Nanotopography reveals metabolites that maintain the immunomodulatory phenotype of mesenchymal stromal cells.

Mesenchymal stromal cells (MSCs) are multipotent progenitor cells that are of considerable clinical potential in transplantation and anti-inflammatory therapies due to their capacity for tissue repair and immunomodulation. However, MSCs rapidly differentiate once in culture, making their large-scale expansion for use in immunomodulatory therapies challenging. Although the differentiation mechanisms of MSCs have been extensively investigated using materials, little is known about how materials can influence paracrine activities of MSCs. Here, we show that nanotopography can control the immunomodulatory capacity of MSCs through decreased intracellular tension and increasing oxidative glycolysis. We use nanotopography to identify bioactive metabolites that modulate intracellular tension, growth and immunomodulatory phenotype of MSCs in standard culture and during larger scale cell manufacture. Our findings demonstrate an effective route to support large-scale expansion of functional MSCs for therapeutic purposes.

Application of the multi-theory model to explain veterinarians' intentions to use telehealth/telemedicine.

BACKGROUND: Telehealth adoption is being fueled by both technological breakthroughs and societal demands; however, veterinarians have yet to fully embrace the concept of telemedicine, limiting its use and potential benefits. The goal of this study was to evaluate how effective the multi-theory model (MTM) of health behaviour change explains the initiation and sustenance of telehealth use among veterinarians. METHODS: For this cross-sectional study, a research company was contracted to disseminate the MTM-based online survey to veterinarians currently engaged in clinical practice within the United States. RESULTS: A total of 243 veterinarians participated in this study. The most frequently reported age group among participants was 31-40 years (33.7%, n = 82). It was also noted that the majority of participants were female (70.0%, n = 170) and white (76.5%, n = 186). Hierarchical multiple regression showed that participatory dialogue (p = 0.037), species (p = 0.013) and previous monthly telehealth use (p = 0.040) were significant explanatory variables of initiation of telehealth use. Moreover, emotional transformation (p < 0.001) and previous monthly telehealth use (p = 0.035) were significant explanatory variables of sustenance of telehealth use. LIMITATIONS: The data were collected in July 2020, during a global pandemic, in which telehealth use surged across a variety of professions. As a result, the findings of the study may not be relevant in periods when there is no pandemic. CONCLUSIONS: Based on the findings of this study, researchers, educators and veterinary professionals should consider using MTM as theoretical framework to develop interventions to enhance telehealth use.

Cell-controlled dynamic surfaces for skeletal stem cell growth and differentiation.

Skeletal stem cells (SSCs, or mesenchymal stromal cells typically referred to as mesenchymal stem cells from the bone marrow) are a dynamic progenitor population that can enter quiescence, self-renew or differentiate depending on regenerative demand and cues from their niche environment. However, ex vivo, in culture, they are grown typically on hard polystyrene surfaces, and this leads to rapid loss of the SSC phenotype. While materials are being developed that can control SSC growth and differentiation, very few examples of dynamic interfaces that reflect the plastic nature of the stem cells have, to date, been developed. Achieving such interfaces is challenging because of competing needs: growing SSCs require lower cell adhesion and intracellular tension while differentiation to, for example, bone-forming osteoblasts requires increased adhesion and intracellular tension. We previously reported a dynamic interface where the cell adhesion tripeptide arginine-glycine-aspartic acid (RGD) was presented to the cells upon activation by user-added elastase that cleaved a bulky blocking group hiding RGD from the cells. This allowed for a growth phase while the blocking group was in place and the cells could only form smaller adhesions, followed by an osteoblast differentiation phase that was induced after elastase was added which triggered exposure of RGD and subsequent cell adhesion and contraction. Here, we aimed to develop an autonomous system where the surface is activated according to the need of the cell by using matrix metalloprotease (MMP) cleavable peptide sequences to remove the blocking group with the hypothesis that the SSCs would produce higher levels of MMP as the cells reached confluence. The current studies demonstrate that SSCs produce active MMP-2 that can cleave functional groups on a surface. We also demonstrate that SSCs can grow on the uncleaved surface and, with time, produce osteogenic marker proteins on the MMP-responsive surface. These studies demonstrate the concept for cell-controlled surfaces that can modulate adhesion and phenotype with significant implications for stem cell phenotype modulation.

Materials-driven fibronectin assembly on nanoscale topography enhances mesenchymal stem cell adhesion, protecting cells from bacterial virulence factors and preventing biofilm formation.

Post-operative infection is a major complication in patients recovering from orthopaedic surgery. As such, there is a clinical need to develop biomaterials for use in regenerative surgery that can promote mesenchymal stem cell (MSC) osteospecific differentiation and that can prevent infection caused by biofilm-forming pathogens. Nanotopographical approaches to pathogen control are being identified, including in orthopaedic materials such as titanium and its alloys. These topographies use high aspect ratio nanospikes or nanowires to prevent bacterial adhesion but these features also significantly reduce MSC adhesion and activity. Here, we use a poly (ethyl acrylate) (PEA) polymer coating on titanium nanowires to spontaneously organise fibronectin (FN) and to deliver bone morphogenetic protein 2 (BMP2) to enhance MSC adhesion and osteospecific signalling. Using a novel MSC-Pseudomonas aeruginosa co-culture, we show that the coated nanotopographies protect MSCs from cytotoxic quorum sensing and signalling molecules, enhance MSC adhesion and osteoblast differentiation and reduce biofilm formation. We conclude that the PEA polymer-coated nanotopography can both support MSCs and prevent pathogens from adhering to a biomaterial surface, thus protecting from biofilm formation and bacterial infection, and supporting osteogenic repair.

Associations among Stress, Anxiety, Depression, and Emotional Intelligence among Veterinary Medicine Students.

Background: Veterinary students are faced with immense pressures and rigors during school. These pressures have contributed to elevated levels of stress, anxiety, and depression (SAD) among veterinary students relative to the general population. One proposed concept to help students combat SAD is that of emotional intelligence (EI). We explored the relationship between EI and SAD among veterinary students at a college in the Southeast United States. Methods: A cross-sectional study design was implemented among a convenience sample of 182 veterinary medical students. The survey instrument contained 56 items that elicited information about students' demographics, perceived stress, anxiety, and depression, and emotional intelligence levels. Data analysis included univariate statistics, Pearson's correlations, and multiple regression and independent samples t-tests. Results: The study revealed a statistically significant, negative correlation between EI levels and stress, anxiety, and depression. Additionally, a statistically significant, positive correlation was found between stress and anxiety as well as both stress and anxiety and depression. Multiple linear regression showed that EI was a statistically significant predictor of stress (b = -0.239, p < 0.001), anxiety (b = -0.044, p < 0.001), and depression (b = -0.063, p < 0.001), after controlling for sociodemographic variables. Students' t-test results revealed a statistically significant mean difference in EI scores among students screening positive versus negative for depression, with students screening negative having a mean EI score of 10.81 points higher than students who screened positive for depression. Conclusion: There is a scientifically supported need for interventions in veterinary school to integrate EI into the veterinary medical curriculum and consider the EI levels of veterinary student candidates.

The use of nanovibration to discover specific and potent bioactive metabolites that stimulate osteogenic differentiation in mesenchymal stem cells.

Bioactive metabolites have wide-ranging biological activities and are a potential source of future research and therapeutic tools. Here, we use nanovibrational stimulation to induce osteogenic differentiation of mesenchymal stem cells, in the absence of off-target, nonosteogenic differentiation. We show that this differentiation method, which does not rely on the addition of exogenous growth factors to culture media, provides an artifact-free approach to identifying bioactive metabolites that specifically and potently induce osteogenesis. We first identify a highly specific metabolite, cholesterol sulfate, an endogenous steroid. Next, a screen of other small molecules with a similar steroid scaffold identified fludrocortisone acetate with both specific and highly potent osteogenic-inducing activity. Further, we implicate cytoskeletal contractility as a measure of osteogenic potency and cell stiffness as a measure of specificity. These findings demonstrate that physical principles can be used to identify bioactive metabolites and then enable optimization of metabolite potency can be optimized by examining structure-function relationships.

Endothelial Cells: Co-culture Spheroids.

The development and maintenance of a functioning vascular system is a critical function for many aspects of tissue growth and regeneration. Vascular endothelial cell in vitro co-culture spheroids are self-organized cell composites that have the capacity to recapitulate the three-dimensional tissue microenvironment. These spheroid testing platforms aim to better understand the mechanisms of functional tissue and how new therapeutic agents can drive these 3D co-culture processes. Here we describe direct cell-cell 3D endothelial co-culture spheroid methods, to examine the physiological spatial growth and cell-cell interaction of vascular cells and surrounding native tissue cells in the formation of vascular networks within spheroids and the potential to regenerate tissue.

Chondrobags: A high throughput alginate-fibronectin micromass platform for in vitro human cartilage formation.

The maintenance and expansion of the cells required for formation of tissue-engineered cartilage has, to date, proven difficult. This is, in part, due to the initial solid phase extracellular matrix demanded by the cells inhabiting this avascular tissue. Herein, we engineer an innovative alginate-fibronectin microfluidic-based carrier construct (termed a chondrobag) equipped with solid phase presentation of growth factors that support skeletal stem cell chondrogenic differentiation while preserving human articular chondrocyte phenotype. Results demonstrate biocompatibility, cell viability, proliferation and tissue-specific differentiation for chondrogenic markers SOX9, COL2A1 and ACAN. Modulation of chondrogenic cell hypertrophy, following culture within chondrobags loaded with TGF-ß1, was confirmed by down-regulation of hypertrophic genes COL10A1 and MMP13. MicroRNAs involved in the chondrogenesis process, including miR-140, miR-146b and miR-138 were observed. Results demonstrate the generation of a novel high-throughput, microfluidic-based, scalable carrier that supports human chondrogenesis with significant implications therein for cartilage repair-based therapies.

Nanovibrational Stimulation of Mesenchymal Stem Cells Induces Therapeutic Reactive Oxygen Species and Inflammation for Three-Dimensional Bone Tissue Engineering.

There is a pressing clinical need to develop cell-based bone therapies due to a lack of viable, autologous bone grafts and a growing demand for bone grafts in musculoskeletal surgery. Such therapies can be tissue engineered and cellular, such as osteoblasts, combined with a material scaffold. Because mesenchymal stem cells (MSCs) are both available and fast growing compared to mature osteoblasts, therapies that utilize these progenitor cells are particularly promising. We have developed a nanovibrational bioreactor that can convert MSCs into bone-forming osteoblasts in two- and three-dimensional, but the mechanisms involved in this osteoinduction process remain unclear. Here, to elucidate this mechanism, we use increasing vibrational amplitude, from 30 nm (N30) to 90 nm (N90) amplitudes at 1000 Hz and assess MSC metabolite, gene, and protein changes. These approaches reveal that dose-dependent changes occur in MSCs' responses to increased vibrational amplitude, particularly in adhesion and mechanosensitive ion channel expression and that energetic metabolic pathways are activated, leading to low-level reactive oxygen species (ROS) production and to low-level inflammation as well as to ROS- and inflammation-balancing pathways. These events are analogous to those that occur in the natural bone-healing processes. We have also developed a tissue engineered MSC-laden scaffold designed using cells' mechanical memory, driven by the stronger N90 stimulation. These mechanistic insights and cell-scaffold design are underpinned by a process that is free of inductive chemicals.

Factors Associated with Initiation and Sustenance of Stress Management Behaviors in Veterinary Students: Testing of Multi-Theory Model (MTM).

Veterinary students across the United States face the challenge of stress during school every day. When managed improperly, stress can become chronic and manifest in physical and emotional consequences. The purpose of this study was to examine the utility of the multi-theory model (MTM) of health behavior change in predicting the initiation and sustenance of stress management behaviors among veterinary students. A cross-sectional design was used to study the efficacy of the MTM in predicting initiation and sustenance of stress management behaviors among veterinary students at a private College of Veterinary Medicine in the Southeast United States. Researchers collected data using a 54-item valid and reliable survey. Only students who did not already engage in daily stress management behaviors were included in the study. After recruitment and exclusion, a total of 140 students remained and participated in the study. Hierarchical multiple regression revealed that, for initiation of stress management behaviors, 49.5% of the variance was explained by depression, academic classification, and behavioral confidence. Regarding sustenance of stress management behaviors, 50.4% of the variance was explained by perceived stress, depression, academic classification, and emotional transformation. MTM serves as a promising framework for predicting initiation and sustenance of health behavior change. Based on the results of this study, interventions aimed to promote stress management behaviors in veterinary students should focus on the MTM constructs of behavioral confidence and emotional transformation.

The experiences of older adults with a diagnosed functional mental illness, their carers and healthcare professionals in relation to mental health service delivery: An integrative review.

AIMS AND OBJECTIVES: To analyse the experiences of older people with a diagnosed functional mental illness and their carers in relation to mental health service delivery and analyse the experiences of health and social care professionals who care for and treat older people who have a diagnosed functional mental illness. BACKGROUND: The prevalence of functional mental illness in older adults is notable but to date has received less research attention than dementia. Older adults with functional mental illness have life expectancy of up to 20 years less than the rest of the population. Therefore, the experiences of older adults with functional mental illness, their carers and healthcare professionals, in relation to mental health services, need further exploration. DESIGN: Integrative literature review. METHODS: A five-stage process was informed by Whittemore and Knafl. MeSH was used. Keyword searches of MEDLINE, CINAHL, Cochrane Library, PsycINFO, EMBASE and AMED were conducted between January 2000-October 2017. Titles were screened, and data were extracted manually and analysed using narrative synthesis. The PRISMA checklist was used. RESULTS: A total of 342 articles were deemed potentially relevant to this review. Once inclusion and exclusion criteria were applied, 28 articles were included. The literature presented an overarching theme "determinants influencing older people with functional mental illness use of services." The overarching theme is supported by two main themes: inevitable consequences of ageing and variations of the availability of healthcare services for older people with functional mental illness. CONCLUSION: Several determinants influence use of services by older people with functional mental illness. Older people with functional mental illness often perceived they did not have a mental health need. Within the literature, there was little acknowledgement of the experiences of older people with functional mental illness regarding their support needs. RELEVANCE TO CLINICAL PRACTICE: This integrative review has highlighted that some older people with functional mental illness do not seek mental health support because they believe that functional mental illness is an inevitable consequence of ageing; this is mirrored at times by healthcare professionals and carers. In addition to this finding, different views prevail regarding the impact that ageless and age-defined mental health service delivery models have on the needs of older people with functional mental illness. Further research is required to understand these findings.

A survey of knowledge and use of telehealth among veterinarians.

BACKGROUND: As usage of digital information and communication technologies continues to grow, the incorporation of telehealth and telemedicine has become a topic of interest in the veterinary industry. Veterinary telemedicine presents the opportunity to expand veterinary medicine by increasing access to healthcare services for clients and patients and improving medical quality. The objective of this study was to assess veterinarians' knowledge and utilization of telehealth and telemedicine. RESULTS: Seventy-six veterinarians participated in the study and both qualitative and quantitative analyses were performed on the data collected. Several key themes emerged from the qualitative analysis of open-ended questions, including telecommunication, Doctor of Veterinary Medicine (DVM)-patient services, and remote interaction, among others. Through coding and qualitative analysis, researchers identified a lack of knowledge of the American Veterinary Medical Association (AVMA) definitions of telehealth and telemedicine. Specifically, a notable amount of participants were unaware of the distinction between the two practices per AVMA guidelines. Quantitative analyses revealed that the largest group of respondents reported sometimes utilizing telehealth and telemedicine in practice, with no distinct difference in utilization among the different age demographics of participants. CONCLUSIONS: These observations indicate a need for interventions both in veterinary school and continuing education programs with the purpose of increasing both knowledge and utilization of telehealth and telemedicine among veterinarians. While these recommendations serve as a starting point, future studies are needed to further enhance the understanding of veterinary telehealth and telemedicine in practice.

"I Was Doctor": White Settler Women's Amateur Medical Practice in East and South-Central African Communities, 1890-1939.

Professional medicine in colonial British Africa has been extensively examined by historians. Few scholars, however, have adequately considered the role that white settlers without medical training played in the provision of colonial health care in local African communities. This article addresses the gap by exploring amateur medical treatment by white settler women in East and South-Central African communities between 1890 and 1939, primarily in highland areas of Kenya and Southern Rhodesia. It examines the types of conditions treated, what techniques and equipment were used for treatment, and where treatment was carried out. It also explores medical identity in settler women's memoirs. Last, it considers the degree of choice exercised by patients in these amateur medical encounters. Overall, this article situates white settlers' amateur treatment in African communities as an important strand of colonial health care and as an intimate contact zone between white settlers, colonial medicine, and local people.

Case Report: Imported Case of Lassa Fever - New Jersey, May 2015.

We report a fatal case of Lassa fever diagnosed in the United States in a Liberian traveler. We describe infection control protocols and public health response. One contact at high risk became symptomatic, but her samples tested negative for Lassa virus; no secondary cases occurred among health care, family, and community contacts.

New therapeutic opportunities from dissecting the pre-B leukemia bone marrow microenvironment.

The microenvironments of leukemia and cancer are critical for multiple stages of malignancies, and they are an attractive therapeutic target. While skeletal abnormalities are commonly seen in children with acute lymphoblastic leukemia (ALL) prior to initiating osteotoxic therapy, little is known about the alterations to the bone marrow microenvironment during leukemogenesis. Therefore, in this study, we focused on the development of precursor-B cell ALL (pre-B ALL) in an immunocompetent BCR-ABL1+ model. Here we show that hematopoiesis was perturbed, B lymphopoiesis was impaired, collagen production was reduced, and the number of osteoblastic cells was decreased in the bone marrow microenvironment. As previously found in children with ALL, the leukemia-bearing mice exhibited severe bone loss during leukemogenesis. Leukemia cells produced high levels of receptor activator of nuclear factor κB ligand (RANKL), sufficient to cause osteoclast-mediated bone resorption. In vivo administration of zoledronic acid rescued leukemia-induced bone loss, reduced disease burden and prolonged survival in leukemia-bearing mice. Taken together, we provide evidence that targeting leukemia-induced bone loss is a therapeutic strategy for pre-B ALL.

Philadelphia chromosome-like acute lymphoblastic leukemia: progress in a new cancer subtype.

Philadelphia chromosome-like (Ph-like) acute lymphoblastic leukemia (ALL) is a newly described, high-risk subtype of B-cell ALL. It is characterized by a gene expression profile similar to that of Ph-positive ALL; however, the BCR-ABL1 fusion is not present. The World Health Organization classification of myeloid neoplasms and acute leukemia recently was updated to include the Ph-like or BCR-ABL1-like ALL subtype of B-cell ALL as a provisional entity. Unlike Ph-positive ALL, which is characterized by the pathognomonic BCR-ABL1 fusion, Ph-like ALL is characterized by a multitude of different genetic rearrangements and mutations. In this review, we outline the age-related and geographic incidence of Ph-like ALL, the association with worse clinical outcomes, and early evidence for the use of ruxolitinib (a Janus kinase 2 inhibitor) and dasatinib (a tyrosine kinase inhibitor targeting ABL1).

Enrichment increases hippocampal neurogenesis independent of blood monocyte-derived microglia presence following high-dose total body irradiation.

Birth of new neurons in the hippocampus persists in the brain of adult mammals and critically underpins optimal learning and memory. The process of adult neurogenesis is significantly reduced following brain irradiation and this correlates with impaired cognitive function. In this study, we aimed to compare the long-term effects of two environmental paradigms (i.e. enriched environment and exercise) on adult neurogenesis following high-dose (10Gy) total body irradiation. When housed in standard (sedentary) conditions, irradiated mice revealed a long-lasting (up to 4 months) deficit in neurogenesis in the granule cell layer of the dentate gyrus, the region that harbors the neurogenic niche. This depressive effect of total body irradiation on adult neurogenesis was partially alleviated by exposure to enriched environment but not voluntary exercise, where mice were single-housed with unlimited access to a running wheel. Exposure to voluntary exercise, but not enriched environment, did lead to significant increases in microglia density in the granule cell layer of the hippocampus; our study shows that these changes result from local microglia proliferation rather than recruitment and infiltration of circulating Cx3cr1+/gfp blood monocytes that subsequently differentiate into microglia-like cells. In summary, latent neural precursor cells remain present in the neurogenic niche of the adult hippocampus up to 8 weeks following high-dose total body irradiation. Environmental enrichment can partially restore the adult neurogenic process in this part of the brain following high-dose irradiation, and this was found to be independent of blood monocyte-derived microglia presence.

Nanotopography controls cell cycle changes involved with skeletal stem cell self-renewal and multipotency.

In culture isolated bone marrow mesenchymal stem cells (more precisely termed skeletal stem cells, SSCs) spontaneously differentiate into fibroblasts, preventing the growth of large numbers of multipotent SSCs for use in regenerative medicine. However, the mechanisms that regulate the expansion of SSCs, while maintaining multipotency and preventing fibroblastic differentiation are poorly understood. Major hurdles to understanding how the maintenance of SSCs is regulated are (a) SSCs isolated from bone marrow are heterogeneous populations with different proliferative characteristics and (b) a lack of tools to investigate SSC number expansion and multipotency. Here, a nanotopographical surface is used as a tool that permits SSC proliferation while maintaining multipotency. It is demonstrated that retention of SSC phenotype in culture requires adjustments to the cell cycle that are linked to changes in the activation of the mitogen activated protein kinases. This demonstrates that biomaterials can offer cross-SSC culture tools and that the biological processes that determine whether SSCs retain multipotency or differentiate into fibroblasts are subtle, in terms of biochemical control, but are profound in terms of determining cell fate.

Heterogeneity in mechanisms of emergent resistance in pediatric T-cell acute lymphoblastic leukemia.

Relapse in pediatric T-cell acute lymphoblastic leukemia (T-ALL) remains a significant clinical problem and is thought to be associated with clonal selection during treatment. In this study we used an established pre-clinical model of induction therapy to increase our understanding of the effect of engraftment and chemotherapy on clonal selection and acquisition of drug resistance in vivo. Immune-deficient mice were engrafted with patient diagnostic specimens and exposed to a repeated combination therapy consisting of vincristine, dexamethasone, L-asparaginase and daunorubicin. Any re-emergence of disease following therapy was shown to be associated with resistance to dexamethasone, no resistance was observed to the other three drugs. Immunoglobulin/T-cell receptor gene rearrangements closely matched those in respective diagnosis and relapse patient specimens, highlighting that these clonal markers do not fully reflect the biological changes associated with drug resistance. Gene expression profiling revealed the significant underlying heterogeneity of dexamethasone-resistant xenografts. Alterations were observed in a large number of biological pathways, yet no dominant signature was common to all lines. These findings indicate that the biological changes associated with T-ALL relapse and resistance are stochastic and highly individual, and underline the importance of using sophisticated molecular techniques or single cell analyses in developing personalized approaches to therapy.