Identification Of The Pain Pathway From The Rectum And Its Mechanisms Of Activation
Funder
National Health and Medical Research Council
Funding Amount
$566,931.00
Summary
Abdominal pain is one of the most common reasons why patients seek medical attention. It is now known that irritable bowel syndrome (IBS) is one of the major causes of abdominal pain, but the reason why people experience pain from the gut is not known. This project will identify which sensory nerves in the gut wall signal pain to the spinal cord during conditions that mimic IBS and the precise mechanisms that activate these sensory neurons during IBS-like inflammation will be investigated.
Intestinal Adaptation Following Massive Small Intestinal Resection: Mechanisms And Management
Funder
National Health and Medical Research Council
Funding Amount
$256,980.00
Summary
Short bowel syndrome (SBS) remains a major clinical problem in paediatric and adult clinical practice. The Department of Gastroenterology and Clinical Nutrition at the Royal Children's Hospital has gained recognition as a national centre of excellence for the management of infants and children with SBS and intestinal failure. Due to the significant personal and heath-care burden related to SBS there has been an urgent need to improve understanding about the process of intestinal adaptation follo ....Short bowel syndrome (SBS) remains a major clinical problem in paediatric and adult clinical practice. The Department of Gastroenterology and Clinical Nutrition at the Royal Children's Hospital has gained recognition as a national centre of excellence for the management of infants and children with SBS and intestinal failure. Due to the significant personal and heath-care burden related to SBS there has been an urgent need to improve understanding about the process of intestinal adaptation following massive small bowel resection (MSBR) in order to develop new treatments aimed at improving clinical outcome for patients with SBS. Over the past 5 years we have developed a preclinical model for the study of intestinal adaptation in infants using the juvenile pig. Our recent studies in this model have revealed that elemental formula is inferior to whole protein formula suggesting that the current clinical recommendations need urgent re-evaluation. Using the preclinical model in this proposal, we aim to define the mechanisms underlying the adaptive response and evaluate novel therapies aimed at enhancing adaptation following MSBR. Supplementation of enteral feeds with bovine colostrum isolate resulted in normal growth in the preclinical model despite MSBR. In this proposal we plan to advance this observation for the first time to human clinical trials in infants with SBS. Even small gains in enteral tolerance during the early post-operative period may have a significant impact on morbidity and mortality of children with SBS due to parenteral-nutrition related liver disease and gut-related sepsis. This research proposal provides a unique link between studies aimed at providing the scientific basis for understanding the mechanisms of intestinal adaptation using an established preclinical model and translating the results of these studies onto human trials, taking advantage of the clinical expertise available in the management of children with SBS.Read moreRead less
How Spinal Afferent Nerves Cause Vasodilation Of Mesenteric Arteries
Funder
National Health and Medical Research Council
Funding Amount
$353,250.00
Summary
Healthy function of the gastrointestinal tract requires an adequate blood supply during periods of varying demand. Inadequate blood supply to the gut contributes to disorders ranging in severity from mild through to lethal. Reduced blood supply to the gut is a trigger for multiple organ failure syndrome; a leading cause of death in critically ill patients following major surgery, trauma or haemorrhage. It is believed that damage to the lining of the gut, during periods of reduced flow, trigger i ....Healthy function of the gastrointestinal tract requires an adequate blood supply during periods of varying demand. Inadequate blood supply to the gut contributes to disorders ranging in severity from mild through to lethal. Reduced blood supply to the gut is a trigger for multiple organ failure syndrome; a leading cause of death in critically ill patients following major surgery, trauma or haemorrhage. It is believed that damage to the lining of the gut, during periods of reduced flow, trigger inflammatory mechanisms throughout the body. Mesenteric ischaemia is a disorder which occurs as a chronic, non-occlusive form, or as acute episodes, which are often lethal, . Temporary increases in blood supply are also known to play a vital role in protecting the gut from acid, toxins and attack by pathogens. The major mechanism underlying increases in bloody supply is dilation of arterial vessels. This occurs focally, at the site of damage, via local mechanisms, but this is supplemented by a more widespread dilation of arteries upstream, mediated by branches of sensory neurones that innervate blood vessels directly. Currently, there is no information about how these sensory neurones are activated. This is crucial to understand how they work. We hypothesise that these sensory neurones are activated by chemical and mechanical stimuli in the gut wall, which make them release vasodilator chemicals onto the arteries upstream and thus amplify the local increases in blood flow. We will test this by recording from sensory nerves, identifying the ones which project to blood vessels and determine which chemicals and mechanical stimuli they are excited by. We will then fill them with dye, using a method that we have recently developed, to visualise their branching patterns both inside and outside the gut wall. In this way, we will understand how this powerful protective mechanism is activated at times of need, and how it may fail under some circumstances.Read moreRead less
Exclusive Enteral Nutrition In Children With Crohns Disease
Funder
National Health and Medical Research Council
Funding Amount
$364,549.00
Summary
Crohn's disease occurs at any age, even in young children. One treatment for CD involves the use of a special drink (nutritional treatment). This works well for CD in children, helping to settle symptoms and heal the bowel surface. Despite being established as a treatment for 20 years, it is not yet clear how it works. These studies aim to work out how nutritional treatments work in CD. This should expand our knowledge about CD and may lead to further ways to prevent or manage CD.
Mechanisms Of Action Of The Trefoil Peptides In Promoting Healing In Models Of Inflammatory Bowel Disease
Funder
National Health and Medical Research Council
Funding Amount
$365,270.00
Summary
Preliminary experiments from our laboratory have shown that members of a family of small proteins called trefoil peptides, found naturally in the stomach, intestine and colon, are able to shorten the healing time of ulcers and reduce inflammation, in an animal model of inflammatory bowel disease. Crohn's disease and ulcerative colitis together make up the human inflammatory bowel diseases, or IBD for short. They afflict many members of the community, are debilitating, expensive to treat, and cur ....Preliminary experiments from our laboratory have shown that members of a family of small proteins called trefoil peptides, found naturally in the stomach, intestine and colon, are able to shorten the healing time of ulcers and reduce inflammation, in an animal model of inflammatory bowel disease. Crohn's disease and ulcerative colitis together make up the human inflammatory bowel diseases, or IBD for short. They afflict many members of the community, are debilitating, expensive to treat, and current treatments like corticosteroids and suppressors of the immune system have unpleasant and health-threatening side effects. There are therefore good reasons for the development of new forms of therapy which will be better tolerated and which are specific in their actions. We believe that the trefoil peptides may be good candidates on which new treatments for inflammatory disease might be based. The studies outlined in this proposal will test the best route of administration, and how often to give trefoil peptides in order to relieve the symptoms of experimental IBD. In addition the effectiveness of the trefoils will be compared to other agents currently used in IBD treatment, or which are known to relieve inflammation or speed the healing of the ulcerated colon. We will also carry out experiments designed to work out the mechanisms by which the trefoils' healing effects are mediated, and finally we will characterise a new member of the trefoil peptide family which we have recently discovered.Read moreRead less
Novel Applications Of Ghrelin Peptides In Mouse Models Of Inflammatory Bowel Disease
Funder
National Health and Medical Research Council
Funding Amount
$243,116.00
Summary
Inflammatory bowel disease (IBD) is a debilitating, chronic condition that often affects patients in the primes of their lives. A limited number of treatments are currently available for these patients and those that are available often have serious side effects, including growth restriction in children. Ghrelin is a natural hormone that has been shown to suppress many features of IBD. This project will investigate the potential of ghrelin as a new treatment for inflammatory bowel disease.
Motor Patterns Of Colonic Transit And Pathophysiology Of Severe Constipation.
Funder
National Health and Medical Research Council
Funding Amount
$196,018.00
Summary
This project aims to clarify the contractile patterns of the human colon which underlie the very common and distressing condition of constipation. We will be relating symptoms of constipation from a large number of sufferers with actual measurements of contractions and flow of content along the colon in these patients. The aim will be to try and identify abnormal patterns responsible for the constipation so that future studies can target appropriate drugs at the responsible defect. A better unde ....This project aims to clarify the contractile patterns of the human colon which underlie the very common and distressing condition of constipation. We will be relating symptoms of constipation from a large number of sufferers with actual measurements of contractions and flow of content along the colon in these patients. The aim will be to try and identify abnormal patterns responsible for the constipation so that future studies can target appropriate drugs at the responsible defect. A better understanding of clusters or symptoms and how they might predict such underlying abnormalities is crucial for the safer and more cost effective diagnosis and treatment of affected patients. Pharmacological studies in the human as well as on tissue obtained from affected patients at surgery will be conducted to better understand the presumptive abnormalities affecting the nerves within the colon in constipation.Read moreRead less
Inflammatory Bowel Disease (IBD) has two clinical forms known as Ulcerative Colitis (UC) and Crohn's Disease (CD). These are severe diseases which predominantly affect young people. They are occasionally fatal and often severely debilitating. Treatment of UC frequently requires removal of the large bowel and life long wearing of an ileostomy bag. While this is curative, its psychological and life style effects are very disturbing particularly in the young. The cause of IBD is unknown, although i ....Inflammatory Bowel Disease (IBD) has two clinical forms known as Ulcerative Colitis (UC) and Crohn's Disease (CD). These are severe diseases which predominantly affect young people. They are occasionally fatal and often severely debilitating. Treatment of UC frequently requires removal of the large bowel and life long wearing of an ileostomy bag. While this is curative, its psychological and life style effects are very disturbing particularly in the young. The cause of IBD is unknown, although it is clear that there are both genetic and environmental factors. We have developed a model of IBD in mice which appears to be very like human UC. We have generated genetically modified mice in which it appears that the mucous secreted by their bowel wall is different from normal. We propose to investigate how this change leads to UC. It appears likely that the mucous is defective and can not prevent some of the normal bacteria or other material present in the stools from entering the bowel wall and causing chronic inflammation. If we can show that this is the case, it adds strong support to the the idea that a similar genetic trait may occur in some humans and that this may be one of the genetic components which renders them susceptible to IBD. Put another way, it would be a pointer to the type of genetic defect which may underlie susceptibility in humans and so help to focus the search for the genetic component. Understanding genetic factors underlying disease susceptibility is vitally important to inform genetic counselling. In addition, understanding the various factors which lead to IBD is critical to developing rational treatments which target cause rather than the symptoms of the disease.Read moreRead less
Factors Controlling Leucocyte Migration In Healthy Intestine And In Inflammatory Bowel Disease
Funder
National Health and Medical Research Council
Funding Amount
$195,217.00
Summary
Inflammatory bowel diseases (IBD) are relapsing and remitting disorders of the intestine that create substantial disability in a relatively young population of patients. Our treatments for these conditions have changed little in the last 30 years and they are commonly accompanied by side effects. Research into the mechanisms controlling the gut inflammation offers promise for the development of novel, targeted and less toxic therapies. The major mediators of damage in IBD are white blood cells r ....Inflammatory bowel diseases (IBD) are relapsing and remitting disorders of the intestine that create substantial disability in a relatively young population of patients. Our treatments for these conditions have changed little in the last 30 years and they are commonly accompanied by side effects. Research into the mechanisms controlling the gut inflammation offers promise for the development of novel, targeted and less toxic therapies. The major mediators of damage in IBD are white blood cells recruited from the circulation to affected intestine. This recruitment is induced by the production in damaged intestine of chemokines, proteins of the immune system that attract and activate white blood cells. Chemokines act through chemokine receptors on the surface of white blood cells, and earlier research by our group has demonstrated that these chemokine receptors can be functionally modulated by neuropeptides, proteins unrelated to chemokines that normally transmit messages within the nervous system. This project aims to explore the chemokines and chemokine receptors responsible for the recruitment of white blood cells to normal and IBD-affected intestine, in order to determine therapeutic targets for novel treatments. Moreover, the role of neuropeptides in modulating the recruitment of white blood cells to the intestine will be examined in cells from the human intestine, both normal and IBD-affected, as well as in an animal model of IBD. This project will provide an understanding of the signals responsible for the attraction of damaging white blood cells to sites of inflammation in the bowel and will indicate mechanisms used by the immune system to regulate those signals. It has the potential to direct us to new therapies that use highly targeted and physiologically appropriate approaches to controlling white blood cell trafficking in health and disease.Read moreRead less