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1.
Braz Oral Res ; 34: e016, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32130363

RESUMO

Horizontal bone loss after tooth extraction is a common finding that demands bone reconstruction in various cases. The aim of this study was to assess the horizontal alveolar status in partially and completely edentulous patients using cone-beam computed tomography (CBCT). In total, 1516 CBCT scans of 1404 adult patients were analyzed. Assessment of the images was performed in accordance with the previously published horizontal alveolar change (HAC) classification, which categorizes horizontal bone defects into four classes: HAC 1, HAC 2, HAC 3 and HAC 4 (from the least severe to the most severe condition). Analysis of 1048 scans from partially edentulous patients presented a distribution of 63.55%, 22.14%, 13.36% and 0.95% in HAC 1, HAC 2, HAC 3 and HAC 4, respectively. Analysis of 468 scans from completely edentulous patient images presented a distribution of 19.87%, 28.63%, 41.67% and 9.83% in HAC 1, HAC 2, HAC 3 and HAC 4, respectively. Based on these results, as in HAC 4, no cancellous bone was found between the cortical buccal and lingual/palatal bone plates, it seems reasonable to state that the absence of cancellous bone is higher in completely edentulous patients than in partially edentulous patients. Therefore, the absence of cancellous bone seems to be higher in completely edentulous than in partially edentulous patients.


Assuntos
Perda do Osso Alveolar/epidemiologia , Perda do Osso Alveolar/patologia , Processo Alveolar/patologia , Boca Edêntula/epidemiologia , Boca Edêntula/patologia , Adolescente , Adulto , Idoso , Perda do Osso Alveolar/diagnóstico por imagem , Processo Alveolar/diagnóstico por imagem , Aumento do Rebordo Alveolar , Brasil/epidemiologia , Osso Esponjoso/diagnóstico por imagem , Osso Esponjoso/patologia , Tomografia Computadorizada de Feixe Cônico/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Boca Edêntula/diagnóstico por imagem , Prevalência , Estudos Retrospectivos , Adulto Jovem
2.
Physiol Res ; 68(Suppl 2): S121-S129, 2019 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-31842575

RESUMO

This article is focused on endocrine-mediated osteoporosis caused by growth hormone (GH) disorders; adult GH deficiency and acromegaly. GH and insulin like growth factor-1 (IGF-1) stimulate linear bone growth through complex hormonal interactions and activates epiphyseal prechondrocytes. GH, via receptor activator of nuclear factor-kappaB (RANK), its ligand (RANK-L), and the osteoprotegerin system, stimulates production of osteoprotegerin and its accumulation in bone matrix. Malfunction of this mechanism, could lead to specific bone impairment. However, the primary problem of bone disease in GH secretion disorders is the primary prevention of osteoporotic fractures, so it is important to determine bone quality that better reflects the patient's actual predisposition to fracture. A method estimating bone quality from lumbar spine dual X-ray absorptiometry (DXA) scans is trabecular bone score (TBS). TBS in addition to bone mineral density (BMD) is a promising predictor of the osteoporotic fracture risk in women with postmenopausal osteopenia. In acromegaly TBS better defines risk of fracture because BMD is normal or even increased. TBS helps to monitor the effect of growth hormone therapy. Despite these findings, TBS should not be used alone, but a comprehensive consideration of all fracture risk factors, BMD and bone turnover markers is necessary.


Assuntos
Doenças Ósseas Endócrinas/patologia , Osso Esponjoso/patologia , Hormônio do Crescimento/deficiência , Humanos
3.
Physiol Res ; 68(Suppl 2): S149-S156, 2019 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-31842578

RESUMO

Osteoporosis is an increasingly widespread disease, as well as diabetes mellitus. It is now accepted that osteoporotic fractures are a serious co-morbidity and complication of diabetes. Despite of good bone mineral density in Type 2 Diabetes (T2DM) patients is the fracture risk elevated. It is due to reduced bone quality. To determine the effect of glycemic compensation on bone density and trabecular bone score (TBS) in T2DM. We analyzed a cohort of 105 postmenopausal women with T2DM. For all patients, central bone density (spinal and lumbar spine) was tested by DXA methodology, glycemic control parameters were assessed, and anthropometric parameters were measured. Bone quality was analyzed using TBS software. The results were statistically processed. Good glycemic compensation with glycated hemoglobin (A1c) value <7.0 % DCCT did not lead to BMD changes in patients with T2DM. However, patients with HbA1c <7 % DCCT had significantly better TBS (1.254±0.148 vs. 1.166±0.094, p=0.01). There was a negative correlation between TBS and glycated hemoglobin (r= -0,112, p<0.05) with glycemic fasting (r= -0.117, p<0.05). The optimal effect on TBS is achieved when all three markers of glycemic compensation (glycated hemoglobin, fasting plasma glucose and postprandial glycemia) are in optimal range. By using ROC curves glycated hemoglobin has the most significant effect on TBS. Optimal glycemic compensation, evaluated by glycated hemoglobin, does not lead to changes in BMD but has a beneficial effect on TBS in T2DM. Good glycemic control is required also for reduction of the risk of osteoporosis and osteoporotic fractures.


Assuntos
Densidade Óssea , Osso Esponjoso/efeitos dos fármacos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hemoglobina A Glicada/metabolismo , Hipoglicemiantes/uso terapêutico , Osso Esponjoso/patologia , Estudos Transversais , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/patologia , Quimioterapia Combinada , Feminino , Humanos , Hipoglicemiantes/farmacologia , Metformina/farmacologia , Metformina/uso terapêutico , Pessoa de Meia-Idade , Pós-Menopausa , Fosfato de Sitagliptina/farmacologia , Fosfato de Sitagliptina/uso terapêutico
4.
PLoS One ; 14(12): e0227133, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31881044

RESUMO

Bone diseases represent an increasing health burden worldwide, and basic research remains necessary to better understand the complexity of these pathologies and to improve and expand existing prevention and treatment approaches. In the present study, 216 bone samples from the caput femoris and collum femoris of 108 patients with degenerative or dysplastic coxarthrosis, hip fracture, or osteonecrosis were evaluated for the proportion of trabecular bone (TB) and expression of parathyroid hormone (PTH) type 1 receptor (PTH1R), osteoprotegerin (OPG), and receptor activator of nuclear factor kappa-B ligand (RANKL). Serum levels of PTH, OPG, soluble RANKL (sRANKL), alkaline phosphatase (AP), osteocalcin, total procollagen type-1 intact N-terminal propeptide (TP1NP), tartrate-resistant acid phosphatase type 5b (TRAP5b), sclerostin, and C-telopeptide of type-1 collagen (ICTP) were also determined. Age was positively correlated with serum levels of PTH, OPG, and sclerostin but negatively associated with TB and sRANKL. Women exhibited less TB, lower sclerostin and ICTP, and higher TRAP5b. Impaired kidney function was associated with shorter bone decalcification time, less TB, lower sRANKL, and higher serum PTH, OPG, and sclerostin. Furthermore, correlations were observed between bone PTH1R and OPG expression and between serum PTH, OPG, and AP. There were also positive correlations between serum OPG and TP1NP; serum OPG and sclerostin; serum AP, osteocalcin, and TRAP5b; and serum sclerostin and ICTP. Serum OPG was negatively associated with sRANKL. In summary, clear relationships between specific bone metabolism markers were observed, and distinct influences of age, sex, and kidney function, thus underscoring their suitability as diagnostic or prognostic markers.


Assuntos
Fraturas do Quadril/patologia , Osteoartrite do Quadril/patologia , Osteonecrose/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Osso Esponjoso/metabolismo , Osso Esponjoso/patologia , Feminino , Fraturas do Quadril/sangue , Fraturas do Quadril/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite do Quadril/sangue , Osteoartrite do Quadril/metabolismo , Osteocalcina/sangue , Osteonecrose/sangue , Osteonecrose/metabolismo , Osteoprotegerina/sangue , Hormônio Paratireóideo/sangue , Ligante RANK/sangue
5.
Life Sci ; 237: 116890, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31606379

RESUMO

AIMS: Telmisartan (TEL), an angiotensin II type I receptor blocker and PPARγ partial agonist, has been used for to treat hypertension. It is known that PPARγ activation induces bone loss. Therefore, we evaluate the effects of telmisartan on PPARγ protein expression, biomechanics, density and bone microarchitecture of femurs and lumbar vertebrae in SHR ovariectomized animals, a model of hypertension in which preexisting bone impairment has been demonstrated. MAIN METHODS: SHR females (3 months old) were distributed into four groups: sham (S), sham + TEL (ST), OVX (C) and OVX + TEL (CT). TEL (5 mg/kg/day) or vehicle were administered according to the groups. After the protocol, blood pressure was measured and density, microarchitecture and biomechanics of bone were analyzed. Western blotting analysis was performed to evaluate PPARγ protein expression in the bones. KEY FINDINGS: Castration induced a deleterious effect on mineral density and trabecular parameters, with telmisartan enhancing such effects. Telmisartan increased PPARγ levels, which were at their highest when the treatment was combined with castration. As to biomechanical properties, telmisartan reduced the stiffness in the castration group (CT vs. S or C group), as well as resilience and failure load in ST group (vs. all others groups). SIGNIFICANCE: These results demonstrated that telmisartan compromised bone density and microarchitecture in animals that shows preexisting osteoporotic bone disorders, probably via mechanisms associated with increased PPARγ. If this translates to humans, a need for greater caution in the use of telmisartan by patients that have preexisting bone problems, as in the postmenopausal period, may be in order.


Assuntos
Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacologia , Doenças Ósseas/tratamento farmacológico , Osso Esponjoso/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Osteoporose/tratamento farmacológico , PPAR gama/metabolismo , Telmisartan/farmacologia , Animais , Densidade Óssea/efeitos dos fármacos , Doenças Ósseas/metabolismo , Doenças Ósseas/fisiopatologia , Osso Esponjoso/diagnóstico por imagem , Osso Esponjoso/patologia , Feminino , Osteoporose/metabolismo , Osteoporose/fisiopatologia , PPAR gama/genética , Ratos , Ratos Endogâmicos SHR , Tomografia Computadorizada por Raios X
6.
Biomed Res Int ; 2019: 8043510, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31428646

RESUMO

The aim was to analyze histologically the bone repair in a mandibular osteotomy model with different gaps between the segments. Nine male rabbits who underwent osteotomies on the mandibular body were fixed with a 1.5 system plate and no bone graft; group 1 (2 mm gap between segments), group 2 (5 mm gap between segments), and group 3 (8 mm gap between segments) were included. After 8 weeks they were euthanized and the sample was processed for histological analysis. Group 1 showed advanced bone repair with cartilaginous tissue and cancellous bone, showing osteoblasts and type III collagenous fibers. In group 2, a more delayed ossification was observed, with an extensive area of peripheral ossifying cartilage and chondrocytes in greater number at the center of the defect; group 3 showed no evidence of ossification with fibrous tissue, a very low level of chondrocytes, and some bone sequestrate. We can conclude that, in this animal model, 2 or 5 mm gap in the osteotomy could be repaired as bone when fixation is used. The size of the gap is an important factor for the use of bone grafts considering endochondral ossification. This model can be used for graft analysis and related technologies.


Assuntos
Placas Ósseas , Transplante Ósseo , Mandíbula , Osteotomia Mandibular , Osteoblastos , Osteogênese , Aloenxertos , Animais , Osso Esponjoso/metabolismo , Osso Esponjoso/patologia , Osso Esponjoso/cirurgia , Humanos , Masculino , Mandíbula/metabolismo , Mandíbula/patologia , Mandíbula/cirurgia , Osteoblastos/metabolismo , Osteoblastos/patologia , Coelhos
7.
Biomed Res Int ; 2019: 9232813, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31143778

RESUMO

If conservative treatment of osteoporotic vertebral compression fractures fails, vertebro- or kyphoplasty is indicated. Usually, polymethylmethacrylate cement (PMMA) is applied coming along with many disadvantageous features. Aluminum-free glass-polyalkenoate cement (GPC) appears to be a benefit alternative material. This study aimed at comparing the mean stress values in human vertebrae after kyphoplasty with PMMA and GPC (IlluminOss™) at hand of a finite element analysis. Three models were created performing kyphoplasty using PMMA or IlluminOss™, respectively, at two native, human lumbar vertebrae (L4) while one remains intact. Finite element analysis was performed using CT-scans of every vertebra. Moreover the PMMA-treated vertebra was used as a model as analyses were executed using material data of PMMA and of GPC. The unimpaired, spongious bone showed potentials of 0.25 MPa maximally. After augmentation stress levels showed fivefold increase, rising from externally to internally, revealing stress peaks at the ventral border of the spinal canal. At central areas of cement 1 MPa is measured in both types of cement. Around these central areas the von Mises stress decreased about 25-50% (0.5-0.75 MPa). If workload of 500 N was applied, the stress appeared to be more centralized at the IlluminOss™-model, similar to the unimpaired. Considering the endplates the GPC model also closely resembles the unimpaired. Comparing the PMMA-treated vertebral body and the GPC-simulation, there is an obvious difference. While the PMMA-treated model showed a central stress peak of 5 MPa, the GPC-simulation of the same vertebral body presents lower stress of 1.2-2.5 MPa. Finite element analysis showed that IlluminOss™ (GPC), used in kyphoplasty of vertebral bodies, creates lower level stress and strain compared to standardly used PMMA, leading to lower stress concentrations on the cranial and caudal vertebral surface especially. GPC appears to own advantageous biological and clinical relevant features.


Assuntos
Cimentos para Ossos/uso terapêutico , Análise de Elementos Finitos , Cifoplastia , Fraturas por Osteoporose/cirurgia , Fraturas da Coluna Vertebral/cirurgia , Idoso , Idoso de 80 Anos ou mais , Osso Esponjoso/patologia , Osso Cortical/cirurgia , Feminino , Cimentos de Ionômeros de Vidro/química , Humanos , Masculino , Polimetil Metacrilato/química , Estresse Mecânico
8.
Biomed Pharmacother ; 115: 108916, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31054506

RESUMO

Lipopolysaccharide (LPS) can induce bone loss by stimulating osteoclast formation. Colony-stimulating factor 1 receptor (CSF 1R) inhibitors have great potential for the treatment of rheumatoid arthritis and tumor-related bone erosion. However, its role in LPS-induced bone loss is still not clarified. In this study, we observed the effects of CSF 1R inhibitor, PLX3397, on LPS-induced bone damage in an animal model. The models were established by LPS administration in male Sprague-Dawley rats. PLX3397 (30 mg/kg body weight) was given by oral gavage. MicroCT analysis, biomechanical properties, biomarker assay, histological examination, and mRNA expression of osteoclast differentiation-related genes (Traf6, Fra1, c-fos and NFATc1) were performed on the 8th week. LPS induced bone loss was shown as the decrease in bone volume fraction and trabecular number and increase in trabecular separation (p < 0.05). LPS exposure also markedly decreased the bone biomechanical properties. PLX3397 significantly abolished the LPS-induced bone microstructure damage (p < 0.05) and loss of biomechanical properties. PLX3397 also inhibited the increases of serum tartrate-resistant acid phosphatase 5b level enhanced by LPS (p < 0.05). PLX3397 attenuated the high expression of Traf6, Fra1, c-fos and NFATc1 stimulated by LPS. Our data demonstrated that PLX3397, a type of CSF 1R inhibitor, can suppress LPS-induced bone loss via the inhibition osteoclast formation.


Assuntos
Aminopiridinas/farmacologia , Reabsorção Óssea/prevenção & controle , Osteoclastos/efeitos dos fármacos , Osteoporose/prevenção & controle , Pirróis/farmacologia , Receptor de Fator Estimulador de Colônias de Macrófagos/antagonistas & inibidores , Animais , Fenômenos Biomecânicos , Densidade Óssea/efeitos dos fármacos , Reabsorção Óssea/metabolismo , Reabsorção Óssea/patologia , Osso Esponjoso/efeitos dos fármacos , Osso Esponjoso/metabolismo , Osso Esponjoso/patologia , Modelos Animais de Doenças , Lipopolissacarídeos/farmacologia , Masculino , Osteoclastos/metabolismo , Osteoclastos/patologia , Osteoporose/induzido quimicamente , Osteoporose/metabolismo , Osteoporose/patologia , Ratos Sprague-Dawley , Tíbia/efeitos dos fármacos , Tíbia/metabolismo , Tíbia/patologia
9.
J Bone Miner Metab ; 37(5): 768-772, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31079208

RESUMO

Subchondral insufficiency fractures of the femoral head are generally considered to be osteoporosis-related fragility fractures. There have been reports of microfractures being found in subchondral bone on pathological examination. However, the mechanism of these microfractures is not known. In this report, we describe a patient with osteogenesis imperfecta who developed a subchondral insufficiency fracture of the femoral head after a fall that had resulted in a subcapital femoral neck fracture. Bipolar hemiarthroplasty was performed, and bone at the femoral head and neck was sampled for pathophysiological examination. Hematoxylin and eosin staining revealed microfractures and microcallus in the subchondral bone in the femoral head, indicating healing of a subchondral insufficiency fracture before the subcapital femoral neck fracture. Moreover, decreased bone volume and accumulated microdamage were observed in the subchondral bone but not in the cancellous bone in the femoral neck. These findings suggest that subchondral insufficiency fracture of the femoral head is a stress fracture caused by accumulation of microdamage in fragile subchondral bone.


Assuntos
Cabeça do Fêmur/lesões , Fraturas de Estresse/etiologia , Fraturas do Quadril/etiologia , Osteogênese Imperfeita/complicações , Adulto , Osso Esponjoso/patologia , Cabeça do Fêmur/diagnóstico por imagem , Cabeça do Fêmur/patologia , Colo do Fêmur/diagnóstico por imagem , Colo do Fêmur/patologia , Humanos , Masculino , Tamanho do Órgão , Osteogênese Imperfeita/diagnóstico por imagem
10.
J Orthop Res ; 37(8): 1784-1789, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30977552

RESUMO

Legg-Calve-Perthes disease is characterized by the capital femoral epiphyseal collapse, which occurs more reliably in the anterior quadrant than the more weight-bearing lateral quadrant. The purpose of this study was to determine whether there is a vascular or microstructural predisposition for anterior femoral epiphyseal collapse in Perthes disease. Thirty-two cadaveric proximal femoral epiphyses from 17 subjects (age 4-14 years old) underwent micro-computed tomography at 10-µm resolution. Each quadrant was analyzed for four markers of trabecular architecture: bone volume fraction (BV/TV), trabecular thickness, trabecular separation (TbSp), and trabecular number (TbN). Vascular channels were then mapped in each quadrant, identified by correlating surface topography with cross-sectional imaging. One-way analysis of variance revealed an overall difference between quadrants (p < 0.001) in BV/TV, TbN, and TbSp. However, post hoc analysis revealed there was no significant difference between the anterior and lateral quadrants for any of the four markers of trabecular architecture. Vascular channel mapping illustrated a predominance of vessels in the posterior half of the epiphysis compared to the anterior half (8.7 ± 4.0 vs. 3.4 ± 3.1 vascular channels, p < 0.001). The lack of microstructural differences between the anterior and lateral quadrants, and the predominance of vascular channels in the posterior half of the epiphysis with posteriorly-based medial femoral circumflex and ligamentum teres vessels suggests that the anterior femoral epiphysis may be a relative vascular watershed region, which predisposes it to collapse after the vascular insult of Perthes disease. Clinical significance: Improved understanding of the pathophysiology of anterior femoral epiphyseal collapse may inform future treatments aimed at revascularization. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1784-1789, 2019.


Assuntos
Osso Esponjoso/patologia , Fêmur/patologia , Doença de Legg-Calve-Perthes/patologia , Adolescente , Osso Esponjoso/irrigação sanguínea , Osso Esponjoso/diagnóstico por imagem , Criança , Pré-Escolar , Epífises/irrigação sanguínea , Epífises/diagnóstico por imagem , Epífises/patologia , Feminino , Fêmur/irrigação sanguínea , Fêmur/diagnóstico por imagem , Humanos , Doença de Legg-Calve-Perthes/diagnóstico por imagem , Masculino , Microtomografia por Raio-X
11.
Int J Mol Sci ; 20(8)2019 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-31027235

RESUMO

Chronic kidney disease-mineral bone disorder (CKD-MBD), comprising mineral, hormonal, and bone metabolic imbalance, is a major CKD-related issue; it causes osteoporosis prevalence in CKD patients. Osteocyte-derived sclerostin inhibits the osteogenic Wnt/ß-catenin signaling pathway; its levels rise when kidney function declines. Exercise modulates the physiological functions of osteocytes, potentially altering sclerostin production. It may aid bone and mineral electrolyte homeostasis in CKD. Mild CKD was induced in rats by partial nephrectomy. They were divided into: sham (no CKD), CKD, and CKD + exercise (8 weeks of treadmill running) groups. Micro-CT scanning demonstrated that the CKD + exercise-group rats had a higher bone mineral density (BMD) of the spine and femoral metaphysis and higher femoral trabecular bone volume than the CKD-group rats. Bone formation rates were not significantly different. The CKD + exercise-group rats had lower serum sclerostin (157.1 ± 21.1 vs 309 ± 38.1 pg/mL, p < 0.05) and CTX-1 (bone resorption marker) levels. Immunohistochemistry revealed higher tibial ß-catenin concentrations in the CKD + exercise-group rats. Serum FGF-23, intact parathyroid hormone (iPTH), alkaline phosphatase (ALP), calcium, and phosphate levels showed no significant differences between these groups. Thus, exercise improves BMD and bone microstructure in mild CKD by inhibiting sclerostin production, but does not alter serum minerals.


Assuntos
Proteínas Morfogenéticas Ósseas/biossíntese , Osteoporose/complicações , Osteoporose/prevenção & controle , Condicionamento Físico Animal , Insuficiência Renal Crônica/complicações , Animais , Biomarcadores/sangue , Biomarcadores/urina , Densidade Óssea , Proteínas Morfogenéticas Ósseas/sangue , Proteínas Morfogenéticas Ósseas/metabolismo , Reabsorção Óssea/sangue , Reabsorção Óssea/patologia , Reabsorção Óssea/fisiopatologia , Reabsorção Óssea/urina , Osso Esponjoso/diagnóstico por imagem , Osso Esponjoso/patologia , Marcadores Genéticos , Rim/patologia , Rim/fisiopatologia , Masculino , Tamanho do Órgão , Osteócitos/metabolismo , Osteoporose/sangue , Osteoporose/urina , Ratos Sprague-Dawley , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/fisiopatologia , Insuficiência Renal Crônica/urina , Tíbia/patologia , beta Catenina/metabolismo
12.
J Orthop Res ; 37(5): 1153-1163, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30839119

RESUMO

Reduced mechanical loading can lead to disuse osteoporosis, resulting in bone fragility. Disuse models report macroscopic bone loss due to muscle inactivity and immobilization, yet only recently has there been quantification of the effects of disuse on the vascular pores and osteocyte network, which are believed to play an important role in mechanotransduction via interstitial fluid flow. The goal of this study was to perform a high-resolution analysis of the effects of muscle inactivity on intracortical porosity and osteocyte lacunar density in skeletally mature rats. Muscle paralysis was induced in 20-week-old female Sprague Dawley rats by injection of botulinum neurotoxin. Rats were injected in the right hindlimb muscles with either Botox (BTX, n = 8) or saline solution (CTRL, n = 8), with a third group used as baseline controls (n = 8). Four weeks after injection, Botox caused a ∼60% reduction in hindlimb muscle mass. High-resolution micro-CT analysis showed that Botox-induced muscle paralysis increased vascular canal porosity and reduced osteocyte lacunar density within the tibial metaphysis cortex. Cortical thickness and other areal properties were diminished in the proximal tibial metaphysis, whereas no differences were found in the mid-diaphysis. Within the BTX group, the injected limbs showed a lower cancellous bone volume fraction relative to the contralateral limb. These results indicate that diminished muscle activity alters the vascular canal porosity and osteocyte lacunar density in cortical bone, which could alter interstitial fluid flow, affecting molecular transport and the transmission of mechanical signals to osteocytes. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.


Assuntos
Osso Esponjoso/patologia , Osso Cortical/patologia , Paralisia/patologia , Comportamento Sedentário , Animais , Toxinas Botulínicas Tipo A , Osso Esponjoso/diagnóstico por imagem , Osso Cortical/diagnóstico por imagem , Feminino , Marcha , Imageamento Tridimensional , Osteócitos , Paralisia/fisiopatologia , Porosidade , Distribuição Aleatória , Ratos Sprague-Dawley , Microtomografia por Raio-X
13.
PLoS One ; 14(3): e0213781, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30921346

RESUMO

During mammalian pregnancy and lactation, the maternal demand for calcium is increased to satisfy fetus and newborn skeletal growth. In addition to the dietary intake, females use the calcium contained in their bones to supply this increased demand, leading to a decrease in maternal bone mineral content. In reproductive insectivorous female bats, bone loss has been described as a physiological cost of reproduction, due to the reported increased risk of bone fracture. This physiological cost may be the mechanism underlying the conflict between increasing litter size and maintaining wing skeletal integrity, which would help to explain the small litter size of most bat species. If bone loss is a linking cost between reproduction and survival in bats, and most bat species have small litter sizes, one would expect to find a loss of bone and an increasing probability of bone fracture during pregnancy and lactation in other non-insectivorous bats. In this study, we tested for the existence of this cost in the Great-fruit eating bat, Artibeus lituratus. We analyzed trabecular structure, bone strength and bone mineral content for the humerus bone, hypothesizing that bone loss during reproduction in females would increase the risk of fracture. Our results showed a decrease of 22-31% in bone trabecular area in lactating females, rapidly compensated following weaning. Bone strength did not differ among reproductive and non-reproductive groups and seems to be more influenced by bone organic components rather than mineral contents. Since we observed bone loss during reproduction yet the humerus strength seems to be unaffected, we suggest that bone loss may not represent a physiological cost during reproduction for this frugivorous bat.


Assuntos
Osso Esponjoso/metabolismo , Quirópteros/fisiologia , Reprodução/fisiologia , Animais , Peso Corporal , Densidade Óssea , Osso Esponjoso/química , Osso Esponjoso/patologia , Quirópteros/crescimento & desenvolvimento , Força Compressiva , Feminino , Lactação , Gravidez
14.
J Bone Miner Metab ; 37(5): 880-885, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30701320

RESUMO

In end-stage osteoarthritis (OA) of the hip, the effect of bone metabolism with and without cartilage is unclear. In this study, we aimed to investigate histomorphology and microdamage in the subchondral bone of the femoral head in areas with and without articular cartilage in patients with end-stage OA. Nineteen femoral heads were evaluated in 10 women who underwent total hip arthroplasty for OA and in nine cadaveric controls (CNT). Chondral thickness and subchondral bone plate thickness (SBP.Th) were measured in 5-mm-wide areas where cartilage was lost (area A) or preserved (area B) in OA and in corresponding areas in the load-bearing portion of the femoral head in the CNT. Histomorphometry and microdamage in 5 × 5-mm areas of cancellous bone were assessed. SBP.Th and bone volume were significantly greater in area A than in area B or in the CNT. Osteoid volume was significantly greater in area A than in area B or in the CNT. There was no significant difference in eroded surface between area A and CNT. Microcrack density was significantly greater in area A than in area B or in the CNT. Although accumulation of microdamage was caused by concentration of stress on the subchondral bone in the cartilage loss area in end-stage OA, remodeling for microdamage repairing mechanism was not enhanced. It was considered that the subchondral cancellous bone volume was increased because of modeling, not remodeling, by stress concentration due to articular cartilage loss.


Assuntos
Cabeça do Fêmur/patologia , Quadril/patologia , Osteoartrite/patologia , Idoso , Idoso de 80 Anos ou mais , Cadáver , Osso Esponjoso/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
15.
Osteoporos Int ; 30(6): 1195-1204, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30788527

RESUMO

Liver cirrhosis leads to bone loss. To date, information on bone quality (three-dimensional microarchitecture) and, thus, bone strength is scarce. We observed decreased bone quality at both assessed sites, independent of disease severity. Therefore, all patients should undergo early-stage screening for osteoporosis. INTRODUCTION: Recent studies found low bone mineral density in cirrhosis, but data on bone microstructure are scarce. This study assessed weight-bearing and non-weight-bearing bones in patients with cirrhosis and healthy controls. The primary objective was to evaluate trabecular and cortical microarchitecture. METHODS: This was a single-center study in patients with recently diagnosed hepatic cirrhosis. Thirty-two patients and 32 controls participated in this study. After determining the type of cirrhosis, the parameters of bone microarchitecture were assessed by high-resolution peripheral quantitative computed tomography. RESULTS: Both cortical and trabecular microarchitectures showed significant alterations. At the radius, trabecular bone volume fraction was 17% lower (corrected p = 0.028), and, at the tibia, differences were slightly more pronounced. Trabecular bone volume fraction was 19% lower (p = 0.024), cortical bone mineral density 7% (p = 0.007), and cortical thickness 28% (p = 0.001), while cortical porosity was 32% higher (p = 0.023), compared to controls. Areal bone mineral density was lower (lumbar spine - 13%, total hip - 11%, total body - 9%, radius - 17%, and calcaneus - 26%). There was no correlation between disease severity and microarchitecture. Areal bone mineral density (aBMD) measured by dual-energy X-ray absorptiometry (DXA) correlated well with parameters of cortical and trabecular microarchitecture. CONCLUSIONS: Hepatic cirrhosis deteriorates both trabecular and cortical microarchitecture, regardless of disease severity. Areal bone mineral density is diminished at all sites as a sign of generalized affection. In patients with hepatic cirrhosis, regardless of its origin or disease severity, aBMD measurements are an appropriate tool for osteologic screening.


Assuntos
Remodelação Óssea/fisiologia , Cirrose Hepática/patologia , Cirrose Hepática/fisiopatologia , Rádio (Anatomia)/patologia , Tíbia/patologia , Idoso , Biomarcadores/sangue , Densidade Óssea , Osso Esponjoso/diagnóstico por imagem , Osso Esponjoso/patologia , Estudos de Casos e Controles , Osso Cortical/diagnóstico por imagem , Osso Cortical/patologia , Feminino , Humanos , Cirrose Hepática/diagnóstico por imagem , Cirrose Hepática Alcoólica/diagnóstico por imagem , Cirrose Hepática Alcoólica/patologia , Cirrose Hepática Alcoólica/fisiopatologia , Masculino , Pessoa de Meia-Idade , Porosidade , Rádio (Anatomia)/diagnóstico por imagem , Tíbia/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Suporte de Carga/fisiologia
16.
J Int Med Res ; 47(4): 1493-1503, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30628519

RESUMO

OBJECTIVE: To analyze the performance of sequential naïve pinhole bone scan (nPBS) and gamma correction pinhole bone scan (GCPBS), reinforced by ImageJ densitometry and pixelized microfracture measurement, for making specific diagnoses of bone marrow edema (BME), bone marrow hemorrhage (BMH), and trabecular microfractures (TMF). METHODS: We prospectively examined BME, BMH, TMF, and normal trabeculae in 10 patients using sequential nPBS and GCPBS. The intensity of 99mtechnetium-hydroxydiphosphonate (99mTc-HDP) uptake was measured using a pixelized method and calculated using ImageJ densitometry in terms of arbitrary units (AU). This overall method was termed a visuospatial-mathematic assay (VSMA). We analyzed the ability of the calculated AU values to discriminate between the four states using GraphPad Prism software, with reference to previous morphological data. RESULTS: The calculated values were categorized as ≤50 AU for normal trabecula, 51-100 AU for BME, 101-150 AU for BMH, and ≥151 AU for TMF. The difference in uptake between normal trabecula and BME was significant and the differences among BME, BMH, and TMF were highly significant. CONCLUSION: VSMA is a useful technique for refining objective individual diagnoses and for differentiating and quantitating BME, BMH, and TMF.


Assuntos
Doenças da Medula Óssea/diagnóstico , Osso Esponjoso/patologia , Edema/diagnóstico , Fraturas Ósseas/diagnóstico , Raios gama , Hemorragia/diagnóstico , Adolescente , Adulto , Idoso , Diagnóstico Diferencial , Difosfonatos , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Compostos de Organotecnécio , Estudos Prospectivos , Adulto Jovem
17.
Osteoporos Int ; 30(2): 277-285, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30488274

RESUMO

Bone modulus from patients with osteoporosis treated with bisphosphonates for 1 to 20 years was analyzed. Modulus increases during the first 6 years of treatment and remains unchanged thereafter. INTRODUCTION: Bisphosphonates are widely used for treating osteoporosis, but the relationship between treatment duration and bone quality is unclear. Since material properties partially determine bone quality, the present study quantified the relationship between human bone modulus and hardness with bisphosphonate treatment duration. METHODS: Iliac crest bone samples from a consecutive case series of 86 osteoporotic Caucasian women continuously treated with oral bisphosphonates for 1.1-20 years were histologically evaluated to assess bone turnover and then tested using nanoindentation. Young's modulus and hardness were measured and related to bisphosphonate treatment duration by statistical modeling. RESULTS: All bone samples had low bone turnover. Statistical models showed that with increasing bisphosphonate treatment duration, modulus and hardness increased, peaked, and plateaued. These models used quadratic terms to model modulus increases from 1 to 6 years of bisphosphonate treatment and linear terms to model modulus plateaus from 6 to 20 years of treatment. The treatment duration at which the quadratic-linear transition (join point) occurred also depended upon trabecular location. Hardness increased and peaked at 12.4 years of treatment; it remained constant for the next 7.6 years of treatment and was insensitive to trabecular location. CONCLUSIONS: Bone modulus increases with bisphosphonate treatment durations up to 6 years, no additional modulus increases occurred after 6 years of treatment. Although hardness increased, peaked at 12.4 years and remained constant for the next 7.6 years of BP treatment, the clinical relevance of hardness remains unclear.


Assuntos
Osso Esponjoso/efeitos dos fármacos , Difosfonatos/farmacologia , Osteoporose Pós-Menopausa/tratamento farmacológico , Administração Oral , Idoso , Remodelação Óssea/efeitos dos fármacos , Osso Esponjoso/patologia , Osso Esponjoso/fisiopatologia , Estudos Transversais , Difosfonatos/administração & dosagem , Difosfonatos/uso terapêutico , Esquema de Medicação , Módulo de Elasticidade/efeitos dos fármacos , Feminino , Dureza/efeitos dos fármacos , Humanos , Ílio/efeitos dos fármacos , Ílio/patologia , Ílio/fisiopatologia , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/patologia , Osteoporose Pós-Menopausa/fisiopatologia , Fotomicrografia
18.
J Reconstr Microsurg ; 35(2): 108-116, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30099731

RESUMO

BACKGROUND: Indocyanine green (ICG) videoangiography is routinely used to evaluate skin and organ perfusion and to assess patency rates of microvascular anastomoses. This study uses ICG angiography as a novel approach to qualitatively and quantitatively evaluate bone perfusion of microvascular fibula grafts intraoperatively and to assess the effect of fibula segment length and number of osteotomies on bone perfusion. METHODS: All patients planned for mandible reconstruction using a microvascular fibula graft between January 2013 and May 2017 were considered for this study. ICG videoangiography of cancellous bone perfusion was performed using a handheld ICG camera. Videos were analyzed, and a perfusion curve was generated. Peak enhancement, time to peak, slope, and wash-in area under the curve were extracted; rise time, wash-in rate (WiR), and wash-in perfusion index were calculated. Results were statistically analyzed with regard to distal fibula segment length and number of osteotomy sites. RESULTS: Thirty-nine patients (age 59 ± 8 years) were included in the study. Mandible reconstruction was achieved with 1 (n = 15), 2 (n = 13), or 3 (n = 11) fibula segments. The WiR was 6.4 ± 2.3 and 4.4 ± 0.2 before and after proximal osteotomy, respectively. The wash-in perfusion index was 114.2 ± 48.4 before and 84.4 ± 20.0 after proximal osteotomy. Bone perfusion was significantly reduced after additional proximal osteotomies. Both the segment length and number of proximal osteotomies correlated with bone perfusion, with longer segments and fewer osteotomies showing higher perfusion. CONCLUSION: This study demonstrates the feasibility of cancellous bone perfusion analysis using ICG and can serve as a basis for future bone perfusion studies. Additional osteotomies and short segment length negatively affects cancellous bone perfusion of the distal fibula segment in free fibula flaps. The extent to which the observed decrease in arterial inflow to the distal fibula segment affects the further course of healing needs to be addressed in future studies.


Assuntos
Angiografia , Osso Esponjoso/diagnóstico por imagem , Fíbula/transplante , Retalhos de Tecido Biológico/fisiologia , Reconstrução Mandibular/métodos , Perfusão , Idoso , Transplante Ósseo , Osso Esponjoso/patologia , Corantes/administração & dosagem , Estudos de Viabilidade , Feminino , Humanos , Verde de Indocianina/administração & dosagem , Masculino , Pessoa de Meia-Idade , Osseointegração , Osteotomia , Resultado do Tratamento
19.
J Bone Miner Metab ; 37(4): 658-667, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30357566

RESUMO

Antioxidant properties of several nutrients may influence bone metabolism, affording protection against damaging effects caused by oxidative stress. Thus, we hypothesized that lycopene may benefit bone tissue metabolism and functional activity of osteoblastic cells from bone marrow of osteoporotic female rats. Wistar rats were ovariectomized and paired with sham animals. In vitro evaluations were performed after 60 days of surgery, when cells were cultured in osteogenic medium and divided in control (C), ovariectomized (OVX) and ovariectomized + 1 µmol/L lycopene (OVXL) groups. Besides, in vivo studies were carried out to evaluate femur bone remodeling by histological and histomorphometric analyses after daily intake of 10 mg/kg of lycopene for 30 and 60 days after ovariectomy. Cell proliferation was significantly higher in OVX and OVXL groups after 10 days of culture. Alkaline phosphatase activity (ALP) was higher in OVXL group in later periods of cell culture, whereas its in situ detection was higher for this group in all experimental periods; nevertheless, mineralization did not show significant differences among the groups. There was a significant upregulation of genes Sp7, Runx2 and Bsp after 3 days and genes Runx2 and Bglap after 10 days from OVXL when compared to OVX. In vivo results demonstrated that daily intake of 10 mg/kg of lycopene for 60 days decreased bone loss in femur epiphysis in ovariectomized rats by maintaining trabecular bone similar to controls. Data obtained suggest that lycopene might benefit the functional activity of osteoblastic cells from ovariectomized rats, as well as avoid further bone resorption.


Assuntos
Reabsorção Óssea/tratamento farmacológico , Reabsorção Óssea/prevenção & controle , Fêmur/patologia , Licopeno/uso terapêutico , Osteoblastos/metabolismo , Osteoporose/tratamento farmacológico , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Fosfatase Alcalina/metabolismo , Animais , Densidade Óssea/efeitos dos fármacos , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Matriz Óssea/efeitos dos fármacos , Matriz Óssea/metabolismo , Reabsorção Óssea/patologia , Reabsorção Óssea/fisiopatologia , Calcificação Fisiológica/efeitos dos fármacos , Osso Esponjoso/efeitos dos fármacos , Osso Esponjoso/patologia , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Feminino , Fêmur/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Licopeno/farmacologia , Osteoblastos/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Osteoporose/patologia , Osteoporose/fisiopatologia , Ovariectomia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos Wistar
20.
Bone ; 120: 114-124, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30342225

RESUMO

Although it is suggested that chronic obstructive pulmonary disease (COPD) and bone are related, almost all of the pathological mechanisms of COPD-related osteoporosis remain unknown. There is a mouse model showing a deterioration of bone quality after cigarette smoke exposure; however, in smoking exposure models, various factors exist that affect bone metabolism, such as smoking and body weight loss (muscle and fat mass loss). We considered it appropriate to use an elastase-induced emphysema model to exclude factors influencing bone metabolism and to investigate the influence of pulmonary emphysema on bone metabolism. The purpose of this study was to establish a COPD/emphysema-related osteoporosis mouse model by using the elastase-induced emphysema model. The lumbar vertebrae and femurs/tibiae exhibited trabecular bone loss and impaired osteogenic activity in 24-week-old male elastase-induced emphysema model mice. In addition, the model mice showed atrophy of type I muscle fibers without atrophy of type II muscle fibers. We believe that the mice described in this experimental protocol will be accepted as a COPD/emphysema-related osteoporosis mouse model and contribute to further investigations.


Assuntos
Reabsorção Óssea/complicações , Fibras Musculares Esqueléticas/patologia , Osteogênese , Osteoporose/complicações , Doença Pulmonar Obstrutiva Crônica/complicações , Enfisema Pulmonar/induzido quimicamente , Enfisema Pulmonar/complicações , Animais , Atrofia , Biomarcadores/metabolismo , Peso Corporal , Densidade Óssea , Osso e Ossos/metabolismo , Osso e Ossos/patologia , Osso Esponjoso/diagnóstico por imagem , Osso Esponjoso/patologia , Modelos Animais de Doenças , Pulmão/patologia , Masculino , Camundongos Endogâmicos C57BL , Tamanho do Órgão , Elastase Pancreática , Microtomografia por Raio-X
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