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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.
81

Efeitos dos isômeros conjugados do ácido linoleico sobre a peroxidação lipídica em ratos / Effects of conjugated linoleic acid isomers on lipid peroxidation in rats

Carvalho, Eliane Bonifácio Teixeira de 02 December 2011 (has links)
Ácidos graxos conjugados (AGCs) é o termo geral para descrever os isômeros posicionais e geométricos dos ácidos graxos poliinsaturados com duplas ligações conjugadas. Inúmeros efeitos benéficos para a saúde como: anti-cancerígeno, anti-aterogênicos, anti-adipogênicos e anti-inflamatórios, tem sido atribuídos ao consumo dos AGCs. Entretanto, estudos sobre os efeitos dos AGCs no organismo ainda são inconclusivos e por isso o interesse em pesquisas visando a sua participação em processos fisiológicos. O objetivo deste estudo foi avaliar em ratos o efeito dos isômeros conjugados do ácido linoleico (9cis, 11trans e 10trans, 12cis) sobre o perfil lipídico tecidual e sua influência sobre parâmetros bioquímicos em processos oxidativos. Não foi possível detectar a atividade antioxidante in vitro dos CLAs. Os resultados obtidos demonstraram que o FFA-CLA foi capaz de reagir apenas com o radical DPPH. No experimento in vivo uma mistura comercial dos isômeros (9cis, 11trans e 10trans, 12 cis) foi utilizada como fonte de CLAs, e a influência da suplementação desses isômeros, foi avaliada e comparada com um grupo controle suplementado com água e com grupos experimentais suplementados com óleo de soja. O primeiro experimento foi realizado com animais Wistar saudáveis e teve duração de 40 dias, as amostras de ácidos graxos livres de CLAs, (FFACLAs) e óleo de soja foram fornecidas aos animais por meio de entubação orogástrica nas concentrações de 1%, 2% e 4% em relação ao consumo diário de dieta, o grupo controle recebeu 1% de água. A suplementação da dieta dos animais com os CLAs leva ao aumento nos níveis de triglicérides, mas não interfere nos parâmetros de estresse oxidativo, embora haja incorporação dose-dependente nos tecidos hepático, muscular e adiposo, não foram observadas alterações no volume das células adiposas, e na área e diâmetro do tecido muscular. No segundo experimento, com duração de 21 dias, ao avaliar o efeito da suplementação na dose de 2% de CLAs em ratos Wistar induzidos a peroxidação, pelo tratamento com tetracloreto de carbono. Pôde-se observar efeitos hepatoprotetor, dos CLAs atribuídos a sua prevenção na peroxidação lipídica e ao aumento da atividade das enzimas catalase (CAT), glutatina redutase (GR) e glutationa reduzida (GSH). / Conjugated fatty acids (CFAs) is the general term to describe positional and geometric isomers of polyunsaturated fatty acids with conjugated double bonds. Many beneficial health effects such as anti-cancer, anti-atherogenic, anti-adipogenic and anti-inflammatory, has been attributed to the consumption of the CFAs. However, studies on the effects of the CFAs in the body are still inconclusive and therefore the interest in research aimed at their participation in processes physiological. The objective of this study was to evaluate in rats the effect of conjugated linoleic acid isomers (9cis, 11trans and 10trans, 12cis) on lipid profile tissue and its effect on biochemical parameters in oxidative processes. It was not possible to detect the in vitro antioxidant activity of CLAs. The results showed that the free fatty acids of CLAs (FFA-CLAs) was able to react only with the DPPH radical. In in vivo experiment a commercial mixture of isomers (9cis, 11trans and 10trans, 12cis) was used as a source of CLAs and the influence of supplementation of these isomers was evaluated and compared with a control group supplemented with water and experimental groups supplemented with soybean oil. The first experiment was conducted with healthy Wistar and lasted 40 days, samples of FFA-CLA and soybean oil were delivered to animals via orogastric intubation at concentrations of 1%, 2 % and 4% in relation to daily diet, the control group received 1% water. Supplementing the diet with CLAs leads to increased levels of triglycerides, but does not interfere with oxidative stress parameters, although there is a dose-dependent incorporation into liver tissue, muscle and fat, no changes were observed in the volume of fat cells, and in the area and diameter of muscle tissue. In the second experiment, lasting 21 days, to evaluate the effect of supplementation at a dose of 2% of CLAs in Wistar, tha peroxidation induced by treatment with carbon tetrachloride. Could be observed hepatoprotective effects, attributed to the CLAs prevention lipid peroxidation and increased activity of the enzymes catalase (CAT), glutathione reductase (GR) and glutathione reduzida (GSH).
82

Protective effects of seaweeds against liver injury caused by carbon tetrachloride and trichloroethylene in rats.

January 2000 (has links)
Wong Chun-kwan. / Thesis submitted in: December 1999. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 127-137). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgments --- p.viii / Tables of Contents --- p.ix / List of Figures --- p.xv / List of Tables --- p.xxvi / Chapter Chapter 1: --- INTRODUCTION --- p.1 / Chapter Chapter 2: --- LITERATURE REVIEW --- p.8 / Chapter 2.1 --- Toxicology --- p.8 / Chapter 2.1.1 --- Acute toxicity test --- p.8 / Chapter 2.1.2 --- Biochemical Analysis --- p.9 / Chapter 2.1.3 --- Organ weights --- p.10 / Chapter 2.2 --- Histology --- p.11 / Chapter 2.2.1 --- Light Microscope --- p.11 / Chapter 2.2.2 --- Electron Microscopy --- p.11 / Chapter 2.3 --- Tissue injury --- p.12 / Chapter 2.3.1 --- Free-radical mechanisms --- p.12 / Chapter 2.3.2 --- Lipid peroxidation --- p.13 / Chapter 2.4 --- Carbon tetrachloride (CC14) --- p.14 / Chapter 2.4.1 --- Mechanisms of carbon tetrachloride toxicity --- p.15 / Chapter 2.5 --- Trichloroethylene (TCE) --- p.18 / Chapter 2.5.1 --- Mechanisms of trichloroethylene toxicity --- p.21 / Chapter 2.6 --- Dimethyl sulfoxide (DMSO) --- p.25 / Chapter 2.7 --- N-acetylcysteine (NAC) --- p.27 / Chapter Chapter 3: --- MATERIALS AND METHODS --- p.28 / Chapter 3.1 --- Materials --- p.28 / Chapter 3.2 --- Methods --- p.31 / Chapter 3.2.1 --- Acute hepatotoxicity test on aqueous seaweed extracts --- p.31 / Chapter 3.2.1.1 --- Preparation of aqueous extracts of seaweed --- p.31 / Chapter 3.2.1.2 --- Experimental protocol --- p.31 / Chapter 3.2.1.3 --- Biochemical assays --- p.32 / Chapter 3.2.1.4 --- Organ weights --- p.36 / Chapter 3.2.1.5 --- Histopathological examination --- p.36 / Chapter 3.2.1.6 --- Statistical analysis --- p.36 / Chapter 3.2.2 --- Curative and preventive tests of seaweed aqueous extracts against the CCl4-induced hepatotoxicity --- p.37 / Chapter 3.2.2.1 --- Preparation of aqueous extracts of seaweed --- p.37 / Chapter 3.2.2.2 --- Experimental protocol --- p.37 / Chapter 3.2.2.3 --- Biochemical assays --- p.39 / Chapter 3.2.2.4 --- Organ weights --- p.39 / Chapter 3.2.2.5 --- Histopathological examination --- p.40 / Chapter 3.2.2.6 --- Statistical analysis --- p.41 / Chapter 3.2.3 --- Acute hepatotoxicity test of TCE in rats by oral and intraperitoneal routes --- p.42 / Chapter 3.2.3.1 --- Experimental protocol --- p.42 / Chapter 3.2.3.2 --- Biochemical assays --- p.43 / Chapter 3.2.3.3 --- Organ weights --- p.43 / Chapter 3.2.3.4 --- Histopathological examination --- p.44 / Chapter 3.2.3.5 --- Statistical analysis --- p.44 / Chapter 3.2.4 --- Curative and preventive tests of seaweed aqueous extracts against the TCE effective dose-induced toxicity --- p.44 / Chapter 3.2.4.1 --- Preparation of aqueous extracts of seaweed --- p.44 / Chapter 3.2.4.2 --- Experimental protocol --- p.45 / Chapter 3.2.4.3 --- Biochemical assays --- p.46 / Chapter 3.2.4.4 --- Organ weights --- p.46 / Chapter 3.2.4.5 --- Histopathological examination --- p.46 / Chapter 3.2.5 --- Antidotal effects of dimethyl sulfoxide (DMSO) and N-acetylcysteine (NAC) against CC14- and TCE- induced poisoning in rats --- p.47 / Chapter 3.2.5.1 --- Experimental protocol --- p.47 / Chapter 3.2.5.2 --- Biochemical assays --- p.48 / Chapter 3.2.5.3 --- Organ weights --- p.48 / Chapter 3.2.5.4 --- Histopathological examination --- p.49 / Chapter 3.2.6 --- Hepatoprotective effect of seaweeds' methanol extract against CC14- and TCE-induced poisoning in rats --- p.49 / Chapter 3.2.6.1 --- Preparation of methanol extracts of seaweed --- p.49 / Chapter 3.2.6.2 --- Experimental protocol --- p.50 / Chapter 3.2.6.3 --- Biochemical assays --- p.52 / Chapter 3.2.6.4 --- Organ weights --- p.52 / Chapter 3.2.6.5 --- Histopathological examination --- p.53 / Chapter Chapter 4 --- RESULTS --- p.54 / Chapter 4.1 --- Acute hepatotoxicity test on aqueous seaweed extracts --- p.54 / Chapter 4.1.1 --- The biochemical assays of the serum transaminase activity --- p.54 / Chapter 4.1.2 --- The organ weight (Aqueous seaweed crude extracts) --- p.56 / Chapter 4.2 --- Curative and preventive tests of seaweed aqueous extracts against the CCl4-induced hepatotoxicity --- p.58 / Chapter 4.2.1 --- The biochemical assays of the serum transaminase activity (Curative) --- p.58 / Chapter 4.2.2 --- The organ weight (Curative) --- p.60 / Chapter 4.2.3 --- The biochemical assays of the serum transaminase activity (Preventive) --- p.62 / Chapter 4.2.4 --- The organ weight (Preventive) --- p.64 / Chapter 4.3 --- Acute hepatotoxicity test of TCE in rats by oral and intraperitoneal routes --- p.66 / Chapter 4.3.1 --- Oral route --- p.66 / Chapter 4.3.1.1 --- One-time oral route --- p.66 / Chapter 4.3.1.2 --- Two-time oral route --- p.66 / Chapter 4.3.2 --- Intraperitoneal route --- p.66 / Chapter 4.3.3 --- Time course of the effective dose of 20% TCE in i.p. route --- p.67 / Chapter 4.4 --- Curative and preventive tests of seaweed aqueous extracts against the TCE effective dose-induced toxicity --- p.12 / Chapter 4.4.1 --- The biochemical assays of the serum transaminase activity (Curative) --- p.72 / Chapter 4.4.2 --- The organ weight (Curative) --- p.74 / Chapter 4.4.3 --- The biochemical assays of the serum transaminase activity (Preventive) --- p.76 / Chapter 4.4.4 --- The organ weight (Preventive) --- p.78 / Chapter 4.5 --- Antidotal effects of dimethyl sulfoxide (DMSO) and N-acetylcysteine (NAC) against CC14- and TCE-induced poisoning in rats --- p.80 / Chapter 4.5.1 --- The biochemical assays of the serum transaminase activity (Curative) --- p.80 / Chapter 4.5.2 --- The organ weight (Curative) --- p.82 / Chapter 4.5.3 --- The biochemical assays of the serum transaminase activity (Preventive) --- p.84 / Chapter 4.5.4 --- The organ weight (Preventive) --- p.86 / Chapter 4.6 --- Hepatoprotective effect of methanol extract of seaweed against CC14- and TCE-induced poisoning in rats --- p.88 / Chapter 4.6.1 --- The biochemical assays of the serum transaminase activity (Curative) --- p.88 / Chapter 4.6.2 --- The organ weight (Curative) --- p.89 / Chapter 4.7 --- Histopathological examinations --- p.90 / Chapter 4.7.1 --- Acute hepatotoxicity test on aqueous seaweed extracts --- p.91 / Chapter 4.7.2 --- Curative and preventive tests of seaweed aqueous extracts against the CC14-induced hepatotoxicity --- p.92 / Chapter 4.7.3 --- Acute hepatotoxicity test of TCE in rats by oral and intraperitoneal routes --- p.99 / Chapter 4.7.4 --- Curative and preventive tests of seaweed aqueous extracts against the TCE effective dose-induced toxicity --- p.100 / Chapter 4.7.5 --- Antidotal effects of dimethyl sulfoxide (DMSO) and N-acetylcysteine (NAC) against CC14- and TCE-induced poisoning in rats --- p.100 / Chapter 4.7.6 --- Hepatoprotective effect of methanol extract of seaweed against CC14- and TCE-induced poisoning in rats --- p.102 / Chapter Chapter 5 --- DISCUSSION --- p.106 / Chapter Chapter 6 --- CONCLUSION --- p.124 / REFERENCES --- p.127 / APPENDIX --- p.138
83

Low-Energy Electron Induced Processes in Molecular Thin Films Condensed on Silicon and Titanium Dioxide Surfaces

Lane, Christopher Don 09 April 2007 (has links)
The focus of the presented research is to examine the fundamental physics and chemistry of low-energy electron-stimulated reactions on adsorbate covered single crystal surfaces. Specifically, condensed SiCl₄ on the Si(111) surface and condensed H₂O on the TiO₂ (110) surface have been studied. By varying adsorbate film thicknesses, the coupling strength of the target molecule to the substrate and surrounding media dictates the progression of the electron induced reactions. To investigate the electron interactions with SiCl₄ on the Si(111) surface, desorbing cations and neutrals were detected via time of flight mass spectrometry (ToF-MS) where neutral chlorine atoms were ionized using a resonance enhanced multi-photon ionization (REMPI) technique. Structure in the cation and neutral yields were assigned to molecular excitations. At an incident electron energy of 10 eV, a resonance structure in the neutral yields was attributed to a negative ion resonance and observed in thick and thin films of SiCl₄. With monoenergetic electrons, specific surface reactions can be controlled which have implications for film growth, surface patterning and masking, and etching. For the H₂O/TiO₂ (110) system, the water interactions with the TiO₂ surface are revealed through the strong electron induced reaction dependencies on the water coverage. Understanding the nonthermal reaction landscape of H₂O on the TiO₂ (110) surface is crucial for developing the system as a catalytic source of hydrogen. The electron-stimulated oxidation of the TiO₂ (110) surface and electron induced sputtering of H ₂O was investigated. Irradiation of water films ([coverage]< 3 ML) oxidized the TiO₂ (110) surface similarly as surface oxidation via O₂ deposition. Each H₂O molecule in the first monolayer seems to be a target for the incoming electron initiating the oxidation. However, water coverages greater than a monolayer limited the oxidation process. The electron-stimulated desorption and sputtering yields of water from the TiO₂ (110) surface were measured as a function of water coverage. Surprisingly, the amount of water sputtered from the surface is nonlinearly dependent on water coverage.
84

Applications of Molecular Dynamics Techniques and Spectroscopic Theories to Aqueous Interfaces

Green, Anthony 31 August 2010 (has links)
The primary goal of spectroscopy is to obtain molecularly detailed information about the system under study. Sum frequency generation (SFG) vibrational spectroscopy is a nonlinear optical technique that is highly interface specific, and is therefore a powerful tool for understanding interfacial structure and dynamics. SFG is a second order, electronically nonresonant, polarization experiment and is consequently dipole forbidden in isotropic media such as a bulk liquid. Interfaces, however, serve to break the symmetry and produce a signal. Theoretical approximations to vibrational spectra of O-H stretching at aqueous interfaces are constructed using time correlation function (TCF) and instantaneous normal mode (INM) methods. Detailed comparisons of theoretical models and spectra are made with those obtained experimentally in an effort to establish that our molecular dynamics (MD) methods can reliably depict the system of interest. The computational results presented demonstrate the potential of these methods to accurately describe fundamentally important systems on a molecular level.
85

Estudo do potencial terapêutico de células mononucleares de medula óssea em lesões hepáticas crônicas em camundongos / Estudo do potencial terapêutico de células mononucleares de medula óssea em lesões hepáticas crônicas em camundongos

Oliveira, Sheilla Andrade de January 2007 (has links)
Submitted by Ana Maria Fiscina Sampaio (fiscina@bahia.fiocruz.br) on 2012-08-29T20:29:44Z No. of bitstreams: 1 Sheilla Andrade deOliveira. Estudo do potencial terapêutico de células mononucleares de medula óssea em lesões hepáticas crônicas em camundongos - UFBA-FIOCRUZ-CPqGM - Tese Doutorado.pdf: 16762445 bytes, checksum: f804f2624774de877295c8841f4ff9c1 (MD5) / Made available in DSpace on 2012-08-29T20:29:44Z (GMT). No. of bitstreams: 1 Sheilla Andrade deOliveira. Estudo do potencial terapêutico de células mononucleares de medula óssea em lesões hepáticas crônicas em camundongos - UFBA-FIOCRUZ-CPqGM - Tese Doutorado.pdf: 16762445 bytes, checksum: f804f2624774de877295c8841f4ff9c1 (MD5) Previous issue date: 2007 / Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, Bahia, Brasil / O potencial terapêutico das células-tronco em doenças hepáticas vem sendo investigado. Estudos em modelos animais têm servido de base para a realização de ensaios clínicos utilizando células de medula óssea. Embora os resultados iniciais venham sendo bastante promissores, os mecanismos envolvidos na melhora hepática ainda não estão claros e novas avaliações em modelos experimentais se fazem necessárias. O objetivo da presente investigação foi avaliar a eficácia terapêutica de células mononucleares de medula óssea em doenças hepáticas crônicas. Inicialmente estabeleceu-se cirrose hepática no camundongo C57Bl/6, pela administração de uma solução de 20% de tetracloreto de carbono (CCI4) diluído em azeite de oliva combinado com 5% de etanol (EtOR) na água. Neste estudo observamos que, após seis meses de administração dos agentes hepatotóxicos, ocorre o desenvolvimento de lesões crônicas características de cirrose hepática. O segundo modelo utilizado foi o da infecção crônica pelo Schistosoma mansoni. Uma vez estabelecidas as lesões hepáticas crônicas nos animais, os estímulos "lesivos foram retirados e células mononucleares de medula óssea (3xl07) obtidas de tíbia e fêmures de camundongos transgênicos para proteína fluorescente verde (GFP) foram infundidas. A avaliação da capacidade migratória das células infundidas, bem como das alterações ocorridas após a terapia celular foi avaliada por meio de métodos histológicos, de imunofluorescência, morfológicos e imunológicos no tecido hepático. Após a terapia celular, observamos, nos dois modelos de fibrose hepática analisados, que as células GFP+ infundidas foram capazes de migrar e permanecer nas áreas de lesão do fígado. Inicialmente estas células apresentam formas arredondadas sem adentrar o tecido fibroso. Posteriormente, estas células tendem a invadir o tecido fibroso e assumem formas fusiformes. Uma redução do tecido fibroso foi verificada no 2° mês pós-terapia, em todos os grupos que receberam a terapia celular tanto nas áreas de fibrose septal e portal, quanto nas áreas dos granulomas. Os níveis de TGF-B no tecido hepático estavam diminuídos, após a terapia celular. O número de células ovais, conhecidas como células-tronco do fígado, estava aumentado no parênquima hepático após terapia celular. Os animais esquistossomóticos tratados com células de medula óssea recuperaram parcialmente a produção de albumina, quando comparado aos animais infectados. As observações sobre a terapia celular nos dois modelos de lesão crônica dos fígados avaliados nos permitem concluir que o transplante de células mononucleares de medula óssea diminui as alterações teciduais decorrentes de agressões crônicas ao fígado e reforçam a utilização deste tratamento para pacientes portadores de lesões hepáticas crônicas. / The therapeutic potential of stem cells on chronic liver diseases has been widely investigated. Based on results obtained mainly in studies using experimental models of acute liver injury, phase I clinical trials have already been carried out in patients with chronic liver diseases using therapy with bone marrow cells. Although the initial results were promising, the mechanisms involved on improvement of hepatic function are not clear and new evaluations with experimental models akin to human chronic liver diseases are needed. The object of the present investigation was the evaluation of the therapeutic efficacy of bone marrow mononuclear cells in chronic hepatic disease models. InitialIy, a mouse model of hepatic cirrhosis was induced in C57BI/6 mice by administration of 20% carbon tetrachloride solution (CCI4) diluted in olive oil combined with 5% ethanol (EtOH) in water was established. In this study we observed the development of chronic lesions characteristic of cirrhosis afier at least 6 months of administration of the hepatotoxic agents. The second model used was hepatic fibrosis caused by chronic infection by Schistosoma mansoni. Once the chronic lesions were established, the lesion stimulus was suspended and bone marrow mononuclear cells (3x I 07) obtained from tibiae and femurs of green fluorescence protein (GFP) transgenic mice were administered. The migratory capacity of the administered celIs, as well as the alterations occurring afier the celI therapy, was evaluated by histological, immunofluorescence, morphological and immunological methods in the liver tissue. After cell therapy in both hepatic fibrosis models it was observed that administered GFP+ cells were able to migrate and remain on hepatic lesion areas. Initially those celIs presented an oval shape outside thc fibrous tissue. At latter timepoints, those cells invadcd the fibrous tissue and acquired a fusifonll shape. A reduction of fibrosis was verified after the second month oftherapy in alI groups that received the celI therapy in the granuloma areas, as welI as in areas of septal and frontal fibrosis. The levels of TGF-~ were lower after the cell therapy, with statistical significance only in schistossomotic animaIs. The number of oval cells, known as liver stem cells, was increased in hepatic parenchyma afier cell therapy. The schistossomotic animaIs treated with bone marrow celIs recovered partialIy the production of albumin when compared to infected controls. Based on our observations about cell therapy in both models of chronic liver diseases evaluated we conc1ude that bone marrow mononuclear cell transplantation decreases tissue alterations caused by chronic aggressions to the liver and reinforce the use of this therapy in patients with chronic liver lesions.
86

Efeitos dos isômeros conjugados do ácido linoleico sobre a peroxidação lipídica em ratos / Effects of conjugated linoleic acid isomers on lipid peroxidation in rats

Eliane Bonifácio Teixeira de Carvalho 02 December 2011 (has links)
Ácidos graxos conjugados (AGCs) é o termo geral para descrever os isômeros posicionais e geométricos dos ácidos graxos poliinsaturados com duplas ligações conjugadas. Inúmeros efeitos benéficos para a saúde como: anti-cancerígeno, anti-aterogênicos, anti-adipogênicos e anti-inflamatórios, tem sido atribuídos ao consumo dos AGCs. Entretanto, estudos sobre os efeitos dos AGCs no organismo ainda são inconclusivos e por isso o interesse em pesquisas visando a sua participação em processos fisiológicos. O objetivo deste estudo foi avaliar em ratos o efeito dos isômeros conjugados do ácido linoleico (9cis, 11trans e 10trans, 12cis) sobre o perfil lipídico tecidual e sua influência sobre parâmetros bioquímicos em processos oxidativos. Não foi possível detectar a atividade antioxidante in vitro dos CLAs. Os resultados obtidos demonstraram que o FFA-CLA foi capaz de reagir apenas com o radical DPPH. No experimento in vivo uma mistura comercial dos isômeros (9cis, 11trans e 10trans, 12 cis) foi utilizada como fonte de CLAs, e a influência da suplementação desses isômeros, foi avaliada e comparada com um grupo controle suplementado com água e com grupos experimentais suplementados com óleo de soja. O primeiro experimento foi realizado com animais Wistar saudáveis e teve duração de 40 dias, as amostras de ácidos graxos livres de CLAs, (FFACLAs) e óleo de soja foram fornecidas aos animais por meio de entubação orogástrica nas concentrações de 1%, 2% e 4% em relação ao consumo diário de dieta, o grupo controle recebeu 1% de água. A suplementação da dieta dos animais com os CLAs leva ao aumento nos níveis de triglicérides, mas não interfere nos parâmetros de estresse oxidativo, embora haja incorporação dose-dependente nos tecidos hepático, muscular e adiposo, não foram observadas alterações no volume das células adiposas, e na área e diâmetro do tecido muscular. No segundo experimento, com duração de 21 dias, ao avaliar o efeito da suplementação na dose de 2% de CLAs em ratos Wistar induzidos a peroxidação, pelo tratamento com tetracloreto de carbono. Pôde-se observar efeitos hepatoprotetor, dos CLAs atribuídos a sua prevenção na peroxidação lipídica e ao aumento da atividade das enzimas catalase (CAT), glutatina redutase (GR) e glutationa reduzida (GSH). / Conjugated fatty acids (CFAs) is the general term to describe positional and geometric isomers of polyunsaturated fatty acids with conjugated double bonds. Many beneficial health effects such as anti-cancer, anti-atherogenic, anti-adipogenic and anti-inflammatory, has been attributed to the consumption of the CFAs. However, studies on the effects of the CFAs in the body are still inconclusive and therefore the interest in research aimed at their participation in processes physiological. The objective of this study was to evaluate in rats the effect of conjugated linoleic acid isomers (9cis, 11trans and 10trans, 12cis) on lipid profile tissue and its effect on biochemical parameters in oxidative processes. It was not possible to detect the in vitro antioxidant activity of CLAs. The results showed that the free fatty acids of CLAs (FFA-CLAs) was able to react only with the DPPH radical. In in vivo experiment a commercial mixture of isomers (9cis, 11trans and 10trans, 12cis) was used as a source of CLAs and the influence of supplementation of these isomers was evaluated and compared with a control group supplemented with water and experimental groups supplemented with soybean oil. The first experiment was conducted with healthy Wistar and lasted 40 days, samples of FFA-CLA and soybean oil were delivered to animals via orogastric intubation at concentrations of 1%, 2 % and 4% in relation to daily diet, the control group received 1% water. Supplementing the diet with CLAs leads to increased levels of triglycerides, but does not interfere with oxidative stress parameters, although there is a dose-dependent incorporation into liver tissue, muscle and fat, no changes were observed in the volume of fat cells, and in the area and diameter of muscle tissue. In the second experiment, lasting 21 days, to evaluate the effect of supplementation at a dose of 2% of CLAs in Wistar, tha peroxidation induced by treatment with carbon tetrachloride. Could be observed hepatoprotective effects, attributed to the CLAs prevention lipid peroxidation and increased activity of the enzymes catalase (CAT), glutathione reductase (GR) and glutathione reduzida (GSH).
87

Efeito Bidens Pilosa contra intoxicação induzida por tetracloreto de carbono em ratos Wistar / Effect of Bidens Pilosa against Carbon Tetrachloride-induced toxicity in wistar rats

PEGORARO, Cristiane Martinez Ruiz 05 March 2018 (has links)
Submitted by Adriana Martinez (amartinez@unoeste.br) on 2018-05-10T22:56:59Z No. of bitstreams: 1 Cristiane.pdf: 2390262 bytes, checksum: 25e1f95e171ca5f09f8ad8d90cc4b3d9 (MD5) / Made available in DSpace on 2018-05-10T22:56:59Z (GMT). No. of bitstreams: 1 Cristiane.pdf: 2390262 bytes, checksum: 25e1f95e171ca5f09f8ad8d90cc4b3d9 (MD5) Previous issue date: 2018-03-05 / Carbon tetrachloride (CCl4) is a xenobiotic that can induce injury by the formation of free radicals. When administered it is distributed and deposited in organs such as liver, brain, kidney, lung and heart. Since ancient times, medicinal plants have been of great importance in human health. According to the World Health Organization, about 80% of the world's population uses medicinal herbs as the first health care. Bidens pilosa (BP), popularly known as “Picão”, is a plant native to South America. BP has been used over the years to treat many diseases, such as inflammation, immune disorders, digestive diseases, infectious diseases, cancers, metabolic syndrome, wounds and liver diseases. BP has constituents with antioxidant activity, such as flavonoids. Objective: The aim of this study was to evaluate if the topical and oral treatment with BP have a protective effect against the carbon tetrachloride (CCl4)-induced toxicity. Material and methods: We used 56 male Wistar rats divided into 6 groups: A (n = 10): CCl4 only; B (n = 10): CCl4 + oral aqueous extract of BP; C (n = 10): CCl4 and topical BP (daily shower/1minute); D (n = 10): CCl4 and oral and topical aqueous extract (daily bath/1minute) BP; E (n = 8): oral aqueous extract of BP; F (n = 8): olive oil. The dose of CCl4 and olive oil was 1 mL solution/kg intraperitoneally 2 weight times/week and oral BP dose was 0.5mL/100g by gavage daily for 10 weeks. Blood samples were collected for hepatic and renal function tests and fragments of liver, spleen, pancreas, kidney and small and large intestine for histopathological analysis. Results: Statistical differences between group A and the other groups were observed in the following parameters: GGT (gamma glutamyl transpeptidase) (p = 0.017), albumin (p = 0.002), urea (p = 0.009) and creatinine 0.009), hepatic inflammation (p = 0.0001), renal tubular lesion (p <0.05) and inflammation of the small intestinal mucosa (p = 0.0001) between the BP groups and the untreated group. Conclusion: BP was effective in protecting the hepatic, renal and intestinal toxic effects of carbon tetrachloride, and combined (oral and topical) use showed the best protective effect. / O tetracloreto de carbono (CCl4) é um xenobiótico que pode induzir lesão pela formação de radicais livres. Quando administrado é distribuído e depositado em órgãos como: fígado, cérebro, rim, pulmão e coração. Desde a antiguidade, as plantas medicinais têm apresentado grande importância na saúde humana. Segundo a Organização Mundial de Saúde, cerca de 80% da população mundial utilizam ervas medicinais como primeiros cuidados de saúde. A Bidens pilosa (BP), popularmente denominada de “Picão”, é uma planta originária da América do Sul. A BP, ao longo dos anos, tem sido empregada no tratamento de muitas doenças, tais como: inflamação, distúrbios imunológicos, doenças digestivas, doenças infecciosas, cânceres, síndrome metabólica, feridas e hepatopatias. A BP possui constituintes com atividade antioxidante, como os flavonoides. Objetivo: O objetivo deste estudo foi avaliar se o tratamento tópico e por via oral com BP tem efeito protetor contra a intoxicação induzida pelo CCl4. Material e métodos: Utilizaram-se 56 ratos Wistar, machos, distribuídos em 6 grupos: A (n=10): CCl4; B (n=10): CCl4 + extrato aquoso oral de BP; C (n=10): CCl4 e BP tópica (banho diário/1minuto); D (n=10): CCl4 e extrato aquoso oral e tópico (banho diário/1minuto) de BP; E (n=8): extrato aquoso oral de BP; F (n=8): óleo de oliva. A dose utilizada de CCl4 e de óleo de oliva foi de 1mL de solução/Kg de peso intraperitoneal 2 vezes/semana e a de BP oral foi 0,5mL/100g de peso por gavagem diariamente por 10 semanas. Foi coletado sangue para realização de provas de função hepática e renal e fragmentos de: fígado, baço, pâncreas, rim e intestino delgado e grosso para análise histopatológica. Resultados: Observou-se diferença estatística entre o grupo A e os demais grupos estudados nos seguintes parâmetros: GGT (gama glutamil transpeptidase) (p= 0,017), albumina (p=0,002), uréia (p= 0,009) e creatinina (p= 0,009), inflamação hepática (p=0,0001), lesão tubular renal (p<0,05) e inflamação da mucosa do intestino delgado (p=0,0001) entre os grupos tratados com BP e o não tratado. Conclusão: A BP se mostrou efetiva para proteção aos efeitos tóxicos hepáticos, renais e intestinais do tetracloreto de carbono, e o uso combinado (oral e tópico), mostrou o melhor efeito protetor.
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Lipid peroxidation <i>in vivo</i> : Evaluation and application of methods for measurement

Södergren, Eva January 2000 (has links)
<p>Lipid peroxidation is thought to be an important factor in the pathophysiology of a number of diseases and in the process of ageing, but its measurement <i>in vivo</i> has been difficult. The aim of this thesis was to evaluate methods for measurement of lipid peroxidation <i>in vivo</i> that are suitable for clinical investigations, and to apply these methods in animal and human studies investigating basal conditions and situations associated with increased lipid peroxidation.</p><p>The ferrous oxidation in xylenol orange assay for quantification of total plasma lipid hydroperoxides was re-evaluated regarding sample handling and storage. It was shown to be a useful tool for analyses of fresh but not stored plasma samples.</p><p>A methodology for measurement of the total amount (sum of free and esterified) of an F<sub>2</sub>-isoprostane, 8-iso-prostaglandin F<sub>2α</sub>, in tissues using alkaline hydrolysis in combination with an existing radioimmunoassay was developed. High levels of 8-iso-prostaglandin F<sub>2α</sub> in rat liver tissue were quantified by this technique both at basal conditions and in an experimental model of increased lipid peroxidation induced by carbon tetrachloride.</p><p>Supplementation with vitamin E to rats decreased both non-enzymatic and enzymatic lipid peroxidation as measured by 8-iso-prostaglandin F<sub>2α</sub> and a major prostaglandin F<sub>2α</sub> metabolite. This was verified both in the urine at basal conditions, and in the urine and liver tissue after carbon tetrachloride induced lipid peroxidation.</p><p>In a randomised cross-over study in humans, a rapeseed oil-based diet with an increased proportion of easily oxidised polyunsaturated fatty acids was compared to a control diet rich in saturated fats. The rapeseed oil-based diet did not seem to increase the degree of lipid peroxidation in plasma and urine as measured by 8-iso-prostaglandin F<sub>2α</sub>, hydroperoxides and malondialdehyde, presumably due to a sufficient content of antioxidants in the rapeseed oil diet.</p><p>In conclusion, the simultaneous measurement of several biomarkers of lipid peroxidation is a promising approach for future studies investigating the possible role of lipid peroxidation <i>in vivo</i> under basal conditions and in the pathology of diseases.</p>
89

Lipid peroxidation in vivo : Evaluation and application of methods for measurement

Södergren, Eva January 2000 (has links)
Lipid peroxidation is thought to be an important factor in the pathophysiology of a number of diseases and in the process of ageing, but its measurement in vivo has been difficult. The aim of this thesis was to evaluate methods for measurement of lipid peroxidation in vivo that are suitable for clinical investigations, and to apply these methods in animal and human studies investigating basal conditions and situations associated with increased lipid peroxidation. The ferrous oxidation in xylenol orange assay for quantification of total plasma lipid hydroperoxides was re-evaluated regarding sample handling and storage. It was shown to be a useful tool for analyses of fresh but not stored plasma samples. A methodology for measurement of the total amount (sum of free and esterified) of an F2-isoprostane, 8-iso-prostaglandin F2α, in tissues using alkaline hydrolysis in combination with an existing radioimmunoassay was developed. High levels of 8-iso-prostaglandin F2α in rat liver tissue were quantified by this technique both at basal conditions and in an experimental model of increased lipid peroxidation induced by carbon tetrachloride. Supplementation with vitamin E to rats decreased both non-enzymatic and enzymatic lipid peroxidation as measured by 8-iso-prostaglandin F2α and a major prostaglandin F2α metabolite. This was verified both in the urine at basal conditions, and in the urine and liver tissue after carbon tetrachloride induced lipid peroxidation. In a randomised cross-over study in humans, a rapeseed oil-based diet with an increased proportion of easily oxidised polyunsaturated fatty acids was compared to a control diet rich in saturated fats. The rapeseed oil-based diet did not seem to increase the degree of lipid peroxidation in plasma and urine as measured by 8-iso-prostaglandin F2α, hydroperoxides and malondialdehyde, presumably due to a sufficient content of antioxidants in the rapeseed oil diet. In conclusion, the simultaneous measurement of several biomarkers of lipid peroxidation is a promising approach for future studies investigating the possible role of lipid peroxidation in vivo under basal conditions and in the pathology of diseases.
90

Chlorination of Titanium Oxycarbide and Oxycarbonitride

Adipuri, Andrew, Materials Science & Engineering, Faculty of Science, UNSW January 2009 (has links)
The project undertook a systematic study of chlorination of titanium oxycarbide and oxycarbonitride with the aim to develop further understanding of kinetics and mechanisms of the chlorination reactions. The project studied titania, ilmenite ores, and synthetic rutile reduced by carbon in argon and nitrogen and chlorinated at different temperatures, gas flow rates and compositions. Chlorination of titanium suboxides, iron and impurities in ilmenite was also examined. Chlorination of titanium oxycarbide Ti(O,C) or oxycarbonitride Ti(O,C,N) can be implemented at 200 to 400 deg.C, while the commercial chlorination process in the production of titanium metal or titania pigment requires 800 to 1100 deg.C. This makes chlorination of Ti(O,C) or Ti(O,C,N) an attractive technology in processing of titanium minerals. Chlorination reaction is strongly exothermal, which increased the sample temperature up to 200 deg.C above the furnace temperature. The chlorination of Ti(O,C) or Ti(O,C,N) was ignited at 150 deg.C to 200 deg.C depending on the sample composition. Their chlorination at 235 deg.C to 400 deg.C was close to completion in less than 30 min. The chlorination rate of titanium oxycarbide or oxycarbonitride increased with increasing gas flow rate. Sample composition had a significant effect on the extent of chlorination. The optimum results were obtained for titanium oxycarbide or oxycarbonitride produced with carbon to titania molar ratio of 2.5; these samples contained no detectable excess of carbon or unreduced titanium suboxides. In chlorination of reduced ilmenite ores and synthetic rutile, Ti(O,C) or Ti(O,C,N), metallic iron and Ti2O3 were chlorinated. The rate and extent of chlorination of titanium increased with increasing carbon to TiO2 ratio. Chlorination of Ti2O3 was slow relative to Ti(O,C) or Ti(O,C,N) and iron; chlorination of impurity oxides such as MgO, SiO2 and Al2O3 was not observed. The project also examined chlorination of Ti(O,C) or Ti(O,C,N) in ilmenite ore and synthetic rutile after removal of iron, which was achieved by aerated leaching of reduced samples in heated flask containing 0.37 M of ammonium chloride solution. Iron removal from the ilmenite ore or synthetic rutile resulted in higher rate and extent of chlorination of titanium oxycarbide or oxycarbonitride.

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