Path Rotation facts Flashcards
(23 cards)
Causes of SIADH
Paraneoplastic syndrome from Small Cell Carcinoma
CNS disorder / Head trauma
Pulmonary disease (pneumonia)
Drugs (cyclophosphamide)
Tennis rackets on electron microscopy
Birbeck granules
Langerhans cells (dendritic cells found in skin, derived from bone marrow, present antigen to naive T cells)
CD1a+
S100+
Review Pathoma
S100+
Schwannoma
Melanoma
Langerhans cells
hearing loss / tinnitus
S100+
bilateral involvement associated w/ neurofibromatosis type 2
Schwannoma
vomit / diarrhea / epigastric pain
uritcarial rashes on feet, buttocks, waist
Strongyloides
steroid use –> Septic Shock!
Tx: Ivermectin
Albendazole
Eosinophilic pneumonia
Loffler’s syndrome 2/2 strongyloides
Older male, steatorrhea, foamy macrophages in intestinal lamina propria
Cardiac symptoms / Arthralgias / Neurologic symptoms
PAS+
“Foamy Whipped cream in CAN”
Whipple Disease – Tropheryma whippelii
Hyperpigmented mouth, feet, hands, genitalia
Hamartomatous GI polyps
Peutz-Jeghers Syndrome
AD trait
Increased risk for Breast and GI cancers
Vitamin A
name / function / deficiency / excess
Retinol
constituents of visual pigments, essential for normal differentiation of epithelial cells into pancreatic cells and mucus-secreting cells, prevents squamous metaplasia, USED TO TREAT MEASLES & AML
Night blindness (nyctalopia); dry scaly skin (xerosis cutis); corneal degeneration (keratomalacia); Bitot spots on conjunctiva; immunosuppression
Acute toxicity - n/v, vertigo, blurred vision
Chronic toxicity - alopecia, dry skin, hepatic toxicity and enlargement, arthralgias, and pseudotumor cerebri
Teratogenic (cleft palate, cardiac abnormalities), THEREFORE A NEGATIVE PREGNANCY TEST AND TWO FORMS OF CONTRACEPTION ARE REQUIRED BEFORE ISOTRETINOIN PRESCRIBED
Vitamin B1
name / function / deficiency
Thiamine
Thiamine pyrophosphate (TPP), a cofactor for several dehydrogenase enzyme reactions:
- Pyruvate dehydrogenase (links glycolysis to TCA cycle)
- alpha-ketoglutarate dehydrogenase (TCA cycle)
- Transketolase (HMP shunt)
- Branched-chain ketoacid dehydrogenase
Impaired glucose breakdown –> ATP depletion worsened by glucose infusion; highly aerobic tissue affected first (BRAIN, HEART).
Wenicke-Korsakoff syndrome and beriberi. Seen in malnutrition and alcoholism. Diagnosis made by increase in RBC transketolase activity following B1 administration.
Vitamin B2
name / function / deficiency
Riboflavin
Components of flavins FAD and FMN, used as cofactors in redox reactions (succinate dehydrogenase reaction in TCA cycle) “FAD and FMN derived from riboFlavin (B2 = 2ATP)”
Cheilosis (inflammation of lips, scaling and fissures at the corners of the month), Corneal vascularization
“2 C’s of B2”
Vitamin B3
name / function / deficiency / excess
Niacin
Constituents of NAD and NADP (used in redox reactions). Derived from tryptophan. Synthesis requires vitamin B2 and B6. Used to treat dyslipidemia; lowers level of VLDL and raises levels of HDL
Glossitis. Severe deficiency leads to PELLAGRA, which can be caused by Hartnup disease, malignant carcinoid syndrome, and INH.
3 D’s of B3: Diarrhea, Demenita, Dermatitis
Facial flushing (induced by prostaglandin, not histamine; can avoid by taking aspirin with niacin), hyperglycemia, hyperuricemia
Hartnup Disease
AR, deficiency of neutral amino acid (tryptophan) transporters in proximal renal aminoaciduria and decrease absorption from the gut –> decrease tryptophan for conversion to niacin –> pellagra-like symptoms.
Tx: high protein diet & nicotinic acid
Vitamin B5
name / function / deficiency
Pantothenic acid
Essential component of coenzyme A and fatty acid synthesis
Dermatitis, Enteritis, Alopecia, Adrenal insufficiency
Vitamin B6
name / function / deficiency
Pyridoxine
Converted to pyridoxal phosphate (PLP), a cofactor used in transamination (AST and ALT), decarboxylation, glycogen phosphorylase. Synthesis of cystathionine, heme, niacin, histamine, and neurotransmitters including serotonin, epinephrine, norepinephrine, dopamine, and GABA.
Convulsions, hyperirritability, periperhal neuropathy (induced by INH and OCPs), sideroblastic anemias 2/2 impaired hemoglobin synthesis and iron excess.
Vitamin B12
name / function / deficiency
Biotin
Cofactor for carboxylation enzymes (add a 1-carbon group):
- Pyruvate carboxylase: pyruvate (3C) –> oxaloacetate (4C)
- Acetyl-CoA carboxylase: acetyl-CoA (2C) –> malonyl-CoA (3C)
- Propionyl-CoA carboxylase: propionyl-CoA (3C) –> methylmalonyl-CoA (4C)
Relatively rare deficiencies, Dermatitis, Alopecia, Enteritis. Caused by antibiotic use of excessive ingestion of raw egg whites
“Avidin in egg whites avidly binds biotin”
Vitamin B9
name / function / deficiency
Folate
Converted to tetrahydrofolic acid (THF), a coenzyme for 1-carbon transfer/methylation reactions. Important for the synthesis of nitrogenous bases in DNA and RNA. ABSORBED IN JEJUNUM.
Macrocytic, megaloblastic anemia; hypersegmented polymorphonuclear cells (PMNs); glossitis; NO NEURO deficits.
LABS: increased homocysteine, normal methylmalonic acid. Most common vitamin deficiency in US. Seen in alcoholism and pregnancy. Deficiency caused by Phenytoin, Sulfonamides, Methotrexate.
Vitamin B12
name / function / deficiency
Cobalamin
Cofactor for methionine synthase (transfers CH3 groups as methylcobalamin) and methylmalonyl-CoA mutase
Macrocytic, megaloblastic anemia; hypersegmented PMNs; paresthesias and subacute combined degeneration (dorsal columns, lateral corticospinal tracts, Spinocerebellar tracts) due to abnormal myelin. Associated with increased serum homocysteine and methylmalonic acid levels. Prolonged deficiency –> irreversible nerve damage.
Vitamin C
name / function / deficiency / excess
Ascorbic Acid
Antioxidant; also facilitates iron absorption by reducing it to Fe2+ state. Necessary for hydroxylation of proline and lysine in collagen synthesis. Necessary for dopamine beta-hydroxylase, which converts dopamine to NE
Scurvy - swollen gums, bruising, petechiae, hemarthrosis, anemia, poor wound healing, perifollicular and subperiosteal hemorrhages, “corkscrew” hair. Weakened immune response.
n/v/d, fatigue, calcium oxalate nephrolithiasis. Can increase risk of iron toxicity in predisposed individuals (those with transfusions, hereditary hemochromatosis)
Vitamin D
name / function / deficiency / excess
D2 = ergocalciferol - ingested from plants
D3 = cholecalciferol - consumed in milk, formed in sun-exposed skin (stratum basale)
25-OH D3 = storage form
1,25-(OH)2 D3 = calcitriol, active form
Increase intestinal absorption of calcium and phosphate, increase bone mineralization at low levels, increase bone resorption at higher levels
Rickets - in children (bone pain and deformity)
Osteomalacia - in adults (bone pain and muscle weak)
Hypocalcemic tetany
Breast fed infants should be fed oral vitamin D
Deficiency exacerbated by low sun exposure, pigmented skin, prematurity
Hypercalcemia, hypercalciuria, loss of appetite, stupor
Seen in granulomatous disease (increase activation of vitamin D by epithelioid macrophages)
Vitamin E
name / function / deficiency
Tocopherol
Tocotrienol
Antioxidant (protects RBCs and membranes from free radical damage)
Can enhance anticoagulation effects of warfarin
Hemolytic anemia, acanthocytosis, muscle weak, posterior column, spinocerebellar tract demyelination
Vitamin K
name / function / deficiency
Phytomenadione
Phylloquinone
Phytonadione
Cofactor for the gamma-carboxylation of glutamic acid residues on various proteins required for blood clotting. Synthesized by intestial flora
Neonatal hemorrhage with increased PT and PTT but normal bleeding time (neonates have sterile intestines and are unable to synthesize vitamin K). Can also occur after prolonged used of broad-spectrum antibiotics.
Zinc
function / deficiency
Mineral essential for the activity of 100+ enzymes. Important in the formation of zinc fingers (transcription factor motif).
Delayed wound healing, hypogonadism, decrease adult hair (axillary, facial, pubic), dysgeusia, anosmia, acrodermatitis enteropathica. May predispose to alcoholic cirrhosis.
