4,407 research outputs found
Traceability and Provenance in Big Data Medical Systems
Providing an appropriate level of accessibility to and tracking of data or
process elements in large volumes of medical data, is an essential requirement
in the Big Data era. Researchers require systems that provide traceability of
information through provenance data capture and management to support their
clinical analyses. We present an approach that has been adopted in the neuGRID
and N4U projects, which aimed to provide detailed traceability to support
research analysis processes in the study of biomarkers for Alzheimers disease,
but is generically applicable across medical systems. To facilitate the
orchestration of complex, large-scale analyses in these projects we have
adapted CRISTAL, a workflow and provenance tracking solution. The use of
CRISTAL has provided a rich environment for neuroscientists to track and manage
the evolution of data and workflow usage over time in neuGRID and N4U.Comment: 6 pages, 3 diagrams. Proc of the 28th Int Symposium on Computer-Based
Medical Systems (CBMS 2015) Sao Carlos, Brazil. June 2015. arXiv admin note:
text overlap with arXiv:1502.0154
Visualizing Convolutional Networks for MRI-based Diagnosis of Alzheimer's Disease
Visualizing and interpreting convolutional neural networks (CNNs) is an
important task to increase trust in automatic medical decision making systems.
In this study, we train a 3D CNN to detect Alzheimer's disease based on
structural MRI scans of the brain. Then, we apply four different gradient-based
and occlusion-based visualization methods that explain the network's
classification decisions by highlighting relevant areas in the input image. We
compare the methods qualitatively and quantitatively. We find that all four
methods focus on brain regions known to be involved in Alzheimer's disease,
such as inferior and middle temporal gyrus. While the occlusion-based methods
focus more on specific regions, the gradient-based methods pick up distributed
relevance patterns. Additionally, we find that the distribution of relevance
varies across patients, with some having a stronger focus on the temporal lobe,
whereas for others more cortical areas are relevant. In summary, we show that
applying different visualization methods is important to understand the
decisions of a CNN, a step that is crucial to increase clinical impact and
trust in computer-based decision support systems.Comment: MLCN 201
The diatoms test in veterinary medicine: a pilot study on cetaceans and sea turtles
Fishing activities are considered one of the most relevant threats for cetaceans and sea turtles con- servation since these animals are sometimes found dead entangled in fishing gears. Currently, postmortem diagnosis is based mainly on the presence of nets and lines on the body and the related marks and injuries evident at gross examination. A more detailed and objective evidence is needed to clarify doubts cases and the diatoms technique, used in forensic human medicine, could support drowning diagnosis also in this field. Diatoms\u2019 investigation was implemented to be applied in ma- rine vertebrate on 8 striped (Stenella coeruleoalba) and 1 bottlenose (Tursiops truncatus) dolphins and 5 sea turtles (Caretta caretta) stranded along the Italian coastlines with a likely cause of death hypothized on necropsies carried out by veterinary pathologists. Diatoms were microscopically searched in the bone marrow collected from long bones implementing protocols used in human medicine and their presence was observed in 4 cetaceans and 2 sea turtles. Despite a clear relation between diatoms\u2019 presence and amount and the likely cause of death was not proved due to the poor number of samples, the higher burden of diatoms was found in 3 animals deemed to be death for the interaction with human activity. Despite more studied are necessary to identify the possible relation between the cause of death and diatoms\u2019 findings, the present study implemented this technique to be adapted to marine animals, confirming its possible application also in veterinary forensic medi- cine
Behavioral and Neurophysiological Effects of Transdermal Rotigotine in Atypical Parkinsonism
Effective therapies for the so-called atypical parkinsonian syndrome (APS) such as multiple system atrophy (MSA), progressive supranuclear palsy (PSP), or corticobasal syndrome (CBS) are not available. Dopamine agonists (DA) are not often used in APS because of inefficacy and in a minority of case, their side effects, like dyskinesias, impairment of extrapyramidal symptoms or the appearance of psychosis, and REM sleep behavioral disorders (RBD). Transdermal rotigotine (RTG) is a non-ergot dopamine agonist indicated for use in early and advanced Parkinson’s disease with a good tolerability and safety. Moreover, its action on a wide range of dopamine receptors, D1, D2, D3, unlike other DA, could make it a good option in APS, where a massive dopamine cell loss is documented. In this pilot, observational open-label study we evaluate the efficacy and tolerability of RTG in patients affected by APS. Thirty-two subjects with diagnosis of APS were treated with transdermal RTG. APS diagnosis was: MSA parkinsonian type (MSA-P), MSA cerebellar type (MSA-C), PSP, and CBS. Patients were evaluated by UPDRS-III, neuropsychiatric inventory, mini mental state examination at baseline, and after 6, 12, and 18 months. The titration schedule was maintained very flexible, searching the major clinical effect and the minor possible adverse events (AEs) at each visit. AEs were recorded. APS patients treated with RTG show an overall decrease of UPDRS-III scores without increasing behavioral disturbances. Only three patients were dropped out of the study. Main AEs were hypotension, nausea, vomiting, drowsiness, and tachycardia. The electroencephalographic recording power spectra analysis shows a decrease of theta and an increase of low alpha power. In conclusion, transdermal RTG seems to be effective and well tolerated in APS patients
Comparison of the effects of transdermal and oral rivastigmine on cognitive function and EEG markers in patients with Alzheimer’s disease
Background: Alzheimer's disease (AD) is the most common cause of dementia in older patients. Rivastigmine (RV, Exelon®, Novartis), a reversible cholinesterase inhibitor, improves clinical manifestations of AD and may enhance ACh-modulated electroencephalogram (EEG) alpha frequency. This pilot study aimed to determine the effects of two formulations of RV (transdermal patch [TV-RDP] and oral capsules [TV-CP]) on alpha frequency, in particular the posterior dominant rhythm, and cognitive function (assessed by the Mini-Mental State Examination [MMSE]) in patients with AD.Methods: Subjects with AD were assigned to receive either RV-TDP 10 cm2 or RV-CP 12 mg/day. All patients underwent EEG recordings at the beginning and end of the 18-month study period using P3, P4, O1 and O2 electrodes, each at high (10.5–13.0 Hz) and low (8.0–10.5 Hz) frequency. MMSE scores were determined at the start of the study (T0) and at three successive 6-month intervals (T1, T2 and T3).Results: RV-TDP administration (n=10) maintained cognitive function as evidenced by stable MMSE scores from baseline to 18 months (21.07 ± 2.4 to 21.2 ± 3.1) compared with a decrease in MMSE score with RV-CP (n=10) over 18 months (18.3 ± 3.6 to 13.6 ± 5.06 [adjusted for covariates p=0.006]). MMSE scores were significantly different between treatment groups from 6 months (p=0.04). RV-TDP also increased the spectral power of alpha waves in the posterior region measured with electrode P3 in a significantly great percentage of patients than TV-CP from baseline to 18 months; 80% versus 30%, respectively (p=0.025 [χ2 test]).Conclusion: RV-TDP was associated with a greater proportion of patients with increased posterior region alpha wave spectral power and significantly higher cognitive function at 18 months, compared with RV-CP treatment. Our findings suggest that RV-TDP provides an effective long-term management option in patients with AD compared with oral RV-CP. This study is a pilot, open-label study with
Expressions biogéologiques du confinement dans une lagune méditerranéenne : le lac Melah (Algérie)
Le lac Melah est un bassin paralique relativement profond communiquant avec la mer par un chenal étroit de faible profondeur. Ces caractéristiques ont pour conséquences la stratification des eaux et un fort confinement de l'ensemble du bassin qui engendre une biomasse phytoplanctonique élevée. Celle-ci est peu consommée par une macrofaune dense mais de faible biomasse et se dépose massivement sous la lentille d'eau inférieure anoxique. Le lac Melah apparaît ainsi comme un modèle actuel de bassin producteur de roches-mères d'hydrocarbures. En revanche, ses potentialités aquacoles sont limitées. (Résumé d'auteur
Automated hippocampal segmentation in 3D MRI using random undersampling with boosting algorithm
Detailed volumetric analysis of the hypothalamus in behavioral variant frontotemporal dementia
Abnormal eating behaviors are frequently reported in behavioral variant frontotemporal dementia (bvFTD). The hypothalamus is the regulatory center for feeding and satiety but its involvement in bvFTD has not been fully clarified, partly due to its difficult identification on MR images. We measured hypothalamic volume in 18 patients with bvFTD (including 9 MAPT and 6 C9orf72 mutation carriers) and 18 cognitively normal controls using a novel optimized multimodal segmentation protocol, combining 3D T1 and T2-weighted 3T MRIs (intrarater intraclass correlation coefficients ≥0.93). The whole hypothalamus was subsequently segmented into five subunits: the anterior (superior and inferior), tuberal (superior and inferior), and posterior regions. The presence of abnormal eating behavior was assessed with the revised version of the Cambridge Behavioural Inventory (CBI-R). The bvFTD group showed a 17 % lower hypothalamic volume compared with controls (p < 0.001): mean 783 (standard deviation 113) versus 944 (73) mm(3) (corrected for total intracranial volume). In the hypothalamic subunit analysis, the superior parts of the anterior and tuberal regions and the posterior region were significantly smaller in the bvFTD group compared with controls. There was a trend for a smaller hypothalamic volume, particularly in the superior tuberal region, in those with severe eating disturbance scores on the CBI-R. Differences were seen between the two genetic subgroups with significantly smaller volumes in the MAPT but not the C9orf72 group compared with controls. In summary, bvFTD patients had lower hypothalamic volumes compared with controls. Different genetic mutations may have a differential impact on the hypothalamus
Evaluation of the relative importance between gene loss and gene gain during mollicute evolution
Determinants of Quality of Life in Ageing Populations: Results from a Cross-Sectional Study in Finland, Poland and Spain
PURPOSE: To comprehensively identify the determinants of quality of life (QoL) in a population study sample of persons aged 18-50 and 50+. METHODS: In this observational, cross-sectional study, QoL was measured with the WHOQOL-AGE, a brief instrument designed to measure QoL in older adults. Eight hierarchical regression models were performed to identify determinants of QoL. Variables were entered in the following order: Sociodemographic; Health Habits; Chronic Conditions; Health State description; Vision and Hearing; Social Networks; Built Environment. In the final model, significant variables were retained. The final model was re-run using data from the three countries separately. RESULTS: Complete data were available for 5639 participants, mean age 46.3 (SD 18.4). The final model accounted for 45% of QoL variation and the most relevant contribution was given by sociodemographic data (particularly age, education level and living in Finland: 17.9% explained QoL variation), chronic conditions (particularly depression: 4.6%) and a wide and rich social network (4.6%). Other determinants were presence of disabling pain, learning difficulties and visual problems, and living in usable house that is perceived as non-risky. Some variables were specifically associated to QoL in single countries: age in Poland, alcohol consumption in Spain, angina in Finland, depression in Spain, and self-reported sadness both in Finland and Poland, but not in Spain. Other were commonly associated to QoL: smoking status, bodily aches, being emotionally affected by health problems, good social network and home characteristics. CONCLUSIONS: Our results highlight the importance of modifiable determinants of QoL, and provide public health indications that could support concrete actions at country level. In particular, smoking cessation, increasing the level of physical activity, improving social network ties and applying universal design approach to houses and environmental infrastructures could potentially increase QoL of ageing population
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