Biomedical subjects

Craig Daly

Publications and source records attributed to Craig Daly.

3 recordsLinked to original sources

PubMed2005

Influence of elastin on rat small artery mechanical properties.

We have previously developed a method for estimating elastin content and organization in resistance arteries, where it is a minor component. The aim of the present study was to validate the method against a quantitative assay and to determine the relative importance of elastin content and organization for intrinsic elasticity of small arteries. Mesenteric third order branches (from 10-day-old, 1- and 6-month-old rats) and middle cerebral arteries (from 6-month-old rats) were pressurized. beta-Values were calculated from stress-strain relationships and used as indicators of intrinsic stiffness. The same pressure-fixed arteries were used to estimate elastin content and organization in the internal elastic lamina with confocal microscopy. Collagen and elastin contents were determined by Picrosirius Red staining and radioimmunoassay for desmosine, respectively. Confocal and desmosine assays gave similar results: no difference in elastin content of mesenteric vessels from 1- and 6-month-old rats, and a significant reduction in cerebral compared to mesenteric arteries. For all parameters (elastin and collagen content, fenestrae area and internal elastic lamina thickness) the best correlation was found between beta-values and fenestrae size. These data suggest that in small arteries: (1) confocal microscopy can be used as a method for the simultaneous study of changes in elastin content and organization; and (2) elastin organization might be a key determinant of intrinsic elastic properties.

Aging↗

PubMed2003

Visualization of live endothelial cells ex vivo and in vitro.

The present study describes quick and effective methods that allow visualization of the vascular endothelium in living networks within dissected pieces of human tissue or in primary cultures containing heterogeneous cell populations. Fresh human uterine and subcutaneous gluteal fat tissues were directly labelled using fluorescently conjugated Ulex Europaeus Agglutinin I (UEA-1) to visualize the three-dimensional nature of the vascular network. Using conventional epi-illuminescence microscopy, the convoluted architecture demonstrating branch points within capillaries, between capillaries and larger vessels, were clearly observed in uterine and subcutaneous gluteal fat samples. In adult endometrial tissue where angiogenesis occurs on a monthly basis, complex anastamosis of vessels and tenuous structures were clearly seen. Three-dimensional rendered surface models formed by examination of confocal z-stacks demonstrated the existence of the lumen within microvessels. Tissue prelabelled with UEA-1 was used to assist and verify the presence of endothelial cells in culture, during and after the isolation procedure. Additionally, UEA-1 was added to a uterine fibroblast-microvascular-endothelial cell coculture model to allow daily vital observations of changes in the phenotype of the endothelium. The simple techniques described here demonstrate the ease with which fluorescently labelled UEA-1 can be used as a vital marker of endothelial cells either in tissue or in a tube-forming human uterine microvascular culture model.

Buttocks↗

PubMedDate not supplied

Confocal microscopic image sequence compression using vector quantization and three-dimensional pyramid.

The three-dimensional (3-D) pyramid compressor project at the University of Glasgow has developed a compressor for images obtained from confocal laser scanning microscopy (CLSM) device. The proposed method using a combination of image pyramid coder and vector quantization techniques has good performance at compressing confocal volume image data. An experiment was conducted on several kinds of CLSM data using the presented compressor compared with other well-known volume data compressors, such as MPEG-1. The results showed that the 3-D pyramid compressor gave a higher subjective and objective image quality of reconstructed images at the same compression ratio, and presented more acceptable results when applying image processing filters on reconstructed images.

Animals↗