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Biomedical subjects

A Bertoli

Publications and source records attributed to A Bertoli.

At least 55 records · Page 3Linked to original sources
PubMed1988

Treatment of inappropriate secretion of thyrotropin with somatostatin analog SMS 201-995.

Inappropriate thyrotropin secretion (IST) may originate from either neoplastic disease (nIST) or non-neoplastic resistance to thyroid hormone (nnIST). An inhibitory effect of somatostatin on TSH secretion has been documented. In an attempt to elucidate the possible therapeutic effect of this peptide on nIST and nnIST, a study was conducted in 7 such patients. Sandostatin (SMS 201-995) was administered in daily doses of 100 micrograms for several days to 1 month. Four patients with nIST responded with a fall in circulating TSH as well as alpha-subunit with concomitant normalization of free thyroxine and clear symptomatic improvement. In the 3 nnIST patients this effect was considerably less apparent and a partial TSH escape was observed on long-term treatment in 2 cases. The importance of somatostatin and its analogs in the management of thyroid malignancy is stressed.

Antineoplastic Agents↗
PubMed1988

[Preparation of 125I-labelled monoclonal antibodies of the insulin receptor].

Three monoclonal anti-insulin receptor antibodies have been labelled with 125I according to various methods (Cloramine T, Lactoperoxidase and IODO-GEN). The effect of labelling on antibody structure and function has been characterized using the following parameters: a) specific activity obtained in four different labelling procedures, at least; b) TCA labelled antibody precipitable 90 days after labelling; c) interaction between labelled antibodies and the insulin receptor; d) ability of antibodies to inhibit insulin-stimulated receptor auto-phosphorylation. Cloramine T method produced labelled antibody with constant specific activity; however, some preparations were unstable and showed reduced capacity to recognize the insulin receptor. Lactoperoxidase method produced stable antibodies; however, specific activity was highly variable and antibodies had low capacity to interact with the insulin receptor. The IODO-GEN method produced antibodies with constant specific activity, stable, high capacity to interact with the insulin receptor, and, moreover, maintaining in full the capacity to inhibit the insulin-stimulated auto-phosphorylation of the insulin receptor, since it does not induce antibody alterations which in turn affect antibody-receptor interaction biological action.

Antibodies, Monoclonal↗
PubMed1986

Evidence of extragastric gastrin release in postoperative ulcer patients.

The principal sites of gastrin production in man are localized at the level of the gastric antrum; both the oral glucose load and the protein meal stimulate the gastrin secretion. The aim of this study was to verify the gastrin response in patients with gastric resections presented with various stimuli. In the operated patients, the behavior of serum gastrin after a protein meal was different with respect to that observed in control subjects. After glucose, on the contrary, a very similar result was seen when compared to controls. The increase in serum gastrin of patients with Billroth II provides a further confirmation of an extragastric origin of gastrin.

Dietary Proteins↗
PubMed1986

The effect of lysine acetylsalicylate on somatostatin inhibition of insulin secretion induced by arginine.

The inhibitory effect of somatostatin (SRIF) on immunoreactive insulin release and on many other hormonal secretions has been widely studied in both animal and man. However, the mechanism by which SRIF acts on these functions remains poorly defined. Aim of this study is to determine the inhibitory effect of SRIF on insulin secretion induced by arginine after the administration of lysine acetylsalicylate (LAS) in a dose which inhibits the endogenous synthesis of prostaglandins. Ten healthy informed volunteer subjects were studied. Four studies were carried out in randomized order, each one separated by a three day interval. The first study was a test of arginine (25 g i.v. in 30 min). The second study was a test of arginine with SRIF infusion (150 micrograms bolus followed by 100 micrograms/h for 120 min). The third study was a test of arginine with an infusion of SRIF and LAS (66 mg/min for 120 min). The fourth study was a test of arginine with LAS infusion. Plasma insulin levels were determined by radioimmunoassay. After arginine administration the typical biphasic insulin response was observed with a precocious peak at 3 min and a late peak at 30 min. This response is not significantly modified under LAS infusion. With the infusion of SRIF at a dose of 100 micrograms/hr after arginine administration only a very modest insulin response was observed. The addition of LAS does not modify the inhibitory effect of SRIF on insulin secretion induced by arginine. This result demonstrates that the inhibitory action of SRIF on the secretion of insulin is not dependent upon the activation of the endocellular prostaglandin system.

Adult↗
PubMed1986

Stimulatory effect of pentagastrin on growth hormone and prolactin secretion in normal subjects.

Gastrin-like immunoreactive substances have been reported as occurring in both digestive tract tissues and nervous system, including the hypothalamus and the anterior and posterior pituitary. The carboxyterminal tetrapeptide shared by gastrin and cholecystokinin, which represents the bioactive site of both hormones, has been shown to be a secretagogue for insulin and glucagon and it might have a neurotrasmitter function. As small gastrin-like peptides may also play a role in the regulation of anterior pituitary hormones, the present study deals with the in vivo effect of pentagastrin on the release of growth hormone (GH) and prolactin (PRL). Six healthy volunteer males and six healthy volunteer females were studied. All females subjects were in the early follicular phase of the normal menstrual cycle and all subjects were not taking or had been taking any drug known to affect GH or PRL secretion. A continuous intravenous infusion of pentagastrin (1.5 micrograms/kg/h) was administered to all the subjects for a time of 3 hours. In males pentagastrin infusion resulted in a significant increase in GH concentration from basal values (P less than 0.01 at 60 min). In females pentagastrin infusion did not affect GH levels. PRL levels were not affected at all by intravenous pentagastrin infusion both in males and females. The exact understanding of pentagastrin action on GH release awaits further investigation. The different pattern between male and female subjects suggests a sexual hormone influence on the hypothalamic-pituitary sites of action of pentagastrin in vivo. Our data did not confirm a stimulatory effect of pentagastrin on PRL secretion in normal subjects.

Adult↗
PubMed1984

Does secretin control insulin secretion?

The effect of secretin on insulin release has been studied in normal subjects after prestimulation with arginine. In order to make a comparison a pulse of glucose with arginine prestimulation was given. A pulse of 1 U/kg b.w. of secretin provokes a secretion of insulin that is weak and brief compared to that provoked by glucose; thus secretin fails to potentiate arginine-induced insulin secretion. Such a result does not support the hypothesis of secretin as the central hormone in the enteroinsular axis.

Adult↗
PubMed1984

Primary aldosteronism: complete remission after adrenal venography.

A remission of adrenal adenoma producing aldosterone is described as a consequence of adrenal venous catheterization. The patient did not undergo surgery but she was kept on frequent clinical controls. The complete remission of the syndrome is still persisting three years after the incident. Since adrenal insufficiency is described after adrenal venous catheterization, the authors suggest that this procedure is to be restricted to well selected patients. When this incident occurs in pathological glands, a remission of endocrine syndrome may be expected.

Adenoma↗
PubMed1983

[Somatostatin].

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Adenoma, Islet Cell↗
PubMed1981

Somatostatin and insulin infusion in the management of diabetic ketoacidosis.

The effect of low-dose insulin infusion (4.8 U/h) in diabetic ketoacidosis was compared to that of low-dose insulin infusion (4.8 U/h) plus somatostatin (500 microgram/h IV). Treatment with insulin only in 20 patients caused normalization of blood glucose levels within 6 hours and resolution of ketoacidosis within 5 hours. During insulin plus somatostatin infusion in 7 patients, blood glucose levels returned to normal within 4 hours and acidosis was reduced within 3 hours. Correction of acidosis is the most important problem in diabetic ketoacidosis: in the severest cases cardiovascular and cerebral complications may ensue. The data presented show that addition of somatostatin to treatment with low doses of insulin reduces and resolves acidosis in a shorter time while plasma levels of glucagon and GH were concomitantly reduced.

Blood Glucose↗
PubMed1981

Transient effect of glucocorticoids on red blood cell insulin receptors.

The effect of oral administration of dexamethasone or cortisone on circulating red blood cell (RBC) insulin receptors was evaluated in normal males before treatment and 24 h (day 1), 48 h (day 2) and 72 h (day 3) after the commencement of steroid administration. Dexamethasone induced a slight significant decrease of insulin binding (p less than 0.05) on days 1 and 3, whereas cortisone did not. Cortisone, on the other hand, produced transient reduction (i.e. insulin binding lower than mean -2 SD of control values) in six subjects out of eight on days 1, 2 or 3 varying from subject to subject. Binding impairment was due mainly to reduced receptor affinity, even if slight reduction of receptor concentration was detectable. Qualitatively the present data agree that impaired insulin binding is due mainly to reduced receptor affinity; however, the effect of steroids on RBC is not significant and persistent as that on monocytes. The less marked effect of dexamethasone and cortisone on RBC versus monocytes indicates that receptor modifications may be tissue specific.

Cortisone↗
PubMed1981

Changes in insulin receptors during oral contraception.

Combined estrogen/progestagen oral contraceptives (OC) have been reported to be associated with a deterioration of glucose tolerance and a decrease in insulin sensitivity; thus, since it has been suggested that steroids affect insulin receptor properties, the influence of OC on insulin receptors was investigated. The study groups were composed of nine normal menstruating women (controls), nine pill users, and two healthy women on OC for the first time. Insulin receptors on monocytes were evaluated at 7-day intervals during the 28 days between menses. Insulin receptor concentration and/or affinity did not show any variation in pill users during the test period and did not differ from values observed in controls in the luteal phase; consequently, the insulin receptor concentration in pill users is lower than that during the follicular phase or in men. The physiological variation of insulin receptor concentration and the increase of receptor affinity in the midfollicular phase, which characterize the normal menstrual cycle, are therefore abolished by OC. This effect occurs rapidly because it was also evident in the two women on OC for the first time. No difference was observed in fasting blood glucose and serum immunoreactive insulin concentrations between control subjects and pill users. The present data appear to confirm that sex steroids affect the insulin receptor and lend further support to the concept that caution must be used in clinical studies of insulin receptors when women are included. In addition, the results suggest that insulin receptors may play a role in the glucose intolerance and insulin insensitivity which have been described in pill users.

Adult↗