Effects of Tranexamic Acid, CIS-AMCHA, and 6-Aminohexanoic Acid on the Activation Rate of Plasminogen by Urokinase in the Presence of Clot

When human plasma was mixed with 50 units of urokinase (UK) and clotted with thrombin in the presence of S-2251, the hydrolysis of S-2251 in the clot was higher than that in the plasma. The presence of 10 μM of tranexamic acid resulted in decrease in the activation rate of plasminogen in the clot but not in the plasma. Further increase in its concentration resulted in marked increase in plasminogen activation in both clot and plasma. The addition of 6-aminohexanoic acid or cis-AMCHA showed changes in the rate of plasminogen activation similar to that shown in the presence of tranexamic acid. Fifty μM of tranexamic acid totally inhibited urokinase induced clot lysis, while 1 mM of cis-AMCHA and 6-aminohexanoic acid totally inhibited clot lysis. The presence of 1 mM of thesewaminoacids remarkably increased the activation of plasminogen by UK, but no clot lysis was observed. Hydrolysis of 5-2251 was higher in the presence of tranexamic acid than in its absence or clot formation without tranexamic acid. Tranexamic acid seems to be more effective in enhancement of activation of plasminogen by UK than clot formation. Plasmin formed by UK was coexistent with α2PI. The presence of tranexamic acid or clot formation resulted in smaller extent of interaction of plasmin with α2PI, thus saving the exhaustion of α2PI and preventing instant inactivation of plasmin by α2PI.

The measurement of serum proteins with rapid turnover for early diagnosis of fatal hepatitis

An attempt was made to find reliable indices for the early recognition of fatal cases of acute viral hepatitis, using the values of serum proteins with rapid turnover. Prealbumin and alpha2-HS-glycoprotein were measured in the sera of 44 cases by immunodiffusion method before the appearance of hepatic coma and/or gastrointestinal bleeding. The difference of the mean values of prealbumin between fatal and surviving cases of subacute form of fulminant hepatitis was not statistically significant. In contrast to this, there was statistically significant difference between both groups in the mean values of alpha2-HS-glycoprotein (p less than 0.05). The present results indicate the possibility of differentiating fatal cases from surviving ones at an early stage, using the reduction of alpha2-HS-glycoprotein by a simple and reproducible immunodiffusion method.

Inhibition of the classical and alternative pathways by amino acids and their derivatives

Effects of various aminoacids and their derivatives on the classical pathway and alternative pathway of the complement were studied. Leupeptin, acetyl-leucyl-leucyl-arginal, inhibited CH50 and Cl-esterase, but did not inhibit the alternative pathway. When aminoacids of carbon chains of the order of seven were used, arginine and lysine had stronger effects than trans-aminomethyl cyclohexane carboxylic acid (t-AMCHA), cis-aminomethyl cyclohexane carboxylic acid (cis-AMCHA) and epsilon aminocaproic acid (EACA). SH-compounds, cysteine, homocysteine and glutathione, had the strongest inhibitory effects among these aminoacids on both classical and alternative pathways. When effects on Cl esterase were compared, arginine, lysine, t-AMCHA, cis-AMCHA and EACA had weak inhibition while SH-compounds showed strong inhibition. Poly-L-lysine, which had extremely strong inhibition of CH50, had no inhibition of Cl esterase. The inhibitory effects of antifibrinolytic agents, EACA and t-AMCHA, were weak but when effects on early parts of the classical pathway, C(1,4,2)H50 were tested, some inhibitory activities were recognized. Thus inhibitory effects of these agents were due to their activities on the early parts of the classical pathway.

The effects of metal ions on esterase activities of urokinase

The esterase activity of highly purified human urokinase on Nalpha-acetylglycl-L-lysine methyl ester is strongly inhibited by 1 X 10(-5) to 1 X 10(-2)M Cu++, Hg++, Ni++, Co++, Fe+++, and Mn++ solutions, whereas Na+, K+, Ca++, and Mg++ are weakly effective. This inhibition is parallel with the inhibition of activation of plasminogenby urokinase. There is no simple linear relation between inhibiton and concentration. Addition of ethylenediaminetetraacetate or electrodialysis fully reactivates the inhibited enzyme. These results are discussed in relation to similar effects of ions on trypsin.

Color reaction of cholesterol with trichloracetic acid and antimony trichloride. On the reaction mechanism

The color reaction of cholesterol with trichloracetic acid and antimony trichloride was examined to elucidate its reaction mechanism. 3,5-Cholestadiene, 3,3'bis(3,5-cholestadiene), 3,3'bis(2,4-cholestadiene), and cholesteryl trichloroacetate were isolated as the reaction products from the colored reaction mixture of cholesterol, and the first three compounds were found to be responsible for the coloration. It was assumed that cholesterol was dehydrated to 3,5-cholestadiene and 2,4-cholestadiene, which were dimerized to 3,3'-bis(3,5-cholestadiene) and 3,3'-bis(2,4-cholestadiene), respectively, and 3,3'-bis(2,4-cholestadiene) was in part converted to 3,3'-bis(3,5-cholestadiene) in trichloroacetic acid and antimony trichloride. The free radicals were detected in the colored solutions of choelsterol, 3,5-cholestadiene, 3,3'-bis(3,5-cholestadiene), and 3,3'-bis(2,4-cholestadiene), and inferred to be the radical cations of the steroids. The radical cation was postulated to be responsible with respect to the mechanism of the coloration. The relationship between the color reagent and the formation of dimeric steroids was described.

[Trypsin inhibitors in human urine (author's transl)]

By using ammonium sulfate, Arg-Sepharose and gel filtration, an urinary trypsin inhibitor (UTI) with molecular weight of 67,000 (UTI7) was isolated from normal human urine. The yield of UTI7 was about 3,200 U per liter of urine. When urine was acidified, an uropepsin-like substance was activated which caused molecular weight change of UTI7. New UTIs had molecular weight of 45,000 and 22,000 (UTI4-5 and UTI-2-2), respectively. These inhibitors showed a strong effect on trypsin, alpha--chymotrypsin and lesser extent on plasmin and elastase, but had no effect on esterolytic activity on thrombin and the first components of complement Cls an Clr.

Lymphokine-like factors produced by human lymphoid cell lines with B or T cell surface markers

In the present series of experiments we examined the ability of eight continuous cell lines derived from human lymphocytes to release lymphokines into their culture media. We have demonstrated that all could produce a macrophage migration inhibitory factor and a neutrophil chemotactic factor. This ability was independent of the B or T cell origin of the cell lines. As a further extension of previous reports, we report that the migration inhibitory effect does not seem to be due to cytotoxic effects as judged by trypan blue exclusion studies, and more important by the demonstration that the inhibition is reversible. The demonstration that neutrophil chemotactic activity is removable by treatment with a previously described and characterized anti-lymphokine antiserum suggests that this factor may be chemically similar to some of the lymphokines (migration inhibitory factor or chemotactic factor for macrophages) produced by antigen-activated guinea pig lymphocyte cultures. The failure to effect similar removal or inactivation of the macrophage migration inhibitory factor may simply reflect greater interspecies heterogeneity in this factor, or more interestingly, that this does not correspond to "classic" MIF. These results extend previous observations by defining further the capacity of lymphoid cell lines in continuous culture to produce mediators and by characterizing their relationship to conventional lymphokines produced by antigen or mitogen-activated lymphocytes.

Membrane characteristics of established human T- and B-cell lines. Cross-reactivity of human T-antigenic determinants with peripheral lymphocytes of non-human primates and the presence of MLC antigens on cultured T-cell lines

Human T-cell lines (MOLT-4 and SOMMER-T) were injected into rabbits and monkeys (stumptail and squirrel monkeys). Rabbit anti-MOLT serum was absorbed with human liver and cultured B cells. Absorbed anti-MOLT serum was cytotoxic to lymphocytes of baboons and stumptail monkeys. Rabbit anti-MOLT and SOMMER-T sera after absorption with liver and B cell showed florescent ring formation in baboon and stumptail lymphocytes by using immunoflurescence techniques. On the other hand, antisera against MOLT and SOMMER-T cells in stumptail and squirrel monkeys were not only cytotoxic to MOLT and SOMMER-T cells, but also to other T-cell lines, CCRF-CEM and CCRF-HSB-2 cells. Cultured B-cell lines stimulated allogeneic and xenogeneic (rabbit and monkeys) lymphocytes far better than cultured T-cells lines did. T-cell lines, CCRF-HSB-2 and SOMMER-T (number 8402), gave small but significant stimulation to allogenic lymphocytes especially in the presence of foetal calf serum. MOLT-4B failed to stimulatie allogeneic lymphocytes. When lymphocytes of non-human primates and rabbit were cultured with human B- and T-cell lines in the presence of foetal calf serum, CCRF-HSB-2 and SOMMER-T cells stimulated xenogeneic lymphocytes of rabbit, squirrel monkey and stumptail monkey. MOLT-4 cells stimulated lymphocytes of baboon to some extent. These results indicate that although cultured B-cell lines had more mixed lyphocyte reaction (MLR) stimulating structure than T-cell lines, the latter still maintained some stimulating structure on the membrances.