103 resultados para very long path length

em Université de Lausanne, Switzerland


Relevância:

100.00% 100.00%

Publicador:

Resumo:

A very long half-life of paroxetine (195 h instead of the usual value of around 16 h) was measured after an overdose with 2 g paroxetine and 1 g clorazepate in a patient who was an extensive cytochrome P4502D6 metabolizer. The patient recovered well without any clinically significant complications. A consequence of the close monitoring of paroxetine levels in this patient was that it was decided not to reintroduce any other antidepressant despite her suicide attempt, until normal levels of paroxetine had been reached, which took over 1 month.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Over the past decade a series of trials of the EORTC Brain Tumor Group (BTG) has substantially influenced and shaped the standard-of-care of primary brain tumors. All these trials were coupled with biological research that has allowed for better understanding of the biology of these tumors. In glioblastoma, EORTC trial 26981/22981 conducted jointly with the National Cancer Institute of Canada Clinical Trials Group showed superiority of concomitant radiochemotherapy with temozolomide over radiotherapy alone. It also identified the first predictive marker for benefit from alkylating agent chemotherapy in glioblastoma, the methylation of the O6-methyl-guanyl-methly-transferase (MGMT) gene promoter. In another large randomized trial, EORTC 26951, adjuvant chemotherapy in anaplastic oligodendroglial tumors was investigated. Despite an improvement in progression-free survival this did not translate into a survival benefit. The third example of a landmark trial is the EORTC 22845 trial. This trial led by the EORTC Radiation Oncology Group forms the basis for an expectative approach to patients with low-grade glioma, as early radiotherapy indeed prolongs time to tumor progression but with no benefit in overall survival. This trial is the key reference in deciding at what time in their disease adult patients with low-grade glioma should be irradiated. Future initiatives will continue to focus on the conduct of controlled trials, rational academic drug development as well as systematic evaluation of tumor tissue including biomarker development for personalized therapy. Important lessons learned in neurooncology are to dare to ask real questions rather than merely rapidly testing new compounds, and the value of well designed trials, including the presence of controls, central pathology review, strict radiology protocols and biobanking. Structurally, the EORTC BTG has evolved into a multidisciplinary group with strong transatlantic alliances. It has contributed to the maturation of neurooncology within the oncological sciences.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

AIMS: To evaluate the very long-term risk of recurrent thromboembolic events in patients treated by percutaneous PFO closure. METHODS AND RESULTS: Between 1998 and 2008, a total of 232 consecutive patients with PFO and a high suspicion of paradoxical embolism were treated by percutaneous closure. The following major events were observed during hospitalisation: implantation failure (one patient) and appearance of an acute left-sided device thrombus requiring surgery (one patient). The primary endpoint of the study was a recurrent embolic event beyond at least five years' follow-up. During a mean follow-up of 7.6±2.4 years, this event occurred in five patients, representing a 0.28% annual/patient risk. Other major complications during follow-up were the following: late thrombus formation on the device (two patients) and transient atrial fibrillation (15 patients). Three patients died during follow-up from cardiovascular causes considered not related to the index procedure. The PFO was judged closed on follow-up echocardiography in 92.3% of patients. CONCLUSIONS: Long-term follow-up following percutaneous PFO closure for presumed paradoxical embolism reveals very low recurrence rates. This observation should be put in perspective with recent published randomised trials comparing percutaneous closure and medical therapy.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Hip or knee arthroplasty is proposed after osteoarthritis or an accident. It is decided after a long path of pain and decrease in the quality of life. This research explores the period of illness until surgery. Twenty-four semi-structured interviews were conducted one month before surgery and a thematic discourse analysis performed. The diversity and complexity of the patient experience, in a commonly performed surgical intervention underlines important topics, requiring attention in order to improve patient preparations and information prior to arthroplasty: information adapted to individual concerns, needs and representations. Psychological and physical acceptance is necessary for integration of the prosthesis.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Growing empirical evidence indicates that invertebrates become more resistant to a pathogen following initial exposure to a nonlethal dose; yet the generality, mechanisms, and adaptive value of such immune priming are still under debate. Because life-history theory predicts that immune priming and large investment in immunity should be more frequent in long-lived species, we here tested for immune priming and pathogen resistance in ant queens, which have extraordinarily long life span. We exposed virgin and mated queens of Lasius niger and Formica selysi to a low dose of the entomopathogenic fungus Beauveria bassiana, before challenging them with a high dose of the same pathogen. We found evidence for immune priming in naturally mated queens of L. niger. In contrast, we found no sign of priming in virgin queens of L. niger, nor in virgin or experimentally mated queens of F. selysi, which indicates that immune priming in ant queens varies according to mating status and mating conditions or species. In both ant species, mated queens showed higher pathogen resistance than virgin queens, which suggests that mating triggers an up-regulation of the immune system. Overall, mated ant queens combine high reproductive output, very long life span, and elevated investment in immune defense. Hence, ant queens are able to invest heavily in both reproduction and maintenance, which can be explained by the fact that mature queens will be protected and nourished by their worker offspring.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Chronic exposure to food of low quality may exert conflicting selection pressures on foraging behaviour. On the one hand, more active search behaviour may allow the animal to find patches with slightly better, or more, food; on the other hand, such active foraging is energetically costly, and thus may be opposed by selection for energetic efficiency. Here, we test these alternative hypotheses in Drosophila larvae. We show that populations which experimentally evolved improved tolerance to larval chronic malnutrition have shorter foraging path length than unselected control populations. A behavioural polymorphism in foraging path length (the rover-sitter polymorphism) exists in nature and is attributed to the foraging locus (for). We show that a sitter strain (for(s2)) survives better on the poor food than the rover strain (for(R)), confirming that the sitter foraging strategy is advantageous under malnutrition. Larvae of the selected and control populations did not differ in global for expression. However, a quantitative complementation test suggests that the for locus may have contributed to the adaptation to poor food in one of the selected populations, either through a change in for allele frequencies, or by interacting epistatically with alleles at other loci. Irrespective of its genetic basis, our results provide two independent lines of evidence that sitter-like foraging behaviour is favoured under chronic larval malnutrition.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Knockout mice lacking alphalb noradrenergic receptors were tested in behavioural experiments to test a possible effect of the absence of this receptor in reaction to novelty and spatial orientation. Reaction to novelty was tested in two experiments. In the first one the mice' latency to exit the first part of a two compartment set-up was measured. The knockout mice were faster to emerge then their littermate controls. Then they were tested in an open-field, in which new objects were added at the second trial. In the open-field without objects (first trial), the knockout mice showed a greater locomotor activity (path length). Then the same mice showed enhanced exploration of the newly introduced objects, relative to the control. The spatial orientation experiments were done on a homing board and in the water maze. The homing board did not yield a significant difference between the knock-out and the control mice. Both groups showed impaired results when the proximal (olfactory) and distal (visual) cues were disrupted by the rotation of the table. In the water maze however, the alphalb(-/-) mice were unable to solve the task (acquisition and retention), whereas the control mice showed a good acquisition and retention behaviour. The knockout mice' incapacity to learn to reach the submerged platform was not due to an incapacity to swim, as they were as good as their control littermates to reach the platform when it was visible.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Patients with Temporal Lobe Epilepsy (TLE) suffer from widespread subtle white matter abnormalities and abnormal functional connectivity extending beyond the affected lobe, as revealed by Diffusion Tensor MR Imaging, volumetric and functional MRI studies. Diffusion Spectrum Imaging (DSI) is a diffusion imaging technique with high angular resolution for improving the mapping of white matter pathways. In this study, we used DSI, connectivity matrices and topological measures to investigate how the alteration in structural connectivity influences whole brain structural networks. Eleven patients with right-sided TLE and hippocampal sclerosis and 18 controls underwent our DSI protocol at 3T. The cortical and subcortical grey matters were parcellated into 86 regions of interest and the connectivity between every region pair was estimated using global tractography and a connectivity matrix (the adjacency matrix of the structural network). We then compared the networks of patients and controls using topological measures. In patients, we found a higher characteristic path length and a lower clustering coefficient compared to controls. Local measures at node level of the clustering and efficiency showed a significant difference after a multiple comparison correction (Bonferroni). These significant nodes were located within as well outside the temporal lobe, and the localisation of most of them was consistent with regions known to be part of epileptic networks in TLE. Our results show altered connectivity patterns that are concordant with the mapping of functional epileptic networks in patients with TLE. Further studies are needed to establish the relevance of these findings for the propagation of epileptic activity, cognitive deficits in medial TLE and outcome of epilepsy surgery in individual patients.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

While early intervention strategies have been developed for psychotic disorders, affective psychoses and bipolar disorders have been neglected by this movement. However, when considering that outcome of bipolar disorders is often not as favorable as previously thought and that delay between illness onset and introduction of an adequate treatment is often very long, such developments seem clearly justified. In this paper we briefly review arguments supporting early intervention in bipolar disorders, the practical and theoretical obstacles that still need to be overcome, the strategies that may already now contribute to decrease treatment delay, and we describe current state of research regarding identification of the prodromal phase of bipolar disorders.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In this study we investigated the effect of medial temporal lobe epilepsy (MTLE) on the global characteristics of brain connectivity estimated by topological measures. We used DSI (Diffusion Spectrum Imaging) to construct a connectivity matrix where the nodes represents the anatomical ROIs and the edges are the connections between any pair of ROIs weighted by the mean GFA/FA values. A significant difference was found between the patient group vs control group in characteristic path length, clustering coefficient and small-worldness. This suggests that the MTLE network is less efficient compared to the network of the control group.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

STUDY OBJECTIVE: To establish guidelines for the diagnosis and management of chylothorax in children. DESIGN: Retrospective study. PATIENTS: Fifty-one patients with a diagnosis of chylothorax. Twelve patients were excluded because of incomplete data or incorrect diagnosis. The following parameters were analyzed: triglyceride level, total cell number, and lymphocyte percentage; amount of pleural effusion on day of diagnosis, day 5, and day 14; and total time of pleural effusion. Prospectively, the same parameters were analyzed in a control group of 10 patients with pleural drainage. INTERVENTION: Patients with chylothorax were treated primarily with fat-free oral nutrition; if chyle did not stop, total parenteral nutrition with total enteric rest was started. If conservative therapy was not successful, pleurodesis was performed. RESULTS: In children with chylothorax triglyceride, triglyceride content ranged from 0.56 to 26.6 mmol/L; all values except one were > 1.1 mmol/L. In 36 of 39 patients (92%), the cell count was > 1,000 cells/microL. In 33 of 39 patients (85%), lymphocytes were > 90%. In patients without chylothorax triglyceride, triglyceride levels ranged from 0.1 to 0.71 mmol/L (median, 0.38 mmol/L) and cell count was from 20 to 1400 cells/microL (median, 322 cells/microL), with a maximum of 60% lymphocytes. With fat-free nutrition, chyle disappeared in 29 of 39 patients. Five patients died, and five required pleurodesis. CONCLUSIONS: Pleural effusion in children is chyle when it contains > 1.1 mmol/L triglycerides (with oral fat intake) and has a total cell count > or 1,000 cells/microL, with a lymphocyte fraction > 80%. Chylous effusions usually last long; however, after 6 weeks, the majority of the effusions (29 of 39 patients) had ceased. Late surgical interventions reduce the number of thoracotomies substantially, but can lead to very long hospitalization times. Early surgical interventions (after < 3 weeks) lead to a high number of thoracotomies, but certainly reduce hospitalization time.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

BACKGROUND: Virtual reality (VR) simulators are widely used to familiarize surgical novices with laparoscopy, but VR training methods differ in efficacy. In the present trial, self-controlled basic VR training (SC-training) was tested against training based on peer-group-derived benchmarks (PGD-training). METHODS: First, novice laparoscopic residents were randomized into a SC group (n = 34), and a group using PGD-benchmarks (n = 34) for basic laparoscopic training. After completing basic training, both groups performed 60 VR laparoscopic cholecystectomies for performance analysis. Primary endpoints were simulator metrics; secondary endpoints were program adherence, trainee motivation, and training efficacy. RESULTS: Altogether, 66 residents completed basic training, and 3,837 of 3,960 (96.8 %) cholecystectomies were available for analysis. Course adherence was good, with only two dropouts, both in the SC-group. The PGD-group spent more time and repetitions in basic training until the benchmarks were reached and subsequently showed better performance in the readout cholecystectomies: Median time (gallbladder extraction) showed significant differences of 520 s (IQR 354-738 s) in SC-training versus 390 s (IQR 278-536 s) in the PGD-group (p < 0.001) and 215 s (IQR 175-276 s) in experts, respectively. Path length of the right instrument also showed significant differences, again with the PGD-training group being more efficient. CONCLUSIONS: Basic VR laparoscopic training based on PGD benchmarks with external assessment is superior to SC training, resulting in higher trainee motivation and better performance in simulated laparoscopic cholecystectomies. We recommend such a basic course based on PGD benchmarks before advancing to more elaborate VR training.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This study was conducted to assess the pharmacologic properties of the new orally active angiotensin II subtype I (AT1) antagonist UR-7247, a product with a half-life >100 h in humans. The experiment was designed as an open-label, single-dose administration study with four parallel groups of four healthy men receiving increasing single oral doses (2.5, 5, and 10 mg) of UR-7247 or losartan, 100 mg. Angiotensin II receptor blockade was investigated < or =96 h after drug intake, with three independent methods [i.e., the inhibition of blood pressure (BP) response to exogenous Ang II, an in vitro Ang II-receptor assay (RRA), and the reactive increase in plasma angiotensin II. Plasma drug levels also were measured. The degree of blockade observed in vivo was statistically significant < or = 96 h with all UR-7247 doses for diastolic BP (p < 0.05) and < or =48 h for systolic BP. The maximal inhibition achieved with 10 mg UR-7247 was measured 6-24 h after drug intake and reached 54 +/- 17% and 48 +/- 20% for diastolic and systolic responses, respectively. Losartan, 100 mg, induced a greater short-term AT1-receptor blockade than 2.5- and 5.0-mg doses of UR-7247 (p < 0.001 for diastolic BP), but the UR-7247 effect was longer lasting. In vivo, no significant difference was observed between 10 mg UR-7247 and 100 mg losartan 4 h after drug intake, but in vitro, the blockade achieved with 100 mg losartan was higher than that seen with UR-7247. Finally, the results confirm that UR-7247 has a very long plasma elimination half-life, which may be due to a high but also tight binding to protein binding sites. In conclusion, UR-7247 is a long-lasting, well-tolerated AT1 receptor in healthy subjects.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Cavernomas after radiotherapy, developing in irradiated children treated for malignant brain tumors, are capillary malformations that are frquently asymptomatic and benign in their evolution. However, in some children this can lead to haemorrhage, which can cause symptoms and need a surgical intervention. Although there is increasing evidence of cavernoma as a possible long term sequelae after radiotherapy, there is still information needed concerning very long follow-up. Different groups studied this problem focusing on incidence and the lag time radiotherapy and the appearance of cavernomas. Results showed that the period can last a long time and the cumulative incidence increases over the years, but the numbers vary between the different publications. More recently researchers tried to compare several predictive factors with the incidence of cavernomas, such as age at radiotherapy, gender, kind of cancer and chemotherapy. No relation has been recorded except a growing incidence when the radiotherapy was started before the age of ten. Reason of the study : The observations reported until now comprised a very heterogenous cohort of patients. No study has ever been made with patients affected only by malignant brain tumors which are typical in a children. As for the studied predictive factors, no publication described the technical aspect of radiotherapy. Objectives: To study a population of pediatric patients children with only malignant brain tumors in order tp calculate the incidence of cavernomas after radiotherapy and their evolution over a longer period compared to so far published researches. To analyse known predictive factors such as age of children at the moment of the radiotherapy, gender, and kind of cancer. To study extensively the role technical aspects of radiotherapy in the occurrence of cavernomas. Methodology: Retrospective study of a group of 62 children irradiated at the CHUV (Lausanne, Switzerland) between 1975 and 2010 due to the following malignant brain cancers: medulloblastoma, ependymoma, PNET. The images of IRM post radiotherapy will be analysed by a neuroradiologist and a radiotherapist will interpret the radiotherapy data. Expected results: We expect to find relations between the incidence of cavernomas post radiotherapy and the predictive factors including different techniques of radiotherapy and consequently to define the best long-term follow up of the children at risk.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Assessment of locomotion through simple tests such as timed up and go (TUG) or walking trials can provide valuable information for the evaluation of treatment and the early diagnosis of people with Parkinson's disease (PD). Common methods used in clinics are either based on complex motion laboratory settings or simple timing outcomes using stop watches. The goal of this paper is to present an innovative technology based on wearable sensors on-shoe and processing algorithm, which provides outcome measures characterizing PD motor symptoms during TUG and gait tests. Our results on ten PD patients and ten age-matched elderly subjects indicate an accuracy ± precision of 2.8 ± 2.4 cm/s and 1.3 ± 3.0 cm for stride velocity and stride length estimation compared to optical motion capture, with the advantage of being practical to use in home or clinics without any discomfort for the subject. In addition, the use of novel spatio-temporal parameters, including turning, swing width, path length, and their intercycle variability, was also validated and showed interesting tendencies for discriminating patients in ON and OFF states and control subjects.