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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.
71

Antifungal activities of metergoline, purpurin and baicalein on Candida species. / CUHK electronic theses & dissertations collection

January 2010 (has links)
Baicalein is known to be a potent antifungal agent and induces programmed cell death in Candida albicans. In the present study, we found that baicalein also inhibited the growth of C. krusei isolates. The minimal inhibitory concentrations of baicalein against eight C. krusei isolates were 1.35--2.70 microg/ml. One-hour exposure to baicalein elicited a consistent and moderate post-antifungal effect on the C. krusei isolates. Further flow cytometric study demonstrated a depolarization of mitochondrial membrane potential. However, both the levels of reactive oxygen species and DNA fragmentation were not significantly changed after baicalein treatment in C. krusei. It can be concluded that the antifungal activity of baicalein was mitochondria-dependent in both C. krusei and C. albicans, but the antifungal mechanism was different. Reactive oxygen species may not play a direct role and baicalein does not initiate programmed cell death or apoptosis in C. krusei. The structure-activity relationship study showed that the three hydroxyl groups in baicalein were essential for its antifungal potency. / Candidiasis has become a serious infection with very high mortality and morbidity in the world if not providing effective treatments. However, due to clinical limitation and resistance of the current antifungal agents, there is an urgent need to search for novel antifungals. In this study, after screening a compound library (n=400) for antifungal activity, three members (metergoline, purpurin and baicalein) were chosen for further study. Their antifungal characteristics and the antifungal mechanisms were investigated. / Metergoline, a serotonin receptor antagonist, was found to have potent antifungal activity against the intrinsically fluconazole-resistant human fungal pathogen Candida krusei. The minimal inhibitory concentration and minimal fungicidal concentration of metergoline against C. krusei were 4 microg/ml and 8 microg/ml respectively. Metergoline induced post-antifungal effect. Significant synergism was found in combination of metergoline with amphotericin B by a checkerboard assay, which may be due to the perturbation of cell permeability and increase in the intracellular accumulation of antifungal agents. Metergoline also inhibited extracellular phospholipase production in C. krusei. To gain insights into the mechanisms, intracellular changes that accompany apoptosis were examined by flow cytometry and spectrophotometry. The results showed an increase in the level of reactive oxygen species, depolarization of mitochondrial membrane potential, phosphatidylserine externalization, and positive terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labelling in the metergoline-treated C. krusei . Taken together, we conclude that metergoline may promote apoptosis in C. krusei through reactive oxygen species production and perturbation in mitochondrial homeostasis, implying its antifungal potential to treat candidiasis. / The antifungal activity of purpurin, a natural red anthraquinone pigment in madder root (Rubia tinctorum L.), was evaluated against Candida isolates by a broth microdilution assay. The minimal inhibitory concentrations of purpurin against Candida species isolates were 1.28--5.12 microg/ml. Mechanistic studies indicated that purpurin inhibited energy-dependent efflux pumps of Candida isolates. Furthermore, purpurin demonstrated a depolarization of mitochondrial membrane potential, suggesting a possible linkage of the antifungal mechanism of purpurin to Candida apoptosis. / Kang, Kai. / Adviser: Fong Wing Ping. / Source: Dissertation Abstracts International, Volume: 73-02, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 98-123). / 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. / Abstract also in Chinese.
72

Tumour necrosis factor alpha induces rapid reduction in AMPA receptor-mediated calcium entry in motor neurones by increasing cell surface expression of the GluR2 subunit: relevance to neurodegeneration

Rainey-Smith, S.R., Andersson, D.A., Williams, R.J., Rattray, Marcus January 2010 (has links)
No / The alpha-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptor (AMPAR) subunit GluR2, which regulates excitotoxicity and the inflammatory cytokine tumour necrosis factor alpha (TNFalpha) have both been implicated in motor neurone vulnerability in amyotrophic lateral sclerosis/motor neurone disease. TNFalpha has been reported to increase cell surface expression of AMPAR subunits to increase synaptic strength and enhance excitotoxicity, but whether this mechanism occurs in motor neurones is unknown. We used primary cultures of mouse motor neurones and cortical neurones to examine the interaction between TNFalpha receptor activation, GluR2 availability, AMPAR-mediated calcium entry and susceptibility to excitotoxicity. Short exposure to a physiologically relevant concentration of TNFalpha (10 ng/mL, 15 min) caused a marked redistribution of both GluR1 and GluR2 to the cell surface as determined by cell surface biotinylation and immunofluorescence. Using fura-2-acetoxymethyl ester microfluorimetry, we showed that exposure to TNFalpha caused a rapid reduction in the peak amplitude of AMPA-mediated calcium entry in a PI3-kinase and p38 kinase-dependent manner, consistent with increased insertion of GluR2-containing AMPAR into the plasma membrane. This resulted in a protection of motor neurones against kainate-induced cell death. Our data therefore, suggest that TNFalpha acts primarily as a physiological regulator of synaptic activity in motor neurones rather than a pathological drive in amyotrophic lateral sclerosis.
73

Bone morphogenetic proteins differentially regulate pigmentation in human skin cells

Singh, Suman K., Abbas, Waqas A., Tobin, Desmond J. January 2012 (has links)
No / Bone morphogenetic proteins (BMPs) are a large family of multi-functional secreted signalling molecules. Previously BMP2/4 were shown to inhibit skin pigmentation by downregulating tyrosinase expression and activity in epidermal melanocytes. However, a possible role for other BMP family members and their antagonists in melanogenesis has not yet been explored. In this study we show that BMP4 and BMP6, from two different BMP subclasses, and their antagonists noggin and sclerostin were variably expressed in melanocytes and keratinocytes in human skin. We further examined their involvement in melanogenesis and melanin transfer using fully matched primary cultures of adult human melanocytes and keratinocytes. BMP6 markedly stimulated melanogenesis by upregulating tyrosinase expression and activity, and also stimulated the formation of filopodia and Myosin-X expression in melanocytes, which was associated with increased melanosome transfer from melanocytes to keratinocytes. BMP4, by contrast, inhibited melanin synthesis and transfer to below baseline levels. These findings were confirmed using siRNA knockdown of BMP receptors BMPR1A/1B or of Myosin-X, as well as by incubating cells with the antagonists noggin and sclerostin. While BMP6 was found to use the p38MAPK pathway to regulate melanogenesis in human melanocytes independently of the Smad pathway, p38MAPK, PI3-K and Smad pathways were all involved in BMP6-mediated melanin transfer. This suggests that pigment formation may be regulated independently of pigment transfer. These data reveal a complex involvement of regulation of different members of the BMP family, their antagonists and inhibitory Smads, in melanocytes behaviour.
74

Estudo comparativo de fotocoagulação panretiniana com e sem ranibizumabe intravítreo no tratamento da retinopatia diabética proliferativa / A comparative study of panretinal photocoagulation with and without intravitreal ranibizumab in treatment of proliferative diabetic retinopathy

Ferraz, Daniel Araujo 28 August 2015 (has links)
Objetivo: Comparar o efeito da terapia da fotocoagulação panretiniana (PFC) associada à injeção intravítrea de Ranibizumabe (RBZ) versus terapia isolada com PFC em pacientes com retinopatia diabética proliferativa (RDP) precoce, virgens de tratamento, com ou sem edema macular diabético (DME) durante 6 meses de acompanhamento. Projeto: Estudo prospectivo intervencionista, randomizado e controlado. Métodos: Sessenta olhos de 30 pacientes com RDP bilateral precoce foram randomizados para o grupo de estudo (GE) que foram tratados com PFC associado a duas injeções de RBZ intravítreo (0.5mg/0.05ml) ou para o grupo controle (GC) tratados apenas com PFC. Mudanças na acuidade visual (AV) corrigida, na sensibilidade ao contraste (SC) e na espessura foveal (EF) foram comparados no início, e nos 1, 3 e 6 meses após o tratamento. Resultados: No GE, a diferença na média da AV do baseline para o mês 6 teve um aumento significativo de + 3,4 letras (p = 0,006) e uma diminuição significativa na EF de - 47.6um (p < 0,001). No GC, a diferença na média da AV teve uma diminuição de - 3,4 letras (p = 0,04) e uma mudança na EF de -3.8 um (p = 0,96). Com relação ao teste de SC dentre os 28 olhos do GE, houve uma melhora no mês 6 em relação ao baseline nos ciclos: 1,5 (p < 0.001) e 3,0 ciclo (p=0.023). Dentre os 30 olhos do GC, não houve uma diferença estatística nos momentos estudados. Conclusão: A injeção intravítrea de RBZ associado com PFC pode ser um tratamento eficaz em olhos de pacientes com RDP precoce e EMD / Purpose: To compare the efficacy of therapy with panretinal photocoagulation (PRP) and intravitreal ranibizumab (RBZ) injection versus PRP alone in patients with treatment-naive bilateral non-high risk proliferative diabetic retinopathy (PDR) with and without diabetic macular edema (DME) with a 6-month follow-up. Design: Prospective, interventional, randomized controlled trial. Methods: Sixty eyes of 30 patients with bilateral non-high risk PDR were randomized either to the study group (SG) receiving PRP plus two intravitreal ranibizumab injections (0.5mg/0.05ml), the first one week before and the second four weeks after the PRP or to the control group (CG) receiving PRP alone. Mean change in best-corrected visual acuity (BCVA), contrast sensitivity (CS) and central macular thickness (CMT) were compared at baseline and 1, 3 and 6 months after treatment. Results: Changes from baseline to 6 months showed in the SG an increased in the BCVA by + 3.4 letters (p= 0.006) with a decrease in CMT by - 47.6um (p < 0.001). In the CG, a decrease by - 3.4 letters (p = 0.04) and an decrease by -3.8um (p= 0.96). Regarding the CS in the SG, there was an improvement compared to baseline for the sixth month in the 1.5 (p < 0.001) and 3.0 cycles (p = 0.023). The CG did not show significant results from baseline to month 6. Conclusion: Intravitreal RBZ associated with PRP can be an effective treatment in eyes with non-high risk PDR and DME
75

Tratamento com inibidor da Rho quinase associado ou não ao uso de corticosteróides em cobaias com inflamação pulmonar alérgica crônica: modulação da inflamação, do estresse oxidativo, do remodelamento da matriz extracelular e da reativida / Treatment with Rho-kinase inhibitor associated or not with corticosteroids in guinea pigs with chronic allergic pulmonary inflammation: modulation of inflammation, oxidative stress, extracellular matrix remodeling, and responses of the airways and lung parenchyma

Pigati, Patricia Angeli da Silva 09 May 2013 (has links)
INTRODUÇÃO: Embora os corticosteróides sejam considerados tratamento padrão-ouro na asma, pacientes com asma grave não são totalmente controlados com este tratamento. Estudos prévios com inibidores da Rho quinase sugeriram uma influência benéfica destas drogas na asma, atuando como uma possível alternativa anti-inflamatória. No entanto, não há estudos anteriores avaliando os efeitos destes inibidores, associados ou não com corticosteróides, na modulação da mecânica do sistema respiratório e oscilatória do tecido pulmonar distal, assim como nas alterações histopatológicas, em modelo animal de inflamação pulmonar crônica. OBJETIVOS: Avaliar se o tratamento com o inibidor específico da Rho (Y- 27632), associado ou não com a dexametasona modula a resposta de mecânica pulmonar, inflamatória, de remodelamento da matriz extracelular e ativação do estresse oxidativo em cobaias com inflamação alérgica crônica. MÉTODOS: As cobaias receberam sete inalações de ovoalbumina (1-5mg/ml; grupo OVA) durante 4 semanas. A partir da quinta inalação, os animais do grupo da Rho quinase receberam inalação de Y-27632 (1mM) (grupo OVA-RHO) e ou dexametasona (2 mg.kg-1) associada ou não a Y-27632 (grupos OVA-C ou grupos ORC), 10 minutos antes de cada inalação com OVA. Setenta e duas horas depois da sétima inalação, os animais foram anestesiados, exsanguinados, o óxido nítrico exalado foi coletado e a mecânica do sistema respiratório (Ers e Rrs) e oscilatória do tecido pulmonar distal (Et e Rt) foram realizadas em condições basais e após desafio com OVA (0,1%). Após, as fatias de pulmão foram removidas e submetidas à avaliação histopatológica. RESULTADOS: Houve um aumento no óxido nítrico exalado, nas respostas máximas de Ers, Rrs, Rt e Et após desafio antigênico, nos eosinófilos, nas células positivas para IL-2, IL-4, IL-5, IL-13, IFN-?, iNOS, MMP-9, TIMP-1,TGF- ß, NF?B e no conteúdo do 8-iso-PGF2?, no conteúdo de fibras elásticas, colágenas e de actina em vias aéreas e no parênquima pulmonar distal do grupo OVA comparado ao controle (P<0,05). Nos grupos OVA-RHO, OVA-C e ORC houve uma diminuição em todos os parâmetros comparados ao grupo OVA (P<0,05). A associação do Y-27632 com o tratamento com corticosteróide (grupo ORC) potencializou a atenuação do conteúdo de colágeno e IFN-? na parede das vias aéreas e IL-2, IFN-?, 8-iso-PGF2? e NF-?B no parênquima distal comparado aos grupos OVA-RHO e OVA-C (P<0,05). No grupo ORC houve uma redução nas células positivas para TIMP-1 e eosinófilos no septo alveolar comparado ao grupo OVA-C (P<0,05). CONCLUSÕES: A inibição da Rho quinase ou o tratamento com corticosteróides contribuíram para o controle da resposta de mecânica pulmonar, da resposta eosinofílica e linfocitária Th1 e Th2, do remodelamento da matriz extracelular e da ativação do estresse oxidativo nas vias aéreas e parênquima distal neste modelo animal. A associação do inibidor da Rho quinase com o corticosteróide potencializou o controle de parte da resposta de remodelamento e de inflamação nas vias aéreas e parênquima. A inibição da Rho quinase associada ou não a corticosteróides pode ser considerada uma ferramenta farmacológica futura para o tratamento de doenças pulmonares crônicas / INTRODUCTION: Although corticosteroids are considered gold standard of asthma treatment, patients with serious asthma are not totally controlled with this treatment. Previous studies with Rho-kinase inhibitors suggested a beneficial influence of these drugs on asthma, being a possible anti-inflammatory alternative. However, there are no previous studies evaluating in an animal model of chronic pulmonary inflammation the effects of such inhibitors, combined or not with corticosteroids, on the mechanics modulation of the respiratory system and oscillation of distal pulmonary tissue, as well as on histopathological alterations. OBJECTIVES: To evaluate whether treatment with the specific Rho inhibitor (Y-27632), combined or not with dexamethasone, modulates the responses of pulmonary mechanics, inflammation, extracellular matrix remodeling, and oxidative stress activation in guinea pigs with chronic allergic inflammation. METHODS: Guinea pigs received seven ovalbumin inhalations (1-5mg/ml; OVA group) during 4 weeks. After the fifth inhalation, the animals of the Rho-kinase group received inhalation of Y-27632 (1mM) (OVA-RHO group) and/or dexamethasone (2 mg.kg-1), combined or not with Y-27632 (OVA-C groups or ORC groups), 10 minutes before each inhalation with OVA. Seventy-two hours following the seventh inhalation, the animals were anesthetized, exsanguinated, the exhaled nitric oxide was collected, and mechanics of the respiratory system (Ers and Rrs) and oscillation of the distal lung tissue (Et e Rt) were performed in basal conditions and after challenge with OVA (0.1%). Afterwards, lung slices were removed and submitted to histopathological evaluation. RESULTS: There was an increase of exhaled nitric oxide, maximum responses of Ers, Rrs, Et and Rt after antigen challenge, eosinophil counts, cells positive for IL-2, IL-4, IL-5, IL-13, IFN-?, iNOS, MMP-9, TIMP-1,TGF-ß, NF?B, and in the content of 8-iso-PGF2?, elastic fibers, collagen fibers and actin in the airways in distal lung parenchyma of the OVA group, compared to the control (P<0.05). In the OVA-RHO, OVA-C and ORC groups there was a decrease in all parameters, when compared to the OVA group (P<0.05). The treatment combining Y-27632 with corticosteroid (ORC group) maximized the attenuation of the content of collagen and IFN-y in the airways walls, and of IL-2, IFN-?, 8-iso-PGF2? and NF-?B in distal parenchyma, when compared to the OVA-RHO and OVA-C groups (P<0.05). In the ORC group, there was a reduction of cells positive for TIMP-1 and eosinophils in the alveolar septum, compared to the OVA-C group (P<0.05). CONCLUSIONS: Rho kinase or treatment with corticosteroids contributed to the control of the pulmonary mechanics response, Th1 and Th2 lymphocyte and eosinophil responses, extracellular matrix remodeling, and activation of the oxidative stress in the airways and distal parenchyma of this animal model. The combined treatment with Rho kinase and corticosteroid maximized the control of part of the remodeling response and inflammation of the airways and parenchyma. Rho-kinase inhibition combined or not with corticosteroids can be considered a future pharmacological tool for treatment of chronic pulmonary diseases
76

"Análise volumétrica da hiperplasia intimal intra-stent em pacientes diabéticos tratados com e sem abciximab" / Volumetric analysis of in-stent intimal hyperplasia in diabetic patients treated with or without abciximab

Chaves, Áurea Jacob 19 July 2004 (has links)
Noventa e seis pacientes com diabetes melito do tipo 2 foram randomizados para receberem ou não abciximab durante o implante eletivo de stent coronário, com o objetivo de determinar se esse inibidor da glicoproteína IIb/IIIa reduz a hiperplasia intimal intra-stent, avaliada pelo ultra-som intracoronário, aos seis meses de evolução. A análise volumétrica mostrou que o abciximab não reduz o volume de obstrução intra-stent nestes pacientes [41,3% (DP21,0%) versus 40,5% (DP18,3%), p=0,853]. / Ninety-six type 2 diabetics were randomly assigned to receive abciximab or no abciximab at the time of elective stent implantation to determine whether this IIb/IIIa glycoprotein inhibitor would reduce in-stent intimal hyperplasia, measured by intravascular ultrasound, at 6-month follow-up. Volumetric analysis showed that abciximab was not associated with a reduction of in-stent volume obstruction in diabetic patients [41.3% (DP21.0%) versus 40.5% (DP18.3%), p=0.853).
77

Screening of traditional Chinese medicine for anti-Alzheimer's disease drugs.

January 2005 (has links)
by Wong Kin Kwan Kelvin. / Thesis submitted in: September 2004. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 91-101). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.ii / 摘要 --- p.iv / Abbreviations --- p.x / List of Figures --- p.xiii / List of Tables --- p.xiv / Chapter Chapter 1 --- Intorduction --- p.1 / Chapter 1.1 --- Alzheimer,s disease --- p.1 / Chapter 1.2 --- Histopathological features --- p.1 / Chapter 1.3 --- Tau protein pathology and AD --- p.4 / Chapter 1.4 --- Tau protein kinase I (TPKI)- GSK-3β --- p.6 / Chapter 1.5 --- Tau protein kinase II (TPKII)- Cyclin dependent kinase 5 (Cdk5) --- p.8 / Chapter 1.6 --- Available treatment --- p.9 / Chapter 1.7 --- Objectives of the present study --- p.12 / Chapter Chapter 2 --- Screening for GSK-3p inhibitors from Traditional Chinese Medicine (TCM) --- p.13 / Chapter 2.1 --- Introduction --- p.13 / Chapter 2.1.1 --- Phosphorylation of tau in AD --- p.13 / Chapter 2.1.2 --- Gsk-3p inhibitors --- p.14 / Chapter 2.1.3 --- Screening of GSK-3β inhibitor from TCM --- p.16 / Chapter 2.2 --- Material and Methods --- p.18 / Chapter 2.2.1 --- Preparation of extracts and fractions (AOF1-5) --- p.18 / Chapter 2.2.2 --- General cell culture techniques --- p.21 / Chapter 2.2.3 --- "3-(4,5-dimethyltiazoI-2-yl)-2, 5-diphenyl-tetrazolium (MTT) assay of AOF" --- p.23 / Chapter 2.2.4 --- Recombinant DNA techniques --- p.23 / Chapter 2.2.5 --- Transfection of GSK-3β and tau cDNA into COS7 cells --- p.28 / Chapter 2.2.6 --- Extraction of total proteins from culture cells --- p.28 / Chapter 2.2.7 --- Quantitation of protein by the Bradford method --- p.29 / Chapter 2.2.8 --- Protein separation by sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS-PAGE) --- p.29 / Chapter 2.2.9 --- Western blot analysis --- p.31 / Chapter 2.2.10 --- GSK-3β kinase assay --- p.32 / Chapter 2.2.11 --- Determination of lithium content by atomic adsorption spectrophotometry --- p.34 / Chapter 2.3 --- Results --- p.35 / Chapter 2.3.1 --- Establishment of a co-transfected cell model for GSK-3β induced tau hyperphosphorylation --- p.35 / Chapter 2.3.2 --- Preliminary screening results of aqueous and ethanol extracts (AOF1 and AOF2) --- p.37 / Chapter 2.3.3 --- Ethanol extract of AOF inhibits GSK-3p induced tau phosphorylation in COS-7 cells --- p.40 / Chapter 2.3.5 --- Effect of the essential oils of AOF on GSK-3P induced tau phosphorylation --- p.46 / Chapter 2.3.6 --- The effect of AOF essential oil on GSK-3P activity in COS7 --- p.50 / Chapter 2.3.7 --- Lithium content of AOF extracts --- p.52 / Chapter 2.4 --- Discussion --- p.54 / Chapter Chapter 4 --- Evaluation of the in vivo efficacy of cryptotenshinone (CT) in Morris Water Maze Task (WMT) --- p.59 / Chapter 4.1 --- Introduction --- p.59 / Chapter 4.1.1 --- Involvement of Cholinergic system in cognitive dysfunction in AD --- p.59 / Chapter 4.1.2 --- Animal model for Alzheimer's disease --- p.60 / Chapter 4.1.3 --- Morris Watermaze Task (WMT) --- p.61 / Chapter 4.2 --- MATERIAL AND METHODS --- p.64 / Chapter 4.2.1 --- Morris Water maze setup --- p.64 / Chapter 4.2.2 --- Animal model --- p.66 / Chapter 4.2.3 --- Drug preparation --- p.67 / Chapter 4.2.4 --- Toxicity test of CT --- p.67 / Chapter 4.2.5 --- Water maze task (WMT) --- p.68 / Chapter 4.2.6 --- Visual acuity test --- p.73 / Chapter 4.3 --- RESULTS --- p.74 / Chapter 4.3.1 --- Chronic crytotanshinone treatment does not cause hepatic damages to the mice --- p.74 / Chapter 4.3.2 --- Training Session --- p.76 / Chapter 4.4 --- DISCUSSION --- p.85 / Chapter Chapter 5 --- General Discussion and Future Directions --- p.87 / Chapter 5.1 --- "AOF, the potential GSK-3 inhibitor" --- p.87 / Chapter 5.2 --- CT´ؤthe AChEI --- p.88 / References --- p.91 / Appendix --- p.102 / Chapter A1 --- Reagents for SDS-PAGE --- p.103 / Chapter A3 --- Solution components provided by QIAGEN Plasmid Maxipreps kit --- p.108 / Chapter A4 --- Reagents and medium for cell culture --- p.109 / Chapter A5 --- Reagents for kinase assay --- p.110 / Chapter A6 --- Raw data of figures --- p.112 / Chapter A7 --- Plasmid map of PCI-neo --- p.119
78

Tratamento com inibidor da Rho quinase associado ou não ao uso de corticosteróides em cobaias com inflamação pulmonar alérgica crônica: modulação da inflamação, do estresse oxidativo, do remodelamento da matriz extracelular e da reativida / Treatment with Rho-kinase inhibitor associated or not with corticosteroids in guinea pigs with chronic allergic pulmonary inflammation: modulation of inflammation, oxidative stress, extracellular matrix remodeling, and responses of the airways and lung parenchyma

Patricia Angeli da Silva Pigati 09 May 2013 (has links)
INTRODUÇÃO: Embora os corticosteróides sejam considerados tratamento padrão-ouro na asma, pacientes com asma grave não são totalmente controlados com este tratamento. Estudos prévios com inibidores da Rho quinase sugeriram uma influência benéfica destas drogas na asma, atuando como uma possível alternativa anti-inflamatória. No entanto, não há estudos anteriores avaliando os efeitos destes inibidores, associados ou não com corticosteróides, na modulação da mecânica do sistema respiratório e oscilatória do tecido pulmonar distal, assim como nas alterações histopatológicas, em modelo animal de inflamação pulmonar crônica. OBJETIVOS: Avaliar se o tratamento com o inibidor específico da Rho (Y- 27632), associado ou não com a dexametasona modula a resposta de mecânica pulmonar, inflamatória, de remodelamento da matriz extracelular e ativação do estresse oxidativo em cobaias com inflamação alérgica crônica. MÉTODOS: As cobaias receberam sete inalações de ovoalbumina (1-5mg/ml; grupo OVA) durante 4 semanas. A partir da quinta inalação, os animais do grupo da Rho quinase receberam inalação de Y-27632 (1mM) (grupo OVA-RHO) e ou dexametasona (2 mg.kg-1) associada ou não a Y-27632 (grupos OVA-C ou grupos ORC), 10 minutos antes de cada inalação com OVA. Setenta e duas horas depois da sétima inalação, os animais foram anestesiados, exsanguinados, o óxido nítrico exalado foi coletado e a mecânica do sistema respiratório (Ers e Rrs) e oscilatória do tecido pulmonar distal (Et e Rt) foram realizadas em condições basais e após desafio com OVA (0,1%). Após, as fatias de pulmão foram removidas e submetidas à avaliação histopatológica. RESULTADOS: Houve um aumento no óxido nítrico exalado, nas respostas máximas de Ers, Rrs, Rt e Et após desafio antigênico, nos eosinófilos, nas células positivas para IL-2, IL-4, IL-5, IL-13, IFN-?, iNOS, MMP-9, TIMP-1,TGF- ß, NF?B e no conteúdo do 8-iso-PGF2?, no conteúdo de fibras elásticas, colágenas e de actina em vias aéreas e no parênquima pulmonar distal do grupo OVA comparado ao controle (P<0,05). Nos grupos OVA-RHO, OVA-C e ORC houve uma diminuição em todos os parâmetros comparados ao grupo OVA (P<0,05). A associação do Y-27632 com o tratamento com corticosteróide (grupo ORC) potencializou a atenuação do conteúdo de colágeno e IFN-? na parede das vias aéreas e IL-2, IFN-?, 8-iso-PGF2? e NF-?B no parênquima distal comparado aos grupos OVA-RHO e OVA-C (P<0,05). No grupo ORC houve uma redução nas células positivas para TIMP-1 e eosinófilos no septo alveolar comparado ao grupo OVA-C (P<0,05). CONCLUSÕES: A inibição da Rho quinase ou o tratamento com corticosteróides contribuíram para o controle da resposta de mecânica pulmonar, da resposta eosinofílica e linfocitária Th1 e Th2, do remodelamento da matriz extracelular e da ativação do estresse oxidativo nas vias aéreas e parênquima distal neste modelo animal. A associação do inibidor da Rho quinase com o corticosteróide potencializou o controle de parte da resposta de remodelamento e de inflamação nas vias aéreas e parênquima. A inibição da Rho quinase associada ou não a corticosteróides pode ser considerada uma ferramenta farmacológica futura para o tratamento de doenças pulmonares crônicas / INTRODUCTION: Although corticosteroids are considered gold standard of asthma treatment, patients with serious asthma are not totally controlled with this treatment. Previous studies with Rho-kinase inhibitors suggested a beneficial influence of these drugs on asthma, being a possible anti-inflammatory alternative. However, there are no previous studies evaluating in an animal model of chronic pulmonary inflammation the effects of such inhibitors, combined or not with corticosteroids, on the mechanics modulation of the respiratory system and oscillation of distal pulmonary tissue, as well as on histopathological alterations. OBJECTIVES: To evaluate whether treatment with the specific Rho inhibitor (Y-27632), combined or not with dexamethasone, modulates the responses of pulmonary mechanics, inflammation, extracellular matrix remodeling, and oxidative stress activation in guinea pigs with chronic allergic inflammation. METHODS: Guinea pigs received seven ovalbumin inhalations (1-5mg/ml; OVA group) during 4 weeks. After the fifth inhalation, the animals of the Rho-kinase group received inhalation of Y-27632 (1mM) (OVA-RHO group) and/or dexamethasone (2 mg.kg-1), combined or not with Y-27632 (OVA-C groups or ORC groups), 10 minutes before each inhalation with OVA. Seventy-two hours following the seventh inhalation, the animals were anesthetized, exsanguinated, the exhaled nitric oxide was collected, and mechanics of the respiratory system (Ers and Rrs) and oscillation of the distal lung tissue (Et e Rt) were performed in basal conditions and after challenge with OVA (0.1%). Afterwards, lung slices were removed and submitted to histopathological evaluation. RESULTS: There was an increase of exhaled nitric oxide, maximum responses of Ers, Rrs, Et and Rt after antigen challenge, eosinophil counts, cells positive for IL-2, IL-4, IL-5, IL-13, IFN-?, iNOS, MMP-9, TIMP-1,TGF-ß, NF?B, and in the content of 8-iso-PGF2?, elastic fibers, collagen fibers and actin in the airways in distal lung parenchyma of the OVA group, compared to the control (P<0.05). In the OVA-RHO, OVA-C and ORC groups there was a decrease in all parameters, when compared to the OVA group (P<0.05). The treatment combining Y-27632 with corticosteroid (ORC group) maximized the attenuation of the content of collagen and IFN-y in the airways walls, and of IL-2, IFN-?, 8-iso-PGF2? and NF-?B in distal parenchyma, when compared to the OVA-RHO and OVA-C groups (P<0.05). In the ORC group, there was a reduction of cells positive for TIMP-1 and eosinophils in the alveolar septum, compared to the OVA-C group (P<0.05). CONCLUSIONS: Rho kinase or treatment with corticosteroids contributed to the control of the pulmonary mechanics response, Th1 and Th2 lymphocyte and eosinophil responses, extracellular matrix remodeling, and activation of the oxidative stress in the airways and distal parenchyma of this animal model. The combined treatment with Rho kinase and corticosteroid maximized the control of part of the remodeling response and inflammation of the airways and parenchyma. Rho-kinase inhibition combined or not with corticosteroids can be considered a future pharmacological tool for treatment of chronic pulmonary diseases
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Avaliação estrutural e funcional da mácula nos pacientes com retinopatia diabética proliferativa submetidos à panfotocoagulação associada a injeções intravítreas de bevacizumabe / Structural and functional assessment of the macula in patients with proliferative diabetic retinopathy submitted to panretinal photocoagulation associated with intravitreal injections of bevacizumab

Preti, Rony Carlos 23 November 2012 (has links)
INTRODUÇÃO: O presente estudo avaliou o tratamento com injeções intravítreas de Bevacizumabe (IVB) associadas à panfotocoagulação (PFC) da retina na retinopatia diabética proliferativa (RDP) de alto risco com ou sem edema macular (EM). MÉTODOS: Ensaio clínico randomizado, prospectivo, aberto e mascarado composto por pacientes com Diabetes melitos (DM) tipo 2. A acuidade visual (AV) foi medida com a tabela Early Treatment Diabetic Retinopathy Study e a sensibilidade ao contraste (SC) pela da tabela Vistech Consultants Incorporation 6500. Os pacientes foram submetidos a exame de angiofluoresceinografia para observação de neovascularização retiniana e isquemia macular e à tomografia de coerência óptica (OCT), para se obter a espessura foveal (EF) e o volume macular (VM). Após os exames, um dos olhos do mesmo paciente foi randomizado para realizar somente PFC, grupo controle (GC), e o outro para PFC associado a injeções IVB, grupo de estudo (GE). A hemorragia vítrea (HV) e a presença de complicações também foram avaliadas. RESULTADOS: Dos 42 pacientes incluídos, 35 completaram o estudo. A média de idade foi de 56±8 anos, com predominância do gênero masculino 21 (60%). Vinte e seis (74%) pacientes eram portadores de Hipertensão Arterial Sistêmica com média de duração de 9±10 anos. A média de duração do DM foi de 18±9 anos sendo 23 (66%) usuários de insulina e 21 (68,5%), fácicos. A AV e a SC não demonstraram diferença entre os grupos no total da amostra. O GE demonstrou melhora em comparação ao GC na EF no 1º mês, e no VM nos 1° e 3º meses de seguimento. Quanto aos 12 pacientes com EM bilateral somente a EF demonstrou redução no GE no 1º mês de seguimento. Ao se avaliar os grupos separadamente, o GC apresentou agravamento da AV e SC durante todo seguimento. Houve também aumento da EF nos 1º e 6º meses e VM nos 1º , 3º e 6º meses de seguimento. O GE demonstrou estabilização da AV, SC, EF e VM. Correlacionado às funções visuais, AV com a SC, toda vez que houve piora da AV esta foi acompanhada pelo agravamento da SC em todos os momentos no GC e GE. Quando correlacionadas as AV e SC com as EF e VM, toda vez que a espessura macular aumentava, havia piora da função visual. Dos sete pacientes excluídos do estudo por apresentarem HV, cinco integravam o GC e dois o GE. Não houve aparecimento de catarata, endoftalmite e/ou aumento significativo da pressão ocular. CONCLUSÃO: Na RDP de alto risco, o uso adjuvante de injeções intravítreas de Bevacizumabe associadas à panfotocoagulação da retina pode estabilizar a AV, SC, EF e VM, diminuir a incidência de HV e reduzir a da espessura macular. Em relação à correlação entre as variáveis, quando houve piora da AV, esta foi acompanhada da piora da SC e o aumento da EF e VM causaram piora da AV e SC / INTRODUCTION: This study evaluated the treatment with intravitreal injections of Bevacizumab (IVB) associated with panretinal photocoagulation (PRP) in high-risk proliferative diabetic retinopathy (PDR) with or without diabetic macular edema (DME). METHODS: Prospective, open and masked, randomized clinical trial, composed of patients with type 2 Diabetes Mellitus (DM). The visual acuity (VA) was measured with the Early Treatment Diabetic Retinopathy Study charts and the contrast sensitivity (CS) through the chart of Vistech Consultants Incorporation 6500. Patients were submitted to a fluorescein angiography examination to observe retinal neovascularization and macular ischemia and to an optical coherence tomography (OCT) to obtain the foveal thickness (FT) and macular volume (MV). After the tests, one of the eyes from the same patient was randomized to realize only the PRP, the control group (CG), and the other for PRP associated to IVB injections, the study group (SG). Vitreous hemorrhage (VH) and presence of complications were also evaluated. RESULTS: Thirty-five of the forty-two patients included, completed the study. The mean age was 56±8 years, with a predominance of 21 (60%) males. Twenty-six (74%) patients had systemic hypertension with a mean duration of 9±10 years. The mean duration of DM was 18±9 years, of which 23 (66%) were insulin users and 21 (68.5%) were phakic. The VA and CS showed no difference between groups in the total sample. The SG showed improvement compared to the CG in FT for the 1st month, and in MV for the 1st and 3rd month of follow-up. As for the 12 patients with bilateral ME, only the FT showed a reduction in the SG for the 1st month of follow-up. When evaluating the groups separately, the CG showed worsening of VA and CS at all times. There was also an increase of FT for the 1st and 6th months and of MV for the 1st, 3rd and 6th month follow-up. The SG showed stabilization of VA, CS, FT and MV. When correlated to visual functions, VA and CS, a worsening of the VA was accompanied every time by a worsening of the CS in both the CG and SG. When VA and CS are correlated to FT and MV, there was worsening of visual function whenever macular thickness increased. Of the seven patients excluded from the study by presenting VH, 5 belonged to the CG and the 2 to the SG. There was no incidence of cataracts, endophthalmitis and/or significant increase in intraocular pressure. CONCLUSION: In high-risk PDR, intraocular injections of Bevacizumab as an adjuvant treatment to PRP, can stabilize VA, CS, FT and MV, reduce of the incidence of VH and decrease the macular thickness. Regarding the correlation between variables, when there was a worsening of VA, this was accompanied by a worsening of the CS, and an increase in FT and MV caused the worsening of the VA and CS
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Estudo comparativo de fotocoagulação panretiniana com e sem ranibizumabe intravítreo no tratamento da retinopatia diabética proliferativa / A comparative study of panretinal photocoagulation with and without intravitreal ranibizumab in treatment of proliferative diabetic retinopathy

Daniel Araujo Ferraz 28 August 2015 (has links)
Objetivo: Comparar o efeito da terapia da fotocoagulação panretiniana (PFC) associada à injeção intravítrea de Ranibizumabe (RBZ) versus terapia isolada com PFC em pacientes com retinopatia diabética proliferativa (RDP) precoce, virgens de tratamento, com ou sem edema macular diabético (DME) durante 6 meses de acompanhamento. Projeto: Estudo prospectivo intervencionista, randomizado e controlado. Métodos: Sessenta olhos de 30 pacientes com RDP bilateral precoce foram randomizados para o grupo de estudo (GE) que foram tratados com PFC associado a duas injeções de RBZ intravítreo (0.5mg/0.05ml) ou para o grupo controle (GC) tratados apenas com PFC. Mudanças na acuidade visual (AV) corrigida, na sensibilidade ao contraste (SC) e na espessura foveal (EF) foram comparados no início, e nos 1, 3 e 6 meses após o tratamento. Resultados: No GE, a diferença na média da AV do baseline para o mês 6 teve um aumento significativo de + 3,4 letras (p = 0,006) e uma diminuição significativa na EF de - 47.6um (p < 0,001). No GC, a diferença na média da AV teve uma diminuição de - 3,4 letras (p = 0,04) e uma mudança na EF de -3.8 um (p = 0,96). Com relação ao teste de SC dentre os 28 olhos do GE, houve uma melhora no mês 6 em relação ao baseline nos ciclos: 1,5 (p < 0.001) e 3,0 ciclo (p=0.023). Dentre os 30 olhos do GC, não houve uma diferença estatística nos momentos estudados. Conclusão: A injeção intravítrea de RBZ associado com PFC pode ser um tratamento eficaz em olhos de pacientes com RDP precoce e EMD / Purpose: To compare the efficacy of therapy with panretinal photocoagulation (PRP) and intravitreal ranibizumab (RBZ) injection versus PRP alone in patients with treatment-naive bilateral non-high risk proliferative diabetic retinopathy (PDR) with and without diabetic macular edema (DME) with a 6-month follow-up. Design: Prospective, interventional, randomized controlled trial. Methods: Sixty eyes of 30 patients with bilateral non-high risk PDR were randomized either to the study group (SG) receiving PRP plus two intravitreal ranibizumab injections (0.5mg/0.05ml), the first one week before and the second four weeks after the PRP or to the control group (CG) receiving PRP alone. Mean change in best-corrected visual acuity (BCVA), contrast sensitivity (CS) and central macular thickness (CMT) were compared at baseline and 1, 3 and 6 months after treatment. Results: Changes from baseline to 6 months showed in the SG an increased in the BCVA by + 3.4 letters (p= 0.006) with a decrease in CMT by - 47.6um (p < 0.001). In the CG, a decrease by - 3.4 letters (p = 0.04) and an decrease by -3.8um (p= 0.96). Regarding the CS in the SG, there was an improvement compared to baseline for the sixth month in the 1.5 (p < 0.001) and 3.0 cycles (p = 0.023). The CG did not show significant results from baseline to month 6. Conclusion: Intravitreal RBZ associated with PRP can be an effective treatment in eyes with non-high risk PDR and DME

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