PATRICK JACK SPENCER
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Possui graduação em Ciências Biológicas pela Universidade Presbiteriana Mackenzie (1991), mestrado em Tecnologia Nuclear pela Universidade de São Paulo (1995) e doutorado em Tecnologia Nuclear pela Universidade de São Paulo (2000) tendo sido bolsista sandwich no US Army Medical Research Institute for Infeccious Diseases (98-99). É responsável pelo Biotério de criação e manutenção de animais de laboratório do IPEN. Tem experiência na área de Bioquímica, com ênfase em Proteínas, atuando principalmente nos seguintes temas: veneno, proteínas, bothrops, irradiação e miotoxina.(Texto extraído do Currículo Lattes em 22 dez. 2021)
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Artigo IPEN-doc 27822 Characterization and evaluation of the enzymatic activity of tetanus toxin submitted to cobalt-60 gamma radiation2021 - SARTORI, GISELLE P.; COSTA, ANDREA da; MACARINI, FERNANDO L. dos S.; MARIANO, DOUGLAS O.C.; PIMENTA, DANIEL C.; SPENCER, PATRICK J.; NALI, LUIZ H. da S.; GALISTEO JUNIOR, ANDRES J.Background Tetanus toxin blocks the release of the inhibitory neurotransmitters in the central nervous system and causes tetanus and its main form of prevention is through vaccination. The vaccine is produced by inactivation of tetanus toxin with formaldehyde, which may cause side effects. An alternative way is the use of ionizing radiation for inactivation of the toxin and also to improve the potential immunogenic response and to reduce the post-vaccination side effects. Therefore, the aim of this study was to characterize the tetanus toxin structure after different doses of ionizing radiation of 60Co. Methods Irradiated and native tetanus toxin was characterized by SDS PAGE in reducing and non-reducing conditions and MALD-TOF. Enzymatic activity was measured by FRET substrate. Also, antigenic properties were assessed by ELISA and Western Blot data. Results Characterization analysis revealed gradual modification on the tetanus toxin structure according to doses increase. Also, fragmentation and possible aggregations of the protein fragments were observed in higher doses. In the analysis of peptide preservation by enzymatic digestion and mass spectrometry, there was a slight modification in the identification up to the dose of 4 kGy. At subsequent doses, peptide identification was minimal. The analysis of the enzymatic activity by fluorescence showed 35 % attenuation in the activity even at higher doses. In the antigenic evaluation, anti-tetanus toxin antibodies were detected against the irradiated toxins at the different doses, with a gradual decrease as the dose increased, but remaining at satisfactory levels. Conclusion Ionizing radiation promoted structural changes in the tetanus toxin such as fragmentation and/or aggregation and attenuation of enzymatic activity as the dose increased, but antigenic recognition of the toxin remained at good levels indicating its possible use as an immunogen. However, studies of enzymatic activity of tetanus toxin irradiated with doses above 8 kGy should be further analyzed.Resumo IPEN-doc 27445 Hypanus americanus mucus2020 - COELHO, GUILHERME R.; PREZOTTO NETO, JOSE P.; BARBOSA, FERNANDA C.; SANTOS, RAFAEL S.; BRIGATTE, PATRICIA; SPENCER, PATRICK J.; SAMPAIO, SANDRA C.; D'AMELIO, FERNANDA; PIMENTA, DANIEL C.; SCIANI, JULIANA M.Fish skin plays important biological roles, such as the control of the osmotic pressure gradient, protection against mechanical forces and microorganism infections. The mucus, on the other hand, is a rich and complex fluid, important for the fish acting as innate immunity system, swimming and nutrition. The elasmobranch epidermis is characterized mainly by mucus secretory cells, and marine stingrays have already been described to present secretory glands spread throughout the body. Little is known about the biochemical composition of the stingray mucus, but recent studies denoted the importance of mucus in the envenomation process. Stingrays venom are largely studied due the human medical importance of envenoming caused by sting puncture, that evolve with local inflammation and necrosis, and these toxic events can be correlated to the chemical composition of the sting skin, according to the literature. Aiming to analyse the mucus composition, a new non-invasive mucus collection method was developed that focused on peptides and proteins, and biological assays were performed to analyze preliminary toxic and immune activities of the Hypanus americanus mucus. Pathophysiological characterization showed the presence of peptidases on mucus, as well that the induction of edema and leukocyte recruitment in mice. The fractionated mucus improved phagocytosis on macrophages and showed antimicrobial activity against T. rubrum, C. neoformans and C. albicans in vitro. The proteomic analyses showed the presence of immune-related proteins like actin, histones, hemoglobin, and ribosomal proteins. This protein pattern is similar to those reported for other fish mucus and stingray venom. This is the first report depicting the Hypanus stingray mucus composition, highlighting its biochemical composition and importance for the stingray immune system and the possible role on the envenomation process.