published_or_final_version / abstract / Anatomy / Doctoral / Doctor of Philosophy

published_or_final_version / Community Medicine / Master / Master of Public Health

published_or_final_version / abstract / Surgery / Doctoral / Doctor of Philosophy

Ma, Buig Yue Brigette. / Thesis M.D. Chinese University of Hong Kong 2014. / Includes bibliographical references (leaves 232-270). / Title from PDF title page (viewed on 18, November, 2016).

Objetivo: Verificar se a rinometria acústica, usada de rotina para avaliar a patência nasal, é capaz de identificar a deficiência no movimento velar em indivíduos com diagnóstico clínico de função velofaríngea inadequada (FVI). Modelo: Estudo clínico prospectivo Local de Execução: Hospital de Referência Especializado. Participantes: Vinte indivíduos com fissura de palato reparada e FVI residual e 18 indivíduos-controle sem fissura de palato e função velofaríngea adequada (FVA), adultos, de ambos os sexos. Variáveis analisadas: Curvas área-distância foram obtidas no repouso velar e na fala (fonema /k/), utilizando um sistema Eccovision AR, sendo o volume determinado pela integração da área sob a curva em segmento correspondente à nasofaringe. A mobilidade velar (V) foi estimada pela diferença absoluta e relativa entre o volume nasofaríngeo no repouso velar (Vr) e na fala (Vk). A eficiência da técnica em discriminar FVI e FVA foi analisada pela curva ROC. Resultados: Os valores médios (±DP) de Vr e Vk obtidos foram: 23,2±3,6cm3 e 15,9±3,8cm3, no grupo FVA, e 22,7±7,9cm3 e 20,7±7,4cm3, no grupo FVI, correspondendo a uma redução média de 7,3cm3 (31%) no grupo FVA e a uma redução significativamente menor, de 2,0cm3 (9%), no grupo FVI (p<0,05). Constatou-se que 70% dos pacientes do grupo FVI apresentaram V sugestivo de elevação velar prejudicada (inferior ao limiar de corte que maximizou, simultaneamente, a sensibilidade e a especificidade do teste), confirmando o diagnóstico clínico. Conclusão: A rinometria acústica foi capaz de identificar, com bom poder discriminatório, o comprometimento da atividade velar que caracteriza a insuficiência velofaríngea. / Objective: To determine whether acoustic rhinometry, routinely used for evaluation of nasal patency, is able to identify impairment of velar movement in individuals with clinical diagnosis of inadequate velopharyngeal function (IVF). Design: Prospective clinical study. Setting: Reference Craniofacial Hospital. Participants: Twenty subjects with repaired cleft palate and residual IVF and 18 noncleft controls with adequate velopharyngeal function (AVF), adults, of both sexes. Main Outcomes Measures: Area-distance curves were obtained during velar rest and speech (phoneme /k/), using an Eccovision AR system, and volume was determined by integrating the area under the curve at a segment corresponding to nasopharynx. Velar mobility (_V) was estimated by the absolute and relative difference between nasopharyngeal volume at velar rest (Vr) and speech (Vk). The efficiency of the technique to discriminate IVF and AVF was assessed by a ROC curve. Results: Mean Vk and Vr values (±SD) obtained were: 23.2±3.6cm3 and 15.9±3.8cm3 (AVF group), and 22.7±7.9cm3 and 20.7±7.4cm3 (IVF group), corresponding to an average reduction of 7.3cm3 (31%) for the AVF group and a significantly smaller reduction of 2.0cm3 (9%) for the IVF group (p<0.05). Seventy percent of the IVF patients showed a _V suggesting impaired velar elevation (below the cutoff score that maximized both the sensitivity and specificity of the test), confirming clinical diagnosis. Conclusion: Acoustic rhinometry was able to identify, with a good discriminatory power, the impairment of velar activity which characterizes velopharyngeal insufficiency.

Abstract not available. / Pak Wai Martin. / Adviser: Charles Andrew van Hasselt. / Source: Dissertation Abstracts International, Volume: 72-10, Section: B, page: . / Thesis (M.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 245-269). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.

Deletion on the short arm of chromosome 3 is one of the most important genetic abnormalities in the tumorigenesis of nasopharyngeal carcinoma (NPC). Both physical mapping and functional studies have targeted an NPC-related tumor suppressor gene(s) to chromosome 3p21.3. Our group has previously reported that the Ras Association Domain Family 1A (RASSF1A) gene, located within a 120-kb minimal deleted region on 3p21.3, was frequently inactivated by promoter hypermethylation in NPC. These findings suggest that RASSF1A may be a critical tumor suppressor gene in NPC. In this study, the functions of RASSF1A in NPC was characterized with the following specific aims: (1) the role of RASSF1A as a tumor suppressor in NPC cells; (2) the identification of novel RASSF1A-modulated genes and pathways in NPC; (3) the effect of RASSF1A knockdown in immortalized nasopharyngeal epithelial cells; (4) the aberrant transcription and epigenetic changes of other RASSF family of genes ( RASSFS/NORE1 and RASSF4/AD037) in NPC. / In summary, RASSF1A is a major tumor suppressor gene from 3p21.3 in NPC. RASSF1A may exert its tumor suppressor function through various biochemical pathways. The novel findings from this study revealed the role of RASSF1A in the tumorigenesis of NPC. It also led to the better understanding of the molecular pathogenesis of this endemic cancer. (Abstract shortened by UMI.) / RASSF1A is a member of the RASSF family of proteins characterized by a consensus Ras-association domain at the C-terminus. The expression and methylation status of two other members of RASSF gene family, RASSF4/AD037 and RASSF5/NORE1, were investigated in NPC. The study showed that RASSF1A, but not other members of the RASSF family, is the target tumor suppressor in this particular cancer type. / Restoration of wild-type RASSF1A, by means of transfection, in a RASSF1A-deficient NPC cell line (C666-1) led to marked growth inhibition in the NPC cells. Isolated stable clones expressing RASSF1A demonstrated retarded cell proliferation in vitro . Soft-agar assay showed decreased number and sizes of colonies formed by these clones. The expression of RASSF1A in NPC cells also led to a dramatic reduction in tumorigenic potential in nude mice. The findings provide functional evidence that RASSF1A is a target tumor suppressor gene on 3p21.3 in NPC. / Chow Shuk Nga Lillian. / "May 2005." / Adviser: Kwok Wai Lo. / Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 3588. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 112-124). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract in English and Chinese. / School code: 1307.

Common amplicons were delineated throughout the NPC genome in a large panel of NPC cell lines, xenografts, and primary tumors by two high-density genomic arrays with &sim;1 Mb and 35 kb resolution. Apart from the genetic changes reported in previous studies, a number of novel chromosomal aberrations were discovered, including gains at 7p11, 16p13.3, 19p13, 19q13-q43 and 20q13. Most distinctively, common amplicons at 11q13 and 12p13 were found in this cancer. Two smallest amplification regions with 5.4 Mb and 2.16 Mb were delineated at 11q13.1-q13.3 and 12p13.31 respectively. The high prevalence of these 2 amplified regions have led to the hypothesis that activation of the target oncogenes in these regions are critical events for NPC development. / Expression of candidate genes located within 11q13.3 was examined and consistent overexpression of CCND1 in cell lines and xenografts were identified in the 11q13.3. Frequent concordant gains and overexpression of CCND1 were further confirmed in primary tumors. Knockdown of CCND1 mRNA by siRNA technique was found to inhibit cell growth and lead to cell cycle arrest at G1. Alterations of protein expressions of other cell cycle components were also observed. Moreover, inactivation of p16 and overexpression of cyclin D1 were commonly occurred in NPC. These findings provided evidence that cyclin D1 may have cell cycle-independent functions, which is critical in NPC tumongenesis. / Frequent gains of 12p13.31 region were confirmed by fluorescence in situ hybridization (FISH) analysis. According to expression array and real-time RT-PCR results, LTbetaR, TNFRSF1A and FLJ10665 were the three genes showing concordant amplification and overexpression in NPC xenograft. The LTbetaR protein, which is a lymphotoxin beta receptor, was confirmed to be recurrently overexpressed in NPC primary tumors and its overexpression may be involved in the activation of NF-kappaB in NPC. The findings suggested that it is one of the candidate oncogenes of this cancer. / In summary, three candidate NPC-associated oncogenes locating at 3q26.32, 11q13.3 and 12p13.31 were identified by genome-wide mapping analysis. Molecular and functional characterizations of these genes have provided evidences that they play critical roles in NPC tumorigenesis. / In this study, detailed investigation was carried out on a candidate NPC-associated oncogene, PIK3CA at 38q26.32, an amplicon reported previously. Copy number gains and amplifications of this gene, but not mutation, were demonstrated to be common events in NPC. The findings hence implied the importance of PIK3CA in NPC tumorigenesis. / Nasopharyngeal carcinoma is a common cancer in Southern China. Despite multiple genetic changes have been reported previously, limited information of NPC-associated oncogene is available. Since amplification is one of the major mechanisms in oncogene activation, a comprehensive characterization of common amplicons in human cancers is expected to facilitate the identification of the oncogenes involved in tumorigenesis. The aims of the present study is to define and characterize the common amplicons in NPC genome and then to identify NPC-associated oncogenes. / Or Yan Yan. / "July 2006." / Adviser: Kwok Wai Lo. / Source: Dissertation Abstracts International, Volume: 68-09, Section: B, page: 5715. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 179-201). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

Made available in DSpace on 2017-03-14T14:10:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2015. Added 1 bitstream(s) on 2017-03-14T14:42:47Z : No. of bitstreams: 1 000874648.pdf: 1962285 bytes, checksum: 509cd79e4e32dd7535b77a44ed7897de (MD5) / As mudanças nos padrões de respiração nasal afetam profundamente o crescimento craniofacial. Avanços tecnológicos, como a tomografia computadorizada de feixe cônico (TCFC), têm sido utilizados com o propósito de se observar tridimensionalmente a localização de diferentes estruturas do crânio, a face e o espaço aéreo faríngeo. Desta forma, é possível avaliar as alterações do espaço aéreo induzidas pelos aparelhos ortopédicos propulsores mandibulares. O intuito deste estudo foi avaliar as mudanças na faringe superior resultantes do avanço mandibular com aparelho Herbst, mediante análise do método de sobreposição de coordenadas tridimensionais matemáticas. A amostra deste estudo está composta por 24 pacientes, 10 do gênero feminino e 14 do gênero masculino (16,1 anos no início de tratamento), tratados por 8 meses com aparelho Herbst, sendo comparados com o grupo controle composto de 7 pacientes do gênero feminino (13,54 anos ao início do T1). Todos os indivíduos apresentavam má oclusão classe II divisão 1ª e já haviam passado pelo surto de crescimento pubertário (avaliados e pareados com radiografia de mão e punho). Os exames tomográficos foram realizados em dois tempos para cada paciente. A fase inicial foi realizada com a localização e identificação de 79 pontos anatômicos nos eixos: axial, coronal e sagital, sendo que 26 pontos anatômicos (base do crânio, maxila, mandíbula   37   vértebra e hióide) foram adotados para a análise final com auxílio do software AVIZO®. Após o processo de calibração, cada variável foi mensurada três vezes. A análise estatística dos dados foi realizada por meio do Test de Levane e teste T de Student ao nível de significância de 5 %. A confiabilidade das medidas apresentaram boa replicabilidade (ICC ≥ 0,921), com exceção da borda superior de vértebra cervical 3 e dos pontos inferiores da coana... (Resumo completo, clicar acesso eletrônico abaixo) / Changes in nasal breathing pattern affect the craniofacial growth. Technological advances, such as Cone beam computed tomography (CBCT), have been used in order to observe three-dimensionally (3D) the skull, face and pharyngeal airway space. The latter, with possible assessment of airway changes induced by orthopedic activators. The aim of this study was to evaluate the changes of the upper airway space resulted from mandibular advancement with Herbst appliance through superposition method of mathematical 3D coordinates. The sample was composed of 24 patients, 10 females and 14 males (16.1 years at the start of treatment - T1) treated for 8 months with Herbst appliance, and compared with a group control composed of 7 females (13.54 yrs at T1). Individuals of the samples were patients with malocclusion Class II division 1, already been through the pubertal growth spurt. The growth sprunt was assessment with hand/wrist radiographs. For each patient, CBCT scans were performed in two stages. The initial phase was conducted by location and identification of 79 anatomical points in the shaft, axial, coronal and sagittal views. Twenty-six anatomical points (skull base, maxilla, vertebra and Hyoid jaw) were adopted for the final analysis using Avizo analysis software®. After calibration of the examiner, each variable was measured three times. The statistical analysis was performed using Levene Test and t-Test with   39   significance level of 5%. The reliability of the measurements showed good reproducibility (ICC ≥ 0.92), exception were the top edge of cervical vertebra 3 and lower border of the Choanae. The results indicated statistical significance in axis Z for PNS (p = 04) compared to control group and for to tip of the epiglottis (p=0.02) compared with control group. Other structures, which were statistically significant, were the left portion of the greater cornu of hyoid...(Complete abstract electronic access below)

Thesis (M. Phil.)--University of Hong Kong, 1982.