Deck 2 Flashcards
Chromosome for NF-1?
eye manifestation?
17
- Lisch nodules on iris
- also bony problems and other tumors
Enzyme defect in homocysteinuria, and brif clinical feautures?
- Cystathionine beta synthetase
- premature athero, ectopia lentis, osteoporosis, MR
Generic name for zofran? mechanism?
- odansetron
- inhibits serotonin 5-HT# receptors (located peripherally in pre-synaptic nerve terminals of Vagus nerve in GI tract)
- also located centrally in solitary nucleus tract and chemoreceptor trigger zone aka area postrema
-other options: granisetron, dolasteron
How does silicosis affect immune system?
- impairs macrophage effector arm or cell mediated immunity
- macrophages are main CMI against intracellular mycobacteria (TB)
- *mechanism: disruption of macrophage phagolysosomes by internalized silica particles
RANK receptors
- Over-expression in hypoestrogenic states –> incr bone resorption
- produced by osteoblasts
- stimulates differentiation of mature clasts
- OPG oposes it
- PTH stimulates blasts to produce RANK and colony stimulating factor
Which part of vit D synthesis does sunlight impact?
-7-dehydrocholesterol –> Cholicalciferol (D3)
- next: 25-hydroxylation occurs in liver and kidney
- last: 1-alpha hydroxylase catalyzes final step for active vitD (in kidney)
PTH effects in kidney
- increases reabsorption of Ca
- Decreases reabsorption of Phosphorus
manifestations of parasagittal brain tumor?
contralateral spastic paresis of the leg
presentation of Toxic megacolon in UC? workup?
- fever, bloody diarrhea, abd distension, abd tenderness, signs of shock
- Abd Xray for Dx
What drug class increases triglycerides as a side effects?
- Bile acid binding resins: cholestyramine, colestipol, colesevelam
- mech: decr bile rab….live ramps up bile prod, which uses LDL, so incr uptake of LDL from circulation
Recall bias
- inaccurate recall of past exposure by study participants
- usually in retrospective studies
- people with adverse event are more likely to recall a risk factor/exposure
What genes are mutated in Lynch syndrome?
MSH2 and MLH1
-defective MutS and MutL = no repair
How is protein phosphatase 1 activated? and what happens when it is activated?
- By a tyrosine kinase (like Insulin receptor)
- dephosphorylates Glycogen synthase –> activation –> Glycogen synthesis
- Dephosphorylates Fructose 1,6-bisphosphatase –> De-activation –> inhibition of gluconeogenesis
Name 3 diseases caused by impaired DNA excision repair
- Xeroderma pigmentosum
- Fanconi anemia
- Bloom syndrome
How do osteocytes communicate with each other?
Gap junctions
WHat should you be suspicious for in a patient who has had hypercalcemia (with surgically removed parathyroids), and now has bitemporal hemionopsia?
- MEN syndrome
* Parathyroid, pituitary, Check pancreas! (MEN1)
Histologically, what does SCC look like?
- Moderately differentiated
- keratin nests/pearls within or between cells
- intracellular bridging
*SCC of esophagus = smoking/drinking, betel nut chewing, foods with N-nitroso compunds
What is “MELAS”?
- Mitochondrial encephalopathy with Lactic acidosis and stroke-like episodes.
- clinically = seizure disorder, stroke like episodes, lactic acidosis, maternally inherited (HETEROPLASMY)
How does the toxin of bordetella pertussis and bacillus anthracis work?
-Both increase cAMP –> edema and phagocyte dysfunction
In granulomas of the lung, which cells surround the necrotic areas, and are large, with abundant pale and granular cytoplasm? What is their cell surface marker?
- Macrophages!
- CD-14
WHat class of anti-arrhythmic is Verapamil? WHat is it used for? How does it work?
- class IV
- Supraventricular tachyarrhythmias
- Blocks SA and AV node Calcium channels –> slows depolarization that occurs in phase 0 and the latter part of phase 4 (diastolic depolarization) —> decreases rate of SA node firing and slows AV node conduction
A diet rich in Nitrates leads to deamination of DNA bases. This is repaired by the process of _________.
The steps in this process are _________
-Base excision repair
- New deaminated weird bases recognized by GLYCOSYLASES –> cleaves them
- ENDONUCLEASE cleaves the 5’ end of the AP site
- LYASE completes the removal of sugar-phosphate group
- DNA POLYMERASE fills the gap
- LIGASE seals the gap
_______ therapy in rheeumatoid arthritis normally takes weeks to have good response, but if very effective.
________ on the other hand, has very fast acting releif, but is not used as much bc of unfavorable side effect profile. SO usually not used for short term therapy
- Methotrexate
- Steroids
What do interferon alpha and Beta do?
WHat does Interferon Gamma do?
alpha and Beta:
- Secreted by a variety of cells in response to viral infection
- act on neighboring cells (paracrine signaling)
- stimulates cells to synthesize anti-viral proteins that degrade intracellular mRNA and impair protein synthesis
Gamma:
- produced mainly by NK and T cells
- promotes TH1 cell differentiation
- induces class II MHC expression
- activates macrophages
What do V1 vasopressin receptors modulate? V2?
-V1: vasoconstriction and incr prostaglandins
V2:
- Antidiuretic response
- Medullary collecting duct is most responsive
- not only water, but also increase Urea transporters, allowing maximal osmolarity of medullary space, for maximal water escape
Ulcers on the posterior wall of the duodenal bulb are most likely to erode into what artery?
-Gastroduodenal (comes from common hepatic)
How does acyclovir/gancylovir etc.. work?
- Nucleoside analogs
- incorporate themselves into viral DNA and terminate viral DNA chain synthesis
How do cephalosporins work?
- Bind to PCB’s (penicillin binding proteins) such as transpeptidase
- Irreversibly inhibit PCBs like transpeptidase from cross-linking peptidoglycan
*resistance to cephalosporins = change in structure of PCBs, prevents binding by cephalosporins
How do organisms become resistant to Streptomycin?
Isoniazid?
Rifampin?
- Altering structure of bacterial ribosomal proteins (aminoglycosides bind to 30s subunit)
- Decrease activity of bacterial catalase-peroxidase
- Structural alteration of enzymes involved in RNA synthesis
Inhaled anesthetics _______ cerebral blood flow. THey also ______ cardiac output, BP, respiratory TV and MV, and renal function
- Increase cerebral blood flow via vasodilation (Increases ICP)
- Decrease all other things listed
Which benzos have the biggest incidence of severe drowsiness and incr risk of falls for elderly?
Longest half life ones:
- Chlordiazepoxide
- Clorazepate
- Diazepam
- Flurazepam
*Chronic Cat-naps and Damn Falls”
What are some drugs that can cause Acute interstitial nephritis? What clinical signs and labs etc do you see?
- Beta-lactams
- NSAIDS
- Sulfonamides
- Rifampin
- Diuretics
- usually a couple weeks later
- Fever, MacPap rash, oliguria
- Urine = RBCs, Eosinophils, Neutrophils…serum may show eosinophils as well
Chronic lymphedama is a risk factor for __________.
Common scenario in which this might happen?
- Angiosarcoma
- Axillary lymph node dissection in breast cancer
What are some gross pathological and histological findings in Crohn’s disease?
- Non-caseating granulomas
- Linear or serpiginous ulcerations
- fistulas
- transmural inflammatory infiltrate
- cobble-stoning
What causes Gallstone ileus and what does it present with?
- passage of a large stone (usually > 2.5 cm) through a cholecyst-enteric fistula —> Obstructio at ileo-cecal valve
- Signs and Sx of SBO + gas in gallbladder and biliary tree (bc of fistula)
Why is it thought that rheumatic fever actually occurs?
-Autoimmune reaction based on Antigenic similarity between bacterial antigens and self antigens in the heart and CNS
Where is Human placental Lactogen (hPL) secreted from? What are its effects?
-Syncytiotrophoblasts
- Increase insulin resistance
- stimulates proteolysis and lipolysis
- inhibits gluconeogenesis
*Main goal = incr glucose delivery to baby, use fats and ketones for mom
When does acute hemolytic transfusion reaction normally happen?
What are signs/Sx?
What causes it?
- within minutes to hours of transfusion
- Fever/chills, HoTN, dyspnea, chest and/or back pain , hemoglobinuria
- ABO incompatibility –> type 2 hypersensitivity –> anti-ABO antibodies (mostly IgM) –> complement activation.
Low frequency sounds are best detected at the _______ within the inner ear.
- Apex of the cochlea
- Near the helicotrema