Les amibes appartenant au genre Acanthamoeba sont ubiquitaires et responsables de diverses infections, en particulier de kératite amibienne. Par ailleurs elles sont résistantes à de nombreux traitements de désinfection, aussi bien sous leur forme libre (trophozoite) que sous leur forme enkystée. La plupart des données d’efficacité disponibles ont évalué des biocides utilisés pour la désinfection de l’eau potable et/ou des lentilles de contact, mais peu de données sont disponibles concernant le traitement des surfaces ou des matériels médicaux. Ces amibes sont également capables de servir de réservoir à des bactéries pathogènes, notamment des nouvelles espèces de Chlamydia regroupées sous le terme « Chlamydia-like ». Il s’agit de bactéries découvertes récemment et potentiellement responsables d’infections respiratoires et d’avortements spontanés. Malgré leur importance, peu de données sont disponibles concernant la survie et la résistance aux biocides de ces bactéries. L’objectif de ce travail a été dans un premier temps d’évaluer la résistance des amibes aux traitements de désinfections, aussi bien pour les trophozoites que pour les kystes. Dans un second temps, nous avons étudié la survie et la résistance des Chlamydia-like à la désinfection, ainsi que leurs interactions avec les amibes et avec différentes lignées cellulaires ; Chlamydia trachomatis a servi de contrôle dans cette deuxième série d’expérimentations. Les méthodes de culture et d’enkystement des trophozoites ainsi que le choix des souches testées se sont avérés critiques pour l’évaluation des biocides. Certains traitements de désinfection généralement réputés efficaces contre la plupart des micro-organismes ont montré une efficacité limitée vis-à-vis des kystes amibiens ainsi que des trophozoites (glutaraldehyde). Les Chlamydia-like se sont avérées capables de survivre dans l’environnement pendant de longues périodes mais sont globalement sensibles aux désinfectants. Certaines de ces bactéries sont également capables de survivre dans les kystes d’amibes, ce qui peut leur conférer une résistance accrue vis-à-vis des biocides. / Acanthamoebae are ubiquitous amoebae responsible for several infections, mostly amoebic keratitis. They are also resistant to numerous disinfection treatments, as well under their free shape (trophozoite ) as under their encysted shape. Most of the available data of efficiency estimated biocides used for the disinfection of the drinking water and\or the contact lenses, but few data are available concerning the treatment of surfaces or medical devices. These amoebae are also capable of serving as reservoir for pathogenic bacteria, in particular for new species of Chlamydia named " Chlamydia-like ". These new bacteria recently discovered are potentially responsible for respiratory infections and miscarriages. Despite their importance, only few data are available concerning the survival and the resistance to biocides. The objective of this work was at first time to evaluate the resistance of amoebae to disinfection treatments, as well for the trophozoites as for the cysts. Secondly, we studied the survival and the resistance of Chlamydia-like to disinfection, as well as their interactions with amoebae and with various cellular lineages; Chlamydia trachomatis served as control in this second series of experiments. The methods of culture and encystement of trophozoites as well as the choice of selected strains turned out critical for the evaluation of biocides. Some treatments generally considered as effective treatments of disinfection against most of the microorganisms showed an efficiency limited towards the amoebic cysts as well as the trophozoites ( glutaraldehyde ). Chlamydia-like turned out capable of surviving in the environment during long periods but are globally sensitive to disinfectants. Some of these bacteria are also capable to surve in amoebal cysts, what can confer them a resistance increased towards biocides.

Objetivos: Avaliar a reprodutibilidade dos critérios de cistos minimamente complexos, diagnosticados pela ultrassonografia, bem como sua história natural e necessidade de estudo complementar. Materiais e métodos: Levantamento dos cistos renais diagnosticados por US no Centro de Ciências da Imagem e Física Médica (CCIFM) da faculdade de Medicina de Ribeirão Preto - Universidade de São Paulo (USP), no período de janeiro de 2003 a julho de 2014, num total de 2.259 casos. Dentre estes, 143 foram descritos como cistos complexos ou minimamente complexos. Após aplicação dos critérios de inclusão e exclusão, 99 cistos foram selecionados para análises das imagens, evolução natural e levantamento de dados clínicos, que foram realizados por dois observadores principais e outros três colaboradores. Resultados: Entre as 99 lesões analisadas, 51 (51,5%) foram consideradas como cistos minimamente complexos e 48 (48,5%) como complexos. A concordância interobservador, avaliada pelo método de Kappa foi de 0.704, com intervalo de confiança de 95% entre 0.517 e 0.892, p< 0.001 (tabela 1). A idade média dos pacientes foi de 59,2 anos, variando de 21 a 93 anos. 40 pacientes eram do gênero masculino (78,4%) e 11 do gênero feminino (21,6%). Dos 51 cistos classificados como minimamente complexos, 11 foram classificados como Bosniak I pela TC/RM, 27 como Bosniak II e 6 como Bosniak 2F. Sete lesões não tiveram correlação com métodos de imagem, porém foram seguidas por pelo menos 3 anos. 25 lesões foram acompanhados por pelo menos 3 anos e nenhuma das lesões apresentou crescimento significativo no período ou mudança em sua arquitetura interna. Conclusão: Os resultados apontam que a avaliação de cistos minimamente complexos, pela US, tem boa reprodutibilidade e a complementação desta avaliação pela tomografia computadorizada ou pela ressonância magnética não é necessária, bastando o seguimento ultrassonográfico, considerando-se a evolução natural destas lesões e a melhor resolução de contraste da US em relação à TC para caracterização dos septos finos. / Objectives: To evaluate the reproducibility of minimally complex cysts criteria, diagnosed by ultrasound as well as its natural history and the need for further study. Methods: Survey of renal cysts diagnosed by US found in Centro de Ciências da Imagem e Física Médica (CCIFM) da Faculdade de Medicina de Ribeirão Preto - Universidade de São Paulo (USP), from January 2003 to July 2014, in a total of 2259 study cases. Among these, 143 cases were described as complex or minimally complex cysts. After applying the inclusion and exclusion criteria, 99 cysts were selected to image analyses, natural history and clinical data, that were performed by two main observers and three cooperators. Results: The mean age of patients was 59.2 years, ranging from 21 to 93 years. 40 patients were male (78.4%) and 11 were females (21.6%). Among the 99 analyzed lesions, 51 (51.5%) were considered as minimally complex cysts and 48 (48.5%) as a complex. The interobserver agreement assessed by the Kappa method was 0.704, with a 95% confidence interval between 0.517 and 0.892, p <0.001 (Table 1). Of the 51 cysts classified as minimally complexes, 11 were classifieds as Bosniak I by CT/ MRI, 27 as Bosniak II and 6 as Bosniak IIF. Seven cysts were not correlated with crosssectional methods, however were followed for at least 3 years. Twenty-five lesions were followed for at least three years and none of the injuries showed significant growth or internal architecture changes. Conclusion: Our results show that the evaluation of minimally complex cysts, by US, showed good reproducibility and the completion of this evaluation by CT scan or MRI is not required, since a follow up using ultrasound is safe, in view of the low malignancy rate of these lesions and US better contrast resolution compared to CT for thin septa (hair-like) characterization.

O tumor odontogênico queratocístico é um tumor odontogênico benigno recentemente classificado como tal pela Organização Mundial de Saúde. O alto índice de recidiva, a similaridade com outras lesões odontogênicas císticas e mutações genéticas associadas, estimulam continuamente estudos com finalidade de aprimorar o diagnóstico e o entendimento do comportamento desta lesão. As citoqueratinas, principal componente do citoesqueleto epitelial, têm sido utilizadas como possíveis marcadores no diagnóstico do tumor odontogênico queratocístico, apesar da discrepância dos resultados publicados. O gene PTCH1, com mutação já relatada associada ao tumor odontogênico queratocístico, expressa proteína de mesmo nome que parece estar associada com a etiologia ou com o prognóstico do tumor odontogênico queratocístico. Vinte casos de tumor odontogênico queratocístico foram submetidos à técnica de imunoistoquímica para detecção da expressão das citoqueratinas 10, 13, 17 e 19 e da proteína PTCH1. Cada caso foi representado por dois momentos distintos da mesma lesão, sendo metade dos casos representados por lesões sem história de recidiva e a outra metade constituída de casos com história de recidiva. A marcação obtida em cada um dos momentos foi comparada, verificando assim a estabilidade de expressão. A influência da inflamação na expressão imunoistoquímica também foi avaliada. As citoqueratinas 10 e 17 se mostraram com maior porcentagem de positividade (82, 5% e 97,5%, respectivamente) e com maior estabilidade entre os momentos (65% e 95%, respectivamente). A proteína PTCH1 foi positiva em todos os momentos, apresentando assim estabilidade total para os casos estudados. Não houve diferença estatisticamente significante, para nenhum dos anticorpos utilizados, entre os grupos sem ou com história de recidiva ou de expressão nas áreas de inflamação. A estabilidade das citoqueratinas 10 e 17 sugere que estas possam ser utilizadas associadamente como auxiliar de diagnóstico do tumor odontogênico queratocístico. A proteína PTCH1 demonstrou alta positividade e estabilidade; porém não pôde ser relacionado ao comportamento do tumor odontogênico queratocístico. / The keratocystic odontogenic tumor is a benign odontogenic tumor recently classified as such by the World Health Organization. The high recurrence rate, the similarity with other odontogenic cystic lesions and the genetic associated mutations continuous stimulate studies intending diagnostic enhancement and behavior understanding of such lesion. The citokeratins, main component of the epithelial cytoskeleton, have been used as possible diagnostic markers of the keratocystic odontogenic tumor, in spite the discrepancy of the published results. The PTCH1 gene, with already reported mutation associated with the keratocystic odontogenic tumor, expresses a protein with the same name that seems to be associated with the etiology or the prognosis of the keratocystic odontogenic tumor. Twenty cases of keratocystic odontogenic tumor were submitted to the immunohistochemical technique for detection of the expression of citokeratins 10, 13, 17 and 19 and the protein PTCH1. Each case was represented by two distinct moments of the same lesion, being half of the cases represented by lesion without recurrence history and the other half constituted of lesion with recurrence history. The obtained staining in each moment was compared, thus verifying the expression stability. The influence of inflammation in the immunohistochemical expression was also evaluated. The cytokeratins 10 and 17 demonstrated higher positivity percentage (82.5% and 97.5%, respectively) and greater stability among the moments (65% and 97.5%, respectively). The PTCH1 protein was positive in all moments, thus presenting total stability for the studied cases. There was no statistical difference, for none of the antibodies, either among the groups without or with history of recurrence or in the expression in areas with inflammation. The stability of the cytokeratins 10 and 17 suggests that they can be used together as auxiliary for the diagnosis of the keratocystic odontogenic tumor. The protein PTCH1 demonstrated high positivity and stability; however it could not be related to the behavior of the keratocystic odontogenic tumor.

To study the ecology of organic-walled dinoflagellate cysts, the changes in species composition, diversity, and seasonal variations of cyst flux in the sediment trap deployed in the Strait of Georgia (BC, Canada) were examined. The cyst production rate varied from ~600 to 336,200 cysts m-2 day-1, with an average of 20,000 cysts m-2 day-1. Throughout the study period (March, 1996 - January, 1999), cyst assemblages were mostly dominated by cysts produced by heterotrophic dinoflagellates, such as Protoperidineaceae (Brigantedinium spp., Quinquequspis concreta, and cysts of Protoperidinium americanum). Cysts produced by heterotrophic dinoflagellates peaked in June each year, whereas cysts produced by autotrophic taxa were most abundant during August-September. The total annual dinoflagellate cyst flux was higher in 1996 than in 1997 and 1998, being enhanced by the bloom of Alexandrium spp. The warmer sea-surface temperature in 1998 had a positive effect on the production of both autotrophic and heterotrophic dinoflagellates, as inferred from the cyst fluxes.

Thesis--København Tandlægehøjskole. / Summary in Danish. Bibliography: p. 179-194.

Thesis--København Tandlægehøjskole. / Summary in Danish. Bibliography: p. 179-194.

Thesis (Dr. rer. nat.)--Universität Tübingen, 2004. / Includes bibliographical references. Available in PDF format via the World Wide Web.

No description available.

O objetivo desse estudo foi avaliar as características do tecido conjuntivo de 11 folículos pericoronários, 12 cistos dentígeros e de 14 tumores odontogênicos ceratocísticos (TOCs). A amostra foi submetida às técnicas de Hematoxilina e Eosina, Tricrômico de Masson, Picrosírius, Direct Blue e Orceína. Tricrômico de Masson foi utilizado para avaliação de diferenças de densidade e de paralelismo das fibras colágenas, bem como presença de infiltrado linfoplasmocitário. Picrosírius serviu para mensuração da quantidade de fibras colágenas; Direct Blue e Orceína, para identificação do sistema de fibras elásticas. Lâminas coradas por essas três últimas técnicas foram visualizadas em microscopia confocal a laser. Os resultados mostraram semelhança entre o folículo pericoronário e o TOC: paralelismo de fibras colágenas arranjadas em um padrão eminentemente denso, podendo conter uma camada de densidade frouxa junto ao tecido epitelial. As cápsulas de cistos dentígeros eram compostas por fibras colágenas desorganizadas, ou não paralelas, em um arranjo frouxo com presença de infiltrado linfoplasmocitário. Não foi observada marcação para fibras do sistema elástico. Com base nos resultados, conclui-se que a cápsula do TOC representa o estroma da lesão, desempenhando função de suporte e que, diferentemente, o tecido conjuntivo do cisto dentígero é parte da resposta inflamatória. / The aim of this study was to evaluate the connective tissue features of pericoronal follicles, dentigerous cysts and keratocystic odontogenic tumor. The sample was submitted to Hematoxylin-eosin, Masson Trichrome, Picrosirius, Direct Blue and Orcein stains. Masson Trichrome was performed to distinguish collagen fibers density and parallelism, as well as chronic infiltrate presence. Picrosirius was performed to collagen fibers quantification; Direct Blue and Orcein, to elastic system fibers identification. Picrosirius, Direct Blue and Orcein staining slides were observed by means confocal laser scanning microscope. Results showed similar features between pericoronal follicle and keratocystic odontogenic tumor: parallel collagen fibers, more tightly packed collagen fibers, and sometimes a soft layer beneath epithelial tissue. Dentigerous cyst capsule was composed by wound collagen fibers, soft packed, associated to chronic inflammatory infiltrate. It was not observed elastic system fibers labeling. Based on results, it was concluded that keratocystic odontogenic tumor capsule represent the lesion stroma, playing a support role. This finding is different from dentigerous cyst where connective tissue is produced by inflammatory response.

This study contributes to developing terrestrial and marine palynological indicators of winter or summer monsoon signals as well as oceanographic environments of the South China Sea (SCS). The high-resolution reconstructions of Holocene East Asian Monsoon (EAM) climate and oceanographic condition of the northern SCS provide insights into regional climate events in the western low-latitude Pacific Ocean and their impacts on local oceanography and ecology. Sediment trap samples from the southwest Taiwan waters of the SCS in winter monsoon (March-April) and summer monsoon (July-August) seasons identify abundances of Pinus and Ulmus pollen as indicators of the winter monsoon whereas fern spores appeared to be indicators of the summer monsoon. The increased fluxes of dinoflagellate cyst (DC) taxa during summer are correlated with decreased sea-surface salinity (SSS) associated with nutrient-rich river inputs. DC distributions across the SCS show that some taxa are good indicators of changes in sea-surface temperature (SST), SSS, water depth and chlorophyll-a (chl-a) concentrations associated with EAM and oceanographic conditions. In particular, the concenrations of Brigantedinium spp. and cysts of Protoperidinium together with Echinidinium spp. are positively correlatd with SST in January and SST in July, and chl-a concentrations, respectively, which are linked to past monsoon strength and primary productivity. In total, four high cyst concentration regions have been observed off southern Vietnam, Borneo, Hainan, and South China. High-resolution palynological records from a sediment core in the northern SCS reflect several EAM climatic and oceanographic events over the last 12.5 kyr. A short-term Impagidinium decrease implied that the Taiwan Strait opened at ~11.7–11.0 cal kyr BP, with reduced Kuroshio Current influence when the East China Sea waters entered through the strait. Three Holocene relative sea-level stages were identified in the palynomorph records. The highest herb pollen abundances were observed before ~10.4 cal kyr BP, reflecting the shortest distance from the grassland sources on the exposed shelf at the low sea-level stand. High Brigantedinium and cysts of Protoperidinium abundances also indicate a near-shore environment. During ~10.4- ~6.8-6.0 cal kyr BP at the rising sea-level stage, fern spore abundances increased and DC abundances decreased. Consistently low total DC concentrations and high fern spore abundance were observed after ~6.8-6.0 cal kyr BP when the present oceanographic conditions were formed. Increased abundances of Pinus pollen reflected three strengthened winter monsoon intervals at ~5.5, 4.0 and 2.5 cal kyr BP under the present oceanographic conditions. The highest Dapsilidinium pastielsii abundances reflected the warmest interval at ~6.8-5.5 cal kyr BP of the northern SCS. / Graduate / 2019-12-13