Four heparin preparations: anti-Xa potentiating effect of heparin after subcutaneous injection.

Four different heparin preparations--sodium and calcium salts of the same batch of heparin (mean molecular weight 15,000), low molecular weight sodium heparin (mean m.w. 9,000) and high molecular weight sodium heparin (mean m.

Immunoradiometric assay of factor VIII related antigen, with observations in 32 patients with von Willebrand's disease.

A solid phase non-competitive immunoradiometric assay (IRMA) has been developed which allows measurement of factor VIII related antigen (VIIIR:AG) levels in normal plasma as low as 2.5 x 10(-4) U/ml. The assay is based on the extraction of VIIIR:AG from test plasma by means of polystrene tubes coated with a specific unlabelled anti-VIIIR:AG rabbit antiserum and subsequent labelling of the extracted antigen with 125I-labelled anti-VIIIR:AG rabbit IgG.

The immune response of brown trout (Salmo trutta L.) to injection with soluble antigens.

The immune response of brown trout (Salmo trutta) to horse serum and keyhole limpet haemocyanin was studied. Intraperitoneal and intramuscular injections were used, with and without adjuvant, in 209 fish. Complement-fixing antibodies (CFA) and precipitins were produced to both antigens.

Heterozygous and homozygous factor XI defect in consanguineous family.

A woman with symptoms of prolonged post-traumatic bleeding was found to have a severe defect of factor XI, and was thought to be homozygously affected. Both her parents, who were first cousins, and all her three children, though asymptomatic, showed a moderate defect and appeared to be heterozygous. Both her parents' factor XI levels were about twice those in her children, and this was thought to be an age effect.

A computer program for the analysis of parallel-line bioassays of clotting factors.

An interactive computer program for the analysis of clotting factor assays is described. The program provides potency estimates against a standard, and will compare the observed and expected responses of a treated patient. Tests for validity of curve fitting are provided, with a number of optional transforms.

Simple screening tests for the diagnosis of isolated clotting factor defects. With special reference to 'contact factor' defects.

Reagents may be prepared from normal plasma and used with the prothrombin time and partial thromboplastin time tests to distinguish isolated defects of factors I, II, VII, VIII, IX, X, XI, or XII.

Gastric brooding: unique form of parental care in an Australian frog.

The recently described leptodactylid frog Rheobatrachus silus of Queensland, Australia, exhibits a unique form of parental care. The female carries embryos and young in the stomach, propulsively ejecting the juveniles.