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32 Cards in this Set
- Front
- Back
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what kind of genetic disease is CF?
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autosomal recessive
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what happens to the mucous in this mutation?
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more viscous mucas
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prevalence;
-caucasian -asian |
1 in 25 caucasian carriers and 1 in 2500 born with
asians are 1/10th of this |
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mutation on what chromosome?
codes for what protein and what does this protein normally do? |
long arm of chromosome 7
codes for transmembrane regulator protein (CFTR) which is a chloride channel |
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most common mutation of CF?
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ΔF508, and accounts for 80% of cases
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what does the CFTR chloride channel normally do on mucosal surfaces?
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allows chloride ions out of the cell in the presence of cAMP, and into the lumen (e.g. of the airway or pancreas)
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CF will result when CFTR activity is less than __% of normal
and what is a less severe form of CF? |
3%
pancreatic sufficient CF (occurs when CFTR activity is 3-8% of normal) |
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without activity of CFTR chloride channels, what is re-absorbed into the cells from the fluid of the lumen?
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sodium
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re-absorbed sodium from lumen to cell causes what?
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reduced excretion of water from cells
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the viscous mucous plugs what in the pancreas?
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the exocrine ducts
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CFTR channels play a different role in the sweat glands, what is this?
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they allow reabsorption of chloride ions from the sweat
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clinical presentation of a child aged 0-2
(3) |
Recurrent Infections
Large offensive stools Failure to thrive |
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what is given for the prevention of liver impairment in CF patients?
__% of adolescents with CF will develop liver complications |
Ursodeoxycholic acid (UDCA)..(reduces cholestasis and aid bile acid reabsoprtion, which helps increase liver function in CF patients)
20% |
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when is Ursodeoxycholic acid (UDCA) also used?
(outside of CF) |
Ursodeoxycholic acid is sometimes used in primary biliary sclerosis and gallstones as it alters the metabolism of cholesterol and micelles, and makes them break down more readily
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(in newborns)
what is the nature of the mucas and what infections are most likely? (recurrent chest infections) (3) |
The nature of the mucous (thick, not easily passed up the mucociliary escalator, thus there is stasis of mucus) predisposes to chronic infection with organisms such as S Auerus and H influenzae, and later in life Psuedomonas Aeruginosa
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chronic infections combined with the chronic inflammatory state, causes b_________ and a_____ f________
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bronchiectasis and abscess formation
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what is bronchiectasis?
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localized, irreversible dilation of part of the bronchial tree caused by destruction of the muscle and elastic tissue
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what is meconium?
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-substance that is present in the intestine at birth
-dark, sticky and odorless, and has an appearance like tar -it is made of bile, intestinal cells, water, amniotic fluid and has a high concentration of mucous |
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what normally happens to meconium after birth?
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pancreatic enzymes act on the meconium, and it is passed in the stools
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what happens in meconium ileus?
(happens in 10-20% of CF newborns) |
-meconium is not broken down by the pancreatic enzymes due to pancreatic insufficiency
-as a result, it may cause obstruction |
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how is meconium ileus treated?
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Gastrografin enema, or oral N-acetylcysteine,but in many cases will require surgery
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symptoms in age 0-2 (aswell as newborn symptoms of recurrent infections and meconium ileus)
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-extended period of neonatal jaundice
-steatorrhoea |
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what is steatorrhoea?
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-presence of excess fat in feces
-stools may also float due to excess lipid -have an oily appearance -especially foul-smelling |
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what is cyanosis?
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-appearance of a blue or purple coloration of the skin or mucous membranes
-due to the tissues near the skin surface being low on oxygen |
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link between CF and infertility?
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-only in males
-due to lack of vas deferens -men can still father children via intracytoplasmic sperm injection |
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what is Intracytoplasmic sperm injection (ICSI)?
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-in vitro fertilization procedure in which a single sperm is injected directly into an egg
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how does CF lead to plugging of pancreatic ductules?and what is implication of this for cells of pancreas?
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-in CF pancreatic secretions are rich in mucous and protein
-this means they are particularly viscous, and can form plugs in the pancreatic ductules -this then allows the enzymes to act on the pancreatic acinar cells, eventually destroying them |
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what are Inspiratory crepitations?
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crackling heard on inspiration
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what are Mucolyitcs, eg DNases?
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-products that break down DNA found in the sputum as a result of severe breakup of inflammatory cells
-can help to make the mucus less viscous |
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what is commonly nebulised in CF? especially in asthmatic symptoms?
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nebulised saline
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low levels of ______ in the faeces is diagnostic for pancreatic insufficiency
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elastase
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what is Guthrie test?
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-if Immunoreactive Trypsin (IRT) is raised in CF babies
-if this test is positive, the babies are screened for common CF mutations |
