Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 34.505
Filtrar
Más filtros











Intervalo de año de publicación
1.
Int J Mol Sci ; 25(13)2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-39000517

RESUMEN

Advancing age is associated with several age-related diseases (ARDs), with musculoskeletal conditions impacting millions of elderly people worldwide. With orthopedic conditions contributing towards considerable number of patients, a deeper understanding of bone aging is the need of the hour. One of the underlying factors of bone aging is cellular senescence and its associated senescence associated secretory phenotype (SASP). SASP comprises of pro-inflammatory markers, cytokines and chemokines that arrest cell growth and development. The accumulation of SASP over several years leads to chronic low-grade inflammation with advancing age, also known as inflammaging. The pathways and molecular mechanisms focused on bone senescence and inflammaging are currently limited but are increasingly being explored. Most of the genes, pathways and mechanisms involved in senescence and inflammaging coincide with those associated with cancer and other ARDs like osteoarthritis (OA). Thus, exploring these pathways using techniques like sequencing, identifying these factors and combatting them with the most suitable approach are crucial for healthy aging and the early detection of ARDs. Several approaches can be used to aid regeneration and reduce senescence in the bone. These may be pharmacological, non-pharmacological and lifestyle interventions. With increasing evidence towards the intricate relationship between aging, senescence, inflammation and ARDs, these approaches may also be used as anti-aging strategies for the aging bone marrow (BM).


Asunto(s)
Envejecimiento , Huesos , Senescencia Celular , Inflamación , Humanos , Senescencia Celular/genética , Inflamación/genética , Inflamación/metabolismo , Envejecimiento/genética , Huesos/metabolismo , Huesos/patología , Animales , Fenotipo Secretor Asociado a la Senescencia/genética , Transducción de Señal
2.
Int J Med Sci ; 21(9): 1672-1680, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39006845

RESUMEN

Implants have always been within the interest of both clinicians and material scientists due to their places in reconstructive and prosthetics surgery. Excessive bone loss or resorption in some patients makes it difficult to design and manufacture the implants that bear the necessary loads to carry the final prosthetics. With this study; we tried to determine the minimum material thickness of the subperiosteal implants that can withstand the physiological forces. We have created a digital average bone structure based on actual patient data and designed different subperiosteal implants with 1, 1.5, and 2mm material thicknesses (M1, M2, M3) for this digital model. The designed implant models are subjected to 250 Newtons (N) of force, and the implant and bone are tested for the stress they are exposed to, the pressure they transmit to, and their mechanical strength with Finite Element Analysis with the physical parameters boot for the implant material and human bone. Results show us that under specific design parameters and thicknesses, the 1mm thickness design failed due to exceeding the yield stress limit of 415MPa with a 495,44MPa value. The thinnest implant showed plastic deformation and transmitted excessive forces, which may cause bone resorption due to residual stress. We determined that thinner subperiosteal implants down to 1.5mm that have the necessary material parameters for function and tissue support can be designed and manufactured with current technologies.


Asunto(s)
Análisis de Elementos Finitos , Estrés Mecánico , Humanos , Prótesis e Implantes , Fenómenos Biomecánicos , Huesos/cirugía , Huesos/fisiología , Ensayo de Materiales
3.
Tissue Cell ; 89: 102422, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39003912

RESUMEN

Tumour necrosis factor alpha (TNF-α) is a pleiotropic cytokine synthesised primarily by mononuclear cells; it has a potent pro-inflammatory effect, playing a crucial role in metabolic, immune, and inflammatory diseases. This cytokine has been studied in various biological systems. In bone tissue, TNF-α plays an integral role in skeletal disorders such as osteoporosis, fracture repair and rheumatoid arthritis through its involvement in regulating the balance between osteoblasts and osteoclasts, mediating inflammatory responses, promoting angiogenesis and exacerbating synovial proliferation. The biological effect TNF-α exerts in this context is determined by a combination of the signalling pathway it activates, the type of receptor it binds, and the concentration and duration of exposure. This review summarises the participation and pathophysiological role of TNF-α in osteoporosis, bone damage repair, chronic immunoinflammatory bone disease and spinal cord injury, and discusses its main mechanisms.


Asunto(s)
Osteoporosis , Factor de Necrosis Tumoral alfa , Humanos , Osteoporosis/metabolismo , Osteoporosis/patología , Factor de Necrosis Tumoral alfa/metabolismo , Animales , Inflamación/metabolismo , Inflamación/patología , Osteoblastos/metabolismo , Enfermedades Óseas/metabolismo , Enfermedades Óseas/patología , Huesos/metabolismo , Huesos/patología , Transducción de Señal
4.
Int J Mol Sci ; 25(14)2024 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-39063052

RESUMEN

Nowadays, as a result of the frequent occurrence of accidental injuries and traumas such as bone damage, the number of people causing bone injuries or fractures is increasing around the world. The design and fabrication of ideal bone tissue engineering (BTE) materials have become a research hotspot in the scientific community, and thus provide a novel path for the treatment of bone diseases. Among the materials used to construct scaffolds in BTE, including metals, bioceramics, bioglasses, biomacromolecules, synthetic organic polymers, etc., natural biopolymers have more advantages against them because they can interact with cells well, causing natural polymers to be widely studied and applied in the field of BTE. In particular, alginate has the advantages of excellent biocompatibility, good biodegradability, non-immunogenicity, non-toxicity, wide sources, low price, and easy gelation, enabling itself to be widely used as a biomaterial. However, pure alginate hydrogel as a BTE scaffold material still has many shortcomings, such as insufficient mechanical properties, easy disintegration of materials in physiological environments, and lack of cell-specific recognition sites, which severely limits its clinical application in BTE. In order to overcome the defects of single alginate hydrogels, researchers prepared alginate composite hydrogels by adding one or more materials to the alginate matrix in a certain proportion to improve their bioapplicability. For this reason, this review will introduce in detail the methods for constructing alginate composite hydrogels, including alginate/polymer composite hydrogels, alginate/bioprotein or polypeptide composite hydrogels, alginate/bioceramic composite hydrogels, alginate/bioceramic composite hydrogels, and alginate/nanoclay composite hydrogels, as well as their biological application trends in BTE scaffold materials, and look forward to their future research direction. These alginate composite hydrogel scaffolds exhibit both unexceptionable mechanical and biochemical properties, which exhibit their high application value in bone tissue repair and regeneration, thus providing a theoretical basis for the development and sustainable application of alginate-based functional biomedical materials.


Asunto(s)
Alginatos , Materiales Biocompatibles , Huesos , Hidrogeles , Ingeniería de Tejidos , Andamios del Tejido , Alginatos/química , Ingeniería de Tejidos/métodos , Hidrogeles/química , Humanos , Andamios del Tejido/química , Materiales Biocompatibles/química , Animales , Regeneración Ósea/efectos de los fármacos
5.
Mol Biol Rep ; 51(1): 838, 2024 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-39042226

RESUMEN

BACKGROUND: Bioglass materials have gained significant attention in the field of tissue engineering due to their osteoinductive and biocompatible properties that promote bone cell differentiation. In this study, a novel composite scaffold was developed using a sol-gel technique to combine bioglass (BG) 58 S with a poly L-lactic acid (PLLA). METHODS AND RESULTS: The physiochemical properties, morphology, and osteoinductive potential of the scaffolds were investigated by X-ray diffraction analysis, scanning electron microscopy, and Fourier-transform infrared spectroscopy. The results showed that the SiO2-CaO-P2O5 system was successfully synthesized by the sol-gel method. The PLLA scaffolds containing BG was found to be osteoinductive and promoted mineralization, as demonstrated by calcium deposition assay, upregulation of alkaline phosphatase enzyme activity, and Alizarin red staining data. CONCLUSIONS: These in vitro studies suggest that composite scaffolds incorporating hBMSCs are a promising substitute material to be implemented in bone tissue engineering. The PLLA/BG scaffolds promote osteogenesis and support the differentiation of bone cells, such as osteoblasts, due to their osteoinductive properties.


Asunto(s)
Materiales Biocompatibles , Diferenciación Celular , Cerámica , Osteogénesis , Poliésteres , Ingeniería de Tejidos , Andamios del Tejido , Poliésteres/química , Andamios del Tejido/química , Cerámica/química , Cerámica/farmacología , Ingeniería de Tejidos/métodos , Materiales Biocompatibles/farmacología , Materiales Biocompatibles/química , Osteogénesis/efectos de los fármacos , Humanos , Diferenciación Celular/efectos de los fármacos , Regeneración Ósea/efectos de los fármacos , Osteoblastos/efectos de los fármacos , Osteoblastos/metabolismo , Espectroscopía Infrarroja por Transformada de Fourier , Células Madre Mesenquimatosas/efectos de los fármacos , Células Madre Mesenquimatosas/metabolismo , Difracción de Rayos X , Huesos/efectos de los fármacos , Huesos/metabolismo , Fosfatasa Alcalina/metabolismo , Microscopía Electrónica de Rastreo
6.
Biomed Mater ; 19(5)2024 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-38986475

RESUMEN

Bioactive and biodegradable scaffolds that mimic the natural extracellular matrix of bone serve as temporary structures to guide new bone tissue growth. In this study, 3D-printed scaffolds composed of poly (lactic acid) (PLA)-tricalcium phosphate (TCP) (90-10 wt.%) were modified with 1%, 5%, and 10 wt.% of ZnO to enhance bone tissue regeneration. A commercial chain extender named Joncryl was incorporated alongside ZnO to ensure the printability of the composites. Filaments were manufactured using a twin-screw extruder and subsequently used to print 3D scaffolds via fused filament fabrication (FFF). The scaffolds exhibited a homogeneous distribution of ZnO and TCP particles, a reproducible structure with 300 µm pores, and mechanical properties suitable for bone tissue engineering, with an elastic modulus around 100 MPa. The addition of ZnO resulted in enhanced surface roughness on the scaffolds, particularly for ZnO microparticles, achieving values up to 241 nm. This rougher topography was responsible for enhancing protein adsorption on the scaffolds, with an increase of up to 85% compared to the PLA-TCP matrix. Biological analyses demonstrated that the presence of ZnO promotes mesenchymal stem cell (MSC) proliferation and differentiation into osteoblasts. Alkaline phosphatase (ALP) activity, an important indicator of early osteogenic differentiation, increased up to 29%. The PLA-TCP composite containing 5% ZnO microparticles exhibited an optimized degradation rate and enhanced bioactivity, indicating its promising potential for bone repair applications.


Asunto(s)
Materiales Biocompatibles , Regeneración Ósea , Fosfatos de Calcio , Diferenciación Celular , Proliferación Celular , Células Madre Mesenquimatosas , Osteoblastos , Poliésteres , Impresión Tridimensional , Ingeniería de Tejidos , Andamios del Tejido , Óxido de Zinc , Andamios del Tejido/química , Fosfatos de Calcio/química , Poliésteres/química , Regeneración Ósea/efectos de los fármacos , Ingeniería de Tejidos/métodos , Células Madre Mesenquimatosas/citología , Óxido de Zinc/química , Materiales Biocompatibles/química , Diferenciación Celular/efectos de los fármacos , Osteoblastos/citología , Osteogénesis/efectos de los fármacos , Ensayo de Materiales , Huesos , Regeneración Tisular Dirigida/métodos , Humanos , Animales , Fosfatasa Alcalina/metabolismo , Módulo de Elasticidad , Porosidad , Propiedades de Superficie
7.
Commun Biol ; 7(1): 892, 2024 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-39039245

RESUMEN

Bone is a highly dynamic tissue undergoing continuous formation and resorption. Here, we investigated differential but complementary roles of hypoxia-inducible factor (HIF)-1α and HIF-2α in regulating bone remodeling. Using RNA-seq analysis, we identified that specific genes involved in regulating osteoblast differentiation were similarly but slightly differently governed by HIF-1α and HIF-2α. We found that increased HIF-1α expression inhibited osteoblast differentiation via inhibiting RUNX2 function by upregulation of Twist2, confirmed using Hif1a conditional knockout (KO) mouse. Ectopic expression of HIF-1α via adenovirus transduction resulted in the increased expression and activity of RANKL, while knockdown of Hif1a expression via siRNA or osteoblast-specific depletion of Hif1a in conditional KO mice had no discernible effect on osteoblast-mediated osteoclast activation. The unexpected outcome was elucidated by the upregulation of HIF-2α upon Hif1a overexpression, providing evidence that Hif2a is a transcriptional target of HIF-1α in regulating RANKL expression, verified through an experiment of HIF-2α knockdown after HIF-1α overexpression. The above results were validated in an ovariectomized- and aging-induced osteoporosis model using Hif1a conditional KO mice. Our findings conclude that HIF-1α plays an important role in regulating bone homeostasis by controlling osteoblast differentiation, and in influencing osteoclast formation through the regulation of RANKL secretion via HIF-2α modulation.


Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico , Homeostasis , Subunidad alfa del Factor 1 Inducible por Hipoxia , Ratones Noqueados , Osteoblastos , Animales , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Ratones , Osteoblastos/metabolismo , Femenino , Huesos/metabolismo , Diferenciación Celular , Osteoclastos/metabolismo , Osteogénesis/genética , Ratones Endogámicos C57BL , Osteoporosis/genética , Osteoporosis/metabolismo
8.
Ann Afr Med ; 23(2): 149-153, 2024 Apr 01.
Artículo en Francés, Inglés | MEDLINE | ID: mdl-39028162

RESUMEN

CONTEXT: A major indication for referrals for bone scans (BS) to establish or exclude skeletal metastases. Few patients are referred with clinically indeterminate diagnosis or cancer of unknown primary (CUP), to search for bony metastases or primary tumor. AIMS: This study aimed to assess the usefulness or otherwise for BS in such instances. SETTINGS AND DESIGN: A retrospective cross-sectional study of BS performed for CUP and indeterminate diagnosis from 2012 to 2016 in the nuclear medicine unit of a tertiary teaching hospital. SUBJECTS AND METHODS: The study involved reviews of technetium-99m diphosphonate BS for patients with CUP. BSs were reported by nuclear physicians as normal, normal variants, suspicious for metastases or as malignant, and with solitary or multiple skeletal metastases. STATISTICAL ANALYSIS USED: Data were analyzed using SPSS version 21 for descriptive analysis. Continuous data were displayed as means along with their standard deviation; categorical data were tabulated as frequencies and percentages. RESULTS: Of 2156 BS, 42 (0.02%) were eligible. Patients were aged 27-86 years, mainly in the sixth and seventh decades of life. Bone metastases were identified in 14 (33%) of these patients, whereas 17 BS (40%) were normal, BS appeared equivocal in 10 (23.8%). CONCLUSIONS: Single-photon emission computed tomography/computed tomography availability would resolve the clinical dilemma in patients with equivocal and apparently normal BS.


Résumé Contexte:Une indication majeure pour les références à des scintigraphies osseuses (BS) pour établir ou exclure des métastases squelettiques. Peu de patients sont référés avec diagnostic cliniquement indéterminé ou cancer primitif inconnu (CUP), pour rechercher des métastases osseuses ou une tumeur primitive.Objectifs:Cette étude visait à évaluer l'utilité ou non de la BS dans de tels cas.Paramètres et conception:Une étude transversale rétrospective sur le BS réalisée pour CUP et diagnostic indéterminé de 2012 à 2016 dans l'unité de médecine nucléaire d'un hôpital universitaire tertiaire.Sujets et Méthodes:L'étude comprenait des examens du diphosphonate de technétium-99m BS pour les patients atteints de CUP. Des BS ont été signalés par des médecins nucléaires comme normales, variantes normales, suspectes de métastases ou malignes, et avec métastases squelettiques solitaires ou multiples.Analyses statistiques utilisé:Les données ont été analysées à l'aide de SPSS version 21 pour une analyse descriptive. Les données continues ont été affichées comme moyennes avec leur l'ecarts t; les données catégorielles ont été présentées sous forme de fréquences et de pourcentages.Résultats:Sur 2156 BS, 42 (0,02%) étaient éligibles. Les patients étaient âgés 27 à 86 ans, principalement dans les sixième et septième décennies de la vie. Des métastases osseuses ont été identifiées chez 14 (33 %) de ces patients, alors que 17 BS (40 %) étaient normaux, la BS semblait équivoque dans 10 cas (23,8 %).Conclusions:Tomodensitométrie par émission de photons uniques/tomodensitométrie la disponibilité résoudrait le dilemme clinique chez les patients atteints de BS équivoque et apparemment normale.


Asunto(s)
Neoplasias Óseas , Humanos , Femenino , Masculino , Neoplasias Óseas/secundario , Neoplasias Óseas/diagnóstico por imagen , Persona de Mediana Edad , Estudios Transversales , Estudios Retrospectivos , Anciano , Adulto , Anciano de 80 o más Años , Neoplasias Primarias Desconocidas/diagnóstico por imagen , Neoplasias Primarias Desconocidas/patología , Cintigrafía , Radiofármacos , Huesos/diagnóstico por imagen , Huesos/patología , Medronato de Tecnecio Tc 99m
9.
Int Immunopharmacol ; 138: 112573, 2024 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-38971108

RESUMEN

BACKGROUND: Tianhe Zhuifeng Gao (TZG) is an authorized Chinese patent drug with satisfying clinical efficacy, especially for RA patients with cold-dampness syndrome. However, its underlying pharmacological mechanisms remain unclear. METHOD: Anti-arthritic effects of TZG were evaluated using an adjuvant-induced arthritis (AIA) rat model. Transcriptional regulatory network analysis based on synovial tissues obtained from AIA rats, combining with our previous analysis based on whole blood samples from RA patients with cold-dampness syndrome and co-immunoprecipitation were performed to identify involved dominant pathways, which were experimentally verified using AIA-wind-cold-dampness stimulation modified (AIA-M) animal model. RESULTS: TZG treatment dramatically attenuated joint injury and inflammatory response in AIA rats, and PSMC2-RUNX2-COL1A1 axis, which was closely associated with bone/cartilage damage, was inferred to be one of therapeutic targets of TZG against RA. Experimentally, TZG displayed obvious pharmacological effects for alleviating the joint inflammation and destruction through reinstating the body weight, reducing the arthritis score, the limbs diameters, the levels of RF and CRP, and the inflammatory cytokines, recovering the thymus and spleen indexes, diminishing bone and cartilage destruction, as well elevating the pain thresholds of AIA-M rats. In addition, TZG markedly reversed the abnormal energy metabolism in AIA-M rats through enhancing articular temperature, daily water consumption, and regulating expression levels of energy metabolism parameters and hormones. Moreover, TZG also significantly modulated the abnormal expression levels of PSMC2, RUNX2 and COL1A1 proteins in the ankle tissues of AIA-M rats. CONCLUSION: TZG may exert the bone protective effects in RA therapy via regulating bone and cartilage damage-associated PSMC2-RUNX2-COL1A1 axis.


Asunto(s)
Artritis Experimental , Artritis Reumatoide , Cadena alfa 1 del Colágeno Tipo I , Colágeno Tipo I , Medicamentos Herbarios Chinos , Animales , Artritis Reumatoide/tratamiento farmacológico , Artritis Experimental/tratamiento farmacológico , Ratas , Humanos , Masculino , Medicamentos Herbarios Chinos/uso terapéutico , Medicamentos Herbarios Chinos/farmacología , Colágeno Tipo I/metabolismo , Colágeno Tipo I/genética , Redes Reguladoras de Genes/efectos de los fármacos , Subunidad alfa 1 del Factor de Unión al Sitio Principal/genética , Subunidad alfa 1 del Factor de Unión al Sitio Principal/metabolismo , Cartílago/metabolismo , Cartílago/patología , Cartílago/efectos de los fármacos , Huesos/efectos de los fármacos , Huesos/metabolismo , Huesos/patología , Antiinflamatorios/uso terapéutico , Antiinflamatorios/farmacología , Transducción de Señal/efectos de los fármacos
10.
Proc Biol Sci ; 291(2026): 20232915, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38981519

RESUMEN

Archaeological studies of pre-historic Arctic cultures are often limited to artefacts and architecture; such records may be incomplete and often do not provide a continuous record of past occupation. Here, we used lake sediment archives to supplement archaeological evidence to explore the history of Thule and Dorset populations on Somerset Island, Nunavut (Canada). We examined biomarkers in dated sediment cores from two ponds adjacent to abandoned Thule settlements (PaJs-3 and PaJs-13) and compared these to sediment cores from two ponds without past human occupation. Coprostanol and epicoprostanol, δ15N measurements, sedimentary chlorophyll a and the ratio of diatom valves to chrysophyte cysts were elevated in the dated sediment profiles at both sites during Thule and Dorset occupations. Periods of pronounced human impact during the Thule occupation of the site were corroborated by 14C-dated caribou bones found at both sites that identified intense caribou hunting between ca 1185 and 1510 CE. Notably, these sediment core data show evidence of the Dorset occupation from ca 200 to 500 CE at sites where archaeological evidence was heretofore lacking. We highlight the utility of lake sediments in assisting archaeological studies to better establish the timings, peak occupations and even lifestyle practices of the Dorset and Thule Arctic peoples.


Asunto(s)
Arqueología , Biomarcadores , Huesos , Sedimentos Geológicos , Sedimentos Geológicos/química , Sedimentos Geológicos/análisis , Regiones Árticas , Huesos/química , Animales , Humanos , Biomarcadores/análisis , Nunavut , Reno , Lagos/química
11.
Sci Rep ; 14(1): 16576, 2024 07 17.
Artículo en Inglés | MEDLINE | ID: mdl-39019937

RESUMEN

Bone segmentation is an important step to perform biomechanical failure load simulations on in-vivo CT data of patients with bone metastasis, as it is a mandatory operation to obtain meshes needed for numerical simulations. Segmentation can be a tedious and time consuming task when done manually, and expert segmentations are subject to intra- and inter-operator variability. Deep learning methods are increasingly employed to automatically carry out image segmentation tasks. These networks usually need to be trained on a large image dataset along with the manual segmentations to maximize generalization to new images, but it is not always possible to have access to a multitude of CT-scans with the associated ground truth. It then becomes necessary to use training techniques to make the best use of the limited available data. In this paper, we propose a dedicated pipeline of preprocessing, deep learning based segmentation method and post-processing for in-vivo human femurs and vertebrae segmentation from CT-scans volumes. We experimented with three U-Net architectures and showed that out-of-the-box models enable automatic and high-quality volume segmentation if carefully trained. We compared the failure load simulation results obtained on femurs and vertebrae using either automatic or manual segmentations and studied the sensitivity of the simulations on small variations of the automatic segmentation. The failure loads obtained using automatic segmentations were comparable to those obtained using manual expert segmentations for all the femurs and vertebrae tested, demonstrating the effectiveness of the automated segmentation approach for failure load simulations.


Asunto(s)
Aprendizaje Profundo , Análisis de Elementos Finitos , Tomografía Computarizada por Rayos X , Humanos , Tomografía Computarizada por Rayos X/métodos , Fémur/diagnóstico por imagen , Procesamiento de Imagen Asistido por Computador/métodos , Huesos/diagnóstico por imagen , Simulación por Computador , Fenómenos Biomecánicos , Columna Vertebral/diagnóstico por imagen
12.
Sci Rep ; 14(1): 17440, 2024 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-39075135

RESUMEN

Few reports have documented how the accuracy of stopping power ratio (SPR) prediction for porous bone tissue affects the dose distribution of scanned carbon-ion beam therapy. The estimated SPR based on single-energy computed tomography (SECT) and dual-energy CT (DECT) were compared for the femur of a Rando phantom which simulates the porosity of human bone, NEOBONE which is the hydroxyapatite synthetic bone substitute, and soft tissue samples. Dose differences between SECT and DECT were evaluated for a scanned carbon-ion therapy treatment plan for the Rando phantom. The difference in the water equivalent length was measured to extract the SPR of the examined samples. The differences for SPR estimated from the DECT-SPR conversion were small with - 1.8% and - 3.3% for the Rando phantom femur and NEOBONE, respectively, whereas the differences for SECT-SPR were between 7.6 and 70.7%, illustrating a 1.5-mm shift of the range and a dose difference of 13.3% at maximum point in the evaluation of the dose distribution. This study demonstrated that the DECT-SPR conversion method better estimated the SPR of the porosity of bone tissues than SECT-SPR followed by the accurate range of the carbon-ion beams on carbon-ion dose calculations.


Asunto(s)
Fantasmas de Imagen , Planificación de la Radioterapia Asistida por Computador , Tomografía Computarizada por Rayos X , Humanos , Porosidad , Tomografía Computarizada por Rayos X/métodos , Planificación de la Radioterapia Asistida por Computador/métodos , Fémur/diagnóstico por imagen , Radioterapia de Iones Pesados/métodos , Dosificación Radioterapéutica , Radiometría/métodos , Huesos/diagnóstico por imagen , Huesos/efectos de la radiación , Carbono/química
13.
Bone Res ; 12(1): 38, 2024 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-38961077

RESUMEN

Bone marrow adipocytes (BMAds) affect bone homeostasis, but the mechanism remains unclear. Here, we showed that exercise inhibited PCNA clamp-associated factor (PCLAF) secretion from the bone marrow macrophages to inhibit BMAds senescence and thus alleviated skeletal aging. The genetic deletion of PCLAF in macrophages inhibited BMAds senescence and delayed skeletal aging. In contrast, the transplantation of PCLAF-mediated senescent BMAds into the bone marrow of healthy mice suppressed bone turnover. Mechanistically, PCLAF bound to the ADGRL2 receptor to inhibit AKT/mTOR signaling that triggered BMAds senescence and subsequently spread senescence among osteogenic and osteoclastic cells. Of note, we developed a PCLAF-neutralizing antibody and showed its therapeutic effects on skeletal health in old mice. Together, these findings identify PCLAF as an inducer of BMAds senescence and provide a promising way to treat age-related osteoporosis.


Asunto(s)
Adipocitos , Envejecimiento , Senescencia Celular , Animales , Adipocitos/metabolismo , Senescencia Celular/fisiología , Ratones , Envejecimiento/fisiología , Ratones Endogámicos C57BL , Células de la Médula Ósea/metabolismo , Huesos/metabolismo , Huesos/fisiología , Masculino , Osteogénesis/fisiología , Transducción de Señal , Macrófagos/metabolismo
14.
Clin Interv Aging ; 19: 1259-1272, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39011312

RESUMEN

Postmenopausal osteoporosis (PMOP) is a major health problem affecting millions of women worldwide. PMOP patients are often accompanied by abnormal accumulation of bone marrow adipose tissue (BMAT). BMAT is a critical regulator of bone homeostasis, and an increasing BMAT volume is negatively associated with bone mass reduction or fracture. BMAT regulates bone metabolism via adipokines, cytokines and the immune system, but the specific mechanisms are largely unknown. This review emphasizes the impact of estrogen deficiency on bone homeostasis and BMAT expansion, and the mechanism by which BMAT regulates PMOP, providing a promising strategy for targeting BMAT in preventing and treating PMOP.


Asunto(s)
Tejido Adiposo , Médula Ósea , Osteoporosis Posmenopáusica , Humanos , Tejido Adiposo/metabolismo , Femenino , Densidad Ósea , Adipoquinas/metabolismo , Estrógenos/metabolismo , Huesos/metabolismo , Animales , Citocinas/metabolismo , Homeostasis
15.
Stomatologiia (Mosk) ; 103(3): 5-10, 2024.
Artículo en Ruso | MEDLINE | ID: mdl-38904552

RESUMEN

THE AIM OF THE STUDY: Was to determine the presence of an amoxicillin-based antibiotic in bone implant biopsies by Raman spectroscopy in an experiment. MATERIALS AND METHODS: Experimental animals (n=10, a miniature pig of the Svetlogorsk breed) were divided into 2 groups of 5 animals. Groups 1 and 2 were injected with amoxicillin 2 ml per 20 kg of body weight 30 minutes before dental implantation surgery, then group 2 was additionally injected with 1 ml per 20 kg of body weight for 5 days. Each animal has 6 implants installed. On the 1st, 3rd, 7th, 14th day, an implant-bone biopsy was removed from each animal, micro-preparations were made and Raman spectroscopy was performed to assess the peak matching of the Raman spectrum. RESULTS: In animals of the 1st and 2nd groups, the main peak of the Raman spectrum, which is closest to the values of the antibiotic spectrum of interest to us, is located closer to 1448 cm-1 and 1446 cm-1, respectively. At the same time, in both observations, the peaks relate to the spectrum of bone tissue, which cannot indicate the content of an antibiotic in the drug. CONCLUSION: No scattering spectra corresponding to the antibiotic molecule were found in any animal from both groups, regardless of the mode of administration and dosage of amoxicillin. The detected peaks corresponded to bone tissue without an antibiotic.


Asunto(s)
Amoxicilina , Antibacterianos , Implantes Dentales , Espectrometría Raman , Espectrometría Raman/métodos , Animales , Amoxicilina/análisis , Amoxicilina/administración & dosificación , Porcinos , Antibacterianos/análisis , Antibacterianos/administración & dosificación , Biopsia , Porcinos Enanos , Huesos/química , Huesos/efectos de los fármacos , Huesos/patología , Implantación Dental/métodos
16.
Anticancer Res ; 44(7): 2887-2897, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38925839

RESUMEN

BACKGROUND/AIM: This study aimed to investigate the structure and functions of the membrane formed around liquid nitrogen-treated bones in the osteogenesis and revitalization of frozen bone using a rat model. MATERIALS AND METHODS: Segmental defects were created in femurs of rats, and resected bones treated with liquid nitrogen [frozen bone (FB) group, n=20] or polymethylmethacrylate (PMMA group; n=20) were implanted as spacers. Histological analysis and quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) of the membrane around each spacer were performed for bone morphogenetic protein 2 (BMP2), transforming growth factor (TGF)-ß1, and vascular endothelial growth factor (VEGF). Furthermore, in week 2, spacers were removed from both groups (n=5 each), and autologous cancellous bone (ACB) harvested from the ilium was grafted into the defect. Radiological analysis was performed until bone union was observed. RESULTS: In week 2, similar two-layered membrane structures were observed in both groups; these matured into fibrous tissues over time. At each evaluation point, qRT-PCR showed higher expression of all factors in the FB than in the PMMA group. In the ACB graft model, the mean period to bone union and new bone volume were significantly shorter and greater, respectively, in the FB. Chondrocytes invaded the osteotomy site from the membrane in the FB, suggesting that endochondral ossification may occur and be related to osteogenesis. Additionally, fibroblasts and capillaries in the membrane invaded the surface of treated bone in week 2, and osteocytes were observed around them in weeks 6 and 8. CONCLUSION: Fibrous membranous tissue formed around liquid nitrogen-treated bones may be vital for osteogenesis and revitalization of frozen bones.


Asunto(s)
Osteogénesis , Factor A de Crecimiento Endotelial Vascular , Animales , Osteogénesis/efectos de los fármacos , Ratas , Factor A de Crecimiento Endotelial Vascular/metabolismo , Factor A de Crecimiento Endotelial Vascular/genética , Nitrógeno/metabolismo , Proteína Morfogenética Ósea 2/metabolismo , Proteína Morfogenética Ósea 2/genética , Masculino , Trasplante Óseo/métodos , Factor de Crecimiento Transformador beta1/metabolismo , Factor de Crecimiento Transformador beta1/genética , Polimetil Metacrilato/farmacología , Fémur/efectos de los fármacos , Fémur/metabolismo , Fémur/patología , Huesos/efectos de los fármacos , Huesos/metabolismo , Huesos/patología , Ratas Sprague-Dawley
17.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 32(3): 799-804, 2024 Jun.
Artículo en Chino | MEDLINE | ID: mdl-38926970

RESUMEN

OBJECTIVE: To investigate the clinical significance of bone metabolic indexes for disease assessment and curative effect monitoring in multiple myeloma (MM) bone disease (MBD) patients with different blood separation results. METHODS: A total of 134 newly diagnosed MM patients treated in Cangzhou Hospital of Integrated TCM-WM-Hebei were enrolled and divided into control group [119 cases, serum, colloid and red blood cell (RBC) from top to bottom of sample] and abnormal group (15 cases, serum, mixed layer of RBC and serum, colloid and RBC from top to bottom of sample) according to the results of blood separation. According to the imaging findings, MBD was classified into grade 0-4, grade 0-2 was mild, and grade 3-4 was severe. The MBD grade of patients in the two groups was analyzed. The curative effect of MBD patients after chemotherapy and the changes of blood separation results and bone metabolic indexes before and after treatment were evaluated. The correlation between ß2-microglobulin (MG) and bone metabolic indexes was analyzed by Pearson correlation analysis. RESULTS: In the control group, there were 69 cases of grade 0-2 and 50 cases of grade 3-4, while in the abnormal group, there were 5 cases of grade 0-2 and 10 cases of grade 3-4, the difference was statistically significant (P < 0.05). The serum ß2-MG, ß-CTX levels in abnormal group were both significantly higher than those in control group, while the levels of P1NP and osteocalcin (OC) were significantly lower (all P < 0.001). In the control group, there were 95 patients with ≥ partial response (PR) and the blood separation results were not changed, while 24 patients with 0.05). Compared with before treatment, the levels of ß-CTX and ß2-MG in the control group with unchanged blood separation results were significantly decreased (both P < 0.001), while the levels of P1NP and OC were significantly increased (P < 0.01, P < 0.001), and the level of each index in the patients transformed to abnormal blood separation result after treatment did not significantly change (P >0.05); the levels of ß-CTX and ß2-MG in the abnormal group transformed to normal blood separation result were significantly decreased (both P < 0.01), while the levels of P1NP and OC were significantly increased (P < 0.001, P < 0.01), and the level of each index in patients with unchanged blood separation results did not significantly change (P>0.05). Pearson correlation analysis showed that serum ß2-MG was positively correlated with ß-CTX (r =0.709, P < 0.001), and negatively correlated with P1NP and OC (r =-0.410,r =-0.412, both P < 0.001). CONCLUSION: MBD patients with abnormal blood separation results have higher bone disease grade and poor prognosis, which is closely related to the significant increase of bone resorption index ß-CTX level and decrease of bone formation index P1NP and OC levels, leading to more serious bone metabolic homeostasis disorder. The results of blood separation combined with the changes of bone metabolic indexes can be used as one of the comprehensive predictors of disease condition, efficacy monitoring and prognosis evaluation of MBD patients.


Asunto(s)
Huesos , Mieloma Múltiple , Humanos , Mieloma Múltiple/sangre , Huesos/metabolismo , Enfermedades Óseas , Microglobulina beta-2/sangre , Colágeno Tipo I/sangre , Osteocalcina/sangre , Masculino , Persona de Mediana Edad
18.
Int J Med Robot ; 20(4): e2653, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38934235

RESUMEN

BACKGROUND: Traditional open surgery for bone tumours sometimes has as a consequence an excessive removal of healthy bone tissue because of the limitations of rigid surgical instruments, increasing infection risk and recovery time. METHODS: We propose a remote robot with a 4.5-mm diameter bendable end-effector, offering four degrees of freedom for accessing the inside of the bone and performing tumour debridement. The preclinical studies evaluated the effectiveness, clinical scenario, and usability across 12 total surgeries-six phantom surgeries and six bovine bone surgeries. Evaluation criteria included skin incision size, bone window size, surgical time, removal rate, and conversion to open surgery. RESULTS: Preclinical studies demonstrated that the robotic approach requires significantly smaller incision size and procedure times than traditional open curettage. CONCLUSION: This study validated the performance of the proposed system by assessing its preclinical effectiveness and optimising surgical methods using human phantom and bovine bone tumour models.


Asunto(s)
Neoplasias Óseas , Diseño de Equipo , Procedimientos Quirúrgicos Robotizados , Animales , Procedimientos Quirúrgicos Robotizados/métodos , Procedimientos Quirúrgicos Robotizados/instrumentación , Neoplasias Óseas/cirugía , Bovinos , Proyectos Piloto , Humanos , Fantasmas de Imagen , Huesos/cirugía
19.
Open Vet J ; 14(5): 1146-1153, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38938441

RESUMEN

Background: Acute hemorrhage is fatal in equines with a complication of severe hypovolemic shock that causes a sudden death in such cases. Aim: This study was designed to report the influences of acute bleeding in conscious non-sedated donkeys (Equus asinus) on the hematobiochemical variables, acid-base, blood gas elements, and markers of inflammation and bone metabolism. Methods: Eight healthy donkeys were used where a total of 900 ml of whole blood was collected. Five blood samples were collected from each animal: just before collection of blood (T0); (2) 30 (T1), 60 (T2), 120 (T3), and 240 minutes (T4) later. The blood panels including total white blood cells, lymphocytes, neutrophils, red blood cell counts (RBCs), HCT, hemoglobin (Hg), and RBCs indices were measured. Biochemical parameters and electrolytes were evaluated. The activity of aspartate aminotransferase (AST), creatine kinase (CK), and γ-glutamyl transferase (GGT) were also determined. Complete acid-base and blood gas panels were assessed. Serum amyloid A (SAA), haptoglobin (Hp), osteocalcin (OC), bone alkaline phosphatase (b-ALP), and pyridinoline cross-links (PYD) were measured. Results: The RBCs, Hg, and HCT increased significantly at points T1, T2, and T3 compared to T0. The concentrations of total proteins and albumin decreased significantly at points T3 and T4. The blood urea nitrogen concentrations increased significantly at T4. Creatinine concentrations increased significantly at T2 and T3. The AST, GGT, and CK decreased significantly. On the other hand, glucose increased significantly at T3 and T4. The pH decreased significantly at points T1, T2, T3, and T4. The PCO2 increased significantly at T3 and T4. The BE, HCO3, and TCO2 values decreased significantly at T2, T3, and T4. Contrary, the AG increased significantly at points T3 and T4. The potassium increased significantly at T1-T4 and chloride decreased significantly at T3 and T4. Lactate showed significant increases at T1-T4. The SAA, Hp, OC, b-ALP, and PYD did not differ significantly at T1-T4. Conclusion: In conscious non-sedated donkeys, induced bleeding resulted in significant changes in the hematobiochemical elements, the acid-base status, and blood gas and electrolyte parameters. However, it did not change the markers of inflammation and bone metabolism.


Asunto(s)
Biomarcadores , Huesos , Equidae , Hemorragia , Inflamación , Animales , Equidae/sangre , Biomarcadores/sangre , Inflamación/veterinaria , Inflamación/sangre , Huesos/metabolismo , Hemorragia/veterinaria , Hemorragia/sangre , Análisis de los Gases de la Sangre/veterinaria , Equilibrio Ácido-Base , Masculino , Femenino
20.
Biomed Mater ; 19(5)2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38917826

RESUMEN

This study was designed to deposit nanodiamonds (NDs) on 3D-printed poly-ϵ-caprolactone (PCL) scaffolds and evaluate their effect on the surface topography, hydrophilicity, degradation, andin-vitrocell adhesion compared to untreated PCL scaffolds. The PCL scaffold specimens were 3D-printed by fused deposition modeling (FDM) technique with specific porosity parameters. The 3D-printed specimens' surfaces were modified by NDs deposition followed by oxygen plasma post-treatment using a plasma focus device and a non-thermal atmospheric plasma jet, respectively. Specimens were evaluated through morphological characterization by field emission scanning electron microscope (FESEM), microstructure characterization by Raman spectroscopy, chemical characterization by Fourier transform infrared (FTIR) spectroscopy, hydrophilicity degree by contact angle and water uptake measurements, andin-vitrodegradation measurements (n= 6). In addition,in-vitrobone marrow mesenchymal stem cells adhesion was evaluated quantitatively by confocal microscopy and qualitatively by FESEM at different time intervals after cell seeding (n= 6). The statistical significance level was set atp⩽ 0.05. The FESEM micrographs, the Raman, and FTIR spectra confirmed the successful surface deposition of NDs on scaffold specimens. The NDs treated specimens showed nano-scale features distributed homogeneously across the surface compared to the untreated ones. Also, the NDs treated specimens revealed a statistically significant smaller contact angle (17.45 ± 1.34 degrees), higher water uptake percentage after 24 h immersion in phosphate buffer saline (PBS) (21.56% ± 1.73), and higher degradation rate after six months of immersion in PBS (43.92 ± 0.77%). Moreover, enhanced cell adhesion at all different time intervals was observed in NDs treated specimens with higher nuclei area fraction percentage (69.87 ± 3.97%) compared to the untreated specimens (11.46 ± 1.34%). Surface deposition of NDs with oxygen-containing functional groups on 3D-printed PCL scaffolds increased their hydrophilicity and degradation rate with significant enhancement of thein-vitrocell adhesion compared to untreated PCL scaffolds.


Asunto(s)
Adhesión Celular , Interacciones Hidrofóbicas e Hidrofílicas , Células Madre Mesenquimatosas , Nanodiamantes , Poliésteres , Impresión Tridimensional , Propiedades de Superficie , Ingeniería de Tejidos , Andamios del Tejido , Andamios del Tejido/química , Ingeniería de Tejidos/métodos , Poliésteres/química , Células Madre Mesenquimatosas/citología , Nanodiamantes/química , Porosidad , Animales , Huesos , Espectroscopía Infrarroja por Transformada de Fourier , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Espectrometría Raman , Humanos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA