1,258 research outputs found

    Microbial community dynamics in diesel waste biodegradation using sequencing batch bioreactor operation mode (SBR)

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    The dynamic of molecular microbial community during diesel waste biodegradation was investigated. The waste was treated in bioreactors operated in sequencing batch operation mode (SBR) in four cycles of 72 h, using optimized setpoints (pH, initial waste load, C:N ratio, aeration). Optimal conditions allowed the system to reach biodegradation of 53.3, 96.0, 76.2 and 75.0% at the end of cycles one, two three and four, respectively. Oxygen uptake rate (OUR) indicated increases in microbial activity from cycle one to cycle two (124.9 to 252.9 mgO2/L/h) and decreases in cycles three and four (120.4 to 108.8 mgO2/L/h, respectively). Investigations of microbial diversity showed changes in the microbial community members at the end of the cycle one. Significant reductions in the relative ecotoxicity were observed beginning with cycle two, and the reductions extended until the end of process. The SBR operation mode proved to be an efficient method for treating the diesel waste, and the process allowed for relevant reductions in the hydrocarbon content of the waste along with an increase in its environmental quality. Changes in the microbial members are evidence of the synergistic action of the microbiota in the process.Key words: Microbial diversity, denaturing gradient gel electrophoresis, sequencing batch, biodegradation

    Impaired hepatic drug and steroid metabolism in congenital adrenal hyperplasia due to P450 oxidoreductase deficiency

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    Objective: Patients with congenital adrenal hyperplasia due to P450 oxidoreductase (POR) deficiency(ORD) present with disordered sex development and glucocorticoid deficiency. This is due to disruption of electron transfer from mutant POR to microsomal cytochrome P450 (CYP) enzymes that play a key role in glucocorticoid and sex steroid synthesis. POR also transfers electrons to all major drugmetabolizing CYP enzymes, including CYP3A4 that inactivates glucocorticoid and oestrogens. However, whether ORD results in impairment of in vivo drug metabolism has never been studied. Design:We studied an adult patient with ORD due to homozygous POR A287P, the most frequent POR mutation in Caucasians, and her clinically unaffected, heterozygous mother. The patient had received standard dose oestrogen replacement from 17 until 37 years of age when it was stopped after she developed breast cancer. Methods: Both subjects underwent in vivo cocktail phenotyping comprising the oral administration of caffeine, tolbutamide, omeprazole, dextromethorphan hydrobromide and midazolam to assess the five major drug-metabolizing CYP enzymes. We also performed genotyping for variant CYP alleles known to affect drug metabolism. Results: Though CYP enzyme genotyping predicted normal or high enzymatic activities in both subjects, in vivo assessment showed subnormal activities of CYP1A2, CYP2C9, CYP2D6 and CYP3A4 in the patient and of CYP1A2 and CYP2C9 in her mother. Conclusions: Our results provide in vivo evidence for an important role of POR in regulating drug metabolism and detoxification. In patients with ORD, in vivo assessment of drug-metabolizing activities with subsequent tailoring of drug therapy and steroid replacement should be considered

    Geographical distribution patterns and niche modeling of the iconic leafcutter ant Acromyrmex striatus (Hymenoptera: Formicidae).

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    Ants are considered one of the most successful groups in the planet?s evolutionary history. Among them highlights the fungus-farming ants of the genera Atta and Acromyrmex that occur throughout most of the Americas. Within the Acromyrmex genus, the species A. striatus distinguishes from other Acromyrmex species as its morphology and karyotype differ from its congeners. This species is found in open environments of dry climate in the southern States of Brazil, Argentina, Paraguay and Uruguay; however, little is known about the current distribution of the species. This article aimed to investigate the current distribution of the species by compiling its known distribution and discussing its distributional range. To achieve this, published and unpublished data obtained through a literature search and active collections in various locations were compiled. Published and unpublished data revealed that 386 colonies were recorded, distributed across four countries where its occurrence is known. Environmental factors, such as temperature, humidity, soil type and vegetation, as well as historical geological and climate events that have modified Earth?s surface may have influenced species distribution patterns. In the Neotropics, the environmental factors that most impacted the distribution of species were the glaciation periods that occurred in the Quaternary, leading to a great migratory process. These factors may have contributed to the current geographical distribution of A. striatus

    Transition of plasmodium sporozoites into liver stage-like forms is regulated by the RNA binding protein pumilio

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    Many eukaryotic developmental and cell fate decisions that are effected post-transcriptionally involve RNA binding proteins as regulators of translation of key mRNAs. In malaria parasites (Plasmodium spp.), the development of round, non-motile and replicating exo-erythrocytic liver stage forms from slender, motile and cell-cycle arrested sporozoites is believed to depend on environmental changes experienced during the transmission of the parasite from the mosquito vector to the vertebrate host. Here we identify a Plasmodium member of the RNA binding protein family PUF as a key regulator of this transformation. In the absence of Pumilio-2 (Puf2) sporozoites initiate EEF development inside mosquito salivary glands independently of the normal transmission-associated environmental cues. Puf2- sporozoites exhibit genome-wide transcriptional changes that result in loss of gliding motility, cell traversal ability and reduction in infectivity, and, moreover, trigger metamorphosis typical of early Plasmodium intra-hepatic development. These data demonstrate that Puf2 is a key player in regulating sporozoite developmental control, and imply that transformation of salivary gland-resident sporozoites into liver stage-like parasites is regulated by a post-transcriptional mechanism

    PHENOLIC OXYDATION, TYPE OF EXPLANT AND NUTRITIVE MEDIA IN Peltophorum dubium (SPRENG.) TAUB.'S IN VITRO ESTABLISHMENT

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    A canaf\uedstula, Peltophorum dubium (Spreng.) Taub. \ue9 uma esp\ue9cie florestal nativa e com ampla dispers\ue3o geogr\ue1fica, desempenhando um papel pioneiro nas \ue1reas abertas, em capoeiras e matas degradadas. Apresenta um r\ue1pido crescimento e se adapta facilmente, sendo muito recomendada para reflorestamento homog\ueaneo. A madeira \ue9 utilizada em constru\ue7\uf5es civis, ind\ufastria de m\uf3veis, constru\ue7\ue3o naval e militar. A micropropaga\ue7\ue3o \ue9 uma t\ue9cnica utilizada com bastante sucesso, apresentando, entre outras vantagens, um r\ue1pido aumento no n\ufamero de plantas geneticamente id\ueanticas partindo de plantas selecionadas. Os objetivos do trabalho s\ue3o avaliar a influ\ueancia da luz no controle da oxida\ue7\ue3o fen\uf3lica dos explantes de canaf\uedstula (Peltophorum dubium (Spreng.), determinar o meio nutritivo e o tipo de explante mais adequado para o estabelecimento in vitro de canaf\uedstula (Peltophorum dubium (Spreng.). Foram realizados dois experimentos. No primeiro, \ue1pices caulinares foram cultivados em meio base MS a 25 \ub1 3\ub0C, por 7 dias no escuro e, posteriormente, sob fotoper\uedodo de 16 horas de luz e intensidade luminosa de 20 \u3bcmol.m2.s-1, fornecida por l\ue2mpada fluorescente branca durante 21 dias ou permaneceram na c\ue2mara de crescimento com exposi\ue7\ue3o \ue0 luz durante todo o experimento. Foi empregado o delineamento inteiramente casualizado com cinco repeti\ue7\uf5es contendo quatro unidades experimentais (UE). A oxida\ue7\ue3o fen\uf3lica foi observada ap\uf3s 21 dias de cultivo. N\ue3o ocorreu oxida\ue7\ue3o fen\uf3lica em nenhum dos tratamentos analisados. No segundo experimento, \ue1pices caulinares e segmentos nodais foram cultivados em meio base MS e meio WPM. Os explantes foram mantidos em sala de crescimento com fotoper\uedodo de 16 horas de luz e intensidade luminosa de 20 \u3bcmol.m2.s-1, fornecidas por l\ue2mpada fluorescente branca fria e temperatura de 25 \ub1 3\ub0C. A UE foi composta por um frasco de vidro de 150 mL contendo 30 mL de meio nutritivo e um explante. O delineamento experimental utilizado foi o inteiramente casualizado, em esquema fatorial 2 x 2 (meio nutritivo e tipo de explante) com cinco repeti\ue7\uf5es por tratamento, cada repeti\ue7\ue3o consistindo de quatro UE. Aos 49 dias de cultivo avaliaram-se as seguintes vari\ue1veis: sobreviv\ueancia, estabelecimento, presen\ue7a de raiz, presen\ue7a de calos, n\ufamero de n\uf3s, n\ufamero de folhas e altura da parte a\ue9rea (mm). Os dados de presen\ue7a de raiz, presen\ue7a de calo, sobreviv\ueancia e estabelecimento foram analisados pelo teste qui-quadrado. As demais vari\ue1veis foram submetidas \ue0 an\ue1lise de vari\ue2ncia. Neste experimento, o meio base MS \ue9 mais eficiente que o WPM no estabelecimento in vitro de canaf\uedstula (Peltophorum dubium (Spreng.). N\ue3o existem diferen\ue7as entre a utiliza\ue7\ue3o dos explantes \ue1pice caulinar e segmento nodal.Peltophorum dubium (Spreng.) Taub. is a heliopylous, a native forest species with wide geografic dispersion, occuping a pioneer role in open areas, hencoops and degradated woods. Showing a fast growth, it adapts easily and it is highly recommended for homogeneous reforest. The timber is used in industrial furniture, civilian, naval and military constructions. The micropropagation is a technique used succesfully, allowing a fast increase of the number of plants genetically identical considering the superior types. The work's objectives are: to evaluate the effect of the light on phenolic oxydation and to determinate the most appropriate nutritive medium and type of explant for in vitro establishment of Peltophorum dubium. Two experiments were accomplished. In the first one, apical segments were cultivated in MS base medium at 25\ub13\ub0C, during seven days in the dark; after that, they remained in the presence of light (photoperiod of 16h) for 14 days. In the other treatment, the explants stayed under light during the whole experiment (21 days). Completely random design with five replicates and four experimental units (EU) were used. Phenolic oxydation did not occur in any of the analyzed treatments. In the second assay, apical segments and nodal segments were cultivated in MS base medium and WPM medium. The explants stayed in the growth room during 16h of photoperiod and luminous intensity of 20 \u3bcmol.m2.s-1, supplied with cool white fluorescent lamps, at 25\ub13\ub0C. The EU was composed by one 150mL flask with 30mL of nutritive medium and one explant. Completely random design with factorial outline 2 x 2 (nutritive medium and type of explant) and five replicates by treatment, each replicate with four EU, were used. After 49 days, the following elements were evaluated: survival, establishment, root presence, calli presence, numbers of nodes, number of leaves and shoot height (mm). The data of survival, establishment, root presence and calli presence were analyzed for qui-quadrado test. The other variables were submitted to variance analysis. In this experiment, MS base medium is more efficient than WPM medium in the in vitro establishment of Peltophorum dubium. There are no statistical differences among apical segment and nodal segment

    B Cells Regulate Neutrophilia during Mycobacterium tuberculosis Infection and BCG Vaccination by Modulating the Interleukin-17 Response

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    We have previously demonstrated that B cells can shape the immune response to Mycobacterium tuberculosis, including the level of neutrophil infiltration and granulomatous inflammation at the site of infection. The present study examined the mechanisms by which B cells regulate the host neutrophilic response upon exposure to mycobacteria and how neutrophilia may influence vaccine efficacy. To address these questions, a murine aerosol infection tuberculosis (TB) model and an intradermal (ID) ear BCG immunization mouse model, involving both the μMT strain and B cell-depleted C57BL/6 mice, were used. IL (interleukin)-17 neutralization and neutrophil depletion experiments using these systems provide evidence that B cells can regulate neutrophilia by modulating the IL-17 response during M. tuberculosis infection and BCG immunization. Exuberant neutrophilia at the site of immunization in B cell-deficient mice adversely affects dendritic cell (DC) migration to the draining lymph nodes and attenuates the development of the vaccine-induced Th1 response. The results suggest that B cells are required for the development of optimal protective anti-TB immunity upon BCG vaccination by regulating the IL-17/neutrophilic response. Administration of sera derived from M. tuberculosis-infected C57BL/6 wild-type mice reverses the lung neutrophilia phenotype in tuberculous μMT mice. Together, these observations provide insight into the mechanisms by which B cells and humoral immunity modulate vaccine-induced Th1 response and regulate neutrophila during M. tuberculosis infection and BCG immunization. © 2013 Kozakiewicz et al

    Neutrophils Reduce the Parasite Burden in Leishmania (Leishmania) amazonensis-Infected Macrophages

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    Background: Studies on the role of neutrophils in Leishmania infection were mainly performed with L. (L) major, whereas less information is available for L. (L) amazonensis. Previous results from our laboratory showed a large infiltrate of neutrophils in the site of infection in a mouse strain resistant to L. (L.) amazonensis (C3H/HePas). in contrast, the susceptible strain (BALB/c) displayed a predominance of macrophages harboring a high number of amastigotes and very few neutrophils. These findings led us to investigate the interaction of inflammatory neutrophils with L. (L.) amazonensis-infected macrophages in vitro.Methodology/Principal Findings: Mouse peritoneal macrophages infected with L. (L.) amazonensis were co-cultured with inflammatory neutrophils, and after four days, the infection was quantified microscopically. Data are representative of three experiments with similar results. the main findings were 1) intracellular parasites were efficiently destroyed in the co-cultures; 2) the leishmanicidal effect was similar when cells were obtained from mouse strains resistant (C3H/HePas) or susceptible (BALB/c) to L. (L.) amazonensis; 3) parasite destruction did not require contact between infected macrophages and neutrophils; 4) tumor necrosis factor alpha (TNF-alpha), neutrophil elastase and platelet activating factor (PAF) were involved with the leishmanicidal activity, and 5) destruction of the parasites did not depend on generation of oxygen or nitrogen radicals, indicating that parasite clearance did not involve the classical pathway of macrophage activation by TNF-alpha, as reported for other Leishmania species.Conclusions/Significance: the present results provide evidence that neutrophils in concert with macrophages play a previously unrecognized leishmanicidal effect on L. (L.) amazonensis. We believe these findings may help to understand the mechanisms involved in innate immunity in cutaneous infection by this Leishmania species.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo, Dept Microbiol Imunol & Parasitol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Microbiol Imunol & Parasitol, São Paulo, BrazilWeb of Scienc
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