Observation of the growth and development of subchondral bone in rat condyles exposed to fluoride at the level of bone microarchitecture / 中华地方病学杂志

Objective:To observe the effect of fluoride on growth and development of bone microstructure of rats condyle subchondral bone (RCSB).Methods:Forty two 3-week-old SD rats (half male and half female) were fed adaptively for 1 week, and 3 females and 3 males were sacrificed and recorded as 0 month. The remaining rats were randomly divided into control group ( n = 18) and fluoride exposed group ( n = 18) according to their body weight (55 - 70 g), half male and half female. The fluoride exposed group was fed with 150 mg/L sodium fluoride (NaF) aqueous solution, and the control group was fed with tap water. The two groups of experimental animals were sacrificed at 3, 5 and 7 month, respectively, 6 rats in each group, half male and half female. The right mandibular condyle was separated, and Micro CT scanning was performed to detect the microstructure parameters of RCSB. Results:In fluoride exposed group (3 month), bone surface/tissue volume (BS/TV), bone surface/bone volume (BS/BV), trabecular thickness (Tb.Th), trabecular number (Tb.N), structure model index (SMI), connectivity, connectivity density (Conn.D) and total porosity of female rats were significantly different from those of male rats ( t = - 5.10, - 5.58, 4.52, - 4.32, - 4.03, - 2.81, - 6.71, - 3.32, P < 0.05). There was no significant difference in each index between female and male rats in fluoride exposed group (5, 7 month, P > 0.05). Conclusion:In chronic fluorine exposure bone environment, the RCSB bone microarchitecture of male and female rats is different with time, showing the tendency of fluoride injury that the bone changes of female rats are slowed and the bone changes of male rats are active.

Utilidad del Trabecular Bone Score combinado con la densitometría ósea en la valoración de una serie 194 pacientes / Usefulness of Trabecular Bone Score in combination with bone densitometry to assess a series of 194 patients / Utilidade do Trabecular Bone Score combinado com densitometria óssea na avaliação de uma série de 194 pacientes

Resumen: Introducción: la mayoría de las fracturas por fragilidad ocurren en rango densitométrico de osteopenia, la escala ósea trabecular (TBS) permite valorar aspectos de la microarquitectura que influyen en la resistencia ósea. Objetivo: describir las características clínicas y los hallazgos de la microarquitectura ósea aplicando TBS combinado con densitometría ósea (DXA) en un grupo de pacientes. Material y métodos: estudio descriptivo, de recolección retrospectiva. Se incluyen los pacientes a los que se les realizó DXA con TBS en el INRU en julio y agosto de 2020. Resultados: se analizaron 194 pacientes, 173 (89%) de sexo femenino y 21 (11%) de sexo masculino. El 36,1% (70 pacientes) en rango de osteopenia, 36,1 (70 pacientes) en rango de osteoporosis. El 32,9% (23 pacientes) con osteopenia y el 47,1% (33 pacientes) con osteoporosis tenían microarquitectura degradada. 76,9% de los pacientes con artritis reumatoidea y 45,8% de los que tenían espondiloartritis presentaban microarquitectura alterada. Conclusiones: el TBS permitió reestratificar el riesgo de fractura en un número importante de pacientes, mostrándose como una herramienta muy útil en la valoración complementaria de la salud ósea.

Summary: Introduction: most fractures that result from bone fragility occur in the osteopenia range The trabecular bone score (TBS) enables the assessment of microarchitecture aspects that impact bone resistance. Objective: to describe the clinical characteristics and findings of bone microarchitecture, by applying TBS and bone densitometry in a group of patients. Method: descriptive study of retrospective collection. Patients who were included in the study underwent a Dual-energy X-ray Absorptiometry (DXA) with TBS at the National Rheumatology Service between July and August, 2020. Results: 94 patients were analysed, 173 (89%) were female and 21 (11%) were male. 36.1% (70 patients) lay in the osteopenia range, 36.1 (70 patients) in the osteoporotic range. 32.9% (23 patients) with osteopenia and 47.1% (33 patients) with osteoporosis evidenced a degraded bone microarchitecture. 76.9 % of patients with rheumatoid arthritis and 45.8 % of patients with spondyloarthritis respectively evidenced altered bone microarchitecture. Conclusions: TBS allowed stratification of fracture risk in a significant number of patients, which may suggest it is a useful tool for complementary assessment of bone health.

Resumo: Introdução: a maioria das fraturas por fragilidade ocorre na faixa densitométrica da osteopenia; o escore de osso trabecular (TBS) permite avaliar aspectos da microarquitetura que influenciam a resistência óssea. Objetivo: descrever as características clínicas e os achados da microarquitetura óssea aplicando TBS combinado com densitometria óssea (DMO) em um grupo de pacientes. Material e métodos: estudo descritivo, retrospectivo, incluindo pacientes que realizaram DXA (absorciometria de raios-X de dupla energia) com TBS no INRU em julho e agosto de 2020. Resultados: foram analisados 194 pacientes, 173 (89%) mulheres e 21 (11%) homens. 36,1% (70 pacientes) na faixa de osteopenia, 36,1 (70 pacientes) na faixa de osteoporose. 32,9% (23 pacientes) com osteopenia e 47,1% (33 pacientes) com osteoporose tinham microarquitetura degradada. Nos pacientes com artrite reumatoide 76,9% e nas espondiloartrite 45,8% apresentaram microarquitetura alterada, respectivamente. Conclusões: a TBS permitiu fazer uma nova estratificação do risco de fratura em um número significativo de pacientes, mostrando-se uma ferramenta muito útil na avaliação complementar da saúde óssea.

Effects of high-fat diet on bone mineral density and microarchitecture in LDLR-/-mice / 中华内分泌代谢杂志

Objective To investigate the effect of high-fat diet on bone calcium content, bone mineral density,and microarchitecture in low density lipoprotein receptor knockout(LDLR-/-) mice. Methods Thirteen LDLR-/- mice aged 11 weeks and 13 sex-age-matched C57BL/6J mice(WT)were divided into WT group with normal diet,WT group with high-fat diet,LDLR-/- group with normal diet,and LDLR-/- group with high-fat diet. All mice were sacrificed at 40 weeks of age and left tibias were harvested to analyze the bone mineral density and bone microarchitecture parameters. The right tibias were sampled for measurement of osteoporogeterin(OPG)and receptor activator of nuclear factor kappa-B ligand(RANKL)mRNA expressions using real-time PCR. Results LDLR-/-and high-fat diet significantly changed bone calcium content, bone microarchitecture parameters, and OPG/RANKL mRNA ratio(P<0.05). Compared with WT mice, LDLR-/-mice with high-fat diet showed a lower bone calcium content,along with correspondingly decreased parameters of bone microarchitecture(P<0.05). Compared with WT mice with normal diet, bone calcium content, tissue bone mineral density, and OPG/RANKL mRNA ratio were decreased in LDLR-/-mice with ordinary diet(P<0.01),while no change of other bone microarchitecture parameters was found. Conclusions High-fat diet results in decreased bone mass and damaged bone microarchitecture in LDLR-/- mice,which may be attributed to the down-regulation of OPG/RANKL mRNA ratio.

Evaluación de score de hueso trabecular (TBS) en pacientes menopáusicas con fracturas y sin ellas / Trabecular bone score evaluation in postmenopausal women with or without fractures

El score de hueso trabecular (TBS, Trabecular Bone Score) es una medición de la textura de los grises derivada de la evaluación del raquis por DXA y proporciona un índice de la microarquitectura ósea. Se ha demostrado que los valores bajos presentan capacidad para predecir fracturas. Nuestro objetivo fue evaluar si existían diferencias entre los valores de TBS de pacientes con fracturas frente a no fracturadas. Materiales y métodos: se revisaron 159 historias clínicas de mujeres menopáusicas que consultaron para evaluación de su salud ósea. Se consideraron los antecedentes autorreferidos de fracturas (Fx), la DMO de raquis, cuello femoral y fémur total y TBS. Resultados: treinta pacientes (18,9%) presentaron fracturas y en ellas se observó menor TBS (con Fx: 1,295±83 vs. sin Fx: 1,366±84, p<0,0001), menor índice de masa corporal (IMC) (con Fx: 23,7±1,9 vs. sin Fx: 25,7±4,2, p=0,02), sin diferencias en la edad (p=0,39), ni en valores de DMO (L1-L4 p=0,11, cuello femoral p=0,20 y fémur total p= 0,12). Muchas de las fracturas ocurrieron en pacientes sin osteoporosis por DXA. Conclusiones: el TBS aumentaría la capacidad de DXA para identificar a mujeres argentinas en riesgo de padecer fracturas sin tener osteoporosis densitométrica. Este es el primer trabajo realizado en la Argentina con medición de TBS. (AU)

Trabecular Bone Score (TBS) is a measure of the grey scale derived from DXA lumbar image and provides information about microarchitecture. It has been shown that low TBS values can predict fractures. Our objective was to evaluate if there are any differences between the TBS values in patients with fractures vs. non-fractures. Materials and methods: We reviewed 159 medical records of menopausal women who consulted for evaluation of their bone health. Self-reported fractures (Fx), spine BMD, femoral neck and total femur and TBS were evaluated. Results: thirty patients (18.9%) presented fractures and they showed lower TBS (with Fx: 1,295±0,083 vs. without Fx: 1,366±0,084, p<0.0001), lower body mass index (BMI) (with Fx: 23.7±1.9 vs. without Fx 25.7±4.2, p=0.02), without differences in ages (p=0.39) or in BMD values (L1-L4 p=0.11, femoral neck p=0.20 and total femur p=0.12). Some fractures occurred in patients without osteoporosis, as determined by DXA. Conclusions: TBS would increase the ability of DXA to identify Argentine women at risk for fractures without densitometric osteoporosis. This is the first work done in Argentina with TBS measurement. (AU)

An experimental study of effect of curcumin on improvementof bone microarchitecture and bone quality inhigh-fat-diet C57BL/6J mice and its association with cathepsin K / 中国药理学通报

Aim To investigate the effect of curcumin against high-fat-diet induced C57BL/6J mice bone changes and the correlation between the expression of cathepsin K and curcumin.Methods Curcumin treated C57BL/6J mice had been on high fat diet for 12 weeks.The HE, Alizarin red S staining and Safranin O/fast green staining of femur were employed to evaluate bone microstructure, bone metabolism and bone development.The expressions of cathepsin K were assessed by Western blot and immunohistochemical staining.Results Histopathological results showed that curcumin could improve the destruction of trabecular bone structure, cartilage development and bone calcification.Biomechanical results proved that curcumin could improve the bone strength of the type 2 diabetic mice induced by high fat.The results of immunohistochemistry and Western blot assay indicated that curcumin could significantly inhibit the expression of cathepsin K in bone tissues of mice.Conclusion Curcumin can increase bone strength, improve bone microstructure, and enhance the degree of bone calcification, which may be achieved by inhibiting the expression of cathepsin K.

Effect of deer bone polypeptides on bone microarchitecture of dexamethasone-induced osteoporosis rats / 中草药

Objective: To investigate the effect of deer bone polypeptides on bone microarchitecture of dexamethasone-induced osteoporosis (GIOP) rats. Methods: The rats were im given dexamethasone for establishing a rat GIOP model. The rats were ig given deer bone polypeptide with different doses for 75 d. The serum biochemical indexes were classic detection. The three-dimensional analysis of the trabecular structure of proximal tibia was conducted by microCT method; The pathological changes in the morphology of distal femur were observed by hematoxylin. Results: Deer bone polypeptides could increase serum Ca2+ and bone-gla-protein (BGP), decrease serum P3+, alkaline phorphatase (ALP), and parathyroid (PTH) in rats with GIOP. Deer bone polypeptide showed a tendency to reduce the serum CT in rats with GIOP, but the decreasing tendency was not statistically significant compared with the blank control group. The trabecula was thin and ruptured, its free ends increased, its number decreased, its spaces were widened, and the destructed space structures increased in rats with GIOP, while the intervention with deer bone polypeptides could significantly improve the above indexes to evaluate the bone microstructure. Conclusion: Deer bone polypeptides can inhibit the glucocorticoids-induced metabolism imbalance of calcium and phosphorus, reduce the serum ALP, increase the serum BGP, and inhibit the bone resorption and bone formation in rats with GIOP. Moreover, deer bone polypeptides can improve pathological changes in the microstructure and protect osteoporosis rats.

Valor clínico del puntaje óseo trabecular calculado a partir de la absorciometría de rayos X de energía dual de columna / Clinical importance of the Trabecular Bone Score obtained from spine dual-energy x-ray absorptiometry

Intrínsecamente, se acepta el hecho de que definir a la osteoporosis solamente sobre la base de la densidad mineral ósea proyectada (DMO mediante DXA) ha llegado a su límite. De hecho, el aspecto multifactorial de esta enfermedad hace que la definición actual de osteoporosis evolucione hacia un modelo de riesgo complejo basado en el Factor de Riesgo Clínico (FRC) y la DMO. El puntaje óseo trabecular (TBS, Trabecular Bone Score) es una nueva medición de escala de grises que se basa en el uso de variogramas experimentales sobre imágenes en proyección 2D, y que permite diferenciar entre dos microarquitecturas tridimensionales (3D) que presentan la misma densidad ósea pero diferentes características trabeculares. El TBS mide la tasa promedio de variación local en escala de grises sobre imágenes de proyección 2D. Este parámetro se obtiene luego del re-análisis de un examen de DXA, y puede compararse con la DMO dado que ambos evalúan la misma región ósea. El valor agregado del TBS respecto de la densitometría mineral ósea para la evaluación del riesgo de fracturas ha sido documentado en estudios transversales, prospectivos y longitudinales. De hecho, se ha hallado que el TBS: 1) es más bajo en mujeres posmenopáusicas con una fractura osteoporótica previa, comparado con mujeres sin fractura pareadas por edad y DMO; 2) brinda un aumento incremental en el odds ratio para fractura de columna cuando se combina con la DMO de columna; 3) es más bajo en mujeres con fracturas (comparado con aquellas sin fracturas), independientemente de si su DMO reúne los criterios para osteoporosis u osteopenia; 4) predice fracturas en forma prospectiva, tal como lo hace la DMO; 5) rescata alrededor de 1/3 de las fracturas clasificadas de manera errónea según la definición de DMO de la OMS para osteoporosis aislada; y 6) se comporta de manera diferente de acuerdo con el tipo de terapia ósea implementada. El objetivo de esta breve revisión consiste en brindar información acerca de los ensayos clínicos actuales referentes al TBS, además de posicionar a este parámetro en la práctica clínica como complemento de la DMO en vista de su actual validación.

Intrinsically it is accepted that defining osteoporosis on the sole basis of projected bone mineral density (BMD by DXA) has reached its limit. Indeed, the multifactorial aspect of this disease means that the current definition of osteoporosis is evolving towards a complex risk model based on Clinical Risk Factor (CRF) and BMD. The Trabecular Bone Score (TBS) is a novel grey-level texture measurement that is based on the use of experimental variograms of 2D projection images, and is able to differentiate between two 3-dimensional (3D) micro-architectures that exhibit the same bone density, but different trabecular characteristics. TBS measures the mean rate of local variation of grey levels in 2D projection images. The TBS is obtained after re-analysis of a DXA exam, and can be compared with BMD, since both evaluate the same region of bone. The added value of the TBS in bone mineral densitometry for fracture risk assessment has been documented in cross-sectional, prospective and longitudinal studies. Indeed, TBS has been found to: 1) be lower in post-menopausal women with a past osteoporotic fracture compared with age- and BMD-matched women without fracture; 2) give an incremental increase in the odds ratio for spine fracture when combined with spine BMD; 3) be lower in women with (versus without) fractures, irrespective of whether their BMD met the criteria for osteoporosis or osteopenia; 4) prospectively predict facture as well as spine BMD; 5) recapture around 1/3 of mis-classified fractures according to the BMD WHO definition of osteoporosis alone, and 6) react differently according to the type of bone therapy. The aim of this short review is to report the current clinical studies as well as to position TBS in clinical routine to complement BMD in the light of its current validation.

O efeito do ácido zoledrônico na microestrutura óssea analisado pela micro-CT em mandíbulas de ratos wistar / Zoledronic acid effect on the bone microarchitecture of the jaw of rats by Micro-CT

Os bisfosfonatos são medicamentos amplamente e efetivamente utilizados para o tratamento de doenças osteolíticas. Entretanto, na cavidade oral, é de particular relevância, pois possuem como efeito adverso a osteonecrose dos maxilares induzida pelo uso de bisfosfonatos. Sua etiopatogenia ainda não é bem estabelecida, os métodos de detecção são insatisfatórios e as terapias recomendadas são por vezes, medidas paliativas e ineficazes. Pouco ainda é sabido sobre o efeito do Ácido Zoledrônico na microestrutura óssea, portanto, propusemo-nos a realizar um estudo em modelo animal que analisasse o trabeculado ósseo da mandíbula através da Micro-CT. Foram utilizados 24 ratos machos (Rattus novergicus, albinus, Wistar), com 12 semanas de vida, divididos em 2 grupos: grupo controle (cloreto de sódio 0,9%) e grupo ácido zoledrônico (ácido zoledrônico 0,6mg/kg). As substâncias foram administradas via intraperitoneal a cada 28 dias em um total de 5 doses. Após 150 dias do início do experimento, foi realizada a eutanásia dos animais e então as amostras foram preparadas e escaneadas (Skyscan 1174) para análise da microestrutura óssea através da Micro- CT. O teste t-student demonstrou diferença estatisticamente significativa (p<0,05) em todos os fatores: volume ósseo, densidade óssea, fator de padrão trabecular, índice de modelo estrutural, espessura trabecular, separação trabecular, porosidade total exceção de número de trabéculas e volume tecidual, demonstrando que há alterações significativas na estrutura trabecular pelo uso de bisfosfonatos. O grupo medicado com ácido zoledrônico comparado ao grupo controle demonstrou trabéculas mais espessas, menos separadas e com menores ligações...

Bisphosphonates are widely and effectively drugs used for the treatment of osteolytic disorders. However, in the oral cavity, this situation is of particular relevance as it can lead to bisphosphonate related osteonecrosis of the jaws. Its etiopathogenesis is still not established, detection methods are unsatisfactory and recommended therapies are sometimes palliative and often ineffective. Little is known about the effect of zoledronic acid on the quality of trabecular bone, therefore, we proposed to conduct a study in an animal model to examine the trabecular bone of the jaw through the Micro-CT. 24 male rats were used (Rattus norvegicus, Albinus, Wistar), with 12 weeks old, divided into 2 groups: control group (sodium chloride 0.9%) and group with zoledronic acid (zoledronic acid 0.6 mg / kg). The substances were administered intraperitoneally every 28 days for a total of 5 doses. After 150 days from the beginning of the experiment, the animals were sacrificed and then the samples were prepared and scanned (Skyscan 1174) for analysis of the bone microstructure through Micro-CT. The "t-student" test demonstrated statistically significant differences (p<0.05) in all factors: bone volume, osseous density, trabecular pattern, structure model index, trabecular thickness, trabecular separation, total porosity except trabecular number and tissue volume, demonstrating that there are significant changes in the trabecular structure of the bisphosphonates. Zoledronic Acid compared to control group shows thicker, less separate and lower connected trabeculae...

The relationship between microstructure of vertebral cancellous bone and fixation strength of pedicle screws / 医用生物力学

Objective By measuring the microstructure parameters of cancellous bone in vertebral bodies with different bone mineral density (BMD) levels, to study the correlation between such parameters and the corresponding maximum pullout strength (MPS) when fixed by pedicle screws, so as to understand if the microstructure parameters are related with screw stability and further to reveal the cause of screw loosening. Methods Based on the BMD detection results, fresh human cadaver spines were stratified into four levels: normal, osteopenia, osteoporosis and severe osteoporosis, according to diagnosis criteria in clinic. The corresponding vertebral specimens were then instrumented with pedicle screws, and screw pullout tests were conducted to measure the MPS of such screws. All the vertebral specimens were collected subsequently, and the cancellous bone cylinders were drilled from the center of each vertebra for micro CT scanning. Microstructure parameters of the vertebral trabecular bone at different BMD levels were obtained to investigate the interrelationships in between, and the relationships between the microstruture parameters and corresponding MPS of pedicle screws with osteoporosis severity were then compared. Results With the decline of BMD from normal to severe osteoporosis level, the corresponding MPS of pedicle screws was significantly declined. With the severity of osteoporosis increasing, the progressive bone volume loss, mechanical incompetence and microstructure deterioration also appeared evidently. Significant differences were found in microstructure parameters at different BMD levels. Strong correlations were extensively observed among BMD, microstructure parameters and MPS of screws. The MPS of pedicle screws was highly correlated with bone volume over total volume (BV/TV), trabecular thickness (Tb.Th) and trabecular separation (Tb.Sp) from micro-CT scanning. Conclusions Significant deterioration would occur in bone tissues with the decline of BMD level, and the MPS of pedicle screws was highly correlated with some microstructure parameters.

Efectos "in vivo" de Metformina sobre las alteraciones de la microarquitectura sea asociadas al Sndrome Metablico inducido por fructosa en ratas / In vivo effects of Metformin on the alterations of bone micro-architecture associated with fructose-induced Metabolic Syndrome in rats

El Sndrome Metablico (SM) se ha asociado recientemente con una disminucin en la densidad mineral sea, y con un aumento en la incidencia de fracturas osteoporticas. Recientemente encontramos que la Metformina por va oral en ratas, promueve la diferenciacin osteognica de clulas progenitoras de mdula sea e incrementa la reparacin de lesiones seas. En este trabajo evaluamos los efectos del SM inducido por Fructosa sobre la microarquitectura sea en ratas, y la modulacin de estos efectos por Metformina administrada en forma oral. Utilizamos ratas Sprague Dawley macho jvenes: C (control sin tratamiento), C+M (100mg/kg/da Metformina en el agua de bebida), F (10 % Fructosa en el agua de bebida) y F+M (Fructosa+Metformina en el agua de bebida). Los tratamientos se continuaron por 3 semanas luego de lo cual se tomaron muestras de sangre, previas al sacrificio de los animales. Se disecaron los fmures para evaluacin histomorfomtrica de la microarquitectura metafisaria por tincin con Hematoxilina-Eosina (H-E). Se observ un incremento en la glucemia y trigliceridemia en el grupo F versus el C, compatible con el desarrollo de SM. El anlisis de las metfisis femorales mostr un aumento en la densidad osteoctica trabecular para el grupo C+M (118 % del control, p<0,05). El tratamiento con Fructosa sola disminuy la densidad osteoctica (79 % del control, p<0,05), mientras que el co-tratamiento Fructosa+Metformina (grupo F+M) revirti parcialmente este descenso (88 % del control). Similarmente, el porcentaje de hueso trabecular en la metfisis femoral aument luego del tratamiento slo con Metformina (129 % respecto del control), se redujo en las ratas tratadas con Fructosa (89 % respecto del control), y fue intermedia en el grupo F+M (94 % respecto del control). Estos resultados muestran que el SM inducido por Fructosa en ratas altera la microarquitectura metafisaria femoral; y que estos efectos deletreos pueden ser parcialmente prevenidos por un tratamiento oral con Metformina.

Several clinical studies have demonstrated that the Metabolic Syndrome (MS) is associated with a decrease in bone mineral density, and with an increased risk for non-vertebral osteoporotic fractures. We have recently found that orally administered Metformin induces osteogenic effects in rats, promoting osteoblastic differentiation of bone marrow progenitor cells and increasing the repair of bone lesions. In the present work we have evaluated the effects of Fructose-induced MS on bone micro-architecture in rats, and the possible modulation of these effects by orally administered Metformin. We utilized young male Sprague-Dawley rats, divided into four groups: C (non-treated controls); C+M (100 mg/kg/day of Metformin in drinking water); F (10 % of Fructose in drinking water); and F+M (Fructose+Metformin in drinking water). After three weeks of all treatments blood samples were taken, after which animals were sacrificed by cervical dislocation under anaesthesia. Femurs were then dissected for evaluation of metaphyseal micro-architecture after Haematoxilin-Eosin staining of 5 μm histological slices of decalcified bone. In particular, osteocytic density and relative trabecular volume were determined. An increase in serum glucose and triglycerides was observed in Fructose-treated rats, in accordance with the development of MS. In rats treated with Metformin alone (group C+M), the analysis of femoral metaphyses showed an increase in trabecular osteocytic density (118 % of control [group C], p<0.05). Treatment with Fructose alone (group F) significantly decreased ostecytic density (79 % of control, p<0.05), while co-treatment with Fructose and Metformin partially reverted this decrease (group F+M, 88 % of control). Similarly, the relative trabecular volume of femoral metaphysic was increased by treatment with Metformin alone (129% of control), was reduced in Fructose-treated rats (89 % of control), and tended to revert back to control values after Fructose-Metformin co-treatment (94 % of control). These results show for the first time that (a) Fructose-induced MS in rats alters their femoral metaphysis micro-architecture; and that (b) these deleterious effects can be partially prevented by orally administered Metformin.

Changes in bone mineral density and microarchitecture with advancing age in the male apolipoprotein E knockout mice / 中华内分泌代谢杂志

Objective To study the changes of microarchitecture, bone mineral density (BMD) , and bone mineral content (BMC) in apolipoprtein E knockout( ApoE-/-) mice. Methods Male ApoE-/- mice at 15, 28, and 40-week of age and sex-age-matched wild-type (WT) mice were involved in the study. The trabecular and cortical bone microarchitecture were assessed by micro-CT( μCT) in the right distal femur. The total body BMD of the left femur was determined by dual-energy X-ray absorptiometry ( DXA). The relationships among BMD, microarchitecture, and BMC were analyzed. Results Compared with WT mice,the advancing age ApoE-/- mice showed an increased volumetric BMD (vBMD), tissue BMD (tBMD) , BMC, bone volume fraction (BV/TV), trabecular number (Tb. N ) , trabecular thickness (Tb. Th) with an decreased bone surface fraction ( BS/BV), trabecular separation (Tb. SP) , and the structure mode index (P <0. 05 ) in the cancellous bone of femur. The cortical bone microarchitecture parameters as inner perimeter, outer perimeter, cortical area, marrow area, total area and moment of inertia were also increased, but cortical BMD, cortical bone mineral content (C. BMC) and cortical thickness retained constant. At the age of 28 weeks,the total body BMD in ApoEE-/- mice revealed higher than WT mice (P<0. 05) and there was no changes in 15 and 40-week-old mice compared with the sex-age-matched controls. vBMD was positively correlated with BMC, BV/TV,Tb. Th, BS/BV, and C. BMC, with the correlation coefficients 0.955,0.944,0. 834,0.923, and 0.903 .respectively, and there was no correlation between vBMD and the other parameters. Conclusions ApoEE-/- mice display an increased bone mass, suggesting that ApoE has an important role in bone remodeling.

Característica de Euler-Poincaré aplicada para identificar baixa densidade óssea a partir de imagens tomográficas de vértebras / The Euler-Poincaré characteristic applied to identify low bone density from vertebral tomographic images

A densidade mineral óssea (DMO) é o exame padrão-ouro para o diagnóstico da osteoporose. No entanto, sabe-se que apenas essa medida não é suficiente para identificar completamente a fragilidade óssea e o conseqüente risco de fratura, tornando-se necessário a investigação da estrutura óssea. OBJETIVOS: Avaliar se a característica de Euler-Poincaré (CEP) para analisar a conectividade do osso trabecular poderia fornecer um suporte adicional na identificação da deterioração da estrutura óssea. MATERIAIS E MÉTODOS: Analisou-se um conjunto de imagens formando disectors, obtidas da tomografia computadorizada de vértebras lombares, a partir dos quais foi estimada a característica Euler-Poincarè.(CEP). Para lidar com o processamento de imagens dos disectors, foi desenvolvido um programa de computador usando o GTK+ para MS-Windows. Os resultados foram comparados com a DMO. RESULTADOS: Verificou-se que a medida da CEP está correlacionada com os resultados obtidos por meio da DMO para as vértebras lombares. Ficou demonstrado também que a área de conectividade das trabéculas que é propagada ao longo dos disectors corrobora para assegurar que os resultados da CEP sejam consistentes com a medida da DMO. CONCLUSÕES: A aplicação da CEP na análise das tomografias vertebrais poderá vir a se constituir num método para avaliar a estrutura óssea trabecular, e sua correlação com a resistência mecânica do osso, sendo necessários porém mais estudos para confirmar esses dados.

The bone mineral density (BMD) is the gold standard test for the diagnosis of osteoporosis. Nevertheless, it is known that only this measurement is not sufficient to completely identify bone fragility and the consequent risk of fracture, becoming necessary the investigation of the bone structure. OBJECTIVES: Evaluate if the Euler-Poincaré characteristic (EPC) for the analysis of the connectivity of the trabecular bone could supply an additional support in identifying the deterioration of the bone structure. MATERIALS AND METHODS: A group of images forming dissectors were analyzed, obtained from the computerized tomography of the lumbar vertebrae, from which the Euler-Poincarè characteristic (EPC) was estimated. To deal with the processing of images of the dissectors, a computer program was developed using the GTK+ for MS-Windows. The results were compared to the BMD. RESULTS: It was verified that the measurement of the EPC is correlated with the results obtained by means of the BMD for the lumbar vertebrae. It was also demonstrated that the area of connectivity of the trabecular that is propagated over the dissectors corroborates to ensure that the results of the EPC are consistent with the BMD measurement. CONCLUSIONS: The application of ECP in the analysis of the vertebral tomographies could constitute a method to evaluate the trabecular bone structure, and its correlation with the mechanical resistance of the bone, however being necessary more studies to confirm this data.