(L2) Clinical Relevance of Cell Membranes and Transport Flashcards
What is the cause of Niemann-Pick Disease? L2 S11 LO1
Deficiency in acid sphingomyelniase (A-SMase) Lysosomal enzyme that breaks down sphingomyelin into: -ceramide -phosphorylcholine Deficiency results in build up in lysosomes in liver, spleen, CNS, and bone marrow. Halmark cherry red spot in the eye
What are the clinical indications of Niemann-Pick disease? L2 S11 LO1
-“cherry red spot” in eye (slide 14) -hepatomegaly -spleenomegaly -neurological damage
What is the significance of the membrane asymmetry of phosphatidylserine? L2 S17 LO1
Normally found only in the inner leaflet of healthy cells. Cells undergoing apoptosis present it on the outer leaflet as a signal for phagocytes. -serves as a tag/label
How can apoptotic cells be distinguished from necrotic cells under the microscope? L2 S18
Propidium iodide can be absorbed into necrotic cells but not apoptotic cells. -can see if the cell is aoptitoic by throwing in annexin V and see if it binds to Phosphatidyl serine
What is the molecular basis of Rh typing? What is cross matching? L2 S24 LO2
Presence or absence of the D antigen. Ensure that donor blood does not react with recipient plasma.
D antigen explained
- D antigen which is inherited in an autosomal dominant fashion.
- Rh+ individuals express the D antigen and Rh-do not.
What is the molecular basis of ABO blood typing? L2 S21-22 LO2
Variable carbohydrate structure of glycoproteins/lipids of the cell membrane of RBCs.
What is the cause of spur cell anemia? L2 S30 LO3
- Elevated cholesterol levels resulting in decreased membrane fluidity and flexibility.
- Results in hemolytic anemia (RBCs lyse when passing through capillaries).
- Typically caused by liver dysfunction resulting in decreased cholesterol metabolism.
What are the cytologic indications of spur cell anemia? L2 S30 LO3
Presence of RBCs with thorny projection; acanthocytes.
What is cystinuria? What do patients present with?
Autosomal recessive, defect in transported for dimeric cystine and other dibasic AA such as argine, lysine and ornithine. Results in cystine crystals in the kidney.
-Patients present with renal cholic (abd pain that comes in waves and is linked to kidney stones).
What is Hartnup disease? L2 S35 LO4
Autosomal recessive defect in transporter for non-polar AAs (such as tryptophan) Tryptophan required for producing of serotonin, melatonin, and niacin (NAD+).
What are the clinical findings and exacerbating factors of Hartnup disease? L2 S35 LO4
-cerebellar ataxia -photodermatitis/photosensitivity.
Triggered by sunlight and fever Typically follows period of poor nutrition
What are cardiotonic drugs and what do they do? L2 S37-38 LO4
- Ouabain and digoxin
- Inhibit Na+/K+-ATPase of cardiomyocytes resulting in increase intracellular Na+ Increased Na+ impairs sodium calcium exchanger (NCX) resulting in increased Ca+ Increased Ca+ increases contractile force of cardiomyocytes
What is the clinical significance of cardiotonic drugs? L2 S38 LO4
Treatment of: -CHF -AFIB -dysrhythmias
- the drugs increase the contractile force of cardiac muscle cells and are very potent.
- sideeffects are vision disrubance, confusion, and deleirum
- it slowly reduces the resting potential of neurons to zero
How does cystic fibrosis relate to cell membranes? L2 S41-42 LO4
Autosomal recessive defect in cystic fibrosis transmembrane conductance regulator (CFTR), a Cl- active transporter. Results in increased Cl- of cells in airway creating thick mucous and leaves the airway succeptible to bacterial infections.
