Immunogenicity studies of foot and mouth disease vaccines at different concentrations of antigen and saponin.

Frenkel-type monovalent O1 and C vaccines were tested for immunogenicity under field conditions, in a large cattle farm. Both vaccines were applied in four dilutions, to furnish different concentrations of antigen, and each dilution was tested with 4 and 8 mg/dose levels of saponin, and without adjuvant. In adult multivaccinated already one eight of the standard bovine dose of both preparations developed a satisfactory booster effect, and presence or absence of the adjuvant played little role.

Evaluation of 133Xe clearance curves in the study of lingual blood flow in dogs.

Lingual blood flow was studied in dogs by the 133Xe clearance technique under control conditions, during epinephrine infusion in response to the combined treatment with Regitin and epinephrine. The composite washout curves recorded during control conditions could be resolved into three monoesponential components. It is suggested that the steep initial slope (component I)is caused by the fraction of blood that perfuses the A-V anastomoses of the tongue.

Effect of renal vasodilatation on intrarenal blood flow distribution.

Total renal blood flow (TRBF) and its intrarenal and intracortical distribution were measured before and during renal vasodilatation induced by acetylcholine infusion using the 133Xe washout, 86Rb uptake and radioactive microspheres distribution techniques. A good agreement was observed between TRBF calculated from 133Xe washout and measured with the electromagnetic flowmeter (FM). 86Rb-TRBF was lower than FM-TRBF and, due to the progressive reduction of renal 86Rb uptake, the difference increased with the increase of flow.

Regional blood flow and collateral circulation of the tongue in the dog studied by hydrogen polarography.

Regional lingual blood flow was measured by hydrogen polarography under control conditions and after the subsequent ligation of pertinent arteries in dogs. The results indicate a nonhomogeneous blood supply for the tongue and the existence of a complex collateral circulation in the lingual areas studied.

The effect of haemorrhage on renal blood flow and intrarenal flow distribution.

Bleeding of dogs to constant arterial pressure of 90 mm/g and 60 mmHg respectively decreased renal blood flow in proportion to pressure reduction. There was no evidence of autoregulation of renal blood flow or of selective renal vasoconstriction. With the radioactive microsphere technique a moderate shift of blood flow from the outer to the inner cortex was observed.