lecture 3 Flashcards
how many isoforms does carbonic anhydrase have?
- 11
why is carbonic anhydrase important?
- generates bicarbonate
- allows protection of tissues
when is carbonic anhydrase III expression increased?
- in gastrooesophageal reflux disease
- increased in inflamed mucosa
- moves to cells lower in mucosa to form a barrier
what disease completely loses carbonic anhydrase III?
- LPR
where is the 20 minute acid exposure shown?
- in larynx (pH2 has greatest effect)
- has no effect on oesophagus
what happens when pig oesophagus is treated with both acid and pepsin?
- becomes damaged
- less expression at more acidic pHs
- oesophagus expression recovers if incubation at pH 7.4 (recoverable reduction)
what happens when pig larynx is treated with acid and pepsin?
- doesn’t recover
- damage with both
- decreases CA III expression permanently
what mucus is expressed in the larynx?
- MUC 4 (membrane bound mucin) - MUC5AC (gel forming surface mucin)
what mucus is expressed in LPR?
- expression of MUC 5AC is lost
what does this show MUC 5AC to have a role in?
- protection
what is OME?
- otitis media with effusion (glue ear)
what is OME thought to be due to?
- respiratory viruses
- allergy
- Eustachian tube obstruction
- bacterial infections
- dysfunctional mucocilliary clearance
what is OME actually caused because of?
- reflux of gastric juice
what were the results from the effusions tested?
- acidic protease activity found in 19/65
- 59/65 contained pepsin or pepsinogen protein
what pH does pepsin damage tissues at?
- high pHs
what was concluded from this experiment?
- 91% effusions contain pepsin/pepsinogen so source certainly gastric juice
- gastric reflux may be primary factor in OME
- reflux instigates cascade of inflammatory events
why are they called allografts?
- not perfectly matched to the patient
what lung conditions are applicable for lung transplants?
- emphysema
- idiopathic pulmonary fibrosis (destruction of lungs, fibrous tissue forming instead)
- cystic fibrosis
what is the survival rate 1 year post transplant?
- 80%
what is the mortality rate?
- 50%
- due to allograft failure
- epithelial damage and scarring occurs
how does bronchiolitis obliterates syndrome (BOS) improve years after transplant?
- with anti-reflux surgery at same time shows cured from BOS
- rest lead to deterioration of lungs
- patients with no history of reflux also have low survival rate after BOS surgery
how do you prevent reflux?
- fondoplication
what occurs in fondoplication?
- fundus of stomach wrapped around bottom of oesophagus
- strengthens cardiac sphincter
- reduces chance of reflux
- protection of lungs
what does BOS result from?
- fibrosis
- lots of inflammatory cells and collagen
- no room for air to pass through
- loses airway ability to exchange gases
- loss of FEV1 (forced expiratory volume) over time