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Biomedical subjects

S Smirne

Publications and source records attributed to S Smirne.

At least 55 records · Page 3Linked to original sources
PubMed1995

Cardiac autonomic function during sleep and wakefulness in multiple sclerosis.

Some studies in multiple sclerosis (MS) patients have shown evidence of autonomic dysfunction involving the cardiovascular system. However, the findings in these studies have not been completely consistent. The discrepancy may be related to the limits of the traditional autonomic tests during wakefulness. In our study, after the investigation of the cardiovascular reflexes during wakefulness, heart rate (HR) variations were considered during sleep in order to avoid the limits of cooperation and the emotional state of the patient. We evaluated tonic (vagal activity) HR modifications in relation to the deepening of sleep, as well as phasic (sympathetic activity) HR modifications in relation to spontaneous body movements during sleep, in 25 MS patients and 25 age-matched controls. No difference was found between the two groups in autonomic function during wakefulness. A reduced parasympathetic activity was observed in MS subjects during both rapid eye movement (REM) and non-REM sleep, while no difference was found in sympathetic function between patients and controls. No significant correlation was found between cardiac autonomic data during sleep and MRI lesion load in the infratentorial areas and, in particular, of the brain stem. The findings of our study suggest that autonomic nervous system evaluation during sleep could show impairment earlier than the traditional autonomic tests during wakefulness.

Adult↗
PubMed1995

Connective tissue proliferation and growth factors in animal models of Duchenne muscular dystrophy.

The difference in the lifespan of dy and mdx mice could be due to different muscle regeneration capabilities. In mdx an involvement of bFGF in stimulating regeneration has been postulated. The aim of our work was to detect the presence, and to study the distribution, of muscular and connective tissue growth factors in mdx and dy mice at different stages of muscle pathology. From 7 to 10 weeks of age the difference between the two dystrophic mice becomes evident. At 13 weeks the dy mouse presents a predominance of fibrosis and degenerative muscular phenomena while the main pathological feature in mdx mouse is the muscle regeneration. In both animal models fibrosis proliferation is correlated to the presence of EGF and its receptor and TGF beta 1. bFGF was localized to regenerating and degenerating fibers in both dy and mdx mice. The bFGF presented a normal pattern in mdx mice at 20 weeks when regenerative and degenerative phenomena were no longer present. Our data suggest that growth factors could influence the outcome of muscular regenerative and degenerative processes.

Animals↗
PubMed1995

Snoring in twins.

Snoring is a prerequisite for obstructive sleep apnoea (OSA) and is known to run in families. Recent studies have provided sufficient evidence for a familial predisposition to OSA. In our study, 492 monozygotic and 284 dizygotic twins were contacted by telephone and asked to attend an interview which included questions of life habits, medical history, sleep habits and disorders, with particular emphasis on snoring. Our study showed that the probandwise concordance rate for habitual snoring was higher in monozygotic twins than in dizygotic ones, but the difference was not significant. The comparison of concordant pairs for habitual snoring vs. concordant pairs for non-snoring confirmed that habitual snoring is significantly associated with older age, male gender, higher body mass index (BMI), smoking and respiratory diseases. The multivariate analysis in the discordant groups confirmed that BMI is more strongly associated to habitual snoring in dizygotic twins than in the monozygotic ones. Our logistic analysis showed that other variables, such as smoking and respiratory diseases, are associated with habitual snoring in dizygotic pairs, but not in monozygotic ones. These findings suggest a genetic predisposition to habitual snoring.

Age Factors↗
PubMed1995

Triazolam and melatonin effects on cardiac autonomic function during sleep.

After benzodiazepine (BDZ) administration, a decrease in cardiac vagal tone has been described during wakefulness, but data on cardiac autonomic function during sleep are lacking. Melatonin (MLT), reported to have hypnotic properties, caused an increase in vagal tone in animals. The aim of this study was to evaluate heart rate (HR) variability during sleep after a single bedtime dose of triazolam (TRI, 0.125 mg) and MLT (100 mg) in six healthy young subjects. We evaluated tonic (vagal activity) HR modifications in relation to sleep as well as phasic (sympathetic activity) HR modifications in relation to spontaneous body movements during rapid-eye-movement (REM) and non-REM (NREM) sleep. No significant change in sympathetic activity was observed after TRI and MLT in comparison with placebo, whereas TRI caused a significant decrease in vagal tone during sleep. Our nocturnal study seems to confirm previous diurnal findings about a decrease in vagal tone by BDZs.

Adult↗
PubMed1995

EEG arousal pattern in habitual snorers with and without obstructive sleep apnoea (OSA).

This study evaluated the arousal pattern and sleep fragmentation in the sleep microstructure of heavy snorers and obstructive sleep apnoea (OSA) patients. Fifteen snorers [Group A, (A + H I) </= 10], 15 mild OSA (Group B, A + H I > 10 </= 30] and 15 moderate to severe OSA (Group C, A + H I > 30) were studied retrospectively analysing the number, duration and type of arousals according to scoring rules concerning definition (including delta bursts) and length (from 2 to 60 s) of phasic arousal events. The number of arousals per hour of sleep related to respiratory events was higher in Groups B and C, whilst in Group A there was a number of arousals not related to apnoea or hypopnoea. Daytime sleepiness, present in all three groups and measured by a subjective evaluation, correlated with both the number and EEG type of arousal, but not with the duration. Statistical analysis indicated that arousal index related to apnoea or hypopnoea was the best variable for determining the sleepiness risk in OSA and snorers. Sleep microstructure analysis seems a good scoring method for the detection of sleep fragmentation and arousals in relation to abnormal respiratory events.

Journal Article↗
PubMed1995

Slow wave sleep and cyclic alternating pattern (CAP) in HIV-infected asymptomatic men.

Alterations of sleep structure have been reported in asymptomatic human immunodeficiency virus (HIV)-infected subjects. In these patients some authors have found an increased percentage of slow wave sleep (SWS) and a SWS preponderance in the second half of the night, as well as subjective sleep complaints. Other authors have found an increased stage 1 non-rapid eye movement (NREM) and reduced stage 2 NREM percentages in asymptomatic subjects. We evaluated the macrostructure and the microstructure (cyclic alternating pattern, CAP) of sleep in nine HIV-infected asymptomatic men without sleep complaints or psychiatric illness, in comparison with nine age-matched controls. Our study showed a decreased amount of SWS and a significantly higher CAP rate in HIV-subjects, suggesting an altered organization of the sleep process in these patients.

Adult↗
PubMed1995

Arousal fluctuations in non-rapid eye movement parasomnias: the role of cyclic alternating pattern as a measure of sleep instability.

Some non-rapid eye movement (NREM) parasomnias, such as sleep-walking (SW), sleep terror (ST) and, in some aspects, sleep enuresis (SE), are considered "arousal disorders" without significant polysomnographic changes in classic sleep macrostructure. The aim of our study was to evaluate sleep microstructure and oscillations of arousal level by cyclic alternating pattern (CAP) scoring in some NREM parasomnias. Nocturnal polysomnography and videotape recording was used to study 21 patients with motor and behavioral phenomena during sleep: 13 in Group A (seven SW, six ST) with delta sleep-related episodes, eight in Group B with other parasomnias (six sleep bruxism and two SE), and six healthy controls. Classic sleep macrostructural parameters were no different in the parasomniacs and controls. Compared with the controls, our patients' sleep microstructure, scored by CAP analysis, showed increases in CAP rate (a measure of NREM instability with high level of arousal oscillation), in number of the CAP cycles, and in arousals with EEG synchronization, the increases being more significant in Group A than in Group B. An increase in sleep instability and in arousal oscillation seems to be a typical microstructural feature of delta sleep-related parasomnias and probably plays a role in triggering abnormal motor episodes during sleep in these patients.

Adolescent↗
PubMed1994

Melatonin and delayed sleep phase syndrome: ambulatory polygraphic evaluation.

The present study objectively evaluated the efficacy of oral 5 mg day-1 melatonin in advancing the sleep-wake rhythm in patients with delayed sleep phase syndrome (DSPS). Six patients underwent ambulatory sleep monitoring for 72 h before and 48 h after 1 month of melatonin treatment. In each patient melatonin was administered on the basis of his own estimated dim light melatonin onset (DLMO) delay. Mean advances in sleep onset time of 115 min and in final awakening hour of 106 min were found after treatment, with no significant changes in sleep architecture parameters. Our study objectively confirms previous data obtained by a sleep-wake subjective diary on the efficacy of melatonin DSPS.

Adolescent↗
PubMed1994

Nocturnal sleep study in multiple sclerosis: correlations with clinical and brain magnetic resonance imaging findings.

It has been suggested that sleep disturbances in multiple sclerosis (MS) may be related to periodic leg movements (PLM) during sleep, but to date polysomnographic studies were conducted only on small and unselected patient groups. Aim of this study was to evaluate 8-hour polysomnography in MS patients and to correlate sleep results with clinical and brain magnetic resonance imaging (MRI) data. Twenty-five clinically definite MS patients, without mood disorders and drug-free, entered the study. The patients were compared to 25 age- and sex-matched subjects. MS patients had significantly reduced sleep efficiency and experienced more awakenings during sleep. No difference was found in sleep architecture parameters between MS patients and controls. PLM was found in 9 patients (36%) and 2 controls (8%; p = 0.02). Of the six patients who complained of insomnia two had PLM and 2 others presented with PLM and central sleep apnea. In patients with PLM greater MRI lesion loads were detected in the infratentorial regions, particularly in cerebellum and brainstem. Larger studies in neurological diseases that produce focal lesions in these brain areas could provide useful information on the PLM pathogenesis.

Adult↗
PubMed1994

Significance of full nocturnal erections with short duration.

The aim of the study was to clarify the pathophysiologic significance of full but short-lived nocturnal erections observed in some impotent men. Penile circulation was assessed by color Doppler sonography and pharmacocavernosometry in 35 impotent patients who underwent polysomnographic recording of nocturnal erections. In each case, there were at least 3 erectile episodes with a complete rigidity (always > 700 g) but with a short duration (mean duration of the maximum level of full erection = 4 min; always < 6 min). All patients demonstrated a normal arterial inflow with mean +/- SEM right and left cavernosal peak flow velocities of 39.5 +/- 1.8 and 41.3 +/- 1.5 cm/s, respectively. Pharmacocavernosometry detected a dysfunction of the cavernous veno-occlusive mechanism (mean +/- SEM maintenance flow: 45 +/- 8 ml/min and mean +/- SEM corporal pressure decay over 30 s: 82.5 +/- 9 mm Hg) in 18 patients (51%). In these patients, this finding may be a possible explanation for the short duration of nocturnal erectile episodes. In the remaining 17 patients (49%) with normal penile vascular status, a dysfunction of the adrenergic system could play a role in the pathophysiology of this picture. Full but short-lived nocturnal erections, as assessed by polysomnographic recording, are indicative of a normal arterial status and should encourage further assessment of the corporal veno-occlusive mechanism.

Adult↗
PubMed1994

Snoring and nocturnal oxygen desaturations in an Italian middle-aged male population. Epidemiologic study with an ambulatory device.

Recent studies have suggested that portable monitoring may be a valid means of finding respiratory disturbances in epidemiologic research on a large scale. The aim of this cross-sectional study was to evaluate by means of an appropriately validated portable instrument (MESAM 4) the nocturnal oxygen desaturations in a representative sample of adult male population in North Italy. We randomly chose 750 subjects: 399 subjects (53.2 percent) agreed to participate and a complete evaluation of nocturnal recording was possible in 349 subjects (87.5 percent). Seventeen percent of subjects were every-night snorers; a number of oxygen desaturations per hour (ODI) > 10 was found in 13.7 percent, and an ODI > 20 resulted in 4.8 percent. Age, neck circumference corrected for height, snoring time (measured by MESAM), and self-reported snoring were the variables best explaining ODI in our multivariate approach. This study reports the highest prevalence, using nocturnal oxygen desaturation indices as marker, of sleep-disordered breathing than any reported until now in a general population.

Analysis of Variance↗
PubMed1993

Ambulatory polysomnography of never-depressed borderline subjects: a high-risk approach to rapid eye movement latency.

The sleep parameters of never-depressed borderline subjects and age- and sex-matched normal controls were compared by continuous 48-hr ambulatory electroencephalographic (EEG) monitoring. Borderline subjects had a significantly shorter rapid eye movement latency, normal architecture of rapid eye movements sleep, and had familial risks for mood disorders four times greater than in the families of controls. Reduced latency of rapid eye movement can be a trait indicator of liability to depression, present before the clinical appearance of the disorder, and demonstrable in a putative high-risk population.

Adult↗
PubMed1993

Habitual snoring and obstructive sleep apnea syndrome in children: effects of early tonsil surgery.

Habitual snoring and obstructive sleep apnea syndrome (OSA) in children are important in determining disturbed sleep, daytime symptoms and haemodynamic modifications. Moreover, chronic snoring is often associated with enlarged tonsils and adenoids. We studied 60 children (mean age 42.2 months) with habitual snoring, defined as a positive answer to the question 'does the child snore every night', by nocturnal or diurnal polysomnography in order to evaluate breathing disorders and choose surgical correction of upper airway stenosis. In more than half the children habitual (every night) snoring begin before the first year of life and is associated with obstructive apneas. Both nocturnal and, with some limits, diurnal recordings may be a good tool for diagnosis of sleep-related upper airway obstruction. Early adenomonotonsillectomy, in mild to moderate form and in children before 4 years of age, and adenotonsillectomy in the others seems to show a clinical and polysomnographic resolution of snoring and OSA during a short-term follow up.

Adenoidectomy↗
PubMed1993

Effect of melatonin on sleep microstructure: preliminary results in healthy subjects.

The ability of melatonin (MLT) to potentiate the effects of gamma-aminobutyric acid and the benzodiazepines has been demonstrated repeatedly in animal models, and recent experimental data favored the hypothesis that MLT, given together with threshold doses of benzodiazepines, could significantly improve the quality of sleep. This preliminary study was designed to compare the effects of MLT (100 mg) with those of a benzodiazepine hypnotic [triazolam (TRI) 0.125 mg] and to explore the effects of a combination of MLT and TRI at a low dose in healthy volunteers. No significant changes in the classical polysomnographic variables were observed following MLT, TRI and MLT + TRI, whereas MLT and especially MLT + TRI resulted in significant modulation of some microstructural parameters. These changes were paralleled by ameliorated subjective sleep quality. A combination of MLT and low benzodiazepine doses could avoid the residual, dose-related benzodiazepine effects.

Adult↗
PubMed1993

Obstructive sleep apnea in the Rubinstein-Taybi syndrome.

The Rubinstein-Taybi syndrome is characterized by a pattern of malformations including broad thumbs and big toes, microcephaly, facial dysmorphism, small stature, and mental retardation. Obstructive sleep apnea (OSA), has been described in several facial or skeletal malformations, but never in the Rubinstein-Taybi syndrome. We studied a 9-year-old boy, previously diagnosed as having the Rubinstein-Taybi syndrome and affected by severe OSA, as documented by polysomnography. He manifested the habitual and heavy snoring with breathing difficulties at night, and excessive daytime sleepiness. Short neck and obesity were important factors for the severity of the syndrome. Continuous positive airway pressure was not tolerated and weight loss was the only possible treatment, as upper airway surgery was not indicated by cephalometric, otolaryngologic or clinical results.

Cephalometry↗