Control of tissue environment during vital microscopy of the microcirculation in the m. tenuissimus in cat

Abstract

The physiological preservation of the tenuissimus muscle preparation in cat during vital microscopy of the microcirculation is assessed, comparing the originally described technique with a modified approach. Differences in the compared techniques include modes of dissection and transillumination, room-air exposure and moisturizing procedures. The original technique involves extensive dissection, inadequate temperature control and irrigation in open air. The modified technique involves less surgery due to a new illumination system, controlled heating and a Mylar foil cover on the preparation to minimize room-air influences. Temperature measurements and analyses of energy metabolism (ATP, CP, glucose, G6-P and lactate) are used as objective criteria of tissue normalcy. The microcirculation and metabolism are evaluated during anesthesia (alpha-chloralose) at rest as well as in hemorrhagic shock. In the resting state, muscle temperature drops to 28 degrees C with the irrigation technique, whereas the Mylar technique keeps the temperature at 34--35 degrees C. Neither technique causes deviations in normal metabolism. In shock, however, the temperature in the irrigated tenuissimus muscle fall 8--9 degrees C below deep muscle temperature and there is a significantly attenuated metabolic response to ischemia, while the Mylar preparation follows the changes of unexposed muscle, both in temperature and metabolism.

Passive circulating cell sorting by deformability using a microfluidic gradual filter

“…During the last few decades, several methods have been developed to probe the deformability of circulating cells. Microfiltration experiments consist of measuring the transit times of cells through micropore filters [12][13][14][15][16][17][18][19] and abnormal transit times are attributed to an alteration of leukocyte stiffness. These methods have been successful to link cell mechanical alterations with various diseases, 12,14,15 but their weakness is to only yield the average information on a cell population or the endpoint information (e.g.…”

Lethal deformation of cancer cells in the microcirculation: A potential rate regulator of hematogenous metastasis

“…The left cremaster muscle was exposed by gentle dissection, spread over a transparent silicone rubber platform and fixed at its edges with needles. The muscle was covered with a thin Mylar sheet to exclude room air (Amundson et al, 1980) and kept at 36°C by continuous superfusion with warmed saline.…”

A new design of double‐barrelled microelectrodes for intracellular pH‐measurement in vivo

“…The skin and the fascia over m. gastrocnemius were opened during observation in an operational microscope so that tissue damage and bleeding during the preparation could be minimized. The muscle surface was moistened with unbuffered Ringer's solution and then covered with a 12 pm thick mylar foil in order to prevent excessive evaporation and gasexchange (Severinghaus 1968, Amundson 1980. The animal was connected to earth with an AdAgCl-agar electrode, placed at the edge of the incision.…”