Deck 2 Flashcards
0
Q
Chromosome for NF-1?
eye manifestation?
A
17
- Lisch nodules on iris
- also bony problems and other tumors
1
Q
Enzyme defect in homocysteinuria, and brif clinical feautures?
A
- Cystathionine beta synthetase
- premature athero, ectopia lentis, osteoporosis, MR
2
Q
Generic name for zofran? mechanism?
A
- 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
3
Q
How does silicosis affect immune system?
A
- 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
4
Q
RANK receptors
A
- 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
5
Q
Which part of vit D synthesis does sunlight impact?
A
-7-dehydrocholesterol –> Cholicalciferol (D3)
- next: 25-hydroxylation occurs in liver and kidney
- last: 1-alpha hydroxylase catalyzes final step for active vitD (in kidney)
6
Q
PTH effects in kidney
A
- increases reabsorption of Ca
- Decreases reabsorption of Phosphorus
7
Q
manifestations of parasagittal brain tumor?
A
contralateral spastic paresis of the leg
8
Q
presentation of Toxic megacolon in UC? workup?
A
- fever, bloody diarrhea, abd distension, abd tenderness, signs of shock
- Abd Xray for Dx
9
Q
What drug class increases triglycerides as a side effects?
A
- 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
10
Q
Recall bias
A
- 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
11
Q
What genes are mutated in Lynch syndrome?
A
MSH2 and MLH1
-defective MutS and MutL = no repair
12
Q
How is protein phosphatase 1 activated? and what happens when it is activated?
A
- By a tyrosine kinase (like Insulin receptor)
- dephosphorylates Glycogen synthase –> activation –> Glycogen synthesis
- Dephosphorylates Fructose 1,6-bisphosphatase –> De-activation –> inhibition of gluconeogenesis
13
Q
Name 3 diseases caused by impaired DNA excision repair
A
- Xeroderma pigmentosum
- Fanconi anemia
- Bloom syndrome
14
Q
How do osteocytes communicate with each other?
A
Gap junctions
15
Q
WHat should you be suspicious for in a patient who has had hypercalcemia (with surgically removed parathyroids), and now has bitemporal hemionopsia?
A
- MEN syndrome
* Parathyroid, pituitary, Check pancreas! (MEN1)
16
Q
Histologically, what does SCC look like?
A
- Moderately differentiated
- keratin nests/pearls within or between cells
- intracellular bridging
*SCC of esophagus = smoking/drinking, betel nut chewing, foods with N-nitroso compunds
17
Q
What is “MELAS”?
A
- Mitochondrial encephalopathy with Lactic acidosis and stroke-like episodes.
- clinically = seizure disorder, stroke like episodes, lactic acidosis, maternally inherited (HETEROPLASMY)
18
Q
How does the toxin of bordetella pertussis and bacillus anthracis work?
A
-Both increase cAMP –> edema and phagocyte dysfunction
19
Q
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?
A
- Macrophages!
- CD-14
20
Q
WHat class of anti-arrhythmic is Verapamil? WHat is it used for? How does it work?
A
- 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
21
Q
A diet rich in Nitrates leads to deamination of DNA bases. This is repaired by the process of _________.
The steps in this process are _________
A
-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
22
Q
_______ 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
A
- Methotrexate
- Steroids
23
Q
What do interferon alpha and Beta do?
WHat does Interferon Gamma do?
A
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
24
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
25
Ulcers on the posterior wall of the duodenal bulb are most likely to erode into what artery?
-Gastroduodenal (comes from common hepatic)
26
How does acyclovir/gancylovir etc.. work?
- Nucleoside analogs
| - incorporate themselves into viral DNA and terminate viral DNA chain synthesis
27
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
28
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
29
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
30
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"
31
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
32
Chronic lymphedama is a risk factor for __________.
Common scenario in which this might happen?
- Angiosarcoma
| - Axillary lymph node dissection in breast cancer
33
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
34
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)
35
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
36
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
37
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.
38
Low frequency sounds are best detected at the _______ within the inner ear.
- Apex of the cochlea
| - Near the helicotrema
39
What does Vasoactive Intestinal Peptide do? What suppresses it?
- produced by pancreatic islet cells and neurons in the GI mucosa
- relaxes GI SM, inhibits gastric acid secretion, stimulates pancreatic bicarb and Cl secretion ----> secretory diarrhea
-Somatostatin decreases production of ALL GI hormaones basically, including VIP, alleviating Sx in pts with VIPoma
40
In embryology, what parts of the pancrease come from the dorsal pancreatic bud?
What parts come from the ventral pancreatic bud?
Dorsal:
- tail
- body
- most of head
- small accessory pancreatic duct
Ventral:
- Uncinate process
- Major pancreatic duct
- inferior/posterior portion of the head
41
WHat mechanism underlies HUS?
-Microthrombi in small blood vessels following injury to endothelium by toxin (platelet activation and aggregation ---> thrombi)
42
What are some things used to treat alzheimers?
- Cholinesterase inhibitors like Donepezil (your forgetfulness is DONE!)
- Antioxidants like vit E
- NMDA rec. antagonists (memantine)
43
What characteristic of methadone allows for it to decrease incidence of withdrawal for heroin addicts?
- Long half life
| * Methadone is a very potent, long-acting opiate with good bioavailability
44
What are 2 psych meds that can cause seizure?
Name 3 antibiotics that can also cause seizure?
- Buproprion and clozapine
| - Isoniazid, cipro, imipenem
45
What drugs are MOST effective at treating hyperlipidemia? What are some other options?
-Fibrates
Others: Niacin, Statins, Omega-3 supplements
46
WHat drugs are particulary useful in pts with Atypical depression, who have failed 1st line options?
- MAOi's
| * key words for atypical depression: Mood reactivity, rejection sensitivity, INCR sleep/appetite
47
Why does Tx of 21-Hydroxylase deficiency with cortisol work?
-Supresses ACTH --> reduces stimulation of the adrenal cortex --> decreased androgens
48
What is the underlying problem in Dubin-Johnson syndrome?
What is seen as far as Sx?
Histology?
- Defect in hepatic excretion of bilirubin glucoronides across canalicular membrane
- Usually Asx....but maybe some Icterus, non-specific stuff like fatigue
- Liver is grossly BLACK, dense pigment composed of epinephrine metabolites within hepatocyte Lysosomes
49
What are some laboratory findings associated with PBC?
- **Anti-mitochondrial antibodies**
- Incr AlkP
- incr cholesterol
- incr serum IgM
- Incr bili perhaps?
50
How is colon cancer associated with IDB different than adenomatous sporadic type?
- non-polyp dysplastic lesions
- multi-focal
- EARLY p53 mutations
- LATE APC gene mutations
- Higher grade usually
51
What drug can be used for hypertensive emergencies, and causes arteriolar dilation with increase renal perfusion and natriuresis?
- Fenoldopam
* Perfect for hypertensive emergencies in pts with concurrent renal insufficiency
-1st line though for hypertensive emergencies is Nitroprusside
52
Melanocytes come from what embryologic derivitive?
- Neural crest
| * melanoma
53
Local defense against candida is mediated by ________ cells, whereas systemic infection is prevented by ________.
- T-cells
| - Neutrophils
54
Most common cause of gas gangrene? By what mechanism?
- Clostridium perfringens
| - Toxin is phospholipase --> destroys cell membranes, metabolizes sugars --> gas formation
55
How do thiazide diuretics work?
- Block Na-Cl symporters in the distal convoluted tubules
| * can cause hypercalcemia
56
How do high FFAs affect insulin sensitivity?
Increase
57
In what disease do you see low levels of serum C1 esterase? Wht drug should not be given to these patients?
- Hereditary angioedema
| - ACEi's
58
In pts with cryptochordism, what happens to seminiferous tubules?
- Atrophy and hyalinization from temperature-induced damage
- leads to decr sperm count
- decreased Inhibin levels --> incr FSH bc loss of negative feedback
59
What marker reflects activity of Osteo-BLASTS?
-Serum (bone specific) Alkaline phosphatase
60
What is 1st line Tx of acute gouty attack?
NSAIDS
*colchicine if NSAIDS are contraindicated
61
1st line tx for enterobius vermicularis? What about in pregnant patient?
- Albendazole/mebendazole
| - Pyrantel pamoate
62
Why do patients taking llong acting nitrates for CP (like isosorbide dinatrate) need to have nitrate free periods every day?
to decrease development of drug tolerance
63
What is warfarin's mech of action?
- Blocks glutamate residue carboxylation on factors 10, 9, 7, 2
* makes them innefective --> decr clotting
64
What can atropine toxicity look like? What drug is best to rapidly reverse atropine effects?
- agitation, mydriasis, tachycardia, dry and flushed skin, bronchodilation, urinary retention......if serious ---> coma and death
* in elderly = delerium/psychosis
Toxicity: Treated with PHYSOSTIGMINE
65
ANP released from atrial myocytes acts on what 3 tissues and in what way?
- Kidney --> incr Afferent artriole dilation --> incr GFR, decreases Sodium reabsorption
- Adrenal gland --> restricts aldo secretion
- Blood vessels --> relaxes vascular smooth muscles --> vasodilation
66
What is seen on histology in vegetations associated with bacterial endocarditis?
- Fibrin and platelet deposition
| * when bacteria binds --> expression of tissue factor
67
What is seen on immunofluorescence on skin samples from celiac disease patients with dermatitis herpetiformis?
-What about intestinal mucosa?
- IgA deposits in the tips of dermal papillae
| - Flattening of villi
68
What malignancy is associated with carcinogen exposue, specifically arsenic, thorotrast, and polyvinyl chloride......and expresses CD31 on its surface?
- Liver angiosarcoma
| - CD31 is PECAM-1....from endothelial cells, used for leukocyte migration through the endothelium
69
What malignancy, on histology, shows rounded and polygonal cells with abundant clear cytoplasm?
What are characteristics of this illness?
-Clear cell carcinoma of the kidney
- Metastases are usually found before primary lesion, but if present, the classic triad is flank pain, hematuria, and palpable mass.
* paraneoplastic syndromes common:
- incr EPO ---> erythrocytosis
- PTHrP ---> Hypercalcemia
70
What is c-Jun and c-Fos? how do they bind to their target?
- Nuclear transcription factors
- Directly bind DNA via a Leucine zipper motif
- Genes that code for these are proto-oncogenes
71
What do each of these do/represent with HepB infection:
- HBcAg
- HBeAg
- HBsAg
HBcAg:
- Nucleocapsid core protein
- resides within hepatocytes
- assembles virion
HBeAg:
- Marker of high infectivity
- Nucleocapsid core and precore protein
- core component within hepatocytes, assembles virion
- pre-core component directs secretion into blood
HBsAg:
- Envelope glycoprotein
- Non-infective
- forms spheres and tubules 22 nm in diameter
72
How does abnormal huntingtin protein in huntington's disease cause the actual disease?
- De-acetylation of histones
| - Silences genes necessary for neuronal survival
73
In what layer of mucosa are gastric parietal cells found? What do they stain like on histology in pernicious anemia?
- Superficial region of gastric glands
| - oxyntic (pale pink), round, platelike cells in the periphery of the upper-layer glands
74
Acetylcholine and Adenosine work on phase ______ of myocyte action potentials. What does this result in?
- phase 4
- reduction of the rate of spontaneous depolarization in pacemaker cells
- activate K+ channels, prolongs K+ flow.....keeping membrane potential negative for longer
- Inhibit L-type Calcium channels, prolobging the time taken to reach threshold
75
What defects are seen from femoral nerve neuropathy? (L2-L4)
- Weakness involving quadriceps
- possible weakening of iliopsoas
- often complain of difficulty with stairs and frequent falling 2/2 "knee buckling"
- *patellar reflex is diminished
- sensory loss = anterior and medial thigh, medial leg
76
______ increases power of a study, and can account for different p-values of 2 studies with the same relative risk result
-Sample size
77
Visual field defect is temporal lobe lesion?
-Contralateral "pie in the sky"
78
What is the diagnosis in a patient with Hx of bronchial asthma who has recurrent transient pulmonary infiltrates, CBC showing eosinophila and high IgE and IgG, and CT showing proximal bronchiectasis??
-Allergic bronchopulmonary aspergillosis (ABPA)
79
From what embryologic layer does the anterior pituitary come ffrom?
-Surface ectoderm
80
Central chemoreceptors and located in the ______ and respond primarily to _______, whereas peripheral chemoreceptors located in the ________ respond primarily to _________.
- Medulla , increased PaCO2
| - Carotid and aortic bodies , hypoxemia (low PaO2)
81
Hepatic ethanol catabolism produces high levels of ________, and inhibits _________, leading to hypoglycemia
- NADH
| - Gluconeogenesis
82
A retained dead fetus (from decision to conservatively manage) can lead to DIC.....how?
- Chronic release of tissue factor (THROMBOPLASTIN) from the placenta
- leads to overwhelming activation of intravascular coagulation cascade
- widespread deposition of fibrin and consumption of coag. factors, platelets, and eventual bleeding
83
- What are the findings of DIC?
| - What should you monitor if you're worried about someone potentially developing DIC?
Findings:
- prolonged PTT and PT
- TCP
- Microangiopathic hemolytic anemia
- Low fibrinogen
- elevated D-dimer
- Low factor 5 and 8
Monitor:
- fibrinogen
- platelet count
84
What agents can cause reperfusion arrythmias on arterial re-opening in tx of acute STEMI?
-Fibrinolytics like tPA
85
What type of vaccine is the meningiococcal vaccine? How is Neisseria mening. spread?
- Capsular polysaccharide vaccine
| - contaminated respiratory secretions or airborne droplets
86
Where is the enzyme transketolase found and what pathway is it used in?
- what co-factor does it need?
* Where is pyruvate carboxylase found?
- Cytoplasm, used for pentose-phosphate shunt
- Requires Thiamine (B1)
* Pyruvate carboxylate is found in the mitochondria
87
How can you distinguish between MAC infxn and disseminated TB?
- Marked anemia
- Hepatosplenomegaly
- Incr AlkP and LDH
* These are all possible in TB theoretically, but much more common for MAC
- MAC grows well at high temperatures (optimum = 41 deg)..unlike TB!!
88
What can be given to reverse cyanide toxicity associated withNitroprusside administration?
- Sulfur (Sodium Thiosulfate)
| * donates additional sulfur to liver rhodanase --> enhances metabolism and detoxification of cyanide to thiocyanate
89
How does ethosuximide work?
Blocks T-type calcium channels in thalamic neurons
| -causes hyperpolarization --> inhibits firing
90
What is dephenoxylate used for and how does it work?
- Anti-diarrheal (structurally similar to Meperidine)
- opiate anti-diarrheal that binds to mu opiate receptors --> slows motility
* Low dose provides effective releif without opiate-associated euphoria and dependence
* typically higher doses are combined with Atropine to discourage abuse
91
HepB replication is accomplished through a reverse transcriptase polymerase that creates intermediate _________, and who's progeny's has ________
+ RNA ss template
-Double-stranded DNA
92
Reed-Sternberg cells are characteristic (and diagnostic) for _______. and are derrived from __________.
- Hodgkin lymphoma
| - Germinal center B-lymphocytes
93
Which anticonvulsant causes elevated phenobarbital level?
Primidone
| -metabolized to phenobarbital and PEMA (phenylethylmalonamide)
94
What are the 2 most common brain neoplasms in kids? How are they different on histology?
1. Pilocytic astrocytoma
- pilocytic astrocytes
- rosenthal fibers
- *low grade
2. Medulloblastomas
- sheets of primitive, small, blue cells
- many mitotic figures
- *undifferentiated, aggressive tumors
95
Tx of Wilson's disease?
-copper chelators such as d-peniccillamine and trientine
96
What does light microscopy show in post-strep GN?
| -What labs are seen?
- Hypercellular glomerulus (q 12)
- all lobules involved
Labs:
- hematuria, proteinuria, urine RBC casts
- Low C3
- incr Anti-streptolysin O, anti-DNAase B, anti-cationic proteinase
97
What embryologic process failed in a pt with Meckel's diverticulum?
-Obliteration of the omphalomesenteric duct
