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Biomedical subjects

P Galli

Publications and source records attributed to P Galli.

14 recordsLinked to original sources

Metal uptake in neurone cultures: a systematic study.

We present the first comparative study of the uptake of metal ions by neurons, performed for Zn, Cr, Co, Mo, Al, Ni, Mn and Cd. The study reveals substantial differences in the uptake of different metals, under similar exposure procedures. In particular, we found very large uptakes for aluminium and molybdenum. We also found significant effects of excitatory substances, in particular kainate, as stimulants of uptake of some of the metals.

Animals

Beta-adrenoceptor desensitization in a model of experimental asthma in guinea-pigs.

We investigated the possible occurrence of the desensitization of pulmonary beta-receptors in a model of experimental asthma such as the ovalbumin sensitized guinea-pig. Although some differences were observed between normal and asthmatic guinea-pigs, the desensitization procedure (isoproterenol (ISO) 10(-6) M x 20 min x 2) markedly impaired the relaxing capacity of ISO, epinephrine (EPI) and procaterol. With the beta 2 agonist procaterol, the sensitized tissues seemed to be more sensitive compared to normal. In parallel, the desensitization procedure produced a greater decrease in the relaxing capacity of procaterol in the sensitized tracheas. On the other hand, the two unselective beta-agonists (ISO and EPI) did not seem to discriminate between the two experimental conditions used. These data suggest that the immunological disturbance due to the active sensitization may induce a modification in beta-adrenoceptor reactivity. The results obtained with EPI after anaphylactic challenge are in agreement with this. In fact, the relaxing capacity of EPI was markedly reduced by antigen challenge.

Adrenergic beta-Agonists

Adrenergic supersensitivity of the pupil in idiopathic headache.

In idiopathic headache (IH) sufferers, phenylephrine and fenfluramine induce a pupillary dilatation respectively greater and lesser than in controls. The difference may be due to a supersensitivity of the iris alpha adrenoceptors caused by a deficiency of noradrenaline in the iris adrenergic nerve terminal of the IH sufferer. These findings seem to support the hypothesis of a brain receptorial, monoamine supersensitivity in IH.

Adult

[Progress of clinical pharmacology in essential headaches].

By testing venomotor receptors (venous-constriction test), it was possible to show a potentiation of the venous constriction effect of serotonin by methysergide and ergotamine. This 5-HT potentiation was observed only when these drugs were sampled in concentrations similar to those in therapeutic use. When ergotamine and methysergide are sampled in concentrations higher than those used in clinical practice, the expected 5-HT antagonist effect is clearly evident. We could therefore conclude that methysergide and ergotamine can be considered pro-serotonin and not anti-serotonin drugs. The pro-serotonin effect of methysergide and ergotamine might take place peripherally on vasomotor or sensitive receptors and/or at a CNS level, making up for the lack of serotonin which, according to the central theory of essential headache, provokes the painful cephalic syndrome.

5-Hydroxytryptophan

Prekallikein and kallikrein inhibitor in liver cirrhosis and hepatitis.

Plasma prekallikrein (kallikreinogen) and kallikrein inhibitor, assayed with the kaolin activable esterase method, have been evaluated in 20 patients with hepatic cirrhosis, in 12 cases with jaundice from acute viral hepatitis, and in 9 normal. A significant reduction of the plasma prekallikrein in cirrhosis has been found. A lowering of plasma prekallikrein has also been observed in viral hepatitis; in this condition, however, the modifications were less important than those obtained in cirrhosis. In three cases of hepatitis, the behaviour of the plasma prekallikrein and kallikrein inhibitor have been controlled during the period of the disease and compared with the behaviour of some conventional parameters, such as serum transaminases and bilirubin. An important increase of the prekallikrein level has been observed during the improvement of hepatitis. These data confirm the implication of the prekallikrein-kallikrein system in severe liver diseases, and indirectly points out the role of the liver in maintaining the physiological balance of the kallikrein system.

Adult

Clinical and animal pharmacology of migraine: new perspectives.

Animal and clinical pharmacological studies show in certain vascular beds a biphasic action [potentiation and inhibition of serotonin (5-HT) responses] of some anti-migraine drugs, such as ergotamine, methysergide and more recently Org GC 94. Potentiation occurs at therapeutic drug concentrations. The present investigations seem to support the 5-HT theory of migraine and other essential headaches. In this theory, anti-migraine drugs, such as ergotamine, methysergide, pizotifen, and Org GC 94 could reduce the occurrence of pain in migraine and other esscutial headaches by acting as partial agonists tending to correct a deficiency of central 5-HT concentrations or turnover.

Animals

5-Hydroxytryptamine and pain modulation in man: a clinical pharmacological approach with tryptophan and parachlorophenylalanine.

Monoamines are involved in the central nervous assimilation and modulation of the pain flow. According to a personal hypothesis, a disorder of this biochemical control (in particular a precariousness of brain 5-hydroxytryptamine turnover), is the basic mechanism of some painful conditions, such as migraine and other essential headaches. Acute (infusion) and chronic (ingestion) administration of tryptophan to migraine-headache sufferers improved the clinical course significantly in respect to placebo. Few patients with untractable pain from disseminated cancer received daily infusion of tryptophan and ingested a few gr of this amnioacid: improvement of pain and reduction of morphine necessity was observed. Parachlorophenylalanine chronic administration in migraine-headache sufferers lowered the pain threshold so far as to provoke (in 20% of cases) spontaneous pains in the trunk, legs and arms. This systemic pain syndrome was promptly reversible by discontinuing the treatment. Spontaneous pain syndrome was not reported by others in the healthy subject; this suggests an apparent vulnerability of 5HT turnover in essential headaches.

5-Hydroxytryptophan

Treatment of cryptorchidism by intramuscular administration of LHRH.

Ten prepubertal boys, aged 6-12 years, presenting with unilateral or bilateral cryptorchidism were treated with a single i.m. injection of 100 micrograms of synthetic LHRH. In addition to the clinical effect, pituitary responsiveness was studied. Immunoreactive FSH and LH in serum were measured by radioimmunoassay. One week after the treatment a complete descent of testes occurred in the four oldest patients. In another four patients, a clear-cut improvement in their condition was seen, and, in two patients, no effect was observed. In nine patients, a significant (p less than 0.001) rise in serum FSH and LH levels was observed. In one patient, serum gonadotropin levels remained unchanged. There was no correlation between the clinical effect and pituitary responsiveness. It was concluded that i.m. administration of LHRH offers advantages over the paranasal route since the dose required for a good effect appears to be considerably lower.

Age Factors