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Biomedical subjects

F Federico

Publications and source records attributed to F Federico.

At least 19 recordsLinked to original sources
PubMed2001

Axonal damage in multiple sclerosis plaques: a combined magnetic resonance imaging and 1H-magnetic resonance spectroscopy study.

The purpose of this study was to compare magnetic resonance imaging (MRI) features and proton MR spectroscopy (1H-MRS) patterns of multiple sclerosis (MS) plaques in order to define the metabolic substrate in different lesion subtypes. Combined MRI and single-voxel 1H-MRS investigation was performed in 54 MS patients (47 relapsing remitting (RR) and seven secondary progressive (SP)). Sixty-seven MS lesions were selected. Thirty-seven lesions were Gadolinium (Gd) enhancing (nine isointense and 28 hypointense on pre-contrast T(1)-weighted scans) and 30 Gd unenhancing (six isointense and 24 hypointense on pre- and post-contrast T(1)-weighted scans). Choline (Cho), creatine (Cr), N-acetyl aspartate (NAA) and lactate were evaluated in 1H spectra acquired from MS plaques and from normal white matter (NWM) of 22 neurological controls. MS lesions of RR patients were characterized by a significant increase of Cho/Cr and decrease of NAA/Cr and NAA/Cho ratios. No significant metabolite changes were found in lesions of SP patients. Gd enhancing plaques showed lactate signal with higher frequency (37.8%) than Gd unenhancing plaques (16.7%) (p=0.04). A significant increase of Cho/Cr was found in Gd enhancing lesions when compared to controls (p<0.01), and to Gd unenhancing lesions (p<0.05). In particular, there was evidence of a significant increase of Cho/Cr in pre-contrast T(1) hypointense Gd enhancing lesions (p<0.01 vs. controls). The Gd unenhancing lesions (p<0.01), in particular the T(1) hypointense group (p<0.05), showed a significant decrease of NAA/Cr only when compared to controls. These data confirm that in vivo MRS indicates key pathological features of MS plaques. The increased Cho/Cr ratio found in Gd-enhancing plaques, in particular in the T(1) hypointense lesions, may reflect increased membrane cell turnover. The T(1) hypointense Gd unenhancing plaques better reflect axonal damage, as suggested by the decrease of NAA/Cr. Nevertheless, the lack of statistical differences in NAA/Cr between plaque subgroups suggests that axonal impairment might occur even in the early stages.

Adolescent↗
PubMed2000

Primary hemifacial spasm and arterial hypertension: a multicenter case-control study.

In a case-control study, the authors found that arterial hypertension occurred more frequently among 115 patients with primary hemifacial spasm than among 115 neurologic controls matched for age (+/-5 years), sex, and referral center. The association was not confounded by education level, smoking history, diabetes, or other diseases (adjusted OR 2.64; 95% CI 1.3 to 5.33, p = 0.007). Hypertension was significantly associated with the outcome in the left-sided group (OR 4.0; 95% CI 1.4 to 11.5), but data concerning patients with right-sided spasm were inconclusive (OR 1.05; 95% CI 0.36 to 3.1). In our sample, hypertension either preceded or followed the onset of hemifacial spasm.

Aged↗
PubMed1999

Usefulness of proton magnetic resonance spectroscopy in differentiating parkinsonian syndromes.

Proton magnetic resonance spectroscopy ((1)H-MRS) was performed in patients with a clinical diagnosis of idiopathic Parkinson's disease (IPD), multiple system atrophy (MSA) or progressive supranuclear palsy (PSP) in order to assess metabolic differences between the three groups of patients. Single-volume (1)H-MRS, localized to the lentiform nucleus, was carried out in 19 IPD patients, 14 MSA patients, 11 PSP patients and 12 age-matched healthy subjects. The signals of N-acetylaspartate (NAA), choline-containing compounds (Cho) and creatine-phosphocreatine (Cr) were evaluated as peak area ratios. The NAA/Cho peak ratio was significantly reduced in MSA and in PSP patients compared to IPD patients and to controls. The NAA/Cr peak ratio was significantly reduced in MSA, in PSP and in IPD patients compared to controls, but only in MSA compared to IPD patients. The NAA reduction in the basal ganglia of MSA and PSP patients may reflect a neuronal loss or damage. Single-volume (1)H-MRS may be a useful tool in differentiating MSA and PSP from IPD patients.

Adult↗
PubMed1999

The contribution of (1)H-magnetic resonance spectroscopy in defining the pathophysiology of multiple sclerosis.

Proton magnetic resonance spectroscopy ((1)H-MRS) is considered a suitable investigation technique for obtaining in vivo information on pathological changes in multiple sclerosis (MS) brain. The main betabolites identified are choline-containing compounds, creatine, N-acetylaspartate (NAA), lactate, mobile lipids, myo-inositol, glutamate and glutamine. Proton spectra may be acquired from localized volumes of interest on single MS lesions or from the entire brain by (1)H-MRS imaging. An increase of choline and lipids (markers of demyelination) and the presence of lactate (marker of acute inflammatory reaction) have been demonstrated in active Gd-enhancing MS plaques. A reduction of NAA (marker of neuronal or axonal damage) has been found in inactive MS lesions. The recent evidence of an early NAA decrease in active plaques and in normal appearing white matter suggests that axonal damage is an early event in the evolution of demyelinating lesions. The correlation between NAA decrease and clinical disability conforms that axonal damage has important functional consequences, and indicates that the prevention of irreversible axonal loss might be a major target for the design and the timing of therapeutical strategies.

Axons↗
PubMed1999

Metabolic changes in neuronal migration disorders: evaluation by combined MRI and proton MR spectroscopy.

PURPOSE: To assess the role of 1H-magnetic resonance spectroscopy (MRS) in detecting biochemical abnormalities in neuronal migration disorders (NMDs). METHODS: We performed 1H-MRS studies on 17 brain NMD areas [five polymicrogyria, eight subcortical heterotopia, and four cortical dysplasia on magnetic resonance imaging (MRI)]. The study group consisted of 15 patients, all but one affected by partial epileptic seizures. Spectra were acquired from volumes of interest localized on NMDs and contralateral sides and compared with those obtained on gray and white matter of 18 neurologic controls. RESULTS: NMD lesions were characterized by lower N-acetylaspartate to creatine (NAA/Cr) and choline to Cr (Cho/Cr) ratios than those of the white (p = 0.002 and p = 0.004) and gray matter (p = 0.03 and p = 0.06) of neurologic controls. In addition, the normal-appearing contralateral sides to the NMD lesions showed a significant decrease of Cho/Cr ratio when compared with those of white (p = 0.003) and gray matter (p = 0.05) of neurologic controls. No relation was found between NAA/Cr decrease, EEG abnormalities, and NMD sides, or between NAA/Cr ratios, duration of epilepsy, and frequency of seizures. Lactate signal was detected in the spectra of four patients who had an epileptic seizure a short time before MR examination. CONCLUSIONS: NAA/Cr decrease may be related more to structural and functional alteration of the NMD sides than to epileptic activity in these lesions. Low Cho/Cr may be related to a more extensive diffuse hypomyelination than suggested by the MRI findings. An activation of anerobic glycolysis during and after seizures could account for the presence of lactate. These data confirm that H-MRS is an advanced technique that may provide useful biochemical information in vivo on neurobiologic processes underlying NMDs.

Brain↗
PubMed1999

Primary malignant fibrous histiocytoma of the duodenum.

BACKGROUND/AIM: We report on a case of primary malignant fibrous histiocytoma of the duodenum. METHODS: Report of a case and review of the literature on the occurrence of this tumor in the alimentary tract. RESULTS: The neoplasm was detected incidentally at the time of diagnostic workup for upper gastrointestinal bleeding. Curative surgery using the Whipple procedure was carried out with uneventful postoperative course; no evidence of liver metastases was detected during intraoperative ultrasonography. The patient died of diffuse metastatic liver disease 2 months after surgical resection. Up-to-date review of the literature has added only 3 cases to those previously reported, including that reported by us. CONCLUSIONS: The biological behavior of malignat fibrous histiocytomas is extremely aggressive and mainly conditioned by size and histological grading. The treatment of choice, whenever possible, is based on early and complete surgical excision of the tumor.

Duodenal Neoplasms↗
PubMed1998

Prognostic value of proton magnetic resonance spectroscopy in ischemic stroke.

OBJECTIVE: To determine the correlation between metabolite concentrations and clinical outcome during the acute or subacute phase of ischemic stroke by using single-voxel localized proton magnetic resonance spectroscopy (1H-MRS). SETTING: A university hospital neurologic department. PATIENTS AND METHODS: Combined single-voxel 1H-MRS and magnetic resonance imaging were performed on 26 patients with a recent ischemic stroke (on 8 patients during the first 24 hours after the stroke and on 18 during the first week). For all patients, the signals from N-acetylaspartate, choline-containing compounds, and creatine-phosphocreatine were compared with those on the contralateral side as peak area ratios. The data for 1H-MRS were related to scores on the Scandinavian Stroke Scale and the Barthel Index at a 6-month clinical follow-up. RESULTS: The signals from N-acetylaspartate, choline-containing compounds, and creatine-phosphocreatine were significantly reduced in all infarcted areas (P<.001, P<.001, and P=.003, respectively, Wilcoxon signed rank test). A lactate signal was present in 19 patients. The statistical analysis showed a significant positive correlation between N-acetylaspartate signals and Scandinavian Stroke Scale scores and between reduction of N-acetylaspartate signals and Barthel Index scores (Spearman rank correlation test). Patients in whom lactate was present had Scandinavian Stroke Scale scores significantly lower than patients in the group without lactate (Mann-Whitney U test). CONCLUSION: Single-voxel 1H-MRS performed during the acute or subacute phase of ischemic stroke may provide prognostic information.

Adult↗
PubMed1998

Localised 1H-MR spectroscopy for metabolic characterisation of diffuse and focal brain lesions in patients infected with HIV.

OBJECTIVES: To evaluate the role of proton MR spectroscopy (1H-MRS) in detecting metabolic changes in diffuse or focal lesions in the brain of patients infected with HIV. METHODS: Sixty HIV seropositive patients (25 with HIV related encephalopathies, 20 with toxoplasmosis, eight with progressive multifocal leukoencephalopathies (PMLs), and seven with lymphomas) and 22 HIV seronegative neurological controls were examined with a combined MRI and 1H-MRS technique using a Siemens 1.5 Tesla Magnetom. Spectra (Spin Echo sequence, TE 135 ms) were acquired by single voxel, localised on focal lesions in toxoplasmosis, PML, lymphomas, and HIV encephalopathies and on the centrum semiovale of neurological controls. Choline (Cho), creatine (Cr), N-acetyl aspartate (NAA), lactate, and lipids were evaluated in each spectrum and NAA/Cr, NAA/Cho, and Cho/Cr ratios were calculated. RESULTS: A significant decrease in NAA/Cr and NAA/Cho ratios were found in all HIV diagnostic groups in comparison with neurological controls (p<0.003), suggesting neuronal or axonal damage independent of brain lesion aetiology. However, the NAA/Cr ratio was significantly lower in PML and lymphomas than in HIV encephalopathies (p<0.02) and toxoplasmosis (p<0.05). HIV encephalopathies, lymphomas, and toxoplasmosis showed a significant increase in the Cho/Cr ratio in comparison with neurological controls (p<0.03) without between group differences. The presence of a lipid signal was more frequent in lymphomas (71%) than in other HIV groups (Fisher's test, p=0.00003). The presence of mobile lipid resonance together with a high Cho/Cr ratio in lymphomas may be related to an increased membrane synthesis and turnover in tumour cells. A lactate signal (marker of inflammatory reaction), was found in all but one patient with PML lesions (75%), but had a lower incidence in the other HIV diagnostic groups (Fisher's test, p=0.00024). CONCLUSION: 1H-MRS shows a high sensitivity in detecting brain involvement in HIV related diseases, but a poor specificity in differential diagnosis of HIV brain lesions. Nevertheless, the homogeneous metabolic pattern that characterises PML suggests the usefulness of 1H-MRS as an adjunct to MRI in differentiating CNS white matter lesions, such as HIV encephalopathies, from PML.

AIDS Dementia Complex↗
PubMed1998

Proton magnetic resonance spectroscopy in primary blepharospasm.

Single-volume proton magnetic resonance spectroscopy, localized to basal ganglia, was carried out in 10 patients with primary blepharospasm (PB) to assess the levels of N-acetyl aspartate (NAA), creatine-phosphocreatine, and choline-containing compounds. NAA was reduced significantly in patients compared with control subjects. This result suggests a striatal neuronal loss in PB.

Aged↗
PubMed1997

Proton magnetic resonance spectroscopy in Parkinson's disease and atypical parkinsonian disorders.

Proton magnetic resonance spectroscopy (1H-MRS), localized to the lentiform nucleus, was carried out in 12 patients with idiopathic Parkinson's disease (IPD), seven patients with multiple-system atrophy (MSA), seven patients with progressive supranuclear palsy (PSP), and 10 healthy age-matched controls. The study assessed the level of N-acetylaspartate (NAA), creatine-phosphocreatine (Cr), and choline (Cho) in the putamen and globus pallidus of these patients. NAA/Cho and NAA/Cr ratios were significantly reduced in MSA and PSP patients. No significant difference was found between IPD patients and controls. These results suggest an NAA deficit, due to neuronal loss, in the lentiform nucleus of MSA and PSP patients. 1H-MRS is a noninvasive technique that can provide useful information regarding striatal neuronal loss in basal ganglia of patients with atypical parkinsonian disorders and represents a potential tool for diagnosing these disorders.

Aged↗
PubMed1997

Proton magnetic resonance spectroscopy in Parkinson's disease and progressive supranuclear palsy.

OBJECTIVES: Proton magnetic resonance spectroscopy (1H-MRS) localised to the lentiform nucleus, was carried out in eight patients with idiopathic Parkinson's disease and five patients with progressive supranuclear palsy. The aim of the study was to assess the concentration of N-acetyl-aspartate (NAA), creatine and phosphocreatine (Cr), and choline containing compounds (Cho) in the putamen and globus pallidus of these patients. METHODS: Peak ratios obtained from patients were compared with those from nine healthy age matched controls. RESULTS: NAA/Cho and NAA/Cr ratios were reduced significantly in patients with progressive supranuclear palsy. CONCLUSION: These results suggest an NAA deficit, due to neuronal loss, in the lentiform nucleus of these patients. 1H-MRS is a non-invasive technique that can provide useful information concerning striatal neuronal loss in the basal ganglia of patients with parkinsonian syndromes.

Aged↗
PubMed1997

Pseudo-occlusion of the internal carotid artery: report of 15 cases and review of the literature.

Pseudo-occlusion of the internal carotid artery represents a difficult diagnostic problem. Meticulous investigation is mandatory whenever there is any suspicion of pseudo-occlusion, since it can easily be removed with endoarterectomy. Fifteen patients were selected in the last twelve years from those participating in a prospective study on the natural history of total occlusion of the internal carotid artery. The mean follow-up was 4.2 years (ranging from 1 to 12). Pseudo-occlusion was diagnosed by duplex examination in the presence of a continuous signal with filling in of the spectral waveform window and no pulsatile flow. Arteriography showed a segmental occlusion of the internal carotid artery with reconstitution of flow in the distal portion of the vessel. Operations were performed under general anesthesia with EEG monitoring. Intraluminal shunt was necessary in only one patient. Patch closure of the arteriotomy was performed in two patients. All patients were put on Ticlopidin "sine die" after the operation. No mortality or strokes occurred in the perioperative period. Two patients presented with ipsilateral TIA after 7 months and one year, respectively. We conclude that: the incidence of this disease is low; the performance of duplex scan in combination with arteriography is essential in order to obtain the diagnosis of pseudo-occlusion; a strong suspicion of carotid pseudo-occlusion should always spring to mind when an apparently occluded carotid artery continues to be symptomatic or when, in asymptomatic patients, there is some discordance between angiography and Doppler or duplex scan findings; pseudo-occlusion should be considered an indication for urgent operation only in selected symptomatic patients.

Aged↗
PubMed1996

Prognostic significance of metabolic changes detected by proton magnetic resonance spectroscopy in ischaemic stroke.

Proton magnetic resonance spectroscopy has proved to be useful for monitoring a number of metabolites in cerebral infarction. Combined magnetic resonance imaging and spectroscopy investigations were carried out in 14 patients with a recent ischaemic stroke (< 1 week); follow-up examinations were performed from day 28 to day 252 after stroke. The aim of this study was to assess the correlation between the changes of N-acetyl-aspartate, choline, creatine-phosphocreatine, lactate and clinical evolution measured by the Scandinavian Neurological Scale (SNS). Initially the lactate magnetic resonance signal was present in all patients and the other metabolite contents were significantly reduced (P < 0.001; unpaired t-test) as compared with those on the contralateral side. Spearman's rank correlation test showed a positive correlation between the initial reduction of N-acetyl-aspartate content and the SNS (P < 0.05), and between the final N-acetyl-aspartate content and the SNS (P < 0.001). Our results suggest that serial examination in stroke patients may provide further prognostic information and encourage controlled clinical studies.

Adult↗
PubMed1996

High resolution proton MR spectroscopy of cerebrospinal fluid in MS patients. Comparison with biochemical changes in demyelinating plaques.

Proton magnetic spectroscopy (1H-MRS) investigation was performed on CSF samples of patients with neurological inflammatory diseases including 52 cases of multiple sclerosis (MS). 12 acute idiopathic polyneuropathies, 20 acute meningitides (10 viral and 10 bacterial). Spectra were compared with those acquired in 18 neurological controls. High CSF lactate levels were found in MS patients during clinical exacerbation of relapsing-remitting course (p = 0.036 vs neurological controls). In MS patients with MRI evidence of Gd-enhanced plaques CSF lactate was higher than in patients with MRI inactive plaques (p = 0.017). CSF lactate positivity correlated with number of CSF mononuclear cells in MS patients with clinical activity (p = 0.05) as well as in MS patients with MRI enhancement (p = 0.003). A comparative 1H-MRS investigation in vivo on localized demyelinating areas confirmed an elevated lactate signal in Gd-enhanced (61%) more frequently than in unenhanced (22%) plaques (p = 0.03). MS patients with high lactate signal in active plaques showed high lactate levels in CSF. Increased CSF lactate was found also in patients with acute meningitis and idiopathic polyneuropathy. These data suggest that changes in lactate levels may depend on anaerobic glycolytic metabolism in activated leukocytes during inflammatory diseases. A decrease of CSF formulate levels was found in MS patients during active and inactive clinical phase (p = 0.037, p=0.05 vs neurological controls respectively). Formate changes might be related to a disorder of choline-glycine cycle in MS. 1H-MRS in vivo showed significant increase of choline in acute plaques, whereas a decrease of N-acetyl aspartate was found in chronic plaques; these metabolites are undetectable in CSF. CSF glucose levels were lower in bacterial than in viral meningitis (p = 0.014) and in neurological controls (p = 0.05). These observations suggest that 1H-MRS may be able to detect CSF metabolic impairment in neurological inflammatory diseases. In MS some CSF findings reflect metabolic changes occurring in brain demyelinating areas, and they could be useful foe evaluation of disease activity in different stages of disease evolution.

Adolescent↗