Biomedical subjects

Claudio Mariani

Publications and source records attributed to Claudio Mariani.

27 records · Page 2Linked to original sources

PubMed2004

MCP-1 in Alzheimer's disease patients: A-2518G polymorphism and serum levels.

MCP-1 levels are increased in CSF of patients with Alzheimer's disease (AD) compared with controls, suggesting a role in the development of dementia. Recently, a biallelic A/G polymorphism in the MCP-1 promoter at position -2518 has been found, influencing the level of MCP-1 expression in response to an inflammatory stimulus. The distribution of the A-2518G SNP was determined in 269 AD patients and in 203 healthy age matched controls, showing no differences between the two groups. On the contrary, a significant increase of MCP-1 serum levels in AD patients carrying at least one G mutated allele was observed. Moreover, the highest peaks of MCP-1 serum levels were present in patients carrying two G alleles. Stratifying by ApoE genotype, gender or age at onset, no differences in both allele frequency and MCP-1 serum concentration were observed. The A-2518G polymorphism in MCP-1 gene does not seem to be a risk factor for the development of AD, but its presence correlates with higher levels of serum MCP-1, which can contribute to increase the inflammatory process occurring in AD.

Age of Onset↗

PubMed2004

Cutaneous silent period in human immunodeficiency virus-related peripheral neuropathy.

The aim of this work was first to determine whether the cutaneous silent period (CSP), a marker of small-nerve-fibre function, was altered in human immunodeficiency virus (HIV)-positive subjects with predominantly sensory symmetrical polyneuropathy and, second, to assess whether such alterations were predictive of an impairment in the largest calibre sensory and motor nerve fibres of the upper limb (UL) peripheral nerves. CSP was assessed in three groups of subjects: healthy control subjects, HIV-positive subjects with peripheral neuropathy (PN) of the lower limbs, and HIV-positive patients with clinical and neurophysiological involvement of the four limbs. CSP study showed a significant increase of the latency compared to the controls both in HIV-positive cases with no impairment in the UL (p=0.006) and in patients with four-limb neuropathy (p=0.002). CSP study in HIV-positive patients with mild lower limb distal sensory polyneuropathy can detect an early involvement of the UL peripheral nerves. CSP latency increase could therefore be addressed as the first sign of PN spreading to the UL.

Electric Stimulation↗

PubMed2003

1-40 Beta-amyloid protein fragment modulates the expression of CD44 and CD71 on the astrocytoma cell line in the presence of IL1beta and TNFalpha.

The modulation of CD44, VCAM-1 and CD71 expression was analysed by flow cytometry in the 1321N1 astrocytoma cell line in the presence of interleukin-1beta (IL1beta), tumour necrosis factor-alpha (TNFalpha) and 1-40 or 25-35 beta-amyloid (Abeta) fragments. The percentage of 1321N1 astrocytoma cell line expressing these markers increased significantly after treatment with TNFalpha or IL1beta. The presence of Abeta 1-40 fragment, alone or in combination with IL1beta, induced an increase in the percentage of cells expressing CD44, but not VCAM-1. However, the concomitant presence of Abeta 1-40 fragment and of IL1beta or TNFalpha caused an increase in the percentage of CD71 positive cells. In contrast, the shorter Abeta 25-35 fragment was always inactive. These results indicates that Abeta 1-40 fragment, in association with cytokines, can activate this astrocyte-derived cell line and add further elements in favour of the hypothesis that beta-amyloid can act as immunological mediator.

Amyloid beta-Peptides↗

PubMed2003

Body weight gain rate in patients with Parkinson's disease and deep brain stimulation.

We evaluated body weight changes in patients with Parkinson's disease (PD) after electrode implantation for deep brain stimulation (DBS) in the subthalamic nucleus (STN) in relation to clinical improvement. Thirty PD patients who received STN DBS were included (22 men, 8 women; mean age, 60.0 +/- 7.1 years; mean PD duration, 13.5 +/- 3.7 years; mean body mass index [BMI], 21.6 +/- 3.0 kg/m2). Body weight, physical activity, and Unified Parkinson's Disease Rating Scale (UPDRS) scores were noted before and 3 and 12 months after the procedure. Significant weight gain occurred in 29 patients; the mean increase was 14.8 +/- 9.8% of initial body weight in 1 year. Of the patients, 46.5% reported weight gain in the first 3 months, 21.4% gradual weight gain in the first 6 months, and 32.1% a slow increase for 1 year. Mean BMI increased up to 24.7 +/- 3.7 kg/m2. After 1 year, mean UPDRS motor score improved significantly in off and in on; and therapy complications improved by 91.0 +/- 17.0%. BMI changes at 3 and 12 months were significantly correlated to dyskinesia score changes, and levodopa dosage was not. In PD, STN DBS produces not only symptom control, but also weight gain. DBS candidates should be given nutritional counseling before the intervention to prevent rapid and/or excessive weight gain.

Body Mass Index↗

PubMed2002

Cloning and functional analysis of the allelic polymorphism in the transcription regulatory region of interleukin-1 alpha.

A strong correlation between the TT(-889) genotype over CC(-889) of the interleukin-1 alpha (IL-1 alpha) transcription regulatory region and age of Alzheimer's disease onset has recently been reported. To determine the functional effects of the genetic variants on plasma protein levels, we cloned the promoter region and determined its activity. The TT genotype significantly increased the transcriptional activity of the IL-1 alpha gene with respect to the CC genotype. A slight increase of the IL-1 alpha mRNA and protein levels was also observed in the plasma.

Alleles↗

PubMed2002

The Interleukin 1-beta exonic (+3953) polymorphism does not alter in vitro protein secretion.

Several studies have described polymorphisms in the genes encoding interleukin-1alpha (IL-1alpha) and IL-1beta cytokines and their implication in the onset of Alzheimer disease or in linkage disequilibrium with an as yet to be identified second locus on chromosome 2. However, these results have been associated with the sporadic forms of Alzheimer disease. Here we present data on the effects of the interleukin 1-beta exonic polymorphism (+3953) using a series of cohort healthy control samples and in vitro protein secretion assays.

Cohort Studies↗

PubMed2002

Direction and position factors in performance of line extension task by unilateral neglect subjects.

In this study was investigated the influence of direction and position in the performance of a line extension task by patients with unilateral neglect, with the aim of exploring the role of perceptual and premotor factors in this task. Twenty-three right brain damaged patients (14 patients with left unilateral neglect) were asked to extend horizontal lines both leftward and rightward; lines were presented in three different positions (left, right and central). Patients with neglect significantly overextended the lines in all conditions, but particularly toward the sagittal mid plane of the body and leftward when the line was presented on the right. The global overextension seem to be related to concomitant hemianopsia. A crucial finding in neglect group was that left extensions reduced progressively on passing from right through central to left presentation, particularly in patients with lesions involving frontal regions or the basal ganglia. The last finding supports the hypothesis that left overextension does not exclude the coexistence of both perceptual and premotor factors (causing directional hypometria) in left unilateral neglect.

Aged↗

PubMed2002

Frontal impairment and confabulation after herpes simplex encephalitis: A case report.

We describe the rehabilitation training of a 53-year-old woman with severe confabulatory and dysexecutive syndrome, as well as memory impairment, after herpes simplex encephalitis (HSE). Secondary narcolepsy was also present. Neuropsychologic deficits were detailed through an extensive examination, and specific techniques were used to improve performances in each defective cognitive domain. Improvement of vigilance and attention was reached through appropriate and timed periods of rest, along with attentional tasks of growing difficulty. Different external aids were used to reduce temporal disorientation, to contrast confabulation and inertia, and to overcome memory deficits in everyday life. Their independent use by the patient was implemented through cues that were progressively reduced. Treatment also focused on planning, categorization, and topographic orientation. The patient's family gave constant support during rehabilitation and provided informal training after discharge. The patient was able to regain independence in everyday life at home.

Cognition Disorders↗

PubMedDate not supplied

Protein misfolding in Alzheimer's and Parkinson's disease: genetics and molecular mechanisms.

The accumulation of altered proteins is a common pathogenic mechanism in several neurodegenerative disorders. A causal role of protein aggregation was originally proposed in Alzheimer's disease (AD) where extracellular deposition of beta-amyloid (Abeta) is the main neuropathological feature. It is now believed that intracellular deposition of aggregated proteins may be relevant in Parkinson's disease (PD), amyotrophic lateral sclerosis and polyglutamine disorders. An impairment of ubiquitin-proteasome system (UPS) appears directly involved in these disorders. We reviewed the results on the role of protein misfolding in AD and PD and the influence of mutations associated with these diseases on the expression of amyloidogenic proteins. Results of genetic screening of familial cases of AD and PD are summarized. In the familial AD population (70 subjects) we found several mutations of the presenilin 1 (PS1) gene with a frequency of 12.8% and one mutation in the gene encoding the protein precursor of amyloid (APP) (1.4%). One mutation of Parkin in the homozygous form and two in the heterozygous form were identified in our PD population. We also reported data obtained with synthetic peptides and other experimental models, for evaluation of the pathogenic role of mutations in terms of protein misfolding.

Aged↗