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Biomedical subjects

C Ferrari

Publications and source records attributed to C Ferrari.

At least 289 records · Page 16Linked to original sources

Effects of chronic prazosin treatment on the renin-angiotensin-aldosterone system in man.

The effects of chronic prazosin treatment (3 mg/day for three weeks) on plasma renin activity (PRA) and plasma aldosterone (PA) levels were evaluated in 12 hypertensive patients, under conditions of metabolic balance. After three weeks of drug administration no significant change occurred in PRA as well as PA levels, with respect to pretreatment values, both in basal conditions and following 2 hours of ambulation. No change was observed in heart rate, while a fall in both systolic (P less than 0.02) and diastolic (P less than 0.05) blood pressure occurred in supine as well as in deambulation-stimulating condition. A mild increase in body weight (P less than 0.05) and a decrease in serum sodium (P less than 0.05) was induced by prazosin treatment. These findings are in keeping with the pharmacologic properties of prazosin, which is a selective blocker of postsynaptic alpha adrenoreceptors and therefore lowers vascular resistance without reflex sympathetic overactivity. The moderate volume expansion after prazosin does not appear to be aldosterone mediated.

Adult↗

Meningiomas. A light and electron microscopy study.

A morphological and ultrastructural study was undertaken from a personal series of meningiomas. Especially the fine structure of the tumour has been described by the electron microscopic study of 16 meningotheliomatous and 4 fibroblastic meningiomas. In all cases, it was possible to distinguish certain cells with epithelial features such as desmosomes, microfilaments and interdigitating extensions. Also the cytological patterns of fibroblastic meningiomas usually were similar to the meningotheliomatous type, anyhow the intercellular space between the interdigitating extensions of adjacent cells was occupied by collagen-fibers. At present, it has been impossible to demonstrate the capability of the tumour cells to synthetize collagen. Since the tumour cells of both the meningiomas are substantially similar to the subarachnoid space meningocyte, it is concluded that the neoplasm rises from a cell with double potentiality for fibroblastic and epithelial differentiation.

Female↗

Effect of loperamide, a peripheral opiate agonist, on circulating glucose, free fatty acids, insulin, C-peptide and pituitary hormones in healthy man.

The effect of acute oral administration of loperamide (4, 8 and 16 mg), a peripheral opiate agonist used in the treatment of diarrhoea, on several metabolic and endocrine variables has been evaluated in healthy volunteers in comparison with placebo. Plasma glucose was significantly raised by all three doses, whereas serum IRI and C-peptide were decreased and serum FFA was significantly increased only after loperamide 8 and 16 mg; serum PRL, GH, LH and FSH did not change. The data suggest that opiates may be involved in the regulation of glycaemia, probably by modifying islet hormone secretion by acting at a peripheral site, since loperamide does not cross the blood-brain barrier. Although the precise mechanism of these actions is unknown, it is suggested that the effects of loperamide are mediated either by stimulation of opiate receptors per se, or by suppression of acetylcholine release from cholinergic nerve endings. The lack of change in pituitary hormone secretion by loperamide is in agreement with previous observations indicating that opiate effects on PRL, GH and gonadotropins occur at the level of the central nervous system.

Adult↗

Oral glucose tolerance and insulin response after one week's clonidine treatment in hypertensive patients.

Acute clonidine administration is known to induce a significant rise in plasma glucose in man. In order to evaluate the possible effect of prolonged drug treatment on glucose metabolism, paired OGTTs were performed in 12 hypertensive patients (6 with normal and 6 with abnormal glucose tolerance) in basal conditions and following 1-week's administration of clonidine (0.15 mg every 8 h) Basal plasma glucose and serum insulin concentration as well as glucose tolerance and insulin response to oral glucose did not change in either group after treatment. Although the mechanism(s) mediating the transient hyperglycemic action of clonidine are not fully understood, the present findings indicate that this drug does not exert diabetogenic effects during chronic treatment, and suggest that homeostatic mechanisms may counteract the acute effect of clonidine on glucose metabolism.

Adult↗

Inhibition of the renin-angiotensin-aldosterone system by L-dopa with and without inhibition of extracerebral dopa decarboxylase in man.

1. The present study was undertaken to investigate the possibility that central nervous system mono-aminergic pathways may play a role in the control of the renin-angiotensin-aldosterone system in man. 2. Eight normal subjects received in a randomized order placebo, L-dopa (500 mg, orally) and L-dopa (100 mg, orally) plus carbidopa (35 mg, orally) after pretreatment with carbidopa (50 mg every 6 h for four doses). 3. L-Dopa administration elicited a significant fall in plasma renin activity (PRA) (P less than 0.01 at 120, 150 and 180 min) and in plasma aldosterone levels (P less than 0.05 at 90, 120, 150 and 180 min); L-dopa plus carbidopa induced a decrease in PRA (P less than 0.05 at 120 and 150 min, P less than 0.01 at 180 min) and in plasma aldosterone concentration (P less than 0.05 at 30 and 60 min, P less than 0.01 at 90 and 120 min), in comparison with placebo administration; between-drugs analysis revealed no difference in the decreases in PRA and plasma aldosterone levels induced by the two regimens. 4. Since L-dopa, as well as L-dopa plus carbidopa, has been shown to augment catecholamine levels in the brain of various animal species, the present data suggest that in man PRA and plasma aldosterone concentration might be inhibited by increased central nervous system catecholamine levels.

Adult↗

Serum Gastrin concentration in patients with rheumatoid arthritis: effect of long-term immunosuppressive or antidopaminergic treatment.

In an attempt to further evaluate the conflicting incidence of hypergastrinemia in patients with rheumatoid arthritis (RA), serum gastrin concentration has been determined in 58 RA patients and in 58 healthy subjects. Mean levels were significantly higher in RA patients than in controls, although clearly high values were only found in 3 subjects with severe hypochloridria. During one year of immunosuppressive treatment in 12 RA patients with cyclophosphamide plus colchicine serum gastrin levels did not change, while a significant decrease was observed in another 12 patients after 2 months' treatment with haloperidol, a dopamine receptor blocker; this decrease was sustained throughout the one year treatment. Indomethacin administration up to 6 months did not change serum levels in a control group of 12 RA patients. Serum gastrin concentration in patients treated with haloperidol was significantly lower than in those treated with indomethacin at 2 and 6 months, while no significant differences were observed between cyclophosphamide- and indomethacin-treated groups. These results confirm and extend previous studies showing inhibition of gastrin secretion by antidopaminergic drugs. No correlations were observed between serum gastrin levels and inflammatory indices, both in basal conditions and during any drug treatment.

Adult↗

Darier's keratosis follicularis: an ultrastructural study during and after topical treatment with retinoic acid alone or in combination with 5-fluorouracil.

An ointment containing 0.05% retinoic acid (RA) was applied to the anterior surface of the chest in a patient suffering from Darier's keratosis follicularis. A mixture of two ointments containing equal amounts of 5% 5-fluorouracil (5-FU) and 0.05% RA was used on the dorsum of the same patient. Biopsies were taken 30 days and 70 days after treatment started. Retinoic acid gave rise to an initial disorganisation of desmosomes; the "corps ronds" and "grains" disappeared, the lacunae gradually decreased in size, and the epidermis was practically normal when the clinical manifestations of the skin had disappeared. The damage induced with the RA + 5-FU mixture was more serious, but when the skin lesions relapsed they did so later and in a less severe way than the recurrences observed after treatment with RA alone.

Darier Disease↗

Fine structure of granular cell tumor of Abrikosov.

The case report illustrates the microscopical and ultrastructural findings obtained in a case of Abrikossoff's tumor. On the basis of the light and ultrastructural data a neural histogenesis is suggested.

Adult↗

Effect of loperamide and naloxone on gastric acid secretion in healthy man.

The effect of acute oral administration of three different doses (4, 8, and 16 mg) of loperamide, a peripheral opiate agonist, on basal and submaximal pentagastrin-stimulated gastric acid secretion was evaluated in healthy volunteers. Both basal and stimulated gastric secretion were significantly lowered by 8 and 16 mg of the drug in comparison with a control study, while 4 mg was ineffective. Naloxone, a specific opiate antagonist, decreased slightly but not significantly both basal and pentagastrin-stimulated gastric acid secretion, when infused intravenously at the rate of 30 micrograms/kg/h, but completely abolished the inhibitory effect of loperamide on gastric acidity. These data also suggest that opiates may be involved in the regulation of gastric acid secretion in man by acting at a peripheral site, as loperamide does not cross the blood-brain barrier.

Adult↗

Central nervous system and pituitary mechanisms in dopaminergic stimulation of growth hormone release in women.

In an attempt to evaluate the relative importance of brain and peripheral (i.e., outside the blood-brain barrier) dopamine (DA) receptor stimulation in the regulation of GH release, DA (5 microgram/kg/min infused i.v. for 120 min), L-dopa (500 mg p.o.), L-dopa (100 mg p.o.) plus carbidopa (35 mg p.o.) after pretreatment with carbidopa (50 mg p.o. every 6 h for 1 day), and nomifensine (200 mg p.o.) have been administered to healthy women. Significant elevations in serum GH were induced by all regimens in comparison with a control placebo study, although the effect of DA was only transient in spite of continuing infusion. The between drugs analysis revealed that L-dopa alone was significantly more effective in releasing GH than carbidopa plus L-dopa as well as DA infusion and nomifensine administration. These results suggest that both central nervous system and peripheral mechanisms are involved in dopaminergic stimulation of GH release in man. Since DA does not affect somatotropes directly, increased serum GH levels by DA infusion probably reflect stimulation of median eminence dopaminergic neurons.

Adolescent↗

Inhibition of luteinizing hormone release by dopamine infusion in healthy women and in various pathophysiological conditions.

To investigate the effect of dopaminergic stimulation on gonadotrophin release, serum LH and FSH concentrations were measured during dopamine infusion (5 microgram/kg/min for 120 min) in 8 healthy women in the early follicular phase, in 12 patients with hyperprolactinaemic amenorrhoea, in 5 subjects with premature ovarian failure and in 8 with polycystic ovarian disease and raised serum LH levels. Dopamine infusion produced a significant LH decrease compared with a control study using saline in all groups; there were no significant changes in FSH concentration. Between groups analysis showed a significantly greater LH fall in patients with polycystic ovarian disease than in the other groups. Dopamine inhibits LH release in healthy women and patients with anovulatory states of varying aetiology, and enhanced sensitivity to this inhibitory mechanism exists in polycystic ovarian disease. This finding suggests reduced dopamine activity at the median eminence level in this condition.

Adolescent↗

Spontaneous and induced pregnancies in hyperprolactinemic women.

Sixty-nine pregnancies were observed in 57 hyperprolactinemic women (5 with pituitary macroadenoma, 20 with microadenoma, and 32 with normal tomography of the sella turcica). Ten of these pregnancies took place spontaneously in women with mild to moderate hyperprolactinemia (up to 70 ng/ml); 2 were induced by exogenous gonadotropins, 2 by clomiphene, 42 by bromocriptine, and 9 by metergoline; and 4 occurred after pituitary selective adenomectomy. The observed complications included spontaneous abortion (10 cases); headache (7 cases); sellar enlargement (5 cases); and bitemporal hemianopsia (1 subject with macroadenoma). Among 24 women in whom prolactin levels were reevaluated at least 1 month after parturition and/or lactation, 8 showed a decrease in prolactin concentration (less than 50% of pregestational levels), with actual prolactin normalization in 3 and resumption of cyclic menses in 2 previously amenorrheic women. In contrast, no changes in prolactin levels occurred after pregnancies that ended in abortion. These data suggest the following: 1) conception is not uncommon in women with moderate hyperprolactinemia; and 2) pregnancy may be safely induced without prior surgery and/or radiotherapy in hyperprolactinemic women, except those with large pituitary adenomas, and a considerable number of these patients even show a clinical and biochemical improvement after pregnancy.

Adenoma↗

[Non-A, non-B hepatitis. Seroimmunological, epidemiological and clinical findings].

The characteristics of a third type of viral hepatitis, defined as non-A, non-B are analysed on the basis of the most recent reported findings. The problems of identification of the aetiological agent, its transmisibility in animals, the carrier condition, its possible evolution into chronic and fulminating forms, the effectiveness of immune globulin prophylaxis and epidemiological and clinical aspects are discussed. Reference is then made to the results of an epidemiological study of 293 patients with acute viral hepatitis, admitted to the Infectious Diseases Division of Parma Hospital. Diagnosis of non-A, non-B hepatitis was formulated, by exclusion, in 64 cases (21.8%). Intragroup studies pointed to an intermediate period of incubation and clinico-biochemical picture between A and B hepatitis the possible non-parenteral contagion route and possibilities of recurrence and development into chronic forms. Further information on hepatitis or on non-A, non-B hepatitis, can be provided by screenings based on antigen C demonstration (AgHC).

Acute Disease↗

[Torsion of normal adnexa uteri in the prepuberal age. Description of a case].

A case of torsion of the normal left-hand appendage in a girl of 7 yrs associated with sacral ectopia of the left kidney is reported. The aetiopathogenesis, symptomatology and problems involved in reaching precise preoperative diagnosis are considered and stress laid on the importance of early operation for the purpose of conserving the ovary and tube from resection.

Adnexal Diseases↗