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The production and characterization of Arabidopsis plants containing a transgene in which the Arabidopsis tAPX is inserted in antisense orientation, is described. tAPX activity in these transgenic tAPX plants is around 50% of control level. The tAPX antisense plants are phenotypically indistinguishable from control plants under normal growth conditions; they show, however, enhanced sensitivity to the O2–-generating herbicide, Paraquat. Interestingly, the tAPX antisense plants show enhanced symptoms of damage when cell death is triggered through treatment with the nitric oxide-donor, SNP. These results are in accordance with the ones recently obtained with transgenic plants overexpressing tAPX; altogether, they suggest that tAPX, besides the known ROS scavenging role, is also involved in the fine changes of H2O2 concentration during signaling events. 相似文献
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Purpose: To determine levels of urinary aflatoxin M1 (AFM1) in children and correlate the concentrations with previously reported aflatoxin albumin adduct (AF-alb) levels in these children.Materials and methods: Matched urine and blood samples were collected from 84 Tanzanian children aged 6–14 months old. From 31 children in one village (Kigwa), samples were collected at three time points six months apart. Samples were collected from 31 and 22 children from two different regions at the second time point only. Urinary AFM1 was measured using a commercial enzyme-linked immunosorbent assay (ELISA) kit with a modified protocol to improve sensitivity. AF-alb was measured using an established ELISA method.Results: The relative ranking of the three villages for exposure to aflatoxin based on either AFM1 or AF-alb biomarker measurements was the same. In Kigwa village, both AFM1 and AF-alb levels were higher at six months post-harvest compared to baseline. However, at the next visit, the AFM1 levels dropped from a GM (interquartile range) of 71.0 (44.7, 112.6) at visit two to 49.3 (31.5, 77.3) pg/ml urine, whereas AF-alb levels increased from 47.3 (29.7, 75.2) to 52.7 (35.4, 78.3) pg/mg albumin between these two visits, reflecting the fact that AFM1 measures short-term exposure, whereas AF-alb measures longer term exposure. There was a correlation between AFB1 intake and AFM1 excretion (r=?0.442, p?≤?0.001).Conclusions: Urinary AFM1 is a good biomarker for AFB1 exposure in Tanzanian children, reflecting geographical and temporal variations in exposure to this foodborne toxin. 相似文献
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Fabricio Fernandes Fontana Celso Tadeu Barbosa dos Santos Flavia Maria Esteves Ademir Rocha Geisa Ferreira Fernandes Cristiane Candida do Amaral Marcos Abel Domingues Zoilo Pires De Camargo Mario León Silva-Vergara 《Mycopathologia》2010,169(3):159-165
There is some evidence that dogs can be naturally infected by Paracoccidioides brasiliensis in endemic areas of paracoccidioidomycosis. In order to evaluate canine infection with this fungus, a survey with 149 urban
and 126 rural dogs was carried out using ELISA and intradermal tests with the gp43 antigen of P. brasiliensis in Uberaba, Minas Gerais state of Brazil. Forty-one out of 149 urban dogs were euthanatized and had their lungs, liver and
spleen removed. One slice from each viscera was processed for histopathological examination and the remaining was homogenized and then cultivated on mycobiotic agar
at room temperature and Fava-Netto medium at 35°C and observed for 12 weeks. Of urban dogs, 75 (50.3%) were small adult females,
56 (36%) were strays, while 93 (64%) had been donated to the municipal zoonosis control center. Nine (6.2%) had a positive
intradermal test without statistical differences regarding gender, race, nutritional status or origin. No colonies with microscopic
or morphology appearances resembling P. brasiliensis were isolated, nor granulomatous process or fungal structures were observed from histopathological examination. Eighty (53.6%)
of the urban dogs presented seroreactivity, without statistical differences regarding gender, race, nutritional state, origin,
or positive intradermal test. Of 126 rural dogs, 102 (80.5%) presented antibodies against gp43 antigen, and this was statistically
significant in relation to the reactivity detected in urban dogs (P = 0.0001). Thus, dogs are commonly infected with P. brasiliensis, but they probably present natural resistance to develop paracoccidioidomycosis. 相似文献
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Aline Candida Ribeiro Andrade-Silva André Nemésio Favízia Freitas de Oliveira Fabio Santos Nascimento 《Neotropical Entomology》2012,41(4):296-305
The spatial and temporal distribution of organisms is a fundamental aspect of biological communities. The present study focused on three remnants of arboreal Caatinga in northeastern Brazil between May, 2009 and April, 2010. A total of 627 euglossine males were captured in traps baited with artificial aromatic compounds. The specimens belonged to 14 species and four genera: Euglossa Latreille, Eulaema Lepeletier, Eufriesea Cockerell, and Exaerete Hoffmannsegg. Eulaema nigrita Lepeletier (41.6), Euglossa carolina Nemésio (15.3%), Eulaema marcii Nemésio (13.6%), and Euglossa melanotricha Moure (12.8%) were the most common species sampled. The distribution of collected specimens per fragment was as follows: Braúna (280?ha)??259 individuals belonging to 14 species; Cambuí (179?ha)??161 individuals from eight species; and Pindoba (100?ha)??207 individuals represented by seven species. Braúna had the highest diversity (H???=?1.91) and estimated species richness. The largest fragment was the main source of the observed variation in species richness and abundance, indicating a non-random pattern of spatial distribution. The analysis of environmental factors indicated that seasonal variation in these factors was the principal determinant of species occurrence and abundance. 相似文献
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Mellado MC Peixoto C Cruz PE Carrondo MJ Alves PM 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2008,874(1-2):89-94
Rotavirus VP7 is a glycoprotein that forms the viral capsid outerlayer and is essential to the correct assembly of triple-layered rotavirus-like particles (RLPs). In this work, a novel purification strategy was designed to allow obtaining highly pure monomeric VP7 required for the RLPs in vitro assembly. VP7 production kinetics in baculovirus-insect cells at cell concentration at infection (CCI) of 1x10(6)cellsmL(-1) was compared in terms of VP7/glycoprotein 64 (gp64) ratio at different multiplicity of infection (MOI). The best productivity was achieved at MOI of 0.1plaque forming unit (pfu)cell(-1) and time of harvest of 80h post-infection. After preliminary clarification steps, the proteins eluted from Concanavalin A were concentrated and loaded onto size exclusion chromatography. The polishing step was anion exchange chromatography with Mono Q. The high resolution of this column resulted in separation of monomers from dimers of VP7. Overall, the purification protocol yielded high level of purity (>90%). Purified VP7 was characterized by MALDI-TOF mass spectrometry and SDS-capillary gel electrophoresis. The MW and apparent MW were determined as 31.6 and 39kDa, respectively, confirming the efficacy of the proposed purification strategy that now enables RLPs assembly studies. 相似文献
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Alcides AP Brazier JS Pinto LJ Balassiano IT Boente RF de Paula GR Ferreira EO Avelar KE Miranda KR Ferreira MC Domingues RM 《Antonie van Leeuwenhoek》2007,92(1):53-59
A total of 35 Brazilian isolates of Clostridium difficile from faecal stools and four isolates from hospital environments were analyzed by PCR ribotyping. A whole cell protein profile
(as an alternative for serogrouping), in vitro toxin production and susceptibility to vancomycin, metronidazole and clindamycin
were also investigated. All strains were typeable by both phenotypic and genotypic methods, and a total of 13 different PCR
ribotypes were identified, of which seven (132, 133, 134, 135, 136, 142 and 143) were considered new types and accounted for
78.5% of all samples evaluated (including hospital environments). A non-toxigenic C. difficile PCR ribotype 133 was detected in all children groups examined (inpatients, outpatients and healthy children), whilst toxigenic
PCR ribotypes 015, 131, 134 and 135 were associated mostly with symptomatic children. Serogroups G and D were disseminated
both in patients from the community and from the pediatric hospital, with group G prevalent among outpatient children. All
strains were susceptible to vancomycin and metronidazole but high levels of resistance to clindamycin were found, especially
among serogroups G and D. Co-existence of different ribotypes and serogroups in the same individual was observed. The new
seven ribotypes found in this investigation may represent strains characteristic of this region of Brazil. 相似文献
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Proteomic analysis of somatic embryogenesis in <Emphasis Type="Italic">Vitis vinifera</Emphasis> 总被引:1,自引:0,他引:1
Two dimensional gel electrophoresis coupled to mass spectrometry has been used to study the somatic embryogenesis in Vitis vinifera, by comparing embryogenic and non embryogenic calluses of the Thompson seedless cv. More than 1,000 spots were reproducibly resolved in colloidal Coomassie brilliant blue stained gels over a pI nonlinear range of 3–10 in the first dimension and using homogeneous 12.5% polyacrylamide gels in the second dimension. The
expression pattern of 35 spots differed significantly between the two samples. These spots were processed by mass spectrometry
analysis and the protein identity was assigned by using both the non-redundant protein and EST databases. Several responsive
proteins, some already known to be involved in the somatic embryogenesis process while others, for the first time put into
relation with this process, have been described. Moreover, they have been subdivided in functional categories, and their putative
role is discussed in terms of their relevance in the somatic embryogenesis process. 相似文献