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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.
11

Desenvolvimento de processo de produção de fator VIII recombinante em biorreator. / Development of a process for recombinant factor VIII production in bioreactor.

Cássia Maria Ramaciotti de Andrade 14 August 2013 (has links)
A utilização de células humanas para a produção do fator VIII de coagulação recombinante (rFVIII) visa obter padrões de glicosilação equivalentes aos encontrados na proteína normal. O objetivo do trabalho foi obter um processo de produção do rFVIII em biorreator em perfusão, devido à sua labilidade térmica. Foram realizados estudos preliminares em Spinner e biorreator utilizando uma linhagem de rHeLa, cujos resultados embasaram os estudos com a linhagem produtora rSkHep. Foram utilizados microcarregadores nos cultivos com esta linhagem devido à dificuldade de adaptação da mesma à suspensão. Ensaios preliminares identificaram a melhor condição de cultivo com 3 g/L Mic e 1 cel/mic e, a partir destes valores, realizou-se um ensaio em perfusão, com tempo de residência de 24 h, no qual as variáveis controladas foram mantidas constantes durante três tempos de residência. A concentração de rFVIII obtida foi semelhante 2 UI/ mL. / The interest in using human cells for the recombinant coagulation factor VIII (rFVIII) lies in obtaining glycosylation patterns similar to the ones found in the normal protein. The objective of this work was to obtain a process for rFVIII production in bioreactor, in perfusion mode, due to the thermal lability of the protein. Using a recombinant HeLa cell line adapted to suspension growth a group of studies in a bioreactor in batch mode were performed. These results were the basis for the studies performed with the producing cell line rSkHep. Microcarriers (micc) were used due to the harshness to adapt the cell line to suspension and to serum-free medium. Preliminary tests identified the best culture condition with 3 g micc/L and 3 cell/micc and, from its values, it was performed a bioreactor study in perfusion mode, with a residence time of 24 hours. The controlled variables were kept constant for three residence times. The maximum rFVIII concentration obtained was 2 UI/mL.
12

Avaliação de indução de resposta imunológica ao fator VIII da coagulação humano recombinante no modelo murino de hemofilia A. / Immunogenicity evaluation of recombinant clotting factor VIII in a murine model of hemophilia A.

Erika de Simone Molina 26 August 2013 (has links)
O fator VIII da coagulação é utilizado para o tratamento da hemofilia A e pode ser obtido a partir de concentrados do plasma humano ou na sua forma recombinante (rFVIII). Nosso laboratório tem explorado uma alternativa mais eficiente para a produção do rFVIII em células de mamíferos, utilizando um variante artificial do rFVIII humano (rFVIII-lab). O objetivo principal deste trabalho foi avaliar a imunogenicidade do rFVIII-lab utilizando camundongos modelo da hemofilia A, tendo como objetivos experimentais a purificação, caracterização de atividade funcional in vivo e caracterização de imunogenicidade do rFVIII-lab comparada a produtos de referência, um derivado de plasma e outro recombinante. Os resultados indicam que o perfil de imunogenicidade observado para o rFVIII-lab foi menos intenso e a atividade funcional observada foi similar quando comparado aos produtos de referência. A expectativa é que o presente estudo contribua para o estabelecimento de uma plataforma de produção do rFVIII no país visando o tratamento dos pacientes hemofílicos brasileiros. / Factor VIII (FVIII) replacement therapy employing either FVIII concentrates from blood plasma or recombinant FVIII is the standard of care for management of hemophilia A. Our group has been exploring a more efficient alternative for recombinant FVIII production in mammalian cells employing an engineered artificial variant of the protein (rFVIII-lab). The main objective of this study was to evaluate the immunogenicity of the rFVIII-lab using a murine model of hemophilia A and the specific experimental objectives were to purify, evaluate the in vivo functional activity and the immunogenicity of rFVIII-lab compared to plasma derived and recombinant reference products. Data revealed reduced immunogenicity of rFVIII-lab whereas functional activity was similar when compared to the reference products. The presented study is expected to contribute to the establishment of a locally production platform for the rFVIII aiming at the treatment of Brazilian hemophilic patients.
13

Identifizierung von agonistischen und invers agonistischen Eigenschaften determinierender Strukturen in Liganden am ADP-Rezeptor P2Y12

Schmidt, Philipp 18 December 2013 (has links)
Die vorliegende Arbeit untersucht die strukturellen Grundlagen agonistischer und invers agonistischer Eigenschaften von Liganden am ADP-Rezeptor P2Y12. Dazu wurde eine Bibliothek systematisch veränderter Purinverbindungen am Wildtyp-P2Y12 (WT) mit und ohne ADP und an 28 konstitutiv aktiven P2Y12-Mutanten getestet. Dies ermöglichte die pharmakologische Zuordnung der Substanzen als Agonist, Antagonist oder inverser Agonist. Die Untersuchungen wurden in einem Hochdurchsatz-Hefe-Expressionssystem in Hefen durchgeführt. Als agonistische Liganden am P2Y12 Rezeptor konnten verschiedene ATP und ATP-Derivate identifiziert werden. Ihre agonistische Potenz am ADP-Rezeptor reihte sich wie folgt: 2-(methylthio)-ADP > 2-(methylthio)-ATP > ADP > ATP. In Dockingstudien wurde mittels eines komparativen Computermodels des P2Y12 für diese ATP-Derivate eine Bindungsstelle nachgewiesen, die von den Transmembrandomänen (TM) 3, 5, 6 und 7 gebildet wird. Die Aminosäuren Y105, E188, R256, Y259 und K280 besitzen in der Ligandeninteraktion einen besonderen Stellenwert. Zudem konnten einige Liganden identifiziert werden, die invers agonistische Eigenschaften an konstitutiv aktiven P2Y12-Mutanten zeigten. So führte eine N-Methyl-anthraniloyl-(mant) Modifizierung an der 3’-OH Gruppe der 2’-Deoxyribose (mant-dATP, mant-dADP) zu Liganden mit invers agonistischen Eigenschaften an 10 konstitutiv aktiven P2Y12-Mutanten. Diese Wirkung konnte mittels verschiedener funktioneller Tests in Säugerzellsystemen ebenfalls für den WT-Rezeptor bestätigt werden. Basierend auf den Ergebnissen computerassistierter Dockingstudien schienen inverse Agonisten und Agonisten dieselbe Bindungstasche zu nutzen. Eine mechanistische Erklärung für ihren funktionellen Unterschied am WT konnte das Modell jedoch nicht liefern. Zusammenfassend wurde gezeigt, dass der als ADP-Rezeptor bezeichnete P2Y12 mit einer etwas geringeren Potenz auch ATP als natürlichen Agonist erkennt und dass mant-modifiziertes dATP und dADP neue inverse Agonisten mit potenziellem therapeutischem Nutzen sind.
14

Comparative Stability of Oral Vitamin K Liquids Stored in Refrigerated Amber Plastic Syringes

Huffman, Jessica, Brown, Stacy D., Lewis, Paul O, Lawson, Sarah, Ogle, Amanda P., Peacock, Gina 01 January 2018 (has links)
The purpose of this study was to evaluate the stability of vitamin K1 oral liquids in Sterile Water for Injection when stored in amber glass bottles and amber plastic syringes under refrigerated conditions. Four 100-mL batches of vitamin K1 in Sterile Water for Injection were prepared in amber glass bottles to protect from light. One of the batches was divided into 1-mL aliquots, using amber plastic oral syringes, and capped. The prepared bottles and syringes were stored in a laboratory refrigerator. On each day of sampling, 1-mL aliquots were removed from each bottle and mixed with an equal volume of ethanol. Likewise, the contents of sample syringes were mixed with ethanol to achieve an assay concentration of 0.5 mg/mL. Recovery of vitamin K1 in the compounded samples was quantified against a United States Pharmacopeia reference standard. Quantification was achieved using a stability-indicating high-performance liquid chromatography with ultraviolent light detection method. Product stability is defined as 90% to 110% of the initial concentration. The percent recovery in the Sterile Water for Injection preparations in glass bottles remained above 90% for the 105-day duration of the study, but some samples stored in amber plastic syringes fell below 90% on day 21. Furthermore, a statistically significant difference (2-way ANOVA, P < 0.0001) emerged between syringes at day 0 and day 30, and this trend continued through the day 60, 90, and 105 samples. The only statistically significant difference found within the bottle-stored samples occurred on day 105 (versus zero, P = 0.0465), but the recovery on day 105 still exceeded 90%. Vitamin K1 in Sterile Water for Injection, stored in a refrigerated amber glass bottle, is stable for 105 days. This preparation can also be stored in amber plastic syringes, but this decreases the beyond-use date to 14 days.
15

Påverkan på PK(INR)-värdet efter olika preanalytiska behandlingar i venöst humanblod.

Khashayar, Mahdavisabet January 2015 (has links)
Venous thromboembolism that cause blood clotting in blood vessels, prevent blood circulation, depending on changes in one or more of the coagulation factors II, VII, IX and X. Patients who have had a blood clot or cardiovascular diseases are treated with oral anti-vitamin K (Warfarin®) to reducing and prevent relapse. Warfarin is also used as a preventive treatment before the disease. An overdose of Warfarin® may cause bleeding-complications and low dose cause blood clotting. The dosage of the drug is controlled by measuring prothrombin in plasma. The aim of this study was to investigate if prothrombin-complex value changes due to re-spinning and re-analysis after six hours. Fitty whole blood samples from warfarin-treated patients were divided into three subgroups, those with protrombinkomplex-values of 2-4 (n=20), &gt;4 (n=15) and &lt;2 (n=15). The samples were centrifugated and measured (Method A), re-centrifugated and measured (Method B) or re-analysed after six hours (Method C). All results were compared in a Bland-Altman plot as follows: Method B vs. Method A and Method C vs. Method A. The scatter graph yielded a strong correlation between Method A and Method B (R2=0.9984) and Method A and Methods C (R2=0.9977). The results from t-test showed a significance level (p&lt;0.001) for both analyses (statistical significance=p&lt;0.05). In this study we showed that prothrombin complex value ware stable after re-centrifugation and re-measurement after six hours. Statistical calculations yielded a strong correlation between the methods (A, B, C), and there was no significance difference between the methods.

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