Deck 1 Flashcards
Pathogenesis huntington’s disease?
Transcriptional repression from huntintin protein.
INCREASED deacetylation –> silencing of genes necessary for neuronal survival
DECREASED transcription of genes needed for neuronal survival
What are Ladd’s bands and what do they cause?
Fibrous bands between retroperitnium and R colon. Crushes duodenum and causes intestinal obstruction, bilous emesis
Caused by midgut malrotation
May have volvulus
What is the virulence mechanism for extended spectrum beta lactamase genes?
Plasmids –> conjugation
Tx carbapenems
what is MELAS?
Mitochondreal myopathy Encephalopathy Lactic Acidosis Stroke Caused by mitochondreal disorder
MOA and examples of Class I antiarrhythmic drugs?
Class I block Na+ inward current (depolarization)
Lidocaine, flacainide, procainamide
MOA and examples of Class II antiarrhythmic drugs?
B-blockers
MOA and examples of Class III antiarrhythmic drugs?
Block K+ efflux channels
used for paroxysmal afib and to maintain sinus rhythm
Prolonges repolarization
Amiodarone, dofetilide sotalol
MOA and examples of Class IV antiarrhythmic drugs?
Block L-type Ca influx channels
Slows sinus rate
Increases AV node conduction time
Where do T cells undergo + and - selection?
+ selection in thymic cortex
- selection in thymic medulla
What complication are patients at risk for with radical prostatectomies?
Erectile dysfunction
Prostatic plexus gives rise to cavernous nerves
MOA thiazides? Indications for use?
Block Na/Cl co-transporter in DCT. Increase Ca2+ reabsorption. Used in HTN + osteoporosis
MOA loops?
Block NKCC in LoH. Cause hypocalcemia
What is acute intermittent porphorya?
Autosomal dominant disease causing defective heme synthesis
PBG and ALA in urine
What is the enzyme missing in acute intermittne porphorya?
Porphobilinogen deaminase deficiency
Symptoms of Acute intermittent porphorya?
Abdo pain
neurovesicular syndrome
red urine when standing
Tx of AIP?
Intravenous heme and glucose
(ALA synthase is the rate-limiting enzyme in heme synthesis) These both inhibit heme synthesis
Why do hypothyroid pts get galactorrhea?
Lactotroph cells in hypothalamus are stimulated by TRH. Prolactin inhibits GnRH and causes amenorrhea and galactorrhea
What is contained in the hepatoduodenal ligament?
The portal triad
Hepatic artery
Portal vein
Common bile duct
Why is portal triad important?
When clamped, you can tell if bleeding is coming from one of them or from IVC/hepatic veins
What does aspergillus grow on? What is risk after infection?
Peanuts, soy, corn
Produce aflotoxin and puts you at risk for hepatocellular ca via p53 mutations
What will ACTH level be in 21-OH deficiency?
HIGH because of low cortisol levels
What type of disease is ILD?
Restrictive
What will lung volume loop look like for restrictive disease?
Shifted to R
What is expiratory flow like for ILD and why?
Increased expiratory flow due to increased radial traction (airway widening) and increased elastic recoil***
Longitudinal mucosal tears with vomiting. What is it? What causes it?
Mallory-Weiss tears caused by **increased intraabdominal pressure*
How does DDAVP work?
vWF and factor VIII increase
What are proteasome Tx for MM?
Bortezomib “boronic acid containing peptide” causing apoptosis due to accumulation of intermediates
What does Thyroid Peroxidase do in gland?
*Iodination of thyroglobulin, *coupling of iodized tyrosine, and *oxidation of iodid
What determines blood flow to heart? (main factor)
Duration of diastole
What are segmented viruses? What is significance of them being segmented?
Can undergo reassortment and antigenic shift/drift Rotavirus Reovirus Orthomyxovirus Arenavirus Bunyavirus
MOA ethosuxamide?
Decrease Ca2+ channels in thalamus
What are the antiepileptics blocking Na+?
Valproic acid, carbamazepine, phenytoin
How do you get silicosis?
Industrial exposure to coal and sand
What do you see on histology of silicosis?
Collangeous nodues with dust laden macrophages. Interstitial collagen deposition
Round nodules in upper lobes w eggshel calcifications
MOA colchicine?
Inhibit Microtubular polymerization
Inhibit phagocytosis, chemotaxis, degeneration
Used in pts who can’t take NSAIDS
What enzyme deficiency causes SCID?
Adenosine deaminase deficiency (lymphotoxicity)
What is the MOA for mycophenolate and ribavirin?
Inhibit IMP dehydrogenase (inosine mono phosphate dehydrogenase). Inhibits purine synthesis in T cells and
What is caused by HGPRT deficiency?
Lesh Nyhan. Increased Uric Acid production
Why can’t you give 6-mercaptopurine and azothioprine together?
6 mercaptopurine binds PRPP in purine pathway and causes T-cell toxicity. It’s metabolized by xanthine oxidase so you can’t give azothioprine unless clinically indicated
What two factors are needed to grow H influenzae?
NAD+ and hematin (Factors V and X). H influenzae will grow if plated with staph because it has NAD+
Infant with large fontanelle, protruding tongue, umbilical hernia, dry skin, jaundice. What is it?
Congenital hypothyroidism
Danger of congenital hypothyroidism?
Permanent intellectual disability
What are brain changes in Huntington’s Disease? What receptors are activated?
Degeneration of caudate nuclus and putamen. Binding NMDA receptors bind glutamate and cause neuronal death
What are stages of lobar pneumonia and what cells are involved?
Congestion - pronteinateous fluid and leaky cappilaries
Red hepatization - liver like, neutrophils, fibrin, erythrocytes
Grey hepatization - macrophages
Resolution - macrophages
Embryology of the pancreas?
Ventral and dorsal buds fuse at 8 weeks
Ventral becomes part of head and main duct
Dorsal becomes everything else (majority – superior head, body, tail) + accessory duct
What is FMD?
Non-atherosclerotic disease affecting arteries. Fibromuscular webs & aneurysms
*Absent internal elastic lamina
String-on-bead appearances
Affects cerebrovasculature and kidneys. RAS and aneurysms
MOA arsenic poisoning? Where is it found?
Inhibits cellular respiration, gluconeogenesis, and glutathione metabolism
Binds to sulfhydryl groups
Found in insecticides & contaminated water
Presentation arsenic poisoning?
**severe watery diarrhea
Garlic breath
Hypotension
Chronic: hyperkeratosis, abnormal pigmentation, glove in stocking neuropathy
Tx arsenic poisoning?
Dimercaprol inhibits arsenic binding sulfhydryl groups
How does methyltestosterone (androgen steroids) cause comedomal acne?
Excessive follicular epidermal hyperproliferation and sebum production
What medications cause tardive dyskinesia?
Dopamine antagonists
Antipsychotics, metclopramide
Benefits and risks of selective COX 2 inhibitors?
Benefits: anti-inflammatory effects, less bleeding risk, no gastric uceration
Risks: Increased thrombotic and cardiovascular events due to inhibition of prostacyclins (vasodilators and antigoagulant)
Test for sickle cell trait?
Hb electrophoresis
SE doxorubicin?
Dilated cardiomyopathy
MOA Anthracyclines?
Anthracyclines (doxorubicin, donorubicin) bin Topoisomerase II and create structures that break DNA. Also create free radicals and iron-complexes that cause cardiotoxicity
What agent should be administered along with doxorubicin?
Dexrazoxane- chelating agent blocking the formation of iron-containing complexes and binding of topoisomerase II in healthy cardiac myocytes.
Which substances cause gastric acid secretion in parietal cells?
Histamine, Ach, gastrin
What is systemic mastocytosis?
Mast cell degranulation resulting from KIT receptor tyorsine kinase mutations.
Urticaria, puritis, hypotension, flushing, increased gastric acid secretion from histamine release**
What is zenker diverticulum caused by?
Cricopharyngeal motor dysfunction and oropharyngeal dysphagia
What does activation of muscurinic receptors do?
Vasodilation by production of NO, smooth muscle relaxation
Also detreusor muscle contraction, increased parystalsis, pupillary constriction
MOA muscurinic receptors causing smooth muscle relaxation?
increase in cGMP causing myosin light chain to activate phosphatase–> inhibits myosin and actin from binding
What are integrins? What do they bind?
Transmembrane receptors that bind extracellular matrix or other cells. Fibronectin, collagen, laminin. Gets downregulated in melanoma
What are effects of glucocorticoids on liver?
Increased gluconeogenesis and glycogenesis. Insulin antagonism –> hyperglycemia
How does acoustic neuroma present?
Unilateral hearing loss + tinnitus
Where does food aspirate when supine vs standing?
Supine- posterior segments of upper lobes, superior segments of lower lobes
Standing- basilar segments of lower lobes
“Swallow a bite, goes down the right”
Which rib overlies R kidney?
12th rib
What is Type I error? What is alpha?
Type I error is when researchers fail to accept the null hypothesis when the null is really true
Alpha = percent chance that the researchers are willing to risk Type I error. Set at 0.05 like p
What is Type II error? What is Beta?
Type II error = researchers fail to reject the null hypothesis even though the null is truly false.
Beta = chance of making a Type II error.
What is 1-beta in statistics?
Statistical Power = study’s ability to detect a difference when it exists. Probability of rejecting the null when it is truly fase (finding a true relationship). Depends on sample size and difference in outcome between groups being tested
How does latanoprost work?
Glaucoma med. Prostaglandin analogue– increases uveoscleral and aqueous humor outflow
How does dorzolamide work?
Glaucoma med, CA inhibitor. Decreases bicarb production in ciliary body and decreases acqueous production
How is Ca2+ removed from cell in the final stage of myocyte contraction?
Via Na/Ca+ exchanger and Ca+ ATPase. Brings the Ca back to SR or out of cell
What part of the brain produces norepinephrine? What does this part of the brain do?
Locus cerulius- Posterior rostral pons near floor of 4th ventricle
Responsible for sleep, arousal, consciousness (reticular activating system), cognition, BP control
How does digoxin work?
Inhibits Na/K ATPase. Inhibits Na efflux and inhibits Ca efflux
What shows on histology with HIV dementia?
Microglial nodules with multinucleated giant cells
Where does isotype switching occur?
Germinal centers, must activate CD40
What is primary and secondary immune response from B cells?
IgM, then isotype switching, then secondary response is IgG
Who gets Giardia infections?
People with IgA deficiency
What are symptoms of IgA deficiency?
Recurrent sinopulmonary infections, GI infections (Giardia), coeliac disease, anaphylactic blood transfusion reaction,
How does HIV-2 present?
Longer asymptomatic periods, labs won’t show HIV-1 viral levels even when symptomatic, lower levels of viremia
Endemic to West Africa (senegal)
