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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.
181

Spezies- und Tieraltersbestimmung von Geweben des zentralen Nervensystems anhand des Fettsäuremusters

Grießbach, Maria 15 September 2010 (has links) (PDF)
Massiver wirtschaftlicher Schaden und der Verlust des Verbrauchervertrauens hervorgerufen durch die BSE - Krise führten zu einer radikalen Änderung in der Futtermittel- und Lebensmittelgesetzgebung. Neben diversen anderen Maßnahmen wurden u. a. das Gehirn und Rückenmark von über 12 Monate alten Wiederkäuern vom Gesetzgeber als so genanntes spezifiziertes Risikomaterialien (SRM) definiert. Die spezielle Entsorgung und das Verarbeitungsverbot dieser Materialien in Lebens- und Futtermitteln hatte zum Ziel die Infektkette zu unterbrechen und dadurch das Risiko einer Infektion mit dem BSE-Erreger für den Verbraucher zu senken. Um die Einhaltung des Verarbeitungsverbotes von SRM in Lebensmitteln zu überprüfen, wurden diverse ZNS-Nachweisverfahren entwickelt. Jedoch ist keines, der hierfür entwickelten molekularbiologischen und immunochemischen Verfahren in der Lage sowohl Spezies, als auch Tieralter des nachgewiesenen ZNS zu bestimmen und damit eine potentielle Einordnung zum SRM zu ermöglichen. Darüber hinaus hat sich für fast alle ZNS-Marker der Einfluss von hohen Prozesstemperaturen als nachteilig für die Nachweisbarkeit erwiesen. NIEDERER und BOLLHALDER (2001) entwickelten ein auf Fettsäureanalytik basierendes ZNS-Nachweisverfahren, welches am Institut für Lebensmittelhygiene der Universität Leipzig weiterentwickelt wurde. Vorteile dieses Verfahrens sind die hitzestabilen Marker und die Möglichkeit mit Hilfe von spezifischen Fettsäureverhältnissen Spezies und Tieralters des nachgewiesenen ZNS zu ermitteln. Somit ist es mit diesem Verfahren erstmals möglich das nachgewiesene ZNS der Gruppe der spezifizierten Risikomaterialien zuzuordnen. Ziel dieser Arbeit war es, das am Institut für Lebensmittelhygiene weiterentwickelte Verfahren auf Praxistauglichkeit anhand eines externen Blindversuchs zu testen. Hierbei sollten mögliche Schwachstellen identifiziert und im weiterführenden Verlauf dieser Arbeit Lösungen erarbeitet werden. Für den Blindversuch wurden vom Max-Rubner-Institut, Standort Kulmbach, insgesamt 72 Brühwurstproben zur Verfügung gestellt, welche mittels des nach LÜCKER et al. (2005) beschriebenen Verfahrens untersucht wurden. Die Ergebnisse des Blindversuchs deuten auf eine grundsätzliche Eignung des Verfahrens für den Nachweis von spezifiziertem Risikomaterial in Fleischerzeugnissen hin. Jedoch konnte bei der Tierartdifferenzierung und vor allem bei der Altersbestimmung ein Optimierungsbedarf ermittelt werden. Somit ergaben sich für diese Arbeit folgende weiterführende Aufgabenstellungen: 1. Die Optimierung der Tierartbestimmung auch im Hinblick auf Erweiterung des Speziesspektrums und 2. die Optimierung der Tieraltersbestimmung von Rinder- und Schaf-ZNS. Insgesamt 257 ZNS-Proben der Spezies Rind, Schaf, Schwein, Ziege und Geflügel wurden einer Fettsäureanalyse unterzogen. Aus allen analysierten Fettsäuren wurden 67 Fettsäureverhältnisse gebildet. Zur Identifikation für die Speziesdifferenzierung geeigneter Fettsäureverhältnisse wurde das statistische Verfahren der Partial Least Square – Discriminant Analysis (PLS-DA) eingesetzt. Hierbei ergab sich, dass von den 67 untersuchten Fettsäureverhältnissen insgesamt 14 für die Differenzierung zwischen den Tierarten Rind, Schwein, Schaf, Ziege und Geflügel geeignet sind. Für die Optimierung der Tieraltersbestimmung wurden 37 ZNS-Proben vom Rind und elf ZNS-Proben vom Schaf untersucht. Die analysierten Fettsäuren wurden auf ihre Korrelation mit dem Alter untersucht. Stark korrelierende Fettsäuren und deren Verhältnisse wurden mit Hilfe der Regressionsanalyse auf ihre Vorhersagefähigkeit geprüft. Hierbei gelang die Identifikation von vier neuen Fettsäureverhältnissen. Für die Altersschätzung bei der Tierart Rind scheinen sich die FS-Verhältnisse 2OH-C24:0/2OH-C25:0 und 2OH-C24:1(n-7)/2OH-C25:0 am besten zu eignen. Für die Tierart Schaf sollten die Verhältnisse 2OH-C25:0/2OH-C26:0 und 2OH-C25:0/2OH-C26:1(n-7) bevorzugt eingesetzt werden. Im Vergleich zur bisherigen Verfahrensweise ist mit Hilfe dieser Fettsäureverhältnisse und deren Regressionsformeln eine deutlich präzisere Altersschätzung für die Tierarten Rind und Schaf möglich. Der neue Ansatz bietet die Möglichkeit flexibel auf zukünftige Änderungen der Altersgrenze von SRM zu reagieren. / The immense economical damage and the loss of consumer trust caused by the bovine spongiform encephalopathy (BSE) - crisis resulted in a radical alteration of the feed- and foodlegislation. Besides several other measures, the legislator defined the brain and spinal cord of ruminants older than 12 month as specified risk material (SRM). The special disposal and the processing prohibition of these materials in food and feedstuffs aimed to interrupt the infection chain and to reduce the risk of an infection caused by the BSE pathogen for the consumer. In order to control the processing prohibition of SRM in food, several CNS detection methods were developed. But none of the designed molecular biological or immuno chemical methods has the ability to detect species and age of the CNS. Therefore, a classification of the detected CNS as SRM is not possible. Furthermore, high process temperatures influence nega-tively the detection of almost all CNS markers. NIEDERER and BOLLHALDER (2001) developed a CNS detection procedure based on the analysis of fatty acids, which was improved at the Institute of Food Hygiene, University Leipzig. Advantages of this procedure are the heat stability of the markers and the possibility to identify species and age of the detected CNS. Therefore, this procedure is the first, which facilitates the potential of identifying SRM. The aim of this work was to test the practicability of the improved CNS detection procedure in an external blind trial. During this, possible weak points should be identified and solutions for their elimination presented. Furthermore, the sample preparation of the method should be optimized with regard to cost and time reduction. For the external blind trial the Max-Rubner-Institute, Kulmbach, produced 72 emulsion type sausages. These sausages were analysed according to the procedure described by LÜCKER et al. 2005. The results of the blind trial show the suitability of the procedure for the detection of SRM in meat products in principle. However, some results revealed that the species and age identification required further enhancement. Therefore, the following additional topics of this work were: 1. Optimization of species identification especially with regard to other species 2. Optimization of animal age prediction for cattle and sheep CNS. Selected fatty acids of total 257 CNS samples from cattle, pig, sheep, goat and several poultry species were analysed. These fatty acids were combined to 67 fatty acid ratios. Afterwards, the application of these ratios for the species detection was tested by using the statistical method of Partial Least Square – Discriminant Analysis (PLS-DA). In result, 14 out of 67 fatty acid ratios are suitable for differentiation between the species cattle, pig, sheep, goat and poultry. For the optimization of animal age prediction 37 CNS samples from cattle and eleven CNS samples from sheep were examined. All analyzed fatty acids were checked for their correlation with age. Afterwards strong correlating fatty acids and their fatty acid ratios were examined for their predictive ability by the application of regression analysis. In result, four new fatty acid ratios for age prediction could be identified. For the age prediction of cattle CNS the fatty acid ratios 2OH-C24:0/2OH-C25:0 and 2OH-C24:1(n-7)/2OH-C25:0 are the best choice. In sheep CNS the ratios 2OH-C25:0/2OH-C26:0 and 2OH-C25:0/2OH-C26:1(n-7) should be preferred for prediction of age. In comparison to the previous age prediction method, the application of these fatty acid ratios and their regression formula led to more accurate results. Furthermore, it offers the possibility to adopt to possible variations of the age limits within the SRM definition in future.
182

Untersuchungen zu Bedeutung von TGF-β während der Entwicklung des Vorderhirns / Investigation of the role of transforming growth factor β during forebrain development

Ahrens, Sandra 20 January 2009 (has links)
No description available.
183

Administration d'Eugénol intrathécal pour le traitement de la douleur neuropathique

Lionnet, Ludivine 08 1900 (has links)
Le projet porte sur l’étude de l’effet de l’eugénol, composant principal du clou de girofle, sur la douleur neuropathique. L’objectif principal du projet était de déterminer la contribution du système nerveux central dans l’effet analgésique de l’eugénol. Lors d’une étude préliminaire, la pénétrabilité de l’eugénol a été évaluée dans le système nerveux central du rat. Des échantillons de sang, de cerveau et de moelle épinière ont été prélevés et les concentrations d’eugénol dans ces différents tissus ont été analysées à l’aide d’un spectromètre de masse. Les résultats ont montré que l’eugénol pénètre bien le système nerveux central avec une distribution plus importante dans la moelle épinière. Après l’induction de la douleur neuropathique à des rats Sprague-Dawley par le modèle de ligatures du nerf sciatique, des injections intrathécales d’eugénol furent réalisées afin d’évaluer l’effet central de l’eugénol. La plus forte dose d’eugénol a atténué l’allodynie secondaire après 15min, 2h et 4h et a aussi amélioré l’hyperalgésie thermique après 2h et 4h. Ces résultats confirment l’hypothèse que l’eugénol atténue les deux aspects de la douleur neuropathique que sont l’allodynie et l’hyperalgésie. Les injections au niveau lombaire permettent de penser que l’eugénol, un agoniste/antagoniste des récepteurs vanilloïdes pourrait diminuer la douleur neuropathique en agissant notamment au niveau des récepteurs vanilloïdes situés dans la corne dorsale de la moelle épinière. / The project is based on the study of the effects of eugenol, the main component of clove oil, on neuropathic pain. The main objective was to determine the central effect of eugenol. In a preliminary study we evaluated the penetrability of eugenol in the central nervous system of rats. Blood, brain and spinal cord samples were collected and concentrations were determined by mass spectrometry. Brain-toplasma and spinal cord-to-plasma ratios suggest that eugenol penetrates the central nervous system of rats relatively well, with a preferential distribution in the spinal cord. Following the induction of neuropathic pain in male Sprague-Dawley rats using the sciatic nerve ligation model, intrathecal injections of eugenol were done to evaluate the central effect of eugenol. Treatment with the high dose of eugenol significantly decreased secondary mechanical allodynia measured by the Von Frey test after 15min, 2h and 4h and improved thermal hyperalgesia measured by the Hargreaves device after 2h and 4h. Results support the hypothesis that eugenol may alleviate neuropathic pain, both allodynia and hyperalgesia. Eugenol, a vanilloid agonist/antagonist may therefore reduce neuropathic pain by acting on vanilloid receptors at the level of the dorsal horn of the spinal cord.
184

Neurotoxicity of β-lactam antibiotics : experimental kinetic and neurophysiological studies

Schliamser, Silvia E. January 1988 (has links)
The neurotoxic potential of intravenous administered benzylpenicillin (BPC) was studied in rabbits with intact blood-CNS barriers and rabbits with experimental E. coli meningitis. At onset of epileptogenic EEG activity or seizures, serum, CSF and brain tissue were collected for assay of BPC. Based on the fact that, in tissues, BPC seems to remain extracellularly, brain concentrations of BPC were expressed as brain tissue fluid (BTF) levels, calculated as lOx the concentration in whole brain tissue. Neurotoxicity could be precipitated in all rabbits. In normal rabbits BTF levels of BPC were considerably higher than those in CSF indicating a better penetration across the blood-brain barrier (BBB). BPC penetrated better to CSF and BTF in meningitic rabbits than in normal controls, suggesting some degree of damage of the BBB concomitant with meningeal inflammation. E. coli meningitis did not increase the neurotoxicity of BPC. In control rabbits the intracistemal injection of saline resulted in some degree of pleocytosis. Unmanipulated animals are therefore preferable as controls. Epileptogenic EEG-changes was the most precise of the two variables used for demonstration of neurotoxicity. EEG-changes were therefore used as neurotoxicity criterion in the following rabbit experiments. To evaluate the effect of uraemia alone and uraemia plus meningitis on the neurotoxity of BPC in rabbits, cephaloridine was used to induce uraemia. Meningitis was induced by intracistemal inoculation of a cephalosporinresistant strain of E. cloacae. Untreated  rabbits were used as controls. Uraemia resulted in increased BTF penetration of BPC, possibly explained by permeability changes in the BBB and/or decreased binding of BPC to albumin. Uraemia did not result in increased penetration of BPC into the CSF of non-meningitic rabbits. Uraemic non-meningitic rabbits had the highest BTF levels of BPC at the criterion, indicating that cephaloridine-induced renal failure increased the epileptogenic threshold in these rabbits. The combination of uraemia and meningitis increased the neurotoxicity of BPC since the criterion was reached at considerably lower BTF levels of BPC. Meningitis, either alone or together with uraemia, did not increase the neurotoxicity in comparison to control rabbits. Higher BTF levels of BPC were found in meningitic rabbits than in controls with intact blood-CNS barriers at onset of EEG-changes. In all groups of rabbits there was a pronounced variability of BPC levels in the CSF while the intra-group variations in BTF levels were much smaller. Thus, BTF and not CSF levels were decisive for the neurotoxicity of BPC. Using   the same EEG-model, the neurotoxic potential of imipenem/cilastatin (I) and a new penem derivative, FCE 22101 were compared in a cross-over study. Both I and FCE 22101 were significantly more neurotoxic than BPC. While BTF levels of the three antibiotics could be detected in all tested rabbits, detectable CSF levels were only found in one of twelve rabbits treated with I or FCE 22101, indicating that BTF concentrations rather than CSF ones are decisive for neurotoxicity of ß-lactam antibiotics. The EEG-model used was found to be a suitable model for cross-over studies of intravenously administered antibiotics. Using the "silent-second" as EEG-threshold, a CNS interaction between intraperitoneally administered BPC and intravenous thiopental was demonstrated in rats. The most probably site for this interaction is the organic acid transport system out of the CNS. Thiopental distribution in the rat brain seemed to depend not only on its lipid solubility. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1988, härtill 5 uppsatser.</p> / digitalisering@umu
185

Integration of Sensory Feedback When Adapting to Novel Visuomotor Environments

Hinder, Mark Unknown Date (has links)
The aim of the research described in this thesis is to improve our understanding of how the central nervous system (CNS) integrates feedback information from different sensory modalities to permit skill acquisition, and the subsequent consolidation of that skill, when exposed to a novel visuomotor environment. Indeed, such adaptation must be consolidated and recalled when appropriate such that we do not have to continually relearn skills we once possessed. By manipulating the sensory feedback available from the visual and proprioceptive systems during learning, it is possible to determine those facets of the sensory feedback that are essential for adaptation to occur. The thesis consists of seven chapters. The first and last provide a conceptual basis for, and an overall discussion of, the research. Chapter 2 reviews current visuomotor adaptation research, with particular focus on the manner in which information about novel tasks is stored within the CNS as we adapt, and the sensory information that is necessary to allow this adaptation to occur. Furthermore, this chapter serves to introduce many of the experimental techniques that are used to investigate motor learning in humans. Chapter 3 is a report of an investigation of the issues of interference and consolidation in an isometric target acquisition task. Exposure to a 30° counter-clockwise (CCW) rotation was followed by a period of rest, trials with no rotation, or trials with a 60° clockwise (CW) rotation. Retention of the initial adaptation was assessed 5 hours later. Full interference was manifested in circumstances in which either counter-rotated or non-rotated trials were encountered following the initial learning period. These results are consistent with the view that the observed interference is anterograde in nature, and highlight differences in the mechanisms employed by the CNS when compensating for novel kinematics (e.g. visuomotor rotations) compared with adapting to novel dynamics (e.g. external forces). Chapter 4 is a report of an investigation of the role of visual feedback in adapting to novel visuomotor environments in an isometric target acquisition task. Following trials with no rotation, participants adapted to a 60° CCW visuomotor rotation before returning to the non-rotated condition. Separate groups received either continuous visual feedback (CF) of cursor position during task execution or post-trial visual feedback (PF), both indicating task performance. One CF group were instructed to make any (feedback) modifications necessary during the task to reduce errors and acquire the target, while another CF group were instructed to make uncorrected, ballistic movements. Colour cues permitted the identification of the task environment (nonrotated/ rotated) on every trial. The results indicate that an automatic recalibration of the visuomotor mapping occurs when CF is provided, and suggest that performance improvements with PF may occur via the adoption of a cognitively mediated strategy. Furthermore, execution of feedback motor commands to correct errors did not enhance the adaptation that occurred when CF was provided, indicating that the perception of sensory errors (and not feedback commands that may be applied to reduce those errors) drives feedforward visuomotor adaptation. To investigate whether additional proprioceptive feedback associated with movement altered the adaptation patterns observed in chapter 4, a study similar to that reported in chapter 4 was undertaken, and is reported in chapter 5. In this instance a discrete, goaldirected, movement task replaced the isometric task. Subjects were deprived of vision of their arm, but were provided with PF or CF indicating task performance. The patterns of adaptation noted in the isometric task were also exhibited in this dynamic task, indicating that the timing of the visual feedback of task performance has a profound effect on how performance improvements in a novel visuomotor rotation occur. The experiment reported in Chapter 6 assessed the ability to adapt to two conflicting visuomotor rotations interleaved within the same training period, when each task variant (rotation) could be identified by contextual (colour) cues. While full dual adaptation was not observed, the results suggest that the colour cues may have been utilised to explicitly select distinct motor commands for each task rotation.
186

Integration of Sensory Feedback When Adapting to Novel Visuomotor Environments

Hinder, Mark Unknown Date (has links)
The aim of the research described in this thesis is to improve our understanding of how the central nervous system (CNS) integrates feedback information from different sensory modalities to permit skill acquisition, and the subsequent consolidation of that skill, when exposed to a novel visuomotor environment. Indeed, such adaptation must be consolidated and recalled when appropriate such that we do not have to continually relearn skills we once possessed. By manipulating the sensory feedback available from the visual and proprioceptive systems during learning, it is possible to determine those facets of the sensory feedback that are essential for adaptation to occur. The thesis consists of seven chapters. The first and last provide a conceptual basis for, and an overall discussion of, the research. Chapter 2 reviews current visuomotor adaptation research, with particular focus on the manner in which information about novel tasks is stored within the CNS as we adapt, and the sensory information that is necessary to allow this adaptation to occur. Furthermore, this chapter serves to introduce many of the experimental techniques that are used to investigate motor learning in humans. Chapter 3 is a report of an investigation of the issues of interference and consolidation in an isometric target acquisition task. Exposure to a 30° counter-clockwise (CCW) rotation was followed by a period of rest, trials with no rotation, or trials with a 60° clockwise (CW) rotation. Retention of the initial adaptation was assessed 5 hours later. Full interference was manifested in circumstances in which either counter-rotated or non-rotated trials were encountered following the initial learning period. These results are consistent with the view that the observed interference is anterograde in nature, and highlight differences in the mechanisms employed by the CNS when compensating for novel kinematics (e.g. visuomotor rotations) compared with adapting to novel dynamics (e.g. external forces). Chapter 4 is a report of an investigation of the role of visual feedback in adapting to novel visuomotor environments in an isometric target acquisition task. Following trials with no rotation, participants adapted to a 60° CCW visuomotor rotation before returning to the non-rotated condition. Separate groups received either continuous visual feedback (CF) of cursor position during task execution or post-trial visual feedback (PF), both indicating task performance. One CF group were instructed to make any (feedback) modifications necessary during the task to reduce errors and acquire the target, while another CF group were instructed to make uncorrected, ballistic movements. Colour cues permitted the identification of the task environment (nonrotated/ rotated) on every trial. The results indicate that an automatic recalibration of the visuomotor mapping occurs when CF is provided, and suggest that performance improvements with PF may occur via the adoption of a cognitively mediated strategy. Furthermore, execution of feedback motor commands to correct errors did not enhance the adaptation that occurred when CF was provided, indicating that the perception of sensory errors (and not feedback commands that may be applied to reduce those errors) drives feedforward visuomotor adaptation. To investigate whether additional proprioceptive feedback associated with movement altered the adaptation patterns observed in chapter 4, a study similar to that reported in chapter 4 was undertaken, and is reported in chapter 5. In this instance a discrete, goaldirected, movement task replaced the isometric task. Subjects were deprived of vision of their arm, but were provided with PF or CF indicating task performance. The patterns of adaptation noted in the isometric task were also exhibited in this dynamic task, indicating that the timing of the visual feedback of task performance has a profound effect on how performance improvements in a novel visuomotor rotation occur. The experiment reported in Chapter 6 assessed the ability to adapt to two conflicting visuomotor rotations interleaved within the same training period, when each task variant (rotation) could be identified by contextual (colour) cues. While full dual adaptation was not observed, the results suggest that the colour cues may have been utilised to explicitly select distinct motor commands for each task rotation.
187

Análise química e avaliação das atividades biológicas e comportamentais de extratos de frutas ricas em compostos fenólicos (mirtilo e amora-preta) / Chemical analysis and evaluation of the biological and behavioral activities of extracts of fruits rich in phenolic compounds (Blueberry and blackberry)

Ramirez, Maria Rosana January 2008 (has links)
O presente estudo teve como objetivos: determinar o teor dos polifenóis: flavonóides e antocianos totais presentes nos extratos de mirtilo (Vaccinium ashei) e amora preta (Rubus sp) por espectrofotometria; desenvolver e validar uma metodologia analítica para a caracterização dos extratos por cromatografia líquida de alta eficiência (CLAE), identificar, isolar e quantificar os principais compostos; avaliar a atividade anticolinesterásica, antioxidante frente à difenilpicrilhidrazol (DPPH) e anti-quimiotática in vitro; realizar a dosagem de aminas biogênicas no cérebro, investigar as possíveis atividades antinociceptiva, antiinflamatória, antiepiléptica, cognitiva e neuroprotetora do extrato de Vaccinium ashei, e o efeito neuroprotetor de um composto isolado a partir de Rubus: a cianidina, em vários modelos experimentais in vivo, em ratos e camundongos. Os perfis cromatográficos apresentaram compostos comuns às duas amostras; onde foram identificados 4 flavonóides, sendo hiperosídeo, quercitrina e isoquercitrina comuns a ambos extratos, e a rutina confirmada apenas em Rubus. Cinco antocianidinas foram identificadas em Vaccinium: delfinidina, cianidina, petunidina, peonidina e malvidina, e a cianidina em Rubus. Os resultados demonstraram, diferenças nas quantidades totais de polifenóis, flavonóides e antocianos. Todos os extratos, apresentaram atividade seqüestradora do radical DPPH in vitro. A atividade antiquimiotática in vitro foi comprovada para a fração flavonoídica. Os ensaios biológicos realizados in vivo demonstraram que o extrato preparado a partir de uma mistura de diferentes cultivares de Vaccinium ashei apresentou efeitos antinociceptivos nos testes da formalina sub-plantar, contorções abdominais, placa quente e tail flick. Produziu também efeito neuroprotetor, avaliado pelo ensaio cometa e pelo método de TOSC. Também causou aumento da atividade locomotora, assim como exerceu um efeito ansiolítico em roedores adultos. Facilitou a memória de curta duração e a Memória de longa duração e produziu um aumento de 5-HT no estriado e hipocampo de ratos adultos. Foi observado também que a cianidina isolada exerceu atividade neuroprotetora conforme avaliado pelo método de TOSC em ratos adultos. Não foram observadas diferenças significativas no modelo de epilepsia, entre o grupo tratado e o grupo controle, assim como não foram detectadas alterações no sistema dopaminérgico. Em síntese, os dados analisados em conjunto, permitem sugerir que o extrato de Vaccinium ashei e compostos isolados a partir de Rubus sp., como a cianidina, apresentam importante efeito neuroprotetivo, antinociceptivo e cognitivo, e nesta ação está envolvida a participação direta ou indireta dos receptores serotonérgico, acetilcolinérgicos, opióides e de citocinas pró-inflamatórias. Neste sentido, foram obtidos avanços significativos acerca dos mecanismos de ação de ambos gêneros o que torna o seu extrato e seus princípios ativos interessantes para o aproveitamento e desenvolvimento de novos alimentos funcionais e/ou nutracêuticos. / The objectives of this study were: comparing total phenolics, total anthocyanins and antioxidant capacity in appropriate berry samples from selected cultivars of the Vaccinium ashei and Rubus. A reliable HPLC procedure for determining the profile, quantifying and isolating of major compounds present in the extracts have been developed. The potential effects of the extracts were observed by chemotaxis assay, by acetilcholinesterasic inhibition, and their antioxidant properties evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) in vitro. Otherwise, we examined the antinociceptive, antiinflammatory, cognitive, anti-epileptic and neuroprotective effects of the extract of Vaccinium ashei in several experimental models in vivo, as well as biogenic amine concentration, in specific brain regions in rats and mice. In addition, it was tested the efficacy of oral administration of cyanidin-3-glucoside extracted from Rubus sp. in lipid peroxidation in brain rats (TOSC). An HPLC method for the analysis of anthocyanidins and flavonoids in berries extracts have been developed. The data obtained show that various compounds are common in the fruits analyzed, and four flavonoids were identified: hyperoside, quercetrin and isoquercitrin occurring in both fruits, and rutin occurring only in Rubus. Five anthocyanidins were identified in Vaccinium: delphinidin, cyanidin, peonidin, petunidin, and malvidin, and in Rubus cyanidin 3-glucoside was the major anthocyanin. We found that the flavonoids fractions significantly have inhibited migration celullar and acetilcholynestarase, and both total extract and fractions exhibited strong antioxidant activity. The extract (a mixture from the different cultivars) significantly enhanced short and long-term memory in the inhibitory avoidance task, induced an increase in the number of crossings during open field habituation, and had an anxiolytic effect in the elevated plus-maze task. These processes are accompanied by alterations in serotonin (5-HT) in the striatum, and the hippocampus. Cyanidin 3-glucoside isolated significantly reduced lipid peroxidation in hippocampal tissue in rats. In conclusion, the data from the current study show that the Vaccinum extract produce an important neuroprotective, cognitive and antinociceptive effect, which could be related with a direct or indirect interaction with the serotonergic, cholinergic, opioids receptors and pro-inflammatory cytokines. On the other hand, the extract don’t have protected the pentilenotetrazole-induced convulsions in mice, or influenced the memory retention in old rats when accessed in the step-down inhibitory avoidance, and showed no anxiolytic action in an elevated plus maze. The Vaccinium ashei extract did not alter locomotor activity, and the dopamine concentration in adult or old rats.
188

Análise química e avaliação das atividades biológicas e comportamentais de extratos de frutas ricas em compostos fenólicos (mirtilo e amora-preta) / Chemical analysis and evaluation of the biological and behavioral activities of extracts of fruits rich in phenolic compounds (Blueberry and blackberry)

Ramirez, Maria Rosana January 2008 (has links)
O presente estudo teve como objetivos: determinar o teor dos polifenóis: flavonóides e antocianos totais presentes nos extratos de mirtilo (Vaccinium ashei) e amora preta (Rubus sp) por espectrofotometria; desenvolver e validar uma metodologia analítica para a caracterização dos extratos por cromatografia líquida de alta eficiência (CLAE), identificar, isolar e quantificar os principais compostos; avaliar a atividade anticolinesterásica, antioxidante frente à difenilpicrilhidrazol (DPPH) e anti-quimiotática in vitro; realizar a dosagem de aminas biogênicas no cérebro, investigar as possíveis atividades antinociceptiva, antiinflamatória, antiepiléptica, cognitiva e neuroprotetora do extrato de Vaccinium ashei, e o efeito neuroprotetor de um composto isolado a partir de Rubus: a cianidina, em vários modelos experimentais in vivo, em ratos e camundongos. Os perfis cromatográficos apresentaram compostos comuns às duas amostras; onde foram identificados 4 flavonóides, sendo hiperosídeo, quercitrina e isoquercitrina comuns a ambos extratos, e a rutina confirmada apenas em Rubus. Cinco antocianidinas foram identificadas em Vaccinium: delfinidina, cianidina, petunidina, peonidina e malvidina, e a cianidina em Rubus. Os resultados demonstraram, diferenças nas quantidades totais de polifenóis, flavonóides e antocianos. Todos os extratos, apresentaram atividade seqüestradora do radical DPPH in vitro. A atividade antiquimiotática in vitro foi comprovada para a fração flavonoídica. Os ensaios biológicos realizados in vivo demonstraram que o extrato preparado a partir de uma mistura de diferentes cultivares de Vaccinium ashei apresentou efeitos antinociceptivos nos testes da formalina sub-plantar, contorções abdominais, placa quente e tail flick. Produziu também efeito neuroprotetor, avaliado pelo ensaio cometa e pelo método de TOSC. Também causou aumento da atividade locomotora, assim como exerceu um efeito ansiolítico em roedores adultos. Facilitou a memória de curta duração e a Memória de longa duração e produziu um aumento de 5-HT no estriado e hipocampo de ratos adultos. Foi observado também que a cianidina isolada exerceu atividade neuroprotetora conforme avaliado pelo método de TOSC em ratos adultos. Não foram observadas diferenças significativas no modelo de epilepsia, entre o grupo tratado e o grupo controle, assim como não foram detectadas alterações no sistema dopaminérgico. Em síntese, os dados analisados em conjunto, permitem sugerir que o extrato de Vaccinium ashei e compostos isolados a partir de Rubus sp., como a cianidina, apresentam importante efeito neuroprotetivo, antinociceptivo e cognitivo, e nesta ação está envolvida a participação direta ou indireta dos receptores serotonérgico, acetilcolinérgicos, opióides e de citocinas pró-inflamatórias. Neste sentido, foram obtidos avanços significativos acerca dos mecanismos de ação de ambos gêneros o que torna o seu extrato e seus princípios ativos interessantes para o aproveitamento e desenvolvimento de novos alimentos funcionais e/ou nutracêuticos. / The objectives of this study were: comparing total phenolics, total anthocyanins and antioxidant capacity in appropriate berry samples from selected cultivars of the Vaccinium ashei and Rubus. A reliable HPLC procedure for determining the profile, quantifying and isolating of major compounds present in the extracts have been developed. The potential effects of the extracts were observed by chemotaxis assay, by acetilcholinesterasic inhibition, and their antioxidant properties evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) in vitro. Otherwise, we examined the antinociceptive, antiinflammatory, cognitive, anti-epileptic and neuroprotective effects of the extract of Vaccinium ashei in several experimental models in vivo, as well as biogenic amine concentration, in specific brain regions in rats and mice. In addition, it was tested the efficacy of oral administration of cyanidin-3-glucoside extracted from Rubus sp. in lipid peroxidation in brain rats (TOSC). An HPLC method for the analysis of anthocyanidins and flavonoids in berries extracts have been developed. The data obtained show that various compounds are common in the fruits analyzed, and four flavonoids were identified: hyperoside, quercetrin and isoquercitrin occurring in both fruits, and rutin occurring only in Rubus. Five anthocyanidins were identified in Vaccinium: delphinidin, cyanidin, peonidin, petunidin, and malvidin, and in Rubus cyanidin 3-glucoside was the major anthocyanin. We found that the flavonoids fractions significantly have inhibited migration celullar and acetilcholynestarase, and both total extract and fractions exhibited strong antioxidant activity. The extract (a mixture from the different cultivars) significantly enhanced short and long-term memory in the inhibitory avoidance task, induced an increase in the number of crossings during open field habituation, and had an anxiolytic effect in the elevated plus-maze task. These processes are accompanied by alterations in serotonin (5-HT) in the striatum, and the hippocampus. Cyanidin 3-glucoside isolated significantly reduced lipid peroxidation in hippocampal tissue in rats. In conclusion, the data from the current study show that the Vaccinum extract produce an important neuroprotective, cognitive and antinociceptive effect, which could be related with a direct or indirect interaction with the serotonergic, cholinergic, opioids receptors and pro-inflammatory cytokines. On the other hand, the extract don’t have protected the pentilenotetrazole-induced convulsions in mice, or influenced the memory retention in old rats when accessed in the step-down inhibitory avoidance, and showed no anxiolytic action in an elevated plus maze. The Vaccinium ashei extract did not alter locomotor activity, and the dopamine concentration in adult or old rats.
189

Análise química e avaliação das atividades biológicas e comportamentais de extratos de frutas ricas em compostos fenólicos (mirtilo e amora-preta) / Chemical analysis and evaluation of the biological and behavioral activities of extracts of fruits rich in phenolic compounds (Blueberry and blackberry)

Ramirez, Maria Rosana January 2008 (has links)
O presente estudo teve como objetivos: determinar o teor dos polifenóis: flavonóides e antocianos totais presentes nos extratos de mirtilo (Vaccinium ashei) e amora preta (Rubus sp) por espectrofotometria; desenvolver e validar uma metodologia analítica para a caracterização dos extratos por cromatografia líquida de alta eficiência (CLAE), identificar, isolar e quantificar os principais compostos; avaliar a atividade anticolinesterásica, antioxidante frente à difenilpicrilhidrazol (DPPH) e anti-quimiotática in vitro; realizar a dosagem de aminas biogênicas no cérebro, investigar as possíveis atividades antinociceptiva, antiinflamatória, antiepiléptica, cognitiva e neuroprotetora do extrato de Vaccinium ashei, e o efeito neuroprotetor de um composto isolado a partir de Rubus: a cianidina, em vários modelos experimentais in vivo, em ratos e camundongos. Os perfis cromatográficos apresentaram compostos comuns às duas amostras; onde foram identificados 4 flavonóides, sendo hiperosídeo, quercitrina e isoquercitrina comuns a ambos extratos, e a rutina confirmada apenas em Rubus. Cinco antocianidinas foram identificadas em Vaccinium: delfinidina, cianidina, petunidina, peonidina e malvidina, e a cianidina em Rubus. Os resultados demonstraram, diferenças nas quantidades totais de polifenóis, flavonóides e antocianos. Todos os extratos, apresentaram atividade seqüestradora do radical DPPH in vitro. A atividade antiquimiotática in vitro foi comprovada para a fração flavonoídica. Os ensaios biológicos realizados in vivo demonstraram que o extrato preparado a partir de uma mistura de diferentes cultivares de Vaccinium ashei apresentou efeitos antinociceptivos nos testes da formalina sub-plantar, contorções abdominais, placa quente e tail flick. Produziu também efeito neuroprotetor, avaliado pelo ensaio cometa e pelo método de TOSC. Também causou aumento da atividade locomotora, assim como exerceu um efeito ansiolítico em roedores adultos. Facilitou a memória de curta duração e a Memória de longa duração e produziu um aumento de 5-HT no estriado e hipocampo de ratos adultos. Foi observado também que a cianidina isolada exerceu atividade neuroprotetora conforme avaliado pelo método de TOSC em ratos adultos. Não foram observadas diferenças significativas no modelo de epilepsia, entre o grupo tratado e o grupo controle, assim como não foram detectadas alterações no sistema dopaminérgico. Em síntese, os dados analisados em conjunto, permitem sugerir que o extrato de Vaccinium ashei e compostos isolados a partir de Rubus sp., como a cianidina, apresentam importante efeito neuroprotetivo, antinociceptivo e cognitivo, e nesta ação está envolvida a participação direta ou indireta dos receptores serotonérgico, acetilcolinérgicos, opióides e de citocinas pró-inflamatórias. Neste sentido, foram obtidos avanços significativos acerca dos mecanismos de ação de ambos gêneros o que torna o seu extrato e seus princípios ativos interessantes para o aproveitamento e desenvolvimento de novos alimentos funcionais e/ou nutracêuticos. / The objectives of this study were: comparing total phenolics, total anthocyanins and antioxidant capacity in appropriate berry samples from selected cultivars of the Vaccinium ashei and Rubus. A reliable HPLC procedure for determining the profile, quantifying and isolating of major compounds present in the extracts have been developed. The potential effects of the extracts were observed by chemotaxis assay, by acetilcholinesterasic inhibition, and their antioxidant properties evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) in vitro. Otherwise, we examined the antinociceptive, antiinflammatory, cognitive, anti-epileptic and neuroprotective effects of the extract of Vaccinium ashei in several experimental models in vivo, as well as biogenic amine concentration, in specific brain regions in rats and mice. In addition, it was tested the efficacy of oral administration of cyanidin-3-glucoside extracted from Rubus sp. in lipid peroxidation in brain rats (TOSC). An HPLC method for the analysis of anthocyanidins and flavonoids in berries extracts have been developed. The data obtained show that various compounds are common in the fruits analyzed, and four flavonoids were identified: hyperoside, quercetrin and isoquercitrin occurring in both fruits, and rutin occurring only in Rubus. Five anthocyanidins were identified in Vaccinium: delphinidin, cyanidin, peonidin, petunidin, and malvidin, and in Rubus cyanidin 3-glucoside was the major anthocyanin. We found that the flavonoids fractions significantly have inhibited migration celullar and acetilcholynestarase, and both total extract and fractions exhibited strong antioxidant activity. The extract (a mixture from the different cultivars) significantly enhanced short and long-term memory in the inhibitory avoidance task, induced an increase in the number of crossings during open field habituation, and had an anxiolytic effect in the elevated plus-maze task. These processes are accompanied by alterations in serotonin (5-HT) in the striatum, and the hippocampus. Cyanidin 3-glucoside isolated significantly reduced lipid peroxidation in hippocampal tissue in rats. In conclusion, the data from the current study show that the Vaccinum extract produce an important neuroprotective, cognitive and antinociceptive effect, which could be related with a direct or indirect interaction with the serotonergic, cholinergic, opioids receptors and pro-inflammatory cytokines. On the other hand, the extract don’t have protected the pentilenotetrazole-induced convulsions in mice, or influenced the memory retention in old rats when accessed in the step-down inhibitory avoidance, and showed no anxiolytic action in an elevated plus maze. The Vaccinium ashei extract did not alter locomotor activity, and the dopamine concentration in adult or old rats.
190

EFEITO ANTIOXIDANTE DE LIPOSSOMAS CONTENDO CREATINA NO PROCESSO DE ISQUEMIA/REPERFUSÃO CEREBRAL EM RATOS: DESENVOLVIMENTO, CARACTERIZAÇÃO E AVALIAÇÃO FARMACOLÓGICA

Borin, Diego Becker 26 March 2013 (has links)
Made available in DSpace on 2018-06-27T18:56:03Z (GMT). No. of bitstreams: 3 Diego Becker Borin.pdf: 1553948 bytes, checksum: b94d052c85f74f3bcc5e4cadbcb71e67 (MD5) Diego Becker Borin.pdf.txt: 134530 bytes, checksum: f3ad94a2052d1806ff21e9c0ce7733fb (MD5) Diego Becker Borin.pdf.jpg: 3538 bytes, checksum: b4b8b2603cafaeb4736f56efe30f7f1d (MD5) Previous issue date: 2013-03-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Creatine is a biomolecule endogenously synthesized from amino acids which can also be obtained through the diet. But it does not permeate easily through the blood-brain barrier (BBB), so the brain must supply their needs through the synthesis of creatine in the central nervous system (CNS) by itself. Creatine has a major role in maintaining stable levels of adenosine triphosphate (ATP) thus keeping the whole body in a proper condition. Neurodegenerative diseases leads to decreases in ATP levels, which compromises cellular metabolism, generating the increase of reactive species that could lead to neuronal cell death. Therefore, it becomes important to increase creatine levels in neurodegenerative diseases, so it could provide new alternative treatments for these diseases. This study aimed to develop and characterize liposomes with creatine, as well as investigate its protective effect in ischemia and reperfusion (I/R) brain model. Two methodologies were used for the preparation of liposomes, the lipid film hydration and ethanol injection. Due the best results were obtained by the ethanol injection method, this was chosen for the preparation of liposomes in in vivo tests. The rats were tested using I/R by clamping bilateral carotid arteries and different groups were treated with creatine (30 mg/kg) in free form (Liv+I/R) and liposomed (Lip+I/R) and compared with the control group and I/R. The animals motor activity, exploratory and memory abilities were evaluated through field tests and passive avoidance, 24 and 48 hours after I/R, respectively. After 72 hours, the animals were euthanized and the brains removed for biochemical determination of levels of reactive species and ascorbic acid (AA), and the biochemical breakdown activity of superoxide dismutase (SOD) and catalase (CAT). The suspensions of liposomes used for the in vivo treatment had homogenous average particle diameter (154 ± 6.9 nm), low polydispersity index (0.211 ± 0.019), pH near neutral (around 6.7), negative potential Zeta (-21 ± 1.8 mV) and association rate around 31%. The results of field tests have shown that I/R caused a change in exploratory activity of animals and increased oxidative stress in the brain of rats subjected to I/R. Liposomes creatine protected the change in exploratory activity and increased oxidative stress in rat cortex. Already in free form, creatine was not able to protect against these changes. With these results, we can conclude that the production of liposomes containing creatine technological feasibility presented, demonstrating the potential to increase the bioavailability of creatine into the CNS via the BBB. / A creatina é uma biomolécula sintetizada endogenamente a partir de aminoácidos, que também pode ser obtida através da dieta. Porém, ela não permeia facilmente através da barreira hematoencefálica (BHE), assim o cérebro deve suprir suas necessidades através da síntese de creatina no próprio sistema nervoso central (SNC). A grande importância da creatina para o funcionamento correto do organismo está em manter estáveis os níveis de adenosina trifosfato (ATP). Doenças neurodegenerativas levam a déficits de ATP, o que compromete o metabolismo celular, gerando espécies reativas (ERs) capazes de levar as células neuronais à morte. Assim, torna-se importante aumentar os níveis de creatina em doenças neurodegenerativas, podendo gerar novas alternativas de tratamento para estas doenças. Desta forma, o presente trabalho teve como objetivo desenvolver e caracterizar lipossomas de creatina, bem como, investigar o seu efeito protetor em um modelo de isquemia e reperfusão (I/R) cerebral. Foram utilizadas duas metodologias para o preparo dos lipossomas, a hidratação do filme lipídico e a injeção de etanol. Devido aos melhores resultados obtidos pelo método de injeção de etanol, este foi escolhido para o preparo dos lipossomas a serem aplicados nos testes in vivo. Os ratos foram submetidos ao processo de I/R pelo clampeamento bilateral das artérias carótidas, sendo os diferentes grupos tratados com a creatina (30 mg/kg) na forma livre (Liv+I/R) e lipossomada (Lip+I/R), sendo comparados com os grupos controle e I/R. A atividade locomotora, exploratória e a memória dos animais foram avaliadas através dos testes de campo aberto e da esquiva passiva, 24 e 48 h após a I/R, respectivamente. Após 72 h, os animais foram eutanasiados e os cérebros removidos para as determinações bioquímicas dos níveis de ERs e ácido ascórbico (AA), e a atividade das enzimas superóxido dismutase (SOD) e catalase (CAT). As suspensões de lipossomas utilizadas para o tratamento in vivo apresentaram diâmetro médio de partícula homogêneo (154 ± 6,9 nm), com baixo índice de polidispersão (0,211 ± 0,019), pH próximo a neutralidade (em torno de 6,7), potencial Zeta negativo (-21 ± 1,8 mV) e taxa de associação em torno de 31%. Os resultados do teste de campo aberto demonstraram que a I/R causou alteração na atividade exploratória dos animais. Além disso, o estudo demonstrou aumento no estresse oxidativo no cérebro de ratos submetidos a I/R. Os lipossomas de creatina protegeram a alteração na atividade exploratória e o aumento do estresse oxidativo em córtex de ratos. Já a creatina na forma livre não foi capaz de proteger contra estas alterações. Através destes resultados, pode-se concluir que a produção de lipossomas contendo creatina apresentou viabilidade tecnológica, demonstrando potencial para aumentar a biodisponibilidade de creatina para o SNC através da BHE.

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