78 research outputs found

    A simple, rapid method to isolate salt glands for three-dimensional visualization, fluorescence imaging and cytological studies

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    <p>Abstract</p> <p>Background</p> <p>Some plants inhabiting saline environment remove salts via the salt glands embedded in the epidermal tissues. Cytological studies of salt glands will provide valuable information to our understanding of the secretory process. Previous studies on salt gland histology relied mainly on two-dimensional microscopic observations of microtome sections. Optical sectioning properties of confocal laser scanning microscope offer alternative approach for obtaining three-dimensional structural information of salt glands. Difficulty in light penetration through intact leaves and interference from neighbouring leaf cells, however, impede the acquiring of good optical salt gland sections and limit its applications in salt gland imaging. Freeing the glands from adjacent leaf tissues will allow better manipulations for three-dimensional imaging through confocal laser scanning microscopy.</p> <p>Results</p> <p>Here, we present a simple and fast method for the isolation of individual salt glands released from the interference of neighbouring cells. About 100-200 salt glands could be isolated from just one cm<sup>2 </sup>of <it>Avicennia </it><it>officinalis </it>leaf within hours and microscopic visualization of isolated salt glands was made possible within a day. Using these isolated glands, confocal laser scanning microscopic techniques could be applied and better resolution salt gland images could be achieved. By making use of their intrinsic fluorescent properties, optical sections of the gland cells could be acquired without the use of fluorescent probes and the corresponding three-dimensional images constructed. Useful cytological information of the salt gland cells could also be obtained through the applications of fluorescent dyes (e.g., LysoTracker<sup>® </sup>Red, FM<sup>®</sup>4-64, Texas Red<sup>®</sup>).</p> <p>Conclusions</p> <p>The study of salt glands directly at the glandular level are made possible with the successful isolation of these specialized structures. Preparation of materials for subsequent microscopic observations of salt glands could be achieved within a day. Potential applications of confocal fluorescence microscopic techniques could also be performed using these isolated glands. Experiments designed and targeted directly at the salt glands were explored and cytological information obtained herein could be further incorporated towards the understanding of the mechanism underlying secretion in plant salt glands.</p

    Examining the disability model from the International Classification of Functioning, Disability, and Health using a large data set of community-dwelling Malaysian older adults

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    Objective: This study examines the International Classification of Functioning, Disability, and Health model (ICF) using a data set of 2,563 community-dwelling elderly with disease-independent measures of mobility, physical activity, and social networking, to represent ICF constructs. Method: The relationship between chronic disease and disability (independent and dependent variables) was examined using logistic regression. To demonstrate variability in activity performance with functional impairment, graphing was used. The relationship between functional impairment, activity performance, and social participation was examined graphically and using ANOVA. The impact of cognitive deficits was quantified through stratifying by dementia. Results: Disability is strongly related to chronic disease (Wald 25.5, p < .001), functional impairment with activity performance (F = 34.2, p < .001), and social participation (F= 43.6, p < .001). With good function, there is considerable variability in activity performance (inter-quartile range [IQR] = 2.00), but diminishes with high impairment (IQR = 0.00) especially with cognitive deficits. Discussion: Environment modification benefits those with moderate functional impairment, but not with higher grades of functional loss

    MultiRes Attention Deep Learning Approach for Abdominal Fat Compartment Segmentation and Quantification

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    Global increase in obesity has led to alarming rise in co-morbidities leading to deteriorated quality of life. Obesity phenotyping benefits profiling and management of the condition but warrants accurate quantification of fat compartments. Manual quantification MR scans are time consuming and laborious. Hence, many studies rely on semi/automatic methods for quantification of abdominal fat compartments. We propose a MultiRes-Attention U-Net with hybrid loss function for segmentation of different abdominal fata compartments namely (i) Superficial subcutaneous adipose tissue (SSAT), (ii) Deep subcutaneous adipose tissue (DSAT), and (iii) Visceral adipose tissue (VAT) using abdominal MR scans. MultiRes block, ResAtt-Path, and attention gates can handle shape, scale, and heterogeneity in the data. Dataset involved MR scans from 190 community-dwelling older adults (mainly Chinese, 69.5% females) with mean age—67.85 ± 7.90 years), BMI 23.75 ± 3.65 kg/m2. Twenty-six datasets were manually segmented to generate the ground truth. Data augmentations were performed using MR data acquisition variations. Training and validation were performed on 105 datasets, while testing was conducted on 25 datasets. Median Dice scores were 0.97 for SSAT & DSAT and 0.96 for VAT, and mean Hausdorff distance was <5 mm for all the three fat compartments. Further, MultiRes-Attention U-Net was tested on a new 190 datasets (unseen during training; upper & lower abdomen scans with different resolution), which yielded accurate results. MultiRes-Attention U-Net significantly improved the performance over MultiResUNet, showed excellent generalization and holds promise for body-profiling in large cohort studies

    Dementia, Frailty and Aging

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    The number of older subjects is rapidly increasingly worldwide. As a consequence, the nature of clinical conditions is also changing. Traditional medicine and models of care have been based on the evaluation and treatment of single and usually acute conditions occurring in relatively young individuals. Today, the usual clinical manifestation of diseases is characterized by multiple and often chronic conditions affecting older people. In this scenario, frailty and dementia have been triggering special interest both in research and clinical settings due to their high prevalence, impact on the individual’s quality of life, and consequences for public health worldwide. These conditions aptly reflect the complexity of age-related pathological conditions, finding as causal factor a myriad of heterogeneous, interacting, and often still unclear pathophysiological processes. Indeed, their study is strongly affected by the difficulty to differentiate the effects of a normal aging process from eventual pathological deviations of the underlying systems. Their occurrence and trajectories over time are strongly affected by a wide array of factors and determinants that can be hardly attributed to the deficit/involvement of single biological systems and/or health domains. Moreover, environment and social factors also play a key role in the determination of phenotypes. The present Research Topic is aimed at widening our understanding of the frailty and dementia phenomena occurring with aging, in order to improve the clinical and public health approaches to these burdening conditions

    Development and validation of a multidimensional short version Zarit Burden Interview (ZBI-9) for caregivers of persons with cognitive impairment

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    Background: There is a lack of appreciation of the full dimensionality of the original 22-item Zarit Burden Interview (ZBI) in the development of short versions. Existing short versions are premised upon a 1-factor or 2-factor structure or statistical techniques for item selection. Thus, there is a need for ZBI short versions that considers the multidimensional constructs of role strain, personal strain, and worry about performance (WaP) during item selection to provide a more holistic and comprehensive evaluation. Purpose: To develop and validate a short version of ZBI through a combined quantitative and qualitative approach that incorporates the validated 4-factor structure of role strain demands; role strain-control; personal strain, and WaP. Patients: We studied 202 caregivers of patients with dementia (84.2%) or mild cognitive impairment (15.8%) attending a memory clinic in Singapore. Methods: Confirmatory factor analysis and qualitative considerations from expert consensus were used for item selection. Confirmatory factor analysis fit statistics support the 4-factor structure. The 9-item ZBI-9 showed good internal consistency (Cronbach’s α=0.87) and convergent validity with anxiety and depression (Pearson correlation: Hospital Anxiety and Depression sub-scales, r≥0.56, P<0.001; ZBI- 22, r=0.95, P<0.001). Using a cut-off score of ≥13, ZBI-9 displayed good discriminatory ability for depressive symptoms (area under curve=0.79, P<0.001; sensitivity=70%, specificity=75%). The ZBI-9 also displayed comparable performance to the 22-item full version and three 12-item short versions. Conclusion: The ZBI-9 is a multidimensional short-version assessment tool for caregivers of persons with dementia and mild cognitive impairment that is reliable, valid, and discriminates depressive symptoms.Published versionThe research was funded by the Ng Teng Fong Healthcare Innovative Program, Singapore (NTF_JUN2018_I_C1_C_02)

    Utility of the Clinical Dementia Rating in Asian Populations

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    Consistent with the worldwide demographic trend of population aging, dementia is expected to become a burgeoning public health problem in Asian populations. Thus, there is a pressing need for reliable and valid methods of dementia diagnosis and staging that are applicable in heterogeneous Asian populations. The Clinical Dementia Rating (CDR) is an informant-based global assessment scale with established reliability and validity that has been widely utilized as a severity-ranking scale in many studies of Asian populations. From a diagnostic standpoint, the CDR is congruent with the Diagnostic and Statistical Manual of Mental Disorders approach of dementia diagnosis. It exhibits excellent discriminatory ability in the very mild stages of dementia, a useful property that is germane to the surging interest in mild cognitive impairment and related concepts. Limitations of the CDR include its length of administration, reliance on clinical judgment and collateral source information, and relative insensitivity as a measure of change in interventional studies. Since the exercise of clinical judgment is inherent in scoring, CDR raters should be mindful of the influence of cultural factors on premorbid lifestyle, informant reliability and performance in certain CDR test items (especially those pertaining to the categories of judgment and problem solving, community, and home and hobbies). Thus, in future studies that involve the nascent use of the CDR in Asian populations, it is recommended that any transcultural adaptation of CDR items be described in detail and appropriate validation studies be carried out before adopting the CDR as a yardstick measure of assessment. The potential of adapted versions of the CDR in chronic care settings and advanced cases should be explored. An integrative approach, combining brief informant interview in conjunction with brief objective cognitive testing, could be a viable strategy for dementia screening in the clinical and research setting that warrants further evaluation in Asian populations
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