RESUMO
Microindentation of fresh biological tissues is necessary for the creation of 3D biomimetic models that accurately represent the native extracellular matrix microenvironment. However, tissue must first be precisely sectioned into slices. Challenges exist in the preparation of fresh tissue slices, as they can tear easily and must be processed rapidly in order to mitigate tissue degradation. In this study, we propose an optimised mounting condition for microindentation and demonstrate that embedding tissue in a mixture of 2.5% agarose and 1.5% gelatin is the most favourable method of tissue slice mounting for microindentation. This protocol allows for rapid processing of fresh biological tissue and is applicable to a variety of tissue types.
Assuntos
Biomimética , Matriz Extracelular , Alimentos , Gelatina , Teste de HistocompatibilidadeRESUMO
BACKGROUND AND AIMS: Atherosclerotic calcification is a powerful predictor of cardiovascular disease. This study aims to determine whether circulating levels of a local/systemic calcification inhibitor or a marker of bone formation correlate with measures of coronary or extracoronary calcification. METHODS AND RESULTS: Clinical computed tomography (CT) was performed on 64 arterial disease participants undergoing carotid and lower extremity endarterectomy. Coronary artery calcium (CAC) scores and volumes were acquired from the CT scans (n = 42). CAC scores and volumes were used to derive CAC density scores. Micro-CT was performed on excised carotid (n = 36) and lower extremity (n = 31) plaques to quantify the volume and volume fraction of extracoronary calcification. Circulating levels of dephospho-uncarboxylated Matrix Gla Protein (dp-ucMGP), fetuin-A, carboxylated and uncarboxylated osteocalcin (ucOC) were quantified using commercial immunoassays. Carotid participant CAC density scores were moderately negatively correlated with plasma dp-ucMGP (rs = -0.592, P = 0.008). A weak negative association was found between CAC scores and %ucOC for all participants (rs = -0.335, P = 0.040). Another weak negative correlation was observed between fetuin-A and the volume of calcification within excised carotid specimens (rs = -0.366, P = 0.031). Despite substantial differences in coronary and extracoronary calcium measurements, the levels of circulating biomarkers did not vary significantly between carotid and lower extremity subgroups. CONCLUSION: Correlations identified between circulating biomarkers and measures of coronary and extracoronary calcium were not consistent among participant subgroups. Further research is required to determine the association between circulating biomarkers, coronary and extracoronary calcium.
Assuntos
Proteínas de Ligação ao Cálcio/sangue , Doenças das Artérias Carótidas/sangue , Doença da Artéria Coronariana/sangue , Proteínas da Matriz Extracelular/sangue , Extremidade Inferior/irrigação sanguínea , Osteocalcina/sangue , Doença Arterial Periférica/sangue , Calcificação Vascular/sangue , alfa-2-Glicoproteína-HS/análise , Idoso , Biomarcadores/sangue , Doenças das Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/cirurgia , Angiografia por Tomografia Computadorizada , Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico por imagem , Endarterectomia das Carótidas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doença Arterial Periférica/diagnóstico , Doença Arterial Periférica/cirurgia , Placa Aterosclerótica , Valor Preditivo dos Testes , Calcificação Vascular/diagnóstico por imagem , Calcificação Vascular/cirurgia , Microtomografia por Raio-X , Proteína de Matriz GlaRESUMO
BACKGROUND AND PURPOSE: The purpose of this study is to examine the ability of ex vivo derived Agatston, Volume, and Density-Volume calcium scores or calcium density measurements to differentiate between carotid plaques based on preoperative cerebrovascular symptomatology. METHODS: Thirty-eight carotid plaques were acquired from standard endarterectomy. Micro-computed tomography was performed on the ex vivo samples. Image series were downsampled to represent the resolution of clinical multidetector computed tomography. Agatston, Volume, and Density-Volume carotid calcium scores were then calculated using coronary methodologies. The fractions of low- and high-density calcification were also determined. RESULTS: The coronary calcium scores could not differentiate between carotid plaques from asymptomatic versus symptomatic patients. However, plaques from asymptomatic patients contained significantly lower fractions of low-density calcification and higher fractions of high-density calcification. CONCLUSIONS: Screening for carotid calcium density in noncontrast computed tomography could reflect plaque stability.