220 research outputs found
Organoid Models and Next-Generation Sequencing for Bone Marrow and Related Disorders
Challenges to the musculoskeletal system negatively impact the quality of life of people suffering from them, leading to pain, a decline in mobility, genetic alterations, and potential disorders. The bone marrow (BM) forms an integral part of the musculoskeletal system responsible for erythropoiesis and optimal survival of the various immune and stem cells within the BM. However, due to its dynamic and complex three-dimensional (3D) structure, replicating the BM physiologically in traditional two-dimensional (2D) cell culture settings is often challenging, giving rise to the need for 3D in vitro models to better dissect the BM and its regeneration. Several researchers globally have been investigating various approaches to define an appropriate 3D model for their research. Organoids are novel preclinical models that provide a 3D platform for several tissues and have been analysed using next-generation sequencing (NGS) to identify new molecular pathways at the genetic level. The 3D in vitro models and organoids are increasingly considered important platforms for precision medicine. This review outlines the current knowledge of organoid and 3D in vitro models for the BM. We also discuss different types of 3D models which may be more adaptable for the BM. Finally, we critically review the NGS techniques used for such models and the future combination of these techniques
Histological variation of early stage atherosclerotic lesions in baboons after prolonged challenge with high-cholesterol, highfat diet
IntroductionâThe baboon is a well-characterized model of human early stage atherosclerosis. However, histological and morphological changes involved in atherogenesis in baboons are not known. Previously we challenged baboons with a high-cholesterol, high-fat diet for two years and observed fatty streak and plaque lesions in iliac arteries (RCIA). MethodsâWe evaluated histological and morphological changes of baboon arterial lesions and control arteries. In addition, we evaluated the vascular expression of CD68 and SMαA markers with progression of atherosclerosis. ResultsâWe observed changes that correlated with extent of atherosclerosis, including increased maximum intimal thickness. We demonstrated at molecular level the infiltration of smooth muscle cells and macrophages into the intimal layer. Further, we observed histological and morphological discordancy between the affected and adjacent areas of the same RCIA. ConclusionâAtherogenesis in baboons is accompanied by histological, morphological and molecular changes, as in humans, providing insights to evaluate the mechanisms underlying early stage atherosclerosis in target tissues
Diet-induced early-stage atherosclerosis in baboons: lipoproteins, atherogenesis, and arterial compliance
Background The purpose of this study was to determine if dietary manipulation can reliably induce early-stage atherosclerosis and clinically relevant changes in vascular function in an established, well-characterized nonhuman primate model. Methods We fed 112 baboons a high cholesterol, high fat challenge diet for two years. We assayed circulating biomarkers of cardiovascular disease (CVD) risk, at 0, 7, and 104 weeks into the challenge; assessed arterial compliance noninvasively at 104 weeks; and measured atherosclerotic lesions in three major arteries at necropsy. Results We observed evidence of atherosclerosis in all but one baboon fed the two-year challenge diet. CVD risk biomarkers, the prevalence, size, and complexity of arterial lesions, plus consequent arterial stiffness, were increased in comparison to dietary control animals. Conclusions Feeding baboons a high cholesterol, high fat diet for two years reliably induces atherosclerosis, with risk factor profiles, arterial lesions, and changes in vascular function also seen in humans
Duodenal adipose tissue is associated with obesity in baboons (Papio sp) : a novel site of ectopic fat deposition in non-human primates
AimsEctopic fat is a recognized contributor to insulin resistance and metabolic dysfunction, while the role of fat deposition inside intestinal wall tissue remains understudied. We undertook this study to directly quantify and localize intramural fat deposition in duodenal tissue and determine its association with adiposity.MethodsDuodenal tissues were collected from aged (21.21.3years, 19.53.1kg, n=39) female baboons (Papio sp.). Fasted blood was collected for metabolic profiling and abdominal circumference (AC) measurements were taken. Primary tissue samples were collected at the major duodenal papilla at necropsy: one full cross section was processed for hematoxylin and eosin staining and evaluated; a second full cross section was processed for direct chemical lipid analysis on which percentage duodenal fat content was calculated.Results Duodenal fat content obtained by direct tissue quantification showed considerable variability (11.95 +/- 6.93%) and was correlated with AC (r=0.60, p<0.001), weight (r=0.38, p=0.02), leptin (r=0.63, p<0.001), adiponectin (r=-0.32, p<0.05), and triglyceride (r=0.41, p=0.01). The relationship between duodenal fat content and leptin remained after adjusting for body weight and abdominal circumference. Intramural adipocytes were found in duodenal sections from all animals and were localized to the submucosa. Consistent with the variation in tissue fat content, the submucosal adipocytes were non-uniformly distributed in clusters of varying size. Duodenal adipocytes were larger in obese vs. lean animals (106.9 vs. 66.7 mu m(2), p=0.02).Conclusions Fat accumulation inside the duodenal wall is strongly associated with adiposity and adiposity related circulating biomarkers in baboons. Duodenal tissue fat represents a novel and potentially metabolically active site of ectopic fat deposition
InterGEO: a digital platform for university education on geomorphological heritage
The project InterGEO was carried out with the objective to disseminate knowledge on geomorphological heritage by developing a digital learning platform. It aims at improving students' autonomy by the reduction of face-to-face teaching and increasing autonomous learning as well as promoting international interactions between students interested in geomorphological heritage. A completely free-access virtual course on geomorphosites was developed with the Learning Management System Moodle. The course is divided into 24 thematic chapters, each of them containing a short description, a list of references and selected publications, as well as other educational material (videos, virtual fieldtrips, etc.). In particular, several videos allow presenting in a dynamic way concepts and examples. The paper presents the tool and its use in academic programmes in six European universities, where it was tested, in various contexts (Bachelors' and Masters' programmes; students in geography or geology; general courses in geomorphology and specific courses on geoheritage and geoconservation), before discussing the advantages and challenges the tool is facing. The InterGEO platform is an easy-to-use and friendly educational tool, which allows developing blended learning activities; it is flexible and adaptable in various learning contexts.The coordination tasks (appointment of an assistant) and two workshops in Lausanne were financed by the University of Lausanne (Teaching Innovation Fund and Investment Fund of the Faculty of Geosciences and Environment, FGSE). The videos were designed and created with support of the universities of Lausanne (TIF) and Savoie Mont Blanc (IDEFI Promising and ReflexPro; LabEx ITEM)
Measuring student attitude and knowledge in technology-rich biology classrooms
The use of technology in schools is now ubiquitous, but the effectiveness on the learning environment has mixed results. This paper describes the development and validation of an instrument to measure studentsâ attitudes toward and knowledge of technology with the aim of investigating any differences based on gender after a course where the science department made use of technology as an integral part of teaching biology. In this study, conducted in one school in the state of New York, in the United States of America, the Studentsâ Attitudes Toward and Knowledge of Technology Questionnaire was administered to nearly 700 high school science students. A principal component and principal factor analysis resulted in new scales from the validation of the instrument that demonstrated high reliabilities. There were statistically significant gender differences in all the scales of the questionnaire in favor of males
Development and characterisation of a large diameter decellularised vascular allograft
The aims of this study were to develop a biological large diameter vascular graft by decellularisation of native human aorta to remove the immunogenic cells whilst retaining the essential biomechanical, and biochemical properties for the ultimate benefit of patients with infected synthetic grafts. Donor aortas (n = 6) were subjected to an adaptation of a propriety decellularisation process to remove the cells and acellularity assessed by histological analysis and extraction and quantification of total DNA. The biocompatibility of the acellular aortas was determined using standard contact cytotoxicity tests. Collagen and denatured collagen content of aortas was determined and immunohistochemistry was used to determine the presence of specific extracellular matrix proteins. Donor aortas (n = 6) were divided into two, with one half subject to decellularisation and the other half retained as native tissue. The native and decellularised aorta sections were then subject to uniaxial tensile testing to failure [axial and circumferential directions] and suture retention testing. The data was compared using a paired t-test. Histological evaluation showed an absence of cells in the treated aortas and retention of histoarchitecture including elastin content. The decellularised aortas had less than 15 ng mgÂŻÂč total DNA per dry weight (mean 94% reduction) and were biocompatible as determined by in vitro contact cytotoxicity tests. There were no gross changes in the histoarchitecture [elastin and collagen matrix] of the acellular aortas compared to native controls. The decellularisation process also reduced calcium deposits within the tissue. The uniaxial tensile and suture retention testing revealed no significant differences in the material properties (p > 0.05) of decellularised aorta. The decellularisation procedure resulted in minimal changes to the biological and biomechanical properties of the donor aortas. Acellular donor aorta has excellent potential for use as a large diameter vascular graft
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