SummaryAlthough the oral anticoagulants provide effective prophylaxis against postoperative deep vein thrombosis following fracture of neck of femur there is a need for an antithrombotic agent which needs less laboratory control and does not cause haemorrhagic complications. It has been suggested that drugs causing inhibition of platelet function may fulfil these requirements. A controlled trial was carried out in which aspirin, RA 233, or a combination of these drugs was compared with a placebo in the prevention of post-operative deep vein thrombosis. In thirty patients undergoing surgery for fractured neck of femur the incidence of post-operative calf vein thrombosis, as detected by 125I-fibrinogen scanning, was not significantly different between the untreated and treated groups.

Summary. As part of a study of the thrombogenic properties of dialysis membranes a test‐cell has been devised in which the retention of platelets in the presence of different membranes can be measured. This provides a test for platelet adhesiveness which in certain aspects is more sensitive and reproducible than a glass bead column technique. The normal range for platelet adhesiveness was found to be 31 ± 9% using whole blood and 19 ± 3% using platelet‐rich plasma. The platelet adhesiveness value was largely independent of the packed red cell volume but was, in part, dependent upon the presence of adenosine diphosphate. The membrane test‐cell system was sensitive enough to demonstrate a constant and significant fall in platelet adhesiveness following salicylate ingestion. It was convenient in use as blood anticoagulated with 3.8% sodium citrate allowed delays of up to 1 hr without influencing the result. Heparin was found to have an inhibitory effect on platelet adhesiveness. The use of twin test‐cells allowed platelet adhesion to two different dialysis membranes to be studied simultaneously. It was found that fewer platelets adhered to Cuprophan PT 150 membranes than to PT 300 membranes suggesting that PT 150 membranes may be less thrombogenic in vivo.

SummaryAn account is given of the effects of boomslang venom in man. Evidence was found of a fibrinolytic state apparently secondary to the coagulant action of the venom. These features rapidly responded to the administration of specific antivenom. In vitro studies, using a homogenate of boomslang parotids, confirmed the coagulant properties of the venom and showed them to be of much greater potency than the proteolytic actions.

This paper describes experience over an 18-month period of a new preparation of factor VIII, cryoprecipitate, prepared by the Regional Blood Transfusion Service from human plasma. This relatively simple and inexpensive method selectively extracts the factor VIII leaving behind the other blood products for use in other ways. Replacement therapy in the treatment of haemophilia has been generally regarded as inadequate due to the difficulty in obtaining potent antihaemophilic globulin in sufficient amounts, and cryoprecipitate represents a useful advance. Bleeding episodes in 25 patients with factor VIII deficiency have been treated with cryoprecipitate on 41 occasions and an assessment of the haemostatic effect of this material has been made in treating haemarthrosis, muscle haematomata and the management of major and minor surgical operations. Routine follow-up over a 6 month period was undertaken to determine the incidence of side effects. Two cases of hepatitis were found, possibly resulting from cryoprecipitate therapy. However, both patients had also received blood or fresh frozen plasma and the source of the hepatitis virus must remain in doubt. No factor VIII inhibitors were found despite repeated courses of therapy in several patients. The advantages and disadvantages of cryoprecipitate are set out and its encouraging place in the management of haemophilic bleeding assessed.