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Biomedical subjects

Antonio Federico

Publications and source records attributed to Antonio Federico.

At least 19 recordsLinked to original sources

OpTiles: an R package for adaptive tiling and methylation variability profiling.

SUMMARY: OpTiles is an R package that dynamically defines tiling windows based on the distribution of sequenced CpGs, addressing the limitations of traditional fixed-tiling approaches in targeted methylation datasets. By integrating CpG density with intra-region methylation variability, it provides a reliability metric and extended functionality for annotating, prioritizing, and interpreting complex methylation data. AVAILABILITY AND IMPLEMENTATION: OpTiles is implemented in R and source code is freely available at https://github.com/fhaive/OpTiles. Data are available on Zenodo at https://doi.org/10.5281/zenodo.16961292.

DNA Methylation↗

Cardiac autonomic nervous system and risk of arrhythmias in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL).

BACKGROUND AND PURPOSE: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited systemic microangiopathy with prevalently cerebral manifestations. Among the causes of death, sudden unexpected death seems to occur in a significant number of CADASIL patients. Because potential causes of sudden unexpected death may include cardiac arrhythmias and myocardial infarction, we evaluated risk factors for life-threatening arrhythmias, such as reduced heart rate variability, sympathetic overactivity and QT interval (QTc) prolongation, in 23 CADASIL patients. The relationship of these changes with brain MRI pattern was also investigated. METHODS: Frequency domain measures of heart rate variability (10 minutes recordings) and QTc interval were recorded in 23 CADASIL patients (17 males, 6 females) and 22 healthy age- and sex-matched control subjects. The following heart rate variability spectral parameters were considered at rest during spontaneous and controlled breathing (Cb): total power, very-low-frequency component, low-frequency component, high-frequency component, low-frequency/high-frequency ratio, and Cb-total power, Cb-very-low-frequency component, Cb-low-frequency component, Cb-high-frequency component, Cb-low-frequency/high-frequency ratio. R-to-R wave and QTc interval were also analyzed. All data were statistically compared between CADASIL and control subjects. Conventional brain MRI was performed in patients with CADASIL and T1-weighted and T2-weighted lesion volumes, and were compared with each spectral component of the tachogram. RESULTS: During spontaneous and controlled breathing, total power spectrum and all spectral components (very low frequency component, high-frequency component, low-frequency component) of heart rate variability were significantly reduced in CADASIL patients with respect to controls (P<0.05). The low-frequency/high-frequency component ratio was significantly higher in CADASIL patients than in controls. No significant correlation between heart rate variability spectral parameters and other variables including total brain T2-weighted and T1-weighted lesion volumes were observed in CADASIL subjects. CONCLUSIONS: We found a statistically significant reduction in all frequency domain parameters of heart rate variability associated with a higher low frequency/high frequency ratio for CADASIL patients with respect to normal subjects. These data are consistent with autonomic derangement and suggests that CADASIL patients may be at risk for life-threatening arrhythmias. This could at least in part explain their higher recurrence of sudden unexpected death and should be taken into account in planning therapy.

Adult↗

Acute metabolic brain changes following traumatic brain injury and their relevance to clinical severity and outcome.

BACKGROUND: Conventional MRI can provide critical information for care of patients with traumatic brain injury (TBI), but MRI abnormalities rarely correlate to clinical severity and outcome. Previous magnetic resonance spectroscopy studies have reported clinically relevant brain metabolic changes in patients with TBI. However, these changes were often assessed a few to several days after the trauma, with a consequent variation of the metabolic pattern due to temporal changes. METHODS: Proton magnetic resonance spectroscopic imaging (1H-MRSI) examinations were performed in 10 patients with TBI 48-72 h after the trauma, to obtain early measurements of central brain levels of N-acetylaspartate (NAA), choline (Cho), creatine (Cr) and lactate (La). Metabolite values were expressed as ratios to (1) a metabolic pattern, given by the sum of the resonance intensities of all metabolites detected in the same voxel and (2) intravoxel Cr. RESULTS: NAA ratios were found to be significantly lower in patients with TBI than in normal controls. In contrast, Cho ratios were significantly higher in patients with TBI than in normal controls. Increased La levels were found in 5 of 10 patients with TBI. Both NAA and La values correlated closely with those of the Glasgow Coma Scale at presentation (r = 0.73 and -0.62, respectively; p<0.01 for both) and the Glasgow Outcome Scale at 3 months (r = -0.79 and 0.79, respectively; p<0.01 for both). CONCLUSION: Spectroscopic measures of neuro-axonal damage occurring soon after a brain trauma are clinically relevant. Significant increases in cerebral La level also may be detected when 1H-MRSI is performed early after the trauma and, at this stage, can represent a reliable index of injury severity and disease outcome in patients with TBI.

Adult↗

Brain damage as detected by magnetization transfer imaging is less pronounced in benign than in early relapsing multiple sclerosis.

The trend to start disease-modifying therapy early in the course of multiple sclerosis makes it important to establish whether the benign form is a real entity. In previous studies, measures of magnetization transfer (MT) ratio (MTr) have been shown to provide good estimates of the amount of tissue damage occurring in multiple sclerosis brains. Thus, with the hypothesis that if benign multiple sclerosis patients were really benign, sensitive measures of subtle tissue damage would be less pronounced in these patients than in very early relapsing-remitting (RR) multiple sclerosis patients. We carried out conventional MRI and MT imaging in 50 patients with benign multiple sclerosis [defined as having Kurtzke Expanded Disability Status Score (EDSS) <3 and disease duration >15 years] and in 50 early RR patients selected to have similar disability (EDSS <3) and short disease duration (<3 years). Data were compared with those of 32 demographically-matched normal controls. We used a fully automated procedure to measure lesional-MTr, perilesional-MTr, normal-appearing white matter (NAWM) MTr and cortical-MTr. We found that, after correction for common effects of age, lesional-MTr and perilesional-MTr of benign patients were significantly (P < 0.0001) lower than WM of normal controls, but significantly (P < 0.0001) higher than corresponding tissues of RR patients. In NAWM and cortex, MTr values of benign patients were similar to those of normal controls (P > 0.5) and significantly higher than those of the RR patients (P < 0.0001 and P < 0.01, respectively). Similar differences in MTr measures between benign and RR patients were found when patient groups were selected to have no disability (EDSS < or = 2) and, for benign multiple sclerosis, very long disease duration (>20 years) or when both groups were matched for high lesion load (T2-weighted lesion volume >10 cm3). We conclude that lesional and non-lesional MTr values can be significantly less pronounced in benign multiple sclerosis than in a cohort of RR patients at their earliest disease stages, suggesting that brain tissue damage is milder in benign multiple sclerosis than in early RR disease. This can be due to an extraordinary beneficial response to demyelination of benign patients and may represent the evidence that benign multiple sclerosis truly exists and might be differentiated from other forms of this illness.

Adult↗

Cortical damage in brains of patients with adult-form of myotonic dystrophy type 1 and no or minimal MRI abnormalities.

OBJECTIVE: To evaluate, by using quantitative MRI metrics, subtle cortical changes in brains of patients with the adult form of myotonic dystrophy type I (DM1) who showed no or minimal abnormalities on MRI. BACKGROUND: DM1 is an autosomal dominant multisystem disorder caused by the expansion of CTG repeats in the myotonic dystrophy-protein kinase gene. Mild to severe involvement of the CNS can be part of the clinical features of the disease. Several MRI studies have demonstrated that both focal white matter (WM) lesions and diffuse grey matter atrophy can be found in the brains of DM1 patients. However, whether these two processes are related or may occur independently is not clear. DESIGN/METHODS: Ten genetically-proven DM1 patients who showed no or minimal abnormalities on MRI underwent a new brain MRI examination to obtain computerized measures of total and regional brain volumes normalized to head size and regional measurements of the magnetization transfer ratio (MTr). RESULTS: Normalized brain volumes (NBV) were significantly (p < 0.0001) lower in DM1 subjects than in a group of age- and sex-matched normal controls. Normalized cortical volumes (NCV) also were lower (p = 0.003) in DM1 subjects than in normal controls, whereas normalized WM volumes were not different between the two groups (p = 0.3). In agreement with this, values of MTr in the neocortex (cortical-MTr) were significantly (p = 0.006) lower in DM1 patients than in normal controls and this difference was not found in the WM tissue (p = 0.8). CONCLUSIONS: Neocortical damage seems to be evident in the absence of visible WM lesions suggesting that a neocortical pathology, unrelated to WM lesion formation, occurs in DM1 brains.

Adult↗

Spastic paraplegia with thin corpus callosum: description of 20 new families, refinement of the SPG11 locus, candidate gene analysis and evidence of genetic heterogeneity.

We studied 20 Mediterranean families (40 patients) with autosomal recessive hereditary spastic paraplegia and thin corpus callosum (ARHSP-TCC, MIM 604360) to characterize their clinical and genetic features. In six families (17 patients) of Algerian Italian, Moroccan, and Portuguese ancestry, we found data consistent with linkage to the SPG11 locus on chromosome 15q13-15, whereas, in four families (nine patients of Italian, French, and Portuguese ancestry) linkage to the SPG11 locus could firmly be excluded, reinforcing the notion that ARHSP-TCC is genetically heterogeneous. Patients from linked and unlinked families could not be distinguished on the basis of clinical features alone. In SPG11-linked kindred, haplotype reconstruction allowed significant refinement to 6 cM, of the minimal chromosomal interval, but analysis of two genes (MAP1A and SEMA6D) in this region did not identify causative mutations. Our findings suggest that ARHSP-TCC is the most frequent form of ARHSP in Mediterranean countries and that it is particularly frequent in Italy.

Adolescent↗

Neocortical volume decrease in relapsing-remitting multiple sclerosis with mild cognitive impairment.

The aim of the study was to assess neocortical changes and their relevance to cognitive impairment in early relapsing-remitting multiple sclerosis (RRMS). Conventional magnetic resonance was acquired in 41 RRMS patients and 16 demographically matched normal controls (NC). An automated analysis tool was used to obtain measures of cortical brain volumes normalized for head size. Neuropsychological performance of MS patients was assessed through the Rao's Brief Repeatable Battery. We identified 18 cognitively preserved (MS-cp) and 23 cognitively impaired (MS-ci) MS patients. Values of normalized cortical volumes (NCV) in the whole MS sample were lower than those in the NC group (p=0.01). MS-ci patients showed NCV values lower (p=0.02) than did both MS-cp patients and NC. Moreover, we found a positive correlation between NCV values and measures of verbal memory (r=0.51, p=0.02), verbal fluency (r=0.51, p=0.01) and attention/concentration (r=0.65, p<0.001) in MS-ci patients. Furthermore, NCV values were significantly decreased in patients who scored lower on a greater number of tests (r=-0.58, p<0.01) in the MS-ci group. Only MS-ci patients had cortical atrophy significantly correlated with a poorer neuropsychological performance. Grey matter pathology may contribute to the development of cognitive impairment in MS from the earliest stages of the disease.

Adult↗

Diffuse structural and metabolic brain changes in Fabry disease.

OBJECTIVES: To assess structural and metabolic brain changes in subjects affected by Fabry disease (FD) or carrying the disease mutation. BACKGROUND: FD is an X-linked metabolic disorder due to alpha-galactosidase A deficiency, which leads to storage of glycosphingolipids in many tissues and organs. Previous MR studies have shown structural and metabolic brain abnormalities in FD patients. It is not clear, however, whether tissue damage can be seen in both the brains of hemizygous and heterozygous and whether quantitative MR metrics are useful to monitor disease evolution. DESIGN/METHODS: We studied 4 males and 4 females with FD. Each subject underwent brain proton MRI/MR spectroscopic imaging (MRSI) examinations to obtain measures of total brain volumes, total brain lesion volumes, magnetization transfer ratios (MTr) in WM and central brain levels of N-acetylaspartate (NAA) to creatine (Cr). A second MR examination was performed in five subjects after 2 years. RESULTS: Focal WM lesions were found in 2 males and 1 female. The MTr values were always low in the WM lesions of FD subjects (p < 0.001) and also were low in the normal-appearing WM of 2 affected males. Total brain volumes were never decreased in FD subjects. Brain NAA/Cr values were significantly (p = 0.005) lower in FD subjects than in normal controls and correlated closely with Rankin scale measures (r = -0.79). On follow-up examinations, no significant MR changes were found. However, the small changes in NAA/Cr correlated closely with changes in Rankin scores (r = -0.86). CONCLUSIONS: Subtle structural and metabolic tissue damage can extend beyond WM lesions in FD subjects. Diffuse brain NAA/Cr decrease can be found in FD subjects in relation to the degree of their CNS involvement and its evolution over time.

Adult↗

Diffuse metabolic changes in the brain of patients with familial amyloid polyneuropathy. A proton MRSI study.

OBJECTIVES: To assess brain metabolic abnormalities in patients with familial amyloid polyneuropathy (FAP) due to the transthyretin (TTR) gene mutations. BACKGROUND: The TTR-FAP has variable phenotypic expression, which includes abnormalities of the central nervous system (CNS). Several conventional MRI studies have shown brain abnormalities, probably secondary to amyloid accumulation in leptomeningeal and subarachnoid vessels. However, TTR-related amyloid deposits do not seem to significantly affect the brain parenchyma and a prominent CNS impairment is considered to be rare in TTR amyloidosis. METHODS: We performed proton MR spectroscopic imaging (1H-MRSI) in the central brain of four unrelated TTR-FAP patients with either minimal or no signs of neurological involvement and eight age- and sex-matched normal controls (NC). Metabolic changes were assessed in the entire volume of interest (VOI) and in the frontal, periventricular and posterior white matter (WM). RESULTS: Conventional MRI was normal in 2 patients and showed minimal WM lesions in the remaining 2 patients. 1H-MRSI showed N-acetylaspartate to creatine ratio (NAA/Cr) decreases in the central brain VOI in all TTR-FAP patients (p < 0.005). These NAA/Cr decreases were homogeneous in all WM regions (p < 0.05 for all). CONCLUSIONS: 1H-MRSI findings suggest that diffuse metabolic changes, probably related to axonal damage, are present in brains of TTR-FAP patients even when they have no or minimal clinical and MRI signs of CNS involvement. The mechanism leading to sub-clinical metabolic brain changes needs to be identified.

Adult↗

A new missense mutation in caveolin-3 gene causes rippling muscle disease.

Mutations of the Cav-3 gene are associated with distinct, sometimes overlapping muscle disease phenotypes. We report a new Italian family with autosomal dominant rippling muscle disease. Immunocytochemical analysis of muscle showed a deficit of caveolin-3 protein and molecular genetic analysis showed a novel mutation of the Cav-3 gene.

Adult↗

Videolaparoscopy as rescue therapy and placement of peritoneal dialysis catheters: a thirty-two case single centre experience.

BACKGROUND: Malfunction of the peritoneal catheter is a frequent complication in peritoneal dialysis (PD). Videolaparoscopy is a minimal invasive technique that allows rescue therapy of malfunctioning catheters and consecutive immediate resumption of PD. Furthermore, Tenckhoff catheters can be safely positioned in patients with previous abdominal surgery. We analysed the clinical diagnosis, videolaparoscopic treatment and the outcome of PD patients on whom videolaparoscopic interventions had been performed at our centre. METHODS: Thirty-two cases of videolaparoscopic interventions were performed for salvage of malfunctioning peritoneal catheters, implantation and abdominal surgical interventions in 25 PD patients. The videolaparoscope was inserted through a mini-laparotomy site of 15 mm diameter which was closed with purse-string sutures at the end of the intervention. RESULTS: Videolaparoscopy was used in 21 cases of catheter malfunction mostly due to omental wrapping (12 cases) and dislocation (five cases). In eight patients with previous surgical abdominal interventions, laparoscopic placement of the PD catheter was performed. In two cases the gall bladder was removed. One case of intestinal occlusion was evaluated laparoscopically in an attempt to minimize invasive surgery. Leakage of the peritoneal fluid presented the only complication caused by insufficient closure of one mini-laparotomy site. Minimal follow-up time of rescued catheters was 5 months. Videolaparoscopy prolonged PD catheter function by a median of 163 days (range 5-1469 days). CONCLUSIONS: Videolaparoscopy prolongs peritoneal catheter survival by treating directly the causes of malfunction. In patients with preceding abdominal interventions, the PD catheter can be placed safely even in cases necessitating surgical preparation like adhesiolysis.

Adult↗

Imaging brain damage in first-degree relatives of sporadic and familial multiple sclerosis.

OBJECTIVE: Our objective was to assess brain damage in first-degree relatives of patients with sporadic and familial multiple sclerosis (MS). METHODS: Asymptomatic first-degree relatives of sporadic (sMS, n = 152) and familial MS (fMS, n = 88) and healthy volunteers (NC, n = 56) underwent brain MRI and magnetization transfer (MT) imaging on a mobile MR scan. On MR examinations, we visually assessed white matter (WM) lesions and quantified WM lesion volumes, brain volumes, and MT ratio (MTr) in lesions and normal-appearing WM (NAWM). RESULTS: A lesional MR pattern similar to that of MS patients was found in 4% sMS and 10% fMS. In these WM lesions, MTr was lower (p < 0.0001) than in the WM of NC. In contrast, there was no difference in NAWM-MTr and brain volume values between the three groups. INTERPRETATION: Focal brain abnormalities indistinguishable from those of MS occur in asymptomatic first-degree relatives of MS patients. These are twice more frequent in fMS than in sMS but do not lead to the widespread tissue damage commonly found in MS patients. Although there is a genetic susceptibility to develop brain abnormalities suggestive of focal demyelination in first-degree relatives of MS patients, other factors are probably critical for the development of a diffuse, clinically relevant, pathology.

Adult↗

Physiology and pathology of notch signalling system.

Notch proteins encode a family of transmembrane receptors that are part of a signalling transduction system known as Notch signalling, an extremely conserved and widely used mechanism regulating programs governing growth, apoptosis and differentiation in metazoans. Notch signalling begins when the Notch receptor binds ligands and ends when the Notch intracellular domain enters the nucleus and activates transcription of target genes. This core pathway is subjected to a wide array of regulatory influences and protein-protein interactions and is correlated with other signalling pathway. This review will summarize recent findings concerning the physiology and pathology of Notch signalling in vascular development and homeostasis. Moreover, the clinical phenotypes of Notch3 signalling system pathology will be described, with particular regard to CADASIL (Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy) for which the most recent pathogenetic hypotheses are reported.

Animals↗

Cerebrospinal fluid tau, A beta, and phosphorylated tau protein for the diagnosis of Alzheimer's disease.

The diagnosis of AD is still largely based on exclusion criteria of secondary causes and other forms of dementia with similar clinical pictures, than the diagnostic accuracy of AD is low. Improved methods of early diagnosis are needed, particularly because drugs treatment is more effective in the early stages of the disease. Recent research focused the attention to biochemical diagnostic markers (biomarkers) and according to the proposal of a consensus group on biomarkers, three candidate CSF markers reflecting the pathological AD processes, have recently been identified: total tau protein (t-tau), amyloid beta(1-42) protein (A beta42), and tau protein phosphorylated at AD-specific epitopes (p-tau). Several articles report reduced CSF levels of A beta42 and increased CSF levels of t-tau and p-tau in AD; the sensitivity and specificity of these data are able for discrimination of AD patients from controls. However, the specificity for other dementias is low. According to the literature analysis reported in the present review, we can conclude that the combination of the CSF markers and their ratios may significantly increase the specificity and the accuracy of AD diagnosis.

Alzheimer Disease↗

Rapidly progressive neurodegeneration in a case with the 7472insC mutation and the A7472C polymorphism in the mtDNA tRNA ser(UCN) gene.

The authors report the clinical, neuroimaging, muscle biopsy and mtDNA findings in a patient affected by bilateral hearing loss and mental retardation since infancy, presenting at age 31 years with a rapid deterioration of mental status and ataxia leading to vegetative condition and death at the age of 32 years. Clinical and genetic studies have been also performed in the mother, affected by neurosensorial hearing loss. Muscle biopsy showed severe mitochondrial alterations in the propositus and evidence of mitochondrial alterations in his mother. Direct mtDNA sequencing in all family members revealed the known 7472insC mutation and the recently described A7472C sequence variation in the tRNA(Ser(UCN))gene. RFLP-PCR confirmed the heteroplasmic nature of the two mutations and failed to find the second transversion in 200 controls. The percentage of mutant genomes harbouring 7472insC ranged from 3 to 7% in asymptomatic family members to 70% in the proband and his mother, whereas the percentage of A7472C mutant genomes was about 90% in all maternal relatives except the proband (56%) and his sister (5%). In conclusion, this is the first report of a rapidly progressive encephalopathy in association with the 7472insC mutation in mtDNA, combined with an A>C variation at the same nucleotide with a possible suppression effect on the pathogenic mutation.

Adult↗

Dysautonomic achalasia in two siblings with Sandhoff disease.

Two siblings in their sixth decade with chronic Type II GM2 gangliosidosis developed progressive dysphagia in addition to chronic motor neuron disease and autonomic nervous system (ANS) involvement. Esophageal achalasia was diagnosed in both patients. It is suggested that this esophageal motor disorder may be a manifestation of the neurovegetative system disorder due to alteration of ganglioside metabolism.

Autonomic Nervous System Diseases↗

Blood oxygenation level dependent contrast resting state networks are relevant to functional activity in the neocortical sensorimotor system.

The relevance of correlations between blood oxygenation level dependent (BOLD) signal changes across the brain acquired at rest (resting state networks, or RSN) to functional networks was tested using two quantitative criteria: (1) the localisation of major RSN correlation clusters and the task-related maxima defined in BOLD fMRI signal changes from the same subjects; and (2) the relative hemispheric lateralisation (LI) of BOLD fMRI signal changes in sensorimotor cortex. RSN were defined on the basis of signal changes correlated with that of a "seed" voxel in the primary sensorimotor cortex. We found a generally close spatial correspondence between clusters of correlated BOLD signal change in RSN and activation maxima associated with hand movement. Conventional BOLD fMRI during active hand movement showed the expected wide variation in relative hemispheric lateralisation of LI for sensorimotor cortex across the subjects. There was a good correlation between LIs for the active hand movement task and the RSN (r=0.74, p<0.001). The RSN thus define anatomically relevant regions of motor cortex and change with functionally relevant variations in hemispheric lateralisation of sensorimotor cortical interactions with hand movement.

Adult↗