Search

This article presents findings from an empirical study on the relations between the variables comprising learning mechanisms in small collaborative groups. Variables comprising the central learning mechanisms component were "task related interactions," "knowledge elaborations," and "subjective estimation of knowledge acquisition." Student related determinants of the learning processes were "dysfunctional behavior," and "work group management." Tutor related determinants were "tutor facilitative behavior" (facilitation, questioning, and mini-lecturing), and "tutor work group management." The selected variables were structured into a path model. The first question concerned the way the three variables comprising the learning mechanisms component are related to each other. We have contrasted mediation vs. addition hypothesis. The second question concerned the validity of the complete small group functioning model. In order to answer these questions we have constructed a questionnaire and administered it to 89 1st year medical students. Concerning the first question, the data were in accordance with the mediation hypothesis. Specific analyses showed that only the collaborative sequence type of task related interactions had positive effects on both knowledge elaborations and knowledge acquisition. In contrast the transfer of knowledge type of interactions had negative effects on the same variables. Test of the validity of the complete model showed a satisfactory model fit. Briefly, our findings suggest that a large proportion of collaborative sequences in the group, together with a low proportion of dysfunctional behavior and highly facilitative behavior of the tutor will lead to a high proportion of knowledge elaborations. Knowledge elaborations positively affect knowledge acquisition which is an important determinant of the student satisfaction and motivation.

A novel Drosophila gene, act up (acu), controls actin polymerization to alter cell shape and restrict hedgehog signaling in the eye disc of the insect. It appears that dynamic changes in actin filaments may change cell shape, controlling signal movement to coordinate a differentiation wave.

The objective of the study was to explore, in a sample of spouses of mild-to-moderate Alzheimer disease patients, predictors of quality of life (QoL) by rating QoL and burden. The authors assessed 97 spouses in a cross-sectional study with the Schedule for the Evaluation of Individual Quality of Life (SEIQoL), Self-Rated Burden scale (SRB), self-perceived stress scale (EDIZ; Ervaren Druk door Informele Zorg/Self-Perceived Pressure from Informal Care), and Zarit Burden Interview (ZBI). Patient cognition was rated with the Mini-Mental State Examination (MMSE). Factors best predicting QoL were analyzed with multiple regression analysis. Eighty-seven (53% male, mean 72 y) fulfilled the SEIQoL internal reliability criteria, and had a mean SEIQoL score of 68.6+/-14.8. Most important QoL domains were condition of patient (31%) and marriage (26%). Caregiver burden scores on SRB, Ervaren Druk door Informele, Zorg, and ZBI were 44.1+/-23.5 (n=67), 4.9+/-2.2 (n=53), and 13.1+/-6.2 (n=53), respectively. Mean patient MMSE score (0 to 30) was 20.3+/-4.2. Spouses experienced lower QoL than Alzheimer disease patients and healthy elderly (historical controls), and perceived moderate levels of burden. Patient cognition is a significant predictor of caregiver QoL. Burden, measured by ZBI, is significantly negatively correlated with SEIQoL. The results underline the importance of implementing health services known to improve QoL and alleviate burden, and to explore new effective interventions. [ABSTRACT FROM AUTHOR]

The electrochemical behaviour of the Fe 3+ -sulphonated pyrogallol (SP) complex was investigated and its composition and stability constants were determinated at pH 2.30. It was found by voltammetric and spectrophotometric measurements that Fe 3+ and SP form a complex of the ML2 type, which is relatively stable during the first 30 minutes. The optimal pH value for complex formation is between 2.30 and 2.80. The relative stability constants determined by voltammetric and spectrophotometric measurements are log β2 = 5.08±0.26 and log β2 = 6.31 ±0.04, respectively.

Abstract Background The effectiveness and efficiency of nursing-home dementia care are suboptimal: there are high rates of neuropsychiatric symptoms among the residents and work-related stress among the staff. Dementia-care mapping is a person-centred care method that may alleviate both the resident and the staff problems. The main objective of this study is to evaluate the effectiveness and cost-effectiveness of dementia-care mapping in nursing-home dementia care. Methods/Design The study is a cluster-randomised controlled trial, with nursing homes grouped in clusters. Studywise minimisation is the allocation method. Nursing homes in the intervention group will receive a dementia-care-mapping intervention, while the control group will receive usual care. The primary outcome measure is resident agitation, to be assessed with the Cohen-Mansfield Agitation Inventory. The secondary outcomes are resident neuropsychiatric symptoms, assessed with the Neuropsychiatric Inventory - Nursing Homes and quality of life, assessed with Qualidem and the EQ-5D. The staff outcomes are stress reactions, job satisfaction and job-stress-related absenteeism, and staff turnover rate, assessed with the Questionnaire about Experience and Assessment of Work, the General Health Questionnaire-12, and the Maastricht Job Satisfaction Scale for Health Care, respectively. We will collect the data from the questionnaires and electronic registration systems. We will employ linear mixed-effect models and cost-effectiveness analyses to evaluate the outcomes. We will use structural equation modelling in the secondary analysis to evaluate the plausibility of a theoretical model regarding the effectiveness of the dementia-care mapping intervention. We will set up process analyses, including focus groups with staff, to determine the relevant facilitators of and barriers to implementing dementia-care mapping broadly. Discussion A novelty of dementia-care mapping is that it offers an integral person-centred approach to dementia care in nursing homes. The major strengths of the study design are the large sample size, the cluster-randomisation, and the one-year follow-up. The generalisability of the implementation strategies may be questionable because the motivation for person-centred care in both the intervention and control nursing homes is above average. The results of this study may be useful in improving the quality of care and are relevant for policymakers. Trial registration The trial is registered in the Netherlands National Trial Register: NTR2314.

Abstract Background Early diagnosis of dementia benefits both patient and caregiver. Nevertheless, dementia in primary care is currently under-diagnosed. Some educational interventions developed to improve dementia diagnosis and management were successful in increasing the number of dementia diagnoses and in changing attitudes and knowledge of health care staff. However, none of these interventions focussed on collaboration between GPs and nurses in dementia care. We developed an EASYcare-based Dementia Training Program (DTP) aimed at stimulating collaboration in dementia primary care. We expect this program to increase the number of cognitive assessments and dementia diagnoses and to improve attitudes and knowledge of GPs and nurses. Methods The DTP is a complex educational intervention that consists of two workshops, a coaching program, access to an internet forum, and a Computerized Clinical Decision Support System on dementia diagnostics. One hundred duos of GPs and nurses will be recruited, from which 2/3 will be allocated to the intervention group and 1/3 to the control group. The effects of implementation of the DTP will be studied in a cluster-randomised controlled trial. Primary outcomes will be the number of cognitive assessments and dementia diagnoses in a period of 9 months following workshop participation. Secondary outcomes are measured on GP and nurse level: adherence to national guidelines for dementia, attitude, confidence and knowledge regarding dementia diagnosis and management; on patient level: number of emergency calls, visits and consultations and patient satisfaction; and on caregiver level: informal caregiver burden and satisfaction. Data will be collected from GPs' electronic medical records, self-registration forms and questionnaires. Statistical analysis will be performed using the MANOVA-method. Also, exploratory analyses will be performed, in order to gain insight into barriers and facilitators for implementation and the possible causal relations between the rate of success of the intervention components and the outcomes. Discussion We developed multifaceted dementia training programme. Novelties in this programme are the training in fixed collaborative duos and the inclusion of an individual coaching program. The intervention is designed according to international guidelines and educational standards. Exploratory analysis will reveal its successful elements. Selection bias and contamination may be threats to the reliability of future results of this trial. Nevertheless, the results of this trial may provide useful information for policy makers and developers of continuing medical education. Trial registration ClinicalTrials.gov ID NCT00459784

Dyskeratosis congenita is a cancer-prone inherited bone marrow failure syndrome caused by telomere dysfunction. A mouse model recently suggested that p53 regulates telomere metabolism, but the clinical relevance of this finding remained uncertain. Here, a germline missense mutation of MDM4 , a negative regulator of p53, was found in a family with features suggestive of dyskeratosis congenita, e.g., bone marrow hypocellularity, short telomeres, tongue squamous cell carcinoma, and acute myeloid leukemia. Using a mouse model, we show that this mutation (p.T454M) leads to increased p53 activity, decreased telomere length, and bone marrow failure. Variations in p53 activity markedly altered the phenotype of Mdm4 mutant mice, suggesting an explanation for the variable expressivity of disease symptoms in the family. Our data indicate that a germline activation of the p53 pathway may cause telomere dysfunction and point to polymorphisms affecting this pathway as potential genetic modifiers of telomere biology and bone marrow function., (Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution License 4.0 (CC BY).)

G-quadruplex ligands exert their antiproliferative effects through telomere-dependent and telomere-independent mechanisms, but the inter-relationships among autophagy, cell growth arrest and cell death induced by these ligands remain largely unexplored. Here, we demonstrate that the G-quadruplex ligand 20A causes growth arrest of cancer cells in culture and in a HeLa cell xenografted mouse model. This response is associated with the induction of senescence and apoptosis. Transcriptomic analysis of 20A treated cells reveals a significant functional enrichment of biological pathways related to growth arrest, DNA damage response and the lysosomal pathway. 20A elicits global DNA damage but not telomeric damage and activates the ATM and autophagy pathways. Loss of ATM following 20A treatment inhibits both autophagy and senescence and sensitizes cells to death. Moreover, disruption of autophagy by deletion of two essential autophagy genes ATG5 and ATG7 leads to failure of CHK1 activation by 20A and subsequently increased cell death. Our results, therefore, identify the activation of ATM by 20A as a critical player in the balance between senescence and apoptosis and autophagy as one of the key mediators of such regulation. Thus, targeting the ATM/autophagy pathway might be a promising strategy to achieve the maximal anticancer effect of this compound., (© The Author(s) 2019. Published by Oxford University Press on behalf of Nucleic Acids Research.)

Purpose: Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumors. Whereas most PPGLs are benign, up to 20% may become metastatic with SDHB - and FH -mutated tumors showing the higher risk. We aimed at determining the contribution of immortalization mechanisms to metastatic progression. Experimental Design: Immortalization mechanisms were investigated in 200 tumors. To identify telomerase (+) tumors, we analyzed genomic alterations leading to transcriptional activation of TERT comprising promoter mutations, hypermethylation and gain copy number. To identify tumors that activated the alternative lengthening of telomere (ALT) mechanism, we combined analyses of telomere length by slot blot, telomere heterogeneity by telomere FISH, and ATRX mutations by next-generation sequencing. Univariate/multivariate and metastasis-free survival (MFS) and overall survival (OS) analyses were carried out for assessment of risk factors and clinical outcomes., Results: Only 37 of 200 (18.5%) tumors achieved immortalization. Telomerase activation occurred in 12 metastatic tumors and was prevalent in SDHB -mutated paragangliomas ( P = 2.42e-09). ALT features were present in 25 tumors, mostly pheochromocytomas, regardless of metastatic status or molecular group ( P = 0.169), yet ATRX mutations were found preferentially in SDHB/FH -mutated metastatic tumors ( P = 0.0014). Telomerase activation and ATRX mutations were independent factors of poor prognosis: MFS (hazard ratio, 48.2 and 33.1; P = 6.50E-07 and 1.90E-07, respectively); OS (hazard ratio, 97.4 and 44.1; P = 4.30E-03 and 2.00E-03, respectively) and were associated with worse MFS and OS (log-rank tests P < 0.0001)., Conclusions: Assessment of telomerase activation and ATRX mutations could be used to identify metastatic PPGLs, particularly in tumors at high risk of progression., (©2018 American Association for Cancer Research.)

Telomere maintenance protects the cell against genome instability and senescence. Accelerated telomere attrition is a characteristic of premature aging syndromes including Dyskeratosis congenita (DC). Mutations in hRTEL1 are associated with a severe form of DC called Hoyeraal-Hreidarsson syndrome (HHS). HHS patients carry short telomeres and HHS cells display telomere damage. Here we investigated how hRTEL1 contributes to telomere maintenance in human primary as well as tumor cells. Transient depletion of hRTEL1 resulted in rapid telomere shortening only in the context of telomerase-positive cells with very long telomeres and high levels of telomerase. The effect of hRTEL1 on telomere length is telomerase dependent without impacting telomerase biogenesis or targeting of the enzyme to telomeres. Instead, RTEL1 depletion led to a decrease in both G-overhang content and POT1 association with telomeres with limited telomere uncapping. Strikingly, overexpression of POT1 restored telomere length but not the overhang, demonstrating that G-overhang loss is the primary defect caused by RTEL1 depletion. We propose that hRTEL1 contributes to the maintenance of long telomeres by preserving long G-overhangs, thereby facilitating POT1 binding and elongation by telomerase.

Genetic organization is governed by the interaction of DNA with histone proteins, and differential modifications of these proteins is a fundamental mechanism of gene regulation. Histone modifications are primarily studied through chromatin immunoprecipitation (ChIP) assays, however conventional ChIP procedures are time consuming, laborious and require a large number of cells. Here we report for the first time the development of ChIP in droplets based on a microfluidic platform combining nanoliter droplets, magnetic beads (MB) and magnetic tweezers (MT). The droplet approach enabled compartmentalization and improved mixing, while reducing the consumption of samples and reagents in an integrated workflow. Anti-histone antibodies grafted to MB were used as a solid support to capture and transfer the target chromatin from droplets to droplets in order to perform chromatin immunoprecipitation, washing, elution and purification of DNA. We designed a new ChIP protocol to investigate four different types of modified histones with known roles in gene activation or repression. We evaluated the performances of this new ChIP in droplet assay in comparison with conventional methods. The proposed technology dramatically reduces analytical time from a few days to 7 hours, simplifies the ChIP protocol and decreases the number of cells required by 100 fold while maintaining a high degree of sensitivity and specificity. Therefore this droplet-based ChIP assay represents a new, highly advantageous and convenient approach to epigenetic analyses.

Microfluidics offer powerful tools for the control, manipulation, and analysis of cells, in particular for the assessment of cell malignancy or the study of cell subpopulations. However, implementing complex biological protocols on chip remains a challenge. Sample preparation is often performed off chip using multiple manually performed steps, and protocols usually include different dehydration and drying steps that are not always compatible with a microfluidic format.Here, we report the implementation of a Fluorescence in situ Hybridization (FISH) protocol for the molecular typing of cancer cells in a simple and low-cost device. The geometry of the chip allows integrating the sample preparation steps to efficiently assess the genomic content of individual cells using a minute amount of sample. The FISH protocol can be fully automated, thus enabling its use in routine clinical practice.

Microfluidic systems bear promise to provide new powerful tools for the molecular characterization of cancer cells, in particular for the routine detection of multiple cancer biomarkers using a minute amount of the sample. However, taking miniaturized cell-based assays into the clinics requires the implementation and validation of complex biological protocols on chip, as well as the development of disposable microdevices produced at a low cost. Based on a recently developed microfluidic chip made of Cyclic Olefin Copolymer for cell immobilization with minimal dead volume and controlled shear stress, we developed a protocol performed entirely in the liquid phase, allowing the immobilization and fixation of cells and their quantitative characterization by fluorescence in situ hybridization. We demonstrated first in cell lines and then in two clinical case studies the potential of this method to perform quantitative copy number measurement and clinical scoring of the amplification of the ERBB2 gene, a decisive biomarker for the prescription of HER2+ related targeted therapies. This validation was performed in a blind protocol in two clinical case studies, in reference to the gold standard and clinically used method based on glass slides. We obtained a comparable reproducibility and a minor difference in apparent amplification, which can be corrected by internal calibration. The method thus reaches the standard of robustness needed for clinical use. The protocol can be fully automated, and its consumption of samples and DNA probes is reduced as compared to glass slide protocols by a factor of at least 10. The total duration of the assay is divided by two.

Objective: To assess the effectiveness of non-equipment based rehabilitation interventions for older adults with an age-related hearing or visual impairment., Data Sources: We searched PubMed, EMBASE, PsychInfo, CINAHL, and the Cochrane Central Register of Controlled Trials., Review Methods: Two authors independently assessed trial eligibility, extracted data and assessed methodological quality. Controlled studies with more than 80% of participants aged ≥ 55 years and with rehabilitation interventions either separately or in combination with technical device provision were included. Meta-analyses were undertaken for the primary outcomes: emotional status, functional status, self-efficacy and social participation. All studies were categorized into 3 subgroups of intervention approaches (cognitive restructuring, education, and problem-solving), and subgroup analysis was performed., Results: Fourteen studies were identified: six on hearing impairment and eight on visual impairment, involving 1622 sensory impaired participants (mean age 70). Methodological quality of the studies was modest. Eight studies offered data for meta-analysis. No significant effects in favour of interventions on either emotional or functional status, self-efficacy, or social participation were found. In the subgroup analysis, only the problem-solving approach showed a positive effect on emotional status., Conclusions: This review found no effects of non-equipment based rehabilitation interventions on emotional and functional status, self-efficacy, and social participation. However, subgroup analysis showed problem-solving as a potential effective approach for positively affecting emotional status., (© The Author(s) 2014.)

Background: Aneurysmal subarachnoid hemorrhage (aSAH) is a condition affecting relatively young patients and has high rates of morbidity and mortality. Online health communities have emerged to fill the void for patient advocacy and information, allowing individuals with shared experiences and chronic disorders to connect., Objective: We have developed an online health community for aSAH patients, and this pilot study was conducted to evaluate it from a patient's perspective., Methods: We implemented an online, members-only, health community (MijnSAB, translation: MySAH) in addition to the usual aSAH care at Radboudumc, Nijmegen, the Netherlands. A questionnaire that was sent to consecutive aSAH patients was used to evaluate the usability and utility of MySAH. Answers were provided using a 5-point Likert scale. There was also one open-ended question asking about what was missing from the MySAH tool., Results: In total, 66 consecutive patients with aneurysmal subarachnoid hemorrhage were informed about the online health community. Of 64 potential MySAH users, 26 patients gained access to MySAH, 20 of whom were willing to participate in the evaluation. Those who used the community were younger (P=.03) and in a better condition at discharge (P=.03). The patients were positive about MySAH's contribution to the quality of their care, but not to their quality of life. Most patients (18/20, 90%) reported that they would recommend the community to others in their position. Open suggestions on how to improve the tool included more frequent blogs, including by a rehabilitation specialist., Conclusions: This pilot study showed that the online health community, MySAH, has a beneficial effect on the aftercare of patients suffering from aSAH because it gives easy access to relevant information provided by peers or caregivers. Due to the variable clinical outcomes after aSAH, the tool will mainly be useful for a select group of patients (with a better clinical outcome).

We present a low cost microfluidic chip integrating 3D micro-chambers for the capture and the analysis of cells. This device has a simple design and a small footprint. It allows the implementation of standard biological protocols in a chip format with low volume consumption. The manufacturing process relies on hot-embossing of cyclo olefin copolymer, allowing the development of a low cost and robust device. A 3D design of microchannels was used to induce high flow velocity contrasts in the device and provide a selective immobilization. In narrow distribution channels, the liquid velocity induces a shear stress that overcomes adhesion forces and prevents cell immobilization or clogging. In large 3D chambers, the liquid velocity drops down below the threshold for cell attachment. The devices can be operated in a large range of input pressures and can even be handled manually using simple syringe or micropipette. Even at high flow injection rates, the 3D structures protect the captured cell from shear stress. To validate the performances of our device, we implemented immuno-fluorescence labeling and Fluorescence in Situ Hybridization (FISH) analysis on cancer cell lines and on a patient pleural effusion sample. FISH is a Food and Drug Administration approved cancer diagnostic technique that provides quantitative information about gene and chromosome aberration at the single cell level. It is usually considered as a long and fastidious test in medical diagnosis. This process can be easily implanted in our platform, and high resolution fluorescence imaging can be performed with reduced time and computer intensiveness. These results demonstrate the potential of this chip as a low cost, robust, and versatile tool adapted to complex and demanding protocols for medical diagnosis.