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Biomedical subjects

S Valenti

Publications and source records attributed to S Valenti.

At least 55 records · Page 3Linked to original sources
PubMed1994

A cross-over study with the two novel dopaminergic drugs cabergoline and quinagolide in hyperprolactinemic patients.

Cabergoline and quinagolide, two new dopamine agonist drugs with long-lasting activity, are currently under investigation for the treatment of hyperprolactinemia. At present, studies comparing these drugs for tolerability and efficacy in the same patients are lacking. It was our aim to make such a comparison in an open randomized cross-over trial. Cabergoline (0.5 mg twice weekly) and quinagolide (75 micrograms once daily) were given orally. Each drug was administered for 12 weeks. Treatment with the second drug was started after the recurrence of hyperprolactinemia. Twelve women with hyperprolactinemia due to idiopathic disease (n = 6), microprolactinoma (n = 5) or postsurgical empty sella (n = 1) were evaluated. Six women were amenorrheic and 6 were oligomenorrheic. Ten had spontaneous or provoked galactorrhea. Baseline characteristics (age, clinical signs and PRL levels) of patients initially allocated to the two treatment groups were similar. Nine patients completed both treatment cycles and PRL levels were lower under cabergoline (10.7 +/- 3.7 micrograms/L) than under quinagolide (25.0 +/- 7.7 micrograms/L; p < 0.05). One patient discontinued cabergoline because of dryness of the eyes after having completed the quinagolide cycle and 2 patients initially treated with cabergoline discontinued quinagolide because of gastrointestinal symptoms. After completion of the first treatment cycle, the time of recurrence of hyperprolactinemia was significantly longer after cabergoline (14 +/- 7 weeks) than after quinagolide (5 +/- 1 weeks; p < 0.05). At week 12, normal PRL levels (< 20 micrograms/L) were observed in 10 and 6 women during cabergoline and quinagolide, respectively. Only one case was resistant to both drugs. The clinical effects of the two treatments were similar.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1993

Delta sleep-inducing peptide administration does not influence growth hormone and prolactin secretion in normal women.

The aim of this study was to analyze the effects of delta sleep-inducing peptide (DSIP) on growth hormone (GH) and prolactin (PRL) secretion in eight healthy women with normal cycles (aged 17-36 years). GH and PRL secretion was studied in five women after DSIP (25 micrograms/kg bw IV over 30 min), arginine chlorhydrate (0.5 g/kg bw IV over 30 min) and simultaneous DSIP plus arginine chlorhydrate administration. In three other women the circadian rhythm of GH and PRL was studied during DSIP (25 micrograms/kg bw from 2130h to 2230h) and placebo IV infusion. Serum GH and PRL levels were normal under basal conditions and no effects were noted after the infusion of DSIP. The GH and PRL circadian rhythm was not modified by DSIP administration. DSIP did not influence GH and PRL responsiveness to arginine chlorhydrate. We found that at dosages which are known to modify ECG patterns, DSIP is unable to modify spontaneous or arginine chlorhydrate-induced GH and PRL secretion.

Adolescent↗
PubMed1993

Predeposit hemodilution and intra- and post-operative blood salvage in the orthopaedic surgery of brain damaged children.

The advantages of autologous transfusion are nowadays well known. It appears so very important to enlarge to the greatest number of kinds of pathologies, trying to overcome all possible problems and studying every counterindication. In this study, through a strict collaboration among orthopaedics, anaesthesia, transfusion medicine, neurological and pediatric specialists, we studied a peculiar protocol, suitable for enlarging the autologous techniques to brain damaged children and, after a regular application lasted globally for about two years, we did an evaluation of the results.

Adolescent↗
PubMed1992

Differential lung ventilation with a double-lumen tracheostomy tube in unilateral refractory atelectasis.

Two patients with refractory hypoxemia due to unilateral lung atelectasis were treated with differential lung ventilation (DLV) through a Robertshaw-type, double-lumen tracheostomy tube. DLV was applied using two non-synchronized ventilators and maintained for 6 and 3 days, respectively. Ventilator settings were chosen in accord to the clinical, laboratory and chest X-rays results. Particularly, tidal volume and PEEP were set to avoid excessively high alveolar pressure and to obtain the highest possible value of compliance. We investigated the mechanical properties of the two lungs separately by measuring airway pressure and compliance of each lung before the beginning of DLV and at 0, 5, 24, and 48 h after. Initially we observed in both patients very low values of compliance (7-9 cm H2O/l) and a significant level of PEEPi (12-8 cm H2O) of the diseased lung, whereas PEEPi in the healthy lung was negligible. The clinical improvement was assessed by sequential chest X-rays and by significant improvement of arterial blood gas and PaO2/FiO2 ratios and was associated with a progressive increase of compliance (24-22 cm H2O/l) and by a fall of PEEPi levels (5-4 cm H2O) of the diseased lung. We also observed an improvement of SvO2, O2AVI, PVRI and Qva/Qt values (Case 1). The tracheostomy tube used to apply DLV was very reliable, allowing easy nursing care and selective bronchial aspirations. We conclude that DLV is a very useful technique in unilateral lung pathology, and it can be a life saving procedure in selected patients, by supplying volume and PEEP more efficiently to the affected lung.

Aged↗
PubMed1992

Effect of cholinergic tone on growth hormone-releasing hormone-induced secretion of growth hormone in normal aging.

Aging is associated with an impairment in the GH response to GHRH and to several other stimuli of GH secretion. We evaluated the effect of pyridostigmine (PD) or placebo pretreatment (Protocol A: placebo or 120 mg PD orally at 8 a.m.; Protocol B: placebo or 60 mg PD twice orally at 9 p.m. and 7 a.m.) on GH responsiveness to GHRH (1 micrograms/kg BW bolus i.v. at 9 a.m.) in 15 normal elderly males (65-92 years) and in 14 normal young adults (20-37 years). GH response to GHRH was significantly reduced in elderly subjects compared to young adults (p < 0.05). PD (Protocol A) increased GH release in both elderly and young subjects. In elderly men, PD enhanced GH response to GHRH. The phenomenon was more evident when PD was administered according to Protocol B (p < 0.01). The area under the curve of GH was significantly greater after PD plus GHRH than it was after placebo plus GHRH (p < 0.01). In young adults, PD induced an increase in GH responsiveness to GHRH when administered according to Protocol A (p < 0.05) but not Protocol B. Both GH peak and AUC of GH after PD plus GHRH (Protocols A and B) in elderly subjects were not significantly different from the same parameters found in young subjects after placebo plus GHRH. Our data confirm that pituitary somatotrophin responsiveness to GHRH in man changes with aging. PD restores GH responsiveness to GHRH in elderly subjects. The effect of PD on GH secretion suggests that cholinergic mechanisms may be involved in GH control in normal aging.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Delayed puberty in uremia: pituitary-gonadal function during short-term pulsatile luteinizing hormone-releasing hormone administration.

Pubertal development is frequently delayed or disordered in children with chronic renal failure. Both neuroendocrine and peripheral alterations due to uremia have been hypothesized to explain the impairment in the pituitary gonadal axis. The aim of the present study was to evaluate quantitative (immunological) and qualitative (biological) LH secretion, as well as FSH and sex steroids, before and during 7 days of sc LHRH administration (136-150 ng/kg bw every 120 min) in 5 uremic children (13.1-14.8 yr) with delayed puberty. Six nonuremic children (13.2-17.8 yr) with delayed puberty underwent the same schedule and served as control group. On day 0 mean immunoreactive LH (I-LH) levels were higher in uremic (4.5 +/- 0.9 mIU/ml) than in nonuremic (1.9 +/- 03 mIU/ml; p < 0.05) subjects while no differences were observed in bioactive LH (B-LH) levels (2.9 +/- 0.7 mIU/ml vs 2.4 +/- 0.3 mIU/ml). In both groups of subjects testosterone was at prepubertal levels. Spontaneous I-LH and B-LH pulses were observed sporadically in both uremic and nonuremic subjects. Short-term pulsatile LHRH administration induced significant increases in B-LH, I-LH, FSH and testosterone. The B/I LH ratio increased from day 0 (0.7 +/- 0.2) to day 7 (1.3 +/- 0.4; p < 0.05) in uremics while it showed wide fluctuations in nonuremic subjects. On day 7, 4 uremic and 5 nonuremic subjects showed a pulsatile release of B-LH after exogenous LHRH pulses. Our data document that in uremia there are qualitative as well as quantitative abnormalities in pituitary gonadal secretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Therapeutic strategies in a male with delayed puberty.

Therapeutical strategies in male with delayed puberty. Delayed puberty (absence of pubertal modifications after 14-15 years of age) due to transitory deficit of LHRH secretion often constitutes a difficult differential diagnostic problem for conditions of permanent LHRH deficit which can be identified only after 18 years of age in the idiopathic hypogonadotropic hypogonadism. After a period of clinical observation short-term therapy with pulsatile LHRH administration may take place. Therapy can be necessary: to document the functional integrity of the pituitary-gonadal axis; to promote pubertal modification such as to improve and physiologically sustain the patient; to tray a neuroendocrine activation of endogenous LHRH-LH secretion. Also delayed puberty linked to uremia seems to respond to short-term pulsatile LHRH administration. Pulsatile LHRH administration is the most physiological therapeutical approach to subject with delayed puberty. It seems to constitute a valid alternative to the therapy with testosterone or gonadotropins.

Adolescent↗
PubMed1992

Interaction between thiopentone and subhypnotic doses of ketamine.

The hypnotic effects of thiopentone and ketamine were studied in ASA Grade I female patients aged 20-30 without premedication. The dose-response curves of ketamine 0.4 mg kg-1 and thiopentone following ketamine 0.4 mg kg-1 were determined by probit analysis. The interaction between ketamine and thiopentone was found to be an antagonistic one. This effect can be interpreted as a consequence of the different neurophysiological spectra of action of the two drugs.

Adult↗
PubMed1991

Growth hormone secretion in aging. Effect of pyridostigmine on growth hormone responsiveness to growth hormone-releasing hormone.

Recent studies in adults have shown that cholinergic enhancement by pyridostigmine (PD) has a stimulatory effect on growth hormone (GH) response to GH-releasing hormone (GHRH). PD probably reduces somatostatin release from the hypothalamus by increasing the central cholinergic tone. The aim of this study was to evaluate the effect of PD (120 mg orally) or placebo pretreatment on GH responsiveness to GHRH (1 micrograms/kg b.w. i.v.) or placebo in 10 normal elderly males (68-92 years). PD induced a significant increase in GH secretion (GH peak 7.3 +/- 1.8 micrograms/L, mean +/- SEM) over the basal value (0.9 +/- 0.2 micrograms/L; P less than 0.01) and enhanced GH response to GHRH (peak after GHRH: 17.0 +/- 3.8 micrograms/L; after PD plus GHRH: 42.6 +/- 12.2 micrograms/L; P less than 0.05). There was a significant difference in the secretory areas of GH among tests (P less than 0.05). The secretory area was greater after PD plus GHRH (2722 +/- 801 micrograms/L/120 min) than after GHRH (1185 +/- 206 micrograms/L 120 min; P less than 0.01). The effect of PD on GH secretion suggests that cholinergic mechanisms may be involved in GH control in normal aging. During the life-span cholinergic neurons and/or the somatostatin pathways could exert a differential effect on GH control.

Aged↗
PubMed1989

[Effectiveness and tolerance of a new molecule with secreto-dynamic activity: nesosteine].

232 patients with acute or chronic respiratory disorders characterized by increased secretion, were included in an open multicentre trial to evaluate the tolerability and the activity of a new molecule with secreto-dynamic action, nesosteine. The drug was administered orally at the dose of 900 mg/day for two consecutive weeks. The incidence of side effects (11.6%) was comparable to that observed in studies carried out on molecules with similar activity. Undesirable reactions were found mainly at the gastrointestinal level. Side effects were slight/moderate in most cases; only 3 patients abandoned treatment. Nesosteine therapeutic activity was highly valid; cough and expectorate were favourably affected by treatment. The drug, by restoring the natural characteristics of excreate viscoelasticity, favored a better mucociliary clearance and a more incisive cough expelling action. The activity/tolerability ratio was judged excellent/good by the investigator in 83% of the patients treated.

Adult↗
PubMed1989

Italian multicenter study on the treatment of chronic obstructive lung disease with bromhexine. A double-blind placebo-controlled trial.

237 out-patients suffering from chronic obstructive lung disease (COLD) were selected from 7 Italian clinical centers. They were randomly allocated to either placebo or bromhexine 30 mg b.i.d. p.o., in a double-blind fashion. Sputum volume and quality, facility of expectoration, cough, dyspnea, auscultatory thoracic symptoms, forced expiratory volume, peak expiratory flow rate and residual volume were evaluated. Bromhexine showed a statistically significant therapeutic activity in comparison to placebo. This action was rapid, marked and effective in determining a modulation of bronchial secretions.

Adult↗
PubMed1987

Electrophysiologic effects of cigarette smoking in patients with and without chronic beta-blocker therapy.

After refraining from smoking for at least 8 hours, 22 adult male habitual smokers underwent baseline electrophysiologic study including atrial and ventricular burst pacing and programmed premature stimulation with single extrastimuli. After smoking 2 of their usual brand of cigarettes in rapid succession, the electrophysiologic protocol was repeated. Nicotine, catecholamine and carbon monoxide concentrations all increased significantly. Smoking increased heart rate and improved atrioventricular conduction in the 13 patients receiving chronic beta-blocker therapy (mostly for angina pectoris); increases in heart rate and improvement in atrioventricular conduction were not different statistically from those seen in patients not receiving beta-blocker therapy, suggesting the possibility of a direct effect of nicotine or other components of tobacco smoke. Ventricular refractoriness was not altered and atrial and ventricular arrhythmias were not increased by smoking. Persistent sympathomimetic actions of cigarette smoking may explain in part the failure of beta-blocking drugs to reduce cardiac mortality risk in smokers after myocardial infarction.

Adrenergic beta-Antagonists↗
PubMed1987

Bioavailability and pharmacokinetics of a new controlled-release theophylline preparation in the form of capsules containing pellets.

The bioavailability and pharmacokinetics of a new controlled-release theophylline preparation in the form of capsules containing pellets of coated drug were studied in 10 healthy subjects. Results showed that the bioavailability of this preparation is complete after oral intake of a single dose, while after repeated administrations (300 mg b.i.d.) theophylline serum levels are constantly within the therapeutic range (10-15 mg/l) with small fluctuations over 12 h. Side effects were not observed.

Administration, Oral↗