185 research outputs found

    Skeletogenesis and the Hematopoietic Niche

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    Influence of the technology of processing of meat of snails in anabiosis on the content of toxic elements

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    An important problem today is the pollution of the territory of Ukraine with heavy metals: lead, cadmium, copper, zinc and others. Relevance of the topic is that nowadays the issues of safety and quality control are not fully resolved in the country, as well as the veterinary and sanitary assessment of the meat of snails of the genus Helix, which are used for food purposes; in particular, there is no data on the content of toxic elements in a meat of different species of snails for different processing modes. The aim of the study was to investigate the meat of snails of the genus Helix for different processing to find heavy metals in it. The meat of snails of genus Helix has been used for the study, sub-species: Helix pomatia, Helix aspersa maxima and Helix aspersa muller. 30 samples of snails of each species grown in snails farm in the Kyiv region have been selected for the study. Meat of snails has been studied after different technological processing: live, chilled, and cooked and frozen (n = 30). The research has been conducted in the winter, when the snails have been in anabiosis. Results of the study show that in accordance with the requirements of DSTU 7821:2016 “Live edible gastropod molluscs. Specifications”, the content of toxic elements in the meat of live snails corresponds to the maximum allowable level. One of the key indicators of safety of meat, in accordance with the requirements of DSTU 7821:2016, is the content of toxic elements in it: lead, cadmium, copper, zinc. It has been found that the meat of snails, in addition to the above mentioned heavy metals, contains also arsenic and iron, which relate to toxic elements as well. Therefore, when developing a complex system of veterinary and sanitary assessment of quality and safety of snails’ meat, we propose to control it on the content of such toxic elements as arsenic and iron. In addition, we recommend to improve the “The Required Minimum List…” (2004) with the studies of the meat of snails of the genus Helix for different technological processing on the content of toxic elements: lead, cadmium, copper, zinc, arsenic and iron

    Congenic Mice Confirm That Collagen X Is Required for Proper Hematopoietic Development

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    The link between endochondral skeletal development and hematopoiesis in the marrow was established in the collagen X transgenic (Tg) and null (KO) mice. Disrupted function of collagen X, a major hypertrophic cartilage matrix protein, resulted in skeletal and hematopoietic defects in endochondrally derived tissues. Manifestation of the disease phenotype was variable, ranging from perinatal lethality in a subset of mice, to altered lymphopoiesis and impaired immunity in the surviving mice. To exclude contribution of strain specific modifiers to this variable manifestation of the skeleto-hematopoietic phenotype, C57Bl/6 and DBA/2J collagen X congenic lines were established. Comparable disease manifestations confirmed that the skeleto-hematopoietic alterations are an inherent outcome of disrupted collagen X function. Further, colony forming cell assays, complete blood count analysis, serum antibody ELISA, and organ outgrowth studies established altered lymphopoiesis in all collagen X Tg and KO mice and implicated opportunistic infection as a contributor to the severe disease phenotype. These data support a model where endochondral ossification-specific collagen X contributes to the establishment of a hematopoietic niche at the chondro-osseous junction

    Collagen Structure-Function Mapping Informs Applications for Regenerative Medicine.

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    Type I collagen, the predominant protein of vertebrates, assembles into fibrils that orchestrate the form and function of bone, tendon, skin, and other tissues. Collagen plays roles in hemostasis, wound healing, angiogenesis, and biomineralization, and its dysfunction contributes to fibrosis, atherosclerosis, cancer metastasis, and brittle bone disease. To elucidate the type I collagen structure-function relationship, we constructed a type I collagen fibril interactome, including its functional sites and disease-associated mutations. When projected onto an X-ray diffraction model of the native collagen microfibril, data revealed a matrix interaction domain that assumes structural roles including collagen assembly, crosslinking, proteoglycan (PG) binding, and mineralization, and the cell interaction domain supporting dynamic aspects of collagen biology such as hemostasis, tissue remodeling, and cell adhesion. Our type III collagen interactome corroborates this model. We propose that in quiescent tissues, the fibril projects a structural face; however, tissue injury releases blood into the collagenous stroma, triggering exposure of the fibrils\u27 cell and ligand binding sites crucial for tissue remodeling and regeneration. Applications of our research include discovery of anti-fibrotic antibodies and elucidating their interactions with collagen, and using insights from our angiogenesis studies and collagen structure-function model to inform the design of super-angiogenic collagens and collagen mimetics

    The Importance of Accountability for Innovation Development Viewed Through the Mediating Role of Intellectual Capital

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    Although the concept of accountability itself is not new and in the literature, it appeared about 40 years ago, business has started to realize its importance only recently. Accountability can be understood differently in English or nonEnglish languages. The examples of the most innovative companies demonstrate the culture with the characteristics of accountable organizations. Their innovation is in their culture and employees. Accountability as the important element of intellectual capital has the linkage to the innovation. Time will show if market and business are interested in the evaluation of accountability and its presentation in financial statements. The aim of the paper is to present the importance of accountability for innovation development as mediated by organizational culture and intellectual capital. It presents the theoretical concept of accountability as success factor of the innovation

    Abnormal compartmentalization of cartilage matrix components in mice lacking collagen X: Implications for function

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    There are conflicting views on whether collagen X is a purely structural molecule, or regulates bone mineralization during endochondral ossification. Mutations is the human collagen α1(X) gene (COL10A1) in Schmid metaphyseal chondrodysplasia (SMCD) suggest a supportive role. But mouse collagen α1(X) gene (Col10A1) null mutants were previously reported to show no obvious phenotypic change. We have generated collagen X deficient mice, which shows that deficiency does have phenotypic consequences which partly resemble SMCD, such as abnormal trabecular bone architecture. In particular, the mutant mice develop coxa vara, a phenotypic change common in human SMCD. Other consequences of the mutation are reduction in thickness of growth plate resting zone and articular cartilage, altered bone content, and atypical distribution of matrix components within growth plate cartilage. We propose that collagen X plays a role in the normal distribution of matrix vesicles and proteoglycans within the growth plate matrix. Collagen X deficiency impacts on the supporting properties of the growth plate and the mineralization process, resulting in abnormal trabecular bone. This hypothesis would accommodate the previously conflicting views of the function of collagen X and of the molecular pathogenesis of SMCD.published_or_final_versio

    Surviving Endoplasmic Reticulum Stress Is Coupled to Altered Chondrocyte Differentiation and Function

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    In protein folding and secretion disorders, activation of endoplasmic reticulum (ER) stress signaling (ERSS) protects cells, alleviating stress that would otherwise trigger apoptosis. Whether the stress-surviving cells resume normal function is not known. We studied the in vivo impact of ER stress in terminally differentiating hypertrophic chondrocytes (HCs) during endochondral bone formation. In transgenic mice expressing mutant collagen X as a consequence of a 13-base pair deletion in Col10a1 (13del), misfolded α1(X) chains accumulate in HCs and elicit ERSS. Histological and gene expression analyses showed that these chondrocytes survived ER stress, but terminal differentiation is interrupted, and endochondral bone formation is delayed, producing a chondrodysplasia phenotype. This altered differentiation involves cell-cycle re-entry, the re-expression of genes characteristic of a prehypertrophic-like state, and is cell-autonomous. Concomitantly, expression of Col10a1 and 13del mRNAs are reduced, and ER stress is alleviated. ERSS, abnormal chondrocyte differentiation, and altered growth plate architecture also occur in mice expressing mutant collagen II and aggrecan. Alteration of the differentiation program in chondrocytes expressing unfolded or misfolded proteins may be part of an adaptive response that facilitates survival and recovery from the ensuing ER stress. However, the altered differentiation disrupts the highly coordinated events of endochondral ossification culminating in chondrodysplasia

    Bone growth during rapamycin therapy in young rats

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    <p>Abstract</p> <p>Background</p> <p>Rapamycin is an effective immunosuppressant widely used to maintain the renal allograft in pediatric patients. Linear growth may be adversely affected in young children since rapamycin has potent anti-proliferative and anti-angiogenic properties.</p> <p>Methods</p> <p>Weanling three week old rats were given rapamycin at 2.5 mg/kg daily by gavage for 2 or 4 weeks and compared to a Control group given equivalent amount of saline. Morphometric measurements and biochemical determinations for serum calcium, phosphate, iPTH, urea nitrogen, creatinine and insulin-growth factor I (IGF-I) were obtained. Histomorphometric analysis of the growth plate cartilage, in-situ hybridization experiments and immunohistochemical studies for various proteins were performed to evaluate for chondrocyte proliferation, chondrocyte differentiation and chondro/osteoclastic resorption.</p> <p>Results</p> <p>At the end of the 2 weeks, body and tibia length measurements were shorter after rapamycin therapy associated with an enlargement of the hypertrophic zone in the growth plate cartilage. There was a decrease in chondrocyte proliferation assessed by <it>histone-4 </it>and <it>mammalian target of rapamycin </it>(<it>mTOR</it>) expression. A reduction in <it>parathyroid hormone/parathyroid hormone related peptide (PTH/PTHrP) </it>and an increase in <it>Indian hedgehog </it>(<it>Ihh</it>) expression may explain in part, the increase number of hypertrophic chondrocytes. The number of TRAP positive multinucleated chondro/osteoclasts declined in the chondro-osseous junction with a decrease in the <it>receptor activator of nuclear factor kappa β ligand </it>(<it>RANKL</it>) and <it>vascular endothelial growth factor </it>(<it>VEGF</it>) expression. Although body and tibial length remained short after 4 weeks of rapamycin, changes in the expression of chondrocyte proliferation, chondrocyte differentiation and chondro/osteoclastic resorption which were significant after 2 weeks of rapamycin improved at the end of 4 weeks.</p> <p>Conclusion</p> <p>When given to young rats, 2 weeks of rapamycin significantly decreased endochondral bone growth. No catch-up growth was demonstrated at the end of 4 weeks, although markers of chondrocyte proliferation and differentiation improved. Clinical studies need to be done to evaluate these changes in growing children.</p
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