Dissertations / Theses on the topic 'Chemotherapy-induced mucositis'

Thesis (Ph.D.) -- University of Adelaide, School of Medicine, Discipline of Medicine, 2006.
Includes author's previously published papers. "March 2006" Bibliography: leaves 168-191. Also available in a print form.

Class of 2011 Abstract
OBJECTIVES: To determine the solubility and stability of hydrocortisone in a ‘magic mouthwash; suspension. METHODS: A literature review was conducted to establish the most common ingredients in a ‘magic mouthwash’ suspension It was decided that the test suspension would consist of 75% commercially available diphenhydramine solution, 12.5% nystatin suspension (100,000 units/ml) , and 12.5% lidocaine solution (2% lidocaine). Powdered hydrocortisone was then added to the test suspensions at different concentrations and stored at 27C, 38C, and 48C. Aliquots were taken from each of the test samples at the time of compounding and at 4, 7, 13, 19, and 26 days to be analyzed by HPLC for degradation of hydrocortisone and percent hydrocortisone in suspension. RESULTS: At 27C, 98.5% of hydrocortisone was recovered after 26 days, versus 33.7% at 38C, and 7% at 48C. The solubility of hydrocortisone in the suspension was higher at higher temperatures, with 82% in solution at 48C, 70% at 38C, and 38% at 27C. CONCLUSION: The amount of hydrocortisone recovered deteriorated over time and at higher temperatures, and solubility of hydrocortisone in the suspension was greater at higher temperatures.

Oral mucositis is a common adverse side-effect caused by cancer treatments and can lead to mucosa toxicity. Patients with oral mucositis may experience extreme pain and may not be able to eat, drink and talk and, as a result, their quality of life is impaired. Thirty to eighty five percent of patients undergoing chemotherapy would develop oral mucositis. Preventing or reducing incidence of oral mucositis and its severity can help reduce patients’ sufferings. One of the methods to achieve this objective is the oral cryotherapy, which is a prophylactic intervention. However, there is no evidence-based guideline to instruct nurses on providing oral cryotherapy to cancer patients. The aims of this study are 1) to establish an evidence-based guideline on applying cryotherapy to reduce the incidence and severity of chemotherapy-induced oral mucositis, 2) to develop a standard nursing care and assess its transferability and feasibility, and 3) to develop a communication plan and evaluation plan for this guideline in an oncology ii- department for the targeted local hospitals in Hong Kong. A systematic search of four electronic journal databases identified seven articles corresponding to 6 randomized controlled trials (RCTs) on using oral cryotherapy for adult cancer patients. Five RCTs with high to weak quality reported supporting evidence for the beneficial effect of oral cryotherapy on chemotherapy-induced oral mucositis, whereas 1 RCT with moderate quality failed to identify supportive evidence for the use of oral cryotherapy. However, potential confounding factors were identified to be presented in that insignificant RCT. Hence, there was sufficient evidence to show that oral cryotherapy can significantly reduce chemotherapy-induced oral mucositis in adult cancer patients. An evidence based guideline for using cryotherapy on chemotherapy-induced oral mucositis in adult cancer patients was established. The transferability and feasibility of the proposed oral cryotherapy guideline were assessed. As identified, the clinical situation and patient characteristics in the local settings are similar to those who reported in the reviewed studies. Staff readiness, skills and resources are also readily available in the target clinical settings. Findings from the reviewed studies of oral cryotherapy can be transferred to the local target settings and are feasible to be implemented. It is also estimated that the innovated guidelines for cryotherapy can save HK$3,210,745 per year for the target setting. Stakeholders for the innovated guideline in the local setting were identified. And a communication plan was developed. A pilot study lasting for 10 weeks will be conducted to test the feasibility of the staff training session and the implementation of the oral cryotherapy guideline. Modification of innovated guidelines will be made after evaluating the data collected from the pilot study. Eventually, the final version of the evidence-based guideline will be established. A six months evaluation plan will be used to evaluate the implementation of the new guideline. The policy for adopting the oral cryotherapy will be determined with the outcome measures, including the incidence of chemotherapy-induced oral mucositis, mean of the oral mucositis score, staff satisfaction level, and the cost and benefit ratio of the innovated guideline.
published_or_final_version
Nursing Studies
Master
Master of Nursing

The gut microbiome has been shown to influence the efficacy and tolerance of cancer treatments. Mucositis is a dose-limiting side-effect of treatment, with adverse effects on nutritional intake. The objective of this thesis was to assess the therapeutic efficacy of a probiotic formulation in preventing and improving gut mucositis/dysbiosis. Methods: The effect of cancer treatments on quality of life (QoL) was assessed using the FACT-C questionnaire that included patient well-being and gut adverse symptoms (e.g., diarrhoea). Bacterial DNA was extracted from faecal samples, sequenced, and taxonomically examined. Participants rated faecal samples via the Bristol Stool Chart. Assessment of incidence/severity of neutropenia via white blood cell and neutrophil counts, circulating short chain fatty acids (SCFAs) levels assayed via gas chromatography with mass spectrometry (GC-MS), and plasma lipopolysaccharide (LPS) via the limulus amoebocyte lysate chromogenic endotoxin quantification kit were recorded. Results: No significant changes in QoL scores observed. Improvement in bowel function, with reduction in constipation or diarrhoea or absence of significant disturbance to bowel function was observed in 85% of participants. One participant developed febrile neutropenia and two developed bowel toxicity during the study, unrelated to the probiotic. No significant changes in microbiome diversity from baseline to end of study were observed. None of the participants had raised plasma LPS or SCFAs. Probiotics were deemed overall as safe and tolerable. In a related observational study of exceptional responders to chemotherapy, participants were found to have had a high intake of fruits, vegetables, and fibre. Conclusion: A healthy microbiome is associated with reduced adverse events and increased tolerability to cancer treatments. Enhanced gut health may also improve QoL during treatment. High fibre intake is likely to increase gut microbiome abundance and diversity, contributing capacity to tolerate chronic chemotherapy, improving long-term survival. In this study probiotics may have alleviated diarrhoea, constipation and maintain stool consistency/frequency during cancer treatments. Limitations of a single group study design make it difficult to ascribe definitive conclusions. Future studies warrant larger sample sizes, control groups and limit recruitment to a homogenous group of patients.

Background: Treatment-related symptoms continue to place a significant burden on many cancer patients. Many side effects require patients to engage in a range of self-management actions. While some studies have explored self-management of treatment-related side effects in Western settings, very few studies were identified that described the self-management practices of cancer patients in China. Objective: The purposes of this study are to: (1) Investigate Chinese cancer patients. self-management behaviours in dealing with the fatigue, nausea/vomiting and oral mucositis that result from treatment, as well as the perceived effectiveness of these behaviours and related self-efficacy in performing them. (2) Explore factors influencing symptom self-management behaviours using the Cancer Symptom Self-management Framework based on Grey, Knafl and McCorkle.s (2006) self-management framework as a guide. Methods: This study was divided into two phases. Phase One consisted of the translation and modification of two instruments. The adaptation of these instruments to ensure applicability in the Chinese context was achieved through semi-structured interviews with six cancer patients, and content evaluation with eight experienced oncology nurses. A pilot study was conducted with nine cancer patients to trial the questionnaire set in the Chinese context. Based on the results of Phase One, Phase Two involved a cross-sectional survey of Chinese cancer patients undergoing cancer treatment using these instruments. A total of 277 chemotherapy patients with fatigue and/or nausea and vomiting, and 100 radiotherapy patients with oral mucositis were surveyed. Results: Participants in this study reported a variety of self-management behaviours to cope with fatigue, nausea, vomiting and oral mucositis. There are some consistencies as well disparities between strategies that are frequently used and those rated as effective. For fatigue self-management, participants were more likely to use strategies related to rest and sleep, while activity enhancement strategies were rated as achieving higher relief. For nausea and vomiting self-management, dietary modification and taking medication were most frequently used and rated as moderately effective. Psychological strategies were used by more than a third of participants and were rated as mildly effective. Some other infrequently used strategies, such as distraction by keeping busy and acupressure, were rated as moderately effective. For oral mucositis self-management, having soft, bland food and keeping the mouth moisturised were most frequently reported and they were rated as achieving moderate relief. A prescribed mouthwash was used by most but not all participants and brought moderate relief. In general, patients had low-to-moderate self-efficacy in nausea and vomiting self-management behaviours, moderate self-efficacy in fatigue self-management behaviours, and low-to-moderate self-efficacy in oral mucositis self-management behaviours. In terms of the factors influencing symptom self-management, different predictors were identified affecting engagement in fatigue, nausea/vomiting and oral mucositis self-management behaviours. Self-efficacy scores of different behaviours were consistently found to be a positive predictor of the relief level from corresponding behaviours, after controlling for other variables. Perceived social support from health care professionals was identified as an important factor influencing nausea and vomiting self-management behaviours, while neighbourhood support was important for fatigue self-management. In addition, symptom distress was identified as an important factor influencing nausea and vomiting self-management. Conclusion: Similar to reports from overseas, Chinese cancer patients initiate a wide range of self-management behaviours in response to treatment-related side effects. While some behaviours were reported to provide relief, many did not. Given these results, this study has a number of practical implications for health care professionals, particularly in relation to developing tailored self-management programs for fatigue, nausea, vomiting and oral mucositis. Additionally, this study suggests a number of theoretical implications and directions for future research. It is envisaged that these recommendations may pave the way for further studies understanding and promoting cancer symptom self-management in Chinese people affected by cancer.

Previous findings revealed that engagement of SGLT-1 by orally administered D-glucose protects the intestinal mucosa from lipopolysaccharides (LPS)-induced injury. Here, we tested whether engagement of SGLT-1 protected also from doxorubicin (DXR)/5-fluorouracil (5-FU)-induced and DSS-induced intestinal injuries using a new synthetic compound named BLF501 as SGLT-1 agonist. A large set of experiments was performed in order to assess damages induction and recovery after treatment with DXR/5-FU and DSS with or without co-treatment with BLF501 with particular attention for intestinal epithelial integrity. We evaluated the preservation of correct epithelial structure, correct formation and functionality of junctional systems, electrophisiological properties and physiological functionality of small and large intestine. In conclusion, oral administration of BLF501 greatly accelerated recovery from mucosal injury induced by DXR (alone or in combination with 5-FU) and DSS. These data suggest a novel therapeutic approach to reduce the severity of chemotherapy-induced mucositis and a new approach for IBDs treatment.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior
CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior
Oral mucositis (OM) induced by antineoplasic drugs is an important, dose-limiting, and costly side effect of cancer therapy. Calotropis procera is a plant plant constitutively produces abundant latex that is reported to possess anti-inflammatory, bacteriolytic, insecticidal, analgesic properties. The present work aimed to describe the effect of laticifer proteins of Calotropis procera (LP) in the expression of pro-inflammatory cytokines and inducible enzymes, such as, cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in the model of OM in Hamsters. OM was induced by two intraperitoneal (i.p.) administrations of 5-Fluorouracil (5-FU) on the 1st and 2nd days (60 and 40 mg/kg, respectively) in hamsters (n=5). LP (0,25; 1; 5 E 25 mg / kg) was injected i.p. 24h before and 24h after mechanical trauma of the cheek pouches. Control group received only saline. On the 10th day, the animals were sacrificed and tissues from the cheek pouches were harvested. Macroscopical and histopathological (inflammatory cell infiltration, edema, hemorrhage and the formation of ulcerations and abscess) analysis as well as immunohistochemistry for TNF-, IL-1β, iNOS and COX-2 was performed in the cheek pouch tissue. Kruskal Wallis/Dunn was used as statistical tests. P<0.05 was accepted. Ethics Committee 036/10. The LP significantly inhibited macroscopical and histopathological parameters when compared to control group with maximum effect in macroscopic scores reaching 75% and 66% of maximum effect at the histopathological evaluation. The MPO activity was also significantly inhibited by LP in 91% at the same dose (p<0,001) and also inhibited the lost weight of 5- FU induced-oral mucositis. The cheek pouches of hamsters submitted to OM showed marked immunostaining for TNF-, IL-1β, iNOS and COX-2 on inflamed conjunctive (Cj) and epithelial (Ep) tissue compared with the cheek pouches of the normal control group. LP caused considerable reduction in the immunostaining for TNF- (62%,Cj; 70%,Ep), IL-1β (87%,Cj; 80%,Ep), iNOS (82%Cj; 52%Ep) and COX-2 (70%,Cj; 100%,Ep) in the check pouches tissue when compared with the group of animals subjected to experimental mucositis that received saline instead of LP. These findings show anti-inflammatory effects of LP in 5-FU-induced OM. The protective effect could be supported by the reduction of the expression of pro-inflammatory cytokines, such as TNF- and IL-1β and the enzymes iNOS and COX-2. The protective mechanism appears to involve inhibition of the expression of iNOS, COX-2, TNF-, and IL- 1β.
Mucosite oral (MO) induzida por drogas antineoplÃsicas à um importante fator limitante da dose e efeitos colaterais da terapia do cÃncer. Calotropis procera à uma planta que produz lÃtex constitutivamente abundante que à relatado possuir propriedades antiinflamatÃrias, bactericidas, inseticidas, analgÃsicas. O presente trabalho teve como objetivo descrever o efeito das proteÃnas do lÃtex da Calotropis procera (LP) na expressÃo de citocinas prÃ-inflamatÃrias (TNF-α e IL-1) e enzimas induzÃveis, como, ciclooxigenase-2 (COX-2) e Ãxido nÃtrico sintase induzÃvel (NOSi) no modelo de MO em hamsters. A mucosite oral foi induzida por duas administraÃÃes intraperitoneal (i.p) de 5-fluorouracil (5-FU) no 1  e 2 dias nas doses de 60 e 40 mg/kg, respectivamente nos animais (n = 5). As LP (0,25; 1; 5 E 25 mg/kg) foi injetado via i.p. 24h antes e 24h apÃs o trauma mecÃnico da mucosa jugal. O grupo controle recebeu apenas soluÃÃo salina. No 10 dia, os animais foram sacrificados e os tecidos da mucosa jugal foram colhidos. Foram realizadas no tecido mucosa jugal as anÃlises macroscÃpicas e histopatolÃgicas (infiltraÃÃo de cÃlulas inflamatÃrias, edema, hemorragia e à formaÃÃo de ulceraÃÃes e abscessos), bem como a imunohistoquÃmica para TNF-α, IL-1β, NOSi e COX-2. Foram utilizados Kruskal Wallis / Dunn como testes estatÃsticos, onde P <0,05 foi aceito. O estudo foi submetido ao Comità de Ãtica sob o protocolo 036/10. Observou-se que a LP inibiu significativamente parÃmetros macroscÃpicos e histopatolÃgicos, quando comparado ao grupo controle, com efeito mÃximo nos escores macroscÃpicos atingindo 75% e 66% do efeito mÃximo na avaliaÃÃo histopatolÃgica. A atividade de Mieloperoxidase (MPO) tambÃm foi significativamente inibida por LP em 91% com a mesma dose (p <0,001) quando comparado ao grupo controle e tambÃm inibiu a perda de peso em animais submetidos a mucosite oral e tratados com LP. A mucosa jugal dos animais submetidos a MO mostrou imunomarcaÃÃo para TNF-α, IL-1β, NOSi e COX-2 na conjuntiva inflamada (Cj) e tecido epitelial (Ep) em comparaÃÃo com o tecido jugal do grupo normal. LP causou reduÃÃo considerÃvel na imunomarcaÃÃo para TNF-α (62%, Cj, 70%, Ep), IL-1β (87%, Cj, 80%, Ep), NOSi (82% Cj; Ep 52%) e COX -2 (70%, Cj, 100%, Ep) no tecido jugal quando comparado com o grupo de animais submetidos à mucosite experimental que receberam salina, em vez de LP. Esses achados demonstram efeitos anti-inflamatÃrios de LP em MO induzida por 5-FU. O efeito protetor poderia ser suportado pela reduÃÃo da expressÃo das citocinas prÃ-inflamatÃrias, como TNF-α e IL-1β e na expressÃo de enzimas COX-2 e NOSi. O mecanismo de proteÃÃo parece envolver a expressÃo inibitÃria da NOSi, COX-2, TNF-α e IL-1β.

Mucositis is the damage that occurs to the alimentary canal from anti - cancer therapies. It is caused by chemotherapy, radiotherapy and combination therapy and affects a large proportion of patients. Despite its prevalence, an effective anti - mucositis agent has yet to be developed that protects the whole tube, although the use of keratinocyte growth factor ( Amgen ' s Palifermin ) has recently been approved for the prevention of oral mucositis. It is important to understand mechanisms controlling mucositis so that treatment can be targeted appropriately. This thesis has investigated some of the key components identified as being involved in mucositis as well as identifying new genes which contribute to chemotherapy - induced intestinal injury. The research chapters investigated : 1 ) Gene expression of the apoptosis - regulating Bcl - 2 family, p53 and caspase - 3, and the changes which occur in the intestine following chemotherapy treatment for cancer. 2 ) The effect of different chemotherapeutic agents on intestinal cells in vitro and the role p53 plays. 3 ) The mucositis caused by single dose irinotecan in the rat with breast cancer and the role of p53 in induction of intestinal damage. 4 ) The early gene changes that occur in the small intestine of the rat with breast cancer following irinotecan treatment. Firstly, to investigate the difference in susceptibility to damage between the small and large intestine, the protein expression of 8 members of the Bcl - 2 family ( 4 pro - apoptotic ; Bax, Bak, Bid, Bim and 4 anti - apoptotic ; Bcl - 2, Bcl - xL, Bcl - w, Mcl - 1 ) was quantified in jejunal and colonic sections taken from rats inoculated with breast cancer. It was found that there was significantly higher expression of the pro - apoptotic proteins, Bax, Bak, Bim and Bid, in the crypts of the jejunum compared to the colon. Furthermore, expression of the anti - apoptotic proteins, Bcl - 2, Bcl - xL and Bcl - w, was significantly lower in jejunal crypts compared to colonic crypts. Mcl - 1 expression was similar in both regions. Thus, the small intestine is an environment balanced to favour apoptosis through specific Bcl - 2 family protein expression profiles. The Bcl - 2 family regulates apoptosis in response to a variety of chemotherapy agents. However, it is unknown how Bcl - 2 family gene expression changes along with other apoptogenic factors following cytotoxic therapy in the normal intestine. To investigate this, sections of rat jejunum treated with methotrexate and duodenal biopsies from chemotherapy patients treated with various regimens for cancer were subjected to quantitative immunohistochemistry to detect Bcl - 2 family proteins, p53 and caspase - 3. Treatment caused expression of p53 and caspase - 3 to increase within the crypts and follow a similar pattern to apoptosis levels. Pro - apoptotic Bcl - 2 family members, Bax and Bak, were increased, while the anti - apoptotic protein, Mcl - 1, was significantly reduced. A significant increase in mRNA expression for Bax and Bak was noticed at 6 h, without a concurrent decrease in Mcl - 1. Thus, Bcl - 2 family genes were altered in the small intestine in both humans and rats, and this was irrespective of chemotherapy agent or regimen used. The best characterised changes which occur during chemotherapy - induced damage in the intestine are in the epithelial layer, although it is thought that pan #45 mucosal alterations are involved. Two intestinal cell lines were chosen to investigate changes in apoptosis, proliferation and protein expression following cytotoxic treatment with various chemotherapeutic agents. These were the rat IEC - 6 and human FHs 74 cell lines, which represent untransformed epithelial cells. The human breast carcinoma cell line, MCF - 7, was also used as a positive control. Intestinal cells were resistant to the occurrence of methotrexate toxicities within 24 h of treatment, modestly affected by irinotecan and extremely sensitive to doxorubicin. Doxorubicin caused a marked increase in p53 and p21 expression, which for irinotecan was less pronounced. The effect of cytotoxic treatment on Bcl - 2 family expression in intestinal cells varied, however the pro - apoptotic proteins, Bax and Bak, were generally upregulated following doxorubicin. Temporary inhibition of p53 using pifithrin alpha resulted in a significant improvement in cell survival in cancerous cell only and did not alter Bcl - 2 family expression. It was concluded that cultured epithelial cells exhibit varying sensitivities to different chemotherapeutic agents which is dependent on induction of p53 gene expression. The topoisomerase I inhibitor, irinotecan, is a chemotherapeutic agent commonly used in the treatment of colorectal cancer. It often induces severe mucositis with the most common symptom being diarrhoea. Previous research has shown that irinotecan damages the small and large bowel equally, which is unusual. This is characterised by an increase in apoptosis and a reduction in proliferation within epithelial crypts, an increase in inflammatory cell infiltrate in the lamina propria and excess mucin production. These investigations used two sequential doses of irinotecan. The early effect of a single dose of irinotecan on the intestine have yet to be studied. Thus the primary aim of this experiment was to examine in detail the changes caused by irinotecan at 6 and 48 h in the rat. A secondary aim was to investigate the role of p53 on induction of apoptosis and cell cycle arrest within intestinal crypts and the effect of temporary inhibition of the protein. Single dose irinotecan caused a decrease in body and small intestinal weight by 48 h after treatment. This was accompanied by crypt and villous degeneration, increased apoptosis and reduced proliferation within crypt epithelium as well as inflammatory infiltrate throughout lamina propria. An increase in Bax expression was seen at 6 h, however p53 protein levels remained relatively low until 48 h. Rats also treated with pifithrin alpha to inhibit p53 and had a significantly lower peak in apoptosis in the colon at 6 h, however did not show improvements in any other parameters tested. It was concluded that irinotecaninduced damage in the rat intestine is primarily p53 - independent, and that pifithrin alpha acts to inhibit apoptosis in the large intestine via a p53 - independent pathway. A study was designed to investigate the early genome - wide changes which occur following irinotecan treatment in the rat small intestine. Microarray analysis found that regulation of many genes was altered at 6 h following dual dose irinotecan. These genes were involved in apoptosis, cell cycle regulation, immune function, calcium homeostasis and protein turnover. Multiple genes from the MAP kinase pathway were also activated by irinotecan. The cystine protease, caspase - 1 was upregulated and was chosen for further investigations due to its role in apoptosis and inflammation. Real time PCR analysis confirmed the increase in gene expression at 6 h and also showed a return to baseline levels by 24 h which was followed by another modest increase at 48 h. It was concluded that irinotecan induces a wide range of gene changes within the intestine and that apoptosis and inflammatory damage pathways are activated during treatment. This thesis described key molecules in apoptosis and their role in induction of chemotherapy - induced intestinal mucositis. It has provided evidence of the importance of apoptosis in mucosal injury and also highlighted areas requiring further research. Results presented herein show that the Bcl - 2 family is involved in intestinal damage following many chemotherapy agents, whereas p53 is agent - specific. It has also shown that irinotecan causes intestinal damage via a mainly p53 - independent manner in the rat. It can be concluded that gastrointestinal mucositis is complex and activates multiple pathways to induce damage. Findings from this thesis will aid targeting of new anti - mucotoxic agents.
Thesis (Ph.D.) -- University of Adelaide, School of Medicine, 2006.

Mucositis is the damage that occurs to the alimentary canal from anti - cancer therapies. It is caused by chemotherapy, radiotherapy and combination therapy and affects a large proportion of patients. Despite its prevalence, an effective anti - mucositis agent has yet to be developed that protects the whole tube, although the use of keratinocyte growth factor ( Amgen ' s Palifermin ) has recently been approved for the prevention of oral mucositis. It is important to understand mechanisms controlling mucositis so that treatment can be targeted appropriately. This thesis has investigated some of the key components identified as being involved in mucositis as well as identifying new genes which contribute to chemotherapy - induced intestinal injury. The research chapters investigated : 1 ) Gene expression of the apoptosis - regulating Bcl - 2 family, p53 and caspase - 3, and the changes which occur in the intestine following chemotherapy treatment for cancer. 2 ) The effect of different chemotherapeutic agents on intestinal cells in vitro and the role p53 plays. 3 ) The mucositis caused by single dose irinotecan in the rat with breast cancer and the role of p53 in induction of intestinal damage. 4 ) The early gene changes that occur in the small intestine of the rat with breast cancer following irinotecan treatment. Firstly, to investigate the difference in susceptibility to damage between the small and large intestine, the protein expression of 8 members of the Bcl - 2 family ( 4 pro - apoptotic ; Bax, Bak, Bid, Bim and 4 anti - apoptotic ; Bcl - 2, Bcl - xL, Bcl - w, Mcl - 1 ) was quantified in jejunal and colonic sections taken from rats inoculated with breast cancer. It was found that there was significantly higher expression of the pro - apoptotic proteins, Bax, Bak, Bim and Bid, in the crypts of the jejunum compared to the colon. Furthermore, expression of the anti - apoptotic proteins, Bcl - 2, Bcl - xL and Bcl - w, was significantly lower in jejunal crypts compared to colonic crypts. Mcl - 1 expression was similar in both regions. Thus, the small intestine is an environment balanced to favour apoptosis through specific Bcl - 2 family protein expression profiles. The Bcl - 2 family regulates apoptosis in response to a variety of chemotherapy agents. However, it is unknown how Bcl - 2 family gene expression changes along with other apoptogenic factors following cytotoxic therapy in the normal intestine. To investigate this, sections of rat jejunum treated with methotrexate and duodenal biopsies from chemotherapy patients treated with various regimens for cancer were subjected to quantitative immunohistochemistry to detect Bcl - 2 family proteins, p53 and caspase - 3. Treatment caused expression of p53 and caspase - 3 to increase within the crypts and follow a similar pattern to apoptosis levels. Pro - apoptotic Bcl - 2 family members, Bax and Bak, were increased, while the anti - apoptotic protein, Mcl - 1, was significantly reduced. A significant increase in mRNA expression for Bax and Bak was noticed at 6 h, without a concurrent decrease in Mcl - 1. Thus, Bcl - 2 family genes were altered in the small intestine in both humans and rats, and this was irrespective of chemotherapy agent or regimen used. The best characterised changes which occur during chemotherapy - induced damage in the intestine are in the epithelial layer, although it is thought that pan #45 mucosal alterations are involved. Two intestinal cell lines were chosen to investigate changes in apoptosis, proliferation and protein expression following cytotoxic treatment with various chemotherapeutic agents. These were the rat IEC - 6 and human FHs 74 cell lines, which represent untransformed epithelial cells. The human breast carcinoma cell line, MCF - 7, was also used as a positive control. Intestinal cells were resistant to the occurrence of methotrexate toxicities within 24 h of treatment, modestly affected by irinotecan and extremely sensitive to doxorubicin. Doxorubicin caused a marked increase in p53 and p21 expression, which for irinotecan was less pronounced. The effect of cytotoxic treatment on Bcl - 2 family expression in intestinal cells varied, however the pro - apoptotic proteins, Bax and Bak, were generally upregulated following doxorubicin. Temporary inhibition of p53 using pifithrin alpha resulted in a significant improvement in cell survival in cancerous cell only and did not alter Bcl - 2 family expression. It was concluded that cultured epithelial cells exhibit varying sensitivities to different chemotherapeutic agents which is dependent on induction of p53 gene expression. The topoisomerase I inhibitor, irinotecan, is a chemotherapeutic agent commonly used in the treatment of colorectal cancer. It often induces severe mucositis with the most common symptom being diarrhoea. Previous research has shown that irinotecan damages the small and large bowel equally, which is unusual. This is characterised by an increase in apoptosis and a reduction in proliferation within epithelial crypts, an increase in inflammatory cell infiltrate in the lamina propria and excess mucin production. These investigations used two sequential doses of irinotecan. The early effect of a single dose of irinotecan on the intestine have yet to be studied. Thus the primary aim of this experiment was to examine in detail the changes caused by irinotecan at 6 and 48 h in the rat. A secondary aim was to investigate the role of p53 on induction of apoptosis and cell cycle arrest within intestinal crypts and the effect of temporary inhibition of the protein. Single dose irinotecan caused a decrease in body and small intestinal weight by 48 h after treatment. This was accompanied by crypt and villous degeneration, increased apoptosis and reduced proliferation within crypt epithelium as well as inflammatory infiltrate throughout lamina propria. An increase in Bax expression was seen at 6 h, however p53 protein levels remained relatively low until 48 h. Rats also treated with pifithrin alpha to inhibit p53 and had a significantly lower peak in apoptosis in the colon at 6 h, however did not show improvements in any other parameters tested. It was concluded that irinotecaninduced damage in the rat intestine is primarily p53 - independent, and that pifithrin alpha acts to inhibit apoptosis in the large intestine via a p53 - independent pathway. A study was designed to investigate the early genome - wide changes which occur following irinotecan treatment in the rat small intestine. Microarray analysis found that regulation of many genes was altered at 6 h following dual dose irinotecan. These genes were involved in apoptosis, cell cycle regulation, immune function, calcium homeostasis and protein turnover. Multiple genes from the MAP kinase pathway were also activated by irinotecan. The cystine protease, caspase - 1 was upregulated and was chosen for further investigations due to its role in apoptosis and inflammation. Real time PCR analysis confirmed the increase in gene expression at 6 h and also showed a return to baseline levels by 24 h which was followed by another modest increase at 48 h. It was concluded that irinotecan induces a wide range of gene changes within the intestine and that apoptosis and inflammatory damage pathways are activated during treatment. This thesis described key molecules in apoptosis and their role in induction of chemotherapy - induced intestinal mucositis. It has provided evidence of the importance of apoptosis in mucosal injury and also highlighted areas requiring further research. Results presented herein show that the Bcl - 2 family is involved in intestinal damage following many chemotherapy agents, whereas p53 is agent - specific. It has also shown that irinotecan causes intestinal damage via a mainly p53 - independent manner in the rat. It can be concluded that gastrointestinal mucositis is complex and activates multiple pathways to induce damage. Findings from this thesis will aid targeting of new anti - mucotoxic agents.
Thesis (Ph.D.) -- University of Adelaide, School of Medicine, 2006.

Chemotherapeutic agents, including irinotecan hydrochloride, are highly effective in the treatment of a range of cancers; however, they cause a variety of unwanted toxicities. Mucositis is the term used to describe the damage caused by cytotoxic agents to mucous membranes of the alimentary tract (AT). This condition affects 40-100% of patients depending on dose regimen. There is currently no effective treatment and the underlying molecular mechanisms are not fully understood. Previous research has shown that mucositis encompasses changes in stress response gene expression and subsequently activation of tissue injury and inflammation mediators. Matrix metalloproteinases (MMPs) are a group of zinc-dependent endopeptidases; which have been shown to play a role in tissue injury and inflammation in many gastrointestinal disorders. Furthermore, MMPs mediate these phenomena through the regulation of the extracellular matrix (ECM). This work aims to elucidate whether MMPs contribute to the pathogenesis of mucositis and whether these can be used as biomarkers for mucositis development or be targeted for future treatment strategies. To investigate these aims, studies were performed in an animal model of irinotecan-induced mucositis. A pilot clinical study was also conducted. To investigate the role of MMPs in mucositis pathogenesis, a time-course model of irinotecan-induced mucositis was utilised. Rats were administered with 200mg/kg irinotecan intraperitoneally at 0h and killed 30, 60, 90 min, 2, 6, 12, 24, 48, 72, 144h post- treatment. Sections were embedded in paraffin or frozen for further analysis. To ensure the accuracy of the molecular investigations in this thesis, the appropriateness of a range of housekeeping genes for normalisation of RT-PCR methods was investigated for the first time in this model. Findings indicated that the most suitable combination of genes to use is Ywhaz/UBC in the jejunum and UBC/β-actin in the colon or UBC if restricted to a single housekeeping gene. Subsequent molecular and histological assessments demonstrated a significant alteration in gene expression and tissue levels of MMPs and their inhibitors (TIMPs) following irinotecan (p˂0.05). The increase in MMP-2, -3, -9 and -12 levels was associated with inflammatory infiltrate and maximum tissue damage. In contrast, MMP-1 expression correlated with tissue restitution. Furthermore, histological techniques illustrated a substantial increase in total collagen deposits around crypts from 24h in the jejunum and colon. Fibronectin expression decreased significantly in both regions from 6-24h following treatment. Irinotecan induced a significant alteration in epithelial cell kinetics in both the jejunum and colon (p˂0.05) and this correlated with changes in ECM components. To determine if systemic MMP levels are useful markers of impending toxicity, a pilot clinical study was carried out. Eight patients receiving a variety of chemotherapy regimens were recruited. The most reported toxicity following treatment was diarrhoea. Analysis of patient serum samples revealed a 5.74-fold increase in systemic MMP-3 and a 2-fold increase in systemic MMP-12 levels following the administration of chemotherapy. Analysis of MMP-3 levels with patient symptoms revealed a correlation. Findings from this thesis provide clear evidence demonstrating a role for MMPs and ECM components in the pathogenesis of irinotecan-induced mucositis. Alterations in total collagen deposits and fibronectin levels in the AT following treatment may underlie the dysregulated cell kinetics following treatment hence leading to toxicity. Furthermore, preliminary findings from the pilot clinical study suggest that circulating MMPs are potential biomarkers of gastrointestinal toxicity induced by specific chemotherapy agents.
Thesis (Ph.D.) -- University of Adelaide, School of Medicine, 2012

Cheng Kin Fong.
"November 2001."
Thesis (Ph.D.)--Chinese University of Hong Kong, 2001.
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.
Mode of access: World Wide Web.
Abstracts in English and Chinese.

碩士
長庚大學
顱顏口腔醫學研究所
101
Objectives: Chemotherapy plays important role in current cancer therapy, but there are still many unsolved problems about host-therapeutics interaction. The aim of this study was to investigate the host responses after the 5-flurouracil (5-FU) administration and tried to find the target gene of 5-FU-induced oral mucositis via disease-animal model and transcriptomic analysis. Materials and Methods: We wanted to identify the target gene of 5-FU-induced oral mucositis. 5-FU-induced in oral mucositis was established by intraperitoneally administering mice with 100 mg/kg 5-FU. We evaluated the oral mucosal change under macroscopic and histological analysis first, and then transcriptomic analysis of gene expression profile was applied to identify the critical molecule associated with 5-FU-induced oral mucositis. Results: Our data showed that 5-FU-induced inflammation in the oral mucosa characterized by the erythema, hemorrhage, extensive ulcers, abscesses and inflammatory cell infiltration in oral mucosa. Network analysis of the 5-FU-affected genes by transcriptomic tool showed that the gene expression of Chitinase 3-like 4 (Chi3l4) and Bone gamma-carboxyglutamate protein, related sequence 1 (Bglap-rs1) were significant downregulated by 5-FU. Conclusion: 5-FU can down-regulate the gene expression of Chi3l4 and Bglap-rs1 then induce the oral mucositis.

Mucositis manifesting as diarrhoea is a common side effect of chemotherapy which remains poorly understood. It is one of a number of manifestations of alimentary mucositis, which affects the entire gastrointestinal tract. The exact number of patients that are affected by diarrhoea as a result of treatment is uncertain, although it is believed that approximately 10% of patients with advanced cancer will be afflicted. Despite advances in the understanding of oral and small intestinal mucositis over recent years, large intestinal mucositis, including diarrhoea, has not been well defined and the underlying mechanisms of the condition are yet to be established. The majority of the literature available concerning diarrhoea is based on clinical observations, with very little basic research existing. However, from the research conducted, it is likely that the intestinal microflora and mucins play a role in the development of chemotherapy-induced diarrhoea. This thesis will examine in detail what is known about the mechanisms of chemotherapy-induced diarrhoea (CID). Furthermore it will explore the potentially important relationship between intestinal microflora, the luminal environment and the subsequent development of chemotherapy-induced mucositis and diarrhoea. 5-Fluorouracil (5-FU) is a commonly used chemotherapy agent in clinical oncology practice. Two of its major side effects are mucositis and diarrhoea. The structure of mucins offers mucosal protection, and allows maintenance of intestinal flora by providing attachment sites and preventing bacterial overgrowth and/or penetration. Following treatment with 5-FU, we showed decreases in Clostridium spp., Lactobacillus spp. and Streptococcus spp., and an increase in Escherichia spp. in the jejunum. In the colon, 5-FU caused decreases in Enterococcus spp., Lactobacillus spp. and Streptococcus spp. Real time PCR of faecal samples showed decreasing trends in Lactobacillus spp. and Bacteroides spp., and an increasing trend in E. coli. Significant increases (p<0.05) were seen in Clostridium spp. and Staphylococcus spp. at 24 h. Goblet cell numbers decreased significantly in the jejunum from 24-72 h, with a significant increase in the percentage of cavitated goblet cells, suggesting 5-FU treatment causes significant changes in intestinal flora and mucin secretion in rats. These changes could result in systemic effects, and in particular may contribute to the development of chemotherapy-induced mucositis. Irinotecan causes cholinergic and delayed onset diarrhoea in patients, in which β-glucuronidase produced by gut bacteria is thought to be involved. Diarrhoea was observed in treated rats, as expected, following irinotecan treatment. β-glucuronidase expression increased in the jejunum and colon. Faecal flora changed quantitatively after treatment also, with increases in E. coli, Staphylococcus spp., and Clostridium spp. (all β-glucuronidase producing), and decreases in Lactobacillus spp., Bifidobacterium spp. (both beneficial bacteria), and Bacteroides spp. (β-glucuronidase producing, major component of intestinal flora), suggesting that irinotecan-induced diarrhoea may be caused by an increase in β-glucuronidase producing bacteria. However, the increase in bacteria may also be caused by irinotecan, further exaggerating the toxicity of the drug, and emphasising the need for these specific bacteria to be therapeutically targeted for successful treatment regimens to be accomplished. Mucus production appears to be increased after irinotecan treatment, which may contribute to the development of diarrhoea. Goblet cells were demonstrated to decrease significantly after irinotecan treatment. However, mucin secretion increased. Mucin expression changed significantly after treatment. Muc2 and Muc4 decreased significantly in the villi of the jejunum after treatment, Muc2 and Muc4 decreased significantly in the crypts. Muc2 decreased significantly in the colon. This indicates that irinotecan causes an increase in mucin secretion and a net decrease in mucin-producing goblet cells, and the expression of Muc2 and Muc4 in the gastrointestinal tract is altered following treatment. Increased mucin secretion is likely to be related to altered mucin expression, and may contribute to chemotherapy-induced diarrhoea. To determine if the changes to the intestinal microflora caused by chemotherapy could be translated to the clinic, a pilot clinical study was carried out. Sixteen patients experiencing CID were recruited to the study with two control subjects. A large proportion of patients (75%) demonstrated a reduced anaerobic component of their faecal microflora. A reduced diversity of species was also observed in patients. The majority of patients exhibited decreases in Clostridium spp., Lactobacillus spp. and Bifidobacterium spp., whilst all patients exhibited decreases in Bacteroides spp. and Enterococcus spp. Patients receiving antibiotics did not exhibit any marked differences to patients not receiving antibiotics. This indicates that the results observed in the animal studies are clinically relevant, and further research into this area should be undertaken. CID is associated with marked changes in the intestinal microflora. These changes may result in diminished bacterial functions within the gut, altering gut function and initiating intestinal damage, resulting in the onset of diarrhoea. In conclusion, there is clear evidence demonstrating chemotherapy treatment results in changes to the intestinal microflora and mucin secretion, which may be responsible in part for the development of severe mucositis and diarrhoea. Irinotecan toxicity may be compounded by the increase in β-glucuronidase producing bacteria. The intestinal flora of cancer patients experiencing CID is also noticeably different to that of healthy subjects. Irinotecan causes changes to mucin secretion, and the specific expression of Muc2, Muc4 and Klf4, suggesting that secretory control by the enteric nervous system may also be affected by chemotherapy. This research has extended the understanding of chemotherapy-induced mucositis and diarrhoea, complex side effects of chemotherapy. However, new areas for future research have also been identified.
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Thesis (Ph.D.) - University of Adelaide, School of Medicine, 2009

Mucositis manifesting as diarrhoea is a common side effect of chemotherapy which remains poorly understood. It is one of a number of manifestations of alimentary mucositis, which affects the entire gastrointestinal tract. The exact number of patients that are affected by diarrhoea as a result of treatment is uncertain, although it is believed that approximately 10% of patients with advanced cancer will be afflicted. Despite advances in the understanding of oral and small intestinal mucositis over recent years, large intestinal mucositis, including diarrhoea, has not been well defined and the underlying mechanisms of the condition are yet to be established. The majority of the literature available concerning diarrhoea is based on clinical observations, with very little basic research existing. However, from the research conducted, it is likely that the intestinal microflora and mucins play a role in the development of chemotherapy-induced diarrhoea. This thesis will examine in detail what is known about the mechanisms of chemotherapy-induced diarrhoea (CID). Furthermore it will explore the potentially important relationship between intestinal microflora, the luminal environment and the subsequent development of chemotherapy-induced mucositis and diarrhoea. 5-Fluorouracil (5-FU) is a commonly used chemotherapy agent in clinical oncology practice. Two of its major side effects are mucositis and diarrhoea. The structure of mucins offers mucosal protection, and allows maintenance of intestinal flora by providing attachment sites and preventing bacterial overgrowth and/or penetration. Following treatment with 5-FU, we showed decreases in Clostridium spp., Lactobacillus spp. and Streptococcus spp., and an increase in Escherichia spp. in the jejunum. In the colon, 5-FU caused decreases in Enterococcus spp., Lactobacillus spp. and Streptococcus spp. Real time PCR of faecal samples showed decreasing trends in Lactobacillus spp. and Bacteroides spp., and an increasing trend in E. coli. Significant increases (p<0.05) were seen in Clostridium spp. and Staphylococcus spp. at 24 h. Goblet cell numbers decreased significantly in the jejunum from 24-72 h, with a significant increase in the percentage of cavitated goblet cells, suggesting 5-FU treatment causes significant changes in intestinal flora and mucin secretion in rats. These changes could result in systemic effects, and in particular may contribute to the development of chemotherapy-induced mucositis. Irinotecan causes cholinergic and delayed onset diarrhoea in patients, in which β-glucuronidase produced by gut bacteria is thought to be involved. Diarrhoea was observed in treated rats, as expected, following irinotecan treatment. β-glucuronidase expression increased in the jejunum and colon. Faecal flora changed quantitatively after treatment also, with increases in E. coli, Staphylococcus spp., and Clostridium spp. (all β-glucuronidase producing), and decreases in Lactobacillus spp., Bifidobacterium spp. (both beneficial bacteria), and Bacteroides spp. (β-glucuronidase producing, major component of intestinal flora), suggesting that irinotecan-induced diarrhoea may be caused by an increase in β-glucuronidase producing bacteria. However, the increase in bacteria may also be caused by irinotecan, further exaggerating the toxicity of the drug, and emphasising the need for these specific bacteria to be therapeutically targeted for successful treatment regimens to be accomplished. Mucus production appears to be increased after irinotecan treatment, which may contribute to the development of diarrhoea. Goblet cells were demonstrated to decrease significantly after irinotecan treatment. However, mucin secretion increased. Mucin expression changed significantly after treatment. Muc2 and Muc4 decreased significantly in the villi of the jejunum after treatment, Muc2 and Muc4 decreased significantly in the crypts. Muc2 decreased significantly in the colon. This indicates that irinotecan causes an increase in mucin secretion and a net decrease in mucin-producing goblet cells, and the expression of Muc2 and Muc4 in the gastrointestinal tract is altered following treatment. Increased mucin secretion is likely to be related to altered mucin expression, and may contribute to chemotherapy-induced diarrhoea. To determine if the changes to the intestinal microflora caused by chemotherapy could be translated to the clinic, a pilot clinical study was carried out. Sixteen patients experiencing CID were recruited to the study with two control subjects. A large proportion of patients (75%) demonstrated a reduced anaerobic component of their faecal microflora. A reduced diversity of species was also observed in patients. The majority of patients exhibited decreases in Clostridium spp., Lactobacillus spp. and Bifidobacterium spp., whilst all patients exhibited decreases in Bacteroides spp. and Enterococcus spp. Patients receiving antibiotics did not exhibit any marked differences to patients not receiving antibiotics. This indicates that the results observed in the animal studies are clinically relevant, and further research into this area should be undertaken. CID is associated with marked changes in the intestinal microflora. These changes may result in diminished bacterial functions within the gut, altering gut function and initiating intestinal damage, resulting in the onset of diarrhoea. In conclusion, there is clear evidence demonstrating chemotherapy treatment results in changes to the intestinal microflora and mucin secretion, which may be responsible in part for the development of severe mucositis and diarrhoea. Irinotecan toxicity may be compounded by the increase in β-glucuronidase producing bacteria. The intestinal flora of cancer patients experiencing CID is also noticeably different to that of healthy subjects. Irinotecan causes changes to mucin secretion, and the specific expression of Muc2, Muc4 and Klf4, suggesting that secretory control by the enteric nervous system may also be affected by chemotherapy. This research has extended the understanding of chemotherapy-induced mucositis and diarrhoea, complex side effects of chemotherapy. However, new areas for future research have also been identified.
Thesis (Ph.D.) - University of Adelaide, School of Medicine, 2009

"April 2004"
Bibliography: leaves 121-142.
xviii, 142, [19] leaves : ill. (some col.), plates (some col.) ; 30 cm.
Title page, contents and abstract only. The complete thesis in print form is available from the University Library.
Attempts to build a complete understanding of the cellular mechanisms associated with gastrointestinal mucositis through investigations of the effects throughout the gastrointestinal tract of chemotherapeutic agents Methotrexate and Irinotecan, the possible ameliorating potential of the cytokine Interleukin-11 in reducing the side effects of chemotherapy, the expression of pro- and anti-apoptopic proteins and transcription factors along the gastrointestinal tract in normal human patients and the time-course of development of oral mucositis in human patients. Suggests that the entire gastrointestinal tract follows a similar pattern of development of mucositis.
Thesis (Ph.D.)--University of Adelaide, Dept. of Medicine, 2004

"April 2004"
Bibliography: leaves 121-142.
xviii, 142, [19] leaves : ill. (some col.), plates (some col.) ; 30 cm.
Attempts to build a complete understanding of the cellular mechanisms associated with gastrointestinal mucositis through investigations of the effects throughout the gastrointestinal tract of chemotherapeutic agents Methotrexate and Irinotecan, the possible ameliorating potential of the cytokine Interleukin-11 in reducing the side effects of chemotherapy, the expression of pro- and anti-apoptopic proteins and transcription factors along the gastrointestinal tract in normal human patients and the time-course of development of oral mucositis in human patients. Suggests that the entire gastrointestinal tract follows a similar pattern of development of mucositis.
Thesis (Ph.D.)--University of Adelaide, Dept. of Medicine, 2004

Several disorders of the gastrointestinal (GI) tract including ulcerative colitis, chemotherapy-induced mucositis and non-steroidal anti-inflammatory drug (NSAID)- induced enteropathy, are characterised by inflammation, ulceration, mucosal damage and malabsorption. Treatment options are variably effective, highlighting the need to broaden therapeutic approaches, including adjunctive strategies. Emu Oil, derived from subcutaneous and retroperitoneal Emu adipose tissue, is a rich source of fatty acids (FA). Despite limited rigorous scientific studies, topically applied Emu Oil has demonstrated potent anti-inflammatory properties in vivo. Previously, orally administered Emu Oil improved intestinal architecture in a rat model of mucositis, with early indications of enhanced intestinal repair. Accordingly, this thesis investigated the effects of orally administered Emu Oil in rat models of colitis (colonic damage), NSAID-enteropathy (small intestinal [SI] damage) and on the time course of SI repair in chemotherapy-induced mucositis. In the current study, Emu Oil improved colonic tissue damage associated with dextran sulphate sodium-induced colitis in Sprague Dawley rats and facilitated the repair process (Chapter 2). Improvements were indicated histologically by reduced intestinal damage severity scores and enhanced crypt compensatory elongation in the colon. These findings suggested the potential for Emu Oil to augment conventional treatment approaches for colitis. The effectiveness of Emu Oil in the colon provided impetus to further investigate Emu Oil action proximally, in the SI. In a rat model of chemotherapy (5-Fluorouracil; 5- FU)-induced mucositis, Emu Oil maintained SI villus height and crypt depth during the phase of maximal damage (Chapter 3). This was followed by an enhanced compensatory mucosal thickening, suggesting an acceleration of the repair process. Furthermore, Emu Oil significantly decreased myeloperoxidase (MPO) activity, indicative of acute inflammation, in the jejunum and ileum of 5-FU-injected rats. Potent anti-inflammatory properties of Emu Oil were reaffirmed in NSAID (Indomethacin)-induced enteropathy, whereby MPO activity in the jejunum and ileum of Indomethacin-treated rats was markedly decreased following Emu Oil administration (Chapter 4). Treatments for diseases such as coronary artery disease and GI disorders seek to minimise oxidative damage by free radicals through the use of antioxidants. Oils derived from ratites (flightless birds) predominantly comprise FA varying in composition between ratite species. The influence of farm location, rendering method, duration and storage mode was investigated for free radical scavenging activity (RSA) against 2,2-diphenyl-1-picryl hydracyl and primary oxidation status of Ratite Oils (Chapter 5). Emu Oil conferred the greatest RSA compared to Ostrich and Rhea Oil, potentially attributed to its high unsaturated FA: saturated FA ratio and non-triglyceride fraction minor constituents. Rendering and storage variables impacted on Emu Oil RSA and primary oxidation. This thesis identified Emu Oil as a safe, renewable and economical means to augment pharmaceutical options for GI disorders. A new mechanism of action for Emu Oil could represent a promotion of repair from injury together with decreased SI inflammation. This suggests potential for Emu Oil as an adjunct to conventional treatment approaches for colitis, cancer management and long-term NSAID usage.
Thesis (Ph.D.) -- University of Adelaide, School of Medical Sciences, 2013

5-fluorouracil (5-FU) is one of the most commonly prescribed anti-neoplastic drugs in modern cancer treatment. Although the drug is effective at destroying cancer cells, its administration is accompanied by serious, dose-limiting side effects, amongst the most prevalent of which is intestinal mucositis. This disorder is characterised by ulceration and inflammation of the small intestine, and sufferers often experience severe abdominal pain, nausea and diarrhoea. Despite its predominance, there are currently no definitive treatments for intestinal mucositis. Probiotics are defined as live bacteria which are able to exert beneficial physiological or therapeutic effects. Strains can be sourced from either food or the human microbiota, but must meet specific requirements prior to being officially recognised as probiotics. The mechanisms of probiotic action are highly species and strain specific, however, a number of strains have been shown to exert beneficial effects which may be suited to the treatment of intestinal mucositis. These include; inhibition of pathogenic bacterial growth and inflammation, maintenance of cell cycling and strengthening of the intestinal barrier. While the majority of probiotic research has focused on the use of live bacteria, there has been a recent interest in bioactive factors that are secreted by the bacterial cells into the cell-free supernatant (SN). There are a range of benefits to using SNs in preference to live bacteria, such as reduced risk of sepsis and greater quality control during production. This thesis represents the first detailed examination into the efficacy of probiotic-based SNs in the treatment of 5-FU-induced intestinal mucositis. Firstly, four different probiotic SNs were investigated in vitro for their ability to maintain cell growth following administration of 5-FU. The two strains deemed most effective where then assessed in an in vivo model of intestinal mucositis. Rats were treated with SNs both before and after 5-FU administration. Improvement was reported in some indicators of intestinal damage in rats following SN administration. However, the overall effects were less pronounced than expected, given the extent of improvement reported in the in vitro model. These findings suggested that a different screening method was required prior to in vivo examination, and that the current in vivo treatment protocol required review. As mucositis occurs only following chemotherapy administration, there is opportunity to administer therapeutic compounds prior to the onset of the disorder with the aim of preventing its development, rather than treating the damage. Two strains, Lactobacillus rhamnosus GG (LGG) and Escherichia coli Nissle 1917 (EcN), were examined for their ability to prevent 5-FU-induced reduction in intestinal barrier function and increased epithelial cell apoptosis in an in vitro model. Both SNs inhibited 5-FU-induced changes to barrier function and apoptosis. The success of these strains in a preventative treatment regime warranted further investigation in vivo. However, in the rat model of 5-FU-induced mucositis, no significant protective effects were observed. These findings highlighted inconsistencies between in vitro and in vivo models. One reason for this disagreement may have been due to the degradation of active compounds during gut transit. In order to determine if acidic or proteinase-rich conditions (two characteristics of the gastric environment) altered the efficacy of LGG and EcN SNs, a small in vitro pilot study was performed. All SNs not exposed to either acidic or proteinase-rich conditions were effective in maintaining cell proliferation following 5-FU administration, but the efficacy of LGG SN was significantly reduced following protease- and acid-treatment. However, neither treatment diminished the efficacy of EcN SN. These results suggested a requirement for new administration techniques to allow the SNs to reach their target area. In summary, this thesis explores the potential use of probiotic-derived factors to treat 5-FU-induced intestinal mucositis. It describes the capacity for LGG and EcN SNs to improve parameters of chemotherapy-induced damage in vitro. These strains were less effective in vivo, however, further investigations into effective delivery methods are warranted to ensure that the active compounds reach the small intestine. This thesis provides support for future investigations into the use of probiotic SNs for the treatment of intestinal mucositis.
Thesis (Ph.D.) -- University of Adelaide, School of Animal and Veterinary Sciences, 2013

The format of my thesis is as follows: a general introduction, a literature review, two research chapters, a second literature reviews, three research chapters, a general discussion and references. During my candidature, I made significant effort to publish my research findings. Each research chapter is presented in its original publication format. This may result in slight repetition between chapters arising from the same study. My thesis has three distinct themes relating to the pathobiology of chemotherapy-induced gut toxicity. The first aims to characterise the extent of tight junction disruption in the alimentary tract following chemotherapy treatment (clinically and preclinically), giving rise to the first two research chapters (Chapter 2 and 3). The first publication (Chapter 2) was completed early in my candidature (2013). The second publication (Chapter 3) arose from independent research funding I obtained from the Australian Dental Research Foundation. Together, these chapters formed the scope and theme for my PhD, and are therefore followed by two literature reviews and the remaining four research chapters. The second theme relates to involvement of innate immune regulation in the development of chemotherapy-induced gut toxicity and barrier dysfunction, giving rise to an additional two primary research chapters (Chapter 6 and 7). The third aim of this thesis was to develop a high throughput in vitro model for the study of chemotherapy-induced mucosal injury and targeted therapeutic approaches. This is summarised in Chapters 8 and 9. During my candidature, I had the opportunity to work with Professor Stephen Sonis from Dana- Farber Harvard Cancer Centre, Harvard University, Boston. After presenting my work at the Multinational Association for Supportive Care in Cancer in 2014 (Miami, USA), Professor Sonis and I developed the hypothesis that gut-derived inflammation affects central neurological functions. This formed the basis for my secondary literature review (Chapter 5) as well as an additional literature review on cytokine-mediated blood brain barrier permeability and its involvement in chemotherapy-induced cognitive decline. The latter literature review is not included as a chapter in this thesis, but as an appendix in its original publication format (PDF).
Thesis (Ph.D.) -- University of Adelaide, School of Medicine, 2016.