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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

In vitro and in vivo mechanistic studies of the wound-healing effects of Astragali Radix and phytochemical analysis of its active fractions/components isolated using bioassay-guided fractionation. / CUHK electronic theses & dissertations collection

January 2013 (has links)
Lai, Kwok Kin. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 229-251). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
12

The in vivo and in vitro investigations of Astragali Radix and Rehmanniae Radix formula in diabetic wound healing and its mechanisms of actions. / CUHK electronic theses & dissertations collection

January 2013 (has links)
Tam, Chor Wing Jacqueline. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 322-359). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
13

Induction of LTB4 12-hydroxydehydrogenase (LTB4DH) by Radix Astragali and Radix Paeoniae Rubra: a study of theactive compounds and related biological functions

Wei, Lai, 魏来 January 2009 (has links)
published_or_final_version / Chinese Medicine / Master / Master of Philosophy
14

Investigation of the role of GRP78 and the potential therapeutic use of radix astragali in diabetic complications

Wong, Daniella Pui Kwan 01 January 2013 (has links)
No description available.
15

The mitogenic effect of radix ophiopogonis and radix astragali on neonatal primary rat cardiomyocytes and differentiated H9C2 cardiac cells.

January 2003 (has links)
Law Sui-Lin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 99-109). / Abstracts in English and Chinese. / CONTENTS --- p.i / ABSTRACT --- p.v / 撮要 --- p.vii / ACKNOWLEDGEMENTS --- p.ix / LIST OF FIGURES & TABLES --- p.xi / ABBREVIATIONS --- p.xv / Chapter Chapter 1 --- INTRODUCTION --- p.1 / Chapter 1.1 --- The Transition of Hyperplastic to Hypertrophic Growth During Heart Development --- p.1 / Chapter 1.2 --- The Controversial Capability of Heart Regeneration --- p.3 / Chapter 1.3 --- Challenges in Treating Heart Diseases --- p.5 / Chapter 1.4 --- A New Insight Behind Traditional Chinese Medicine (TCM) for Treating Heart Diseases --- p.7 / Chapter 1.5 --- The Potential Mitogenic TCMs on Cardiomyocytes --- p.10 / Chapter 1.5.1 --- Radix Astragali --- p.11 / Chapter 1.5.2 --- Radix Ophiopogonis --- p.12 / Chapter Chapter 2 --- MATERIALS & METHODS --- p.14 / Chapter 2.1 --- Materials --- p.14 / Chapter 2.2 --- Cell Culture --- p.16 / Chapter 2.2.1 --- Primary neonatal rat cardiomyocytes cell culture --- p.16 / Chapter 2.2.1.1 --- Mayer's hemalum-eosin staining --- p.17 / Chapter 2.2.2 --- Primary rat fibroblasts cell culture --- p.18 / Chapter 2.2.3 --- H9C2 cardiac cell culture --- p.18 / Chapter 2.3 --- TCMs Preparation and Treatment --- p.19 / Chapter 2.3.1 --- Preparation of TCMs powder from aqueous extracts --- p.19 / Chapter 2.3.2 --- Preparation of culture medium with TCMs powder --- p.19 / Chapter 2.3.3 --- Pre-treatment of undifferentiated and differentiated H9C2 cardiac cells with TCMs --- p.20 / Chapter 2.3.4 --- Post-treatment of differentiated H9C2 cardiac cells with TCMs --- p.20 / Chapter 2.4 --- Assessment of DNA Synthesis and Proliferation --- p.21 / Chapter 2.4.1 --- Tritiated thymidine incorporation assay --- p.21 / Chapter 2.4.2 --- 5-Bromo-2'-deoxy-uridine (BrdU) assay --- p.22 / Chapter 2.4.3 --- Cell counting --- p.23 / Chapter 2.4.4 --- Statistical analysis --- p.23 / Chapter 2.5 --- Screening of Differentially Expressed Genes in H9C2 Cells after TCM Treatment by cDNA Microarray --- p.25 / Chapter 2.5.1 --- Total RNA extraction --- p.25 / Chapter 2.5.2 --- RNA labeling --- p.26 / Chapter 2.5.2.1 --- Synthesis of fluorescence labeled probe --- p.26 / Chapter 2.5.2.2 --- Purification of fluorescence labeled probe --- p.27 / Chapter 2.5.3 --- Microarray hybridization --- p.28 / Chapter 2.5.3.1 --- Concentration of fluorescence labeled probe --- p.28 / Chapter 2.5.3.2 --- Hybridization --- p.28 / Chapter 2.5.3.3 --- Post-hybridization treatment --- p.29 / Chapter 2.5.4 --- Data collection --- p.29 / Chapter 2.5.4.1 --- Scanning of slide --- p.29 / Chapter 2.5.4.2 --- Image processing: spots finding and quantification --- p.30 / Chapter 2.5.5 --- Data normalization and analysis --- p.30 / Chapter 2.6 --- Confirmation of Differentially Expressed Genes in H9C2 Cells after TCM Treatment by RT-PCR --- p.32 / Chapter 2.6.1 --- DNase I digestion of total RNA sample --- p.32 / Chapter 2.6.2 --- First-strand cDNA synthesis --- p.32 / Chapter 2.6.3 --- RT-PCR of the candidate genes --- p.33 / Chapter Chapter 3 --- RESULTS --- p.36 / Chapter 3.1 --- Neonatal Primary Rat Cardiomyocytes --- p.36 / Chapter 3.1.1 --- Preparation of high-purity neonatal primary rat cardiomyocytes --- p.36 / Chapter 3.1.2 --- Neonatal primary rat cardiomyocytes ceased to undergo DNA replication after 6-day in vitro culturing --- p.38 / Chapter 3.1.3 --- Both MD and HQ promoted the growth of day 1 primary rat cardiomyocytes in dose- and time-dependent manners --- p.40 / Chapter 3.1.4 --- HQ is more potent than MD in promoting the growth of day 7 primary rat cardiomyocytes --- p.43 / Chapter 3.2 --- H9C2 Cardiac cells --- p.45 / Chapter 3.2.1 --- Proliferative effect of MD and HQ on undifferentiated H9C2 cardiac cells --- p.45 / Chapter 3.2.2 --- Pre-treatment of HQ on H9C2 cardiac cells during differentiation --- p.50 / Chapter 3.2.3 --- Pre-treatment of MD and HQ on differentiated H9C2 cardiac cells --- p.52 / Chapter 3.2.4 --- Post-treatment of MD on differentiated H9C2 cardiac cells…… --- p.55 / Chapter 3.3 --- Primary Rat Fibroblasts --- p.57 / Chapter 3.3.1 --- Proliferative effect of MD and HQ on primary rat fibroblasts --- p.58 / Chapter 3.4 --- Screening of Differentially Expressed Genes in H9C2 Cells after HQ Treatment by cDNA Microarray --- p.60 / Chapter 3.4.1 --- Differentially expressed genes in undifferentiated H9C2 cardiac cells after HQ treatment --- p.60 / Chapter 3.4.2 --- Differentially expressed genes in differentiated H9C2 cardiac cells after HQ treatment --- p.66 / Chapter 3.4.3 --- Comparison of differentially expressed genes in both undifferentiated and differentiated H9C2 cardiac cells after HQ treatment --- p.72 / Chapter 3.5 --- Confirmation of Differentially Expressed Genes in H9C2 Cells after HQ Treatment by RT-PCR --- p.73 / Chapter 3.5.1 --- "Preferential up-regulation of N-G, N-G-dimethylarginine dimethylaminohydrolase mRNA expression level in undifferentiated H9C2 cardiac cells after HQ treatment " --- p.74 / Chapter 3.5.2 --- Preferential up-regulation of heme oxygenase-3 mRNA expression level in undifferentiated H9C2 cardiac cells after HQ treatment --- p.75 / Chapter 3.5.3 --- Preferential up-regulation of cyclin B mRNA expression level in differentiated H9C2 cardiac cells after HQ treatment --- p.76 / Chapter Chapter 4 --- DISCUSSION --- p.77 / Chapter 4.1 --- HQ Being a More Effective Mitogenic TCM than MD on Cardiomyocytes Exerted its Effect in Dose- and Time Dependent --- p.79 / Chapter 4.2 --- Mitogenic Effect of Both MD and HQ might Possibly Due to the Regulation of Intrinsic Factors --- p.82 / Chapter 4.3 --- HQ Rather Than MD Showed a Higher Specificity in Promoting DNA Synthesis in Cardiomyocytes --- p.83 / Chapter 4.4 --- The Differentially Expressed Genes were Supported by The Clinical Functions of HQ --- p.85 / Chapter 4.5 --- Relating the Differentially Expressed Genes with Cardiac Growth and Development --- p.87 / Chapter 4.6 --- The Hypothetic Mechanisms of Action that HQ Exerted on Cardiac Growth and Development --- p.92 / Chapter 4.7 --- Future Prospect --- p.94 / Chapter 4.7.1 --- In vivo study of HQ on the proliferation of rat cardiomyocytes from neonatal to postnatal development --- p.94 / Chapter 4.7.2 --- The study of transgenic mice carrying the target gene regulated by HQ on cardiac growth and development --- p.96 / Chapter 4.7.3 --- The determination of active component of HQ on cardiac growth and development --- p.97 / REFERENCES --- p.99 / APPENDIX --- p.110
16

Medicinal Herbs and the Kidney: Unresolved Issues

Kenneth Wojcikowski Unknown Date (has links)
In the exploration into new therapeutic agents for human disease, medicinal herbs offer an enormous resource due to their wide range of biologically active components. However, because of these biologically active components, medicinal herbs can also have toxic side effects. The focus of this thesis is the effect of herbal therapies, both good and bad, on chronic kidney disease (CKD) and tubulointerstitial fibrosis. Tubulointerstitial fibrosis is considered one of the defining characteristics of CKD. In Chapter 1, the literature regarding the pathogenesis of tubulointerstitial fibrosis is reviewed, beginning with the mechanisms of its development, the main structural and functional features, and the molecular mediators. The structural features include activation of resident fibroblasts and transition of tubular epithelial cells into myofibroblasts, deposition of extracellular matrix proteins, increased apoptosis of normal cells of the renal nephron and development of tubular atrophy, increased renal oxidative stress, and hypoxia of renal tissues. Molecular mediators that are explored include angiotensin II, transforming growth factor-ß1 and numerous other cytokines and growth factors. Pharmacological manipulation of these features and their molecular mediators for regression of tubulointerstitial fibrosis is then discussed. Currently, the gold standard of therapy for people with CKD is blockade of the renin-angiotensin-aldosterone system with angiotensin converting enzyme inhibitors (ACEIs) and/or angiotensin receptor blockers (ARBs). Because of the complexity of the pathogenesis of renal fibrosis and the multiple mechanisms by which ACEIs and ARBs work, this portion of the thesis focuses on the qualities that additional agents should have to complement their actions. These additional agents could work by decreasing oxidative damage, by decreasing fibroblast numbers through apoptosis, through the interruption of inflammatory, fibrotic mediators, by increasing anti-inflammatory mediators or through other mechanisms. The literature review therefore continues with a discussion of the historical use of medicinal herbs in genitourinary pathologies and the known contributions that medicinal herbs can make to the treatment or development of tubulointerstitial fibrosis and CKD. From this review, a large number of herbs were identified as having traditional use in renal disorders or as being of interest, currently, to researchers of renal pathologies. However, much information is lacking regarding the mechanisms by which the hypothesised benefits occur, making it impossible to assess which herb(s) may offer valuable additive support or alternative treatments to the therapies currently given to people with CKD. Furthermore, there is a lack of information regarding toxicity of these herbs; many herbs have never been assessed in cell culture or in animal toxicity studies. It was apparent that preliminary in vitro work was necessary before in vivo pharmacological work could be undertaken. This thesis, therefore, aimed to test the following hypotheses: (1) That medicinal herbs used currently for treatment of renal dysfunction have high anti-oxidant properties that can be further enhanced by specific extraction processes; (2) That the in vitro testing of selected extracts from medicinal herbs, identified in (1), will reveal some anti-oxidant benefits or indications of toxicity that need careful analysis in animal studies; (3) That careful in vivo testing of specific toxic medicinal herbs identified in these leadup studies will define specific pathological processes that predict an outcome of CKD; and (4) That careful in vivo testing of selected medicinal herbs, used in conjunction with more conventional medicines for CKD, will show an additive benefit when used to ameliorate development of CKD induced using an established animal model. The subsequent laboratory work was designed to test the validity of these hypotheses and the results are then presented in Chapters that each comprise a publication. The aim of Chapter 2 was to present a systematic analysis of the oxidant properties of 55 medicinal herbs that have been used traditionally to treat kidney and urinary disorders or have been of recent interest to researchers of renal disorders. Since different extraction processes yield different constituents, each of the herbs was sequentially extracted with three solvents of decreasing polarity. An assay was performed on each of the fractions to determine the oxygen radical absorbance capacity. The aim of Chapter 3 was to test the benefit or otherwise of each of the three extracts of the chosen herbs using an in vitro cell study. Each extract was tested for potential toxic, apoptotic, mutagenic and antioxidant activity on normal mammalian renal tubular epithelial cells (NRK-52E). The effect of the extracts on renal fibroblasts (NRK-49F) was also analysed. Several specific hypotheses arose from the combination of the systematic analyses and the literature review regarding benefits and toxicities of a number of the extracts. The subsequent in vivo work was designed to test the validity of two of these hypotheses. The aim of Chapter 4 was to test the hypotheses developed from the results of the previous Chapter. The herb Dioscorea villosa had demonstrated extreme cytotoxicity to mammalian renal epithelial cells and had caused transdifferentiation of epithelial cells into fibroblasts. An in vivo rodent model was used to test chronic dosage with this herb and its toxicity and predisposition for induction of CKD verified. The aim of Chapter 5 was to determine whether a herbal preparation (Angelica sinensis and Astragalus membranaceus) that had some support from the literature and the results from Chapters 2 and 3, could complement the actions of ACEIs in a rodent model of renal fibrosis (unilateral ureteral obstruction). The combination of herbal medicines and the ACEI was significantly more effective than the ACEI alone in ameliorating several characteristics of CKD development. To conclude the thesis, Chapter 6 provides an overview discussion of the results and a critical analysis of the methods used. Further, Chapter 6 looks towards future experiments that are planned to further resolve issues of concern about effects on renal health from use of medicinal herbs. .
17

Exploration of the anticancer mechanisms of novel chemotherapeutic adjuvants involving autophagy and immune system reprogramming in the treatment of pancreatic cancer

Zhang, Zhu 11 June 2020 (has links)
Pancreatic cancer is known to be one of the most life-threatening cancers characterized by aggressive local invasion and distant metastasis. The high basal level of autophagy in pancreatic cancer may be responsible for the low chemotherapeutic drug response rate and poor disease prognosis. However, the clinical application of autophagy inhibitors was unsatisfactory due to their toxicity and minimal single-agent anticancer efficacy. Hence, oncologists begin to consider the tumor microenvironment when exploring new drug targets. In the present study, the anti-tumorigenic mechanisms of two major phytochemicals derived from Chinese medicinal herbs had been investigated against pancreatic cancer development. Calycosin is a bioactive isoflavonoid of the medicinal plant Astragalus membranaceus. Our results have shown that calycosin inhibited the growth of various pancreatic cancer cells both in vitro and in vivo by inducing cell cycle arrest and apoptosis. Alternatively, calycosin also facilitated MIA PaCa-2 pancreatic cancer cell migration in vitro and increased the expression of epithelial-mesenchymal transition (EMT) biomarkers in vivo. Further mechanistic study suggests that induction of the Raf/MEK/ERK pathway and facilitated polarization of M2 tumor-associated macrophage in the tumor microenvironment both contribute to the pro-metastatic potential of calycosin in pancreatic cancer. These events appear to be associated with calycosin-evoked activation of TGF-β signaling, which may explain the paradoxical drug actions due to the dual roles of TGF-β as both tumor suppressor and tumor promoter in pancreatic cancer development under different conditions. Isoliquiritigenin (ISL) is a chalcone obtained from the medicinal plant Glycyrrhiza glabra, which can be a precursor for chemical conversion to form calycosin. Results have shown that ISL decreased the growth and EMT of pancreatic cancer cells in vitro, probably due to modulation of autophagy. ISL-induced inhibition of autophagy subsequently promoted reactive oxygen species (ROS) production, leading to induction of apoptosis in pancreatic cancer cells. Such phenomenon also contributed to the synergistic growth-inhibitory effect in combined treatment with the orthodox chemotherapeutic drug 5-fluorouracil. In addition, ISL-induced tumor growth inhibition in vivo was further demonstrated in a tumor xenograft mice model of pancreatic cancer. ISL promoted apoptosis and inhibited autophagy in the tumor tissues. Study on immune cells indicates that ISL could reduce the number of myeloid-derived suppressor cells (MDSCs) both in tumor tissue and in peripheral blood, while CD4+ and CD8+ T cells were increased correspondingly. In vitro test has revealed that ISL inhibited the polarization of M2 macrophage along with its inhibition of autophagy in M2 macrophage. These immunomodulating effects of ISL had reversed the pro-invasive role of M2 macrophage in pancreatic cancer.In conclusion, calycosin acts as a "double-edged sword" on the growth and metastasis of pancreatic cancer, which may be related to the dual roles of TGF-β and its influence on the tumor microenvironment. Alternatively, ISL consistently inhibited the growth and metastatic drive of pancreatic cancer through regulation of autophagy and reprogramming of the immune system. The differential modes of action of these compounds have provided new insights in the development of effective pancreatic cancer treatment adjuvants.

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