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Biomedical subjects

M Fanciullacci

Publications and source records attributed to M Fanciullacci.

At least 19 recordsLinked to original sources

Plasma changes of calcitonin gene-related peptide and substance P in patients with dialysis headache.

Little is known of mechanism of dialysis headache (DH). As suggested for migraine, a role for neuropeptides has been investigated. Twenty-four patients under haemodialysis were studied. Twelve of them suffered from DH. The remaining patients were headache free. Blood samples for radioimmunoassay of calcitonin gene-related peptide (CGRP) and substance P (SP) were collected from the arteriovenous fistula before and after dialysis treatment. Basal plasma concentrations of CGRP were found to be higher in headache patients. Dialysis significantly decreased CGRP concentrations in both groups. No difference in basal plasma concentrations of SP was observed between groups. At the end of the treatment plasma SP concentrations were reduced in headache-free patients but increased in headache patients. Elevated plasma concentrations of CGRP in patients with DH could represent a biochemical factor contributing to susceptibility to headache. Because of the disputable role of SP in migraine, the significance of the increase of the peptide in plasma during DH remains to be elucidated.

Adult↗

Dopamine involvement in the migraine attack.

Clinical evidence and recent genetic findings seem to indicate an involvement of dopamine in the pathophysiology of the migraine attack. Prodromal symptomatology (mood changes, yawning, drowsiness, food craving), accompanying symptoms (nausea, vomiting, hypotension) and postdromal symptoms (mood changes, drowsiness, tiredness) may be related to dopaminergic activation. The dopaminergic system could also play a role in the headache phase, either by taking part in nociception mechanisms, or by regulating cerebral blood flow. A body of pharmacological findings seems to support this involvement. Migraine patients, between attacks, show a higher responsiveness to acute administration of dopaminergic agents. Apomorphine administration induces in migraineurs more yawns as well other dopaminergic symptoms e.g. nausea, vomiting, dizziness. Migraine has been associated with hypotension and, occasionally, with syncope. Bromocriptine causes severe orthostatic syndrome in migraine patients. Both piribedil and apomorphine markedly increase cerebral blood flow of migraine patients, thus indicating enhanced responsiveness of dopamine receptors which are involved in cerebral blood flow regulation. Interictal dopaminergic hypersensitivity has also been demonstrated by means of neuroendocrine tests. Altered dopaminergic control of prolactin secretion exists in migrainous women. L-deprenyl, a MAO-B inhibitor, is significantly more effective in reducing prolactin levels in migraineurs than in controls. Taken together, these findings support the view that hypersensitivity of peripheral and central dopaminergic receptors is a specific migraine trait. Finally, a high density of lymphocytic D5 receptors has been found in migraine sufferers, thus suggesting their upregulation. Therefore, the hypothesis that dopaminergic activation is a primary pathophysiological component in certain subtypes of migraine, namely those characterised by marked dopaminergic symptomatology, has been advanced. From this perspective, a blockade of dopaminergic hyperresponsive receptors can be considered as a rationale for the therapy of migraine.

Dopamine↗

A case of neurofibromatosis type 1 with an aldosterone-producing adenoma of the adrenal.

Neurofibromatosis type 1 is a phacomatosis. Neurofibromas are the most common tumours associated with the disease, and along with other tumours, make neurofibromatosis type 1 the most common tumour predisposing syndrome in humans. Hypertension may be coincidental, but at least two specific neurofibromatosis related causes must be considered, namely neurofibromatous involvement of the renal artery and pheochromocytoma. We have described the first known case of a patient with neurofibromatosis type 1 who developed hypertension due to an aldosterone-producing adenoma of the adrenal. The question of whether this association was coincidental or due to the tumour predisposition of neurofibromatosis type 1 was debated.

Adenoma↗

Early dysfunction of iris sensory fibres in diabetic patients.

BACKGROUND: The present study was designed to propose transcutaneous electrical nerve stimulation (TENS) of the infratrochlear nerve as a noninvasive test useful in the detection of early iris small nerve fibre dysfunction in patients with diabetes mellitus. METHODS: A total of 32 diabetic patients with no symptoms or signs of diabetic neuropathy were enrolled from a clinical practice. Sixteen of them, 6 women and 10 men, ranging in age from 19 to 53 years, had been affected by IDDM for 13 +/- 2 years. The remainder, 6 women and 10 men, age range 32 to 58 years, were suffering from NIDDM (duration of manifestation 5 +/- 1 years). Twenty-six healthy individuals, 11 women and 15 men, ranging in age from 21 to 47 years, served as controls. Pupil area changes induced by TENS of the infratrochlear nerve were investigated. The electrical stimulus was not painful and consisted of a single square wave pulse of 40 mA intensity and 0.8 ms duration. Measurements were carried out by means of a TV monocular electronic pupillometer. RESULTS: A clear-cut miosis was provoked in controls (p < 0.01 versus basal values 100 sec to 220 sec from stimulation). NIDDM patients also showed a miotic response, but it was slower in onset (p < 0.05 versus basal values 140 sec after stimulation) and shorter (p < 0.01 at 180 sec from stimulation) in duration. No pupillary changes were registered in IDDM patients. CONCLUSIONS: An abnormality of iris sensory nerve fibres in inducing pupillary constriction was detected in both diabetic groups. The differences in the severity of the dysfunction could be related to the differences in duration of the disease among the diabetic patients in the two groups. In conclusion, TENS of the infratrochlear nerve could represent an original noninvasive method in detecting early iris sensory alterations in diabetic patients.

Adult↗

Responsiveness of the trigeminovascular system to nitroglycerine in cluster headache patients.

Nitroglycerine is known to induce a headache attack in cluster headache patients, which is indistinguishable from a spontaneous attack. It has recently been suggested that a release of calcitonin gene-related peptide (CGRP) from peripheral terminals of trigeminal nociceptive neurons, which supply cephalic blood vessels, underlies symptoms of cluster headache. The aim of this study was to investigate whether the provocative action of nitroglycerine in cluster headache is due, at least in part, to activation of the trigeminovascular system. Nineteen subjects suffering from episodic cluster headache participated in the study. Eleven of them were in an active period, whilst the others were in remission at the time of the study. CGRP-like immunoreactivity (CGRP-LI) was measured in blood samples from the extracerebral circulation before and after the sublingual administration of nitroglycerine. Baseline CGRP-LI plasma levels were higher (P < 0.05) in the patients who were in an active period. Only in these patients did nitroglycerine induce an attack, which was preceded by a latent period with a mean duration of 27 +/- 3 min. When compared with the baseline, a significant (P < 0.01) increase in plasma CGRP-LI was detected at the peak of the provoked attack; no such increase was detected during the latent period, or at the onset of the attack. The results of this study suggests that the provocative action of nitroglycerine in cluster headache is due, at least in part, to activation of the trigeminovascular system. This mechanism seems to be slow and unrelated to the well-known rapidly occurring vasodilator effects of the drug. Finally, activation of the trigeminovascular system only occurs in those patients already in an active cluster headache period who also have high basal CGRP-LI plasma levels. This suggests that a hyperactivity of trigeminal nociceptive fibres could make the trigeminovascular system of these patients sensitive to the triggering action of nitroglycerine.

Adult↗

Buspirone, but not sumatriptan, induces miosis in humans: relevance for a serotoninergic pupil control.

BACKGROUND AND OBJECTIVE: Drugs that act on the serotoninergic system have been shown to influence the pupil size. However, the 5-hydroxytryptamine (5-HT) receptor type or subtype that affects pupil diameter has not been defined in humans. With a placebo-controlled, double-blind randomized design, we investigated in healthy volunteers the effect on pupil size of buspirone and sumatriptan, which mainly act on 5-HT1A- and the 5-HT1-like receptors, respectively. METHODS: The pupil area was measured by means of a videopupillometer before and after a single oral administration of placebo or of three different doses of active drugs. Heart rate and arterial blood pressure were recorded after pupil area measurement. RESULTS: Buspirone (5, 10, and 20 mg) caused a dose-dependent miosis. Sumatriptan (50, 100, and 200 mg) did not affect the pupil size. Twenty milligrams of buspirone reduced the mydriasis induced by pretreatment with homatropine eyedrops. A 20 mg dose of buspirone reduced blood pressure without change in heart rate, whereas buspirone, at doses lower than 20 mg, and sumatriptan did not affect heart rate and blood pressure. CONCLUSIONS: This study suggests that buspirone, but not sumatriptan, the selective agonist of 5-HT1-like receptors, causes miosis in humans by activation of 5-HT1A receptors, possibly located in the central nervous system where they inhibit iris sympathetic pathways. Measurement of pupil size seems to provide a valuable and sensitive index of 5-HT1A receptor function in humans.

Administration, Oral↗

Lowered circannual urinary melatonin concentrations in episodic cluster headache.

The circannual secretion of melatonin in 14 Swedish and 15 Italian patients suffering from episodic cluster headache was compared with 14 Swedish and 15 Italian healthy controls matched for sex and age. Overnight samples of urine were collected once a month from 8 to 14 months and kept at -20 degrees C until analysed with RIA. The melatonin concentrations in nocturnal urine were permanently low in cluster headache and there was no consistent change of the melatonin concentration in relation to cluster periods occurring during the study. There was no definitive circannual or infraannual rhythmicity of melatonin in patients or controls. Multiple analysis of variance with repeated measurements showed a significant effect of disease (p < 0.05), but not of time. Sex, geographical location, age, and smoking also had significant effects (p < 0.001) on the melatonin concentrations. Lower melatonin levels in cluster headache patients than in controls may in part be related to a larger number of smokers in the patient group. The relation between tobacco use and melatonin should be further studied.

Adult↗

Urinary melatonin excretion throughout the ovarian cycle in menstrually related migraine.

Nocturnal urinary melatonin excretion was significantly decreased throughout an ovarian cycle in 12 migraine without aura patients compared to 8 healthy controls. Normal increases in urinary melatonin excretion during the luteal phase was less pronounced in the migraine patients. Melatonin excretion was further decreased during headache. The data indicate impaired pineal function in migraine.

Adult↗

Substance P-induced fibrinolysis in the forearm of healthy humans.

Physiological saline with or without substance P (50 ng/ml) was infused into the humeral artery in 6 healthy males. Indices of fibrinolytic activity (whole blood diluted lysis time, euglobulin lysis time, lysis areas in non-heated fibrin plates produced by plasma or euglobulin precipitate, plasminogen plasma levels, alpha 2-macroglobulin, C1-inhibitor, and alpha 2-antiplasmin) were evaluated in the homolateral antecubital vein before and after 5 min of substance P or saline infusion. After substance P the fibrinolytic activity increased, as can be seen from the shortening of lysis times (p < 0.01) and enlargement of the lysis areas (p < 0.01). A reduction of plasminogen plasma levels (p < 0.01), associated with a decrease in alpha 2-antiplasmin (p < 0.01), was also found. Alpha 2-macroglobulin and C1-inhibitor were instead unaltered by the peptide. The saline infusion, on the other hand, was unable to modify any of the examined indices. We concluded that exogenous substance P given intra-arterially increases fibrinolytic activity in locally-sampled venous blood through a mechanism which remains to be elucidated.

Adult↗

Possible long-lasting inhibition of converting enzyme by enalapril in human cerebrospinal fluid.

1. Converting enzyme and neutral endopeptidase activities were both measured every 3 h by a fluorimetric method in plasma and cerebrospinal fluid of patients diagnosed as migraineurs with aura after lumbar puncture, which was performed 9 h after an acute oral dose of enalapril or placebo. 2. A reduced converting enzyme activity, as compared with placebo, was observed in patients who were given enalapril. On the other hand, neutral endopeptidase activity detected after enalapril did not differ from that measured after placebo. 3. The results seem to indicate that enalapril penetrates the blood-brain barrier in sufficient amounts to reduce converting enzyme activity. Moreover, neutral endopeptidase was not affected by enalapril. Therefore, those clinical effects of the drug which have been attributed to the involvement of central opioid mechanisms may depend on the inhibition of brain converting enzyme but not the inhibition of brain neutral endopeptidase.

Adult↗

Long-term ergotamine abuse: effect on adrenergically induced mydriasis.

The mydriatic action of sympathomimetic eyedrops after a therapeutic dose of ergotamine was measured in migraine patients with and without histories of long-term ergotamine abuse. Mydriasis induced by the postsynaptic alpha 1-agonist phenylephrine was similar in both groups of patients tested, whereas pupillary dilation caused by the release of noradrenaline tyramine was markedly greater in patients with histories of ergotamine abuse. The enhanced response to tyramine disappeared after drug withdrawal. These findings indicate that continuous ergotamine medication causes a reversible alterations in iris sympathetic transmission. This manifestation may reflect a central inhibition of pupillary sympathetic activity.

Adult↗

Action of nimodipine on sympathomimetic mydriatics in humans.

In 12 healthy volunteers, the effects of a single oral dose of nimodipine (40 mg) on pupil size and on the mydriasis induced by conjunctival instillation of tyramine and phenylephrine were studied by using a TV monocular infrared pupillometer. Nimodipine alone was unable to modify the pupil area. When compared with placebo, the Ca2+ entry blocker reduced the pupil dilation caused by tyramine, whereas it did not affect the phenylephrine-induced mydriasis. Since tyramine provokes mydriasis by releasing neuronal norepinephrine, a full adrenoceptor agonist, whereas phenylephrine acts only on alpha 1-adrenoceptors insensitive of extracellular Ca2+, the hypothesis may be advanced that a heterogeneous population of alpha-adrenoceptors, located in the human iris dilator muscle and differently sensitive to Ca2+ entry blockade, is responsible for the reduction of the tyramine-induced mydriasis. Apart from this putative mechanism, the results suggest that nimodipine reduces the pupillary response to adrenergic activation in the human eye.

Administration, Oral↗

Kallidin applied to the human nasal mucosa produces algesic response not blocked by capsaicin desensitization.

Various kinins (dissolved in 50 microliters) were applied to the nasal mucosa of healthy human volunteers to test the algesic and proinflammatory effects of these peptides in an intact human tissue. [des-Arg9]-bradykinin (0.5 mumol) was found to be inactive, while bradykinin (0.05-0.5 mumol) and especially kallidin (0.005-0.5 mumol) induced: (a) a mild painful sensation described as burning and pricking (latency 30 s, duration 3-5 min), (b) perception of pulsatility and obstruction in the nasal cavity (onset 1 min, duration 6-8 min). Substance P (0.5 mumol) and neurokinin A (0.5 mumol) produced slight obstruction and weak pulsatile sensation but not pain. Capsaicin (0.05 nmol) produced pain and secretion of fluid, but not pulsatile sensation. The effects of kallidin were not affected by repeated (to induce desensitization) applications of capsaicin (0.5 mumol). Likewise, ipratropium bromide (80 mg in 100 microliters) did not affect responses to kallidin. In an intact human tissue, kallidin produces various effects, including an algesic response, that are apparently independent from activation of B1 receptors and from desensitization of capsaicin-sensitive primary afferents.

Adult↗

Low pH medium induces calcium dependent release of CGRP from sensory nerves of guinea-pig dural venous sinuses.

Low pH medium has been shown to activate the 'efferent' function of capsaicin-sensitive primary sensory neurons. Calcitonin gene-related peptide (CGRP) is released from capsaicin-sensitive afferents of guinea-pig superior sagittal and transverse sinuses (SSTS), by capsaicin or bradykinin. Here, we report that low pH medium produces a remarkable release of CGRP from SSTS, which was dependent on the concentration of hydrogen ions of the medium (pH 7-5). Moreover, the pH 5-evoked release of CGRP-LI was markedly reduced (by about 70%) in a calcium-free medium containing 1 mM EDTA or abolished in samples pre-exposed to 10 microM capsaicin. The present observation that lowering of the pH promotes release of a powerful vasoactive peptide from perivascular capsaicin-sensitive sensory nerves may have some relevance in the pathophysiology of brain injury and migraine headaches.

Animals↗

In vivo pupillary constrictor effects of substance P in man.

The ocular effects of substance P (SP) were studied in 13 normal volunteers. Various concentrations of SP (0.135, 1.35 and 135 micrograms per 100 microliters) were instilled into the conjunctival sac and pupillary area changes were evaluated by means of an electronic pupillometer. The ability of SP to modify the mydriasis induced by pretreatment with 1% homatropine eyedrops was also studied. The instillation of SP produced miosis in a dose-dependent manner without provoking any ocular disturbances. Furthermore, the highest concentration tested was unable to reduce the homatropine-induced mydriasis. These findings indicate that SP exerts a pupillokinetic action in humans which probably occurs via a receptor mechanism. Since muscarinic blockade is not overcome by the peptide instillation, the results do not clarify whether SP causes miosis acting on iris muscles and/or cholinergic fibres.

Adult↗

Evidence for alpha 1-adrenoreceptor hyperresponsiveness in hypotensive cirrhotic patients with ascites.

Cirrhosis with ascites is often characterized by arterial hypotension associated with increased plasma norepinephrine levels. Clinical evidence suggests a decreased sensitivity to norepinephrine in this clinical setting, indicating a potential derangement of alpha 1 adrenoreceptors. The aim of the present study was to evaluate the reactivity of the alpha 1-adrenoreceptor, using phenylephrine, a selective alpha 1 receptor agonist. First, we evaluated the pupillar response to the intraconjunctival administration of the agonist. Hypotensive cirrhotic patients showed a trend to a more marked and prolonged response, compared with age-matched healthy controls. Second, we studied the response of alpha 1-adrenoreceptors in the peripheral vasculature by administering iv phenylephrine to a similar group of patients. A significantly greater and longer lasting pressor response was observed in hypotensive cirrhotic patients (p less than 0.0001 vs. healthy controls). Our results indicate that in this group of patients, there is a rather peculiar situation, characterized by alpha 1-adrenoreceptor hyperresponsiveness in the presence of high levels of circulating norepinephrine. This finding could be related to biochemical abnormalities within the peripheral sympathetic nervous system endings.

Adult↗