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54 Cards in this Set
- Front
- Back
What is AFP? What is its significance diagnostically?
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α-Fetoprotein:
Glycoprotein ~ like a fetal albumin; Binds = Ni, Cu, FA's & bilirubin Dx tool for pregnancy: - ↑ AFP = Neural tube defects & omphalocele - ↓ AFP = Down syndrome Dx tool in children: - ↑ AFP = Ataxia-telangiectasia (8 months) Dx tool in adults: - ↑ AFP = HCC & Mets, Germ cell tumors |
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X-Linked Immunodeficiencies?
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WBC
W- Wiskott-Aldrich B- Bruton's agammaglobulinemia C- Chronic granulomatous disease |
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What are the X-Linked Recessive Disorders?
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1) Immunodeficiencies (WBC's)
- W - Wiskott-Aldrich - B - Bruton's Agammaglobulinemia 2) Lysosomal Storage: - Fabry's (sphingo) - Hunter's (mucopolysacc) 3) Enzyme deficiencies: - G6PD-deficiency - Lesch-Nyhan (HGPRT) 4) Muscular dystrophy (dystrophin) - Duchenne's (delete) - Becker's (mutation) 5) Hemophilia - A - F VIII - B - F IX 6) Ocular albinism 7) Fragile X |
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What recurrent infections are people w/ CF prone to?
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Pseudomonas
Staph aureus NOTE: this is the case where you would use fluoroquinolones in kids (d/t pseudomonas risk) |
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What is Duchenne's muscular dystrophy?
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an XLR dz caused by frameshift mutation that deletes the dystrophin gene (DMD).
Results in accelerated muscle breakdown (pelvic girdle first --> superiorly). |
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What are the signs of Duchenne's muscular dystrophy?
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1) Muscle weakness (beginning @ pelvic girdle and moving superiorly)
2) Labs = ↑CPK 3) Gower's maneuver - using hands to stand up 4) Pseudohypertrophy of calf muscles (pseudo- d/t fibrofatty replacement of muscle) 5) Usually young (onset b4 5 y/o) |
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What is Becker's muscular dystrophy?
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X-Linked recessive mutation of the dystrophin gene.
Less severe disease than duchenne's and later onset (adolescence --> adulthood) |
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What is Fragile X syndrome and what does it cause?
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X-Linked recessive disease affecting the FMR1 gene.
It is a Trinucleotide repeat disorder (CGG). Findings: 1) X-tra large: - testes - jaw - ears 2) MR - autism 3) MVP |
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What is the FMR Protein?
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Coded by FMR1 gene, affected in Fragile X Syndrome.
1) Is a cytoplasmic protein found in: - Brain → MR - Tetes → macroorchidism 2) Involved in mRNA translation in: - axons - dendrites |
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What is the cause of 95% of cases of Down syndrome?
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Meiotic nondisjunction of homologous chromosomes
(a/w advanced maternal age) |
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What condition would be associated with an ↓AFP, ↑hCG, ↓E3, ↑inhibin A?
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Down syndrome
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What condition would be a/w ↑ nuchal translucency?
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Down syndrome
Turner syndrome |
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What condition would be associated with ↓AFP, ↓HCG, ↓E3 and normal inhibin A?
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Edward's syndrome
Trisomy 18 |
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What chromosomes are particularly involved in robertsonian translocation?
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13, 14, 15
21, 22 |
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What condition is a/w high pitched crying and mewing?
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Cri-du-chat syndrome
Microdeletion of short arm of chromosome 5 (5p-) Also a/w: - microcephaly - moderate → severe MR - epicanthal folds - cardiac (VSD) |
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What is William's syndrome?
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Microdeletion of long arm of chromosome 7 (elastin gene)
a/w: - Elfin facies - MR - Hypercalcemia (sens. to VitD) - Extreme friendliness to strangers - CV problems think Will Ferrel in Elf |
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What are the presentations of 22q11 deletion syndromes?
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CATCH-22 (3,4)
C - Cleft palate (2º palate) A - Abnormal facies T - Thymic aplasia C - Cardiac defects H - Hypocalcemia (2º d/t parathyroid aplasia) |
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What are examples of 22q11 deletion syndromes?
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DiGeorge syndrome
Velocardiofacial syndrome |
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What is the rate-limiting enzyme of glycolysis?
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PFK1 = phosphofructokinase-1
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What is the rate-limiting enzyme of gluconeogenesis?
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F16BP = fructose-1,6-bisphosphatase
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What is the rate-limiting enzyme of TCA cycle?
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Isocitrate dehydrogenase
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What is the rate-limiting enzyme of glycogen synthesis?
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Glycogen synthase
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What is the rate-limiting enzyme of glycogenolysis?
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Glycogen phophorylase
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What is the rate-limiting enzyme of the HMP shunt?
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G6PD = glucose-6-phosphate dehydrogenase
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What is the rate-limiting enzyme of de novo pyrimidine synthesis?
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CPS II = carbamoyl phosphate synthetase II
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What is the rate-limiting enzyme of de novo purine synthesis?
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Glutamine-PRPP amidotransferase
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What is the rate-limiting enzyme of the Urea cycle?
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CPS I = carbamoyld phosphate synthetase I
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What is the rate-limiting enzyme of fatty acid synthesis?
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ACC = acetyl-coA carboxylase
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What is the rate-limiting enzyme of fatty acid oxidation?
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CAT I = carnitine acyltransferase I
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What is the rate-limiting enzyme of ketogenesis?
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HMG-CoA synthase
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What is the rate-limiting enzyme of cholesterol synthesis?
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HMG-CoA reductase
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What is the difference between glucokinase and hexokinase?
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Hexokinase is ubiquitous
- high affinity (low Km) BUT - low capacity (low Vm) - negative f/b from its product (G6P) Glucokinase in liver & ßCells - low affinity (high Km) - high capacity (high Vm) - allows liver to be glucose "buffer" and store excesses |
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What is the activated carrier for methyl groups?
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SAM = s-adenosyl methionine
ATP + methionine → SAM SAM transfers methyl units for anabolic pathways: - phophocreatine - NE → EPI leaves homocysteine which is regenerated to methionine by: - B12 - THF |
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What is the main function of biotin?
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To act as a cofactor for carboxylation enzymes (adding C from CO2)
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What steps in glycolysis require ATP?
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1) Hexokinase/glucokinase
2) Phophofructokinase-1 (rate limiting step) |
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What steps in glycolysis generate ATP?
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1) Phosphoglycerate kinase
2) Pyruvate kinase 3) Pyruvate dehydrogenase |
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What stimulates/inhibits PFK-1?
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Stimulates:
- AMP - F2,6BP Inhibits: - ATP - Citrate |
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What stimulates/inhibits Pyruvate kinase?
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Stimulates:
- F16BP Inhibits: - ATP - Alanine |
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What is the effect on F26BP in the fasting state?
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Fasting → ↑PKA → ↑ FBP2
This converts F26BP back to F6P and removes stimulation of PFK-1; therefore there is less glycolysis |
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What is the effect on F26BP in the fed state?
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Fed state → ↓PKA → ↑PFK-2
This generates more F26BP which in turn upregulates PFK-1 and there is more glycolysis |
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How does PKA affect glycolysis?
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PKA is either stimulated by cAMP (d/t ↑glucagon) or inactivated by low cAMP (↑insulin).
When active, PKA phophorylates the PFK2/FBP2 complex. Phosphorylation activates FBP2 -> converts F26BP to F6P |
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What are the irreversible enzymes of gluconeogenesis, their location in the cell, and any cofactors?
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1) Pyruvate carboxylase
- mitochondria - biotin + ATP 2) PEP carboxkinase - cytosol - GTP 3) Fructose-1,6-bisphosphatase - cytosol - RATE LIMITING STEP 4) Glucose-6-phosphatase - ER - (deficiency = von Gierke's dz) |
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What is von Gierke's disease?
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A deficiency in Glucose-6-phosphatase.
This prevents the final step of gluconeogenesis (the "liver acts like a muscle" b/c it lacks this crucial enzyme) |
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What are the glycogen storage diseases?
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Very Poor Carbohydrate Metabolism
V - Von Gierke's P - Pompe's C - Cori's M - McArdle's |
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What are the four fates of pyruvate?
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1) Alanine shuttle (ALT)
2) Gluconeogenesis (Pyruvate carboxylase & PEP carboxykinase) 3) TCA (PDH = pyruvate dehydrogenase) 4) Lactate (LDH) |
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What are the cofactors of the Pyruvate dehydrogenase complex?
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TLC For No-one:
T - Thiamine (B1) L - Lipoic acid C - CoA (B5) F - FAD (B2) N - NAD (B3) NOTE: same cofactors as α-ketogluterate dehydrogenase complex |
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What are the major enzymes of the TCA?
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1) PDH = pyruvate dh (3C → 2C)
2) IDH = isocitrate dh (6C → 5C) 3) αDH = α-Ketoglutarate dh (5C → 4C) NOTE: all generate CO2 & NADH |
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What does each turn of the TCA generate (per pyruvate)?
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Pyr → A-CoA:
- 1 x CO2 - 1 x NADH TCA cycle: - 2 x CO2 - 3 x NADH - 1 x FADH2 - 1 x GTP - 12 x ATP |
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What are the results and treatment of pyruvate dehydrogenase deficiency?
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Lactic acidosis (and buildup of pyruvate)
Findings = neurological defects Tx = ↑ ketogenic nutrients - high fat - lysine - leucine Causes can be d/t B1 (thiamine deficiency) d/t: - nutritional - EtOH addiction |
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What are pathology signs of G6PD deficiency?
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Heinz bodies = oxidized Hb
Bite cells = phagocytized removal of heinz bodies in spleen by macrophages |
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What does G6PD do?
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Generates NADPH (reduces NADP+) which is used to regenerate oxidized glutathione that can convert H2O2 → H2O
(prevent oxidative damage) |
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What are the drugs that can cause hemolytic anemia in someone w/ G6PD deficiency?
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Hemolysis IS PAIN:
I - INH S - Sulfonamides P - Primaquine A - ASA I - Ibuprofen N - Nitrofurantoin (abx) also: Fava beans and anti-TB's |
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What are the symptoms of fructose inctolerance? What is the cause?
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Symptoms:
- Cirrhosis - Jaundice - Hypoglylcemia - Vomiting d/t Aldolase B deficiency (FAB GUT) |
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What are the symptoms of galactosemia? What is the cause?
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Symptoms:
- FTT (failure to thrive) - Hepatomegaly - Jaundice - MR - Cataracts (infantile) d/t Uridyl-Transferase deficiency (FAB GUT) |