Uworld: 6-1

Front 1

23 year-old female
Malar rash, proteinuria, joint pain
LAD
Lymphocytes show functionally defective FAS gene product

Effect of this mutation

Back 1

Impairs efficacy of CTLs in deleting clones of autoreactive T lymphocytes

AS a result, those self-recognizing T lymphocytes go on to cause considerable damage

Front 2

Ligaments preventing anterior/posterior displacement.

Back 2

Anterior = ACL
Posterior = PCL

Front 3

64 year-old male
Difficulty walking
Reports muscle cramps after walking on level ground
Cramps subside with rest
Decreased sexual performance
h/o MI and carotid endarterectomy

Diagnosis
Pathophys

Back 3

Intermittent claudication (muscle pain w/exercise that remits with rest) is almost ALWAYS result of ATHEROSCLEROSIS of larger named arteries.

Obstruciotn of blood flow in arteries results from fixed stenotic atheromatous lesions.

Note that atheromas are lipid-filled intimal plaques that bulge into arterial lumen.

These stenoses prevent sufficient increase in blood flow to muscles during exercise, resulting in ischemic muscle pain.

Front 4

ADH receptors:
Effects of stimulating each

Back 4

V1: Vasoconstriction and inc'd PG release

V2: Located in MEDULLARY portion of CD, allows for enhanced water permeability of principal cells

Front 5

How does the cortical segment of the CD differ from the medullary segment (functionally)?

Back 5

Cortical segment promotes sodium reabsorption via ALDOSTERONE

Medullary segment has V2 receptors and allows reuptake of water

Front 6

22 year-old female
Acute onset abdominal pain, nausea, confusion
Several episodes of abdominal pain correlating with alcohol use
Urine turns dark upon standing
IV dextrose immediately improves symptoms

Diagnosis
Pathophys
Pathophys of treatment

Back 6

Patient suffers from acute intermittent porphyria

ALA synthase is rate limiting step of heme production; it is INDUCED by EtOH, barbiturates, hypoxia, griseofulvin (anything inducing P450)

A deficiency of HMB synthase (Porphobilinogen-->Uroporphyrinogen) will result in an accumulation of ALA and Porphobilinogen (formed by ALA dehydratase), which are toxic to human tissues.

Remember that deficiencies of early steps of heme synthesis cause neuro syx w/o photosensitivity, while derangements in latter steps cause photosensititivy.

Exposure of urine to light in pts excreting large amounts of porphyrinogen results in light induced formation of porphyrins and darkening of color of urine.

Treatment with high dose glucose will INHIBIT ALA synthase and decrease the amount of ALA and Porphobilinogen made.

Front 7

When are Psammoma bodies seen?

Back 7

Papillary Thyroid Cancer
Serous Ovarian Adenocarcinoma
Meningiomas
MESOthelioma

Front 8

Back 8

Oligodendroglioma

Front 9

Back 9

Psammoma bodies-->meningioma

Front 10

54 year-old man
Administered unknown drug
Develops flushing, diaphoresis, nausea
BP 100/70, pulse 55/min
Pupils constricted but reactive to light

ID Drug Given
Under what circumstances would you give this drug?

Back 10

Patient received a cholinergic agonist; these drugs increase GI smooth muscle tone to produce nausea, vomiting, abdominal cramps, diarrhea; also decrease heart rate, cardiac conduction and contractility, and may result in bradycardia, hypotension

Bethanechol used to stimulate peristalsis in POSTOPERATIVE ILEUS

Also used to treat non-obstructive urinary retention (ATONIC BLADDER)

Carbachol and pilocarpine used to lower intraocular pressure in GLAUCOMA

Front 11

Describe the steps ingested cholesterol takes to becoming bile salts.

When do gallstones occur?

Back 11

Free cholesterol-->cholic and chenodeoxycholic acids (Bile acids)
Bile acids conjugated to either glycine or taurine-->bile salts
-->Secreted into bile canaliculi
Phosphotidylcholine helps cholesterol become more soluble as well

Circumstances for developing gallstones:
-High cholesterol
-Low bile acids
-High phosphatidylcholine

Front 12

Key laboratory findings of DKA (relevant to pH).

Back 12

DKA is assocd w/high anion gap metabolic acidosis accompanied by a compensatory RESPIRATORY alkalosis (will blow off CO2-)

pH = acidic
Serum bicarb = LOW
PaCO2 = low

Front 13

What is the most common pituitary adenoma?

Back 13

Prolactinoma

Front 14

Why do patients with CREST syndrome develop esophageal dysphagia?

What will be seen on barium esophagram?

Back 14

Systemic sclerosis results in excessive tissue fibrosis (hallmark of systemic sclerosis)

Esophageal dysmotility is result of atrophy and fibrous replacement of esophageal muscles.

Esophageal body and LES become ATONIC and DILATED, resulting in severe reflux.

Barium esophagrum will display dilated esophagus and absent peristalsis.

Front 15

Which viruses comprise the picornaviridae family?
Which are acid labile?
Acid stable?

Back 15

Enteroviruses:
-Coxsackie A
-Echovirus
-Poliovirus
-Hepatitis A virus

All of the above are acid STABLE, because they are ingested and need to survive the acidic environment of the stomach.

The only acid-labile of the group is RHINOVIRUS, which is inactivated by stomach acid.

Front 16

What drug must be given in combination with cisplatin?

Why?

Back 16

Cisplatin formes ROS that can cause severe nephrotoxicity.

Need to give AMIFOSTINE--a thiol-based cytoprotective free-radical scavenger used to decrease nephrotoxicity assocd w/platinum-containing agens.

Front 17

Green vs Rust-Colored Sputum:
Causes

Back 17

Green = myeloperoxidase (granules of neutrophils) in bacterial infections

Rust = blood; due to hemolysis in alveolar infection (extravasation of blood)

Front 18

Toxic Shock Syndrome:
Pathophys

Back 18

Staph aureus produces TSST-1 which acts as superantigen

ACtivates large number of helper T cells which release IL-2, and macs which release IL-1 and TNF

These interleukins cause capillary leakage, circulatory collapse, hypotn, shock, fever, skin findings, and multiorgan failure

Front 19

List the 4 MAOIs.

Which is selective?

Back 19

Phenelzine
Tranylcypromine
Isocarboxazid
Selegiline (selective MAO-B inhibitor)

Front 20

75 year-old male
Calcification of aortic valve

Cause of calcification?

Back 20

Calcification is a hallmark of cell injury and death, it occurs in ALL necrotic tissues, including fat necrosis.

Damaged cardiac valves and atheromatous plaques are calcified bc of cell death.

Front 21

43 year-old female
Presents with reduced energy, fatigue, hypocrhomic microcytic anemia
Treated with iron supplementation
Several weeks later, peripheral smear demonstrates enlarged RBCs that appear blue on Wright-Giemsa stain

Why?

Back 21

Inc'd BM erythropoiesis results in accelerated release of immature RBCs (reticulocytes) into bloodstream.

Reticulocytes contain BLUISH cytoplasm and reticular precipitates of residual RIBOSOMAL RNA which stain blue on Wright-Giemsa stain.

Front 22

Where do H. pylori colonize?
Effects?
Site of ulceration?

Back 22

H. pylori live in the mucus layer overlying the epithelium of gastric antrum and fundus

Use mucus and urease to protect themselves from stomach acid.

H. pylori associated gastritis leads to a decrease in number of SMS-producing antral cells.

SMS normally inhibits gastrin release; high gastrin levels cause inc'd local release of histamine, which stimulates gastric parietal cells to secrete inc'd levels of acid.

Low pH gastric fluid enters duodenum and if not neutralized causes duodenal ulceration.

Front 23

Most chemical carcinogens enter the body in an inactive state (pro-carcinogens), how do they become activated?

Name the specific enzyme.

Back 23

Microsomal monooxygenase--the enzyme otherwise known as cytochrome p450.

Front 24

Increased WBC
Peripheral smear shows immature cells (bands, metamyelocytes, myelocytes)
Very few blasts
Leukocyte alkaline phosphatase is low

Diagnosis

Back 24

CML

Front 25

Increased white blood cell count
Peripheral smear shows many immature cells (bands, metamyelocytes)
Very few blasts
Leukocyte alkaline phosphatase is elevated

Back 25

Leukemoid reaction--over-exuberant WBC response resulting from bacterial infeciton, malignancy

Neutrophil alkaline phosphatase levels will be normal OR elevated

Front 26

Increased white blood cell count
Mostly myeloblasts (>20%)

Back 26

AML

Front 27

Increased white blood cell count
Mostly mature lymphoid cells
Normal myeloid cell count

Back 27

CLL

Front 28

t(9;22)

Back 28

CML--Philadelphia Chromosome

Front 29

63 year-old man
New-onset dyspnea, wheezing
Facial flushing, diarrhea
CT scan shows mass lesions in right live lobe and appendix

Diagnosis
Treatment

Back 29

Patient has carcinoid syndrome (production of 5HT)

Treat with octreotide to inhibit secretion of many hormones

Front 30

What is the effect of hyperventilation on cerebral blood flow?

Back 30

Decreases cerebral blood flow due to lower CO2

Front 31

Which bugs are catalase positive and pose a threat to patients with CGD?

Back 31

Remember: pts with CGD have deficient NADPH and have very little H2O2 to work with.

Bugs are:
Staph aureus (duh)
Pseudomonas
Aspergillus
Nocardia
Serratia

Front 32

Protamine is the antidote for ______.

Back 32

Heparin

Front 33

Aminocaproic acid is the antidote for __________.

Back 33

Streptokinase
tPA

Front 34

12 year-old male
Ataxia
Episodic erythematous and pruritic skin lesions
Loose Stools
Loss of neutral aromatic amino acids in urine (tryptophan)

Diagnosis
Treatment

Back 34

Patient has Hartnup disease (mostly asyx) but results in tryptophan wasting

Tryptophan is needed to form NIACIN--patient is presenting with syx of niacin deficiency.

Give niacin!

Front 35

Non-amphetamine stimulant used in narcolepsy

Back 35

Modafinil

Front 36

Etanercept:
MOA
Use
Precautions

Back 36

Etanercept is a TNF-alpha inhibitor used to treat moderate to severe RA (esp when have failed MTX tx)

Can cause reactivation of Tb; need to have PPD before starting treatment.

Front 37

First-line treatment for high triglycerides.

Back 37

Fibrates

Front 38

Grows in bile AND 6.5% NaCl
VS
Grows in bile but NOT 6.5% NaCl:
Identify bug
Associated procedures

Back 38

Grows in bile and salty water: Enterococci, E. faecium (acquired after GU procedure)

Don't grow in salty water:
Strep bovis (colonic malignancy)

Front 39

Sensation between big toe and second toe.

Back 39

Deep peroneal

Front 40

Anti-fungals that:
Act on cell wall (glucans)
Act on cell membrane (2 MOAs)
Act on DNA/RNA synthesis

Back 40

Cell wall: Caspofungin; inhibit glucan synthesis

Cell membrane: Ampho B and Nystatin (both bind ergosterol); Azole (INHIBIT SYNTHESIS of ergosterol)

DNA and RNA synth: Flucytosine (pyrimidine)

Front 41

Exudate vs Transudate

Back 41

Exudate: extravasation of plasma water and plasma proteins (seen in inflammatory states)

Transudate: ultrafiltrate of plasma caused by hemodynamic changes

Front 42

Tb drug resulting in optic neuritis.

Back 42

Ethambutol

Front 43

Which thyroid cancer:
spindle-cells
elevated serum calcitonin

Back 43

Medullary

Front 44

Caucasian newborn
Develops abdominal distention
Begins vomiting bilious fluid soon after birth
Abdomen shows air fluid levels and dilatation of small bowel
Laparotomy reveals inspissated green fecal mass obstructing lumen of distal ileum

Diagnosis
What is patient likely to die of?

Back 44

Green mass suggests distal ileum has been obstructed by dehydrated meconium.

Cystic fibrosis is most common case of meconium ileus (leads to isotonic dehydration of lumen contents)

Patient likely to die of pneumonia.

Front 45

How does a strawberry hemangioma change over time?

Back 45

First increases in size and then regresses

Front 46

22 year-old female
Recurrent abdominal pain and anxiety
Symptoms improve following IV administration of heme preparation

What enzyme was inhibited?
What other substance inhibits this?

Back 46

ALA synthase!

It only makes sense that lots of heme inhibits heme synthesis!!!

Glucose does this too.

Front 47

44 year-old
HIV positive
Pains in arms, legs
Irregular, unequal pupils that respons to light, but do not constrict on accommodation
Positive Romberg
Deep tendon reflexes absent

Diagnosis
Type of organism (family)

Back 47

This is neurosyphilis, a spirochete

Areflexia and positive Romberg indicate tabes dorsalis (dorsal columns, dorsal roots)--loss os positional sense (hence cannot maintain balance with closed eyes, a positive Romberg)

INvolvement of dorsal sensory roots leads to loss of pain sensation and areflexia

Accommodating but non-reactive pupils are Argyll Robertson pupils

Front 48

Major causes of aortic stenosis.

Back 48

Calcification (bicuspid aortic valve)
Rheumatic heart disease

Front 49

Sputum culture grows budding yeast that forms germ tubes at 37ºC.

Organism?

Back 49

Candida albicans--a part of normal flora (not an abnormal finding)

Front 50

57 year-old female
Fever, chills, RUQ pain
Fluid-filled cavity in right lobe of liver

What is the likely organism and how did it get there?

Back 50

Likely staph aureus via hematogenous route (seeding from another site)

Front 51

What connection between cardiac chambers is considered a variant of normal in an adult patient?

Back 51

Patent foramen ovale--usually remains functionally closed, but any abnormality increasing RA pressure above LA pressure can produce R to L shunt.

Front 52

Prussian blue stain:
When does something turn blue?
What would this indicate if it's found in alveolar cells?

Back 52

Prussian blue stain detects intracellular iron. Iron will turn blue.

When there is increased intravascular pressures in pulmonary capillary bed, iron-containing proteins and erythrocytes are extravasated into alveoli, phag'd by macs, and converted to hemosiderin.

Finding macs with hemosiderin (iron) in the alveoli indicates chronic left-sided heart failure (build up of pressure for lungs).

Front 53

34 year-old male
Brother died of liver cirrhosis
Serum ferritin of 1800 µg/L

What does the ferritin tell you?
What is the mutation involved here?

Back 53

Ferritin = stored iron

Patient has hereditary hemochromatosis due to a mutation to the HFE gene (HLA-H).

This patient will have abnormally elevated intestinal absorption.

Front 54

IgG4 antibodies to phospholipase A receptor (PLA2R)--a transmembrane protein abundant on podocytes

Diagnosis

Back 54

Membranous nephropathy--HUGE PROTEIN LOSS

Front 55

73 year-old male
Epigastric pain that starts 30-40 minutes after meals
Doesn't respond to antacids
PMH significant for HTN, HLD, CABG
GI endoscopy normal

What's the cause?

Back 55

Generalized atherosclerosis

Involvement of intestinal arteries (bowels have diminished blood supply), pronounced after meals

Often caused by atherosclerotic narrowing of the celiac trunk, SMA, and IMA

Weight loss is COMMON (many pts avoid pain a/w eating)

Front 56

Babinski sign indicated damage to UMN/LMN.

Back 56

UMN

Front 57

How did this happen (basic cell processes)?

Back 57

This shows a cystic cavity surrounded by gliosis--macroscopic appearance of an OLD CEREBRAL INFARCT (LIQUEFACTIVE NECROSIS)

Release of lysosomal enzymes from ischemic neurons results in degradation of tissue in ischemic region.

Phagocytic cells migrate, remove necrotic tissue leaving a cavity, astrocytes proliferate around necrotic area with formation of a scar (Gliosis).

Complete digestion of necrotic tissue w/formation of a cavity = liquefactive necrosis.

Front 58

Scrotal vs Testicular Lymph Drainage

Provide alternative names

Back 58

Lymph from scrotum-->inguinal LNs

Lymph from testes-->para-aortic AKA RETROPERITONEAL nodes

Front 59

Lung is opacified
Trachea is deviated

What would cause deviation of the trachea and in which directions (relative to opaque lung)?

Back 59

Trachea deviates toward opacified lung in setting of volume loss (atelectasis)

Away from opacified lung in setting of large pleural effusion

Front 60

65 year-old smoker
CXR shows complete opacification of right lung
Tracheal deviation to right

Back 60

Because this pt is a smoker, he likely has a lesion in the RIGHT MAINSTEM BRONCHUS

This prevents ventilation of right lung and results in alveolar collapse

Which is why trachea shifts to right

Front 61

Why do macrosomic babies experience transient hypoglycemia?

Back 61

Neonates of diabetic moms exposed to high maternal glucose levels in utero

Develop compensatory insulin hypersecretion (results in macrosomia) and can cause hypoglycemia

NOTE THAT MATERNAL INSULIN DOES NOT CROSS PLACENTA

Front 62

Which vasodilators are specific to coronary vessels?

Back 62

Adenosine
Dipyridamole

Front 63

What metabolic (pH status) abnormality can be better elucidated by measuring urinary Chloride?

Why?

Back 63

Metabolic alkalosis

If losing hydrogen ions form vomiting/nasogastric suction-->serum Cl- decreases and leads to decrease in urinary Cl-

If due to thiazides or loop diuretics-->inc'd renal loss of Na, followed by excretion of Cl-
Reabsorption of HCO3 maintains electrical neutrality

Front 64

What is this most likely to be?

Back 64

Metastases to liver (multifocal) from another primary site (breast, lung, colon)

NOT hepatocellular carcinoma (that would be in someone with HBV or HCV)

Front 65

What type of diverticula (true/false) is due to pulsion?

Back 65

Pulsion = straining (like BM)

Will form FALSE diverticulum (mucosa and submucosa only)

Front 66

What is the effect of a chronic arteriovenous shunt on cardiac output?

Why?

Back 66

Inc'd cardiact output because of inc'd sympathetic stimulation to heart, dec'd total peripheral resistance, inc'd venous return

Front 67

What is the effect of phenylephrine infusion on cardiac output?

Back 67

Increases sympathetic tone-->vasoconstriction, inc'd total peripheral resistance

Thus a decrease in cardiac output with no change in blood volumes or venous return

Front 68

Euchromatin vs Heterochromatin:
Which is methylated?

Back 68

Heterochromatin is methylated (low transcriptional activity)

Front 69

Effect of histone acetylation on transcriptional activity.

Back 69

Histone acetylation forms euchromatin with high transcriptional activity

Front 70

Why should chest expansion be monitored in a patient with ankylosing spondylitis?

Back 70

Inflammation of costovertabral and costosternal junctions leading to pain which can limit ches wall expansion-->hypoventilation

Other things to watch at for are uveitis, and ascending aortitis

Front 71

Describe the ion changes (concentrations) that digoxin causes in cardiac myocytes.

Back 71

Digoxin inhibits Na-K-ATPase

This increases intracellular sodium
Decreasing gradient that drives Na-Ca transporter, which leads to inc'd calcium in the cell
The greater the concentration of calcium in the cell, the greater the contraction will be

Remember that contraction occurs when sodium and calcium enters the cell, and potassium exits

Front 72

Organism that is gram positive and bile soluble.

Back 72

Strep pneumo

Front 73

Oseltamivir:
MOA (not protease inhibit)
Effects on virus it acts on

Back 73

Neuraminidase inhibitor useful in treatment of influenza A and B

Neuraminidase is req'd for release of virus from infected cells and spread via respiratory tract

This drug causes newly synthesized virions to adhere to host cell surface and form viral aggregates (thereby reducing spread of virus)

Front 74

Acyclovir vs Ganciclovir:
Uses

Back 74

Acyclovir is used for herpes

Ganciclovir is used for CMV (esp CMV retinitis)

Front 75

What is the most likely outcome for a patient with HCV?

Back 75

Stable chronic hepatitis (followed closely by chronic hepatitis progressing to cirrhosis)

Front 76

23 year-pld male
Returned from trip abroad
White spots over suntanned skin
KOH prep shows spaghetti and meatball appearance

Back 76

This is tinea versivolor aka pityriasis versicolor

Caused by Malassezia FURFUR

Front 77

Anti-viral causing neutropenia

Back 77

Ganciclovir

Front 78

Anti-viral causing bone marrow suppression

Back 78

Zidovudine (anemia, granulocytopenia)

Front 79

How exactly does HbS result in sickling?

Back 79

Valine (neutral) in place of glutamic acid promotes hydrophobic interaction among hemoglobin molecules and results in polymerization of HbS molecules and RBC distortion

Front 80

In healthy individuals, PaCO2 is the major stimulator of respiration (via central chemoreceptors).

How does this change in those with COPD?

Back 80

In prolonged hypercapnia (smokers for example), high PaCO2 ceases to stimulate respiratory drive.

Respiration is instead stimulated by hypoxia (low PaCO2) sensed by peripheral chemoreceptors.

Front 81

Needle-shaped, negatively birefringent crystals

What is their chemical composition?

Back 81

Monosodium urate (not uric acid!!!)

Front 82

Describe the path of CSF beginning with lateral ventricles.

Back 82

LV
Intraventricular foramen of Monro
Third Ventricle
Cerebral Aqueduct
Fourth Ventricle
Foramen of Magendie/Luschka
Subarachnoid Space

Front 83

What slows the late onset of hemochromatosis in women?

Back 83

MENSTRUATION
MENSTRUATION
MENSTRUATION

Front 84

Hypoglycemia after prolonged fasting
Low ketone levels

What process is failing to occur?
RLS of this process?

Back 84

Impaired beta-oxidation of FAs

Acyl-CoA dehydrogenase catalyzes the first step in beta-oxidation

Front 85

What is avascular necrosis (of bone) and when does it occur?

Back 85

Impaired blood supply to segment of bone

Femoral head is most common location

Occurs most commonly due to SICKLE CELL, steroid tx, SLE, EtOH

Presents with acute onset hip pain exacerbated by weight bearing

No swelling, erythema, temp change

Front 86

First-line treatment of essential tremor.

Back 86

Propanolol

Front 87

Murmurs that diminish on squatting

Back 87

HCM
MVP

Front 88

__________ degeneration can result in mitral valve prolapse.

Back 88

Myxomatous (Connective Tissue) changes can result in mitral valve prolapse--thought to stretch valve leaflets

Front 89

Which bacteria are able to undergo transformation?

What is transformation?

Back 89

SHiN bacteria can transform:

It involves uptake of chromosomal fragments from media--allows non-virulent, non-capsule forming strains to acquire genetic material that codes for capsule and thus gain virulence

Front 90

Which bacteria are able to undergo conjugation?

What is conjugation?

Back 90

Conjugation is pilus-mediated transfer of DNA

Occurs in most bacteria, but first described in E. coli

Front 91

Via what 'exchange mechanism' are bacterial able to acquire genes for virulence and antibiotic resistance?

Back 91

Transduction--whereby a bacteriophage (Virus) transfers DNA from one bacterium to another.

Front 92

Rhomboid crystals with weak positive birefringence
Extracted from knee

Back 92

THis is calcium PYROPHOSPHATE

Not calcium oxalate; calcium oxalate occurs in renal calculi

Front 93

Amyloid deposition isolated to a single organ doesn't necessarily form from beta-amyloid protein.

Name the precursors to amyloid formation for:
Cardiac Atria
Thyroid
Pancreatic Islets
Cerebrum/Cerebral vessels
Pituitary Gland

Back 93

Cardiac atria: ANP
Thyroid gland: Calcitonin
Pancreatic islets: islet amyloid protein (amylin)
Cerebrum/cerebral blood vessels: beta-amyloid protein
Pituitary gland: Prolactin

Front 94

Bluish neoplasm under nail bed:
Differential

Back 94

Glomangioma (tumor of glombus body--responsible for shunting blood away from skin surfaces in cold temperatures to prevent heat loss)

Melanoma (function of pigmentation)

Front 95

Recent-onset oliguria
Elevated serum creatinine
Intranasal ulcer failing to heal
Sinusitis, hemoptysis

Diagnosis

Back 95

This is Wegener's granulomatosis (with polyangitis)

Disease is associated with C-ANCAs (antibodies targeting neutrophils!)

Front 96

21 year-old male
recurrent kidney stones
Sodium cyanide added to urine following sodium nitroprusside and urine turns red-purple

What is going on in this patient?

Back 96

Sodium cyanide-nitroprusside test detects cystine's sulfhydryl groups

He is peeing out cysteine (aminoaciduria)--results in recurrent stone formation from a young age