The role of the radioisotope phallogram in the investigation of vasculogenic impotence.

Patients complaining of impotence were investigated through a multi-disciplinary approach to define the factors involved. Radioisotope phallography was performed on all the patients using 99Tcm-labelled red blood cells (RBCs) and dynamic records of the variation in activity over the penis were obtained. During the course of the study an intravenous injection of a vasodilator (isoxsuprine HCl) was administered. An analysis of the data provided quantitative parameters for measuring the changes in penile blood flow and penile blood volume in response to the vasodilator injection. The results indicate that the radioisotope phallogram is useful both in the diagnosis of vasculogenic impotence and in indicating the method of treatment.

The effects of propylthiouracil and other drugs on the uptake of 75Se-selenomethionine by the pancreas.

The influence of pre-treatment with a variety of agents on the uptake of 75Se-selenomethionine by the rat pancreas has been studied. The agents ranged from thyroid hormones to protein synthesis inhibitors but out of 16 tested, only propylthiouracyl (50 mg/kg i.p. administered for 3 days prior to 75Se-methionine injection) resulted in a significant increase in the pancreatic uptake (17%) and in the pancreas liver concentration ratio (25%). Seven of the agents resulted in significant reductions in the pancreas/liver concentration ratios. No significant effects were produced by the addition of carrier methionine or selenomethionine (in the range 10-250 micrograms/kg body weight) to the injected radiopharmaceutical. It was concluded that many factors may influence the uptake, but that the interrelationship of hypothalamus, pituitary and pancreas is of particular interest.

Considerations of the application of indicator dilution methods to the measurement of the flow rates of fluids.

In circumstances when the flow velocity of a fluid non-homogeneous, difficulties arise in the application of the familiar indicator dilution equations. These and other relevant relationships have therefore been derived from first principles in order to clarify the conditions in which they may be expected to apply. It is shown that the method of introduction of the tracer into a fluid stream as well as its method of measurement are important factors, and the implications of these results for biological measurements are discussed. Illustrations are provided of the indicator dilution curves which are likely to be obtained under conditions of laminar fluid flow in a straight tube and when the diffusion of the tracer can be neglected.

Iron metabolism in patients undergoing regular dialysis therapy.

Thirteen patients with chronic renal failure maintained on regular renal dialysis were studied. Seven proved to have iron deficiency on the basis of marrow iron studies, reticulocyte iron uptake, and saturation of the serum iron-binding capacity. They absorbed iron when given it by mouth and were able to utilize it for haemoglobin formation. Iron-deficient patients given 600 mg of ferrous sulphate daily for three months showed an increase in haemoglobin, but the failure to replace stores of iron is probably related to their relatively limited ability to absorb iron and the variable but sometimes considerable blood loss occurring with each dialysis.The loss may be occult, and prolonged iron therapy may be required. This is most safely achieved by giving iron by mouth.