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101.
Holetz FB Ueda-Nakamura T Dias Filho BP Mello JC Morgado-Díaz JA Toledo CE Nakamura CV 《Memórias do Instituto Oswaldo Cruz》2005,100(4):397-401
We report the effect of Stryphnodendron adstringens on the trypanosomatid Herpetomonas samuelpessoai. The parasites were grown at 28 degrees C in a chemically defined medium containing crude extract and fractions at concentrations from 100 to 5000 microg/ml obtained from S. adstringens. Concentrations of 500, 1000, 2500, and 5000 microg/ml both crude extract and semi-purified fraction progressively inhibited the protozoans' growth. At a concentration of 100 microg/ml, crude extract or a semi-purified (F3) fraction did not affect the growth of the protozoans. The F3-9 - F3-12 sub-fractions, at a concentration of 1000 microg/ml, also showed increased inhibitory activity on H. samuelpessoai. The IC50 of the crude extract and the F3 fraction were 538 and 634 microg/ml, respectively. Ultrastructural and enzymatic alterations in the trypanosomatids were also evaluated. H. samuelpessoai cultivated in the presence of IC50 crude extract showed considerable ultrastructural alterations, such as marked mitochondrial swelling with a large number of cristae and evident Golgi complex vesiculation, as observed by transmission electron microscopy. Cells exposed to 538 microg/ml of crude extract at 28 degrees C for 72 h, showed decreased activity of the enzyme succinate cytochrome c reductase, a typical mitochondrion marker, as compared to untreated cells. 相似文献
102.
Nascimento EM Gehrke Fde S Maldonado RA Colombo S Silva LJ Schumaker TT 《Memórias do Instituto Oswaldo Cruz》2005,100(3):277-279
Brazilian spotted fever (BSF) cases have been increasing in the state of S?o Paulo but no genomic information about local rickettsia isolated from humans has been well documented. We recovered spotted-fever group rickettsiae from a sample of patient blood cultured in Vero cells using the shell vial technique. Rickettsial DNA fragments (gltA, ompA, and, ompB genes) were detected, and analysis of the ompB gene base sequences showed identity with the Rickettsia rickettsii ompB sequence available in the GenBank. 相似文献
103.
An N-acetylglucosaminidase produced by Streptomyces cerradoensis was partially purified giving, by SDS-PAGE analysis, two main protein bands with Mr of 58.9 and 56.4 kDa. The Km and Vmax values for the enzyme using p-nitrophenyl-β-N-acetylglucosaminide as substrate were of 0.13 mM and 1.95 U mg−1 protein, respectively. The enzyme was optimally activity at pH 5.5 and at 50 °C when assayed over 10 min. Enzyme activity
was strongly inhibited by Cu2+ and Hg2+ at 10 mM, and was specific to substrates containing acetamide groups such as p-nitrophenyl-β-N-acetylglucosaminide and p-nitrophenyl-β-D-N,N′-diacetylchitobiose. 相似文献
104.
Aguiar LM Macedo DS de Freitas RM de Albuquerque Oliveira A Vasconcelos SM de Sousa FC de Barros Viana GS 《Life sciences》2005,76(19):2193-2202
The present work studied in vivo neuroprotective effects of n-acetylserotonin (NAS), the immediate precursor of melatonin, on the dopaminergic system, in rats lesioned with the unilateral intrastriatal injection of the neurotoxin 6-hydroxydopamine (6-OHDA). Two weeks after the lesion, the dopamine receptor agonist, apomorphine, produced rotational asymmetry, and the NAS treatment significantly reduced the motor deficit following the apomorphine challenge. The apomorphine-induced rotational behavior was blocked by 84, 86 and 53% after NAS, at doses of 2, 5 and 10 mg/kg, i.p., respectively. The injection of 6-OHDA significantly decreased DA, DOPAC and HVA levels in the rat striatum. In contrast, the NAS (2, 5 and 10 mg/kg, i.p., daily for 7 days) treatment partially reversed the decreases caused by 6-OHDA, and the neurotransmitter levels were brought to approximately 50% of that observed in the contralateral sides. NAS was more efficient at the smaller doses. NAS (5 mg/kg) produced an up-regulation of D1 (37%) and D2 (37%) receptors associated with a decrease in Kd values. 相似文献
105.
Mendes de Freitas R Aguiar LM Vasconcelos SM Sousa FC Viana GS Fonteles MM 《Life sciences》2005,78(3):253-258
The present study was undertaken in order to investigate the muscarinic (M(1)), dopaminergic (D(1) and D(2)) and serotonergic (5-HT(2)) receptors densities in hippocampus and striatum of Wistar rats after status epilepticus (SE) induced by pilocarpine. The control group was treated with 0.9% saline. An other group of rats received pilocarpine (400 mg/kg, s.c.) and both groups were sacrificed 1 h after treatment. The results have shown that pilocarpine administration and resulting SE produced a downregulation of M(1) receptor in hippocampus (41%) and striatum (51%) and an increase in the dissociation constant (K(d)) values in striatum (42%) alone. In both areas the 5-HT(2) receptor density remained unaltered, but a reduction (50%) and an increase (15%) in the K(d) values were detected in striatum and hippocampus, respectively. D(1) and D(2) receptor densities in hippocampus and striatum remained unaltered meanwhile K(d) values for D(1) receptor declined significantly, 33% in hippocampus and 26% in striatum. Similarly, K(d) values for D(2) decreased 55% in hippocampus and 52% in striatum. From the preceding results, it is clear that there is a possible relation between alterations in muscarinic receptor density and others systems studied as well as they suggest that changes in dissociation constant can be responsible for the establishment of pilocarpine-induced SE by altering the affinity of neurotransmitters such as acetylcholine, dopamine and serotonine. 相似文献
106.
Ferreira VS Rêgo IN Pastore F Mandai MM Mendes LS Santos KA Rubim JC Suarez PA 《Bioresource technology》2005,96(5):605-609
A comparative study of rubber sheets obtained using formic, acetic, and smoke acid as coagulants is shown for latex obtained from native Amazonian trees and also from commercial cultivated trees. The evaluation of both processes of coagulation was carried out by spectroscopic and physical-chemical analysis, showing no differences in the rubber sheets obtained. This new method of rubber sheet preparation was introduced into Amazonian rainforest rubber tapper communities, which are actually producing in large scale. The physical-mechanical properties were similar among a large sheets made by different rubber tapper communities using this new method. 相似文献
107.
108.
Guerreiro LT Souza SS Wagner G De Souza EA Mendes PN Campos LM Barros L Pires PF Campos ML Grisard EC Dávila AM 《Omics : a journal of integrative biology》2005,9(1):116-128
A survey of the Trypanosoma vivax genome was carried out by the genome sequence survey (GSS) approach resulting in 1,086 genomic sequences. A total of 455 high-quality GSS sequences were generated, consisting of 331 non-redundant sequences distributed in 264 singlets and 67 clusters in a total of 135.5 Kb of the T. vivax genome. The estimation of the overall G+C content, and the prediction of the presence of ORFs and putative genes were carried out using the Glimmer and Jemboss packages. Analysis of the obtained sequences was carried out by BLAST programs against 12 different databases and also using the Conserved Domain Database, InterProScan, and tRNAscan-SE. Along with the existing 23 T. vivax entries in the GenBank, the 32 putative genes predicted and the 331 non-redundant GSS sequences reported herein represent new potential markers for the development of PCRbased assays for specific diagnosis and typing of Trypanosoma vivax. 相似文献
109.
do C Borges NC Mendes GD Barrientos-Astigarraga RE Galvinas P Oliveira CH De Nucci G 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2005,827(2):165-172
An analytical method based on liquid chromatography with positive ion electrospray ionization (ESI) coupled to tandem mass spectrometry detection (LC-MS/MS) was developed for the determination of Verapamil in human plasma using Metoprolol as the internal standard. The analyte and internal standard were extracted from the plasma samples by liquid-liquid extraction and chromatographed on a C(8) analytical column. The mobile phase consisted of methanol-water (70:30; v/v)+12 mM formic acid. The method had a chromatographic total run time of 3.5 min and was linear within the range 1.00-500 ng/mL. Detection was carried out on a Micromass Quattro Ultima tandem mass spectrometer by multiple reaction monitoring (MRM). The intra-run imprecision was less than 5.1% calculated from the quality control (QC) samples, and 16.3% from the limit of quantification (LOQ). The accuracy determined from QC samples were between 92.9 and 103.1%, and 95.2 and 115.3% from LOQ. Concerning the inter-batch analysis, the imprecision was less than 5.8% and 17.3% from QC samples and LOQ, respectively. The accuracy varied between 98.2 and 100.8% from QC and it was 103.1% from LOQ. The protocol herein described was employed in a bioequivalence study of two tablet formulations of Verapamil. 相似文献
110.
The orb-web spiders are polyphagous animals in which the web plays a very important role in the capture of preys; oily droplets usually cover the capture-web of the spider Nephila clavipes and seem to be of great importance for prey capture. The knowledge of the chemical composition of these droplets is necessary to understand the function of this adhesive material in web mechanics and prey capture. A novel subclass of spider toxins, tetrahydro-beta-carboline, was identified among the weaponry of compounds present inside of oily droplets. This type of alkaloid is not common among the natural compounds of spider toxins. Apparently, when the prey arthropods get caught by the spider web, their bodies are covered with many adhesive oily droplets, which disrupt delivering the tetrahydro-beta-carboline to the direct contact with the prey integument. Toxicity assays demonstrated a potent lethal effect of the alkaloid toxin to the spider preys; topical applications of the tetrahydro-beta-carboline at first caused clear signs of neurotoxicity, followed by the death of preys. The structure of the major component, a tetrahydro-beta-carboline, among the alkaloid toxins was elucidated by means of UV spectrophotometry, ESI mass spectrometry, 1H-NMR spectroscopy, and high-resolution mass spectrometry. The structure of the natural toxin was determined as 1-(2-guanidinoethyl)-1,2,3,4-tetrahydro-6-hydroxymethyl)-beta-carboline; the investigation of the pharmacological properties and neurotoxic actions of this compound may be used in the future as reference for the development of new drugs to be applied at level of pest control in agriculture. 相似文献