Blocks 41, 42 Flashcards Preview

UWORLD STEP 1 > Blocks 41, 42 > Flashcards

Flashcards in Blocks 41, 42 Deck (89):
1

What interleukin REDUCES the production of pro-inflammatory Th1 cytokines (IL-2 and IFN gamma) and MHC-2 expression? (therefore it has anti-inflammatory properties)

IL-10

2

In a case of suspected or proven C. diff infection, what contact precautions are observed?

Handwashing

Gowns

Nonsterile gloves

3

Classic presentation: male infant with abdominal contents protruding through deep inguinal ring and traveling lateral to inferior epigastric vessels

Indirect Inguinal Hernia

Patent processus vaginalis

4

Classic presentation: Older man with abdominal contents protruding through Hesselbach triangle traveling medial to inferior epigastric vessels.

Direct Inguinal Hernia

Weakness of transversalis fascia

5

Classic presentation: Woman with abdominal contents protruding through femoral ring and traveling inferior to inguinal ligament.

Femoral Hernia

Weakness of proximal femoral canal

6

4 y/o boy with severe staph pneumonia. History of recurrent lymphadenitis and skin infections. Dihydrorhodamine flow cytometry testing reveals an absence of the green flurourescence that is characteristic of neutrophils. What is the disease?

Chronic Granulomatous Disease

Lack of NADPH oxidase

7

Amphotericin B is an antifungal drug notorious for what toxicity?

Renal toxicity

Severe hypokalemia and hypomagnesemia are commonly seen during therapy and often require daily supplementation.

8

Newborn with fetal growth retardation. Low set ears, small mandible, prominent occiput. Weak cry with increased tone of the extremities, clenched hands with overlapping fingers. Harsh holosystolic murmur heard best at the left sternal border.

Trisomy 18

Edwards Syndrome

47, XX, +18

9

Acute dystonic reaction (spasmodic torticollis) is a type of extrapyramidal symptom most likely due to initiation of what type of medication?

Antipsychotic Medication

Antagonism of dopaminergic D2 receptors in the nigrostriatal pathway

10

Citalopram is what type of drug?

SSRI

11

What drugs are first line therapy for generalized anxiety disorder?

SSRI

SNRI

12

Alcoholic male with hematemesis. Longitudinal mucosal tears at the gastroesophageal junction.

Mallory-Weiss Syndrome

Secondary to rapid increase of intraabdominal and intraluminal gastric pressure, like when retching.

13

What are the effects of insulin on the body?

Increases peripheral glucose uptake

Inhibits lipolysis

Inhibits ketoacid formation

Suppresses glucagon release

14

Pt with progressive dyspnea, fine crackles, clubbing, and diffuse reticular opacities

Interstitial Lung Disease

Fibrotic interstitial tissue --> Decreased lung volumes --> Increased lung elastic recoil --> Increased radial traction (outward pulling)

 

Increased expiratory flow rates when corrected for the low lung volume

 

15

Elastin fibers within alveolar walls normally allow the lung to stretch during active inspiration and recoil during passive expiration.  What property of elastin allows this?

Extensive cross-linking between elastin monomers, facilitated by lysyl oxidase.

16

Arthritis with brief or no morning stiffness (<30 min), hard, bony enlargment of joints, knees, hips, DIP joint, increases with age

Osteoarthritis

DIP = Heberden node

PIP = Bouchard node

17

Arthritis with prolonged morning stiffness, soft/spongy warm joints, MCP joint, PIP joint, wrists, fever, fatigue, weight loss

Rheumatoid Arthritis

18

A patient with TB is given a drug and then has symptoms including progressive limitation of physical activity due to fatigue. Conjunctival and palmar pallor. Hemoglobin is low, MCV is low, Hematocrit is low. Blood smear shows ringed sideroblasts. What is going on?

Isoniazid inhibits pyridoxine phosphokinase, leading to pyridoxine (B6) deficiency. Pyridoxine's active form is the cofactor for delta-aminolevulinate (ALA) synthase, the enzyme that catalyzes the rate-limiting step of heme synthesis. Inhibition of this step can produce microcytic, hypochromic anemia. Iron transported to developing erythrocytes that cannot form heme, accumulate and  result in sideroblastic anemia.

19

Pt with severe HTN at a young age, weakness and parasthesias, suppressed plasma renin

Primary Mineralocorticoid Excess (Hyperaldosteronism)

Hypokalemia

Increased H+ excretion --> increase in bicarb --> metabolic alkalosis

Normal sodium levels

20

Lesion of what hypothalamic nucleus will cause hyperphagia and obesity?

Ventromedial

21

Lesion of what hypothalamic nuclei causes anorexia?

Lateral

22

How do you calculate RBF?

RBF = PAH clearance / (1- hematocrit)

23

Stenosis characterized by diffuse fibrous thickening and distortion of the mitral valve leaflets along with commissural fusion at the leaflet edges is caused by what?

Rheumatic Mitral Stenosis

24

Hyponatremia + a lung mass

SIADH

Euvolemic hyponatremia

Profound hyponatremia can cause headache, weakness, altered mental status, and seizures.

25

The individual subunits of the hemoglobin molecule are structurally analagous to what molecule?

Myoglobin

Hyperbolic oxygen-dissociation curve (like myoglobin)

26

What should be administered following nuclear accidents when material like iodine-131 is involved?

Potassium iodide

It competitvely inhibits thyroid uptake of radioactive iodine isotopes to prevent development of radiation-induced thyroid carcinoma.

27

Right ventricular myocardial infarction presents with hypotension, elevated jugular venous pressure, and clear lungs. It most often occurs in the setting of acute inferior wall myocardial infarction. What are the hemodynamic values?

Elevated right atrial and central venous pressures

Reduced pulmonary capillary wedge pressure

Reduced cardiac output

28

A skin biopsy from the thigh of a child demonstrates vascular lesions with IgA and C3 deposition. What is this presentation?

Henoch-Schonlein Purpura

Purpuric skin rash + colicky abdominal pain + polyarthralgia

Acute glomerulonephritis is a potential complication.

MC males 3-11 years old

29

What is the medical therapy to dissolve cholesterol gallstones in patients refusing surgery?

Hydrophilic bile acids

They will decrease biliary cholesterol secretion and increase biliary bile acid concentration, improving cholesterol solubility.

30

What should you think of if a person's Hemoglobin A2 level is 7.5% (normal 1.5-3.5%)

Beta-thalassemia trait

31

Antiviral medications like Acyclovir, Valacyclovir, Famciclovir, and Ganciclovir have to undergo what in order to be active?

Monophosphorylation by a viral thymidine kinase (rate-limiting) to convert into the active triphosphate form.

32

Some patients who are given Tamoxifen as therapy for hormone receptor positive, early stage breast cancer show lower serum concentrations of the active metabolites and therefore are more likely to relapse. Why?

Tamoxifen is a prodrug metabolized by CYP2D to its active metabolite, endoxifen. Patients with genetic polymorphisms resulting in poor CYP2D activity are exposed to decreased levels of the active metabolite and have a higher risk of disease relapse.

33

What antifungal drugs are inhibited by liver cytochrome P450?

Azoles

34

A common pediatric elbow fracture occurs after hyperflexion or hyperextension injuries (falling on an outstretched arm) is a supracondylar hymeral fracture. What structures can be injured?

Anterolateral = radial nerve

Anteromedial = brachial artery, median nerve

35

Fracture of the orbital floor commonly results from direct frontal trauma to the orbit. What will be the symptoms?

Infraorbital nerve - parasthesia of the upper cheek, upper lip, and upper gingiva

Inferior rectus - limit vertical gaze

36

Meckel diverticulum contains what type of tissue? (general term)

Ectopic Tissue

Gastric epithelium, pancreatic tissue

37

Fever, maculopapular rash, and symptoms of acute renal failure 1-3 weeks after beginning treatment with a beta-lactam antibiotic or other specific drugs (quinolone) are highly suggestive of what?

 

Acute Interstitial Nephritis

Many pts. will have increased levels of eosinophils and IgE in serum

38

What is a good drug to give to an elderly patient with sleep issues which will not lead to addiction?

Zolpidem

Short acting hypnotic chemically unrelated to benzodiazepines. Same MOA but a much lower risk of tolerance and dependence.

39

The simultaneous development of stroke, intestinal or foot ischemia, and renal infarction should raise suspicion for what?

Embolic phenomena

40

What is the adenoma to carcinoma sequence?

1. Normal mucosa to a small polyp (APC tumor suppressor gene mutation)

2. Increased size of the polyps (K-RAS protooncogene mutation)

3. Malignant transformation (p53 and DCC mutations)

41

3 y/o boy with recurrent skin rashes. Erythematous intense itching rash on his cheeks, trunk, and arms about 5 or 6 times a year. Related to the consumption of certain foods.

Atopic Dermatitis (eczema)

Associated with other atopic diseases like allergic rhinitis and asthma.

42

Proximal muscle weakness (gait alteration, difficulty standing from a chair or climbing stairs), cranial nerve involvement (diplopia, ptosis, dysarthria, dysphagia), and autonomic symptoms (dry mouth, impotence)

Lambert-Eaton Myasthenic syndrome

Antibodies directed against the voltage gated calcium channels that participate in ACh release.

43

Adult males presents with persistent fever, bleeding gums, and a sore throat. Peripheral blood findings are shown:

Several Myeloblasts with large number of coarse rod-shaped intracytoplasmic granules (Auer rods) that stain for peroxidase.

AML

Acute Promyelocytic Leukemia has abundant auer rods

 

44

Classic presentation: anemia (fatigue, pallor), thrombocytopenia (petechiae, hemorrhages), and neutropenia (fever, opportunistic infections)

Acute Myelogenous Leukemia 

Marrow replacement by leukemic cells

45

Maintenance of blood glucose can be facilitated by hepatic conversion of pyruvate into glucose. What substance is an allosteric activator of the first step of the process?

Acetyl CoA is an allosteric activator of pyruvate carboxylase

(Pyruvate --> Oxaloacetate)

46

Newborn with jaundice, hepatomegaly, and generalized edema. Hemoglobin is 6, positive direct Coombs test. Peripheral blood smear shows nucleated erythrocytes. Baby is in severe respiratory distress due to pleural effusions and ascites and dies. Autopsy shows extramedullary hematopoiesis. What happened?

Erythrocyte opsonization by maternal antibodies

Hemolytic disease of the newborn

47

Hemolytic disease of the newborn happens with what type of Rh in mom and baby?

Rh - mom

Rh + baby

Mom makes anti-Rh IgG antibodies

48

Pt. with night sweats, weight loss, cough, and apical pulmonary granulomas showing caseous necrosis (large epithelioid macrophages with pale pink granular cytoplasm surrounding a central region of necrotic debris). What is the diagnosis? What surface marker is present on the large cells with abundant cytoplasm surrounding the necrotic area?

Secondary TB

CD14

49

Winged scapula is damage to what?

Paralysis of serratus anterior muscle due to long thoracic nerve injury

50

What are ways the long thoracic nerve can be damaged?

Penetrating trauma

Iatrogenically during axillary lymph node dissection

Chest tube insertion

51

What are the tumor necrosis factor-alpha inhibitors and what is the MOA?

Etanercept, Infliximab, Adalimumab

Large molecule anti-inflammatory agents (biologics) that impair cell-mediated immunity by binding to and blocking the actions of TNF-alpha

52

What must be checked before starting treatment with a biologic?

TB test

Latent TB can be reactivated and the risk of disseminated disease will increase.

53

Hereditary hemachromatosis is characterized by what?

AR
Excessive intestinal iron absorption and accumulation within parenchymal tissues resulting in end-organ damage (cirrhosis, diabetes, cardiomyopathy, arthropathy)

Missense mutation of the HFE gene

Commonly in caucasions

54

How does the HFE protein work? (hemachromatosis = when it messes up) What is the result when it is messed up? (2 mechanisms)

HFE protein interacts with the transferrin receptor on the cell surface to facilitate endocytosis of the iron-transferrin complex.

When messed up, enhanced iron accumulation in the body via:

1. Enterocytes increase apical expression of DMT1, increasing intestinal iron absorption from the lumen.

2. Hepatocytes decrease hepcidin synthesis, which increases ferroportin expression on the basolateral surface of enterocytes and promotes iron secretion into the circulation.

55

A patient experiencing medication-induced dystonia is likely due to motor neuron hyperactivity. The persistent myocyte stimulation causes a substance to be released from the SR which most likely binds to which protein?

Calcium --> binds to Troponin C on thin filaments which induces a conformational change in the troponin complex causing it to displace tropomyosin and expose myosin binding sites on actin filaments.

56

Compression of which renal vein can lead to a varicocele? Why only one side?

Left

"nutcracker effect" - it can cause hematuria and flank pain

The right gonadal vein drains directly into the IVC while the left gonadal vein drains into the left renal vein which lies between the Aorta and the SMA leading to increased chance of compression.

57

Is sickle cell anemia AD or AR?

AR

58

Carbon monoxide binds heme iron in hemoglobin with an affinity much greater than oxygen, generating carboxyhemoglobin. Why does this lead to decreased oxygen in tissues?

The remainding binding sites on carboxyhemoglobin have an increased affinity for oxygen that causes the oxygen dissociation curve to shift to the left, impeding oxygen delivery to tissues.

59

What are the levels of TSH, T4, and T3 in hypothyroidism caused by autoimmune destruction of the thyroid gland (hashimoto)? Why?

Low T4

Elevated TSH (loss of feedback inhibition)

Normal T3 until later in disease progression (because it is converted from T4 in peripheral tissues)

60

30 y/o woman with mild fatigue, cold intolerance, constipation, dry skin, weight gain, myalgias, delayed ankle jerk reflexes, bradycardia. Mild diffuse enlargment of thyroid gland with no tenderness or nodules.

Hypothyroidism

Most common cause in the US is hashimoto thyroiditis (autoimmune destruction of gland)

61

3 day old child with poor feeding, bilious emesis, and lethargy. Afebrile and normotensive but tachycardic and tachypneic. Appears dehydrated with a distended abdomen. On laparotomy, fibrous bands are seen extending from the cecum and right colon to the retroperitoneum, causing extrinsic compression of the duodenum. What went wrong embryologically?

Incomplete counterclockwise rotation will result in midgut malrotation. The cecum will rest in the RUQ instead of the RLQ. Ladd's (fibrous) bands connect the retroperitoneum in the RLQ to the right colon/cecum by passing over the second part of the duodenum, causing intestinal obstruction in the process.

Because the mesenteric base is abnormally narrowed, the mesentery is vulnerable to twisting around the SMA.

62

80% of malignancy induced hypercalcemia is caused by what?

PTHrP production --> activated PTH receptor --> excessive bone resorption

63

What are other mechanisms of hyperalcemia related to malignancy (not the most common form)?

Lymphomas --> 1, 25 (OH)2 vit D production --> excessive gut absorption of calcium

Bone mets --> release of local factors (cytokines) to stimulate bone resorption

Ectopic PTH production --> bone resorption (RARE)

64

A penetrating stab wound laterally directed at the 5th intercostal space at the left anterior midclavicular line would most likely injure what?

Left lung

65

MOA of Zidovudine (AZT)

Nucleoside reverse transcriptase inhibitor that competitively binds to reverse transcriptase and is incorporated into the viral genome as a thymidine analog. Since AZT does not have a 3'-OH group, making a 3'-5' phosphodiester bond is impossible.

66

Knee pain in a young adolescent athlete after a recent growth spurt. Pain and swelling. Relieved by rest but can be reproduced by straightening out the knee (use of the quadricep).

Osgood-Schlatter disease (OSD) is an overuse injury of the secondary ossification center (apophysis) of the tibial tubercle, the insertion point for the patellar ligament.

67

Young african american woman with fatigue, exertional dyspnea, cough, subjective fevers, nontender cervical LAD, scattered nodules and parenchymal infiltrates, and noncaseating granulomas. What does she have? What lab value will be elevated and why?

Sarcoidosis

Hypercalcemia due to 1-alpha-hydroxylase expression in activated macrophages in the lung and lymph nodes cause PTH-independent production of 1,25-dihydroxyvitamin D --> increased intestinal absorption of calcium

68

Classic presentation: loud first heart sound (S1), an early diastolic high-frequency opening snap after the second heart sound (S2), and a low pitched diastolic rumble. Best heard at the apex using the bell with patient lying on left side in held expiration.

Mitral Stenosis

69

Hyperparakeratosis, acanthosis, elongation of the rete ridges, mitotic activity above the epidermal basal cell layer, and a reduced or absent stratum granulosum. Epidermal layer superior to the dermal papillae may be thinned and contain dilated blood vessels. Neutrophils may form spongiotic clusters in the superficial dermis and the parakeratotic stratum corneum.

Psoriasis

70

DOC for myoclonic seizures that can also be used for manic episodes of bipolar disorder?

Valproate

71

What is used to treat androgenetic alopecia (male-pattern hair loss)?

5-alpha-reductase inhibitors (Finasteride) decrease the conversion of testosterone to DHT and are effective because the hair loss is caused by the susceptibility of hair follicles to shrink due to androgenic hormones.

72

Adult presenting with meningitis with elevated opening pressure, increased neutrophils, decreased glucose, and elevated protein = what type of meningititis? What is the most likely cause?

Bacterial

Strep Pneumo

73

16 y/o boy with tremor in both hands, unsteady broad based gait, poor appetite, impulsive and moody behavior, sleeping too much, elevated serum transaminases and a low serum ceruloplasmin. What is the diagnosis? What is the treatment?

Wilson Disease

AR mutation of ATP7B gene resulting in hepatic copper accumulation. 

Kayser-Fleischer rings may be present in eyes.

Treat = D-penicillamine

74

Baby has hypoglycemia 1 hour after birth from a mother with gestational diabetes. What is causing the baby's hypoglycemia?

Chronic stimulation of fetal beta cells leads to beta cell hyperplasia and hyperinsulinism. Elevated insulin levels lead to increased fat deposition and enhanced fetal growth, resulting in macrosomia.

75

The onset of action of a gas anesthetic depends on what?

Blood/gas partition coefficient

(It's solubility in the blood)

A high blood/gas coefficient = more soluble in blood, slower equilibrium with brain, longer onset time

76

Intense mononuclear infiltrate consisting of lymphocytes and plasma cells, often with germinal centers. Residual follicles surrounded by large oxyphilic cells filled with granular cytoplasm (hurthle cells), which represent follicular epithelial cells that have undergone metaplastic change in response to inflammation.

Hashimoto Thyroiditis

77

NSAID-associated chronic renal injury (modest elevation in serum creatinine, mild proteinuria, evidence of tubular dysfunction like polyuria or nocturia)is morphologically characterized by what?

Chronic interstitial nephritis and papillary necrosis

78

Both diffuse and limited forms of systemic sclerosis variants develop due to increased deposition of what? Where is the first place?

Deposition of collagen in tissues triggered by increased proliferation and accumulation of monoclonal T cells in the affected tissues that secrete a variety of cytokines (esp TGF-beta), which increase production of collagen and extracellular matrix proteins by fibroblasts.

Earliest damage is seen in small arterioles and capillaries

79

45 y/o woman with progressive exertional dyspnea and fatigue. Episodic pain and bluish discoloration of fingers and toes on cold exposure that improves with warming. Tightened skin over fingers. Accentuated second heart sound over upper left sternal border. Mild hepatomegaly. Bilateral lower extremity pitting edema. 

CREST syndrome:

elevated pulmonary artery pressure

sclerodactyly

Raynauds

 

*Pulmonary HTN is a common complication*

80

Exophytic colon mass

Occult bleeding

Symptoms of iron deficiency anemia

Right-sided colon cancer

81

Constipation

Symptoms of intestinal obstruction

(what side is colon cancer?)

Left-sided colon cancer

82

What drugs are useful for treating both BPH and Hypertension?

Alpha-1-blockers

Doxazosin

Prazosin

Terazosin

83

What drugs is the first line medication used for essential HTN in the general population?

Hydrochlorothiazide

84

Patients with CAD and heart failure along with HTN will benefit from what type of drug?

Cardioselective beta-blockers

85

DOC for pt with diabetes and HTN

ACE Inhibitor

86

Patients who receive the equivalent of more than one body blood volume (5-6 liters) of whole blood transfusions or packed RBCs over a period of 24 hours may develop elevated plasma levels of what? What is the result?

Citrate (a substance added to stored blood)

Citrate chelates calcium and magnesium and may reduce their plasma levels, causing parasthesias.

87

38 y/o man with blood stools, weight loss, anemia, right-sided abdominal tenderness, right-sided ulcerative mass which is found to be adenocarcinoma. Father died of colon cancer at 40 and sister has endometrial cancer. What does he have and what is the gene mutated?

Colorectal cancer likely due to Lynch Syndrome (hereditary nonpoluposis colon cancer) because of his family history. 

Lynch = colorectal, endometrial, ovarian

Genes = MSH2, MLH1, MSH6, PMS2

88

In a patient with obstructive sleep apnea, why would hematocrit be increased?

Renal cortical cells sense hypoxia and respond by synthesizing and releasing erythropoietin --> stimulates production of erythrocytes in the bone marrow

89

Why must a patient wait 2 weeks after discontinuing an MAOI before starting an SSRI?

To avoid excess synaptic serotonin levels.

Must allow MAO to regenerate