Cross-reacting material in genetic variants of haemophilia B

Cross-reacting factor IX material (CRM) was immunologically detected in the plasma of 38 normal individuals and 21 out of 22 haemophilia B patients using a rabbit antibody to factor IX. The same reacting material was detected in only nine of these patients using a human antibody. These results indicate that the plasma of the majority of haemophilia B patients contains a protein-lacking biological activity but having antigenic determinants in common with normal factor IX.

Golgi method for old formol-fixed human foetal tissue

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Emergency medical transportation. A survey of California ambulance operations

The most urgent recommendation expressed by physicians, Red Cross officials, ambulance operators and others polled in this ambulance survey was to make much more emergency medical care training available to ambulance personnel. Very few sick and injured receive first aid before an ambulance arrives. Therefore there is also an urgent need to train and motivate the public to provide first aid at the scene of the emergency. Urban ambulances usually respond within 10 minutes, but often rural ambulances take more than 30 minutes to reach an emergency. It is during this interim that lives which could be saved by prompt first aid are lost. Little use has been made of aircraft as emergency ambulances; in 1968, only one emergency trip in 1500 was made by helicopter. Also, California has fewer ambulances which make fewer emergency trips on a population basis than the country at large. Communications at all levels need attention. Seventy-eight percent of the ambulance operations serving the public are not listed among the emergency numbers on the inside front page of telephone directories. Less than ten percent of ambulances have direct radio communication with hospitals. In California most ambulance services are commercially operated and there are formidable financial problems which must be solved before these services can be brought into place as a part of the emergency medical care system.

Von Willebrand factor and platelet adhesiveness

A modification of Salzman's method has been used in an attempt to provide an assay in vitro for the von Willebrand factor. Platelet adhesiveness was increased in von Willebrand's disease by previously coating the beads with normal or haemophilic plasma or cryoprecipitate, whereas von Willebrand plasma had no corrective effect. Antihaemophilic factor (AHF) concentrates were studied in the same way and results compared with experiments in vivo.

Biological findings in Von Willebrand's pedigrees: implications for inheritance

Thirty-one subjects from three families affected by Von Willebrand's disease have been investigated with the following tests: Ivy's bleeding time; platelet adhesiveness according to Salzman; two-stage factor VIII assay. Twelve patients have a complete form of the disease, i.e., a prolonged bleeding time with low platelet adhesiveness, and a reduced factor VIII level. Eight subjects have an isolated low platelet adhesiveness associated in three cases with a prolonged bleeding time. The low platelet adhesiveness in these subjects was corrected, as in Von Willebrand's disease, by infusion of haemophilia A plasma. The dominant autosomal mode of inheritance appears to be due to a pleiotropic gene, expressed in a variety of ways