Search PubMed⌕ Search

Biomedical subjects

G Magnani

Publications and source records attributed to G Magnani.

At least 19 recordsLinked to original sources
PubMed2006

The contribution of voxel-based morphometry in staging patients with mild cognitive impairment.

OBJECTIVE: To assess whether different patterns of regional gray matter loss in patients with mild cognitive impairment (MCI) are associated with different risks of conversion to Alzheimer disease (AD), using MRI and voxel-based morphometry (VBM). METHODS: The authors recruited 22 patients with MCI, 22 patients with probable AD, and 20 healthy subjects (HS). T1 volumes from each subject were postprocessed according to an optimized VBM protocol. All patients were clinically followed up (mean [SD] time = 28.7 [5.7] months), and patients with MCI were reclassified into two groups (converters and nonconverters to AD). RESULTS: When comparing patients with AD to HS, widespread areas of reduced gray matter density were found predominantly in temporal, frontal, and parietal lobes and in the insula. Comparing MCI converters and nonconverters with HS, the converters showed more widespread areas of reduced gray matter density than nonconverters, with a pattern of abnormalities similar to that seen in patients with AD. Conversely, when comparing the same groups with patients with AD, MCI nonconverters showed a pattern of gray matter density similar to that of HS. Areas of decreased gray matter density were also found in MCI converters compared with nonconverters. CONCLUSIONS: Different patterns of gray matter density distribution in patients with mild cognitive impairment may be associated to different rates of conversion to Alzheimer disease.

Aged↗
PubMed2006

Long-term safety and effectiveness of statins for heart transplant recipients in routine clinical practice.

BACKGROUND: Whereas the efficacy of statins after heart transplantation (HT) in controlled study settings has been clearly demonstrated, more extensive data are required on the safety and effectiveness of long-term treatment in routine clinical practice. METHODS: We analyzed the risks and benefits in clinical practice of treatment with statins in all patients who survived HT for at least a month from December 1985 through 2001. RESULTS: During a mean follow-up of 4.8+/-3.8 years, 186 patients were treated with statins (for a median duration [25th to 75th percentile] of 29 [12 to 54] months), while 48 received dietary therapy alone. Patients treated with statins (pravastatin, 48%; atorvastatin, 37%; simvastatin, 14%) presented linearized rates of rhabdomyolisis, myositis, and significant transaminase elevation of 0.37%, 0.74%, and 0.37% per year of treatment, respectively (no fatal event occurred). Low-density lipoprotein decreased after statins by 19% (P<.001). At multivariate analysis, treatment with statins was independently associated with reduced risk of cardiac allograft vasculopathy and overall mortality (P<.001). CONCLUSIONS: Our data provide necessary confirmation of the safety and effectiveness in routine clinical practice of appropriately monitored long-term administration of statins (particularly atorvastatin, pravastatin, and simvastatin) in the chronic post-HT phase. Strict follow-up is needed for HT recipients receiving high doses of statins with/without other medications potentially exacerbating the risk of adverse effects.

Adult↗
PubMed2005

A whole brain MR spectroscopy study from patients with Alzheimer's disease and mild cognitive impairment.

Brain damage in Alzheimer's disease (AD) and mild cognitive impairment (MCI) is widespread with involvement of large portions of the neocortex and the subcortical white matter. A quantitative measure of neuronal damage of the entire brain might be valuable in the context of large-scale, longitudinal studies of these patients. This study investigated the extent of neuroaxonal injury of patients with AD and MCI using a novel unlocalized proton magnetic resonance spectroscopy ((1)H-MRS) technique, which allows quantification of the concentration of N-acetylaspartate from the whole of the brain tissue (WBNAA). Conventional brain MRI and WBNAA were obtained from 28 AD patients, 27 MCI patients and 25 age-matched controls. Normalized brain volume (NBV) was also measured using an automated segmentation technique. WBNAA and NBV showed a significant heterogeneity between groups (P < 0.001). WBNAA concentration was different between controls and MCI patients (P = 0.003), but not between MCI and AD patients (P = 0.33). NBV differed both between controls and MCI patients (P = 0.02) and between MCI and AD patients (P = 0.03). A multivariate regression model retained WBNAA as the best MRI predictor of the Mini Mental State Examination score (P = 0.001). Significant neuronal damage, which is related to the extent of cognitive decline, can be quantified in the whole brain tissue of patients with AD, using a novel (1)H-MRS approach. The demonstration in patients with MCI of MR structural and metabolic findings, intermediate between those of healthy volunteers and those of AD patients, indicates that neuronal damage is already evident and widespread in individuals with MCI before they are clinically demented.

Aged↗
PubMed2002

Acute effects of L-dopa on event-related desynchronization in Parkinson's disease.

We tested whether dispersible L-dopa has acute effects on event-related desynchronization (ERD) of the mu rhythm in patients with idiopathic Parkinson's disease (IPD). ERD to voluntary movement is delayed in akinetic IPD patients and improves after chronic L-dopa treatment. We evaluated ERD to self-paced finger movement in 14 IPD patients (before and 30-40 min after oral administration of dispersible L-dopa) and in 10 normal subjects. Sensorimotor ERD onset contralateral to movement was significantly delayed in IPD patients compared to normal subjects. This abnormality was no longer significant after L-dopa treatment. We conclude that a single dose of dispersible L-dopa can improve not only motor performance in IPD patients but also the timing of cortical activation of sensorimotor areas during motor programming.

Aged↗
PubMed2002

Folate supplementation after heart transplantation: effects on homocysteine plasma levels and allograft vascular disease.

BACKGROUND AND AIMS: After heart transplantation, the effects of folate supplementation on total homocysteine plasma levels (THcy) and heart allograft vascular disease (AVD) remain unclear. METHODS: Accordingly, we prospectively analyzed 48 heart transplant receipients referred for routine follow-up from July to September 1998 (age 54+/-11 years, 75% male, 35+/-27 months from transplant). Among these patients, 17 were treated with folate supplementation for 12 months (Group F), while 31 cross-matched for age, gender, serum creatinine and time from transplant (P>0.3 vs Group F for all) did not assume folate supplementation (Group NF). Routine coronary angiography for AVD detection was routinely obtained in every patient. RESULTS: THcy overall increased during the study period (from 16.6+/-6.5 to 19.4+/-7.6 micromol/l, P<0.001), and a strong trend toward higher THcy was observed in patients presenting AVD (22.4+/-8.7 vs 17.6+/-6.8 micromol/l, P=0.051). After 12 months THcy was lower in Group F as compared to Group NF (16.2+/-5.6 vs 21.1+/-8.1 micromol/l, respectively, P=0.033). CONCLUSIONS: Our results demonstrate that THcy increases over time in heart transplant recipients, and a strong trend toward higher THcy is observed in the presence of AVD. Since folate supplementation appears to positively influence THcy, a favorable effect of folate on AVD can be hypothesized.

Coronary Angiography↗
PubMed2001

Quantification of tissue damage in AD using diffusion tensor and magnetization transfer MRI.

The authors measured mean diffusivity (D) and magnetization transfer ratio (MTR) of the brain from 18 patients with AD and 16 healthy control subjects. The peak heights of cortical gray matter (cGM) D (p < 0.001) and MTR (p < 0.001) histograms were lower and average cGM D (p < 0.01) higher in patients with AD than in control subjects. A composite MR score based on brain volume and cGM MTR peak height was correlated with patient cognitive impairment (r = 0.65, p = 0.003). This preliminary study presents a novel approach to quantify AD-related tissue damage in-vivo.

Aged↗
PubMed2001

Emergency stenting to treat neurological complications occurring after carotid endarterectomy.

OBJECTIVES: The purpose of this study was to assess the efficacy of emergency stent implantation for the treatment of perioperative stroke after carotid endarterectomy (CEA). BACKGROUND: Carotid endarterectomy has been proven safe and effective in reducing the risk of stroke in symptomatic and asymptomatic patients with >60% carotid artery stenosis. However, perioperative stroke has been reported in 1.5% to 9% of CEA cases. The management of such a complication is challenging. Recently, percutaneous transluminal carotid angioplasty with stent deployment has emerged as a valuable and alternative strategy for the treatment of carotid artery disease. METHODS: Between April 1998 and February 2000, 18 of the 995 patients (1.8%) who had CEA in our institution experienced perioperative major or minor neurological complications. Of these, 13 patients underwent emergency carotid angiogram and eventual stent implantation, whereas the remaining five had surgery re-exploration. RESULTS: Carotid angiogram was performed within 20+/-10 min and revealed vessel flow-limiting dissection (five cases) or thrombosis (eight cases). Percutaneous transluminal carotid angioplasty with direct stenting (self-expandable stent) was performed in all 13 cases. Angiographic success was 100%. Complete remission of neurological symptoms occurred in 11 of the 13 patients treated by stent implantation and in one of the five patients treated by surgical re-exploration (p = 0.024). CONCLUSIONS: Stent implantation seems to be a safe and effective strategy in the treatment of perioperative stroke complicating CEA, especially when carotid dissection represents the main anatomic problem.

Aged↗
PubMed2001

Fatigue in multiple sclerosis is associated with abnormal cortical activation to voluntary movement--EEG evidence.

Converging evidence is consistent with the view that fatigue in Multiple Sclerosis is independent from pyramidal tract involvement, suggesting a possible involvement of frontal areas. During voluntary movement, changes of the EEG rhythms can be observed over sensorimotor areas. Event-related desynchronization (ERD) of the 10 and 20 Hz frequency bands occurs during motor planning and execution and is followed after movement termination by event-related synchronization (ERS), expressing cortical idling or inhibition. We evaluated the pattern of cortical activation to voluntary movement in MS patients complaining of fatigue assessed using the Fatigue Severity Scale. Fifteen MS patients complaining of fatigue, 18 MS patients without fatigue, and 14 normal controls were studied. The two patients groups were similar for age, sex, disease duration, and were not disabled (score <1.5 at the Expanded Disability Status Scale). Twenty-nine channel EEG was recorded during about 60 self-paced extensions of the right thumb. The onset latency and amount of the contralateral sensorimotor (C3 electrode) 10 and 18--22 Hz ERD were similar in the three groups. ERD was more widespread anteriorly in the fatigue group compared with normal controls (P < 0.01 over Fz electrode). Postmovement contralateral sensorimotor 18--22 Hz ERS was significantly lower in fatigue MS patients compared with normal subjects (P < 0.005) and with nonfatigue MS patients (P = 0.02). These findings are consistent with a central origin of fatigue in MS and indicate cortical dysfunction even during a simple motor task, resulting in hyperactivity during movement execution and failure of the inhibitory mechanisms intervening after movement termination.

Adult↗
PubMed2001

Interplay between methylenetetrahydrofolate reductase gene polymorphism 677C-->T and serum folate levels in determining hyperhomocysteinemia in heart transplant recipients.

BACKGROUND: Homocysteine metabolism is often impaired in heart transplant recipients, and increased total homocysteine plasma levels may constitute a risk factor for the development of heart allograft vascular disease. Although 677C-->T transition in methylenetetrahydrofolate reductase (MTHFR) is associated with increased homocysteine levels in the general population, it is unclear whether MTHFR polymorphism influences homocysteine metabolism after heart transplant. METHODS: Homocysteine, serum folate, renal function, concentrations of cyclosporine and its metabolites, and MTHFR genotype were determined in 57 heart transplant recipients (age, 55 +/- 11 yr; 21% women; time from transplant, 48 +/- 42 months). RESULTS: Forty nine percent of the study population presented with hyperhomocysteinemia. Homocysteine was 17.1 +/- 5.9 micromol/liter, 19.4 +/- 4.9 micromol/liter, and 26.3 +/- 14.2 micromol/liter for genotypes CC, CT, and TT, respectively (p = 0.028, Kruskal-Wallis test). At multivariate analysis, MTHFR genotype was independently associated with homocysteine (p = 0.005). When the study population was divided into 2 groups accordingly to serum folate levels (above/below the median value of 6.1 ng/ml), MTHFR genotype remained a significant predictor of homocysteine only in patients with low serum folate (p = 0.048). CONCLUSIONS: This study demonstrates that hyperhomocysteinemia is frequent in heart transplant recipients and that the 677C-->T transition in the MTHFR gene independently and unfavorably influences homocysteine metabolism in this group of patients. Adequate folate intake may overcome genetic predisposition to hyperhomocysteinemia.

Adult↗
PubMed2001

Abnormal pattern of cortical activation associated with voluntary movement in obsessive-compulsive disorder: an EEG study.

OBJECTIVE: Converging evidence in patients with obsessive-compulsive disorder (OCD) shows abnormalities of prefrontal areas and basal ganglia, which are also involved in motor control. Event-related desynchronization of mu and beta EEG rhythms is considered a correlate of motor activation during motor preparation and execution, followed by cortical idling or inhibition indicated by event-related synchronization. The authors investigated the circuits involved in motor behavior in OCD by using event-related desynchronization/synchronization. METHOD: Data on alpha and beta event-related desynchronization/synchronization with self-paced movement of the right thumb were obtained by using 29-channel EEG in 10 untreated OCD patients and 10 normal subjects. RESULTS: OCD patients showed delayed onset of mu event-related desynchronization with movement preparation and less postmovement beta synchronization, compared to normal subjects. CONCLUSIONS: Delayed event-related desynchronization in OCD is consistent with involvement of structures related to motor programming, such as basal ganglia. Lower levels of postmovement beta synchronization suggest impairment of the inhibitory system in OCD.

Adult↗
PubMed2001

[Familial predisposition to ischemic cardiopathy: role of homocysteine and genetic polymorphism of methylenetetrahydrofolate reductase].

Homocysteine represents a risk factor for coronary artery disease determined not only by nutritional habits, but also by the genetic polymorphism of the enzymes involved in its metabolism (i.e. methylenetetrahydrofolate reductase - MTHFR). However, recent prospective studies questioned the initial evidence of a clear epidemiological and pathogenetic link between homocysteine levels and coronary artery disease. Moreover, the relationships between MTHFR polymorphism and coronary artery disease remain unclear. In this paper, the recent literature analyzing the role of homocysteine and MTHFR polymorphism as a risk factor for coronary artery disease has been reviewed.

Causality↗
PubMed2000

HTLV-II down-regulates HIV-1 replication in IL-2-stimulated primary PBMC of coinfected individuals through expression of MIP-1alpha.

The influence of human T-cell leukemia/lymphoma virus type II (HTLV-II) in individuals also infected with HIV-1 is poorly understood. To evaluate the reciprocal influence of HTLV-II and HIV-1 infection, primary peripheral blood mononuclear cell (PBMC) cultures from coinfected individuals were established in the presence of interleukin 2 (IL-2). In these cultures, the kinetics of HTLV-II replication always preceded those of HIV-1. Noteworthy, the kinetics of HIV-1 production were inversely correlated to the HTLV-II proviral load in vivo and its replication ex vivo. These observations suggested a potential interaction between the 2 retroviruses. In this regard, the levels of IL-2, IL-6, and tumor necrosis factor-alpha (TNF-alpha) were measured in the same coinfected PBMC cultures. Endogenous IL-2 was not produced, whereas IL-6 and TNF-alpha were secreted at levels compatible with their known ability to up-regulate HIV-1 expression. The HIV-suppressive CC-chemokines RANTES, macrophage inflammatory protein-1alpha (MIP-1alpha), and MIP-1beta were also determined in IL-2-stimulated PBMC cultures. Of interest, their kinetics and concentrations were inversely related to those of HIV-1 replication. Experiments were performed in which CD8(+) T cells or PBMCs from HTLV-II monoinfected individuals were cocultivated with CD4(+) T cells from HIV-1 monoinfected individuals separated by a semipermeable membrane in the presence or absence of antichemokine neutralizing antibodies. The results indicate that HTLV-II can interfere with the replicative potential of HIV-1 by up-regulating viral suppressive CC-chemokines and, in particular, MIP-1alpha. This study is the first report indicating that HTLV-II can influence HIV replication, at least in vitro, via up-regulation of HIV-suppressive chemokines. (Blood. 2000;95:2760-2769)

Acquired Immunodeficiency Syndrome↗
PubMed2000

Role of statins in the management of dyslipidemia after cardiac transplant: randomized controlled trial comparing the efficacy and the safety of atorvastatin with pravastatin.

BACKGROUND: Cardiac transplant patients are at increased risk of dyslipidemia, a known pathogenetic factor in chronic rejection. The aim of this study was to compare the efficacy and the safety of treatment with atorvastatin (AT) and treatment with pravastatin (PV) in a population of dyslipidemic transplant patients. METHODS: Thirty-nine transplant patients were randomized to receive a 4-month cycle of therapy with AT or PV, in a cross-over sequence. We analyzed the effects on their lipid profiles using Student t-test for paired data. RESULTS AND CONCLUSION: Atorvastatin was significantly more effective than PV in reducing total cholesterol (33% vs 21%, p < 0.001), LDL cholesterol (45% vs 30%, p = 0.001), and triglycerides (24% vs 7.7%, p < 0.001), at lower doses and with comparable tolerability and safety.

Adult↗
PubMed2000

Electroencephalographic coherence analysis in multiple sclerosis: correlation with clinical, neuropsychological, and MRI findings.

OBJECTIVE: To explore functional corticocortical connections in multiple sclerosis by means of coherence of the EEG, and to evaluate their correlations with the degree of cognitive impairment and with brain lesion load assessed by MRI. METHODS: EEG coherence was studied from 28 patients with clinically definite multiple sclerosis. Ten minutes of resting EEG were recorded with 20 scalp electrodes, with binaural reference. FFT power and coherence were calculated in artifact free epochs of 1 second and compared with values from 22 control subjects of comparable age and sex distribution. Patients also underwent MRI (n=27) and neuropsychological examination (n=21). RESULTS: Compared with controls, patients with multiple sclerosis showed increased theta power in the frontotemporal-central regions (p<0.005). theta Band coherence was decreased between homologous areas (p<0.02). alpha Band coherence was decreased both in the local and long distance connections (p<0.0005). These findings were most striking both in patients with high MRI subcortical lesion load and in patients with cognitive involvement. A significant correlation was found between interhemispheric theta (p=0.02) and alpha (p=0. 017) and anteroposterior alpha (p=0.013) coherence and subcortical MRI lesion load, but not with exclusively periventricular lesion load. CONCLUSIONS: These findings support the hypothesis that cognitive impairment in multiple sclerosis is mostly dependent on involvement of corticocortical connections related to demyelination and/or axonal loss within the white matter immediately underlying the cortex.

Adult↗