Abstract The utilization of oral lesions as a screening tool for HIV is not well documented. Attendees at two primary health care facilities (Khutsong and Heidelberg) were assessed to determine the predictive value of group I oral lesions for HIV infection. The objectives were to investigate the: 1) HIV prevalence amongst attendees at PHC facilities, 2) Prevalence of HIV-related oral lesions and 3) Correlation between the oral lesions and the HIV status using the Likelihood Ratio test. Methods: All patients over 12 months of age presenting at the two facilities for a curative care consultation over a one-week period (in April 2005) were included. Consent was obtained by trained counselors who also conducted a brief interview and offered pre-test counseling to patients wishing to know their HIV status. Two calibrated dentists conducted a head, neck and oral examination and administered a rapid saliva HIV test (OraQuick HIV-1/2-Rapid HIV-1/2 Antibody Test). Results: A total of 654 attendees were surveyed in the 2 facilities. There was a 100% response. The mean age of the participants was 34 years (range: 1-94), and the majority (73%) were female. HIV prevalence rates were 34% at Khutsong and 36% at Heidelberg. The HIV prevalence peaked at 46% in the 16-45 age groups. Of the 228 who tested positive for HIV, 121 (53%) patients were diagnosed with 1 or more Group I oral lesion. Oral candidiasis (46%) and oral hairy leukoplakia (19%) were the two most common oral lesions diagnosed in the HIV positive cohort. The positive predictive values and specificity values for multiple lesions ranged between 96% and 100%. Most of the likelihood ratios for multiple lesions were greater than 10 which implied that the patients who presented with these lesions were extremely likely to test positive for HIV. The sensitivity values (1% to 37%) and negative predictive values (66% to 70%) remained relatively low. Conclusion: The HIV prevalence of patients attending PHC facilities was high (34%). Oral lesions are useful markers of HIV-infection and should alert clinicians to the presence of HIV infection. Multiple group I lesions were more predictive of HIV infection compared to single lesions.

A toxoplasmose é causada pelo protozoário coccídio Toxoplasma gondii e consiste em um dos processos parasitários mais comuns entre os animais endotérmicos. A presença desse protozoário em cetáceos pode estar associada à exposição dos animais aos oocistos de T. gondii eliminados pelas fezes de felídeos e/ou contato com solo contaminado com o parasita, que tenham comprometido a água do mar a partir de drenagens fluviais e fluentes ou ainda pelo escoamento de água de navios. O objetivo desse trabalho foi investigar a ocorrência de T. gondii em cetáceos encalhados, ou provenientes de captura acidental, ou que vieram a óbito durante o processo de reabilitação ou cativeiro, ao longo da costa brasileira, valendo-se para tanto de avaliações histopatológicas e de técnicas imuno-histoquímicas (IHQ). Os principais órgãos examinados foram fígado, pulmão, linfonodos, baço e cérebro. Esse estudo avaliou tecidos de 186 exemplares de 21 espécies diferentes de cetáceos da costa brasileira entre 1988 e 2014, cujas amostras foram encaminhadas e encontram-se depositadas no Banco de Tecidos de Mamíferos Marinhos, do Laboratório de Patologia Comparada dos Animais Selvagens (LAPCOM) do Departamento de Patologia, FMVZ-USP. Dos mamíferos marinhos analisados, a ocorrência de T. gondii foi confirmada em 1,1% (2/186), justificada pela presença de pelo menos um cisto em pulmão e/ou fígado. Os animais positivos pertenciam a duas espécies diferentes, provenientes do sudeste do Brasil; um golfinho nariz-de-garrafa (Tursiops truncatus) encalhado vivo no Rio de Janeiro - RJ, e uma orca (Orcinus orca) proveniente de cativeiro. As principais observações histopatológicas encontradas foram hepatite necrotizante, broncopneumonia fibrinosa supurativa com presença de cistos compatíveis com T. gondii, pneumonia broncointersticial fibrinosa com carneificação, glomérulonefrite membranosa e linfadenite necrótica. Devido à severidade das lesões suspeita-se que esse protozoário teve um importante papel no encalhe/óbito desses dois indivíduos. Esse estudo acrescentou duas novas espécies de cetáceos àquelas já reportadas como suscetíveis à infecção pelo protozoário, mas nunca antes descritos no Brasil. Os resultados ratificaram a ocorrência da infecção por T. gondii em cetáceos da costa brasileira e a sua importância em mamíferos marinhos em cativeiro e de vida livre / Toxoplasmosis is caused by the coccidian Toxoplasma gondii - phylum Apicomplexa, which is one of the most common parasites affecting endothermic animals. The presence of T. gondii in cetaceans may be associated with feline feces and/or soil contaminated with the parasite, which may reach water bodies through run-off. This study investigated the occurrence of T. gondii in cetaceans along the Brazilian coast. Tissue samples of 186 individuals stranded along the Brazilian coast between 1988 and 2014, belonging to 21 species of cetaceans and currently part of the Marine Mammal Tissue Bank of the Laboratory of Comparative Pathology, Pathology Department, School of Veterinary Medicine and Animal Sciences, University of São Paulo. Immunohistochemistry (IHC) for T. gondii was performed using formalin-fixed, paraffin embedded tissue sections of liver, lung, lymph nodes, spleen and brain. Infected tissues of a Guiana dolphin (Sotalia guianensis) were used as positive controls. A total of 1.1 % (2/186) of the animals evaluated were positive, which was justified by the presence of least one cyst in one of the evaluated organs/tissues. These specimens belong to two different species of cetaceans: Killer whale (Orcinus orca) and bottlenose dolphin (Tursiops truncatus), both from southeastern Brazil. One individual stranded alive in Rio de Janeiro (T. truncatus); and one was kept in captivity (O. orca) in São Paulo state. The most noteworthy lesions observed through microscopy included necrotizing hepatitis, fibrinous suppurative bronchopneumonia with cysts compatible with T. gondii, bronchointersticial fibrinous pneumonia, membranous glomerulonephritis and necrotizing lymphadenitis. Due to the severity of lesions protozoan was suspected to have an important role in the stranding/death of the two wild individuals. This study added two new species of cetaceans to those already reported as susceptible to infection by T. gondii, never before described in Brazil. These results confirm the occurrence of T. gondii infection in cetaceans from the Brazilian coast and the importance of this parasite to marine mammals kept in captivity and free ranging dolphins

Introdução: As feridas agudas e crônicas provocam alterações físicas, psíquicas, sociais e econômicas para o indivíduo e família. Embora bem estabelecidos os dados epidemiológicos sobre essas lesões no contexto internacional, ainda são incipientes no Brasil, principalmente na Região Amazônica. Objetivo: Identificar e analisar a prevalência e fatores demográficos e clínicos associados à ocorrência de algumas feridas agudas e crônicas (Lesão por Fricção LF, Dermatite Associada à Incontinência DAI, Ferida Operatória Complicada FOC, Lesão por Pressão LP e Úlcera Diabética - UD) em pacientes hospitalizados. Métodos: Trata-se de estudo epidemiológico, observacional, transversal, analítico e descritivo, realizado em sete hospitais da cidade de Manaus. Os dados foram coletados por meio de consulta aos prontuários, entrevistas com os pacientes ou responsáveis legais e exame físico de todos os pacientes internados, durante o período de março a junho de 2015. As lesões encontradas foram avaliadas utilizando-se os seguintes instrumentos: Sistema de Classificação STAR - Lesão por Fricção para as LF; Incontinence Associated Dermatitis Intervention Tool (IAD-IT) para DAI; Pressure Ulcer Scale for Healing PUSH pernas, para FOC, Pressure Ulcer Scale for Healing PUSH UP para LP e Classificação de Wagner para as UD. Ademais, instrumento para levantamento dos dados sociodemográficos e clínicos e a Escala de Braden também foram empregados. Os dados foram analisados por meio de: teste Qui-quadrado ou exato de Fisher para as variáveis categóricas e teste t para as numéricas. Modelo de árvore de decisão com o algoritmo Classification and Regression Tree (CART) foi utilizado para identificação dos fatores associados à presença das feridas, de maneira simultânea e isolada. Resultados: A amostra (n=775) foi predominantemente do sexo masculino (457/ 58,9%), com média de idade de 60,4 anos (DP=18,7) raça parda (240/30,9%); situação conjugal com companheiro (413/53,2%) e ensino fundamental (403/52,0%). Cento e setenta e oito pacientes apresentaram lesões durante a coleta de dados, acarretando prevalência pontual global de 23%. Com média de 1,1 ferida (DP=0,4) por paciente, predominaram as LP (n=80/ 10,3%), seguidas de UD (n=66/ 8,5%). Os demais tipos de feridas mostraram prevalências de 2,7% (n=21) para FOC; 0,9% (n=7) para LF e 0,5% (n=4) para DAI. A maior ocorrência das lesões quanto às regiões corporais foram o dorso da mão E para a LF; região dos grandes lábios para DAI; perna E para FOC; região sacra para LP e: planta do pé E para UD. O CART mostrou Diabetes Mellitus, uso de anticoagulante, presença de rigidez, escore de Braden sem risco (>18), presença de curativo e de hematoma como os fatores associados à presença de todas as feridas, de forma simultânea, repetindo-se algumas dessas condições para LP e UD. Conclusão: O estudo, inédito na região amazônica, possibilitou um diagnóstico mais acurado da epidemiologia de algumas das mais importantes e prevalentes feridas agudas e crônicas, em pacientes hospitalizados, como a LF (0,9%), DAI (0,5%), FOC (2,7%), LP (10,3%) e UD (8,5%). Com prevalências pontuais inferiores à maioria dos resultados de estudos nacionais e internacionais, o estudo suscita a necessidade de mais investigações na região, particularmente estudos de incidência, mesmo que a maioria dos fatores associados constatados nos pacientes hospitalizados amazonenses esteja também presente na literatura. / Introduction: Acute and chronic wounds provoke physical, psychological, social and economic changes for individuals and their families. While, in an international context, epidemiological data regarding these wounds and lesions is well established, it is still in an incipient stage in Brazil, particularly in the Amazon Basin Region. Objective: To identify and analyze the prevalence and demographic and clinical factors associated with the occurence of several acute and chronic wounds (frictional lesions - frictional keratosis, incontinence-associated dermatitis - IAD, post-operative wound complications, pressure sores and diabetic ulcers) in hospitalized patients. Methods: This is an observational, transverse, analytical and descriptive epidemiological study conducted in seven hospitals in the city of Manaus. The data was collected by consulting hospital records, interviews with patients or legal guardians and physical examinations of all hospitalized patients, during the period from March through June 2015. The lesions found were evaluated using the following instruments: Classification System STAR -- Frictional Lesion for frictional lesions; Incontinence Associated Dermititis Intervention Tool (IAD-IT) for IAD; Pressure Ulcer Scale for Healing - PUSH UP for pressure sores and Wagner Classification for diabetic ulcers. Moreover, an instrument for socio-demographic and clinical data collection and the Braden Scale were also employed. The data was analyzed by way of the Chi-squared distribution test or T-Test for numerical ones. The decisionmaking tree model using the Classification and Regression Tree (CART) algorithm was utilized in the identification of factors associated with the presence of lesions, simultaneously and in isolation. Results: The study sample (n=775) was predominantly of the male sex (457 / 58,9%) with an average age of 60.4 years (DP=18.7) mulatto (240/30.9%); marital situation with spouse (413/53.2 %) and elementary school complete (403/52.0%). One hundred and seventy-eight patients presented lesions during the datacollection period, leading to an overall point prevalence of 23%. With an average of 1.1 lesions (DP=0.4) per patient, pressure sores predominated (n=80/10.3%), followed by diabetic ulcers (n=66/8.5%). The remaining types of lesions showed a prevalence of 2.7% (n=21) for post-operative wound complications; 0.9% (n=7) for frictional lesions and 0.5% (n=4) for incontinence associated dermititis (IAD). The primary occurence of lesions to particular parts of the body were frictional lesions to the back of the left hand; incontinence associated dermititis lesions to the region of the outer labia; post-operative wound complications to the left leg; pressure sores to the sacrum; and diabetic ulcers to the sole of the left foot. CART showed Diabetes Mellitus, the use of anticoagulants, the presence of rigidness, the Braden score without risk (>18), the presence of bandages and bruises as factors simultaneously associated with the presence of lesions, repeating some of these conditions for pressure sores and diabetic ulcers. Conclusion: The study, unprecedented in the Amazon Basin region, made a more accurate epidemiological diagnosis possible of some of the most important and prevalent acute and chronic lesions in hospitalized patients, such as frictional lesions (0.9%), IAD (0.5%), post-operative wound complications (2.7%), pressore sores (10.3%) and diabetic ulcers (8.5%). With point prevalences inferior to the majority of national and international studies, despite the fact that the majority of the associated factors found in hospitalized Amazonian patients are the same as those present in a review of the literature, this study evokes the need for more investigation throughout the region,.particularly incidence studies.

O antantreno é um hidrocarboneto hexacíclico aromático (HPA) bastante difundido no meio ambiente e que não apresenta as regiões de baía ou fjord, que em geral, conferem alta reatividade a esses compostos após oxidação. Entretanto, sua mutagenicidade em bactérias após ativação metabólica é comparável à do Benzopireno (BP) e, com base na sensibilidade das linhagens de S. typhimurium utilizadas, os metabólitos do antantreno causam substituições de pares de base, trocas de fita e possivelmente dano oxidativo ao DNA. Alguns dos metabólitos que apresentam ação genotóxica em bactérias foram recentemente identificados, mas uma investigação mais ampla considerando a ligação desses e outros possíveis metabólitos a biomoléculas, com a identificação dos adutos formados, pode contribuir para um melhor esclarecimento das vias envolvidas em sua genotoxicidade. Neste trabalho investigamos a reação do antantreno (oxidado quimicamente e pelo sistema HRP/H2O2) com dG e DNA in vitro, tendo sido observada a formação de possíveis adutos nas análises por HPLC/ESI/MS, HPLC/UV/Fluorescência e espectrofluorimetria. Células de carcinoma hepatocelular humano (HepG2) e hepatócitos de fígado humano normal (THLE-2) foram incubadas com antantreno e seus produtos de oxidação (quinonas e hidroquinonas acetiladas), verificando-se citotoxicidade dose dependente em diferentes condições de cultura. Uma vez que a sobrevivência relativa das células THLE-2 cultivadas sobre filme de colágeno e em meio PFMR-4 se assemelhou à sobrevivência relativa das células HepG2 cultivadas em meio DME e sem filme de colágeno, utilizamos as células HepG2 para análise de dano oxidativo. Produtos de oxidação do antantreno (quinonas e hidroquinonas acetiladas) induziram a formação de 8-oxodGuo no DNA celular. Os dados obtidos nos indicam que duas vias podem estar envolvidas na genotoxicidade do antantreno observada nos estudos com S.typhimurium realizados por Platt et al. (2002): indução de dano oxidativo e formação de adutos com o DNA. / Anthanthrene is a polycyclic aromatic hydrocarbon (PAH) widely spread in the environment and does not have the bay or fjord regions, which in general provide high reactivity to these compounds after oxidation. However, its mutagenic activity to bacteria after metabolic activation is comparable to that of benzopyrene (BP) and, based on the sensitivity of the S. typhimurium strains used, anthanthrene metabolites cause base pair substitutions, DNA strand exchanges, and possibly DNA oxidative damage. Some of the metabolites that are genotoxic to bacteria have been recently identified, but a better investigation on how these and other possible metabolites react with biomolecules, identifying the generated adducts, can contribute to clarify the ways involved in its genotoxicity. In the present work we investigated the reaction of anthanthrene (chemically oxidized or oxidized by the HRP/H2O2 system) with dG and DNA in vitro. The formation of possible adducts was observed in the analyses by HPLC/ESI/MS, HPLC/UV/Fluorescence and spectrofluorimetry. Human hepatocelular carcinoma cell line (HepG2) and normal human liver hepatocytes (THLE-2) were incubated with anthanthrene and its oxidation products (quinones and acetyladet hidroquinones). Dose dependent cytotoxity was observed under different culture conditions. As the relative survival of the THLE-2 cells grown on a film of collagen in PFMR-4 medium was very close to the relative survival of the HepG2 cells grown in DME medium, without the collagen film, we used the HepG2 cells for analysis of oxidative damage. Anthanthrene oxidation products (quinones and acetylated hidroquinones) induced 8-oxodGuo formation in the cellular DNA. Data obtained indicate that two ways may be involved in the genotoxicity of anthanthrene observed in the S. typhimurium studies conducted by Platt et al. (2002): DNA oxidative damage and adducts formation.

Orientador: Christiane Pienna Soares / Banca: Christiane Pienna Soares / Banca: Rubens Rodrigues dos Santos Júnior / Banca: Luís Carlos Spolidório / Resumo: O câncer de laringe é a segunda neoplasia mais comum da região de cabeça e pescoço em todo o mundo. Além dos fatores de risco como fumo e consumo de àlcool, o desenvolvimento do câncer de laringe parece estar associado à infecção pelo Papilomavírus Humano (HPV). As moléculas HLA-G e HLA-E são moléculas HLA de classe I não- clássicas, que desempenham um papel no estabelecimento da manutenção da tolerância imunológica através da inibição de funções de células imunocompetentes. O presente estudo tem como objetivo avaliar a expressão de HLA-G e HLA-E pela técnica imunohistoquímica em biópsias laríngeas de 109 pacientes, 27 lesões benignas (papiloma laríngeo), 17 lesões pré- malignas (displasia leve, moderada ou acentuada), 10 carcinomas in situ de laringe, 27 carcinomas invasores sem metástase, 28 carcinomas invasores com metástase. Além das biópsias avaliadas, também foram analisadas 28 linfonodos cervicais dos pacientes com metástases. A molécula de HLA-G foi detectada em 45% das biópsias analisadas. Dentre os diferentes graus histológicos, a expressão da molécula HLA-G aparece aumentada nas lesões benignas, lesões pré- malignas e carcinomas in situ de laringe, e essa expressão diminui nos carcinomas invasores sem metástase, carcinomas invasores com metástase e nos linfonodos. HLA-E foi detectado em 62,04% das lesões como um todo, havendo um aumento da expressão de HLA-E nas lesões invasivas e nos linfonodos. Esta molécula parece estar associada com a instalação do carcinoma laríngeo. A freqüência do DNA do HPV foi baixa, sugerindo que o câncer de laringe esteja associado a outros fatores de risco. / Abstract: Laryngeal carcinoma is a second common malignant tumor of the head and neck around the world. Besides well-established risk factors like smoking and alcohol abuse, the development of laryngeal carcinoma is associated with human papillomavirus (HPV) infection. HLA-G and HLA-E are two non-classical class I molecules. Their antigens play a role in the establishment and maintenance of immune tolerance by inhibiting the functions of immunocompetent cells. The aim of the present retrospective study was to determine the expression of HLA-G and HLA-E immunoperoxidase in laryngeal biopsies from 109 patients, 27 in benign lesions (laryngeal papillomas), 17 premalignant lesions (low, moderate or severe dysplasia), 10 in situ laryngeal carcinomas, 27 laryngeal carcinomas without metastases, 28 laryngeal carcinomas with metastases. Besides all biopsies evaluated, were also analyzed 28 biopsies of patients with cervical lymph node metastases. The HLA-G molecule was detected in 45% of biopsies analyzed. Among the different histological grades, the expression of HLA-G molecule is increased in benign lesions, premalignant lesions and in situ laryngeal carcinomas, and this expression decreases in invasive carcinoma without metastasis, invasive carcinoma with metastasis and lymph nodes. HLA-E was detected in 62.04% of the lesions as a whole, with increased expression of HLA-E in invasive lesions and lymph nodes. This molecule seems to be associated with the installation of laryngeal carcinoma. The frequency of HPV DNA was low, suggesting that cancer of the larynx is associated with other risk factors. / Mestre

Optical Coherence Tomography (OCT) is an imaging technique that uses near infra-red light to non-invasively form cross-sectional images of specimens, in a similar way to ultrasound and RADAR. A number of research groups have used OCT to study natural and artificial carious lesions and to some extent erosive lesions. For this, a variety of in vitro models have been used. However, the exact mechanism by which these demineralised enamel lesions affect the OCT measurements is not fully understood. This remains a barrier to its adoption as both an analytical laboratory tool and a widespread technique in clinical dentistry. Therefore, the aim of this thesis was to develop an understanding of how different demineralised enamel lesions manifest in OCT measurements. This is necessary for the technique to become useful as an in vivo clinical measurement and imaging system. Consequently, this study was carried out in a controlled laboratory environment for which a novel specimen holder was designed. This mitigated against specimen movement and maintained specimen hydration, which can be a source of uncertainty in the measurements. A custom-built OCT microscope was used for this work, which enabled automation of experiments and continuous time-lapse OCT imaging over time periods of hours to several days. This enabled bovine enamel demineralisation dynamics to be captured during in vitro caries and erosion formation. The stability of the system also enabled direct comparison between the OCT measurements of the optical properties of different demineralisation models. To achieve these measurements, the OCT system was carefully characterised and compared to established profilometry measurements. Interestingly, this revealed that the experimental protocol used to obtain lesions for profilometry was not to be representative of the lesions formed and measured by OCT. This is an important point when interpreting OCT data in light of other techniques. A novel method of analysis was developed that uses longitudinal OCT image correlation to quantify early stage surface softening during erosion. By using OCT volumetric data, this technique was able to measure sub-resolution changes at the specimen surface. Early results also indicate sensitivity to remineralisation. This thesis shows that OCT is sensitive to different demineralisation models produced and measured under controlled conditions. New method of handling the data can observe changes not previously seen in OCT. However, further work is still required to understand the underlying physical changes that lead to this sensitivity in OCT.

Enamel damage and demineralisation are common complications associated with fixed orthodontic appliances. In particular, the clean-up of adhesive remnants after debonding is a recognised cause of enamel damage. Furthermore, fixed attachments offer retentive areas for accumulation of cariogenic bacteria leading to enamel demineralisation and formation of white spot lesions (WSLs). Bioactive glasses may be used to remove adhesives, preserving the integrity of the enamel surface, while also having the potential to induce enamel remineralisation, although their efficacy in both respects has received little attention. A systematic review evaluating the remineralisation potential of bioactive glasses was first undertaken. No prospective clinical studies were identified; however, a range of in vitro studies with heterogeneous designs were identified, largely providing encouraging results. A series of glasses was prepared with molar compositions similar to 45S5 (SylcTM; proprietary bioactive glass) but with constant fluoride, reduced silica and increased sodium and phosphate contents. These glasses were characterised in several tests and the most promising selected. This was designed with hardness lower than that of enamel and higher than orthodontic adhesives. Its effectiveness in terms of removal of composite- and glass ionomer- based orthodontic adhesives was evaluated against SylcTM and a tungsten carbide (TC) bur. This novel glass was subsequently used for remineralisation of artificially-induced orthodontic WSLs on extracted human teeth. The novel glass propelled via the air-abrasion system selectively removed adhesives without inducing tangible physical enamel damage compared to SylcTM and the conventional TC bur. It also remineralised WSLs with surface roughness and intensity of light backscattering similar to sound enamel. In addition, mineral deposits were detected on remineralised enamel surfaces; these acted as a protective layer on the enamel surface and improved its hardness. This layer was rich in calcium, phosphate, and fluoride; 19F MAS-NMR, confirmed the formation of fluorapatite. This is particularly beneficial since fluorapatite is more chemically stable than hydroxyapatite and has more resistance to acid attack. Hence, a promising bioactive glass has been developed.

Objectives: 1) To develop and investigate the bioactivities of a novel bioactive glass (BAG) composite designed as an orthodontic adhesive. 2) To investigate the preventive effect, and to test the bond strength of the adhesive. Methods: A novel, calcium and phosphate rich, and fluoride containing, bioactive glass (BAG) was prepared via the melt quench route and incorporated into an experimental resin to produce a light cured paste. The ratio of the resin to the powder was 20:80% respectively. The BAG powder was gradually replaced by a high fluoride and silica content glass (HSG) from 80%, to 60%, 50%, 40%, 25% and 0%. 90 disks (1.26mm thickness and 10mm diameter) were produced from each composition to be immersed in 3 solutions (demineralising artificial saliva pH=4 (AS4), remineralising artificial saliva pH=7 (AS7) and Tris buffer (TB) pH=7.3, 10 ml each. Measurements were taken at 10 time points (from 6 hours to 6 months) in 3 replicas in each solution. Ion release study was determined by ISE and ICP, and pH monitoring was conducted on the resulting solutions. Immersed disks were studied by FTIR, XRD, MAS-NMR and SEM for apatite formation. XMT were used to study the effects of this material on demineralisation/remineralisation in human enamel. Shear bond strength of the adhesive on bovine enamel were studied in different conditions using an Instron machine. Results: The pH increased with time for all the samples with BAG in all solutions and was linearly correlated to BAG loading. Ion release results revealed that the composite disks release up to 15ppm F-, 450ppm Ca2+ and 10ppm PO43- ions, and the release pattern is directly related to the immersion time, with the highest release found in AS4. FTIR spectra, XRD patterns and SEM images showed formation of apatite on all the BAG-resin disks, especially in AS4 and this increase with time. The MAS-NMR spectra indicated fluorapatite was also formed. The XMT studies showed that the novel material reduces demineralisation around the brackets by 80%. The shear bond strength of this novel material was comparable to that of Transbond XT. Conclusion: The novel BAG composites have significant long term releases of F-, Ca2+ and PO43- ions, especially in acidic conditions and form apatite (including FAP) in acidic and neutral solutions. This implies that the material has the potential as an orthodontic adhesive that can prevent white spot lesions around brackets.

Introduction: Lacunar strokes are both common and disabling; they cause up to 52 strokes per 100,000 people per year and 29-46% of survivors are disabled. Lacunar stroke is part of the spectrum of small vessel disease (SVD) which also causes cognitive impairment and gait disturbance; together these lead to dementia, falls and disability. Current evidence suggests that SVD is caused by a separate aetiology from large vessel stroke, which may be mediated by blood brain barrier (BBB) permeability and may affect organs other than the brain. We set out to establish whether SVD is a multi-system disorder of primary endothelial function, with leakage of blood-brain barrier leading to lacunar stroke, disability, and cognitive impairment. Methods: We recruited 264 patients with a lacunar or cortical stroke (118 lacunar, 146 cortical). All patients received baseline assessment of clinical features, magnetic resonance imaging (MRI), renal function, and assessment of dietary salt. At 1-3 months post-stroke we carried out cognitive testing and contrast MRI to assess blood-brain barrier integrity. We followed patients up at 12 months post-stroke with repeat cognitive testing, MRI, and assessment of disability and recurrent stroke. Results: We established that lacunar stroke has a different risk factor profile to cortical stroke, confirming findings from previous cohorts, but adding dietary salt as a risk factor for lacunar stroke and other SVD features. We confirmed that patients with a clinical stroke who did not have a lesion on diffusion-weighted MRI had the same clinical outcomes at 1 year post-stroke as those patients who did have a lesion. We established that patients who have a lacunar stroke are at as high a risk of post-stroke cognitive impairment as those with a cortical stroke. We found that blood brain barrier leakage predicted cognitive impairment at one year after lacunar and cortical stroke. We established the rates of disability and cognitive impairment at one-year post-lacunar stroke to estimate the required sample size for future trials. Conclusions: Taken together these findings confirm that lacunar stroke is part of a syndrome separate to large vessel stroke and may be mediated through blood brain barrier leakage. Dietary salt is an additional risk factor. The findings support further randomised controlled trials of treatments aimed specifically at lacunar stroke and lifestyle interventions including dietary salt reduction.

Made available in DSpace on 2014-06-11T19:30:52Z (GMT). No. of bitstreams: 0 Previous issue date: 2002Bitstream added on 2014-06-13T19:19:33Z : No. of bitstreams: 1 castilho_ec_dr_botfm.pdf: 693976 bytes, checksum: bbfa4da3f523001acac2d23b6b1ac73b (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Justificativa: as lesões da mucosa traqueal em contato com o balonete do tubo traqueal são proporcionais à pressão exercida pelo balonete e ao tempo de exposição. Objetivo: estudar as eventuais lesões da mucosa do segmento traqueal em contato com o balonete do tubo traqueal insuflado com volume de ar suficiente para se obter a pressão de “selo” para impedir vazamento durante ventilação artificial, ou com a pressão “crítica” de 25 cm H2O. Método: dezesseis cães foram submetidos à anestesia venosa com pentobarbital sódico e ventilação com fluxo total de gases frescos de 2 L.min-1. Os cães foram distribuídos aleatoriamente em dois grupos de acordo com a pressão no balonete de grande volume do tubo traqueal (Portex Blue-Line, Inglaterra): G1 (n=8) balonete insuflado até a obtenção da pressão mínima de “selo” necessária para impedir vazamento de ar durante a respiração artificial; G2 (n=8) balonete insuflado até atingir a pressão de 25 cm de H20. A medida da pressão do balonete foi realizada por meio de manômetro digital (Mallinckrodt, EUA) no início do experimento (controle) e após 60, 120 e 180 minutos. Após osacrifício dos cães, foram feitas biópsias nas áreas traqueais adjacente ao tubo traqueal para análise à microscopia óptica (MO) e microscopia eletrônica de varredura (MEV). Resultados: à MO, evidenciaram-se mínimas alterações em ambos os grupos, mais significantemente em G1, em duas áreas da parede anterior da traquéia: uma em contato com o balonete (BB1) e outra abaixo do tubo traqueal (BP1) (p=0,002). À MEV as alterações não foram significantemente diferente nos grupos (p>0,30), mas ocorreram lesões mais intensas nas áreas de contato com o balonete nos dois grupos (p<0,05). Conclusões: no cão, nas condições experimentais empregadas... / Background: The lesions of the tracheal mucosa in contact with the endotracheal tube cuff are proportionally related to the intracuff pressure and to the time of exposition. Objective: the aim of this work was to study the development lesions of tracheal mucosa in contact with the endotracheal tube cuff inflated to reach the “sealing” pressure in order to avoid leaking during the artificial ventilation or with the “peak” inflation pressure of 25 cm H2O. Methods: sixteen dogs were submitted to intravenous anesthesia with pentobarbital sodium and ventilation with total flow of fresh gases of 2 L.min-1. The dogs were randomly distribuited into two experimental groups according to the pressure in the high volume cuff of the endotracheal tube (Portex Blue Line, Inglaterra): G1 (n=8) the cuff was inflated in order to reach the sealing minimum pressure to avoid air leaking during the artificial respiration; G2 (n=8) the cuff was inflated to reach the pressure of 25 cm H2O. The intracuff pressure was measured with a digital manometer (Mallinckrodt, EUA) at the beginning of the experiment (control) and after 60, 120 and 180 minutes. The animals were sacrificied and biopsies were perfomed from the areas of the trachea adjacent the endotracheal tube to be analysed by light microscopy (LM) and scanning electronic microscopy (SEM). Results: The light microscopy showed mild and similar alterations in both groups. However G1 revealed alterations most frequently in two different areas of trachea anterior wall: one lesion in direct contact with the cuff (BB1) and the other lesion just below the tracheal tube (BP1) (p=0.002). The scanning electronic microscopy also showed similar alterations in both groups (P>0.30), with more. Conclusions: In the dog, considering the experimental conditions used... (Complete abstract, click electronic address below)