ABSTRACT
In a previous study, the Schistosoma mansoni Rho1 protein was able to complement Rho1 null mutant Saccharomyces cerevisiae cells at restrictive temperatures and under osmotic stress (low calcium concentration) better than the human homologue (RhoA). It is known that under osmotic stress, the S. cerevisiae Rho1 triggers two distinct pathways: activation of the membrane 1,3-beta-glucan synthase enzymatic complex and activation of the protein kinase C1 signal transduction pathway, promoting the transcription of response genes. In the present work the SmRho1 protein and its mutants smrho1E97P, smrho1L101T, and smrho1E97P, L101T were used to try to clarify the basis for the differential complementation of Rho1 knockout yeast strain by the human and S. mansoni genes. Experiments of functional complementation in the presence of caffeine and in the presence of the osmotic regulator sorbitol were conducted. SmRho1 and its mutants showed a differential complementation of the yeast cells in the presence of caffeine, since smrho1E97P and smrho1E97P, L101T mutants showed a delay in the growth when compared to the yeast complemented with the wild type SmRho1. However, in the presence of sorbitol and caffeine the wild type SmRho1 and mutants showed a similar complementation phenotype, as they allowed yeast growth in all caffeine concentrations tested.
Subject(s)
Animals , Humans , Caffeine/pharmacology , Protein Kinase C/genetics , Saccharomyces cerevisiae Proteins/genetics , Saccharomyces cerevisiae/genetics , Schistosoma mansoni/genetics , rho GTP-Binding Proteins/genetics , Genes, Helminth , Mutation , Saccharomyces cerevisiae Proteins/metabolism , Saccharomyces cerevisiae/drug effects , Saccharomyces cerevisiae/metabolism , Schistosoma mansoni/metabolism , Signal Transduction/genetics , rho GTP-Binding Proteins/metabolismABSTRACT
We have previously showed that Schistosoma mansoni ATP-diphosphohydrolase and Solanum tuberosum potato apyrase share epitopes and the vegetable protein has immunostimulatory properties. Here, it was verified the in situ cross-immunoreactivity between mice NTPDases and anti-potato apyrase antibodies produced in rabbits, using confocal microscopy. Liver samples were taken from Swiss Webster mouse 8 weeks after infection with S. mansoni cercariae, and anti-potato apyrase and TRITC-conjugated anti-rabbit IgG antibody were tested on cryostat sections. The results showed that S. mansoni egg ATP diphosphohydrolase isoforms, developed by anti-potato apyrase, are expressed in miracidial and egg structures, and not in granulomatous cells and hepatic structures (hepatocytes, bile ducts, and blood vessels). Therefore, purified potato apyrase when inoculated in rabbit generates polyclonal sera containing anti-apyrase antibodies that are capable of recognizing specifically S. mansoni ATP diphosphohydrolase epitopes, but not proteins from mammalian tissues, suggesting that autoantibodies are not induced during potato apyrase immunization. A phylogenetic tree obtained for the NTPDase family showed that potato apyrase had lower homology with mammalian NTPDases 1-4, 7, and 8. Further analysis of potato apyrase epitopes could implement their potential use in schistosomiasis experimental models.
Subject(s)
Animals , Male , Mice , Rabbits , Adenosine Triphosphatases/immunology , Apyrase/immunology , Schistosoma mansoni/enzymology , Schistosomiasis mansoni/immunology , Solanum tuberosum/enzymology , Amino Acid Sequence , Adenosine Triphosphatases/metabolism , Antibodies, Helminth/immunology , Apyrase/metabolism , Cross Reactions , Disease Models, Animal , Microscopy, Confocal , Molecular Sequence Data , Schistosoma mansoni/immunology , Schistosoma mansoni/metabolismABSTRACT
Foram investigados anticorpos de soro humano que provocam lise de eritrócitos de carneiro em ensaios hemolíticos. O presente estudo mostra que a presença de anticorpos citolíticos termoestáveis contra hemácias de carneiro é dependente da infecção por Schistosoma mansoni e é mais freqüente em adultos do que em crianças. A característica termo estável da hemolisina em soros normais não é dependente da presença de Ascaris lumbricoides, Trichuris trichiura ou ancilostomídeos. Além disto, anticorpos heterófilos hemolíticos termo estáveis ativadores de complemento foram demonstrados em crianças com associação de altas cargas de ovos de S. mansoni. Os resultados foram obtidos usando-se os testes z- e o qui quadrado. O teste z- nos permite formular uma alternativa "one side", isto é, a tendência de um dos atributos. Por outro lado o teste do qui quadrado analisa a independência entre atributos usando-se uma tabela de contingência. Ao lado dos interessantes resultados obtidos no campo da esquistossomose mansoni, a abordagem estatística pode apontar novos caminhos para o tratamento de dados na ciência médica.
Subject(s)
Adolescent , Adult , Animals , Child , Humans , Antibodies, Heterophile/immunology , Antibodies, Protozoan/immunology , Erythrocytes/immunology , Schistosoma mansoni/immunology , Schistosomiasis mansoni/immunology , Antibodies, Heterophile/blood , Feces/parasitology , Hemolysis , Hot Temperature , Helminths/immunology , Immunoassay/methods , Models, Statistical , Parasite Egg Count , Sheep , Schistosoma mansoni/metabolism , TemperatureABSTRACT
Calcium signalling is fundamental for muscular contractility of Schistosoma mansoni. We have previously described the presence of transport ATPases (Na+,K+-ATPase and (Ca2+-Mg2+)-ATPase) and calcium channels (ryanodine receptors - RyR) involved in control of calcium homeostasis in this worm. Here we briefly review the main technics (ATPase activity, binding with specific radioligands, fluxes of 45Ca2+ and whole worm contractions) and results obtained in order to compare the distribution patterns of these proteins: thapsigargin-sensitive (Ca2+-Mg2+)-ATPase activity and RyR co-purified in P1 and P4 fractions mainly, which is compatible with a sarcoplasmic reticulum localization, while basal ATPase (along with Na+,K+-ATPase) and thapsigargin-resistant (Ca2+-Mg2+)-ATPase have a distinct distribution, indicative of their plasma membrane localization. Finally we attempt to integrate these contributions with data from other groups in order to propose the first synoptic model for control of calcium homeostasis in S. mansoni
Subject(s)
Animals , Calcium/physiology , Homeostasis/physiology , Schistosoma mansoni/metabolism , Ca(2+) Mg(2+)-ATPase/metabolism , Calcium Signaling , Calcium/metabolism , Muscle, Smooth/metabolism , Ryanodine Receptor Calcium Release Channel/metabolism , Sodium-Potassium-Exchanging ATPase/metabolismABSTRACT
This study was performed to establish the changes in the level of some serum hormones [follicle stimulating hormone, FSH, leutinizing hormone, LH, and testosterone], as well as to determine the changes in the concentrations of some testicular lipid parameters [viz., total cholesterol and total triacylglycerols] of infected mice with Schistosoma mansoni for different periods of time. Electron microscopical studies were also performed to define any histological changes in the testis upon infection with S. Mansoni. The serum levels of gonadotropins [FSH, LH] showed no significant changes in infected as compared with control mice. On the other hand, the serum level of testosterone showed a significant decrease [P <0.001] in infected as compared with control mice starting from the 14th week post infection. Testicular lipids showed a significant increase [P <0.01] in the concentration of total cholesterol and a significant decrease [P <0.005] in the concentration of total triacylglycerols in infected as compared with control mice, especially at late stages of infection [14 - 20 weeks post infection]. However, electron microscopical studies showed nonsignificant histological changes in the testicular tissues of infected mice at different stages of infection
Subject(s)
Animals, Laboratory , Schistosoma mansoni/metabolism , Testis/metabolism , Mice , Lipids/blood , Follicle Stimulating Hormone/blood , Luteinizing Hormone/blood , Schistosomiasis mansoni/pathologyABSTRACT
Dois antissoros produzidos em carneiros, um dos quais contra a fracao polissacaridica (Po) e outro contra componentes proteicos (Pt) de vermes adultos de Schistosoma mansoni, foram avaliados quanto ao seu desempenho na deteccao de antigenos parasitarios circulantes em pacientes com diferentes formas ciclicas da esquistossomose mansonica, atraves de um ensaio imunoenzimatico, (ELISA). O primeiro antissoro revelava antigenos parasitarios no granuloma hepatico e o segundo, nos glomerulos renais de pacientes com esquistossomose mansonica, bem como em camundongos experimentalmente infectados pelo S. mansoni....
Subject(s)
Humans , Polysaccharides/immunology , Schistosoma mansoni/drug effects , Schistosomiasis mansoni/immunology , Enzyme-Linked Immunosorbent Assay , Oxamniquine/therapeutic use , Polysaccharides/isolation & purification , Praziquantel/therapeutic use , Schistosoma mansoni/metabolism , Schistosomiasis mansoni/drug therapyABSTRACT
O tratamento com dexametasona (DMS) nas fases iniciais da infeccao experimental com S. mansoni leva a um efeito indireto sobre o processo de transformacao da cercaria em esquistossomulo, quando camundongos isentos de infeccao sao tratados com esta droga (50 mg/kg, subcutaneamente) e, 01 hora depois, sao infectados intraperitonealmente com cerca de 500 cercarias de S. mansoni (cepa LE). Foi observada uma significativa reducao na adesao de celulas do hospedeiro as larvas, com um atraso simultaneo no processo de transformacao das cercarias em esquistossomulos...
Subject(s)
Animals , Mice , Dexamethasone/pharmacology , Schistosoma mansoni/drug effects , Schistosoma mansoni/metabolismABSTRACT
Indicadores do estado nutricional de proteínas foram estudados em camundongos albinos suíços recém-desmamados e infectados com S. mansoni, aos quais foi administrada a Dieta Básica Regional (DBR) do Nordeste do Brasil. Cada camundongo foi infectado com 80 cercárias, por via percutânea. O experimento teve a duraçäo de 63 dias. Os parâmetros investigados foram: evoluçäo ponderal, consumo alimentar, ingestäo protéica, ganho ponderal, Coeficiente de Eficiência Protéica (PER) e Coeficiente de Eficiencia Proetéica Líquida (NPR). Os camundongos alimentados com a DBR revelaram acentuada perda de peso, menor consumo alimentar e protéico, maior lentidäo no ganho em peso relacionado com a fase de crescimento e taxas menos elevadas de utilizaçäo da proteína dietética, quando comparados com os controles (alimentados com dieta balanceada, à base de 22,60 por cento de caseína). As diferenças encontradas entre camundongos infectados e näo infectados, näo foram consistentes. Os resultados sugerem que os efeitos provocados pela má-nutriçäo induzida pelo consumo da DBR säo muito mais perniciosos para a saúde e estado nutricional do hospedeiro, do que aqueles resultantes da infecçäo pelo S. mansoni, na fase inicial da doença
Subject(s)
Mice , Animals , Male , Female , Animal Nutritional Physiological Phenomena , Diet , Schistosoma mansoni/metabolism , Brazil , Protein-Energy Malnutrition/metabolism , Disease Models, Animal , Dietary Proteins/administration & dosage , Weaning , Weight GainABSTRACT
La impregnación con nitrato de plata de cercarias de Schistosoma mansoni obtenidas de Biomphalaria tenogophila naturalmente infectadas y provenientes de la localidad de Taubaté (Brasil), nos permitió evidenciar que: El criterio "12 papilas corporales tanto en la superficie ventral como en la superficie dorsal", clásicamente descrito por los autores, no es constante, ya que en las cercarias por nosostros estudiadas, dicho número de papilas se observó sólo en un 26% de las visitas ventrales y en un 67% de las vistas dorsales. Aunque los autores coinciden en la no existencia de papilas en posición A11V, nosotros encontramos en 43% de cercarias con papilas en posición para un hemicuerpo y un 37% para el otro hemicuerpo. Esta papila A11 V podía estar presente en uno o ambos hemicuerpos. El "Indice cercariano" calculado fue en promedio 1,15 + ou - 0,10
Subject(s)
Biomphalaria/parasitology , Schistosoma mansoni/metabolism , Silver Nitrate/metabolismABSTRACT
Se hizo una revisión crítica de los diferentes métodos de obtención de la fracción membranosa del tegumento, de la doble membrana o de sus bicapas lipídicas, incluyendo información sobre la localización de la fosfatasa alcalina, fosfodiesterasa y Ca-ATPasa en estas últimas. Las moléculas enzimáticas parecen atravesar las dos bicapas en parte o en todo su espesor exponiendo un sitio antigénico en la superficie del verme y el sitio de actividad enzimática en posición más interna. Los datos experimentales llevan a considerar que a excepción de algunas regiones de la superficie parasitaria, las dos bicapas están muy unidas entre sí y no son naturalmente separables. Se discute la importancia de las propiedades asimétricas de la doble membrana de superficie en la relación hospedador-parásito