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Objetivo: Identificar as variáveis associadas ao absenteísmo por covid-19 avaliando a Qualidade de Vida no Trabalho dos profissionais de enfermagem da Unidade de Terapia Intensiva de um hospital público. Métodos: Estudo de abordagem quantitativa, observacional e retrospectivo, realizada na Unidade de Terapia Intensiva de um hospital público estadual em Manaus, aplicado dois questionários para a coleta de dados. Resultados: O absenteísmo teve influência das seguintes variáveis: técnicos de enfermagem (100%); dois vínculos empregatícios (64%); especialização nível médio ou pós-técnico (50%); renda até dois salários-mínimos (73,9%). Conclusão: Este estudo visa contribuir para o avanço do conhecimento científico por meio das relações entre o absenteísmo e a Covid-19 e, através do índice de Qualidade de Vida busca ajudar na criação de melhorias para a classe da enfermagem e de aspectos organizacionais. (AU)
Objective: To identify the variables associated with absenteeism by covid-19 evaluating the Quality of Life at Work of nursing professionals in the Intensive Care Unit of a public hospital. Methods: A quantitative, observational and retrospective study. The research was carried out in the Intensive Care Unit of a public hospital in Manaus, where two questionnaires were applied for data collection. Results: The absenteeism was influenced by the following variables: nursing technicians (100%); two jobs (64%); medium or post-technical specialization (50%); income up to two minimum wages (73.9%). Conclusion: This study aims to contribute to the advancement of scientific knowledge through the relationship between absenteeism and Covid-19 and, through the Quality of Life index, seeks to help create improvements for the nursing class and organizational aspects. (AU)
Objetivo: Identificar las variables asociadas al absentismo por covid-19 evaluando la Calidad de Vida Laboral de los profesionales de enfermería de la Unidad de Cuidados Intensivos de un hospital público. Métodos: Estudio cuantitativo, observacional y retrospectivo. La investigación se realizó en la Unidad de Cuidados Intensivos de un hospital público de Manaus, donde se aplicaron dos cuestionarios para la recogida de datos. Resultados: En el absentismo influyeron las siguientes variables: técnicos de enfermería (100%); dos empleos (64%); especialización media o postécnica (50%); ingresos de hasta dos salarios mínimos (73,9%). Conclusión: Este estudio pretende contribuir al avance del conocimiento científico a través de la relación entre el absentismo y el Covid-19 y, a través del índice de Calidad de Vida, busca ayudar en la creación de mejoras para la clase de enfermería y los aspectos organizativos. (AU)
Assuntos
Absenteísmo , Qualidade de Vida , COVID-19 , Unidades de Terapia Intensiva , Enfermagem do TrabalhoRESUMO
In the oil production industry, water is used as a fluid injected into the well to raise the oil when the well is depressurized. Water thus produced presents variations in the concentrations of dissolved salts, as there is a mixture of different types of water, related to its origin (such as connate water, sea water). Because it is reused in oil production, water needs to be monitored to maintain the standard suitable for its use as it can be hypersaline, contributing to the encrustation of pipes and contamination of underground water reservoirs. In this study, a noninvasive method was developed to determine the salt concentration in seawater. The method uses a detection system that contains a NaI(Tl) detector, a241Am source, and a sample holder to measure the mass attenuation coefficient of saltwater samples. For validation, the same setup was also simulated using the MCNPX code. Saltwater samples with different concentrations of NaCl and KBr were used as a proxy for seawater. The mass attenuation coefficients for the simulation exhibited the smallest relative errors (up to 6.2%), and the experimental ones exhibited the highest relative errors (up to 25%) when compared with theoretical values.
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Objective: This study aimed to investigate the root canal system morphology of maxillary first molar mesiobuccal (MB) roots in a Brazilian sub-population using micro-computed tomography. Methods: Ninety-six MB roots were scanned with a micro-CT (Skyscan 1173, Bruker). Three-dimensional images were analyzed regarding the number of pulp chamber orifices, the number and classification of the canals, the presence of accessory canals in different thirds of the root as well as the number and type of apical foramina. Results: A single entrance orifice was found in 53.0% of the samples, two in 43.9% and only 3.1% had three orifices. The second mesiobuccal root canal (MB2) was present at some portion of the root in 87.5% of the specimens. A single apical foramen was present in 16.7%, two in 22.9%, and three or more foramina in 60.4% of the roots. Only 55.3% and 76.1% of the root canals could be arranged by Weine's and Vertucci's classifications, respectively. Conclusion: The number of orifices at the pulp chamber level could not work as a predictor of the MB2 presence. The most prevalent canal configuration was Weine type IV / Vertucci type V. The anatomical complexity of the MB root could not be entirely classified by the current most accepted classifications.
Assuntos
Cavidade Pulpar/diagnóstico por imagem , Imageamento Tridimensional/métodos , Maxila/diagnóstico por imagem , Dente Molar/diagnóstico por imagem , Raiz Dentária/diagnóstico por imagem , Microtomografia por Raio-X/métodos , Brasil , Humanos , Ápice Dentário/diagnóstico por imagemRESUMO
The role of apoptosis-associated speck-like protein containing a caspase-1 recruitment domain (ASC) in bone healing remains to be understood. To address this issue, we investigated the requirement of inflammasome-related genes in response to bone morphogenetic protein 7 (BMP7)-induced osteoblast differentiation in vitro. To validate the importance of ASC on osteogenesis, we subjected wild-type (WT) and ASC knockout C57BL/6 mice (ASC KO) to tibia defect to evaluate the bone healing process (up to 28 days). Our in vitro data showed that there is an involvement of ASC during BMP7-induced osteoblast differentiation, concomitant to osteogenic biomarker expression. Indeed, primary osteogenic cells from ASC KO presented a lower osteogenic profile than those obtained from WT mice. To validate this hypothesis, we evaluated the bone healing process of tibia defects on both WT and ASC KO mice genotypes and the ASC KO mice were not able to fully heal tibia defects up to 28 days, whereas WT tibia defects presented a higher bone de novo volume at this stage, evidencing ASC as an important molecule during osteogenic phenotype. In addition, we have shown a higher involvement of runt-related transcription factor 2 in WT sections during bone repair, as well as circulating bone alkaline phosphatase isoform when both were compared with ASC KO mice behavior. Altogether, our results showed for the first time the involvement of inflammasome during osteoblast differentiation and osteogenesis, which opens new avenues to understand the pathways involved in bone healing.
Assuntos
Proteínas Adaptadoras de Sinalização CARD/metabolismo , Diferenciação Celular , Consolidação da Fratura , Osteoblastos/metabolismo , Osteogênese , Tíbia/metabolismo , Fraturas da Tíbia/metabolismo , Células 3T3 , Animais , Proteína Morfogenética Óssea 7/farmacologia , Proteínas Adaptadoras de Sinalização CARD/deficiência , Proteínas Adaptadoras de Sinalização CARD/genética , Diferenciação Celular/efeitos dos fármacos , Modelos Animais de Doenças , Feminino , Inflamassomos/efeitos dos fármacos , Inflamassomos/metabolismo , Mediadores da Inflamação/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Osteoblastos/efeitos dos fármacos , Osteoblastos/patologia , Osteogênese/efeitos dos fármacos , Transdução de Sinais , Tíbia/patologia , Tíbia/fisiopatologia , Fraturas da Tíbia/genética , Fraturas da Tíbia/patologia , Fraturas da Tíbia/fisiopatologia , Fatores de TempoRESUMO
The aim of this study is to evaluate the biocompatibility and osteoconductivity in surgical defects of sheep tibias filled with 1% strontium-containing nanostructured hydroxyapatite microspheres (SrHA), stoichiometric hydroxyapatite without strontium microspheres (HA), or blood clots. Santa Ines sheep were subjected to three perforations on the medial side of the left tibia. The biomaterials were characterized by X-ray Diffraction (XRD) and Fourier Transform Infrared (FTIR) before implantation and by X-Ray Microfluorescence (µFRX) and Scanning Electron Microscopy (SEM) after sheep tibias implantation. Surgical defects were filled with blood clots (control), SrHA (Group 1) or HA (Group 2). After 30 days, 5-µm bone blocks were obtained for histological evaluation, and the blocks obtained from 1 animal were embedded in methylmethacrylate for undecalcified sections. Mononuclear inflammatory infiltrate remained mild in all experimental groups. Giant cells were observed surrounding biomaterials particles of both groups and areas of bone formation were detected in close contact with biomaterials. All groups showed newly formed bone from the periphery to the center of the defects, which the control, HA and SrHA presented 36.4% (± 21.8), 31.2% (± 14.7) and 26.2% (± 12.9) of newly formed bone density, respectively, not presenting statistical differences. In addition, the connective tissue density did not show any significant between groups. The SrHA showing a higher volume density of biomaterial (51.2 ± 14.1) present in the defect compared to HA (32.6 ± 8.5) after 30 days (p = 0.03). Microspheres containing 1% SrHA or HA can be considered biocompatible, have osteoconductive properties and may be useful biomaterials for clinical applications.
Assuntos
Regeneração Óssea/efeitos dos fármacos , Substitutos Ósseos/farmacologia , Hidroxiapatitas/farmacologia , Nanoestruturas/química , Estrôncio/farmacologia , Cicatrização/efeitos dos fármacos , Animais , Feminino , Teste de Materiais , Microscopia Eletrônica de Varredura , Modelos Animais , Reprodutibilidade dos Testes , Ovinos , Espectroscopia de Infravermelho com Transformada de Fourier , Tíbia/efeitos dos fármacos , Fatores de Tempo , Difração de Raios X , Microtomografia por Raio-XRESUMO
Bone mineral density (BMD) seems not to be decreased in young patients given long-term suppressive doses of levothyroxine (LT4), but information regarding the bone microstructure in these patients is lacking. The aim of this study was to determine whether supraphysiologic doses of LT4, initiated during childhood or adolescence for treatment of differentiated thyroid carcinoma (DTC), have any detrimental effects on bone microarchitecture as evaluated by high-resolution peripheral quantitative computed tomography (HR-pQCT). Seventeen patients (27.3 ± 7.1 years old) with DTC with subclinical hyperthyroidism since adolescence and 34 healthy volunteers matched for age, sex, and body mass index were studied by dual-energy X-ray absorptiometry (DXA) to determine the areal BMD at the lumbar spine, hip, and proximal third of the radius. Volumetric BMD and structural parameters of the trabecular and cortical bone were assessed by HR-pQCT of the distal radius and distal tibia. DTC patients were given suppressive doses of LT4 starting at a mean age of 12.6 years, and the mean duration of treatment was 14.2 years. In DTC patients, clinical parameters did not correlate with DXA or HR-pQCT parameters. No differences were found between the patients and controls with respect to BMD and Z scores at any site evaluated by DXA, and no differences were found in the bone microstructure parameters evaluated by HR-pQCT. This cross-sectional study suggests that long-standing suppressive therapy with LT4 during the attainment of peak bone mass may have no significant adverse effects on bone density or microarchitecture.
Assuntos
Densidade Óssea/efeitos dos fármacos , Rádio (Anatomia)/metabolismo , Neoplasias da Glândula Tireoide/tratamento farmacológico , Tiroxina/administração & dosagem , Adolescente , Adulto , Brasil , Estudos Transversais , Humanos , Pessoa de Meia-Idade , Rádio (Anatomia)/patologia , Neoplasias da Glândula Tireoide/metabolismo , Neoplasias da Glândula Tireoide/patologia , Tiroxina/efeitos adversos , Adulto JovemRESUMO
Abstract The aim of this study is to evaluate the biocompatibility and osteoconductivity in surgical defects of sheep tibias filled with 1% strontium-containing nanostructured hydroxyapatite microspheres (SrHA), stoichiometric hydroxyapatite without strontium microspheres (HA), or blood clots. Santa Ines sheep were subjected to three perforations on the medial side of the left tibia. The biomaterials were characterized by X-ray Diffraction (XRD) and Fourier Transform Infrared (FTIR) before implantation and by X-Ray Microfluorescence (µFRX) and Scanning Electron Microscopy (SEM) after sheep tibias implantation. Surgical defects were filled with blood clots (control), SrHA (Group 1) or HA (Group 2). After 30 days, 5-µm bone blocks were obtained for histological evaluation, and the blocks obtained from 1 animal were embedded in methylmethacrylate for undecalcified sections. Mononuclear inflammatory infiltrate remained mild in all experimental groups. Giant cells were observed surrounding biomaterials particles of both groups and areas of bone formation were detected in close contact with biomaterials. All groups showed newly formed bone from the periphery to the center of the defects, which the control, HA and SrHA presented 36.4% (± 21.8), 31.2% (± 14.7) and 26.2% (± 12.9) of newly formed bone density, respectively, not presenting statistical differences. In addition, the connective tissue density did not show any significant between groups. The SrHA showing a higher volume density of biomaterial (51.2 ± 14.1) present in the defect compared to HA (32.6 ± 8.5) after 30 days (p = 0.03). Microspheres containing 1% SrHA or HA can be considered biocompatible, have osteoconductive properties and may be useful biomaterials for clinical applications.
Assuntos
Animais , Feminino , Estrôncio/farmacologia , Cicatrização/efeitos dos fármacos , Regeneração Óssea/efeitos dos fármacos , Substitutos Ósseos/farmacologia , Nanoestruturas/química , Hidroxiapatitas/farmacologia , Tíbia/efeitos dos fármacos , Fatores de Tempo , Difração de Raios X , Teste de Materiais , Ovinos , Microscopia Eletrônica de Varredura , Reprodutibilidade dos Testes , Espectroscopia de Infravermelho com Transformada de Fourier , Modelos Animais , Microtomografia por Raio-XRESUMO
INTRODUCTION: The aim of this study was to make a 3-dimensional comparison of the canal transportation and changes in apical geometry using micro-computed tomographic imaging after canal preparation with K3 (SybronEndo, Orange, CA) and K3XF (SybronEndo) file systems. METHODS: Twenty-eight mandibular molars were randomly divided into 2 groups according to the rotary system used in instrumentation: K3 or K3XF. The specimens were scanned by micro-computed tomographic imaging before and after instrumentation. Images before and after instrumentation from each group were compared with regard to canal volume, surface area, and structure model index (SMI) (paired t test, P < .05). After instrumentation, the canals from each group were compared regarding the changes in volume, surface area, SMI, and canal transportation in the last 4 apical mm (t test, P < .05). RESULTS: Instrumentation with the 2 rotary systems significantly changed the canal volume, surface area, and SMI (P < .05). There were no significant differences between instrument types concerning these parameters (P > .05). There were no significant differences between the 2 groups with regard to canal transportation in the last 4 apical mm (P > .05). CONCLUSIONS: Both rotary systems showed adequate canal preparations with reduced values of canal transportation. Heat treatment did not influence changes in root canal geometry in the apical region.
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Ligas , Ligas Dentárias , Cavidade Pulpar/anatomia & histologia , Temperatura Alta , Preparo de Canal Radicular/instrumentação , Cavidade Pulpar/diagnóstico por imagem , Humanos , Mandíbula , Dente Molar/anatomia & histologia , Dente Molar/diagnóstico por imagem , Microtomografia por Raio-XRESUMO
OBJECTIVE: Osteoporosis is a serious and underestimated complication of endogenous hypercortisolism that results in an increased risk of fractures, even in patients with normal or slightly decreased bone mineral density (BMD). Alterations in bone microarchitecture, a very important component of bone quality, may explain bone fragility. The aim of this study was to investigate bone density and microarchitecture in a cohort of patients with endogenous Cushing's syndrome (CS). DESIGN: Cross-sectional study. PATIENTS: Thirty patients with endogenous active CS and fifty-one age-, sex- and body mass index-matched controls were included. MEASUREMENTS: Participants were studied for areal BMD (dual-energy X-ray absorptiometry) of the lumbar spine (LS), femoral neck (FN), total femur (TF) and radius (33%), and for volumetric bone density (vBMD) and structure using high-resolution peripheral quantitative computed tomography (HR-pQCT) of the distal radius and distal tibia. RESULTS: Patients with active CS exhibited lower areal BMD and Z-score values in the LS, FN and TF (P < 0·003 for all comparisons). At HR-pQCT, the patients with CS also had lower cortical area (P = 0·009 at the radius and P = 0·002 at the tibia), lower cortical thickness (P = 0·02 at the radius and P = 0·002 at the tibia), lower cortical density (P = 0·008 at the tibia) and lower total vBMD (P = 0·002 at the tibia). After the exclusion of hypogonadal individuals, the patients with CS maintained the same microarchitectural and densitometric alterations described above. CONCLUSIONS: Endogenous hypercortisolism has deleterious effects on bone, especially on cortical bone microstructure. These effects seem to be a more important determinant of bone impairment than gonadal status.
Assuntos
Densidade Óssea/fisiologia , Síndrome de Cushing/metabolismo , Absorciometria de Fóton , Adolescente , Adulto , Idoso , Estudos Transversais , Síndrome de Cushing/complicações , Feminino , Colo do Fêmur/metabolismo , Colo do Fêmur/patologia , Fraturas Ósseas/metabolismo , Fraturas Ósseas/patologia , Humanos , Vértebras Lombares/metabolismo , Vértebras Lombares/patologia , Masculino , Pessoa de Meia-Idade , Osteoporose/etiologia , Osteoporose/metabolismo , Rádio (Anatomia)/metabolismo , Rádio (Anatomia)/patologia , Adulto JovemRESUMO
The cranial base, composed of the midline and lateral basicranium, is a structurally important region of the skull associated with several key traits, which has been extensively studied in anthropology and primatology. In particular, most studies have focused on the association between midline cranial base flexion and relative brain size, or encephalization. However, variation in lateral basicranial morphology has been studied less thoroughly. Platyrrhines are a group of primates that experienced a major evolutionary radiation accompanied by extensive morphological diversification in Central and South America over a large temporal scale. Previous studies have also suggested that they underwent several evolutionarily independent processes of encephalization. Given these characteristics, platyrrhines present an excellent opportunity to study, on a large phylogenetic scale, the morphological correlates of primate diversification in brain size. In this study we explore the pattern of variation in basicranial morphology and its relationship with phylogenetic branching and with encephalization in platyrrhines. We quantify variation in the 3D shape of the midline and lateral basicranium and endocranial volumes in a large sample of platyrrhine species, employing high-resolution CT-scans and geometric morphometric techniques. We investigate the relationship between basicranial shape and encephalization using phylogenetic regression methods and calculate a measure of phylogenetic signal in the datasets. The results showed that phylogenetic structure is the most important dimension for understanding platyrrhine cranial base diversification; only Aotus species do not show concordance with our molecular phylogeny. Encephalization was only correlated with midline basicranial flexion, and species that exhibit convergence in their relative brain size do not display convergence in lateral basicranial shape. The evolution of basicranial variation in primates is probably more complex than previously believed, and understanding it will require further studies exploring the complex interactions between encephalization, brain shape, cranial base morphology, and ecological dimensions acting along the species divergence process.
Assuntos
Evolução Biológica , Encéfalo/anatomia & histologia , Platirrinos/anatomia & histologia , Base do Crânio/anatomia & histologia , Animais , Filogenia , Análise de RegressãoRESUMO
INTRODUCTION: Mechanical interlocking between a mini-implant (MI) and the bone substrate reflects directly on the primary stability achieved. The purposes of this study were to evaluate MI design performance in distinct bone substrates and correlate geometric characteristics with insertion site quality. METHODS: Two types of self-drilling MIs (1.6 × 8 mm) were allocated to 2 groups according to their geometric designs: Tomas system (Dentaurum, Ispringen, Germany) and Dual-Top (Rocky Mountain Orthodontics, Denver, Colo). Forty sections (8 × 10 mm) were taken from bovine pelvic ilium and pubic bone. Geometric design characteristics were evaluated using scanning electron microscope imaging and Image-Pro Insight software (Media Cybernetics, Rockville, Md). Bone quality parameters were assessed with a microcomputed tomography system, and primary stability was evaluated by insertion torque and pull-out strength. Intergroup comparisons were performed with analysis of variance and Tukey tests, and the Pearson correlation test was carried out (P <0.05). RESULTS: No significant difference was observed in the comparisons of the groups (Tomas: insertion torque, 12.87 N·cm; pull-out strength, 181 N; and Dual-Top: insertion torque, 9.95 N·cm; pull-out strength, 172.5 N) in the ilium. However, the Tomas group had a marked increase in insertion torque (25.08 N·cm; P <0.05) in the pubic bone. CONCLUSIONS: MI mechanical performance differed according to bone quality parameters, indicating that certain geometric parameters may be set depending on the insertion substrate.
Assuntos
Osso e Ossos/anatomia & histologia , Implantes Dentários , Procedimentos de Ancoragem Ortodôntica/instrumentação , Desenho de Aparelho Ortodôntico , Osseointegração/fisiologia , Ligas , Animais , Densidade Óssea/fisiologia , Bovinos , Ligas Dentárias/química , Análise do Estresse Dentário/instrumentação , Ílio/anatomia & histologia , Processamento de Imagem Assistida por Computador/métodos , Microscopia Eletrônica de Varredura , Miniaturização , Osso Púbico/anatomia & histologia , Estresse Mecânico , Propriedades de Superfície , Titânio/química , Torque , Microtomografia por Raio-X/métodosRESUMO
OBJECTIVE: To compare the primary stability of miniscrews inserted into bone blocks of different bone mineral densities (BMDs) with and without cortical bone, and investigate whether some trabecular properties could influence primary stability. MATERIALS AND METHODS: Fifty-two bone blocks were extracted from fresh bovine pelvic bone. Four groups were created based on bone type (iliac or pubic region) and presence or absence of cortical bone. Specimens were micro-computed tomography imaged to evaluate trabecular thickness, trabecular number, trabecular separation, bone volume density (BV/TV), BMD, and cortical thickness. Miniscrews 1.4 mm in diameter and 6 mm long were inserted into the bone blocks, and primary stability was evaluated by insertion torque (IT), mini-implant mobility (PTV), and pull-out strength (PS). RESULTS: Intergroup comparison showed lower levels of primary stability when the BMD of trabecular bone was lower and in the absence of cortical bone (P≤.05). The Pearson correlation test showed correlation between trabecular number, trabecular thickness, BV/TV, trabecular BMD, total BMD, and IT, PTV, and PS. There was correlation between cortical thickness and IT and PS (P≤.05). CONCLUSION: Cancellous bone plays an important role in primary stability of mini-implants in the presence or absence of cortical bone.
Assuntos
Parafusos Ósseos , Osso e Ossos/anatomia & histologia , Aparelhos Ortodônticos , Anatomia Transversal/métodos , Animais , Densidade Óssea/fisiologia , Osso e Ossos/cirurgia , Bovinos , Análise do Estresse Dentário/instrumentação , Durapatita/química , Ílio/cirurgia , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Miniaturização , Procedimentos de Ancoragem Ortodôntica/instrumentação , Osso Púbico/cirurgia , Estresse Mecânico , Torque , Microtomografia por Raio-X/métodosRESUMO
OBJECTIVE: Obesity and osteoporosis seem to have a common pathogenesis, especially because bone and adipose tissue have common origins. Since early weaning (EW) decreases adipogenesis and osteogenesis in neonate, further programming for obesity and hyperleptinemia, we hypothesized that these changes in adipogenesis could affect bone metabolism. MATERIALS/METHODS: Lactating rats were separated into 3 groups: control - dams whose pups ate milk throughout lactation; mechanical EW (MEW) - dams were involved with a bandage interrupting suckling in the last 3days of lactation; pharmacological EW (PEW) - dams were bromocriptine-treated (0.5mg/twice a day via intraperitoneal injection) 3days before weaning. The adult offspring was subjected to dual-energy X-ray absorptiometry and bone tissue was also evaluated by computed tomography, microcomputed tomography and biomechanical tests, beyond serum analyses. RESULTS: MEW and PEW presented higher total bone mineral density (BMD), total bone mineral content, spine BMD and bone area in postnatal day 150 (PN150). In PN180, both groups also presented increase of these parameters and higher femur BMD and fourth lumbar vertebra (LV4) BMD, femoral head radiodensity and LV4 vertebral body radiodensity, trabecular number, stiffness and break load; lower trabecular separation, maximal deformation and break deformation, and also hyperleptinemia and higher visceral fat mass and 25-hydroxivitamin D, whereas parathyroid hormone was unchanged. Serum C-terminal cross-linked telopeptide of type I collagen was lower for both groups. CONCLUSIONS: Since both models program for obesity and increased bone mass, and leptin increases plasma vitamin D levels, probably leptin is the link between obesity and higher bone mass.
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Densidade Óssea/fisiologia , Osso e Ossos/metabolismo , Osso e Ossos/fisiologia , Obesidade/metabolismo , Adipogenia/fisiologia , Animais , Colágeno Tipo I/metabolismo , Ingestão de Alimentos/fisiologia , Feminino , Lactação/metabolismo , Lactação/fisiologia , Masculino , Obesidade/sangue , Obesidade/fisiopatologia , Osteogênese/fisiologia , Hormônio Paratireóideo/metabolismo , Ratos , Ratos Wistar , Vitamina D/metabolismo , DesmameRESUMO
Bone marrow stromal cells (BMSCs) are a valuable resource for skeletal regenerative medicine because of their osteogenic potential. In spite of the very general term "stem cell," this population of cells is far from homogeneous, and different BMSCs clones have greatly different phenotypic properties and, therefore, potentially different therapeutic potential. Adherence to a culture flask surface is a primary defining characteristic of BMSCs. We hypothesized that based on the adherence time we could obtain an enriched population of cells with a greater therapeutic potential. We characterized two populations of bone marrow-derived cells, those that adhered by three days (R-cells) and those that did not adhere by three days but did by six days (L-cells). Clones derived from L-cells could be induced into adipogenic, chondrogenic, and osteogenic differentiation in vitro. L-cells appeared to have greater proliferative capacity, as manifested by larger colony diameter and clones with higher CD146 expression. Only clones from L-cells developed bone marrow stroma in vivo. We conclude that the use of late adherence of BMSCs is one parameter that can be used to enrich for cells that will constitute a superior final product for cell therapy in orthopedics.
Assuntos
Adesão Celular/genética , Diferenciação Celular , Células-Tronco Mesenquimais/citologia , Osteogênese , Nicho de Células-Tronco , Adulto , Antígeno CD146/biossíntese , Linhagem da Célula/genética , Células Cultivadas , Feminino , Fibroblastos/citologia , Regulação da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Medicina RegenerativaRESUMO
This study investigates the long-term biocompatibility of 0.5 % zinc-containing hydroxyapatite compared with hydroxyapatite. Spheres (425 < ∅ < 550) of both materials were produced by extrusion of ceramic slurry in calcium chloride and characterized by FTIR, XRD, XRF and SEM. Fifteen White New Zealand rabbits were submitted to general anesthesia, and an perforation (2 mm), was made in each tibia, one for zinc-containing hydroxyapatite sphere implantation and one for hydroxyapatite sphere implantation. After 26, 52 and 78 weeks, the animals were euthanized, and the fragment containing the biomaterial was harvested. A 30-50 µm section was obtained for histological analysis in bright field and polarized light. SEM images revealed similar morphologies between the tested biomaterials. Histological analysis showed that there was no difference between the test groups. The morphometric analysis, however, indicates that there was a greater absorption. The materials are biocompatible, promote osteogenesis and that the zinc-containing hydroxyapatite microspheres were absorbed more quickly.
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Substitutos Ósseos/síntese química , Substitutos Ósseos/uso terapêutico , Durapatita/química , Durapatita/uso terapêutico , Fraturas da Tíbia/terapia , Zinco/química , Zinco/uso terapêutico , Animais , Feminino , Estudos Longitudinais , Masculino , Teste de Materiais , Coelhos , Fraturas da Tíbia/patologia , Resultado do TratamentoRESUMO
INTRODUCTION: Acromegaly is one of the causes of secondary osteoporosis, although studies of bone mineral density (BMD) have yielded conflicting results and none of them have evaluated the bone properties. OBJECTIVES AND PATIENTS: Our objective was to correlate, in a cohort of 82 acromegalic patients, BMD and bone microarchitecture, using dual-energy x-ray absorptiometry and high-resolution peripheral quantitative computed tomography, with the presence of type 2 diabetes mellitus (T2DM), disease activity, and gonadal status and to compare these bone parameters between 45 eugonadal acromegalic patients and 45 healthy controls. RESULTS: Acromegalic patients with T2DM had lower trabecular density and trabecular bone volume to tissue volume ratio in the distal tibia. Patients with active acromegaly exhibited a higher BMD and T-score in the lumbar spine (P = .02 for both) and a higher cortical density in the distal tibia when compared with those with controlled acromegaly (P = .001). After multiple linear regression (including age, presence of T2DM, acromegaly activity, and gonadal status), eugonadism remained the main determinant of bone parameters. The 45 acromegalic patients with eugonadism were compared with 45 age- and sex-matched controls and exhibited lower trabecular densities and impaired microstructures. CONCLUSIONS: Acromegaly appears to have a deleterious effect on trabecular bone microarchitecture, and in this specific population, the gonadal status might be more important than T2DM or acromegaly activity in determining bone health. High-resolution peripheral quantitative computed tomography seems promising for evaluating acromegalic bone properties and for addressing the limitations posed by dual-energy x-ray absorptiometry.
Assuntos
Acromegalia/diagnóstico por imagem , Acromegalia/metabolismo , Densidade Óssea , Osso e Ossos/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Acromegalia/complicações , Acromegalia/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Densidade Óssea/fisiologia , Osso e Ossos/metabolismo , Estudos de Casos e Controles , Estudos de Coortes , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/diagnóstico por imagem , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/metabolismo , Feminino , Humanos , Vértebras Lombares/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Tíbia/diagnóstico por imagemRESUMO
PURPOSE: To verify the effects of tibolone administration on trabecular and cortical bone of ovariectomized female rats by computed radiography system (CRS). METHODS: The experiment was performed on two groups of rats previously ovariectomized, one received tibolone (OVX+T) while the other did not (OVX), those groups were compared to a control group (C) not ovariectomized. Tibolone administration (1mg/day) began thirty days after the ovariectomy and the treatment remained for five months. At last, the animals were euthanized and femurs and tibias collected. Computed radiographies of the bones were obtained and the digital images were used to determine the bone optical density and cortical thickness on every group. All results were statistically evaluated with significance set at P<0.05%. RESULTS: Tibolone administration was shown to be beneficial only in the densitometric analysis of the femoral head, performing higher optical density compared to OVX. No difference was found in cortical bone thickness. CONCLUSION: Ovariectomy caused bone loss in the analyzed regions and tibolone administered in high doses over a long period showed not to be fully beneficial, but preserved bone mass in the femoral head.
Assuntos
Densidade Óssea/efeitos dos fármacos , Moduladores de Receptor Estrogênico/efeitos adversos , Estrogênios/deficiência , Fêmur/diagnóstico por imagem , Norpregnenos/efeitos adversos , Ovariectomia/efeitos adversos , Tíbia/diagnóstico por imagem , Animais , Modelos Animais de Doenças , Métodos Epidemiológicos , Moduladores de Receptor Estrogênico/administração & dosagem , Feminino , Fêmur/efeitos dos fármacos , Fêmur/patologia , Processamento de Imagem Assistida por Computador , Norpregnenos/administração & dosagem , Radiografia , Ratos , Ratos Wistar , Tíbia/efeitos dos fármacos , Tíbia/patologiaRESUMO
PURPOSE: To verify the effects of tibolone administration on trabecular and cortical bone of ovariectomized female rats by computed radiography system (CRS). METHODS: The experiment was performed on two groups of rats previously ovariectomized, one received tibolone (OVX+T) while the other did not (OVX), those groups were compared to a control group (C) not ovariectomized. Tibolone administration (1mg/day) began thirty days after the ovariectomy and the treatment remained for five months. At last, the animals were euthanized and femurs and tibias collected. Computed radiographies of the bones were obtained and the digital images were used to determine the bone optical density and cortical thickness on every group. All results were statistically evaluated with significance set at P<0.05 percent. RESULTS: Tibolone administration was shown to be beneficial only in the densitometric analysis of the femoral head, performing higher optical density compared to OVX. No difference was found in cortical bone thickness. CONCLUSION: Ovariectomy caused bone loss in the analyzed regions and tibolone administered in high doses over a long period showed not to be fully beneficial, but preserved bone mass in the femoral head.
OBJETIVO: Verificar o efeito da administração de tibolona no tecido ósseo cortical e trabecular de ratas castradas através de radiografia computadorizada. MÉTODOS: O experimento foi realizado em dois grupos de ratas previamente ooforectomizadas, onde um grupo recebeu tibolona (OVX+T) e o outro não (OVX). Esses grupos foram comparados a um grupo controle (C) não ooforectomizado. A administração de tibolona (1mg/dia) começou trinta dias após a ooforectomia e o tratamento teve duração de cinco meses. No final, os animais foram mortos e fêmures e tibias coletados. As radiografias computadorizadas dos ossos foram obtidas e as imagens digitais usadas para determinar a densidade óssea e a espessura cortical em todos os grupos. Todos os resultados foram avaliados estatisticamente com significância estabelecida a 5 por cento. RESULTADOS: A administração de tibolona mostrou ser benéfica apenas para análise densitométrica da cabeça do fêmur, apresentando maiores valores de densidade comparada ao grupo OVX. Nenhuma diferença significativa foi encontrada para espessura óssea cortical. CONCLUSÃO: A ooforectomia ocasionou perda óssea nas regiões analisadas e a tibolona administrada, em dose elevada e durante um longo período, mostrou não ser totalmente benéfica, porém preservou a massa óssea na cabeça femoral.
Assuntos
Animais , Feminino , Ratos , Densidade Óssea/efeitos dos fármacos , Moduladores de Receptor Estrogênico/efeitos adversos , Estrogênios/deficiência , Fêmur , Norpregnenos/efeitos adversos , Ovariectomia/efeitos adversos , Tíbia , Modelos Animais de Doenças , Métodos Epidemiológicos , Moduladores de Receptor Estrogênico/administração & dosagem , Fêmur/efeitos dos fármacos , Fêmur/patologia , Processamento de Imagem Assistida por Computador , Norpregnenos/administração & dosagem , Ratos Wistar , Tíbia/efeitos dos fármacos , Tíbia/patologiaRESUMO
PURPOSE: To verify the effects of tibolone administration on trabecular and cortical bone of ovariectomized female rats by computed radiography system (CRS). METHODS: The experiment was performed on two groups of rats previously ovariectomized, one received tibolone (OVX+T) while the other did not (OVX), those groups were compared to a control group (C) not ovariectomized. Tibolone administration (1mg/day) began thirty days after the ovariectomy and the treatment remained for five months. At last, the animals were euthanized and femurs and tibias collected. Computed radiographies of the bones were obtained and the digital images were used to determine the bone optical density and cortical thickness on every group. All results were statistically evaluated with significance set at P<0.05 percent. RESULTS: Tibolone administration was shown to be beneficial only in the densitometric analysis of the femoral head, performing higher optical density compared to OVX. No difference was found in cortical bone thickness. CONCLUSION: Ovariectomy caused bone loss in the analyzed regions and tibolone administered in high doses over a long period showed not to be fully beneficial, but preserved bone mass in the femoral head.(AU)
OBJETIVO: Verificar o efeito da administração de tibolona no tecido ósseo cortical e trabecular de ratas castradas através de radiografia computadorizada. MÉTODOS: O experimento foi realizado em dois grupos de ratas previamente ooforectomizadas, onde um grupo recebeu tibolona (OVX+T) e o outro não (OVX). Esses grupos foram comparados a um grupo controle (C) não ooforectomizado. A administração de tibolona (1mg/dia) começou trinta dias após a ooforectomia e o tratamento teve duração de cinco meses. No final, os animais foram mortos e fêmures e tibias coletados. As radiografias computadorizadas dos ossos foram obtidas e as imagens digitais usadas para determinar a densidade óssea e a espessura cortical em todos os grupos. Todos os resultados foram avaliados estatisticamente com significância estabelecida a 5 por cento. RESULTADOS: A administração de tibolona mostrou ser benéfica apenas para análise densitométrica da cabeça do fêmur, apresentando maiores valores de densidade comparada ao grupo OVX. Nenhuma diferença significativa foi encontrada para espessura óssea cortical. CONCLUSÃO: A ooforectomia ocasionou perda óssea nas regiões analisadas e a tibolona administrada, em dose elevada e durante um longo período, mostrou não ser totalmente benéfica, porém preservou a massa óssea na cabeça femoral.(AU)