published_or_final_version / abstract / Zoology / Master / Master of Philosophy

Certain strains of mice, e.g. C57BL/6, are highly resistant to serious infections with the protozoan pathogen, Leishmania major, whereas other strains, e.g. BALB/c, are not. It has beenproposed that interferon gamma (IFN-y) is one of the most critical lymphokines produced in a protective response to these intracellular pathogens. IFN-y has been classified as a Thi lymphokine produced by the Thl subset of T lymphocytes which not only activates macrophages to kill the protozoa but also helps regulates the immune system overall to form a lasting immunity to the microorganism (4,19). Mice susceptible to L. major arethought to produce inadequate amounts of IFN-y and instead produce an excessive amount of a Th2 lymphokine, IL-4, produced by Th2 T cells. (6) We have previously found that prophylactic treatment with cyclosporine A (CsA), a T cell specific immunosuppressant, reduces the susceptibility of the BALB/c to L. major by either preventing disease entirely or delaying itsdevelopment significantly (19). In this murine model, it may be that CsA causes a switch from the production of the less protective Th2 lymphokines to the more protective Thl lymphokines. In order to test this hypothesis we examined the IFN-y produced by lymph node and spleen cells over time after infection in three groups of mice: C57BL/6, BALB/c and cyclosporine- protected BALB/c. Interestingly, cells taken from all three groups of mice were able to secrete IFN-y in vitro in response to co-culture with Leishmania, antigens. The pattern of secretion over time, however, varied and may indicate a significant difference in the animals' response to the pathogen. In addition to this work, we also examined the ability of another immunosuppressant, FK506, which is very similar in action to but much less toxic than CsA, to induce enhanced resistence to L. major. FK506 also appears to be effective in reversing the susceptibility of the BALB/c mice towards this pathogen with much less apparent toxicity. / Department of Biology

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Σκοπός της συγκεκριμένης ερευνητικής εργασίας ήταν η αποσαφήνιση του ρόλου της Κυκλοσπορίνης στην πρόκληση νεφρικής ίνωσης, διαμέσου του συστήματος ΕΤ-1/ΝΟ. Για το λόγο αυτό πραγματοποιήθηκαν in vitro πειράματα, στα οποία χρησιμοποιήθηκαν ΗΚ-2 κύτταρα και διερευνήθηκε η επίδραση της κυκλοσπορίνης στην βιωσιμότητα των κυττάρων, στην παραγωγή ΝΟ, στην συσσώρευση των mRNA των et-1, etr-a, etr-b, enos και inos καθώς και τη συσσώρευση των αντίστοιχων πρωτεϊνών τους. Προέκυψε ότι η κυκλοσπορίνη τροποποιεί την έκφραση των γονιδίων et-1 και των υποδοχέων της etr-a και etr-b, των συνθετασών του ΝΟ, enos και inos, τη συσσώρευση των αντίστοιχων πρωτεϊνών, καθώς και του παραγόμενου NO. Επίσης, η αλβουμίνη δεν επηρεάζει τη συσσώρευση της ακτίνης, παρουσιάζει ωστόσο κυτταροτοξική δράση. / The aim of this research was the elucidation of the role of Cyclosporine in the induction of renal fibrosis, through the activation of the ET-1/NO system. We performed in vitro experiments using HK-2 cells (human proximal tubular epithelial cells) and we studied the impact of Cyclosporine on cell viability production of NO, expression of et-1, etr-a, etr-b, enos and inos and the accumulation of the subsequent proteins, as well as actin. Cyclosporine was found to alter the expression of et-1, etr-a, etr-b and enos and the accumulation of the subsequent proteins. Moreover, it affects the amount of the synthesized and secreted NO, while having no effect on the accumulation of actin.

No description available.

Prophylactic administration of the immunosuppressive drug cyclosporine A protects Balb/c mice from fatal Leishmania major infections. It is believed that distinct subpopulations of CD4+ T lymphocytes and their distinctive cytokines may determine susceptibility and resistance to leishmaniasis among inbred strains of mice. CsA may enhance disease resistance in Balb/c mice by modulating these T cell subsets and/or their cytokines. We have measured lymphoid cell production of IL-2, IL-4, and TNF-a in naturally resistant C57/Bl/6, CsA-treated Balb/c, and nontreated Balb/c mice during the course of L. major infection. CsA treatment inhibited IL-2 and IL-4 production for the first week of infection. Thereafter the cytokine production of all three groups of mice did not differ greatly except in week two when the treated mice produced significantly enhanced levels of IL-4. C57B1/6 mice did produce slightly more TNF-a than either group of Balb/c mice, but as the CsAprotected and diseased Balb/c mice produced similar amounts of this cytokine, the elevation in C57B1/6 animals probably reflects a strain-related difference rather than disease resistance. / Department of Biology

Thesis (Ph. D.)--University of Texas at Austin, 2004. / Supervisor: Lane J. Brunner. Vita. Includes bibliographical references. Also available from UMI.

Thesis (M. Phil.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

Thesis (M.S.)--University of Delaware, 2005. / Principal faculty advisor: Mary C. Farach-Carson, Dept. of Biological Sciences. Includes bibliographical references.

Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department: Pharmaceutical Chemistry and Drug Control Candidate: Zbyněk Mrůzek Supervisor: prof. RNDr. Jiří Klimeš. CSc Consultant thesis: Ing. Pavel Blatný. Ph.D. Title of thesis: Determination of related substances in the dosage forms based on cyclosporine by HPLC with nitrogen specific chemiluminescence detection. Development of an HPLC method with chemiluminescent detection specific for nitrogen for related substances determination in cyclosporine final dosage forms is described in this work. The method is capable to determine cyclosporine impurities originated from cyclosporine substance and relevant degradation products except isocyclosporines. The method utilizes the stationary phase Zorbax SB-C18, particle size 1.8 µm, 150x2.1 mm and gradient elution at flow rate 0.15 ml.min-1 at column temperature 100řC. Mobile phases are Acetone: TBME: water: TFA (30: 5.5: 64.5: 0.01) and Acetone: TBME: water: TFA (49: 5.5: 45.5: 0.01). The work includes the verification of method validability in terms of specificity, linearity, limit of quantittion, accuracy, precision and robustness. The method can be used for determination of cyclosporine impurities in final dosage forms in pharmacetical QC laboratories. Keywords: cyclosporine....