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A method to directly measure the formation of blood coagulation Factor XIIIa in platelet-poor plasma unmodified by heat is described. The synthetic peptide glycyl-L-prolyl-L-arginyl-L-proline, a fibrin-polymerization inhibitor, was used to prevent clotting of platelet-poor plasma. Plasma was diluted to a final concentration of 2.5% (v/v) in 0.1 M Tris-HCl, pH 8.5, buffer containing 25% glycerol, 5 mM calcium chloride, and 0.25 mM glycyl-L-prolyl-L-arginyl-L-proline and then activated by thrombin (20 U/ml) for 15 min. The Factor XIIIa-catalyzed incorporation of [3H]putrescine into Hammersten casein was used to measure Factor XIIIa formation. The assay detected Factor XIIIa in 2.5 to 50 microliter of thrombin-treated plasma. When purified Factor XIII was added to Factor XIII-deficient plasma, there was complete recovery of the Factor XIII added. Glycyl-L-prolyl-L-arginyl-L-proline did not inhibit Factor XIIIa activity in thrombin-treated plasma or purified platelet Factor XIIIa. Glycerol stabilized Factor XIIIa activity in thrombin-treated plasma and buffer for 60 min. The presence of fibrinogen in plasma did not modify the assay results. The time course of thrombin-catalyzed Factor XIIIa formation in platelet-poor plasma containing glycyl-L-prolyl-L-arginyl-L-proline was directly measured using the assay.

A series of 110 patients out of 2,200, who had undergone Billroth II partial gastrectomy for benign lesions, between 1945 and 1980, was reviewed in order to perform clinical, biochemical and endoscopical examinations. In this group 9 patients (8.18%) showed gastric stump cancer and in 4 (3.63%) esophageal cancer was detected. The average time interval between previous operation and carcinoma diagnosis was of 28 years and 6 months. Eight patients out of 9 were males aging from 47 to 82, while the only woman was 65 (overall average: 63). The stump cancer presents at the same age and gives the same symptoms as primitive gastric carcinoma, but with worse results and prognosis. After having underlined some pathogenetic problems, the Authors show personal results and confirm the utility of an accurate endoscopical and clinical follow up especially for patients operated on since more than twenty years.

Two well-characterized antigens [Mac-1 and lymphocyte-function-associated antigen (LFA-1)], expressed on a variety of leukocytes, are members of a family of surface proteins associated with multiple recognition functions. To analyze expression of these proteins during macrophage development, we utilized both radioimmunoassay and flow cytometry. As previously reported, Mac-1 is expressed on murine macrophages in all stages of development. We found LFA-1 to be present on murine mononuclear phagocytes but only in certain stages of their development. Specifically, we found LFA-1 was expressed on murine tissue macrophages but only on those activated in vivo by bacillus Calmette Guerin (BCG) or, to a lesser extent, primed by pyran copolymer. Although LFA-1 was absent on inflammatory (responsive) and resident tissue macrophages it was also present on blood-borne monocytes. Activated macrophages also selectively expressed the H-11 and Ly-6 antigens. Thus, these data indicate that LFA-1 is selectively expressed on mononuclear phagocytes of the tissues but only on those in the primed and activated stages of development.

The effect of fibrin polymers on thrombin-catalyzed factor XIIIa formation was studied in afibrinogenemic plasma. Fibrin polymers derived from des A fibrinogen and des A,B fibrinogen increased sixfold the rate of thrombin-catalyzed factor XIIIa formation in the presence of EDTA. Calcium chloride accelerated factor XIIIa formation 14-fold in the presence of des A,B fibrinogen without increasing the rate of thrombin formation. Fibrinopeptides A and B had no effect on factor XIIIa formation in afibrinogenemic plasma. Des A,B fibrinogen reduced by 20- to 40-fold the thrombin concentration required to activate factor XIII. Glycyl-L-prolyl-L-arginyl-L-proline (gly-pro-arg-pro), a fibrin polymerization inhibitor, inhibited des A and des A,B fibrinogen from enhancing thrombin-catalyzed factor XIIIa formation. Gly-pro-arg-pro did not modify factor XIIIa formation in afibrinogenemic plasma and did not inhibit thrombin cleavage of the chromogenic substrate S-2238. These results demonstrate that fibrin polymers accelerate thrombin-catalyzed plasma factor XIIIa formation.