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Cadmium (Cd) is toxic to the skeletal system resulting in bone loss and pain. We aimed at determining the effect of chronic Cd exposure on bone density and microarchitecture along with changes in the density of a subset of sensory and sympathetic nerve fibers innervating the developing rat femur. Newborn male Wistar rats were injected daily for 49 days with CdCl2 (1 mg/kg i.p.) or saline solution (control group). At the day of sacrifice, levels of Cd in the right femur, liver and kidney were determined by atomic absorption spectrophotometry. Additionally, microCT followed by immunohistochemical analyses were performed in the left femur. Results showed Cd accumulation in trabecular bone neared levels seen in liver and kidney. Cd concentration in cortical bone was significantly lower versus trabecular bone. MicroCT analysis revealed that Cd-exposed rats had a significant decrease in trabecular bone parameters at the distal femoral metaphysis; however, most of the cortical bone parameters were not significantly affected. Cd-exposed rats showed a significant loss of TH+ sympathetic nerve fibers, but not of CGRP+ sensory nerve fibers, at the level of bone marrow of the femoral diaphysis as compared to control rats. This study shows that Cd negatively affects bone density and microarchitecture of trabecular bone and decreases the density of sympathetic nerve fibers innervating rat femur. Future studies are warranted to determine the toxigenic mechanisms of Cd on sympathetic nerves and how sympathetic denervation influences bone loss in animals exposed to Cd.

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Introdução - As elevadas taxas de mortalidade neonatal e a prevalência de bebês nascidos pequenos para idade gestacional (PIG) ainda apresentadas por regiões de baixa e média renda indicam a necessidade de investigação sobre fatores que influenciam o crescimento fetal. Medidas biométricas fetais

Introduction Elevated rates of neonatal mortality and small-for-gestational-age (SGA) babies in low- and middle-income regions indicate the need to investigate factors associated with fetal growth. Fetal biometric measurements below the 10th percentile for gestational age (GA) reflect failure in achieving growth potential and provide opportunities for prenatal interventions. Objective To investigate factors associated with fetal biometric measurements below the 10th percentile assessed at early third trimester among pregnant women in the MINA-Brazil study. Methods This was a prospective analysis of pregnant women living in the urban area of Cruzeiro do Sul (AC), followed up since the antenatal period. Screening of participants took place from February 2015 to January 2016. A sociodemographic and health history interview was carried out along with two clinical assessments, scheduled between the second and third trimesters of pregnancy, to collect data on lifestyle factors and complications during pregnancy, anthropometric evaluation, blood collection, and ultrasound scan assessing fetal biometric measurements of head circumference (HC), abdominal circumference (AC) and femoral length (FL). Poisson regression models with hierarchical selection of variables were fitted for factors associated with occurrence of fetal measurements below the 10th percentile at early third trimester. Prevalence ratios (PR) and 95% confidence intervals (95%CI) were estimated. Results Among 426 participants (mean age 25 years (SD 6.4) and gestational age 27.8 weeks (SD 1.7)), 11.3%, 8.9% e 9.4% had fetuses with HC, AC, FL below the 10th percentile at early third trimester. Fetal biometric measurements below the 10th percentile were negatively associated with higher maternal education level, which denoted over 50% of protection (HC: PR 0.47, 95%CI 0.28; 0.81; AC: PR 0.48, 95%CI 0.26; 0.87; and FL: PR 0.48, 95%CI 0.27; 0.86). Adjusted for maternal education level, nulliparity (PR 1.94, 95%CI 1.10; 3.43), higher pre-gestational body mass index (BMI) (PR 1.06, 95%CI 1.01; 1.11), and pre-gestational alcohol consumption (PR 1.80, 95%CI 0.98; 3.30) were associated with HC measurements below the 10th percentile. Maternal height (p for trend 0.039) and pre-gestational alcohol consumption (PR 2.55, 95%CI 1.31; 4.96) were also associated with AC measurements below the 10th percentile. Association between higher average screen time per day during antenatal follow-up and FL measurements below the 10th percentile were observed as well (p for trend 0.031). Higher maternal education level, which may provide better material and non-material conditions, seems to protect fetal growth from failure to reach potential fetal size for GA. Positive associations observed with obstetric and antenatal conditions may be mediated by biological factors or gestational dysfunctions to incur in fetal measurements below the 10th percentile. Conclusion The occurrence of fetal biometric measurements below the 10th percentile for GA and their associated factors corroborate pre-pregnancy and antenatal care improvements anchored in equity policies, and for new strategies prior to birth that optimize the window of opportunity in the first thousand days of life.

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Blocking of the growth plate (GP) using plates with screws (tension band plating) is a modern method used to correct deformities and moderate leg length discrepancy in growing children. Determining the duration of temporary bilateral blocking without the occurrence of irreversible changes of GP is of paramount importance important. Methods: Two-month-old Californian breed male rabbits (n=30) were exposed to bilateral blocking of the distal GP of the right femur locking plates with screws for 3, 5, and 7 weeks. The fixators were removed after 5 and 7 weeks in 18 rabbits and 3 weeks after that, animals were sacri!ced. The contralateral limb was used as a control. Histological, histomorphometric, and X-ray analyses were performed. Results: During GP blocking, its height gradually decreased. This decreased was more pronounced after 7 weeks. Destructive changes progressed with an increase in the blocking duration. Three weeks after discontinuation of the bilateral blocking that lasted 5 weeks, the height of the GP signi!cantly increased 1.2 times on the lateral side and 1.9 times on the medial side (p<0.001) compared to the control. When blocking was discontinued after 7 weeks, the structure of the GP was partially restored after 3 weeks, the height of GP signi!cantly increased 1.2 times on the lateral side, and 1.07 times on the medial side (p<0.01) compared to the control. Conclusion: Restoration of the structuralfunctional features of the GP after the removal of the plates depends on the duration of temporary bilateral blocking, which must be taken into account in the clinical setting. (AU)

El bloqueo de la placa de crecimiento (PC) utilizando placas con tornillos (banda de tensión) es un método moderno utilizado para corregir deformidades y alteraciones moderadas en la longitud de las piernas en niños en crecimiento. Es de suma importancia determinar cuál debe ser la duración del bloqueo bilateral temporal sin que ocurran cambios irreversibles en la PC. Métodos: Conejos machos de raza californiana de dos meses de edad (n = 30) fueron expuestos al bloqueo bilateral de la PC distal colocando placas del fémur derecho con tornillos durante 3, 5 y 7 semanas. Los fijadores fueron retirados después de 5 y 7 semanas en 18 de los conejos, y 3 semanas después los animales fueron sacrificados. La extremidad contralateral se utilizó como control. Se realizaron análisis histológicos, histomorfométricos y de rayos X. Resultados: Durante el bloqueo de la PC, su altura disminuyó gradualmente. Esta disminución fue más pronunciada después de 7 semanas. Los cambios destructivos se incrementaron a medida aumentaba la duración del bloqueo. Tres semanas después de la interrupción del bloqueo bilateral que duró 5 semanas, la altura de la PC aumentó significativamente 1.2 veces en el lado lateral y 1.9 veces en el lado medial (p <0.001) en comparación con el control. Conclusión: La restauración de las características funcionales estructurales de la PC después de la extracción de las placas depende de la duración del bloqueo bilateral temporal, lo que debería tenerse en cuenta en el tratamiento clínico de estas alteraciones. (AU)

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The aim of this study was to evaluate the trochlear bone and cartilaginous regeneration of rabbits using the association of PRP, chitosan, and hydroxyapatite. Hole was made in rabbit troches, one hole in each animal remained empty (group C), and one was filled by a combination of PRP, chitosan, and hydroxyapatite (group T). Clinical-orthopedic, radiographic, and histomorphometric evaluations were performed. Clinical-orthopedic evaluation showed lameness of two members of the T group and one member of group C. The radiographic evaluation showed that the T group showed absence of subchondral bone reaction (33%). The presence of moderate subchondral bone reaction was more frequently reported in group C with 67%. Microscopic evaluation revealed a presence of tissue neoformation, composed of connective tissue. Microscopic findings were similar in both groups, with a difference in the amount of neoformed tissue being perceptible, which was confirmed after the morphometric analysis, which revealed a significant difference in the quantity of newly formed tissue at the bone/cartilage/implant interface. The composite base of the association of chitosan, hydroxyapatite, and platelet-rich plasma favored bone and cartilage healing.

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Purpose/Aim: The aim of this study was to evaluate the effects of excess maternal and postnatal thyroxine on chondrocytes and the extracellular matrix (ECM) of growth cartilage. MATERIALS AND METHODS: We used 16 adult female Wistar rats divided into two groups: thyroxine treatment and control. From weaning to 40 days of age, offspring of the treated group (n = 8) received L-thyroxine. Plasma free T4 was measured. Histomorphometric analysis was performed on thyroids and femurs of all offspring. Alcian blue histochemical staining and real-time reverse transcription polymerase chain reaction measurements of gene expression levels of Sox9, Runx2, Aggrecan, Col I, Col II, Alkaline phosphatase, Mmp2, Mmp9, and Bmp2 were performed. Data were analyzed for statistical significance by student's t-test. RESULTS: Excess maternal and postnatal thyroxine reduced the intensity of Alcian blue staining, altered the number of chondrocytes in proliferative and hypertrophic zones in growth cartilage, and reduced the gene expression of Sox9, Mmp2, Mmp9, Col II, and Bmp2 in the growth cartilage of all offspring. Additionally, excess thyroxine altered the gene expression of Runx2, Aggrecan and Col I, and this effect was dependent on age. CONCLUSIONS: Excess thyroxine in neonates suppresses chondrocyte proliferation, stimulates chondrocyte hypertrophy and changes the ECM composition by reducing the amount of proteoglycans and glycosaminoglycans (GAGs). Prolonged exposure to excess thyroxine suppresses chondrocyte activity in general, with a severe reduction in the proteoglycan content of cartilage and the expression of gene transcripts essential for endochondral growth and characteristics of the chondrocyte phenotype.

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This study was developed based on in vivo investigation of microporous granular biomaterials based on calcium phosphates, involving matrices of ß-tricalcium phosphate (ß-TCP), hydroxyapatite (HA), biphasic compositions of both phases and a control group. The physicochemical characterization of materials was carried out by X-Ray diffraction (DRX) and mercury porosimetry. Biodegradability, bioactivity and neoformation processes were investigated by Raman spectroscopy, scanning electron microscopy (SEM) and polarized light conducted on biopsies obtained from in vivo tests for periods of 90 and 180 days. These were performed to evaluate the behavior of granular microporous compositions in relation to bone neoformation. Through the performance obtained from in vivo assays, excellent osseointegration and bone tissue neoformation were observed. The results are encouraging and show that the microporous granular biomaterials of HA, ß-TCP and biphasic compositions show similar results with perfect osseointegration. Architectures simulating a bone structure can make the difference between biomaterials for bone tissue replacement and repair.

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Flaxseed oil is an alpha linolenic acid source important in the growth and body development stage; furthermore, this acid acts on adipose tissue and bone health. The aim of this study was to evaluate body composition, fatty acid composition, hormone profile, retroperitoneal adipocyte area and femur structure of pups at weaning, whose mothers were fed a diet containing flaxseed oil during lactation. After birth, pups were randomly assigned: control (C, n = 12) and flaxseed oil (FO, n = 12), rats whose mothers were treated with diet containing soybean or flaxseed oil. At 21 days, the pups were weaned and body mass, length, body composition, biochemical parameter, leptin, osteoprotegerin, osteocalcin, fatty acids composition, intra-abdominal fat mass and femur structure were analyzed. FO showed (p < 0.05): higher body mass (+12 %) and length (+9 %); body fat mass (g, +45 %); bone mineral density (+8 %), bone mineral content (+55 %) and bone area (+35 %), osteocalcin (+173 %) and osteoprotegerin (+183 %). Arachidonic acid was lower (p < 0.0001), alpha-linolenic and eicosapentaenoic were higher (p < 0.0001). Intra-abdominal fat mass was higher (+25 %), however, the retroperitoneal adipocytes area was lower (-44 %). Femur mass (+10 %), distance between epiphyses (+4 %) and bone mineral density (+13 %) were higher. The study demonstrates that adequate flaxseed oil content during a lactation diet plays an important role in the development of pups.

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The growth of the body and bone mass and the mechanical properties of appendicular bone are impaired in immature rats exposed to different simulated high altitudes (SHA) (1850-5450 m) between the 32nd and the 74th days of postnatal life. Now, we report the effects of exposure to 4100 m on the above cited variables in female rats from infancy (age: 1 month) to adulthood (age: 8 months) to define the occurrence of catch up and to establish whether the effects of altitude are transient or permanent. The ex vivo right femur was mechanically tested in three-point bending. Body weight and length, and structural (loads at yielding and fracture, and stiffness) and architectural (diaphyseal cross-sectional area, cortical area, and cross-sectional moment of inertia) properties were measured at 2, 4, 6, and 8 months of exposure to SHA. The negative influence of hypoxia on all variables was similar at different ages or, in other words, the difference among ages was maintained at any extent of hypoxia. Hypoxia did not affect the elastic modulus, thus suggesting that the mechanical properties of the bone tissue were maintained. Catch up did not occur. The resulting osteopenic bone remained appropriate to its mechanical function during the entire exposure to SHA.

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Both undernutrition and hypoxia exert a negative influence on both growth pattern and bone mechanical properties in developing rats. The present study explored the effects of chronic food restriction on both variables in growing rats exposed to simulated high-altitude hypoxia. Male rats (n 80) aged 28 d were divided into normoxic (Nx) and hypoxic (Hx) groups. Hx rats were exposed to hypobaric air (380 mmHg) in decompression chambers. At T0, Nx and Hx rats were subdivided into four equal subgroups: normoxic control and hypoxic controls, and normoxic growth-restricted and hypoxic growth-restricted received 80 % of the amount of food consumed freely by their respective controls for a 4-week period. Half of these animals were studied at the end of this period (T4). The remaining rats in each group continued under the same environmental conditions, but food was offered ad libitum to explore the type of catch-up growth during 8 weeks. Structural bone properties (strength and stiffness) were evaluated in the right femur midshaft by the mechanical three-point bending test; geometric properties (length, cross-sectional area, cortical mass, bending cross-sectional moment of inertia) and intrinsic properties of the bone tissue (elastic modulus) were measured or derived from appropriate equations. Bone mineralisation was assessed by ash measurement of the left femur. These data indicate that the growth-retarded effects of diminished food intake, induced either by food restriction or hypoxia-related inhibition of appetite, generated the formation of corresponding smaller bones in which subnormal structural and geometric properties were observed. However, they seemed to be appropriate to the body mass of the animals and suggest, therefore, that the bones were not osteopenic. When food restriction was imposed in Hx rats, the combined effects of both variables were additive, inducing a further reduction of bone mass and bone load-carrying capacity. In all cases, the mechanical properties of the mineralised tissue were unaffected. This and the capacity of the treated bones to undergone complete catch-up growth with full restoration of the biomechanical properties suggest that undernutrition, under either Nx or Hx conditions, does not affect bone behaviour because it remains appropriate to its mechanical functions.

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The aim of this study was to evaluate the effects of maternal protein and energy restriction during lactation, analyzing on morphological dimensions whether there was catch-up growth through normative nutrition restored, as well as on mechanical axis of femur of the offspring at adulthood. At parturition, Wistar rat dams were randomly assigned to the following groups: 1) control group (C) - free access to a standard laboratory diet containing 23 % protein, 2) protein-energy restricted group (PER) - free access to an isoenergetic, protein-restricted diet containing 8 % protein, and 3) energy-restricted group (ER) ­ fed with restricted amounts of a standard laboratory diet. At weaning, all pups were separated of dams and received free access to a standard laboratory diet containing 23 % protein until 180 days, when the rats were anesthetized and sacrificed. The dimensions of excised pup femur were measured directly using pre-established anatomical points. Morphometric analysis of the femur (macroscopic) showed that most of the measurements in the ER and PER groups were significantly lower than in the control group, with the greatest reductions occurring in the PER group and several structural abnormalities. Our results show that protein and energy restriction during lactation leads to an incomplete catch-up growth in adulthood. The femur showed significant reduction in most of the parameters in the two treated groups, particularly the PER group, when compared to the control group.

El objetivo de este estudio fue evaluar los efectos de la restricción de la proteína materna y de energía durante la lactancia, y analizar las dimensiones morfológicas si hubo recuperación del crecimiento a través de la nutrición normativa restaurada, así como en el eje mecánico del fémur de la descendencia en la edad adulta. En el parto, las crías de ratas Wistar fueron agrupadas aleatoriamente en los siguientes grupos: 1) control (C) - con acceso libre a una dieta estándar del laboratorio, que contenía 23 % de proteínas; 2) con restricción de proteínas y energía (PER) - acceso libre a una dieta isoenergética, con restricción de proteínas, conteniendo un 8 % de éstas y 3) grupo con restricción de energía, alimentado con restricción en la cantidad de alimento de la dieta estándar del laboratorio (ER). Al destete, todas las crías fueron separadas y recibieron las dietas establecidas hasta los 180 días (d180), luego fueron anestesiadas y sacrificadas. Las mediciones de los fémures de las crías de rata fueron obtenidas por puntos anatómicos preestablecidos. El análisis morfométrico de fémur demostró que la mayoría de las mediciones en los grupos ER y PER eran significativamente menores que las del grupo control, con mayores reducciones en el grupo PER. Nuestros resultados muestran que las restricciones de energía y proteínas durante la lactancia conducen a una recuperación del crecimiento incompleto en la edad adulta. El fémur mostró una reducción significativa en la mayoría de los parámetros en los dos grupos tratados, en particular el grupo de PER, en comparación con el grupo control.

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BACKGROUND: The relationship between maternal body composition and foetal development is unclear. AIM: To determine the relationship between maternal body composition [fat mass (FM) and fat-free mass (FFM)] and foetal growth and birth weight, independent of potential confounding factors. SUBJECTS AND METHODS: This study consisted of 92 women, normal and overweight/obese, recruited from the Instituto Fernandes Figueira in Rio de Janeiro, Brazil. Body composition (FM and FFM) was estimated using bioelectrical impedance. Foetal growth was assessed using serial ultrasound measurements at the second and third trimester and infant's weight and length were measured at birth. Multiple linear regression analyses were used to determine the association between maternal FM and FFM and birth weight adjusted for gestational age (BWt) and change in estimated foetal weight (ΔEFW), controlling for infant gender, maternal serum glucose, energy intake, parity, height and income. RESULTS: Maternal FM, but not FFM, was positively associated with BWt (p = 0.02) and borderline with ΔEFW (p = 0.05). FM expressed as a percentage of body weight (%FM) showed a significant positive association with BWt (p < 0.001) and ΔEFW (p < 0.01). Using backward linear regression analysis, FM was a significant predictor of BWt (p < 0.001) and ΔEFW (p = 0.03), but not change in femur length. CONCLUSION: In this small sample of normal and overweight/obese women, maternal FM at mid-pregnancy is associated with neonatal BW and foetal growth.

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The bone development in lambs is extremely important, as this will reflect in the performance of the animals when they are adults. Bone problems in sheep affect the productivity of animals, increasing mortality rates and infection. Therefore, the evaluation of lambs skeletal development should be taken into account when they are fed different types and concentrations of bulk. There are no studies in the literature that demonstrate this relationship. Twenty Ile de France male lambs were used. They were uncastrated and weaned at 15 kg body weight then distributed in four treatments, with five animals per treatment. The treatments consisted of roughage: concentrate 60:40 (corn silage:concentrate); 60:40 ( sugar cane: concentrate); 40:60 (corn silage: concentrate); 40:60 ( sugar cane:concentrate). For morphometric evaluation, weighing of the femurs was performed and the length the perimeter of the proximal and distal epiphysis and the diaphysis of femurs and bone mineral density of the respective treatments were evaluated. No significant differences in the morphometric and densitometric evaluation was found between different treatments, with the exception of diaphysis bone mineral density, which was significantly (p < 0.05) higher in the treatment with 40% corn silage in relation to the treatment 60% sugar cane. The use of diets containing of corn silage and sugarcane associated withaddition of concentrate maintained the anatomical features. However, the proportion of 40% corn silage and 60%concentrate, showed better diaphysis bone mineral density due to a higher intake of nutrients and minerals present in this diet and consequently a higher energy intake, as well as an increased supply of dietary calcium.

O desenvolvimento ósseo em cordeiros é de extrema importância, levando em consideração que, este irá refletir no desempenho dos animais quando adultos. Problemas ósseos em ovinos acometem a produtividade dos animais, aumentando os índices de mortalidade e infecções. Portanto, a avaliação do desenvolvimento ósseo de cordeiros deve ser levada em consideração, quando estes são alimentados com diferentes tipos e concentrações de volumosos, mesmo porque não existem trabalhos na literatura que demonstrem esta relação. Foram utilizados 20 cordeiros Ile de France machos não castrados, desmamados aos 15 kg de peso corporal, distribuídos em quatro tratamentos, sendo utilizados cinco animais por tratamento, com os tratamentos constituídos por proporções de volumoso:concentrado 60:40 (silagem de milho:concentrado); 60:40 (cana-de-açúcar:concentrado); 40:60 (silagem de milho:concentrado); 40:60 (cana-deaçúcar:concentrado). Para a avaliação morfométrica, foi realizada a pesagem dos fêmures e avaliado o comprimento, o perímetro da epífise proximal e distal, bem como o da diáfise dos fêmures e a densidade mineral óssea dos respectivos tratamentos. Não ocorreram diferenças significativas nas avaliações morfométricas e densitométricas dos fêmures dos cordeiros dos diferentes tratamentos, com exceção da densidade mineral óssea da diáfise, que foi significativamente (p <0,05) maior no tratamento com 40% de silagem de milho em relação ao tratamento com 60% de cana de açúcar. A utilização de dietas contendo silagem de milho e cana-de-açúcar, associados à adição de concentrados manteve as características anatômicas dos ossos dos cordeiros em desenvolvimento. No entanto, a proporção de 40% de silagem demilho e 60% de concentrado, evidenciou uma melhor densidade mineral óssea da diáfise em decorrência de um maior consumo de nutrientes e minerais presentes nesta dieta, consequentemente um maior aporte energético.

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The bone development in lambs is extremely important, as this will reflect in the performance of the animals when they are adults. Bone problems in sheep affect the productivity of animals, increasing mortality rates and infection. Therefore, the evaluation of lambs skeletal development should be taken into account when they are fed different types and concentrations of bulk. There are no studies in the literature that demonstrate this relationship. Twenty Ile de France male lambs were used. They were uncastrated and weaned at 15 kg body weight then distributed in four treatments, with five animals per treatment. The treatments consisted of roughage: concentrate 60:40 (corn silage:concentrate); 60:40 ( sugar cane: concentrate); 40:60 (corn silage: concentrate); 40:60 ( sugar cane:concentrate). For morphometric evaluation, weighing of the femurs was performed and the length the perimeter of the proximal and distal epiphysis and the diaphysis of femurs and bone mineral density of the respective treatments were evaluated. No significant differences in the morphometric and densitometric evaluation was found between different treatments, with the exception of diaphysis bone mineral density, which was significantly (p < 0.05) higher in the treatment with 40% corn silage in relation to the treatment 60% sugar cane. The use of diets containing of corn silage and sugarcane associated withaddition of concentrate maintained the anatomical features. However, the proportion of 40% corn silage and 60%concentrate, showed better diaphysis bone mineral density due to a higher intake of nutrients and minerals present in this diet and consequently a higher energy intake, as well as an increased supply of dietary calcium.(AU)

O desenvolvimento ósseo em cordeiros é de extrema importância, levando em consideração que, este irá refletir no desempenho dos animais quando adultos. Problemas ósseos em ovinos acometem a produtividade dos animais, aumentando os índices de mortalidade e infecções. Portanto, a avaliação do desenvolvimento ósseo de cordeiros deve ser levada em consideração, quando estes são alimentados com diferentes tipos e concentrações de volumosos, mesmo porque não existem trabalhos na literatura que demonstrem esta relação. Foram utilizados 20 cordeiros Ile de France machos não castrados, desmamados aos 15 kg de peso corporal, distribuídos em quatro tratamentos, sendo utilizados cinco animais por tratamento, com os tratamentos constituídos por proporções de volumoso:concentrado 60:40 (silagem de milho:concentrado); 60:40 (cana-de-açúcar:concentrado); 40:60 (silagem de milho:concentrado); 40:60 (cana-deaçúcar:concentrado). Para a avaliação morfométrica, foi realizada a pesagem dos fêmures e avaliado o comprimento, o perímetro da epífise proximal e distal, bem como o da diáfise dos fêmures e a densidade mineral óssea dos respectivos tratamentos. Não ocorreram diferenças significativas nas avaliações morfométricas e densitométricas dos fêmures dos cordeiros dos diferentes tratamentos, com exceção da densidade mineral óssea da diáfise, que foi significativamente (p <0,05) maior no tratamento com 40% de silagem de milho em relação ao tratamento com 60% de cana de açúcar. A utilização de dietas contendo silagem de milho e cana-de-açúcar, associados à adição de concentrados manteve as características anatômicas dos ossos dos cordeiros em desenvolvimento. No entanto, a proporção de 40% de silagem demilho e 60% de concentrado, evidenciou uma melhor densidade mineral óssea da diáfise em decorrência de um maior consumo de nutrientes e minerais presentes nesta dieta, consequentemente um maior aporte energético.(AU)

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BACKGROUND: Bisphosphonates are anticatabolic agents that inhibit bone resorption and are widely used to treat osteoporosis and bone metastases in adults. They are also used in young patients with diseases like osteogenesis imperfecta or juvenile osteoporosis. Bone modeling/remodeling is elevated in growing subjects, and inhibition of osteoclastic activity has been shown to interfere with growth. Thus, our objective was to evaluate the effect of alendronate (ALN) on growing animals. METHODS: Healthy male Wistar rats, aged 1 mo, received ALN or vehicle for 8 wk. Serum levels (calcemia, phosphatemia, and total alkaline phosphatase) were determined. Morphometric (rat: femur and tibia weight and length and hemimandible growth) and histomorphometric parameters (thickness of tibial epiphyseal cartilage and each cartilage zone, interradicular bone volume in the first lower molar, trabeculae volume, percentage of bone and cartilage, and osteoclast number in mandibular condyles) were assessed. RESULTS: ALN caused a significant decrease in femur and tibia length, tibial cartilage thickness, and longitudinal growth of hemimandibles. It increased interradicular bone volume and mandibular condyle trabeculae volume, increasing the percentage of cartilage and osteoclast number. CONCLUSION: These findings indicate that administration of ALN to growing animals alters the endochondral ossification process, and thus alters growth.

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The objective of this study was to determine the ability of bone morphogenetic protein (BMP) and fibroblast growth factor (FGF) to repair large segmental radial bone defects in rabbits. We treated calf cancellous bones with 3 mg/L BMP (Group A), 5 µg/L FGF (Group B), or 3 mg/L BMP plus 5 µg/L FGF (Group C). A bone damage model was established using healthy radii from rabbits. The complexes were implanted in the areas of the bone defects in the radii. After successful transplantation, the rabbits underwent radiographic imaging, and bone graft specimens were detected by histopathology methods. Biomechanical indexes were also assessed in order to observe the healing status of the bone defects. Our results indicated that the repair of bone defects was significantly better in Group C compared to the other 2 groups. Therefore, we concluded that combining BMP and FGF significantly promoted bone defect repair and achieved effects that were superior to the use of BMP alone.

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The osteogenic capacity of biomimetic calcium deficient hydroxyapatite microspheres with and without collagen obtained by emulsification of a calcium phosphate cement paste has been evaluated in an in vivo model, and compared with an injectable calcium phosphate cement with the same composition. The materials were implanted into a 5 mm defect in the femur condyle of rabbits, and bone formation was assessed after 1 and 3 months. The histological analysis revealed that the cements presented cellular activity only in the margins of the material, whereas each one of the individual microspheres was covered with osteogenic cells. Consequently, bone ingrowth was enhanced by the microspheres, with a tenfold increase compared to the cement, which was associated to the higher accessibility for the cells provided by the macroporous network between the microspheres, and the larger surface area available for osteoconduction. No significant differences were found in terms of bone formation associated with the presence of collagen in the materials, although a more extensive erosion of the collagen-containing microspheres was observed.

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BACKGROUND: Nonanatomic anterior cruciate ligament (ACL) reconstruction (ACLR) with double-stranded semitendinosus grafts in children with open physes has been described as a successful surgical technique in short-term follow-up clinical reports. PURPOSE: To evaluate the clinical outcomes of nonanatomic ACLR in children with open physes and a minimum of 15 years' follow-up. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Twelve patients with an average age of 10.7 years (range, 8.3-12.4 years) underwent ACLR between 1991 and 1998. All patients were classified as Tanner development stage 2 or lower. The surgical technique involved transphyseal tibial tunnel drilling and over-the-top (OTT) femoral fixation using a double-stranded graft for all patients. Clinical outcomes were evaluated in terms of the manual Lachman test, pivot-shift test, return to sports activity, and International Knee Documentation Committee (IKDC) score at the end of growth and at a minimum 15-year follow-up (range, 15-22 years). RESULTS: No clinically significant growth disturbance was observed. Ten patients had a grade A IKDC score, and 2 patients had a grade B IKDC score at the end of growth. There was no progression of laxity or modification of knee stability with growth. Three patients (25%) had ACL reruptures during sports activities after growth plate closure. All patients with reruptured ACLs underwent additional reconstructive surgery. CONCLUSION: Anterior cruciate ligament reconstruction using the OTT technique in the femur and the transphyseal technique in the tibia produces good results with regard to growth plate closure but a high failure rate in adulthood.

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Both body weight and somatic muscle forces are the main "mechanical factors" in the determination of bone strength in the "weight-bearing bones". However, other "non-mechanical factors", such as dietary proteins, also exist, which modulate bone physiology. This study was designed to explore the mechanical behavior of the femur in post-weaning female rats stunted by feeding on cornstarch. Forty female rats aged 30 days were fed freely with one of the two diets: control (CD) and experimental (ED). CD was the standard rat laboratory diet, whereas ED was cornstarch supplemented with vitamins and minerals. Control (C) and experimental (E) animals were divided into 4 groups: C40 and E40 rats were given CD and ED, respectively, for 40 days; C105 were fed the CD for 105 days; and E40-105 were given the ED for 40 days and then the CD for the remaining experimental period (65 days). Growth of rats was assessed following Parks' model. The biomechanical structural properties of the right femur middiaphysis were estimated using a 3-point bending test. The geometric properties of both the entire bone and the cross-section were determined. The left femur was ashed and both the Ca mass and the Ca concentration were determined. Rats fed the ED failed to achieve normal weight gain. Complete catch-up was observed at the end of a 65 day period of nutritional rehabilitation. The femoral weight and length were negatively affected by the ED, as were the mid-diaphyseal cross-sectional area, the mineralized cortical area, and the cross-sectional moment of inertia. All of these parameters showed incomplete catch-up. The structural bone mechanical properties indicative of strength and stiffness were seriously negatively affected. Intrinsic material bone properties, as assessed by the modulus of elasticity and the maximal elastic stress, were within normal values. In summary, the experimental bone was weaker than the control and structurally incompetent. The considered bone was smaller than the control one, showing a significant reduction in the cross-sectional area and the moment of inertia. However, material properties as well as the ash fraction and Ca concentration were similar in E and C bones. Therefore, E bone is weaker than the C one because of its smaller bone mass, which appears to have been negatively influenced by the ED in relation to its effects on overall body mass.

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RESUMEN

Introducción: La modificación del eje de un miembro mediante la detención parcial del crecimiento (hemiepifisiodesis), es un procedimiento habitual en la cirugía ortopédica pediátrica. Sin embargo no está bien establecido cuánto afecta este procedimiento al crecimiento final del hueso. El objetivo del presente trabajo fue determinar en forma experimental la inhibición del crecimiento longitudinal producido por una hemiepifisiodesis. Materiales y métodos: Se utilizaron, 10 conejos de 8 semanas de vida, a los que se les colocó una grapa en el fémur distal externo derecho. En la 8ª semana del estudio (16 semanas de vida) se realizó la comparación radiológica e histológica de ambos fémures. Resultados: La longitud final media de los fémures con grapas a las 8 semanas finalizado el experimento fue de 89,6mm (rango 87mm-95mm) versus 95,7mm (rango 91mm-100mm) de los fémures sanos. El porcentaje de inhibición media del crecimiento fisario al final del experimento fue de 6,58% (rango 3.2%-10%). Conclusiones: Se demostró experimentalmente la disminución global de la actividad de la fisis durante la hemiepifisiodesis. Esto debe ser tenido en cuenta cuando indicamos una hemiepifisiodesis unilateral en un niño con una discrepancia previa de longitud.

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RESUMEN

Introducción: La modificación del eje de un miembro mediante la detención parcial del crecimiento (hemiepifisiodesis), es un procedimiento habitual en la cirugía ortopédica pediátrica. Sin embargo no está bien establecido cuánto afecta este procedimiento al crecimiento final del hueso. El objetivo del presente trabajo fue determinar en forma experimental la inhibición del crecimiento longitudinal producido por una hemiepifisiodesis. Materiales y métodos: Se utilizaron, 10 conejos de 8 semanas de vida, a los que se les colocó una grapa en el fémur distal externo derecho. En la 8¬ semana del estudio (16 semanas de vida) se realizó la comparación radiológica e histológica de ambos fémures. Resultados: La longitud final media de los fémures con grapas a las 8 semanas finalizado el experimento fue de 89,6mm (rango 87mm-95mm) versus 95,7mm (rango 91mm-100mm) de los fémures sanos. El porcentaje de inhibición media del crecimiento fisario al final del experimento fue de 6,58% (rango 3.2%-10%). Conclusiones: Se demostró experimentalmente la disminución global de la actividad de la fisis durante la hemiepifisiodesis. Esto debe ser tenido en cuenta cuando indicamos una hemiepifisiodesis unilateral en un niño con una discrepancia previa de longitud

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