This study is a secondary analysis of survey data collected in fall 2000 from patients of a safety-net hospital and its eight community health outreach clinics in Fort Worth, Texas. The study examined three objectives. These include explaining the utilization of Pap smear tests among the sample who were low-income women, by ascertaining the determinants of using these services. Using binary logistic regressions analyses primarily, the study tested 10 hypotheses. The main hypothesis tested the race/ethnicity/immigration status effect on Pap smear screening. The remaining hypotheses examined the effects of other independent/control variables on having a Pap smear. Results from the data provide support for the existence of a race/ethnicity/immigration status effect. Anglos were more likely to have had a Pap smear, followed by African Americans, Hispanic immigrants, and finally, by Hispanic Americans. The persistence of the race/ethnicity/immigration status effect, even when the effects of other independent/control variables are taken into account, may be explained by several factors. These include cultural differences between the different groups studied. The race/ethnicity/immigration status effect on Pap smear screening changed with the introduction of age, usual source of care, check-up for current pregnancy, and having multiple competing needs for food, clothing and housing into the models studied. Other variables, such as marital status, employment status and health insurance coverage had no statistically significant effects on Pap smear screening. The findings of this study are unique, probably due to the hospital-based sample who has regular access to subsidized health insurance from a publicly funded safety-net healthcare network and its healthcare providers. Given the importance of race/ethnicity/immigration status for preventive Pap smear screening, public education efforts to promote appropriate Pap smear tests among vulnerable populations should target specific race/ethnicity/immigration status groups in the U.S. within the cultural context of each group. Furthermore, publicly funded health programs for underserved populations such as the John Peter Smith Connections and Medicaid should be maintained and strengthened.

O presente estudo avaliou a adição de fibras cerâmicas de 0,5mm de diâmetro de Al2O3/GdAlO3 obtidas por fusão a laser (método LHPG - laser heated pedestal growth) em porcelanas de cobertura dos sistemas In Ceram Alumina, In-Ceram 2000 Al Cubes e In-Ceram 2000 YZ Cubes para CEREC (VITA Zahnfabrik). Barras confeccionadas apenas com a porcelana de cobertura (VM7 ou VM9 - monolayers) ou constituídas por ambas a cerâmica da infraestrutura e porcelana de cobertura (bilayers) receberam as fibras dispostas longitudinalmente nas proporções de 10 ou 17% vol. Barras que não receberam fibras serviram como controle dos grupos. Os corpos-de-prova (CP) com fibras assim como os do grupo controle foram submetidos a um teste de flexão em três pontos. Foram calculadas as médias para a densidade e resistência à flexão dos CP, assim como para as fibras isoladamente. A tenacidade à fratura das fibras também foi mensurada. Em todos os casos a análise de variância de um fator e o teste de Tukey com 5% de significância foram aplicados. Microscopia eletrônica de varredura foi utilizada para caracterização microestrutural das fibras e para estudo fractográfico. Foram realizadas análises de difratometria por raio-x dos materiais cerâmicos nos estados pré e pós-sinterização, assim como foram determinados os coeficientes de expansão térmico-linear das porcelanas de cobertura por dilatometria. Os CP monolayers da porcelana VM9 contendo fibras apresentaram, após a sinterização, trincas e falhas, o que impediu a continuidade dos testes com os grupos de cerâmicas do sistema In-Ceram 2000 YZ Cubes. Os CP com fibras adicionadas à porcelana VM7 em 17% vol. apresentaram resistência à flexão aumentada em 43% comparados aos CP do grupo controle, sem fibras. Nos grupos bilayers as fibras propiciaram aumento apenas numérico da resistência à flexão do conjunto, porém de forma não significante. / This study evaluated the addition of 0.5mm of diameter Al2O3/GdAlO3 fibers obtained by LHPG (Laser Heated Pedestal Growth) to veneering porcelains of the following materials: porcelain monolayers: VM7 and VM9; Bilayers: In-Ceram Alumina + VM7, In-Ceram 2000 AL Cubes + VM7 and In-Ceram 2000 YZ Cubes for CEREC + VM9 (VITA Zahnfabrik). The specimens (bars) were composed by only the veneer porcelain (monolayer) or both the veneer and the framework (bilayer). The new ceramic composites contained longitudinal fibers in 10 or 17% vol. Specimens without fibers were used as control. A metallic device was developed for the standardization of the fibers position inside the specimens. The means of the fracture toughness, density and flexural strength of the developed fibers were calculated as well as the density and flexural strength of the composites. One way ANOVA and a Tukey test (5%) were applied. Characterizations of fiber/porcelain interface and fractographyc analysis were carried out after scanning electronic microscopy (SEM) of bars. X-ray difratometry and dilatometry were also performed. Vm9 porcelain showed incompatibility with the fibers, probably due to differences between the coefficients of thermal expansion of fibers and porcelain. VM7 monolayers with the addition of 17% of fibers in volume showed significantly higher resistance in relation to control. It was concluded that the inclusion of ceramic fibers of Al2O3/GdAlO3 to veneer porcelain improves its flexural strength.

A atual tendência ao desenvolvimento de uma odontologia minimamente invasiva tem sido responsável pela introdução de instrumentos e técnicas alternativas de preparo cavitário. Porém, tais tecnologias deveriam não somente preencher os requisitos de uma odontologia conservadora, mas também preparar as paredes da cavidade para o tratamento restaurador adesivo subseqüente. Assim, o objetivo deste estudo foi testar a hipótese nula de que: 1) tanto técnicas convencionais quanto técnicas alternativas de preparo cavitário são capazes de produzir um substrato dentinário receptivo à adesão de sistemas autocondicionantes; e 2) A efetividade adesiva de sistemas autocondicionantes não é influenciada pela interposição da camada de esfregaço. Cem molares humanos íntegros foram aleatoriamente divididos em 20 grupos de acordo com o adesivo e a técnica ou instrumento utilizado. Superfícies planas de dentina média oclusal foram preparadas com instrumento rotatório diamantado convencional (IR); fratura; instrumento rotatório CVD (IRCVD); instrumento ultra-sônico CVD (IUCVD); e laser de Er,Cr:YSGG .Um adesivo condicione-e-lave (Optibond FL/OB) e três autocondicionantes (Adper Prompt L-Pop/AP, Clearfil SE Bond/SE e Clearfil S3 Bond/S3) foram empregados. Os espécimes foram construídos com o compósito Z100/3M ESPE. A resist6encia adesiva foi determinada por meio de teste de microtração após 24 h de estocagem em água a 37oC. Amostras adicionais foram processadas para análise em MEV quanto às características morfológicas apresentas após o preparo das superfícies dentinárias em cada caso. O teste de Kruskal-Wallis (p<0,05) determinou que os grupos preparados com IRCVD, IUCVD e laser apresentaram menores valores de resistência adesiva quando comparados aos grupos controle (IR e fratura). Além disso, os adesivos de menor acidez (SE e S3) foram mais eficientes quando aplicados em dentina fraturada. Concluiu-se que o uso de instrumentos e técnicas alternativas de preparo cavitário comprometeu a adesão à dentina e que a camada de esfregaço influencia de forma negativa a adesão de sistemas autocondicionantes suaves. / The current trend toward minimal invasive dentistry has introduced alternative cavity preparation techniques. However, these technologies should not only fulfill the requirements of a conservative philosophy, but also prepare the cavity walls for the subsequent bonding restoration. The purpose of this study was to assess the null hypotheses that: (1) both conventional and alternative cavity preparation techniques are equally receptive to adhesion; and (2) bonding effectiveness of mild adhesives is not influenced by smear layer (SL) interposition. Eighty sound human molars were divided into 20 groups according to adhesive and cavity preparation technique. Flat mid-occlusal dentin surfaces were prepared with regular diamond bur (DB), scalpel blade (SB), CVDentus bur in high speed turbine (CB), CVDentus tip in ultrasound (CT), and Er,Cr:YSGG laser (L). One etch-and-rinse (Optibond FL (OB)) and three self-etch systems (Adper Prompt L-Pop (AP), Clearfil SE Bond (SE) and Clearfil S3 Bond (3S)) were employed. Specimens were built up with Z100/3M ESPE composite. The microtensile bond strength was determined after 24h of storage in water at 37oC. Additional samples were processed for SEM analysis on morphological aspects in each situation. Kruskal-Wallis test (p<0,05) determined that groups prepared with CB, CT and L presented lower ?TBS values than the control groups (DB and SB), and that adhesives with lower acidity (SE and 3S) were more effective when applied on fractured surfaces (SB). It was concluded that the use of alternative techniques for cavity preparation caused damages to dentin surface, compromising the adhesion to this substrate. Moreover, the bonding effectiveness of mild adhesives was improved by SL absence.

Les Papillomavirus Humains (HPV) sont responsables de près de 100% des cancers du col utérin. Récemment, ces HPV sont apparus comme étant aussi la cause de certaines tumeurs des voies aérodigestives supérieures, et particulièrement des carcinomes épidermoïdes de l’oropharynx. En France, la proportion des tumeurs oropharyngées HPV-induites est mal connue, notamment parce que le dépistage viral n’est pas recommandé. De plus, il est difficile d’évaluer la proportion de tumeurs HPV positives dans les tumorothèques car les échantillons tumoraux sont fixés dans du formol puis inclus en paraffine (FFIP), ce qui complexifie les techniques de détection. Nous avons, au cours de nos travaux, testé une méthode de détection des HPV à haut risque oncogène indiquée pour le traitement des frottis en phase liquide. Nous l’avons mise à l’épreuve sur des prélèvements FFIP et comparée à la technique de référence qu’est la PCR (Polymerase Chain Reaction) suivie d’une électrophorèse sur gel. Nos résultats indiquent que cette technique est applicable aux prélèvements tissulaires et apparaît même comme étant plus sensible. En France, deux tiers des patients atteints de tumeurs des VADS sont pris en charge à des stades tardifs. Ceci s’explique en partie par l’absence de dépistage organisé de ces cancers. Nous avons donc mené une étude prospective sur des patients atteints d’une tumeur des VADS afin de tester le frottis oral comme technique de dépistage des cancers mais également des infections par les HPV. Nos résultats indiquent que le frottis a une spécificité proche de celle de la biopsie (94,4%) pour le dépistage des cancers des VADS, mais une moindre sensibilité (66,7%). Cette étude nous a permis de mettre en évidence une tumeur HPV-induite dans 12,2% des cas. Parmi eux, nous avons détecté grâce à un frottis buccal (en zone saine) une infection par un HPV à haut risque oncogène dans 53,3% des cas. L’OMS a classé les HPV comme agents carcinogènes depuis 1995, et a établi que les patientes ayant développé un cancer du col utérin avaient un risque 6 fois plus élevé de développer une autre tumeur HPV-induite. Dans ce contexte, nous avons prévu une étude prospective multi-centrique visant à dépister une infection orale par un HPV oncogène chez des patientes porteuses d’une lésion pré-néoplasique ou néoplasique du col utérin. Le taux de co-infection des deux sites anatomiques est inconnu chez les femmes infectées au niveau génital. Dans la mesure où l’infection orale pourrait être à l’origine d’une seconde localisation tumorale, il semble important d’en connaître la proportion afin de proposer par la suite un suivi particulier aux populations « à risque ». Au-delà des traitements des cancers avérés se pose la question de la vaccination préventive, qui existe contre les HPV 16 et 18 dans la prévention des cancers du col utérin. Le type 16 étant retrouvé dans 90% des tumeurs épidermoïdes de l’oropharynx HPV-induites, l’extension des recommandations vaccinales apparaît comme une nouvelle question de santé publique / The Human Papillomavirus (HPV) are involved in almost 100% of cervical cancers. Recently, HPVs have been recognized as the cause of tumors of the upper aerodigestive tract, especially of squamous cell carcinoma of the oropharynx. In France, the proportion of oropharyngeal HPV-related tumors is unknown, partly because viral testing is not in guidelines. Moreover, assess the proportion of HPV-positive tumors in tumor banks is difficult because the tumor samples were fixed in formalin and embedded in paraffin (FFPE), which complicates detection techniques. We tested a high risk HPV detection method, indicated for liquid based pap smear, on FFPE samples. We compared this technique to the gold-standard : PCR (Polymerase Chain Reaction) followed by electrophoresis. Our results indicate that this technique is applicable to FFPE samples and even appears to be more sensitive. The majority of French patients (2/3) with head and neck consult with an advanced stage of disease. This is explained in part by the lack of organized screening of these cancers, contrary to breast, prostate, cervical, or colorectal cancers. But an early treatment is essential to increase the survival rate. We therefore conducted a prospective study on patients with head and neck tumors to test the oral brushing as screening cancer and HPV detection. We found tumor and/or dystrophic cells in 97.8% of patients with biopsy, and in 88.9% of patients by brushing. Compared with biopsy, our results suggested that smear has similar specificity for HPV detection in tumors (94.4%), but lower sensitivity (66.7%). This study has shown an HPV-related tumor in 12.2% of cases. Among them, we detected by brushing (in healthy area) an oral infection by high-risk HPV in 53.3% of cases. WHO has classified HPV as carcinogenic agents since 1995, and determined that patients who developed cervical cancer are six-times more likely to develop another HPV-related tumor. In this context, we have planned a multicenter prospective study to detect oral HPV infection in patients with a pre-neoplastic or neoplastic lesion of the cervix. Co-infection rate of the two anatomical sites is unknown in women infected with genital level. Insofar oral infection could be the cause of a second tumor location, it seems important to know how much women are co-infected to propose thereafter a special monitoring. The preventive vaccination, which exists against HPV 16 and 18 in the prevention of cervical cancer, is a future perspective. Because HPV 16 is found in 90% of HPV-related squamous cell carcinoma of the oropharynx, extending vaccine recommendations emerge as a new public health issue

Made available in DSpace on 2015-03-05T20:04:16Z (GMT). No. of bitstreams: 0 Previous issue date: 5 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Objetivo: Investigar o acesso de mulheres negras e brancas aos exames de detecção precoce de câncer, mama e citopatológico (CP), em duas cidades no sul do Brasil. Métodos: Estudo transversal de base populacional realizado a partir da junção de duas amostras representativas de mulheres dos 20 aos 60 anos, residentes em São Leopoldo e em Pelotas, cidades localizadas no sul do Brasil. As análises foram ajustadas por renda, escolaridade, classe econômica e idade para verificar a associação entre raça/cor e o acesso ao CP e ao exame de mama. Resultados: Foram entrevistadas 2030 mulheres, das quais 327 (16,1%) eram negras e 1703 (83,9%) brancas. Houve maior percentual de mulheres negras pertencentes aos estratos mais baixos de renda, de classe econômica e de escolaridade comparados com as mulheres brancas. A probabilidade das mulheres não realizarem os exames citopatológico e de mama foi significantemente maior nas negras. A desigualdade racial no acesso aos exames de detecção precoce de câncer persistiu após con / Objective: To investigate the access of both Black and White women to cancer early detection exams, breast and pap-smear, in two cities in Southern Brazil.Methods: A population based cross-sectional study that combines two representative samples of women aged from 20 to 60 years, from São Leopoldo and Pelotas, south Brazil cities. The analyses were adjusted according to income, education, economic class and age in order to verify the association of race/color with the access to pap-smear and breast exam. Results: Out of 2030 women interviewed, 327 (16.1%) were Black and 1703 (83.9%) were White. In comparison with White women, there were higher percentages of Black women in the lower strata of income, economic class and education. The probability of not accomplishing pap-smear and breast exam was significantly higher among Black women. Racial inequalities in access to cancer early detection exams persisted after controlling for age and other socioeconomic variables. In the previous year, Black women, regardl

Introdução: A tuberculose (TB) é uma doença infectocontagiosa causada pelo Mycobacterium tuberculosis (MTb) que apresenta cerca de 80% predileção pelo acometimento pulmonar. Amostras de escarro são necessárias para identificar este microrganismo e o escarro induzido (EI) tem sido um método alternativo de obtenção destas amostras, porém tem apresentado, frequentemente, resultados negativos. A cultura, considerada padrão áureo, é mais morosa em seus resultados, portanto menos útil para guiar o diagnóstico. A reação em cadeia da polimerase (PCR) é a metodologia mais comum para o diagnóstico rápido da TB e poucos estudos avaliaram seu papel nas amostras de EI. Objetivo: Determinar acurácia diagnóstica do PCR para microbactéria no EI de pacientes com suspeita de TB pulmonar e descrever características sócio demográficas, dados clínicos, radiológicos, comorbidades e hábitos comportamentais. Métodos: Estudo prospectivo. Pacientes internados e ambulatoriais maiores de 18 anos com sintomas respiratórios sugestivos de tuberculose pulmonar (PTB) foram convidados a participar. Os sujeitos foram entrevistados utilizando-se um questionário padronizado e o EI foi coletado. Foram obtidas três amostras para baciloscopia direta e cultura. Obteve-se uma quarta amostra para o teste de PCR. Resultados: Foram avaliadas 116 amostras de escarro induzido. A sensibilidade, especificidade, valor preditivo positivo e valor preditivo negativo da PCR foram de 95,2%, 48,4%, 29,0% e 97,9%, respectivamente. A área sob a curva ROC foi de 0,72 para o teste de PCR (P <0,0001). Conclusões: Embora a especificidade da PCR possa ser subestimada, se considerarmos a PCR mais sensível do que os métodos de cultura utilizados pensaram que esses testes positivos para PCR significam falsos positivos. Os resultados de PCR devem ser sempre interpretados cuidadosamente em conjunto com informações clínicas. / Introduction: Induced sputum (IS) is an alternative method of obtaining sputum, but IS smears are frequently negative. Culture is more time-consuming in its results, and less useful to guide the diagnosis. Polymerase chain reaction (PCR) is the most common methodology for rapid diagnosis of tuberculosis and few studies evaluated its role in IS samples. Objective: The objective of this study is to determine the diagnostic yield of PCR for TB compared with culture in IS samples. Methods: Prospective study. Inpatients and outpatients > 18 years with respiratory symptoms suggestive of PTB were invited to participate. Subjects were interviewed using a standardized questionnaire, and collected IS. Three samples were obtained for AFB smear and culture. A fourth sample was obtained for PCR test. Results: A total of 116 induced sputum samples were evaluated. The sensitivity, specificity, positive predictive value, and negative predictive value of PCR were 95.2%, 48.4%, 29.0%, and 97.9%, respectively. The area under the ROC curve was 0.72 for the PCR test (P<0.0001). Conclusions: Although the PCR specificity could be underestimated, if we consider PCR to be more sensitive than the culture method used, we thought that these PCR positive tests means false-positives. PCR results should always be interpreted carefully in conjunction with clinical information.

Background Screening by cytology has been highly effective in reducing the incidence and mortality from squamous invasive cervical cancer (ICC), but the effectiveness is less established regarding non-squamous ICC and regarding women above screening ages and below 30 years of age. Cervical cancer still occurs despite the presence of an organised screening programme. A substantial proportion of screened women with ICC are reported to have had previous abnormal cytology findings. The significance of negative cytology with limited evaluation is not quite determined, the most effective management of women with low-grade abnormalities is controversial, and evaluation of long-term effect of different treatment methods is limited. Aims To identify possible areas of improvements in the prevention of cervical cancer by evaluating the effectiveness of the Swedish cervical screening programme, and by exploring risk factors for ICC in the cytological screening histories and in the management of women with abnormal cytology findings. Methods The screening histories of all ICC cases in Sweden 1999-2001 (n=1230) and of five population-based control women per case were reviewed, using data from the Swedish Cancer Registry, the national population register, the Swedish national cervical screening quality register, histopathological reports and questionnaires to clinicians. The risk of cervical cancer according to screening histories 0.5-6.5 years before cancer diagnosis was estimated as odds ratios (ORs) in logistic regression models with 95% confidence interval (CI) (Paper I). Risk related to different cytological reports was assessed in women below 67 years of age with cytology (n=572, n=3569) in Paper II. The initial follow-up of women with abnormal or unsatisfactory cytology reports (n=159, n=258) was evaluated in Paper III, and further investigation and treatment of abnormalities (n=143 cases, n=176 controls) in Paper IV. Results The cancer cases were above screening ages (31%), had not been screened according to recommendations (33%), had negative cytology (23%), or had previous positive screening tests (13%). No screening within the recommended interval increased the risk of squamous (OR 2.97, 95% CI 2.51-3.50) as well as non-squamous cancer (OR 1.59, 95% CI 1.20-2.11), and increased the risk in all ages. Negative cytology with partially obscuring factors and unsatisfactory cytology increased the risk of subsequent early stage ICC. All cytological abnormalities increased the risk of ICC, and women with glandular atypia or atypia in cells of uncertain origin carried a particularly high risk (OR 11.69, 95% CI 7.02-19.46). After a low-grade squamous abnormal smear finding, further investigation with biopsy was more effective than repeated cytology (OR 0.46, 95% CI 0.24-0.89). Lack of biopsy increased the risk in women with both low-grade and high-grade squamous abnormalities. Neither repeat cytology, nor biopsy, decreased the risk in women with glandular atypia or atypia in cells of uncertain origin. Treatment decreased the risk, even when the biopsy before treatment was negative or showed low-grade atypia only. Ablative therapy was less effective than excision and laser conisation was the most effective therapy. Conclusions Improved adherence to screening recommendations and including older women at increased risk in the programme would have significant cancer preventive gains. Women with negative cytology with limited evaluation and with unsatisfactory cytology may need further evaluation. Assessment with biopsy should be recommended for women with low-grade as well as high-grade squamous abnormalities. The diagnosing of precancer lesions and the identification of women in need of treatment warrant improvements, in particular in cases of glandular or “other” atypia in cytology. Treatment techniques need further evaluation.

Tyrimo tikslas – Įvertinti moterų motyvaciją dalyvauti gimdos kaklelio vėžio profilaktikos programoje bei šeimos gydytojo institucijos vaidmenį vykdant šią programą Šilalės rajone. Tyrimo metodika. Tyrimas buvo atliekamas vykdant 25-60 m. amžiaus moterų, besikreipiančių į šeimos gydytoją, anketinę apklausą. Apklausa atlikta aštuoniose Šilalės rajono gydymo įstaigose. Bendras tiriamųjų skaičius N=250. Rezultatai. Įvertinus moterų, besikreipiančių į šeimos gydytoją Šilalės rajone, aktyvumą dalyvaujant gimdos kaklelio vėžio profilaktikos programoje, nustatyta, kad beveik visos (88 proc.) apklausoje dalyvavusios moterys buvo bent kartą gyvenime pasitikrinusios dėl gimdos kaklelio vėžio. Aktyviau tikrinosi moterys asmeniškai informuotos šeimos gydytojo apie vykdomą gimdos kaklelio vėžio profilaktikos programą telefonu, žinančios, kad pasitikrinimas dėl gimdos kaklelio vėžio moterims nuo 25 iki 60 metų amžiau moterims yra nemokamas, manančios, kad programa yra vykdoma tinkamai bei nurodžiusios, kad šeimos gydytojo vaidmuo vykdant gimdos kaklelio vėžio profilaktikos programą yra svarbus. Tepinėlis dėl gimdos kaklelio vėžio buvo daugiau kartų paimtas moterims, kurios asmeniškai buvo informuotos šeimos gydytojo apie gimdos kaklelio vėžio profilaktikos programą, per pastaruosius 12 mėn. pas savo šeimos gydytoją lankėsi 2-ą kartą ir daugiau, savo sveikatą vertino blogai ir buvo 45-60 metų amžiaus. Beveik pusė (45 proc.) apklaustųjų dėl gimdos kaklelio vėžio bent kartą gyvenime... [toliau žr. visą tekstą] / Aim of the study. To evaluate the motivation of women to participate in cervical cancer prevention program and the role of family physician’s in this program. Methods. Study was carried out among women, aged 25-60 years, who were seeking for family physician’s consultation. The survey was conducted in eight primary health care centers in Šilalė district. The total number of respondents was 250. Results of The Research. Almost all of the women (88%) who participated in the research were checked up for cervical cancer at least once in their life. More active women in cheek-up were those who were personally informed - by telephone, or were - informed by their family doctors, also those who knew that - the Prevention Programme of Cervical Cancer for women aged 25 – 60 is free of charge, who indicated that the role of family doctor‘s is very important in the context of this programme and that the programme is implemented properly. A smear of cervical cancer has been taken more times for women who were informed personally about the Prevention Programme of Cervical Cancer. 45% of the respondents decided to participate in this programme themselves. The main reason why women actively participate in the Prevention Programme of Cervical Cancer is the opportunity to protect themselves from the consequences of serious disease. The respondens pointed out some disadvantages of this programme: the lack of important information about the programme; insufficient public information; not... [to full text]

Abstract Malignancy Associated Changes are subtle alterations in the morphology and nuclear texture of cells in the vicinity of a malignant lesion. The phenomenon was first described in 1959, and has been the subject of considerable research in the four intervening decades, due to its potential utility to cancer screening programs. In this thesis the history of research into malignancy associated changes is reviewed, and the major findings of previous workers summarized. Original work aimed at improving the accuracy of classification of Pap smear slides is described in detail. A novel algorithm, which incorporates a genetic algorithm for feature selection and training of a neural network, is described. The algorithm was tested upon a large artificial dataset consisting of points from nested spheres in multiple dimensions. It was able to select the most discriminatory features and classify data with 99% accuracy on 80% of runs for two dimensional data, and on 90% of runs for three-dimensional data. The algorithm was also tested on two real data sets from the UCI Machine Learning Repository, the “sonar” data and the “ionosphere” data. On both of these datasets the algorithm produced a classifier using a subset of features which performed as well as previously reported classifiers using the full feature set. This algorithm was then tested on a large dataset of cell images, and its performance compared with that of the standard stepwise linear discriminant analysis approach. Both of these approaches produced similar results, which are comparable to those of previous workers in this field. Interestingly, runs of the genetic algorithm with different random number seeds tended to select different feature subsets, which produced approximately equivalent performance. This finding indicates that amongst the features used, which were selected from those previously identified in the literature as useful for MACs detection, many subsets exist which are equally discriminatory.

The objective of this study was to evaluate the root surfaces modifications after the application of different chemicals agents, and their influence on the attachment of a fibrin network and fibroblasts. From 96 anterior mandibular human incisor teeth, extracted due to severe periodontal disease, were obtained 192 dentin blocks (3x3x1 mm) of buccal and lingual surface and randomly divided into 6 groups: Control- control group, which received no treatment; Root surface scaling and root planing (SRP) - root surface was scaling and root planning with Gracey curetes; Citric acid - SRP + 30% citric acid 5 min; EDTA (ethylenediaminetetraacetic acid) - SRP + 24% EDTA gel for 1 min; Tetracycline capsule - SRP + for 3 min with a solution obtained by dissolving one 500 mg capsule of tetracycline in 2 mL of saline solution; Tetracycline gel - SRP + 50 g/mL tetracycline gel for 1 min. After dentin treatment the specimens were analyzed using 4 methodologies: 1- the demineralization level and residues of the product (n = 9); 2- the adhesion of blood components after 20 min of surface treatment (n = 9); 3- the fibroblast attachment after 24h (n = 9), were analyzed by scanning electron microscopy (SEM); and 4- the cell metabolism after 4h (n = 5) the methyltetrazolium (MTT) assay was used. Citric acid, EDTA and Tetracycline gel removed completely smear layer and smear plug on root surface, resulted in adequate demineralization .Tetracycline capsule produced great tetracycline residues with several demineralization areas on root dentin surface. Tetracycline gel and EDTA groups had more fibroblast fixation than other experimental groups. The highest mean blood clot adhesion score was observed in roots treated with a tetracycline gel, whereas, the least score was observed in roots treated with tetracycline capsule. These results demonstrated that EDTA and Tetracycline gel surface demineralization removed the smear layer over dentin surface and promoted adhesion of a fibrin network and fibroblast cells attachment. The Tetracycline capsule demonstrated less effective performance in all parameters tested. / O objetivo deste estudo foi avaliar as modificações nas superfícies radiculares após a aplicação de diferentes agentes químicos, e sua influência na inserção de rede de fibrina e fibroblastos. De 96 dentes incisivos anteriores humanos, extraídos devido doença periodontal severa, foram obtidos 192 blocos de dentina (3x3x1 mm) da superfície vestibular e lingual e aleatoriamente divididos em seis grupos: controle, que não receberam tratamento, raspagem e alisamento radicular (RAR) - superfície radicular foi raspada e alisada com curetas Gracey, Ácido cítrico - RAR + ácido cítrico 30% por 5 min; EDTA (ácido etilenodiaminotetracético) - RAR + gel de EDTA 24% por 1 min; Tetraciclina cápsula RAR + solução obtida por dissolução de uma cápsula de 500 mg de tetraciclina em 2 ml de solução salina por 3 minutos; Tetraciclina gel - RAR + 50 mg / mL de tetraciclina gel por 1 min. Após o tratamento, as amostras de dentina foram analisadas utilizando 4 metodologias diferentes: 1- o nível de desmineralização e de resíduos do produto (n = 9); 2- a adesão das componentes do sangue no tratamento de superfície após 20 min (n = 9); 3- a inserção de fibroblasto após 24 horas (n = 9), que foram analisadas por microscopia eletrônica de varredura (MEV), e 4- o metabolismo celular após 4h (n = 5), o ensaio com metiltetrazólio (MTT) foi utilizado. Ácido cítrico, EDTA e tetraciclina gel removeram completamente, smear layer e smear plug na superfície radicular, resultando em adequada desmineralização. Tetraciclina cápsula produziu grande resíduos de tetraciclina com áreas severas de desmineralização na superfície de dentina radicular. Grupos Tetraciclina gel e EDTA tiveram maior inserção de fibroblastos que os outros grupos experimentais. A maior média de adesão do coágulo sanguíneo pontuada foi observada em raízes tratadas com a tetraciclina gel, enquanto que, a menor pontuação foi observada em raízes tratadas com tetraciclina cápsula. Estes resultados demonstram que a desmineralização da superfície pelo EDTA e pela tetraciclina gel removeram a smear layer que cobria a superfície da dentina e promoveram adesão da rede de fibrina e inserção de células dos fibroblastos. A Tetraciclina cápsula demonstrou desempenho menos efetivo em todos os parâmetros testados. / Mestre em Odontologia