A specific, fluorescent activity staining procedure applied to plasma and red blood cells in congenital factor XIII deficiency

A reversed activity staining procedure for detection of an acquired antibody against factor XIII in a girl with factor XIII deficiency

A new method for detection of inhibitors against factor XIII is described. Agarose gel electrophoresis with normal platelet poor plasma as a factor XIII source included in the gel was combined with reversed activity staining. The procedure was applied to a 10-year-old girl with factor XIII deficiency where substitution therapy had failed. Plasma samples from the patient inhibited the factor XIII catalysed incorporation of the fluorescent monodansylthiacadaverine into casein at a position corresponding to the migration of gamma-globulins. Treatment with Sepharose-bound protein A effectively adsorbed the factor XIII antibody in the patient's plasma.

Contact activation of blood coagulation is inhibited by plasma factor XIII b-chain

The effect of the purified bovine plasma factor XIII b-chain on contact activation of blood coagulation was studied in human and bovine plasma using either an ellagic acid-phospholipid suspension (Cephotest) or dextran sulfate as activating surface. Contact activation was monitored by the generation of amidolytic activity towards a synthetic chromogenic substrate (S-2302) for factor XIIa and plasma kallikrein. The factor XIII b-chain, which is released from tetrameric factor XIII (a2b2) in the late stages of blood coagulation, inhibits contact activation induced by both activation surfaces mentioned. It was shown that a 5 min preincubation of the factor XIII b-chain with the activation surface increases its inhibitory effect. Light scattering measurements indicated a concurrent binding of the factor XIII b-chain to the Cephotest material. Because factor XIII (a2b2) itself had no such inhibitory activity, the present finding that the factor XIII b-chain inhibits contact activation may point to a novel feed-back inhibition mechanism of blood coagulation.

Characterization of transglutaminases in normal and malignant human leukocytes

Using the fluorescent activity staining procedure, transglutaminases in human monocytes, granulocytes and lymphocytes have been characterized with respect to agarose gel electrophoretic mobility and thrombin dependence. A thrombin dependent transglutaminase was found in concanavalin A stimulated peripheral monocytes. The electrophoretic mobility of this zymogen and of platelet and plasma factor XIII was similar. With stimulated peripheral lymphocytes a similar pattern was observed. However, the potential transglutaminase activity in the lymphocyte factor XIII was lower than that in monocytes. Similar results were obtained when lymphocytes from chronic myeloid and chronic lymphocytic leukaemia patients were examined. Quantitatively, the transglutaminase activity in the leukaemic cells was estimated to be lower than the activity in normal cells. With respect to agarose gel electrophoretic mobility, a similar transglutaminase was found in concanavalin A stimulated human peripheral granulocytes. Although electrophoretically clearly separated from tissues transglutaminase, the granulocyte enzyme did not seem to require thrombin for activation.

The effect of sodium hyaluronate and sodium chondroitin sulfate on the coagulation system in vitro

Healon (sodium hyaluronate) and sodium chondroitin sulfate (CDS) are injected in the ocular cavities in a variety of operations, mainly intraocular lens (IOL) implantation. Both Healon and CDS are structurally similar to heparin. We found that like heparin CDS has an inhibiting action on blood coagulation in vitro. The inhibiting activity is of the antithrombin type. Healon does not possess anticoagulant activity. Since the anticoagulant effect of sodium chondroitin sulfate is observable at concentrations likely to occur in vivo the substance may impair ocular hemostasis.

Localization and characteristics of transglutaminase in the rabbit and human eye

Transglutaminases (transamidases; endo-gamma-glutamine: zeta-lysine transferases) are calcium-dependent enzymes, which cross-link proteins by introducing covalent zeta-(gamma-glutaminyl)lysine pseudopeptide bonds between the molecules. The distribution and characteristics of transglutaminase in both human and rabbit eyes have been studied. Transglutaminase activity was measured with an isotope technique based on the enzyme catalysed incorporation of 14C-putrescine into casein. Electrophoretic characteristics were studied using agarose gel electrophoresis combined with a specific fluorescent activity staining procedure based on the transglutaminase catalysed incorporation of monodansylthiacadaverine into casein. A thrombin-independent enzyme, indistinguishable from the guinea pig liver transglutaminase with regard toi electrophoretic mobility, was found in the choroid/pigment epithelium and ciliary body of the human eye while the lens, retina, iris and vitreous humour did not contain detectable amounts. The lens and the choroid/pigment epithelium of the rabbit eye tissues contained high activities while the activity in the extract from the combined ciliary body/iris was low but measurable.