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951.
de Sousa AA Reis R Bento-Torres J Trévia N Lins NA Passos A Santos Z Diniz JA Vasconcelos PF Cunningham C Perry VH Diniz CW 《PloS one》2011,6(1):e15597
An enriched environment has previously been described as enhancing natural killer cell activity of recognizing and killing virally infected cells. However, the effects of environmental enrichment on behavioral changes in relation to virus clearance and the neuropathology of encephalitis have not been studied in detail. We tested the hypothesis that environmental enrichment leads to less CNS neuroinvasion and/or more rapid viral clearance in association with T cells without neuronal damage. Stereology-based estimates of activated microglia perineuronal nets and neurons in CA3 were correlated with behavioral changes in the Piry rhabdovirus model of encephalitis in the albino Swiss mouse. Two-month-old female mice maintained in impoverished (IE) or enriched environments (EE) for 3 months were behaviorally tested. After the tests, an equal volume of Piry virus (IEPy, EEPy)-infected or normal brain homogenates were nasally instilled. Eight days post-instillation (dpi), when behavioral changes became apparent, brains were fixed and processed to detect viral antigens, activated microglia, perineuronal nets, and T lymphocytes by immuno- or histochemical reactions. At 20 or 40 dpi, the remaining animals were behaviorally tested and processed for the same markers. In IEPy mice, burrowing activity decreased and recovered earlier (8-10 dpi) than open field (20-40 dpi) but remained unaltered in the EEPy group. EEPy mice presented higher T-cell infiltration, less CNS cell infection by the virus and/or faster virus clearance, less microgliosis, and less damage to the extracellular matrix than IEPy. In both EEPy and IEPy animals, CA3 neuronal number remained unaltered. The results suggest that an enriched environment promotes a more effective immune response to clear CNS virus and not at the cost of CNS damage. 相似文献
952.
Simões RR Aires-de-Sousa M Conceição T Antunes F da Costa PM de Lencastre H 《PloS one》2011,6(3):e17630
Background
The nosocomial prevalence of methicillin resistant Staphylococcus aureus (MRSA) in Portugal remains one of the highest in Europe and is currently around 50%. Transmission of S. aureus, including MRSA, occurs principally by direct human-to-human skin contact. However, S. aureus can survive for long periods on inanimate objects, which may represent an important reservoir for dissemination as well.Methodology/Principal Findings
Between May 2009 and February 2010, handrails of 85 public urban buses circulating in Oporto, Portugal, were screened for the occurrence of MRSA. Twenty-two (26%) buses showed MRSA contamination. The molecular characterization of a total of 55 MRSA, by pulsed-field gel electrophoresis (PFGE), staphylococcal cassette chromosome (SCC) mec typing, spa typing, and multilocus sequence typing (MLST), clustered the isolates into three clonal types. However, the overwhelming majority (n = 50; 91%) of the isolates belonged to a single clone (PFGE A, spa types t747, t032, t025 or t020, ST22, SCCmec type IVh) that exhibits the characteristics of the pandemic EMRSA-15, currently the major lineage circulating in Portuguese hospitals, namely in the Oporto region. Two additional clones were found but in much lower numbers: (i) PFGE B, ST5, spa type t002, SCCmec IVa (n = 3), and (ii) PFGE C, spa type t008, ST8, SCCmec IVa (n = 2). None of the 55 isolates was PVL positive.Conclusions/Significance
Public buses in Oporto seem to be an important reservoir of MRSA of nosocomial origin, providing evidence that the major hospital-associated MRSA clone in Portugal is escaping from the primary ecological niche of hospitals to the community environment. Infection control measures are urgently warranted to limit the spread of EMRSA-15 to the general population and future studies are required to assess the eventual increase of MRSA in the Portuguese community, which so far remains low. 相似文献953.
Alyne Mara Rodrigues de Carvalho Nayrton Flávio Moura Rocha Leonardo Freire Vasconcelos Emiliano Ricardo Vasconcelos Rios Marília Leite Dias Maria Izabel Gomes Silva Marta Maria de França Fonteles José Maria Barbosa Filho Stanley Juan Chavez Gutierrez Francisca Cléa Florenço de Sousa 《Chemico-biological interactions》2013
Riparin II (RipII), an alkamide isolated from the green fruit of Aniba riparia, was tested in the various animal models of inflammation to investigate its anti-inflammatory activity. Male Wistar rats (180–240 g) were treated with RipII by gavage at doses 25 or 50 mg/kg, before initiating the inflammatory responses. The tests used were paw edema induced by carrageenan, dextran, histamine or serotonin; peritonitis induced by carrageenan and fMLP, as well as the measurement of MPO activity, TNF-α and Il-1β amount in the peritoneal fluid. In the animal models of carrageenan and dextran-induced paw edema, the animals treated with RipII showed lower edema than those of the control group. Treatment with RipII also reduced the paw edema induced by histamine but not serotonin. In the carrageenan-induced peritonitis model, treatment with RipII reduced leukocyte migration, the MPO activity and the amount of TNF-α and IL-1β in the peritoneal fluid. In summary, these results indicate that RipII has an anti-inflammatory activity in chemical models of acute inflammation. RipII might be directly or indirectly inhibiting the activity, production or release of pro-inflammatory mediators involved in the generation of the pain associated with inflammation. 相似文献
954.
Iara F. Lopes Carolina I. Miño Cristiano D. Rocha Dalci M. M. Oliveira Silvia N. Del Lama 《Genetica》2013,141(4-6):195-203
The present study inferred the genetic mating system in a natural breeding population of the Jabiru Stork (Jabiru mycteria), a Neotropical wading bird considered endangered in part of its distribution range. Based on data from eight microsatellite loci, maximum-likelihood kinship reconstruction techniques, parentage assignment analyses and effective population size (Ne) estimates were applied to samples collected in the Brazilian Pantanal wetland (N = 45 nestlings from 20 nests; N = 17 shed adult feathers from 11 nests). The relationship diagnosis was determined for most of the complete clutches (86.66 %): 92.31 % were full siblings and 7.69 % were half siblings. Shed feathers collected from the nests matched the genetic parents of the offspring in 80 % of cases. Feathers collected from the ground below the nests were compatible with the putative parents in 41.67 % of cases. A mean Ne of 35 reproductive individuals was inferred, corresponding to an Ne/Nc ratio of 0.09, which is similar to the ratio found in populations of a number of different wild animals. The higher proportion of full siblings identified in the broods suggests that genetic monogamy is the prevalent mating system in the Jabiru Stork, while the detection of half siblings suggests some degree of extra-pair paternity. The present findings are in agreement with previous ecological observations of social monogamy in this species, despite the isolated evidence of extra-pair copulation events. This study also demonstrates the usefulness of a noninvasive approach to sampling adults and performing parentage and relatedness analyses in an elusive, threatened species. 相似文献
955.
Aline José Maia Kátia Regina Freitas Schwan-Estrada Renato Vasconcelos Botelho Virlene do Amaral Jardinetti Cacilda Márcia Duarte Rios Faria Aline Fontana Batista Willian Ferreira da Costa 《Acta Physiologiae Plantarum》2013,35(9):2727-2735
The lack of more sustainable options for inducing bud break in grapevines in mild winter regions is a limiting factor for local viticulture due to restrictions on the use of agrochemicals. Within this context, an experiment was conducted to evaluate the effects of a hydrolate obtained from Gallesia integrifolia (a native Brazilian tree) on the bud break of grapevines cv. Ives. The experiment was conducted in a vineyard located in Marialva, Paraná, Brazil, over two consecutive crop cycles: 2011 (September/December) and 2012 (February/May). The treatments consisted of the following doses of Gallesia hydrolate (GH): 0, 100, 150, 200, and 250 mL L?1, as well as 30 mL L?1 of garlic extract and 20 mL L?1 of hydrogen cyanamide, which were used as positive controls. The following variables were evaluated: sprouting percentage per plant, number of clusters per plant, cluster mass, yield (t ha?1), catalase and peroxidase activities. The GH treatments improved bud break in cv. Ives during both crop cycles, demonstrating quadratic effects relative to the applied doses. The same effect was verified for the number of clusters and for the yield. Twenty-four hours after the treatments, a quadratic effect for peroxidase and catalase activity was verified relative to the GH doses applied. For peroxidase activity, the treatment at 200 mL L?1 GH resulted in a 57 % reduction relative to the control. The most abundant component found in GH was dimethyl disulfide. Based on these results, GH at 150 mL L?1 could be a promising alternative to the currently used methods for promoting bud break in cv. Ives, representing a cheaper and more environmentally friendly option for viticulture. 相似文献
956.
Marcio Roberto Silva Adalgiza da Silva Rocha Ronaldo Rodrigues da Costa Andrea Padilha de Alencar Vania Maria de Oliveira Ant?nio Augusto Fonseca Júnior Mariana Lázaro Sales Marina de Azevedo Issa Paulo Martins Soares Filho Omara Tereza Vianello Pereira Eduardo Calazans dos Santos Rejane Silva Mendes ?ngela Maria de Jesus Ferreira Pedro Moacyr Pinto Coelho Mota Philip Noel Suffys Mark Drew Crosland Guimar?es 《Memórias do Instituto Oswaldo Cruz》2013,108(3):321-327
In this cross-sectional study, mycobacteria specimens from 189 tuberculosis (TB) patients living in an urban area in Brazil were characterised from 2008-2010 using phenotypic and molecular speciation methods (pncA gene and oxyR pseudogene analysis). Of these samples, 174 isolates simultaneously grew on Löwenstein-Jensen (LJ) and Stonebrink (SB)-containing media and presented phenotypic and molecular profiles of Mycobacterium tuberculosis, whereas 12 had molecular profiles of M. tuberculosis based on the DNA analysis of formalin-fixed paraffin wax-embedded tissue samples (paraffin blocks). One patient produced two sputum isolates, the first of which simultaneously grew on LJ and SB media and presented phenotypic and molecular profiles of M. tuberculosis, and the second of which only grew on SB media and presented phenotypic profiles of Mycobacterium bovis. One patient provided a bronchial lavage isolate, which simultaneously grew on LJ and SB media and presented phenotypic and molecular profiles of M. tuberculosis, but had molecular profiles of M. bovis from paraffin block DNA analysis, and one sample had molecular profiles of M. tuberculosis and M. bovis identified from two distinct paraffin blocks. Moreover, we found a low prevalence (1.6%) of M. bovis among these isolates, which suggests that local health service procedures likely underestimate its real frequency and that it deserves more attention from public health officials. 相似文献
957.
Vanessa Silva-Moraes Flávia Fernanda Bubula Couto Marah Mileib Vasconcelos Neusa Araújo Paulo Marcos Zech Coelho Naftale Katz Rafaella Fortini Queiroz Grenfell 《Memórias do Instituto Oswaldo Cruz》2013,108(5):600-604
Current schistosomiasis control strategies are largely based on chemotherapeutic
agents and a limited number of drugs are available today. Praziquantel (PZQ) is
the only drug currently used in schistosomiasis control programs. Unfortunately,
this drug shows poor efficacy in patients during the earliest infection phases.
The effects of PZQ appear to operate on the voltage-operated Ca2+channels, which
are located on the external Schistosoma mansoni membrane.
Because some Ca2+channels have dihydropyridine drug class (a class that includes
nifedipine) sensitivity, an in vitro analysis using a calcium channel antagonist
(clinically used for cardiovascular hypertension) was performed to determine the
antischistosomal effects of nifedipine on schistosomula and adult worm cultures.
Nifedipine demonstrated antischistosomal activity against schistosomula and
significantly reduced viability at all of the concentrations used alone or in
combination with PZQ. In contrast, PZQ did not show significant efficacy when
used alone. Adult worms were also affected by nifedipine after a 24 h incubation
and exhibited impaired motility, several lesions on the tegument and intense
contractility. These data support the idea of Ca2+channels subunits as drug
targets and favour alternative therapeutic schemes when drug resistance has been
reported. In this paper, strong arguments encouraging drug research are
presented, with a focus on exploring schistosomal Ca2+channels. 相似文献
958.
Luiz Francisco Rocha e Silva Emerson Silva Lima Marne Carvalho de Vasconcellos Ellen Suzany Pereira Aranha David Siqueira Costa Elba Vieira Mustafa Sabrina Kelly Reis de Morais Maria das Gra?as Costa Alecrim Sergio Massayoshi Nunomura Lena Struwe Valter Ferreira de Andrade-Neto Adrian Martin Pohlit 《Memórias do Instituto Oswaldo Cruz》2013,108(4):501-507
Tachia sp. are used as antimalarials in the Amazon Region and
in vivo antimalarial activity of a Tachia sp. has been
previously reported. Tachia grandiflora Maguire and Weaver is
an Amazonian antimalarial plant and herein its cytotoxicity and antimalarial
activity were investigated. Spectral analysis of the tetraoxygenated xanthone
decussatin and the iridoid aglyone amplexine isolated, respectively, from the
chloroform fractions of root methanol and leaf ethanol extracts was performed.
In vitro inhibition of the growth of Plasmodium falciparum
Welch was evaluated using optical microscopy on blood smears. Crude extracts of
leaves and roots were inactive in vitro. However, chloroform fractions of the
root and leaf extracts [half-maximal inhibitory concentration (IC50) = 10.5 and
35.8 µg/mL, respectively] and amplexine (IC50= 7.1 µg/mL) were active in vitro.
Extracts and fractions were not toxic to type MRC-5 human fibroblasts (IC50>
50 µg/mL). Water extracts of the roots of T. grandiflora
administered by mouth were the most active extracts in the Peters 4-day
suppression test in Plasmodium berghei-infected mice. At 500
mg/kg/day, these extracts exhibited 45-59% inhibition five to seven days after
infection. T. grandiflora infusions, fractions and isolated
substance have potential as antimalarials. 相似文献
959.
C. Almeida J. M. Sousa R. Rocha L. Cerqueira S. Fanning N. F. Azevedo M. J. Vieira 《Applied and environmental microbiology》2013,79(20):6293-6300
Despite the emergence of non-O157 Shiga toxin-producing Escherichia coli (STEC) infections, E. coli serotype O157 is still the most commonly identified STEC in the world. It causes high morbidity and mortality and has been responsible for a number of outbreaks in many parts of the world. Various methods have been developed to detect this particular serotype, but standard bacteriological methods remain the gold standard. Here, we propose a new peptide nucleic acid fluorescence in situ hybridization (PNA-FISH) method for the rapid detection of E. coli O157. Testing on 54 representative strains showed that the PNA probe is highly sensitive and specific to E. coli O157. The method then was optimized for detection in food samples. Ground beef and unpasteurized milk samples were artificially contaminated with E. coli O157 concentrations ranging from 1 × 10−2 to 1 × 102 CFU per 25 g or ml of food. Samples were then preenriched and analyzed by both the traditional bacteriological method (ISO 16654:2001) and PNA-FISH. The PNA-FISH method performed well in both types of food matrices with a detection limit of 1 CFU/25 g or ml of food samples. Tests on 60 food samples have shown a specificity value of 100% (95% confidence interval [CI], 82.83 to 100), a sensitivity of 97.22% (95% CI, 83.79 to 99.85%), and an accuracy of 98.33% (CI 95%, 83.41 to 99.91%). Results indicate that PNA-FISH performed as well as the traditional culture methods and can reduce the diagnosis time to 1 day. 相似文献
960.
Angélica de Souza Gouveia Thalita Suelen Avelar Monteiro Samuel Vasconcelos Valadares Bruna Leite Sufiate Leandro Grassi de Freitas Humberto Josué de Oliveira Ramos 《Geomicrobiology journal》2013,30(8):747-751
AbstractThe fungus Pochonia chlamydosporia (Pc) has been increasingly used to control plant-parasitic nematodes. This fungus also increases the uptake of nutrients by plants. However, the mechanisms by which Pc modifies the soil nutrient supply and, or the capacity of plants to acquire nutrients are not fully understood. In this research we investigated possible mechanisms that explain how Pc increases phosphorus uptake by plants. We tested the hypothesis that Pc produces phosphatases, which are enzymes that promote depolymerization of organic phosphate compounds. We further investigated if the known effect of Pc on inorganic phosphate (IP) solubilization could be credited to the release of organic acids and, if so, which organic acids are secreted by the fungus. Three isolates of the fungus (Pc-10, Pc-40, and Pc-46) were used in the study. We found that Pc can produce acid (Pc-10 = 0.0209 U/ml, Pc-40 = 0.0282 U/ml, Pc-46 = 0.0094 U/ml) and alkaline phosphatases (Pc-10 = 0.0490 U/ml, Pc-40 = 0.0000, Pc-46 = 0.0306 U/ml). All isolates were able to solubilize IP. The isolate Pc-10 solubilized higher amounts of phosphate (47.5 mg/l) compared to Pc-40 (37.9 mg/l) and Pc-46 (36.6 mg/l). We also identified three organic acids (acetic, citric, and propionic acid) produced by Pc-10. To our knowledge, this is the first report of Pc producing phosphatases and organic acids. 相似文献