23 results on '"Lai ES"'
Search Results
2. A Geospatial Analysis of Health, Mental Health, and Stressful Community Contexts in Los Angeles County.
- Author
-
Robles B, Thomas CS, Lai ES, and Kuo T
- Subjects
- California epidemiology, Health Services Accessibility, Humans, Socioeconomic Factors, Chronic Disease epidemiology, Mental Disorders epidemiology, Stress, Physiological
- Abstract
Introduction: Despite numerous federal investments, chronic disease continues to disproportionately affect certain communities across the United States. Understanding the regional distribution (including any overlaps) of factors that extend beyond built and food environments, especially factors that may adversely affect chronic disease-related behaviors, is important. This case study of Los Angeles County's geospatial landscape sought to address these gaps in research and practice., Methods: We examined the distributions and geographic overlaps between economic hardship, psychological distress, soda consumption, and availability of publicly funded mental health facilities in 8 Service Planning Areas in Los Angeles County. We categorized the geospatial presence of each variable as low, intermediate, or high. We imported all data, collected during 2014-2018, into ArcGIS Pro version 2.3.3 to create 5 bivariate choropleth maps., Results: Levels of economic hardship were not equally distributed across communities; the county was characterized by intermediate levels of soda consumption and psychological distress. Most areas had low or intermediate availability of publicly funded mental health facilities. We also found some discordance between psychological distress and availability of publicly funded mental health facilities, and between economic hardship and availability of these facilities., Conclusion: The need exists to address disparities in economic hardship and to increase access to publicly funded mental health supports and providers in Los Angeles County. The information collected in this case study has policy implications for health, public health, and mental health services planning at the local level.
- Published
- 2019
- Full Text
- View/download PDF
3. A Digital Game and School-Based Intervention for Students in Hong Kong: Quasi-Experimental Design.
- Author
-
Shum AK, Lai ES, Leung WG, Cheng MN, Wong HK, So SW, Law YW, and Yip PS
- Subjects
- Adolescent, Child, Female, Hong Kong, Humans, Male, Research Design, Video Games, Health Promotion methods, Schools trends
- Abstract
Background: In Hong Kong, with an increasing number of children experiencing mental health issues, there is a need to not only develop innovative interventions but also develop comprehensive prevention interventions so as to reduce their anxiety symptoms and enhance their emotional management and interpersonal relationships., Objective: The aim of this study was to determine the effectiveness of The Adventures of DoReMiFa, an integration model of the cognitive-behavioral approach and positive psychology by using digital game-based and school-based mental health enhancement intervention to magnify the social and emotional health and well-being of the school children in Hong Kong aged 9 to 11 years., Methods: A quasi-experimental design method was used to evaluate this digital game and school-based intervention. The Adventures of DoReMiFa was piloted in 4 primary schools where students were allocated to either an intervention or a control group. The participants were assessed at pre- and postintervention with a 6-month follow-up measuring their mental health knowledge, levels of anxiety symptoms, positive and negative thinking, perspective-taking, and self-esteem., Results: A total of 459 primary school students from 4 primary schools participated in the study. The response rate on the questionnaires answered on the Web was up to 85.1% (391/459). Compared with the control group, the intervention group was found to have significant association with improved mental health knowledge at the time immediately after the intervention (beta=.46; P=.01) and in the 6-month postintervention period (beta=.66; P<.001); for perspective-taking, the intervention group had exhibited a significant improvement 6 months after the completion of the universal program (beta=1.50; P=.03). The intervention, however, was found not to be effective in reducing the rates of anxiety symptoms and negative thinking among the participating students., Conclusions: The Adventures of DoReMiFa, an integration of a digital game-based and school-based mental health enhancement intervention, was shown to be effective in elevating the knowledge of mental health and promoting perspective-taking in the primary school students of Hong Kong. Although there was insufficient evidence to support a reduction in symptoms of anxiety and negative automatic thoughts, the overall results were still encouraging in that a preventive effect was found, indicating that the program has the potential to enhance the mental well-being of schoolchildren. It also suggests that knowledge enhancement may not necessarily lead to behavior change, and more focused effort may be needed to achieve the translation. The implications and limitations of this study and suggestions for future research were also discussed., (©Angie KY Shum, Eliza SY Lai, Wing Gi Leung, Mabel NS Cheng, Ho Kit Wong, Sam WK So, Yik Wa Law, Paul SF Yip. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 05.04.2019.)
- Published
- 2019
- Full Text
- View/download PDF
4. Higher pricing of fresh produce is more likely in SNAP-Ed eligible neighborhoods when adjacent non-program eligible neighborhoods are mixed income.
- Author
-
Jewell MP, Lai ES, Thompson J, Fox M, and Kuo T
- Abstract
This analysis describes the socioeconomic attributes of neighborhoods adjacent to low-income neighborhoods with ≥50% of households that are Supplemental Nutrition Assistance Program Education (SNAP-Ed) eligible. It compares the pricing, availability, and quality of fresh produce between these neighborhoods in Los Angeles County. The Los Angeles County Department of Public Health utilized 2013-2014 community-level data from the Communities of Excellence in Nutrition, Physical Activity and Obesity Prevention (CX3) Project to examine the geographic patterns of fresh produce purchases and accessibility in SNAP-Ed eligible census tracts. Community indicators collected by CX3 included information on pricing, availability, and quality of fruits and vegetables from grocery stores (n = 108) in these eligible neighborhoods (n = 21). Correlation statistics were generated to explore the effects of adjacent neighborhoods' socioeconomic status on fruit and vegetable pricing, availability, and quality in the selected neighborhoods ("CX3 neighborhoods"). Poverty data were obtained from the United States Census' American Community Survey. Residents of CX3 neighborhoods that were surrounded by mixed income neighborhoods paid 43% more for fresh produce than CX3 neighborhoods surrounded by other similarly low-income neighborhoods (median produce price, $1.50 versus $1.05). Study results suggest that while quality of produce remains an issue, it is the higher pricing of fresh produce in CX3 neighborhoods - i.e., in the presence of other surrounding mixed income neighborhoods (those with relatively higher income) - that appeared to potentiate food access barriers. Future SNAP-Ed efforts should take this pricing pattern under consideration when designing, planning, and/or implementing nutrition-related programs in these neighborhoods.
- Published
- 2019
- Full Text
- View/download PDF
5. Vagus Nerve Stimulation Enhances Stable Plasticity and Generalization of Stroke Recovery.
- Author
-
Meyers EC, Solorzano BR, James J, Ganzer PD, Lai ES, Rennaker RL 2nd, Kilgard MP, and Hays SA
- Subjects
- Animals, Disease Models, Animal, Female, Hindlimb pathology, Hindlimb physiopathology, Motor Cortex physiology, Muscle Strength, Rats, Rats, Sprague-Dawley, Stroke pathology, Motor Cortex physiopathology, Neuronal Plasticity, Stroke physiopathology, Stroke therapy, Vagus Nerve Stimulation
- Abstract
Background and Purpose: Chronic impairment of the arm and hand is a common consequence of stroke. Animal and human studies indicate that brief bursts of vagus nerve stimulation (VNS) in conjunction with rehabilitative training improve recovery of motor function after stroke. In this study, we tested whether VNS could promote generalization, long-lasting recovery, and structural plasticity in motor networks., Methods: Rats were trained on a fully automated, quantitative task that measures forelimb supination. On task proficiency, unilateral cortical and subcortical ischemic lesions were administered. One week after ischemic lesion, rats were randomly assigned to receive 6 weeks of rehabilitative training on the supination task with or without VNS. Rats then underwent 4 weeks of testing on a task assessing forelimb strength to test generalization of recovery. Finally, the durability of VNS benefits was tested on the supination task 2 months after the cessation of VNS. After the conclusion of behavioral testing, viral tracing was performed to assess synaptic connectivity in motor networks., Results: VNS enhances plasticity in corticospinal motor networks to increase synaptic connectivity to musculature of the rehabilitated forelimb. Adding VNS more than doubled the benefit of rehabilitative training, and the improvements lasted months after the end of VNS. Pairing VNS with supination training also significantly improved performance on a similar, but untrained task that emphasized volitional forelimb strength, suggesting generalization of forelimb recovery., Conclusions: This study provides the first evidence that VNS paired with rehabilitative training after stroke (1) doubles long-lasting recovery on a complex task involving forelimb supination, (2) doubles recovery on a simple motor task that was not paired with VNS, and (3) enhances structural plasticity in motor networks., (© 2018 American Heart Association, Inc.)
- Published
- 2018
- Full Text
- View/download PDF
6. Majority of flat epithelial atypia diagnosed on biopsy do not require surgical excision.
- Author
-
Chan PMY, Chotai N, Lai ES, Sin PY, Chen J, Lu SQ, Goh MH, Chong BK, Ho BCS, and Tan EY
- Subjects
- Adult, Aged, Animals, Biopsy, Breast diagnostic imaging, Breast Neoplasms diagnosis, Breast Neoplasms surgery, Calcinosis diagnostic imaging, Carcinoma, Intraductal, Noninfiltrating diagnosis, Carcinoma, Intraductal, Noninfiltrating surgery, Female, Follow-Up Studies, Humans, Mammography, Middle Aged, Neoplasm Grading, Retrospective Studies, Young Adult, Breast pathology, Breast Neoplasms pathology, Carcinoma, Intraductal, Noninfiltrating pathology, Epithelial Cells pathology
- Abstract
Background: Borderline risk lesions such as flat epithelial atypia (FEA) are increasingly being diagnosed on biopsy. The need for surgery is being debated. In this study, we determined the frequency of histological upgrade following a diagnosis of FEA on biopsy and evaluated potential predictive factors., Methods: Retrospective review was done of 194 women who underwent biopsy of indeterminate lesions (total 195 lesions) that were diagnosed as FEA. The review covered a 10-year period. Cases where malignancy was also present together with FEA within the same biopsy cores were excluded., Results: Lesions diagnosed as FEA on biopsy were mostly asymptomatic and presented as microcalcifications on mammogram. Flat epithelial atypia was the only abnormality detected in one-third of cases, was associated with a benign or another borderline lesion in another third and was associated with atypical ductal hyperplasia (ADH) in another third. Six patients (3.1%) were later found to have ductal carcinoma-in-situ (DCIS) at surgery. The presence of ADH in the biopsy was the only predictor of histological upgrade to malignancy (P = 0.04, OR 11.24, 95% CI 1.10 - 115.10), and was present in 5 of the 6 patients. Surgery was advised in the last patient because of radiology-pathology discordance. Thirty-six lesions (18.5%) were not excised and no interval progression or malignancy was found on follow up., Conclusion: Histological upgrade to malignancy was uncommon in lesions found on biopsy to be FEA. Non-operative management of biopsy-proven FEA can be considered in the absence of ADH and radiology-pathology discordance., (Copyright © 2017 Elsevier Ltd. All rights reserved.)
- Published
- 2018
- Full Text
- View/download PDF
7. Evaluation of a Digital Game-Based Learning Program for Enhancing Youth Mental Health: A Structural Equation Modeling of the Program Effectiveness.
- Author
-
Huen JM, Lai ES, Shum AK, So SW, Chan MK, Wong PW, Law YW, and Yip PS
- Abstract
Background: Digital game-based learning (DGBL) makes use of the entertaining power of digital games for educational purposes. Effectiveness assessment of DGBL programs has been underexplored and no attempt has been made to simultaneously model both important components of DGBL: learning attainment (ie, educational purposes of DGBL) and engagement of users (ie, entertaining power of DGBL) in evaluating program effectiveness., Objective: This study aimed to describe and evaluate an Internet-based DGBL program, Professor Gooley and the Flame of Mind, which promotes mental health to adolescents in a positive youth development approach. In particular, we investigated whether user engagement in the DGBL program could enhance their attainment on each of the learning constructs per DGBL module and subsequently enhance their mental health as measured by psychological well-being., Methods: Users were assessed on their attainment on each learning construct, psychological well-being, and engagement in each of the modules. One structural equation model was constructed for each DGBL module to model the effect of users' engagement and attainment on the learning construct on their psychological well-being., Results: Of the 498 secondary school students that registered and participated from the first module of the DGBL program, 192 completed all 8 modules of the program. Results from structural equation modeling suggested that a higher extent of engagement in the program activities facilitated users' attainment on the learning constructs on most of the modules and in turn enhanced their psychological well-being after controlling for users' initial psychological well-being and initial attainment on the constructs., Conclusions: This study provided evidence that Internet intervention for mental health, implemented with the technologies and digital innovations of DGBL, could enhance youth mental health. Structural equation modeling is a promising approach in evaluating the effectiveness of DGBL programs., Competing Interests: Conflicts of Interest: None declared.
- Published
- 2016
- Full Text
- View/download PDF
8. The Effectiveness and Sustainability of a Universal School-Based Programme for Preventing Depression in Chinese Adolescents: A Follow-Up Study Using Quasi-Experimental Design.
- Author
-
Lai ES, Kwok CL, Wong PW, Fu KW, Law YW, and Yip PS
- Subjects
- Adolescent, Anxiety prevention & control, Anxiety psychology, Depression psychology, Female, Follow-Up Studies, Health Knowledge, Attitudes, Practice, Humans, Male, Patient Acceptance of Health Care statistics & numerical data, Social Support, Stress, Psychological prevention & control, Stress, Psychological psychology, Depression prevention & control, Program Evaluation, Schools statistics & numerical data
- Abstract
Background: A pilot study about the effectiveness of a universal school-based programme, "The Little Prince is Depressed", for preventing depression in Chinese adolescents in Hong Kong was conducted and reported previously. This study used a larger sample to examine the effectiveness and sustainability of the programme., Methods: This study used quasi-experimental design. Twelve schools enrolled in "The Little Prince is Depressed" programme either as an intervention or a control condition. The intervention schools carried out the 12-session programme in two phases: the professional-led first phase and the teacher-led second phase. All participants were required to complete a questionnaire at three time points measuring their (1) depressive, anxiety, and stress levels; (2) knowledge of mental health; (3) attitudes towards mental illness; (4) perceived social support; and (5) help-seeking behaviours., Results: A total of 3,391 students participated in the study. The level of depressive symptoms did not reduce significantly at post-intervention; however, a delayed effect was observed at follow-up assessment for the participants of the teacher-led group in reducing anxiety and stress levels. Also, the knowledge of mental health and attitudes towards mental illness of the intervention-group participants significantly improved at post-test, and the outcomes were maintained at 4 to 5 months after the intervention in both the professional-led and the teacher-led conditions (p<.05). A preference among schoolchildren for whom to seek help from was identified., Conclusions: The universal depression prevention programme was effective in enhancing knowledge of mental health and promoting a more positive attitude towards mental illness among adolescents in Hong Kong. In particular, the teacher-led group showed better outcomes than the professional-led group in reducing students' anxiety and stress at follow-up period. The programme can achieve sustainability in schools if teachers are provided with adequate support.
- Published
- 2016
- Full Text
- View/download PDF
9. Nanoscale Patterning of Extracellular Matrix Alters Endothelial Function under Shear Stress.
- Author
-
Nakayama KH, Surya VN, Gole M, Walker TW, Yang W, Lai ES, Ostrowski MA, Fuller GG, Dunn AR, and Huang NF
- Subjects
- Blood Vessels chemistry, Cell Movement, Cell Proliferation, Collagen chemistry, Endothelial Cells metabolism, Extracellular Matrix metabolism, Humans, Nanofibers chemistry, Tissue Engineering, Cell Tracking, Endothelial Cells chemistry, Extracellular Matrix chemistry, Stress, Mechanical
- Abstract
The role of nanotopographical extracellular matrix (ECM) cues in vascular endothelial cell (EC) organization and function is not well-understood, despite the composition of nano- to microscale fibrillar ECMs within blood vessels. Instead, the predominant modulator of EC organization and function is traditionally thought to be hemodynamic shear stress, in which uniform shear stress induces parallel-alignment of ECs with anti-inflammatory function, whereas disturbed flow induces a disorganized configuration with pro-inflammatory function. Since shear stress acts on ECs by applying a mechanical force concomitant with inducing spatial patterning of the cells, we sought to decouple the effects of shear stress using parallel-aligned nanofibrillar collagen films that induce parallel EC alignment prior to stimulation with disturbed flow resulting from spatial wall shear stress gradients. Using real time live-cell imaging, we tracked the alignment, migration trajectories, proliferation, and anti-inflammatory behavior of ECs when they were cultured on parallel-aligned or randomly oriented nanofibrillar films. Intriguingly, ECs cultured on aligned nanofibrillar films remained well-aligned and migrated predominantly along the direction of aligned nanofibrils, despite exposure to shear stress orthogonal to the direction of the aligned nanofibrils. Furthermore, in stark contrast to ECs cultured on randomly oriented films, ECs on aligned nanofibrillar films exposed to disturbed flow had significantly reduced inflammation and proliferation, while maintaining intact intercellular junctions. This work reveals fundamental insights into the importance of nanoscale ECM interactions in the maintenance of endothelial function. Importantly, it provides new insight into how ECs respond to opposing cues derived from nanotopography and mechanical shear force and has strong implications in the design of polymeric conduits and bioengineered tissues.
- Published
- 2016
- Full Text
- View/download PDF
10. Working memory impairment and its associated sleep-related respiratory parameters in children with obstructive sleep apnea.
- Author
-
Lau EY, Choi EW, Lai ES, Lau KN, Au CT, Yung WH, and Li AM
- Subjects
- Case-Control Studies, Child, China, Female, Humans, Male, Memory Disorders diagnosis, Neuropsychological Tests, Polysomnography, Respiratory Function Tests, Sleep Apnea, Obstructive complications, Sleep Apnea, Obstructive physiopathology, Memory Disorders etiology, Memory Disorders physiopathology, Memory, Short-Term physiology, Sleep Apnea, Obstructive psychology
- Abstract
Study Objective: Working memory deficits in children with obstructive sleep apnea (OSA) have been reported in previous studies, but the results were inconclusive. This study tried to address this issue by delineating working memory functions into executive processes and storage/maintenance components based on Baddeley's working memory model., Methods: Working memory and basic attention tasks were administered on 23 OSA children aged 8-12 years and 22 age-, education-, and general cognitive functioning-matched controls. Data on overnight polysomnographic sleep study and working memory functions were compared between the two groups. Associations between respiratory-related parameters and cognitive performance were explored in the OSA group., Results: Compared with controls, children with OSA had poorer performance on both tasks of basic storage and central executive components in the verbal domain of working memory, above and beyond basic attention and processing speed impairments; such differences were not significant in the visuo-spatial domain. Moreover, correlational analyses and hierarchical regression analyses further suggested that obstructive apnea-hypopnea index (OAHI) and oxygen saturation (SpO2) nadir were associated with verbal working memory performance, highlighting the potential pathophysiological mechanisms of OSA-induced cognitive deficits., Conclusions: Verbal working memory impairments associated with OSA may compromise children's learning potentials and neurocognitive development. Early identification of OSA and assessment of the associated neurocognitive deficits are of paramount importance. Reversibility of cognitive deficits after treatment would be a critical outcome indicator., (Copyright © 2015 Elsevier B.V. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
11. Bilayered vascular graft derived from human induced pluripotent stem cells with biomimetic structure and function.
- Author
-
Nakayama KH, Joshi PA, Lai ES, Gujar P, Joubert LM, Chen B, and Huang NF
- Subjects
- Actins metabolism, Anisotropy, Cell Adhesion, Collagen chemistry, Cytoskeleton metabolism, Endothelial Cells metabolism, Humans, Inflammation, Microscopy, Electron, Scanning, Monocytes cytology, Monocytes metabolism, Muscle, Smooth cytology, Myocytes, Smooth Muscle cytology, Platelet Endothelial Cell Adhesion Molecule-1 metabolism, Tissue Engineering methods, Tissue Scaffolds chemistry, Biomimetics, Induced Pluripotent Stem Cells cytology, Vascular Grafting methods
- Abstract
Background: We developed an aligned bi-layered vascular graft derived from human induced pluripotent stem cells (iPSCs) that recapitulates the cellular composition, orientation, and anti-inflammatory function of blood vessels., Materials & Methods: The luminal layer consisted of longitudinal-aligned nanofibrillar collagen containing primary endothelial cells (ECs) or iPSC-derived ECs (iPSC-ECs). The outer layer contained circumferentially oriented nanofibrillar collagen with primary smooth muscle cells (SMCs) or iPSC-derived SMCs(iPSC-SMCs)., Results: On the aligned scaffolds, cells organized F-actin assembly within 8º from the direction of nanofibrils. When compared to randomly-oriented scaffolds, EC-seeded aligned scaffolds had significant reduced inflammatory response, based on adhesivity to monocytes., Conclusion: This study highlights the importance of anisotropic scaffolds in directing cell form and function, and has therapeutic significance as physiologically relevant blood vessels., Competing Interests: Financial & competing interests disclosureThis study was supported in part by grants from the US NIH (R00HL098688 and EB020235-01 to NFH), Merit Review Award (1I01BX002310) from the Department of Veterans Affairs Biomedical Laboratory Research and Development to NF Huang, the Stanford Chemistry Engineering & Medicine for Human Health to NF Huang, the Stanford Cardiovascular Institute to NF Huang and the California Institute of Regenerative Medicine (CIRM Early Translational Research Award TR3-05569) to B Chen. KH Nakayama was supported by fellowships from the National Heart, Lung and Blood Institute (1T32HL098049) and the American Heart Association (15POST25560045). PA Joshi was supported by a fellowship from the San José State University Consortium for Stem Cell Internships in Laboratory-based Learning. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.No writing assistance was utilized in the production of this manuscript.
- Published
- 2015
- Full Text
- View/download PDF
12. Evaluation of a Web-based social network electronic game in enhancing mental health literacy for young people.
- Author
-
Li TM, Chau M, Wong PW, Lai ES, and Yip PS
- Subjects
- Adolescent, Adult, Humans, Learning, Motivation, Pilot Projects, Young Adult, Health Literacy, Internet, Mental Health, Motor Activity, Social Support
- Abstract
Background: Internet-based learning programs provide people with massive health care information and self-help guidelines on improving their health. The advent of Web 2.0 and social networks renders significant flexibility to embedding highly interactive components, such as games, to foster learning processes. The effectiveness of game-based learning on social networks has not yet been fully evaluated., Objectives: The aim of this study was to assess the effectiveness of a fully automated, Web-based, social network electronic game on enhancing mental health knowledge and problem-solving skills of young people. We investigated potential motivational constructs directly affecting the learning outcome. Gender differences in learning outcome and motivation were also examined., Methods: A pre/posttest design was used to evaluate the fully automated Web-based intervention. Participants, recruited from a closed online user group, self-assessed their mental health literacy and motivational constructs before and after completing the game within a 3-week period. The electronic game was designed according to cognitive-behavioral approaches. Completers and intent-to-treat analyses, using multiple imputation for missing data, were performed. Regression analysis with backward selection was employed when examining the relationship between knowledge enhancement and motivational constructs., Results: The sample included 73 undergraduates (42 females) for completers analysis. The gaming approach was effective in enhancing young people's mental health literacy (d=0.65). The finding was also consistent with the intent-to-treat analysis, which included 127 undergraduates (75 females). No gender differences were found in learning outcome (P=.97). Intrinsic goal orientation was the primary factor in learning motivation, whereas test anxiety was successfully alleviated in the game setting. No gender differences were found on any learning motivation subscales (P>.10). We also found that participants' self-efficacy for learning and performance, as well as test anxiety, significantly affected their learning outcomes, whereas other motivational subscales were statistically nonsignificant., Conclusions: Electronic games implemented through social networking sites appear to effectively enhance users' mental health literacy.
- Published
- 2013
- Full Text
- View/download PDF
13. Spatial patterning of endothelium modulates cell morphology, adhesiveness and transcriptional signature.
- Author
-
Huang NF, Lai ES, Ribeiro AJ, Pan S, Pruitt BL, Fuller GG, and Cooke JP
- Subjects
- Cells, Cultured, Collagen metabolism, Fluorescent Antibody Technique, Humans, Oligonucleotide Array Sequence Analysis, Cell Adhesion, Endothelium, Vascular cytology, Transcription, Genetic
- Abstract
Microscale and nanoscale structures can spatially pattern endothelial cells (ECs) into parallel-aligned organization, mimicking their cellular alignment in blood vessels exposed to laminar shear stress. However, the effects of spatial patterning on the function and global transcriptome of ECs are incompletely characterized. We used both parallel-aligned micropatterned and nanopatterned biomaterials to evaluate the effects of spatial patterning on the phenotype of ECs, based on gene expression profiling, functional characterization of monocyte adhesion, and quantification of cellular morphology. We demonstrate that both micropatterned and aligned nanofibrillar biomaterials could effectively guide EC organization along the direction of the micropatterned channels or nanofibrils, respectively. The ability of ECs to sense spatial patterning cues were abrogated in the presence of cytoskeletal disruption agents. Moreover, both micropatterned and aligned nanofibrillar substrates promoted an athero-resistant EC phenotype by reducing endothelial adhesiveness for monocytes and platelets, as well as by downregulating the expression of adhesion proteins and chemokines. We further found that micropatterned ECs have a transcriptional signature that is unique from non-patterned ECs, as well as from ECs aligned by shear stress. These findings highlight the importance of spatial patterning cues in guiding EC organization and function, which may have clinical relevance in the development of vascular grafts that promote patency., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
14. Aligned nanofibrillar collagen regulates endothelial organization and migration.
- Author
-
Lai ES, Huang NF, Cooke JP, and Fuller GG
- Subjects
- Animals, Anisotropy, Blood Vessel Prosthesis, Cell Shape drug effects, Endothelial Cells drug effects, Endothelial Cells metabolism, Endothelium transplantation, Humans, Rats, Cell Movement drug effects, Endothelial Cells cytology, Endothelium drug effects, Fibrillar Collagens pharmacology, Nanofibers chemistry
- Abstract
Aim: Modulating endothelial cell (EC) morphology and motility, with the aim to influence their biology, might be beneficial for the treatment of vascular disease. We examined the effect of nanoscale matrix anisotropy on EC organization and migration for vascular tissue engineering applications., Materials & Methods: We developed a flow processing technique to generate anisotropic nanofibrillar collagen. Human ECs were cultured on aligned or on randomly oriented collagen, and their cellular alignment and cytoskeletal organization were characterized by immunofluorescence staining and time-lapse microscopy., Results: ECs were elongated along the direction of aligned collagen nanofibrils and had organized focal adhesions. Cellular protrusion migrated with greater directionality and higher velocity along the anisotropic nanofibrils compared with cells on random nanofibrils. The flow technique can be adapted to fabricate vascular grafts that support the endothelial phenotype., Conclusion: Aligned nanofibrillar collagen regulates EC organization and migration, which can significantly contribute to the development of vascular grafts.
- Published
- 2012
- Full Text
- View/download PDF
15. Designing a tubular matrix of oriented collagen fibrils for tissue engineering.
- Author
-
Lai ES, Anderson CM, and Fuller GG
- Subjects
- Animals, Microscopy, Electron, Scanning, Rats, Collagen chemistry, Tissue Engineering
- Abstract
A scaffold composed entirely of an extracellular matrix component, such as collagen, with cellular level control would be highly desirable for applications in tissue engineering. In this article we introduce a novel, straightforward flow processing technique that fabricates a small diameter tubular matrix constructed of anisotropic collagen fibrils. Scanning electron microscopy confirmed the uniform alignment of the collagen fibrils and subsequent matrix-induced alignment of human fibroblasts. The uniform alignment of the fibroblasts along the collagen fibrils demonstrated the ability of the aligned fibrils to successfully dictate the directional growth of human fibroblasts through contact guidance. Various non-cytotoxic cross-linking techniques were also applied to the collagen conduit to enhance the mechanical properties. Tensile testing and burst pressure were the two measurements performed to characterize the mechanical integrity of the conduit. Mechanical characterization of the cross-linked collagen conduits identified 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide hydrochloride cross-linking as the most promising technique to reinforce the mechanical properties of native collagen. An oriented conduit of biocompatible material has been fabricated with decent mechanical strength and at a small diameter scale, which is especially applicable in engineering cardiovascular tissues and nerve grafts., (Copyright © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
16. Formation of stable submicron protein particles by thin film freezing.
- Author
-
Engstrom JD, Lai ES, Ludher BS, Chen B, Milner TE, Williams RO 3rd, Kitto GB, and Johnston KP
- Subjects
- Freezing, Particle Size, L-Lactate Dehydrogenase chemistry, Technology, Pharmaceutical
- Abstract
Purpose: Highly stable, submicron lactate dehydrogenase (LDH) and lysozyme particles may be produced by thin film freezing (TFF) of aqueous solutions followed by lyophilization., Methods: The LDH activity was determined by measuring the decrease in absorbance of NADH over time for the reaction of pyruvate to lactate. For lysozyme the particle morphology was determined by scanning electron microscopy (SEM) and compared with the specific surface area (BET) and the particle size, as measured by laser light scattering,, Results: Protein particles with an average diameter of 300 nm and 100% enzyme activity upon reconstitution (for LDH) were formed by TFF. Droplets of protein solutions, 3.6 mm in diameter, spread upon impact with 223 and 133 K metal surfaces to form cylindrical disks with thicknesses of 200-300 microm. Calculated cooling rates of the disks of 10(2) K/s were confirmed experimentally with infrared measurements., Conclusions: The cooling rates of 10(2) K/s, intermediate to those in lyophilization (1 K/min) and spray freeze-drying (SFD) (10(6) K/s), were sufficiently fast to produce sub-micron protein particles with surface areas of 31-73 m2/g, an order of magnitude higher than in lyophilization. In addition, the low surface area/volume ratio (32-45 cm(-1)) of the gas-liquid interface led to minimal protein adsorption and denaturation relative to SFD.
- Published
- 2008
- Full Text
- View/download PDF
17. Stable high surface area lactate dehydrogenase particles produced by spray freezing into liquid nitrogen.
- Author
-
Engstrom JD, Simpson DT, Cloonan C, Lai ES, Williams RO 3rd, Barrie Kitto G, and Johnston KP
- Subjects
- Animals, Catalysis, Drug Compounding, Drug Stability, Excipients, Freeze Drying, Freezing, Humidity, Microscopy, Electron, Scanning, Myocardium enzymology, Nanoparticles, Nitrogen, Powders, Surface Properties, Swine, L-Lactate Dehydrogenase chemistry
- Abstract
Enzyme activities were determined for lactate dehydrogenase (LDH) powder produced by lyophilization, and two fast freezing processes, spray freeze-drying (SFD) and spray freezing into liquid (SFL) nitrogen. The 0.25 mg/mL LDH aqueous feed solutions included either 30 or 100 mg/mL trehalose. The SFL process produced powders with very high enzyme activities upon reconstitution, similar to lyophilization. However, the specific surface area of 13 m(2)/g for SFL was an order of magnitude larger than for lyophilization. In SFD activities were reduced in the spraying step by the long exposure to the gas-liquid interface for 0.1-1s, versus only 2 ms in SFL. The ability to produce stable high surface area submicron particles of fragile proteins such as LDH by SFL is of practical interest in protein storage and in various applications in controlled release including encapsulation into bioerodible polymers. The SFL process has been scaled down for solution volumes <1 mL to facilitate studies of therapeutic proteins.
- Published
- 2007
- Full Text
- View/download PDF
18. Morphology of protein particles produced by spray freezing of concentrated solutions.
- Author
-
Engstrom JD, Simpson DT, Lai ES, Williams RO 3rd, and Johnston KP
- Subjects
- Algorithms, Freezing, Humidity, Microscopy, Electron, Scanning, Muramidase chemistry, Nitrogen, Particle Size, Pentanes, Powders, Solutions, Trehalose, Viscosity, Proteins chemistry
- Abstract
The mechanisms for the formation of high surface area lysozyme particles in spray freezing processes are described as a function of spray geometry and atomization, solute concentration and the calculated cooling rate. In the spray freeze-drying (SFD) process, droplets are atomized into a gas and then freeze upon contact with a liquid cryogen. In the spray freezing into liquid (SFL) process, a solution is sprayed directly into the liquid cryogen below the gas-liquid meniscus. A wide range of feed concentrations is examined for two cryogens, liquid nitrogen (LN2) and isopentane (i-C5). The particle morphologies are characterized by SEM micrographs and BET measurements of specific surface area. As a result of boiling of the cryogen (Leidenfrost effect), the cooling rate for SFL into LN2 is several orders of magnitude slower than for SFL into i-C5 and for SFD in the case of either LN2 or i-C5. For 50 mg/mL concentrated feed solutions, the slower cooling of SFL into LN2 leads to a surface area of 34 m(2)/g. For the other three cases with more rapid cooling rates, surface areas were greater than 100 m(2)/g. The ability to adjust the cooling rate to vary the final particle surface area is beneficial for designing particles for controlled release applications.
- Published
- 2007
- Full Text
- View/download PDF
19. A review of research related to blood transfusion in Canada, 2000-2002.
- Author
-
Teitel JM, Robillard P, Rock GA, Wong-Rieger D, Lai ES, and Chan P
- Subjects
- Canada, Capital Financing, Humans, Research Support as Topic, Blood Transfusion economics, Research economics
- Abstract
The former National Blood Safety Council undertook a comprehensive review of blood transfusion research in Canada for the years 2000 through 2002. Data were acquired by direct contact with agencies which support such research and by searches of the relevant websites. Total grant support increased markedly over the 3-year period, from 4.1 million dollars to 18.5 million dollars. Publicly funded granting agencies, biopharmaceutical companies, the blood services and the province of Ontario were major supporters. Much smaller amounts were granted from charitable organizations. Clinical research attracted the majority of the funding, although a larger number of projects were basic science in nature. Most research was carried out in the provinces of Ontario, Québec and British Columbia. Although we have not assessed the productivity of blood-related research, it appears that substantial amounts of funding were allocated to these projects between 2000 and 2002. These data may provide a helpful perspective to investigators in transfusion medicine elsewhere, who may also be assessing the relative priority given to this field of research in their own countries.
- Published
- 2004
- Full Text
- View/download PDF
20. In vivo, ex vivo, and in vitro one- and two-dimensional nuclear magnetic resonance spectroscopy of an intracerebral glioma in rat brain: assignment of resonances.
- Author
-
Rémy C, Arús C, Ziegler A, Lai ES, Moreno A, Le Fur Y, and Décorps M
- Subjects
- Amino Acids metabolism, Animals, Brain metabolism, Brain Neoplasms metabolism, Choline metabolism, Fatty Acids, Nonesterified metabolism, Glioma metabolism, Lactates metabolism, Lipid Metabolism, Magnetic Resonance Spectroscopy methods, Phospholipids metabolism, Rats, Taurine metabolism, Brain pathology, Brain Neoplasms pathology, Glioma pathology
- Abstract
An in vivo study of intracerebral rat glioma using proton-localized NMR spectroscopy showed important modifications of the spectra in the tumor as compared with the contralateral brain. To carry out the assignment of the resonances of the glioma spectra, tumoral and normal rat brain tissues were studied in vivo, ex vivo, and in vitro by one-dimensional and two-dimensional proton spectroscopy. N-Acetylaspartate was found at an extremely low level in the glioma. The change of peak ratio total creatine/3.2 ppm peak was found to be due to a simultaneous decrease of the total creatine content and an increase of the 3.2 ppm peak. The 3.2 ppm resonance in the glioma spectra has been shown to originate from choline, phosphocholine, glycerophosphocholine, taurine, inositol, and phosphoethanolamine. The increase of the 3.2 ppm peak in the glioma was found to result from the increase of taurine and phosphoethanolamine contents. The peak in the 1.3 ppm region of the glioma spectra was due to both lactate and mobile fatty acids. Moreover, two-dimensional spectroscopy of excised tissues and extracts showed the presence of hypotaurine only in the tumor.
- Published
- 1994
- Full Text
- View/download PDF
21. A survey on growth and sexual development of adolescent students in Changhua City: growth of body height and weight.
- Author
-
Lai ES and Yaung CL
- Subjects
- Body Height, Body Weight, Breast growth & development, China, Female, Humans, Longitudinal Studies, Male, Sex Factors, Skinfold Thickness, Adolescent, Sexual Maturation
- Abstract
In order to understand the physical growth and sexual development of contemporary adolescents, a cross-sectional survey was conducted during the period September 1983 to May 1984. The population came from all the pupils from 4th grade up, and all the junior and senior high students of Changhua City. By using stratified cluster sampling, 1419 boys and 1599 girls participated, ranging in age from 8 to 19 years. Body weight and height were measured. Growth spurt is a unique event during adolescence. It is well shown in the distance curves and pseudo-velocity curves of body height and weight. In boys, the growth spurt of height spanned from 12.0 to 14.8 years, with peak height velocity (PHV) at 13.5 years. In girls it was from 10.0 to 12.6 years and peaked at 11.5 years. The growth spurt of weight occurred from 12.0 to 15.9 years in boys with peak weight velocity (PWV) at 14.5 years, while girls had a growth spurt at 10.0-12.7 years with PWV at 11.5 years. Girls entered into the growth spurt about 2 years earlier, and also entered into PHV, PWV, two and three years earlier respectively than boys, while boys had a more intense and longer growth during the growth spurt than girls. Between 10.0-13.0 years girls were taller than boys, and between 12.0-13.0 years they were heavier than boys. However, from 13.5 years onward girls were soon surpassed by boys both in height and weight. Growth in height after 16.5 years in boys and after 15.5 in girls was minimal. Growth in weight in boys also became minimal after 16.5 years while girls weight even dropped a little bit after 16.5 years. At the mean age of 17.5 years, boys were 168.1 cm, girls were 156.2 cm in average, boys being 12 cm taller than girls after reaching their final height.
- Published
- 1987
22. Growth curves of adolescent students in Changhua City, Taiwan.
- Author
-
Lai ES and Yaung CL
- Subjects
- Cross-Sectional Studies, Female, Humans, Male, Pilot Projects, Reference Values, Taiwan, Adolescent, Growth
- Published
- 1988
23. Body height attained at the time of peak height velocity and at menarche: its relation to adult height.
- Author
-
Yaung CL and Lai ES
- Subjects
- Adolescent, Child, Cross-Sectional Studies, Female, Humans, Male, Taiwan, Body Height, Growth, Menarche physiology
- Published
- 1988
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.