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Biomedical subjects

D Maestri

Publications and source records attributed to D Maestri.

28 records · Page 2Linked to original sources
PubMed1991

Reduced ACTH/cortisol responses to naloxone in men with Parkinson's disease.

In order to establish whether the inhibitory control exerted by endogenous opioid peptides on ACTH/cortisol secretion changes in patients affected by Parkinson's disease, ten parkinsonian male subjects and eight age matched normal controls were tested with naloxone (4 mg an i.v. bolus plus 10 mg infused in two hours). In a different occasion all subjects were tested with normal saline. Experiments started at 09.00 h. Plasma ACTH and cortisol concentrations showed a slight physiological decline during saline test in both groups. In the normal controls and in the parkinsonian patients both ACTH and cortisol levels were significantly higher after naloxone administration than during saline test. However, both naloxone induced ACTH and cortisol responses were significantly higher in normal than in parkinsonian subjects. In agreement with the well-known opioid deficiency characterizing the parkinsonian brain, these data show a reduced opioid inhibitory control of ACTH/cortisol secretion in patients with Parkinson's disease.

Adrenocorticotropic Hormone↗
PubMed1990

Metyrapone effects on beta-endorphin, ACTH and cortisol levels after chronic opiate receptor stimulation in man.

The aim of this study was to evaluate beta-endorphin, ACTH, and cortisol plasma levels during metyrapone administration in man after chronic opioid receptor stimulation. Metyrapone (750 mg every 4 hr for 6 doses) was administered to ten male heroin addicts, who had been on a maintenance therapy with methadone for at least 6 months and to ten healthy sex- and age-matched volunteers. Before metyrapone administration the basal levels of cortisol and ACTH were significantly decreased in addicts as compared to normal controls, while plasma beta-endorphin was not different. The response of beta-endorphin and ACTH to metyrapone administration was significantly blunted in addicts (p less than 0.01). These results suggest that the chronic stimulation of opiate receptors can impair the function of the anterior pituitary gland.

Adrenocorticotropic Hormone↗
PubMed1989

[Chlordesmethyldiazepam and prolactinemia during surgical stress].

The per-operative plasma prolactin levels in 16 male patients undergoing plastic-reconstructive surgery were studied. 8 patients received chlordesmethyldiazepam 0.1 mg/kg-1 i.v. (group C), 8 sodium thiopental 5 mg/kg-1 i.v. (Group T) in anaesthesia induction. All patients were premedicated by diazepam 0.15 mg/kg-1 by mouth 90 min. before anaesthesia induction and atropine 0.007 mg/kg-1 i.v. just before induction, and received succinylcholine 1 mg/kg-1 i.v. and an endotracheal tube for mechanically controlled ventilation. Anaesthesia maintenance was assured by isoflurane 0.5-2.5% in a N2/O2 (2/1) gas mixture. Blood samples were collected from each patient at the following times; 24 h before surgery (t0); 30 min after skin incision (t1); 30 min after extubation (t2). Significant variation of blood prolactin levels are not been shown.

Adult↗
PubMed1988

[Effects of chlordemethyldiazepam on blood cortisol during surgical stress].

The pre-operative plasma cortisol levels in 16 male patients undergoing plastic-reconstructive surgery were studied. 8 patients received chlordesmethyldiazepam 0.1 mg/kg-1 i.v. (group C), 8 sodium thiopental 5 mg/kg-1 i.v. (group T) in anaesthesia induction. All patients were premedicated by diazepam 0.15 mg/kg-1 by mouth 90 min before anaesthesia induction and atropine 0.007 mg/kg-1 i.v. just before induction, and received succinylcholine 1 mg/kg-1 i.v. and an endotracheal tube for mechanically controlled ventilation. Anaesthesia maintenance was assured by isoflurane 0.5-2.5% in a N2O/O2 (2/1) gas mixture. Blood samples were collected from each patient at the following times: 24 h before surgery (t0); 30 min after skin incision (t1); 30 min after extubation (t2). Significant variations of blood cortisol levels have not been shown.

Adult↗
PubMed1986

Basal and glucose- and arginine-stimulated serum concentrations of insulin, C-peptide, and glucagon in hyperthyroid patients.

The effect of oral glucose and arginine infusion on plasma glucose, glucagon, serum insulin, and C-peptide concentrations was evaluated in 16 patients with hyperthyroid Graves' disease and in ten euthyroid age- and sex-matched normal subjects. Basal plasma glucose concentrations were significantly higher in the hyperthyroid patients, but the plasma glucose response following glucose and arginine administration was similar in the two groups. The insulin response was similar in the hyperthyroid and normal subjects after glucose administration and significantly lower during arginine infusion in the hyperthyroid patients. The serum C-peptide response to both glucose and arginine administration was markedly blunted in the hyperthyroid patients, and the plasma glucagon response to arginine infusion was decreased. These results suggest that pancreatic beta and alpha cell secretory function is impaired in hyperthyroidism as assessed by C-peptide and glucagon secretion following oral glucose administration and arginine infusion. The apparent discrepancy between C-peptide and insulin secretion in the hyperthyroid patients following glucose administration might be due to diminished hepatic extraction of insulin or enhanced metabolism of C-peptide.

Adult↗
PubMedDate not supplied

[Alpha-fetoprotein: normal values in amniotic fluid between 14 and 21 weeks].

BACKGROUND: To define the normal values of amniotic fluid alphafetoprotein in pregnant women, whose gestational ages range from 14 to 21 weeks, in the Hospital de Clínicas de Porto Alegre. MATERIAL AND METHOD: One hundred thirty seven women with indication for amniocentesis were studied. The alphafetoprotein was measured in all samples using enzyme immunoassay. One hundred and nine normal pregnancies were selected. All of these fetuses had normal karyotype and had no malformation. They were not twins and their amniotic fluid samples were not bloody. These samples were divided by their gestational ages. Then the medians of the alphafetoprotein values and their multiples were calculated. RESULTS: The medians of alphafetoprotein (KUI/ml) for each gestational age were as follows: 14 weeks: 16.32; 15 weeks: 14.36; 16 weeks: 13.43; 17 weeks: 10.93; 18 weeks: 8.22; 19 weeks: 7.35; 20 weeks: 5.62; 21 weeks: 4.47. CONCLUSION: The establishment of alphafetoprotein normal values in our service allows us to use this assay for patients at risk of neural tube defects. It also makes possible to analyze samples sent for cytogenetic or metabolic studies, in order to identify elevated levels of alphafetoprotein, so that these fetuses could have a more detailed sonography study to look for malformations.

Adult↗