Navegando por Palavras-chave "Bone"

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    Alterações morfológicas do tecido cartilagíneo e ósseo do fêmur de ratos jovens submetidos à lesão térmica
    (Universidade Federal de São Paulo (UNIFESP), 2015-03-24) Tomé, Tabata de Carvalho [UNIFESP]; De Oliveira, Flavia [UNIFESP]; http://lattes.cnpq.br/3387760393535776; http://lattes.cnpq.br/6739253308521471; Universidade Federal de São Paulo (UNIFESP)
    The scald burn injury (SBI) mainly affects children and is a serious public health problem and it is clear the extensive tissue destruction, leading to the activation of catabolic processes. There are numerous descriptions related to changes in growth and bone mineral density in patients who have suffered thermal injuries, but there are few studies investigating the cellular events responsible for these changes. This study aims to understand the cellular mechanisms involved in the possible bone loss and cartilage of the femur of an experimental model of t hermal injury (> 40% of body surface) in young rats. 28 rats were divided into groups: control (C) and scald burn injury (SBI), further subdivided in ratings of 4 and 14 days after injury. The femur was removed for histological and morphometric analysis of the epiphyseal plate and of articular cartilage; analysis of collagen type I and III of the cartilage and bone regions; immunohistochemical analysis (MMP-2 and 9, RUNX-2 and RANKL). Statistical analysis by variance analysis (ANOVA) with two factors (time and group) was performed. The results of the histopathological analysis demonstrated differences in the delay of the appearance of secondary ossification center, decreased cellularity in the middle layer of the articular cartilage, and the presence of chondrocytes in the spongy bone substance the animals SBI. In addition, there were differences in the predominant type of collagen LTE group when compared to C. The immunohistochemical analysis for MMP-2 and MMP-9 showed more intense immunostaining in C groups compared to SBI. There was increased RUNX-2 immunoreactivity (related to the differentiation of osteoblasts) and RANK-L (stimulating factor for the development and maturation of osteoclasts). The morphometric analysis allowed to point thinning of the epiphyseal plate and its layers in SBI animals but without changing the cell density of chondrocytes of the middle layer of the articular cartilage and also without changing the area of the same chondrocytes. The data showed that the thermal damage of great extent affected the cartilage and bone of the femur of young rats, in order to delay bone growth in SBI animals. Strategies to prevent such processes are essential for the treatment of thermal injuries.
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    Análise biomecânica, morfológica e da resposta nociceptiva em modelo animal de Mucopolissacaridose tipo I
    (Universidade Federal de São Paulo (UNIFESP), 2019-02-28) Ferreira, Nicole Yolanda [UNIFESP]; D'Almeida, Vania [UNIFESP]; Pereira, Vanessa Gonçalves [UNIFESP]; http://lattes.cnpq.br/4126672233843478; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4785189U3; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4471024Y5; Universidade Federal de São Paulo (UNIFESP)
    Mucopolysaccharidoses (MPS) are a group of inborn errors of metabolism (IEM), in which specific lysosomal enzymes that participate of glycosaminoglycan (GAG) degradation are deficient or inactive. Musculoskeletal impairment is an important component of the morbidity related to the disease, once it causes a major impact in patients’ health and life quality. Characteristics such as decreased enzyme activity and lysosomal storage in different types of cells are observed in MPS I murine models, making them an important and reliable tool for better understanding the pathogenic mechanisms of the disease. Despite all existing evidence regarding musculoskeletal alterations in MPS I, it is still unclear how these influence bone matrix quality and its biomechanical properties. Objective: Evaluate the nociceptive response to heat in 3 and 6-month old wild type (Idua +/+) and MPS I knockout mice (Idua -/-), as well as bone matrix morphological, biomechanical, and histological properties. Method: Nociceptive response to heat from 3 and 6-month old wild type (Idua +/+) and MPS I knockout mice (Idua -/-) was evaluated. In addition, morphological, biomechanical, and histological analysis of femurs from the same group of animals were perfomed. Results and conclusions: No difference was observed in the nociceptive response to heat for all animal groups ang ages. Femurs from 3-month old Idua -/- mice were found to be smaller and less resistant to fracture when compared to their age matched controls. Also, at this age, femurs from 3-month old Idua - /- mice presented important alterations in articular cartilage, trabecular bone architecture, and collagen types I and III deposition. At 6 months of age, femurs from Idua -/- mice were more resistant to fracture than those from Idua +/+. Our results suggest that the clear abnormalities observed in bone matrix and articular cartilage in 3-month old Idua -/- animals caused bone tissue to be less flexible and more likely to fracture, whereas in 6-month old Idua -/- group the ability to withstand more load before fracturing than wild type animals might suggest that at this age bones become more resistant than at 3 months of age.
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    Avaliação do colágeno no osso de ratas diabéticas tipo 1 tratadas com isoflavonas
    (Universidade Federal de São Paulo, 2022-11-29) Vieira, Magno César [UNIFESP]; Simões, Manuel de Jesus [UNIFESP]; Carbone, Adriana Aparecida Ferraz [UNIFESP]; http://lattes.cnpq.br/9174521191304809; http://lattes.cnpq.br/5987164343458678; http://lattes.cnpq.br/5998705224419140
    Neste trabalho, o modelo “ratas diabéticas ovariectomizadas” foi utilizado pensando nas mulheres em menopausa e diabéticas com um tratamento alternativo com isoflavonas da soja, baseamo-nos em dados que mostram um aumento no número de mulheres que procuram utilizar-se de terapias hormonais. Objetivo: Analisar a matriz extracelular no osso de ratas diabéticas tratadas com isoflavonas ou 17β- estradiol. Métodos: Foram utilizadas 60 ratas (Rattus norvegicus albinus), fêmeas, adultas, ±3 meses de idade. Os animais foram separados em seis (6) grupos, a saber: controle Sham (n=10) animais não ovariectomizados na fase de estro; Sham+DM (n=10) controle Sham ratas diabéticas não ovariectomizadas na fase de estro; OVX (n=10) controle, ratas ovariectomizadas que receberam veículo propilenoglicol; OVX+DM (n=10) ratas diabéticas ovariectomizadas que receberam veículo propilenoglicol (fase de estro); OVX+DM+ISO (n=10) animais diabéticos ovariectomizados tratados com isoflavonas da soja (150mg/Kg, por gavagem); OVX+DM+E2 (n=10) animais diabéticos ovariectomizados tratados com estrogênio (17β-estradiol, 10μg/Kg, por via subcutânea). Para a indução do diabetes Tipo 1, as ratas receberam uma única injeção intraperitoneal de 60 mg/Kg de estreptozotocina (STZ, Sigma-Aldrich). O diabetes foi confirmado três dias após a injeção da estreptozotocina. Todos os animais foram tratados durante 30 dias consecutivos, e ao final, os animais foram anestesiados e os fêmures removidos e processados para estudo em H.E. e Picro Sirius Red. Para a análise dos resultados foi utilizado Oneway ANOVA seguido do teste de Tukey. Foram considerados estatisticamente significativos experimentos cujo valor de p foi menor que 5% (p ≤ 0,05) para significância estatística. Os cálculos foram feitos com o programa SPSS versão13 (SPSS, Chicago, IL). Resultados: Os resultados obtidos foram os seguintes: Peso corporal: não foi diferente entre os grupos não diabéticos Sham e OVX e, os grupos de ratas diabéticas Sham+DM, OVX+DM, OVX+DM+ISO e OVX+DM+E2 (p>0,05). No entanto, houve uma diminuição significativa do peso corporal nos grupos de ratas diabéticas em comparação com os grupos não diabéticas Sham e OVX (p<0,001). Sensibilidade à Insulina: Os valores mais baixos de insulina tolerância foram observadas no OVX+DM (2,41±0,95). Os grupos Sham (4,64±0,95) e OVX (4,57±0,58) apresentaram os maiores valores de sensibilidade à insulina (p<0,001). x Os grupos OVX+DM+ISO e OVX+DM+E2 apresentaram valores semelhantes, inferiores aos Sham e OVX e superior ao grupo OVX+DM. Histomorfometria e Análise Bioquímica de Glicosaminoglicanos Sulfatados: O volume do osso trabecular foi maior nos grupos de ratas diabéticas ovariectomizadas OVX+DM+E2 (26,35±2,13) e OVX+DM+ISO (18,36±173), tratadas, respectivamente, com 17β estradiol e isoflavonas e menor no OVX+DM (8,32±2,52), grupo de ratas diabéticas ovariectomizadas que receberam veículo propilenoglicol em fase de estro. Resultados semelhantes foram encontrados em relação à espessura do osso cortical, que foi maior no OVX+DM+E2 (398,4±1,74) e OVX+DM+ISO (295,6±1,45) e menor no OVX+DM (142,6±2,74) (p<0,05). Com relação ao sulfato de condroitina foi encontrado nos ossos de todos os grupos de animais estudados. Picro Sirius Red: As fibras colágenas de substância óssea trabecular e cortical das epífises dos fêmures apresentaram maior intensidade de birrefringência nos grupos (OVX+DM+ISO 330,2±2 e OVX+DM+E2 414,8± 33,7) tratados, respectivamente, com isoflavonas e 17β estradiol
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    Biocompatibilidade in vitro da hidroxiapatita extraída de resíduo de peixe (Micropogonias furnieri)
    (Universidade Federal de São Paulo, 2022-01-24) Pires, Larissa Mariano [UNIFESP]; Granito, Renata Neves [UNIFESP]; Prado, João Paulo dos Santos [UNIFESP]; http://lattes.cnpq.br/1803025633941465; http://lattes.cnpq.br/1941145984734628; http://lattes.cnpq.br/3609399669096247; Universidade Federal de São Paulo (UNIFESP)
    O osso é um tecido conjuntivo especializado no qual a matriz orgânica colagênica é mineralizada, uma vez que é permeada por cristais de hidroxiapatita (HAP), um mineral que contribui para as suas propriedades mecânicas. Em casos de fraturas ósseas, a HAP, de diferentes origens, pode ser usada como um biomaterial implantável. Quando extraída de resíduo de peixe, pode constituir uma alternativa econômica e ecologicamente mais viável do que a HAP sintética, visto que este biomaterial natural seria descartado e poderia constituir um problema ambiental. Com base neste cenário, este trabalho teve como objetivo avaliar a citotoxicidade da hidroxiapatita (HAP) extraída de resíduos de peixes (Micropogonias furnieri), bem como a proliferação in vitro e a expressão gênica de células pré-osteoblásticas MC3T3-E1 expostas a um meio condicionado com esse biomaterial natural. A HAP foi extraída de resíduo de peixe e as células pré-osteoblásticas MC3T3-E1 foram cultivadas em meio enriquecido com o biomaterial (HAP) ou em meio de cultura padrão (controle). Após 1, 3 e 6 dias de cultura, foram realizados os teste de alamarBlue, quantificação de DNA (PicoGreen) e RT-PCR, para quantificar a expressão dos genes osteogênicos BPM4 e Runx2. Na avaliação, os estudos de viabilidade celular alamarBlue não indicaram diferenças estatísticas entre os grupos. Por outro lado, após 3 e 6 dias de exposição, a taxa de redução do alamarBlue foi maior nas amostras de HAP indicando maior viabilidade celular. O resultado da quantificação de DNA sugeriu uma menor quantidade de células nos poços contendo meio enriquecido com HAP quando comparadas ao grupo controle. No entanto, como houve maior redução da resazurina em resorufin no teste de alarme Blue, sugerindo maior atividade metabólica das células cultivadas em meio enriquecido com HAP. Não houve diferença significativa na expressão dos genes BPM4 e Runx2. Os resultados indicam que a HAP extraída de carcaça de peixe, um material reaproveitado de resíduos, não apresenta citotoxicidade e pode ter um efeito positivo no metabolismo celular, indicando seu potencial para sua aplicação como biomaterial na engenharia de tecidos.
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    Bone: the final frontier for Staphylococcus aureus penetration in chronic rhinosinusitis
    (Biomed Central Ltd, 2013-07-19) Pezato, Rogerio [UNIFESP]; Bottura, Luciano; Santos, Rodrigo de Paula [UNIFESP]; Voegels, Richard Louis; Bachi, Andre Luis Lacerda [UNIFESP]; Gregório, Luis Carlos [UNIFESP]; Universidade de São Paulo (USP); São Paulo State Mil Police; Universidade Federal de São Paulo (UNIFESP)
    The superantigenic properties of Staphylococcus aureus have been implicated in increasing the inflammatory process in airway diseases. Local formation of IgE antibodies against staphylococcal enterotoxins by secondary lymphoid tissue in nasal polyps has been demonstrated. Staphylococcus aureus is known to colonize the nasal mucosa, and has been found invading the nasal submucosa and intracellularly.Objective: To evaluate the limits of Staphylococcus aureus invasion in the upper airway.Material and methods: Inferior turbinate samples from 3 patients without sinus disease, 6 ethmoid samples from patients with chronic rhinosinusitis with nasal polyposis, and 6 ethmoid samples from patients with chronic rhinosinusitis without nasal polyposis were studied. A fluorescein-labeled PNA probe against Staphylococcus aureus was used to test for the presence of the bacterium in bone (after decalcification) and mucosa.Results: We found Staphylococcus aureus invading the nasal submucosa in patients with nasal polyposis, but no cases of Staphylococcus aureus positivity in bone. in conclusion, we cannot support the hypothesis of nasal bone as a reservoir for Staphylococcus aureus, releasing massive amounts of staphylococcal enterotoxins and eliciting an inflammatory reaction, as occurs with the nasal mucosa.
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    Characterization and biological evaluation of the introduction of PLGA into biosilicate
    (Wiley, 2017) Fernandes, Kelly Rossetti [UNIFESP]; Magri, Angela Maria Paiva [UNIFESP]; Kido, Hueliton Wilian [UNIFESP]; Ueno, Fabio Roberto [UNIFESP]; Assis, Livia [UNIFESP]; Fernandes, Kristianne Porta Santos; Mesquita Ferrari, Raquel Agnelli; Martins, V. C.; Plepis, Ana M.; Zanotto, Edgar Dutra; Peitl Filho, Oscar; Ribeiro, Daniel Araki [UNIFESP]; Van den Beucken, Jeroen J.; Renno, Ana Claudia Muniz [UNIFESP]
    The aims of this study were to characterize different BS/PLGA composites for their physicochemical and morphological characteristics and evaluate the in vitro and in vivo biological performance. The physicochemical and morphological modifications were analyzed by pH, mass loss, XRD, setting time, and SEM. For in vitro analysis, the osteoblast and fibroblast viability was evaluated. For in vivo evaluations, histopathology and immunohistochemistry were performed in a tibial defect in rats. After incubation, all composites presented lower values in pH and mass loss over time. Moreover, XRD and SEM analysis confirmed that the composites degraded over time. Additionally, pore formation was observed by SEM analysis after incubation mainly in BS/PLGA groups. BS/PLGA showed significantly increased in osteoblast viability 24 h. Moreover, BS/PLGA composites demonstrated an increase in fibroblast viability in all periods analyzed when compared to BS. In the in vivo study, after 2 and 6 weeks of implantation of biomaterials, histopathological findings revealed that the BS/PLGA composites degrades over time, mainly at periphery. Moreover, can be observed the presence of granulation tissue, bone formation, Runx-2, and RANKL immunoexpression in all groups. In conclusion, BS/PLGA composites present appropriate physicochemical characteristics, stimulate the cellular viability, and enhance the bone repair in vivo. (C) 2016 Wiley Periodicals, Inc.
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    Comparação dos efeitos do laser de baixa potência e do ultrassom de baixa intensidade no processo de reparo ósseo em tíbia de rato
    (Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia, 2011-06-01) Oliveira, Poliani de; Sperandio, Evandro Fornias; Fernandes, Kelly Rossetti [UNIFESP]; Pastor, Fabio Alexandre Casarin; Nonaka, Keico Okino; Renno, Ana Claudia Muniz [UNIFESP]; Universidade Federal de São Carlos; UFSCar Departamento de Ciências Fisiológicas; Universidade Federal de São Paulo (UNIFESP)
    BACKGROUND: Electrophysical agents such as Ultrasound (US) and low-level laser therapy (LLLT) have been increasingly used in physical therapy practice. Studies suggest that these devices are able to stimulate osteoblast proliferation and osteogenesis at the fracture site, resulting in a greater deposition of bone mass and speeding up the consolidation process. OBJECTIVE: The aim of this study was to analyze the effects of US and LLLT on the bone healing process, through biomechanical and histological analysis of the bone callus. METHODS: A total of 30 rats were randomly allocated into three groups: control group fracture without treatment (GC); fracture group treated with pulsed US, burst 1.5 MHz, 200us, 1KHz, 30 mW/cm² (GUS) and fracture group treated with laser 830nm, 100mW, 120J/cm² (GL). Bone defects were performed with a circular drill of 2mm in diameter in the animal's tibias. The treatments were carried out after surgery consisting of 7 applications every 48 hours. After 14 days the animals were sacrificed and the tibias were removed to perform the analysis, being the right tibia designated for biomechanical analysis, while the left tibia for histological analysis. RESULTS: The biomechanical analysis showed no statistically significant difference between biomechanical properties of the CG, CL and GUS. In morphometric analysis, both GUS and GL showed a significantly higher woven bone tissue area compared to the control group. However, when the two treatment modalities were compared, there were no statistical differences between them. CONCLUSION: Both devices used in this study were able to accelerate the bone healing process in rats.
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    Comparação entre a hidroxiapatita porosa de coral e o enxerto ósseo autógeno em coelhos
    (Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia, 1997-06-01) Figueiredo, Arthur Silveira De; Takita, Luiz Carlos; Goldenberg, Saul [UNIFESP]; UFMS; Universidade Federal de São Paulo (UNIFESP)
    The purpose is to utilize coralline porous hydroxyapatite as osseous xenograft. It was utilized eleven New Zeland rabbits, wich it made pattern defect in the distal femoral mataphise. In this place was used coralline porous hidroxyapatite or autogenous graft. It was made clinical, macroscopic, radiologic and histologic study, with interval of two, four and twelve weeks. The comparatives results was similaries between the two implants types. It was concluded taht coralline porous hidroxyapatite is appropriate replacement for osseos autogenous grafts in rabbits.
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    Comparação entre hidroxiapatita porosa de coral e enxerto ósseo autógeno em coelhos
    (Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia, 2001-09-01) Figueiredo, Arthur Silveira De; Fagundes, Djalma José [UNIFESP]; Novo, Neil Ferreira [UNIFESP]; Juliano, Yara [UNIFESP]; Inouye, Celso Massaschi; Universidade Federal de Mato Grosso do Sul; Universidade Federal de São Paulo (UNIFESP); Universidade Federal de Mato Grosso do Sul Departamento de Clínica Cirúrgica
    The transplantation of autogenous bone continues being used with success, in spite of the disadvantages that it presents, mainly in what refers the increased morbidity, additional operations and increase of the cost. The objective of this research was to verify the integration of the porous hydroxyapatite of chorale as biological alternative in ceramic form to substitute the autogenous bony graft. Forty-two New Zealand rabbits were submitted to na standard condylar defect witch were randomic implanted by autogenous bony graft as porous hydroxyapatite of chorale. We made clinical, macroscopic, radiographic and histologic study among the time of evolution of two, four and twelve weeks, respectively. The results were similar between the autogenous graft and the porous hydroxyapatite of chorale in the evolution of twelve weeks. It was ended that the porous hydroxyapatite of chorale is a substitute adapted to the autogenous bony graft in rabbits.
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    Connexin37 deficiency alters organic bone matrix, cortical bone geometry, and increases Wnt/beta-catenin signaling
    (Elsevier Science Inc, 2017) Pacheco-Costa, Rafael [UNIFESP]; Kadakia, Jay R.; Atkinson, Emily G.; Wallace, Joseph M.; Plotkin, Lilian I.; Reginato, Rejane D. [UNIFESP]
    Deletion of connexin (Cx) 37 in mice leads to increased cancellous bone mass due to defective osteoclast differentiation. Paradoxically
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    Estudo do disco epifisário de camundongos fêmeas lactantes com hiperprolactinemia e seus filhotes
    (Universidade Federal de São Paulo (UNIFESP), 2020-01-30) Araujo Junior, Osvaldo Pereira [UNIFESP]; Simoes, Manuel De Jesus [UNIFESP]; Universidade Federal de São Paulo
    Objective: To evaluate the epiphyseal plate growing (EPG) of offspring de lactating mice with hiperprolactinemia induce by metoclopramida. Materials and Methods: For this purpose, 20 adult female mice were divided into 2 groups with 10 animals/each: control group (GI, Ctr-L) – received the vehicle (0.2 mL saline) and treated group (GII, HPrl-L) – received metoclopramide (200 µg/day dissolved in vehicle). All animals received subcutaneous injections for 50 consecutive days. After 50 days 10 females of each group were placed for mating with males and continued to receive treatment (during pregnancy until 10th day of breastfeeding). The offsprings make four (4) groups: female offsprings (GIII and GIV), and male offspring (GV and GVI) pups of the control group and of the treated group, respectively. After the period of breastfeeding the animals (offsprings) were sacrificed after deep anesthesia and withdrew from the right knee in order to analyze the cartilaginous and bone tissue. The knee was fixed in 10% formaldehyde, decalcification and then subjected to histological processing for inclusion in paraffin. Slides were stained by H&E for morphometric analysis. The hormonal levels were assessed by ELISA and RIA. The results were subjected to statistical analysis by student-t. Results: depth to epiphyseal plate of the female offspring: resting zone (GI: 32,37 r 3,44 µm e GII: 37,32 r 3,42 µm, p < 0.05), proliferating zone (GI: 188,32 r 32,59 µm e GII: 213,18 r 23,06 µm, p < 0.05), e hypertrophic zone (GI: 372,59 r 45,50 µm e GII: 379,59 r 50,13 µm), e male offspring: resting zone (GIII: 33,18 r 3,55 µm e GIV: 34,88 r 3,15 µm), proliferating zone (GIII: 216,67 r 26,27 µm e GIV: 214,47 r 29,84 µm) e hypertrophic zone (GIII: 326,30 r 37,91 µm e GIV: 368,20 r 41,68 µm, p < 0.05). Conclusion: the morphometric results showed alteration of the epiphyseal disk thickness of the female and lactating mother pups with metoclopramide-induced hyperprolactinemia, a fact that suggests compromise in the development of bone growth.
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    Evaluation of a modified pamidronate protocol for the treatment of osteogenesis imperfecta
    (Springer, 2016) Palomo, Telma [UNIFESP]; Andrade, Maria C. [UNIFESP]; Peters, Barbara S. E.; Reis, Fernanda A. [UNIFESP]; Carvalhaes, Joao Tomas A. [UNIFESP]; Glorieux, Francis H.; Rauch, Frank; Lazaretti-Castro, Marise [UNIFESP]
    Intravenous pamidronate is widely used to treat children with osteogenesis imperfecta (OI). In a well-studied protocol ('standard protocol'), pamidronate is given at a daily dose of 1 mg per kg body weight over 4 h on 3 successive days
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    Evidências da ação de agentes físicos sobre o metabolismo do tecido ósseo e seus potenciais usos clínicos
    (Sociedade Brasileira de Endocrinologia e Metabologia, 2005-12-01) Lirani-Galvão, Ana Paula Rebucci [UNIFESP]; Lazaretti-Castro, Marise [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    The action of physical agents such as low level laser therapy, low-intensity pulsed ultrasound and electrical and electromagnetic fields on bone have been often studied, showing that they are able to promote osteogenesis, accelerate fracture consolidation and augment bone mass. The use of these therapeutic modalities was first based on the finding that bone is a piezoelectric material, that means it can generate polarization when deformed, transforming mechanical energy into electric energy, and this has widen therapeutic possibilities to bony tissue. The present work aims to present evidences of physiologic effects and mechanisms of action of these physical agents on bone metabolism, based on articles published in international scientific literature.
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    High Bone Mass in Mice Lacking Cx37 Because of Defective Osteoclast Differentiation
    (Amer Soc Biochemistry Molecular Biology Inc, 2014-03-21) Costa, Rafael Pacheco da [UNIFESP]; Hassan, Iraj; Reginato, Rejane Daniele [UNIFESP]; Davis, Hannah M.; Bruzzaniti, Angela; Allen, Matthew R.; Plotkin, Lilian I.; Indiana Univ Sch Med; Universidade Federal de São Paulo (UNIFESP); Indiana Univ
    Background: Connexin proteins are essential for cell differentiation, function, and survival. Results: Global deletion of Cx37 results in increased bone mass caused by reduced osteoclast maturation. Conclusion: Our findings demonstrate a previously unrecognized role of Cx37 in bone homeostasis in vivo. Significance: Therapeutic approaches to increase bone mass might be developed by interfering with Cx37 function.Connexin (Cx) proteins are essential for cell differentiation, function, and survival in all tissues with Cx43 being the most studied in bone. We now report that Cx37, another member of the connexin family of proteins, is expressed in osteoclasts, osteoblasts, and osteocytes. Mice with global deletion of Cx37 (Cx37(-/-)) exhibit higher bone mineral density, cancellous bone volume, and mechanical strength compared with wild type littermates. Osteoclast number and surface are significantly lower in bone of Cx37(-/-) mice. in contrast, osteoblast number and surface and bone formation rate in bones from Cx37(-/-) mice are unchanged. Moreover, markers of osteoblast activity ex vivo and in vivo are similar to those of Cx37(+/+) littermates. sRANKL/M-CSF treatment of nonadherent Cx37(-/-) bone marrow cells rendered a 5-fold lower level of osteoclast differentiation compared with Cx37(+/+) cell cultures. Further, Cx37(-/-) osteoclasts are smaller and have fewer nuclei per cell. Expression of RANK, TRAP, cathepsin K, calcitonin receptor, matrix metalloproteinase 9, NFATc1, DC-STAMP, ATP6v0d1, and CD44, markers of osteoclast number, fusion, or activity, is lower in Cx37(-/-) osteoclasts compared with controls. in addition, nonadherent bone marrow cells from Cx37(-/-) mice exhibit higher levels of markers for osteoclast precursors, suggesting altered osteoclast differentiation. the reduction of osteoclast differentiation is associated with activation of Notch signaling. We conclude that Cx37 is required for osteoclast differentiation and fusion, and its absence leads to arrested osteoclast maturation and high bone mass in mice. These findings demonstrate a previously unrecognized role of Cx37 in bone homeostasis that is not compensated for by Cx43 in vivo.
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    Low-level laser therapy associated to a resistance training protocol on bone tissue in diabetic rats
    (Sbem-Soc Brasil Endocrinologia & Metabologia, 2016) Patrocinio-Silva, Tatiane Lopes; Souza, André Moreira Fogaça de [UNIFESP]; Goulart, Raul Loppi [UNIFESP]; Pegorari, Carolina Fuirini [UNIFESP]; Oliveira, Jussan Rodrigues [UNIFESP]; Fernandes, Kelly Rossetti [UNIFESP]; Magri, Angela Maria Paiva [UNIFESP]; Pereira, Rosa Maria Rodrigues; Ribeiro, Daniel Araki [UNIFESP]; Nagaoka, Márcia Regina [UNIFESP]; Renno, Ana Claudia Muniz [UNIFESP]
    Objective: The present study aimed to evaluate the in vivo response of a resistance training and low-level laser therapy (LLLT) on tibias and femurs of rats with diabetes mellitus (DM). Materials and methods: Forty male Wistar rats were randomly distributed into four experimental groups: control group (CG), diabetic group (DG), diabetic trained group (TG) and diabetic trained and laser irradiated group (TLG). DM was induced by streptozotocin (STZ) and after two weeks laser and resistance training started, performed for 24 sessions, during eight weeks. At the end of the experiment, animals were euthanized and tibias and femurs were removed for analysis. Histological, histomorphometrical, immunohistochemistry and mechanical analyses were performed. Results: Trained groups, with or without laser irradiation, showed increased cortical area, bone density and biomechanical properties. The immunohistochemical analysis revealed that TG and TLG demonstrated an increased RUNX2 expression. RANK-L immunoexpression was similar for all experimental groups. Conclusion: In conclusion, it can be suggested that the resistance exercise program stimulated bone metabolism, culminating in increased cortical tibial area, bone mineral content, bone mineral density and biomechanical properties. Furthermore, the association of physical exercises and LLLT produced higher values for bone mineral content and stiffness. Consequently, these data highlight the potential of physical exercise in the management of bone loss due to DM and the possible extra osteogenic stimulus offered by lasertherapy. Further long-term studies should be carried out to provide additional information.
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    Método robusto para reconstrução 3d dos ossos da cavidade torácica em imagens de tomografia computadorizada, utilizando conhecimentos radiológicos, aprendizado de máquina e grafos
    (Universidade Federal de São Paulo (UNIFESP), 2019-03-11) Sais, Barbara Teixeira [UNIFESP]; Moraes, Matheus Cardoso [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    More than 70 million computed tomography (CT) scans are made per year. These exams, especially those directed to the thoracic cavity, are widely required due to the great number of diseases that they help to diagnose, considering the number of organs and structures within it. Objective: The 3D visualization of these structures, including bones, can lead to a more accurate diagnosis, since some details or the own volumetry of the organs may not be correctly evaluated in the 2D slices. There is an extensive literature on 3D bone reconstruction, but most either do not present a quantitative evaluation, or do not reach an accuracy close to 100%. Methods: This work presents an automatic method of bone segmentation followed by 3D reconstruction, addressing such limitations. This method is composed by three blocks: 1. Preprocessing, whereby a median filter was applied to images that presented a high level of noise; 2. Feature Extraction Procedure, in which (i) the images intensity levels were converted to attenuation coefficients and (ii) a (MLP) neural network was used to populate the Space of Attributes with the corresponding feature vectors; and 3. 3D Structural Construction, whereby a red and black tree with graph guidance combined the regarding clustered feature vectors with their spatial neighbors. To evaluate the results, the accuracy between the 2D-segmented images and their corresponding gold standards were calculated. For both the methodology and the evaluation, 90 sets of CT were used, randomly selected within the public image bank used. Results: High accuracy parameters were obtained, such as Overlap Dice (%) = 98.77 ± 0.58 and False Negative (%) = 0.13 ± 0.026. Conclusion: These values show the robustness of the method compared to the other 3D segmentation and reconstruction methods of bone tissue in computed tomography images in the literature.
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    Poly(3-hydroxybutyrate-co-valerate)/poly(3-thiophene ethyl acetate) blends as a electroactive biomaterial substrate for tissue engineering application
    (Royal soc chemistry, 2016) Recco, M. S. [UNIFESP]; Floriano, A. C. [UNIFESP]; Tada, D. B. [UNIFESP]; Lemes, A. P. [UNIFESP]; Lang, R. [UNIFESP]; Cristovan, F. H. [UNIFESP]
    Polyblends of an electroactive biomaterial consisting of a biodegradable polyester - PHBV and a carboxylate polythiophene derivative, the poly(3-thiophene ethyl acetate) - PTAcEt have been prepared and applied as a substrate for tissue engineering. The biodegradable polymer was used as a matrix for polythiophene. Thermal, electrical, optical and morphological properties as well as viability and cell adhesion (in vitro assays) were investigated. Blend films exhibited high flexibility, resistance to handling and a semiconducting character, since they preserved the individual properties of each polymer. Besides, the incorporation of PTAcEt (up to 12%) has led to improvements in the thermal stability and in the crystallinity degree of the bioactive matrix. Qualitative morphological analysis showed irregular and porous surfaces
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    Serum from children with polyarticular juvenile idiopathic arthritis (pJIA) inhibits differentiation, mineralization and may increase apoptosis of human osteoblasts in vitro
    (Springer, 2009-01-01) Caparbo, Valeria F.; Prada, Flavia; Silva, Clovis A. A.; Regio, Paula L.; Pereira, Rosa M. R.; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)
    We examined the effects of polyarticular juvenile idiopathic arthritis (pJIA) serum on proliferation, differentiation, mineralization, and apoptosis of human osteoblast cells (hOb) in culture. the hOb were cultured with 10% serum from active pJIA and healthy controls (CT) and were tested for DNA synthesis, alkaline phosphatase (AP) activity, osteocalcin (OC) secretion, calcium levels, caspase 3 activity, and DNA fragmentation. None of the patients had used glucocorticoids for at least 1 month before the study, or any other drug that can affect bone mineral metabolism. Human inflammatory cytokine levels (IL-6, IL-8, IL-10, IL-1 beta, TNF-alpha, and IL-12p70) were measured in pJIA and CT sera. Low levels of AP activity was observed in pJIA cultures compared with CT cultures (67.16 +/- 53.35 vs 100.11 +/- 50.64 mu mol p-nitrophenol/h(-1) mg(-1) protein, P=0.008). There was also a significant decrease in OC secretion (9.23 +/- 5.63 vs 12.82 +/- 7.02 ng/mg protein, P=0.012) and calcium levels (0.475 +/- 0.197 vs 0.717 +/- 0.366 mmol/l, P=0.05) in pJIA hOb cultures. No difference was observed in cell proliferation (323.56 +/- 108.23 vs 328.91 +/- 88.03 dpm/mg protein, P=0.788). Osteoblasts cultured with JIA sera showed lower levels of DNA and increased fragmentation than osteoblasts cultured with CT sera. pJIA sera showed higher IL-6 values than CT (21.44 +/- 9.31 vs 3.58 +/- 2.38 pg/ml, P<0.001), but no difference was observed related to IL-8, IL-10, IL-1 beta, TNF-alpha, and IL-12p70 between pJIA and controls. This study suggests that serum from children with pJIA inhibits differentiation, mineralization and may increase apoptosis of hOb cultures, and inflammatory cytokines such as IL-6 might be a mechanism in this find. These results may represent an alternative therapeutic target for prevention and treatment of bone loss in JIA.