996 resultados para Temporal Enhanced Ultrasound
Resumo:
In mice, vaccination with high peptide doses generates higher frequencies of specific CD8+ T cells, but with lower avidity compared to vaccination with lower peptide doses. To investigate the impact of peptide dose on CD8+ T cell responses in humans, melanoma patients were vaccinated with 0.1 or 0.5 mg Melan-A/MART-1 peptide, mixed with CpG 7909 and Incomplete Freund's adjuvant. Neither the kinetics nor the amplitude of the Melan-A-specific CD8+ T cell responses differed between the two vaccination groups. Also, CD8+ T cell differentiation and cytokine production ex vivo were similar in the two groups. Interestingly, after low peptide dose vaccination, Melan-A-specific CD8+ T cells showed enhanced degranulation upon peptide stimulation, as assessed by CD107a upregulation and perforin release ex vivo. In accordance, CD8+ T cell clones derived from low peptide dose-vaccinated patients showed significantly increased degranulation and stronger cytotoxicity. In parallel, Melan-A-specific CD8+ T cells and clones from low peptide dose-vaccinated patients expressed lower CD8 levels, despite similar or even stronger binding to tetramers. Furthermore, CD8+ T cell clones from low peptide dose-vaccinated patients bound CD8 binding-deficient tetramers more efficiently, suggesting that they may express higher affinity TCRs. We conclude that low peptide dose vaccination generated CD8+ T cell responses with stronger cytotoxicity and lower CD8 dependence.
Resumo:
Accurate perception of the temporal order of sensory events is a prerequisite in numerous functions ranging from language comprehension to motor coordination. We investigated the spatio-temporal brain dynamics of auditory temporal order judgment (aTOJ) using electrical neuroimaging analyses of auditory evoked potentials (AEPs) recorded while participants completed a near-threshold task requiring spatial discrimination of left-right and right-left sound sequences. AEPs to sound pairs modulated topographically as a function of aTOJ accuracy over the 39-77ms post-stimulus period, indicating the engagement of distinct configurations of brain networks during early auditory processing stages. Source estimations revealed that accurate and inaccurate performance were linked to bilateral posterior sylvian regions activity (PSR). However, activity within left, but not right, PSR predicted behavioral performance suggesting that left PSR activity during early encoding phases of pairs of auditory spatial stimuli appears critical for the perception of their order of occurrence. Correlation analyses of source estimations further revealed that activity between left and right PSR was significantly correlated in the inaccurate but not accurate condition, indicating that aTOJ accuracy depends on the functional decoupling between homotopic PSR areas. These results support a model of temporal order processing wherein behaviorally relevant temporal information--i.e. a temporal 'stamp'--is extracted within the early stages of cortical processes within left PSR but critically modulated by inputs from right PSR. We discuss our results with regard to current models of temporal of temporal order processing, namely gating and latency mechanisms.
Resumo:
AIM: Alpha1-adrenergic receptors (alpha1-ARs) are classified into three subtypes: alpha1A-AR, alpha1B-AR, and alpha1D-AR. Triple disruption of alpha1A-AR, alpha1B-AR, and alpha1D-AR genes results in hypotension and produces no contractile response of the thoracic aorta to noradrenalin. Presently, we characterized vascular contractility against other vasoconstrictors, such as potassium, prostaglandin F2alpha (PGF(2alpha)) and 5-hydroxytryptamine (5-HT), in alpha1A-AR, alpha1B-AR, and alpha1D-AR triple knockout (alpha1-AR triple KO) mice. MAIN METHODS: The contractile responses to the stimulation with vasoconstrictors were studied using isolated thoracic aorta. KEY FINDINGS: As a result, the phasic and tonic contraction induced by a high concentration of potassium (20 mM) was enhanced in the isolated thoracic aorta of alpha1-AR triple KO mice compared with that of wild-type (WT) mice. In addition, vascular responses to PGF(2alpha) and 5-HT were also enhanced in the isolated thoracic aorta of alpha1-AR triple KO mice compared with WT mice. Similar to in vitro findings with isolated thoracic aorta, in vivo pressor responses to PGF(2alpha) were enhanced in alpha1-AR triple KO mice. Real-time reverse transcription-polymerase chain reaction analysis and western blot analysis indicate that gene expression of the 5-hydroxytryptamine 2A (5-HT(2A)) receptor was up-regulated in the thoracic aorta of alpha1-AR triple KO mice while the prostaglandin F2alpha receptor (FP) was unchanged. SIGNIFICANCE: These results suggest that loss of alpha1-ARs can lead to enhancement of vascular responsiveness to the vasoconstrictors and may imply that alpha1-ARs and the subsequent signaling regulate the vascular responsiveness to other stimulations such as depolarization, 5-HT and PGF(2alpha).
Resumo:
En aquest treball s’ha estudiat la variabilitat temporal i espacial en l’acumulació de sediment fi a la llera del riu Isàbena (Conca de l’Ebre) al llarg d’un any (1 de Juny de 2007 al 31 de maig de 2008) així com la seva relació amb l’arribada de sediments a l’embassament de Barasona, amb el mètode directe de camp, en aquest cas el cilindre de resuspensió. Aquesta tècnica s’ha aplicat a quatre seccions ubicades al tram baix de l’Isàbena. Amb les dades obtingudes, s’ha analitzat la dinàmica de les acumulacions a les diferents estacions de l’any, tractant de trobar patrons característics.
Resumo:
Awareness is required for supporting all forms of cooperation. In Computer Supported Collaborative Learning (CSCL), awareness can be used for enhancing collaborative opportunities across physical distances and in computer-mediated environments. Shared Knowledge Awareness (SKA) intends to increase the perception about the shared knowledge, students have in a collaborative learning scenario and also concerns the understanding that this group has about it. However, it is very difficult to produce accurate awareness indicators based on informal message exchange among the participants. Therefore, we propose a semantic system for cooperation that makes use of formal methods for knowledge representation based on semantic web technologies. From these semantics-enhanced repository and messages, it could be easier to compute more accurate awareness.
Resumo:
The concept of temporal 'plus' epilepsy (T+E) is not new, and a number of observations made by means of intracerebral electrodes have illustrated the complexity of neuronal circuits that involve the temporal lobe. The term T+E was used to unify and better individualize these specific forms of multilobar epilepsies, which are characterized by electroclinical features primarily suggestive of temporal lobe epilepsy, MRI findings that are either unremarkable or show signs of hippocampal sclerosis, and intracranial recordings which demonstrate that seizures arise from a complex epileptogenic network including a combination of brain regions located within the temporal lobe and over closed neighbouring structures such as the orbitofrontal cortex, the insulo-opercular region, and the temporo-parieto-occipital junction. We will review here how the term of T+E has emerged, what it means, and which practical consideration it raises.
Resumo:
OBJECTIVE: To compare epidural analgesia (EDA) to patient-controlled opioid-based analgesia (PCA) in patients undergoing laparoscopic colorectal surgery. BACKGROUND: EDA is mainstay of multimodal pain management within enhanced recovery pathways [enhanced recovery after surgery (ERAS)]. For laparoscopic colorectal resections, the benefit of epidurals remains debated. Some consider EDA as useful, whereas others perceive epidurals as unnecessary or even deleterious. METHODS: A total of 128 patients undergoing elective laparoscopic colorectal resections were enrolled in a randomized clinical trial comparing EDA versus PCA. Primary end point was medical recovery. Overall complications, hospital stay, perioperative vasopressor requirements, and postoperative pain scores were secondary outcome measures. Analysis was performed according to the intention-to-treat principle. RESULTS: Final analysis included 65 EDA patients and 57 PCA patients. Both groups were similar regarding baseline characteristics. Medical recovery required a median of 5 days (interquartile range [IQR], 3-7.5 days) in EDA patients and 4 days (IQR, 3-6 days) in the PCA group (P = 0.082). PCA patients had significantly less overall complications [19 (33%) vs 35 (54%); P = 0.029] but a similar hospital stay [5 days (IQR, 4-8 days) vs 7 days (IQR, 4.5-12 days); P = 0.434]. Significantly more EDA patients needed vasopressor treatment perioperatively (90% vs 74%, P = 0.018), the day of surgery (27% vs 4%, P < 0.001), and on postoperative day 1 (29% vs 4%, P < 0.001), whereas no difference in postoperative pain scores was noted. CONCLUSIONS: Epidurals seem to slow down recovery after laparoscopic colorectal resections without adding obvious benefits. EDA can therefore not be recommended as part of ERAS pathways in laparoscopic colorectal surgery.
Resumo:
OBJECTIVES: Regarding recent progress, musculoskeletal ultrasound (US) will probably soon be integrated in standard care of patient with rheumatoid arthritis (RA). However, in daily care, quality of US machines and level of experience of sonographers are varied. We conducted a study to assess reproducibility and feasibility of an US scoring for RA, including US devices of different quality and rheumatologist with various levels of expertise in US as it would be in daily care. METHODS: The Swiss Sonography in Arthritis and Rheumatism (SONAR) group has developed a semi-quantitative score using OMERACT criteria for synovitis and erosion in RA. The score was taught to 108 rheumatologists trained in US. One year after the last workshop, 19 rheumatologists participated in the study. Scans were performed on 6 US machines ranging from low to high quality, each with a different patient. Weighted kappa was calculated for each pair of readers. RESULTS: Overall, the agreement was fair to moderate. Quality of device, experience of the sonographers and practice of the score before the study improved substantially the agreement. Agreement assessed on higher quality machine, among sonographers with good experience in US increased to substantial (median kappa for B-mode and Doppler: 0.64 and 0.41 for erosion). CONCLUSIONS: This study demonstrated feasibility and reproducibility of the Swiss US SONAR score for RA. Our results confirmed importance of the quality of US machine and the training of sonographers for the implementation of US scoring in the routine daily care of RA.