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Biomedical subjects

G Rosadini

Publications and source records attributed to G Rosadini.

At least 55 records · Page 3Linked to original sources
PubMed1987

Reduction of cerebral blood flow in subclinical hepatic encephalopathy and its correlation with plasma-free tryptophan.

Cerebral blood flow (CBF), measured by the noninvasive xenon-133 inhalation method, EEG, and plasma levels of ammonia (NH3) and free tryptophan were determined in 18 hospitalized cirrhotic patients affected with subclinical hepatic encephalopathy, as diagnosed by the Kurtz test. CBF results were significantly lower (p less than 0.001) in the patients' group as compared with a sex- and age-matched normal control population, although seven patients had values in the normal range. NH3 was increased only in six, while free tryptophan was increased in all but two patients. A significant negative correlation (p = 0.02) between CBF and free tryptophan was found, even though it appears to be difficult to interpret. We suggest that CBF impairment in some cirrhotic patients with subclinical hepatic encephalopathy may be related to the systemic metabolic derangement caused by the liver disease; free tryptophan could have some implication in producing CBF reduction.

Adult↗
PubMed1987

Effects of scopolamine (0.25-0.75 mg i.m.) on the quantitative EEG and the neuropsychological status of healthy volunteers.

There has been clinical and experimental evidence that cholinergic compounds and precursors of choline are potentially useful in the treatment of dementia. Anticholinergic compounds have also been proposed as a possible acute model for pharmaco-EEG studies focussed on CNS aging. Single doses of scopolamine (0.25-0.75 mg i.m.) and a matching placebo were administered to 8 young healthy volunteers. Quantitative EEG recordings and neuropsychological testing were performed in baseline conditions prior to and 30, 90 and 120 min after drug administration. Scopolamine induced a dose-related increase of relative power in low- and high-frequency components and a decrease in the range 8.0-13.5 Hz and in total signal power. These modifications were found to be limited to the posterior scalp electrode derivations and were observed from the 90-min control onwards. Concomitantly, there was a significant impairment in the subjects' response to neuropsychological testing after the administration of 0.50 and 0.75 mg of scopolamine. At a dose of 0.75 mg, volunteers complained about subjective symptoms which were definitely unpleasant. The effects of this dose on the EEG and the neuropsychological status did not differ significantly from those observed after a dose of 0.50 mg. As regards dose and tolerance, 0.50 mg of scopolamine administered intramuscularly appears to be a suitable dose for pharmaco-EEG studies.

Adult↗
PubMed1986

Pattern of labeling of rabbit cerebral cortex soluble proteins 24 hours after a single electroconvulsive shock.

The labeling of proteins in the particulate subcellular fractions and in the cell sap was studied in the cerebral cortex of rabbits 24 hours after a single electroconvulsive shock (ECS). To this end the animals were injected with [3H]valine subarachnoidally and sacrificed 30 minutes later. The incorporation of the labeled amino acid into proteins was slightly increased in all subcellular fractions but the increase was significant only for soluble proteins. Referring to the type of soluble polypeptides found in the cortex at this post ECS phase, no modification was found in the SDS electrophoresis pattern of steady state proteins. The fractionation pattern of labeled soluble proteins showed in one third (3 out of 9) of the experiments a remarkable stimulation of the synthesis of two polypeptides (25,000 and 54,000 Dalton MW), which were not labeled in the controls.

Animals↗
PubMed1985

Cerebral blood flow in minor cerebral contusion.

Seventeen patients with minor cerebral contusion were selected from a series of patients with head injuries of various severity, who had undergone repeat evaluations of the regional cerebral blood flow. The mean global flow (expressed as mean global initial slope index) on early examination was found to be significantly lower, compared with that recorded in healthy volunteers. A tendency towards the recovery of higher flow values was apparent in repeat evaluations that were performed several weeks after the injury. Interhemispheric asymmetries of flow were a common occurrence, with lower perfusion and reduced attenuation values on computed tomography scans being, however, in good agreement only in approximately half of the cases.

Adolescent↗
PubMed1985

Quantitative EEG and neuropsychological effects of piracetam and of the association piracetam-lecithin in healthy volunteers.

The electroencephalographic (EEG) and neuropsychological effects of single, oral doses or piracetam (800-6,400 mg) and of its association with lecithin (4,800 mg and 25 g, respectively) were investigated in two groups of healthy volunteers in placebo-controlled studies. The EEG was quantified by power spectral analysis; both parametric and nonparametric procedures were applied to process the EEG and neuropsychological data statistically. The drug plasma concentration was assessed (gas chromatography) in concomitance with the EEG and neuropsychological measurements. Piracetam was found to elicit systematic EEG effects, namely a decrease in the low-frequency components and an increase in the power of the 8.5- to 12.0-Hz and of the fast-frequency components. The EEG modifications were restricted to the anterior scalp areas; its detection by means of parametric statistics was conditioned by the relevant individual variability and was inferred resting upon a number of criteria (indication at nonparametric tests, topography, consistency across subjects, replicability, etc). The correlation between EEG changes and drug plasma concentration was ambiguous, and the compound was not found to be effective on any of the neuropsychological variables considered. The study exemplifies some of the methodological problems in quantitative pharmaco-EEG and emphasizes the relevance of topography and replication.

Brain↗
PubMed1984

[Cigarette smoking. A pilot project of dehabituation and experimental research].

An interdisciplinary approach was adopted in a pilot programme research project as the most effective way to obtain concrete results in curing tobacco-addiction. The various stages and effects of the treatment are analysed as a means of identifying the most appropriate techniques. The early results are reported under separate headings according to treatment type (psychological, neurophysiological, dietary, clinical, chemical).

Adult↗
PubMed1984

Comparison between the central effects of camazepam and temazepam. Computerized analysis of sleep recordings.

The effects of acute administration per os of 30 mg camazepam and the same dose of temazepam, were compared with placebo in 8 young male volunteers, fully adapted to the laboratory environment by 6 nights of adaptation. The study was double-blind, in a random order, 10 days separating each session. Spectral analysis was performed on the all-night records (1-min epochs), and the relative power of six frequency bands calculated. Concerning sleep parameters, temazepam induces a statistically significant reduction of: phase shifts; number of awakenings; percent duration of sleep stages I and IV. A significant increase of the percent duration of stage II and sleep efficiency was also found. Camazepam shows modification, with the same trend, but not reaching statistical significance. Concerning spectral analysis, temazepam induces a light increase of the relative power of the slowest frequencies, paralleled by an increase of the fast bands, while major effects are found on the characteristic periodicity of delta activities, which appear disrupted by the drug. These effects are not evident with camazepam, which does not seem to distort the normal sleep pattern.

Adult↗
PubMed1984

Effects of doxefazepam on normal sleep. An EEG and neuropsychological study.

The effects on sleep of a putative hypnotic, benzodiazepine (doxefazepam), were studied in 7 healthy volunteers. Subjects were administered placebo or the active compound at 10-, 20-, and 40-mg oral dose prior to 13 consecutive nights during which they slept in the EEG laboratory. Full-night EEG recordings were obtained, and the hypnogram was determined. The subjective characteristics of sleep (quality, dreams, etc.) were defined by self-administered rating scales; neuropsychological and quantitative waking EEG measurements were performed before drug/placebo administration and in the morning following the final awakening, in order to identify possible signs of 'hangover'. Volunteers thereafter slept at home for 15 nights, self-administering 10 mg doxefazepam each night, and returned to the laboratory for 2 additional full-night sleep recordings. The drug plasma concentration was monitored during the study. Doxefazepam (10 mg) reduced the number of intermediate awakenings and the shifts between distinct sleep phases; single 20- or 40-mg doses or a 2-week administration of 10 mg doxefazepam increased significantly the total sleep duration and the percent duration of the phase 2 and the synchronized sleep and decreased the percent duration of phase 1 and of the intermediate awakenings. Volunteers reported an improvement in the subjective 'quality' of sleep, while evident signs of 'hangover' were not observed. The compound appeared to be of potential use as a sleep regulator.

Adult↗
PubMed1983

Topographic approaches in human quantitative pharmaco-electroencephalography.

The scalp distribution of the quantitative EEG effects of neuroactive compounds was studied in a number of pharmaco-EEG investigations, in which comparable procedures for EEG recording and processing were applied: power spectral and amplitude analyses were combined in all studies. Topographic differentiations were observed. These could include intrahemispheric and/or interhemispheric dissimilarities in the distribution of EEG effects common to the explored electrode derivations, as well as drug effects detectable only in distinct areas. The distribution could vary depending upon the EEG parameter considered; it was restricted to drug-related EEG modifications in all cases.

Anti-Anxiety Agents↗
PubMed1983

Correlates of adaptation to the sleep laboratory. Behavior, sleep organization, quantitative EEG.

The present study aims at establishing to what extent adaptation phenomena should be taken into consideration for the definition of an independent baseline in sleep research. To this purpose we have studied: (1) a standard battery of neuropsychological test evaluating performance, subjective assessments of moods and sleep quality; (2) classical sleep parameters; (3) data derived from quantitative analysis of sleep EEG. 19 young male volunteers have been recorded for consecutive nights; 7 of them underwent the recordings for 3, 8 for 6 and 4 for 10 nights. Results can be summarized as follows: (A) both interindividual and intraindividual variability show a progressively decreasing trend toward homogeneity for most of the explored parameters; (B) steady state is reached in different times for different groups of parameters; (C) an adequate group homogeneity was achieved from the 5th night onwards. Implications of these data in sleep studies, namely in sleep active drug research are discussed.

Adaptation, Psychological↗
PubMed1983

Effects of a single oral dose of phenobarbital on prolactin, growth hormone and luteinizing hormone in normal women.

The effects of a single oral dose of phenobarbital (PB) on the 24 h secretion of prolactin, growth hormone and luteinizing hormone have been evaluated in normal women. An EEG record was taken and barbiturate levels assayed in serum. A statistically significant decrease of growth hormone 24 h mean levels was observed and growth hormone and prolactin values during sleep were diminished. No changes in luteinizing hormone concentrations were observed. After PB the EEG showed no important alterations in sleep pattern, but on the power analysis an increase above 16 Hz absolute power was detected during the waking period.

Administration, Oral↗
PubMed1982

[Statistical study on the medical management of patients with epilepsy in a district of Reggio Calabria].

The epilepsy service provided by 143 doctors in the district of Vibo Valentia (Calabria) which has a population of 180,000 was studied by a team of specially trained medical students. The answers to a questionnaire given in personal interviews were statistically processed and revealed: a) a 3-4% incidence of epilepsy corresponding closely to the national average (Almost all doctors questioned had epileptic patients). b) that only 3% of the doctors tested drug concentration in the blood, while 33% relied on regular EEG checks. c) that Depakin (valproic acid) was the drug most often used, followed by Metinal-Idontoine (phenytoin + barbiturate), Dintoine (phenytoin) and Gardenal (phenobarbital). Almost all doctors were in favour of refresher courses to improve the service to epileptic patients.

Epilepsy↗
PubMed1982

Regional cerebral blood flow: normal values in healthy volunteers obtained by a 32 probes xenon 133 inhalation system.

Regional cerebral blood flow (CBF) was measured in 15 healthy young volunteers in psycho-sensorial rest by the 32 probes Xe133 inhalation system. The mean hemispheric values are in good agreement with those reported in literature and obtained with a limited number of probes. The regional values of the flow in the gray matter are higher in the basal-temporal and frontal regions. This regional pattern is not evident for the other considered parameters (flow in the white matter, mean flow, "weight" of the gray matter).

Adult↗
PubMed1982

Labeling of non poly(A) associated RNA in the rabbit cerebral cortex 24 hours after a single electroconvulsive shock.

The labeling pattern of non poly(A) associated (poly(A)-)RNA of rabbit cerebral cortex was studied 24 hr after a single electroconvulsive shock (ECS). The animals were injected subarachnoidally with [3H]uridine and sacrificed 1 hr later. The fractionation pattern of labeled nuclear poly(A)-RNA in the cerebral cortex of ECS treated animals was identical to that of the controls. However, microsomal poly(A)-RNA from the treated animals showed an increased labeling of 18S ribosomal RNA. Also 28S RNA displayed a higher labeling but the effect was not statistically significant. These results indicate a more efficient production of ribosomal RNA in the late post-ECS period which might be in relationship with an increased activity of brain protein synthesis machinery.

Animals↗
PubMed1982

Effects of acute intravenous administration of met-enkephalin in the rabbit: a computer analysis.

Intravenous administration of doses of Met-enkephalin ranging from 33.3 to 5000 micrograms/kg was followed by modifications in the EEG pattern in the rabbit. The changes were a prevalence of strongly synchronized EEG patterns, lasting about 90 min, in the absence of any behavioural sign of drowsiness. A transient fall in arterial blood pressure, lasting 15 sec, was observed immediately following the injection. Quantification of the EEG effects showed a remarkable increase of EEG total power. Such an increase is statistically significant. It was less marked in the posterior leads and appeared to be dose-related as regards its intensity, duration, and latency from injection. Qualitatively such a spectral profile matches the one typical of physiological drowsiness. As regards EEG effects, no tolerance to the peptide developed if the administration was repeated after 90 min. The specific antagonist of opiates both prevented and reversed the hypersynchronization of the tracing. These findings demonstrate that Met-enkephalin crosses the blood-brain barrier in an amount adequate to producing changes in the functional organization of the brain, resulting in EEG patterns corresponding to functional depression.

Animals↗
PubMed1982

Growth hormone, prolactin and cortisol nyctohemeral variations during naloxone-induced opiate receptor blockade in man.

To evaluate the role of endogenous opioid peptides in prolactin (Prl), growth hormone (GH) and cortisol neuroregulation, 50 mg of the opiate antagonist naloxone was infused over 24 h to 6 normal male volunteers. An additional naloxone dose (5 mg) was given iv as a bolus injection at 20.00 h. blood specimens were collected hourly by means of a portable constant withdrawal pump. Naloxone failed to alter 24 h secretion of GH and Prl. The sleep-related GH and Prl rise was also unaffected by the opiate blocker. Moreover, naloxone failed to alter the circadian rhythm of cortisol and its 24 h concentration. The results do not suggest, a major role of opiate receptors in spontaneous GH, Prl and cortisol secretion in man.

Adult↗