Orientador: Antonio Olavo Cardoso Jorge / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-07-19T08:44:03Z (GMT). No. of bitstreams: 1 Totti_MarildaAparecidaGoncalves_M.pdf: 2950217 bytes, checksum: 8656561b666ad4485dcb6dafe09fdf85 (MD5) Previous issue date: 1994 / Resumo: A presença de cinco espécies de Candida foi estudada em ratos normais e xerostômicos. Os animais foram inoculados na cavidade bucal durante 4 dias consecutivos com '10 POT.8' células de C. albicans, C. parapsilosis, C. Tropicalis, C. Guilliermondii e C. Krusei. Após 1. 2. 3. 5. 8. 15 e 30 dias da última inoculação, as leveduras foram recuperadas da saliva e quantificadas. C. albicans foi a única espécie recuperada em maior quantidade da boca dos ratos sialoadenectomizados em relação aos normais. C. Tropicalis, C. guilliermondii e C. krusei permaneceram na boca de ratos normais e sialoadenectomizados pelo período de até 5 dias, enquanto a C albicans e C. parapsilosis foram recuperadas em todos os períodos experimentais. Estes resultados confirmam que a xerostomia facilita a instalação, proliferação e persistência de C. albicans na cavidade bucal de ratos, não interferindo, porém, nas outras espécies. Os dados deste estudo sugerem que fatores inerentes às espécies atuam no processo de colonização do fungo na boca de ratos, resultando em diferentes graus de patogenicidade / Abstract: The presence of five Candida species was studied in the mouth of normal and xerostomic rats. The animals were innoculated into the oral cavity with '10 POT.8' cells of Candida albicans, C. Parapsitosis, C. Tropicalis, C. Guilliermondii and C. krusei during 4 consecutive days. The yeasts were recovered from saliva 1. 2. 3. 5. 8. 15 and 30 days after the last innoculation and quantified. C. albicans was the only specie recovered in higher quantity from sialoadenectomized rats, C. Tropicalis, C. Guilliermondii and C. krusei were recovered from the mouth of normal and sialoadenectomized rats up to 5 days after innoculation and C. albicans and C. parapsilosis in all periods. These results confirm that xerostomia facilitate the instalation, proliferation and persistence of C. albicans in the rat's oral cavity, but doesn't interfere with the other species. These differences suggest that factors inherent to the Candida species are relevant for colonization of the mouth of rats, resulting in different degrees of patogenicity / Mestrado / Mestre em Biologia e Patologia Buco-Dental

Orientadores: Jacks Jorge Junior, Ana Lucia Carrinho Ayroza Rangel / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-28T02:10:34Z (GMT). No. of bitstreams: 1 Nobre_JoseaneRodriguesdaSilva_D.pdf: 900740 bytes, checksum: 396aa1db6f094ebb31435e4b1acc479f (MD5) Previous issue date: 2015 / Resumo: A interface prótese-mucosa é o meio ideal para a formação de biofilme e este processo é favorecido pela diminuição do fluxo salivar, por irregularidades da superfície do material e pela temperatura bucal. Os microrganismos presentes no biofilme atuam como uma fonte de infecção e, em situações especiais, podem ser aspirados causando doenças sistêmicas importantes. Candida spp é a levedura mais frequentemente encontrada em próteses totais, sendo relacionada com o desenvolvimento de diversas lesões bucais. O método mais popular para a remoção do biofilme da prótese é a escovação com dentifrício. Recentemente o gel de própolis brasiliensis passou a ser indicado para o controle de microrganismos presentes na cavidade oral. Diante da necessidade de controle da colonização por Candida spp, e como alternativa ao uso de medicações antifúngicas convencionais em pacientes idosos portadores de próteses totais, julgamos oportuno estudar o efeito deste gel na colonização da prótese total destes pacientes. Sendo assim, o objetivo deste estudo foi avaliar o efeito da utilização de dentifrício à base de própolis brasiliensis, comparado a outras técnicas de higienização, quanto a presença de Candida spp na saliva total de pacientes idosos portadores de prótese. Foram selecionados 36 pacientes, randomizados por sorteio e distribuídos em três grupos experimentais: G1 (Grupo CONV) ¿ Os pacientes foram instruídos a realizar higienização mecânica da prótese total superior com escova dental de cabeça média e cerdas macias e dentifrício sem abrasivos, 3 vezes ao dia; G2 (Grupo PROP) - Os pacientes foram instruídos a realizar higienização mecânica da prótese total, com escova dental de cabeça média e cerdas macias e dentifrício à base de própolis Proporalcare® (Pharma Nectar, Belo Horizonte-MG, Brasil), 3 vezes ao dia; G3 (Grupo COTA), pacientes foram orientados a higienizar a prótese total com escova dental de cabeça média e cerdas macias e dentifrício convencional, 3 vezes ao dia, além de imergi-las em solução com pastilhas efervescentes (Corega Tabs®), em recipiente plástico padronizado fornecido pelos pesquisadores. Amostras de saliva não estimulada foram coletadas em T0 (0 dias, consulta inicial); T1 (30 dias de acompanhamento) e T2 (60 dias de acompanhamento), diretamente em frascos estéreis. Alíquotas de 10?L de amostras de saliva puras foram semeadas em placas de Agar-Sabouraud-dextrose. O reconhecimento das colônias foi realizado considerando as características morfológicas da Candida albicans. Os resultados foram submetidos ao teste de normalidade de Shapiro-Wilk, e ao teste não paramétrico de Friedman para amostras emparelhadas, considerando p< 0,05. Após a análise estatística dos resultados foi possível observar que a escovação mecânica utilizando dentifrício convencional ou a base de própolis apresentaram resultados similares nos tempos avaliados, enquanto a utilização de pastilhas efervescentes resultaram em menor número de colônias de Candida spp após 60 dias. Concluímos que a utilização de dentifrício à base de própolis brasiliensis demonstrou resultados similares a utilização do dentifrício convencional e resultados inferiores a utilização associada entre pastilhas efervescentes e dentifrício convencional / Abstract: The denture-mucosa interface is the ideal way to form biofilm and this process is favored by the decrease in salivary flow, irregularities on the surface of the material and oral temperature. The microorganisms in the biofilm act as a source of infection and, in special situations, may be aspirated causing major systemic diseases. Candida spp is the most found yeast in full dentures, being related to the development of several oral lesions. The most popular method to remove biofilm from the denture is brushing with dentrifice. Brasiliensis propolis gel has become an indication for the control of microrganisms in the oral cavity. Faced with the need to control the colonization by Candida spp, and as an alternative to the use of conventional antifungal medications in elderly patients with full dentures, we believe it is appropriate to study the effect of this gel in the colonization of the full dentures of these patients. Thus, the aim of this study was to evaluate the effect of using brasiliensis propolis based dentrifice, compared to other cleaning techniques, as the presence of Candida spp in the saliva total of elderly patients with prosthesis We selected 36 patients, sorted randomly and distributed in three experimental groups: G1 (CONV Group) ¿ The patients were instructed to perform mechanical cleaning of the upper total denture with a toothbrush of medium-size head and soft bristles and dentrifice without abrasives, 3 times a day; G2 (PROP Group) - The patients were instructed to perform mechanical cleaning of the total denture, with a toothbrush of medium-size head and soft bristles and Proporalcare® propolis based dentrifice (Pharma Nectar, Belo Horizonte-MG, Brazil), 3 times a day; G3 (COTA Group) - patients were instructed to perform the cleaning of the total denture with a toothbrush of medium-size head and soft bristles and conventional dentrifice, 3 times a day, and immerse them in solution with effervescent tablets (Corega Tabs®), in a standardized plastic container provided by the researchers. Samples of unstimulated saliva were collected in T0 (0 days, initial consultation); T1 (30-day follow-up) and T2 (60-day follow-up), directly in sterile bottles. 10mL aliquots of pure saliva samples were seeded on Sabouraud-dextrose-Agar plates. The recognition of the colonies was performed considering the morphological characteristics of Candida albicans. The results were submitted to the Shapiro-Wilk normality test, and Friedman nonparametric test for paired samples, considering p< 0.05. After statistical analysis it was possible to observe that the mechanical brushing using conventional dentrifice or propolis based showed similar results in the evaluated times, while the use of effervescent tablets resulted in fewer Candida spp colonies after 60 days. We conclude that the use of brasiliensis propolis based dentrifice showed similar results using conventional dentrifice and inferior results to the ones with combined use of conventional toothpaste and effervescent tablets / Doutorado / Patologia / Doutora em Estomatopatologia

A complete initial velocity study of the 6-phosphogluconate dehydrogenase from Candida utilis in both reaction directions suggests a rapid equilibrium random kinetic mechanism with dead-end E:NADP:(ribulose 5-phosphate) and E:NADPH:(6- phosphogluconate) complexes. Initial velocity studies obtained as a function of pH and using NAD as the dinucleotide substrate for the reaction suggest that the 2'-phosphate is critical for productive binding of the dinucleotide substrate. Primary deuterium isotope effects using 3-<i-6-phosphogluconate were obtained for the 6-phosphogluconate dehydrogenase reaction using NADP and various alternative inucleotide substrates.

No description available.

published_or_final_version / abstract / toc / Dentistry / Doctoral / Doctor of Philosophy

published_or_final_version / Dentistry / Master / Master of Dental Surgery

published_or_final_version / abstract / Dentistry / Doctoral / Doctor of Philosophy

The main objective of this thesis was to study the effects of glucose on the regulation central carbon metabolic functions in the human fungal pathogen Candida albicans (C. albicans). The virulence of C. albicans is dependent upon fitness attributes as well as virulence factors. These attributes include robust stress responses and metabolic flexibility (Brown, 2005). The assimilation of carbon sources is fundamentally important for growth in all organisms and essential for the establishment of infections by pathogens, such as C. albicans in their human host. The C. albicans PCK1 and ICL1 genes, which encode the gluconeogenic and glyoxylate cycle enzymes phosphoenolpyruvate carboxykinase and isocitrate lyase are required for growth on non-fermentable carbon sources such as lactate and oleic acid. This thesis examines the impact of glucose upon the assimilation of secondary carbon sources such as lactate and oleic acid by C. albicans. The addition of 2% glucose repressed the CaPCK1 and CaICL1 genes. However, the enzymes CaIcl1 and CaPck1 were not destabilised by glucose and they retained at high levels following glucose addition. As a result, C. albicans cells continued to assimilate lactate and oleic acid in the presence of glucose. In contrast, the ScPck1 and ScIcl1 proteins were degraded rapidly in S. cerevisiae, and lactate and oleic acid assimilation was repressed in response to glucose. Therefore, while C. albicans and S. cerevisiae display similar responses to glucose at the transcriptional level, their responses at post-transcriptional and metabolic level diverge significantly. As a result, C. albicans can assimilate both glucose and alternative carbon sources at the same time. Next, the molecular apparatus that triggers the destabilisation of target proteins in response to glucose in C. albicans was studied. The expression of C. albicans the ICLI ORF in S. cerevisiae suggested that CaIcl1 has lost the molecular signal that triggers destabilisation in response to glucose, as CaIcl1 was not degraded in response to glucose in S. cerevisiae. However, when ScIcl1 was expressed in C. albicans ScIcl1 was rapidly degraded in response to glucose indicating that C. albicans has retained the molecular apparatus for glucose-accelerated degradation of target proteins. ScIcl1 degradation was slowed in C. albicans ubi4/ubi4 mutants. Furthermore, the addition of a putative of S. cerevisiae ubiquitination site carboxy terminus of CaIcl1 led to glucose-accelerated degradation of this protein in C. albicans cells. Therefore, glucose triggers accelerated degradation of target proteins in C. albicans via a ubiquitin-dependent process.

Candida albicans, a successful human pathogen, displays the phenomenon of glucoseenhanced oxidative stress resistance (Rodaki et al., 2009), which is not observed in other yeast species tested. The molecular bases of the phenomenon are not clear. It was suggested that glucose signalling might play a major role. Therefore, the impact of specific C. albicans mutations was tested to determine which of three known major glucose signalling pathways are required for glucose-enhanced oxidative stress resistance. Two major glucose signalling pathways were found to contribute to the phenomenon (the glucose repression pathway and the cAMP pathway), and a third pathway (the SRR pathway) is not essential for this response. The next step was to identify targets of these pathways that might contribute to the phenotype. First, it was tested whether known oxidative stress systems contribute to the GEXSR. The selected targets represented almost all main systems involved in redox control and ROS detoxification (catalase, superoxide dismutases, thiredoxins, and glutathione peroxidases) which seemed to contribute not significantly to the GEXSR. The exceptions to this were glutathione reductase (Glr1) and glutaredoxin (Grx2/Ttr1), inactivation of which affected manifestation of the phenomenon. This reinforced the view that the GSH/GSSG balance plays a key role in the GEXSR. Second, comparative analyses of transcriptomic profiles of C. albicans glucose- and lactategrown cells in response to oxidative stress and glucose treatment correspondingly revealed a small set of commonly up-regulated genes: UCF1, RNR22, MOH1, orf19.3302, and HSP21/orf19.822 (Enjalbert et al., 2006; Rodaki et al., 2009). Each potential GEXSR-specific gene appeared to be regulated in a distinct manner by the major glucose signalling pathways. The ectopic expression of potential GEXSR targets did not provide any experimental evidence to support their roles in this response. That might be related to inefficient expression from ACT1 promoter under the experimental conditions tested, and also caused by other effects.

Disruption of <i>N-</i>mannosylation and <i>O</i>-mannosylation on the <i>C. albicans</i> outer cell wall increased the rate by which <i>C. albicans</i> is ingested by macrophages. Conversely, disruption of phosphomannosylation reduced the rate of <i>C. albicans</i> is phagocytosis. Alterations to the outer cell wall and genetic or chemical inhibition of hyphal morphogenesis in <i>C. albicans</i> resulted in significantly abrogated macrophage killing <i>in vitro</i>. Disruption of <i>C. albicans </i>ability to tolerate oxidative stresses also perturbed its ability to escape from and kill macrophages. The engagement of specific receptors on the macrophage surface is an essential component of <i>C. albicans</i> recognition and clearance. In the presence of serum, blocking pattern recognition receptors associated with specific fungal cell wall epitopes (Mannose Receptor, Dectin 1 and CD16/32) resulted in an initial decrease in phagocytosis and decreased macrophage killing. Blocking macrophage pattern recognition receptors using soluble components of the<i> C. albicans</i> cell wall resulted in decreased phagocytosis under serum free conditions of <i>O-</i>linked mannans only, and reduced macrophage killing for macrophages pre-exposed to <i>N-</i>mannan and laminarin. The presence of serum increased the rate of uptake for macrophages pre-exposed to <i>N-</i>mannan and laminarin, and had no affect upon macrophage killing. The interaction of <i>C. albicans</i> cell wall epitopes with macrophage pattern recognition receptors, coupled with <i>C. albicans</i> ability to respond to stresses encountered after ingestion are critical determinants of the macrophage’s ability to ingest and process <i>C. albicans.</i>