101 research outputs found

    Case report of a primary subcutaneous melanoma:a surprising entity for a subcutaneous nodule

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    INTRODUCTION: A melanoma can originate at the subcutis without any visible skin lesion. CASE PRESENTATION: A 73-year old patient came to the outpatient clinic with a subcutaneous nodule on the right thigh without any visible lesion of the skin. It turned out to be a primary subcutaneous melanoma that could be classified as a primary dermal melanoma (PDM). DISCUSSION: A PDM is a very rare subtype of melanoma that stands out for its excellent prognosis in comparison to cutaneous melanomas. No valid reliable staging system or treatment guideline exists for this entity, Breslow depth might overestimate the clinical aggressiveness possibly leading to overtreatment. CONCLUSION: It is of great importance for the clinician to be familiar with a primary dermal melanoma. It deserves an appropriate place in the current AJCC system and a treatment guideline for this unique melanoma subtype with relativity excellent prognosis would be beneficial

    Survival following surgical treatment for anorectal melanoma seems similar for local excision and extensive resection regardless of nodal involvement

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    Background: Anorectal melanoma is a rare malignancy with a dismal prognosis. The purpose of this study was to investigate whether the survival per stage is influenced by the surgical approaches (local excision or extensive resection), to assess prognostic factors of survival, and to answer the question whether the practiced surgical approaches changed over time. Methods: Dutch cancer registry organizations (IKNL and PALGA) were queried for all patients with a diagnosis of anorectal melanoma (1989-2019). Patients with disseminated disease at diagnosis were excluded. Survival outcomes were compared for the two surgical approaches stratified by stage (clinical node negative (cN0) and clinical node positive (cN+)) and date of diagnosis. Results: A total of 103 patients were included in this study. In both cN0 and cN+ patients the surgical strategy did not significantly influence survival (cN0: 21.7% 5-year survival, median 25 months for local excision versus 13.7% 5-year survival, median 17 months for extensive resection (p = 0.228), cN+: 11.1% 5-year survival for local excision, median 17 months versus 8.7% 5-year survival, median 14 months for extensive resection (p = 0.741)). Stage and date of diagnosis showed to be prognostic factors of survival. The ratio between the two surgical approaches was unchanged over three decades. Conclusions: Extensive resection does not seem to improve survival in both cN0 and cN+ anorectal melanoma patients compared to local excision. However in the past three decades no shift towards local excision has been found. cN+ stage and an older date of diagnosis are predictors for worse survival

    What's in a score:A longitudinal investigation of scores based on item response theory and classical test theory for the Amsterdam Instrumental Activities of Daily Living Questionnaire in cognitively normal and impaired older adults

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    OBJECTIVE:We aimed to investigate whether item response theory (IRT)-based scoring allows for a more accurate, responsive, and less biased assessment of everyday functioning than traditional classical test theory (CTT)-based scoring, as measured with the Amsterdam Instrumental Activities of Daily Living Questionnaire. METHOD: In this longitudinal multicenter study including cognitively normal and impaired individuals, we examined IRT-based and CTT-based score distributions and differences between diagnostic groups using linear regressions, and investigated scale attenuation. We compared change over time between scoring methods using linear mixed models with random intercepts and slopes for time.RESULTS: Two thousand two hundred ninety-four participants were included (66.6 ± 7.7 years, 54% female): n = 2,032 (89%) with normal cognition, n = 93 (4%) with subjective cognitive decline, n = 79 (3%) with mild cognitive impairment, and n = 91 (4%) with dementia. At baseline, IRT-based and CTT-based scores were highly correlated (r = -0.92). IRT-based scores showed less scale attenuation than CTT-based scores. In a subsample of n = 1,145 (62%) who were followed for a mean of 1.3 (SD = 0.6) years, IRT-based scores declined significantly among cognitively normal individuals (unstandardized coefficient [B] = -0.15, 95% confidence interval, 95% CI [-0.28, -0.03], effect size = -0.02), whereas CTT-based scores did not (B = 0.20, 95% CI [-0.02, 0.41], effect size = 0.02). In the other diagnostic groups, effect sizes of change over time were similar. CONCLUSIONS: IRT-based scores were less affected by scale attenuation than CTT-based scores. With regard to responsiveness, IRT-based scores showed more signal than CTT-based scores in early disease stages, highlighting the IRT-based scores' superior suitability for use in preclinical populations. (PsycInfo Database Record (c) 2023 APA, all rights reserved).</p

    Assessing cognition and daily function in early dementia using the cognitive-functional composite:findings from the Catch-Cog study cohort

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    BackgroundThe cognitive-functional composite (CFC) was designed to improve the measurement of clinically relevant changes in predementia and early dementia stages. We have previously demonstrated its good test-retest reliability and feasibility of use. The current study aimed to evaluate several quality aspects of the CFC, including construct validity, clinical relevance, and suitability for the target population.MethodsBaseline data of the Capturing Changes in Cognition study was used: an international, prospective cohort study including participants with subjective cognitive decline (SCD), mild cognitive impairment (MCI), Alzheimer's disease (AD) dementia, and dementia with Lewy bodies (DLB). The CFC comprises seven existing cognitive tests focusing on memory and executive functions (EF) and the informant-based Amsterdam Instrumental Activities of Daily Living Questionnaire (A-IADL-Q). Construct validity and clinical relevance were assessed by (1) confirmatory factor analyses (CFA) using all CFC subtests and (2) linear regression analyses relating the CFC score (independent) to reference measures of disease severity (dependent), correcting for age, sex, and education. To assess the suitability for the target population, we compared score distributions of the CFC to those of traditional tests (Alzheimer's Disease Assessment Scale-Cognitive subscale, Alzheimer's Disease Cooperative Study-Activities of Daily Living scale, and Clinical Dementia Rating scale).ResultsA total of 184 participants were included (age 71.88.4; 42% female; n=14 SCD, n=80 MCI, n=78AD, and n=12 DLB). CFA showed that the hypothesized three-factor model (memory, EF, and IADL) had adequate fit (CFI=.931, RMSEA=.091, SRMR=.06). Moreover, worse CFC performance was associated with more cognitive decline as reported by the informant (=.61, p</p

    ICA-Derived Respiration Using an Adaptive R-peak Detector

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    Breathing Rate (BR) plays a key role in health deterioration monitoring. Despite that, it has been neglected due to inadequate nursing skills and insufficient equipment. ECG signal, which is always monitored in a hospital ward, is affected by respiration which makes it a highly appealing way for the BR estimation. In addition, the latter requires accurate R-peak detection, which is a continuing concern because current methods are still inaccurate and miss heart beats. This study proposes a frequency domain BR estimation method which uses a novel real-time R-peak detector based on Empirical Mode Decomposition (EMD) and a blind source ICA for separating the respiratory signal. The originality of the BR estimation method is that it takes place in the frequency domain as opposed to some of the current methods which rely on a time domain analysis, making the estimation more accurate. Moreover, our novel QRS detector uses an adaptive threshold over a sliding window and differentiates large Q-peaks from R-peaks, facilitating a more accurate BR estimation. The performance of our methods was tested on real data from Capnobase dataset. An average mean absolute error of less than 0.7 breath per minute was achieved using our frequency domain method, compared to 15 breaths per minute of the time domain analysis. Moreover, our modified QRS detector shows comparable results to other published methods, achieving a detection rate over 99.80%

    Toward a theory‐based specification of non‐pharmacological treatments in aging and dementia: Focused reviews and methodological recommendations

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    INTRODUCTION: Non-pharmacological treatments (NPTs) have the potential to improve meaningful outcomes for older people at risk of, or living with dementia, but research often lacks methodological rigor and continues to produce mixed results. METHODS: In the current position paper, experts in NPT research have specified treatment targets, aims, and ingredients using an umbrella framework, the Rehabilitation Treatment Specification System. RESULTS: Experts provided a snapshot and an authoritative summary of the evidence for different NPTs based on the best synthesis efforts, identified main gaps in knowledge and relevant barriers, and provided directions for future research. Experts in trial methodology provide best practice principles and recommendations for those working in this area, underscoring the importance of prespecified protocols. DISCUSSION: We conclude that the evidence strongly supports various NPTs in relation to their primary targets, and discuss opportunities and challenges associated with a unifying theoretical framework to guide future efforts in this area

    Selection and characterisation of a phage-displayed human antibody (Fab) reactive to the lung resistance-related major vault protein

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    The major vault protein is the main component on multimeric vault particles, that are likely to play an essential role in normal cell physiology and to be associated with multidrug resistance of tumour cells. In order to unravel the function of vaults and their putative contribution to multidrug resistance, specific antibodies are invaluable tools. Until now, only conventional major vault protein-reactive murine monoclonal antibodies have been generated, that are most suitable for immunohistochemical analyses. The phage display method allows for selection of human antibody fragments with potential use in clinical applications. Furthermore, cDNA sequences encoding selected antibody fragments are readily identified, facilitating various molecular targeting approaches. In order to obtain such human Fab fragments recognising major vault protein we used a large non-immunized human Fab fragment phage library. Phages displaying major vault protein-reactive Fabs were obtained through several rounds of selection on major vault protein-coated immunotubes and subsequent amplification in TG1 E coli bacteria. Eventually, one major vault protein-reactive clone was selected and further examined. The anti-major vault protein Fab was found suitable for immunohistochemical and Western blot analysis of tumour cell lines and human tissues. BIAcore analysis showed that the binding affinity of the major vault protein-reactive clone almost equalled that of the murine anti-major vault protein Mabs. The cDNA sequence of this human Fab may be exploited to generate an intrabody for major vault protein-knock out studies. Thus, this human Fab fragment should provide a valuable tool in elucidating the contribution(s) of major vault protein/vaults to normal physiology and cellular drug resistance mechanisms

    An Introduction to EEG Source Analysis with an illustration of a study on Error-Related Potentials

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    International audienceOver the last twenty years blind source separation (BSS) has become a fundamental signal processing tool in the study of human electroencephalography (EEG), other biological data, as well as in many other signal processing domains such as speech, images, geophysics and wireless communication (Comon and Jutten, 2010). Without relying on head modeling BSS aims at estimating both the waveform and the scalp spatial pattern of the intracranial dipolar current responsible of the observed EEG, increasing the sensitivity and specificity of the signal received from the electrodes on the scalp. This chapter begins with a short review of brain volume conduction theory, demonstrating that BSS modeling is grounded on current physiological knowledge. We then illustrate a general BSS scheme requiring the estimation of second-order statistics (SOS) only. A simple and efficient implementation based on the approximate joint diagonalization of covariance matrices (AJDC) is described. The method operates in the same way in the time or frequency domain (or both at the same time) and is capable of modeling explicitly physiological and experimental source of variations with remarkable flexibility. Finally, we provide a specific example illustrating the analysis of a new experimental study on error-related potentials
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