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Biomedical subjects

R R Pieroni

Publications and source records attributed to R R Pieroni.

At least 19 recordsLinked to original sources
PubMed1980

Radioimmunoassayable serum somatomedin B in normal subjects and in patients with acromegaly and pituitary dwarfism: effects of human growth hormone therapy.

We report the results obtained with a radioimmunoassay for serum somatomedin B (SmB) in 29 normal subjects, in 33 pituitary dwarfs (GHD) and 6 acromegalic patients. There were no significant differences between the basal SmB levels of the GHD and the normal subjects higher value observed in the acromegalic group (p < 0.01). After acute human growth hormone administration a parallel increase of SmB serum levels and plasma growth hormone was seen (r = 0.562; p < 0.01). Of 12 GHD subjects SmB serum levels increased only in five, after chronic hGH administration.

Acromegaly↗
PubMed1979

Analysis of 47Ca kinetics in normal subjects by means of a compartmental model with a non-exchangeable plasma calcium fraction.

1. 47Ca kinetic studies were performed in eight normal young adult males. Plasma, urinary and faecal stable and radioactive calcium and whole-body radioactivity were measured for up to 40 days after intravenous administration of the tracer. 2. The plasma radioactivity data could be fitted to the sum of four exponentials corresponding to a four-compartment model, but this model did not account for the consistently greater 47Ca specific radioactivities in plasma relative to those in urine at the same time in five of the subjects. 3. A non-exchangeable fraction of plasma calcium estimated as 5% of the mass in the plasma compartment was postulated to account for this finding. 4. An estimate of the insensible losses of calcium was obtained from the whole-body radioactivity counting data.

Adult↗
PubMed1978

Carbohydrate metabolism in thyrotoxicosis: studies on insulin secretion before and after remission from the hyperthyroid state.

The effects of thyrotoxicosis on insulin secretion were studied in 11 patients with Graves' disease and compared with the results obtained in 6 of the patients after they had attained clinical remission. Constant glucose infusion (CGI) and acute tolbutamide infusion (AIT) tests were chosen to investigate beta-cell function. For similar means of fasting plasma glucose, basal plasma insulin mean was significantly higher during thyrotoxicosis. During AIT, mean peak insulin was obtained earlier in the hyperthyroid state (2 min) than after remission (4 min), being its level higher in the hyperthyroid state. During CGI, early insulin responses to similar plasma glucose increments, were comparable for both hyper and euthyroid subjects. After 10 minutes of CGI, insulin concentrations in the hyperthyroid state did not increase as in the euthyroid state in spite of comparable increments of plasma glucose, being similar plateau insulin levels attained thereafter. These results suggest the presence of an insulin-resistant state in hyperthyroidism which may either disappear during a chronic glucose infusion and/or be accompanied by a deficient late glucose-induced insulin release.

Adolescent↗
PubMed1978

The adrenal response to exogenous adrenocorticotrophin in patients with infections due to Neisseria meningitidis.

The adrenal response to a soluble form of beta1-24-corticotropin (tetracosactrin [ACTH]: 250 microgram administered intramuscularly) was studied in 28 patients with meningitis due to Neisseria meningitidis (21 with petechiae and seven without) and in six patients with Salmonella typhi bacteremia. Six normal subjects also were tested for adrenal responsiveness at four different times of the day (8 A.M., 12 noon, 4 P.M., and 10 P.M.) and served as controls. The results showed that, whatever the time of testing, patients with meningococcal infections and typhoid fever had unstimulated (basal) levels of plasma cortisol above the 99% confidence limits for the mean unstimulated cortisol levels for the normal subjects. Furthermore, although patients with meningitis without petechiae and subjects with S. typhi bacteremia responded to ACTH stimulation in a manner similar to that of the normal subjects, most subjects with meningitis with petechiae did not have increased levels of plasma cortisol after treatment with ACTH. This lack of response could not be ascribed entirely to the higher basal levels of plasma cortisol in these patients. Patients with meningitis associated with petechiae may have a relatively decreased adrenal response to stimulation with exogenous ACTH.

Adolescent↗
PubMed1977

An accurate determination of human growth hormone content in different pituitary extracts, using a radioimmunoassay with polyacrylamide gel electrophoresis as a bound-free separation system.

Human growth hormone was extrated and purified according to the method of Roos et al. (Roos, P., Fevold, H.R. and Gemzell, C.A. (1963) Biochim. Biophys. Acta 74, 525). A first control of its purification and integrity was performed through molecular weight determination by gel filtration on Sephadex G-100 and on polyacrylamide gel electrophoresis (PAGE). Its biological activity was confirmed by the growth promoted in non-hypophysectomized rats at plateau. The main object, however, was the setting up of accurate, reproducible method tha could furnish the more absolute and comparable values of radioimmunoassayable HGH content in perfect agreement with the results obtained by other laboratories. This was accomplished through a radioimmunoassay system that uses HGH labelled with 125I, where separation of the bound from the free antigen is achieved on polyacrylamide gel electrophoresis, by a modification introduced in the original method of Davis. The resulting values, extremely close to that stated by the KABI-Laboratories (Stockolm), though obtained in quite different conditions of incubation, antibody concentration and with no use of second antibody, represent a confident approach to a comparable measure of this hormone in extracts, which can also be applied to plasma determinations.

Animals↗
PubMed1977

Preparation of high-quality iodine-125-labelled pituitary human follicle-stimulating hormone (hFSH) for radioimmunoassay: comparison of enzymatic and chloramine-T iodination.

A method is described for the enzymatic radioiodination of human follicle-stimulating hormone (hFSH) by a system consisting of lactoperoxidase, hydrogen peroxide and Na125I. It was compared with the Chloramine-T modified technique. A satisfactory specific activity of the labelled hormone was obtained with the enzymatic iodination with much greater immunoreactivity was stability than after Chloramine-T.

Antibody Specificity↗
PubMed1976

Comparison of plasma progesterone assay in women by competitive protein binding (CPB) and radioimmunoassay (RIA).

Plasma progesterone levels during the follicular and luteal phases were compared when measured simultaneously by competitive protein binding (using guinea pig sera as binding agent) and radioimmunoassay (antiserum against progesterone-11-alpha-succinyl bovine serum albumin in rabbits), the values obtained were significantly different within each technique, depending on whether previous thin-layer chromatographic purification of the extracts was employed or not. No significant differences were noticed between CPB and RIA when the chromatographic step was used, but when it was omitted, CPB was greater than RIA at the follicular but not at the luteal phase.

Binding, Competitive↗
PubMed1975

Preparation of high-quality iodine-125-labelled pituitary luteinizing hormone for radioimmunoassay.

High quality pituitary luteinizing hormone labelled with 125-I was obtained after separating out the more heavily iodinated fractions, through starch gel electrophoresis, using the cathodal component (Fraction 1) which was further purified on Sephadex G-100, giving an almost pure 125-I-labelled luteinizing hormone preparation, presenting excellent immunoreactivity and low levels of damage on incubation in plasma. The quality control of the steps of the technique was done with plasma-coated talc (200 mg) which compared favorably, as far as being an indication of intact labelled luteinizing hormone, with the more time-consuming chromatoelectrophoresis.

Animals↗