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1.
Food Funct ; 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38767501

RESUMO

Scope: fructose consumption from added sugars correlates with the epidemic rise in MetS and CVD. Maternal fructose intake has been described to program metabolic diseases in progeny. However, consumption of fructose-containing beverages is allowed during gestation. Cholesterol is also a well-known risk factor for CVD. Therefore, it is essential to study Western diets which combine fructose and cholesterol and how maternal fructose can influence the response of progeny to these diets. Methods and results: a high-cholesterol (2%) diet combined with liquid fructose (10%), as a model of an unhealthy Western diet, was administered to descendants from control and fructose-fed mothers. Gene (mRNA and protein) expression and plasma, fecal and tissue parameters of cholesterol metabolism were measured. Interestingly, progeny from fructose-fed dams consumed less liquid fructose and cholesterol-rich chow than males from control mothers. Moreover, descendants of fructose-fed mothers fed a Western diet showed an increased cholesterol elimination through bile and feces than males from control mothers. Despite these mitigating circumstances to develop a proatherogenic profile, the same degree of hypercholesterolemia and severity of steatosis were observed in all descendants fed a Western diet, independently of maternal intake. An increased intestinal absorption of cholesterol, synthesis, esterification, and assembly into lipoprotein found in males from fructose-fed dams consuming a Western diet could be the cause. Moreover, an augmented GLP2 signalling seen in these animals would explain this enhanced lipid absorption. Conclusions: maternal fructose intake, through a fetal programming, makes a Western diet considerably more harmful in their descendants than in the offspring from control mothers.

2.
Sci Rep ; 13(1): 2134, 2023 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-36747043

RESUMO

Exerting a constant load would likely improve orthosis effectiveness in treating knee lateral deviations during childhood and early adolescence. Shape memory alloys are potential candidates for such applications due to their so called pseudoelastic effect. The present study aims to quantitatively define the applicable mechanical loads, in order to reduce treatment duration while avoiding tissular damage and patient discomfort. This is essential for performing a more efficient design of correction devices. We use a patient-specific finite elements model of a pediatric knee to determine safe loading levels. The achievable correction rates are estimated using a stochastic three-dimensional growth model. Results are compared against those obtained for a mechanical stimulus decreasing in proportion to the achieved correction, emulating the behavior of conventional orthoses. A constant flexor moment of 1.1 Nm is estimated to change femorotibial angle at a rate of (7.4 ± 4.6) deg/year (mean ± std). This rate is similar to the achieved by more invasive growth modulation methods, and represents an improvement in the order of 25% in the necessary time for reducing deformities of (10 ± 5) deg by half, as compared with conventional orthoses.


Assuntos
Articulação do Joelho , Ligas de Memória da Forma , Humanos , Criança , Joelho , Aparelhos Ortopédicos , Braquetes , Fenômenos Biomecânicos
3.
J Mech Behav Biomed Mater ; 126: 104946, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34876369

RESUMO

Long bones geometry changes in response to longitudinal growth in the epiphyseal plates and hydroxyapatite apposition in the periosteum. Due to its relevance for growth modulation and orthotics performance, researchers have extensively modeled these phenomena, using the finite elements method for it almost since the introduction of modern computers. This is a rather complex task that, besides the inherent difficulty of solving the models equations, requires considering a moving boundary. Here, the development of a new computational tool for its resolution is described. A generalized formulation of these problems is established based on the most common approaches taken in the literature and a novel finite elements algorithm is proposed for its resolution. The later allows a significant reduction of the spatial discretization requirements, the computational cost and the numerical errors associated with more classical approaches. The potentiality of the method is demonstrated by its application to three cases of practical interest, namely, hemiepiphysiodesis treatment, growth in the distal femur and bone remodeling around hip prosthesis. Eight relevant cases of study and an open source implementation of the proposed algorithm are also provided as supplementary material.


Assuntos
Artroplastia de Quadril , Prótese de Quadril , Algoritmos , Desenvolvimento Ósseo , Simulação por Computador , Fêmur , Análise de Elementos Finitos
4.
J Biomech ; 109: 109905, 2020 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-32807336

RESUMO

A mechanobiological model of bone growth aimed for the design of medical devices for the treatment of limb deformities during childhood and adolescence was developed. Dimensional analysis was introduced as a tool for the systematic evaluation of the influence attributed to different factors that might modify the bone growth process. Simplifications were proposed, allowing the reduction of bone growth relevant parameters to four non-dimensional numbers, representing the chondrocyte sensitivity to stress, the epiphyseal plate geometry, the bone rigidity and the time. Benchmark situations considered for model validation were bone growth under normal conditions and an epiphyseal stapling treatment. A finite elements approach was used to analyze bone growth in the distal portion of the femur. Results are shown to be consistent with corresponding clinical data published in the literature, which indicates the potential of the here proposed method for the design of specific devices and treatments.


Assuntos
Desenvolvimento Ósseo , Lâmina de Crescimento , Adolescente , Biofísica , Fêmur , Fixação Interna de Fraturas , Humanos
5.
J Pediatr Orthop B ; 8(2): 132-5, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10218178

RESUMO

Giant cell tumor of the bone is infrequent in the phalanges of the toes and is extremely rare in children. A case of giant cell tumor of the proximal phalanx of the big toe on the left foot in a 12-year-old boy is reported. The tumor was treated by partial resection of the phalanx and repair of the osseous defect with an autologous iliac crest graft. A literature review showed few cases of giant cell tumor at this site.


Assuntos
Neoplasias Ósseas/diagnóstico , Tumor de Células Gigantes do Osso/diagnóstico , Hallux , Biópsia , Neoplasias Ósseas/classificação , Neoplasias Ósseas/cirurgia , Criança , Diagnóstico Diferencial , Tumor de Células Gigantes do Osso/classificação , Tumor de Células Gigantes do Osso/cirurgia , Humanos , Ílio/transplante , Masculino
6.
Clin Orthop Relat Res ; (350): 56-61, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-9602800

RESUMO

Fractures of the proximal femur are, more than ever, an important challenge in the field of traumatology. The Gamma nail, a combination of advantages of the sliding screw with the intramedullary nail, represents an efficient technique in the management of these fractures. A series of 224 fractures of the proximal femur in which this nail was used is reported. The average age of the patients was 79.2 years. The mean healing time was 68.2 days in 99.4% of the cases. The incidence of perioperative complications was 10.3% showing that, in most of the cases, the complications occurred because of poor technique. Postoperative complications occurred with an incidence of 14.1%. Seven cases of migration of a proximal screw, six shaft fractures, and one broken nail were the most important complications. The device allowed for early mobilization and full weightbearing of the affected hip regardless of the type of fracture. With adequate surgical technique and experience, the advantages of the Gamma nail increases as the complication rate diminishes.


Assuntos
Pinos Ortopédicos , Fraturas do Colo Femoral/cirurgia , Fixação Intramedular de Fraturas/instrumentação , Fraturas do Quadril/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Parafusos Ósseos , Feminino , Fraturas do Colo Femoral/diagnóstico por imagem , Fraturas do Quadril/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Radiografia , Resultado do Tratamento
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