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G Antonini,A Bellelli,A Concetti,G Falcioni,M Brunori The reduction of cyanomethemoglobin by dithionite leads to the appearance of an intermediate, the complex of cyanide with ferrous hemoglobin, whose dissociation is easily followed in a stopped flow apparatus. This reaction was studied in the hemoglobin from the parasitic nematode Parascaris equorum... ( view more ), whose extremely high oxygen affinity is due to a very low dissociation rate. The rate of cyanide dissociation from ferrous Parascaris hemoglobin is not so dramatically different from that of other hemoglobins and myoglobins. Other features of the reaction are: (i) the rate constant of cyanide release is pH independent, an observation which is agreement with the possible absence of the distal histidine, given the mechanism suggested in a previous study (Bellelli, A., Antonini, G., Brunori, M, Springer, B.A. and Sligar, S.G. (1990) J. Biol. Chem. 265, 18898-18901), and (ii) the time-course shows no kinetic cooperativity. The structural basis of the extremely high oxygen affinity of Parascaris hemoglobin cannot be explained on the basis of the results here reported. This study also confirms that, even though cyanide binding to ferrous hemoglobins is controlled by distal interactions, the functional behaviour of this ligand is characteristic and differs from the behaviour of oxygen. ( view less ) A Bellelli,M Mattioni,V Rusconi,M L Sezzi,L BellelliPapain-immunized mice possess serum antibodies which cross-react with cathepsin-B- and cathepsin-H-like endopeptidases isolated from B16 melanoma cells. The growth rate, invasion and metastasis of both the B16 melanoma and the Lewis lung carcinoma were inhibited in mice immunized with papain. These... ( view more ) animals presented an increased mean survival time as compared to the tumor-bearing nonimmunized controls. Quantitative microscopy suggested that vasodilation and edema, associated with tumor invasion, are, at least partially, sustained by proteolytic enzymes, being strongly reduced when tumor cells were inoculated in papain-immunized mice. ( view less ) A Bellelli,C Camboni,G de Luca,M Materazzi,M Mattioni,M L Sezzi,L BellelliFlunarizine, a calcium antagonist commonly employed in therapy for vascular diseases, enhances the in vitro and in vivo antitumor activity of vincristine on B16 melanoma cells. In the presence of flunarizine higher intracellular levels of vincristine were observed in vitro and for a longer time. B1... ( view more )6 melanoma bearing mice treated with both the drugs presented a median survival time that was significantly longer than that of the controls. The possible mechanism of the enhancement is herein discussed. ( view less ) A Bellelli,L Bellelli,M Di Palma,I Lorenzon,M Mattioni,A Nista,I Pavese,V Rusconi,M L SezziThe treatment of exponentially-growing B16 melanoma cells with teniposide causes a dose- and time-dependent decrease of cell survival. By means of the nucleoid technique, the formation of double strand breaks was demonstrated in the nuclei of the treated cells, indicating a possible involvement of ... ( view more )topoisomerase II. DNA double strand breaks were rapidly but ineffectively repaired. Morphometric and densitometric analyses showed that teniposide treatment causes a considerable increase of nuclear area, nuclear DNA and cell size, associated with a lowering of the mitotic index to less than one hundredth of that of the controls. The cytocidal effect of VM-26 can be potentiated by the addition of a non-lethal dose of lonidamine, whose synergism is particularly evident at low teniposide concentrations. ( view less ) Barbara Borroni,Valentina Garibotto,Chiara Agosti,Simona Maria Brambati,Giuseppe Bellelli,Roberto Gasparotti,Alessandro Padovani,Daniela Perani BACKGROUND: Data on white matter changes in corticobasal degeneration syndrome (CBDS) are not yet available, whereas cortical gray matter loss is a feature of this condition. The structural abnormalities related to a key feature of CBDS (limb apraxia) are unknown. OBJECTIVES: To measure selective s... ( view more )tructural changes in early CBDS using diffusion tensor imaging and voxel-based morphometry and to evaluate the structural correlates of limb apraxia. DESIGN: Patient and control group comparison. SETTING: Referral center for dementia and movement disorders. PARTICIPANTS: Twenty patients with CBDS and 21 matched control subjects. INTERVENTIONS: Clinical and standardized neuropsychological evaluations, including assessment of limb apraxia. MAIN OUTCOME MEASURES: Gray and white matter changes in early CBDS. RESULTS: Diffusion tensor imaging revealed decreases in fractional anisotropy in the long frontoparietal connecting tracts, the intraparietal associative fibers, and the corpus callosum. Fractional anisotropy was also reduced in the sensorimotor projections of the cortical hand areas. Voxel-based morphometry showed a prevalent gray matter reduction in the left hemisphere (in the inferior frontal and premotor cortices, parietal operculum, superotemporal gyrus, and hippocampus). The pulvinar, bilaterally, and the right cerebellar cortex also showed atrophy. Limb apraxia correlated with parietal atrophy and with fractional anisotropy reductions in the parietofrontal associative fibers (P < .01). The limb-kinetic component of apraxia correlated with reduction of hand sensorimotor connecting fibers. CONCLUSIONS: The present integrative approach to in vivo structural anatomy combines hodologic imaging, describing patterns of white matter connections between cortical areas, with neuropsychological data. This provides new evidence of gray matter and fiber tract abnormalities in early-phase disease and contributes to clarifying the neural basis of apraxia in CBDS. ( view less ) Francesca Pintus,Anna Mura,Andrea Bellelli,Alessandro Arcovito,Delia Spanò,Anna Pintus,Giovanni Floris,Rosaria Medda A class III peroxidase, isolated and characterized from the latex of the perennial Mediterranean shrub Euphorbia characias, contains one ferric iron-protoporphyrin IX pentacoordinated with a histidine 'proximal' ligand as heme prosthetic group. In addition, the purified peroxidase contained 1 mole ... ( view more )of endogenous Ca(2+) per mole of enzyme, and in the presence of excess Ca(2+), the catalytic efficiency was enhanced by three orders of magnitude. The incubation of the native enzyme with Ni(2+) causes reversible inhibition, whereas, in the presence of excess Ca(2+), Ni(2+) leads to an increase of the catalytic activity of Euphorbia peroxidase. UV/visible absorption spectra show that the heme iron remains in a quantum mechanically mixed-spin state as in the native enzyme after addition of Ni(2+), and only minor changes in the secondary or tertiary structure of the protein could be detected by fluorescence or CD measurements in the presence of Ni(2+). In the presence of H(2)O(2) and in the absence of a reducing agent, Ni(2+) decreases the catalase-like activity of Euphorbia peroxidase and accelerates another pathway in which the inactive stable species accumulates with a shoulder at 619 nm. Analysis of the kinetic measurements suggests that Ni(2+) affects the H(2)O(2)-binding site and inhibits the formation of compound I. In the presence of excess Ca(2+), Ni(2+) accelerates the reduction of compound I to the native enzyme. The reported results are compatible with the hypothesis that ELP has two Ni(2+)-binding sites with opposite functional effects. ( view less ) Giuseppe Bellelli,Francesca Magnifico,Marco Trabucchi OBJECTIVES: This study investigates the cognitive, functional, and clinical variables associated with the risk of institutionalization, rehospitalization, and death at 12 months among a population of elderly discharged from a Rehabilitation and Aged Care Unit (RACU) within a 1-year period (May 1, 2... ( view more )004 to April 30, 2005). The RACU is a relatively new setting of care providing intensive rehabilitation and clinical support to elderly with highly heterogeneous reasons for admission. METHODS: There were 1303 patients (> or =65 years old) contacted 12 months after discharge from the RACU. We obtained information about institutionalization, rehospitalization, and death. Predictors were all the demographic and clinical variables potentially related to these outcomes. The relationship among predictors and outcomes was tested with multiple stepwise logistic regression models. RESULTS: Among the 1072 patients alive at the 12-month follow-up, 90 (8.4%) were institutionalized (3.4% early at discharge and 4.9% within the next period). The logistic regression analysis showed that 2 ranges of age (78 to 83 years and 84 years or more), living alone, occurrence of delirium, cognitive impairment (Mini Mental State Examination lower or equal to 20/30), and poor functional status at discharge (Barthel Index scores ranging from 69 to 85 and Barthel Index scores lower than 68/100) were independently and significantly associated with the risk of institutionalization during the 12 months following discharge from the RACU. Three hundred and twenty-three (30.1%) patients had been rehospitalized once and 86 (8.0%) patients twice at the 12-month follow-up. In the multivariate analysis, comorbidity (Charlson Index scores ranging from 2 to 3 and Charlson Index scores higher than 4) and delirium were significantly and independently associated with this outcome. One hundred and thirty-six (11.3%) patients had died by the 12-month follow-up. The stepwise logistic regression analysis showed that age greater than 83 years, poor functional status (Barthel Index lower than 60/100 at discharge), high comorbidity (Charlson Index scores ranging from 3 to 4 and Charlson Index scores higher than 4, respectively), and albumin serum levels ranging from 3.2 to 2.9 mg/dL and lower than 2.9 mg/dL independently and significantly predicted the 12-month risk of death. Absence of depressive symptoms (Geriatric Depression Scale <2/15) had instead a protective effect. CONCLUSION: Variables related to the sociodemographic, cognitive, functional, and health status predicted, with different degree of association, the 12-month risk of institutionalization, rehospitalization, and death among a population of elderly patients discharged from a RACU. Accordingly, various clinical and organizational approaches may be planned for prevention. ( view less ) Giuseppe Bellelli,Giovanni B Frisoni,Renato Turco,Elena Lucchi,Francesca Magnifico,Marco Trabucchi BACKGROUND: Delirium superimposed on dementia (DSD) is highly prevalent and associated with high mortality among hospitalized elderly patients, yet little is known about the effect of DSD on midterm mortality. The purpose of this study was to assess 12-month survival in patients with DSD and matche... ( view more )d groups with dementia alone, delirium alone, or neither delirium nor dementia. METHODS: Among 1278 consecutively admitted elderly participants (aged > or =65 years) to our Rehabilitation Unit between January 2002 and May 2005, four matched samples of 47 participants each (DSD, dementia alone, delirium alone, or neither delirium nor dementia) were selected. Matching was based on age, gender, and reason for admission. Postdischarge 12-month survival was assessed in the four groups with Kaplan-Meyer analysis and compared with Cox proportional hazard regression models adjusted for confounders. RESULTS: Survival was significantly lower for DSD patients than for the other three groups. After adjustment for comorbidity and Barthel Index score before admission, patients with DSD had significantly higher mortality (hazard ratio, 2.3; 95% confidence interval, 1.1-5.5; p =.04) than did patients with neither delirium nor dementia. CONCLUSIONS: Demented patients who experienced delirium during hospitalization had a more than twofold increased risk of mortality in the 12 months following discharge than did patients with dementia alone, with delirium alone, or with neither dementia nor delirium. ( view less ) Diego Serraino,Pierluca Piselli,Ghil Busnach,Patrizia Burra,Franco Citterio,Eloisa Arbustini,Umberto Baccarani,Emanuela De Juli,Ubaldo Pozzetto,Stefania Bellelli,Jerry Polesel,Christian Pradier,Luigino Dal Maso,Claudio Angeletti,Maria Patrizia Carrieri,Giovanni Rezza,Silvia Franceschi,Immunosuppression and Cancer Study Group  This investigation highlighted the risk of cancer in 8074 HIV-infected people and in 2875 transplant recipients in Italy and France. Observed and expected numbers of cancer were compared through sex- and age-standardised incidence ratios (SIRs) and 95% confidence intervals (CIs). After 15 years of ... ( view more )follow-up, the cumulative probability of cancer was 14.7% in transplant recipients and 13.3% in HIV-positives. The SIRs for all cancers were 9.8 in HIV-positives and 2.2 in transplants. Kaposi's sarcoma (SIR=451 in HIV-positives, 125 in transplants) and non-Hodgkin lymphoma (SIR=62 and 11.1, respectively) were the most common cancers. A significantly increased SIR for liver cancer also emerged in both groups. The risk of lung cancer was significantly elevated in heart transplant recipients (SIR=2.8), and of borderline statistical significance in HIV-positive people (95% CI:0.9-2.8). Immune depression entails a two-fold increased overall risk of cancers, mainly related to cancers associated with a viral aetiology. ( view less ) Louise J Gourlay,Francesco Angelucci,Paola Baiocco,Giovanna Boumis,Maurizio Brunori,Andrea Bellelli,Adriana E Miele Treatment of schistosomiasis, a widespread human parasitic disease caused by the helminth parasites of the genus Schistosoma, relies mainly on one chemotherapeutic agent, praziquantel, although several other compounds exert anti-parasitic effects. One such compound is the immunosuppressant cyclospo... ( view more )rin A, which has been shown to significantly diminish worm burden in mice infected with Schistosoma mansoni. Given the well established interaction between cyclosporin A and the cyclophilin superfamily of peptidylprolyl cis-trans isomerases, we solved the structure of cyclophilin A from S. mansoni (SmCypA) by x-ray crystallography in the reduced and oxidized states at 1.5 and 1.8 A of resolution, respectively. Oxidized SmCypA contains a disulfide bridge between two C-terminal cysteines (Cys-122 and Cys-126). This is the first example of a cyclophilin containing this disulfide bridge. Parallel functional studies suggest a mechanism for regulation of SmCypA activity via oxidation of its thiol groups; in fact, whereas oxidized SmCypA is inactive, reduced SmCypA is an efficient isomerase active at nanomolar levels with a k(cat)/K(m) of 1.1 x 10(7) M(-1) s(-1), and it is inhibited by cyclosporin A (IC(50) of 14 +/- 4 nM). The lack of conservation of this cysteine couple within the CypA superfamily, their close proximity to the active site, and the importance of thiol groups for peptidyl-prolyl cis-trans isomerase activity render this structural feature a challenge for the development of alternative and more effective anti-schistosomiasis inhibitors and may in addition imply an alternative function of SmCypA in the schistosome. ( view less ) F Angelucci,A Basso,A Bellelli,M Brunori,L Pica Mattoccia,C Valle The mechanism of action of praziquantel (PZQ), the drug of choice against schistosomiasis, is still unclear. Since exposure of schistosomes to the drug is associated with calcium influx and muscular contraction, calcium channels have been suggested as the target, although direct combination of PZQ ... ( view more )with their subunits was never demonstrated. We report a hitherto unknown effect of PZQ, namely the inhibition of nucleoside uptake, as observed in living worms using radio-isotope labelled adenosine and uridine. This effect is clearly seen in schistosomes but is absent in mammalian cells in culture. Moreover it is a specific pharmacological effect seen exclusively with the active levo-R(-)stereo isomer of the drug, and is shared by at least one benzodiazepine having antischistosomal activity. This novel effect acquires significance given that schistosomes cannot synthesize purine nucleosides de novo. A possible relationship between this novel effect and the known action of PZQ on calcium channels is discussed, since adenosine is known to bind to specific receptors and to behave as an indirect antagonist of calcium release in mammalian cells. If calcium channels were correlated with adenosine receptors also in schistosomes, as they are in mammals, this would support the hypothesis that PZQ-induced calcium influx may be correlated to adenosine receptor blockade. ( view less ) Alessandro Padovani,Chiara Agosti,Enrico Premi,Giuseppe Bellelli,Barbara BorroniIn the present study we aimed at evaluating the prevalence and the associated clinical, neuropsychological and behavioral features of extrapyramidal symptoms in Frontotemporal Dementia (FTD) patients. Seventy-five patients fulfilling clinical criteria of FTD were consecutively enrolled. Each patien... ( view more )t underwent clinical and extrapyramidal sign examination, and neuropsychological and behavioral disturbance evaluation. Each patient was submitted to both brain MRI and SPECT, documenting frontotemporal atrophy/hypoperfusion pattern. Parkinsonian symptoms in FTD were associated with a specific endophenotype characterized by higher incidence of psychotic symptoms, memory deficits and psychomotor speed ability abnormalities. Careful description of the spectrum of presentation of FTD may be of help for further understanding the underpinnings of the disease. ( view less ) Francesca Malerba,Andrea Bellelli,Alessandra Giorgi,Francesco Bossa,Roberto Contestabile Previous studies suggest that the addition of pyridoxal 5'-phosphate to apo-serine hydroxymethyltransferase from Escherichia coli is the last event in the enzyme's folding process. We propose a mechanism for this reaction based on quenched-flow, stopped-flow and rapid-scanning stopped-flow experime... ( view more )nts. All experiments were performed with an excess of apo-enzyme over cofactor, since excess pyridoxal 5'-phosphate results in a second molecule of cofactor binding to Lys346, which is part of the tetrahydropteroylglutamate-binding site. The equilibrium between the aldehyde and hydrate forms of the cofactor affects the kinetics of addition to the active site. Direct evidence of the formation of an intermediate aldimine between the cofactor and the active-site lysine was obtained. The results have been interpreted according to a three-step mechanism in which: (i) both aldehyde and hydrate forms of the cofactor bind rapidly and non-covalently to the apo-enzyme; (ii) only the aldehyde form reacts with the active-site lysine to give an intermediate internal aldimine with unusual spectral properties; and (iii) a final conformational change gives the native holo-enzyme. ( view less ) Giuseppe Bellelli,Giovanni B Frisoni,Marco Pagani,Francesca Magnifico,Marco Trabucchi BACKGROUND AND AIMS: To evaluate whether and which clinical factors affect the regimen of physical therapy (PT) treatment in elderly patients after hip fracture (HF). METHODS: HF patients consecutively admitted to a rehabilitation unit (from January 2002 to May 2004) without adverse clinical events... ( view more ) on admission or during hospital stay were considered (n=80). All patients underwent multidimensional assessment including demographic, clinical, cognitive, affective and functional status. Outcome measure was the number of rehabilitative procedures (NRP), computed as the ratio between sum of rehabilitative procedures and length of hospital stay. RESULTS: Patients received 3.8+/-1.3 NRP on average, although with large variability. Age and impairment of cognitive and pre-fracture functional status were significantly higher in those receiving fewer NRP. In a multiple regression model, only the Mini Mental State Examination (MMSE) significantly predicted NRP: compared with patients with MMSE < or =17, those with MMSE = 18-23, 24-26 and > or =27 received 0.3 (95% CI - 0.5-1.1, p=0.46), 1.5 (95% CI 0.6-2.4, p=0.001), and 1.6 (95% CI 0.7-2.5, p=0.001) more NRP. CONCLUSIONS: Cognitive performance affects NRP in elderly HF patients. Specific rehabilitative approaches, according to baseline cognitive performance, should be considered. ( view less ) Enrico P Spugnini,Alfonso Baldi,Bruno Vincenzi,Franco Bongiorni,Corrado Bellelli,Gennaro Citro,Alessandro Porrello Feline soft tissue sarcomas are spontaneous, rapidly growing, and aggressive neoplasms that mimic their human counterpart. The purpose of this study was to evaluate the feasibility and efficacy of electrochemotherapy (ECT) in an adjuvant fashion for the treatment of feline sarcomas, and the possibi... ( view more )lity of repeated treatments in the case of recurrence. Cats with fibrosarcoma (FSA) were assigned to receive surgery or surgery plus ECT. Feline patients recruited in the ECT study were enrolled in a microscopic arm (39 patients) or a macroscopic arm (19 patients) on the basis of their tumor status (absence or presence of gross disease). Patients received local injection of bleomycin followed by bursts of eight biphasic pulses at a voltage of 1,300 V/cm for postoperative and of 800 V/cm for intraoperative treatments. The median time to recurrence was 4 months for cats treated with surgery alone, 19 months for the postoperative cohort, and 12 months for the intraoperative group. Moreover, ten patients with recurring neoplasms were retreated and experienced responses lasting 6 to 28+ months. Side effects were minimal. Of interest, the metastatic rate (1.7%) in our patients was negligible: only one cat had distant spread. The results suggest that ECT is a well tolerated and potentially useful addition to surgery in controlling high-grade sarcomas. On the basis of these results, additional evaluations are warranted in pets and in humans. ( view less ) Barbara Borroni,Simona Maria Brambati,Chiara Agosti,Stefano Gipponi,Giuseppe Bellelli,Roberto Gasparotti,Valentina Garibotto,Monica Di Luca,Paola Scifo,Daniela Perani,Alessandro Padovani BACKGROUND: Two major clinical variants of frontotemporal dementia (FTD) have been described: frontal variant (fvFTD) and temporal variant (tvFTD). OBJECTIVE: To analyze white matter (WM) and gray matter (GM) tissue organization in patients with fvFTD and tvFTD by means of diffusion tensor imaging ... ( view more )and voxel-based morphometry, and the correlations with neuropsychological and behavioral variables. DESIGN AND SETTING: Frontotemporal dementia clinic-based cohort and structural magnetic resonance imaging acquisition for voxel-based morphometry and diffusion tensor imaging measurements. Abnormalities were detected by a comparison with healthy control subjects. These variables were also correlated with clinical scores. Patients Thirty-six patients (28 with fvFTD and 8 with tvFTD) in early disease stage and 23 healthy controls who underwent standardized clinical and neuropsychological evaluation and magnetic resonance imaging. INTERVENTIONS: Diffusion tensor imaging and voxel-based morphometry. MAIN OUTCOME MEASURES: Neuroimaging analyses resulted in localized GM atrophy and reductions of white matter densities; the latter correlated with behavioral scores. RESULTS: Voxel-based morphometry analysis showed separate patterns of GM atrophy in the 2 groups. Diffusion tensor imaging showed different WM reduction patterns in patients with fvFTD and tvFTD. The fvFTD group showed a selective WM reduction in the superior longitudinal fasciculus, interconnecting the frontal and occipital and the temporal and parietal regions. Conversely, patients with tvFTD were characterized by WM reductions in the inferior longitudinal fasciculus, which affected the connections between anterior temporal and frontal regions. The WM reductions in fvFTD paralleled both behavioral disturbances measured by Frontal Behavioral Inventory and neuropsychological deficits affecting frontal functions. CONCLUSIONS: The fvFTD and tvFTD variants are associated not only with selective local GM reductions but also with significant WM damage in early disease phase. The different WM patterns contribute to the different clinical syndromes in FTD and could be responsible for the further progression of atrophy in the later disease stages. ( view less ) G Busnach,P Piselli,E Arbustini,U Baccarani,P Burra,M P Carrieri,F Citterio,E De Juli,S Bellelli,C Pradier,G Rezza,D Serraino,Immunosuppression and Cancer Study Group  The comparison of cancers occurring excessively among HIV-infected and transplanted individuals may help to elucidate the relationship between immune surveillance, viral infections, and cancer. A longitudinal study was conducted on 2002 HIV-infected Italian subjects, 6072 HIV-infected French indivi... ( view more )duals, and 2878 Italian recipients of solid organ transplants. Standardized incidence ratios (SIR) and 95% confidence intervals (CI) were computed to quantify the risk for cancer, compared with the French and Italian general populations. The SIRs for all cancers were 9.8 (95% CI: 9.0-10.6) for HIV-infected individuals versus 2.2 (95% CI: 1.9-2.5) for transplant recipients. In both groups, most of the excess risk was attributable to virus-related cancers, such as Kaposi's sarcoma (KS; SIR = 451 in HIV-positive individuals, 125 in transplant recipients), non-Hodgkin's lymphoma (NHL; SIR = 62.1 and 11.1, respectively), and liver cancer (SIR = 9.4 and 4.1, respectively). Significantly increased SIRs for anal cancer and Hodgkin's lymphoma were found only among HIV-positive individuals. Among women younger than 40 years of age, a more than 10-fold increase in cervical cancer risk was found in both groups. Among HIV-infected individuals treatment with highly active antiretroviral therapies drastically reduced SIRs for KS and NHL only. These results show that HIV-infected individuals and transplant recipients share a similar pattern of cancer risk, largely due to virus-related cancers. ( view less ) Stefano Gianni,Tine Walma,Alessandro Arcovito,Nicoletta Calosci,Andrea Bellelli,Ake Engström,Carlo Travaglini-Allocatelli,Maurizio Brunori,Per Jemth,Geerten W Vuister Understanding the basis of communication within protein domains is a major challenge in structural biology. We present structural and dynamical evidence for allosteric effects in a PDZ domain, PDZ2 from the tyrosine phosphatase PTP-BL, upon binding to a target peptide. The NMR structures of its fre... ( view more )e and peptide-bound states differ in the orientation of helix alpha2 with respect to the remainder of the molecule, concomitant with a readjustment of the hydrophobic core. Using an ultrafast mixing instrument, we detected a deviation from simple bimolecular kinetics for the association with peptide that is consistent with a rate-limiting conformational change in the protein (k(obs) approximately 7 x 10(3) s(-1)) and an induced-fit model. Furthermore, the binding kinetics of 15 mutants revealed that binding is regulated by long-range interactions, which can be correlated with the structural rearrangements resulting from peptide binding. The homologous protein PSD-95 PDZ3 did not display a similar ligand-induced conformational change. ( view less ) A Bellelli,P Mancini,M Polito,V David,P P Mariani PURPOSE: The aim of our study was to propose a new classification of acute posterior ligament (PCL) injuries based on magnetic resonance imaging (MRI). MATERIALS AND METHODS: Using MRI, we reviewed 220 patients presenting an acute posterior ligament injury. The MRI exam was performed on a 0.2-Tesla... ( view more ) (T) magnet and a 1.5-T magnet using T1-weighted spin echo (SE), T2-weighted SE and fat-suppression scans [short-tau inversion recovery (STIR)] in axial, sagittal and coronal planes. In no case was paramagnetic contrast agent injected. RESULTS: Twenty-five per cent of patients were identified as having type I lesions and another 30% as having type II lesions according to the Gross classification. Out of 77 patients, 35% of the whole sample, 37 had a tear of the posteromedial fascicle (type II lesion), and the remaining 40 had anterolateral fascicle tears (type III). In 10% of cases, the ligaments appeared completely interrupted, and these were classified as type IV lesions. CONCLUSIONS: T1-weighted SE sequences need to be integrated with T2-weighted and STIR sequences to detect the real extent of the remaining fascicle. The MRI exam could thus be able to provide a qualitative evaluation of PCL injuries and establish how the injury compromises joint stability. ( view less ) Paola Baiocco,Louise J Gourlay,Francesco Angelucci,Josette Fontaine,Maxime Hervé,Adriana E Miele,François Trottein,Maurizio Brunori,Andrea Bellelli During turnover, the catalytic tyrosine residue (Tyr10) of the sigma class Schistosoma haematobium wild-type glutathione-S-transferase is expected to switch alternately in and out of the reduced glutathione-binding site (G-site). The Tyrout10 conformer forms a pi-cation interaction with the guanidi... ( view more )nium group of Arg21. As in other similar glutathione-S-transferases, the catalytic Tyr has a low pKa of 7.2. In order to investigate the catalytic role of Tyr10, and the structural and functional roles of Arg21, we carried out structural studies on two Arg21 mutants (R21L and R21Q) and a Tyr10 mutant, Y10F. Our crystallographic data for the two Arg21 mutants indicate that only the Tyrout10 conformation is populated, thereby excluding a role of Arg21 in the stabilisation of the out conformation. However, Arg21 was confirmed to be catalytically important and essential for the low pKa of Tyr10. Upon comparison with structural data generated for reduced glutathione-bound and inhibitor-bound wild-type enzymes, it was observed that the orientations of Tyr10 and Arg35 are concerted and that, upon ligand binding, minor rearrangements occur within conserved residues in the active site loop. These rearrangements are coupled to quaternary rigid-body movements at the dimer interface and alterations in the localisation and structural order of the C-terminal domain. ( view less ) G Caracciolo,A Martelli,G Boumis,A Bellelli,R Caminiti,A Congiu-Castellano,G AmiconiThe radius of gyration (R(g)) of bovine trypsinogen and beta-trypsin was measured by an energy-dispersive X-ray technique as a function of Ca(2+) or SO(4)(2-) concentration; these results have been supplemented with measurements of association equilibrium constants of Ca(2+) to its binding site(s) ... ( view more )on both serine proteases and some of their adducts (with an effector and/or an inhibitor). As a whole, all information reported in the present work demonstrates that: (i) the strains exerted by different ions on these proteases produce diverse structural modifications; and (ii) at least in the case of Ca(2+), the changes in R(g) can be ascribed to the direct interaction of the binding site(s) on the protein matrix with the cation. ( view less ) Anna Mura,Francesca Pintus,Paola Lai,Alessandra Padiglia,Andrea Bellelli,Giovanni Floris,Rosaria Medda The reaction of Euphorbia characias latex peroxidase (ELP) with hydrogen peroxide as the sole substrate was studied by conventional and stopped-flow spectrophotometry. The reaction mechanism occurs via three distinct pathways. In the first (pathway I), ELP shows catalase-like activity: H2O2 oxidize... ( view more )s the native enzyme to compound I and subsequently acts as a reducing substrate, again converting compound I to the resting ferric enzyme. In the presence of an excess of hydrogen peroxide, compound I is still formed and further reacts in two other pathways. In pathway II, compound I initiates a series of cyclic reactions leading to the formation of compound II and compound III, and then returns to the native resting state. In pathway III, the enzyme is inactivated and compound I is converted into a bleached inactive species; this reaction proceeds faster in samples illuminated with bright white light, demonstrating that at least one of the intermediates is photosensitive. Calcium ions decrease the rate of pathway I and accelerate the rate of pathways II and III. Moreover, in the presence of calcium the inactive stable verdohemochrome P670 species accumulates. Thus, Ca2+ ions seem to be the key for all catalytic pathways of Euphorbia peroxidase. ( view less ) A Padovani,B Borroni,S M Brambati,C Agosti,M Broli,R Alonso,P Scifo,G Bellelli,A Alberici,R Gasparotti,D Perani BACKGROUND: A comprehensive characterisation of grey and white matter changes in progressive supranuclear palsy (PSP), the second most common extrapyramidal syndrome after Parkinson disease, is still not available. OBJECTIVE: To evaluate grey and white matter changes in mild PSP patients by voxel b... ( view more )ased morphometry (VBM) and diffusion tensor imaging (DTI), respectively. METHODS: 14 mild PSP patients and 14 healthy controls entered the study and underwent a clinical and neuropsychological evaluation according with a standardised assessment. Each subject had a structural magnetic resonance imaging (MRI) study. Processing analysis of MRI data was carried out according to optimised VBM and fractional anisotropy was determined. RESULTS: Compared with the controls, in PSP patients VBM analysis showed a significant clusters of reduced grey matter in premotor cortex, frontal operculum, anterior insula, hippocampus, and parahippocampal gyrus, bilaterally. With regard to subcortical brain regions, the pulvinar, dorsomedial and anterior nuclei of the thalamus, and superior and inferior culliculum were affected bilaterally. A bilateral decrease in fractional anisotropy in superior longitudinal fasciculus, anterior part of corpus callosum, arcuate fascicolus, posterior thalamic radiations, and internal capsule, probably involving the cortico-bulbar tracts, was present in PSP patients. CONCLUSIONS: These data provide evidence for both grey and white matter degeneration in PSP from the early disease stage. These structural changes suggest that atrophy of cortical and subcortical structures and neurodegeneration of specific fibre tracts contribute to neurological deficits in PSP. ( view less ) Barbara Borroni,Daniela Perani,Silvana Archetti,Chiara Agosti,Barbara Paghera,Giuseppe Bellelli,Monica Di Luca,Alessandro Padovani BACKGROUND: It has been recently demonstrated that in Frontotemporal Lobar Degeneration (FTLD) memory deficits at presentation are commoner than previously thought. Apolipoprotein E (ApoE) genotype, the major genetic risk factor in sporadic late-onset Alzheimer Disease (AD), modulates cerebral perf... ( view more )usion in late middle-age cognitively normal subjects. ApoE epsilon4 homozygous have reduced glucose metabolism in the same regions involved in AD.The aim of this study was to determine whether ApoE genotype might play a key-role in influencing the cerebral functional pattern as well as the degree of memory deficits in FTLD patients. METHODS: Fifty-two unrelated FTLD patients entered the study and underwent a somatic and neurological evaluation, laboratory examinations, a brain structural imaging study, and a brain functional Single Photon Emission Tomography study. ApoE genotype was determined. RESULTS: ApoE genotype influenced both clinical and functional features in FTLD. ApoE epsilon4-carriers were more impaired in long-term memory function (ApoE epsilon4 vs. ApoE non epsilon4, 6.3 +/- 3.9 vs. 10.1 +/- 4.2, p = 0.004) and more hypoperfused in uncus and parahippocampal regions (x,y,z = 38,-6,-20, T = 2.82, cluster size = 100 voxels; -32,-12,-28, T= 2.77, cluster size = 40 voxels). CONCLUSION: The present findings support the view that ApoE genotype might be considered a disease-modifying factor in FTLD, thus contributing to define a specific clinical presentation, and might be of relevance for pharmacological approaches. ( view less ) Laura Cortesi,Vincenzo E Chiuri,Silvia Ruscelli,Valeria Bellelli,Rossella Negri,Ivan Rashid,Claudia Cirilli,Antonella Fracca,Ennio Gallo,Massimo Federico BACKGROUND: The reduced mortality rate from breast carcinoma among women offered screening mammography is demonstrated after 15-20 years of follow-up. However, the assessment of 5-year overall and event-free survival could represent an earlier measure of the efficacy of mammography screening progra... ( view more )m (MSP). METHODS: All cases of breast cancer diagnosed in the Province of Modena between years 1996 and 2000 in women aged 50 to 69 years, were identified through the Modena Cancer Registry (MCR). Stage of disease and treatment information were obtained from clinical records. All the events occurring up to June 30, 2003 were retrieved by experienced monitors. Five-year overall and event-free survival were the principal end-points of the study. RESULTS: During a 5-year period, 587 primary breast cancers were detected by the MSP and 471 primary breast cancers were diagnosed out of the MSP. The screen-detected breast cancers were smaller, more likely node negative, with low histological grade, low proliferative activity and positive receptors status. Furthermore, the breast cancer diagnosed through the MSP more frequently received a conservative surgery. The 5-year survival rate was 94% in the screen-detected group, versus 84% in the other group (p = 0.0001). The rate of 5-year event-free survival was 89% and 75% for the MSP participants and not participants, respectively (p = 0.0001). CONCLUSIONS: Our data confirm a favourable outcome of screen-detected breast cancers in terms of five-year overall and event-free survival, which reflect the good quality assurance parameters of the MSP. Finally, a cancer registry should be implemented in every area covered by screening programs. ( view less )
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