Masa ósea y tratamiento esteroideo en pacientes con hiperplasia suprarrenal congénita / Bone mass and steroid treatment in patients with congenital adrenal hyperplasia

Introducción: La terapia de reemplazo con glucocorticoides sigue siendo el paradigma de tratamiento en las formas clásicas de la hiperplasia suprarrenal congénita. Sus efectos sobre la mineralización ósea no están totalmente claros. Objetivo: Describir las variables relacionadas con la masa ósea en pacientes con HSC que reciben tratamiento esteroideo sustitutivo. Método: Se realizó un estudio descriptivo transversal que exploró variables clínicas, bioquímicas, hormonales y de mineralización óseaen 25 pacientes con hiperplasia suprarrenal congénita por déficit de 21OHasa y tratamiento esteroideo. Resultados: 21 (84,0 por ciento) femeninas, el mayor grupo correspondió a los adolescentes entre 10 y 19 años (52 por ciento). Predominaron las formas clásicas con 22 pacientes (88,0 por ciento), de ellas 13 (52 por ciento) fueron perdedoras de sal, 9 virilizantes simples (36,0 por ciento) y solo 3 (12,0 por ciento) formas no clásicas. El esteroide más utilizado fue la hidrocortisona en 16 pacientes (64 por ciento), a una dosis media de 22,10±12,00 mg diarios, correspondiendo con 17,09±5,71 mg/m2sc/día y como promedio llevaban 14,02±6,57 años de terapéutica sustitutiva. No se detectaron alteraciones del metabolismo fosfocálcico. La densidad y el contenido mineral óseo en columna y en fémur mostraron valores superiores en las formas no clásicas de la enfermedad, seguidos de la virilizante simple y finalmente los pacientes perdedores de sal, en ninguno de los casos con significación estadística. Conclusiones: Los pacientes con hiperplasia suprarrenal congénita del presente estudio mostraron en su mayoría una masa ósea conservada(AU)

Introduction: Glucocorticoid replacement therapy is still the treatment´s paradigm in the classic forms of congenital adrenal hyperplasia. Its effects on bone mineralization are not entirely clear. Objective: Describe bone mass-related variables in congenital adrenal hyperplasia patients receiving substitute steroid treatment. Method: A cross-sectional descriptive study was conducted exploring clinical, biochemical, hormonal and bone mineralization variables in 25 patients with congenital adrenal hyperplasia caused by 21OHase deficiency and steroid treatments. Results: 21 women (84.0 percent); the largest group was of adolescents between the age of 10 and 19 years (52 percent).Classical forms predominated with 22 patients (88.0 percent), including 13 of them (52 percent) that were salt losers, 9 simple virilizers (36.0 percent) and only 3 (12.0 percent) of non-classical forms. The most commonly used steroid was hydrocortisone in 16 patients (64 percent), at an average dose of 22.10±12.00 mg daily, corresponding to 17.09±5.71 mg/m2sc/day and on average carried 14.02±6.57 years of substitute therapy. No alterations in the phosphocalcic metabolism were detected. Density and bone mineral content in the spinal column and femur showed higher values in non-classical forms of the disease, followed by simple virilizing and finally the salt loser patients, in none of the cases with statistical significance. Conclusions: Patients with congenital adrenal hyperplasia in this study showed mostly preserved bone mass(AU)

Analysis of lifestyle and bone mineralization in a population of Spanish young adults / Análisis de los estilos de vida y la mineralización ósea en una población de adultos jóvenes españoles

Abstract Objective: To analyze the environmental factors (nutritional status, levels of physical activity and nutritional habits) and their possible association with bone mass in a population of young adults. Methods: The study population consisted of 200 subjects (117 women and 83 men) aged between 18 and 25 years (mean age 20.4 years ±2.2 years). Body composition parameters were measured by an electronic balance (TANITA BC-418MA), nutritional habits were estimated by 72-h dietary recall, level of physical activity was assessed by the International Physical Activity Questionnaire (IPAQ) and bone mass was measured by ultrasonography at the calcaneus. Results: There were significant differences in bone mass values ​​according to gender (p= 0.013). Despite the fact that 70% of the subjects had a body mass index (BMI) within the normal range, 20% had overweight or obesity. 49% of the individuals had a moderate level of physical activity, although women had lower levels of physical activity than men (17.9% vs 8.4%). Most diets among young adults were hyperprotic, hyperlipidic and low-carbohydrates, with low-calcium and fiber intakes and high-phosphorus. Analysis of bone mass according to BMI showed higher values ​​as the weight category rises, with significant differences in women. Higher values ​​of bone mass were shown as the level of physical activity was higher, showing significant differences in males. Conclusion: Our results show that BMI and level of physical activity are significantly associated with bone health in a population of young adults, suggesting the relevance of promoting healthy lifestyles as a strategy for the early prevention of osteoporosis.

Resumen Objetivo: Analizar los factores ambientales (estado nutricional, nivel de actividad física y hábitos nutricionales) y su posible relación con los niveles de masa ósea en una población de adultos jóvenes. Métodos: La población de estudio estuvo constituida por 200 sujetos (117 mujeres y 83 hombres) de edades comprendidas entre 18 y 25 años (edad media 20.4 años ± 2.2 años). La composición corporal se evaluó con balanza electrónica (TANITA BC-418MA), la valoración de los hábitos nutricionales mediante Recordatorio de 72 h, el nivel de actividad física a través del Cuestionario Internacional de Actividad Física (IPAQ) y la masa ósea mediante ultrasonografía en el calcáneo. Resultados: Existen diferencias estadísticamente significativas en los valores de masa ósea en función del sexo (p= 0.013). A pesar de que el 70% de los sujetos presentaron un índice de masa corporal (IMC) dentro de los límites de la normalidad, un 20% padece sobrepeso y obesidad. El 49% de los individuos tenian un nivel moderado de actividad física, aunque las mujeres presentaron niveles más bajos de actividad física que lo varones (17.9% vs 8.4%). Las dietas mayoritarias entre los adultos jóvenes son hiperprotéicas, hiperlipídicas y bajas en hidratos de carbono, observándose una ingesta baja de calcio y fibra y alta en fósforo. El análisis de la masa ósea en función de IMC mostró valores mayores conforme asciende la categoría ponderal, existiendo diferencias significativas en mujeres. Igualmente, se muestran valores más altos de masa ósea conforme mayor es el nivel de actividad física, evidenciando diferencias significativas en los varones. Conclusión: Nuestros resultados muestran que el índice de masa corporal y el nivel de actividad física se asocian significativamente con la salud ósea en una población de adultos jóvenes, evidenciando la importancia del fomento de estilos de vida saludables como estrategia para la prevención temprana de la osteoporosis.

The multiple effects of thyroid disorders on bone and mineral metabolism / Os múltiplos efeitos das disfunções tireoidianas sobre o metabolismo osteomineral

Differently from most hormones, which commonly are specialized molecules able to influence other cells, tissues and systems, thyroid hormones (TH) are pleiotropic peptides, whose primordial function is difficult to identify. The complex action of TH on human economy can be easily witnessed by examining the diverse consequences of TH excess and deficiency during development and after maturity. In particular, different manifestations in bone modeling and remodeling reflect the circumstantial consequences of thyroid disturbances, which are age dependent. While hyperthyroidism during childhood enhances bone mineralization and accelerates epiphyseal maturation, in adults it induces bone loss by predominant activation of osteoclast activity. Furthermore, the syndrome of TH resistance is a multifaceted condition in which different sites exhibit signs of hormone excess or deficiency depending on the configuration of the TH receptor isoform. The investigation of the impact of TH resistance on the skeleton still remains to be elucidated. We present here a thorough review of the action of TH on bone and of the impact of thyroid disorders, including hyper- and hypothyroidism and the syndrome of TH resistance, on the skeleton.

Diferentemente da maioria dos hormônios, que usualmente são moléculas especializadas capazes de influenciar outras células, tecidos e sistemas, os hormônios da tireoide (HT) são peptídeos pleiotrópicos, cuja função primordial é difícil de identificar. A ação complexa dos HT na fisiologia humana pode ser facilmente reconhecida ao observar as diversas consequências do excesso e da deficiência de HT durante e após o pleno desenvolvimento. Em particular as diferentes manifestações na modelação e remodelação óssea refletem que as consequências esqueléticas das disfunções tireoidianas dependem das circunstâncias e variam com a idade. Enquanto o hipertireoidismo durante a infância aumenta a mineralização óssea e acelera a maturação epifisária, em adultos induz a perda óssea pela ativação predominante da ação osteoclástica. Além disso, a síndrome de resistência ao HT é uma condição multifacetada na qual diferentes tecidos apresentam sinais de excesso ou deficiência hormonal, dependendo da predominância da expressão das diversas isoformas do receptor de HT. O impacto da resistência ao HT sobre o esqueleto ainda é motivo de investigação. Apresentamos aqui uma revisão abrangente sobre as ações ósseas dos HT e o impacto no esqueleto dos distúrbios da tireoide, incluindo hipo e hipertireoidismo e síndrome de resistência ao HT.

Expression of non-neuronal cholinergic system in maxilla of rat in vivo

BACKGROUND: Acetylcholine (ACh) is known to be a key neurotransmitter in the central and peripheral nervous systems, which is also produced in a variety of non-neuronal tissues and cell. The existence of ACh in maxilla in vivo and potential regulation role for osteogenesis need further study. RESULTS: Components of the cholinergic system (ACh, esterase, choline acetyltransferase, high-affinity choline uptake, n- and mAChRs) were determined in maxilla of rat in vivo, by means of Real-Time PCR and immunohistochemistry. Results showed RNA for CarAT, carnitine/acylcarnitine translocase member 20 (Slc25a20), VAChT, OCTN2, OCT1, OCT3, organic cation transporter member 4 (Slc22a4), AChE, BChE, nAChR subunits α1, α2, α3, α5, α7, α10, ß1, ß2, ß4, γ and mAChR subunits M1, M2, M3, M4, M5 were detected in rat's maxilla. RNA of VAChT, AChE, nAChR subunits α2, ß1, ß4 and mAChR subunits M4 had abundant expression (2(-ΔCt) > 0.03). Immunohistochemical staining was conducted for ACh, VAChT, nAChRα7 and AChE. ACh was expressed in mesenchymal cells, chondroblast, bone and cartilage matrix and bone marrow cells, The VAChT expression was very extensively while ACh receptor α7 was strongly expressed in newly formed bone matrix of endochondral and bone marrow ossification, AchE was found only in mesenchymal stem cells, cartilage and bone marrow cells. CONCLUSIONS: ACh might exert its effect on the endochondral and bone marrow ossification, and bone matrix mineralization in maxilla.

Tissue transglutaminase (TG2) activity regulates osteoblast differentiation and mineralization in the SAOS-2 cell line

Tissue transglutaminase (type II, TG2) has long been postulated to directly promote skeletal matrix calcification and play an important role in ossification. However, limited information is available on the expression, function and modulating mechanism of TG2 during osteoblast differentiation and mineralization. To address these issues, we cultured the well-established human osteosarcoma cell line SAOS-2 with osteo-inductive conditioned medium and set up three time points (culture days 4, 7, and 14) to represent different stages of SAOS-2 differentiation. Osteoblast markers, mineralization, as well as TG2 expression and activity, were then assayed in each stage. Furthermore, we inhibited TG activity with cystamine and then checked SAOS-2 differentiation and mineralization in each stage. The results showed that during the progression of osteoblast differentiation SAOS-2 cells presented significantly high levels of osteocalcin (OC) mRNA, bone morphogenetic protein-2 (BMP-2) and collagen I, significantly high alkaline phosphatase (ALP) activity, and the increased formation of calcified matrix. With the same tendency, TG2 expression and activity were up-regulated. Furthermore, inhibition of TG activity resulted in a significant decrease of OC, collagen I, and BMP-2 mRNA and of ALP activity and mineralization. This study demonstrated that TG2 is involved in osteoblast differentiation and may play a role in the initiation and regulation of the mineralization processes. Moreover, the modulating effects of TG2 on osteoblasts may be related to BMP-2.

In vitro culture and characterization of alveolar bone osteoblasts isolated from type 2 diabetics

In order to understand the mechanisms of poor osseointegration following dental implants in type 2 diabetics, it is important to study the biological properties of alveolar bone osteoblasts isolated from these patients. We collected alveolar bone chips under aseptic conditions and cultured them in vitro using the tissue explants adherent method. The biological properties of these cells were characterized using the following methods: alkaline phosphatase (ALP) chemical staining for cell viability, Alizarin red staining for osteogenic characteristics, MTT test for cell proliferation, enzyme dynamics for ALP contents, radio-immunoassay for bone gla protein (BGP) concentration, and ELISA for the concentration of type I collagen (COL-I) in the supernatant. Furthermore, we detected the adhesion ability of two types of cells from titanium slices using non-specific immunofluorescence staining and cell count. The two cell forms showed no significant difference in morphology under the same culture conditions. However, the alveolar bone osteoblasts received from type 2 diabetic patients had slower growth, lower cell activity and calcium nodule formation than the normal ones. The concentration of ALP, BGP and COL-I was lower in the supernatant of alveolar bone osteoblasts received from type 2 diabetic patients than in that received from normal subjects (P < 0.05). The alveolar bone osteoblasts obtained from type 2 diabetic patients can be successfully cultured in vitro with the same morphology and biological characteristics as those from normal patients, but with slower growth and lower concentration of specific secretion and lower combining ability with titanium than normal ones.

Elongated styloid process: Is it a pathologic condition.

Objectives: The aims of this study were to evaluate the length, morphology, and calcification patterns of the elongated stylohyoid process (ESP) on panoramic radiographs and to investigate the symptoms related to it. We then addressed the question: Is ESP a pathologic condition or a physiologic phenomenon? Materials and Methods: In this study, 207 stylohyoid complexes were evaluated based on length, radiographic appearance, and calcification pattern on panoramic radiographs. Similar to previous studies, we considered 30 mm as a threshold for elongation of the process. Complexes were classified into two groups based on length: ESP (greater than or equal to 30 mm) and normal (less than 30 mm). Clinical symptoms were evaluated by using a questionnaire and clinical examination. Data were analyzed by the Kolmogorov-Smilonov test, Mann-Whitney U test, and Spearman correlation. Results: The average length of the stylohyoid complex was 31.7 mm. The median was 30.0 mm and corresponded to the threshold for the ESP. The Spearman correlation between the length of the complex and age was 0.323 (P=0.0001). "Continuous" and "calcified outline" were the most frequent morphology and calcification pattern, respectively, for both groups. Clinical symptoms related to ESP were not detected. Conclusion: Classification of the stylohyoid complexes based on apparent length on panoramic radiographs in elongated and normal types appears to be incorrect. Considering that the radiographic appearance of the ESP and normal groups was similar and pathologic symptoms were not detected and that there was a relationship between age and length of the complex, elongation of this complex can be considered as a physiologic phenomenon.

Mineralización ósea en niños y adolescentes con hipotiroidismo congénito / Bone mineralization in children and adolescents presenting with a congenital hypothyroidisM

Introducción: en el hipotiroidismo congénito la mineralización ósea puede afectarse por la enfermedad o por los efectos del tratamiento con hormonas tiroideas.Objetivo: determinar en pacientes con hipotiroidismo congénito la mineralización ósea. Métodos: se realizó estudio descriptivo transversal pareado, en niños cubanos con hipotiroidismo congénito (n=67) y un grupo control (n=67). Se analizó la mineralización ósea por densitometría, y se tuvo en cuenta la edad, el sexo, la maduración ósea y sexual, el diagnóstico hormonal y el tratamiento. Se aplicaron intervalos de confianza (95 por ciento), análisis de varianza y correlación con significación. Resultados: la densidad, el contenido mineral óseo y el z-score en niños cubanos con hipotiroidismo congénito, y el grupo control no fue diferente significativamente (p=0,466; 0,155; 0,416 respectivamente). Estimaciones de asociación de mineralización ósea por edad mostró diferencia significativa en la densidad mineral ósea y contenido mineral óseo (p=0,000) para ambos grupos, y el z-score solo para los enfermos. La mineralización ósea fue significativa en la dosis promedio con levotiroxina en la segunda y tercera fase ósea, y en el tiempo de tratamiento. En el hipotiroidismo congénito permanente hubo correlación con el diagnóstico hormonal y el tiempo de tratamiento (p=0,000). Conclusiones: la mineralización ósea es homogénea en ambos grupos. La densidad y el contenido mineral óseo en niños cubanos con hipotiroidismo congénito y el grupo control se asocian con la edad, y son independientes del sexo. El z-score en pacientes con hipotiroidismo congénito sufre variación con la edad, y es independiente al sexo en ambos grupos. La densidad y el contenido mineral óseo varían en niños con hipotiroidismo congénito(AU)

Introduction: in the case of the congenital hypothyroidism the bone mineralization may be affected by disease or by the effects of the thyroid hormones treatment. Objective: to determine the bone mineralization in patients presenting with congenital hypothyroidism. Methods: a cross-sectional, matched and descriptive study was conducted in Cuban children with congenital hypothyroidism (n= 67) and a control group (n= 67). The bone mineralization was analyzed by densitometry taking into account age, sex, bone and sexual maturation, hormonal diagnosis and treatment. The 95 percent CI were applied, variance analysis and correlation with significance. Results: density, bone mineral content and z-score in Cuban children with congenital hypothyroidism and the control group there was significantly different (p= 0,466; 0,155; 0,416), respectively. The estimations of bone mineralization association according to age showed a significant difference in bone mineralization density and the bone mineral content (p= 0,000) for both groups, and the z-score only for the sick persons. The bone mineralization was marked in mean dose with levothyroxine during the second and third bone phase and the treatment time. In the case of permanent congenital hypothyroidism there was a correlation with hormonal diagnosis and the treatment time (p= 0,000). Conclusions: the bone mineralization is homogeneous in both groups. Density and bone mineral content in Cuban children with congenital hypothyroidism and the control group are associated with age independently of sex in both groups. Density and bone mineral content are different in the children with congenital hypothyroidism(AU)

In vivo bone response and interfacial properties of titanium-alloy implant with different designs in rabbit model with time.

Background: Using implants for dental applications are well-accepted procedures as one of the solutions for periodontal defect repair. Suitable design and materials, their reaction with the surrounding hard tissues and interfacial biomechanical properties are still considered to be the primary criteria which need to be addressed systematically. In the present study, a thorough and systemic approach was made to identify a suitable implant, considering the above criteria after both in vitro and in vivo animal trials. Materials and Methods: Titanium alloy (Ti-6Al-4V) implants, with thread and without thread models, were implanted to the mid-metaphysial portion of the tibia of the right hind leg of three white Australian Chinchilla rabbit species and their effects and response to the surrounding bone were investigated. Parameters studied included hematological and biochemical features (serum alkaline phosphatase and calcium), both preoperatively and postoperatively, consecutively for 7 days and after 1-3 months. The interfacial integrity and compositional variation along the interface were studied using scanning electron microscope (SEM) with energy dispersive analysis of X-ray (EDAX) and histopathology from 1 to 3 months consecutively. Finally, biomechanical properties were studied with the help of push-out test. Results: Bone remineralization started through the process of electro-physiological ionic exchanges, which helps in formation of osteoblastic cells in the area of bony injury. The SEM-EDAX results confirmed the initial stability for the Ti (with thread) implant, but the regeneration of new bone formation was faster in the case of Ti (Without thread) implant, and hence could be used for faster healing. These have also been substantiated through push-out and histopathlogical tests. Conclusion: From the physico-chemical and biomechanical observations, it was found that that smooth type implants were well accepted in the physiological condition although chances of elemental leaching from the surface were also observed. Increase of the surface roughness can help into the formation of physico-chemical bondage with the surrounding hard tissues.

Bone regeneration in surgically created defects filled with autogenous bone: an epifluorescence microscopy analysis in rats

Although the search for the ideal bone substitute has been the focus of a large number of studies, autogenous bone is still the gold standard for the filling of defects caused by pathologies and traumas, and mainly, for alveolar ridge reconstruction, allowing the titanium implants installation. OBJECTIVES: The aim of this study was to evaluate the dynamics of autogenous bone graft incorporation process to surgically created defects in rat calvaria, using epifluorescence microscopy. MATERIAL AND METHODS: Five adult male rats weighing 200-300 g were used. The animals received two 5-mm-diameter bone defects bilaterally in each parietal bone with a trephine bur under general anesthesia. Two groups of defects were formed: a control group (n=5), in which the defects were filled with blood clot, and a graft group (n=5), in which the defects were filled with autogenous bone block, removed from the contralateral defect. The fluorochromes calcein and alizarin were applied at the 7th and 30th postoperative days, respectively. The animals were killed at 35 days. RESULTS: The mineralization process was more intense in the graft group (32.09 percent) and occurred mainly between 7 and 30 days, the period labeled by calcein (24.66 percent). CONCLUSIONS: The fluorochromes showed to be appropriate to label mineralization areas. The interfacial areas between fluorochrome labels are important sources of information about the bone regeneration dynamics.

Proteoliposomes as matrix vesicles' biomimetics to study the initiation of skeletal mineralization

During the process of endochondral bone formation, chondrocytes and osteoblasts mineralize their extracellular matrix by promoting the formation of hydroxyapatite (HA) seed crystals in the sheltered interior of membrane-limited matrix vesicles (MVs). Ion transporters control the availability of phosphate and calcium needed for HA deposition. The lipidic microenvironment in which MV-associated enzymes and transporters function plays a crucial physiological role and must be taken into account when attempting to elucidate their interplay during the initiation of biomineralization. In this short mini-review, we discuss the potential use of proteoliposome systems as chondrocyte- and osteoblast-derived MVs biomimetics, as a means of reconstituting a phospholipid microenvironment in a manner that recapitulates the native functional MV microenvironment. Such a system can be used to elucidate the interplay of MV enzymes during catalysis of biomineralization substrates and in modulating in vitro calcification. As such, the enzymatic defects associated with disease-causing mutations in MV enzymes could be studied in an artificial vesicular environment that better mimics their in vivo biological milieu. These artificial systems could also be used for the screening of small molecule compounds able to modulate the activity of MV enzymes for potential therapeutic uses. Such a nanovesicular system could also prove useful for the repair/treatment of craniofacial and other skeletal defects and to facilitate the mineralization of titanium-based tooth implants.

Enhanced bone apposition to Brazilian microrough titanium surfaces

It has recently been reported that machined and microrough (micro) Brazilian titanium (Ti) implants have good production standards. The aim of this study was to evaluate in vivo bone formation around 2 different implant surfaces placed in dog's mandible. Thirty-two screw-typed Ti implants were used in this study. Mandibular premolars were extracted in 8 dogs and, after 12 weeks, 2 machined (Neodent Titamax, Brazil) and 2 micro implants (Neodent Titamax Porous, Brazil) were placed in each animal. Biopsies were taken at 3 and 8 weeks post-implantation and stained with Stevenel's blue and Alizarin red for histomorphometric measurements of bone-to-implant contact (BIC), bone area between threads (BABT) and bone area within the mirror area (BAMA). Data were analyzed statistically by two-way ANOVA (á=0.05). While at 3 weeks micro implants exhibited significantly more BIC than machined ones (55 ± 12.5 percent and 35.6 ± 15 percent, p<0.05), no significant difference in such parameter was detected at 8 weeks (51.2 ± 21 percent and 48.6 ± 18.1 percent, p>0.05). There were no significant differences in BABT and BAMA between the implants. Micro surfaces promoted higher contact osteogenesis. These data indicate that this commercial micro Ti implant surface enhances contact osteogenesis at an early post-implantation period when compared to the machined one.

Estudos recentes demonstram que implantes nacionais de titânio (Ti) usinados e micro-rugosos apresentam padrões adequados de produção. O objetivo deste estudo foi de avaliar a neo-formação óssea in vivo em 2 tipos diferentes de implantes colocados em mandíbulas de cães. Trinta e dois implantes rosqueáveis de Ti foram utilizados neste estudo. Os pré-molares mandibulares de 8 cães foram extraídos e, após 12 semanas, 2 implantes usinados (Neodent Titamax) e 2 implantes micro-rugosos (Neodent Titamax Porous) foram colocados em cada animal. Após 3 e 8 semanas da implantação os espécimes foram biopsiados, corados com Stevenel's blue e Alizarin red e analisados histomorfometricamente quanto à porcentagem de contato-osso-implante (COI), área de osso mineralizado entre as roscas (OMER) e área de osso mineralizado na área em espelho (OMAE). Os resultados foram analisados estatisticamente pelo teste de ANOVA a dois fatores. Os implantes micro-rugosos apresentaram maior COI do que os implantes controle em 3 semanas (55,0 ± 12,5 por cento e 35,6 ± 15,0 por cento; p<0,05), enquanto não houve diferença em 8 semanas (51,2 ± 21,0 por cento e 48,6 ± 18,1 por cento; p>0,05). Não houve diferença quanto ao OMER e OMAE. Esses dados nos indicaram que os implantes micro-rugosos utilizados neste estudo aumentam a osteogênese de contato nos períodos iniciais pós-implantação quando comparados com implantes usinados.

Análisis descriptivo de la reparación ósea asociada a implantes dentales endóseos instalados en perros con técnica sumergida en dos períodos de evaluación / Descriptive analyses of osseous repair related to endosseous dental implant installed in dogs with submerged technique in two evaluation period

Los implantes oseointegrados forman parte de la práctica clínica en diferentes disciplinas de la rehabilitación funcional y estética del hombre donde el área de la odontología no es una excepción; de esta forma, los implantes dentales son una respuesta a la gran demanda de paciente con edentulismo parcial o total. Existe una importante y creciente investigación en implantología, siendo imperativo reconocer las características histológicas de la reparación ósea cuando son instalados implantes dentarios. El objetivo de esta investigación es reconocer las características histológicas descriptivas de la reparación ósea asociada a la instalación de implantes dentales en dos periodos de evaluación. El modelo experimental utilizado en este estudio correspondió al de cinco perros sometidos a la exodoncia de premolares mandibulares bilaterales. Después de tres meses fueron instalados implantes bilaterales con dos diseños diferentes y con diferentes protocolos de carga. Los sacrificios de los animales fueron realizados después de tres y seis semanas de instalados los implantes. El estudio histológico descriptivo se desarrolló en el tejido adyacente a implantes instalados con técnica sumergida. Se observaron características de reparación ósea en los dos periodos de evaluación. El periodo de tres semanas presento tejido mineralizado en contacto con el implante y tejido conectivo no mineralizado en aumento desde la región superior hacia la inferior. Las regiones de reparación ósea fueron relacionadas con fenómenos de angiogénesis adyacentes. A las seis semanas se observo una mayor formación ósea, reemplazando las áreas de tejido conectivo no mineralizado por tejido mineralizado. Se observo también tejido óseo maduro con canales de Havers bien constituidos. Concluimos que existe una secuencia biológica de reparación ósea respetada en los dos periodos de evaluación, donde después de seis semanas es posible observar un tejido óseo bien constituido, teóricamente ...

Osseointegrated implants are a part of clinical practice in different areas of the aesthetic and functional human rehabilitation where dentistry is not an exception; being like that, dental implants are a responses to great necessity of patient with partial or total dental lost. Exist an important and crescent research in implantology, being very important to recognize the histological characteristic of the osseous repair when dental implant are installed. The aim of this research was to recognize the histological descriptive characteristic of the osseous repair in two evaluation period. The experimental model in this research was five dogs submitted to dental extraction of mandibular bilateral bicuspid. After three month were installed bilateral implants with two implants design and different load protocols. The animals' sacrifices were realized three and six weeks after implants installation. The histological evaluation was realized in a tissue of implant with submerged techniques. Was observed osseous repair characteristic for two evaluation period. For three weeks period was observed mineralized tissue in contact with implant and non mineralized connective tissue in increase from superior to inferior areas. Reparation areas were related to adjacent angiogenic phenomena. For sex weeks period, was observed a major osseous formation, change connective tissue for mineralized tissue. Was observed too matures osseous tissue with well formed Havers channel. We conclude that exist a biological sequence of osseous repair present for a two evaluation period, where in a sex weeks is observed osseous tissue with good definition, theoretically capable for stress support.

Growth and bone mineralization in patients with juvenile idiopathic arthritis.

OBJECTIVE: To investigate growth, development and bone mineralization of children with juvenile idiopathic arthritis (JIA). METHODS: Thirty patients between 4-17 years of age (mean 11.34 +/- 3.88) resistant to therapy were studied. Enrollment began in November 1999 and continued through November 2004 and children with chronic disease were excluded. Data like height, weight, medications and acute phase reactants were obtained from medical records. On study-visit, puberty was assessed by physical examination and bone mineral density (BMD) was measured. Serum Ca, P, ALP, insulin-like growth factor-1 (IGF-1) and urinary Ca/Cr and hydroxyproline /Cr levels were measured. Results were compared with the control group that consisted of 30 cases of similar age and gender. RESULTS: Patients with JIA had decreased height standard deviation score (SDS) and growth retardation. BMD of the cases in the study group was lower than the control group (p< 0.05). Patients who were at younger age at the onset of the disease had lower BMD. Among the drugs, only steroids had a negative effect on growth. Serum IGF-1 levels of the study group were significantly lower than the control group (p< 0.0001). CONCLUSION: Early diagnosis and suppression of disease activity is important in prevention of osteoporosis and growth retardation in children with JIA. BMD has to be measured yearly in patients for accurate diagnosis of osteoporosis. Vitamin D and Ca-rich nutrition with promotion of physical activity and controlled use of steroids may protect the children against bone loss.

Bone mineralization in Brazilian adolescents: the years of maximum bone mass incorporation

Puberty is the fundamental period for bone mass (BM) acquisition. In this period mineralization is found to increase with levels of high bone formation. The critical years of intense bone anabolism deserve special attention, as adequate gain could minimize fracture risk in later years. The objective of this work was to study bone mineral content (BMC) and bone mineral density (BMD) in male adolescents with age bracket and maturation level. Sixty-one healthy male 10 to 19 year-olds were evaluated for calcium intake, weight, stature, BMI, puberty stage and BMC and BMD in the lumbar spine and femur. BM was measured by bone densitometry (DXA). Calcium intake was calculated by recording 3 days diet. Puberty stage was defined as per Tanner. Descriptive statistics was used with means and standard deviations, linear correlation, and analysis of variance for comparison between age groups, and the Tukey test (p<0.05). Linear correlation was positive and indicated body weight as the main correlation variable with BMD in both studied locations (p<0.01). BMC and BMD increased with age, differences were significant from 14 to 15 years, and when adolescents reached Tanner stage G4. These results showed a pronounced increase in bone mineralization, with the years after 14 to 15 being critical for BM acquisition in Brazilian adolescents.

Mineralización ósea en adolescentes brasileños: años de máxima incorporación de masa ósea. La pubertad es un momento fundamental para la adquisición de la masa ósea (MO). En este período, la mineralización se encuentra en aumento en los niveles de formación ósea. Los años críticos de intenso anabolismo óseo necesitan de atención, porque el adecuado aumento de la masa ósea podría minimizar el riesgo de fracturas en los años posteriores. El objetivo de esta investigación fue estudiar el contenido mineral óseo (CMO) y la densidad mineral ósea (DMO) en adolescentes según el grupo de edad y el nível de maduración. Sesenta y un adolescentes saludables de 10 a 19 años fueron evaluados cuanto a la ingesta de calcio, peso, estatura, índice de masa corpórea (IMC), etapa puberal, CMO y DMO en la columna lumbar y en el fémur. La MO fue medida por densitometría ósea (DEXA). La ingesta de calcio fue calculada mediante un recordatorio de ingesta de tres días. La etapa puberal fue definida por los criterios de Tanner. Estadística descriptiva fue utilizada con media y desviación estándar, correlación linear y análisis de varianza para comparar los grupos y test de Tukey (p<0,05). Correlación linear fue positiva e indicó que el peso corporal fue la principal variable correlacionada con la DMO en los dos sitios estudiados (p<0,01). CMO y DMO aumentaron con la edad y las diferencias fueron considerables de los 14 a los 15 años, cuando los adolescentes alcanzaban la etapa G4 de Tanner. Estos resultados muestran un aumento pronunciado en la mineralización ósea; entre los 14 y 15 años fueron críticos para la adquisición de MO en adolescentes brasileños.

El eje hueso-riñón en el control del fósforo sérico y la mineralización ósea / Bone-Kidney axis in the control of serum phosphorus and bone mineralization

El eje hueso-riñón ha sido pensado como un mecanismo por el cual el esqueleto se comunica con el riñón para coordinar la mineralización de la matriz extracelular ósea con el manejo renal del fosfato. Osteoblastos /osteocitos están bien preparados para coordinar las homeostasis sistémica de fósforo y la mineralización ósea, ya que ellos expresan todos los componentes implicados en un posible eje hueso-riñón, incluyendo al PHEX, FGF-23, MEPE, y DMP1. Los efectos autocrinos de proteínas de la familia SIBLING como MEPE y DMP1 sobre los osteoblastos podrían regular la producción de proteínas de matriz extracelular que intervienen en la mineralización. El riñón provee uno de los efectores de este eje que regula el balance de fosfato a través de la expresión apical de los cotransportadores sodio/fosfato NaPi-IIa y NaPi-IIc en el túbulo proximal. Central en este eje es el FGF-23, producido por los osteoblastos que tiene acciones fosfatúricas sobre el riñón. Cuando se descubrió que el FGF23, la primera fosfatonina era de origen osteoblástico/osteocitico, quedó establecido el eje hueso-riñón. Probar definitivamente la existencia de este eje hueso-riñón y definir exactamente su rol fisiológico requerirá de investigaciones adicionales

The bone-kidney axis has been thought as a mechanism for the skeleton to communicate with the kidney to coordinate the mineralization of extracelular matrix with the renal handling of phosphate. Osteoblasts / osteocytes are well suited for coordinating systemic phosphate homeostasis and mineralization, since they express all of the implicated components of a possible bone-kidney axis, including PHEX, FGF-23, MEPE, and DMP1. In addition, autocrine effects of SIBLING proteins as MEPE and DMP1 on osteoblasts could regulate the production of ECM proteins that regulate mineralization. The kidney provides one of the effectors of the axis that regulates phosphate balance through the apical expression of NaPi-IIa and NaPi-IIc in proximal tubules. Central in this axis is FGF-23, produced by osteoblasts that has phosphaturic actions on the kidney. When FGF23, the first phosphatonin, was discovered to be of osteoblastic/osteocyte origin, the bone kidney axis was established. Proving the existence of this bone-kidney axis and defining its physiological role will require additional investigations

Bone tissue microscopic findings related to the use of diode laser (830etam) in ovine mandible submitted to distraction osteogenesis

PURPOSE: To analyze the microscopic characteristics of the effect of Gallium-Aluminum Arsenid diode laser (GaAlAs - 830etam) applied during the activation and consolidation period to ovine mandibles submitted to distraction osteogenesis. METHODS: Eighteen sheep underwent surgery in order to have bone distractors implanted in the left side of the jaw area. They were divided into three groups: 1 - Control; 2 - Laser irradiation during the activation period; 3 - Laser irradiation during the fixation period. The irradiation was carried out in five sessions, on every other day, with 4,0J/cm² doses applied to four pre-established areas, totaling 16J per session. After four days of latency under post-operative care, ten days of distractor activation (at 1mm/day) and twenty-one days of fixation the animals were sacrificed and the devices removed for microscopic analysis. RESULTS: The groups that received laser irradiation (GaAlAs) presented a greater amount of mineralized bone trabeculae when compared to the Control Group. Despite that, cartilaginous tissues were also found in Group 2. CONCLUSION: The laser has been more favorable when used in the consolidation period, after bone elongation.

OBJETIVO: Avaliar as características microscópicas do efeito do laser diodo de Arsenieto de Gálio-Alumínio (AsGaAl - 830etam), aplicado no período de ativação e consolidação de mandíbulas de ovelhas submetidas a distração osteogênica. MÉTODOS: Dezoito ovinos foram submetidos a procedimento cirúrgico para colocação de distrator ósseo em região de mandíbula do lado esquerdo, sendo divididos em três grupos: 1 - Controle; 2 - Irradiação de laser no período de ativação; 3 - Irradiação de laser no período de contenção. As irradiações foram feitas em cinco seções em dias alternados, com doses de 4,0J/cm² em quatro pontos pré-determinados, somando 16J por seção. Após quatro dias de latência no pós-operatório, 10 dias de ativação do distrator (1 mm/dia) e 21 dias de contenção os animais foram mortos e as peças removidas para análise microscópica. RESULTADOS: Os resultados foram que os grupos irradiados com laser (AsGaAl) apresentaram maior disposição de trabéculas ósseas mineralizadas em relação ao grupo controle, contudo, no Grupo 2 foi observada a presença de tecido cartilaginoso. CONCLUSÃO: O laser atuou de forma mais favorável quando utilizado no período de consolidação, após o alongamento ósseo.

Comparação dos métodos de imagem no diagnóstico dos tumores renais e calcificações nestas neoplasias / Comparison of imaging methods for diagnosis of renal tumors and their calcifications

OBJETIVO: Tentar estabelecer uma metodologia no diagnóstico e conduta dos pacientes com massas renais sólidas e complexas, comparando os custos e benefícios dos diferentes métodos de diagnóstico por imagem. Procuramos avançar no diagnóstico diferencial entre lesões benignas e malignas, particularmente através da investigação das calcificações tumorais. MÉTODOS: Realizamos um estudo prospectivo em 31 pacientes portadores de massas renais sólidas ou complexas, todos eles submetidos à ultra-sonografia abdominal (US), ultra-sonografia doppler da massa renal (US Dop), tomografia computadorizada (TC) e ressonância magnética (RM). RESULTADOS: Encontramos 28 pacientes com massas malignas e três com massas benignas. Entre os 28 pacientes com lesões malignas, 17 mostraram calcificações pela TC; 16 deles calcificações do tipo central e um calcificação do tipo curvilinear periférica pura (casca de ovo). A urografia excretora (UGE) mostrou uma taxa de detecção para calcificações significantemente menor que a US e a TC. Massas benignas e malignas apareceram como descrito na literatura, com o US, TC e RM mostrando alta sensibilidade e especificidade no diagnóstico dos tumores renais. A exceção foi na US Dop, onde nós obtivemos menor sensibilidade para a caracterização de fluxo tumoral maligno. CONCLUSÕES: Foi surpreendente verificar que a TC revelou calcificações centrais em 51,6 por cento dos pacientes desta série, todas elas em lesões malignas, quando a literatura refere uma freqüência de calcificações entre 8 por cento e 22 por cento dos carcinomas de células renais, em estudos utilizando radiografias simples do abdômen e UGE. Este achado é de grande importância quando consideramos que estas calcificações ocorrem particularmente em neoplasias malignas. Como resultado da comparação dos diferentes métodos de diagnóstico por imagem, nós propomos uma metodologia para adequada investigação dos tumores renais.