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That the highly trabeculated ventricular walls of the developing embryos transform to the arrangement during the fetal stages, when the mural architecture is dominated by the thickness of the compact myocardium, has been explained by the coalescence of trabeculations, often erroneously described as 'compaction'. Recent data, however, support differential rates of growth of the trabecular and compact layers as the major driver of change. Here, these processes were assessed quantitatively and visualized in standardized views. We used a larger dataset than has previously been available of mouse hearts, covering the period from embryonic day 10.5 to postnatal day 3, supported by images from human hearts. The volume of the trabecular layer increased throughout development, in contrast to what would be expected had there been 'compaction'. During the transition from embryonic to fetal life, the rapid growth of the compact layer diminished the proportion of trabeculations. Similarly, great expansion of the central cavity reduced the proportion of the total cavity made up of intertrabecular recesses. Illustrations of the hearts with the median value of left ventricular trabeculation confirm a pronounced growth of the compact wall, with prominence of the central cavity. This corresponds, in morphological terms, to a reduction in the extent of the trabecular layer. Similar observations were made in the human hearts. We conclude that it is a period of comparatively slow growth of the trabecular layer, rather than so-called compaction, that is the major determinant of the changing morphology of the ventricular walls of both mouse and human hearts.
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Ventrículos do Coração , Animais , Humanos , Camundongos , Ventrículos do Coração/anatomia & histologia , Ventrículos do Coração/embriologia , Idade GestacionalRESUMO
BACKGROUND: During amphibian metamorphosis, the crucial moment lies in the rearrangement of the heart, reflecting the changes in circulatory demands. However, little is known about the exact shifts linked with this rearrangement. Here, we demonstrate such myocardial changes in axolotl (Ambystoma mexicanum) from the morphological and physiological point of view. RESULTS: Micro-CT and histological analysis showed changes in ventricular trabeculae organization, completion of the atrial septum and its connection to the atrioventricular valve. Based on Myosin Heavy Chain and Smooth Muscle Actin expression we distinguished metamorphosis-induced changes in myocardial differentiation at the ventricular trabeculae and atrioventricular canal. Using optical mapping, faster speed of conduction through the atrioventricular canal was demonstrated in metamorphic animals. No differences between the groups were observed in the heart rates, ventricular activation times, and activation patterns. CONCLUSIONS: Transition from aquatic to terrestrial life-style is reflected in the heart morphology and function. Rebuilding of the axolotl heart during metamorphosis was connected with reorganization of ventricular trabeculae, completion of the atrial septum and its connection to the atrioventricular valve, and acceleration of AV conduction.
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Ambystoma mexicanum , Coração , Ambystoma mexicanum/fisiologia , Animais , Evolução Biológica , Metamorfose Biológica/fisiologia , MiocárdioRESUMO
BACKGROUND: The ventricular trabeculae play a role, among others, in the impulse spreading in ectothermic hearts. Despite the morphological similarity with the early developing hearts of endotherms, this trabecular function in mammalian and avian embryos was poorly addressed. RESULTS: We simulated impulse propagation inside the looping ventricle and revealed delayed apical activation in the heart with inhibited trabecular growth. This finding was corroborated by direct imaging of the endocardial surface showing early activation within the trabeculae implying preferential spreading of depolarization along with them. Targeting two crucial pathways of trabecular formation (Neuregulin/ErbB and Nkx2.5), we showed that trabecular development is also essential for proper conduction patterning. Persistence of the slow isotropic conduction likely contributed to the pumping failure in the trabeculae-deficient hearts. CONCLUSIONS: Our results showed the essential role of trabeculae in intraventricular impulse spreading and conduction patterning in the early endothermic heart. Lack of trabeculae leads to the failure of conduction parameters differentiation resulting in primitive ventricular activation with consequent impact on the cardiac pumping function.
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The molecular mechanisms regulating sympathetic innervation of the heart during embryogenesis and its importance for cardiac development and function remain to be fully elucidated. We generated mice in which conditional knockout (CKO) of the Hif1a gene encoding the transcription factor hypoxia-inducible factor 1α (HIF-1α) is mediated by an Islet1-Cre transgene expressed in the cardiac outflow tract, right ventricle and atrium, pharyngeal mesoderm, peripheral neurons, and hindlimbs. These Hif1aCKO mice demonstrate significantly decreased perinatal survival and impaired left ventricular function. The absence of HIF-1α impaired the survival and proliferation of preganglionic and postganglionic neurons of the sympathetic system, respectively. These defects resulted in hypoplasia of the sympathetic ganglion chain and decreased sympathetic innervation of the Hif1aCKO heart, which was associated with decreased cardiac contractility. The number of chromaffin cells in the adrenal medulla was also decreased, indicating a broad dependence on HIF-1α for development of the sympathetic nervous system.
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Subunidade alfa do Fator 1 Induzível por Hipóxia/fisiologia , Sistema Nervoso Simpático/crescimento & desenvolvimento , Medula Suprarrenal/embriologia , Medula Suprarrenal/inervação , Animais , Células Cromafins , Anomalias dos Vasos Coronários/embriologia , Vasos Coronários/embriologia , Feminino , Gânglios Simpáticos/embriologia , Gânglios Simpáticos/crescimento & desenvolvimento , Coração/embriologia , Coração/inervação , Masculino , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Sistema Nervoso Simpático/enzimologiaRESUMO
The increasing incidence of trauma in medicine brings with it new demands on the materials used for the surgical treatment of bone fractures. Titanium, its alloys, and steel are used worldwide in the treatment of skeletal injuries. These metallic materials, although inert, are often removed after the injured bone has healed. The second-stage procedure-the removal of the plates and screws-can overwhelm patients and overload healthcare systems. The development of suitable absorbable metallic materials would help us to overcome these issues. In this experimental study, we analyzed an extruded Zn-0.8Mg-0.2Sr (wt.%) alloy on a rabbit model. From this alloy we developed screws which were implanted into the rabbit tibia. After 120, 240, and 360 days, we tested the toxicity at the site of implantation and also within the vital organs: the liver, kidneys, and brain. The results were compared with a control group, implanted with a Ti-based screw and sacrificed after 360 days. The samples were analyzed using X-ray, micro-CT, and a scanning electron microscope. Chemical analysis revealed only small concentrations of zinc, strontium, and magnesium in the liver, kidneys, and brain. Histologically, the alloy was verified to possess very good biocompatibility after 360 days, without any signs of toxicity at the site of implantation. We did not observe raised levels of Sr, Zn, or Mg in any of the vital organs when compared with the Ti group at 360 days. The material was found to slowly degrade in vivo, forming solid corrosion products on its surface.
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Implantes Absorvíveis , Ligas , Teste de Materiais , Tíbia/metabolismo , Fraturas da Tíbia , Ligas/química , Ligas/farmacocinética , Ligas/farmacologia , Animais , Humanos , Magnésio/química , Magnésio/farmacocinética , Magnésio/farmacologia , Coelhos , Estrôncio/química , Estrôncio/farmacocinética , Estrôncio/farmacologia , Tíbia/patologia , Fraturas da Tíbia/metabolismo , Fraturas da Tíbia/cirurgia , Zinco/química , Zinco/farmacocinética , Zinco/farmacologiaRESUMO
The aim of this work was to investigate and quantitatively evaluate the effect of presence of alcohol on in vitro release of ionizing and non-ionizing drug from hydrophilic, lipophilic and hydrophilic-lipophilic matrix tablets. The Food and Drug Administration (FDA) recommends in vitro dissolution testing of extended release formulations in ethanolic media up to 40% because of possible alcohol-induced dose dumping effect. This study is focused on comparison of the dissolution behavior of matrix tablets (based on hypromellose and/or glyceryl behenate as retarding agent) of the same composition containing different type of drug - ionizing tramadol hydrochloride (TH) and non-ionizing pentoxifylline (PTX). The dissolution tests were performed in acidic medium (pH 1.2) and in alcoholic medim (20%, 40% of ethanol) and the changes of tablets were observed also photographically. It was found that the alcohol resistence of the hydrophilic-lipophilic formulations with TH and the hydrophilic-lipophilic formulations with PTX containing a higher amount of hypromellose does not reflect the alcohol resistence of the formulations with pure hypromellose or glyceryl behenate. Both hydrophilic-lipophilic formulation with TH and more lipophilic formulation with PTX show significant alcohol dose dumping effect.
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One of the main aims of bone tissue engineering, regenerative medicine and cell therapy is development of an optimal artificial environment (scaffold) that can trigger a favorable response within the host tissue, it is well colonized by resident cells of organism and ideally, it can be in vitro pre-colonized by cells of interest to intensify the process of tissue regeneration. The aim of this study was to develop an effective tool for regenerative medicine, which combines the optimal bone-like scaffold and colonization technique suitable for cell application. Accordingly, this study includes material (physical, chemical and structural) and in vitro biological evaluation of scaffolds prior to in vivo study. Thus, porosity, permeability or elasticity of two types of bone-like scaffolds differing in the ratio of collagen type I and natural calcium phosphate nanoparticles (bCaP) were determined, then analyzes of scaffold interaction with mesenchymal stem cells (MSCs) were performed. Simultaneously, dynamic seeding using a perfusion bioreactor followed by static cultivation was compared with standard static cultivation for the whole period of cultivation. In summary, cell colonization ability was estimated by determination of cell distribution within the scaffold (number, depth and homogeneity), matrix metalloproteinase activity and gene expression analysis of signaling molecules and differentiation markers. Results showed, the used dynamic colonization technique together with the newly-developed collagen-based scaffold with high content of bCaP to be an effective combined tool for producing bone grafts for bone implantology and regenerative medicine.
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Fosfatos de Cálcio/metabolismo , Células-Tronco Mesenquimais/metabolismo , Engenharia Tecidual/métodos , Animais , Osso e Ossos/química , Diferenciação Celular , Células Cultivadas , Colágeno/química , Feminino , Transplante de Células-Tronco Mesenquimais/métodos , Nanopartículas , Osteogênese/efeitos dos fármacos , Medicina Regenerativa , Suínos , Alicerces Teciduais/químicaRESUMO
The dentin-enamel junction (DEJ) is the border where two different mineralized structures - enamel and dentin - meet. The protein-rich DEJ, together with the inner enamel region of mature teeth, is known to exhibit higher fracture toughness and crack growth resistance than bulk phase enamel. However, an explanation for this behavior has been hampered by the lack of compositional information for the DEJ and the adjacent enamel organic matrix (EOM). We studied proteomes of the DEJ and EOM of healthy human molars and compared them with dentin and enamel proteomes from the same teeth. These tissues were cut out of tooth sections by laser capture microdissection, proteins were extracted and cleaved by trypsin, then processed by liquid chromatography coupled to tandem mass spectrometry to analyze the proteome profiles of these tissues. This study identified 46 proteins in DEJ and EOM. The proteins identified have a variety of functions, including calcium ion-binding, formation of extracellular matrix, formation of cytoskeleton, cytoskeletal protein binding, cell adhesion, and transport. Collagens were identified as the most dominant proteins. Tissue-specific proteins, such as ameloblastin and amelogenin, were also detected. Our findings reveal new insight into proteomics of DEJ and EOM, highly mineralized tissues that are obviously difficult to analyze.
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Esmalte Dentário , Dentina , Dente Molar , Proteoma/análise , Proteômica/métodos , Cromatografia Líquida , Humanos , Microdissecção , Proteínas/metabolismo , Espectrometria de Massas em TandemRESUMO
BACKGROUND: Coronary artery development is an intensely studied field. Mice are a popular genetic model for developmental studies, but there is no widely accepted protocol for high-throughput, high-resolution imaging of their developmental and adult coronary artery anatomy. RESULTS: Using tissue-clearing protocols and confocal microscopy, we have analyzed embryonic and juvenile mouse hearts in Cx40:GFP knock-in models with a special focus on septal artery development. We found that the septal artery, which supplies the interventricular septum, was initially formed as an arterial plexus that connected to both the left and right coronary arteries. During development, the plexus was remodeled into a single tube, which then remained connected only to the right coronary artery. Since optical imaging became limited at postnatal stages, it was supplemented with injection techniques using India ink and Microfil; the latter was subsequently analyzed with micro-CT to visualize the anatomy of coronary vessels in 3D. CONCLUSIONS: The techniques described here enable us to study the finer details of coronary artery development in mice and can, therefore, be implemented to study the pathogenesis of coronary malformations in various mouse models. Developmental Dynamics 247:1018-1027, 2018. © 2018 Wiley Periodicals, Inc.
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Vasos Coronários/crescimento & desenvolvimento , Animais , Vasos Coronários/anatomia & histologia , Embrião de Mamíferos , Septos Cardíacos , Imageamento Tridimensional/métodos , Camundongos , Microscopia Confocal/métodosRESUMO
3D super-resolution microscopy based on the direct stochastic optical reconstruction microscopy (dSTORM) with primary Alexa-Fluor-647-conjugated antibodies is a powerful method for accessing changes of objects that could be normally resolved only by electron microscopy. Despite the fact that mitochondrial cristae yet to become resolved, we have indicated changes in cristae width and/or morphology by dSTORM of ATP-synthase F1 subunit α (F1α). Obtained 3D images were analyzed with the help of Ripley's K-function modeling spatial patterns or transferring them into distance distribution function. Resulting histograms of distances frequency distribution provide most frequent distances (MFD) between the localized single antibody molecules. In fasting state of model pancreatic ß-cells, INS-1E, MFD between F1α were ~80â¯nm at 0 and 3â¯mM glucose, whereas decreased to 61â¯nm and 57â¯nm upon glucose-stimulated insulin secretion (GSIS) at 11â¯mM and 20â¯mM glucose, respectively. Shorter F1α interdistances reflected cristae width decrease upon GSIS, since such repositioning of F1α correlated to average 20â¯nm and 15â¯nm cristae width at 0 and 3â¯mM glucose, and 9â¯nm or 8â¯nm after higher glucose simulating GSIS (11, 20â¯mM glucose, respectively). Also, submitochondrial entities such as nucleoids of mtDNA were resolved e.g. after bromo-deoxyuridine (BrDU) pretreatment using anti-BrDU dSTORM. MFD in distances distribution histograms reflected an average nucleoid diameter (<100â¯nm) and average distances between nucleoids (~1000â¯nm). Double channel PALM/dSTORM with Eos-lactamase-ß plus anti-TFAM dSTORM confirmed the latter average inter-nucleoid distance. In conclusion, 3D single molecule (dSTORM) microscopy is a reasonable tool for studying mitochondrion.
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DNA Mitocondrial/química , DNA Mitocondrial/metabolismo , Proteínas de Ligação a DNA/metabolismo , Imageamento Tridimensional/métodos , Microscopia de Fluorescência/instrumentação , Membranas Mitocondriais/metabolismo , Animais , Células Cultivadas , Células Hep G2 , Humanos , Células Secretoras de Insulina/citologia , Células Secretoras de Insulina/metabolismo , Proteínas Mitocondriais/metabolismo , Ratos , Ratos WistarRESUMO
BACKGROUND: Collagen-based scaffolds provide a promising option for the treatment of bone defects. One of the key parameters of such scaffolds consists of porosity, including pore size. However, to date, no agreement has been found with respect to the methodology for pore size evaluation. Since the determination of the exact pore size value is not possible, the comparison of the various methods applied is complicated. Hence, this study focuses on the comparison of two widely-used methods for the characterization of porosity-scanning electron microscopy (SEM) and micro-computed tomography (micro-CT). METHODS: 7 types of collagen-based composite scaffold models were prepared by means of lyophilization and collagen cross-linking. Micro-CT analysis was performed in 3D and in 2D (pore size parameters were: major diameter, mean thickness, biggest inner circle diameter and area-equivalent circle diameter). Afterwards, pore sizes were analyzed in the same specimens by an image analysis of SEM microphotographs. The results were statistically evaluated. The comparison of the various approaches to the evaluation of pore size was based on coefficients of variance and the semi-quantitative assessment of selected qualities (e.g. the potential for direct 3D analysis, whole specimen analysis, non-destructivity). RESULTS: The pore size values differed significantly with respect to the parameters applied. Median values of pore size values were ranging from 20 to 490 µm. The SEM values were approximately 3 times higher than micro-CT 3D values for each specimen. The Mean thickness was the most advantageous micro-CT 2D approach. Coefficient of variance revealed no differences among pore size parameters (except major diameter). The semi-quantitative comparison approach presented pore size parameters in descending order with regard to the advantages thereof as follows: (1) micro-CT 3D, (2) mean thickness and SEM, (3) biggest inner circle diameter, major diameter and area equivalent circle diameter. CONCLUSION: The results indicated that micro-CT 3D evaluation provides the most beneficial overall approach. Micro-CT 2D analysis (mean thickness) is advantageous in terms of its time efficacy. SEM is still considered as gold standard for its widespread use and high resolution. However, exact comparison of pore size analysis in scaffold materials remains a challenge.
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Engenharia Tecidual , Alicerces Teciduais , Colágeno/química , Porosidade , Microtomografia por Raio-XRESUMO
Collagen composite scaffolds have been used for a number of studies in tissue engineering. The hydration of such highly porous and hydrophilic structures may influence mechanical behaviour and porosity due to swelling. The differences in physical properties following hydration would represent a significant limiting factor for the seeding, growth and differentiation of cells in vitro and the overall applicability of such hydrophilic materials in vivo. Scaffolds based on collagen matrix, poly(DL-lactide) nanofibers, calcium phosphate particles and sodium hyaluronate with 8 different material compositions were characterised in the dry and hydrated states using X-ray microcomputed tomography, compression tests, hydraulic permeability measurement, degradation tests and infrared spectrometry. Hydration, simulating the conditions of cell seeding and cultivation up to 48 h and 576 h, was found to exert a minor effect on the morphological parameters and permeability. Conversely, hydration had a major statistically significant effect on the mechanical behaviour of all the tested scaffolds. The elastic modulus and compressive strength of all the scaffolds decreased by ~95%. The quantitative results provided confirm the importance of analysing scaffolds in the hydrated rather than the dry state since the former more precisely simulates the real environment for which such materials are designed.
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Colágeno/química , Dessecação , Alicerces Teciduais/química , Água/química , Materiais Biocompatíveis/química , Fosfatos de Cálcio/química , Força Compressiva , Módulo de Elasticidade , Ácido Hialurônico/química , Teste de Materiais , Fenômenos Mecânicos , Poliésteres/química , Porosidade , Engenharia Tecidual/métodos , Microtomografia por Raio-XRESUMO
Introduction: Obtaining real-world data from routine clinical care is of growing interest for scientific research and personalized medicine. Despite the abundance of medical data across various facilities - including hospitals, outpatient clinics, and physician practices - the intersectoral exchange of information remains largely hindered due to differences in data structure, content, and adherence to data protection regulations. In response to this challenge, the Medical Informatics Initiative (MII) was launched in Germany, focusing initially on university hospitals to foster the exchange and utilization of real-world data through the development of standardized methods and tools, including the creation of a common core dataset. Our aim, as part of the Medical Informatics Research Hub in Saxony (MiHUBx), is to extend the MII concepts to non-university healthcare providers in a more seamless manner to enable the exchange of real-world data among intersectoral medical sites. Methods: We investigated what services are needed to facilitate the provision of harmonized real-world data for cross-site research. On this basis, we designed a Service Platform Prototype that hosts services for data harmonization, adhering to the globally recognized Health Level 7 (HL7) Fast Healthcare Interoperability Resources (FHIR) international standard communication format and the Observational Medical Outcomes Partnership (OMOP) common data model (CDM). Leveraging these standards, we implemented additional services facilitating data utilization, exchange and analysis. Throughout the development phase, we collaborated with an interdisciplinary team of experts from the fields of system administration, software engineering and technology acceptance to ensure that the solution is sustainable and reusable in the long term. Results: We have developed the pre-built packages "ResearchData-to-FHIR," "FHIR-to-OMOP," and "Addons," which provide the services for data harmonization and provision of project-related real-world data in both the FHIR MII Core dataset format (CDS) and the OMOP CDM format as well as utilization and a Service Platform Prototype to streamline data management and use. Conclusion: Our development shows a possible approach to extend the MII concepts to non-university healthcare providers to enable cross-site research on real-world data. Our Service Platform Prototype can thus pave the way for intersectoral data sharing, federated analysis, and provision of SMART-on-FHIR applications to support clinical decision making.
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In this study, two different types of amorphous carbonaceous Precambrian rock, classified as noble elite shungite and black raw shungite, were tested as possible electrode materials of natural origin. Both types were machined into cylindrical shapes to form the corresponding solid electrodes and their physicochemical and electrochemical properties were compared with the standard glassy carbon electrode (GCE). The raw stones were first subjected to microscopic imaging by using scanning electron microscopy and energy-dispersive X-ray spectroscopy, both of which indicated significant differences in their morphology and in the content of impurities. An electrode prototype manufactured from noble elite shungite (EShE) with a carbon content of about 94% (w/w) has offered a very satisfactory electrochemical performance with a nearly identical heterogeneous electron-transfer rate constant of 7.8 × 10-3 cm s-1 for ferro/ferricyanide redox couple, a slightly narrower potential range (~2.1 V) and a relatively low double-layer capacitance (of ca. 50 µF), resulting in low background currents comparable to those at the GCE. In contrast, the second electrode based on black raw shungite (BShE) with a carbon content of ca. 63% (w/w) exhibited markedly worse electrochemical properties and more than four times higher double-layer capacitance, both of which were probably due to the presence of poorly conductive impurities. The whole study has been completed with three different examples of electroanalytical applications, revealing that the first type, EShE, is a more suitable material for the preparation of electrodes and may represent a cheap alternative to commercially marketed products.
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Purpose: Osteoporosis is a severe health problem with social and economic impacts on society. The standard treatment consists of the systemic administration of drugs such as bisphosphonates, with alendronate (ALN) being one of the most common. Nevertheless, complications of systemic administration occur with this drug. Therefore, it is necessary to develop new strategies, such as local administration. Methods: In this study, emulsion/dispersion scaffolds based on W/O emulsion of PCL and PF68 with ALN, containing hydroxyapatite (HA) nanoparticles as the dispersion phase were prepared using electrospinning. Scaffolds with different release kinetics were tested in vitro on the co-cultures of osteoblasts and osteoclast-like cells, isolated from adult osteoporotic and control rats. Cell viability, proliferation, ALP, TRAP and CA II activity were examined. A scaffold with a gradual release of ALN was tested in vivo in the bone defects of osteoporotic and control rats. Results: The release kinetics were dependent on the scaffold composition and the used system of the poloxamers. The ALN was released from the scaffolds for more than 22 days. The behavior of cells cultured in vitro on scaffolds with different release kinetics was comparable. The difference was evident between cell co-cultures isolated from osteoporotic and control animals. The PCL/HA scaffold show slow degradation in vivo and residual scaffold limited new bone formation inside the defects. Nevertheless, the released ALN supported bone formation in the areas surrounding the residual scaffold. Interestingly, a positive effect of systemic administration of ALN was not proved. Conclusion: The prepared scaffolds enabled tunable control release of ALN. The effect of ALN was proved in vitro and in in vivo study supported peri-implant bone formation.
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Alendronato , Conservadores da Densidade Óssea , Ratos , Animais , Alendronato/farmacologia , Emulsões/farmacologia , Osteogênese , Osteoclastos , Osteoblastos , Durapatita/farmacologia , Conservadores da Densidade Óssea/farmacologiaRESUMO
The present study focused on the more detailed characterization of chitosan-carrageenan-based matrix tablets with respect to their potential utilization for drug targeting in the intestine. The study systematically dealt with the particular stages of the dissolution process, as well as with different views of the physico-chemical processes involved in these stages. The initial swelling of the tablets in the acidic medium based on the combined microscopy-calorimetry point of view, the pH-induced differences in the erosion and swelling of the tested tablets, and the morphological characterization of the tablets are discussed. The dissolution kinetics correlated with the rheological properties and mucoadhesive behavior of the tablets are also reported, and, correspondingly, the formulations with suitable properties were identified. It was confirmed that the formation of the chitosan-carrageenan polyelectrolyte complex may be an elegant and beneficial alternative solution for the drug targeting to the intestine by the matrix tablet.
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The group Anguimorpha represents one of the most unified squamate clades in terms of body plan, ecomorphology, ecophysiology and evolution. On the other hand, the anguimorphs vary between different habitats and ecological niches. Therefore, we focused on the group Anguimorpha to test a possible correlation between heart morphology and ecological niche with respect to phylogenetic position in Squamata with Sphenodon, Salvator, and Pogona as the outgroups. The chosen lepidosaurian species were investigated by microCT. Generally, all lepidosaurs had two well-developed atria with complete interatrial septum and one ventricle divided by ventricular septa to three different areas. The ventricles of all lepidosaurians had a compact layer and abundant trabeculae. The compact layer and trabeculae were developed in accordance with particular ecological niche of the species, the trabeculae in nocturnal animals with low metabolism, such as Sphenodon, Heloderma or Lanthanotus were more massive. On the other hand athletic animals, such as varanids or Salvator, had ventricle compartmentalization divided by three incomplete septa. A difference between varanids and Salvator was found in compact layer thickness: thicker in monitor lizards and possibly linked to their mammalian-like high blood pressure, and the level of ventricular septation. In summary: heart morphology varied among clades in connection with the ecological niche of particular species and it reflects the phylogenetic position in model clade Anguimorpha. In the absence of fossil evidence, this is the closest approach how to understand heart evolution and septation in clade with different cardiac compartmentalization levels.
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Complex assessment of gradual changes in scaffold morphology and stiffness is an essential step in bone filler development. Current approach, however, does not reflect long term cell proliferation effect as the mechanical tests are usually conducted on pristine materials without cells or cell influence on material stiffness is evaluated after one time period only. Here, biocompatible silk fibroin (SF) porous scaffolds envisioned for bone defect filling were prepared by dissolving of fibroin fibers, followed by dialysis, freeze-drying and final stabilization. Particular attention was devoted to the influence of bone cell proliferation up to 2 months on the stiffness of the material. The morphology of the material was studied in terms of its inner structure and the overall changes in the surface characteristics due to proliferation of MG 63 bone cell line. The SF scaffold stiffness significantly increased during first month followed by its decline during second month due to bone cell seeding. After 2 months, the SF scaffold was completely colonized, which resulted in a gradual decay of its structure. The length of degradation due to bone cell proliferation and mechanical behavior corresponded to the requirements set for reasonable filler material indicating that porous SF scaffolds comprise a promising biomaterial for bone regeneration.
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Background: Retrospective research on real-world data provides the ability to gain evidence on specific topics especially when running across different sites in research networks. Those research networks have become increasingly relevant in recent years; not least due to the special situation caused by the COVID-19 pandemic. An important requirement for those networks is the data harmonization by ensuring the semantic interoperability. Aims: In this paper we demonstrate (1) how to facilitate digital infrastructures to run a retrospective study in a research network spread across university and non-university hospital sites; and (2) to answer a medical question on COVID-19 related change in diagnostic counts for diabetes-related eye diseases. Materials and methods: The study is retrospective and non-interventional and runs on medical case data documented in routine care at the participating sites. The technical infrastructure consists of the OMOP CDM and other OHDSI tools that is provided in a transferable format. An ETL process to transfer and harmonize the data to the OMOP CDM has been utilized. Cohort definitions for each year in observation have been created centrally and applied locally against medical case data of all participating sites and analyzed with descriptive statistics. Results: The analyses showed an expectable drop of the total number of diagnoses and the diagnoses for diabetes in general; whereas the number of diagnoses for diabetes-related eye diseases surprisingly decreased stronger compared to non-eye diseases. Differences in relative changes of diagnoses counts between sites show an urgent need to process multi-centric studies rather than single-site studies to reduce bias in the data. Conclusions: This study has demonstrated the ability to utilize an existing portable and standardized infrastructure and ETL process from a university hospital setting and transfer it to non-university sites. From a medical perspective further activity is needed to evaluate data quality of the utilized real-world data documented in routine care and to investigate its eligibility of this data for research.
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COVID-19 , Diabetes Mellitus , Oftalmopatias , COVID-19/diagnóstico , Bases de Dados Factuais , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/terapia , Gerenciamento Clínico , Oftalmopatias/diagnóstico , Oftalmopatias/terapia , Humanos , Pandemias , Estudos RetrospectivosRESUMO
Considerable amount of research has been focused on dentin mineralization, odontoblast differentiation, and their application in dental tissue engineering. However, very little is known about the differential role of functionally and spatially distinct types of dental epithelium during odontoblast development. Here we show morphological and functional differences in dentin located in the crown and roots of mouse molar and analogous parts of continuously growing incisors. Using a reporter (DSPP-cerulean/DMP1-cherry) mouse strain and mice with ectopic enamel (Spry2+/- ;Spry4-/- ), we show that the different microstructure of dentin is initiated in the very beginning of dentin matrix production and is maintained throughout the whole duration of dentin growth. This phenomenon is regulated by the different inductive role of the adjacent epithelium. Thus, based on the type of interacting epithelium, we introduce more generalized terms for two distinct types of dentins: cementum versus enamel-facing dentin. In the odontoblasts, which produce enamel-facing dentin, we identified uniquely expressed genes (Dkk1, Wisp1, and Sall1) that were either absent or downregulated in odontoblasts, which form cementum-facing dentin. This suggests the potential role of Wnt signalling on the dentin structure patterning. Finally, we show the distribution of calcium and magnesium composition in the two developmentally different types of dentins by utilizing spatial element composition analysis (LIBS). Therefore, variations in dentin inner structure and element composition are the outcome of different developmental history initiated from the very beginning of tooth development. Taken together, our results elucidate the different effects of dental epithelium, during crown and root formation on adjacent odontoblasts and the possible role of Wnt signalling which together results in formation of dentin of different quality. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).