• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 49
  • 20
  • 5
  • 3
  • 2
  • 1
  • 1
  • Tagged with
  • 84
  • 84
  • 23
  • 15
  • 11
  • 10
  • 9
  • 6
  • 6
  • 5
  • 5
  • 5
  • 4
  • 4
  • 4
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

A diagnostic method for oral cancer screening in a Brazilian population. A pilot study

Nordström, Niklas, Werner, Mathilda January 2014 (has links)
Inledning:Oral cancer är ett allvarligt tillstånd med hög dödlighet, särskilt vid sen diagnostisering. Brasilien är ett av de länder i världen som har högst prevalens och dödlighet i oral cancer och det är den femte vanligaste cancerformen I landet. Ett hjälpmedel för tidig diagnostisering är önskvärd.Syfte:Att utvärdera skillnaden i diagnostisk tillförlitlighet mellan konventionell oral undersökning och användning av multispektralt ljus (Identafi®) som en metod för tidig upptäckt av potentiellt maligna och maligna lesioner i munslemhinnan i en brasiliansk befolkning.Material och metod:Screening av en befolkning med förhöjd risk för att utveckla oral cancer i Goiânia, Goiás, Brasilien, för att upptäcka potentiellt maligna (PML) eller maligna lesioner (ML). Patienter med misstänkta PML eller ML upptäckta under screeningen undersöktes med multispektralt ljus (Identafi®). Tre oberoende observatörer genomförde bedömning med Identafi® och slutgiltig beslut avseende PML/ML togs i konsensus. Biopsier användes som diagnostisk referensstandard. Interobservatörs överensstämmelse beräknades som procentuell överensstämmelse och kappa-värde (κ).Resultat:Undersökning med Identafi® genererade tolv biopsier. Resultaten blev tre sant positiva, fem falskt positiva, två sant negativa och noll falskt negativa. Sensitiviteten beräknades till 0,29. Specificiteten var inte möjlig att beräkna, då det inte fanns några falska negativa resultat. Interobservatörs överensstämmelse för par av observatörer varierade mellan 78-86% och κ-värden mellan 0,46-0,60.Slutsats:Slutsatsen är att multispektralt ljus, Identafi® inte har inga fördelar jämfört med konventionell klinisk undersökning i fråga om diagnostisk träffsäkerhet för PML eller ML. Dock kan det vara till hjälp för en tandläkare eller oral kirurg som stöd i sitt beslutsfattande. Det kan också hjälpa kirurgen att ta en biopsi från det mest misstänkta delen av lesionen. Det finns inte tillräckligt publicerade studier som tyder på att Identafi® kan skilja mellan normal slemhinna och PML eller ML och denna studie bekräftar detta. Användning av Identafi® som ett hjälpmedel vid screening och undersökning för PML eller ML behöver utredas ytterligare, men baserat på denna studie kan Identafi® inte rekommenderas. / Introduction: Oral cancer is a severe condition with high mortality rate, in particular if diagnosed late. Brazil is one of the countries in the world with high prevalence and mortality from oral cancer and it is the fifth most common cancer there. An aid in early detection of oral cancer as an adjunct to health promotion is desirable.Purpose:The aim of this study was to evaluate the diagnostic accuracy of conventional oral examination and the use of multi spectral light (Identafi®) as an approach for early detection of potentially malignant or malignant lesions in the oral mucosa in a Brazilian population.Material and method:Screening of high-risk population in Goiania, Goias, Brazil, for oral potentially malignant lesions (PML) or malignant lesions (ML) as a selection phase. Patients collected from the screening were examined with multi spectral light (Identafi®) to evaluate diagnostic accuracy. Three observers independently assessed all lesions with Identafi® and the final decision if a lesion was present was taken in consensus. Inter observer agreement was calculated as overall agreement and as kappa value (κ). Biopsies were used as diagnostic reference standard.Results:Identafi® generated, from twelve biopsies, three true positive, five false positive, two true negative and zero false negative. Sensitivity was calculated to 0.29 and specificity was not possible to calculate since there were no false negative results.Inter observer agreement for the use of Identafi® was calculated as overall agreement and as kappa value (κ). The overall agreement for the three pairs of observers varied between 78-86% and κ-values between 0.46 and 0.60.Conclusion:The conclusion of this study is that Identafi® does not have any benefits over conventional oral examination in diagnostic accuracy for potentially malignant or malignant lesions in the oral mucosa. It might, however, be an aid for a dentists or oral surgeons that are unsure whether to take a biopsy or not. It can also aid the surgeon when taking a biopsy to take the most suspicious part of the lesion. There are not enough published evidence that Identafi® can discriminate between normal mucosa and PML or ML, and this study confirms previous results. The use of Identafi® as an aid in screening and examination for PML or ML needs further investigation.
82

Interactions entre muqueuse orale, salive et molécules de la flaveur / Interactions between oral mucosa, saliva and flavour compounds

Ployon, Sarah 05 December 2016 (has links)
Le rôle de la salive dans la perception sensorielle est de plus en plus reconnu, notamment par le biais des interactions physico-chimiques pouvant s’établir entre protéines salivaires et constituants alimentaires. Ce travail s’intéresse à la pellicule salivaire, la couche de protéines salivaires ancrées aux cellules épithéliales, et vise à caractériser les interactions pouvant s’établir d’une part entre ces protéines et épithélium oral, et d‘autre part entre ces protéines et les molécules de la flaveur. Pour cela, un modèle in vitro de muqueuse orale a été développé. Une lignée cellulaire stable (TR146/MUC1) a été obtenue par transfection de la lignée cellulaire TR146 de manière à exprimer la mucine membranaire MUC1. Afin de former une pellicule salivaire, les cellules confluentes ont été incubées avec de la salive humaine. La rétention des mucines salivaires MUC5B par les cellules TR146/MUC1 est augmentée par rapport aux TR146, apportant ainsi un argument en faveur de l’implication de MUC1 dans l’ancrage des MUC5B aux cellules épithéliales. Le modèle développé a été appliqué à l’étude des interactions entre la muqueuse orale et les molécules d’arôme et les tanins. L’analyse des coefficients de partage par GC-FID a mis en évidence 1- l’importance de l’hydratation de la muqueuse sur la libération des composés les plus hydrophiles, 2- la capacité des cellules à métaboliser certaines molécules d’arôme, 3- l’absence d’effet de la pellicule sur la libération des molécules d’arôme à l’équilibre. En revanche, l’analyse par PTR-MS a révélé un effet de la muqueuse et de la pellicule sur la cinétique de libération des molécules d’arôme. Les interactions entre les protéines de la pellicule salivaire et les tanins modifient les caractéristiques structurales de la pellicule, en particulier le tapissage des cellules par les MUC5B. Les possibles implications sensorielles, respectivement dans les phénomènes de persistance aromatique et d’astringence, sont discutées. / The role of saliva in food sensory perception is increasingly recognized, especially through physicochemical interactions occurring between salivary proteins and food components. This work focuses on the mucosal pellicle, a layer of salivary proteins anchored onto epithelial cells, and aims at characterizing interactions that may occur between the proteins of the mucosal pellicle and flavour compounds. For that purpose, an in vitro model of oral mucosa was developed. A stable cell line (TR146/MUC1) was obtaining by transfecting the TR146 cell line in order to express the membrane bound mucin MUC1. In order to form a salivary pellicle, confluent cells were incubated with human saliva. A higher retention of salivary MUC5B by TR146/MUC1 cells was observed compared to TR146 cells, emphasising the involvement of MUC1 in MUC5B anchoring to epithelial cells. The model was applied to the investigation of interactions between the oral mucosa and aroma molecules and tannins. Measurements of partition coefficients by GC-FID revealed 1- the role of hydration of the mucosa on the release of the most hydrophilic compounds, 2- the ability of cells to metabolize some aroma compounds, 3- the absence of effect of the mucosal pellicle itself on aroma release at the thermodynamic equilibrium. Oppositely, analyses by PTR-MS evidenced an effect of the mucosa and of the pellicle on aroma release kinetic. Interactions between proteins of the mucosal pellicle and tannins modified structural characteristics of the pellicle, especially the coating of cells by salivary MUC5B. Sensory relevance for the phenomena of aroma persistence and astringency, respectively, are discussed.
83

Express?o imuno-histoqu?mica das integrinas ?2?1, ?3?1, e ?5?1, em mucosa oral normal, hiperplasia fibroepitelial inflamat?ria oral e displasia epitelial oral

Gord?n N??ez, Manuel Antonio 18 August 2006 (has links)
Made available in DSpace on 2014-12-17T15:32:31Z (GMT). No. of bitstreams: 1 ManoelAGN_tese.pdf: 5283581 bytes, checksum: 65511a1dd2487deff44e8db44d2a0cf5 (MD5) Previous issue date: 2006-08-18 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The objective of this study was perform by the streptoavidin-biotin technique an immunohistochemical analysis of ?2?1, ?3?1e ?5?1 integrins in 11 normal oral mucosa (NOM), 16 oral inflammatory fibroepithelial hyperplasia (OIFH) and 25 oral epithelial dysplasia (OED) (16 mild, 2 moderates and 7 severe), to determine if exists qualitative alteration in the expression of these integrins and if this guard relation with the oral epithelial modifications. It was observed that for the ?2?1 integrin the majority of the sample showed a predominantly intense labeling diffusely distributed in the intercellular contacts and the cytoplasm of cells of the basal and suprabasal layers, without difference of this profile between the different types of specimens, however with a trend to weak or loss of expression in 21.1% of the OEDs, being all the specimens that had not expressed this heterodimer, severe OEDs. For the ?3?1 integrin the majority of the sample showed a weak or absent labeling in basal layer. The ?5?1 integrin showed a predominant strong diffuse labeling in the intercellular contacts and cytoplasm in the suprabasal layer, with difference only in the labeling intensity between the types of specimens, inhabiting this difference in the OEDs, where 12 (48%) specimens had shown a weak labeling. It was concluded that the evaluated integrins can be involved in the cell-cell, cell-ECM interactions modulating the cellular differentiation and maintenance of the epithelial structural arrangement. The variable expression of the ?5?1 integrin in the OEDs, could suggest, respectively, a role of this molecule in the cellular survival, with intention to perpetuate the modified phenotype in these lesions, or a suppressor role on the modified phenotype due to lack of interaction of this molecule with the fibronectina of the MEC / Este estudo se prop?s analisar atrav?s da t?cnica da estreptoavidina-biotina a express?o imuno-histoqu?mica das integrinas ?2?1, ?3?1e ?5?1 em 11 esp?cimes de mucosa oral normal (MON), 16 de hiperplasia fibroepitelial inflamat?ria oral (HFIO) e 25 de displasia epitelial oral (DEO) (16 leves, 2 moderadas e 7 graves), procurando determinar se existe altera??o qualitativa na express?o destas integrinas e se a mesma guarda rela??o com as modifica??es sofridas pelo epit?lio oral. Para a integrina ?2?1 a maioria dos esp?cimes exibiu uma marca??o predominantemente intensa e difusa nos contatos intercelulares e no citoplasma celular das camadas basal e suprabasal, sem diferen?a desse perfil entre os diferentes tipos de esp?cimes, por?m com uma tend?ncia a fraca ou perda da express?o em 21.1% das DEOs, sendo todos os esp?cimes que n?o expressaram marca??o para este heterod?mero DEOs graves. Para a integrina ?3?1 a maioria da amostra exibiu uma marca??o fraca ou ausente predominantemente em camada basal. A integrina ?5?1 exibiu uma forte marca??o difusa nos contatos intercelulares e citoplasm?tica na camada suprabasal, com diferen?a apenas na intensidade de marca??o entre os tipos de esp?cimes, residindo essa diferen?a nas DEOs, onde 12 (48%) esp?cimes exibiram uma fraca marca??o. Concluiu-se que as integrinas avaliadas podem estar envolvidas nas intera??es c?lula-c?lula e c?lula-MEC que garantem a diferencia??o celular e manuten??o do arranjo estrutural tecidual. A vari?vel express?o da integrina ?5?1 nas DEOs, poderia sugerir, respectivamente, um papel dessa mol?cula na sobrevida celular, com o intuito de perpetuar o fen?tipo alterado nessas les?es, ou uma a??o supressora desse fen?tipo devido ? falta de intera??o desta mol?cula com a fibronectina da MEC
84

3D handheld endoscope for optical coherence tomography of the human oral mucosa in vivo

Walther, Julia, Schnabel, Christian, Ebert, Nadja, Baumann, Michael, Koch, Edmund 06 September 2019 (has links)
The early non-invasive diagnosis of epithelial tissue alterations in daily clinical routine is still challenging. Since optical coherence tomography (OCT) shows the potential to differentiate between benign and malignant tissue of primal endothelium, OCT could be beneficial for the early diagnosis of malignancies in routine health checks. In this research, a new handheld endoscopic scanning unit was designed and connected to a spectral domain OCT system of our workgroup for the in vivo imaging of the human oral mucosa.

Page generated in 0.0437 seconds