Endocrine Flashcards
Apolipoprotein expression
A = lcAt Activation B-48 = chylomicron secretion (young secretion) B-100 = LDL receptor binding (mature uptake) C = Cofactor for LPL E = rEmnatns (uptake by liver)
LCAT vs. CETP
LCAT = esterification of cholesterol (produces mature HDL) CETP = transfer of cholesterol esters to other lipoprotein particles
LPL function
Lipoprotein lipase (requires apoC cofactor)
Chylomicrons -> chylomicron remnants
VLDL -> IDL
Familial dyslipidemias (and deficiencies)
I: Hyperchylomicronemia (LPL or apoC deficiency)
II: Hypercholesterolemia (absent LDL receptor or B-100)
III: Dysbetalipoproteinemia (apoE defect)
IV: Hypertriglyceridemia (overproduction of VLDL)
Glucagonoma:
What is it?
Presentation
Tx
Tumor of a cells: glucagon production 5 D's: Dermatitis (necrolytic migratory erythemia) Diabetes (hyperglycemia) DVT Declining weight Depression
Tx: octreotide, surgery
Insulinoma
Tumor of ß cells: insulin production Whipple triad: Low blood sugar, symptomatic hypoglycemia, resolution with glucose Use C-peptide (vs exogenous insulin) MEN-1
Somatostatinoma
Tumor of delta cells: SST production, decreased other pancreatic productions
Pres: diabetes, steatorrhea, gallstones
Hormone secreting tumors of the pancreas
a cells = glucogonoma
ß cells = insulinoma
delta cells = SSToma
ZE = gastrinoma
Fabry dz Inheritance Major s/sx Deficient enzyme Accumulated substrate
XR
Peripheral neuropathy, angiokeratomas, hypohidrosis
a-galactosidase A
Ceramide trihexoside
Gaucher dz Inheritance Major s/sx Deficient enzyme Accumulated substrate
AR HSM, pancyto, osteoporosis, aseptic necrosis, bone pain Crumpled tissue paper macs Glucocerebrosidase Glucocerebroside
Niemann-Pick Inheritance Major s/sx Deficient enzyme Accumulated substrate
AR
Neurodegeneration, cherry red spot, foam cells, HSM
Sphingomyelase
Spingomyelin
Tay-Sachs Inheritance Major s/sx Deficient enzyme Accumulated substrate
AR
Neurodegeneration, cherry red spot, onion skin lysosomes, NO HSM
Hexosaminidase A
GM2 ganglioside
Krabbe Inheritance Major s/sx Deficient enzyme Accumulated substrate
AR
Peripheral neuropathy, developmental delay, optic atrophy
Galactocerebrosidase
Galactocerebroside
Metachromatic leukodystrophy Inheritance Major s/sx Deficient enzyme Accumulated substrate
AR
Central/peripheral demyelination, ataxia, dementia
Arylsulfatase A
Cerebroside sulfate
Hurler syndrome Inheritance Major s/sx Deficient enzyme Accumulated substrate
AR
DDelay, gargoylism, airway obstruction, corneal clouding, HSM
a-L-iduronidase
Heparan sulfate/dermatan sulfate
Hunter syndrome Inheritance Major s/sx Deficient enzyme Accumulated substrate
XR
Mild Hurler, aggressive, NO corneal clouding
Iduronate sulfatase
Heparan sulfate/dermatan sulfate
B1
Name
Cofactor
Deficency
Thiamine ATP: a-ketoglutrarate DH (branched chain), Transketolase, Pyr DH Wernicke-Korsakoff Dry beriberi Wet beriberi
B2
Name
Cofactor
Deficency
Riboflavin
FAD and FMN formation (succinate DH)
Cheilosis, corneal vascularization
Sucs to suck (lips)
B3 Name Cofactor Deficency Excess
Niacin
NAD+, NADP+ reactions
Glossitis, pellagra
Hartnup disease
Facial flushing (PG rxn, take aspirin)
Hyperglycemia
Hyperuriemia
B7
Name
Cofactor
Deficency
Biotin Carboxylation enzymes Pry -> OAA (pry ca) a-CoA -> malonyl-CoA (acetyl-CoA ca) propionyl-CoA -> methylmalonyl-CoA (prop-CoA ca) Dermatitis, alopecia, enteritis Abx use OR excessive raw egg whites
Lab findings in DKA
HyperK+ (putting H+ into cells)
HypoNa+ (trying to reduce volume)
Glucose up
Pseudohypoparathyroidism lab findings
End organ resistance to PTH
Low Ca, High Phos, High PTH
GNAS-1 defect -> short metacarpal/tarsal bones
Hypoketotic hypoglycemia
May look like Glycogen storage problem but:
Medium chain acyl-CoA DH deficiency
Classic hypoketotic
S/Sx: vomit, seziure, coma/lethargy, hepatomegaly
Autoimmune gastritis
Decreased acid production -> increased gastrin release
Parietal cells also decreased -> less intrinsic factor
Acanthosis nigracnas
Usually associated with T2DM
BUT rapid appearance can also be GI or lung cancer (ex. gastric adenocarcinoma)
Amyloid deposition in islet cells
Pathologic of T2DM
Exclusively ketogenic amino acids
Lysine
Leucine
Useful for supplementation in Pyruvate DH deficiency
Routes of infection for liver and bugs
Hematogenous - staph aureus
Ascending cholangitis - enterics (E. coli, klebs, enterococci
Ascending via portal system from colon (E. histolytica)
Types of diverticulum
True (all 3 layers outpouch: Meckel’s)
False (only mucosa and submucosa outpouch: Zenker)
Moldy grains could be what?
Lead to what cancer?
Aflatoxin -> aspergillus
Classic G:C to T:A mutation
Hepatocellular carcinoma
GI manifestations of CF
Obstruction (10-20%) Pancreatic dz (insufficiency, CF related diabetes) Biliary cirrhosis
Malrotation
Failure to rotate
Fibrous bands = Ladd bands
Can lead to volvulus (midgut in infants, sigmoid in elderly)
Tea colored, odorless, watery stool?
VIPoma
Alcohol vs. non-alcohol fatty liver dz: how you tell the difference?
AST>ALT in EtOH (make a toAST)
ALT>AST in non-EtOH (L = Lipids)
Lac operon components
Regulatory
Promotor - cAMP-CAP binds for induction
Operator - can be bound by protein for inhibition
How does HBV help HDV become infectious?
HBV provides surface antigen that coats HDV before it can infect hepatocytes and multiply
Th cell involvement in UC vs. Crohn’s
Crohn’s -> noncaseasting granuloma = Th1
UC -> Th2 -> damage
Ulcer burrowing through each of these means which vessel is at risk? Posterior wall duo? Lesser curvature of the antrum? Lesser curvature of the body? Greater curvature of the antrum? Greater curvature of the body? Posterior antrum/body?
Posterior duo: gastroduodenal LC antrum: right gastric LC body: left gastric GC antrum: right gastroepiploic GC body: left gastroepiploic Posterior antrum/body: splenic Fundus (if that's a thing): short gastric
Hirschsprung dz pathogenesis
Abnormal migration of NCC (which become Meissner and Auerbach plexi)
They migrate caudally, therefore rectum alway affected
3rd portion of the duo vessel relationship?
SMA
Types of polyps and malignant risk
Hyperplastic: benign
Hamartomatous: usually benign. Peutz-Jeghers assoc.
Adenomatous: Neoplastic: APC->KRAS, villous>tubular for malignancy
Serrated: premalignant, CpG hypermeth -> BRAF (saw-tooth of crypts)
D-xylose intestinal absorption
Monosacc - absorbed without any enzyme modification (can be used to test brush border integrity independent of pancreas)
Kaposi’s Sarcoma colon manifestations
Red/violet flat maculopapular lesions or hemorrhagic nodules
On biopsy: spindle shaped tumor cells with vessel proliferation
Crohn’s dz with easy brusing?
Loss of bile salts leading to inadequate absorption of ADEK
No K = bleeding
Pathogenesis of fatty liver in EtOH
EtOH leads to decreased in free fatty acid oxidation due to increased NADH production by aldehyde DH and alcohol DH
Alkaptonuria pathway
Tyrosine to Fumerate is overall pathway
Homogentisic acid dioxgenase = defective enzyme
Congenital hypothyroidism: S/Sx.
Initially no sx. -> Maternal t4
Then: lethergy, hoarse cry, poor feed, constipation, large fontanelles
Orotic acid build up +/- hyper-ammonia
Orotic acid + hyperammonemia = ornithine transcarbamaylase deficiency (urea cycle)
Orotic acid alone = uridine monophosphate synthetase (delayed growth, megaloblastic anemia)
Aromatase inhibitors
Anastrozole
Letrozole
Exemestane
Aromatase ALE
Testosterone vs DHT for sexual development
T: internal genitals, spermatogenesis, differentiation at puberty
DHT: external genitals, prostate growth, amplifies T effects
5alpha reductase deficiency
Often raised as girls until puberty when T kicks in
Genitals can range from small with hypospadus to borderline female
Incretin effect
Agents that act like incretin
Larger spike in insulin due to oral glucose over IV
GLP-1 and gastric inhibitory peptide (GIP) are hormones with incretin effects