Étude de l'expression de l'ARNm de l'interleukine-17 dans les lavages broncho-alvéolaires des chevaux atteints du souffle

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Functional educational characterisation of the utility of embalming fluids for anatomical education and research

Human cadavers have long been used to teach human anatomy and are increasingly used in other disciplines. Different embalming techniques have been reported in the literature; however there is no clear consensus on the opinion of anatomists on the utility of embalmed cadavers for the teaching of anatomy. To this end, we aimed to survey British and Irish anatomy teachers to report their opinions on different preservation methods for the teaching of anatomy. In this project eight human cadavers were embalmed using formalin, Genelyn, Thiel and Imperial College London- Soft Preserving (ICL-SP) techniques to compare different characteristics of these four techniques. The results of this thesis show that anatomy teachers consider hard-fixed cadavers not to be the most accurate teaching model in comparison to the human body, although it still serves as a useful teaching method (Chapter 2). In addition, our findings confirm that joints of cadavers embalmed using ICL-SP solution faithfully mimics joints of an unembalmed cadaver compared to the other techniques (Chapter 3). Embalming a human body prevents the deterioration in the quality of images and our findings highlight that the influence of the embalming solutions varied with the radiological modality used (Chapter 4). The method developed as part of this thesis enables anatomists and forensic scientists to quantify the decomposition rate of an embalmed human cadaver (Chapter 5). Formalin embalming solution showed the strongest antimicrobial abilities followed by Thiel, Genelyn and finally by ICL-SP (Chapter 6). The overarching viewpoint of this set of studies show that it is inaccurate to state that one embalming technique is ultimately the best. The value of each technique differs based on the requirement of the particular education or research area. Hence we highlight how different embalming techniques may be better suited to certain fields of study.

Étude de l'expression de l'ARNm de l'interleukine-17 dans les lavages broncho-alvéolaires des chevaux atteints du souffle

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Geochemical composition of calcite and aragonite, and characteristics of hydrothermal fluids of ODP Leg 168 sites

During Leg 168 a transect was drilled across the eastern flank of the Juan de Fuca Ridge in an area where the volcanic basement is covered by sediments of variable thickness. Samples of basement volcanic rocks were recovered from nine locations along the transect, where the basement sediment interface is presently heated to temperatures varying from 15° to 64°C. Altered rocks with secondary calcium carbonate were common at four of the sites, where present-day temperatures range from 38° to 64°C. Fluid inclusions in aragonite suggest that the mineral precipitated from an aqueous fluid of seawater salinity at temperatures well below 100°C. The chemical compositions of secondary calcite and aragonite were determined with both an electron microprobe and a laser-ablation inductively coupled plasma-mass spectroscopy (LA-ICP-MS) microprobe. These two techniques yielded consistent analyses of the same minor elements (Mg and Sr) in the same specimens. The combined results show that secondary aragonites contain very little Mg, Mn, Fe, Co, Ni, Cu, Zn, Rb, La, Ce, Pb, or U, yet they contain significant Sr. In contrast, secondary calcites contain significant Mg, Mn, Fe, Ni, Cu, Zn, and Pb, yet very little Co, Rb, Sr, La, Ce, or U. Secondary calcium carbonates provide subseafloor reservoirs for some minor and trace elements. Replacement of aragonite by calcite should result in a release of Sr, Rb, and Zn to solution, and it provides a sink for Mg, Mn, Ni, Cu, Zn, and Pb.

(Table 3) Geochemistry of borehole fluids of ODP Hole 137-504B

Circulation of seawater through basaltic basement for several million years after crustal emplacement has been inferred from studies of surface heat flow, and may play a significant role in the exchange of elements between the oceanic crust and seawater. Without direct observation of the fluid chemistry, interpretations regarding the extent and timing of this exchange must be based on the integrated signal of alteration found in sampled basalts. Much interest has thus been expressed in obtaining and analyzing fluids directly from basaltic formations. It has been proposed that open oceanic boreholes can be used as oceanic groundwater wells to obtain fluids that are circulating within the formation. Water samples were collected from the open borehole in Hole 504B prior to drilling operations on Leg 137, with the original intention of collecting formation fluids from the surrounding basaltic rocks. Past results have yielded ambiguous conclusions as to the origin of the fluids recovered-specifically, whether or not the fluids were true formation fluids or merely the result of reaction of seawater in the borehole environment. The chemistry of eight borehole fluid samples collected during Leg 137 is discussed in this paper. Large changes in major, minor, and isotopic compositions relative to unaltered seawater were observed in the borehole fluids. Compositional changes increased with depth in the borehole. The samples exhibit the effect of simple mixing of seawater, throughout the borehole, with a single reacted fluid component. Analysis and interpretation of the results from Leg 137 in light of past results suggest that the chemical signals observed may originate predominantly from reaction with basaltic rubble residing at the bottom of the hole during the interim between drilling legs. Although this endeavor apparently did not recover formation waters, information on the nature of reaction between seawater and basalt at the prevalent temperatures in Hole 504B (>160°C) has been gained that can be related to reconstruction of the alteration history of the oceanic crust. Isotopic analyses allow calculation of element-specific water/rock mass ratios (Li and Sr) and are related to the extent of chemical exchange between the borehole fluids and basalt.

(Table 1) Chemical and isotopic composition of pore fluids in cores TGC-1 and TGC-6

The role of sediment diagenesis in the marine cycles of Li and B is poorly understood. Because Li and B are easily mobilized during burial and are consumed in authigenic clay mineral formation, their abundance in marine pore waters varies considerably. Exchange with the overlying ocean through diffusive fluxes should thus be common. Nevertheless, only a minor Li sink associated with the low-temperature alteration of volcanic ash has been observed. We describe a low-temperature diagenetic environment in the Black Sea dominated by the alteration of detrital plagioclase feldspars. Fluids expelled from the Odessa mud volcano in the Sorokin Trough originate from shallow (~100-400 m deep) sediments which are poor in volcanic materials but rich in anorthite. These fluids are depleted in Na+, K+, Li+, B, and 18O and enriched in Ca2+ and Sr2+, indicating that anorthite is dissolving and authigenic clays are forming. Using a simple chemical model, we calculate the pH and the partial pressure of CO2 (PCO2) in fluids associated with this alteration process. Our results show that the pH of these fluids is up to 1.5 pH units lower than in most deep marine sediments and that PCO2 levels are up to several hundred times higher than in the atmosphere. These conditions are similar to those which favor the weathering of silicate minerals in subaerial soil environments. We propose that in Black Sea sediments enhanced organic matter preservation favors CO2 production through methanogenesis and results in a low pore water pH, compared to most deep sea sediments. As a result, silicate mineral weathering, which is a sluggish process in most marine diagenetic environments, proceeds rapidly in Black Sea sediments. There is a potential for organic matter-rich continental shelf environments to host this type of diagenesis. Should such environments be widespread, this new Li and B sink could help balance the marine Li and Li isotope budgets but would imply an apparent imbalance in the B cycle.

Seawater carbonate chemistry and conditions of Mytilus edulis extracellular body fluids and shell composition in a pH-treatment experiment: Acid-base status, trace elements and delta11B, 2012

Mytilus edulis were cultured for 3 months under six different seawater pCO2 levels ranging from 380 to 4000 µatm. Specimen were taken from Kiel Fjord (Western Baltic Sea, Germany) which is a habitat with high and variable seawater pCO2 and related shifts in carbonate system speciation (e.g., low pH and low CaCO3 saturation state). Hemolymph (HL) and extrapallial fluid (EPF) samples were analyzed for pH and total dissolved inorganic carbon (CT) to calculate pCO2 and [HCO3]. A second experiment was conducted for 2 months with three different pCO2 levels (380, 1400 and 4000 µatm). Boron isotopes (delta11B) were investigated by LA-MC-ICP-MS (Laser Ablation-Multicollector-Inductively Coupled Plasma-Mass Spectrometry) in shell portions precipitated during experimental treatment time. Additionally, elemental ratios (B/Ca, Mg/Ca and Sr/Ca) in the EPF of specimen from the second experiment were measured via ICP-OES (Inductively Coupled Plasma-Optical Emission Spectrometry). Extracellular pH was not significantly different in HL and EPF but systematically lower than ambient water pH. This is due to high extracellular pCO2 values, a prerequisite for metabolic CO2 excretion. No accumulation of extracellular [HCO3] was measured. Elemental ratios (B/Ca, Mg/Ca and Sr/Ca) in the EPF increased slightly with pH which is in accordance with increasing growth and calcification rates at higher seawater pH values. Boron isotope ratios were highly variable between different individuals but also within single shells. This corresponds to a high individual variability in fluid B/Ca ratios and may be due to high boron concentrations in the organic parts of the shell. The mean delta11B value shows no trend with pH but appears to represent internal pH (EPF) rather than ambient water pH.

Fiber-optic vibration sensing of cantilevers immersed in fluids

An all fiber-optical method to monitor densities and viscosities of liquids utilizing a steel cantilever (4 x 0.3 x 0.08 cm3) is presented. The actuation is performed by photothermally heating the cantilever at its base with an intensity-modulated 808 nm diode laser. The cantilever vibrations are picked up by an in-fiber Fabry Perot cavity sensor attached along the length of the cantilever. The fluid properties can be related to the resonance characteristics of the cantilever, e.g. a shift in the resonance frequency corresponds to a change in fluid density, and the width of the resonance peak gives information on the dynamic viscosity after calibration of the system. Aqueous glycerol, sucrose and ethanol samples in the range of 0.79–1.32 gcm−3 (density) and 0.89–702 mPas (viscosity) were used to investigate the limits of the sensor. A good agreement with literature values could be found with an average deviation of around 10 % for the dynamic viscosities, and 5–16 % for the mass densities. A variety of clear and opaque commercial spirits and an unknown viscous sample, e.g. home-made maple syrup, were analyzed and compared to literature values. The unique detection mechanism allows for the characterization of opaque samples and is superior to conventional microcantilever sensors. The method is expected to be beneficial in various industrial sectors such as quality control of food samples.

The comparative utility of fluorescence in situ hybridization and reverse transcription-polymerase chain reaction in the diagnosis of alveolar rhabdomyosarcoma.

Fluorescence in situ hybridization (FISH) for FOXO1 gene rearrangement and reverse transcription-polymerase chain reaction (PCR) for PAX3/7-FOXO1 fusion transcripts have become routine ancillary tools for the diagnosis of alveolar rhabdomyosarcomas (ARMS). Here we summarize our experience of these adjunct diagnostic modalities at a tertiary center, presenting the largest comparative series of FISH and PCR for suspected or possible ARMS to date. All suspected or possible ARMS tested by FISH or PCR for FOXO1 rearrangement or PAX3/7-FOXO1 fusion transcripts over a 7-year period were included. FISH and PCR results were correlated with clinical and histologic findings. One hundred samples from 95 patients had FISH and/or PCR performed. FISH had higher rates of technical success (96.8 %) compared with PCR (88 %). Where both tests were utilized successfully, there was high concordance rate between them (94.9 %). In 24 histologic ARMS tested for FISH or PCR, 83.3 % were translocation-positive (all for PAX3-FOXO1 by PCR) and included 3 histologic solid variants. In 76 cases where ARMS was excluded, there were 3 potential false-positive cases with FISH but none with PCR. PCR had similar sensitivity (85.7 %) and better specificity (100 %) in aiding the diagnosis of ARMS, compared with FISH (85 and 95.8 %, respectively). All solid variant ARMS harbored FOXO1 gene rearrangements and PAX3-FOXO1 ARMS were detected to the exclusion of PAX7-FOXO1. In comparative analysis, both FISH and PCR are useful in aiding the diagnosis of ARMS and excluding its sarcomatous mimics. FISH is more reliable technically but has less specificity than PCR. In cases where ARMS is in the differential diagnosis, it is optimal to perform both PCR and FISH: both have similar sensitivities for detecting ARMS, but FISH may confirm or exclude cases that are technically unsuccessful with PCR, while PCR can detect specific fusion transcripts that may be useful prognostically.

Meningeal alveolar soft part sarcoma confirmed by characteristic ASPCR1-TFE3 fusion

Sarcoma metastatic to the brain is uncommon and rarely occurs as the initial manifestation of tumor. Alveolar soft part sarcoma (ASPS) is a rare but well-studied subtype of sarcoma. A 39-year-old man presented with seizures due to a left temporal meningeal-enhancing lesion with striking brain edema on MRI. The patient underwent neurosurgical resection for suspected meningioma. Histology showed large tumor cells clustering and forming small nests, in places with pseudoalveolar pattern. Diastase-resistant periodic acid-Schiff revealed very rare granular and rod-like cytoplasmic inclusions. Immunohistochemistry showed convincing positivity only with vimentin and smooth muscle actin. The histological features were strongly suggestive of ASPS. At the molecular level RT-PCR and sequencing analysis demonstrated ASPCR1-TFE3 fusion confirming the histological diagnosis of ASPS. There was no evidence of primary extracranial tumor by physical examination and on chest and abdominal CT scan 11 months after presentation. ASPS typically arise from the soft tissues of the extremities and develop multiple metastatic deposits usually with a long clinical course. This case may represent primary meningeal ASPS although metastatic deposit from an undiscovered primary site cannot be entirely excluded.

Influencia do meloxicam sobre a perda ossea alveolar em periodontite experimental: avaliaçao histometrica em ratos

GURGEL, Bruno Cesar de vasconcelos.Influencia do meloxicam sobre a perda ossea alveolar em periodontite experimental: avaliaçao histometrica em ratos. 2003.97f. Dissertaçao (Mestrado) - Universidade Estadual de Campinas. Faculdade de Odontologia de Piracicaba. Piracicaba, 2003. Disponivel em: . Acesso em: 04 out. 2010.

Correção de colapsos da crista alveolar com tecidos duros

Introdução: Uma adequada planificação é condição sine qua non para o êxito do tratamento com implantes. No entanto, nem sempre a colocação dos implantes na posição tridimensional ideal é, logo à partida, viável. Neste contexto, a correção dos colapsos da crista óssea com tecidos duros assume especial importância. Objetivos: O objetivo desta revisão narrativa é avaliar a eficácia dos diversos procedimentos existentes para aumento do rebordo com tecidos duros, de forma a facilitar a escolha do tratamento ideal. Materiais e Métodos: Pesquisou-se nas bases de dados MEDLINE, B-on e Google Académico. As palavras-chave utilizadas foram: “guided bone regeneration”, “ridge augmentation”, “seibert classification”, “alveolar bone splitting”, “horizontal bone augmentation” e “vertical bone augmentation”. Deu-se especial ênfase a revisões sistemáticas e meta-análises. A pesquisa foi limitada a artigos publicados em inglês, espanhol e em português até abril de 2016. Foram ainda consultados os livros “Tratado de Periodontia Clínica e Implantologia Oral” de Lindhe et al. (2005), “Implantes Dentais Contemporâneos” de Misch et al. (2009) e “Reabilitação com implantes endo-ósseos” de Alcoforado et al. (2008). Resultados: De um modo geral, todos os procedimentos analisados obtiveram altas taxas de sobrevivência aquando da reabilitação com implantes. No entanto, não houve diferenças significativas entre as diversas técnicas que possam levar a uma conclusão relevante sobre qual a melhor técnica a utilizar para este tipo de procedimento. Conclusão: Há evidências insuficientes para sugerir qual a técnica que deve ser preferida para o aumento de rebordo com tecidos duros, pelo que mais estudos são necessários.

Influencia do meloxicam sobre a perda ossea alveolar em periodontite experimental: avaliaçao histometrica em ratos

GURGEL, Bruno Cesar de vasconcelos.Influencia do meloxicam sobre a perda ossea alveolar em periodontite experimental: avaliaçao histometrica em ratos. 2003.97f. Dissertaçao (Mestrado) - Universidade Estadual de Campinas. Faculdade de Odontologia de Piracicaba. Piracicaba, 2003. Disponivel em: . Acesso em: 04 out. 2010.

Prevenção da reabsorção óssea alveolar após extração dentária

Introdução: O processo alveolar é o conjunto de osso que se encontra em redor da raiz do dente. Este osso é sensível a uma variedade de fatores ambientais e fisiológicos que influenciam a sua integridade e o seu funcionamento. Como tal, a sua formação assim como a sua preservação é dependente da presença contínua do dente. A reabsorção do processo alveolar após extração dentária é uma consequência natural e fisiológica indesejável, que pode dificultar a colocação de um implante dentário na posição desejada. Com o aumento cada vez mais das demandas estéticas em medicina dentária, torna-se, portanto, necessário prevenir que a reabsorção óssea provoque este defeito na arcada dentária. Objetivos: Realizar uma revisão bibliográfica sobre as várias técnicas e materiais para preservação do rebordo alveolar, a fim de prevenir ou minimizar a reabsorção alveolar após extração dentária. Material e Métodos: A pesquisa foi realizada nas bases de dados Pubmed, B-on e Scielo, não foi aplicado nenhum limite temporal, e os critérios de inclusão foram artigos em língua inglesa e portuguesa. Num total de 164 artigos, selecionaram-se 82 estritamente relacionados com o tema. Os artigos excluídos desviavam-se do objetivo do trabalho ou eram inconclusivos. Selecionaram-se, também, capítulos do livro Clinical Periodontology and Implant Dentistry Volume 1 e 2, dos autores Niklaus P.Lang e Jan Lindhe. Desenvolvimento: De modo a compreender como o processo alveolar reabsorve, deve-se ter em conta as várias técnicas que se podem realizar para permitir uma boa quantidade de osso remanescente na arcada adequada a cada caso para uma possível reabilitação. As técnicas de preservação do osso alveolar após extração passam pela realização de técnicas cirúrgicas minimamente invasivas, estabilização do coágulo pelo princípio da cicatrização por primeira intenção usando membranas ou retalhos, preenchimento do alvéolo dentário com materiais de enxerto ou substitutos ósseos, terapias combinadas com a colocação de implantes imediatos e o recurso a células e fatores de crescimento. Conclusão: A preservação alveolar tem grande importância para uma posterior reabilitação oral com implantes com maior quantidade de osso disponível do que quando não é feita qualquer tipo de preservação. A extração das peças dentárias deve ser feita com cuidado para preservar ao máximo ou não danificar as superfícies ósseas remanescentes. É aconselhado que o encerramento da ferida seja por primeira intenção e que proporcione estabilidade ao coágulo, podendo ser usado retalhos ou mesmo membranas. O uso de enxertos ósseos tem uma importante função de proporcionar uma matriz para o coágulo se formar e promover o processo de cicatrização. O método de implante imediato, para além de ser bastante usado, tem como finalidade o conforto para o paciente de não ser submetido a uma posterior cirurgia para colocação do mesmo e, simultaneamente, mantem a estabilidade dos tecidos moles. Ainda uma técnica menos usada é com células e fatores de crescimento que proporciona uma cicatrização mais rápida e um aumento do potencial regenerativo dos tecidos.