898 resultados para White Head Conglomerate


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In humans, action errors and perceptual novelty elicit activity in a shared frontostriatal brain network, allowing them to adapt their ongoing behavior to such unexpected action outcomes. Healthy and pathologic aging reduces the integrity of white matter pathways that connect individual hubs of such networks and can impair the associated cognitive functions. Here, we investigated whether structural disconnection within this network because of small-vessel disease impairs the neural processes that subserve motor slowing after errors and novelty (post-error slowing, PES; post-novel slowing, PNS). Participants with intact frontostriatal circuitry showed increased right-lateralized beta-band (12-24 Hz) synchrony between frontocentral and frontolateral electrode sites in the electroencephalogram after errors and novelty, indexing increased neural communication. Importantly, this synchrony correlated with PES and PNS across participants. Furthermore, such synchrony was reduced in participants with frontostriatal white matter damage, in line with reduced PES and PNS. The results demonstrate that behavioral change after errors and novelty result from coordinated neural activity across a frontostriatal brain network and that such cognitive control is impaired by reduced white matter integrity.

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PURPOSE: To assess the agreement and repeatability of horizontal white-to-white (WTW) and horizontal sulcus-to-sulcus (STS) diameter measurements and use these data in combination with available literature to correct for interdevice bias in preoperative implantable collamer lens (ICL) size selection. DESIGN: Interinstrument reliability and bias assessment study. METHODS: A total of 107 eyes from 56 patients assessed for ICL implantation at our institution were included in the study. This was a consecutive series of all patients with suitable available data. The agreement and bias between WTW (measured with the Pentacam and BioGraph devices) and STS (measured with the HiScan device) were estimated. RESULTS: The mean spherical equivalent was -8.93 ± 5.69 diopters. The BioGraph measures of WTW were wider than those taken with the Pentacam (bias = 0.26 mm, P < .01), and both horizontal WTW measures were wider than the horizontal STS measures (bias >0.91 mm, P < .01). The repeatability (Sr) of STS measured with the HiScan was 0.39 mm, which was significantly reduced (Sr = 0.15 mm) when the average of 2 measures was used. Agreement between the horizontal WTW measures and horizontal STS estimates when bias was accounted for was г = 0.54 with the Pentacam and г = 0.64 with the BioGraph. CONCLUSIONS: Large interdevice bias was observed for WTW and STS measures. STS measures demonstrated poor repeatability, but the average of repeated measures significantly improved repeatability. In order to conform to the US Food and Drug Administration's accepted guidelines for ICL sizing, clinicians should be aware of and account for the inconsistencies between devices.

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The exhibition "Isabel Banal. Via Lactea" is part of the exhibition cycle "Blanc sota negre. Treballs des de l'imperceptible / 5" curated by Joana Masó (Centre Dona i Literatura) and Assumpta Bassas (Universitat de Barcelona). In this exhibition, the artist shows long-term and open projects exhibited on five tables. The table is one of the central elements from the beginning of her career, in relation to the creative and domestic space, but also as a double metaphor for the ground and for soil.

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PURPOSE: This multicenter phase III study evaluated the efficacy and safety of lapatinib, an epidermal growth factor receptor/ErbB2 inhibitor, administered concomitantly with chemoradiotherapy and as maintenance monotherapy in patients with high-risk surgically treated squamous cell carcinoma of the head and neck (SCCHN). PATIENTS AND METHODS: Patients with resected stage II to IVA SCCHN, with a surgical margin ≤ 5 mm and/or extracapsular extension, were randomly assigned to chemoradiotherapy (66 Gy total radiation dose and cisplatin 100 mg/m(2) per day administered on days 1, 22, and 43) plus placebo or lapatinib (1,500 mg per day) before and during chemoradiotherapy, followed by 12 months of maintenance monotherapy. RESULTS: Six hundred eighty-eight patients were enrolled (lapatinib, n = 346; placebo, n = 342). With a median follow-up time of 35.3 months, the study ended early because of the apparent plateauing of disease-free survival (DFS) events. Median DFS assessed by an independent review committee was 53.6 months and not reached for lapatinib and placebo, respectively (hazard ratio, 1.10; 95% CI, 0.85 to 1.43). Investigator-assessed results confirmed the independent review committee assessment. No significant differences in DFS by human papillomavirus status or overall survival were observed between treatment arms. Similar numbers of patients in both treatment arms experienced adverse events (AEs), with more patients in the lapatinib arm than the placebo arm experiencing serious AEs (48% v 40%, respectively). The most commonly observed treatment-related AEs were diarrhea and rash, both predominantly in the lapatinib arm. CONCLUSION: Addition of lapatinib to chemoradiotherapy and its use as long-term maintenance therapy does not offer any efficacy benefits and had additional toxicity compared with placebo in patients with surgically treated high-risk SCCHN.

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Un enregistrement de la tension artérielle ambulatoire (couvrant 24 heures) ainsi que plusieurs mesures en cabinet ont permis de classer chaque participant dans 4 catégories : normotension (tension artérielle normale au cabinet et en ambulatoire), hypertension artérielle soutenue (tension artérielle élevée au cabinet et en ambulatoire), hypertension de la blouse blanche (tension artérielle élevée au cabinet mais normale en ambulatoire) et hypertension artérielle masquée (tension artérielle élevée en ambulatoire mais normale au cabinet). Dans la littérature, la prévalence de l'hypertension artérielle masquée varie entre 8% et 48% selon la méthodologie utilisée et la population étudiée. Les personnes présentant une hypertension artérielle masquée ou une hypertension de la blouse blanche pourraient avoir un risque cardiovasculaire plus élevé que des personnes normotendues. Il est utile de déterminer les facteurs cliniques associés à l'hypertension artérielle masquée et à l'hypertension de la blouse blanche afin d'identifier les personnes à risque de développer ces conditions. Peu d'études ont examiné la proportion et les facteurs associés à l'hypertension artérielle masquée et à l'hypertension de la blouse blanche en Suisse, et aucune étude n'a été faite au niveau populationnel. Dans cette étude, nous investiguons les facteurs associés à l'hypertension masquée et à l'hypertension de la blouse blanche dans une étude populationnelle Suisse. Le Swiss Kidney Project on Genes in Hypertension (SKIPOGH) est une étude familiale transversale. La tension artérielle au cabinet et la tension artérielle ambulatoire sont mesurées par des appareils validés. Dans cette étude, nous avons défini l'hypertension artérielle masquée comme une tension artérielle au cabinet < 140/90 mmHg et une tension ambulatoire (jour) s 135/85 mmHg ; l'hypertension de la blouse blanche comme une tension artérielle au cabinet s 140/90 mmHg et une tension ambulatoire < 135/85 mmHg ; et enfin la tension artérielle à la limite supérieure de la norme au cabinet comme une tension systolique entre 130 et 139 mmHg et/ou une tension artérielle diastolique entre 85 et 89 mmHg lors de la mesure au cabinet. Nous avons utilisé une régression logistique multiple pour examiner la relation entre l'hypertension masquée et l'hypertension de la blouse blanche, d'une part, et les facteurs associés, d'autre part, en prenant en compte les corrélations familiales. Parmi les 652 participants inclus dans cette analyse, 51% sont des femmes. L'âge moyen (± écart type) est de 48 ans (± 18 ans). Les proportions de participants avec une hypertension masquée et une hypertension de la blouse blanche sont de 15.8% et de 2.6% respectivement. L'hypertension masquée est associée à l'âge (odds ratio (OR) = 1.02, p = 0.012), à une tension artérielle au cabinet à la limite supérieure de la norme (OR = 6.68, p, 0.001) et à l'obésité (OR = 3.63, p = 0.001). L'hypertension de la blouse blanche est associée à l'âge (OR = 1.07, p, 0.001) mais pas au niveau d'éducation, à l'anamnése familiale d'hypertension ou à l'activité physique. Nos données suggèrent que les médecins doivent envisager d'effectuer un enregistrement de la tension artérielle ambulatoire chez les personnes âgées avec une tension au cabinet à la limite supérieure de la norme et/ou chez les patients obèses afin de déterminer si ces individus présentent une hypertension artérielle en ambulatoire.

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BACKGROUND: Although the importance of accurate femoral reconstruction to achieve a good functional outcome is well documented, quantitative data on the effects of a displacement of the femoral center of rotation on moment arms are scarce. The purpose of this study was to calculate moment arms after nonanatomical femoral reconstruction. METHODS: Finite element models of 15 patients including the pelvis, the femur, and the gluteal muscles were developed. Moment arms were calculated within the native anatomy and compared to distinct displacement of the femoral center of rotation (leg lengthening of 10 mm, loss of femoral offset of 20%, anteversion ±10°, and fixed anteversion at 15°). Calculations were performed within the range of motion observed during a normal gait cycle. RESULTS: Although with all evaluated displacements of the femoral center of rotation, the abductor moment arm remained positive, some fibers initially contributing to extension became antagonists (flexors) and vice versa. A loss of 20% of femoral offset led to an average decrease of 15% of abductor moment. Femoral lengthening and changes in femoral anteversion (±10°, fixed at 15°) led to minimal changes in abductor moment arms (maximum change of 5%). Native femoral anteversion correlated with the changes in moment arms induced by the 5 variations of reconstruction. CONCLUSION: Accurate reconstruction of offset is important to maintaining abductor moment arms, while changes of femoral rotation had minimal effects. Patients with larger native femoral anteversion appear to be more susceptible to femoral head displacements.

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Abstract Objective: To determine whether low-level laser therapy can prevent salivary hypofunction after radiotherapy and chemotherapy in head and neck cancer patients. Materials and Methods: We evaluated 23 head and neck cancer patients, of whom 13 received laser therapy and 10 received clinical care only. An InGaAlP laser was used intra-orally (at 660 nm and 40 mW) at a mean dose of 10.0 J/cm2 and extra-orally (at 780 nm and 15 mW) at a mean dose of 3.7 J/cm2, three times per week, on alternate days. Stimulated and unstimulated sialometry tests were performed before the first radiotherapy and chemotherapy sessions (N0) and at 30 days after the end of treatment (N30). Results: At N30, the mean salivary flow rates were significantly higher among the laser therapy patients than among the patients who received clinical care only, in the stimulated and unstimulated sialometry tests (p = 0.0131 and p = 0.0143, respectively). Conclusion: Low-level laser therapy, administered concomitantly with radiotherapy and chemotherapy, appears to mitigate treatment-induced salivary hypofunction in patients with head and neck cancer.

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It is often assumed that total head losses in a sand filter are solely due to the filtration media and that there are analytical solutions, such as the Ergun equation, to compute them. However, total head losses are also due to auxiliary elements (inlet and outlet pipes and filter nozzles), which produce undesirable head losses because they increase energy requirements without contributing to the filtration process. In this study, ANSYS Fluent version 6.3, a commercial computational fluid dynamics (CFD) software program, was used to compute head losses in different parts of a sand filter. Six different numerical filter models of varying complexities were used to understand the hydraulic behavior of the several filter elements and their importance in total head losses. The simulation results show that 84.6% of these were caused by the sand bed and 15.4% were due to auxiliary elements (4.4% in the outlet and inlet pipes, and 11.0% in the perforated plate and nozzles). Simulation results with different models show the important role of the nozzles in the hydraulic behavior of the sand filter. The relationship between the passing area through the nozzles and the passing area through the perforated plate is an important design parameter for the reduction of total head losses. A reduced relationship caused by nozzle clogging would disproportionately increase the total head losses in the sand filter

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The knowledge on the optics of fogbows is scarce, and their polarization characteristics have never been measured to our knowledge. To fill this gap we measured the polarization features of 16 fogbows during the Beringia 2005 Arctic polar research expedition by imaging polarimetry in the red, green and blue spectral ranges. We present here the first polarization patterns of the fogbow. In the patterns of the degree of linear polarization p, fogbows and their supernumerary bows are best visible in the red spectral range due to the least dilution of fogbow light by light scattered in air. In the patterns of the angle of polarization α fogbows are practically not discernible because their α-pattern is the same as that of the sky: the direction of polarization is perpendicular to the plane of scattering and is parallel to the arc of the bow, independently of the wavelength. Fogbows and their supernumeraries were best seen in the patterns of the polarized radiance. In these patterns the angular distance δ between the peaks of the primary and the first supernumerary and the angular width σ of the primary bow were determined along different radii from the center of the bow. δ ranged between 6.08° and 13.41° , while σ changed from 5.25° to 19.47° . Certain fogbows were relatively homogeneous, meaning small variations of δ and σ along their bows. Other fogbows were heterogeneous, possessing quite variable δ- and σ-values along their bows. This variability could be a consequence of the characteristics of the high Arctic with open waters within the ice shield resulting in the spatiotemporal change of the droplet size within the fog

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We sometimes vividly remember things that did not happen, a phenomenon with general relevance, not only in the courtroom. It is unclear to what extent individual differences in false memories are driven by anatomical differences in memory-relevant brain regions. Here we show in humans that microstructural properties of different white matter tracts as quantified using diffusion tensor imaging are strongly correlated with true and false memory retrieval. To investigate these hypotheses, we tested a large group of participants in a version of the Deese-Roediger-McDermott paradigm (recall and recognition) and subsequently obtained diffusion tensor images. A voxel-based whole-brain level linear regression analysis was performedto relatefractional anisotropyto indices oftrue andfalse memory recall and recognition. True memory was correlated to diffusion anisotropy in the inferior longitudinal fascicle, the major connective pathway of the medial temporal lobe, whereas a greater proneness to retrieve false items was related to the superior longitudinal fascicle connecting frontoparietal structures. Our results show that individual differences in white matter microstructure underlie true and false memory performance.

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The incidence of head and neck squamous cell carcinoma (HNSCC) has been gradually increasing over the last three decades. Recent data have now attributed a viral aetiology to a subset of head and neck cancers. Several studies indicate that oral human papillomavirus (HPV) infection is likely to be sexually acquired. The dominance of HPV 16 in HPV+ HNSCC is even greater than that seen in cervical carcinoma of total worldwide cases. Strong evidence suggests that HPV+ status is an important prognostic factor associated with a favourable outcome in head and neck cancers. Approximately 30 to 40% of HNSCC patients with present with early stage I/II disease. These patients are treated with curative intent using single modality treatments either radiation or surgery alone. A non-operative approach is favored for patients in which surgery followed by either radiation alone or radiochemotherapy may lead to severe functional impairment. Cetuximab, a humanized mouse anti-EGFR IgG1 monoclonal antibody, improved locoregional control and overall survival in combination with radiotherapy in locally advanced tumours but at the cost of some increased cardiac morbidity and mortality. Finally, the improved prognosis and treatment responses to chemotherapy and radiotherapy by HPV+ tumours may suggest that HPV status detection is required to better plan and individualize patient treatment regimes.

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Soitinnus: Ork.

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A recent publication reported an exciting polygenic effect of schizophrenia (SCZ) risk variants, identified by a large genome-wide association study (GWAS), on total brain and white matter volumes in schizophrenic patients and, even more prominently, in healthy subjects. The aim of the present work was to replicate and then potentially extend these findings. According to the original publication, polygenic risk scores using single nucleotide polymorphism (SNP) information of SCZ GWAS (polygenic SCZ risk scores; PSS) were calculated in 122 healthy subjects, enrolled in a structural magnetic resonance imaging (MRI) study. These scores were computed based on P-values and odds ratios available through the Psychiatric GWAS Consortium. In addition, polygenic white matter scores (PWM) were calculated, using the respective SNP subset in the original publication. None of the polygenic scores, either PSS or PWM, were found to be associated with total brain, white matter or gray matter volume in our replicate sample. Minor differences between the original and the present study that might have contributed to lack of reproducibility (but unlikely explain it fully), are number of subjects, ethnicity, age distribution, array technology, SNP imputation quality and MRI scanner type. In contrast to the original publication, our results do not reveal the slightest signal of association of the described sets of GWAS-identified SCZ risk variants with brain volumes in adults. Caution is indicated in interpreting studies building on polygenic risk scores without replication sample.

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Current evidences show that tacrolimus could be a good therapeutic option in patients non-responsive to first-line treatments and even it could become one of the first-line drugs for treating MG. Our study will try to determine the effectivity and safety of tacrolimus in 190 myasthenia gravis patients with suboptimal response to azathioprine: after 12 months of treatment they will be randomized to continue with azathioprine or they will be switched to tacrolimus. Patients will follow the allocated treatment during 14 months and the response will be assessed as well as adverse effectsPURPOSE: To compare azathioprine vs. tacrolimus effectivity and safety in MG patients with suboptimal response to azathioprine at 12 monthsDESIGN: A 14 months multicenter, prospective, randomized, double blind, head to head clinical trial