NANCI DO NASCIMENTO
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Resumo IPEN-doc 13668 Immunological properties of sup(60)Co gamma rays irradiated bothropstoxin-I2008 - BAPTISTA, J.A.; VIEIRA, D.P.; GALISTEO JUNIOR, A.J.; CAPRONI, P.; CASARE, M.; ANDRADE JUNIOR, H.F.; SPENCER, P.J.; NASCIMENTO, N.Artigo IPEN-doc 10724 Influence of reactive radicals OH and Esup(-)sub(AQ) in irradiation of protein in aqueous solutions2005 - BACETI, A.A.; CESARE, M.; SPENCER, P.J.; NASCIMENTO, N.Gamma irradiation of aqueous proteins solutions promotes structural modifications. This is mainly caused by OH • and eaq activity, reactive species produced by water radiolys. The objective of this study was to investigate the role of OH • and eaq in conformation changes observed in proteins irradiated in aqueous solutions. Substances that react specifically with OH • or eaq producing stable products were used in order to study each reactive species’ function: nitrate for eaq and t-butilic alcohol for OH • . Crotamine was used as test peptide. It is composed of 42 aminoacids, which are strongly reticulated by three disulfide bonds. This confers it a very compact conformation leading to high temperatures resistance. Crotamine also has a biological effect: mice hind limb distention. Samples of crotamine in aqueous solution were irradiated in order to analyze the activity of OH • and eaq. Some contemned t-butilic alcohol and others, sodium nitrate; the results were compared to control samples with no neutralizing substances. To verify possible protein conformation change due to sodium nitrate or t-butilic alcohol addition, samples with different concentrations of these substances were prepared, kept without irradiation and their results were compared to only protein solution. Samples were also submitted to a biological test Samples were submitted to SDS-PAGE, which did not show any alteration in those samples with t-butilic alcohol or sodium nitrate. In addition, the samples had their absorbance spectrum of 200 nm to 360 nm scanned which showed less conformation change in irradiated with t-butilic then only protein one. Irradiated samples had less biological effect than non-irradiated ones.Artigo IPEN-doc 10775 Evaluation of toxic activity loss and maintenance of immunological properties of crotoxin after gamma irradiation2005 - SILVA, M.C.S.; SPENCER, P.J.; ALVES, J.B.; NASCIMENTO, N.Artigo IPEN-doc 10737 Immune response against bothropstoxin-I irradiated with sup(60) gamma rays2005 - BAPTISTA, J.A.; SPENCER, P.J.; HIGA, O.Z.; ANDRADE JUNIOR, H.F.; CESARE, M.S.; CAMPOS, L.A.; NASCIMENTO, N.Artigo IPEN-doc 15166 Irradiated T Cruzi and resistant consomic animals can be useful in chagas disease studies2009 - DIAS, VIVIANE L.; PASSOS, LUIZ A.C.; SPENCER, PATRICK J.; SALGADO, ANDREIA R.; NASCIMENTO, NANCIArtigo IPEN-doc 15165 Ovarian transfer following irradiation as an alternative to restore reproductive functions2009 - SALGADO, ANDREIA R.; PASSOS, LUIZ A.C.; SPENCER, PATRICK J.; GIMENES, ANA P.; DIAS, VIVIANE L.; NASCIMENTO, NANCIAssisted reproduction technologies are essential for restoring reproductive functions, especially in ovary cancer cases, which besides impairing fertility; present the highest lethality amongst gynecological diseases. Classical treatment involves surgery, radiotherapy and chemotherapy, and in young women, the recommended treatment is the removal of the affected ovary, leading to physical, psychological and emotional problems. An alternative would be the ovarian transfer after the treatment. However, there are no data in the literature about experiments specifically designed to investigate the interference of this procedure on reproductive functions. In the present work, we used the C57BL/6Unib and B6CF1 hybrid mice strains to evaluate the viability of ovarian transfer before and after irradiation, as well as possible differences in radiosensitivity between the strains. To do so, female mice from both strains were irradiated with 4 Gy and submitted to either partial or total ovarian transfer form healthy donors. After the surgery, the animals were mated and the results obtained so far for mating 7 days after the procedure indicate that irradiation promoted a significant decrease in fertility (p=0.0127). Also, our data show that the recovery of fertility is proportional to the amount of grafted ovarian tissue. Furthermore, there seems to be differences in radiosensitivity, from genetic origin, between the two mice strain, since, after irradiation, the hybrid mice had bigger litters than the donor strain.Artigo IPEN-doc 15156 Physico-chemical characterization of gamma rays irradiated crotamine2009 - OLIVEIRA, KARINA C. de; SPENCER, PATRICK J.; NASCIMENTO, NANCIIonizing radiation can change the molecular structure and affect the biological properties of biomolecules. It has been employed to attenuate animal toxins. Crotamine, a toxin from Crotalus durissus terrificus (Cdt), is a highly basic polypeptide (pI - 10.3), with myotoxic activity and molecular weight of 4882 Da. It is composed of 42 amino acids residues and reticulated by three disulfide bonds. This study aimed the characterization of irradiated crotamine using Circular Dichroism (CD), Fluorescence Spectroscopy and Differential Scanning Calorimetry (DSC) techniques. We used size exclusion and ion-exchange chromatography to purify it from Cdt crude venom. The pure crotamine was irradiated with 2.0 kGy from a 60Co source. Native and irradiated crotamine were analyzed in a fluorescence spectrophotometer (Hitachi F-4500), under excitation wavelength at 275 nm and the emission was scanned from 300 to 500 nm. The analysis of fluorescence quenching showed that the irradiated form displayed a lower quantum yield when compared to the native form. CD spectra, obtained from a Jasco, J-180 spectropolarimeter, of native and irradiated crotamine solutions, showed a discrete change between the samples, from apparently ordered conformation to a random coil. Finally, the thermodynamics analysis, realized in a calorimeter METTLER TOLEDO, DSC 822e, showed that irradiation promoted changes in the calorimetric profile. Our results indicate that irradiation leads to progressive changes in the structure of the toxin, which could explain the decrease in myotoxic activity.Artigo IPEN-doc 11952 Structure alteration and immunological properties of sup(60)Co gamma rays irradiated bothropstoxin-I2007 - BAPTISTA, JANAINA A.; VIEIRA, DANIEL P.; GALISTEO JUNIOR, ANDRES J.; YONAMINE, CAMILA M.; CAPRONI, PRISCILA; CASARE, MURILO; ANDRADE JUNIOR, HEITOR F. de; SPENCER, PATRICK J.; NASCIMENTO, NANCI doResumo IPEN-doc 13117 The lesson from snake venom: ion transport and glycolysis are couple through the pumping rate of the Na/KAT pase2007 - LIMA, V.M.F. de; HANKE, W.; CAMILLO, M.A.; SPENCER, P.; NASCIMENTO, N.Artigo IPEN-doc 11620 Immune response against irradiated with sup(60)Co gamma-rays2006 - BAPTISTA, J.A.; SPENCER, P.J.; OLIVEIRA, J.E.; CESARE, M.S.; NASCIMENTO, N.