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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

The design and preparation of pyridoxal 5'-phosphate analogues

Lee, Jasmine January 2002 (has links)
No description available.
2

The biological and chemical estimation of pyridoxine

Conger, Theodore William, January 1941 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1941. / Typescript. Includes abstract and vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 50-53).
3

Chemistry and determination of riboflavin and pyridoxine

Carpenter, Lawrence Edward, January 1943 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 19. / Typescript. Vita. Includes (as Section I): Preparation of samples for microbiological determination of riboflavin / F.M. Strong and L.E. Carpenter. Reprinted from Industrial and engineering chemistry, vol. 14 (15 Nov. 1942), p. 909-913. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
4

Lipogenesis in pyridoxine deficient rats

Song, Gil-Won January 1973 (has links)
The purpose of this study was to evaluate the effect of pyridoxine deficiency on lipogenesis in the rat. It is important in studies of this type to standardize not only the food intake but also the feeding pattern of the experimental and control animals. Pair-feeding of the control rats with the deficient ones imposes on the former animals a feeding pattern similar to meal-feeding. The latter pattern elicits several adaptive changes related to energy utilization by the rat. Therefore, an attempt was made to minimize the difference in the feeding frequency between the deprived and control groups by meal-feeding of the former group. The data were compared with those obtained when only food intake was controlled. Male weanling Wistar rats were used in the present studies. The deprived rats were allowed food either ad libitum (nibbling) or for 2 hours each day (meal-feeding). The appropriate controls were given a complete diet in quantities isocaloric with the consumption of the deprived groups. Decreased fat storage as well as feed efficiency in pyridoxine deficient rats were obvious at that time, regardless of the mode of feeding employed. The fatty acid content of the epididymal adipose tissue was affected in the same manner as body fat. Pyridoxine deprivation also suppressed total body fatty acid synthesis in vivo from glucose-U-¹⁴ C, whether the animals were meal-fed or nibbling. However, the rates of fatty acid synthesis in the epididymal adipose tissue of the meal-fed deprived rats tended to exceed those observed in the control. The lipogenic capacity of liver slices from fed nibbling deprived rats exceeded that of the controls, as evidenced by increased fatty acid labelling in the presence of glucose-U-¹⁴C or acetate-1-¹⁴ C. However, when the nibbling deprived rats were fasted and refed prior to sacrifice, the incorporation of acetate-1-¹⁴ C into fatty acids was lower than in the controls. No differences in the labelling of liver fatty acids and glyceride glycerol were observed when the meal-fed deprived rats were compared with their controls. However, pyridoxine deficiency in meal-fed rats was associated with a decrease in the capacity of the liver to oxidize glucose, as comparison with the controls revealed. Epididymal adipose tissue segments from nibbling deprived rats showed less incorporation of ¹⁴C from labelled glucose into CO₂, fatty acids and glyceride glycerol than those from the corresponding controls (expressed on the basis of the deoxyribonucleic acid content of the tissue). In contrast, increased lipogenic potential of adipose tissue preparation from the deprived meal-fed rats in the presence of insulin was observed. In these rats, a decrease in adipocyte size was suggested by lipid/DNA ratio lower than that of the controls. Thus, the increased lipogenic capacity observed was possibly due to a decrease in adipocyte size, itself associated with increased sensitivity to insulin. The activities of glucose-6-phosphate dehydrogenase and malic enzyme were depressed in both the liver and the adipose tissue of the pyridoxine-deprived rats. Since these enzymes are concerned with the production of the NADPH needed for reductive fatty acid synthesis, the results were consistent with the in vivo finding. However, the activities of these enzymes did not appear to limit the in vitro lipogenic potential of the tissues investigated, since NADPH produced from glucose-6-phosphate dehydrogenase and malic enzyme alone seemed to be sufficient to support the rates of lipogenesis seen. The alterations in lipogenesis in pyridoxine deprivation observed in the present and other investigation could not be explained on the basis of the known functions of the pyridoxine-dependent enzymes. / Land and Food Systems, Faculty of / Graduate
5

Genetic Analysis of Some Unusual Asci From a Cross in Neurospora Crassa

Radford, Alan 09 1900 (has links)
<p> The investigation was carried out in order to determine the nature of some aberrant asci obtained, at a high frequency, from a single cross in Neurospora crassa. The subsequent investigations shed light on an aspect of pyridoxine metabolism and the nature of its genetic control, as well as showing the existence of dicentric chromosome and its great instability when present in the disomic condition. </p> / Thesis / Master of Science (MSc)
6

Effects of vitamin B6 on CC14 toxicities in rats /

Pittaya Kanchanapakonchai, Amnuay Thithapandha, January 1986 (has links) (PDF)
Thesis (M.Sc. (Toxicology))--Mahidol University, 1986.
7

L-Tryptophaan in depressie en strain

Hoes, Melchior Joannes Antonius Josephus Maria, January 1981 (has links)
Thesis (doctoral)--Nijmegen, 1981.
8

Avaliação do papel da piridoxina na prevenção da nefrocalcinose induzida pela hiperoxalúria em ratos / Evaluation of pyridoxine on prevention of nephrocalcinosis in rats induced by hyperoxaluria

Cunha, Natália Baraldi [UNESP] 29 July 2016 (has links)
Submitted by Natália Baraldi Cunha null (nataliabcunha@gmail.com) on 2016-09-07T13:56:55Z No. of bitstreams: 1 Tese final Natália Baraldi Cunha.pdf: 2266420 bytes, checksum: dcf97228e8c74e2d108a5822a0bca60d (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-09-09T20:21:52Z (GMT) No. of bitstreams: 1 cunha_nb_dr_bot.pdf: 2266420 bytes, checksum: dcf97228e8c74e2d108a5822a0bca60d (MD5) / Made available in DSpace on 2016-09-09T20:21:52Z (GMT). No. of bitstreams: 1 cunha_nb_dr_bot.pdf: 2266420 bytes, checksum: dcf97228e8c74e2d108a5822a0bca60d (MD5) Previous issue date: 2016-07-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Introduction: The calcium oxalate is the major metabolic component involved in the formation of renal calculus. Therefore, different pharmacological approaches have been or are being proposed for the treatment of nephrolithiasis by calcium oxalate. Among them, the pyridoxine, a component of vitamin B6, has been suggested as a potential therapeutic agent that can minimize the effects of hyperoxaluria. However, the results are controversial. Objective: To evaluate the effects of pyridoxine (vitamin B6) on the urinary excretion of oxalate and its possible impact on renal disorders caused by nephrocalcinosis induced from an experimental model of hyperoxaluria in rats. Methods: It was used 60 Sprague Dawley male rats and were randomized into four groups: Group 1 [(G1: n = 15) clinical control]; Group 2 [G2: Ethylene glycol (EG) 0.5% + Vitamin D3 (VD3), n = 15], which hyperoxaluria was induced by the administration of EG diluted in water and offered in association with VD3 (Cholecalciferol) at a dose of 0.5 uM; Group 3 [G3: 0.5% EG + VD3 + pyridoxine (VB6); n = 15], which the animals received the same drugs offered to the G2 plus VB6 at a dose of 180mg / kg body weight / day; Group 4 (G4, n = 15) which the animals are supplemented only with the same dose of VB6 in G3. All animals were euthanized after 28 days of intervention and submitted a metabolic study on the urine of 24 hours; histopathological / morphometric analysis of oxidative stress in renal parenchymal and spectroscopic measurement of calcium. Results: Among the urinary parameters evaluated, there was significant reduction in the citrate in G2 compared to the control group- G1 (781.9 and 2414.4mg / L, respectively), while the oxalate was significantly increased in G2 and G3 compared to G1 (7.79, 8.94 and 2.96mg / L, respectively). The urinary calcium was significantly lower in the induced groups (G3: 0.9, G2: 1.5 and G1: 2.25mg / dL). Histomorphometric analysis revealed that only the animals of G2 and G3 developed nephrocalcinosis without, however, no substantially differences from each other in the counting of intratubular crystals were found. Similarly, considering the histopathologic analysis, only the induced animals (G2 and G3) exhibited atrophy, stromal extravasation and inflammatory infiltrate in the renal parenchyma in a similar pattern between the two groups. Regarding to the analysis of oxidative stress, an increase of lipid hydroperoxide levels associated with reduced superoxide dismutase activity and glutathione peroxidase in the G2. In the other groups, the enzyme pattern remained relatively stable compared to the control, except for catalase activity, which activity proved to be increased in all groups. In the other groups, the enzyme pattern remained relatively stable compared to the control (G1), except for the catalase activity, in which activity increased in all groups. As expected, the quantification of calcium in the renal parenchyma was significantly higher in G2 and G3 as compared to groups without induction. Conclusion: Pyridoxine was not able to produce a significant effect in the treatment and / or prevention of urinary disorders, as well as morphological, inflammatory and functional renal tissue in rats with secondary hyperoxaluria obtained from the administration of inducing agents. / Introdução: O oxalato de cálcio (OxCa) é o principal componente metabólico envolvido na formação dos cálculos renais. Por esta razão, diferentes abordagens farmacológicas foram ou estão sendo propostas para o tratamento da nefrolitíase por OxCa. Dentre elas, a piridoxina, um componente da vitamina B6, tem sido sugerida como potencial agente terapêutico capaz de atenuar os efeitos da hiperoxalúria, porém com resultados ainda controversos. Objetivo: Avaliar os efeitos da piridoxina (Vitamina B6) sobre a excreção urinária de oxalato e seu eventual impacto nas alterações renais causadas pela nefrocalcinose induzida a partir de um modelo experimental de hiperoxaluria em ratos. Métodos: Foram utilizados 60 ratos machos da raça Sprague-Dawley, randomicamente distribuídos em quatro grupos: GRUPO 1 (G1: n=15) controle clínico; GRUPO 2 [G2: Etilenoglicol (EG) a 0,5%+vitamina D3 (VD3), n=15] no qual a hiperoxalúria foi induzida a partir da administração de EG diluído em água e ofertado em associação com a VD3 (Colecalciferol) na dose de 0,5 μM; GRUPO 3 [G3: EG 0,5%+VD3+Piridoxina(VB6); n=15] onde os animais receberam as mesmas drogas ofertadas ao G2 acrescido da VB6 na dose de 180mg/kg peso/dia; GRUPO 4 (G4, n=15) animais suplementados apenas com a VB6 na mesma dose do G3. Todos os animais foram eutanasiados após 28 dias de intervenção e submetidos a estudo metabólico na urina de 24 horas; análise histopatológica/morfométrica, análise do estresse oxidativo no parênquima renal, bem como dosagem espectroscópica do cálcio. Resultados: Dentre os parâmetros urinários avaliados, observou-se significativa redução do citrato no G2 em relação ao controle (781,9, e 2414,4mg/L, respectivamente), enquanto que o oxalato mostrou-se significativamente aumentado nos G2 e G3 quando comparado ao G1 (7,79; 8,94 e 2,96mg/L, respectivamente). O cálcio urinário foi significativamente menor nos grupos induzidos (G3:0,9, G2:1,5 e G1: 2,25mg/dL). A análise histomorfométrica revelou que apenas os animais dos G2 e G3 desenvolveram nefrocalcinose sem, no entanto, apresentar diferença significativa entre si na contagem dos cristais intratubulares. Da mesma forma, considerando-se a análise histopatológica, apenas os animais induzidos (G2 e G3) exibiram atrofia, extravasamento estromal e infiltrado inflamatório no parênquima renal, em um padrão bastante semelhante entre os dois grupos. Com relação à análise do estresse oxidativo, houve aumento dos níveis do hidroperoxido de lipídeo associado à redução da atividade da superoxido dismutase e glutationa peroxidase no G2. Nos demais grupos, o padrão enzimático manteve-se relativamente estável em relação ao controle, com exceção da atividade da catalase, cuja atividade revelou-se aumentada em todos os grupos estudados. Como esperado, a quantificação do cálcio no parênquima renal foi significativamente maior em G2 e G3 quando comparado aos grupos sem indução. Conclusão: A piridoxina não foi capaz de produzir um efeito significativo no tratamento e/ou na prevenção das alterações urinárias, bem como morfológicas, inflamatórias e funcionais do parênquima renal de ratos com hiperoxalúria secundária obtida a partir da administração de agentes indutores.
9

Avaliação do papel da piridoxina na prevenção da nefrocalcinose induzida pela hiperoxalúria em ratos

Cunha, Natália Baraldi. January 2016 (has links)
Orientador: Paulo Roberto Kawano / Resumo: Introduction: The calcium oxalate is the major metabolic component involved in the formation of renal calculus. Therefore, different pharmacological approaches have been or are being proposed for the treatment of nephrolithiasis by calcium oxalate. Among them, the pyridoxine, a component of vitamin B6, has been suggested as a potential therapeutic agent that can minimize the effects of hyperoxaluria. However, the results are controversial. Objective: To evaluate the effects of pyridoxine (vitamin B6) on the urinary excretion of oxalate and its possible impact on renal disorders caused by nephrocalcinosis induced from an experimental model of hyperoxaluria in rats. Methods: It was used 60 Sprague Dawley male rats and were randomized into four groups: Group 1 [(G1: n = 15) clinical control]; Group 2 [G2: Ethylene glycol (EG) 0.5% + Vitamin D3 (VD3), n = 15], which hyperoxaluria was induced by the administration of EG diluted in water and offered in association with VD3 (Cholecalciferol) at a dose of 0.5 uM; Group 3 [G3: 0.5% EG + VD3 + pyridoxine (VB6); n = 15], which the animals received the same drugs offered to the G2 plus VB6 at a dose of 180mg / kg body weight / day; Group 4 (G4, n = 15) which the animals are supplemented only with the same dose of VB6 in G3. All animals were euthanized after 28 days of intervention and submitted a metabolic study on the urine of 24 hours; histopathological / morphometric analysis of oxidative stress in renal parenchymal and spectroscopic... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Introdução: O oxalato de cálcio (OxCa) é o principal componente metabólico envolvido na formação dos cálculos renais. Por esta razão, diferentes abordagens farmacológicas foram ou estão sendo propostas para o tratamento da nefrolitíase por OxCa. Dentre elas, a piridoxina, um componente da vitamina B6, tem sido sugerida como potencial agente terapêutico capaz de atenuar os efeitos da hiperoxalúria, porém com resultados ainda controversos. Objetivo: Avaliar os efeitos da piridoxina (Vitamina B6) sobre a excreção urinária de oxalato e seu eventual impacto nas alterações renais causadas pela nefrocalcinose induzida a partir de um modelo experimental de hiperoxaluria em ratos. Métodos: Foram utilizados 60 ratos machos da raça Sprague-Dawley, randomicamente distribuídos em quatro grupos: GRUPO 1 (G1: n=15) controle clínico; GRUPO 2 [G2: Etilenoglicol (EG) a 0,5%+vitamina D3 (VD3), n=15] no qual a hiperoxalúria foi induzida a partir da administração de EG diluído em água e ofertado em associação com a VD3 (Colecalciferol) na dose de 0,5 μM; GRUPO 3 [G3: EG 0,5%+VD3+Piridoxina(VB6); n=15] onde os animais receberam as mesmas drogas ofertadas ao G2 acrescido da VB6 na dose de 180mg/kg peso/dia; GRUPO 4 (G4, n=15) animais suplementados apenas com a VB6 na mesma dose do G3. Todos os animais foram eutanasiados após 28 dias de intervenção e submetidos a estudo metabólico na urina de 24 horas; análise histopatológica/morfométrica, análise do estresse oxidativo no parênquima renal, bem com... (Complete abstract click electronic access below) / Doutor
10

Quantificação das vitaminas do complexo B (B1, B2) e vitâmeros das vitaminas B3 e B6 em amostras de pólen apícola desidratado provenientes da Região Sul do Brasil / Quantification of B complex vitamins (B1, B2) and vitamers of vitamins B3 and B6 in dehydrated bee pollen samples from Southern Brazil

Souza, Bianca Rodrigues de 22 September 2014 (has links)
Entende-se por pólen apícola o resultado da aglutinação do pólen das flores, efetuado pelas abelhas operárias, mediante néctar e substâncias salivares, o qual é recolhido no ingresso da colmeia. A literatura descreve que esse alimento contém proteínas, carboidratos, lipídeos, vitaminas e minerais. De acordo com estudo prévio, amostras de pólen apícola in natura e desidratado, da cidade de Pariquera-Açu (São Paulo), apresentaram teores significativos de vitamina B1(tiamina) e B2 (riboflavina), além da presença dos vitâmeros da vitamina B3 (ácido nicotínico e nicotinamida) e B6 (piridoxal, piridoxol e piridoxamina) em sua composição o que foi associado à flora local explorada pelas abelhas. A região Sul do Brasil possui clima, relevo e vegetação diferenciados de outras regiões, necessitando-se assim da verificação do potencial vitamínico deste produto local. Destaca-se, ainda, o fato de que nesta região encontra-se um dos dois maiores produtores nacionais de pólen apícola (estado de Santa Catarina). O presente trabalho teve como objetivo principal quantificar os teores das vitaminas do complexo B: vitaminas B1 e B2, assim como os vitâmeros das vitaminas B3 e B6. Foram coletados 28 lotes de pólen apícola desidratado de diferentes localidades da região Sul durante o período de agosto de 2011 a dezembro de 2012 que posteriormente foram armazenados, a -18 °C até o momento das análises. As vitaminas do complexo B foram analisadas por cromatografia liquida de alta eficiência (CLAE) na matriz pólen apícola desidratado e os resultados foram expressos em base seca. Entre as amostras analisadas foram verificados teores de vitamina B1 variando entre 0,46 e 1,83 mg / 100 g de pólen apícola; vitamina B2 de 0,40 à 1,86 mg / 100 g e quanto à vitamina B6 apenas os vitâmeros piridoxal e piridoxamina puderam ser quantificados em todos os lotes analisados. O piridoxal teve variação entre as amostras de 0,42 à 6,70 mg / 100 g e a piridoxamina de 0,26 à 0,95 mg / 100g. Em relação à vitamina B3, o vitâmero ácido nicotínico apresentou-se nos diferentes lotes variando de 0,68 à 3,93 mg / 100 g e a nicotinamida de 0,27 à 5,54 mg / 100 g de produto. Tomando-se como porção sugerida para consumo diário 25 g de pólen apícola, verificou-se que num total de 28 amostras, 15 foram consideradas fontes e 2 como ricas em tiamina; 19 lotes foram fontes e 3 ricos em riboflavina, e; 2 lotes foram fontes e 26 ricos em piridoxina segundo à Ingestão Diária Recomendada (IDR) para adultos como disponibilizado na Resolução de Diretoria Colegiada (RDC) nº. 269, de 22 de setembro de 2005. / Bee pollen is understood to be the result of agglutination of pollen from flowers, made by worker bees, and nectar through salivary substances, which is collected at the hive entrance. The literature describes that this product contains proteins, carbohydrates, lipids, vitamins, minerals. Previous study with fresh and dehydrated bee pollen, from the city of Pariquera-Açu (São Paulo) showed significant levels of vitamin B1 (thiamine), B2 (riboflavin), presence of B3 (nicotinic acid and nicotinamide) and B6 (pyridoxal, pyridoxamine, piridoxol) vitamins vitamers in its composition which was associated with the local flora explored by bees. Southern Brazil has a differentiated climate, topography and vegetation from other regions, thus requiring verification of vitamin potential of this local product. Also stands out the fact that this region is one of the two largest national producers of bee pollen (Santa Catarina state). This study aimed to quantify the levels of B complex vitamins: vitamins B1, B2, as well as the vitamers of vitamins B3 and B6. Thus, it was collected 28 batches of dehydrated bee pollen from different locations in the South during the period from August 2011 to December 2012. Samples were obtained and subsequently stored at -18 ° C until the analysis time. B vitamins were analyzed by high performance liquid chromatography (HPLC) in bee pollen dehydrated matrix and results were expressed on a dry basis. Among the samples it levels of vitamin B1 varied from 0.46 to 1.83 mg / 100 g; vitamin B2 from 0.40 to 1.86 mg / 100 g; and for vitamin B6, only the pyridoxal and pyridoxamine vitamers could be quantified in all analyzed batches. The pyridoxal had variation between samples from 0.42 to 6,70 mg / 100 g and pyridoxamine from 0.26 to 0.95 mg / 100g. Taking 25 g of bee pollen as suggested for daily intake portion, it was found in a total of 28 samples that 15 were considered sources and 2 rich in thiamine; 19 lots were sources and 3 rich in riboflavin, and; 2 lots were sources and 26 rich in pyridoxine in relation to the Reference Daily Intake (RDI) for adults as provided in Resolução de Diretoria Colegiada (RDC) nº 269, de setembro de 2005.

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