Tse Kai Kong. / Thesis submitted in: August 1998. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves 116-122). / Abstract also in Chinese. / ABSTRACT --- p.ii / 摘要 --- p.v / ACKNOWLEDGEMENTS --- p.viii / CONTENTS --- p.ix / LIST OF FIGURES --- p.xiii / LIST OF TABLES --- p.xvii / ABBREVIATIONS --- p.xix / Chapter CHAPTER ONE --- Introduction --- p.1 / Chapter 1 --- Introduction --- p.2 / Chapter 1.1 --- Definition and Prevalence of Epilepsy --- p.2 / Chapter 1.2 --- Neurophysiology and Pathophysiology of Epilepsy --- p.3 / Chapter 1.3 --- Drugs Currently Used in the Treatment of Epilepsy --- p.5 / Chapter 1.4 --- Triazolines Aminoalkylpyridines as a New Class of Potential Antiepileptic Drugs --- p.9 / Chapter 1.5 --- Chemical Synthesis of Aminoalkylpyridines --- p.14 / Chapter 1.6 --- Metabolism of Aminoalkylpyridines --- p.15 / Chapter 1.7 --- Anticonvulsant Activities of Aminoalkylpyridines --- p.16 / Chapter 1.8 --- Aim and Scope of the Present Study --- p.18 / Chapter CHAPTER TWO --- Experimental --- p.19 / Chapter 2.1 --- MATERIALS --- p.20 / Chapter 2.2 --- PREFORMULATION STUDIES ON AMINOALKYLPYRIDINES --- p.22 / Chapter 2.2.1 --- Determination of Partition Coefficient --- p.22 / Chapter 2.2.2 --- Determination of Aqueous Solubilities --- p.22 / Chapter 2.2.3 --- Determination of Thermal Properties --- p.23 / Chapter 2.3 --- DEVELOPMENT OF A HIGH PERFORMANCE LIQUID CHROMATOGRAPHIC ASSAY FORp-C1 AMINOALKYLPYRIDINES --- p.24 / Chapter 2.3.1 --- HPLC Apparatus and Conditions --- p.24 / Chapter 2.3.2 --- Animal Treatments and Biological Fluid Collection --- p.24 / Chapter 2.3.3 --- Solid Phase Extraction --- p.25 / Chapter 2.3.4 --- Construction of Calibration Curves for p-Cl AAP in Rat Blood --- p.25 / Chapter 2.3.5 --- Construction of Calibration Curves for p-Cl AAP in Rat Urine --- p.26 / Chapter 2.3.6 --- Accuracy and Precision in the Quantitation of p-C1 AAP in Biological Fluids --- p.26 / Chapter 2.4 --- PRELIMINARY PHARMACOKINETICS OF p-C1 AAP FOLLOWING INTRAVENOUS ADMINISTRATION --- p.27 / Chapter 2.4.1 --- Cannulae Preparation --- p.27 / Chapter 2.4.2 --- Dosage --- p.27 / Chapter 2.4.3 --- Animal Surgery and Sample Collection --- p.28 / Chapter 2.4.4 --- Pharmacokinetic Calculations --- p.29 / Chapter 2.5 --- URINARY METABOLIC STUDIES OF p-C1 AAP --- p.30 / Chapter 2.5.1 --- Animal Treatment and Urine Collection --- p.30 / Chapter 2.5.2 --- Deconjugation Assay --- p.30 / Chapter 2.5.3 --- Non-deconjugated Urine Sample Treatment --- p.31 / Chapter 2.5.4 --- Separation of Metabolites by HPLC --- p.31 / Chapter 2.5.5 --- Identification of Metabolites by LC/MS --- p.31 / Chapter 2.5.6 --- Quantitative Analysis --- p.32 / Chapter 2.5.7 --- Preparation of the authentic β-amino alcohol --- p.34 / Chapter 2.6 --- STATISTICAL ANALYSIS --- p.34 / Chapter CHAPTER THREE --- Results and Discussion --- p.35 / Chapter 3.1 --- PREFORMULATION STUDIES ON AMINOALKYLPYRIDINES --- p.36 / Chapter 3.1.1 --- PARTITION COEFFICIENT (K°W) --- p.36 / Chapter 3.1.2 --- AQUEOUS SOLUBILITY --- p.37 / Chapter 3.1.3 --- THERMAL ANALYSIS --- p.41 / Chapter 3.2 --- DEVELOPMENT OF A HIGH PERFORMANCE LIQUID CHROMATOGRAPHIC ASSAY FOR p-C1 AMINOALKYLPYRIDINES --- p.49 / Chapter 3.2.1 --- SOLID PHASE EXTRACTION --- p.49 / Chapter 3.2.2 --- CONSTRUCTION OF CALIBRATION CURVES FOR p-C1 AAP IN THE RAT BLOOD --- p.49 / Chapter 3.2.3 --- CONSTRUCTION OF CALIBRATION CURVES FOR p-C1 AAP IN THE RAT URINE --- p.52 / Chapter 3.2.4 --- ACCURACY AND PRECISION IN THE QUANTITATION OF p-Cl IN THE BIOLOGICAL FLUIDS --- p.54 / Chapter 3.3 --- PRELIMINARY PHARMACOKINETICS OF p-C1 AAP FOLLOWING INTRAVENOUS ADMINISTRATION --- p.57 / Chapter 3.4 --- URINARY METABOLIC STUDIES OF p-C1AAP --- p.61 / Chapter 3.4.1 --- QUALITATIVE STUDIES : IDENTIFICATION OF METABOLITES --- p.61 / Chapter 3.4.2 --- QUANTITATIVE STUDIES --- p.94 / Chapter CHAPTER FOUR --- Conclusion --- p.111 / REFERENCES --- p.115 / APPENDIX Published Papers --- p.121

by Anthony Tak Cheung Chan. / "March 1998." / Thesis (M.D.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (p. 200-242). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstract in Chinese.

Pang, Lap-yin. / "42" in title is subscript. / "July 2000." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (p. 163-173). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

The use of drug combinations (DCs) in cancer therapy can prevent the development of drug resistance and decrease the severity and number of side effects. Synthetic lethality (SL), a genetic interaction wherein two nonessential genes cause cell death when knocked out simultaneously, has been suggested as a method of identifying novel DCs. A combination of two drugs that mimic genetic knockout may cause cellular death through a synthetic lethal pathway. Because SL can be context-specific, it may be possible to find DCs that target SL pairs in tumours while leaving healthy cells unscathed. However, elucidating all synthetic lethal pairs in humans would take more than 200 million experiments in a single biological context – an unmanageably large search space. It is thus necessary to develop computational methods to predict human SL. In this thesis, we develop connectivity homology, a novel measure of network similarity that allows for the comparison of interspecies protein-protein interaction networks. We then use this principle to develop Species-INdependent TRAnslation (SINaTRA), an algorithm that allows us to predict SL between species using protein-protein interaction networks. We validate it by predicting SL in S. pombe from S. cerevisiae, then generate over 100 million SINaTRA scores for putative human SL pairs. We use these data to predict new areas of cancer combination therapy, and then test fifteen of these predictions across several cell lines. Finally, in order to better understand synergy, we develop DAVISS (Data-driven Assessment of Variability In Synergy Scores), a novel way to statistically evaluate the significance of a drug interaction.

This research work aimed to assess the Health-Related Quality of Life of women with breast and gynecological cancer undergoing adjuvant antineoplastic chemotherapy. A descriptive study with cross-sectional design and quantitative approach. The research took place at the chemotherapy ward of a nonprofit tertiary referral hospital for cancer surgery in Fortaleza-CE, Brazil. The study sample consisted of 72 women. Data collection happened from April to May 2012. After given informed consent, all women participated in individual interviews and completed the research protocol consisting of a questionnaire of socio-demographic data and the scale of the European Organization for Research and Treatment of Cancer: Quality of Life Evaluation in cancer patients (QLQ-C30 version 3.0). From the analytical study, we highlight the following results: most patients considered the overall QOL measure as âgreatâ with predominant scores 06 and 07. The sub-scale of the item for Social Functioning had the best score with 54.2. On the other hand, we observed the worst performances of women in the Role Performance, Emotional, Physical, and Cognitive Functioning. Regarding the most frequent or intense symptoms, the most reported were pain, fatigue, insomnia, and loss of appetite. At the opposite extreme were dyspnea, nausea and vomiting, with a mean score of 81.9 and 86.1, respectively. The item relating to Financial Difficulty represented a factor that negatively influences the Quality of Life with representation of 44.4 on the average score. Thus, we conclude that the interaction between clinical situation and treatments for the coexisting disease have cumulative and deleterious effects on Quality of Life, emphasizing the specific concerns related to cancer. It is worth mentioning that the predictive factors for Health-Related Quality of Life identified in this study should receive more attention in the health care practice, they may represent also starting points for future studies that address in depth the different aspects involving the QOL of cancer patients. / Este trabalho de investigaÃÃo teve como objetivo avaliar a Qualidade de Vida Relacionada à SaÃde de mulheres com cÃnceres de mama e ginecolÃgico submetidas à quimioterapia antineoplÃsica adjuvante. Estudo de natureza descritiva com delineamento transversal e abordagem quantitativa. O local da pesquisa foi o setor de quimioterapia de uma instituiÃÃo hospitalar filantrÃpica de nÃvel terciÃrio e referÃncia em cirurgia oncolÃgica na cidade de Fortaleza-Ce. A amostra do estudo foi composta por 72 mulheres. A coleta de dados foi realizada no perÃodo de abril a maio de 2012. ApÃs dado o consentimento informado, todas as mulheres participaram de uma entrevista individual e preencheram o protocolo de investigaÃÃo constituÃdo por um questionÃrio de dados sÃcio demogrÃficos e pela escala da European Organization for Research and Treatment of Cancer: AvaliaÃÃo da Qualidade de Vida do doente oncolÃgico (QLQ-C30 versÃo 3.0). Do estudo analÃtico realizado, destacam-se os seguintes resultados: A medida global de QV foi considerado pela maioria como âÃtimaâ com predomÃnio das notas 6 e 7. A sub-escala no item Funcionamento social obteve melhor escore com 54,2. Em contrapartida, os piores desempenhos das mulheres foram observados no nÃvel do Desempenho de PapÃis, Funcionamento Emocional, FÃsico e Cognitivo. Quanto aos sintomas mais frequentes ou intensos foram relatados a dor, fadiga, insÃnia e perda de apetite. No extremo oposto, estavam a dispnÃia, nÃuseas e vÃmitos, com um escore mÃdio de 81,9 e 86,1, respectivamente. O item referente à Dificuldade Financeira mostrou-se como fator que influencia negativamente na Qualidade de Vida com representaÃÃo de 44,4 na mÃdia de escore. Conclui-se que a interaÃÃo entre os quadros clÃnicos e os tratamentos da doenÃa coexistente tem efeitos cumulativos e deletÃrios sobre a Qualidade de Vida, acentuando as preocupaÃÃes especÃficas relacionadas ao cÃncer. Ressalta-se que os fatores preditivos de Qualidade de Vida Relacionada à SaÃde identificados neste estudo devem ser foco de maior atenÃÃo na prÃtica assistencial e podem representar pontos de partida para estudos futuros que abordem, em profundidade, os diferentes aspectos que envolvem a QV de pacientes com cÃncer.

Ce travail de thèse s’intègre dans la stratégie développée et brevetée par l’UMR 990 INSERM/UdA, qui consiste à exploiter l’affinité d’un vecteur ammonium quaternaire chargé positivement pour les protéoglycanes, afin d’acheminer des agents de diagnostic et/ou de thérapie, pour la prise en charge du chondrosarcome. Du fait de son abondante matrice extracellulaire de nature chondrogénique, de sa faible vascularisation et de son environnement hypoxique, le chondrosarcome est une tumeur chimio- et radio-résistante. Le seul traitement efficace à ce jour reste la chirurgie qui possède un taux de survie à 10 ans de seulement 21% en cas de rechute et dans les formes les plus graves. Dans ce contexte, une prodrogue cytotoxique activable en hypoxie dérivée du cyclophosphamide, de type nitroimidazole (8-QA) et possédant un ammonium quaternaire, a été développée et évaluée in vitro et in vivo, comparativement à son équivalent non « quaternisé » (8) et à un équivalent « quaternisé » mais non activable en hypoxie (10-QA). In vitro, les études par résonance plasmonique de surface (SPR) ont montré que les deux prodrogues « quaternisées », 8-QA et 10-QA possédaient une affinité plus importante pour l’agrécane que la prodrogue 8 ne possédant pas le vecteur ammonium quaternaire. Par la suite, nous avons développé un modèle de culture en 3 dimensions (sphéroïdes) des cellules de chondrosarcome humain HEMC-SS qui reproduit le microenvironnement hypoxique et riche en protéoglycanes retrouvé dans les tumeurs du cartilage in vivo. Les molécules activables en hypoxie 8-QA et 8 ont une activité cytotoxique supérieure en situation d’hypoxie qu’en normoxie, avec une résistance aux traitements augmentée pour le modèle de sphéroïde comparativement aux cellules cultivées en 2-D. In vivo, sur un modèle de xénogreffe de cellules de chondrosarcome humain HEMC-SS implantées sur des souris SCID, modèle préalablement caractérisé en terme d’hypoxie (imagerie photoacoustique, échographie de contraste, Doppler) et de protéoglycanes, la molécule 8-QA entraine (i) une inhibition significative de la croissance tumorale de 62,1%, alors que la molécule 8 et la molécule 10-QA n’ont aucune activité in vivo ; (ii) une diminution des effets indésirables, améliorant ainsi l’index thérapeutique. La caractérisation de l’activité antitumorale sur les tumeurs prélevées a mis en évidence une diminution de l’activité mitotique, une augmentation de l’apoptose (p53S15) et une diminution de la prolifération (PCNA) pour les échantillons traités avec la molécule 8-QA. De plus les études d’immunohistochimie ont montré que cette molécule entraine une augmentation des dommages à l’ADN (marquage γH2Ax) retrouvés majoritairement dans les régions hypoxiques (marquage au pimonidazole). La dernière partie de ce travail de thèse a consisté à optimiser, chez des souris NUDE, de nouveaux modèles in vivo de chondrosarcome humain exprimant à la fois un environnement hypoxique et une matrice extracellulaire riche en protéoglycanes pour affiner la caractérisation de l’activité anticancéreuse de la molécule 8-QA. Pour cela nous avons développé un modèle de xénogreffe de sphéroïdes HEMC-SS implantés en situation sous cutanée et un modèle orthotopique de cellules de chondrosarcome humain HEMC-SS implantées en position paratibiale. Après caractérisation, les premiers résultats d’efficacité antitumorale sur ces deux modèles ont confirmé une activité prometteuse de la molécule 8-QA. En conclusion, ces travaux de thèse auront permis de démontrer que l’exploitation des caractéristiques phénotypiques du chondrosarcome par une approche bi-spécifique est une stratégie prometteuse pour la prise en charge thérapeutique de cette pathologie, certes rare mais redoutable. Il a également contribué à montrer l’importance de l’interaction des cellules tumorales avec leur environnement pour la réponse aux traitements de chimiothérapie. / This work takes place in the strategy developed and patented by our lab UMR 990 INSERM/UdA, that exploits the affinity of positively charged quaternary ammonium to proteoglycans, in order to address diagnostic and/or therapeutic agents for chondrosarcoma management. Due to its abundant chondrogenic extracellular matrix, its poor vascularization and its hypoxic microenvironment, chondrosarcoma is chemo- and radio-resistant. The only effective treatment remains surgical resection that could be at the origin of a 10-years survival rate of 21% in case of local relapse of high-grade tumors. In this context, a quaternary ammonium-conjugated hypoxia-activable prodrug, 8-QA, has been developed and studied in vitro and in vivo respectively to its non-quaternary ammonium conjugated derivative, 8, and to a quaternary ammonium-conjugated non-hypoxia activable 10-QA. In vitro, surface plasmon resonance (SPR) studies evidenced that the two quaternary ammonium-conjugated derivatives, 8-QA and 10-QA, highlighted a higher affinity for aggrecan than non-quaternary ammonium conjugated prodrug 8. We have then developed a 3-D culture model (spheroid) of human chondrosarcoma HEMC-SS cell line that was demonstrated to reproduce the hypoxia and proteoglycan-rich microenvironment similar to in vivo cartilaginous neoplasms. Hypoxia-activated prodrugs, 8 and 8-QA, exhibited a higher cytotoxic activity in hypoxia as compared to normoxia, associated to an increased resistance for 3-D culture respectively to 2-D cells. In vivo, on human HEMC-SS xenograft model implanted on SCID mice and previously characterized in term of hypoxia (photoacoustic and contrast echographic imaging, Doppler), 8-QA derivative induced (i) a significant inhibition of tumor growth of 62,1% while 8 and 10- QA derivatives did not exhibit any antitumor activity; (ii) a decrease of side effects, both improving the therapeutic index. Mechanistic analysis on tumors sampled evidenced a decrease of mitotic activity and proliferation (PCNA), an increase of apoptosis (p53S15) for 8-QA treated tissues. Interestingly, immunohistochemistry studies highlighted that 8-QA caused DNA damages (evidenced by γH2Ax marker) which are mainly localized in hypoxic areas (pimonidazole staining). Finally, we optimized, on NUDE mice, new in vivo human chondrosarcoma models highly expressing simultaneously a hypoxic and proteoglycan-rich microenvironment in order to refine the characterization of 8-QA antitumor activity. For this, we developed a xenograft model of HEMC-SS spheroid implanted subcutaneously and an orthotopic model of HEMC- SS cells inoculated in paratibial location. After characterization, first results of antitumor efficacy on these two models confirmed the promising activity of 8-QA derivative. To conclude, this work demonstrates the proof of concept that exploiting the phenotypic features of chondrosarcoma by a bi-selective approach, is a promising innovative strategy for the therapeutic management of this pathology, relatively rare but redoubtable. This work also demonstrates the role of tumor cell interactions with their environment for tumor growth and response to chemotherapy treatments.

The purpose of this study was to determine how early seizure blockade with ethosuximide (ESX) would influence ion channel expression and long-term spike-wave discharge (SWD) activity in epileptic WAG/Rij rats. The goal was to elucidate the question Do seizures beget seizures? in a genetically prone model and if so, to attempt to interrupt this cycle by early intervention. In our first experiment, we used immunocytochemistry to determine the effect of ESX on cortical expression of ion channels in treated and untreated WAG/Rij rats and age-matched Wistar controls. This experiment revealed that treatment with ESX blocked the upregulation of Nav1.1 and Nav1.6 as well as the downregulation of HCN1 that is associated with epileptic activity in rats (p < .05). In a second experiment, WAG/Rij rats were divided into 3 groups: untreated (H2O), temporary early treatment (ESX 4 month), and continuous early treatment (ESX continuous), and SWD activity was measured by electroencephalogram (EEG) at various timepoints. This second experiment revealed that animals in the ESX 4 month group spent less percent time in SWD (0.242 ± .068 SEM) than animals in the H2O group (0.769 ± .060 SEM, p < .001), although they spent slightly more percent time in SWD than animals in the ESX continuous group (0.020 ± .065 SEM, p = .003). This effect was predominantly due to seizure number, and average seizure duration did not vary among the three groups. Additionally, power spectrum analysis revealed a significant correlation when the difference between power spectra for H2O and ESX 4 month rats was compared to the power spectrum of a seizure (Pearson correlation equals 0.955, 2-tailed significance < .000000001), suggesting quantitatively that seizures were reduced by temporary early treatment. This suggests that early prevention of SWD may reduce the burden of seizures later in life, and that possibilities for prevention of genetic absence epilepsy should be further investigated.

The use of the oral cavity membranes as sites of drug administration has been a topic of increasing interest for the past decade. The buccal route, in particular, offers several advantages over the per oral route and may prove to be a viable alternative to other routes for drug delivery, as it bypasses hepatic first pass metabolism, thereby improving the systemic bioavailability of the administered drug. A controlled drug release formulation may further enhance the therapeutic efficacy of a buccal drug delivery system. Propranolol HCI (PHCI), a non-selective p-blocker, primarily advocated in the treatment of hypertension, has a short half-life (3 - 6 hours) and is also subjected to extensive hepatic first-pass metabolism following oral administration, resulting in a low oral bioavailability, therefore rendering it an ideal candidate for buccal drug delivery. For optimal controlled release and mucoadhesivity of a buccal delivery system containing PHCI, the blending of polymers and drug of opposing solubilities may be required for the formation of monolayered films. The aim of this study was therefore to formulate and characterise multipolymeric monolayered mucoadhesive films containing drug and polymer/s of opposing solubilities for the buccal delivery of PHCI. First, preparation parameters for the formation of monolayered multipolymeric films (MMFs) and homopolymeric PHCI films comprising drug and polymer/s of opposing solubilities, i.e. Chitosan (CHT) and Poly(D,L-lactide-co-glycolide) (PLGA) by an emulsification/casting/solvent evaporation method were investigated. MMFs could be prepared at all homogenisation speeds (6000, 9000, 12000, 15000 rpm) and times (1, 5, 15, 25 minutes). The films showed micromatrices embedded in the film matrix due to the inclusion of the PLGA polymer. Increased homogenisation speed and time resulted in a reduction in the size of the micromatrices. Phase separation occurred at temperatures below 20 °C. Emulsifiers employed in the study (Poly(vinylalcohol) (PVA) and Tween 80®) adversely affected the morphology and appearance of the film and were therefore not considered feasible for inclusion in the formulation. The preparation parameters identified for emulsification without phase separation and the subsequent generation of monolayered films, without phase separation during solvent evaporation and drying, were emulsification at 20 °C and homogenisation at 9500 rpm for 15 minutes. It was discovered through preliminary investigations and a comprehensive literature search that the conventional film casting method of film preparation suffered from poor drug content uniformity. To address this problem of non-uniformity, a specially designed silicone-molded tray (SMT) for film casting was prepared and evaluated in terms of enhancing drug content uniformity. These investigations confirmed that the SMT with teflon-coated perspex inserts provided a reproducible method for the preparation of both homopolymeric and multipolymeric (including drug and polymers of similar and opposing solubilities) films that met drug content uniformity requirements (assay values were within 92-107.5%) and also reduced the variability in mucoadhesivity (p=0.2922), drug release [fi values = 92.76, 90.99 and 86.06) and film thickness for all three trays. The final phase of this study involved the identification of a suitable polymeric blend for the preparation of MMFs comprising hydrophilic and hydrophobic polymers for the controlled buccal delivery of PHCI and subsequent characterisation of these films in terms of their physicochemical/mechanical properties. Initial investigations of different polymers for the formation of homopolymeric films showed that the combination of drug and polymer/s of opposing ionic states was not possible due to complexation. PHCI film formation as homopolymeric films was achievable with hydrophilic polymers, Hydroxypropylmethylcellulose (HPMC) and CHT, and hydrophobic polymers, Ethylcellulose (EC) and Eudragit® RSI00 (EUD100). It was also found that combining PHCI, a hydrophilic drug, with a hydrophilic polymer (CHT or HPMC) failed to retard drug release (> 80% at 1 hour), whilst the release of PHCI from a homopolymeric film comprising a hydrophobic polymer (EC or EUD100) was retarded. A PHCIiEUDlOO (1:10) film provided controlled release but was too retarded (< 67% at 8 hours) for the purposes of this study. Hence, the polymeric content of the formulation was altered by the addition of a hydrophilic polymer CHT, to obtain the desired controlled release profile. A PHCI:EUD100:CHT (1:10:0.5) polymeric blend (MMF) was found to be suitable for the controlled release of PHCI and was reproducible in terms of drug content uniformity (p=0.1964), drug release [h values = 83.18; 82.03 and 71.19) and mucoadhesivity (p=0.9971). Drug release followed Higuchi's square-root model (r2=0.9426). Scanning electron microscopy revealed that the addition of CHT to the PHCI:EUD100 (1:10) film formulation rendered it more textured, which contributed to the faster drug release observed with the PHCI:EUD100:CHT (1:10:0.5) MMF. Swelling and erosion studies indicated that maximal swelling of the films occurred after 1 hour and 28.26% of the film eroded during the 8 hour test period. The system also demonstrated acceptable mucoadhesivity and mechanical properties. The surface pH of the films also remained constant at neutral pH throughout the study. The data obtained in this study confirmed the potential of this multipolymeric monolayered film system as a promising candidate for the controlled buccal delivery of PHCI. Key words: Films; Buccal; Multipolymeric; Mucoadhesive; Controlled drug release; Propranolol HCI / Thesis (M. Med. Sc.) - University of KwaZulu-Natal, 2007.

Sister chromatid exchange (SCE) and micronuclei (MN) were studied in peripheral human lymphocytes, treated in vivo with atenolol, azathioprine (AZA) and Chlorpropamide (CPA), and from patients on long term therapy with these drugs. The clinical study consisted of samples from 18 atenolol, 8 AZA and 9 CPA treated patients, and 35 age and sex matched controls. The CPA patients' controls were matched for disease (diabetes). Additional controls monitored variation between culture time. 20 metaphases were scored for SCEs and 2000 cells for MN per person. Statistical comparison of treated and untreated groups were with two-sample t-tests (SCE data) and 2x2 contingency χ² tests (MN data). There were two significant results. The atenolol treated had more MN (p< 0.01) and the AZA treated more SCEs (p< 0.02) than their control groups. The CPA treated and control groups did not differ. In the <i>in vitro</i> study concentrations used were, Atenolol 1.3, 2.7, 6.7 and 13.3ug/ml, AZA 5, 25, 50 and 100ug/ml and CPA and Diabinese (DIA) (pharmaceutical preparation of CPA) 250, 500 and 1000ug/ml. All culture lengths were 72 hours after mitotic stimulation (0 hours). Several exposure regions were used, they were: With metabolising enzymes (S9), all drugs for 6 hours at 48 hours. Without S9, Atenolol for 72 hours, AZA for 24 hours (at times - 24 hours and 48 hours), CPA and DIA for 24 hours at 48 hours. 20 metaphases were scored for SCEs and 4000 cells for MN. Dosed cultures were compared statistically with the control cultures using analyses of variance (SCE data) and linear regression analyses (MN). The significant results were; AZA, increases in SCEs in all experiments, increases in MN with S9 and without S9 (experiment b); CPA increase in MN with S9, decrease in MN without S9. No effects were found with atenolol or DIA treatment.

Bibliography: leaves 1-26. / xvi, [271] leaves : bill. (chiefly col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Develops a sensitive rat model of benzodiazepine tolerance and withdrawal using objective and continuous measures (activity, electromyographic activity and body temperature) recorded by radiotelemetry / Thesis (Ph.D.)--University of Adelaide, Dept. of Clinical and Experimental Pharmacology, 1998?