Enfoques terapéuticos de la osteoporosis / Therapeutic approaches to osteoporosis

La finalidad del tratamiento de la osteoporosis es la prevención primaria y secundaria de fracturas. Las indicaciones para las intervenciones terapéuticas en la osteoporosis deben derivarse de la determinación del riesgo absoluto de fractura, que tiene en cuenta la evaluación de los factores de riesgo y la densidad ósea. El propósito de este estudio es comentar algunos enfoques terapéuticos empleados en la osteoporosis, destacando el mecanismo de acción del ranelato de estroncio que aumenta la formación de hueso y disminuye la resorción. La causa más común de osteoporosis en las mujeres es la disminución de los niveles de estrógeno durante la menopausia, lo que lleva a un aumento significativo en el recambio de masa ósea y el consiguiente desequilibrio entre la formación y reabsorción ósea con un aumento de la pérdida ósea y el deterioro de la estructura y fuerza óseas. El ranelato de estroncio sigue siendo una opción farmacológica eficaz y viable en la prevención de las fracturas vertebrales y del cuello femoral en mujeres posmenopáusicas y hombres adultos con osteoporosis, en cuanto a indicaciones, contraindicaciones y una cuidadosa evaluación de sus efectos y riesgos. Representa una alternativa a los medicamentos antirresortivos en caso de contraindicación, intolerancia o fracaso(AU)

The purpose of the treatment of osteoporosis is the primary and secondary prevention of fractures. The indications for therapeutic interventions in osteoporosis should be derived from the determination of the absolute risk of fracture, which takes into account the evaluation of risk factors and bone density. To comment on some therapeutic approaches used in osteoporosis, highlighting the mechanism of action of strontium ranelate that increases bone formation and reduces resorption. The most common cause of osteoporosis in women is the decrease in estrogen levels during menopause, which leads to a significant increase in the turnover of bone mass and the consequent imbalance between bone formation and resorption with an increase in bone loss and deterioration of bone structure and strength. Strontium ranelate continues to be an effective and viable pharmacological option in the prevention of vertebral and femoral neck fractures in postmenopausal women and adult men with osteoporosis, in terms of indications, contraindications and a careful evaluation of its effects and risks. It represents an alternative to antiresorptive drugs in case of contraindication, intolerance or failure(AU)

Impacto clínico del estroncio y del zinc en los procesos de regeneración ósea y del cartílago, aproximación desde la biología hacia la clínica. Revisión de literatura / Clinical impact of strontium and zinc on bone and cartilage regeneration processes, an approach from biology to the clinic. Literature review

Muchos trastornos sistémicos como la artritis o la osteoporosis son patologías responsables de las alteraciones crónicas de la articulación temporomandibular, creando así un problema a largo plazo que afectan la calidad de vida de aquellas personas que las padecen. Actualmente no existe tratamiento curativo para dichas patologías, aunque sí de tipo paliativo, que en muchas ocasiones tienen efectos secundarios en el tiempo o una limitación en su efectividad y eficacia, por lo que se hace necesario buscar alternativas con la implementación de terapias regenerativas para el tratamiento de aquellas enfermedades que afectan el sistema musculoesquelético. En muchos estudios se discute sobre el papel fundamental que cumple el zinc y el estroncio en la génesis de tejido tanto cartilaginoso como óseo, así como la relevancia de incorporarlos con diversos biomateriales en procedimientos de regeneración, sin embargo, este tema no es claro aún y requieren más aten- ción por parte del clínico. El objetivo de este artículo es determinar la función cumplen el zinc y el estroncio en los procesos de regeneración del hueso y el cartílago desde una visión molecular y celular aplicada a la práctica clínica, con el fin de obtener nuevas alternativas en el tratamiento de diversas patologías y alteraciones musculoesqueléticas que mejoren las condiciones de salud oral de los pacientes, además de, contar con la revisión que nos aproxime a comprender los mecanismos de acción de diferentes moléculas que incorporadas a los biomateriales compatibles con el tejido duro y blando mejoren las condiciones biológicas para la regeneración.

Many systemic disorders such as arthritis or osteoporosis are pathologies responsible of temporomandibular joint chronic dysfunctions, thus creating a long-term problem that affects life ́s quality of those who suffer from them. Currently there is no curative treatment for these pathologies, although there is a palliative treatment, which in many cases have side effects over time or a limitation in their effectiveness and efficacy, so it is necessary to look for alternatives with the implementation of regenerative therapies for treatment of those diseases that affect musculoskeletal system. In many studies the fundamental role of zinc and strontium in genesis of both cartilaginous and bone tissue is discussed, as well as the relevance of incorporating them with various biomaterials in regeneration procedures, however, this issue is not clear yet and requires more attention from the clinician. The objective of this article is to determine function of zinc and strontium in regeneration processes of bone and cartilage from a molecular and cellular perspective applied to clinical practice, in order to obtain new alternatives in the treatment of various pathologies and musculoskeletal alterations that improve the oral health conditions of patients. In addition, this review brings us closer to understanding the mechanisms of action of different molecules that when incorporated into biomaterials compatible with hard and soft tissue improve the biological conditions for the regeneration.

Avaliação da morfologia hepática em ratos após administração do ranelato de estrôncio / Evaluation of hepatic morphology in rats after administration of strontium ranelate

Introdução: o fármaco ranelato de estrôncio (RE) é muito utilizado na terapêutica profilática e no controle da osteoporose. Age sistemicamente diminuindo a reabsorção e aumentando a formação óssea, apresentando eventos adversos pouco esclarecidos na literatura, à exemplo a síndrome DRESS com envolvimento hepático. Objetivo: avaliar a morfologia hepática em ratos norvegicus albinus após administração do RE. Metodologia: estudo experimental com 10 ratos, divididos aleatoriamente em dois grupos, Grupo Controle (GC), sem administração do RE, e Grupo Ranelato de Estrôncio (GRE), ambos acompanhados durante 15 dias, e, em seguida, sacrificados e o fígado de cada animal colocado para fixação no solução de formaldeído a 4% durante 48 horas. Após essa etapa, foram realizados os procedimentos necessários à análise pela microscopia óptica, com lâminas coradas pela hematoxilina e eosina, e picrosirius red.Resultados: nos GC e GRE foram encontradas alterações similares, como reação ductular, dilatação sinusoidal e fibrose perissinusoidal, com intensidades distintas entre os grupos, sendo a reação ductular mais proeminente no GC, e a dilatação sinusoidal e fibrose perissinusoidal mais pronunciada no GRE. Além disso, no GC foram evidenciados achados inflamatórios, como presença de infiltrado inflamatório misto e hiperplasia de células de Kupffer, não visualizados no GRE, implicando numa possível ação anti-inflamatória do RE. Conclusão: pode-se concluir que foram visualizadas diferenças nos achados morfológicos do parênquima hepático dos ratos tratados com o RE em comparação aos não tratados, ainda que esses achados não sejam suficientes para inferir a incidência de um processo patológico característico, como cirrose ou hepatite.

Introduction: the drug strontium ranelate (SR) is widely used in prophylactic therapy and in the control of osteoporosis. It acts by reducing reabsorption and increasing bone formation systemically, presenting unclear adverse events in the literature, such as the DRESS syndrome with hepatic involvement. Objective: to evaluate hepatic morphology in norvegicus albinus rats after SR administration. Methodology: experimental group with 10 rats, divided into two groups, randomly distributed, five from the Control Group (CG), without SR administration, and the other five from the Strontium Ranelate Group (SRG), both followed for 15 days, and then sacrificed and the liver of each animal placed for fixation in 4% formalin for 48 hours. After this step, the procedures necessary for the analysis by optical microscopy were performed, with blades stained by hematoxylin e eosin, and picrosirius red. Results: in CG and SRG, similar alterations were observed, such as ductular reaction, sinusoidal dilatation and perissinusoidal fibrosis, with distinct intensities between the groups, being the ductular reaction more prominent in the CG, and sinusoidal dilation and a perissinusoidal fibrosis more pronounced in the SRG. In addition, in the CG were evidenced inflammatory findings such as the presence of mixed inflammatory infiltrate and Kupffer cell hyperplasia, not visualized in the SRG, implying a possible anti-inflammatory action of SR. Conclusion: it can be concluded that differences were observed in the morphological findings of the hepatic parenchyma of rats treated with SR compared to untreated rats, although these findings are not sufficient to infer the incidence of a characteristic pathological process, such as cirrhosis or hepatitis.

Análise microtomografica e imunoistoquímica do osso peri-implantar em dimorfismo sexual com implantes funcionalizados com estrôncio / Microtomographic and immunohistochemical analysis of periimplant bone in sexual dimorphism with strontium functionalized implants

O presente trabalho tem por objetivo caracterizar a influência de esteróides gonadais e o dimorfismo sexual na microarquitetura do tecido ósseo formado ao redor de implantes funcionalizados por estrôncio e instalados na tíbia de ratos e ratas que foram divididos em 4 grupos experimentais. Os grupos SHAM F e SHAM M foram os grupos controle, submetidos a cirurgia fictícia, nas fêmeas e machos. O grupo OVX foram as fêmeas submetidas à cirurgia de ovariectomia bilateral e os ORQ foram os machos submetidos à orquiectomia. Após 30 dias das cirurgias para remoção das gônadas ou cirurgias fictícias, os animais foram submetidos à instalação dos implantes nas tíbias, cada animal recebeu 2 implantes, sendo 1 em cada metáfise tibial. A eutanásia foi realizada aos 60 dias após a instalação dos implantes. Os ossos tibiais foram coletados e processados laboratorialmente para a análise tridimensional através da avaliação microtomográfica (Micro-Ct), também foi realizada uma análise imunoistoquímica, com objetivo de analisar as respostas celulares quanto ao processo de reabsorção óssea, remodelação e mineralização. Concluiu-se que a funcionalização com estrôncio na superfície dos implantes interferiu no processo de reparo perimplantar, resultando em tecido ósseo com diferentes características microarquiteturais, de acordo com o gênero(AU)

The present work aims to characterize the influence of gonadal steroids and sexual dimorphism on the microarchitecture of bone tissue formed around strontium functionalized implants and installed in the tibia of rats and mice that were divided into 4 experimental groups. The SHAM F and SHAM M groups were the control groups, applying the fictitious surgery, in the latter and males. The OVX group were as submitted to bilateral ovariectomy surgery and the ORQ were the males related to the orchiectomy. After 30 days of surgery to remove the gonads or fictitious surgeries, the animals were infected by installing the implants in the tibiae, each animal completes 2 implants, 1 in each tibial metaphysis. Euthanasia performed 60 days after the implant installation. Tibial bones were collected and processed in the laboratory for a three-dimensional analysis through microtomographic evaluation (Micro-Ct), an immunohistochemical analysis was also carried out, with the objective of analyzing cellular responses regarding the process of bone resorption, remodeling and mineralization. It was concluded that strontium functionalization on the surface of the implants interfered in the process of perimplant repair, termination in bone tissue with different microarchitectural characteristics, according to gender(AU)

Caracterização e avaliação randomizada de superfícies de liga de titânio modificada por hidroxiapatita e hidroxiapatita incorporada com estrôncio em ratas saudáveis e osteoporóticas / Characterization and randomized evaluation of titanium alloy surfaces modified by hydroxyapatite and hydroxyapatite incorporated with strontium in healthy and osteoporotic female rats

Este estudo objetivou caracterizar os tratamentos de superfície com hidroxiapatita e hidroxiapatita modificada por estrôncio em duas concentrações (10 e 90%) sobre superfícies de liga de titânio, e avaliar a sua osseointegração em tíbias de ratas saudáveis e osteoporóticas. Foram utilizados parafusos de fixação e discos de liga de titânio, que foram divididos em grupos de acordo com a superfície: Usinada, Hap, HapSr 10% e HapSr 90%. Os tratamentos de superfícies foram realizados pelo método biomimético. Foi avaliado a morfologia, estrutura, composição química, molhabilidade, energia de superfície e integridade das superfícies. As superfícies também foram testadas in vivo, na qual os parafusos foram randomizados e instalados em tíbias de ratas saudáveis (controle) e osteoporóticas (OVX). A osseointegração foi avaliada pelo torque reverso, área de fluorocromos calceína e alizarina, área de contato entre tecido ósseo e parafuso e extensão linear de contato entre osso e parafuso 60 dias após a instalação. Nas análises laboratoriais observaram-se nas superfícies Hap, HapSr10% e HapSr90% filmes finos rugosos e presença de poros em escala nanométrica, presença de grupos químicos de Hap semelhante à do tecido ósseo, e aumento expressivo da molhabilidade e da energia de superfície. Nas análises in vivo de torque reverso, no grupo OVX os valores foram mais significativos para as superfícies contendo estrôncio (HapSr 10% e HapSr90%), enquanto no grupo controle a superfície de Hap apresentou maior torque para remoção do parafuso. A área de fluorocromos para calceína e a área óssea neoformada foi expressivamente maior na superfície de HapSr 10% do grupo controle. Em conclusão, as superfícies tratadas com as hidroxiapatitas melhoram a morfologia, composição e a reatividade da superfície, e apresentam um efeito promissor na osseointegração de parafusos em tíbias de ratas saudáveis e osteoporóticos(AU)

The objective of this study was to characterize the surface treatments with hydroxyapatite and hydroxyapatite modified by strontium in two concentrations (10 and 90%) on titanium alloy surfaces, and to evaluate their osseointegration in tibias of healthy and osteoporotic rats. Fixing screws and titanium alloy discs were used, which were divided into groups according to the surface: Machined, Hap, HapSr 10% and HapSr 90%. The surface treatments were carried out by the biomimetic method. The morphology, structure, chemical composition, wettability, free surface energy and surface integrity were evaluated. The surfaces were also tested in vivo, in which the screws were randomized and installed in the tibias of healthy (control) and osteoporotic (OVX) rats. Osseointegration was evaluated by reverse torque, area of fluorochromes calcein and alizarin, area of contact between bone tissue and screw and linear extent of contact between bone and screw 60 days after placement. Laboratory analyzes showed that Hap, HapSr10% and HapSr90% had thin, rough films and the presence of pores on a nanometer scale, the presence of Hap chemical groups similar to that of bone tissue, and a significant increase in wettability and surface energy. In the in vivo analyzes of reverse torque, in the OVX group the values were more significant for strontium-containing surfaces (HapSr 10% and HapSr90%), while in the control group the Hap surface showed greater torque for removing the screw. The fluorochromic area for calcein and the newly formed bone area were significantly greater on the HapSr 10% surface of the control group. In conclusion, surfaces treated with hydroxyapatites improve surface morphology, composition, and reactivity, and have a promoting effect on screw osseointegration in healthy and osteoporotic female rats(AU)

Desenvolvimento, caracterização e avaliação in vitro de cimento ósseo à base de nano hidroxiapatitas substituídas com magnésio, estrôncio e zinco / Development, characterization and in vitro evaluation of bone cement based on nano-hydroxyapatites substituted with magnesium, strontium and zinc

A incorporação de íons na estrutura da hidroxiapatita (HA) pode afetar sua estrutura, cristalinidade, solubilidade e citotoxicidade. Dentre os íons presentes na composição da apatita óssea, o magnésio (Mg2+), estrôncio (Sr2+) e zinco (Zn2+) são reconhecidos por promover a angiogênese e osteogênese. Portanto, as HAs substituídas podem apresentar melhor bioatividade, por fornecer íons com potencial de estimular a neoformação óssea nos locais enxertados. Nesse contexto, este estudo descreve a síntese, caracterização e comparação de uma série de nano-hidroxiapatitas (nHAs) substituídas e co-substituídas por Sr2+, Mg2+ ou Zn2+. Em seguida, foi desenvolvido um cimento ósseo à base das HAs com melhores resultados de citotoxicidade, associado ao DCPA, gelatina e quitosana. As nHAs foram caracterizadas físico-quimicamente usando diferentes técnicas. O método de co-precipitação foi eficaz para sintetizar HAs de dimensões nanométricas. Comparado a nHA pura, os difratogramas, espectros de FTIR e parâmetros de rede das nHAs substituídas e co-substituídas exibiram alterações, indicando que a incorporação de cátions resultou em distorções da rede da HA. Os testes de MTT demonstraram que as nHAs sintetizadas não foram citotóxicas, após contato direto com culturas de fibroblastos (L929) e pré-osteoblastos (MC3T3). Os resultados obtidos sugerem que as nHAs co-substituídas por Mg2+/Sr2+ e Zn2+/Sr2+ parecem induzir maior proliferação de células fibroblásticas e osteoblásticas, quando comparado a HA pura e substituída. Os cimentos ósseos desenvolvidos apresentaram capacidade de auto-endurecimento e resistência à lavagem. Além de possuírem alta molhabilidade e um perfil de liberação de íons Ca2+, Sr2+, Mg2+ e Zn2+, que está dentro das doses indicadas para estimular a proliferação de osteoblastos. Os cimentos exibiram excelente biocompatibilidade in vitro em culturas de células fibroblásticas, endoteliais e osteosblásticas. Os cimentos contendo nHAs co-substituídas por Mg2+/Sr2+ exibiram os melhores resultados de viabilidade celular. Após 24 horas de contato indireto com cultura de células fibroblásticas L929, o crescimento celular do grupo C2 foi maior que de todos os grupos em estudo (P < 0,01). Em cultura de células endoteliais EA.hy926, o percentual de células viáveis do grupo C3 foi significativamente maior que de todos os outros grupos, após 24 horas (p < 0,001). A citotoxicidade indireta em cultura de células pré-osteoblásticas MC3T3 revelou que após 48 horas, o grupo C3 apresentou maior viabilidade celular que todos os grupos em estudo (p < 0,01). O teste de formação de tubo sugere que todos os cimentos desenvolvidos possuem potencial angiogênico, sendo que os cimentos contendo nHAs co-substituídas por Zn2+/Sr2+ exibiram resultados significativamente superiores (p < 0,001). Apesar de ser necessário um maior número de testes de biocompatibilidade; a incorporação de íons na rede cristalina das nHAs, que são reconhecidos por afetar a angiogênese e a osteogênese, parece ter resultado no desenvolvimento de cimentos ósseos com potencial para promover a regeneração óssea.

The incorporation of ions into the HA lattice can affect its structure, crystallinity, solubility and cytotoxicity. From the ions present in the composition of bone apatite, Mg2+, Sr2+ and Zn2+ are recognized for promoting angiogenesis and osteogenesis. The substituted HAs can be present better bioactivity for supplying ions with potential to stimulate bone neoformation in grafted sites. This study described the synthesis, characterization and comparison of a range of substituted and co-substituted nHAs contained Sr2+, Mg2+ or Zn2+. Then, it developed bone cement based on HAs with better cytotoxicity results, associated with DCPA, gelatin and chitosan. The nHAs were physicochemically characterized using different techniques. The co-precipitation method was effective for synthesizing HAs with nanometric dimensions. Compared to pure nHA, the diffractograms, FTIR spectra and lattice parameters of the substituted and co-substituted nHAs showed changes, indicating that the incorporation of cations resulted in distortions of the HA lattice. MTT tests demonstrated that the all synthesized nHAs were not cytotoxic after direct contact with fibroblasts (L929) and pre-osteoblasts (MC3T3) cultures. MTT results suggest that Mg2+/Sr2+ and Zn2+/Sr2+ co-substituted nHAs seem to induce more proliferation of fibroblastic and osteoblastic than pure and Mg2+, Sr2+ and Zn2+ substituted nHAs. Bone cements developed showed self-hardening and washout resistance. Also, they Exhibited high wettability and ion release profile with non-toxic concentrations of Ca2+, Sr2+, Mg2+ and Zn2+, range within indicated doses to stimulate the proliferation of osteoblasts. The cement exhibited excellent in vitro cytocompatibility in fibroblastic, endothelial and osteoblastic cell cultures. Cement containing Mg2+/Sr2+ co-substituted nHAs showed better results of the cell viability. After 24 hours of indirect contact with L929 fibroblast culture, the cell growth in the C2 group was highest than all study groups (P <0.01). In EA.hy926 endothelial culture, the cell viability of the C3 group was significantly highest than all other groups after 24 hours (p <0.001). The indirect cytotoxicity in MC3T3 pre-osteoblastic culture revealed that after 48 hours, the C3 group showed the greatest cell viability than all the study groups (p <0.01). The tube formation assay suggests that all cement have angiogenic potential, being that the cements containing Zn2+ / Sr2+ co-substituted nHAs exhibited significantly better results (p < 0,001). Despite being necessary to perform a more significant number of biocompatibility tests, the incorporation of ions into the nHA lattice, which are recognized for affects angiogenesis and osteogenesis, may have resulted in the development of bone cements with the potential to promoting bone regeneration.

Efectos del ranelato de estroncio sobre la densidad mineral ósea en hombres / Effect of strontium ranelate on bone mineral density in men

La osteoporosis afecta al 6-7% de la poblaciónmasculina. Es alta la proporción de pacientes confractura osteoporótica sin diagnóstico previo de estaenfermedad. La mortalidad luego de una fracturaes mayor en hombres que en población femenina;a pesar de esto, la mayoría de los pacientes no reciben tratamiento. Los fármacos aprobados, en nuestro medio, para tratar la osteoporosis masculina son:bifosfonatos, teriparatida y ranelato de estroncio. Elobjetivo de este estudio fue evaluar el efecto del ranelato de estroncio sobre la densidad mineral ósea enhombres después de 1 año de tratamiento. Se incluyeron los registros de 20 hombres de 67.8±3.0 años,tratados con ranelato de estroncio (2 g/día) durante 1año. Todos los pacientes presentaban un T-score inferior a -2.5 en cadera o columna vertebral o un T-scoreinferior a -2.0 y factores de riesgo de fractura. Nohubo modificación de parámetros de laboratorio luego del tratamiento (calcemia, calciuria, fósforo sérico,parathormona, 25(OH)vitamina D, fosfatasa alcalinay desoxipiridinolina). Luego de 1 año de tratamiento con ranelato de estroncio se observó incrementode la densidad mineral ósea en columna lumbar:0.953±0.029 versus 0.997±0.030 g/cm2 (p=0.0068),cuello femoral: 0.734±0.013 versus 0.764±0.016 g/cm2 (p=0.0084) y cadera total: 0.821±0.02 versus0.834±0.02 g/cm2 (p=0.0419). Conclusión: luego de1 año de tratamiento el ranelato de estroncio produjoun incremento significativo de la densidad mineralósea en columna lumbar y fémur proximal en hombres con osteoporosis (AU)

Osteoporosis affects 6-7% of the male population. The proportion of patients with fragility fractures but without diagnosis of the disease is high. Mortality after hip fracture is higherin men than in women; in spite of this, mostpatients are left without treatment for osteoporosis. Drugs approved, for the treatment ofosteoporosis in our country are bisphosphonates, teriparatide, and strontium ranelate (SrR).The objective of this study was to evaluate theeffect of SrR on axial BMD in men after one yearof treatment. We obtained pertinent data frommedical registries of 20 men aged 67,8±3,0 years,treated with oral SrR (2 g/day) for 12 months. All patients had a T-score below -2,5 at the hipor the lumbar spine, or a T-score below -2,0and one or more risk factors for fracture. Thelevels of serum calcium, phosphate, alkalinephosphatase, 25-hydroxyvitamin D, or PTH,or urinary calcium and desoxipyridinoline remained unchanged following SrR administration. After treatment with SrR there weresignificant increases in BMD at the lumbarspine: 0,953±0,029 versus 0,997±0,030 g/cm2(p=0,0068), femoral neck: 0,734±0,013 versus 0,764±0,016 g/cm2 (p=0.0084), and total hip: 0,821±0,02 versus 0,834±0,02 g/cm2(p=0,0419). Conclusion: in osteoporotic men,treatment with SrR significantly increases BMDin the lumbar spine and the proximal femur (AU)

Gamow-Teller β+ decay properties of A=98 isobars near 100Sn doubly magic core / Propiedades de la desintegración β+ de Gamow-Teller de isóbaros con A = 98 cercanos al núcleo 100Sn doblemente mágico

Abstract In this work, we have realized some spectroscopic calculations in the framework of the nuclear shell model, in order to estimate the Gamow-teller (GT) β+decay of A=98 proton rich isobars in 100Sn mass region near rp-process path. The calculations are carried out by means of Oxbash nuclear structure code, taking into account the monopole effect in the studied mass region. The obtained results are then compared to the available experimental data.

Resumen En este trabajo hemos realizado algunos cálculos espectroscópicos en el marco de trabajo del modelo nuclear de capas para estimar la desintegración β+ de Gamow-Teller (GT) de isóbaros ricos en protones con A = 98 en la región de masa 100Sn, cerca del camino del proceso rp. Los cálculos se llevan a cabo mediante el código de estructura nuclear de Oxbash, teniendo en cuenta el efecto monopolo en la región de masa estudiada. Los resultados obtenidos se comparan luego con los datos experimentales disponibles.

β+ decay properties of A=100 isobars / Propiedades de la desintegración β+ de isóbaros con A = 100

Abstract The estimation of spectroscopic properties of neutron-deficient nuclei in the A=100 tin mass region is needed for the understanding of the rp-process path and the experimental exploration of the nuclear landscape. In order to evaluate some spectroscopic properties of the Gamow-Teller β +decay of neutron deficient isobars of A=100, we have performed shell model calculations by means of Oxbash nuclear structure code. The jj45pn valence space used consists of nine proton and neutron orbitals. The calculations included few valence hole-proton and particle-neutronin πg9/2 and vg7/2 orbitals respectively, in 100Sn doubly magic core. Effective interaction deduced from CD-Bonn one is introduced taking into account the nuclear monopole effect in this mass region. The results are then compared with the available experimental data.

Resumen La estimación de las propiedadesespectroscópicas de los núcleosdeficientes en neutrones en la región de masas de estaño A = 100 es necesaria para la comprensióndelcaminodelproceso rp y la exploraciónexperimental de laestructura interna de los núcleos. Con el fin de evaluar algunas propiedades espectroscópicas de la desintegración β+de Gamow-Teller en los isótopos de estañodeficientes en neutrones con A = 100, hemosrealizadocálculosdelmodelo de capas mediante el código de estructuranuclear de Oxbash. El espacio de valencia jj45pn utilizado consiste en nueve orbitales de protones y neutrones. Los cálculosincluyeronpocoshueco-protóny partícula-neutrón de valencia en orbitales πg9/2 y vg7/2respectivamente, en un núcleo100Sn doblementemágico. La interacciónefectivadeducida de CD-Bonn se introduceteniendo en cuenta el efectomonopolarnuclear en estaregión de masa. Los resultados se comparanluego con los datosexperimentales disponibles.

Effects of strontium ranelate on alveolar ridge morphology augmentation / Efectos del ranelato de estroncio en el aumento del rebforde alveolar

SUMMARY: The objective of this study was to compare the Primary and Secondary stability of immediate implant placement with Alveolar Ridge Augmentation (ARA) and Strontium Ranelate (SR) as aids to enhance the stability using Resonance Frequency Analysis (RFA). Fifty eight subjects ideal for immediate implants were assigned to two groups to compare the primary and secondary stability of the implant using Alveolar Ridge Augmentation and oral strontium ranelate. They were tested for primary stability on placement of the implant and after eight weeks of placement for secondary stability. The stability was measured using resonance frequency analysis. Both the procedures showed an improvement in the stability but the Alveolar Ridge Augmentation procedure showed a significantly better primary stability (P< .03) and the secondary stability (P<.00). The means of the implant stability quotient value (ISQ) for the Alveolar ridge augmentation procedure was 74.2 for primary stability, and 83.34 for secondary stability. With the enhancement of stability with both the procedures Alveolar Ridge Augmentation proved to be a better procedure to achieve successful results of an immediately placed implant.

RESUMEN: El objetivo de este estudio fue comparar la estabilidad primaria y secundaria de la colocación inmediata del implante con el aumento de reborde alveolar (ARA) y el ranelato de estroncio (SR) como ayudas para mejorar la estabilidad mediante el análisis de frecuencia de resonancia (RFA). Cincuenta y ocho sujetos, ideales para implantes inmediatos, fueron asignados a dos grupos para comparar las estabilidades primaria y secundaria del implante usando el aumento del reborde alveolar y el ranelato de estroncio oral. Se efectuaron pruebas de estabilidad primaria en la colocación del implante, y después de ocho semanas para la estabilidad secundaria. La estabilidad se midió utilizando análisis de frecuencia de resonancia. Ambos procedimientos mostraron una mejora en la estabilidad, sin embargo el procedimiento del aumento del reborde alveolar mostró una estabilidad primaria significativamente mejor (P <0,03) que la estabilidad secundaria (P <0,00). Las medias del valor de cociente de estabilidad del implante (ISQ) para el procedimiento de aumento de reborde alveolar fueron 74,2 para la estabilidad primaria y 83,34 para la estabilidad secundaria. Se observó una mejora de la estabilidad en ambos procedimientos, el aumento del reborde alveolar demostró ser un mejor procedimiento para lograr resultados exitosos del posicionamiento de implante inmediato.

Efecto del ranelato de estroncio sobre la densidad mineral ósea en hombres con osteoporosis / Effect of strontium ranelate on bone mineral density in men with osteoporosis

La osteoporosis afecta al 6-7% de la población masculina. Es alta la proporción de pacientes con fracturas sin diagnóstico previo de esta enfermedad. La mortalidad luego de una fractura es mayor en hombres que en población femenina; a pesar de esto, la mayoría de los pacientes no reciben tratamiento. Los fármacos aprobados, en nuestro medio, para tratar la osteoporosis masculina son: bifosfonatos, teriparatida y ranelato de estroncio. El objetivo de este estudio fue evaluar el efecto del ranelato de estroncio sobre la densidad mineral ósea en hombres después de 1 año de tratamiento. Se incluyeron los registros de 20 hombres de 67,8±3,0 años, tratados con ranelato de estroncio (2 g/día) durante 1 año. Todos los pacientes presentaban un T-score inferior a -2,5 en cadera o columna vertebral o un T-score inferior a -2,0 y factores de riesgo de fractura. No hubo modificación de parámetros de laboratorio luego del tratamiento (calcemia, calciuria, fósforo sérico, parathormona, 25(OH)vitamina D, fosfatasa alcalina y desoxipiridinolina) en relación a los basales. Luego del tratamiento con ranelato de estroncio se observó incremento de la densidad mineral ósea en columna lumbar: 0,953±0,029 versus 0,997±0,030 g/cm2 (p=0,0068), cuello femoral: 0,734±0,013 versus 0,764±0,016 g/cm2 (p=0,0084) y cadera total: 0,821±0,02 versus 0,834±0,02 g/cm2 (p=0,0419). Conclusión: el tratamiento con ranelato de estroncio produjo un incremento significativo de la densidad mineral ósea en columna lumbar y fémur proximal en hombres con osteoporosis. (AU)

Osteoporosis affects 6-7% of the male population. The proportion of patients with fragility fractures but without diagnosis of the disease is high. Mortality after hip fracture is higher in men than in women; in spite of this, most patients are left without treatment for osteoporosis. Drugs approved, for the treatment of osteoporosis in our country are bisphosphonates, teriparatide, and strontium ranelate (SrR). The objective of this study was to evaluate the effect of SrR on axial BMD in men after one year of treatment. We obtained pertinent data from medical registries of 20 men aged 67,8±3,0 years, treated with oral SrR (2 g/day) for 12 months. All patients had a T-score below -2,5 at the hip or the lumbar spine, or a T-score below -2,0 and one or more risk factors for fracture. The levels of serum calcium, phosphate, alkaline phosphatase, 25-hydroxyvitamin D, or PTH, or urinary calcium and desoxipyridinoline remained unchanged following SrR administration. After treatment with SrR there were significant increases in BMD at the lumbar spine: 0,953±0,029 versus 0,997±0,030 g/cm2 (p=0,0068), femoral neck: 0,734±0,013 versus 0,764±0,016 g/cm2 (p=0.0084), and total hip: 0,821±0,02 versus 0,834±0,02 g/cm2 (p=0,0419). Conclusion: in osteoporotic men, treatment with SrR significantly increases BMD in the lumbar spine and the proximal femur. (AU)

Evaluación de la respuesta densitométrica en pacientes con osteoporosis posmenopáusica tratadas con ranelato de estroncio o denosumab / Densitometric response in postmenopausal osteoporosis treated with strontium ranelate or denosumab

Tanto el ranelato de estroncio (RSr) como el denosumab (Dmab) son eficaces en el tratamiento de la osteoporosis (OP) posmenopáusica (PM). El efecto de cada fármaco por separado sobre la densidad mineral ósea (DMO) ha sido estudiado recientemente. Con ambas drogas se observó, al año de tratamiento, un aumento significativo de la DMO en columna lumbar (CL), cuello femoral (CF) y cadera total (CT). En este trabajo comparamos la respuesta densitométrica al año de tratamiento con una y otra droga. Utilizamos los registros de 425 pacientes PMOP tratadas con Dmab y 441 tratadas con RSr. En cada paciente analizamos el porcentaje de cambio; se clasificaron como respondedoras aquellas que mostraron un cambio ≥3%. Adicionalmente se comparó la respuesta en pacientes no previamente tratadas con bifosfonatos (BF-naïve) en comparación con pacientes que habían recibido previamente un BF. Al analizar el grupo completo para Dmab, el porcentaje de pacientes respondedoras fue de 68,4% en CL, 63,3% en CF y 49,3% en CT. Por otro lado, en el grupo de pacientes tratadas con RSr, el porcentaje de respondedoras (53,8% en CL, 40,0% en CF y 35,6% en CT) fue estadísticamente menor. Cuando comparamos la respuesta entre las pacientes BF-naïve que recibieron RSr o Dmab, el Dmab indujo mayor respuesta en CL y CF que el grupo RSr, sin diferencias en CT. Cuando se analizaron los subgrupos BF-previo, las tratadas con Dmab mostraron mayor respuesta en todas las regiones. Conclusión: en pacientes con OP-PM, el tratamiento con Dmab produjo mayores incrementos densitométricos que el RSr, siendo el porcentaje de pacientes respondedoras mayor con Dmab que con RSr. (AU)

Both strontium ranelate (SrR) and denosumab (Dmab) are effective in the treatment of postmenopausal osteoporosis (PMOP). The effect of each drug on bone mineral density (BMD) has been studied separately by us. With both treatments, there was a significant increase after one year of treatment at the lumbar spine (LS) and hip. In this paper we compared the densitometric response after one year of treatment with both drugs used separately. We used the clinical records of 425 PM patients treated with Dmab and 441 treated with SrR. For each patient we analyzed the percentage of change; those who showed a change ≥3% were classified as responders. Additionally, the response was compared in patients not previously treated with bisphosphonates (BP-naïve) compared to patients who had previously received a BP. When analyzing the complete group for Dmab, the percentage of "responders" was 65.2% at the LS, 62.9% at the femoral neck (FN) and 47.4% at the total hip (TH). On the other hand, in the group of patients treated with SrR the percentage of responders (53.8% at the LS, 40.0% at the FN and 35.6% at the TH) was statistically lower. When comparing the response between in BF-naïve patients receiving RSr or Dmab, Dmab induced a greater response at the LS and FN than the RSr group, with no statistical differences at the TH. When the subgroups with prior BP treatment were analyzed, those treated with Dmab showed greater response in all regions. Conclusion: in patients with PMOP treatment with Dmab produced greater densitometric increments than SrR, and the percentage of responders was higher with Dmab than with SrR. (AU)

Drogas promissoras na reparação óssea periodontal: sinvastatina, ranelato de estrôncio e alendronato de sódio / Promissing drugs for periodontal bone regeneration: simvastatin, strontium ranelate, and sodium alendronate

O tratamento de defeitos ósseos intrabucais tem sido um desafi o na área odontológica, e a pesquisa de novas drogas para otimizar os resultados cirúrgicos regenerativos é de extrema importância. Existem evidências de que algumas drogas, como o ranelato de estrôncio (RSr), a sinvastatina (SNV) e o alendronato de sódio (ALE), têm propriedades anabólicas no metabolismo ósseo. A proposta desta revisão foi apresentar o estado atual da arte sobre o emprego da SNV, do RSr e do ALE em terapias odontológicas. Foi realizada uma busca bibliográfica na base PubMed e incluídos estudos relevantes relacionados ao tema para síntese deste trabalho. Concluiu-se que a aplicação do ALE e da SIN são efetivos como coadjuvantes no tratamento mêcanico da doença periodontal e como indutores de neoformação óssea, entretanto, o RSr merece ser mais bem estudado para tal afirmação.

The treatment of intraoral bone defects has been a challenge in dentistry, in this way the development of new drugs in order to optimize surgical regenerative results are extreme important. There are evidences that drugs such as strontium ranelate (RSr), simvastatin (SNV) and sodium alendronate (ALE) have anabolic properties in bone metabolism and several studies have been performed aiming to improve therapeutic strategies in bone regeneration. Therefore, the purpose of this review is to present the current state of art about the usage of SNV, RSr and ALE in dental therapies, targeting better clinical outcomes in bone manipulation techniques. A literature research was performed in PubMed database and relevant studies between were included. Our study concluded that application of ALE and SNV are effective as adjuncts with mechanical therapy of periodontal disease and also induces bone formation. In the other hand, the application of RSr as a promising bone formation drug needs to be better elucidated.

Efectos in vivo del ranelato de estroncio sobre células progenitoras de médula ósea de ratas diabéticas / In vivo effects of strontium ranelate on bone marrow progenitor cells of diabetic rats

La diabetes mellitus (DM) crónica se asocia con reducción en el contenido mineral óseo (osteopenia y osteoporosis). El objetivo de este trabajo fue evaluar la acción del ranelato de estroncio (RaSr) administrado por vía oral a animales control y diabéticos, sobre el potencial osteogénico de células progenitoras de médula ósea (CPMO). Dieciséis ratas Wistar macho jóvenes se dividieron en dos grupos: controles (C) y diabéticas (D) con destrucción parcial de células b-pancreáticas mediante inyecciones intraperitoneales consecutivas de nicotinamida y estreptozotocina. Siete días después de la inyección, cada grupo se subdividió: sin tratamiento, o tratadas oralmente con RaSr (625 mg/kg/día) durante seis semanas, luego de lo cual los animales fueron sacrificados. Las CPMO se obtuvieron de ratas de los cuatro grupos, por lavados del canal diafisario medular (húmero o fémur o ambos) y cultivo hasta confluencia en DMEM-10% FBS. La proliferación celular se evaluó mediante el ensayo de MTT. Luego las CPMO se replaquearon e incubaron en un medio osteogénico durante 14 días (fosfatasa alcalina [FAL] y colágeno tipo 1) o 21 días (mineralización). Las CPMO del grupo C+RaSr mostraron un aumento significativo versus control en la proliferación (133%) y en la diferenciación osteogénica (colágeno 143%, FAL 168%, mineralización 117%). La DM (grupo D) disminuyó significativamente la proliferación y diferenciación osteoblástica de las CPMO. El tratamiento con RaSr (grupo D+RaSr) previno completamente estos efectos antiosteogénicos de la DM. Así, en nuestro modelo experimental in vivo, la DM disminuye el potencial osteogénico de CPMO, efecto que puede ser prevenido por un tratamiento oral con RaSr. (AU)

Chronic diabetes mellitus (DM) is associated with a reduction in bone mineral content (osteopenia and osteoporosis). The object of this study was to evaluate the in vivo effect of he anti-osteoporotic drug strontium ranelate (SrRa) administered orally to control and diabetic animals, on the osteogenic potential of bone marrow progenitor cells (BMPC). Sixteen young male Wistar rats were divided into two groups: control (C) and diabetic with partial beta-cell destruction via consecutive intra-peritoneal injections of nicotinamide and streptozotocin (D). Seven days postinjection, each group was sub-divided: without treatment, or oral treatment with SrRa (625 mg/kg/day) for six weeks, after which the animals were euthanised (groups C, C+SrRa, D, D+SrRa). BMPC were obtained from rats of all four groups by flushing of the diaphysary canal (humerus and/or femur). Adherent cells were then cultured until confluence in DMEM10% FBS. Cell proliferation was evaluated with the MTT mitogenic bioassay. BMPC were replated and incubated in an osteogenic medium for 14 days (determination of alkaline phosphatase [ALP] and type-1 collagen) or 21 days (evaluation of mineralisation). BMPC from C+SrRa rats showed a significant increase versus control in proliferation (133%) and in osteogenic differentiation (collagen 143%, ALP 168%, mineralisation 117%). Induction of diabetes (group D) significantly decreased the proliferation and osteoblastic differentiation of BMPC. Treatment of diabetic animals with SrRa (group D+SrRa) completely prevented these anti-osteogenic effects of Diabetes. Thus, in our experimental in vivo model, Diabetes decreases the osteogenic potential of BMPC, an effect that can be prevented by oral treatment with strontium ranelate. (AU)

Sequential administration of alendronate and strontium ranelate: histomorphometry and bone biomechanics in ovariectomized animals

Bisphosphonates are the first choice therapy for the pharmaco logical treatment of osteoporosis. Following reports of cases of bisphosphonaterelated osteonecrosis of the jaw and atypical femur fracture, the safety of longterm use of bisphosphonates has been evaluated, resulting in the proposal of strontium as an alternative drug. No experimental study using a sequential administration design has been reported to date. Hence, the aim of this study was to evaluate the effect on bone tissue of ovariectomized rats of administration of alendronate followed by strontium ranelate. Fortyeight female Wistar rats were ovariectomized on day 1 of the experiment. Beginning on day 30, they were administered 0.3 mg/kg/week of alendronate (ALN) or vehicle (VEH) for 8 weeks. Two groups (ALN and corresponding control) were euthanized at this time, and the remaining animals were divided into 4 groups and given 290 mg/kg/day of strontium ranelate (SR) in their drinking water (TW) or only water for 4 months. Experimental groups were: ALN+SR, ALN+TW, VEH+SR, VEH+TW, ALN and VEH. The tibiae and hemimandibles were resected for histomorphometric evaluation, and the right femur was used to perform biomechanical studies. ANOVA and Bonferroni test were applied. Diaphyseal stiffness, maximum elastic load and fracture load increased in animals that received alendronate, regardless of whether or not they received subsequent SR treatment. Fracture load also increased in VEH+ SR versus control (VEH+TW). Subchondral and interradicular bone volumes were significantly higher in animals that received ALN than in those that received vehicle. No difference was observed in cortical area or thickness of the tibia among treatments. The results obtained with the model presented here, evaluating tibial and mandibular interradicular bone, showed that the combination of ALN and SR and administration of ALN alone are equally effective in preventing bone loss associated with ovariectomyinduced estrogen depletion.

Si bien la primera opción terapéutica para el tratamiento farmacológico de la osteoporosis son los bisfosfonatos (BPs), luego de los primeros reportes en 2003 de los casos de osteone crosis de mandíbula asociada al uso de dichas drogas y las fracturas atípicas de fémur, se ha evaluado su seguridad a largo plazo. Además, en aquellos pacientes que no responden al tratamiento con BPs y mantienen elevado el riesgo de fractura, es necesario suspender su administración y alternar con otras drogas. Una de las que se ha utilizado en la clínica luego del tratamiento con BPs es el ranelato de estroncio (SR). Existen varios trabajos clínicos que reportan los efectos de la administra ción secuencial de ambas drogas, aunque estudios experi men tales con un diseño secuencial aun no se han reportado. Por ello el objetivo de este trabajo ha sido evaluar el efecto de la administración secuencial de alendronato, seguido de ranelato de estroncio sobre el tejido óseo de ratas ovariectomizadas. Se utilizaron 48 ratas Wistar hembras de dos meses de edad divididas en 6 grupos de 8 animales cada uno. El día 1 de experiencia todas fueron ovariectomizadas. El día 30 se comenzó con la administración de alendronato (ALN) en una dosis de 0.3 mg/kg/semana o vehículo (VEH) durante 8 semanas. Luego de este período se sacrificaron dos grupos (uno que recibió ALN y su correspondiente control (sólo vehículo). Los cuatro grupos restantes continuaron con ranelato de estroncio (SR) en el agua de bebida durante 4 meses en una dosis de 290 mg/kg/día o sólo agua corriente( TW) Luego de ese período fueron eutanasiados. Así, los grupos experimentales conformados fueron: ALN+SR, ALN+TW, VEH+SR, VEH+TW, ALN y VEH. Para los estudios histomorfométricos se extrajeron ambas tibias y hemimandíbulas; para el estudio biomecánico se utilizó el fémur derecho. Los resultados fueron analizados mediante el test de ANOVA y el test de Bonferroni. Incrementaron significativamente la rigidez diafisaria, la carga elástica límite y la carga de fractura aquellos grupos que recibieron alendronato versus aquellos que no lo recibieron, independientemente del tratamiento posterior con SR. La carga de fractura además fue mayor en el grupo VEH+SR versus el control (VEH+TW). En cuanto al volumen óseo subcondral e interradicular evaluado histomorfométricamente fue significativamente mayor en aquellos animales que recibieron ALN versus aquellos que recibieron vehículo. No se detectaron diferencias entre aquellos grupos que recibieron SR y sus controles. El área y espesor cortical de la tibia no mostraron diferencias entre grupos. Los resultados obtenidos en el modelo estudiado tanto a nivel del volumen óseo subcondral y cortical de la tibia como a nivel del hueso interradicular del maxilar inferior, mostraron que la combinación de ALN con SR y la administración aislada de ALN son igualmente efectivas para prevenir la pérdida ósea causada por la depleción estrogénica de la ovariectomía.

Avaliação do reparo ósseo no levantamento do seio maxilar de coelhos após implantação de esferas de hidroxiapatita carbonatada nanoestruturada contendo 5% de estrôncio / Evaluation of bone repair after maxillary sinus grafting with 5% strontium, nanostructured, carbonated hydroxyapatite microspheres in a rabbit model

A hidroxiapatita (HA) tem sido amplamente utilizada como um importante substituto ósseo. Quando em dimensão nanométrica, assemelha-se em tamanho e morfologia à apatita biológica, podendo ser considerada um biomaterial promissor para aplicação clínica. O estrôncio contribui por atuar na redução da reabsorção óssea e indução na atividade osteoblástica, enquanto os carbonatos favorecem a bioabsorção. Objetivos: caracterizar físico-quimicamente e analisar histologicamente, e de forma comparativa, a hidroxiapatita carbonatada contendo 5% de estrôncio com a hidroxiapatita estequiométrica. Material e métodos: foram utilizados 12 coelhos brancos Nova Zelândia, divididos em: hidroxiapatita carbonatada nanoestruturada contendo 5% de estrôncio (nSrcHA-experimental) e hidroxiapatita carbonatada nanoestruturada (ncHA-controle). Após a confecção dos sítios cirúrgicos, foram implantadas nas cavidades dos seios maxilares microesferas de ncSrHA e ncHA, nos lados esquerdo e direito, respectivamente. Os animais foram eutanasiados para análise histológica após quatro e 12 semanas. Resultados: após quatro semanas, o grupo ncHA apresentou osso neoformado e pavimentação osteoblástica próximo da parede do defeito. No grupo nSrcHA, o biomaterial apresentou-se de forma difusa com uma maior deposição de matriz osteogênica em torno do biomaterial, tecido ósseo neoformado próximo das paredes e no interior dos defeitos. No período de 12 semanas o grupo ncHA exibiu biomaterial no interior do defeito e osso neoformado, enquanto no grupo nSrcHA observou-se uma intensa formação óssea no interior do defeito com presença de osteócitos. Conclusão: ambos os materiais foram biocompatíveis e osteocondutores.

Hydroxyapatite (HA) has been widely used as an important bone substitute. Its nanometer scale is similar in size and morphology of biological apatite, which can be considered a promising biomaterial for clinical application. Strontium contributes to reduce bone resorption and induces osteoblast activity, whereas the carbonates favor bio-absorption. Objectives: to perform physico-chemical and histological characterization of nanostructured carbonated hydroxyapatite containing 5% strontium and the stoichiometric hydroxyapatite. Material and methods: twelve white New Zealand rabbits were used in this study and divided into nanostructured carbonated hydroxyapatite containing 5% strontium (ncSrHA-experimental) and nanostructured carbonated hydroxyapatite (ncHA-control). Two surgical defects were created in the maxillary sinus cavities and received microspheres of ncSrHA and ncHA in the left and right sides, respectively. After the experimental periods of 4 and 12 weeks, the animals were euthanized for histological analysis. Results: after four weeks, the ncHA group showed new bone formation and osteoblastic layer near the defect wall. For ncSrHA, a diffuse, increased osteogenic matrix deposition was seen around the biomaterial, with newly formed bone near the walls and inside the defects. At 12 weeks, the ncHA group exhibited biomaterial inside the defect and new bone formation, while in the ncSrHA group an intense bone formation within the defect with presence of osteocytes was observed. Conclusion: both materials are biocompatible and osteoconductive.

Utilização sistêmica de estrôncio não radioativo como potencializador da osseointegração de implantes: avaliação biomecânica, microtomográfica e histomorfométrica em ratos / Use of non-radioactive strontium systemic as a potentiator of osseointegration of implants. Evaluation biomechanics, microtomographic and histomorphometry in rats

Medicamentos a base de bisfosfonatos têm sido amplamente empregados para tratar enfermidades como osteoporose, mieloma múltiplo, doenças reumáticas e neoplasias com metástases ósseas. No entanto, não podem ser usados rotineiramente na clínica odontológica em favor da maior reparação óssea e osseointegração devido a seus mecanismos específicos e por estarem constantemente relacionados a problemas como alta permanência da droga no organismo e risco de necroses ósseas. Medicamentos a base de estrôncio surgem como novas formas de tratamento para pacientes osteoporóticos bem como uma possível indicação para o uso coadjuvante em procedimentos cirúrgicos, favorecendo a nova formação óssea. Diante das vantagens oferecidas pelos medicamentos a base de estrôncio, como ranelato de estrôncio e cloreto de estrôncio/carbonato de estrôncio, este trabalho teve como objetivo avaliar a osseointegração de implantes em tíbias de ratos. Foram utilizados 70 ratos Rattus Norvegicus, machos, divididos aleatoriamente em 5 grupos: S-Controle (soro); RE 50 (Ranelato de Estrôncio 50 mg); RE 625 (Ranelato de Estrôncio 625 mg); ClECaE 30 (Cloreto Estrôncio e Carbonato Estrôncio 30 mg); ClECaE 365 (Cloreto Estrôncio e Carbonato de Estrôncio 365 mg). Os medicamentos foram administrados diariamente, via gavagem, de acordo com cada grupo, iniciando 15 dias antes do procedimento cirúrgico (1 implante em cada tíbia), persistindo até o final do experimento 15 ou 60 dias. Testes biomecânicos foram realizados com os implantes do lado direito através do contra-troque de remoção, e os implantes no lado esquerdo foram realizadas microtomografias e análises histomorfométricas. Os resultados mostraram uma melhora na osseointegração, principalmente nos grupos ranelato estrôncio 62mg e cloreto estrôncio/carbonato estrôncio 365mg nos testes biomecânicos e microtomográficos. O medicamento a base de estrôncio teve uma influência positiva na osseointegração dos implantes, principalmente o cloreto estrôncio/carbonato estrôncio, podendo ser incorporado a prevenção, tratamentos de patologias, bem como adjuntos a procedimentos cirúrgicos de instalação de implantes

Drugs containing bisphosphonates have been widely used to treat diseases such as osteoporosis, multiple myeloma, myeloproliferative disease and cancer with bone metastases. However, can not be used routinely in dental practice in favor of greater bone repair and osseointegration due to its specific mechanisms and are constantly related issues such as high permanence of the drug in the body and risk of bone necrosis. Drugs based on strontium emerge as new forms of treatment for osteoporotic patients as well as a possible indication for adjuvant use in surgical procedures, promoting new bone formation. Given the advantages offered by drugs containing strontium as strontium ranelate and strontium chloride/strontium carbonate , this study aimed to evaluate the osseointegration of implants in rat tibia. Were used 70 rats Rattus Norvegicus, males, randomly divided into 5 groups: S (control-serum physiologic); RE50 (Strontium Ranelate 50 mg); RE 625 (Strontium Ranelate 625 mg); ClE/CaE 30 (Strontium Carbonate and Strontium Chloride 30 mg); ClE/CaE 365 (Strontium Carbonate and Chloride Strontium 365 mg). The drugs were administered daily by gavage according to each group, starting 15 days before surgery (1 implant in each tibia) and persisted until the end of the experiment 15 or 60 days. Biomechanical tests were performed with the right implants through shift against removal, and implants in the left side microtomography and histomorphometric analysis were performed. The results showed an improvement in osseointegration, especially in groups strontium ranelate 625mg and strontium cloride/strontium carbonate 365mg in microtomography and biomechanical testing. The drug strontium base had a positive influence on osseointegration of implants, especially strontium chloride/strontium carbonate, can be incorporated into prevention, treatments of pathologies and surgical procedures as adjunct to implant placement

Tratamiento de la hipersensibilidad dentinaria post terapia periodontal, mediante el uso de dos dentífricos desensibilizantes / Dentin hypersensitivity treatment post periodontal therapy, using two desensitizing dentifrices

Objetivo: El objetivo de este estudio fue evaluar y comparar la eficacia en la reducción de la hipersensibilidad dentinaria posterior a la terapia periodontal utilizando dentífricos que contienen arginina al 8 por ciento - carbonato de calcio versus acetato de estroncio al 8 por ciento, tras una y tres semanas de uso de las pastas dentales. Materiales y Método: Estudio clínico, aleatorio, ciego y controlado con dos grupos paralelos, y tres semanas de seguimiento, en el cual el universo de trabajo fue de 20 pacientes con diagnóstico de periodontitis crónica generalizada leve o moderada y que hayan presentado hipersensibilidad dentinaria posterior a la terapia periodontal no quirúrgica en al menos un canino y/o premolar, y asociado a recesión gingival. Los pacientes fueron seleccionados aleatoriamente y se distribuyeron al azar en cada grupo de pastas dentales y fueron evaluados tras una y tres semanas de uso de los dentífricos. Se les aplicó aire proveniente de la jeringa triple del equipo dental en la zona cervical con hipersensibilidad, estandarizando la técnica. La cuantificación del dolor se realizó a través de la Escala Visual Análoga (EVA). Resultados: No hubo diferencia estadísticamente significativa entre el uso de los dentífricos que contienen arginina 8 por ciento - carbonato de calcio versus acetato de estroncio al 8 por ciento para la reducción de la hipersensibilidad dentinaria tras una y tres semanas de uso de las pastas dentales. Existió diferencia estadísticamente significativa en la reducción del dolor con el uso de ambos dentríficos a la primera y tercera semana de medición.

Aim: The aim of this clinical study was to evaluate and to compare the efficacy in reducing the dentin hypersensitivity after periodontal therapy using dentifrices which contain 8 percent arginine, calcium carbonate versus 8 percent strontium acetate, after one and three weeks of use of the dentifrices. Methods: A three-week clinical study with 20 subjects with diagnosis of slight to moderate chronic periodontitis with dental hypersensitivity after periodontal therapy, and presence of gingival recession in canines and/or premolars. Patients were randomly selected and assigned to each group and toothpastes were evaluated after one and three weeks of use. Air from a triple syringe was applied into the cervical area with hypersensitivity. The quantification of pain was performed using the Visual Analogue Scale (VAS). Results: There was not statistically significant difference between the use of the dentifrices which contain 8 percent arginine, calcium carbonate versus 8 percent strontium acetate in reducing dentin hypersensitivity after one and three weeks of use of the dentifrices. Nevertheless, there was a statistically significant difference in the reduction of pain using both dentifrices in the first and third week of measurement.

Itrio 90 como radionúclido para terapia / Ytrium 90 as a radionuclide for therapy

El 90Y es un emisor beta puro con período de semidesintegración de 64.1 horas y 2.28 MeV de energía, características apropiadas para su uso como radionúclido terapéutico. Radiofármacos de 90Y han sido efectivos en el tratamiento de diferentes enfermedades como sinovitis crónica, cáncer de hígado, dolor por metástasis óseas y tumores de origen neuroendocrino. Mención aparte merecen los resultados en el tratamiento de los linfomas no-Hodgkin, que combinan la especificidad de un anticuerpo monoclonal por el antígeno CD20 y la energía beta pura del 90Y. Aunque el período de semidesintegración del 90Y permite su transportación, se comercializa a precios elevados para una utilización sistemática o a gran escala. El hecho de que se pueda obtener a través de un generador radisotópico, basado en el equilibrio secular que se establece con el 90Sr, hace que su producción local sea atractiva, pues reduciría significativamente los costos y facilitaría su disponibilidad. En este trabajo se exponen las vías para obtener 90Y, aspectos relacionados con la calidad del producto final, sus principales aplicaciones y los resultados obtenidos en el Centro de Isótopos.

90Y is a pure beta emitter with a half-life of 64.1h and 2.28 MeV of energy, suitable properties for its use as a therapeutic radionuclide. Radiopharmaceuticals based on 90Y have been effectively used in the treatment of different diseases such as chronic synovitis, liver cancer, pain caused by bone metastases and neuroendocrine tumors. The results in the treatment of no-Hodgkin lymphoma, that combine the specificity of a monoclonal antibody for CD20 antigen and the pure beta energy of 90Y, deserve a particular distinction. Although the half-life of 90Y makes possible its transportation, it is sold at high prices for a systematic or large-scale use. The fact that 90Y can be produced through a radionuclide generator system, based on the secular equilibrium of 90Sr decaying to 90Y, is very attractive for developing a local production because the cost could be significantly reduced and 90Y availability could be guaranteed. The present work shows the ways to obtain 90Y, the aspects related to the quality of final product, the main applications and the results achieved by the Isotope Centre in this area.

Effect of strontium ranelate on bone remodeling

Osteoporosis is a disease in which the microarchitecture of bone tissue deteriorates, with consequent loss of bone mass. Strontium ranelate (SrR) is currently used for treatment of the condition. SrR may have a dual effect: anabolic (stimulating pre-osteoblast replication) and anti-catabolic (reducing osteoclastic activity). However, its mechanism of action has not yet been completely elucidated. The aim of this study is to evaluate the effect of SrR on bone remodeling in healthy Wistar rats. Two-month old female Wistar rats were administered SrR (2 g/L) in drinking water for 30 weeks. Oriented histological sections were prepared from lower jaw and tibia and stained with H&E, and the following histomorphometric parameters were evaluated: a) in interradicular bone: bone volume, and percentages of bone-formation, quiescent and bone-resorption surfaces; and b) in tibia: bone volume, total thickness of growth cartilage, thickness of hypertrophic cartilage zone and number of megakaryocytes. No significant difference was found in the parameters between the control animals and those treated with SrR. The results would therefore show that SrR does not alter the bone parameters studied in this experimental design.

La osteoporosis es una enfermedad caracterizada por el deterioro de la microarquitectura del tejido oseo y la consecuente perdida de masa osea. El ranelato de estroncio (RSr) es actualmente utilizado para su tratamiento ya que poseeria un efecto dual: anabolico (estimulando la replicacion de preosteoblastos) y anticatabolico (disminuyendo la actividad osteoclastica). Sin embargo, su mecanismo de accion aun no ha sido completamente dilucidado. El objetivo del presente trabajo es evaluar el efecto del RSr sobre la remodelacion osea en ratas Wistar sanas. Se utilizaron ratas Wistar hembras de dos meses de edad a las cuales se les administro RSr (2 gr/L) en el agua de bebida durante 30 semanas. Se realizaron cortes histologicos orientados de maxilar inferior y tibia coloreados con H&E y se evaluaron los siguientes parametros histomorfometricos: a) En hueso interradicular: volumen oseo, porcentaje de superficies en formacion, reposo y reabsorcion osea. b) En tibia: volumen oseo, espesor total del cartilago de crecimiento, espesor de la zona de cartilago hipertrofiado y numero de megacariocitos. No se observaron diferencias significativas en los parametros evaluados entre los animales control y los tratados con RSr. Por lo tanto, los resultados obtenidos indicarian que el RSr no altera los parametros oseos estudiados en el presente diseño experimental.