Search PubMed⌕ Search

Biomedical subjects

G Micieli

Publications and source records attributed to G Micieli.

At least 73 records · Page 4Linked to original sources
PubMed1991

Cluster headache. Recent developments in clinical characterization and pathogenesis.

The preliminary results of some new studies on cluster headache (CH) point to: (a) the existence of a form, secondary episodic CH, which should be included in the classification of headache; (b) the significant role played by air temperature variations and the number of daylight hours on the onset of CH active periods. Data from the evaluation of pupil response to corneal stimuli suggest a widespread alteration of the pain/autonomic integrative processes at the level of the central nervous system. Finally, data on new preventive (i.e., verapamil and ozone) and symptomatic (i.e., hyperbaric oxygen and sumatriptan) treatments are reported.

Autonomic Nervous System↗
PubMed1990

Double blind comparison of lithium and verapamil in cluster headache prophylaxis.

Chronic Cluster Headache (CCH) treatment is troublesome; since there are no pain-free periods, it must be continuous. The most effective CCH prophylactic drug today is lithium carbonate but long-term use of this drug is limited by the possibility of side effects. Recently, calcium antagonists have been successfully employed to prevent migraine, and preliminary studies also indicate that verapamil in particular is an efficacious treatment for CCH. We have conducted a multicenter trial employing a double-dummy, double blind, cross-over protocol, comparing verapamil with the established efficacy of lithium carbonate, in preventing CCH attacks. Both lithium carbonate and verapamil were effective in preventing CCH but verapamil caused fewer side effects and had a shorter latency period. We did not observe any correlation between plasma levels of the two drugs and their clinical efficacy. Both the drugs tested here may exert their effect by restoring a normal inhibitory tone to the pain modulating pathways from the trigemino-vascular system, a circuit putatively implicated in CCH.

Adult↗
PubMed1990

[Lipoprotein (a) [Lp(a)] and ischemic cardiopathy: correlation between radial immunodiffusion (RID) and radioimmunoassay methods (RIA)].

The anomalous lipemic values are considered as a risk factor in coronarial pathology. We are separately studying different lipemic factors, Lp(a) in the present paper. May be our 38 clinical cases are still a too small number to demonstrate any correlation between Lp(a) haematic content and arterial pathology, and we will continue this study in the evolution of the pathology, eventually until the infarctus. For the moment, we established the significance of correlation between two methods in two laboratories of ours (in Pavia, Italy, and in Lisboa, Portugal). Correlation is more than 0.9. Assays were done on the same air mailed samples.

Coronary Disease↗
PubMed1990

Dynamic evaluation by TV-pupillometry of the mydriatic effect of ibopamine solution. Controlled studies.

The aim of the study was to evaluate in man the dose-effect relationship of ibopamine solution 0.25%, 0.50% and 1% on the pupillary diameter and the pupillary reflex to light stimulus and near vision. A cross-over study was performed in comparison with a placebo and with tropicamide solution 1% in 18 healthy volunteers. The results show that ibopamine 1% determines a marked mydriatic effect. At the doses used, it produces a maximum increase of the pupillary diameter with a dose-effect relationship which does not depart significantly from a straight line. The maximum mydriatic effect of ibopamine 1% is significantly greater than that of tropicamide 1%. The mydriatic effect of ibopamine lasts for about 3 h; that of tropicamide lasts longer. Tropicamide 1% markedly and for a long period inhibits the pupillary reflex both to light and to near vision. The effect of ibopamine 1% on the pupillary reflex to near vision is slight, while on the reflex to light stimulus it is essentially comparable to that of tropicamide.

Adolescent↗
PubMed1990

Pupillometry and radioreceptor binding. Semeiologic suggestions in the evaluation of the treatment with anticholinergic drugs.

In this study, a dynamic TV pupillometric system has been used to record the effects of the anticholinergic drug biperidene (Akineton) on pupil responsiveness to various types of stimuli. Plasma levels of the drug were evaluated by means of the radioreceptor binding technique at the same times of pupillometric monitoring. An excellent correlation was found between the effects of biperidene on pupil diameter after light and dark adaptation, light reflex and near vision reaction and the plasma levels of the drug. Radioreceptor binding and dynamic TV pupillometry represent useful tools to evaluate the possible alterations induced by drug therapy on the cholinergic system in man.

Adult↗
PubMed1989

Chronic paroxysmal hemicrania: a chronobiological study (case report).

In this study the 24-h pattern of blood pressure (BP), heart rate (HR), plasma catecholamine (CA), beta-endorphin (beta-EP), beta-lipotropin (beta-LPH) and RIII threshold was investigated in a patient suffering from chronic paroxysmal hemicrania (CPH). The investigation was carried out before and during indomethacin therapy in order to assess the presence or otherwise of a disordered biorhythmic organization resembling that documented in cluster headache (CH). A severe alteration in the majority of the rhythms explored was found not only during the drug-free phase, but also in the indomethacin phase of the investigation. These data are similar to those obtained in CH studies and point to the possibility of a common pathophysiological mechanism.

Adult↗
PubMed1989

A study of the cardiopressor effects of lisuride in the treatment of parkinsonism and pathological aging brain.

In this study, the hemodynamic and neurochemical effects of lisuride, a dopamine agonist with serotoninergic properties, have been evaluated in de novo parkinsonian patients and in elderly subjects with mild cognitive impairment. Blood pressure (BP), heart rate (HR), and urinary catecholamine (CA) fluctuations throughout the 24-h cycle were monitored before and during lisuride therapy along with BP, HR, and plasma CA responses to the tilt-table test. Lisuride (1.2-2.4 mg/day) administered in an open-type 15-day study was capable of decreasing the urinary CA excretion and norepinephrine plasma levels in parkinsonian patients. In some cases, the cardiovascular response to standing was impaired. Lower doses of the drug (0.15 mg/day), administered to elderly patients in a double-blind parallel group vs. placebo study, did not induce any change in cardiopressor responses but decreased the 24-h urinary excretion of epinephrine. These results suggest the importance in both conditions of detecting early stages of alterations in cardiopressor homeostatic processes before therapy with DAergic drugs is initiated.

Aged↗
PubMed1988

Neuroendocrine evaluation of central opiate activity in primary headache disorders.

The evaluation of central opiate activity could be of clinical value in the diagnosis and treatment of pain syndromes. The current approach via direct measurement of endogenous opioid peptides in cerebrospinal fluid (CSF) is not devoid of side effects and cannot be used in every-day practice. As an alternative to this method, we have studied the neuroendocrine response of plasma LH to an i.v. naloxone injection in 39 headache sufferers from different diagnostic subgroups, and in 12 age- and sex-matched healthy volunteers. Patients (19 females and 20 males) were affected by common migraine (CM, 11 cases), migraine with interparoxysmal headache (MIH, 9), classical migraine (CIM, 9), and chronic cluster headache (CH, 10). Headache lasted 3-36 years. Prior to naloxone challenge (4 mg i.v.), LH pulsatility was evaluated for 1 h. The next morning, the pituitary response to LH-RH (10 micrograms i.v.) was tested in 20 patients. Plasma LH was measured by RIA in every sample. The response to the tests was evaluated as secretion area of plasma LH minus the mean basal value. Controls (497.5 +/- 85.5 mIU/ml x 120 min), ClM (357.8 +/- 78.9) and CH (450.5 +/- 70.4) patients showed similar results, while in cases of CM (155.3 +/- 71.7, P less than 0.05) and MIH (104.1 +/- 53.7, P less than 0.01) the LH secretion after naloxone injection was significantly blunted. On the contrary, the response of LH to LH-RH was similar in controls and patient groups, thus excluding pituitary dysfunctions in this response.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Cluster headache in women: clinical findings and relationship with reproductive life.

Cluster headache (CH) occurs rarely among women; for this reason only a limited number of studies have been reported on the characteristics of the disease in the female population. In this study, 82 females (age range, 14-72 years) with episodic (69 cases) or chronic (13 cases) CH were investigated. The clinical features of headache and the physiologic events related to reproductive life were compared with those of various control groups. We did not find any remarkable differences in clinical features between men and women. Unlike other forms of primary headache, the course of CH does not seem to be modified by menstruation, pregnancy, or puerperium. Finally, our data seem to confirm a hypofertility trend, mostly after onset of CH, which had previously been noticed by other authors.

Adolescent↗
PubMed1988

Pupil responsiveness in cluster headache: a dynamic TV pupillometric evaluation.

In this study the variations in pupil diameter induced by different stimuli (dark-light adaptation, light reflex, electric stimulation of the sural nerve) were investigated in episodic (in the active or remission phases) and in chronic cluster headache (CH) patients. Pupil size monitoring was performed with a monocular, infrared TV pupillometer, and sural nerve stimuli were applied after the pain threshold had been measured as the flexion reflex threshold of the biceps femoris muscle (RIII reflex). The results were compared with those obtained in patients with "peripheral" (third neuron) Horner's syndrome and in healthy sex- and age-matched controls. On the symptomatic side we found an impairment of pupil response to light flashes and nociceptive stimuli; similar findings were sometimes evident on the pain-free side, too. These results substantiate previous observations that in cluster headache a dysfunction of the integrative central nervous system pathways also exists intercritically and mostly bilaterally, involving both autonomic regulation and pain perception mechanisms.

Adult↗
PubMed1988

Chronobiological variations of prolactin (PRL) in chronic renal failure (CRF).

During a 24-hour period, the serum levels of prolactin (PRL) were determined in 89 subjects, including 24 controls and 65 with chronic renal failure (CRF), divided into groups according to sex, age and serum creatinine. In mild CRF, both in males and females, PRL level proved to be higher than controls while its circadian rhythm of secretion disappeared. The MANOVA analysis (multivariate analysis of variance) showed that all 3 considered factors (sex, age, creatinine) have a systematic effect on PRL values, that of creatinine being the most prominent. With the progression of renal failure, the physiological PRL oscillations tended to diminish. In general, increasing creatinine levels progressively shifted the acrophase (that is the time-distance between a given hour and the maximum peak of the function) to the morning, with hemodialysis patients showing acrophases between 12 p.m. and 1 a.m. It is possible that in CRF the PRL feedback system could no longer function.

Adolescent↗
PubMed1987

Postprandial and orthostatic hypotension in Parkinson's disease.

In this study, the 24-hour pattern of blood pressure (BP), heart rate, and urinary catecholamine (CA) excretion and the response of BP and plasma CA to the tilt test have been investigated in 13 untreated patients affected by Parkinson's disease (PD) and in 11 age-matched healthy controls. Seven of the 13 PD subjects showed a fall of supine systolic BP greater than that in controls (ie, exceeding 20% of the preprandial value). A significant relationship was found in the PD group between the degree of postprandial hypotension and the 24-hour mean value of dopamine excretion. Eight PD subjects also showed orthostatic hypotension during the tilt test (performed in the morning hours) and in the postprandial phase. Basal norepinephrine plasma levels of PD patients, as well as their percentage increases on standing, were within the range of the controls. These data suggest the existence of a subtype of PD patient, characterized by a widespread impairment of cardiovascular responsiveness and bordering on syndromes of autonomic failure such as progressive autonomic failure or multiple system atrophy, or both.

Aged↗