Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references (leaves 128-145). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references (leaves 128-145). Also available on the Internet.

Orientador: Stephen Hyslo / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-10T15:32:56Z (GMT). No. of bitstreams: 1 RochaeSilva_ThomazAugustoAlvesda_D.pdf: 9683821 bytes, checksum: 9eaf69e00f5ad25d739e7f014effdaed (MD5) Previous issue date: 2008 / Resumo: A aranha Vitalius dubius pertence à família Theraphosidae, que compreende todas as caranguejeiras. Sua distribuição é restrita à região Sudeste do Brasil, principalmente em São Paulo e Minas Gerais. Trata-se de uma espécie urbana, pouco agressiva e que não apresenta registros de acidentes com relevância clínica. O presente trabalho teve como objetivo descrever o aparato venenífero e caracterizar bioquímica e farmacologicamente a peçonha desta aranha. A estrutura do aparato venenífero consiste em duas robustas quelíceras anteriores, com grandes ferrões para imobilização de presas e inoculação de peçonha. Cada quelícera é preenchida por musculatura estriada, responsável pela mobilidade dos ferrões, além de abrigar a glândula de peçonha que, por sua vez, encontra-se imersa nesta musculatura, sem estar ligada à mesma. A glândula é envolta por duas túnicas musculares helicoidais entrelaçadas, responsáveis pela contração da glândula para expulsão da peçonha através de um duto interno ao ferrão. Interna à musculatura, uma camada basal rica em elastina sustenta uma complexa rede epitelial produtora de peçonha. Este epitélio extratificado possui células anastomosadas, com núcleos periféricos e prolongamentos citoplasmáticos voltados para a luz da glândula, organizado principalmente por filamentos de actina. Estes prolongamentos formam reservatórios envolvidos na biossíntese de peçonha. A análise ultra-estrutural deste epitélio revelou a presença de organelas envolvidas na síntese protéica, como núcleo com abundante eucromatina, nucléolo, retículo endoplasmático rugoso, polissomos, além de abundantes: retículo liso, aparato de Golgi, mitocôndrias e vacúolos autofágicos. Durante a fase de produção de peçonha, as principais alterações ultra-estruturais observadas foram compactação e remodelamento do epitélio, abundância de organelas e deformidade de núcleos, bem como a presença de hemócitos nos últimos estágios. A extração de peçonha revelou que as fêmeas possuem rendimento maior, em quantidade absoluta [23,1 ± 2,3 (n=11) e 12,5 ± 0,7 (n=16) mg de peçonha/aranha/extração, para fêmeas e machos, respectivamente]. No entanto, quando a quantidade de peçonha é relacionada ao o peso do animal, os machos possuem maior índice. Além disso, as fêmeas adultas com maior peso apresentaram rendimento de peçonha menor que as mais jovens. A caracterização bioquímicofarmacológica da peçonha revelou através de eletroforese que a peçonha de V. dubius possui poucas proteínas de elevada massa molecular, mas é rica em peptídeos e pequenas moléculas. A peçonha contém bastante hialuronidase, mas é destituída de atividade proteolítica, assim como não foi observada ação hemolítica. No imunoensaio de ELISA, a peçonha apresentou reatividade cruzada com soro antiaracnídico do Instituto Butantan, preparado contra as peçonhas de Loxosceles gaucho, Phoneutria nigriventer e Tityus serrulatus. No entanto, o immunoblotting demonstrou que apenas componentes da peçonha maiores que 30 kDa foram responsáveis por esta reação. A peçonha de V. dubius (10 - 300 µg/mL) foi citotóxica para células leucêmicas em cultura e exerceu forte ação edematogênica (10 µg/sítio causou o extravasamento de 90 ± 20 µL de plasma, n = 4) em pele de ratos, mediada em parte por receptores serotoninérgicos e a formação do óxido nítrico. A peçonha não apresentou significativa toxicidade quando testada em coração semi-isolado de barata. Em músculo liso (íleo de cobaia) a peçonha não causou contratura, mas produziu uma pequena potencialização da ação da bradicinina, e o bloqueio parcial de contrações eletroestimuladas em músculo anococígeo de ratos mediado por uma ação pré-sináptica da peçonha. Em preparação de nervo frênico-diafragma de camundongo, a peçonha (80 µg/mL) bloqueou as contrações por estímulos indiretos (95 ± 6% de bloqueio em 56 ± 28 minutos, n = 3). Uma maior potência de bloqueio foi observada em preparação de biventer cervicis de pintainho, onde 25 µg/mL causou 85 ± 4% de bloqueio de contrações indiretamente estimuladas em 52 ± 6 minutos (n = 4); a peçonha também produziu contratura estável. Além disso, as respostas contráteis desta preparação à Ach e KCl foram diminuídas de forma concentração-dependente pela peçonha. O fracionamento da peçonha resultou em dois grupos de proteínas ativas e um inativo tanto no edema quanto na atividade neuromuscular. Estes dados sugerem que ao menos duas toxinas são responsáveis pelo aumento da permeabilidade vascular local. Além disso, o fracionamento da peçonha indicou a presença de, no mínimo, duas toxinas neuromusculares com ações possivelmente de antagonismo nicotínico reversível e promoção de danos à estrutura funcional muscular, respectivamente. / Abstract: Vitalius dubius is a medium-sized, non-aggressive tarantula found in southeastern Brazil. In this work, we examined the histological organization of the venom apparatus of V. dubius and investigated some biochemical and pharmacological properties of this spider's venom. The venom apparatus consisted of two chelicerae fitted with large fangs for prey immobilization and venom injection. Each chelicera contained bundles of striated muscle involved in fang movement and also housed one venom gland that was surrounded by, but unattached to, these muscle bundles. The gland was closely associated with a helicoidally arranged muscle layer responsible for gland compression and venom extrusion through an inner fang duct that opened on the anterior face of the gland. Within the gland, an elastic basal membrane attached to muscles supported the secretory epithelium. This epithelium consisted of anastomosed cells, with peripheral nuclei and cytoplasmic elongations extending towards the gland lumen in an arrangement organized mainly by F-actin filaments. These elongations supported a complex network of vesicles and cisternae involved in venom biosynthesis. Ultrastructural analysis showed an abundance of organelles involved in protein synthesis, including smooth and rough endoplasmic reticulum, Golgi apparatus, mitochondria and lysosomes. Nuclei with evident nucleoli were seen. During venom production, the main ultrastructural changes were epithelial compactation, greater organelle abundance and alterations in nuclear shape. Venom was milked regularly by electrical stimulation. In absolute terms, females yielded more venom than males [23.1+2.3 mg (n=11) versus 12.5+0.7 mg (n=16) of venom/spider/milking], although when expressed in terms of body weight, males had slightly but significantly greater yields. Venom yield decreased with successive milkings and with spider age. SDS-PAGE showed that the venom contained few high molecular mass proteins, but a variety of small molecules (peptides). The venom was devoid of proteases but contained considerable hyaluronidase activity (estimated molecular mass: 45 kDa). ELISA showed that the venom reacted with immunoglobulins from commercial anti-arachnid antivenom raised against the venoms of Loxosceles gaucho (spider), Phoneutria nigriventer (spider) and Tityus serrulatus (scorpion). Immunoblotting showed that only venom components >30 kDa were responsible for this immunoreactivity. Vitalius dubius venom had no hemolytic activity but was cytotoxic to cultured leukemic cells (up to 300 µg/mL). The venom caused potent, dose-dependent (0.1-100 µg/site) dorsal skin edema in rats that was mediated by serotonin and nitric oxide but not by bradykinin or histamine. The edema-forming activity was not neutralized by commercial anti-arachnid antivenom. The venom (100 µg) was weakly cardiotoxic in the cockroach isolated heart and did not contract non-vascular smooth muscle (isolated guinea pig ileum and rat anoccocygeus), nor did it significantly alter the contractile responses to a variety of agonists in these preparations. However, electrically-induced muscle contractures in the anoccocygeus were attenuated by co-incubation with the venom. Reversible neuromuscular blockade was seen in indirectly stimulated chick biventer cervicis preparations (10-50 µg/mL), with a less potent action in mouse phrenic nerve-diaphragm preparations (at 80 µg/mL). Attenuation of the responses to exogenous acetylcholine (110 µM) and KCl (20 mM) in avian preparations suggested that the venom affected postsynaptic nicotinic receptors and had a direct action on muscle. Marked muscle contracture was also seen with the venom. Fractionation of the venom by reverse-phase chromatography yielded three major groups of proteins, two of which produced both edema and neuromuscular blockade while the third was inactive in these assays. These findings indicate that V. dubius venom contains at least two toxins that cause edema and/or produce neuromuscular blockade. / Doutorado / Biologia Celular / Doutor em Biologia Celular e Estrutural

"Inscriptions of Poison" is an ethnographic, textual, and aesthetic engagement with possession, pollution, and the temporalities of poison in contemporary Italy’s postindustrial South. Drawing on extensive fieldwork in the city of Taranto (Puglia)—one of Europe’s most polluted cities—as well as archival work on Ernesto De Martino’s anthropology of possession rituals, this study of toxicity focuses on the southern Italian region of Puglia, which was the backdrop of two contrasting, yet interwoven histories of postwar modernization during the so-called “economic miracle” of the early 1960s. Puglia was the birthplace of the continent’s largest and most hazardous steel factory and simultaneously, the terrain of De Martino’s Gramscian anthropology of preindustrial folklore and agrarian rituals, yet the region’s role in industrial modernity and the study of ritual have rarely been examined in tandem. Re-reading the region’s intellectual and cultural past through a contemporary ethnography of industrial ruins, this dissertation interrogates the afterlives of possession in the ecological crisis of the present. For centuries, Italy’s South has been represented as “picturesque”—as the occluded of European modernity and the object of exoticization, folklorization, and racism. The environmental devastation and exposure these landscapes endure today cannot be thought outside their longstanding exploitation facilitated by this image as the nation’s “internal other.” Informed by these representations, contemporary environmental discourses amplify an image of a poisoned South, perceived as the source of pollution, rather than its victim. Intervening in the longue durée of this representational history, the dissertation explores a central fragment of Puglia’s cultural history of illness and healing: the possession ritual of tarantismo, traditionally performed by women to expel the poison of a tarantula. This ethnography of Taranto’s environmental catastrophe rethinks tarantismo in the present, as both a continued exposure to illness and the displacement of traditional methods for dealing with environmental risk. Drawing on De Martino’s work on the ritual, including his canonical work "The Land of Remorse" ("La terra del rimorso") (1961), as well as the archive of his fieldwork in Puglia, this study reads his corpus against the grain, finding it a philosophical account of “crisis of presence” that is mobilized as an analytic lens for the region’s current environmental catastrophe. This re-reading follows the trajectories of poison ethnographically, in its most varied material and affective forms: the venom of tarantulas, cloud-like dioxin emissions, contaminated milk, photographs of glittering iron ore dust, and the concealment of a wig. A central task of the work is thus to consider the intermedial relations between text, image, and theory, alongside toxic matter—to incorporate an intellectual history as the discursive part of a “material-discursive” analysis of ecological crisis. These interrelations are performatively engaged in the dissertation’s experimental use of text and image, while informing an understanding of toxicity as a material and metaphorical form inscribed (and remediated) through different media. By examining images and imaginaries of poison in Puglia, this ethnographic study of the aesthetics of toxicity demonstrates that the sensory field of environmental catastrophe affords a privileged terrain of political struggle. Intervening in current debates in ecocriticism and environmental humanities about the role of art and aesthetics in re-imagining human/nonhuman relations in an ecologically unstable world, "Inscriptions of Poison" analyzes the potency of industrial poison, while simultaneously revealing the bodily, psychological, religious, and aesthetic strategies deployed by the people of Taranto to understand, live with, and survive it.