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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.
531

The interaction between abiotic and biotic stress in Arabidopsis thaliana

Alzwiy, Ibrahim A. Mohamed January 2013 (has links)
Plants are continuously exposed to different abiotic and biotic stresses in their natural environment. Their capacity to survive depends on the capacity to perceive external signal and quality amount a defence response for protection from the stress perceived. The purpose of this project was to study the impact of combined abiotic stress and biotic stress on the outcome of the disease inducing Arabidopsis thaliana – Pseudomonas syringae interaction. This study included a focus on the role of ABA in these interactions and also whether 3´-O-β D- ribofuranosyl adenosine (hereafter it called ‘400’ compound), a novel adenosine derived compound induced during compatible interactions, was involved. The later involved the targetted disruption of a putative 400 biosynthetic pathway involving analysis of knockout mutants of enzymes; APD-ribose diphosphatase NAD binding / hydrolases of the NUDIX class, glucosyl transferases, ribosyltransferases, a ribose-phosphate pyrophosphokinase3 and galactosyltransferases. Unfortunately, none of these targeted interventions modified the host response to Pseudomonas infection, nor altered levels of 400 in challenged leaves. The primary research investigated the interaction between abiotic and biotic stresses in Arabidopsis plants focussing on the modulation of plant defence against multiple, and possibly antagonistic, stress responses and the role plant hormones play in this process. We showed that high light caused enhanced susceptibility to the already virulent Pseudomonas syringae DC3000pvsp61. The pathways contributing to this enhanced susceptibility were largely ABA independent. Subsequent characterization of transgenic lines expressing the soluble Arabidopsis abscisic acid receptors, PYRABACTIN RESISTANCE1-LIKE4-6 provided compelling evidence for a role for these receptors in DC3000 virulence strategies, but they contribute to a lesser extent to the enhanced susceptibility under high light. This was corroborated genetically by using mutants of the immediately downstream targets of PYLs, the type two protein phosphatase, specifically the triple mutant hab1-1/abi2-1/abi1-2. A number of epitope and fluorescent constructs were generated to facilitate future studies of the role of ABA signaling. Targetted profiling suggested that SA dynamics were altered under DC3000 challenged Arabidopsis grown under high light. Furthermore, differential accumulation of flavonoids suggested these may also play a role in attenuating host defences under high light. Finally we provide evidence based on comparative analysis of that the photoreceptors phytochrome double mutant phyA-211/phyB-9 and cry1/cry2 behave antagonistically in Arabidopsis response to DC3000. Overall our studies support the conclusion that plants abiotic stress (HL) response takes precedence over biotic stress (DC3000) responses and that abiotic stress is detrimental to plant immunity. The luciferase transgenic PYL lines showed high level of expression of ClucP::PYL5 plant tissues challenged 2hpi of DC3000 (OD600: 0.15) in comparison with C1lucP::PYL6. This result opposes to what RT-PCR reported; which was that three PYLs genes display similar expression level at 6hpi of hrpA or 18hpi of DC3000. The epitope tags of CaMV::HA transgenic plants showed HA-tagged signal with stunted phenotype in a range of PYL4, 5 and 6 plants but none of the plants displayed any differences in susceptibility to DC3000. Although, RT-PCR assay showed high levels of expression in the three PYLs, 6hpi of hrpA but no signal was detected in B8eGFP::PYL5 transgenic line either followed the DC3000 and hrpA infection or by examined plant seedlings at early stages under confocal microscopy.
532

Aminopyrimidine derivatives as adenosine antagonists / Janke Kleynhans

Kleynhans, Janke January 2013 (has links)
Aims of this project - The aim of this study was to design and synthesise novel 2-aminopyrimidine derivatives as potential adenosine A1 and A2A receptor antagonists. Background and rationale - Parkinson’s disease is the second most common neurodegenerative disorder (after Alzheimer’s disease) and is characterised by the selective death of the dopaminergic neurons of the nigro-striatal pathway. Distinctive motor symptoms include bradykinesia, muscle rigidity and tremor, while non-motor symptoms, of which cognitive dysfunction is an example, also frequently occur. Current therapy provides symptomatic relief mainly by augmentation of dopaminergic signalling (levodopa, dopamine agonists, MAO and COMT enzyme inhibitors), but disease progression is not adequately addressed. New therapies that can prevent further neurodegeneration in addition to providing symptomatic relief are therefore urgently required. Adenosine has an important function as neuromodulator in the central nervous system. The adenosine A2A receptor in particular plays an essential role in the regulation of movement. This, coupled to the fact that it is uniquely distributed in the basal ganglia, contributes to its attractiveness as non-dopaminergic target in the treatment of movement disorders, such as Parkinson’s disease. The efficacy of adenosine receptor antagonists has been illustrated in animal models of Parkinson’s disease and several adenosine receptor antagonists have also reached clinical trials. The neuroprotective properties of adenosine A2A receptor antagonists are further attributed to their ability to modulate neuro-inflammation and decrease the release of the excitatory neurotransmitter glutamate, which is implicated in neurotoxicity. While adenosine A1 receptor antagonism has a synergistic effect on the motor effects of adenosine A2A receptor antagonism, it has the additional benefit of improving cognitive dysfunction, a cardinal non-motor symptom of Parkinson’s disease. Dual antagonism of adenosine A1 and A2A receptors therefore offers the potential of providing symptomatic relief as well as the neuroprotection so desperately needed in the clinical environment. Amino substituted heterocyclic scaffolds, such as those containing the 2-aminopyrimidine motif, have been shown to exhibit good efficacy as dual adenosine receptor antagonists. Since the structure activity relationships of 2-aminopyrimidines have not been comprehensively explored, it is in this regard that this study aimed to make a contribution. Results - Fourteen 2-aminopyrimidines were synthesised successfully over three steps, (although in low yields) and characterised by nuclear magnetic resonance and infrared spectroscopy, mass spectrometry, by determination of melting points and high performance liquid chromatography. Structure modifications explored included variation of the aromatic substituent on position 4, as well as variations in the substituents of the phenyl ring, present on position 6 of the pyrimidine ring. Radioligand binding assays were performed to determine the affinities of the synthesised compounds for the adenosine A1 and A2A receptor subtypes. Several high dual affinity derivatives were identified during this study; the compound with the highest affinity was 4-(5- methylthiophen-2-yl)-6-[3-(piperidine-1-carbonyl)phenyl]pyrimidin-2-amine (39f) with Ki values of 0.5 nM and 2.3 nM for the adenosine A2A and adenosine A1 receptors, respectively. A few general structure activity relationships were derived, which included: The effect of the aromatic substituent (position 4) on A2A affinity could be summarised (in order of declining affinity) as follows: 5-methylthiophene > phenyl > furan > pyridine > p-fluorophenyl > benzofuran. On the other hand, the effect of this substituent on A1 receptor affinity could be summarised (in order of declining affinity) as follows: phenyl > 5-methylthiophene > pfluorophenyl > benzofuran > pyridine. The affinities as exhibited by the methylthiophene derivatives 39f, 39h – 39j, further showed that while piperidine substitution (39f) resulted in optimal A2A and A1 affinity, pyrrolidine substitution (39j) was less favourable. Substitution at the 4ʹ position of the phenyl ring, as well as thiazole substitution, generally resulted in poor adenosine A1 and A2A receptor affinity. However, 4-[2-amino-6-(5-methylfuran-2-yl)pyrimidin- 4-yl]-N-(1,3-benzothiazol-2-yl)benzamide (39l) surprisingly demonstrated good affinity and selectivity for the adenosine A1 receptor. The results obtained during radioligand binding assays were rationalised by QSAR and molecular modelling (Discovery Studio 3.1, Accelrys) studies. The inverse relationship seen between log Ki (as indicator of affinity) and polar surface area, illustrated the importance of this physico-chemical property in the design of 2-aminopyrimidine A2A antagonists. The results from the docking study further showed that the orientation adopted by derivatives in the binding cavity (and particular hydrogen bonding to Asn 253 and Glu 169) is of importance. Results from the MTT cell viability assay indicated that none of the high affinity derivatives had a significant effect on cell viability at 1 μM, a concentration much higher than their Ki values. However, incorporation of the furan, benzofuran and p-fluorophenyl groups as aromatic substituent and a pyrrolidine as amine substituent, presented liabilities. Lastly, the haloperidol induced catalepsy assay (in rats) was used to give a preliminary indication of adenosine receptor antagonism or agonism. Compound 39f failed to reverse catalepsy under standard conditions, but showed some reversal after an increased time period. Indications therefore exist that 39f is an adenosine receptor antagonist that suffers from bioavailability issues. Compound (39c), 4-phenyl-6-[3-(piperidine-1- carbonyl)phenyl]pyrimidin-2-amine which also demonstrated promising affinity in the radioligand binding assays however showed a statistically significant reduction in catalepsy, indicating adenosine A2A receptor antagonism, and in vivo efficacy. Highly potent, dual affinity aminopyrimidine derivatives with acceptable toxicity profiles were identified in this study, with compound 39c demonstrating in vivo activity. The aim of designing and synthesising a promising dual adenosine A1/A2A receptor antagonist is therefore realised, with compound 39c as the most favourable example. / MSc (Pharmaceutical Chemistry), North-West University, Potchefstroom Campus, 2014
533

Nanoparticules d’Adénosine –Squalène et ischémie cérébrale : caractérisation du passage de la Barrière Hémato-Encéphalique, efficacité pharmacologique et théranostic / Squalenoyl-Adenosine Nanoparticles and cerebral ischémia : characterization of the passage of the Blood-Brain Barrier, pharmacological efficacy and theranostic

Gaudin, Alice 17 November 2014 (has links)
L’objectif de ces travaux de thèse, inscrits dans le projet ERC Advanced Grant «TERNANOMED», était de développer un nanomédicament squalèné à base d’adénosine (NPs d’AdSQ) pour le traitement des accidents vasculaires cérébraux et des traumatismes de la moelle épinière. La première partie de ce travail décrit la préparation et la caractérisation des NPs d’AdSQ, et la mise en évidence d’une activité thérapeutique spectaculaire dans des modèles pré-cliniques d’ischémie cérébrale et de neurotrauma. Afin de mieux comprendre le mécanisme d’action des NPs, la deuxième partie de cette thèse a été consacrée à l’étude détaillée de la transcytose des NPs à travers la barrière hémato-encéphalique, et a permis de démontrer le désassemblage des NPs au sein des cellules endothéliales. Cette étude confirme que l’action des NPs d’AdSQ résulte en premier lieu d’une activité vasculaire via l’amélioration de la microcirculation, et dans un second temps, permet la protection des neurones, vraisemblablement grâce au couplage neurovasculaire et à l’action pléiotropique et multi-cibles de l’adénosine. La troisième partie de ce travail de thèse avait pour but de décrire en détail le profil pharmacocinétique et la biodistribution des NPs d’AdSQ à l’aide de techniques innovantes de radiomarquage. Enfin, une dernière partie présente des résultats préliminaires sur le développement d’un outils théranostic via l’encapsulation d’USPIO comme agent de contraste IRM au sein des NPs d’AdSQ. Dans son ensemble, ce travail de thèse a permis d’établir les fondements de l’extension de la plateforme de «squalènisation» au traitement des pathologies du système nerveux central. / This PhD work, as a part of the ERC Advanced Grant project «TERNANOMED», aimed at developing a squalenoyl nanomedicine of adenosine (SQAd NAs), for the treatment of stroke and spinal cord injury (SCI). The first part of this research was dedicated to the preparation and characterization of SQAd NAs, and highlighted their dramatic therapeutic activity in pre-clinical models of cerebral ischemia and SCI. To further understand the mechanism of action of these NAs, the second part of this thesis was devoted to the detailed study of their transcytosis across the Blood-Brain Barrier. It was shown that the NAs were disassembled inside the endothelial cells, confirming that the pharmacological mechanism of the SQAd NAs action appeared to be a primary vascular protection via the improvement of microcirculation, leading to a secondary neuronal preservation, likely thanks to neurovascular coupling and to the pleiotropic multitargeted abilities of adenosine. The third part of this work aimed to describe the pharmacokinetic profile and tissue distribution of SQAd NAs, thanks to innovative techniques of radiolabeling. Finally, the fourth part presented preliminary results on the development of a theranostic tool, by incorporating USPIO as a MRI contrast agent inside the SQAd NAs. Overall, this PhD work established the foundation to the extension of the squalenoylation platform to the treatment of neurological diseases.
534

Papel protetor da quinase ativada por adenosina monofosfato (AMPK) na progressão e severidade da nefrite tubulointersticial experimental. / Protective role of adenosine monophosphate activated kinase (AMPK) on the progression and severity of experimental tubulointerstitial nephritis.

Macêdo, Marina Barguil 12 September 2017 (has links)
Objetivamos investigar o papel da quinase ativada por adenosina monofosfato (AMPK) na doença renal crônica. Induzimos nefrite túbulo-intersticial (NTI) em camundongos C57BL/6 e LyzM-cre AMPKflox/flox através de ração com adenina, e tratamos com metformina (Met) 200 mg/kg/dia. Avaliamos ainda o efeito da Met sobre a transição epitélio-mesenquimal (TEM) em células tubulares epiteliais renais murinas (linhagem MM55.K). Os C57BL/6 tratados apresentaram preservação da função renal; maior frequência de macrófagos (MØ) M1, em detrimento dos M2; e redução de marcadores de fibrose. Os LyzM-cre AMPK-/- não diferiram dos LyzM-cre AMPK+/+ quanto à intensidade da lesão, por a molécula já se encontrar infrarregulada na NTI. Contudo, ao serem tratados com Met, os LyzM-cre AMPK+/+ evoluíram melhor do que os não tratados, o mesmo não se verificando nos LyzM-cre AMPK-/-, sugerindo que a ação da Met nos MØ é dependente de AMPK. As MM55.K, após estímulo com Met, exibiram maior captação de glicose, expressão do transportador Glut-2, ativação da glicólise, e resistência à TEM. / We aimed to investigate the role of adenosine monophosphate activated kinase (AMPK) on chronic kidney disease. We induced tubulointerstitial nephritis (TIN) in C57BL/6 and LyzM-cre AMPKflox/flox mice by feeding them adenine diet, and then treating with metformin (Met) 200 mg/kg/day. We also evaluated the effect of Met on epithelium-to-mesenchyma transition (EMT) of murine epithelial renal tubular cells (lineage MM55.K). Met-treated C57BL/6 mice presented preserved kidney function, greater frequency of M1 macrophages (MØ) compared to M2 ones, and reduced markers of fibrosis. Disease severity on LyzM-cre AMPK-/- and AMPK+/+ mice did not differ, since the molecule was already downregulated on TIN. However, by treating them with Met, LyzM-cre AMPK+/+ improved in comparison to the non-treated mice. The same did not happen with LyzM-cre AMPK-/- mice, suggesting that Met effect on MØ is AMPK-dependent. MM55.K cells, after stimulus with Met, showed increased glucose uptake, greater expression of the transporter Glut-2, activation of glycolysis, and resistance to EMT.
535

Investigação do aumento endógeno de adenosina decorrente da administração do intermediário glicolítico D-Frutose-1,6-difosfato / Investigation of adenosine endogenous increase decurrent of D-Frutose-1,6-difosfato administration, a glycolytic intermediate.

Valerio, Daniel Augusto Rodrigues 31 July 2009 (has links)
D-Frutose-1,6-difosfato (F1,6BP), um intermediário altamente energético da via glicolítica, é descrito na literatura como portador de diversas atividades farmacológicas, contudo seu mecanismo de ação ainda não fora esclarecido. Dessa forma, a possível atividade anti-inflamatória da F1,6BP sobre diferentes modelos de inflamação e sua via de ação em camundongos foram averiguadas com enfoque na inibição da produção de citocinas e na elevação dos níveis endógenos de adenosina. A hipernocicepção mecânica foi avaliada por método eletrônico de pressão crescente em patas de camundongos, o ensaio cinéticocolorimétrico de mieloperoxidase (MPO) foi utilizado na avaliação da migração leucocitária para o tecido subcutâneo plantar, e a performance motora dos animais foi determinada pelo teste rota-rod. A quantificação de citocinas foi realizada por ELISA, enquanto a quantificação de adenosina foi obtida em cromatografia líquida de alta eficiência (CLAE) após validação laboratorial da metodologia segundo normas protocoladas pela ANVISA. O pré-tratamento de camundongos com F1,6BP reduziu a hipernocicepção induzida por injeção intraplantar de carragenina (45%), TNF-a (40%), IL-1B (46%), KC (33%), prostaglandina E2 (41%) e dopamina (55%). O tratamento com F1,6BP, no entanto, não alterou a produção de citocinas induzidas por carragenina (TNF-a, IL-1B e KC) e nem interferiu com a migração leucocitária para a região desafiada. Por outro lado, o efeito antinociceptivo da F1,6BP foi prevenido por tratamento sistêmico e local com antagonista de receptores A1 de adenosina (DPCPX) e o tratamento com adenosina apresentou efeitos similares os do tratamento com F1,6BP, sugerindo que o efeito da F1,6BP é mediado pela ação periférica da adenosina sobre receptores A1. Endossando isso, foi constatado por meio de cromatografia líquida de alta eficiência um aumento na concentração plasmática de adenosina em camundongos após administração de F1,6BP. Por conseguinte, a via de ação da F1,6BP parece ser dependente da produção de adenosina, mas não da modulação na produção de citocinas hipernociceptivas. A adenosina atua, então, perifericamente em receptores A1 inibindo a hipernocicepção, e a evidência farmacológica de que ela medeia a atividade da F1,6BP através dessa ação sobre receptores A1 foi corroborada por resultados in vivo que demonstram aumento dos níveis de adenosina decorrente da administração de F1,6BP. Em vista disso, esses resultados insinuam um possível potencial terapêutico da F1,6BP em reduzir a dor inflamatória. / D-Fructose-1,6-bisphosphate (F1,6BP), a high-energy glycolytic pathway intermediate, is reported to have a many pharmacologically effect, but its underlying mechanism of action in inflammation is incompletely understood. In this study, the aim was to examine the function of F1,6BP on cytokines and adenosine. Then, the possible F1,6BP anti-inflammatory activities in different models of inflammation and its mechanism of action in mice were addressed focusing inhibition of cytokine production or adenosine production enhancement. Mechanical hypernociception (decrease in the nociceptive threshold of animals) was evaluated by the electronic pressure meter test in mice, the myeloperoxidase (MPO) kineticcolorimetric assay was used to evaluate the leukocyte migration to the subcutaneous plantar tissue of mice hind paw, and mice motor performance were evaluated on the rota-rod test. The cytokines levels were measured by ELISA. Adenosine levels were determined by high performance liquid chromatography and this experimental procedure was validated according to ANVISA for this purpose. The pretreatment of mice with F1,6BP reduced the hypernociception induced by intraplantar injection of carrageenan (45%), TNF (40%), IL-1 (46%), KC (33%), prostaglandin E2 (41%) and dopamine (55%). However, FBP treatment did not alter carrageenin-induced cytokines (TNF-, IL-1 and KC) production or the leukocyte migration to the subcutaneous plantar tissue of mice hind paw. On the other hand, the antinociceptive effect of F1,6BP was prevented by systemic and local treatment with an adenosine A1 receptor antagonist (DPCPX) and adenosine treatment presented similar effect of F1,6BP, suggesting that F1,6BP effect is mediated by peripheral adenosine acting on A1 receptors. In agreement, the present work determined by high performance liquid chromatography that D-Fructose-1,6-bisphosphate administration increased the adenosine endogenous levels in the mice plasma. Therefore, F1,6BP mechanism of action seems dependent on adenosine production but not on modulation of hypernociceptive cytokine production. In turn, adenosine acts peripherally on A1 receptor inhibiting hypernociception. The pharmacological evidence that adenosine through activation of adenosine A1 receptor mediates the antinociceptive action of F1,6BP was supported by the finding that in vivo administration of F1,6BP increases the levels of adenosine in the blood samples. Thus, suggesting the treatment with F1,6BP as a possible therapeutic approach to reduce inflammatory pain.
536

Efeitos da 5-iodotubercidina em linhagens de melanoma humano parentais e resistentes ao inibidor de BRAF / Effects of 5-iodotubercidin on human melanoma lines of parental and resistant to the BRAF inhibitor

Stephanie Cristine Carvalho dos Santos 13 February 2019 (has links)
O melanoma é responsável por menos de 5% dos cânceres de pele, porém, 95% das mortes ocorrem devido a ocorrência de metástases. O melanoma metastático é refratário às terapias convencionais e rapidamente adquire resistência às terapias como as oncogene-dirigidas, como o inibidor de BRAF, da via de MAPK. Estudos prévios de screening in silico do nosso grupo, onde se utilizou as bases de dados TCGA e GEO, identificaram o gene adenosina quinase (ADK) como sendo diferencialmente expresso entre o melanoma invasivo e os nevus. A 5-iodotubercidina (5-ITu) é um potente inibidor farmacológico da ADK que dentre os diversos efeitos relatados na literatura destaca-se pelo potencial genotóxico. Os danos no DNA são os principais ativadores de checkpoint do ciclo celular, que levam a parada do ciclo celular transitória ou permanente, além de induzir morte celular, levando a hipótese de que ADK possa ser potencial agente anti-melanoma. Este trabalho objetivou avaliar a expressão do gene ADK em melanomas humanos e quimiorresistentes ao inibidor de BRAF (iBRAF), avaliou os impactos de 5-ITu sobre a proliferação, progressão do ciclo celular e morte celular e por fim avaliamos sua capacidade de aumentar a sensibilidade das células. Foi realizado PCR em tempo real para avaliar os níveis de expressão de mRNA de ADK em linhagens de melanoma e na cultura primária de melanócitos; a fim de avaliar a citotoxicidade de 5-ITu foram realizados os ensaios de exclusão por azul de tripan e de apoptose - Anexina V e PI e em modelo de esferoide, usando live/dead; também foi avaliada a influência de 5-ITu sobre a capacidade clonogênica e seus efeitos sobre a proliferação celular, a partir dos ensaios de ciclo celular e avaliação de marcadores de proliferação por imunofluorescência; as linhagens foram submetidas a diferentes regimes de tratamento com 5-ITu e o iBRAF, a fim de avaliar a curva de crescimento e a sensibilidade ao iBRAF por MTT níveis de expressão de mRNA de ADK maiores nas linhagens tumorais em relação aos melanócitos. 5-ITu mostrou-se capaz de inibir a proliferação (IC50) das linhagens de melanoma em concentrações de 1,9 a 3,5 µM. 5-ITu não foi capaz de induzir inviabilidade celular, apesar de reduzir a quantidade de células viáveis em todas as condições de tratamento, também não foi capaz de induzir aumento significativo de células apoptóticas, nem mesmo necróticas. No entanto, o tratamento com 5-ITu reduziu a capacidade clonogênica de linhagens de melanoma e promoveu parada de ciclo celular nas fases G1 e G2/M, levou ao aumento da população subG1. O tratamento com 5-ITu promoveu a redução da expressão de marcadores de proliferação, como ki67, e a combinação de tratamentos 5-ITu e iBraf foi capaz de aumentar o tempo de dobramento das linhagens de melanoma, embora tenha se mostrado incapaz de sensibilizar as células de melanoma ao tratamento com iBRAF. Desse modo, pode-se concluir que 5-ITu induz o efeito citostático e se mostra um potente agente antiproliferativo para melanoma parental e resistente. / Melanoma accounts for less than 5% of skin cancers, but 95% of deaths occur due to metastases. Metastatic melanoma is refractory to conventional therapies and rapidly acquires resistance to therapies such as oncogene-directed, such as the BRAF inhibitor, of the MAPK pathway. Previous studies of screening in silico of our group, using the databases TCGA and GEO, identified the adenosine kinase gene (ADK) as differentially expressed between invasive melanoma and nevus. 5-iodotubercidin (5-ITu) is a potent pharmacological inhibitor of ADK that among the several effects reported in the literature stands out for the genotoxic potential. DNA damage is the main activator of the cell cycle checkpoint, which leads to transient or permanent cell cycle arrest, in addition to inducing cell death, leading to the hypothesis that ADK may be a potential anti-melanoma agent. This work aimed to evaluate the expression of the ADK gene in human melanomas and chemoresistants to the BRAF inhibitor (iBRAF), evaluated the impacts of 5-ITu on proliferation, cell cycle progression and cell death and finally we evaluated its ability to increase the sensitivity of cells. Real-time PCR was performed to assess the levels of ADK mRNA expression in melanoma lines and primary melanocyte culture; in order to evaluate the cytotoxicity of 5-ITu, the trypan blue and apoptosis - Annexin V and PI exclusion and blue spheroid models were performed using live / dead; the influence of 5-ITu on the clonogenic capacity and its effects on cell proliferation, from the cell cycle assays and the evaluation of proliferation markers by immunofluorescence; the cell lines were submitted to different treatment regimens with 5-ITu and iBRAF in order to evaluate the growth curve and the sensitivity to iBRAF by MTT levels of mRNA expression of ADK higher in the tumor lines in relation to the melanocytes. 5-ITu was able to inhibit the proliferation (IC 50) of melanoma lines at concentrations of 1.9 to 3.5 181;M. 5-ITu was not able to induce cell non-viability, although it reduced the amount of viable cells in all treatment conditions, nor was it able to induce a significant increase in apoptotic or even necrotic cells. However, treatment with 5-ITu reduced the clonogenic capacity of melanoma cells and promoted cell cycle arrest in the G1 and G2 / M phases, leading to an increase in the subG1 population. Treatment with 5-ITu promotes the reduction of expression of proliferation markers, such as ki67, and the combination of 5-ITu and iBRAF treatments was able to increase the doubling time of melanoma cells, although it has been shown to be unable to sensitize melanoma cells to treatment with iBRAF. Thus, it can be concluded that 5-ITu induces the cytostatic effect and shows a potent antiproliferative agent for parental and resistant melanoma.
537

Hybrid Biological-Solid-State Sytems: Powering an Integrated Circuit from ATP

Roseman, Jared January 2016 (has links)
This thesis presents a novel hybrid biological solid-state system which makes use of biological components in an in-vitro environment to produce functionality incapable by CMOS circuits alone. A "biocell" comprised of lipids and ion pumps is mated to a CMOS IC in a compact configuration and the IC is powered solely from adenosine triphosphate (ATP), often referred to as the 'life energy currency.' The biocell is a fuel cell that produces a membrane potential in the presence of ATP which is used by the IC as an electrical power supply. The design represents the first of a new class of devices combining both biological and solid-state components, which exploit the unique properties of transmembrane proteins in engineered solid-state systems. This work also suggests that the richness of function of biological ion channels and pumps, functionality that is impossible to achieve in CMOS alone, may be exploited in systems that combine engineered transmembrane proteins as biological components integrated with solid-state devices.
538

Efeito da cafeína na detecção de isquemia à cintilografia de perfusão miocárdica associada ao estresse com adenosina / Effects of caffeine on ischemia detection in myocardial perfusion scyntigraphy induced by adenosine stress

Reis, Lais Vissotto Garchet Santos 14 December 2010 (has links)
A utilização da cintilografia de perfusão miocárdica (CPM) estava limitada a pacientes que podiam realizar algum tipo de exercício, para ampliarmos a disponibilidade clínica da CPM, vários protocolos com estresses farmacológicos foram desenvolvidos. A adenosina fármaco amplamente utilizado, potente vasodilatador coronariano, apresenta uma importante interação com outras substâncias que anatagonizam seus efeitos, o dipiridamol, alimentos com cafeína e derivados de xantinas. O tempo de suspensão de cafeína da dieta para o uso exógeno da adenosina na realização da CPM ainda não está definido. Para testar essa hipótese avaliamos a influência da abstinência de cafeína em 24h, 12h e 1h, através de sua dosagem sérica, antes do estresse farmacológico com adenosina e sua possível repercussão nas imagens da CPM e o efeito vasodilatador no sistema cardiovascular. Definimos como objetivo primário: comparar a presença e a extensão dos defeitos reversíveis da CPM verificados em pacientes com abstinência de café por 24 horas (E1) com as imagens da randomização com 1 hora e 12 horas (E2) sem cafeína e como objetivos secundários: avaliar a presença e intensidade dos paraefeitos, comportamento da frequência cardíaca e da pressão arterial sistêmica. Foram submetidos ao estresse farmacológico com adenosina 194 pacientes para a realização da CPM, dos quais 43 pacientes preencheram os critérios para a randomização (defeitos perfusionais transitórios na CPM com adenosina). Excluímos seis pacientes (13,9%), três (6,9%) se recusaram a realizar a fase da randomização e os outros três (6,9%) nos quais não houve consenso entre os observadores em relação aos defeitos de perfusionais transitórios. A média de idade dos 37 pacientes analisados foi de 61,4 ± 8,3 anos, sendo 21 pacientes do sexo masculino (56,8%). Na avaliação das imagens da CPM, não houve diferença entre as imagens obtidas no grupo E1 comparadas as imagens de 1 (2,0 ± 1,5) hora ou 12 (12,6 ± 3,1) horas sem cafeína (E2). As médias de cafeína sérica encontradas foram de 0,14 ± 0,17 mg/l no grupo E1 do E2 de 1 hora e 0,13 ± 0,24 mg/l no grupo E1 do E2 de 12 horas, na randomização de 1 hora de 1,97± 0,83 mg/l e de 12 horas de 1,51 ± 1,46 mg/l (E1 vs. E2: p < 0,001). Em relação à presença dos paraefeitos, ocorreram em 31 pacientes (83,7%) e os mais freqüentes foram: dor precordial atípica, cansaço e dor em região cervical. Não foram observadas diferenças em relação às freqüências absolutas e relativas na ocorrência de paraefeitos entre os grupos. A intensidade dos paraefeitos foi verificada através de análise subjetiva comparando os sintomas em relação aos exames. Notou-se que em 22 pacientes (59,4%), caracterizaram o estudo randomizado como bem melhor, ou melhor, que o de 24 horas. A pressão arterial sistêmica e a freqüência cardíaca também não apresentaram diferenças entre os grupos. Conclusões: Os resultados permitem inferir que o uso da cafeína ingerida 2 horas antes da realização da CPM com adenosina foi eficaz e segura, pois apesar da modificação da resposta vasodilatadora máxima alcançada, traduzida pela melhor tolerância do exame realizado com menos tempo de ausência de cafeína na dieta, não modificou o resultado final da CPM / Myocardial perfusion imaging (MPI) in the past was only available to patients who were able to perform some type of exercise. Many protocols were developed with pharmacologic stress in order to enlarge the clinical availability of myocardial perfusion imaging (MPI). Adenosine is widely used and a potent coronary vasodilator, exhibits a significant interaction with other substances which antagonize its effects, such as dipyridamole, food products containing caffeine and xanthine derivatives. We found no clear consensus as to the time between caffeine ingestion and a cardiovascular adenosine stress test. To test this hypothesis we evaluated the influence of 24-hour, 12-hour and 1-hour caffeine abstinence, by assessing plasma caffeine levels before adenosine pharmacological stress, the possible repercussions on MPI images and vasodilatory effects on the cardiovascular system. The primary endpoint was to compare the presence and extent of reversible myocardial perfusion defects found in patients with 24-hour abstinence from coffee (E1), with images from patients randomized to 1-hour or 12-hour caffeine abstinence (E2). As secondary endpoints we evaluated the presence and intensity of paraeffects, as well as heart rate and systemic arterial blood pressure behavior. For this purpose, 194 patients underwent pharmacological stress with adenosine for MPI, 43 of whom fulfilled criteria for randomization (patients with transient perfusion defects detected on adenosine MPI). Six patients were excluded (13.9%), three patients (6.9%) who refused to undergo randomization, and other three (6.9%) in whom the observers could not reach consensus regarding transient perfusion defects. Mean age for the 37 patients analyzed was 61.4 ± 8.3 years, 21 patients male (56.8%). In the evaluation of myocardial perfusion images, no differences were detected between images obtained in the 24-hour E1 arm, and those from 1 (2.0 ± 1.5) hour or 12 (12.6 ± 3.1) hours randomization E2. Mean plasma caffeine level was 0.14 ± 0.17 mg/l in group E1 of the 1-hour arm E2, and 0.13 ± 0.24 mg/l in group (E1) of the 12-hour arm (E2), respectively, compared with 1.97± 0.83 mg/l, in the 1-hour, and 1.51 ± 1.46 mg/l, in the 12-hour (E2) randomized arms (E1 vs. E2: p < 0.001). In the 31 patients (83.7%) with presence of paraeffects, the most frequent were: atypical precordial pain, tiredness and pain on cervical area. There were no differences in the absolute and relative frequency in the occurrence of paraeffects between groups. However, with respect to the intensity of pareffects, a subjective analysis was undertaken, comparing symptoms of two exams. which resulted in 22 patients (59.4%) ranking the randomized study a lot better, or better than the 24-hour one. The systemic blood pressure and the heart rate behavior also did not reveal any significant differences between groups. Conclusions: The results may imply that the use of caffeine ingested 2 hours prior to the CPM with adenosine was effective and safe, for despite the change in maximal vasodilator response achieved, manifested by better tolerance of the examination with less time in the absence of caffeine in the diet, did not change the final result of the CPM
539

Efeitos do canabidiol, um canabinóide derivado da Cannabis sativa, em um modelo murino de inflamação pulmonar aguda: uma avaliação imune-neuro-endocrinológica / Effects of cannabidiol, a Cannabis sativa-derived cannabinoid, in a murine model of acute lung injury: an immune-neuro-endocrine evaluation

Ribeiro, Alison 29 February 2012 (has links)
O canabidiol (CBD), o principal canabinóide não psicotrópico extraído da marijuana (Cannabis sativa), é reconhecido por sua potente propriedade imunosupressora e anti-inflamatória. A injúria pulmonar aguda (ALI) é uma doença inflamatória para qual ainda não foi desenvolvida terapias específicas e a única alternativa de tratamento é meramente de suporte em UTI. Desta forma, foi proposta uma investigação sobre os efeitos anti-inflamatórios do CBD em um modelo murino de ALI, induzida pela instilação intra-nasal de LPS (lipopolissacarídeo), dentro de uma perspectiva imune-neuro-endocrinológica. Para a análise do potencial anti-inflamatório do CBD, avaliou-se a contagem total e diferencial de células do lavado broncoalveolar (LBA) (análise da migração de leucócitos para os pulmões), a atividade de mieloperoxidase (MPO) no tecido pulmonar (análise indireta da atividade de neutrófilos), a produção de citocinas e quimicionas no sobrenadante do LBA (análise do perfil inflamatório pulmonar), a concentração de proteínas (albumina) no sobrenadante do LBA (análise indireta da permeabilidade vascular pulmonar) e a expressão de moléculas de adesão (ICAM-1 e VLA-4) em leucócitos do LBA. Analisou-se, ainda, o mecanismo farmacológico dos efeitos anti-inflamatórios do CBD no modelo de ALI, utilizando-se de um antagonista altamente seletivo para o receptor de adenosina A2A (ZM241385). Por fim, avaliou-se os efeitos neuroendócrinos do CBD na vigência da inflamação pulmonar; analisou-se a atividade geral dos animais no campo aberto (análise do comportamento doentio) e os níveis séricos de corticosterona (análise da ativação do eixo Hipotálamo-Hipófise-Adrenal (HPA)). Mostrou-se que tanto o tratamento prolifático (antes da indução da inflamação) como o tratamento terapêutico (depois da indução da inflamação), com uma dose única de CBD (20 ou 80 mg/kg) apresenta um efeito anti-inflamatório prolongado em camundongos submetidos ao modelo de ALI (principalmente 1 e 2 dias após a indução da inflamação). Mostrou-se que o CBD diminuiu a migração de leucócitos para os pulmões (neutrófilos, macrófagos e linfócitos), diminuiu a produção de citocinas (TNF e IL-6) e quimicinas (MCP-1 e MIP-2) no LBA, diminuiu a atividade MPO no tecido pulmonar, diminuiu a concentração de albumina no LBA e diminuiu a expressão de moléculas de adesão (ICAM-1) em neutrófilos do LBA. Mostrou-se, ainda, que o receptor de adenosina A2A está envolvido nos efeitos anti-inflamatórios do CBD na ALI, uma vez que o tratamento com o ZM241385 aboliu todos os efeitos anti-inflamatórios descritos previamente. Por fim, mostrou-se que o CBD apresentou poucos efeitos comportamentais no campo aberto e que não ativou o eixo HPA. Desta forma, mostrou-se pela primeira vez que o tratamento profilático e, também, o tratamento terapêutico com CBD (20 ou 80 mg/kg) tem um efeito anti-inflamatório prolongado em um modelo murino de ALI, muito provavelmente em decorrência de um aumento da sinalização via receptor de adenosina A2A. Por esta razão, acredita-se que o CBD possa ser considerado, no futuro, uma ferramenta terapêutica útil no tratamento de doenças inflamatórias pulmonares. / Cannabidiol (CBD), the major non-psychotropic plant (Cannabis sativa)-derived cannabinoid, is recognized for its immunossupressant and anti-inflammatory properties. Acute lung injury (ALI) is an inflammatory condition for which treatment is mainly supportive (ICU patients), because effective therapies have not been developed. Therefore, it was proposed an investigation in order to address the anti-inflammatory effects of CBD in a murine model of LPS-induced ALI, within an immune-neuro-endocrine perspective. To analyze the potential anti-inflammatory effect of CBD, it was evaluated total and differencial cell count of leukocytes present in the bronchoalveolar lavage (BAL) (migration of leukocytes into the lungs), myeloperoxidase activity in the lung tissue (indirect analysis of neutrophil activity), production of cytokines and chemokines in the BAL (analysis of the pulmonar inflammatory profile), protein (albumin) concentration in the BAL (indirect analysis of pulmonar vascular permeability), and expression of adhesion molecules (ICAM-1 and VLA-4) in leukocytes of the BAL. It was also analyzed the pharmacologic mechanism of the anti-inflammatory effects of CBD in the model of ALI, by using a highly selective antagonist of the adenosine A2A receptor (ZM241385). Finally, it was analyzed the neuro-endocrine effects of CBD in the context of lung inflammation; it was analyzed the general activity of the mice in the open field (analysis of sickness behavior) and the seric levels of corticosterone (activation of HPA (Hypothalamus-Hypophysis-Adrenal) axis). It was shown that both prophylactic (before the induction of inflammation) and therapeutic (after the induction of inflammation) protocols of treatment, with a sigle dose of CBD (20 or 80 mg/kg), has a long-term anti-inflammatory effect in mice submitted to the model of ALI (specially, after 1 and 2 days of the induction of inflammation). It was shown that CBD decreased leukocyte (neutrophil, macrophage, and lymphocytes) migration into the lungs, decreased cytokines (TNF and IL-6) and chemokines (MCP-1 and MIP-2) in the BAL, decreased MPO activity in the lung tissue, decreased albumin concentration in the BAL, and decreased adhesion molecule expression (ICAM-1) in neutrophils of the BAL. It was also shown that adenosine A2A receptor is involved in the anti-inflammatory effects of CBD on LPS-induced ALI, because ZM241385 abrogated all of the anti-inflammatory effects of cannabidiol previously described. Finally, it was shown that CBD has discreet behavioral effects in the open field and was not able to activate the HPA axis. Thus, it was shown for the first time that both prophylactic and also therapeutic treatment with CBD (20 or 80 mg/kg) has a long-term anti-inflammatory effect in a murine model of ALI, most likely associated with an increase in the signaling through the adenosine A2A receptor. Hence, it is possible that in the future CBD may prove useful as a therapeutical tool in the treatment of pulmonar inflammatory conditions.
540

Efeitos do canabidiol, um canabinóide derivado da Cannabis sativa, em um modelo murino de inflamação pulmonar aguda: uma avaliação imune-neuro-endocrinológica / Effects of cannabidiol, a Cannabis sativa-derived cannabinoid, in a murine model of acute lung injury: an immune-neuro-endocrine evaluation

Alison Ribeiro 29 February 2012 (has links)
O canabidiol (CBD), o principal canabinóide não psicotrópico extraído da marijuana (Cannabis sativa), é reconhecido por sua potente propriedade imunosupressora e anti-inflamatória. A injúria pulmonar aguda (ALI) é uma doença inflamatória para qual ainda não foi desenvolvida terapias específicas e a única alternativa de tratamento é meramente de suporte em UTI. Desta forma, foi proposta uma investigação sobre os efeitos anti-inflamatórios do CBD em um modelo murino de ALI, induzida pela instilação intra-nasal de LPS (lipopolissacarídeo), dentro de uma perspectiva imune-neuro-endocrinológica. Para a análise do potencial anti-inflamatório do CBD, avaliou-se a contagem total e diferencial de células do lavado broncoalveolar (LBA) (análise da migração de leucócitos para os pulmões), a atividade de mieloperoxidase (MPO) no tecido pulmonar (análise indireta da atividade de neutrófilos), a produção de citocinas e quimicionas no sobrenadante do LBA (análise do perfil inflamatório pulmonar), a concentração de proteínas (albumina) no sobrenadante do LBA (análise indireta da permeabilidade vascular pulmonar) e a expressão de moléculas de adesão (ICAM-1 e VLA-4) em leucócitos do LBA. Analisou-se, ainda, o mecanismo farmacológico dos efeitos anti-inflamatórios do CBD no modelo de ALI, utilizando-se de um antagonista altamente seletivo para o receptor de adenosina A2A (ZM241385). Por fim, avaliou-se os efeitos neuroendócrinos do CBD na vigência da inflamação pulmonar; analisou-se a atividade geral dos animais no campo aberto (análise do comportamento doentio) e os níveis séricos de corticosterona (análise da ativação do eixo Hipotálamo-Hipófise-Adrenal (HPA)). Mostrou-se que tanto o tratamento prolifático (antes da indução da inflamação) como o tratamento terapêutico (depois da indução da inflamação), com uma dose única de CBD (20 ou 80 mg/kg) apresenta um efeito anti-inflamatório prolongado em camundongos submetidos ao modelo de ALI (principalmente 1 e 2 dias após a indução da inflamação). Mostrou-se que o CBD diminuiu a migração de leucócitos para os pulmões (neutrófilos, macrófagos e linfócitos), diminuiu a produção de citocinas (TNF e IL-6) e quimicinas (MCP-1 e MIP-2) no LBA, diminuiu a atividade MPO no tecido pulmonar, diminuiu a concentração de albumina no LBA e diminuiu a expressão de moléculas de adesão (ICAM-1) em neutrófilos do LBA. Mostrou-se, ainda, que o receptor de adenosina A2A está envolvido nos efeitos anti-inflamatórios do CBD na ALI, uma vez que o tratamento com o ZM241385 aboliu todos os efeitos anti-inflamatórios descritos previamente. Por fim, mostrou-se que o CBD apresentou poucos efeitos comportamentais no campo aberto e que não ativou o eixo HPA. Desta forma, mostrou-se pela primeira vez que o tratamento profilático e, também, o tratamento terapêutico com CBD (20 ou 80 mg/kg) tem um efeito anti-inflamatório prolongado em um modelo murino de ALI, muito provavelmente em decorrência de um aumento da sinalização via receptor de adenosina A2A. Por esta razão, acredita-se que o CBD possa ser considerado, no futuro, uma ferramenta terapêutica útil no tratamento de doenças inflamatórias pulmonares. / Cannabidiol (CBD), the major non-psychotropic plant (Cannabis sativa)-derived cannabinoid, is recognized for its immunossupressant and anti-inflammatory properties. Acute lung injury (ALI) is an inflammatory condition for which treatment is mainly supportive (ICU patients), because effective therapies have not been developed. Therefore, it was proposed an investigation in order to address the anti-inflammatory effects of CBD in a murine model of LPS-induced ALI, within an immune-neuro-endocrine perspective. To analyze the potential anti-inflammatory effect of CBD, it was evaluated total and differencial cell count of leukocytes present in the bronchoalveolar lavage (BAL) (migration of leukocytes into the lungs), myeloperoxidase activity in the lung tissue (indirect analysis of neutrophil activity), production of cytokines and chemokines in the BAL (analysis of the pulmonar inflammatory profile), protein (albumin) concentration in the BAL (indirect analysis of pulmonar vascular permeability), and expression of adhesion molecules (ICAM-1 and VLA-4) in leukocytes of the BAL. It was also analyzed the pharmacologic mechanism of the anti-inflammatory effects of CBD in the model of ALI, by using a highly selective antagonist of the adenosine A2A receptor (ZM241385). Finally, it was analyzed the neuro-endocrine effects of CBD in the context of lung inflammation; it was analyzed the general activity of the mice in the open field (analysis of sickness behavior) and the seric levels of corticosterone (activation of HPA (Hypothalamus-Hypophysis-Adrenal) axis). It was shown that both prophylactic (before the induction of inflammation) and therapeutic (after the induction of inflammation) protocols of treatment, with a sigle dose of CBD (20 or 80 mg/kg), has a long-term anti-inflammatory effect in mice submitted to the model of ALI (specially, after 1 and 2 days of the induction of inflammation). It was shown that CBD decreased leukocyte (neutrophil, macrophage, and lymphocytes) migration into the lungs, decreased cytokines (TNF and IL-6) and chemokines (MCP-1 and MIP-2) in the BAL, decreased MPO activity in the lung tissue, decreased albumin concentration in the BAL, and decreased adhesion molecule expression (ICAM-1) in neutrophils of the BAL. It was also shown that adenosine A2A receptor is involved in the anti-inflammatory effects of CBD on LPS-induced ALI, because ZM241385 abrogated all of the anti-inflammatory effects of cannabidiol previously described. Finally, it was shown that CBD has discreet behavioral effects in the open field and was not able to activate the HPA axis. Thus, it was shown for the first time that both prophylactic and also therapeutic treatment with CBD (20 or 80 mg/kg) has a long-term anti-inflammatory effect in a murine model of ALI, most likely associated with an increase in the signaling through the adenosine A2A receptor. Hence, it is possible that in the future CBD may prove useful as a therapeutical tool in the treatment of pulmonar inflammatory conditions.

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