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Biomedical subjects

L Parnetti

Publications and source records attributed to L Parnetti.

At least 91 records · Page 5Linked to original sources
PubMed1988

Extracranial carotid atherosclerosis evaluation and stroke occurrence: role of the echotomographic analysis.

High-resolution real-time echotomography was used in a longitudinal study on 118 atherosclerotic plaques of the extracranial carotid tract with the aim of identifying those most likely to cause a cerebrovascular event. Seventy patients (average age 61 +/- 7 years), referred to our Clinical Vascular Laboratory because suffering from transient cerebral ischemic attacks (TIA), coronary heart disease (CHD, peripheral artery disease (PAD), or cervical bruits (CB), were followed up for two years. Medical treatment remained that of the referring physician. Ten patients suffered from clinical events caused by stroke, TIA, and/or carotid occlusion during the follow-up. The echostructural profile of the lesions most often correlated with the clinical event was characterized by a mixed or hard echogenic pattern, and irregular surface, and an initial vascular stenosis of more than 50%.

Aged↗
PubMed1987

Monoamines and their metabolites in cerebrospinal fluid of patients with senile dementia of Alzheimer type using high performance liquid chromatography and gas chromatography-mass spectrometry.

Monoamines and their main metabolites were measured using HPLC-EC in the cerebrospinal fluid from age-matched elderly in-patients affected with senile dementia of Alzheimer type and chronic schizophrenia. Determination of the monoamine metabolites MHPG, HVA and 5-HIAA was also performed by means of gas chromatography-mass spectrometry. Significant differences were obtained with the two methods, the largest deviation being found for HVA, which was 15% higher in the HPLC method than in the GC-MS method, despite the correlation between the results of two measurements being consistent for all the three metabolites. The degrees of motor, intellectual and emotional deterioration were assessed using GBS rating scale. The results show a clear psychobehavioral and neurochemical differentiation of the two patient groups. HVA and 5-HIAA levels were significantly lower in SDAT patients, and showed a trend toward negative correlation with the degree of dementia.

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PubMed1986

Chronic cerebrovascular disorders: hemorheological and psychobehavioral aspects.

In order to evaluate the existence of a correlation between the hemorheological and the psychobehavioral pattern in chronic cerebrovascular disorder (CCVD) patients, 54 elderly CCVD patients were enrolled in the study. After a thorough clinical and instrumental examination they underwent a hemorheological and psychobehavioral assessment. The results showed a clear correlation between the severity of the psychobehavioral disorder and the hemorheological alterations, particularly with regard to the cellular factors. A hypothesis to explain these findings and future research trends are also discussed.

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PubMed1986

Haemorheological markers in 89 patients with stage II peripheral vascular disease (PVD).

Although it is universally accepted that the grade of reduction of district blood flow in PVD is directly correlated to alteration of the haemorheological pattern, there is still no uniformity of opinion regarding the existence of a specific rheological alteration in PVD. The scope of our study was to discover the existence of possible PVD-specific markers; we thus carried out a comparative evaluation of the rheological characteristics in blood of controls and patients affected with PVD. Eighty-nine males between the ages of 50 and 65 years (median 58 +/- 1 SE) were studied, all with a stage II vascular pathology with clinical onset of less than three months. Exclusion criteria were: diabetes mellitus, hyperlipaemia, stable hypertension, presence of vascular disease in other districts, cardio-circulatory problems and serious medical or surgical pathologies, previous vascular surgery, a history of acute thrombo-embolic episodes, and chronic alcoholism. Each patient, after a drug wash-out of 20 days, was monitored for haemorheological parameters. At the same time, the above parameters were measured in a group of 50 male controls of the same age range. All 139 subjects were smokers (10-15 cigarettes average per day). Our results indicate that modification in the bio-humoral (fibrinogen and plasma globulins) parameters, a reduced red blood cell filterability and a relative increase in the number of activated polymorphonucleate cells are probably specific haemorheological markers of the clinical onset of PVD.

Blood Cell Count↗
PubMed1986

The role of haemorheological factors in the ageing brain: long-term therapy with pentoxifylline ('Trental' 400) in elderly patients with initial mental deterioration.

Sixty elderly patients suffering from initial mental deterioration (less than 6 months) were divided at random into two groups, homogeneous for age, sex and life habits. For 28 weeks Group I was given a placebo and Group II was given 400 mg pentoxifylline ('Trental' 400) 3-times daily for two 3-month periods interrupted by a 4-week wash-out period. Neuropsychological performance and haemorheological parameters were evaluated at the beginning and at the end of each phase of the study. The results showed that pentoxifylline medication significantly improved the psycho-intellectual performance, decreased whole blood viscosity and increased red cell filterability. The results indicate a need to concentrate further study on haemorheological factors in the clinical aspects of the ageing brain, also with a view to allowing for sufficiently long treatment periods.

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PubMed1985

Memory impairment in the elderly: a three-year follow-up.

A 3-yr follow-up study on the trend of memory performance in 9 elderly subjects with selective memory defects, which was carried out in an attempt to clarify the evolution of the disorder, revealed marked worsening of sensory visual memory, retention capacity and recent memory. No other mental function was compromised. The results of this study suggest that the onset of a selective memory defect in the elderly is not necessarily the expression of a demential amnestic syndrome, but rather the manifestation of a senile brain deterioration limited to the anatomo-functional memory system.

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PubMed1985

Haemorheological pattern in initial mental deterioration: results of a long-term study using piracetam and pentoxifylline.

A group of 80 elderly subjects affected with recent onset (less than 6 mth) slight to moderate mental deterioration was observed before and after oral drug treatment for a period of 28 wk. The study consisted of four randomized groups of subjects homogeneous for age, sex and life habits. The first group received a placebo, the second group received piracetam (1600 mg 3 times a day), the third group received pentoxifylline (400 mg 3 times a day), and the fourth group received a combination of piracetam and pentoxifylline. At the beginning and end of each phase of the study, neuropsychological and haemorheological parameters were evaluated in all subjects. The results show that the most evident improvement in psycho-intellectual performance, associated with an increase of whole blood filtration values, was obtained in the group treated with the two-drug combination.

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PubMedDate not supplied

Platelet MAO-B activity and vitamin B12 in old age dementias.

Platelet MAO-B activity, serum vitamin B12 levels, and plasma folate were measured in patients suffering from presenile (AD) and senile (SDAT) dementia of Alzheimer-type, and vascular dementia (VD). MAO-B was higher in the SDAT group than in AD and controls. An inverse relationship between MAO-B activity and vit. B12 levels was documented in the whole group and in each category studied; furthermore, MAO-B was positively related to age. All the patients were then divided into two groups, according to vit. B12 levels (Group I: less than 200 pg/mL; Group II: greater than or equal to 200 pg/mL); Group I showed a significantly higher MAO-B activity with respect to Group II. The results indicate the existence of a negative association between platelet MAO-B activity and serum levels of vitamin B12 and confirm the existence of biological differences between presenile and senile dementia of Alzheimer type.

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PubMedDate not supplied

CSF monoamine metabolites in old age dementias.

Cerebrospinal Fluid (CSF) levels of the main metabolites of monoamines (MHPG, 5-HIAA, and HVA) were measured in patients with early onset (AD) and late-onset (SDAT) Alzheimer's disease, vascular dementia (VD), and elderly controls. Psychobehavioral assessment was carried out by means of MMSE and GBS. Mean MHPG levels did not differ from controls; 5-HIAA was lower in VD when compared to both controls and SDAT. HVA was decreased in AD, SDAT, and VD with respect to controls. Significant correlations between HVA and psycho-behavioral parameters were observed in SDAT and VD groups, whereas no relationship was documented in AD. The SDAT group was divided in SDAT-A (age at onset: greater than 65 less than or equal to 80 yr) and SDAT-B (age at onset: greater than 80 yr). SDAT-A had significantly lower CSF HVA values than SDAT-B (165 +/- 64 vs 235.7 +/- 85). SDAT-B HVA levels were similar to those observed in controls. Correlation analysis between HVA and neuropsychological variables was significant in SDAT-A, but not in SDAT-B. These results might support the evidence of SDAT heterogeneity.

Aged↗
PubMedDate not supplied

Comparative kinetics of oxiracetam in serum and CSF of patients with dementia of Alzheimer type.

The purpose of the study was to determine whether oxiracetam crosses the human blood-brain barrier and to evaluate its comparative kinetics in serum and in cerebro-spinal fluid (CSF). Six DAT patients, undergoing CSF collection for diagnostic purposes, received 2 g oxiracetam daily, by a 60 min i.v. infusion, for 7 days. On the last day, in four patients blood samples were collected at time 0, 30, 60 and 120 min, and lumbar drainage was performed at the end of infusion: at this time mean CSF concentration was 3.5 micrograms/ml, i.e. 4.0% of the serum one, demonstrating that oxiracetam crosses the blood-brain barrier. In two patients, blood samples were collected at time 0, 60, 120 and 240 min, and lumbar drainage was performed 60 min after the end of infusion: at this time mean CSF concentration was 2.8 micrograms/ml, i.e. 5.3% of the serum one, indicating a persistence of oxiracetam within this deep compartment. These results provide the first evidence in humans that oxiracetam penetrates the central nervous system and contribute to the understanding of its long-lasting pharmacodynamic effect in man.

Aged↗
PubMedDate not supplied

Blood pressure and functional aspects of the aging brain.

This study was carried out to define the effects of both long-term hypertension and hypotension on the cerebral functioning of the elderly, comparing them to the effects of normotension. Ninety-eight subjects of both sexes, between 70 and 82 years of age, were divided into three groups on the basis of their mean blood pressure: 33 normotensives, 36 hypotensives and 29 hypertensives. They underwent a neuropsychological assessment, a haemorrheological evaluation and an EEG monitoring while awake. The results show that the three parameters were almost always within normal limits in the normotensives, while EEG alterations, lower neurophysiological scores and blood hyperviscosity were noted in both the hypertensives and hypotensives. Our results would seem to confirm that long-term hypertension may induce alterations in the cerebral electrogenesis and intellectual functions of the elderly and that also long-term hypotension might negatively interfere with some functional aspects of the aging brain.

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PubMedDate not supplied

Idebenone in senile dementia of Alzheimer type: a multicentre study.

Idebenone is a new cerebro-active drug, effective in dementia disorders, particularly indicated in primary degenerative dementias, i.e. Alzheimer's disease. This new molecule acts as an electron trapper and a free radical scavenger protecting mitochondrial membranes from lipid peroxidation. A multicentric, double-blind trial of idebenone (45 mg twice daily orally) vs. placebo was carried out on 102 elderly patients affected by Alzheimer-type dementia of mild or moderate severity. Idebenone was administered for 4 consecutive months, 45 mg twice daily. Clinical evaluations were performed at the time of enrollment (t0) and monthly thereafter (t30, t60, t90 and t120) and at follow-up (t150 ). Tolerability to idebenone treatment was good and was associated with a statistically significant improvement of memory, attention and behaviour. It is worthwhile noting that these cognitive and behavioral findings were observed after the first month of treatment with enhancement evident in the following period.

Clinical Trial↗
PubMedDate not supplied

Dexamethasone suppression test in elderly patients with dementia of Alzheimer type, vascular dementia and stroke: a re-evaluation of its applicability.

In order to evaluate the prevalence of non-suppression after dexamethasone in psychogeriatrics and to further verify the reliability of the neurobiological information obtained, dexamethasone suppression test was carried out in a geriatric population composed of patients with dementia of Alzheimer type, vascular dementia, stroke and age and sex-matched controls. Basal cortisol levels did not differ among groups and was positively correlated to age. Prevalence of non-suppression, defined according to Carroll's criterion was high in the pathological groups studied, and relatively high in controls, showing no diagnostic value. Unlikely suppressors, the time course of mean plasma corticol levels of non-suppressors was highly heterogeneous in each group considered, especially in the pathological groups. More restrictive criteria for the definition of non-suppressors are proposed, in order to increase the specificity of the test when applied to psychogeriatrics.

Journal Article↗
PubMedDate not supplied

Dihydroergokryptine vs. placebo in dementia of Alzheimer type: interim results of a randomized multicenter study after a 1-year follow-up.

In order to evaluate the efficacy of dihydroergokryptine mesylate (DEK) - a semisynthetic ergot alkaloid having a neuroprotective activity through the activation of antioxidant enzymatic systems - in dementia of Alzheimer type, a long-term, randomized, placebo-controlled, double-blind study was carried out. The interim analysis after 1-year follow-up is here reported. Two-hundred-and-fifteen patients fulfilling the NINCDS-ADRDA criteria for probable Alzheimer's disease were enrolled by 14 geriatric and neurologic Italian centers. The study design included a 1-month pre-treatment phase with placebo; 1-year double-blind treatment with DEK or placebo; a further 1-year open phase of treatment with DEK. The active drug dosage was 5 mg bid orally administered for the first 2 weeks, 10 mg bid for the following 2 weeks, 20 mg bid for the following 11 months. Efficacy was assessed by means of Gottfries-Bråne-Steen (GBS) Rating Scale for dementia and Mental Deterioration Battery. The univariate analysis showed a significant improvement of GBS subscales and factors (with the exception of the Factor III, depression-anxiety). Multivariate analysis showed a significant difference between treatments in GBS scale (P=0.002) without any influence of age and illness duration. These results were confirmed by the end-point analysis carried out on GBS scores using baseline value as covariate. Minor adverse events were observed in 9 out of 108 patients (8.3%) of the DEK group and in 7 out of 107 (6.5%) of the placebo group. No change in blood pressure, heart rate and routine laboratory tests was observed. These preliminary results suggest positive symptomatic effects of DEK on elderly patients with probable Alzheimer's disease indicating a slowing down of the cognitive decline.

Clinical Trial↗
PubMedDate not supplied

The region 1-11 of Alzheimer amyloid-beta is critical for activation of contact-kinin system.

Amyloid-beta protein (Abeta) has been implicated in the pathogenesis of Alzheimer's disease (AD) because of its neurotoxicity and its ability to trigger a local inflammatory response. In the present study using truncated Abeta peptides, we identified the region between residues 1 and 11 as critical for the activation of the contact system in vitro through an ionic interaction of Abeta with factor XII and/or kallikrein. Concomitant incubation of a small cationic peptide (lysine(4)) with Abeta abrogated its ability to trigger the cleavage of high molecular weight kininogen, indicating that Abeta's activity can be blocked by an inhibitory peptide. These findings could be clinically important, since there is evidence that the contact system is activated in AD brain. Thus, prevention of contact system activation, beside diminishing the recruitment of glial cells and microvascular permeability, can also decrease the activation of complement system and the release of IL6, both factors being considered to play an important role in the inflammatory reactions in AD brain.

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PubMedDate not supplied

Clinical and genetic analysis of hereditary and sporadic ataxia in central Italy.

We have clinically and genetically evaluated 24 affected patients belonging to 22 Italian Friedreich ataxia (FA) families, 52 patients from 32 kindreds with proven autosomal dominant cerebellar ataxia (ADCA), 9 patients belonging to 5 families with autosomal recessive hereditary ataxia (ARCA) and 103 sporadic cases, 89 of which affected by idiopathic late onset cerebellar ataxia (ILOCA). Genotype-phenotype correlation analyses in FA patients have evidenced an inverse relationship between GAA repeat expansion length and age of onset, disease duration, and presence of cardiomyopathy. Among autosomal dominant types, spinocerebellar ataxia 2 (SCA2) genotype has been found in 31% of our ADCA families, resulting the most frequent form of ataxia. Phenotypic analysis of the various SCA subtypes evidenced a marked heterogeneity of symptoms with a substantial overlap between different syndromes.

Adult↗