Enzymatic activity of bone markers on Lithobates catesbeianus (Shaw, 1802) growth during the ossification process / Atividade enzimática de marcadores ósseos no crescimento de Lithobates catesbeianus (Shaw, 1802) durante o processo de ossificação

Abstract In order to better understand the ossification processes in anurans our study was carried out on tadpoles and adults of Lithobates catesbeianus. In this sense, we characterized the kinetic properties of alkaline phosphatase with p-nitrophenylphosphatase (pNPP) and pyrophosphate (PPi) and evaluated the activities of tartrate-resistant acid phosphatase and acid phosphatase. The enzyme extracts were obtained from tadpoles and adult femurs, which were divided into epiphysis and diaphysis. After homogenization, the samples were submitted to differential centrifugation to obtain cell membranes and, further, to phospholipase C (PIPLC) treatment, to remove membrane-bound proteins anchored by phosphatidylinositol. The average of specific activity for pNPP hydrolysis (at pH 10.5) by alkaline phosphatase released by phosphatidylinositol-specific phospholipase C (PIPLC) from Bacillus cereus among different bone regions at different animal ages was 1,142.57 U.mg-1, while for PPi hydrolysis (at pH 8.0), it was 1,433.82 U.mg-1. Among the compounds tested for enzymatic activity, the one that influenced the most was EDTA, with approximately 67% of inhibition for pNPPase activity and 77% for PPase activity. In the case of kinetic parameters, the enzyme showed a "Michaelian" behavior for pNPP and PPi hydrolysis. The Km value was around 0.6mM for pNPPase activity and ranged from 0.01 to 0.11mM for PPase activity, indicating that the enzyme has a higher affinity for this substrate. The study of pNPP and PPi hydrolysis by the enzyme revealed that the optimum pH of actuation for pNPP was 10.5, while for PPi, which is considered the true substrate of alkaline phosphatase, was 8.0, close to the physiological value. The results show that regardless of the ossification type that occurs, the same enzyme or isoenzymes act on the different bone regions and different life stages of anurans. The similarity of the results of studies with other vertebrates shows that anurans can be considered excellent animal models for the study of biological calcification.

Resumo Para melhor compreender o processo de ossificação em anuros, nosso estudo foi conduzido em girinos e adultos de Lithobates catesbeianus. Nesse sentido, as propriedades cinéticas da fosfatase alcalina com p-nitrofenilfosfato (pNPP) e pirofosfato (PPi) foram caracterizadas, e as atividades enzimáticas das fosfatases ácida e ácida tartarato resistente foram avaliadas. Os extratos enzimáticos foram obtidos de fêmur de girinos e adultos, divididos em epífise e diáfise. Após a homogeneização as amostras foram submetidas à centrifugação diferencial para obter membrana celular e, em seguida, ao tratamento com fosfolipase C (PIPLC), para remover as proteínas de membrana ancoradas por fosfatidilinositol. A média da atividade específica da fosfatase alcalina, liberada pela PIPLC de Bacillus cereus, para a hidrólise de pNPP (pH 10,5) nas diferentes regiões do fêmur e idades dos animais foi de 1.142,57 U.mg-1, enquanto para a hidrólise do PPi (pH 8,0) foi de 1.433,82 U.mg-1. Entre os compostos testados para a atividade enzimática, o de maior influência foi o EDTA, inibindo aproximadamente 67% e 77% das atividades de pNPPase e PPase, respectivamente. Quanto aos parâmetros cinéticos, a enzima apresentou comportamento Michaeliano para a hidrólise dos dois substratos. O valor de Km foi de 0,6 mM para a atividade de pNPPase e variou de 0,01 a 0,11 para a atividade de PPase, indicando uma maior afinidade por esse substrato. O estudo da hidrólise de pNPP e PPi revelou que o pH ótimo aparente de atuação foi de 10,5 para o pNPP e 8,0 para o PPi, próximo ao fisiológico, sendo que esse é considerado o substrato natural da fosfatase alcalina. Os resultados demonstram que, apesar do tipo de ossificação que ocorre, a mesma enzima ou isoenzimas, atuam nos diferentes locais do osso e estágios de vida dos anuros. A similaridade dos estudos com os realizados com outros vertebrados apontam que os anuros podem ser considerados excelentes modelos animais para o estudo da calcificação biológica.

Is periostin useful as a biomarker for fibrous dysplasia? / ¿Es útil periostina como biomarcador de displasia fibrosa?

Fibrous dysplasia (FD) is an infrequent non-hereditary bone disease caused by a somatic mutation of the GNAS gene. Periostin is a novel marker that increases during tissue healing and fibrous or inflammatory diseases. We conducted an exploratory case-control study to evaluate sensitivity of periostin as a biomarker of FD. The study comprised 15 patients with FD, and healthy age- and sex-matched subjects (controls). Serum periostin levels were assessed and comparisons were established between FD patients and controls, and between patients with the monostotic and the polyostotic form of FD. No statistically significant differences in serum periostin levels were observed between the cohort of FD patients studied here and the control group (FD: 51.1±10ng/ml vs. control: 44.2±15ng/ml; p=0.15), or between the clinical forms of FD (polyostotic: 51.8±9.1ng/ml vs. monostotic: 49.6±13 ng/ml; p=0.66). A sub-analysis performed to compare serum levels of periostin in FD patients with and without a history of fractures showed no statistically significant differences [fracture patients (n=4): 41.2±17ng/ml vs. non-fracture patients (n=11): 49.9±11 ng/ml; p=0.47].Lastly, sensitivity of periostin as a biomarker of FD was analyzed, and was found to have low sensitivity to estimate disease activity [ROC curve; cut-off points: 39.625(0.867-0.467)]. To conclude, in the cohort of FD patients studied here, periostin serum levels did not differ significantly from those of the control group or between the two forms of the disease, and showed low sensitivity as a biomarker of the disease. (AU)

La displasia fibrosa (DF) es una enfermedad infrecuente del hueso, no hereditaria producida por una mutación somática del gen GNAS. Periostina (Postn) es un novedoso marcador, cuyos niveles séricos se encuentran elevados en los procesos de reparación tisular, enfermedades fibrosas o inflamatorias. Llevamos a cabo un estudio exploratorio caso-control para evaluar la sensibilidad de Postn como biomarcador de DF. Se incluyeron en el estudio 15 pacientes con DF apareados por edad y género con sujetos sanos (controles) en los cuales se evaluó los niveles séricos de Postn en pacientes con DF y controles y según forma de presentación clínica. No observamos diferencias estadísticamente significativas en los niveles séricos de Postn y el grupo control (DF: 51.1±10ng/ml vs. control: 44.2±15ng/ml; p=0.15) como así tampoco por forma clínica de DF (poliostótica: 51.8±9.1ng/ml vs. monos-tótica: 49.6±13 ng/ml; p=0.66). Posteriormente realizamos un sub-análisis para evaluar los niveles séricos de Postn en los pacientes con DF y antecedentes de fracturas no observan-do diferencias estadísticamente significativas [fracturados (n=4): 41.2±17ng/ml vs. no frac-turados (n=11): 49.9±11 ng/ml; p=0.47]. Por último analizamos la sensibilidad Postn como biomarcador de DF, mostrando este poseer escasa sensibilidad para estimar actividad de la enfermedad [curva ROC; puntos de corte: 39.625 (0.867-0.467)]. En conclusión, los ni-veles séricos de Postn en nuestra cohorte de pacientes con DF no mostraron diferencias estadísticamente significativas comparadas con el grupo control o por forma clínica de presentación, mostrando una baja sensibilidad como biomarcador de enfermedad. (AU)

Interacción del microbioma intestinal y el hueso / Interaction between the intestinal microbiome and bone

El "microbioma" no solo está constituido por los microbios, sino por todos los componen-tes que viven en el mismo hábitat conforman-do un nicho ecológico. Es decir, está conformado por los microorganismos (bacterias, hongos, protozoos, etc.), todo el espectro de moléculas producidas por ellos tales como sus componentes estructurales (ácidos nucleicos, proteínas, lípidos y glúcidos), meta-bolitos, toxinas, etc., y las moléculas producidas por el huésped. El microbioma intestinal (MI) ha emergido como un factor que tiene un gran efecto sobre la cantidad, calidad y fuerza del hueso. Las investigaciones revelan que la homeostasis ósea está ligada al micro-bioma saludable, mientras que la disbiosis (alteración en la biodiversidad microbiana) puede exacerbar la actividad osteoclástica y promover la osteoporosis. Los mecanismos potenciales involucrados en la interacción del microbioma intestinal y el hueso son la influencia del metabolismo del huésped, el mantenimiento de la integridad intestinal y regulación de la absorción de nutrientes, la regulación del eje intestino-sistema inmune y la modulación del sistema endocrino. Es decir que hay múltiples vías por las cuales el MI influye sobre el hueso, pero estos y otros mecanismos deben profundizarse más aún. También es necesario que se identifiquen y caractericen mejor los microorganismos que están asociados a las enfermedades óseas. El conocimiento de estos aspectos podría ser útil para el desarrollo de herramientas terapéuticas basadas en el MI que puedan mejorar la eficacia de los distintos tratamientos existentes. (AU)

The microbiome is not only constituted by microbes, but by all the components that live in the same habitat forming an ecological niche. It is conformed by the microorganisms ( bacteria, fungi, protozoa, etc), the entire spectrum of molecules produced by them (nucleic acids, proteins, lipid and carbohydrates, metabolites, toxins, etc) and the molecules produced by the host. The intestinal microbiome (IM) has emerged as a factor with great effects on the quantity, quality and strength of bone. The investigations reveal that bone homeostasis is linked to the healthy microbiome, while the dysbiosis (alteration in the microbial biodiversity) can exacerbate the osteoclastic activity and promote osteoporosis. The potential mechanisms involved in the interaction between IM and bone are the influence of the host metabolism, the maintenance of the intestinal integrity and regulation of the nutrient absorption, the regulation of the intestine/ immune system axis and the modulation of the endocrine system. That is, there are multiple ways through which IM influences on bone, but these and other mechanisms need to be further studied. It is also necessary to identify and characterize the microorganisms associated with the bone diseases. Knowledge of these aspects could be useful to develop therapeutical tools based on the IM that could improve the efficacy of the current treatments. (AU)

Protective effect of Sika Deer bone polypeptide extract on dexamethasone-induced osteoporosis in rats

BACKGROUND: Osteoporosis attacks approximately 10% of the population worldwide. Sika Deer (Cervus nippon), one of China's precious traditional medicinal animals, has been widely recorded in ancient Chinese medical books and claimed for centuries to have numerous medical benefits including bone strengthening. This study aimed to find the use of Sika Deer bone in treating osteoporosis according to traditional records and to investigate the protective effect of Sika Deer bone polypeptide extract on glucocorticoidinduced osteoporosis (GIOP) in rats. RESULTS: Sika Deer bone polypeptide extract could increase serum Ca2+ and BGP, decrease serum P3+, ALP, PTH, and CT, but had no effect on serum NO in rats with GIOP. The immunohistochemical iNOS results of the rats' distal femur were negative in each group. Besides the model group, the eNOS color reaction in osteoblasts was strongly positive in the other three groups. CONCLUSIONS: Sika Deer bone polypeptide extract can improve pathological changes in the microstructure and stimulate the expression of eNOS in osteoblasts. The protective effect on bone might be mediated by eNOS-dependent NO generation.

Effect of selected metals on bone tissue of the masticatory apparatus / Efectos de metales en el tejido óseo del aparato masticatorio

The masticatory apparatus is a functional unit of the human body, which is mainly responsible for speech, chewing, and swallowing. It is built of bones, joints, ligaments, teeth, and muscles. In addition, the oral cavity and its hard tissues are the first ones to be exposed to exogenous factors during feeding and breathing. The aim of the work was to review the literature of recent years on the toxicology of metals and their possible negative and sometimes positive effects on the metabolism of bones of the masticatory apparatus. In summary, metals commonly found in the environment affect the bones of the masticatory apparatus to varying degrees. Attention should be paid to the sources of individual metals in the environment and to prevent their excessive, unwanted effects on the bones of the masticatory apparatus. (AU)

El aparato masticatorio constituye una unidad funcional del cuerpo humano especializada en la regulación y coordinación de los procesos del habla, la masticación y la deglución. Está constituida por huesos, ligamentos, articulaciones, músculos y dientes. El tejido óseo de la cavidad bucal es el primero en estar expuesto a factores exógenos durante la alimentación y la respiración. El objetivo del presente trabajo es realizar una revisión de lo reportado en la literatura en los últimos años, con respecto a los efectos beneficiosos o nocivos de los metales pesados sobre el metabolismo de los huesos del aparato masticatorio. En resumen, se evidencia que los metales presentes en el medioambiente afectan a estos huesos en diferentes grados. Se debe prestar especial atención a identificar las fuentes de donde provienen estos metales, para prevenir los efectos no deseados sobre el tejido óseo masticatorio generados por una excesiva exposición a ellos. (AU)

New perspectives on traumatic bone infections / 中华创伤杂志(英文版)

In this paper, we review the results of previous studies and summarize the effects of various factors on the regulation of bone metabolism in traumatic bone infections. Infection-related bone destruction incorporates pathogens and iatrogenic factors in the process of bone resorption dominated by the skeletal and immune systems. The development of bone immunology has established a bridge of communication between the skeletal system and the immune system. Exploring the effects of pathogens, skeletal systems, immune systems, and antibacterials on bone repair in infectious conditions can help improve the treatment of these diseases.

Impacto do tratamento periodontal não cirúrgico nos níveis de biomarcadores do metabolismo ósseo na saliva / Non-surgical periodontal treatment impact on biomarkers levels of bone metabolism in saliva

O objetivo foi avaliar o efeito do tratamento periodontal não cirúrgico, após 1 ano, na expressão salivar dos marcadores do metabolismo ósseo: TNF-α, SOST, PTH, OPG, OPN, OC, Leptina, IL-6, IL-1ß e FGF-23; em pacientes com periodontite crônica generalizada. Participaram deste estudo 15 pacientes com periodontite crônica generalizada (idade média 56,0  DP 9,6 anos). Quinze pacientes com gengivite (idade média 39,7  DP 4,4 anos) foram utilizados como controles. Foram utilizados os seguintes parâmetros clínicos: profundidade de bolsa à sondagem (PBS); nível de inserção clínica (NIC); índice de placa visível (IPV); índice de sangramento gengival (ISG) e índice de sangramento à sondagem (ISS). Foi realizada a coleta de saliva não estimulada (1ml) e congelada à -70°C para posterior análise. Os pacientes de ambos os grupos receberam tratamento periodontal não cirúrgico. Todos os dados foram coletados em 3 visitas no grupo com periodontite (baseline, 6 meses e 1 ano); e em 2 visitas no grupo com gengivite (baseline e 1 ano). Os biomarcadores foram mensurados por meio de um imunoensaio multiplex. No grupo com periodontite, houve redução significativa dos parâmetros % PBS ≥ 6 (p<0,001) e % NIC ≥ 5 (p<0,001), nas visitas 6 meses e 1 ano. Para os dados clínicos do grupo com gengivite, houve diminuição significativa após 1 ano para: % placa (p=0,001), % sangramento marginal (p=0,001), % sangramento sondagem (p=0,001), PBS (média pac.) (p=0,020) e NIC (média pac.) (p=0,001). Após o tratamento no grupo com periodontite, observou-se redução significativa da IL-1ß, IL-6, Leptina e TNF-α, entre a visita baseline e 6 meses (p=0,006; p=0,050; p=0,047; p= 0,014; respectivamente). Entre o baseline e 1 ano, houve diferença significante para a IL-1ß (p=0,010) e OPG (p=0,050). Já a IL-6 e OPG, mostraram uma tendência a redução após 1 ano (p=0,074; p=0,063; respectivamente). No grupo com gengivite, não foram observadas diferenças significativas entre as visitas baseline e 1 ano para todos os biomarcadores. No grupo com periodontite, na visita 1 ano, observamos correlação negativa significativa da OPG com % sangramento sondagem ( τ-b = -0,524 / p=0,006); no grupo com gengivite, na visita baseline, observamos correlação positiva significativa da IL-6 com % placa (τ-b= 0,548 / p= 0,005). Já na visita 1 ano, a Leptina passou a se correlacionar de forma mais forte com % placa (τ-b=0,624 / p=0,010) e com % sangramento marginal (τ-b=0,751 / p= 0,001). Concluindo, a terapia periodontal não cirúrgica levou a uma melhora significativa dos parâmetros clínicos periodontais associada à uma redução significante nos níveis de TNF-α, Leptina e IL-1ß; e uma tendência à redução dos biomarcadores OPG e IL-6. Após 1 ano, verificamos que os níveis dos biomarcadores do grupo com periodontite se aproximaram aos valores do grupo com gengivite, sugerindo que o tratamento periodontal foi capaz de equalizar a resposta imunológica.

The aim of this study was to evaluate the effect of non-surgical periodontal therapy, after 1 year, on the salivar expression of bone metabolism markers: TNF-α, SOST, PTH, OPG, OPN, OC, Leptin, IL-6, IL-1ß and FGF-23; in patients with generalized chronic periodontitis. Fifteen patients with generalized chronic periodontitis (mean age 56.0 ± SD 9.6 years) were included in this study. Fifteen patients with gingivitis (mean age 39.7 ± SD 4.4 years) were used as controls. Clinical evaluation parameters including probing pocket depth (PD), clinical attachment level (CAL), visible plaque index (VPI), gingival index bleeding (GI) and bleeding on probing (BOP) were used. Non-stimulated whole saliva was collected (1ml) and frozen at -70°C for further analysis. Patients from both groups received non-surgical periodontal treatment. All data were collected in 3 visits in the group with periodontitis (baseline, 6 months and 1 year); and in 2 visits in the group with gingivitis (baseline and 1 year). The biomarkers expression were evaluated through multiplex technology. In the group with periodontitis, there was a significant reduction of the parameters % PD ≥ 6 (p <0,001) and % CAL ≥ 5 (p <0,001), at 6 months and 1 year visits. For the clinical data of the group with gingivitis, there was a significant decrease after 1 year for: plaque (p=0,001), sulcus bleeding (p=0,001), bleeding on probing (p=0,001), PD (p=0,020) and CAL (p=0,001). After treatment in the group with periodontitis, a significant reduction of IL-1ß, IL-6, Leptin and TNF-α was observed between baseline and 6 months visit (p=0,006; p=0,050; p=0,047; p=0,014; respectively). Between baseline and 1 year, there was significant difference for IL-1ß (p=0,010) and OPG (p=0,050). On the other hand, IL-6 and OPG showed a tendency to decrease after 1 year (p=0,074; p=0,063; respectively). In the group with gingivitis, no significant differences were observed between the baseline visits and 1 year for all biomarkers. In the group with periodontitis, at the 1-year visit, we observed a significant negative correlation of OPG with bleeding on probing (τ-b=-0,524 / p=0,006); in the group with gingivitis, at the baseline visit, we observed a significant positive correlation of IL-6 with plaque (τ-b=0,548 / p=0,005). At the 1-year visit, Leptin correlated more strongly with plaque (τ-b=0,624 / p=0,010) and with sulcus bleeding (τ-b=0,751 / p=0,001). In conclusion, non-surgical periodontal therapy led to a significant improvement in periodontal clinical parameters associated with a significant reduction in levels of TNF-α, Leptin and IL-1ß; the OPG and IL-6 showed a tendency to reduce. After 1 year, we observed that the biomarkers levels in the group with periodontitis approximate the values of the group with gingivitis, suggesting that the periodontal treatment was able to equalize the immune response.

Mecanismos involucrados en la fragilidad ósea en diabetes mellitus / Mechanisms involved in the bone fragility in diabetes mellitus

La diabetes es una enfermedad crónica asociada con importantes comorbilidades. El sistema esquelético parece ser un objetivo adicional de daño mediado por diabetes. Se acepta que la diabetes tipo 1 y tipo 2 se asocian con un mayor riesgo de fractura ósea. Varios estudios han demostrado que los cambios metabólicos causados por la diabetes pueden influir en el metabolismo óseo disminuyendo la calidad y la resistencia del hueso. Sin embargo, los mecanismos subyacentes no se conocen por completo pero son multifactoriales y, probablemente, incluyen los efectos de la obesidad, hiperglucemia, estrés oxidativo y acumulación de productos finales de glicosilación avanzada. Estos darían lugar a un desequilibrio de varios procesos y sistemas: formación de hueso, resorción ósea, formación y entrecruzamiento de colágeno. Otros factores adicionales como la hipoglucemia inducida por el tratamiento, ciertos medicamentos antidiabéticos con un efecto directo sobre el metabolismo óseo y mineral, así como una mayor propensión a las caídas, contribuirían al aumento del riesgo de fracturas en pacientes con diabetes mellitus. Esta revisión tiene como objetivo describir los mecanismos fisiopatológicas subyacentes a la fragilidad ósea en pacientes diabéticos. (AU)

Diabetes is a chronic disease associated with important comorbidities. The skeletal system seems to be an additional target of diabetes mediated damage. It is accepted that type 1 and type 2 diabetes are associated with an increased risk of bone fracture. Several studies have shown that metabolic changes caused by diabetes can influence bone metabolism by decreasing bone quality and resistance. However, the underlying mechanisms are not completely known but they are multifactorial and probably include the effects of obesity, hyperglycemia, oxidative stress and accumulation of advanced glycosylation end products. These would lead to an imbalance of several processes and systems: bone formation, bone resorption, formation and collagen crosslinking. Other additional factors such as treatment-induced hypoglycemia, certain antidiabetic medications with a direct effect on bone and mineral metabolism, as well as an increased propensity for falls, would contribute to the increased risk of fractures in patients with diabetes mellitus. This review aims to describe the pathophysiological mechanisms underlying bone fragility in diabetic patients. (AU)

De la osteología a la osteomiología: tres décadas de aportes originales continuos al análisis biomecánico osteomuscular / From osteology to osteo-myology: three decades of continuous, original contributions to musculoskeletal biomechanical analysis

En consonancia con la orientación tradicional de nuestras investigaciones, la Osteología está incorporando progresivamente el análisis estructural-biomecánico óseo y las interacciones músculo-esqueléticas. En este artículo se sintetizan los aportes originales del CEMFoC a la Osteología moderna en el terreno biomecánico en forma didáctica, para que el lector aprecie sus posibles aplicaciones clínicas. Los hallazgos aportaron evidencias sucesivas en apoyo de dos proposiciones fundamentales: a) los huesos deben interpretarse como estructuras resistivas, biológicamente servocontroladas ("Los huesos tienden siempre a mantener un factor de seguridad que permite al cuerpo trabajar normalmente sin fracturarse" ­ Paradigma de Utah) y b) los huesos interactúan con su entorno mecánico, determinado principalmente por las contracciones musculares, en forma subordinada al entorno metabólico ("Los huesos son lo que los músculos quieren que sean, siempre que las hormonas lo permitan"). Los avances producidos se refieren, tanto cronológica como didácticamente, al conocimiento osteológico en general y al desarrollo de recursos novedosos para el diagnóstico no invasivo de fragilidad ósea, para distinguir entre osteopenias y osteoporosis, y para discriminar entre sus etiologías 'mecánica' y 'sistémica'. Finalmente, el nuevo conocimiento se integra en la proposición de un algoritmo diagnóstico para osteopenias y osteoporosis. El espíritu general de la presentación destaca que la evaluación osteomuscular dinámicamente integrada genera un nuevo espacio de análisis personalizado de los pacientes para la atención de cualquier osteopatía fragilizante con criterio biomecánico. (AU)

In consonance with the traditional spirit of our studies, skeletal research is being progressively focused on the structural-biomechanical analysis of bone and the muscle-bone interactions. In this article, the CEMFoC's members summarize their original findings in bone biomechanics and their potential clinical applications. These findings provided evidence supporting two fundamental hypotheses, namely, A. bones constitute resistive structures, which are biologically servo-controlled ('Bones tend to maintain a safety factor which allows the body to function normally avoiding fractures' ­ the 'Utah paradigm'), and B. the interactions of bones with their mechanical environment mainly are determined by the contraction of local muscles - 'bone-muscle units'), and are subordinated to the control of the metabolic environment ('Bones are what muscles wish them to be, provided that hormones allow for it'). The achievements in the field are presented in a chronological and didactical sequence concerning the general knowledge in Osteology and the development of novel resources for non-invasive diagnosis of bone fragility, aiming to distinguish between osteopenias and osteoporosis and the 'mechanical' and 'metabolic' etiology of these conditions. Finally, the integrated new knowledge is presented as supporting for a proposed diagnostic algorithm for osteopenias and osteoporosis. In general terms, the article highlights the dynamic evaluation of the musculoskeletal system as a whole, opening a new diagnostic field for a personalized evaluation of the patients affected by a boneweakening disease, based on functional and biomechanical criteria. (AU)

The enigma of aluminum deposition in bone tissue from a patient with chronic kidney disease: a case report / O enigma da deposição de alumínio no tecido ósseo de um paciente com doença renal crônica: relato de caso

ABSTRACT About four decades ago, the relationship between dialysis-dementia and aluminum (Al) began to be established. The restriction of drugs containing Al and improvements on water quality used for dialysis resulted in the clinical disappearance of Al intoxication. However, high prevalence of Al deposition in bone tissue from Brazilian dialysis patients is still being detected. Through the case report of a patient on hemodialysis (HD) for one year, presenting significant Al deposition in bone tissue, we speculated if this problem is not being underestimated. We used extensive investigation to identify potential sources of Al exposure with a careful review of medication history and water quality controls. Al concentration was measured by different methods, including mass spectrometry, in poly-electrolyte concentrate solutions and solution for peritoneal dialysis, in an attempt to elucidate the possible sources of contamination. The objective of this case report is to alert the medical community about a potential high prevalence of Al deposition in bone tissue and to discuss the possible sources of contamination in patients with chronic kidney disease (CKD).

RESUMO Cerca de quatro décadas atrás, a relação entre demência relacionada à diálise e alumínio (Al) começou a ser estabelecida. A restrição de medicamentos contendo Al e melhorias na qualidade da água utilizada na diálise resultaram no desaparecimento clínico da intoxicação por Al. Contudo, no Brasil continua a ser identificada uma elevada prevalência de deposição de Al no tecido ósseo de pacientes em diálise. O presente relato de caso de um paciente em hemodiálise (HD) há um ano com deposição significativa de Al no tecido ósseo nos leva a especular se esse problema não tem sido subestimado. Realizamos uma ampla investigação para identificar possíveis fontes de exposição ao Al, com uma revisão cuidadosa do histórico de medicação e dos controles de qualidade da água. A concentração de Al foi medida por diferentes métodos, incluindo espectrometria de massa, nos concentrados polieletrolíticos para hemodiálise e soluções de diálise peritoneal, na tentativa de elucidar as possíveis fontes de contaminação. O objetivo do presente relato de caso é alertar a comunidade médica sobre uma possível elevada prevalência de deposição de Al no tecido ósseo e discutir as possíveis fontes de contaminação nos pacientes com doença renal crônica (DRC).

Effects of a 20-week concurrent training program on bone metabolism in elderly women / Efecto de 20 semanas de entrenamiento concurrente sobre el metabolismo óseo de adultas mayores

The present study evaluated the effect of a 20-week concurrent training program on bone metabolism in elderly women. The sample consisted of 51 elderly women living in the municipality of Muriaé (MG), distributed into two groups: a concurrent training group (CTG = 25), with an average age of 69.44 ± 6.82 years, and a control group (CG = 26), with mean age of 68.30 ± 6.34 years. Biophysical parameters were determined based on weight, height and body mass index. Bone metabolism was assessed by collecting second-morning urine samples before and after intervention to analyze levels of the biochemical marker deoxypyridinoline (DPD), which quantifies bone resorption. Results: The results showed a post-intervention decline in DPD content in the GTC when compared to controls (p = 0.007) and an improvement in the variables weight, BMI and DPD between the GTC and GC (p = 0.000). Conclusion: Concurrent training was efficient in improving bone metabolism in the elderly population studied.

El presente estudio evaluó los efectos de 20 semanas de entrenamiento concurrente sobre el metabolismo óseo de adultas mayores. La muestra fue compuesta por 51 mujeres adultas mayores, residentes en el municipio de Muriaé (MG), voluntarias, distribuidas en dos grupos, un grupo participó en entrenamiento concurrente (GTC=25), con una edad media de 69,44±6,82 años y un grupo control (GC=26) con una media de 68,30±6,34 años. Los parámetros biofísicos se determinaron por medio del peso corporal, la estatura e índice de masa corporal. Para la evaluación del metabolismo óseo, se realizó la recolección de la orina matinal en el pre y post-test, utilizando como reactivo el marcador bioquímico de deoxipiridinolina (DPD) que cuantifica la reabsorción ósea. Los resultados mostraron una reducción en la concentración de DPD en el GTC cuando se compararon los grupos (p = 0,007) y la mejora de las variables, peso corporal, IMC y DPD entre el GTC y el GC en el post-test (p = 0,000). Se percibe que el entrenamiento concurrente, para las mujeres adultas mayores fue eficiente en la mejoría de las condiciones de salud del metabolismo óseo.

Histomorphometric reference data of transiliac bone biopsy in children from 8 to 17 years old / Datos histomorfométricos de referencia de la biopsia ósea en niños de 8 a 17 años

Abstract: Background: Histomorphometric analysis of bone samples is a key tool for studying bone metabolism; however, only a few pediatric reference data exist. The aim of the present study is to report more reference data and to investigate if histomorphometric differences exist between age and gender. Methods: We obtained 19 transiliac bone samples previously marked with tetracycline, from children between 8 and 17 years (13 were male), with normal blood test results and urine biochemical bone markers. We evaluated bone histomorphometric parameters using a digitalizing table with osteomeasure to obtain normative data of means and standard deviations, as well as median and range. Due to the small sample, a Monte Carlo simulation was applied. Structural, static, dynamic, and resorptic histomorphometric parameters were evaluated by age and gender following the American Society for Bone and Mineral Research recommendations. Results: Bone volume (in the older children) and mineral apposition rate (in the younger children), the eroded surface (in boys), and the new bone wall thickness (in girls) were significantly increased. On the trabecular area of mineralization front, the modeling and the remodeling bone formation were similar (16 and 18%). The rest of the histomorphometric bone parameters by age and gender showed no significant difference. Conclusion: In healthy children, these bone histomorphometric findings, with these techniques and for this ages could be used as reference values.

Resumen: Introducción: El análisis histomorfométrico del tejido óseo para el estudio de las enfermedades metabólicas óseas, cuando se correlacionan los hallazgos clínicos, sigue siendo la herramienta con mayor sensibilidad y especificidad para la mayoría de los diagnósticos. En los niños existen pocos reportes histomorfométricos del tejido óseo metabólico normal, por lo que nuestro propósito es reportar más datos de referencia e investigar si hay diferencias histomorfométricas entre edades y sexos. Métodos: Estudio realizado en 19 niños de 8 a 17 años (13 masculinos) sin anomalías clínicas ni bioquímicas evidentes. Se tomaron muestras de tejido óseo transilíaco marcadas con tetraciclina. Se obtuvieron medias, desviaciones y rangos histomorfométricos totales, y correlación por edad y sexo, siguiendo las recomendaciones para la histomorfometría de la American Society for Bone and Mineral Research. Se realizó una simulación Montecarlo. Resultados: El volumen óseo (en niños mayores), la velocidad de agregación del mineral (en niños menores), la erosión trabecular periférica (en niños) y el grosor de la pared ósea nueva (en niñas) exhibieron aumentos significativos. En el área trabecular del frente de mineralización, el modelado y el remodelado de la formación ósea fueron similares (16 y 18%). El resto de los parámetros histomorfométricos óseos no mostraron diferencias significativas. Conclusiones: Estos hallazgos histomorfométricos del tejido óseo de niños normales con estas técnicas y para estas edades pueden ser utilizados como valores de referencia.

Statins and bonehealth: a mini review / Estatinas y salud ósea: una minirevisión

Statins are a widely prescribed class of medications that inhibit similar pathways as the anti-resorptive bisphosphonate drugs. Statins target the mevalonate pathway by blocking HMG-CoA reductase. Several recent meta-analyses concluded statins are osteoprotective in the general population. Here we present current literature exploring the mechanisms underlying the putative osteoprotective effects of statins. We also review recent clinical studies, ranging from observational cohort studies to randomized clinical trials, testing the effect of statins on bone health in various populations. (AU)

Las estatinas son un grupo de drogas prescriptas en forma habitual, con la capacidad de bloquear vías de señalización similares a las inhibidas por los amino-bisfosfonatos. Las estatinas inhiben la vía del mevalonato, a través del bloqueo de diferentes enzimas. Varios metaanálisis recientes llevaron a la conclusión de que las estatinas tienen capacidad osteoprotectora en la población general. En esta revisión presentamos la literatura actual describiendo los mecanismos que subyacen en el potencial efecto osteoprotector de las estatinas, como así también estudios observacionales y clínicos aleatorizados sobre el efecto de estatinas en la salud ósea en diversas poblaciones. (AU)

Criopreserved ovarian tissue transplantation and bone restoration metabolism in castrated rats / Transplante de tecido ovariano criopreservado e restauração do metabolismo ósseo em ratas castradas

ABSTRACT Objectives: to evaluate estradiol levels and autotransplantation heated ovarian tissue effects, after vitrification, on rats bone metabolism previously oophorectomized bilaterally. Methods: experimental study with 27 rats aged 11 to 12 weeks and weighing 200g to 300g, submitted to bilateral oophorectomy and ovarian tissue cryopreservation for subsequent reimplantation. Animals were divided into two groups, A and B, with 8 and 19 rats, respectively. Autotransplantation occurred in two periods according to castration time: after one week, in group A, and after one month in group B. Serum estradiol measurements and ovary and tibia histological analysis were performed before and after oophorectomy period (early or late) and one month after reimplantation. Results: in groups A and B, tibia median cortical thickness was 0.463±0.14mm (mean±SD) at the baseline, 0.360±0.14mm after oophorectomy and 0.445±0.17mm one month after reimplantation p<0.005). Trabecular means were 0.050±0.08mm (mean±SD) at baseline, 0.022±0.08mm after oophorectomy and 0.049±0.032mm one month after replantation (p<0.005). There was no statistical difference in estradiol variation between the two study groups (p=0.819). Conclusion: cryopreserved ovarian tissue transplantation restored bone parameters, and these results suggest that ovarian reimplantation in women may have the same beneficial effects on bone metabolism.

RESUMO Objetivos: avaliar os níveis de estradiol e os efeitos do autotransplante de tecido ovariano aquecido, após vitrificação, no metabolismo ósseo de ratas previamente ooforectomizadas bilateralmente. Métodos: trabalho experimental com 27 ratas com idades entre 11 e 12 semanas e pesando 200g a 300g, submetidas à ooforectomia bilateral e criopreservação de tecido ovariano para posterior reimplante. Os animais foram divididos em dois grupos, A e B, com oito e 19 ratas, respectivamente. O autotransplante ocorreu em dois períodos de acordo com o tempo de castração: após uma semana, no grupo A, e após um mês no grupo B. Mensurações de estradiol sérico e análise histológica de ovário e tíbia foram feitos antes e após o período de ooforectomia (precoce ou tardio) e um mês após o reimplante. Resultados: nos grupos A e B, as espessuras corticais médias da tíbia foram 0,463±0,14mm (média±DP) na linha de base, 0,360±0,14mm após ooforectomia e 0,445±0,17mm em um mês após o reimplante (p<0,005). As médias trabeculares foram 0,050±0,08mm (média±DP) na linha de base, 0,022±0,08mm após ooforectomia e 0,049±0,032mm em um mês após o reimplante (p<0,005). Não houve diferença estatística entre a variação do estradiol entre os dois grupos de estudo (p=0,819). Conclusão: o transplante de tecido ovariano criopreservado restabeleceu os parâmetros ósseos, e estes resultados sugerem que a reimplantação ovariana em mulheres pode apresentar os mesmos efeitos benéficos sobre o metabolismo ósseo.

Bone turnover after bariatric surgery

ABSTRACT Objective The aim of the present study was to evaluate parameters of bone and mineral metabolism after bariatric surgery. Subjects and methods This sectional study included data from medical records from 61 bariatric surgery (BS) patients (minimum period of 6 months after the procedure) and from 30 class II and III obese patients as a control group (Cont), consisting of daily dietary intake of macronutrients, calcium and sodium, serum 25(OH)D and parathyroid hormone (PTH) and other biochemical serum and urinary parameters. Bone alkaline phosphatase (BAP), leptin, fibroblast growth factor-23 (FGF-23) and deoxypyridinoline (DPYD) were determined from available banked serum and urinary samples. Results Mean body mass index (BMI), median energy, carbohydrate, protein and sodium chloride consumption were significantly lower in the BS versus Cont, but calcium and lipids were not. No significant differences were found in ionized calcium, 25(OH)D, PTH and fibroblast growth factor 23 (FGF-23) between groups. Mean serum BAP was significantly higher for BS versus Cont and had a positive correlation with time after the surgical procedure. Mean serum leptin was significantly lower and median urinary DPYD higher in BS versus Cont. Conclusion The present study showed an increase in bone markers of both bone formation and resorption among bariatric patients up to more than 7 years after the surgical procedure, suggesting that an increased bone turnover persists even at a very long-term follow-up in such patients.

Prevalencia de causas secundarias de baja masa ósea en una población de mujeres premenopáusicas / Prevalence of secondary causes in a population of premenopausal women with low bone mass

La osteoporosis es un trastorno común en las mujeres posmenopáusicas; sin embargo, también puede afectar a hombres y mujeres jóvenes premenopáusicas. El objetivo del presente trabajo fue evaluar la prevalencia de causas secundarias de baja masa ósea en un grupo de mujeres premenopáusicas que consultaron en una Institución especializada en Osteología. Material y métodos: se realizó un estudio retrospectivo, de corte transversal, descriptivo y observacional. Se analizaron las historias clínicas de 88 pacientes que consultaron por baja masa ósea durante un período de 19 meses, con la finalidad de encontrar posibles causas secundarias. A su vez, se definió como pacientes con diagnóstico de baja masa ósea idiopática aquellas en las cuales no se encontró ninguna causa secundaria de pérdida ósea. Resultados: de las 88 mujeres evaluadas, el 48,9% presentaba al menos una causa secundaria para baja masa ósea (amenorrea secundaria, hipercalciuria, tratamiento con glucorticoides, hipovitaminosis D y enfermedad celíaca) y el 51,1% fueron consideradas idiopáticas. Conclusiones: es esencial evaluar exhaustivamente a las mujeres premenopáusicas con baja masa ósea a fin de descartar posibles causas secundarias y tomar las medidas preventivas necesarias para mejorar esa condición. (AU)

Objective: osteoporosis is a common disorder in postmenopausal women, however it can also affect men and premenopausal young women. The purpose of this study was to evaluate the prevalence of secondary causes of low bone mass in premenopausal women that consulted physicians in an institution specialized in osteology for a period of 19 months. Material and methods: this is a retrospective, transversal, descriptive and observational study. The clinical history of 88 patients who consulted a physician due to low bone mass for a period of 19 months in an institution specialized in osteology. Were analyzed the patient's clinical history in order to find secondary causes. We define as suffering Low Bone Mass those patients who did not have secondary causes. Results: of the 88 women tested, 48,9% had one or more secondary causes or risks factors for low bone mass (secondary amenorrea, hypercalciuria, treatment with glucocorticoids, hypovitamiosis D and celiac disease) and 51,1% patients were considered idiopathic. Conclusions: we conclude that it is essential to exhaustively search for secondary causes of low bone mass in premenopausal women, due to the high prevalence of secondary osteoporosis in this population. (AU)

Matrices de tercera generación en la ingeniería de tejidos ósea / Third-generation matrices in bone tissue engineering

Existen numerosas patologías que generan situaciones invalidantes debido a problemas asociados a nivel de defectos óseos. Esto genera, en muchas oportunidades, cuestiones sanitarias de alto impacto. La ingeniería de tejidos óseos pretende generar propuestas novedosas para reparar pérdidas o fracturas óseas, promoviendo regenerar el tejido mediante el implante de matrices biodegradables que puedan actuar como estructuras para la adhesión celular, favoreciendo el crecimiento y la diferenciación hasta formar hueso de novo. El incremento notable de los conocimientos en las áreas biotecnológicas, de síntesis química, así como de biomedicina, permiten el desarrollo de numerosos tipos de matrices de tercera generación, biodegradables y no tóxicas, con características que proponen sean consideradas en la regeneración tisular ósea. Este trabajo intenta resumir los tipos de matrices que mayor impacto han tenido hasta el momento en la medicina regenerativa ósea, mostrando los casos más relevantes de resultados experimentales y clínicos, y propone algunas perspectivas que se deberían considerar para poder aplicarlas a la práctica clínica. Esta es un área que invita a los investigadores a posicionarse en un pensamiento complejo desde el punto de vista científico-filosófico. (AU)

There are several pathologies that generate disability due to complications associated with bone defects. This often generates high impact health troubles. Bone tissue engineering aims to generate novel means to repair bone loss or bone fractures, promoting tissue regeneration through the implantation biodegradables scaffolds, which can act as structures for cell adhesion, that promts cell growth and differentiation for the novo bone formation. The remarkable for the novo bone formation in biotechnology, chemical synthesis, and biomedical knowledge allows the development of numerous types of third generation scaffolds, applied to promote bone tissue regeneration. This brief report aims to review the scaffolds that have had more impact in bone regenerative medicine so far, describing the most relevant experimental and clinical results. This is an area that invites researchers to situate themselves in a complex thought of scientific-philosophical point of view. (AU)

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.