Osteomacs interact with megakaryocytes and osteoblasts to regulate murine hematopoietic stem cell function

Networking between hematopoietic stem cells (HSCs) and cells of the hematopoietic niche is critical for stem cell function and maintenance of the stem cell pool. We characterized calvariae-resident osteomacs (OMs) and their interaction with megakaryocytes to sustain HSC function and identified distinguishing properties between OMs and bone marrow (BM)–derived macrophages. OMs, identified as CD45+F4/80+ cells, were easily detectable (3%-5%) in neonatal calvarial cells. Coculture of neonatal calvarial cells with megakaryocytes for 7 days increased OM three- to sixfold, demonstrating that megakaryocytes regulate OM proliferation. OMs were required for the hematopoiesis-enhancing activity of osteoblasts, and this activity was augmented by megakaryocytes. Serial transplantation demonstrated that HSC repopulating potential was best maintained by in vitro cultures containing osteoblasts, OMs, and megakaryocytes. With or without megakaryocytes, BM-derived macrophages were unable to functionally substitute for neonatal calvarial cell–associated OMs. In addition, OMs differentiated into multinucleated, tartrate resistant acid phosphatase–positive osteoclasts capable of bone resorption. Nine-color flow cytometric analysis revealed that although BM-derived macrophages and OMs share many cell surface phenotypic similarities (CD45, F4/80, CD68, CD11b, Mac2, and Gr-1), only a subgroup of OMs coexpressed M-CSFR and CD166, thus providing a unique profile for OMs. CD169 was expressed by both OMs and BM-derived macrophages and therefore was not a distinguishing marker between these 2 cell types. These results demonstrate that OMs support HSC function and illustrate that megakaryocytes significantly augment the synergistic activity of osteoblasts and OMs. Furthermore, this report establishes for the first time that the crosstalk between OMs, osteoblasts, and megakaryocytes is a novel network supporting HSC function

Intentional injury reported by young people in the Federated States of Micronesia, Kingdom of Tonga and Vanuatu

<p>Abstract</p> <p>Background</p> <p>Intentional injury presents a threat to the physical and psychological well being of young people, especially in developing countries, which carry the greatest part of the global injury burden. While the importance of this problem is recognized, there are limited population data in low and middle income countries that can guide public health action. The present study investigates the prevalence and distribution of intentional injury among young people in three Pacific Island societies, and examines behavioural and psychosocial factors related to risk of intentional injury.</p> <p>Methods</p> <p>Population surveys were conducted with <b>s</b>tudents aged 11–17 years in Pohnpei State in the Federated States of Micronesia (n = 1495), the Kingdom of Tonga (n = 2808) and Vanuatu (n = 4474). Surveys measured self-reported injury and intentional injury, sources of intentional injury, and the range of behavioural, psychological, educational and social variables that may be related to injury risk.</p> <p>Results</p> <p>Among boys and girls aged 14–17 years the respective period prevalence of intentional injury was 62% and 56% in Pohnpei, 58% and 41% in Tonga, and 33% and 24% in Vanuatu. The prevalence of intentional injury declined with age in Tonga and Vanuatu, but there was little evidence of an age-trend in Pohnpei. Across the three societies, the major sources of intentional injury among boys were 'other persons' followed by boyfriends/girlfriends and fathers. Mothers, boyfriends/girlfriends and other persons were primary sources of injury among girls. An intentional injury was reported more often by those who had been bullied (OR 1.40–1.66, P < 0.05), by regular smokers in Tonga and Vanuatu (OR 1.52–2.21, P < 0.05), and illicit drug users in Pohnpei and Vanuatu (OR 1.87–1.92, P < 0.05).</p> <p>Conclusion</p> <p>Intentional injury was reported extensively in these three populations. Interventions directed towards the school environment and which take into account the role of bullying and drug use need to be considered.</p

Sendai five years on: reflections on the role of international law in the creation and reduction of disaster risk

This article offers a critical examination of the position of the Sendai Framework for Disaster Risk Reduction 2015-2030 within international law. It is argued that any interrogation into the role of international law must begin not with existing disaster risk reduction (DRR) laws and policies, but rather with an enquiry into the nature of disaster risk and the role of international law in its creation and reduction. It is demonstrated how, while areas such as international human rights law can be utilized to enforce obligations in support of DRR, other areas – in particular international investment law – actively work to undermine DRR efforts. In order for international law to be a productive tool in the reduction of disaster risk international lawyers must engage with critical work in disaster studies in order to explore the role that the former has played – and can play – in creating and addressing hazards, vulnerabilities and capacities

Hospital-Based and Freestanding Skilled Nursing Facilities: Any Cause for Differential Medicare Payments?

Differential Medicare payments for hospital-based and freestanding skilled nursing facilities (SNFs) were eliminated by the SNF prospective payment system initiated in 1998. Closures and high negative margins of hospital-based facilities have prompted consideration of the need to revisit payment adjustments for this group of SNFs. We examine case mix-related and other factors behind the cost differences between hospital-based and freestanding SNFs. Some payment adjustment, notably for nontherapy ancillary services, may be reasonable for the short term

Mapping children’s neighborhood perceptions: Implications for child indicators

Abstract A growing literature on small-area effects has linked neighborhood conditions with indicators of child well-being. This paper addresses some of the challenges in identifying and understanding these linkages, with a focus on children&apos;s definitions and perceptions of their neighborhood geographies. The study included 60 children aged 7 to 11 and one of their parents in five neighborhoods (census tracts). Neighborhood maps were elicited from both children and parents. Child and parent maps showed only a modest correlation, suggesting that children have their own conceptions of their neighborhoods. Also, home range was not equated with children&apos;s definitions of neighborhood boundaries. Accurate and meaningful measures of neighborhood, including child-centered measures, are needed. Child-centered neighborhood indicators are an important complement to the measures that are increasingly available for standard neighborhood units. The neighborhood is a potentially important context for improving child well-being by developing area-based programs to address spatial inequality in child well-being

Studies on genes coding the firmness of strawberry (Fragaria x ananassa) fruits

Metabolizm komponentów polisacharydowych ściany komórkowej wpływa na wiele cech fenotypowych i fizjologicznych roślin, m.in. na zmiany jędrności owoców podczas ich dojrzewania. Celem badań podjętych w 2001 roku w Zakładzie Hodowli Instytutu Sadownictwa i Kwiaciarstwa było określenie, który z genów regulujących gospodarkę celulozowo-pektynową warunkuje równocześnie jędrność owoców jako cechę typową dla każdej z odmian truskawki. Badania prowadzono na genomowym DNA i cDNA truskawki 'Dukat' oraz czterech innych odmian różniących się jędrnością owoców ('Kama', 'Kent', 'Vikat', 'Salut'). W zoptymalizowanych warunkach PCR w reakcji ze starterami celU1.2/L1.2 i expUl/Ll-3 (konstrukcja na podstawie biblioteki cDNA truskawki) uzyskano produkty o długości około 3 kb i 1,2 kb (matryca: genomowe DNA) oraz 1,5 kb i 800 pz (matryca: cDNA). Wyniki sekwencjonowania produktów PCR potwierdziły, iż wyizolowane fragmenty zawierały geny celulazy i ekspansyny (86-99% homologii z sekwencjami genów podanych w Banku Genów dla roślin innych gatunków/odmian). Prace nad porównaniem sekwencji produktów PCR uzyskanych dla pozostałych analizowanych odmian są kontynuowane.Metabolism of polysaccharides in cell wall influences many phenotypic and physiological plant traits, e.g. the changes in fruit firmness during ripening. The aim of studies carried out in the Fruit Breeding Department was searching for genes responsible for cellulose - pectin transformations simultaneously regulating strawberry fruit firmness typical for each cultivar. Genomic DNA and cDNA of 'Dukat' strawberry and four other cultivars of different firmness level ('Kama', 'Kent', Vikať, 'Salut') were used as a template for PCR with primers constructed on the basis of strawberry cDNA library. Under optimised PCR conditions the products of length about of 3 kb and 1.2 kb (genomic DNA) and 1.5 kb and 800 bp (cDNA) were obtained respectively in reactions with primers celU1.2/L1.2 and expUl/Ll-3. Results of PCR product sequencing confirmed that isolated DNA fragments contained cellulase and expansin genes (86-99% homology with published in Genebank sequences of other species/cultivars). Comparable studies on PCR product sequences obtained for the other genotypes are continued

Children and families in communities: theory, research policy and practice

Book synopsis: In the past decade the relationship between communities, children and families has inspired a wealth of research and policy initiatives because of a growing belief that the breakdown of families and communities is a significant factor in social problems, including child abuse and juvenile crime. The latest policy initiatives to tackle social problems have therefore targeted communities as well as high risk families. This title amalgamates the latest research on the relationship between children, families and communities and explores policy and practice implications. Material for practitioners and community development workers is also be included. The book is divided in to three parts: 1) theory 2) the effect of community on children, parents and families 3) interventions and policy implications

On the choice of international joint venture: the role of policy moral hazard

This paper examines the choice problem facing a multinational firm, whether to establish a wholly owned subsidiary or form a joint venture with a firm from the host country, as the mode of direct foreign investment. It is shown that, all other considerations aside, the prospect of policy variation toward the venture (restrictive or conducive), which is called policy moral hazard facing the host government, is a factor for joint venture to emerge as the preferred option.direct, foreign investment, joint venture, multinational firm, moral hazard, host country policy,