Contribution of plasma protease inhibitors to the inactivation of kallikrein in plasma.

Although Cl-inhibitor (Cl-INH) and alpha(2)-macroglobulin (alpha(2)M) have been reported as the major inhibitors of plasma kallikrein in normal plasma, there is little quantitative support for this conclusion. Thus, we studied the inactivation of purified kallikrein in normal plasma, as well as in plasma congenitally deficient in Cl-INH, or artificially depleted of alpha(2)M by chemical modification of the inhibitor with methylamine. Under pseudo-first-order conditions, the inactivation rate constant of kallikrein in normal plasma was 0.

Protection of human plasma kallikrein from inactivation by C1 inhibitor and other protease inhibitors. The role of high molecular weight kininogen.

High Mr kininogen increases the activation rate of prekallikrein by activated factor XII on a surface. The resulting serine protease, plasma kallikrein, Mr 88 000, is inhibited in plasma by C1 inhibitor, Mr 105 000. Since prekallikrein circulates in plasma with high Mr kininogen as a complex and a kallikrein-high Mr kininogen complex can be formed in purified systems, we studied whether the inhibition of kallikrein by C1 inhibitor was influenced by high Mr kininogen.

Value of examining buffy coats for intragranulocytic micro-organisms in patients with fever.

To determine the significance of the presence of intragranulocytic micro-organisms in the blood buffy coat in patients with suspected infection, buffy coat examination and blood cultures were simultaneously performed in 455 consecutive patients with fever. There was no general correlation between the finding of intragranulocytic micro-organisms in the buffy coat and positive blood cultures. Patients with persistent bacteraemia and sterile blood cultures were, however, shown to have persistently positive buffy coat findings on repeated examination.

[Study of leukocyte enriched blood smears in suspected bacteremia].

In 132 consecutive patients with suspected bacteremic infectious diseases, Gram staining of the buffy coat of blood taken from the ear lobe was performed simultaneously with blood cultures. Out of 132 patients, 7 exhibited intraleukocytic microorganisms among 22 with concomitant positive hemocultures and 21 with concomitant sterile hemocultures. Among this latter group of patients, 8 were severely ill subjects with indwelling intravenous catheters and undergoing treatment with broad spectum antibiotics, while 4 were found to have intraleukocytic yeast forms.