The present project investigated the effect of glucose, high dose insulin and normoglycemia (GIN) therapy in patients undergoing coronary revascularization surgery. A reduction in myocardial injury as measured by cardiac troponin I was the primary end point. Cardiac function based on hemodynamics and vasoactive drug requirements as well as clinical outcome were evaluated. Hormones and metabolites and cardiac metabolism were investigated concurrently as potential mechanisms of GIN therapy. The major findings of the present study are that GIN therapy reduced post-operative myocardial injury and myocardial dysfunction leading to a decrease in major complications following coronary artery bypass grafting surgery. The mechanism of the overall improvement in cardiac function and decreased morbidity following CABG with GIN therapy is likely to be multi-factorial, but from the present results, is influenced by improved myocardial metabolism. GIN therapy is thus an effective diet for the ischemic heart.

Sucralfate is a drug that effectively heals duodenal, gastric and oesophageal ulcers. It is not absorbed systemically and it has been shown to act locally by coating the ulcer base. However when it was also shown to prevent stress ulcers and ethanolinduced gastric mucosa! lesions, it seemed likely that it acted in some way to improve the effectiveness of the gastric mucosa! barrier. Some investigators suggested that it did so by stimulating local prostaglandin release. The Slomiany group, on the basis of in vitro work on the effects of Sucralfate on pig gastric mucus, claimed that Sucralfate acted by altering the physico-chemical properties of mucus to increase the viscosity and retard the back diffusion of H+ ions. The work described in this dissertation set out to verify, in vivo, these claimed effects on mucus, using an experimental porcine model of peptic ulceration, the bile duct ligated pig. In addition, the effects of Sucralfate were compared with those of Famotidine and Misoprostol, and changes in mucous prostaglandins, gastric juice pepsin and gastric flora were sought. By way of introduction, the known and postulated actions of Sucralfate, current understanding of gastric mucus physiology and pathogenesis of peptic ulceration, have been reviewed, as have experimental animal models of peptic ulceration, in order to justify using the bile duct ligated pig model.

No description available.

Dissertation (PhD)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: This thesis provides the first scientific evidence on the cancer modulating properties of two unique South African herbal teas, rooibos (Aspalathus Iinearis) and honeybush (Cyclopia intermedia) utilizing in vitro as well as in vivo carcinogenesis assays by: • Demonstrating the in vitro antimutagenic activity of aqueous extracts of the herbal teas against the metabolic activated mutagens, 2-acetylaminofluorene (2- AAF) and the mycotoxin, aflatoxin B1 (AFB,) as well as, to a certain extent, against the direct acting mutagen, hydrogen peroxide, utilizing the Salmonella typhimurium mutagenicity assay. • Increasing the activity of hepatic drug metabolizing enzymes, glutathione Stransferase alpha and UPD-glucuronosyl transferase, and reduced the oxidative stress by stabilizing the level of reduced glutathione (GSH) resulting in an increased hepatic reduced to oxidized glutathione ratio (GSG:GSSG). No toxic effects were noticed in rats consuming the herbal teas for 10 weeks as their sole source of drinking fluid. • Demonstrating the ex vivo modulation of 2-AAF- and AFB1-induced mutagenesis by sub- cellular hepatic fractions of rats consuming the herbal teas in the Salmonella mutagenicity assay. Hepatic cytosolic fractions protected against mutagenesis of both mutagens, while the microsomal fractions exhibited a reduced capacity to metabolize AFB1 to its active mutagenic metabolite. • Providing evidence for the in vivo modulation of tumour promotion using the liver as well as the two-stage skin carcinogenesis animal models. The unprocessed herbal teas arrested proliferation of the placental form of glutathione-Stransferase (GSTP+) altered cells as well as reduced the total number of enzyme altered foci in the liver of rats. Topical application of polyphenolic fractions of the various herbal teas prior to 12-0-tetra-decanoylphorbol-13-acetate (TPA) tumour promotion, reduced tumour formation in mouse skin initiated with 7,12-dimethylbenz[ ajanthracene (DMBA). The protective effect was illustrated by a decreased tumour incidence, a reduction in tumour volume as well as a delayed onset of tumour development. The f1avanol/proanthocyanidin content of the fractions could playa major role in the protection against skin tumour promotion. • Proposing possible mechanisms whereby rooibos and honeybush herbal teas could exert their cancer modulating properties with respect to in vitro and ex vivo antimutagenicity, in vivo oxidative status and reduced tumour promotion. • Providing evidence that the herbal teas mimic the cancer modulating properties of green and black teas although differences exist, presumably due to differences in the polyphenolic constituents. • Suggesting that rooibos and honeybush herbal teas may play an important role as chemopreventive agents in the modulation of cancer. / AFRIKAANSE OPSOMMING: Hierdie tesis bevat die eerste ondersoek na die effek van waterige en polifenoliese ekstrakte van rooibos (Aspalathus Iinearis) en heuningbos (Cyclopia intermedia) op verskeie aspekte van kankerontwikkeling. Die twee kruietees is uniek aan Suid-Afrika en kan 'n belangrike rol speel in die voorkoming van kanker. Verskillende in vitro so wei as in vivo studies het die volgende getoon: • Antimutageniese aktiwiteite teen die metabolies-geaktiveerde mutagene, 2- asetielaminofluoreen (2-AAF) en die mikotoksien, aflatoksien B1 (AFB1) in die Salmonella fyphimurium mutagenisiteitstoets. 'n Beperkte mate van beskerming is ook verleen teen die oksidatiewe mutageen, waterstofperoksied, sonder metaboliese aktivering. • Verhoogde aktiwiteite van die fase II ensieme, glutatioon S-tranferase alfa en UDP-glukuronidase, wat liggaamsvreemde verbindings metaboliseer. Die kruietees verlaag die oksidasietoestand soos weerspieel word deur 'n toename van gereduseerde glutatioon tot die geoksideerde vorm in die lewer van rotte wat 10 weke hierdie kruietees gedrink he!. Die kruietees het geen toksiese uitwerking op die rotte gehad nie. • Antimutageniese aktiwiteite van subselluiE~re fraksies van die lewer teenoor 2- AAF en AFB1 in die Salmonella toets. Die sitosolfraksie van die rotlewer bied beskerming teen die ge"induseerde mutagenese van beide mutagene, terwyl die mikrosomale fraksie ook die metaboliese aktivering van AFB1 na die aktiewe mutageniese metaboliet verminder. • In vivo modulering van kankerpromosie met behulp van bekende rotlewer en muisvel kankerontwikkelingsmodelle. In die lewermodel het die ongeprosesseerde kruietees beide die ontwikkeling en getal van GSTP+ fokusse onderskeidelik vertraag en verminder. In die geval van die velkankermodel het aanwending van polifenoliese fraksies van die kruietees beskerming gebied teen die ontwikkeling van velkankers by muise. Die aantal en grootte van die tumors het afgeneem terwyl die verskyning daarvan ook vertraag is. • Verskeie meganismes waardeur rooibos- en heuningboslee moonllik kanker kan moduleer word voorgeslel. Verskille in die polifenoliese sameslelling asook hul onderskeie konsenlrasies kan 'n belangrike rol speel in die kankerveranderende effekle van die lees. • Oal gereelde inname van rooibos- en/of heuningboslee moonllik 'n belangrike rol kan speel in die voorkoming van dieel- en omgewings-geYnduseerde kankers.

Alzhemier's disease (AD) is a common form of dementia which is characterized by the deposition of amyloids in affected neurons and a cholinergic neurotransmission deficit in the brain. Current therapeutic intervention for AD is primarily based on inhibition of brain acetylcholinesterase (AChE) to restore the brain acetylcholine level. Cryptotanshinone (CT) is a diterprene which is extracted from the root of Salvia miltiorrhiza, an herb that is commonly prescribed in Chinese medicine to treat cardiovascular disease. The present study is aimed at verifying CT's property as an AChE inhibitor using different models. By AChE activity assay, CT was found to be a dual inhibitor which inhibits both human acetylcholinesterase (AChE) and butylcholinesterase (BuChE) with similar IC50. CT inhibited human AChE in a reversible manner, and the inhibition showed the characteristics of mixed-type. To human BuChE, CT is an uncompetitive inhibitor. CT can also inhibit AChE from rat cortical neurons. Apart from AChE inhibition, CT was demonstrated to have ameliorating effect on glutamate excitotoxicity, which is a cause of neuron death in AD. Further study showing that CT treatment can reduce cellular tau phosphorylation, which is the downstream effector of glutamate-induced excitotoxicity. In animal model, the effect of CT on learning impairment in scopolamine-treated rats was also evaluated by the acquisition protocol of Morris water maze. The task learning ability of scopolamine-treated rats was significantly reversed by CT, and the CT-fed rats were able to develop spatial searching strategy comparable to the control animals. Chronic administration of CT at effective doses did not cause significant hepatotoxicity. Cholinergic side effect of muscle weakness was not observed in CT treated rats. On the contrary CT was found to increase the locomotor activity of NIH mice in forced swimming test through reducing the lactic acid in the circulation. Data in this study gives further support on CT's potential as a therapeutic drug for treating AD. / by Wong, Kin Kwan Kelvin. / Source: Dissertation Abstracts International, Volume: 73-01, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 144-167). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Finally, the neuroprotective effects of TGP against corticosterone-induced neurotoxicity in rat pheochromocytoma (PC12) cells, an in vitro experimental model of depression were studied. The results showed TGP treatment dose-dependently protected the cells against corticosterone-induced toxicity. The cytoprotection afforded by TGP treatment was shown to be associated with an enhanced antioxidant activity, and increased expressions of neurotrophins including brain-derived neurotrophic factor, nerve growth factor and neurotrophin-3. / Secondly, the antidepressant-like effect of TGP was evaluated by a rat model of depression induced by chronic unpredictable mild stress (CUMS). The results showed that a 5-week CUMS caused depression-like behavior in rats, as indicated by a significant decreases in sucrose consumption (assessed by sucrose preference test) and locomotor activity (assessed by open-field test), and an increase in immobility time (assessed by forced swim test). Intragastric administration of TGP during the five weeks of CUMS procedure significantly suppressed these behavioral changes induced by CUMS. / Taken together, the results confirmed the antidepressant-like effect of TGP. The antidepressive action of TGP may be mediated by the modulation of the hypothalamic-pituitary-adrenal axis function, the inhibition of oxidative stress, and the up-regulation of neurotrophins, thereby leading to the neuroprotective effects. / The antidepressant-like effect of TGP was firstly evaluated by the behavioral despair test, forced swim test and tail suspension test. The results showed that intragastric administration of TGP caused a significant reduction of immobility time in both forced swim and tail suspension tests in mice. TGP treatment also significantly reduced the duration of immobility time in the forced swim test in rats. / The root of Paeonia lactiflora Pall. (Family: Ranunculaceae), commonly known as peony, is a component herb of many traditional formulae for the treatment of depression-like disorders. Previous studies have demonstrated the antidepressive effect of peony extract in mouse models of depression. Total glycosides of peony (TGP) is regarded as the major active ingredients of peony. The present study aims to confirm the antidepressive potential of TGP and evaluate its action mechanisms. / Thirdly, the neuroprotective effects of TGP on CUMS-treated rats and its possible mechanisms were investigated. The results showed that treatment with TGP for 5 weeks produced neuroprotective effects on the hippocampus of CUMS-treated rats. This effect was associated with the attenuation of hypothalamic-pituitary-adrenal axis hyperactivation (characterized by a decreased serum corticosterone level and an increased hippocampal glucocorticoid receptor expression), an inhibition of oxidative stress, and up-regulation of neurotrophins such as brain-derived neurotrophic factor and neurotrophin-3 in the hippocampus. / Mao, Qingqiu. / Adviser: Che Chun-Tao. / Source: Dissertation Abstracts International, Volume: 73-01, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 158-186). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

This review summarizes the principles of cancer chemoprevention and discusses the evidence from epidemiologic and experimental studies and preclinical and clinical trials of potential colorectal chemopreventive agents. The putative mechanisms of action of the drugs in chemoprevention and their potential to reduce the incidence and mortality rate of colorectal neoplasms are discussed. The future of colorectal chemoprevention will depend on important new insights into molecular carcinogenesis of colorectal cancer, application of molecular markers as surrogate endpoints, and ultimately on therapeutic targets of prevention in clinical trials.

Baicalein is known to be a potent antifungal agent and induces programmed cell death in Candida albicans. In the present study, we found that baicalein also inhibited the growth of C. krusei isolates. The minimal inhibitory concentrations of baicalein against eight C. krusei isolates were 1.35--2.70 microg/ml. One-hour exposure to baicalein elicited a consistent and moderate post-antifungal effect on the C. krusei isolates. Further flow cytometric study demonstrated a depolarization of mitochondrial membrane potential. However, both the levels of reactive oxygen species and DNA fragmentation were not significantly changed after baicalein treatment in C. krusei. It can be concluded that the antifungal activity of baicalein was mitochondria-dependent in both C. krusei and C. albicans, but the antifungal mechanism was different. Reactive oxygen species may not play a direct role and baicalein does not initiate programmed cell death or apoptosis in C. krusei. The structure-activity relationship study showed that the three hydroxyl groups in baicalein were essential for its antifungal potency. / Candidiasis has become a serious infection with very high mortality and morbidity in the world if not providing effective treatments. However, due to clinical limitation and resistance of the current antifungal agents, there is an urgent need to search for novel antifungals. In this study, after screening a compound library (n=400) for antifungal activity, three members (metergoline, purpurin and baicalein) were chosen for further study. Their antifungal characteristics and the antifungal mechanisms were investigated. / Metergoline, a serotonin receptor antagonist, was found to have potent antifungal activity against the intrinsically fluconazole-resistant human fungal pathogen Candida krusei. The minimal inhibitory concentration and minimal fungicidal concentration of metergoline against C. krusei were 4 microg/ml and 8 microg/ml respectively. Metergoline induced post-antifungal effect. Significant synergism was found in combination of metergoline with amphotericin B by a checkerboard assay, which may be due to the perturbation of cell permeability and increase in the intracellular accumulation of antifungal agents. Metergoline also inhibited extracellular phospholipase production in C. krusei. To gain insights into the mechanisms, intracellular changes that accompany apoptosis were examined by flow cytometry and spectrophotometry. The results showed an increase in the level of reactive oxygen species, depolarization of mitochondrial membrane potential, phosphatidylserine externalization, and positive terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labelling in the metergoline-treated C. krusei . Taken together, we conclude that metergoline may promote apoptosis in C. krusei through reactive oxygen species production and perturbation in mitochondrial homeostasis, implying its antifungal potential to treat candidiasis. / The antifungal activity of purpurin, a natural red anthraquinone pigment in madder root (Rubia tinctorum L.), was evaluated against Candida isolates by a broth microdilution assay. The minimal inhibitory concentrations of purpurin against Candida species isolates were 1.28--5.12 microg/ml. Mechanistic studies indicated that purpurin inhibited energy-dependent efflux pumps of Candida isolates. Furthermore, purpurin demonstrated a depolarization of mitochondrial membrane potential, suggesting a possible linkage of the antifungal mechanism of purpurin to Candida apoptosis. / Kang, Kai. / Adviser: Fong Wing Ping. / Source: Dissertation Abstracts International, Volume: 73-02, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 98-123). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

TRAIL has been widely investigated as an anti-cancer agent due to its high efficacy in vitro and its safety to normal cells. However, TRAIL-based agents only showed modest effect in clinical studies because of TRAIL resistance. In addition to apoptosis, TRAIL has also been reported to promote pro-survival signalings, cell migration and metastasis. One of the current strategies in the development of TRAIL-based therapeutics focuses on the search of sensitizing agents that help overcome TRAIL resistance without increasing harm to normal cells. / This study reports a novel combination of TRAIL and 4-methylumbelliferone (4-MU) which can kill HeLa cells and HepG2 cells synergistically without cytotoxicity to Hs68 non-tumorigenic cells. This combination also effectively inhibited cancer cell proliferation and potentiated apoptosis by accumulation of tBid, down-regulation of anti-apoptotic proteins and inhibition of Akt. More importantly, 4-MU could suppress the recovery of HeLa cells from TRAIL-induced apoptosis, a process previously implicated to be associated with cancer relapse and tumor heterogeneity. This study has provided solid evidences substantiating further research on TRAIL-4-MU combination. / 腫瘤壞死因子相關凋亡誘導配體 (TRAIL) 在體外實驗中有良好抗癌作用，且不會傷害正常細胞，使之得到廣泛研究，成為近年熱門的新抗癌分子。然而TRAIL 在臨床實驗中並沒有顯著抗癌功效，一般認為人體腫瘤細胞對TRAIL 具有耐藥性。研究文獻亦指出，除了細胞凋亡外，TRAIL亦會誘發細胞存活機制、促進細胞移行及癌細胞轉移。目前，對於TRAIL相關藥品抗癌作用的研究有幾個大方向，其中之一就是尋找良好的增敏分子。良好的增敏分子應能夠增力癌細胞對TRAIL的敏感性，對抗癌細胞對TRAIL的耐藥性，同時不能殺傷正常細胞。 / 本研究揭示了一個全新的抗癌藥物聯合。當TRAIL聯合4-甲基伞形酮(4-MU)能產生協同作用，殺傷HeLa癌細胞和HepG2癌細胞而不會傷害Hs68正常細胞。此組合能有效抑制癌細胞生長，並透過增加tBid蛋白表達、減少抗凋亡蛋白表達及抑制Akt來促進細胞凋亡。更為重要的是，4-MU能抑制HeLa癌細胞自TRAIL誘導凋亡的恢復和逆轉。而癌細胞凋亡逆轉一般被視為與癌症復發及腫瘤多樣性有關。本研究提供了實質證據，支持對TRAIL-4-MU組合的後續研究。 / Wu, Hoi Yan. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2015. / Includes bibliographical references (leaves 90-107). / Abstracts also in Chinese. / Title from PDF title page (viewed on 05, October, 2016). / Detailed summary in vernacular field only. / Detailed summary in vernacular field only.

Yang, Yaling. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 187-207). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts also in Chinese.