2) All genetic diversity parameters, except for allele frequencies, were similar among all life history stages across all populations in different species. (3) There were differences in allele frequencies among life history stages at all localities in Amaranthus retroflexus and at three localities in both Carduus acanthoides and Pastinaca sativa. (4) Allele frequencies did not differ between the winter and summer seed bank in most Carduus acanthoides and Pastinaca sativa populations, but there was a marked difference in Amaranthus retroflexus. In conclusion, we have shown that the summer seed bank is not genetically depleted by spring germination and that a majority of genetic diversity remains in the soil through summer. We suggest that seed banks in the species investigated play an important role by maintaining genetic diversity sufficient for recovery rather than by accumulating new genetic diversity at each locality. PMID:23185340

  13. Dynamics of defense-related components in two contrasting genotypes of tomato upon infection with Tomato Leaf Curl New Delhi Virus.

    PubMed

    Sahu, Pranav Pankaj; Rai, Neeraj Kumar; Puranik, Swati; Roy, Anirban; Khan, Moinuddin; Prasad, Manoj

    2012-10-01

    Tomato leaf curl virus (ToLCV) disease is a serious threat for tomato cultivation in the tropics and subtropics. Despite serious efforts no immune commercial varieties or F(1) hybrids are available till date. In this study, the interaction between Solanum lycopersicum and ToLCV was characterized on molecular and biochemical basis. RNA silencing mediated by short interfering RNA (siRNA) and reactive oxygen species (ROS) has been proposed as central components of plant adaptation to several stresses. A comparative RNA interference study between two contrasting tomato genotypes, LA1777 (tolerant) and 15SBSB (susceptible) infected with Tomato Leaf Curl New Delhi Virus (ToLCNDV) revealed relatively higher accumulation of siRNA in the leaves of tolerant genotype. In LA1777, ToLCNDV produced chlorotic as well as necrotic areas at the inoculation sites 5-10 days post-inoculation. Caspase-9- and caspase-3-like activities were significantly increased in response to ToLCNDV infection in LA1777 at inoculated region. Activities of antioxidant enzymes involved in the detoxification of ROS were examined in both systemic and localized area of infection, and their expression level was further validated through quantitative real-time PCR of the corresponding transcripts. Expression patterns of three genes encoding pathogenesis-related proteins showed higher accumulation in tolerant genotype. Tolerance against the ToLCNDV in LA1777 can be attributed to the higher siRNA accumulation, localized cell death, altered levels of antioxidant enzymes and activation of pathogenesis-related genes at different durations of virus infection. Based on these direct and indirect evidences, we have proposed a putative mechanism for ToLCNDV tolerance in the tolerant genotype.

  14. Pathogenesis of and strategies for preventing Edwardsiella tarda infection in fish

    PubMed Central

    2012-01-01

    Edwardsiella tarda is one of the serious fish pathogens, infecting both cultured and wild fish species. Research on edwardsiellosis has revealed that E. tarda has a broad host range and geographic distribution, and contains important virulence factors that enhance bacterial survival and pathogenesis in hosts. Although recent progress in edwardsiellosis research has enabled the development of numerous, highly effective vaccine candidates, these efforts have not been translated into a commercialized vaccine. The present review aims to provide an overview of the identification, pathology, diagnosis and virulence factors of E. tarda in fish, and describe recent strategies for developing vaccines against edwardsiellosis. The hope is that this presentation will be useful not only from the standpoint of understanding the pathogenesis of E. tarda, but also from the perspective of facilitating the development of effective vaccines. PMID:23035843

  15. Immunological efficacy of pneumococcal vaccine strategies in HIV-infected adults: a randomized clinical trial.

    PubMed

    Sadlier, C; O'Dea, S; Bennett, K; Dunne, J; Conlon, N; Bergin, C

    2016-09-01

    The aim of this study was to compare the immunologic response to a prime-boost immunization strategy combining the 13-valent conjugate pneumococcal vaccine (PCV13) with the 23-valent polysaccharide pneumococcal vaccine (PPSV23) versus the PPSV23 alone in HIV-infected adults. HIV-infected adults were randomized to receive PCV13 at week 0 followed by PPSV23 at week 4 (n = 31, prime-boost group) or PPSV23 alone at week 4 (n = 33, PPSV23-alone group). Serotype specific IgG geometric mean concentration (GMC) and functional oposonophagocytic (OPA) geometric mean titer (GMT) were compared for 12 pneumococcal serotypes shared by both vaccines at week 8 and week 28. The prime-boost vaccine group were more likely to achieve a ≥2-fold increase in IgG GMC and a GMC >1 ug/ml at week 8 (odds ratio (OR) 2.00, 95% confidence interval (CI) 1.46-2.74, p < 0.01) and week 28 (OR 1.95, 95% CI 1.40-2.70, p < 0.01). Similarly, the prime-boost vaccine group were more likely to achieve a ≥4-fold increase in GMT at week 8 (OR 1.71, 95% CI 1.22-2.39, p < 0.01) and week 28 (OR 1.6, 95% CI 1.15-2.3, p < 0.01). This study adds to evidence supporting current pneumococcal vaccination recommendations combining the conjugate and polysaccharide pneumococcal vaccines in the United States and Europe for HIV-infected individuals.

  16. Optimizing Antibiotic Dosing Strategies for the Treatment of Gram-negative Infections in the Era of Resistance.

    PubMed

    Monogue, Marguerite L; Kuti, Joseph L; Nicolau, David P

    2016-01-01

    Gram-negative organisms are an increasing source of concern within the healthcare setting due to their common presence as a cause of infection and emerging resistance to current therapies. However, current antimicrobial dosing recommendations may be insufficient for the treatment of gram-negative infections. Applying knowledge of an antibiotic's pharmacokinetic/pharmacodynamic profile when designing a dosing regimen leads to a greater likelihood of achieving optimal exposure, including against gram-negative pathogens with higher MICs. Additionally, administering antibiotics directly to the site of infection, such as via aerosolization for pneumonia, is another method to achieve optimized drug exposure at the site of infection. Incorporating these treatment strategies into clinical practice will assist antimicrobial stewardship programs in successfully treating gram-negative infections.

  17. Diagnostic strategy and timing of intervention in infected necrotizing pancreatitis: an international expert survey and case vignette study

    PubMed Central

    van Grinsven, Janneke; van Brunschot, Sandra; Bakker, Olaf J.; Bollen, Thomas L.; Boermeester, Marja A.; Bruno, Marco J.; Dejong, Cornelis H.; Dijkgraaf, Marcel G.; van Eijck, Casper H.; Fockens, Paul; van Goor, Harry; Gooszen, Hein G.; Horvath, Karen D.; van Lienden, Krijn P.; van Santvoort, Hjalmar C.; Besselink, Marc G.; Abdelhafez, M.; Andersson, R.; Andren-Sandberg, A.; Ashley, S.; van Baal, M.; Baron, T.; Bassi, C.; Bradley, E.; Buchler, M.; Cappendijk, V.; Carter, R.; Charnley, R.; Coelho, D.; Connor, S.; Dellinger, P.; Dervenis, C.; Deviere, J.; Doctor, N.; Dudeja, V.; En-qiang, M.; Escourrou, J.; Fagenholz, P.; Farkas, G.; Forsmark, C.; Freeman, M.; Freeny, P.; French, J.; Friess, H.; Gardner, T.; Goetzinger, P.; Haveman, J.; Hofker, S.; Imrie, C.; Isaji, S.; Isenmann, R.; Klar, E.; Laméris, J.; Lerch, M.; Lévy, P.; Lillemoe, K.; Löhr, M.; Mayerle, J.; Mayumi, T.; Mittal, A.; Moessner, J.; Morgan, D.; Mortele, K.; Nealon, W.; Neoptolemos, J.; Nieuwenhuijs, V.; Nordback, I.; Olah, A.; Oppong, K.; Padbury, R.; Papachristou, G.; Parks, R.; Poley, J.; Radenkovic, D.; Raraty, M.; Rau, B.; Rebours, V.; Rische, S.; Runzi, M.; Sainani, N.; Sarr, M.; Schaapherder, S.; Seewald, S.; Seifert, H.; Shimosegawa, T.; Silverman, S.; Singh, V.; Siriwardena, A.; Steinberg, W.; Sutton, R.; Takeda, K.; Timmer, R.; Vege, S.; Voermans, R.; de Waele, J.; Wang, Ch.; Warshaw, A.; Werner, J.; Weusten, B.; Whitcomb, D.; Wig, J.; Windsor, J.; Zyromski, N.

    2015-01-01

    Background The optimal diagnostic strategy and timing of intervention in infected necrotizing pancreatitis is subject to debate. We performed a survey on these topics amongst a group of international expert pancreatologists. Methods An online survey including case vignettes was sent to 118 international pancreatologists. We evaluated the use and timing of fine needle aspiration (FNA), antibiotics, catheter drainage and (minimally invasive) necrosectomy. Results The response rate was 74% (N = 87). None of the respondents use FNA routinely, 85% selectively and 15% never. Most respondents (87%) use a step-up approach in patients with infected necrosis. Walled-off necrosis (WON) is considered a prerequisite for endoscopic drainage and percutaneous drainage by 66% and 12%, respectively. After diagnosing infected necrosis, 55% routinely postpone invasive interventions, whereas 45% proceed immediately to intervention. Lack of consensus about timing of intervention was apparent on day 14 with proven infected necrosis (58% intervention vs. 42% non-invasive) as well as on day 20 with only clinically suspected infected necrosis (59% intervention vs. 41% non-invasive). Discussion The step-up approach is the preferred treatment strategy in infected necrotizing pancreatitis amongst expert pancreatologists. There is no uniformity regarding the use of FNA and timing of intervention in the first 2–3 weeks of infected necrotizing pancreatitis. PMID:26776851

  18. Strategies for transformation of naturally-occurring amphibian antimicrobial peptides into therapeutically valuable anti-infective agents.

    PubMed

    Conlon, J Michael; Al-Ghaferi, Nadia; Abraham, Bency; Leprince, Jérôme

    2007-08-01

    The emergence of strains of pathogenic microorganisms with resistance to commonly used antibiotics has necessitated a search for novel types of antimicrobial agents. Many frog species produce amphipathic alpha-helical peptides with broad spectrum antimicrobial activity in the skin but their therapeutic potential is limited by varying degrees of cytolytic activity towards eukaryotic cells. Methods for development of such peptides into anti-infective drugs are illustrated by the example of temporin-1DRa (HFLGTLVNLAK KIL.NH(2)). Studies with model alpha-helical peptides have shown that increase in cationicity promotes antimicrobial activity whereas increases in hydrophobicity, helicity and amphipathicity promote hemolytic activity and loss of selectivity for microorganisms. Analogs of temporin-1DRa in which each amino acid is replaced by L-lysine and D-lysine were synthesized and their cytolytic activities tested against a range of microorganisms and human erythrocytes. Small changes in structure produced marked changes in conformation, as determined by retention time on reversed-phase HPLC, and in biological activity. However, peptides containing the substitutions (Val(7) -->L-Lys), (Thr(5)-->D-Lys) and (Asn(8)-->D-Lys) retained the high solubility and potent, broad spectrum antimicrobial activity of the naturally occurring peptide but were appreciably (up to 10-fold) less hemolytic. In contrast, analogs in which Leu(9) and Ile(13) were replaced by the more hydrophobic cyclohexylglycine residue showed slightly increased antimicrobial potencies (up to 2-fold) but a 4-fold increase in hemolytic activity. The data suggest a strategy of selective increases in cationicity concomitant with decreases in helicity and hydrophobicity in the transformation of naturally-occurring antimicrobial peptides into non-toxic therapeutic agents.

  19. Contrasting Strategies of Alfalfa Stem Elongation in Response to Fall Dormancy in Early Growth Stage: The Tradeoff between Internode Length and Internode Number

    PubMed Central

    Wang, Zongli; Sun, Qizhong

    2015-01-01

    Fall dormancy (FD) in alfalfa (Medicago sativa L.) can be described using 11 FD ratings, is widely used as an important indicator of stress resistance, productive performance and spring growth. However, the contrasting growth strategies in internode length and internode number in alfalfa cultivars with different FD rating are poorly understood. Here, a growth chamber study was conducted to investigate the effect of FD on plant height, aboveground biomass, internode length, and internode number in alfalfa individuals in the early growth stages. In order to simulate the alfalfa growth environment in the early stage, 11 alfalfa cultivars with FD ratings from one to 11 were chosen and seeded at the greenhouse, and then were transplanted into an artificial growth chamber. The experimental design was a randomized complete block in a split-plot arrangement with three replicates. Plant height, above-ground biomass, internode length, and internode number were measured in early growth stage in all individuals. Our findings showed that plant height and the aboveground biomass of alfalfa did not significantly differ among 11 different FD rated cultivars. Also, internode length and internode number positively affected plant height and the aboveground biomass of alfalfa individuals and the average internode length significantly increased with increasing FD rating. However, internode number tended to sharply decline when the FD rating increased. Moreover, there were no correlations, slightly negative correlations, and strongly negative correlations between internode length and internode number in alfalfa individuals among the three scales, including within-FD ratings, within-FD categories and inter-FD ratings, respectively. Therefore, our results highlighted that contrasting growth strategies in stem elongation were adopted by alfalfa with different FD ratings in the early growth stage. Alfalfa cultivars with a high FD rating have longer internodes, whereas more dormant alfalfa

  20. Regulated CRISPR Modules Exploit a Dual Defense Strategy of Restriction and Abortive Infection in a Model of Prokaryote-Phage Coevolution

    PubMed Central

    Kumar, M. Senthil; Plotkin, Joshua B.; Hannenhalli, Sridhar

    2015-01-01

    CRISPRs offer adaptive immunity in prokaryotes by acquiring genomic fragments from infecting phage and subsequently exploiting them for phage restriction via an RNAi-like mechanism. Here, we develop and analyze a dynamical model of CRISPR-mediated prokaryote-phage coevolution that incorporates classical CRISPR kinetics along with the recently discovered infection-induced activation and autoimmunity side effects. Our analyses reveal two striking characteristics of the CRISPR defense strategy: that both restriction and abortive infections operate during coevolution with phages, driving phages to much lower densities than possible with restriction alone, and that CRISPR maintenance is determined by a key dimensionless combination of parameters, which upper bounds the activation level of CRISPRs in uninfected populations. We contrast these qualitative observations with experimental data on CRISPR kinetics, which offer insight into the spacer deletion mechanism and the observed low CRISPR prevalence in clinical isolates. More generally, we exploit numerical simulations to delineate four regimes of CRISPR dynamics in terms of its host, kinetic, and regulatory parameters. PMID:26544847

  1. Gene expression profiling and identification of resistance genes to aspergillus flavus infection in peanut through EST and microarray strategies.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aspergillus flavus and A. parasiticus infect peanut seeds and produce aflatoxins, which are associated with various diseases in domestic animals and humans throughout the world. The most cost-effective strategy to minimize aflatoxin contamination involves the development of peanut cultivars that are...

  2. Multi-Disciplinary Antimicrobial Strategies for Improving Orthopaedic Implants to Prevent Prosthetic Joint Infections in Hip and Knee

    PubMed Central

    Getzlaf, Matthew A.; Lewallen, Eric A.; Kremers, Hilal M.; Jones, Dakota L.; Bonin, Carolina A.; Dudakovic, Amel; Thaler, Roman; Cohen, Robert C.; Lewallen, David G.; van Wijnen, Andre J.

    2016-01-01

    Like any foreign object, orthopaedic implants are susceptible to infection when introduced into the human body. Without additional preventative measures, the absolute number of annual prosthetic joint infections will continue to rise, and may exceed the capacity of health care systems in the near future. Bacteria are difficult to eradicate from synovial joints due to their exceptionally diverse taxonomy, complex mechanistic attachment capabilities, and tendency to evolve antibiotic resistance. When a primary orthopaedic implant fails from prosthetic joint infection, surgeons are generally challenged by limited options for intervention. In this review, we highlight the etiology and taxonomic groupings of bacteria known to cause prosthetic joint infections, and examine their key mechanisms of attachment. We propose that antimicrobial strategies should focus on the most harmful bacteria taxa within the context of occurrence, taxonomic diversity, adhesion mechanisms, and implant design. Patient-specific identification of organisms that cause prosthetic joint infections will permit assessment of their biological vulnerabilities. The latter can be targeted using a range of antimicrobial techniques that exploit different colonization mechanisms including implant surface attachment, biofilm formation, and/or hematogenous recruitment. We anticipate that customized strategies for each patient, joint, and prosthetic component will be most effective at reducing prosthetic joint infections, including those caused by antibiotic-resistant and polymicrobial bacteria. PMID:26449208

  3. Conceptual framework for analysing farm-specific economic effects of helminth infections in ruminants and control strategies.

    PubMed

    van der Voort, Mariska; Charlier, Johannes; Lauwers, Ludwig; Vercruysse, Jozef; Van Huylenbroeck, Guido; Van Meensel, Jef

    2013-05-01

    Helminth infections are considered to be an important constraint on livestock productivity worldwide. The economic impact of these infections or their control strategies has traditionally been assessed by their effect on animal performance indicators or traditional economic calculation methods (e.g. budgeting and cost-benefit analysis). Because the impact of helminth infections has become more subtle and is farm-specific, one needs more refined economic evaluations of actions meant to increase or maintain the health of livestock on individual farms. This paper proposes an interdisciplinary framework that combines the developments in the veterinary control of helminth infections with economic performance measurements to identify farm-specific and profitable anthelmintic management decisions. Our framework positions individual farms' performance against performance benchmarks and is based on the farms' efficiency in transforming input(s) into output(s). We show how this positioning makes it possible to establish a linkage between input and output transformation, helminth infection levels and effects of control strategies. Furthermore, the framework allows for the identification of improvement paths that are not necessarily related to the helminth infection, but which may lead to other management improvements. We discuss the epidemiological information required and which complementary methods (e.g. efficiency analysis and budgeting techniques) can be used to make the framework operational.

  4. Multi-disciplinary antimicrobial strategies for improving orthopaedic implants to prevent prosthetic joint infections in hip and knee.

    PubMed

    Getzlaf, Matthew A; Lewallen, Eric A; Kremers, Hilal M; Jones, Dakota L; Bonin, Carolina A; Dudakovic, Amel; Thaler, Roman; Cohen, Robert C; Lewallen, David G; van Wijnen, Andre J

    2016-02-01

    Like any foreign object, orthopaedic implants are susceptible to infection when introduced into the human body. Without additional preventative measures, the absolute number of annual prosthetic joint infections will continue to rise, and may exceed the capacity of health care systems in the near future. Bacteria are difficult to eradicate from synovial joints due to their exceptionally diverse taxonomy, complex mechanistic attachment capabilities, and tendency to evolve antibiotic resistance. When a primary orthopaedic implant fails from prosthetic joint infection, surgeons are generally challenged by limited options for intervention. In this review, we highlight the etiology and taxonomic groupings of bacteria known to cause prosthetic joint infections, and examine their key mechanisms of attachment. We propose that antimicrobial strategies should focus on the most harmful bacteria taxa within the context of occurrence, taxonomic diversity, adhesion mechanisms, and implant design. Patient-specific identification of organisms that cause prosthetic joint infections will permit assessment of their biological vulnerabilities. The latter can be targeted using a range of antimicrobial techniques that exploit different colonization mechanisms including implant surface attachment, biofilm formation, and/or hematogenous recruitment. We anticipate that customized strategies for each patient, joint, and prosthetic component will be most effective at reducing prosthetic joint infections, including those caused by antibiotic-resistant and polymicrobial bacteria.

  5. Mapping the distribution of Anopheles funestus across Benin highlights a sharp contrast of susceptibility to insecticides and infection rate to Plasmodium between southern and northern populations

    PubMed Central

    2016-01-01

    Background. Malaria remains an important public health issue in Benin, with Anopheles gambiae s.l. and Anopheles funestus s.s being the predominant vectors. This study was designed to generate information on An. funestus distribution, molecular speciation, Plasmodium infection rate and insecticide susceptibility status across Benin. Methods. Mosquito samples were collected from December 2014 to January 2016 in 46 localities in Benin. These samples were mapped and An. funestus collected were speciated to the molecular level. Plasmodium infection rate was determined using a Taqman assay and susceptibility to insecticides was assessed using the WHO guidelines. The genotyping of the L119F- Gste2 mutation was also carried out.  Results.  An. funestus was found in 8 out of the 46 localities surveyed with a high presence in Tanongou (wet Sudanese ecological zone), Kpome, Doukonta and Pahou (sub-equatorial ecological zone). Molecular identifications revealed that only An. funestus s.s was present in southern Benin, whereas in Tanongou (northern Benin) An. funestus s.s. and An. leesoni were found in sympatry at proportions of 77.7% and 22.3% respectively. Plasmodium infection rate of An. funestus was higher in southern Benin at a range of 13 to 18% compared to 5.6% recorded in Tanongou. High DDT (8±0.5%) and permethrin (11±0.5%) resistance were observed in Doukonta, Kpome and Pahou, contrasting with relatively low resistance profiles: mortality-DDT=90±3.18% and mortality-permethrin=100% in Tanongou. Genotyping analysis revealed  high frequency  of the resistant 119F allele in the South (Kpome and Doukonta) compared to the North (Tanongou).  Discussion and Conclusion. The high presence of   An. funestus in the South compared to the North  could be due to favorable environmental and climatic conditions found in both regions. A significant Plasmodium infection rate was recorded across the country. A high resistance profile was recorded in the southern Benin; this

  6. A nonenzymatic optical immunoassay strategy for detection of Salmonella infection based on blue silica nanoparticles.

    PubMed

    Sun, Qian; Zhao, Guangying; Dou, Wenchao

    2015-10-22

    A novel nonenzymatic optical immunoassay strategy was for the first time designed and utilized for sensitive detection of antibody to Salmonella pullorum and Salmonella gallinarum (S. pullorum and S. gallinarum) in serum. The optical immunoassay strategy was based on blue silica nanoparticles (Blue-SiNps) and magnetic beads (MB). To construct such an optical immunoassay system, the Blue-SiNPs were first synthesized by inverse microemulsion method, characterized by SEM, Zeta potential and FTIR. Two nanostructures including Blue-SiNPs and MB were both functionalized with antibody against S. pullorum and S. gallinarum (anti-PG) without using enzyme labeled antibody. Anti-PG functionalized blue silica nanoparticles (IgG-Blue-SiNps) were used as signal transduction labels, while anti-PG functionalized magnetic beads (IgG-MB) were selected to separate and enrich the final sandwich immune complexes. In the process of detecting negative serum, a sandwich immunocomplex is formed between the IgG-MB and IgG-Blue-SiNPs. With the separation of the immunocomplex using an external magnetic field, the final plaque displayed bright blue color. While in the detection of infected serum, IgG-MB and anti-PG formed sandwich immunocomplexes, IgG-Blue-SiNPs were unable to bind to the limited sites of the antigen, and a light brown plaque was displayed in the bottom of microplate well. Stable results were obtained with an incubation time of 60 min at room temperature, and different colors corresponding to different results can be directly detected with naked eye. The reaction of IgG-Blue-SiNPs with S. pullorum was inhibited by 1:100 dilution of positive chicken serum. Such a simple immunoassay holds great potential as sensitive, selective and point-of-care (POC) tool for diagnosis of other biological molecules.

  7. Contrast Materials

    MedlinePlus

    ... veins of the body, including vessels in the brain, neck, chest, abdomen, pelvis and legs soft tissues of the body, including the muscles, fat and skin brain breast Microbubble Contrast Materials Microbubble contrast materials are ...

  8. Infection

    DTIC Science & Technology

    2010-09-01

    standing, diagnosis, and treatment of musculoskeletal infections. Key Words: musculoskeletal infection, biofilm , bacteria, biomaterial (J Orthop Trauma...form a biofilm , or slime layer.1 The recurrence of infections is often the result of microbial biofilm formation on the implant, enabling the persistence...Klebsiella pneumoniae). Staphylococcus species is by far the most studied pathogen in musculoskeletal infections and can produce a multilayered biofilm

  9. Challenges in linking preclinical anti-microbial research strategies with clinical outcomes for device-associated infections.

    PubMed

    Moriarty, T F; Grainger, D W; Richards, R G

    2014-09-12

    Infections related to implanted medical devices have become a significant health care issue in recent decades. Increasing numbers of medical devices are in use, often in an aging population, and these devices are implanted against a background of increasing antibiotic-resistant bacterial populations. Progressively more antibiotic resistant infections, requiring ever more refined treatment options, are therefore predicted to emerge with greater frequency in the coming decades. Improvements in the prevention, diagnosis and treatment of these device-associated infections will remain priority targets both for clinicians and the translational research community charged with addressing these challenges. Preclinical strategies, predictive of ultimate clinical efficacy, should serve as a control point for effective translation of new technologies to clinical applications. The development of new anti-infective medical devices requires a validated preclinical testing protocol; however, reliable validation of experimental and preclinical antimicrobial methodologies currently suffers from a variety of technical limitations. These include the lack of agreement or standardisation of experimental protocols, a general lack of correlation between in vitro and in vivo preclinical results and lack of validation between in vivo preclinical implant infection models and clinical (human) results. Device-associated infections pose additional challenges to practicing clinicians concerning diagnosis and treatment, both of which are complicated by the biofilms formed on the medical device. The critical challenges facing both preclinical research and clinical laboratories in improving both diagnosis and treatment of medical device-associated infections are the focus of this review.

  10. A Novel Non-Replication-Competent Cytomegalovirus Capsid Mutant Vaccine Strategy Is Effective in Reducing Congenital Infection

    PubMed Central

    Choi, K. Yeon; Root, Matthew

    2016-01-01

    ABSTRACT Congenital cytomegalovirus (CMV) infection is a leading cause of mental retardation and deafness in newborns. The guinea pig is the only small animal model for congenital CMV infection. A novel CMV vaccine was investigated as an intervention strategy against congenital guinea pig cytomegalovirus (GPCMV) infection. In this disabled infectious single-cycle (DISC) vaccine strategy, a GPCMV mutant virus was used that lacked the ability to express an essential capsid gene (the UL85 homolog GP85) except when grown on a complementing cell line. In vaccinated animals, the GP85 mutant virus (GP85 DISC) induced an antibody response to important glycoprotein complexes considered neutralizing target antigens (gB, gH/gL/gO, and gM/gN). The vaccine also generated a T cell response to the pp65 homolog (GP83), determined via a newly established guinea pig gamma interferon enzyme-linked immunosorbent spot assay. In a congenital infection protection study, GP85 DISC-vaccinated animals and a nonvaccinated control group were challenged during pregnancy with wild-type GPCMV (105 PFU). The pregnant animals carried the pups to term, and viral loads in target organs of pups were analyzed. Based on live pup births in the vaccinated and control groups (94.1% versus 63.6%), the vaccine was successful in reducing mortality (P = 0.0002). Additionally, pups from the vaccinated group had reduced CMV transmission, with 23.5% infected target organs versus 75.9% in the control group. Overall, these preliminary studies indicate that a DISC CMV vaccine strategy has the ability to induce an immune response similar to that of natural virus infection but has the increased safety of a non-replication-competent virus, which makes this approach attractive as a CMV vaccine strategy. IMPORTANCE Congenital CMV infection is a leading cause of mental retardation and deafness in newborns. An effective vaccine against CMV remains an elusive goal despite over 50 years of CMV research. The guinea pig, with

  11. Late Presentation of HIV Infection: Prevalence, Trends, and the Role of HIV Testing Strategies in Guangzhou, China, 2008–2013

    PubMed Central

    Cheng, Weibin; Tang, Weiming; Han, Zhigang; Tangthanasup, Thitikarn May; Zhong, Fei; Qin, Faju

    2016-01-01

    Background. The prevalence, trends, and the role of different HIV testing strategies in late presentation of HIV infection in China were unknown. Methods. Data of newly reported HIV cases in Guangzhou between 2008 and 2013 was analyzed to examine the prevalence, trends, and characteristics of late presentation of HIV infection by three types of HIV testing strategies. Results. Overall, 53.2% (1412/2653) and 27.3% (724/2653) met the criteria of late presentation and presentation with advanced HIV disease. The overall trend of late presentation of HIV infection within the study period was declining. Late presentation was 62.9% in 2008 and dropped to 43.3% in 2013 (P < 0.001); presentation with advanced HIV disease was 40.3% in 2008 and dropped to 15.2% in 2013 (P < 0.001). Of the three testing strategies, PITC presented higher odds of both late presentation [AOR (95% CI): PITC versus VCT: 1.37 (1.09, 1.73); PITC versus MHT: 3.09 (2.16, 4.42)] and presentation with advanced HIV disease [AOR (95% CI): PITC versus VCT: 1.65 (1.29, 2.11); PITC versus MHT: 13.14 (8.47, 20.39)]. Conclusions. Although the late presentation of HIV infection was declining, it was still high in Guangzhou. The worse situation among PITC cases urges the policy adjustment in medical settings to increase early HIV diagnosis. PMID:27761466

  12. Late Presentation of HIV Infection: Prevalence, Trends, and the Role of HIV Testing Strategies in Guangzhou, China, 2008-2013.

    PubMed

    Cheng, Weibin; Tang, Weiming; Han, Zhigang; Tangthanasup, Thitikarn May; Zhong, Fei; Qin, Faju; Xu, Huifang

    2016-01-01

    Background. The prevalence, trends, and the role of different HIV testing strategies in late presentation of HIV infection in China were unknown. Methods. Data of newly reported HIV cases in Guangzhou between 2008 and 2013 was analyzed to examine the prevalence, trends, and characteristics of late presentation of HIV infection by three types of HIV testing strategies. Results. Overall, 53.2% (1412/2653) and 27.3% (724/2653) met the criteria of late presentation and presentation with advanced HIV disease. The overall trend of late presentation of HIV infection within the study period was declining. Late presentation was 62.9% in 2008 and dropped to 43.3% in 2013 (P < 0.001); presentation with advanced HIV disease was 40.3% in 2008 and dropped to 15.2% in 2013 (P < 0.001). Of the three testing strategies, PITC presented higher odds of both late presentation [AOR (95% CI): PITC versus VCT: 1.37 (1.09, 1.73); PITC versus MHT: 3.09 (2.16, 4.42)] and presentation with advanced HIV disease [AOR (95% CI): PITC versus VCT: 1.65 (1.29, 2.11); PITC versus MHT: 13.14 (8.47, 20.39)]. Conclusions. Although the late presentation of HIV infection was declining, it was still high in Guangzhou. The worse situation among PITC cases urges the policy adjustment in medical settings to increase early HIV diagnosis.

  13. Alternative fluorescent labeling strategies for characterizing gram-positive pathogenic bacteria: Flow cytometry supported counting, sorting, and proteome analysis of Staphylococcus aureus retrieved from infected host cells.

    PubMed

    Hildebrandt, Petra; Surmann, Kristin; Salazar, Manuela Gesell; Normann, Nicole; Völker, Uwe; Schmidt, Frank

    2016-10-01

    Staphylococcus aureus is a Gram-positive opportunistic pathogen that is able to cause a broad range of infectious diseases in humans. Furthermore, S. aureus is able to survive inside nonprofessional phagocytic host cell which serve as a niche for the pathogen to hide from the immune system and antibiotics therapies. Modern OMICs technologies provide valuable tools to investigate host-pathogen interactions upon internalization. However, these experiments are often hampered by limited capabilities to retrieve bacteria from such an experimental setting. Thus, the aim of this study was to develop a labeling strategy allowing fast detection and quantitation of S. aureus in cell lysates or infected cell lines by flow cytometry for subsequent proteome analyses. Therefore, S. aureus cells were labeled with the DNA stain SYTO(®) 9, or Vancomycin BODIPY(®) FL (VMB), a glycopeptide antibiotic binding to most Gram-positive bacteria which was conjugated to a fluorescent dye. Staining of S. aureus HG001 with SYTO 9 allowed counting of bacteria from pure cultures but not in cell lysates from infection experiments. In contrast, with VMB it was feasible to stain bacteria from pure cultures as well as from samples of infection experiments. VMB can also be applied for histocytochemistry analysis of formaldehyde fixed cell layers grown on coverslips. Proteome analyses of S. aureus labeled with VMB revealed that the labeling procedure provoked only minor changes on proteome level and allowed cell sorting and analysis of S. aureus from infection settings with sensitivity similar to continuous gfp expression. Furthermore, VMB labeling allowed precise counting of internalized bacteria and can be employed for downstream analyses, e.g., proteomics, of strains not easily amendable to genetic manipulation such as clinical isolates. © 2016 International Society for Advancement of Cytometry.

  14. Neonatology in the emerging countries: the strategies and health-economics challenges related to prevention of neonatal and infant infections.

    PubMed

    Vain, N E; Fariña, D; Vázquez, L N

    2012-05-01

    The prevalence of neonatal and infant infections is higher in emerging countries when compared to the developed world. Major factors associated to this increased frequency include the scarcity of trained health personnel, overcrowding of the neonatal units, late onset and slow advance of feeding, use of formula instead of breastfeeding, failure to comply with handwashing recommendations, and excessive use of antibiotics, resulting in the emergence of resistant strains. Infants discharged home frequently share rooms with a large number of siblings and other cohabitants, increasing the risk of infection by respiratory viruses. Several strategies are described that could decrease these serious problems which impact increasing significantly neonatal and infant mortality rates in developing countries.

  15. Amphotericin B-conjugated biogenic silver nanoparticles as an innovative strategy for fungal infections.

    PubMed

    Ahmad, Aftab; Wei, Yun; Syed, Fatima; Tahir, Kamran; Taj, Raheela; Khan, Arif Ullah; Hameed, Muhammad Usman; Yuan, Qipeng

    2016-10-01

    New strategies are required to improve the efficacy of drugs and to treat the emerging microbial resistance. An effective strategy is to combine drugs with metal nanoparticles for the control of microbial infections and resistance. Keeping in view this fact, we developed a facile and eco-friendly protocol for the synthesis of amphotericin B-conjugated silver nanoparticles and their assessment as an antifungal agent. Phytochemicals from the aqueous extract of Maytenus royleanus and amphotericin B were used as capping agents to prepare two types of silver nanoparticles i.e. (i) biogenic silver nanoparticles (b-AgNPs) and (ii) amphotericin B-conjugated biogenic silver nanoparticles (Amp-bAgNPs). UV-Vis spectroscopy was used to detect the characteristic surface Plasmon resonance peaks (SPR) for the prepared nanoparticles (424-433 nm). High-resolution transmission electron microscopy (HRTEM) study revealed the formation of well dispersed and spherical silver nanoparticles and Amp-bAgNPs with an average particles size of 10 and 15 nm. EDX and FTIR studies confirmed the elemental composition and surface adhered biomolecules in the prepared nanoparticles respectively. Biogenic silver nanoparticles revealed low to moderate antifungal activity (4-8 mm ± 0.2), however, the amphotericin B conjugated silver nanoparticles exhibited significant activity against Candida albicans (16 mm ± 1.4) and Candida tropicalis (18 mm ± 1.5). In conclusion, the enhanced antifungal activity of the Amp-AgNPs conjugate system is due to the synergy between the antifungal activity of amphotericin B and the antimicrobial property of silver. The findings of this study suggest that the conjugated nanoparticles could be used as efficient antifungal agents and drug delivery vehicles. Furthermore, this is the first report describing the synthesis of silver nanoparticles using the aqueous extract of Maytenus royleanus and the conjugation of amphotericin B, an antifungal drug, to the

  16. Global Scale Transcriptional Profiling of Two Contrasting Barley Genotypes Exposed to Moderate Drought Conditions: Contribution of Leaves and Crowns to Water Shortage Coping Strategies

    PubMed Central

    Svoboda, Pavel; Janská, Anna; Spiwok, Vojtěch; Prášil, Ilja T.; Kosová, Klára; Vítámvás, Pavel; Ovesná, Jaroslava

    2016-01-01

    Drought is a serious threat for sustainable agriculture. Barley represents a species well adapted to environmental stresses including drought. To elucidate the adaptive mechanism of barley on transcriptional level we evaluated transcriptomic changes of two contrasting barley cultivars upon drought using the microarray technique on the level of leaves and crowns. Using bioinformatic tools, differentially expressed genes in treated vs. non-treated plants were identified. Both genotypes revealed tissue dehydration under drought conditions as shown at water saturation deficit and osmotic potential data; however, dehydration was more severe in Amulet than in drought-resistant Tadmor under the same ambient conditions. Performed analysis showed that Amulet enhanced expression of genes related to active plant growth and development, while Tadmor regarding the stimulated genes revealed conservative, water saving strategy. Common reactions of both genotypes and tissues included an induction of genes encoding several stress-responsive signaling proteins, transcription factors as well as effector genes encoding proteins directly involved in stress acclimation. In leaf, tolerant cultivar effectively stimulated mainly the expression of genes encoding proteins and enzymes involved in protein folding, sulfur metabolism, ROS detoxification or lipid biosynthesis and transport. The crown specific reaction of tolerant cultivar was an enhanced expression of genes encoding proteins and enzymes involved in cell wall lignification, ABRE-dependent abscisic acid (ABA) signaling, nucleosome remodeling, along with genes for numerous jasmonate induced proteins. PMID:28083001

  17. Global Scale Transcriptional Profiling of Two Contrasting Barley Genotypes Exposed to Moderate Drought Conditions: Contribution of Leaves and Crowns to Water Shortage Coping Strategies.

    PubMed

    Svoboda, Pavel; Janská, Anna; Spiwok, Vojtěch; Prášil, Ilja T; Kosová, Klára; Vítámvás, Pavel; Ovesná, Jaroslava

    2016-01-01

    Drought is a serious threat for sustainable agriculture. Barley represents a species well adapted to environmental stresses including drought. To elucidate the adaptive mechanism of barley on transcriptional level we evaluated transcriptomic changes of two contrasting barley cultivars upon drought using the microarray technique on the level of leaves and crowns. Using bioinformatic tools, differentially expressed genes in treated vs. non-treated plants were identified. Both genotypes revealed tissue dehydration under drought conditions as shown at water saturation deficit and osmotic potential data; however, dehydration was more severe in Amulet than in drought-resistant Tadmor under the same ambient conditions. Performed analysis showed that Amulet enhanced expression of genes related to active plant growth and development, while Tadmor regarding the stimulated genes revealed conservative, water saving strategy. Common reactions of both genotypes and tissues included an induction of genes encoding several stress-responsive signaling proteins, transcription factors as well as effector genes encoding proteins directly involved in stress acclimation. In leaf, tolerant cultivar effectively stimulated mainly the expression of genes encoding proteins and enzymes involved in protein folding, sulfur metabolism, ROS detoxification or lipid biosynthesis and transport. The crown specific reaction of tolerant cultivar was an enhanced expression of genes encoding proteins and enzymes involved in cell wall lignification, ABRE-dependent abscisic acid (ABA) signaling, nucleosome remodeling, along with genes for numerous jasmonate induced proteins.

  18. Contrastive Lexicology.

    ERIC Educational Resources Information Center

    Hartmann, R. R. K.

    This paper deals with the relation between etymologically related words in different languages. A survey is made of seven stages in the development of contrastive lexicology. These are: prelinguistic word studies, semantics, lexicography, translation, foreign language learning, bilingualism, and finally contrastive analysis. Concerning contrastive…

  19. Contrastive Analysis.

    ERIC Educational Resources Information Center

    James, Carl

    Contrastive analysis is viewed as an interlinguistic, bidirectional phenomenon which is concerned with both the form and function of language. As such, contrastive analysis must view language psycholinguistically and sociolinguistically as a system to be both described and acquired. Due to the need for a psychological component in the analysis,…

  20. The global swine flu pandemic 2: infection control measures and preparedness strategies.

    PubMed

    Pratt, Robert J

    This second in a two-part unit on swine flu looks at infection control measures for nurses. During late spring and early summer, increasing numbers of people became infected with novel swine origin influenza type A virus (influenza A(H1N1)v 2009) and a global pandemic started. Part 1 of this unit explored the biology of influenza viruses and the origins and characteristics of flu pandemics. This part reviews viral transmission, infection prevention and control and pandemic preparedness.

  1. [Strategies for management of difficult to treat Gram-negative infections: focus on Pseudomonas aeruginosa].

    PubMed

    Bassetti, Matteo

    2007-09-01

    Pseudomonas aeruginosa is often involved in the aetiology of numerous infections, particularly those occurring in hospital. The infections in which P. aeruginosa most frequently has a pathogenic role include respiratory tract infections, particularly those occurring in patients with chronic obstructive pulmonary disease (COPD), nosocomial pneumonia, ventilator-associated pneumonia, and cystic fibrosis, as well as those developing in patients with AIDS, bacteraemia, sepsis, urinary tract infections, especially those related to catheterisation or kidney transplants, infections in neutropenic patients, and skin infections, particular those developing in surgical wounds or in burns. Thus, in practice, P. aeruginosa is ubiquitously present in all body districts. Particular attention should also be given to the presence of P. aeruginosa in the community setting, for example when it causes community-acquired pneumonia in the elderly or pneumonia in patients with advanced stage COPD. The mortality rate of patients with severe P. aeruginosa infections is very high. Treatment should be initiated very promptly with the most suitable drug, perhaps making use of combination therapy with a beta-lactam and a fluoroquinolone when indicated, and continued for a sufficiently long period. As far as concerns future therapeutic options for the treatment of P. aeruginosa infections, the only two new molecules that will probably become available are doripenem and ceftobiprole. Given this prospective, trust must be placed in the already known drugs, exploiting them more appropriately.

  2. Infection

    MedlinePlus

    ... 23(4):251-69. Association for Professionals in Infection Control and Epidemiology (APIC) guideline. Back to Top Administration ... : Hospital Scope | Glossary | References | Site Map | Credits Freedom of ...

  3. Evolving New Strategies for the Medical Management of Chronic Hepatitis B Virus Infection

    PubMed Central

    Zhou, Tianlun; Anbarasan, Nikhil; Gish, Robert

    2016-01-01

    Is a cure for chronic hepatitis B virus (HBV) infection possible? Hepatitis C virus infection is now routinely cured medically. There is a growing expectation that new drugs for the management of chronic HBV infection should provide substantial benefit over and above that of current chronic HBV medications, if not be curative. Although the definition of medically induced cure for chronic HBV infection varies, most include sustained off-drug absence of viremia and negativity for other virologic markers. There are currently more than 29 drugs in the pipeline being tested for the management of chronic HBV infection. This article discusses the potential drugs with respect to their possible contributions to achieving medically induced cure. PMID:28035197

  4. RNA-guided endonuclease provides a therapeutic strategy to cure latent herpesviridae infection.

    PubMed

    Wang, Jianbin; Quake, Stephen R

    2014-09-09

    Latent viral infection is a persistent cause of human disease. Although standard antiviral therapies can suppress active viral replication, no existing treatment can effectively eradicate latent infection and therefore a cure is lacking for many prevalent viral diseases. The prokaryotic immune system clustered regularly interspaced short palindromic repeat (CRISPR)/Cas evolved as a natural response to phage infections, and we demonstrate here that the CRISPR/Cas9 system can be adapted for antiviral treatment in human cells by specifically targeting the genomes of latent viral infections. Patient-derived cells from a Burkitt's lymphoma with latent Epstein-Barr virus infection showed dramatic proliferation arrest and a concomitant decrease in viral load after exposure to a CRISPR/Cas9 vector targeted to the viral genome.

  5. RNA-guided endonuclease provides a therapeutic strategy to cure latent herpesviridae infection

    PubMed Central

    Wang, Jianbin; Quake, Stephen R.

    2014-01-01

    Latent viral infection is a persistent cause of human disease. Although standard antiviral therapies can suppress active viral replication, no existing treatment can effectively eradicate latent infection and therefore a cure is lacking for many prevalent viral diseases. The prokaryotic immune system clustered regularly interspaced short palindromic repeat (CRISPR)/Cas evolved as a natural response to phage infections, and we demonstrate here that the CRISPR/Cas9 system can be adapted for antiviral treatment in human cells by specifically targeting the genomes of latent viral infections. Patient-derived cells from a Burkitt’s lymphoma with latent Epstein–Barr virus infection showed dramatic proliferation arrest and a concomitant decrease in viral load after exposure to a CRISPR/Cas9 vector targeted to the viral genome. PMID:25157128

  6. Infection risk in systemic lupus erythematosus patients: susceptibility factors and preventive strategies.

    PubMed

    Danza, A; Ruiz-Irastorza, G

    2013-10-01

    Infection is one of the leading causes of morbidity and mortality in systemic lupus erythematosus (SLE). Bacterial infections are most frequent, followed by viral and fungal infections. The impaired cellular and humoral immune functions seen in patients with SLE are predisposing conditions, whilst disease activity, prednisone doses over 7.5-10 mg/day, high doses of methylprednisolone or cyclophosphamide are well-recognised risk factors for infection. The first six months after rituximab treatment and the use of more than three courses are also associated with an increased susceptibility for infection. It has not been established whether belimumab, azathioprine and mycophenolate mofetil increase the risk of serious infections. Most vaccines are effective and safe in SLE patients, although vaccination should be avoided during periods of active disease. Live virus vaccines are contraindicated for immunosuppressed patients. Influenza and pneumococcal vaccines are universally recommended. Tuberculosis prophylaxis should be considered in selected cases. Therefore, it is advisable not to exceed doses of 5 mg/day of prednisone in chronic treatment. Methylprednisolone and cyclophosphamide should be used in low-dose regimens. Antimalarials have a well-known protective role against infection, in addition to other beneficial properties, thus, hydroxychloroquine is recommended for all SLE patients where no contraindication exists.

  7. Microbial Biofilms in Urinary Tract Infections and Prostatitis: Etiology, Pathogenicity, and Combating strategies

    PubMed Central

    Delcaru, Cristina; Alexandru, Ionela; Podgoreanu, Paulina; Grosu, Mirela; Stavropoulos, Elisabeth; Chifiriuc, Mariana Carmen; Lazar, Veronica

    2016-01-01

    Urinary tract infections (UTIs) are one of the most important causes of morbidity and health care spending affecting persons of all ages. Bacterial biofilms play an important role in UTIs, responsible for persistent infections leading to recurrences and relapses. UTIs associated with microbial biofilms developed on catheters account for a high percentage of all nosocomial infections and are the most common source of Gram-negative bacteremia in hospitalized patients. The purpose of this mini-review is to present the role of microbial biofilms in the etiology of female UTI and different male prostatitis syndromes, their consequences, as well as the challenges for therapy. PMID:27916925

  8. Microbial Biofilms in Urinary Tract Infections and Prostatitis: Etiology, Pathogenicity, and Combating strategies.

    PubMed

    Delcaru, Cristina; Alexandru, Ionela; Podgoreanu, Paulina; Grosu, Mirela; Stavropoulos, Elisabeth; Chifiriuc, Mariana Carmen; Lazar, Veronica

    2016-11-30

    Urinary tract infections (UTIs) are one of the most important causes of morbidity and health care spending affecting persons of all ages. Bacterial biofilms play an important role in UTIs, responsible for persistent infections leading to recurrences and relapses. UTIs associated with microbial biofilms developed on catheters account for a high percentage of all nosocomial infections and are the most common source of Gram-negative bacteremia in hospitalized patients. The purpose of this mini-review is to present the role of microbial biofilms in the etiology of female UTI and different male prostatitis syndromes, their consequences, as well as the challenges for therapy.

  9. Control strategies to prevent total hip replacement-related infections: a systematic review and mixed treatment comparison

    PubMed Central

    Zheng, Henry; Barnett, Adrian G; Merollini, Katharina; Sutton, Alex; Cooper, Nicola; Berendt, Tony; Wilson, Jennie; Graves, Nicholas

    2014-01-01

    Objective To synthesise the available evidence and estimate the comparative efficacy of control strategies to prevent total hip replacement (THR)-related surgical site infections (SSIs) using a mixed treatment comparison. Design Systematic review and mixed treatment comparison. Setting Hospital and other healthcare settings. Participants Patients undergoing THR. Primary and secondary outcome measures The number of THR-related SSIs occurring following the surgical operation. Results 12 studies involving 123 788 THRs and 9 infection control strategies were identified. The strategy of ‘systemic antibiotics+antibiotic-impregnated cement+conventional ventilation’ significantly reduced the risk of THR-related SSI compared with the referent strategy (no systemic antibiotics+plain cement+conventional ventilation), OR 0.13 (95% credible interval (CrI) 0.03–0.35), and had the highest probability (47–64%) and highest median rank of being the most effective strategy. There was some evidence to suggest that ‘systemic antibiotics+antibiotic-impregnated cement+laminar airflow’ could potentially increase infection risk compared with ‘systemic antibiotics+antibiotic-impregnated cement+conventional ventilation’, 1.96 (95% CrI 0.52–5.37). There was no high-quality evidence that antibiotic-impregnated cement without systemic antibiotic prophylaxis was effective in reducing infection compared with plain cement with systemic antibiotics, 1.28 (95% CrI 0.38–3.38). Conclusions We found no convincing evidence in favour of the use of laminar airflow over conventional ventilation for prevention of THR-related SSIs, yet laminar airflow is costly and widely used. Antibiotic-impregnated cement without systemic antibiotics may not be effective in reducing THR-related SSIs. The combination with the highest confidence for reducing SSIs was ‘systemic antibiotics+antibiotic-impregnated cement+conventional ventilation’. Our evidence synthesis underscores the need to review

  10. Prevention of catheter-related bloodstream infections in patients on hemodialysis: challenges and management strategies.

    PubMed

    Soi, Vivek; Moore, Carol L; Kumbar, Lalathakasha; Yee, Jerry

    2016-01-01

    Catheter-related bloodstream infections are a significant source of morbidity and mortality in the end-stage renal disease population. Although alternative accesses to undergoing renal replacement therapy exist, many patients begin hemodialysis with a dialysis catheter due to logistic and physiologic factors involved in arteriovenous fistula creation and maturation. Colonization of catheters via skin flora leads to the production of biofilm, which acts as a reservoir for virulent bacteria. Preventative therapies center on appropriate catheter maintenance, infection control measures, and early removal of devices as patients transition to other access. Despite best efforts, when conservative measures fail to prevent infections in a high-risk population, antimicrobial lock therapy should be considered as an option to combat catheter-related bloodstream infections.

  11. Prevention of catheter-related bloodstream infections in patients on hemodialysis: challenges and management strategies

    PubMed Central

    Soi, Vivek; Moore, Carol L; Kumbar, Lalathakasha; Yee, Jerry

    2016-01-01

    Catheter-related bloodstream infections are a significant source of morbidity and mortality in the end-stage renal disease population. Although alternative accesses to undergoing renal replacement therapy exist, many patients begin hemodialysis with a dialysis catheter due to logistic and physiologic factors involved in arteriovenous fistula creation and maturation. Colonization of catheters via skin flora leads to the production of biofilm, which acts as a reservoir for virulent bacteria. Preventative therapies center on appropriate catheter maintenance, infection control measures, and early removal of devices as patients transition to other access. Despite best efforts, when conservative measures fail to prevent infections in a high-risk population, antimicrobial lock therapy should be considered as an option to combat catheter-related bloodstream infections. PMID:27143948

  12. The Strategy to Survive Primary Malaria Infection: An Experimental Study on Behavioural Changes in Parasitized Birds

    PubMed Central

    Mukhin, Andrey; Palinauskas, Vaidas; Platonova, Elena; Kobylkov, Dmitry; Vakoliuk, Irina; Valkiūnas, Gediminas

    2016-01-01

    Avian malaria parasites (Haemosporida, Plasmodium) are of cosmopolitan distribution, and they have a significant impact on vertebrate host fitness. Experimental studies show that high parasitemia often develops during primary malaria infections. However, field studies only occasionally reveal high parasitemia in free-living birds sampled using the traditional methods of mist-netting or trapping, and light chronic infections predominate. The reason for this discrepancy between field observation and experimental data remains insufficiently understood. Since mist-netting is a passive capture method, two main parameters determine its success in sampling infected birds in wildlife, i. e. the presence of parasitized birds at a study site and their mobility. In other words, the trapping probability depends on the survival rate of birds and their locomotor activity during infection. Here we test (1) the mortality rate of wild birds infected with Plasmodium relictum (the lineage pSGS1), (2) the changes in their behaviour during presence of an aerial predator, and (3) the changes in their locomotor activity at the stage of high primary parasitemia.We show that some behavioural features which might affect a bird's survival during a predator attack (time of reaction, speed of flush flight and take off angle) did not change significantly during primary infection. However, the locomotor activity of infected birds was almost halved compared to control (non-infected) birds during the peak of parasitemia. We report (1) the markedly reduced mobility and (2) the 20% mortality rate caused by P. relictum and conclude that these factors are responsible for the underrepresentation of birds in mist nets and traps during the stage of high primary parasitemia in wildlife. This study indicates that the widespread parasite, P. relictum (pSGS1) influences the behaviour of birds during primary parasitemia. Experimental studies combined with field observations are needed to better understand the

  13. Necrotizing soft tissue infections. Risk factors for mortality and strategies for management.

    PubMed Central

    Elliott, D C; Kufera, J A; Myers, R A

    1996-01-01

    OBJECTIVE: The authors evaluate in a retrospective fashion the factors influencing outcome in a large group of patients presenting with necrotizing soft tissue infections, and, based on this analysis, propose a plan for optimal care of such patients. SUMMARY BACKGROUND DATA: In many smaller series of patients with necrotizing soft tissue infections, similar analyses of risk factors for mortality have been performed, producing conflicting conclusions regarding optimal care. In particular, debate exists regarding the impact of concurrent physiologic derangements, type and extent of infection, and the role of hyperbaric oxygen in treatment. METHODS: A retrospective chart review of 198 consecutive patients with documented necrotizing soft tissue infections, treated at a single institution during an 8-year period, was conducted. Using a model for logistic regression analysis, characteristics of each patient and his/her clinical course were tested for impact on outcome. RESULTS: The mortality rate among the 198 patients was 25.3%. The most common sites of origin of infection were the perineum (Fournier's disease; 36% of cases) and the foot (in diabetics; 15.2%). By logistic regression analysis, risk factors for death included age, female gender, extent of infection, delay in first debridement, elevated serum creatinine level, elevated blood lactate level, and degree of organ system dysfunction at admission. Diabetes mellitus did not predispose patients to death, except in conjunction with renal dysfunction or peripheral vascular disease. Myonecrosis, noted in 41.4% of the patients who underwent surgery, did not influence mortality. CONCLUSIONS: Necrotizing soft tissue infections represent a group of highly lethal infections best treated by early and repeated extensive debridement and broad-spectrum antibiotics. Hyperbaric oxygen appears to offer the advantage of early wound closure. Certain markers predict those individuals at increased risk for multiple-organ failure

  14. Contrast lipocryolysis

    PubMed Central

    Pinto, Hernán; Melamed, Graciela

    2014-01-01

    Alternative crystal structures are possible for all lipids and each different crystal structure is called a polymorphic form. Inter-conversion between polymorphisms would imply the possibility of leaning crystal formation toward the most effective polymorphism for adipocyte destruction. Food industry has been tempering lipids for decades. Tempering technology applied to lipocryolysis gave birth to “contrast lipocryolysis”, which involves pre- and post-lipocryolysis fat layer heating as part of a specific tempering protocol. In this study, we evaluated the skinfold thickness of 10 subjects after a single contrast lipocryolysis session and witnessed important and fast reductions. PMID:25068088

  15. Saving our children: strategies to empower African-American adolescents to reduce their risk for HIV infection.

    PubMed

    Jemmott, L S

    2000-01-01

    Adolescence is normally a healthy period of life. For some young people it is a period of experimentation with risky behavior. For others, it marks the development of habitual risk behaviors that persist into adulthood. Of special concern is adolescent involvement with sexual behaviors that increase the risk of infection with HIV and other sexually transmitted diseases (STDs). Nurses who work with adolescents are seeing an increase in STDs, including HIV infection occurring disproportionately among African-American adolescents. Although the use of condoms can reduce the risk of these sexually transmitted diseases, most sexually active adolescents do not consistently use condoms. This paper will discuss the scope of the problem of STDs, especially HIV infection among African-American adolescents. It will describe the Theory of Planned Behavior as a framework for designing interventions to reduce the sexual transmission of HIV and other STDs. Finally, it will provide strategies for nurses to intervene by empowering African-American adolescents to reduce their risk for sexually transmitted HIV infection.

  16. Operative strategies in aortic graft infections: is complete graft excision always necessary?

    PubMed

    Hart, Joseph P; Eginton, Mark T; Brown, Kellie R; Seabrook, Gary R; Lewis, Brian D; Edmiston, Charles E; Towne, Jonathan B; Cambria, Robert A

    2005-03-01

    The classic approach to aortic graft infections involves complete excision of the graft material with remote reconstruction of the distal circulation. Certain patients may not be well suited for this approach for physiologic or anatomic reasons. This study was undertaken to determine the outcome of partial graft excision in selected patients with aortic graft infection who were not felt to be candidates for complete graft excision. Retrospective analysis of 30 consecutive patients treated with infected grafts arising from the aorta over the past 10 years was performed. Mean interval between graft placement and infection was 5.5 years. Complete graft excision with bypass via clean tissue planes was achieved in 15 patients (group A), and partial or complete graft salvage or in situ graft replacement was performed at the discretion of the surgeon in 15 patients (group B). Perioperative mortality occurred in eight subjects (27%), including six in group A (40%) and two in group B (13%; p = NS). Six patients (20%) developed recurrent infection following graft excision, two (13%) in group A and four (27%) in group B (p = NS). Microorganisms were recovered from 24 of 30 (80%) graft cultures: 13 (43%) were gram positive, 4 (13%) were gram negative, and both gram-positive and gram-negative organisms were recovered from 7 (23%). Identification of culture isolates did not influence either perioperative mortality or the development of recurrent infection. Long-term survival was no different between the groups. We conclude that in certain high-risk patients who may not tolerate complete graft excision, local resection of infected graft segments may be preferable and leads to similar short- and long-term outcome.

  17. A Mouse Model of Latent Tuberculosis Infection to Study Intervention Strategies to Prevent Reactivation

    PubMed Central

    Kupz, Andreas; Zedler, Ulrike; Stäber, Manuela

    2016-01-01

    Infection with Mycobacterium tuberculosis (Mtb) is the leading cause of death in human immunodeficiency virus (HIV)+ individuals, particularly in Sub-Saharan Africa. Management of this deadly co-infection is a significant global health challenge that is exacerbated by the lack of efficient vaccines against both Mtb and HIV, as well as the lack of reliable and robust animal models for Mtb/HIV co-infection. Here we describe a tractable and reproducible mouse model to study the reactivation dynamics of latent Mtb infection following the loss of CD4+ T cells as it occurs in HIV-co-infected individuals. Whereas intradermally (i.d.) infected C57BL/6 mice contained Mtb within the local draining lymph nodes, depletion of CD4+ cells led to progressive systemic spread of the bacteria and induction of lung pathology. To interrogate whether reactivation of Mtb after CD4+ T cell depletion can be reversed, we employed interleukin (IL)-2/anti-IL-2 complex-mediated cell boost approaches. Although populations of non-CD4 lymphocytes, such as CD8+ memory T cells, natural killer (NK) cells and double-negative (DN) T cells significantly expanded after IL-2/anti-IL-2 complex treatment, progressive development of bacteremia and pathologic lung alterations could not be prevented. These data suggest that the failure to reverse Mtb reactivation is likely not due to anergy of the expanded cell subsets and rather indicates a limited potential for IL-2-complex-based therapies in the management of Mtb/HIV co-infection. PMID:27391012

  18. Infection,

    DTIC Science & Technology

    1980-10-16

    inapparent infection. A refeeding program may thus become complicated by the sudden appearance of a life-threatening infectious illness (3). (3) The...Beisel, W. R. 23 Unusually low serum concentrations of inorganic phosphate have been reported in patients with gram-negative sepsis and in Reye’s syndrome ...infection should be corrected by a well-managed program of convalescent-period refeeding . This aspect of nutritional support is too often ignored. On the

  19. [Strategies for management of resistant Gram-positive infections: from S. pneumoniae to MRSA].

    PubMed

    Cristini, Francesco

    2007-09-01

    S. pneumoniae and methicillin-resistant S. aureus are the main Gram-positive pathogens responsible for severe infections. In the context of community infections S. pneumoniae is the leading Gram-positive pathogen causing severe infections such as purulent meningitis and pneumonia. The typical pattern of antibiotic sensitivity of this bacterium, frequently resistant to macrolides and with significantly reduced sensitivity to penicillin, is only a relative therapeutic problem in that the preserved sensitivity to third-generation cephalosporins and respiratory fluoroquinolones is sufficient to make these antibiotics valid therapeutic solutions without having to use the latest generation of drugs. On the other hand, methicillin-resistant S. aureus, one of the main bacteria responsible for nosocomial infections such as bacteraemia and respiratory tract infections in severely ill patients, is a more challenging therapeutic problem since, historically, the therapeutic options available in clinical practice have been fewer and essentially limited to glycopeptides. The recent availability of oxazolidinones and the pharmacologically more rational and appropriate use of the glycopeptides have undoubtedly brought substantial benefits; the imminent introduction of new molecules active against Gram-positive pathogens will certainly make an important contribution, although their use in clinical practice will need to be monitored.

  20. Contemporary HIV Vaccines: Tissue Resident T-Cells and Strategies to Prevent Mucosal Infection.

    PubMed

    Tan, Hyon-Xhi; Kent, Stephen J; De Rose, Robert

    2016-01-01

    HIV is primarily transmitted to women via the cervicovaginal mucosa, with the infection remaining localized for several days prior to systemic dissemination and irreversible damage to the immune system. The early phase during which HIV infection is localized and exhibits little or no viral diversity presents a vantage point for HIV vaccines that stimulate T-cell mediated clearance. CD(8+) resident memory T-cells (TRM) are positioned at mucosal entry sites and are established upon resolution of infection by mucosal pathogens. TRM cells are long-lived and locally patrol mucosal tissues. Upon antigenic reactivation, the sentinel-like functions of TRM cells mediate rapid clearance of subsequent infection by recruitment of additional immune cells from circulation and initiate a tissue-wide antiviral state, thus preventing the recurrence of disease. These properties are ideally suited for an HIV vaccine aimed at halting the infection cycle of HIV during the earliest phases. In this review, we summarize recent vaccine developments from parallel research areas incorporating the use of live mucosal vectors complemented with chemokine-regulating compounds, which can induce the seeding of the vaginal mucosa with TRM cells. We present the proposition that similar novel vaccine regimens can be translated into approaches for future HIV vaccines aimed at inducing heightened immunity in vaginal tissues against HIV.

  1. Strategies to increase the activity of microglia as efficient protectors of the brain against infections

    PubMed Central

    Nau, Roland; Ribes, Sandra; Djukic, Marija; Eiffert, Helmut

    2014-01-01

    In healthy individuals, infections of the central nervous system (CNS) are comparatively rare. Based on the ability of microglial cells to phagocytose and kill pathogens and on clinical findings in immunocompromised patients with CNS infections, we hypothesize that an intact microglial function is crucial to protect the brain from infections. Phagocytosis of pathogens by microglial cells can be stimulated by agonists of receptors of the innate immune system. Enhancing this pathway to increase the resistance of the brain to infections entails the risk of inducing collateral damage to the nervous tissue. The diversity of microglial cells opens avenue to selectively stimulate sub-populations responsible for the defence against pathogens without stimulating sub-populations which are responsible for collateral damage to the nervous tissue. Palmitoylethanolamide (PEA), an endogenous lipid, increased phagocytosis of bacteria by microglial cells in vitro without a measurable proinflammatory effect. It was tested clinically apparently without severe side effects. Glatiramer acetate increased phagocytosis of latex beads by microglia and monocytes, and dimethyl fumarate enhanced elimination of human immunodeficiency virus from infected macrophages without inducing a release of proinflammatory compounds. Therefore, the discovery of compounds which stimulate the elimination of pathogens without collateral damage of neuronal structures appears an achievable goal. PEA and, with limitations, glatiramer acetate and dimethyl fumarate appear promising candidates. PMID:24904283

  2. Prevention of Immune Cell Apoptosis as Potential Therapeutic Strategy for Severe Infections

    PubMed Central

    Parrino, Janie; Hotchkiss, Richard S.

    2007-01-01

    Some labile cell types whose numbers are normally controlled through programmed cell death are subject to markedly increased destruction during some severe infections. Lymphocytes, in particular, undergo massive and apparently unregulated apoptosis in human patients and laboratory animals with sepsis, potentially playing a major role in the severe immunosuppression that characterizes the terminal phase of fatal illness. Extensive lymphocyte apoptosis has also occurred in humans and animals infected with several exotic agents, including Bacillus anthracis, the cause of anthrax; Yersinia pestis, the cause of plague; and Ebola virus. Prevention of lymphocyte apoptosis, through either genetic modification of the host or treatment with specific inhibitors, markedly improves survival in murine sepsis models. These findings suggest that interventions aimed at reducing the extent of immune cell apoptosis could improve outcomes for a variety of severe human infections, including those caused by emerging pathogens and bioterrorism agents. PMID:17479879

  3. The biogeography of polymicrobial infection

    PubMed Central

    Stacy, Apollo; McNally, Luke; Darch, Sophie E.; Brown, Sam P.; Whiteley, Marvin

    2016-01-01

    Microbial communities are spatially organized in both the environment and the human body. Although patterns exhibited by these communities are described by microbial biogeography this discipline has previously only considered large-scale, global patterns. By contrast, the fine-scale positioning of a pathogen within an infection site can greatly alter its virulence potential. In this Review, we highlight the importance of considering spatial positioning in the study of polymicrobial infections and discuss targeting biogeography as a therapeutic strategy. PMID:26714431

  4. Management strategies for cytomegalovirus infection and disease in solid organ transplant recipients.

    PubMed

    Razonable, Raymund R

    2013-06-01

    Cytomegalovirus is the most common viral pathogen that affects solid organ transplant recipients. It directly causes fever, myelosuppression, and tissue-invasive disease, and indirectly, it negatively impacts allograft and patient survival. Nucleic acid amplification testing is the preferred method to confirm the diagnosis of CMV infection. Prevention of CMV disease using antiviral prophylaxis or preemptive therapy is critical in the management of transplant patients. Intravenous ganciclovir and oral valganciclovir are the first line drugs for antiviral treatment. This article provides a comprehensive review of the current epidemiology, diagnosis, prevention and treatment of CMV infection in solid organ transplant recipients.

  5. Current strategies for the prevention and management of central line-associated bloodstream infections

    PubMed Central

    Han, Zhuolin; Liang, Stephen Y; Marschall, Jonas

    2010-01-01

    Central venous catheters are an invaluable tool for diagnostic and therapeutic purposes in today’s medicine, but their use can be complicated by bloodstream infections (BSIs). While evidence-based preventive measures are disseminated by infection control associations, the optimal management of established central line-associated BSIs has been summarized in infectious diseases guidelines. We prepared an overview of the state-of-the-art of prevention and management of central line-associated BSIs and included topics such as the role of antibiotic-coated catheters, the role of catheter removal in the management, and a review of currently used antibiotic compounds and the duration of treatment. PMID:21694903

  6. [Therapeutics strategies for the management of urinary tract infection in children].

    PubMed

    Launay, E; Bingen, E; Cohen, R

    2012-11-01

    Urinary tract infections is one of the most common bacterial infections in pediatrics The increasing involvement of multiresistant bacteria including E. coli producing extended spectrum ß-lactamase (ESBL) makes its management difficult. The purpose of this article is to evaluate the state of the art and to propose ways of thinking about the management of E. coli urinary tract infection in children. The current percentage (less than 10%) of E. coli strains resistant to third generation cephalosporins and the relative efficiency of the latter, should not led to an immediate change of our protocols. Nevertheless, we should verify as soon as possible susceptibility of E. coli responsible for urinary tract infections and consider other therapeutic options for initial therapy and adaptation after obtaining antibiogram. The use of an aminoglycosid as initial treatment seems very interesting. Aminoglycosides have a very good distribution in the renal parenchyma and are still working on the majority of ESBL-producing bacteria. A rapid oral relay after 48 to 72 hours may be proposed according to the results of the susceptibility with either cotrimoxazole, cefixime, ciprofloxacin or an association cefixime-amoxicilline/clavulanate. The treatment of cystitis due to ESBL E. coli is much less problematic given the good urinary beta-lactam antibiotics diffusion. If clinical improvement occurs, even if antibiogram shows that the strain is resistant to the antibiotic prescribed, it is usually unnecessary to change treatment.

  7. Strategies to Address Infection Prevention and Treatment in the Reduced Inflammatory Milieu of Irrigated Open Wound

    DTIC Science & Technology

    2012-10-01

    debridement, however, removes the body’s first healing response, such as fracture hematoma . We implemented an irrigated radius defect model intended...13. SUPPLEMENTARY NOTES 14. ABSTRACT Open fractures require irrigation and debridement to prevent potential infection. Irrigation and...to represent the open fracture setting with bone loss. We evaluated feasibility to investigate the role of platelet rich plasma (PRP) to restore

  8. Evaluating Clonal Expansion of HIV-Infected Cells: Optimization of PCR Strategies to Predict Clonality

    PubMed Central

    Laskey, Sarah B.; Pohlmeyer, Christopher W.; Bruner, Katherine M.; Siliciano, Robert F.

    2016-01-01

    In HIV-infected individuals receiving suppressive antiretroviral therapy, the virus persists indefinitely in a reservoir of latently infected cells. The proliferation of these cells may contribute to the stability of the reservoir and thus to the lifelong persistence of HIV-1 in infected individuals. Because the HIV-1 replication process is highly error-prone, the detection of identical viral genomes in distinct host cells provides evidence for the clonal expansion of infected cells. We evaluated alignments of unique, near-full-length HIV-1 sequences to determine the relationship between clonality in a short region and clonality in the full genome. Although it is common to amplify and sequence short, subgenomic regions of the viral genome for phylogenetic analysis, we show that sequence identity of these amplicons does not guarantee clonality across the full viral genome. We show that although longer amplicons capture more diversity, no subgenomic region can recapitulate the diversity of full viral genomes. Consequently, some identical subgenomic amplicons should be expected even from the analysis of completely unique viral genomes, and the presence of identical amplicons alone is not proof of clonally expanded HIV-1. We present a method for evaluating evidence of clonal expansion in the context of these findings. PMID:27494508

  9. Agents and strategies in development for improved management of herpes simplex virus infection and disease.

    PubMed

    Kleymann, Gerald

    2005-02-01

    The quiet pandemic of herpes simplex virus (HSV) infections has plagued humanity since ancient times, causing mucocutaneous infection such as herpes labialis and herpes genitalis. Disease symptoms often interfere with every-day activities and occasionally HSV infections are the cause of life-threatening or sight-impairing disease, especially in neonates and the immuno-compromised patient population. After infection the virus persists for life in neurons of the host in a latent form, periodically reactivating and often resulting in significant psychosocial distress for the patient. Currently no cure is available. So far, vaccines, ILs, IFNs, therapeutic proteins, antibodies, immunomodulators and small-molecule drugs with specific or non-specific modes of action lacked either efficacy or the required safety profile to replace the nucleosidic drugs acyclovir, valacyclovir, penciclovir and famciclovir as the first choice of treatment. The recently discovered inhibitors of the HSV helicase-primase are the most potent development candidates today. These antiviral agents act by a novel mechanism of action and display low resistance rates in vitro and superior efficacy in animal models. This review summarises the current therapeutic options, discusses the potential of preclinical or investigational drugs and provides an up-to-date interpretation of the challenge to establish novel treatments for herpes simplex disease.

  10. DNA Persistence and Relapses Questions on the Treatment Strategies of Enterococcus Infections of Prosthetic Valves

    PubMed Central

    Casalta, Jean-Paul; Thuny, Franck; Fournier, Pierre-Edouard; Lepidi, Hubert; Habib, Gilbert; Grisoli, Dominique; Raoult, Didier

    2012-01-01

    We used amplification of the 16S rRNA gene followed by sequencing to evaluate the persistence of bacterial DNA in explanted heart valve tissue as part of the routine work of a clinical microbiology laboratory, and we analyzed the role of this persistence in the relapses observed in our center. We enrolled 286 patients treated for infective endocarditis (IE) who had valve replacement surgery and were diagnosed according to the modified Duke’s criteria described by Li et al. from a total of 579 IE cases treated in our center. The patients were grouped based on the infecting bacteria, and we considered the 4 most common bacterial genus associated with IE separately (144 were caused by Streptococcus spp., 52 by Enterococcus spp., 58 by Staphylococcus aureus and 32 by coagulase-negative Staphylococcus). Based on our cohort, the risk of relapse in patients with enterococcal prosthetic valve infections treated with antibiotics alone was 11%. Bacterial DNA is cleared over time, but this might be a very slow process, especially with Enterococcus spp. Based on a comprehensive review of the literature performed on Medline, most reports still advise combined treatment with penicillin and an aminoglycoside for as long as 4–6 weeks, but there has been no consensus for the treatment of enterococcal infection of prostheses in IE patients. PMID:23300913

  11. Strategies for Coping with Educational and Social Consequences of Chronic Ear Infections in Rural Communities.

    ERIC Educational Resources Information Center

    Pillai, Patrick

    2000-01-01

    Children with chronic ear infections experience a lag time in understanding speech, which inhibits classroom participation and the ability to make friends, and ultimately reduces self-esteem. Difficulty in hearing affects speech and vocabulary development, reading and writing proficiency, and academic performance, and could lead to placement in…

  12. [HTLV 1/2 infection: prenatal performance as a disease control strategy in State of Mato Grosso do Sul].

    PubMed

    Dal Fabbro, Márcia Maria Ferrairo Janini; Cunha, Rivaldo Venâncio da; Bóia, Márcio Neves; Portela, Patrícia; Botelho, Carlos Augusto; Freitas, Gisele Maria Brandão de; Soares, Joana; Ferri, Juliana; Lupion, Juliana

    2008-01-01

    In this study, the prevalence of HTLV 1/2 infection among pregnant women in the State of Mato Grosso do Sul was estimated by means of the ELISA, Western Blot and PCR techniques, in blood samples collected by peripheral venous puncture. 116,689 pregnant women were examined and 153 were diagnosed as presenting HTLV 1/2 infection, with prevalence of 0.13%. Among these 153 pregnant women, 133 (86.9%) had type 1 and 20 (11.1%) had type 2; 73.2% were black, brown or indigenous; about 90% performed domestic activities; and 75.8% (116/153) had been to school for seven years or less. The 153 pregnant women had 172 pregnancies during the study period and 164 pregnancies were followed. Out of pregnancies that were followed, 6.7% (11/164) evolved to abortion, 26.8% (41/153) reported previous abortions and 31.7% (13/41) had had more than two abortions. Comorbidities were found in 17% (26/153), among whom 3.3% (5/153) had HIV (p<0.000002). The authors emphasize the importance of identifying pregnant women with HTLV 1/2 infection, as a strategy for disease control and prevention.

  13. Tobramycin Inhalation Powder (TIP): An Efficient Treatment Strategy for the Management of Chronic Pseudomonas Aeruginosa Infection in Cystic Fibrosis

    PubMed Central

    Lam, John; Vaughan, Steven; Parkins, Michael D.

    2013-01-01

    Repeated bouts of acute and chronic lung infections are responsible for progressive pulmonary function decline in individuals with cystic fibrosis (CF), ultimately leading to respiratory failure and death. Pseudomonas aeruginosa is the archetypical CF pathogen, causes chronic infection in 70% of individuals, and is associated with an accelerated clinical decline. The management of P. aeruginosa in CF has been revolutionized with the development and widespread use of inhaled antibiotics. Aerosol delivery of antimicrobial compounds in CF enables extremely high concentrations of antibiotics to be reached directly at the site of infection potentially overcoming adaptive resistance and avoiding the potential for cumulative systemic toxicities. Tobramycin inhalation powder (TIP) represents the first dry powder inhaled (DPI) antibiotic available for use in CF. DPIs are notable for a markedly reduced time for administration, ease of portability, and increased compliance. TIP has been developed as a therapeutic alternative to tobramycin inhalation solution (TIS), the standard of care for the past 20 years within CF. Relative to TIS 300 mg nebulized twice daily in on-and-off cycles of 28 days duration, TIP 112 mg twice daily via the T-326 inhaler administered on the same schedule is associated with marked time savings, increased patient satisfaction, and comparable clinical end points. TIP represents an innovative treatment strategy for those individuals with CF and holds the promise of increased patient compliance and thus the potential for improved clinical outcomes. PMID:24324354

  14. Pathogenicity and infection strategies of the fire blight pathogen Erwinia amylovora in Rosaceae: state of the art.

    PubMed

    Vrancken, K; Holtappels, M; Schoofs, H; Deckers, T; Valcke, R

    2013-05-01

    Plants are host to a large amount of pathogenic bacteria. Fire blight, caused by the bacterium Erwinia amylovora, is an important disease in Rosaceae. Pathogenicity of E. amylovora is greatly influenced by the production of exopolysaccharides, such as amylovoran, and the use of the type III secretion system, which enables bacteria to penetrate host tissue and cause disease. When infection takes place, plants have to rely on the ability of each cell to recognize the pathogen and the signals emanating from the infection site in order to generate several defence mechanisms. These mechanisms consist of physical barriers and the production of antimicrobial components, both in a preformed and an inducible manner. Inducible defence responses are activated upon the recognition of elicitor molecules by plant cell receptors, either derived from invading micro-organisms or from pathogen-induced degradation of plant tissue. This recognition event triggers a signal transduction cascade, leading to a range of defence responses [reactive oxygen species (ROS), plant hormones, secondary metabolites, …] and redeployment of cellular energy in a fast, efficient and multiresponsive manner, which prevents further pathogen ingress. This review highlights the research that has been performed during recent years regarding this specific plant-pathogen interaction between Erwinia amylovora and Rosaceae, with a special emphasis on the pathogenicity and the infection strategy of E. amylovora and the possible defence mechanisms of the plant against this disease.

  15. Screening strategies to identify new chemical diversity for drug development to treat kinetoplastid infections.

    PubMed

    Don, Rob; Ioset, Jean-Robert

    2014-01-01

    The Drugs for Neglected Diseases initiative (DNDi) has defined and implemented an early discovery strategy over the last few years, in fitting with its virtual R&D business model. This strategy relies on a medium- to high-throughput phenotypic assay platform to expedite the screening of compound libraries accessed through its collaborations with partners from the pharmaceutical industry. We review the pragmatic approaches used to select compound libraries for screening against kinetoplastids, taking into account screening capacity. The advantages, limitations and current achievements in identifying new quality series for further development into preclinical candidates are critically discussed, together with attractive new approaches currently under investigation.

  16. Evaluation of scatter mitigation strategies for x-ray cone-beam CT: impact of scatter subtraction and anti-scatter grids on contrast-to-noise ratio

    NASA Astrophysics Data System (ADS)

    Lazos, Dimitrios; Lasio, Giovanni; Evans, Joshua; Williamson, Jeffrey F.

    2007-03-01

    The large contribution of scatter to cone-beam computed tomography (CBCT) x-ray projections significantly degrades image quality, both through streaking and cupping artifacts and by loss of low contrast boundary detectability. The goal of this investigation is to compare the efficacy of three widely used scatter mitigation methods: subtractive scatter correction (SSC); anti-scatter grids (ASG); and beam modulating with bowtie filters; for improving signal-to-noise ratio (SNR), contrast, contrast-to-noise ratio (CNR) and cupping artifacts. A simple analytic model was developed to predict scatter-to-primary ratio (SPR) and CNR as a function of cylindrical phantom thickness. In addition, CBCT x-ray projections of a CatPhan QA phantom were measured, using a Varian CBCT imaging system, and computed, using an inhouse Monte Carlo photon-transport code to more realistically evaluate the impact of scatter mitigation techniques. Images formed with uncorrected sinograms acquired without ASGs and bow-tie filter show pronounced cupping artifacts and loss of contrast. Subtraction of measured scatter profiles restores image uniformity and CT number accuracy, but does not improve CNR, since the improvement in contrast almost exactly offset by the increase in relative x-ray noise. ASGs were found to modestly improve CNR (up to 20%, depending ASG primary transmission and selectivity) only in body scans, while they can reduce CNR for head phantoms where SPR is low.

  17. Psychological Stressors and Coping Strategies Used by Adolescents Living with and Not Living with Hiv Infection in Nigeria.

    PubMed

    Folayan, Morenike O; Cáceres, Carlos F; Sam-Agudu, Nadia A; Odetoyinbo, Morolake; Stockman, Jamila K; Harrison, Abigail

    2016-09-07

    Little is known about stressful triggers and coping strategies of Nigerian adolescents and whether or not, and how, HIV infection modulates these sources of stress and coping. This study evaluated differences in stressors and coping strategies among Nigerian adolescents based on HIV status. We analysed the data of six hundred 10-19 year old adolescents recruited through a population-based survey from 12 States of Nigeria who self-reported their HIV status. Data on stressors and coping strategies were retrieved by self-report from participants, using a validated structured questionnaire. We compared results between adolescents with and without HIV with respect to identification of specific life events as stressors, and use of specific coping strategies to manage stress. Logistic regression analysis adjusted for age and sex. Adolescents living with HIV (ALHIV) had significantly increased odds of identifying 'having to visit the hospital regularly' (AOR: 5.85; 95 % CI: 2.11-16.20; P = 0.001), and 'having to take drugs regularly' (AOR: 9.70; 95 % CI: 4.13-22.81; P < 0.001) as stressors; and 'Seeking social support' (AOR: 3.14; 95 % CI: 1.99-4.93; p < 0.001) and 'using mental disengagement' (OR: 1.64; 95 % CI: 0.49-1.84; p = 0.001) as coping strategies. Adolescents not living with HIV had significantly increased odds of identifying 'argument with a friend or family member' as a stressor (AOR: 6.59; 95 % CI: 3.62-11.98; P < 0.001). Life events related to adolescents' HIV positive status were significant stressors for ALHIV. Providing targeted psychosocial support could help reduce the impact of such HIV status-related stressors on ALHIV.

  18. Contrast cystography.

    PubMed

    Essman, Stephanie C

    2005-02-01

    Cystography is a radiographic study performed to aid in evaluation of the urinary bladder for extramural, mural, or intraluminal lesions. These lesions may primarily involve the urinary bladder or may be an extension of disease from adjacent organs. Cystography is easy to perform with relatively few complications. Different types of cystography (positive versus negative contrast) may be used depending on the type of information that the clinician hopes to obtain. Although a valuable technique, it is important to correlate the findings on cystography with other clinical information to arrive at the final diagnosis.

  19. Helicobacter Pylori Infection: Diagnostic Strategies in Primary Diagnosis and After Therapy.

    PubMed

    Atkinson, Nathan S S; Braden, Barbara

    2016-01-01

    Accurate diagnosis of Helicobacter pylori infection pre- and post-treatment is mandatory in the current era of decreasing prevalence and increasing antibiotic resistance. The diagnostic performance of most tests is poorer in clinical situations with low bacterial density which is seen in conditions such as atrophic gastritis or intake of antisecretory and antibiotic medications. Noninvasive tests require less cost and resource but provide excellent accuracy; however, endoscopy with testing of gastric biopsy specimens is indicated where alarming symptoms are present or antibiotic susceptibility testing by culture is desired. Newer modalities such as polymerase chain reaction testing provide additional virulence and antibiotic sensitivity profiling. This article outlines new developments and the key parameters of each test, as careful selection of test modality within the clinical context is required for adequate management of infected symptomatic patients.

  20. Microbiome manipulation with faecal microbiome transplantation as a therapeutic strategy in Clostridium difficile infection.

    PubMed

    Mullish, B H; Marchesi, J R; Thursz, M R; Williams, H R T

    2015-05-01

    Faecal microbiome transplantation (FMT) has generated huge recent interest as it presents a potential solution to a significant clinical problem--the increasing incidence of Clostridium difficile infection (CDI). In the short term, however, there remain many practical questions regarding its use, including the optimal selection of donors, material preparation and the mechanics of delivery. In the longer term, enhanced understanding of the mechanisms of action of FMT may potentiate novel therapies, such as targeted manipulation of the microbiome in CDI and beyond.

  1. A multivalent vaccination strategy for the prevention of Old World arenavirus infection in humans.

    PubMed

    Botten, Jason; Whitton, J Lindsay; Barrowman, Polly; Sidney, John; Whitmire, Jason K; Alexander, Jeff; Kotturi, Maya F; Sette, Alessandro; Buchmeier, Michael J

    2010-10-01

    Arenaviruses cause severe human disease ranging from aseptic meningitis following lymphocytic choriomeningitis virus (LCMV) infection to hemorrhagic fever syndromes following infection with Guanarito virus (GTOV), Junin virus (JUNV), Lassa virus (LASV), Machupo virus (MACV), Sabia virus (SABV), or Whitewater Arroyo virus (WWAV). Cellular immunity, chiefly the CD8(+) T-cell response, plays a critical role in providing protective immunity following infection with the Old World arenaviruses LASV and LCMV. In the current study, we evaluated whether HLA class I-restricted epitopes that are cross-reactive among pathogenic arenaviruses could be identified for the purpose of developing an epitope-based vaccination approach that would cross-protect against multiple arenaviruses. We were able to identify a panel of HLA-A*0201-restricted peptides derived from the same region of the glycoprotein precursor (GPC) of LASV (GPC spanning residues 441 to 449 [GPC(441-449)]), LCMV (GPC(447-455)), JUNV (GPC(429-437)), MACV (GPC(444-452)), GTOV (GPC(427-435)), and WWAV (GPC(428-436)) that displayed high-affinity binding to HLA-A*0201 and were recognized by CD8(+) T cells in a cross-reactive manner following LCMV infection or peptide immunization of HLA-A*0201 transgenic mice. Immunization of HLA-A*0201 mice with the Old World peptide LASV GPC(441-449) or LCMV GPC(447-455) induced high-avidity CD8(+) T-cell responses that were able to kill syngeneic target cells pulsed with either LASV GPC(441-449) or LCMV GPC(447-455) in vivo and provided significant protection against viral challenge with LCMV. Through this study, we have demonstrated that HLA class I-restricted, cross-reactive epitopes exist among diverse arenaviruses and that individual epitopes can be utilized as effective vaccine determinants for multiple pathogenic arenaviruses.

  2. Management strategies for infected total hip arthroplasty. A critical appreciation of problems and techniques.

    PubMed

    Karachalios, Theofilos; Koutalos, Antonios; Komnos, George

    2014-10-02

    Infection is a devastating complication of total hip arthroplasty (THA). Risk factors have been recognised and prevention is possible. The nature of the disease is heterogeneous and for satisfactory management one has to weigh factors related to pathogen, host, local soft tissue, bone stock, surgeon experience and financial resources. Available data in the current literature is of poor quality and there is a lack of data comparing different techniques. Referral of patients to dedicated departments with the appropriate facilities may be more appropriate.

  3. Efficacy of oral ribavirin in hematologic disease patients with paramyxovirus infection: analytic strategy using propensity scores.

    PubMed

    Park, So-Youn; Baek, Seunghee; Lee, Sang-Oh; Choi, Sang-Ho; Kim, Yang Soo; Woo, Jun Hee; Sung, Heungsup; Kim, Mi-Na; Kim, Dae-Young; Lee, Jung-Hee; Lee, Je-Hwan; Lee, Kyoo-Hyung; Kim, Sung-Han

    2013-02-01

    Few antiviral agents are available for treating paramyxovirus infections, such as those involving respiratory syncytial virus (RSV), parainfluenza virus (PIV), and human metapneumovirus (hMPV). We evaluated the effect of oral ribavirin on clinical outcomes of paramyxovirus infections in patients with hematological diseases. All adult patients with paramyxovirus were retrospectively reviewed over a 2-year period. Patients who received oral ribavirin were compared to those who received supportive care without ribavirin therapy. A propensity-matched case-control study and a logistic regression model with inverse probability of treatment weighting (IPTW) were performed to reduce the effect of selection bias in assignment for oral ribavirin therapy. A total of 145 patients, including 64 (44%) with PIV, 60 (41%) with RSV, and 21 (15%) with hMPV, were analyzed. Of these 145 patients, 114 (78%) received oral ribavirin and the remaining 31 (21%) constituted the nonribavirin group. Thirty-day mortality and underlying respiratory death rates were 31% (35/114) and 12% (14/114), respectively, for the oral ribavirin group versus 19% (6/31) and 16% (5/31), respectively, for the nonribavirin group (P = 0.21 and P = 0.56). In the case-control study, the 30-day mortality rate in the ribavirin group was 24% (5/21) versus 19% (4/21) in the nonribavirin group (P = 0.71). In addition, the logistic regression model with IPTW revealed no significant difference in 30-day mortality (adjusted hazard ratio of 1.3; 95% confidence interval [95% CI] of 0.3 to 5.8) between the two groups. Steroid use (adjusted odds ratio, 5.67; P = 0.01) and upper respiratory tract infection (adjusted odds ratio, 0.07; P = 0.001) was independently associated with mortality. Our data suggest that oral ribavirin therapy may not improve clinical outcomes in hematologic disease patients infected with paramyxovirus.

  4. Vaccine and antiviral strategies against infections caused by human immunodeficiency virus.

    PubMed Central

    Wainberg, M A; Kendall, O; Gilmore, N

    1988-01-01

    Human immunodeficiency virus type 1 (HIV-1) has been clearly associated with a variety of new illnesses, including profound immunodeficiency (acquired immune deficiency syndrome [AIDS]), wasting syndromes (formerly termed AIDS-related complex [ARC]) and neurologic syndromes, including neuropathy, myelopathy and encephalopathy (often termed subacute encephalitis or AIDS dementia complex). HIV-1 preferentially infects T lymphocytes by binding to a membrane receptor protein, CD4, associated with helper function. The virus can also attack macrophages and, possibly, other cells such as neuronal cells, colonic epithelial cells and B lymphocytes. Infection of macrophages or monocytes may be involved in neurologic disease. Knowledge about HIV-1 has rapidly increased, and investigators have characterized its structure, ways in which it infects cells, replicates and is cytopathic for certain cells, and how the immune system responds to it. The ideal vaccine would prevent adsorption of the virus into the cell, but it is difficult to develop stable resistance because the virus has many antigenic patterns and mutates frequently. The results of vaccine trials in animals have not been promising, but work is being done with monoclonal antibodies. Antiviral therapies being investigated include those to prevent virus binding and entry, to inhibit reverse transcription, to inhibit the virus's life cycle and to restore immune competence in immunocompromised patients. PMID:3282628

  5. Innate gamma/delta T-cells during HIV infection: Terra relatively Incognita in novel vaccination strategies?

    PubMed

    Agrati, Chiara; D'Offizi, Gianpiero; Gougeon, Marie-Lise; Malkovsky, Miroslav; Sacchi, Alessandra; Casetti, Rita; Bordoni, Veronica; Cimini, Eleonora; Martini, Federico

    2011-01-01

    Despite a long-lasting global effort, the Holy Grail quest for a protective vaccine, able to confer prevention to HIV infection, did not reach the hoped for results, nor seems able to do so in the near future. Since mucosal surfaces of the host serve as the main entry point for HIV, it seems now logical to switch from a systemic to a localized view of events, in order to reveal critical steps useful in designing new and different vaccination strategies. In this context, the recent description of the very early phases of infection, from the eclipse to the viremia peak phase, seems to define a point-of-no-return threshold after which the main HIV infection steps, i.e. the massive destruction of the CD4+CCR5+ cell pool, the destruction of the mucosal physical barrier, and the establishment of reservoir sanctuaries, have already been accomplished. Nevertheless, the underlying mechanisms, the timing, and the consequences of evasion mechanisms exploited by HIV are still under scrutiny. Innate immunity, as part of a rapid lymphoid stress surveillance system, is known to play a central role in host responses to many infectious agents. In particular, Vγ9Vδ2 T-cells are able to quickly respond to danger signals without the need for classical major histocompatibility complex presentation, and may act as a bridge between innate and acquired arms of immune response, being able to kill infected/transformed cells, release antimicrobial soluble factors, and increase the deployment of other innate and acquired responses. Many experimental evidences suggest a direct role of circulating Vγ9Vδ2 T-cells during HIV disease. They may exert a direct anti-HIV role by secreting chemokines competing for HIV entry coreceptors as well as other soluble antiviral factors, and by killing infected cells by cytotoxic natural killer-like mechanisms. Moreover, they were found progressively depleted and anergic in advanced stages of HIV disease, this effect being directly linked to uncontrolled

  6. Comparing different maize supplementation strategies to improve resilience and resistance against gastrointestinal nematode infections in browsing goats

    PubMed Central

    Gárate-Gallardo, Leslie; Torres-Acosta, Juan Felipe de Jesús; Aguilar-Caballero, Armando Jacinto; Sandoval-Castro, Carlos Alfredo; Cámara-Sarmiento, Ramón; Canul-Ku, Hilda Lorena

    2015-01-01

    The effect of maize grain supplementation on the resilience and resistance of browsing Criollo goat kids against gastrointestinal nematodes was evaluated. Five-month-old kids (n = 42), raised worm-free, were allocated to five groups: infected + not supplemented (I-NS; n = 10), infected + maize supplement at 108 g/d (I-S108; n = 8), maize supplement at 1% of body weight (BW) (I-S1%; n = 8), maize supplement at 1.5% BW (I-S1.5%; n = 8), or infected + supplemented (maize supplement 1.5% BW) + moxidectin (0.2 mg/kg BW subcutaneously every 28 d) (T-S1.5%; n = 8). Kids browsed daily (7 h) in a tropical forest for 112 days during the rainy season. Kids were weighed weekly to adjust supplementary feeding. Hematocrit (Ht), hemoglobin (Hb), and eggs per gram of feces were determined fortnightly. On day 112, five goat kids were slaughtered per group to determine worm burdens. Kids of the I-S1.5% group showed similar body-weight change, Ht and Hb, compared to kids without gastrointestinal nematodes (T-S1.5%), as well as lower eggs per gram of feces and Trichostrongylus colubriformis worm burden compared to the I-NS group (P > 0.05). Thus, among the supplement levels tested, increasing maize supplementation at 1.5% BW of kids was the best strategy to improve their resilience and resistance against natural gastrointestinal nematode infections under the conditions of forage from the tropical forest. PMID:26071051

  7. Comparing different maize supplementation strategies to improve resilience and resistance against gastrointestinal nematode infections in browsing goats.

    PubMed

    Gárate-Gallardo, Leslie; Torres-Acosta, Juan Felipe de Jesús; Aguilar-Caballero, Armando Jacinto; Sandoval-Castro, Carlos Alfredo; Cámara-Sarmiento, Ramón; Canul-Ku, Hilda Lorena

    2015-01-01

    The effect of maize grain supplementation on the resilience and resistance of browsing Criollo goat kids against gastrointestinal nematodes was evaluated. Five-month-old kids (n = 42), raised worm-free, were allocated to five groups: infected + not supplemented (I-NS; n = 10), infected + maize supplement at 108 g/d (I-S108; n = 8), maize supplement at 1% of body weight (BW) (I-S1%; n = 8), maize supplement at 1.5% BW (I-S1.5%; n = 8), or infected + supplemented (maize supplement 1.5% BW) + moxidectin (0.2 mg/kg BW subcutaneously every 28 d) (T-S1.5%; n = 8). Kids browsed daily (7 h) in a tropical forest for 112 days during the rainy season. Kids were weighed weekly to adjust supplementary feeding. Hematocrit (Ht), hemoglobin (Hb), and eggs per gram of feces were determined fortnightly. On day 112, five goat kids were slaughtered per group to determine worm burdens. Kids of the I-S1.5% group showed similar body-weight change, Ht and Hb, compared to kids without gastrointestinal nematodes (T-S1.5%), as well as lower eggs per gram of feces and Trichostrongylus colubriformis worm burden compared to the I-NS group (P > 0.05). Thus, among the supplement levels tested, increasing maize supplementation at 1.5% BW of kids was the best strategy to improve their resilience and resistance against natural gastrointestinal nematode infections under the conditions of forage from the tropical forest.

  8. Tomato Infection by Whitefly-Transmitted Circulative and Non-Circulative Viruses Induce Contrasting Changes in Plant Volatiles and Vector Behaviour

    PubMed Central

    Fereres, Alberto; Peñaflor, Maria Fernanda G. V.; Favaro, Carla F.; Azevedo, Kamila E. X.; Landi, Carolina H.; Maluta, Nathalie K. P.; Bento, José Mauricio S.; Lopes, Joao R.S.

    2016-01-01

    Virus infection frequently modifies plant phenotypes, leading to changes in behaviour and performance of their insect vectors in a way that transmission is enhanced, although this may not always be the case. Here, we investigated Bemisia tabaci response to tomato plants infected by Tomato chlorosis virus (ToCV), a non-circulative-transmitted crinivirus, and Tomato severe rugose virus (ToSRV), a circulative-transmitted begomovirus. Moreover, we examined the role of visual and olfactory cues in host plant selection by both viruliferous and non-viruliferous B. tabaci. Visual cues alone were assessed as targets for whitefly landing by placing leaves underneath a Plexiglas plate. A dual-choice arena was used to assess whitefly response to virus-infected and mock-inoculated tomato leaves under light and dark conditions. Thereafter, we tested the whitefly response to volatiles using an active air-flow Y-tube olfactometer, and chemically characterized the blends using gas chromatography coupled to mass spectrometry. Visual stimuli tests showed that whiteflies, irrespective of their infectious status, always preferred to land on virus-infected rather than on mock-inoculated leaves. Furthermore, whiteflies had no preference for either virus-infected or mock-inoculated leaves under dark conditions, but preferred virus-infected leaves in the presence of light. ToSRV-infection promoted a sharp decline in the concentration of some tomato volatiles, while an increase in the emission of some terpenes after ToCV infection was found. ToSRV-viruliferous whiteflies preferred volatiles emitted from mock-inoculated plants, a conducive behaviour to enhance virus spread, while volatiles from ToCV-infected plants were avoided by non-viruliferous whiteflies, a behaviour that is likely detrimental to the secondary spread of the virus. In conclusion, the circulative persistent begomovirus, ToSRV, seems to have evolved together with its vector B. tabaci to optimise its own spread. However

  9. Infection prevention and control of Clostridium difficile: a global review of guidelines, strategies, and recommendations

    PubMed Central

    Balsells, Evelyn; Filipescu, Teodora; Kyaw, Moe H.; Wiuff, Camilla; Campbell, Harry; Nair, Harish

    2016-01-01

    Background Clostridium difficile is the leading cause of health care–associated infections. Given the high incidence of C. difficile infection (CDI) and the lack of primary prevention through immunization, health care professionals should be aware of the most current guidance, as well as strengths and limitations of the evidence base underpinning this guidance. Methods We identified publicly available national or organizational guidelines related to CDI infection and prevention control (IPC) published between 2000 and 2015 and for any health care setting through an internet search using the Google search engine. We reviewed CDI–targeted IPC recommendations and describe the assessment of evidence in available guidelines. Results We identified documents from 28 countries/territories, mainly from acute care hospitals in North America, the Western Pacific, and Europe (18 countries). We identified only a few specific recommendations for long–term care facilities (LTCFs) and from countries in South America (Uruguay and Chile), South East Asia (Thailand), and none for Africa or Eastern Mediterranean. Of 10 IPC areas, antimicrobial stewardship was universally recognized as essential and supported by high quality evidence. Five other widely reported “strong” recommendations were: effective environment cleaning (including medical equipment), case isolation, use of personal protective equipment, surveillance, and education. Several unresolved and emerging issues were documented and currently available evidence was classified mainly as of mixed quality. Conclusion Our review underlines the need for targeted CDI IPC guidelines in several countries and for LTCFs. International harmonisation on the assessment of the evidence for best practices is needed as well as more robust evidence to support targeted recommendations. PMID:28028434

  10. Disseminated Nocardiosis: A Successful Blind Strategy of Treatment in an HIV Infected Patient.

    PubMed

    Guerra, Ana C; Batista, Dário; Aleixo, Maria J; Saraiva, Paulo; Aguas, Maria J

    2015-01-01

    Background. Nocardiosis is a rare disease that mainly affects severely immunocompromised patients. Symptoms are nonspecific and microbiological isolation is difficult, hiding the diagnosis. Treatment should be guided by species and susceptibility testing. Findings. We report a clinical case of a disseminated nocardiosis in a patient with HIV and HVB infections. Interpretation. Diagnosis should be presumed early and microbiological conditions should be optimized, in order to identify the species and achieve antibiotic susceptibility testing. This is a very important step to choose an effective therapeutic regimen or alternative options.

  11. Disseminated Nocardiosis: A Successful Blind Strategy of Treatment in an HIV Infected Patient

    PubMed Central

    Guerra, Ana C.; Aleixo, Maria J.; Saraiva, Paulo; Aguas, Maria J.

    2015-01-01

    Background. Nocardiosis is a rare disease that mainly affects severely immunocompromised patients. Symptoms are nonspecific and microbiological isolation is difficult, hiding the diagnosis. Treatment should be guided by species and susceptibility testing. Findings. We report a clinical case of a disseminated nocardiosis in a patient with HIV and HVB infections. Interpretation. Diagnosis should be presumed early and microbiological conditions should be optimized, in order to identify the species and achieve antibiotic susceptibility testing. This is a very important step to choose an effective therapeutic regimen or alternative options. PMID:25821611

  12. TU-G-204-04: A Unified Strategy for Bi-Factorial Optimization of Radiation Dose and Contrast Dose in CT Imaging

    SciTech Connect

    Sahbaee, P; Zhang, Y; Solomon, J; Becchetti, M; Segars, P; Samei, E

    2015-06-15

    Purpose: To substantiate the interdependency of contrast dose, radiation dose, and image quality in CT towards the patient- specific optimization of the imaging protocols Methods: The study deployed two phantom platforms. A variable sized (12, 18, 23, 30, 37 cm) phantom (Mercury-3.0) containing an iodinated insert (8.5 mgI/ml) was imaged on a representative CT scanner at multiple CTDI values (0.7–22.6 mGy). The contrast and noise were measured from the reconstructed images for each phantom diameter. Linearly related to iodine-concentration, contrast-to-noise ratio (CNR), were calculated for 16 iodine-concentration levels (0–8.5 mgI/ml). The analysis was extended to a recently developed suit of 58 virtual human models (5D XCAT) with added contrast dynamics. Emulating a contrast-enhanced abdominal image procedure and targeting a peak-enhancement in aorta, each XCAT phantom was “imaged” using a simulation platform (CatSim, GE). 3D surfaces for each patient/size established the relationship between iodine-concentration, dose, and CNR. The ratios of change in iodine-concentration versus dose (IDR) to yield a constant change in CNR were calculated for each patient size. Results: Mercury phantom results show the image-quality size- dependence on CTDI and IC levels. For desired image-quality values, the iso-contour-lines reflect the trade off between contrast-material and radiation doses. For a fixed iodine-concentration (4 mgI/mL), the IDR values for low (1.4 mGy) and high (11.5 mGy) dose levels were 1.02, 1.07, 1.19, 1.65, 1.54, and 3.14, 3.12, 3.52, 3.76, 4.06, respectively across five sizes. The simulation data from XCAT models confirmed the empirical results from Mercury phantom. Conclusion: The iodine-concentration, image quality, and radiation dose are interdependent. The understanding of the relationships between iodine-concentration, image quality, and radiation dose will allow for a more comprehensive optimization of CT imaging devices and techniques

  13. Reducing unnecessary urinary catheter use and other strategies to prevent catheter-associated urinary tract infection: an integrative review

    PubMed Central

    Meddings, Jennifer; Rogers, Mary A M; Krein, Sarah L; Fakih, Mohamad G; Olmsted, Russell N; Saint, Sanjay

    2014-01-01

    Background Catheter-associated urinary tract infections (CAUTI) are costly, common and often preventable by reducing unnecessary urinary catheter (UC) use. Methods To summarise interventions to reduce UC use and CAUTIs, we updated a prior systematic review (through October 2012), and a meta-analysis regarding interventions prompting UC removal by reminders or stop orders. A narrative review summarises other CAUTI prevention strategies including aseptic insertion, catheter maintenance, antimicrobial UCs, and bladder bundle implementation. Results 30 studies were identified and summarised with interventions to prompt removal of UCs, with potential for inclusion in the meta-analyses. By meta-analysis (11 studies), the rate of CAUTI (episodes per 1000 catheter-days) was reduced by 53% (rate ratio 0.47; 95% CI 0.30 to 0.64, p<0.001) using a reminder or stop order, with five studies also including interventions to decrease initial UC placement. The pooled (nine studies) standardised mean difference (SMD) in catheterisation duration (days) was −1.06 overall (p=0.065) including a statistically significant decrease in stop-order studies (SMD −0.37; p<0.001) but not in reminder studies (SMD, −1.54; p=0.071). No significant harm from catheter removal strategies is supported. Limited research is available regarding the impact of UC insertion and maintenance technique. A recent randomised controlled trial indicates antimicrobial catheters provide no significant benefit in preventing symptomatic CAUTIs. Conclusions UC reminders and stop orders appear to reduce CAUTI rates and should be used to improve patient safety. Several evidence-based guidelines have evaluated CAUTI preventive strategies as well as emerging evidence regarding intervention bundles. Implementation strategies are important because reducing UC use involves changing well-established habits. PMID:24077850

  14. Avian influenza viruses that cause highly virulent infections in humans exhibit distinct replicative properties in contrast to human H1N1 viruses

    NASA Astrophysics Data System (ADS)

    Simon, Philippe F.; de La Vega, Marc-Antoine; Paradis, Éric; Mendoza, Emelissa; Coombs, Kevin M.; Kobasa, Darwyn; Beauchemin, Catherine A. A.

    2016-04-01

    Avian influenza viruses present an emerging epidemiological concern as some strains of H5N1 avian influenza can cause severe infections in humans with lethality rates of up to 60%. These have been in circulation since 1997 and recently a novel H7N9-subtyped virus has been causing epizootics in China with lethality rates around 20%. To better understand the replication kinetics of these viruses, we combined several extensive viral kinetics experiments with mathematical modelling of in vitro infections in human A549 cells. We extracted fundamental replication parameters revealing that, while both the H5N1 and H7N9 viruses replicate faster and to higher titers than two low-pathogenicity H1N1 strains, they accomplish this via different mechanisms. While the H7N9 virions exhibit a faster rate of infection, the H5N1 virions are produced at a higher rate. Of the two H1N1 strains studied, the 2009 pandemic H1N1 strain exhibits the longest eclipse phase, possibly indicative of a less effective neuraminidase activity, but causes infection more rapidly than the seasonal strain. This explains, in part, the pandemic strain’s generally slower growth kinetics and permissiveness to accept mutations causing neuraminidase inhibitor resistance without significant loss in fitness. Our results highlight differential growth properties of H1N1, H5N1 and H7N9 influenza viruses.

  15. In the United States, negligible rates of zoonotic sarcocystosis occur in feral swine that, by contrast, frequently harbour infections with Sarcocystis miescheriana, a related parasite contracted from canids.

    PubMed

    Calero-Bernal, R; Verma, S K; Oliveira, S; Yang, Y; Rosenthal, B M; Dubey, J P

    2015-04-01

    Transmission of pathogens between domestic and wild life animals plays an important role in epidemiology. Feral pig populations are increasing and expanding in the USA, and may constitute a risk to non-biosecure domestic pig facilities by serving as reservoirs for pathogens. We surveyed, for Sarcocystis infection, the myocardium of 1006 feral pigs (Sus scrofa) trapped or hunted in 29 states during the Comprehensive Feral Swine Disease Surveillance Program of the USDA's Animal and Plant Health Inspection Service, Wildlife Services unit during 2012-2014. Sarcocysts were detected in histological sections of 25% (251/1006) of myocardium with an average parasitic load/intensity of infection of 3.03 sarcocysts/section (1.5×0.7 cm), and higher prevalence of myocarditis in severe infections. Microscopic examination of pepsin digests of 147 hearts revealed a higher prevalence of Sarcocystis bradyzoites (49%, 72/147) than when diagnosed by histology. A fragment of Sarcocystis 18S rRNA was amplified and digested with a restriction endonuclease, revealing a pattern consistent with Sarcocystis miescheriana in all 44 selected samples. Sequencing 31 of these 44 isolates confirmed their correspondence to S. miescheriana. Thus, S. miescheriana infection, but not the zoonotic parasite Sarcocystis suihominis, appears to be prevalent and widespread in feral pigs in the USA.

  16. Avian influenza viruses that cause highly virulent infections in humans exhibit distinct replicative properties in contrast to human H1N1 viruses

    PubMed Central

    Simon, Philippe F.; de La Vega, Marc-Antoine; Paradis, Éric; Mendoza, Emelissa; Coombs, Kevin M.; Kobasa, Darwyn; Beauchemin, Catherine A. A.

    2016-01-01

    Avian influenza viruses present an emerging epidemiological concern as some strains of H5N1 avian influenza can cause severe infections in humans with lethality rates of up to 60%. These have been in circulation since 1997 and recently a novel H7N9-subtyped virus has been causing epizootics in China with lethality rates around 20%. To better understand the replication kinetics of these viruses, we combined several extensive viral kinetics experiments with mathematical modelling of in vitro infections in human A549 cells. We extracted fundamental replication parameters revealing that, while both the H5N1 and H7N9 viruses replicate faster and to higher titers than two low-pathogenicity H1N1 strains, they accomplish this via different mechanisms. While the H7N9 virions exhibit a faster rate of infection, the H5N1 virions are produced at a higher rate. Of the two H1N1 strains studied, the 2009 pandemic H1N1 strain exhibits the longest eclipse phase, possibly indicative of a less effective neuraminidase activity, but causes infection more rapidly than the seasonal strain. This explains, in part, the pandemic strain’s generally slower growth kinetics and permissiveness to accept mutations causing neuraminidase inhibitor resistance without significant loss in fitness. Our results highlight differential growth properties of H1N1, H5N1 and H7N9 influenza viruses. PMID:27080193

  17. A comparison of ionic versus nonionic contrast medium during primary percutaneous transluminal coronary angioplasty for acute myocardial infarction (GUSTO IIb). Global Use of Strategies to Open Occluded Coronary Arteries in Acute Coronary Syndromes.

    PubMed

    Batchelor, W B; Granger, C B; Kleiman, N S; Phillips, H R; Ellis, S G; Betriu, A; Criger, D A; Stebbins, A L; Topol, E J; Califf, R M

    2000-03-15

    The clinical impact of contrast medium selection during primary percutaneous transluminal coronary angioplasty for acute myocardial infarction (AMI) has not been studied. We compared the clinical outcomes of patients who received ionic versus nonionic low osmolar contrast medium in the setting of primary percutaneous transluminal coronary angioplasty for AMI in the second Global Use of Strategies to Open Occluded Coronary Arteries in Acute Coronary Syndromes (GUSTO IIb) trial. Univariable and multivariable analyses were performed to assess the relation between contrast medium selection and clinical outcome (death, reinfarction, or refractory ischemia) at 30 days. Although baseline clinical and angiographic characteristics were generally similar between the 2 groups, patients who received ionic, low osmolar contrast were less likely to have been enrolled at a US site (23% vs 43%, p = 0.001) and less likely to have occlusion of the left anterior descending coronary artery (34% vs 47%, p = 0.03) or a history of prior AMI (8% vs 16%, p = 0.02). The triple composite end point of death, reinfarction, or refractory ischemia occurred less frequently in the ionic group, both in the hospital (4.4% vs 11%, p = 0.018) and at 30 days (5.5% vs 11%, p = 0.044). Although the trend favoring ionic contrast persisted, the differences were no longer statistically significant after adjustment for imbalances in baseline characteristics using a risk model developed from the study sample (n = 454, adjusted odds ratio for ionic contrast 0.48 [0.22 to 1.02], p = 0.055), and using a model developed from the entire GUSTO IIb study cohort (n = 12,142, adjusted odds ratio for ionic contrast 0.50 [0.23 to 1.06], p = 0.072). The results of this observational study warrant further elucidation by a randomized study design in this setting.

  18. [Prevention strategies for methicillin-resistant Staphylococcus aureus (MRSA) infections in Latin America].

    PubMed

    Alvarez, Carlos; Labarca, Jaime; Salles, Mauro

    2010-08-01

    After the first reports of the emergence of MRSA in the 1970s, numerous measures intended to prevent its transmission were initiated in hospitals. However, in most cases, large-scale measures failed to be implemented and the transmission of MRSA has since led to a global pandemic. Presently, doubts still remain about the best approach to prevent and control MRSA and more often than not, control measures are not implemented. Therefore, we review here the current situation in Latin America with respect to existing policies for control of MRSA, and evaluate the evidence for control measures in hospitals and the community. We look at the risk factors for infection and transmission of MRSA between hospital patients and within specific populations in the community, and at the effect of antibiotic usage on the spread of MRSA in these settings. Finally, we summarize recommendations for the prevention and control of MRSA, which can be applied to the Latin American hospital environment and community setting.

  19. Excellence in sexually transmitted infection (STI) diagnostics: recognition of past successes and strategies for the future

    PubMed Central

    Ronald, A; Kuypers, J; Lukehart, S A; Peeling, R W; Pope, V

    2006-01-01

    Diagnostic advances do not generally receive the recognition given to prevention and treatment contributions, for the control and management of infectious diseases including sexually transmitted infections (STIs). In order to identify seminal diagnostic contributions over a half century (1950–2000), the Editorial Board of the WHO Sexually Transmitted Diseases Diagnostics Initiative (SDI) Publication Review or “electronic journal club” were asked to nominate their choices of peer‐reviewed publications for special recognition. From 43 nominations, 13 were voted by a panel of 25 “experts” as having made the most significant contributions. The 1964 article by Thayer and Martin, which identified a selective media for gonococcal culture, was chosen unanimously by all panel members and is identified as the classic STI diagnostic article for this era. PMID:17135329

  20. Therapeutic strategies underpinning the development of novel techniques for the treatment of HIV infection

    PubMed Central

    Tan, Jian J.; Cong, Xiao J.; Hu, Li M.; Wang, Cun X.; Jia, Lee; Liang, Xing-Jie

    2010-01-01

    The HIV replication cycle offers multiple targets for chemotherapeutic intervention, including the viral exterior envelope glycoprotein, gp120; viral co-receptors CXCR4 and CCR5; transmembrane glycoprotein, gp41; integrase; reverse transcriptase; protease and so on. Most currently used anti-HIV drugs are reverse transcriptase inhibitors or protease inhibitors. The expanding application of simulation to drug design combined with experimental techniques have developed a large amount of novel inhibitors that interact specifically with targets besides transcriptase and protease. This review presents details of the anti-HIV inhibitors discovered with computer-aided approaches and provides an overview of the recent five-year achievements in the treatment of HIV infection and the application of computational methods to current drug design. PMID:20096804

  1. Novel Nanotechnology Strategies for the Treatment and Prevention of HIV Infection

    NASA Astrophysics Data System (ADS)

    Tan, Jian Jun; Sun, Xiao Hui; Ma, Xue Ting; Guan, Jian Qing; Wang, Cun Xin

    2013-09-01

    It is a hard work to develop an hightly effective cure and prevention of HIV/AIDS. The widespread used of some therapy approaches such as highly active anti retroviral therapy (HAART) has improved life quality and span of infected individuals. However, some limitations of these approaches prevent them achieving further advancement. Recent research on drug delivery approaches indicates that engineered nanosystems may bring positive effect on the improvement of current antiretroviral therapy. Furthermore, the basic researches of nanotechnology- based systems which prevent HIV transmission have been started. Therefore, nanotechnology may become a potential approach in the field of HIV/AIDS treatment and prevention. This chapter reviews the latest advancement in the field of nanotechnology-based systems which improve the fields of HIV/AIDS treatment and prevention.

  2. Prevalence and mitigation strategies of HIV/AIDS infection risks in Namibian tertiary education institutional hostels.

    PubMed

    Zimba, Roderick F; Likando, Gilbert N

    2014-01-01

    The purpose of this study was to investigate risk factors that could promote HIV infection amongst adolescents and young adults living in tertiary educational institutional hostels in Namibia. Employing structured questionnaires and focus group discussions, we sought to answer questions pertaining to factors, beliefs systems, values, traditions and sexual relations that could promote HIV infection in the student hostels. The data on these issues were gathered from 306 male and 314 female students aged 18-35 years living in eight hostels. Amongst other results, the data revealed that sexual promiscuity in the hostels was treated as the norm in the majority of cases, unauthorized access to hostel rooms by non-hostel dwellers was rampant, sexual harassment of female students by men who were under the influence of alcohol was reported to be common and there was general lack of support for victims of sexual abuse in the hostels. In addition, there was a general sense of insecurity in the hostels where more than 50% of the participants were afraid of being sexually attacked, some female hostel residents engaged in sexual activities for monetary and material gain and there was a general practice of older men from the community having sexual relations with young female hostel dwellers. To mitigate these and other risks it is recommended that there be provision of more HIV/AIDS prevention services, enhanced security, non-toxic entertainment (e.g. participation in sport and social clubs) and the banning of the sale of alcohol in student residences and on tertiary institution campuses. These and other results are discussed in the article and ways of mitigating the risks are proposed.

  3. Interactome of E. piscicida and grouper liver proteins reveals strategies of bacterial infection and host immune response

    PubMed Central

    Li, Hui; Zhu, Qing-feng; Peng, Xuan-xian; Peng, Bo

    2017-01-01

    The occurrence of infectious diseases is related to heterogeneous protein interactions between a host and a microbe. Therefore, elucidating the host-pathogen interplay is essential. We previously revealed the protein interactome between Edwardsiella piscicida and fish gill cells, and the present study identified the protein interactome between E. piscicida and E. drummondhayi liver cells. E. drummondhayi liver cells and bacterial pull-down approaches were used to identify E. piscicida outer membrane proteins that bind to liver cells and fish liver cell proteins that interact with bacterial cells, respectively. Eight bacterial proteins and 11 fish proteins were characterized. Heterogeneous protein-protein interactions between these bacterial cells and fish liver cells were investigated through far-Western blotting and co-immunoprecipitation. A network was constructed based on 42 heterogeneous protein-protein interactions between seven bacterial proteins and 10 fish proteins. A comparison of the new interactome with the previously reported interactome showed that four bacterial proteins overlapped, whereas all of the identified fish proteins were new, suggesting a difference between bacterial tricks for evading host immunity and the host strategy for combating bacterial infection. Furthermore, these bacterial proteins were found to regulate the expression of host innate immune-related proteins. These findings indicate that the interactome contributes to bacterial infection and host immunity. PMID:28045121

  4. Cost-effectiveness analysis of recruitment strategies in a community-based intervention study of HIV-infected persons.

    PubMed

    Baigis, J; Francis, M E; Hoffman, M

    2003-10-01

    This paper describes and evaluates recruitment methods used to reach adults with HIV infection and to enroll eligible candidates in a randomized trial of aerobic exercise. Potential participants residing in the metropolitan Washington DC area were recruited from January 1994 to December 1996. The yield and associated cost of clinic centre site-visit (CSV) recruitment are compared to similar outcomes for community-based (CB) recruitment strategies, which consisted of presentations to local groups, mail/phone canvasses of caregivers, neighbourhood network promotion, public site postings and print media notices. Of 833 HIV infected adults ascertained during the recruitment phase as prospective study candidates, 66.7% were initially contacted during CSV recruitment. The remainder, 33.3% were CB recruits. The percentage of screened candidates who were subsequently enrolled in the study was 13.5% for CSV recruitment and 21% for CB recruitment. Ascertainment and screening costs combined were $158 per CB recruit compared to $232 per CSV recruit. Using multiple recruitment approaches we successfully achieved our enrollment goal of at least 100 volunteers from diverse populations by the end of the planned recruitment period.

  5. Optimal First-Line Treatment for Helicobacter pylori Infection: Recent Strategies

    PubMed Central

    2016-01-01

    A new treatment strategy is needed, as the efficacy of triple therapy containing clarithromycin—the current standard treatment for Helicobacter pylori infection—is declining. Increasing antibiotic resistance of H. pylori is the most significant factor contributing to eradication failure. Thus, selecting the most appropriate regimen depending on resistance is optimal, but identifying resistance to specific antibiotics is clinically challenging. In a region suspected to have high clarithromycin resistance, bismuth quadruple therapy and so-called nonbismuth quadruple therapies (sequential, concomitant, and sequential-concomitant hybrid) are some first-line regimen options. However, more research is needed regarding appropriate second-line treatments after first-line treatment failure. Tailored therapy, which is based on antibiotic sensitivity testing, would be optimal but has several limitations for clinical use, and an alternative technique is required. A novel potassium-competitive acid blocker-based eradication regimen could be a valuable eradication option in the near future. PMID:28070184

  6. Strategies to overcome the action of aminoglycoside-modifying enzymes for treating resistant bacterial infections

    PubMed Central

    Labby, Kristin J; Garneau-Tsodikova, Sylvie

    2013-01-01

    Shortly after the discovery of the first antibiotics, bacterial resistance began to emerge. Many mechanisms give rise to resistance; the most prevalent mechanism of resistance to the aminoglycoside (AG) family of antibiotics is the action of aminoglycoside-modifying enzymes (AMEs). Since the identification of these modifying enzymes, many efforts have been put forth to prevent their damaging alterations of AGs. These diverse strategies are discussed within this review, including: creating new AGs that are unaffected by AMEs; developing inhibitors of AMEs to be co-delivered with AGs; or regulating AME expression. Modern high-throughput methods as well as drug combinations and repurposing are highlighted as recent drug-discovery efforts towards fighting the increasing antibiotic resistance crisis. PMID:23859208

  7. Passive immune neutralization strategies for prevention and control of influenza A infections.

    PubMed

    Ye, Jianqiang; Shao, Hongxia; Perez, Daniel R

    2012-02-01

    Although vaccination significantly reduces influenza severity, seasonal human influenza epidemics still cause more than 250,000 deaths annually. Vaccine efficacy is limited in high-risk populations such as infants, the elderly and immunosuppressed individuals. In the event of an influenza pandemic (such as the 2009 H1N1 pandemic), a significant delay in vaccine availability represents a significant public health concern, particularly in high-risk groups. The increasing emergence of strains resistant to the two major anti-influenza drugs, adamantanes and neuraminidase inhibitors, and the continuous circulation of avian influenza viruses with pandemic potential in poultry, strongly calls for alternative prophylactic and treatment options. In this review, we focus on passive virus neutralization strategies for the prevention and control of influenza type A viruses.

  8. [Strategy for the introduction of medications employed in delivering medical care to patients with sexually transmitted infections into the retail market].

    PubMed

    Martynenko, A V

    2002-01-01

    Tha article is devoted to the development of strategy for entering the retail market of those medications intended for medical care delivery to patients with infections caught by sexual intercourse or genital contact. The use of the proposed strategy permits the optimization of the structure of necessary expenditures on material resources and enables one to successfully compete in the market of medications winning one's share in the market from competitors.

  9. Gastrointestinal nematode infection and performance of weaned stocker calves in response to anthelmintic control strategies.

    PubMed

    Walker, R S; Miller, J E; Monlezun, C J; LaMay, D; Navarre, C; Ensley, D

    2013-10-18

    Gastrointestinal nematode (GIN) parasite control recommendations are in a state of flux because of the increase in anthelmintic resistant cattle parasites, such as Cooperia spp. In addition, Cooperia spp. infection is typically high in warm-season grass pastures and can affect growth performance of grazing stocker calves in the Gulf Coast Region. This study evaluated the effects of moxidectin pour-on, oxfendazole oral suspension, or a combination of the two given at separate times on infection and performance of weaned beef calves grazing summer forages. Steers (n=42) and heifers (n=31) were stratified by sex, d-11 fecal egg count (FEC), and d-1 shrunk body weight (BW) to one of 10 pastures with four anthelmintic treatments and one control. Treatments included: (1) oxfendazole given on d 0 and moxidectin on d 73 (O+M), (2) moxidectin given on d 0 and oxfendazole on d 73 (M+O), (3) moxidectin given on d 0 (M), (4) oxfendazole given on d 0 (O) and (5) no anthelmintic given (CON). Calves grazed for d-110 beginning May 27th. Response variables were FEC (collected on d-11, 14, 31, 45, 59, 73, 87 and 108), coprocultures (evaluated for d 87 and 108), final shrunk BW, shrunk BW gain, average daily gain (ADG), and full BW gain (collected on d 31, 59, 73, 87, and 108). Calves treated with either oxfendazole (O+M and O) or moxidectin (M+O and M) on d 0 had significantly lower (P<0.001) FEC than the CON calves on d 14, 31 and 45. However, the M+O treated calves had significantly higher (P<0.001) FEC than both oxfendazole treated groups. In addition, calves treated with a second dewormer on d 73 (O+M and M+O) had significantly lower (P<0.001) FEC by d 87 than the CON or M treated calves. Shrunk BW gain and ADG were significantly greater (P=0.005) for the O+M compared to the M treated and CON calves, but comparable with the M+O and O treated calves, respectively. Coprocultures sampled on d 87 and 108 for calves not receiving a second dewormer were predominantly Cooperia spp. and

  10. Parasitism performance and fitness of Cotesia vestalis (Hymenoptera: Braconidae) infected with Nosema sp. (Microsporidia: Nosematidae): implications in integrated pest management strategy.

    PubMed

    Kermani, Nadia; Abu Hassan, Zainal-Abidin; Suhaimi, Amalina; Abuzid, Ismail; Ismail, Noor Farehan; Attia, Mansour; Ghani, Idris Abd

    2014-01-01

    The diamondback moth (DBM) Plutella xylostella (L.) has traditionally been managed using synthetic insecticides. However, the increasing resistance of DBM to insecticides offers an impetus to practice integrated pest management (IPM) strategies by exploiting its natural enemies such as pathogens, parasitoids, and predators. Nevertheless, the interactions between pathogens and parasitoids and/or predators might affect the effectiveness of the parasitoids in regulating the host population. Thus, the parasitism rate of Nosema-infected DBM by Cotesia vestalis (Haliday) (Hym., Braconidae) can be negatively influenced by such interactions. In this study, we investigated the effects of Nosema infection in DBM on the parasitism performance of C. vestalis. The results of no-choice test showed that C. vestalis had a higher parasitism rate on non-infected host larvae than on Nosema-treated host larvae. The C. vestalis individuals that emerged from Nosema-infected DBM (F1) and their progeny (F2) had smaller pupae, a decreased rate of emergence, lowered fecundity, and a prolonged development period compared to those of the control group. DBM infection by Nosema sp. also negatively affected the morphometrics of C. vestalis. The eggs of female C. vestalis that developed in Nosema-infected DBM were larger than those of females that developed in non-infected DBM. These detrimental effects on the F1 and F2 generations of C. vestalis might severely impact the effectiveness of combining pathogens and parasitoids as parts of an IPM strategy for DBM control.

  11. Parasitism Performance and Fitness of Cotesia vestalis (Hymenoptera: Braconidae) Infected with Nosema sp. (Microsporidia: Nosematidae): Implications in Integrated Pest Management Strategy

    PubMed Central

    Kermani, Nadia; Abu Hassan, Zainal-Abidin; Suhaimi, Amalina; Abuzid, Ismail; Ismail, Noor Farehan; Attia, Mansour; Ghani, Idris Abd

    2014-01-01

    The diamondback moth (DBM) Plutella xylostella (L.) has traditionally been managed using synthetic insecticides. However, the increasing resistance of DBM to insecticides offers an impetus to practice integrated pest management (IPM) strategies by exploiting its natural enemies such as pathogens, parasitoids, and predators. Nevertheless, the interactions between pathogens and parasitoids and/or predators might affect the effectiveness of the parasitoids in regulating the host population. Thus, the parasitism rate of Nosema-infected DBM by Cotesia vestalis (Haliday) (Hym., Braconidae) can be negatively influenced by such interactions. In this study, we investigated the effects of Nosema infection in DBM on the parasitism performance of C. vestalis. The results of no-choice test showed that C. vestalis had a higher parasitism rate on non-infected host larvae than on Nosema-treated host larvae. The C. vestalis individuals that emerged from Nosema-infected DBM (F1) and their progeny (F2) had smaller pupae, a decreased rate of emergence, lowered fecundity, and a prolonged development period compared to those of the control group. DBM infection by Nosema sp. also negatively affected the morphometrics of C. vestalis. The eggs of female C. vestalis that developed in Nosema-infected DBM were larger than those of females that developed in non-infected DBM. These detrimental effects on the F1 and F2 generations of C. vestalis might severely impact the effectiveness of combining pathogens and parasitoids as parts of an IPM strategy for DBM control. PMID:24968125

  12. Use of a capture-based pathogen transcript enrichment strategy for RNA-Seq analysis of the Francisella tularensis LVS transcriptome during infection of murine macrophages.

    PubMed

    Bent, Zachary W; Brazel, David M; Tran-Gyamfi, Mary B; Hamblin, Rachelle Y; VanderNoot, Victoria A; Branda, Steven S

    2013-01-01

    Francisella tularensis is a zoonotic intracellular pathogen that is capable of causing potentially fatal human infections. Like all successful bacterial pathogens, F. tularensis rapidly responds to changes in its environment during infection of host cells, and upon encountering different microenvironments within those cells. This ability to appropriately respond to the challenges of infection requires rapid and global shifts in gene expression patterns. In this study, we use a novel pathogen transcript enrichment strategy and whole transcriptome sequencing (RNA-Seq) to perform a detailed characterization of the rapid and global shifts in F. tularensis LVS gene expression during infection of murine macrophages. We performed differential gene expression analysis on all bacterial genes at two key stages of infection: phagosomal escape, and cytosolic replication. By comparing the F. tularensis transcriptome at these two stages of infection to that of the bacteria grown in culture, we were able to identify sets of genes that are differentially expressed over the course of infection. This analysis revealed the temporally dynamic expression of a number of known and putative transcriptional regulators and virulence factors, providing insight into their role during infection. In addition, we identified several F. tularensis genes that are significantly up-regulated during infection but had not been previously identified as virulence factors. These unknown genes may make attractive therapeutic or vaccine targets.

  13. Application of polymer nanocomposites in the nanomedicine landscape: envisaging strategies to combat implant associated infections.

    PubMed

    Dwivedi, Poushpi; Narvi, Shahid S; Tewari, Ravi P

    2013-12-16

    This review article presents an overview of the potential biomedical application of polymer nanocomposites arising from different chemistries, compositions, and constructions. The interaction between the chosen matrix and the filler is of critical importance. The existing polymer used in the biomedical arena includes aliphatic polyesters such as polylactide (PLA), poly(ε-caprolactone) (PCL), poly(p-dioxanone) (PPDO), poly(butylenes succinate) (PBS), poly(hydroxyalkanoate)s, and natural biopolymers such as starch, cellulose, chitin, chitosan, lignin, and proteins. The nanosized fillers utilized to fabricate the nanocomposites are inorganic, organic, and metal particles such as clays, magnetites, hydroxyapatite, nanotubes chitin whiskers, lignin, cellulose, Au, Ag, Cu, etc. These nanomaterials are taking root in a variety of diverse healthcare applications in the sector of nanomedicine including the domain of medical implants and devices. Despite sterilization and aseptic procedures the use of these biomedical devices and prosthesis to improve the patient's 'quality of life' is facing a major impediment because of bacterial colonization causing nosocomial infection, together with the multi-drug-resistant 'super-bugs' posing a serious threat to its utility. This paper discusses the current efforts and key research challenges in the development of self-sterilizing nanocomposite biomaterials for potential application in this area.

  14. Treatment strategies for HIV-infected patients with tuberculosis: ongoing and planned clinical trials.

    PubMed

    Blanc, Francois-Xavier; Havlir, Diane V; Onyebujoh, Philip C; Thim, Sok; Goldfeld, Anne E; Delfraissy, Jean-Francois

    2007-08-15

    Currently, there are limited data to guide the management of highly active antiretroviral therapy (HAART) for human immunodeficiency virus type 1 (HIV-1)-infected patients with active tuberculosis (TB), the leading cause of death among individuals with acquired immunodeficiency syndrome (AIDS) in resource-limited areas. Four trials to take place in Southeast Asian, African, and South American countries will address the unresolved question of the optimal timing for initiation of HAART in patients with AIDS and TB: (1) Cambodian Early versus Late Introduction of Antiretrovirals (CAMELIA [ANRS 1295/NIH-CIPRA KH001]), (2) Adult AIDS Clinical Trials Group A5221, (3) START, and (4) a trial sponsored by the World Health Organization/Special Programme for Research and Training in Tropical Diseases. Two other clinical questions regarding patients with TB and HIV-1 coinfection are also undergoing evaluation: (1) the benefits of short-term HAART when CD4 cell counts are >350 cells/mm(3) (PART [NIH 1 R01 AI051219-01A2]) and (2) the efficacy of a once-daily HAART regimen in treatment-naive patients (BKVIR [ANRS 129]). Here, we present an overview of these ongoing or planned clinical studies, which are supported by international agencies.

  15. The “Cheshire Cat” escape strategy of the coccolithophore Emiliania huxleyi in response to viral infection

    PubMed Central

    Frada, Miguel; Probert, Ian; Allen, Michael J.; Wilson, William H.; de Vargas, Colomban

    2008-01-01

    The coccolithophore Emiliania huxleyi is one of the most successful eukaryotes in modern oceans. The two phases in its haplodiploid life cycle exhibit radically different phenotypes. The diploid calcified phase forms extensive blooms, which profoundly impact global biogeochemical equilibria. By contrast, the ecological role of the noncalcified haploid phase has been completely overlooked. Giant phycodnaviruses (Emiliania huxleyi viruses, EhVs) have been shown to infect and lyse diploid-phase cells and to be heavily implicated in the regulation of populations and the termination of blooms. Here, we demonstrate that the haploid phase of E. huxleyi is unrecognizable and therefore resistant to EhVs that kill the diploid phase. We further show that exposure of diploid E. huxleyi to EhVs induces transition to the haploid phase. Thus we have clearly demonstrated a drastic difference in viral susceptibility between life cycle stages with different ploidy levels in a unicellular eukaryote. Resistance of the haploid phase of E. huxleyi provides an escape mechanism that involves separation of meiosis from sexual fusion in time, thus ensuring that genes of dominant diploid clones are passed on to the next generation in a virus-free environment. These “Cheshire Cat” ecological dynamics release host evolution from pathogen pressure and thus can be seen as an opposite force to a classic “Red Queen” coevolutionary arms race. In E. huxleyi, this phenomenon can account for the fact that the selective balance is tilted toward the boom-and-bust scenario of optimization of both growth rates of calcifying E. huxleyi cells and infectivity of EhVs. PMID:18824682

  16. Transfusion transmitted infections in thalassaemics: need for reappraisal of blood screening strategy in India.

    PubMed

    Shyamala, V

    2014-04-01

    The aim of the study was to assess the blood safety in India through prevalence in thalassaemic population. Safety of the blood supply is a subject of great concern for all recipients. This review attempts to assess the relevance and format of tests for viruses in the context of transfusion transmitted infection (TTI) prevalence in India. Serological marker testing for human immunodeficiency virus-1/2 (HIV-1/2), hepatitis C virus (HCV) and hepatitis B virus (HBV) is mandatory in India. Numerous TTI incidents in the repeat recipients supported by results from nucleic acid technology (NAT) testing indicate the deficiencies in blood safety. The β-thalassaemic population (3-17%) in India has been used to reflect on blood safety. The prevalence of HIV-1/2, HCV and HBV in the Indian donor population, the limitations in accessing safe donors, quality of serological tests and the impact on repeat recipients is evaluated. The reports point to prevalence of ˜2% of viral diseases in the blood donor population, and the insufficiency of serology testing resulting in up to 45% TTIs in thalassaemics. The revelation by individual donation (ID) NAT testing, of 1 per 310 units being serology negative-NAT reactive is alarming. Extrapolating the serology negative NAT reactive yields, for an annual blood supply of 7.9 million units, 23,700 units or nearly 100,000 blood components are likely to be infectious. Though the cost for ID-NAT testing is considered unaffordable for a medium development country such as India, the enormity of TTIs will place an unmanageable cost burden on the society.

  17. Proteomics Analysis Reveals a Potential Antibiotic Cocktail Therapy Strategy for Aeromonas hydrophila Infection in Biofilm.

    PubMed

    Li, Wanxin; Yao, Zujie; Sun, Lina; Hu, Wenjie; Cao, Jijuan; Lin, Wenxiong; Lin, Xiangmin

    2016-06-03

    Antibiotic fitness and acquired resistance are the two critical factors when bacteria respond to antibiotics, and the correlations and mechanisms between these two factors remain largely unknown. In this study, a TMT-labeling-based quantitative proteomics method was used to compare the differential expression of proteins between the fitness and acquired resistance to chlortetracycline in Aeromonas hydrophila biofilm. Bioinformatics analysis showed that translation-related ribosomal proteins, such as 30s ribosome subunits, increased in both factors; fatty acid biosynthesis related proteins, such as FabB, FabD, FabG, AccA, and AccD, increased in biofilm fitness, and some pathways (including propanoate-metabolism-related protein, such as PrpB, AtoB, PflB, AcsA, PrpD, and GabT) displayed decreased abundance in acquired resistance biofilm. The varieties of selected proteins involved in fatty acid biosynthesis and propanoate metabolism were further validated by q-PCR assay or Western blotting. Furthermore, the antibiotic-resistance-function assays showed that fatty-acid biosynthesis should be a protective antibiotics-resistance mechanism and a cocktail of chlortetracycline and triclosan, a fatty-acid-biosynthesis inhibitor, exhibited more efficient antimicrobial capability than did each antibiotic individually on biofilm, specifically on chlortetracycline-sensitive biofilm. We therefore demonstrate that the up-regulation of fatty acid biosynthesis may play an important role in antibiotic resistance and suggest that a cocktail of chlortetracycline and triclosan may be a potential cocktail therapy for pathogenic infections in biofilm.

  18. Late Diagnosis Due to Missed Opportunities and Inadequate Screening Strategies in HIV Infected Mexican Women.

    PubMed

    Martin-Onraët, Alexandra; Volkow-Fernández, Patricia; Alvarez-Wyssmann, Victoria; González-Rodríguez, Andrea; Casillas-Rodríguez, Jesús; Rivera-Abarca, Lesvia; Torres-Escobar, Indiana; Sierra-Madero, Juan

    2017-02-01

    Late diagnosis of HIV remains a public health issue in Mexico. Most national programs target high-risk groups, not including women. More data on factors associated with late diagnosis and access to care in women are needed. In 2012-2013, Mexican women recently diagnosed with HIV were interviewed. Socio-cultural background, household-dynamics and clinical data were collected. Of 301 women, 49 % had <200 CD4 cells/mm(3), 8 % were illiterate, 31 % had only primary school. Physical/sexual violence was reported by 47/30 %; 75 % acquired HIV from their stable partners. Prenatal HIV screening was not offered in 61 %; 40 % attended consultation for HIV-related symptoms without being tested for HIV. Seeking medical care ≥3 times before diagnosis was associated with baseline CD4 <200 cells/mm(3) (adjusted OR 3.74, 95 % CI 1.88-7.45, p < 0.001). There were missed opportunities during prenatal screening and when symptomatic women seeked medical care. Primary care needs to be improved and new strategies implemented for early diagnosis in women.

  19. Update on epidemiology of and preventive strategies for invasive fungal infections in cancer patients.

    PubMed

    Perfect, John R; Hachem, Ray; Wingard, John R

    2014-11-15

    Changes in antineoplastic treatments and transplant practices are driving shifts in the epidemiology of invasive fungal diseases (IFDs). Patients with acute myelogenous leukemia (AML) and those undergoing bone marrow transplant (BMT) are at greatest risk for contracting IFDs. Unfortunately, there are few large population studies that can be used to track trends and help us to better understand why certain individuals within recognized high-risk groups are at greater risks than others for contracting IFDs. The growing use of antifungals in prophylaxis and treatment influences which species will cause an IFD as well as the resistance patterns of these fungi. On the one hand, antifungal prophylaxis has mitigated, but not eliminated, the threat of candidiasis. Furthermore, prophylaxis trials have shown trends of reduced aspergillosis in BMT patients; however, no survival benefits were seen, and 1 trial indicated a lower rate of aspergillosis and survival benefits in patients with AML. Future prophylaxis trials should reduce the heterogeneity of risk in study participants in order to better assess benefit; these trials should also incorporate fungal biomarkers into their design. The threat of emerging fungal resistance in prophylaxis strategies is real and must be monitored.

  20. A cost-effectiveness modelling study of strategies to reduce risk of infection following primary hip replacement based on a systematic review.

    PubMed Central

    Graves, Nicholas; Wloch, Catherine; Wilson, Jennie; Barnett, Adrian; Sutton, Alex; Cooper, Nicola; Merollini, Katharina; McCreanor, Victoria; Cheng, Qinglu; Burn, Edward; Lamagni, Theresa; Charlett, Andre

    2016-01-01

    BACKGROUND A deep infection of the surgical site is reported in 0.7% of all cases of total hip arthroplasty (THA). This often leads to revision surgery that is invasive, painful and costly. A range of strategies is employed in NHS hospitals to reduce risk, yet no economic analysis has been undertaken to compare the value for money of competing prevention strategies. OBJECTIVES To compare the costs and health benefits of strategies that reduce the risk of deep infection following THA in NHS hospitals. To make recommendations to decision-makers about the cost-effectiveness of the alternatives. DESIGN The study comprised a systematic review and cost-effectiveness decision analysis. SETTING 77,321 patients who had a primary hip arthroplasty in NHS hospitals in 2012. INTERVENTIONS Nine different treatment strategies including antibiotic prophylaxis, antibiotic-impregnated cement and ventilation systems used in the operating theatre. MAIN OUTCOME MEASURES Change in the number of deep infections, change in the total costs and change in the total health benefits in quality-adjusted life-years (QALYs). DATA SOURCES Literature searches using MEDLINE, EMBASE, Cumulative Index to Nursing and Allied Health Literature and the Cochrane Central Register of Controlled Trials were undertaken to cover the period 1966-2012 to identify infection prevention strategies. Relevant journals, conference proceedings and bibliographies of retrieved papers were hand-searched. Orthopaedic surgeons and infection prevention experts were also consulted. REVIEW METHODS English-language papers only. The selection of evidence was by two independent reviewers. Studies were included if they were interventions that reported THA-related deep surgical site infection (SSI) as an outcome. Mixed-treatment comparisons were made to produce estimates of the relative effects of competing infection control strategies. RESULTS Twelve studies, six randomised controlled trials and six observational studies, involving

  1. The sun, moon, wind, and biological imperative-shaping contrasting wintertime migration and foraging strategies of adult male and female northern fur seals (Callorhinus ursinus).

    PubMed

    Sterling, Jeremy T; Springer, Alan M; Iverson, Sara J; Johnson, Shawn P; Pelland, Noel A; Johnson, Devin S; Lea, Mary-Anne; Bond, Nicholas A

    2014-01-01

    Adult male and female northern fur seals (Callorhinus ursinus) are sexually segregated in different regions of the North Pacific Ocean and Bering Sea during their winter migration. Explanations for this involve interplay between physiology, predator-prey dynamics, and ecosystem characteristics, however possible mechanisms lack empirical support. To investigate factors influencing the winter ecology of both sexes, we deployed five satellite-linked conductivity, temperature, and depth data loggers on adult males, and six satellite-linked depth data loggers and four satellite transmitters on adult females from St. Paul Island (Bering Sea, Alaska, USA) in October 2009. Males and females migrated to different regions of the North Pacific Ocean: males wintered in the Bering Sea and northern North Pacific Ocean, while females migrated to the Gulf of Alaska and California Current. Horizontal and vertical movement behaviors of both sexes were influenced by wind speed, season, light (sun and moon), and the ecosystem they occupied, although the expression of the behaviors differed between sexes. Male dive depths were aligned with the depth of the mixed layer during daylight periods and we suspect this was the case for females upon their arrival to the California Current. We suggest that females, because of their smaller size and physiological limitations, must avoid severe winters typical of the northern North Pacific Ocean and Bering Sea and migrate long distances to areas of more benign environmental conditions and where prey is shallower and more accessible. In contrast, males can better tolerate often extreme winter ocean conditions and exploit prey at depth because of their greater size and physiological capabilities. We believe these contrasting winter behaviors 1) are a consequence of evolutionary selection for large size in males, important to the acquisition and defense of territories against rivals during the breeding season, and 2) ease environmental

  2. The Sun, Moon, Wind, and Biological Imperative–Shaping Contrasting Wintertime Migration and Foraging Strategies of Adult Male and Female Northern Fur Seals (Callorhinus ursinus)

    PubMed Central

    Sterling, Jeremy T; Springer, Alan M.; Iverson, Sara J.; Johnson, Shawn P.; Pelland, Noel A.; Johnson, Devin S.; Lea, Mary-Anne; Bond, Nicholas A.

    2014-01-01

    Adult male and female northern fur seals (Callorhinus ursinus) are sexually segregated in different regions of the North Pacific Ocean and Bering Sea during their winter migration. Explanations for this involve interplay between physiology, predator-prey dynamics, and ecosystem characteristics, however possible mechanisms lack empirical support. To investigate factors influencing the winter ecology of both sexes, we deployed five satellite-linked conductivity, temperature, and depth data loggers on adult males, and six satellite-linked depth data loggers and four satellite transmitters on adult females from St. Paul Island (Bering Sea, Alaska, USA) in October 2009. Males and females migrated to different regions of the North Pacific Ocean: males wintered in the Bering Sea and northern North Pacific Ocean, while females migrated to the Gulf of Alaska and California Current. Horizontal and vertical movement behaviors of both sexes were influenced by wind speed, season, light (sun and moon), and the ecosystem they occupied, although the expression of the behaviors differed between sexes. Male dive depths were aligned with the depth of the mixed layer during daylight periods and we suspect this was the case for females upon their arrival to the California Current. We suggest that females, because of their smaller size and physiological limitations, must avoid severe winters typical of the northern North Pacific Ocean and Bering Sea and migrate long distances to areas of more benign environmental conditions and where prey is shallower and more accessible. In contrast, males can better tolerate often extreme winter ocean conditions and exploit prey at depth because of their greater size and physiological capabilities. We believe these contrasting winter behaviors 1) are a consequence of evolutionary selection for large size in males, important to the acquisition and defense of territories against rivals during the breeding season, and 2) ease environmental

  3. In Situ Bioorthogonal Metabolic Labeling for Fluorescence Imaging of Virus Infection In Vivo.

    PubMed

    Pan, Hong; Li, Wen-Jun; Yao, Xiang-Jie; Wu, Ya-Yun; Liu, Lan-Lan; He, Hua-Mei; Zhang, Ren-Li; Ma, Yi-Fan; Cai, Lin-Tao

    2017-02-20

    Optical fluorescence imaging is an important strategy to explore the mechanism of virus-host interaction. However, current fluorescent tag labeling strategies often dampen viral infectivity. The present study explores an in situ fluorescent labeling strategy in order to preserve viral infectivity and precisely monitor viral infection in vivo. In contrast to pre-labeling strategy, mice are first intranasally infected with azide-modified H5N1 pseudotype virus (N3 -H5N1p), followed by injection of dibenzocyclooctyl (DBCO)-functionalized fluorescence 6 h later. The results show that DBCO dye directly conjugated to N3 -H5N1p in lung tissues through in vivo bioorthogonal chemistry with high specificity and efficacy. More remarkably, in situ labeling rather than conventional prelabeling strategy effectively preserves viral infectivity and immunogenicity both in vitro and in vivo. Hence, in situ bioorthogonal viral labeling is a promising and reliable strategy for imaging and tracking viral infection in vivo.

  4. Addressing current medical needs in invasive fungal infection prevention and treatment with new antifungal agents, strategies and formulations.

    PubMed

    Pitman, Stuart K; Drew, Richard H; Perfect, John R

    2011-09-01

    Introduction: Morbidity and mortality associated with invasive fungal infections (IFIs) remains unacceptably high. Such diseases represent a substantial burden to the healthcare system. New options are needed to address antifungal resistance in existing and emerging pathogens and improve treatment outcomes while minimizing drug-related toxicities and interactions. Awareness of new and potential future options is of great value for those healthcare professionals who care for patients with IFIs. Areas covered: A search of PubMed, infectious diseases conference abstracts and reference lists from relevant publications was conducted and relevant information abstracted. This review describes the limitations of existing systemic antifungal therapies (e.g., resistance, drug-drug interactions, drug-related toxicities) and summarizes data regarding several emerging antifungal compounds including (but not limited to) new triazoles (e.g. isavuconazole, ravuconazole), echinocandins (e.g., aminocandin) and nikkomycin Z. Agents in clinical trials such as (but not limited to) new triazoles (e.g., isavuconazole, ravuconazole), echinocandins (e.g., aminocandin) and nikkomycin are included. New formulations of existing drugs including reformulations of miconazole, posaconazole and amphotericin B are also reviewed. Finally, new or novel administration strategies for existing drugs such as combination antifungal therapy, antifungal dose escalation, adjunctive use of iron chelators and preemptive therapy are discussed. Expert opinion: All present antifungal agents have some deficiencies in antifungal spectra, toxicity, pharmacokinetics and/or drug-drug interactions, making them less than ideal for some fungal infections. Therefore, there remains an urgent need to find safe, effective, rapidly fungicidal, broad-spectrum antifungal agents with excellent pharmacodynamics to effectively eliminate the fungus from the body with short antifungal courses.

  5. Infection prevention and control strategies in the era of limited resources and quality improvement: a perspective paper.

    PubMed

    Vandijck, Dominique; Cleemput, Irina; Hellings, Johan; Vogelaers, Dirk

    2013-11-01

    This paper aims to describe, using an evidence-based approach, the importance of and the resources necessary for implementing effective infection prevention and control (IPC) programmes. The intrinsic and explicit values of such strategies are presented from a clinical, health-economic and patient safety perspective. Policy makers and hospital managers are committed to providing comprehensive, accessible, and affordable healthcare of high quality. Changes in the healthcare system over time accompanied with variations in demographics and case-mix have considerably affected the availability, quality and ultimately the safety of healthcare. The main goal of an IPC programme is to prevent and control healthcare-associated infections (HAI). Many patient-, healthcare provider-, and organizational factors are associated with an increased risk for acquiring HAIs and may impact both the quality and outcome of patient care. Evidence has been published in support of having an effective IPC programme. It has been estimated that about one-third of HAIs could be prevented if key elements of the evidence-based recommendations for IPC are adequately introduced and followed. However, several healthcare agencies from over the world have reported deficits in the essential resources and components of current IPC programmes. To meet its main goal, staffing, training, and infrastructure requirements are needed. Nevertheless, and given the economic crisis, policy makers and hospital managers may be tempted to not increase or even to reduce the budget as it consumes resources and does not generate sufficient visible revenue. IPC is a critical issue in patient safety, as HAIs are by far the most common complication affecting admitted patients. The significant clinical and health-economic burden HAIs place on the healthcare system speak to the importance of getting introduced effective IPC programmes.

  6. Selective testing strategies for diagnosing group A streptococcal infection in children with pharyngitis: a systematic review and prospective multicentre external validation study

    PubMed Central

    Cohen, Jérémie F.; Cohen, Robert; Levy, Corinne; Thollot, Franck; Benani, Mohamed; Bidet, Philippe; Chalumeau, Martin

    2015-01-01

    Background: Several clinical prediction rules for diagnosing group A streptococcal infection in children with pharyngitis are available. We aimed to compare the diagnostic accuracy of rules-based selective testing strategies in a prospective cohort of children with pharyngitis. Methods: We identified clinical prediction rules through a systematic search of MEDLINE and Embase (1975–2014), which we then validated in a prospective cohort involving French children who presented with pharyngitis during a 1-year period (2010–2011). We diagnosed infection with group A streptococcus using two throat swabs: one obtained for a rapid antigen detection test (StreptAtest, Dectrapharm) and one obtained for culture (reference standard). We validated rules-based selective testing strategies as follows: low risk of group A streptococcal infection, no further testing or antibiotic therapy needed; intermediate risk of infection, rapid antigen detection for all patients and antibiotic therapy for those with a positive test result; and high risk of infection, empiric antibiotic treatment. Results: We identified 8 clinical prediction rules, 6 of which could be prospectively validated. Sensitivity and specificity of rules-based selective testing strategies ranged from 66% (95% confidence interval [CI] 61–72) to 94% (95% CI 92–97) and from 40% (95% CI 35–45) to 88% (95% CI 85–91), respectively. Use of rapid antigen detection testing following the clinical prediction rule ranged from 24% (95% CI 21–27) to 86% (95% CI 84–89). None of the rules-based selective testing strategies achieved our diagnostic accuracy target (sensitivity and specificity > 85%). Interpretation: Rules-based selective testing strategies did not show sufficient diagnostic accuracy in this study population. The relevance of clinical prediction rules for determining which children with pharyngitis should undergo a rapid antigen detection test remains questionable. PMID:25487666

  7. Novel therapeutic investigational strategies to treat severe and disseminated HSV infections suggested by a deeper understanding of in vitro virus entry processes.

    PubMed

    Clementi, Nicola; Criscuolo, Elena; Cappelletti, Francesca; Burioni, Roberto; Clementi, Massimo; Mancini, Nicasio

    2016-04-01

    The global burden of herpes simplex virus (HSV) legitimates the critical need to develop new prevention strategies, such as drugs and vaccines that are able to fight either primary HSV infections or reactivations. Moreover, the ever-growing number of patients receiving transplants increases the number of severe HSV infections that are unresponsive to current therapies. Finally, the high global incidence of genital HSV-2 infection increases the risk of perinatal transmission to newborns, in which disseminated infection or central nervous system (CNS) involvement is frequent, with associated high morbidity and mortality rates. There are several key features shared by novel anti-HSV drugs, from currently available optimized drugs to small molecules able to interfere with various virus replication steps. However, several virological aspects of the disease and associated clinical needs highlight why an ideal anti-HSV drug has yet to be developed.

  8. The role of infections in the emergence of non-communicable diseases (NCDs): Compelling needs for novel strategies in the developing world.

    PubMed

    Ogoina, Dimie; Onyemelukwe, Geofrey C

    2009-01-01

    The emergence of non-communicable diseases (NCDs) follows multiple aetiological pathways requiring recognition for effective control and prevention. Infections are proving to be conventional, emerging and re-emerging aetiological factors for many NCDs. This review explores the possible mechanisms by which infections induce NCDs citing examples of studies in Africa and elsewhere where NCDs and infections are proposed or confirmed to be causally linked and also discusses the implications and challenges of these observations for science and medicine. The need to re-evaluate and expand early community and individual preventive and control strategies that will lead to reduction and even elimination of NCDs especially in Africa and other developing countries where infections are prevalent is highlighted.

  9. Five years investigation of female and male genotypes in Périgord black truffle (Tuber melanosporum Vittad.) revealed contrasted reproduction strategies.

    PubMed

    De la Varga, Herminia; Le Tacon, François; Lagoguet, Mélanie; Todesco, Flora; Varga, Torda; Miquel, Igor; Barry-Etienne, Dominique; Robin, Christophe; Halkett, Fabien; Martin, Francis; Murat, Claude

    2017-03-29

    The Périgord black truffle (Tuber melanosporum Vittad.) is a heterothallic ascomycete that establishes ectomycorrhizal symbiosis with trees and shrubs. Small-scale genetic structures of female genotypes in truffle orchards are known, but it has not yet been studied in male genotypes. In this study, our aim was to characterize the small-scale genetic structure of both male and female genotypes over five years in an orchard to better understand the T. melanosporum sexual reproduction strategy, male genotype dynamics, and origins. Two-hundred forty-one ascocarps, 475 ectomycorrhizas, and 20 soil cores were harvested and genotyped using microsatellites and mating type genes. Isolation by distance analysis revealed pronounced small-scale genetic structures for both female and male genotypes. The genotypic diversity was higher for male than female genotypes with numerous small size genotypes suggesting an important turnover due to ascospore recruitment. Larger and perennial female and male genotypes were also detected. Only three genotypes (1.5%) were found as both female and male genotypes (hermaphrodites) while most were detected only as female or male genotype (dioecy). Our results suggest that germinating ascospores act as male genotypes, but we also proposed that soil mycelium could be a reservoir of male genotypes. This article is protected by copyright. All rights reserved.

  10. Genetic control of interactions among individuals: contrasting outcomes of indirect genetic effects arising from neighbour disease infection and competition in a forest tree.

    PubMed

    Costa e Silva, João; Potts, Brad M; Bijma, Piter; Kerr, Richard J; Pilbeam, David J

    2013-01-01

    Indirect genetic effects (IGEs) are heritable effects of individuals on trait values of their conspecifics. IGEs may substantially affect response to selection, but empirical studies on IGEs are sparse and their magnitude and correlation with direct genetic effects are largely unknown in plants. Here we used linear mixed models to estimate genetic (co)variances attributable to direct and indirect effects for growth and foliar disease damage in a large pedigreed population of Eucalyptus globulus. We found significant IGEs for growth and disease damage, which increased with age for growth. The correlation between direct and indirect genetic effects was highly negative for growth, but highly positive for disease damage, consistent with neighbour competition and infection, respectively. IGEs increased heritable variation by 71% for disease damage, but reduced heritable variation by 85% for growth, leaving nonsignificant heritable variation for later age growth. Thus, IGEs are likely to prevent response to selection in growth, despite a considerable ordinary heritability. IGEs change our perspective on the genetic architecture and potential response to selection. Depending on the correlation between direct and indirect genetic effects, IGEs may enhance or diminish the response to natural or artificial selection compared with that predicted from ordinary heritability.

  11. The staying safe intervention: training people who inject drugs in strategies to avoid injection-related HCV and HIV infection.

    PubMed

    Mateu-Gelabert, Pedro; Gwadz, Marya Viorst; Guarino, Honoria; Sandoval, Milagros; Cleland, Charles M; Jordan, Ashly; Hagan, Holly; Lune, Howard; Friedman, Samuel R

    2014-04-01

    This pilot study explores the feasibility and preliminary efficacy of the Staying Safe Intervention, an innovative, strengths-based program to facilitate prevention of infection with the human immunodeficiency virus and with the hepatitis C virus among people who inject drugs (PWID). The authors explored changes in the intervention's two primary endpoints: (a) frequency and amount of drug intake, and (b) frequency of risky injection practices. We also explored changes in hypothesized mediators of intervention efficacy: planning skills, motivation/self-efficacy to inject safely, skills to avoid PWID-associated stigma, social support, drug-related withdrawal symptoms, and injection network size and risk norms. A 1-week, five-session intervention (10 hours total) was evaluated using a pre- versus 3-month posttest design. Fifty-one participants completed pre- and posttest assessments. Participants reported significant reductions in drug intake and injection-related risk behavior. Participants also reported significant increases in planning skills, motivation/self-efficacy, and stigma management strategies, while reducing their exposure to drug withdrawal episodes and risky injection networks.

  12. THE STAYING SAFE INTERVENTION: TRAINING PEOPLE WHO INJECT DRUGS IN STRATEGIES TO AVOID INJECTION-RELATED HCV AND HIV INFECTION

    PubMed Central

    Mateu-Gelabert, Pedro; Gwadz, Marya Viorst; Guarino, Honoria; Sandoval, Milagros; Cleland, Charles M.; Jordan, Ashly; Hagan, Holly; Lune, Howard; Friedman, Samuel R.

    2014-01-01

    This pilot study explores the feasibility and preliminary efficacy of the Staying Safe Intervention, an innovative, strengths-based program to facilitate prevention of infection with the human immunodeficiency virus and with the hepatitis C virus among people who inject drugs (PWID). The authors explored changes in the intervention's two primary endpoints: (a) frequency and amount of drug intake, and (b) frequency of risky injection practices. We also explored changes in hypothesized mediators of intervention efficacy: planning skills, motivation/self-efficacy to inject safely, skills to avoid PWID-associated stigma, social support, drug-related withdrawal symptoms, and injection network size and risk norms. A 1-week, five-session intervention (10 hours total) was evaluated using a pre- versus 3-month posttest design. Fifty-one participants completed pre- and posttest assessments. Participants reported significant reductions in drug intake and injection-related risk behavior. Participants also reported significant increases in planning skills, motivation/self-efficacy, and stigma management strategies, while reducing their exposure to drug withdrawal episodes and risky injection networks. PMID:24694328

  13. The Role of Topical Antiseptic Agents Within Antimicrobial Stewardship Strategies for Prevention and Treatment of Surgical Site and Chronic Open Wound Infection

    PubMed Central

    Roberts, Christopher D.; Leaper, David J.; Assadian, Ojan

    2017-01-01

    Scope and Significance: The topical use of antiseptics for wound care has a role in an antimicrobial stewardship strategy. However, the details of this role need clarification. Further clinical research into the use of topical antiseptics in wound care would lower the risk of furthering antibiotic resistance and contribute to more effective antibiotic use. As part of this research, experimental and surveillance data are needed on the resistance and tolerance patterns associated with topical antiseptic use in wound infections. Objective: The development of antibiotic resistance presents global challenges in terms of patient harm and increased healthcare costs. The treatment of “at risk” and infected wounds contributes to this conundrum. Synergies between antibiotics and antiseptics and their appropriate combined use need exploration. Approach: A review of available evidence on the appropriateness of antiseptics as a fundamental component of antimicrobial stewardship strategies has been undertaken. Innovation: Opening up new ways of thinking and identifying gaps of knowledge will lead to optimizing justification of antimicrobial choices and combinations. This may lead to changes in practice in terms of solutions for the prevention and treatment of wound infection. Conclusion: Antiseptics are an integral part of antimicrobial stewardship strategies for the prevention and treatment of surgical site and chronic open wound infections. PMID:28224049

  14. The Contrasting Effects of Elevated CO2 on TYLCV Infection of Tomato Genotypes with and without the Resistance Gene, Mi-1.2.

    PubMed

    Guo, Huijuan; Huang, Lichao; Sun, Yucheng; Guo, Honggang; Ge, Feng

    2016-01-01

    Elevated atmospheric CO2 typically enhances photosynthesis of C3 plants and alters primary and secondary metabolites in plant tissue. By modifying the defensive signaling pathways in host plants, elevated CO2 could potentially affect the interactions between plants, viruses, and insects that vector viruses. R gene-mediated resistance in plants represents an efficient and highly specific defense against pathogens and herbivorous insects. The current study determined the effect of elevated CO2 on tomato plants with and without the nematode resistance gene Mi-1.2, which also confers resistance to some sap-sucking insects including whitefly, Bemisia tabaci. Furthermore, the subsequent effects of elevated CO2 on the performance of the vector whiteflies and the severity of Tomato yellow leaf curl virus (TYLCV) were also determined. The results showed that elevated CO2 increased the biomass, plant height, and photosynthetic rate of both the Moneymaker and the Mi-1.2 genotype. Elevated CO2 decreased TYLCV disease incidence and severity for Moneymaker plants but had the opposite effect on Mi-1.2 plants whether the plants were agroinoculated or inoculated via B. tabaci feeding. Elevated CO2 increased the salicylic acid (SA)-dependent signaling pathway on Moneymaker plants but decreased the SA-signaling pathway on Mi-1.2 plants when infected by TYLCV. Elevated CO2 did not significantly affect B. tabaci fitness or the ability of viruliferous B. tabaci to transmit virus regardless of plant genotype. The results indicate that elevated CO2 increases the resistance of Moneymaker plants but decreases the resistance of Mi-1.2 plants against TYLCV, whether the plants are agroinoculated or inoculated by the vector. Our results suggest that plant genotypes containing the R gene Mi-1.2 will be more vulnerable to TYLCV and perhaps to other plant viruses under elevated CO2 conditions.

  15. The Contrasting Effects of Elevated CO2 on TYLCV Infection of Tomato Genotypes with and without the Resistance Gene, Mi-1.2

    PubMed Central

    Huang, Lichao; Sun, Yucheng; Guo, Honggang; Ge, Feng

    2016-01-01

    Elevated atmospheric CO2 typically enhances photosynthesis of C3 plants and alters primary and secondary metabolites in plant tissue. By modifying the defensive signaling pathways in host plants, elevated CO2 could potentially affect the interactions between plants, viruses, and insects that vector viruses. R gene-mediated resistance in plants represents an efficient and highly specific defense against pathogens and herbivorous insects. The current study determined the effect of elevated CO2 on tomato plants with and without the nematode resistance gene Mi-1.2, which also confers resistance to some sap-sucking insects including whitefly, Bemisia tabaci. Furthermore, the subsequent effects of elevated CO2 on the performance of the vector whiteflies and the severity of Tomato yellow leaf curl virus (TYLCV) were also determined. The results showed that elevated CO2 increased the biomass, plant height, and photosynthetic rate of both the Moneymaker and the Mi-1.2 genotype. Elevated CO2 decreased TYLCV disease incidence and severity for Moneymaker plants but had the opposite effect on Mi-1.2 plants whether the plants were agroinoculated or inoculated via B. tabaci feeding. Elevated CO2 increased the salicylic acid (SA)-dependent signaling pathway on Moneymaker plants but decreased the SA-signaling pathway on Mi-1.2 plants when infected by TYLCV. Elevated CO2 did not significantly affect B. tabaci fitness or the ability of viruliferous B. tabaci to transmit virus regardless of plant genotype. The results indicate that elevated CO2 increases the resistance of Moneymaker plants but decreases the resistance of Mi-1.2 plants against TYLCV, whether the plants are agroinoculated or inoculated by the vector. Our results suggest that plant genotypes containing the R gene Mi-1.2 will be more vulnerable to TYLCV and perhaps to other plant viruses under elevated CO2 conditions. PMID:27881989

  16. Confronting the HIV epidemic in Asia and the Pacific: developing successful strategies to minimize the spread of HIV infection.

    PubMed

    Moodie, R; Aboagye-Kwarteng, T

    1993-12-01

    In Asia, the cumulative total of HIV-infected adults will reach 1.22 million by 1995, and, by 2000, the number is estimated to reach 11-45 million. The modes of transmission vary from country to country and include injecting drug users, commercial sex workers and their clients, commercial blood donors, hemophiliacs, and homosexuals. Social, cultural, and health factors also affect transmission, such as rites of passage to adulthood, lack of female autonomy, multiple sex partners, wars and civil unrest, and availability of drugs. The HIV epidemic has economic ramifications and causes, e.g., migrant worker camps, the sex industry, and rapid urbanization luring Burmese girls to Thailand. Governments must create an environment for behavior-change through financial, political, and legislative measures. Community organizations also play a role in prevention, as in programs initiated by a squatter settlement in Bangkok, where 36% of IV drug users were found to be HIV-positive. In Maharashtra State, India, peer-based prevention programs were developed for sex workers. Successful behavior change of individuals is based on redefinition of peer norms, understanding the danger and vulnerability to infection, and building confidence to change behavior. Successful programs require placing priority on HIV issues on the political agenda, negotiation and consensus-building skills, and competent program management. For instance, in Zimbabwe a project enlisted 380,000 people in 4500 education sessions within 2 years, and distributed 2.5 million condoms. Among sex workers, condom use increased from 5% to 50%. Implementation strategies include the provision of information and interpersonal education. In Zaire, mass media and social marketing efforts boosted condom sales from less than half a million in 1987 to over 20 million in 1991. The means to change behavior requires the availability of good quality condoms, disinfectants, and syringes. Furthermore, clinical management of

  17. An Economic Analysis of Strategies to Control Clostridium Difficile Transmission and Infection Using an Agent-Based Simulation Model

    PubMed Central

    Nelson, Richard E.; Jones, Makoto; Leecaster, Molly; Samore, Matthew H.; Ray, William; Huttner, Angela; Huttner, Benedikt; Khader, Karim; Stevens, Vanessa W.; Gerding, Dale; Schweizer, Marin L.; Rubin, Michael A.

    2016-01-01

    Background A number of strategies exist to reduce Clostridium difficile (C. difficile) transmission. We conducted an economic evaluation of “bundling” these strategies together. Methods We constructed an agent-based computer simulation of nosocomial C. difficile transmission and infection in a hospital setting. This model included the following components: interactions between patients and health care workers; room contamination via C. difficile shedding; C. difficile hand carriage and removal via hand hygiene; patient acquisition of C. difficile via contact with contaminated rooms or health care workers; and patient antimicrobial use. Six interventions were introduced alone and "bundled" together: (a) aggressive C. difficile testing; (b) empiric isolation and treatment of symptomatic patients; (c) improved adherence to hand hygiene and (d) contact precautions; (e) improved use of soap and water for hand hygiene; and (f) improved environmental cleaning. Our analysis compared these interventions using values representing 3 different scenarios: (1) base-case (BASE) values that reflect typical hospital practice, (2) intervention (INT) values that represent implementation of hospital-wide efforts to reduce C. diff transmission, and (3) optimal (OPT) values representing the highest expected results from strong adherence to the interventions. Cost parameters for each intervention were obtained from published literature. We performed our analyses assuming low, normal, and high C. difficile importation prevalence and transmissibility of C. difficile. Results INT levels of the “bundled” intervention were cost-effective at a willingness-to-pay threshold of $100,000/quality-adjusted life-year in all importation prevalence and transmissibility scenarios. OPT levels of intervention were cost-effective for normal and high importation prevalence and transmissibility scenarios. When analyzed separately, hand hygiene compliance, environmental decontamination, and empiric

  18. Real-time PCR strategy for the identification of Trypanosoma cruzi discrete typing units directly in chronically infected human blood.

    PubMed

    Muñoz-San Martín, Catalina; Apt, Werner; Zulantay, Inés

    2017-04-01

    The protozoan Trypanosoma cruzi is the causative agent of Chagas disease, a major public health problem in Latin America. This parasite has a complex population structure comprised by six or seven major evolutionary lineages (discrete typing units or DTUs) TcI-TcVI and TcBat, some of which have apparently resulted from ancient hybridization events. Because of the existence of significant biological differences between these lineages, strain characterization methods have been essential to study T. cruzi in its different vectors and hosts. However, available methods can be laborious and costly, limited in resolution or sensitivity. In this study, a new genotyping strategy by real-time PCR to identify each of the six DTUs in clinical blood samples have been developed and evaluated. Two nuclear (SL-IR and 18S rDNA) and two mitochondrial genes (COII and ND1) were selected to develop original primers. The method was evaluated with eight genomic DNA of T. cruzi populations belonging to the six DTUs, one genomic DNA of Trypanosoma rangeli, and 53 blood samples from individuals with chronic Chagas disease. The assays had an analytical sensitivity of 1-25fg of DNA per reaction tube depending on the DTU analyzed. The selectivity of trials with 20fg/μL of genomic DNA identified each DTU, excluding non-targets DTUs in every test. The method was able to characterize 67.9% of the chronically infected clinical samples with high detection of TcII followed by TcI. With the proposed original genotyping methodology, each DTU was established with high sensitivity after a single real-time PCR assay. This novel protocol reduces carryover contamination, enables detection of each DTU independently and in the future, the quantification of each DTU in clinical blood samples.

  19. Nosocomial urinary tract infections caused by extended-spectrum beta-lactamase uropathogens: Prevalence, pathogens, risk factors, and strategies for infection control

    PubMed Central

    Bouassida, Khaireddine; Jaidane, Mehdi; Bouallegue, Olfa; Tlili, Ghassen; Naija, Habiba; Mosbah, Ali Tahar

    2016-01-01

    Introduction: Our goal was to investigate the prevalence and antibiogram pattern of extended spectrum beta-lactamase (ESBL) production among uropathogens using isolates from urine samples collected at the Department of Urology in the Sahloul Hospital, Tunisia We also aimed to identify the risk factors for nosocomial urinary tract infections (UTIs) in patients who underwent transurethral resection of the prostate (TURP) and the measures for infection control. Methods: Laboratory records of a five-year period from January 2004 to December 2008 were submitted for retrospective analysis to determine the incidence of ESBL infections. A total of 276 isolates were collected. A case-control study involving comparisons between two groups of patients who underwent TURP was performed to determine the risk factors for ESBL infection. Group 1, designated case subjects, included 51 patients with nosocomial UTI after TURP. Group 2, designated control subjects, consisted of 58 randomly selected patients who underwent TURP without nosocomial UTI in the same period. Factors suspected to be implicated in the emergence of ESBL infection were compared between the two groups in order to identify risk factors for infection. A univariate regression analysis was performed, followed by a multivariate one. Results: The annual prevalence of ESBL infection ranged from 1.3–2.5%. After performing univariate and multivariate regression analysis, the main risk factors for ESBL infections were identified as: use of antibiotics the year preceding the admission, duration of catheter use, and bladder washout (p=0.012, p=0.019, and p<0.001. Conclusions: Urologists have to perform a good hemostasis, especially in endoscopic resections, in order to avoid bladder irrigation and bladder washout and to reduce the time of bladder catheterization, which is a strong risk factor of nosocomial UTIs. PMID:27330585

  20. Immunological and pharmacological strategies to reactivate HIV-1 from latently infected cells: a possibility for HIV-1 paediatric patients?

    PubMed

    Martínez-Bonet, M; Clemente, M I; Serramía, M J; Moreno, S; Muñoz, E; Muñoz-Fernández, M A

    2015-07-01

    The limitations to establishing a viral reservoir facilitated by early cART in children could play a critical role in achieving natural control of viral replication upon discontinuation of cART, which could be defined as 'functional cure'. Viral reservoirs could provide a persistent source of recrudescent viraemia after withdrawal of cART, despite temporary remission of HIV-1 infection, as observed in the 'Mississippi baby'. Intensification of cART has been proposed as a strategy to control residual replication and to diminish the reservoirs. The effects of cART intensification with maraviroc persisted after discontinuation of the drug in HIV-1-infected adults. However, in HIV-1-infected children, the emergence of CXCR4-using variants occurs very early, and the use of CCR5 antagonists in these children as intensification therapy may not be the best alternative. New treatments to eradicate HIV-1 are focused on the activation of viral production from latently infected cells to purge and clear HIV-1 reservoirs. This strategy involves the use of a wide range of small molecules called latency-reversing agents (LRAs). Histone deacetylase inhibitors (HDACi) such as givinostat, belinostat and panobinostat, and class I-selective HDACis that include oxamflatin, NCH-51 and romidepsin, are the most advanced in clinical testing for HIV-1 LRAs. Panobinostat and romidepsin show an efficient reactivation profile in J89GFP cells, a lymphocyte HIV-1 latently infected cell line considered a relevant model to study post-integration HIV-1 latency and reactivation. Clinical trials with panobinostat and romidepsin have been performed in children with other pathologies and it could be reasonable to design a clinical trial using these drugs in combination with cART in HIV-1-infected children.

  1. Reading, Perceptual Strategies and Contrastive Analysis

    ERIC Educational Resources Information Center

    Cowan, J. Ronayne

    1976-01-01

    Analyzes syntactic processes in three learning situations, Japanese reading English, Persians reading English and English speakers reading Hindi; discussed in terms of reading process and second language learning models. (Author/RM)

  2. Out of the Shadows: Building an Agenda and Strategies for Preventing HIV Infection and AIDS among Street and Homeless Youth.

    ERIC Educational Resources Information Center

    Center for Population Options, Washington, DC.

    This report summarizes the findings of a conference that examined the problem of Human Immunodeficiency Virus (HIV) infection and Acquired Immune Deficiency Syndrome (AIDS) among street and homeless youth. Street and homeless youth, by virtue of their circumstances and the behaviors they engage in, are at great risk of becoming infected with HIV,…

  3. Canine distemper virus (CDV) infection of ferrets as a model for testing Morbillivirus vaccine strategies: NYVAC- and ALVAC-based CDV recombinants protect against symptomatic infection.

    PubMed Central

    Stephensen, C B; Welter, J; Thaker, S R; Taylor, J; Tartaglia, J; Paoletti, E

    1997-01-01

    Canine distemper virus (CDV) infection of ferrets causes an acute systemic disease involving multiple organ systems, including the respiratory tract, lymphoid system, and central nervous system (CNS). We have tested candidate CDV vaccines incorporating the fusion (F) and hemagglutinin (HA) proteins in the highly attenuated NYVAC strain of vaccinia virus and in the ALVAC strain of canarypox virus, which does not productively replicate in mammalian hosts. Juvenile ferrets were vaccinated twice with these constructs, or with an attenuated live-virus vaccine, while controls received saline or the NYVAC and ALVAC vectors expressing rabies virus glycoprotein. Control animals did not develop neutralizing antibody and succumbed to distemper after developing fever, weight loss, leukocytopenia, decreased activity, conjunctivitis, an erythematous rash typical of distemper, CNS signs, and viremia in peripheral blood mononuclear cells (as measured by reverse transcription-PCR). All three CDV vaccines elicited neutralizing titers of at least 1:96. All vaccinated ferrets survived, and none developed viremia. Both recombinant vaccines also protected against the development of symptomatic distemper. However, ferrets receiving the live-virus vaccine lost weight, became lymphocytopenic, and developed the erythematous rash typical of CDV. These data show that ferrets are an excellent model for evaluating the ability of CDV vaccines to protect against symptomatic infection. Because the pathogenesis and clinical course of CDV infection of ferrets is quite similar to that of other Morbillivirus infections, including measles, this model will be useful in testing new candidate Morbillivirus vaccines. PMID:8995676

  4. Evidence of bovine viral diarrhea virus infection in three species of sympatric wild ungulates in Nevada: Life history strategies may maintain endemic infections in wild populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Evidence for bovine viral diarrhea virus (BVDV) infection was detected in 2009-10 during a pneumonia die-off in Rocky Mountain bighorn sheep (Ovis canadensis canadensis), and sympatric mountain goats (Oreamnos americanum) in adjacent mountain ranges in Elko County, Nevada. Seroprevalence to BVDV-1 ...

  5. Canine distemper virus (CDV) infection of ferrets as a model for testing Morbillivirus vaccine strategies: NYVAC- and ALVAC-based CDV recombinants protect against symptomatic infection.

    PubMed

    Stephensen, C B; Welter, J; Thaker, S R; Taylor, J; Tartaglia, J; Paoletti, E

    1997-02-01

    Canine distemper virus (CDV) infection of ferrets causes an acute systemic disease involving multiple organ systems, including the respiratory tract, lymphoid system, and central nervous system (CNS). We have tested candidate CDV vaccines incorporating the fusion (F) and hemagglutinin (HA) proteins in the highly attenuated NYVAC strain of vaccinia virus and in the ALVAC strain of canarypox virus, which does not productively replicate in mammalian hosts. Juvenile ferrets were vaccinated twice with these constructs, or with an attenuated live-virus vaccine, while controls received saline or the NYVAC and ALVAC vectors expressing rabies virus glycoprotein. Control animals did not develop neutralizing antibody and succumbed to distemper after developing fever, weight loss, leukocytopenia, decreased activity, conjunctivitis, an erythematous rash typical of distemper, CNS signs, and viremia in peripheral blood mononuclear cells (as measured by reverse transcription-PCR). All three CDV vaccines elicited neutralizing titers of at least 1:96. All vaccinated ferrets survived, and none developed viremia. Both recombinant vaccines also protected against the development of symptomatic distemper. However, ferrets receiving the live-virus vaccine lost weight, became lymphocytopenic, and developed the erythematous rash typical of CDV. These data show that ferrets are an excellent model for evaluating the ability of CDV vaccines to protect against symptomatic infection. Because the pathogenesis and clinical course of CDV infection of ferrets is quite similar to that of other Morbillivirus infections, including measles, this model will be useful in testing new candidate Morbillivirus vaccines.

  6. Differential susceptibility of adults and nymphs of Blattella germanica (L.) (Blattodea: Blattellidae) to infection by Metarhizium anisopliae and assessment of delivery strategies.

    PubMed

    Lopes, R B; Alves, S B

    2011-01-01

    Microbial insecticides for cockroach control, such as those containing entomopathogenic fungi, may be an alternative to reduce contamination by chemicals in housing and food storage environments. Virulence of isolate ESALQ1037 belonging to the Metarhizium anisopliae complex against nymphs and adults of Blattella germanica (L.), and its infectivity following exposure of insects to a contaminated surface or to M. anisopliae-bait were determined under laboratory conditions. Estimated LD50 15 d following topical inoculation was 2.69 x 10(5) conidia per adult, whereas for nymphs the maximum mortality was lower than 50%. Baits amended with M. anisopliae conidia had no repellent effect on targets; adult mortality was inferior to 25%, and nymphs were not susceptible. All conidia found in the digestive tract of M. anisopliae-bait fed cockroaches were unviable, and bait-treated insects that succumbed to fungal infection showed a typical mycelial growth on mouthparts and front legs, but not on the hind body parts. As opposed to baits, the use of a M. anisopliae powdery formulation for surface treatment was effective in attaining high mortality rates of B. germanica. Both nymphs and adults were infected when this delivery strategy was used, and mycelia growth occurred all over the body surface. Our results suggest that the development of powders or similar formulations of M. anisopliae to control B. germanica may provide faster and better results than some of the strategies based on baits currently available.

  7. Homologous prime-boost strategy with TgPI-1 improves the immune response and protects highly susceptible mice against chronic Toxoplasma gondii infection.

    PubMed

    Sánchez, Vanesa R; Fenoy, Ignacio M; Picchio, Mariano S; Soto, Ariadna S; Arcon, Nadia; Goldman, Alejandra; Martin, Valentina

    2015-10-01

    Subunit-based vaccines are safer than live or attenuated pathogen vaccines, although they are generally weak immunogens. Thus, proper combination of immunization strategies and adjuvants are needed to increase their efficacy. We have previously protected C3H/HeN mice from Toxoplasma gondii infection by immunization with the serine protease inhibitor-1 (TgPI-1) in combination with alum. In this work, we explore an original vaccination protocol that combines administration of recombinant TgPI-1 by intradermal and intranasal routes in order to enhance protection in the highly susceptible C57BL/6 strain. Mice primed intradermally with rTgPI-1 plus alum and boosted intranasally with rTgPI-1 plus CpG-ODN elicited a strong specific Th1/Th2 humoral response, along with a mucosal immune response characterized by specific-IgA in intestinal lavages. A positive cellular response of mesentheric lymph node cells and Th1/Th2 cytokine secretion in the ileon were also detected. When immunized mice were challenged with the cystogenic Me49 T. gondii strain, they displayed up to 62% reduction in brain parasite burden. Moreover, adoptive transfer of mesenteric lymph node cells from vaccinated to naïve mice induced significant protection against infection. These results demonstrate that this strategy that combines the administration of TgPI-1 by two different routes, intradermal priming and intranasal boost, improves protective immunity against T. gondii chronic infection in highly susceptible mice.

  8. Evidence of Bovine viral diarrhea virus Infection in Three Species of Sympatric Wild Ungulates in Nevada: Life History Strategies May Maintain Endemic Infections in Wild Populations

    PubMed Central

    Wolff, Peregrine L.; Schroeder, Cody; McAdoo, Caleb; Cox, Mike; Nelson, Danielle D.; Evermann, James F.; Ridpath, Julia F.

    2016-01-01

    Evidence for bovine viral diarrhea virus (BVDV) infection was detected in 2009–2010 while investigating a pneumonia die-off in Rocky Mountain bighorn sheep (Ovis canadensis, canadensis), and sympatric mountain goats (Oreamnos americanum) in adjacent mountain ranges in Elko County, Nevada. Seroprevalence to BVDV-1 was 81% (N = 32) in the bighorns and 100% (N = 3) in the mountain goats. Serosurveillance from 2011 to 2015 of surviving bighorns and mountain goats as well as sympatric mule deer (Odocoileus hemionus), indicated a prevalence of 72% (N = 45), 45% (N = 51), and 51% (N = 342) respectively. All species had antibody titers to BVDV1 and BVDV2. BVDV1 was isolated in cell culture from three bighorn sheep and a mountain goat kid. BVDV2 was isolated from two mule deer. Six deer (N = 96) sampled in 2013 were positive for BVDV by antigen-capture ELISA on a single ear notch. Wild ungulates and cattle concurrently graze public and private lands in these two mountain ranges, thus providing potential for interspecies viral transmission. Like cattle, mule deer, mountain goats, and bighorn sheep can be infected with BVDV and can develop clinical disease including immunosuppression. Winter migration patterns that increase densities and species interaction during the first and second trimester of gestation may contribute to the long term maintenance of the virus in these wild ungulates. More studies are needed to determine the population level impacts of BVDV infection on these three species. PMID:27014215

  9. Evidence of Bovine viral diarrhea virus Infection in Three Species of Sympatric Wild Ungulates in Nevada: Life History Strategies May Maintain Endemic Infections in Wild Populations.

    PubMed

    Wolff, Peregrine L; Schroeder, Cody; McAdoo, Caleb; Cox, Mike; Nelson, Danielle D; Evermann, James F; Ridpath, Julia F

    2016-01-01

    Evidence for bovine viral diarrhea virus (BVDV) infection was detected in 2009-2010 while investigating a pneumonia die-off in Rocky Mountain bighorn sheep (Ovis canadensis, canadensis), and sympatric mountain goats (Oreamnos americanum) in adjacent mountain ranges in Elko County, Nevada. Seroprevalence to BVDV-1 was 81% (N = 32) in the bighorns and 100% (N = 3) in the mountain goats. Serosurveillance from 2011 to 2015 of surviving bighorns and mountain goats as well as sympatric mule deer (Odocoileus hemionus), indicated a prevalence of 72% (N = 45), 45% (N = 51), and 51% (N = 342) respectively. All species had antibody titers to BVDV1 and BVDV2. BVDV1 was isolated in cell culture from three bighorn sheep and a mountain goat kid. BVDV2 was isolated from two mule deer. Six deer (N = 96) sampled in 2013 were positive for BVDV by antigen-capture ELISA on a single ear notch. Wild ungulates and cattle concurrently graze public and private lands in these two mountain ranges, thus providing potential for interspecies viral transmission. Like cattle, mule deer, mountain goats, and bighorn sheep can be infected with BVDV and can develop clinical disease including immunosuppression. Winter migration patterns that increase densities and species interaction during the first and second trimester of gestation may contribute to the long term maintenance of the virus in these wild ungulates. More studies are needed to determine the population level impacts of BVDV infection on these three species.

  10. Deciphering Adaptation Strategies of the Epidemic Clostridium difficile 027 Strain during Infection through In Vivo Transcriptional Analysis

    PubMed Central

    Kansau, Imad; Barketi-Klai, Amira; Monot, Marc; Hoys, Sandra; Dupuy, Bruno; Janoir, Claire; Collignon, Anne

    2016-01-01

    Clostridium difficile is responsible for a wide spectrum of infection from asymptomatic carriage to severe, relapsing colitis. Since 2003, C. difficile infections have increased with a higher morbidity and mortality due to the emergence of epidemic and hypervirulent C. difficile strains such as those of the epidemic lineage 027/BI/NAP1. To decipher the hypervirulence and epidemicity of 027 strains, we analyzed gene expression profiles of the R20291 027 strain using a monoxenic mouse model during the first 38h of infection. A total of 741 genes were differentially expressed during the course of infection. They are mainly distributed in functional categories involved in host adaptation. Several genes of PTS and ABC transporters were significantly regulated during the infection, underlying the ability of strain R20291 to adapt its metabolism according to nutrient availability in the digestive tract. In this animal model, despite the early sporulation process, sporulation efficiency seems to indicate that growth of R20291 vegetative cells versus spores were favored during infection. The bacterial mechanisms associated to adaptability and flexibility within the gut environment, in addition to the virulence factor expression and antibiotic resistance, should contribute to the epidemicity and hypervirulence of the C. difficile 027 strains. PMID:27351947

  11. Productive infection of Piscirickettsia salmonis in macrophages and monocyte-like cells from rainbow trout, a possible survival strategy.

    PubMed

    Rojas, Verónica; Galanti, Norbel; Bols, Niels C; Marshall, Sergio H

    2009-10-15

    Piscirickettsia salmonis is the etiologic agent of the salmonid rickettsial septicemia (SRS), an endemic disease which causes significant losses in salmon production. This intracellular bacterium is normally cultured in salmonid epithelial cell lines inducing characteristic cytopathic effects (CPEs). In this study we demonstrate that P. salmonis is able to infect, survive, replicate, and propagate in the macrophages/monocytes cell line RTS11 derived from rainbow trout spleen, without inducing the characteristic CPEs and the host cells showing the same expression levels as non-infected control cell. On the other hand, bacteria were capable of expressing specific proteins within infected cells. Infected macrophages cease proliferation and a fraction of them detached from the plate, transform to non-adhesive, monocyte-like cells with proliferative activity. Productive infection of P. salmonis into salmonid macrophage/monocyte cells in culture provides an excellent model for the study of host-pathogen interactions, almost unknown in the case of P. salmonis. Our results suggest that the infection of cells from the salmonid innate immune system without inducing an important cell death response should lead to the persistence of the bacteria and consequently their dissemination to other tissues, favoring the evasion of the first line of defense against pathogens.

  12. A Novel Strategy to Increase Identification of African-Born People With Chronic Hepatitis B Virus Infection in the Chicago Metropolitan Area, 2012–2014

    PubMed Central

    Song, Sharon; Johnson, Matthew; Harris, Aaron M.; Kaufman, Gary I.; Freedman, David; Quinn, Michael T.; Kim, Karen E.

    2016-01-01

    Introduction Most research on hepatitis B virus (HBV) infection in the United States is limited to Asian populations, despite an equally high prevalence among African immigrants. The purpose of this study was to determine testing and detection rates of HBV infection among African-born people residing in the Chicago metropolitan area. Methods A hepatitis education and prevention program was developed in collaboration with academic, clinical, and community partners for immigrant and refugee populations at risk for HBV infection. Community health workers implemented chain referral sampling, a novel strategy for recruiting hard-to-reach participants, targeting African-born participants. Participants were tested in both clinical and nonclinical settings. To assess infection status, blood samples were obtained for hepatitis B surface antigen (HBsAg), core antibody, and surface antibody testing. Demographic information was collected on age, sex, health insurance status, country of origin, and years residing in the United States. Participants were notified of testing results, and HBsAg-positive participants were referred for follow-up medical care. Results Of 1,000 African-born people who received education, 445 (45%) agreed to participate in HBV screening. There were 386 (87%) participants tested in clinical and 59 (13%) tested in nonclinical sites. Compared with participants who were tested in clinical settings, participants tested in nonclinical settings were older, were less likely to have health insurance, and had lived in the United States longer (P < .005 for each). Of these, most were from the Democratic Republic of the Congo (14%), Nigeria (13%), Ghana (11%), Somalia (11%), or Ethiopia (10%). There were 35 (8%) HBsAg-positive people, 37% had evidence of past infection, and 29% were immune. Conclusions Chain referral sampling identified many at-risk African-born people with chronic HBV infection. The large proportion of HBsAg-positive people in this sample

  13. Recurrent Urinary Tract Infections Among Women: Comparative Effectiveness of 5 Prevention and Management Strategies Using a Markov Chain Monte Carlo Model

    PubMed Central

    Eells, Samantha J.; Bharadwa, Kiran; McKinnell, James A.; Miller, Loren G.

    2014-01-01

    Background. Recurrent urinary tract infections (UTIs) are a common problem among women. However, comparative effectiveness strategies for managing recurrent UTIs are lacking. Methods. We performed a systematic literature review of management of women experiencing ≥3 UTIs per year. We then developed a Markov chain Monte Carlo model of recurrent UTI for each management strategy with ≥2 adequate trials published. We simulated a cohort that experienced 3 UTIs/year and a secondary cohort that experienced 8 UTIs/year. Model outcomes were treatment efficacy, patient and payer cost, and health-related quality of life. Results. Five strategies had ≥2 clinical trials published: (1) daily antibiotic (nitrofurantoin) prophylaxis; (2) daily estrogen prophylaxis; (3) daily cranberry prophylaxis; (4) acupuncture prophylaxis; and (5) symptomatic self-treatment. In the 3 UTIs/year model, nitrofurantoin prophylaxis was most effective, reducing the UTI rate to 0.4 UTIs/year, and the most expensive to the payer ($821/year). All other strategies resulted in payer cost savings but were less efficacious. Symptomatic self-treatment was the only strategy that resulted in patient cost savings, and was the most favorable strategy in term of cost per quality-adjusted life-year (QALY) gained. Conclusions. Daily antibiotic use is the most effective strategy for recurrent UTI prevention compared to daily cranberry pills, daily estrogen therapy, and acupuncture. Cost savings to payers and patients were seen for most regimens, and improvement in QALYs were seen with all. Our findings provide clinically meaningful data to guide the physician–patient partnership in determining a preferred method of prevention for this common clinical problem. PMID:24065333

  14. An intersectional approach for understanding the vulnerabilities of English-speaking heterosexual Caribbean youth to HIV/AIDS and sexually transmitted infections: Prevention and intervention strategies

    PubMed Central

    Sutherland, Marcia Elizabeth

    2016-01-01

    Caribbean youth comprise about 30 percent of the English-speaking Caribbean population, and about 81,000 Caribbean and Latin American youth are HIV infected. AIDS is the leading cause of death for 15- to 24-year-old English-speaking Caribbean youth. This article relies on intersectionality theory in the assessment of the macro-level, or structural variables, and micro-level, or individual level, variables that influence the risk-taking sexual behaviors of heterosexual English-speaking Caribbean youth and increase their vulnerability to HIV/sexually transmitted infections. This article offers macro- and micro-level prevention/intervention strategies for reducing the prevalence of sexually transmitted infections in English-speaking Caribbean youth, including the promotion of condom use, voluntary male circumcision, and HIV testing and counseling. Suggestions are offered for future research investigations to explore the contributing factors to youth’s vulnerability to sexually transmitted infections and to empirically verify the relationship between and among variables that account for desired outcomes, including decreases in risky sexual behaviors. PMID:28070411

  15. Lesser-known or hidden reservoirs of infection and implications for adequate prevention strategies: Where to look and what to look for

    PubMed Central

    Bloomfield, Sally; Exner, Martin; Flemming, Hans-Curt; Goroncy-Bermes, Peter; Hartemann, Philippe; Heeg, Peter; Ilschner, Carola; Krämer, Irene; Merkens, Wolfgang; Oltmanns, Peter; Rotter, Manfred; Rutala, William A.; Sonntag, Hans-Günther; Trautmann, Matthias

    2015-01-01

    In developing hygiene strategies, in recent years, the major focus has been on the hands as the key route of infection transmission. However, there is a multitude of lesser-known and underestimated reservoirs for microorganisms which are the triggering sources and vehicles for outbreaks or sporadic cases of infection. Among those are water reservoirs such as sink drains, fixtures, decorative water fountains and waste-water treatment plants, frequently touched textile surfaces such as private curtains in hospitals and laundry, but also transvaginal ultrasound probes, parenteral drug products, and disinfectant wipe dispensers. The review of outbreak reports also reveals Gram-negative and multiple-drug resistant microorganisms to have become an increasingly frequent and severe threat in medical settings. In some instances, the causative organisms are particularly difficult to identify because they are concealed in biofilms or in a state referred to as viable but nonculturable, which eludes conventional culture media-based detection methods. There is an enormous preventative potential in these insights, which has not been fully tapped. New and emerging pathogens, novel pathogen detection methods, and hidden reservoirs of infection should hence be given special consideration when designing the layout of buildings and medical devices, but also when defining the core competencies for medical staff, establishing programmes for patient empowerment and education of the general public, and when implementing protocols for the prevention and control of infections in medical, community and domestic settings. PMID:25699227

  16. An intersectional approach for understanding the vulnerabilities of English-speaking heterosexual Caribbean youth to HIV/AIDS and sexually transmitted infections: Prevention and intervention strategies.

    PubMed

    Sutherland, Marcia Elizabeth

    2016-07-01

    Caribbean youth comprise about 30 percent of the English-speaking Caribbean population, and about 81,000 Caribbean and Latin American youth are HIV infected. AIDS is the leading cause of death for 15- to 24-year-old English-speaking Caribbean youth. This article relies on intersectionality theory in the assessment of the macro-level, or structural variables, and micro-level, or individual level, variables that influence the risk-taking sexual behaviors of heterosexual English-speaking Caribbean youth and increase their vulnerability to HIV/sexually transmitted infections. This article offers macro- and micro-level prevention/intervention strategies for reducing the prevalence of sexually transmitted infections in English-speaking Caribbean youth, including the promotion of condom use, voluntary male circumcision, and HIV testing and counseling. Suggestions are offered for future research investigations to explore the contributing factors to youth's vulnerability to sexually transmitted infections and to empirically verify the relationship between and among variables that account for desired outcomes, including decreases in risky sexual behaviors.

  17. Chronic Periprosthetic Hip Joint Infection. A Retrospective, Observational Study on the Treatment Strategy and Prognosis in 130 Non-Selected Patients

    PubMed Central

    Troelsen, Anders; Søballe, Kjeld

    2016-01-01

    Introduction Limited information is available regarding the treatment strategy and prognosis of non-selected patients treated for chronic periprosthetic hip joint infection. Such information is important as no head-to-head studies on treatment strategies are available. The purpose of this study is to report on the treatment strategy and prognosis of a non-selected, consecutive patient population Methods We identified 130 patients in the National Patient Registry, consecutively treated for a chronic periprosthetic hip joint infection between 2003–2008 at 11 departments of orthopaedic surgery. We extracted information regarding patient demographics, treatment and outcome. 82 patients were re-implanted in a two-stage revision (national standard), the remaining 48 were not re-implanted in a two-stage revision. We were able to collect up-to-date information on all patients to date of death or medical chart review with a minimum of 5 years follow-up by the nationwide electronic patient record system Results After primary revision surgery, 53 patients (41%) had a spacer in situ, 64 (50%) had a resection arthroplasty and 13 (9%) did not have the infected implant removed. 63% were re-implanted in a two-stage revision. Re-implantation was performed after an interim period of 14 weeks (IQR 10–18). Patients re-implanted were younger (p-value 0.0006), had a lower CCS score (p-value 0.005), a lower ASA score (p-value 0.0001) and a 68% lower mortality risk in the follow-up period (p-value <0.00001). After adjusting for selected confounders, the mortality risk was no longer significantly different. The 5-year re-infection rate after re-implantation was 14.6% (95%CI 8.0–23.1). Re-infections occurred mainly within 3 years of follow-up. The overall 1-year survival rate was 92% (95%CI 86–96) and the overall 5-year survival rate was 68% (95%CI 59–75). The 5-year survival rate after a two-stage revision was 82% (95%CI 71–89) and in those not re-implanted 45% (95%CI 30–58

  18. Redeploying β-Lactam Antibiotics as a Novel Antivirulence Strategy for the Treatment of Methicillin-Resistant Staphylococcus aureus Infections

    SciTech Connect

    Waters, Elaine M.; Rudkin, Justine K.; Coughlan, Simone; Clair, Geremy C.; Adkins, Joshua N.; Gore, Suzanna; Xia, Guoqing; Black, Nikki S.; Downing, Tim; O'Neill, Eoghan; Kadioglu, Aras; O'Gara, James P.

    2016-11-14

    Innovative approaches to the use of existing antibiotics is an important strategy in efforts to address the escalating antimicrobial resistance crisis. Here, the beta-lactam antibiotic oxacillin was shown to significantly attenuate the virulence of MRSA despite the pathogen being resistant to this drug. Oxacillin-mediated repression of the Agr quorum-sensing system and altered cell wall architecture, was associated with reduced cytolytic activity and increased susceptibility to host killing. These findings support the inclusion of -lactam antibiotics as an adjunctive anti-virulence therapy in the treatment of MRSA infections, with the potential to significantly improve patient outcomes in a safe, cost effective manner.

  19. [Physiopathology of nephropathy studied with contrast media].

    PubMed

    Morales Buenrostro, L E; Tellez Zenteno, J F; Torre Delgadillo, A

    2000-01-01

    For the technological advances in diagnostic and therapeutic procedures, the use of intravenous contrast media in the hospital is more and more frequent. It can produce acute renal failure secondary to its nephrotoxicity known as contrast media nephropathy. This review describes the pathophysiologic mechanisms of contrast media injury, including cytotoxicity caused by hyperosmoloarity of contrast media, the hemodynamic factors and the role of the renin-angiotensin system, prostaglandins, oxygen free radicals, endothelin-1, adenosine, nitric oxide and others. The understanding of this information is of vital importance for the development of prophylactic strategies for contrast media nephropathy.

  20. Interventions to Address Chronic Disease and HIV: Strategies to Promote Exercise and Nutrition Among HIV-Infected Individuals

    PubMed Central

    Botros, Diana; Somarriba, Gabriel; Neri, Daniela; Miller, Tracie L.

    2012-01-01

    Food insecurity, micronutrient deficits, dyslipidemia, insulin resistance, obesity, cardiovascular disease, and bone disorders complicate the treatment of HIV infection. Nutrition and exercise interventions can be effective in ameliorating these symptoms that are associated with HIV and antiretroviral therapy (ART). In this literature review, we examine the most recent nutrition and exercise interventions for HIV-infected patients. Macronutrient supplementation can be useful in treating malnutrition and wasting. Multivitamin (vitamin B complex, vitamin C, and vitamin E) supplements and vitamin D may improve quality of life and decrease morbidity and mortality. Nutritional counseling and exercise interventions are effective for treating obesity, fat redistribution, and metabolic abnormalities. Physical activity interventions improve body composition, strength, and fitness in HIV-infected individuals. Taken collectively, the evidence suggests that a proactive approach to nutrition and physical activity guidance and interventions can improve outcomes and help abrogate the adverse metabolic, cardiovascular, and psychological consequences of HIV and its treatments. PMID:22933247

  1. What is the best strategy for enhancing the effects of topically applied ozonated oils in cutaneous infections?

    PubMed

    Zanardi, I; Burgassi, S; Paccagnini, E; Gentile, M; Bocci, V; Travagli, V

    2013-01-01

    Owing to diabetes, atherosclerosis, and ageing, there are several million patients undergoing skin lesions degenerated into infected ulcers with very little tendency to heal and implying a huge socioeconomical cost. Previous medical experience has shown that the daily application of ozonated oil eliminates the infection and promotes a rapid healing. The purpose of the study is the optimization of the antimicrobial effect of ozonated oils by testing in vitro four bacterial species and one yeast without or in the presence of different amounts of human serum. The results obtained suggest that a gentle and continuous removal of debris and exudate is an essential condition for the potent bactericidal effect of ozonated oils. In fact, even small amounts of human serum inactivate ozone derivatives and protect bacteria. The application of ozonated oil preparations is very promising in a variety of skin and mucosal infections. Moreover, ozonated oils are far less expensive than antibiotic preparations.

  2. What Is the Best Strategy for Enhancing the Effects of Topically Applied Ozonated Oils in Cutaneous Infections?

    PubMed Central

    Zanardi, I.; Burgassi, S.; Paccagnini, E.; Gentile, M.; Bocci, V.; Travagli, V.

    2013-01-01

    Owing to diabetes, atherosclerosis, and ageing, there are several million patients undergoing skin lesions degenerated into infected ulcers with very little tendency to heal and implying a huge socioeconomical cost. Previous medical experience has shown that the daily application of ozonated oil eliminates the infection and promotes a rapid healing. The purpose of the study is the optimization of the antimicrobial effect of ozonated oils by testing in vitro four bacterial species and one yeast without or in the presence of different amounts of human serum. The results obtained suggest that a gentle and continuous removal of debris and exudate is an essential condition for the potent bactericidal effect of ozonated oils. In fact, even small amounts of human serum inactivate ozone derivatives and protect bacteria. The application of ozonated oil preparations is very promising in a variety of skin and mucosal infections. Moreover, ozonated oils are far less expensive than antibiotic preparations. PMID:24282818

  3. Interventions to address chronic disease and HIV: strategies to promote exercise and nutrition among HIV-infected individuals.

    PubMed

    Botros, Diana; Somarriba, Gabriel; Neri, Daniela; Miller, Tracie L

    2012-12-01

    Food insecurity, micronutrient deficits, dyslipidemia, insulin resistance, obesity, cardiovascular disease, and bone disorders complicate the treatment of HIV infection. Nutrition and exercise interventions can be effective in ameliorating these symptoms that are associated with HIV and antiretroviral therapy (ART). In this literature review, we examine the most recent nutrition and exercise interventions for HIV-infected patients. Macronutrient supplementation can be useful in treating malnutrition and wasting. Multivitamin (vitamin B complex, vitamin C, and vitamin E) supplements and vitamin D may improve quality of life and decrease morbidity and mortality. Nutritional counseling and exercise interventions are effective for treating obesity, fat redistribution, and metabolic abnormalities. Physical activity interventions improve body composition, strength, and fitness in HIV-infected individuals. Taken collectively, the evidence suggests that a proactive approach to nutrition and physical activity guidance and interventions can improve outcomes and help abrogate the adverse metabolic, cardiovascular, and psychological consequences of HIV and its treatments.

  4. Analysis of ventilator-associated pneumonia infection route by genome macrorestriction-pulsed-field gel electrophoresis and its prevention with combined nursing strategies.

    PubMed

    Wang, Xiaodong; Wang, Junping; Li, Jing; Wang, Jing

    2014-12-01

    The aim of the present study was to explore the infection route of ventilator-associated pneumonia (VAP) and assess the effectiveness of a combined nursing strategy to prevent VAP in intensive care units. Bacteria from the gastric juice and drainage from the hypolarynx and lower respiratory tracts of patients with VAP were analyzed using genome macrorestriction-pulsed-field gel electrophoresis (GM-PFGE). A total of 124 patients with tracheal intubation were placed in the intervention group and were treated with a combined nursing strategy, comprising mosapride (gastric motility stimulant) administration and semi-reclining positioning. A total of 112 intubated patients were placed in the control group and received routine nursing care. The incidence rate of VAP, days of ventilation and mortality rate of patients were compared between the two groups. The GM-PFGE fingerprinting results of three strains of Pseudomonas aeruginosa from the gastric juice, subglottic secretion drainage and drainage of the lower respiratory tract in patients with VAP were similar across groups. The number of days spent on a ventilator by patients in the intervention group (7.37±5.32 days) was lower compared with that by patients in the control group (12.34±4.98 days) (P<0.05). The incidence rate of VAP was reduced from 40.81 to 21.25% following intervention with the combined nursing strategy (P<0.05); furthermore, the mortality rate of intubated patients in the intervention group was 29.46%, a significant reduction compared with the 41.94% mortality rate observed in the control group (P<0.05). Gastroesophageal reflux (GER) was confirmed as one of the infection routes for VAP. The combined nursing strategy of gastric motility stimulant administration and the adoption of a semi-reclining position was effective in preventing VAP by reducing the occurrence of GER.

  5. HIV treatment as prevention: debate and commentary--will early infection compromise treatment-as-prevention strategies?

    PubMed

    Cohen, Myron S; Dye, Christopher; Fraser, Christophe; Miller, William C; Powers, Kimberly A; Williams, Brian G

    2012-01-01

    Universal HIV testing and immediate antiretroviral therapy for infected individuals has been proposed as a way of reducing the transmission of HIV and thereby bringing the HIV epidemic under control. It is unclear whether transmission during early HIV infection--before individuals are likely to have been diagnosed with HIV and started on antiretroviral therapy--will compromise the effectiveness of treatment as prevention. This article presents two opposing viewpoints by Powers, Miller, and Cohen, and Williams and Dye, followed by a commentary by Fraser.

  6. Relationship Dynamics and Sexual Risk Reduction Strategies Among Heterosexual Young Adults: A Qualitative Study of Sexually Transmitted Infection Clinic Attendees at an Urban Chicago Health Center.

    PubMed

    Hotton, Anna L; French, Audrey L; Hosek, Sybil G; Kendrick, Sabrina R; Lemos, Diana; Brothers, Jennifer; Kincaid, Stacey L; Mehta, Supriya D

    2015-12-01

    Few studies have examined risk-reduction alternatives to consistent condom use for HIV prevention among heterosexual young adults. We used qualitative methodology to explore risk reduction strategies and contextual factors influencing attempts to reduce risk in an urban, high morbidity sexually transmitted infection (STI) clinic. Focus groups were conducted October-December 2014 with heterosexually identified men (n = 13) and women (n = 20) aged 18-29 seeking STI screening at an urban clinic. Groups were audio recorded, transcribed verbatim, and analyzed for thematic content using Atlas.ti software. Quantitative information included sociodemographics, HIV/STI testing history, and 6-month sexual behaviors. Among 33 predominantly African-American participants with a median age of 22, risk-reduction strategies included monogamy agreements, selective condom use with casual and high-risk partners, and frequent HIV/STI testing, though testing was commonly used as a post-hoc reassurance after risk exposure. Many men and women used implicit risk assessment strategies due to mistrust or difficulty communicating. Concurrency was common but rarely discussed within partnerships. Despite attempts to reduce risk, monogamy agreements were often poorly adhered to and not openly discussed. Alcohol and substance use frequently interfered with safer sexual decisions. Participants were aware of HIV/STI risk and commonly practiced risk-reduction strategies, but acknowledged faulty assumptions and poor adherence. This work provides insights into risk-reduction approaches that are already used and may be strengthened as part of effective HIV/STI prevention interventions.

  7. New Strategies for Prevention and Therapy of Cytomegalovirus Infection and Disease in Solid-Organ Transplant Recipients

    PubMed Central

    Sia, Irene G.; Patel, Robin

    2000-01-01

    In the past three decades since the inception of human organ transplantation, cytomegalovirus (CMV) has gained increasing clinical import because it is a common pathogen in the immunocompromised transplant recipient. Patients may suffer from severe manifestations of this infection along with the threat of potential fatality. Additionally, the dynamic evolution of immunosuppressive and antiviral agents has brought forth changes in the natural history of CMV infection and disease. Transplant physicians now face the daunting task of recognizing and managing the changing spectrum of CMV infection and its consequences in the organ recipient. For the microbiology laboratory, the emphasis has been geared toward the development of more sophisticated detection assays, including methods to detect emerging antiviral resistance. The discovery of novel antiviral chemotherapy is an important theme of clinical research. Investigations have also focused on preventative measures for CMV disease in the solid-organ transplant population. In all, while much has been achieved in the overall management of CMV infection, the current understanding of CMV pathogenesis and therapy still leaves much to be learned before success can be claimed. PMID:10627493

  8. Central line-associated blood stream infections in pediatric ICUs: Longitudinal trends and compliance with bundle strategies

    PubMed Central

    Edwards, Jeffrey D; Herzig, Carolyn TA; Liu, Hangsheng; Pogorzelska-Maziarz, Monika; Zachariah, Philip; Dick, Andrew W; Saiman, Lisa; Stone, Patricia W; Furuya, E Yoko

    2015-01-01

    Background Knowing the temporal trend central line-associated bloodstream infection (CLABSI) rates among U.S. pediatric intensive care units (PICU), the current extent of CL bundle compliance, and the impact of compliance on rates is necessary to understand what has been accomplished and can be improved in CLABSI prevention. Methods Longitudinal study of PICUs in National Healthcare Safety Network hospitals and a cross-sectional survey of directors/managers of infection prevention & control departments regarding PICU CLABSI prevention practices, including self-reported compliance with elements of central line bundles. Associations between 2011/12 PICU CLABSI rates and infection prevention practices were examined. Results Reported CLABSI rates decreased during the study period, from 5.8 per 1000 line days in 2006 to 1.4 in 2011/12 (P<0.001). While 73% of PICUs had policies for all central line prevention practices, only 35% of those with policies reported ≥95% compliance. PICUs with ≥95% compliance with central line infection prevention policies had lower reported CLABSI rates, but this association was statistically insignificant. Conclusions There was a non-significant trend in decreasing CLABSI rates as PICUs improved bundle policy compliance. Given that few PICUs reported full compliance with these policies, PICUs increasing their efforts to comply with these policies may help reduce CLABSI rates. PMID:25952048

  9. Immunization Strategies against Piscirickettsia salmonis Infections: Review of Vaccination Approaches and Modalities and Their Associated Immune Response Profiles

    PubMed Central

    Evensen, Øystein

    2016-01-01

    Salmonid rickettsial septicemia (SRS) is a serious, infectious disease in Chilean salmon farming caused by Piscirickettsia salmonis, causing heavy losses to the salmonid industry. P. salmonis belongs to the Gammaproteobacteria, order Thiotrichales. SRS was first described in Chile in 1989, and infection with P. salmonis has since been described from a high number of fish species and in several geographic regions globally. P. salmonis infection of salmonids causes multifocal, necrotic areas of internal organs such as liver, kidney, and spleen. Histologically and immunologically, the tissue response is the formation of granulomas, often with central suppuration. The exact sequence of infection is not known, but bacteria likely gain access to internal organs through mucosal surfaces and when infected, fish carry bacteria in macrophages. It has not been fully determined if the bacterium resides in the cytosol or “hide” within vesicular structures intracellularly, although there are indications that in vitro infection results in actin reorganization and formation of actin-coated vesicle within which the bacterium resides. Protection against lethal challenge is well documented in lab scale experiments, but protection from vaccination has proven more difficult to attain long term under field conditions. Current vaccination protocols include whole cell, inactivated and adjuvanted vaccines for injection for primary immunization followed by oral boost where timing of boost delivery is followed by measuring circulating antibody levels against the pathogen. Documentation also exist that there is correlation between antibody titers and protection against mortality. Future vaccination regimes will likely also include live-attenuated vaccines or other technologies such as DNA vaccination. So far, there is no documentation available for live vaccines and, for DNA vaccines, studies have been unsuccessful under laboratory conditions. PMID:27917172

  10. Infection levels of plerocercoids of the tapeworm Triaenophorus crassus and feeding strategy in two fish species from the ultra-oligotrophic Lake Achensee, Austria.

    PubMed

    Schähle, Z; Medgyesy, N; Psenner, R

    2016-01-01

    Thus far, high burdens of Triaenophorus crassus plerocercoids have been reported only in old age groups of coregonid and salmonid fishes. Here we show heavy infection with T. crassus in young whitefish Coregonus lavaretus in the ultra-oligotrophic and regulated Achensee in Tyrol, Austria. Prevalence of T. crassus on C. lavaretus was 100% in all age groups and abundance significantly increased with fish age. The mean annual accumulation of T. crassus was 5.2 parasites in 0- to 7-year-old C. lavaretus, and 2-year-old specimens already harboured a mean of 19.4 plerocercoids. In Arctic charr Salvelinus umbla, however, the prevalence of T. crassus was less than 16% and the majority of infected fish contained only one or two plerocercoids. Triaenophorus nodulosus was present neither in C. lavaretus nor in S. umbla. We assume that the heavy T. crassus infection in C. lavaretus is largely related to their zooplankton-dominated diet and to the characteristics of Achensee, while habitat choice and feeding strategy of the S. umbla population are seen to be the main reasons for their low burdens of T. crassus.

  11. Epidemiology, Disease Burden, and Treatment Strategies of Chronic Hepatitis C Virus Infections in Saudi Arabia in the New Treatment Paradigm Shift

    PubMed Central

    Aljumah, Abdulrahman A.; Abaalkhail, Faisal; Al-Ashgar, Hamad; Assiri, Abdullah; Babatin, Mohamed; Al Faleh, Faleh; Alghamdi, Abdullah; Al-Hakeem, Raafat; Hashim, Almoataz; Alqutub, Adel; Razavi, Homie; Sanai, Faisal M.; Al-Swat, Khalid; Schmelzer, Jonathan; Altraif, Ibrahim

    2016-01-01

    Background/Aims: Around 101,000 individuals are estimated to be viremic for chronic hepatitis C virus (HCV) in the Kingdom of Saudi Arabia (KSA) in 2014; however, only about 20% have been diagnosed. We aim to assess baseline epidemiology, disease burden, and evaluate strategies to eliminate HCV in KSA. Materials and Methods: The infected population and disease progression were modeled using age- and gender-defined cohorts to track HCV incidence, prevalence, hepatic complications, and mortality. Baseline assumptions and transition probabilities were extracted from the literature. The impacts of two scenarios on HCV-related disease burden were considered through increases in treatment efficacy alone or treatment and diagnosis. Results: In 2030, it is estimated by the base scenario that viremic prevalence will increase to 103,000 cases, hepatocellular carcinoma (HCC) to 470, decompensated and compensated cirrhosis cases to 1,300 and 15,400, respectively, and liver-related mortality to 670 deaths. Using high efficacy treatment alone resulted in 2030 projection of 80,700 viremic cases, 350 HCC cases, 480 liver-related deaths, and 850 and 11,500 decompensated and compensated cirrhosis cases, respectively. With an aggressive treatment strategy, in 2030 there will be about 1,700 viremic cases, 1 HCC case, about 20 liver-related deaths, and 5 and 130 cases of decompensated and compensated cirrhosis, respectively. Delaying this strategy by one year would result in 360 additional deaths by 2030. Conclusions: HCV in KSA remains constant, and cases of advanced liver disease and mortality continue to rise. Considered increases in treatment efficacy and number treated would have a significantly greater impact than increased treatment efficacy alone. The projected impact will facilitate disease forecasting, resource planning, and strategies for HCV management. Increased screening and diagnosis would likely be required as part of a national strategy. PMID:27488321

  12. Diagnostic strategies for invasive fungal infections in patients with hematologic malignancies and hematopoietic stem cell transplant recipients.

    PubMed

    Norkin, Maxim; Wingard, John R

    2013-08-01

    Invasive fungal infections (IFIs) frequently occur and are associated with high morbidity and mortality in patients with hematologic malignancies (HMs) and hematopoietic stem cell transplant (HSCT) recipients. Early diagnosis of IFI in these patients facilitates prompt institution of therapy and leads to improved clinical outcomes. This article reviews widely used methodologies for diagnosing IFIs in patients with HM and HSCT recipients. Advantages and limitations of radiologic studies; microbiologic and histopathologic techniques; fungal biomarker assays, including those for galactomannan antigen and β-(1-3)-D-glucan; and molecular assays that are available to establish an early diagnosis of clinically relevant invasive fungal infections are discussed. Recommendations are provided regarding effective use of these methodologies in clinical practice.

  13. Paediatric Dengue Fever diagnosed through parents' epidemiologic report and preventive strategy during the acute phase of infection.

    PubMed

    Poddighe, Dimitri; Bonomelli, Irene; Giardinetti, Silvia; Nedbal, Marco; Bruni, Paola

    2016-01-01

    In Europe, Dengue Fever is one of the most frequent imported diseases and also autochthonous cases occurred in areas where the insect vector is present. Here, we describe a child returning from Philippines and diagnosed with Dengue Fever, through the information provided by parents about an ongoing outbreak in their municipality. An appropriate clinical management in the hospital was established to monitor the occurrence of complications and to cancel the risk of dengue virus transmission in the acute phase of infection.

  14. Successful implementation of infection control strategies prevents P. aeruginosa transmission among cystic fibrosis patients inside the hospital

    PubMed Central

    Matt, Benedikt; Mitteregger, Dieter; Renner, Sabine; Presterl, Elisabeth; Assadian, Ojan; Diab-Elschahawi, Magda

    2014-01-01

    Background: The aim of this study was to characterise the epidemiology of P. aeruginosa isolated from cystic fibrosis (CF) patients at the Vienna General Hospital (VGH) by molecular genetic fingerprinting in order to understand transmission ways and to evaluate the established infection control protocols. Methods: The outpatient clinic for CF patients at the VGH cares for children and adolescents up to the age of 18 years. Among an average of 139 patients cared for at the clinic, 41 were tested positive for P. aeruginosa during the study period. Fifty P. aeruginosa isolates, obtained between August 2010 and March 2012 from routine examinations of CF patients, were subject to molecular characterization using the DiversiLab® method. Results: 42 distinguishable molecular-biological patterns were identified, 7 of which were found multiple times. 40 out of 42 genotypes were retrieved from single patients only, while two patterns were present in two patients each. Nine patients presented with two or more phenotypically diverse P. aeruginosa isolates. In five of these cases the retrieved isolates belonged to the same genotype. Conclusion: The broad genetic heterogeneity of P. aeruginosa in the studied patient population suggests that the majority of CF patients cared for at the VGH acquire P. aeruginosa from environmental sources. It may be concluded that implemented infection control guidelines have been successful in preventing nosocomial transmission of P. aeruginosa among CF patients within the VGH and patient-to-patient transmission outside the hospital. Chronic polyclonal infection/colonization was rare in the study population. PMID:25285264

  15. The Contrastive Analysis Hypothesis

    ERIC Educational Resources Information Center

    Wardhaugh, Ronald

    1970-01-01

    Discusses the strong contrastive analysis hypothesis, which claims predictive powers for contrastive analysis, and the weak hypothesis, which claims only that contrastive analysis can help account for observed difficulties in second language learning. The strong hypothesis is found untenable, and difficulties with the weak hypothesis are discussed…

  16. Contrasted survival under field or controlled conditions displays associations between mRNA levels of candidate genes and response to OsHV-1 infection in the Pacific oyster Crassostrea gigas.

    PubMed

    Normand, Julien; Li, Ronghua; Quillien, Virgile; Nicolas, Jean-Louis; Boudry, Pierre; Pernet, Fabrice; Huvet, Arnaud

    2014-06-01

    Pacific oyster Crassostrea gigas suffers from chronic or sporadic mortality outbreaks worldwide, resulting from infectious diseases and/or physiological disorders triggered by environmental factors. Since 2008, ostreid herpesvirus OsHV-1 μVar has been identified as the main agent responsible for mass mortality of juvenile oysters in Europe. Previous studies of genome-wide expression profiling have provided candidate genes that potentially contribute to genetically-based resistance to summer mortality. To assess their value in determining resistance to the juvenile mass mortality that has occurred in France since 2008, we analyzed the expression of 17 candidate genes in an experimental infection by OsHV-1 μVar, and in an in vivo field experiment. Individual quantification of mRNA levels of 10 out of the 17 targeted genes revealed significant variation, of which 7 genes were showed differences between conditions that created significant differences in mortality, and 6 depended on the number of OsHV-1 genome copies individually quantified in mantle tissue. Complex SOD metalloenzymes known to be part of the antioxidant defense strategies may at least partly determine susceptibility or resistance to OsHV-1-associated mortality. Furthermore, inhibitor 2 of NF-κB, termed CgIκB2, exhibited highly significant variation of mRNA levels depending on OsHV-1 load in both experiments, suggesting its implication in the antiviral immune response of C. gigas. Our results suggest that CgIκB2 expression would make a good starting point for further functional research and that it could be used in marker-assisted selection.

  17. Effects of genetic similarity on the life-history strategy of co-infecting trematodes: are parasites capable of intrahost kin recognition?

    PubMed

    Joannes, A; Lagrue, C; Poulin, R; Beltran-Bech, S

    2014-08-01

    For conspecific parasites sharing the same host, kin recognition can be advantageous when the fitness of one individual depends on what another does; yet, evidence of kin recognition among parasites remains limited. Some trematodes, like Coitocaecum parvum, have plastic life cycles including two alternative life-history strategies. The parasite can wait for its intermediate host to be eaten by a fish definitive host, thus completing the classical three-host life cycle, or mature precociously and produce eggs while still inside its intermediate host as a facultative shortcut. Two different amphipod species are used as intermediate hosts by C. parvum, one small and highly mobile and the other larger, sedentary, and burrow dwelling. Amphipods often harbour two or more C. parvum individuals, all capable of using one or the other developmental strategy, thus creating potential conflicts or cooperation opportunities over transmission routes. This model was used to test the kin recognition hypothesis according to which cooperation between two conspecific individuals relies on the individuals' ability to evaluate their degree of genetic similarity. First, data showed that levels of intrahost genetic similarity between co-infecting C. parvum individuals differed between host species. Second, genetic similarity between parasites sharing the same host was strongly linked to their likelihood of adopting identical developmental strategies. Two nonexclusive hypotheses that could explain this pattern are discussed: kin recognition and cooperation between genetically similar parasites and/or matching genotypes involving parasite genotype-host compatibility filters.

  18. Monitoring the control of human papillomavirus (HPV) infection and related diseases in Australia: towards a national HPV surveillance strategy.

    PubMed

    Brotherton, Julia M L; Kaldor, John M; Garland, Suzanne M

    2010-09-01

    This paper describes a possible multifaceted approach to human papillomavirus (HPV) related surveillance in Australia following implementation of a national HPV vaccination program. We describe eight main components: monitoring of vaccine coverage, vaccine safety, type-specific HPV infection surveillance, cervical cytology (Pap screening) coverage and screen detected lesion prevalence, cervical cancer incidence and mortality, genital wart incidence, incidence of recurrent respiratory papillomatosis, and knowledge, attitudes and beliefs about HPV and HPV vaccination. Australia is well placed to monitor the impact of its HPV vaccination program as well as to measure vaccine effectiveness with existing HPV vaccines, cervical screening and cancer registries.

  19. Relationship Dynamics and Sexual Risk Reduction Strategies Among Heterosexual Young Adults: A Qualitative Study of Sexually Transmitted Infection Clinic Attendees at an Urban Chicago Health Center

    PubMed Central

    French, Audrey L.; Hosek, Sybil G.; Kendrick, Sabrina R.; Lemos, Diana; Brothers, Jennifer; Kincaid, Stacey L.; Mehta, Supriya D.

    2015-01-01

    Abstract Few studies have examined risk-reduction alternatives to consistent condom use for HIV prevention among heterosexual young adults. We used qualitative methodology to explore risk reduction strategies and contextual factors influencing attempts to reduce risk in an urban, high morbidity sexually transmitted infection (STI) clinic. Focus groups were conducted October–December 2014 with heterosexually identified men (n = 13) and women (n = 20) aged 18–29 seeking STI screening at an urban clinic. Groups were audio recorded, transcribed verbatim, and analyzed for thematic content using Atlas.ti software. Quantitative information included sociodemographics, HIV/STI testing history, and 6-month sexual behaviors. Among 33 predominantly African-American participants with a median age of 22, risk-reduction strategies included monogamy agreements, selective condom use with casual and high-risk partners, and frequent HIV/STI testing, though testing was commonly used as a post-hoc reassurance after risk exposure. Many men and women used implicit risk assessment strategies due to mistrust or difficulty communicating. Concurrency was common but rarely discussed within partnerships. Despite attempts to reduce risk, monogamy agreements were often poorly adhered to and not openly discussed. Alcohol and substance use frequently interfered with safer sexual decisions. Participants were aware of HIV/STI risk and commonly practiced risk-reduction strategies, but acknowledged faulty assumptions and poor adherence. This work provides insights into risk-reduction approaches that are already used and may be strengthened as part of effective HIV/STI prevention interventions. PMID:26588197

  20. Screening HIV-Infected Patients with Low CD4 Counts for Cryptococcal Antigenemia prior to Initiation of Antiretroviral Therapy: Cost Effectiveness of Alternative Screening Strategies in South Africa

    PubMed Central

    Rockers, Peter C.; Bonawitz, Rachael; Sriruttan, Charlotte; Glencross, Deborah K.; Cassim, Naseem; Coetzee, Lindi M.; Greene, Gregory S.; Chiller, Tom M.; Vallabhaneni, Snigdha; Long, Lawrence; van Rensburg, Craig; Govender, Nelesh P.

    2016-01-01

    Background In 2015 South Africa established a national cryptococcal antigenemia (CrAg) screening policy targeted at HIV-infected patients with CD4+ T-lymphocyte (CD4) counts <100 cells/ μl who are not yet on antiretroviral treatment (ART). Two screening strategies are included in national guidelines: reflex screening, where a CrAg test is performed on remnant blood samples from CD4 testing; and provider-initiated screening, where providers order a CrAg test after a patient returns for CD4 test results. The objective of this study was to compare costs and effectiveness of these two screening strategies. Methods We developed a decision analytic model to compare reflex and provider-initiated screening in terms of programmatic and health outcomes (number screened, number identified for preemptive treatment, lives saved, and discounted years of life saved) and screening and treatment costs (2015 USD). We estimated a base case with prevalence and other parameters based on data collected during CrAg screening pilot projects integrated into routine HIV care in Gauteng, Free State, and Western Cape Provinces. We conducted sensitivity analyses to explore how results change with underlying parameter assumptions. Results In the base case, for each 100,000 CD4 tests, the reflex strategy compared to the provider-initiated strategy has higher screening costs ($37,536 higher) but lower treatment costs ($55,165 lower), so overall costs of screening and treatment are $17,629 less with the reflex strategy. The reflex strategy saves more lives (30 lives, 647 additional years of life saved). Sensitivity analyses suggest that reflex screening dominates provider-initiated screening (lower total costs and more lives saved) or saves additional lives for small additional costs (< $125 per life year) across a wide range of conditions (CrAg prevalence, patient and provider behavior, patient survival without treatment, and effectiveness of preemptive fluconazole treatment). Conclusions In

  1. A heterologous neuraminidase subtype strategy for the differentiation of infected and vaccinated animals (DIVA) for avian influenza virus using an alternative neuraminidase inhibition test.

    PubMed

    Avellaneda, Gloria; Sylte, Matt J; Lee, Chang-Won; Suarez, David L

    2010-03-01

    The option of vaccinating poultry against avian influenza (AI) as a control tool is gaining greater acceptance by governments and the poultry industry worldwide. One disadvantage about vaccination with killed whole-virus vaccines is the resulting inability to use common serologic diagnostic tests for surveillance to identify infected flocks. There has been considerable effort to develop a reliable test for the differentiation of infected from vaccinated animals (DIVA). The heterologous neuraminidase (NA) subtype DIVA approach has been used with some success in the field accompanied by an ad hoc serologic test. The traditional NA inhibition (NI) test can be used for all nine NA subtypes, but it is time consuming, and it is not designed to screen large numbers of samples. In this study, a quantitative NI test using MUN (2'-[4-methylumbelliferyl]-alpha-D-Nacetylneuraminic acid sodium salt hydrate) as an NA substrate was investigated as an alternative to the traditional fetuin-based NI test in a heterologous neuraminidase DIVA strategy. Serum NI activity was determined in chickens administered different vaccines containing different H5 and NA subtypes and challenged with a highly pathogenic avian influenza (HPAI) H5N2 virus. Prior to challenge, the NI DIVA test clearly discriminated between chickens receiving vaccines containing different antigens (e.g., N8 or N9) from control birds that had no NA antibody. Some birds began to seroconvert 1 wk postchallenge, and 100% of the vaccinated birds had significant levels of N2 NI activity. This activity did not interfere with the presence of vaccine-induced NI activity against N8 or N9 subtypes. The level of N2-specific NI activity continued to increase to the last sampling date, 4 wk postchallenge, indicating the potential use for the heterologous NA-based DIVA strategy in the field.

  2. Strategies for handling missing clinical data for automated surgical site infection detection from the electronic health record.

    PubMed

    Hu, Zhen; Melton, Genevieve B; Arsoniadis, Elliot G; Wang, Yan; Kwaan, Mary R; Simon, Gyorgy J

    2017-03-16

    Proper handling of missing data is important for many secondary uses of electronic health record (EHR) data. Data imputation methods can be used to handle missing data, but their use for analyzing EHR data is limited and specific efficacy for postoperative complication detection is unclear. Several data imputation methods were used to develop data models for automated detection of three types (i.e., superficial, deep, and organ space) of surgical site infection (SSI) and overall SSI using American College of Surgeons National Surgical Quality Improvement Project (NSQIP) Registry 30-day SSI occurrence data as a reference standard. Overall, models with missing data imputation almost always outperformed reference models without imputation that included only cases with complete data for detection of SSI overall achieving very good average area under the curve values. Missing data imputation appears to be an effective means for improving postoperative SSI detection using EHR clinical data.

  3. From Pichia anomala killer toxin through killer antibodies to killer peptides for a comprehensive anti-infective strategy.

    PubMed

    Polonelli, Luciano; Magliani, Walter; Ciociola, Tecla; Giovati, Laura; Conti, Stefania

    2011-01-01

    "Antibiobodies", antibodies (Abs) with antibiotic activity, internal image of a Pichia anomala killer toxin (PaKT) characterized by microbicidal activity against microorganisms expressing β-glucans cell-wall receptors (PaKTRs), were produced by idiotypic vaccination with a PaKT-neutralizing monoclonal Ab (PaKT-like Abs) or induced by a protein-conjugated β-glucan. Human natural PaKT-like Abs (PaKTAbs) were found in the vaginal fluid of women infected with KT-sensitive microorganisms. Monoclonal and recombinant PaKT-like Abs, and PaKTAbs proved to be protective against experimental candidiasis, cryptococcosis and aspergillosis. A killer decapeptide (KP), synthesized from the sequence of a recombinant PaKT-like Ab or produced in transgenic plants, showed a microbicidal activity in vitro, neutralized by β-glucans, a therapeutic effect in vivo, against experimental mucosal and systemic mycoses, and a prophylactic role in planta, against phytopathogenic microorganisms, respectively. KP showed fungicidal properties against all the defective mutants of a Saccharomyces cerevisiae library, inclusive of strains recognized to be resistant to conventional antifungal drugs. KP inhibited in vitro, ex vivo and/or in vivo HIV-1 and Influenza A virus replication, owing to down-regulation of CCR5 co-receptors, physical block of the gp120-receptor interaction and reduction in the synthesis of glycoproteins, HA and M1 in particular. KP modulated the expression of costimulatory and MHC molecules on murine dendritic cells, improving their capacity to induce lymphocyte proliferation. KP, proven to be devoid of cytotoxicity on human cells, showed self-assembly-releasing hydrogel-like properties, catalyzed by β 1,3 glucan. PaKT's biotechnological derivatives may represent the prototypes of novel antifungal vaccines and anti-infective drugs characterized by different mechanisms of action.

  4. The Wound Healing and Antibacterial Activity of Five Ethnomedical Calophyllum inophyllum Oils: An Alternative Therapeutic Strategy to Treat Infected Wounds

    PubMed Central

    Léguillier, Teddy; Lecsö-Bornet, Marylin; Lémus, Christelle; Rousseau-Ralliard, Delphine; Lebouvier, Nicolas; Hnawia, Edouard; Nour, Mohammed; Aalbersberg, William; Ghazi, Kamelia; Raharivelomanana, Phila; Rat, Patrice

    2015-01-01

    Background Calophyllum inophyllum L. (Calophyllaceae) is an evergreen tree ethno-medically used along the seashores and islands of the Indian and Pacific Oceans, especially in Polynesia. Oil extracted from the seeds is traditionally used topically to treat a wide range of skin injuries from burn, scar and infected wounds to skin diseases such as dermatosis, urticaria and eczema. However, very few scientific studies reported and quantified the therapeutic properties of Calophyllum inophyllum oil (CIO). In this work, five CIO from Indonesia (CIO1), Tahiti (CIO2, 3), Fiji islands (CIO4) and New Caledonia (CIO5) were studied and their cytotoxic, wound healing, and antibacterial properties were presented in order to provide a scientific support to their traditional use and verify their safety. Methods The safety of the five CIO was ascertained using the Alamar blue assay on human keratinocyte cells. CIO wound healing properties were determined using the scratch test assay on human keratinocyte cells. CIO-stimulated antibacterial innate immune response was evaluated using ELISA by measuring β defensin-2 release in human derivative macrophage cells. CIO antibacterial activity was tested using oilogramme against twenty aerobic Gram- bacteria species, twenty aerobic Gram+ bacteria species, including a multi-drug resistant Staphylococcus aureus strain and two anaerobic Gram+ bacteria species e.g. Propionibacterium acnes and Propionibacterium granulosum. To detect polarity profile of the components responsible of the antibacterial activity, we performed bioautography against a Staphylococcus aureus strain. Results Based on Alamar Blue assay, we showed that CIO can be safely used on keratinocyte cells between 2.7% and 11.2% depending on CIO origin. Concerning the healing activity, all the CIO tested accelerated in vitro wound closure, the healing factor being 1.3 to 2.1 higher compared to control when keratinocytes were incubated after scratch with CIO at 0.1%. Furthermore

  5. Sexual behavior, use of contraceptive methods and risk factors for HPV infections of students living in central Italy: implications for vaccination strategies.

    PubMed

    Boccalini, S; Tiscione, E; Bechini, A; Levi, M; Mencacci, M; Petrucci, F; Bani Assad, G; Santini, M G; Bonanni, P

    2012-03-01

    The most frequent risk factors related to the infection/persistence of HPV in the population are an early start of sexual activity, the number of sexual partners, smoking, and the utilization of some contraceptive methods. In Italy, HPV vaccine is offered free of charge to all 12-year-old female adolescents, with a possible extension to other age groups according to Regional policies. In order to value the suitability of the current HPV vaccination strategies in Italy, an epidemiological study on sexual habits in adolescents and young adults was organized. An anonymous questionnaire on sexual behavior and risk factors for HPV infection was administered to 2300 students aged 13-24 years attending secondary schools and universities in Tuscany during 2008-09. About 12% of the sample declared to be foreign citizen. The results highlight the early start of sexual activity among young students. Particularly, more than half of the interviewed students declared to be already sexually active. The mean and the median age of the first sexual intercourse was 15.4 +/- 1.4 years and 15 years (25th and 75th percentiles = 14-16), respectively. More than 77% of students at age 16 years declared they already had the first sexual intercourse, compared with 0.3% of those <12 years. Generally, females aged 13-16-years, if sexually active, had sexual contacts with a single partner. Most students declared to know common contraceptive methods (male condom and contraceptive pill). However, only half of them declared a regular use of male condom. These data confirm the importance of vaccination against HPV for young females before their sexual debut. In addition, the current multi-cohort strategy of HPV vaccination in Tuscany (free of charge in the age range 12-16 years) allows also to catch up those girls that have not yet had their first sexual experiences before 16 years (21.5% according to our study) but also to those girls already sexually active, who very rarely are already infected

  6. Essential Oil of Cymbopogon nardus (L.) Rendle: A Strategy to Combat Fungal Infections Caused by Candida Species

    PubMed Central

    De Toledo, Luciani Gaspar; Ramos, Matheus Aparecido Dos Santos; Spósito, Larissa; Castilho, Elza Maria; Pavan, Fernando Rogério; Lopes, Érica De Oliveira; Zocolo, Guilherme Julião; Silva, Francisca Aliny Nunes; Soares, Tigressa Helena; dos Santos, André Gonzaga; Bauab, Taís Maria; De Almeida, Margarete Teresa Gottardo

    2016-01-01

    Background: The incidence of fungal infections, especially those caused by Candida yeasts, has increased over the last two decades. However, the indicated therapy for fungal control has limitations. Hence, medicinal plants have emerged as an alternative in the search for new antifungal agents as they present compounds, such as essential oils, with important biological effects. Published data demonstrate important pharmacological properties of the essential oil of Cymbopogon nardus (L.) Rendle; these include anti-tumor, anti-nociceptive, and antibacterial activities, and so an investigation of this compound against pathogenic fungi is interesting. Objective: The aim of this study was to evaluate the chemical composition and biological potential of essential oil (EO) obtained from the leaves of C. nardus focusing on its antifungal profile against Candida species. Methods: The EO was obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS). Testing of the antifungal potential against standard and clinical strains was performed by determining the minimal inhibitory concentration (MIC), time-kill, inhibition of Candida albicans hyphae growth, and inhibition of mature biofilms. Additionally, the cytotoxicity was investigated by the IC50 against HepG-2 (hepatic) and MRC-5 (fibroblast) cell lines. Results: According to the chemical analysis, the main compounds of the EO were the oxygen-containing monoterpenes: citronellal, geranial, geraniol, citronellol, and neral. The results showed important antifungal potential for all strains tested with MIC values ranging from 250 to 1000 μg/mL, except for two clinical isolates of C. tropicalis (MIC > 1000 μg/mL). The time-kill assay showed that the EO inhibited the growth of the yeast and inhibited hyphal formation of C. albicans strains at concentrations ranging from 15.8 to 1000 μg/mL. Inhibition of mature biofilms of strains of C. albicans, C. krusei and C. parapsilosis occurred at a

  7. Papers and Studies in Contrastive Linguistics, Volume Twenty-Two. The Polish-English Contrastive Project.

    ERIC Educational Resources Information Center

    Fisiak, Jacek, Ed.

    1988-01-01

    Fifteen articles are presented in this collection on contrastive linguistics: "On Syntactic Levels--One Tertium Comparison is in Contrastive Linguistics" (L. F. Jakobsen and J. Olsen); "Equivalence in Bilingual Lexicography: From Correspondence Relation to Communicative Strategy" (R. R. K. Hartmann); "How Useful Are Word…

  8. Ultrasound contrast agents

    PubMed Central

    Ignee, Andre; Atkinson, Nathan S. S.; Schuessler, Gudrun; Dietrich, Christoph F.

    2016-01-01

    Endoscopic ultrasound (EUS) plays an important role in imaging of the mediastinum and abdominal organs. Since the introduction of US contrast agents (UCA) for transabdominal US, attempts have been made to apply contrast-enhanced US techniques also to EUS. Since 2003, specific contrast-enhanced imaging was possible using EUS. Important studies have been published regarding contrast-enhanced EUS and the characterization of focal pancreatic lesions, lymph nodes, and subepithelial tumors. In this manuscript, we describe the relevant UCA, their application, and specific image acquisition as well as the principles of image tissue characterization using contrast-enhanced EUS. Safety issues, potential future developments, and EUS-specific issues are reviewed. PMID:27824024

  9. Cost-Effectiveness Analysis of Five Competing Strategies for the Management of Multiple Recurrent Community-Onset Clostridium difficile Infection in France

    PubMed Central

    Galperine, Tatiana; Denies, Fanette; Lannoy, Damien; Lenne, Xavier; Odou, Pascal; Guery, Benoit; Dervaux, Benoit

    2017-01-01

    Background Clostridium difficile infection (CDI) is characterized by high rates of recurrence, resulting in substantial health care costs. The aim of this study was to analyze the cost-effectiveness of treatments for the management of second recurrence of community-onset CDI in France. Methods We developed a decision-analytic simulation model to compare 5 treatments for the management of second recurrence of community-onset CDI: pulsed-tapered vancomycin, fidaxomicin, fecal microbiota transplantation (FMT) via colonoscopy, FMT via duodenal infusion, and FMT via enema. The model outcome was the incremental cost-effectiveness ratio (ICER), expressed as cost per quality-adjusted life year (QALY) among the 5 treatments. ICERs were interpreted using a willingness-to-pay threshold of €32,000/QALY. Uncertainty was evaluated through deterministic and probabilistic sensitivity analyses. Results Three strategies were on the efficiency frontier: pulsed-tapered vancomycin, FMT via enema, and FMT via colonoscopy, in order of increasing effectiveness. FMT via duodenal infusion and fidaxomicin were dominated (i.e. less effective and costlier) by FMT via colonoscopy and FMT via enema. FMT via enema compared with pulsed-tapered vancomycin had an ICER of €18,092/QALY. The ICER for FMT via colonoscopy versus FMT via enema was €73,653/QALY. Probabilistic sensitivity analysis with 10,000 Monte Carlo simulations showed that FMT via enema was the most cost-effective strategy in 58% of simulations and FMT via colonoscopy was favored in 19% at a willingness-to-pay threshold of €32,000/QALY. Conclusions FMT via enema is the most cost-effective initial strategy for the management of second recurrence of community-onset CDI at a willingness-to-pay threshold of €32,000/QALY. PMID:28103289

  10. The alternative sigma factor σ(B) plays a crucial role in adaptive strategies of Clostridium difficile during gut infection.

    PubMed

    Kint, Nicolas; Janoir, Claire; Monot, Marc; Hoys, Sandra; Soutourina, Olga; Dupuy, Bruno; Martin-Verstraete, Isabelle

    2017-02-15

    Clostridium difficile is a major cause of diarrhoea associated with antibiotherapy. Exposed to stresses in the gut, C. difficile can survive by inducing protection, detoxification and repair systems. In several firmicutes, most of these systems are controlled by the general stress response involving σ(B) . In this work, we studied the role of σ(B) in the physiopathology of C. difficile. We showed that the survival of the sigB mutant during the stationary phase was reduced. Using a transcriptome analysis, we showed that σ(B) controls the expression of ∼25% of genes including genes involved in sporulation, metabolism, cell surface biogenesis and the management of stresses. By contrast, σ(B) does not control toxin gene expression. In agreement with the up-regulation of sporulation genes, the sporulation efficiency is higher in the sigB mutant than in the wild-type strain. sigB inactivation also led to increased sensitivity to acidification, cationic antimicrobial peptides, nitric oxide and ROS. In addition, we showed for the first time that σ(B) also plays a crucial role in oxygen tolerance in this strict anaerobe. Finally, we demonstrated that the fitness of colonisation by the sigB mutant is greatly affected in a dixenic mouse model of colonisation when compared to the wild-type strain.

  11. CD4+ and viral load outcomes of antiretroviral therapy switch strategies after virologic failure of combination antiretroviral therapy in perinatally HIV-infected youth in the United States

    PubMed Central

    Fairlie, Lee; Karalius, Brad; Patel, Kunjal; van Dyke, Russell B.; Hazra, Rohan; Hernán, Miguel A.; Siberry, George K.; Seage, George R.; Agwu, Allison; Wiznia, Andrew

    2015-01-01

    Objective: This study compared 12-month CD4+ and viral load outcomes in HIV-infected children and adolescents with virological failure, managed with four treatment switch strategies. Design: This observational study included perinatally HIV-infected (PHIV) children in the Pediatric HIV/AIDS Cohort Study (PHACS) and Pediatric AIDS Clinical Trials (PACTG) Protocol 219C. Methods: Treatment strategies among children with virologic failure were compared: continue failing combination antiretroviral therapy (cART); switch to new cART; switch to drug-sparing regimen; and discontinue all ART. Mean changes in CD4+% and viral load from baseline (time of virologic failure) to 12 months follow-up in each group were evaluated using weighted linear regression models. Results: Virologic failure occurred in 939 out of 2373 (40%) children. At 12 months, children switching to new cART (16%) had a nonsignificant increase in CD4+% from baseline, 0.59 percentage points [95% confidence interval (95% CI) −1.01 to 2.19], not different than those who continued failing cART (71%) (−0.64 percentage points, P = 0.15) or switched to a drug-sparing regimen (5%) (1.40 percentage points, P = 0.64). Children discontinuing all ART (7%) experienced significant CD4+% decline −3.18 percentage points (95% CI −5.25 to −1.11) compared with those initiating new cART (P = 0.04). All treatment strategies except discontinuing ART yielded significant mean decreases in log10VL by 12 months, the new cART group having the largest drop (−1.15 log10VL). Conclusion: In PHIV children with virologic failure, switching to new cART was associated with the best virological response, while stopping all ART resulted in the worst immunologic and virologic outcomes and should be avoided. Drug-sparing regimens and continuing failing regimens may be considered with careful monitoring. PMID:26182197

  12. Rationale, design and organization of the delayed antibiotic prescription (DAP) trial: a randomized controlled trial of the efficacy and safety of delayed antibiotic prescribing strategies in the non-complicated acute respiratory tract infections in general practice

    PubMed Central

    2013-01-01

    Background Respiratory tract infections are an important burden in primary care and it’s known that they are usually self-limited and that antibiotics only alter its course slightly. This together with the alarming increase of bacterial resistance due to increased use of antimicrobials calls for a need to consider strategies to reduce their use. One of these strategies is the delayed prescription of antibiotics. Methods Multicentric, parallel, randomised controlled trial comparing four antibiotic prescribing strategies in acute non-complicated respiratory tract infections. We will include acute pharyngitis, rhinosinusitis, acute bronchitis and acute exacerbation of chronic bronchitis or chronic obstructive pulmonary disease (mild to moderate). The therapeutic strategies compared are: immediate antibiotic treatment, no antibiotic treatment, and two delayed antibiotic prescribing (DAP) strategies with structured advice to use a course of antibiotics in case of worsening of symptoms or not improving (prescription given to patient or prescription left at the reception of the primary care centre 3 days after the first medical visit). Discussion Delayed antibiotic prescription has been widely used in Anglo-Saxon countries, however, in Southern Europe there has been little research about this topic. The DAP trial wil evaluate two different delayed strategies in Spain for the main respiratory infections in primary care. Trial registration This trial is registered with ClinicalTrials.gov, number http://NCT01363531. PMID:23682979

  13. "Basic MR Relaxation Mechanisms & Contrast Agent Design"

    PubMed Central

    De León-Rodríguez, Luis M.; Martins, André F.; Pinho, Marco; Rofsky, Neil; Sherry, A. Dean

    2015-01-01

    The diagnostic capabilities of magnetic resonance imaging (MRI) have undergone continuous and substantial evolution by virtue of hardware and software innovations and the development and implementation of exogenous contrast media. Thirty years since the first MRI contrast agent was approved for clinical use, a reliance on MR contrast media persists largely to improve image quality with higher contrast resolution and to provide additional functional characterization of normal and abnormal tissues. Further development of MR contrast media is an important component in the quest for continued augmentation of diagnostic capabilities. In this review we will detail the many important considerations when pursuing the design and use of MR contrast media. We will offer a perspective on the importance of chemical stability, particularly kinetic stability, and how this influences one's thinking about the safety of metal-ligand based contrast agents. We will discuss the mechanisms involved in magnetic resonance relaxation in the context of probe design strategies. A brief description of currently available contrast agents will be accompanied by an in-depth discussion that highlights promising MRI contrast agents in development for future clinical and research applications. Our intention is to give a diverse audience an improved understanding of the factors involved in developing new types of safe and highly efficient MR contrast agents and, at the same time, provide an appreciation of the insights into physiology and disease that newer types of responsive agents can provide. PMID:25975847

  14. Contrast dispersion imaging for cancer localization.

    PubMed

    Mischi, Massimo; Wijkstra, Hessel

    2014-01-01

    Cancer growth is associated with angiogenic processes in many types of cancer. Several imaging strategies have therefore been developed that target angiogenesis as a marker for cancer localization. To this end, intravascular and extravascular tissue perfusion is typically assessed by dynamic contrast enhanced (DCE) ultrasound (US) and MRI. All the proposed strategies, however, overlook important changes in the microvascular architecture that result from angiogenic processes. To overcome these limitations, we have recently introduced a new imaging strategy that analyzes the intravascular dispersion kinetics of contrast agents spreading through the microvasculature. Contrast dispersion is mainly determined by microvascular multi-path trajectories, reflecting the underlying microvascular architecture. This paper reviews the results obtained for prostate cancer localization by US and MRI dispersion imaging, also presenting the latest new developments and future perspectives.

  15. Cost analysis of two strategies for preventing hepatitis A virus infection in Spanish travellers to developing countries.

    PubMed Central

    Bayas, J. M.; González, A.; Vilella, A.; San-Martín, M.; Bertran, M. J.; Adell, C.

    2001-01-01

    Our objectives were to assess the prevalence of anti-hepatitis A (HAV) antibodies in Spanish travellers to developing countries and to carry out a cost analysis to allow the comparison of two vaccination strategies. Adult subjects were selected from among travellers to developing countries. Information was obtained on age, sex, destination, previous vaccination against HAV and having received immunoglobulin. Blood specimens were obtained for anti-HAV antibody determination. A total of 485 travellers were studied. The prevalence of anti-HAV antibody was 30.5% (95% CI 26-35). Antibody prevalence was inversely correlated with age: 9.8% in 18-25 years of age, rising to 75.4% in those 41-55 years of age. Cost analysis determined that the critical value of prevalence for vaccination with HAV vaccine was 37.5%. It was concluded that the youngest Spanish travellers lack anti-HAV antibodies. Vaccination without screening in those < or = 35 years of age and screening before vaccination for those > 35 years, are the preferred alternatives. PMID:11693513

  16. Recombinant protein truncation strategy for inducing bactericidal antibodies to the macrophage infectivity potentiator protein of Neisseria meningitidis and circumventing potential cross-reactivity with human FK506-binding proteins.

    PubMed

    Bielecka, Magdalena K; Devos, Nathalie; Gilbert, Mélanie; Hung, Miao-Chiu; Weynants, Vincent; Heckels, John E; Christodoulides, Myron

    2015-02-01

    A recombinant macrophage infectivity potentiator (rMIP) protein of Neisseria meningitidis induces significant serum bactericidal antibody production in mice and is a candidate meningococcal vaccine antigen. However, bioinformatics analysis of MIP showed some amino acid sequence similarity to human FK506-binding proteins (FKBPs) in residues 166 to 252 located in the globular domain of the protein. To circumvent the potential concern over generating antibodies that could recognize human proteins, we immunized mice with recombinant truncated type I rMIP proteins that lacked the globular domain and the signal leader peptide (LP) signal sequence (amino acids 1 to 22) and contained the His purification tag at either the N or C terminus (C-term). The immunogenicity of truncated rMIP proteins was compared to that of full (i.e., full-length) rMIP proteins (containing the globular domain) with either an N- or C-terminal His tag and with or without the LP sequence. By comparing the functional murine antibody responses to these various constructs, we determined that C-term His truncated rMIP (-LP) delivered in liposomes induced high levels of antibodies that bound to the surface of wild-type but not Δmip mutant meningococci and showed bactericidal activity against homologous type I MIP (median titers of 128 to 256) and heterologous type II and III (median titers of 256 to 512) strains, thereby providing at least 82% serogroup B strain coverage. In contrast, in constructs lacking the LP, placement of the His tag at the N terminus appeared to abrogate bactericidal activity. The strategy used in this study would obviate any potential concerns regarding the use of MIP antigens for inclusion in bacterial vaccines.

  17. Compressive Phase Contrast Tomography

    SciTech Connect

    Maia, Filipe; MacDowell, Alastair; Marchesini, Stefano; Padmore, Howard A.; Parkinson, Dula Y.; Pien, Jack; Schirotzek, Andre; Yang, Chao

    2010-09-01

    When x-rays penetrate soft matter, their phase changes more rapidly than their amplitude. Interference effects visible with high brightness sources creates higher contrast, edge enhanced images. When the object is piecewise smooth (made of big blocks of a few components), such higher contrast datasets have a sparse solution. We apply basis pursuit solvers to improve SNR, remove ring artifacts, reduce the number of views and radiation dose from phase contrast datasets collected at the Hard X-Ray Micro Tomography Beamline at the Advanced Light Source. We report a GPU code for the most computationally intensive task, the gridding and inverse gridding algorithm (non uniform sampled Fourier transform).

  18. [Contrast-induced nephropathy: An update].

    PubMed

    Spagnoli, V; Azzalini, L; Tadros, V X; Picard, F; Ly, H Q

    2016-04-01

    Contrast-induced nephropathy (CIN) is common in hospitalized patients. Its occurrence is associated with an increased hospitalization stay and cost, morbidity and mortality. Thus, preventives strategies remain a major issue. Patients that are referred for cardiac catheterization are among the most vulnerable to develop CIN due to their comorbidities. Moreover, in some cases, such preventives measures cannot be introduced due to emergent clinical settings. After a summary regarding the properties of iodinated contrast medium, the aim of this work was to review the definition, pathophysiology, diagnosis and preventive strategies related to CIN.

  19. Sequential Treatment of Biofilms with Aztreonam and Tobramycin Is a Novel Strategy for Combating Pseudomonas aeruginosa Chronic Respiratory Infections

    PubMed Central

    Macià, María D.; Rubio, Rosa; Moyà, Bartolomé; Cabot, Gabriel; López-Causapé, Carla; Pérez, José L.; Cantón, Rafael; Oliver, Antonio

    2016-01-01

    Traditional therapeutic strategies to control chronic colonization in cystic fibrosis (CF) patients are based on the use of a single nebulized antibiotic. In this study, we evaluated the therapeutic efficacy and dynamics of antibiotic resistance in Pseudomonas aeruginosa biofilms under sequential therapy with inhaled aztreonam (ATM) and tobramycin (TOB). Laboratory strains PAO1, PAOMS (hypermutable), PAOMA (mucoid), and PAOMSA (mucoid and hypermutable) and two hypermutable CF strains, 146-HSE (Liverpool epidemic strain [LES-1]) and 1089-HSE (ST1089), were used. Biofilms were developed using the flow cell system. Mature biofilms were challenged with peak and 1/10-peak concentrations of ATM (700 mg/liter and 70 mg/liter), TOB (1,000 mg/liter and 100 mg/liter), and their alternations (ATM/TOB/ATM and TOB/ATM/TOB) for 2 (t = 2), 4 (t = 4), and 6 days (t = 6). The numbers of viable cells (CFU) and resistant mutants were determined. Biofilm structural dynamics were monitored by confocal laser scanning microscopy and processed with COMSTAT and IMARIS software programs. TOB monotherapy produced an intense decrease in CFU that was not always correlated with a reduction in biomass and/or a bactericidal effect on biofilms, particularly for the CF strains. The ATM monotherapy bactericidal effect was lower, but effects on biofilm biomass and/or structure, including intense filamentation, were documented. The alternation of TOB and ATM led to an enhancement of the antibiofilm activity against laboratory and CF strains compared to that with the individual regimens, potentiating the bactericidal effect and/or the reduction in biomass, particularly at peak concentrations. Resistant mutants were not documented in any of the regimens at the peak concentrations and only anecdotally at the 1/10-peak concentrations. These results support the clinical evaluation of sequential regimens with inhaled antibiotics in CF, as opposed to the current maintenance treatments with just one

  20. Phase-contrast radiography.

    PubMed

    Gao, D; Pogany, A; Stevenson, A W; Wilkins, S W

    1998-01-01

    For the past 100 years, the paradigm for radiography has been premised on absorption as the sole means of contrast formation and on ray optics as the basis for image interpretation. A new conceptual approach to radiography has been developed that includes phase (ie, refractive) contrast and requires wave optics for proper treatment. This new approach greatly increases the amount of information that can be obtained with radiographic techniques and is particularly well suited to the imaging of soft tissue and of very small features in biologic samples. A key feature of the present technique of phase-contrast radiography is the use of a microfocus x-ray source about an order of magnitude (< or = 20 microm) smaller than that used in conventional radiography. Phase-contrast radiography offers a number of improvements over conventional radiography in a clinical setting, especially in soft-tissue imaging. These improvements include increased contrast resulting in improved visualization of anatomic detail, reduced absorbed dose to the patient, inherent image magnification and high spatial resolution, use of harder x rays, and relative ease of implementation. More technologically advanced detectors are currently being developed and commercialized, which will help fully realize the considerable potential of phase-contrast imaging.

  1. Efficacy and Safety of a Preemptive Antiviral Therapy Strategy Based on Combined Virological and Immunological Monitoring for Active Cytomegalovirus Infection in Allogeneic Stem Cell Transplant Recipients

    PubMed Central

    Navarro, David; Amat, Paula; de la Cámara, Rafael; López, Javier; Vázquez, Lourdes; Serrano, David; Nieto, José; Rovira, Monserrat; Piñana, José Luis; Giménez, Estela; Solano, Carlos

    2016-01-01

    Background. Preemptive antiviral therapy for active cytomegalovirus (CMV) infection in allogeneic stem cell transplant recipients (Allo-SCT) results in overtreatment and a high rate of recurrences. Monitoring of CMV-specific T-cell immunity may help to individualize treatments and minimize these problems. Methods. We conducted a prospective, multicenter, matched comparison-group study to evaluate the efficacy and safety of a novel strategy that consisted of interrupting anti-CMV therapy upon CMV DNAemia clearance and concurrent detection of phosphoprotein 65/immediate-early-1-specific interferon-γ-producing CD8+ T cells at levels of >1 cell/µL (within 30 days after the initiation of therapy). Immunological monitoring was performed on days +7, +14, +21, and +28 after treatment initiation. The primary endpoint was the cumulative incidence of recurrent DNAemia within 2 months after treatment cessation. Secondary endpoints were the length of antiviral treatment courses and the incidence of hematological toxicity. Results. Sixty-one patients were enrolled in the study group. Fifty-six patients were included in the matched-control group. Eleven patients (18%) fulfilled the criteria for antiviral treatment interruption. The cumulative incidence of recurrent CMV DNAemia was significantly lower (P = .02) in these patients than in patients in the comparative groups. Likewise, the length of antiviral treatment courses was significantly shorter in these patients than that in patients in the matched-control group (P = .003). No significant differences in the incidence of hematological toxicity was observed between the comparative groups. Conclusions. Our data support the clinical utility of combining immunological and virological monitoring for the management of CMV infection in a subset of Allo-SCT recipients. PMID:27419179

  2. Routine analysis of induced sputum is not an effective strategy for screening persons infected with human immunodeficiency virus for Mycobacterium tuberculosis or Pneumocystis carinii. Pulmonary Complications of HIV Infection Study Group.

    PubMed

    Kvale, P A; Hansen, N I; Markowitz, N; Rosen, M J; Jordan, M C; Meiselman, L; Glassroth, J; Reichman, L B; Wallace, J M; Stansell, J D

    1994-09-01

    A prospective multicenter cohort study comprising 1,171 individuals who were seropositive for human immunodeficiency virus (HIV) but did not have AIDS at the time of enrollment and 182 HIV-seronegative controls, was studied by means of routine induced-sputum analysis in an attempt to detect occult tuberculosis or Pneumocystis carinii pneumonia. One occult case of tuberculosis was discovered upon the patient's enrollment (at baseline); none were discovered during follow-up. Two additional Mycobacterium tuberculosis isolates were recovered (one at baseline, one during follow-up) from subjects with symptoms or abnormalities evident on chest roentgenograms. Three specimens were false-positive (one for M. tuberculosis, two for P. carinii). Five pathogenic nontuberculous mycobacteria isolates were recovered during follow-up. Nonpathogenic, nontuberculous mycobacteria were recovered from 51 (4.6%) of 1,113 baseline specimens and 56 (3.7%) of 1,518 follow-up specimens, primarily at a center where the water supply was contaminated. We conclude that routine induced-sputum analysis is not an effective strategy for screening HIV-infected asymptomatic subjects for tuberculosis or P. carinii pneumonia before the onset of clinically recognizable disease activity.

  3. Psychophysical contrast calibration

    PubMed Central

    To, Long; Woods, Russell L; Goldstein, Robert B; Peli, Eli

    2013-01-01

    Electronic displays and computer systems offer numerous advantages for clinical vision testing. Laboratory and clinical measurements of various functions and in particular of (letter) contrast sensitivity require accurately calibrated display contrast. In the laboratory this is achieved using expensive light meters. We developed and evaluated a novel method that uses only psychophysical responses of a person with normal vision to calibrate the luminance contrast of displays for experimental and clinical applications. Our method combines psychophysical techniques (1) for detection (and thus elimination or reduction) of display saturating nonlinearities; (2) for luminance (gamma function) estimation and linearization without use of a photometer; and (3) to measure without a photometer the luminance ratios of the display’s three color channels that are used in a bit-stealing procedure to expand the luminance resolution of the display. Using a photometer we verified that the calibration achieved with this procedure is accurate for both LCD and CRT displays enabling testing of letter contrast sensitivity to 0.5%. Our visual calibration procedure enables clinical, internet and home implementation and calibration verification of electronic contrast testing. PMID:23643843

  4. Evaluation of chimeric DNA vaccines consisting of premembrane and envelope genes of Japanese encephalitis and dengue viruses as a strategy for reducing induction of dengue virus infection-enhancing antibody response.

    PubMed

    Sjatha, Fithriyah; Kuwahara, Miwa; Sudiro, T Mirawati; Kameoka, Masanori; Konishi, Eiji

    2014-02-01

    Neutralizing antibodies induced by dengue virus (DENV) infection show viral infection-enhancing activities at sub-neutralizing doses. On the other hand, preimmunity against Japanese encephalitis virus (JEV), a congener of DENV, does not increase the severity of DENV infection. Several studies have demonstrated that neutralizing epitopes in the genus Flavivirus are mainly located in domain III (DIII) of the envelope (E) protein. In this study, chimeric premembrane and envelope (prM-E) gene-based expression plasmids of JEV and DENV1 with DIII substitution of each virus were constructed for use as DNA vaccines and their immunogenicity evaluated. Sera from C3H/He and ICR mice immunized with a chimeric gene containing DENV1 DIII on a JEV prM-E gene backbone showed high neutralizing antibody titers with less DENV infection-enhancing activity. Our results confirm the applicability of this approach as a new dengue vaccine development strategy.

  5. The Strategies of Heterosexuals from Large Metropolitan Areas for Assessing the Risks of Exposure to HIV or Other Sexually Transmitted Infections from Partners Met Online.

    PubMed

    Siegel, Karolynn; Lekas, Helen-Maria; Onaga, Marie; Verni, Rachel; Gunn, Hamish

    2017-03-24

    Heterosexuals' use of the Internet for meeting romantic or sexual partners is rapidly increasing, raising concerns about the Internet's potential to facilitate encounters that place individuals at risk for acquiring HIV or other sexually transmitted infections (STIs). For example, online sharing of personal information and self-revelations can foster virtual intimacy, promoting a false sense of familiarity that might accelerate progression to unprotected sex. Therefore, it is critical to understand how those who meet sexual partners online attempt to assess the possible risk of acquiring HIV or STIs posed by having unprotected sex with a new partner and decide whether to use a condom. To investigate this issue, in-depth interviews were conducted with a diverse sample of heterosexual male and female participants from large metropolitan cities who had had unprotected vaginal or anal sex with at least two partners met online in the past 3 months. With few exceptions, participants relied on faulty strategies and heuristics to estimate these risks; yet, most engaged in unprotected sex at their first meeting or very soon afterward. While some seemed to try to make a genuine effort to arrive at a reliable assessment of the HIV risk posed, most appeared to be looking for a way to justify their desire and intention to have unprotected sex. The findings suggest the need for more HIV and sexual health education targeted at heterosexuals, especially for those who go online to meet partners.

  6. Searching for new strategies against biofilm infections: Colistin-AMP combinations against Pseudomonas aeruginosa and Staphylococcus aureus single- and double-species biofilms

    PubMed Central

    Grzywacz, Daria; Kamysz, Wojciech; Lourenço, Anália; Pereira, Maria Olívia

    2017-01-01

    Antimicrobial research is being pressured to look for more effective therapeutics for the ever-growing antibiotic-resistant infections, and antimicrobial peptides (AMP) and antimicrobial combinations are promising solutions. This work evaluates colistin-AMP combinations against two major pathogens, Pseudomonas aeruginosa and Staphylococcus aureus, encompassing non- and resistant strains. Colistin (CST) combined with the AMP temporin A (TEMP-A), citropin 1.1 (CIT-1.1) and tachyplesin I linear analogue (TP-I-L) was tested against planktonic, single- and double-species biofilm cultures. Overall synergy for planktonic P. aeruginosa and synergy/additiveness for planktonic S. aureus were observed. Biofilm growth prevention was achieved with synergy and additiveness. Pre-established 24 h-old biofilms were harder to eradicate, especially for S. aureus and double-species biofilms; still, some synergy and addictiveness was observed for higher concentrations, including for the biofilms of resistant strains. Different treatment times and growth media did not greatly influence AMP activity. CST revealed low toxicity compared with the other AMP but its combinations were toxic for high concentrations. Overall, combinations reduced effective AMP concentrations, mainly in prevention scenarios. Improvement of effectiveness and toxicity of therapeutic strategies will be further investigated. PMID:28355248

  7. Molecular hydrogen in human breath: a new strategy for selectively diagnosing peptic ulcer disease, non-ulcerous dyspepsia and Helicobacter pylori infection.

    PubMed

    Maity, Abhijit; Pal, Mithun; Maithani, Sanchi; Ghosh, Barnali; Chaudhuri, Sujit; Pradhan, Manik

    2016-07-22

    The gastric pathogen Helicobacter pylori utilizes molecular hydrogen (H2) as a respiratory substrate during colonization in the gastric mucosa. However, the link between molecular H2 and the pathogenesis of peptic-ulcer disease (PUD) and non-ulcerous dyspepsia (NUD) by the enzymatic activity of H. pylori still remains mostly unknown. Here we provide evidence that breath H2 excretion profiles are distinctly altered by the enzymatic activity of H. pylori for individuals with NUD and PUD. We subsequently unravelled the potential molecular mechanisms responsible for the alteration of H2 in exhaled breath in association with peptic ulcers, encompassing both gastric and duodenal ulcers, along with NUD. We also established that carbon-isotopic fractionations in the acid-mediated bacterial environment regulated by bacterial urease activity cannot discriminate the actual disease state i.e. whether it is peptic ulcer or NUD. However, our findings illuminate the unusual molecular H2 in breath that can track the precise evolution of PUD and NUD, even after the eradication of H. pylori infection. This deepens our understanding of the pathophysiology of PUD and NUD, reveals non-invasively the actual disease state in real-time and thus offers a novel and robust new-generation strategy for treating peptic-ulcer disease together with non-ulcer related complications even when the existing (13)C-urea breath test ((13)C-UBT) fails to diagnose.

  8. Exploring the contribution of general self-efficacy to the use of self-care symptom management strategies by people living with HIV infection.

    PubMed

    Corless, Inge B; Wantland, Dean; Kirksey, Kenn M; Nicholas, Patrice K; Human, Sarie; Arudo, John; Rosa, Maria; Cuca, Yvette; Willard, Sue; Hamilton, Mary Jane; Portillo, Carmen; Sefcik, Elizabeth; Robinson, Linda; Bain, Cathy; Moezzi, Shanaz; Maryland, Mary; Huang, Emily; Holzemer, William L

    2012-06-01

    General self-efficacy (GSE), the expectation that one is able to perform a behavior successfully, may differentiate those who are able to successfully utilize self-care symptom management strategies (SCSMS). This subanalysis (n=569) of an international 12 site longitudinal randomized controlled trial (RCT) (n=775), investigated GSE as an important factor determining symptom burden, SCSMS, engagement with the provider, and medication adherence over time, and identified differences in those with high and low GSE ratings concerning these variables. Parametric and nonparametric repeated-measures tests were employed to assess GSE and the perceived effectiveness of SCSMS for anxiety, depression, diarrhea, fatigue, nausea, and neuropathy. Symptom burden, engagement with the provider, and antiretroviral adherence were analyzed with regard to GSE. Our data indicated that there were differences in the perceived symptom burden over time of HIV infected individuals by GSE. Those individuals with higher GSE had fewer symptoms and these symptoms were perceived to be less intense than those experienced by the low GSE group. There were few meaningful differences in the SCSMS used by those with high versus low GSE other than the use of illicit substances in the low GSE group. The low GSE group was also significantly (p= < 0.001) less engaged with their healthcare providers. Given the difference in substance use by perceived GSE, and the importance of engagement with the healthcare provider, more attention to the resolution of the concerns of those with low GSE by healthcare providers is warranted.

  9. Phonation in Tonal Contrasts

    ERIC Educational Resources Information Center

    Kuang, Jianjing

    2013-01-01

    Phonation is used in many tonal languages, but how it should be incorporated into tonal systems is not well understood. The purpose of this dissertation thus is to examine the role of phonation in tonal contrasts, and to investigate how phonation and pitch interact in the tonal space. This dissertation presents close studies of tonal contrasts…

  10. Simultaneous blur contrast

    NASA Astrophysics Data System (ADS)

    Webster, Shernaaz M.; Webster, Michael A.; Taylor, John; Jaikumar, Jaikishan; Verma, Richa

    2001-06-01

    How well-focused an image appears can be strongly influenced by the surroundings context. A blurred surround can cause a central image to appear too sharp, while sharped surrounds can induce blur. We examined some spatial properties and stimulus selectivities of this 'simultaneous blur contrast.' Observers adjusted the focus of a central test image by a 2AFC staircase procedure that varied the slope of the image amplitude spectrum. The test were surrounded by 8 identical images with biased spectra, that were presented concurrently with the test for 0.5 sec on a uniform gray background. Contrast effects were comparable in magnitude for image sizes ranging from 1-deg to 4-deg in visual angle, but were stronger for test that were viwe4 in the periphery rather than fixated directly. Consistent biases were found for different types of grayscale images, including natural images, filtered noise, and simple edges. However, effects were weaker when surrounds and tests were drawn from different images, or differed in contrast-polarity or color, and thus do not depend on blur or on average spatial- frequency content per se. These induction effects may in part reflect a manifestation of selective contrast gain control

  11. Contrasting Views on Censorship.

    ERIC Educational Resources Information Center

    Riel, Arthur R., Jr.

    This paper asserts that public demands for book censorship are but one aspect of a deep public dissatisfaction with the educational establishment, and develops the thesis that the cause of this dissatisfaction is the contrast in world views and religions of those in the educational establishment and the censors. The educational establishment…

  12. Chromatography: concepts and contrasts

    SciTech Connect

    Miller, J.M.

    1988-01-01

    As the author states in the Preface, this text attempts to provide a unified approach to chromatography (hence the title) by way of contrasting similarities and differences between gas chromatography (GC), column liquid chromatography (LC), and thin-layer chromatography (TLC). This book is also said to be pitched at an elementary level, suitable for most newcomers to the field (e.g., advanced undergraduates and beginning graduate students in the academic world, as well as bench-level chemists in industry).

  13. Polychromatic diffraction contrast tomography

    SciTech Connect

    King, A.; Reischig, P.; Adrien, J.; Peetermans, S.; Ludwig, W.

    2014-11-15

    This tutorial review introduces the use of polychromatic radiation for 3D grain mapping using X-ray diffraction contrast tomography. The objective is to produce a 3D map of the grain shapes and orientations within a bulk, millimeter-sized polycrystalline sample. The use of polychromatic radiation enables the standard synchrotron X-ray technique to be applied in a wider range of contexts: 1) Using laboratory X-ray sources allows a much wider application of the diffraction contrast tomography technique. 2) Neutron sources allow large samples, or samples containing high Z elements to be studied. 3) Applied to synchrotron sources, smaller samples may be treated, or faster measurements may be possible. Challenges and particularities in the data acquisition and processing, and the limitations of the different variants, are discussed. - Highlights: • We present a tutorial review of polychromatic diffraction contrast tomography techniques. • The use of polychromatic radiation allows the standard synchrotron DCT technique to be extended to a range of other sources. • The characteristics and limitations of all variants of the techniques are derived, discussed and compared. • Examples using laboratory X-ray and cold neutron radiation are presented. • Suggestions for the future development of these techniques are presented.

  14. Low HIV testing uptake following diagnosis of a sexually transmitted infection in Spain: implications for the implementation of efficient strategies to reduce the undiagnosed HIV epidemic.

    PubMed

    Fernández-Balbuena, Sonia; Hoyos, Juan; Rosales-Statkus, María Elena; Nardone, Anthony; Vallejo, Fernando; Ruiz, Mónica; Sánchez, Romina; Belza, María José; Indave, Blanca Iciar; Gutiérrez, Jorge; Álvarez, Jorge; Sordo, Luis

    2016-01-01

    Sexually transmitted infections (STIs) are recognized as one of the conditions in which HIV testing is most clearly indicated. We analyse whether people diagnosed with an STI are being tested for HIV according to the experience of participants in an outreach rapid testing programme in Spain. Between 2008 and 2010, 6293 individuals underwent rapid testing and completed a self-administered questionnaire. We calculated the percentage of individuals that were diagnosed with an STI in the last 5 years and identified the setting where the last episode occurred. We then determined the percentage not receiving an HIV test after the last STI diagnosis and estimated the associated factors. Overall, 17.3% (N = 959) of participants reported an STI diagnosis in the last 5 years, of which 81.5% occurred in general medical settings. Sixty-one percent reported not undergoing HIV testing after their last STI diagnosis, 2.2% of whom reported they had refused the test. Not receiving an HIV test after the last STI diagnosis was independently associated with not being a man who has sex with men (MSM), having had fewer sexual partners, being diagnosed in general medical settings and having received a diagnosis other than syphilis. An unacceptably large percentage of people diagnosed with STI are not being tested for HIV because healthcare providers frequently fail to offer the test. Offering routine HIV testing at general medical settings, regardless of the type of STI diagnosed and population group, should be a high priority and is probably a more efficient strategy than universal screening in general healthcare settings.

  15. Hygiene Strategies to Prevent Methicillin-Resistant Staphylococcus aureus Skin and Soft Tissue Infections: A Cluster-Randomized Controlled Trial Among High-Risk Military Trainees

    PubMed Central

    Ellis, Michael W.; Schlett, Carey D.; Millar, Eugene V.; Wilkins, Kenneth J.; Crawford, Katrina B.; Morrison-Rodriguez, Stephanie M.; Pacha, Laura A.; Gorwitz, Rachel J.; Lanier, Jeffrey B.; Tribble, David R.

    2014-01-01

    Background. Effective measures are needed to prevent methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections (SSTIs) in high-risk community settings. The study objective was to evaluate the effect of personal hygiene–based strategies on rates of overall SSTI and MRSA SSTI. Methods. We conducted a prospective, field-based, cluster-randomized trial in US Army Infantry trainees from May 2010 through January 2012. There were 3 study groups with incrementally increased education and hygiene-based interventions: standard (S), enhanced standard (ES), and chlorhexidine (CHG). The primary endpoints were incidence of overall SSTI and MRSA SSTI. Results. The study included 30 209 trainees constituting 540 platoons (168 S, 192 ES, and 180 CHG). A total of 1203 (4%) participants developed SSTI, 316 (26%) due to MRSA. The overall SSTI rate was 4.15 (95% confidence interval [CI], 3.77–4.58) per 100 person-cycles. SSTI rates by study group were 3.48 (95% CI, 2.87–4.22) for S, 4.18 (95% CI, 3.56–4.90) for ES, and 4.71 (95% CI, 4.03–5.50) for CHG. The MRSA SSTI rate per 100 person-cycles for all groups was 1.10 (95% CI, .91–1.32). MRSA SSTI rates by study group were 1.0 (95% CI, .70–1.42) for S, 1.29 (95% CI, .98–1.71) for ES, and 0.97 (95% CI, .70–1.36) for CHG. Conclusions. Personal hygiene and education measures, including once-weekly use of chlorhexidine body wash, did not prevent overall SSTI or MRSA SSTI in a high-risk population of military trainees. Clinical Trials Registration. NCT01105767. PMID:24633684

  16. Anisotropic contrast optical microscope.

    PubMed

    Peev, D; Hofmann, T; Kananizadeh, N; Beeram, S; Rodriguez, E; Wimer, S; Rodenhausen, K B; Herzinger, C M; Kasputis, T; Pfaunmiller, E; Nguyen, A; Korlacki, R; Pannier, A; Li, Y; Schubert, E; Hage, D; Schubert, M

    2016-11-01

    An optical microscope is described that reveals contrast in the Mueller matrix images of a thin, transparent, or semi-transparent specimen located within an anisotropic object plane (anisotropic filter). The specimen changes the anisotropy of the filter and thereby produces contrast within the Mueller matrix images. Here we use an anisotropic filter composed of a semi-transparent, nanostructured thin film with sub-wavelength thickness placed within the object plane. The sample is illuminated as in common optical microscopy but the light is modulated in its polarization using combinations of linear polarizers and phase plate (compensator) to control and analyze the state of polarization. Direct generalized ellipsometry data analysis approaches permit extraction of fundamental Mueller matrix object plane images dispensing with the need of Fourier expansion methods. Generalized ellipsometry model approaches are used for quantitative image analyses. These images are obtained from sets of multiple images obtained under various polarizer, analyzer, and compensator settings. Up to 16 independent Mueller matrix images can be obtained, while our current setup is limited to 11 images normalized by the unpolarized intensity. We demonstrate the anisotropic contrast optical microscope by measuring lithographically defined micro-patterned anisotropic filters, and we quantify the adsorption of an organic self-assembled monolayer film onto the anisotropic filter. Comparison with an isotropic glass slide demonstrates the image enhancement obtained by our method over microscopy without the use of an anisotropic filter. In our current instrument, we estimate the limit of detection for organic volumetric mass within the object plane of ≈49 fg within ≈7 × 7 μm(2) object surface area. Compared to a quartz crystal microbalance with dissipation instrumentation, where contemporary limits require a total load of ≈500 pg for detection, the instrumentation demonstrated here improves

  17. Anisotropic contrast optical microscope

    NASA Astrophysics Data System (ADS)

    Peev, D.; Hofmann, T.; Kananizadeh, N.; Beeram, S.; Rodriguez, E.; Wimer, S.; Rodenhausen, K. B.; Herzinger, C. M.; Kasputis, T.; Pfaunmiller, E.; Nguyen, A.; Korlacki, R.; Pannier, A.; Li, Y.; Schubert, E.; Hage, D.; Schubert, M.

    2016-11-01

    An optical microscope is described that reveals contrast in the Mueller matrix images of a thin, transparent, or semi-transparent specimen located within an anisotropic object plane (anisotropic filter). The specimen changes the anisotropy of the filter and thereby produces contrast within the Mueller matrix images. Here we use an anisotropic filter composed of a semi-transparent, nanostructured thin film with sub-wavelength thickness placed within the object plane. The sample is illuminated as in common optical microscopy but the light is modulated in its polarization using combinations of linear polarizers and phase plate (compensator) to control and analyze the state of polarization. Direct generalized ellipsometry data analysis approaches permit extraction of fundamental Mueller matrix object plane images dispensing with the need of Fourier expansion methods. Generalized ellipsometry model approaches are used for quantitative image analyses. These images are obtained from sets of multiple images obtained under various polarizer, analyzer, and compensator settings. Up to 16 independent Mueller matrix images can be obtained, while our current setup is limited to 11 images normalized by the unpolarized intensity. We demonstrate the anisotropic contrast optical microscope by measuring lithographically defined micro-patterned anisotropic filters, and we quantify the adsorption of an organic self-assembled monolayer film onto the anisotropic filter. Comparison with an isotropic glass slide demonstrates the image enhancement obtained by our method over microscopy without the use of an anisotropic filter. In our current instrument, we estimate the limit of detection for organic volumetric mass within the object plane of ≈49 fg within ≈7 × 7 μm2 object surface area. Compared to a quartz crystal microbalance with dissipation instrumentation, where contemporary limits require a total load of ≈500 pg for detection, the instrumentation demonstrated here improves

  18. Contrast adaptation in the Limulus lateral eye

    PubMed Central

    Valtcheva, Tchoudomira M.

    2015-01-01

    Luminance and contrast adaptation are neuronal mechanisms employed by the visual system to adjust our sensitivity to light. They are mediated by an assortment of cellular and network processes distributed across the retina and visual cortex. Both have been demonstrated in the eyes of many vertebrates, but only luminance adaptation has been shown in invertebrate eyes to date. Since the computational benefits of contrast adaptation should apply to all visual systems, we investigated whether this mechanism operates in horseshoe crab eyes, one of the best-understood neural networks in the animal kingdom. The spike trains of optic nerve fibers were recorded in response to light stimuli modulated randomly in time and delivered to single ommatidia or the whole eye. We found that the retina adapts to both the mean luminance and contrast of a white-noise stimulus, that luminance- and contrast-adaptive processes are largely independent, and that they originate within an ommatidium. Network interactions are not involved. A published computer model that simulates existing knowledge of the horseshoe crab eye did not show contrast adaptation, suggesting that a heretofore unknown mechanism may underlie the phenomenon. This mechanism does not appear to reside in photoreceptors because white-noise analysis of electroretinogram recordings did not show contrast adaptation. The likely site of origin is therefore the spike discharge mechanism of optic nerve fibers. The finding of contrast adaption in a retinal network as simple as the horseshoe crab eye underscores the broader importance of this image processing strategy to vision. PMID:26445869

  19. [Requirement of standardizing anti-HBs assay methods in Japan for HBV infection-preventing strategy--discrepancy of anti-HBs measurements among three different kits widely used in Japan].

    PubMed

    Ogata, Norio

    2006-09-01

    The strategy to eliminate hepatitis B virus (HBV) infection by administrating an HB vaccine is changing worldwide; however, this is not the case in Japan. An important concern about the HBV infection-preventing strategy in Japan may be that the assay methods for the antibody to hepatitis B surface antigen (anti-HBs) are not standardized. The minimum protective anti-HBs titer against HBV infection has been established as 10 mIU/ml by World Health Organization (WHO) -standardized assay methods worldwide, but that is still determined as a "positive" test result by the passive hemagglutination (PHA) method in Japan. We compared anti-HBs measurements in given samples among PHA(Mycell II, Institute of Immunology), chemiluminescent enzyme immunoassay (CLEIA) (Lumipulse, Fujirebio), and chemiluminescent immunoassay (CLIA) (Architect, Abbott), all of which are currently in wide use in Japan. First, anti-HBs measurements in serum from individuals who received a yeast-derived recombinant HB vaccine composed of the major surface protein of either subtype adr or subtype ayw were compared. The results clearly showed that in subtype adr-vaccinees CLIA underestimated the anti-HBs amount compared with CLEIA and PHA, but in ayw-vaccinees, the discordance in the measurements among the three kits was not prominent. Second, anti-HBs measurements in standard or calibration solutions of each assay kit were compared. Surprisingly, CLEIA showed higher measurements in all three kit-associated standard or calibration solutions than CLIA. Thus, the anti-HBs titer of 10 mIU/ml is difficult to introduce in Japan as the minimum protective level against HBV infection. Efforts to standardize anti-HBs assay methods are expected to share international evidence about the HBV infection-preventing strategy.

  20. Infective endocarditis.

    PubMed

    Cahill, Thomas J; Prendergast, Bernard D

    2016-02-27

    Infective endocarditis occurs worldwide, and is defined by infection of a native or prosthetic heart valve, the endocardial surface, or an indwelling cardiac device. The causes and epidemiology of the disease have evolved in recent decades with a doubling of the average patient age and an increased prevalence in patients with indwelling cardiac devices. The microbiology of the disease has also changed, and staphylococci, most often associated with health-care contact and invasive procedures, have overtaken streptococci as the most common cause of the disease. Although novel diagnostic and therapeutic strategies have emerged, 1 year mortality has not improved and remains at 30%, which is worse than for many cancers. Logistical barriers and an absence of randomised trials hinder clinical management, and longstanding controversies such as use of antibiotic prophylaxis remain unresolved. In this Seminar, we discuss clinical practice, controversies, and strategies needed to target this potentially devastating disease.

  1. High Contrast CRT.

    DTIC Science & Technology

    1980-02-01

    form brown sulfides or sulfates. By con- trast, No. 1720 glass does not acquire a brown coloration . How- ever, preliminary tests with 1723 glass show...TR-77-2639-F NL -mmo mhhmhul IIII,. BwII ---- i 11111--- IIIIIN III i 8’ II.I25 .11111 I .6 MCROCOPY RESOLUTION TEST CHART NATIONAL BUREAU Of...High Contrast Displays Two- Color CRT Laminar Flow Electron Gun Thin Film Phosphor Color Penetration Tube 2% AS~iTACT (ConIlm. a" Pove.. 0fdo if

  2. Contrast and depth perception: effects of texture contrast and area contrast.

    PubMed

    Ichihara, Shigeru; Kitagawa, Norimichi; Akutsu, Hiromi

    2007-01-01

    Many objects in natural scenes have textures on their surfaces. Contrast of the texture surfaces (the texture contrast) reduces when the viewing distance increases. Similarly, contrast between the surfaces of the objects and the background (the area contrast) reduces when the viewing distance increases. The texture contrast and the area contrast were defined by the contrast between random dots, and by the contrast between the average luminance of the dot pattern and the luminance of the background, respectively. To examine how these two types of contrast influence depth perception, we ran two experiments. In both experiments two areas of random-dot patterns were presented against a uniform background, and participants rated relative depth between the two areas. We found that the rated depth of the patterned areas increased with increases in texture contrast. Furthermore, the effect of the texture contrast on depth judgment increased when the area contrast became low.

  3. On Establishing Underlying Tonal Contrast

    ERIC Educational Resources Information Center

    Snider, Keith

    2014-01-01

    Phonological field work is largely about establishing contrast in comparable environments. The notion of phonological contrast, however, can be confusing, particularly in its application to tone analysis. Does it mean phonemic contrast in the structuralist sense, or does it mean underlying contrast in the generative sense? Many linguists, in…

  4. Catheter-Associated Infections

    PubMed Central

    Trautner, Barbara W.; Darouiche, Rabih O.

    2010-01-01

    Intravascular catheters and urinary catheters are the 2 most commonly inserted medical devices in the United States, and they are likewise the two most common causes of nosocomially acquired bloodstream infection. Biofilm formation on the surfaces of indwelling catheters is central to the pathogenesis of infection of both types of catheters. The cornerstone to any preventive strategy of intravascular catheter infections is strict attention to infection control practices. Antimicrobial-impregnated intravascular catheters are a useful adjunction to infection control measures. Prevention of urinary catheter–associated infection is hindered by the numbers and types of organisms present in the periurethral area as well as by the typically longer duration of catheter placement. Antimicrobial agents in general have not been effective in preventing catheter-associated urinary tract infection in persons with long-term, indwelling urethral catheters. Preventive strategies that avoid the use of antimicrobial agents may be necessary in this population. PMID:15111369

  5. Contrasting Martian Terrains

    NASA Technical Reports Server (NTRS)

    2004-01-01

    NASA's Mars Exploration Rover Spirit captured this interesting view of martian topography just below the 'West Spur' portion of the 'Columbia Hills' on sol 208 (Aug. 2, 2004). The view is looking southwest. The rover's wheel tracks show the contrast between soft martian soil and the harder 'Clovis' rock outcrop, which scientists are now studying.

    The angle of the horizon indicates the tilt of the rover to be about 20 degrees. On the horizon is a small peak informally named 'Grissom Hill,' about 15 kilometers (9.3 miles) away. To the right of the peak is the edge of a 2-kilometer-wide (1.2-mile-wide) crater. A few weeks ago, Spirit stopped to conduct scientific studies of rocks in 'Hank's Hollow,' located on the right side of the image approximately one-third of the way down from the top. This photo was taken with Spirit's right rear hazard-avoidance camera.

  6. Contrast statistics for foveated visual systems: fixation selection by minimizing contrast entropy

    NASA Astrophysics Data System (ADS)

    Raj, Raghu; Geisler, Wilson S.; Frazor, Robert A.; Bovik, Alan C.

    2005-10-01

    The human visual system combines a wide field of view with a high-resolution fovea and uses eye, head, and body movements to direct the fovea to potentially relevant locations in the visual scene. This strategy is sensible for a visual system with limited neural resources. However, for this strategy to be effective, the visual system needs sophisticated central mechanisms that efficiently exploit the varying spatial resolution of the retina. To gain insight into some of the design requirements of these central mechanisms, we have analyzed the effects of variable spatial resolution on local contrast in 300 calibrated natural images. Specifically, for each retinal eccentricity (which produces a certain effective level of blur), and for each value of local contrast observed at that eccentricity, we measured the probability distribution of the local contrast in the unblurred image. These conditional probability distributions can be regarded as posterior probability distributions for the ``true'' unblurred contrast, given an observed contrast at a given eccentricity. We find that these conditional probability distributions are adequately described by a few simple formulas. To explore how these statistics might be exploited by central perceptual mechanisms, we consider the task of selecting successive fixation points, where the goal on each fixation is to maximize total contrast information gained about the image (i.e., minimize total contrast uncertainty). We derive an entropy minimization algorithm and find that it performs optimally at reducing total contrast uncertainty and that it also works well at reducing the mean squared error between the original image and the image reconstructed from the multiple fixations. Our results show that measurements of local contrast alone could efficiently drive the scan paths of the eye when the goal is to gain as much information about the spatial structure of a scene as possible.

  7. Economic efficiency analysis of different strategies to control post-weaning multi-systemic wasting syndrome and porcine circovirus type 2 subclinical infection in 3-weekly batch system farms.

    PubMed

    Alarcon, Pablo; Rushton, Jonathan; Nathues, Heiko; Wieland, Barbara

    2013-06-01

    The study assessed the economic efficiency of different strategies for the control of post-weaning multi-systemic wasting syndrome (PMWS) and porcine circovirus type 2 subclinical infection (PCV2SI), which have a major economic impact on the pig farming industry worldwide. The control strategies investigated consisted on the combination of up to 5 different control measures. The control measures considered were: (1) PCV2 vaccination of piglets (vac); (2) ensuring age adjusted diet for growers (diets); (3) reduction of stocking density (stock); (4) improvement of biosecurity measures (bios); and (5) total depopulation and repopulation of the farm for the elimination of other major pathogens (DPRP). A model was developed to simulate 5 years production of a pig farm with a 3-weekly batch system and with 100 sows. A PMWS/PCV2SI disease and economic model, based on PMWS severity scores, was linked to the production model in order to assess disease losses. This PMWS severity scores depends on the combination post-weaning mortality, PMWS morbidity in younger pigs and proportion of PCV2 infected pigs observed on farms. The economic analysis investigated eleven different farm scenarios, depending on the number of risk factors present before the intervention. For each strategy, an investment appraisal assessed the extra costs and benefits of reducing a given PMWS severity score to the average score of a slightly affected farm. The net present value obtained for each strategy was then multiplied by the corresponding probability of success to obtain an expected value. A stochastic simulation was performed to account for uncertainty and variability. For moderately affected farms PCV2 vaccination alone was the most cost-efficient strategy, but for highly affected farms it was either PCV2 vaccination alone or in combination with biosecurity measures, with the marginal profitability between 'vac' and 'vac+bios' being small. Other strategies such as 'diets', 'vac+diets' and 'bios

  8. Effect of Antiviral Prophylaxis Strategy for Chemotherapy-Associated Hepatitis B Reactivation in Non-Hodgkin's Lymphoma Patients with Hepatitis B Virus Infection: A Retrospective Cohort Study.

    PubMed

    Yang, Fan; Zhu, Huan-Ling; He, Chuan; Li, Jian-Jun; Xiang, Bing; Cui, Xu; Huang, Jie; Ji, Jie; Ma, Hong-Bing; Liu, Ting

    2014-06-01

    Recent data indicates that nucleoside/nucleotide analogue (NUC) is effective in preventing and controlling hepatitis B virus (HBV) reactivation in HBV-carrying cancer patients who undergo chemotherapy, but the ideal antiviral agent and optimal application protocol still needs to be determined. Meanwhile, it is uncertain whether those with past HBV infection require antiviral prophylaxis during chemotherapy. This report retrospectively analyzed non-Hodgkin's lymphoma (NHL) patients seen from January, 2004 to June, 2009 in West China Hospital. We found that the prevalence of chronic HBV infection in our NHL patients was 20.7 % while that of past HBV infection was 21.05 %. Compared with the high rate (25.6 %) of HBV reactivation in patients with chronic HBV infection, none of those with past HBV infection in fact had occult HBV infection thus none experienced reactivation. Of the 82 patients with chronic HBV infection who received chemotherapy, antiviral prophylaxis could significantly reduce the incidence of HBV reactivation (5.0 vs. 45.2 % in the control group) and the incidence of liver function damage (32.5 vs. 73.8 % in the control group). The results of the current study confirmed previous reports that prophylactic NUCs administration can effectively prevent HBV reactivation and significantly reduce the incidence of HBV reactivation especially for patients receiving rituximab-containing regimens. Due to the fact that none of individuals who had past HBV infection developed HBV reactivation reported in our study, antiviral prophylaxis may not be required for patients with past HBV infection. Close observation of alanine aminotransferase and HBV-DNA contributes to early diagnosis and timely treatment of HBV reactivation.

  9. Contrast agents for MRI.

    PubMed

    Shokrollahi, H

    2013-12-01

    Contrast agents are divided into two categories. The first one is paramagnetic compounds, including lanthanides like gadolinium, which mainly reduce the longitudinal (T1) relaxation property and result in a brighter signal. The second class consists of super-paramagnetic magnetic nanoparticles (SPMNPs) such as iron oxides, which have a strong effect on the transversal (T2) relaxation properties. SPMNPs have the potential to be utilized as excellent probes for magnetic resonance imaging (MRI). For instance, clinically benign iron oxide and engineered ferrite nanoparticles provide a good MRI probing capability for clinical applications. Furthermore, the limited magnetic property and inability to escape from the reticuloendothelial system (RES) of the used nanoparticles impede their further advancement. Therefore, it is necessary to develop the engineered magnetic nanoparticle probes for the next-generation molecular MRI. Considering the importance of MRI in diagnosing diseases, this paper presents an overview of recent scientific achievements in the development of new synthetic SPMNP probes whereby the sensitive and target-specific observation of biological events at the molecular and cellular levels is feasible.

  10. Phase Contrast Imaging

    SciTech Connect

    Menk, Ralf Hendrik

    2008-11-13

    All standard (medical) x-ray imaging technologies, rely primarily on the amplitude properties of the incident radiation, and do not depend on its phase. This is unchanged since the discovery by Roentgen that the intensity of an x-ray beam, as measured by the exposure on a film, was related to the relative transmission properties of an object. However, recently various imaging techniques have emerged which depend on the phase of the x-rays as well as the amplitude. Phase becomes important when the beam is coherent and the imaging system is sensitive to interference phenomena. Significant new advances have been made in coherent optic theory and techniques, which now promise phase information in medical imaging. The development of perfect crystal optics and the increasing availability of synchrotron radiation facilities have contributed to a significant increase in the application of phase based imaging in materials and life sciences. Unique source characteristics such as high intensity, monochromaticity, coherence and high collimating provide an ideal source for advanced imaging. Phase contrast imaging has been applied in both projection and computed tomography modes, and recent applications have been made in the field of medical imaging. Due to the underlying principle of X-ray detection conventional image receptors register only intensities of wave fields and not their phases. During the last decade basically five different methods were developed that translate the phase information into intensity variations. These methods are based on measuring the phase shift {phi} directly (using interference phenomena), the gradient {nabla}{sub {phi}}, or the Laplacian {nabla}{sup 2}{phi}. All three methods can be applied to polychromatic X-ray sources keeping in mind that the native source is synchrotron radiation, featuring monochromatic and reasonable coherent X-ray beams. Due to the vast difference in the coefficients that are driven absorption and phase effects (factor 1

  11. International population movements and regional Plasmodium falciparum malaria elimination strategies

    PubMed Central

    Tatem, Andrew J.; Smith, David L.

    2010-01-01

    Calls for the eradication of malaria require the development of global and regional strategies based on a strong and consistent evidence base. Evidence from the previous global malaria eradication program and more recent transborder control campaigns have shown the importance of accounting for human movement in introducing infections to areas targeted for elimination. Here, census-based migration data were analyzed with network analysis tools, Plasmodium falciparum malaria transmission maps, and global population databases to map globally communities of countries linked by relatively high levels of infection movements. The likely principal sources and destinations of imported cases in each region were also mapped. Results indicate that certain groups of countries, such as those in West Africa and central Asia are much more strongly connected by relatively high levels of population and infection movement than others. In contrast, countries such as Ethiopia and Myanmar display significantly greater isolation in terms of likely infection movements in and out. The mapping here of both communities of countries linked by likely higher levels of infection movement, and “natural” migration boundaries that display reduced movement of people and infections between regions has practical utility. These maps can inform the design of malaria elimination strategies by identifying regional communities of countries afforded protection from recolonization by surrounding regions of reduced migration. For more isolated countries, a nationally focused control or elimination program is likely to stand a better chance of success than those receiving high levels of visitors and migrants from high-transmission regions. PMID:20566870

  12. Recognition memory reveals just how CONTRASTIVE contrastive accenting really is

    PubMed Central

    Fraundorf, Scott H.; Watson, Duane G.; Benjamin, Aaron S.

    2010-01-01

    The effects of pitch accenting on memory were investigated in three experiments. Participants listened to short recorded discourses that contained contrast sets with two items (e.g. British scientists and French scientists); a continuation specified one item from the set. Pitch accenting on the critical word in the continuation was manipulated between non-contrastive (H* in the ToBI system) and contrastive (L+H*). On subsequent recognition memory tests, the L+H* accent increased hits to correct statements and correct rejections of the contrast item (Experiments 1–3), but did not impair memory for other parts of the discourse (Experiment 2). L+H* also did not facilitate correct rejections of lures not in the contrast set (Experiment 3), indicating that contrastive accents do not simply strengthen the representation of the target item. These results suggest comprehenders use pitch accenting to encode and update information about multiple elements in a contrast set. PMID:20835405

  13. Contrastive Analysis and Language Development.

    ERIC Educational Resources Information Center

    Ferguson, Charles A.

    Contrastive analysis is basic to all linguistics since only by this approach can a general theory of language (language universals) be constructed and only with at least implicit contrastive analysis can a particular language be fully characterized. Two kinds of contrastive analysis have been basic to diachronic linguistics: the comparison of…

  14. Hemodialysis Tunneled Catheter-Related Infections

    PubMed Central

    Miller, Lisa M.; Clark, Edward; Dipchand, Christine; Hiremath, Swapnil; Kappel, Joanne; Kiaii, Mercedeh; Lok, Charmaine; Luscombe, Rick; Moist, Louise; Oliver, Matthew; MacRae, Jennifer

    2016-01-01

    Catheter-related bloodstream infections, exit-site infections, and tunnel infections are common complications related to hemodialysis central venous catheter use. The various definitions of catheter-related infections are reviewed, and various preventive strategies are discussed. Treatment options, for both empiric and definitive infections, including antibiotic locks and systemic antibiotics, are reviewed. PMID:28270921

  15. [Infected pseudarthrosis].

    PubMed

    Kinzl, L; Suger, G

    1996-09-01

    In open fractures the rate of infected non-union defects has in recent years decreased due to the increased primary application of external fixation. In spite of this positive state of affairs the condition is still encountered often enough to warrant specific treatment strategies and techniques. In the treatment of infected pseudarthroses the general principles of osteitis treatment are applied. This includes radical excision of infected pseudarthrotic bone and of the diseased surrounding soft tissue, provides mechanical stability in the non-union area and requires effective local treatment of the infection in combination with systemic, target-specific and temporary well-defined antibiotic therapy as well as procedures to improve local circulation. The incorporation of autogenous bone transplants in defects appears to depend on close contact between the transplant and the vascularized receiving site and on the quantity of the transplanted osseous material. A promising alternative method of dealing with extensive bone defects is osteogenesis produced by callus distraction; therefore special attention is given to Ilizarov's ring fixation system. Unstable scar formation demands local muscular flaps or microvascularized free flap transfer, which seems to be superior to other methods.

  16. Endoscopy imaging intelligent contrast improvement.

    PubMed

    Sheraizin, S; Sheraizin, V

    2005-01-01

    In this paper, we present a medical endoscopy video contrast improvement method that provides intelligent automatic adaptive contrast control. The method fundamentals are video data clustering and video data histogram modification. The video data clustering allows an effective use the low noise two channel contrast enhancement processing. The histogram analysis permitted to determine the video exposure type for simple and complicated contrast distribution. We determined the needed gamma value for automatic local area contrast improvement for the following exposure types: dark, normal, light, dark light, dark normal etc. The experimental results of medical endoscopy video processing allow defining the automatic gamma control range from 0.5 to 2.0.

  17. Central line infections - hospitals

    MedlinePlus

    ... infection; CVC - infection; Central venous device - infection; Infection control - central line infection; Nosocomial infection - central line infection; Hospital acquired infection - central line infection; Patient safety - central ...

  18. Pneumococcal Infections

    MedlinePlus

    ... the bloodstream (bacteremia) Joint infection (arthritis) Ear infection (otitis media) Infection of the sinus membranes (sinusitis) Eye infection ( ... breathing; for bacteremia, fever and less energy; for ear infections, fever and ear pain; and for sinustitis, fever ...

  19. Impact of universal access to hepatitis C therapy on HIV-infected patients: implementation of the Spanish national hepatitis C strategy.

    PubMed

    Rivero-Juarez, A; Lopez-Cortes, L F; Castaño, M; Merino, D; Marquez, M; Mancebo, M; Cuenca-Lopez, F; Jimenez-Aguilar, P; Lopez-Montesinos, I; Lopez-Cardenas, S; Collado, A; Lopez-Ruz, M A; Omar, M; Tellez, F; Perez-Stachowski, X; Hernandez-Quero, J; Girón-Gonzalez, J A; Fernandez-Fuertes, E; Rivero, A

    2017-03-01

    In April 2015, the Spanish National Health System (SNHS) developed a national strategic plan for the diagnosis, treatment, and management of hepatitis C virus (HCV). Our aim was to analyze the impact of this on human immunodeficiency virus (HIV)-infected patients included in the HERACLES cohort during the first 6 months of its implementation. The HERACLES cohort (NCT02511496) was set up in March 2015 to evaluate the status and follow-up of chronic HCV infection in patients co-infected with HIV in the south of Spain. In September 2015, the data were analyzed to identify clinical events (death, liver decompensation, and liver fibrosis progression) and rate of treatment implementation in this population. The study population comprised a total of 3474 HIV/HCV co-infected patients. The distribution according to liver fibrosis stage was: 1152 F0-F1 (33.2 %); 513 F2 (14.4 %); 641 F3 (18.2 %); 761 F4 (21.9 %); and 407 whose liver fibrosis was not measured (12.3 %). During follow-up, 248 patients progressed by at least one fibrosis stage [7.1 %; 95 % confidence interval (CI): 6.3-8 %]. Among cirrhotic patients, 52 (6.8 %; 95 % CI: 5.2-8.9 %) developed hepatic decompensation. In the overall population, 50 patients died (1.4 %; 95 % CI: 1.1-1.9 %). Eight hundred and nineteen patients (23.56 %) initiated interferon (IFN)-free treatment during follow-up, of which 47.8 % were cirrhotic. In our study, during 6 months of follow-up, 23.56 % of HIV/HCV co-infected patients included in our cohort received HCV treatment. However, we observed a high incidence of negative short-term outcomes in our population.

  20. Faithful contrastive features in learning.

    PubMed

    Tesar, Bruce

    2006-09-10

    This article pursues the idea of inferring aspects of phonological underlying forms directly from surface contrasts by looking at optimality theoretic linguistic systems (Prince & Smolensky, 1993/2004). The main result proves that linguistic systems satisfying certain conditions have the faithful contrastive feature property: Whenever 2 distinct morphemes contrast on the surface in a particular environment, at least 1 of the underlying features on which the 2 differ must be realized faithfully on the surface. A learning procedure exploiting the faithful contrastive feature property, contrast analysis, can set the underlying values of some features, even where featural minimal pairs do not exist, but is nevertheless fundamentally limited in what it can set. This work suggests that observation of surface contrasts between pairs of words can contribute to the learning of underlying forms, while still supporting the view that interaction with the phonological mapping will be necessary to fully determine underlying forms.

  1. Polymeric gastrointestinal MR contrast agents.

    PubMed

    Tilcock, C; Unger, E C; Ahkong, Q F; Fritz, T; Koenig, S H; Brown, R D

    1991-01-01

    Combining either paramagnetic (gadolinium chelates) or superparamagnetic (ferrite) contrast agents with polymers such as polyethylene glycol or cellulose, or with simple sugars such as dextrose, results in mixtures that exhibit improved T1 and/or T2 relaxivity compared with that of the contrast agent alone. It is suggested that the addition of such inexpensive and nontoxic polymers or saccharides may improve the effectiveness and decrease the cost of enteric contrast agents.

  2. Geometrical confinement of gadolinium-based contrast agents in nanoporous particles enhances T1 contrast

    PubMed Central

    Ananta, Jeyarama S.; Godin, Biana; Sethi, Richa; Moriggi, Loick; Liu, Xuewu; Serda, Rita E.; Krishnamurthy, Ramkumar; Muthupillai, Raja; Bolskar, Robert D.; Helm, Lothar; Ferrari, Mauro; Wilson, Lon J.; Decuzzi, Paolo

    2010-01-01

    Magnetic resonance imaging contrast agents are currently designed by modifying their structural and physiochemical properties in order to improve relaxivity and to enhance image contrast. Here we show a general method for increasing relaxivity by confining contrast agents inside the nanoporous structure of silicon particles. Magnevist, gadofullerenes and gadonanotubes were loaded inside the pores of quasi-hemispherical and discoidal particles. For all combinations of nanoconstructs, a boost in longitudinal proton relaxivity r1 was observed: for Magnevist, r1~14 mM-1s-1/Gd3+ion (~8.15×10+7 mM-1s-1/construct); for gadofullerenes, r1~200 mM-1s-1/Gd3+ion (~7×10+9 mM-1s-1/construct); for gadonanotubes, r1~150 mM-1s-1/Gd3+ion (~2×10+9 mM-1s-1/construct). These relaxivity values are about 4 to 50 times larger than that of clinically-available gadolinium-based agents (~4 mM-1s-1 /Gd3+ion). The enhancement in contrast is attributed to the geometrical confinement of the agents, which influences the paramagnetic behavior of the Gd3+ions. Thus, nanoscale confinement offers a new and general strategy for enhancing the contrast of gadolinium-based contrast agents. PMID:20972435

  3. Phase contrast MR angiography techniques.

    PubMed

    Dumoulin, C L

    1995-08-01

    Phase contrast MR methods encode information from macroscopic motion into the phase of the MR signal. Phase contrast methods can be applied with small and large fields-of-view, can give quantitative measures of velocity, and provide excellent suppression of signals from stationary tissue. Unlike time-of-flight methods, phase contrast methods directly measure flow and thus are not hindered by the artifactual appearance of tissue having short T1. Phase contrast angiograms can be two-dimensional (thin slice or projectile), three-dimensional, and/or time resolved and have applications throughout the body.

  4. Fuzzy-Contextual Contrast Enhancement.

    PubMed

    Parihar, Anil; Verma, Om; Khanna, Chintan

    2017-02-08

    This paper presents contrast enhancement algorithms based on fuzzy contextual information of the images. We introduce fuzzy similarity index and fuzzy contrast factor to capture the neighborhood characteristics of a pixel. A new histogram, using fuzzy contrast factor of each pixel is developed, and termed as the fuzzy dissimilarity histogram (FDH). A cumulative distribution function (CDF) is formed with normalized values of FDH and used as a transfer function to obtain the contrast enhanced image. The algorithm gives good contrast enhancement and preserves the natural characteristic of the image. In order to develop a contextual intensity transfer function, we introduce a fuzzy membership function based on fuzzy similarity index and coefficient of variation of the image. The contextual intensity transfer function is designed using the fuzzy membership function to achieve final contrast enhanced image. The overall algorithm is referred as the fuzzy contextual contrast-enhancement (FCCE) algorithm. The proposed algorithms are compared with conventional and state-of-art contrast enhancement algorithms. The quantitative and visual assessment of the results is performed. The results of quantitative measures are statistically analyzed using t-test. The exhaustive experimentation and analysis show the proposed algorithm efficiently enhances contrast and yields in natural visual quality images.

  5. Nuclear magnetic resonance contrast agents

    DOEpatents

    Smith, P.H.; Brainard, J.R.; Jarvinen, G.D.; Ryan, R.R.

    1997-12-30

    A family of contrast agents for use in magnetic resonance imaging and a method of enhancing the contrast of magnetic resonance images of an object by incorporating a contrast agent of this invention into the object prior to forming the images or during formation of the images. A contrast agent of this invention is a paramagnetic lanthanide hexaazamacrocyclic molecule, where a basic example has the formula LnC{sub 16}H{sub 14}N{sub 6}. Important applications of the invention are in medical diagnosis, treatment, and research, where images of portions of a human body are formed by means of magnetic resonance techniques. 10 figs.

  6. Nuclear magnetic resonance contrast agents

    DOEpatents

    Smith, Paul H.; Brainard, James R.; Jarvinen, Gordon D.; Ryan, Robert R.

    1997-01-01

    A family of contrast agents for use in magnetic resonance imaging and a method of enhancing the contrast of magnetic resonance images of an object by incorporating a contrast agent of this invention into the object prior to forming the images or during formation of the images. A contrast agent of this invention is a paramagnetic lanthanide hexaazamacrocyclic molecule, where a basic example has the formula LnC.sub.16 H.sub.14 N.sub.6. Important applications of the invention are in medical diagnosis, treatment, and research, where images of portions of a human body are formed by means of magnetic resonance techniques.

  7. Viral infections and allergies.

    PubMed

    Xepapadaki, Paraskevi; Papadopoulos, Nikolaos G

    2007-01-01

    Respiratory viral infections have been implicated in the origin of, protection from and exacerbation of allergy-related symptoms in a variety of ways. Viral infections are closely linked to infantile wheezing. Severe bronchiolitis in early infancy may predispose to chronic childhood asthma as well as allergic sensitization; alternatively it could represent a marker of susceptible individuals. In contrast, repeated mild infections in early life may have a protective role in the development of asthma or atopy by driving the immune system towards Th1 responses. However, evidence on this hypothesis is not consistent as far as respiratory viruses are concerned. Several factors, including the presence of an atopic environment, timing of exposure and severity of the infection, interactively contribute to the allergy-infection relationship. In the present report, recent data on the role of viral infections in the development and progression of allergy and asthma are reviewed.

  8. Chimeric Bivalent Virus-Like Particle Vaccine for H5N1 HPAI and ND Confers Protection against a Lethal Challenge in Chickens and Allows a Strategy of Differentiating Infected from Vaccinated Animals (DIVA)

    PubMed Central

    Noh, Jin-Yong; Park, Jae-Keun; Lee, Dong-Hun; Yuk, Seong-Su; Kwon, Jung-Hoon; Lee, Sang-Won; Lee, Joong-Bok; Park, Seung-Yong; Choi, In-Soo; Song, Chang-Seon

    2016-01-01

    Highly pathogenic avian influenza (HPAI) and Newcastle disease (ND) are considered as the most devastating poultry infections, owing to their worldwide distribution and economical threat. Vaccines have been widely used to control these diseases in the poultry industry in endemic countries. However, vaccination policy without differentiating infected animals from vaccinated animals (DIVA) makes the virus surveillance difficult. In this study, we developed a bivalent virus-like particle (VLP) vaccine that is composed of the hemagglutinin (HA) and matrix 1 (M1) proteins of the H5N1 HPAI virus (HPAIV) and a chimeric protein containing the ectodomain of the ND virus (NDV) fusion (F) protein fused with the cytoplasmic and transmembrane domains of the HPAIV HA protein. A single immunization of chickens with the chimeric VLP vaccine induced high levels of hemagglutination inhibition (HI) antibody titers against H5N1 HPAI virus and anti-NDV antibody detected in ELISA and protected chickens against subsequent lethal HPAIV and NDV infections. Furthermore, we could easily perform DIVA test using the commercial NP-cELISA tests against HPAIV and HI assay against NDV. These results strongly suggest that utilization of chimeric VLP vaccine in poultry species would be a promising strategy for the better control of HPAI and ND simultaneously. PMID:27626934

  9. Chimeric Bivalent Virus-Like Particle Vaccine for H5N1 HPAI and ND Confers Protection against a Lethal Challenge in Chickens and Allows a Strategy of Differentiating Infected from Vaccinated Animals (DIVA).

    PubMed

    Noh, Jin-Yong; Park, Jae-Keun; Lee, Dong-Hun; Yuk, Seong-Su; Kwon, Jung-Hoon; Lee, Sang-Won; Lee, Joong-Bok; Park, Seung-Yong; Choi, In-Soo; Song, Chang-Seon

    2016-01-01

    Highly pathogenic avian influenza (HPAI) and Newcastle disease (ND) are considered as the most devastating poultry infections, owing to their worldwide distribution and economical threat. Vaccines have been widely used to control these diseases in the poultry industry in endemic countries. However, vaccination policy without differentiating infected animals from vaccinated animals (DIVA) makes the virus surveillance difficult. In this study, we developed a bivalent virus-like particle (VLP) vaccine that is composed of the hemagglutinin (HA) and matrix 1 (M1) proteins of the H5N1 HPAI virus (HPAIV) and a chimeric protein containing the ectodomain of the ND virus (NDV) fusion (F) protein fused with the cytoplasmic and transmembrane domains of the HPAIV HA protein. A single immunization of chickens with the chimeric VLP vaccine induced high levels of hemagglutination inhibition (HI) antibody titers against H5N1 HPAI virus and anti-NDV antibody detected in ELISA and protected chickens against subsequent lethal HPAIV and NDV infections. Furthermore, we could easily perform DIVA test using the commercial NP-cELISA tests against HPAIV and HI assay against NDV. These results strongly suggest that utilization of chimeric VLP vaccine in poultry species would be a promising strategy for the better control of HPAI and ND simultaneously.

  10. What makes a cell face selective? The importance of contrast.

    PubMed

    Ohayon, Shay; Freiwald, Winrich A; Tsao, Doris Y

    2012-05-10

    Faces are robustly detected by computer vision algorithms that search for characteristic coarse contrast features. Here, we investigated whether face-selective cells in the primate brain exploit contrast features as well. We recorded from face-selective neurons in macaque inferotemporal cortex, while presenting a face-like collage of regions whose luminances were changed randomly. Modulating contrast combinations between regions induced activity changes ranging from no response to a response greater than that to a real face in 50% of cells. The critical stimulus factor determining response magnitude was contrast polarity, for example, nose region brighter than left eye. Contrast polarity preferences were consistent across cells, suggesting a common computational strategy across the population, and matched features used by computer vision algorithms for face detection. Furthermore, most cells were tuned both for contrast polarity and for the geometry of facial features, suggesting cells encode information useful both for detection and recognition.

  11. A Novel Strategy for TNF-Alpha Production by 2-APB Induced Downregulated SOCE and Upregulated HSP70 in O. tsutsugamushi-Infected Human Macrophages

    PubMed Central

    Liang, Jui-Lin; Tsai, Ming-Hsien; Yen, Chia-Jung; Li, Hsiu-Wen; Chiu, Siou-Jin; Chang, Chung-Hsing; Huang, Yaw-Bin; Lin, Ming-Wei; Yoshioka, Tohru

    2016-01-01

    Orientia (O.) tsutsugamushi-induced scrub typhus is endemic across many regions of Asia and the Western Pacific, where an estimated 1 million cases occur each year; the majority of patients infected with O. tsutsugamushi end up with a cytokine storm from a severe inflammatory response. Previous reports have indicated that blocking tumor necrosis factor (TNF)-α reduced cell injury from a cytokine storm. Since TNF-α production is known to be associated with intracellular Ca2+ elevation, we examined the effect of store-operated Ca2+ entry (SOCE) inhibitors on TNF-α production in O. tsutsugamushi-infected macrophages. We found that 2-aminoethoxydiphenyl borate (2-APB), but not SKF96365, facilitates the suppression of Ca2+ mobilization via the interruption of Orai1 expression in O. tsutsugamushi-infected macrophages. Due to the decrease of Ca2+ elevation, the expression of TNF-α and its release from macrophages was repressed by 2-APB. In addition, a novel role of 2-APB was found in macrophages that causes the upregulation of heat shock protein 70 (HSP70) expression associated with ERK activation; upregulated TNF-α production in the case of knockdown HSP70 was inhibited with 2-APB treatment. Furthermore, elevated HSP70 formation unexpectedly did not help the cell survival of O. tsutsugamushi-infected macrophages. In conclusion, the parallelism between downregulated Ca2+ mobilization via SOCE and upregulated HSP70 after treatment with 2-APB against TNF-α production was found to efficiently attenuate an O. tsutsugamushi-induced severe inflammatory response. PMID:27472555

  12. A Novel Strategy for TNF-Alpha Production by 2-APB Induced Downregulated SOCE and Upregulated HSP70 in O. tsutsugamushi-Infected Human Macrophages.

    PubMed

    Wu, Ching-Ying; Hsu, Wen-Li; Wang, Chun-Hsiung; Liang, Jui-Lin; Tsai, Ming-Hsien; Yen, Chia-Jung; Li, Hsiu-Wen; Chiu, Siou-Jin; Chang, Chung-Hsing; Huang, Yaw-Bin; Lin, Ming-Wei; Yoshioka, Tohru

    2016-01-01

    Orientia (O.) tsutsugamushi-induced scrub typhus is endemic across many regions of Asia and the Western Pacific, where an estimated 1 million cases occur each year; the majority of patients infected with O. tsutsugamushi end up with a cytokine storm from a severe inflammatory response. Previous reports have indicated that blocking tumor necrosis factor (TNF)-α reduced cell injury from a cytokine storm. Since TNF-α production is known to be associated with intracellular Ca2+ elevation, we examined the effect of store-operated Ca2+ entry (SOCE) inhibitors on TNF-α production in O. tsutsugamushi-infected macrophages. We found that 2-aminoethoxydiphenyl borate (2-APB), but not SKF96365, facilitates the suppression of Ca2+ mobilization via the interruption of Orai1 expression in O. tsutsugamushi-infected macrophages. Due to the decrease of Ca2+ elevation, the expression of TNF-α and its release from macrophages was repressed by 2-APB. In addition, a novel role of 2-APB was found in macrophages that causes the upregulation of heat shock protein 70 (HSP70) expression associated with ERK activation; upregulated TNF-α production in the case of knockdown HSP70 was inhibited with 2-APB treatment. Furthermore, elevated HSP70 formation unexpectedly did not help the cell survival of O. tsutsugamushi-infected macrophages. In conclusion, the parallelism between downregulated Ca2+ mobilization via SOCE and upregulated HSP70 after treatment with 2-APB against TNF-α production was found to efficiently attenuate an O. tsutsugamushi-induced severe inflammatory response.

  13. Faithful Contrastive Features in Learning

    ERIC Educational Resources Information Center

    Tesar, Bruce

    2006-01-01

    This article pursues the idea of inferring aspects of phonological underlying forms directly from surface contrasts by looking at optimality theoretic linguistic systems (Prince & Smolensky, 1993/2004). The main result proves that linguistic systems satisfying certain conditions have the faithful contrastive feature property: Whenever 2…

  14. Measurement of visual contrast sensitivity

    NASA Astrophysics Data System (ADS)

    Vongierke, H. E.; Marko, A. R.

    1985-04-01

    This invention involves measurement of the visual contrast sensitivity (modulation transfer) function of a human subject by means of linear or circular spatial frequency pattern on a cathode ray tube whose contrast is automatically decreasing or increasing depending on the subject pressing or releasing a hand-switch button. The threshold of detection of the pattern modulation is found by the subject by adjusting the contrast to values which vary about the subject's threshold thereby determining the threshold and also providing by the magnitude of the contrast fluctuations between reversals some estimate of the variability of the subject's absolute threshold. The invention also involves the slow automatic sweeping of the spatial frequency of the pattern over the spatial frequencies after preset time intervals or after threshold has been defined at each frequency by a selected number of subject-determined threshold crossings; i.e., contrast reversals.

  15. Streptococcal Infections

    MedlinePlus

    ... disease) Group B strep can cause blood infections, pneumonia and meningitis in newborns. A screening test during ... urinary tract infections, blood infections, skin infections and pneumonia in adults. Antibiotics are used to treat strep ...

  16. Kidney Infection

    MedlinePlus

    ... X-ray called a voiding cystourethrogram. Antibiotics for kidney infections Antibiotics are the first line of treatment ... the infection is completely eliminated. Hospitalization for severe kidney infections For a severe kidney infection, your doctor ...

  17. The new numbers contrast sensitivity chart for contrast sensitivity measurement

    PubMed Central

    Khambhiphant, Bharkbhum; Tulvatana, Wasee; Busayarat, Mathu

    2012-01-01

    Purpose To develop and assess the agreement between the 3 newly made numbers contrast sensitivity charts and the MARS contrast sensitivity chart (MARS) in contrast sensitivity measurement. Methods We developed 3 numbers contrast sensitivity charts for right, left and both eyes. Two hundred subjects were assigned to read numbers 0-9 for determining the degree of difficulty. Selected seven numbers were randomly arranged and the contrast of each number was decreased by the constant factor of 0.04 log units in the units as in the MARS. We assigned 112 subjects with visual acuity range from 20/480 to 20/20 to test once with the new chart and then with MARS Chart monocularly and binocularly by random order. Bland-Altman analysis for comparing two charts was performed. Results Bland-Altman analysis between 2 charts showed the mean differences were 0.04, 0.03, 0.04 log CS and the 95% limit of agreement (LOA) of the bias were (+0.26, −0.19), (+0.26, −0.20), (+0.25, −0.17) log CS for right, left and binocular. The Bland-Altman plot indicates a good concordance in 3 charts. Conclusions These charts show reasonable agreement and can be used interchangeably with the MARS. It is helpful for Thai people who can only read numbers in doing the test. We can use them in routinely contrast sensitivity measurement.

  18. Contrasting Rhetorics/Contrasting Cultures: Why Contrastive Rhetoric Needs a Better Conceptualization of Culture

    ERIC Educational Resources Information Center

    Atkinson, Dwight

    2004-01-01

    This paper deals with an underdeveloped notion in the EAP sub-discipline of contrastive rhetoric: culture. It argues that a better conceptualization of contrastive rhetoric needs to include a better conceptualization of culture. After engaging with the complex question "What is culture?" the paper moves on to consider four sets of current issues…

  19. A new anti-infective strategy to reduce the spreading of antibiotic resistance by the action on adhesion-mediated virulence factors in Staphylococcus aureus.

    PubMed

    Papa, Rosanna; Artini, Marco; Cellini, Andrea; Tilotta, Marco; Galano, Eugenio; Pucci, Pietro; Amoresano, Angela; Selan, Laura

    2013-10-01

    Staphylococcus aureus is a flexible microbial pathogen frequently isolated from community-acquired and nosocomial infections. S. aureus expresses a wide array of secreted and cell surface-associated virulence factors, including proteins that promote adhesion to damaged tissue and to the surface of host cells, and that bind proteins in blood to help evade immune responses. Furthermore, surface proteins have a fundamental role in virulence related properties of S. aureus, including biofilm formation. The present study evaluates the anti-infective capabilities of a secreted protein of Serratia marcescens (serratiopeptidase, SPEP), in impairing some staphylococcal virulence-related properties, such as attachment to inert surfaces and adhesion/invasion on eukaryotic cells. SPEP seems to exert its action by modulating specific proteins. It is not assessed if this action is due to the proteolytic activity of SPEP or to a specific mechanism which triggers an out/inside signal. Proteomic studies performed on surface proteins extracted from SPEP treated S. aureus cultures revealed that a number of proteins are affected by the treatment. Among these we found the adhesin/autolysin Atl, SdrD, Sbi, EF-Tu and EF-G. EF-Tu and EF-G are known to perform a variety of function, depending on their cytoplasmic or surface localization. All these factors can facilitate bacterial colonization, persistence and invasion of host tissues. Our results suggest that SPEP could be developed as a potential "anti-infective agent" capable to hinder the entry of S. aureus into human tissues, and also impairs the ability of this pathogen to adhere to prostheses, catheters and medical devices.

  20. The role of appropriate diagnostic testing in acute respiratory tract infections: An antibiotic stewardship strategy to minimise diagnostic uncertainty in primary care.

    PubMed

    Brink, Adrian John; Van Wyk, Johan; Moodley, V M; Corcoran, Craig; Ekermans, Pieter; Nutt, Louise; Boyles, Tom; Perovic, Olga; Feldman, Charles; Richards, Guy; Mendelson, Marc

    2016-05-10

    Antibiotic resistance has increased worldwide to the extent that it is now regarded as a global public health crisis. Interventions to reduce excessive antibiotic prescribing to patients can reduce resistance and improve microbiological and clinical outcomes. Therefore, although improving outpatient antibiotic use is crucial, few data are provided on the key interventional components and the effectiveness of antibiotic stewardship in the primary care setting, in South Africa. The reasons driving the excessive prescription of antibiotics in the community are multifactorial but, perhaps most importantly, the overlapping clinical features of viral and bacterial infections dramatically reduce the ability of GPs to distinguish which patients would benefit from an antibiotic or not. As a consequence, the need for tools to reduce diagnostic uncertainty is critical. In this regard, besides clinical algorithms, a consensus of collaborators in European and UK consortia recently provided guidance for the use of C-reactive protein point-of-care testing in outpatients presenting with acute respiratory tract infections (ARTIs) and/or acute cough, if it is not clear after proper clinical assessment whether antibiotics should be prescribed or not. A targeted application of stewardship principles, including diagnostic stewardship as described in this review, to the ambulatory setting has the potential to affect the most common indications for systemic antibiotic use, in that the majority (80%) of antibiotic use occurs in the community, with ARTIs the most common indication.

  1. Partners at risk: motivations, strategies, and challenges to HIV transmission risk reduction among HIV-infected men and women in Uganda.

    PubMed

    Lifshay, Julie; Nakayiwa, Sylvia; King, Rachel; Reznick, Olga Grinstead; Katuntu, David; Batamwita, Richard; Ezati, Enoch; Coutinho, Alex; Kazibwe, Cissy; Bunnell, Rebecca

    2009-06-01

    Prevention with positives (PWP) is a fundamental component of HIV prevention in industrialized countries. Despite the estimated 22.4 million HIV-infected adults in Africa (UNAIDS, 2006), culturally appropriate PWP guidelines have not been developed for this region. In order to inform these guidelines, we conducted 37 interviews (17 women, 20 men, no couples) from October 2003 to May 2004 with purposefully selected HIV-infected individuals in care in Uganda. Participants reported increased condom use and reduced intercourse frequency and numbers of partners after testing HIV-positive. Motivations for behavior change included concerns for personal health and the health of others, and decreased libido. Gender-power inequities (sometimes manifesting in forced sex), pain experienced by women while using condoms, decreased pleasure for men while using condoms, lack of social support, and desire for children appear to have resulted in increased risk for uninfected partners. Interventions addressing domestic violence, partner negotiation, use of lubricants and alternative sexual activities could increase condom use and/or decrease sexual activity and/or numbers of partners, thereby reducing HIV transmission risk.

  2. The Global Reciprocal Reprogramming between Mycobacteriophage SWU1 and Mycobacterium Reveals the Molecular Strategy of Subversion and Promotion of Phage Infection.

    PubMed

    Fan, Xiangyu; Duan, Xiangke; Tong, Yan; Huang, Qinqin; Zhou, Mingliang; Wang, Huan; Zeng, Lanying; Young, Ry F; Xie, Jianping

    2016-01-01

    Bacteriophages are the viruses of bacteria, which have contributed extensively to our understanding of life and modern biology. The phage-mediated bacterial growth inhibition represents immense untapped source for novel antimicrobials. Insights into the interaction between mycobacteriophage and Mycobacterium host will inform better utilizing of mycobacteriophage. In this study, RNA sequencing technology (RNA-seq) was used to explore the global response of Mycobacterium smegmatis mc(2)155 at an early phase of infection with mycobacteriophage SWU1, key host metabolic processes of M. smegmatis mc(2)155 shut off by SWU1, and the responsible phage proteins. The results of RNA-seq were confirmed by Real-time PCR and functional assay. 1174 genes of M. smegmatis mc(2)155 (16.9% of the entire encoding capacity) were differentially regulated by phage infection. These genes belong to six functional categories: (i) signal transduction, (ii) cell energetics, (iii) cell wall biosynthesis, (iv) DNA, RNA, and protein biosynthesis, (v) iron uptake, (vi) central metabolism. The transcription patterns of phage SWU1 were also characterized. This study provided the first global glimpse of the reciprocal reprogramming between the mycobacteriophage and Mycobacterium host.

  3. The Global Reciprocal Reprogramming between Mycobacteriophage SWU1 and Mycobacterium Reveals the Molecular Strategy of Subversion and Promotion of Phage Infection

    PubMed Central

    Fan, Xiangyu; Duan, Xiangke; Tong, Yan; Huang, Qinqin; Zhou, Mingliang; Wang, Huan; Zeng, Lanying; Young, Ry F.; Xie, Jianping

    2016-01-01

    Bacteriophages are the viruses of bacteria, which have contributed extensively to our understanding of life and modern biology. The phage-mediated bacterial growth inhibition represents immense untapped source for novel antimicrobials. Insights into the interaction between mycobacteriophage and Mycobacterium host will inform better utilizing of mycobacteriophage. In this study, RNA sequencing technology (RNA-seq) was used to explore the global response of Mycobacterium smegmatis mc2155 at an early phase of infection with mycobacteriophage SWU1, key host metabolic processes of M. smegmatis mc2155 shut off by SWU1, and the responsible phage proteins. The results of RNA-seq were confirmed by Real-time PCR and functional assay. 1174 genes of M. smegmatis mc2155 (16.9% of the entire encoding capacity) were differentially regulated by phage infection. These genes belong to six functional categories: (i) signal transduction, (ii) cell energetics, (iii) cell wall biosynthesis, (iv) DNA, RNA, and protein biosynthesis, (v) iron uptake, (vi) central metabolism. The transcription patterns of phage SWU1 were also characterized. This study provided the first global glimpse of the reciprocal reprogramming between the mycobacteriophage and Mycobacterium host. PMID:26858712

  4. Strategies for the empirical management of infection in cancer patients with emphasis on the emergence of resistant gram-negative bacteria.

    PubMed

    Klastersky, Jean; Georgala, Aspasia

    2014-12-01

    Combinations of antibiotics (namely penicillins and aminoglycosides) have been advocated in the 1970s for the empirical therapy of FN in cancer patients in order to take advantage of the possible synergism between these agents and to extend the potential antimicrobial spectrum of empirical therapy. Later, with the development of potent broad spectrum antibiotics, the need for combinations became less obvious as monotherapy with these new agents appeared as effective and less toxic than previously used combinations. However, today we are facing a major challenge through the emergence of multi-resistant microrganisms. With such bacteria, we might be coming back to the pre-antibiotic era when no active agents were available. This situation is due, in part, by the excessive use of antibiotics, namely as a prophylaxis for infection, and is complicated by the fact that very few new effective antibiotics are being developed by the pharmaceutical industry. Under these circumstances, it is likely that we will have to resort to "old timers" such as the polymyxins. It is also possible that combination therapy will come back in favor to take advantage of the synergism and extend the spectrum of coverage, just as it has been the case for the management of resistant tuberculosis. At the same time, the development of multidisciplinary antimicrobial stewardship is mandatory for efficient infection control and minimizing emergence of antimicrobial resistance.

  5. Small intestine contrast injection (image)

    MedlinePlus

    ... and throat, through the stomach into the small intestine. When in place, contrast dye is introduced and ... means of demonstrating whether or not the small intestine is normal when abnormality is suspected.

  6. A theory of behavioral contrast.

    PubMed

    Killeen, Peter R

    2014-11-01

    The reinforcers that maintain target instrumental responses also reinforce other responses that compete with them for expression. This competition, and its imbalance at points of transition between different schedules of reinforcement, causes behavioral contrast. The imbalance is caused by differences in the rates at which different responses come under the control of component stimuli. A model for this theory of behavioral contrast is constructed by expanding the coupling coefficient of MPR (Killeen, 1994). The coupling coefficient gives the degree of association of a reinforcer with the target response (as opposed to other competing responses). Competing responses, often identified as interim or adjunctive or superstitious behavior, are intrinsic to reinforcement schedules, especially interval schedules. In addition to that base-rate of competition, additional competing responses may spill over from the prior component, causing initial contrast; and they may be modulated by conditioned reinforcement or punishment from stimuli associated with subsequent component change, causing terminal contrast. A formalization of these hypotheses employed (a) a hysteresis model of off-target responses giving rise to initial contrast, and (b) a competing traces model of the suppression or enhancement of ongoing competitive responses by signals of following-schedule transition. The theory was applied to transient contrast, the following schedule effect, and the component duration effect.

  7. Liquid crystal precursor mucoadhesive system as a strategy to improve the prophylactic action of Syngonanthus nitens (Bong.) Ruhland against infection by Candida krusei

    PubMed Central

    dos Santos Ramos, Matheus Aparecido; Calixto, Giovana; de Toledo, Luciani Gaspar; Bonifácio, Bruna Vidal; dos Santos, Lourdes Campaner; de Almeida, Margarete Teresa Gottardo; Chorilli, Marlus; Bauab, Taís Maria

    2015-01-01

    Vaginal infections caused by Candida krusei are a problem of extreme complexity due to the intrinsic resistance to azole drugs. The species Syngonanthus nitens (Bong.) Ruhland is a plant of the Eriocaulaceae family that has demonstrated promising antifungal activity. In phyto-formulation research, liquid crystal precursor mucoadhesive systems (LCPM) stand out as drug delivery systems for vaginal administration because they increase the activity and overcome the problems associated with plant-based medicines. Therefore, the objective of this study was to evaluate the potential of the methanolic extract of scapes of S. nitens (S. nitens extract [SNE]) and an SNE-loaded LCPM against C. krusei as prophylaxis for vulvovaginal candidiasis. LCPM formulation developed consisted of oleic acid as the oil phase (50% w/w), polyoxypropylene (5) polyoxyethylene (20) cetyl alcohol (40% w/w) as the surfactant and a polymeric dispersion containing 2.5% Carbopol® 974P and 2.5% polycarbophil (10% w/w) as the aqueous phase. LCPM formulation developed was characterized using polarized light microscopy, rheological analysis, and in vitro mucoadhesive studies. Different strains of C. krusei, including one standard strain (American Type Culture Collection 6258) and three clinically isolated strains from the vaginal region (CKV1, 2, and 3), were used to determine the minimum inhibitory concentration, inhibition of biofilms, and time kill. The in vivo prophylaxis assay was performed using the standard strain (American Type Culture Collection 6258). The analyses of F by polarized light microscopy and rheology showed isotropy; however, the addition of 100% artificial vaginal mucus (F100) made it more viscous and anisotropic. Moreover, the mucoadhesive strength was modified, which makes F an excellent formulation for vaginal applications. SNE was active against all strains studied, with minimum inhibitory concentration values ranging from 125 to 62.5 µg/mL; after incorporating SNE into F (FE

  8. Liquid crystal precursor mucoadhesive system as a strategy to improve the prophylactic action of Syngonanthus nitens (Bong.) Ruhland against infection by Candida krusei.

    PubMed

    dos Santos Ramos, Matheus Aparecido; Calixto, Giovana; de Toledo, Luciani Gaspar; Bonifácio, Bruna Vidal; dos Santos, Lourdes Campaner; de Almeida, Margarete Teresa Gottardo; Chorilli, Marlus; Bauab, Taís Maria

    2015-01-01

    Vaginal infections caused by Candida krusei are a problem of extreme complexity due to the intrinsic resistance to azole drugs. The species Syngonanthus nitens (Bong.) Ruhland is a plant of the Eriocaulaceae family that has demonstrated promising antifungal activity. In phyto-formulation research, liquid crystal precursor mucoadhesive systems (LCPM) stand out as drug delivery systems for vaginal administration because they increase the activity and overcome the problems associated with plant-based medicines. Therefore, the objective of this study was to evaluate the potential of the methanolic extract of scapes of S. nitens (S. nitens extract [SNE]) and an SNE-loaded LCPM against C. krusei as prophylaxis for vulvovaginal candidiasis. LCPM formulation developed consisted of oleic acid as the oil phase (50% w/w), polyoxypropylene (5) polyoxyethylene (20) cetyl alcohol (40% w/w) as the surfactant and a polymeric dispersion containing 2.5% Carbopol(®) 974P and 2.5% polycarbophil (10% w/w) as the aqueous phase. LCPM formulation developed was characterized using polarized light microscopy, rheological analysis, and in vitro mucoadhesive studies. Different strains of C. krusei, including one standard strain (American Type Culture Collection 6258) and three clinically isolated strains from the vaginal region (CKV1, 2, and 3), were used to determine the minimum inhibitory concentration, inhibition of biofilms, and time kill. The in vivo prophylaxis assay was performed using the standard strain (American Type Culture Collection 6258). The analyses of F by polarized light microscopy and rheology showed isotropy; however, the addition of 100% artificial vaginal mucus (F100) made it more viscous and anisotropic. Moreover, the mucoadhesive strength was modified, which makes F an excellent formulation for vaginal applications. SNE was active against all strains studied, with minimum inhibitory concentration values ranging from 125 to 62.5 µg/mL; after incorporating SNE into F

  9. Frequency dependency of temporal contrast adaptation in normal subjects.

    PubMed

    Hohberger, Bettina; Rössler, Christopher W; Jünemann, Anselm G M; Horn, Folkert K; Kremers, Jan

    2011-06-21

    The aim of this study was to determine the influence of temporal frequency of temporal contrast adaptation on contrast sensitivity in healthy subjects. Temporal contrast sensitivities (TCS) were measured monocularly in seven healthy subjects with a modified ERG full-field bowl stimulator at eight different test temporal frequencies (9, 15, 20, 25, 31, 37, 44, 51 Hz) using a two-alternative-forced-choice strategy. Before each presentation of the test stimulus, a 100% contrast adapting flicker stimulus was presented (frequencies: 9, 15, 20, 25, 31, 37, 44, 51, 100 Hz). At each adapting frequency, a complete set of TCSs was measured. All temporal contrast sensitivities decreased with increasing temporal frequencies. Adaptation led to a general temporal contrast sensitivity decrease. Largest adaptation effects were seen at an adaptation frequency of 25 Hz. Reduction of contrast sensitivity was significantly larger at 25 Hz adaptation than at 9 Hz adaptation (t-test of paired samples, Bonferroni corrected). The results of this study showed a general TCS decrease with the largest effect at an adaptation frequency of 25 Hz. This finding indicates that the contrast adaptation probably occurred in the magnocellular-pathway. In future clinical studies adaptation effects could be investigated in patients with reduced temporal contrast sensitivity.

  10. 75 FR 63844 - Healthcare Infection Control Practices Advisory Committee (HICPAC)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-18

    ... HUMAN SERVICES Centers for Disease Control and Prevention Healthcare Infection Control Practices... healthcare infection control and strategies for surveillance, prevention, and control of healthcare... (NICU); draft guideline for Infection Control in Healthcare Personnel; and discussion of ]...

  11. Contrasting coloration in terrestrial mammals

    PubMed Central

    Caro, Tim

    2008-01-01

    Here I survey, collate and synthesize contrasting coloration in 5000 species of terrestrial mammals focusing on black and white pelage. After briefly reviewing alternative functional hypotheses for coloration in mammals, I examine nine colour patterns and combinations on different areas of the body and for each mammalian taxon to try to identify the most likely evolutionary drivers of contrasting coloration. Aposematism and perhaps conspecific signalling are the most consistent explanations for black and white pelage in mammals; background matching may explain white pelage. Evidence for contrasting coloration is being involved in crypsis through pattern blending, disruptive coloration or serving other functions, such as signalling dominance, lures, reducing eye glare or in temperature regulation has barely moved beyond anecdotal stages of investigation. Sexual dichromatism is limited in this taxon and its basis is unclear. Astonishingly, the functional significance of pelage coloration in most large charismatic black and white mammals that were new to science 150 years ago still remains a mystery. PMID:18990666

  12. Multiscale image contrast amplification (MUSICA)

    NASA Astrophysics Data System (ADS)

    Vuylsteke, Pieter; Schoeters, Emile P.

    1994-05-01

    This article presents a novel approach to the problem of detail contrast enhancement, based on multiresolution representation of the original image. The image is decomposed into a weighted sum of smooth, localized, 2D basis functions at multiple scales. Each transform coefficient represents the amount of local detail at some specific scale and at a specific position in the image. Detail contrast is enhanced by non-linear amplification of the transform coefficients. An inverse transform is then applied to the modified coefficients. This yields a uniformly contrast- enhanced image without artefacts. The MUSICA-algorithm is being applied routinely to computed radiography images of chest, skull, spine, shoulder, pelvis, extremities, and abdomen examinations, with excellent acceptance. It is useful for a wide range of applications in the medical, graphical, and industrial area.

  13. Diagnostic tests in HIV management: a review of clinical and laboratory strategies to monitor HIV-infected individuals in developing countries.

    PubMed Central

    Kimmel, April D.; Losina, Elena; Freedberg, Kenneth A.; Goldie, Sue J.

    2006-01-01

    We conducted a systematic review on the performance of diagnostic tests for clinical and laboratory monitoring of HIV-infected adults in developing countries. Diagnostic test information collected from computerized databases, bibliographies and the Internet were categorized as clinical (non-laboratory patient information), immunologic (information from immunologic laboratory tests), or virologic (information from virologic laboratory tests). Of the 51 studies selected for the review 28 assessed immunologic tests, 12 virologic tests and seven clinical and immunologic tests. Methods of performance evaluation were primarily sensitivity and specificity for the clinical category and correlation coefficients for immunologic and virologic categories. In the clinical category, the majority of test performance measures was reported as >70% sensitive and >65% specific. In the immunologic category, correlation coefficients ranged from r=0.54 to r=0.99 for different CD4 count enumeration techniques, while correlation for CD4 and total lymphocyte counts was between r=0.23 and r=0.74. In the virologic category, correlation coefficients for different human immunodeficiency virus (HIV) ribonucleic acid (RNA) quantification techniques ranged from r=0.54 to r=0.90. Future research requires consensus on designing studies, and collecting and reporting data useful for decision-makers. We recommend classifying information into clinically relevant categories, using a consistent definition of disease across studies and providing measures of both association and accuracy. PMID:16878233

  14. Effect of prolonged discontinuation of successful antiretroviral therapy on CD4+ T cell decline in human immunodeficiency virus-infected patients: implications for intermittent therapeutic strategies.

    PubMed

    Tebas, Pablo; Henry, Keith; Mondy, Kristin; Deeks, Steven; Valdez, Herman; Cohen, Cal; Powderly, William G

    2002-09-15

    This study evaluates the change in CD4(+) T cell counts among patients who achieved complete viral suppression and subsequently discontinued highly active antiretroviral therapy (HAART). We included 72 human immunodeficiency virus (HIV)-1-infected patients with plasma HIV RNA loads of <500 copies/mL for at least 3 months who then discontinued therapy for at least 12 weeks. The median CD4(+) T decay while off HAART was 16 cells/mm(3)/month (interquartile range, -6 to -34 cells/month). The mean follow-up after therapy ended was 45 weeks. The slope of the CD4(+) T cell decay was inversely correlated with the increase of CD4(+) T cells while receiving HAART, baseline virus load, CD4(+) T cell count at the time therapy was discontinued, age, and duration HIV RNA levels were undetectable. In a multiple regression analysis model, the increase of CD4(+) T cells while receiving therapy and age were independently associated with the rate of CD4(+) T cell loss.

  15. Occupational Infection in Korea

    PubMed Central

    Ahn, Yeon-Soon; Jeong, Jae Sim

    2010-01-01

    Occupational infection is a human disease caused by work-associated exposure to microbial agents through human and environmental contact. According to the literature, occupational infection was the third leading cause of occupational disease (861 cases, 8.0%), and health care, agricultural, forestry, and fishery workers were risk groups in Korea. In addition, most high-risk groups have not been protected by workers' compensation, which could lead to underestimation of the exact spectrum and magnitude of the problem, and may also result in a lack of development and implementation of occupational infection management. Through a review of national guidelines and documentations on prevention and control of occupational infection, a management strategy would promote adherence to worker safety regulations if it is explicit with regard to the agent and mode of infection in each of the high-risk groups. PMID:21258592

  16. A Contrastive Analysis of the American and Persian Newspaper Editorials

    ERIC Educational Resources Information Center

    Homayounzadeh, Maryam; Mehrpour, Saeed

    2013-01-01

    Based on the principles of critical discourse analysis this contrastive study sought to investigate the effect of culture on the journalistic style and the strategies used to report news in the American and Persian newspaper editorials. To this end, articles were selected from the New York Times, the Washington Post, Kayhan and Ettelaat,…

  17. The Effects of Auditory Contrast Tuning upon Speech Intelligibility

    PubMed Central

    Killian, Nathan J.; Watkins, Paul V.; Davidson, Lisa S.; Barbour, Dennis L.

    2016-01-01

    We have previously identified neurons tuned to spectral contrast of wideband sounds in auditory cortex of awake marmoset monkeys. Because additive noise alters the spectral contrast of speech, contrast-tuned neurons, if present in human auditory cortex, may aid in extracting speech from noise. Given that this cortical function may be underdeveloped in individuals with sensorineural hearing loss, incorporating biologically-inspired algorithms into external signal processing devices could provide speech enhancement benefits to cochlear implantees. In this study we first constructed a computational signal processing algorithm to mimic auditory cortex contrast tuning. We then manipulated the shape of contrast channels and evaluated the intelligibility of reconstructed noisy speech using a metric to predict cochlear implant user perception. Candidate speech enhancement strategies were then tested in cochlear implantees with a hearing-in-noise test. Accentuation of intermediate contrast values or all contrast values improved computed intelligibility. Cochlear implant subjects showed significant improvement in noisy speech intelligibility with a contrast shaping procedure. PMID:27555826

  18. A Bibliography of Contrastive Linguistics.

    ERIC Educational Resources Information Center

    Hammer, John H.; Rice, Frank A.

    This 484-item bibliography is a revised and expanded version of William W. Gage's "Contrastive Studies in Linguistics: A Bibliographical Checklist" (CAL, 1961). Following a general section, the entries are arranged alphabetically by foreign language. The language headings are: Afrikaans, Arabic, Armenian, Azerbaijani, Bantu, Batak, Bengali,…

  19. Simultaneous density contrast is bidirectional.

    PubMed

    Sun, Hua-Chun; Baker, Curtis L; Kingdom, Frederick A A

    2016-11-01

    Simultaneous density contrast, or SDC, is the phenomenon in which the perceived density of a textured region is altered by a surround of different density (Mackay, 1973). SDC provides an experimental tool to investigate mechanisms of density coding, yet has not been systematically examined. We measured SDC with a 2AFC staircase procedure in which human observers judged which of two patterns, one with and one without a surround, appeared more dense. We used a range of surround densities varying from very sparse to very dense (0-76.8 dots/deg2), and two center test densities (6.4 and 12.8 dots/deg2). Psychometric functions were used to estimate both the points of subjective equality (PSE) and their precision. Unexpectedly we find a bidirectional SDC effect across the five observers: Not only does a denser surround reduce perceived density of the cente