Characterizing the Biomechanical Exposures Associated with Common and High Demand Personal Support Worker Tasks

Background: The physical demands that personal support workers (PSWs) are exposed to are increasing as our population ages and our society is increasingly shifting to at-home care, resulting in increases in workload demands. However, PSWs are also developing high rates of musculoskeletal disorders (MSD) likely because of increased exposure to physical task demands. There is a need to intervene to protect these essential healthcare workers. Presently, little is known about the biomechanical exposure characteristics associated with PSW work tasks, especially within a home care setting. PSW work is highly dynamic and a wide range of tasks with different loading scenarios are completed. This means that the time-series exposure patterns are also likely varied over a work shift or work week, where this variation may be important when designing effective ergonomic interventions. As an example intervention strategy, workload management may be an effective approach to monitor, assess, and redistribute workload as needed to provide recovery windows to reduce and mitigate the accumulation of exposure. Real-time tracking and the continuous monitoring of PSW exposures, or surrogates, may assist in the assessment of injury risk. To better understand the biomechanical exposure characteristics associated with common PSW work tasks and to explore the potential utility of ratings of perceived exertion (RPE) as a potential surrogate measure to track PSW workload, this thesis aimed to address the following two objectives and corresponding research questions: Objectives: 1. Characterize biomechanical exposure metrics associated with the performance of common and highly demanding PSW work tasks. 2. Evaluate the relationship between RPE and the biomechanical exposure metrics. Research Questions: 1. What are the biomechanical exposures experienced by PSWs when performing simulated common and physically demanding work tasks? 2. What is the relationship between RPE and biomechanical exposure metrics (peak low back flexion angle, peak low back extensor moment, cumulative low back extensor moment) when performing common and physically demanding PSW work tasks? Methods: Twenty PSWs were recruited to complete 12 work tasks within a laboratory setting, where full body kinematics and hand forces were collected for all trials. A whole-body top-down rigid link modelling approach was used to calculate biomechanical exposure metrics. Peak low back flexion angle along with peak and cumulative extensor moments were calculated. Linear regressions tested for relationships between post-task RPE scores and 1) peak low back angles, 2) peak low back extensor moment, and 3) cumulative low back extensor moment at an individual level, where corresponding regression statistics from each participant were the aggregated at the group level. Results: Patient handling tasks, such as transfers and repositioning tasks, had the highest peak extensor moments (ranging from 115-157 Nm), while having the lowest cumulative moment values (1329 – 4552 Nm*s). In contrast, patient care tasks such as bathing, dressing/undressing, and compression stocking application, had the highest cumulative extensor moment values (2623 – 8089 Nm*s) and lower peak moments (92 – 107 Nm). Additionally, patient care tasks took the longest to complete and required participants to frequently adopt moderate (20-45 degrees) to severe (>45 degrees) levels of low back flexion. A significant moderate positive relationship was found between RPE scores and cumulative low back extensor moment (p<0.05, R=0.60). No significant relationship was found between RPE scores and both peak low back flexion angle (p<0.05, R=0.16) and peak low back extensor moment (p<0.05, R=-0.13). Discussion: The biomechanical exposure characteristics of PSW work are task dependent. Patient handling tasks subjected PSWs to high peak loads for brief periods of time. Patient care tasks, on the other hand, imposed lower magnitudes of loading for extended time duration. It is well established that low back injury pathways are different when loading is high, but brief, relative to lower in magnitude, but sustained. As such, it appears that groupings of tasks may be of more interest to consider and intervene from the perspective of reducing high peak loads, where others might be better viewed from a cumulative load perspective. Therefore, in the design and development of any effective ergonomic interventions, it may be important to consider task-specific loading profiles and how they may influence injury development based on corresponding pathways. Task characterization as quantified within the current study can serve as a foundation to inform workflow management and patient scheduling decisions in an attempt to optimize temporal aspects of loading. RPE scores could be used as a surrogate for cumulative low back extensor moment, which may have utility as an easy-to-implement assessment tool to track the accumulation of spine extensor moment loading. These findings can inform additional work to evaluate how real-time RPE tracking functions within real work settings and can explore other metrics that might help to better monitor and track exposures during short duration, high load tasks

Understanding the biology of human interstitial cells of Cajal in gastrointestinal motility

Millions of patients worldwide suffer from gastrointestinal (GI) motility disorders such as gastroparesis. These disorders typically include debilitating symptoms, such as chronic nausea and vomiting. As no cures are currently available, clinical care is limited to symptom management, while the underlying causes of impaired GI motility remain unaddressed. The efficient movement of contents through the GI tract is facilitated by peristalsis. These rhythmic slow waves of GI muscle contraction are mediated by several cell types, including smooth muscle cells, enteric neurons, telocytes, and specialised gut pacemaker cells called interstitial cells of Cajal (ICC). As ICC dysfunction or loss has been implicated in several GI motility disorders, ICC represent a potentially valuable therapeutic target. Due to their availability, murine ICC have been extensively studied at the molecular level using both normal and diseased GI tissue. In contrast, relatively little is known about the biology of human ICC or their involvement in GI disease pathogenesis. Here, we demonstrate human gastric tissue as a source of primary human cells with ICC phenotype. Further characterisation of these cells will provide new insights into human GI biology, with the potential for developing novel therapies to address the fundamental causes of GI dysmotility

Gastric Alimetry® test interpretation in gastroduodenal disorders : review and recommendations

Chronic gastroduodenal symptoms are prevalent worldwide, and there is a need for new diagnostic and treatment approaches. Several overlapping processes may contribute to these symptoms, including gastric dysmotility, hypersensitivity, gut–brain axis disorders, gastric outflow resistance, and duodenal inflammation. Gastric Alimetry® (Alimetry, New Zealand) is a non-invasive test for evaluating gastric function that combines body surface gastric mapping (high-resolution electrophysiology) with validated symptom profiling. Together, these complementary data streams enable important new clinical insights into gastric disorders and their symptom correlations, with emerging therapeutic implications. A comprehensive database has been established, currently comprising > 2000 Gastric Alimetry tests, including both controls and patients with various gastroduodenal disorders. From studies employing this database, this paper presents a systematic methodology for Gastric Alimetry test interpretation, together with an extensive supporting literature review. Reporting is grouped into four sections: Test Quality, Spectral Analysis, Symptoms, and Conclusions. This review compiles, assesses, and evaluates each of these aspects of test assessment, with discussion of relevant evidence, example cases, limitations, and areas for future work. The resultant interpretation methodology is recommended for use in clinical practice and research to assist clinicians in their use of Gastric Alimetry as a diagnostic aid and is expected to continue to evolve with further development

Transcriptome and proteome profiling of primary human gastric interstitial cells of Cajal predicts pacemaker networks

Background/Aims Interstitial cells of Cajal (ICC) are specialized gastrointestinal (GI) pacemaker cells required for normal GI motility. Dysfunctions in ICC have been reported in patients with GI motility disorders, such as gastroparesis, who exhibit debilitating symptoms and greatly reduced quality of life. While the proteins, calcium-activated chloride channel anoctamin-1 (ANO1) and the receptor tyrosine kinase (KIT), are known to be expressed by human ICC, relatively little is known about the broad molecular circuitry underpinning human ICC functions. The present study therefore investigates the transcriptome and proteome of ANO1-expressing, KITlow/CD45–/CD11B– ICC obtained from primary human gastric tissue. Methods Excess human gastric tissue resections were obtained from sleeve gastrectomy patients. ICC were purified using fluorescence-activated cell sorting (FACSorting). Then, ICC were characterized by using immunofluorescence, real-time polymerase chain reaction, RNA-sequencing and mass spectrometry. Results Compared to unsorted cells, real-time polymerase chain reaction showed the KITlow/CD45–/CD11B– ICC had: a 9-fold (P 10-fold, P 4-fold, P < 0.05). RNA-sequencing and gene ontology analyses of the KITlow/ CD45–/CD11B– cells revealed a transcriptional profile consistent with ICC function. Similarly, mass spectrometry analyses of the KITlow/ CD45–/CD11B– cells presented a proteomic profile consistent with ICC activities. STRING-based protein interaction analyses using the RNA-sequencing and proteomic datasets predicted protein networks consistent with ICC-associated pacemaker activity and ion transport. Conclusion These new and complementary datasets provide a valuable molecular framework for further understanding how ICC pacemaker activity regulates smooth muscle contraction in both normal GI tissue and GI motility disorders

How parents perceive and feel about participation in community activities: The comparison between parents of preschoolers with and without autism spectrum disorders

The present study compared how parents of preschoolers with and without Autism Spectrum Disorders (ASD) perceived and felt about participation in community activities. A questionnaire survey was conducted with 380 Hong Kong parents of preschoolers with ASD and 214 Hong Kong parents of preschoolers without ASD. The two groups were not different in their willingness and frequency of participation in community activities. However, the psychological processes underneath their willingness were very different. Among the parents of preschoolers with ASD, their willingness was associated with how they perceived the difficulty and importance of the participation and what emotions they experienced during the activities. This pattern of association was not evident among the parents of preschoolers without ASD. Copyright © The Author(s), 2010.published_or_final_versio

BRCA1 and BRCA2 Germline Mutations in Malaysian Women with Early-Onset Breast Cancer without a Family History

BACKGROUND: In Asia, breast cancer is characterised by an early age of onset: In Malaysia, approximately 50% of cases occur in women under the age of 50 years. A proportion of these cases may be attributable, at least in part, to genetic components, but to date, the contribution of genetic components to breast cancer in many of Malaysia's ethnic groups has not been well-characterised. METHODOLOGY: Given that hereditary breast carcinoma is primarily due to germline mutations in one of two breast cancer susceptibility genes, BRCA1 and BRCA2, we have characterised the spectrum of BRCA mutations in a cohort of 37 individuals with early-onset disease (<or=40 years) and no reported family history. Mutational analysis of BRCA1 and BRCA2 was conducted by full sequencing of all exons and intron-exon junctions. CONCLUSIONS: Here, we report a total of 14 BRCA1 and 17 BRCA2 sequence alterations, of which eight are novel (3 BRCA1 and 5 BRCA2). One deleterious BRCA1 mutation and 2 deleterious BRCA2 mutations, all of which are novel mutations, were identified in 3 of 37 individuals. This represents a prevalence of 2.7% and 5.4% respectively, which is consistent with other studies in other Asian ethnic groups (4-9%)

Evolutionary Changes in the Complexity of the Tectum of Nontetrapods: A Cladistic Approach

Background: The tectum is a structure localized in the roof of the midbrain in vertebrates, and is taken to be highly conserved in evolution. The present article assessed three hypotheses concerning the evolution of lamination and citoarchitecture of the tectum of nontetrapod animals: 1) There is a significant degree of phylogenetic inertia in both traits studied (number of cellular layers and number of cell classes in tectum); 2) Both traits are positively correlated accross evolution after correction for phylogeny; and 3) Different developmental pathways should generate different patterns of lamination and cytoarchitecture. Methodology/Principal Findings: The hypotheses were tested using analytical-computational tools for phylogenetic hypothesis testing. Both traits presented a considerably large phylogenetic signal and were positively associated. However, no difference was found between two clades classified as per the general developmental pathways of their brains. Conclusions/Significance: The evidence amassed points to more variation in the tectum than would be expected by phylogeny in three species from the taxa analysed; this variation is not better explained by differences in the main course of development, as would be predicted by the developmental clade hypothesis. Those findings shed new light on th

Cell Lineage and Regional Identity of Cultured Spinal Cord Neural Stem Cells and Comparison to Brain-Derived Neural Stem Cells

Neural stem cells (NSCs) can be isolated from different regions of the central nervous system. There has been controversy whether regional differences amongst stem and progenitor cells are cell intrinsic and whether these differences are maintained during expansion in culture. The identification of inherent regional differences has important implications for the use of these cells in neural repair. Here, we compared NSCs derived from the spinal cord and embryonic cortex. We found that while cultured cortical and spinal cord derived NSCs respond similarly to mitogens and are equally neuronogenic, they retain and maintain through multiple passages gene expression patterns indicative of the region from which they were isolated (e.g Emx2 and HoxD10). Further microarray analysis identified 229 genes that were differentially expressed between cortical and spinal cord derived neurospheres, including many Hox genes, Nuclear receptors, Irx3, Pace4, Lhx2, Emx2 and Ntrk2. NSCs in the cortex express LeX. However, in the embryonic spinal cord there are two lineally related populations of NSCs: one that expresses LeX and one that does not. The LeX negative population contains few markers of regional identity but is able to generate LeX expressing NSCs that express markers of regional identity. LeX positive cells do not give rise to LeX-negative NSCs. These results demonstrate that while both embryonic cortical and spinal cord NSCs have similar self-renewal properties and multipotency, they retain aspects of regional identity, even when passaged long-term in vitro. Furthermore, there is a population of a LeX negative NSC that is present in neurospheres derived from the embryonic spinal cord but not the cortex

ENIGMA-Sleep:Challenges, opportunities, and the road map

Neuroimaging and genetics studies have advanced our understanding of the neurobiology of sleep and its disorders. However, individual studies usually have limitations to identifying consistent and reproducible effects, including modest sample sizes, heterogeneous clinical characteristics and varied methodologies. These issues call for a large-scale multi-centre effort in sleep research, in order to increase the number of samples, and harmonize the methods of data collection, preprocessing and analysis using pre-registered well-established protocols. The Enhancing NeuroImaging Genetics through Meta-Analysis (ENIGMA) consortium provides a powerful collaborative framework for combining datasets across individual sites. Recently, we have launched the ENIGMA-Sleep working group with the collaboration of several institutes from 15 countries to perform large-scale worldwide neuroimaging and genetics studies for better understanding the neurobiology of impaired sleep quality in population-based healthy individuals, the neural consequences of sleep deprivation, pathophysiology of sleep disorders, as well as neural correlates of sleep disturbances across various neuropsychiatric disorders. In this introductory review, we describe the details of our currently available datasets and our ongoing projects in the ENIGMA-Sleep group, and discuss both the potential challenges and opportunities of a collaborative initiative in sleep medicine