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BackgroundAlzheimer's disease and related dementias (AD/ADRD) are a public health challenge for Vietnam because of its rapidly aging population. However, very few community-based programs exist to support people living with AD/ADRD and their family caregivers. Resources for Enhancing Alzheimer's Caregiver Health in Vietnam (REACH VN) is a culturally adapted family caregiver intervention shown in a pilot study to be feasible and promising in terms of preliminary efficacy. We describe the protocol for a larger cluster randomized controlled trial (RCT) to test the efficacy of REACH VN among family caregivers of people living with dementia in a semi-rural area outside of Hanoi, Vietnam.MethodsThirty-two clusters with approximately 350 caregivers will be randomized to either REACH VN intervention or enhanced usual care. REACH VN is a multicomponent intervention delivered in-home or by phone over the course of 2 to 3 months. To be eligible, family caregivers need to be ≥18 years old, be the person who provides the most day-to-day care for people living with dementia, and have a score ≥ 6 on the Zarit Burden Interview-4. The primary outcomes are caregiver burden (Zarit Burden Interview-12) and psychological distress (Patient Health Questionnaire-4). Secondary outcomes include caregiver somatic symptoms (Patient Health Questionnaire-15) and perceived stress (Perceived Stress Scale-10). These outcomes will be assessed at baseline, 3 months, and 6 months. Exploratory analyses to examine potential mediators of primary outcomes are also planned.DiscussionTo our knowledge, this is the first large-scale study to test the efficacy of a community-based family dementia caregiver intervention in Vietnam. Results from this study will help inform efforts to widely deliver the REACH VN intervention or similar community-based family dementia caregiver support programs in Vietnam and other low- and middle-income countries (LMIC).Trial registrationClinicalTrials.gov NCT04542317 . Registered on 9 September 2020.

AimsWe prospectively isolate and characterize first and second heart field- and nodal-like cardiomyocytes using a double reporter line from human embryonic stem cells. Our double reporter line utilizes two important transcription factors in cardiac development, TBX5 and NKX2-5. TBX5 expression marks first heart field progenitors and cardiomyocytes while NKX2-5 is expressed in nearly all myocytes of the developing heart (excluding nodal cells). We address the shortcomings of prior work in the generation of heart field-specific cardiomyocytes from induced pluripotent stem cells and provide a comprehensive early developmental transcriptomic as well as electrophysiological analyses of these three populations.Methods and resultsTranscriptional, immunocytochemical, and functional studies support the cellular identities of isolated populations based on the expression pattern of NKX2-5 and TBX5. Importantly, bulk and single-cell RNA sequencing analyses provide evidence of unique molecular signatures of isolated first and second heart field cardiomyocytes, as well as nodal-like cells. Extensive electrophysiological analyses reveal dominant atrial action potential phenotypes in first and second heart fields in alignment with our findings in single-cell RNA sequencing. Lastly, we identify two novel surface markers, POPDC2 and CORIN, that enable purification of cardiomyocytes and first heart field cardiomyocytes, respectively.ConclusionsWe describe a high-yield approach for isolation and characterization of human embryonic stem cell-derived heart field-specific and nodal-like cardiomyocytes. Obtaining enriched populations of these different cardiomyocyte subtypes increases the resolution of gene expression profiling during early cardiogenesis, arrhythmia modelling, and drug screening. This paves the way for the development of effective stem cell therapy to treat diseases that affect specific regions of the heart- or chamber-specific congenital heart defects.

Background: Human embryonic stem cell-derived cardiomyocytes (hESC-CMs) can be used as a source for cell delivery to remuscularize the heart after myocardial infarction. Despite their therapeutic potential, the emergence of ventricular arrhythmias has limited their application. We previously developed a double reporter hESC line to isolate first heart field (FHF: TBX5 + NKX2-5 +) and second heart field (SHF: TBX5 - NKX2-5 + ) CMs. Herein, we explore the role of TBX5 and its effects on underlying gene regulatory networks driving phenotypical and functional differences between these two populations. Methods: We used a combination of tools and techniques for rapid and unsupervised profiling of FHF and SHF populations at the transcriptional, translational, and functional level including single cell RNA (scRNA) and bulk RNA sequencing, atomic force and quantitative phase microscopy, respirometry, and electrophysiology. Results: Gene ontology analysis revealed three biological processes attributed to TBX5 expression: sarcomeric structure, oxidative phosphorylation, and calcium ion handling. Interestingly, migratory pathways were enriched in SHF population. SHF-like CMs display less sarcomeric organization compared to FHF-like CMs, despite prolonged in vitro culture. Atomic force and quantitative phase microscopy showed increased cellular stiffness and decreased mass distribution over time in FHF compared to SHF populations, respectively. Electrophysiological studies showed longer plateau in action potentials recorded from FHF-like CMs, consistent with their increased expression of calcium handling genes. Interestingly, both populations showed nearly identical respiratory profiles with the only significant functional difference being higher ATP generation-linked oxygen consumption rate in FHF-like CMs. Our findings suggest that FHF-like CMs display more mature features given their enhanced sarcomeric alignment, calcium handling, and decreased migratory characteristics. Finally, pseudotime analyses revealed a closer association of the FHF population to human fetal CMs along the developmental trajectory. Conclusion: Our studies reveal that distinguishing FHF and SHF populations based on TBX5 expression leads to a significant impact on their downstream functional properties. FHF CMs display more mature characteristics such as enhanced sarcomeric organization and improved calcium handling, with closer positioning along the differentiation trajectory to human fetal hearts. These data suggest that the FHF CMs may be a more suitable candidate for cardiac regeneration.

Ligand-dependent Cre recombinases are pivotal tools for the generation of inducible somatic mutants. This method enables spatial and temporal control of gene activity through tamoxifen administration, providing new avenues for studying gene function and establishing animal models of human diseases. While this paved the way for developmental studies previously deemed impractical, the generation of tissue-specific transgenic mouse lines can be time-consuming and costly. Herein, we design a 'smart', biocompatible, and biodegradable nanoparticle system encapsulated with tamoxifen that is actively targeted to specific cell types in vivo through surface conjugation of antibodies. We demonstrate that these nanoparticles bind to cells of interest and activate Cre recombinase, resulting in tissue-specific Cre activation. This system provides a versatile, yet powerful approach to induce recombination in a ubiquitious Cre system for various biomedical applications and sets the stage for a time- and cost-effective strategy of generating new transgenic mouse lines.

The cellular mechanisms driving cardiac tissue formation remain poorly understood, largely due to the structural and functional complexity of the heart. It is unclear whether newly generated myocytes originate from cardiac stem/progenitor cells or from pre-existing cardiomyocytes that re-enter the cell cycle. Here, we identify the source of new cardiomyocytes during mouse development and after injury. Our findings suggest that cardiac progenitors maintain proliferative potential and are the main source of cardiomyocytes during development; however, the onset of αMHC expression leads to reduced cycling capacity. Single-cell RNA sequencing reveals a proliferative, "progenitor-like" population abundant in early embryonic stages that decreases to minimal levels postnatally. Furthermore, cardiac injury by ligation of the left anterior descending artery was found to activate cardiomyocyte proliferation in neonatal but not adult mice. Our data suggest that clonal dominance of differentiating progenitors mediates cardiac development, while a distinct subpopulation of cardiomyocytes may have the potential for limited proliferation during late embryonic development and shortly after birth.

Nkx2-5 is a homeobox-containing transcriptional regulator that serves as one of the earliest markers of cardiac lineage commitment. To study the role of Nkx2-5-expressing progenitors at specific time points in cardiac development, we have generated a novel and inducible NKX2-5 mouse line by knocking in a CreER cassette into the Nkx2-5 genomic locus, while preserving the endogenous Nkx2-5 gene to avoid haploinsufficiency. We evaluated the specificity and efficiency of CreER activity after 4-OHT injection by crossing Nkx2-5CreER/+ mice with a Rosa26tdT/+ reporter strain. Our immunohistochemistry results confirmed Cre-induced tdTomato expression specifically in cells expressing Nkx2-5. These cells were mainly cardiomyocytes and were observed in the embryonic heart as early as day 9.5. Additionally, quantitative polymerase chain reaction on postnatal hearts showed enriched expression of Nkx2-5 in isolated tdTomato-expressing cells. No tdTomato expression was observed in Nkx2-5CreER/+ ;Rosa26tdT/+ mice in the absence of 4-OHT, confirming the inducible nature of CreER activity. The Nkx2-5/CreER mouse model described in this article will serve as an invaluable tool to trace myocardial lineage and to temporally induce genetic manipulation in a selective population of cardiac progenitors during embryonic development and in the adult heart.

This study explores the role of virtual reality (VR) tours in influencing customers' experiences and attitudes as well as their behavioral intentions toward VR tours. A research model that combines the technology acceptance model, flow theory, and social distancing is proposed to demonstrate the interrelationships among attributes of VR tours, online customer experience, customer attitude, and behavioral intention. Social distancing plays a situational role in the model. We collected 545 usable online questionnaires and used SPSS and SmartPLS to analyze the measurement model and proposed hypotheses. Attributes of the VR tour had a positive influence on the extrinsic values and intrinsic values of the customer experience. Furthermore, online customer experience was positively related to customer attitude and intention toward VR tours. In addition, social distancing influenced customer attitudes but not behavioral intention. Moreover, the results of a multigroup analysis based on country of residence suggested relevant differences between the America and Asia groups. This research extends understanding of the online customer experience of VR tours and provides empirical evidence that VR attributes enhance the extrinsic and intrinsic values of online customer experiences. It provides an integrated view of the technology acceptance model, flow theory, and social distancing and suggests that social distancing has an impact on customers' attitude toward VR tours but no effects on their intention. The implications of these findings can help scholars and practitioners better understand consumers' motivations and behavioral intentions to use VR tours, which will help the tourism industry boost revenue and create additional sales channels. [ABSTRACT FROM AUTHOR]

Author(s): Steven E. Scherer (corresponding author) [1]; Donna M. Muzny [1]; Christian J. Buhay [1]; Rui Chen [1]; Andrew Cree [1]; Yan Ding [1]; Shannon Dugan-Rocha [1]; Rachel Gill [1]; [...]

Downloaded from http://journals.lww.com/dermatologicsurgery by BhDMf5ePHKbH4TTImqenVA+lpWIIBvonhQl60EtgtdlLYrLzSPu+hUapVK5dvms8 on 03/22/2021 Downloaded from http://journals.lww.com/dermatologicsurgery by BhDMf5ePHKbH4TTImqenVA+lpWIIBvonhQl60EtgtdlLYrLzSPu+hUapVK5dvms8 on 03/22/2021 Acknowledgments Patients provided written consent for the use of their images. ADA-AAOS prophylaxis guidelines for the prevention of hematogenous prosthetic joint infection have changed significantly, and routine AP may no longer be necessary for dermatologic procedures even in high-risk patients. Antibiotic prophylaxis recommendations for many fields, including dermatology, are extrapolated fromguidelinesissuedbyauthoritativesourcesincluding the American Heart Association (AHA), American Dental Association (ADA), and American Academy of Orthopaedic Surgeons (AAOS). [Extracted from the article]