Biomedical subjects

Patricia L Moreira

Publications and source records attributed to Patricia L Moreira.

3 recordsLinked to original sources

PubMed2005

Arterial embolization using poly-N-acetyl glucosamine gel in a rat kidney model.

Aqueous solutions of poly-N-acetyl glucosamine (p-GlcNAc) exhibit a liquid-gel transition at physiological pH and temperature. This feature inspired the authors to conduct a study to evaluate the macro- and histological changes of rat kidneys after embolization using either p-GlcNAc gel injection into the renal artery or ligation of the renal artery. The procedures were performed in 46 rats through open abdominal surgeries. Animals were sacrificed at 3 days and at 1, 3, 5, and 8 weeks postoperatively. The results of both macro-observation and histological study showed that p-GlcNAc gels were effective in causing necrosis and subsequent fibrosis in all embolized kidneys. The data indicate that p-GlcNAc gel may have promise as an effective agent for therapeutic embolization.

Acetylglucosamine↗

PubMed2004

In vitro analysis of anionic collagen scaffolds for bone repair.

Collagen has been extensively described as a beneficial material in bone tissue engineering due to its biocompatibility, biodegradability, low antigenicity, and high tensile strength. However, collagen scaffolds in their pure form have some drawbacks and improvements in the physical, chemical, and biologic properties of collagen are necessary to overcome those inadequacies. Recently, the selective hydrolysis of carboxyamides of asparagine and glutamine residues of collagen has been employed to increase the number of negative sites and enhance the piezoelectric properties of collagen. Anionic collagen scaffolds were prepared by use of a hydrolysis treatment for either 24 h [bovine pericardium (BP 24)] or 48 h (BP 48). Bovine osteoblasts were cultured on them and on native matrices to understand the cellular interactions responsible for the good osteoconductivity and biocompatibility reported with in vivo tests. Based on the data obtained on cell adhesion, alkaline phosphatase (ALP) and extracellular matrix macromolecule production, and cellular proliferation through histological analysis, we may conclude that the materials tested reveal sufficient biocompatibility level for bone repair. Further, the evidence of some connection between ALP activity and the mineralization process should be emphasized. BP 48 presented the most promising results stimulating in vitro mineralization, ALP production, and possible osteoblast differentiation.

Alkalies↗

PubMed2003

Animal models for therapeutic embolization.

Embolization techniques have been performed in different animals to accumulate basic data before a clinical trial. Choosing the right embolization model for a specific project is critical. However, there are several variables when defining the best model for embolization research such as the size of the animal to be used, the target organs, the route of introducing the embolization agent, and the feasible methods of evaluation. Commonly used research animals for endovascular embolization include rabbits, dogs, and rats. Frequently used target organs are the kidney and the liver. Most models use a transcatheter for introducing the embolus and occasionally open surgery and direct arterial injection are used. Basic methods of evaluation are straightforward, and commonly include macro observation of the embolized organs, angiogram, and histology. This article concisely reviews the available animal models and their evaluation for embolization research to help researchers to choose the appropriate model.

Aneurysm↗