21 resultados para Altered states of consciousness

em Université de Lausanne, Switzerland


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The serotonin-2A receptor (5-HT(2A)R) has been implicated in the pathogenesis of schizophrenia and related inhibitory gating and behavioral inhibition deficits of schizophrenia patients. The hallucinogen psilocybin disrupts automatic forms of sensorimotor gating and response inhibition in humans, but it is unclear so far whether the 5-HT(2A)R or 5-HT(1A)R agonist properties of its bioactive metabolite psilocin account for these effects. Thus, we investigated whether psilocybin-induced deficits in automatic and controlled inhibition in healthy humans could be attenuated by the 5-HT(2A/2C)R antagonist ketanserin. A total of 16 healthy participants received placebo, ketanserin (40 mg p.o.), psilocybin (260 μg/kg p.o.), or psilocybin plus ketanserin in a double-blind, randomized, and counterbalanced order. Sensorimotor gating was measured by prepulse inhibition (PPI) of the acoustic startle response. The effects on psychopathological core dimensions and behavioral inhibition were assessed by the altered states of consciousness questionnaire (5D-ASC), and the Color-Word Stroop Test. Psilocybin decreased PPI at short lead intervals (30 ms), increased all 5D-ASC scores, and selectively increased errors in the interference condition of the Stroop Test. Stroop interference and Stroop effect of the response latencies were increased under psilocybin as well. Psilocybin-induced alterations were attenuated by ketanserin pretreatment, whereas ketanserin alone had no significant effects. These findings suggest that the disrupting effects of psilocybin on automatic and controlled inhibition processes are attributable to 5-HT(2A)R stimulation. Sensorimotor gating and attentional control deficits of schizophrenia patients might be due to changes within the 5-HT(2A)R system.

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INTRODUCTION: Interest in studying swallowing disorders in patients with altered consciousness has increased over the past decade. Swallowing deficit is frequently encountered in severe brain-injured patients. STATE OF ART: Results of studies have highlighted different factors such as the delay between the injury and the treatment and the level of consciousness of these patients, as well as the presence or not of tracheotomy, which will determine the feasibility of resuming oral feeding. Nowadays, very few valid and sensitive scales can be used to assess swallowing deficit in patients with disorders of consciousness. The Facial Oral Tract Therapy (FOTT) scale is an inter-professional multidisciplinary approach offering a structured way to evaluate and treat patients with swallowing disorders. In contrast with other scales, patients do not have to follow verbal instructions for the FOTT. PERSPECTIVES: This paper presents a review of existing literature on the assessment and management of swallowing disorders in patients with altered state of consciousness, and a description of the FOTT method. CONCLUSION: The FOTT seems to be an interesting assessment and rehabilitation tool for patients with disorders of consciousness. However, clinical studies are needed to confirm the validity and sensitivity of this technique.

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Barrett's esophagus (BE) is an acquired condition in which the normal lining of the esophagus is replaced by intestinal metaplastic epithelium. BE can evolve to esophageal adenocarcinoma (EAC) through low-grade dysplasia (LGD) and high-grade dysplasia (HGD). The only generally accepted marker for increased risk of EAC is the presence of HGD, diagnosed on endoscopic biopsies. More specific markers for the prediction of EAC risk are needed. A tissue microarray was constructed comprising tissue samples from BE, LGD, HGD, and EAC. Marker expression was studied by immunohistochemistry using antibodies against CD44, DKK1, CDX2, COX2, SOX9, OCT1, E-cadherin, and beta-catenin. Immunostaining was evaluated semi-quantitatively. CD44 expression decreased in HGD and EAC relative to BE and LGD. DKK1 expression increased in HGD and EAC relative to BE and LDG. CDX2 expression increased in HGD but decreased in EAC. COX2 expression decreased in EAC, and SOX9 expression increased only in the upper crypt epithelial cells in HGD. E-cadherin expression decreased in EAC. Nuclear beta-catenin was not significantly different between BE, LGD, and HGD. Loss of CD44 and gain of DKK1 expression characterizes progression from BE and LGD to HGD and EAC, and their altered expression might indicate an increased risk for developing an EAC. This observation warrants inclusion of these immunohistochemically detectable markers in a study with a long patient follow-up.

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In Saccharomyces cerevisiae, efficient silencer function requires telomere proximity, i.e. compartments of the nucleoplasm enriched in silencing factors. Accordingly, silencers located far from telomeres function inefficiently. We show here that cells lacking yKu balance between two mitotically stable states of silencing competence. In one, a partial delocalization of telomeres and silencing factors throughout the nucleoplasm correlates with enhanced silencing at a non-telomeric locus, while in the other, telomeres retain their focal pattern of distribution and there is no repression at the non-telomeric locus, as observed in wild-type cells. The two states also differ in their level of residual telomeric silencing. These findings indicate the existence of a yKu-independent pathway of telomere clustering and Sir localization. Interestingly, this pathway appears to be under epigenetic control.

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Peripheral nerve hyperexcitability (PNH) is one of the distal peripheral neuropathy phenotypes often present in patients affected by type 2 diabetes mellitus (T2DM). Through in vivo and ex vivo electrophysiological recordings in db/db mice, a model of T2DM, we observed that, in addition to reduced nerve conduction velocity, db/db mice also develop PNH. By using pharmacological inhibitors, we demonstrated that the PNH is mediated by the decreased activity of K(v)1-channels. In agreement with these data, we observed that the diabetic condition led to a reduced presence of the K(v)1.2-subunits in juxtaparanodal regions of peripheral nerves in db/db mice and in nerve biopsies from T2DM patients. Together, these observations indicate that the T2DM condition leads to potassium channel-mediated PNH, thus identifying them as a potential drug target to treat some of the DPN related symptoms.

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BACKGROUND: Recanalization in acute ischemic stroke with large-vessel occlusion is a potent indicator of good clinical outcome. OBJECTIVE: To identify easily available clinical and radiologic variables predicting recanalization at various occlusion sites. METHODS: All consecutive, acute stroke patients from the Acute STroke Registry and Analysis of Lausanne (2003-2011) who had a large-vessel occlusion on computed tomographic angiography (CTA) (< 12 h) were included. Recanalization status was assessed at 24 h (range: 12-48 h) with CTA, magnetic resonance angiography, or ultrasonography. Complete and partial recanalization (corresponding to the modified Treatment in Cerebral Ischemia scale 2-3) were grouped together. Patients were categorized according to occlusion site and treatment modality. RESULTS: Among 439 patients, 51% (224) showed complete or partial recanalization. In multivariate analysis, recanalization of any occlusion site was most strongly associated with endovascular treatment, including bridging therapy (odds ratio [OR] 7.1, 95% confidence interval [CI] 2.2-23.2), and less so with intravenous thrombolysis (OR 1.6, 95% CI 1.0-2.6) and recanalization treatments performed beyond guidelines (OR 2.6, 95% CI 1.2-5.7). Clot location (large vs. intermediate) and tandem pathology (the combination of intracranial occlusion and symptomatic extracranial stenosis) were other variables discriminating between recanalizers and non-recanalizers. For patients with intracranial occlusions, the variables significantly associated with recanalization after 24 h were: baseline National Institutes of Health Stroke Scale (NIHSS) (OR 1.04, 95% CI 1.02-1.1), Alberta Stroke Program Early CT Score (ASPECTS) on initial computed tomography (OR 1.2, 95% CI 1.1-1.3), and an altered level of consciousness (OR 0.2, 95% CI 0.1-0.5). CONCLUSIONS: Acute endovascular treatment is the single most important factor promoting recanalization in acute ischemic stroke. The presence of extracranial vessel stenosis or occlusion decreases recanalization rates. In patients with intracranial occlusions, higher NIHSS score and ASPECTS and normal vigilance facilitate recanalization. Clinical use of these predictors could influence recanalization strategies in individual patients.

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Purpose: In this study, we investigated the expression of the gene encoding beta-galactosidase (Glb)-1-like protein 3 (Glb1l3), a member of the glycosyl hydrolase 35 family, during retinal degeneration in the retinal pigment epithelium (RPE)-specific 65-kDa protein knockout (Rpe65(-/-)) mouse model of Leber congenital amaurosis (LCA). Additionally, we assessed the expression of the other members of this protein family, including beta-galactosidase-1 (Glb1), beta-galactosidase-1-like (Glb1l), and beta-galactosidase-1-like protein 2 (Glb1l2).Methods: The structural features of Glb1l3 were assessed using bioinformatic tools. mRNA expression of Glb-related genes was investigated by oligonucleotide microarray, real-time PCR, and reverse transcription (RT) -PCR. The localized expression of Glb1l3 was assessed by combined in situ hybridization and immunohistochemistry.Results: Glb1l3 was the only Glb-related member strongly downregulated in Rpe65(-/-) retinas before the onset and during progression of the disease. Glb1l3 mRNA was only expressed in the retinal layers and the RPE/choroid. The other Glb-related genes were ubiquitously expressed in different ocular tissues, including the cornea and lens. In the healthy retina, expression of Glb1l3 was strongly induced during postnatal retinal development; age-related increased expression persisted during adulthood and aging.Conclusions: These data highlight early-onset downregulation of Glb1l3 in Rpe65-related disease. They further indicate that impaired expression of Glb1l3 is mostly due to the absence of the chromophore 11-cis retinal, suggesting that Rpe65 deficiency may have many metabolic consequences in the underlying neuroretina.

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A 69-year-old man presented with a sudden headache followed by unconsciousness. There was no head injury. The Glasgow Coma Scale (GCS) score was 3/15 and there was a left mydriasis, unreactive to light. The CT-scan showed a left acute subdural haematoma causing a remarkable mass effect. A supratentorial hemispheric craniotomy was performed. Nevertheless, after several weeks at the intensive care unit (ICU), the patient was still unresponsive to external stimuli and did not show any motor activity. A comfort care attitude was decided on with the family and the patient was extubated. However, a few days later, the patient subsequently showed a surprisingly favourable course, with improved wakefulness. Indeed, the GCS score improved, and the treatment plan was modified so that the patient benefited from rehabilitation. The MRI showed a right cerebral peduncle lesion, consistent with a Kernohan-Woltman notch phenomenon (KWNP). Six months later, the patient was able to walk and live quite normally.

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Purpose. To investigate the role of the myocyte enhancer factor 2 (Mef2) transcription factor family in retinal diseases, Mef2c expression was assessed during retinal degeneration in the Rpe65(-/-) mouse model of Leber's congenital amaurosis (LCA). Mef2c-dependent expression of photoreceptor-specific genes was further addressed. Methods. Expression of Mef2 members was analyzed by oligonucleotide microarray, quantitative PCR (qPCR) and in situ hybridization. Mef2c-dependent transcriptional activity was assayed by luciferase assay in HEK293T cells. Results. Mef2c was the only Mef2 member markedly downregulated during retinal degeneration in Rpe65(-/-) mice. Mef2c mRNA level was decreased by more than 2 fold at 2 and 4 months and by 3.5 fold at 6 months in retinas of Rpe65(-/-) mice. Downregulation of Mef2c at the protein level was confirmed in Rpe65(-/-) retinas. The decrease in Mef2c mRNA levels in the developing Rpe65(-/-) retinas, from post-natal day (P)13 onward, was concomitant with the decreased expression of the rod-specific transcription factors Nrl and Nr2e3. Nrl was further shown to drive Mef2c transcriptional activity, supporting a physiological role for Mef2c in the retina. In addition, Mef2c appeared to act as a transcriptional repressor of its own expression, as well as those of the retina-specific retinal G-protein coupled receptor (Rgr), rhodopsin and M-opsin genes. Conclusions. These findings highlight the early altered regulation of the rod-specific transcriptional network in Rpe65-related disease. They further indicate that Mef2c may act as a novel transcription factor involved in the development and the maintenance of photoreceptor cells.

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Non-infarcted myocardium after coronary occlusion undergoes progressive morphological and functional changes. The purpose of this study was to determine whether non-infarcted myocardium exhibits (1) alteration of the substrate pattern of myocardial metabolism and (2) concomitant changes in the expression of regulatory proteins of glucose and fatty acid metabolism. Myocardial infarction was induced in rats by ligation of the left coronary artery. One day and eight weeks after coronary occlusion, glucose and palmitate oxidation were measured. Expression of selected proteins of metabolism were determined one day to 12 weeks after infarction. One day after coronary occlusion no difference of glucose and palmitate oxidation was detectable, whereas after eight weeks, glucose oxidation was increased (+84%, P<0.05) and palmitate oxidation did not change significantly (-19%, P=0.07) in infarct-containing hearts, compared with hearts from sham-operated rats. One day after coronary occlusion, myocardial mRNA expression of the glucose transporter GLUT-1 was increased (+86%, P<0.05) and the expression of GLUT-4 was decreased (-28%, P<0.05) in surviving myocardium of infarct-containing hearts. Protein level of GLUT-1 was increased (+81%, P<0.05) and that of GLUT-4 slightly, but not significantly, decreased (-16%, P=NS). mRNA expressions of heart fatty acid binding protein (H-FABP), and of medium chain acyl-CoA dehydrogenase (MCAD), were decreased by 36% (P<0.05) and 35% (P=0. 07), respectively. Eight weeks after acute infarction, the left ventricle was hypertrophied and, at this time-point, there was no difference in the expression of GLUT-1 and GLUT-4 between infarcted and sham-operated hearts. However, myocardial mRNA and protein content of MCAD were decreased by 30% (P<0.01) and 27% (P<0.05), respectively. In summary, in surviving myocardium, glucose oxidation was increased eight weeks after coronary occlusion. Concomitantly, mRNA and protein expression of MCAD were decreased, compatible with a role of altered expression of regulatory proteins of metabolism in post-infarction modification of myocardial metabolism.

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Diagnosis and decisions on life-sustaining treatment (LST) in disorders of consciousness, such as the vegetative state (VS) and the minimally conscious state (MCS), are challenging for neurologists. The locked-in syndrome (LiS) is sometimes confounded with these disorders by less experienced physicians. We aimed to investigate (1) the application of diagnostic knowledge, (2) attitudes concerning limitations of LST, and (3) further challenging aspects in the care of patients. A vignette-based online survey with a randomized presentation of a VS, MCS, or LiS case scenario was conducted among members of the German Society for Neurology. A sample of 503 neurologists participated (response rate 16.4%). An accurate diagnosis was given by 86% of the participants. The LiS case was diagnosed more accurately (94%) than the VS case (79%) and the MCS case (87%, p < 0.001). Limiting LST for the patient was considered by 92, 91, and 84% of the participants who accurately diagnosed the VS, LiS, and MCS case (p = 0.09). Overall, most participants agreed with limiting cardiopulmonary resuscitation; a minority considered limiting artificial nutrition and hydration. Neurologists regarded the estimation of the prognosis and determination of the patients' wishes as most challenging. The majority of German neurologists accurately applied the diagnostic categories VS, MCS, and LiS to case vignettes. Their attitudes were mostly in favor of limiting life-sustaining treatment and slightly differed for MCS as compared to VS and LiS. Attitudes toward LST strongly differed according to circumstances (e.g., patient's will opposed treatment) and treatment measures.

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PURPOSE: The primary objective of this study was to describe the frequency of behaviors observed during rest, a non-nociceptive procedure, and a nociceptive procedure in brain-injured intensive care unit (ICU) patients with different levels of consciousness (LOC). Second, it examined the inter-rater reliability and discriminant and concurrent validity of the behavioral checklist used. METHODS: The non-nociceptive procedure involved calling the patient and shaking his/her shoulder. The nociceptive procedure involved turning the patient. The frequency of behaviors was recorded using a behavioral checklist. RESULTS: Patients with absence of movement, or stereotyped flexion or extension responses to a nociceptive stimulus displayed more behaviors during turning (median 5.5, range 0-14) than patients with localized responses (median 4, range 0-10) or able to self-report their pain (median 4, range 0-10). Face flushing, clenched teeth, clenched fist, and tremor were more frequent in patients with absence of movement, or stereotyped responses to a nociceptive stimulus. The reliability of the checklist was supported by a high intra-class correlation coefficient (0.77-0.92), and the internal consistency was acceptable in all three groups (KR 20, 0.71-0.85). Discriminant validity was supported as significantly more behaviors were observed during nociceptive stimulation than at rest. Concurrent validity was confirmed as checklist scores were correlated to the patients' self-reports of pain (r s = 0.53; 95 % CI 0.21-0.75). CONCLUSION: Brain-injured patients reacted significantly more during a nociceptive stimulus and the number of observed behaviors was higher in patients with a stereotyped response.

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Medial prefrontal cortical areas have been hypothesized to underlie altered contextual processing in posttraumatic stress disorder (PTSD). We investigated brain signaling of contextual information in this disorder. Eighteen PTSD subjects and 16 healthy trauma-exposed subjects underwent a two-day fear conditioning and extinction paradigm. On day 1, within visual context A, a conditioned stimulus (CS) was followed 60% of the time by an electric shock (conditioning). The conditioned response was then extinguished (extinction learning) in context B. On day 2, recall of the extinction memory was tested in context B. Skin conductance response (SCR) and functional magnetic resonance imaging (fMRI) data were collected during context presentations. There were no SCR group differences in any context presentation. Concerning fMRI data, during late conditioning, when context A signaled danger, PTSD subjects showed dorsal anterior cingulate cortical (dACC) hyperactivation. During early extinction, when context B had not yet fully acquired signal value for safety, PTSD subjects still showed dACC hyperactivation. During late extinction, when context B had come to signal safety, they showed ventromedial prefrontal cortex (vmPFC) hypoactivation. During early extinction recall, when context B signaled safety, they showed both vmPFC hypoactivation and dACC hyperactivation. These findings suggest that PTSD subjects show alterations in the processing of contextual information related to danger and safety. This impairment is manifest even prior to a physiologically-measured, cue-elicited fear response, and characterized by hypoactivation in vmPFC and hyperactivation in dACC.

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BACKGROUND AND PURPOSE: Needs of patients dying from stroke are poorly investigated. We aim to assess symptoms of these patients referred to a palliative care consult team, and to review their treatment strategies. METHODS: All charts of patients dying from stroke in a tertiary hospital, and referred consecutively to a palliative care consultant team from 2000 to 2005, were reviewed retrospectively. Symptoms, ability to communicate, treatments, circumstances and causes of death were collected. RESULTS: Forty-two patients were identified. Median NIH Stroke Scale on admission was 21. The most prevalent symptoms were dyspnoea (81%), and pain (69%). Difficulties or inability to communicate because of aphasia or altered level of consciousness were present in 93% of patients. Pharmacological respiratory treatments consisted of anti-muscarinic drugs (52%), and opioids (33%). Pain was mainly treated by opioids (69%). During the last 48 h of life, 81% of patients were free of pain and 48% of respiratory distress. The main causes of death were neurological complications in 38% of patients, multiple medical complications in 36%, and specific medical causes in 26%. CONCLUSIONS: Patients dying from stroke and referred to a palliative care consult team have multiple symptoms, mainly dyspnoea and pain. Studies are warranted to develop specific symptoms assessment tools in non-verbal stroke patients, to accurately assess patients' needs, and to measure effectiveness of palliative treatments.