839 resultados para Class-based isolation vs. sharing


Relevância:

40.00% 40.00%

Publicador:

Resumo:

The 18S rDNA phylogeny of Class Armophorea, a group of anaerobic ciliates, is proposed based on an analysis of 44 sequences (out of 195) retrieved from the NCBI/GenBank database. Emphasis was placed on the use of two nucleotide alignment criteria that involved variation in the gap-opening and gap-extension parameters and the use of rRNA secondary structure to orientate multiple-alignment. A sensitivity analysis of 76 data sets was run to assess the effect of variations in indel parameters on tree topologies. Bayesian inference, maximum likelihood and maximum parsimony phylogenetic analyses were used to explore how different analytic frameworks influenced the resulting hypotheses. A sensitivity analysis revealed that the relationships among higher taxa of the Intramacronucleata were dependent upon how indels were determined during multiple-alignment of nucleotides. The phylogenetic analyses rejected the monophyly of the Armophorea most of the time and consistently indicated that the Metopidae and Nyctotheridae were related to the Litostomatea. There was no consensus on the placement of the Caenomorphidae, which could be a sister group of the Metopidae + Nyctorheridae, or could have diverged at the base of the Spirotrichea branch or the Intramacronucleata tree.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

We propose a resource-sharing scheme that supports three kinds of sharing scenarios in a WDM mesh network with path-based protection and sparse OEO regeneration. Several approaches are used to maximize the sharing of wavelength-links and OEO regenerators.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Several pharmacological targets have been proposed as modulators of panic-like reactions. However, interest should be given to other potential therapeutic neurochemical agents. Recent attention has been given to the potential anxiolytic properties of cannabidiol, because of its complex actions on the endocannabinoid system together with its effects on other neurotransmitter systems. The aim of this study was to investigate the effects of cannabidiol on innate fear-related behaviors evoked by a prey vs predator paradigm. Male Swiss mice were submitted to habituation in an arena containing a burrow and subsequently pre-treated with intraperitoneal administrations of vehicle or cannabidiol. A constrictor snake was placed inside the arena, and defensive and non-defensive behaviors were recorded. Cannabidiol caused a clear anti-aversive effect, decreasing explosive escape and defensive immobility behaviors outside and inside the burrow. These results show that cannabidiol modulates defensive behaviors evoked by the presence of threatening stimuli, even in a potentially safe environment following a fear response, suggesting a panicolytic effect. Neuropsychopharmacology (2012) 37, 412-421; doi:10.1038/npp.2011.188; published online 14 September 2011

Relevância:

40.00% 40.00%

Publicador:

Resumo:

In this work we present an agent-based model for the spread of tuberculosis where the individuals can be infected with either drug-susceptible or drug-resistant strains and can also receive a treatment. The dynamics of the model and the role of each one of the parameters are explained. The whole set of parameters is explored to check their importance in the numerical simulation results. The model captures the beneficial impact of the adequate treatment on the prevalence of tuberculosis. Nevertheless, depending on the treatment parameters range, it also captures the emergence of drug resistance. Drug resistance emergence is particularly likely to occur for parameter values corresponding to less efficacious treatment, as usually found in developing countries.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Abstract Background An important challenge for transcript counting methods such as Serial Analysis of Gene Expression (SAGE), "Digital Northern" or Massively Parallel Signature Sequencing (MPSS), is to carry out statistical analyses that account for the within-class variability, i.e., variability due to the intrinsic biological differences among sampled individuals of the same class, and not only variability due to technical sampling error. Results We introduce a Bayesian model that accounts for the within-class variability by means of mixture distribution. We show that the previously available approaches of aggregation in pools ("pseudo-libraries") and the Beta-Binomial model, are particular cases of the mixture model. We illustrate our method with a brain tumor vs. normal comparison using SAGE data from public databases. We show examples of tags regarded as differentially expressed with high significance if the within-class variability is ignored, but clearly not so significant if one accounts for it. Conclusion Using available information about biological replicates, one can transform a list of candidate transcripts showing differential expression to a more reliable one. Our method is freely available, under GPL/GNU copyleft, through a user friendly web-based on-line tool or as R language scripts at supplemental web-site.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Many potential diltiazem related L-VDCC blockers were developed using a multidisciplinary approach. This current study was to investigate and compare diltiazem with to the newly developed compounds by mouse Langendorff-perfused heart, Ca2+-transient and on recombinant L-VDCC. Twenty particular compounds were selected by the ligand-based virtual screening procedure (LBVS). From these compounds, five of them (5b, M2, M7, M8 and P1) showed a potent and selective inotropic activity on guinea-pig left atria driven 1 Hz. Further assays displayed an interesting negative inotropic effect of M2, M8, P1 and M7 on guinea pig isolated left papillary muscle driven at 1 Hz, a relevant vasorelaxant activity of 5b, M2, M7, M8 and P1 on K+-depolarized guinea-pig ileum longitudinal smooth muscle and a significant inhibition of contraction of 5b, M2, M8 and P1 on carbachol stimulated ileum longitudinal smooth muscle. Wild-type human heart and rabbit lung α1 subunits were expressed (combined with the regulatory α2δ and β3 subunits) in Xenopus Leavis oocytes using a two-electrode voltage clamp technique. Diltiazem is a benzothiazepine Ca2+ channel blocker used clinically for its antihypertensive and antiarrhythmic effects. Previous radioligand binding assays revealed a complex interaction with the benzothiazepine binding site for M2, M7 and M8. (Carosati E. et al. J. Med Chem. 2006, 49; 5206). In agreement with this findings, the relative order of increased rates of contraction and relaxation at lower concentrations s(≤10-6M) in unpaced hearts was M7>M2>M8>P1. Similar increases in Ca2+ transient were observed in cardiomyocytes. Diltiazem showed negative inotropic effects whereas 5b had no significant effect. Diltiazem blocks Ca2+current in a use-dependent manner and facilitates the channel by accelerating the inactivation and decelerating the recovery from inactivation. In contrast to diltiazem, the new analogs had no pronounced use-dependence. Application of 100 μM M8, M2 showed ~ 10% tonic block; in addition, M8, M2 and P1 shifted the steady state inactivation in hyperpolarized direction and the current inactivation time was significantly decreased compared with control (219.6 ± 11.5 ms, 226 ± 14.5 vs. 269 ± 12.9 vs. 199.28 ± 8.19 ms). Contrary to diltiazem, the recovery from the block by M8 and M2 was comparable to control. Only P1 showed a significantly decrease of the time for the recovery from inactivation. All of the compounds displayed the same sensitivity on the Ca2+ channel rabbit lung α1 except P1. Taken together, these findings suggest that M8, M2 and P1 might directly decrease the binding affinity or allow rapid dissociation from the benzothiazepine binding site.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Inflammatory Bowel Diseases (IBD) are intestinal chronic relapsing diseases which ethiopathogenesis remains uncertain. Several group have attempted to study the role of factors involved such as genetic susceptibility, environmental factors such as smoke, diet, sex, immunological factors as well as the microbioma. None of the treatments available satisfy several criteria at the same time such as safety, long-term remission, histopatological healing, and specificity. We used two different approaches for the development of new therapeutic treatment for Inflammatory Bowel Disease. The first is focused on the understanding of the potential role of functional food and nutraceuticals nutrients in the treatment of IBD. To do so, we investigated the role of Curcuma longa in the treatment of chemical induced colitis in mice model. Since Curcma Longa has been investigated for its antinflammatory role related to the TNFα pathway as well investigators have reported few cases of patients with ulcerative colites treated with this herbs, we harbored the hypothesis of a role of Curcuma Longa in the treatment f IBD as well as we decided to assess its role in intestinal motility. The second part is based on an immunological approach to develop new drugs to induce suppression in Crohn’s disease or to induce mucosa immunity such as in colonrectal tumor. The main idea behind this approach is that we could manipulate relevant cell-cell interactions using synthetic peptides. We demonstrated the role of the unique interaction between molecules expressed on intestinal epithelial cells such as CD1d and CEACAM5 and on CD8+ T cells. In normal condition this interaction has a role for the expansion of the suppressor CD8+ T cells. Here, we characterized this interaction, we defined which are the epitope involved in the binding and we attempted to develop synthetic peptides from the N domain of CEACAM5 in order to manipulate it.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

A variety of radiolabeled somatostatin analogs have been developed for targeting of somatostatin receptor (sst)-positive tumors. Bicyclic somatostatin-based radiopeptides have not been studied yet. Hypothesizing that the introduction of conformational constraints may lead to receptor subtype selectivity or may help to delineate structural features determining pansomatostatin potency, we developed and evaluated first examples of this new class of potential radiotracers for imaging or therapy of neuroendocrine tumors.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Statistical models have been recently introduced in computational orthopaedics to investigate the bone mechanical properties across several populations. A fundamental aspect for the construction of statistical models concerns the establishment of accurate anatomical correspondences among the objects of the training dataset. Various methods have been proposed to solve this problem such as mesh morphing or image registration algorithms. The objective of this study is to compare a mesh-based and an image-based statistical appearance model approaches for the creation of nite element(FE) meshes. A computer tomography (CT) dataset of 157 human left femurs was used for the comparison. For each approach, 30 finite element meshes were generated with the models. The quality of the obtained FE meshes was evaluated in terms of volume, size and shape of the elements. Results showed that the quality of the meshes obtained with the image-based approach was higher than the quality of the mesh-based approach. Future studies are required to evaluate the impact of this finding on the final mechanical simulations.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Posterior lumbar fusion is a frequently performed procedure in spinal surgery. High percentages of good and excellent results are indicated by physicians. On the other hand patient-based outcomes are reported. Little is known about the correlations of these two assessment types. We aimed at their comparison. The analysis included 1013 patients with degenerative spinal disease or spondylolisthesis from an international spine registry, treated with posterior lumbar fusion. All patients were pre/postop assessed by physician-based McNab criteria (‘excellent’, ‘good’, ‘fair’, ‘poor’). Of these patients, 210 (mean age 61 years; 57% females) were in addition assessed by patient-based Oswestry Disability Index (ODI). The remaining 803 patients (mean age 59 years; 56% females) were assessed by patient-based Core Outcome Measure Index (COMI), including Visual Analogue Scale (VAS) for back and leg pain as well as verbal self-rating (‘helped a lot’, ‘helped’, ‘helped only little’, ‘didn’t help’, ‘made things worse’). McNab criteria were compared to the Minimal Clinically Important Difference (MCID) in ODI (12.8), in VAS back (1.2) and leg pain (1.6). We investigated the correlations between McNab criteria and these patient-based outcomes. In the ‘excellent’ group as rated by physicians, the proposed MCID was reached in 83% of patients for ODI, in 69% for VAS back and in 83% for VAS leg pain. All patients said the treatment had ‘helped’ or ‘helped a lot’. In the ‘good’ group 56% (ODI), 66% (back pain) and 86% (leg pain) reached the MCID. 96% of patients perceived the treatment as positive. In the ‘fair’ group 37% (ODI), 55% (back pain) and 63% (leg pain) reached the MCID. 49% had positive treatment considerations. The ‘poor’ group revealed 30% (ODI), 35% (back pain) and 44% (leg pain) of patients with reached MCID. Only 15% rated the treatment as positive. The Spearman correlation coefficients between McNab criteria on the one hand and ODI, back and leg pain as well as patients’ verbal self-rating on the other hand were 0.57, 0.37, 0.36 and 0.46 respectively. The comparison of physician and patient-based outcomes showed the highest correlations between McNab criteria and ODI, somewhat weaker correlations with patients’ self-rating and the weakest correlations with back and leg pain. Based on these findings, physicians’ evaluation of patient outcomes can be considered a valuable part of patient assessment, corresponding very well with patients’ perceptions of success or failure of spinal surgery.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

To assess the relative impact of cognitive and emotional aspects of shared decision making (SDM) on patient outcomes.