Function of CD44(Pgp-1) homing receptor in human T cell precursors

T cell precursors migrate from extrathymic hematopoietic tissues and dlfferentlate after encountering the thymic microenvironment. We asked whether human T cell precursors express the CD44(Pgp-l/gp90HR) class of homing receptors that have been implicated in the traffic of hematopoietic cells, such as lymphocyte entry to peripheral lymphold organs. Flow cytometry and immunoprecipitation studies demonstrate that CD7+34+, CD1-2-3-4-8- 14-16-20- cells in bone marrow and thymus, which have been shown to exhibit features of T cell precursors, bear CD44. Immunohlstologoical studies show that clusters of thymocytes in the subcapsular and the inner cortex and most medullary thymocytes are clearly CD44+, whereas the expression of CD44 is selectively downregulated in CD3- and CD3low functionally incompetent cortical thymocytes. The expression of CD44 is not restricted to T cell precursors but also occurs in thymic stroma, which bear a different molecular species of CD44. CD44-specific antibodies exert stimulatory effects on T cell precursors, a process that is dependent on stromal cells. We postulate that CD44 might be an adhesion molecule for precursor homing to thymus and that it participates in cell-to-cell interactions within the thymic environmen

Thymic stroma is required for the development of human T cell lineages in vitro

Development of the T cell lineage is characterized by the homing of hematopoietic precursors to thymus, followed by their acquisition of receptors for antigen. T cell receptors are αβ or γδ heterodimers associated with CD3 (TCR-CD3). Very early T cell precursors in humans have been characterized as CD7+45+ cells which lack the T cell differentiation antigens CD1, CD2, CD3, CD4, and CD8. A phenotypically equivalent early thymocyte population also occurs in postnatal life, and we have previously shown that interleukin 2 (IL2) promotes the development in vitro of both the αβ and the γδ T cells from these early thymocytes. Here we have analyzed the requirements of the induction of the IL2 pathway in early thymocytes, and their developmental potential. We show that: (I) thymic stromal cells, which are present in thymocyte suspensions, are necessary to induce the IL2 pathway and the development of αβ or γδ T cell lineages from early thymocytes in vitro; and (II) when removed from the in vivo environment, early thymocytes can develop in vitro into TCR-CD3− cells of the natural killer (NK) lineage. We conclude that CD7+45+, CD1-2-3-4-8- early thymocytes are multipotential progenitors that, at least, have the capacity to develop into αβ or γδ T cell and NK lineages. The analysis of the mechanisms of generation and selection of human T and NK cell diversity, not feasible in bone marrow cultures, is now possibl

Prevalence of and associations with agitation in residents with dementia living in care homes: MARQUE cross-sectional study

BACKGROUND: Agitation is reportedly the most common neuropsychiatric symptom in care home residents with dementia. AIMS: To report, in a large care home survey, prevalence and determinants of agitation in residents with dementia. METHOD: We interviewed staff from 86 care homes between 13 January 2014 and 12 November 2015 about residents with dementia with respect to agitation (Cohen-Mansfield Agitation Inventory (CMAI)), quality of life (DEMQOL-proxy) and dementia severity (Clinical Dementia Rating). We also interviewed residents and their relatives. We used random effects models adjusted for resident age, gender, dementia severity and care home type with CMAI as a continuous score. RESULTS: Out of 3053 (86.2%) residents who had dementia, 1489 (52.7%) eligible residents participated. Fifteen per cent of residents with very mild dementia had clinically significant agitation compared with 33% with mild (odds ratios (ORs)=4.49 95% confidence interval (CI)=2.30) and 45% with moderate or severe dementia (OR=6.95 95% CI=3.63, 13.31 and OR=6.23 95% CI=3.25, 11.94, respectively). More agitation was associated with lower quality of life (regression coefficient (rc)=-0.53; 95% CI=-0.61, -0.46) but not with staffing or resident ratio (rc=0.03; 95% CI=-0.04, 0.11), level of residents' engagement in home activities (rc=3.21; 95% CI=-0.82, 7.21) or family visit numbers (rc=-0.03; 95% CI=-0.15, 0.08). It was correlated with antipsychotic use (rc=6.45; 95% CI=3.98, 8.91). CONCLUSIONS: Care home residents with dementia and agitation have lower quality of life. More staffing time and activities as currently provided are not associated with lower agitation levels. New approaches to develop staff skills in understanding and responding to the underlying reasons for individual resident's agitation require development and testing. DECLARATION OF INTEREST: None. COPYRIGHT AND USAGE: © The Royal College of Psychiatrists 2017. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) license

Cellular mechanisms regulating synthetic sex ratio distortion in the Anopheles gambiae germline

Genetic control strategies aimed to bias the sex of progenies towards males present a promising new paradigm to eliminate malaria-transmitting mosquitoes. A synthetic sex-ratio distortion (SD) system was successfully engineered in Anopheles gambiae by exploiting the meiotic activity of the I-PpoI endonuclease targeting ribosomal DNA (rDNA) repeats, exclusively located on the X chromosome. Males carrying the SD construct produce highly male-biased progenies without evident reduction in fertility. In this study, we investigated the fate of X and Y chromosomes in these SD males and found that ratios of mature X:Y-bearing sperm were comparable to wild-type insects, indicating absence of selection mechanisms during sperm maturation. We therefore tested the effect of meiotic cleavage of both X and Y chromosomes in a lab-generated SD strain carrying rDNA on both sex chromosomes, showing fertility comparable to wild-type and a reduced male-bias compared to SD males in which only the X is targeted. Exposure of Y-linked rDNA to I-PpoI cleavage for consecutive generations rapidly restored the male-bias to typical high frequencies, indicating a correlation between the number of cleavable targets in each sex chromosome and the sex-ratios found in the progeny. Altogether our results indicate that meiotic cleavage of rDNA repeats, located in the sex chromosomes of A. gambiae SD males, affects the competitiveness of mature sperm to fertilize the female oocyte, thereby generating sex-biased progenies. We also show that the presence of rDNA copies on the Y chromosome does not impair the effectiveness of engineered synthetic SD systems for the control of human malaria mosquitoes

Revisiting the Twentieth Century Through the Lens of Generation X and Digital Games: A Scoping Review

Video games have been around since the 1960s and have impacted upon society in a myriad of different ways. The purpose of this scoping review is to identify existing literature within the domain of video games which recruited participants from the Generation X (1965–1980) cohort. Six databases were searched (ACM, CINHAL Google Scholar, PubMed, Scopus, and Web of Science) focusing on published journal papers between 1970 and 2000. Search results identified 3186 articles guided by the PRISMA Extension for Scoping Reviews (PRISMA-ScR); 4 papers were irretrievable, 138 duplicated papers were removed, leaving 3048 were assessed for eligibility and 3026 were excluded. Articles (n = 22) were included into this review, with four papers primarily published in 1997 and in 1999. Thematic analysis identified five primary themes: purpose and objectives, respective authors’ reporting, technology, ethics and environment) and seven secondary themes: populations, type of participants (e.g. children, students), ethical approval, study design, reimbursement, language, type of assessments. This scoping review is distinctive because it primarily focuses on Generation X, who have experienced and grown-up with videogames, and contributes to several disciplines including: game studies, gerontology and health, and has wider implications from a societal, design and development perspective of video games

Development, feasibility, and acceptability of an intervention to improve care for agitation in people living in nursing homes with dementia nearing the end-of-life

OBJECTIVES: To develop a staff training intervention for agitation in people with severe dementia, reaching end-of-life, residing in nursing homes (NHs), test feasibility, acceptability, and whether a trial is warranted. DESIGN: Feasibility study with pre- and post-intervention data collection, qualitative interviews, and focus groups. SETTING: Three NHs in South East England with dementia units, diverse in terms of size, ownership status, and location. PARTICIPANTS: Residents with a dementia diagnosis or scoring ≥2 on the Noticeable Problems Checklist, rated as "severe" on Clinical Dementia Rating Scale, family carers, and staff (healthcare assistants and nurses). INTERVENTION: Manualized training, delivered by nonclinical psychology graduates focusing on agitation in severe dementia, underpinned by a palliative care framework. MEASUREMENTS: Main outcomes were feasibility of recruitment, data collection, follow-up, and intervention acceptability. We collected resident, family carer, and staff demographics. Staff provided data on resident's agitation, pain, quality of life, and service receipt. Staff reported their sense of competence in dementia care. Family carers reported on satisfaction with end-of-life care. In qualitative interviews, we explored staff and family carers' views on the intervention. RESULTS: The target three NHs participated: 28 (49%) residents, 53 (74%) staff, and 11 (85%) family carers who were eligible to participate consented. Eight-four percent of staff attended ≥3 sessions, and we achieved 93% follow-up. We were able to complete quantitative interviews. Staff and family carers reported the intervention and delivery were acceptable and helpful. CONCLUSIONS: The intervention was feasible and acceptable indicating a larger trial for effectiveness may be warranted

Identification of hepatitis a virus mimotopes by phage display, antigenicity and immunogenicity

A phage-displayed peptide approach was used to identify ligands mimicking antigenic determinants of hepatitis A virus (HAV) for the first time. Bacteriophages displaying HAV mimotopes were isolated from a phage-display peptide library by affinity selection on serum antibodies from hepatitis A patients. Selected phage-peptides were screened for reactivity with sera from HAV infected patients and healthy controls. Four cloned peptides with different sequences were identified as mimotopes of HAV; three of them showed similarity in their amino acid sequences with at least one of the VP3 and VP1 antigenic proteins of HAV. One clone was recognised by 92% of the positive sera. The phagotopes competed effectively with HAV for absorption of anti-HAV-specific antibodies in human sera, as determined by ELISA. The four phage clones induced neutralising anti-HAV antibodies in immunised mice. These results demonstrate the potential of this method to elucidate the disease related epitopes of HAV and to use these mimotopes in diagnostic applications or in the development of a mimotope-based hepatitis A vaccine without the necessity of manipulation of the virus

Axial distribution of myosin binding protein-C is unaffected by mutations in human cardiac and skeletal muscle

Myosin binding protein-C (MyBP-C), a major thick filament associated sarcomeric protein, plays an important functional and structural role in regulating sarcomere assembly and crossbridge formation. Missing or aberrant MyBP-C proteins (both cardiac and skeletal) have been shown to cause both cardiac and skeletal myopathies, thereby emphasising its importance for the normal functioning of the sarcomere. Mutations in cardiac MyBP-C are a major cause of hypertrophic cardiomyopathy (HCM), while mutations in skeletal MyBP-C have been implicated in a disease of skeletal muscle—distal arthrogryposis type 1 (DA-1). Here we report the first detailed electron microscopy studies on human cardiac and skeletal tissues carrying MyBP-C gene mutations, using samples obtained from HCM and DA-1 patients. We have used established image averaging methods to identify and study the axial distribution of MyBP-C on the thick filament by averaging profile plots of the A-band of the sarcomere from electron micrographs of human cardiac and skeletal myopathy specimens. Due to the difficulty of obtaining normal human tissue, we compared the distribution to the A-band structure in normal frog skeletal, rat cardiac muscle and in cardiac muscle of MyBP-C-deficient mice. Very similar overall profile averages were obtained from the C-zones in cardiac HCM samples and skeletal DA-1 samples with MyBP-C gene mutations, suggesting that mutations in MyBP-C do not alter its mean axial distribution along the thick filament

Healthcare resource utilisation and costs of agitation in people with dementia living in care homes in England - The Managing Agitation and Raising QUality of LifE in Dementia (MARQUE) study

BACKGROUND: People with dementia living in care homes often experience clinically significant agitation; however, little is known about its economic impact. OBJECTIVE: To calculate the cost of agitation in people with dementia living in care homes. METHODS: We used the baseline data from 1,424 residents with dementia living in care homes (part of Managing Agitation and Raising QUality of lifE in dementia (MARQUE) study) that had Cohen-Mansfield Agitation Inventory (CMAI) scores recorded. We investigated the relationship between residents' health and social care costs and severity of agitation based on the CMAI total score. In addition, we assessed resource utilisation and compared costs of residents with and without clinically significant symptoms of agitation using the CMAI over and above the cost of the care home. RESULTS: Agitation defined by the CMAI was a significant predictor of costs. On average, a one-point increase in the CMAI will lead to a 0.5 percentage points (cost ratio 1.005, 95%CI 1.001 to 1.010) increase in the annual costs. The excess annual cost associated with agitation per resident with dementia was £1,125.35. This suggests that, on average, agitation accounts for 44% of the annual health and social care costs of dementia in people living in care homes. CONCLUSION: Agitation in people with dementia living in care homes contributes significantly to the overall costs increasing as the level of agitation increases. Residents with the highest level of agitation cost nearly twice as much as those with the lowest levels of agitation, suggesting that effective strategies to reduce agitation are likely to be cost-effective in this setting

What role can videogames play in the COVID-19 pandemic?

Video games are often thought of as trite activities for younger generations. However, research in game studies over the last few decades have revealed that games can be valuable tools for growth and connection, particularly among older generations. Exploring the ways digital games can be used as tools for connection has gained increased attention in recent months with global quarantines as a result of COVID-19. This article reviews the research that has examined the utility of digital games for older adults, focusing specifically on the ways in which games can be tools for social connectedness and psychological healing for older adults and intergenerationally. Special focus will be placed on the role games can play for post-traumatic stress among first responders