36 research outputs found
Poro-mechanical analysis of a biomimetic scaffold for osteochondral defects
Osteochondral defects are focal areas of damage involving articular cartilage and sub-chondral bone. Tissue engineering scaffolds are used to improve the organism regeneration ability for this kind of injury, serving as biocompatible structures for cell viability and differentiation. Since biomechanical cues such as substrate stiffness, loading conditions and fluid permeation are fundamental for successful tissue repair, understanding how these features vary in the scaffold is of primary importance. Here we present a mathematical model based on porous media mechanics for the analysis of a tissue engineering scaffold. We consider a three-layered scaffold mimicking a complete osteochondral tissue and vary the mechanical properties of the intermediate layer over a physiological range. Our results show that the interstitial fluid pressure and the vertical component of the solid effective stress depend significantly on the stiffness and permeability of the intermediate layer under mechanical loading. By properly tuning these material properties, regimes of slow or fast temporal variations of mechanical stress can be obtained in the scaffold layer of interest
Acidentes por escorpião em uma área do Nordeste de Amaralina, Salvador, Bahia, Brasil Scorpion sting in an area of Nordeste de Amaralina, Salvador, Bahia, Brazil
Um estudo epidemiológico mediu a prevalência de pessoas que referiram acidentes por escorpião em uma amostra populacional do Areal, bairro Nordeste de Amaralina, Salvador, Bahia. Examinou-se uma amostra aleatória sistemática de 1367 indivÃduos, correspondendo a 44,4% da população da área. Oitenta e dois indivÃduos referiram haver sido picados por escorpião desde que residiam no Areal, resultando numa prevalência de 6% (IC 95% 4,7 - 7,3). A prevalência de pessoas picadas por escorpião aumentou nos grupos com maior tempo de residência no domicÃlio e com maior idade atual. Chamou atenção que 92,7% dos acidentes aconteceram dentro do domicÃlio. A incidência estimada para o perÃodo mais recente (janeiro a julho de 2000) foi de 1,15 casos/1.000 habitantes por mês. Este coeficiente compara-se ao mais elevado já referido na literatura especializada para uma área epidêmica para acidentes escorpiônicos.<br>An epidemiological study was undertaken to determine the prevalence of individuals who referred scorpion sting accidents in a population sample from Areal, a neighborhood northeast of Amaralina, Salvador City, State of Bahia, Brazil. A random, systematic sample of 1,367 individuals was taken, corresponding to 44.4% of the total population. Eighty-two residents referred scorpion sting since they were resident in Areal, giving a prevalence coefficient of 6% (95% CI 4.7 - 7.3). The prevalence of persons stung by scorpions increased according to greater time spent in the domicile and more advanced age. It was remarkable that 92.7% of the scorpions stings occurred within the home. The incidence coefficient estimated for the most recent period of time (January to July, 2000) was 1.15 cases/1,000 inhabitants per month, comparable to the highest ever reported for an epidemic area
‘Focus on feet’ – the effects of systemic lupus erythematosus: a narrative review of the literature
Background: The manifestations of systemic lupus erythematosus (SLE) vary between individuals,
from the severe and life-threatening renal and central nervous system involvement, to
the involvement of skin, musculoskeletal and vascular system, and the complications of infection
influencing the quality of life. However, as specific manifestations affecting the lower limb
are perceived as receiving little focus, the purpose of this narrative literature review is to
identify the specific factors associated with SLE that may have implications for lower limb
and foot morbidity. Method: A structured search of databases was conducted. The inclusion
was restricted to publications in the English language, those that specifically investigate the
feet as affected with SLE. No restriction on year of publication was imposed to reduce publication
bias and to capture as many publication in relation to feet. Results: Eleven papers
fulfilled the inclusion criteria. There were seven additional papers that made observations
related to the articular or vascular complications of the feet. This narrative review provides
some information on how SLE affects the lower limb and foot in relation to the musculoskeletal
and vascular systems. However, there is a lack of literature that specifically focuses on
all the manifestations of SLE and the complications associated with its
management. Discussion: There are indications that SLE affects lower limb and foot morbidity
but the scale of these problems is unclear and this is partly because of the absence of
research and the lack of a ‘gold standard’ framework for the assessment of the lower limb and
foot. In addition to clinical foot health assessment, ultrasonography may be a useful alternative
to plain film radiography or magnetic resonance imaging (MRI) in capturing the extent of
articular and extra-articular manifestations. Further, the Ankle Brachial Pressure Index
(ABPI) may be useful in identifying those with atherosclerosis and ischaemia. Conclusion:
There are indications that SLE affects lower limb and foot morbidity but the scale of these
problems and effective management of them is unclear. Therefore, further research is warranted
in order to better understand the impact of SLE on the foot and lower limb and its
impact on quality of lif