lecture 5 Flashcards
what is linked to BOS?
acute rejection
what is BOS?
bronchiolitis obliterates syndrome
what is a marker for gastric aspiration?
pepsin
what can be used to measure pepsin?
slot/blot elisa
what antibodies are used in the slot/blot Elisa?
primary antibody and a secondary sheep/goat antibody which is conjugated with hydrogen peroxidase
what is added to the substrate?
DAB with hydrogen peroxidase = a colour development
is there pepsin in people who have a chronic cough?
NO
is there pepsin in people who have had a lung transplant?
YES
why is pepsin not found as much in patient with BOS?
because BOS makes the lungs leaky, therefore any gastric juice that gets in the lungs escapes from the lungs
why is there little amounts of pepsin in people that have chronic cough?
because they are aspirating buts its not getting into the lungs as the patients are coughing up the sputum instead
what conditions after lung transplantation has the most pepsin?
acute rejection
what response happens in acute rejection?
inflammatory response, CD8 lymphocytes
what happens if you limit aspiration?
lots of T lymphocytes present
what are the effects of gastric juice with a pH of 2.5?
acid of pH2.5 damages the lungs, causing destruction and fibrosis of the alveoli and interstitial spaces narrowing the airways
what is needed to improve long term survival of the lung allografts?
a more aggressive anti-reflux approach is needed early on to help reduce the development of BOS
what can help prevent the deterioration of allografts?
an antibiotic called azithromycin
what does azithromycin do?
prevents reflux by increasing gastric emptying, reducing stomach contents to reflux less easily
what can reduce azithromycoin from working?
if you have bile acids - it reduces the the survival long term and you will still get allograft deterioration
when is acid damaging?
at a pH below 3.5
how can pepsin be reactivated?
if it is trapped in the tissue, it can be reactivated by a second exposure to acid
how comes there is less pepsin in the lungs for patients who have chronic cough?
as it is coughed up before it can be let into the lungs
what is a non acid reflux event?
pH tract doesn’t not go below ph7
what can measure a non-acid reflux?
impedance
what happens every time reflux passes the rings of the pH channel?
there is a reduction in impedance, there is no drop in pH
how can you measure bile salts?
by oxidising them with the 3 alpha HSD which removes an OH group so it is oxidised and also generating NADH
how is a link assay carried out?
during oxidation you will get NADH produced and H+, then reacted with a dye to form formazan which produced a colour.
what does the amount of colour indicate?
relates to how much bile acid is present
