Document Type

Thesis

Date of Award

5-31-1988

Degree Name

Master of Science in Biomedical Engineering - (M.S.)

Department

Biomedical Engineering Committee

First Advisor

Peter Engler

Second Advisor

L. Horn

Third Advisor

David S. Kristol

Abstract

This is a new method for histoarchitectural and volumetric analyses of cell compartments of microvasculature with the use of a unique combination of computerized 3-D reconstruction and HVEM thick serial cross sections. The technology is potentially a reliable, simple, accurate and fast method. Pioneering work in this area was started by Todd et al. (Circ Res Vol :53 p 319 ;1983) basically using light microscopy, but supported by conventional ultrathin transmission electron microscopy. These techniques are important in that they promise to resolve controversies in terms of evaluating the occurance of hyperplasia and hypertrophy in small resistance vessels in various forms of hypertension.

Small blood vessels were sampled, dissected, fixed, embedded, sectioned and stained by a standardized procedure to obtain the HVEM electron micrographs. The electron micrographs were enlarged, photomontaged, digitized,and the coordinates transferred to a PC computer for storage and image processing.

An attempt is made to calculate the average volumes of vascular smooth muscles (VSM), endothelium (END), internal elastic lamina (IEL), individual cell volumes and nuclear-to-cell volume ratios in normotensive control and hypertensive blood vessels respectively. The calculations for the hypertensive sample vessel give evidence of increased wall thickness, VSM and END hypertrophy, END hyperplasia, and a substantial increase in the IEL thickness.

Morphologically the 3-D reconstructed image of the hypertensive blood vessel exhibits helical orientation of the VSM with a pitch of 5 to 35 degrees; the END is mostly oriented parallel to vessel axis. The entire VSM cell is helically wrapped around the vessel wall. The END nuclei have irregular outline; these features are more pronounced in the hypertensive vessel than in the normotensive control vessel. The IEL is densely corrugated in the hypertensive vessel.

A comparative statistical study between the sequential montaged method and that of a single 1000x HVEM of the entire cross section, photographically enlarged, shows that the two methods give numerical values within 95% confidence interval i.e. with differences less than 5%.

The contents of this investigation taken as a whole, constitute a unified presentation of the essential aspects of the method used in this microvascular study.

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.