Zou Wei. / Thesis submitted in: December 2001. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 98-119). / Abstracts in English and Chinese. / Declaration --- p.i / Acknowledgements --- p.ii / Publication lists --- p.iii / Abstract --- p.ix / Abbreviations --- p.xiii / List of tables and figures --- p.xiv / Chapter Chapter 1: --- General Introduction --- p.1 / Chapter 1.1. --- Endothelium-dependent relaxation in coronary and pulmonary circulation --- p.1 / Chapter 1.1.1. --- Endothelium-derived relaxing factors --- p.2 / Chapter 1.1.1.1. --- Nitric Oxide --- p.3 / Chapter 1.1.1.2. --- PGI2 --- p.5 / Chapter 1.1.1.3. --- EDHF --- p.6 / Chapter 1.1.2. --- EDHF in coronary and pulmonary circulation --- p.8 / Chapter 1.1.2.1. --- EDHF in coronary circulation --- p.8 / Chapter 1.1.2.2. --- EDHF in pulmonary circulation --- p.9 / Chapter 1.2. --- Effect of hyperkalemia on EDHF-mediated relaxation --- p.10 / Chapter 1.3. --- Organ Preservation Solutions --- p.13 / Chapter 1.3.1. --- Euro-Collins solution --- p.14 / Chapter 1.3.2. --- University of Wisconsin solution --- p.15 / Chapter Chapter 2: --- Objectives and research approaches --- p.16 / Chapter 2.1. --- Objectives --- p.16 / Chapter 2.1.1. --- "Endothelium-dependent relaxation resistant to INDO, L-NNA, and HbO in porcine and pulmonary coronary micro-arteries" --- p.16 / Chapter 2.1.2. --- "EET11,12 and EDHF-mediated function in porcine coronary micro-arteries" --- p.17 / Chapter 2.1.3. --- "Comparison of EC or UW solution on endothelium-dependent relaxation resistant to INDO, l-NNA, and HbO in porcine pulmonary arteries" --- p.17 / Chapter 2.2. --- Research approaches --- p.18 / Chapter 2.2.1. --- "Endothelium-dependence of the relaxation by BK or EET11,12" --- p.18 / Chapter 2.2.2. --- Effect of hypothermic storage with EC and UW solution on EDHF-related relaxation --- p.18 / Chapter 2.2.3. --- Time-dependent alteration of endothelium-dependent relaxation in pulmonary micro-arteries by EC and UW solution --- p.19 / Chapter 2.2.4. --- Effect of HbO in endothelium-dependent relaxation --- p.19 / Chapter Chapter 3: --- Material and Methods --- p.21 / Chapter 3.1. --- General Methods --- p.21 / Chapter 3.1.1. --- Porcine heart and lung collection and transportion / Chapter 3.1.2. --- Myograph --- p.21 / Chapter 3.1.3. --- Myosight --- p.24 / Chapter 3.1.4. --- Anatomizing blood vessel --- p.24 / Chapter 3.1.5. --- Mounting --- p.24 / Chapter 3.1.6 --- Normalization --- p.26 / Chapter 3.1.6.1. --- Normalization of coronary micro-artery --- p.27 / Chapter 3.1.6.2. --- Normalization of pulmonary micro-artery --- p.28 / Chapter 3.1.7. --- Precontraction --- p.30 / Chapter 3.1.8. --- Endothelium-dependent relaxation --- p.31 / Chapter 3.2. --- Coronary artery studies --- p.32 / Chapter 3.2.1. --- Porcine heart harvest and anatomy --- p.32 / Chapter 3.2.2. --- Characteristic of histology of porcine coronary micro-artery --- p.32 / Chapter 3.3. --- Pulmonary artery studies --- p.35 / Chapter 3.3.1. --- Porcine lung harvest and anatomy --- p.35 / Chapter 3.3.2. --- Characteristic of histology of porcine pulmonary micro- artery --- p.36 / Chapter 3.4. --- Drugs --- p.41 / Chapter 3.4.1. --- Drugs --- p.41 / Chapter 3.4.2. --- Preparation of oxyhemoglobin solution --- p.41 / Chapter 3.5. --- Statistical Analysis --- p.42 / Chapter 3.5.1. --- Calculation of EC50 --- p.42 / Chapter 3.5.2. --- Statistical analysis --- p.42 / Chapter Chapter 4: --- "Epoxyeicosatrienoic Acids (EET11,12) May Partially Restore EDHF-Mediated Function in Coronary Micro-Arteries" --- p.43 / Chapter 4.1. --- Abstract --- p.43 / Chapter 4.2. --- Introduction --- p.44 / Chapter 4.3. --- Experimental Protocol --- p.45 / Chapter 4.3.1. --- Precontraction --- p.45 / Chapter 4.3.2. --- "EDHF-mediated (INDO, L-NNA, and HbO-resistant) relaxation" --- p.45 / Chapter 4.3.3. --- "EET11,12-mediated relaxation after exposure to hyperkalemia" --- p.46 / Chapter 4.3.4. --- "The effect of incubation with EET11,12 on the BK-induced, EDHF-mediated relaxation" --- p.46 / Chapter 4.4. --- Results --- p.47 / Chapter 4.4.1. --- Resting force --- p.47 / Chapter 4.4.2. --- HbO and U46619-induced contraction force --- p.48 / Chapter 4.4.3. --- "EET11,12-induced relaxation in coronary micro-arteries after exposure to hyperkalemia" --- p.49 / Chapter 4.4.4. --- "The EDHF-mediated relaxation to BK resistant to INDO, l- NNA,and HbO" --- p.51 / Chapter 4.4.4.1. --- Incubated in either hyperkalemic solution (K+ 20mmol/L) or Krebs' solution (control) --- p.51 / Chapter 4.4.4.2. --- "Incubated in either hyperkalemic solution (K+ 20mmol/L) plus EET11,12 or Krebs' solution (control)" --- p.53 / Chapter 4.5. --- Discussion --- p.57 / Chapter 4.5.1. --- EDHF plays an important role in the coronary micro-arteries --- p.57 / Chapter 4.5.2. --- "EDHF-mediated (INDO, l-NNA, and HbO-resistant) relaxation in the coronary micro-arteries" --- p.58 / Chapter 4.5.3. --- "EET11,12 may partially mimic the EDHF-mediated relaxation in the porcine coronary micro-artery" --- p.59 / Chapter 4.5.4. --- "Effect of EET11,12 added in hyperkalemia may partially restore the EDHF-mediated relaxation in the porcine coronary micro-arteries" --- p.59 / Chapter Chapter 5: --- Impaired EDHF-Mediated Relaxationin Porcine Pulmonary Micro-arteries by Cold Store with Euro-Collin's and University of Wisconsin Solution --- p.61 / Chapter 5.1. --- Abstract --- p.61 / Chapter 5.2. --- Introduction --- p.62 / Chapter 5.3. --- Experimental Protocol --- p.64 / Chapter 5.3.1. --- Precontraction --- p.64 / Chapter 5.3.2. --- "Role of EDHF-mediated (INDO, L-NNA and HbO-resistant) relaxation in porcine pulmonary micro-arteries by BK orA23187" --- p.64 / Chapter 5.3.3. --- Effect of hyperkalemia or preservation solutions (EC or UW) on the EDHF-mediated relaxation by BK or A23187 --- p.65 / Chapter 5.3.3.1. --- The effect of hyperkalemia --- p.65 / Chapter 5.3.3.2. --- Effect of EC solution on the EDHF-mediated relaxation --- p.65 / Chapter 5.3.3.3. --- Effect of UW solution on the EDHF-mediated relaxation --- p.66 / Chapter 5.3.3.4. --- The effect of UW and EC solutions on the contractility of the pulmonary micro-artery --- p.66 / Chapter 5.4. --- Results --- p.66 / Chapter 5.4.1. --- Resting force --- p.66 / Chapter 5.4.2. --- U46619-induced contraction force --- p.67 / Chapter 5.4.3. --- Role of EDHF-mediated relaxation induced by BK or A23187 --- p.67 / Chapter 5.4.4. --- The effect of hyperkalemia --- p.71 / Chapter 5.4.5. --- Effect of EC solution on the EDHF-mediated relaxation --- p.72 / Chapter 5.4.6. --- Effect of UW solution on the EDHF-mediated relaxation --- p.73 / Chapter 5.4.7. --- The effect of UW and EC solution on the contractility of the pulmonary micro-artery --- p.73 / Chapter 5.5. --- Discussion --- p.77 / Chapter 5.5.1. --- EDHF-mediated endothelial function exists in the pulmonary micro-circulation --- p.77 / Chapter 5.5.2. --- Hyperkalemia exposure reduces EDHF-related relaxation and possible mechanism --- p.78 / Chapter 5.5.3. --- The effect of EC and UW solutions on the EDHF-media relaxation in the pulmonary micro-arteries --- p.79 / Chapter Chapter 6: --- General Discussion --- p.82 / Chapter 6.1. --- Endothelium-dependent vasodilators: BK and A23187 --- p.82 / Chapter 6.2. --- EDHF in porcine coronary and pulmonary micro-arteries --- p.84 / Chapter 6.2.1. --- EDHF in porcine coronary micro-arteries --- p.84 / Chapter 6.2.2. --- EDHF in porcine pulmonary micro-arteries --- p.87 / Chapter 6.2.3. --- Vascular stretch and release of endothelium-derived vasodilators --- p.87 / Chapter 6.2.4. --- "EET11,12" --- p.88 / Chapter 6.3. --- "Endothelium-dependent relaxation resistant to INDO, L- NNA, and HbO in porcine coronary and pulmonary microcirculation" --- p.89 / Chapter 6.4. --- "Alteration of endothelium-dependent relaxation resistant to INDO, l-NNA, and HbO after exposure to hyperkalemia" --- p.90 / Chapter 6.5. --- "Alteration of endothelium-dependent contraction resistant to INDO, L-NNA, and HbO after exposure to EC or UW solutions" --- p.91 / Chapter 6.6. --- Clinical implications --- p.92 / Chapter 6.7. --- Limitations --- p.93 / Chapter 6.7.1. --- Common limitations --- p.93 / Chapter 6.7.2. --- Limitation of in vitro study --- p.93 / Chapter 6.8. --- Future work --- p.94 / Chapter Chapter 7: --- Conclusion --- p.96 / References --- p.98 / Appendies / "Wei Zou, Qin Yang, Anthony PC Yim, & Guo-Wei He Epoxyeicosatrienoic acids (EET11,12) may partially restore endothelium- derived hyperpolarizing factor-mediated function in coronary micro- arteries. Annals of Thoracic Surgery. 2001; 72(12): 1970~1976."

First study determined the effects of genetic deletion of nNOS on the levels of spontaneous apoptosis in brain of young-adult (2-3 months) and aged (12-18 months) mice, using nNOS-knockout mice with age-matched B6129SF2/J mice as wild-type control. The results indicate that aging resulted in 11-fold increase in levels of apoptotic-DNA-fragmentation in B6129SF2/J mouse brain. nNOS-knockout mice demonstrated dramatic (72-fold) increases in levels of apoptotic-DNA-fragmentation in young-adult, but not aged, brains. Aging resulted in decreased number of nNOS-positive cells, increased number of iNOS-positive cells and no change of eNOS-positive cells in control mice. The data suggest that nNOS may serve an anti-apoptotic/neuroprotective role in young-adult mouse brain. However, because of diminished nNOS and increased iNOS with aging, this neuroprotective effect may become less effective in aged mice. / Fourth study showed that new microchip-electrophoresis-technology can be successfully used to identify and quantify levels of apoptosic-DNA-fragments in brain slice cultures, similar to our previous studies with CE-LIF. Because of the much greater throughput of microchip-electrophoresis-system, compared to CE-LIF, this new technology should help accelerate the progress of apoptosis research. / In second study, apoptotic effects of genetic deletion of either eNOS or iNOS were studied using young-adult (1-4 months) and aged (12-24 months) eNOS- or iNOS-knockout mice with age-matched C57BL/6J wild-type control mice. The data show that both young-adult and aged iNOS-knockout mice had dramatically (8- to 36-fold) higher levels of apoptotic-DNA-fragmentation compared to control, especially noticeable in hippocampus and medulla oblongata. Both young-adult and aged eNOS-knockout mice also had dramatically (18- to 35-fold) higher levels of apoptotic-DNA-fragmentation compared to control, especially in cerebral cortex, hippocampus and medulla oblongata. The data suggest that both iNOS and eNOS provide neuroprotective effects, helping to limit the extent of spontaneous apoptosis in brain of young-adult and aged mice. / Nitric oxide (NO) has either pro-apoptotic or anti-apoptotic effects on neuronal cells, depending on concentration of NO produced by different source of NO synthases (NOSs) including neuronal-NO-synthase (nNOS/NOS-1), inducible-NO-synthase (iNOS/NOS-2) or endothelial-NO-synthase (eNOS/NOS-3) and possibly age of the individual. The present study determines if genetic deletion of nNOS, iNOS or eNOS alters levels of aging-induced apoptosis in vivo and hydrogen peroxide (H2O2)-induced-apoptosis in organotypic brain slice cultures using NOS-knockout mice. The quantitative ultrasensitive techniques using capillary-electrophoresis with laser-induced-fluorescent detector (CE-LIF) and Cell-Death---Detection-ELISA were used as novel ways to accurately measure the levels of apoptotic-DNA-fragmentation. Expressions of different forms of NOSs were determined by immunohistochemical-staining. / Third study determined H2O2-induced apoptosis in hippocampal and cerebellar slices from young-adult (8-10 weeks) and aged (12-24 months) C57BL/6J control mice, as well as iNOS- and eNOS-knockout mice (determined by Cell-Death-Detection-ELISA measuring levels of apoptotic-DNA-fragmentation). The data show spontaneous onset of apoptosis occurred in both hippocampal and cerebellar slices during culturing, beginning at 24 hours and progressively increasing for 48--72 hours. Staurosporine (positive-control) and H2 O2 both caused time-dependent increases in apoptosis in both hippocampal and cerebellar slices, compared to time-matched controls. Lastly, genetic deletion of iNOS greatly reduced levels of spontaneous apoptosis in young hippocampus and aged cerebellum, suggesting iNOS had contributed to induction of spontaneous apoptosis. / Chow Wing Han Vivian. / "Dec 2005." / Advisers: Siew Boon Chew Cheng; Ray Ronald Fiscus. / Source: Dissertation Abstracts International, Volume: 67-11, Section: B, page: 6218. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 144-153). / 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, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

Abstract not available

No description available.

In the past decades, tumors have progressively been perceived as highly integrated systems in which the genetically unstable tumor cells and the genetically stable host cells cooperate to promote tumor growth. This view suggests that, beside tumor cells (that are targeted by conventional anticancer treatments such as radio- and chemotherapy), host cells within the tumor microenvironment can be targeted by antitumor therapy. Such alternative strategies are strongly supported by the need to overcome several limitations of the conventional therapies targeting tumor cells, such as collateral toxicity due to lack of tumor selectivity, limited tumor accessibility, and the selection of treatment-resistant variants. By contrast to tumor cells, the genetically stable host cells should not develop resistance to treatments. In this context, the observation that tumor growth is fundamentally dependent on the onset of a private tumor neovasculature (tumor angiogenesis) has revolutionized the field of cancer research. Several treatments have been developed aimed to prevent tumor angiogenesis (anti-angiogenic strategies) or to erase the existent tumor vasculature (anti-vascular approaches) supporting the survival and growth of thousands of tumor cells. However, although such therapies achieved cancer cure in animal models, they turned out to be rather inefficient when tested in patients. This can be attributed to differences in the angiogenic status between fast-growing animal tumors and slow-growing human tumors at the time of clinical detection. Another reading of the above-mentioned observations is that anticancer treatments could benefit from interventions aimed at increasing their efficiency. For instance, radiotherapy could benefit from tumor reoxygenation while a decrease in tumor interstitial pressure could facilitate tumor accessibility to circulating agents. In this context, the mature vasculature is an attractive target since it controls tumor blood supply and is highly accessible for therapy. Therefore, strategies aimed at exploiting its functional reactivity by inducing vasorelaxation have the potential to improve tumor perfusion/drug delivery and oxygenation/radiosensitivity. To be exploited in the clinics, such pro-vascular approaches have to fulfill essential requirements. First, they need to achieve high selectivity for tumor vessels. It should prevent systemic toxicity as well as the stealing of the blood flow towards the peripheral vasculature. Second, vasodilation has to be transient, so that the tumor should not take advantage of an increased energetic supply to grow faster. Third, the therapeutic effects have to be achieved in several tumor types and in different host strains to gain a wide therapeutic range of applicability. Finally, vasomodulation has to be achieved with interventions relevant to the clinical situation, ensuring direct therapeutic significance. However, the therapeutic exploitation of agents modulating tumor perfusion was generally hampered by confounding effects on the systemic blood pressure. In our studies, we have documented that this lack of tumor selectivity can be overcome by identifying vasomodulatory pathways that are selectively altered within the tumor microenvironment, allowing selective vasomodulatory interventions. According to the criteria detailed above, to identify a differential tumor vascular reactivity, we had to work with mice models of mature tumor vascularization. We reasoned that preexisting host arterioles in mice, if coopted, should retain architectural characteristics (such as a muscular coat) necessary for functional reactivity but also be influenced by the tumor microenvironment at both molecular and functional levels. To gain in reproducibility, this model was developed by injecting syngeneic tumor cells in the vicinity of the saphenous arteriole (i.e., a collateral branch of the femoral artery) in the rear leg of mice. With tumor growth, this arteriole was progressively included in the tumor cortex (coopted), with side branches running deeply into tumors. This model was developed using several tumors and mice strains. It provides the unique advantage to allow the easy identification and isolation of mature tumor vessels from fast-growing animal tumors. To evaluate differential vasoreactivity in those tumor-coopted vessels, we adapted pressure myography, a device initially dedicated to the study of the reactivity of coronary arterioles (see annex 1). In our hands, the unprecedented application of pressure myography to the study of small tumor vessels proved to be very efficient. Indeed, this technique not only served us to confirm that arterioles remain sensitive to vasomodulation under tumor cooption, but also allowed us to evidence two major adaptations of host vessels to the tumor microenvironment: the acquisition of an ET-1-mediated basal constrictive tone and a defect in the vasodilatory NO pathway. Furthermore, we used pressure myography to identify and characterize vasomodulatory strategies exploiting these differential reactivities. More particularly, we showed that both BQ123 (an ETA inhibitor) and ionizing radiations (that restored a functional NO pathway) promoted the vasodilation of the tumor-coopted vessels. In vivo, we verified that these strategies fulfilled the essential requirements of pro-vascular approaches: tumor selectivity, transient effects, broad range of applicability, and therapeutic significance in clinically relevant regimens. This latter study led us to further explore the effects of radiotherapy on the status of the tumor vasculature. Hence, we showed that fractionated radiotherapy induced tumor angiogenesis, thereby providing a rationale to combine radiotherapy to anti-angiogenic therapies.

No description available.

Mevinphos (Mev) is an organophosphate insecticide that acts on the rostral ventrolateral medulla (RVLM), the origin of sympathetic vasomotor tone, to induce cardiovascular responses. This study investigated the role of Trk (tropomyosin-related kinase) (receptor form) or Src (non-receptor form) tyrosine kinase at the RVLM in Mev-induced cardiovascular responses. Bilateral microinjection of Mev (10 nmol) into the RVLM elicited two distinct phases of cardiovascular responses, designated Phase I (sympathoexcitatory) and Phase II (sympathoinhibitory) Mev intoxication. Western blot assay showed that whereas p-Trk490 was increased during Phase I, p-Src416 was increased only during Phase II Mev intoxication. Interestingly, application of a Trk specific inhibitor (K252a; 1 pmol) or Src specific inhibitor (SU6656; 100 pmol) into the bilateral RVLM blunted the Mev-elicited sympathoexcitatory or sympathoinhibitory effect, respectively. Besides, K252a was limited to block NOS I protein expression in the RVLM during Mev intoxication, SU6656 only inhibited NOS II protein expression in the RVLM during Mev intoxication. We conclude that Trk tyrosine kinase (p-Trk490) in the RVLM participates in the Phase I cardiovascular responses during Mev intoxication, Src tyrosine kinase (p-Src416) in the RVLM participates in the Phase II cardiovascular responses associated with Mev intoxication.

Thesis (Ph. D.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains xiv, 180 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references.

Thesis (Ph. D.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains xii, 195 p. : ill. Vita. Includes abstract. Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 118-135).