UWSA #2

Question 1

Rheumatic fever is most commonly associated with what murmur and what does it sound like?

Answer 1

• Mitral stenosis
• Diastolic thrill palpable over the cardiac apex and a low-pitched, rumbling, mid-diastolic murmur heard best over the apex
• Best heard with patient in left lateral decubitus position

Question 2

Peutz-Jeghers syndrome is an autosomal dominant condition caused by mutations in which gene and on what chromosome?

Answer 2

Serine/threonine kinase 11 (STK 11) on Cr. 19

Question 3

Which type of benign tumor is characterized by broad fascicles of rounded fibroblasts with abundant cytoplasm and a significant surrounding collagenous matrix infiltrating adjacent soft tissue?

Answer 3

Desmoid Tumor

Question 4

What will immunofluorescence show in Pemphigus Vulgaris vs. Bullous Pemphigoid?

Answer 4

• P.V. = IgG and C3 in a netlike or “chicken wire” pattern btw keratinocytes since this disease affects desmosomes
• B.P. = IgG along the basemement membrane since this disease affects hemidesmosomes

Question 5

Alcoholic cerebellar degeneration is due to loss of Purkinje cells and is most prominently seen in which part?

Answer 5

Cerebellar Vermis

Question 6

What is a common cause of brisk painless bleeding in child with Meckel Diverticulum?

Answer 6

Heterotropic gastric tissue (often Pancreatic) which can ulcerate and cause bleeding

Question 7

CD40 ligand deficiency is also known as what?

Answer 7

Hyper-IgM Syndrome

Question 8

Which prokaryotic enzyme with 5’ to 3’ exonuclease activity serves to remove RNA primers on the lagging strand and replace them with new DNA?

Answer 8

DNA polymerase I

Question 9

Lynch Syndrome is an AD disorder caused by mutations in mismatch repair genes and is associated with what neoplasms?

Answer 9

• Colorectal cancer
• Endometrial cancer
• Ovarian cancer

Question 10

In PCR, DNA polymerase adds new nucleotides in which direction on the elongating strand?

Answer 10

5’ to 3’ direction (letters B and C) in the image

Question 11

What EKG findings will be seen with hypocalcemia vs. hypercalcemia?

Answer 11

• Hypocalcemia: causes QT prolongation
• Hypercalcemia: causes QT interval shortening and in severe causes T-wave flattening or inversion

Question 12

Pinealomas may damage which region of the brainstem and cause what?

Answer 12

• Dorsal midbrain in the superior colliculus region
• Parinaud syndrome: upward gaze palsy + absent pupillary light reflex + impaired convergence

Question 13

Which proliferating cells are the primary cell population within the nodules of a cirrhotic liver?

Answer 13

Hepatocytes

Question 14

Which cell of the liver can differentiate into a myofibroblast upon injury to the liver and plays a large role in the production of fibrosis in cirrhosis?

Answer 14

Stellate (ito) cells

Question 15

What is the only type of shock that has increased mixed venous oxygen saturation (MvO₂) and decreased systemic vascular resistance (SVR)?

Answer 15

Septic Shock

Question 16

What is the reason that some women can display disease manifestations of X-linked disorders (typically only seen in men)?

Answer 16

• Skewed X inactivation
• One X chromosome is normally inactivated in each somatic cell and the selection of the inactivated X chromosome is random

Question 17

What will electron microscopy of Membranous Nephropathy show?

Answer 17

Dense, subepithelial deposits that have a “spike and dome” appearance

Question 18

What’s the venous drainage of the rectum below and above the dentate line?

Answer 18

• Above: superior rectal v. —> inferior mesenteric v. —> portal system
• Below: middle and inferior rectal v. –> internal iliac v. –> systemic circulation

Question 19

What is the effect of insulin on the bifunctional PFK-2/F-2,6-BPase enzyme complex?

Answer 19

• Activates the PFK-2 domain, converting F-6-P –> F-2,6-BP
• F-2,6-BP activates PFK-1 which drives the cell toward glycolysis

Question 20

What is the MOA of Danazol?

Answer 20

An androgen used to suppress FSH and LH release by the pituitary gland

Question 21

What is the MOA of flutamide?

Answer 21

Anti-androgen that inhibits androgen uptake or the binding of androgen in tissues

Question 22

What is the standard tx for Chlamydia trachomatis (nongonococcal) urethritis?

Answer 22

• Azithromycin (bacterial protein synthesis inhibitor; bind 23s rRNA of 50S ribosomal subunit and inhibit translocation
• Complicated infections (i.e, epididymitis) are tx with a 2-week course of doxycycline or a week-long courseofazithromycin

Question 23

What are the clinical findings of CYP17A1 deficiency?

Answer 23

• This is 17-hydroxylase deficiency
• Adolescent girl with persistent HTN and hypokalemia due to excess mineralocorticoids + cortisol deficiency

Question 24

The ATM gene defective in Ataxia-telangiectasia is important for what?

Answer 24

DNA repair following ionizing radiation

Question 25

What is considered a positive and negative test with an agglutination inhibition test for pregnancy?

Answer 25

- In the **absence** of agglutination the test is considered **positive** - In the **presence** of agglutination the test is considered **negative**

Question 26

When a stent is placed in a coronary artery what is the purpose of coating it with everolimus, sirolimus, or zotarolimus?

Answer 26

- Cytostatic drugs that **inhibit mTOR**, blocking the cell cycle btw **G1** and **S** phase - This _reduces_ **smooth muscle cell proliferation**; preventing **neointimal hyperplasia** and **stent restensosis**

Question 27

What is the inheritance pattern of ornithine transcarbamylase (OTC) deficiency?

Answer 27

**X-linked** (all other urea cycle disorders are **AR**)

Question 28

Which step in collagen synthesis requires Vitamin C?

Answer 28

- **Hydroxylation** of the **proline** and **lysine** residues by **prolyl hydroxylase** and **lysyl hydroxylase** - Essential for **proper** assembly of **pro-alpha** chains into **triple helical procollagen** \*All occuring in the **RER**\*

Question 29

What is the inheritance of MCAD deficiency?

Answer 29

**Autosomal Recessive**

Question 30

What are 3 major disease manifestatons of Von Hippel-Lindau disease?

Answer 30

- **Cerebellar** and **retinal hemangioblastomas** - **Pheochromocytoma** - **Renal cell carcinoma** (clear cell type)

Question 31

Which type of mutation wont change the number of amino acids in a protein but can result in loss of function of an enzyme?

Answer 31

**Point mutations** --\> **Missense** (seen in **MCAD** **deficiency** and **beta-thalassemia**)

Question 32

Which susceptibility locus is associated with dysplastic nevus syndrome and on what chromosome; what's its normal function?

Answer 32

- **CDKN2A** on chromosome **9p21** - Encodes **p16** which negatively regulates **CDK4** a regulator of the **G1 --\> S checkpoint**

Question 33

Which 2 major drug classes potentiate GABA channel-mediated increases in chloride conductance?

Answer 33

**Benzodiazepines** and **Barbiturates**

Question 34

What does the embryonic diencephalon give rise to?

Answer 34

**Thalamus** and **3rd ventricle**

Question 35

What type of protein is characterized by abundant **arginine** and **lysine** residues containing a 30-amino-acid alpha-helical segment that consists of _repeated_ **leucine** residues at every 7th position?

Answer 35

**Leucine Zipper** class of eukaryotic **transcription factors**

Question 36

Where does de novo synthesis of purines and pyrimidines start within the cell and then where does it end up?

Answer 36

- Begins in the **cytosol** - Synthesized **purines/pyrimidines** nucleotides are then used for DNA synthesis in the **nucleus**

Question 37

What is contained within the aortic hiatus and the esophageal hiatus?

Answer 37

- **Aortic**: contains the **aorta + thoracic duct** + **azygos vein** - **Esophageal**: contains the **esophagus** + **vagus** **trunks**