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Aydin M, Lucia S, Casella A, Di Bello B, Di Russo F. Bayesian interpretation of the prefrontal P2 ERP component based on stimulus/response mapping uncertainty. Int J Psychophysiol 2024; 199:112337. [PMID: 38537889 DOI: 10.1016/j.ijpsycho.2024.112337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 02/22/2024] [Accepted: 03/19/2024] [Indexed: 04/21/2024]
Abstract
The brain can be seen as a predictive system continuously computing prior information to guess posterior probabilities minimizing sources of uncertainty. To test this Bayesian view of the brain, event-related potentials (ERP) methods have been used focusing on the well-known P3 component, traditionally associated with decision-making processes and sources of uncertainty regarding target probability. Another ERP component linked with decision-making is the prefrontal P2 (pP2) component, which has never been considered within the Bayesian framework. To test which source of uncertainty could be associated with the pP2, uncertainty induced by target probability and stimulus-response (S/R) mapping were modulated in three visuomotor tasks. Results showed that the pP2 had the largest amplitude in the task with the largest uncertainty regarding the S/R mapping and degraded as the S/R mapping became more predictable. The P3 was maximal in the tasks with larger uncertainty regarding the target probability. While we confirmed the P3 association with target probability, we extended our knowledge on the pP2 associating it with S/R mapping uncertainty. This component, which has been previously localized within the anterior insular cortex, may minimize S/R mapping uncertainty allowing response-related evidence accumulation and comparing current events with internal representations to extract action-related probabilities.
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Affiliation(s)
- Merve Aydin
- Dept. of Movement, Human and Health Sciences, University of Rome "Foro Italico", 00135 Rome, Italy.
| | - Stefania Lucia
- Dept. of Movement, Human and Health Sciences, University of Rome "Foro Italico", 00135 Rome, Italy
| | - Andrea Casella
- Dept. of Movement, Human and Health Sciences, University of Rome "Foro Italico", 00135 Rome, Italy
| | - BiancaMaria Di Bello
- Dept. of Movement, Human and Health Sciences, University of Rome "Foro Italico", 00135 Rome, Italy
| | - Francesco Di Russo
- Dept. of Movement, Human and Health Sciences, University of Rome "Foro Italico", 00135 Rome, Italy; Santa Lucia Foundation IRCCS, 00179 Rome, Italy
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Ishida T, Wakai E, Hagiwara M, Makimura S, Tada M, Asner D, Casella A, Devaraj A, Edwards D, Prabhakaran R, Senor D, Hartz M, Bhadra S, Fiorentini A, Cadabeschi M, Martin J, Konaka A, Marino A, Atherthon A, Densham C, Fitton M, Ammigan K, Hurh P. Study of the radiation damage effect on Titanium metastable beta alloy by high intensity proton beam. Nuclear Materials and Energy 2018. [DOI: 10.1016/j.nme.2018.04.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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3
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Pejrona M, Berjano P, Cecchinato R, Casella A, Lamartina C. Posterior surgery or lateral lumbar interbody fusion for degenerative deformity? Comparative data. J Neurosurg Sci 2014; 58:77-80. [PMID: 25371953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
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4
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Randelli P, Spennacchio P, Ragone V, Arrigoni P, Casella A, Cabitza P. Complications associated with arthroscopic rotator cuff repair: a literature review. Musculoskelet Surg 2011; 96:9-16. [PMID: 22205384 DOI: 10.1007/s12306-011-0175-y] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Accepted: 12/07/2011] [Indexed: 01/08/2023]
Abstract
The aim of this literature review was to report complications associated with arthroscopic rotator cuff repair (RCR). A computerized search of articles published between 200 and 2009 was performed using MEDLINE and PubMed. We included clinical studies (Level 1-4): (a) investigating patients with rotator cuff tears, managed by a completely arthroscopic RCR technique; (b) reported data about complications. Data about arthroscopic-assisted techniques were excluded. Articles that meet criteria inclusion were analytically examined. Complications were classified into general complications and specific complications related to arthroscopic RCR. We found 414 complications in 2,890 patients; most of them were specific complications related to arthroscopic RCR. Re-rupture was the most frequently encountered complication: re-tear rate ranged between 11.4 and 94%. Stiffness and hardware-related complications were observed in 74 and 12 patients, respectively. Eleven less common complications were also reported: 5 neurovascular, 3 septic, 2 thromboembolic events, and 1 anesthesiological complication. This review stated that arthroscopic RCR is a low-risk surgical procedure. Anatomical failure of the repair is the most common complication encountered in the literature.
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Affiliation(s)
- P Randelli
- Dipartimento Di Scienze Medico-Chirurgiche, Università Degli Studi Di Milano, IRCCS Policlinico San Donato, Milan, Italy
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5
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Milano W, Petrella C, Casella A, Capasso A, Carrino S, Milano L. Use of sibutramine, an inhibitor of the reuptake of serotonin and noradrenaline, in the treatment of binge eating disorder: a placebo-controlled study. Adv Ther 2005; 22:25-31. [PMID: 15943219 DOI: 10.1007/bf02850181] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Binge-eating disorder, which is characterized by repeated episodes of uncontrolled eating, is common in obese patients and is often accompanied by comorbid psychiatric disorders, especially depression. In previous studies, selective serotonin reuptake inhibitors have demonstrated efficacy in reducing the frequency of binge eating and addressing comorbid psychiatric disorders, but they have not shown the ability to promote weight loss. Sibutramine, a new serotonin and norepinephrine reuptake inhibitor, has been shown in short- and long-term studies to be effective in promoting and maintaining weight loss in obese patients who have binge-eating disorder. In this randomized, double-blind, placebo-controlled study, the efficacy, safety, and tolerability of sibutramine were evaluated in the treatment of binge-eating disorder in obese patients. Twenty patients were randomly assigned in equal numbers to receive either sibutramine 10 mg/day or placebo for 12 weeks. Assessments were made at baseline and every 2 weeks throughout the study. Binge frequency, defined as the number of days during the previous week that included binge-eating episodes, was the primary outcome measure. By the end of the study, the binge frequency among patients given sibutramine was significantly lower than that among those given placebo. The main adverse events in the sibutramine group were dry mouth and constipation. The findings suggest sibutramine is an effective medication in the treatment of binge-eating disorders and is well tolerated. In addition, it addresses the 3 main goals in the treatment of binge-eating disorder: reducing the frequency of binge eating, promoting and maintaining weight loss, and treating the comorbid psychiatric conditions.
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Affiliation(s)
- W Milano
- Mental Health Operations Unit, District 44 ASL, Napoli 1, Italy
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Antinori S, Galimberti L, Magni C, Casella A, Vago L, Mainini F, Piazza M, Nebuloni M, Fasan M, Bonaccorso C, Vigevani GM, Cargnel A, Moroni M, Ridolfo A. Cryptococcus neoformans infection in a cohort of Italian AIDS patients: natural history, early prognostic parameters, and autopsy findings. Eur J Clin Microbiol Infect Dis 2001; 20:711-7. [PMID: 11757972 DOI: 10.1007/s100960100616] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
This observational cohort study of 4,160 AIDS patients hospitalised in a single institution in northern Italy between January 1985 and December 1999 was carried out in order to assess the natural history of cryptococcosis, the epidemiological trend of this opportunistic infection, the risk factors predictive of death at 10 weeks, the response to therapy, and autopsy findings. Cryptococcosis was diagnosed in 177 (4.2%) patients and was the AIDS-defining disease in 2.8% of cases. Its prevalence decreased significantly over time (from 6.4% in the period 1985-1989 to 5.7% in 1990-1993, 3.1% in 1994-1996, and 1.9% in 1997-1999, P <0.0001). Although neurologic disease was the most frequent clinical picture, a significant proportion of the patients (24.2%) presented with extraneural cryptococcosis. In a Cox multivariate analysis, high titres of cerebrospinal fluid antigen (>5000) and drug addiction were predictive of death at 10 weeks. A complete clinical and mycological response was achieved in 60.8% of the treated patients, with the highest response rate being observed in those treated with amphotericin plus flucytosine (66.6%). Cryptococcosis relapsed in 12.8% of patients on secondary prophylaxis. Autopsy findings demonstrated that cryptococcosis is a disseminated disease, but long-term antifungal treatment may be able to eradicate it in a subgroup of patients.
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Affiliation(s)
- S Antinori
- Department of Infectious and Tropical Diseases, L. Sacco Hospital, University of Milan, Italy.
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Casella A, Pisano R, Navarro Cuellar C, Llopis P, Mallagray R, Lavorgna G. Papillary carcinoma of the base of the tongue. Case clinic. Minerva Stomatol 1999; 48:535-8. [PMID: 10768012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Ectopic lingual thyroid tissue is an uncommon developmental anomaly. Tumours of identical pathological characteristics as those arising in the eutropic thyroid tissue, may be present in ectopic locations. There are very few cases of malignant tumours reported in the literature. Here we report a review of this pathology and we describe a case of a papillary carcinoma of the base of the tongue, located in ectopic lingual thyroid tissue, in a 66 year-old white man, complaining of dysphagia and oral bleeding. Surgical treatment was carried out, consisting of radical resection of the right hemineck, tumour resection, right hemiglossectomy and total thyroidectomy. Postoperative treatment with 131I and substitutive thyroid hormonal therapy was prescribed.
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Affiliation(s)
- A Casella
- Department of Systematic Pathology, Faculty of Medicine and Surgery, University of the Studies, Naples
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Mallagray R, Betoret J, Navarro Cuellar C, Lavorgna G, Pisano R, Casella A. Diffuse acute cellulitis with severe neurological sequelae. A clinical case. Minerva Stomatol 1999; 48:161-4. [PMID: 10431537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
The incidence of head and neck odontogenic infections considerably diminished in the last decades due to appropriate antibiotic therapy. Herein we describe a case of acute diffuse facial cellulitis following tooth extraction in a patient with no apparent risk factor. During the acute process, injury was caused to the hypoglossal, vagal, glossopharyngeal and recurrent nerves of both sides. For this reason the patient currently has a nasogastric line for enteral feedings and a tracheotomy tube, which significantly affects his quality of life.
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Affiliation(s)
- R Mallagray
- Department of Systematic Pathology, Faculty of Medicine and Surgery, University of the Studies, Federico II, Naples
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Casella A, Lavorgna G, Pisano R, Navarro Cuellar C, Cuesta Gil M, Navarro Vila C. [Oncologic post-resection reconstruction of mandibular defects]. Minerva Stomatol 1999; 48:139-50. [PMID: 10431535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
BACKGROUND AND AIM If not reconstructed, mandibular defects resulting from oncological surgery can leave major functional and cosmetic sequelae which may impede these patients from returning to professional and family life. Reconstruction may be immediate or deferred, but the authors clearly recommend immediate reconstruction. METHODS An analysis is made of the different techniques used for the reconstruction of mandibular defects, specifying those which are currently used and the situations in which they are applied. The advantages and disadvantages of microsurgical flaps and pedicled flaps are emphasised. The immediate use of endosseous implants is also discussed. RESULTS The results of the various types of reconstruction are compared from a cosmetic and functional point of view. The latter includes a study of the quality of speech, deglutition, mastication and labial competence. Mastication is studied in two types of patients: those with osteointegrated implants with neomandibular reconstruction and those in whom osteointegrated implants were not used. All these patients survived 5 years after surgery. CONCLUSIONS The authors recommend the immediate reconstruction of mandibular defects. Microsurgical flaps and pedicled flaps can be used for this purpose. Bone flaps may be used for endosseous titanium implants, whereas osseous flaps which do not provide a sufficient guarantee of rehabilitation should not be used. Implants should be inserted during oncological surgery, since postoperative radiotherapy may alter osteointegration of titanium implants are then used. The overall survival of these patients depends on the margins of local resection which are much wider using these techniques.
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Affiliation(s)
- A Casella
- Dipartimento di Patologia Sistematica, Facoltà di Medicina e Chirurgia, Università degli Studi Federico II, Napoli
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Orlando G, Fasolo MM, Signori R, Schiavini M, Casella A, Cargnel A. Impact of highly active antiretroviral therapy on clinical evolution of genital warts in HIV-infected patients. AIDS 1999; 13:291-3. [PMID: 10202844 DOI: 10.1097/00002030-199902040-00026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Ballmer P, Kleger GR, McNurlan M, Casella A, Turgay M, Garlick P. P.9 Acute metabolic acidosis does not down-regulatealbumin synthesis in humans. Clin Nutr 1997. [DOI: 10.1016/s0261-5614(97)80133-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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12
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Russo A, Dell'Aquila A, Casella A, Lavorgna G. [A statistical contribution to fractures of the maxillofacial area]. Minerva Stomatol 1997; 46:139-45. [PMID: 9221315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Twenty years experience (from 1975 to 1994), on 483 patients with injury of the maxillo-facial area observed at the Department of Maxillo-Facial Surgery of the University of Naples "Federico II" is reported. The analysis of the data, according to the literature, shows that the sex most involved is male (76%) with a prevalence of the second decade of life (38%); street injury is the most frequent cause of maxillo-facial fracture (48.5%), while in 1.6% the cause is not reported. Mandibular fractures (57%), particularly those of the left condyle, are more frequent. The type of treatment is discussed in relation to the site of fracture, in particular the therapy of the condylar ones. In fact, in the treatment of those fractures the authors use sequential functional plates, the first of whose presents a monolateral byte, homolateral to the injury, while the second a contralateral guide in closure. The use of such plates, even if it doesn't often obtain a perfect anatomical realignment of the fracture, allows an optimal functional rehabilitation due to the potential of remodelling of the condyle, avoiding complications related to surgical intervention.
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Affiliation(s)
- A Russo
- Cattedra di Chirurgia Maxillo-Facciale, Facoltà di Medicina e Chirurgia, Università degli Studi di Napoli Federico II, Napoli
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Ferrari RP, Battiston B, Brunelli G, Casella A, Caimi L. The role of allopurinol in preventing oxygen free radical injury to skeletal muscle and endothelial cells after ischemia-reperfusion. J Reconstr Microsurg 1996; 12:447-50. [PMID: 8905544 DOI: 10.1055/s-2007-1006617] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
One of the most important mechanisms in the production of ischemic damage after replantation surgery is the rise of oxygen free radicals during revascularization of ischemic tissues. Free radicals produce damage in the cell membranes (lipoperoxydation). This occurs not only in muscle tissue, but also in endothelial cells, with a consequent increase of local edema and the risk of compartment syndrome. This study attempted to interrupt the ischemic-reperfusion injury process in ischemic rat hindlimbs. Complete ischemia was induced for different numbers of hours (3, 6, 9, 12 hr) in four groups of rats (24 animals in each group). Allopurinol, an oxygen free radical scavenger, was tested in solution, 12.5 mg/kg b.w., in half the studied animals (n = 12). Collected data showed an increase (mean value: 0.60 nM/mg 3 hri 0.90 nM/mg at 6 hr; 0.80 nM/mg at 9 hr; 0.89 nM/mg at 12 hr; mean value in nonischemic muscle = 0.526 nM/mg) in lipoperoxides (NS between treated/untreated groups, p > 0.05) and high tissue pressure values in the posterior compartment of the ischemic rat hindlimbs. Allopurinol reduced the pressure values (p < 0.05 in Groups 1-3; p < 0.1 in Group 4), but was not effective in reducing lipoperoxides in skeletal muscle.
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Affiliation(s)
- R P Ferrari
- Department of Orthopedics, University of Brescia, Italy
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Lavorgna G, Cortese A, Casella A, Giuffrè GL. [The correlation between sonoarthrographic and arthroscopic data. Its verification in a clinical case]. Minerva Stomatol 1994; 43:531-4. [PMID: 7739486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Surgical arthroscopy is an important option in the treatment of TMJ pain and disfunction. Also sonography of the TMJ is a technique that with recent improvements graphically displays and analyzes joint sounds. A comparison was performed between presurgical data obtained by sonography, clinical findings obtained by surgical arthroscopy, and post surgical control performed by sonography. Precise correlation between these data was found in the case reported.
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Affiliation(s)
- G Lavorgna
- Cattedra di Chirurgia Maxillo-Facciale, Facoltà di Medicina e Chirurgia, Università degli Studi di Napoli Federico II, Napoli
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Berta L, Fortunati N, Gennari P, Appendino M, Casella A, Frairia R. Influence of cigarette smoking on pituitary and sex hormone balance in healthy premenopausal women. Fertil Steril 1991; 56:788-9. [PMID: 1915961 DOI: 10.1016/s0015-0282(16)54620-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Plasma gonadotropin FSH and LH, PRL, sex steroids (17-beta E2, E1, and P), SBP binding capacity, and urine estrogens (E1, E2, and E3) were measured in 485 premenopausal healthy women, subdivided according to smoking habits. The aim of the study was to verify if cigarette smoking influences sex hormone balance. Baseline PRL levels were significantly lower (P less than 0.002) in smoker (n = 174) than in nonsmoker (n = 311) women. No difference was found in the other parameters of the two groups, particularly in plasma and urine estrogenic pattern. Our data suggest that smoking directly affects PRL levels by involving the hypothalamic mechanism that regulates PRL secretion.
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Affiliation(s)
- L Berta
- Dipartimento di Fisiopatologia Clinica, Cattedra di Medicina Interna, Università di Torino, Italy
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Marchesini S, Preti A, Aleo MF, Casella A, Dagan A, Gatt S. Synthesis, spectral properties and enzymatic hydrolysis of fluorescent derivatives of cerebroside sulfate containing long-wavelength-emission probes. Chem Phys Lipids 1990; 53:165-75. [PMID: 1970953 DOI: 10.1016/0009-3084(90)90042-p] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Fluorescent derivatives of cerebroside sulfate (sulfogalactosyl ceramide, sulfatide) containing long-wavelength-emission fluorophores were synthesized. For this purpose a procedure was developed for preparing a cerebroside 3-sulfate derivative with an amino group on the terminal carbon atom of its fatty acyl residue. The latter compound has been used to prepare cerebroside 3-sulfate, coupled to lissamine-rhodamine, fluoresceine, eosine and NBD. The spectroscopic properties of these compounds, in different solvent systems and when incorporated into micelles of a non-ionic detergent or liposomes of a phospholipid, are reported. Incubation of these respective sulfatides with a human leukocyte preparation, resulted in the formation of the corresponding fluorescent cerebrosides.
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Affiliation(s)
- S Marchesini
- Department of Biomedical Sciences and Biotechnology, University of Brescia, Italy
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Caimi L, Marchesini S, Aleo MF, Bresciani R, Monti E, Casella A, Giudici ML, Preti A. Rapid preparation of a distinct lysosomal population from myelinating mouse brain using Percoll gradients. J Neurochem 1989; 52:1722-8. [PMID: 2542449 DOI: 10.1111/j.1471-4159.1989.tb07250.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
To study the vesicular lysosome-associated transport and the metabolism of some brain macromolecules (in particular, sialoglycoconjugates), we developed a rapid procedure to obtain a distinct lysosomal population starting from myelinating mouse brain. This procedure is based on an initial differential centrifugation step producing a 1,000-17,500-g fraction (P2), followed by isopycnic centrifugation of fraction P2 on a self-generated colloidal silica gel (Percoll) gradient. The heaviest subfraction thus obtained is very rich in acid hydrolase activities like beta-galactosidase, arylsulfatase A, and acid phosphatase. The enrichment of these enzymes is approximately 100-fold as compared with the starting homogenate, whereas the markers of other subcellular organelles, such as mitochondria, plasma membranes, or the Golgi apparatus, are virtually absent. The lysosomal preparation contains approximately 12-14% of the total acid hydrolase activities, with a protein yield of approximately 0.12%. Electron microscopy shows that the lysosomal fraction is composed of an approximately 90% pure population of lysosomes. Therefore, the procedure described here is suitable for obtaining a highly purified lysosome preparation from myelinating mouse brain.
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Affiliation(s)
- L Caimi
- Department of Biomedical Sciences and Biotechnologies, Medical School, University of Brescia, Italy
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Abstract
A new method of purification of rat liver L-threonine deaminase has been developed, and the results obtained are compared with values obtained by other authors. Some properties of this enzyme (pH optimum, temperature optimum, thermal stability, specificity, etc.) have been examined and we found that the enzyme is inhibited by carbonate ions, that L-cysteine (a competitive inhibitor) is also an inactivator of the enzyme and that it is bound to the enzyme in a ratio of 0.25 mole of cysteine per mole of enzyme, supporting the hypothesis that the enzyme consists of 4 subunits.
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Abstract
The degree, the mechanism, and the specificity of the inhibition of purified rat-liver L-serine dehydratase (EC 4.2.1.13) by L-cysteine and aminothiols have been investigated. All the aminothiols tested react with free pyridoxal-5'-phosphate (PLP); only L-cysteine reacts with PLP bound to the enzyme giving an absorption spectrum similar to that of the thiazolidinic ring formed in the chemical reaction. The reaction between L-cysteine and PLP bound to the enzyme has a particular behaviour, different from all the other aminothiols. A stereospecific interaction between L-cysteine and PLP bound to the enzyme, forming one of the two possible diastereoisomers, is postulated.
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Aleo MF, Casella A, Marinello E. [The influence of fasting, of a hyperprotein diet and of nicotinamide on hepatic L-threonine deaminase]. Boll Soc Ital Biol Sper 1981; 57:1746-51. [PMID: 6458319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The induction of L-threonine deaminase, following nicotinamide injection has been studied: the effect of fasting and of hyperproteic diet have been also taken in consideration. Maximal induction is observed after 5 days hyperproteic diet, and is additional only with nicotinamide treatment. Results are interpreted assuming a different hepatic content and behavior of multiple forms of the enzyme.
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Aleo MF, Casella A, Marinello E. [L-threonine deaminase in gluconeogenesis]. Boll Soc Ital Biol Sper 1981; 57:1739-45. [PMID: 6458318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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