Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 84.953
Filtrar
1.
Braz. j. biol ; 84: e251970, 2024. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1345559

RESUMO

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.


Assuntos
Animais , Osteogênese , Fosfatase Alcalina/metabolismo , Rana catesbeiana , Osso e Ossos/metabolismo , Cinética
2.
Methods Mol Biol ; 2598: 227-263, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36355296

RESUMO

In this chapter, an introduction is given into histological techniques to research related to hyaline cartilage and subchondral bone. Emphasis is placed on the importance to investigate cartilage and bone as a unit, which includes the transition zone of the calcified cartilage and tidemark. Reasons for the appropriate selection of histological methods are presented such as when to use (decalcified) specimens for routine paraffin embedding including immunohistology, cryosections of cartilage alone, or non-decalcified specimens for embedding in polymethylmethacrylate with or without additional biomaterials. Appropriate staining methods are also outlined. Apart from detailed laboratory protocols for different embedding and staining methods including open communication about difficulties related to the various techniques, also practical instructions for state-of-the-art evaluation methods and their strengths and weaknesses are given. Sample figures for scoring methods are included.


Assuntos
Cartilagem Articular , Cartilagem Articular/patologia , Osso e Ossos
3.
Orthop Clin North Am ; 54(1): 37-46, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36402509

RESUMO

Heterotopic ossification (HO) refers to benign ectopic bone formation in soft tissue and is common following trauma surgery. HO bone can restrict movement and progress into ankylosis that may necessitate surgical intervention. This article discusses the current literature on the pathophysiology, prophylaxis, treatment, and epidemiology of postoperative HO following orthopedic trauma.


Assuntos
Ossificação Heterotópica , Humanos , Ossificação Heterotópica/etiologia , Osso e Ossos , Fatores de Risco
4.
Methods Mol Biol ; 2582: 343-353, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36370362

RESUMO

Bone metastasis and bone destruction are common occurrences in human malignancies, including breast, prostate, and lung cancer, and are associated with a high morbidity rate because of intractable bone pain, pathological fractures, hypercalcemia, and nerve compression. Animal models of bone metastasis and bone destruction are important tools to investigate the pathogenesis and develop treatment strategies. However, there are few models of spontaneous bone metastasis despite the fact that animals often spontaneously develop cancer. Here, we describe methods for developing a mouse model of breast cancer bone metastasis achieved by injection of MDA-MB-231 breast cancer cells into the left cardiac ventricle. In addition, we introduce mouse model of the bone destruction by injection of SAS oral squamous cell carcinoma cells into the bone marrow space of the right tibial metaphysis. These assays can be applied to studies on roles of cellular communication network factor/connective tissue growth factor (CTGF/CCN2) protein in tumor metastasis and development of treatment strategies targeting CCN proteins.


Assuntos
Neoplasias Ósseas , Neoplasias da Mama , Carcinoma de Células Escamosas , Neoplasias Bucais , Camundongos , Masculino , Animais , Humanos , Carcinoma de Células Escamosas/patologia , Neoplasias Bucais/patologia , Neoplasias Ósseas/patologia , Fator de Crescimento do Tecido Conjuntivo/metabolismo , Osso e Ossos/metabolismo , Proteínas , Modelos Animais de Doenças , Neoplasias da Mama/patologia , Linhagem Celular Tumoral
5.
Skeletal Radiol ; 52(1): 39-46, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35882659

RESUMO

Bone biopsy remains the gold standard for diagnosis of osteomyelitis while MRI results in a radiologic diagnosis that generally precedes biopsy. This study's purpose is to examine the diagnostic yield and effect of biopsy results on clinical management in children with suspected osteomyelitis and positive MRI findings. A retrospective review was performed at a tertiary care children's hospital. Search of the EMR and radiology PACS identified patients below 18 years who underwent bone biopsy with interventional radiology for osteomyelitis and had positive MRI findings for osteomyelitis prior to biopsy. Data was collected on patient demographics, MRI findings, biopsy procedural details, tissue culture, histopathology results, and clinical management before and after biopsy. Changes in management were categorized as antibiotic type/quantity, duration, or diagnosis. A total of 82 biopsies in 79 patients with suspicion for osteomyelitis and positive MRIs prior to biopsy were performed over 5 years from 2014 to 2019. All biopsies were successful and sent for tissue culture. 22/82 biopsies (27%) yielded positive cultures. Of those with tissue cultures, 16/22 (72%) resulted in change in clinical management. Of all biopsies, 18/82 (22%) resulted in a change in management (15 antibiotic, 1 duration, 2 diagnosis). The 2 changes in diagnosis included one biopsy done which was positive for cancer and a second which was found to not demonstrate osteomyelitis on histology. In the pediatric population, bone biopsy is a reasonably low morbidity procedure. However, there is a relatively low rate of positive tissue cultures even with MRI findings suspicious for osteomyelitis. Approximately 1 in 5 biopsies resulted in a change in clinical management, mostly in antibiotic selection. Bone biopsy may have a higher clinical impact in pre-specified circumstances.


Assuntos
Osteomielite , Humanos , Criança , Osteomielite/tratamento farmacológico , Biópsia Guiada por Imagem/métodos , Imageamento por Ressonância Magnética , Osso e Ossos/patologia , Biópsia , Antibacterianos/uso terapêutico , Estudos Retrospectivos
6.
J Biomed Mater Res B Appl Biomater ; 111(1): 203-219, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35906778

RESUMO

The use of 3D-printed hydroxyapatite (HA) scaffolds for stimulating bone healing has been increasing over the years. Although all the promising effects of these scaffolds, there are still few studies and limited understanding of their interaction with bone tissue and their effects on the process of fracture healing. In this context, this study aimed to perform a systematic literature review examining the effects of different 3D-printed HA scaffolds in bone healing. The search was made according to the preferred reporting items for systematic reviews and meta-analysis (PRISMA) orientations and Medical Subject Headings (MeSH) descriptors "3D printing," "bone," "HA," "repair," and "in vivo." Thirty-six articles were retrieved from PubMed and Scopus databases. After eligibility analyses, 20 papers were included (covering the period of 2016 and 2021). Results demonstrated that all the studies included in this review showed positive outcomes, indicating the efficacy of scaffolds treated groups in the in vivo experiments for promoting bone healing in different animal models. In conclusion, 3D-printed HA scaffolds are excellent candidates as bone grafts due to their bioactivity and good bone interaction.


Assuntos
Durapatita , Engenharia Tecidual , Animais , Durapatita/farmacologia , Tecidos Suporte , Osso e Ossos , Impressão Tridimensional , Regeneração Óssea
7.
J Mech Behav Biomed Mater ; 137: 105530, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36334581

RESUMO

Bone encompasses a complex arrangement of materials at different length scales, which endows it with a range of mechanical, chemical, and biological capabilities. Changes in the microstructure and characteristics of the material, as well as the accumulation of microcracks, affect the bone fracture properties. In this study, two-dimensional finite element models of the microstructure of cortical bone were considered. The eXtended Finite Element Method (XFEM) developed by Abaqus software was used for the analysis of the microcrack propagation in the model as well as for local sensitivity analysis. The stress-strain behavior obtained for the different introduced models was substantially different, confirming the importance of bone tissue microstructure for its failure behavior. Considering the role of interfaces, the results highlighted the effect of cement lines on the crack deflection path and global fracture behavior of the bone microstructure. Furthermore, bone micromorphology and areal fraction of cortical bone tissue components such as osteons, cement lines, and pores affected the bone fracture behavior; specifically, pores altered the crack propagation path since increasing porosity reduced the maximum stress needed to start crack propagation. Therefore, cement line structure, mineralization, and areal fraction are important parameters in bone fracture. The parameter-wise sensitivity analysis demonstrated that areal fraction and strain energy release rate had the greatest and the lowest effect on ultimate strength, respectively. Furthermore, the component-wise sensitivity analysis revealed that for the areal fraction parameter, pores had the greatest effect on ultimate strength, whereas for the other parameters such as elastic modulus and strain energy release rate, cement lines had the most important effect on the ultimate strength. In conclusion, the finding of the current study can help to predict the fracture mechanisms in bone by taking the morphological and material properties of its microstructure into account.


Assuntos
Fraturas Ósseas , Modelos Biológicos , Humanos , Análise de Elementos Finitos , Osso Cortical , Osso e Ossos , Estresse Mecânico
8.
Magn Reson Med ; 89(2): 767-773, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36226656

RESUMO

PURPOSE: Extend fast, two-dimensional (2D) methods of bound and pore water mapping in bone to arbitrary slice orientation. METHODS: To correct for slice profile artifacts caused by gradient errors of half pulse 2D ultra-short echo time (UTE), we developed a library of predistorted gradient waveforms that can be used to interpolate optimized gradient waveforms for 2D UTE slice selection. We also developed a method to estimate and correct for a bulk phase difference between the two half pulse excitations used for 2D UTE signal excitation. Bound water images were acquired in three healthy subjects with adiabatic inversion recovery prepared 2D UTE, while pore water images were acquired after short-T2 signals were suppressed with double adiabatic inversion recovery preparation. The repeatability of bound and pore water imaging with 2D UTE was tested by repeating acquisitions after repositioning. RESULTS: The library-based interpolation of optimized slice select gradient waveforms combined with the method to estimate bulk phase between two excitations provided compact slice profiles for half pulse excited 2D UTE. Quantitative bound and pore water values were highly repeatable-the pooled SD of bound water across all three subjects was 0.38 mol 1 $$ {}^1 $$ H/L, while pooled SD of pore water was 0.30 mol 1 $$ {}^1 $$ H/L. CONCLUSION: Fast, quantitative, 2D UTE-based bound and pore water images can be acquired at arbitrary oblique orientations after correcting for errors in the slice select gradient waveform and bulk phase shift between the two half acquisitions.


Assuntos
Imageamento por Ressonância Magnética , Água , Humanos , Imageamento por Ressonância Magnética/métodos , Osso Cortical , Osso e Ossos/diagnóstico por imagem , Artefatos
9.
J Mech Behav Biomed Mater ; 137: 105526, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36343520

RESUMO

Natural hydroxyapatite provides certain strength and stiffness to biological bones, and most of the studies on the strength of bone tissues have been carried out on hydroxyapatite (HAP). However, the Ca/P ratio of hydroxyapatite in bones is actually about 1.50, and the natural hydroxyapatite belongs to calcium-deficient hydroxyapatite (CDHA) with Ca vacancy defects. Therefore, this work focused on the effect of Ca vacancy defects on CDHA crystals through investigating the generation and expansion of microcracks under uniaxial tensile loading by combining molecular dynamics and first principles method. A series of crystal models with different Ca vacancy ratios are constructed and find that Ca vacancies degrade the mechanical properties of hydroxyapatite. Meanwhile the fracture behavior of crystals is detailed and find that the cracks arise at vacancies and extend along the direction of vacancies. Also, first-principles calculation is performed to reveal the mechanism of crack formation in MD simulations. It is found that the decrease of Ca-O bonding of CDHA causes the decrease of the stability of the crystal structure by analyzing the DOS of HAP and CDHA, and the cracks originate from Ca vacancies. This work performs more realistic simulations of CDHA with calcium vacancy defects in actual bone tissue and directly reveals the development and progression of bone fragility at the nanometer scale.


Assuntos
Cálcio , Simulação de Dinâmica Molecular , Cálcio/química , Durapatita/química , Osso e Ossos
10.
Colloids Surf B Biointerfaces ; 221: 113008, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36401958

RESUMO

Zinc is a biodegradable candidate material for bone regeneration; however, concomitant implant-related infection and rejection require new solutions to raise the biomedical potential of zinc. Functionalization towards localized drug administration with bioactive frameworks can be a solution. It is herein reported for the first time an eco-friendly approach for coating zinc with multibioactive antibiotic coordination frameworks (ACF). ACF1, a new 1D framework with deprotonated nalidixic and salicylic acids, obtained by mechanochemistry, results from the coordination of Ca(II) centers to the organic acids anions. To maximize ACF1 loading and cells' adhesion, the surface area was increased by creating a porous 3D Zn layer. A coverage of ∼70% of the surface with ACF1, achieved by electrophoretic deposition in an aqueous solution, preserved the desired Zn degradation as |Z| in the order of 103 Ω.cm2 is attained for both bare and coated samples in physiological conditions. The bioactivities of the ACF1 powder are a strong antibacterial activity against Escherichia coli (MIC of 1.95 µg/mL) and weaker against Staphylococcus aureus (MIC of 250 µg/mL), while osteoblasts' cytocompatibility is achieved for concentration ranging between 10 and 100 µg/mL. In its coating form, the degradation of Zn coated with ACF1 results in nalidixic acid release, which may convey antibacterial activity to the implant. The osteoinduction observe over this new biomaterial relates to the precipitation of an apatite layer built from the Ca(II) of ACF1. The work described herein, where unexplored eco-friendly approaches were used, presents a new trend for the design of multibioactive coatings on bioresorbable metallic materials.


Assuntos
Antibacterianos , Zinco , Zinco/farmacologia , Zinco/química , Antibacterianos/farmacologia , Antibacterianos/química , Materiais Revestidos Biocompatíveis/farmacologia , Materiais Revestidos Biocompatíveis/química , Regeneração Óssea , Osso e Ossos , Escherichia coli , Compostos Orgânicos
11.
Ultrasonics ; 127: 106831, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36084514

RESUMO

Decreased thickness of the bone cortex due to bone loss in the course of ageing and osteoporosis is associated with reduced bone strength. Cortical thickness measurement from ultrasound images was recently demonstrated in young adults. This requires the identification of both the outer (periosteum) and inner (endosteum) surfaces of the bone cortex. However, with bone loss, the cortical porosity and the size of the vascular pores increase resulting in enhanced ultrasound scattering which may prevent the detection of the endosteum. The aim of this work was to study the influence of cortical bone microstructure variables, such as porosity and pore size, on the contrast of the endosteum in ultrasound images. We wanted to estimate the range of these variables for which ultrasound imaging of the endosteum is feasible. We generated synthetic data using a two-dimensional time-domain code to simulate the propagation of elastodynamic waves. A synthetic aperture imaging sequence with an array transducer operating at a center frequency of 2.5 MHz was used. The numerical simulations were conducted for 105 cortical microstructures obtained from high resolution X-ray computed tomography images of ex vivo bone samples with a porosity ranging from 2% to 24 %. Images were reconstructed using a delay-and-sum (DAS) algorithm with optimized f-number, correction of refraction at the periosteum, and sample-specific wave-speed. We observed a range variation of 18 dB of endosteum contrast in our data set depending on the bone microstructure. We found that as porosity increases, speckle intensity inside the bone cortex increases whereas the intensity of the signal from the endosteum decreases. Also, a microstructure with large pores (diameter >250 µm) was associated with poor endosteum visibility, compared with a microstructure with equal porosity but a more narrow distribution of pore sizes. These findings suggest that ultrasound imaging of the bone cortex with a probe operating at a central frequency of 2.5 MHz using refraction-corrected DAS is capable of detecting the endosteum of a cortex with moderate porosity (less than about 10%) if the largest pores remain smaller than about 200 µm.


Assuntos
Osso e Ossos , Osso Cortical , Ácido 4-Acetamido-4'-isotiocianatostilbeno-2,2'-dissulfônico/análogos & derivados , Osso e Ossos/diagnóstico por imagem , Simulação por Computador , Osso Cortical/diagnóstico por imagem , Humanos , Porosidade , Ultrassonografia , Adulto Jovem
12.
Medicine (Baltimore) ; 101(47): e31555, 2022 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-36451416

RESUMO

BACKGROUND: A choristoma is defined as a growth of histologically normal tissue in an abnormal location. Epibulbar osseous choristoma is the rarest type among all ocular choristoma with less than 100 cases reported. Here, we report a case of epibulbar osseous choristoma combined with dermolipoma and a literature review. METHODS: A 15-year-old female patient presented with an accidentally found subconjunctival mass in her left eye. Slit lamp examination revealed a 10 × 10 mm elevated, sigmoid-shaped mass in the supratemporal quadrant of the bulbar conjunctiva. We performed a debulking excisional biopsy of the mass. RESULTS: The pathology confirmed osseous tissue surrounded by mature adipose tissue. At 1 week after the operation, the wound was clear and the patient was satisfied with the treatment. A systematic literature review of 14 previously published cases taken from PubMed dating back to 1987 along with ours was undertaken. The average age at presentation was 11.6 years and there was a female preponderance with 10 cases being female and the other 5 cases being male. Supratemporal conjunctiva was the most common site of presentation. There was no systemic disease associated with any of the cases. Since it is a benign tumor, it can be managed by observation, but if necessary, it can be treated by surgical removal. CONCLUSION: In pediatric subconjunctival mass, particularly located in supratemporal quadrant of bulbar conjunctiva, osseous choristoma should be considered in the differential diagnosis. Pre-operative CT scans will helpful to not also reduce complication with surgical excision but also helpful in prediction of diagnosis and prognosis.


Assuntos
Calcinose , Coristoma , Feminino , Humanos , Criança , Masculino , Adolescente , Coristoma/diagnóstico , Coristoma/cirurgia , Osso e Ossos , Microscopia com Lâmpada de Fenda , Túnica Conjuntiva
13.
Zhonghua Bing Li Xue Za Zhi ; 51(11): 1147-1151, 2022 Nov 08.
Artigo em Chinês | MEDLINE | ID: mdl-36323545

RESUMO

Objective: To investigate the clinicopathological features, clinical manifestations and different diagnosis of patients with complicated lymphatic anomaly. Methods: The clinical and pathologic data of four patients with complicated lymphatic anomaly diagnosed and treated in Peking Union Medical College Hospital from January 2000 to December 2021 were collected and analyzed. Results: One Gorham-Stout disease case and three generalized lymphatic anomaly cases were included in this cohort. Patients' ages ranged from 7 to 32 years. There were three males and one female. The positions of biopsy included three bone biopsy and one bronchus biopsy. Microscopically, all cases showed diffuse enlarged lymphatic channels. At the same time, osteogenesis was obvious in Gorham-Stout disease case. Radiologically, cortical loss was seen in Gorham-Stout disease, and lytic bone confined to the medullary cavity presented in generalized lymphatic anomaly. The three generalized lymphatic anomaly cases also had coagulopathy, and two had effusion. Conclusions: The histologic feature of complicated lymphatic anomaly was diffuse lymphatic malformation, and the diagnosis depends on clinical and pathologic information. The treatment and prognosis of these diseases are different, and therefore it is necessary to understand their clinical and pathologic features and make the correct diagnosis.


Assuntos
Anormalidades Linfáticas , Osteólise Essencial , Masculino , Humanos , Feminino , Criança , Adolescente , Adulto Jovem , Adulto , Osteólise Essencial/complicações , Osteólise Essencial/diagnóstico , Osteólise Essencial/patologia , Anormalidades Linfáticas/diagnóstico por imagem , Anormalidades Linfáticas/cirurgia , Osso e Ossos/patologia , Diagnóstico Diferencial , Prognóstico
14.
Medicine (Baltimore) ; 101(43): e28397, 2022 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-36316843

RESUMO

BACKGROUND: Cervi parvum cornu is a dried section of the young horns of Cervus nippon Temminck, Cervus elaphus Linnaeus, or Cervus canadensis Erxleben. It is a representative yang-tonifying medicine that warms the viscera and bowels, activates the overall physiological function, and has effects such as tonifying kidney yang, replenishing essence and blood, and strengthening muscles and bones. OBJECTIVE: This clinical study is aimed to evaluate the effectiveness of deer antler extract on child growth. METHODS: This clinical trial is designed to be conducted on 100 children aged 3 to 12 years for 12 weeks (Trial registration code: KCT0007386). We will evaluate changes in height, height percentile, standard deviation score of height, weight, body mass index, waist circumference, hip circumference, bone age, predicted adult height estimated by bone age, human growth hormone level, insulin-like growth factor-1 (IGF-1) level, IGF-binding protein-3 (IGFBP-3) level, IGF-1/IGFBP-3 ratio, and estradiol level. Additionally, we also will evaluate the adverse events during the study.


Assuntos
Chifres de Veado , Desenvolvimento Infantil , Animais , Criança , Humanos , Osso e Ossos , Cervos , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina , Fator de Crescimento Insulin-Like I , Pré-Escolar , Método Duplo-Cego
16.
Arch Endocrinol Metab ; 66(5): 604-610, 2022 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-36382749

RESUMO

The 2022 International Task Force guidelines for chronic hypoparathyroidism will be published within several months in the Journal of Bone and Mineral Research. These guidelines update the original guidelines published in 2016, and include new information from literature published since then. Chronic postsurgical hypoparathyroidism is now defined as lasting for at least 12 months after surgery, rather than 6 months. Chronic postsurgical hypoparathyroidism may be predicted by serum PTH <10 pg/mL in the first 12-24 hours after surgery. The most common symptoms and complications of chronic hypoparathyroidism based on the literature are summarized in detail. How to monitor and manage patients with hypoparathyroidism is described in detail where recommendations can be given. These guidelines are intended to frame the diagnosis and care of patients with chronic hypoparathyroidism for at least the next five years.


Assuntos
Hipocalcemia , Hipoparatireoidismo , Humanos , Cálcio , Hipoparatireoidismo/diagnóstico , Hipoparatireoidismo/etiologia , Hipoparatireoidismo/terapia , Osso e Ossos , Hormônio Paratireóideo
17.
Arch Endocrinol Metab ; 66(5): 611-620, 2022 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-36382750

RESUMO

Energy metabolism is a point of integration among the various organs and tissues of the human body, not only in terms of consumption of energy substrates but also because it concentrates a wide interconnected network controlled by endocrine factors. Thus, not only do tissues consume substrates, but they also participate in modulating energy metabolism. Soft mesenchymal tissues, in particular, play a key role in this process. The recognition that high energy consumption is involved in bone remodeling has been accompanied by evidence showing that osteoblasts and osteocytes produce factors that influence, for example, insulin sensitivity and appetite. Additionally, there are significant interactions between muscle, adipose, and bone tissues to control mutual tissue trophism. Not by chance, trophic and functional changes in these tissues go hand in hand from the beginning of an individual's development until aging. Likewise, metabolic and nutritional diseases deeply affect the musculoskeletal system and adipose tissue. The present narrative review highlights the importance of the interaction of the mesenchymal tissues for bone development and maintenance and the impact on bone from diseases marked by functional and trophic disorders of adipose and muscle tissues.


Assuntos
Osso e Ossos , Resistência à Insulina , Humanos , Osso e Ossos/metabolismo , Tecido Adiposo/metabolismo , Remodelação Óssea , Músculos/metabolismo , Metabolismo Energético
18.
Arch Endocrinol Metab ; 66(5): 633-641, 2022 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-36382752

RESUMO

Globally, one in 11 adults has diabetes mellitus of which 90% have type 2 diabetes. The numbers for osteoporosis are no less staggering: 1 in 3 women has a fracture after menopause, and the same is true for 1 in 5 men after the age of 50 years. Aging is associated with several physiological changes that cause insulin resistance and impaired insulin secretion, which in turn lead to hyperglycemia. The negative balance between bone resorption and formation is a natural process that appears after the fourth decade of life and lasts for the following decades, eroding the bone structure and increasing the risk of fractures. Not incidentally, it has been acknowledged that diabetes mellitus, regardless of whether type 1 or 2, is associated with an increased risk of fracture. The nuances that differentiate bone damage in the two main forms of diabetes are part of the intrinsic heterogeneity of diabetes, which is enhanced when associated with a condition as complex as osteoporosis. This narrative review addresses the main parameters related to the increased risk of fractures in individuals with diabetes, and the mutual factors affecting the treatment of diabetes mellitus and osteoporosis.


Assuntos
Diabetes Mellitus Tipo 2 , Fraturas Ósseas , Osteoporose , Masculino , Adulto , Feminino , Humanos , Pessoa de Meia-Idade , Diabetes Mellitus Tipo 2/complicações , Densidade Óssea/fisiologia , Osteoporose/complicações , Osso e Ossos , Fraturas Ósseas/etiologia , Fatores de Risco
19.
Arch Endocrinol Metab ; 66(5): 756-764, 2022 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-36382765

RESUMO

Celiac disease (CD) is an autoimmune disorder characterized by small intestinal inflammation triggered by gluten ingestion in genetically-predisposed individuals. A frequent extra-intestinal manifestation of CD is metabolic bone disease which contributes to an increased risk of fracture. The mechanisms underlying bone disease in CD remain incompletely understood, but multiple processes have been proposed including (1) malabsorption of calcium and vitamin D leading to secondary hyperparathyroidism and increased skeletal resorption, (2) pro-inflammatory cytokines altering the osteoprotegerin and receptor activator of nuclear kappa-B ligand ratio favoring osteoclastogenesis, (3) hypogonadism, and (4) low weight and malnutrition. Most studies show reduced bone mineral density in patients with CD. Bone microarchitecture is also deteriorated leading to reduced whole bone stiffness. Many, but not all investigations, have shown an increased risk of fracture associated with CD. The main stay of therapy for CD is maintaining a gluten-free diet. Improvement in bone mineral density with adherence to a gluten-free diet has been well-established. Bone mineral density remains lower, however, compared to controls and increased fracture risk can persist. There is no consensus on the timing of dual-energy x-ray absorptiometry for bone mineral density assessment in patients with CD. Routine screening for CD in patients with osteoporosis is not recommended. Little data are available on the use or efficacy of prescription osteoporosis therapeutics in patients with CD. Studies are needed to develop standardized guidelines for screening and treatment of metabolic bone disease in patients with CD to identify those who may need early intervention with prescription osteoporosis therapy.


Assuntos
Doenças Ósseas Metabólicas , Doença Celíaca , Fraturas Ósseas , Osteoporose , Humanos , Doença Celíaca/complicações , Dieta Livre de Glúten , Osso e Ossos/metabolismo , Densidade Óssea , Osteoporose/complicações , Doenças Ósseas Metabólicas/etiologia , Fraturas Ósseas/etiologia
20.
Arch Endocrinol Metab ; 66(5): 765-773, 2022 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-36382766

RESUMO

Stress fractures (SF) represent 10%-20% of all injuries in sport medicine. An SF occurs when abnormal and repetitive loading is applied on normal bone: The body cannot adapt quickly enough, leading to microdamage and fracture. The etiology is multifactorial with numerous risk factors involved. Diagnosis of SF can be achieved by identifying intrinsic and extrinsic factors, obtaining a good history, performing a physical exam, and ordering laboratory and imaging studies (magnetic resonance imaging is the current gold standard). Relative energy deficiency in sport (RED-S) is a known risk factor. In addition, for women, it is very important know the menstrual status to identify long periods of amenorrhea in the past and the present. Early detection is important to improve the chance of symptom resolution with conservative treatment. Common presentation involves complaints of localized pain, with or without swelling, and tenderness on palpation of bony structures that begins earlier in training and progressively worsens with activity over a 2- to 3-week period. Appropriate classification of SF based on type, location, grading, and low or high risk is critical in guiding treatment strategies and influencing the time to return to sport. Stress injuries at low-risk sites are typically managed conservatively. Studies have suggested that calcium and vitamin D supplementation might be helpful. Moreover, other treatment regimens are not well established. Understanding better the pathophysiology of SFs and the potential utility of current and future bone-active therapeutics may well yield approaches that could treat SFs more effectively.


Assuntos
Fraturas de Estresse , Humanos , Feminino , Fraturas de Estresse/diagnóstico , Fraturas de Estresse/etiologia , Fraturas de Estresse/terapia , Fatores de Risco , Osso e Ossos , Cálcio na Dieta , Imageamento por Ressonância Magnética/efeitos adversos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...