Submitted by Marcos Anselmo (marcos.anselmo@unipampa.edu.br) on 2016-09-21T17:52:14Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Ana Paula Gai Fuão.pdf: 1243240 bytes, checksum: d40fbf45a1852ec6eebfa3e33bb9bcc3 (MD5) / Approved for entry into archive by Marcos Anselmo (marcos.anselmo@unipampa.edu.br) on 2016-09-21T17:53:51Z (GMT) No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Ana Paula Gai Fuão.pdf: 1243240 bytes, checksum: d40fbf45a1852ec6eebfa3e33bb9bcc3 (MD5) / Made available in DSpace on 2016-09-21T17:53:51Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Ana Paula Gai Fuão.pdf: 1243240 bytes, checksum: d40fbf45a1852ec6eebfa3e33bb9bcc3 (MD5) Previous issue date: 2014-08-21 / A hipertensão arterial sistêmica é fundamentada como uma condição clínica multifatorial caracterizada por níveis elevados e sustentados de pressão arterial. A progressão da doença está intimamente ligada com alterações estruturais e funcionais cardíacas e vasculares além de promover danos em alguns órgãos alvo, como os rins, cérebro, além das alterações metabólicas, que produzem um aumento sensível nos riscos de doenças cardiovasculares. De acordo com a Sociedade Brasileira de Cardiologia a hipertensão arterial sistêmica apresenta uma alta prevalência e baixas taxas de controle, tornando-a um dos mais importantes problemas de saúde pública no Brasil. O uso de plantas medicinais para fins terapêuticos é bastante antigo e muitas vezes seu uso é absolutamente empírico, sem nenhum estudo científico que embase essa prática. A Blepharocalyx salicifolius, conhecida como Murta, apresenta várias utilidades terapêuticas baseadas no conhecimento popular, entre elas o uso como digestivo, antibacteriano, antiespasmódico e anti-hipertensivo, entre outros. No presente trabalho foi avaliado o efeito hipotensor do extrato aquoso da B. salicifolius em ratos normotensos, e analisado, através do uso do L-NAME, da losartan e do hexametônio, qual seria seu possível mecanismo de ação. A avaliação dos efeitos hemodinâmicos foi realizada em ratos wistar normotensos, anestesiados com uretana (1,4 mg/Kg i.p.) e via canulação da artéria carótida (para a verificação da PAS, PAD e FC) e da veia jugular (para administração do extrato e drogas). O primeiro protocolo foi realizado para verificação do efeito do extrato sobre os parâmetros hemodinâmicos, utilizando uma curva dose-crescente do extrato (10, 25, 50, 75 e 100 mg/Kg) via intravenosa individualmente (cada grupo contendo 6 animais). O extrato aquoso foi administrado após 30 minutos de estabilização no equipamento, e permaneceram por 60 min. O segundo protocolo foi para avaliar alguns dos possíveis mecanismos envolvidos na resposta hipotensora. Foram utilizados: um inibidor da óxido nítrico sintase - L-NAME (L-NG-nitroarginina metil ester) (30 mg/kg); um antagonista do receptor AT1 - Losartan, (10 mg/Kg), e um bloqueador ganglionar, Hexamêtonio (20mg/Kg). As drogas foram administradas após a estabilização, sendo feito uma nova estabilização para a administração do extrato (concentração 7,5 mg/Kg; volume de 200 μL) e registros realizados por 60 min. O extrato aquoso da B. salicifolius mostrou-se um potente hipotensor, reduzindo a pressão arterial de forma dose-independente, já que as quedas foram semelhantes indiferentemente da dose usada, sem provocar alterações na frequência cardíaca. Na avaliação dos possíveis mecanismos de ação foi observado que o bloqueio do receptor AT1 e administrado o extrato aquoso não houve modificação na hipotensão provocada pelo Losartan bem como após o bloqueio ganglionar com o hexametônio. Já quando induzida a hipertensão por L-NAME, o extrato aquoso causou queda de pressão arterial, sugerindo que a via do óxido nítrico não estaria envolvida. Estes resultados evidenciam pela primeira vez que o efeito hipotensor da administração aguda do extrato aquoso de Blepharocalyx salicifolius, possa ser via bloqueio dos receptores de angiotensina II tipo I e pela possível diminuição da resposta autonômica simpática. / Hypertension is finds as a multifactorial clinical condition characterized by high and sustained levels of blood pressure. Disease progression are intimately linked with structural and functional cardiac and vascular changes, promoting some damage in target organs such as the kidneys, brain, in addition to metabolic changes that produce a significant increase in the risk of cardiovascular diseases. According to the Brazilian Society of Cardiology, hypertension has a high prevalence and low control rates, making it one of the most important public health problems in Brazil. The use of medicinal plants for therapeutic purposes is quite old and often its use is completely empirical, no scientific study that basement this practice. Blepharocalyx salicifolius, known as Murta, has several therapeutic utilities based on popular knowledge, including use as digestive, antibacterial, antispasmodic and antihypertensive, among others. The present study evaluated the hypotensive effect of aqueous extract of B. salicifolius in normotensive rats and analyzed with L-NAME, the losartan and hexamethonium, which would be its possible mechanism of action. The evaluation of the hemodynamic effects was perform in normotensive Wistar rats, anesthetized with urethane (1.4 mg / kg i.p.) and cannulated in the carotid artery (for verification of SBP, DBP and HR) and the jugular vein (for administration of the extract and drugs). The first protocol was performed to verify the effect of the extract on the hemodynamic parameters using a dose increasing curve of the extract (10, 25, 50, 75 and 100 mg/kg) intravenously individually (each group containing six animals). The administration of the aqueous extract was after 30 minutes of stabilization in the equipment, and they remained for 60 min. The second protocol was to evaluate some of the possible mechanisms involved in the hypotensive response. Were used: an inhibitor of nitric oxide synthase - L-NAME (L-NG-L-nitroarginine methyl ester) (30 mg / kg); AT1 receptor antagonist - losartan (10 mg / kg), and a ganglionic blocker - hexamethonium (20mg/kg). Drug administration was performed after stabilization, performing a new stabilization for the administration of the extract and records kept for 60 min. The aqueous extract of B. salicifolius proved a potent hypotensive effect, reducing blood pressure in a dose-independent way since the declines were similar regardless of the dose used, and without effect on heart rate. In evaluation of the possible mechanism of action it was observed, when the AT1 receptor were blockade and the extract was administrated, that there was no change in blood pressure caused by losartan as after ganglionic blockage. When hypertension was induced by L-NAME, the extract caused arterial pressure low, suggesting that the nitric oxide pathway could not be involved. These results show for the first time that the hypotensive effect of acute administration of Blepharocalyx salicifolius aqueous extract may be by blockade of angiotensin II type 1 receptors and the possible reduction in sympathetic autonomic response.

Kalanchoe pinnata (Lam.) Pers. (Crassulaceae) é uma espécie muito empregada na medicina tradicional no Brasil e em outras partes do mundo, especialmente Índia, países da África e China. É indicada popularmente para diversos fins incluindo o tratamento de úlceras gástricas. A análise fitoquímica revelou a presença de vários constituintes, em especial os flavonoides. O tratamento de úlcera gástrica convencional apresenta diversos efeitos colaterais e, na maioria das vezes, não evita a recidiva da lesão. Dessa maneira, é interessante encontrar uma terapêutica mais segura e efetiva. Com o objetivo de avaliar a segurança, foi realizado ensaio de citotoxicidade do extrato bruto, in vitro, com valor de IC50 igual a 0,926 mg/mL, sendo possível predizer um valor de LD50 (1341,46 mg/kg). Já em relação ao ensaio de citotoxicidade, in vitro, da fração acetato de etila não foi encontrado um valor de IC50. Resultados de fototoxicidade, in vitro, mostraram que o extrato bruto e fração acetato de etila de K. pinnata não possuem potencial fototóxico. A contagem microbiana na droga vegetal para bactérias aeróbias/mesófilas foi de 6,9 x 104 UFC/g e a contagem de bolores e leveduras foi de 2,4 x 103 UFC/g, ambos valores dentro do limite estabelecido pela OMS. Análise de endotoxinas também foi realizada para o extrato bruto (<4,0.105 UE/kg) e fração acetato de etila (<2,7.105 EU/kg) de K. pinnata. Referente à fitoquímica, diversos flavonoides foram identificados no extrato bruto e fração acetato de etila de K. pinnata. Paralelamente ao estudo fitoquímico foi verificado que a atividade gastroprotetora do extrato bruto envolve a ação das prostaglandinas e grupamentos sulfidrila. Já o mecanismo de gastroproteção da fração acetato de etila é dependente de prostaglandinas e óxido nítrico. A atividade cicatrizante do extrato bruto de K. pinnata também foi avaliada. De acordo com os resultados macroscópicos, as doses de 200mg/kg e 400 mg/kg reduziram a área de lesão, com uma taxa de 33% e 39%, respectivamente, após 7 dias de tratamento (p<0,05). Análise histológica dos grupos tratados com o extrato bruto (200 e 400 mg/kg) indicou melhor recuperação da lesão, verificada pela regeneração da mucosa gástrica e pelo restabelecimento da arquitetura glandular. As enzimas antioxidantes (catalase, superóxido dismutase e glutationa peroxidase) e a expressão de VEGF foram avaliadas no mecanismo de cicatrização de úlceras gástricas. Os resultados mostraram que a atividade antiulcerogênica foi mediada pela ação antioxidante da enzima SOD. Não foi evidenciado in vivo o aumento da expressão de VEGF e nem o sequestro do radical peroxil nos animais tratados com o extrato bruto. Os resultados dos ensaios in vitro (ORAC) mostraram uma maior capacidade de sequestro de radicais peroxil da fração acetato de etila (1192,35 ± 112,61 &#181;mol equivalente de Trolox/g de amostra seca) quando comparado com o extrato bruto (431,32 ± 7,17 &#181;mol equivalente de Trolox/g de amostra seca). A atividade anti Helicobacter pylori também foi avaliada, no entanto, o extrato bruto não apresentou atividade anti H.pylori. Ademais, o extrato bruto demonstrou um potencial anti-inflamatório, pois foi observada uma redução nos níveis de TNF-&#945; e L-selectina, após o tratamento em neutrófilos estimulados com LPS. Analisando os resultados sugere-se que K. pinnata possui um potencial terapêutico no combate de úlceras gástricas e possivelmente, anti-inflamatório, sendo que os flavonoides podem estar relacionados com o efeito biológico observado. / Kalanchoe pinnata (Lam.) Pers. (Crassulaceae) is a commonly used species in traditional medicine in Brazil and in other parts of the world, especially India, Africa and China, for the treatment of various diseases, including gastric ulcers. Phytochemical analysis revealed the presence of several constituents in this plant, especially flavonoids. The available pharmaceutical products to treat peptic ulcer have several side effects and, in most cases, do not prevent recurrence of the gastric lesions. Therefore, it is important to find a safer and more effective therapy. In order to evaluate safety, the in vitro cytotoxicity assay of crude extract from K. pinnata was performed. The IC50 value was 0,926 mg/mL corresponding to LD50 value (1341, 46 mg/kg). It was not determined IC50 value in vitro cytotoxicity assay for ethyl acetate fraction from K. pinnata. Neither the crude extract nor ethyl acetate fraction from K. pinnata showed phototoxicity. Microbial counting was performed on the K. pinnata-based drug in order to investigate microbiological contamination. The microbial count for aerobic / mesophilic bacteria was 6.9 x 104 CFU/g, and yeast count was 2.4 x 103 CFU/g, both values in agreement with the limits established by WHO. Endotoxin analysis was also performed for the crude extract (<4,0.105 UE/kg) and for ethyl acetate fraction (<2,7.105 UE/kg) from K. pinnata. In the phytochemical analysis several flavonoids were identified in the crude extract and ethyl acetate fraction of K. pinnata. In parallel to the phytochemical study, it was verified that the gastroprotective activity of the crude extract of K. pinnata involved prostaglandins and sulfhydril compounds. On the other hand, the mechanism of gastroprotection of the ethyl acetate fraction of K. pinnata is dependent on prostaglandins and nitric oxide. The healing activity of the crude extract of K. pinnata was also evaluated. According to the macroscopic results the dose of 200 mg/kg and 400mg/kg reduced the injury area, with a rate of 33% and 39%, respectively, after 7 days of treatment (p <0.05). Histological analysis showed regeneration of the gastric mucosa and re-establishment of the glandular architecture in groups treated with the crude extract (200 and 400 mg/kg). Antioxidant enzymes (catalase, superoxide dismutase and glutathione peroxidase) and VEGF expression were evaluated in the mechanism of gastric ulcer healing. The results showed that the antiulcerogenic activity was mediated by SOD. It was not demonstrated an increase in VEGF expression and nor in the in vivo sequestration of the peroxyl radical in the animals treated with crude extract. The results of in vitro assay (ORAC) showed a greater sequestering of peroxyl radical to the ethyl acetate fraction (1192,35 ± 112,61 &#181;mol equivalent of Trolox/g of ethyl acetate fraction) when compared to the crude extract (431,32 ± 7,17 &#181;mol equivalent of Trolox/g of crude extract) of K. pinnata. The anti Helicobacter pylori activity was also evaluated; however, the crude extract did not show anti H. pylori activity. However, the crude extract of K. pinnata demonstrated an anti-inflammatory potential, because TNF-&#945; and L-selectin levels were reduced after treatment in LPS-stimulated neutrophils. The analysis of the results suggests that K. pinnata has a therapeutic potential against gastric ulcers and possible anti-inflammatory properties, and the flavonoids may be linked to the biological effect.

Application of chemotherapeutic agents in current cancer treatment has been limited by adverse effects as poor selectivity results in systemic toxicity; most chemotherapy approaches also experience inherited or acquired drug resistance which lead to reduced treatment outcome. Research efforts have focused on the discovery of novel chemotherapies that overcome the limitations mentioned above. Ru(II) polypyridyl complexes with anti-cancer properties have been extensively studied as traditional cytotoxic agents and photodynamic therapy agents due to their photophysical and photochemical characteristics. Most research has focused on the design of Ru(II) polypyridyl complexes that have affinities to nucleic acids as inspired by the classic small molecule metal complex cisplatin. Though modifying the structures of ligands on the ruthenium metal center, the hydrophilicity, charge state and photochemical properties can be tuned, resulting to Ru(II) polypyridyl complexes that act through cellular targets other than DNA. Understanding the mechanism of action and identifying functional targets remain the challenging and complex research topic in the design and study of novel medication or candidates. With the development of semi-high throughput cytological profiling in a bacterial system, rapid investigation of the mechanism of action can be achieved to distinguish anti-cancer agents which possess different mechanisms of actions. Ru(II) polypyridyl complexes with different scaffolds have been studied and suggested to have anti-cancer properties through DNA damage response, and/or translational inhibition.

A simple, quick, and sensitive radiometric assay for glutaminase has been established. This assay uses L-(U-14C)-glutamine as the substrate and measures the 14co2 produced when the reaction is coupled to glutamate decarboxylase. An efficient purification procedure for cow brain glutaminase has also been developed; the yield is 12%. Steps include acetone extraction, ammonium sulfate fractionation, calcium phosphate gel treatment, and differential gel filtration on Sepharose 4B. The final preparation has a specific activity of 385 Mmole/min/mg and shows a single protein band on polyacrylamide gel electrophoresis in sodium dodecyl sulfate; this band corresponds to a subunit molecular weight of 82,000. Polyacrylamide gel electrophoresis studies did not reveal any impurities; the enzyme activity coincided with the protein staining. This enzyme is stable between pH 7.5 and 9.2 and has maximal activity around 8.8. The activity of glutaminase appears to be independent of the nature of the buffer with which it was equilibrated before it was assayed. The enzyme absolutely requires phosphate for activity; the dependence is sigmoidal and has a Hill coefficient of 2.2. The phosphate concentration that gives half maximal velocity is 50 mM. At 0.2 M potassium phosphate (pH 8.8), the dependence of activity on glutamine is hyperbolic; the observed Kgln is 17 mM. Neither amnonium ion (0.1 M) nor citrate, succinate, or glutarate (57 mM) inhibit the enzyme activity. Glutamate inhibits competitively with respect to glutamine. Phosphate affects both Kgln and Kglu the same way. A radioactivity exchange study was not able to detect incorporation of 14C-glutamate into 14 c-glutamine. The results are consistent with a model in which ammonia is released irreversibly from the enzyme-substrate complex and is the first product to be released.

Bibliography: leaves 234-257. Three separate clinical studies in organ transplant recipients are presented. The aims are to examine fundamental questions regarding the clinically and economically important pharmokinetic interaction between diltiazem and cyclosporin, an interaction widely utilised in organ transplantation. The data contained should assist the development of soundly based policies that will ensure a benefit exists before a sparing agent is coprescribed, and that the lowest effective dose of sparing agent is used.

The intracranial system consists of three main basic components - the brain, the blood and the cerebrospinal fluid. The physiological processes of each of these individual components are complex and they are closely related to each other. Understanding them is important to explain the mechanisms behind neurostructural disorders such as hydrocephalus. This research project consists of three interrelated studies, which examine the mechanical properties of the brain at the macroscopic level, the mechanics of the brain during hydrocephalus and the study of fluid hydrodynamics in both the normal and hydrocephalic ventricles. The first of these characterizes the porous properties of the brain tissues. Results from this study show that the elastic modulus of the white matter is approximately 350Pa. The permeability of the tissue is similar to what has been previously reported in the literature and is of the order of 10-12m4/Ns. Information presented here is useful for the computational modeling of hydrocephalus using finite element analysis. The second study consists of a three dimensional finite element brain model. The mechanical properties of the brain found from the previous studies were used in the construction of this model. Results from this study have implications for mechanics behind the neurological dysfunction as observed in the hydrocephalic patient. Stress fields in the tissues predicted by the model presented in this study closely match the distribution of histological damage, focused in the white matter. The last study models the cerebrospinal fluid hydrodynamics in both the normal and abnormal ventricular system. The models created in this study were used to understand the pressure in the ventricular compartments. In this study, the hydrodynamic changes that occur in the cerebral ventricular system due to restrictions of the fluid flow at different locations of the cerebral aqueduct were determined. Information presented in this study may be important in the design of more effective shunts. The pressure that is associated with the fluid flow in the ventricles is only of the order of a few Pascals. This suggests that large transmantle pressure gradient may not be present in hydrocephalus.

E. coli O157:H7 has been found to survive in dry sausages and cause disease. Isothiocyanates have been studied for their capacity to eliminate pathogens from foods and are attractive from the consumer perspective because of their natural origin. There is a need to better understand how isothiocyanates kill microorganisms and their behaviour in food matrices. It was found that glutathione and cysteine naturally present in meat can react with AIT, forming a conjugate with no or low bactericidal activity against an E. coli O157:H7. In addition, AIT presented higher anti-E. coli activity at lower pH values; therefore, it should be more efficient in acid foods. AIT was also found to inhibit the activity of thioredoxin reductase and acetate kinase; hence, enzymatic inhibition may represent a way in which AIT kills E. coli O157:H7. Mustard powder is used as a spice (active myrosinase) and/or binder (inactive myrosinase) in meat products. Both of these powders killed E. coli O157:H7 in dry fermented sausage. This was not expected since the powder lacking myrosinase is not able to produce isothiocyanates. Starter cultures and E. coli were found to consume significant amounts of glucosinolates. Pediococcus pentosaceus UM 121P and Staphylococcus carnosus UM 123M (higher myrosinase-like activity) were compared against P. pentosaceus UM 116P + S. carnosus UM 109M for their ability in reducing E. coli viability in dry sausage. Sausage batches containing powders of hot mustard, cold mustard, autoclaved mustard and no powder were prepared. Both pairs of starters yielded similar results. Reduction >5 log CFU/g of E. coli O157:H7 occurred after 31 d for hot powder and 38 d for cold powder; there was no reduction in the control. E. coli O157:H7 itself has greater effect on glucosinolate degradation than either pair of starters, which may be more important in determining its survival. Autoclaved powder caused >5 log CFU/g reduction after 18 d. This may be the result of synergistic/additive interaction among E. coli O157:H7 myrosinase-like activity, the presence of newly formed/released antimicrobials in the autoclaved powder and the multiple hurdles present in the dry sausage. Autoclaved mustard powder has potential as a novel food ingredient for the meat industry.

E. coli O157:H7 has been found to survive in dry sausages and cause disease. Isothiocyanates have been studied for their capacity to eliminate pathogens from foods and are attractive from the consumer perspective because of their natural origin. There is a need to better understand how isothiocyanates kill microorganisms and their behaviour in food matrices. It was found that glutathione and cysteine naturally present in meat can react with AIT, forming a conjugate with no or low bactericidal activity against an E. coli O157:H7. In addition, AIT presented higher anti-E. coli activity at lower pH values; therefore, it should be more efficient in acid foods. AIT was also found to inhibit the activity of thioredoxin reductase and acetate kinase; hence, enzymatic inhibition may represent a way in which AIT kills E. coli O157:H7. Mustard powder is used as a spice (active myrosinase) and/or binder (inactive myrosinase) in meat products. Both of these powders killed E. coli O157:H7 in dry fermented sausage. This was not expected since the powder lacking myrosinase is not able to produce isothiocyanates. Starter cultures and E. coli were found to consume significant amounts of glucosinolates. Pediococcus pentosaceus UM 121P and Staphylococcus carnosus UM 123M (higher myrosinase-like activity) were compared against P. pentosaceus UM 116P + S. carnosus UM 109M for their ability in reducing E. coli viability in dry sausage. Sausage batches containing powders of hot mustard, cold mustard, autoclaved mustard and no powder were prepared. Both pairs of starters yielded similar results. Reduction >5 log CFU/g of E. coli O157:H7 occurred after 31 d for hot powder and 38 d for cold powder; there was no reduction in the control. E. coli O157:H7 itself has greater effect on glucosinolate degradation than either pair of starters, which may be more important in determining its survival. Autoclaved powder caused >5 log CFU/g reduction after 18 d. This may be the result of synergistic/additive interaction among E. coli O157:H7 myrosinase-like activity, the presence of newly formed/released antimicrobials in the autoclaved powder and the multiple hurdles present in the dry sausage. Autoclaved mustard powder has potential as a novel food ingredient for the meat industry.

Bibliography: leaves 234-257. / xi, 277 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Three separate clinical studies in organ transplant recipients are presented. The aims are to examine fundamental questions regarding the clinically and economically important pharmokinetic interaction between diltiazem and cyclosporin, an interaction widely utilised in organ transplantation. The data contained should assist the development of soundly based policies that will ensure a benefit exists before a sparing agent is coprescribed, and that the lowest effective dose of sparing agent is used. / Thesis (Ph.D.)--University of Adelaide, Dept. of Clinical and Experimental Pharmacology, 2001

Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references (leaves 145-158). Also available on the Internet.