Surface Tension Of Upper Airway Lining Liquid: Role In Obstructive Sleep Apnoea Hyponoea Syndrome
Funder
National Health and Medical Research Council
Funding Amount
$494,833.00
Summary
The obstructive sleep apnoea hypopnoea syndrome (OSAHS) refers to a condition in which throat blockage occurs during sleep leading to breathing difficulties, including cessation of breathing for short periods of time. OSAHS affects both men and women but is amongst the commonest of chronic disorders of adult males, occurring in 5% of men over the age of 45 years. In the proposed studies we will examine the effect that the liquid layer that lines the throat, has on the ability of the airway to st ....The obstructive sleep apnoea hypopnoea syndrome (OSAHS) refers to a condition in which throat blockage occurs during sleep leading to breathing difficulties, including cessation of breathing for short periods of time. OSAHS affects both men and women but is amongst the commonest of chronic disorders of adult males, occurring in 5% of men over the age of 45 years. In the proposed studies we will examine the effect that the liquid layer that lines the throat, has on the ability of the airway to stay open during sleep. In particular we will examine whether coating the throat with a substance that decreases stickiness will help to prevent the occurrence of episodes of throat blockage during sleep in persons with OSAHS. We will also explore the role of saliva production and swallowing during sleep in maintaining a low stickiness of the throat and whether this liquid lining is abnormal in OSAHS patients. These studies will establish the potential usefulness of decreasing the stickiness of the liquid lining the throat as a treatment for OSAHS.Read moreRead less
Synchrotron X-ray Assessment Of Airway Surface Physiology For Cystic Fibrosis
Funder
National Health and Medical Research Council
Funding Amount
$778,228.00
Summary
We seek a cure or long-lasting therapy for the fatal airway disease in cystic fibrosis. Disease is caused by a shallow and dehydrated airway surface liquid (ASL), allowing bacteria to infect the lung. We can introduce a corrective gene into mouse airways where it can be effective for over 1 yr, but no fast, accurate and non-invasive measurement exists to test if treatments are successful. We will develop methods using synchrotron light to directly measure ASL depth changes in live mouse airways.
The Obstructive Sleep Apnoea syndrome (OSA) refers to a condition in which throat blockage occurs during sleep leading to breathing difficulties, including cessation of breathing for short periods of time. OSA is amongst the commonest chronic disorders of adult males, occurring in 5% of men over the age of 45 years. We will examine how muscles in the throat act to keep the airway open. We will also study how tongue and jaw position influences throat blockage. The throat is lined with fluid which ....The Obstructive Sleep Apnoea syndrome (OSA) refers to a condition in which throat blockage occurs during sleep leading to breathing difficulties, including cessation of breathing for short periods of time. OSA is amongst the commonest chronic disorders of adult males, occurring in 5% of men over the age of 45 years. We will examine how muscles in the throat act to keep the airway open. We will also study how tongue and jaw position influences throat blockage. The throat is lined with fluid which may become dry and sticky if, for example, breathing takes place via the mouth rather than the nose. We will study the effects of this throat lining fluid and examine ways in which treatments might help to avoid throat blockage during sleep by keeping the throat lined with non-sticky fluid. These studies will increase our understanding of OSA and help to design better treatments for the condition. People who have OSA also may develop high blood pressure associated with the nervous system response to breathing difficulties during sleep over a long period of time. In the same way as is used in the lie detector test, we will use measurements of the electrical conductivity of the skin to assess this nervous system response during sleep. These studies will help to understand how hypertension develops in OSA and who is likely to be affected. Asthma is a major health problem in Australia affecting around 20% of children and 12% of adults. Asthmatics react to inhaled pollens etc. The nose normally acts as a filter to remove many such particles from the inhaled air. If breathing takes place via the mouth more and larger particles can gain access to the lungs. We will investigate whether asthmatics breathe through their nose only or breathe through the mouth more than normal (particularly during sleep), if treatments can alter this and whether such treatments reduce the occurence of asthma attacks.Read moreRead less
While many cases of asthma are mild, severe cases require extensive health care resources and are virtually unresponsive to conventional treatment. This project will investigate whether specific compounds released from the airway are able to cause lung damage and airway abnormalities similar to that in severe asthma. We will investigate whether these changes are responsive to conventional therapy and investigate a potential treatment for regaining this responsiveness in severe asthma.
Mechanisms Of Airway Narrowing In Eosinophilic And Non-eosinophilic Asthma
Funder
National Health and Medical Research Council
Funding Amount
$500,593.00
Summary
Asthma is associated with excessive airway narrowing, increased thickness of the airway wall and inflammation, most typically with eosinophils. However, 50% of cases have few eosinophils and respond less well to current treatments. This project will examine differences in airway structure between patients with or without eosinophils, using post-mortem tissue, as part of an international research collaboration.
Mannitol In The Assessment Of Bronchial Responsiveness In Airway Disease
Funder
National Health and Medical Research Council
Funding Amount
$365,250.00
Summary
The airways of people with asthma respond by narrowing too easily and too much to a wide range of stimuli. The tests most commonly used to measure airway responsiveness in asthma are the pharmacological agents methacholine and histamine. When inhaled, they act directly on bronchial muscle causing it to contract and hence the airways to narrow. We have developed a non-pharmacological test using a dry powder of a sugar - mannitol. When inhaled, mannitol causes narrowing of the airways in asthmatic ....The airways of people with asthma respond by narrowing too easily and too much to a wide range of stimuli. The tests most commonly used to measure airway responsiveness in asthma are the pharmacological agents methacholine and histamine. When inhaled, they act directly on bronchial muscle causing it to contract and hence the airways to narrow. We have developed a non-pharmacological test using a dry powder of a sugar - mannitol. When inhaled, mannitol causes narrowing of the airways in asthmatics but little or no effect in healthy subjects. Many asthmatics respond to mannitol even when they have few symptoms of asthma. Mannitol causes the airways to narrow 'indirectly' by causing the release of substances from inflammatory cells in the airways (e.g. histamine, leukotrienes and prostaglandins) that cause the muscle to contract. After the inflammation has cleared, either by treatment with inhaled steroids or spontaneously, the response to mannitol is close to healthy subjects. Thus the response to mannitol depends on the presence of inflammation and loss of responsiveness means resolution of inflammation. The significance of this is that the mannitol test may be used as an 'inflammometer'. It would be important if airway responsiveness to mannitol could be used to identify individuals with airway diseases other than asthma, (chronic bronchitis, and chronic obstructive lung disease) who could benefit from treatment with inhaled steroids. This would be significant as there is currently no test to identify those individuals and there are unwanted effects from using steroids. Further, it may be possible to use mannitol to identify individuals with other inflammatory diseases who may be at risk of developing asthma. Some people with asthma, chronic bronchitis and chronic obstructive lung disease have increased levels of oxidative stress. We wish to identify those people and to measure change after treatment with steroids.Read moreRead less
Increased Airway Smooth Muscle Mass As An Independent Determinant Of Asthma Pathogenesis And Severity
Funder
National Health and Medical Research Council
Funding Amount
$409,966.00
Summary
Asthma is a major health burden to the community. The most common form of the disease is allergic asthma and it is thought that allergic inflammation drives associated airway abnormalities including increased airway smooth muscle (ASM) mass. This study tests a new hypothesis that airway abnormalities and allergy have separate origins but combine to produce allergic asthma, and it’s the individuals with the greatest amount of ASM who develop clinically severe asthma.