17 Cystic Fibrosis

Genetics

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• name from fibrous cyst found in pancreas

• abnormal: sticky mucosal surfaces because not enough water

• abnormal folding: protein targeted for ubiquitin protease. Result: no protein on cell surface

• protein is made just didn't make it to the membrane

Symptoms

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• testing for recurrent infections leads to CF diagnosis

• meconium: bowel obstructions

• no bowel movement in first few days

• air fluid: when bowel obstructed, fluid backs up in obstruction, mix up with air = air fluid levels

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• no pancreatic enzymes to absorb fat

• stable for a while then develop acute exacerbation

• pseudomonas both for acute and chronic exacerbation

• clog up pancreatic duct

• recurrent pancreatitis: burn out islet cells

• vitamin E: antioxidant. Deficient leads to anemia, acanthocytosis, muscle weakness, spinocerebellar tract demylelination (ataxia). Neurologic symptoms without megaloblastic anemia

• thickened mucous can develop into polyps inside nose

Diagnosis

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• iontophoresis: electric field for test

• pilocarpine: muscarinic, parasympathetic, induce sweating (sweat induced by sympathetic but Ach NT)

• nasal potential difference: Na abnormality, not Cl abnormality

Treatment

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• dying neutrophils spill DNA, polymerized in mucous

• saline: moisten secretions

• N-acetylcysteine: cleaves disulfide bonds in mucous, but causes bronchospasm

• transplant: have to be relatively healthy (kids)

• not always done

• trypsinogen: pancreatic zymogen

• heel stick testing