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Biomedical subjects

C Scandellari

Publications and source records attributed to C Scandellari.

At least 19 recordsLinked to original sources
PubMed1994

Effect of endogenous organic hyperinsulinaemia on blood pressure and serum triglycerides.

Hyperinsulinaemia and insulin resistance have been hypothesized to be the common pathophysiological factor of hypertension, NIDDM and obesity. To evaluate the possible role of hyperinsulinaemia and insulin resistance on hypertension, we studied a group of 37 patients with insulinoma who were admitted to our department in the period from 1966 to 1990. We recorded blood pressure and assayed blood glucose, plasma insulin, plasma triglycerides and serum uric acid levels, before and after surgery, in these patients and in a 37-subject control group. No significant increase in blood pressure and triglyceride plasma levels was recorded in the chronic hyperinsulinaemic hypoglycaemic patients, suggesting the lack of a direct role of hyperinsulinaemia on hypertension.

Adult↗
PubMed1992

Assessment of testicular cytology by fine needle aspiration as a diagnostic parameter in the evaluation of the azoospermic subject.

OBJECTIVE: To investigate whether testicular cytology by fine needle aspiration (FNA) may be considered a diagnostic parameter in the evaluation of the azoospermic subject. DESIGN: Cytologic smears were obtained using a 23-G needle, stained with May-Grünwald-Giemsa stain and examined under a light Orthoplan microscope (Wild, Leitz, Germany) for qualitative and quantitative analysis. PATIENTS: Fifty-four azoospermic patients were analyzed, and the findings were compared with those obtained from 40 normozoospermic infertile subjects used as controls. MAIN OUTCOME MEASURE(S): Two hundred spermatogenic cells were counted and classified at the various steps of spermatogenesis. Spermatic index and Sertoli index provided further elucidations and more comprehensible results. RESULTS: No sign of traumatization was observed. Cytologic analysis was proved to have high statistical reproducibility (P less than 0.01 for spermatogonia and secondary spermatocytes and P less than 0.001 for the other cell types, when compared between differential counts) and permitted identification of different situations associated with azoospermia: Sertoli cell-only syndrome, germ depopulation (hypospermatogenesis), spermatogonial arrest, spermatidic arrest, and obstructive azoospermia. These findings agreed with clinical and hormonal parameters and with the results of bilateral surgical biopsies, when performed. CONCLUSIONS: The results support use of FNA of the testis as a noninvasive diagnostic parameter for the assessment of azoospermic subjects.

Adult↗
PubMed1992

Plasma acetyl-carnitine concentrations during and after a muscular exercise test in patients with liver disease.

In many human tissues, fuel is stored for immediate use, as well as for energy exchange between different parts of the body. Fat and glycogen represent, together with proteins, the principal energy storage materials. During energy requirement, e.g. muscular exercise, glycogen as a local reserve, is used first to supply energy needs. Acetyl-carnitine, as an active molecular group, represents an intermediate substrate, usable directly in the working tissue. The present study investigates whether plasma acetyl-carnitine could be a useful biochemical measure for information on fuel exchange in the body, and whether it is a rapidly available energy source exchangeable among tissues with different metabolic functions, such as muscle and liver. The present study investigated control and hepatopathic subjects after maximal and submaximal muscular exercise. Hepatopathic patients may be a useful model, as liver carnitine metabolism is likely to be impaired. Plasma acetyl-carnitine before, during and after maximal exercise in hepatopathic subjects did not differ, while in normal subjects it increased. After submaximal exercise, acetyl-carnitine increased in patients, as well in controls. In the patients (n = 9) with liver metabolism disorders we observed that during maximal exercise plasma acetyl-carnitine varied from 3.26 +/- 2.18 mumol/l (time 0 min) to 4.30 +/- 2.02 mumol/l (time 20 min) and from 1.99 +/- 1.36 mumol/l to 4.83 +/- 2.60 mumol/l (p less than 0.05) in the controls (n = 7).(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcarnitine↗
PubMed1991

Endocrine pancreatic function in pheochromocytoma.

In six patients with pheochromocytoma oral glucose tolerance test (OGTT) and arginine test were carried out. Blood insulin and glucagon response were investigated. In subjects with adrenal tumor glycemic curve pattern was typical: a rapid and exaggerated increase of glycemia followed by an abrupt drop. Absolute insulinemic response to oral glucose was normal, but inappropriate to glycemic stimulus. Arginine infusion provoked a slightly above normal increase in blood glucose and a normal increase in blood glucagon. In three of the patients studied postoperatively, reduced glycemic response to glucose was observed, whereas there were no evident variations in blood insulin and glucagon response. These data suggest that in pheochromocytoma impaired glucose tolerance is partly due to the reduced insulin response to oral glucose load.

Adrenal Gland Neoplasms↗
PubMed1991

The Bayesian approach to evaluation of diagnostic data.

Following review of the basic principles of Bayes' theorem, its application to diagnostic procedures is discussed. It is asserted that Bayes' theorem can be applied to clinical diagnostics, provided that disease prior probabilities can be calculated and it can be assumed that a particular patient and those included in the calculation of prior probabilities represent two samples of the same homogeneous population. Problems associated with both these requirements are briefly reviewed. With the aid of some clinical examples, the usefulness of Bayes' theorem is detailed in: (a) evaluating the information obtained through the results of diagnostic studies, (b) evaluating the level of diagnostic reliability achieved with obtained data and (c) a priori evaluation, i.e. before knowing the result, of what kind of information a test can supply. It is concluded that Bayes' theorem is a powerful tool in the rational control and improvement of diagnostic procedures, if not relevant in the formulation of the diagnosis of a single patient.

Bayes Theorem↗
PubMed1989

Evidence for a dopaminergic involvement in the inhibitory effect of alpha human natriuretic peptide on prolactin in man.

Recently, it has been suggested that Atrial Natriuretic Peptides (ANP), as well as peripheral hormones, may have a role as central neurotransmitters or neuromodulators, and in humans it has been observed that alpha human ANP inhibits prolactin secretion. In this study, on 12 normal adult males, we evaluated the effects of ANP on the prolactin release induced by TRH and by the dopaminergic blocker sulpiride. Alpha-hANP administration was followed by a significant fall of prolactin plasma levels but did not influence TRH-induced prolactin response. Nevertheless, sulpiride-induced prolactin secretion was significantly lower after Alpha-hANP administration than after placebo pre-treatment (p values ranging between 0.01 and 0.001). Our results suggest that in man Alpha-hANP has no direct influence on lactotrope cells in inhibiting prolactin secretion, but seems to involve activation of the hypothalamic dopaminergic system.

Adult↗
PubMed1987

Angiotensin-converting enzyme content of human spermatozoa and its release during capacitation.

In this study, we demonstrated, by using known detergents, the presence of angiotensin-converting enzyme (ACE) within human spermatozoa. We determined that maximal angiotensin-converting activity is expressed by sperm incubated in capacitating conditions, whereas this activity is negligible in saline-incubated spermatozoa. We further demonstrated that not acrosomes but cytoplasmic residues contain ACE. Because follicular fluid provides the necessary conditions for a maximal angiotensin-converting activity and for capacitations' metabolic activation, we hypothesize that ACE may play its physiologic role within the female reproductive tract.

Adult↗
PubMed1987

Reduced calcitonin reserve in young hypogonadic osteoporotic men.

Calcitonin is a potent inhibitor of bone resorption and in both sexes, plasma levels progressively decrease with age: therefore, a relative deficiency of calcitonin may be involved in the pathogenesis of osteoporosis in the elderly. Calcitonin plasma levels of young hypogonadic men with osteoporosis are significantly lower than controls: the hypothesis that the decreased calcitonin plasma levels in the elderly are due to a reduced secretory capacity of the "C" cells of the thyroid gland, related to age, does not explain the low calcitonin plasma levels found in young hypogonadic osteoporotic men. Our hypothesis is that gonadal steroid deficiency may participate in the mechanisms regulating calcitonin secretion. Therefore, we studied ten males affected by hypogonadotropic hypogonadism and ten normal men, of comparable age, as controls: we measured plasma levels of testosterone, 17 beta estradiol, androstenedione and calcitonin, and the response of calcitonin to an i.v. bolus of pentagastrin, a well known "C" cells stimulatory drug. Testosterone and calcitonin plasma levels and the response of calcitonin to pentagastrin were also evaluated after 6 months of replacement therapy with testosterone. Basal levels of testosterone, 17 beta estradiol, androstenedione and calcitonin, and the response of calcitonin to pentagastrin, are significantly lower in our patients than in controls, demonstrating that hypogonadotropic hypogonadic subjects have a lower secretory reserve of calcitonin. After testosterone therapy the basal calcitonin plasma levels and its response to pentagastrin stimulus did not differ from controls, suggesting that gonadal steroids influence the calcitonin secretion and reserve. Our data cannot clarify whether osteoporosis of hypogonadotropic hypogonadic patients is related to androgen or estrogen deficiency; however, they suggest that the mechanisms by which gonadal steroid influence bone metabolism may involve calcitonin secretion.

Adult↗
PubMed1987

Role of gonadal steroids in the serotoninergic control of prolactin secretion in men.

The physiological regulation of PRL secretion seems to involve the central serotonin system, since plasma PRL levels are enhanced by serotoninergic agonists and serotonin re-uptake blockers. The aim of this study was to evaluate whether the influence of oestrogens on PRL is mediated by the hypothalamic serotonin system. The PRL response to fenfluramine, a serotonin agonist that releases the amine and inhibits its re-uptake, was assessed in 10 normal men (aged 18-25 years) and in six castrated men (aged 18-24 years). In both groups, the effect of fenfluramine on PRL secretion was also evaluated on the sixth day after receiving clomiphene citrate, an oestrogen antagonist and partial agonist. In castrated men, fenfluramine administration was also performed on the seventh day after the last dose of testosterone enanthate (200 mg i.m. every 3 weeks for 4 months). Our results demonstrate that in normal men fenfluramine treatment significantly enhances plasma PRL levels, and clomiphene citrate treatment significantly reduces this effect. In castrated men, fenfluramine is also able to enhance PRL secretion but to a lesser extent; after clomiphene citrate treatment the increase of plasma PRL levels induced by fenfluramine rises to the normal range. We therefore suggest that in man oestrogens and aromatizable androgens influence PRL secretion at least in part by involving the activation of the hypothalamic serotonin system.

Adolescent↗
PubMed1987

Plasma carnitine and acetyl-carnitine levels at different times of the day.

An interest in both biochemical and clinical carnitine investigation has recently developed. A more complete and extensive study is obtained if acetyl-carnitine as well as carnitine are investigated. This research, using an improved and simplified method for carnitine and acetyl-carnitine determination in the same sample (1 ml) without radioisotopic tracer use, investigates if there are the same differences in their plasma levels at different times of the day. The sample was eluted in a chromatographic column (55 X 15 mm) containing Sephadex G-25M with phosphate buffer (25 mmol/l, pH 7.4). The fraction containing acetyl and free carnitine was divided and employed separately for two assays. The carnitine assay uses an enzymatic reaction catalyzed by carnitine acetyl-transferase (CAT) and measurements are carried out spectrophotometrically. The calibration curve shows r = 0.987 and sensitivity at 5 mumol/l (reference plasma values: 38 +/- 3 mumol/l in 9 subjects). The acetyl-carnitine assay is carried out concentrating the sample by lyophilization and then measuring the enzymatic coupled reactions catalyzed by CAT, malate dehydrogenase and citrate synthase fluorimetrically. The calibration curve gives r = 0.991 and sensitivity at 1.4 mumol/l (reference plasma values: 2.8 +/- 0.3 mumol/l in 9 subjects). Both assay methods are measured at the end point. The carnitine and acetyl-carnitine measured in the plasma of 6 normal subjects at different times of the day vary respectively from 28 to 37 mumol/l and from 1.1 to 5.2 mumol/l in agreement with plasma free fatty acid (FFA) variation from 230 to 779 microEq/l.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcarnitine↗
PubMed1986

Evidence for serotoninergic system involvement in opioid control of luteinizing hormone secretion in man.

Endogenous opioid peptides tonically inhibit LH by acting on hypothalamic mechanisms which regulate LHRH secretion. Opiates increase hypothalamic serotonin turnover but the involvement of the serotoninergic system in the opioid mechanisms regulating LH secretion in man is not clear at present. This study was designed to evaluate whether the tonic inhibitory effect on LH secretion induced by opiates involves the serotoninergic system. We have studied 10 healthy young men (aged 20-28 years). Five subjects were infused with naloxone (10 mg/h for 3 h) before and 120 min after fenfluramine administration (60 mg orally) on two different occasions. In five other subjects naloxone was infused before and after metergoline pretreatment (8 mg on first and second day and 4 mg on the third day, orally, at 0 time of naloxone infusion). After fenfluramine, naloxone infusion failed to induce any increase in LH plasma levels; metergoline pretreatment significantly enhanced the naloxone-induced LH increase. These data suggest that in man a hypothalamic serotoninergic system may be involved in the opioid mechanisms regulating LH secretion.

Adult↗
PubMed1986

Localization of met-enkephalin on human spermatozoa and evidence for its physiological role.

Pro-opio-melano-cortino-derived peptides have been identified in rat testicular extracts and in human seminal plasma, but their physiological role is still unknown. We report that met-enkephalin is localized on human spermatozoa, by means of an indirect immunofluorescent technique. Furthermore, we demonstrate that a met-enkephalin analog (D-Ala2-Mephe4-Met-(o)-ol-enkephalin, FK 33-824, Sandoz, Basel, Switzerland: DAMME) inhibits in a dose-dependent manner the acrosome reaction induction. The hypothesis of a physiological role of seminal met-enkephalin on human spermatozoa fertilizing ability is briefly discussed.

Acrosome↗
PubMed1985

Effects of pirenzepine on plasma insulin, glucagon and pancreatic polypeptide levels in normal man.

The secretion of various pancreatic hormones (insulin, glucagon and pancreatic polypeptide) is affected to a different extent by the cholinergic system. In 7 healthy subjects the effects of treatment for 1 week with pirenzepine, an anticholinergic drug selective for muscarinic receptors, on basal secretion of these hormones and on that induced by i.v. glucose (IVGTT) and arginine were evaluated. The drug did not reduce basal levels of insulin and glucagon whereas it caused an appreciable reduction in basal pancreatic polypeptide (PP). The responses of insulin and blood glucose to IVGTT and to arginine were not changed by treatment, nor was that of plasma glucagon to arginine. The infusion of arginine did induce an increase in PP level, which reached a statistically significant maximum at 90 min. This response was not particularly different after administration of pirenzepine. Thus, the results confirm the finding that arginine stimulates PP secretion in vivo and that pirenzepine reduces the basal level of the hormone, whereas it did not appear to affect the response to arginine. The findings exclude any direct action of the drug on insulin or glucagon secretion or on glucose metabolism in general.

Adult↗
PubMed1985

Testosterone and calcitonin plasma levels in hypogonadal osteoporotic young men.

The aim of this study was to ascertain whether there was an interrelationship between male osteoporosis, calcitonin and androgens. Ten young hypogonadal osteoporotic men were studied: testosterone and calcitonin plasma levels were measured before and after therapy with testosterone enanthate (200 mg im every three weeks for four months). In these patients testosterone and calcitonin plasma levels were significantly lower than controls, before therapy (p less than 0.001 and p less than 0.01 respectively). Testosterone treatment significantly increased (p less than 0.05) serum calcitonin. The conclusion was that androgen deficiency may cause osteoporosis also by decreasing calcitonin secretion.

Adult↗
PubMed1985

Lack of effect of im diazepam administration on hGH and hPRL secretion in normal and acromegalic subjects.

The usefulness of diazepam as a provocative stimulus for hGH secretion has been suggested as a simple, reliable test in clinical hGH assessment of pituitary disorders. We have investigated the effects of diazepam (10 mg im) on plasma hGH and hPRL in 5 normal and 7 acromegalic subjects. No significant variations in hGH and hPRL levels have been observed in any of the studied subjects. These findings indicate that the drug is ineffective on hGH and hPRL release and that it cannot be considered a valid provocative test either in normal or acromegalic subjects.

Acromegaly↗