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41.
Laëtitia Coudray Renata Marcia de Figueiredo Stéphanie Duez Sylvie Cortial 《Journal of enzyme inhibition and medicinal chemistry》2013,28(4):972-985
With the aim of creating new bisubstrate inhibitors of protein farnesyltransferase (FTase), new carboxylic farnesyl pyrophosphate analogues have been designed and synthesized. The original structures are built around three elements: a prenyl moiety, a 1,4-diacid motif and an imidazole ring. All the compounds were evaluated for their ability to inhibit FTase and compared with the corresponding derivatives lacking the imidazole ring, synthesized for that purpose. These new compounds are not bisubstrate inhibitors probably because the imidazole ring is not in the right position to interact with the zinc atom. However these derivatives display FPP competitive inhibition with a good activity in the carboxylic farnesyl pyrophosphate analogues series. 相似文献
42.
E.G. Santos F.G.P. Costa J.H.V. Silva T.D.D. Martins D.F. Figueiredo‐Lima M. Macari C.J.B. Oliveira P.E.N. Givisiez 《Journal of applied microbiology》2013,114(4):1158-1165
Aims
To evaluate mannan oligosaccharide (MOS) and threonine effects on performance, small intestine morphology and Salmonella spp. counts in Salmonella Enteritidis‐challenged birds.Methods and Results
One‐day‐old chicks (1d) were distributed into five treatments: nonchallenged animals fed basal diet (RB‐0), animals fed basal diet and infected with Salmonella Enteritidis (RB‐I), animals fed high level of threonine and infected (HT‐I), birds fed basal diet with MOS and infected (MOS‐I), birds fed high level of threonine and MOS and infected (HT+MOS‐I). Birds were inoculated at 2d with Salmonella Enteritidis, except RB‐0 birds. Chicks fed higher dietary threonine and MOS showed performance similar to RB‐0 and intestinal morphology recovery at 8 dpi. Salmonella counts and the number of Salmonella‐positive animals were lower in HT+MOS‐I compared with other challenged groups.Conclusion
Mannan oligosaccharides and threonine act synergistically, resulting in improved intestinal environment and recovery after Salmonella inoculation.Significance and Impact of the Study
Nutritional approaches may be useful to prevent Salmonella infection in the first week and putative carcass contamination at slaughter. This is the first report on the possible synergistic effect of mannan oligosaccharides and threonine, and further studies should be performed including performance, microbiota evaluation, composition of intestinal mucins and immune assessment. 相似文献43.
44.
Mara Garcia Tavares Nathalia Teixeira Pietrani Maxwell de Castro Durvale Helder Canto Resende Lucio Antonio de Oliveira Campos 《Genetics and molecular biology》2013,36(1):111-117
Melipona quadrifasciata is a stingless bee widely found throughout the Brazilian territory, with two recognized subspecies, M. quadrifasciata anthidioides, that exhibits interrupted metasomal stripes, and M. quadrifasciata quadrifasciata, with continuous metasomal stripes. This study aimed to estimate the genetic variability of these subspecies. For this purpose, 127 colonies from 15 Brazilian localities were analyzed, using nine species-specific microsatellite primers. At these loci, the number of alleles ranged from three to 15 (mean: 7.2), and the observed heterozygosity (Ho) ranged from 0.03–0.21, while the expected heterozygosity (He) ranged from 0.23–0.47. The genetic distances among populations ranged from 0.03–0.45. The FST multilocus value (0.23) indicated that the populations sampled were structured, and the clustering analysis showed the formation of two subgroups and two more distant populations. The first group contained the subspecies M. quadrifasciata quadrifasciata, and the other, the subspecies M. quadrifasciata anthidioides and the two M. quadrifasciata populations with continuous metasomal stripes from northern Minas Gerais. These results confirmed that the yellow metasomal stripes alone are not a good means for correctly identifying the different subspecies of M. quadrifasciata. 相似文献
45.
Carola E. Bunse Sylvia Borchers Pavankumar R. Varanasi Sabine Tischer Constan?a Figueiredo Stephan Immenschuh Ulrich Kalinke Ulrike K?hl Lilia Goudeva Britta Maecker-Kolhoff Arnold Ganser Rainer Blasczyk Eva M. Weissinger Britta Eiz-Vesper 《PloS one》2013,8(12)
Adoptive transfer of antiviral T cells enhances immune reconstitution and decreases infectious complications after stem cell transplantation. Information on number and function of antiviral T cells in stem cell grafts is scarce. We investigated (1) immunomodulatory effects of G-CSF on antiviral T cells, (2) the influence of apheresis, and (3) the optimal time point to collect antiviral cells.CMV-, EBV- and ADV-specific T cells were enumerated in 170 G-CSF-mobilized stem cell and 24 non-mobilized platelet donors using 14 HLA-matched multimers. T-cell function was evaluated by IFN-γ ELISpot and granzyme B secretion. Immunophenotyping was performed by multicolor flow cytometry.G-CSF treatment did not significantly influence frequency of antiviral T cells nor their in vitro expansion rate upon antigen restimulation. However, T-cell function was significantly impaired, as expressed by a mean reduction in secretion of IFN-γ (75% in vivo, 40% in vitro) and granzyme B (32% target-independent, 76% target-dependent) as well as CD107a expression (27%). Clinical follow up data indicate that the first CMV-reactivation in patients and with it the need for T-cell transfer occurs while the donor is still under the influence of G-CSF.To overcome these limitations, T-cell banking before mobilization or recruitment of third party donors might be an option to optimize T-cell production. 相似文献
46.
Jorge Assis Nelson Castilho Coelho Filipe Alberto Myriam Valero Pete Raimondi Dan Reed Ester Alvares Serr?o 《PloS one》2013,8(7)
The genetic consequences of living on the edge of distributional ranges have been
the subject of a largely unresolved debate. Populations occurring along
persistent low latitude ranges (rear-edge) are expected to retain high and
unique genetic diversity. In contrast, currently less favourable environmental
conditions limiting population size at such range-edges may have caused genetic
erosion that prevails over past historical effects, with potential consequences
on reducing future adaptive capacity. The present study provides an empirical
test of whether population declines towards a peripheral range might be
reflected on decreasing diversity and increasing population isolation and
differentiation. We compare population genetic differentiation and diversity
with trends in abundance along a latitudinal gradient towards the peripheral
distribution range of
Saccorhiza
polyschides
, a large brown
seaweed that is the main structural species of kelp forests in SW Europe.
Signatures of recent bottleneck events were also evaluated to determine whether
the recently recorded distributional shifts had a negative influence on
effective population size. Our findings show decreasing population density and
increasing spatial fragmentation and local extinctions towards the southern
edge. Genetic data revealed two well supported groups with a central contact
zone. As predicted, higher differentiation and signs of bottlenecks were found
at the southern edge region. However, a decrease in genetic diversity associated
with this pattern was not verified. Surprisingly, genetic diversity increased
towards the edge despite bottlenecks and much lower densities, suggesting that
extinctions and recolonizations have not strongly reduced diversity or that
diversity might have been even higher there in the past, a process of shifting
genetic baselines. 相似文献
47.
Regina Coeli Elio H. Baba Neusa Araujo Paulo M. Z. Coelho Guilherme Oliveira 《PLoS neglected tropical diseases》2013,7(12)
Background
Schistosomiasis has a considerable impact on public health in many tropical and subtropical areas. In the new world, schistosomiasis is caused by the digenetic trematode Schistosoma mansoni. Chemotherapy is the main measure for controlling schistosomiasis, and the current drug of choice for treatment is praziquantel (PZQ). Although PZQ is efficient and safe, its repetitive large-scale use in endemic areas may lead to the selection of resistant strains. Isolates less susceptible to PZQ have been found in the field and selected for in the laboratory. The impact of selecting strains with a decreased susceptibility phenotype on disease dynamics and parasite population genetics is not fully understood. This study addresses the impact of PZQ pressure on the genetics of a laboratory population by analyzing frequency variations of polymorphic genetic markers.Methodology
Infected mice were treated with increasing PZQ doses until the highest dose of 3×300 mg/Kg was reached. The effect of PZQ treatment on the parasite population was assessed using five polymorphic microsatellite markers. Parasitological and genetic data were compared with those of the untreated control. After six parasite generations submitted to treatment, it was possible to obtain a S. mansoni population with decreased susceptibility to PZQ. In our experiments we also observed that female worms were more susceptible to PZQ than male worms.Conclusions
The selective pressure exerted by PZQ led to decreased genetic variability in S. mansoni and increased endogamy. The understanding of how S. mansoni populations respond to successive drug pressure has important implications on the appearance and maintenance of a PZQ resistance phenotype in endemic regions. 相似文献48.
Bompadre Thiago F. V. Moretti Débora B. Sakita Gabriel Z. Ieda Egon H. Martinez Maria I. V. Fernandes Elisabete A. N. Machado-Neto Raul Abdalla Adibe L. Louvandini Helder 《Biological trace element research》2020,193(2):414-421
Biological Trace Element Research - Chromium (Cr) is a micromineral that is involved in the metabolism of carbohydrates, lipids, ammonia, and nucleic acids; thus, its supplementation can influence... 相似文献
49.
Heidi L. Hargarten Mattias L. Johansson Daniel C. Reed Nelson C. Coelho David A. Siegel Filipe Alberto 《Journal of phycology》2020,56(1):110-120
We conducted a population genetic analysis of the stalked kelp, Pterygophora californica, in the Santa Barbara Channel, California, USA. The results were compared with previous work on the genetic differentiation of giant kelp, Macrocystis pyrifera, in the same region. These two sympatric kelps not only share many life history and dispersal characteristics but also differ in that dislodged P. californica does not produce floating rafts with buoyant fertile sporophytes, commonly observed for M. pyrifera. We used a comparative population genetic approach with these two species to test the hypothesis that the ability to produce floating rafts increases the genetic connectivity among kelp patches in the Santa Barbara Channel. We quantified the association of habitat continuity and oceanographic distance with the genetic differentiation observed in stalked kelp, like previously conducted for giant kelp. We compared both overall (across all patches) and pairwise (between patches) genetic differentiation. We found that oceanographic transit time, habitat continuity, and geographic distance were all associated with genetic connectivity in P. californica, supporting similar previous findings for M. pyrifera. Controlling for differences in heterozygosity between kelp species using Jost's DEST, we showed that global differentiation and pairwise differentiation were similar among patches between the two kelp species, indicating that they have similar dispersal capabilities despite their differences in rafting ability. These results suggest that rafting sporophytes do not play a significant role in effective dispersal of M. pyrifera at ecologically relevant spatial and temporal scales. 相似文献
50.
Anton Débora Bublitz Guzman Frank Lino Vetö Nicole Moreira Krause Felipe Augusto Kulcheski Franceli Rodrigues Coelho Ana Paula Durand Duarte Guilherme Leitão Margis Rogério Dillenburg Lúcia Rebello Turchetto-Zolet Andreia Carina 《Molecular biology reports》2020,47(2):1033-1043
Molecular Biology Reports - Eugenia uniflora is an Atlantic Forest native species, occurring in contrasting edaphoclimatic environments. The identification of genes involved in response to abiotic... 相似文献