No abstract available

[en] Do hypertensive patients, HT, with unilateral cerebrovascular disease, UCVD, maintain autoregulation in the diseased hemisphere and the normal hemisphere when their blood pressure is reduced using Captopril, an angiotensin converting enzymeinhibitor. Nineteen patients with HT and UCVD underwent global and regional cerebral blood flow, CBF, measurements: ten on conventional triple therapy and then with Captopril without or with a diuretic and nine twice on triple therapy as a control group. CBF ml/min was obtained after an intravenous injection of Tc-99m labelled patient's red cells with a computer linked gamma camera over the vertex and probe over the aorta. Using deconvolution analysis, regional CBF is given by regional cerebral volume divided by regional mean transit time. Results in the Captopril group showed a 10% fall in mean blood pressure with Captopril and a 10% rise in blood flow to the involved hemisphere. In the control group there was a 4% fall in pressure, together with an 11% fall in CBF to the involved hemisphere. Captopril appears to maintain autoregulation in cerebrovascular disease. (Author)

[en] This paper presents transit time results for the unobstructed urinary tract together with a description of the changes so far observed in radiation-induced obstructing uropathy. (author)

[en] The kidney has two populations of nephrons, cortical CN and juxtamedullary JMN. CN are the majority 85%, show autoregulation and have short loops of Henle; JMN have long loops of Henle. Disorders such as essential hypertension EHT and drugs are thought to have different effects on CN and JMN. A stochastic approach with a linear system model has been developed using I-123 orthoiodohippurate IOIH (2mCi) which tracer is taken up and proximally tubularly secreted by both CN and JNN in proportion to flow. In 12 normal volunteers Indoramin increased flow to CN by 17% whereas in 6 others Ibopamine reduced CN flow by 19% (p<0.05) but tended to increase JMN flow causing a water diuresis. The study shows that the two populations of nephrons should be considered separately in the pathophysiology and pharmacology of renal disorders

[en] A non-invasive test of nephron function, the real renal parenchymal transit time (F.T.T.) index, is shown to be as accurate as antegrade pressure measurements in diagnosis of renal outflow obstruction. It is more sensitive than conventional methods of demonstrating the associated obstructive nephropathy. P.T.T. is useful in following the effects of surgery, or of temporising, in patients with confirmed or potential outflow tract obstruction. Renal radionuclide P.T.T. analysis gives the functional information essential for the management of patients in whom intravenous urography reveals a dilated renal pelvis. (author)

[en] This new method depends on a linear system approach, thus avoiding the problems of the lack of constancy of the partition coefficient and diffusion volume that occur with the xenon washout technique, particularly in cerebrovascular disease. Using first pass and equilibrium data after an intravenous bolus of ⁹⁹Tcsup(m)-labelled albumin or red cells, regional volume is measured as a fraction of total blood volume and regional mean transit time by deconvolution analysis of an input curve from an aortic probe with the activity/time curve from each region of interest. Reproducibility studies are reported together with results in patients before and after surgery for carotid occlusion, in subarachnoid haemorrhage and in a study of a hypotensive agent. (author)

[en] We describe a new non invasive technique for measuring the regional distribution of cerebral flow in ml/min. by means of an intravenous bolus of 99m Tc-albumin and a computer linked standard gamma camera. Results are presented in patients with normal middle cerebral regions and those with unilateral neurovascular disorder affecting the middle cerebral region. Regional cerebral flow measurements distinguish between the normal and affected in a significant way

[en] The aim of this study is to develop a method for assessing the natural history of cerebrovascular disease in patients with hypertension in order that the effects of controlling hypertension may be judged. By developing a quantitative noninvasive method for measuring regional cerebral flow and internal carotid appearance times it is hoped that drugs intended to inhibit the continued formation of atheroma and drugs intended to aid the dissolution of atheroma, may be objectively evaluated. (Auth.)

No abstract available

[en] A comparison of methods for calculating the renal clearance of EDTA from the plasma disappearance curve, after a single injection, has been made. Measurements were made on 38 patients, using external monitoring and venous blood sampling techniques, over a period of 24 h after an injection of 100 μCi of ⁵¹Cr-EDTA. The results indicate that the period 3 - 6 h after injection is suitable for sampling the post-equilibrium part of the plasma disappearance curve for values of the glomerular filtration rate (GFR) in the range 0 - 140 ml/min. It was also found that, to within the individual measurement errors, the values of the clearance calculated by using the post-equilibrium period only (PES clearance) can be considered to show a constant proportionality to the values calculated by using the entire plasma disappearance curve (total clearance). (author)