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PubMed Central (PMC3 - NLM DTD) (2,707,874 recursos)
Archive of life sciences journal literature at the U.S. National Institutes of Health (NIH), developed and managed by NIH's National Center for Biotechnology Information (NCBI) in the National Library of Medicine (NLM).

PLoS Neglected Tropical Diseases

Mostrando recursos 1 - 20 de 1,091

1. Nematode-Induced Interference with Vaccination Efficacy Targets Follicular T Helper Cell Induction and Is Preserved after Termination of Infection - Haben, Irma; Hartmann, Wiebke; Breloer, Minka
One-third of the human population is infected with parasitic worms. To avoid being eliminated, these parasites actively dampen the immune response of their hosts. This immune modulation also suppresses immune responses to third-party antigens such as vaccines. Here, we used Litomosoides sigmodontis-infected BALB/c mice to analyse nematode-induced interference with vaccination. Chronic nematode infection led to complete suppression of the humoral response to thymus-dependent vaccination. Thereby the numbers of antigen-specific B cells as well as the serum immunoglobulin (Ig) G titres were reduced. TH2-associated IgG1 and TH1-associated IgG2 responses were both suppressed. Thus, nematode infection did not bias responses towards a...

2. Strong Type 1, but Impaired Type 2, Immune Responses Contribute to Orientia tsutsugamushi-Induced Pathology in Mice - Soong, Lynn; Wang, Hui; Shelite, Thomas R.; Liang, Yuejin; Mendell, Nicole L.; Sun, Jiaren; Gong, Bin; Valbuena, Gustavo A.; Bouyer, Donald H.; Walker, David H.
Scrub typhus is a neglected, but important, tropical disease, which puts one-third of the world's population at risk. The disease is caused by Orientia tsutsugamushi, an obligately intracellular Gram-negative bacterium. Dysregulation in immune responses is known to contribute to disease pathogenesis; however, the nature and molecular basis of immune alterations are poorly defined. This study made use of a newly developed murine model of severe scrub typhus and focused on innate regulators and vascular growth factors in O. tsutsugamushi-infected liver, lungs and spleen. We found no activation or even reduction in base-line expression for multiple molecules (IL-7, IL-4, IL-13, GATA3,...

3. Comparison of Biotinylated Monoclonal and Polyclonal Antibodies in an Evaluation of a Direct Rapid Immunohistochemical Test for the Routine Diagnosis of Rabies in Southern Africa - Coetzer, Andre; Sabeta, Claude T.; Markotter, Wanda; Rupprecht, Charles E.; Nel, Louis H.
The major etiological agent of rabies, rabies virus (RABV), accounts for tens of thousands of human deaths per annum. The majority of these deaths are associated with rabies cycles in dogs in resource-limited countries of Africa and Asia. Although routine rabies diagnosis plays an integral role in disease surveillance and management, the application of the currently recommended direct fluorescent antibody (DFA) test in countries on the African and Asian continents remains quite limited. A novel diagnostic assay, the direct rapid immunohistochemical test (dRIT), has been reported to have a diagnostic sensitivity and specificity equal to that of the DFA test...

4. RNAi Dynamics in Juvenile Fasciola spp. Liver Flukes Reveals the Persistence of Gene Silencing In Vitro - McVeigh, Paul; McCammick, Erin M.; McCusker, Paul; Morphew, Russell M.; Mousley, Angela; Abidi, Abbas; Saifullah, Khalid M.; Muthusamy, Raman; Gopalakrishnan, Ravikumar; Spithill, Terry W.; Dalton, John P.; Brophy, Peter M.; Marks, Nikki J.; Maule, Aaron G.
RNA interference (RNAi) is a method for selectively silencing (or reducing expression of) mRNA transcripts, an approach which can be used to interrogate the function of genes and proteins, and enables the validation of potential targets for anthelmintic drugs or vaccines, by investigating the impact of silencing a particular gene on parasite survival or behaviour. This study focuses on liver fluke parasites, which cause serious disease in both humans and animals. We have only a handful of drugs with which to treat these infections, to which flukes are developing resistance, and no anti-fluke vaccines have yet been developed. New options...

5. Evaluation of Biochemical, Hematological and Parasitological Parameters of Protein-Deficient Hamsters Infected with Ancylostoma ceylanicum - Pacanaro, Carina P.; Dias, Sílvia R.; Serafim, Luciana R.; Costa, Mariana P.; Aguilar, Edenil; Paes, Paulo R.; Alvarez-Leite, Jacqueline I.; Rabelo, Élida M.
Hookworm's infection is a health problem that affects areas of poverty worldwide. Nutritional diseases, including dietary protein deficiency are also prevalent in those areas. It is well known that nutritional status can influence parasite infection, reducing host responses to infection. However, the influence of nutritional status and Hookworm's infection is less explored. Our goal was to study the consequences of coexistence of low-protein malnutrition and Hookworm's infection in hamsters that are good models of this infection. For that, we established a model of protein malnutrition by feeding hamsters on standard diet or isocaloric, low-protein diet for 50 days. Hamsters fed...

6. Crimean-Congo Hemorrhagic Fever Virus Clades V and VI (Europe 1 and 2) in Ticks in Kosovo, 2012 - Sherifi, Kurtesh; Cadar, Daniel; Muji, Skender; Robaj, Avni; Ahmeti, Salih; Jakupi, Xhevat; Emmerich, Petra; Krüger, Andreas
Despite being a small country, Kosovo represents one of the few foci of Crimean-Congo hemorrhagic fever (CCHF) in Europe. The distribution of Kosovar tick vectors and the evolution of CCHF virus in ticks are both as yet unknown. A better description of the extent and the genetic diversity of CCHFV in ticks from endemic settings is essential, in order to be controlled. We investigated the 2012 distribution of Kosovar ticks alongside the prevalence and the phylogeography of tick-derived CCHFV. Hyalomma marginatum dominated in the endemic municipalities with 90.2% versus 24.3% in the non-endemic regions. Of 1,102 tested ticks, 40 (3.6%)...

7. Cathepsin B in Antigen-Presenting Cells Controls Mediators of the Th1 Immune Response during Leishmania major Infection - Gonzalez-Leal, Iris J.; Röger, Bianca; Schwarz, Angela; Schirmeister, Tanja; Reinheckel, Thomas; Lutz, Manfred B.; Moll, Heidrun
Resistance and susceptibility to Leishmania major infection in the murine model is determined by the capacity of the host to mount either a protective Th1 response or a Th2 response associated with disease progression. Previous reports involving the use of cysteine cathepsin inhibitors indicated that cathepsins B (Ctsb) and L (Ctsl) play important roles in Th1/Th2 polarization during L. major infection in both susceptible and resistant mouse strains. Although it was hypothesized that these effects are a consequence of differential patterns of antigen processing, the mechanisms underlying these differences were not further investigated. Given the pivotal roles that dendritic cells...

8. Dynamics of Japanese Encephalitis Virus Transmission among Pigs in Northwest Bangladesh and the Potential Impact of Pig Vaccination - Khan, Salah Uddin; Salje, Henrik; Hannan, A.; Islam, Md. Atiqul; Bhuyan, A. A. Mamun; Islam, Md. Ariful; Rahman, M. Ziaur; Nahar, Nazmun; Hossain, M. Jahangir; Luby, Stephen P.; Gurley, Emily S.
Japanese encephalitis (JE) virus infection can cause severe neurological disease in man. More JE cases are seen in northwestern districts in Bangladesh. Pigs are the most common amplifying host of the virus and can act as a potential environmental source. We conducted a comprehensive census of pigs in three JE endemic districts and tested a sample of them for evidence of previous JEV infection. We built a compartmental model to describe JEV transmission dynamics in this region and to estimate the potential impact of pig vaccination. We identified 11,364 pigs in our study area, mostly raised in backyards. About 30%...

9. Strongyloides stercoralis: Systematic Review of Barriers to Controlling Strongyloidiasis for Australian Indigenous Communities - Miller, Adrian; Smith, Michelle L.; Judd, Jenni A.; Speare, Rick
Strongyloides stercoralis, a nematode parasite, has a well-documented history of infecting human hosts in tropic and subtropic regions mainly through skin contact with inhabited soil. The result is strongyloidiasis, a human parasitic disease, with a unique cycle of auto-infection contributing to a variety of symptoms, of which, hyper-infection causing fatality may occur. In Australia, Indigenous community members often located in rural and remote settings, are exposed to and infected with strongyloides. Previous researchers report strongyloidiasis as a recurrent health issue for Indigenous Australians. This is a systematic review to determine the barriers to control for this pernicious pathogen. Barriers to...

10. Development of a Rapid Agglutination Latex Test for Diagnosis of Enteropathogenic and Enterohemorrhagic Escherichia coli Infection in Developing World: Defining the Biomarker, Antibody and Method - Rocha, Letícia B.; Santos, Anna R. R.; Munhoz, Danielle D.; Cardoso, Lucas T. A.; Luz, Daniela E.; Andrade, Fernanda B.; Horton, Denise S. P. Q.; Elias, Waldir P.; Piazza, Roxane M. F.
A rapid and low-cost diagnosis for EPEC/EHEC infections is extremely required considering their global prevalence, the severity of the diseases associated with them, and the fact that the use of antibiotics to treat EHEC infections can be harmful. For EHEC, the detection of Stx toxins has already been developed, but for EPEC, an internationally recognized standard diagnostic test is lacking. Thus, the approach for their rapid detection in this study was the use of the secreted proteins EspA and/or EspB, since they are the major secreted proteins in both pathogens. EspB was defined as a biomarker and its corresponding monoclonal...

11. Public Awareness and Knowledge of Neglected Tropical Diseases (NTDs) Control Activities in Abuja, Nigeria - Olamiju, Olatunwa J.; Olamiju, Francisca O.; Adeniran, Adebiyi A.; Mba, Ifeanyi C.; Ukwunna, Chidera C.; Okoronkwo, Chukwu; Ekpo, Uwem F.
The need to engage the public in Neglected Tropical Diseases (NTDs) control activities has become imperative in the context of morbidity reduction through preventive chemotherapy and community participation. Therefore, a survey was conducted among the general public to assess their knowledge and awareness of NTDs control activities in Nigeria. A simple questionnaire was administered to the general public attending a job fair in Abuja, Nigeria. Of the 461 respondents, a significant proportion 337 (73.1%) have heard of NTD before, but only 291 (63.1%) have good knowledge about NTDs. However, among the specific NTDs, only the control of onchocerciasis (50.8%) was...

12. Where the Road Ends, Yaws Begins? The Cost-effectiveness of Eradication versus More Roads - Fitzpatrick, Christopher; Asiedu, Kingsley; Jannin, Jean
A disabling and disfiguring disease that “begins where the road ends” (among poor and isolated communities), yaws is targeted by WHO for eradication by the year 2020. The global campaign is not yet financed. We provide benchmarks for the cost and health effects of global yaws eradication, based on evidence from four yaws eradication pilot sites and other mass treatment campaigns. We suggest that a global yaws eradication campaign could be established with a relatively modest investment in the period 2015–2020 — as little as US$ 100 million in the 12 known endemic countries. Eradication would cost about US$ 26...

13. Use of Humanised Rat Basophilic Leukaemia Cell Line RS-ATL8 for the Assessment of Allergenicity of Schistosoma mansoni Proteins - Wan, Daniel; Ludolf, Fernanda; Alanine, Daniel G. W.; Stretton, Owen; Ali Ali, Eman; Al-Barwary, Nafal; Wang, Xiaowei; Doenhoff, Michael J.; Mari, Adriano; Fitzsimmons, Colin M.; Dunne, David W.; Nakamura, Ryosuke; Oliveira, Guilherme C.; Alcocer, Marcos J. C.; Falcone, Franco H.
Infection with parasitic helminths is characterised by a marked elevation of total and parasite-specific Immunoglobulin E (IgE). It is widely believed that this IgE response has evolved to protect hosts against large metazoan parasites. Such a protective function has been well characterised in particular against members of the genus Schistosoma. However, with a few notable exceptions, the molecular targets of the IgE response and the downstream immunological mechanisms leading to host protection are not well understood. The molecular targets of a specific IgE response are by definition called allergens. While almost 3,000 different allergens, contained in e.g. plant pollen or...

14. Impact of Leishmania mexicana Infection on Dendritic Cell Signaling and Functions - Contreras, Irazú; Estrada, José A.; Guak, Hannah; Martel, Caroline; Borjian, Alborz; Ralph, Benjamin; Shio, Marina T.; Fournier, Sylvie; Krawczyk, Connie M.; Olivier, Martin
Leishmania parasites have the ability to modify macrophage signaling pathways in order to survive and multiply within its mammalian host. They are also known to invade other cells including neutrophils, fibroblasts and dendritic cells (DCs). DCs have an important role in immunity as the link between innate and adaptive immunity, necessary for the development of an effective response; however, the impact of Leishmania mexicana infection on DCs has been poorly studied. Herein, we report that Leishmania infection rapidly induced DC protein tyrosine phosphatases activity, leading to MAP kinases inactivation. In line with this, L. mexicana was found to decrease the...

15. Evaluation of the Murine Immune Response to Xenopsylla cheopis Flea Saliva and Its Effect on Transmission of Yersinia pestis - Bosio, Christopher F.; Viall, Austin K.; Jarrett, Clayton O.; Gardner, Donald; Rood, Michael P.; Hinnebusch, B. Joseph
The saliva of blood-feeding arthropods contains a variety of components that prevent blood clotting and interfere with the immune system of the vertebrate host. These properties have been shown to enhance or inhibit the transmission of different pathogens transmitted by arthropods. Yersinia pestis, the bacterial agent of plague, is maintained in nature by flea to rodent transmission cycles. Most rodents live in close association with fleas and are constantly being bitten by them, but the influence this has on plague transmission is unknown - previous studies used laboratory animals which have never experienced a flea bite. We found that flea...

16. Genotyping of Burkholderia mallei from an Outbreak of Glanders in Bahrain Suggests Multiple Introduction Events - Scholz, Holger C.; Pearson, Talima; Hornstra, Heidie; Projahn, Michaela; Terzioglu, Rahime; Wernery, Renate; Georgi, Enrico; Riehm, Julia M.; Wagner, David M.; Keim, Paul S.; Joseph, Marina; Johnson, Bobby; Kinne, Joerg; Jose, Shanti; Hepp, Crystal M.; Witte, Angela; Wernery, Ulrich
Glanders is a disease of antiquity, recognized as a malady of equines by Hippocrates and Aristotle. The causative agent, Burkholderia mallei, is currently feared as a potential biological weapon and has been used as such in the American Civil War and both World Wars to cripple equine military components. In the more economically developed countries, glanders has been eradicated through large scale culling. As a result, our understanding of transmission dynamics and networks is limited. However, regions of endemicity still exist in Asia, the Middle-East, Africa, and South America where it infects solipeds and camels. These areas provide reservoirs for...

17. The NTDs and Vaccine Diplomacy in Latin America: Opportunities for United States Foreign Policy - Hotez, Peter J.

18. Eradication of Yaws: Historical Efforts and Achieving WHO's 2020 Target - Asiedu, Kingsley; Fitzpatrick, Christopher; Jannin, Jean

19. The Spatial Dynamics of Dengue Virus in Kamphaeng Phet, Thailand - Bhoomiboonchoo, Piraya; Gibbons, Robert V.; Huang, Angkana; Yoon, In-Kyu; Buddhari, Darunee; Nisalak, Ananda; Chansatiporn, Natkamol; Thipayamongkolgul, Mathuros; Kalanarooj, Siripen; Endy, Timothy; Rothman, Alan L.; Srikiatkhachorn, Anon; Green, Sharone; Mammen, Mammen P.; Cummings, Derek A.; Salje, Henrik
Transmission of dengue virus has long been studied in Kamphaeng Phet, Northern Thailand, but how cases are related in time and space is still unclear, as is the role of human movement in generating these patterns. Because of these knowledge gaps, public health officials cannot make educated decisions on how to target vector control interventions and mechanisms of virus dispersal are not known. We mapped the homes of dengue cases admitted to the main hospital in the province capital from 1994–2008 and quantified the spatial correlation between them. We found an almost three times greater chance that cases from the...

20. Co-infection of Long-Term Carriers of Plasmodium falciparum with Schistosoma haematobium Enhances Protection from Febrile Malaria: A Prospective Cohort Study in Mali - Doumbo, Safiatou; Tran, Tuan M.; Sangala, Jules; Li, Shanping; Doumtabe, Didier; Kone, Younoussou; Traoré, Abdrahamane; Bathily, Aboudramane; Sogoba, Nafomon; Coulibaly, Michel E.; Huang, Chiung-Yu; Ongoiba, Aissata; Kayentao, Kassoum; Diallo, Mouctar; Dramane, Zongo; Nutman, Thomas B.; Crompton, Peter D.; Doumbo, Ogobara; Traore, Boubacar
The parasitic diseases malaria and schistosomiasis are tremendous public health burdens, each affecting over 200 million people worldwide with substantial geographic overlap in sub-Saharan Africa. Understanding how schistosomiasis influences the human immune response to Plasmodium, the agent of malaria, can be important for developing effective malaria vaccines. Past studies have tried to determine if infection with Schistosoma haematobium, which causes urinary schistosomiasis, affects the number of febrile attacks from malaria caused by Plasmodium falciparum in communities where the diseases overlap, but the findings have been inconsistent. Here, we examined 616 healthy people from a village in Mali for symptomless infections...

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