21 results on '"Siddi, F"'
Search Results
2. Digital Phenotypic Assessment in Neuro-Oncology (DANO): tracking changes in sociability in patients undergoing treatment for brain malignancies
- Author
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Siddi, F., Emedom-Nnamdi, P., Catalino, M., Boaro, A., Dawood, H.Y., Onnela, J.-P., and Smith, T.R.
- Published
- 2021
- Full Text
- View/download PDF
3. Mobile-health and neurocognitive domains evaluation through smartphones: a meta-analysis
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Siddi, F., Amedume, A., Shah, A., Abunimer, A.M., Boaro, A., Regestein, Q.R., Smith, T.R., and Mekary, R.A.
- Published
- 2021
- Full Text
- View/download PDF
4. 'L'informazione che vorrei. La Rete, le sfide attuali, le priorità future'
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Ruben Razzante, Cardani, M, Catania, E, Costa, M, D'Asaro Biondo, C, D'Innella Capano, P, Fontana, L, Pitruzzella, G, Razzante, R, Sassoli de Bianchi, L, Siddi, F, Soro, A, Verna, C, Razzante, Ruben, Ruben Razzante, Cardani, M, Catania, E, Costa, M, D'Asaro Biondo, C, D'Innella Capano, P, Fontana, L, Pitruzzella, G, Razzante, R, Sassoli de Bianchi, L, Siddi, F, Soro, A, Verna, C, and Razzante, Ruben
- Abstract
L'Italia e l'Europa stanno vivendo cambiamenti epocali per il futuro dell'informazione digitale e della produzione e diffusione dei contenuti in Rete. L'informazione che vorrei intender essere una sorta di manifesto programmatico per la prossima legislatura, che spieghi a un pubblico generalista, dal punto di vista degli addetti ai lavori, quali saranno gli impegni che Parlamento e governo dovranno prendere in questi ambiti
- Published
- 2018
5. [Characterization of plasma glycosaminoglycans in hemodialysis patients]
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ALESSANDRO SENES, Siddi F, Demuro P, Formato M, and Gm, Cherchi
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Uronic Acids ,Renal Dialysis ,Chromatography, Gel ,Humans ,Electrophoresis, Cellulose Acetate ,Chromatography, DEAE-Cellulose ,Glycosaminoglycans - Abstract
Glycosaminoglycans are heteropolysaccharides composed of disaccharide repeating subunits, each one containing a uronic acid component (glucuronic or iduronic acid) and a hexosamine (N-acetyl-glucosamine or N-acetyl-galactosamine, which may be differently sulphated). The presence of GAGs in human plasma has been demonstrated in several studies; they are bound to plasma proteins through non-covalent linkages. However, very little is known about either their origin or their physiological role. Due to their anionic charge, they may influence some metabolic processes, such as blood coagulation, and they could also have a role in urolithiasis and atherogenesis. Moreover, they may be important in modulating the metabolism of some lipoproteins by affecting the rate of their catabolism. Modifications of GAG pattern have been described in a few pathological conditions such as mucopolysaccharidosis, connective tissue diseases and kidney diseases. A high frequency of accelerated atherosclerosis has been observed in haemodialysis patients (HD), probably associated with the altered lipoprotein profile, which is often described in these subjects. Since GAGs may play a role in lipoprotein metabolism, we isolated and characterized plasma GAGs from a group of HD patients and a group of normal matched subjects. Quantitative analysis of plasma GAGs showed a significant increase of these polysaccharides in the HD group. Circulating levels of GAGs were 8.21 +/- 1.89 micrograms/ml in control subjects, and 15.08 +/- 3.13 micrograms/ml in the HD group (p0.0001). The isolation of plasma GAGs by ion-exchange chromatography produced two uronic acid containing families: a low-charge (peak I) and a high-charge (peak II) species. Both of these contained GAGs associated with plasma proteins.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1992
6. [Study of the interaction between plasma proteoglycans and LDL by means of fluorescence spectroscopy]
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Siddi F, ALESSANDRO SENES, Coinu R, Formato M, and Gm, Cherchi
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Lipoproteins, LDL ,Chromatography, Gel ,Humans ,Fluorescence Polarization ,Proteoglycans ,Chromatography, DEAE-Cellulose ,Glycosaminoglycans ,Protein Binding - Abstract
The relevance of the interaction between LDL and PGs in the development of atherosclerotic processes is well known. However, the exact nature of the interaction and the consequent structural and/or conformational modifications of the lipoprotein remain to be clarified. It has been demonstrated that after this interaction the LDL particle is not recognized by specific cellular receptors and enters the scavenger pathway operating in different cell types. These effects have been shown by using aortic PGs, but PGs are also present in the plasma compartment and may interact constantly with LDL, taking part in the regulation of lipid metabolism. In order to assess the capability of plasma PGs to induce LDL modifications, we investigated their interactions by studying the changes in the organizational parameters of LDL by fluorescence spectroscopy. Plasma PGs were isolated by DEAE Sephacel ion exchange chromatography and Sephacryl S300 gel filtration in two different families: a low-charge PG and a high-charge PG. Human LDL was prepared from plasma of normolipemic donors by ultracentrifugal flotation between 1.025-1.045 g/ml. Steady-state anisotropy measures were obtained by analyzing the rotational diffusion rate of DPH after incubation of LDL with plasma PGs in a physiological ratio. In our experimental conditions, LDL incubation with plasma low-charge PG did not modify DPH fluorescence anisotropy, whereas LDL treatment with highly charged PGs induced a marked decrease of this parameter, suggesting a significant effect on LDL microviscosity. The data show that both the charge and the GAG composition of PGs appear to be critical factors in LDL-PG interaction.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1992
7. [Separation and quantification of glycosaminoglycans using HPLC]
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ALESSANDRO SENES, Siddi F, Gm, Cherchi, and Formato M
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Chromatography, Gel ,Humans ,Reproducibility of Results ,Aorta, Thoracic ,Reference Standards ,Chromatography, Ion Exchange ,Chromatography, High Pressure Liquid ,Glycosaminoglycans - Abstract
Biochemical studies of proteoglycans (PGs) involve the characterization of their polysaccharide chains. In fact, PGs display a considerable heterogeneity with respect to type and size of the saccharide chains, to the ratio of iduronic to glucuronic acid and to the degree of sulphation. Several HPLC methods have been described for separation and identification of glycosaminoglycans (GAGs), which usually employ molecular sieving and disaccharide analysis, after specific enzyme digestion of GAGs. In order to separate intact GAGs, we utilized both high performance gel permeation and ion exchange chromatography, using a Spherogel TSK 4000SW and a Spherogel TSK DEAE 25W respectively. HPLC gel permeation chromatography makes it possible to separate only HA from other GAGs. This procedure can be useful to purify biological preparations from HA, so allowing GAG study in non-aggregating conditions. HPLC ion exchange chromatography was performed on GAG standard mixtures and the suitability of the method was tested on GAGs extracted from intima and media preparations of human thoracic aorta. In our chromatographic conditions HA eluted at 0.5 M NaCl, HS at 0.54 M NaCl, DS at 0.61 M NaCl and C6S at 0.65 M. C4S coeluted with DS and C6S. To determine DS concentration the samples were reanalyzed after chondroitinase AC treatment; the differences in uronic acid content between the original samples and the digests represented the total amount of C4S and C6S. Our data indicate a good reproducibility of the method that allows a rapid and accurate determination of intact GAGs in biological samples.
8. The Cerebral Aqueduct Compliance: A Simple Morphometric Model.
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Longatti P, Gioffrè G, Fiorindi A, Siddi F, Boaro A, Basaldella L, Sala F, and Feletti A
- Abstract
Background and Objectives: This work aimed to identify different configurations of the adytum of the cerebral aqueduct suggesting its safe neuroendoscopic navigation. This concept is intimately connected to the physiological aqueductal dilatability or compliance, which is relatively ignored in the literature. A better knowledge of the extent of physiological aqueductal dilatability might better define the ideal diameter and safer features of dedicated flexible endoscopes., Methods: The study includes 45 patients operated on using a flexible scope with a 3.9-mm diameter, where the structural elements of the adytum of the cerebral aqueduct are clearly visible. Patients were grouped according to the pathology (colloid cyst/normal anatomy, intraventricular hemorrhage, tetraventricular obstructive hydrocephalus, normal pressure hydrocephalus, and distal membranous aqueductal stenosis). A simple geometrical scheme was applied to the endoscopic anatomy of the aqueductal adytum in relation to the posterior commissure to measure its pathologic deformations. Eventual damages to the aqueduct walls caused by the endoscope were also reported., Results: Proceeding from normal anatomy to hydrocephalic condition, the ratio between the commissure and the aqueductal access area progressively decreases, while the vertex angle increases. Interestingly, the entity of the ependymal damages due to the passage of the endoscope correlates with such measures., Conclusion: The cerebral aqueduct, excluding atrophic processes, is provided with a certain degree of dilatability, which we estimate to be around a diameter of 4 mm. This represents the maximum size for a flexible neuroendoscope for a safe aqueductal neuronavigation. The schematic model of the aqueductal adytum as a triangle defines 3 different aqueductal patterns and can be helpful when an intraoperative decision on whether to navigate the aqueduct must be taken., (Copyright © Congress of Neurological Surgeons 2024. All rights reserved.)
- Published
- 2024
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9. Motor Pathways Reorganization following Surgical Decompression for Degenerative Cervical Myelopathy: A Combined Navigated Transcranial Magnetic Stimulation and Clinical Outcome Study.
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Boaro A, Nunes S, Bagattini C, Di Caro V, Siddi F, Moscolo F, Soda C, and Sala F
- Abstract
(1) Background: Degenerative cervical myelopathy is one of the main causes of disability in the elderly. The treatment of choice in patients with clear symptomatology and radiological correlation is surgical decompression. The application of navigated transcranial magnetic stimulation (nTMS) techniques has the potential to provide additional insights into the cortical and corticospinal behavior of the myelopathic cord and to better characterize the possible extent of clinical recovery. The objective of our study was to use nTMS to evaluate the effect of surgical decompression on neurophysiological properties at the cortical and corticospinal level and to better characterize the extent of possible clinical recovery. (2) Methods: We conducted a longitudinal study in which we assessed and compared nTMS neurophysiological indexes and clinical parameters (modified Japanese Orthopedic Association score and nine-hole pegboard test) before surgery, at 6 months, and at 12 months' follow-up in a population of 15 patients. (3) Results: We found a significant reduction in resting motor threshold (RMT; average 7%), cortical silent period (CSP; average 15%), and motor area (average 25%) at both 6 months and 12 months. A statistically significant linear correlation emerged between recruitment curve (RC) values obtained at follow-up appointments and at baseline (r = 0.95 at 6 months, r = 0.98 at 12 months). A concomitant improvement in the mJOA score and in the nine-hole pegboard task was observed after surgery. (4) Conclusions: Our results suggest that surgical decompression of the myelopathic spinal cord improves the neurophysiological balance at the cortical and corticospinal level, resulting in clinically significant recovery. Such findings contribute to the existing evidence characterizing the brain and the spinal cord as a dynamic system capable of functional and reversible plasticity and provide useful clinical insights to be used for patient counseling.
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- 2024
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10. Daily Pain Prediction Using Smartphone Speech Recordings of Patients With Spine Disease.
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Duey AH, Rana A, Siddi F, Hussein H, Onnela JP, and Smith TR
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- Humans, Speech, Spine, Pain diagnosis, Pain etiology, Smartphone, Spinal Diseases complications, Spinal Diseases diagnosis, Spinal Diseases surgery
- Abstract
Background: Pain evaluation remains largely subjective in neurosurgical practice, but machine learning provides the potential for objective pain assessment tools., Objective: To predict daily pain levels using speech recordings from personal smartphones of a cohort of patients with diagnosed neurological spine disease., Methods: Patients with spine disease were enrolled through a general neurosurgical clinic with approval from the institutional ethics committee. At-home pain surveys and speech recordings were administered at regular intervals through the Beiwe smartphone application. Praat audio features were extracted from the speech recordings to be used as input to a K-nearest neighbors (KNN) machine learning model. The pain scores were transformed from a 0 to 10 scale to low and high pain for better discriminative capacity., Results: A total of 60 patients were enrolled, and 384 observations were used to train and test the prediction model. Using the KNN prediction model, an accuracy of 71% with a positive predictive value of 0.71 was achieved in classifying pain intensity into high and low. The model showed 0.71 precision for high pain and 0.70 precision for low pain. Recall of high pain was 0.74, and recall of low pain was 0.67. The overall F1 score was 0.73., Conclusion: Our study uses a KNN to model the relationship between speech features and pain levels collected from personal smartphones of patients with spine disease. The proposed model is a stepping stone for the development of objective pain assessment in neurosurgery clinical practice., (Copyright © Congress of Neurological Surgeons 2023. All rights reserved.)
- Published
- 2023
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11. Optical properties of nanostructured antiviral and anticancer drugs.
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Pisu AA, Siddi F, Cappellini G, and Cardia R
- Abstract
We present a computational study on the optical absorption properties of some systems of interest in the field of drug delivery. In particular we considered as drug molecules favipiravir (T705, an antiviral molecule) and 5-fluorouracil (5FU, an anticancer molecule) and, on the other hand, pure fullerenes (C
24 , B12 N12 , Ga12 N12 ) and doped fullerenes (C23 B, CB11 N12 ) are considered as nanocarriers. Some combined configurations between the drug molecules and the carrier nanostructures have been then studied. The optical absorption properties of the above mentioned drug molecules and their carrier nanostructures in the free and bound states are obtained by a TD-DFT method, in gas phase and in aqueous solution. We perform a detailed analysis of the modifications arising in the absorption spectra that take place in some linked configurations between the drug molecules and the carrier nanostructures. These changes could be of importance as an optical fingerprint of the realized drug/carrier link., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)- Published
- 2023
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12. Efficacy and safety of flexible versus rigid endoscopic third ventriculostomy in pediatric and adult populations: a systematic review and meta-analysis.
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Boaro A, Mahadik B, Petrillo A, Siddi F, Devi S, Chawla S, Abunimer AM, Feletti A, Fiorindi A, Longatti P, Sala F, Smith TR, and Mekary RA
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- Adult, Child, Child, Preschool, Humans, Infant, Retrospective Studies, Treatment Outcome, Ventriculostomy adverse effects, Hydrocephalus surgery, Neuroendoscopy, Pediatrics, Third Ventricle surgery
- Abstract
Endoscopic third ventriculostomy (ETV) is a well-established surgical procedure for hydrocephalus treatment, but there is sparse evidence on the optimal choice between flexible and rigid approaches. A meta-analysis was conducted to compare efficacy and safety profiles of both techniques in pediatrics and adults. A comprehensive search was conducted on PubMED, EMBASE, and Cochrane until 11/10/2019. Efficacy was evaluated comparing incidence of ETV failure, while safety was defined by the incidence of perioperative complications, intraoperative bleedings, and deaths. Random-effects models were used to pool the incidence. Out of 1365 studies, 46 case series were meta-analyzed, yielding 821 patients who underwent flexible ETV and 2918 who underwent rigid ETV, with an age range of [5 days-87 years]. Although flexible ETV had a higher incidence of failure in adults (flexible: 54%, 95%CI: 22-82% vs rigid: 20%, 95%CI: 22-82%) possibly due to confounding due to etiology in adults treated with flexible, a smaller difference was seen in pediatrics (flexible: 36%, pediatric: 32%). Safety profiles were acceptable for both techniques, with a certain degree of variability for complications (flexible 2%, rigid 18%) and death (flexible 1%, rigid 3%) in pediatrics as well as complications (rigid 9%, flexible 13%), death (flexible 4%, rigid 6%) and intra-operative bleeding events (rigid 6%, flexible 8%) in adults. No clear superiority in efficacy could be depicted between flexible and rigid ETV for hydrocephalus treatment. Safety profiles varied by age but were acceptable for both techniques. Well-designed comparative studies are needed to assess the optimal endoscopic treatment option for hydrocephalus., (© 2021. The Author(s).)
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- 2022
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13. The low utility of routine cranial imaging after pediatric shunt revision.
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Hulsbergen AFC, Siddi F, McAvoy M, Lynch BT, Karsten MB, Stopa BM, Ashby J, McNulty J, Broekman MLD, Gormley WB, Stone SSD, Warf BC, and Proctor MR
- Abstract
Objective: Postoperative routine imaging is common after pediatric ventricular shunt revision, but the benefit of scanning in the absence of symptoms is questionable. In this study, the authors aimed to assess how often routine scanning results in a change in clinical management after shunt revision., Methods: The records of a large, tertiary pediatric hospital were retrospectively reviewed for all consecutive cases of pediatric shunt revision between July 2013 and July 2018. Postoperative imaging was classified as routine (i.e., in the absence of symptoms, complications, or other direct indications) or nonroutine. Reinterventions within 30 days were assessed in these groups., Results: Of 387 included shunt revisions performed in 232 patients, postoperative imaging was performed in 297 (77%), which was routine in 244 (63%) and nonroutine in 53 (14%). Ninety revisions (23%) underwent any shunt-related procedure after postoperative imaging, including shunt reprogramming (n = 35, 9%), shunt tap (n = 10, 3%), and a return to the operating room (OR; n = 58, 15%). Of the 244 cases receiving routine imaging, 241 did not undergo a change in clinical management solely based on routine imaging findings. The remaining 3 cases returned to the OR, accounting for 0.8% (95% CI 0.0%-1.7%) of all cases or 1.2% (95% CI 0.0%-2.6%) of cases that received routine imaging. Furthermore, 27 of 244 patients in this group returned to the OR for other reasons, namely complications (n = 12) or recurrent symptoms (n = 15); all arose after initial routine imaging., Conclusions: The authors found a low yield to routine imaging after pediatric shunt revision, with only 0.8% of cases undergoing a change in management based on routine imaging findings without corresponding clinical findings. Moreover, routine imaging without abnormal findings was no guarantee of an uneventful postoperative course. Clinical monitoring can be considered as an alternative in asymptomatic, uncomplicated patients.
- Published
- 2021
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14. Mobile health and neurocognitive domains evaluation through smartphones: A meta-analysis.
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Siddi F, Amedume A, Boaro A, Shah A, Abunimer AM, Bain PA, Cellini J, Regestein QR, Smith TR, and Mekary RA
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- Neuropsychological Tests, Prospective Studies, Smartphone, Mobile Applications, Telemedicine
- Abstract
Background: Mobile health (mHealth) have significantly advanced evaluating neurocognitive functions; but, few reports have documented whether they validate neurocognitive impairments as well as paper-and-pencil neuropsychological tests., Objective: To meta-analyze the correlation between mobile applications for neuropsychological tests and validated paper-and-pencil neuropsychological tests for evaluating neurocognitive impairments., Method: We used PubMed, Embase, Cochrane, Web of Science, and IEEE Explorer through January 2020 to identify studies that compared mobile applications for neuropsychological tests vs. paper-and-pencil neurophysiological tests. We used random-effects models via the DerSimonian and Laird method to extract pooled Pearson's correlation coefficients and we stratified by study design., Result: Nine out of 4639 screened articles (one RCT and eight prospective longitudinal case series) were included. For the observational studies, there was a statistically significant strong and direct correlation between mobile applications for neuropsychological test scores and validated paper-and-pencil neuropsychological assessment scores (r = 0.70; 95% CI 0.59, 0.79; I
2 = 74.5%; p- heterogeneity <0.001). Stronger results were seen for the RCT (r = 0.92; 95% CI 0.77, 0.97)., Conclusion: This meta-analysis showed a statistically significant correlation between mobile applications and the validated paper-and-pencil neuropsychological assessments analyzed for the evaluation of neurocognitive impairments., Competing Interests: Declaration of Competing Interest The authors have no conflicts of interest to declare., (Copyright © 2021 Elsevier B.V. All rights reserved.)- Published
- 2021
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15. Smartphone GPS signatures of patients undergoing spine surgery correlate with mobility and current gold standard outcome measures.
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Boaro A, Leung J, Reeder HT, Siddi F, Mezzalira E, Liu G, Mekary RA, Lu Y, Groff MW, Onnela JP, and Smith TR
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- Geographic Information Systems, Humans, Mobility Limitation, Outcome Assessment, Health Care, Pain, Patient Reported Outcome Measures, Smartphone, Spinal Diseases surgery
- Abstract
Objective: Patient-reported outcome measures (PROMs) are currently the gold standard to evaluate patient physical performance and ability to recover after spine surgery. However, PROMs have significant limitations due to the qualitative and subjective nature of the information reported as well as the impossibility of using this method in a continuous manner. The smartphone global positioning system (GPS) can be used to provide continuous, quantitative, and objective information on patient mobility. The aim of this study was to use daily mobility features derived from the smartphone GPS to characterize the perioperative period of patients undergoing spine surgery and to compare these objective measurements to PROMs, the current gold standard., Methods: Eight daily mobility features were derived from smartphone GPS data in a population of 39 patients undergoing spine surgery for a period of 2 months starting 3weeks before surgery. In parallel, three different PROMs for pain (visual analog scale [VAS]), disability (Oswestry Disability Index [ODI]) and functional status (Patient-Reported Outcomes Measurement Information System [PROMIS]) were serially measured. Segmented linear regression analysis was used to assess trends before and after surgery. The Student paired t-test was used to compare pre- and postoperative PROM scores. Pearson's correlation was calculated between the daily average of each GPS-based mobility feature and the daily average of each PROM score during the recovery period., Results: Smartphone GPS features provided data documenting a reduction in mobility during the immediate postoperative period, followed by a progressive and steady increase with a return to baseline mobility values 1 month after surgery. PROMs measuring pain, physical performance, and disability were significantly different 1 month after surgery compared to the 2 immediate preoperative weeks. The GPS-based features presented moderate to strong linear correlation with pain VAS and PROMIS physical score during the recovery period (Pearson r > 0.7), whereas the ODI and PROMIS mental scores presented a weak correlation (Pearson r approximately 0.4)., Conclusions: Smartphone-derived GPS features were shown to accurately characterize perioperative mobility trends in patients undergoing surgery for spine-related diseases. Features related to time (rather than distance) were better at describing patient physical and performance status. Smartphone GPS has the potential to be used for the development of accurate, noninvasive and personalized tools for patient mobility monitoring after surgery.
- Published
- 2021
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16. Improved outcomes associated with maximal extent of resection for butterfly glioblastoma: insights from institutional and national data.
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Boaro A, Kavouridis VK, Siddi F, Mezzalira E, Harary M, Iorgulescu JB, Reardon DA, and Smith TR
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- Biopsy, DNA Methylation, DNA Modification Methylases genetics, DNA Repair Enzymes genetics, Female, Humans, Prognosis, Promoter Regions, Genetic, Brain Neoplasms genetics, Brain Neoplasms surgery, Glioblastoma genetics, Glioblastoma surgery
- Abstract
Background: Butterfly glioblastomas (bGBMs) are grade IV gliomas that infiltrate the corpus callosum and spread to bilateral cerebral hemispheres. Due to the rarity of cases, there is a dearth of information in existing literature. Herein, we evaluate clinical and genetic characteristics, associated predictors, and survival outcomes in an institutional series and compare them to a national cohort., Methods: We identified all adult patients with bGBM treated at Brigham & Women's Hospital (2008-2018). The National Cancer Database (NCDB) was also queried for bGBM patients. Survival was analyzed with Kaplan-Meier methods, and Cox models were built to assess for predictive factors., Results: Of 993 glioblastoma patients, 62 cases (6.2%) of bGBM were identified. Craniotomy for resection was attempted in 26 patients (41.9%), with a median volumetric extent of resection (vEOR) of 72.3% (95% confidence interval [95%CI] 58.3-82.1). The IDH1 R132H mutation was detected in two patients (3.2%), and MGMT promoter was methylated in 55.5% of the assessed cases. In multivariable regression, factors predictive of longer OS were increased vEOR, MGMT promoter methylation, and receipt of adjuvant therapy. Median OS for the resected cases was 11.5 months (95%CI 7.7-18.8) vs. 6.3 (95%CI 5.1-8.9) for the biopsied. Of 21,353 GBMs, 719 (3.37%) bGBM patients were identified in the NCDB. Resection was more likely to be pursued in recent years, and GTR was independently associated with prolonged OS (p < 0.01)., Conclusion: Surgical resection followed by adjuvant chemoradiation is associated with significant survival gains and should be pursued in carefully selected bGBM patients.
- Published
- 2021
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17. Over ten years overall survival in glioblastoma: A different disease?
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Marton E, Giordan E, Siddi F, Curzi C, Canova G, Scarpa B, Guerriero A, Rossi S, D' Avella D, Longatti P, and Feletti A
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- Adolescent, Adult, Aged, Aged, 80 and over, Brain Neoplasms surgery, Child, Child, Preschool, Cohort Studies, Female, Follow-Up Studies, Glioblastoma surgery, Humans, Magnetic Resonance Imaging trends, Male, Middle Aged, Retrospective Studies, Survival Rate trends, Time Factors, Young Adult, Brain Neoplasms diagnostic imaging, Brain Neoplasms mortality, Glioblastoma diagnostic imaging, Glioblastoma mortality
- Abstract
Purpose: The reasons why a specific subset of glioblastoma (GBM) patients survive longer than others is still unclear. This study analyzed a cohort of long-term and very-long-term GBM survivors to determine which genetic alterations or patient's characteristics influence survival time., Methods: We retrospectively reviewed a cohort of GBM patients treated at our institution over the last 20 years, stratifying patients in three groups: those with a survival time ≥ 36 months and < 120 months (LTS), ≥120 months (VLTS), and < 36 months, respectively. Clinical (age, sex, focality, resection degree, Karnofsky performance status), and immunohistochemical and molecular data (Ki-67 expression and multiple genes alterations) were collected. We then utilized principal component analysis, logistic regression, and Cox proportional hazard models to identify those variables associated with survival., Results: Younger age at presentation (HR = 0.36, 95% CI 0.21-0.67, p = .001), and MGMT promoter [(MGMTp), methylated, HR = 0.57, CI 0.34-0.96, p = .034) were associated with higher odds of VLTS survival. The multivariate analysis showed how the combination of younger age (< 50 years), Ki-67 < 10%, and the coexistence of TERTp not mutated, MGMTp methylated, and IDH1/2 mutated in the same patient are also associated with higher odds of survival (HR = 0.10, CI 0.01-0.74, p = .025)., Conclusions: We confirmed younger age at presentation and MGMTp methylation as the only independent factors associated with VLTS. The exceptional survival of our VLTS patients is probably associated with different, still understudied, gene mutations, or with the coexistence of multiple factors., (Copyright © 2019 Elsevier B.V. All rights reserved.)
- Published
- 2020
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18. Post-Treatment Edema after Meningioma Radiosurgery is a Predictable Complication.
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Conti A, Pontoriero A, Siddi F, Iatì G, Cardali S, Angileri FF, Granata F, Pergolizzi S, Germanò A, and Tomasello F
- Abstract
Symptomatic post-treatment edema (PTE) causing seizures, focal deficits, and intracranial hypertension is a rather common complication of meningioma radiosurgery. Factors associated to the occurrence of PTE still needs to be clarified. We retrospectively analyzed our patients' data to identify factors associated with the development of symptomatic PTE. Supposed risk factors were systematically analyzed. Between July 2007 and March 2014, 245 meningiomas in 229 patients were treated by a single fraction or multisession radiosurgery (2-5 fractions) or hypofractionated stereotactic radiotherapy (6-15 fractions) using the CyberKnife system (Accuray Inc., Sunnyvale, CA) at the University Hospital of Messina, Italy. Local tumor control was achieved in 200 of 212 patients with World Health Organization (WHO) Grade I meningiomas (94%) at a mean follow-up of 62 months. Symptomatic PTE on MRI was diagnosed in 19 patients (8.3%) causing seizure (n=17, 89%), aggravating headache (n=12, 63%), or focal deficits (n=13, 68%). Four variables were found to be associated with the likelihood of edema development, including tumor volume > 4.5 mL, non-basal tumor location, tight brain/tumor interface, and atypical histology. Nonetheless, when multivariate logistic regression analysis was performed, only tumor volume and brain-tumor interface turned out to be independent predictors of PTE development. Our results suggest that the factor associated with the risk of developing PTE is associated to characteristics of meningioma rather than to the treatment modality used. Accordingly, an appropriate patient selection is the way to achieve safe treatment and long-term disease control.
- Published
- 2016
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19. [Morphologic evaluation of adhesive/resin cement system and fiber post: a sem investigation].
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Lugliè P, Siddi F, Chessa G, and Lai V
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- Humans, Microscopy, Electron, Scanning, Mineral Fibers, Dental Implants, Resin Cements
- Abstract
Aim: The purpose of the present paper is to carry out an SEM investigation into the adhesive cementation of quartz fibre posts in canals treated with endodontic cements containing or not containing eugenol., Methods: Sixteen selected tooth roots were subdivided into 4 groups and prepared with the step-back technique. Group A, without canal filling and with a cemented post, was the control group; in groups B and C, the canals were closed with guttapercha, endomethasone C and eugenol, those of group D with guttapercha and AH Plus without eugenol. The canals were prepared so as to be able to take D.T. light-posts irrigated with water (group C with ethyl alcohol) mordanted with orthophosphoric acid after applying 2 layers of photopolymerised ONE-STEP; 2 layers of ONE-STEP were applied to the post. DUO-LINK cement was positioned in the canal after inserting the post, removing excess resin and photopolymerising. The samples were prepared for SEM observation., Results: Group A: the apical portion shows the post absorbed into the cement and resin tags; group B: porosity is noted between cement and post, the hybrid layer does not present tissue penetration of the dentin resin; group C: bullae can be seen between cement and post surface and between hybrid layer and cement; group D: there is relative continuity between post surface, cementing resin, hybrid layer and underlying dentin., Conclusion: The study has shown that eugenol interferes with the formation of the hybrid layer, the pictures relative to the resinous cement appeared different depending on whether the canal was treated with cement containing or not containing eugenol.
- Published
- 2003
20. [Separation and quantification of glycosaminoglycans using HPLC].
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Senes A, Siddi F, Cherchi GM, and Formato M
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- Aorta, Thoracic chemistry, Chromatography, Gel, Chromatography, Ion Exchange, Humans, Reference Standards, Reproducibility of Results, Chromatography, High Pressure Liquid, Glycosaminoglycans isolation & purification
- Abstract
Biochemical studies of proteoglycans (PGs) involve the characterization of their polysaccharide chains. In fact, PGs display a considerable heterogeneity with respect to type and size of the saccharide chains, to the ratio of iduronic to glucuronic acid and to the degree of sulphation. Several HPLC methods have been described for separation and identification of glycosaminoglycans (GAGs), which usually employ molecular sieving and disaccharide analysis, after specific enzyme digestion of GAGs. In order to separate intact GAGs, we utilized both high performance gel permeation and ion exchange chromatography, using a Spherogel TSK 4000SW and a Spherogel TSK DEAE 25W respectively. HPLC gel permeation chromatography makes it possible to separate only HA from other GAGs. This procedure can be useful to purify biological preparations from HA, so allowing GAG study in non-aggregating conditions. HPLC ion exchange chromatography was performed on GAG standard mixtures and the suitability of the method was tested on GAGs extracted from intima and media preparations of human thoracic aorta. In our chromatographic conditions HA eluted at 0.5 M NaCl, HS at 0.54 M NaCl, DS at 0.61 M NaCl and C6S at 0.65 M. C4S coeluted with DS and C6S. To determine DS concentration the samples were reanalyzed after chondroitinase AC treatment; the differences in uronic acid content between the original samples and the digests represented the total amount of C4S and C6S. Our data indicate a good reproducibility of the method that allows a rapid and accurate determination of intact GAGs in biological samples.
- Published
- 1993
21. [Characterization of plasma glycosaminoglycans in hemodialysis patients].
- Author
-
Senes A, Siddi F, Demuro P, Formato M, and Cherchi GM
- Subjects
- Chromatography, DEAE-Cellulose, Chromatography, Gel, Electrophoresis, Cellulose Acetate, Humans, Uronic Acids blood, Glycosaminoglycans blood, Renal Dialysis
- Abstract
Glycosaminoglycans are heteropolysaccharides composed of disaccharide repeating subunits, each one containing a uronic acid component (glucuronic or iduronic acid) and a hexosamine (N-acetyl-glucosamine or N-acetyl-galactosamine, which may be differently sulphated). The presence of GAGs in human plasma has been demonstrated in several studies; they are bound to plasma proteins through non-covalent linkages. However, very little is known about either their origin or their physiological role. Due to their anionic charge, they may influence some metabolic processes, such as blood coagulation, and they could also have a role in urolithiasis and atherogenesis. Moreover, they may be important in modulating the metabolism of some lipoproteins by affecting the rate of their catabolism. Modifications of GAG pattern have been described in a few pathological conditions such as mucopolysaccharidosis, connective tissue diseases and kidney diseases. A high frequency of accelerated atherosclerosis has been observed in haemodialysis patients (HD), probably associated with the altered lipoprotein profile, which is often described in these subjects. Since GAGs may play a role in lipoprotein metabolism, we isolated and characterized plasma GAGs from a group of HD patients and a group of normal matched subjects. Quantitative analysis of plasma GAGs showed a significant increase of these polysaccharides in the HD group. Circulating levels of GAGs were 8.21 +/- 1.89 micrograms/ml in control subjects, and 15.08 +/- 3.13 micrograms/ml in the HD group (p < 0.0001). The isolation of plasma GAGs by ion-exchange chromatography produced two uronic acid containing families: a low-charge (peak I) and a high-charge (peak II) species. Both of these contained GAGs associated with plasma proteins.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1992
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