UWorld Practice Questions #5 Flashcards
What nerve and muscles are affected when a pt has a Trendelenburg gait?
Contralateral (to the side of hip drop) superior gluteal nerve impacting glut medius and glut minimus.
Injection into what area of the buttock risk superior gluteal nerve injury?
Injections into the superior-medial quadrant.
Of HbA, HbS and HbC, what is the order of speed w/ which they migrate on hemoglobin electrophoresis?
HbA migrates fastest b/c it’s the most negative. HbS migrates less quickly b/c it replaced a negative w/ a neutral charge. HbC migrates the slowest b/c it has a missense mutation that replaces a negative charge w/ a positive one.
In which bipolar disorder are depressive episodes required for dx?
Bipolar II. They may also occur in bipolar I (the one w/ frank mania) but are not required.
What is cyclothymic disorder?
2+ years of fluctuating mild hypomanic and depressive sxs that do not meet criteria for hypomanic or major depressive disorder.
What does Legionella traditionally contaminate?
Natural bodies of water, municipal water supplies, and water based cooling systems –> these can be sources of outbreak.
At the level of the true pelvis, the ureter cross the internal iliac artery just _______ to it?
Passes just anterior to the internal iliac artery.
What structure contains the ovarian vessels?
The suspensory ligament of the ovary
How do integrins and fibronectins work in terms of extracellular matrix stuff?
Integrins are transmembrane proteins that can bind to different proteins in the ECM like collagen, laminin and fibronectin.
Fibronectins bind to integrins, collagen and glycosaminoglycans serving to mediate cell adhesion and migration.
True or false, alcoholic macrocytosis can occur independent of folate/B12 deficiency?
True!
Mutations to filaggrin are linked to what skin disease?
Atopic dermatitis
When does dermatitis herpetiformis typically present in life?
Usually in the 4th or 5th decade. It is uncommon in childhood.
Why isn’t there necrosis and scarring distal to an un-ruptured atherosclerotic occlusion?
Because these develop slowly over time and allow time for collateral vessels to develop and perfuse the hypoperfused area that is distal to the occlusion.
What are conditions that make atherosclerotic plaques less stable and thus more prone to rupture?
Thin fibrous cap, rich lipid core, and active inflammation in the atheroma.
Ulcers found beyond the duodenal bulb suggest what?
Zollinger-Elison Syndrome
What does a gastrin level that rises in response to secretin indicate?
Zolinger-Elison syndrome. This is because normally secretin inhibits gastrin secretion but in ZES it will paradoxically stimulate secretion from gastrinomas.
What are the characteristics of lateral medullary syndrome (aka Wallenberg syndrome) and what is the deficit causing it?
- vertigo/nystagmus –> vestibular nucleus
- ipsilateral cerebellar signs –> inferior cerebellar peduncle
- Loss of pain/temp in ipsalateral face and contralateral body –> spinal trigeminal nucleus and spinothalamic tract
- bulbar weakness (dysphagia, dystonia) –> nucleus ambiguuus
- Horner syndrome –> sympathetic fibers going to head
What malignancy are pts w/ PCOS at risk of?
Endometrial hyperplasia and endometrial adenocarcinoma (all that unopposed estrogen as there is decreased progesterone in PCOS).
What is vaginal adenosis and what is it a precursor/risk for?
It is persistance of the glandular columnar epithelium in the vagina and is a precursor for clear cell adenocarcinoma of the vagina.
What cardiac defect are Berry aneurysms associated with?
Coarctation of the aorta (if coarctation exists, these aneurysms are more prone to rupture!)
What is menotropin and how is it used?
Menotropin is human menopausal gonadotropin. It is functionally similar to FSH and is used to encourage the development of a dominant follicle during assisted fertility/reproduction.
Disorganized lamellar bone in a mosiac pattern is consistent with what?
Paget disease of the bone
What are the bone changes seen in hyperparathyroidism?
Subperiosteal thinning appearing as subperiosteal erosions, and osteolytic cysts in long bones. –> this is all called osteitis fibrosa cystica.
When is osteoid matrix accumulation around trabeculae seen?
Vitamin D deficiency
What is trabecular thinning with fewer interconnections characteristic of?
Osteoporosis.
Why is dextrose administration an effective tx for acute intermittent porphyria?
Because tx and prevention are based on inhibiting ALA synthase and thus preventing the accumulation of toxic intermediates. Heme and glucose will downregulate ALA synthase (by inhibiting PPAR-gamma, which induces synthesis of ALA synthase), hence the efficacy of dextrose for tx.
How can non-selective B blockers contribute to hyperkalemia?
By blocking the B2 mediated K+ uptake by cells.
What kind of drug is indapamide?
A thiazide diuretic
What is bicalutamide and what can it be used for?
It is a testosterone receptor antagonist and can be used in the tx of prostate cancer.
What prevents the descending colon from undergoing ischemia when the IMA is obstructed during procedures like abdominal aortic aneurysm?
Anastamoses from the SMA (thru the marginal artery)
What does the appearance of vacuoles and phospholipid containing amorphous densities in mitochondria signify?
Irreversible cell damage.
What are the clinical manifestations of neonatal abstinence syndrome (withdrawal from opiates)?
irritability, hypertonia, jittery movements, seizures (rarely), diarrhea, vomiting, feeding intolerance, sweating, sneezing and pupillary dilation.
What makes up the anti-phagocytic capsule of B. anthracis?
Repeats of D-glutamate
What is meant by the term, “peritichous flagella?” Give an example of an organism that demonstrates this.
Means flagella uniformly across the entire surface of the bacterial cell. Proteus mirabilis is an example.
What is the most important prognostic factor for likelihood of melanoma to metastasize?
Vertical growth and thus its depth of invasion (called Breslow depth).
Multinucleated giant melanocytes are characteristic of what?
Lentigo maligna
Golden cytoplasmic granules in macrophages that turn blue w/ Prussian-blue staining are characteristic of what?
hemosiderin laden macrophages aka HF cells.
What enzyme does 5-FU inhibit
Thymidylate synthase
What is N5-formyl-tetrahydrofolate?
Leucovorin aka folinic acid
Dermatomyositis can occur as a paraneoplastic syndrome as part of an underlying malignancy. Which ones are most common?
Ovarian, lung, colorectal cancers and non-hodgkin lymphoma.
What is alirocumab?
It is a monoclonal antibody against PCSK9 - blocks the normal effect resulting in increased levels of LDL receptors on hepatocyte membranes.
What is the management of pyruvate dehydrogenase deficiency?
ketogenic diet. This means less pyruvate will be produced and so you won’t get the life-threatening lactic acidosis
What are the exclusively ketogenic amino acids?
Leucine and lysine
What is an abortive viral infection?
Where the virus enters the cell but does not successfully produce new viral particles. Therefore, it does NOT cause disease.
In terms of pharmacology, what is meant by the term “efficacy”?
Efficacy refers to the maximal ceiling of a drug with respect to a specific pharmacodynamic end point (i.e. how much it can dilate a blood vessel).
Name 2 vitamins that enteric bacteria are known for producing?
Vitamin K and folate
What enzymatic system can be involved in converting pro-carcinogens into carcinogens?
Cytochrome P450 monooxygenase
What is the difference btwn suppression and repression in terms of defense mechanisms?
In suppression the person is aware of the unpleasant feeling and consciously chooses to put the feelings aside to better focus on reality. Conversely, in repression the unpleasant feelings are not allowed to enter conscious awareness.
How can you distinguish btwn pituitary adenoma and ectopic ACTH secretion (i.e. paraneoplastic syndrome) for Cushing syndrome?
High dose dexamethasone suppression test. For pituitary adenoma this challenge will decrease the ACTH and cortisol levels whereas for the ectopic secretion the levels will remain unchanged.
When are cortisol levels highest in normal individuals?
In the morning
What is the translocation for BCR-ABL in CML? Also, what does this produce?
9;22, leading to a constitutively active tyrosine kinase
What is the difference btwn flutamide and finasteride?
Flutamide is an androgen receptor antagonist whereas finasteride is a 5a reductase inhibitor.
What sort of proteins do RAS genes code for? As such, when are they active?
RAS genes code for G proteins that are active when bound to GTP and inactive when bound to GDP
What is the mechanism of constitutively activating RAS mutations?
Mutations that decrease the instrinsic GTPase activity of RAS such that it is constantly in the GTP bound/on form.
Anterior compartment syndrome in the lower leg would impair what nerve? How about posterior compartment?
Anterior –> deep peroneal nerve
Posterior –> tibial nerve (maybe one other one too, not sure)
How does an MLF lesion present?
Internuclear ophthalmoplegia where there is weak adduction of the eye on the ipsilateral side and abduction nystagmus of the contralateral eye.
See p. 490 of First Aid for good diagram
What is a paraganglioma?
A tumor of chromaffin cells (like a pheochromocytoma) that arises outside of the adrenal medulla.
What is the histological appearance of medullary thyroid cancer?
Nests or sheets of polygonal or spindle-shaped cells w/ extracellular amyloid deposits.
Which thyroid cancer is known for having psammoma bodies?
Papillary thyroid cancer
What is the most common benign liver tumor?
Cavernous hemangioma
Which liver tumor can regress when oral contraceptives are stopped?
Hepatic adenoma
Chronic rhinosinusitis, asthma and peripheral eosinophikia are characteristic of what?
Churg-Strauss syndrome (aka eosinophilic granulomatosis w/ polyangiits).
What skin effect can be seen from constant application of topical corticosteroids? Why?
Dermal atrophy w/ loss of dermal collagen, drying, cracking and or tightening of the skin. This occurs b/c the steroids decrease production of ECM collagen and glycosaminoglycans.
What characterized dermatitis herpetiformis histologically?
Microabscesses containing fibrin and neutrophils in the dermal papillae tips
What skin condition is lamotrigine use associated w/?
Steven Johnson Syndrome
What is the path of CSF flow? Include ventricles and foramina
Lateral ventricles –> interventricular foramen of Monro –> third ventricle –> cerebral aqueduct –> fourth ventricle –> foramina of Luschka and Magendie –> subarachnoid space
What is a common sequelae of subarachnoid hemorrhage and how does it present?
Secondary vasospasm of the arteries surrounding the ruptured aneurysm. This usually occurs 4-12 days after and can cause ischemia presenting w/ focal neuro deficits and/or new onset confusion.
I think this is the most common sequelae as more than half the pts can get it.
What are the uterine arteries a branch of?
The internal iliac arteries
What lab value is elevated in suppurative parotitis?
amylase
What are RF for suppurative parotitis?
Dehydration, intubation, meds that decrease salivary flow, salivary flow obstruction, and recent intense teeth cleaning
What does gamma-glutamyl transpeptidase elevation suggest?
That alk phos elevation is due to liver and NOT bone pathology.
What is cinacalcet and when is it normally used?
It allosterically activates the Ca sensor in the parathyroid gland to suppress Ca++ secretion and is normally used in dialysis pts w/ secondary hyperparathyroidism.
What is sevelamer and when is it used?
It is a non-absorbable phosphate binding polymer that decreases P absorption and is used in dialysis pts w/ hyperphosphatemia
True or false, aspergillomas are asymptomatic?
False! They can be asymptomatic but can also present w/ cough and hemoptysis.
What are some extra-dermatological potential manifestations of psoriasis?
psoriatic arthritis, nail changes (yellow-brown discoloration, pitting, thickening or crumbling), conjunctivitis or uveitis
Which variant of thyroid cancer is known for having RAS mutations?
Follicular thyroid cancer
Inactivating p53 mutations are most commonly seen in which variant of thyroid cancer?
Anaplastic thyroid cancer
Of gastric and duodenal ulcers, which one is more likely to be malignant?
Gastric ulcers. Duodenal ones are rarely malignant and don’t need to be biopsied.
What is the pathophysiology of biliary atresia and how do pts present?
Pathophysiology: normal biliary tree at birth but then it subsequently undergoes destruction (they think due to viral or antibody mediated mechanism).
Pts present w/ jaundice w/in the first two months of life, dark urine (more bili in urine), acholic aka pale stools (minimal bili in stool), and w/ hepatomegaly and an elevated direct bili.
What fungal infection are central vascular catheters and total parenteral nutrition RF for?
Candidemia
How does theophyline toxicity present? Note that this drug has a narrow therapeutic index and is metabolized by the hepatic cytochrome oxidase system
Excess CNS stim (tremor, insomnia, seizures), GI disturbances, cardiac abnormalities (hypotension, tachycardia, arrhythmia).
What part of the body is injured in Osgood-Schlatter disease?
The secondary ossification center of the tibial tubercle.
What characterizes GBM histologically?
pseudopalisading necrosis and new vessel formation
Which brain tumor has a whorled pattern of growth and often has psammoma bodies?
meningioma
Name 3 infiltrative diseases that can cause restrictive cardiomyopathy?
Amyloidosis, sarcoidosis, and hemochromatosis.
In what condition is there extracellular deposition of wild type transthyretin?
senile systemic amyloidosis
About half of pts w/ giant cell arteritis also have what?
polymyalgia rheumatica
Transmural inflammation of the vessel wall w/ fibrinoid necrosis is consistent with?
Polyarteritis nodosa
What would bx of calf muscle in Duchenne pt w/ pseudohypertrophy show later in the disease?
Replacement of muscle w/ fat and connective tissue.
What is the timeframe for when the following things present in alcohol withdrawal?
- Tremor/tremulousness, anxiety, insomnia, diaphoresis, GI upset and tremors?
- seizures?
- visual, auditory or tactile hallucinations?
- delerium tremens (confusion, agitation, fever, tachycardia, HTN, hallucinations)?
- Tremor/tremulousness, anxiety, insomnia, diaphoresis, GI upset and tremors –> 6-24 hours
- seizures –> 12-48 hours
- visual, auditory or tactile hallucinations –> 12-48 hours
- DTs –> 48-96 hours
What gives the elastic character to elastin?
Tropoelastin interacts w/ fibrillin (a scaffold) and lysyl oxidase forms desmosine cross-links btwn neighboring polypeptides. Said cross links are what account for its elastic properties.
What do E6 and E7 viral proteins in oncogenic HPV interact w/?
E6 –> p53
E7 –> Rb
*Together these interactions inhibit cell cycle regulation and lead to cell proliferation.
What does topoisomerase I do and what drug(s) inhibit it?
Induces single strand breaks in DNA to prevent negative supercoiling. Irinotecan and topotecan inhibit it.
What does topoisomerase II do and what drug(s) inhibit it?
Induces transient double strand breaks in DNA to reduce both positive and negative supercoiling. Etoposide inhibits it
What does the presence of odynophagia usually indicate in the setting of GERD?
That it has progressed to erosive esophagitis and that there is an ulcer now.
Describe the phenomenon of aldosterone escape
It is the physiology that explains why people w/ hyperaldo don’t develop frank volume overload (or at least rarely do). What happens is the increased Na reabsorption stimulates increased renal blood flow (w/ resulting pressure natriuresis) and increased ANP that also prevents volume overload from occurring –> this is why pts w/ Conn syndrome have a normal serum Na.
In the Rhinne test, if bone conduction is greater than air conduction, what does that signify?
Conductive hearing loss for that ear
Where does hearing localize to in the Weber test for conductive and sensorineural hearing loss?
Conductive –> goes to affected ear
Sensorineural –> goes to opposite ear
What does GAS’s M protein do?
It is antiphagocytic and inhibits the activation of complement
Which nephritic/nephrotic syndrome is associated w/ anti-phospholipase A2 receptor antibodies?
Idiopathic membranous nephropathy