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Biomedical subjects

M Calvani

Publications and source records attributed to M Calvani.

At least 91 records · Page 5Linked to original sources
PubMed1990

Role of acetyl-L-carnitine in the treatment of cognitive deficit in chronic alcoholism.

Preliminary data are reported from a multicentred double-blind placebo-controlled study concerned with the effects of acetyl-L-carnitine (LAC) on some cognitive deficits of at least one month-abstinent alcoholics. Fifty-five patients, showing impaired performance in at least two out of six mnemonic, praxic and verbal tasks, were randomly assigned to either LAC 2 g/day or a placebo group. They were tested by means of a neuropsychological battery exploring the areas of memory, constructional praxia, deductive-logical functions and language. Testing time was on baseline (T0), after 45 (T45) and 90 (T90) days. On the Rey's 15 word memory test (long-term), the Wechsler memory scale (logical memory), and the Similarities WAIS subtest, the T90 difference between LAC and the placebo was significant in favour of the former treatment. On the copying drawing test (simple copy), the placebo group did not show any T0-T90 variation, while significant improvement in the LAC group was greater than in the placebo group. As LAC has proved to ameliorate the performance or to accelerate the recovery on tests representative of all cognitive areas explored, it is conceivable that the drug acts diffusely, either at the cholinergic transmission or at the neuronal metabolism level. It is concluded that acetyl-L-carnitine can be a useful and safe therapeutic agent in the subtle cognitive disturbances of chronic alcoholics.

Acetylcarnitine↗
PubMed1989

Single-photon emission computed tomography studies with 99mTc-hexamethylpropyleneamine oxime in dementia: effects of acute administration of L-acetylcarnitine.

The acute effects of intravenously administered L-acetylcarnitine (LAC) were evaluated with single-photon emission computed tomography (SPECT) and 99mTc-hexamethylpropyleneamine oxime in 30 demented patients (21 with a clinical diagnosis of Alzheimer's dementia and 9 with mixed-type dementia). Two SPECT scans were performed: in basal conditions, and 30 min after the administration of 500, 1,000, 1,500, or 2,000 mg LAC intravenously. Tracer activity ratios were determined in 10 pairs of cerebellar, cortical and subcortical regions. After administration of the lowest dose of LAC, no changes from the basal values were observed in any of the regions examined. The higher doses of the drug significantly elevated the tracer activity in cortical regions, particularly in the parietal lobe, which showed an impaired regional cerebral blood flow in the basal study. These effects of LAC and their relation with the cholinomimetic properties of the drug are discussed.

Acetylcarnitine↗
PubMed1989

Neurophysiological studies of L-acetylcarnitine administration in man.

Systemic administration of L-acetylcarnitine HCl (LAC) increases in human subjects the amplitude of visual evoked potentials (VEPs) obtained with patterned elements of 7.5 min of visual angle, of steady-state VEPs obtained with intermittent luminous stimulation, of EEG theta, alpha and beta bands. The latency of the "cognitive" P300 potential obtained with an auditory "oddball" paradigm was also reduced by LAC injection, while the amplitude of this potential was increased. These results were obtained in control volunteers and in patients affected by different forms of dementias. The modifications induced by LAC appear 10-15 min after the i.v. injection and last for 50-90 min. These results parallel previously described findings of animal experiments and suggest an effect of LAC on cholinergic neurotransmission.

Acetylcarnitine↗
PubMed1989

[Magnesium and hypomagnesemia in childhood].

Magnesium and hypomagnesemia in pediatric age. Magnesium ion is of great physiological importance as attested to by intervention in 300 enzymatic systems, function in neuromuscular excitability and its role in membrane structure. Some aspects of its physiology, hormonal regulation and hypomagnesemia symptomatology, in light of the most recent literature data, are discussed.

Adolescent↗
PubMed1989

[The SSS syndrome. Description of a case and review of the literature].

A 1-month-old infant with an extensive dermatitis with flaccid bullae, without mucous membrane involvement is described. Staphylococcus aureus was recovered from blood, conjunctiva, skin and nasopharynx. A classification of Staphylococcal Scalded Skin Syndrome (SSSS), as well as etiology and therapeutic modalities, is briefly discussed.

Diagnosis, Differential↗
PubMed1987

L-acetylcarnitine in depressed elderly subjects. A cross-over study vs placebo.

An open, cross-over study was performed on a population of 24 geriatric patients hospitalized because of depressive syndrome. They were subdivided, according to Hamilton's Scale as modified for the aged, into low- and high-score subgroups. The study period covered 2 months. Half the patients received acetylcarnitine for 1 month and placebo thereafter (Group A); the other half received placebo and acetyl-carnitine thereafter (Group B). Statistical evaluation was twofold: parametrical analysis of variance was carried out on 4 subgroups (A1, A2, B1 and B2) and analysis of the score percentage modifications before and after treatment was performed on Groups A and B. The experimental results showed that acetylcarnitine treatment was highly effective and statistically significant in subgroups A1/B1, A2/B2, A1, B1 and B2. In particular, it should be noted that depressive tendencies were significantly modified in most groups, whereas general somatic symptoms as well as anxiety, asthenia and sleep disturbances proved to be little affected. Clinical evaluation, carried out by calculation of modifications in pre- and post-treatment score percentages, provided clear evidence that acetylcarnitine was particularly effective in patients showing more serious clinical symptoms. The drug caused no side-effects at the doses and regimens used.

Acetylcarnitine↗
PubMed1987

Effect of L-acetyl carnitine HCl on rat steady-state visual evoked potentials. Comparison with L-carnitine.

L-acetyl carnitine administration increases the amplitude of the steady-state visual evoked potentials (VEPs) obtained with sinusoidal luminance stimulation at 8.4 Hz. This effect was studied with three different doses of L-acetyl carnitine (50, 25, 5 mg/kg) and was compared with the results of injection of similar doses of L-carnitine. The effect is most evident when 50 mg/kg L-acetyl carnitine are administered and has two different time peaks. The second peak of activity showed a dose dependency when 25 mg/kg and 5 mg/kg doses were tested. The effects of L-acetyl carnitine could be depressed by the simultaneous administration of atropine sulfate.

Acetylcarnitine↗
PubMed1987

Effect of levo-acetylcarnitine on P300-like potentials of the normal monkey.

Endogenous components of evoked potentials resembling P300 in human beings were sequentially studied in four cynomolgus monkeys (Macaca fascicularis using an auditory "oddball" paradigm, after classical conditioning training. When robust P300-like signals were obtained, each animal underwent further recording sessions in which a placebo, L-carnitine or L-acetylcarnitine (LAC) was injected. Only LAC induced an amplitude increment of P300 waves in all the animals and a latency decrement in two animals. Furthermore a transient effect with amplitude reduction on the primary cortical auditory evoked potentials (AEP) both to rare and frequent tones was also recorded in all the animals. This effect resembled the AEP amplitude reduction induced by physostigmine administration. The findings suggest an effect of LAC on normal processes accompanying cognition.

Acetylcarnitine↗
PubMed1986

Hypogammaglobulinemia with hyper-IgM, severe T-cell defect, and abnormal recirculation of OKT4 lymphocytes in a girl with chronic lymphadenopathy.

We describe here one 8-year-old girl with an unusual form of immunodeficiency, characterized by hypogammaglobulinemia with hyper-IgM, severe T-cell defect, and chronic lymphadenopathy. Patient's B cells failed to produce IgG or IgA in vitro following stimulation with either pokeweed mitogen or Epstein-Barr virus, suggesting an intrinsic B-cell defect. Abnormal T-cell function was demonstrated by impaired in vivo delayed type hypersensitivity, reduction of mitogen-induced proliferation and interleukin 2 production, reduction of interferon-gamma production, and marked decrease of circulating OKT4+ cells. The latter cells were found in normal proportion in the patient's lymph node tissue. This finding suggests that the decrease of OKT4+ cells in peripheral blood was due to the abnormal recirculation of these cells. The identity of this syndrome with the infantile form of the acquired immunodeficiency syndrome was apparently ruled out by the failure to demonstrate HTLV-III-related sequences in patient's lymphocytes or virus-specific serum antibodies.

Agammaglobulinemia↗
PubMed1986

Behavioral effects of acetyl-l-carnitine in the male rat.

The behavioral activity of carnitine acetylate derivative, acetyl-l-carnitine has been studied in the male rat. Intraperitoneal (IP) injection of acetyl-l-carnitine was followed by an increase in ambulation and rearing items in the open field behavior. Both the number of conditioned avoidance response (CARs) and the percentage of learners in the acquisition of shuttle-box active avoidance behavior appeared to be increased by IP or intracerebroventricular (ICV) injection of the drug at different doses. Subchronic administration of the drug mimicked the effects found after acute injection. The number of CARs in the extinction of shuttle-box active avoidance behavior appeared to be increased after acute IP or ICV injection, and after subchronic administration of acetyl-l-carnitine. The retention of passive avoidance behavior was facilitated by IP injection of the substance. The behavioral effects of acetyl-l-carnitine may involve central mechanisms, e.g., cholinergic neurotransmission in the brain.

Acetylcarnitine↗
PubMed1986

Effects of L-5HTP with and without carbidopa on plasma beta-endorphin and pain perception: possible implications in migraine prophylaxis.

L-Tryptophan (L-TP) has been used in migraine and other pain conditions. The mechanism underlying the analgesic effect is still partly undefined. In this study the effects of subchronic administration of L-5-hydroxytryptophan (L-5HTP) (with and without carbidopa) on plasma beta-endorphin (beta-EP) levels and subjective pain threshold and tolerance were investigated in seven healthy volunteers. To measure also an objective indicator of pain, the nociceptive flexion reflex threshold was studied. L-5HTP treatment with and without carbidopa administration increased beta-EP levels significantly (p less than 0.05). L-5HTP plus carbidopa induced an increase in beta-EP significantly (p less than 0.05) greater than that induced by L-5HTP alone. Neither the subjective pain threshold and tolerance nor the RIII threshold was modified by either treatment. Our data seem to point to the existence of a complex linkage between plasma opioid levels and pain perception.

Adult↗
PubMed1986

Effects of L-5HTP with and without carbidopa on plasma beta-endorphin and pain perception. Possible implications in migraine prophylaxis.

L-Tryptophan (L-TP) has been used in migraine and other pain conditions. The mechanism underlying the analgesic effect is still partly undefined. In this study the effects of subchronic administration of L-5-hydroxy-tryptophan (L-5HTP) (with and without carbidopa) on plasma beta-endorphin (beta-EP) levels and subjective pain threshold and tolerance were investigated in seven healthy volunteers. To measure also an objective indicator for pain, the nociceptive flexion reflex threshold was studied. L-5HTP treatment with and without carbidopa administration increased beta-EP levels significantly (p less than 0.05). L-5HTP plus carbidopa induced an increase in beta-EP significantly (p less than 0.05) higher than that after L-5HTP alone. Neither subjective pain threshold and tolerance nor RIII threshold was modified by either treatment. Our data seem to point to the existence of a complex linkage between plasma opioid levels and pain perception.

5-Hydroxytryptophan↗
PubMed1986

Effects of carnitine administration in patients with chronic renal failure undergoing periodic dialysis, evaluated by computerized electromyography.

The effects of chronic administration of L-carnitine were evaluated by EMG analysis in 20 uraemic patients undergoing periodical haemodialysis (mean duration of dialysis 34.7 months). No important changes in motor conduction velocity or distal latency of the external popliteal nerve were found after the treatment, while a reduction in the number of polyphasic muscle action potentials was observed. After carnitine administration, an increase of total EMG power was noted and the spectral array showed a progressive shift towards lower frequencies in 8 patients who had shown higher values. These results suggest that carnitine has a prevalent "myotrophic" effect.

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

Effects of intravenously administered L-acetylcarnitine on somatosensory-evoked potentials. Studies of healthy and diseased volunteers with focal cerebral lesions.

The acute effects of intravenously administered L-acetylcarnitine (L-AC) were evaluated in 5 healthy and 20 diseased volunteers (17 vascular, 3 tumoral cerebral lesions). Short-latency scalp somatosensory-evoked potentials (SEPs) to simultaneous median, and separate unilateral peroneal nerve stimulation were carried out before and after L-AC administration (at 10-, 30- and 60-min intervals). L-AC did not influence peak and interpeak latencies; however, in a percentage of healthy and diseased volunteers a clear-cut amplitude increase was evident affecting all those peaks generated between the thalamus and the cortex. While in normal and tumoral volunteers the voltage increase was bilaterally balanced, the amplitude increments were more evident on the 'affected' hemisphere in vascular patients, partially reversing the abnormal amplitude ratios between homologous peaks on 'healthy' and 'affected' hemispheres. In no case were transient clinical changes, either of an objective or subjective nature, associated with SEP amplitude changes; these were still present at the 60th minute, having reached their nadir at the 30th minute in 'responders'.

Acetylcarnitine↗