142 research outputs found

    Purification and quantification of recombinant Epstein-Barr viral glycoproteins gp350/220 from Chinese hamster ovary cells

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    Truncated Epstein-Barr virus (EBV) membrane antigen gp350/220 (EBV-MA) lacking the membrane anchor was expressed and secreted into the medium of recombinant Chinese hamster ovary cells that had been cultured in Plasmapur hollow-fibre modules using defined serum-free medium. The EBV-MA in the medium was concentrated by 70% (w/v) ammonium sulphate precipitation and subsequently purified by immunoaffinity chromatography using an anti-EBV-MA (EBV.0T6) monoclonal antibody (mAb) column. Adsorbed antigen was eluted with 3 M MgCl2 in phosphate-buffered saline, concentrated by Mono Q anion-exchange chromatography and analysed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis, silver staining and Western blotting using EBV-positive serum and anti-EBV-MA specific mAbs. Monospecific polyclonal rabbit antibodies against the purified EBV-MA were raised and purified by protein G affinity chromatography. For the measurement of EBV-MA antigen levels a sandwich enzyme-linked immunosorbent assay using rabbit polyclonal antibodies and a horseradish peroxidase-conjugated anti-MA mAb was developed having a detection level of 10 ng/ml

    Diagnostic performance of transthyretin measurement in fat tissue of patients with ATTR amyloidosis

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    In this article, the diagnostic performance of a transthyretin (TTR) ELISA for detection and characterization of transthyretin-derived (ATTR) amyloid in abdominal subcutaneous fat tissue was studied. Fat tissue specimens were analyzed of 38 patients with ATTR amyloidosis, 70 controls, and 17 carriers of a TTR mutation. Amyloid amount was graded semi-quantitatively in Congo red-stained specimens (0-4+). Amyloid was extracted from tissue in guanidine, and the TTR concentration was measured using a sandwich TTR-ELISA. The TTR concentration of patients with ATTR amyloidosis (mean 0.84 ng/mg fat tissue) was significantly higher than controls (p<0.001). With a TTR concentration of 0.13 ng/mg fat tissue as cut-off value, 32 of the 38 ATTR patients were identified resulting in a sensitivity of 84%. Sixty-seven of the 70 controls had values below the cut-off value resulting in a specificity of 96%. Thus, measuring TTR in fat tissue is useful for detecting ATTR amyloidosis and for characterizing amyloid as ATTR type

    Influence of solar irradiation on power transformer thermal balance

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    Accelerating regional atrophy rates in the progression from normal aging to Alzheimer’s disease

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    We investigated progression of atrophy in vivo, in Alzheimer’s disease (AD), and mild cognitive impairment (MCI). We included 64 patients with AD, 44 with MCI and 34 controls with serial MRI examinations (interval 1.8 ± 0.7 years). A nonlinear registration algorithm (fluid) was used to calculate atrophy rates in six regions: frontal, medial temporal, temporal (extramedial), parietal, occipital lobes and insular cortex. In MCI, the highest atrophy rate was observed in the medial temporal lobe, comparable with AD. AD patients showed even higher atrophy rates in the extramedial temporal lobe. Additionally, atrophy rates in frontal, parietal and occipital lobes were increased. Cox proportional hazard models showed that all regional atrophy rates predicted conversion to AD. Hazard ratios varied between 2.6 (95% confidence interval (CI) = 1.1–6.2) for occipital atrophy and 15.8 (95% CI = 3.5–71.8) for medial temporal lobe atrophy. In conclusion, atrophy spreads through the brain with development of AD. MCI is marked by temporal lobe atrophy. In AD, atrophy rate in the extramedial temporal lobe was even higher. Moreover, atrophy rates also accelerated in parietal, frontal, insular and occipital lobes. Finally, in nondemented elderly, medial temporal lobe atrophy was most predictive of progression to AD, demonstrating the involvement of this region in the development of AD

    Content and Quality of Motor Initiatives in the Support of People With Profound Intellectual and Multiple Disabilities

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    Motor activation is rarely integrated into the support of people with profound intellectual and multiple disabilities (PIMD), which might be the result of the limited evidence‐based knowledge in this field. Practitioners have recently been developing several motor initiatives for people with PIMD, but it remains unclear about what core elements the motor initiatives actually consist of and to what level of quality it is implemented in practice. This study aims to offer an overview and analysis of the content and quality of motor initiatives actually in use for people with PIMD. Motor initiatives were explored by asking practitioners to complete an online inventory form. Documents, expert knowledge, and observations were used to collect data about the characteristics of the motor initiatives. The quality of the motor initiatives which met our eligibility criteria, was analyzed on the basis of the level of evidence for their effectiveness. The inventory yielded 118 motor initiatives of which 17 met the eligibility criteria. We identified four motor initiatives reflecting an approach to motorically activate people with PIMD within various activities, three including power‐assisted exercises, three with aquatic exercises, two frameworks which integrated motor activities into their daily programs, two methods which included small‐scale activities, two rhythmic movement therapies, and one program including gross motor activities. We found limited indications for descriptive evidence from 17 initiatives, limited or no indications for theoretical evidence from 12 and five initiatives respectively, and none of the initiatives provided a causal level of evidence for effectiveness. A wide variety of motor initiatives is used in current practice to activate persons with PIMD, although their effectiveness is actually unproven. Science and practice should cooperate to develop an evidence‐based understanding to ensure more evidence‐based support for the motor activation of people with PIMD in the future

    The Search for Invariance: Repeated Positive Testing Serves the Goals of Causal Learning

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    Positive testing is characteristic of exploratory behavior, yet it seems to be at odds with the aim of information seeking. After all, repeated demonstrations of one’s current hypothesis often produce the same evidence and fail to distinguish it from potential alternatives. Research on the development of scientific reasoning and adult rule learning have both documented and attempted to explain this behavior. The current chapter reviews this prior work and introduces a novel theoretical account—the Search for Invariance (SI) hypothesis—which suggests that producing multiple positive examples serves the goals of causal learning. This hypothesis draws on the interventionist framework of causal reasoning, which suggests that causal learners are concerned with the invariance of candidate hypotheses. In a probabilistic and interdependent causal world, our primary goal is to determine whether, and in what contexts, our causal hypotheses provide accurate foundations for inference and intervention—not to disconfirm their alternatives. By recognizing the central role of invariance in causal learning, the phenomenon of positive testing may be reinterpreted as a rational information-seeking strategy

    Factors influencing the admission decision for Medical Psychiatry Units: A concept mapping approach

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    Objective Medical Psychiatry Units (MPUs), also known as Complexity Intervention Units (CIUs), provide care for complex patients suffering from both psychiatric and physical disorders. Because there is no consensus on the indications for admission to an MPU, daily practice and effectiveness research are hampered. This study therefore used a concept mapping approach to investigate which organizational and medical factors determine the decision to admit a patient to an MPU. Methods The first step of the concept mapping approach was to create a list of factors determining MPU admission from literature. Secondly, clinical experts sorted and ranked these factors. The sorted and ranked data were then analyzed, and a draft conceptual framework was created. A final conceptual MPU admission framework was then drawn during an expert consensus meeting and recommendations for implementation were suggested. Results Thirteen clinical experts defined 90 factors from literature, which were sorted and ranked by 40 experts from 21 Dutch hospitals. This concept mapping approach resulted in a five-cluster solution for an MPU admission framework based on: 1. Staff competencies and organizational pre-requisites; 2. Patient context; 3. Patient characteristics; 4. Medical needs and capabilities; and 5. Psychiatric symptoms and behavioral problems. Furthermore, three inclusion and two exclusion criteria were formulated to help the clinicians decide whether or not to admit patients to an MPU. These criteria can be implemented in daily practice. Conclusion Implementing the five criteria derived from this conceptual framework will help make the admission decision for complex patients with psychiatric and physical disorders to an MPU more correct, consistent, and transparent

    Novelty Response of Wild African Apes to Camera Traps

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    Temperament and personality research in humans and nonhuman animals measures behavioral variation in individual, population, or species-specific traits with implications for survival and fitness, such as social status, foraging and mating success [1–5]. Curiosity and risk-taking tendencies have been studied extensively across taxa by measuring boldness and exploration responses to experimental novelty exposure [3,4,6–15]. Here, we conduct a natural field experiment using wildlife monitoring technology to test variation in the reaction of wild great apes (43 groups of naïve chimpanzees, bonobos and western gorillas, across 14 field sites in Africa) to a novel object, the camera-trap. Bonobo and gorilla groups demonstrated a stronger looking impulse towards the camera-trap device compared to chimpanzees, suggesting higher visual attention and curiosity. Bonobos were also more likely to show alarm and other fearful behaviors, although such neophobic (and conversely, neophilic) responses were generally rare. Among all three species, individuals looked at cameras longer when they were young, were associating with fewer individuals, and did not live near a long-term research site. Overall, these findings partially validate results from great ape novelty paradigms in captivity [7,8]. We further suggest that species-typical leadership styles [16] and social and environmental effects, including familiarity with humans, best explain novelty responses of wild great apes. In sum, this study illustrates the feasibility of large-scale field experiments and the importance of both intrinsic and extrinsic factors in shaping animal curiosity
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