Pancreatic cancer kills over 1700 people each year in Australia. In 2000, there were 1908 new cases diagnosed and it remains one of the least treatable malignancies. In the USA, it was the fourth leading cause of cancer death in 2004, with 31,860 new cases and 31,270 recorded deaths. Photodynamic therapy (PDT) is a novel, potentially useful treatment for locally advanced pancreatic cancer with only limited research and clinical work addressing this until now. PDT induces non-thermal, cytotoxic and ischaemic injury to a targeted volume of tissue. During PDT, a photosensitizer is activated by non-thermal light in the presence of oxygen, generating cytotoxic oxygen species and inducing cellular injury and microvascular occlusion. The aim of this thesis was to conduct an animal safety study using two second generation photosensitizers, talaporfin sodium and verteporfin, to assess the risks of pancreatic PDT by looking at injury to organs adjacent to the pancreas and assessing recovery from PDT treatment of the pancreas. The Syrian Golden hamster animal model was used to compare the results of this research to previous work by other authors. The study design incorporated a number of additional experiments, including quantitative tissue fluorescence techniques, plasma level analysis and histopathology techniques. The methods for the animal safety study were similar to the approach used in the clinical setting and provided vital data on the likely risks and side effects of phototherapy in humans. The first study, looking at talaporfin sodium, found likely risks of duodenal injury, gastric injury and death with a limited effect on normal pancreas at photosensitizer doses likely to be employed for pancreatic cancer PDT. The second study, using verteporfin, found similar results with a more potent effect on the normal pancreas at studied drug doses. Both agents had short drug-light intervals, ranging from 15 minutes to 2 hours, reducing the need for pre-treatment hospitalization and short photosensitivity periods of about one to two weeks. Some animals suffered minor cutaneous photosensitivity injuries. A human pancreatic cancer PDT pilot study is feasible and the risks and complications should be acceptable.

Pancreatic cancer kills over 1700 people each year in Australia. In 2000, there were 1908 new cases diagnosed and it remains one of the least treatable malignancies. In the USA, it was the fourth leading cause of cancer death in 2004, with 31,860 new cases and 31,270 recorded deaths. Photodynamic therapy (PDT) is a novel, potentially useful treatment for locally advanced pancreatic cancer with only limited research and clinical work addressing this until now. PDT induces non-thermal, cytotoxic and ischaemic injury to a targeted volume of tissue. During PDT, a photosensitizer is activated by non-thermal light in the presence of oxygen, generating cytotoxic oxygen species and inducing cellular injury and microvascular occlusion. The aim of this thesis was to conduct an animal safety study using two second generation photosensitizers, talaporfin sodium and verteporfin, to assess the risks of pancreatic PDT by looking at injury to organs adjacent to the pancreas and assessing recovery from PDT treatment of the pancreas. The Syrian Golden hamster animal model was used to compare the results of this research to previous work by other authors. The study design incorporated a number of additional experiments, including quantitative tissue fluorescence techniques, plasma level analysis and histopathology techniques. The methods for the animal safety study were similar to the approach used in the clinical setting and provided vital data on the likely risks and side effects of phototherapy in humans. The first study, looking at talaporfin sodium, found likely risks of duodenal injury, gastric injury and death with a limited effect on normal pancreas at photosensitizer doses likely to be employed for pancreatic cancer PDT. The second study, using verteporfin, found similar results with a more potent effect on the normal pancreas at studied drug doses. Both agents had short drug-light intervals, ranging from 15 minutes to 2 hours, reducing the need for pre-treatment hospitalization and short photosensitivity periods of about one to two weeks. Some animals suffered minor cutaneous photosensitivity injuries. A human pancreatic cancer PDT pilot study is feasible and the risks and complications should be acceptable.

No description available.

Tests on hamsters reveal that there is a decided protective index from the soluble antigen prepared by the acid-heat extraction of living cultures of Leptospira pomona. They also reveal that the antigen must be given in quantities sufficiently small to be amenable to the system of the test animal or a condition of ”immunogenic paralysis“ results. Due to the number of hamsters in any one group whose pooled sera was tested, a fair evaluation could not be made between various groups in the agglutination-lysis test. Tests on the stability of the immunogenic agent used show that it is completely stable for at least a period of three months when stored in a refrigerator at 5 °C. / Master of Science

Fossorial mammals are frequently exposed to hypercapnic and/or hypoxic conditions in their burrows. This research compares ventilatory responses of golden hamsters (<i>Mesocricetus auratus</i>) to different ambient respiratory gas concentrations with those of the white rat (<i>Rattus norvegicus</i>). Total body plethysmography was used to measure tidal volume (V_T), respiratory frequency (R_f), and minute volume (V_E). The respiratory gases had carbon dioxide concentrations ranging from 0 to 790 and oxygen content ranging from 13 to 21%. Both hypercapnic and hypoxic gas mixtures caused hyperventilation in hamsters. The more a gas mixture deviated from normal air, the greater the ventilatory increase. Combining hypercapnic and hypoxic conditions did not potentiate the response. Rats exhibited a greater hyperventilation in response to hypercapnic-hypoxic and hypercapnic gas mixtures than did the hamsters. Hypoxia alone caused a greater response in the hamsters. Greater blood buffering capacity of hamsters offers a possible explanation for the different ventilatory responses observed between these two rodents. / M.S.

No description available.

Grape seed proanthocyanidins (GSP) as a cholesterol-lowering nutraceutical has been investigated in both humans and animals, however, little is known of how it interacts with the genes and proteins involved in lipoprotein metabolism in vivo. So the first objective of the present study was to investigate the effect of GSP supplementation on blood cholesterol level and gene expression of cholesterol-regulating enzymes in Golden Syrian hamsters maintained on a 0.1% cholesterol diet. / Hypercholesterolemia is one of the major proven risk factors for atherosclerosis. Decreasing blood total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels with cholesterol-lowering nutraceuticals and dietary intake modification could slow or reverse the progression of cardiovascular disease. / In conclusion, the present study confirmed that hypocholesterolemic activity of GSP was most likely mediated by enhancement of bile acid excretion and up-regulation of CYP7A1. The present study also demonstrated that frequent cholesterol and myristic acid intake is associated with elevation of plasma TC level, while beta-sitosterol intake frequency had no effect on plasma cholesterol for a given amount. / In the beta-sitosterol consumption frequency study, hamsters fed the basal diet with a gavage-administration of 3 mg cholesterol 3 times (control), or a gavage-administration of 3 mg beta-sitosterol with 3 mg cholesterol 3 times per day (high beta-sitosterol intake frequency), or a gavage-administration of 9 mg beta-sitosterol with 3 mg cholesterol for one time and 3 mg cholesterol for the other two times (low beta-sitosterol intake frequency). The results demonstrated that for a given dose of beta-sitosterol, the administration frequency had no or little effect on plasma lipoprotein profiles. The present study also found that cholesterol-lowering activity of beta-sitosterol was mediated by its inhibition on the intestinal cholesterol absorption with up-regulation of NPC1L1, ATP binding cassette transporters G5 and G8 (ABCG5/8) and MTP. / In the cholesterol consumption frequency study, hamsters were given daily 9 mg of cholesterol either in diet (high cholesterol intake frequency) or a gavage-administration of 3 times 3 mg (regular cholesterol intake frequency) and 1 time 9 mg (low cholesterol intake frequency). The results demonstrated that there was an increasing trend in concentrations of plasma TC, Non-HDL-C, TC/HDL-C ratio and TG in association with the cholesterol intake frequency. It is the first time to demonstrate that the increasing cholesterol intake frequency increased the apparent cholesterol absorption. Elevation of plasma TC and cholesterol absorption is most likely mediated by up-regulation of intestinal Niemann-Pick C1-like 1 (NPC1L1), acyl coenzyme A: cholesterol acyltransferase 2 (ACAT2), and microsomal triacylglycerol transport protein (MTP) gene expression. / In the myristic acid consumption frequency study, hamsters were given daily 210 mg of myristic acid either in diet (high myristic acid intake frequency) or a gavage-administration of 3 times 70 mg (regular myristic acid intake frequency) and 1 time 210 mg (low myristic acid intake frequency). The results showed that the increasing consumption frequency elevated plasma TC, Non-HDL-C and HDL-C levels. Elevation of plasma TC and HDL-C is most likely mediated by up-regulation of NPC1L1 and down-regulation of scavenger receptor BI (SR-BI) gene expression via enhancement of dietary myristic acid absorption. / The results affirmed supplementation of 0.5% or 1.0% GSP could decrease plasma TC, non-high density lipoprotein cholesterol (Non-HDL-C) and triglyceride (TG) levels. In addition, dietary GSP was able to increase the excretion of bile acids by 3--4 folds, this was partially mediated by up-regulation of Cholesterol 7 alpha-hydroxylase (CYP7A1) in both transcriptional and translational levels. It was concluded that the hypocholesterolemic activity of GSP was most likely mediated by enhancement of bile acid excretion and up-regulation of CYP7A1. / The second objective of the present study was to investigate the effect of cholesterol, myristic acid and beta-sitosterol consumption frequency on plasma lipoprotein profiles in hamsters. Numerous studies reported that dietary cholesterol and saturated fatty acids elevated plasma TC level, whereas dietary phytosterols in moderate and high doses favorably reduced plasma TC and LDL levels. However, it is still unknown whether consumption frequency of sterols and fatty acids could affect plasma cholesterol level and lipid profiles. / Jiao, Rui. / Adviser: Chen Zhen Yu. / Source: Dissertation Abstracts International, Volume: 73-02, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 123-150). / 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.

Ma, Ka Ying. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 113-129). / Abstracts in English and Chinese. / ACKNOWLEDGMENTS --- p.I / ABSTRACT --- p.II / LIST OF ABBREVIATIONS --- p.VII / TABLE OF CONTENTS --- p.IX / Chapter Chapter 1 --- General Introduction --- p.1 / Chapter 1.1 --- Calcium --- p.1 / Chapter 1.1.1 --- Recommendation of calcium intake --- p.1 / Chapter 1.1.2 --- Calcium toxicity --- p.2 / Chapter 1.1.3 --- Calcium homeostasis --- p.2 / Chapter 1.1.3.1 --- Role of parathyroid hormone in calcium homeostasis --- p.4 / Chapter 1.1.3.2 --- "Role of 1,25-dihydroxyvitamin D3 in calcium homeostasis" --- p.4 / Chapter 1.1.3.3 --- Role of calcitonin in calcium homeostasis --- p.6 / Chapter 1.2 --- Magnesium --- p.7 / Chapter 1.2.1 --- Recommendation of magnesium intake --- p.7 / Chapter 1.2.2 --- Absorption and secretion of magnesium --- p.8 / Chapter 1.3 --- Cholesterol --- p.9 / Chapter 1.3.1 --- Cholesterol homeostasis --- p.11 / Chapter 1.3.1.1 --- Role of LDLR --- p.14 / Chapter 1.3.1.2 --- Role of SREBP-2 --- p.17 / Chapter 1.3.1.3 --- HMGR as rate limiting step for cholesterol synthesis --- p.19 / Chapter 1.3.1.4 --- CYP7A1 as a key factor in production of bile acids --- p.21 / Chapter 1.3.1.5 --- Role of LXR in production of bile acids --- p.22 / Chapter 1.3.1.6 --- AC AT regulates cholesterol uptake in intestine --- p.22 / Chapter Chapter 2 --- Effect of Calcium Deficiency and Inadequacy on Blood Cholesterol Level in Intact Male and Castrated Hamsters --- p.25 / Chapter 2.1 --- Introduction --- p.25 / Chapter 2.2 --- Objective --- p.28 / Chapter 2.3 --- Materials and methods --- p.29 / Chapter 2.3.1 --- Hamsters --- p.29 / Chapter 2.3.1.1 --- Intact male hamster --- p.29 / Chapter 2.3.1.2 --- Castrated hamster --- p.30 / Chapter 2.3.2 --- Diets --- p.31 / Chapter 2.3.3 --- Determination of calcium content in animal diet --- p.33 / Chapter 2.3.4 --- "Determination of serum lipid, lipoproteins and calcium concentration" --- p.33 / Chapter 2.3.5 --- Determination of cholesterol concentration in organs --- p.34 / Chapter 2.3.6 --- Determination of fecal neutral and acidic sterols --- p.37 / Chapter 2.3.7 --- Determination of fecal neutral sterols --- p.37 / Chapter 2.3.8 --- Determination of fecal acidic sterols --- p.40 / Chapter 2.3.9 --- Statistics --- p.42 / Chapter 2.4 --- Results on intact male hamsters --- p.43 / Chapter 2.4.1 --- Diet composition --- p.43 / Chapter 2.4.2 --- Growth and food intake --- p.43 / Chapter 2.4.3 --- Organ weights --- p.43 / Chapter 2.4.4 --- Effect of calcium deficiency diet on the plasma lipid profile and calcium concentration of hamsters --- p.43 / Chapter 2.4.5 --- Effect of calcium deficiency diet on hepatic cholesterol of hamsters --- p.44 / Chapter 2.4.6 --- Effect of calcium on fecal neutral sterol output --- p.48 / Chapter 2.4.7 --- Effect of calcium on fecal acidic sterol output --- p.48 / Chapter 2.5 --- Results on castrated hamsters --- p.50 / Chapter 2.5.1 --- Growth and food intake --- p.50 / Chapter 2.5.2 --- Organ weights --- p.50 / Chapter 2.5.3 --- Effect of calcium deficiency diet on the plasma lipid profile and calcium concentration of hamsters --- p.50 / Chapter 2.5.4 --- Hepatic cholesterol --- p.50 / Chapter 2.5.5 --- Effect of calcium on fecal neutral sterol output --- p.53 / Chapter 2.5.6 --- Effect of calcium on fecal acidic sterol output --- p.53 / Chapter 2.6 --- Discussion --- p.55 / Chapter Chapter 3 --- Effect of Calcium Deficiency and Inadequacy on Blood Cholesterol Level in Intact Female and Ovariectomized Hamsters --- p.57 / Chapter 3.1 --- Introduction --- p.57 / Chapter 3.2 --- Objective --- p.58 / Chapter 3.3 --- Materials and methods --- p.59 / Chapter 3.3.1 --- Hamsters --- p.59 / Chapter 3.3.1.1 --- Intact female hamster --- p.59 / Chapter 3.3.1.2 --- Ovariectomized hamster --- p.60 / Chapter 3.3.2 --- Diets --- p.60 / Chapter 3.3.3 --- "Determination of serum lipid, lipoproteins and calcium concentration" --- p.60 / Chapter 3.3.4 --- "Determination of cholesterol concentration in organs, fecal neutral and acidic sterols" --- p.60 / Chapter 3.3.5 --- "Western blottting of liver SREBP-2, LDLR, HMGR, LXR and CYP7A1 proteins" --- p.61 / Chapter 3.3.6 --- Preparation of intestinal microsome --- p.62 / Chapter 3.3.7 --- Intestinal acyl coenzyme A: cholesterol acyltransferase (ACAT) activity measurement --- p.63 / Chapter 3.3.8 --- Statistics --- p.64 / Chapter 3.4 --- Results on intact female hamsters --- p.65 / Chapter 3.4.1 --- Growth and food intake --- p.65 / Chapter 3.4.2 --- Organ weights --- p.65 / Chapter 3.4.3 --- Effect of calcium deficiency diet on the plasma lipid profile and calcium concentration of hamsters --- p.65 / Chapter 3.4.4 --- Effect of calcium deficiency diet on hepatic cholesterol of hamsters --- p.65 / Chapter 3.4.5 --- Effect of dietary calcium on fecal neutral sterol output --- p.66 / Chapter 3.4.6 --- Effect of dietary calcium on fecal acidic sterol output --- p.66 / Chapter 3.4.7 --- Effect of dietary calcium on liver LDLR immunoreactive mass --- p.71 / Chapter 3.4.8 --- Effect of dietary calcium on liver CYP7A1 immunoreactive mass --- p.71 / Chapter 3.4.9 --- Effect of dietary calcium on liver LXR immunoreactive mass --- p.71 / Chapter 3.4.10 --- Effect of dietary calcium on liver SREBP-2 immunoreactive mass --- p.71 / Chapter 3.4.11 --- Effect of dietary calcium on liver HMGR immunoreactive mass --- p.71 / Chapter 3.4.12 --- Effect of dietary calcium deficiency on intestinal ACAT activity --- p.77 / Chapter 3.5 --- Results on ovariectomized hamsters --- p.79 / Chapter 3.5.1 --- Growth and food intake --- p.79 / Chapter 3.5.2 --- Organ weights --- p.79 / Chapter 3.5.3 --- Effect of calcium deficiency diet on plasma lipid profile and calcium concentration of hamsters --- p.79 / Chapter 3.5.4 --- Hepatic cholesterol --- p.79 / Chapter 3.5.5 --- Effect of dietary calcium on fecal neutral sterol output --- p.80 / Chapter 3.5.6 --- Effect of dietary calcium on fecal acidic sterol output --- p.80 / Chapter 3.5.7 --- Effect of dietary calcium on liver LDLR immunoreactive mass --- p.85 / Chapter 3.5.8 --- Effect of dietary calcium on liver CYP7A1 immunoreactive mass --- p.85 / Chapter 3.5.9 --- Effect of dietary calcium on liver LXR immunoreactive mass --- p.85 / Chapter 3.5.10 --- Effect of dietary calcium on liver SREBP-2 immunoreactive mass --- p.85 / Chapter 3.5.11 --- Effect of dietary calcium on liver HMGR immunoreactive mass … --- p.85 / Chapter 3.6 --- Discussion --- p.91 / Chapter Chapter 4 --- Effect of Dietary Magnesium Supplementation on Blood Cholesterol Level in Intact Male Hamsters --- p.94 / Chapter 4.1 --- Introduction --- p.94 / Chapter 4.2 --- Objective --- p.96 / Chapter 4.3 --- Materials and methods --- p.97 / Chapter 4.3.1 --- Hamsters --- p.97 / Chapter 4.3.2 --- Diets --- p.98 / Chapter 4.3.3 --- "Determination of serum lipid, lipoproteins and magnesium concentration" --- p.100 / Chapter 4.3.4 --- "Determination of cholesterol concentration in organ, fecal neutral and acidic sterols" --- p.100 / Chapter 4.3.5 --- Statistics --- p.100 / Chapter 4.4 --- Results on male hamster --- p.101 / Chapter 4.4.1 --- Growth and food intake --- p.101 / Chapter 4.4.2 --- Organ weights --- p.101 / Chapter 4.4.3 --- Effect of dietary magnesium on plasma lipid profile and magnesium concentration in hamsters --- p.101 / Chapter 4.4.4 --- Effect of dietary magnesium on hepatic cholesterol of hamsters..… --- p.102 / Chapter 4.4.5 --- Effect of dietary magnesium on fecal neutral sterol output --- p.105 / Chapter 4.4.6 --- Effect of dietary magnesium on fecal acidic sterol output --- p.105 / Chapter 4.6 --- Discussion --- p.107 / Chapter Chapter 5 --- Conclusion --- p.110 / References --- p.113

Cardiovascular disease (CVD) is a major health problem in developed countries and, with increasing prevalence in developing countries and Eastern Europe. Due to the increased incidence with advancing age, there is a need to develop primary preventive interventions to prolong the period of healthy life. Diet has a substantial influence on health and aging. The composition of the human diet plays an important role in the management of lipid and lipoprotein. In this respect, we have focused on the effects of two kinds of functional foods, tea seed oil and dietary onion on their hypocholesterolemic activities and underlying mechanisms in the present study. / Clearly, there are many claims on health benefits of Alliums , however, most, with the exception of garlic, have not received any rigorous or even gentle scientific investigation. Thus, the present study was carried out to explore hypocholesterolemic effects of onion supplementation. After fed for 2 weeks of the high fat high cholesterol diet, thirty-six 8-week male hamsters were divided into four groups. Control group was continued fed with high fat high cholesterol diet, while the other two experimental groups were fed control diet plus 1% (1OP) and 5% (5OP) onion powder for 8 weeks. It was found that feeding high dose of onion powder diet significantly prevented the increase in serum TC, Non-HDL-C and the ratio of non-HDL-C/HDL respectively in hamsters fed a 0.1% cholesterol diet. In contrast, the ratio of HDL/TC in high dose group was significantly increased than that in the control. Low onion dose group tended to have the similar effects as high dose group but, statistically, no difference was observed between the control and low dose groups. Besides, both doses of onion powder diets could significantly countered the increase in serum TG levels. High dose of onion supplementation tended to increase output of fecal neutral and acidic sterols, resulting in reduction of cholesterol retained and absorption. High dose of onion powder diet could significantly up- regulate SREBP-2, LXRbeta, and CYP7A1 protein expressions. The hypocholesterolemic activities of onion might due to the richness in alkyl and alkenyl sulfoxide compounds, anthocyanin, quercetin and cycloalliin, all of which have therapeutic effects. / In conclusion, diet plays an important role in reducing the risk of CVD. This has led to the search for specific foods and food components that may help to improve the serum lipoprotein profile. In present study, tea seed oil and onion was proved to help favorably modify the plasma lipoprotein profile, serving as health supplementation. However, their potential mechanisms were not fully studied and need to be further explored. / Interest in tea seed oil (named tea oil) as a cooking oil is increasing. However, its effect on blood cholesterol is not known. This study was therefore conducted to compare the hypocholesterolemic activity of tea oil with grape seed, canola and corn oils. Fifty 8-week-old male hamsters were first fed a high fat diet (5% lard), and supplemented with 0.1% cholesterol for 2 weeks and then divided into five groups. Control group was continuously fed high fat high cholesterol diet, while the experimental groups were fed high fat, high cholesterol diet plus 10% tea oil, grape seed oil, canola oil and corn oil for 12 weeks. Results showed that plasma total cholesterol (TC), non-HDL-cholesterol (non-HDL-C) and triacylglycerols (TG) in hamsters fed a 0.1% cholesterol diet containing tea, grape, canola or corn oil was significantly reduced compared with those in lard-fed group. Tea oil decreased only non-HDL-C and had no or little effect on HDL-C concentration, while grape oil reduced both. Besides, tea oil-fed hamsters excreted less neutral but greater acidic sterols compared with other three oils. Unlike grape oil, tea oil up-regulated sterol regulatory element binding protein (SREBP-2) and LDL receptor. Differences between tea oil and the tested vegetable oils could be attributable partially to >80% oleic acid in tea oil. / Guan, Lei. / Adviser: Chung Hau Yin. / Source: Dissertation Abstracts International, Volume: 72-04, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 98-125). / 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 Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.