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Biomedical subjects

Arturo Brunetti

Publications and source records attributed to Arturo Brunetti.

12 recordsLinked to original sources
PubMed2006

Acute appendicitis: diagnostic value of nonenhanced CT with selective use of contrast in routine clinical settings.

The purposes of this study were to determine the (1) frequency with which nonenhanced computed tomography (CT) (NECT) permits conclusive diagnosis of acute appendicitis, (2) accuracy of NECT when findings are conclusive, and (3) overall accuracy of a CT protocol consisting of NECT with selective use of contrast. Five hundred and thirty-six patients underwent a NECT protocol with selective use of contrast. Diagnostic accuracy was then determined separately for (1) patients with conclusive initial NECT, (2) patients with inconclusive initial NECT, and (3) all patients. NECT was conclusive on initial interpretation in 404/536 patients and inconclusive in 132/536. Of 132 inconclusive studies, 126 were repeated with contrast (intravenous, oral or rectal). Sensitivity, specificity, and positive and negative predictive value for diagnosis of acute appendicitis were (1) 90%, 96.0%, 84.8%, and 97.4% in patients with conclusive NECT (n = 404); (2) 95.6%, 92.3%, 73%, and 99% in patients with inconclusive NECT followed by repeat CT with contrast; and (3) 91.3%, 95%, 82%, and 98% in all patients. The initial diagnosis of appendicitis may be made by NECT in 75% of patients, with contrast administration reserved for inconclusive NECT studies.

Adolescent↗
PubMed2006

Essential roles for Fe65, Alzheimer amyloid precursor-binding protein, in the cellular response to DNA damage.

Fe65 interacts with the cytosolic domain of the Alzheimer amyloid precursor protein (APP). The functions of the Fe65 are still unknown. To address this point we generated Fe65 knockout (KO) mice. These mice do not show any obvious phenotype; however, when fibroblasts (mouse embryonic fibroblasts), isolated from Fe65 KO embryos, were exposed to low doses of DNA damaging agents, such as etoposide or H2O2, an increased sensitivity to genotoxic stress, compared with wild type animals, clearly emerged. Accordingly, brain extracts from Fe65 KO mice, exposed to non-lethal doses of ionizing radiations, showed high levels of gamma-H2AX and p53, thus demonstrating a higher sensitivity to X-rays than wild type mice. Nuclear Fe65 is necessary to rescue the observed phenotype, and few minutes after the exposure of MEFs to DNA damaging agents, Fe65 undergoes phosphorylation in the nucleus. With a similar timing, the proteolytic processing of APP is rapidly affected by the genotoxic stress: in fact, the cleavage of the APP COOH-terminal fragments by gamma-secretase is induced soon after the exposure of cells to etoposide, in a Fe65-dependent manner. These results demonstrate that Fe65 plays an essential role in the response of the cells to DNA damage.

Amyloid beta-Protein Precursor↗
PubMed2006

Neuropsychological assessment, quantitative MRI and ApoE gene polymorphisms in a series of MS patients treated with IFN beta-1b.

Few trials issued the effect of disease-modifying medications on cognitive functions in multiple sclerosis. We designed an open-label longitudinal study to evaluate, during 2 years, cognitive performance and its relationship with MRI data and ApoE polymorphism findings in a group of relapsing-remitting (RR) multiple sclerosis (MS) Interferon (IFN) beta-1b-treated patients (median age 30 years, median disease duration 3.4 years). Complete neuropsychological battery was grouped into attention, information learning/memory, language and visuo-spatial functions. Fifty-two patients (33 females) were enrolled in the study. Six patients (11.5%) dropped out, mainly due to side effects. At baseline neuropsychological evaluation, we found 54% normal, 42% mildly impaired and 4% moderately impaired patients. At 2 years follow-up, cognitive status was stable in 65%, improved in 33% and worsened in 2% of patients. No significant relations were found between global cognitive outcome vs. EDSS change, clinical disease activity, MRI data or ApoE gene polymorphisms over the 2 years follow-up. EDSS and MRI fractional volumes were found to correlate with the performance at single tests. Twenty-one patients (45.6%) showed active MRI scans throughout the study, without any worsening at the corresponding neuropsychological examination. This ongoing trial suggests a possible beneficial effect of IFN beta-1b treatment on cognitive functions in RRMS patients. Extension of follow-up and further data analyses are needed to confirm and clarify these findings.

Adolescent↗
PubMed2005

Lack of the architectural factor HMGA1 causes insulin resistance and diabetes in humans and mice.

Type 2 diabetes mellitus is a widespread disease, affecting millions of people globally. Although genetics and environmental factors seem to have a role, the cause of this metabolic disorder is largely unknown. Here we report a genetic flaw that markedly reduced the intracellular expression of the high mobility group A1 (HMGA1) protein, and adversely affected insulin receptor expression in cells and tissues from four subjects with insulin resistance and type 2 diabetes. Restoration of HMGA1 protein expression in subjects' cells enhanced INSR gene transcription, and restored cell-surface insulin receptor protein expression and insulin-binding capacity. Loss of Hmga1 expression, induced in mice by disrupting the Hmga1 gene, considerably decreased insulin receptor expression in the major targets of insulin action, largely impaired insulin signaling and severely reduced insulin secretion, causing a phenotype characteristic of human type 2 diabetes.

3' Untranslated Regions↗
PubMed2005

CT appearance of the normal appendix in adults.

The aims of this study were to identify (1) the normal range of the appendix on computed tomography (CT), (2) the correlation of patient age and sex with the visibility and appearance of the appendix on CT, and (3) the normal variations in wall thickness, intraluminal content, and location of the appendix. Three hundred seventy-two outpatients underwent abdominopelvic CT. The scans were reviewed on the picture archiving and communication system and appendiceal outer-to-outer wall diameter, wall thickness, location, content and its correlation with appendix diameter were analyzed. The appendix was visualized in 305/372 patients. Its location relative to the cecum was highly variable. The diameter range was 3-10 mm; in 42% of cases the diameter was greater than 6 mm. When the intraluminal content (185/305) was visualized, the diameter was slightly superior to the mean (p=0.0156). In 329 CT scans in which oral contrast material was given, the appendix was filled by contrast material in 74/329 patients. The appendix wall thickness was measurable in 22/305 patients (average 0.15 cm). There is significant overlap between the normal and abnormal CT appearance of the appendix. Consequently the diagnosis of acute appendicitis should be based not only on the appearance of the appendix but also on the presence of secondary signs.

Administration, Oral↗
PubMed2004

Reduced striatal [123 I]FP-CIT binding in SCA2 patients without parkinsonism.

Degeneration of substantia nigra has been described in spinocerebellar ataxia type 2 (SCA2). In this study, dopamine transporter (DAT) density with [123 I]FP-CIT SPECT was studied in six SCA2 patients with no parkinsonian signs, six Parkinson's disease (PD) patients, and six controls. Marked striatal DAT loss was found in both SCA2 and PD patients. However, a more severe reduction in the caudate and a higher putamen to caudate ratio distinguished SCA2 from PD patients, suggesting a more uniform nigrostriatal impairment in SCA2. Striatal DAT density of SCA2 patients correlated with the severity of cerebellar ataxia.

Adult↗
PubMed2004

Integrated software for the analysis of brain PET/SPECT studies with partial-volume-effect correction.

UNLABELLED: We present software for integrated analysis of brain PET studies and coregistered segmented MRI that couples a module for automated placement of regions of interest (ROI) with 4 alternative methods for partial-volume-effect correction (PVEc). The accuracy and precision of these methods have been measured using 4 simulated (18)F-FDG PET studies with increasing degrees of atrophy. METHODS: The software allows the application of a set of labels, defined a priori in the Talairach space, to segmented and coregistered MRI. Resulting ROIs are then transferred onto the PET study, and corresponding values are corrected according to the 4 PVEc techniques under investigation, providing corresponding corrected values. To evaluate the PVEc techniques, the software was applied to 4 simulated (18)F-FDG PET studies, introducing increasingly larger experimental errors, including errors in coregistration (0- to 6-pixel misregistration), segmentation (-13.7% to 14.1% gray matter [GM] volume change) and resolution estimate errors (-16.9% to 26.8% full-width-at-half-maximum mismatch). RESULTS: Even in the absence of segmentation and coregistration errors, uncorrected PET values showed -37.6% GM underestimation and 91.7% WM overestimation. Voxel-based correction only for the loss of GM activity as a result of spill-out onto extraparenchymal tissues left a residual underestimation of GM values (-21.2%). Application of the method that took into account both spill-in and spill-out effects between any possible pair of ROIs (R-PVEc) and of the voxel-based method that corrects also for the WM activity derived from R-PVEC (mMG-PVEc) provided an accuracy above 96%. The coefficient of variation of the GM ROIs, a measure of the imprecision of the GM concentration estimates, was 8.5% for uncorrected PET data and decreased with PVEc, reaching 6.0% for mMG-PVEc. Coregistration errors appeared to be the major determinant of the imprecision. CONCLUSION: Coupling of automated ROI placement and PVEc provides a tool for integrated analysis of brain PET/MRI data, which allows a recovery of true GM ROI values, with a high degree of accuracy when R-PVEc or mMG-PVEc is used. Among the 4 tested PVEc methods, R-PVEc showed the greatest accuracy and is suitable when corrected images are not specifically needed. Otherwise, if corrected images are desired, the mMG-PVEc method appears the most adequate, showing a similar accuracy.

Brain↗
PubMed2004

Clinical impact of correlative [123I]-FP-CIT brain imaging and neurological findings in suspect Parkinson's disease.

PURPOSE: Here we report our experience in a general hospital setting using [(123)I]-FP-CIT SPECT to diagnose patients with suspect Parkinson's disease (PD). MATERIALS AND METHODS: Thirty consecutive patients (19M, 11W, mean age: 61+/-13 years) were prospectively studied. Patients underwent MRI (27) at 1.5T or CT (3) when MRI was contraindicated, to rule out focal brain abnormalities. Motor and cognitive function were evaluated by neurologists with UPDRS and Hoehn e Yahr Scale. [(123)I]-FP-CIT striatal uptake, assessed with SPECT, was classified as normal, non-diagnostic, abnormal (unilateral or bilateral). Imaging results (SPECT+MRI) were correlated with the neurological findings. RESULTS: In 5 patients the [(123)I]-FP-CIT brain SPECT was normal, suggesting that their symptoms could be related to a benign disorder such as essential tremor. Two patients had non-diagnostic [(123)I]-FP-CIT brain SPECT, with MRI/CT findings compatible with subcortical cerebrovascular disease. In the remaining 23 patients abnormal striatal [(123)I]-FP-CIT uptake correlated with neurological findings, significantly increasing the probability of Parkinson's disease. In these patients MRI/CT scans were normal, or showed a mild BA, or mild cerebral vascular disease (mild CVD). CONCLUSIONS: Our results suggest that [(123)I]-FP-CIT scan could be used routinely in clinical practice to support the diagnosis of PD and to differentiate between other conditions. Moreover, FP-CIT could significantly impact treatment selection and follow-up of these patients.

Aged↗
PubMed2003

Brain tissue volume changes in relapsing-remitting multiple sclerosis: correlation with lesion load.

The aim of this study was to simultaneously measure in vivo volumes of gray matter (GM), normal white matter (WM), abnormal white matter (aWM), and cerebro-spinal fluid (CSF), and to assess their relationship in 50 patients with relapsing-remitting multiple sclerosis (RR-MS) (age range, 21-59; mean EDSS, 2.5; mean disease duration, 9.9 years), using an unsupervised multiparametric segmentation procedure applied to brain MR studies. Tissue volumes were normalized to total intracranial volume providing corresponding fractional volumes (fGM, faWM, fWM, and fCSF), subsequently corrected for aWM-related segmentation inaccuracies and adjusted to mean patients' age according to age-related changes measured in 54 normal volunteers (NV) (age range 16-70). In MS patients aWM was 23.8 +/- 29.8 ml (range 0.4-138.8). A significant decrease in fGM was present in MS patients as compared to NV (49.5 +/- 3.2% vs 53.3 +/- 2.1%; P < 0.0001), with a corresponding increase in fCSF (13.0 +/- 3.8% vs 9.1 +/- 2.4%; P < 0.0001). No difference could be detected between the two groups for fWM (37.5 +/- 2.6% vs 37.6 +/- 2.2%). faWM correlated inversely with fGM (R = -0.434, P < 0.001 at regression analysis), and directly with fCSF (R = 0.473, P < 0.001), but not with fWM. There was a significant correlation between disease duration and EDSS, while no relationship was found between EDSS or disease duration and fractional volumes. Brain atrophy in RR-MS is mainly related to GM loss, which correlates with faWM. Both measures do not appear to significantly affect EDSS, which correlates to disease duration.

Adult↗
PubMed2002

Stereotaxy-based regional brain volumetry applied to segmented MRI: validation and results in deficit and nondeficit schizophrenia.

A method for postprocessing of segmented routine brain MRI studies providing automated definition of major structures (frontal, parietal, occipital, and temporal lobes; cerebellar hemispheres; and lateral ventricles) according to the Talairach atlas is presented. The method was applied to MRI studies from 25 normal subjects (NV), 14 patients with deficit schizophrenia (DS), and 14 with nondeficit schizophrenia (NDS), to evaluate their gray matter and CSF regional volumes. The two patient groups did not differ in mean age at illness onset, duration of illness, severity of psychotic symptoms, or disorganization; DS had more severe avolition and worse social functioning than NDS. For validation purposes, brain structures were manually outlined on original MR images in 10 studies, thus obtaining reference measures. Manual and automated measures were repeated 1 month apart to measure reproducibilities of both methods. The automated method required less than 1 min/operator per study vs more than 30 min for manual assessment. Mean absolute difference per structure between the two techniques was 4.8 ml. Overall reproducibility did not significantly differ between the two methods. In subjects with schizophrenia, a significant decrease in GM and increase in CSF were found. GM loss was confined to frontal and temporal lobes. Lateral ventricles were significantly larger bilaterally in NDS compared to NV and only on the right in NDS compared to DS. The finding of greater structural brain abnormalities in NDS adds to the evidence that deficit schizophrenia does not represent just the more severe end of the schizophrenia continuum.

Adolescent↗
PubMedDate not supplied

Computed tomographic anatomy of the canine inner and middle ear.

A series of high-resolution computed x-ray tomography (CT) images of the normal canine middle and inner ear are presented to serve as a reference for optimal interpretation of clinical CT images of animals with diseases affecting this region.

Animals↗