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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.
101

Stock and Species Identification of Selected Marine Fishes and Shellfishes Using Allozyme Analysis and Isoelectric Focusing: Implications for Texas Fisheries Management

King, Timothy L. (Timothy Lee) 05 1900 (has links)
Allozyme frequencies and general protein patterns were surveyed among selected Texas marine fishes and shellfishes to illustrate the application of biochemical genetic techniques to stock and species identification in fisheries management.
102

Toxicological and Biochemical Investigations of Alpha-Chaconine in Potato (Solanum Tuberosum L. ) Tubers: Physiologic Disposition and Tissue Binding, and Inhibition of Tissue Cholinesterases and Isoenzymes

Alozie, Sydney Obodoechina 01 May 1977 (has links)
The distribution, absorption, metabolism and tissue binding of radioactivity were studied in hamsters after oral and intraperitoneal administration of alpha-chaconine- (3H). The material was well absorbed from the gastrointestinal tract and nearly 22 percent of the label was excreted via urine and feces in 7 days. The excretion was higher in urine (21 percent) than in feces ( < 1 percent). Tissue concentrations of radioactivity peaked at 12 hours following oral administration, with the highest concentrations found in lungs, liver, spleen, skeletal muscle, kidney and pancreas, with heart and brain containing moderate amounts. Concentrations of radioactivity in tissues following intraperitoneal administration were significantly higher than those observed after oral treatment. Excretion of chloroform-soluble products in the feces was 10 times higher than that of the chloroform-insoluble metabolites after both oral and intraperitoneal administration. In the urine, the activity was predominantly in the chloroform-insoluble form and the chloroform-soluble metabolites were relatively minor in amounts (0.27, 0.85, and 2.45 percent versus 0.005, 0.14 and 0.19 percent of dose for 12, 24 and 72 hours, respectively). After 7 days, the chloroform-soluble metabolites in urine increased to 20 percent of the excreted radioactivity, while the amount of chloroform-insoluble metabolites was less than 1 percent. Subcellular distribution of the labeled compound indicated the highest concentration of radioactivity in the nuclear and microsomal fractions of brain, liver and heart tissues. A small amount of radioactivity, shown by a minor peak, was also observed in the fractions between the mitochondrial and microsomal fractions on a sucrose gradient. Binding of radioactivity was observed in brain, testes, kidney, lung, liver and heart . All of the label in the brain appeared to be in the bound form . The results indicated that alpha-chaconine is slowly absorbed from the gastrointestinal tract after oral administration, and persists in various tissues, much of it in bound (non-extractable) form (in nuclear and microsomal fractions). Excretion of alpha-chaconine- (3H) and its metabolites was investigated after oral and intraperitoneal administration in hamsters. The separation of the glycoalkaloid and its metabolites in feces and urine was accomplished by thin-layer chromatography. An increase in the concentration of excreted alpha-chaconine metabolites in feces and urine was observed. In urine over 50 percent of the eliminated radioactivity during the initial 24 hours was due to the aglycone, solanidine. The fraction of the total dose administered which was excreted represented only 27 percent (26 percent in feces and less than 1 percent in urine) during the 7 day test period. Contrary to the general belief that potato glycoalkaloid absorption is poor following oral administration, only 5 percent or less was excreted in feces during the initial 72 hours, a fact explained by the binding of radioactivity to tissues. Inhibition of acetylcholinesterases by alpha-chaconine was studied. The inhibition of purified erythrocyte acetylcholinesterase and horse serum cholinesterase by alpha-chaconine was found to be a mixed-type with kinetic constants. An inhibition constant (Ki) for both the specific and pseudocholinesterases was 8.3 x 10-6 M and 4.0 x 10-4 M, respectively. Kinetic constants obtained for both enzymes were as follows: Vmax of 7.14 x 10-5 and 3.76 x 10-4 max moles/liter/min, respectively, and Km of 6.2 x 10-5 and 1.33 x 10-4, respectively. The distribution of acetylcholinesterase among the subcellular fractions of rat brain homogenate separated by sucrose density gradient centrifugation was determined, as well as the inhibition pattern of these fractions following in vitro incubation with 0.016 M alpha-chaconine. Enzyme activity was found to be distributed equally between the mitochondrial and microsomal fractions, with the nuclear fraction having the least activity. Percentage inhibition of the various fractions obtained was: whole homogenate 43, nuclear fraction 55, mitochondria 35, and microsomes 33. Brain acetyl cholinesterase activity of animals given intraperitoneal doses (10, 30, 60 mg / Kg) of alpha-chaconine was 79, 55 and 18 percent of the control group. Acetylcholinesterase activity of heart and plasma of animals administered alpha-chaconine did not show the dose-related response observed in the brain. Inhibition of heart acetylcholinesterase was 61 percent, while plasma gave 51 percent for the rats given a dose of 10 mg/Kg and no inhibition for rats given 30 mg/ Kg. Acrylamide gel electrophoretic separation of cholinesterases in aqueous homogenates from whole brain and heart of adult male rats administered alpha-chaconine was investigated. Brain acetylcholinesterase isoenzymes were found to be inhibited by 30 and 60 mg/ Kg dosage levels of alpha-chaconine administered intraperitoneally. Electrophoretic separation of plasma from the treated animals resulted in five anodally migrating zones having properties of cholinesterases. These sites hydrolyze acetylthiocholine and alpha-naphthylacetate, and all were inhibited by alpha-chaconine except the slowest migrating band (band 5). Inhibition of isoenzyme activity of bands 1 and 2 is observed for the groups administered 10 and 30 mg/Kg alpha-chaconine with the percentage inhibition of both bands (l and 2) being 40 and 77 percent for animals given 10 mg/Kg and 100 and 75 percent for the latter group. Isoenzyme bands 3 and 4 were completely absent in the alkaloid treated animals. Inhibition of non-specific cholinesterase isoenzymes (butyrylthiocholine hydrolyzable bands) by alpha-chaconine was clearly demonstrated. In vitro inhibition of plasma, erythrocyte and brain esterase isoenzymes was estimated by incubating gels with 10-4 M alpha-chaconine after the electrophoretic separations. With this concentration of alpha-chaconine, the various isoenzymes in rat plasma, erythrocyte and brain showed some response to the inhibitory potency of alpha-chaconine. The slower-moving isoenzyme bands were inhibited to 100 percent with the different concentrations of inhibitor. The fast migrating isoenzyme bands in plasma and erythrocytes were least affected by alpha-chaconine (10-4 M), with no inhibition. Plasma protein isoenzymes from adult male rats were not affected by alphachaconine.
103

Lactic dehydrogenase isozyme isolation by disc electrophoresis in eight species of fringillid birds

Darling, Michael Edwin 01 January 1971 (has links)
Disc electrophoresis of tissue homogenates from eight species of fringillid birds showed five forms of lactic dehydrogenase. The relative amounts of isozymes were characteristic for each species. This paper classifies some members of the families Fringillidae and Carduelidae in terms of lactic dehydrogenase isozymes and compares the results to other methods of classification.
104

Aldehyde dehydrogenases in cancer: an opportunity for biomarker and drug development?

Pors, Klaus, Moreb, J.S. 12 1900 (has links)
No / Aldehyde dehydrogenases (ALDHs) belong to a superfamily of 19 isozymes that are known to participate in many physiologically important biosynthetic processes including detoxification of specific endogenous and exogenous aldehyde substrates. The high expression levels of an emerging number of ALDHs in various cancer tissues suggest that these enzymes have pivotal roles in cancer cell survival and progression. Mapping out the heterogeneity of tumours and their cancer stem cell (CSC) component will be key to successful design of strategies involving therapeutics that are targeted against specific ALDH isozymes. This review summarises recent progress in ALDH-focused cancer research and discovery of small-molecule-based inhibitors.
105

Localisation immunohistochimique de l’enzyme 5α-réductase type 1 et 3 dans la peau et la prostate de chiens beagle en santé.

Bernardi de Souza, Lucilene 07 1900 (has links)
No description available.
106

Thermal Selection at an Enzyme Locus in Populations of the Red Shiner, Notropis lutrensis, Receiving Hypolimnion Effluents from a Reservoir

Richmond, M. Carol 05 1900 (has links)
Genetic variation was examined at 19 loci encoding enzymatic and general proteins Notropis lutrensis from the Brazos River in Texas. The thermal regime of the Brazos River below Possum Kingdom Reservoir is altered due to the release of water from the hypolimnion. Summer water temperatures fluctuate as much as 7^oC. Levels of heterozygosity at the malate dehydrogenase-2 locus were correlated with the degree of water temperature fluctuation at each locality. The isozymes from three homozygous patterns of supernatant malate dehydrogenase (Mdh-l, Mdh-2) exhibited different activities at different experimental temperatures.
107

Atributos de qualidade em sementes de trigo recobertas com zinco durante e após armazenamento / Attributes of quality seeds of wheat zinc coated during and after storage

Tunes, Lilian Vanussa Madruga de 21 November 2011 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Seed coating treatments are among the most interesting and potentially beneficial for enhancing the performance of the same. This fact, which helps the producer to improve the performance and development of seedlings, with the possibility the use of micronutrients such as zinc, in the seeds. Our objectives were to evaluate the effect of wheat seed coating with zinc through the physiological, sanitary and enzyme quality, during storage and analyze the effect of this nutrient, on nutrition early growth of seedlings and on the components of income after storage. Were tested for levels 0, 1, 2, 3 and 4 mL ZnSO4.kg-1 seed, high and low quality, for the seed quality physiological, sanitary and enzyme, six months of storage. After the storage period, we assessed the dry mass, zinc content and accumulation in shoots and roots of wheat plants. We also evaluate the efficiency of absorption, transport and use of zinc in addition to verification of the yield components. We conclude that the ZnSO4 assists in maximum expression of seed quality. There are variations in the pattern of expression of the enzymes EST, GOT and GTDH. The micronutrient zinc, associated with fungicide and polymer, showed a lower incidence of fungi during the storage period. The application of ZnSO4 in seeds causes a higher dry matter and zinc content in the roots. Zinc applied to wheat seeds accumulate mainly in roots. The application of ZnSO4 in seeds resulting in higher absorption efficiency and lower transport efficiency and use of Zn, as we increase the doses of the nutrient. Considering the results of the yield components, number of grains per spikelet and grain weight per plant, it can be said that the wheat seed coating with zinc provides a productivity increase of more than 30%. / O recobrimento de sementes está entre os tratamentos mais interessantes e potencialmente benéficos para realçar o desempenho das mesmas. Fato esse, que contribui ao produtor melhorar o desempenho e desenvolvimento das plântulas, com possibilidade da utilização de micronutrientes como o zinco, nas sementes. Os objetivos deste trabalho foram avaliar o efeito do recobrimento de sementes de trigo com zinco, através da qualidade fisiológica, enzimática e sanitária durante o armazenamento e, analisar o efeito desse micronutriente sobre a nutrição e o crescimento inicial das plântulas e sobre os componentes de rendimento após armazenagem. Foram testados níveis de 0; 1; 2; 3 e 4 mL de ZnSO4.kg-1 de semente, de maior e menor qualidade, para a qualidade fisiológica, enzimática e sanitária das sementes durante seis meses de armazenamento. Após o período de armazenamento, foram avaliados a massa seca, teor e acúmulo de zinco na parte aérea e raiz de plantas de trigo. Foram analisadas também, a eficiência de absorção, transporte e utilização de zinco, além da verificação dos componentes de rendimento. Conclui-se que o ZnSO4 auxilia na máxima expressão da qualidade das sementes. Há variações no padrão de expressão das enzimas EST, GOT e GTDH. O micronutriente zinco, associado com fungicida e polímero, apresentou menor incidência de fungos ao longo do período de armazenamento. A aplicação de ZnSO4 nas sementes, ocasiona uma maior massa seca e teor de zinco nas raízes. O zinco aplicado às sementes de trigo acumula-se principalmente nas raízes. A aplicação de ZnSO4 em sementes, resultou em maior eficiência de absorção e menor eficiência de transporte e utilização de Zn, à medida que aumentam as doses do nutriente. Considerando os resultados dos componentes de rendimento, número de grãos por espigueta e peso de grãos por planta, pode-se dizer que o recobrimento das sementes de trigo com zinco propicia um aumento de produtividade superior a 30%.
108

SMAD3 in embryonic patterning, mesoderm induction, and colorectal cancer in the mouse

Wieduwilt, Matthew J. January 2003 (has links) (PDF)
Thesis (Ph. D.) -- University of Texas Southwestern Medical Center at Dallas, 2003. / Vita. Bibliography: 180-208.
109

Estudos de algumas populações brasileiras de Lutzomyia (Nyssomyia) whitmani s.l. (Diptera: Psychodidae: Phlebotominae), importante transmissor de agentes da leishmaniose tegumentar americana / Studies of some Brazilian populations of Lutzomyia (Nyssomyia) whitmani s.l. (Diptera: Psychodidae: Phlebotominae), important transmitter of agents of American cutaneous leishmaniasis

Costa, Simone Miranda da 29 July 2005 (has links)
Made available in DSpace on 2015-03-26T13:30:46Z (GMT). No. of bitstreams: 1 texto completo.pdf: 598225 bytes, checksum: b52ee586ca1555dc273c3952237b3272 (MD5) Previous issue date: 2005-07-29 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Lutzomyia (Nyssomyia) whitmani s.l. (Antunes & Coutinho 1939) has a large distribution in Brazil, being registered in all geographic regions. In American continent this specie was found in French Guyana, Paraguay, Peru and Argentina. In Brazil it s incriminated as a vector of Leishmania (Viannia) braziliensis and Leishmania (Viannia) shawi. Considering the large geographic distribution, the different aspects of biology and the possibility of Leishmania spp. transmission, the objective of the present study was to increase the knowledge about Lutzomyia (N.) whitmani s.l., an important vector of American Cutaneous Leishmaniasis (ACL) in Brazil, determining its geographic distribution in association with epidemiologic circuits of LTA, as well as to evaluate the vectorial competence, the genetic variability and the structure level of some L. (N.) whitmani s.l. Brazilian population. Two maps were created which enabled one to visualize the distribution of. L. (N.) whitmani s.l in the different Brazilian municipalities in association with the different types of vegetation and active transmission of ACL. L. (N.) whitmani s.l. was registered in 720 Brazilian municipalities, been verified in 26 federal units, hadn t been registered only, in state of Santa Catarina, inhabiting different kinds of vegetation and associated with different climates. The discussion about L. (N.) whitmani s.l. representing a species complex is based on aspects of its biology and vetorial competence, that reveal its capacity in transmit two distinct parasites and has different habits living in diversified habitats. The isoenzymatic analysis indicated that the L. (N.) whitmani s.l. populations of the study areas (Paragominas, Santarém, Londrina and Ilhéus) represent only one species with great chances of suffer subdivisions due to the course of evolution. We observed that the population of Paragominas municipality was detached from others by presenting the biggest genetic differentiation, which contributed for the formation of an isolated bunch in the grouping analysis. In an epidemiologic macro-territorial view, independent of being transmitting Leishmania (Viannia) braziliensis and Leishmania (Viannia) shawi, L. (N.) whitmani s.l. can be suggested as the most important vector of American Cutaneous Leishmaniasis in Brazil. / Lutzomyia (Nyssomyia) whitmani s.l. (Antunes & Coutinho, 1939) possui uma ampla distribuição no território brasileiro, sendo registrada em todas as regiões geográficas e, no Continente Americano, a espécie foi assinalada na Guiana Francesa, no Paraguai, no Peru e na Argentina. No Brasil está incriminada como vetora de Leishmania (Viannia) braziliensis e Leishmania (Viannia) shawi. Considerando a vasta distribuição geográfica, aspectos diferenciados da biologia e, a possível veiculação de duas leishmânias dermotrópicas, o objetivo do trabalho foi ampliar os conhecimentos sobre Lutzomyia (N.) whitmani s.l., importante transmissor de Leishmaniose Tegumentar Americana (LTA) no Brasil, determinando a distribuição espacial deste flebotomíneo associada aos circuitos epidemiológicos de LTA, bem como avaliar a competência vetorial, a variabilidade e o grau de estruturação genética de algumas populações brasileiras. Foram elaborados dois mapas temáticos que, por sobreposição, permitiram visualizar o registro de L. (N.) whitmani s.l em municípios associados aos circuitos epidemiológicos da LTA e aos diferentes tipos de vegetação. L. (N.) whitmani s.l foi registrada em 720 municípios brasileiros, de vinte e seis unidades federadas, não tendo registro, apenas, em Santa Catarina, habitando diferentes tipos de vegetação e associados a variados climas. A discussão sobre L. (N.) whitmani s.l. representar um complexo de espécies está baseada em aspectos da sua biologia e da competência vetorial, que revelam sua capacidade em transmitir duas leishmânias distintas e ter hábitos diferenciados com a ocupação de diferentes ecótopos. Através da análise de isoenzimas, foi sugerido que as populações de L. (N.) whitmani s.l. das áreas estudadas (Paragominas, Santarém, Londrina e Ilhéus) representariam uma única espécie, com grandes chances de sofrer subdivisões em decorrência da evolução. Observou-se que a população do Município de Paragominas se destacou das demais por apresentar uma maior diferenciação genética, o que contribuiu para a formação de um ramo isolado na análise de agrupamentos. Numa visão epidemiológica macro-territorial, independente de estar transmitindo Leishmania (Viannia) braziliensis ou Leishmania (Viannia) shawi, sugere-se L. (N.) whitmani s.l. como o mais importante transmissor da Leishmnaiose Tegumentar Americana no Brasil.
110

Pré-hidratação de sementes de ervilha e sua interferência na avaliação do potencial fisiológico / Pea seed pre hydration and its interference with the evaluation of the physiological potential

Costa, Caroline Jácome 22 February 2007 (has links)
Made available in DSpace on 2014-08-20T13:44:37Z (GMT). No. of bitstreams: 1 tese_caroline_costa.pdf: 410037 bytes, checksum: 70221bc02297589fd9d80d107be7a2aa (MD5) Previous issue date: 2007-02-22 / The present work had the objective of to study biochemical and physiological alterations in function of pea seed pre hydration with e phasis in the electrolyte leakage and in the expression of different isoenzymatic systems,trying to contribute for the i provement of the pre hydration methods of seeds to be submitted to tests for evaluation of its physiological potential.Seeds lots of cvs.Axé and Maria, characterized for the water content,germination,first ger mination counting,accelerated aging,electrical conductivity and seedling emergence in the field,were used.The seeds of each lot were pre hydrated in saturated atmosphere and hum idified substratu until they reach 10,12 and 14%of water content.After the pre hydration,the seeds were submitted to the tests of electrical conductivity,accelerated aging and leakage of calcium ,potassium and magnesium and characterized for the expression pattern of the isoenzymatic systems Malate Dehydrogenase,Acid Phosphatase,Glutamate Dehydrogenase and Glutamate Oxalacetate Transaminase.The pre hydration of the seeds using saturated atmosphere or humidified substratum see s to affect the process of restructuring the seed cellular e branes system differently,being reflected in alterations in the pattern of electrolyte leakage and Acid Phosphatase isoenzymatic expression.Discrepancies take place a ong results obtained by the test of electrical conductivity for evaluation of the physiological potential of pea seeds,depending on the proceeding adopted to pre hydrate the seeds. / O presente trabalho teve o objetivo de estudar alterações bioquímicas e fisiológicas decorrentes da pré hidratação de sementes de ervilha,com ênfase na lixiviação de eletrólitos e na expressão de diferentes sistemas isoenzim áticos,procurando contribuir para o aperfeiçoamento dos métodos de pré hidratação de sementes a serem submetidas a testes para avaliação do seu potencial fisiológico.Foram utilizados lotes de sementes de ervilha das cultivares Axé e Maria,caracterizados quanto ao teor de água,germinação, primeira contagem de germinação,envelhecimento acelerado,condutividade elétrica e emergência de plântulas e campo.As sementes de cada lote fora pré hidratadas e pregando atmosfera saturada e substrato umedecido,até atingirem teores de água de 10, 12 e 14%.Após a pré hidratação,as sementes foram avaliadas pelos testes de condutividade elétrica,envelhecimento acelerado,lixiviação de cálcio,potássio e magnésio e caracterizadas quanto ao padrão de expressão dos sistemas isoenzimáticos Malato Desidrogenase,Fosfatase Ácida,Glutamato Desidrogenase e Glutamato Oxalacetato Transaminase.A pré hidratação de sementes de ervilha e pregando atmosfera saturada ou substrato umedecido afeta diferentemente o processo de reestruturação do sistema de e branas celulares das sem entes,refletindo se e alterações no padrão de lixiviação de eletrólitos e na expressão do sistema isoezimático Fosfatase Ácida.Ocorre discrepâncias entre resultados obtidos pelo teste de condutividade elétrica para avaliação do potencial fisiológico de sementes de ervilha,dependendo do procedim ento adotado para a pré hidratação das sementes.

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