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  • 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.
51

Noninvasive Vascular Characterization with Low-cost, Label-free Optical Spectroscopy and Dark Field Microscopy Enables Head and Neck Cancer Diagnosis and Prognosis

Hu, Fang-Yao January 2016 (has links)
<p>Worldwide, head and neck squamous cell cancers (HNSCC) account for over 375,000 deaths annually. The majority of these cancers arise in the outermost squamous cells which progress through a series of precancerous changes before developing into invasive HNSCC. It is widely accepted that prognosis is strongly correlated to the stage of diagnosis, with early detection more than doubling the patient’s chance of survival. Currently, however, 60% of HNSCCs are diagnosed when they have already progressed to stage 3 or stage 4 disease. The current diagnostic method of visual examination often fails to recognize early indicators of HNSCC, thereby missing an important prevention window.</p><p> </p><p>Determination of cancer from non-malignant tissues is dependent on pathological examination of lesion biopsies. Thus, all patients with any clinically suspicious lesions undergo surgical biopsies. Furthermore, these surgical biopsies carry risks. In addition to the risk of general anesthesia for patients undergoing panedoscopy, some patients have poor healing and develop ulcerations or infections as a result of surgical biopsy at any anatomical site. Additionally, studies have shown that approximately 50% of suspected biopsies are later pathologically confirmed normal. An enormous amount of labor, facility, and monetary resources are expended on non-malignant biopsies and patients who ultimately have no malignancy. It would be of immense overall benefit to clinicians and patients to have a non-invasive and portable technique that could rapidly identify those patients that would benefit from further surgical biopsy from those that only need follow-up clinical observations.</p><p> </p><p>Once carcinoma is confirmed in a patient, treatment currently involves modalities of surgery, radiation, and chemotherapy. Radiotherapy plays a significant role, particularly in the management of localized HNSCC, because it is a non-invasive and function-preserving modality. However, the effectiveness of radiotherapy is limited by hypoxia. Previous studies showed that tumors reoxygenated during radiotherapy treatment may have a better prognosis. Despite decades of work, there is still no reliable, cost-effective way for measuring tumor hypoxia over multiple time points to estimate the prognosis. </p><p>To address these unmet clinical needs, three aims were proposed. The first aim was to improve early detection by identifying biomarkers of early pre-cancer as well as developing an objective algorithm to detect early disease. Neovasculature is an important biomarker for early cancer diagnosis. Even before the development of a clinically detectable lesion, the tumor vasculature undergoes structural and morphological changes in response to oncogenic signaling pathways [8]. Without receiving a sufficient supply of oxygen and nutrients to proliferate, early tumor growth is limited to only 1-2 mm. High-resolution optical imaging is well suited to characterize the earliest neovascularization changes that accompany neoplasia owing to its sensitivity to hemoglobin absorption and resolution to visualize capillary level architecture. Dark field microscopy is a low-cost and robust method to image the neovasculature. We imaged neovascularization in vivo in a spontaneous hamster oral mucosa carcinogen model using a label-free, reflected-light spectral dark field microscope. Hamsters’ cheek pouches were painted with 7, 12-Dimethylbenz[a]anthracene (DMBA) to induce precancerous to cancerous changes, or mineral oil as control. Spectral dark field images were obtained during carcinogenesis and in control oral mucosa, and quantitative vascular features were computed. Vascular tortuosity increased significantly in oral mucosa diagnosed as hyperplasia, dysplasia and squamous cell carcinoma (SCC) compared to normal. Vascular diameter and area fraction decreased significantly in dysplasia and SCC compared to normal. The areas under the receiver operative characteristic (ROC) curves (AUC) computed using a Support Vector Machine (SVM) were 0.95 and 0.84 for identifying SCC or dysplasia, respectively, vs. normal and hyperplasia oral mucosa combined. To improve AUCs for identifying dysplasia, quantitative vascular features were computed again after the vessels were split into large and small vessels based on diameter. The large vessels preserved the same significant trends, while small vessels demonstrated the opposite trends. Significant increases in diameter and decreases in area fraction were observed in SCC and dysplasia. The AUCs were improved to 0.99 and 0.92 for identifying SCC and dysplasia. These results suggest that dark field vascular imaging is a promising tool for pre-cancer detection.</p><p>Optical imaging can also be applied to quantifying other important characteristics of solid tumors in head and neck cancer (HNC), such as hypoxia, abnormal vascularity and cell proliferation. Diffuse reflectance spectroscopy is a simple and robust method to measure tissue oxygenation, vascularity and cell density. It is particularly suitable for applications in the operation room because of its compact design and portability. In addition, a fiber probe-based system is ideal for obtaining measurements at suspicious lesions in the head and neck area during surgery. Thus, my second aim was to reduce the number of unnecessary HNSCC biopsies by developing a robust tool and rapid analysis method appropriate for clinical settings. We propose the use of morphological optical biomarkers for rapid detection of human HNSCC by leveraging the underlying tissue characteristics in the aerodigestive tracts Prior to biopsy, diffuse reflectance spectra were obtained from malignant and contra-lateral non-malignant tissues of 57 patients undergoing panendoscopy. Oxygen saturation (SO2), total hemoglobin concentration ([THb]), and the reduced scattering coefficient were extracted using an inverse Monte Carlo (MC) method previously developed by former student in our lab. Differences in malignant and non-malignant tissues were examined based on two different groupings: by anatomical site and by morphological tissue type. Measurements were acquired from 252 sites, 51 of which were pathologically classified as SCC. Optical biomarkers exhibited statistical differences between malignant and non-malignant samples. Contrast was enhanced when parsing tissues by morphological classification rather than by anatomical subtype for unpaired comparisons. Corresponding linear discriminant models using multiple optical biomarkers showed improved predictive ability when accounting for morphological classification, particularly in node-positive lesions. The false-positive rate was retrospectively found to decrease by 34.2% in morphologically- vs. anatomically-derived predictive models. In glottic tissue, the surgeon exhibited a false-positive rate of 45.7% while the device showed a lower false-positive rate of only 12.4%. Additionally, comparisons of optical parameters were made to further understand the physiology of tumor staging and potential causes of high surgeon false-positive rates. Optical spectroscopy is a user-friendly, non-invasive tool capable of providing quantitative information to discriminate malignant from non-malignant head and neck tissues. Predictive models demonstrated promising results for diagnostics. Furthermore, the strategy described appears to be well suited to reduce the clinical false-positive rate.</p><p>To further improve the speed for extracting the tissue oxygenation and [THb] to reduce the time when patients were under anesthesia, the third aim was to develop a rapid heuristic ratiometric analysis for estimating tissue [THb] and SO2 from measured tissue diffuse reflectance spectra. The analysis was validated in tissue-mimicking phantoms and applied to clinical measurements in head and neck, cervical and breast tissues. The analysis works in two steps. First, a linear equation that translates the ratio of the diffuse reflectance spectra at 584 nm to 545 nm to estimate the tissue [THb] using a Monte carlo (MC)-based lookup table was developed. This equation is independent of tissue scattering and oxygen saturation. Second, SO2 was estimated using non-linear logistic equations that translate the ratio of the diffuse reflectance spectra at 539 nm to 545 nm into the tissue SO2. Correlations coefficients of 0.89 (0.86), 0.77 (0.71) and 0.69 (0.43) were obtained for the tissue hemoglobin concentration (oxygen saturation) values extracted using the full spectral MC and the ratiometric analysis, for clinical measurements in head and neck, breast and cervical tissues, respectively. The ratiometric analysis was more than 4000 times faster than the inverse MC analysis for estimating tissue [THb] and SO2 in simulated phantom experiments. In addition, the discriminatory power of the two analyses was similar. These results show the potential of such empirical tools to rapidly estimate tissue hemoglobin and oxygenation for real-time applications.</p><p>In addition to its use as a diagnostic marker for various cancers, tissue oxygenation is believed to play a role in the success of cancer therapies, particularly radiotherapy. However, since little effort has been made to develop tools to exploit this relationship, the fourth aim was to estimate patient prognosis by measuring tumor hypoxia over multiple time points so physicians are able to develop more informed and effective clinical treatment plan. To test if oxygenation kinetics correlates with the likelihood for local tumor control following fractionated radiotherapy, we again used diffuse reflectance spectroscopy to noninvasively measure tumor vascular oxygenation and [THb] associated with radiotherapy of 5 daily fractions (7.5, 9 or 13.5 Gy/day) in FaDu xenografts. Spectroscopy measurements were obtained immediately before each daily radiation fraction and during the week after radiotherapy. SO2 and [THb] were computed using an inverse MC model. Oxygenation kinetics during and after radiotherapy, but before a change in tumor volume, was associated with local tumor control. Locally controlled tumors exhibited significantly faster increases in oxygenation after radiotherapy (days 12-15) compared with tumors that recurred locally. (2) Within the group of tumors that recurred, faster increases in oxygenation during radiotherapy (days 3-5) were correlated with earlier recurrence times. An AUC of 0.74 was achieved when classifying the local control tumors from all irradiated tumors using the oxygen kinetics with a logistic regression model. (3) The rate of increase in oxygenation was radiation dose dependent. Radiation doses ≤9.5 Gy/day did not initiate an increase in oxygenation whereas 13.5 Gy/day triggered significant increases in oxygenation during and after radiotherapy. Additional confirmation is required in other tumor models, but these results suggest that monitoring tumor oxygenation kinetics could aid in the prediction of local tumor control after radiotherapy.</p><p>Angiogenesis is a highly regulated process to support tissue growth. Neovasculature is designed by nature to grow toward areas lacking nutrition and oxygen. Cancer cells proliferate too quickly to have their nutritional and oxygen needs completely satisfied, which results in an imbalanced state of angiogenesis leading to tortuous blood vessels, hypoxic tissues and radioresistance. We characterized the tumor-induced vascular features with simple, robust and low-cost dark field microscopy and spectroscopy to enable early cancer diagnosis, improvement of surgical biopsy accuracy and better predict the prognosis of radiotherapy for HNC. Our results demonstrated that these noninvasively measured, label-free vascular features are able to detect pre-cancer, reduce unnecessary surgical biopsies and predict prognosis of radiotherapy.</p> / Dissertation
52

Genetic Differentiation of oral and oropharyngeal carcinoma based on Human Papillomavirus Status and Race

Vashist, Aastha 07 December 2016 (has links)
INTRODUCTION: Head and neck cancer is one of the most common malignancy in the world. While it has been associated with several factors like alcohol consumption and smoking, there is approximately 25% of head and neck cancer that can be attributed to Human Papillomavirus (HPV) especially HPV 16. HPV associated cancer has been associated with a better prognosis as compared to HPV negative cancers. It has also been shown in previous studies that HPV-negative African Americans have a higher mortality rate as compared to HPV associated cancers in European Americans and HPV-negative European Americans patients. The three states of HPV associated cancers have been compared, which included HPV active, HPV inactive and HPV negative. AIM: The study aims include: 1) Compare the differences in the gene expression profiles of HPV negative HNSCC in AA from EA patients, and determine the differences in their biological make up. 2) Explore and compare the genetic expression profiles of HPV-active, HPV-inactive and HPV-negative head and neck cancer patients. METHODS: A secondary data analysis was conducted on 36 oropharyngeal cancer tissues samples with different HPV status (HPV-active, HPV-inactive and HPV- negative). ANOVA was conducted in R to compare all the three groups from each other and identify the genes that were differentially expressed. Bayes Moderated paired t-test was used to compare two groups of HPV-negative European Americans with HPV-negative African Americans. RESULTS: Our analysis revealed that the genes that were differentially expressed in HPV- active and HPV-negative analysis were different from HPV-active and HPV-inactive analysis. Our analysis also identified genes that were differentially expressed in African Americans as compared to European Americans. DISCUSSION: This study provides the genetic expression profiles in different groups (European Americans and African Americans) based on different HPV stages. Despite the small sample size of our data, we were able to identify the genes that were differentially expressed amongst different conditions in patients who had oropharyngeal carcinoma. We were also able to identify the genes involved in HPV-negative oral cancer comparing the African Americans to the European Americans.
53

PET/MRT in der onkologischen Diagnostik mit dem Schwerpunkt Kopf-Hals-Tumoren

Stumpp, Patrick 30 November 2016 (has links) (PDF)
Erst seit 2010 sind kombinierte Positronenemissionstomographie- Magnetresonanztomographie-Geräte (PET/MRT) zur hybriden Bildgebung verfügbar. Die mit der Entwicklung der Geräte verbundenen Hoffnungen bezüglich der onkologischen Diagnostik lagen zunächst auf einer verbesserten Genauigkeit in der Tumordetektion im Vergleich zur PET/CT. Rasch wurde jedoch deutlich, dass insbesondere die Möglichkeit der non-invasiven, multiparametrischen Charakterisierung von Tumorerkrankungen einen wesentlichen Vorteil der PET/MRT gegenüber der PET/CT darstellt. Der im Universitätsklinikum Leipzig AöR 2011 installierte PET/MRT-Scanner war einer der ersten weltweit und in dieser Habilitationsschrift sind die ersten Erfahrungen mit dieser Methode auf dem Gebiet der onkologischen Diagnostik zusammengefasst. Schwerpunkt ist dabei die Diagnostik von Kopf-Hals-Tumoren, da in diesem Bereich die CT aufgrund des im Vergleich zur MRT schlechteren Weichteilkontrastes Einschränkungen aufweist. In dieser Schrift werden zunächst die unterschiedlichen Konzepte im Gerätedesign der PET/MRT und die Besonderheiten der PET/MRT im Vergleich zur PET/CT erläutert. Auch die kritischen Punkte, die bei der Implementierung eines PET/MRT-Scanners zu beachten sind, werden detailliert dargestellt. Hierbei werden besonders die baulichen und organisatorischen Aspekte berücksichtigt, es werden aber auch Hinweise zur Qualitätskontrolle und zur Entwicklung von Untersuchungsprotokollen gegeben. In der ersten klinischen Studie zur Anwendung der PET/MRT mit 18F-Fluorodesoxyglucose (18F-FDG) bei Patienten mit Kopf-Hals-Tumoren konnten wir hinsichtlich Sensitivität und Spezifität noch keine Unterschiede zur PET/CT nachweisen. Allerdings war hier die untersuchte Patientengruppe heterogen und enthielt sowohl Primär- als auch Rezidivtumore. Aktuell konzentriert sich die onkologische Forschung am PET/MRT auf die Möglichkeiten der multiparametrischen Bildgebung zur Detektion und vor allem Charakterisierung von Tumorerkrankungen. Hier konnten wir signifikante Korrelationen von Glukosestoffwechsel und verschiedenen Perfusionsparametern bei Patienten mit Kopf-Hals-Tumoren nachweisen. Bei Patientinnen mit Zervixkarzinom konnte ein inverser Zusammenhang zwischen Glukosestoffwechsel und Diffusionsrestriktion nachgewiesen werden. Die letzte aufgeführte Arbeit zeigt die Korrelationen zwischen der bildgebenden Tumorcharakterisierung und histopathologischen Ergebnissen bei Kopf-Hals-Tumoren, wo wir Zusammenhänge von Kernfläche und dem Proliferationsmarker Ki-67 mit Diffusionseigenschaften bzw. Glukosestoffwechsel im Tumorgewebe nachweisen konnten.
54

Cytoprotective versus Non-protective Autophagy Induced by Radiation in Head and Neck Cancer Cells

Bakhshwin, Duaa 28 April 2014 (has links)
The primary treatment options for head and neck cancer are radiation therapy or surgery, or both combined; chemotherapy is often used as an additional, or adjuvant, treatment. Patients treated with radiotherapy are exposed to a high cumulative dose of radiation over a period of time and there is a 17-33% chance of recurrence. High cumulative doses of radiation, a long time course of treatment, side effects and the possibility of recurrence provide the rationale for developing approaches for radiation sensitization, which could be helpful to patients in decreasing the dose, duration of radiation, side effects, or the chance of recurrence. Radiation induces autophagy, which is a catabolic process involving the degradation of the cell’s own components to generate energy under conditions of stress. Autophagy can be cytoprotective helping the cell to survive during stress such as nutrient deprivation or it can be cytotoxic, leading the cell toward death. We investigated whether blocking autophagy by the use of the antimalarial drug, chloroquine, could sensitize head and neck cancer cells to radiation. Studies were performed using the HN30 human head and neck cancer line (p53 wild type) derived from the pharynx as well as HN6 human cells (p53 mutant) derived from the base of the tongue. Cell viability was determined by cell counting and clonogenic survival assays, autophagy was monitored based on acridine orange staining accompanied by flow cytometry, while western blotting, DAPI and TUNEL staining and PI/annexin/FACS were utilized for determination and quantification of apoptosis. Senescence was monitored by beta-galactosidase staining/ FACS analysis. Radiation alone produced a transient growth arrest followed by proliferative recovery in both the HN30 and HN6 cancer cells. Radiation also promoted autophagy in both cell lines. The combination of chloroquine with radiation inhibited autophagy and promoted apoptotic cell death and suppression of proliferative recovery for the HN30 cells, but had little effect on sensitivity to radiation and proliferative recovery in the HN6 cells. The data suggest that autophagy induced by radiation serves a protective function in the HN30 cells and that a blockade to autophagy by chloroquine drives the cell toward apoptosis and death. In contrast, autophagy in HN6 cells appears to be non-protective as a pharmacological blockade did not sensitize the HN6 cells to radiation. These studies support the premise that autophagy induction by radiation need not necessarily have a cytoprotective function and further indicates that caution should be exercised in efforts to sensitize head and neck cancer to radiation through the clinical suppression of autophagy.
55

Effects of CXCL8 Overexpression on Tumor Cell Proliferation and Migration in an HNSCC Cell Model

Christofakis, Emil Paul 01 January 2007 (has links)
Head and neck squamous cell carcinoma is the 6th most common malignancyworldwide. Recently, a link between cancer and inflammation has been found. Mediatingthis relationship are the chemotactic cytokines known as chemokines. CXCL8 (Interleukin-8), a CXC ELR+ Chemokine mainly responsible for neutrophil chemoattraction, has beenimplicated in increased tumor proliferation, migration and angiogenesis. The current studytests the effects of CXCL8 on the tumor proliferation and metastasis. By genetically modifying cells to knockdown or overexpress the CXCL8 gene we tested its biological rolein head and neck cancer progression. Overexpression of CXCL8 in HN4 tumor cells withlow endogenous CXCL8 levels was found to increase tumor growth, as judged by cellcounting and MTT assays. Conversely, RNAi-mediated knockdown of CXCL8 expressionin HN12 cells, which express high levels of this chemokine, resulted in a decrease inproliferation. Similarly, overexpression of CXCL8 enhanced migration of HN4 cells invitro, while knockdown inhibited HN12 cell migration and invasion through a basementmembrane substitute. Taken together, these findings support the hypothesis that CXCL8affects multiple processes involved in head and neck cancer tumor progression. The datasuggest that CXCL8 is a potential therapeutic target for head and neck, and other, cancers.
56

Análise do secretoma de carcinoma de cabeça e pescoço e de seu efeito no microambiente tumoral / Analysis of the head and neck carcinoma secretome and its effect on the tumor microenvironment

Cunha, Bianca Rodrigues da 12 May 2017 (has links)
Ao longo dos últimos anos, tornou-se evidente que o início e a progressão do câncer dependem de vários componentes do microambiente tumoral, incluindo células imunes e inflamatórias, fibroblastos, células endoteliais, adipócitos e matriz extracelular. Estes componentes e as células neoplásicas interagem entre si e trocam sinais pró e antitumor. O presente estudo teve como objetivo analisar o secretoma de células neoplásicas sob estresse e seu efeito no microambiente tumoral. Para este fim, duas linhagens celulares de carcinoma epidermóide de cabeça e pescoço foram cultivadas em duas condições de estresse: hipóxia e radiação. Os meios condicionados por estas células (secretoma 1) e o seu controle foram utilizados para cultivar células neoplásicas e fibroblastos humanos normais da cavidade oral. Os resultados sugerem que os sinais derivados das células neoplásicas em resposta a estresse dirigem a expressão gênica e proteica, bem como o comportamento celular das células vizinhas. Foram identificadas 38 proteínas celulares e nove proteínas secretadas com expressão aumentada e 61 proteínas celulares e 70 secretadas com expressão reduzida em células neoplásicas sob estresse hipóxico. Também foram identificadas 59 proteínas celulares e 29 proteínas secretadas com expressão aumentada e 59 proteínas celulares e 19 secretadas com expressão reduzida em células neoplásicas e fibroblastos humanos normais tratados com o meio condicionado por células sob estresse hipóxico. O secretome de células sob estresse não foi capaz de induzir proliferação de células neoplásicas e fibroblastos humanos normais, mas promoveu migração e invasão. Os resultados podem contribuir para o melhor entendimento do efeito dos fatores parácrinos liberados pelas células neoplásicas sobre a expressão gênica, bem como sobre o comportamento das células tumorais e estromais / Over the past years, it has become evident that cancer initiation and progression depends on several components of the tumor microenvironment, including inflammatory and immune cells, fibroblasts, endothelial cells, adipocytes, and extracellular matrix. These components and the neoplastic cells interact with each other providing pro and antitumor signals. The present study aimed to analyze the secretome of cancer cells under stress and their effect on the tumor microenvironment. For this purpose, two cell lines from head and neck carcinomas were cultured in two stress conditions - hypoxia and radiation. The medium conditioned by these cells (secretome 1) and their control were used to grow untreated neoplastic cells and normal human fibroblasts from oral cavity. Our results showed that signals derived from cancer cells in response to stress drive gene and protein expression and cell behavior. Thirty-eight overexpressed cellular and 9 secreted proteins, and 61 underexpressed cellular and 70 secreted proteins were identified in neoplastic cells under hypoxic stress. Fifty-nine overexpressed cellular and 29 secreted proteins, and 59 underexpressed cellular and 19 secreted proteins were identified in neoplastic cells and normal human fibroblasts treated with the medium conditioned by cells under hypoxic stress. The secretome of cells under stress was not able to induce proliferation of cancer cells and normal human fibroblasts, but promoted migration and invasion. The results may contribute to understand the effect of paracrine factors released by neoplastic cell on gene expression as well as on stromal and tumor cells behavior
57

Avaliação dos parâmetros de halitose e sialometria em pacientes submetidos à radioterapia de cabeça e pescoço / Evaluation of oral halitosis parameters in patients submitted to the head and neck radiotherapy

Albuquerque, Danielle Frota de 27 April 2007 (has links)
O objetivo deste estudo foi investigar as relações entre os parâmetros de halitose e sialometria em pacientes submetidos à radioterapia de cabeça e pescoço, avaliando a presença de saburra, classificada em termos de peso seco, fluxo salivar, teste BANA e halimetria oral e comparar os resultados entre os grupos. Foram examinados 48 pacientes divididos em três grupos. O grupo 1 (\"saúde\") foi constituído de pacientes que haviam terminado o tratamento na Faculdade de Odontologia de Bauru (FOB), sem queixa de halitose e com íntegra saúde oral; o grupo 2 (\"N. O.\") por indivíduos com necessidades odontológicas e o grupo 3 (\"radio\") pacientes que haviam sido submetidos à radioterapia na região de cabeça e pescoço. Foram avaliadas as concentrações bucal de Compostos Sulfurados Voláteis (CSVs) através do monitor portátil de sulfetos HalimeterTM, os valores relacionados à taxa de fluxo salivar em repouso e estimulado, teste BANA com material proveniente da saburra lingual e peso seco da mesma. Os resultados foram analisados utilizando o teste de análise de variância que quantificaram o hálito antes e após a remoção da saburra. As relações entre halimetria bucal, peso seco da saburra, fluxo salivar com e sem estímulo, e a relação entre fluxo salivar em repouso e estimulado foram feitas através do teste de correlação de Pearson. Para verificar correlações entre halimetria bucal inicial e teste BANATM foi utilizado o teste \"t\" de Student. Os resultados mostraram que houve diferença estatisticamente significante entre a halimetria oral nos grupo \"saúde\" e \"radio\" e, nos grupos \"saúde\" e \"N.O.\" Pode-se observar também que houve relação entre a presença de saburra e os níveis de CSVs. Em relação ao fluxo salivar, foi observada uma redução estatisticamente significante entre o grupo \"radio\" e os outros dois. Nas condições dessa pesquisa, foi constatado que a halitose pode ser considerada um efeito adverso da radioterapia, vinculada à hipossalivação e saúde oral deficiente. / The aim of this study was to verify the halitosis parameters in patients who had received head and neck radiotherapy. The degree of halitosis was determined through the presence of tongue coating, classified according to its dry weight; the salivary flow rate, the BANATM test and HalimeterTM oral measurements. A total of 48 subjects were examined, which were divided into three groups. Group 1 was consisted for patients with good oral health and no complains of bad breath; Group 2 consisted of patients with bad oral health condition and Group 3 comprised individuals who had received head and neck radiotherapy. The concentration of Volatile Sulfur Compounds (VSC) was assessed by means of a portable sulfide monitor (HalimeterTM) and the values were correlated to the resting and stimulated salivary flow rate and to the BANATM test with material collected from the tongue coating and its dry weight. Halitosis was quantified before and after the removal of the tongue coating and the data was analyzed by means of the ANOVA test. The correlation among salivary flow rate, weight of the tongue coating and HalimeterTM oral measurements was evaluated by the Pearson test. The results showed a statistically significant difference between group 1 and 3, and between groups 1 and 2. A relationship between the presence of tongue coating and the VSC levels was also demonstrated. In concerning to the salivary flow rate, there was a statistically significant reduction between group 1 and 3, and group 2 and 3. In the accordance of this study, halitosis can be considered a side effect of radiotherapy, tied with the hyposalivation and deficient oral health.
58

Estudo in vitro e in vivo de novos compostos: com alvo-específico (hnRNP K e SET) ou com ação na mitocôndria para uso como antitumoral em carcinoma oral ou como citoprotetor em célula não-tumoral / Studies in vitro and in vivo novel compounds: with target-specific (hnRNP K and SET) or the mitochondrion action for use as antitumor in oral carcinoma cell or as cytoprotection in non-tumor

Goto, Renata Nishida 12 September 2017 (has links)
Os avanços na compreensão da biologia das neoplasias de cabeça e pescoço têm aberto novas direções na ciência. As pesquisas estão sendo direcionadas para o desenvolvimento de terapias com alvos moleculares específicos, os quais são úteis tanto na predição dos tratamentos, quanto na seleção de pacientes que podem responder a uma determinada terapia com base nas alterações moleculares dos tumores. As proteínas hnRNP K e SET, recentemente identificadas como superexpressas em câncer de cabeça e pescoço, representam um novo e atrativo alvo terapêutico para esse tipo de câncer. As mitocôndrias também tem sido objeto de estudo, pois participam nos processos de morte celular por apoptose, e estão envolvidas na sobrevivência celular. Neste estudo avaliamos os efeitos in vitro e in vivo em carcinoma oral e em célula não-tumoral, de novos compostos com alvo-específico (hnRNP K e SET) ou com ação na mitocôndria, para aplicação tanto como antitumoral, como citoprotetor. A citotoxicidade dos compostos foi avaliada pelo método de resazurina nas linhagens tumorais de carcinoma de células escamosas de cabeça e pescoço (HN13, HN12, HN6 e CAL27). Os compostos 11 e 17, alvos específicos da proteína hnRNP K, apresentaram baixa citotoxicidade; o peptídeo OP449, alvo específico da proteína SET, e o composto YV-241, com ação na mitocôndria, apresentaram alta citotoxicidade, com valores de IC50 5,11 e 7,77 ?M, respectivamente. OP449 alterou as proteínas reguladas por SET e reduziu a proliferação das células tumorais no modelo de xenoenxerto ortotópico em camundongo BALB/ c nude; os resultados, porém, não foram significativos. A associação de OP449 com FTY720 promoveu um efeito sinérgico significativo (CID<0,7) na linhagem celular HN12 e reduziu os tumores do xenoenxerto no dorso em camundongos BALB/c nude. O composto YV-241 alterou o potencial de membrana mitocondrial das células tumorais e aumentou o número de mitocôndrias, observado por microscopia eletrônica de transmissão e por microscopia confocal, reduziu proteínas envolvidas com vias de sinalização de sobrevivência, proliferação, ciclo celular e angiogênese, e induziu apoptose com o envolvimento da mitocôndria. Além disso, o composto reduziu os tumores do modelo de xenoenxerto. O possível efeito citoprotetor do composto JM-E-H foi observado na linhagem NOK-SI, por meio da regulação da via de sinalização de HIF-1?. Portanto, OP449 + FTY720 e o composto YV-241 apresentam potencial terapêutico contra carcinoma oral, e o composto JM-E-H, potencial efeito citoprotetor / Advances in understanding the biology of head and neck cancer have opened new directions in science. Research is being directed at the development of therapies with specific molecular targets that are useful in predicting treatments or in selecting patients who may respond to a particular molecular therapy based on molecular changes of the tumors. The hnRNP K and SET proteins, recently identified as overexpressed in head and neck cancer, represent a new and attractive therapeutic target for this type of cancer. Mitochondria have also been the object of study, since they participate in the processes of cell death by apoptosis, and are involved in cell survival. In this work we evaluated the in vitro and in vivo effects in oral carcinoma and non-tumor cell of new compounds with specific target (hnRNP K and SET) or with action in mitocondria, for application either as antitumor or cytoprotectant. The cytotoxicity of the compounds was evaluated by the resazurin method in head and neck squamous cell carcinoma cell lines (HN13, HN12, HN6 and CAL27). Compounds 11 and 17, specific targets of hnRNP K protein, showed low cytotoxicity; the peptide OP449, specific target of SET protein, and compound YV-241, acting on mitochondria, showed high cytotoxicity, with IC50 values of 5.11 and 7. 77?M, respectively. OP449 altered SET-regulated proteins and decreased proliferation of tumor cells in the orthotopic xenograft model in BALB/c nude mouse. The results, however, were not significant. The association of OP449 with FTY720 caused a significant synergistic effect (CID <0.7) on HN12 cell line, and decreased the xenograft tumors. The YV-241 compound altered mitochondrial membrane potential of tumor cells and increased the number of mitochondria, observed by transmission electron microscopy and by confocal microscopy, reduced proteins involved with signaling pathways for survival, proliferation, cell cycle and angiogénesis, and induced apoptosis with the involvement of mitochondria. In addition,the compound reduced tumors of the xenograft model. The possible cytoprotective effect of the compound JM-E-H was observed in the NOK-SI lineage through the regulation of HIF-1? signaling pathway. Therefore, OP449 + FTY720 and compound YV-241 show therapeutic potential against oral carcinoma, and the compound JM-E-H, potential cytoprotective effect
59

Dosimetric Consequences of the Parotid Glands Using CT-To-CBCT Deformable Registration During IMRT For Late Stage Head And Neck Cancers

Unknown Date (has links)
Patients receiving Intensity Modulated Radiation Therapy (IMRT) for late stage head and neck (HN) cancer often experience anatomical changes due to weight loss, tumor regression, and positional changes of normal anatomy (1). As a result, the actual dose delivered may vary from the original treatment plan. The purpose of this study was (a) to evaluate the dosimetric consequences of the parotid glands during the course of treatment, and (b) to determine if there would be an optimal timeframe for replanning. Nineteen locally advanced HN cancer patients underwent definitive IMRT. Each patient received an initial computerized tomography simulation (CT-SIM) scan and weekly cone beam computerized tomography (CBCT) scans. A Deformable Image Registration (DIR) was performed between the CT-SIM and CBCT of the parotid glands and Planning Target Volumes (PTVs) using the Eclipse treatment planning system (TPS) and the Velocity deformation software. A recalculation of the dose was performed on the weekly CBCTs using the original monitor units. The parameters for evaluation of our method were: the changes in volume of the PTVs and parotid glands, the dose coverage of the PTVs, the lateral displacement in the Center of Mass (COM), the mean dose, and Normal Tissue Complication Probability (NTCP) of the parotid glands. The studies showed a reduction of the volume in the PTVs and parotids, a medial displacement in COM, and alterations of the mean dose to the parotid glands as compared to the initial plans. Differences were observed for the dose volume coverage of the PTVs and NTCP of the parotid gland values between the initial plan and our proposed method utilizing deformable registration-based dose calculations. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2015. / FAU Electronic Theses and Dissertations Collection
60

RADIOINJÚRIA ASSOCIADA AOS POLIMORFISMOS DE BASE ÚNICA DOS GENES ATM E TP53 EM PACIENTES COM CÂNCER DE CABEÇA E PESCOÇO.

Luciano, Cristiana da Costa 14 November 2012 (has links)
Made available in DSpace on 2016-08-10T10:38:45Z (GMT). No. of bitstreams: 1 Cristiana da Costa Luciano.pdf: 1987242 bytes, checksum: 2f3402c7b9c457e5f89de59897be59ea (MD5) Previous issue date: 2012-11-14 / The head and neck cancer is the fifth most common in Brazil, being the most predominant histology type the squamous cell carcinoma. Radiation therapy is a procedure for treatment with the efficacy variable, and may play an important role in controlling tumor growth. Faced with this therapy, the patient is exposed to ionizing radiation that can cause adverse effects resulting cessation of treatment. The objective was to evaluate the association of polymorphisms of TP53 and ATM genes in patients with head and neck cancer with adverse effects on normal tissues presented as a result of radiotherapy. Materials: The DNA was extracted 54 samples of peripheral blood of patients with head and neck cancer, then the fragments of TP53 and ATM were amplified and subsequently sequenced to check for any polymorphism which may be responsible for the radiosensitivity of patients. Statistical analysis was performed using the SPSS 17.0 software. Results and Discussion: In univariate analysis, patients who had experienced adverse effects RT suspended acute low and high grade with RTOG skin (p = 0.012). Those who had a family history of cancer showed higher adverse acute laryngeal RTOG TGI high (p = 0.040). The exchange C> T at position 11322 of TP53 (intron 3), the ATM and TP53 polymorphisms analyzed and the frequency of acute and chronic adverse effects were not significant (p>05). Conclusions: Based on these results is of utmost importance that alternatives are created to predict the dose to be prescribed during radiotherapy, preventing adverse effects and discontinuation of treatment and also providing better tumor control. / O câncer de cabeça e pescoço, no Brasil, é o quinto mais comum, sendo o tipo histológico mais predominante de carcinoma de células escamosas. A radioterapia é uma das modalidades de tratamento com eficácia variável, podendo desempenhar um papel importante no controle do tumor. Diante essa terapêutica, o paciente está exposto a radiações ionizantes que podem causar efeitos adversos gerando a interrupção do tratamento. O objetivo foi avaliar a associação de polimorfismos dos genes TP53 e ATM em pacientes com câncer de cabeça e pescoço com efeitos adversos sobre os tecidos normais apresentados como resultado da radioterapia. Materiais: O DNA foi extraído de 54 amostras de sangue periférico de pacientes com câncer de cabeça e pescoço, em seguida os fragmentos de TP53 e ATM foram amplificados e posteriormente sequenciados a fim de verificar se os polimorfismos poderiam estar associados à radiossensibilidade dos pacientes selecionados. A análise estatística foi realizada utilizando o software SPSS 17.0. Resultados e Discussão: Por meio de análise univariada, pacientes que tiveram a RT suspensa apresentaram efeitos adversos agudo de baixo e alto grau com RTOG de pele (p=0,012). Aqueles que tinham história familiar de câncer apresentaram maiores efeitos adversos agudo de laringe com RTOG TGI alto (p=0,040). A troca C>T na posição 11322 do gene TP53 (intron 3), os polimorfismos de TP53 e ATM analisados e a frequência de efeitos adversos agudos e crônicos não foram significativos para (p>0,05). Conclusões: Diante dos resultados obtidos é de suma importância que alternativas sejam criadas para predizer a dose a ser prescrita durante a radioterapia, prevenindo os efeitos adversos e a interrupção do tratamento e ainda, promovendo melhor controle tumoral.

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