La Quinolinate synthase (NadA) catalyse la condensation de l'iminoaspartate et de la dihydroxyacétone phosphate aboutissant à la formation d'acide quinolinique, un intermédiaire central dans la biosynthèse du nicotinamide adénine dinucléotide (NAD). Cette étude a permis de montrer que toutes les quinolinate synthases possèdent un centre [4Fe-4S] essentiel à l'activité et que seulement 3 résidus cystéines coordinent le centre métallique, les cystéines Cys113, Cys200 et Cys297 chez E. coli. Les propriétés spectroscopiques et biochimiques du centre [4Fe-4S] nous ont conduit à proposer que le centre fer-soufre joue un rôle de type aconitase/déshydratase dans la catalyse enzymatique. Deux autres cystéines impliquées dans la formation d'un pont disulfure, sont également essentielles à l'activité quinolinate synthase (Cys291 et Cys294 chez E. coli) en jouant probablement un rôle régulateur. Nous rapportons également une nouvelle hypothèse de mécanisme pour la formation de l'acide quinolinique, incluant l'isomérisation du glycéraldéhyde 3-phosphate en DHAP. Enfin, nous proposons NadA comme une cible potentielle d'agents antibactériens. Sur les différentes molécules testées in vitro, l'acide phosphoglycolohydroxamique (PGH) s'est avérée actif sur la quinolinate synthase d'E. coli et de M. tuberculosis, en agissant comme un inhibiteur compétitif du DHAP.

Diferentes estratégias têm sido propostas a fim de melhorar o desempenho dos bioeletrodos utilizados nas biocélulas a combustíveis e nos biossensores. Por examplo, a funcionalização de eletrodos de carbono tem sido feita para esse fim. Neste estudo, propomos o desenvolvimento de fibras flexíveis de carbono (FFCs) funcionalizadas com grupos quinona e modificados com álcool desidrogenase (ADH) NAD-dependente para obter bioeletrodos para uma bio-eletrocatálise eficiente de etanol. Grupos quinona na superfície das FFCs foram obtidas utilizando o tratamento oxidativo com permanganato e também pelo ancoramento eletroquímico de antraquinona: ambas metodologias resultaram em bioeletrodos para a eletro-oxidação de NADH que pode aumentar a bio-eletrocatálise do etanol. De acordo dados espectroscópicos, microscópicos, e eletroquímicos, defeitos contendo grupos C=O nos eletrodos de FFCs são atribuídos à melhora na oxidação do NADH, aumentando a bio-eletrocatálise do etanol. Para se investigar o papel dos grupos quinona na eletro-oxidação do NADH, propomos uma configuração experimental baseado na espectroscopia de ressonância paramagnética de elétrons em modo operando (operando EPR). Com essa técnica, fomos capaz de mostrar a correlação entre o número de elétrons livres desemparelhados, a concentração superficial de quinonas e a oxidação do NADH com controle eletroquímico. Correlação para a concentração de spins revela um aumento no número de elétrons desemparelhados livres com o aumento do sobrepotencial aplicado e a oxidação do NADH, o que corrabora com a hipótese de que grupos quinona podem afetar a eletrocatálise rumo à oxidação do NADH a NAD+. É vislumbrado que operando EPR pode fornecer infromação útil para provar a dinâmica da transferência de elétrons em superfície de carbono e possa ser extendida a outros sistemas bioeletroquímicos. / There are several strategies to improve the performance of bioelectrodes applied in biosensors and biofuel cells. For instance, surface functionalization of the carbon-based electrodes has been used to this intend. Herein, we propose the development of flexible carbon fibers (FCFs) functionalized with quinone groups and modified with NAD-dependent alcohol dehydrogenase (ADH) to obtain bioelectrodes for efficient ethanol bio-electrocatalysis. Quinones groups on FCFs surfaces were obtained by using oxidative treatment with permanganate, and also by electrochemical grafting of anthraquinone: both these methodologies result in bioelectrodes for the electro-oxidation of NADH that can improve the ethanol bio-electrocatalysis. Based on spectroscopic, microscopic and electrochemical data, defects containing C=O groups on FCFs electrodes are attributed to improve the NADH oxidation, enhancing the ethanol bio-electrocatalysis. In order to investigate the role of quinone groups on the NADH electro-oxidation, we propose an experimental setup based on operando electron paramagnetic resonance spectroscopy (operando EPR). With this technique, we are able to show a correlation among the number of free unpaired electrons, surface concentration of quinones and NADH oxidation under electrochemical control. Correlation for the spin concentration reveals an increasing number of free unpaired electrons with increasing applied overpotential and NADH oxidation, which corroborates the hypothesis that quinone groups can act as electrocatalysts towards the oxidation of NADH to NAD+. It is glimpsed that operando EPR can provide useful information in probing the electron transfer dynamics on a carbon surface and may be extended to others bioelectrochemical systems.

Accelerated Adaptation through Stimulated Copy Number Variation in Saccharomyces cerevisiae Ryan Matthew Hull Repetitive regions of the genome, such as the centromeres, telomeres and ribosomal DNA account for a large proportion of the genetic variation between individuals. Differences in the number of repeat sequences between individuals is termed copy number variation (CNV) and is rife across eukaryotic genomes. CNV is of clinical importance as it has been implicated in many human disorders, in particularly cancers where is has been associated with tumour growth and drug resistance. The copper-resistance gene CUP1 in Saccharomyces cerevisiae is one such CNV gene. CUP1 is transcribed from a copper inducible promoter and encodes a protein involved in copper detoxification. In this work I show that yeast can regulate their repeat levels of the CUP1 gene through a transcriptionally stimulated CNV mechanism, as a direct adaptation response to a hostile environment. I characterise the requirement of the epigenetic mark Histone H3 Lysine 56 acetylation (H3K56ac) for stimulated CNV and its limitation of only working at actively transcribed genes. Based upon my findings, I propose a model for how stimulated CNV is regulated in yeast and show how we can pharmacologically manipulate this mechanism using drugs, like nicotinamide and rapamycin, to stimulate and repress a cell's ability to adapt to its environment. I further show that the model is not limited to high-copy CUP1 repeat arrays, but is also applicable to low-copy systems. Finally, I show that the model extends to other genetic loci in response to different challenging environments, such as formaldehyde stimulation of the formaldehyde-resistance gene SFA1. To the best of our knowledge, this is the first example of any eukaryotic cell undergoing genome optimisation as a novel means to accelerate its adaptation in direct response to its environment. If conserved in higher eukaryotes, such a mechanism could have major implications in how we consider and treat disorders associated with changes in CNV.

No description available.

No description available.

Orientador: Hélio Amante Miot / Resumo: O tratamento do campo de cancerização tem o intuito de evitar a progressão das lesões pré-malignas ou desenvolvimento de lesões subclínicas, como forma de prevenção da carcinogênese. Existem diversas propostas de tratamento, porém, há poucos estudos com nicotinamida oral, nenhum comparando a eficácia entre 5-fluorouracil (5FU) tópico com fotoproteção, ou na sua associação com a nicotinamida oral. Objetivos: Avaliação da eficácia da nicotinamida oral, versus 5FU tópico intermitente, e fotoproteção, no tratamento do campo de cancerização cutâneo e queratoses actínicas (QA). Casuística e métodos: Desenho: ensaio clínico randomizado (em blocos), controlado (intrasujeito), duplo cego, fatorial. Participantes: pacientes imunocompetentes, que continham entre três e dez QA cada antebraço, selecionados durante os atendimentos do ambulatório oncológico do serviço de dermatologia da Faculdade de Medicina de Botucatu – UNESP no período de março a setembro de 2016. Houve randomização em blocos e alocação em grupos dos pacientes e antebraços. Intervenção: um grupo recebeu nicotinamida 500mg, via oral, cada 12h, e o outro, placebo. Um dos antebraços recebeu 5FU 5% creme, noturno, 3x por semana, e ambos, filtro solar (FPS 30) diurno. A duração dos tratamentos foi de 120 dias. Os pacientes foram avaliados nos momentos: T0 e T120 para avaliação clínica (contagem de QA, escore de gravidade de QA e escore de fotoenvelhecimento) e biópsia de pele para avaliação do grau de neoplasia intraepitelial... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Background: The treatment of the skin field cancerization is aimed at preventing the progression of premalignant lesions or the development of subclinical lesions as a way of preventing carcinogenesis. There are several treatment proposals, however, there are few studies with oral nicotinamide, none comparing the efficacy of topical 5-fluorouracil (5FU) with photoprotection, or its association with oral nicotinamide. Objectives: To evaluate the efficacy of oral nicotinamide versus intermittent topical 5FU and photoprotection in the treatment of cutaneous cancer and actinic keratoses (AK). Casuistry and methods: Design: randomized (blocks), controlled (intrasubject), double blind, factorial clinical trial. Participants: immunocompetent patients, who had between 3 and 10 AK each forearm, selected during the visits of the oncology outpatient clinic of the dermatology department of Botucatu Medical School - UNESP from March to September, 2016. There was randomization in blocks and allocation in Groups of patients and forearms. Intervention: one group received nicotinamide 500mg, orally every 12h, and the other, placebo. One of the forearms received 5FU 5% cream, overnight, 3x per week, and both, daytime (SPF 30) sunscreen. The duration of the treatments was 120 days. The patients were evaluated at the moments: T0 and T120 for clinical evaluation (AK score, AK severity score and photoaging score) and skin biopsy for evaluation of the levels of keratinocyte intraepithelial neoplasi... (Complete abstract click electronic access below) / Mestre

Submitted by Eliane Roio Ferreira null (eliane_roio@yahoo.com.br) on 2018-07-22T17:04:37Z No. of bitstreams: 1 Dissertacao Eliane 31-07-2017 (Salvo Automaticamente) repositorio.pdf: 1376384 bytes, checksum: fe63f38c9413fbb73b267ecfae5dfb34 (MD5) / Approved for entry into archive by Sulamita Selma C Colnago null (sulamita@btu.unesp.br) on 2018-07-23T13:30:44Z (GMT) No. of bitstreams: 1 ferreira_er_me_bot.pdf: 1376384 bytes, checksum: fe63f38c9413fbb73b267ecfae5dfb34 (MD5) / Made available in DSpace on 2018-07-23T13:30:45Z (GMT). No. of bitstreams: 1 ferreira_er_me_bot.pdf: 1376384 bytes, checksum: fe63f38c9413fbb73b267ecfae5dfb34 (MD5) Previous issue date: 2017-08-24 / O tratamento do campo de cancerização tem o intuito de evitar a progressão das lesões pré-malignas ou desenvolvimento de lesões subclínicas, como forma de prevenção da carcinogênese. Existem diversas propostas de tratamento, porém, há poucos estudos com nicotinamida oral, nenhum comparando a eficácia entre 5-fluorouracil (5FU) tópico com fotoproteção, ou na sua associação com a nicotinamida oral. Objetivos: Avaliação da eficácia da nicotinamida oral, versus 5FU tópico intermitente, e fotoproteção, no tratamento do campo de cancerização cutâneo e queratoses actínicas (QA). Casuística e métodos: Desenho: ensaio clínico randomizado (em blocos), controlado (intrasujeito), duplo cego, fatorial. Participantes: pacientes imunocompetentes, que continham entre três e dez QA cada antebraço, selecionados durante os atendimentos do ambulatório oncológico do serviço de dermatologia da Faculdade de Medicina de Botucatu – UNESP no período de março a setembro de 2016. Houve randomização em blocos e alocação em grupos dos pacientes e antebraços. Intervenção: um grupo recebeu nicotinamida 500mg, via oral, cada 12h, e o outro, placebo. Um dos antebraços recebeu 5FU 5% creme, noturno, 3x por semana, e ambos, filtro solar (FPS 30) diurno. A duração dos tratamentos foi de 120 dias. Os pacientes foram avaliados nos momentos: T0 e T120 para avaliação clínica (contagem de QA, escore de gravidade de QA e escore de fotoenvelhecimento) e biópsia de pele para avaliação do grau de neoplasia intraepitelial dos queratinótitos (KIN), p53 e ki67. Foram avaliados ainda os efeitos adversos no T14. Desfechos: foram analisados por intenção de tratamento (ITT), e os dropouts imputados com os valores da última avaliação disponíveis (LOCF). Os grupos foram comparados por modelo linear generalizado de efeitos mistos. Resultados: Foram incluídos 36 participantes (72 antebraços). A média de idade foi 71,6 (8,6) anos, fototipos I e II prevaleceram (94%) e 61% eram do sexo feminino. Houve redução na contagem de QA para nicotinamida com 5FU (-71%) e com filtro solar (-50%), assim como para placebo e 5FU (-62%) e filtro solar (-60%), 5FU apresentou superioridade ao FPS (p<0,05). O clearance parcial de QA (>50%), apresentou redução para todos os subgrupos (-83%; -50%; -72%; -61%), com superioridade para 5FU (p<0,05). O clearance total de QA não apresentou diferença entre os tratamentos (p=0,72,). Houve redução do escore de gravidade de QA (-74%; -62%; -81%; -64%) e de fotoenvelhecimento (-10%; -6%; -22%; -8%), sem diferença entre os grupos (p>0,2). Os principais efeitos adversos observados foram eritema (50%) e dor local (5%) com uso de 5-FU, epigastralgia e náusea com nicotinamida (5%). Houve redução no escore KIN em todos os grupos (p<0,05), sem diferença entre os subgrupos. Houve redução da atrofia epitelial em todos os tratamentos (p<0,05), com superioridade para 5FU (p<0,05). Houve redução do escore Ki67 em ambos os tratamentos (p<0,05), com maior redução no grupo que recebeu nicotinamida (p<0,05). Para p53 não houve diferença entre os tratamentos (p=0,81). Ocorreram 3 dropouts. Conclusão: 5-FU tópico reduz a atividade do campo de cancerização de forma mais eficaz que o filtro solar quanto à contagem e ao clearance de QA. Nicotinamida oral não promoveu melhora clínica, mas histológica (Ki67), adicional à fotoproteção ou ao uso de 5FU. / Background: The treatment of the skin field cancerization is aimed at preventing the progression of premalignant lesions or the development of subclinical lesions as a way of preventing carcinogenesis. There are several treatment proposals, however, there are few studies with oral nicotinamide, none comparing the efficacy of topical 5-fluorouracil (5FU) with photoprotection, or its association with oral nicotinamide. Objectives: To evaluate the efficacy of oral nicotinamide versus intermittent topical 5FU and photoprotection in the treatment of cutaneous cancer and actinic keratoses (AK). Casuistry and methods: Design: randomized (blocks), controlled (intrasubject), double blind, factorial clinical trial. Participants: immunocompetent patients, who had between 3 and 10 AK each forearm, selected during the visits of the oncology outpatient clinic of the dermatology department of Botucatu Medical School - UNESP from March to September, 2016. There was randomization in blocks and allocation in Groups of patients and forearms. Intervention: one group received nicotinamide 500mg, orally every 12h, and the other, placebo. One of the forearms received 5FU 5% cream, overnight, 3x per week, and both, daytime (SPF 30) sunscreen. The duration of the treatments was 120 days. The patients were evaluated at the moments: T0 and T120 for clinical evaluation (AK score, AK severity score and photoaging score) and skin biopsy for evaluation of the levels of keratinocyte intraepithelial neoplasia (KIN), p53 and ki67. Adverse effects were also evaluated in the T14. Outcomes: were analyzed by intention to treat (ITT), and the imputed dropouts with the values of the last observation carried forward (LOCF). The groups were compared by generalized linear model of mixed effects. Results: 36 participants (72 forearms) were included. The mean age was 71.6 (8.6) years, phototypes I and II prevailed (94%) and 61% were female. There was a reduction in the counts of AK for nicotinamide with 5FU (-71%) and with sunscreen (-50%), as well as for placebo and 5FU (-62%) and sunscreen (-60%), 5FU presented SPF superiority (P <0.05). The partial clearance of AK (> 50%) presented a reduction for all subgroups (-83%, -50%, -72%, -61%), with a superiority of 5FU (p <0.05). Total clearance of AK did not show any difference between the treatments (p = 0.72,). There was a reduction in the severity score of AK (-74%, -62%, -81%, -64%) and of photoaging (-10%, -6%, -22%, -8%), with no difference between Groups (p> 0.2). The main adverse effects observed were erythema (50%) and local pain (5%) with use of 5-FU, epigastralgia and nausea with nicotinamide (5%). There was a reduction in the KIN score in all groups (p <0.05), with no difference between the subgroups. There was reduction of epithelial atrophy in all treatments (p <0.05), with superiority to 5FU (p <0.05). There was a reduction in the Ki67 score in both treatments (p <0.05), with a larger reduction in the nicotinamide group (p <0.05). For p53 there was no difference between treatments (p = 0.81). There were 3 dropouts: one per death, one refusal because the lesions improved, and one drop due to adverse local effects. Conclusion: Topical 5-FU reduces the activity of the cancerization field more effectively than the sunscreen in the counting and clearance of AK. Oral nicotinamide did not promote clinical improvement, but histological improvement (Ki67), additional to photoprotection or the use of 5FU.

Nucleoside 5'-Diphosphate Kinase (NdPK EC 2.7.4.6) is an enzyme (phosphotransferase) with extraordinary characteristics due to its unique ability to transfer phosphor groups to interconvert all nucleoside di- and triphosphates as a part of the DNA synthesis. Due to Biovica International AB's use of signaling and complementing enzymes in their in vitro diagnostic (IVD) test assays for Thymidine Kinase activity, an investigation was proposed to evaluate NdPK, which is a complementing enzyme in the assay. The aim of the study was to evaluate the enzymatic turnover of the enzyme NdPK with a spectrophotometric assay to obtain the specific activity (Units/mg solid protein). To determine the specific activity, enzyme kinetic methodology was applied, including the Michaelis-Menten model. In this study, the method is proposed as a general internal control procedure for the company, as a tool for function control of the different purchased enzymes used in their products in development. Results from the study reflects the different methods used to gain the specific activity for NdPK, where they were compared with the already specified specific activity from the manufacturing company. The results were auspicious, but before the method's authorization as an internal quality procedure, a few amendments are in mind. For instance, determining a method for the graphical readings, validating the method for quality control, and investigating if the method is applicable to other complementing enzymes. In conclusion, the method for determining the specific activity of the enzyme NdPK can be done, by executing the procedure of colorimetric enzyme assay.

Curcumin is the major phenolic diarylheptane derivative in Curcuma longa and has been reported to possess pharmacological activities. Unfortunately this compound suffers from poor bioavailability and rapid neutral-alkaline degradation. Co-crystal of curcumin is one option under exploration, motivated by the fact that a number of active pharmaceutical ingredient (API) co-crystals with improved dissolution have recently been synthesized. Hence, co-crystallization technique highlights an alternative means to improve the performance of curcumin. Within our work evidences for a co-crystal was ascertained from DSC, Kofler hot stage screening and PXRD, and all confirmed a new crystal phase could have been formed between curcumin and a co-crystallizing agent, nicotinamide. We report that re-crystallization step essentially aids the purification of commercial curcumin, a herbal based actives. Otherwise the prevalence of a new crystal phase in solvent-mediated co-crystallization will be significantly reduced. Besides, phase diagram is an effective tool for the study of solubility behaviours in co-crystal system. In order to acquire related techniques, fenbufen, a poorly water soluble drug, was selected. The result showed the huge difference in solubility between fenbufen and nicotinamide lead to difficulty in the construction of phase diagram.

Crystal Engineering is the design of crystalline material using non-covalent synthesis. Co-crystals are multi-component crystals which are constructed from complementary intermolecular interactions, they are also known as supramolecular complexes. Design of such materials utilises the synthon approach, this involves the understanding of common intermolecular interactions which occur in the crystal packing and is used to design new solids with desired physical properties and chemical properties. Primary amides form supramolecular heterosynthons, these synthons represent an opportunity for a design of multi-component crystals in which one molecule contains a primary amide and a second molecule which is complimentary to the primary amide, usually carboxylic acids. The progress with regards to the screening process for the determination of co-crystals is evident in the literature, In particular, high throughput solution growth methods and solvent drop grinding. The comparison of Isonicotinamide and Benzamide as a co-crystal component has been presented. This study was motivated by the observation that the CSD contains 24 Isonicotinamide and 1 Benzamide co-crystal. The interaction with carboxylic acids is the focus of the work, in particular those which form Isonicotinamide co-crystal are being screened with Benzamide. Our work utilises a ReactArray Microvate to carry out the low throughput solution growth on a matrix of carboxylic acid with Benzamide, this study has been coupled with the Kofler hot stage microscope method which visually aids to screen and view co-crystal phase formation. Crystallisation screens have resulted in the identification of known co-crystal phases of Isonicotinamide and Benzamide, additionally new co-crystal phases have also been identified with Fumaric, 3-hydroxybenzoic acid, Mandelic Acid, 4-Nitrobenzoic Acid and Tartaric Acid. Single crystal structures of the Fumaric and 4-Nitrobenzoic acid have been obtained. In order to develop an understanding of co-crystal formation in Isonicotinamide and Benzamide with our supramolecular library, packing landscape analysis is being undertaken using both the CSD and crystal structures we have obtained. This is undertaken as collaboration with Dr Andy Parkin and Professor Gilmore (University of Glasgow), we have identified that the dSNAP analysis is a way forward for the analysis of how co-crystals pack. The analysis highlighted the subtleties that were present in the packing motifs of the Isonicotinamide co-crystals. In particular the cis and trans orientation of the amide and acid carbonyl to each other and the planar and off planar layer assemblies. All of which are required to maximise the hydrogen bond usage of the components comprising the co-crystals. Further investigations have led to the collaborative project with Syngenta Ltd in the design of a co-crystal screen using a high through-put robot, Crissy® -Automation Platform by Zinsser Analytical, using an extended screen of 16 acid coformers with Isonicotinamide, Benzamide and Nicotinamide the sample have been characterised using a reflectance diffraction method, GADDS. Further analysis of this data involves the use of polySNAP, which has led to further collaboration with Professor Gilmore¿s group. / Syngenta