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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

'n Ondersoek na die fisiologiese werking van die gif van die rinkals (Hemachatus haemachatus)

Willemse, Gert Thomas 18 February 2014 (has links)
M.Sc. / Comparative electrophoretic studies at pH8,5 was conducted on the venom of the rinkals (Hemachatus haemachatus), Egyptian cobra (Naja haje haje) and puff-adder (Bitis arietans). The physiological effect of fresh freeze-dried venom of the rinkals was compared with that of various commercial samples of venom obtained from the same species of snake. Furthermore, the stability of dried snake venom under different conditions of storing was investigated. The electrophoretic, as well as the physiological results, indicated significant differences in the characteristics of fresh freeze-dried snake venom and the various commercial samples of venom obtained from the same species of snake. The electrophoretic results also show that freeze-dried venom, stored under the conditions described, is of somewhat unstable character and therefore the venom undergoes changes in its electrophoretic characteristics. A decline or increase of the total percentage of protein of the anodal and cathodal fractions, depending on the type of venom, was observed and is being regarded as being a function of the degeneration of the venom...
12

An evaluation of the homoeopathic drug proving of Naja Mossambica in the light of a doctrine of signatures analysis and a comparison between the proving symptons and the venom toxicology

Taylor, Liesel January 2004 (has links)
Thesis (M.Tech.: Homoeopathy)-Dept of Homoeopathy, Durban Institute of Technology, 2004 xiv, 154 leaves : ill. ; 30 cm / This study was conducted by administering Naja mossambica 30CH (a homoeopathic remedy derived from the venom of the Mozambican spitting cobra) to healthy individuals in order to elicit and document the resulting mental and physical symptomology. These symptoms were compared to the toxicology of Naja mossambica venom as well as a doctrine of signatures analysis of the snake in order to expand and clarify the remedy picture. Existing knowledge of the venom toxicology gives a clear indication of the organs and body systems that the substance has an affinity for. Many poisonous substances used homoeopathically rely heavily on inferences made from the toxicology of the substance, as much of the gross pathology in the symptom picture cannot safely be elucidated in a proving. The aim of this study was to determine the sphere of action of Naja mossambica by utilising symptoms obtained from the proving and from the toxicology of the venom. This was done in order to determine the remedy's usefulness in a homoeopathic clinical setting by expanding our understanding of the substance and thereby facilitating the treatment of disease based on the law of similars.
13

A homoeopathic drug proving of Bitis atropos with a subsequent comparison to venom toxicology and related remedies

Brijnath, Shraddha 28 May 2014 (has links)
Submitted in partial compliance with the requirements of the Master’s Degree in Technology: Homoeopathy, Durban University of Technology. 2013. / This study was a homoeopathic drug proving of Bitis atropos 30CH (derived from Berg adder venom) with a subsequent comparison of the proving symptoms to known venom toxicology and existing remedies from the materia medica, that on repertorisation, yielded the greatest similarities in the Mental, General, Physical and unique symptomatology of Bitis atropos. Methodology : The proving was carried out in the form of a double-blinded, placebo controlled trial on healthy subjects who were administered the proving substance or placebo. The resultant influence of this substance on the health of provers (i.e. symptoms produced) was recorded in journal format and formed the materia medica and ultimately the clinical indications thereof according to the Law of Similars. Twenty eight healthy consenting provers who meet the inclusion criteria (Appendix B), were randomly split into two groups, one being the experimental group comprising 22 provers, and the other a placebo control group comprising 6 provers. This was further split between the researcher and co-researcher, each responsible for 11 provers receiving verum and 3 receiving placebo. The researchers and the individual provers were unaware of their respective group allocation and the provers were unaware of the identity of the proving substance. The fresh venom sourced from a wild, Berg adder, was processed according to the German Homoeopathic Pharmacopoeia (Appendix G) to produce the 30CH Homoeopathic potency thereof. Six lactose powders were dispensed to each prover (either placebo or verum) and taken sublingually three times a day or until the onset of symptoms. Symptoms were recorded by the provers in journals over 4 weeks and were closely supervised by the researcher. When the symptoms subsided, the combined journals were collected, collated, analysed, interpreted and validated. Accepted symptoms were converted to materia medica and Repertory format. Results : The proving yielded a total of 903 rubrics, of which 18 were newly created. The systems mostly affected were Dreams, Mind, Head and Eye. Comparison of proving symptoms to that of venom toxicology, as seen in case studies of envenomation by Bitis atropos, yielded similar results, as the sensations experienced in provers closely matched that of known venom toxicology. On repertorisation of the proving symptoms, the existing remedies that were closely related were Sepia officinalis, Lachesis mutus and Argentum nitricum. Further repertorisation of toxicological symptoms indicated a further relation to Belladonna, Natrum muriaticum and Hyoscyamus niger. Conclusion : Clearly observable signs and symptoms were produced by healthy provers in response to administration of Bitis atropos 30CH, in addition there was a significant degree of similarity between proving symptoms and that of known toxicology of the crude substance. The researcher identified Sepia officinalis, Lachesis mutis and Argentum nitricum as the three most similar existing homoeopathic remedies and a detailed comparison thereof was conducted. A further repertorisation of the toxicological symptoms of envenomation by the snake, yielded the remedies Belladonna, Natrum muriaticum and Hyoscyamus niger which were also compared to Bitis atropos.
14

A pharmacological characterisation of death adder (Acanthophis Spp.) venoms and toxins

Wickramaratna, Janith C. January 2003 (has links)
Abstract not available
15

An evaluation of the homoeopathic drug proving of Naja Mossambica in the light of a doctrine of signatures analysis and a comparison between the proving symptons and the venom toxicology

Taylor, Liesel January 2004 (has links)
Thesis (M.Tech.: Homoeopathy)-Dept of Homoeopathy, Durban Institute of Technology, 2004 xiv, 154 leaves : ill. ; 30 cm / This study was conducted by administering Naja mossambica 30CH (a homoeopathic remedy derived from the venom of the Mozambican spitting cobra) to healthy individuals in order to elicit and document the resulting mental and physical symptomology. These symptoms were compared to the toxicology of Naja mossambica venom as well as a doctrine of signatures analysis of the snake in order to expand and clarify the remedy picture. Existing knowledge of the venom toxicology gives a clear indication of the organs and body systems that the substance has an affinity for. Many poisonous substances used homoeopathically rely heavily on inferences made from the toxicology of the substance, as much of the gross pathology in the symptom picture cannot safely be elucidated in a proving. The aim of this study was to determine the sphere of action of Naja mossambica by utilising symptoms obtained from the proving and from the toxicology of the venom. This was done in order to determine the remedy's usefulness in a homoeopathic clinical setting by expanding our understanding of the substance and thereby facilitating the treatment of disease based on the law of similars.
16

Estudos estruturais com fosfolipases A2 homólogas de veneno botrópicos em presença de íons com importância funcional /

Borges, Rafael Junqueira. January 2012 (has links)
Orientador: Marcos Roberto de Mattos Fontes / Banca: Pedro de Magalhães Padilha / Banca: Leonardo de Castro Palmieri / Resumo: As fosfolipases A2 (PLA2s) de veneno de serpente são uma das principais toxinas responsavéis pela miotoxicidade e necrose muscular observadas nos acidentes ofídicos. Essas toxinas podem ser separadas em Asp49-PLA2s, cujo mecanismo é catalítico e dependente de cálcio, e as PLA2s homólogas, cuja estrutura é semelhante, porém atividade em mecanismo não catalítico e independente de cálcio. Apesar de os detalhes deste mecanismo não serem bem conhecidos, estudos funcionais ressaltam importância da região do C-terminal e estudos cristalográficos propõem, mais especificamente, um sítio miotóxico composto por resíduos básicos e um hydrophobic knuckle composto por hidrofóbicos, ambos situados na região C-terminal da toxina. O presente trabalho tem objetivo de oferecer mais detalhes acerca do mecanismo de ação miotóxico independente de cálcio. Para tanto, realizamos estudos cristalográficos com miotoxinas botrópicas BthTX-II (uma Asp- PLA2s), BthTX-I e PrTX-I (duas PLA2s homólogas), em presença de íons relevantes para suas atividades. Recentemente, foi demonstrado que íons, tal como manganês, cálcio, zinco entre outros, interferem na atividade biológica de PLA2s e PLA2s homólogas. Assim, estudo cristalográfico da PrTX-I e BthTX-I com íons manganês e zinco foram elucidados no estado nativo e complexado. Experimentos in vivo indicam que tais íons promoveriam efeito inibitório da miotoxicidade. Enquanto os íons manganês não foram localizados no modelo cristalográfico, os íons zinco foram identificados interagindo apenas no modelo nativo com uma His48 e com as His120 de ambos monômeros. Estudos comparativos destas estruturas com a PrTX-II (PLA2s homóloga) com ácidos graxos foi desenvolvido e guiaram para elaboração de nova hipótese do mecanismo de ação independente de... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Phospholipases A2 (PLA2s) from snake venom are among the main toxins responsibles for miotoxicity and muscular necrosis observed in offidic accidents. These toxins can be separated in Asp49-PLA2s, whose catalytic mechanism of action is dependent of calcium, and in homologue PLA2s or PLA2s-like, whose terciary structure is similar, although its activity is not catalytic in a calcium independent mechanism of action. Despite the fact that this calcium independent mechanism is not well known, functional studies highlight the C-terminal region and structural studies points to a myotoxic site, composed by basic residues, and a hydrophobic knuckle, composed by aromatic and hydrophobic, in the C-terminal region. The present study aims to gather more knowledge about this myotoxic calcium independent mechanism of action. For this purpose, the botropic myotoxins BthTX-II (an Asp49- PLA2), BthTX-I and PrTX-I (homologue PLA2s) were studied in the presence of divalent ions by Xray crystallography. Recently, it was demonstrated divalent ions, such as manganese, zinc and calcium, interfere with the biological activity of these toxins. The crystallographic structure of PrTX-I and BthTX-I with manganese and zinc ions in a native and complexed form were elucidated. In vivo studies demonstrated that these ions inhibit the myotoxic activity of these proteins. Although manganese ions were not found in the structures, zinc ions were found interacting with His48 and the C-terminal residue His120. Comparative studies of this structure and PrTX-II (a homologue PLA2) complexed with stearic acid were performed and support a new hypothesis for the myotoxic mechanism of action for homologue PLA2s which includes both myotoxic site and hydrophobic knuckle and, for the first time, His120. Differently from most PLA2s of snake venom... (Complete abstract click electronic access below) / Mestre
17

Estudos estruturais e filogenéticos com fosfolipases e serino proteases de venenos de serpentes botrópicas nativas e quimicamente modificadas /

Fernandes, Carlos Alexandre Henrique. January 2009 (has links)
Orientador: Marcos Roberto de Mattos Fontes / Banca: Richard Charles Garrat / Banca: Antonio José da Costa Filho / Resumo: As serpentes do gênero Bothrops são de grande interesse científico, médico e social para o Brasil, visto que este gênero é responsável por cerca de 90% dos acidentes ofídicos que ocorrem em nosso país. Dois dos principais componentes do veneno desses animais são as fosfolipases A2 e as serino proteases. As fosfolipases A2 são enzimas responsáveis pela destruição da membrana celular através da hidrólise de fosfolipídios Ca2+ dependente. Uma classe destas fosfolipases, as fosfolipases homólogas (Lys49-PLA2s), que se caracteriza pela uma substituição natural na posição 49 de um resíduo de Asp para um resíduo de Lys, não apresenta atividade catalítica, mas é capaz de induzir mionecrose por um mecanismo Ca2+ independente devido, provavelmente, à resíduos da região C-terminal. Neste trabalho, através de estudos por cristalografia de raios-X de Lys49-PLA2s botrópicas nativas e quimicamente modificadas pelo brometo de p-bromofenacila (BPB), revisamos a posição da Lys122 - anteriormente apontado como um dos responsáveis ela ausência da atividade catalítica das Lys49-PLA2s por conta da hiperpolarização que causaria na ligação peptídica Cys29/Gly30 - e concluímos que, por conta de esta hiperpolarização ocorrer apenas em alguns monômeros de Lys49-PLA2s complexadas, a Lys122 não deve estar envolvida no "bloqueio" da atividade catalítica. Além disso, a comparação estrutural do loop de ligação de Ca2+ entre as Lys49 e Asp49-PLA2s nos mostra a importância da conservação da Tyr28 dentre as Asp49-PLA2s para a integridade do loop de ligação do Ca2+. Este resíduo estabiliza essa região através de uma ponte de hidrogênio com a Gly35. Nas Lys49-PLA2s, que possuem um resíduo de Asn na posição 28, não ocorre a formação dessa ponte, o que contribuiria para a desestabilização dessa região nessas proteínas ...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The snakes from Botrops genus are objects with great scientific, medical and social interesting since that these snakes are responsible of 90% of snakebites in our country. Two of the main components of the venom from these animals are the phospholipases A2 and the serine proteases. The phospholipases A2 are enzymes responsible of cellular membrane disruption through phospholipids hydrolysis Ca2+-dependent. A class of these phospholipases, the homolog phospholipases (Lys49-PLA2s) that underwent a natural substitution Lys to Asp substitution in 49 position, does not show catalytic activity. However, these proteins can perform myonecrosis by a Ca2+-independent mechanism probably, due to action of C-termini region residues. In this work, by x-ray crystallography studies with bothropic Lys49-PLA2s in native and chemically modified by p-bromophenacyl bromide (BPB) forms, we revised the position of Lys122, previously pointed as one of the responsibles of Lys49-PLA2s due to hiperpolarization of its side chain on Cys29/Cys30 peptide bond. Here, we conclude that this hiperpolarization are present only in a few monomers and thus, Lys122 may not be involved in the "blocking" of catalytic activity. Furthermore, structural comparisons of Ca2+ binding loop between Lys49 and Asp49-PLA2s revels the importance of the Tyr28 residue conservation to the integrity of this region. This residue stabilizes the Ca2+ binding loop by a hydrogen bond to Gly35. In Lys49-PLA2s that have an Asn residue in 28 position, does not occur the formation of this bond, contributing to unstabilization of this region and difficulting the binding of Ca2+ cofactor. Phylogenetic studies showed that Asp49- PLA2s with reduced catalytic inactivity and capable to induce myonecrosis are phylogenetic more related to Lys49-PLA2s than to others Asp49-PLA2s, forming a ...(Complete abstract click electronic access below) / Mestre
18

Estudos estruturais com fosfolipases A2 homólogas de veneno botrópicos em presença de íons com importância funcional

Borges, Rafael Junqueira [UNESP] 16 March 2012 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:26:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-03-16Bitstream added on 2014-06-13T18:29:21Z : No. of bitstreams: 1 borges_rj_me_botib.pdf: 1192920 bytes, checksum: 1ec44a09797fef66642b2e78f1373280 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / As fosfolipases A2 (PLA2s) de veneno de serpente são uma das principais toxinas responsavéis pela miotoxicidade e necrose muscular observadas nos acidentes ofídicos. Essas toxinas podem ser separadas em Asp49-PLA2s, cujo mecanismo é catalítico e dependente de cálcio, e as PLA2s homólogas, cuja estrutura é semelhante, porém atividade em mecanismo não catalítico e independente de cálcio. Apesar de os detalhes deste mecanismo não serem bem conhecidos, estudos funcionais ressaltam importância da região do C-terminal e estudos cristalográficos propõem, mais especificamente, um sítio miotóxico composto por resíduos básicos e um hydrophobic knuckle composto por hidrofóbicos, ambos situados na região C-terminal da toxina. O presente trabalho tem objetivo de oferecer mais detalhes acerca do mecanismo de ação miotóxico independente de cálcio. Para tanto, realizamos estudos cristalográficos com miotoxinas botrópicas BthTX-II (uma Asp- PLA2s), BthTX-I e PrTX-I (duas PLA2s homólogas), em presença de íons relevantes para suas atividades. Recentemente, foi demonstrado que íons, tal como manganês, cálcio, zinco entre outros, interferem na atividade biológica de PLA2s e PLA2s homólogas. Assim, estudo cristalográfico da PrTX-I e BthTX-I com íons manganês e zinco foram elucidados no estado nativo e complexado. Experimentos in vivo indicam que tais íons promoveriam efeito inibitório da miotoxicidade. Enquanto os íons manganês não foram localizados no modelo cristalográfico, os íons zinco foram identificados interagindo apenas no modelo nativo com uma His48 e com as His120 de ambos monômeros. Estudos comparativos destas estruturas com a PrTX-II (PLA2s homóloga) com ácidos graxos foi desenvolvido e guiaram para elaboração de nova hipótese do mecanismo de ação independente de... / Phospholipases A2 (PLA2s) from snake venom are among the main toxins responsibles for miotoxicity and muscular necrosis observed in offidic accidents. These toxins can be separated in Asp49-PLA2s, whose catalytic mechanism of action is dependent of calcium, and in homologue PLA2s or PLA2s-like, whose terciary structure is similar, although its activity is not catalytic in a calcium independent mechanism of action. Despite the fact that this calcium independent mechanism is not well known, functional studies highlight the C-terminal region and structural studies points to a myotoxic site, composed by basic residues, and a hydrophobic knuckle, composed by aromatic and hydrophobic, in the C-terminal region. The present study aims to gather more knowledge about this myotoxic calcium independent mechanism of action. For this purpose, the botropic myotoxins BthTX-II (an Asp49- PLA2), BthTX-I and PrTX-I (homologue PLA2s) were studied in the presence of divalent ions by Xray crystallography. Recently, it was demonstrated divalent ions, such as manganese, zinc and calcium, interfere with the biological activity of these toxins. The crystallographic structure of PrTX-I and BthTX-I with manganese and zinc ions in a native and complexed form were elucidated. In vivo studies demonstrated that these ions inhibit the myotoxic activity of these proteins. Although manganese ions were not found in the structures, zinc ions were found interacting with His48 and the C-terminal residue His120. Comparative studies of this structure and PrTX-II (a homologue PLA2) complexed with stearic acid were performed and support a new hypothesis for the myotoxic mechanism of action for homologue PLA2s which includes both myotoxic site and hydrophobic knuckle and, for the first time, His120. Differently from most PLA2s of snake venom... (Complete abstract click electronic access below)
19

Estudos estruturais e filogenéticos com fosfolipases e serino proteases de venenos de serpentes botrópicas nativas e quimicamente modificadas

Fernandes, Carlos Alexandre Henrique [UNESP] 16 September 2009 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:26:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-09-16Bitstream added on 2014-06-13T20:33:38Z : No. of bitstreams: 1 fernandes_cah_me_botib.pdf: 1288061 bytes, checksum: 481773a993e5e2c2a2095ba6bcf346cc (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / As serpentes do gênero Bothrops são de grande interesse científico, médico e social para o Brasil, visto que este gênero é responsável por cerca de 90% dos acidentes ofídicos que ocorrem em nosso país. Dois dos principais componentes do veneno desses animais são as fosfolipases A2 e as serino proteases. As fosfolipases A2 são enzimas responsáveis pela destruição da membrana celular através da hidrólise de fosfolipídios Ca2+ dependente. Uma classe destas fosfolipases, as fosfolipases homólogas (Lys49-PLA2s), que se caracteriza pela uma substituição natural na posição 49 de um resíduo de Asp para um resíduo de Lys, não apresenta atividade catalítica, mas é capaz de induzir mionecrose por um mecanismo Ca2+ independente devido, provavelmente, à resíduos da região C-terminal. Neste trabalho, através de estudos por cristalografia de raios-X de Lys49-PLA2s botrópicas nativas e quimicamente modificadas pelo brometo de p-bromofenacila (BPB), revisamos a posição da Lys122 – anteriormente apontado como um dos responsáveis ela ausência da atividade catalítica das Lys49-PLA2s por conta da hiperpolarização que causaria na ligação peptídica Cys29/Gly30 – e concluímos que, por conta de esta hiperpolarização ocorrer apenas em alguns monômeros de Lys49-PLA2s complexadas, a Lys122 não deve estar envolvida no “bloqueio” da atividade catalítica. Além disso, a comparação estrutural do loop de ligação de Ca2+ entre as Lys49 e Asp49-PLA2s nos mostra a importância da conservação da Tyr28 dentre as Asp49-PLA2s para a integridade do loop de ligação do Ca2+. Este resíduo estabiliza essa região através de uma ponte de hidrogênio com a Gly35. Nas Lys49-PLA2s, que possuem um resíduo de Asn na posição 28, não ocorre a formação dessa ponte, o que contribuiria para a desestabilização dessa região nessas proteínas... / The snakes from Botrops genus are objects with great scientific, medical and social interesting since that these snakes are responsible of 90% of snakebites in our country. Two of the main components of the venom from these animals are the phospholipases A2 and the serine proteases. The phospholipases A2 are enzymes responsible of cellular membrane disruption through phospholipids hydrolysis Ca2+-dependent. A class of these phospholipases, the homolog phospholipases (Lys49-PLA2s) that underwent a natural substitution Lys to Asp substitution in 49 position, does not show catalytic activity. However, these proteins can perform myonecrosis by a Ca2+-independent mechanism probably, due to action of C-termini region residues. In this work, by x-ray crystallography studies with bothropic Lys49-PLA2s in native and chemically modified by p-bromophenacyl bromide (BPB) forms, we revised the position of Lys122, previously pointed as one of the responsibles of Lys49-PLA2s due to hiperpolarization of its side chain on Cys29/Cys30 peptide bond. Here, we conclude that this hiperpolarization are present only in a few monomers and thus, Lys122 may not be involved in the “blocking” of catalytic activity. Furthermore, structural comparisons of Ca2+ binding loop between Lys49 and Asp49-PLA2s revels the importance of the Tyr28 residue conservation to the integrity of this region. This residue stabilizes the Ca2+ binding loop by a hydrogen bond to Gly35. In Lys49-PLA2s that have an Asn residue in 28 position, does not occur the formation of this bond, contributing to unstabilization of this region and difficulting the binding of Ca2+ cofactor. Phylogenetic studies showed that Asp49- PLA2s with reduced catalytic inactivity and capable to induce myonecrosis are phylogenetic more related to Lys49-PLA2s than to others Asp49-PLA2s, forming a ...(Complete abstract click electronic access below)
20

Manejo de serpentes em cativeiro : análise da infraesrutura, saúde animal e enfermidades virais e parasitárias /

Paiva, Maria Isabel Sousa. January 2015 (has links)
Orientador: Benedito Barravieira / Coorientador: João Pessoa Araújo Júnior / Banca: Reinaldo José da Silva / Banca: Francisco Luis Franco / Resumo: / Abstract: / Mestre

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