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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.
101

DNA precursor biosynthesis-allosteric regulation and medical applications

Rofougaran, Reza January 2008 (has links)
Ribonucleotide reductase (RNR) is a key enzyme for de novo dNTP biosynthesis. We have studied nucleotide-dependent oligomerization of the allosterically regulated mammalian RNR using a mass spectrometry–related technique called Gas-phase Electrophoretic Mobility Macromolecule Analysis (GEMMA). Our results showed that dATP and ATP induce the formation of an α6β2 protein complex. This complex can either be active or inactive depending on whether ATP or dATP is bound. In order to understand whether formation of the large complexes is a general feature in the class Ia RNRs, we compared the mammalian RNR to the E. coli enzyme. The E. coli protein is regarded a prototype for all class Ia RNRs. We found that the E. coli RNR cycles between an active α2β2 form (in the presence of ATP, dTTP or dGTP) and an inactive α4β4 form in the presence of dATP or a combination of ATP with dTTP/dGTP. The E. coli R1 mutant (H59A) which needs higher dATP concentrations to be inhibited than the wild-type enzyme had decreased ability to form these complexes. It remains to be discovered how the regulation functions in the mammalian enzyme where both the active and inactive forms are α6β2 complexes. An alternative way to produce dNTPs is via salvage biosynthesis where deoxyribonucleosides are taken up from outside the cell and phosphorylated by deoxyribonucleoside kinases. We have found that the pathogen Trypanosoma brucei, which causes African sleeping sickness, has a very efficient salvage of adenosine, deoxyadenosine and adenosine analogs such as adenine arabinoside (Ara-A). One of the conclusions made was that this nucleoside analog is phosphorylated by the T. brucei adenosine kinase and kills the parasite by causing nucleotide pool imbalances and by incorporation into nucleic acids. Ara-A-based therapies can hopefully be developed into new medicines against African sleeping sickness. Generally, the dNTPs produced from the de novo and salvage pathways can be imported into mitochondria and participate in mtDNA replication. The minimal mtDNA replisome contains DNA polymerase γA, DNA polymerase γB, helicase (TWINKLE) and the mitochondrial single-stranded DNA-binding protein (mtSSB). Here, it was demonstrated that the primase-related domain (N-terminal region) of the TWINKLE protein lacked primase activity and instead contributes to single-stranded DNA binding and DNA helicase activities. This region is not absolutely required for mitochondrial DNA replisome function but is needed for the formation of long DNA products.
102

Effets anti-tumoraux du VIP dans des cellules de neuroblastome / Antitumurals effects of VIP in neuroblastoma cells

Boisvilliers, Madryssa de 12 November 2015 (has links)
Le neuroblastome (NB) est un cancer pédiatrique dérivé de la crête neurale. Les NB à haut risque sont des tumeurs peu différenciées présentant une amplification de MYCN et les plus agressives possèdent en plus une mutation d'ALK. Pour améliorer le traitement de ces tumeurs, les nouvelles thérapies cherchent à induire la différenciation cellulaire, l'inhibition de MYCN et la réduction de la signalisation d'ALK. Les résultats obtenus indiquent que le VIP induit une neuritogenèse dans les cellules de NB à haut risque SK-N-DZ et Kelly, et réduit en plus l'expression de MYCN dans les cellules Kelly, comme précédemment observé pour les cellules IMR-32. En parallèle, le VIP diminue l'invasion des cellules Kelly et IMR-32 et réduit également l'activité d'AKT qui est impliquée dans la signalisation d'ALK, dans les cellules Kelly qui présentent la mutation ALK F1174L. Certains effets du VIP sont dépendants de la PKA. Des analogues du PACAP, un peptide apparenté au VIP, présentent une efficacité supérieure à celle du VIP dans les cellules Kelly. Les effets du VIP sur la neuritogenèse et l'expression de MYCN dans ces cellules sont médiés par le récepteur VPAC2 qui peut avoir une localisation nucléaire dans les lignées cellulaires et les cellules de patients atteints de NB. Une délocalisation de ce récepteur nucléaire par ses propres ligands est observée. De plus, des cellules souches mésenchymateuses humaines dérivées du tissu adipeux induisent la différenciation des cellules de NB via les peptides VIP et/ou PACAP. L'ensemble de ces résultats indiquent que le VIP et des analogues du PACAP agissent sur des processus moléculaires et cellulaires qui pourraient réduire l'agressivité des NB à haut risque, et pourraient donc présenter un intérêt pour une nouvelle thérapie. / Neuroblastoma (NB) is a pediatric cancer derived from neural crest. High-risk NB are poorly differentiated tumors with MYCN amplification and the most aggressive forms in addition have an ALK mutation. To improve the treatment of these tumors, the new therapies aim to induce cell differentiation, inhibition of MYCN and reduction of ALK signaling. The obtained results indicate that the neuropeptide VIP induces neuritogenesis in high-risk SK-N-DZ and Kelly NB cells, and in addition reduces the expression of MYCN in Kelly cells, as previously observed in IMR-32 cells. In parallel, VIP decreases Kelly and IMR-32 cell invasion and also reduces the activity of AKT that is involved in the signaling of ALK, in Kelly cells harboring the mutation ALK F1174L. Most of these VIP effects are PKA-dependent. Analogs of PACAP, a VIP-related peptide, exhibit a higher efficiency than VIP in Kelly cells. VIP effects on neuritogenesis and MYCN expression in these cells are mediated by the VPAC2 receptor which can have a nuclear localization in the NB cell lines and in NB from patients. A relocation of this nuclear receptor by its own ligand is observed. Moreover, human mesenchymal stem cells derived from adipose tissue induce NB cells differentiation via VIP and/or PACAP peptides. Taken together, these results indicate that VIP and PACAP analogs act on molecular and cellular processes that might reduce aggressiveness of high-risk NB, and thus could be of interest for new therapy.
103

Programas de controle de Aedes aegypti (Diptera:Culicidae): análise do efeito da temperatura ambiente sobre a eficiência do larvicida Pyriproxyfen em laboratório / Surveillance programs for Aedes aegypti (Diptera: Culicidae) control: analysis of the temperature effect over the efficiency of Pyriproxyfen as a larvicide in laboratory conditions

Moura, Lídia 22 March 2019 (has links)
Programas brasileiros de controle populacional do mosquito Aedes aegypti são caracterizados por incluírem ações integradas entre população e poder público, compreendendo suplementarmente a aplicação de inseticidas nos potenciais criadouros do mosquito. Um dos compostos utilizados para o controle populacional de mosquitos é o Pyriproxyfen, um regulador de crescimento de insetos que age durante os estágios imaturos impedindo a emergência das larvas para a fase adulta. Muitas pesquisas, em condições laboratoriais controladas, encontraram resultados eficientes na aplicação desse larvicida, inferindo a confirmação de eficácia para uso nos programas de controle. Contudo, esses trabalhos disponíveis desconsideram a interferência por fatores ambientais (e.g. temperatura, luminosidade, pH) o que, como consequência, pode apresentar diferenças nos resultados em ambiente natural. Dentre esses fatores, é importante o destaque a temperatura, que apresenta o potencial de produzir diferenças na eficiência do composto, uma vez que há evidências de interferência tanto na velocidade e no sucesso de desenvolvimento das larvas quanto da composição química do larvicida. Dessa forma, o presente trabalho avaliou o efeito da variação da temperatura na eficiência do larvicida Pyriproxyfen para controle populacional de larvas de Aedes aegypti. Para isso, foram realizados experimentos avaliando o efeito combinado de três diferentes temperaturas (20°C, 25°C, 30°C) e cinco diferentes concentrações de Pyriproxyfen (0,0001; 0,001; 0,01; 0,1 e 1 mg.L-1), sendo as dosagens escolhidas em função da recomendação da Organização Mundial da Saúde (0,01 mg/L). Os testes foram realizados em incubadora BOD, com temperatura controlada desde a eclosão para evitar estresse térmico nas larvas. Também foi analisado o efeito sub letal do composto, nas respostas em longevidade dos mosquitos e do tamanho alar como indicador do tamanho das fêmeas provenientes dos tratamentos a 20°C e a 30°C. Quando aumentou-se a temperatura em 5°C (de 25°C para 30°C), houve redução em 30% da eficiência do larvicida na menor dosagem ,redução de 10% da eficácia na concentração de 0,001 mg/L e redução em 20% na concentração de 0,01 mg/L. Para todas as concentrações testadas, os mosquitos sobreviventes tiveram sua longevidade reduzida significativamente se comparados aos mosquitos desenvolvidos em um ambiente sem o composto. Ainda, as fêmeas emergentes do ambiente a 30°C foram significativamente maiores que as fêmeas que se desenvolveram a 20°C. No que se refere ao tamanho de fêmeas, entre a mesma temperatura não houve diferença significativa com relação ao tamanho das asas. Estes resultados indicam que, apesar da alta eficiência do Pyriproxyfen, deve-se considerar com cautela a influência que os fatores ambientais têm sobre o efeito de compostos inseticidas no controle de vetores, uma vez que estes são capazes de interferir no cenário epidemiológico. Ademais, considerar dosagens diferentes de acordo com os fatores ambientais em campo pode trazer benefícios no uso mais racional de compostos inseticidas bem como serem mais eficientes no controle efetivo do vetor alvo. / Surveillance brazilian programs for populational control of the Aedes aegypti mosquito are characterized for applying integrated actions between the government and the municipalities population, comprising as a supplementary measure the application of pesticides. One of these compounds is Pyriproxyfen, a insect growth regulator that acts during the imature stages of the organismo, therefore preventing its emmergence to the adult stage. Many researches, at laboratory conditions, found efficient outcomes by testing this larvicide, inferring its confirmation of efficacy of application during the surveillance programs. However, these studies disconsider the possibility of interference by evironmental factors, such as temperature, luminosity and pH variations. Among these factors, the environmental temperature is highlighted, considering the existing evidence of interference in the larval development and at the chemical composition of the larvicide. Thus, this study aims to assess the temperature effect over the efficiency outcomes of the Pyriproxyfen as a larvicide for Aedes aegypti control. Were executed experiments analyzing the combined effect of three different temperatures (20°C, 25°C, 30°C) and five concentrations of Pyriproxyfen (0,0001 mg/L, 0,001 mg/L, 0,01 mg/L, 0,1 mg/L and 1 mg/L). These tests were performed in a BOD incubator, with controlled and constant temperature, since the eclosion of the I instar larvae until the end of the test. Dead larvae were removed and registered daily. Were analyzed the sub lethal outcomes, by the longevity of the survivors and were calculated the wing size of the females from 20°C and 30°C as na indicator of body size of these female mosquitoes. When increased 5ºC in the temperature, from 25°C to 30°C, were observed an decrease in the efficiency of the larvicide by 30% at the lowest concentration, by 10% at a tem times higher concentration (0,001 mg/L) and a decrease by 20% at the concentration of 0,01 mg/L. For all concentrations assessed, the survivors lived less time than the mosquitoes which developed at na ambient without the Pyriproxyfen contamination. Yet, the females from the warmest environment, at 30ºC, were bigger than the females that developed in a cooler environment (20°C). The results indicate that, despite of the high efficiency of this larvicide, we must consider with caution the influence by environmental factors in field conditions, since that they present the possibility of interfering directly or indirectly at the epidemiologic scenario. Furthermore, considering different dosages according to the environmental factors in the field can bring benefits in the more rational use of insecticidal compounds as well as being more efficient in the effective control of the target vector.
104

Síndrome da apnéia do sono na acromegalia: impacto do tratamento sobre o metabolismo dos carboidratos / Sleep apnea syndrome on acromegaly: treatment impact on carbohydrates metabolism

Duarte, Felipe Henning Gaia 05 August 2011 (has links)
Introdução: A acromegalia é uma doença rara, caracterizada pela produção aumentada de hormônio do crescimento, causada geralmente por um adenoma hipofisário, ocasionando uma série de comorbidades como apneia do sono e resistência insulínica que acarretam um aumento na mortalidade e redução da expectativa de vida. Objetivo: O objetivo deste estudo foi avaliar o impacto da terapêutica da apneia do sono com um dispositivo de pressão positiva contínuas nas vias aéreas (CPAP) e avaliar o impacto desta terapêutica na resistência insulínica pela realização do clamp euglicêmico hiperinsulinêmico (CEH). Pacientes: De 156 acromegálicos regularmente atendidos na unidade de Neuroendocrinologia do HC-FMUSP, foram selecionados 12 indivíduos com apneia do sono de moderada a grave em uso de análogos da somatostatina (AS). Método: Os pacientes foram randomizados em dois grupos com seis integrantes. O grupo A iniciou o tratamento com CPAP, e o grupo B, um adesivo dilatador nasal com efeito de placebo. A avaliação basal incluiu a polissonografia, determinação do GH, IGF-1, HbA1c, ácidos graxos livres, lípides, CEH, bem como os índices de resistência periférica à insulina (HOMA, HOMA2 e QUICKI). Após 3 meses de tratamento, os pacientes foram reavaliados pelos mesmos exames, sendo trocado o tratamento entre os grupos e feita nova avaliação, após mais 90 dias. Resultados: Analisando os resultados finais de todos os pacientes que fizeram uso do CPAP, foi observada uma redução significante na resistência periférica à insulina, verificada pelo índice de sensibilidade derivado do clamp (ISCLAMP, pré e pós- CPAP, 3,83 versus 6,11, p=0,032). Esta redução não foi observada no grupo que fez uso do adesivo nasal (ISCLAMP, pré e pós-adesivo, 5,53 versus 5,19, p=0,455). Não houve diferença significante nos níveis de lípides, HbA1c nem nos índices de resistência periférica à insulina. Conclusão: O tratamento da apneia do sono moderada a grave com CPAP, em pacientes acromegálicos em uso de AS, levou a uma redução da resistência periférica à insulina aferida pelo CEH, dado não observado por meio dos índices HOMA, HOMA2 e QUICKI / Introduction. Acromegaly is a rare disease, characterized by the production of high GH levels usually by pituitary adenoma leading to comorbidities as sleep apnea and insulin resistance, bringing increase of mortality and life span reduction. Objective: This study aims to assess the impact of treatment of sleep apnea with a continuous positive air pressure device (CPAP) on the insulin resistance by performing the hyperinsulinemic euglycemic clamp (HEC). Patients: From 156 acromegalic patients regularly attended on Neuroendocrine Unit of the Hospital das Clínicas, University of São Paulo Medical School, 12 subjects on somatostatin analogs (SA) harboring moderate to severe sleep apnea were selected. Methods: Patients were randomized in two groups of six subjects. Group A started treatment with CPAP while group B started treatment using a nasal dilator adhesive with placebo effect. Basal assessment included polysomnography, determination of GH, IGF-1, HbA1c, free fat acids, lipids assays, HEC as well as insulin resistance indexes (HOMA, HOMA2 and QUICKI). Patients were reevaluated after three months of treatment by the same tests and then the treatment was switched between groups with new assessment 90 days later. Results: A significant reduction on insulin resistance determined by the clamp derived sensibility index was observed after assessing the final data of all patients on CPAP (SICLAMP, pre and post CPAP, 3,83 versus 6,11, p=0,032). This reduction was not seen in the nasal dilator adhesive group (SICLAMP, pre and post adhesive, 5,53 versus 5,19, p=0,455). There was no significant difference on lipids, HbA1c or on peripheral insulin resistance indexes. Conclusion: CPAP treatment of acromegalic patients on AS with moderate to severe sleep apnea leaded to significant reduction on peripheral insulin resistance assessed by the HEC. HOMA, HOMA2 and QUICK did not detect this data
105

Ação de prostaglandinas tópicas na conjuntiva de coelhos.

Aguiar, Evian Valli January 2019 (has links)
Orientador: Eliane Chaves Jorge / Resumo: A utilização prolongada de colírios análogos de prostaglandinas (AP) no tratamento do glaucoma tem sido associada a alterações tóxicas e inflamatórias dos tecidos oculares. As causas destes efeitos adversos locais ainda não são bem conhecidas. Uma das hipóteses aventadas seria o efeito citotóxico dos conservantes dos colírios e outra o envolvimento das metaloproteinases, cuja expressão estaria relacionada às alterações estruturais induzidas pelo uso crônico dos AP. Objetivo: O objetivo deste estudo foi avaliar a conjuntiva de coelhos submetidos à tratamento ocular tópico com AP e solução conservante por meio de estudo histológico, morfométrico e imuno-histoquímico. Material e Métodos: Quarenta coelhos adultos sadios da raça Norfolk, de ambos os sexos, com peso entre 1500 e 2500g, foram divididos por sorteio em quatro grupos experimentais. Os olhos direitos dos animais foram tratados com uma gota diária de bimatoprosta 0,03%, travoprosta 0,004%, latanoprosta 0,005%, e solução conservante por 30 dias (20 animais) e 60 dias (20 animais). Todos os coelhos foram submetidos à avaliação clínica oftalmológica com documentação fotográfica. Após a eutanásia, os olhos foram enucleados e preparados para análise histológica, morfométrica e imuno-histoquímica com pesquisa de expressão de metaloproteinase 2 (MMP2). Resultados: Houve aumento de espessura epitelial e estromal em todos os grupos tratados, principalmente no grupo latanoprosta com 30 dias e bimatoprosta com 60 dias (p<0,001). A ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Prolonged use of prostaglandin (PA) analog drops in the treatment of glaucoma has been associated with toxic and inflammatory changes in ocular tissues. The causes of these local adverse effects are not yet well known. One of the hypotheses proposed would be the cytotoxic effect of the preservatives of the eye drops and another the involvement of the metalloproteinases, whose expression would be related to the structural alterations induced by the chronic use of PA. Objective: The objective of this study was to evaluate the conjunctiva of rabbits submitted to topical ocular treatment with PA and preservative solution by histological, morphometric and immunohistochemical study. Material and Methods: Forty healthy adult Norfolk rabbits, weighing between 1500 and 2500g, were divided by lot into four experimental groups. The right eyes of animals were treated with a daily drop of 0.03% bimatoprost, 0.04% travoprost, 0.005% latanoprost, and placebo preservative solution for 30 days (20 animals) and 60 days (20 animals). All rabbits were submitted to clinical ophthalmological evaluation with photographic documentation. After euthanasia, the eyes were enucleated and prepared for histological, morphometric and immunohistochemical analysis with metalloproteinase 2 (MMP2) expression research. Results: There was an increase in epithelial and stromal thickness in all treated groups, mainly in the 30 day latanoprost group and 60 day bimatoprost group (p <0.001). Histological analysis with... (Complete abstract click electronic access below) / Mestre
106

Influência de aditivos nas propriedades de comonômeros, copolímeros e compósitos a base de Bis-GMA, diluído com TEGDMA ou análogos sintetizados do Bis-GMA (CH3Bis-GMA e CF3Bis-GMA) / Influence of additives on the properties of comonomers, copolymers and composites based on Bis-GMA, diluted with TEGDMA or the synthesized Bis-GMA analogs (CH3Bis-GMA and CF3Bis-GMA)

Prakki, Anuradha 16 July 2007 (has links)
O objetivo deste estudo foi avaliar a influência de dois aditivos, propionaldehyde (propanal aldeído) e 2,3-butanedione (diquetona diacetil), nas propriedades de comonômeros, copolímeros e resinas compostas à base de Bis-GMA, quando diluído com TEGDMA, Bis-GMA propoxilado (CH3Bis-GMA) e Bis-GMA propoxilado fluorinado (CF3Bis-GMA). Comonômeros, copolímeros e compósitos experimentais foram preparados combinando Bis-GMA com TEGDMA, CH3Bis-GMA, CF3Bis-GMA e, aldeído (24 e/ou 32 mol%) e diquetona (24 e/ou 32 mol%). No caso dos compósitos, partículas híbridas silanizadas (bário aluminosilicato; 60 peso%) foram adicionadas aos comonômeros. Para a fotopolimerização, adicionou-se canforoquinona (0,2 peso%) e N,N-dimetil-p-toluidina (0,2 peso%). Os comonômeros e copolímeros experimentais tiveram as seguintes propriedades avaliadas: viscosidade, contração de polimerização, grau de conversão, ângulo de contato (em esmalte, dentina e vidro), temperatura de transição vítrea (DSC e equação de Fox), microdureza, alteração de rugosidade superficial e desgaste por abrasão. Os compósitos experimentais, tiveram avaliadas as seguintes propriedades: resistência flexural, módulo de elasticidade, tração diametral, módulo de resiliência, microdureza, alteração de rugosidade superficial e desgaste por abrasão. Os sistemas Bis-GMA/TEGDMA e Bis-GMA/CH3Bis-GMA tiveram suas propriedades significantemente alteradas pela incorporação de aditivos (propanal ou diquetona). Os aditivos (propanal/diquetona) não influenciaram de forma significante as propriedades do sistema Bis-GMA/CF3Bis-GMA. O efeito dos aditivos nas propriedades dos materiais analisados relaciona-se à sua abilidade em aumentar o grau de conversão de alguns sistemas resinosos / The purpose of this study was to evaluate the effect of two additives, propionaldehyde (aldehyde) and 2,3-butanedione (diketone), on the properties of Bis-GMA based comonomer, copolymer and composites when diluted with TEGDMA, propoxylated Bis- GMA (CH3Bis-GMA) and propoxylated fluorinated Bis-GMA (CF3Bis-GMA). Experimental comonomer/copolymer/composites were prepared combining Bis-GMA and TEGDMA, CH3Bis-GMA, CF3Bis-GMA, with aldehyde (24 and/or 32 mol%) and diketone (24 and/or 32 mol%). For composites, hybrid treated filler (barium aluminosilicate glass; 60 wt%) was added to monomer mixtures. Photopolymerization was effected by using camphorquinone (0.2 wt%) and N,N-dimethyl-p-toluidine (0.2 wt%). Experimental comonomer/copolymers viscosity, polymerization shrinkage, degree of conversion, contact angle (enamel, dentin and glass surfaces), glass transition temperature (DSC and Fox equation), microhardness, surface roughness changes and wear were evaluated. Experimental composites, flexural strength, modulus of elasticity, diametral tensile strength, modulus of resilience, microhardness, surface roughness changes and wear were also assessed. Bis-GMA/TEGDMA and Bis- GMA/CH3Bis-GMA systems had properties significantly influenced by incorporation of additives (either propanal or diketone). Additives (propanal/diketone) did not significantly influence on Bis-GMA/CF3Bis-GMA system properties. The effect of additives on the evaluated material properties is mainly attributed to their ability in improving some resin systems degree of conversion
107

Therapeutic potential of pheophorbide a-mediated photodynamic therapy (PA-PDT) and its immunomodulation in human breast cancer treatment. / CUHK electronic theses & dissertations collection

January 2011 (has links)
According to the results, Pa-PDT showed inhibitory effect on MDA-MB-231 cells in vitro with an IC50 value of 0.5 muM at 24 h. Pa-PDT was demonstrated to activate intracellular mitogen activated protein kinases (MAPK) pathways via reactive oxygen species (ROS) production. Pa-PDT IS also believed to induce extracellular signal-regulated kinase (ERK)-mediated autophagy and endoplasmic reticulum stress. Pa-PDT in combination with Tamoxifen is demonstrated to exert a synergetic effect in inhibiting cancer growth. The combination treatment induces both intrinsic and extrinsic apoptosis. Regarding the direct cancer cell killing activity, two dimensional gel electrophoresis screening revealed that Pa-PDT regulates proteins which involve in human leukocyte antigen (HLA) class I-restricted antigen-processing machinery. This activation of antigen presentation was confirmed by Western blot analysis and immunostaining. Furthermore, a cross-presentation of antigen with HLA class I proteins and 70-kDa heat shock protein was found in Pa-PDT-treated cells, as shown by the fluorescent microscopic observation and immunoprecipitation assay. Moreover, the immunogenicity of breast cancer cells was increased by Pa-PDT treatment that triggered phagocytic activity by human macrophages. Our findings provide the first evidence that Pa-PDT can trigger both apoptosis and anti-tumour immunity. / Cancer is one of the most lethal diseases worldwide. Treatments of cancer comprise surgical intervention, radiotherapy or chemotherapy; however, their side effects are still need to be overcome. In order to search for anti-cancer treatments with milder side effects and higher efficiency, traditional Chinese medicine (TCM) has been investigated. Previous study in our laboratory reported that pheophorbide a (Pa), an active compound purified from Scutellaria barbata, combined with photodynamic therapy (PDT) approach produces anti-tumour effect in a wide range of human cancers. Because of the lack of protocols for curing late phase breast cancer, my project is to investigate the therapeutic potential of Pa-PDT and its action mechanism on human breast cancer. A human breast cancer cell line MDA-MB-231, which is estrogen receptor nude and resistant to a conventional breast cancer drug tamoxifen, was used as an in vitro tumour model in my study to mimic the late stage of breast cancer. / Pheophorbide a (Pa) has been proposed to be a potential photosensitizer for the photodynamic therapy of human cancer. However, the immunomodulatory effect of Pa, in the absence of irradiation, has not yet been investigated. The present study revealed that Pa possessed immunostimulating effect on a murine macrophages cell line RAW 264.7. Pa could stimulate the growth of RAW 264.7 cells with the maximal effect at 0.5 muM after 48 h of treatment, where MAPK family including c-Jun N-tenninal kinase (JNK), ERK and p38 MAPK were activated by Pa treatment in a dose-dependent manner. Moreover, the induction of interleukin-6 and tumour necrosis factor-a secretion, and the enhancement of phagocytic activity were observed in Pa-treated RAW 264.7 cells. The results were similar in Pa-treated human immune competent cells (e.g. CD4+ and CD14+ cells) at higher Pa concentrations (from 1 to 10 muM). The present work is the first report to demonstrate the potential immunomodulatory effects of Pa on immune competent cells, apart from its well-known anti-tumour activity. / Bui Xuan, Ngoc Ha. / "December 2010." / Advisers: Fung Kwok Pui; Wong Chun Kwok. / Source: Dissertation Abstracts International, Volume: 73-04, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 123-144). / 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.
108

The anti-tumor and anti-angiogenic effects of photodynamic therapy with pheophorbide a on breast cancer in vitro and in vivo. / 脫鎂葉綠甲脂酸a光動力治療在抗乳癌腫瘤細胞和抗血管增生作用的體外和體內研究 / CUHK electronic theses & dissertations collection / Tuo mei ye lu jia zhi suan a guang dong li zhi liao zai kang ru ai zhong liu xi bao he kang xue guan zeng sheng zuo yong de ti wai he ti nei yan jiu

January 2011 (has links)
Hoi, Wan Heng. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 212-245). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
109

Bioactivity of chemically synthesized goniotriol and its analogues.

January 1994 (has links)
Hung Sau Ling. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves 131-137). / Table of Contents --- p.1 / Acknowledgements --- p.V / Abbreviations --- p.VI / Aim of investigation --- p.IX / Abstract --- p.XI / Chapter Chapter 1 --- General Introduction --- p.1 / Chapter 1.1 --- Cancer Chemotherapy --- p.2 / Chapter 1.2 --- Plants as sources of useful drugs --- p.4 / Chapter 1.3 --- Potent antitumor compounds found in Goniothalamus giganteus --- p.7 / Chapter 1.4 --- Brief introduction of GONIOTRIOL --- p.8 / Chapter 1.5 --- The study on the antitumor activities of the antitumor compounds --- p.9 / Chapter 1.6 --- Biochemistry study of the anticancer agents --- p.10 / Chapter Chapter 2 --- Materials and Methods --- p.18 / Chapter 2.1 --- Materials --- p.19 / Chapter 2.1.1 --- Animals --- p.19 / Chapter 2.1.2 --- "Buffers, Culture Media and Chemicals" --- p.19 / Chapter 2.1.3 --- Cell lines --- p.20 / Chapter 2.1.4 --- Dye solutions --- p.21 / Chapter 2.1.5 --- Reagents and buffers for Agarose gel --- p.21 / Chapter 2.1.6 --- Synthetic goniotriol and its derivatives --- p.21 / Chapter 2.2 --- Methods --- p.23 / Chapter 2.2.1 --- Radioactive Precursor Incorporation Assays --- p.23 / Chapter 2.2.2 --- MTT assay --- p.24 / Chapter 2.2.3 --- Neutral Red assay --- p.24 / Chapter 2.2.4 --- Isolation and preparation of cells --- p.25 / Chapter 2.2.5 --- Assay for the solvent effect --- p.25 / Chapter 2.2.6 --- Assay for the in vitro antitumor activity THC88 on different cell lines --- p.27 / Chapter 2.2.7 --- Assay of the effect of THC86 on solid sarcoma Scl80 in vivo --- p.28 / Chapter 2.2.8 --- Assay of the effect of THC86 on peritoneal Scl80 in vivo --- p.28 / Chapter 2.2.9 --- Assay of the effect of THC89 on peritoneal EAT in vivo --- p.28 / Chapter 2.2.10 --- Assay of synthetic compound (THC89 and THC87) on the mitogenic activity of spleen lymphocytes --- p.29 / Chapter 2.2.11 --- Assay of synthetic compound (THC87) on the proliferation of murine bone marrow cells from compound- treated mice --- p.30 / Chapter 2.2.12 --- "Assay of synthetic compounds (Ml, P51 and P1) on nonmalignant cell-line" --- p.31 / Chapter 2.2.13 --- Assay of antitumor activity of synthetic compound (THC86)on PU5-1.8 --- p.31 / Chapter 2.2.14 --- Assay of the cytocidal effect of THC86 --- p.32 / Chapter 2.2.15 --- "Assay on the effect of THC86 on the synthesis of DNA, RNA and protein" --- p.32 / Chapter 2.2.16 --- Direct DNA cleavage by THC86 --- p.33 / Chapter 2.2.17 --- DNA fragmentation assay / Chapter 2.2.18 --- Assay of the effect of the synthetic compound (THC86) on different growth fraction of the cells / Chapter 2.2.19 --- Mitosis Study / Chapter 2.2.20 --- Assay for the stability of the synthetic compounds / Chapter Chapter 3 --- Structure / activity relationship of the synthetic compounds --- p.36 / Chapter 3.1 --- Results --- p.37 / Chapter 3.1.1 --- In vitro antitumor activity of the synthetic compounds --- p.37 / Chapter 3.2 --- Discussion --- p.45 / Chapter Chapter 4 --- Antitumor activities of the synthetic compounds --- p.63 / Chapter 4.1 --- Results --- p.64 / Chapter 4.1.1 --- Solvent effect in the screening process --- p.64 / Chapter 4.1.2 --- The effect of the synthetic compound (THC88) on different cell lines --- p.69 / Chapter 4.1.3 --- In vivo anti-tumor activities of the synthetic compounds --- p.71 / Chapter 4.1.3a --- Effect of THC86 on solid sarcoma Sc180 in vivo --- p.71 / Chapter 4.1.3b --- Effect of THC86 on peritoneal Scl80 in vivo --- p.71 / Chapter 4.1.3c --- Effect of THC89 on peritoneal EAT in vivo --- p.72 / Chapter 4.1.4 --- Cytotoxic effect of the tested compounds on normal cells --- p.77 / Chapter 4.1.4a --- Cytotoxic effect of THC89 on normal splenocytes in vitro --- p.77 / Chapter 4.1.4b --- Effect of THC87 on the proliferation of splenocytes --- p.77 / Chapter 4.1.4c --- Effect of THC87 on the proliferation of murine bone marrow cells --- p.78 / Chapter 4.1.4d --- Cytotoxic effect on non-malignant cell-line BALB/c 3T3/A31 --- p.78 / Chapter 4.2 --- Discussion --- p.85 / Chapter Chapter 5 --- The study on the antiproliferative mechanisms of the synthetic compounds --- p.88 / Chapter 5.1 --- Results --- p.89 / Chapter 5.1.1 --- "Effect of the synthetic compounds on Cell Growth, DNA, RNA and Protein" --- p.89 / Chapter 5.1.1a --- Effect of THC86 on PU5-1.8 (macrophage-like tumor) --- p.89 / Chapter 5.1.1b --- Cytocidal effect of THC86 on EAT --- p.89 / Chapter 5.1.1c --- "Effect of the synthetic compounds on synthesis of DNA, RNA and protein" --- p.90 / Chapter 5.1.2 --- Study of the synthetic compounds on the interactions of DNA --- p.101 / Chapter 5.1.2a --- DNA cleavage assay --- p.101 / Chapter 5.1.2b --- DNA fragmentation assay --- p.101 / Chapter 5.1.3 --- Effect of the synthetic compounds on different growth fraction of the cells --- p.104 / Chapter 5.1.4 --- Mitosis study of the synthetic compounds --- p.106 / Chapter 5.1.5 --- Investigation of the stability of the synthetic compounds in culture medium --- p.112 / Chapter 5.2 --- Discussion --- p.117 / Chapter Chapter 6 --- General Discussion --- p.122 / References --- p.131
110

Endothelium-derived hyperpolarizing factor-mediated relaxation in coronary and pulmonary microcirculation: implications in cardiothoracic surgery.

January 2002 (has links)
Zou Wei. / Thesis submitted in: December 2001. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 98-119). / Abstracts in English and Chinese. / Declaration --- p.i / Acknowledgements --- p.ii / Publication lists --- p.iii / Abstract --- p.ix / Abbreviations --- p.xiii / List of tables and figures --- p.xiv / Chapter Chapter 1: --- General Introduction --- p.1 / Chapter 1.1. --- Endothelium-dependent relaxation in coronary and pulmonary circulation --- p.1 / Chapter 1.1.1. --- Endothelium-derived relaxing factors --- p.2 / Chapter 1.1.1.1. --- Nitric Oxide --- p.3 / Chapter 1.1.1.2. --- PGI2 --- p.5 / Chapter 1.1.1.3. --- EDHF --- p.6 / Chapter 1.1.2. --- EDHF in coronary and pulmonary circulation --- p.8 / Chapter 1.1.2.1. --- EDHF in coronary circulation --- p.8 / Chapter 1.1.2.2. --- EDHF in pulmonary circulation --- p.9 / Chapter 1.2. --- Effect of hyperkalemia on EDHF-mediated relaxation --- p.10 / Chapter 1.3. --- Organ Preservation Solutions --- p.13 / Chapter 1.3.1. --- Euro-Collins solution --- p.14 / Chapter 1.3.2. --- University of Wisconsin solution --- p.15 / Chapter Chapter 2: --- Objectives and research approaches --- p.16 / Chapter 2.1. --- Objectives --- p.16 / Chapter 2.1.1. --- "Endothelium-dependent relaxation resistant to INDO, L-NNA, and HbO in porcine and pulmonary coronary micro-arteries" --- p.16 / Chapter 2.1.2. --- "EET11,12 and EDHF-mediated function in porcine coronary micro-arteries" --- p.17 / Chapter 2.1.3. --- "Comparison of EC or UW solution on endothelium-dependent relaxation resistant to INDO, l-NNA, and HbO in porcine pulmonary arteries" --- p.17 / Chapter 2.2. --- Research approaches --- p.18 / Chapter 2.2.1. --- "Endothelium-dependence of the relaxation by BK or EET11,12" --- p.18 / Chapter 2.2.2. --- Effect of hypothermic storage with EC and UW solution on EDHF-related relaxation --- p.18 / Chapter 2.2.3. --- Time-dependent alteration of endothelium-dependent relaxation in pulmonary micro-arteries by EC and UW solution --- p.19 / Chapter 2.2.4. --- Effect of HbO in endothelium-dependent relaxation --- p.19 / Chapter Chapter 3: --- Material and Methods --- p.21 / Chapter 3.1. --- General Methods --- p.21 / Chapter 3.1.1. --- Porcine heart and lung collection and transportion / Chapter 3.1.2. --- Myograph --- p.21 / Chapter 3.1.3. --- Myosight --- p.24 / Chapter 3.1.4. --- Anatomizing blood vessel --- p.24 / Chapter 3.1.5. --- Mounting --- p.24 / Chapter 3.1.6 --- Normalization --- p.26 / Chapter 3.1.6.1. --- Normalization of coronary micro-artery --- p.27 / Chapter 3.1.6.2. --- Normalization of pulmonary micro-artery --- p.28 / Chapter 3.1.7. --- Precontraction --- p.30 / Chapter 3.1.8. --- Endothelium-dependent relaxation --- p.31 / Chapter 3.2. --- Coronary artery studies --- p.32 / Chapter 3.2.1. --- Porcine heart harvest and anatomy --- p.32 / Chapter 3.2.2. --- Characteristic of histology of porcine coronary micro-artery --- p.32 / Chapter 3.3. --- Pulmonary artery studies --- p.35 / Chapter 3.3.1. --- Porcine lung harvest and anatomy --- p.35 / Chapter 3.3.2. --- Characteristic of histology of porcine pulmonary micro- artery --- p.36 / Chapter 3.4. --- Drugs --- p.41 / Chapter 3.4.1. --- Drugs --- p.41 / Chapter 3.4.2. --- Preparation of oxyhemoglobin solution --- p.41 / Chapter 3.5. --- Statistical Analysis --- p.42 / Chapter 3.5.1. --- Calculation of EC50 --- p.42 / Chapter 3.5.2. --- Statistical analysis --- p.42 / Chapter Chapter 4: --- "Epoxyeicosatrienoic Acids (EET11,12) May Partially Restore EDHF-Mediated Function in Coronary Micro-Arteries" --- p.43 / Chapter 4.1. --- Abstract --- p.43 / Chapter 4.2. --- Introduction --- p.44 / Chapter 4.3. --- Experimental Protocol --- p.45 / Chapter 4.3.1. --- Precontraction --- p.45 / Chapter 4.3.2. --- "EDHF-mediated (INDO, L-NNA, and HbO-resistant) relaxation" --- p.45 / Chapter 4.3.3. --- "EET11,12-mediated relaxation after exposure to hyperkalemia" --- p.46 / Chapter 4.3.4. --- "The effect of incubation with EET11,12 on the BK-induced, EDHF-mediated relaxation" --- p.46 / Chapter 4.4. --- Results --- p.47 / Chapter 4.4.1. --- Resting force --- p.47 / Chapter 4.4.2. --- HbO and U46619-induced contraction force --- p.48 / Chapter 4.4.3. --- "EET11,12-induced relaxation in coronary micro-arteries after exposure to hyperkalemia" --- p.49 / Chapter 4.4.4. --- "The EDHF-mediated relaxation to BK resistant to INDO, l- NNA,and HbO" --- p.51 / Chapter 4.4.4.1. --- Incubated in either hyperkalemic solution (K+ 20mmol/L) or Krebs' solution (control) --- p.51 / Chapter 4.4.4.2. --- "Incubated in either hyperkalemic solution (K+ 20mmol/L) plus EET11,12 or Krebs' solution (control)" --- p.53 / Chapter 4.5. --- Discussion --- p.57 / Chapter 4.5.1. --- EDHF plays an important role in the coronary micro-arteries --- p.57 / Chapter 4.5.2. --- "EDHF-mediated (INDO, l-NNA, and HbO-resistant) relaxation in the coronary micro-arteries" --- p.58 / Chapter 4.5.3. --- "EET11,12 may partially mimic the EDHF-mediated relaxation in the porcine coronary micro-artery" --- p.59 / Chapter 4.5.4. --- "Effect of EET11,12 added in hyperkalemia may partially restore the EDHF-mediated relaxation in the porcine coronary micro-arteries" --- p.59 / Chapter Chapter 5: --- Impaired EDHF-Mediated Relaxationin Porcine Pulmonary Micro-arteries by Cold Store with Euro-Collin's and University of Wisconsin Solution --- p.61 / Chapter 5.1. --- Abstract --- p.61 / Chapter 5.2. --- Introduction --- p.62 / Chapter 5.3. --- Experimental Protocol --- p.64 / Chapter 5.3.1. --- Precontraction --- p.64 / Chapter 5.3.2. --- "Role of EDHF-mediated (INDO, L-NNA and HbO-resistant) relaxation in porcine pulmonary micro-arteries by BK orA23187" --- p.64 / Chapter 5.3.3. --- Effect of hyperkalemia or preservation solutions (EC or UW) on the EDHF-mediated relaxation by BK or A23187 --- p.65 / Chapter 5.3.3.1. --- The effect of hyperkalemia --- p.65 / Chapter 5.3.3.2. --- Effect of EC solution on the EDHF-mediated relaxation --- p.65 / Chapter 5.3.3.3. --- Effect of UW solution on the EDHF-mediated relaxation --- p.66 / Chapter 5.3.3.4. --- The effect of UW and EC solutions on the contractility of the pulmonary micro-artery --- p.66 / Chapter 5.4. --- Results --- p.66 / Chapter 5.4.1. --- Resting force --- p.66 / Chapter 5.4.2. --- U46619-induced contraction force --- p.67 / Chapter 5.4.3. --- Role of EDHF-mediated relaxation induced by BK or A23187 --- p.67 / Chapter 5.4.4. --- The effect of hyperkalemia --- p.71 / Chapter 5.4.5. --- Effect of EC solution on the EDHF-mediated relaxation --- p.72 / Chapter 5.4.6. --- Effect of UW solution on the EDHF-mediated relaxation --- p.73 / Chapter 5.4.7. --- The effect of UW and EC solution on the contractility of the pulmonary micro-artery --- p.73 / Chapter 5.5. --- Discussion --- p.77 / Chapter 5.5.1. --- EDHF-mediated endothelial function exists in the pulmonary micro-circulation --- p.77 / Chapter 5.5.2. --- Hyperkalemia exposure reduces EDHF-related relaxation and possible mechanism --- p.78 / Chapter 5.5.3. --- The effect of EC and UW solutions on the EDHF-media relaxation in the pulmonary micro-arteries --- p.79 / Chapter Chapter 6: --- General Discussion --- p.82 / Chapter 6.1. --- Endothelium-dependent vasodilators: BK and A23187 --- p.82 / Chapter 6.2. --- EDHF in porcine coronary and pulmonary micro-arteries --- p.84 / Chapter 6.2.1. --- EDHF in porcine coronary micro-arteries --- p.84 / Chapter 6.2.2. --- EDHF in porcine pulmonary micro-arteries --- p.87 / Chapter 6.2.3. --- Vascular stretch and release of endothelium-derived vasodilators --- p.87 / Chapter 6.2.4. --- "EET11,12" --- p.88 / Chapter 6.3. --- "Endothelium-dependent relaxation resistant to INDO, L- NNA, and HbO in porcine coronary and pulmonary microcirculation" --- p.89 / Chapter 6.4. --- "Alteration of endothelium-dependent relaxation resistant to INDO, l-NNA, and HbO after exposure to hyperkalemia" --- p.90 / Chapter 6.5. --- "Alteration of endothelium-dependent contraction resistant to INDO, L-NNA, and HbO after exposure to EC or UW solutions" --- p.91 / Chapter 6.6. --- Clinical implications --- p.92 / Chapter 6.7. --- Limitations --- p.93 / Chapter 6.7.1. --- Common limitations --- p.93 / Chapter 6.7.2. --- Limitation of in vitro study --- p.93 / Chapter 6.8. --- Future work --- p.94 / Chapter Chapter 7: --- Conclusion --- p.96 / References --- p.98 / Appendies / "Wei Zou, Qin Yang, Anthony PC Yim, & Guo-Wei He Epoxyeicosatrienoic acids (EET11,12) may partially restore endothelium- derived hyperpolarizing factor-mediated function in coronary micro- arteries. Annals of Thoracic Surgery. 2001; 72(12): 1970~1976."

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