169 research outputs found
Prediction of Kick Count in Triathletes during Freestyle Swimming Session Using Inertial Sensor Technology
Monitoring sports training performances with automatic, low cost, low power, and ergonomic solutions is a topic of increasing importance in the research of the last years. A parameter of particular interest, which has not been extensively dealt with in a state-of-the-art way, is the count of kicks during swimming training sessions. Coaches and athletes set the training sessions to optimize the kick count and swim stroke rate to acquire velocity and acceleration during swimming. In regard to race distances, counting kicks can influence the athlete’s performance. However, it is difficult to record the kick count without facing some issues about subjective interpretation. In this paper, a new method for kick count is proposed, based on only one triaxial accelerometer worn on the athlete’s ankle. The algorithm was validated on data recorded during freestyle training sessions. An accuracy of 97.5% with a sensitivity of 99.3% was achieved. The proposed method shows good linearity and a slope of 1.01. These results overcome other state-of-the-art methods, proving that this method is a good candidate for a reliable, embedded kick count
Neuro-cognitive architecture of executive functions: A latent variable analysis
Executive functions refer to high-level cognitive processes that, by operating on lower-level mental processes, flexibly regulate and control our thoughts and goal-directed behavior. Despite their crucial role, the study of the nature and organization of executive functions still faces inherent difficulties. Moreover, most executive function models put under test until now are brain-free models: they are defined and discussed without assumptions regarding the neural bases of executive functions. By using a latent variable approach, here we tested a brain-centered model of executive function organization proposing that two distinct domain-general executive functions, namely, criterion setting and monitoring, may be dissociable both functionally and anatomically, with a left vs. right hemispheric preference of prefrontal cortex and related neural networks, respectively. To this end, we tested a sample of healthy participants on a battery of computerized tasks assessing criterion setting and monitoring processes and involving diverse task domains, including the verbal and visuospatial ones, which are well-known to be lateralized. By doing this, we were able to specifically assess the influence of these task domains on the organization of executive functions and to directly contrast a process-based model of EF organization versus both a purely domain-based model and a process-based, but domain-dependent one. The results of confirmatory factor analyses showed that a purely process-based model reliably provided a better fit to the observed data as compared to alternative models, supporting the specific theoretical model that fractionates a subset of executive functions into criterion setting and monitoring with hemispheric specializations emerging regardless of the task domain
Carcinosarcoma of the colon: report of a case with morphological, ultrastructural and molecular analysis
BACKGROUND: Carcinosarcoma of the colon is a rare histopathological entity with uncertain histogenesis, that shows both epithelial and mesenchymal malignant differentiation. Carcinosarcoma rarely affects the gastrointestinal tract and only few cases are reported in the colon. Herein we describe a carcinosarcoma of the ascending colon, with morphological, ultrastructural and molecular analysis. CASE PRESENTATION: An 81-year-old man was hospitalised for asthenia, weight loss and iron-deficiency anaemia. The patient underwent colonoscopy and adenocarcinoma was diagnosed by endoscopic biopsy. A right hemicolectomy was performed and, during surgical operation, liver metastases were detected. Histological examination of the surgical specimen revealed areas of both carcinomatous and sarcomatous differentiation, completely separated by fibrous septae. The sarcomatous component exhibited areas of smooth muscle and osteoblastic differentiation, with focal osteoid material deposition. Molecular analysis conducted separately on the epithelial and mesenchymal components revealed the same p53 gene mutation (R282W in exon 8) and identical polymorphisms in p53 exon 4, in EGFR exons 20 and 21, and in c-kit exon 17. Microsatellite markers analysis revealed a common loss of heterozygosis on 18q. Overall, the data are consistent with a common origin of the two tumor components. The patient was treated with 8 cycles of oral capecitabine (1250 mg/m(2 )twice a day for 14 days repeated every 28 days) and two years after surgery is alive with liver metastases. CONCLUSION: Carcinosarcoma of the colon is a rare tumour with both epithelial and sarcomatous components. Molecular analysis of the current case suggests the histogenesis from a common cell progenitor
Cerebral gray matter volume in patients with chronic migraine: correlations with clinical features
Abstract
Background
To date, few MRI studies have been performed in patients affected by chronic migraine (CM), especially in those without medication overuse. Here, we performed magnetic resonance imaging (MRI) voxel-based morphometry (VBM) analyses to investigate the gray matter (GM) volume of the whole brain in patients affected by CM. Our aim was to investigate whether fluctuations in the GM volumes were related to the clinical features of CM.
Methods
Twenty untreated patients with CM without a past medical history of medication overuse underwent 3-Tesla MRI scans and were compared to a group of 20 healthy controls (HCs). We used SPM12 and the CAT12 toolbox to process the MRI data and to perform VBM analyses of the structural T1-weighted MRI scans. The GM volume of patients was compared to that of HCs with various corrected and uncorrected thresholds. To check for possible correlations, patients’ clinical features and GM maps were regressed.
Results
Initially, we did not find significant differences in the GM volume between patients with CM and HCs (p < 0.05 corrected for multiple comparisons). However, using more-liberal uncorrected statistical thresholds, we noted that compared to HCs, patients with CM exhibited clusters of regions with lower GM volumes including the cerebellum, left middle temporal gyrus, left temporal pole/amygdala/hippocampus/pallidum/orbitofrontal cortex, and left occipital areas (Brodmann areas 17/18). The GM volume of the cerebellar hemispheres was negatively correlated with the disease duration and positively correlated with the number of tablets taken per month.
Conclusion
No gross morphometric changes were observed in patients with CM when compared with HCs. However, using more-liberal uncorrected statistical thresholds, we observed that CM is associated with subtle GM volume changes in several brain areas known to be involved in nociception/antinociception, multisensory integration, and analgesic dependence. We speculate that these slight morphometric impairments could lead, at least in a subgroup of patients, to the development and continuation of maladaptive acute medication usage
A [68Ga]Ga-DOTANOC PET/CT radiomic model for non-invasive prediction of tumour grade in pancreatic neuroendocrine tumours
Predicting grade 1 (G1) and 2 (G2) primary pancreatic neuroendocrine tumour (panNET) is crucial to foresee panNET clinical behaviour. 51 patients with G1-G2 primary panNET demonstrated by pre-surgical [68Ga]Ga-DOTANOC PET/CT and diagnostic conventional imaging were grouped according to the tumour grade assessment method: histology on the whole excised primary lesion (HS) or biopsy (BS). First-order and second-order radiomic features (RFs) were computed from SUV maps for the whole tumour volume on HS. The RFs showing the lowest p-values and the highest Area Under the Curve (AUC) were selected. Three radiomic models were assessed: A (trained on HS, validated on BS), B (trained on BS, validated on HS), C (using the cross-validation on the whole dataset). The second-order Normalized homogeneity and Entropy was the most effective RFs couple predicting G2 and G1. The best performance was achieved by model A (test AUC=0.90, sensitivity=0.88, specificity=0.89), followed by model C (median test AUC=0.87, sensitivity=0.83, specificity=0.82). Model B performed worse. Using HS to train a radiomic model leads to the best prediction, although a “hybrid” (HS+BS) population performs better than biopsy-only. The non-invasive prediction of panNET grading may be especially useful in lesions not amenable to biopsy while [68Ga]Ga-DOTANOC heterogeneity might recommend FDG PET/CT
imaging and biomarkers in gastroenteropancreatic neuroendocrine tumor disease management
The complexity of the clinical management of neuroendocrine neoplasia (NEN) is
exacerbated by limitations in imaging modalities and a paucity of clinically
useful biomarkers. Limitations in currently available imaging modalities
reflect difficulties in measuring an intrinsically indolent disease,
resolution inadequacies and inter-/intra-facility device variability and that
RECIST (Response Evaluation Criteria in Solid Tumors) criteria are not optimal
for NEN. Limitations of currently used biomarkers are that they are secretory
biomarkers (chromogranin A, serotonin, neuron-specific enolase and
pancreastatin); monoanalyte measurements; and lack sensitivity, specificity
and predictive capacity. None of them meet the NIH metrics for clinical usage.
A multinational, multidisciplinary Delphi consensus meeting of NEN experts (n
= 33) assessed current imaging strategies and biomarkers in NEN management.
Consensus (>75%) was achieved for 78% of the 142 questions. The panel
concluded that morphological imaging has a diagnostic value. However, both
imaging and current single-analyte biomarkers exhibit substantial limitations
in measuring the disease status and predicting the therapeutic efficacy.
RECIST remains suboptimal as a metric. A critical unmet need is the
development of a clinico-biological tool to provide enhanced information
regarding precise disease status and treatment response. The group considered
that circulating RNA was better than current general NEN biomarkers and
preliminary clinical data were considered promising. It was resolved that
circulating multianalyte mRNA (NETest) had clinical utility in both diagnosis
and monitoring disease status and therapeutic efficacy. Overall, it was
concluded that a combination of tumor spatial and functional imaging with
circulating transcripts (mRNA) would represent the future strategy for real-
time monitoring of disease progress and therapeutic efficacy
11C-choline vs. 18F-FDG PET/CT in assessing bone involvement in patients with multiple myeloma
<p>Abstract</p> <p>Background</p> <p>Multiple Myeloma (MM) is a B cell neoplasm causing lytic or osteopenic bone abnormalities. Whole body skeletal survey (WBSS), Magnetic resonance (MR) and <sup>18</sup>F-FDG PET/CT are imaging techniques routinely used for the evaluation of bone involvement in MM patients.</p> <p>Aim</p> <p>As MM bone lesions may present low <sup>18</sup>F-FDG uptake; the aim of this study was to assess the possible added value and limitations of <sup>11</sup>C-Choline to that of <sup>18</sup>F-FDG PET/CT in patients affected with MM.</p> <p>Methods</p> <p>Ten patients affected with MM underwent a standard <sup>11</sup>C-Choline PET/CT and an <sup>18</sup>F-FDG PET/CT within one week. The results of the two scans were compared in terms of number, sites and SUV<sub>max </sub>of lesions.</p> <p>Results</p> <p>Four patients (40%) had a negative concordant <sup>11</sup>C-Choline and <sup>18</sup>F-FDG PET/CT scans. Two patients (20%) had a positive <sup>11</sup>C-Choline and <sup>18</sup>F-FDG PET/CT scans that identified the same number and sites of bone lesions. The remaining four patients (40%) had a positive <sup>11</sup>C-Choline and <sup>18</sup>F-FDG PET/CT scan, but the two exams identified different number of lesions. Choline showed a mean SUV<sub>max </sub>of 5 while FDG showed a mean SUV<sub>max </sub>of 3.8 (P = 0.042). Overall, <sup>11</sup>C-Choline PET/CT scans detected 37 bone lesions and <sup>18</sup>F-FDG PET/CT scans detected 22 bone lesions but the difference was not significant (P = 0.8).</p> <p>Conclusion</p> <p>According to these preliminary data, <sup>11</sup>C-Choline PET/CT appears to be more sensitive than <sup>18</sup>F-FDG PET/CT for the detection of bony myelomatous lesions. If these data are confirmed in larger series of patients, <sup>11</sup>C-Choline may be considered a more appropriate functional imaging in association with MRI for MM bone staging.</p
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