Biomechanical Effects of Angiotensin 1-7 in Diabetes Rats Femur / Efectos Biomecánicos de la Angiotensina 1-7 en el Fémur de Ratas Diabéticas

SUMMARY: It is known that diabetes mellitus has late complications, including microvascular and macrovascular diseases. Diabetes can affect bones through biochemical markers of bone structure, density, and turnover. This study aimed to biomechanically investigate the bone-protective effects of angiotensin 1-7 (Ang 1-7), one of the active peptides in the renin-angiotensin system, in rats with diabetes. Thirty male Wistar albino rats, three months old and weighing 250-300 g, were divided into four groups: diabetes, Ang 1- 7, diabetes plus Ang 1-7, and control. One month later, diabetes developed in rats; the rats were sacrificed, and their right femur was removed. Three-point bending biomechanical tests were performed on the femurs. The diabetic group had significantly higher bone fragility than the other groups (Pr >.05). Bone fragility was lower, and bone flexibility was higher in the Ang 1-7 groups (Pr>F value 0.05). As a result of our study, the effect of Ang 1-7 on the bones of rats with diabetes was investigated biomechanically. Ang 1-7 has a protective impact on the bones of rats with diabetes.

Se sabe que la diabetes mellitus tiene complicaciones tardías, incluyendo enfermedades microvasculares y macrovasculares. La diabetes puede afectar los huesos a través de los marcadores bioquímicos de la estructura, la densidad y el recambio óseo. Este estudio tuvo como objetivo investigar biomecánicamente los efectos protectores en los huesos de la angiotensina 1-7 (Ang 1-7), uno de los péptidos activos en el sistema renina-angiotensina, en ratas con diabetes. Treinta ratas albinas Wistar macho, de tres meses de edad y con un peso de 250-300 g, se dividieron en cuatro grupos: diabetes, Ang 1-7, diabetes más Ang 1-7 y control. Un mes después, se desarrolló diabetes en ratas; se sacrificaron los animales y se extrajo su fémur derecho. Se realizaron pruebas biomecánicas de flexión de tres puntos en los fémures. El grupo diabéticos tenía una fragilidad ósea significativamente mayor que los otros grupos (Pr > 0,05). La fragilidad ósea fue menor y la flexibilidad ósea fue mayor en los grupos Ang 1-7 (valor Pr>F 0,05). Como resultado de nuestro estudio, se determinó biomecánicamente el efecto de Ang 1-7 en los huesos de ratas con diabetes. Se concluye que Ang 1-7 tiene un impacto protector en los huesos de ratas diabéticas.

Exposure to endocrine disruptors and alterations in mineralized tissues: a narrative review / Exposición a disruptores endocrinos y alteraciones en tejidos mineralizados: revisión narrativa

Background: Endocrine Disrupting Chemicals (EDCs) would cause alterations in organs/systems of exposed individuals or their progeny. Objetive: To identify and analyze the main published findings on the effects of exposure to EDCs on teeth, cartilage, and bone. Material and Methods: Two databases were analyzed: Medline and Web of Science. Only observational studies analyzing the effect of EDCs on mineralized tissues published since 2006 were included in the study. Results: 25 articles were selected, most of them involving EDCs pesticides, plasticizers, or personal care products, highlighting organochlorine compounds, bisphenols, phthalates, dioxins, parabens, and perfluoroalkyls. Thirty-six per cent of the studies reported an accumulation of EDCs in teeth or bones, while 64% reported alterations in their development or morphology, mainly at the bone level, primarily affecting their mineral density and size, as well as that of the bones of exposed individuals or their progeny. The type of effect observed was related to the EDCs analyzed, and it seemed to depend on variables such as age, sex, ethnicity/race, and even the metabolic status of the individuals in the different species analyzed. No evidence associated with effects on cartilage was found. Conclusion: EDCs in the environment, at work, or at home, under different exposure routes, are capable of accumulating in teeth and bone, particularly affecting the latter. It is necessary to study the effect of EDCs on mineralized tissues in agro-industrial areas, especially on teeth.

Antecedentes: Los Químicos Disruptores Endocrinos (EDCs) causarían alteraciones en órganos/sistemas de individuos expuestos, o su progenie. Objetivo: Identificar y analizar los principales hallazgos publicados sobre el efecto de la exposición a EDCs en dientes, cartílago y hueso. Material y Métodos: Se analizaron dos bases de datos: Medline y Web of Science, incluyendo solo estudios observacionales publicados desde el 2006, analizando el efecto de los EDCs sobre tejidos mineralizados. Resultados:25 artículos fueron seleccionados, siendo la mayoría de los EDCs pesticidas, plastificantes o productos de cuidado personal, destacando los compuestos Organo-clorados, Bisfenoles, Ftalatos, Dioxinas, Parabenos y los Perfluoroalquilos. Un 36% de los estudios reportaron un acúmulo de EDCs en dientes o huesos, mientras que un 64% informaron de alteraciones en su desarrollo o morfología, particularmente a nivel de huesos, afectando principalmente su densidad mineral y su tamaño, así como el de los individuos expuestos o su progenie. El tipo de efecto observado tuvo relación con el EDCs analizado, pareciendo depender de variables tales como edad, sexo, etnia/raza e incluso el estado metabólico de los individuos, en las diferentes especies analizadas. No se encontraron evidencias asociadas a efectos en el cartílago. Conclusión: Los EDCs en el medio ambiente, ámbito laboral o doméstico, bajo distintas rutas de exposición, son capaces de acumularse en diente y hueso, afectando particularmente a este último. Es necesario estudiar el efecto de los EDCs en los tejidos mineralizados en zonas agroindustriales, particularmente a nivel de dientes.

Histopathological and immunohistochemical study of antiosteoporotic efficacy of the earthworm Allolobophora caliginosa extract in orchiectomized rats / Estudio histopatológico e inmunohistoquímico de la eficacia antiosteoporótica del extracto de lombriz de tierra Allolobophora caliginosa en ratas orquiectomizadas

SUMMARY: Osteoporosis is a bone condition marked by a loss of bone mass and a disruption of bone microarchitecture. Men lose bone density as they age, resulting in brittle bones. The loss of free testosterone is one of the key factors. The objective of present study was to evaluate Allolobophora caliginosa extract (AcE) for its anti-osteoporotic and antiapoptotic activity in orchiotomized rat model at two different dose levels. Twenty eight male rats were divided into two groups. The first group represented sham operated rats while the second group underwent bilateral orchidectomy (OCX). After one week of recovery from orchidectomy surgery, the second group was randomly subdivided into 3 subgroups. The first OCX subgroup was administered orally distilled water daily for 10 weeks. The other two OCX subgroups were administered AcE (100 or200 mg/kg body weight/day) orally for 10 weeks. Orchiectomy induces remarkable loss of the cortical as well as trabecular bone loss; which, could be counterbalanced by Allolobophora caliginosa extract (AcE) that prevented cortical as well as trabecular bone loss. Allolobophora caliginosa extract (AcE) at Dose 200 mg/kg/day was found to be effective at a highly significant level in osteoporotic bone, as determined by histological images and immunohistochemical study, where Dose (100 mg/kg/day) was found to be moderately significant.In the present study, it is suggested that AcE may inhibit steroid-induced osteoblasts apoptosis, potentially via upregulation of Bcl-2 and downregulation of caspase-3. Allolobophora caliginosa extract demonstrates anti-apoptotic and anti-oxidant properties. Therefore, AcE may be used for the prevention of steroid-induced bone damage.

RESUMEN: La osteoporosis es una afección ósea caracterizada por una pérdida de masa ósea y una alteración de la microarquitectura ósea. Los hombres pierden densidad ósea a medida que envejecen, lo que resulta en huesos quebradizos. La pérdida de testosterona libre es factor clave en este proceso. El objetivo del presente estudio fue evaluar el extracto de Allolobophora caliginosa (AcE) debido a su actividad antiosteoporótica y antiapoptótica en un modelo de rata orquiectomizadas con dos niveles de dosis diferentes. Se dividieron veintiocho ratas macho en dos grupos. El primer grupo incluyó ratas con operación simulada, mientras que el segundo grupo se sometió a orquidectomía bilateral (OCX). Después de una semana de recuperación de la orquidectomía, el segundo grupo fue subdividido en 3 subgrupos. Al primer subgrupo de OCX se administró diariamente agua destilada por vía oral durante 10 semanas. Los otros dos subgrupos de OCX se administraron por vía oral AcE (100 o 200 mg / kg de peso corporal / día) durante 10 semanas. La orquidectomía induce una pérdida notable del hueso cortical y trabecular; el cual podría ser contrarrestado por el extracto de Allolobophora caliginosa (AcE) que previno la pérdida de hueso tanto cortical como trabecular visualizado en imágenes histológicas y estudio inmuno- histoquímico, donde se encontró que la dosis (100 mg / kg / día) era moderadamente significativa. En el presente estudio, se sugiere que la AcE puede inhibir la apoptosis de los osteoblastos inducida por esteroides, potencialmente a través de la regulación al alza de Bcl 2 y la regulación a la baja de caspasa 3. El extracto de Allolobophora caliginosa demuestra propiedades anti apoptóticas y antioxidantes. Por lo tanto, AcE puede usarse para la prevención del daño óseo inducido por esteroides.

Síndrome metabólico, metformina y hueso / Metabolic syndrome, metformin and bone

El síndrome metabólico se define como un trastorno heterogéneo y multifactorial con riesgo cardiovascular elevado. Actualmente se encuentra en franco crecimiento debido al sedentarismo y la ingesta rica en grasas y azúcares. Su tratamiento incluye la indicación de cambios en el estilo de vida, con realización de actividad física y una alimentación saludable e hipocalórica. Cuando esto no es eficaz, se pueden utilizar diferentes fármacos, y entre los más prescriptos se encuentra la metformina, caracterizada por su acción insulino-sensibilizante. Numerosos trabajos han estudiado la vinculación del síndrome metabólico con el tejido óseo. Se demostró como resultado general, aunque no concluyente, que dicho síndrome se asocia con una disminución de la densidad mineral ósea y un aumento en la incidencia de fracturas osteoporóticas. Una de las limitaciones de estos estudios clínicos estaría ligada a la gran heterogeneidad de los pacientes con síndrome metabólico. Por otra parte, y dado que diversos estudios preclínicos han sugerido posibles acciones osteogénicas de la metformina, se ha investigado el posible efecto óseo de un tratamiento con este fármaco en personas con hiperglucemia o disglucemia. Varios estudios clínicos muestran que este efecto sería nulo o, en algunos casos, de carácter protector para el sistema óseo. No obstante, se debería tener precaución en el uso de dicho fármaco en pacientes que necesiten dosis altas y/o posean riesgo elevado de fractura, ya que sus altas concentraciones podrían tener consecuencias negativas sobre el metabolismo óseo. (AU)

Metabolic syndrome is defined as a heterogeneous and multifactorial disorder with high cardiovascular risk. Its incidence is currently growing due to sedentary lifestyles and diets with a high intake of fats and sugars. Treatment for metabolic syndrome begins with changes in lifestyle, such as physical activity and a healthy and hypocaloric diet. When this is not effective, different drugs can be used, and one of the most frequently prescribed is the insulin-sensitizer metformin. Numerous investigations have evaluated the possible link between metabolic syndrome and alterations in bone metabolism. Although not conclusive, most clinical studies point to an association between metabolic syndrome, a decrease in bone mineral density and an increase in the incidence of osteoporotic fractures. However, an important limitation of these studies is the great heterogeneity of individuals with metabolic syndrome. In view of preclinical research indicating possible osteogenic actions of metformin, the effects on bone of metformin has been evaluated in patients with hyperglycemia. Most studies have found either no effect on fracture incidence, or a mild protective action. However, since elevated concentrations of metformin might negatively affect bone metabolism, caution should be taken when prescribing this drug for patients who require high doses, and/or have an excess fracture risk. (AU)

Signs of alveolar bone damage in early stages of periodontitis and its prevention by stimulation of cannabinoid receptor 2. Model in rats / Signos de daño óseo alveolar en estadios tempranos de periodontitis y su prevención por estimulación del receptor cannabinoide 2. Modelo en ratas microcisalhamento do cimento resinoso

ABSTRACT The aims of the present study were, first, to identify signs of alveolar bone damage in early stages of experimental periodontitis (EP) and, second, to assess its possible prevention by treatment with cannabinoid receptor 2 agonist HU 308. Experimental periodontitis was induced by injections of lipopolysaccharide (LPS) (1mg/ml) in gums surrounding maxillary and mandibular first molar, 3 days per week, and untreated controls were kept for comparison. Then, a 3-week study was conducted including eighteen new rats (six rats per group): 1) controls; 2) experimental periodontitis rats; and 3) experimental periodontitis rats treated daily with HU 308 (500 ng/ml). After euthanasia, alveolar bone loss was assessed by morphometric and histomorphometric techniques, and the content of prostaglandin E2 (PGE2) in gingival tissue was evaluated by radioimmunoassay. The first signs of alveolar bone loss were apparent at 3 weeks of experimental periodontitis (ρ<0.05) in the mandibular first molar, but there was no detectable change at 1 week, leading us to establish 3 weeks as an early stage of experimental periodontitis. Rats subjected to 3-week experimental periodontitis showed less interradicular bone volume, less whole bone perimeter and fewer bone formation areas, and higher periodontal space height, bone resorption areas, number of osteoclasts and gingival content of prostaglandin E2 than controls, while HU 308 prevented, at least partially, the deleterious effects (ρ<0.001). We can conclude that a 3-week term of lipopolysaccharide-induced periodontitis in rats provides a valid model of the early stage of the disease, as emerging damage is observed in bone tissue. Furthermore, harmful effects at 3 weeks could be prevented by local stimulation of cannabinoid receptor 2, before greater damage is produced.

RESUMEN El objetivo del presente trabajo fue, en primer lugar, identificar signos de daño óseo alveolar en estadios tempranos de periodontitis experimental y, en segundo lugar, evaluar su posible prevención mediante el tratamiento con el agonista del receptor cannabinoide 2, HU 308. La periodontitis experimental fue inducida por inyecciones de lipopolisacárido (1mg/ml) en la encía circundante al primer molar maxilar y mandibular, 3 días por semana, en tanto que controles no tratados fueron mantenidos para la comparación. Posteriormente, un estudio de 3 semanas con dieciocho nuevas ratas (seis por grupo) fue desarrollado: 1) controles; 2) ratas con periodontitis experimental, y 3) ratas con periodontitis experimental tratadas diariamente con HU 308 (500ng/ml). Luego de la euthanasia, la pérdida ósea alveolar fue evaluada por técnicas morfométricas e histomorfométricas, y el contenido de prostaglandina E2 en el tejido gingival fue determinado por radioinmunoensayo. Los primeros signos de pérdida ósea alveolar fueron evidentes a las 3 semanas de inducción de periodontitis experimental (ρ<0.05) en el primer molar mandibular, mientras que no hubo cambios detectables luego de 1 semana de inducción, hecho que nos condujo a establecer a las 3 semanas como un estadio temprano de periodontitis experimental, Las ratas sometidas a perdiodontitis experimental de 3 semanas mostraron menor volumen óseo interradicular, menor perímetro óseo y menos áreas de formación ósea, y mayor altura del espacio periodontal, más áreas de reabsorción ósea, mayor número de osteoclastos y mayor contenido gingival de prostaglandina E2, en comparación a los controles, mientras que el tratamiento con HU 308 previno, al menos parcialmente, los efectos deletéreos (ρ<0.001). Podemos concluir que el término de 3 semanas de periodontitis inducida por lipopolisacárido es un modelo válido de estadio inicial de la enfermedad experimental, dado que se evidencia daño emergente en el tejido óseo. Asimismo, los efectos deletéreos de 3 semanas podrían ser prevenidos por la estimulación local del receptor cannabinoide 2, antes que un daño mayor sea producido.

Chemical composition by HPLC-ESI-QTOF-MS/MS: Estrogenic and antioxidant effects of Mangifera indica L. cv. "Kent" leave extracts on ovariectomized rats / Composición química por HPLC-ESI-QTOF-MS/MS: efectos estrogénicos y antioxidantes de extractos de Mangifera indica L. cv. "Kent" en ratas ovariectomizadas

The chemical composition of Mangifera indica L. cv. "Kent" leaves was determined by HPLC-ESI-QTOF-MS/MS. Polyphenolic compounds characterized as benzophenone derivatives were the main components found in extracts (1, maclurin 3-C-(2-O-galloyl)-D- glucoside isomer; 2, maclurin 3-C---D-glucoside; 3, iriflophenone 3-C---D-glucoside; 5, maclurin 3-C-(2,3-di-O-galloyl)---D-glucoside; 6, iriflophenone 3-C-(2-O-galloyl)---D-glucoside; 7, methyl-iriflophenone 3-C-(2,6-di-O-galloyl)---D-glucoside) and xanthones (4, mangiferin and 8, 6-O-galloyl-mangiferin). The estrogenic and antioxidant effects of aqueous extracts from Mangifera indica L. cv. "Kent" leaves on ovariectomized rats were determined by uterotrophic assay and malondialdehyde (MDA) levels in erythrocytes, bone, liver, and stomach. We conclude that the polyphenolic compounds from extracts act as exogenous antioxidant agents against oxidative damage in ovariectomized rats.

La composición química de las hojas de Mangifera indica L. cv. "Kent" se determinó por HPLC-ESI-QTOF-MS/MS. Compuestos polifenólicos caracterizados como derivados de benzofenona fueron los componentes principales encontrados en los extractos (1, isómero de la maclurina 3-C-(2-O-galoyil)-D-glucósido; 2, maclurina 3-C-ß-D-glucósido; 3, iriflofenona 3-C-ß-D-glucósido; 5, maclurina 3-C-(2,3-di-O-galloíl)-ß-D-glucósido; 6, iriflofenona 3-C-(2-O-galloil)-ß-D-glucósido; 7, metil-iriflofenona 3-C-(2,6-di-O- galloyl)-ß-D-glucósido) y xantonas (4, mangiferina y 8, 6-O-galoyil-mangiferina). Los efectos estrogénicos y antioxidantes de los extractos acuosos de hojas de Mangifera indica L. cv. "Kent" en ratas ovariectomizadas se determinaron mediante ensayo uterotrófico y la medición de los niveles de malondialdehído (MDA) en eritrocitos, huesos, hígado y estómago. Concluimos que los compuestos polifenólicos de los extractos actúan como agentes antioxidantes exógenos contra el daño oxidativo en ratas ovariectomizadas.

Effects of NSAIDs and environmental oxygen pressure on bone regeneration / Efecto de los AINEs y la presión de oxígeno ambiental sobre la regeneración ósea

Objective: To evaluate the effects of administering diclofenac and ketoprofen, as well as the effects of environmental oxygen pressure variation on mandibular bone regeneration. Methods: Thirty-six guinea pigs were distributed into two equal groups. Mandibular bone defects were performed on both groups. Group A was monitored under oxygen pressure at altitude (3320msl, 107mm Hg). Group B was monitored at sea level oxygen pressure (150msl, 157mm Hg). Each group was subdivided into 3 equal groups (A1, A2, A3 and B1, B2, B3). Subgroups A1 and B1 were given diclofenac; subgroups A2 and B2 ketoprofen; subgroups A3 and B3 NaCl. Bone regeneration was evaluated histologically on days 15 and 30. Results: After 15 days in the group controlled at sea level, the level of osteoblasts presented by the control subgroup was significantly higher (28.00±2.65) compared to the diclofenac subgroup (16.00±6.25) and to the ketoprofen subgroup (18.00±4.36); (p=0.041). After 15 days in the group controlled at altitude, the level of osteoblasts was significantly higher in the control subgroup (38.00±5.29) compared to the diclofenac subgroup (21.67±6.35) and to the ketoprofen subgroup (19.33±2.52); p=0.007. After 30 days in the group at sea level there was no difference found in the cell counting; p>0.05. After 30 days in the group controlled at altitude, the level of osteoblast was significantly higher in the control subgroup (58.00±4.58) compared to the diclofenac subgroup (34.33±4.73) and the ketoprofen subgroup (34.00±11.14); (p=0.003). Conclusion: The administration of diclofenac and ketoprofen produced lower mandibular bone regeneration, the effect being significantly more negative at sea level.

Objetivo: Evaluar el efecto de la administración de diclofenaco y ketoprofeno y de la variación de la presión de oxígeno ambiental sobre la regeneración ósea mandibular. Métodos: Participaron 36 cobayos distribuidos en dos grupos iguales. A ambos grupos se les realizaron defectos óseos mandibulares. El Grupo A fue controlado bajo presión de oxígeno en altura (3320msnm, 107mm Hg). El Grupo B fue controlado bajo presión de oxígeno a nivel del mar (150msnm, 157mm Hg). Cada grupo fue dividido en 3 subgrupos iguales (A1, A2, A3 y B1, B2, B3). Los subgrupos A1 y B1 recibieron diclofenaco; A2 y B2, ketoprofeno; A3 y B3, NaCl. La regeneración ósea fue evaluada histológicamente a los 15 y 30 días. Resultados: A nivel del mar, a los 15 días, hubo una significativa mayor cantidad de osteoblastos en el subgrupo control (28,00±2,65) comparado con el subgrupo diclofenaco (16,00±6.25) y ketoprofeno (18,00±4.36); (p=0,041). En altura, a los 15 días, hubo una significativa mayor cantidad de osteblastos en el subgrupo control (38,00±5,29) comparado con el subgrupo diclofenaco (21,67±6,35) y ketoprofeno (19,33±2,52); p=0,007. A nivel del mar, a los 30 días, no se encontró diferencia en el conteo celular; p>0,05. En altura, a los 30 días, se encontró una significativa mayor cantidad de osteoblastos en el subgrupo control (58,00±4,58) comparado con el subgrupo diclofenaco (34,33±4,73) y ketoprofeno (34,00±11,14); (p=0,003). Conclusión: La administración de diclofenaco y ketoprofeno produjeron una menor regeneración ósea mandibular, siendo este efecto significativamente más negativo a nivel del mar.

Effect of different doses of synthetic parathyroid hormone (1-34) on bone around implants: a preclinical rat model

Abstract The aim of this study was to evaluate the effect of a lower dose of parathyroid hormone- PTH (1-34) on osteogenic potential of bone healing around titanium implants inserted into the tibia of rats. A blind parallel study was conducted in 45 adult male Wistar rats. Each rat received one titanium implant (4.5 x 2.2 mm) and was randomly assigned to receive subcutaneous injections, three times/week for 30 days, of the following treatments: group 1 - 40 µg/kg of PTH (1-34) (n=15); group 2 - 2 µg/kg of PTH (1-34) (n=15) and; group 3 - only the vehicle required for hormone dissolution (n=15). Thirty days after surgery, the animals were sacrificed and specimens containing the implant and the surrounding bone were removed and processed for non-decalcified sections. The sections were evaluated according to the following histometric parameters: proportion of mineralized tissue (PMT) adjacent to the implant threads (500 µm band); bone filling within the limits of the threads (BF) and; bone-to-implant contact (BIC). For the cortical region, both hormone dosages (groups 1 and 2) promoted better results, for all parameters, when compared to control group (p<0.05). Similar results were observed for the BF parameter in the cancellous region (p=0.0394). Therefore, systemic administration of PTH (1-34) stimulates bone formation around titanium implants, even at low doses.

Resumo O objetivo deste estudo foi avaliar o efeito de uma menor dose de PTH (1-34) sobre o potencial osteogênico da cicatrização óssea ao redor de implantes de titânio inseridos na tíbia de ratos. Um estudo paralelo cego foi conduzido em 45 ratos Wistar machos adultos. Cada rato recebeu um implante de titânio (4,5 x 2,2 mm) e foi aleatoriamente designado para receber injeções subcutâneas, três vezes / semana por 30 dias, dos seguintes tratamentos: grupo 1 - 40 µg/kg de PTH (1-34) (n = 15); grupo 2 - 2 µg/kg de PTH (1-34) (n = 15) e; grupo 3 - apenas o veículo necessário para a dissolução do hormônio (n = 15). Trinta dias após a cirurgia, os animais foram sacrificados e os espécimes contendo o implante e o osso ao redor foram removidos e processados ​​para cortes não descalcificados. As seções foram avaliadas de acordo com os seguintes parâmetros histométricos: proporção de tecido mineralizado (PTM) adjacente aos fios do implante (banda de 500 µm); preenchimento ósseo dentro dos limites dos fios (PO) e; contato osso-implante (COI). Para a região cortical, ambas as dosagens hormonais (grupos 1 e 2) promoveram melhores resultados, para todos os parâmetros, quando comparados ao grupo controle (p<0,05). Resultados semelhantes foram observados para o parâmetro PO na região esponjosa (p = 0,0394). Portanto, a administração sistêmica de PTH (1-34) estimula a formação óssea ao redor de implantes de titânio, mesmo em doses baixas.

Muscle strength training is better than the use of growth hormone (GH) in bone health of Wistar rats / Entrenamiento de la fuerza muscular es mejor que el uso de la hormona del crecimiento (GH) en salud ósea del ratas Wistar

SUMMARY: The objective of this study was to evaluate the effects of growth hormone (GH) and muscle strength training (ST) on the composition of bone tissue of Wistar rats through Raman spectroscopy. In total, 40 male rats were randomly distributed into four groups: (N = 10) control (C), control with the application of GH (GHC), strength training (T), and strength training with the application of GH (GHT). The training consisted of four series of 10 water jumps, performed three times a week, with an overload corresponding to 50 % of body weight and duration of four weeks. GH was applied at a dose of 0.2 IU / kg in each animal three times a week and every other day. After four weeks, the animals were euthanized and the right femurs collected for analysis of the bone structure. Raman spectroscopy (ER) was used to observe the following compounds from their respective bands: Calcium Carbonate-Triglycerides (fatty acids) 1073 cm-1, Collagen type I 509 cm-1, Bone-DNA Phosphate (Protein) 589 cm-1, Phosphate Phospholipids 1078 cm-1. For the statistical analysis, the Shapiro-Wilk and ANOVA One-Way variance analysis normality tests were performed, followed by the Tukey post-test. The results showed an increase in the concentrations of calcium carbonate-triglycerides (fatty acids), type I collagen, bone phosphate-DNA (protein), and phosphate phospholipids in all experimental groups, with or without ST and/or GH , But only the isolated training group differed significantly from the control group (P <0.05). It was concluded that all treatments could promote bone tissue gain, however, only the T group demonstrated a significant difference in the mineral compounds analyzed.

RESUMEN: El objetivo del estudio fue avaluar el efecto de la aplicación de la hormona del crecimiento (GH) y entrenamiento de la fuerza muscular (EF) en la composición del tejido óseo de ratas Wistar a partir de la espectroscopía Raman. Fueron utilizadas 40 ratas machos distribuidas de forma aleatoria en cuatro grupos (n=10): control (C), control y aplicación de GH (GHC), entrenamiento de la fuerza muscular (EF) y entrenamiento de la fuerza muscular y aplicación del GH (GHE). El entrenamiento fue consistió en cuatro series de 10 saltos acuáticos, realizados tres veces en la semana, con sobrecarga correspondiente a 50 % de la masa corporal y durante cuatro semanas. El GH fue aplicado en la dosificación de 0,2 UI/kg en cada animal, tres veces en la semana y en días alternados. Después de cuatro semanas, los animales fueran eutanasiados y retirados los fémures derechos para un análisis de la estructura ósea. La espectroscopía Raman fue utilizada para observar los siguientes compuestos a partir de las respectivas bandas: Carbonato de Calcio-Triglicéridos (ácidos grasos) 1073 cm-1, Colágeno Tipo I 509 cm-1, Fosfato Óseo-DNA (Proteína) 589 cm1, Fosfato Fosfolípidos 1078 cm-1. Para el análisis estadístico, fueron realizadas las pruebas Shapiro-Wilk y el análisis de variancia ANOVA One-Way, seguida de test post hoc de Tukey. Los resultados revelaran aumento de la concentración de Carbonato de Calcio-Triglicéridos (ácidos grasos), Colágeno Tipo I, Fosfato Óseo- DNA (Proteína), Fosfato Fosfolípidos en todos los grupos experimentales, asociados o no a la realización del EF y/o aplicación del GH. Además, solamente el grupo EF mostró diferencia significativa del grupo C (p<0,05). Es posible concluir que todos los tratamientos mostraran aumentos en el tejido óseo, sin embargo, solamente el grupo T demostró una diferencia significativa en los compuestos minerales analizados.

Zoledronic acid effect on bone of growing rats / Efecto del ácido zoledrónico en el hueso de ratas en crecimiento

Zoledronic acid (ZA) is an antiresorptive drug used in children with bone diseases like osteogenesis imperfecta, juvenil osteoporosis, fibrous dysplasia and primary bone tumors. The aim of the present study was to evaluate the effects of ZA dose accumulation on growing bone during different periods of treatment in normal rats. Methods: A 4x2 factorial design was used to study the effect of the dose of ZA (D: 0-2.5-12.5-25 µg Z/kg body weight/s.c. weekly) and the length of treatment (T: 15-30 days) in normal female Sprague Dawley rats. Bone morphometric, histomorphometric, densitometric and biomechanical studies were performed. Results: Femoral length and cross-sectional area were affected by both D and T. A significant interaction between D and T was observed in length with a lower value at higher dose and 30 days of treatment. Growth plate of the tibia showed a decrease in total thickness with D and T. Histomorphometric and connectivity parameters of trabecular bone were significantly increased with D and several parameters were also affected by T. Cortical bone strength was increased only with T. Biomechanical parameters of trabecular bone showed significant interaction with greater effect at higher D and T. Conclusion: Even though a mild negative effect of the highest dose of ZA on linear and appositional growth was observed, the other bone parameters evaluated were improved. A careful risk/benefit analysis would lead us to conclude that the mild deleterious effects of ZA during growth are outweighed by the benefit obtained with treatment. (AU)

El ácido zoledrónico (AZ) es un fármaco antirresortivo utilizado en niños con enfermedades óseas como osteogénesis imperfecta, osteoporosis juvenil, displasia fibrosa y tumores óseos primarios. El objetivo del presente estudio fue evaluar los efectos de las dosis acumuladas de AZ en el hueso en crecimiento de ratas hembras normales durante diferentes períodos de tratamiento. Métodos: se utilizó un diseño factorial de 4x2 para estudiar el efecto de la dosis de AZ (D: 0-2,5-12,5-25 µg Z / kg de peso corporal /sc semanalmente) y el período de tratamiento (T: 15-30 días) en ratas Sprague Dawley. Se realizaron estudios óseos morfométricos, histomorfométricos, densitométricos y biomecánicos. Resultados: la longitud y el área de sección transversal del fémur se vieron afectadas tanto por D como por T. Se observó una interacción significativa entre D y T en la longitud obteniéndose un valor más bajo a la dosis más alta y a 30 días de tratamiento. El cartílago de crecimiento de la tibia mostró una disminución en el espesor total con D y T. Los parámetros histomorfométricos y de conectividad del hueso trabecular aumentaron significativamente con D y varios parámetros también se vieron afectados por T. La fortaleza ósea cortical aumentó solo con T. Los parámetros biomecánicos del hueso trabecular mostraron una interacción significativa con un mayor efecto a mayor D y T. Conclusión: a pesar que se observó un leve efecto negativo de la dosis más alta de AZ sobre el crecimiento lineal y aposicional, el resto de los parámetros óseos evaluados mejoraron. Un análisis cuidadoso del riesgo /beneficio permite concluir que los efectos negativos leves del AZ durante el crecimiento son superados por el beneficio obtenido con el tratamiento. (AU)

The effect of the new hemostatic agent Ostene on bone healing: an experimental study in rabbits

Introduction: Ostene is a water-soluble wax-like alkylene oxide copolymer preparation for use as a mechanical hemostatic agent. this study aims to evaluate the effects of Ostene on bone healing. materials and methods: twenty albino rabbits were divided into four groups according to post-treatment follow-up (24 hr, 3 days, 7 days, 14 days) with five rabbits in each group. each rabbit in all groups was treated with two study materials (Ostene and Gelfoam). three holes were made in the mandibular bone of each rabbit using 5mm surgical bur; two holes were made on right side: one for testing Ostene and another for Gelfoam. a third hole, on the left side of mandible, was not treated, and was used as a control. finally, the incision was closed. the specimens were collected at different days post-treatment and examined by histopathology. result and discussion: this study showed that there is a significant difference (p-value≤ 0.05) between the Ostene group and the other groups (Gelfoam and control). at 24 hr post intervention, there is a significant difference in osteoblast cell formation (p-value=0.03), and osteoclast cell formation (p-value=0.05). new blood vessel formation, osteoblast and osteoclast cell formation for Ostene group at 3 days post-intervention were also significantly different (p-values = 0.05, 0.03, 0.04, respectively). at 7 days post-intervention p-values were 0.05 for osteoblast formation and 0.04 for osteoclast formation, respectively. after 14 days of healing p-value for osteoblast cell formation in the Ostene group was 0.05 and 0.04 for osteoclast cell formation. conclusions: the bone hemostatic agent Ostene is an effective at enhancing osteogenesis by initiating proliferation of osteoblast and osteoclast cells.

Osteoprotective properties of RNA-containing drug osteochondrin S on the model of insufficiency of sex hormones in rats / Propiedades osteoprotectoras del fármaco que contiene ARN de osteocondrina S sobre un modelo de insuficiencia de hormonas sexuales en ratas

SUMMARY: The aim of the study was to evaluate the osteoprotective properties of RNA-containing drug Osteochondrin S on rats with experimental model of osteoporosis. Osteochondrin S contains yeast RNA and RNA of connective tissue of cattle. In order to model osteoporosis in rats bilateral ovariectomy was used. Rats were divided into 3 groups: 1 - ovariectomized rats receiving Osteochondrin S; 2 - ovariectomized rats receiving saline; 3 - sham-ovariectomized rats. Rats in group 1 received Osteochondrin S, Group 2 - physiological saline three times a week for 12 weeks. Based on morphological data and on the results of densitometry, Osteochondrin S prevents a decrease in bone density, i.e. exhibits osteoprotective properties. Under the condition of lack of sex hormones in rats Osteochondrin S reduces reactive oxygen species in blood plasma and limits the degree of decrease in antioxidant capacity of blood plasma.

RESUMEN: El objetivo de este estudio fue evaluar las propiedades osteoprotectoras del fármaco que contiene ARN Osteocondrina S en ratas, como modelo experimental de osteoporosis. La Osteocondrina S contiene ARN de levadura y ARN de tejido conectivo de bovinos. Para modelar la osteoporosis en ratas se utilizó ovariectomía bilateral. Las ratas se dividieron en 3 grupos: grupo 1, ratas ovariectomizadas que recibieron Osteocondrin S; grupo 2, ratas ovariectomizadas recibieron solución salina; grupo 3 - ratas ovariectomizadas simuladas. Las ratas del grupo 1 recibieron Osteocondrina S, el grupo 2 solución de suero fisiológico tres veces por semana durante 12 semanas. En base a los datos morfológicos y los resultados de la densitometría, Osteocondrina S evita una disminución de la densidad ósea, es decir, exhibe propiedades osteoprotectoras. Ante la falta de hormonas sexuales en ratas, Osteocondrina S reduce las especies reactivas de oxígeno en el plasma sanguíneo y limita el grado de disminución de la capacidad antioxidante del plasma sanguíneo.

Repair of Bone Defects with Chitosan-Collagen Biomembrane and Scaffold Containing Calcium Aluminate Cement

Abstract Innovative biomaterials can provide a promising new direction for the treatment of bone defects, stimulating a proper repair process, with no damage to adjacent tissues. The purpose of this in vivo study was to evaluate the biocompatibility and the osteoinductive capacity of chitosan-collagen biomembrane and scaffold containing calcium aluminate cement. Eighteen New Zealand white rabbits (Oryctolagus cuniculus) were distributed according to the experimental times of analysis (7, 15 and 30 days). Four bone defects were created in the rabbits calvaria, which were individually filled with the biomembrane, scaffold, blood clot (negative control) and autologous bone (positive control). Histopathological analysis was performed using optical microscope at 32´, 64´, 125´ and 320´ magnifications. Cell response to inflammation and new bone tissue formation was quantified using a score system. The biomembrane group presented greater inflammatory response at 15 days, with significant difference to autologous bone group (p<0.05). There was no statistically significant difference for foreign body type reaction among groups (p>0.05). Concerning new bone formation, linear closure of the defect area was observed more evidently in the group with autologous bone. The scaffold group presented similar results compared with the autologous bone group at 30 days (p>0.05). Both tested biomaterials presented similar biocompatibility compared with the control groups. In addition, the biomembrane and scaffold presented similar osteoinductive capacity, stimulating bone repair process in the course of the experimental time intervals.

Resumo Biomateriais inovadores podem fornecer uma promissora nova direção para o tratamento de defeitos ósseos, estimulando um processo de reparo adequado, sem danos aos tecidos adjacentes. O objetivo deste estudo in vivo foi avaliar a biocompatibilidade e a capacidade osteoindutora de uma biomembrana e um scaffold compostos por colágeno e quitosana, contendo cimento de aluminato de cálcio. Dezoito coelhos (New Zealand White, Oryctolagus cuniculus) foram distribuídos de acordo com os períodos experimentais de análise (7, 15 e 30 dias). Quatro defeitos foram criados na calvaria dos coelhos, que foram individualmente preenchidos com a biomembrana, scaffold, coágulo (controle negativo) e osso autólogo (controle positivo). A avaliação histopatológica foi realizada em microscópio óptico em aumentos de 32´, 64´, 125´ e 320´. A resposta celular à inflamação e à formação de novo tecido ósseo foi quantificada utilizando um sistema de escore. O grupo da biomembrana apresentou maior resposta inflamatória no período de 15 dias, com diferença significativa para o grupo do osso autólogo (p<0,05). Não houve diferença estatística significante para a reação do tipo corpo estranho entre os grupos (p>0,05). Em relação à neoformação óssea, observou-se fechamento linear da área do defeito, que foi mais evidente no grupo em que se utilizou o osso autólogo. O grupo scaffold apresentou resultados semelhantes ao grupo do osso autólogo no período de 30 dias (p>0,05). Ambos os biomateriais testados apresentaram biocompatibilidade similar em comparação com os grupos controle. Além disso, a biomembrana e o scaffold apresentaram capacidade osteoindutora similar, estimulando o reparo ósseo ao longo dos intervalos de tempo experimentais.

Hepatic Osteodystrophy: The Mechanism of Bone Loss in Hepatocellular Disease and the Effects of Pamidronate Treatment

OBJECTIVES: The present study was designed to evaluate the bone phenotypes and mechanisms involved in bone disorders associated with hepatic osteodystrophy. Hepatocellular disease was induced by carbon tetrachloride (CCl4). In addition, the effects of disodium pamidronate on bone tissue were evaluated. METHODS: The study included 4 groups of 15 mice: a) C = mice subjected to vehicle injections; b) C+P = mice subjected to vehicle and pamidronate injections; c) CCl4+V = mice subjected to CCl4 and vehicle injections; and d) CCl4+P = mice subjected to CCl4 and pamidronate injections. CCl4 or vehicle was administered for 8 weeks, while pamidronate or vehicle was injected at the end of the fourth week. Bone histomorphometry and biomechanical analysis were performed in tibiae, while femora were used for micro-computed tomography and gene expression. RESULTS: CCl4 mice exhibited decreased bone volume/trabecular volume and trabecular numbers, as well as increased trabecular separation, as determined by bone histomorphometry and micro-computed tomography, but these changes were not detected in the group treated with pamidronate. CCl4 mice showed increased numbers of osteoclasts and resorption surface. High serum levels of receptor activator of nuclear factor-κB ligand and the increased expression of tartrate-resistant acid phosphatase in the bones of CCl4 mice supported the enhancement of bone resorption in these mice. CONCLUSION: Taken together, these results suggest that bone resorption is the main mechanism of bone loss in chronic hepatocellular disease in mice.

Effects of the use of growth hormone in children and adolescents with juvenile idiopathic arthritis: a systematic review / Efeitos do uso do hormônio de crescimento em crianças e adolescentes com artrite idiopática juvenil: revisão sistemática

Abstract Introduction: Children with juvenile idiopathic arthritis (JIA) often have impaired growth and short stature. There is evidence that the therapeutic use of growth hormone (GH) is useful and safe in these patients. Objective: To analyze the effects of GH use in patients with JIA. Method: A systematic review of the literature over the last 18 years in Medline and Embase databases. The criteria were analyzed independently by the researchers. We used the following keywords: "growth hormone", "arthritis, juvenile", "arthritis, rheumatoid", "child" and "adolescent". Results: Among the 192 identified articles, 20 corresponded to the inclusion criteria. Seventeen longitudinal studies and 3 case reports were found. Most studies analyzed observed increased growth, muscle mass and bone mass using GH. Adverse effects observed were glucose intolerance, diabetes, bone deformities, osteonecrosis, reactivation of the disease and low final height. Conclusion: The majority of studies reported positive effects after the therapeutic use of GH, but some variability in response to treatment was observed. The combination of growth hormone with other drugs seems to be a good option.

Resumo Introdução: Crianças com artrite idiopática juvenil (AIJ) frequentemente apresentam prejuízo no crescimento e baixa estatura. Existem evidências de que o uso terapêutico do hormônio de crescimento (GH) é útil e seguro nesses pacientes. Objetivo: Analisar os efeitos do uso de GH em pacientes com AIJ. Método: Fez-se revisão sistemática da literatura nos últimos 18 anos, nas bases de dados Medline e Embase. Os critérios foram analisados pelos pesquisadores de forma independente. Usaram-se os seguintes descritores: growth hormone, arthritis, juvenile, arthritis, rheumatoid, child e adolescent. Resultados: Entre os 192 artigos identificados, 20 corresponderam aos critérios de inclusão. Foram encontrados 17 estudos longitudinais e três relatos de casos. A maioria dos estudos analisados observou um aumento de crescimento, massa muscular e massa óssea com o uso do GH. Os efeitos adversos observados foram intolerância à glicose, diabetes, deformidades ósseas, osteonecrose, reativação da doença e altura final baixa. Conclusão: A maioria dos estudos relatou efeitos positivos após uso terapêutico do GH, porém certa variabilidade na resposta ao tratamento foi observada. A combinação do hormônio de crescimento com outros medicamentos parece ser uma boa opção.

Lamivudine, Entecavir, or Tenofovir Treatment of Hepatitis B Infection: Effects on Calcium, Phosphate, FGF23 and Indicators of Bone Metabolism

ABSTRACT Background. Patients with chronic hepatitis B virus (HBV) are often treated with nucleoside/nucleotide antiviral agents and metabolic bone toxicity is a possible concern. Objective. To determine the relationships between fibroblast growth factor 23 (FGF23), a phosphaturic hormone, bone mineral density (BMD), and bone biochemical abnormalities in these patients. Material and methods. This is a cross-sectional observational study comparing HBV-infected subjects treated for at least one year with tenofovir (TDF), lamuvidine (LVD), entacavir (ETV), or not treated (CON). Patients with abnormalities in either calcium (Ca), phosphate (PO4), intact parathyroid hormone (iPTH) or FGF23 were further evaluated with BMD by DXA. Results. No difference in liver enzymes or renal function seen among groups, but hypophosphatemia was seen in all groups with the highest incidence with TDF treatment (14%). FGF 23 levels were found to be elevated in 11.1% of TDF patients, 2.77% amongst controls. No elevations were found in the LVD or ETV groups. Among a subset of subjects (FGF23, PO4, and/or Ca abnormalities) who underwent further evaluation, 67% had insufficient 25-OH vitamin D, and 30% had elevated 24 h urinary Ca or PO4 excretion. No patients with FGF23 abnormalities had urine abnormalities. 40% had low DXA Z-score (<-2) at spine or hip but there was no difference between control and antiviral treatment groups and the mean FRAX score was 2.33% for major osteoporotic fractures and 0.29% for hip fracture. Conclusion. Abnormalities in bone metabolism, particularly involving vitamin D insufficiency, in HBV-treated subjects were observed with a small increased likelihood in TDF treated patients.

Strontium Ranelate Effect on the Repair of Bone Defects and Molecular Components of the Cortical Bone of Rats

Abstract This study was conducted to evaluate the effects of treatment with strontium ranelate (SR) on the repair of bone defects and molecular components of bones in femurs. Adult female rats (n=27) were subjected to ovariectomy (OVX) or Sham surgery. Thirty days after surgery, a defect was made in the femur and the animals were then divided into three groups: OVX, SHAM and OVX+SR. Euthanasia was performed four weeks after the bone defect surgery. Repair in bone defect was assessed by computed microtomography (μCT) and chemical composition of cortical bone was analyzed by Fourier transform infrared (FTIR) spectroscopy and energy dispersive X-ray spectroscopy (EDS). The trabecular thickness (Tb.Th) of the newly formed bone in the OVX+SR group was significantly higher than that for the OVX group. The collagen maturity in the OVX+SR group was smaller than in the other two groups. In this group, a significant increase in the amount of strontium (Sr) and a decrease in the amount of calcium (Ca) embedded to bone tissue were also observed. Systemic treatment with SR improved microarchitecture of the newly formed bone inside the defect, but decreased cross-linking of mature collagen in cortical bone.

Resumo Este estudo foi conduzido para avaliar os efeitos do tratamento com ranelato de estrôncio (RE) na reparação de defeitos ósseos e componentes moleculares de ossos nos fêmures. Ratas adultas (n = 27) foram submetidas a ovariectomia (OVX) ou cirurgia Sham. Trinta dias após a cirurgia, um defeito foi feito no fêmur e os animais foram então divididos em três grupos: OVX, SHAM e OVX+RE. A eutanásia foi realizada quatro semanas após a cirurgia de preparo do defeito ósseo. A reparação do defeito ósseo foi avaliada por microtomografia computorizada (μCT) e a composição química do osso cortical foi analisada por espectroscopia de infravermelho de transformada de Fourier (FTIR) e espectroscopia por energia dispersiva de raios X (EDS). A espessura do osso trabecular (Tb.Th) recém formado no grupo OVX+SR foi significativamente maior que a do grupo OVX. A maturidade do colágeno no grupo OVX+SR foi menor do que nos outros dois grupos. Neste grupo, observou-se também um aumento significativo na quantidade de estrôncio (Sr) e uma diminuição na quantidade de cálcio (Ca) no tecido ósseo. O tratamento sistêmico com RE melhorou a microarquitetura do osso recém formado dentro do defeito, mas diminuiu a reticulação do colágeno maduro no osso cortical.

Calcium intake: good for the bones but bad for the heart? An analysis of clinical studies

ABSTRACT The proper dietary calcium intake and calcium supplementation, when indicated, are important factors in the acquisition of peak bone mass during youth and in the prevention of fractures in old age. In addition to its deposition in bone, calcium confers an increase in its resistance and exhibits important activities in different enzymatic pathways in the body (e.g., neural, hormonal, muscle-related and blood clotting pathways). Thus, calcium supplementation can directly or indirectly affect important functions in the body, such as the control of blood pressure, plasma glucose, body weight, lipid profile and endothelial function. Since one publication reported increased cardiovascular risk due to calcium supplementation, many researchers have studied whether this risk actually exists; the results are conflicting, and the involved mechanisms are uncertain. However, studies that have evaluated the influence of the consumption of foods rich in calcium have reported no increase in the cardiovascular risk, which suggests that nutritional intake should be prioritized as a method for supplementation and that the use of calcium supplements should be reserved for patients who truly need supplementation and are unable to achieve the recommended daily nutritional intake of calcium.

Effects of excess maternal thyroxin on the bones of rat offspring from birth to the post-weaning period

ABSTRACT Objective To evaluate, in rat offspring, bone changes induced by excess maternal thyroxin during pregnancy and lactation, and to assess the reversibility of these changes after weaning. Material and methods Twenty Wistar rats were distributed in two groups, hyperthyroid and control, that were treated daily with L-thyroxin (50 mcg/animal) and placebo, respectively. The treatment was initiated seven days before mating and continued throughout pregnancy and lactation. From every female of each of the two groups, two offspring were euthanized after birth, two at 21 days of age (weaning), and two at 42 days of age (21 days after weaning). In newborns, the length of pelvic and thoracic limbs were measured, and in the other animals, the length and width of the femur and humerus were measured. Bones were dissected, decalcified, embedded in paraffin, and analyzed histomorphometrically. Results Excess maternal thyroxin significantly reduced the length of the pelvic limb in neonates. In 21-day-old individuals, excess maternal thyroxine reduced the length and the width of the femur and the humerus. It also increased thickness of the epiphyseal plate and the percentage of trabecular bone tissue. In 42-day-old individuals, there were no significant differences between groups in relation to the parameters evaluated in the previous periods. Conclusion Excess maternal thyroxine reduced growth in suckling rats both at birth and at weaning, and it also increased the percentage of trabecular bone tissue in 21-day-old animals. These changes, however, were reversible at 42 days, i.e., 21 days after weaning. Arch Endocrinol Metab. 2016;60(2):130-7.