A collaborative study to establish the 1st International Standard for factor XIII plasma.

BACKGROUND: An international collaborative study, involving 23 laboratories, was carried out, under the auspices of the FXIII Standardization Working Party (SWP), to calibrate the 1st International Standard (IS) for factor XIII (FXIII) plasma. METHODS: Potency estimates for the proposed candidate FXIII plasma (preparation Y: NIBSC code 02/206) were calculated relative to locally collected normal plasma pools (pool N), for both FXIII activity and antigen levels. RESULTS: Estimates of FXIII activity potency for preparation Y showed good agreement between laboratories, with an interlaboratory geometric coefficient of variation (GCV) of 11.5% and a mean value of 0.91 U mL(-1). Furthermore, there was a negligible difference in potencies by two commercially available methods, the potencies differing only by approximately 1%. Estimates of FXIII antigen (A(2)B(2) complex) potency for preparation Y showed good agreement between laboratories, with an interlaboratory GCV of 16.3% and a mean value of 0.93 U mL(-1). Accelerated degradation studies showed that the proposed standard is very stable, with a predicted loss of activity (and antigen) per year of< 0.06% at the recommended storage temperature of -20 degrees C. CONCLUSIONS: The suitability and potency of preparation Y were considered by the participants, members of the ISTH/SSC FXIII Subcommittee, the Scientific and Standardization Committee and the SWP. Following their approval, preparation Y was proposed to and accepted by the Expert Committee on Biological Standardization of the World Health Organization to be the 1st IS for FXIII plasma with an activity potency of 0.91 IU per ampoule and an antigen potency of 0.93 IU per ampoule.

[Adhesive strength studies of biologic tissue adhesives]. / Klebefestigkeitsuntersuchungen an biologischen Gewebeklebern.

Different tissue adhesives including an own fibrin adhesive on the base of the human plasma fraction Cohn I were investigated in relation to their adhesive strength tension. These investigations were carried out on lyophilised skin grafts in vitro. The adhesive strengths were equal in case of the Cohn I adhesive, the Tissucol-Kit and also with Beriplast. These investigations will contribute to optimize an adhesive system.

Adhesives in orthopaedic surgery. A review of the literature and in vitro bonding strengths of bone-bonding agents.

Adhesives may offer a number of advantages over conventional metal osteosynthesis in the treatment of fractures: ease and speed of fixation are improved, they have the anatomy to anatomically coapt small fragments, and hardware removal is not necessary. A review of the literature was performed to evaluate experiments with collagen and other biologic adhesives, epoxy resins, polyurethane foam, cyanoacrylates, zinc polycarboxylate, polymethylmethacrylates, and fibrin adhesives pertaining to osteosynthesis. Cyanoacrylates, polymethylmethacrylates, and fibrin adhesives are currently being investigated. These agents are tested to evaluate their bone-bonding strength. Cyanoacrylates of biologically tolerated chain length did not develop useful bonding in cancellous bone; they bond well to cortical bone only with meticulous surface preparation. Fibrin adhesives developed only minimally useful bonding. Polymethylmethacrylate developed surgically useful bonding in osteosynthesis where conventional fixation is impossible.