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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.

Studies toward the asymmetric total synthesis of mitomycin Cpdn

Chen, Wei, January 2003 (has links)
Thesis (Ph. D.)--Ohio State University, 2003. / Title from first page of PDF file. Document formatted into pages; contains xiii, 266 p.: ill. Includes abstract and vita. Advisor: Robert S. Coleman, Dept. of Chemistry. Includes bibliographical references (p. 208-222).


Dorr, Robert Thomas January 1984 (has links)
A series of studies in mice were performed to determine the interaction of two sulfur nucleophiles, oral n-acetylcysteine (NAC) and intravenous sodium thiosulfate (Na₂S₂O₃) with the anticancer drug mitomycin C (MMC). Neither nucleophile reduced MMC lethality or hematopoietic toxicity. Both increased the antitumor activity of MMC in mice bearing P-388 and L-1210 leukemias. There was no nucleophile reduction of MMC effects on normal bone marrow stem cells (CFUs) using a murine spleen colony forming assay. In contrast, the nucleophiles significantly enhanced MMC bone marrow toxicity. Three clonogenic human tumor cell lines (HEC-1A endometrial, 8226 myeloma, WiDr colon) were relatively resistant to MMC and the nucleophiles did not increase activity. A human breast cancer cell line (MCF-7) was sensitive to MMC and this activity was blocked by glutathione. Oxygen free radical scavengers did not reduce MMC activity. A novel isocratic high performance liquid chromatography (HPLC) assay (48:52, methanol:0.01M phosphate buffer) using ultraviolet detection at 365 nm was used to characterize MMC-protein binding and murine pharmacokinetics. The k' for MMC was 7.91 and 9.86 for porfiromycin. Peaks were confirmed by mass spectroscopy. MMC was bound 30% to albumin and S-9 microsomal proteins and 60-70% to calf thymus DNA. MMC uptake into mouse bone marrow was enhanced by the nucleophiles and was rapidly cleared from the plasma (half-life 0.5 hours). In vitro MMC metabolism with rat liver S-9 microsomes demonstrated production of a polar eluting, putative MMC metabolite (K' = 4.486, lambda maximum 300 nm). This metabolite was inactive in the in vitro clonogenic tumor cell assay. Finally, molecular pharmacology studies using alkaline DNA elution showed that MMC causes both DNA-DNA and DNA-protein crosslinks. There was no evidence for free radical-induced DNA strand scission by MMC. There was also some evidence of moderate DNA protection with the sulfur nucleophiles.

Studies towards enantioselective synthesis of mitomycins

Gu, Qiangshuai, 顧強帥 January 2013 (has links)
published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

Geschlechts-chromosomale Kopplung der Fanconi Anämie Gene FANCC und FANCG im Hühnergenom und die geschlechtsspezifische Sensibilität der Hühnerzellen gegenüber Mitomycin C / Sex-chromosomal linking of Fanconis Anemia gene FANCC and FANCG in chicken and gender-related sensibility to mitomycin C.

Buwe, Andrea January 2013 (has links) (PDF)
Fanconi Anämie ist eine seltene rezessiv vererbte Erkrankung, deren zu Grunde liegende Enzymdefekte in ein Netzwerk unterschiedlichster DNA-Reparaturproteine eingewoben sind. Phylogenetisch sind uns Vögel relativ nahe verwandt, was sie zu einem guten Modellorganismus jenseits der Säugetiermodelle macht. Eine von Hühnerzellen abgeleitete Zelllinie (DT40) wurde bereits schon breit eingesetzt um die Funktion des FA-Signalwegs zu erforschen. Nachdem auch das Hühnergenom vollständig entschlüsselt wurde, konnten zu fast allen FA-Genen Orthologe gefunden werden. Unter den zahlreichen FA-Genen sind für diese Arbeit vor allem FANCC und -G von Bedeutung, da beide Gene auf dem Z-Geschlechtschromosom des Huhns liegen und eine Inaktivierung des zweiten Z-Chromosoms beim Hahn äquivalent zur X-Inaktivierung beim Menschen nicht stattfindet. Somit sollte es ein ´natürliches´ Gendosisungleichgewicht zwischen den Geschlechtern geben. Im durchgeführten Southern Blot konnte keine geschlechtsspezifisch weibliche Bande (für FANCC und -G) gefunden werden. Somit ist davon auszugehen, dass die FA-Gene C und G ausschließlich auf dem Z-Chromosom lokalisiert sind. Dies wurde auch nochmals mittels FISH bestätigt - beide Gene fanden sich auf dem kurzen Arm des Z-Chromosoms (FANCC zentromernah, FANCG zentromerfern). Aus Studien mit DT40 Zellen ist bereits bekannt, dass FA defiziente Zellen ähnlich wie humane FA-Zellen eine Hypersensitivität gegenüber Substanzen zeigen, die DNA-crosslinks verursachen. In Anlehnung an die humane FA-Diagnostik wurden die neu etablierten embryonalen Fibroblasten mit unterschiedlichen Konzentrationen und Einwirkzeiten von MMC behandelt und die Schäden ausgewertet. In allen Untersuchungen trugen die weiblichen Zellen mehr Schäden davon als die männlichen. Bei niedrigen Konzentrationen zeigte sich dies nur als Trend, bei höheren MMC-Konzentrationen und längeren Einwirkzeiten fanden sich bei fast allen durchgeführten Untersuchungen auch statistisch signifikante Unterschiede. Somit ergibt sich aus dieser Arbeit ein deutlicher Hinweis auf ein funktionelles Ungleichgewicht zwischen Henne und Hahn was die DNA-Reparatur nach Schädigung durch MMC angeht. / Fanconi anemia is a rare recessive disorder whose underlying enzyme deficiencies are woven into a network of various DNA repair proteins. Phylogenetically related birds are relatively close to us, which makes it a good model organism beyond the mammalian models. A cell line derived from chicken cells (DT40) has already been widely used to study the FA pathway. Even after the chicken genome was completely decoded, orthologs could be found for almost all FA genes. Among the numerous FA genes are mainly FANCC and G of importance since both genes are located on the Z sex chromosome of chicken. An inactivation of the second Z chromosome as the inactivation of the x chromosom in human does not take place. Thus there should be a 'natural' imbalance of the gen dose between the sexes. Southern blot showed no gender female band (for FANCC and G). Thus it can be assumed that the FA genes C and G are exclusively localized on the Z chromosome. This was also confirmed by FISH, both genes were located on the short arm of the Z chromosome. From studies in DT40 cells is already known that FA deficient cells, similar to a human FA cell show hypersensitivity to substances that cause DNA crosslinks. Based on the human FA diagnosis, newly established embryonic fibroblasts were treated with different concentrations of MMC and chromosomal the damage was evaluated. In all studies, the female cells contributed more damage than the male. At low concentrations, this was only shown as a trend, at higher MMC concentrations and longer exposure times there was a significant differences. Thus, results from this study, a clear indication of a functional imbalance between hen and rooster in terms of DNA repair after damage by MMC.


CASNER, MICHAEL LAWRENCE. January 1984 (has links)
Novel mitosenes substituted at the 6-position were synthesized for antineoplastic screening. More than 26 new compounds were made by two synthetic routes. A Nenitzescu-type synthesis provided ethyl 1-acetoxy-2,3-dihydro-5,8-dione-7-methoxy-1H-pyrrolo{1,2-a}indole-9-carboxylate. However, selective reduction of this ester could not be achieved satisfactorily. A more practical route via annelation of a commercially available indole was successful in completing the planned scheme of 6-substituted mitosene congeners. The third ring (pyrrolidine) was added by condensation of ethyl acrylate with ethyl 5-methoxyindole-2-carboxylate. After decarboxylation at position 2, the ketone at position 1 was reduced and acetylated. Then the carbon at the 9 position was introduced by Vilsmeier-Haack formylation and the quinone moiety was synthesized via a nitration, reduction, and oxidation sequence. Subsequently, the aldehyde was most satisfactorily reduced to an alcohol with sodium borohydride and the quinone was regenerated with Fremy's salt. 1-acetoxy-6-desmethyl-7-methoxymitosene was made by forming a carbamate at position 9 by treatment of the 9-alcohol with phenyl chloroformate and displacing the phenoxy group with ammonia. Other 1,6,7-substituted mitosene congeners were made using N-methylcarbamate formation via methyl isocyanate and the 9-alcohol. The 6-chloro and 6-bromo analogs were formed by treatment of the 6-H congener, 1-acetoxy-2,3-dihydro-5,8-dioxo-9-(hydroxymethyl)-7-methoxy-1H-pyrrolo{1,2-a}indole methylcarbamate, with the desired halogen in acetic acid and sodium acetate. The 7-methoxy group could be displaced by ammonia for the 6-bromo compound and by pyrrolidine for the 6-H compound to form respectively the 7-amino-6-bromo and 7-pyrrolidino-6-H 1-acetoxy-2,3-dihydro-5,8-dioxo-9-(hydroxymethyl)-1H-pyrrolo{1,2-a}indole methylcarbamates. The 6-methyl analog (1-acetoxy-7-methoxy-N-methyl-carbamoylmitosene) was made from a previously synthesized precursor. Attempted syntheses of the 6-azido and 6-amino analogs by displacing the 6-bromo substituent with sodium azide were met by gross rearrangement of the resulting adducts. Preliminary antitumor screening against P388 leukemia in mice showed these analogs to be too inactive for use as antineoplastic agents. The 6-methyl substituent was shown to be most potent in bacteriophage induction in E. coli for this series of 6-substituted mitosene analogs.

Primary viscocanalostomy versus mitomycin-C augmented trabeculectomy in patients with open-anle glaucoma: a randomized clinical trial

Williams, Susan Eileen IsabellaI 08 September 2009 (has links)
M.Med. Faculty of Health Sciences, University of the Witwatersrand, 2009 / Purpose To compare the outcomes of primary viscocanalostomy with trabeculectomy augmented with mitomycin C (MMC) in black South African patients with primary open-angle glaucoma (POAG). Method A prospective, randomized study was conducted over a four year period. Fifteen black South African patients with bilateral open-angle glaucoma requiring surgery that met the inclusion criteria and gave informed consent to participate in the trial were randomized to receive either a viscocanalostomy or a trabeculectomy with MMC in the first eye requiring surgery. The fellow eye then received the alternate procedure. Patients were followed up for two years postoperatively. Results There were no significant differences between the two surgical groups preoperatively. Twelve eyes in each group were followed for twenty-four months. In both groups the intraocular pressure (IOP) was significantly reduced post-operatively (p < 0.01) and the average number of medications used per eye was significantly reduced (p < 0.02). At twenty-four months, complete success (IOP less than or equal to 18mmHg without glaucoma medication and with no evidence of glaucoma progression) was seen in 75% of eyes undergoing trabeculectomy with MMC that completed the follow up, but in only 33% of eyes undergoing viscocanalostomy (p = 0.0498). Survival curves for both success and qualified success (IOP less than or equal to 18mmHg with glaucoma medications) in the two surgical procedures confirmed the superiority of trabeculectomy with MMC over viscocanalostomy. Conclusion Viscocanalostomy may offer some advantages because it is less invasive, but intraocular pressure control appears to be superior with trabeculectomy with MMC and this continues to be the filtering procedure of choice for the management of glaucoma in black South African patients.

Immunohistochemical analysis of NAD(P)H:quinone oxidoreductase and NADPH cytochrome P450 reductase in human superficial bladder tumours: Relationship between tumour enzymology and clinical outcome following intravesical mitomycin C therapy

Phillips, Roger M., Basu, S., Gill, Jason H., Loadman, Paul M. 27 May 2009 (has links)
A central theme within the concept of enzyme-directed bioreductive drug development is the potential to predict tumour response based on the profiling of enzymes involved in the bioreductive activation process. Mitomycin C (MMC) is the prototypical bioreductive drug that is reduced to active intermediates by several reductases including NAD(P)H:quinone oxidoreductase (NQO1) and NADPH cytochrome P450 reductase (P450R). The purpose of our study was to determine whether NQO1 and P450R protein expression in a panel of low-grade, human superficial bladder tumours correlates with clinical response to MMC. A retrospective clinical study was conducted in which the response to MMC of 92 bladder cancer patients was compared to the immunohistochemical expression of NQO1 and P450R protein in archived paraffin-embedded bladder tumour specimens. A broad spectrum of NQO1 protein levels exists in bladder tumours between individual patients, ranging from intense to no immunohistochemical staining. In contrast, levels of P450R were similar with most tumours having moderate to high levels. All patients were chemotherapy naïve prior to receiving MMC and clinical response was defined as the time to first recurrence. A poor correlation exists between clinical response and NQO1, P450R or the expression patterns of various combinations of the 2 proteins. The results of our study demonstrate that the clinical response of superficial bladder cancers to MMC cannot be predicted on the basis of NQO1 and/or P450R protein expression and suggest that other factors (other reductases or post DNA damage events) have a significant bearing on tumour response.

Comparison of Cyclosporin A with Mitomycin C and gamma irradiation as inactivators of stimulator cells in the one-way mixed lymphocyte reaction

Stivaktas, Paraskevi Irene 20 May 2009 (has links)
The one-way mixed lymphocyte culture (MLC) is used to assess histocompatibility between donor and recipient. First introduced in 1966, this method involves the co-culture of lymphocytes from the peripheral blood of the donor and the recipient for a period of 6 to 7 days: antigen disparities, primarily in the HLA-DR region, stimulate proliferation of the responding cells, which is detected by addition of 3H-labelled thymidine and subsequent measurement of radioactivity. The lymphocytes of either the donor, used to predict graft-versus-host disease (GVHD) or recipient, used to predict host-versus-graft disease (HVGD)/graft rejection, are inactivated by exposure to radiation or mitomycin C, so that the observed proliferation is that of the other set of lymphocytes, hence the name “one-way” MLC. The amount of measured radioactivity is directly proportional to the amount of DNA synthesized, which is a reflection of the number of disparities at the major histocompatibility complex (MHC).Previous studies have established that inactivation of the lymphocytes by radiation and mitomycin C, has a negative effect on the structure/expression of HLA-DR molecules on the cell surface, which provides the primary stimulus for the MLC reaction. The laboratory research presented in this dissertation was designed i) to compare the viabilities and HLA-DR levels on stimulator cells exposed to cyclosporin A, mitomycin C and ionizing irradiation , in order to determine whether cyclosporin A can be used as an alternative to mitomycin C or radiation as inactivator of the stimulator cells in the one-way MLC; ii) to improve sensitivity and accelerate the MLC reaction by addition of IL-2; iii) establish a flow cytometric mixed lymphocyte assay using the fluorochrome 5,6 carboxyfluorescein diacetate succinimidyl ester (CFSE). Cyclosporin A showed striking similarities to mitomycin C and ionizing radiation in its effect on viability and reduction/structural changes in HLA-DR molecules of the stimulator cells. Exposure of the stimulator cells to 20ìM cyclosporin A, demonstrated a significant loss of both cell viability and HLA-DR molecule cell surface expression. Thus, in evaluating these three methods of inactivation of the stimulator cells in the one-way MLC, it was concluded that a one-way MLC may not in fact be an accurate and qualitative reflection of the histocompatibility between donor and recipient. Instead the two-way MLC , in which neither the donor’s nor recipient’s cells are inactivated, may be a more reliable alternative. The only limitation associated with a two-way MLC is the inability to distinguish between a host-versus-graft-rejection and a graft-versus-host reaction in the observed allogeneic response Addition of 5 and 10 IU/ml IL-2 to the MLC showed the opposite effect to that intended, inhibiting proliferation in the MLC. Previous studies have shown that an excess of IL-2 results in the production of suppressor T cells. The amount of IL-2 produced during the MLC depends on the number of disparities in the MLC between donor and recipient, which will be different for each MLC reaction. Since the number of allogeneic T cells involved in the MLC reaction is not known, the amount of IL-2 produced during the allogeneic immune response in the MLC can not be predicted and addition of exogenous IL-2 may result in production of suppressor T cells and an inhibition of proliferation. The two-way MLC was modified by staining one of the participating set of lymphocytes (donors or recipients) with CFSE and tracking proliferation in this population, using flow cytometry. The two-way CFSE-based MLC analyzed in this study were counterstained with CD25 (IL-2R). An increase in CD25 expression on the cell surface is an indicator of cell activation and proliferation. Proliferation, as indicated by a progressive loss of CFSE fluorescence correlated well with the corresponding increase in CD25 expression and accumulated daughter cells. In addition, by loading only one of the participating donors in the two-way MLC, the responder/stimulator interaction, observed in the one-way MLC, is re-established. Thus the modified, CFSE-based two-way MLC can be used to predict GVHD. To conclude, the use of CFSE labeling and flow-cytometry to measure proliferation in a two-way MLC, together with CD25 counterstaining provides an alternative, reliable and probably superior method to 3H thymidine uptake. / Dissertation (MSc)--University of Pretoria, 2009. / Immunology / unrestricted

Efeitos da administração tópica per-operatória da mitomicina C, em diferentes concentrações, sobre a cicatrização de mioplastias do reto dorsal do bulbo do olho de coelhos

Mamede, Fabrício Villela [UNESP] 28 February 2007 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:31:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-02-28Bitstream added on 2014-06-13T20:21:58Z : No. of bitstreams: 1 mamede_fv_dr_jabo.pdf: 467286 bytes, checksum: f692f69fc0d5d4f1a73028aaad9d672a (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Fundação para o Desenvolvimento da UNESP (FUNDUNESP) / Mioplastias extra-oculares podem ensejar aderências entre o músculo operado e os tecidos adjacentes, produzindo, não raro, estrabismos cicatriciais. Com intuito de se minimizar a ocorrência de aderências, investigaram-se os efeitos da mitomicina C (MMC), um antifibrótico, em concentrações ascendentes de 0,008, 0,02 e 0,04%, aplicada no per-operatório de mioplastias do reto dorsal do bulbo do olho de coelhos. Para tal, foram operados 56 animais, os quais foram divididos em sete grupos. Para o pós-operatório, instituíram-se limpeza com solução fisiológica das áreas operadas, profilaxia antimicrobiana e antiinflamatória, na forma de colírio. Procederam-se avaliações clínica, histológica, morfométrica e quanto à imunoistoquímica, em que se estudou o Fator de Crescimento Fibroblástico-básico (FGF-2). Encontraram-se, clinicamente, mais aderências nos olhos controle, comparativamente aos tratados, no entanto, sem significação estatística (p>5%). À histologia, verificou-se que a MMC ensejou retardo da cicatrização junto às áreas das mioplastias, notadamente no grupo que a recebeu, à concentração de 0,02%. A imunoistoquímica revelou marcação do FGF-2 em fibroblastos e macrófagos, indistintamente, entre os grupos. Com base nos resultados, permite-se admitir que a MMC, nas concentrações em que fora empregada, foi capaz de retardar a cicatrização e, por conseguinte, o estrabismo secundário, sem ensejar efeitos colaterais. / Extraocular myoplasties may cause adhesions to adjacent tissues, resulting cicatricial strabismus. With the purpose of reducing to a minimum the occurrence of adhesion, we studied the effects of mitomycin C (MMC), an antifibrotic, in concentrations of 0,008%, 0,02%, and 0,04% applied during intraoperative of myoplasties of the superior rectus muscle of laboratory albine rabbits. Fifty six animals were operated on and were divided in seven groups. During the postoperative the operated areas were cleaned with physiological solution. Eyedrop instillation to prevent inflammation and bacterial infection were used. The method to analyze the results consisted of clinical and histological evaluation and statistical analyzes. We also evaluated at the same time the amount of basic fibroblast growth factor (FGF-2) by immunohistochemical study. Clinically we found more adhesions in the eyes of the control group than in the groups of treated eyes. However there was no significant statistics difference between the two groups (p>5%). Histologically we found that MMC caused a delayed cicatrization in the mioplastic areas, specially in the group who received the 0,02% concentration. The immunohistochemical showed FGF-2 marking in fibroblasts and macrophages, but between the groups there wasn’t no difference. Based on those results we conclude that MMC in the utilized concentrations was capable of delaying the cicatrization and consequently avoid the secondary strabismus without undesirable side effects.

A novel strategy for NQO1 (NAD(P)H:quinone oxidoreductase, EC mediated therapy of bladder cancer based on the pharmacological properties of EO9.

Choudry, Guzanfar A., Hamilton Stewart, P.A., Double, John A., Krul, M.R.L., Naylor, Brian, Flannigan, G. Michael, Shah, Tariq K., Phillips, Roger M. January 2001 (has links)
No / The indolequinone EO9 demonstrated good preclinical activity but failed to show clinical efficacy against a range of tumours following intravenous drug administration. A significant factor in EO9's failure in the clinic has been attributed to its rapid pharmacokinetic elimination resulting in poor drug delivery to tumours. Intravesical administration of EO9 would circumvent the problem of drug delivery to tumours and the principal objective of this study is to determine whether or not bladder tumours have elevated levels of the enzyme NQO1 (NAD(P)H:quinone oxidoreductase) which plays a key role in activating EO9 under aerobic conditions. Elevated NQO1 levels in human bladder tumour tissue exist in a subset of patients as measured by both immunohistochemical and enzymatic assays. In a panel of human tumour cell lines, EO9 is selectively toxic towards NQO1 rich cell lines under aerobic conditions and potency can be enhanced by reducing extracellular pH. These studies suggest that a subset of bladder cancer patients exist whose tumours possess the appropriate biochemical machinery required to activate EO9. Administration of EO9 in an acidic vehicle could be employed to reduce possible systemic toxicity as any drug absorbed into the blood stream would become relatively inactive due to an increase in pH.

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