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Biomedical subjects

G Nolfe

Publications and source records attributed to G Nolfe.

At least 19 recordsLinked to original sources
PubMed1995

Levosulpiride: a review of its clinical use in psychiatry.

Levosulpiride is the (-)-enantiomer of sulpiride. It has shown greater central antidopaminergic activity, antiemetic and antidyspeptic effects and lower acute toxicity than both the racemic and dextro forms. Several clinical studies indicate that levosulpiride has therapeutic efficacy in depressive and somatoform disorders, as well as in schizophrenic patients with predominant negative features. All controlled studies report a low frequency of extrapyramidal and autonomic side-effects. The increase of plasma prolactin concentration is the major drawback of the use of the drug, but its frequency may be reduced by low dosage.

Administration, Oral↗
PubMed1992

Finger tremor and the central nervous system.

It is well known that normal physiological tremor of the fingers and alpha rhythm in the EEG, may share a common frequency band in the region of 10 Hz; that these two characteristics may be in some way related as a function of their frequencies, is a hypothesis which needs to be tested, as one element in establishing the physiology of physiological tremor. Bilateral occipital EEGs and simultaneous measurements of acceleration from the terminal phalanx of the middle finger of both hands were recorded from eight subjects. The data were analysed to produce power spectral densities and coherence functions, the latter being used to reveal the presence or absence of frequency elements common to both signals. No evidence was found that would support a hypothesis that the two characteristics were in any way frequency related, from which it can be inferred that the tremor is not under central control. In addition, tremor of the right and left hands does not show a synchronous relationship.

Brain↗
PubMed1992

Temporal relationship between melatonin and cortisol responses to nighttime physical stress in humans.

It has been shown that, in the rat, physical stress decreases pineal melatonin levels at night, whereas it increases melatonin production during the day. We have demonstrated that nighttime physical exercise is able to blunt the nocturnal surge of plasma melatonin in healthy subjects. Since this effect might be mediated by exercise-induced cortisol secretion from the adrenal gland, in the present investigation we studied the relationship between cortisol and melatonin responses to nighttime physical stress in six healthy men, aged 28-33 yr. The physical stress consisted of bicycling on a bicycle ergometer at 50% of personal maximum work capacity (MWC), followed by another 10 min of bicycling at 80% of MWC. According to our previous data, physical exercise performed between 2240 h and 2300 h significantly reduced the nocturnal surge of plasma melatonin and increased the levels of cortisol. The surge in plasma cortisol preceded the decrease in plasma melatonin concentration. These findings suggest a temporal relationship between plasma cortisol and melatonin responses to physical stress; the causal nature of this relationship remains to be elucidated.

Adult↗
PubMed1992

Controlled study on the therapeutic efficacy of propionyl-L-carnitine in patients with congestive heart failure.

A double-blind phase II study of propionyl-L-carnitine (CAS 17298-37-2) versus placebo was carried out on a group of 60 patients with mild to moderate (II and III NYHA class) congestive heart failure. The group was made up of men and women aged between 48 and 73 years in chronic treatment with digitalis and diuretics for at least 3 months and who still displayed symptoms. Thirty of these patients were chosen randomly and for 180 days, 500 mg of propionyl-L-carnitine was orally administered, 3 times a day in addition to their usual treatment. At basal conditions and after 30, 90 and 180 days the maximum exercise time was evaluated using an exercise tolerance test performed on an ergometer bicycle and the left ventricular ejection fraction was tested by means of bidimensional echocardiography. After one month of treatment, the patients treated with propionyl-L-carnitine, compared to the control group, showed significant increases in the values of both tests, increases which became even more evident after 90 and 180 days. At the stated times the increases in the maximum exercise time were 16.4%, 22.9%, and 25.9%, respectively. The ventricular ejection fraction increased by 8.4%, 11.6% and 13.6%, respectively. On the basis of these results, having studied the particular mechanism of action of propionyl-L-carnitine the authors conclude that it represents a drug of undoubted therapeutic interest in patients with congestive heart failure, in whom it could be efficaciously administered along with a standard pharmacological therapy.

Aged↗
PubMed1992

[The clinical and hemodynamic effects of propionyl-L-carnitine in the treatment of congestive heart failure].

In order to evaluate the clinical and hemodynamic effects of propionyl-L-carnitine (PLC) a randomized, double-blind study versus placebo was performed in 50 patients of both sexes, between 48 and 69 years of age, affected by mild-moderate congestive heart failure. All patients participating in said study were on digitalis and diuretic treatment. 25 of these belonged to the control group, while the other 25 were treated with an oral dose of 1 g b.i.d of propionyl-L-carnitine. At the end of six months of treatment maximum exercise time on the treadmill increased 11.1% after 90 days and 16.4% after 180 in the group treated with PLC. From a hemodynamic standpoint, after 30, 90 and 180 days the ejection fraction increased by 7.3%, 10.7% and 12.1%. At the same time, moreover, the systemic vascular resistances were reduced by 14.9%, 20% and 20.6%. In the patients treated with placebo, however, the above-mentioned parameters showed no significant variation. Finally, no unexpected events or toxic effects were observed in any of the patients in either group. As a consequence of these results it is possible to affirm that propionyl-L-carnitine, due to its clinical and hemodynamic effects, represents a drug of notable therapeutic interest in patients with congestive heart failure, in whom it may be usefully combined with the usual pharmacological therapy.

Aged↗
PubMed1992

Evaluation of the therapeutic efficacy and tolerability of levocarnitine propionyl in the treatment of chronic obstructive arteriopathies of the lower extremities: a multicentre controlled study vs. placebo.

The treatment of symptomatic chronic obstructive peripheral arteriopathies is a difficult task since it requires the prolonged administration of drugs which are often unable to correct the various pathogenetic factors reponsible for the disability. The authors, on the basis of recent studies demonstrating the rheological and vasoactive as well as metabolic activities of levocarnitine propionyl, have decided to use this substance in the treatment of arteriopathics affected by intermittent claudication. Levocarnitine propionyl administered orally to 142 arteriopathics affected by intermittent claudication was responsible for a marked increase in initial as well as absolute walking distances. It is particularly important to note that these clinical results were obtained primarily due to the metabolic activities of levocarnitine propionyl.

Administration, Oral↗
PubMed1991

Evoked potentials in shoe-workers with minimal polyneuropathy.

The aim of the present research was to investigate early impairments of central nervous system in subjects exposed to a low toxic level of industrial solvents for several years. Therefore a group of fifteen shoe-workers, with symptoms of minimal polyneuropathy, and a group of twenty, sex and age matched, healthy volunteers were selected for multimodal evoked potentials studies. The statistical analysis revealed a decrease of VEP and SEP amplitudes as well as a significant higher percentage of cases with BAEP V/I ratio between 0.5 and 1 among patients. The wrist-Erb's point conduction velocity was, also, found lowered in them. In accordance with the experimental results, the systematic employment of multimodal evoked potentials is proposed for screening the subjects exposed to neurotoxic influence of industrial solvents.

Adolescent↗
PubMed1991

Rheological activity of propionyl L-carnitine.

The authors have evaluated the efficacy of chronic administration of propionyl l-carnitine versus Buflomedil chlorhydrate in patients affected by vasculopathies. Patients were divided into two groups, A (n = 14) and B (n = 7); a third group C (n =7) was a control group of normal subjects. Groups A and C received 500 mg tablets of propionyl l-carnitine orally t.i.d. for 20 days. Group B received 40 mg of Buflomedil chlorhydrate i.v., b.i.d. for the same treatment period. Several blood cell viscosity parameters were evaluated. At the end of the trial it was possible to detect in the propionyl l-carnitine treated group a statistically significant decrease in haematic filtration time (HFT) and an increase in red blood cell flow velocity (Vrbc). Furthermore, some important rheological properties were noted, as demonstrated by modifications in the whole blood filtration, red blood cell flow velocity and viscosity of platelet-rich plasma following the addition of ADP.

Adenosine Diphosphate↗
PubMed1990

Fundamentals of EEG spectral analysis.

Recent progress in the fields of informatics and engineering has enabled a large diffusion of computers in clinical practice too. Availability of these computing facilities has introduced several quantitative methods to analyze electrophysiological signals. Among these techniques spectral analysis is the most used in quantitative electroencephalography. This article introduces some fundamental concepts of the theory of stochastic processes. The power density function and its descriptors useful in EEG analysis are also presented. The various possibilities of the appropriate application of this methodology are discussed.

Electroencephalography↗
PubMed1988

Mental impairment in aging: selection of patients, methods of evaluation and therapeutic possibilities of acetyl-L-carnitine.

The authors carried out a double-blind study in two randomized homogeneous groups of both sexes of 15 patients each, over 65 years of age and suffering from mild mental impairment. One group of patients underwent therapy with acetyl-L-carnitine, 2 g/day for three months, while the other group was treated with a placebo. The statistical evaluation of the results were carried out using nonparametric methods (Friedman-Nemenyi two-way Anova and Mann Whitney U-Test). However, the two groups did not differ significantly in either test at the end of treatment. It is possible to affirm that the acetyl-L-carnitine treated patients showed statistically significant improvement in the behavioural performances (Blessed Dementia Scale p less than 0.02; Stuard Hospital Geriatric Rating Scale p less than 0.01), in the memory tests (Rey short-term p less than 0.02; Rey long-term p less than 0.05; Corsi p less than 0.05), in the attention test (Barrage test p less than 0.01) and in the Verbal Fluency test p less than 0.01).

Acetylcarnitine↗
PubMed1987

Tentacle regeneration in Hydra: a quantitative methodological approach.

A quantitative method is proposed for the evaluation of distal regeneration in Hydra attenuata; it is based on estimates of tentacle elongation during 10 days of regeneration, determination of a Tentacle Regeneration Index, and a statistical analysis of profiles obtained from various samples in different experiments. The results show that: polyps under normal conditions have similar regeneration patterns, regardless of individual variability; and ATxII, a neurotoxin of cnidarian origin, produces a statistically significant increase in the Tentacle Regeneration Index. The results are discussed in relation to pattern formation and growth in Hydra.

Animals↗
PubMed1986

The EEG in the normal elderly: a contribution to the interpretation of aging and dementia.

Forty-seven normal elderly, 16 normal subjects ranging from 40 to 60 years of age and 14 patients affected by primary dementia are studied. The EEG is recorded from different brain areas and analysed by FFT algorithm. Main results are: There is persistence of the regional distribution of the alpha frequency which is higher in occipital than in frontal leads in the normal elderly. Spectral composition in the same group keeps its typical profile with age. Alpha-dominant tracings form 68%. Values collected from the two hemispheres are similar. Therefore, no evidence is detected for a selective age effect on one side, either right or left. In the elderly group, a sex-linked difference is found. Women have less delta and more beta frequency. The opposite holds true in men. EEG slowing is typical of old age. However, in occipital leads the alpha frequency has an average of 9.46 Hz. Statistical comparison between the normal groups (middle aged vs. elderly) gives no significant results. Significant differences are seen when the normal elderly are compared with demented subjects. The data do not support the hypothesis of a continuum from aging to mental deterioration.

Aged↗
PubMed1986

Minimum plasma lithium levels required for effective prophylaxis in DSM III bipolar disorder: a prospective study.

Four groups of DSM III bipolar patients, whose plasma lithium levels were maintained at 0.30-0.45 (group A), 0.46-0.60 (group B), 0.61-0.75 (group C), and 0.76-0.90 (group D) mEq/l respectively, were followed-up for two years. The mean number of affective episodes and the mean total morbidity during the lithium treatment period were significantly decreased in all groups except group A when compared with the pre-lithium period. Moreover, in group A, the mean total scores on CPRS depressive and manic items during the interepisodic periods were significantly higher than in each of the other groups. As a result of the low scores of patients in group A and the high scores of patients in group D on the side effect checklist, the frequency and intensity of side effects differed significantly among the four groups. These data suggest that, in the prophylactic treatment of bipolar patients, plasma lithium levels should, as a rule, be adjusted to the range 0.46-0.75 mEq/l.

Adult↗
PubMed1986

EEG changes induced by oxiracetam on diazepam-medicated volunteers.

The present study was carried out in order to verify whether, in benzodiazepine-medicated healthy volunteers, oxiracetam retained the properties already observed after administration in normal volunteers. In a cross-over study, 12 volunteers, medicated the night before with 5 mg diazepam, were i.v. treated with 1 g oxiracetam or saline. An electroencephalogram (EEG) was performed before, and 15 and 120 min after, nootropic or saline injection. Computerized examination of the EEG traces showed an increase of the alpha- and a decrease of the delta-relative activities, particularly in the fronto-temporal regions. These preliminary results suggest that oxiracetam might be useful in benzodiazepine-treated patients by improving their cognitive activities without nullifying the sedation of anxiety and neurotic behavior.

Adult↗
PubMed1985

Cluster analysis of cognitive performance in elderly and demented subjects.

48 elderly normals, 14 demented subjects and 76 young controls were tested for basic cognitive functions. All the tests were quantified and could therefore be subjected to statistical analysis. The results show a difference in the speed of information processing and in memory load between the young controls and elderly normals but the age groups differed in quantitative terms only. Cluster analysis showed that the elderly and the demented formed two distinctly separate groups at the qualitative level, the basic cognitive processes being damaged in the demented group. Age thus appears to be only a risk factor for dementia and not its cause. It is concluded that batteries based on precise and measurable tasks are the most appropriate not only for the study of dementia but for rehabilitation purposes too.

Age Factors↗
PubMed1985

Quantitative study of action tremor in various patient categories.

An electronic method is proposed for quantifying the action tremor revealed by a threefold test of skill, which distinguishes young adult controls from elderly normals and patients with tremor. Parkinsonian patients can be differentiated from patients with essential tremor. The value of drugs against tremor is discussed.

Adult↗
PubMed1985

Digital sampling rate and ECG analysis.

The influence of sampling rate on the accuracy of measurements of various ECG parameters has been studied. Statistical analysis showed no significant difference between results obtained at sampling rates of 500 and 250 samples s-1. Recordings made at 125 samples s-1, however, showed significant reductions in peak amplitude values. Some interval measurements also varied significantly to both larger and smaller values. Other intervals did not seem to be affected significantly. It is concluded that a sampling rate of 125 samples s-1 could be used in particular conditions when only the measurement of certain intervals is required.

Biomedical Engineering↗