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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.
1

Neurocisticercose experimental: efeito do tratamento anti-helmíntico no metabolismo energético e respiratório de cisticercos

Leandro, Letícia de Almeida 28 February 2013 (has links)
Submitted by Erika Demachki (erikademachki@gmail.com) on 2014-12-29T15:35:49Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação - Letícia de Almeida Leandro - 2013.pdf: 2111763 bytes, checksum: c992b02afb4a59e318265d06577e6454 (MD5) / Approved for entry into archive by Erika Demachki (erikademachki@gmail.com) on 2014-12-29T15:40:58Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação - Letícia de Almeida Leandro - 2013.pdf: 2111763 bytes, checksum: c992b02afb4a59e318265d06577e6454 (MD5) / Made available in DSpace on 2014-12-29T15:40:58Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação - Letícia de Almeida Leandro - 2013.pdf: 2111763 bytes, checksum: c992b02afb4a59e318265d06577e6454 (MD5) Previous issue date: 2013-02-28 / The analysis of the energetic and respiratory metabolism of Taenia crassiceps cysticerci innoculated into the encefalum of female BALB/c mice was performed. After 30 days of infection the mice were treated with low dosages (3.0 and 6.0 mg/kg) of albendazole and praziquantel aiming the observation of the alterations caused by a hostile environment on the parasite's metabolism. The aim of this study was to detect the influence of low dosages of anti-helminthic drugs on the production of organic acids related to the intermediary metabolism (oxaloacetate, malate, fumarate, succinate, citrate and α-ketoglutarate), carbohydrates metabolism (pyruvate, lactate, propionate, oxaloacetate and malate) and fatty acids and proteins catabolism (β-hydroxibutyrate, acetoacetate, acetate, α-ketoglutarate and oxalate) by T. crassiceps cysticerci innoculated into the CNS of BALB/c mice. Regarding the glycolisis, it was possible to detect lactate in all samples which shows that this parasite performs a lactic fermentation. As to the intermediary metabolism it was possible to detect oxaloacetate, citrate, malate, succinate, fumarate and α-ketoglutarate which indicates that the cysticerci may have used the tricarboxilic acid cycle (TCA) to produce energy. However facing the results found the evidences show that the cysticerci used a metabolic pathway denominated reversion of the TCA for energy production which presents as main end products propionate and acetate. There were no significant differences between the groups treated with the anti-helminthic and the control one except that the group treated with 6.0 mg/kg of albendazole presented acetate as main end product of the TCA reversion while the other groups presented propionate. In the groups treated with praziquantel, both concentrations, there was no production of acetate and in the 6.0 mg/kg of praziquntel there was no production of β-hydroxibutyrate wheter in the groups treated with both concentrations of albendazol there was an increase in the production of this organic acid which indicates the maximization of the energetic pathway of fatty acids oxidation and/or of the proteic catabolism. It was possible to conclude that T. crassiceps cysticerci when exposed to the conditions of this study preferred an anaerobic energy production pathway and probably performed the catabolism of carbohydrates, proteins and fatty acids. / Realizou-se a análise do metabolismo energético e respiratório de cisticercos de Taenia crassiceps inoculados no encéfalo de camundongos BALB/c fêmeas. Após 30 dias de infecção, esses camundongos foram tratados com baixas doses (3,0 e 6,0 mg/kg) de albendazol e praziquantel visando observação de alterações provocadas no metabolismo do parasito. O objetivo deste trabalho foi detectar a influência de baixas doses desses anti-helmínticos na produção dos ácidos orgânicos do metabolismo intermediário (citrato, α-cetoglutarato, succinato, fumarato, malato, oxaloacetato), de carboidratos (piruvato, lactato, oxaloacetato, malato, acetato e propionato), de ácidos graxos e proteínas (β-hidroxibutirato, acetoacetato, acetato, α-cetoglutarato e oxalato) realizados por cisticercos de T. crassiceps implantados no SNC de camundongos BALB/c fêmeas. Com relação a glicólise, detectou-se lactato em todas as amostras mostrando que esse parasito fez fermentação lática; em relação ao metabolismo intermediário foi possível detectar os ácidos orgânicos citrato, α-cetoglutarato, succinato, fumarato, malato e oxaloacetato, indicando que os cisticercos apresentaram elementos do ciclo do ácido cítrico para produzir energia. Porém diante dos resultados encontrados a principal evidência é de que esses cisticercos utilizaram uma via denominada reversão do ciclo do ácido cítrico para produzirem energia, obtendo como produtos finais propionato e acetato. Não se observou diferenças significativas entre os grupos que sofreram tratamentos e os grupos controle exceto pelo fato de que, o grupo tratado com albendazol 6,0 mg/kg de peso do camundongo teve como principal produto final da reversão do ciclo do ácido cítrico, o acetato, ao contrário dos demais grupos que tiveram o propionato; nos grupos tratados com praziquantel não houveram a produção de acetato como nos demais grupos e no grupo tratado com praziquantel 6,0 mg/kg não houve a produção de β-hidroxibutirato; nos grupos tratados com albendazol observou-se um aumento na produção de β-hidroxibutirato indicando que esse grupo maximizou a via de produção energética através da β-oxidação de ácidos graxos e/ou através do catabolismo proteico.Concluímos que os cisticercos de T. crassiceps, nas condições do presente trabalho, deram preferência para uma via de produção energética anaeróbia e provavelmente catabolizaram, além de carboidratos, proteínas e ácidos graxos para produzirem ATP.
2

Respiratory Metabolism and Energy Requirements of Embryo, Larval and Juvenile Mountain Whitefish, Prosopium Williamsoni

Rajagopal, Pokkavil Karunakara 01 May 1975 (has links)
The upper optimum temperature for embryonic development of mountain whitefish is 6 C, and for the post yolk sac stage is 9 to 12 C. The need to know effects on all stages in the life cycle in cases of thermal pollution is demonstrated. Abnormalities caused by thermal pollution in hatched larvae were agape jaws, coloboma or fissure of the eye, monophthalmia or the presence of only one eye, monomicrophthalmia or the presence of one small eye and one case of twinning. High mortalities of eggs occurred at 9 C and higher. Study of the energy expenditure, by the dry weight method showed an energy deficit at 6 and 9 Cat the time of hatching. The larvae are then fully capable of offsetting these deficits by feeding. The oxygen consumption method showed an energy deficit during hatching at 6 C, but failed to show any at 9 C. The efficiency of yolk conversion generally decreased as development progressed. No group effect in active metabolism was observed in the underyearlings. The electrochemical method of measuring oxygen consumption of embryos gave a cumulative value which was 6.8% higher than values obtained using the manometric method. This increase is attributed to the increase in activity of embryos caused by the nature of the experimental set up. Active metabolism and scope for activity were high at 9 and 12 C compared to 6 and 15 C. Standard metabolism steeply increased at 1:5 C. There was very little scope for activity at 15 C. The embryonic development was similar to that of other whitefishes. The mountain whitefish requires more thermal units to reach corresponding stages than does the lake whitefish, after the stage when the blastodisc is prominantly raised up on the yolk.
3

Metabolismo respiratório de bradirrizóbios em processos "in vitro" e simbióticos analisado por PCR quantitativo em tempo real /

Moreira, Wellington Marcelo Queixas. January 2009 (has links)
Resumo: O Brasil é o segundo maior produtor de soja no mundo, cuja cultura requer o elemento nitrogênio em quantidades elevadas para manutenção do alto teor protéico dos grãos. A entrada de nitrogênio nos sistemas agrícolas pode ocorrer pela adição de fertilizantes nitrogenados ou por processos naturais como a Fixação Biológica do Nitrogênio, que se constitui como supridor de nitrogênio mais viável para a cultura da soja, tanto economicamente como ecologicamente. Este processo ocorre graças à simbiose que ocorre entre esta leguminosa e as bactérias do gênero Bradyrhizobium, resultando na formação de nódulos radiculares onde se dá a obtenção de todo o nitrogênio que a cultura necessita para alta produtividade. A introdução destas bactérias no solo se dá através da utilização de inoculantes comerciais, que incluem as bactérias Bradyrhizobium elkanii e Bradyrhizobium japonicum em sua composição. Aspectos relacionados à formulação e fabricação dos inoculantes comerciais reúnem os fatores mais importantes para a obtenção de um produto de qualidade, obedecendo à legislação vigente. Tendo em vista a análise de qualidade de inoculantes comerciais para soja em diferentes períodos de armazenamento, um estudo do metabolismo respiratório de bradirrizóbios foi realizado in vitro e em simbiose. Inoculantes comerciais com 12, 27 e 48 meses de idade foram analisados quanto suas características bioquímicas e fisiológicas, assim como testados em casa de vegetação. Adicionalmente, os mesmos testes foram realizados com Bradyrhizobium elkanii sob diferentes condições de oxigênio. Análise da expressão gênica indicou que um processo de expressão de genes relacionados à fixação biológica de nitrogênio (genes sensores a baixas tensões de oxigênio) foram expressos, entretanto não ocorrendo expressão do gene nifH, este só expresso em condições... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Brazil is the second major soybean producer in the world, whose culture requires the element nitrogen in large amounts for the maintenance of the high protein content in grains. The input of nitrogen in agricultural systems can occur by adding nitrogen fertilizer or by natural processes such as biological nitrogen fixation (BNF). BNF is the most feasible way to delivery nitrogen for the soybean crop, both economically and ecologically. This process occurs through the symbiosis between the legume and the bacteria of the genus Bradyrhizobium, resulting in the formation of root nodules where all nitrogen that the crop needs for high productivity is acquired. The introduction of these bacteria in soil is given by use of commercial inoculants, which include the bacteria Bradyrhizobium japonicum and Bradyrhizobium elkanii in its composition. Aspects related to formulation and manufacture of inoculants include the most important factors affecting the product quality, according to law. In order to analysis of the quality of commercial inoculants for soybean in different storage periods, a study of respiratory metabolism of bradyrhizobia was performed in vitro and in symbiosis. Inoculants with 12, 27 and 48 months old were analyzed accessing their biochemical and physiological characteristics, and tested at greenhouse. In addition, the same tests were conducted on cultures of Bradyrhizobium elkanii under different oxygen conditions. Analysis of gene expression have indicated that genes related to biological nitrogen fixation (genes sensors at low oxygen tension) were intensively expressed, but not occurring nifH gene expression which is only expressed under symbiosis. Similar data were found for the expression of these genes when B. elkanii grown at different oxygen tensions. These data indicate that as the oxygen level is reduced some genes related to nitrogen fixation are expressed... (Complete abstract click electronic access below) / Orientadora: Eliana Gertrudes de Macedo Lemos / Coorientador: Jackson Antônio Marcondes de Souza / Banca: Jesus Aparecido Ferro / Banca: Emanuel Maltempi de Souza / Mestre
4

Metabolismo respiratório de bradirrizóbios em processos “in vitro” e simbióticos analisado por PCR quantitativo em tempo real

Moreira, Wellington Marcelo Queixas [UNESP] 27 July 2009 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:27:23Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-07-27Bitstream added on 2014-06-13T20:35:48Z : No. of bitstreams: 1 moreira_wmq_me_jabo.pdf: 763719 bytes, checksum: 21d0bf3b9a629afa4e42b015a9f29722 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O Brasil é o segundo maior produtor de soja no mundo, cuja cultura requer o elemento nitrogênio em quantidades elevadas para manutenção do alto teor protéico dos grãos. A entrada de nitrogênio nos sistemas agrícolas pode ocorrer pela adição de fertilizantes nitrogenados ou por processos naturais como a Fixação Biológica do Nitrogênio, que se constitui como supridor de nitrogênio mais viável para a cultura da soja, tanto economicamente como ecologicamente. Este processo ocorre graças à simbiose que ocorre entre esta leguminosa e as bactérias do gênero Bradyrhizobium, resultando na formação de nódulos radiculares onde se dá a obtenção de todo o nitrogênio que a cultura necessita para alta produtividade. A introdução destas bactérias no solo se dá através da utilização de inoculantes comerciais, que incluem as bactérias Bradyrhizobium elkanii e Bradyrhizobium japonicum em sua composição. Aspectos relacionados à formulação e fabricação dos inoculantes comerciais reúnem os fatores mais importantes para a obtenção de um produto de qualidade, obedecendo à legislação vigente. Tendo em vista a análise de qualidade de inoculantes comerciais para soja em diferentes períodos de armazenamento, um estudo do metabolismo respiratório de bradirrizóbios foi realizado in vitro e em simbiose. Inoculantes comerciais com 12, 27 e 48 meses de idade foram analisados quanto suas características bioquímicas e fisiológicas, assim como testados em casa de vegetação. Adicionalmente, os mesmos testes foram realizados com Bradyrhizobium elkanii sob diferentes condições de oxigênio. Análise da expressão gênica indicou que um processo de expressão de genes relacionados à fixação biológica de nitrogênio (genes sensores a baixas tensões de oxigênio) foram expressos, entretanto não ocorrendo expressão do gene nifH, este só expresso em condições... / Brazil is the second major soybean producer in the world, whose culture requires the element nitrogen in large amounts for the maintenance of the high protein content in grains. The input of nitrogen in agricultural systems can occur by adding nitrogen fertilizer or by natural processes such as biological nitrogen fixation (BNF). BNF is the most feasible way to delivery nitrogen for the soybean crop, both economically and ecologically. This process occurs through the symbiosis between the legume and the bacteria of the genus Bradyrhizobium, resulting in the formation of root nodules where all nitrogen that the crop needs for high productivity is acquired. The introduction of these bacteria in soil is given by use of commercial inoculants, which include the bacteria Bradyrhizobium japonicum and Bradyrhizobium elkanii in its composition. Aspects related to formulation and manufacture of inoculants include the most important factors affecting the product quality, according to law. In order to analysis of the quality of commercial inoculants for soybean in different storage periods, a study of respiratory metabolism of bradyrhizobia was performed in vitro and in symbiosis. Inoculants with 12, 27 and 48 months old were analyzed accessing their biochemical and physiological characteristics, and tested at greenhouse. In addition, the same tests were conducted on cultures of Bradyrhizobium elkanii under different oxygen conditions. Analysis of gene expression have indicated that genes related to biological nitrogen fixation (genes sensors at low oxygen tension) were intensively expressed, but not occurring nifH gene expression which is only expressed under symbiosis. Similar data were found for the expression of these genes when B. elkanii grown at different oxygen tensions. These data indicate that as the oxygen level is reduced some genes related to nitrogen fixation are expressed... (Complete abstract click electronic access below)
5

Impact of varying NH₄⁺˸NO₃⁻ ratios in nutrient solution on C-isotope composition of leaf- and root-respired CO₂ and putative respiratory substrates in C₃ plants / Impact de divers rapports NH₄⁺ ˸NO₃⁻ dans une solution nutritive sur la composition en isotopique (¹³C/¹²C) du CO₂ respiré par les feuilles et les racines et les substrats respiratoires putatifs chez les plantes C₃

Xia, Yang 23 July 2019 (has links)
La composition isotopique (¹³C/¹²C) du CO₂ respiré par les feuilles et les racines dans l'obscurité et celle des substrats respiratoires putatifs, y compris les sucres solubles et les acides organiques (malate et citrate), l'activité de la PEPc ainsi que les échanges gazeux des feuilles ont été déterminés sur le haricot (Phaseolus vulgaris L.) et l’épinards (Spinacia oleracea L.) cultivés dans du sable avec différents rapports NH₄⁺: NO₃⁻ dans N fourni. Le CO₂ respiré par les feuilles était enrichi en ¹³C sous NO₃⁻ s’appauvrissant progressivement avec l’augmentation de la fraction de NH₄⁺ dans le N fourni, tandis que la composition isotopique du CO₂ issu de la respiration des racines restait inchangée quel que soit le rapport NH₄⁺: NO₃⁻. Nous avons suggéré qu'une plus grande quantité de pools enrichis en ¹³C fixés par la PEPc via la voie anaplérotique contribuait à la respiration foliaire sous NO₃⁻. Cependant, un effet similaire dans les racines attendu sous NH₄⁺ a été masqué en raison d'une refixation (par la PEPc) du CO₂ respiré (appauvrie en ¹³C). De manière inattendue, les modifications de la composition isotopique du C des métabolites individuels, leurs quantités, ainsi que l'activité de l’enzyme PEPc, présentaient des profils différents entre les deux espèces étudiées. Des expériences de double marquage (¹³C et ¹⁵N) sont nécessaires pour mieux comprendre l’impact de la plasticité métabolique du TCA sur l’écart isotopique entre le malate et le citrate et sur la composition isotopique du CO₂ respiré chez différentes espèces sous différentes formes d’azote. / C-isotope composition of leaf- and root-respired CO₂ in the dark and that of putative respiratory substrates including soluble sugars and organic acids (malate and citrate), PEPc activity, as well as leaf gas exchanges were determined on bean (Phaseolus vulgaris L.) and spinach (Spinacia oleracea L.) plants grown in sand with varying ratios of NH₄⁺: NO₃⁻ in supplied N. Leaf-respired CO₂ was ¹³C enriched under NO₃⁻ nutrition and became progressively ¹³C depleted with increasing amount of NH₄⁺ in supplied N, while C-isotope composition of root-respired CO₂ remained unchanged across N-type gradient. We suggested that a higher amount of ¹³C enriched C-pools fixed by PEPc through anaplerotic pathway contributed to respired CO₂ in leaves under NO₃⁻ nutrition. However, a similar effect in roots expected under NH4+ nutrition was masked because of a rather ¹³C depleted C source (respired CO₂) refixation by PEPc. Unexpectedly, the changes in C-isotope composition of individual metabolites and their amounts as well as PEPc activity exhibited different patterns between the two species. Double labelling experiments (¹³C and ¹⁵N) are needed for better understanding the impact of metabolic plasticity of TCA on isotopic gap between malate and citrate and on C-isotope composition of respired CO₂ in different species under varying N-type nutrition.

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