7 resultados para Characters and characteristics in literature.
em Université de Lausanne, Switzerland
Resumo:
HIV latency is a major obstacle to curing infection. Current strategies to eradicate HIV aim at increasing transcription of the latent provirus. In the present study we observed that latently infected CD4+ T cells from HIV-infected individuals failed to produce viral particles upon ex vivo exposure to SAHA (vorinostat), despite effective inhibition of histone deacetylases. To identify steps that were not susceptible to the action of SAHA or other latency reverting agents, we used a primary CD4+ T cell model, joint host and viral RNA sequencing, and a viral-encoded reporter. This model served to investigate the characteristics of latently infected cells, the dynamics of HIV latency, and the process of reactivation induced by various stimuli. During latency, we observed persistence of viral transcripts but only limited viral translation. Similarly, the reactivating agents SAHA and disulfiram successfully increased viral transcription, but failed to effectively enhance viral translation, mirroring the ex vivo data. This study highlights the importance of post-transcriptional blocks as one mechanism leading to HIV latency that needs to be relieved in order to purge the viral reservoir.
Resumo:
Purpose: The purpose of this study was to compare the plaque morphology between coronary and peripheral arteries using intravascular ultrasound (IVUS). Methods: IVUS was performed in 68 patients with coronary and 93 with peripheral artery lesions (29 carotid, 50 renal, and 14 iliac). Plaques were classified as fibroatheroma (VH-FA) (further subclassified as thin-capped [VH-TCFA] and thick-capped [VH-ThCFA]), fibrocalcific plaque (VH-FC) and pathological intimal thickening (VH-PIT). Results: Plaque rupture (13% of coronary, 7% of carotid, 6% of renal, and 7% of iliac arteries; P=NS) and VH-TCFA (37% of coronary, 24% of carotid, 16% of renal, and 7% of iliac arteries; P=0.02) was observed in all arteries. Compared to coronary arteries, VH-FA was less frequently observed in renal (P<0.001) and iliac arteries (P<0.006), while VH-PIT and VH-FC were prevalent in both of these peripheral arteries. Lesions with positive remodeling demonstrated more characteristics of VH-FA in coronary, carotid, and renal arteries compared to those with intermediate/negative remodeling (all P<0.01). There was positive relationship between RI and percent necrotic core area in all four arteries. Conclusions: Atherosclerotic plaque phenotypes were heterogeneous among four different arteries. In contrast, the associations of remodeling mode with plaque phenotype and composition were similar among the various arterial beds.
Resumo:
BACKGROUND: The oral cavity is frequently affected in patients with inflammatory bowel disease (IBD), especially in patients with Crohn's disease (CD). Periodontitis is thought to influence systemic autoimmune or inflammatory diseases. We aimed to analyze the relationship of periodontitis and gingivitis markers with specific disease characteristics in patients with IBD and to compare these data with healthy controls. METHODS: In a prospective 8-month study, systematic oral examinations were performed in 113 patients with IBD, including 69 patients with CD and 44 patients with ulcerative colitis. For all patients, a structured personal history was taken. One hundred thirteen healthy volunteers served as a control group. Oral examination focussed on established oral health markers for periodontitis (bleeding on probing, loss of attachment, and periodontal pocket depth) and gingivitis (papilla bleeding index). Additionally, visible oral lesions were documented. RESULTS: Both gingivitis and periodontitis markers were higher in patients with IBD than in healthy control. In univariate analysis and logistic regression analysis, perianal disease was a risk factor for periodontitis. Nonsmoking decreased the risk of having periodontitis. No clear association was found between clinical activity and periodontitis in IBD. In only the CD subgroup, high clinical activity (Harvey-Bradshaw index > 10) was associated with 1 periodontitis marker, the loss of attachment at sites of maximal periodontal pocket depth. Oral lesions besides periodontitis and gingivitis were not common, but nevertheless observed in about 10% of patients with IBD. CONCLUSIONS: IBD, and especially perianal disease in CD, is associated with periodontitis. Optimal therapeutic strategies should probably focus on treating both local oral and systemic inflammation.
Resumo:
Three-dimensional segmented echo planar imaging (3D-EPI) is a promising approach for high-resolution functional magnetic resonance imaging, as it provides an increased signal-to-noise ratio (SNR) at similar temporal resolution to traditional multislice 2D-EPI readouts. Recently, the 3D-EPI technique has become more frequently used and it is important to better understand its implications for fMRI. In this study, the temporal SNR characteristics of 3D-EPI with varying numbers of segments are studied. It is shown that, in humans, the temporal variance increases with the number of segments used to form the EPI acquisition and that for segmented acquisitions, the maximum available temporal SNR is reduced compared to single shot acquisitions. This reduction with increased segmentation is not found in phantom data and thus likely due to physiological processes. When operating in the thermal noise dominated regime, fMRI experiments with a motor task revealed that the 3D variant outperforms the 2D-EPI in terms of temporal SNR and sensitivity to detect activated brain regions. Thus, the theoretical SNR advantage of a segmented 3D-EPI sequence for fMRI only exists in a low SNR situation. However, other advantages of 3D-EPI, such as the application of parallel imaging techniques in two dimensions and the low specific absorption rate requirements, may encourage the use of the 3D-EPI sequence for fMRI in situations with higher SNR.
Resumo:
This study assesses gender differences in spatial and non-spatial relational learning and memory in adult humans behaving freely in a real-world, open-field environment. In Experiment 1, we tested the use of proximal landmarks as conditional cues allowing subjects to predict the location of rewards hidden in one of two sets of three distinct locations. Subjects were tested in two different conditions: (1) when local visual cues marked the potentially-rewarded locations, and (2) when no local visual cues marked the potentially-rewarded locations. We found that only 17 of 20 adults (8 males, 9 females) used the proximal landmarks to predict the locations of the rewards. Although females exhibited higher exploratory behavior at the beginning of testing, males and females discriminated the potentially-rewarded locations similarly when local visual cues were present. Interestingly, when the spatial and local information conflicted in predicting the reward locations, males considered both spatial and local information, whereas females ignored the spatial information. However, in the absence of local visual cues females discriminated the potentially-rewarded locations as well as males. In Experiment 2, subjects (9 males, 9 females) were tested with three asymmetrically-arranged rewarded locations, which were marked by local cues on alternate trials. Again, females discriminated the rewarded locations as well as males in the presence or absence of local cues. In sum, although particular aspects of task performance might differ between genders, we found no evidence that women have poorer allocentric spatial relational learning and memory abilities than men in a real-world, open-field environment.
Resumo:
BACKGROUND: The numbers of people attending emergency departments (EDs) at hospitals are increasing. We aimed to analyse trends in ED attendance at a Swiss university hospital between 2002 and 2012, focussing on age-related differences and hospital admission criteria. METHODS: We used hospital administrative data for all patients aged ≥16 years who attended the ED (n = 298,306) at this university hospital between 1 January 2002, and 31 December 2012. We descriptively analysed the numbers of ED visits according to the admission year and stratified by age (≥65 vs <65 years). RESULTS: People attending the ED were on average 46.6 years old (standard deviation 20 years, maximum range 16‒99 years). The annual number of ED attendances grew by n = 6,639 (27.6%) from 24,080 in 2002 to 30,719 in 2012. In the subgroup of patients aged ≥65 the relative increase was 42.3%, which is significantly higher (Pearson's χ2 = 350.046, df = 10; p = 0.000) than the relative increase of 23.4% among patients <65 years. The subgroup of patients ≥65 years attended the ED more often because of diseases (n = 56,307; 85%) than accidents (n = 9,844; 14.9%). This subgroup (patients ≥65 years) was also more often admitted to hospital (Pearson's χ2 = 23,377.190; df = 1; p = 0.000) than patients <65 years. CONCLUSIONS: ED attendance of patients ≥65 years increased in absolute and relative terms. The study findings suggest that staff of this ED may want to assess the needs of patients ≥65 years and, if necessary, adjust the services (e.g., adapted triage scales, adapted geriatric screenings, and adapted hospital admission criteria).
Resumo:
In a 2000 report entitled "Trust in government. Ethics measures in OECD countries," OECD Secretary-General Donald J. Johnston emphasized the fact that public ethics are considered as a keystone of good governance. Moreover, public ethics are a prerequisite to public trust, which is in turn vital not only to any public service, but also to any society in general. At the same time, transparency reforms have flourished over the last few years and have several times been designed as a response to public distrust. Therefore, ethics, transparency and trust are closely linked together in a supposed virtuous circle where transparency works as a factor of better public ethics and leads to more trust in government on the citizens' side. This article explores the links between transparency and levels of trust in 10 countries between 2007 and 2014, using open data indexes and access to information requests as proxies for transparency. A national ranking of transparency, based on requests submitted by citizens to the administration and open data indexes, is then proposed. Key findings show that there is no sharp decline of trust in government in all countries considered in this article, and that transparency and trust in government are not systematically positively associated. Therefore, this article challenges the common assumption, mostly found in the normative literature, about a positive interrelation between the two, where trust in government is conceived as a beneficial effect of administrative transparency.