Coronary artery stenosis controlled by distal perfusion pressure: description of the servo-system and time-dependent changes in regional myocardial blood flow.

An animal model for the induction of coronary artery stenosis is described. In this model the degree of stenosis, as induced with commercially available hydraulic occluders, can be easily controlled by keeping constant the mean perfusion pressure (pcor) distal to the site of stenosis. This pcor is the input signal for a servo-system feeding a motor-pump, which determines the degree of inflation of the cuff around the left anterior interventricular coronary artery (LAICA).

Use of telescopic imaging in intravital microscopy: a simple solution for conventional microscopes.

Conventional microscopes can be adapted for telescopic imaging by using a projection eyepiece which focuses the image formed by a standard microscope objective at such a large distance that light emanating from points on the object leaves the eyepiece as parallel bundles. A telescopic transfer lens forms the final image in its focal plane independent of the distance between the eyepiece and the transfer lens. In the system reported in this paper, the distance between the eyepiece and transfer lens can be varied from 0 to 280 mm without appreciable vignetting or image degradation for imaging on 35 mm film or smaller formats.