Flashcards in Erythropoiesis Deck (18)
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1
What are some causes of erythrocytosis/polycythemia?
Polycythemia Vera: monoclonal prolif of RBCs, low EPO
Chronic hypoxia
Increased EPO (secondary)
EPO-secreting tumors: Potentially Really High Hct
Pheochromocytoma
Renal Cell Carcinoma
Hepatocellular Carcinoma
Hemangioblastoma
60% of Down's syndrome patients are born w/ polycythemia.
2
What causes the basophilic stippling seen in lead poisoning?
aggregates of rRNA
3
What are the features of lead poisoning?
LEAD
Lead lines gingivae, long bones
Encephalopathy
Abdominal colic and sideroblastic anemia
DRops-wrist and foot.
4
What is the treatment for lead poisoning?
1st line: EDTA
succimer for kids
Dimercaperol for severe cases in kids
5
What is:
HbA
HbA2
HbF
Hb Gower
HbA: 2alpha, 2gamma, 97% of adult hemoglobin
HbA2: 2%, 2alpha 2delta
HbF: fetal 2alpha 2 gamma (lower affinity for 2,3DPG
Hb Gower: Embryonic hemoglobin 2 zeta, 2 epsilon
6
What is:
HbBart's
HbH
HbBart's: severe alpha thalassemia. 4 gammas, no alpha
HbH: severe alpha thalassemia: 4beta, no alpha
7
What is:
HbS
HbC
HbS: Sickle cell hemoglobin, found in sickle cell patients
2alpha, 2betaS (glut-->val in beta chain)
HbC: hemoglobin C disease, seen in sickle cell patients
2alpha 2betaC (glut-->lys in beta chain)
8
What's the deal with fetal erythropoiesis?
Young Liver Synthesizes Blood
Yolk sac (3-8 wks)
Liver (6wks-->birth)
Spleen (10-28 weeks)
Bone Marrow (18 weeks-->adulthood)
9
Which bones are involved in bone marrow stuff in childhood? Adulthood?
Childhood:
Sternum
Pelvis
Ribs
Cranial Bones
Vertebrae
Long Bones
Adulthood: axial
pelvis
vertebrae
ribs
10
The first step of heme synthesis is the rate limiting step. What is the enzyme? What can inhibit this step? What is the disease associated with it?
ALA synthase
glucose and heme inhibit it
Sideroblastic Anemia (X linked)
Glycine + succinylCoa-->delta aminolevulinic acid
11
What is the second step in heme synthesis? Which enzyme? Which disease?
dAL acid-->porphobilinogen
ALA dehydratase
inhibited by lead poisoning
12
What is the 3rd step in heme synthesis? Enzyme? Disease?
porphobilinogen-->hydroxymethylbilane
Enzyme: porphobilinogen deaminase
Disease: acute intermittent porphyria
13
Which step of heme synthesis does porphyria cutaena tarda mess up?
uroporphyrinogen III-->coproporphyrinogen III
Enzyme: uroporphyrinogen decarboxylase
14
What is the last step of heme synthesis? Enzyme? Dx?
Protoporphyrin-->Heme
Enzyme: ferrochelatase
Dx: lead poisoning
15
Once again, what is the affected enzyme and accumulated substrate w/ lead poisoning?
enzyme: ALA dehydratase, ferrochelatase
accumulated substrates: d-ALA, protoporphyrin
16
What are the affected enzymes and accumulated substrates w/ acute intermittent porphyria?
affected enzymes: porphobilinogen deaminase
accumulated substrate: porphobilinogen, dALA, coporphobilinogen
17
What are the symptoms of acute intermittent porphyria and treatment?
Treatment: glucose and heme, inhibit ALA synthase
Symptoms: 5Ps
Painful abdomen
port-wine colored urine
polyneuropathy
psych disturbances
precipitated by drugs that inhibit the Cyt P450
18
