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Biomedical subjects

A Albertini

Publications and source records attributed to A Albertini.

At least 199 records · Page 11Linked to original sources

Methodological effects on the quantitation of serum ferritin by radio- and enzymoimmunoassays.

Serum ferritin is normally quantitated by sensitive radio- or enzymoimmunoassays, which are based either on a competitive reaction between the unlabelled and labelled antigen (RIA), or on a non-competitive reaction between the sample and the labelled antibody (IRMA and ELISA). Both methods appear to be satisfactory for the clinical evaluation of serum ferritin. However, the effect of these methods on the quantitation of serum ferritin has never been carefully studied. This paper describes and compares five different immunoassays for the evaluation of serum ferritin: two competitive RIAs, one non-competitive IRMA and two non-competitive ELISAs. The same anti-ferritin antibody and ferritin standards were used for all the assays. The RIAs were found to be less sensitive than either the ELISAs or the IRMA, and all showed a similar degree of cross-reactivity with ferritin extracted from spleen and HeLa cells. A significant difference between the assays was found in the determination of serum ferritin: in fact the RIAs over-estimated serum ferritin by about 50% more than the IRMA, whereas the ELISAs under-estimated serum ferritin by about 15% less than the IRMA.

Antibody Specificity↗

Parathyroid hormone and calcitonin in glucose regulation.

Blood glucose, insulin, calcium (Ca), phosphorus (P), parathyroid hormone (PTH) and calcitonin (CT) were evaluated in 8 normal children, aged 17-41 months, during an oral glucose load; in 7 normal children, aged 15-42 months, during i.v. glucose infusion; and in 6 normal children, aged 19-40 months, during glucagon administration. During the oral glucose tolerance tests the mean maximum decline of Ca (8.63%) and p (12.66%) was at 120 min, while PTH and CT significantly increased from basal values of 1.36 ng/ml +/- 0.21 and 97 pg/ml +/- 14 to 2.20 ng/ml +/- 0.22 and 140 pg/ml +/- 13, respectively, at 45 min. During i.v. glucagon administration the mean maximum decline of Ca (9.64%) and P (12.28%) was at 30 min. PTH levels rose significantly from basal values of 1.2 mg/ml +/- 0.22 to 2.1 ng/ml +/- 0.32 at 45 min, while CT increased rapidly from basal levels of 90 pg/ml +/- 14 to 127 pg/ml at 15 min. In conclusion, increases in glucose and insulin due to ingestion or infusion of glucose, or to glucagon injection, are therefore not only associated with a fall in serum Ca and P but also with rises in PTH and CT.

Blood Glucose↗

A bacterial test in liquid culture for the detection of mutagenic activity of antibacterial compounds: studies with cephalosporine HR 756.

A detailed procedure for the short term evaluation of mutagenic activity in the Salmonella assay in liquid cultures is given for Cephalosporine HR 756. The essential steps of the test are: a) determination of absence of interference of the pKM101 plasmid present in the bacterial tester strains, b) determination of the doses of the antibiotic required to obtain a limited killing, c) introduction of appropriate controls with known mutagenic compounds active in the presence and in the absence of metabolic activation, d) segregation of mutants. Following this procedure we have determined the absence of any mutagenic activity in the liquid assay of Cephalosporine HR 756.

Animals↗

Parathyroid hormone and calcitonin levels in vitamin D deficient rickets.

In six infants aged between 5 and 8 months with vitamin D deficient rickets, we have studied blood levels of calcium (Ca), phosphorus (P), alkaline phosphatase, immunoreactive parathyroid hormone (PTH) and calcitonin (CT), as well as urinary excretion of Ca, P, hydroxyproline and cyclic AMP, both under basal conditions and during a 4h infusion of 20 mg/kg 10% Ca gluconate in normal saline. Under basal conditions all the infants had high alkaline phosphatase (range: 470--770 U.I./1); PTH (range: 620--1200 pg Eq/ml) and CT (range: 440--750 pg/ml) but two infants had hypocalcaemia and four had normocalcaemia and hypophosphataemia. The urinary Ca excretion was low whereas the urinary P, hydroxyproline and cyclic AMP excretions were high. During Ca infusion the total serum Ca and CT levels increased, while alkaline phosphatase and PTH fell. After the end of the infusion, CT levels fell perceptibly; phosphaturia, hydroxyprolinuria and cyclic AMP decreased on the day of the infusion.

Alkaline Phosphatase↗

Pancreatic endocrine response to the first feed in term newborn infants.

Blood glucose, insulin, C-peptide and glucagon were evaluated in 36 newborn term infants at birth, and before and 60 min after the first feed during the first day of life. Under basal conditions glycaemia diminished during the first day of life and glucagon increased, while insulin and C-peptide did not show any variation. The C-peptide: insulin molar ratio was higher in the newborn than in adults because of the longer half-life of C-peptide, probably due to reduced renal function in the neonatal period. The subjects were divided into two groups: 18 newborn infants were given a feed of commercially available milk powder reconstituted in water at 10% (5 ml/kg); the other 18 were given a feed of 5 ml/kg 10% glucose solution. In each group 6 were given the first feed after a fast of 6 h, 6 after a fast of 12 h and 6 after a fast of 24 h from birth. After the first feed with milk, the average increase of glycaemia was 19.83 mg%, of insulin 6.06 muU/ml, and of C-peptide 1.88 ng/ml. After the first feed with glucose the average increase of glycaemia was 13.59 mg%, of insulin 2.46 muU/ml, and of C-peptide 0.59 ng/ml. Glucagon did not show significant changes after the first feed.

Blood Glucose↗

[Calcitonin, gastrin, parathyroid hormone and the autonomic nervous system].

Stimulation of the beta-adrenergic terminations was employed to determine whether calcitonin-secreting thyroid C cells are derived from the neural crest. Calcitonin secretion was increased, whereas parathormone, insulin and gastrin values were not significantly changed. In addition, administration of a beta-blocking drug before ethanol led to a marked fall in calcitonin with respect to the baseline. Once again, other hormone levels were not affected.

Calcitonin↗

[Radioimmunological determination of circulating thyroid hormones].

In our study of the thyroid function, the methodological aspects and clinical significance of TSH, T4, T3 and their respective free fractions (FT4 and FT3), are examined. The RIA of TSH is the best for the diagnosis of hypothyroidism and also for the evaluation of the effect of thyroid hormone substitution therapy. This, united with T4 and T3 assay, allows a total evaluation of the thyroid state. The new method, recently introduced, for direct assay of free fractions, using a chromatographic separation of Sephadex LH 20, is extremely useful for follow-up of patients with thyroid disfunction.

Humans↗

Blood pressure control in end-stage renal disease in man: indirect evidence of a complex pathogenic mechanism besides renin or blood volume.

1. In twenty-three uraemic patients on regular dialysis, plasma renin activity and blood volume were measured before and after a single dialysis. Three groups were identified; the first had a low or normal plasma renin activity and a high or normal blood volume, the second had a high plasma renin activity and a low blood volume and the third had both variables above normal. 2. In spite of these differences, diastolic blood pressure before and after dialysis was the same in the three groups and multiple regression analyses failed to demonstrate any dependence of blood pressure on plasma renin activity, blood volume or body weight taken separately or together. 3. We conclude that other factors besides plasma renin activity and blood volume are important in maintaining arterial hypertension in terminal renal failure.

Adult↗

[Human chorionic somatommamotropins (HCS or HPL) : radioimmunologic determination and clinical significance].

The AA. have studied a new standardized radioimmunologic method for the routine determination of HCS. All the steps of the analysis have been studied, in particular those concerning the reability test and the precipitation of the complex with PEG. The best conditions were found when PEG 6000 is used at a concentration between 14-16 g in 100 ml (v/w), dissolved in veronal buffer, pH 7.4--9.4, with a dilution of protein (bovine serum) 1:4 in the incubation mixture. The reability test have given very good results. The c.p.m. of the analysis are plotted with a logit plot by computer which directly gives the values in ng/ml of the hormone in the plasma sample. The results obtained with this method are compared with those of the literature; the most striking difference in the present method appears in the last trimester of pregnancy in which the result have a low S.D. and can give a good help in clinical management of pregnant patients.

Abortion, Threatened↗

[Diazoxide test in the diagnosis of arterial hypertension: modifications in the levels of renin and aldosterone in blood of patients with various restrains of the renal function].

The AA. have applied the diazoxide test for the screening of primary hiperaldosteronism to 22 nephropatic patients suffering from hypertension and with different degrees of renal function. In 22 patients an increase in PRA and aldosterone values always followed the diazoxide infusion. Only one patient, likely suffering from primary aldosteronism, showed no increase in PRA and aldosterone values. The diazoxide infusion had no influence on renal, pancreatic and cardiovascular function. Therefore, this can be considered as a valid test easy to be performed in a short time, also in nephropatic patients who are very sensitive to pharmacological noxae.

Adolescent↗