733 resultados para TesteAllium cepa


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Las Clamidias son bacterias patógenas de los animales de producción, de vida silvestre y de compañía. Además de las pérdidas económicas que producen las infecciones en los planteles de producción bovina, ovina, caprina, porcina y aves de corral, la mayoría de las especies tienen importancia zoonótica, pudiendo dar origen a infecciones graves, potencialmente letales en el ser humano. El orden Chlamydiales está integrado por bacterias que actúan como parásitos intracelulares obligados que desarrollan su ciclo de vida únicamente dentro de inclusiones citoplasmáticas. En este orden se encuentra la familia Chlamydiaceae que comprende dos géneros, Chlamydia y Chlamydophila; y las especies, Chlamydia trachomatis, C. suis, C. muridarum, Chlamydophila psittaci, C. abortus, C. felis, C. caviae, C. pecorum, y C. pneumoniae. C. psittaci causa psitacosis o clamidiosis aviar. En Argentina, los primeros casos clínicos de psitacosis fueron reportados en 1929. Los criadores de aves y quienes las poseen como mascotas, representan el grupo de mayor riesgo; pero también las personas que trabajan en pajarerías y aquellas que por su empleo se ven expuestas a contraer la enfermedad (empleados en peladeros donde se carnean y procesan pollos y otras aves para consumo, veterinarios, empleados de zoológicos, etc.). La infección en humanos se presenta como una neumonía severa; con fiebre alta, escalofríos, dolor de cabeza, mialgia y dificultad respiratoria. Ocasionalmente puede presentarse vómitos, dolor abdominal, diarrea y complicaciones como miocarditis, endocarditis, encefalitis, ictericia y fallas multiorgánicas, que pueden ser fatales sino se le administra el tratamiento adecuado. La infección en las mujeres embarazadas puede producir neumonía, hepatitis, insuficiencia renal, sepsis, parto prematuro y muerte fetal. Existen más de 465 especies de aves en las que se registró C. psittaci, incluyendo ornamentales, de corral, silvestres, acuáticas y palomas. Las patologías que pueden producir en estos animales son neumonitis, conjuntivitis, encefalomielitis, placentopatías, fetopatías, anorexia, diarrea e infecciones persistentes asintomáticas u oligosintomáticas. En bovinos, C. pecorum, C. abortus y C. psittaci producen infecciones respiratorias y genitales; que se presentan como cuadros de enteritis, artritis, encefalomielitis, endometritis e hipofertilidad. En Argentina, la infección clamidial en el ganado caprino fue asociada a daños en el tejido uterino, abortos, partos prematuros y crías débiles. En equinos, C. psittaci y C. pneumoniae producen abortos y desórdenes respiratorios, con un gran impacto en ganadería que redunda en pérdidas económicas. Considerando que existen escasos estudios eco-epidemiológicos y clínicos que reporten el estado de situación de estas infecciones en nuestro medio, es que el presente trabajo propone actualizar y profundizar el conocimiento de las especies de Clamidias de importancia médico-veterinaria presentes en la provincia de Córdoba, Argentina. El desarrollo de este proyecto aportará la implementación de técnicas que mejorarán el diagnóstico microbiológico, confirmarán los cuadros clínicos; y por lo tanto contribuirá al conocimiento de estos agentes infecciosos en nuestra región. Esta información es indispensable para los organismos responsables de la Salud Pública (Ministerios de Salud y Educación, Municipios, etc.) para que puedan obrar en consecuencia y generar sistemas de alerta temprana, tomar medidas de prevención y medidas de control frente a la presencia de un brote epidémico por alguna cepa clamidial.

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El Trypanosoma cruzi, agente causal del Chagas, atraviesa la placenta, pudiendo infectar el feto y causando la enfermedad de Chagas congénita. Hay evidencias de que la competencia inmunológica de la placenta juega un rol en la transmisión congénita. El proceso de infección placentario puede verse modificado por el juego entre factores deletéreos para T. cruzi, como el óxido nítrico (NO), estrés nitrosativo-oxidativo (EO) y la cantidad de parásitos y capacidad de la célula parasitaria de resistir, invadir y proliferar dentro del tejido placentario. El factor inhibitorio de la migración de macrófagos (MIF) es una citoquina proinflamatoria que juega un importante rol inmuno-regulatorio que estimula la producción de NO. Por ello postulamos como hipótesis que T. cruzi incrementa la producción de MIF en placenta, con aumento de citoquinas proinflamatorias, óxido nítrico e incremento del estrés nitrosativo, participando en la infección de la placenta y el mecanismo de transmisión congénita de la enfermedad. Los objetivos específicos son: a)Analizar el sistema MIF - ICAM1 - NO en la infección de explantos de vellosidades placentarias por formas trypomastigotes del T. cruzi en diseños experimentales in vitro. b)Verificar estado de estrés oxidativo-nitrosativo y alteraciones de la barrera placentaria inducido por óxido nítrico en explantos placentarios en presencia de T. cruzi in vitro. c)Analizar la expresión de MIF e ICAM-1 en placentas en un modelo de Chagas congénito en ratones infectados con T. cruzi de la cepa Tulahuen con dieta normoproteica y normocalorica. d)Verificar nivel de transmisión congénita en las crías de ratones infectados por T. cruzi según expresión de MIF e ICAM1 con dietas normales para estos animales. Los diseños experimentales serán in Vitro mediante empleo de explantos de placentas en cultivo en interacción con formas infectivas de T. cruzi y diseños en ratones en un modelo de transmisión congénita. Las técnicas a emplear serán cultivos de tejidos, técnicas inmunohistoquímicas, western blot, PCR y qPCR, RT-qPCR, mediciones analíticas en medios de cultivos y plasma y suero de ratones. Esperamos encontrar una respuesta inflamatoria exacerbada, como ya ha sido descripta en embarazadas que produjeron transmisión congénita de la enfermedad de Chagas a sus hijos, el incremento de citoquinas pro-inflamatorias y del estrés nitrosativo como el observado in vitro inducido por T. cruzi, (resultados preliminares) que podrían dañar la barrera placentaria y favorecer la transmisión congénita de la enfermedad de Chagas mediada por MIF. Como MIF se puede detectar en circulación sanguínea de la embarazada que en parte es aportado por la placenta (Cardalopolis y col., 2012), podría emplearse como un indicador de la probabilidad de transmisión congénita de la enfermedad.

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O conflito existente entre o direito do autor, direitos culturais e acesso à informação assolam inúmeros debates jurídicos no país. Todos esses são direitos com amparo constitucional que encontram na realidade social obstáculos para serem conciliados. O advento da internet permitiu que obras artísticas fossem distribuídas democraticamente ao redor do mundo, rompendo com a maneira tradicional de distribuir cultura e informação, antes proporcionadas, principalmente, pelo meio tradicional da compra. Faz-se necessário repensar esses institutos e como conciliá¬-los para beneficiar a coletividade.

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Biography of author on verso of half-title.

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Edaphic factors affect the quality of onions (Allium cepa). Two experiments were carried out in the field and glasshouse to investigate the effects of N (field: 0, 120 kg ha(-1); glasshouse: 0, 108 kg ha(-1)), S (field: 0, 20 kg ha(-1); glasshouse: 0, 4.35 kg ha(-1)) and soil type (clay, sandy loam) on onion quality. A conducting polymer sensor electronic nose (E-nose) was used to classify onion headspace volatiles. Relative changes in the E-nose sensor resistance ratio (%dR/R) were reduced following N and S fertilisation. A 2D Principal Component Analysis (PCA) of the E-nose data sets accounted for c. 100% of the variations in onion headspace volatiles in both experiments. For the field experiment, E-nose data set clusters for headspace volatiles for no N-added onions overlapped (D-2 = 1.0) irrespective of S treatment. Headspace volatiles of N-fertilised onions for the glasshouse sandy loam also overlapped (D-2 = 1.1) irrespective of S treatment as compared with distinct separations among clusters for the clay soil. N fertilisation significantly (P < 0.01) reduced onion bulb pyruvic acid concentration (flavour) in both experiments. S fertilisation increased pyruvic acid concentration significantly (P < 0.01) in the glasshouse experiment, especially for the clay soil, but had no effect on pyruvic acid concentration in the field. N and S fertilisation significantly (P < 0.01) increased lachrymatory potency (pungency), but reduced total soluble solids (TSS) content in the field experiment. In the glasshouse experiment, N and S had no effect on TSS. TSS content was increased on the clay by 1.2-fold as compared with the sandy loam. Onion tissue N:water-soluble SO42- ratios of between five and eight were associated with greater %dR/R and pyruvic acid concentration values. N did not affect inner bulb tissue microbial load. In contrast, S fertilisation reduced inner bulb tissue microbial load by 80% in the field experiment and between 27% (sandy loam) and 92% (clay) in the glasshouse experiment. Overall, onion bulb quality discriminated by the E-nose responded to N, S and soil type treatments, and reflected their interactions. However, the conventional analytical and sensory measures of onion quality did not correlate with %dR/R.

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Genotype, sulphur (S) nutrition and soil-type effects on spring onion quality were assessed using a 32-conducting polymer sensor E-nose. Relative changes in sensor resistance ratio (% dR/R) varied among eight spring onion genotypes. The % dR/R was reduced by S application in four of the eight genotypes. For the other four genotypes, S application gave no change in % dR/R in three, and increased % dR/R in the other. E-nose classification of headspace volatiles by a two-dimensional principal component analysis (PCA) plot for spring onion genotypes differed for S fertilisation vs. no S fertilisation. Headspace volatiles data set clusters for cv. 'White Lisbon' grown on clay or on sandy loam overlapped when 2.9 [Mahalanobis distance value (D2) = 1.6], or 5.8-(D2 = 0.3) kg S ha-1 was added. In contrast, clear separation (D2 = 7.5) was recorded for headspace volatile clusters for 0 kg S hd-1 on clay vs. sandy loam. Addition of 5.8 kg S ha-1 increased pyruvic acid content (mmole g-1 fresh weight) by 1.7-fold on average across the eight genotypes. However, increased S from 2.9 to 5.8 kg ha-1 did not significantly (P > 0.05) influence % dR/R, % dry matter (DM) or total soluble solids (TSS) contents, but significantly (P < 0.05) increased pyruvic acid content. TSS was significantly (P < 0.05) reduced by S addition, while % DM was unaffected. In conclusion, the 32-conducting polymer E-nose discerned differences in spring onion quality that were attributable to genotype and to variations in growing conditions as shown by the significant (P < 0.05) interaction effects for % dR/R.

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The vase-life of Alstroemeria (cv. Rebecca) flowers is terminated when the tepals abscise. Abscission was accelerated by both chloroethylphosphonic acid (CEPA) and 1-aminocyclopropane-1-carboxylic acid (ACC). Petals abscised 24 h earlier compared with controls, when isolated cymes were placed in 340 nM CEPA, and earlier still when higher concentrations were used. This suggests that flowers of this Alstroemeria cultivar are very ethylene sensitive. Treatment with silver thiosulphate (STS) overcame the effects of exposure to CEPA and delayed perianth abscission of untreated isolated flowers by 3-4 days. The inclusion of 1% sucrose in the vase solution also extended longevity but not by as much as STS treatment; combined STS and sucrose treatments did not increase longevity beyond that of either treatment alone. However, removal of the young buds from the axil of the first flower was the most effective treatment to extend vase-life and encouraged the growth and development of the remaining flower. Flowers on cut inflorescences from which young axillary buds were trimmed more than doubled in fresh weight 6 days after flower opening compared with an increase of only 70-80% in those untreated or treated with STS and/or sucrose. Growth was less in isolated cymes but followed a similar pattern. The effect of STS and/or sucrose treatment was synergistic with the trimming treatment and thus the vase-life of trimmed, STS and sucrose-treated flowers was over 7 days longer than that for untreated controls. © 2003 Elsevier B.V. All rights reserved.

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Onion (Allium cepa L.) is botanically included in the Liliaceae and species are found across a wide range of latitudes and altitudes in Europe, Asia, N. America and Africa. World onion production has increased by at least 25% over the past 10 years with current production being around 44 million tonnes making it the second most important horticultural crop after tomatoes. Because of their storage characteristics and durability for shipping, onions have always been traded more widely than most vegetables. Onions are versatile and are often used as an ingredient in many dishes and are accepted by almost all traditions and cultures. Onion consumption is increasing significantly, particularly in the USA and this is partly because of heavy promotion that links flavour and health. Onions are rich in two chemical groups that have perceived benefits to human health. These are the flavonoids and the alk(en)yl cysteine sulphoxides (ACSOs). Two flavonoid subgroups are found in onion, the anthocyanins, which impart a red/purple colour to some varieties and flavanols such as quercetin and its derivatives responsible for the yellow and brown skins of many other varieties. The ACSOs are the flavour precursors, which, when cleaved by the enzyme alliinase, generate the characteristic odour and taste of onion. The downstream products are a complex mixture of compounds which include thiosulphinates, thiosulphonates, mono-, di- and tri-sulphides. Compounds from onion have been reported to have a range of health benefits which include anticarcinogenic properties, antiplatelet activity, antithrombotic activity, antiasthmatic and antibiotic effects. Here we review the agronomy of the onion crop, the biochemistry of the health compounds and report on recent clinical data obtained using extracts from this species. Where appropriate we have compared the data with that obtained from garlic (Allium sativum L.) for which more information is widely available. Copyright © 2002 John Wiley & Sons, Ltd.

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Several studies have been developed regarding health risks associated with the recreational use of beaches contaminated with domestic sewage. These wastes contain various microorganisms, including Candida tropicalis, etiologic agent of both superficial infections such as systemic, as well as indicator of fecal contamination for the environment. In this context, the objective of this study was to characterize C. tropicalis isolates from the sandy beach of Ponta Negra, Natal, Rio Grande do Norte, Brazil, regarding the expression of in vitro virulence factors, adaptation to osmotic stress and susceptibility to antifungal drugs. We analyzed 62 environmental isolates of C. tropicalis and observed a great variation between them for the various virulence factors evaluated. In general, environmental isolates were more adherent to CEBH than C. tropicalis ATCC13803 reference strain, besides the fact they were also highly biofilm producers. In relation to morphogenesis, most isolates presented wrinkled phenotype in Spider medium (34 isolates, 54.8 %). When assessing enzyme activity, most isolates had higher proteinase production than C. tropicalis ATCC13803 reference strain. In addition, 35 isolates (56.4 %) had high hemolytic activity (hemolysis index > 55). With regard to C. tropicalis resistance to osmotic stress, 85.4% of the isolates were able to grow in a liquid medium containing 15% sodium chloride, corroborating to high survival capacity described for this yeast at marine environment. Finally, with regard to sensitivity to antifungal drugs, it was observed high resistance to the azoles tested, with the occurrence of the "Low-high" phenomenon and similar effect to the paradoxical growth which occurs to the echinocandins. For the three azoles tested we verified that 15 strains were resistant (24.2 %). Some strains were also resistant to amphotericin B (14 isolates, 22.6 %), while all of them were sensitive for the echinocandins tested. Therefore, our results demonstrate that C. tropicalis isolated from the sand of northeast of Brazil can fully express virulence attributes and showed a high persistence capacity on the coastal environment, in addition of being significantly resistant to most applied antifungals in current clinical practice. This constitutes a potential health risk to visitors of this environment, especially immunocompromised individuals and those with extreme age range.

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T. gondii can infect the gut mucosa by direct invasion of epithelial cells in the small intestine and these cells may respond directly to infection promoting a local immune response. C57BL/6 mice orally infected with a high parasitic load of T.gondii are highly susceptible, presenting a lethal ileitis. Recently, it was demonstrated that pretreatment with STAg protects C57BL/6 mice against intestinal pathology in oral T. gondii infection. To investigate the mechanisms induced by STAg in the small intestine in oral T.gondii infection, BALB/c and C57BL/6 mice were treated with STAg 48 hours before oral infection with 30 ME-49 cysts and sacrificed at 8 days of infection. Previous treatment with STAg were able of decrease parasitism and pathology in peripheral organs of BALB/c and C57BL/6 mice and induced a increase in amounts of goblet cells, IgA positive cells, Paneth cells and expression of cryptidin in the small intestine of both lineages of mice, moreover BALB/c mice presented higher amount of these cells comparing with C57BL/6 mice. The results suggests that STAg is able of promoting protective mechanisms in both lineages of mice, although these protection is more evidenced in BALB/c mice, and these mechanisms could be in part mediated by increase in goblet, Paneth and local secretion of IgA in the small intestine of mice orally infected with T.gondii.

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Trypanosma cruzi is the causative agent of Chagas disease. This trypanosomiasis has become a global public health problem due to migration of Latin Americans to non-endemic countries. In Latin America with the succesful implementation of control domiciliated vector infestation and blood transfusion, the importance of congenital transmission has recently increased. Considering the tight regulation of immune system during gestation, we aimed to investigate the changes in the immune system caused by T.cruzi infection in the gestation outcome. T cruzi G and Y strain were used to infect female BALB/c mice before or after mating with non-infected male mice. The presence of vaginal plug was used as indicative of mating. Females were euthanized 8 days after confirmation of vaginal plug. We used three female control groups, only infected, only infected and non-infected and non-pregnant females. Two groups were infected before mating and other two were infected 4 days after confirmation of vaginal plug. The uterus and spleen were collected to immunochemistry, qPCR, immunofluorescence and cytokine analysis. Our results showed that despite the MMP’s identification being similarly among groups, T.cruzi higher virulent strain can impaire gestation outcome prior mating; the infection also increased cytokines like IFN-γ, IL-1β and IL-4; and leucocytes in uterine environment was altered, responding locally to systemic changes caused by T.cruzi infection. In conclusion this work suggests that T.cruzi infection can impaire gestation outcome and local response to sistemic infection was able to control the infection allowing pregnancy development in some conditions.

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The classical treatment for congenital toxoplasmosis is based on combination of sulfadiazine and pyrimethamine plus folinic acid. Due to teratogenic effects and bone marrow suppression caused by pyrimethamine, the establishment of new therapeutic targets is indispensable to minimize the undesirable effects and improve the control of the infection. Previous studies demonstrated that enrofloxacin and toltrazuril were able to control the infection triggered by Neospora caninum and Toxoplasma gondii. Therefore, the aim of this present study was evaluate the efficacy of enrofloxacin and toltrazuril in the control of T. gondii proliferation in human trophoblast cells (BeWo lineage) and in human villous explants from third trimester. BeWo cells and villous were treated with several concentrations of enrofloxacin, toltrazuril, sulfadiazine, pyrimethamine or association (sulfadiazine + pyrimethamine) in other to verify their viability by MTT or LDH assay, respectively. Next, BeWo cells were infected with T. gondii RH (2F1 clone) or ME49 strain, whereas villous were infected only with RH strain (2F1 clone), after, both cells and villous were treated or not with the same antibiotics and analyzed to T. gondii intracellular proliferation by beta-galactosidase assay (for RH strain) or blue toluidine staining (for ME49 strain). ELISA was performed in the supernatant to evaluate the cytokine profile. Enrofloxacin and toltrazuril did not change strongly the viability in cells and villous. Furthermore, the drugs decreased the parasite intracellular proliferation regardless T. gondii strain in BeWo cells and villous explants when compared to untreated and infected conditions. In BeWo cells infected by RH, enrofloxacin induced high levels of IL-6 low levels of MIF, while both cytokines were upregulated by enrofloxacin and toltrazuril in BeWo cells infected by ME49 strain. Additionally, in villous explantes, enrofloxacin induced high MIF production. Thus, enrofloxacin and toltrazuril were able to control the parasitism in BeWo cells and villous explants, and probably it occurs by modulation of immune response in these cells or tissues and direct action on parasite, but future experiments are necessary to verify this hypothesis.

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1 OBJETIVOS Evaluar el impacto de las bajas temperaturas, la interacción entre P. fluorescens (Pf) y L. monocytogenes (Lm) en biofilms (BF) mixtos y la capacidad para persistir de Lm sobre (i) la capacidad de Lm para desarrollar BF; (ii) los parámetros estructurales de los BF formados; (iii) la respuesta de las células adheridas de Lm frente al tratamiento con quitosano; (iiii) y su capacidad para recuperarse tras el tratamiento, tanto a nivel de densidad celular como estructural. Además, se pretendió valorar el quitosano como agente de limpieza y desinfección de los BF en la industria alimentaria, profundizando en su impacto sobre la estructura. 2 METODOLOGÍA Para llevar a cabo estos objetivos se seleccionaron un total de 10 cepas de Lm (6 persistentes y 3 esporádicas aisladas por Ortiz y col. (2010) de una industria cárnica y la cepa Lm Scott A como referencia) y la cepa Pf ATCC 948TM para formar BF puros, de cada especie, y mixtos, de Pf y cada una de las cepas de Lm, iniciando los cultivos a un nivel de cada una de las bacterias de 104 UFC·ml-1. Para la formación de BF se empleó un sistema en batch, en el que cupones de vidrio desechables (22x22 mm) semisumergidos actuaron como soporte para la adhesión. Los BF se desarrollaron a 20°C (BF “templados”) y 4°C (BF “fríos”). Los tratamientos con quitosano al 1% (w/v) consistieron en la inmersión durante 1h. Para la recuperación, los cupones tratados se revitalizaron en medio fresco (Trytone Soya Broth, TSB) a 20°C/48h. La densidad celular adherida antes, después y durante la revitalización se determinó mediante siembra del BF residual recogido del cupón en medios generales, o selectivos en el caso de los BF mixtos. Para la determinación de la biomasa adherida mediante densitometría (λ=520-570 nm), los BF fueron teñidos con una solución al 1‰ de azul de coomassie. Para las observaciones de la estructura mediante microscopía confocal láser de barrido (CLSM) las muestras se tiñeron con diferentes fluorocromos, procesándose las imágenes obtenidas mediante el software Imaris 8.2. El tratamiento estadístico de los datos se hizo con el software Statgraphics Centurion...

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Neospora caninum is an obligate intracellular parasite classified in the phylum Apicomplexa, characterized by the presence of the apical complex composed by micronemes proteins, rhoptries and dense granules, used by parasite during the adhesion and invasion process of the host cell. This is the mean event in infection pathogenesis generated by N. caninum and other parasites from the phylum Apicomplexa, promoting influence in the parasite biology and the interface between the parasite and its host. Therefore, molecular tools have been developed in order to identify and characterize these possible virulence factors. Thus, the present study sought to establish a specific system of genetic manipulation of N. caninum, searching for the improvement of the genetics manipulation of this parasite. So, we developed genetically depleted N. caninum to Rop9 rhoptry using the pU6-Universal CRISPR-Cas9 plasmid of T. gondii modified by the insertion of Ku80. The Rop9 depleted parasite showed important during initial phase of invasion and replication of the parasite, however it was not characterized as a potential virulence fator for N. caninum. Furthermore, T. gondii proteins were expressed in N. caninum by the use of specific vectors for this parasite, showing an heterologous system for the study of Toxoplasma proteins, due to the fact that Gra15 or Gra24 of type II T. gondii and Rop16 of type I T. gondii were expressed in N. caninum tachyzoites in a stable way and keept its biological phenotype, as already presented the former parasite, that naturaly expresses these proteins. In addition, it was observed that N. caninum induced an inflammasome activation through NLRP3, ASC and Caspase-1. IL-1R/MyD88 demonstrated an indirect pathway in the control of parasite replication. Furthermore, it was observed that this activation is dependent of the potassium efflux and that different strains of N. caninum keep this activation profile. However, T. gondii strains block this activation, making necessary a prior signal in order to active the inflamosome pathway. Type I T. gondii Rop16 was identified as responsible for blocking this activation, in a dependent way to the STAT3 activation. Therefore, the development of molecular tools and their application in N. caninum may prove to be useful to identify and characterize virulent factors involved in the pathogenesis by these two protozoans.