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Search Results: 1 - 10 of 238855 matches for " Richard C. Pacheco "
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Dynamic of the natural infection by Anaplasma marginale in Holstein cows and calves in the Londrina region, North of Paraná State, Brazil/ Dinamica da infec o natural pelo Anaplasma marginale em vacas e bezerros da ra a Holandesa, na regi o de Londrina, Estado do Paraná, Brasil
Richard C. Pacheco,Odilon Vidotto,Kátia Tamekuni,Michelle Igarashi
Semina : Ciências Agrárias , 2004,
Abstract: The dynamic of the infection by Anaplasma marginale in Holstein cows and calves was studied in two dairy farms (A and B) in the Londrina region, North of Paraná. In the farm A the cows were maintained in the tie-stall system and, the calves in collective stall; in the farm B, the cows stayed in freestall system and the calves in individual cages. Every 15 days, blood samples were collected from the dams 45 days before parturition until 60 days post partum, and from their calves at birth until 240 days of age. Tick burden counting was also performed on dams and calves twice a month. Percentage of infected erythrocytes was established by Giemsa-stained smears. Blood and sera samples were examined by Polimerase Chain Reaction (PCR) and competitive Enzime-Linked Immunosorbent Assay (cELISA), respectively. In the cows, the anti-A. marginale antibody levels decreased close to the parturition, showing an adverse behavior among the farms. In the farm A the levels of antibodies increased between 30 and 60 days after the parturition and, in farm B the antibodies stayed in low levels during the accompaniment period of the cows. The anti-A. marginale antibody levels of the calves of the farm A, that were not high in the day of the birth, decreased more until 45 days post parturition and it increased again starting from 60 days, with maximum pick to the 105 days. In the farm B, where the calves presented higher levels of antibodies at the birth day, there was a slower decrease of the antibody levels, reaching the lowest point to the 75 days post parturition and it increased again more tardily, to the 165 days of age. The dams and calves in both farms were exposure to cattle tick Boophilus microplus during almost all period of accompaniment and they showed rickettsemia ranging from 0 to 1%. In conclusion, A. marginale infection after birth was more influenced by maternal antibody levels than tick burden; the differences between animals handling influenced the antibody levels of the dams and calves, and during the natural infection period of the calves; tick burden did not influence the rickettsemia in the studied farms. A dinamica da infec o por Anaplasma marginale em vacas e bezerros da ra a Holandesa foi estudada em duas propriedades leiteiras (A e B) com manejos distintos da regi o Norte do Paraná. Na propriedade A as vacas eram mantidas no sistema “tie-stall” e, os bezerros em bezerreiros coletivos; na propriedade B, as vacas em sistema “free-stall” e os bezerros em gaiolas individuais. A cada 15 dias efetuou-se a contagem de carrapatos e coletas de amostras de s
Infección por rickettsia en capibaras (Hydrochoerus hydrochaeris) de S o Paulo, Brasil: evidencia serológica de infección por Rickettsia bellii y Rickettsia parkeri Rickettsial infection in capybaras (Hydrochoerus hydrochaeris from S o Paulo, Brazil: serological evidence for infection by Rickettsia bellii and Rickettsia parkeri
Richard C. Pacheco,Mauricio C. Horta,Jonas Moraes-Filho,Alexandre C. Ataliba
Biomédica , 2007,
Abstract: Introducción. En Brasil, los capibaras (Hydrochoerus hydrochaeris) son importantes huéspedes para garrapatas del género Amblyomma, las cuales transmiten rickettsiosis a humanos y animales. Por lo tanto, estos roedores pueden ser potenciales centinelas para detectar infección por rickettsia. Objetivos. Este trabajo evaluó la infección por rickettsia en capibaras de diferentes regiones del estado de S o Paulo, donde las rickettsiosis nunca han sido reportadas. Materiales y métodos. Se examinarion los sueros de 73 capibaras de seis localidades en S o Paulo con la prueba de immunofluorescencia indirecta con antígenos de Rickettsia rickettsii, Rickettsia parkeri y Rickettsia bellii. Los bazos de los capibaras se extrajeron y se analizaron por reacción en cadena de la polimerasa para un fragmento del gene gltA de rickettsia. Las garrapatas se recolectaron de los capibaras y se identificaron hasta especie. Resultados. Diecinueve (26,0%), 25 (34,2%) y 50 (68,5%) sueros de los capibaras reaccionaron con R. rickettsii, R. parkeri y R. bellii, respectivamente. De los 50 sueros que reaccionaron con antígenos de R. bellii, 25 presentaron títulos, por lo menos, cuatro veces mayores que los otros dos antígenos. Estos sueros fueron considerados homólogos de R. bellii. Usando el mismo criterio, tres sueros de los capibaras se consideraron homólogos de R. parkeri. Ningún suero se consideró homólogo de R. rickettsii. No se detectó ADN de rickettsia en bazo. Las garrapatas recolectadas de los capibaras fueron identificadas como Amblyomma dubitatum y Amblyomma cajennense. Conclusiones. Este trabajo reporta la primera evidencia de infección natural por R. bellii en vertebrados y, también, la primera evidencia de infección por R. parkeri en capibaras. Se sabe que R. parkeri infecta y produce enfermedad en humanos; sin embargo, no hay evidencia de infección humana por R. bellii. Introduction. In Brazil, capybaras (Hydrochoerus hydrochaeris) are important hosts for Amblyomma ticks, which in turn can transmit rickettsiae to humans and animals. Therefore, capybaras are potential sentinels for rickettsial infection. Objective. The present study evaluated rickettsial infection in capybaras in different areas of the state of S o Paulo, where rickettsiosis has never been reported. Materials and methods. Blood sera from 73 capybaras from six localities in S o Paulo were tested by indirect immunofluorescence assay using Rickettsia rickettsii, Rickettsia parkeri, and Rickettsia bellii antigens. Capybara spleens were tested by PCR, targeting a fragment of the rickettsial gltA gene. Ticks
Caracterización del maíz "Llute?o" (Zea mays L. tipo amylacea) proveniente del norte de Chile, tolerante a NaCl y exceso de boro, como una alternativa para la producción de bioenergía
Bastías,Elizabeth; Díaz M.,Mayerling; Pacheco C.,Patricia; Bustos P,Richard; Hurtado C,Elvis;
Idesia (Arica) , 2011, DOI: 10.4067/S0718-34292011000300002
Abstract: the aim of this study was to examine the chemistry and biochemistry of plant tissues and evaluate the growth parameters of maíze variety llute?o (zea mays l. amylacea type), to consider the alternative production of bioethanol from biomass waste obtained from the chaff of corn after harvest, in the valley of lluta (arica-chile). the entire production of corn is geared mainly for fresh consumption, the dry biomass or chaff currently has no productive use. this material is burned and rarely incorporated into the soil and few farmers use it as fodder, wasting large volumes of biomass in the valley. this study estimated the content of ethanol from biomass and characterized the behavior of plants under field conditions from may to october 2008. the parameters examined during the crop phenology were biomass, relative water content (rwc), chlorophyll content and total soluble sugars the results suggest that llute?o corn has an exponential growth of biomass content and plant height, despite the high salinity and excess b in the soil and irrigation water; this increase in biomass was significant in the month of october, about 94%. the content of chlorophyll in the leaves was maintained, showing not be a limiting factor in the assimilation of co2. total soluble sugars, also increased up to 86%, suggesting that llute?o corn would use the significant increase of the organic solute to increase indirectly the potential bioethanol content; this solute may also act as an osmoregulator and/or osmoprotectant to maintain the water status of plants, thereby enabling a high production of biomass. the estimated levels of ethanol after harvest may be considered very good, noting that the sample was only from dry biomass and husks were not included; this being an important advantage that does not affect human consumption of this corn.
Serosurvey of Rickettsia spp. in dogs and humans from an endemic area for Brazilian spotted fever in the State of S?o Paulo, Brazil
Pinter, Adriano;Horta, Maurício C.;Pacheco, Richard C.;Moraes-Filho, Jonas;Labruna, Marcelo B.;
Cadernos de Saúde Pública , 2008, DOI: 10.1590/S0102-311X2008000200003
Abstract: the present study provides a rickettsial serosurvey in 25 dogs and 35 humans in an endemic area for brazilian spotted fever in the state of s?o paulo, where the tick amblyomma aureolatum is the main vector. testing canine and human sera by indirect immunofluorescence against four rickettsia antigens (r. rickettsii, r. parkeri, r. felis and r. bellii) showed that 16 (64%) of canine sera and 1 (2.8%) of human sera reacted to at least one of these rickettsial antigens with titers 3 64. seven canine sera and the single reactive human serum showed titers to r. rickettsii at least four times those of any of the other three antigens. the antibody titers in these 7 animals and 1 human were attributed to stimulation by r. rickettsii infection. no positive canine or human serum was attributed to stimulation by r. parkeri, r. felis, or r. bellii. our serological results showed that dogs are important sentinels for the presence of r. rickettsii in areas where the tick a. aureolatum is the main vector of brazilian spotted fever.
Serological evidence of Rickettsia parkeri as the etiological agent of rickettsiosis in Uruguay
Conti-Díaz, Ismael A.;Moraes-Filho, Jonas;Pacheco, Richard C.;Labruna, Marcelo B.;
Revista do Instituto de Medicina Tropical de S?o Paulo , 2009, DOI: 10.1590/S0036-46652009000600005
Abstract: we report three new rickettsiosis human cases in uruguay. the three clinical cases presented clinical manifestations similar to previous reported cases of rickettsia parkeri in the united states; that is mild fever (< 40 oc), malaise, headache, rash, inoculation eschar at the tick bite site, regional lymphadenopathy, and no lethality. serological antibody-absorption tests with purified antigens of r. parkeri and rickettsia rickettsii, associated with immunofluorescence assay indicated that the patients in two cases were infected by r. parkeri. epidemiological and clinical evidences, coupled with our serological analysis, suggest that r. parkeri is the etiological agent of human cases of spotted fever in uruguay, a disease that has been recognized in that country as cutaneous-ganglionar rickettsiosis.
Albúmina en el paciente crítico: Mito o realidad terapéutica? Albumin in the critically ill patient: myth or real therapeutics?
SUZANNA PACHECO V,ADRIANA WEGNER A,RICHARD GUEVARA Q,PAMELA CéSPEDES F
Revista chilena de pediatría , 2007,
Abstract: La albúmina es la principal determinante de la presión oncótica plasmática. La reducción de sus niveles séricos se asociaría a malos resultados clínicos, fundamentalmente, en la población de pacientes críticos, por lo cual su administración exógena resulta una estrategia terapéutica atractiva y ampliamente difundida. Su uso, sin embargo, ha sido cuestionado en el último tiempo, no existiendo a la fecha una clara evidencia de su real eficacia y/o utilidad. Objetivo: Revisar los conceptos fisiológicos y fisiopatológicos que subyacen al uso de albúmina sintética y evaluar la racionalidad de su utilización en distintas situaciones patológicas, intentando perfilar las condiciones clínicas que pudieran o no beneficiarse de su administración. La hipoalbuminemia en el paciente crítico está dada principalmente por un fenómeno de redistribución, secundario a cambios en la permeabilidad capilar (escape transcapilar), y la correlación entre presión osmótica plasmática y concentración de albúmina en individuos sanos, se pierde en condiciones críticas. A pesar de la literatura existente, no se han logrado acuerdos sobre las indicaciones para el uso de albúmina, ya que en los distintos contextos clínicos revisados, (resucitación, sepsis, post quirúrgicos, quemados, síndrome nefrótico, SDRA), no aparecen ventajas significativas en la morbimortalidad al compararla con el uso de cristaloides u otros coloides sintéticos, sin dejar de mencionar además el costo económico que representa su uso. Se requieren guías clínicas de consenso, basadas en la evidencia, que establezcan recomendaciones acerca de los beneficios e indicaciones de esta herramienta terapéutica, que por ahora aparece con indicaciones muy limitadas en los pacientes críticos Under normal conditions, the plasmatic oncotic pressure is determined mainly by albumin. Numerous trials in critically ill patients have showed that hypoalbuminemia is associated to poor outcome. So, the administration of exogenous albumin is an attractive therapeutic strategy, widely spread in different clinical scenes. Nevertheless, its use has been questioned in the last period and up to date there is no clear evidence of the real effectiveness and/or utility. This article reviews the physiological and pathophysiological concepts that would justify the use of synthetic albumin. According to current literature, discussion about the rationality of its use in different pathological situations exists, trying to outline those clinical conditions that could or could not benefit with its administration. Certainly, clinical guidelines with reco
Enfermedad injerto contra huésped asociada a transfusión Graft versus Hot Disease associated to Transfusion
ADRIANA WEGNER A,SUZANNA PACHECO V,PAMELA CéSPEDES F,RICHARD GUEVARA Q
Revista chilena de pediatría , 2007,
Abstract: Introducción: La Enfermedad Injerto Contra Huésped asociada a Transfusiones (EICH-AT) se produce por una respuesta inadecuada y autodestructiva del organismo frente a la incorporación y proliferación de linfocitos T presentes en los hemoderivados. Afecta fundamentalmente a pacientes inmunosuprimidos de predominio celular, aunque también a inmunocompetentes con determinadas características genéticas. Se manifiesta como un síndrome agudo que compromete piel, hígado, tracto gastrointestinal y médula ósea, confundible al inicio con enfermedades banales frecuentes. Actualmente la prevención, mediante el uso de hemoderivados irradiados representa la única medida terapéutica demostrada. Objetivo: Presentar una entidad patológica grave y poco reconocida asociada a una práctica clínica habitual. Caso clínico: Lactante de 6!4 meses portadora de una Inmunodeficiencia Combinada Severa que posterior a una transfusión de glóbulos rojos filtrados desarrolló esta enfermedad. Conclusiones: La EICH-AT es una complicación iatrogénica infrecuente, altamente letal y potencialmente prevenible relacionada a la administración de hemoderivados. Requiere un alto grado de sospecha clínica, mas aun en menores de 1 a o en quienes pueden desconocerse patologías de riesgo subyacentes Background: Transfusion-associated graft versus host disease (AT-GVDH) is produced by an aggressive host inmune response secondary to the incorporation and proliferation of T lymphocytes in blood products. AT-GVDH affects immunocompromised patients with cellular immune dysfunction, but also immunocompetent persons with certain genetic characteristics. It presents as an acute syndrome that involves skin, gastrointestinal tract, liver and bone marrow. The use of irradiated blood products represents the only therapeutic choice. Objective: To describe a severe and rarely diagnosed pathological condition associated to frequent clinical practice. Case-report: A 6 months-old child with a severe combined immunodeficiency (pathology with high risk of AT-GVDH) who developed this disease after a filtered red blood cell transfusion. Conclusions: The AT-GVDH is an uncommon iatrogenic and highly lethal complication related to the use of blood products. It implies high degree of clinical suspicion because underlying pathologies of risk may be unknown. The therapy is poor, being prevention the only available alternative. It is fundamental to know the risks and complications in using blood products, in order to determine correctly their indications
Caracterización del maíz "Llute o" (Zea mays L. tipo amylacea) proveniente del norte de Chile, tolerante a NaCl y exceso de boro, como una alternativa para la producción de bioenergía Characterization of maíze "Llute o" (Zea mays L. amylaceae type) from northern Chile, tolerant to NaCl and excess of boron, as an alternativefor bio-energy production
Elizabeth Bastías,Mayerling Díaz M.,Patricia Pacheco C.,Richard Bustos P
IDESIA , 2011,
Abstract: El objetivo del presente trabajo consistió en estudiar la composición química y bioquímica de los tejidos vegetales y evaluar los parámetros de crecimiento del maíz "Llute o" (Zea mays L. tipo amylacea), para considerar otra alternativa productiva de este cultivo, la producción de bioetanol, a partir de la biomasa de desecho obtenido de la "chala" de maíz, después de la cosecha en el valle de Lluta (Arica-Chile). La totalidad de la producción de este maíz se orienta, principalmente, al consumo fresco; la biomasa aérea seca o "chala", actualmente, no tiene un uso productivo, por el contrario, este material es quemado y muy pocas veces incorporado al suelo y pocos agricultores lo ocupan como forraje, desaprovechando, así, grandes volúmenes de biomasa. En el presente estudio se estimó el contenido de etanol a partir de esta biomasa y se caracterizó el comportamiento de las plantas en condiciones de campo, desde mayo a octubre del 2008. Los parámetros analizados durante la fenología del cultivo fueron el contenido de biomasa, el contenido relativo de agua (CRA), cuantificación del contenido de clorofilas y azúcares solubles totales. Los resultados sugieren que el maíz "Llute o" tiene un crecimiento exponencial del contenido de biomasa y de la altura, a pesar de la alta salinidad y exceso de B, presente en el suelo y agua de riego; este incremento de la biomasa fue significativo en el mes de octubre, alrededor de un 94%. El contenido de clorofilas en las hojas se mantuvo, mostrando así no ser una limitante en la asimilación del CO2. En este sentido, el contenido de azúcares solubles totales también se incrementó hasta un 86%, sugiriendo que el maíz "Llute o" utilizaría el aumento significativo de este soluto orgánico para incrementar el contenido de bioetanol; además, este soluto también podría actuar de osmorregulador y/o osmoprotector para mantener el estado hídrico de las plantas, permitiendo, así, una alta producción de la biomasa. En cuanto a los niveles de etanol estimados después de cosecha se pueden considerar muy buenos destacando que la muestra analizada fue sólo a partir de biomasa seca y no se incluyó la mazorca, siendo una ventaja importante que no afecta el consumo humano de este maíz. The aim of this study was to examine the chemistry and biochemistry of plant tissues and evaluate the growth parameters of maíze variety Llute o (Zea mays L. amylacea type), to consider the alternative production of bioethanol from biomass waste obtained from the chaff of corn after harvest, in the valley of Lluta (Arica-Chile). The entire production of corn is ge
Rickettsial infection in capybaras (Hydrochoerus hydrochaeris) from S?o Paulo, Brazil: serological evidence for infection by Rickettsia bellii and Rickettsia parkeri
Pacheco,Richard C; Horta,Mauricio C; Moraes-Filho,Jonas; Ataliba,Alexandre C; Pinter,Adriano; Labruna,Marcelo B;
Biomédica , 2007,
Abstract: introduction. in brazil, capybaras (hydrochoerus hydrochaeris) are important hosts for amblyomma ticks, which in turn can transmit rickettsiae to humans and animals. therefore, capybaras are potential sentinels for rickettsial infection. objective. the present study evaluated rickettsial infection in capybaras in different areas of the state of s?o paulo, where rickettsiosis has never been reported. materials and methods. blood sera from 73 capybaras from six localities in s?o paulo were tested by indirect immunofluorescence assay using rickettsia rickettsii, rickettsia parkeri, and rickettsia bellii antigens. capybara spleens were tested by pcr, targeting a fragment of the rickettsial glta gene. ticks were collected from each capybara sample and taxonomically identified to species. results. a total of 94 positively reacting capybara samples, 19 (26.0%), 25 (34.2%), and 50 (68.5%) capybara sera reacted to r. rickettsii, r. parkeri, and r. bellii, respectively. twenty-five capybara sera showed titers to r. bellii at least four-fold higher than to any of the other two antigens. these sera were considered homologous to r. bellii. using the same criteria, 3 capybara sera were considered homologous to r. parkeri. no sera were be considered homologous to r. rickettsii. no rickettsial dna was detected in capybara spleen samples. ticks collected on capybaras were amblyomma dubitatum and amblyomma cajennense. conclusions. the first evidence is reported of r. bellii natural infection in vertebrate hosts, and the first evidence of r. parkeri infection in capybaras. while r. parkeri is known to infect and cause disease in humans, no similar evidence for human infection has been indicated by r. bellii.
Detection of Rickettsia rickettsii in the tick Amblyomma cajennense in a new Brazilian spotted fever-endemic area in the state of Minas Gerais
Guedes, Elizangela;Leite, Romário C;Prata, Márcia CA;Pacheco, Richard C;Walker, David H;Labruna, Marcelo B;
Memórias do Instituto Oswaldo Cruz , 2005, DOI: 10.1590/S0074-02762005000800004
Abstract: the present study evaluated rickettsial infection in amblyomma spp. ticks collected in a farm in coronel pacheco, a brazilian spotted fever (bsf) endemic area. a total of 78 a. cajennense and 78 a. dubitatum free-living adult ticks were collected and tested by polymerase chain reaction (pcr) targeting a fragment of the rickettsial gene glta. only one pool of three a. cajennense ticks showed the expected product by pcr. this pool was further tested by pcr using sets of primers targeting the rickettsial genes glta, ompa, and ompb. all reactions yielded the expected bands that by sequencing, showed 100% identity to the corresponding sequences of the rickettsia rickettsii gene fragments glta (1063-bp), ompa (457-bp), and ompb (720-bp). the minimal infection rate of r. rickettii in the a. cajennense population was 1.28% (at least one infected tick within 78 ticks).the present study showed molecular evidence for the presence of r. rickettsii in a. cajennense from a bsf-endemic area in coronel pacheco, state of minas gerais. although r. rickettsii has been previously reported infecting a. cajennense ticks in brazil and other latin american countries, the present study performed the first molecular characterization of r. rickettsii from the tick a. cajennense.
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