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Biomedical subjects

R N Smith

Publications and source records attributed to R N Smith.

At least 145 records · Page 8Linked to original sources
PubMed1973

Discriminant value of thyroid function tests.

Different thyroid function tests permitted a final classification of 204 consecutive patients with suspected thyroid disorders into three populations (thyrotoxic, euthyroid, and hypothyroid). Linear discriminant analysis was applied to all test results (10 variates) on adjacent population pairs. Two invitro tests (serum protein bound iodine (P.B.I.) and tri-iodothyronine (T-3) uptake values) gave good separation of thyrotoxic from euthyroid patients and fairly good distinction of hypothyroid patients. If a (131)I uptake figure was then added to the in-vitro results most patients (95.5%), including thse initially classified as equivocal, were correctly diagnosed. Other tests, including clinical questionnaires, were poor discriminants.Two new techniques of utilizing the test data were devised. Firstly, the data from the two in-vitro tests were also displayed graphically, and oblique boundary lines derived from the discriminant functions gave better separation of patients than previously used limits or mathematical expressions of "free thyroxine." Secondly, a nomogram incorporating the best four discriminants was designed as a diagnostic aid and proved to be the best means of interpreting the tests.Discriminant analysis of this kind can be used in the interpretation of diagnostic tests in any branch of medicine, and it allows the best use to be made of the available data.

Diagnosis, Differential↗
PubMed1973

Kinetics and bioavailability of two formulations of amiloride in man.

1. Two formulations of [(14)C]-amiloride were compared in six oedema-free subjects in single-dose (20 mg) studies separated by a two-week interval.2. Calculation of the elimination rate constant (K(e)), half-life (T((1/2))) and apparent volume of distribution (V(d)) from serum and urinary data showed no significant difference between the two formulations. The V(d) values (350 to 380 litres) were greater than total body fluid volume suggesting extravascular sequestration of amiloride.3. Serum and urinary amiloride levels were similar with both formulations. Pharmacokinetic parameters were similar to those of an earlier report based on one formulation.4. The calculated amiloride concentration in the renal distal tubule (3 muM to 20 muM) was similar to, but higher than, reported in vitro concentrations of amiloride which reduced sodium transport in isolated membranes.

Adult↗
PubMed1970

Controlled clinical trial of combined triiodothyronine and thyroxine in the treatment of hypothyroidism.

A -double-blind crossover trial of a combined preparation of triiodothyronine and thyroxine (1:4 ratio) compared with thyroxine alone was conducted with 99 patients previously stabilized on. thyroxine as treatment for hypothyroidism. Four patients were excluded during the trial and eight afterwards owing to gross deficiencies in taking the tablets. Of the remaining 87 patients 42 (48%) had no -preference for either medication, 29 (33%) preferred thyroxine alone, and 16 (18%) the combination. A high incidence of unpleasant symptoms was experienced during the two months' treatment with the combined preparation. The serum protein-bound iodine levels were lowered (mean reduction 1.8 mug./100 ml.) on the combination, but the labelled T(3)-resin sponge uptake values were not altered and remained in the normal range. on both treatments.

Adult↗