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981.
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
982.
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
983.
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
984.
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
985.
Joana Rocha Magali Audry Gaelle Pesce Valérie Chazalet Maryse A. Block Eric Maréchal Christelle Breton 《Biochimie》2013
Monogalactosyldiacylglycerol, the major lipid of plants and algal plastids, is synthesized by MGDG synthases (MGD). MGDs belong to the large glycosyltransferase family. They catalyze the transfer of a galactose residue from the donor UDP-Gal to a 1,2-sn-diacylglycerol acceptor. MGDs are monotopic proteins localized in the plastid envelope and, as such, they are difficult to purify. This study re-examined previous purification procedures and aimed to set up a standard protocol for expression and purification of recombinant MGD1, addressing problems frequently encountered with the purification of glycosyltransferases, particularly protein aggregation, and enabling crystallization for structural studies. Briefly, His-tagged versions of MGD1 were expressed in Escherichia coli and purified by a two-step procedure, including immobilized metal affinity chromatography and size-exclusion chromatography. We demonstrated that E. coli is an appropriate host cell to produce a soluble and active form of MGD1. We also investigated the effects of various buffers and additives used during the purification and concentration steps on the biochemical behavior of the enzyme. The protocol we developed typically yields milligram quantities of pure and homogenous protein material and proved suitable for crystallization and biochemical studies. We also revisited the conditions for activity tests and effects of known positive effectors of MGD1 such as phosphatidic acid and phosphatidylglycerol. 相似文献
986.
Dayse Maria Vasconcelos de Deus Paulo Roberto Eleutério de Souza Maria Tereza Cartaxo Muniz 《Molecular biology reports》2013,40(2):1609-1613
Patients with acute lymphoblastic leukemia presenting the immunophenotypic marker CD10+ (calla), usually has treatment profile good. The FLT3 molecular marker is listed as a prognostic factor, an important leukaemogenic marker in acute leukemias, also the polymorphism (G1082A) of the IL10 interleukin can to present pleiotropic effects in many diseases and could is associated to development of ALL. However, the FLT3 expression is variability among patients with calla-ALL. The aim of this study was to determine the FLT3 expression, to associate with the genotypes and allelic of G1082A (IL10) in 50 patients with calla-ALL and assess the overall survival at 98 months follow-up. The expression was assessed by quantitative real time PCR (RT-PCR), the G1082A polymorphism was identified by allele-specific PCR and for immunophenotypic classification was used specific markers of B lineage-calla. We observed that patients who died showed higher FLT3 expression (p = 0.005), worse survival (p = 0.0137) and the IL10G allele may favor the survival, because the IL10 GG and IL10 GA genotypes showed a low FLT3 expression (p < 0.05). 相似文献
987.
Kamila Soares Lopes Emiliano Ricardo Vasconcelos Rios Camila Nayane de Carvalho Lima Maria Isabel Linhares Alba Fabíola Costa Torres Alexandre Havt Yves Patric Quinet Marta Maria de França Fonteles Alice Maria Costa Martins 《Neurochemistry international》2013
Arthropod venoms are potential sources of neuroactive substances, providing new tools for the design of drugs. The aim of this study was to evaluate the effects of Dinoponera quadriceps venom (DqV) on seizure models in mice induced by pentylenetetrazole (PTZ), pilocarpine, and strychnine. In the PTZ model, intraperitoneal treatment with DqV (0.5 mg/kg) increased the time until the first seizure and the percentage of survival (155.4 ± 27.7 s/12.5%, p < 0.05) compared to the control group (79.75 ± 3.97 s/0%), whereas endovenous treatment (0.1 and 0.5 mg/kg) decreased the time until the first seizure (0.1 mg/kg: 77.83 ± 5.3 s versus 101.0 ± 3.3 s in the control group; 0.5 mg/kg: 74.43 ± 3.9 s versus 101.0 ± 3.3 s for the control group, p < 0.05). We did not observe significant changes in the pilocarpine- and strychnine-induced seizure models. In assays that measured oxidative parameters in the PTZ model, intraperitoneal treatment with DqV (0.5 and 2.0 mg/kg) only decreased the levels of MDA and nitrite in the cortex. However, endovenous treatment with DqV (0.1 and 0.5 mg/kg) increased the levels of MDA in the cortex and hippocampus and at a dose of 0.5 mg/kg in the striatum. Moreover, increased in nitrite content was observed in all three of the brain regions analyzed. Taken together, the D. quadriceps venom caused both neuroprotective and neurotoxic effects in a PTZ-induced seizure model, and this effect was dependent on the route of administration used. 相似文献
988.
Jade de Oliveira Eduardo Luiz Gasnhar Moreira Gianni Mancini Mariana Appel Hort Alexandra Latini Rosa Maria Ribeiro-do-Valle Marcelo Farina João Batista Teixeira da Rocha Andreza Fabro de Bem 《Neurochemical research》2013,38(10):2028-2036
Recent studies have indicated a causal link between high dietary cholesterol intake and brain oxidative stress. In particular, we have previously shown a positive correlation between elevated plasma cholesterol levels, cortico-cerebral oxidative stress and mitochondrial dysfunction in low density lipoprotein receptor knockout (LDLr?/?) mice, a mouse model of familial hypercholesterolemia. Here we show that the organoselenium compound diphenyl diselenide (PhSe)2 (1 mg/kg; o.g., once a day for 30 days) significantly blunted the cortico-cerebral oxidative stress and mitochondrial dysfunction induced by a hypercholesterolemic diet in LDLr?/? mice. (PhSe)2 effectively prevented the inhibition of complex I and II activities, significantly increased the reduced glutathione (GSH) content and reduced lipoperoxidation in the cerebral cortex of hypercholesterolemic LDLr?/? mice. Overall, (PhSe)2 may be a promising molecule to protect against hypercholesterolemia-induced effects on the central nervous system, in addition to its already demonstrated antiatherogenic effects. 相似文献
989.
990.
Tavani Rocha Camargo Milena Regina Wolf Fernando L. Mantelatto Christopher Tudge Fernando José Zara 《Acta zoologica》2020,101(1):89-100
The families Aethridae and Calappidae were originally considered as part of the same family; however, their morphology and molecular biology separate them into two families. In this context, we describe the ultrastructure of spermatozoa of species of the Calappidae, Aethridae and Menippidae to elucidate the relationships among taxa. The vasa deferentia were submitted to routine protocols for transmission electron microscopy. Our results indicate that the morphology of the spermatozoa of Hepatus pudibundussupports its exclusion from the Superfamily Calappoidea due to the presence of the apical striated layer. The spermatozoa of Menippe nodifrons is very similar to H. pudibundus and corroborates the recent phylogenetic analysis using sequence data of nuclear genes. Moreover, our results evidence two morphological patterns of spermatozoa within Calappidae. Calappa ocellata and C. cinerea show spermatozoa with a wide acrosome vesicle, a thick operculum shaped as a shallow “W” and a large thickened ring. Calappa gallusand C. hepatica show spermatozoa with a longer acrosome vesicle, a pointed operculum and a slender thickened ring. Our ultrastructure results conform with previous molecular proposal and show that spermatozoa ultrastructure can be an effective tool to adjust phylogenetic relationship when used in association with molecular data. 相似文献