Flashcards in Heme, Iron, Blood Plasma Deck (52)
Name 2 types of congenital methemoglobinemia
Congenital - lack of NADH cyctochrome b5
Inherited hemoglobin M disease - mutation in heme pocket which stablizes ferric F3 iron.
Causes of acquired methemoglobinemia
Sulfa drugs (TMP), lidocaine, benzocaine, Dapsone
reducing agents - methylene blue or ascorbic acid
Explain the Bohr effect
Increase in pH (decrease in CO2) hemoglobin affinity increases
An increase in temperature does what to hemoglobin's oxygen binding affinity?
What is the role of bicarbonate in the transport of oxygen and CO2 between the lungs and tissues?
Tissues - CO2 converted to bicarb and H+ the H+ then binds the heme and release O2 to tissues
Lungs - H+ released from hemeglobin to bind to O2 - the H+ binds bicarbonate forming water and CO2 which is expired.
Most common deficiency in hereditery spherycytosis?
Symptoms of spheryocytosis?
splenomegaly, jaundice, secondary to hemolytic anemia. typically follows EBV or intense physical work
Treatment for spherocytosis?
1. Give vaccines for HIB, PCV, meningcocal
2. Remove spleen
3. Folic acid supplement
Difference between oncotic and hydrostatic pressure?
Hydrostatic pressure created by beating of the heart
Oncotic pressure is based on the amount of proteins in the blood
List causes of ascites
Alcoholism (cirrhois), CHF, Kwashiorkor (lack of proteins)
Also some cancers where the tumors produce fluid
Treatment for Ascites
Periscentesis - give albumin if remove more than 5 L
What is genetic heredibility of G6PD
If you have G6PD you are unable to reduce this cofactor
NADP+ to NADPH
List stressers of G6PD and what do they cause
Infection, Fava beans, drugs like antimalarials, Dapsone, and sulfa, Henna tattoos. Oxidative stress
Histologic findings for G6PD
Heinz bodies, bite cells and blister cells
Sx of G6PD
Dark urine, skin pallor, jaundice, hepatosplenamegaly, fever
What cofactor is required for Glutathione reductase to make glutathione
What pathway does G-PD enter into?
Pentose Phosphate Pathway
Why is selenium required in diet?
Allows conversion of H202 to H+ and H20
What type of anemia is associated with lead poisoning?
What enzymes does Pb2+ block in the heme synthesis pathway?
Delta- ALA - dehydratase and ferrochetalase
What is porphyria?
Inherited disorder of heme production
Name symptoms of acute porphyria
constipation, diarrhea, n/v, back, chest and neck pain, AMS, tachycardia
Diagnostic signs of acute porphyria
Increase in intermediates (porphobilinogen), increased ALA if lead poisoning
What defect in heme synthesis pathway is not a porphyria?
delta -ALA synthase deficiency (also Autosomal recessive)
Describe Cutena Tarda.
Hepatic URO-D deficiency, linked to Hep-C (acquired) - congenital is HFE C282Y homozygous
Symptoms of cutaneous porphyria
Deposits in the skin, scarring, hyperpigmention, hyper trichosis, bullous dermatosis
B6 deficiency manifests as this.
Microcytic hypochromatic anemia