Identifying Optimal Sustainable Cooling Strategies For The Most Vulnerable During Heatwaves
Funder
National Health and Medical Research Council
Funding Amount
$1,115,640.00
Summary
Current guidance warns against electric fan use in heatwaves without any supporting evidence. This Project aims to identify how fans and other parallel low-resource strategies can reduce the risk of heat-related illness in the most vulnerable during simulated hot/humid and very hot/dry heat wave conditions. This information will be used to develop simple heat adaptation strategies that also mitigate unsustainable energy demands and the destructive environmental impact of air conditioning.
Neural Mechanisms Mediating Inhibitory Influences Of Hyperthermia, Fever And Age On Water Intake
Funder
National Health and Medical Research Council
Funding Amount
$324,125.00
Summary
An adequate intake of fluid following losses of body water that can occur as the result of sweating in hot weather, exercise, vomiting or diarrhoea is necessary so that dangerous levels of dehydration do not occur. Thus, it is important for our health that thirst is properly stimulated when we do become dehydrated, in order that we are aware that we must drink water. There may be conditions in which the thirst mechanism is inhibited, and the aim of these experiments is to identify and understand ....An adequate intake of fluid following losses of body water that can occur as the result of sweating in hot weather, exercise, vomiting or diarrhoea is necessary so that dangerous levels of dehydration do not occur. Thus, it is important for our health that thirst is properly stimulated when we do become dehydrated, in order that we are aware that we must drink water. There may be conditions in which the thirst mechanism is inhibited, and the aim of these experiments is to identify and understand mechanisms by which the thirst mechanism in the brain is supressed. We have observed that a high body temperature may have an inhibitory influence on thirst in rats, and it is also known that thirst mechanisms are depressed in elderly people. If we can identify the regions of the brain that are involved and the mechanisms underpinning this reduced thirst, then it will be possible to identify and alert people at risk and to design strategies to prevent dangerous levels of dehydration occurring due to reduced thirst, particularly in the elderly. This may also apply to to people who may be working or undertaking vigorous exercise in hot weather or taking certain medications.Read moreRead less
Thirst And Vasopressin Secretion In Left Ventricular Dysfunction
Funder
National Health and Medical Research Council
Funding Amount
$130,950.00
Summary
Water homeostasis is essential for life and is achieved by a balance between water intake, controlled by thirst, and output controlled by the kidneys via the hormone vasopressin. In health the control mechanisms of thirst and vasopressin are very similar. Both are controlled by the brain. Thirst and vasopressin secretion are activated when the body becomes dehydrated or when blood volume is low. Heart failure occurs when the heart cannot pump sufficient blood to meet the body's demands. It has a ....Water homeostasis is essential for life and is achieved by a balance between water intake, controlled by thirst, and output controlled by the kidneys via the hormone vasopressin. In health the control mechanisms of thirst and vasopressin are very similar. Both are controlled by the brain. Thirst and vasopressin secretion are activated when the body becomes dehydrated or when blood volume is low. Heart failure occurs when the heart cannot pump sufficient blood to meet the body's demands. It has a worse outlook than many cancers including breast and prostate cancer. Because the body's demands for oxygen are not being met, the body reacts as though blood volume is low. A variety of responses lead to excess body water with congestion of various organs and oedema. The aim of this research is to explore to what extent and how, the controls of thirst and vasopressin secretion are altered in heart failure by investigating both a rat model of heart failure and patients after a heart attack. From these studies we will gain a greater understanding of how body water homeostasis control mechanisms are altered which will aid our understanding of potential treatment options for this deadly disease.Read moreRead less
ProbioticTreatment Of Diarrhoeal Disease And Malnutrition In Top End Aboriginal Children
Funder
National Health and Medical Research Council
Funding Amount
$332,036.00
Summary
Aboriginal children in the Top End of Australia have high rates of hospital admission for diarrhoea and malnutrition. We have discovered that underlying small intestinal damage in these children is an important contributor to the high complication rates and longer lengths of stay in hospital compared to non-Aboriginal children. This research proposes to continue our work on small intestinal damage by using two non-invasive tests of gut function, namely a sugar absorption test and novel breath te ....Aboriginal children in the Top End of Australia have high rates of hospital admission for diarrhoea and malnutrition. We have discovered that underlying small intestinal damage in these children is an important contributor to the high complication rates and longer lengths of stay in hospital compared to non-Aboriginal children. This research proposes to continue our work on small intestinal damage by using two non-invasive tests of gut function, namely a sugar absorption test and novel breath test. The sugar permeability test involves the children drinking a solution of the two sugars lactulose and rhamnose, and measuring their absorption into the blood 90 minutes later using a sophisticated measuring instrument called HPLC, which can measure minuscule amounts of sugars and is set up at Royal Darwin Hospital. The breath test involves children drinking another sugar solution with a special non-radioactive marker called a stable isotope of carbon, and measuring changes in the amount of this marker in carbon dioxide from the breath at timed periods after drinking the sugar solution. The breath is analysed in Adelaide using another sophisticated instrument. These tests are being used to measure abnormal sugar absorption due to intestinal damage, which is particularly common in Aboriginal children during the weaning period of 4-18 months. Our hypothesis is that treatment with 'healthy germs' (probiotics) like those in certain yoghourts will colonise the gut, stimulate immunity and reduce the presence of 'nasty germs' (pathogenic bacteria) in the intestines of Aboriginal children which contribute to the need for their hospitalisation with diarrhoea and malnutrition. If this hypothesis is correct, then this research will provide the best kind of evidence for reducing the need for hospital treatment by treating all cases of diarrhoea with these probiotics and possibly even decreasing the gut damage of children in the weaning period by including probiotics in their dietsRead moreRead less
NMR Of Red Cells: Plasma Membrane Oxidoreductase, And Cation Transport
Funder
National Health and Medical Research Council
Funding Amount
$192,388.00
Summary
An interesting paradox exists with respect to the 'central' function of the red blood cell (RBC): it delivers the main oxidising capacity to the body (O2), but it also carries the chemically opposite functionality in its membrane, namely reducing capacity. The reduction of many oxidised proteins and metabolites in blood plasma is mediated by a plasma-membrane oxido-reductase (PMOR). Ascorbic acid (vitamin C) dramatically accelerates this rate of reduction but its precise molecular role is unknow ....An interesting paradox exists with respect to the 'central' function of the red blood cell (RBC): it delivers the main oxidising capacity to the body (O2), but it also carries the chemically opposite functionality in its membrane, namely reducing capacity. The reduction of many oxidised proteins and metabolites in blood plasma is mediated by a plasma-membrane oxido-reductase (PMOR). Ascorbic acid (vitamin C) dramatically accelerates this rate of reduction but its precise molecular role is unknown; neither is the immediate source of the reducing equivalents (electrons) known. Novel, non-invasive, 13C NMR methods have been developed, and others are planned in this project, to study the rate of reduction of Otest? compounds, including 13C-ferricyanide, and reactions of 13C-ascorbate. This will provide a quantitative understanding of the kinetics of the redox reactions in the intact cell. The transfer of negative charges (electrons) from the cell, in the longer term (minutes) inevitably must be matched by the movement of cations (positive charges). The main cation flux is mediated by Na+, K+-ATPase, but various cation exchange pathways are also involved in the total Oionic economy? of the cell. Of special interest will be the calcium-activated K+ (or Gardos) channel. This Oopens? inappropriately in malaria, sickle cell anaemia, and under blood bank storage conditions, and this is thought to be the basis of some of the pathological events in these conditions. The alkali-metal cation exchange pathway ( Na+-Li+) is more activate in the red cells of many patients with hypertension. So, multiple-quantum NMR methods will be used to monitor membrane transport and binding of cations to characterise the kinetics and regulation of the K+-channel, and the Na+-Li+ exchange reactions. The significance will lie in a basic understanding of, and possible 'diagnostic methods' for the biochemical processes that occur in red blood cells in health and disease.Read moreRead less