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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

    2012-01-01

    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 genomic patterns and infection strategies of two co-existing Bacteroidetes podovirus genera.

    PubMed

    Holmfeldt, Karin; Howard-Varona, Cristina; Solonenko, Natalie; Sullivan, Matthew B

    2014-08-01

    Bacterial viruses (phages) are abundant, ecologically important biological entities. However, our understanding of their impact is limited by model systems that are primarily not well represented in nature, e.g. Enterophages and their hosts. Here, we investigate genomic characteristics and infection strategies among six aquatic Bacteroidetes phages that represent two genera of exceptionally large (∼70-75 kb genome) podoviruses, which were isolated from the same seawater sample using Cellulophaga baltica as host. Quantitative host range studies reveal that these genera have contrasting narrow (specialist) and broad (generalist) host ranges, with one-step growth curves revealing reduced burst sizes for the generalist phages. Genomic comparisons suggest candidate genes in each genus that might explain this host range variation, as well as provide hypotheses about receptors in the hosts. One generalist phage, φ38:1, was more deeply characterized, as its infection strategy switched from lytic on its original host to either inefficient lytic or lysogenic on an alternative host. If lysogenic, this phage was maintained extrachromosomally in the alternative host and could not be induced by mitomycin C. This work provides fundamental knowledge regarding phage-host ranges and their genomic drivers while also exploring the 'host environment' as a driver for switching phage replication mode. PMID:24428166

  3. Contrasting infection strategies in generalist and specialist wasp parasitoids of Drosophila melanogaster.

    PubMed

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

    2007-10-26

    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

  4. Helicobacter and Salmonella Persistent Infection Strategies

    PubMed Central

    Monack, Denise M.

    2013-01-01

    Some host-adapted bacterial pathogens are capable of causing persistent infections in humans. For example, Helicobacter pylori inhabits the human gastric mucosa and persistence can be lifelong. Salmonella enterica serovar Typhi causes systemic infections that involve colonization of the reticuloendothelial system and some individuals become lifelong carriers. In this review, I compare and contrast the different lifestyles of Helicobacter and Salmonella within the host and the strategies they have evolved to persist in mammalian hosts. Persistently infected carriers serve as the reservoirs for these pathogens, and the carrier state is an essential feature that is required for survival of the bacteria within a restricted host population. Therefore, investigating the chronic carrier state should provide insight into bacterial survival strategies, as well as new therapeutic approaches for treatments. PMID:24296347

  5. 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

  6. 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

  7. The Uppsala Contrast Sensitivity Test (UCST): A fast strategy for clinical assessment of contrast sensitivity

    NASA Astrophysics Data System (ADS)

    Malmqvist, Lars D.; Söderberg, Per G.

    2014-02-01

    Routine clinical measurement of spectral contrast sensitivity is hampered by the time consumption of current methods. We are developing a system that allows instantaneous measurement of spectral contrast sensitivity. The UCST system consists of custom software running on an iPad connected to a calibrated TFT-monitor. Twenty healthy subjects were consecutively randomized to have their spectral contrast sensitivity measured with the UCST strategy or with a Vistech VCTS 6500 chart. The examination time and the spectral contrast sensitivity, respectively, were recorded for each eye in each subject. The Vistech strategy resulted in a more extended mean examination time (CI-Vistech:+/- (0.95) = 87 +/-27 s, d.f. = 9) than the UCST strategy (CI-UCST:μ (0.95) = 13 +/-4 s, d.f. = 9), and the estimated mean difference between the two strategies indicated a difference in examination time (CI-difference:μ (0.95) = [47;106] s, d.f. = 18). The overall contrast sensitivity for each group was estimated as the contrast sensitivities for the spatial frequencies sampled, integrated over the spatial frequency band sampled. The Vistech strategy resulted in a higher estimated mean overall contrast sensitivity (CI-Vistech:μ (0.95) = 116+/-24 log rel.·log [c.·deg-1], d.f. = 9) than the UCST strategy (CIUCST: μ (0.95) = 74+/-14 log rel.·log [c.·deg-1], d.f. = 9), and the estimated mean difference between the two strategies indicated a difference in overall contrast sensitivity (CI-difference:μ (0.95) = [15;68] log rel.·log [c.·deg-1]), d.f. = 18). It is concluded that the UCST strategy measures spectral contrast sensitivity on the order of 7 times faster than the Vistech strategy. The slightly lower overall contrast sensitivity recorded for the UCST strategy appeared to be due to a limitation in dynamic range that can be overcome with improved design.

  8. Contrasting effects of immunosuppression on Theiler's virus infection in mice.

    PubMed

    Lipton, H L; Canto, C D

    1977-03-01

    In the present study, cyclophosphamide and rabbit anti-mouse thymocyte serum were used to immunosuppress SJL/J mice infected with Theiler's mouse encephalomyelitis virus (TMEV) in order to delineate the potential mechanism(s) of virus-induced cellular injury in this infection. Whereas both immunosuppressive agents produced a significant increase in mortality, this treatment had differing effects on the pathological involvement of gray and white-matter structures in the central nervous system. The central nervous system of immunosuppressed TMEV-infected mice had increased microglial cell proliferation and neuronal necrosis, longer maintenance of high virus levels and spread of virus antigen to involve the neocortex and hippocampal complex. These observations indicate that TMEV causes a cytolotic infection of neurons and possibly other cells in gray matter. In contrast, immunosuppression produced a dramatic reduction in mononuclear inflammatory cells in the leptomeninges and spinal cord white matter of infected mice and prevented demyelination. Further, virus antigen was not detected in the leptomeninges and white matter of immunosuppressed and infected mice. These findings suggest that demyelination of TMEV infection is immune mediated.

  9. Mosquito Defense Strategies against Viral Infection.

    PubMed

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

    2016-03-01

    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 nonpathogenic 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.

  10. 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. PMID:25383647

  11. 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.

  12. Strategies for combating bacterial biofilm infections

    PubMed Central

    Wu, Hong; Moser, Claus; Wang, Heng-Zhuang; Høiby, Niels; Song, Zhi-Jun

    2015-01-01

    Formation of biofilm is a survival strategy for bacteria and fungi to adapt to their living environment, especially in the hostile environment. Under the protection of biofilm, microbial cells in biofilm become tolerant and resistant to antibiotics and the immune responses, which increases the difficulties for the clinical treatment of biofilm infections. Clinical and laboratory investigations demonstrated a perspicuous correlation between biofilm infection and medical foreign bodies or indwelling devices. Clinical observations and experimental studies indicated clearly that antibiotic treatment alone is in most cases insufficient to eradicate biofilm infections. Therefore, to effectively treat biofilm infections with currently available antibiotics and evaluate the outcomes become important and urgent for clinicians. The review summarizes the latest progress in treatment of clinical biofilm infections and scientific investigations, discusses the diagnosis and treatment of different biofilm infections and introduces the promising laboratory progress, which may contribute to prevention or cure of biofilm infections. We conclude that, an efficient treatment of biofilm infections needs a well-established multidisciplinary collaboration, which includes removal of the infected foreign bodies, selection of biofilm-active, sensitive and well-penetrating antibiotics, systemic or topical antibiotic administration in high dosage and combinations, and administration of anti-quorum sensing or biofilm dispersal agents. PMID:25504208

  13. 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.

  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. 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.

  16. 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. PMID:25787330

  17. 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.

  18. 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

  19. Iron-Based Superparamagnetic Nanoparticle Contrast Agents for MRI of Infection and Inflammation

    PubMed Central

    Neuwelt, Alexander; Sidhu, Navneet; Hu, Chien-An A.; Mlady, Gary; Eberhardt, Steven C.; Sillerud, Laurel O.

    2015-01-01

    OBJECTIVE In this article, we summarize the progress to date on the use of superparamagnetic iron oxide nanoparticles (SPIONs) as contrast agents for MRI of inflammatory processes. CONCLUSION Phagocytosis by macrophages of injected SPIONs results in a prolonged shortening of both T2 and T2* leading to hypointensity of macrophage-infiltrated tissues in contrast-enhanced MR images. SPIONs as contrast agents are therefore useful for the in vivo MRI detection of macrophage infiltration, and there is substantial research and clinical interest in the use of SPION-based contrast agents for MRI of infection and inflammation. This technique has been used to identify active infection in patients with septic arthritis and osteomyelitis; importantly, the MRI signal intensity of the tissue has been found to return to its un-enhanced value on successful treatment of the infection. In SPION contrast-enhanced MRI of vascular inflammation, animal studies have shown decreased macrophage uptake in atherosclerotic plaques after treatment with statin drugs. Human studies have shown that both coronary and carotid plaques that take up SPIONs are more prone to rupture and that abdominal aneurysms with increased SPION uptake are more likely to grow. Studies of patients with multiple sclerosis suggest that MRI using SPIONs may have increased sensitivity over gadolinium for plaque detection. Finally, SPIONs have enabled the tracking and imaging of transplanted stem cells in a recipient host. PMID:25714316

  20. Control strategies for human intestinal nematode infections.

    PubMed

    Albonico, M; Crompton, D W; Savioli, L

    1999-01-01

    In recent years significant progress has been made in understanding the ecology, epidemiology and related morbidity and development of new tools for the control of soil-transmitted helminths. Such knowledge has recognized the impact of helminth infections on the health of infected groups and has created a rational basis for their control. Schoolchildren harbour some of the most intense helminthic infections, which produce adverse effects on health, growth and scholastic performance. However, although great effort has been put into targeting school-age children, women of child-bearing age and pre-school children are two other groups at high risk of morbidity due to intestinal nematode infections. Highly effective and safety-tested, single-dose anthelminthic drugs are now available, permitting periodical deworming of schoolchildren and other high-risk groups at affordable prices. Four anthelminthics against all intestinal nematodes are included in the WHO Essential Drug List (albendazole, levamisole, mebendazole and pyrantel). Recently ivermectin has also been registered for use against Strongyloides stercoralis in humans. Several well-monitored country experiences have shown that chemotherapy-based control of morbidity due to soil-transmitted helminths is possible and highly cost-effective.

  1. SARS: hospital infection control and admission strategies.

    PubMed

    Ho, Pak-Leung; Tang, Xiao-Ping; Seto, Wing-Hong

    2003-11-01

    Nosocomial clustering with transmission to health care workers, patients and visitors is a prominent feature of severe acute respiratory syndrome (SARS). Hospital outbreaks of SARS typically occurred within the first week after admission of the very first SARS cases when the disease was not recognized and before isolation measures were implemented. In the majority of nosocomial infections, there was a history of close contact with a SARS patient, and transmission occurred via large droplets, direct contact with infectious material or by contact with fomites contaminated by infectious material. In a few instances, potential airborne transmission was reported in association with endotracheal intubation, nebulised medications and non-invasive positive pressure ventilation of SARS patients. In all SARS-affected countries, nosocomial transmission of the disease was effectively halted by enforcement of routine standard, contact and droplet precautions in all clinical areas and additional airborne precautions in the high-risk areas. In Hong Kong, where there are few private rooms for patient isolation, some hospitals have obtained good outcome by having designated SARS teams and separate wards for patient triage, confirmed SARS cases and step-down of patients in whom SARS had been ruled out. In conclusion, SARS represents one of the new challenges for those who are involved in hospital infection control. As SARS might re-emerge, all hospitals should take advantage of the current SARS-free interval to review their infection control programmes, alert mechanisms, response capability and to repair any identified inadequacies.

  2. Synergy between twisted conformation and effective intermolecular interactions: strategy for efficient mechanochromic luminogens with high contrast.

    PubMed

    Yuan, Wang Zhang; Tan, Yeqiang; Gong, Yongyang; Lu, Ping; Lam, Jacky W Y; Shen, Xiao Yuan; Feng, Cunfang; Sung, Herman H-Y; Lu, Yawei; Williams, Ian D; Sun, Jing Zhi; Zhang, Yongming; Tang, Ben Zhong

    2013-05-28

    A strategy towards efficient mechanochromic luminogens with high contrast is developed. The twisted propeller-like conformations and effective intermolecular interactions not only endow the luminogens with AIE characteristics and high efficiency in the crystalline state, but also render them to undergo conformational planarization and disruption in intermolecular interactions upon mechanical stimuli, resulting in remarkable changes in emission wavelength and efficiency.

  3. Infection strategies of enteric pathogenic Escherichia coli

    PubMed Central

    Clements, Abigail; Young, Joanna C.; Constantinou, Nicholas; Frankel, Gad

    2012-01-01

    Enteric Escherichia coli (E. coli) are both natural flora of humans and important pathogens causing significant morbidity and mortality worldwide. Traditionally enteric E. coli have been divided into 6 pathotypes, with further pathotypes often proposed. In this review we suggest expansion of the enteric E. coli into 8 pathotypes to include the emerging pathotypes of adherent invasive E. coli (AIEC) and Shiga-toxin producing enteroaggregative E. coli (STEAEC). The molecular mechanisms that allow enteric E. coli to colonize and cause disease in the human host are examined and for two of the pathotypes that express a type 3 secretion system (T3SS) we discuss the complex interplay between translocated effectors and manipulation of host cell signaling pathways that occurs during infection. PMID:22555463

  4. Transmission of nosocomial infection by intravenous catheters: preventive strategies.

    PubMed

    Peleman, R; Vogelaers, D

    1994-12-01

    Intravascular catheter-related bacteraemia puts a major burden on health care due to its associated morbidity and mortality. Because of difficulties in the diagnosis and the consequences of catheter infections, prevention of infection is of the utmost importance. Depending on the setting, the intrinsic and extrinsic risk factors and the patient's personal characteristics, different strategies can be used, but they all focus on catheter care during placement and maintenance of the lines. In this review of the literature, recent data on the aetiology, diagnosis and prevention of catheter-related infections will be discussed.

  5. Radiographic Contrast-Media-Induced Acute Kidney Injury: Pathophysiology and Prophylactic Strategies

    PubMed Central

    2013-01-01

    Contrast-induced acute kidney injury (CI-AKI) is one of the most widely discussed and debated topics in cardiovascular medicine. With increasing number of contrast-media- (CM-) enhanced imaging studies being performed and growing octogenarian population with significant comorbidities, incidence of CI-AKI remains high. In this review, pathophysiology of CI-AKI, its relationship with different types of CM, role of serum and urinary biomarkers for diagnosing CI-AKI, and various prophylactic strategies used for nephroprotection against CI-AKI are discussed in detail. PMID:24967281

  6. Ebola virus (EBOV) infection: Therapeutic strategies.

    PubMed

    De Clercq, Erik

    2015-01-01

    Within less than a year after its epidemic started (in December 2013) in Guinea, Ebola virus (EBOV), a member of the filoviridae, has spread over a number of West-African countries (Guinea, Sierra Leone and Liberia) and gained allures that have been unprecedented except by human immunodeficiency virus (HIV). Although EBOV is highly contagious and transmitted by direct contact with body fluids, it could be counteracted by the adequate chemoprophylactic and -therapeutic interventions: vaccines, antibodies, siRNAs (small interfering RNAs), interferons and chemical substances, i.e. neplanocin A derivatives (i.e. 3-deazaneplanocin A), BCX4430, favipiravir (T-705), endoplasmic reticulum (ER) α-glucosidase inhibitors and a variety of compounds that have been found to inhibit EBOV infection blocking viral entry or by a mode of action that still has to be resolved. Much has to be learned from the mechanism of action of the compounds active against VSV (vesicular stomatitis virus), a virus belonging to the rhabdoviridae, that in its mode of replication could be exemplary for the replication of filoviridae.

  7. Ebola virus (EBOV) infection: Therapeutic strategies.

    PubMed

    De Clercq, Erik

    2015-01-01

    Within less than a year after its epidemic started (in December 2013) in Guinea, Ebola virus (EBOV), a member of the filoviridae, has spread over a number of West-African countries (Guinea, Sierra Leone and Liberia) and gained allures that have been unprecedented except by human immunodeficiency virus (HIV). Although EBOV is highly contagious and transmitted by direct contact with body fluids, it could be counteracted by the adequate chemoprophylactic and -therapeutic interventions: vaccines, antibodies, siRNAs (small interfering RNAs), interferons and chemical substances, i.e. neplanocin A derivatives (i.e. 3-deazaneplanocin A), BCX4430, favipiravir (T-705), endoplasmic reticulum (ER) α-glucosidase inhibitors and a variety of compounds that have been found to inhibit EBOV infection blocking viral entry or by a mode of action that still has to be resolved. Much has to be learned from the mechanism of action of the compounds active against VSV (vesicular stomatitis virus), a virus belonging to the rhabdoviridae, that in its mode of replication could be exemplary for the replication of filoviridae. PMID:25481298

  8. 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.

  9. 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.

  10. 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. PMID:25859152

  11. Reducing implant-related infections: active release strategies.

    PubMed

    Hetrick, Evan M; Schoenfisch, Mark H

    2006-09-01

    Despite sterilization and aseptic procedures, bacterial infection remains a major impediment to the utility of medical implants including catheters, artificial prosthetics, and subcutaneous sensors. Indwelling devices are responsible for over half of all nosocomial infections, with an estimate of 1 million cases per year (2004) in the United States alone. Device-associated infections are the result of bacterial adhesion and subsequent biofilm formation at the implantation site. Although useful for relieving associated systemic infections, conventional antibiotic therapies remain ineffective against biofilms. Unfortunately, the lack of a suitable treatment often leaves extraction of the contaminated device as the only viable option for eliminating the biofilm. Much research has focused on developing polymers that resist bacterial adhesion for use as medical device coatings. This tutorial review focuses on coatings that release antimicrobial agents (i.e., active release strategies) for reducing the incidence of implant-associated infection. Following a brief introduction to bacteria, biofilms, and infection, the development and study of coatings that slowly release antimicrobial agents such as antibiotics, silver ions, antibodies, and nitric oxide are covered. The success and limitations of these strategies are highlighted.

  12. New strategies for local treatment of vaginal infections.

    PubMed

    Palmeira-de-Oliveira, Rita; Palmeira-de-Oliveira, Ana; Martinez-de-Oliveira, José

    2015-09-15

    Vaginal infections are extremely prevalent, particularly among women of reproductive age. Although they do not result in high mortality rates, these infections are associated with high levels of anxiety and reduction of quality of life. In most cases, topical treatment of vaginal infections has been shown to be at least as effective as oral treatment, resulting in higher local drug concentrations, with fewer drug interactions and adverse effects. Furthermore, the emergence of microbial resistance to chemotherapeutics and the difficulties in managing infection recurrences sustain the need for more effective local treatments. However, conventional dosage forms have been associated with low retention in the vagina and discomfort. Formulation strategies such as the development of bioadhesive, thermogelling systems and microtechnological or nanotechnological approaches have been proposed to improve delivery of traditional drugs, and other treatment modalities such as new drugs, plant extracts, and probiotics are being studied. This article reviews the recent strategies studied to improve the treatment and prevention of the commonest vaginal infections-namely, vaginal bacteriosis, aerobic vaginitis, vulvovaginal candidosis, and trichomoniasis-through the intravaginal route.

  13. Coping With Stress Strategies in HIV-infected Iranian Patients.

    PubMed

    Mahmoudi, Maryam; Dehdari, Tahereh; Shojaeezadeh, Davoud; Abbasian, Ladan

    2015-01-01

    Stress has significant adverse impacts on health outcomes of HIV-infected patients. Our study explored coping with stress strategies by HIV-infected Iranian patients. A qualitative content analysis study was conducted at the Consultation Clinic of HIV at the Imam Khomeini Hospital in Tehran, Iran in 2012. Twenty-six semi-structured in-depth interviews were done. Participants were asked about coping strategies for stress. After the first interview, continuous analysis of data was started and continued up to data saturation. Results showed that participants used two categories of strategies (emotion-based coping and problem-based coping) to cope with stress. Emotion-based coping had two sub-themes: adaptive and maladaptive. The problem-based coping category had three sub-themes: participation in education sessions, adherence to medication, and efforts to maintain a healthy lifestyle. Explanations of different strategies available to HIV-infected patients to cope with stress may help develop tailored interventions to improve the psychological conditions of people living with HIV.

  14. 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

  15. 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. PMID:24666264

  16. 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

  17. 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.

  18. 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. PMID:26147535

  19. 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. PMID:26245739

  20. 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.

  1. Wait or escape? Contrasting submergence tolerance strategies of Rorippa amphibia, Rorippa sylvestris and their hybrid

    PubMed Central

    Akman, Melis; Bhikharie, Amit V.; McLean, Elizabeth H.; Boonman, Alex; Visser, Eric J. W.; Schranz, M. Eric; van Tienderen, Peter H.

    2012-01-01

    Background and Aims Differential responses of closely related species to submergence can provide insight into the evolution and mechanisms of submergence tolerance. Several traits of two wetland species from habitats with contrasting flooding regimes, Rorippa amphibia and Rorippa sylvestris, as well as F1 hybrid Rorippa × anceps were analysed to unravel mechanisms underlying submergence tolerance. Methods In the first submergence experiment (lasting 20 d) we analysed biomass, stem elongation and carbohydrate content. In the second submergence experiment (lasting 3 months) we analysed survival and the effect of re-establishment of air contact on biomass and carbohydrate content. In a separate experiment we analysed expression of two carbohydrate catabolism genes, ADH1 and SUS1, upon re-establishment of air contact following submergence. Key Results All plants had low mortality even after 3 months of submergence. Rorippa sylvestris was characterized by 100 % survival and higher carbohydrate levels coupled with lower ADH1 gene expression as well as reduced growth compared with R. amphibia. Rorippa amphibia and the hybrid elongated their stems but this did not pay-off in higher survival when plants remained submerged. Only R. amphibia and the hybrid benefited in terms of increased biomass and carbohydrate accumulation upon re-establishing air contact. Conclusions Results demonstrate contrasting ‘escape’ and ‘quiescence’ strategies between Rorippa species. Being a close relative of arabidopsis, Rorippa is an excellent model for future studies on the molecular mechanism(s) controlling these strategies. PMID:22499857

  2. Strategies for Optimizing Water-Exchange Rates of Lanthanide-Based Contrast Agents for Magnetic Resonance Imaging

    PubMed Central

    Siriwardena-Mahanama, Buddhima N.; Allen, Matthew J.

    2013-01-01

    This review describes recent advances in strategies for tuning the water-exchange rates of contrast agents for magnetic resonance imaging (MRI). Water-exchange rates play a critical role in determining the efficiency of contrast agents; consequently, optimization of water-exchange rates, among other parameters, is necessary to achieve high efficiencies. This need has resulted in extensive research efforts to modulate water-exchange rates by chemically altering the coordination environments of the metal complexes that function as contrast agents. The focus of this review is coordination-chemistry-based strategies used to tune the water-exchange rates of lanthanide(III)-based contrast agents for MRI. Emphasis will be given to results published in the 21st century, as well as implications of these strategies on the design of contrast agents. PMID:23921796

  3. 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.

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

    PubMed Central

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

    2009-01-01

    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. PMID:19474040

  5. Contrasting plasma free amino acid patterns in elite athletes: association with fatigue and infection

    PubMed Central

    Kingsbury, K. J.; Kay, L.; Hjelm, M.

    1998-01-01

    lower plasma creatine kinase activity in group C than in group B (p<0.05) and a low neutrophil to lymphocyte ratio in the athletes with viral infections (1.2 (0.17)), were found. (2) During post-Olympic light training, group A showed no significant amino acid changes. In contrast, group B recovered normal amino acid levels (glutamine 528 (41.4) micromol/l, histidine 76 (5.3) micromol/l, and total amino acids 2772 (165) micromol/l) (p<0.05 to p<0.001) to give a pattern comparable with that of group A, whereas, in group C, valine and threonine had increased (p<0.05), but glutamine (441 (24.5) micromol/l) and histidine (58 (5.3) micromol/l) remained low. Thus none in group A, two in group B, but ten (53%) in group C still had plasma glutamine levels below 450 micromol/l, including eight of the 11 athletes who had presented with infection. (3) With the additional protein intake, virtually all persisting low glutamine levels increased to above 500 micromol/l. Plasma glutamine rose to 592 (35.1) micromol/l and histidine to 86 (6.0) micromol/l. Total amino acids increased to 2761 (128) micromol/l (p<0.05 to p<0.001) and the amino acid pattern normalised. Six of the ten athletes on this protein intake returned to increased training within the three weeks. CONCLUSION: Analysis of these results provided contrasting plasma amino acid patterns: (a) a normal pattern in those without lasting fatigue; (b) marked but temporary changes in those with acute fatigue; (c) a persistent decrease in plasma amino acids, mainly glutamine, in those with chronic fatigue and infection, for which an inadequate protein intake appeared to be a factor. 


 PMID:9562160

  6. Dictyostelium host response to legionella infection: strategies and assays.

    PubMed

    Bozzaro, Salvatore; Peracino, Barbara; Eichinger, Ludwig

    2013-01-01

    The professional phagocyte Dictyostelium discoideum is a simple eukaryotic microorganism, whose natural habitat is deciduous forest soil and decaying leaves, where the amoebae feed on bacteria and grow as separate, independent, single cells. In the last decade, the organism has been successfully used as a host for several human pathogens, including Legionella pneumophila, Mycobacterium avium and Mycobacterium marinum,Pseudomonas aeruginosa, Klebsiella pneumoniae, Cryptococcus neoformans, and Salmonella typhimurium. To dissect the complex cross-talk between host and pathogen Dictyostelium offers easy cultivation, a high quality genome sequence and excellent molecular genetic and biochemical tools. Dictyostelium cells are also extremely suitable for cell biological studies, which in combination with in vivo expression of fluorescence-tagged proteins allow investigating the dynamics of bacterial uptake and infection. Inactivation of genes by homologous recombination as well as gene rescue and overexpression are well established and a large mutant collection is available at the Dictyostelium stock center, favoring identification of host resistance or susceptibility genes. Here, we briefly introduce the organism, address the value of Dictyostelium as model host, describe strategies to identify host cell factors important for infection followed by protocols for cell culture and storage, uptake and infection, and confocal microscopy of infected cells. PMID:23150412

  7. Dictyostelium host response to legionella infection: strategies and assays.

    PubMed

    Bozzaro, Salvatore; Peracino, Barbara; Eichinger, Ludwig

    2013-01-01

    The professional phagocyte Dictyostelium discoideum is a simple eukaryotic microorganism, whose natural habitat is deciduous forest soil and decaying leaves, where the amoebae feed on bacteria and grow as separate, independent, single cells. In the last decade, the organism has been successfully used as a host for several human pathogens, including Legionella pneumophila, Mycobacterium avium and Mycobacterium marinum,Pseudomonas aeruginosa, Klebsiella pneumoniae, Cryptococcus neoformans, and Salmonella typhimurium. To dissect the complex cross-talk between host and pathogen Dictyostelium offers easy cultivation, a high quality genome sequence and excellent molecular genetic and biochemical tools. Dictyostelium cells are also extremely suitable for cell biological studies, which in combination with in vivo expression of fluorescence-tagged proteins allow investigating the dynamics of bacterial uptake and infection. Inactivation of genes by homologous recombination as well as gene rescue and overexpression are well established and a large mutant collection is available at the Dictyostelium stock center, favoring identification of host resistance or susceptibility genes. Here, we briefly introduce the organism, address the value of Dictyostelium as model host, describe strategies to identify host cell factors important for infection followed by protocols for cell culture and storage, uptake and infection, and confocal microscopy of infected cells.

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

    PubMed

    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. 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

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

    PubMed

    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.

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

    PubMed

    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.

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

    PubMed

    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

  13. 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

  14. 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

  15. [Current strategies for prevention of prosthetic joint infection].

    PubMed

    Gallo, J; Landor, I; Vavrík, P

    2006-08-01

    Deep sepsis still remains the second most common cause of prosthetic joint failure despite its overall incidence is decreasing. It can be defined as a bacterial growth and replication on the prosthetic joint surface resulting in periprosthetic tissue damage and prosthesis loosening. The implants are colonized by airborne-, skin-, tool-, and/ or surgeon-related bacteria during surgery even though majority of procedures are performed under strictly respected conditions nowadays. After the insertion of the prosthesis into the human body the race between bacteria and host cells begins on what will colonize the prosthetic surface first. If the bacteria are more successful then they develop on formation of biofilm which is the biological correlative for the prosthetic joint infection (PJI) resisting effectively against host immune response and antibiotics. That is why preventative measures are strongly worth to do it, and removal of the prosthesis is the single optimal treatment. Each step in the pathogenesis of prosthetic joint infection may represent relevant targets against which prevention strategies may be directed. Of them the most useful seems to be identification of individual factors predisposing for PJI development, antibiotic prophylaxis given before the surgery, and operating room/ surgical quality parameters. Key words: prevention, prosthetic joint infection, deep sepsis, biofilm, total joint replacement.

  16. Sampling strategies to measure the prevalence of common recurrent infections in longitudinal studies

    PubMed Central

    2010-01-01

    Background Measuring recurrent infections such as diarrhoea or respiratory infections in epidemiological studies is a methodological challenge. Problems in measuring the incidence of recurrent infections include the episode definition, recall error, and the logistics of close follow up. Longitudinal prevalence (LP), the proportion-of-time-ill estimated by repeated prevalence measurements, is an alternative measure to incidence of recurrent infections. In contrast to incidence which usually requires continuous sampling, LP can be measured at intervals. This study explored how many more participants are needed for infrequent sampling to achieve the same study power as frequent sampling. Methods We developed a set of four empirical simulation models representing low and high risk settings with short or long episode durations. The model was used to evaluate different sampling strategies with different assumptions on recall period and recall error. Results The model identified three major factors that influence sampling strategies: (1) the clustering of episodes in individuals; (2) the duration of episodes; (3) the positive correlation between an individual's disease incidence and episode duration. Intermittent sampling (e.g. 12 times per year) often requires only a slightly larger sample size compared to continuous sampling, especially in cluster-randomized trials. The collection of period prevalence data can lead to highly biased effect estimates if the exposure variable is associated with episode duration. To maximize study power, recall periods of 3 to 7 days may be preferable over shorter periods, even if this leads to inaccuracy in the prevalence estimates. Conclusion Choosing the optimal approach to measure recurrent infections in epidemiological studies depends on the setting, the study objectives, study design and budget constraints. Sampling at intervals can contribute to making epidemiological studies and trials more efficient, valid and cost-effective. PMID

  17. 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.

  18. Competition between the invasive macrophyte Caulerpa taxifolia and the seagrass Posidonia oceanica: contrasting strategies

    PubMed Central

    Pergent, Gérard; Boudouresque, Charles-François; Dumay, Olivier; Pergent-Martini, Christine; Wyllie-Echeverria, Sandy

    2008-01-01

    Background Plant defense strategy is usually a result of trade-offs between growth and differentiation (i.e. Optimal Defense Theory – ODT, Growth Differentiation Balance hypothesis – GDB, Plant Apparency Theory – PAT). Interaction between the introduced green alga Caulerpa taxifolia and the endemic seagrass Posidonia oceanica in the Mediterranean Sea offers the opportunity to investigate the plausibility of these theories. We have accordingly investigated defense metabolite content and growth year-round, on the basis of an interaction gradient. Results When in competition with P. oceanica, C. taxifolia exhibits increased frond length and decreased Caulerpenyne – CYN content (major terpene compound). In contrast, the length of P. oceanica leaves decreases when in competition with C. taxifolia. However, the turnover is faster, resulting in a reduction of leaf longevity and an increase on the number of leaves produced per year. The primary production is therefore enhanced by the presence of C. taxifolia. While the overall concentration of phenolic compounds does not decline, there is an increase in some phenolic compounds (including ferulic acid and a methyl 12-acetoxyricinoleate) and the density of tannin cells. Conclusion Interference between these two species determines the reaction of both, confirming that they compete for space and/or resources. C. taxifolia invests in growth rather than in chemical defense, more or less matching the assumptions of the ODT and/or PAT theories. In contrast, P. oceanica apparently invests in defense rather than growth, as predicted by the GDB hypothesis. However, on the basis of closer scrutiny of our results, the possibility that P. oceanica is successful in finding a compromise between more growth and more defense cannot be ruled out. PMID:19077242

  19. 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

  20. 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.

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

    PubMed

    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

  3. 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

  4. Healthcare-associated infections in neonatal units: lessons from contrasting worlds.

    PubMed

    Srivastava, S; Shetty, N

    2007-04-01

    Neonatal intensive care units are vulnerable to outbreaks and sporadic incidents of healthcare-associated infections (HAIs). The incidence and outcome of these infections are determined by the degree of immaturity of the neonatal immune system, invasive procedures involved, the aetiological agent and its antimicrobial susceptibility pattern and, above all, infection control policies practised by the unit. It is important to raise awareness of infection control practices in resource-limited settings, since overdependence upon antimicrobial agents and co-existing lack of awareness of infection control is encouraging the emergence of multi-drug-resistant nosocomial pathogens. We reviewed 125 articles regarding HAIs from both advanced and resource-limited neonatal units in order to study risk factors, aetiological agents, antimicrobial susceptibility patterns and reported successes in infection control interventions. The articles include surveillance studies, outbreaks and sporadic incidents. Gram-positive cocci, viruses and fungi predominate in reports from the advanced units, while Gram-negative enteric rods, non-fermenters and fungi are commonly reported from resource-limited settings. Antimicrobial susceptibility patterns from surveillance studies determined the empirical therapy used in each neonatal unit. Most outbreaks, irrespective of the technical facilities available, were traced to specific lack of infection control practices. We discuss infection control interventions, with special emphasis on their applicability in resource-limited settings. Cost-effective measures for implementing these interventions, with particular reference to the recognition of the role of the microbiologist, the infection control team and antibiotic policies are presented. PMID:17350726

  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.

    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.

  7. 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

  8. 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.

  9. Self-Regulation Strategies Improve Self-Discipline in Adolescents: Benefits of Mental Contrasting and Implementation Intentions

    ERIC Educational Resources Information Center

    Duckworth, Angela Lee; Grant, Heidi; Loew, Benjamin; Oettingen, Gabriele; Gollwitzer, Peter M.

    2011-01-01

    Adolescents struggle with setting and striving for goals that require sustained self-discipline. Research on adults indicates that goal commitment is enhanced by mental contrasting (MC), a strategy involving the cognitive elaboration of a desired future with relevant obstacles of present reality. Implementation intentions (II), which identify the…

  10. 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.

  11. 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

  12. Strategies for managing hepatitis C virus infection in HIV-infected patients.

    PubMed

    Clanon, Kathleen A

    2003-01-01

    Liver disease associated with hepatitis C virus (HCV) is a significant and increasing cause of death for HIV-infected patients, but limited data exist to guide treatment of coinfection. Increased knowledge of HCV disease and its treatment among HIV care practitioners and adoption of routine care procedures can improve management of coinfected patients. This article discusses HCV screening and diagnosis, counseling and health care maintenance, and evaluation for and supervision of treatment in HIV-seropositive patients who are coinfected with HCV. The experiences of the Oakland, California-based Alameda County Medical Center, which treats more than 200 coinfected patients, are detailed and serve as the basis for suggested management strategies. This article summarizes a presentation given by Kathleen A. Clanon, MD at the November 2002 International AIDS Society-USA course in San Diego. PMID:12717042

  13. Linearization strategies for the Iterative Nonlinear Contrast Source method for full-wave simulation of nonlinear ultrasound fields

    NASA Astrophysics Data System (ADS)

    Verweij, Martin D.; Demi, Libertario; van Dongen, Koen W. A.

    2012-09-01

    The Iterative Nonlinear Contrast Source (INCS) method is a full-wave method for the accurate computation of wide-angle, pulsed, nonlinear ultrasound fields appearing in, e.g., medical echoscopy. The method is based on the Westervelt equation and considers the occurring nonlinear term as a distributed contrast source that operates in a linear background medium. This formulation leads to an integral equation, which is solved in an iterative way. The original INCS method uses a Neumann scheme to successively approximate the nonlinear wave field in homogeneous, lossless, nonlinear media. To cope with attenuative and/or inhomogeneous nonlinear media, additional contrast sources may be introduced. Since these deteriorate the convergence rate of the Neumann scheme, more advanced iterative solution schemes like Bi-CGSTAB are required. To overcome the difficulty that such schemes only apply to linear integral equations, the nonlinear contrast source is linearized, at the cost of a significant systematic error in the fourth and higher harmonics. In this paper, a strategy is proposed in which the relevant iterative solution scheme is restarted with an updated version of the linearized contrast source. Results demonstrate the effectiveness of this strategy in eliminating the systematic error. In addition, it is shown that the same approach also improves the convergence rate in case of nonlinear propagation in media with attenuation.

  14. Dendritic cell subtypes from lymph nodes and blood show contrasted gene expression programs upon Bluetongue virus infection.

    PubMed

    Ruscanu, Suzana; Jouneau, Luc; Urien, Céline; Bourge, Mickael; Lecardonnel, Jérôme; Moroldo, Marco; Loup, Benoit; Dalod, Marc; Elhmouzi-Younes, Jamila; Bevilacqua, Claudia; Hope, Jayne; Vitour, Damien; Zientara, Stéphan; Meyer, Gilles; Schwartz-Cornil, Isabelle

    2013-08-01

    Human and animal hemorrhagic viruses initially target dendritic cells (DCs). It has been proposed, but not documented, that both plasmacytoid DCs (pDCs) and conventional DCs (cDCs) may participate in the cytokine storm encountered in these infections. In order to evaluate the contribution of DCs in hemorrhagic virus pathogenesis, we performed a genome-wide expression analysis during infection by Bluetongue virus (BTV), a double-stranded RNA virus that induces hemorrhagic fever in sheep and initially infects cDCs. Both pDCs and cDCs accumulated in regional lymph nodes and spleen during BTV infection. The gene response profiles were performed at the onset of the disease and markedly differed with the DC subtypes and their lymphoid organ location. An integrative knowledge-based analysis revealed that blood pDCs displayed a gene signature related to activation of systemic inflammation and permeability of vasculature. In contrast, the gene profile of pDCs and cDCs in lymph nodes was oriented to inhibition of inflammation, whereas spleen cDCs did not show a clear functional orientation. These analyses indicate that tissue location and DC subtype affect the functional gene expression program induced by BTV and suggest the involvement of blood pDCs in the inflammation and plasma leakage/hemorrhage during BTV infection in the real natural host of the virus. These findings open the avenue to target DCs for therapeutic interventions in viral hemorrhagic diseases. PMID:23785206

  15. 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

  16. Scaffold-based anti-infection strategies in bone repair.

    PubMed

    Johnson, Christopher T; García, Andrés J

    2015-03-01

    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.

  17. Immune control strategies for vaccinia virus-related laboratory-acquired infections.

    PubMed

    Wei, Qiang; Jiang, Meng Nan; Han, Jun; Wang, Zi Jun

    2014-02-01

    While presenting biological characteristics of vaccinia virus and laboratory-acquired infections during related research processes, this paper focuses on benefits and risks of vaccinia virus immunization in relation to laboratory-acquired infections, describes characteristics and the adaptation of vaccinia virus vaccine, analyses the role vaccinia virus immunization plays in the prevention and control of laboratory-acquired infections, and finally proposes solutions and countermeasures to further promote and implement immune control strategies. The problem related to immune strategy and laboratory- acquired infections which is being raised, analyzed and explored plays an active and instructive role in vaccinia virus related researches and laboratory- acquired infections, and also helps to recommend and develop relevant immune strategy for future vaccine control of such infections.

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

    PubMed

    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

  19. 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

  20. 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…

  1. [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.

  2. 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

  3. 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.

  4. Setting the Agenda in Fund Raising Research: Lessons from Contrasting Strategies. AIR 1986 Annual Forum Paper.

    ERIC Educational Resources Information Center

    Jacobson, Harvey K.; And Others

    Three strategies for conducting research on private gift fund raising in higher education are discussed to promote interaction between institutional researchers and fund-raising officials. Attention is directed to: progress on standardized reporting for cost-effectiveness research; applications of a model for measuring effort, performance, and…

  5. Child and Adult Reports of Graphic Strategies Used to Portray Figures with Contrasting Emotional Characteristics

    ERIC Educational Resources Information Center

    Burkitt, Esther; Barrett, Martyn

    2010-01-01

    This study assessed children's graphic flexibility and their ability to report on their use of drawing strategies when drawing characterized figures. 253 children (129 boys, 124 girls) aged between 4 years 3 months and 11 year 10 months formed three groups, either drawing a man, a dog or a tree. Each group was asked to draw three emotionally…

  6. Health Promotion Strategies for Prevention of Human Immunodeficiency Virus Infection among Minority Adolescents.

    ERIC Educational Resources Information Center

    DiClemente, Ralph J.; Houston-Hamilton, Amanda

    1989-01-01

    This article offers a framework for development and implementation of health education strategies for preventing HIV infection and enhancing health promoting attitudes and behaviors among Black and Latino adolescents. Three HIV prevention program components are identified and discussed. (IAH)

  7. Strategies against human papillomavirus infection and cervical cancer.

    PubMed

    Jung, Woon-Won; Chun, Taehoon; Sul, Donggeun; Hwang, Kwang Woo; Kang, Hyung-Sik; Lee, Duck Joo; Han, In-Kwon

    2004-12-01

    Papillomaviruses infect a wide variety of animals, including humans. The human papillomavirus (HPV), in particular, is one of the most common causes of sexually transmitted disease. More than 200 types of HPV have been identified by DNA sequence data, and 85 HPV genotypes have been well characterized to date. HPV can infect the basal epithelial cells of the skin or inner tissue linings, and are, accordingly, categorized as either cutaneous or mucosal type. HPV is associated with a panoply of clinical conditions, ranging from innocuous lesions to cervical cancer. In the early 1980s, studies first reported a link between cervical cancer and genital HPV infection. Genital HPV infections are now recognized to be a major risk factor in at least 95% of cervical cancers. 30 different HPV genotypes have been identified as causative of sexually transmitted diseases, most of which induce lesions in the cervix, vagina, vulva, penis, and anus, as the result of sexual contact. There is also direct evidence demonstrating that at least four of these genotypes are prerequisite factors in cervical cancer. The main aim of this review was to evaluate the current literature regarding the pathovirology, diagnostics, vaccines, therapy, risk groups, and further therapeutic directions for HPV infections. In addition, we reviewed the current status of HPV infections in South Korean women, as evidenced by our data.

  8. Natural killer T cell strategies to combat Epstein–Barr virus infection

    PubMed Central

    Priatel, John J; Chung, Brian K; Tsai, Kevin; Tan, Rusung

    2014-01-01

    Epstein–Barr virus (EBV) infection results in rapid loss of CD1d expression from the surface of infected B cells, thus enabling the virus to evade immune recognition by natural killer T (NKT) cells. Using pharmacologic means to boost CD1d expression, potent NKT cell effector functions can be elicited toward EBV-infected B cells, suggesting the promise of novel strategies to target EBV-associated diseases such as some B-cell malignancies. PMID:25050206

  9. 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.

  10. 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.

  11. 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

  12. 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.

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

    PubMed

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

    2015-12-15

    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 twofold 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 (area under the 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.

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

    PubMed

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

    2015-12-15

    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 twofold 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 (area under the 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

  15. Multihospital infection prevention collaborative: informatics challenges and strategies to prevent MRSA.

    PubMed

    Doebbeling, Bradley N; Flanagan, Mindy E; Nall, Glenna; Hoke, Shawn; Rosenman, Marc; Kho, Abel

    2013-01-01

    We formed a collaborative to spread effective MRSA prevention strategies. We conducted a two-phase, multisite, quasi-experimental study of seven hospital systems (11 hospitals) in IN, MT, ME and Ontario, Canada over six years. Patients with prior MRSA were identified at admission using regional health information exchange data. We developed a system to return an alert message indicating a prior history of MRSA, directed to infection preventionists and admissions. Alerts indicated the prior anatomic site, and the originating institution. The combined approach of training and coaching, implementation of MRSA registries, notifying hospitals on admission of previously infected or colonized patients, and change strategies was effective in reducing MRSA infections over 80%. Further research and development of electronic surveillance tools is needed to better integrate the varied data source and support preventing MRSA infections. Our study supports the importance of hospitals collaborating to share data and implement effective strategies to prevent MRSA.

  16. Preventive strategy for BVDV infection in North America

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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,...

  17. Preventive strategy for BVDV infection in North America

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite control efforts, bovine viral diarrhea virus (BVDV) infections remain a source of significant economic loss for producers in the United States. The success of control efforts in Scandinavia has demonstrated that BVDV eradication is possible. However, it is not possible to take a “one size fi...

  18. 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

  19. 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...

  20. 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

  1. Seasonality Directs Contrasting Food Collection Behavior and Nutrient Regulation Strategies in Ants

    PubMed Central

    Cook, Steven C.; Eubanks, Micky D.; Gold, Roger E.; Behmer, Spencer T.

    2011-01-01

    Long-lived animals, including social insects, often display seasonal shifts in foraging behavior. Foraging is ultimately a nutrient consumption exercise, but the effect of seasonality per se on changes in foraging behavior, particularly as it relates to nutrient regulation, is poorly understood. Here, we show that field-collected fire ant colonies, returned to the laboratory and maintained under identical photoperiod, temperature, and humidity regimes, and presented with experimental foods that had different protein (p) to carbohydrate (c) ratios, practice summer- and fall-specific foraging behaviors with respect to protein-carbohydrate regulation. Summer colonies increased the amount of food collected as the p:c ratio of their food became increasingly imbalanced, but fall colonies collected similar amounts of food regardless of the p:c ratio of their food. Choice experiments revealed that feeding was non-random, and that both fall and summer ants preferred carbohydrate-biased food. However, ants rarely ate all the food they collected, and their cached or discarded food always contained little carbohydrate relative to protein. From a nutrient regulation strategy, ants consumed most of the carbohydrate they collected, but regulated protein consumption to a similar level, regardless of season. We suggest that varied seasonal food collection behaviors and nutrient regulation strategies may be an adaptation that allows long-lived animals to meet current and future nutrient demands when nutrient-rich foods are abundant (e.g. spring and summer), and to conserve energy and be metabolically more efficient when nutritionally balanced foods are less abundant. PMID:21966522

  2. Contrasting bacterial strategies to coexist with a flagellate predator in an experimental microbial assemblage.

    PubMed

    Pernthaler, J; Posch, T; Simek, K; Vrba, J; Amann, R; Psenner, R

    1997-02-01

    We studied predator-induced changes within a slowly growing mixed microbial assemblage that was sustained by algal exudates in a continuous cultivation system. In situ hybridization with fluorescent monolabeled oligonucleotide probes was used for a tentative community analysis. This method also allowed us to quantify the proportions of predators with ingested bacteria of different taxonomic groups. In addition, we determined grazing rates on bacteria with fluorescently labelled prey. Bacteria belonging to the alpha and beta subdivisions of the phylum Proteobacteria ((alpha)- and (beta)-Proteobacteria, respectively) showed very different responses to the addition of a bacterivorous flagellate, Bodo saltans. Within one day, filamentous protist-inedible bacteria developed; these belonged to the (beta)-Proteobacteria and constituted between 8.7 and 34% of bacteria from this subgroup. Total abundance of (beta)-Proteobacteria decreased from 3.05 x 10(sup6) to 0.23 x 10(sup6) cells ml(sup-1), and estimated cell division rates were low. Other morphologically inconspicuous protist-edible bacteria belonging to the (alpha)-Proteobacteria were found to respond to predation by an increase in growth rate. Although these bacteria were heavily grazed upon, as on average >85% of flagellate cells had ingested (alpha)-Proteobacteria, they numerically dominated after the addition of B. saltans (mean, 1.35 x 10(sup6) cells ml(sup-1)). It was thus mainly those fast-dividing strains of (alpha)-Proteobacteria that supported the growth of the flagellate population. We conclude that bacteria in mixed assemblages can adopt at least two distinct strategies as a reaction to intense flagellate predation: to outgrow predation pressure or to develop inedible, inactive filaments. Since these strategies occurred within 24 h after the addition of the flagellate, we hypothesize that chemical stimuli released by the predator may have triggered bacterial responses. PMID:16535516

  3. Contrasting Bacterial Strategies To Coexist with a Flagellate Predator in an Experimental Microbial Assemblage

    PubMed Central

    Pernthaler, J.; Posch, T.; Simek, K.; Vrba, J.; Amann, R.; Psenner, R.

    1997-01-01

    We studied predator-induced changes within a slowly growing mixed microbial assemblage that was sustained by algal exudates in a continuous cultivation system. In situ hybridization with fluorescent monolabeled oligonucleotide probes was used for a tentative community analysis. This method also allowed us to quantify the proportions of predators with ingested bacteria of different taxonomic groups. In addition, we determined grazing rates on bacteria with fluorescently labelled prey. Bacteria belonging to the alpha and beta subdivisions of the phylum Proteobacteria ((alpha)- and (beta)-Proteobacteria, respectively) showed very different responses to the addition of a bacterivorous flagellate, Bodo saltans. Within one day, filamentous protist-inedible bacteria developed; these belonged to the (beta)-Proteobacteria and constituted between 8.7 and 34% of bacteria from this subgroup. Total abundance of (beta)-Proteobacteria decreased from 3.05 x 10(sup6) to 0.23 x 10(sup6) cells ml(sup-1), and estimated cell division rates were low. Other morphologically inconspicuous protist-edible bacteria belonging to the (alpha)-Proteobacteria were found to respond to predation by an increase in growth rate. Although these bacteria were heavily grazed upon, as on average >85% of flagellate cells had ingested (alpha)-Proteobacteria, they numerically dominated after the addition of B. saltans (mean, 1.35 x 10(sup6) cells ml(sup-1)). It was thus mainly those fast-dividing strains of (alpha)-Proteobacteria that supported the growth of the flagellate population. We conclude that bacteria in mixed assemblages can adopt at least two distinct strategies as a reaction to intense flagellate predation: to outgrow predation pressure or to develop inedible, inactive filaments. Since these strategies occurred within 24 h after the addition of the flagellate, we hypothesize that chemical stimuli released by the predator may have triggered bacterial responses. PMID:16535516

  4. Contrasting bacterial strategies to coexist with a flagellate predator in an experimental microbial assemblage.

    PubMed

    Pernthaler, J; Posch, T; Simek, K; Vrba, J; Amann, R; Psenner, R

    1997-02-01

    We studied predator-induced changes within a slowly growing mixed microbial assemblage that was sustained by algal exudates in a continuous cultivation system. In situ hybridization with fluorescent monolabeled oligonucleotide probes was used for a tentative community analysis. This method also allowed us to quantify the proportions of predators with ingested bacteria of different taxonomic groups. In addition, we determined grazing rates on bacteria with fluorescently labelled prey. Bacteria belonging to the alpha and beta subdivisions of the phylum Proteobacteria ((alpha)- and (beta)-Proteobacteria, respectively) showed very different responses to the addition of a bacterivorous flagellate, Bodo saltans. Within one day, filamentous protist-inedible bacteria developed; these belonged to the (beta)-Proteobacteria and constituted between 8.7 and 34% of bacteria from this subgroup. Total abundance of (beta)-Proteobacteria decreased from 3.05 x 10(sup6) to 0.23 x 10(sup6) cells ml(sup-1), and estimated cell division rates were low. Other morphologically inconspicuous protist-edible bacteria belonging to the (alpha)-Proteobacteria were found to respond to predation by an increase in growth rate. Although these bacteria were heavily grazed upon, as on average >85% of flagellate cells had ingested (alpha)-Proteobacteria, they numerically dominated after the addition of B. saltans (mean, 1.35 x 10(sup6) cells ml(sup-1)). It was thus mainly those fast-dividing strains of (alpha)-Proteobacteria that supported the growth of the flagellate population. We conclude that bacteria in mixed assemblages can adopt at least two distinct strategies as a reaction to intense flagellate predation: to outgrow predation pressure or to develop inedible, inactive filaments. Since these strategies occurred within 24 h after the addition of the flagellate, we hypothesize that chemical stimuli released by the predator may have triggered bacterial responses.

  5. 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

  6. 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. PMID:26720213

  7. 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.

  8. Cost-effectiveness of strategies to prevent MRSA transmission and infection in an intensive care unit

    PubMed Central

    Gidengil, Courtney; Gay, Charlene; Huang, Susan S; Platt, Richard; Yokoe, Deborah; Lee, Grace M.

    2014-01-01

    Objective We created a national policy model to evaluate the projected cost-effectiveness of multiple hospital-based strategies to prevent MRSA transmission and infection. Design Cost-effectiveness analysis using a Markov microsimulation model that simulates the natural history of MRSA acquisition and infection. Patients and setting Hypothetical cohort of 10,000 adult patients admitted to a U.S. ICU. Methods We compared 7 strategies to standard precautions using a hospital perspective: (1) active surveillance cultures (ASC); (2) ASC plus selective decolonization; (3) universal contact precautions (UCP); (4) universal chlorhexidine gluconate (CHG) baths; (5) universal decolonization; (6) UCP + CHG baths; and (7) UCP + decolonization. For each strategy, both efficacy and compliance were considered. Outcomes of interest were: (1) MRSA colonization averted; (2) MRSA infection averted; (3) incremental cost per colonization averted; (4) incremental cost per infection averted. Results 1,989 cases of colonization and 544 MRSA invasive infections occurred under standard precautions per 10,000 patients. Universal decolonization was the least expensive strategy and was more effective compared to all strategies except UCP + decolonization and UCP + CHG. UCP + decolonization was more effective than universal decolonization, but would cost $2,469 per colonization averted and $9,007 per infection averted. If MRSA colonization prevalence drops from 12% to 5%, ASC plus selective decolonization becomes the least expensive strategy. Conclusions Universal decolonization is cost-saving, preventing 44% of cases of MRSA colonization and 45% of cases of MRSA infection. Our model provides useful guidance for decision makers choosing between multiple available hospital-based strategies to prevent MRSA transmission. PMID:25627757

  9. Current and novel antiviral strategies for influenza infection.

    PubMed

    Yen, Hui-Ling

    2016-06-01

    Influenza A and B viruses are major causes for respiratory infections in children and adults. Viral and host factors determine clinical manifestations which range from self-resolving uncomplicated infections, severe viral or bacterial secondary pneumonia, to death. Emergence of transmissible resistant variants and time-dependent effectiveness are the major challenges for the currently approved antivirals, M2 ion channel blockers and neuraminidase (NA) inhibitors. Favipiravir that inhibits the RNA-dependent RNA polymerase of multiple RNA viruses is approved in Japan against influenza strains resistant to available antivirals. With expanded knowledge on viral nucleoprotein (NP) and polymerase structures, novel small molecule inhibitors targeting NP oligomer formation, PA endonuclease domain, and the PB2 cap-binding domain are being developed. Combination therapy with different antiviral compounds or with host immune response modulators may further benefit clinical outcomes.

  10. Novel antiviral strategies to combat human Arenavirus infections.

    PubMed

    Kunz, Stefan; de la Torre, Juan C

    2005-12-01

    Arenaviruses merit significant attention both as tractable model systems to study acute and persistent viral infections, and as clinically important human pathogens. Evidence indicates that LCMV remains present in the USA and Europe and capable of causing significant morbidity in infected individuals, likely being a neglected human pathogen. Moreover, new arenaviruses are being discovered in the Americas on the average of one every three years, with some of them causing severe hemorrhagic fever. In addition, weaponized forms of these viruses pose a real threat as agents of bioterrorism. Therefore, it is important to develop effective vaccines and better antiviral drugs to combat the dual threats of naturally occurring and intentionally introduced Arenavirus infections. The development of arenavirus reverse genetic systems is allowing investigators to conduct a detailed molecular characterization of the viral cis-acting signals and trans-acting factors that control each of the steps of the Arenavirus life cycle, including RNA synthesis, packaging and budding. We will discuss how this new knowledge is facilitating the establishment of novel assays to identify and characterize compounds capable of interfering with specific steps of the virus life cycle. Likewise, the ability to generate predetermined specific mutations within the arenavirus genome, and analyze their phenotypic expression, would significantly contribute to the elucidation of arenavirus-host interactions, including the bases of their ability to persist, as well as to cause severe HF (hemorrhagic fever) disease in humans. These approaches could also lead to the development of novel potent and safe Arenavirus vaccines. PMID:16375709

  11. Trace Metal Acquisition by Marine Heterotrophic Bacterioplankton with Contrasting Trophic Strategies

    PubMed Central

    Barbeau, Katherine A.

    2016-01-01

    Heterotrophic bacteria in the SAR11 and Roseobacter lineages shape the marine carbon, nitrogen, phosphorous, and sulfur cycles, yet they do so having adopted divergent ecological strategies. Currently, it is unknown whether these globally significant groups partition into specific niches with respect to micronutrients (e.g., trace metals) and how that may affect marine trace metal cycling. Here, we used comparative genomics to identify diverse iron, cobalt, nickel, copper, and zinc uptake capabilities in SAR11 and Roseobacter genomes and uncover surprising unevenness within and between lineages. The strongest predictors for the extent of the metal uptake gene content are the total number of transporters per genome, genome size, total metal transporters, and GC content, but numerous exceptions exist in both groups. Taken together, our results suggest that SAR11 have strongly minimized their trace metal uptake versatility, with high-affinity zinc uptake being a unique exception. The larger Roseobacter genomes have greater trace metal uptake versatility on average, but they also appear to have greater plasticity, resulting in phylogenetically similar genomes having largely different capabilities. Ultimately, phylogeny is predictive of the diversity and extent of 20 to 33% of all metal uptake systems, suggesting that specialization in metal utilization mostly occurred independently from overall lineage diversification in both SAR11 and Roseobacter. We interpret these results as reflecting relatively recent trace metal niche partitioning in both lineages, suggesting that concentrations and chemical forms of metals in the marine environment are important factors shaping the gene content of marine heterotrophic Alphaproteobacteria of the SAR11 and Roseobacter lineages. PMID:26729720

  12. Trace Metal Acquisition by Marine Heterotrophic Bacterioplankton with Contrasting Trophic Strategies.

    PubMed

    Hogle, Shane L; Thrash, J Cameron; Dupont, Chris L; Barbeau, Katherine A

    2016-03-01

    Heterotrophic bacteria in the SAR11 and Roseobacter lineages shape the marine carbon, nitrogen, phosphorous, and sulfur cycles, yet they do so having adopted divergent ecological strategies. Currently, it is unknown whether these globally significant groups partition into specific niches with respect to micronutrients (e.g., trace metals) and how that may affect marine trace metal cycling. Here, we used comparative genomics to identify diverse iron, cobalt, nickel, copper, and zinc uptake capabilities in SAR11 and Roseobacter genomes and uncover surprising unevenness within and between lineages. The strongest predictors for the extent of the metal uptake gene content are the total number of transporters per genome, genome size, total metal transporters, and GC content, but numerous exceptions exist in both groups. Taken together, our results suggest that SAR11 have strongly minimized their trace metal uptake versatility, with high-affinity zinc uptake being a unique exception. The larger Roseobacter genomes have greater trace metal uptake versatility on average, but they also appear to have greater plasticity, resulting in phylogenetically similar genomes having largely different capabilities. Ultimately, phylogeny is predictive of the diversity and extent of 20 to 33% of all metal uptake systems, suggesting that specialization in metal utilization mostly occurred independently from overall lineage diversification in both SAR11 and Roseobacter. We interpret these results as reflecting relatively recent trace metal niche partitioning in both lineages, suggesting that concentrations and chemical forms of metals in the marine environment are important factors shaping the gene content of marine heterotrophic Alphaproteobacteria of the SAR11 and Roseobacter lineages. PMID:26729720

  13. Management strategies to reduce risk of postoperative infections

    PubMed Central

    Galor, Anat; Goldhardt, Raquel; Wellik, Sarah R.; Gregori, Ninel Z.; Flynn, Harry W.

    2013-01-01

    Postoperative infections, although rare, are still of great concern to the ophthalmologist. The incidence of post-cataract endophthalmitis is low, with a range of .28 per 1,000 to 2.99 per 1000. In addition to intraoperative considerations such as poor wound construction, vitreous loss, topical anesthesia, and prolonged surgical time, other risk factors include preoperative factors such as a diseased ocular surface and systemic immunosuppression. Potential methods of reducing risk of endophthalmitis after anterior segment surgery are discussed and available literature is summarized. PMID:24319649

  14. 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

  15. Intervention strategies for an influenza pandemic taking into account secondary bacterial infections.

    PubMed

    Handel, Andreas; Longini, Ira M; Antia, Rustom

    2009-09-01

    Influenza infections often predispose individuals to consecutive bacterial infections. Both during seasonal and pandemic influenza outbreaks, morbidity and mortality due to secondary bacterial infections can be substantial. With the help of a mathematical model, we investigate the potential impact of such bacterial infections during an influenza pandemic, and we analyze how antiviral and antibacterial treatment or prophylaxis affect morbidity and mortality. We consider different scenarios for the spread of bacteria, the emergence of antiviral resistance, and different levels of severity for influenza infections (1918-like and 2009-like). We find that while antibacterial intervention strategies are unlikely to play an important role in reducing the overall number of cases, such interventions can lead to a significant reduction in mortality and in the number of bacterial infections. Antibacterial interventions become even more important if one considers the--very likely--scenario that during a pandemic outbreak, influenza strains resistant to antivirals emerge. Overall, our study suggests that pandemic preparedness plans should consider intervention strategies based on antibacterial treatment or prophylaxis through drugs or vaccines as part of the overall control strategy. A major caveat for our results is the lack of data that would allow precise estimation of many of the model parameters. As our results show, this leads to very large uncertainty in model outcomes. As we discuss, precise assessment of the impact of antibacterial strategies during an influenza pandemic will require the collection of further data to better estimate key parameters, especially those related to the bacterial infections and the impact of antibacterial intervention strategies.

  16. 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.

  17. 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. PMID:22077120

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

    PubMed

    Chen, Li; Wen, Yu-mei

    2011-04-01

    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.

  20. 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. PMID:26907881

  1. Oomycete interactions with plants: infection strategies and resistance principles.

    PubMed

    Fawke, Stuart; Doumane, Mehdi; Schornack, Sebastian

    2015-09-01

    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.

  2. Contrasting Micro/Nano Architecture on Termite Wings: Two Divergent Strategies for Optimising Success of Colonisation Flights

    PubMed Central

    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 C18 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. PMID:21935401

  3. 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.

  4. 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

  5. [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.

  6. [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. PMID:19492518

  7. 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

  8. Infection.

    PubMed

    Saigal, Gaurav; Nagornaya, Natalya; Post, M Judith D

    2016-01-01

    Imaging is useful in the diagnosis and management of infections of the central nervous system. Typically, imaging findings at the outset of the disease are subtle and nonspecific, but they often evolve to more definite imaging patterns in a few days, with less rapidity than for stroke but faster than for neoplastic lesions. This timing is similar to that of noninfectious inflammatory brain disease, such as multiple sclerosis. Fortunately, imaging patterns help to distinguish the two kinds of processes. Other than for sarcoidosis, the meninges are seldom involved in noninfectious inflammation; in contrast, many infectious processes involve the meninges, which then enhance with contrast on computed tomography (CT) or magnetic resonance imaging (MRI). However, brain infection causes a vast array of imaging patterns. Although CT is useful when hemorrhage or calcification is suspected or bony detail needs to be determined, MRI is the imaging modality of choice in the investigation of intracranial infections. Imaging sequences such as diffusion-weighted imaging help in accurately depicting the location and characterizing pyogenic infections and are particularly useful in differentiating bacterial infections from other etiologies. Susceptibility-weighted imaging is extremely useful for the detection of hemorrhage. Although MR spectroscopy findings can frequently be nonspecific, certain conditions such as bacterial abscesses show a relatively specific spectral pattern and are useful in diagnosing and constituting immediate therapy. In this chapter we review first the imaging patterns associated with involvement of various brain structures, such as the epidural and subdural spaces, the meninges, the brain parenchyma, and the ventricles. Involvement of these regions is illustrated with bacterial infections. Next we illustrate the patterns associated with viral and prion diseases, followed by mycobacterial and fungal infections, to conclude with a review of imaging findings

  9. 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

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

    PubMed Central

    Fawke, Stuart; 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

  11. 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. PMID

  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. Quiescent Innate Response to Infective Filariae by Human Langerhans Cells Suggests a Strategy of Immune Evasion

    PubMed Central

    Boyd, Alexis; Bennuru, Sasisekhar; Wang, Yuanyuan; Sanprasert, Vivornpun; Law, Melissa; Chaussabel, Damien; Nutman, Thomas B.

    2013-01-01

    Filarial infection is initiated by mosquito-derived third-stage larvae (L3) deposited on the skin that transit through the epidermis, which contains Langerhans cells (LC) and keratinocytes (KC), among other cells. This earliest interaction between L3 and the LC likely conditions the priming of the immune system to the parasite. To determine the nature of this interaction, human LC (langerin+ E-cadherin+ CD1a+) were generated in vitro and exposed to live L3. LC exposed to live L3 for 48 h showed no alterations in the cell surface markers CD14, CD86, CD83, CD207, E-cadherin, CD80, CD40, and HLA-DR or in mRNA expression of inflammation-associated genes, such as those for interleukin 18 (IL-18), IL-18BP, and caspase 1. In contrast to L3, live tachyzoites of Toxoplasma gondii, an intracellular parasite, induced production of CXCL9, IP-10, and IL-6 in LC. Furthermore, preexposure of LC to L3 did not alter Toll-like receptor 3 (TLR3)- or TLR4-mediated expression of the proinflammatory cytokines IL-1β, gamma interferon (IFN-γ), IL-6, or IL-10. Interestingly, cocultures of KC and LC produced significantly more IL-18, IL-1α, and IL-8 than did cultures of LC alone, although exposure of the cocultures to live L3 did not result in altered cytokine production. Microarray examination of ex vivo LC from skin blisters that were exposed to live L3 also showed few significant changes in gene expression compared with unexposed blisters, further underscoring the relatively muted response of LC to L3. Our data suggest that failure by LC to initiate an inflammatory response to the invasive stage of filarial parasites may be a strategy for immune evasion by the filarial parasite. PMID:23429540

  14. 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

  15. 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. PMID:26936670

  16. Anti-infective catheters: novel strategies to prevent nosocomial infections in oncology.

    PubMed

    Schierholz, J M; Rump, A F; Pulverer, G; Beuth, J

    1998-01-01

    Intravenous access contributes significantly to the therapeutical success and to the comfort of oncologic patients. The highest risk for bloodstream infections, however, is vascular catheter-mediated. In oncology high mortality is associated with Pseudomonas aeruginosa, Candida albicans and Staphylococcus aureus sepsis. Besides established hygienic measures, the coupling or incorporation of antimicrobial substances to or into catheter materials may be a suitable way to prevent the development of catheter-associated infections. Here we present a risk- benefit evaluation of different models of antimicrobial catheter coated with silver, antiseptics or antibiotics. The controversial reports on clinical efficacy and the potential of adverse reactions due to silver and antiseptic coated catheters are discussed. The microbiological, pharmaceutical and physicochemical backgrounds of different types of coating are discussed in detail. Incorporation of antimicrobial agents into long-term silicon catheters providing a slow release of those substances through the external and internal surfaces of catheters may be the most effective technological innovation for reducing biomaterial-mediated nosocomial infections. PMID:9854469

  17. 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

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

    PubMed

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

    2013-04-01

    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

  19. Innovative Solutions to Sticky Situations: Antiadhesive Strategies for Treating Bacterial Infections.

    PubMed

    Cusumano, Zachary T; Klein, Roger D; Hultgren, Scott J

    2016-04-01

    Bacterial adherence to host tissue is an essential process in pathogenesis, necessary for invasion and colonization and often required for the efficient delivery of toxins and other bacterial effectors. As existing treatment options for common bacterial infections dwindle, we find ourselves rapidly approaching a tipping point in our confrontation with antibiotic-resistant strains and in desperate need of new treatment options. Bacterial strains defective in adherence are typically avirulent and unable to cause infection in animal models. The importance of this initial binding event in the pathogenic cascade highlights its potential as a novel therapeutic target. This article seeks to highlight a variety of strategies being employed to treat and prevent infection by targeting the mechanisms of bacterial adhesion. Advancements in this area include the development of novel antivirulence therapies using small molecules, vaccines, and peptides to target a variety of bacterial infections. These therapies target bacterial adhesion through a number of mechanisms, including inhibition of pathogen receptor biogenesis, competition-based strategies with receptor and adhesin analogs, and the inhibition of binding through neutralizing antibodies. While this article is not an exhaustive description of every advancement in the field, we hope it will highlight several promising examples of the therapeutic potential of antiadhesive strategies. PMID:27227305

  20. 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

  1. Management of aortic graft infections - the present strategy and future perspectives.

    PubMed

    Treska, V; Certik, B; Molacek, J

    2016-01-01

    Aortic graft infections (AGI) are serious complications of open and endovascular types of surgery with an incidence rate of 0.6-3 %. AGI are associated with 30-60 % perioperative mortality and 40-60 % morbidity rate with limb amputation rates between 10 % and 40 %. The economic cost of AGI is substantial. At the time of aortic reconstruction, almost 90 % of patients have one or more predisposing factors for AGI. The diagnosis is based on clinical symptomatology, laboratory markers, microbial cultures, and imaging modalities. The general principle of surgical treatment lies in the removal of infected graft, debridement of infected periprosthetic tissues, and vascular reconstruction by in situ or extra-anatomic bypass with long-term antibiotic therapy. The conservative treatment is used only for selected patients with endograft infection. This review summarizes the current knowledge about the incidence, predisposing factors, etiology, diagnosis, treatment options, and prevention of aortic vascular graft and endograft infections. With the growing number of endovascular procedures we can expect more cases of infected aortic endografts in patients with severe comorbidities in the near future, where the recent radical surgical approach (graft excision, debridement, and new revascularization) cannot be used. Therefore the less invasive, sophisticated and individualized treatment strategies will have to be used in search of the best therapeutic approach to each specific patient (Fig. 4, Ref. 82). PMID:26925740

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

    PubMed Central

    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. PMID:24294593

  3. 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. PMID:24294593

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

    PubMed

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

    2010-09-01

    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.

  5. 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

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

    PubMed

    Sunagar, Kartik; Moran, Yehu

    2015-10-01

    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 shaping animal

  7. 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.

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

    PubMed

    Sunagar, Kartik; Moran, Yehu

    2015-10-01

    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 shaping animal

  9. 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

  10. 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.

  11. Conflict between parasites with different transmission strategies infecting an amphipod host.

    PubMed

    Haine, Eleanor R; Boucansaud, Karelle; Rigaud, Thierry

    2005-12-01

    Competition between parasites within a host can influence the evolution of parasite virulence and host resistance, but few studies examine the effects of unrelated parasites with conflicting transmission strategies infecting the same host. Vertically transmitted (VT) parasites, transmitted from mother to offspring, are in conflict with virulent, horizontally transmitted (HT) parasites, because healthy hosts are necessary to maximize VT parasite fitness. Resolution of the conflict between these parasites should lead to the evolution of one of two strategies: avoidance, or sabotage of HT parasite virulence by the VT parasite. We investigated two co-infecting parasites in the amphipod host, Gammarus roeseli: VT microsporidia have little effect on host fitness, but acanthocephala modify host behaviour, increasing the probability that the amphipod is predated by the acanthocephalan's definitive host. We found evidence for sabotage: the behavioural manipulation induced by the Acanthocephala Polymorphus minutus was weaker in hosts also infected by the microsporidia Dictyocoela sp. (roeselum) compared to hosts infected by P. minutus alone. Such conflicts may explain a significant portion of the variation generally observed in behavioural measures, and since VT parasites are ubiquitous in invertebrates, often passing undetected, conflict via transmission may be of great importance in the study of host-parasite relationships.

  12. 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

  13. Screening for Respiratory Syncytial Virus and Isolation Strategies in Children Hospitalized With acute Respiratory Tract Infection

    PubMed Central

    Pfeil, Johannes; Tabatabai, Julia; Sander, Anja; Ries, Markus; Grulich-Henn, Jürgen; Schnitzler, Paul

    2014-01-01

    Abstract Nosocomial infection with respiratory syncytial virus (RSV) is an important health risk in pediatric care but is largely preventable by efficient infection control measures. Commonly applied rapid antigen detection tests (RADTs) miss a considerable number of RSV-infected patients. The objective of our analysis was to evaluate whether readily available host parameters are associated with false-negative RADT, and to assess how these parameters could be applied in an optimized RSV isolation strategy. We retrospectively analyzed a cohort of 242 children under the age of 2 years hospitalized with acute respiratory tract infection to identify host parameters associated with false-negative RADT test result. We subsequently simulated the outcome of different isolation strategies based on RADT result and host parameters in view of the overall isolation efficacy. Out of 242 hospitalized patients, 134 (55%) patients were found RSV-positive by RT-PCR, whereas 108 (45%) patients were tested negative. The performance of the RADT was compared with the result obtained by reverse transcription polymerase chain reaction on the identical nasopharyngeal wash. Overall, we found that 85 patients (35%) were tested true positive, 108 (45%) were tested true negative, whereas a false-negative test result was obtained in 49 patients (20%). Duration of respiratory symptoms for >3 days and a respiratory admission diagnosis are associated with false-negative RADT result. In comparison with RADT alone, consideration of these clinical parameters and RADT result can decrease the rate of nonisolated RSV-infected patients from approximately 24% to 8% (65% RSV pretest probability). Consideration of both RADT and clinical parameters associated with false-negative RADT can result in an optimized RSV infection control policy. PMID:25437026

  14. Promising Antibody Testing Strategies for Early Infant HIV Infection Diagnosis in China

    PubMed Central

    Su, Xueli; Yao, Jun; Jiang, Yan; Li, Jie; Han, Jianfeng; Sun, Weidong

    2014-01-01

    Background In China, 1.1% of people living with HIV were transmitted vertically, causing a heavy burden on families and society. Early infant diagnosis (EID) is critical for improving neonatal survival. The purpose of this study is to suggest improvement in antibody testing strategies with dried blood spots (DBSs) for EID in China through analysis of anti-HIV seroreversion of infants. Methods A total of 280 infants born to HIV infected mothers in four diverse provinces of China where multiple subtypes coexist were enrolled. The status of the infants' infection was determined by HIV antibody enzyme immunoassay and Western blot analysis at ≥18 months of age or by convincing clinical and epidemiologic data for deceased infants. A total of 1028 DBSs were collected during follow-up, which were tested to obtain anti-HIV signal to cut-off ratio (S/CO) data. Results For uninfected infants, anti-HIV S/CO decreased with age. Seropositivity percentage declined most rapidly at 6 months to 9 months of age and 98.7% children seroreverted by 12 months of age. For most infected infants, minimum S/CO values were obtained at ≤6 months of age. Antibody negative predictive value was 100% at ≥6 months of age. An S/CO increase ≥1.86 after three months follow-up can determine HIV infection. S/CO threshold of 3.17 can differentiate infected from uninfected infants for exposed kids at 9 months or older with sensitivity as 100% and specificity ≥94.2%. Significance Suggestions obtained through studying seroreversion data of Chinese HIV-exposed infants help improve antibody strategies for HIV EID in China. The infection can be determined as early as 3 months of age and excluded as early as 6 months of age. PMID:24971594

  15. Genistein-Supplemented Diet Decreases Malaria Liver Infection in Mice and Constitutes a Potential Prophylactic Strategy

    PubMed Central

    Prudêncio, Miguel; Gonçalves, Lígia A.; Casalou, Cristina; Buger, Dominik; Sauerwein, Robert; Haas, Werner; Mota, Maria M.

    2008-01-01

    In tropical regions millions of people still live at risk of malaria infection. Indeed the emergence of resistance to chloroquine and other drugs in use in these areas reinforces the need to implement alternative prophylactic strategies. Genistein is a naturally occurring compound that is widely used as a food supplment and is thought to be effective in countering several pathologies. Results presented here show that genistein inhibits liver infection by the Plasmodium parasite, the causative agent of malaria. In vitro, genistein decreased the infection rates of both mouse and human hepatoma cells by inhibiting the early stages of the parasite's intracellular development. Oral or intraperitoneal administration of genistein decreased the liver parasite load of P. berghei-infected mice. Moreover, mice fed on a genistein-supplemented diet showed a significant reduction in Plasmodium liver infection as well as a reduced blood parasitemia and partial protection from severe disease. Since genistein is a safe, low-cost, natural compound that can be used permanently in a diet, we propose its use as a prophylactic agent against malaria for endemic populations and long-time travelers. PMID:18628947

  16. 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.

  17. 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. PMID:24940920

  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. 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

  20. 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

  1. 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. PMID:27195984

  2. Contrasting infection susceptibility of the Japanese macaques and cynomolgus macaques to closely related malaria parasites, Plasmodium vivax and Plasmodium cynomolgi.

    PubMed

    Tachibana, Shin-Ichiro; Kawai, Satoru; Katakai, Yuko; Takahashi, Hideo; Nakade, Toru; Yasutomi, Yasuhiro; Horii, Toshihiro; Tanabe, Kazuyuki

    2015-06-01

    Although the human malaria parasite Plasmodium vivax is closely related to Asian Old World monkey malaria parasites, there are no reports of P. vivax infections in macaques. In this study, we compared the infectivity of P. vivax and Plasmodium cynomolgi in Japanese macaques (Macaca fuscata) and in cynomolgus macaques (Macaca fascicularis). The Japanese macaques were highly susceptible to P. cynomolgi but not to P. vivax, whereas cynomolgus macaques showed mild/limited P. cynomolgi infection and were, also, not susceptible to P. vivax. Serotyping and amino acid sequence comparison of erythrocyte surface Duffy antigen/receptor for chemokines (DARC) indicate that the Japanese macaque DARC sequence is nearly identical to that of rhesus (Macaca mulatta) and cynomolgus macaques. This suggests that the macaques share a common mechanism for preventing P. vivax infection. Comparison of amino acid sequences of the Duffy-binding-like (DBL) domain from several different Plasmodium species suggests that P. vivax DBLs will not bind to macaque DARCs, which can explain the lack of P. vivax infectivity. The DBL sequence analyses also suggest that P. cynomolgi DBLs may target Japanese macaque erythrocytes through a DARC-independent interaction.

  3. 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

  4. 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

  5. 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).

  6. Heat shock protein-based therapeutic strategies against human immunodeficiency virus type 1 infection.

    PubMed Central

    Brenner, B G; Wainberg, M A

    1999-01-01

    Heat shock proteins (hsps) and cyclophilins (CypA) are intracellular chaperone molecules that facilitate protein folding and assembly. These proteins are selectively expressed in cells following exposure to a range of stress stimuli, including viral infection. Hsp species are highly immunogenic, eliciting humoral, cytotoxic T lymphocyte (CTL), and natural killer (NK) cell responses against viruses, tumours, and infectious diseases. This review discusses the roles of stress proteins in immunity and viral life cycles, vis-à-vis the development of Hsp-based therapeutic strategies against human immunodeficiency virus type-1 (HIV-1) infection. Cumulative findings are cited implicating the requirement of CypA in HIV-1 replication and formation of infectious virions. Studies by our group show the upregulated expression of hsp27 and hsp70 during single-cycle HIV infections. These species redistribute to the cell surface following HIV-infection and heat stress, serving as targets for NK and antibody-dependent cellular cytotoxicity. Co-immunoprecipitation and Western blot studies show that hsp27, hsp70, and hsp78 complex with HIV-1 viral proteins intracellularly. Hsp70, hsp56, and CypA are assembled into HIV-1 virions. The ability of hsps to interact with HIV-1 viral proteins, combined with their inherent adjuvant and immunogenic properties, indicates that hsps may serve as vehicles for antigen delivery and the design of vaccines against acquired immunodeficiency syndrome. PMID:10231014

  7. 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).

  8. Waterborne microorganisms and biofilms related to hospital infections: strategies for prevention and control in healthcare facilities.

    PubMed

    Capelletti, Raquel Vannucci; Moraes, Ângela Maria

    2016-02-01

    Water is the main stimulus for the development of microorganisms, and its flow has an important role in the spreading of contaminants. In hospitals, the water distribution system requires special attention since it can be a source of pathogens, including those in the form of biofilms often correlated with resistance of microorganisms to various treatments. In this paper, information relevant to cases of nosocomial infections involving water circuits as a source of contaminants is compiled, with emphasis on the importance of microbiological control strategies to prevent the installation, spreading and growth of microorganisms in hospitals. An overview of the worldwide situation is provided, with emphasis on Brazilian hospitals. Different approaches normally used to control the occurrence of nosocomial infections due to waterborne contaminants are analyzed, and the use of the polysaccharide chitosan for this specific application is briefly discussed.

  9. Waterborne microorganisms and biofilms related to hospital infections: strategies for prevention and control in healthcare facilities.

    PubMed

    Capelletti, Raquel Vannucci; Moraes, Ângela Maria

    2016-02-01

    Water is the main stimulus for the development of microorganisms, and its flow has an important role in the spreading of contaminants. In hospitals, the water distribution system requires special attention since it can be a source of pathogens, including those in the form of biofilms often correlated with resistance of microorganisms to various treatments. In this paper, information relevant to cases of nosocomial infections involving water circuits as a source of contaminants is compiled, with emphasis on the importance of microbiological control strategies to prevent the installation, spreading and growth of microorganisms in hospitals. An overview of the worldwide situation is provided, with emphasis on Brazilian hospitals. Different approaches normally used to control the occurrence of nosocomial infections due to waterborne contaminants are analyzed, and the use of the polysaccharide chitosan for this specific application is briefly discussed. PMID:26837830

  10. 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

  11. 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

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

    NASA Astrophysics Data System (ADS)

    Ikejimba, Lynda; Kiarashi, Nooshin; Lin, Yuan; Chen, Baiyu; Ghate, Sujata V.; Zerhouni, Moustafa; Samei, Ehsan; Lo, Joseph Y.

    2012-03-01

    Digital breast tomosynthesis (DBT) is a novel x-ray imaging technique that provides 3D structural information of the breast. In contrast to 2D mammography, DBT minimizes tissue overlap potentially improving cancer detection and reducing number of unnecessary recalls. The addition of a contrast agent to DBT and mammography for lesion enhancement has the benefit of providing functional information of a lesion, as lesion contrast uptake and washout patterns may help differentiate between benign and malignant tumors. This study used a task-based method to determine the optimal imaging approach by analyzing six imaging paradigms in terms of their ability to resolve iodine at a given dose: contrast enhanced mammography and tomosynthesis, temporal subtraction mammography and tomosynthesis, and dual energy subtraction mammography and tomosynthesis. Imaging performance was characterized using a detectability index d', derived from the system task transfer function (TTF), an imaging task, iodine contrast, and the noise power spectrum (NPS). The task modeled a 5 mm 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. In general, higher dose gave higher d', but for the lowest iodine concentration and lowest dose, dual energy subtraction tomosynthesis and temporal subtraction tomosynthesis demonstrated the highest performance.

  13. 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.

  14. 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. PMID:25676113

  15. 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

  16. Lack of genetic differentiation between contrasted overwintering strategies of a major pest predator Episyrphus balteatus (Diptera: Syrphidae): implications for biocontrol.

    PubMed

    Raymond, Lucie; Plantegenest, Manuel; Gauffre, Bertrand; Sarthou, Jean-Pierre; Vialatte, Aude

    2013-01-01

    Winter ecology of natural enemies has a great influence on the level and efficiency of biological control at spring. The hoverfly Episyrphus balteatus (DeGeer) (Diptera: Syrphidae) is one of the most important natural predators of crop aphids in Europe. Three different overwintering strategies coexist in this species which makes it a good model in order to study ecologically-based speciation processes. The purpose of this study was to determine whether E. balteatus populations with alternative overwintering strategies are genetically differentiated. To that aim, we developed 12 specific microsatellite markers and evaluated the level of neutral genetic differentiation between E. balteatus field populations that overwinter in the three different ways described in this species (i.e. migration, local overwintering at a pre-imaginal stage, and local overwintering at adult stage). Results showed a lack of neutral genetic differentiation between individuals with different overwintering strategies although there are strong ecological differences between them. All pair-wise FST values are below 0.025 and non-significant, and Bayesian clustering showed K=1 was the most likely number of genetic clusters throughout our sample. The three overwintering strategies form one unique panmictic population. This suggests that all the individuals may have genetic material for the expression of different overwintering phenotypes, and that their commitment in one particular overwintering strategy may depend on environmental and individual factors. Consequently, the prevalence of the different overwintering strategies would be potentially modified by landscape engineering and habitat management which could have major implications for biological control.

  17. Cost-Effectiveness Analysis of Six Strategies to Treat Recurrent Clostridium difficile Infection

    PubMed Central

    Lapointe-Shaw, Lauren; Tran, Kim L.; Coyte, Peter C.; Hancock-Howard, Rebecca L.; Powis, Jeff; Poutanen, Susan M.; Hota, Susy

    2016-01-01

    Objective To assess the cost-effectiveness of six treatment strategies for patients diagnosed with recurrent Clostridium difficile infection (CDI) in Canada: 1. oral metronidazole; 2. oral vancomycin; 3.oral fidaxomicin; 4. fecal transplantation by enema; 5. fecal transplantation by nasogastric tube; and 6. fecal transplantation by colonoscopy. Perspective Public insurer for all hospital and physician services. Setting Ontario, Canada. Methods A decision analytic model was used to model costs and lifetime health effects of each strategy for a typical patient experiencing up to three recurrences, over 18 weeks. Recurrence data and utilities were obtained from published sources. Cost data was obtained from published sources and hospitals in Toronto, Canada. The willingness-to-pay threshold was $50,000/QALY gained. Results Fecal transplantation by colonoscopy dominated all other strategies in the base case, as it was less costly and more effective than all alternatives. After accounting for uncertainty in all model parameters, there was an 87% probability that fecal transplantation by colonoscopy was the most beneficial strategy. If colonoscopy was not available, fecal transplantation by enema was cost-effective at $1,708 per QALY gained, compared to metronidazole. In addition, fecal transplantation by enema was the preferred strategy if the probability of recurrence following this strategy was below 8.7%. If fecal transplantation by any means was unavailable, fidaxomicin was cost-effective at an additional cost of $25,968 per QALY gained, compared to metronidazole. Conclusion Fecal transplantation by colonoscopy (or enema, if colonoscopy is unavailable) is cost-effective for treating recurrent CDI in Canada. Where fecal transplantation is not available, fidaxomicin is also cost-effective. PMID:26901316

  18. 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.

  19. 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. PMID:21056106

  20. 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. PMID:25211122

  1. Lack of Genetic Differentiation between Contrasted Overwintering Strategies of a Major Pest Predator Episyrphus balteatus (Diptera: Syrphidae): Implications for Biocontrol

    PubMed Central

    Raymond, Lucie; Plantegenest, Manuel; Gauffre, Bertrand; Sarthou, Jean-Pierre; Vialatte, Aude

    2013-01-01

    Winter ecology of natural enemies has a great influence on the level and efficiency of biological control at spring. The hoverfly Episyrphus balteatus (DeGeer) (Diptera: Syrphidae) is one of the most important natural predators of crop aphids in Europe. Three different overwintering strategies coexist in this species which makes it a good model in order to study ecologically-based speciation processes. The purpose of this study was to determine whether E. balteatus populations with alternative overwintering strategies are genetically differentiated. To that aim, we developed 12 specific microsatellite markers and evaluated the level of neutral genetic differentiation between E. balteatus field populations that overwinter in the three different ways described in this species (i.e. migration, local overwintering at a pre-imaginal stage, and local overwintering at adult stage). Results showed a lack of neutral genetic differentiation between individuals with different overwintering strategies although there are strong ecological differences between them. All pair-wise FST values are below 0.025 and non-significant, and Bayesian clustering showed K = 1 was the most likely number of genetic clusters throughout our sample. The three overwintering strategies form one unique panmictic population. This suggests that all the individuals may have genetic material for the expression of different overwintering phenotypes, and that their commitment in one particular overwintering strategy may depend on environmental and individual factors. Consequently, the prevalence of the different overwintering strategies would be potentially modified by landscape engineering and habitat management which could have major implications for biological control. PMID:24023799

  2. 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

  3. 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

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

    PubMed

    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

  6. 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

  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. 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

  9. 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

  10. Cellulose degradation: a therapeutic strategy in the improved treatment of Acanthamoeba infections.

    PubMed

    Lakhundi, Sahreena; Siddiqui, Ruqaiyyah; Khan, Naveed Ahmed

    2015-01-01

    Acanthamoeba is an opportunistic free-living amoeba that can cause blinding keratitis and fatal brain infection. Early diagnosis, followed by aggressive treatment is a pre-requisite in the successful treatment but even then the prognosis remains poor. A major drawback during the course of treatment is the ability of the amoeba to enclose itself within a shell (a process known as encystment), making it resistant to chemotherapeutic agents. As the cyst wall is partly made of cellulose, thus cellulose degradation offers a potential therapeutic strategy in the effective targeting of trophozoite encased within the cyst walls. Here, we present a comprehensive report on the structure of cellulose and cellulases, as well as known cellulose degradation mechanisms with an eye to target the Acanthamoeba cyst wall. The disruption of the cyst wall will make amoeba (concealed within) susceptible to chemotherapeutic agents, and at the very least inhibition of the excystment process will impede infection recurrence, as we bring these promising drug targets into focus so that they can be explored to their fullest.

  11. 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

    2016-01-01

    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. PMID:27580688

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

    PubMed Central

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

    2016-01-01

    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. PMID:27580688

  13. 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

  14. 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.

  15. 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

  16. 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.

  17. 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. PMID:26791981

  18. Economic Evaluation of Laboratory Testing Strategies for Hospital-Associated Clostridium difficile Infection

    PubMed Central

    Robilotti, Elizabeth; Peterson, Lance R.; Banaei, Niaz; Dowdy, David W.

    2014-01-01

    Clostridium difficile infection (CDI) is the most common cause of infectious diarrhea in health care settings, and for patients presumed to have CDI, their isolation while awaiting laboratory results is costly. Newer rapid tests for CDI may reduce this burden, but the economic consequences of different testing algorithms remain unexplored. We used decision analysis from the hospital perspective to compare multiple CDI testing algorithms for adult inpatients with suspected CDI, assuming patient management according to laboratory results. CDI testing strategies included combinations of on-demand PCR (odPCR), batch PCR, lateral-flow diagnostics, plate-reader enzyme immunoassay, and direct tissue culture cytotoxicity. In the reference scenario, algorithms incorporating rapid testing were cost-effective relative to nonrapid algorithms. For every 10,000 symptomatic adults, relative to a strategy of treating nobody, lateral-flow glutamate dehydrogenase (GDH)/odPCR generated 831 true-positive results and cost $1,600 per additional true-positive case treated. Stand-alone odPCR was more effective and more expensive, identifying 174 additional true-positive cases at $6,900 per additional case treated. All other testing strategies were dominated by (i.e., more costly and less effective than) stand-alone odPCR or odPCR preceded by lateral-flow screening. A cost-benefit analysis (including estimated costs of missed cases) favored stand-alone odPCR in most settings but favored odPCR preceded by lateral-flow testing if a missed CDI case resulted in less than $5,000 of extended hospital stay costs and <2 transmissions, if lateral-flow GDH diagnostic sensitivity was >93%, or if the symptomatic carrier proportion among the toxigenic culture-positive cases was >80%. These results can aid guideline developers and laboratory directors who are considering rapid testing algorithms for diagnosing CDI. PMID:24478478

  19. 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

  20. [Strategies for Mycobacterium avium complex infection control in Japan: how do they improve the present situation?].

    PubMed

    Ogawa, Kenji; Sano, Chiaki

    2013-03-01

    Mycobacterium avium complex (MAC) were the most frequently isolated (about 80%) and most common cause of lung nontuberculosis. Its rate of infection is globally increasing, especially in Japan. In this situation, it is urgently needed to provide scientific evidences and develop therapeutic interventions in MAC infections. Recently, more and more patients are elderly women with no history of smoking, and they have reticulonodular infiltrates and patchy bilateral bronchiectasis. However the prognostic and intractable factors of MAC infections are poorly known. In this symposium, we address five novel strategies for MAC infection, concerning the more accurate incidence and prevalence rates compared with other countries, host defense associated with Th1/Th17 balance, route of MAC infection related soil exposure, MAC IgA antibody as a diagnosis maker, and improved chemotherapy including aminoglycoside or new quinolone. Appropriate clinical intervention may help to reduce the prolongation of MAC infection or enhance the activity of chemotherapy for the improved control of MAC. Below are the abstracts for each of the five speakers. 1. Review of current epidemiological study of pulmonary nontuberculous mycobacterial disease in Japan and the rest of the world: Kozo MORIMOTO (Respiratory Center, Fukujuji Hospital, Japan Anti-Tuberculosis Association) The studies on pulmonary nontuberculous mycobacterial (NTM) disease prevalence were started in early 1970s in Japan by the Mycobacteriosis Research Group of National Chest Hospitals. They were followed by a questionnaire survey in 1990s, by the National Tuberculosis and NTM Survey in late 1990s, and recently by the questionnaire surveys conducted by the NTM Disease Research Committee. The latest data in Japan (from 2007) indicated a morbidity rate of 5.7 per 100,000 population. Deaths from NTM disease were reported for the first time in 1970 and showed a marked, steady increase until 2007, with 912 deaths in that year. We

  1. 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.

  2. 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

  3. Contrasting adaptive strategies to terminal drought-stress gradients in Mediterranean legumes: phenology, productivity, and water relations in wild and domesticated Lupinus luteus L.

    PubMed Central

    Berger, J. D.; Ludwig, C.

    2014-01-01

    Our understanding of within-species annual plant adaptation to rainfall gradients is fragmented. Broad-scale ecological applications of Grime’s C-S-R triangle are often superficial, while detailed drought physiology tends to be narrow, focusing on elite cultivars. The former lack the detail to explain how plants respond, while the latter provide little context to investigate trade-offs among traits, to explain where/why these might be adaptive. Ecophysiology, combining the breadth of the former with the detail of the latter, can resolve this disconnect and is applied here to describe adaptive strategies in the Mediterranean legume Lupinus luteus. Wild and domesticated material from low- and high-rainfall environments was evaluated under contrasting terminal drought. These opposing environments have selected for contrasting, integrated, adaptive strategies. Long-season, high-rainfall habitats select for competitive (C) traits: delayed phenology, high above- and below-ground biomass, productivity, and fecundity, leading to high water-use and early stress onset. Terminal drought-prone environments select for the opposite: ruderal (R) traits that facilitate drought escape/avoidance but limit reproductive potential. Surprisingly, high-rainfall ecotypes generate lower critical leaf water potentials under water deficit, maintaining higher relative water content than the latter. Given that L. luteus evolved in sandy, low-water-holding capacity soils, this represents a bet-hedging response to intermittent self-imposed water-deficits associated with a strongly C-selected adaptive strategy that is therefore redundant in R-selected low-rainfall ecotypes. Domesticated L. luteus is even more R-selected, reflecting ongoing selection for early maturity. Introgression of appropriate C-selected adaptive traits from wild germplasm may widen the crop production range. PMID:24591050

  4. Contrasting adaptive strategies to terminal drought-stress gradients in Mediterranean legumes: phenology, productivity, and water relations in wild and domesticated Lupinus luteus L.

    PubMed

    Berger, J D; Ludwig, C

    2014-11-01

    Our understanding of within-species annual plant adaptation to rainfall gradients is fragmented. Broad-scale ecological applications of Grime's C-S-R triangle are often superficial, while detailed drought physiology tends to be narrow, focusing on elite cultivars. The former lack the detail to explain how plants respond, while the latter provide little context to investigate trade-offs among traits, to explain where/why these might be adaptive. Ecophysiology, combining the breadth of the former with the detail of the latter, can resolve this disconnect and is applied here to describe adaptive strategies in the Mediterranean legume Lupinus luteus. Wild and domesticated material from low- and high-rainfall environments was evaluated under contrasting terminal drought. These opposing environments have selected for contrasting, integrated, adaptive strategies. Long-season, high-rainfall habitats select for competitive (C) traits: delayed phenology, high above- and below-ground biomass, productivity, and fecundity, leading to high water-use and early stress onset. Terminal drought-prone environments select for the opposite: ruderal (R) traits that facilitate drought escape/avoidance but limit reproductive potential. Surprisingly, high-rainfall ecotypes generate lower critical leaf water potentials under water deficit, maintaining higher relative water content than the latter. Given that L. luteus evolved in sandy, low-water-holding capacity soils, this represents a bet-hedging response to intermittent self-imposed water-deficits associated with a strongly C-selected adaptive strategy that is therefore redundant in R-selected low-rainfall ecotypes. Domesticated L. luteus is even more R-selected, reflecting ongoing selection for early maturity. Introgression of appropriate C-selected adaptive traits from wild germplasm may widen the crop production range.

  5. 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.

  6. 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...

  7. Evaluation of methicillin-resistant Staphylococcus aureus skin and soft-tissue infection prevention strategies at a military training center.

    PubMed

    Morrison, Stephanie M; Blaesing, Carl R; Millar, Eugene V; Chukwuma, Uzo; Schlett, Carey D; Wilkins, Kenneth J; Tribble, David R; Ellis, Michael W

    2013-08-01

    Military trainees are at high risk for skin and soft-tissue infections (SSTIs), especially those caused by methicillin-resistant Staphylococcus aureus (MRSA). A multicomponent hygiene-based SSTI prevention strategy was implemented at a military training center. After implementation, we observed 30% and 64% reductions in overall and MRSA-associated SSTI rates, respectively.

  8. 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

  9. 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.

  10. Infection.

    PubMed

    Miclau, Theodore; Schmidt, Andrew H; Wenke, Joseph C; Webb, Lawrence X; Harro, Janette M; Prabhakara, Ranjani; Shirtliff, Mark E

    2010-09-01

    Musculoskeletal infection is a clinical problem with significant direct healthcare costs. The prevalence of infection after closed, elective surgery is frequently estimated to be less than 2%, but in severe injuries, posttraumatic infection rates have been reported as 10% or greater. Although clinical infections are found outside the realm of medical devices, it is clear that the enormous increase of infections associated with the use of implants presents a major challenge worldwide. This review summarizes recent advances in the understanding, diagnosis, and treatment of musculoskeletal infections.

  11. Limiting factors to encapsulation: the combined effects of dissolved protein and oxygen availability on embryonic growth and survival of species with contrasting feeding strategies.

    PubMed

    Brante, Antonio; Fernández, Miriam; Viard, Frédérique

    2009-07-01

    Encapsulation is a common strategy among marine invertebrate species. It has been shown that oxygen and food availability independently constrain embryo development during intracapsular development. However, it is unclear how embryos of species with different feeding strategies perceive these two constraints when operating jointly. In the present study, we examined the relative importance of dissolved albumen, as a food source, oxygen condition and their interaction on embryonic growth and the survival of two calyptraeid species, Crepidula coquimbensis and Crepidula fornicata, exhibiting different embryo feeding behaviours (i.e. presence vs absence of intracapsular cannibalism). Two oxygen condition treatments (normoxia and hypoxia) and three albumen concentrations (0, 1 and 2 mg l(-1)) were studied. In addition, albumen intake by embryos was observed using fluorescence microscopy. Our study shows that embryos of both species incorporated dissolved albumen but used a different set of embryonic organs. We observed that embryo growth rates in C. coquimbensis were negatively affected only by hypoxic conditions. Conversely, a combination of low albumen concentration and oxygen availability slowed embryo growth in C. fornicata. These findings suggest that oxygen availability is a limiting factor for the normal embryo development of encapsulated gastropod species, regardless of feeding behaviour or developmental mode. By contrast, the effect of dissolved albumen as an alternative food source on embryo performance may depend on the feeding strategy of the embryos.

  12. 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.

  13. 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

  14. 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

  15. Cost-effectiveness analysis of treatment strategies for initial Clostridium difficile infection.

    PubMed

    Varier, R U; Biltaji, E; Smith, K J; Roberts, M S; Jensen, M K; LaFleur, J; Nelson, R E

    2014-12-01

    Clostridium difficile infection (CDI) is costly. Current guidelines recommend metronidazole as first-line therapy and vancomycin as an alternative. Recurrence is common. Faecal microbiota transplantation (FMT) is an effective therapy for recurrent CDI (RCDI). This study explores the cost-effectiveness of FMT, vancomycin and metronidazole for initial CDI. We constructed a decision-analytic computer simulation using inputs from published literature to compare FMT with a 10-14-day course of oral metronidazole or vancomycin for initial CDI. Parameters included cure rates (baseline value (range)) for metronidazole (80% (65-85%)), vancomycin (90% (88-92%)) and FMT(91% (83-100%)). Direct costs of metronidazole, vancomycin and FMT, adjusted to 2011 dollars, were $57 ($43-72), $1347 ($1195-1499) and $1086 ($815-1358), respectively. Our effectiveness measure was quality-adjusted life years (QALYs). One-way and probabilistic sensitivity analyses were conducted from the third-party payer perspective. Analysis using baseline values showed that FMT($1669, 0.242 QALYs) dominated (i.e. was less costly and more effective) vancomycin ($1890, 0.241 QALYs). FMT was more costly and more effective than metronidazole ($1167, 0.238 QALYs), yielding an incremental cost-effectiveness ratio (ICER) of $124 964/QALY. One-way sensitivity analyses showed that metronidazole dominated both strategies if its probability of cure were >90%; FMT dominated if it cost <$584. In a probabilistic sensitivity analysis at a willingness-to-pay threshold of $100 000/QALY, metronidazole was favoured in 55% of model iterations; FMT was favoured in 38%. Metronidazole, as the first-line treatment for CDIs, is less costly. FMT and vancomycin are more effective. However, FMT is less likely to be economically favourable, and vancomycin is unlikely to be favourable as first-line therapy when compared with FMT.

  16. Central nervous system HIV infection in "less-drug regimen" antiretroviral therapy simplification strategies.

    PubMed

    Ferretti, Francesca; Gianotti, Nicola; Lazzarin, Adriano; Cinque, Paola

    2014-02-01

    Less-drug regimens (LDR) refer to combinations of either two antiretroviral drugs or ritonavir-boosted protease inhibitor (PI) monotherapy. They may represent a simplification strategy in patients with persistently suppressed human immunodeficiency virus (HIV) viremia, with the main benefits of reducing drug-related toxicities and costs. Systemic virological efficacy of LDR is slightly lower as compared with combined antiretroviral therapy (cART), but patients with failure do not usually develop drug resistance and resuppress HIV replication after reintensification. A major concern of LDR is the lower efficacy in the virus reservoirs, especially in the central nervous system (CNS), where viral compartmentalization and independent evolution of infection may lead to CNS viral escape, often associated with neurologic symptoms. The authors reviewed studies of virological and functional CNS efficacy of LDR, particularly of boosted PI monotherapy regimens, for which more information is available. Symptomatic viral CSF escape was observed mainly in PI/r monotherapy patients with plasma failure and low nadir CD4+ cell counts, and resolved upon reintroduction of triple drug cART, whereas asymptomatic viral failure in CSF was not significantly more frequent in patients on PI/r monotherapy compared with patients on standard cART. In addition, there was no difference in functional outcomes between PI monotherapy and cART patients, irrespective of CSF viral escape. More data are needed on the CNS effect of dual ART regimens and, in general, on long-term efficacy of LDR. Simplification with LDR may be an attractive option in patients with suppressed viral load, if they are well selected and monitored for potential CNS complications.

  17. Neuroendoscopic surgery for ventriculitis and hydrocephalus after shunt infection and malfunction: Preliminary report of a new strategy

    PubMed Central

    Tabuchi, Sadaharu; Kadowaki, Mitsutoshi

    2015-01-01

    If not controlled in the early stage, ventriculitis is difficult to treat neurosurgically and can lead to serious sequelae, a long course of treatment, and hospitalization. We report two cases of ventriculitis and progressive hydrocephalus after shunt infection. Both were successfully treated by neuroendoscopic septostomy in combination with thorough intraventricular irrigation through a single burr hole followed by single shunt revision. Although surgical intervention has not been established as a first-choice treatment for ventriculitis, including early-stage ventriculitis, prompt neuroendoscopic surgery appears effective for the management of ventriculitis and hydrocephalus after shunt infection. The strategy described in this report might be useful to avoid recurrent shunt infections and malfunctions, simplify a shunt, and reduce the overall duration of hospitalization. PMID:25913583

  18. Neuroendoscopic surgery for ventriculitis and hydrocephalus after shunt infection and malfunction: Preliminary report of a new strategy.

    PubMed

    Tabuchi, Sadaharu; Kadowaki, Mitsutoshi

    2015-05-01

    If not controlled in the early stage, ventriculitis is difficult to treat neurosurgically and can lead to serious sequelae, a long course of treatment, and hospitalization. We report two cases of ventriculitis and progressive hydrocephalus after shunt infection. Both were successfully treated by neuroendoscopic septostomy in combination with thorough intraventricular irrigation through a single burr hole followed by single shunt revision. Although surgical intervention has not been established as a first-choice treatment for ventriculitis, including early-stage ventriculitis, prompt neuroendoscopic surgery appears effective for the management of ventriculitis and hydrocephalus after shunt infection. The strategy described in this report might be useful to avoid recurrent shunt infections and malfunctions, simplify a shunt, and reduce the overall duration of hospitalization. PMID:25913583

  19. 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.

  20. Novel Strategies for the Diagnosis of Posttraumatic Infections in Orthopaedic Trauma Patients.

    PubMed

    Firoozabadi, Reza; Alton, Timothy; Wenke, Joseph

    2015-07-01

    Orthopaedic infections that occur after trauma are common. Clinical examination, laboratory markers, imaging modalities, and culture and molecular technologies are used to aid the diagnosis of infection. Culture methods comprise the backbone of diagnostic systems used in hospital laboratory settings; however, several studies have questioned the ability of these techniques to adequately identify infections, particularly in cases where orthopaedic implants were used or when the presence of biofilm bacteria is suspected. Advances in imaging and molecular diagnostics can provide orthopaedic surgeons with an improved means of diagnosing and treating infections.

  1. Treatment and Prophylactic Strategy for Coxiella burnetii Infection of Aneurysms and Vascular Grafts: A Retrospective Cohort Study.

    PubMed

    Eldin, Carole; Mailhe, Morgane; Lions, Caroline; Carrieri, Patrizia; Safi, Hazem; Brouqui, Philippe; Raoult, Didier

    2016-03-01

    Coxiella burnetii vascular infections continue to be very severe diseases and no guidelines exist about their prevention. In terms of treatment, the benefit of the surgical removal of infected tissues has been suggested by 1 retrospective study.We present a case of a C burnetii abdominal aortic graft infection for which we observed a dramatic clinical and biological recovery after surgery. We thus performed a retrospective cohort study to evaluate the impact of surgery on survival and serological outcome for patients with Q fever vascular infections diagnosed in our center.Between 1986 and February 2015, 100 patients were diagnosed with Q fever vascular infections. The incidence of these infections has significantly increased over the past 5 years, in comparison with the mean annual incidence over the preceding 22 years (8.83 cases per year versus 3.14 cases per year, P = 0.001). A two-and-a-half-year follow-up was available for 66 patients, of whom 18.2% died. We observed 6.5% of deaths in the group of patients who were operated upon at 2 and a half years, in comparison with 28.6% in the group which were not operated upon (P = 0.02). Surgery was the only factor that had a positive impact on survival at 2 and a half years using univariate analysis [hazard ratio: 0.17 [95% CI]: [0.039-0.79]; P = 0.024]. Surgery was also associated with a good serological outcome (74.1% vs 57.1% of patients, P = 0.03). In the group of patients with vascular graft infections (n = 47), surgery had a positive impact on serological outcome at 2 and a half years (85.7% vs 42.9%, P < 0.001) [hazard ratio: 0.40 [95% CI]: [0.17-098]; P = 0.046] and tended to be associated with lower although not statistically significant mortality (11.1% vs 27.6% of deaths, P = 0.19).Surgical treatment confers a benefit in terms of survival following C burnetii vascular infections. However, given the high mortality of these infections and their rising incidence, we propose a

  2. Building and Strengthening Infection Control Strategies to Prevent Tuberculosis - Nigeria, 2015.

    PubMed

    Dokubo, E Kainne; Odume, Bethrand; Lipke, Virginia; Muianga, Custodio; Onu, Eugene; Olutola, Ayodotun; Ukachukwu, Lucy; Igweike, Patricia; Chukwura, Nneka; Ubochioma, Emperor; Aniaku, Everistus; Ezeudu, Chinyere; Agboeze, Joseph; Iroh, Gabriel; Orji, Elvina; Godwin, Okezue; Raji, Hasiya Bello; Aboje, S A; Osakwe, Chijioke; Debem, Henry; Bello, Mustapha; Onotu, Dennis; Maloney, Susan

    2016-03-18

    Tuberculosis (TB) is the leading cause of infectious disease mortality worldwide, accounting for more than 1.5 million deaths in 2014, and is the leading cause of death among persons living with human immunodeficiency virus (HIV) infection (1). Nigeria has the fourth highest annual number of TB cases among countries, with an estimated incidence of 322 per 100,000 population (1), and the second highest prevalence of HIV infection, with 3.4 million infected persons (2). In 2014, 100,000 incident TB cases and 78,000 TB deaths occurred among persons living with HIV infection in Nigeria (1). Nosocomial transmission is a significant source of TB infection in resource-limited settings (3), and persons with HIV infection and health care workers are at increased risk for TB infection because of their routine exposure to patients with TB in health care facilities (3-5). A lack of TB infection control in health care settings has resulted in outbreaks of TB and drug-resistant TB among patients and health care workers, leading to excess morbidity and mortality. In March 2015, in collaboration with the Nigeria Ministry of Health (MoH), CDC implemented a pilot initiative, aimed at increasing health care worker knowledge about TB infection control, assessing infection control measures in health facilities, and developing plans to address identified gaps. The approach resulted in substantial improvements in TB infection control practices at seven selected facilities, and scale-up of these measures across other facilities might lead to a reduction in TB transmission in Nigeria and globally.

  3. Building and Strengthening Infection Control Strategies to Prevent Tuberculosis - Nigeria, 2015.

    PubMed

    Dokubo, E Kainne; Odume, Bethrand; Lipke, Virginia; Muianga, Custodio; Onu, Eugene; Olutola, Ayodotun; Ukachukwu, Lucy; Igweike, Patricia; Chukwura, Nneka; Ubochioma, Emperor; Aniaku, Everistus; Ezeudu, Chinyere; Agboeze, Joseph; Iroh, Gabriel; Orji, Elvina; Godwin, Okezue; Raji, Hasiya Bello; Aboje, S A; Osakwe, Chijioke; Debem, Henry; Bello, Mustapha; Onotu, Dennis; Maloney, Susan

    2016-03-18

    Tuberculosis (TB) is the leading cause of infectious disease mortality worldwide, accounting for more than 1.5 million deaths in 2014, and is the leading cause of death among persons living with human immunodeficiency virus (HIV) infection (1). Nigeria has the fourth highest annual number of TB cases among countries, with an estimated incidence of 322 per 100,000 population (1), and the second highest prevalence of HIV infection, with 3.4 million infected persons (2). In 2014, 100,000 incident TB cases and 78,000 TB deaths occurred among persons living with HIV infection in Nigeria (1). Nosocomial transmission is a significant source of TB infection in resource-limited settings (3), and persons with HIV infection and health care workers are at increased risk for TB infection because of their routine exposure to patients with TB in health care facilities (3-5). A lack of TB infection control in health care settings has resulted in outbreaks of TB and drug-resistant TB among patients and health care workers, leading to excess morbidity and mortality. In March 2015, in collaboration with the Nigeria Ministry of Health (MoH), CDC implemented a pilot initiative, aimed at increasing health care worker knowledge about TB infection control, assessing infection control measures in health facilities, and developing plans to address identified gaps. The approach resulted in substantial improvements in TB infection control practices at seven selected facilities, and scale-up of these measures across other facilities might lead to a reduction in TB transmission in Nigeria and globally. PMID:26985766

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

    PubMed

    Guo, Baozhu; Fedorova, Natalie D; Chen, Xiaoping; Wan, Chun-Hua; Wang, Wei; Nierman, William C; Bhatnagar, Deepak; Yu, Jiujiang

    2011-07-01

    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 resistant to fungal infection and/or aflatoxin production. To identify peanut Aspergillus-interactive and peanut Aspergillus-resistance genes, we carried out a large scale peanut Expressed Sequence Tag (EST) project which we used to construct a peanut glass slide oligonucleotide microarray. The fabricated microarray represents over 40% of the protein coding genes in the peanut genome. For expression profiling, resistant and susceptible peanut cultivars were infected with a mixture of Aspergillusflavus and parasiticus spores. The subsequent microarray analysis identified 62 genes in resistant cultivars that were up-expressed in response to Aspergillus infection. In addition, we identified 22 putative Aspergillus-resistance genes that were constitutively up-expressed in the resistant cultivar in comparison to the susceptible cultivar. Some of these genes were homologous to peanut, corn, and soybean genes that were previously shown to confer resistance to fungal infection. This study is a first step towards a comprehensive genome-scale platform for developing Aspergillus-resistant peanut cultivars through targeted marker-assisted breeding and genetic engineering. PMID:22069737

  5. A Cluster-Randomized Trial of Two Strategies to Improve Antibiotic Use for Patients with a Complicated Urinary Tract Infection

    PubMed Central

    Spoorenberg, Veroniek; Hulscher, Marlies E. J. L.; Geskus, Ronald B.; de Reijke, Theo M.; Opmeer, Brent C.; Prins, Jan M.; Geerlings, Suzanne E.

    2015-01-01

    Background Up to 50% of hospital antibiotic use is inappropriate and therefore improvement strategies are urgently needed. We compared the effectiveness of two strategies to improve the quality of antibiotic use in patients with a complicated urinary tract infection (UTI). Methods In a multicentre, cluster-randomized trial 19 Dutch hospitals (departments Internal Medicine and Urology) were allocated to either a multi-faceted strategy including feedback, educational sessions, reminders and additional/optional improvement actions, or a competitive feedback strategy, i.e. providing professionals with non-anonymous comparative feedback on the department’s appropriateness of antibiotic use. Retrospective baseline- and post-intervention measurements were performed in 2009 and 2012 in 50 patients per department, resulting in 1,964 and 2,027 patients respectively. Principal outcome measures were nine validated guideline-based quality indicators (QIs) that define appropriate antibiotic use in patients with a complicated UTI, and a QI sumscore that summarizes for each patient the appropriateness of antibiotic use. Results Performance scores on several individual QIs showed improvement from baseline to post-intervention measurements, but no significant differences were found between both strategies. The mean patient’s QI sum score improved significantly in both strategy groups (multi-faceted: 61.7% to 65.0%, P = 0.04 and competitive feedback: 62.8% to 66.7%, P = 0.01). Compliance with the strategies was suboptimal, but better compliance was associated with more improvement. Conclusion The effectiveness of both strategies was comparable and better compliance with the strategies was associated with more improvement. To increase effectiveness, improvement activities should be rigorously applied, preferably by a locally initiated multidisciplinary team. Trial Registration Nederlands Trial Register 1742 PMID:26637169

  6. 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

  7. Optimal Population-Level Infection Detection Strategies for Malaria Control and Elimination in a Spatial Model of Malaria Transmission.

    PubMed

    Gerardin, Jaline; Bever, Caitlin A; Hamainza, Busiku; Miller, John M; Eckhoff, Philip A; Wenger, Edward A

    2016-01-01

    Mass campaigns with antimalarial drugs are potentially a powerful tool for local elimination of malaria, yet current diagnostic technologies are insufficiently sensitive to identify all individuals who harbor infections. At the same time, overtreatment of uninfected individuals increases the risk of accelerating emergence of drug resistance and losing community acceptance. Local heterogeneity in transmission intensity may allow campaign strategies that respond to index cases to successfully target subpatent infections while simultaneously limiting overtreatment. While selective targeting of hotspots of transmission has been proposed as a strategy for malaria control, such targeting has not been tested in the context of malaria elimination. Using household locations, demographics, and prevalence data from a survey of four health facility catchment areas in southern Zambia and an agent-based model of malaria transmission and immunity acquisition, a transmission intensity was fit to each household based on neighborhood age-dependent malaria prevalence. A set of individual infection trajectories was constructed for every household in each catchment area, accounting for heterogeneous exposure and immunity. Various campaign strategies-mass drug administration, mass screen and treat, focal mass drug administration, snowball reactive case detection, pooled sampling, and a hypothetical serological diagnostic-were simulated and evaluated for performance at finding infections, minimizing overtreatment, reducing clinical case counts, and interrupting transmission. For malaria control, presumptive treatment leads to substantial overtreatment without additional morbidity reduction under all but the highest transmission conditions. Compared with untargeted approaches, selective targeting of hotspots with drug campaigns is an ineffective tool for elimination due to limited sensitivity of available field diagnostics. Serological diagnosis is potentially an effective tool for

  8. Optimal Population-Level Infection Detection Strategies for Malaria Control and Elimination in a Spatial Model of Malaria Transmission.

    PubMed

    Gerardin, Jaline; Bever, Caitlin A; Hamainza, Busiku; Miller, John M; Eckhoff, Philip A; Wenger, Edward A

    2016-01-01

    Mass campaigns with antimalarial drugs are potentially a powerful tool for local elimination of malaria, yet current diagnostic technologies are insufficiently sensitive to identify all individuals who harbor infections. At the same time, overtreatment of uninfected individuals increases the risk of accelerating emergence of drug resistance and losing community acceptance. Local heterogeneity in transmission intensity may allow campaign strategies that respond to index cases to successfully target subpatent infections while simultaneously limiting overtreatment. While selective targeting of hotspots of transmission has been proposed as a strategy for malaria control, such targeting has not been tested in the context of malaria elimination. Using household locations, demographics, and prevalence data from a survey of four health facility catchment areas in southern Zambia and an agent-based model of malaria transmission and immunity acquisition, a transmission intensity was fit to each household based on neighborhood age-dependent malaria prevalence. A set of individual infection trajectories was constructed for every household in each catchment area, accounting for heterogeneous exposure and immunity. Various campaign strategies-mass drug administration, mass screen and treat, focal mass drug administration, snowball reactive case detection, pooled sampling, and a hypothetical serological diagnostic-were simulated and evaluated for performance at finding infections, minimizing overtreatment, reducing clinical case counts, and interrupting transmission. For malaria control, presumptive treatment leads to substantial overtreatment without additional morbidity reduction under all but the highest transmission conditions. Compared with untargeted approaches, selective targeting of hotspots with drug campaigns is an ineffective tool for elimination due to limited sensitivity of available field diagnostics. Serological diagnosis is potentially an effective tool for

  9. Contrasting strategies used by lichen microalgae to cope with desiccation-rehydration stress revealed by metabolite profiling and cell wall analysis.

    PubMed

    Centeno, Danilo C; Hell, Aline F; Braga, Marcia R; Del Campo, Eva M; Casano, Leonardo M

    2016-05-01

    Most lichens in general, and their phycobionts in particular, are desiccation tolerant, but their mechanisms of desiccation tolerance (DT) remain obscure. The physiological responses and cell wall features of two putatively contrasting lichen-forming microalgae, Trebouxia sp. TR9 (TR9), isolated from Ramalina farinacea (adapted to frequent desiccation-rehydration cycles), and Coccomyxa solorina-saccatae (Csol), obtained from Solorina saccata (growing in usually humid limestone crevices, subjected to seasonal dry periods) was characterized. Microalgal cultures were desiccated under 25%-30% RH and then rehydrated. Under these conditions, RWC and ψw decreased faster and simultaneously during dehydration in Csol, whereas TR9 maintained its ψw until 70% RWC. The metabolic profile indicated that polyols played a key role in DT of both microalgae. However, TR9 constitutively accumulated higher amounts of polyols, whereas Csol induced the polyol synthesis under desiccation-rehydration. Csol also accumulated ascorbic acid, while TR9 synthesized protective raffinose-family oligosaccharides (RFOs) and increased its content of phenolics. Additionally, TR9 exhibited thicker and qualitatively different cell wall and extracellular polymeric layer compared with Csol, indicating higher water retention capability. The findings were consistent with the notion that lichen microalgae would have evolved distinct strategies to cope with desiccation-rehydration stress in correspondence with the water regime of their respective habitats. PMID:26914009

  10. Strategies for prevention of health care-associated infections in the NICU.

    PubMed

    Polin, Richard A; Denson, Susan; Brady, Michael T

    2012-04-01

    Health care-associated infections in the NICU result in increased morbidity and mortality, prolonged lengths of stay, and increased medical costs. Neonates are at high risk of acquiring health care-associated infections because of impaired host-defense mechanisms, limited amounts of protective endogenous flora on skin and mucosal surfaces at time of birth, reduced barrier function of their skin, use of invasive procedures and devices, and frequent exposure to broad-spectrum antibiotic agents. This clinical report reviews management and prevention of health care-associated infections in newborn infants.

  11. 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…

  12. Therapeutic Strategies and New Intervention Points in Chronic Hepatitis Delta Virus Infection

    PubMed Central

    Guo, Zhimin; King, Thomas

    2015-01-01

    Chronic hepatitis delta virus infection (CHD) is a condition arising from super-infection of hepatitis B virus (HBV)-infected patients, resulting in a more rapid advance in liver pathology and hepatocellular carcinoma than is observed for HBV mono-infection. Although hepatitis delta virus (HDV) is structurally simple, its life cycle involves the complex participation of host enzymes, HBV-derived surface antigen (HBsAg), and HDV-auto-ribozyme and hepatitis delta antigen (HDAg) activities. Unsatisfactory clinical trial results with interferon-based therapies are motivating researchers to adjust and redirect the approach to CHD drug development. This new effort will likely require additional structural and functional studies of the viral and cellular/host components involved in the HDV replication cycle. This review highlights recent work aimed at new drug interventions for CHD, with interpretation of key pre-clinical- and clinical trial outcomes and a discussion of promising new technological approaches to antiviral drug design. PMID:26295228

  13. 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

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

    PubMed

    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

  15. 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

  16. [Competitive karate and the risk of HIV infection--review, risk analysis and risk minimizing strategies].

    PubMed

    Müller-Rath, R; Mumme, T; Miltner, O; Skobel, E

    2004-03-01

    Bleeding facial injuries are not uncommon in competitive karate. Nevertheless, the risk of an infection with HIV is extremely low. Guidelines about the prevention of HIV infections are presented. Especially in contact sports and martial arts the athletes, judges and staff have to recognize and employ these recommendations. Bleeding wounds of the hands due to contact with the opponents teeth can be minimized by fist padding.

  17. [The confusing diversity of IgM tests in the diagnosis of Toxoplasma infections: efforts towards an optimal strategy].

    PubMed

    Auer, Herbert; Vander-Möse, Angelika; Aspöck, Horst

    2003-01-01

    IgM antibodies are indicative for a recent infection, thus the detection of this isotype is of essential significance particularly in the diagnosis of infections with Toxoplasma gondii during pregnancy (primary infection, seroconversion). Numerous serological tests and test kits (e.g. indirect immunofluorescent assay/IFAT, enzyme-linked immunosorbent assay/ELISA, Immunosorbent agglutination assay/ISAGA, Westernblot/WB) using different antigens and antigen preparations are provided by numerous companies. The sensitivities of such tests, however, variy considerably: The serological test results of four pregnant women with seroconversions and of three newborns from mothers with seroconversions are presented: VIDAS M and ISAGA M from one company yielded false negative results in three pregnant women whereas ISAGA M from another company could detect specific IgM. However, examination of the cord blood of the three newborns unanimously revealed IgM-negative results. Thus, our diagnostic strategy for pregnant women includes IIFT (or SFT) as basic test and ISAGA M (Toxotool I from Innogenetics) as well as IgG avidity test as additional tests; the serological diagnosis of suspected congenital infection comprises IFAT (or SFT), ISAGA M (from Innogenetics) and IgM/IgG Westernblot.

  18. Association of genotypes with infection types and antifungal susceptibilities in Candida albicans as revealed by recent molecular typing strategies

    PubMed Central

    Bai, Feng-Yan

    2014-01-01

    Candida albicans is a commensal microorganism in the mucosa of healthy individuals, but is also the most common opportunistic fungal pathogen of humans. It causes from benign infections such as oral and vaginal candidiasis to fatal, systematic diseases in immunocompromised or critically ill patients. In addition to improved therapy, the rapid and accurate identification of the disease-causing strains is crucial for diagnosis, clinical treatment and epidemiological studies of candidiasis. A variety of methods for strain typing of C. albicans have been developed. The most commonly used methods with the focus on recently developed molecular typing or DNA-fingerprinting strategies and the recent findings in the association of specific and genetically similar genotypes with certain infection types and the correlation between azole susceptibilities and certain genotypes of C. albicans from China are reviewed. PMID:24772369

  19. 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

  20. Optimal Population-Level Infection Detection Strategies for Malaria Control and Elimination in a Spatial Model of Malaria Transmission

    PubMed Central

    Gerardin, Jaline; Bever, Caitlin A.; Hamainza, Busiku; Miller, John M.; Eckhoff, Philip A.; Wenger, Edward A.

    2016-01-01

    Mass campaigns with antimalarial drugs are potentially a powerful tool for local elimination of malaria, yet current diagnostic technologies are insufficiently sensitive to identify all individuals who harbor infections. At the same time, overtreatment of uninfected individuals increases the risk of accelerating emergence of drug resistance and losing community acceptance. Local heterogeneity in transmission intensity may allow campaign strategies that respond to index cases to successfully target subpatent infections while simultaneously limiting overtreatment. While selective targeting of hotspots of transmission has been proposed as a strategy for malaria control, such targeting has not been tested in the context of malaria elimination. Using household locations, demographics, and prevalence data from a survey of four health facility catchment areas in southern Zambia and an agent-based model of malaria transmission and immunity acquisition, a transmission intensity was fit to each household based on neighborhood age-dependent malaria prevalence. A set of individual infection trajectories was constructed for every household in each catchment area, accounting for heterogeneous exposure and immunity. Various campaign strategies—mass drug administration, mass screen and treat, focal mass drug administration, snowball reactive case detection, pooled sampling, and a hypothetical serological diagnostic—were simulated and evaluated for performance at finding infections, minimizing overtreatment, reducing clinical case counts, and interrupting transmission. For malaria control, presumptive treatment leads to substantial overtreatment without additional morbidity reduction under all but the highest transmission conditions. Compared with untargeted approaches, selective targeting of hotspots with drug campaigns is an ineffective tool for elimination due to limited sensitivity of available field diagnostics. Serological diagnosis is potentially an effective tool for

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

    PubMed

    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

  3. Contrast Materials

    MedlinePlus

    ... or other reactions to contrast materials are rare, radiology departments are well-equipped to deal with them. ... is given. However, both the American College of Radiology (ACR) and the European Society of Urogenital Radiology ...

  4. Protecting Our Front-liners: Occupational Tuberculosis Prevention Through Infection Control Strategies.

    PubMed

    Verkuijl, Sabine; Middelkoop, Keren

    2016-05-15

    Healthcare workers (HCWs) in low- and middle-income countries with high tuberculosis prevalence are at increased risk of tuberculosis infection; however, tuberculosis infection control (TBIC) measures are often poorly implemented. The World Health Organization recommends 4 levels of TBIC: managerial (establishment and oversight of TBIC policies), administrative controls (reducing HCWs' exposure to tuberculosis), environmental controls (reducing the concentration of infectious respiratory aerosols in the air), and personal respiratory protection. This article will discuss each of these levels of TBIC, and review the available data on the implementation of each in sub-Saharan African countries. In addition, we review the attitudes and motivation of HCWs regarding TBIC measures, and the impact of stigma on infection control practices and implementation. After summarizing the challenges facing effective TBIC implementation, we will discuss possible solutions and recommendations. Last, we present a case study of how a clinic effectively addressed some of the challenges of TBIC implementation.

  5. Protecting Our Front-liners: Occupational Tuberculosis Prevention Through Infection Control Strategies.

    PubMed

    Verkuijl, Sabine; Middelkoop, Keren

    2016-05-15

    Healthcare workers (HCWs) in low- and middle-income countries with high tuberculosis prevalence are at increased risk of tuberculosis infection; however, tuberculosis infection control (TBIC) measures are often poorly implemented. The World Health Organization recommends 4 levels of TBIC: managerial (establishment and oversight of TBIC policies), administrative controls (reducing HCWs' exposure to tuberculosis), environmental controls (reducing the concentration of infectious respiratory aerosols in the air), and personal respiratory protection. This article will discuss each of these levels of TBIC, and review the available data on the implementation of each in sub-Saharan African countries. In addition, we review the attitudes and motivation of HCWs regarding TBIC measures, and the impact of stigma on infection control practices and implementation. After summarizing the challenges facing effective TBIC implementation, we will discuss possible solutions and recommendations. Last, we present a case study of how a clinic effectively addressed some of the challenges of TBIC implementation. PMID:27118852

  6. Managing self-limiting respiratory tract infections: a qualitative study of the usefulness of the delayed prescribing strategy

    PubMed Central

    Peters, Sarah; Rowbotham, Samantha; Chisholm, Anna; Wearden, Alison; Moschogianis, Susie; Cordingley, Lis; Baker, David; Hyde, Catherine; Chew-Graham, Carolyn

    2011-01-01

    Background Despite respiratory tract infections usually being viral and self-limiting, most primary care consultations still result in an antibiotic prescription. The National Institute for Health and Clinical Excellence (NICE) introduced the ‘delayed prescribing’ (DP) strategy. It remains unknown how useful UK clinicians find this approach Aim To investigate how DP is used within UK primary care, and the benefits and challenges associated with this strategy Design and setting Qualitative interview and focus group study in UK scheduled and unscheduled care primary care settings Method Data were gathered through semi-structured interviews (n = 49) and six focus groups with GPs, trainee GPs, and nurse prescribers (NPs). An iterative analysis approach, using grounded theory principles, was used to generate themes from the dataset. Results Prescribers were familiarwith DP but used it infrequently. DP was often used to manage diagnostic uncertainty, although NPs, trainee GPs, and GPs working in unscheduled care services preferred patients to reconsult under these circumstances. Prescribers used DP to avoid conflict, although some had found more effective strategies to achieve this. Prescribers were generally uncomfortable giving clinical responsibility to patients, and DP was perceived to communicate a conflicting message to patients about antibiotic efficacy. Conclusion DP was not considered to be a helpful strategy for managing patients with self-limiting respiratory tract infections within primary care and the findings do not support the centrality of DP in NICE guidelines as a primary means of reducing antibiotic prescribing. Future training and guidelines should encourage alternative ways of communicating empathy, addressing patient beliefs, and encouraging self-management. PMID:22152745

  7. Treating periprosthetic joint infections as biofilms: key diagnosis and management strategies.

    PubMed

    Tzeng, Alice; Tzeng, Tony H; Vasdev, Sonia; Korth, Kyle; Healey, Travis; Parvizi, Javad; Saleh, Khaled J

    2015-03-01

    Considerable evidence suggests that microbial biofilms play an important role in periprosthetic joint infection (PJI) pathogenesis. Compared to free-floating planktonic bacteria, biofilm bacteria are more difficult to culture and possess additional immune-evasive and antibiotic resistance mechanisms, making infections harder to detect and eradicate. This article reviews cutting-edge advances in biofilm-associated infection diagnosis and treatment in the context of current PJI guidelines and highlights emerging technologies that may improve the efficacy and reduce costs associated with PJI. Promising PJI diagnostic tools include culture-independent methods based on sequence comparisons of the bacterial 16S ribosomal RNA gene, which offer higher throughput and greater sensitivity than culture-based methods. For therapy, novel methods based on disrupting biofilm-specific properties include quorum quenchers, bacteriophages, and ultrasound/electrotherapy. Since biofilm infections are not easily detected or treated by conventional approaches, molecular diagnostic techniques and next-generation antibiofilm treatments should be integrated into PJI clinical practice guidelines in the near future. PMID:25586931

  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. 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

  10. New Perspectives on the Use of Phytochemicals as an Emergent Strategy to Control Bacterial Infections Including Biofilms.

    PubMed

    Borges, Anabela; Abreu, Ana Cristina; Dias, Carla; Saavedra, Maria José; Borges, Fernanda; Simões, Manuel

    2016-01-01

    The majority of current infectious diseases are almost untreatable by conventional antibiotic therapy given the advent of multidrug-resistant bacteria. The degree of severity and the persistence of infections are worsened when microorganisms form biofilms. Therefore, efforts are being applied to develop new drugs not as vulnerable as the current ones to bacterial resistance mechanisms, and also able to target bacteria in biofilms. Natural products, especially those obtained from plants, have proven to be outstanding compounds with unique properties, making them perfect candidates for these much-needed therapeutics. This review presents the current knowledge on the potentialities of plant products as antibiotic adjuvants to restore the therapeutic activity of drugs. Further, the difficulties associated with the use of the existing antibiotics in the treatment of biofilm-related infections are described. To counteract the biofilm resistance problems, innovative strategies are suggested based on literature data. Among the proposed strategies, the use of phytochemicals to inhibit or eradicate biofilms is highlighted. An overview on the use of phytochemicals to interfere with bacterial quorum sensing (QS) signaling pathways and underlying phenotypes is provided. The use of phytochemicals as chelating agents and efflux pump inhibitors is also reviewed.

  11. New Perspectives on the Use of Phytochemicals as an Emergent Strategy to Control Bacterial Infections Including Biofilms.

    PubMed

    Borges, Anabela; Abreu, Ana Cristina; Dias, Carla; Saavedra, Maria José; Borges, Fernanda; Simões, Manuel

    2016-01-01

    The majority of current infectious diseases are almost untreatable by conventional antibiotic therapy given the advent of multidrug-resistant bacteria. The degree of severity and the persistence of infections are worsened when microorganisms form biofilms. Therefore, efforts are being applied to develop new drugs not as vulnerable as the current ones to bacterial resistance mechanisms, and also able to target bacteria in biofilms. Natural products, especially those obtained from plants, have proven to be outstanding compounds with unique properties, making them perfect candidates for these much-needed therapeutics. This review presents the current knowledge on the potentialities of plant products as antibiotic adjuvants to restore the therapeutic activity of drugs. Further, the difficulties associated with the use of the existing antibiotics in the treatment of biofilm-related infections are described. To counteract the biofilm resistance problems, innovative strategies are suggested based on literature data. Among the proposed strategies, the use of phytochemicals to inhibit or eradicate biofilms is highlighted. An overview on the use of phytochemicals to interfere with bacterial quorum sensing (QS) signaling pathways and underlying phenotypes is provided. The use of phytochemicals as chelating agents and efflux pump inhibitors is also reviewed. PMID:27399652

  12. Bundled strategies against infection after liver transplantation: Lessons from multidrug-resistant Pseudomonas aeruginosa.

    PubMed

    Sato, Asahi; Kaido, Toshimi; Iida, Taku; Yagi, Shintaro; Hata, Koichiro; Okajima, Hideaki; Takakura, Shunji; Ichiyama, Satoshi; Uemoto, Shinji

    2016-04-01

    Infection is a life-threatening complication after liver transplantation (LT). A recent outbreak of multidrug-resistant Pseudomonas aeruginosa triggered changes in our infection control measures. This study investigated the usefulness of our bundled interventions against postoperative infection after LT. This before-and-after analysis enrolled 130 patients who underwent living donor or deceased donor LT between January 2011 and October 2014. We initiated 3 measures after January 2013: (1) we required LT candidates to be able to walk independently; (2) we increased the hand hygiene compliance rate and contact precautions; and (3) we introduced procalcitonin (PCT) measurement for a more precise determination of empirical antimicrobial treatment. We compared factors affecting the emergence of drug-resistant microorganisms, such as the duration of antimicrobial and carbapenem therapy and hospital stay, and outcomes such as bacteremia and death from infection between before (n = 77) and after (n = 53) the LT suspension period. The utility of PCT measurement was also evaluated. Patients' backgrounds were not significantly different before and after the protocol revision. Incidence of bacteremia (44% versus 25%; P = 0.02), detection rate of multiple bacteria (18% versus 4%; P = 0.01), and deaths from infections (12% versus 2%; P =  0.04) significantly decreased after the protocol revision. Duration of antibiotic (42.3 versus 25.1 days; P =  0.002) and carbapenem administration (15.1 versus 5.2 days; P < 0.001) and the length of postoperative hospital stay (85.4 versus 63.5 days; P =  0.048) also decreased after the protocol revision. PCT mean values were significantly higher in the bacteremia group (10.10 ng/mL), compared with the uneventful group (0.65 ng/mL; P =  0.002) and rejection group (2.30 ng/mL; P =  0.02). One-year overall survival after LT significantly increased in the latter period (71% versus 94%; P =  0

  13. Bundled strategies against infection after liver transplantation: Lessons from multidrug-resistant Pseudomonas aeruginosa.

    PubMed

    Sato, Asahi; Kaido, Toshimi; Iida, Taku; Yagi, Shintaro; Hata, Koichiro; Okajima, Hideaki; Takakura, Shunji; Ichiyama, Satoshi; Uemoto, Shinji

    2016-04-01

    Infection is a life-threatening complication after liver transplantation (LT). A recent outbreak of multidrug-resistant Pseudomonas aeruginosa triggered changes in our infection control measures. This study investigated the usefulness of our bundled interventions against postoperative infection after LT. This before-and-after analysis enrolled 130 patients who underwent living donor or deceased donor LT between January 2011 and October 2014. We initiated 3 measures after January 2013: (1) we required LT candidates to be able to walk independently; (2) we increased the hand hygiene compliance rate and contact precautions; and (3) we introduced procalcitonin (PCT) measurement for a more precise determination of empirical antimicrobial treatment. We compared factors affecting the emergence of drug-resistant microorganisms, such as the duration of antimicrobial and carbapenem therapy and hospital stay, and outcomes such as bacteremia and death from infection between before (n = 77) and after (n = 53) the LT suspension period. The utility of PCT measurement was also evaluated. Patients' backgrounds were not significantly different before and after the protocol revision. Incidence of bacteremia (44% versus 25%; P = 0.02), detection rate of multiple bacteria (18% versus 4%; P = 0.01), and deaths from infections (12% versus 2%; P =  0.04) significantly decreased after the protocol revision. Duration of antibiotic (42.3 versus 25.1 days; P =  0.002) and carbapenem administration (15.1 versus 5.2 days; P < 0.001) and the length of postoperative hospital stay (85.4 versus 63.5 days; P =  0.048) also decreased after the protocol revision. PCT mean values were significantly higher in the bacteremia group (10.10 ng/mL), compared with the uneventful group (0.65 ng/mL; P =  0.002) and rejection group (2.30 ng/mL; P =  0.02). One-year overall survival after LT significantly increased in the latter period (71% versus 94%; P =  0

  14. Isotype Diversification of IgG Antibodies to HIV Gag Proteins as a Therapeutic Vaccination Strategy for HIV Infection.

    PubMed

    French, Martyn A; Abudulai, Laila N; Fernandez, Sonia

    2013-01-01

    The development of vaccines to treat and prevent human immunodeficiency virus (HIV) infection has been hampered by an incomplete understanding of "protective" immune responses against HIV. Natural control of HIV-1 infection is associated with T-cell responses against HIV-1 Gag proteins, particularly CD8⁺ T-cell responses restricted by "protective" HLA-B alleles, but other immune responses also contribute to immune control. These immune responses appear to include IgG antibodies to HIV-1 Gag proteins, interferon-a-dependant natural killer (NK) cell responses and plasmacytoid dendritic cell (pDC) responses. Here, it is proposed that isotype diversification of IgG antibodies against HIV-1 Gag proteins, to include IgG2, as well as IgG3 and IgG1 antibodies, will broaden the function of the antibody response and facilitate accessory cell responses against HIV-1 by NK cells and pDCs. We suggest that this should be investigated as a vaccination strategy for HIV-1 infection.

  15. 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

  16. 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.

  17. The Serostatus Approach to Fighting the HIV Epidemic: prevention strategies for infected individuals.

    PubMed Central

    Janssen, R S; Holtgrave, D R; Valdiserri, R O; Shepherd, M; Gayle, H D; De Cock, K M

    2001-01-01

    In the United States, HIV prevention programs have historically tailored activities for specific groups primarily on the basis of behavioral risk factors and demographic characteristics. Through the Serostatus Approach to Fighting the Epidemic (SAFE), the Centers for Disease Control and Prevention is now expanding prevention programs, especially for individuals with HIV, to reduce the risk of transmission as a supplement to current programs that primarily focus on reducing the risk of acquisition of the virus. For individuals with HIV, SAFE comprises action steps that focus on diagnosing all HIV-infected persons, linking them to appropriate high-quality care and prevention services, helping them adhere to treatment regimens, and supporting them in adopting and sustaining HIV risk reduction behavior. SAFE couple a traditional infectious disease control focus on the infected person with behavioral interventions that have been standard for HIV prevention programs. PMID:11441723

  18. 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.

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

    PubMed

    Karachalios, Theofilos; Koutalos, Antonios; Komnos, George

    2014-01-01

    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.

  20. 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.

  1. Strategies to manage hepatitis C virus infection disease burden - volume 3.

    PubMed

    Alfaleh, F Z; Nugrahini, N; Matičič, M; Tolmane, I; Alzaabi, M; Hajarizadeh, B; Valantinas, J; Kim, D Y; Hunyady, B; Abaalkhail, F; Abbas, Z; Abdou, A; Abourached, A; Al Braiki, F; Al Hosani, F; Al Jaberi, K; Al Khatry, M; Al Mulla, M A; Al Quraishi, H; Al Rifai, A; Al Serkal, Y; Alam, A; Alashgar, H I; Alavian, S M; Alawadhi, S; Al-Dabal, L; Aldins, P; Alghamdi, A S; Al-Hakeem, R; Aljumah, A A; Almessabi, A; Alqutub, A N; Alswat, K A; Altraif, I; Andrea, N; Assiri, A M; Babatin, M A; Baqir, A; Barakat, M T; Bergmann, O M; Bizri, A R; Chaudhry, A; Choi, M S; Diab, T; Djauzi, S; El Hassan, E S; El Khoury, S; Estes, C; Fakhry, S; Farooqi, J I; Fridjonsdottir, H; Gani, R A; Ghafoor Khan, A; Gheorghe, L; Goldis, A; Gottfredsson, M; Gregorcic, S; Gunter, J; Hamid, S; Han, K H; Hasan, I; Hashim, A; Horvath, G; Husni, R; Jafri, W; Jeruma, A; Jonasson, J G; Karlsdottir, B; Kim, Y S; Koutoubi, Z; Lesmana, L A; Liakina, V; Lim, Y S; Löve, A; Maimets, M; Makara, M; Malekzadeh, R; Memon, M S; Merat, S; Mokhbat, J E; Mourad, F H; Muljono, D H; Nawaz, A; Olafsson, S; Priohutomo, S; Qureshi, H; Rassam, P; Razavi, H; Razavi-Shearer, D; Razavi-Shearer, K; Rozentale, B; Sadik, M; Saeed, K; Salamat, A; Salupere, R; Sanai, F M; Sanityoso Sulaiman, A; Sayegh, R A; Schmelzer, J D; Sharara, A I; Sibley, A; Siddiq, M; Siddiqui, A M; Sigmundsdottir, G; Sigurdardottir, B; Speiciene, D; Sulaiman, A; Sultan, M A; Taha, M; Tanaka, J; Tarifi, H; Tayyab, G; Ud Din, M; Umar, M; Videčnik-Zorman, J; Yaghi, C; Yunihastuti, E; Yusuf, M A; Zuberi, B F; Blach, S

    2015-12-01

    The hepatitis C virus (HCV) epidemic was forecasted through 2030 for 15 countries in Europe, the Middle East and Asia, and the relative impact of two scenarios was considered: increased treatment efficacy while holding the annual number of treated patients constant and increased treatment efficacy and an increased annual number of treated patients. Increasing levels of diagnosis and treatment, in combination with improved treatment efficacy, were critical for achieving substantial reductions in disease burden. A 90% reduction in total HCV infections within 15 years is feasible in most countries studied, but it required a coordinated effort to introduce harm reduction programmes to reduce new infections, screening to identify those already infected and treatment with high cure rate therapies. This suggests that increased capacity for screening and treatment will be critical in many countries. Birth cohort screening is a helpful tool for maximizing resources. Among European countries, the majority of patients were born between 1940 and 1985. A wider range of birth cohorts was seen in the Middle East and Asia (between 1925 and 1995). PMID:26513447

  2. Strategies for treating chronic HCV infection in patients with cirrhosis: latest evidence and clinical outcomes

    PubMed Central

    Wilder, Julius M.; Muir, Andrew J.

    2015-01-01

    The burden of chronic hepatitis C virus (HCV) infection is significant and growing. HCV is considered one of the leading causes of liver disease worldwide and the leading cause of liver transplantation globally. While those infected is estimated in the hundreds of millions, this is likely an underestimation because of the indolent nature of this disease when first contracted. Approximately 20% of patients with HCV infection will progress to advanced fibrosis and cirrhosis. Those that do are at risk of decompensated liver disease including GI bleeding, encephalopathy, severe lab abnormalities, and hepatocellular carcinoma. Those individuals with advanced fibrosis and cirrhosis have historically been difficult to treat. The backbone of previous HCV regimens was interferon (IFN). The outcomes for IFN based regimens were poor and resulted in increased adverse events among those with advanced fibrosis and cirrhosis. Now, in the era of new direct acting antiviral (DAA’s) medications, there is hope for curing chronic HCV in everyone, including those with advanced fibrosis and cirrhosis. This article provides a review on the most up to date data on the use of DAA’s in patients with advanced fibrosis and cirrhosis. We are at a point where HCV could be truly eradicated, but to do so will require ensuring there are effective and safe treatments for those with advanced fibrosis and cirrhosis. PMID:26568808

  3. 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

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

    PubMed

    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

    2016-08-11

    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

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

    PubMed

    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

  6. 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

  7. 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. PMID:25821611

  8. 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

  9. 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

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. A new therapeutic strategy for the eradication of Helicobacter pylori infection.

    PubMed

    Patiti, M; Longaroni, M; Stella, P; Tacchi, P

    1996-12-01

    For the eradication of the Helicobacter pylori infection, authors have tested 50 HP-positive subjects (28 females and 22 males; mean age 47 years): 21 duodenal ulcers and 29 gastritis. All patients received the following treatment: omeprazole 40 mg for 30 days, azithromycin 500 mg in a single daily dose for 3 days for 2 cycles and metronidazole 250 mgx4 for 14 days. One month after the end of therapy, patients have been controlled: the HP eradication rates have been 76% (35/46), duodenal ulcer was cured in 90% (18/20). No important side-effects were reported by patients during the treatment. In conclusion the new therapeutic scheme with azithromycin represents a semplificated alternative treatment in the eradication of Helicobacter pylori.

  15. 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

  16. Epidemiology of Mycoplasma pneumoniae Infections in Japan and Therapeutic Strategies for Macrolide-Resistant M. pneumoniae.

    PubMed

    Yamazaki, Tsutomu; Kenri, Tsuyoshi

    2016-01-01

    Pneumonia caused by Mycoplasma pneumoniae (M. pneumoniae pneumonia) is a major cause of community-acquired pneumonia worldwide. The surveillance of M. pneumoniae pneumonia is important for etiological and epidemiological studies of acute respiratory infections. In Japan, nation-wide surveillance of M. pneumoniae pneumonia has been conducted as a part of the National Epidemiological Surveillance of Infectious Diseases (NESID) program. This surveillance started in 1981, and significant increases in the numbers of M. pneumoniae pneumonia patients were noted in 1984, 1988, 2006, 2010, 2011, 2012, and 2015. The epidemics in 2011 and 2012 were particularly widespread and motivated researchers to conduct detailed epidemiological studies, including genotyping and drug resistance analyses of M. pneumoniae isolates. The genotyping studies based on the p1 gene sequence suggested that the p1 gene type 1 lineage has been dominant in Japan since 2003, including the epidemic period during 2011-2012. However, more detailed p1 typing analysis is required to determine whether the type 2 lineages become more relevant after the dominance of the type 1 lineage. There has been extensive research interest in implications of the p1 gene types on the epidemiology of M. pneumoniae infections. Serological characterizations of sera from patients have provided a glimpse into these associations, showing the presence of type specific antibody in the patient sera. Another important epidemiological issue of M. pneumoniae pneumonia is the emergence of macrolide-resistant M. pneumoniae (MRMP). MRMPs were noted among clinical isolates in Japan after 2000. At present, the isolation rate of MRMPs from pediatric patients is estimated at 50-90% in Japan, depending on the specific location. In view of the situation, Japanese societies have issued guiding principles for treating M. pneumoniae pneumonia. In these guiding principles, macrolides are still recommended as the first-line drug, however, if the

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

    PubMed Central

    Zimba, Roderick F.; Likando, Gilbert N.

    2014-01-01

    Abstract 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. PMID:24814659

  18. 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. PMID:24814659

  19. Epidemiology of Mycoplasma pneumoniae Infections in Japan and Therapeutic Strategies for Macrolide-Resistant M. pneumoniae

    PubMed Central

    Yamazaki, Tsutomu; Kenri, Tsuyoshi

    2016-01-01

    Pneumonia caused by Mycoplasma pneumoniae (M. pneumoniae pneumonia) is a major cause of community-acquired pneumonia worldwide. The surveillance of M. pneumoniae pneumonia is important for etiological and epidemiological studies of acute respiratory infections. In Japan, nation-wide surveillance of M. pneumoniae pneumonia has been conducted as a part of the National Epidemiological Surveillance of Infectious Diseases (NESID) program. This surveillance started in 1981, and significant increases in the numbers of M. pneumoniae pneumonia patients were noted in 1984, 1988, 2006, 2010, 2011, 2012, and 2015. The epidemics in 2011 and 2012 were particularly widespread and motivated researchers to conduct detailed epidemiological studies, including genotyping and drug resistance analyses of M. pneumoniae isolates. The genotyping studies based on the p1 gene sequence suggested that the p1 gene type 1 lineage has been dominant in Japan since 2003, including the epidemic period during 2011–2012. However, more detailed p1 typing analysis is required to determine whether the type 2 lineages become more relevant after the dominance of the type 1 lineage. There has been extensive research interest in implications of the p1 gene types on the epidemiology of M. pneumoniae infections. Serological characterizations of sera from patients have provided a glimpse into these associations, showing the presence of type specific antibody in the patient sera. Another important epidemiological issue of M. pneumoniae pneumonia is the emergence of macrolide-resistant M. pneumoniae (MRMP). MRMPs were noted among clinical isolates in Japan after 2000. At present, the isolation rate of MRMPs from pediatric patients is estimated at 50–90% in Japan, depending on the specific location. In view of the situation, Japanese societies have issued guiding principles for treating M. pneumoniae pneumonia. In these guiding principles, macrolides are still recommended as the first-line drug, however, if

  20. 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.

  1. Modelling the potential benefits of different strategies to control infection with Trypanosoma evansi in camels in Somaliland.

    PubMed

    Salah, Abdirahman; Robertson, Ian; Mohamed, Abdullahi Sheikh

    2016-01-01

    Trypanosoma evansi (T. evansi), the protozoan parasitic cause of camel trypanosomosis (Surra), constitutes one of the major veterinary problems worldwide. An infectious disease model of camel trypanosomosis (Surra) was adopted from one developed for buffalo and applied to study the impact of T. evansi infection on camel production. The model contained deterministic and stochastic components and the seroprevalence based on a survey conducted in Somaliland in 2011 and 2012 to simulate and estimate the economic benefits of four different control options against T. evansi infection in camels (1, 2, 3 and 4 regimens). The mean benefit per animal of controlling surra was calculated at US$354 (the treatment of all camels biannually), US$426 (the monthly targeted treatment of clinically sick camels) and US$287 (biannual targeted treatment of seropositive camels), respectively, compared with US$137 for untreated camels. Consequently, the model predicted that the total net benefit loss to a camel herd or village that was not applying the recommended effective surra control strategy was US$115,605 (69.4 billion shilling per annum). PMID:26519146

  2. Modelling the potential benefits of different strategies to control infection with Trypanosoma evansi in camels in Somaliland.

    PubMed

    Salah, Abdirahman; Robertson, Ian; Mohamed, Abdullahi Sheikh

    2016-01-01

    Trypanosoma evansi (T. evansi), the protozoan parasitic cause of camel trypanosomosis (Surra), constitutes one of the major veterinary problems worldwide. An infectious disease model of camel trypanosomosis (Surra) was adopted from one developed for buffalo and applied to study the impact of T. evansi infection on camel production. The model contained deterministic and stochastic components and the seroprevalence based on a survey conducted in Somaliland in 2011 and 2012 to simulate and estimate the economic benefits of four different control options against T. evansi infection in camels (1, 2, 3 and 4 regimens). The mean benefit per animal of controlling surra was calculated at US$354 (the treatment of all camels biannually), US$426 (the monthly targeted treatment of clinically sick camels) and US$287 (biannual targeted treatment of seropositive camels), respectively, compared with US$137 for untreated camels. Consequently, the model predicted that the total net benefit loss to a camel herd or village that was not applying the recommended effective surra control strategy was US$115,605 (69.4 billion shilling per annum).

  3. A Comparison of Network-based Strategies for Screening At-Risk Hispanic/Latino Adolescents and Young Adults for Undiagnosed Asymptomatic HIV Infection

    PubMed Central

    Boyer, Cherrie B.; Robles-Schrader, Grisel M.; Li, Su X.; Miller, Robin L.; Korelitz, James; Price, Georgine N.; Rivera Torres, Carmen M.; Chutuape, Kate S.; Stines, Stephanie J.; Straub, Diane M.; Peralta, Ligia; Febo, Irma; Hightow-Weidman, Lisa; Gonin, René; Kapogiannis, Bill G.; Ellen, Jonathan M.

    2014-01-01

    Purpose Hispanic/Latino adolescents and young adults are disproportionately impacted by the HIV/AIDS epidemic; yet, little is known about the best strategies to increase HIV testing in this group. Network-based approaches are feasible and acceptable means for screening at-risk adults for HIV infection, but it is unknown whether these approaches are appropriate for at-risk young Hispanics/Latinos. Thus, we compared an alternative venue-based testing (AVT) strategy with a social and sexual network referral (SSNIT) strategy. Methods All participants were Hispanics/Latinos, aged 13–24 years with self-reported HIV risk; they were recruited from 11 cities in the U.S. and Puerto Rico, and completed an audio computer-assisted self-interview and underwent HIV screening. Results 1,596 participants (94.5% of those approached) were enrolled: 784 (49.1%) through AVT and 812 (50.9%) through SSNIT. HIV infection was identified in three SSNIT (0.37%) and four AVT (0.51%) participants (p=0.7213). Conclusions Despite high levels of HIV risk, a low prevalence of HIV infection was identified with no differences by recruitment strategy. We found overwhelming support for the acceptability and feasibility of AVT and SSNIT for engaging and screening at-risk young Hispanics/Latinos. Further research is needed to better understand how to strategically implement such strategies to improve identification of undiagnosed HIV infection. PMID:25223476

  4. NKp46 and DNAM-1 NK-cell receptors drive the response to human cytomegalovirus-infected myeloid dendritic cells overcoming viral immune evasion strategies.

    PubMed

    Magri, Giuliana; Muntasell, Aura; Romo, Neus; Sáez-Borderías, Andrea; Pende, Daniela; Geraghty, Daniel E; Hengel, Hartmut; Angulo, Ana; Moretta, Alessandro; López-Botet, Miguel

    2011-01-20

    Information on natural killer (NK)-cell receptor-ligand interactions involved in the response to human cytomegalovirus (HCMV) is limited and essentially based on the study of infected fibroblasts. Experimental conditions were set up to characterize the NK response to HCMV-infected myeloid dendritic cells (DCs). Monocyte-derived DCs (moDCs) infected by the TB40/E HCMV strain down-regulated the expression of human leukocyte antigen class I molecules and specifically activated autologous NK-cell populations. NKG2D ligands appeared virtually undetectable in infected moDCs, reflecting the efficiency of immune evasion mechanisms, and explained the lack of antagonistic effects of NKG2D-specific monoclonal antibody. By contrast, DNAM-1 and DNAM-1 ligands (DNAM-1L)-specific monoclonal antibodies inhibited the NK response at 48 hours after infection, although the impact of HCMV-dependent down-regulation of DNAM-1L in infected moDCs was perceived at later stages. moDCs constitutively expressed ligands for NKp46 and NKp30 natural cytotoxicity receptors, which were partially reduced on HCMV infection; yet, only NKp46 appeared involved in the NK response. In contrast to previous reports in fibroblasts, human leukocyte antigen-E expression was not preserved in HCMV-infected moDCs, which triggered CD94/NKG2A(+) NK-cell activation. The results provide an insight on key receptor-ligand interactions involved in the NK-cell response against HCMV-infected moDCs, stressing the importance of the dynamics of viral immune evasion mechanisms.

  5. 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 Central

    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. PMID:24155975

  6. 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

  7. 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

  8. 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.

  9. [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.

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

    PubMed

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

    2013-01-01

    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. PMID:24127037

  11. Interactions among Strategies Associated with Bacterial Infection: Pathogenicity, Epidemicity, and Antibiotic Resistance†

    PubMed Central

    Martínez, José L.; Baquero, Fernando

    2002-01-01

    Infections have been the major cause of disease throughout the history of human populations. With the introduction of antibiotics, it was thought that this problem should disappear. However, bacteria have been able to evolve to become antibiotic resistant. Nowadays, a proficient pathogen must be virulent, epidemic, and resistant to antibiotics. Analysis of the interplay among these features of bacterial populations is needed to predict the future of infectious diseases. In this regard, we have reviewed the genetic linkage of antibiotic resistance and bacterial virulence in the same genetic determinants as well as the cross talk between antibiotic resistance and virulence regulatory circuits with the aim of understanding the effect of acquisition of resistance on bacterial virulence. We also discuss the possibility that antibiotic resistance and bacterial virulence might prevail as linked phenotypes in the future. The novel situation brought about by the worldwide use of antibiotics is undoubtedly changing bacterial populations. These changes might alter the properties of not only bacterial pathogens, but also the normal host microbiota. The evolutionary consequences of the release of antibiotics into the environment are largely unknown, but most probably restoration of the microbiota from the preantibiotic era is beyond our current abilities. PMID:12364374

  12. 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.

  13. 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

  14. 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.

  15. A Screen-and-Treat Strategy Targeting Visceral Leishmaniasis in HIV-Infected Individuals in Endemic East African Countries: The Way Forward?

    PubMed Central

    van Griensven, Johan; Diro, Ermias; Lopez-Velez, Rogelio; Ritmeijer, Koert; Boelaert, Marleen; Zijlstra, Ed E.; Hailu, Asrat; Lynen, Lutgarde

    2014-01-01

    In the wake of the HIV epidemic, visceral leishmaniasis (VL), a disseminated protozoan infection caused by the Leishmania donovani complex, has been re-emerging, particularly in North Ethiopia where up to 40% of patients with VL are co-infected with HIV. Management of VL in HIV co-infection is complicated by increased drug toxicity, and high treatment failure and relapse rates with all currently available drugs, despite initiation of antiretroviral treatment. Tackling L. donovani infection before disease onset would thus be a logical approach. A screen-and-treat approach targeting latent or the early stage of infection has successfully been implemented in other HIV-associated opportunistic infections. While conceptually attractive in the context of VL–HIV, the basic understanding and evidence underpinning such an approach is currently lacking. Prospective cohort studies will have to be conducted to quantify the risk of VL in different risk groups and across CD4 cell count levels. This will allow developing clinical prognostic tools, integrating clinical, HIV and Leishmania infection markers. Interventional studies will be needed to evaluate prophylactic or pre-emptive treatment strategies for those at risk, ideally relying on an oral (combination) regimen. Issues like tolerability, emergence of resistance and drug interactions will require due attention. The need for maintenance therapy will have to be assessed. Based on the risk–benefit data, VL risk cut-offs will have to be identified to target treatment to those most likely to benefit. Such a strategy should be complemented with early initiation of antiretroviral treatment and other strategies to prevent HIV and Leishmania infection. PMID:25101627

  16. 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

  17. 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. PMID:25352630

  18. Strategies for reducing exposure to indoor air pollution from household burning of solid fuels: effects on acute lower respiratory infections in children under the age of 15 years

    PubMed Central

    Havens, Deborah; Jary, Hannah R; Patel, Latifa B; Chiume, Msandeni E; Mortimer, Kevin J

    2015-01-01

    This is the protocol for a review and there is no abstract. The objectives are as follows: This study aims to assess the effects of intervention strategies that reduce exposure to household air pollution from burning solid fuels on episodes of acute lower respiratory infection (ALRI) in children under the age of 15 years.

  19. 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.

  20. Nosocomial viral respiratory infections.

    PubMed

    Graman, P S; Hall, C B

    1989-12-01

    Nosocomial infections with respiratory tract viruses, particularly influenza and respiratory syncytial viruses, account for the majority of serious nosocomial viral disease. Chronically ill, immunocompromised, elderly, and very young hosts are especially vulnerable to potentially life-threatening involvement of the lower respiratory tract. Effective preventive strategies are based upon early accurate viral diagnosis and an appreciation of the epidemiology and mechanisms of transmission for each viral agent. Influenza viruses spread via airborne dispersion of small particle aerosols, resulting in explosive outbreaks; control measures emphasize immunization and chemoprophylaxis of susceptible patients and personnel, and isolation of those already infected. Transmission of respiratory syncytial virus, in contrast, seems to require closer contact, with virus passed on hands, fomites, or in large droplets inoculated into the eyes and nose at close range. Strategies for control of nosocomial respiratory syncytial virus are designed to interrupt hand carriage and inoculation of virus onto mucous membranes.

  1. Metaphylactic treatment strategies with toltrazuril and diclazuril and growth performance of buffalo calves exposed to a natural eimeria infection.

    PubMed

    Bosco, Antonio; Rinaldi, Laura; Cappelli, Giovanna; Saratsis, Anastasios; Nisoli, Lucio; Cringoli, Giuseppe

    2015-09-15

    Five controlled field trials were conducted in southern Italy to evaluate the effect of metaphylactic treatment strategies of toltrazuril and diclazuril for the control of coccidiosis in water buffaloes naturally infected by Eimeria spp. The 5 farms were divided into two types (A and B) according to their management system (individual or collective breeding of buffalo calves). In the farms of type A (no. 3), the buffalo calves were bred in individual boxes from the birth to the 7th/8th week of age and then transferred to concrete based pens; in the farms of type B (no. 2) the calves were bred in groups on concrete based pens from the birth. On each farm, 36 calves aged 5 weeks were divided at random into three similar groups of 12. One group was treated with toltrazuril (TOL), the second group was treated with diclazuril (DIC) and the third group was remained as untreated control group (CONT). On each farm the calves were weighed weekly and clinically examined. In the 5 buffalo farms the average oocyst excretion decreased significantly in both the treated groups (TOL and DIC), however the TOL groups had significantly low counts than the DIC groups. The body-weight gains recorded fortnightly were significantly higher in the TOL groups (range=5.4-8.1 kg) compared to the DIC (range=1.7-3.1 kg).

  2. Recruitment of Factor H as a Novel Complement Evasion Strategy for Blood-Stage Plasmodium falciparum Infection.

    PubMed

    Kennedy, Alexander T; Schmidt, Christoph Q; Thompson, Jennifer K; Weiss, Greta E; Taechalertpaisarn, Tana; Gilson, Paul R; Barlow, Paul N; Crabb, Brendan S; Cowman, Alan F; Tham, Wai-Hong

    2016-02-01

    The human complement system is the frontline defense mechanism against invading pathogens. The coexistence of humans and microbes throughout evolution has produced ingenious molecular mechanisms by which microorganisms escape complement attack. A common evasion strategy used by diverse pathogens is the hijacking of soluble human complement regulators to their surfaces to afford protection from complement activation. One such host regulator is factor H (FH), which acts as a negative regulator of complement to protect host tissues from aberrant complement activation. In this report, we show that Plasmodium falciparum merozoites, the invasive form of the malaria parasites, actively recruit FH and its alternative spliced form FH-like protein 1 when exposed to human serum. We have mapped the binding site in FH that recognizes merozoites and identified Pf92, a member of the six-cysteine family of Plasmodium surface proteins, as its direct interaction partner. When bound to merozoites, FH retains cofactor activity, a key function that allows it to downregulate the alternative pathway of complement. In P. falciparum parasites that lack Pf92, we observed changes in the pattern of C3b cleavage that are consistent with decreased regulation of complement activation. These results also show that recruitment of FH affords P. falciparum merozoites protection from complement-mediated lysis. Our study provides new insights on mechanisms of immune evasion of malaria parasites and highlights the important function of surface coat proteins in the interplay between complement regulation and successful infection of the host.

  3. Metaphylactic treatment strategies with toltrazuril and diclazuril and growth performance of buffalo calves exposed to a natural eimeria infection.

    PubMed

    Bosco, Antonio; Rinaldi, Laura; Cappelli, Giovanna; Saratsis, Anastasios; Nisoli, Lucio; Cringoli, Giuseppe

    2015-09-15

    Five controlled field trials were conducted in southern Italy to evaluate the effect of metaphylactic treatment strategies of toltrazuril and diclazuril for the control of coccidiosis in water buffaloes naturally infected by Eimeria spp. The 5 farms were divided into two types (A and B) according to their management system (individual or collective breeding of buffalo calves). In the farms of type A (no. 3), the buffalo calves were bred in individual boxes from the birth to the 7th/8th week of age and then transferred to concrete based pens; in the farms of type B (no. 2) the calves were bred in groups on concrete based pens from the birth. On each farm, 36 calves aged 5 weeks were divided at random into three similar groups of 12. One group was treated with toltrazuril (TOL), the second group was treated with diclazuril (DIC) and the third group was remained as untreated control group (CONT). On each farm the calves were weighed weekly and clinically examined. In the 5 buffalo farms the average oocyst excretion decreased significantly in both the treated groups (TOL and DIC), however the TOL groups had significantly low counts than the DIC groups. The body-weight gains recorded fortnightly were significantly higher in the TOL groups (range=5.4-8.1 kg) compared to the DIC (range=1.7-3.1 kg). PMID:26215929

  4. Immunoliposome-mediated drug delivery to Plasmodium-infected and non-infected red blood cells as a dual therapeutic/prophylactic antimalarial strategy.

    PubMed

    Moles, Ernest; Urbán, Patricia; Jiménez-Díaz, María Belén; Viera-Morilla, Sara; Angulo-Barturen, Iñigo; Busquets, Maria Antònia; Fernàndez-Busquets, Xavier

    2015-07-28

    One of the most important factors behind resistance evolution in malaria is the failure to deliver sufficiently high amounts of drugs to early stages of Plasmodium-infected red blood cells (pRBCs). Despite having been considered for decades as a promising approach, the delivery of antimalarials encapsulated in immunoliposomes targeted to pRBCs has not progressed towards clinical applications, whereas in vitro assays rarely reach drug efficacy improvements above 10-fold. Here we show that encapsulation efficiencies reaching >96% are achieved for the weak basic drugs chloroquine (CQ) and primaquine using the pH gradient loading method in liposomes containing neutral saturated phospholipids. Targeting antibodies are best conjugated through their primary amino groups, adjusting chemical crosslinker concentration to retain significant antigen recognition. Antigens from non-parasitized RBCs have also been considered as targets for the delivery to the cell of drugs not affecting the erythrocytic metabolism. Using this strategy, we have achieved unprecedented complete nanocarrier targeting to early intraerythrocytic stages of the malaria parasite for which there is a lack of specific extracellular molecular tags. Immunoliposomes studded with monoclonal antibodies raised against the erythrocyte surface protein glycophorin A were capable of targeting 100% RBCs and pRBCs at the low concentration of 0.5μM total lipid in the culture, with >95% of added liposomes retained on cell surfaces. When exposed for only 15min to Plasmodium falciparum in vitro cultures of early stages, free CQ had no significant effect on the viability of the parasite up to 200nM, whereas immunoliposomal 50nM CQ completely arrested its growth. In vivo assays in mice showed that immunoliposomes cleared the pathogen below detectable levels at a CQ dose of 0.5mg/kg, whereas free CQ administered at 1.75mg/kg was, at most, 40-fold less efficient. Our data suggest that this significant improvement is in part

  5. 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

  6. 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

  7. 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

  8. Less drug regimens and PI/r-based strategies in HIV infection: focus on best practices using the HIV patient's journey methodology.

    PubMed

    Marcotullio, Simone; Ammassari, Adriana; Andreoni, Massimo; Antinori, Andrea; Bonora, Stefano; d'Arminio Monforte, Antonella; Di Perri, Giovanni; Galli, Massimo; Gervasoni, Cristina; Iardino, Rosaria; Ippolito, Giuseppe; Lo Caputo, Sergio; Nozza, Silvia; Perno, Carlo Federico; Rizzardini, Giuliano; Lazzarin, Adriano

    2014-04-01

    During these last two years less drug regimens (LDRs) in HIV, and in particular protease inhibitor (PI)/r-based strategies, have been explored both in clinical trials and in clinical practice. Many results are now available and more is known about how to use them safely and effectively. Understanding that an LDR strategy represents a real tailored therapeutic approach for the patient is crucial for the long-term success and positive management of HIV infection. Trust between patients and HIV specialists and a real focus on the patient's life are key factors for long life treatment success, in particular when using a LDR strategy. This is clearly shown by the HIV patient's journey (HPJ) methodology, used in an Italian national workshop to better define the criteria and challenges of LDR strategies. This paper shows the results of this complex process.

  9. 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

  10. 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

  11. Early fungal infection in an aortic prosthesis with probable cerebral metastasis: the success of a conservative strategy.

    PubMed

    Guedes, Anabela Malho; de Macedo, Teresa Anastácio; Rocha, Carla; Neves, José; Mapril, Joana

    2013-02-01

    Infection of an aortic prosthesis presents a diagnostic and therapeutic challenge. Fungal infections are rarely described and among these Candida spp. are the most prevalent agents. Although the therapeutic approach to prosthetic bacterial infection may be conservative, in the case of fungal etiology, surgery, such as the removal and substitution of the device, debridement and repair of the infected prosthesis is usually warranted. The authors describe the case of a 48-year-old man, with a thoraco-abdominal aneurysm of the aorta, submitted to surgery for insertion of a prosthetic aortic duct. The procedure was made difficult by Candida albicans empyema associated with an aortic prosthesis infection that was complicated by probable cerebral metastasis. Antifungal therapy was the initial option, as the steady clinical, laboratory and radiological improvement deferred a surgical intervention. This case demonstrates the success of a conservative approach in a very serious fungal infection of a thoraco-abdominal aorta prosthesis.

  12. 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.

  13. Infection persistence time of Aedes breeding habitats

    NASA Astrophysics Data System (ADS)

    Bicout, D. J.; Chalvet-Monfray, K.; Sabatier, P.

    2002-03-01

    The Aedes mosquito species are capable of maintaining the circulation of viruses only by the strategy of transovarial transmission and diapause of eggs. It is found that when the transovarial transmission is inhibited, the survival time of the presence of viruses in a given mosquito habitat is limited from above by the eggs lifetime. In contrast, when the transovarial transmission is turned on, the infection persistence time may largely exceed both the eggs lifetime and flooding period depending upon the production rate of infected eggs. We present a simple model allowing the derivation of analytical expressions of the infection persistence time.

  14. 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 ...

  15. 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. PMID:8995676

  16. 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

  17. High rates of reinfection and incidence of bacterial sexually transmitted infections in a cohort of female sex workers from two Indian cities: need for different STI control strategies?

    PubMed Central

    Das, Anjana; Pathni, Anupam Khungar; Narayanan, Prakash; George, Bitra; Morineau, Guy; Saidel, Tobi; Prabhakar, Parimi; Deshpande, Gururaj Rao; Gangakhedkar, Raman; Mehendale, Sanjay; Risbud, Arun

    2013-01-01

    Background Female sex workers (FSWs) in India are provided a standardised package of clinical interventions for management of sexually transmitted infections (STIs). A study was conducted among FSWs at known high STI prevalence sites to determine the effectiveness of the service package. Methods A cohort of FSW clinic attendees in two cities, Hyderabad and Mumbai, were enrolled and followed up from October 2008 to November 2009. At each visit, behavioural and clinical data were obtained and vaginal swabs collected for laboratory testing of cervical infections (gonorrhoea and chlamydia). Results 417 participants were enrolled, of whom 360 attended at least a follow-up visit. Prevalence of cervical infections did not change between the baseline and final visits (27.7% and 21.3% respectively, p=0.08) in spite of presumptive treatment at baseline and syndromic management at all visits. The proportion of asymptomatic cervical infections increased from 36% at baseline to 77% at the final visit. Incidence rate of cervical infections was high (85.6/100 person years) and associated with a prevalent cervical infection at baseline (HR=2.7, p<0.001) and inconsistent condom use with non-commercial partners (HR=2.5, p=0.014). Conclusions High rates of STIs persisted despite the interventions due to poor condom use, minimal partner treatment, and high prevalence and incidence of STIs with a large proportion of asymptomatic infections. High-prevalence FSW sites in India need to design more effective partner treatment strategies and consider increasing the frequency of presumptive treatment as a temporary measure for quickly reducing STI prevalence, with renewed emphasis on consistent condom use with all partners. PMID:23196329

  18. Stable isotope tagging of epitopes: a highly selective strategy for the identification of major histocompatibility complex class I-associated peptides induced upon viral infection.

    PubMed

    Meiring, Hugo D; Soethout, Ernst C; Poelen, Martien C M; Mooibroek, Dennis; Hoogerbrugge, Ronald; Timmermans, Hans; Boog, Claire J; Heck, Albert J R; de Jong, Ad P J M; van Els, Cécile A C M

    2006-05-01

    Identification of peptides presented in major histocompatibility complex (MHC) class I molecules after viral infection is of strategic importance for vaccine development. Until recently, mass spectrometric identification of virus-induced peptides was based on comparative analysis of peptide pools isolated from uninfected and virus-infected cells. Here we report on a powerful strategy aiming at the rapid, unambiguous identification of naturally processed MHC class I-associated peptides, which are induced by viral infection. The methodology, stable isotope tagging of epitopes (SITE), is based on metabolic labeling of endogenously synthesized proteins during infection. This is accomplished by culturing virus-infected cells with stable isotope-labeled amino acids that are expected to be anchor residues (i.e. residues of the peptide that have amino acid side chains that bind into pockets lining the peptide-binding groove of the MHC class I molecule) for the human leukocyte antigen allele of interest. Subsequently these cells are mixed with an equal number of non-infected cells, which are cultured in normal medium. Finally peptides are acid-eluted from immunoprecipitated MHC molecules and subjected to two-dimensional nanoscale LC-MS analysis. Virus-induced peptides are identified through computer-assisted detection of characteristic, binomially distributed ratios of labeled and unlabeled molecules. Using this approach we identified novel measles virus and respiratory syncytial virus epitopes as well as infection-induced self-peptides in several cell types, showing that SITE is a unique and versatile method for unequivocal identification of disease-related MHC class I epitopes.

  19. Removal of waterborne pathogens from liver transplant unit water taps in prevention of healthcare-associated infections: a proposal for a cost-effective, proactive infection control strategy.

    PubMed

    Zhou, Z Y; Hu, B J; Qin, L; Lin, Y E; Watanabe, H; Zhou, Q; Gao, X D

    2014-04-01

    Hospital water supplies often contain waterborne pathogens, which can become a reservoir for healthcare-associated infections (HAIs). We surveyed the extent of waterborne pathogen contamination in the water supply of a Liver Transplant Unit. The efficacy of point-of-use (POU) water filters was evaluated by comparative analysis in routine clinical use. Our baseline environmental surveillance showed that Legionella spp. (28%, 38/136), Pseudomonas aeruginosa (8%, 11/136), Mycobacterium spp. (87%, 118/136) and filamentous fungi (50%, 68/136) were isolated from the tap water of the Liver Transplant Unit. 28.9% of Legionella spp.-positive water samples (n = 38) showed high-level Legionella contamination (≥10(3) CFU/L). After installation of the POU water filter, none of these pathogens were found in the POU filtered water samples. Furthermore, colonizations/infections with Gram-negative bacteria determined from patient specimens were reduced by 47% during this period, even if only 27% (3/11) of the distal sites were installed with POU water filters. In conclusion, the presence of waterborne pathogens was common in the water supply of our Liver Transplant Unit. POU water filters effectively eradicated these pathogens from the water supply. Concomitantly, healthcare-associated colonization/infections declined after the POU filters were installed, indicating their potential benefit in reducing waterborne HAIs.

  20. 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. PMID:27014215

  1. 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

  2. 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.

  3. 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

  4. 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.

  5. 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

  6. 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

  7. 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

  8. 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

  9. Liver Disease Burden of Hepatitis C Virus Infection in Iran and the Potential Impact of Various Treatment Strategies on the Disease Burden

    PubMed Central

    Hajarizadeh, Behzad; Razavi-Shearer, Devin; Merat, Shahin; Alavian, Seyed Moayed; Malekzadeh, Reza; Razavi, Homie

    2016-01-01

    Background Chronic hepatitis C virus (HCV) infection is emerging as the leading cause of viral hepatitis-related liver disease in Iran. Objectives This study estimated the current and future disease burden of HCV infection in Iran and assessed the impact of various strategies in access to HCV treatment on reducing the disease burden. Materials and Methods A modelling approach was used to estimate the size of HCV infected population, and disease progression from 2014 to 2030. Literature review and expert consensus informed the model parameters. Base case scenario assumed the currently utilized Interferon (IFN)-based treatment. Five other scenarios assumed utilizing IFN-free direct acting anti-viral regimens with 1, the base case diagnosis and treatment uptake; 2, restricting treatment to severe liver fibrosis; 3, treatment uptake being doubled; 4, stepwise increase in treatment uptake (doubled by 2017, quadrupled thereafter); 5, targeting at least 90% reduction in HCV infections by 2030. Results In 2014, an estimated 186,500 individuals are living with HCV infection in Iran (median age: 30 years). By 2030, this number will increase to 213,700, while three to four fold increase is expected in the case numbers of decompensated cirrhosis (DC, n = 620), hepatocellular carcinoma (HCC, n = 510), and liver disease death (n = 400), assuming the current diagnosis/treatment settings. As compared with the base case scenario, scenarios 1 and 2 will have a limited impact on HCV disease burden, while scenarios 3 and 4 will result in 45% - 49% decrease in the number of individuals living with HCV infection and 60% - 69% decrease in DC, HCC and liver disease deaths by 2030. For at least 90% reduction in HCV infections by 2030 (scenario 5), diagnosis and treatment rates should be increased to 12,000 and 9,000 individuals per year in 2016, respectively and to 24,000 and 18,000 individuals per year, respectively in 2018 onward. Conclusions An increasing burden of HCV-related liver

  10. 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

  11. Ionic versus nonionic contrast use.

    PubMed

    Stolberg, H O; McClennan, B L

    1991-01-01

    It has taken many years of research, development and intense scientific investigation to produce intravascular contrast media. Research on relations between chemical structure, animal toxicity, and water-solubility has produced a number of highly water-soluble, iodinated compounds for use in diagnostic radiology as intravascular contrast agents. The currently used intravascular agents may be classified into four groups according to their chemical structure: 1. Ionic monomers 2. Ionic monoacid dimers 3. Nonionic monomers 4. Nonionic dimers It is the objective of this publication to review the history and development of intravascular contrast media as well as their properties, general effects and clinical use. The four types of contrast media differ significantly in their chemical structure and physico-chemical properties, and these differences determine their osmotoxicity, chemotoxicity, and ion toxicity. We analyze the organ specific toxic effects of intravascular contrast media upon the central nervous system, the cardiovascular system, and the renal system. We also review the secondary effects, clinical manifestations, and the incidence of adverse events associated with different types of contrast. The choice of contrast media has become critical since the introduction of nonionic agents because their toxicological and pharmacological properties differ from those of the ionic agents. The application of basic concepts involved in the use of contrast media in excretory urography, computed tomography, angiography, and angiocardiography is discussed, and the advantages of the use of nonionic contrast agents are outlined. Economic and ethical issues are presented with emphasis upon strategies to reduce the risk associated with the injection of intravascular contrast and to curtail consumption according to rational principles of use. PMID:2049958

  12. 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.

  13. Host AMPK Is a Modulator of Plasmodium Liver Infection.

    PubMed

    Ruivo, Margarida T Grilo; Vera, Iset Medina; Sales-Dias, Joana; Meireles, Patrícia; Gural, Nil; Bhatia, Sangeeta N; Mota, Maria M; Mancio-Silva, Liliana

    2016-09-01

    Manipulation of the master regulator of energy homeostasis AMP-activated protein kinase (AMPK) activity is a strategy used by many intracellular pathogens for successful replication. Infection by most pathogens leads to an activation of host AMPK activity due to the energetic demands placed on the infected cell. Here, we demonstrate that the opposite is observed in cells infected with rodent malaria parasites. Indeed, AMPK activity upon the infection of hepatic cells is suppressed and dispensable for successful infection. By contrast, an overactive AMPK is deleterious to intracellular growth and replication of different Plasmodium spp., including the human malaria parasite, P. falciparum. The negative impact of host AMPK activity on infection was further confirmed in mice under conditions that activate its function. Overall, this work establishes the role of host AMPK signaling as a suppressive pathway of Plasmodium hepatic infection and as a potential target for host-based antimalarial interventions. PMID:27568570

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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

  20. Eradication strategy for persistent methicillin-resistant Staphylococcus aureus infection in individuals with cystic fibrosis—the PMEP trial: study protocol for a randomized controlled trial

    PubMed Central

    2014-01-01

    Background The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) respiratory infection in cystic fibrosis (CF) has increased dramatically over the last decade, and is now affecting approximately 25% of patients. Epidemiologic evidence suggests that persistent infection with MRSA results in an increased rate of decline in FEV1 and shortened survival. Currently, there are no conclusive studies demonstrating an effective and safe treatment protocol for persistent MRSA respiratory infection in CF. Methods/Design The primary objective of this study is to evaluate the safety and efficacy of a 28-day course of vancomycin for inhalation in combination with oral antibiotics in eliminating MRSA from the respiratory tract of individuals with CF and persistent MRSA infection. This is a two-center, randomized, double-blind, comparator-controlled, parallel-group study with 1:1 assignment to either vancomycin for inhalation (250 mg twice a day) or taste-matched placebo for 28 days in individuals with cystic fibrosis. In addition, both groups will receive oral rifampin, a second oral antibiotic – trimethoprim/sulfamethoxazole (TMP/SMX) or doxycycline, protocol determined – mupirocin intranasal cream, and chlorhexidine body washes. Forty patients with persistent respiratory tract MRSA infection will be enrolled: 20 will be randomized to vancomycin for inhalation and 20 to a taste-matched placebo. The primary outcome will be the presence of MRSA in sputum respiratory tract cultures 1 month after the conclusion of treatment. Secondary outcomes include the efficacy of the intervention on: FEV1% predicted, patient reported outcomes, pulmonary exacerbations, and MRSA colony-forming units found in respiratory tract sample culture. Discussion Results of this study will provide guidance to clinicians regarding the safety and effectiveness of a targeted eradication strategy for persistent MRSA infection in CF. Trial registration This trial is registered at Clinical

  1. 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. PMID:24836164

  2. Economic evaluation of test-and-treat and empirical treatment strategies in the eradication of Helicobacter pylori infection; A Markov model in an Iranian adult population

    PubMed Central

    Mazdaki, Alireza; Ghiasvand, Hesam; Sarabi Asiabar, Ali; Naghdi, Seyran; Aryankhesal, Aidin

    2016-01-01

    Background: Helicobacter pylori may cause many gastrointestinal problems in developing countries such as Iran. We aimed to analyze the cost- effectiveness and cost- utility of the test-and-treat and empirical treatment strategies in managing Helicobacter pylori infection. Methods: This was a Markov based economic evaluation. Effectiveness was defined as the symptoms free numbers and QALYs in 100,000 hypothetical adults. The sensitivity analysis was based on Monte Carlo approach. Results: In the test- and- treat strategy, if the serology is the first diagnostic test vs. histology, the cost per symptoms free number would be 291,736.1 Rials while the cost per QALYs would be 339,226.1 Rials. The cost per symptoms free number and cost per QALYs when the 13 C-UBT was used as the first diagnostic test vs. serology was 1,283,200 and 1,492,103 Rials, respectively. In the empirical strategy, if histology is used as the first diagnostic test vs. 13 CUBT, the cost per symptoms free numbers and cost per QALYs would be 793,234 and 955,698 Rials, respectively. If serology were used as the first diagnostic test vs. histology, the cost per symptoms free and QALYs would be 793,234 and 368941 Rials, respectively. Conclusion: There was no significant and considerable dominancy between the alternatives and the diagnostic tests. PMID:27390697

  3. 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. PMID:26588197

  4. 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

  5. Recurrent urinary tract infections in otherwise healthy adult women. Rational strategies for work-up and management.

    PubMed

    Leiner, S

    1995-02-01

    Recurrent urinary tract infections (UTIs) are common, but clinicians unfamiliar with the natural history or pathogenesis may order unnecessarily expensive tests and provide unsubstantiated advice to their patients. A large body of literature indicates that recurrent UTIs do not progress to permanent kidney damage or end-stage renal disease. The vast number of UTIs are due to the interplay between minor weaknesses in host defenses and bacterial virulence factors. Sexual intercourse and diaphragm/spermicide use are the two behavioral factors most consistently associated with UTIs. Basic history, physical exam, and urinalysis are able to identify the few patients likely to benefit from invasive urologic workups, which usually have a very low yield when ordered routinely. Effective management options include daily or post-coital antimicrobial prophylaxis, or patient-initiated treatment. Patients can be reassured of an excellent prognosis. There is no evidence validating proscription of personal preferences, such as soda pop, tight clothing, or direction of perineal cleansing after defecation.

  6. Approved and novel strategies in diagnostics of rat bite fever and other Streptobacillus infections in humans and animals.

    PubMed

    Eisenberg, Tobias; Ewers, Christa; Rau, Jörg; Akimkin, Valerij; Nicklas, Werner

    2016-08-17

    Rat bite fever (RBF), a worldwide occurring and most likely under-diagnosed zoonosis caused by Streptobacillus moniliformis, represents the most prominent disease of Streptobacillus infections. Recently, novel members have been described, from which a reservoir in rats and other animal species and a zoonotic potential can be assumed. Despite regularly published case reports, diagnostics of RBF continues to represent a 'diagnostic dilemma', because the mostly applied 16S rRNA sequence analysis may be uncertain for proper pathogen identification. Virtually nothing is known regarding prevalence in humans and animal reservoirs. For a realistic assessment of the pathogen's spread, epidemiology and virulence traits, future studies should focus on the genomic background of Streptobacillus. Full genome sequence analyses of a representative collection of strains might facilitate to unequivocally identify and type isolates. Prevalence studies using selective enrichment mechanisms may also enable the isolation of novel strains and candidate species of this neglected group of microorganisms. PMID:27088660

  7. 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. PMID:20714805

  8. Prospective evaluation of a multi-factorial prevention strategy on the impact of nosocomial infection in very-low-birthweight infants.

    PubMed

    Andersen, C; Hart, J; Vemgal, P; Harrison, C

    2005-10-01

    The aim of this study was to examine the impact of a multi-factorial intervention on nosocomial infection in very-low-birthweight infants. Consecutive infants with a birth weight less than 1500 g, born between February 2002 and February 2003, were included in this prospective study. The first six-month period (control) included surveillance of current practice. The intervention began in the seventh month and included: (i) changes to handwashing solutions with hand hygiene education; (ii) standardization of intravascular device (IV) insertion with specialized packs; (iii) changes to skin antiseptic solutions (2% aqueous chlorhexidine and 1% chlorhexidine in ethanol); and (iv) mandatory removal or replacement of peripheral IV after 48 hours and removal once enteral intake was > 120 mL/kg/day. Demographic data and details of every device were collected prospectively. Bloodstream infections (BSIs), length of stay (LOS), length of ventilation (LOV) and death were recorded and the rate of nosocomial BSI was calculated. Overall, 174 newborns required 1359 devices. The two cohorts were similar for birth weight and gestation. There was a reduction in nosocomial BSIs from 21% to 9% (control vs. intervention) (P = 0.05, confidence intervals 0.19-1.0). There was no significant difference in LOS, LOV, or mortality. Four infants had complications from 2% chlorhexidine. In conclusion, implementation of the multi-factorial prevention strategy reduced nosocomial BSIs. Alternative antiseptic solutions are needed to reduce the complications caused by 2% aqueous chlorhexidine.

  9. Enhanced Expression of Full-Length Human Cytomegalovirus Fusion Protein in Non-Swelling Baculovirus-Infected Cells with a Minimal Fed-Batch Strategy

    PubMed Central

    Patrone, Marco; Carinhas, Nuno; Sousa, Marcos Q.; Peixoto, Cristina; Ciferri, Claudio; Carfì, Andrea; Alves, Paula M.

    2014-01-01

    Human cytomegalovirus congenital infection represents an unmet medical issue and attempts are ongoing to develop an effective vaccine. The virion fusion players of this enveloped virus are the natural targets to achieve this goal and to develop novel anti-viral therapies. The secreted ectodomain of the viral fusion factor glycoprotein B (gB) has been exploited so far as an alternative to the cumbersome expression of the wild type trans-membrane protein. In the soluble form, gB showed encouraging but limited potential as antigen candidate calling for further efforts. Here, the exhaustive evaluation of the Baculovirus/insect cell expression system has been coupled to an orthogonal screening for expression additives to produce full-length gB. In detail, rapamycin was found to prolong gB intracellular accumulation while inhibiting the infection-induced cell swelling. Not obvious to predict, this inhibition did not affect Baculovirus growth, revealing that the virus-induced cell size increase is a dispensable side phenotype. In parallel, a feeding strategy for the limiting nutrient cysteine has been set up which improved gB stability. This multi-modal scheme allowed the production of full-length, mutation-free gB in the milligram scale. The recombinant full-length gB obtained was embedded into a stable mono-dispersed particle substantially larger than the protein trimer itself, according to the reported association of this protein with detergent-resistant lipid domains. PMID:24595278

  10. A lacZ Reporter-Based Strategy for Rapid Expression Analysis and Target Validation of Mycobacterium tuberculosis Latent Infection Genes.

    PubMed

    Sood, Shivani; Kaur, Satinder; Shrivastava, Rahul

    2016-02-01

    We report a novel lacZ fusion vector and demonstrate its utility for expression analysis of genes associated with Mycobacterium tuberculosis latent infection. The vector contains E. coli (oriE) and mycobacterial (oriM) origins of replication, a kanamycin resistance gene (Km(r)) as selection marker, and a lacZ reporter gene in fusion with MCS for cloning of upstream regulatory sequence of the desired genes. β-galactosidase activity of the vector was standardized for expression analysis under latent mycobacterial conditions using Phsp60, a constitutive mycobacterial promoter, utilizing Mycobacterium smegmatis as model organism. Validation of the vector was done by cloning and expression analysis of PhspX (alpha crystalline) and Picl (isocitrate lyase), promoters from two of the genes shown to be involved in M. tuberculosis persistence. Both genes showed appreciable levels of β-galactosidase expression under hypoxia-induced persistent conditions in comparison to their actively replicating state. Expression analysis of a set of hypothetical genes was also done, of which Rv0628c showed increased expression under persistent conditions. The reported fusion vector and the strategy can be effectively used for short listing and validation of drug targets deduced from various non-conclusive approaches such as bioinformatics and microarray analysis against latent/persistent form of mycobacterial infection. PMID:26597215

  11. [Contrast sensitivity in glaucoma].

    PubMed

    Bartos, D

    1989-05-01

    Author reports on results of the contrast sensitivity examinations using the Cambridge low-contrast lattice test supplied by Clement Clarke International LTD, in patients with open-angle glaucoma and ocular hypertension. In glaucoma patients there was observed statistically significant decrease of the contrast sensitivity. In patients with ocular hypertension decrease of the contrast sensitivity was in patients affected by corresponding changes of the visual field and of the optical disc. The main advantages of the Cambridge low-contrast lattice test were simplicity, rapidity and precision of its performance. PMID:2743444

  12. [The reduction of mother-child transmission of HIV infection in developing countries: potential intervention strategies, obstacles to implementation and perspectives. The Reduction of Mother-Child Transmission of HIV Infection in Africa Group].

    PubMed

    Meda, N; Msellati, P; Welffens-Ekra, C; Cartoux, M; Leroy, V; Van de Perre, P; Salamon, R

    1997-01-01

    Mother to child transmission (MCT) of Human Immunodeficiency Virus (HIV) is the main cause of the spread of the HIV epidemic in the pediatric population. It is estimated that to date, three million children worldwide have been infected by HIV. The epidemic burden in developing countries is dramatic. Ninety-five percent of the world's HIV-infected women are living in developing countries. In industrialized countries, antiretroviral treatment of pregnant women and newborns with azidothymidine (AZT, ACTG 076 regimen) and discouraging breast feeding by HIV-infected mothers are effectively reducing MCT of HIV. However, there are three major obstacles to the systematic application of these strategies in developing countries: (a) difficulties in implementing the complex AZT administration and its corollary the avoidance of breast feeding; (b) the complexity of the logistics of the ACTG 076 regimen; (c) cost. Indeed, in developing countries the socioeconomic situation of the populations are precarious and health structures and services are underdeveloped. In addition, the anxiety and the reluctance of general population in the face of the HIV problem and the high prevalence of maternal anemia reduce the acceptability and safety of AZT treatment for pregnant women in developing regions. Only interventions that are applicable, acceptable, safe, affordable, of low cost and integrated into health system will be able to reduce HIV MCT. We now know that MCT occurs mostly during the perinatal period and the maternal viral load in blood, in cervical secretions and in breast milk appears to be the main determinant of transmission. Maternal vitamin A deficiency may also favor MCT of HIV. It is however possible that this association is confounded by the relationship between advanced maternal HIV disease (a known risk factor for transmission) and vitamin A deficiency. In spite of these uncertainties concerning determinants of MCT of HIV, several interventions have been designed. The

  13. 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

  14. 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

  15. The Cost-Effectiveness of Monitoring Strategies for Antiretroviral Therapy of HIV Infected Patients in Resource-Limited Settings: Software Tool

    PubMed Central

    Estill, Janne; Salazar-Vizcaya, Luisa; Blaser, Nello; Egger, Matthias; Keiser, Olivia

    2015-01-01

    Background The cost-effectiveness of routine viral load (VL) monitoring of HIV-infected patients on antiretroviral therapy (ART) depends on various factors that differ between settings and across time. Low-cost point-of-care (POC) tests for VL are in development and may make routine VL monitoring affordable in resource-limited settings. We developed a software tool to study the cost-effectiveness of switching to second-line ART with different monitoring strategies, and focused on POC-VL monitoring. Methods We used a mathematical model to simulate cohorts of patients from start of ART until death. We modeled 13 strategies (no 2nd-line, clinical, CD4 (with or without targeted VL), POC-VL, and laboratory-based VL monitoring, with different frequencies). We included a scenario with identical failure rates across strategies, and one in which routine VL monitoring reduces the risk of failure. We compared lifetime costs and averted disability-adjusted life-years (DALYs). We calculated incremental cost-effectiveness ratios (ICER). We developed an Excel tool to update the results of the model for varying unit costs and cohort characteristics, and conducted several sensitivity analyses varying the input costs. Results Introducing 2nd-line ART had an ICER of US$1651-1766/DALY averted. Compared with clinical monitoring, the ICER of CD4 monitoring was US$1896-US$5488/DALY averted and VL monitoring US$951-US$5813/DALY averted. We found no difference between POC- and laboratory-based VL monitoring, except for the highest measurement frequency (every 6 months), where laboratory-based testing was more effective. Targeted VL monitoring was on the cost-effectiveness frontier only if the difference between 1st- and 2nd-line costs remained large, and if we assumed that routine VL monitoring does not prevent failure. Conclusion Compared with the less expensive strategies, the cost-effectiveness of routine VL monitoring essentially depends on the cost of 2nd-line ART. Our Excel tool is

  16. 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

  17. Electrocardiographic spatial QRS-T angle and incident cardiovascular disease in HIV-infected patients (from the Strategies for the Management of Antiretroviral Therapy [SMART] study).

    PubMed

    Dawood, Farah Z; Khan, Faraaz; Roediger, Mollie P; Zhang, Zhu-Ming; Swaminathan, Shobha; Klinker, Hartwig; Hoy, Jennifer; Lundgren, Jens D; Neaton, James D; Soliman, Elsayed Z

    2013-01-01

    Widening of the electrocardiographic (ECG) spatial QRS-T angle has been predictive of cardiovascular disease (CVD) events in the general population. However, its prognostic significance in human immunodeficiency virus (HIV)-infected patients remains unknown. The spatial QRS-T angle was derived from the baseline resting 12-lead electrocardiogram of 4,453 HIV-infected patients aged 43.5 ± 9.3 years from the Strategies for Management of Antiretroviral Therapy (SMART) trial. CVD events were identified during a median follow-up of 28.7 months. Quartiles of the spatial QRS-T angle was calculated for men and women separately, and values in the upper quartile were considered as a widened angle (values >74° for women and >93° for men). A multivariate Cox proportional hazards analysis was used to examine the association between a widened baseline spatial QRS-T angle and incident CVD events. During 11,965 person-years of follow-up, 152 CVD events occurred at a rate of 1.27 events/100 person-years. The rate of CVD events in those with a widened spatial QRS-T angle was almost double the rate in those with a normal spatial QRS-T angle (rate ratio 1.94, 95% confidence interval 1.40 to 2.69; p <0.001). In a model adjusted for study treatment arm, demographics, CVD risk factors, HIV characteristics, inflammatory markers, and other ECG abnormalities, a widened spatial QRS-T angle was associated with a >50% increased risk of CVD events compared to a normal spatial QRS-T angle (hazard ratio 1.53, 95% confidence interval 1.07 to 2.17; p = 0.02). No interaction was seen by SMART trial arm (p value for interaction = 0.37) or gender (p value for interaction = 0.84). In conclusion, a widened spatial QRS-T angle was independently predictive of CVD events in HIV-infected patients receiving antiretroviral therapy. This highlights the potential role of routine electrocardiography as a simple noninvasive CVD risk-screening tool in HIV-infected patients.

  18. 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

  19. 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

  20. Contrast Intravasation During Hysterosalpingography

    PubMed Central

    Bhoil, Rohit; Sood, Dinesh; Sharma, Tanupriya; Sood, Shilpa; Sharma, Jiten; Kumar, Nitesh; Ahluwalia, Ajay; Parekh, Dipen; Mistry, Kewal A.; Sood, Saurav

    2016-01-01

    Summary Hysterosalpingography is an imaging method to evaluate the endometrial and uterine morphology and fallopian tube patency. Contrast intravasation implies backflow of injected contrast into the adjoining vessels mostly the veins and may be related to factors altering endometrial vascularity and permeability. Radiologists and gynaecologists should be well acquainted with the technique of hysterosalpingography, its interpretation, and intravasation of contrast agents for safer procedure and to minimize the associated complications. PMID:27279925

  1. Sequential Treatment of Biofilms with Aztreonam and Tobramycin Is a Novel Strategy for Combating Pseudomonas aeruginosa Chronic Respiratory Infections.

    PubMed

    Rojo-Molinero, Estrella; Macià, María D; Rubio, Rosa; Moyà, Bartolomé; Cabot, Gabriel; López-Causapé, Carla; Pérez, José L; Cantón, Rafael; Oliver, Antonio

    2016-05-01

    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

  2. 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

  3. 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 Lists in Contrastive…

  4. Behavioral Contrast in Infants.

    ERIC Educational Resources Information Center

    Fagen, Jeffrey W.

    This study used the behavioral contrast paradigm to assess the excitatory and inhibitory capabilities of young infants. Behavioral contrast is described as the phenomenon whereby the rates of responding in the presence of two stimuli, both of which were previously associated with reinforcement, change in opposite directions when only one of them…

  5. "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

  6. Infections and intravascular devices.

    PubMed

    Elliott, T S; Faroqui, M H

    Complications associated with intravascular devices include infections mainly caused by Staphylococcus epidermis and S. aureus. The reported incidence of these infections varies. Several factors influence the propensity for catheter infections. We recommend strategies for the prevention and treatment of catheter-related sepsis. PMID:1422561

  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. 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

    2016-01-01

    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. PMID:27448107

  9. 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. PMID:22612448

  10. 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).

  11. Ferrimagnetic susceptibility contrast agents.

    PubMed

    Bach-Gansmo, T

    1993-01-01

    Contrast agents based on superparamagnetic particles have been in clinical development for more than 5 years, and the complexity of their effects is still not elucidated. The relaxivities are frequently used to give an idea of their efficacy, but these parameters can only be used if they are concentration independent. For large superparamagnetic systems, the evolution of the transverse magnetization is biexponential, after an initial loss of magnetization. Both these characteristics of large superparamagnetic systems should lead to prudence in using the relaxivities as indicators of contrast medium efficacy. Susceptibility induced artefacts have been associated with the use of superparamagnetic contrast agents since the first imaging evaluation took place. The range of concentrations where good contrast effect was achieved without inducing artefacts, as well as blurring and metal artefacts were evaluated. The influence of motion on the induction of artefacts was studied, and compared to the artefacts induced by a paramagnetic agent subject to motion. With a suitable concentration of a negative contrast agent, a signal void could be achieved in the region prone to motion, and no artefacts were induced. If the concentration was too high, a displacement of the region close to the contrast agent was observed. The artefacts occurred in a volume surrounding the contrast agent, i.e., also outside the imaging plane. In comparison a positive, paramagnetic contrast agent induced heavy artefacts in the phase encoding direction, appearing as both high intensity regions and black holes, in a mosaic pattern. Clinical trials of the oral contrast agent OMP for abdominal MR imaging showed this agent to be safe and efficacious. OMP increased the diagnostic efficacy of abdominal MR imaging in 2 of 3 cases examined, with a significant decrease in motion artefacts. Susceptibility contrast agents may also be of use in the evaluation of small lesions in the liver. Particulate material

  12. Chemiluminescent labels released from long spacer arm-functionalized magnetic particles: a novel strategy for ultrasensitive and highly selective detection of pathogen infections.

    PubMed

    Yang, Haowen; Liang, Wenbiao; He, Nongyue; Deng, Yan; Li, Zhiyang

    2015-01-14

    Previously, the unique advantages provided by chemiluminescence (CL) and magnetic particles (MPs) have resulted in the development of many useful nucleic acid detection methods. CL is highly sensitive, but when applied to MPs, its intensity is limited by the inner filter-like effect arising from excess dark MPs. Herein, we describe a modified strategy whereby CL labels are released from MPs to eliminate this negative effect. This approach relies on (1) the magnetic capture of target molecules on long spacer arm-functionalized magnetic particles (LSA-MPs), (2) the conjugation of streptavidin-alkaline phosphatase (SA-AP) to biotinylated amplicons of target pathogens, (3) the release of CL labels (specifically, AP tags), and (4) the detection of the released labels. CL labels were released from LSA-MPs through LSA ultrasonication or DNA enzymolysis, which proved to be the superior method. In contrast to conventional MPs, LSA-MPs exhibited significantly improved CL detection, because of the introduction of LSA, which was made of water-soluble carboxymethylated β-1,3-glucan. Detection of hepatitis B virus with this technique revealed a low detection limit of 50 fM, high selectivity, and excellent reproducibility. Thus, this approach may hold great potential for early stage clinical diagnosis of infectious diseases. PMID:25553360

  13. Chemiluminescent labels released from long spacer arm-functionalized magnetic particles: a novel strategy for ultrasensitive and highly selective detection of pathogen infections.

    PubMed

    Yang, Haowen; Liang, Wenbiao; He, Nongyue; Deng, Yan; Li, Zhiyang

    2015-01-14

    Previously, the unique advantages provided by chemiluminescence (CL) and magnetic particles (MPs) have resulted in the development of many useful nucleic acid detection methods. CL is highly sensitive, but when applied to MPs, its intensity is limited by the inner filter-like effect arising from excess dark MPs. Herein, we describe a modified strategy whereby CL labels are released from MPs to eliminate this negative effect. This approach relies on (1) the magnetic capture of target molecules on long spacer arm-functionalized magnetic particles (LSA-MPs), (2) the conjugation of streptavidin-alkaline phosphatase (SA-AP) to biotinylated amplicons of target pathogens, (3) the release of CL labels (specifically, AP tags), and (4) the detection of the released labels. CL labels were released from LSA-MPs through LSA ultrasonication or DNA enzymolysis, which proved to be the superior method. In contrast to conventional MPs, LSA-MPs exhibited significantly improved CL detection, because of the introduction of LSA, which was made of water-soluble carboxymethylated β-1,3-glucan. Detection of hepatitis B virus with this technique revealed a low detection limit of 50 fM, high selectivity, and excellent reproducibility. Thus, this approach may hold great potential for early stage clinical diagnosis of infectious diseases.

  14. A novel strategy to isolate cell-envelope mutants resistant to phage infection: bacteriophage mEp213 requires lipopolysaccharides in addition to FhuA to enter Escherichia coli K-12.

    PubMed

    Reyes-Cortés, Ruth; Martínez-Peñafiel, Eva; Martínez-Pérez, Francisco; de la Garza, Mireya; Kameyama, Luis

    2012-12-01

    We have developed a direct and efficient strategy, based on a three-step method, to select bacterial cell-envelope mutants resistant to bacteriophage infection. Escherichia coli K-12 strain W3110 underwent classical transposon mutagenesis followed by replica plating and selection for mutants resistant to infection by coliphage mEp213. To verify that phage resistance was due to mutations in the cell envelope, we transformed host cells with the viral genome using electroporation and selected those in which virions were subsequently detected in the supernatant. Among the nine mutants resistant to coliphage infection that we selected, six were in the fhuA gene, two were mutated in the waaC gene, and one was mutated in the gmhD gene. The latter two gene products are involved in the synthesis of lipopolysaccharide (LPS). The efficiency of plating and adsorption of phage mEp213 was affected in these mutants. We verified that LPS is required for the efficient infection of phage λ as well. We propose that this mutation-and-selection strategy can be used to find host factors involved in the initial steps of phage infection for any cognate pair of phage and bacteria.

  15. Immunization with Recombinant Adenoviral Vectors Expressing HCV Core or F Proteins Leads to T Cells with Reduced Effector Molecules Granzyme B and IFN-γ: A Potential New Strategy for Immune Evasion in HCV Infection.

    PubMed

    Samrat, Subodh Kumar; Vedi, Satish; Singh, Shakti; Li, Wen; Kumar, Rakesh; Agrawal, Babita

    2015-01-01

    Multispecific, broad, and potent T cell responses have been correlated with viral clearance in hepatitis C virus (HCV) infection. However, the majority of infected patients develop chronic infection, suggesting that natural infection mostly leads to development of inefficient T cell immunity. Multiple mechanisms of immune modulation and evasion have been shown in HCV infection through various investigations. This study examined the generation and modulation of T cell responses against core and frameshift (F) proteins of HCV. A single immunization of mice with replication incompetent recombinant adenovirus vectors encoding for F or core antigens induces poor T cell responses and leads to generation of CD4+ and CD8+ T cells with low granzyme B (GrB) expression. These T cells have impaired GrB enzyme activity and are unable to kill peptide loaded target cells. The low intracellular expression of GrB is not due to degranulation of cytotoxic granules containing cytotoxic T cells. Addition of exogenous IL-2 in in vitro cultures leads to partial recovery of GrB production, whereas immunization with the Toll-like receptor (TLR) agonist poly I:C leads to complete restoration of GrB expression in both CD4+ and CD8+ T cells. Thus, a possible new strategy of T cell modulation is recognized wherein effector T cells are caused to be dysfunctional by HCV-derived antigens F or core, and strategies are also delineated to overcome this dysfunction. These studies are important in the investigation of prophylactic vaccine and immunotherapy strategies for HCV infection.

  16. 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.

  17. 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

  18. [Contrast media in echography].

    PubMed

    Derchi, L E; Rizzatto, G; Solbiati, L

    1992-09-01

    In medical US, the use of specific contrast media to increase the echogenicity of structures and organs changes their absorption of the US beam, and modifies the through-transmission velocity. This can be of great diagnostic value. Contrast media can help depict vessels and cavities, increase the sensitivity of Doppler examination, and make the differentiation of normal and pathologic tissues easier. The products which are currently available do not completely fulfill the needs of clinical researchers. The first papers reporting on some clinical applications of these contrast media in humans are now appearing in literature. Contrast media for diagnostic US can be classified in five groups: 1) free gas bubbles; 2) stabilized gas bubbles; 3) colloidal suspensions; 4) emulsions; 5) aqueous solutions. These agents are quite different, as to both chemical and physical features and distribution within living tissues. Different clinical applications are thus possible for each of them; a unique contrast medium which will meet all the needs of the various clinical situations seems inconceivable at present. Most probably, a variety of products will develop, each with its own application field; in clinical practice, it seems likely that different products will be used, according to the specific clinical needs.

  19. Trypanosome-induced Interferon-γ production in whole blood stimulation assays is associated with latent Trypanosoma brucei gambiense infections.

    PubMed

    Ilboudo, Hamidou; Jamonneau, Vincent; Koffi, Mathurin; Kaboré, Jacques; Amoussa, Roukiyath; Holzmuller, Philippe; Garcia, André; Bucheton, Bruno; Courtin, David

    2016-06-01

    Control of human African trypanosomiasis (HAT) is highly dependent on the ability to detect and treat infected individuals. However, a number of individuals exposed to Trypanosoma brucei gambiense are able to control infection to undetectable levels in blood. They are long-term potential reservoirs and thus a threat for control strategies. Cytokine responses in whole blood stimulation assays were quantified in individuals with contrasting HAT status. Trypanosome-induced IFN-γ production was only observed in "trypanotolerant" subjects suspected of harboring latent infections. This result contributes new insights into the immune responses associated with infection control and opens novel diagnosis perspectives regarding HAT elimination. PMID:26993030

  20. Aspiration of Barium Contrast

    PubMed Central

    Fuentes Santos, Cristina; Steen, Bárbara

    2014-01-01

    The aspiration of barium contrast is a rare complication that may occur during studies of the digestive tract. Barium is an inert material that can cause anywhere from an asymptomatic mechanical obstruction to serious symptoms of respiratory distress that can result in patient death. We present the case of a 79-year-old male patient in whom we observed the presence of contrast medium residue in the lung parenchyma as an incidental finding during hospitalization. When the patient's medical file was reviewed, images were found of a barium swallow study that the patient had undergone months earlier, and we were able to observe the exact moment of the aspiration of the contrast material. The patient had been asymptomatic since the test. PMID:25309769

  1. Can we evaluate population screening strategies in UK general practice? A pilot randomised controlled trial comparing postal and opportunistic screening for genital chlamydial infection

    PubMed Central

    Senok, A.; Wilson, P.; Reid, M.; Scoular, A.; Craig, N.; McConnachie, A.; Fitzpatrick, B.; MacDonald, A.

    2005-01-01

    Study objective: To assess whether opportunistic and postal screening strategies for Chlamydia trachomatis can be compared with usual care in a randomised trial in general practice. Design: Feasibility study for a randomised controlled trial. Setting: Three West of Scotland general medical practices: one rural, one urban/deprived, and one urban/affluent. Participants: 600 women aged 16–30 years, 200 from each of three participating practices selected at random from a sample of West of Scotland practices that had expressed interest in the study. The women could opt out of the study. Those who did not were randomly assigned to one of three groups: postal screening, opportunistic screening, or usual care. Results: 38% (85 of 221) of the approached practices expressed interest in the study. Data were collected successfully from the three participating practices. There were considerable workload implications for staff. Altogether 124 of the 600 women opted out of the study. During the four month study period, 55% (81 of 146) of the control group attended their practice but none was offered screening. Some 59% (80 of 136) women in the opportunistic group attended their practice of whom 55% (44 of 80) were offered screening. Of those, 64% (28 of 44) accepted, representing 21% of the opportunistic group. Forty eight per cent (59 of 124) of the postal group returned samples. Conclusion: A randomised controlled trial comparing postal and opportunistic screening for chlamydial infection in general practice is feasible, although resource intensive. There may be problems with generalising from screening trials in which patients may opt out from the offer of screening. PMID:15709078

  2. 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

  3. 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. PMID:26837210

  4. Contrast image correction method

    NASA Astrophysics Data System (ADS)

    Schettini, Raimondo; Gasparini, Francesca; Corchs, Silvia; Marini, Fabrizio; Capra, Alessandro; Castorina, Alfio

    2010-04-01

    A method for contrast enhancement is proposed. The algorithm is based on a local and image-dependent exponential correction. The technique aims to correct images that simultaneously present overexposed and underexposed regions. To prevent halo artifacts, the bilateral filter is used as the mask of the exponential correction. Depending on the characteristics of the image (piloted by histogram analysis), an automated parameter-tuning step is introduced, followed by stretching, clipping, and saturation preserving treatments. Comparisons with other contrast enhancement techniques are presented. The Mean Opinion Score (MOS) experiment on grayscale images gives the greatest preference score for our algorithm.

  5. [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.

  6. 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

  7. 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…

  8. Directionality in Contrastive Analysis.

    ERIC Educational Resources Information Center

    James, Carl

    A contrastive analysis (CA) does not require commitment to directionality. Even asymmetrical interlingual correspondence can be handled by adirectional statements. If well executed, a CA is capable of handling three pairs of L2 learning phenomena: (1) going from language A to language B and vice versa; (2) productive and receptive command; and (3)…

  9. 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).

  10. 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.

  11. Peripheral venous contrast echocardiography.

    PubMed

    Seward, J B; Tajik, A J; Hagler, D J; Ritter, D G

    1977-02-01

    Contrast echocardiography is the technique of injecting various echo-producing agents into the bloodstream and, with standard echocardiographic techniques, observing the blood flow patterns as revealed by the resulting cloud of echoes. These techniques have only recently been utilized to evaluate various cardiac defects. Two physical properties of these agents characterize their usefulness: (1) clouds of echoes can be observed downstream as well as at the injection site, and (2) the echo-producing quality of these agents is completely lost with a single transit through either the pulmonary or the systemic capillary bed. Thus, detection of resultant echoes in both the venous and the arterial blood pool is indicative of abnormal shunting. In 60 patients with a spectrum of cardiac defects and a wide range in age of presentation, studies were made of (1) the feasibility of performing contrast echocardiography with superficial peripheral venous injections, and (2) the clinical usefulness of this relatively noninvasive technique in detecting and localizing intracardiac right ot left shunting. Most superficial peripheral veins could be utilized, and the resultant contrast echograms were reproducible and similar in quality to those obtained more central (caval) injections. Right to left shunts could be localized in the atrial, ventricular or intrapulmonary level. Characteristic flow patterns were also recognized for tricuspid atresia and common ventricle.

  12. Contrast adaptation in the Limulus lateral eye.

    PubMed

    Valtcheva, Tchoudomira M; Passaglia, Christopher L

    2015-12-01

    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

  13. Contrast adaptation in the Limulus lateral eye.

    PubMed

    Valtcheva, Tchoudomira M; Passaglia, Christopher L

    2015-12-01

    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.

  14. Apoptosis of Hippocampal Pyramidal Neurons Is Virus Independent in a Mouse Model of Acute Neurovirulent Picornavirus Infection

    PubMed Central

    Buenz, Eric J.; Sauer, Brian M.; LaFrance-Corey, Reghann G.; Deb, Chandra; Denic, Aleksandar; German, Christopher L.; Howe, Charles L.

    2009-01-01

    Many viruses, including picornaviruses, have the potential to infect the central nervous system (CNS) and stimulate a neuroinflammatory immune response, especially in infants and young children. Cognitive deficits associated with CNS picornavirus infection result from injury and death of neurons that may occur due to direct viral infection or during the immune responses to virus in the brain. Previous studies have concluded that apoptosis of hippocampal neurons during picornavirus infection is a cell-autonomous event triggered by direct neuronal infection. However, these studies assessed neuron death at time points late in infection and during infections that lead to either death of the host or persistent viral infection. In contrast, many neurovirulent picornavirus infections are acute and transient, with rapid clearance of virus from the host. We provide evidence of hippocampal pathology in mice acutely infected with the Theiler’s murine encephalomyelitis picornavirus. We found that CA1 pyramidal neurons exhibited several hallmarks of apoptotic death, including caspase-3 activation, DNA fragmentation, and chromatin condensation within 72 hours of infection. Critically, we also found that many of the CA1 pyramidal neurons undergoing apoptosis were not infected with virus, indicating that neuronal cell death during acute picornavirus infection of the CNS occurs in a non–cell-autonomous manner. These observations suggest that therapeutic strategies other than antiviral interventions may be useful for neuroprotection during acute CNS picornavirus infection. PMID:19608874

  15. Apoptosis of hippocampal pyramidal neurons is virus independent in a mouse model of acute neurovirulent picornavirus infection.

    PubMed

    Buenz, Eric J; Sauer, Brian M; Lafrance-Corey, Reghann G; Deb, Chandra; Denic, Aleksandar; German, Christopher L; Howe, Charles L

    2009-08-01

    Many viruses, including picornaviruses, have the potential to infect the central nervous system (CNS) and stimulate a neuroinflammatory immune response, especially in infants and young children. Cognitive deficits associated with CNS picornavirus infection result from injury and death of neurons that may occur due to direct viral infection or during the immune responses to virus in the brain. Previous studies have concluded that apoptosis of hippocampal neurons during picornavirus infection is a cell-autonomous event triggered by direct neuronal infection. However, these studies assessed neuron death at time points late in infection and during infections that lead to either death of the host or persistent viral infection. In contrast, many neurovirulent picornavirus infections are acute and transient, with rapid clearance of virus from the host. We provide evidence of hippocampal pathology in mice acutely infected with the Theiler's murine encephalomyelitis picornavirus. We found that CA1 pyramidal neurons exhibited several hallmarks of apoptotic death, including caspase-3 activation, DNA fragmentation, and chromatin condensation within 72 hours of infection. Critically, we also found that many of the CA1 pyramidal neurons undergoing apoptosis were not infected with virus, indicating that neuronal cell death during acute picornavirus infection of the CNS occurs in a non-cell-autonomous manner. These observations suggest that therapeutic strategies other than antiviral interventions may be useful for neuroprotection during acute CNS picornavirus infection. PMID:19608874

  16. Cold-seeking behaviour mitigates reproductive losses from fungal infection in Drosophila.

    PubMed

    Hunt, Vicky L; Zhong, Weihao; McClure, Colin D; Mlynski, David T; Duxbury, Elizabeth M L; Keith Charnley, A; Priest, Nicholas K

    2016-01-01

    Animals must tailor their life-history strategies to suit the prevailing conditions and respond to hazards in the environment. Animals with lethal infections are faced with a difficult choice: to allocate more resources to reproduction and suffer higher mortality or to reduce reproduction with the expectation of enhanced immunity and late-age reproduction. However, the strategies employed to mediate shifts in life-history traits are largely unknown. Here, we investigate the temperature preference of the fruit fly, Drosophila melanogaster, during infection with the fungal pathogen, Metarhizium robertsii, and the consequence of temperature preference on life-history traits. We have measured the temperature preference of fruit flies under different pathogen conditions. We conducted multiple fitness assays of the host and the pathogen under different thermal conditions. From these data, we estimated standard measures of fitness and used age-specific methodologies to test for the fitness trade-offs that are thought to underlie differences in life-history strategy. We found that fungus-infected fruit flies seek out cooler temperatures, which facilitates an adaptive shift in their life-history strategy. The colder temperatures preferred by infected animals were detrimental to the pathogen because it increased resistance to infection. But, it did not provide net benefits that were specific to infected animals, as cooler temperatures increased lifetime reproductive success and survival whether or not the animals were infected. Instead, we find that cold-seeking benefits infected animals by increasing their late-age reproductive output, at a cost to their early-age reproductive output. In contrast, naive control flies prefer warmer temperatures that optimize early-age reproductive, at a cost to reproductive output at late ages. These findings show that infected animals exhibit fundamentally different reproductive strategies than their healthy counterparts. Temperature

  17. Cold-seeking behaviour mitigates reproductive losses from fungal infection in Drosophila.

    PubMed

    Hunt, Vicky L; Zhong, Weihao; McClure, Colin D; Mlynski, David T; Duxbury, Elizabeth M L; Keith Charnley, A; Priest, Nicholas K

    2016-01-01

    Animals must tailor their life-history strategies to suit the prevailing conditions and respond to hazards in the environment. Animals with lethal infections are faced with a difficult choice: to allocate more resources to reproduction and suffer higher mortality or to reduce reproduction with the expectation of enhanced immunity and late-age reproduction. However, the strategies employed to mediate shifts in life-history traits are largely unknown. Here, we investigate the temperature preference of the fruit fly, Drosophila melanogaster, during infection with the fungal pathogen, Metarhizium robertsii, and the consequence of temperature preference on life-history traits. We have measured the temperature preference of fruit flies under different pathogen conditions. We conducted multiple fitness assays of the host and the pathogen under different thermal conditions. From these data, we estimated standard measures of fitness and used age-specific methodologies to test for the fitness trade-offs that are thought to underlie differences in life-history strategy. We found that fungus-infected fruit flies seek out cooler temperatures, which facilitates an adaptive shift in their life-history strategy. The colder temperatures preferred by infected animals were detrimental to the pathogen because it increased resistance to infection. But, it did not provide net benefits that were specific to infected animals, as cooler temperatures increased lifetime reproductive success and survival whether or not the animals were infected. Instead, we find that cold-seeking benefits infected animals by increasing their late-age reproductive output, at a cost to their early-age reproductive output. In contrast, naive control flies prefer warmer temperatures that optimize early-age reproductive, at a cost to reproductive output at late ages. These findings show that infected animals exhibit fundamentally different reproductive strategies than their healthy counterparts. Temperature

  18. 75 FR 29772 - Healthcare Infection Control Practices Advisory Committee, (HICPAC)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-27

    ... Zoonotic Infectious Diseases (NCEZID) regarding (1) The practice of healthcare infection control; (2) strategies for surveillance, prevention, and control of infections (e.g., nosocomial infections... HUMAN SERVICES Centers for Disease Control and Prevention Healthcare Infection Control...

  19. 76 FR 29756 - Healthcare Infection Control Practices Advisory Committee (HICPAC)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-23

    ... Healthcare Quality Promotion regarding (1) The practice of healthcare infection control; (2) strategies for surveillance, prevention, and control of infections (e.g., nosocomial infections), antimicrobial resistance... HUMAN SERVICES Centers for Disease Control and Prevention Healthcare Infection Control...

  20. 75 FR 63844 - Healthcare Infection Control Practices Advisory Committee (HICPAC)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-18

    ... healthcare infection control and strategies for surveillance, prevention, and control of healthcare-associated infections (e.g., nosocomial infections), antimicrobial resistance, and related events in settings... HUMAN SERVICES Centers for Disease Control and Prevention Healthcare Infection Control...

  1. 76 FR 63622 - Healthcare Infection Control Practices Advisory Committee, (HICPAC)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-13

    ... Healthcare Quality Promotion regarding (1) The practice of healthcare infection control; (2) strategies for surveillance, prevention, and control of infections (e.g., nosocomial infections), antimicrobial resistance... HUMAN SERVICES Centers for Disease Control and Prevention Healthcare Infection Control...

  2. 75 FR 50770 - Healthcare Infection Control Practices Advisory Committee (HICPAC)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-17

    ... Infectious Diseases (NCEZID), regarding: (1) The practice of hospital infection control; strategies for surveillance, prevention, and control of infections (e.g., nosocomial infections), antimicrobial resistance... HUMAN SERVICES Centers for Disease Control and Prevention Healthcare Infection Control...

  3. 75 FR 22816 - Healthcare Infection Control Practices Advisory Committee (HICPAC)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-30

    ...), regarding the practice of hospital infection control and strategies for surveillance, prevention, and control of healthcare-associated infections (e.g., nosocomial infections), antimicrobial resistance, and... HUMAN SERVICES Centers for Disease Control and Prevention Healthcare Infection Control...

  4. 75 FR 3912 - Healthcare Infection Control Practices Advisory Committee (HICPAC)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-25

    ... Control of Infectious Diseases (NCPDCID), regarding: (1) The practice of hospital infection control; (2) strategies for surveillance, prevention, and control of infections (e.g., nosocomial infections... HUMAN SERVICES Centers for Disease Control and Prevention Healthcare Infection Control...

  5. 77 FR 58397 - Healthcare Infection Control Practices Advisory Committee (HICPAC)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-20

    ... Infectious Disease (NCEZID), CDC, regarding (1) the practice of infection control; (2) strategies for surveillance, prevention, and control of healthcare-associated infections (e.g., nosocomial infections... HUMAN SERVICES Centers for Disease Control and Prevention Healthcare Infection Control...

  6. A dynamic transmission model with age-dependent infectiousness and reactivation for cytomegalovirus in the United States: Potential impact of vaccination strategies on congenital infection.

    PubMed

    Hogea, Cosmina; Dieussaert, Ilse; Van Effelterre, Thierry; Guignard, Adrienne; Mols, Johann

    2015-01-01

    We present an age-structured dynamic transmission model for cytomegalovirus (CMV) in the United States, based on natural history and available data, primarily aiming to combine the available qualitative and quantitative knowledge toward more complex modeling frameworks to better reflect the underlying biology and epidemiology of the CMV infection. The model structure explicitly accounts for primary infections, reactivations and re-infections. Duration of infectiousness and likelihood of reactivation were both assumed to be age-dependent, and natural reduction in the re-infection risk following primary infection was included. We used an empirical social contact matrix (POLYMOD-based) as support for CMV transmission between different age groups. The baseline model reproduced well the age-stratified seroprevalence data (National Health and Nutrition Examination Survey III) used for calibration. The model was further used to explore the potential impact of hypothetical vaccination on reducing congenital CMV infection under various vaccine profiles and vaccination scenarios. Our preliminary model-based simulations suggested that while infant vaccination may represent an attractive way to reduce congenital CMV infection over time, adolescent female vaccination with an adequate routine booster platform may, under certain conditions, provide an alternative. However, for such tools to be considered toward actual decision-making, enhanced validations based on additional studies and data would be further necessary. The modeling framework presented in this paper was designed to be sufficiently general and flexible, such that it can allow for further adaptations to reflect new knowledge or data that may become available in the future.

  7. 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.

  8. 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 Central

    Alarcon, Pablo; Rushton, Jonathan; Nathues, Heiko; Wieland, Barbara

    2013-01-01

    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’,

  9. 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

  10. 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 ...

  11. Viral infection

    PubMed Central

    Puigdomènech, Isabel; de Armas-Rillo, Laura; Machado, José-David

    2011-01-01

    Viruses have developed different survival strategies in host cells by crossing cell-membrane compartments, during different steps of their viral life cycle. In fact, the non-regenerative viral membrane of enveloped viruses needs to encounter the dynamic cell-host membrane, during early steps of the infection process, in which both membranes fuse, either at cell-surface or in an endocytic compartment, to promote viral entry and infection. Once inside the cell, many viruses accomplish their replication process through exploiting or modulating membrane traffic, and generating specialized compartments to assure viral replication, viral budding and spreading, which also serve to evade the immune responses against the pathogen. In this review, we have attempted to present some data that highlight the importance of membrane dynamics during viral entry and replicative processes, in order to understand how viruses use and move through different complex and dynamic cell-membrane structures and how they use them to persist. PMID:21966556

  12. Therapeutic strategy for pandrug-resistant Klebsiella pneumoniae severe infections: short-course treatment with colistin increases the in vivo and in vitro activity of double carbapenem regimen.

    PubMed

    Oliva, Alessandra; Mascellino, Maria T; Cipolla, Alessia; D'Abramo, Alessandra; De Rosa, Annalisa; Savinelli, Stefano; Ciardi, Maria Rosa; Mastroianni, Claudio M; Vullo, Vincenzo

    2015-04-01

    Infections due to carbapenemase-producing Klebsiella pneumoniae represent an emerging threat due to the high mortality rate and lack of valid antimicrobial combinations, especially when the strain is colistin-resistant. We report a case of bloodstream infection due to pandrug-resistant K. pneumoniae treated successfully with an innovative regimen comprising a combination of colistin plus double carbapenem, along with an in vitro analysis showing the synergistic and bactericidal effect.

  13. A prospective strategy to restore the tissue damage in malaria infection: Approach with chitosan-trypolyphosphate conjugated nanochloroquine in Swiss mice.

    PubMed

    Tripathy, Satyajit; Das, Sabyasachi; Dash, Sandeep Kumar; Mahapatra, Santanu Kar; Chattopadhyay, Sourav; Majumdar, Subrata; Roy, Somenath

    2014-08-15

    Accumulating evidence indicates that wide range of polymer based nanoconjugated drug have the ability to overcome the microbial infection. The present study was to evaluate the effects of nanoconjugated chloroquine (Nch) against Plasmodium berghei NK65 (P. berghei) infection on selective makers of oxidative damage, antioxidant status, pro-inflammatory and anti-inflammatory cytokines in liver and spleen. P. berghei infected Swiss mice were treated with Nch (250mg/kg bw for 15 days) compared with chloroquine. The stress markers, pro-inflammatory cytokines were increased significantly (P<0.05) and the anti-oxidant enzymes level, redox ratio (GSH/GSSG), anti-inflammatory markers were decreased significantly (P<0.05) in liver and spleen of infected mice compared with uninfected mice. Chloroquine and Nch effectively decreased the stress markers, pro-inflammatory cytokines, as well as, increased antioxidants level in liver and spleen of the infected mice. Moreover, the favorable effect Nch is better than the chloroquine defending the tissue damage during malarial infection. These findings suggested that the potential use and prospective role of Nch than only chloroquine against P. berghei induced pathology as well as oxidative damage in liver and spleen.

  14. 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…

  15. Adaptive color contrast enhancement for digital images

    NASA Astrophysics Data System (ADS)

    Wang, Yanfang; Luo, Yupin

    2011-11-01

    Noncanonical illumination that is too dim or with color cast induces degenerated images. To cope with this, we propose a method for color-contrast enhancement. First, intensity, chrominance, and contrast characteristics are explored and integrated in the Naka-Rushton equation to remove underexposure and color cast simultaneously. Motivated by the comparison mechanism in Retinex, the ratio of each pixel to its surroundings is utilized to improve image contrast. Finally, inspired by the two color-opponent dimensions in CIELAB space, a color-enhancement strategy is devised based on the transformation from CIEXYZ to CIELAB color space. For images that suffer from underexposure, color cast, or both problems, our algorithm produces promising results without halo artifacts and corruption of uniform areas.

  16. Necrotizing soft tissue infections

    PubMed Central

    Urschel, J.

    1999-01-01

    Necrotizing soft tissue infections are a group of highly lethal infections that typically occur after trauma or surgery. Many individual infectious entities have been described, but they all have similar pathophysiologies, clinical features, and treatment approaches. The essentials of successful treatment include early diagnosis, aggressive surgical debridement, antibiotics, and supportive intensive treatment unit care. The two commonest pitfalls in management are failure of early diagnosis and inadequate surgical debridement. These life-threatening infections are often mistaken for cellulitis or innocent wound infections, and this is responsible for diagnostic delay. Tissue gas is not a universal finding in necrotizing soft tissue infections. This misconception also contributes to diagnostic errors. Incision and drainage is an inappropriate surgical strategy for necrotizing soft tissue infections; excisional debridement is needed. Hyperbaric oxygen therapy may be useful, but it is not as important as aggressive surgical therapy. Despite advances in antibiotic therapy and intensive treatment unit medicine, the mortality of necrotizing soft tissue infections is still high. This article emphasizes common treatment principles for all of these infections, and reviews some of the more important individual necrotizing soft tissue infectious entities.


Keywords: fasciitis; gas gangrene; clostridium infections; streptococcal infections; necrosis; debridement; surgical infections; soft tissue infections PMID:10621873

  17. Inhibition of Enveloped Virus Infection of Cultured Cells by Valproic Acid▿ †

    PubMed Central

    Vázquez-Calvo, Ángela; Saiz, Juan-Carlos; Sobrino, Francisco; Martín-Acebes, Miguel A.

    2011-01-01

    Valproic acid (VPA) is a short-chain fatty acid commonly used for treatment of neurological disorders. As VPA can interfere with cellular lipid metabolism, its effect on the infection of cultured cells by viruses of seven viral families relevant to human and animal health, including eight enveloped and four nonenveloped viruses, was analyzed. VPA drastically inhibited multiplication of all the enveloped viruses tested, including the zoonotic lymphocytic choriomeningitis virus and West Nile virus (WNV), while it did not affect infection by the nonenveloped viruses assayed. VPA reduced vesicular stomatitis virus infection yield without causing a major blockage of either viral RNA or protein synthesis. In contrast, VPA drastically abolished WNV RNA and protein synthesis, indicating that this drug can interfere the viral cycle at different steps of enveloped virus infection. Thus, VPA can contribute to an understanding of the crucial steps of viral maturation and to the development of future strategies against infections associated with enveloped viruses. PMID:21106740

  18. 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

  19. 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

  20. Maximized Posttest Contrasts: A Clarification.

    ERIC Educational Resources Information Center

    Hollingsworth, Holly

    1980-01-01

    A solution to some problems of maximized contrasts for analysis of variance situations when the cell sizes are unequal is offered. It is demonstrated that a contrast is maximized relative to the analysis used to compute the sum of squares between groups. Interpreting a maximum contrast is discussed. (Author/GK)

  1. Contrastive Analysis and Language Tendencies.

    ERIC Educational Resources Information Center

    Ree, Joe J.

    The purpose of this paper is to show that: (1) language universals have much to offer to students of contrastive linguistics, and (2) in order to make contrastive analysis more meaningful, one ought to go beyond cataloguing mere contrastive structure statements and capture underlying structural tendencies. Some characteristics of word order in…

  2. Meningococcal Infections

    MedlinePlus

    ... are a type of bacteria that cause serious infections. The most common infection is meningitis, which is an inflammation of the ... also cause other problems, including a serious bloodstream infection called sepsis. Meningococcal infections can spread from person ...

  3. 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. PMID:27626934

  4. 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

  5. Perceived contrast in complex images

    PubMed Central

    Haun, Andrew M.; Peli, Eli

    2013-01-01

    To understand how different spatial frequencies contribute to the overall perceived contrast of complex, broadband photographic images, we adapted the classification image paradigm. Using natural images as stimuli, we randomly varied relative contrast amplitude at different spatial frequencies and had human subjects determine which images had higher contrast. Then, we determined how the random variations corresponded with the human judgments. We found that the overall contrast of an image is disproportionately determined by how much contrast is between 1 and 6 c/°, around the peak of the contrast sensitivity function (CSF). We then employed the basic components of contrast psychophysics modeling to show that the CSF alone is not enough to account for our results and that an increase in gain control strength toward low spatial frequencies is necessary. One important consequence of this is that contrast constancy, the apparent independence of suprathreshold perceived contrast and spatial frequency, will not hold during viewing of natural images. We also found that images with darker low-luminance regions tended to be judged as having higher overall contrast, which we interpret as the consequence of darker local backgrounds resulting in higher band-limited contrast response in the visual system. PMID:24190908

  6. 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

  7. Reactive Infection Control Strategy for Control of New Delhi Metallo-β-Lactamase (NDM)-Producing Enterobacteriaceae Analyzed Using Whole-Genome Sequencing: Hits and Misses.

    PubMed

    Marimuthu, Kalisvar; Ng, Oon Tek; Khong, Wei Xin; Xia, Eryu; Teo, Yik-Ying; Ong, Rick Twee-Hee; Lye, David Chien; Chow, Angela Liping; Krishnan, Prabha; Ang, Brenda Sze

    2016-08-01

    Genetically distinct isolates of New Delhi metallo-β-lactamase (NDM)-producing Enterobacteriaceae were identified from the clinical cultures of 6 patients. Screening of shared-ward contacts identified 2 additional NDM-positive patients. Phylogenetic analysis proved that 1 contact was a direct transmission while the other was unrelated to the index, suggesting hidden routes of transmission. Infect Control Hosp Epidemiol 2016;37:987-990. PMID:27143092

  8. 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. PMID:27472555

  9. Prospecting gene therapy of implant infections.

    PubMed

    Costerton, William J; Montanaro, Lucio; Balaban, Naomi; Arciola, Carla Renata

    2009-09-01

    Infection still represents one of the most serious and ravaging complications associated with prosthetic devices. Staphylococci and enterococci, the bacteria most frequently responsible for orthopedic postsurgical and implant-related infections, express clinically relevant antibiotic resistance. The emergence of antibiotic-resistant bacteria and the slow progress in identifying new classes of antimicrobial agents have encouraged research into novel therapeutic strategies. The adoption of antisense or "antigene" molecules able to silence or knock-out bacterial genes responsible for their virulence is one possible innovative approach. Peptide nucleic acids (PNAs) are potential drug candidates for gene therapy in infections, by silencing a basic gene of bacterial growth or by tackling the antibiotic resistance or virulence factors of a pathogen. An efficacious contrast to bacterial genes should be set up in the first stages of infection in order to prevent colonization of periprosthesis tissues. Genes encoding bacterial factors for adhesion and colonization (biofilm and/or adhesins) would be the best candidates for gene therapy. But after initial enthusiasm for direct antisense knock-out or silencing of essential or virulence bacterial genes, difficulties have emerged; consequently, new approaches are now being attempted. One of these, interference with the regulating system of virulence factors, such as agr, appears particularly promising.

  10. Congenital Cytomegalovirus Infection.

    PubMed

    Bale, James F.; Miner, Lonnie; Petheram, Susan J.

    2002-05-01

    Intrauterine infection with cytomegalovirus (CMV), a betaherpesvirus, remains the most frequent congenital virus infection in many regions of the world. Although most CMV-infected newborns lack signs of CMV infection, approximately 10% have signs that can consist of low birth weight, jaundice, hepatosplenomegaly, skin rash, microcephaly, and chorioretinitis. Neonates with signs of CMV infection at birth have high rates of audiologic and neurodevelopmental sequelae. Although postnatal therapy with ganciclovir transiently reduces virus shedding and may lessen the audiologic consequences of CMV in some infected infants, additional strategies are needed to prevent congenital CMV disease and to improve the neurodevelopmental prognosis of infants infected with CMV in utero. Some cases of intrauterine infections can be prevented in susceptible women by avoiding contact with the urine or saliva of young children who may be shedding CMV. Vaccines against CMV remain in the experimental stages of development. Termination of pregnancy can be offered to women whose infants have evidence of intrauterine CMV infection and sonographic signs of central nervous system damage. Infants who survive symptomatic intrauterine infections have high rates of neurodevelopmental sequelae and require comprehensive evaluation and therapy through center and home-based early intervention programs. PMID:11931729

  11. Combined treatment of adenosine nucleoside inhibitor NITD008 and histone deacetylase inhibitor vorinostat represents an immunotherapy strategy to ameliorate West Nile virus infection

    PubMed Central

    Nelson, Jacob; Roe, Kelsey; Orillo, Beverly; Shi, Pei-Yong; Verma, Saguna

    2015-01-01

    West Nile virus (WNV), a member of the Flaviviridae family, is the leading cause of viral encephalitis in the United States. Despite efforts to control the spread of WNV, there has been an increase in the number of outbreaks and clinical cases with neurological problems. There are no antiviral compounds currently in trials for WNV. NITD008 is an adenosine analogue inhibitor that interrupts the RNA-dependent RNA polymerase of flaviviruses. While NITD008 has shown promise as an antiviral for dengue virus, the ability of this drug to block WNV replication is only limited to Vero cells. Neuroinflammation is also a major cause of the WNV-associated pathology, therefore we evaluated the effect of NITD008 and a newly characterized anti-inflammatory drug vorinostat (SAHA), a histone deacetylase inhibitor, on WNV replication and disease progression in a mouse model. When administered at 10 and 25 mg/kg at days 1 to 6 after WNV infection in C57BL/6 mice, NITD008 conferred complete protection from clinical symptoms and death, which correlated with reduced viral load in the serum and restriction of virus-CNS entry. Delay of NITD008 treatment to days 3 to 6 and days 5 to 9 after infection, when WNV replication was high in the periphery and brain, resulted in the gradual loss of protection against WNV infection. However, co-treatment with SAHA and NITD008 during the CNS phase of disease improved disease outcome significantly by reducing inflammation and neuronal death. Our results support potential synergistic effect of combination therapy of NITD008 with SAHA for the treatment of WNV encephalitis. PMID:26225754

  12. Combined treatment of adenosine nucleoside inhibitor NITD008 and histone deacetylase inhibitor vorinostat represents an immunotherapy strategy to ameliorate West Nile virus infection.

    PubMed

    Nelson, Jacob; Roe, Kelsey; Orillo, Beverly; Shi, Pei-Yong; Verma, Saguna

    2015-10-01

    West Nile virus (WNV), a member of the Flaviviridae family, is the leading cause of viral encephalitis in the United States. Despite efforts to control the spread of WNV, there has been an increase in the number of outbreaks and clinical cases with neurological problems. There are no antiviral compounds currently in trials for WNV. NITD008 is an adenosine analogue inhibitor that interrupts the RNA-dependent RNA polymerase of flaviviruses. Previous studies demonstrated NITD008 as a potent antiviral for dengue virus, however this drug was associated with preclinical toxicity. The ability of NITD008 to block WNV replication is only shown in Vero cells. Neuroinflammation is also a major cause of the WNV-associated pathology, therefore we evaluated the effect of NITD008 and a newly characterized anti-inflammatory drug vorinostat (SAHA), a histone deacetylase inhibitor, on WNV replication and disease progression in a mouse model. When administered at 10 and 25mg/kg at days 1-6 after WNV infection in C57BL/6 mice, NITD008 conferred complete protection from clinical symptoms and death, which correlated with reduced viral load in the serum and restriction of virus-CNS entry. Delay of NITD008 treatment to days 3-6 and days 5-9 after infection, when WNV replication was high in the periphery and brain, resulted in the gradual loss of protection against WNV infection. However, co-treatment with SAHA and NITD008 during the CNS phase of disease improved disease outcome significantly by reducing inflammation and neuronal death. Our results support potential synergistic effect of combination therapy of NITD008 with SAHA for the treatment of WNV encephalitis.

  13. Use of Six Sigma strategies to pull the line on central line-associated bloodstream infections in a neurotrauma intensive care unit.

    PubMed

    Loftus, Kelli; Tilley, Terry; Hoffman, Jason; Bradburn, Eric; Harvey, Ellen

    2015-01-01

    The creation of a consistent culture of safety and quality in an intensive care unit is challenging. We applied the Six Sigma Define-Measure-Analyze-Improve-Control (DMAIC) model for quality improvement (QI) to develop a long-term solution to improve outcomes in a high-risk neurotrauma intensive care unit. We sought to reduce central line utilization as a cornerstone in preventing central line-associated bloodstream infections (CLABSIs). This study describes the successful application of the DMAIC model in the creation and implementation of evidence-based quality improvement designed to reduce CLABSIs to below national benchmarks. PMID:25768963

  14. Pattern specificity of contrast adaptation

    PubMed Central

    Anstis, Stuart

    2014-01-01

    Contrast adaptation is specific to precisely localised edges, so that adapting to a flickering photograph makes one less sensitive to that same photograph, but not to similar photographs. When two low-contrast photos, A and B, are transparently superimposed, then adapting to a flickering high-contrast B leaves no net afterimage, but it makes B disappear from the A+B picture, which now simply looks like A. PMID:25165518

  15. Extreme Ultraviolet Phase Contrast Imaging

    SciTech Connect

    Denbeaux, Gregory; Garg, Rashi; Aquila, Andy; Barty, Anton; Goldberg, Kenneth; Gullikson, Eric; Liu, Yanwei; Wood, Obert

    2005-11-01

    The conclusions of this report are: (1) zone plate microscopy provides high resolution imaging of EUV masks; (2) using phase plates in the back focal plane of the objective lens can provide contrast mechanisms for measurement of the phase shift from defects on the mask; (3) the first high resolution EUV Zernike phase contrast images have been acquired; and (4) future work will include phase contrast mode in reflection from an EUV mask to directly measure the reflectivity and phase shift from defects.

  16. Infection Prevention in Transplantation.

    PubMed

    Pergam, Steven A

    2016-01-01

    The number of patients undergoing hematopoietic cell and solid organ transplantation are increasing every year, as are the number of centers both transplanting and caring for these patients. Improvements in transplant procedures, immunosuppressive regimens, and prevention of transplant-associated complications have led to marked improvements in survival in both populations. Infections remain one of the most important sources of excess morbidity and mortality in transplant, and therefore, infection prevention strategies are a critical element for avoiding these complications in centers caring for high-risk patients. This manuscript aims to provide an update of recent data on prevention of major healthcare-associated infections unique to transplantation, reviews the emergence of antimicrobial resistant infections, and discusses updated strategies to both identify and prevent transmission of these pathogens in transplant recipients.

  17. 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.

  18. 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.

  19. 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

    2016-01-01

    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. PMID:27245715

  20. 77 FR 4820 - Healthcare Infection Control Practices Advisory Committee (HICPAC)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-31

    ... Director, Division of Healthcare Quality Promotion regarding (1) the practice of healthcare infection control; (2) strategies for surveillance, prevention, and control of infections (e.g., nosocomial... HUMAN SERVICES Centers for Disease Control and Prevention Healthcare Infection Control...

  1. 77 FR 28392 - Healthcare Infection Control Practices Advisory Committee (HICPAC)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-14

    ... Director, Division of Healthcare Quality Promotion regarding 1) the practice of healthcare infection control; 2) strategies for surveillance, prevention, and control of infections (e.g., nosocomial... HUMAN SERVICES Centers for Disease Control and Prevention Healthcare Infection Control...

  2. Infective endocarditis.

    PubMed

    Holland, Thomas L; Baddour, Larry M; Bayer, Arnold S; Hoen, Bruno; Miro, Jose M; Fowler, Vance G

    2016-01-01

    Infective endocarditis (IE) is a rare, life-threatening disease that has long-lasting effects even among patients who survive and are cured. IE disproportionately affects those with underlying structural heart disease and is increasingly associated with health care contact, particularly in patients who have intravascular prosthetic material. In the setting of bacteraemia with a pathogenic organism, an infected vegetation may form as the end result of complex interactions between invading microorganisms and the host immune system. Once established, IE can involve almost any organ system in the body. The diagnosis of IE may be difficult to establish and a strategy that combines clinical, microbiological and echocardiography results has been codified in the modified Duke criteria. In cases of blood culture-negative IE, the diagnosis may be especially challenging, and novel microbiological and imaging techniques have been developed to establish its presence. Once diagnosed, IE is best managed by a multidisciplinary team with expertise in infectious diseases, cardiology and cardiac surgery. Antibiotic prophylaxis for the prevention of IE remains controversial. Efforts to develop a vaccine that targets common bacterial causes of IE are ongoing, but have not yet yielded a commercially available product. PMID:27582414

  3. 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

  4. 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 distinct…

  5. 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.

  6. Hookworm infection

    MedlinePlus

    Hookworm disease; Ground itch; Ancylostoma duodenale infection; Necator americanus infection; Parasitic infection - hookworm ... The last 2 types also occur in animals. Hookworm disease is common in the moist tropics and ...

  7. Vaginal Infections

    MedlinePlus

    ... Two common vaginal infections are bacterial vaginosis and yeast infections . Bacterial vaginosis (BV) happens when a certain ... increases the chances that you’ll get BV. Yeast infections happen when a fungus (a type of ...

  8. Staphylococcal Infections

    MedlinePlus

    ... of bacteria. There are over 30 types, but Staphylococcus aureus causes most staph infections (pronounced "staff infections"), including ... Some staph bacteria such as MRSA (methicillin-resistant Staphylococcus aureus) are resistant to certain antibiotics, making infections harder ...

  9. Whipworm infection

    MedlinePlus

    ... of the large intestine with a type of roundworm. ... Whipworm infection is caused by the roundworm Trichuris trichiura. It is a common infection that mainly affects children. Children may become infected if they swallow soil contaminated with whipworm ...

  10. Eye Infections

    MedlinePlus

    Your eyes can get infections from bacteria, fungi, or viruses. Eye infections can occur in different parts of the eye and can affect just one eye or both. Two common eye infections are Conjunctivitis - also known as pinkeye. Conjunctivitis is ...

  11. Bone Infections

    MedlinePlus

    ... of the body, bones can get infected. The infections are usually bacterial, but can also be fungal. ... bloodstream. People who are at risk for bone infections include those with diabetes, poor circulation, or recent ...

  12. Basic MR relaxation mechanisms and contrast agent design.

    PubMed

    De León-Rodríguez, Luis M; Martins, André F; Pinho, Marco C; Rofsky, Neil M; Sherry, A Dean

    2015-09-01

    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 detail the many important considerations when pursuing the design and use of MR contrast media. We 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 discuss the mechanisms involved in MR relaxation in the context of probe design strategies. A brief description of currently available contrast agents is accompanied by an in-depth discussion that highlights promising MRI contrast agents in the development of 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.

  13. Economic analysis of empiric versus diagnostic-driven strategies for immunocompromised patients with suspected fungal infections in the People's Republic of China.

    PubMed

    Mao, Ningying; Lesher, Beth; Liu, Qifa; Qin, Lei; Chen, Yixi; Gao, Xin; Earnshaw, Stephanie R; McDade, Cheryl L; Charbonneau, Claudie

    2016-01-01

    Invasive fungal infections (IFIs) require rapid diagnosis and treatment. A decision-analytic model was used to estimate total costs and survival associated with a diagnostic-driven (DD) or an empiric treatment approach in neutropenic patients with hematological malignancies receiving chemotherapy or autologous/allogeneic stem cell transplants in Shanghai, Beijing, Chengdu, and Guangzhou, the People's Republic of China. Treatment initiation for the empiric approach occurred after clinical suspicion of an IFI; treatment initiation for the DD approach occurred after clinical suspicion and a positive IFI diagnostic test result. Model inputs were obtained from the literature; treatment patterns and resource use were based on clinical opinion. Total costs were lower for the DD versus the empiric approach in Shanghai (¥3,232 vs ¥4,331), Beijing (¥3,894 vs ¥4,864), Chengdu, (¥4,632 vs ¥5,795), and Guangzhou (¥8,489 vs ¥9,795). Antifungal administration was lower using the DD (5.7%) than empiric (9.8%) approach, with similar survival rates. Results from one-way and probabilistic sensitivity analyses were most sensitive to changes in diagnostic test sensitivity and IFI incidence; the DD approach dominated the empiric approach in 88% of scenarios. These results suggest that a DD compared to an empiric treatment approach in the People's Republic of China may be cost saving, with similar overall survival in immunocompromised patients with suspected IFIs. PMID:27366099

  14. 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

  15. Economic analysis of empiric versus diagnostic-driven strategies for immunocompromised patients with suspected fungal infections in the People’s Republic of China

    PubMed Central

    Mao, Ningying; Lesher, Beth; Liu, Qifa; Qin, Lei; Chen, Yixi; Gao, Xin; Earnshaw, Stephanie R; McDade, Cheryl L; Charbonneau, Claudie

    2016-01-01

    Invasive fungal infections (IFIs) require rapid diagnosis and treatment. A decision-analytic model was used to estimate total costs and survival associated with a diagnostic-driven (DD) or an empiric treatment approach in neutropenic patients with hematological malignancies receiving chemotherapy or autologous/allogeneic stem cell transplants in Shanghai, Beijing, Chengdu, and Guangzhou, the People’s Republic of China. Treatment initiation for the empiric approach occurred after clinical suspicion of an IFI; treatment initiation for the DD approach occurred after clinical suspicion and a positive IFI diagnostic test result. Model inputs were obtained from the literature; treatment patterns and resource use were based on clinical opinion. Total costs were lower for the DD versus the empiric approach in Shanghai (¥3,232 vs ¥4,331), Beijing (¥3,894 vs ¥4,864), Chengdu, (¥4,632 vs ¥5,795), and Guangzhou (¥8,489 vs ¥9,795). Antifungal administration was lower using the DD (5.7%) than empiric (9.8%) approach, with similar survival rates. Results from one-way and probabilistic sensitivity analyses were most sensitive to changes in diagnostic test sensitivity and IFI incidence; the DD approach dominated the empiric approach in 88% of scenarios. These results suggest that a DD compared to an empiric treatment approach in the People’s Republic of China may be cost saving, with similar overall survival in immunocompromised patients with suspected IFIs. PMID:27366099

  16. Engineered porous scaffolds for periprosthetic infection prevention.

    PubMed

    Iviglia, Giorgio; Cassinelli, Clara; Bollati, Daniele; Baino, Francesco; Torre, Elisa; Morra, Marco; Vitale-Brovarone, Chiara

    2016-11-01

    Periprosthetic infection is a consequence of implant insertion procedures and strategies for its prevention involve either an increase in the rate of new bone formation or the release of antibiotics such as vancomycin. In this work we combined both strategies and developed a novel, multifunctional three-dimensional porous scaffold that was produced using hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP), coupled with a pectin (PEC)-chitosan (CHIT) polyelectrolyte (PEI), and loaded with vancomycin (VCA). By this approach, a controlled vancomycin release was achieved and serial bacterial dilution test demonstrated that, after 1week, the engineered construct still inhibits the bacterial growth. Degradation tests show an excellent behavior in a physiological and acidic environment (<10% of mass loss). Furthermore, the PEI coating shows an anti-inflammatory response, and good cell proliferation and migration were demonstrated in vitro using osteoblast SAOS-2 cell line. This new engineered construct exhibits excellent properties both as an antibacterial material and as a stimulator of bone formation, which makes it a good candidate to contrast periprosthetic infection. PMID:27524071

  17. 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.

  18. Visual maladaptation in contrast domain

    NASA Astrophysics Data System (ADS)

    Pajak, Dawid; Cadík, Martin; Aydin, Tunç O.; Myszkowski, Karol; Seidel, Hans-Peter

    2010-02-01

    In this work we simulate the effect of the human eye's maladaptation to visual perception over time through a supra-threshold contrast perception model that comprises adaptation mechanisms. Specifically, we attempt to visualize maladapted vision on a display device. Given the scene luminance, the model computes a measure of perceived multi-scale contrast by taking into account spatially and temporally varying contrast sensitivity in a maladapted state, which is then processed by the inverse model and mapped to a desired display's luminance assuming perfect adaptation. Our system simulates the effect of maladaptation locally, and models the shifting of peak spatial frequency sensitivity in maladapted vision in addition to the uniform decrease in contrast sensitivity among all frequencies. Through our GPU implementation we demonstrate the visibility loss of scene details due to maladaptation over time at an interactive speed.

  19. 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. PMID:25244535

  20. 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.

  1. Productive replication of nephropathogenic infectious bronchitis virus in peripheral blood monocytic cells, a strategy for viral dissemination and kidney infection in chickens.

    PubMed

    Reddy, Vishwanatha R A P; Trus, Ivan; Desmarets, Lowiese M B; Li, Yewei; Theuns, Sebastiaan; Nauwynck, Hans J

    2016-01-01

    In the present study, the replication kinetics of nephropathogenic (B1648) and respiratory (Massachusetts-M41) IBV strains were compared in vitro in respiratory mucosa explants and blood monocytes (KUL01(+) cells), and in vivo in chickens to understand why some IBV strains have a kidney tropism. B1648 was replicating somewhat better than M41 in the epithelium of the respiratory mucosa explants and used more KUL01(+) cells to penetrate the deeper layers of the respiratory tract. B1648 was productively replicating in KUL01(+) monocytic cells in contrast with M41. In B1648 inoculated animals, 10(2.7-6.8) viral RNA copies/100 mg were detected in tracheal secretions at 2, 4, 6, 8, 10 and 12 days post inoculation (dpi), 10(2.4-4.5) viral RNA copies/mL in plasma at 2, 4, 6, 8, 10 and 12 dpi and 10(1.8-4.4) viral RNA copies/10(6) mononuclear cells in blood at 2, 4, 6 and 8 dpi. In M41 inoculated animals, 10(2.6-7.0) viral RNA copies/100 mg were detected in tracheal secretions at 2, 4, 6, 8 and 10 dpi, but viral RNA was not demonstrated in plasma and mononuclear cells (except in one chicken at 6 dpi). Infectious virus was detected only in plasma and mononuclear cells of the B1648 group. At euthanasia (12 dpi), viral RNA and antigen positive cells were detected in lungs, liver, spleen and kidneys of only the B1648 group and in tracheas of both the B1648 and M41 group. In conclusion, only B1648 can easily disseminate to internal organs via a cell-free and -associated viremia with KUL01(+) cells as important carrier cells. PMID:27412035

  2. Sternal mycobacterial infections

    PubMed Central

    Yuan, Shi-Min

    2016-01-01

    Sternal mycobacterial infections are rare. Due to the rarity, its clinical characteristics, diagnoses, and regular management strategies are still scanty. A total of 76 articles on this topic were obtained by a comprehensive literature collection. The clinical features, diagnosis, management strategies and prognosis were carefully analyzed. There were totally 159 patients including 152 (95%) cases of tuberculosis (TB) and seven (5%) cases of non-TB sternal infections. Sternal mycobacterial infections can be categorized into three types: Primary, secondary, and postoperative, according to the pathogenesis; and categorized into isolated, peristernal, and multifocal, according to the extent of the lesions. Microbiological investigation is more sensitive than medical imaging and Mantoux tuberculin skin test in the diagnosis of sternal infections. Most patients show good responses to the standard four-drug regimen and a surgical intervention was necessary in 28.3% patients. The prognoses of the patients are good with a very low mortality. A delayed diagnosis of sternal mycobacterial infections may bring about recurrent sternal infections and sustained incurability. An early diagnosis and prompt antibiotic regimens may significantly improve the patients' outcomes. PMID:27168857

  3. Increased eligibility for treatment of chronic hepatitis C infection with shortened duration of therapy: Implications for access to care and elimination strategies in Canada

    PubMed Central

    Borgia, Sergio M; Rowaiye, Adenike

    2015-01-01

    BACKGROUND: All oral, highly effective direct-acting antiviral combinations, such as sofosbuvir-ledipasvir, have recently been licensed in Canada but cost as much as $67,000 for a 12-week course of therapy, representing a major economic barrier to predominately single-payer health care systems such as that found in Ontario. In hepatitis C virus (HCV) genotype 1 noncirrhotic patients with a baseline viral load of <6×106 IU/mL, treatment with sofosbuvir-ledipasvir can be shortened to eight weeks without compromising ≥95% efficacy. The number of HCV-infected patients in Ontario eligible for shortened therapy, and the associated cost savings, are unknown. The authors propose that treating every patient with shortened therapy, regardless of baseline viral load, would lead to significant public cost savings and collateral efficiencies, enabling increased HCV treatment capacity and cure. METHODS: The present study designed a three-part model to investigate the cost of cure per patient and cost savings per patient under three eligibility pathways: conservative, permissive and ideal. In the conservative model, every patient is treated for 12 weeks regardless of baseline viral load, whereas in the permissive model, patients with a baseline viral load <6×106 IU/mL are treated for eight weeks. In the ideal model, every patient receives eight weeks of therapy regardless of baseline viral load. Relapsed patients are retreated for 12 weeks. Data obtained from the Ontario Public Health Laboratory were used to validate the model and generate the outcomes. RESULTS: In Ontario, 75.34% of HCV genotype 1 patients had a baseline viral load of <6×106 IU/mL and were eligible for shortened therapy. The cost of cure per patient in the ideal model was $47,328.44, representing a 29% reduction in the cost of curative therapy and 3.5 weeks of shortened treatment duration compared with the conservative model. The ideal model generated a cost savings per patient of $3,855.17 (8% reduction in

  4. Efficient strategy for constructing duck enteritis virus-based live attenuated vaccine against homologous and heterologous H5N1 avian influenza virus and duck enteritis virus infection.

    PubMed

    Zou, Zhong; Hu, Yong; Liu, Zhigang; Zhong, Wei; Cao, Hangzhou; Chen, Huanchun; Jin, Meilin

    2015-04-16

    Duck is susceptible to many pathogens, such as duck hepatitis virus, duck enteritis virus (DEV), duck tembusu virus, H5N1 highly pathogenic avian influenza virus (HPAIV) in particular. With the significant role of duck in the evolution of H5N1 HPAIV, control and eradication of H5N1 HPAIV in duck through vaccine immunization is considered an effective method in minimizing the threat of a pandemic outbreak. Consequently, a practical strategy to construct a vaccine against these pathogens should be determined. In this study, the DEV was examined as a candidate vaccine vector to deliver the hemagglutinin (HA) gene of H5N1, and its potential as a polyvalent vaccine was evaluated. A modified mini-F vector was inserted into the gB and UL26 gene junction of the attenuated DEV vaccine strain C-KCE genome to generate an infectious bacterial artificial chromosome (BAC) of C-KCE (vBAC-C-KCE). The HA gene of A/duck/Hubei/xn/2007 (H5N1) was inserted into the C-KCE genome via the mating-assisted genetically integrated cloning (MAGIC) to generate the recombinant vector pBAC-C-KCE-HA. A bivalent vaccine C-KCE-HA was developed by eliminating the BAC backbone. Ducks immunized with C-KCE-HA induced both the cross-reactive antibodies and T cell response against H5. Moreover, C-KCE-HA-immunized ducks provided rapid and long-lasting protection against homologous and heterologous HPAIV H5N1 and DEV clinical signs, death, and primary viral replication. In conclusion, our BAC-C-KCE is a promising platform for developing a polyvalent live attenuated vaccine.

  5. 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.

  6. 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

  7. Polycatechol Nanoparticle MRI Contrast Agents.

    PubMed

    Li, Yiwen; Huang, Yuran; Wang, Zhao; Carniato, Fabio; Xie, Yijun; Patterson, Joseph P; Thompson, Matthew P; Andolina, Christopher M; Ditri, Treffly B; Millstone, Jill E; Figueroa, Joshua S; Rinehart, Jeffrey D; Scadeng, Miriam; Botta, Mauro; Gianneschi, Nathan C

    2016-02-01

    Amphiphilic triblock copolymers containing Fe(III) -catecholate complexes formulated as spherical- or cylindrical-shaped micellar nanoparticles (SMN and CMN, respectively) are described as new T1-weighted agents with high relaxivity, low cytotoxicity, and long-term stability in biological fluids. Relaxivities of both SMN and CMN exceed those of established gadolinium chelates across a wide range of magnetic field strengths. Interestingly, shape-dependent behavior is observed in terms of the particles' interactions with HeLa cells, with CMN exhibiting enhanced uptake and contrast via magnetic resonance imaging (MRI) compared with SMN. These results suggest that control over soft nanoparticle shape will provide an avenue for optimization of particle-based contrast agents as biodiagnostics. The polycatechol nanoparticles are proposed as suitable for preclinical investigations into their viability as gadolinium-free, safe, and effective imaging agents for MRI contrast enhancement. PMID:26681255

  8. Segment aberration effects on contrast.

    PubMed

    Crossfield, Ian J; Troy, Mitchell

    2007-07-20

    High-contrast imaging, particularly the direct detection of extrasolar planets, is a major science driver for the next generation of telescopes. This science requires the suppression of scattered starlight at extremely high levels and that telescopes be correctly designed today to meet these stringent requirements in the future. The challenge increases in systems with complicated aperture geometries such as obscured, segmented telescopes. Such systems can also require intensive modeling and simulation efforts in order to understand the trade-offs between different optical parameters. The feasibility and development of a contrast prediction tool for use in the design and systems engineering of these telescopes is described. The performance of a particular starlight suppression system on a large segmented telescope is described analytically. These analytical results and the results of a contrast predictor are then compared with the results of a full wave-optics simulation. PMID:17609697

  9. Microbiome in HIV infection

    PubMed Central

    Salas, January T.; Chang, Theresa L.

    2014-01-01

    HIV primary infection occurs at mucosa tissues, suggesting an intricate interplay between microbiome and HIV infection. Recent advanced technologies of high-throughput sequencing and bioinformatics allow researchers to explore nonculturable microbes including bacteria, virus and fungi and their association with diseases. HIV/SIV infection is associated with microbiome shifts and immune activation that may affect the outcome of disease progression. Similarly, altered microbiome and inflammation are associated with increased risks of HIV acquisition, suggesting the role of microbiome in HIV transmission. In this review, we will focus on microbiome in HIV infection at various mucosal compartments. Understanding the relationship between microbiome and HIV may offer insights into development of better strategies for HIV prevention and treatment. PMID:25439273

  10. Hepatitis C Virus Infection in HIV-infected Patients.

    PubMed

    Sulkowski, Mark S.

    2001-10-01

    The hepatitis C virus (HCV) is a spherical enveloped RNA virus of the Flaviviridae family, classified within the Hepacivirus genus. Since its discovery in 1989, HCV has been recognized as a major cause of chronic hepatitis and hepatic fibrosis that progresses in some patients to cirrhosis and hepatocellular carcinoma. In the United States, approximately 4 million people have been infected with HCV, and 10,000 HCV-related deaths occur each year. Due to shared routes of transmission, HCV and HIV co-infection are common, affecting approximately one third of all HIV-infected persons in the United States. In addition, HIV co-infection is associated with higher HCV RNA viral load and a more rapid progression of HCV-related liver disease, leading to an increased risk of cirrhosis. HCV infection may also impact the course and management of HIV disease, particularly by increasing the risk of antiretroviral drug-induced hepatotoxicity. Thus, chronic HCV infection acts as an opportunistic disease in HIV-infected persons because the incidence of infection is increased and the natural history of HCV infection is accelerated in co-infected persons. Strategies to prevent primary HCV infection and to modify the progression of HCV-related liver disease are urgently needed among HIV/HCV co-infected individuals.

  11. Hepatitis C virus infection in HIV-infected patients.

    PubMed

    Sulkowski, Mark S

    2007-10-01

    The hepatitis C virus (HCV) is a spherical enveloped RNA virus of the Flaviviridae family, classified within the Hepacivirus genus. Since its discovery in 1989, HCV has been recognized as a major cause of chronic hepatitis and hepatic fibrosis that progresses in some patients to cirrhosis and hepatocellular carcinoma. In the United States, approximately 4 million people have been infected with HCV, and 10,000 HCVrelated deaths occur each year. Due to shared routes of transmission, HCV and HIV co-infection are common, affecting approximately one third of all HIV-infected persons in the United States. In addition, HIV co-infection is associated with higher HCV RNA viral load and a more rapid progression of HCV-related liver disease, leading to an increased risk of cirrhosis. HCV infection may also impact the course and management of HIV disease, particularly by increasing the risk of antiretroviral drug-induced hepatotoxicity. Thus, chronic HCV infection acts as an opportunistic disease in HIV-infected persons because the incidence of infection is increased and the natural history of HCV infection is accelerated in co-infected persons. Strategies to prevent primary HCV infection and to modify the progression of HCV-related liver disease are urgently needed among HIV/HCV co-infected individuals.

  12. 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,…

  13. Infection and Cardiovascular Disease

    ClinicalTrials.gov

    2016-02-17

    Cardiovascular Diseases; Coronary Disease; Cerebrovascular Accident; Heart Diseases; Myocardial Infarction; Infection; Chlamydia Infections; Cytomegalovirus Infections; Helicobacter Infections; Atherosclerosis

  14. 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 intelligibi