Blocks 39, 40 Flashcards Preview

UWORLD STEP 1 > Blocks 39, 40 > Flashcards

Flashcards in Blocks 39, 40 Deck (69):
1

Kartagener Syndrome

1. Chronic cough, chronic sinusitis, recurrent otitis media, bronchiectasis

2. Situs inversus

3. Infertility due to sperm immotility, and immobility of fallopian tube cilia

2

Exchange of genetic information between 2 virus strains that have nonsegmented, double stranded DNA genomes

Recombination - via crossing over within homologous regions

3

Combination therapy with Simvastatin and Cholestyramine has what beneficial effect?

Synergistic reduction in plasma LDL level

Simvastatin - decreases hepatic cholesterol production

Cholestyramine - increases hepatic cholesterol and bile acid synthesis

4

When actin-containing fibroblasts and increased metalloproteinase activity are detected in a laceration, what is happening?

Contractures may occur when unusually pronounced MMP activity results in excessive wound contraction.

5

Which monosaccharide will have the fastest rate of metabolism in the glycolytic pathway? Why?

Fructose

It is the only one whose metabolites bypass PFK-1 (the rate limiting enzyme).

6

Minutes to hours after starting a blood transfusion: fever chills, hypotension, dyspnea, chest and/or back pain, and hemoglobinuria (red to brown colored urine).

Acute Hemolytic Transfusion Reaction

Antibody mediated type 2 hypersensitivity rxn

Complement mediated cell lysis

7

Irritable mood, hyperactivity, pressure speech, decreased need for sleep, and gradiose delusions.

Manic episode

These can occur with or without psychotic features (delusions, hallucinations)

8

Patients with one or more lifetime manic episodes are diagnosed with what?

Bipolar 1 Disorder

 

9

Painless, indurated granulomatous lesions that progress to white-gray rubbery lesions that may ulcerate (in the setting of syphilis)

Gumma

10

8 y/o boy with one week of rapid and irregular movements of his hands. Unintentional funny faces and has trouble controlling the volume of his voice. Temp = 102. New 3/6 systolic murmur and several circular, faintly erythematous lesions on his abdomen.

Acute Rheumatic Fever

Cross-reactivity of antibodies against bacterial and host antigens.

Murmur is likely acute mitral regurgitation from pancarditis. Pts. often have sudden changes in pitch and volume. Sydenham chorea = non-rhythmic movements of hands, feet, and face. Erythema marginatum presents as faintly erythematous, circular lesions with central clearing that come and go on the trunk and extremeties

11

What ulcers are rarely malignant and do no require biopsy?

Duodenal ulcers

12

Pt. that has been to Africa has 6 days of fatigue and intermittent fever. Blood microscopy shows:

Plasmodium Falciparum

RBCs with multiple small rings called trophozoites and also banana-shaped gametocytes (not shown)

Treat = Chloroquine or Mefloquine if resistant

13

Third diastolic heart sound (S3) in a pt. over 40 suggests what? How can you make it louder?

Ventricular enlargement

Best heard with the bel over the apex while pt. is in left lateral decubitus position and at the end of expiration.

14

What type of receptors contain zinc finger binding domains?

Intracellular receptors that bind steroids, thyroid hormone, and fat-soluble vitamins and act directly as transcription factors.

15

Injury at the neck of the fibula affects what nerve? Signs?

Common peroneal (fibular) Nerve

Weakness of dorsiflexion, eversion of foot, lost sensation over dorsum of the foot

16

Contralateral hemiplegia of the face (possible sparing the forehead) and upper limb with relative sparing of the lower limb can be from an occlusion of what artery?

MCA

17

What autoantibodies are commonly seen with SLE?

ANA (antinuclear)

Anti-dsDNA

Anti-snRNPs (anti-smith)

18

Left ventricular leads in biventricular pacemakers course through the coronary sinus which rides where?

In the atrioventricular groove on the posterior aspect of the heart

19

A developmental anomaly characterized by hypoplasia/absence of the cerebellar vermis and cystic dilation of the 4th ventricle with posterior fossa enlargement. Pt. presents during infancy with developmental delay and progressive skull enlargement, unsteadiness and imparied muscle coordination.

Dandy-Walker Malformation

If non-communicating hydrocephalus occurs, pts. can have symptoms of high ICP like irritability and vominting.

20

Downward displacement of the cerebellar vermis and tonsils below the foramen magnum.

Arnold-Chiari Malformation

21

What is the most sensitive screen test for diagnosing primary hypothyroidism?

Serum TSH

22

Pt. with fatigue, bradycardia, wt. gain, constipation, and slowed relaxation of deep tendon reflexes likely has what?

Hypothyroidism

23

Atherosclerosis is initiated by what?

Repetitive endothelial cell injury, which leads to a chronic inflammatory state in the underlying intima of large elastic arteries as well as large and medium-size muscular arteries.

24

Leuprolide is a GnRH agonist that causes what to happen in patients if give continuously?

Transient increase in pituitary LH secretion, which leads to a rise in testosterone levels. Over time it will suppress LH release and decrease testosterone production.

25

What is the earliest manifestation of diabetic neuropathy?

Increased albuminuria

26

Pt. presents with diabetes complicated by neuropathy and nephropathy. Moderately increased albuminuria. In addition to antihyperglycemic treatment, what other pharmacotherapy should be started?

ACEI or ARB

Preferred antihypertensive agents due to their BP independent anti-proteinuric effects.

 

The risk of progression of diabetic nephropathy in patients with proteinuria can be reduced by appropriate glycemic and BP control.

27

What drug will increase cardiac contractility by acting on mycardial beta 1 adrenergic receptors and cause decreased vascular resistance and mean arterial blood pressure by binding to beta 2 adrenergic receptors?

Isoproterenol

Nonselective beta adrenergic agonist

28

A pt. with persisten bronchial asthma (chronic airway inflammation and edema leading to bronchial wall thickening and remodeling) will benefit most from long term use of what type of medication?

Glucocorticoids

Pronounced anti-inflammatory effects on respiratory epithelium. Inhibit formation of inflammatory mediators. Reduce leukocyte extravasation and induce apoptosis of inflammatory cells. Decrease the amount of mucus produced by goblet cells.

29

Attached ribosomes (to the RER) synthesize what type of products?

Secretory proteins

Integral membran proteins of nucleus AND cell membrane

Proteins within the ER, Golgi network, and Lysosomes

30

Smooth ER functions in what way?

Lipid synthesis

Carbohydrate metabolism

Detoxification of harmful substances

31

Free ribosomes floating in the cytosol make what?

Proteins within the cytosol, nucleosol, peroxisome matrix, and nuclear-encoded mitochondrial proteins

32

What is the central disturbance in SLE?

Excessive autoantibody production due to loss of self-tolerance. Autoantibody binding to self-antigens leads to the formation of circulating immune complexes that deposit in various organs and can cause complement activation. ACTIVE SLE is therefore characterized by consumption of complement with reduced serum complement levels.

33

Contact dermatitis like poison ivy is what type of reaction?

Type 4 (delayed type) hypersensitivity

CD8 T cells are the primary effector cells

34

Xanthine Oxidase catalyzes 1 of 2 major inactivating pathways of what drug?

Azathioprine

Therefore, allopurinol use with azathioprine will increase the conversion of azathioprine to it's active metabolites.

35

Prolactinomas develop from lactotroph cells in the anterior pituitary, which is a derivative of what embryonic structure?

Surface Ectoderm

36

Select a group of people, determine their exposure status, and then follow them over time for development of the disease of interest. What type of study is this?

Prospective Cohort Study

37

Child with progressive gait ataxia, impaired joint and vibration sense, spastic muscle weakness and a + Babinski can be present. Other issues can be Kyphoscoliosis, pes cavus, diabetes mellitus, and hypertrophic cardiomyopathy.

Friedreich Ataxia

AR

Degeneration of spinocerebellar tracts, posterior columns, dorsal root ganglia

38

What is the outcome of a 46, XY genotype with testes and normally functioning Leydig cells but a total absence of Sertoli cells?

Both male and female internal genitalia and male external genitalia

Sertoli cells secrete the mullerian inhibiting factor (MIF) which causes the involution of paramesonephric ducts.

39

What is the power of a study and how do you calculate it?

Power is the ability of a study to detect a difference between groups when such a difference truly exists.

Power = 1 - beta

Beta = type 2 error (probability of concluding there is no difference between groups when one truly exists)

40

Corynebacterium diptheriae causes diptheria via it's A/B exotoxin. How does it work?

The B (binding) subunit allows penetration of the A (active) subunit into the cell to inhibit ribosome function.

41

Immunization for Corynebacterium diptheria 

Immunization with diptheria toxoid induces production of circulating IgG against the exotoxin B subunit, effectively preventing disease.

42

Nodule in one lobe of the thyroid. FNA reveals large overlapping nuclei containing finely dispersed chromatin. Numerous intranuclear inclusions and grooves. Laminated calcium deposits are also present.

Papillary Carcinoma = most commin type of thyroid cancer

Orphan Annie eye

Psammoma bodies

43

Eczema

Thrombocytopenia

Combined B-lymphocyte and T-lymphocyte deficiency (recurrent infections)

Wiskott-Aldrich Syndrome

Mutation on the X chromosome (only in males)

Treatment = HLA-matched bone marrow transplantation

44

In liver disease, what lab value is the first to become abnormal (in terms of coagulation)?

Prothrombin time = extrinsic and common pathways of coagulation

Failure of PT improvement with vitamin K supplementation means there is a factor 7 deficiency.

Factor 7 has the shortest-half life of all the coag factors.

 

45

Polyethylene glycol is an osmotic laxative commonly used to treat constipation in the elderly. Diarrhea associated with what other disorder is similar?

Lactase deficiency which is osmotic and occurs due to accumulation of nonabsorbable lactose

46

Enteropeptidase is a jejunal brush border enzyme responsible for activating what? Deficiency leads to what?

Trypsin

Deficiency leads to protein and fat malabsorption. Diarrhea, failure to thrive, and edema (due to hypoproteinemia)

47

Hypertrophic Cardiomyopathy is an AD genetic disorder of cardiac myocytes caused by mutations in what?

Several sarcomere genes encoding myocardial contractile proteins. 

Common mutations include single-point missense mutations in the genes for beta-myosin heavy chain and myosin binding protein C

48

Integral membrane proteins contain transmembrane domains composed of what?

Alpha helices with hydrophobic amino acid residues (alanine, valine, leucine, isoleucine, phenylalanine, tryptophan, methionine, proline, and glycine)

49

During times of starvation, what is found in adipose tissue and functions to drive the breakdown of stored triglycerides into free fatty acids and glycerol for hepatic gluconeogenesis and ketone body formation?

Hormone-sensitive Lipase

50

How does oral administration of a drug differ from IV, sublingual, and rectal administration?

Oral administration subjects a drug to a large amount of first-pass metabolism. If the drug is metabolized extensively by the liver (high first pass metabolism), the amount that reaches the systemic circulation (and therefore the bioavailability) will be low. 

 

The amount of drug exposed to the liver within the portal blood flow is the major determinant of hepatic or first-pass metabolism.

51

What is the course of the median nerve?

Courses between the humeral and ulnar heads of the pronator teres muscle and then runs between the flexor digitorum superficialis and the flexor digitorum profundus muscles before crossing the wrist within the carpal tunnel.

52

What prevents posterior displacement of the tibia relative to the femur?

PCL

 

*posterior drawer test*

53

Nausea, fever, fatigue, high temperature, weak and icteric. One week after a surgery in Mexico. What is the cause? What will the liver look like?

Drug-induced liver injury from inhaled anesthetic (halothane)

Halogenated anesthetics cause hepatocellular pattern of liver injury. This can range from milk asymptomatic aminotransferase elevation to fulminant hepatitis. Severe cases can cause rapid atrophy and a shrunken liver on autopsy.

54

What vitamin deficiency will cause: increased susceptibility of the neuronal and erythrocyte membranes to oxidative stress. Ataxia, impaired proprioception and vibratory sensation, and hemolytic anemia.

Vitamin E

55

What lung changes are associated with age?

Steady decrease in chest wall compliance

Steady increase in lung compliance (loss of elastic recoil)

Increased residual volume

Decreased FVC

Unchanged TLC

56

Estrogens are synthesized by the aromatization of androgens by aromatase. What drugs inhibit this action and what is the effect?

Aromatase Inhibitors (anastrozole, letrozole, exemestane)

Decrases synthesis of estrogen from androgens

Suppress estrogen levels

Slow progression of ER-positive tumors

57

Persistent lymphadema (like in a patient who has had a radical mastectomy) predisposes to the development of what pathology?

Lymphangiosarcoma

Rare malignant neoplasm of the endothelial lining of lymphatic channels

58

Differential clubbing and cyanosis without blood pressure or pulse discrepancy are pathognomonic for what?

Large PDA complicated by Eisenmenger Syndrome (reversal of shunt flow from L-R to R-L)

59

Catabolism of what leads to the formation of propionic acid, which is then converted to methylmalonic acid by biotin-dependent carboxylation?

Isoleucine

Valine

Threonine

Methionine

Cholesterol

Odd-chain FAs

60

What is the MOA of Timolol and other nonselective beta blockers in a pt. with open-angle glaucoma? What other drugs act the same way?

Diminish the secretion of aqueous humor by the ciliary epithelium

Acetazolamide (Carbonic anhydrase inhibitor)

apha 2 -AR agonists

61

What drugs decrease intraocular pressure by increasing the outflow of aqueous humor?

Prostaglandin F2alpha (latanoprost, travoprost)

Cholinomimetics (pilocarpine, carbachol)

62

79 y/o man with visual abnormalities, nausea, and anorexia. History of A-fib for which he takes an age adjusted dose of digoxin. Age related changes in which of the following factors accounts for the symptoms?

Renal clearance

Digoxin is predominantly cleared by the kidneys. Elderly patients need a lower dose of digoxin in order to prevent toxicity.

63

Pulmonary vascular resistance is lowest at what capacity?

Functional residual capacity

 

64

Red blood cell fragments, burr cells, and helmet cells are consistent with what?

Traumatic hemolysis

From either microangiopathic hemolytic anemia, or mechanical damage (like a prosthetic valve)

65

Vitamin B12 deficiency has what effect on parietal cell mass, gastrin, and intrinsic factor?

Decreased parietal cell mass

Decreased intrinsic factor production

Decreased gastric acid secretion --> increased gastrin release by antral G cells

66

What type of pneumoconioses presents as: dyspnea on exertion, productive cough, calcification of the rim of hilar nodes (eggshell calcification), birefringent silica particles surrounded by fibrous tissue

Silicosis

67

What are the findings of a person with CF on autopsy?

Bronchiectasis

Distal intestinal obstruction

Pancreatic duct obstruction and distention

Absent Vas Deferens

Thick, dehydrated, and viscous mucus within organs

68

What are the potential treatments used for bacterial vaginosis?

Clindamycin or Metronidazole

69

Woman who had a vaginal delivery 9 weeks ago. Hemoptysis. Ongoing vaginal bleeding since the delivery. Uterus is enlarged and the adnexa are normal. Increased beta-HCG. Multiple bilateral lung nodules. (she is not pregnant)

Gestational choriocarcinoma

Malignant tumor that arises from the trophoblast (cytotrophoblasts and syncytiotrophoblasts)

Often presents as dyspnea/hemoptysis due to pulmonary metastasis from hematogenous spread.