Deck 5 Flashcards
(90 cards)
0
Q
Tetrolagy of fallot results from failure of what embryologic process?
*what other 2 cyanotic heart disease arise from the same type of error?
A
- migration of neural crest cells into the truncal and bulbar ridges of the truncus arteriosus and bulbus cordis
- These would normally grow grow in a spiraling fashion to separate the aorta and pulmonary arteries
*Truncus arteriosus and TGA
1
Q
patau syndrome clinical appearance results from defect in what?
A
- Prechordal mesoderm development
* Non-disjunction in meiosis 1 is original error
2
Q
The carotid sinus’ afferent fibers run with the ______ nerve, while the aortic sinus’ afferents run with the _______ nerve. They both end up at the ________ nucleus of the ________.
A
- glossopharyngeal
- Vagus
- Solitary nucleus
- Medulla
3
Q
WHat are the specific skin findings in dermatomyositis? What about lab findings?
Pts who develop it after age 50 have incr risk of _______
A
- Grotton papules = red or violaceous, flat topped papules, often with light scale, OVER BONY PROMINENCES, usually over MCP, PIP, and DIP joints.
- Heliotrope rash = erythematous or violaceous edematous eruption on the upper eyelids and periorbital skin
Labs:
- Incr CK
- Positive ANA (antinuclear antibodies), but not specific
- Anti-Jo1 antibodies = specific!
-Over 50 = incr risk of underlying malignancy
4
Q
What is the triad in Ménière’s disease and how can you differentiate it from a CPA tumor?
A
- Tinnitus, Vertigo, Hearing loss (caused by incr volume of endolymph)
- pts often also describe a sensation of “fullness”
-It is episodic with exacerbations and remissions! Vs. CPA tumor which would be progressive and constant
5
Q
What does a carcinoid tumor look like on microscopy?
A
- Uniform shape and size of cells
- Kind of looks like a fly’s eye
6
Q
Incr solubility of a gas in the blood require ________ amounts in order to become saturated and affect the brain maximally
*High solubility = ______ blood/gas partitioning coefficient
A
- Larger
- takes longer to reach desired effect bc more gas must be administered
- incr solubility = High partitioning coefficient
7
Q
As mitral stenosis becomes more severe, the S2 to opening snap time interval becomes _______
A
Shorter!
8
Q
For each of these virion, what is their virulence ability? (what do they bind to?
A
- CMV = cellular integrins
- EBV = CD21
- HIV = CD4 and CXCR4/CCR5
- Rabies = Nicotinic AcH receptor
- Rhinovirus = ICAM-1
9
Q
Other than Flagyl and Vanc, what other drug can you use for C. Diff colitis? What are some of its properties?
A
- Fidaxomicin
- Oral, bacteriocidal, minimal systemic absorption
- used for recurrent c diff (minimal effect on colonic fluora)
10
Q
Of the HIV structural genes, which one’s product is glycosylated and cleaved in the ER? What does this create?
A
- Env
- glycosylated to gp160
- Cleaved to gp120 and gp41 —> facilitate virion absorption by target cells
11
Q
How can HepA virus be inactivated?
A
- Water chlorination
- Bleach
- Formalin
- UV irradiation
- Boiling to 85 deg for one minute
- Autoclave at 120 deg for 20 minutes
12
Q
What is the 5 –> 3 and the 3 –> 5 exonuclease activity responsible for?
A
- 5 –> 3 = removes RNA primers and damaged DNA segments
- 3 –> 5 = proofreading function that removes and replaces mismatched nucleotides on the newly formed daughter strands
13
Q
A high _____/_______ ratio in the pancreatic Beta cells results in the closure of the ________ channel, which causes insulin secretion by opening the voltage-gated calcium channels.
A
- ATP/ADP
- Potassium (KATP)
14
Q
What enzyme serves as a major glucose sensor for the pancreatic Beta cell? It’s increased activty leads to release of insulin, and it is the major rate limitor
A
-Glucokinase
15
Q
When is HCG detectable in maternal serum? why?
A
- no earlier than 6 days after ovulation (sometimes up to 11 days)
- Because successful impantation in the uterus must occur before HCG is detectable in the serum (which takes a few days)
16
Q
What is the MDR-1 gene in tumor cells, what does it produce, and what does it accomplish?
A
- Multi-drug resistance gene
- Produces P-glycoprotein, a transmembrane ATP-dependent efflux pump, normally expressed in intestinal and renal tubular epithelial cells
- functions to eliminate foreign compounds from the body
17
Q
Atheromatous plaque stability depends significantly on mechanical strength of _______. This is made primarily out of _______. Inflammatory macrophages in the intima may reduce plaque stability by secreting ________.
A
- the fibrous cap
- Made mostly of collagen
- metalloproteinases, which degrade collagen —> weaken fibrous cap
18
Q
Differentiating DIC with TTP/HUS
A
DIC:
- Bleeding
- Coag cascade involved (incr PT and PTT)
- Low fibrinogen
- high D-dimer
*All opposite for TTP/HUS
19
Q
Acute intermittent porphyria is an autosomal ________ condition, caused by deficiency of _________.
A
- Autosomal dominant
- Porphobilinogen deaminase deficiency (PBG deaminase)
20
Q
How does acute intermittent porphyria present?
What makes it worse? What makes it better?
A
- Acutely with variable GI and neurological symptoms…abd pain, vomiting, peripheral neuropathy, neuropsych derrangements
- Reddish urine —-> darkens on exposure to light and air via oxidation of excess PBG
- Worsening factors: upregulating ALA-synthase (P450 inducers, alcohol, smoking)
- Improving factors: Heme and glucose, to tx with IV heme and dextrose
21
Q
how is TPR calculated in vassels arranged in paralell?
A
1/TPR = 1/R1 + 1/R2 etc…
- Parallel = total body circulation
- Series = individual organ
22
Q
Which 2 arteries to other tissues branch off from the splenic artery? Which of these tissues is succeptible to ischemia is the splenic artery is occluded?
A
- Short gastric A. to the fundus of stomach, and Left Gastroepiploic A. to the greater curvature
- The gastric fundus, bc of poor anastamoses of short gastric artery
- L gastroepiploic has good anastamoses with R. gastroepiploic
23
Q
Gastric EROSIONS are defined as mucosal defects that do not extend through the ________
A
- Muscularis mucosa
* Gastric ULCERS penetrate mucosa and go into sub-mucosa
24
HIT is more commonly caused by _______. Treatment is ______
- Unfractionated heparin compared to LMW heparin
| - Direct thrombin inhibitors (Argatroban, Hirudin, Lepirudin)...but obviously 1st stepis to stop heparin
25
What kind of bias occurs when ther eis significant "loss to followup" which is disproportional (i.e: a greater number of one group was lost) ?
-Attrition bias, which is a form of selection bias
26
How do you define PAH, and What is the genetic cause for inherited pulmonary arterial hypertension?
- PAH defined as PA pressure > 25 mmHg
| - Abnormal BMPR-2 (bone morphogenic protein receptor type 2)....then a second insult (infection, drugs, etc ) ----> PAH
27
Other than back pain, what systems are affected in Ankylosing spondylitis?
1. MSK - Also get enthesitis...pain at insetion of muscles
2. Respiratory - enthesopathies of costochondral joints, etc...decr chest wall expansion....MONITOR THIS....rarely fibrosis of lung
3. Cardiovascular - ascending aortitis --> dilation of aortic ring with aortic insufficiency
4. Eye - anterior uveitis in 30-40% (pain, blurred vision, photophobia, conjunctival erythema)
**remember: RF is negative!!
28
All protease inhibitors have what side effects?
1. Lipodystrophy - central obesity, buffalo hump, etc
2. Hyperglycemia - from incr insulin resistance
3. Inhibition of P450 (dont use rifampin in pts of HAART...it increases P450 and thus decreases protease ......use rifabutin instead)
29
The Urachus is a remnant of the _______ that connects the ______ to the yolk sac in fetal life. Failure of the urachus to obliterate by birtch results in patent urachus, and presents with _______
- Allantois
- Bladder
- Urine discharge from the umbilicus
30
How is Attributable risk % calculated?
ARP = (risk in exposed - risk in unexposed) / risk in exposed
31
Diff in nucleotides in frameshift vs nonsense mutation?
- Frameshift = deletion of non-multiples of 3
| - Nonsense = single base substitution ---> premature stop codon
32
Graft vs host dz usually happens ______ after transplant. Most commonly affected sites are _______
- within one week
| - can affect anywhere, but most common is skin, Liver, GI tract
33
```
Each MHC class 1 molecule is composed of what 2 things?
WHat about MHC class 2?
```
- Heavy chain
- Beta-2-microglobulin
-Alpha and beta polypeptide chains
34
WHat is the histology seen in lacunar infarct areas?
- Small vessel Lipohyalinosis and atherosclerosis
| - grossly = small cavities filled with clear fluid (5-6 mm)
35
Dx for someone with fixed segmental loss of UE pain+T sensation, UE lower motor neuron signs, and/or LE upper motor neuron signs....in the setting of SCOLIOSIS?
-Syringomyelia
36
What is the mechanism of staph scalded skin syndrome?
-Exotoxin acting as protease in the superficial epidermis by cleaving desmoglein in desmosomes
37
WHat conditions are associated with carpal tunnel syndrome?
- Hypothyroid
- DM
- RA
- dialysis-associated amyloidosis
38
What is a common mutation in non-small cell lung carcinoma that results in constitutively active tyrosine kinase activity?
-EML4-ALK fusion gene
39
Integrin-mediated adhesion of cells to basement membrane and ECM involves the binding of integrins to what 3 molecules?
- Fibronectin
- Collagen
- Laminin
40
Which anti-arrythmics have been implicated with QT prolongation and torsades?
- Quinidine
- Procainamide
- Disopyramide
- ibutilide
- dofelitide
- Sotalol
41
Describe the findings seen in Pulm Silicosis
CXR:
- Nodular densities, most prominently in Apical region
- Calcified Hilar lymph nodes (eggshell)
Node sampling:
-Birefringent particles surrounded by dense collagen fibers
42
From what cells does RCC usually originate from?
| What are RCC risk factors?
- PCT
| - Smoking and obesity
43
What appetite suppressants have been shown to cause pulmonary hypertension?
- Fenfluramine
- dexFenfluramine
- phentermine
44
Which drugs for BPH work on the dynamic component of obstruction (muscular tension)? And which work on fixed component (decreasing prostate size)?
- Dynamic = alpha 1 antagonists (terazosin, tamsulosin) --> work in days to weeks
- Static = 5-a-reductase inhibitors (finasteride, dutasteride) --> can take up to 6-12 months to work
45
What drug is used to treat Hairy-cell leukemia? What class is it in, how does it work, etc?
- Cladribine
- purine analog, resistant to degradation by adenosine deaminase
- able to reach high intracellular concentrations --> incorporated into DNA and causes DNA strand breaks
- Can penetrate the CNS well, excreted in the urine
46
What structures are in the retroperitoneum?
1. major vessels - abd aorta, IVC and their branches
2. solid organs - Pancreas (except tail), kidneys, adrenals
3. Hollow organs - parts 2,3 of duodenum (part of 4 too), ascending and descending colon, rectum, ureters, bladder
4. Vertebral column and spinal muscles
47
What enzyme is relatively specific to Mast cells, and can be used as a marker of mast-cell activation?
-Tryptase
48
How is Menotropin useful in the treatment of infertility in women? WHat else is needed after menotropin administration and why?
- Menotropin acts like FSH and forms a dominant follicle
| - hCG is then needed in a large dose in order to induce an LH surge --> Ovulation
49
What is seen in the brain (at autopsy) of a child with PKU?
-pallor of the substantia nigra, locus ceruleus, and vagal nucleus dorsalis
50
What is seen on muscle biopsy in Polymyositis? WHat lab value is specific?
- inflammation, necrosis, regeneration, fibrosis of muscle fibers
- infiltration of endomysium by macrophages and CD8+ T cells
Lab: Anti-Jo-1 antibodies
51
When looking at a near object, the lens accommodates....this happens when the the ciliary muscles ______, causing ______ of the zonular fibers, allowing the lens to relax and assume a more ________ shape
- contract
- relaxation of zonular fibers
- Convex shape (lens thickening)
*with age, lens gets less elastic and ciliary muscles weaker ---> harder to see close objects
52
What segment of bowel is ALWAYS involved in Hirschsprung's disease?
- Rectum and anus
| * sigmoid is 75% of the time
53
The chemotherapeutic effect of methotrexate is overcome by _______ supplementation. This is not true for what similar drug?
- Leucovorin (N-5-formyl-THF)
| - 5-FU
54
What is the presentation of an infant with testicular feminization syndrome?
- Aka androgen insensitivity syndrome
| - 46XY infants appear to be phenotypically normal females with blind-ended vaginal pouch and no uterus
55
How do you calculate maintenance dose of a drug?
Maint dose =
(steady state plasma conc mg/L x Clearance mg/L) / Bioavailability
* for IV drugs, bioavailability can be assumed to be 1
* answer is in mg/min....so need to multiply accordingly (ex: for drug given every 3 hours.....multiply by 60 for 1 hr, then by 3)
56
What happens on a molecular level to cause Factor 5 Lieden mutation?
-Single AA substitution of glutamine for arginine near the protein C cleavage site on factor 5 gene product
57
What are treatment options for pts on anti-psychotics who develop Akithisia?
- Decrease dose of antipsychotic
| - Beta blockers or Benzos
58
Describe the steps involved in dysplastic cells eventually invading basement membrane --> carcinoma.
1. Detachment
- decr expression of adhesion molecules such as E-Cadherins
2. Adherence to Basement membrane
- incr expression of Laminin and others
3. Invasion
- secretion of proteolytic enzymes such as metalloproteinases
- also Cathepsin D protease
59
Crohn's dz inflammation is mediated mostly by ______ cells and ______ cytokines
What about UC?
Crohn's:
- Th-1 T cells
- IL-2, IFN-gamma, macrophages secrete TNF
UC:
- Th-2 T cells
- IL-4, IL-5, IL-6, IL-10
60
What are the histological findings associated with Hydronephrosis?
grossly:
- dilation and deformation of calices and renal pelvis
- atrophy and scarring or renal parenchyma and distortion of architecture
LM:
- interstitial fibrosis with patches of mononuclear infiltration
- tubular atrophy
61
- What nerve is damaged in pts with positive trendellenbug sign?
- WHat muscles are innervated by this nerve?
- What does positive trendellenburg look like?
- Superior Gluteal nerve
- Gluteus medius and minimus, tensor fascia latae (stabilize pelvis and Abduct thigh)
- Pelvis sags down on UN-affected side....patients will often lean toward affected side when walking to maintain a level pelvis
62
What is the clinical presentation of Granulomatosis with polyangitis (aka Wegner's)?
1. Pulmonary
- cough and/or hemoptysis
- focal necrotizing granulomas...sometimes coalesce into nodules and cavitate
2. Upper resp tract
- chronic sinusitis
- mucosal ulcers and/or granulomas
3. Renal disease
- RPGN (crescenteric GN)
- no immunoglobs or complement deposits...unlike Goodpastures
63
What elevated serum marker is diagnostic for Wegner's?
-c-ANCA
64
In atelectasis, the trachea deviates ________ the affected side, and in Pleural effusion the trachea deviates ________ the affected side
- Towards
| - away from
65
How do patients with familial Hyperchylomicronemia present? What is the pathology? Associated complications?
- Presents in childhood: marked hypertriglyceridemia, recurrent acute pancreatitis, and milky plasma appearance. Also eruptive xanthomas
- Autosomal recessive, LPL deficiency---> body is unable to clear dietary lipid loads due to defective hydrolysis of serum triglycerides
- No incr risk of premature CAD!! Pancreatitis
66
What is a common cause of unilateral nasal hemianopia?
-Aneurysm or atherosclerotic calcification of the internal carotid artery ---> laterally impinges on optic chiasm
67
What type of hemoglobin binds poorly with 2,3-BPG?
HgF
| -allows it to bind oxygen more avidly
68
What is the underlying mechanism of a BRAF mutation and what is the result?
What drug targets BRAF mutation?
- Valine replaced by glutamate at position 600 (V600E)
- protein kinase overactivation --> incr signaling pathway stimulus for melanocyte proliferation
-Vemurafenib
69
What should yu suspect in a pt with sore throat and fever who has Hx of Hyperthyroid?
- Rule out agranulocytosis (caused by PTU and methimazole)
| - D/c those meds and check CBC with diff
70
Why are NSAIDS an inappropriate choice for fever tx in a pt with hyperthyroid?
-They can displace thyroid hormones from binding proteins, thereby worsening thyrotoxic state
71
Clinical presentation of homocystinuria?
Supplementation with what can significantly improve outcomes?
- Marfanoid, lens dislocation, developmental delay, THROMBOEMBOLIC EPISODES
- Vitamin B6 (required cofactor for cystathionine synthetase) which turns homocysteine into cystathionine
72
How can you tell EHEC (O157:H7) in the lab compared to other strains?
- Does not ferment sorbitol
- does not produce glucoronidase
*remember: toxin is encoded by a phage
73
What do the HIV structural genes, gag, pol, and env code for?
gag- nucleocapsid proteins p24 and p7 (group specific antigens in the virion core)
pol - Reverse transcriptase, integrase, protease
env - indirectly encodes envelope glycoproteins gp120 and gp41
74
What markers are commonly seen in Small cell carcinoma of the lung?
What about non-small cell?
Small cell:
-Neurofilaments, synaptophysin, neuron-specific enolase, chromogranin
Non-small cell:
-EGF-receptors, mucin, surfactant-associated proteins
75
Do not give _______ to patients with Hyperkalemia from Digoxin toxicity.
- Calcium gluconate
| * remember: HYPOkalemia worsens Digoxin toxicity, bc digoxin competes with K+ for Na/K/ATPase
76
Most common presentation of MEN type 1 is _______
- Hypercalcemia from hyperparathyroidism
- 70% also have endocrine pancreatic tumors, usually gastrin.....but occasionally insulin or VIP
- some will have pituitary adenoma
77
In acute hepatitis B, what are some of the histologic changes seen?
- ballooning degeneration
- hepatocyte necrosis
- portal inflammation
- cytoplasm filled with spheres and tubules of HBsAg --> cytoplasm takes on FINELY GRANULAR, EOSINOPHILIC APPEARANCE
78
What are the 3 main groups of veins in early embryonic development, and what do they form?
- Umbilical = degenerate
- Vitelline = veins of the portal system
- Cardinal = systemic circulation
79
WHat is the histological appearance of Medullary thyroid cancer?
- Uniform polygonal or spindle-shaped cells
| - extracellular Amyloid deposits ---> stain with congo red
80
Other than for reducing glutathione, what else is NADPH used for?
- as an electron donor for anabolic reactions like making cholesterol, FA, steroids......also drug metabolism
- High need in liver and adrenals
81
Why do certain adenocarcinomas cause a hypercoagulable state?
-They produce a thromboplastin-like substance capable of causing chronic intravascular coagulations that are disseminated and tend to migrate
82
Injections given in the superomedial part of the buttock risk injury to the ______ nerve.
Injections in the superomedial, inferomedial, and inferolateral regions of the buttock risk injury to the ______ nerve
- Superior gluteal
| - Sciatic
83
WHich nerve provides cutaneous sensation to the posterior external auditory canal? What nerve does the rest of the ext aud. canal?
- Vagus nerve
| - Trigeminal (V3)
84
WHat is the pathophysiology involved in formation of an aortic aneurysm from syphyllis?
-Vasa vasorum endarteritis and obliteration --> inflammation, ischemia, weakening of aortic adventitia
85
In an atheromatous plaque, what provides stimulus for SM to migrate from the media into the intima and for proliferation?
- PDGF
| * released locally by platelets, endothelial cells, and macrophages
86
Which anti-epileptic can cause an exaggerated response to vasopressin?
- Carbamazapine
| - dizziness, confusion, hyponatremia
87
What gives Elastin its characteristic elastic properties? And what are the primary amino acids used for its production?
- Interchain crosslinks involving Lysine
* NO TRIPLE HELIX unlike collagen
- Non-polar AAs glycine, alanine, valine (also proline and lysine...but a lot less than collagen)
88
What is the progression of EKG changes seen in acute transmural MI?
- Peaked T waves are first sign
- ST elevations within minutes to hours
- Q-waves appear within hours to days
89
Particles entering the respiratory tract are cleared by different mechanisms based on their size....what are the size categories and how is each one removed?
- 10-15 um --> upper airway trapping
- 2.5 - 10 um --> mucociliary transport
- less than 2 um ---> reach terminal bronchiolo and alveoli --> phagocytosis by macrophages
