oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Proteomic and Immunochemical Characterization of Glutathione Transferase as a New Allergen of the Nematode Ascaris lumbricoides  [PDF]
Nathalie Acevedo, Jens Mohr, Josefina Zakzuk, Martin Samonig, Peter Briza, Anja Erler, Anna Pomés, Christian G. Huber, Fatima Ferreira, Luis Caraballo
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0078353
Abstract: Helminth infections and allergy have evolutionary and clinical links. Infection with the nematode Ascaris lumbricoides induces IgE against several molecules including invertebrate pan-allergens. These antibodies influence the pathogenesis and diagnosis of allergy; therefore, studying parasitic and non-parasitic allergens is essential to understand both helminth immunity and allergy. Glutathione transferases (GSTs) from cockroach and house dust mites are clinically relevant allergens and comparative studies between them and the GST from A. lumbricoides (GSTA) are necessary to evaluate their allergenicity. We sought to analyze the allergenic potential of GSTA in connection with the IgE response to non-parasitic GSTs. IgE to purified GSTs from Ascaris (nGSTA and rGSTA), house dust mites (rDer p 8, nBlo t 8 and rBlo t 8), and cockroach (rBla g 5) was measured by ELISA in subjects from Cartagena, Colombia. Also, multidimensional proteomic approaches were used to study the extract of A. lumbricoides and investigate the existence of GST isoforms. We found that among asthmatics, the strength of IgE levels to GSTA was significantly higher than to mite and cockroach GSTs, and there was a strong positive correlation between IgE levels to these molecules. Specific IgE to GSTA was found in 13.2% of controls and 19.5% of asthmatics. In addition nGSTA induced wheal and flare in skin of sensitized asthmatics indicating that it might be of clinical relevance for some patients. Frequency and IgE levels to GSTA were higher in childhood and declined with age. At least six GST isoforms in A. lumbricoides bind human IgE. Four isoforms were the most abundant and several amino acid substitutions were found, mainly on the N-terminal domain. In conclusion, a new allergenic component of Ascaris has been discovered; it could have clinical impact in allergic patients and influence the diagnosis of mite and cockroach allergy in tropical environments.
Prevalence and intensity of infections of Ascaris lumbricoides and Trichuris trichiura and associated socio-demographic variables in four rural Honduran communities
Smith, HM;DeKaminsky, RG;Niwas, S;Soto, RJ;Jolly, PE;
Memórias do Instituto Oswaldo Cruz , 2001, DOI: 10.1590/S0074-02762001000300004
Abstract: between january and march 1998, a cross-sectional survey was carried out in four rural communities in honduras, central america. we examined the prevalence and intensity of ascaris lumbricoides and trichuris trichiura infections among 240 fecal specimens, and the association between selected socio-demographic variables and infection for 62 households. the overall prevalence of a. lumbricoides and t. trichiura was 45% (95% ci 39.0-51.9) and 38% (95% ci 31.8-44.4) respectively. the most intense infections for ascaris and trichuris were found in children aged 2-12 years old. by univariate analysis variables associated with infections of a. lumbricoides were: number of children 2-5 years old (p=0.001), level of formal education of respondents (p=0.01), reported site of defecation of children in households (p=0.02), households with children who had a recent history of diarrhea (p=0.002), and the location of households (p=0.03). variables associated with both a. lumbricoides and t. trichiura infection included: number of children 6-14 years old (p=0.01, p=0.04, respectively), ownership of a latrine (p=0.04, p=0.03, respectively) and coinfection with either helminth (p=0.001, p=0.001, respectively). by multivariate analysis the number of children 2-5 years living in the household, (p=0.01, odds ratio (or)=22.2), children with a recent history of diarrhea (p=0.0, or=39.8), and infection of household members with t. trichiura (p=0.02, or=16.0) were associated with a. lumbricoides infection. the number of children 6-14 years old in the household was associated with both a. lumbricoides and t. trichiura infection (p=0.04, p=0.01, or=19.2, or=5.2, respectively).
Prevalence and intensity of infections of Ascaris lumbricoides and Trichuris trichiura and associated socio-demographic variables in four rural Honduran communities  [cached]
Smith HM,DeKaminsky RG,Niwas S,Soto RJ
Memórias do Instituto Oswaldo Cruz , 2001,
Abstract: Between January and March 1998, a cross-sectional survey was carried out in four rural communities in Honduras, Central America. We examined the prevalence and intensity of Ascaris lumbricoides and Trichuris trichiura infections among 240 fecal specimens, and the association between selected socio-demographic variables and infection for 62 households. The overall prevalence of A. lumbricoides and T. trichiura was 45% (95% CI 39.0-51.9) and 38% (95% CI 31.8-44.4) respectively. The most intense infections for Ascaris and Trichuris were found in children aged 2-12 years old. By univariate analysis variables associated with infections of A. lumbricoides were: number of children 2-5 years old (p=0.001), level of formal education of respondents (p=0.01), reported site of defecation of children in households (p=0.02), households with children who had a recent history of diarrhea (p=0.002), and the location of households (p=0.03). Variables associated with both A. lumbricoides and T. trichiura infection included: number of children 6-14 years old (p=0.01, p=0.04, respectively), ownership of a latrine (p=0.04, p=0.03, respectively) and coinfection with either helminth (p=0.001, p=0.001, respectively). By multivariate analysis the number of children 2-5 years living in the household, (p=0.01, odds ratio (OR)=22.2), children with a recent history of diarrhea (p=0.0, OR=39.8), and infection of household members with T. trichiura (p=0.02, OR=16.0) were associated with A. lumbricoides infection. The number of children 6-14 years old in the household was associated with both A. lumbricoides and T. trichiura infection (p=0.04, p=0.01, OR=19.2, OR=5.2, respectively).
Density-dependent effects on the weight of female Ascaris lumbricoides infections of humans and its impact on patterns of egg production
Martin Walker, Andrew Hall, Roy M Anderson, María-Gloria Basá?ez
Parasites & Vectors , 2009, DOI: 10.1186/1756-3305-2-11
Abstract: We analyse data collected from a cohort of human hosts, and demonstrate that the per host mean weight (a proxy for size) of female Ascaris is dependent on the number of infecting females (worm burden) following a pattern of initial facilitation followed by limitation. Applying a negative binomial (NB) generalized linear model (GLM) and a zero-inflated negative binomial (ZINB) model we confirm that the per host female mean weight is significantly associated with per host egg production. Despite these associations, the mean weight of female Ascaris has little causal impact on patterns of density-dependent egg output. The ZINB model is able to account for the disproportionately large number of zero egg counts within the data and is shown to be a consistently better fit than the NB model. The probability of observing a zero egg count is demonstrated as being negatively associated with both female worm burden and female mean weight.The mean weight of female Ascaris is statistically significantly associated with egg output, and follows a consistent pattern of facilitation preceding limitation with increasing female worm burden. Despite these relationships, incorporation of female Ascaris mean weight into models of egg output has little effect on patterns of density dependence. The ZINB model is a superior fit to the data than the NB model and provides additional information regarding the mechanisms that result in a zero egg count. The ZINB model is shown to be a useful tool for the analysis of individual-based egg output data.Density-dependent population processes can occur at each stage of a parasite's lifecycle [1]. For the gastrointestinal (GI) nematodes these include establishment within the host, development and maturation time, adult survival, and female fecundity [2,3]. Density dependence has important implications for both the stability [2] and transmission dynamics [1,3,4] of helminth populations. Incorporation of these processes into mathematical models as accur
Are Ascaris lumbricoides and Ascaris suum a single species?
Daniela Leles, Scott L Gardner, Karl Reinhard, Alena I?iguez, Adauto Araujo
Parasites & Vectors , 2012, DOI: 10.1186/1756-3305-5-42
Abstract: Metazoan parasites of the order Ascaridida (Phylum Nemata: Class Secernentea) are classified into several families that occur in a wide range of hosts world-wide [1]. Mammals, from marsupials to human and non-human primates, birds, reptiles, and fishes, serve as common hosts [1-3]. Iguanodont coprolites dated from 100 million years ago were found positive for ascarid eggs [4]. Although found in many different hosts, species in this group are morphologically conservative, with little variation among groups [5].Ascaris lumbricoides Linnaeus 1758 is a parasite of Homo sapiens, and Ascaris suum Goeze 1782 occurs in pigs (Sus scrofa Linnaeus 1758). These two ascarids were probably recognized by humans since prehistory, due to their abundance, adult size, symptoms, and distribution. Eggs are commonly found in coprolites, intestinal contents of mummies, and in other kind of archaeological material [6]. Because of their remarkable similarity, several hypotheses have been proposed to explain their origin in their respective hosts. 1) The first hypothesis would be: Ascaris lumbricoides (usually infecting humans) and Ascaris suum (recorded mostly from pigs) are both valid species. In this case, these two species would have originated via a speciation event from a common ancestor, probably sometime before the domestication of pigs by humans. There are no records of Ascaris from the great apes, so this hypothesis has little support. 2) Ascaris lumbricoides in humans is derived directly from the species A. suum found in pigs with A. suum then existing as a persistent ancestor. In this case the species A. lumbricoides could have arisen by an allopatric event of host-switching (pig to human). 3) Ascaris suum is derived directly from A. lumbricoides with the persistent ancestor being A. lumbricoides and A. suum being the more newly derived species. Exactly the opposite of 2 above. Finally, hypothesis 4) states that: Ascaris lumbricoides and A. suum are conspecific, this hypothesis h
Host immune response to Toxoplasma gondii and Ascaris lumbricoides in a highly endemic area: evidence of parasite co-immunomodulation properties influencing the outcome of both infections
Bahia-Oliveira, Lílian MG;Silva, Juliana Azevedo da;Peixoto-Rangel, Alba Lucinia;Boechat, Marcela Santana Bastos;Oliveira, Annelise M Wilken Abreu;Massara, Cristiano L;Peixe, Ricardo Guerra;
Memórias do Instituto Oswaldo Cruz , 2009, DOI: 10.1590/S0074-02762009000200021
Abstract: toxoplasmosis and ascaridiasis evoke polar th-1 and th-2 host immune responses, respectively. a study to investigate the specific cytokine profile production by in vitro cultures of peripheral blood mononuclear cells from individuals living under precarious sanitary conditions in a highly endemic area for the parasites toxoplasma gondii and ascaris lumbricoides was conducted. high levels of both ifn-3 (th-1) and il-13 (th-2) were observed in groups of co-infected individuals presenting toxoplasmic ocular lesions. significantly lower il-10 and tgf-2 levels were produced by co-infected individuals in comparison with groups of individuals not infected with a. lumbricoides and either positive or negative for t. gondii living under good sanitary conditions (control groups). the possible influence of co-parasitism on the clinical presentation of ocular toxoplasmosis is discussed.
Liver abscess caused by Ascaris lumbricoides: case report
PINILLA, Análida Elizabeth;LóPEZ, Myriam Consuelo;RICAURTE, Orlando;CASTILLO, Blanca;MURCIA, Martha Isabel;NICHOLLS, Rubén Santiago;DUQUE, Sofía;OROZCO, Luis Carlos;
Revista do Instituto de Medicina Tropical de S?o Paulo , 2001, DOI: 10.1590/S0036-46652001000600010
Abstract: a case is reported of a woman who lived in a rural area with a chronic illness that consisted of weight loss and abdominal pain in the epigastrium and upper right quadrant. the initial diagnosis was a mass in the liver, which was later, demonstrated, both by direct and histological examination, to be an abscess caused by ascaris lumbricoides. eggs of ascaris lumbricoides and abundant charcot-leyden crystals were found.
Liver abscess caused by Ascaris lumbricoides: case report  [cached]
PINILLA Análida Elizabeth,LóPEZ Myriam Consuelo,RICAURTE Orlando,CASTILLO Blanca
Revista do Instituto de Medicina Tropical de S?o Paulo , 2001,
Abstract: A case is reported of a woman who lived in a rural area with a chronic illness that consisted of weight loss and abdominal pain in the epigastrium and upper right quadrant. The initial diagnosis was a mass in the liver, which was later, demonstrated, both by direct and histological examination, to be an abscess caused by Ascaris lumbricoides. Eggs of Ascaris lumbricoides and abundant Charcot-Leyden Crystals were found.
Diagnosis of Ascaris lumbricoides infection using capsule endoscopy  [cached]
Eduardo Tomohissa Yamashita,Wagner Takahashi,Daniel Yuiti Kuwashima,Tiago Ribeiro Langoni
World Journal of Gastrointestinal Endoscopy , 2013, DOI: 10.4253/wjge.v5.i4.189
Abstract: Ascaris lumbricoides (A. lumbricoides) is the most common intestinal roundworm parasite, infecting approximately one quarter of the world’s population. Infection can lead to various complications because it can spread along the gastrointestinal tract. Although A. lumbricoides infection is a serious healthcare issue in developing countries, it now also has a worldwide distribution as a result of increased immigration and travel. Intestinal obstruction is the most common complication of A. lumbricoides infection, potentially leading to even more serious consequences such as small bowel perforation and peritonitis. Diagnosis is based primarily on stool samples and the patient’s history. Early diagnosis, aided in part by knowledge of the local prevalence, can result in early treatment, thereby preventing surgical complications associated with intestinal obstruction. Further, delay in diagnosis may have fatal consequences. Capsule endoscopy can serve as a crucial, non-invasive diagnostic tool for A. lumbricoides infection, especially when other diagnostic methods have failed to detect the parasite. We report a case of A. lumbricoides infection that resulted in intestinal obstruction at the level of the ileum. Both stool sample examination and open surgery failed to indicate the presence of A. lumbricoides, and the cause of the obstruction was only revealed by capsule endoscopy. The patient was treated with anthelmintics.
Ascaris lumbricoides: Capacidad de unión a hialuronato Ascaris lumbricoides: Hyaluronan binding capacity
Patricia Ponce de León,Patricia Foresto,Juana Valverde
Acta bioqu?-mica cl?-nica latinoamericana , 2007,
Abstract: El ácido hialurónico tiene importantes funciones en los procesos inflamatorios y de reparación tisular. Sus principales receptores son CD44, RHAMM e ICAM-I. Debido a la variedad de estrategias utilizadas por los parásitos para evadir la respuesta inmune del hospedador y considerando las múltiples funciones e importancia fisiológica del ácido hialurónico, el objetivo de este trabajo fue determinar si Ascaris lumbricoides tiene capacidad de unión a hialuronato. Se trabajó con 36 extractos de A. lumbricoides obtenidos por remoción quirúrgica de la cutícula y ruptura mecánica refrigerada. Se modificó la técnica de detección de CD44 soluble en suero por Inhibición de la Agregación por adhesión. Los resultados demostraron que 23 de los 36 extractos estudiados tenían capacidad de unión a hialuronato. Este hecho podría deberse a la existencia de algún receptor en el parásito que une hialuronato y que eventualmente competiría con los receptores habituales del hospedador. A. lumbricoides podría utilizar este mecanismo para evadir la respuesta inmune. Hyaluronan acid has important functions in inflammatory and tissue reparation processes. Its main receptors are CD44, RHAMM and ICAM-I. Owing to the varied strategies of the parasites to evade the host′s immune response, and also considering the multiple functions and physiological importance of hyaluronan acid, the aim was to study if Ascaris lumbricoides has hyaluronan binding capacity. Extracts of A. lumbricoides were prepared by surgical remotion of the cuticle and refrigerated mechanical rupture. The study was done on 36 parasite extracts. The test of serum soluble CD44 Detection by Aggregation Inhibition was modified. Of the 36 extracts studied, 23 presented hyaluronan binding capacity. This fact can possibly be due to the existence of a receptor with hyaluronan acid binding capacity in the parasite, which eventually might compete with the usual receptors of the host. A. lumbricoides might use this mechanism to evade the immune response.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.