Ulla Sivertsen Weis-Fogh

Fibrinogen Prepared from Small Blood Samples for Autologous Use in a Tissue Adhesive System

The two-component tissue adhesive system where the one component is a concentrated human fibrinogen solution and the other component is a thrombin solution containing Ca2+ is becoming increasingly important in surgery. In the commercially available tissue adhesive, the fibrinogen is separated from pooled plasma. The risk of transmitting foreign immunogens and viruses, always present when foreign biological materials are used, will be eliminated if the fibrinogen is separated from the patients own blood. A method using ethanol precipitation is described for preparing a concentrated fibrinogen solution from plasma separated from small amounts of blood. The method is fast, the final product can be obtained within 30-60 min after collection of the blood. The recovery is compared with the recovery obtained by separating the fibrinogen with ammonium sulfate precipitation and with cryoprecipitation. The method using ethanol is by far the most profitable, and the product is evaluated by experimental liver surgery in pigs.

Salicylate- and Aspirin-Induced Uncoupling of Oxidative Phosphorylation in Mitochondria Isolated from the Mucosal Membrane of the Stomach

The hypothesis that the damaging effect on the stomach mucosa of salicylic acid and its derivatives is ascribable to an uncoupling of oxidative phosphorylation has been investigated by testing of mitochondria isolated from the corpus gland area of mini-pig gastric mucosa. Mitochondria, influenced by salicylate or acetylsalicylate (0.7-5.6 mmol/l), demonstrated increased respiration rate, decreased respiratory control ratio, and decreased P/O ratio when tested in vitro. Uncoupling of oxidative phosphorylation occurred at a salicylate concentration between 3.5 and 5.6 mmol/l.

Important Factors Influencing the Strength of Autologous Fibrin Glue; the Fibrin Concentration and Reaction Time - Comparison of Strength with Commercial Fibrin Glue

Fibrin glue was prepared from citrated plasma of human donors by means of ethanol. The outcome was a fibrinogen concentrate with a mean concentration of 43 mg/ml. The fibrinogen was converted to fibrin by the addition of 0.3 part of thrombin solution, 150 NIH U/ml, containing 100 mM calcium chloride. In a rat model full-thickness skin grafts were sealed with the glue, and the adhesive strength was measured at different fibrin concentrations, and after a variable reaction time, and compared to commercial fibrin glue (Tisseel). The strength of ethanol-prepared glue was directly proportional to the fibrin concentration, and increased rapidly within the first minutes of the reaction time. The strength of the commercial glue could be obtained with autologous fibrin glue at the same fibrin concentration.

AUTOLOGOUS FIBRIN GLUE--PREPARATION AND CLINICAL USE IN THORACIC SURGERY

Autologous fibrin glue was used in 20 patients undergoing lung resection to reduce pulmonary air leaks and improve hemostasis. The fibrinogen in the glue was prepared by ethanol precipitation of plasma separated from 88 ml of the patients blood. The mean volume of fibrinogen concentrate +/- SD was 4.9 +/- 0.5 ml with a fibrinogen concentration of 28 +/- 5 mg/ml. The yield obtained by the separation was 81% +/- 9%. One part of fibrinogen concentrate was converted to solid fibrin by means of 0.3 parts of thrombin solution. The outcome was 6.4 ml of two-component fibrin glue. The preparation was performed in a closed system to ensure sterility, and was completed within 90 min. Pulmonary air leak decreased following sealing of the resection lines with autologous fibrin glue and the hemostasis was effective. No adverse effects were observed, and all cultures from the glue were negative. Autologous fibrin glue has the obvious advantages of safety from transmission of viral diseases and from immunological reactions. In summary, we report a new technique for preparing autologous fibrin glue with a high concentration of fibrinogen making it a safe and effective sealant of pulmonary air leak and hemostatic agent in thoracic surgery.

The Use of Autologous Fibrin Adhesive in Skin Transplantation

A method for preparing concentrated fibrinogen for use in autologous fibrin adhesive is described. The adhesive was used in seven patients with eight chronic leg ulcers. The ulcers were divided into two equal sections, and the adhesive was used to seal split-thickness skin grafts in one section, while no adhesive was used to seal the grafts in the other section of the ulcer. The strength of adhesion was measured 3 1/2 minutes after transplantation of a 1-cm2 test split-thickness skin graft. In the sealed grafts, the breaking strength varied from 12 to 26 gm. In the unsealed transplants, the strength was less than 5 gm. The take of the meshed split-thickness skin grafts was equal in the sealed and the unsealed areas, varying from 90 to 100 percent. Biopsies taken on day 7 showed a splitting between graft and recipient bed in half the unsealed grafts; none of the sealed grafts showed splitting, indicating a more stable graft in the sealed areas. Biopsies taken on day 21 showed no difference between sealed and unsealed grafts.

Autologous fibrin sealant in reconstructive rabbit oviduct microsurgery

A simple method for preparing concentrated fibrinogen for use in a tissue adhesive system is described. Approximately 75% to 80% of the plasma fibrinogen can be separated and concentrated within 45 to 60 minutes from a small blood sample collected from the patient before the operation. Autologous fibrinogen prepared by this method was evaluated in reconstructive microsurgery of the rabbit oviduct.

The Influence of Acetylsalicylic Acid (Aspirin) on Gastric Mucosal Content of Energy-Rich Phosphate Bonds

The mucosal content of adenosine triphosphate, adenosine diphosphate and adenosine monophosphate in mini-pig corpus gland area and in pyloric gland area was examined after aspirin ingestion in acute experiments and after ingestion for several weeks. Ingestion of aspirin led to a statistically significant decrease of adenine nucleotide content in corpus gland and in pyloric gland area. An inverse correlation between the pH of the aspirin suspensions and the size of the decrease was established in the short-time experiments. In non-affected pyloric gland area mucosa and adenine nucleotide content was significantly lower than in the corpus gland area. Pyloric mucosa was more susceptible to aspirin-induced lowering of adenine nucleotide content than was the corpus mucosa. Prolonged aspirin ingestion led to statistically significant reductions of adenine nucleotide pool. The findings explain the decrease in mucous secretion and in acid secretion demonstrated in several studies. The finding of lower and more susceptible adenine nucleotide pool in the pyloric area might be the explanation for the preponderant occurrence of aspirin ulcerations in this region.

Autologous Fibrin Glue—Clinical Use and Sealing of High-Porosity Vascular Prostheses

Autologous fibrin glue was prepared in a new way by means of ethanol. From 42 patients 44 mL of blood with a mean plasma fibrinogen concentration of 3.7 mg/mL was drawn. The product of the preparation was a mean of 2.5 mL of fibrinogen concentrate with a concentration of 28 mg/mL. After addition of 0.3 part of thrombin solution containing calcium chloride and aprotinin, an antifibrinolytic agent, the total volume of two-component fibrin glue was 3.3 mL. The preparation was done in a closed system to ensure sterility and com pleted within ninety minutes. Twenty high-porosity double-velour vascular prostheses were sealed with autologous fibrin glue in the laboratory. The pro stheses were tight for blood up to a pressure higher than 300 mmHg, which was comparable to vascular prostheses impregnated with collagen, but to more than twice the pressure of 130 mmHg, where vascular prostheses preclotted with blood started leaking. Autologous fibrin glue imparts a nice white vascular graft with superior handling characteristics, since it is nonsticky compared with blood-clotted grafts and softer and more pliable than the vascular prostheses impregnated with collagen from the manufacturer. In addition autologous fi brin glue has the obvious advantages of safety from transmission of viral dis eases and from immunologic reactions.

Histomorphological Evaluation of Wound Healing of Rabbit Oviduct after Microsurgical Reanastomosis with the Use of Autologous Fibrin Adhesive, Human Fibrin Adhesive or Poly-Glycolic Acid Suture

The morphology of the healing process of microsurgical reanastomosis of the rabbit oviduct with the use of fibrin adhesive, autologous and heterologous, and conventional sutures is described. Both oviducts in 48 rabbits were cut and reanastomosis were performed. The rabbits were killed at different intervals after the operations, ranging from 2 h to 28 days, and the anastomoses were evaluated by histomorphological examination. The autologous fibrin adhesive was absorbed after a week and an uncomplicated healing was observed. Heterologous fibrin adhesive caused a granulomatous inflammation interpreted as an immune reaction of the host to the foreign protein, and conventional suturing resulted in severe tissue damage with an intensive inflammatory reaction.

The effect of pH on the K+ movements across the human platelet membrane during in vitro incubation in plasma at 37°C

Abstract 1. (1) The K + concentration in human blood platelets, separated at room temperature from citrated platelet-rich plasma at pH 7.1, was 88 μmol/10 11 platelets. 2. (2) Changing pH in the plasma altered immediately the intracellular K + concentration in platelets. An equilibrium was reached within 60–90 min and no further change was observed during the next 90 min. The maximum value was found at pH 6.0–6.4. 3. (3) The velocity of passive K + efflux varied with pH, having a minimum value at pH 6.0–6.4. Increasing the pH to 7.9 accelerated the velocity by a factor of 15. This was found in platelets incubated with ouabain to inhibit the active (Na + , K + )-pump.