Enzymatic Determination of in vitro Lysis of Leukocytes by Tuberculin

Abstract

tures had a third property, inhibition of proteolysis. The activator described here resembles "tissue activator9' in that it is not proteolytic in the absence of serum and can be dissolved by KSCN. It also resembles activator from excised rat lung( 16) in that it is the size of microsomes. The interpretation that release of activator from cell culture is a metabolic process and not from cell breakdown seems warranted since only a small fraction of the activity found in the supernatant can he extracted from the cells.

Cytolytic Plasma Factor in Experimental Coccidioidomycosis

“…Frozen 5th-week serum samples were thawed after 6 weeks of storage. Washed packed cells were prepared from a pool of fresh heparinized blood obtained from several uninfected stock adult guinea pigs.…”

Delayed Hypersensitivity in Tuberculous Mice

“…The present studies were undertaken in an attempt to correlate the release of lysozyme by cells of the reticuloendothelial system and other circulating leucocytes with reactions of the delayed (6,4,5,16), but never in mice. Although classical delayed skin reactions are not readily observed in mice, local and generalized manifestations of delayed type sensitivity have been described (17,18,19,21,21,22).…”

“…Such extracellular enzyme activity correlates fairly well with in vitro lysis of leucocytes (6) which would make the determination of these enzymes a suitable method for measuring hypersensitivity on a cellular level.…”

Effect of Bacterial Endotoxin on Leucocytes of Tuberculin Sensitive Hosts

“…A second total leuco cyte count was then made and the "decrement" was calculated by substracting the percent change in the diluent tubes from the per cent change in the experimental tubes. As an alternate method, the tubes were centrifuged and assays for lysozyme-like enzyme were performed on 0.1 ml portions of each supernatant fluid (11). In this case, an index of cellular damage was calculated by subtracting the mean percent lysis of substrate by diluent tubes from that ob tained with experimental tubes.…”

“…Damage to peripheral blood leu cocytes was measured by electronic * cell counts or by a technique based on the release of an intracellular, lysozyme-like enzyme from injured cells (11). For each blood to be tested, duplicate experi mental and control tubes (siliconized**) were prepared, each con taining 0.4 ml of freshly collected, heparinized whole blood.…”