Missed Questions Retake Flashcards Preview

UWORLD STEP 1 > Missed Questions Retake > Flashcards

Flashcards in Missed Questions Retake Deck (91):
1

Adolescent with neuropathic pain (burning sensations) and hypohidrosis (decreased sweating) exacerbated by stress, exercise, and fatigue. Later he develops angiokeratomas (dark red, non-blanching macules and papules in clusters over the butt, groin, and umbilicus) and telangiectasias.

What is the diagnosis?

Fabry Disease

X-linked recessive

alpha-galactosidase A deficiency

Buildup of globotriaosylceramide

Leads to: cerebrovascular and cardiac issues, renal failure due to Gb3 buildup

2

How does sepsis cause ARDS?

As cytokines circulate in response to the infection, they activate the pulmonary epithelium and provoke an inflammatory response mediated by neutrophils. This leads to capillary damage and the leakage of protein and fluid into the alveolar space.

3

Newborn girl with normal internal genitalia but ambiguous or male-type external genitalia (clitoromegaly). Baby caused mother to be virilized (hirsutism, deep voice). What is deficient in the baby?

Aromatase Deficiency

AR

High androgen and low estrogen in a female fetus.

4

What enzyme functions exclusively in the nucleolus?

RNA Polymerase 1

Transcribes 45S pre-rRNA into a template that is processed into mature 18S, 5.8S, and 28S rRNAs.

FORMATION OF RIBOSOMES

5

Functions of IL-2

1. Proliferation and differentiation of Helper T cells

2. Monocyte activation

3. NK Cell activation

4. Growth of T cells and INF gamma secretion

5. Stimulation of division of B cells

*Anti-cancer effect on metastatic melanoma and renal cell carcinoma*

6

First line treatment for Narcolepsy (daytime) for stimulation

Modafinil

Non-amphetamine stimulant

Well-tolerated

Rarely causes drug abuse

7

What is a developmental field defect?

Multiple malformations that occur secondary to an embryonic disturbance in an adjoining group of cells.

Ex = holoprosencephaly

8

Penicillins, cephalosporins, and vancomycin target what part of an organism?

Peptidoglycan cell wall 

9

Most common pathogens causing nosocomial bloodstream infections

Coag neg staph

Staph aureus

Enterococci

Candida

10

An IL-1 or TNF-alpha inducible enzyme that is highly expressed by inflammatory cells and undetectable in surrounding normal tissue....

COX-2

Target it specifically with Celecoxib

 

11

An increased total RBC mass in the presence of an increased hematocrit level

Absolute Erythrocytosis

12

Increased hematocrit with normal RBC mass

Relative Polycythemia

Likely due to dehydration or excessive diuresis

13

Absolute polycythemia with decreased Erythropoietin levels

Primary erythrocytosis

Caused by a myeloproliferative disorder like PV

14

Absolute polycythemia with increased erythropoietin levels

Secondary erythrocytosis

Chronic hypoxia from high altitudes, smoking, COPD OR abnormal secretion by neoplastic or otherwise diseased tissues

15

Pt. with hemolytic anemia, hypercoagulability (hepatic vein thrombosis), pancytopenia

Paroxysmal nocturnal hemoglobinuria (PNH)

Absence of GPI anchor and CD55 and CD59 deficiency leads to complement-mediated hemolysis (more often at night due to lower blood pH)

16

What is the only prokaryotic polymerase with 5'-3' exonuclease activity?

DNA Polymerase 1

Removes the RNA primer created by RNA primase and repairs damaged DNA sequences.

17

In a patient with acute mesenteric ischemia, what causes the resulting acid-base disorder?

Inadequate delivery of oxygen to intestinal tissues --> hypoxic conditions --> intracellular accumulation of NADH --> inhibition of pyruvate dehydrogenase --> pyruvate is converted to lactate --> lactic acidosis

18

This type of cell found on a pap smear... sign of what?

Koilocyte

HPV infection - double stranded, non-enveloped DNA virus with a predilection for squamous epithelium of skin/vagina/cervix

19

Leuprolide has what initial effect on hormones?

GnRH agonist that causes a transient increase in pituitary LH secretion, which leads to a rise in testosterone levels. If used continuously, it will suppress LH release and lead to a decrease in testosterone production.

20

Kyphoscoliosis

High arches (pes cavus)

Hypertrophic cardiomyopathy and CHF

Gait ataxia

Spastic muscle weakness

Loss of position and vibration sensation

Diabetes mellitus

Friedreich ataxia

AR

Mutated frataxin gene --> GAA repeats

Decreased mitochondrial energy production and increased oxidant stress -->

1. Spinocerebellar and Lateral corticospinal tract degeneration

2. Dorsal column and DRG degeneration

21

Enteropeptidase is responsible for activation of what? Where is it located?

Trypsin

Jejunal brush border enzyme

Deficiency = protein and fat malabsorption --> diarrhea, failure to thrive, edema

22

Lesion of the lateral optic chiasm can cause ipsilateral nasal hemianopia. An issue with what artery can cause this issue?

Aneurysm of the internal carotid (cavernous or opthalmic segments)

 

*uncrossed optic nerve fibers from the temporal portion of the retina*

23

Spontaneous deep intracerebral hemorrhage 

Hypertensive vasculopathy from penetrating branches of major cerebral arteries.

Basal ganglia (putamen), cerebellar nuclei, thalamus, pons

Lenticulostriate arteries off MCA --> basal ganglia

24

Postpartum hemorrhage is usually due to what artery?

Internal iliac --> uterine arteries

25

Clue cells

Epithelial cells covered with gram-variable rods

Gardnerella vaginalis (bacterial vaginosis)

Off-white discharge

Fishy odor

Metronidazole or Clindamycin

26

Thick cottage cheese discharge from cervix

Normal pH

Candida vaginitis

Pseudohyphae

Give Fluconazole

27

Most characteristic skeletal abnormality of Primary Hyperparathyroidism

Osteitis Fibrosa Cystica:

Cortical (compact) bone: pelvic girdle, pectoral girdle, limbs)

Bone pain

Subperiosteal erosions affecting fingers

Salt-and-pepper skull

Brown tumor bone cysts in long bones

28

Pt presents with constipation, new-onset 2nd degree AV block, and syncope in the setting of a new medication for atrial fibrillation

Calcium channel block

Diltiazem, Verapamil

29

Kid with poor exercise tolerance, muscle cramps, and rhabdomyolysis

McArdle disease

Deficient myophosphorylase

30

Major virulence factor for Strep Pyogenes that inhibits phagocytosis and the activation of complement

Protein M

31

Functions of Insulin

Increases peripheral glucose uptake

Inhibits lipolysis

Inhibits ketoacid formation

Decreases glucagon release

32

What class of antiarrythmetics prolongs QRS duration without affecting the QT interval?

Class 1C

Flecainide

Propafenone

*only affect fast sodium channels*

33

Direct thrombin inhibitors are the DOC for treating what? Why?

Heparin-induced thrombocytopenia (HIT)

They do not require antithrombin-3 for their action because they bind directly to the thrombin active site.

Argatroban, Hirudin, Lepirudin

34

Which TB drug causes optic neuropathy?

Ethambutol

35

Ascertaining a patient's volume status and checking urine chloride are important steps in working up what?

Metabolic Alkalosis

36

Crescent formation in RPGN is caused by the deposition of what?

Deposition of fibrin within Bowman's space + proliferatied glomerular parietal cells, monocytes, macrophages that have migrated into Bowman's space

37

What lab value should be checked before initiation of metformin?

Serum creatinine

Metformin inhibits hepatic gluconeogenesis and increases peripheral glucose utilization. Lactic acidosis is a rare complication of metformin therapy, but it's risk is increased in pts with underlying renal insufficiency.

38

Host cell is coinfected with 2 viral strains and progeny virions contain unchanged parental genome from 1 strain and nucleocapsid (or envelope) proteins from the other strain.

Phenotypic Mixing

Due to the lack of change in the underlying genome, subsequent progeny will revert to having only one viras type surface protein again.

39

Autopsy findings of endocardial thickening and fibrosis of tricuspid and pulmonary valves are characteristic of what?

Carcinoid heart disease

40

Pathogenesis of carcinoid heart disease

Excessive secretion of serotonin, which stimulates fibroblast growth and fibrogenesis.

Plaque like deposits of fibrous tissue usually in endocardium, lead to tricuspid regurgitation, pulmonic valve issues, and right  sided heart failure (ascites, peripheral edema)

41

Why is carcinoid heart disease limited to the right side of the heart?

Vasoactive products are inactivated distally by pulmonary vascular endothelial MAO

42

27 y/o with recurrent episodes of muscle weakness (hypokalemia), high BP, very low plasma renin

Primary Hyperaldosteronism

Bilateral nodular hyperplasia

Hyperfunctioning adrenal glomerulosa (mineralocorticoids) or an aldosterone-producing adrenal adenoma (Conn syndrome)

43

Proto-oncogenes stimulate cell proliferation, and their overexpression/amplification (activating mutation) leads to increased cellular proliferation and neoplastic growth. What are they?

ABL

BRAF

HER1/2

MYC

RAS (KRAS, HRAS)

SIS

TGFA

44

What are the tumor suppressor genes? Their inactivation contributes to tumor development.

APC

BRCA

DCC

NF1

RB

TP53

VHL

WT1

45

Infection with systemic symptoms (fever, wt. loss), painful oral ulcers, lymphadenopathy, and hepatosplenomegaly. 

Histoplasma

Causes disseminated mycosis in immunocompromised pts.

Can survive intracellularly within macrophages.

46

What bug is + for PYR (pyrrolidonyl arylamidase)?

Strep Pyogenes

PYR is more specific than bacitracin.

47

8 year old with vomiting and lethargy after a period of fasting. Low glucose, SUPER high AST and ALT. Begins seizing. What is deficient?

He has hypoketotic hypoglycemia

Defect in fatty acid beta oxidation in the mitochondria. 

Most common enzymatic defect leading to this is acyl-coA dehydrogenase. 

This kid cannot oxidize fatty acids for energy or produce ketone bodies when fasting.

48

What would you treat MRSA with if a pt. is allergic to vancomycin?

Daptomycin

Depolarizes cellular membrane by creating transmembrane channels.

It is inactivated by surfactant so it is not useful for pneumonia.

AE = Increased CPK, myopathy

49

Treatment of urea cycle disorders consists of what?

Balancing dietary protein intake and output, so the body receives the essential amino acids needed for growth and development but not in excess such that excessive ammonia is formed.

50

Pathogenesis of acute decompensated heart failure

Compensatory neurohumoral stimulation: increased sympathetic --> RAAS activation --> release of ADH

This improves CO by increasing cardiac chronotropy and iontropy, expanding the extracellular fluid compartment, and causing arterial and venous vasoconstriction.

BUT it also leads to increased afterload, excess fluid retention, and deleterious cardiac remodeling.

51

A parent's authority to make medical decisions for their children can be challenged in cases in which a child is at significant risk for harm. What should a Dr. do?

Obtain a court injunction to proceed with life-saving medical treatment of the child

52

A pt. with DiGeorge syndrome will cause what change in a lymph node?

Poor development of the LN paracortex due to an extreme deficiency in the number of mature T lymphocytes

53

Septic shock results from release of endotoxins. What is the source of endotoxin in Gram - bacteria?

Lipid A from LPS

It activates macrophages and granulocytes leading to the synthesis of endogenous pyrogens (IL-1, prostaglandins, TNF alpha, interferon)

54

The posterior part of the external auditory canal is inervated by what nerve?

Vagus (auricular branch)

Stimulation with an otoscope can cause vasovagal syncope --> parasympathetic outflow via the vagus nerve leads to decreased HR and BP

55

The majority of the posterior surface of the heart is what?

LA

56

What lies posterior to the esophagus and can be seen with transesophageal echocardiography?

Descending thoracic aorta

57

Gastric varices found in the FUNDUS of the stomach are due to an issue with what vein?

Short gastric veins --> splenic vein

58

Most inhaled particles that lodge in the bronchial tree are removed how?

Via proximal transport of mucus by ciliated epithelial cells (mucociliary clearance)

59

Macrophages are used to clear particles inhaled if in what part of the lung?

Distal to the terminal bronchioles

60

What drugs can be used to assist in prevention of cerebral vascular spasm after a subarachnoid hemorrhage?

Calcium channel blockers (specifically Nimodipine)

61

IgA protease produced by Neisseria species, strep pneumo, and h. flu has what purpose?

It cleaves secretory IgA at it's hinge region, rendering it ineffective.

This allows bacteria to adhere to mucosa

Secretory IgA normally acts to bind and inhibit the action of pili as well as other cell surface antigens that normally mediate mucosal adherence and subsequent penetration.

62

Child with Lower-extremity claudication (cramping with exercise), blood pressure discrepancy between the upper and lower extremities, and delayed or dimished femoral pulses

Aortic Coarctation

Associated with Turner Syndrome (45, XO)

63

Myxomatous changes with pooling of proteoglycans in the media layer of large arteries are found in cystic medial degeneration, which predisposes to the development of what?

Aortic Dissections

Aortic Aneurysms

*frequently seen with Marfan Syndrome*

64

Concurrent use of a statin with what drugs is associated with increased incidence of statin-induced myopathy and rhabdomyolysis (and therefore acute renal failure)?

CYP 450 Inhibitors:

CRACK AMIGOS

 

65

Maple Syrup Urine Disease

AR

Defective breakdown of branched chain amino acids (leucine, isoleucine, and valine)

Branched-chain alpha ketoacid dehydrogenase requires 5 cofactors:

Thiamine

Lipoate

Coenzyme A

FAD

NAD

66

Branched chain alpha ketoacid dehydrogenase

Pyruvate dehydrogenase

Alpha-ketoglutarate dehydrogenase

All of these require what?

Thiamine

Lipoate

Coenzyme A

FAD

NAD

67

Progressively weakening diaphragmatic contractions during maximal voluntary ventilation with intact phrenic nerve stimulation indicates what?

Neuromuscular junction pathology (MG)

OR abnormally rapid diaphragmatic muscle fatigue (Restrictive lung disease or chest wall disease)

68

The adrenal medulla is sharply demarcated from the cortex and is composed of chromaffin cells with deeply basophilic cytoplasm. What activates the cells?

ACh

69

Down syndrome predisposes to what cancer?

ALL

70

A physiologic increase in maternal insulin resistance occurs during the 2nd and 3rd trimester due to the action of what?

Human Placental Lactogen (hPL)

Secreted by the syncytiotrophoblast

71

A pt. from Guatemala with no underlying immunocompromising conditions has a seizure and is found to have a cystic lesion in his brain.

Neurocysticercosis

Taenia Solium (pork tapeworm)

Ingestion of eggs excreted in feces of human carriers

Eosinophilia

72

Effects of Nitroprusside

Decreases LV preload and afterload

No change in stroke volume

73

Acute angle closure glaucoma treatment preference works how?

Acetazolamide

Inhibits carbonic anhydrase

Affects the PCT

74

Child with hepatosplenomegaly, neurologic regression, hypotonia, and a cherry-red macular spot in infancy

Neimann-Pick disease

AR

Ashkenazi Jews

Sphingomyelinase deficiency

Accumulation of sphingomyelin

75

Ehler's Danlos syndrome pathogenesis

Defective collagen synthesis

Deficiency of procollagen peptidase, the enzyme that cleaves terminal propeptides from procollagen in the extracellular space.

Joint laxity, hyperextensible skin, fragilt tissues with easy bruising, poor wound healing

76

The anterior compartment of the leg contains what?

Deep peroneal nerve

Anterior tibial artery and veins

77

Empty can test is testing what muscle of the rotator cuff?

Supraspinatus

Most commonly affected muscle due to chronic repeated trauma from impingement between the head of the humerus and the acromion during abduction.

78

Pts. with Chronic Granulomatous Disease develop recurrent bacterial and fungal infections that are caused by what?

5 catalase-positive organisms:

Staph aureus

Burkholderia cepacia

Serratia

Nocardia

Aspergillus

79

Complication that happens within 5-14 days of a large anterior transmural MI

Free wall rupture --> hemopericardium and tamponade --> profound hypotension and shock

During this timeframe, the infarcted myocardium is substantially weakened by coagulative necrosis, neutrophilic and macrophage infiltration, and enzymatic lysis of myocardial connective tissue.

80

A 1 month old male with persistent jaundice, muscle rigidity, lethargy, and seizures. What is the most likely cause of his hyperbilirubinemia?

Absent UGT (liver conjugation enzyme) needed to catalyze bile glucuronidation.

Crigler-Najjar Type 1 (AR)

81

Exaggerated drop in systolic BP during inspiration

Pulsus Paradoxus

Impaired expansion into pericardial space

82

Most frequent causes of pulsus paradoxus in the absence of significant pericardial disease?

Astham

COPD

83

Drugs used for acute asthma and COPD exacerbations

Beta-adrenergic agonists --> cause bronchial smooth muscle relaxation via increased intracellular cAMP

84

Best treatment for generalized epilepsy

Broad-spectrum anticonvulsants:

Valproic acid

Lamotrigine

Topiramate

85

Hexagonal shaped urinary crystals

Cystinuria

(Aminoaciduria)

Sodium cyanide-nitroprusside test 

Treat = increased hydration and urinary alkalinization (acetazolamide)

86

Spina bifida has what mode of inheritance?

Multifactorial

87

Cholesterol Gallstones

MC type

Due to decreased amounts of bile aids and phospholipids cause the bile to become supersaturated with cholesterol.

Treat = hydrophilic bild acids will promote gallstone dissolution

88

Human tumor cells can resist chemotherapy via the human multidrug resistance (MDR1) gene. This makes what?

P-glycoprotein, a transmembrane protein that functions as an ATP-dependent efflux pump. This can actively remove chemo agents, particularly hydrophobic agents like the anthracyclines.

89

At low doses, Atenolol is selective for what?

Selective B1 adrenergic antagonist

Only works on cardiac and renal juxtaglomerular cells

NOT vascular smooth muscle

90

Pt. with HIV with HA, seizures, and multiple ring enhancing CNS lesions on MRI

Toxoplasmic Encephalitis

91

Pigment gall stones

Calcium salts of unconjugated bilirubin

Soft, dark brown to black 

Usually arise secondary to bacterial or helminthic infection of the biliary tract resulting in the release of beta-glucuronidase by injured hepatocytes and bacteria.

Beta-glucuronidase hydrolyzes bilirubin glucuronides and increases the amound of unconjugated bilirubin.