947 resultados para non-normal space
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Purpose: Pretargeted radioimmunotherapy (PRIT) using streptavidin (SAv)-biotin technology can deliver higher therapeutic doses of radioactivity to tumors than conventional RIT. However, "endogenous" biotin can interfere with the effectiveness of this approach by blocking binding of radiolabeled biotin to SAv. We engineered a series of SAv FPs that downmodulate the affinity of SAv for biotin, while retaining high avidity for divalent DOTA-bis-biotin to circumvent this problem.Experimental Design: The single-chain variable region gene of the murine 1F5 anti-CD20 antibody was fused to the wild-type (WT) SAv gene and to mutant SAv genes, Y43A-SAv and S45A-SAv. FPs were expressed, purified, and compared in studies using athymic mice bearing Ramos lymphoma xenografts.Results: Biodistribution studies showed delivery of more radioactivity to tumors of mice pretargeted with mutant SAv FPs followed by (111)In-DOTA-bis-biotin [6.2 +/- 1.7% of the injected dose per gram (%ID/gm) of tumor 24 hours after Y43A-SAv FP and 5.6 +/- 2.2%ID/g with S45A-SAv FP] than in mice on normal diets pretargeted with WT-SAv FP (2.5 +/- 1.6%ID/g; P = 0.01). These superior biodistributions translated into superior antitumor efficacy in mice treated with mutant FPs and (90)Y-DOTA-bis-biotin [tumor volumes after 11 days: 237 +/- 66 mm(3) with Y43A-SAv, 543 +/- 320 mm(3) with S45A-SAv, 1129 +/- 322 mm(3) with WT-SAv, and 1435 +/- 212 mm(3) with control FP (P < 0.0001)].Conclusions: Genetically engineered mutant-SAv FPs and bis-biotin reagents provide an attractive alternative to current SAv-biotin PRIT methods in settings where endogenous biotin levels are high. Clin Cancer Res; 17(23); 7373-82. (C)2011 AACR.
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Résumé du travail de thèse Introduction : Les différentes cellules endothéliales du lit vasculaire ont de nombreuses similitudes fonctionnelles et morphologiques. Cependant, elles présentent également une importante hétérogénéité structurelle et fonctionnelle qui peut avoir des implications notamment dans l'angiogenèse et le développement des maladies cardio-vasculaires. Peu d'études ont été publiées au sujet de l'expression et de la distribution des marqueurs endothéliaux dans les tissus humain normaux. Objectif : Nous avons étudié l'expression immunohistochimique des marqueurs endothéliaux CD31, CD34, vWF et Fli-1 dans les vaisseaux périphériques du rein, du poumon, de la rate, du foie, du cour et des gros vaisseaux ; incluant l'aorte, la veine cave inférieure, l'artère rénale ainsi que les artères et veines pulmonaires et fémorales. Matériel et méthodes : Les échantillons tissulaires ont été obtenus à partir de matériel d'autopsie et de biopsies. Le matériel a été fixé en formaline et inclus en paraffine. Les coupes de paraffine ont été colorées immunohistochimiquement avec CD31, CD34 et vWF. Les biopsies ont également été colorées immunohistochimiquement avec Fli-1, D2-40 et Lyve-1. Résultats : L'expression immunohistochimique de ces marqueurs est hétérogène dans les différents organes étudiés. Dans le rein, l'endothélium fenêtré des glomérules exprime fortement CD31 et CD34. Par contre, il n'exprime pas ou alors de manière faible et focale vWF. Dans le poumon, les capillaires alvéolaires expriment fortement CD31 et CD34 mais sont habituellement négatifs pour le vWF. L'expression de vWF augmente graduellement avec le calibre vasculaire dans le poumon. Les sinusoïdes de la rate expriment CD31 de manière diffuse mais ils n'expriment pas CD34. Les sinusoïdes du foie expriment CD31 de part et d'autre des lobules. Par contre, CD34 est exprimé seulement dans la région périportale. L'expression de Fli-1 dans les cellules endothéliales est ubiquitaire et ne varie pas suivant le type de vaisseau ou d'organe. Fli-1 est également exprimé dans d'autres types de cellules, essentiellement des lymphocytes. D2-40 est exprimé seulement dans l'endothélium des vaisseaux lymphatiques. L'expression de Lyve-1 dans ce matériel de routine était inconstante et non reproductible. Conclusion : Ces résultats indiquent que l'expression des marqueurs endothéliaux CD31, CD34 et vWF est hétérogène dans le lit vasculaire et qu'elle varie entre différents vaisseaux et différents compartiments anatomiques du même organe. D2-40 ne marque que les cellules endothéliales lymphatiques.
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Current hypertension guidelines point to the necessity of achieving sustained and strict blood pressure control in every hypertensive patient. To reach this goal the patient should comply both with hygienic measures and pharmacologic treatment. This remains a difficult task, particularly since hypertension is generally asymptomatic and since any therapeutic intervention might adversely alter the patient's quality of life. Long-term persistence with antihypertensive therapy is facilated when the treatment is initiated with well tolerated antihypertensive agents, especially blockers of the renin-angiotensin system. Having a normal blood pressure during treatment is also an important determinant of persistence. This explains the growing interest for fixed-dose combinations, which have the main advantage to be at the same time efficient and well tolerated. These simple to use preparations have even gained acceptance as first-line drug regimen.
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In this paper we present a Bayesian image reconstruction algorithm with entropy prior (FMAPE) that uses a space-variant hyperparameter. The spatial variation of the hyperparameter allows different degrees of resolution in areas of different statistical characteristics, thus avoiding the large residuals resulting from algorithms that use a constant hyperparameter. In the first implementation of the algorithm, we begin by segmenting a Maximum Likelihood Estimator (MLE) reconstruction. The segmentation method is based on using a wavelet decomposition and a self-organizing neural network. The result is a predetermined number of extended regions plus a small region for each star or bright object. To assign a different value of the hyperparameter to each extended region and star, we use either feasibility tests or cross-validation methods. Once the set of hyperparameters is obtained, we carried out the final Bayesian reconstruction, leading to a reconstruction with decreased bias and excellent visual characteristics. The method has been applied to data from the non-refurbished Hubble Space Telescope. The method can be also applied to ground-based images.
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The inadequacies and obsolescence of Eurocentric theories based on a binaryand static worldview have become a staple topic of postcolonial studies, and tosome extent also of translation studies. Nonetheless, the literary texts that arecalled upon in order to show the dynamism and hybridity of (post)modern worksbelong for the most part to the languages of the former colonial powers, especiallyEnglish, and remain inserted in a system that construes literatures interms of opposition. As a consequence, there is outside India a doubly misleadingunderstanding of Indian literatures other than those written in English:firstly, that translations of works in Hindi and in the Indian bhāṣā seem to belacking, if not inexistent, and secondly, that these "minor" literatures - as theyare regularly termed - are still often viewed as being highly dependent on theidea of "tradition," in opposition to the "postmodern" hybridity of the literatureswritten in the "dominant" languages, such as English or French. Againstthese views and supported by the analysis of Ajñeya's works in Hindi togetherwith their English translations, this paper aims to show: 1) that translationsfrom Hindi, which are not in fact non-existent, are mainly carried out in India,and 2) that Ajñeya's works, while representing a significant instance of the effectivehybridity present in Indian literatures, help to illustrate the moving spaceof translation. This demonstration effectively invalidates the above-mentionedoppositional standpoint.
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Body mass index (BMI) is related with cardiorespiratory fitness (CRF), but less is known regarding the combined relationships between BMI and body fat (BF) on CRF. Cross-sectional study included 2361 girls and 2328 boys aged 10–18 years living in the area of Lisbon, Portugal. BMI was calculated by measuring height and weight, and obesity was assessed by international criteria. BF was assessed by bioimpedance. CRF was assessed by the 20-m shuttle run and the participants were classified as normal-to-high or low-CRF level according to Fitness gram criterion-referenced standards. The prevalence of low CRF was 47 and 39% in girls and boys, respectively. The corresponding values for the prevalence of obesity were 4.8 and 5.6% (not significant) and of excess BF of 12.1 and 25.1% (P <0.001), respectively. In both sexes, BMI and BF were inversely related with CRF: r = – 0.53 and – 0.45 for BMI and % BF, respectively, in boys and the corresponding values in girls were – 0.50 and – 0.33 (all P <0.01). When compared with a participant with normal BMI and BF, the odds ratios (95% confidence interval) for low CRF were 1.94 (1.46–2.58) for a participant with normal BMI and high BF, and 6.19 (5.02–7.63) for a participant with high BMI and high BF. The prevalence of low-CRF levels is high in Portuguese youths. BF negatively influences CRF levels among children/adolescents with normal BMI.
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Isolated ventricular non-compaction (IVNC) is a rare, congenital, unclassified cardiomyopathy characterized by prominent trabecular meshwork and deep recesses. Major clinical manifestations of IVNC are heart failure, atrial and ventricular arrhythmias, and thrombo-embolic events. We describe a case of a 69-year-old woman in whom the diagnosis of IVNC was discovered late, whereas former echocardiographic examinations were considered normal. She was known for systolic left ventricular dysfunction for 3 years and then became symptomatic (NYHA III). In the past, she suffered from multiple episodes of deep vein thrombosis and pulmonary embolism. Electrocardiogram revealed a wide QRS complex, and transthoracic echocardiography showed typical apical thickening of the left and right ventricular myocardial wall with two distinct layers. The ratio of non-compacted to compacted myocardium was >2:1. Cardiac MRI confirmed the echocardiographic images. Cerebral MRI revealed multiple ischaemic sequellae. In view of the persistent refractory, heart failure in medical treatment of patients with classical criteria for cardiac re-synchronization therapy, as well as the ventricular arrhythmias, a biventricular automatic intracardiac defibrillator (biventricular ICD) was implanted. The 2-year follow-up period was characterized by improvement of NYHA functional class from III to I and increasing in left ventricular function. We hereby present a case of IVNC with favourable outcome after biventricular ICD implantation. Cardiac re-synchronization therapy could be considered in the management of this pathology.
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OBJECTIVES: Our objective is to test the hypothesis that coronary endothelial function (CorEndoFx) does not change with repeated isometric handgrip (IHG) stress in CAD patients or healthy subjects. BACKGROUND: Coronary responses to endothelial-dependent stressors are important measures of vascular risk that can change in response to environmental stimuli or pharmacologic interventions. The evaluation of the effect of an acute intervention on endothelial response is only valid if the measurement does not change significantly in the short term under normal conditions. Using 3.0 Tesla (T) MRI, we non-invasively compared two coronary artery endothelial function measurements separated by a ten minute interval in healthy subjects and patients with coronary artery disease (CAD). METHODS: Twenty healthy adult subjects and 12 CAD patients were studied on a commercial 3.0 T whole-body MR imaging system. Coronary cross-sectional area (CSA), peak diastolic coronary flow velocity (PDFV) and blood-flow were quantified before and during continuous IHG stress, an endothelial-dependent stressor. The IHG exercise with imaging was repeated after a 10 minute recovery period. RESULTS: In healthy adults, coronary artery CSA changes and blood-flow increases did not differ between the first and second stresses (mean % change ±SEM, first vs. second stress CSA: 14.8%±3.3% vs. 17.8%±3.6%, p = 0.24; PDFV: 27.5%±4.9% vs. 24.2%±4.5%, p = 0.54; blood-flow: 44.3%±8.3 vs. 44.8%±8.1, p = 0.84). The coronary vasoreactive responses in the CAD patients also did not differ between the first and second stresses (mean % change ±SEM, first stress vs. second stress: CSA: -6.4%±2.0% vs. -5.0%±2.4%, p = 0.22; PDFV: -4.0%±4.6% vs. -4.2%±5.3%, p = 0.83; blood-flow: -9.7%±5.1% vs. -8.7%±6.3%, p = 0.38). CONCLUSION: MRI measures of CorEndoFx are unchanged during repeated isometric handgrip exercise tests in CAD patients and healthy adults. These findings demonstrate the repeatability of noninvasive 3T MRI assessment of CorEndoFx and support its use in future studies designed to determine the effects of acute interventions on coronary vasoreactivity.
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We evaluated the effectiveness of supplementation with high dose of oral vitamin D3 to correct vitamin D insufficiency. We have shown that one or two oral bolus of 300,000 IU of vitamin D3 can correct vitamin D insufficiency in 50% of patients and that the patients who benefited more from supplementation were those with the lowest baseline levels. INTRODUCTION: Adherence with daily oral supplements of vitamin D3 is suboptimal. We evaluated the effectiveness of a single high dose of oral vitamin D3 (300,000 IU) to correct vitamin D insufficiency in a rheumatologic population. METHODS: Over 1 month, 292 patients had levels of 25-OH vitamin D determined. Results were classified as: deficiency <10 ng/ml, insufficiency ≥10 to 30 ng/ml, and normal ≥30 ng/ml. We added a category using the IOM recommended cut-off of 20 ng/ml. Patients with deficient or normal levels were excluded, as well as patients already supplemented with vitamin D3. Selected patients (141) with vitamin D insufficiency (18.5 ng/ml (10.2-29.1) received a prescription for 300,000 IU of oral vitamin D3 and were asked to return after 3 (M3) and 6 months (M6). Patients still insufficient at M3 received a second prescription for 300,000 IU of oral vitamin D3. Relation between changes in 25-OH vitamin D between M3 and M0 and baseline values were assessed. RESULTS: Patients (124) had a blood test at M3. Two (2%) had deficiency (8.1 ng/ml (7.5-8.7)) and 50 (40%) normal results (36.7 ng/ml (30.5-5.5)). Seventy-two (58%) were insufficient (23.6 ng/ml (13.8-29.8)) and received a second prescription for 300,000 IU of oral vitamin D3. Of the 50/124 patients who had normal results at M3 and did not receive a second prescription, 36 (72%) had a test at M6. Seventeen (47%) had normal results (34.8 ng/ml (30.3-42.8)) and 19 (53%) were insufficient (25.6 ng/ml (15.2-29.9)). Of the 72/124 patients who receive a second prescription, 54 (75%) had a test at M6. Twenty-eight (52%) had insufficiency (23.2 ng/ml (12.8-28.7)) and 26 (48%) had normal results (33.8 ng/ml (30.0-43.7)). At M3, 84% patients achieved a 25-OH vitamin D level >20 ng/ml. The lowest the baseline value, the highest the change after 3 months (negative relation with a correlation coefficient r = -0.3, p = 0.0007). CONCLUSIONS: We have shown that one or two oral bolus of 300,000 IU of vitamin D3 can correct vitamin D insufficiency in 50% of patients.
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Aim: Diffusion weighted magnetic resonance imaging (MRI) is now widely used in human brain diagnosis.1 To date molecular mechanisms underlying changes in Apparent Diffusion Coefficient (ADC) signals remain poorly understood. AQP4, localized to astrocytes, is one of the most highly expressed cerebral AQPs.2 AQP4 is involved in water movement within the cell membrane of cultured astrocytes.3 We hypothesize that AQP4 contributes to water diffusion and underlying ADC values in normal brain. Methods: We used an RNA interference (RNAi) protocol in vivo, to acutely knockdown expression of AQP4 in rat brain and to determine whether this was associated with changes in brain ADC values using MRI protocols as previously described.4 RNAi was performed using specific small interference RNA (siRNA) against AQP4 (siAQP4) and a non-targeted-siRNA (siGLO) as a control. The specificity and efficiency of the siAQP4 were first tested in vitro in astrocyte and hippocampal slice cultures. In vivo, siRNAs were injected into the rat cortex 3d prior to MRI acquisition and AQP4 was assessed by western blot (n=4) and immunohistochemistry (n=6). Histology was performed on adjacent slices. Results: siAQP4 application on primary astrocyte cultures induced a 76% decrease in AQP4 expression after 4 days. In hippocampal slice cultures; we also found a significant decrease in AQP4 expression in astrocytes after siAQP4. In vivo, injection of non-targeted siRNA (siGLO) tagged with CY3 allowed us to show that GFAP positive cells (astrocytes) were positively stained with CY3-siGLO, showing efficient transfection. Western blot and immunohistochemical analysis showed that siAQP4 induced a ~30% decrease in AQP4 expression without modification of tissue properties or cell death. After siAQP4 treatment, a significant decrease in ADC values (~50%) were observed without altered of T2 values. Conclusions: Together these results suggest that AQP4 reduces water diffusion through the astrocytic plasma membrane and decreases ADC values. Our findings demonstrate for the first time that astrocytic AQP4 contributes significantly to brain water diffusion and ADC values in normal brain. These results open new avenues to interpretation of ADC values under normal physiological conditions and in acute and chronic brain injuries.
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In Einstein-Maxwell theory, magnetic flux lines are "expelled" from a black hole as extremality is approached, in the sense that the component of the field strength normal to the horizon goes to zero. Thus, extremal black holes are found to exhibit the sort of ¿Meissner effect¿ which is characteristic of superconducting media. We review some of the evidence for this effect and present new evidence for it using recently found black hole solutions in string theory and Kaluza-Klein theory. We also present some new solutions, which arise naturally in string theory, which are non-superconducting extremal black holes. We present a nice geometrical interpretation of these effects derived by looking carefully at the higher dimensional configurations from which the lower dimensional black hole solutions are obtained. We show that other extremal solitonic objects in string theory (such as p-branes) can also display superconducting properties. In particular, we argue that the relativistic London equation will hold on the world volume of ¿light¿ superconducting p-branes (which are embedded in flat space), and that minimally coupled zero modes will propagate in the adS factor of the near-horizon geometries of "heavy," or gravitating, superconducting p-branes.
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Exact solutions to FokkerPlanck equations with nonlinear drift are considered. Applications of these exact solutions for concrete models are studied. We arrive at the conclusion that for certain drifts we obtain divergent moments (and infinite relaxation time) if the diffusion process can be extended without any obstacle to the whole space. But if we introduce a potential barrier that limits the diffusion process, moments converge with a finite relaxation time.
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The rationale of this study was to investigate molecular flexibility and its influence on physicochemical properties with a view to uncovering additional information on the fuzzy concept of dynamic molecular structure. Indeed, it is now known that computed molecular interaction fields (MIFs) such as molecular electrostatic potentials (MEPs) and lipophilicity potentials (MLPs) are conformation-dependent, as are dipole moments. A database of 125 compounds was used whose conformational space was explored, while conformation-dependent parameters were computed for each non-redundant conformer found in the conformational space of the compounds. These parameters were the virtual log P (log P(MLP), calculated by a MLP approach), the apolar surface area (ASA), polar surface area (PSA), and solvent-accessible surface (SAS). For each compound, the range taken by each parameter (its property space) was divided by the number of rotors taken as an index of flexibility, yielding a parameter termed 'molecular sensitivity'. This parameter was poorly correlated with others (i.e., it contains novel information) and showed the compounds to fall into two broad classes. 'Sensitive' molecules are those whose computed property ranges are markedly sensitive to conformational effects, whereas 'insensitive' (in fact, less sensitive) molecules have property ranges which are comparatively less affected by conformational fluctuations. A pharmacokinetic application is presented.
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The morphology and distribution of local-circuit neurons (interneurons) were examined, by calbindin D-28k and parvalbumin immunocytochemistry, in the frontal cortex (area 8) in two patients with frontal lobe dementia of non-Alzheimer type associated with classical amyotrophic lateral sclerosis (ALS), and in seven normal cases. The density of calbindin D-28k immunoreactive cells was dramatically reduced in ALS patients, but the density of parvalbumin-immunoreactive neurons was preserved. Decreased density of calbindin D-28k-immunoreactive neurons, which are mainly located in the upper cortical layers, may interfere with the normal processing of cortico-cortical connections, whereas integrity of parvalbumin-immunoreactive cells may be associated with the preservation of the major inhibitory intracortical circuits in patients with frontal lobe dementia.
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Intracranial hypertension is an emergency suspected from clinical symptoms, imaging data and ophthalomologic signs. Intracranial hypertension is confirmed by invasive intracranial monitoring, which is the gold standard technique to measure intracranial pressure (ICP). Because of complications, hemorrhage or infection, non-invasive methods have been developed such as neuroimaging, transcranial Doppler sonography and optic nerve sheath diameter (ONSD) ultrasonography. We have reviewed ONSD technique that detects intracranial hypertension related volume variations of subarachnoid space along the retro bulbar segment of the optic nerve. Technique, indications and prospects are discussed.