292 research outputs found

    Allergenicity reduction of cow's milk proteins using latex peptidases

    Get PDF
    The present study evaluated four laticifer fluids as a novel source of peptidases capable of hydrolyzing proteins in cow´s milk. The latex peptidases from Calotropis procera (CpLP), Cryptostegia grandiflora (CgLP), and Carica papaya (CapLP) were able to perform total hydrolysis of caseins after 30 min at pH 6.5, as confirmed by a significant reduction in the residual antigenicity. Casein hydrolysis by Plumeria rubra latex peptidases (PrLP) was negligible. Moreover, whey proteins were more resistant to proteolysis by latex peptidases; however, heat pretreatment of the whey proteins enhanced the degree of hydrolysis and reduced the residual antigenicity of the hydrolysates. The in vivo assays show that the cow´s milk proteins hydrolysed by CgLP and CapLP exhibited no immune reactions in mice allergic to cow´s milk, similar to a commercial partially hydrolysed formula. Thus, these peptidases are promising enzymes for the development of novel hypoallergenic formulas for children with a milk allergy.Fil: Oliveira, João P. B.. Universidade Estadual do Ceará; BrasilFil: Candreva, Ángela María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Estudios Inmunológicos y Fisiopatológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios Inmunológicos y Fisiopatológicos; ArgentinaFil: Rizzo, Gaston Pascual. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Estudios Inmunológicos y Fisiopatológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios Inmunológicos y Fisiopatológicos; ArgentinaFil: Ramos, Márcio V.. Universidade Estadual do Ceará; BrasilFil: Oliveira, Jefferson S.. Universidade Estadual do Ceará; BrasilFil: Oliveira, Hermógenes D.. Universidade Federal Do Piaui.; BrasilFil: Ary, Maria B.. Universidade Estadual do Ceará; BrasilFil: Docena, Guillermo H.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Estudios Inmunológicos y Fisiopatológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios Inmunológicos y Fisiopatológicos; ArgentinaFil: Freitas, Cleverson D. T.. Universidade Federal Do Ceara; Brasi

    Galling inducing insects associated with a tropical shrub : The role of resource concentration and species interactions

    Get PDF
    Os insetos galhadores são herbívoros sedentários sofsticados que apresentam alto nível de especialização com sua planta hospedeira, mas sua performance pode ser afetada por fatores bióticos e abióticos. Neste estudo nós testamos duas hipóteses: a) plantas que possuem maior número de vizinhos coespecífcos apresentam maior riqueza e abundância de insetos galhadores, e b) a competição interespecífca é uma força capaz de molda a organização das comunidades de insetos herbívoros associados com uma planta super-hospedeira. O sistema Copaifera oblongifolia (Fabaceae)/insetos galhadores associados foi usado para testar estas hipóteses. Os trabalhos de campo foram desenvolvidos em áreas de Cerrado do norte de Minas Gerais, Brasil. Para testar a primeira hipótese, nós avaliamos, com modelos lineares generalizados de efeitos mistos, os efeitos do número de vizinhos coespecífcos na riqueza e abundância de galhas associadas com 67 arbustos de C. oblongifolia pertencentes a duas populações. Para testar a segunda hipótese, nós usamos modelos nulos para avaliar se um arbusto de C. oblongifolia colonizado por uma espécie de inseto galhador é preferido ou evitado por uma outra espécie de inseto galhador. Um total de 2901 insetos galhadores pertencentes a 15 diferentes espécies foi coletado nos 67 arbustos de C. oblongifolia. Nós observamos uma relação negativa entre o número de vizinhos coespecífcos e a riqueza e a abundância de insetos galhadores associados com C. oblongifolia. Assim, nossos resultados não corroboraram a hipótese da concentração do recuro e nós usamos a teoria da diluição do recurso para explicar este resultado. Nossos resultados também mostraram que o padrão de co-ocorrência dos insetos galhadores na planta hospedeira não diferiu daquele esperado pelo acaso. Portanto, a estrutura da comunidade de insetos galhadores associada com C. oblongifolia não pode ser atribuída a eventos determinísticos com a competição interespecífca.Gall-forming insects are sophisticated sedentary herbivores that present high level of specificity with host plant, but their performance can be affected by biotic and abiotic factors. In this study we have tested two predictions: a) plants that have a greater number of conspecific neighbors have greater richness and abundance of gall-forming insects, and b) interspecific competition is a force capable of shaping the organization of gall-forming insect communities in super-host plants. We used the Copaifera oblongifolia (Fabaceae)/galling insects’ system to test these predictions. Fieldwork was carried out in areas of Cerrado (Brazilian Savanna) in northern Minas Gerais, Brazil. To test the first hypothesis, we evaluated with generalized linear mixed models, the effects of the number of conspecific neighbors on the richness and abundance of galls associated with 67 C. oblongifolia individual plants belonging to two populations. To test the second hypothesis, we used null models to evaluate whether a plant of C. oblongifolia colonized by a species of gall is preferred or avoided by another species of gall. A total of 2901 gall-forming insects belonging to 15 species were collected from the host plant C. oblongifolia. We observed negative relationships between the number of conspecific neighbors and the abundance and richness of gall-forming insects associated C. oblongifolia. Thus, our data did not support the resource concentration hypothesis. Instead, we used the resource dilution theory to explain the negative relation between resource concentration and frequency of attack by galling insects. Our results also showed that the co-occurrence pattern of gall-forming insects in the host plant did not differ from those expected by chance. Therefore, the structure of the gall-forming insect community associated to single C. oblongifolia plants cannot be attributed to deterministic factors such as interspecific competition

    Allergenicity reduction of cow's milk proteins using latex peptidases

    Get PDF
    The present study evaluated four laticifer fluids as a novel source of peptidases capable of hydrolyzing proteins in cow’s milk. The latex peptidases from Calotropis procera (CpLP), Cryptostegia grandiflora (CgLP), and Carica papaya (CapLP) were able to perform total hydrolysis of caseins after 30 min at pH 6.5, as confirmed by a significant reduction in the residual antigenicity. Casein hydrolysis by Plumeria rubra latex peptidases (PrLP) was negligible. Moreover, whey proteins were more resistant to proteolysis by latex peptidases; however, heat pretreatment of the whey proteins enhanced the degree of hydrolysis and reduced the residual antigenicity of the hydrolysates. The in vivo assays show that the cow’s milk proteins hydrolysed by CgLP and CapLP exhibited no immune reactions in mice allergic to cow’s milk, similar to a commercial partially hydrolysed formula. Thus, these peptidases are promising enzymes for the development of novel hypoallergenic formulas for children with a milk allergy.Instituto de Estudios Inmunológicos y Fisiopatológico

    Renormalization-group study of Anderson and Kondo impurities in gapless Fermi systems

    Full text link
    Thermodynamic properties are presented for four magnetic impurity models describing delocalized fermions scattering from a localized orbital at an energy-dependent rate Γ(ϵ)\Gamma(\epsilon) which vanishes precisely at the Fermi level, ϵ=0\epsilon = 0. Specifically, it is assumed that for small ϵ|\epsilon|, Γ(ϵ)ϵr\Gamma(\epsilon)\propto|\epsilon|^r with r>0r>0. The cases r=1r=1 and r=2r=2 describe dilute magnetic impurities in unconventional superconductors, ``flux phases'' of the two-dimensional electron gas, and zero-gap semiconductors. For the nondegenerate Anderson model, the depression of the low-energy scattering rate suppresses mixed valence in favor of local-moment behavior, and leads to a marked reduction in the exchange coupling on entry to the local-moment regime, with a consequent narrowing of the range of parameters within which the impurity spin becomes Kondo-screened. The relationship between the Anderson model and the exactly screened Kondo model with power-law exchange is examined. The intermediate-coupling fixed point identified in the latter model by Withoff and Fradkin (WF) has clear signatures in the thermodynamic properties and in the local magnetic response of the impurity. The underscreened, impurity-spin-one Kondo model and the overscreened, two-channel Kondo model both exhibit a conditionally stable intermediate-coupling fixed point in addition to unstable fixed points of the WF type. In all four models, the presence or absence of particle-hole symmetry plays a crucial role.Comment: 44 two-column REVTex pages, 31 epsf-embedded EPS figures. MINOR formatting changes. To appear in Phys. Rev.

    Diversity of ferns and lycophytes in Brazil

    Get PDF
    This compilation of ferns and lycophytes in Brazil is an update of the one published in 2010 in Catálogo de Plantas e Fungos do Brasil. The methodology consisted in collecting data from regional checklists, taxonomic revisions, and selected databases. Invited specialists improved the list accessing a website housed at the Jardim Botânico do Rio de Janeiro. The results show 1,253 species: 1,111 of ferns and 142 of lycophytes. This number is 6.5% higher than the previous one (1,176 spp.). The percentage of endemic species decreased from 38.2% to 36.7%. We recognized 36 families and 133 genera (vs. 33 families, 121 genera in 2010). The 10 most diverse families are Pteridaceae (196 spp.), Dryopteridaceae (179), Polypodiaceae (164), Hymenophyllaceae (90), Thelypteridaceae (86), Aspleniaceae (78), Lycopodiaceae (64), Selaginellaceae (55), Anemiaceae (51), and Cyatheaceae (45). The three most diverse genera are still Elaphoglossum (87 spp.), Thelypteris (85), and Asplenium (74). The richest phytogeographic domain continues to be in the Atlantic Rainforest with 883 species which also has the largest number of endemic and threatened species, followed by the Amazon Rainforest (503), Cerrado (269), Pantanal (30), Caatinga (26), and Pampa (eight). Minas Gerais remains as the richest state (657 spp. vs. 580 in 2010).Esta compilação de samambaias e licófitas do Brasil é uma atualização daquela de 2010, no Catálogo de Plantas e Fungos do Brasil. A metodologia consistiu na reunião de dados de listas regionais, revisões de grupos e bancos de dados selecionados. Especialistas convidados melhoraram a lista através do acesso a um sítio da web do Jardim Botânico do Rio Janeiro. Os resultados apontam uma diversidade de 1.253 espécies, sendo 1.111 samambaias e 142 licófitas. Este número é 6,5% maior que o anterior (1.176 espécies). As espécies endêmicas decresceram de 38,2% para 36,7%. Foram reconhecidas 36 famílias e 133 gêneros (vs. 33 famílias, 121 gêneros em 2010). As dez famílias mais diversas são: Pteridaceae (196 espécies), Dryopteridaceae (179), Polypodiaceae (164), Hymenophyllaceae (90), Thelypteridaceae (86), Aspleniaceae (78), Lycopodiaceae (64), Selaginellaceae (55), Anemiaceae (51) e Cyatheaceae (45). Os três gêneros mais diversos continuam sendo Elaphoglossum (87 espécies), Thelypteris (85) e Asplenium (74). O Domínio Fitogeográfico mais rico continua sendo a Mata Atlântica (883 espécies) e também com mais espécies endêmicas e ameaçadas, seguido pela Amazônia (503 espécies), Cerrado (269), Pantanal (30), Caatinga (26) e Pampa (oito). Minas Gerais permanece como o estado com maior riqueza (657 espécies vs. 580 em 2010)

    Prime Focus Spectrograph (PFS) for the Subaru Telescope: Overview, recent progress, and future perspectives

    Full text link
    PFS (Prime Focus Spectrograph), a next generation facility instrument on the 8.2-meter Subaru Telescope, is a very wide-field, massively multiplexed, optical and near-infrared spectrograph. Exploiting the Subaru prime focus, 2394 reconfigurable fibers will be distributed over the 1.3 deg field of view. The spectrograph has been designed with 3 arms of blue, red, and near-infrared cameras to simultaneously observe spectra from 380nm to 1260nm in one exposure at a resolution of ~1.6-2.7A. An international collaboration is developing this instrument under the initiative of Kavli IPMU. The project is now going into the construction phase aiming at undertaking system integration in 2017-2018 and subsequently carrying out engineering operations in 2018-2019. This article gives an overview of the instrument, current project status and future paths forward.Comment: 17 pages, 10 figures. Proceeding of SPIE Astronomical Telescopes and Instrumentation 201

    Biological Function and Molecular Mapping of M Antigen in Yeast Phase of Histoplasma capsulatum

    Get PDF
    Histoplasmosis, due to the intracellular fungus Histoplasma capsulatum, can be diagnosed by demonstrating the presence of antibodies specific to the immunodominant M antigen. However, the role of this protein in the pathogenesis of histoplasmosis has not been elucidated. We sought to structurally and immunologically characterize the protein, determine yeast cell surface expression, and confirm catalase activity. A 3D-rendering of the M antigen by homology modeling revealed that the structures and domains closely resemble characterized fungal catalases. We generated monoclonal antibodies (mAbs) to the protein and determined that the M antigen is present on the yeast cell surface and in cell wall/cell membrane preparations. Similarly, we found that the majority of catalase activity was in extracts containing fungal surface antigens and that the M antigen is not significantly secreted by live yeast cells. The mAbs also identified unique epitopes on the M antigen. The localization of the M antigen to the cell surface of H. capsulatum yeast and the characterization of the protein's major epitopes have important implications since it demonstrates that although the protein may participate in protecting the fungus against oxidative stress it is also accessible to host immune cells and antibody

    The OSU1/QUA2/TSD2-Encoded Putative Methyltransferase Is a Critical Modulator of Carbon and Nitrogen Nutrient Balance Response in Arabidopsis

    Get PDF
    The balance between carbon (C) and nitrogen (N) nutrients must be tightly coordinated so that cells can optimize their opportunity for metabolism, growth and development. However, the C and N nutrient balance perception and signaling mechanism remains poorly understood. Here, we report the isolation and characterization of two allelic oversensitive to sugar1 mutants (osu1-1, osu1-2) in Arabidopsis thaliana. Using the cotyledon anthocyanin accumulation and root growth inhibition assays, we show that the osu1 mutants are more sensitive than wild-type to both of the imbalanced C/N conditions, high C/low N and low C/high N. However, under the balanced C/N conditions (low C/low N or high C/high N), the osu1 mutants have similar anthocyanin levels and root lengths as wild-type. Consistently, the genes encoding two MYB transcription factors (MYB75 and MYB90) and an Asn synthetase isoform (ASN1) are strongly up-regulated by the OSU1 mutation in response to high C/low N and low C/high N, respectively. Furthermore, the enhanced sensitivity of osu1-1 to high C/low N with respect to anthocyanin accumulation but not root growth inhibition can be suppressed by co-suppression of MYB75, indicating that MYB75 acts downstream of OSU1 in the high C/low N imbalance response. Map-based cloning reveals that OSU1 encodes a member of a large family of putative methyltransferases and is allelic to the recently reported QUA2/TSD2 locus identified in genetic screens for cell-adhesion-defective mutants. Accumulation of OSU1/QUA2/TSD2 transcript was not regulated by C and N balance, but the OSU1 promoter was slightly more active in the vascular system. Taken together, our results show that the OSU1/QUA2/TSD2-encoded putative methyltransferase is required for normal C/N nutrient balance response in plants
    corecore