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941.
Mariana Concei??o Souza Tatiana Almeida Padua Natalia Domingos Torres Maria Fernanda de Souza Costa Victor Facchinetti Claudia Regina Brand?o Gomes Marcus Vinícius Nora Souza Maria das Gra?as Henriques 《Memórias do Instituto Oswaldo Cruz》2015,110(4):560-565
A rapid decrease in parasitaemia remains the major goal for new antimalarial drugs
and thus, in vivo models must provide precise results concerning parasitaemia
modulation. Hydroxyethylamine comprise an important group of alkanolamine compounds
that exhibit pharmacological properties as proteases inhibitors that has already been
proposed as a new class of antimalarial drugs. Herein, it was tested the antimalarial
property of new nine different hydroxyethylamine derivatives using the green
fluorescent protein (GFP)-expressing Plasmodium berghei strain. By
comparing flow cytometry and microscopic analysis to evaluate parasitaemia
recrudescence, it was observed that flow cytometry was a more sensitive methodology.
The nine hydroxyethylamine derivatives were obtained by inserting one of the
following radical in the para position: H, 4Cl, 4-Br, 4-F, 4-CH3,
4-OCH3, 4-NO2, 4-NH2 and 3-Br. The antimalarial test showed that the compound that
received the methyl group (4-CH3) inhibited 70% of parasite growth. Our results
suggest that GFP-transfected P. berghei is a useful tool to study the recrudescence
of novel antimalarial drugs through parasitaemia examination by flow cytometry.
Furthermore, it was demonstrated that the insertion of a methyl group at the
para position of the sulfonamide ring appears to be critical for
the antimalarial activity of this class of compounds. 相似文献
942.
Liliane Maria Vidal Siqueira Luciana Inácia Gomes Edward Oliveira Eduardo Ribeiro de Oliveira áureo Almeida de Oliveira Martin Johannes Enk Nídia Figueiredo Carneiro Ana Rabello Paulo Marcos Zech Coelho 《Memórias do Instituto Oswaldo Cruz》2015,110(2):209-214
This study evaluated parasitological and molecular techniques for the diagnosis and
assessment of cure of schistosomiasis mansoni. A population-based study was performed
in 201 inhabitants from a low transmission locality named Pedra Preta, municipality
of Montes Claros, state of Minas Gerais, Brazil. Four stool samples were analysed
using two techniques, the Kato-Katz® (KK) technique (18 slides) and the
TF-Test®, to establish the infection rate. The positivity rate of 18 KK
slides of four stool samples was 28.9% (58/201) and the combined parasitological
techniques (KK+TF-Test®) produced a 35.8% positivity rate (72/201).
Furthermore, a polymerase chain reaction (PCR)-ELISA assay produced a positivity rate
of 23.4% (47/201) using the first sample. All 72 patients with positive
parasitological exams were treated with a single dose of Praziquantel® and
these patients were followed-up 30, 90 and 180 days after treatment to establish the
cure rate. Cure rates obtained by the analysis of 12 KK slides were 100%, 100% and
98.4% at 30, 90 and 180 days after treatment, respectively. PCR-ELISA revealed cure
rates of 98.5%, 95.5% and 96.5%, respectively. The diagnostic and assessment of cure
for schistosomiasis may require an increased number of KK slides or a test with
higher sensitivity, such as PCR-ELISA, in situations of very low parasite load, such
as after therapeutic interventions. 相似文献
943.
Achla Gupta Ivone Gomes Jonathan Wardman Lakshmi A. Devi 《The Journal of biological chemistry》2014,289(28):19613-19626
Most neuroendocrine peptides are generated in the secretory compartment by proteolysis of the precursors at classical cleavage sites consisting of basic residues by well studied endopeptidases belonging to the subtilisin superfamily. In contrast, a subset of bioactive peptides is generated by processing at non-classical cleavage sites that do not contain basic residues. Neither the peptidases responsible for non-classical cleavages nor the compartment involved in such processing has been well established. Members of the endothelin-converting enzyme (ECE) family are considered good candidate enzymes because they exhibit functional properties that are consistent with such a role. In this study we have explored a role for ECE2 in endocytic processing of δ opioid peptides and its effect on modulating δ opioid receptor function by using selective inhibitors of ECE2 that we had identified previously by homology modeling and virtual screening of a library of small molecules. We found that agonist treatment led to intracellular co-localization of ECE2 with δ opioid receptors. Furthermore, selective inhibitors of ECE2 and reagents that increase the pH of the acidic compartment impaired receptor recycling by protecting the endocytosed peptide from degradation. This, in turn, led to a substantial decrease in surface receptor signaling. Finally, we showed that treatment of primary neurons with the ECE2 inhibitor during recycling led to increased intracellular co-localization of the receptors and ECE2, which in turn led to decreased receptor recycling and signaling by the surface receptors. Together, these results support a role for differential modulation of opioid receptor signaling by post-endocytic processing of peptide agonists by ECE2. 相似文献
944.
Ricardo Guerra Peixe Marcela Santana Bastos Boechat Alba Lucinia Peixoto Rangel Rh?nia Fran?a Gomes Rosa Maria Luiza Petzl-Erler Lilian MG Bahia-Oliveira 《Memórias do Instituto Oswaldo Cruz》2014,109(1):99-107
The association of single nucleotide polymorphisms (SNPs) in the interferon (IFN)-γ
gene ( IFNG ) with different types of retinal scar lesions
presumably caused by toxoplasmosis were investigated in a cross-sectional
population-based genetic study. Ten SNPs were investigated and after Bonferroni
correction, only the associations between SNPs rs2069718 and
rs3181035 with retinal/retinochoroidal scar lesions type A (most
severe scar lesions) and C (least severe scar lesions), respectively, remained
significant. The associations of two different IFNG SNPs with two
different types of retinal lesions attributable to toxoplasmosis support the
hypothesis that different inflammatory mechanisms underlie the development of these
lesions. The in vitro analysis of IFN-γ secretion by peripheral blood mononuclear
cells stimulated with Toxoplasma gondii antigens was also
investigated. The association between SNP rs2069718 and type A scar
lesions revealed that differential IFN-γ levels are correlated with distinct
genotypes. However, no correlation was observed with IFN-γ secretion levels and the
SNP rs3181035 , which was significantly associated with type C scar
lesions. Our findings strongly suggest that immunogenetic studies of individuals with
congenital or postnatally acquired infection are needed to better understand the role
of IFN-γ and its polymorphisms in the pathogenesis of ocular toxoplasmosis. 相似文献
945.
Sérgio Ricardo Fernandes Araújo Sarra Elisabeth Jamieson Kathryn Margaret Dupnik Glória Regina Monteiro Maurício Lisboa Nobre Márcia Sousa Dias Pedro Bezerra Trindade Neto Maria do Carmo Palmeira Queiroz Carlos Eduardo Maia Gomes Jenefer Mary Blackwell Selma Maria Bezerra Jeronimo 《Memórias do Instituto Oswaldo Cruz》2014,109(2):182-188
Leprosy remains prevalent in Brazil. ErbB2 is a receptor for leprosy bacilli entering
Schwann cells, which mediates Mycobacterium leprae-induced
demyelination and the ERBB2 gene lies within a leprosy
susceptibility locus on chromosome 17q11-q21. To determine whether
polymorphisms at the ERBB2 locus contribute to this linkage peak,
three haplotype tagging single nucleotide polymorphisms (tag-SNPs) (rs2517956,
rs2952156, rs1058808) were genotyped in 72 families (208 cases; 372 individuals) from
the state of Pará (PA). All three tag-SNPs were associated with leprosy per se [best
SNP rs2517959 odds ratio (OR) = 2.22; 95% confidence interval (CI) 1.37-3.59; p =
0.001]. Lepromatous (LL) (OR = 3.25; 95% CI 1.37-7.70; p = 0.007) and tuberculoid
(TT) (OR = 1.79; 95% CI 1.04-3.05; p = 0.034) leprosy both contributed to the
association, which is consistent with the previous linkage to chromosome 17q11-q21 in
the population from PA and supports the functional role of ErbB2 in disease
pathogenesis. To attempt to replicate these findings, six SNPs (rs2517955, rs2517956,
rs1810132, rs2952156, rs1801200, rs1058808) were genotyped in a population-based
sample of 570 leprosy cases and 370 controls from the state of Rio Grande do Norte
(RN) and the results were analysed using logistic regression analysis. However, none
of the associations were replicated in the RN sample, whether analysed for leprosy
per se, LL leprosy, TT leprosy, erythema nodosum leprosum or reversal reaction
conditions. The role of polymorphisms at ERBB2 in controlling
susceptibility to leprosy in Brazil therefore remains unclear. 相似文献
946.
Lise Musset Stéphane Pelleau Romain Girod Vanessa Ardillon Luisiane Carvalho Isabelle Dusfour Margarete SM Gomes Félix Djossou Eric Legrand 《Memórias do Instituto Oswaldo Cruz》2014,109(5):525-533
In a climate of growing concern that Plasmodium falciparum may be
developing a drug resistance to artemisinin derivatives in the Guiana Shield, this
review details our current knowledge of malaria and control strategy in one part of
the Shield, French Guiana. Local epidemiology, test-treat-track strategy, the state
of parasite drug resistance and vector control measures are summarised. Current
issues in terms of mobile populations and legislative limitations are also
discussed. 相似文献
947.
Carla R. Taddei Fernanda F. Oliveira Rubens T. D. Duarte Silvia T. Talarico Elizabeth H. Takagi Isabel I. Ramos Carvalho Filumena M. S. Gomes Kátia Brandt Marina B. Martinez 《Microbial ecology》2014,67(3):624-634
The sequence of bacterial events that occurs during the colonization of the gastrointestinal tract may affect the future health of the host. A clear understanding of the colonization process of the human neonatal gut in developing countries is lacking because the few available studies were mostly performed using culture techniques. Using molecular approaches, this study analyzed the fecal microbiota of children of low socioeconomic status in São Paulo, Brazil, during their first year of life. We collected fecal samples of healthy children at 3, 6, and 12 months of life. Total DNA was extracted directly from feces, and the bacteria-specific primers 27F-1492R were used to construct 16S rRNA libraries. Clones were randomly selected and partially sequenced. The main phylogenetic groups identified at 3 months were Streptococcus, unidentified bacteria, and Escherichia. At 6 months, Escherichia remained predominant, while the unidentified bacterial population increased significantly. At 12 months, a more complex composition of fecal microbiota was observed, represented by unidentified bacteria and microorganisms found at low rates at earlier ages. The genus Escherichia remained the most abundant microorganism (34 % relative abundance and 75 % prevalence). Principal component analysis (PCA) revealed changes in the composition of the microbiota at 6 months and an increase of diversity at 12 months of life. Bifidobacterium was identified by quantitative PCR (qPCR) and showed a high incidence in the microbiota at 3 months. The present results corroborate the global observation of inter-individual variability with an early establishment of microbial complexity at the end of the first year of life and highlight the presence of the Escherichia as abundant in microbiota composition of this group of children. 相似文献
948.
Pedro Curto Daniela Lufrano Cátia Pinto Valéria Custódio Ana Catarina Gomes Sebastián A. Trejo Laura Bakás Sandra Vairo-Cavalli Carlos Faro Isaura Sim?es 《Applied and environmental microbiology》2014,80(1):86-96
Typical plant aspartic protease zymogens comprise a characteristic and plant-specific insert (PSI). PSI domains can interact with membranes, and a role as a defensive weapon against pathogens has been proposed. However, the potential of PSIs as antimicrobial agents has not been fully investigated and explored yet due to problems in producing sufficient amounts of these domains in bacteria. Here, we report the development of an expression platform for the production of the PSI domain of cirsin in the generally regarded as safe (GRAS) yeast Kluyveromyces lactis. We successfully generated K. lactis transformants expressing and secreting significant amounts of correctly processed and glycosylated PSI, as well as its nonglycosylated mutant. A purification protocol with protein yields of ∼4.0 mg/liter was established for both wild-type and nonglycosylated PSIs, which represents the highest reported yield for a nontagged PSI domain. Subsequent bioactivity assays targeting phytopathogenic fungi indicated that the PSI of cirsin is produced in a biologically active form in K. lactis and provided clear evidence for its antifungal activity. This yeast expression system thereby emerges as a promising production platform for further exploring the biotechnological potential of these plant saposin-like proteins. 相似文献
949.
ABA application to maize hybrids contrasting for drought tolerance: changes in water parameters and in antioxidant enzyme activity 总被引:1,自引:0,他引:1
Thiago Corrêa de Souza Paulo César Magalhães Evaristo Mauro de Castro Newton Portilho Carneiro Fábio Andrade Padilha Carlos César Gomes Júnior 《Plant Growth Regulation》2014,73(3):205-217
The objective of this study was to evaluate the effects of abscisic acid (ABA) related to the increase of water-stress tolerance in two drought contrasting maize hybrids: DKB 390 (tolerant) and BRS 1030 (sensitive). The characterization of water status (pre-dawn leaf water potential, Ψpd; midday leaf water potential, Ψmd and stem water potential, Ψst) and antioxidant enzyme activity was conducted on greenhouse grown plants. The ABA, hydrogen peroxide (H2O2), and malondialdehyde (MDA) contents were also analyzed. Water deficit was imposed for 10 days at the flowering stage and a dosage of 100 μM ABA was applied to plant canopy. Measurements were taken during 10 days after the water recovery. With 5 days of stress, the tolerant hybrid showed lower MDA content, decrease in the water status, and higher activity of the enzymes superoxide dismutase, catalase, ascorbate peroxidase, as well as guaiacol, glutathione reductase, dehydroascorbate reductase, polyphenol oxidase, and l-phenylalanine ammonia-lyase, as compared to the sensitive hybrid. With 10 days of stress, DKB 390 had a decrease in the activity of enzymes whereas BRS 1030 showed a higher activity. In addition, the latter showed greater amounts of H2O2 and MDA. ABA application led to a higher tolerance only in DKB 390, due to the increase of water status and the enzymatic activity, mainly the catalase. 相似文献
950.
Rafael Pazinato Vanderlei Klauck Andreia Volpato Alexandre A. Tonin Roberto C. Santos Márcia E. de Souza Rodrigo A. Vaucher Renata Raffin Patrícia Gomes Candice C. Felippi Lenita M. Stefani Aleksandro S. Da Silva 《Experimental & applied acarology》2014,63(1):77-83
The aim of this study was to verify the influence of tea tree oil (TTO) (Melaleuca alternifolia) tested in its pure and nanostructured (TTO nanoparticles) forms on the reproduction of female Rhipicephalus microplus. For our purpose, female ticks were collected from naturally infected animals and treated in vitro with TTO (1, 5, and 10 %) and TTO nanoparticles (0.075, 0.375, and 0.75 %). In order to validate the tests, they were performed in triplicate using positive (amitraz) and negative (untreated) controls. It was possible to observe that pure TTO (5 and 10 %) and TTO nanoparticles (0.375 and 0.75 %) showed 100 % reproductive inhibition on female ticks. Additionally, pure TTO (1 %) also showed an acaricide effect (70 %), similarly to the positive control (78.3 %). This is the first study demonstrating the activity of pure TTO and TTO nanoparticles on female ticks. Therefore, based on these results, we were able to show that both forms and all concentrations of M. alternifolia affected tick reproduction by inhibiting egg laying and hatching. We were also able to show that TTO nanoparticles potentiated the inhibitor effect of pure TTO on the reproduction of R. microplus. 相似文献