5/14 Mixed

Question 1

Why does an infection with N. gonorrhoeae not result in lasting immunity

Answer 1

Ability of bacteria to modify their outer membrane proteins by the process of antigenic variation. Antibodies generated during one infection will only be specific for that single antigenic epitope.

*Remember repeated Neisseria infections can be caused by terminal complement deficiencies leading to an inability to form MAC complex

Question 2

Phenylketonuria

Answer 2

Most cases due to phenylalanine hydroxylase deficiency
Less commonly due to BH4 (tetrahydrobiopterin) deficiency secondary to dihydropteridine reductase deficiency
Leads to phenylalanine accumulation and low levels of serotonin and other neurotransmitters > leads to neurologic deterioration

Question 3

Infraspinatus

Answer 3

External rotation of the shoulder

Rotator cuff muscles (supraspinatus, infraspinatus, teres minor, subscapularis)

Question 4

Hydroxyurea in the treatment of sickle cell dx

Answer 4

Increases fetal hemoglobin

Reserved for patients with frequent pain crises

Question 5

Nucleosome structure

Answer 5

Composed of DNA wrapped around a core of 8 histone proteins (2 molecules each of H2A, H2B, H3, and H4).
H1 histone is located outside of the histone core and helps package nucleosomes into more compact structures by binding and linking the DNA between adjacent nucleosomes

Question 6

Transport of glucose into cells

Answer 6

Occurs by facilitated diffusion
Moves from areas of high concentration to areas of low concentration with the help of transmembrane glucose transporter proteins (GLUT)
These carrier proteins are steroselective and have preference for D-glucose

Question 7

ABG of pulmonary embolism

Answer 7

Hypoxemia, respiratory alkalosis (hypocapnia), bicarb is normal (acute phase)

Question 8

TCA antidepressant side effects

Answer 8

Strong anticholinergic properties
Confusion, constipation, urinary retention
Use with caution in the elderly!

Question 9

Most commonly affected tendon in rotator cuff syndrome

Answer 9

Supraspinatus tendon
“Empty can supraspinatus test”= abduction of the humerus in parallel to the axis of the scapula (30 d forward flexion) while in full internal rotation (thumbs pointed to the floor)

Question 10

Patent Ductus Arteriosus (PDA)

Answer 10

Embryonic derivative of the sixth aortic arch

Question 11

Biliary atresia

Answer 11

Progressive obstruction of extrahepatic bile ducts
Immune or viral induced
Infants present with jaundice within first 2 months of life, with dark urine and pale stools, firm hepatomegaly , elevated direct bilirubin
Biopsy: Intrahepatic bile duct proliferation, portal tract edema, and fibrosis

Question 12

Caspofungin (echinocandin antifungals)

Answer 12

Block glucan synthesis
Suppress fungal cell wall synthesis
Most active against Candida and Aspergillus

Question 13

What is the most common valve affected by infective endocarditis?

Answer 13

Mitral valve

Mitral valve prolapse is the most common underlying valvular disease predisposing to the development of IE

Question 14

Adenomyosis

Answer 14

Presence of endometrial glandular tissue within the myometrium
Heavy menstrual bleeding, dysmenorrhea, uniformly enlarged uterus
Normal appearing endometrial tissue on biopsy

Question 15

Thiazolidinediones (TZDs)

Answer 15

Decrease insulin resistance
Active peroxisome-proliferator activated receptor-y (nuclear receptor that alters the transcription of genes involved in glucose and lipid metabolism)

Question 16

Drug induced lupus erythematosus

Answer 16

New onset lupus symptoms
ANA antibodies and anti-histone Abs
Exposure to hydralazine, procainamide, isoniazid, minocycline, quinidine

Question 17

Alpha-1 anti-trypsin deficiency

Answer 17

Panacinar emphysema and liver disease

Question 18

Obturator nerve

Answer 18

Descends through obturator canal
Supplies thigh ADDUCTOR muscles
Nerve injury due to compression (pelvic trauma, surgery, tumor)
Weakness on thigh adduction and sensory loss over the distal medial thigh

Question 19

Right sided colon cancers

Answer 19

Present with features of iron deficiency anemia (fatigue, pallor) due to OCCULT blood loss
Exophytic masses

Question 20

Migratory thrombophlebitis should raise suspicion for

Answer 20

CANCER
Visceral adenocardinomas of pancreas, colon, lung
> hypercoaguability
Trousseau syndrome

Question 21

Common peroneal

Answer 21

Susceptible to injury at the lateral neck of the fibula caused by compression (prolonged lying during surgery, crossing the legs, leg casts)
Patients present with “foot drop”, weakness on foot dorsiflexion, eversion, toe extension
Sensory loss over the lateral leg and dorsolateral foot

Question 22

Rx of Heparin overdose

Answer 22

Protamine

Treats bleeding due to heparin toxicity

Question 23

Rx: spasticity-related complications caused by MS

Answer 23

Paraparesis, urge incontinence, thoracic sensory level

Baclogen (agonist of GABA-B), Tizanidine

Question 24

3rd part of the duodenum

Answer 24

Courses horizontally across the abdominal aorta and inferior vena cava at the level of the third lumbar vertebra
In close association with the uncinate process of the pancreas and the superior mesenteric artery/vein (superior mesenteric vessels lie anterior to the duodenum at this location)

Question 25

Ivabradine

Answer 25

Selectively inhibits the funny sodium channels (If), prolonging the slow depolarization phase (4) and slowing the SA node firing rate
Negative chronotropic effect with no effect on cardiac contractility (inotropy) or relaxation

Question 26

Caudal regression syndrome

Answer 26

Agenesis of sacrum and lumbar spine
Flaccid paralysis of legs, urinary incontinence
Related to poorly controlled maternal diabetes

Question 27

Medications with anticholinergic properties

Answer 27

Antihistamines
Tricyclic antidepressants
1st low potency anti-psychotics (chlorpromazine)
2 gen antipsychotic clozapine
Antiparkinsonian drugs (benztropine, trihexyphenidyl)
Belladonna alkaloids (atropine)

Question 28

The suspensory ligament of the ovary

Answer 28

Contains the ovarian artery, vein, lymphatics, and nerves

Ovarian artery is a major blood supply to the ovary and must be ligated during an oophorectomy to prevent heavy bleeding

Question 29

Oocyte arrest in meiosis over time

Answer 29

Primary oocytes are completely developed in female embryos by the fifth month of gestation, at which point they are arrested in prophase of meiosis I
Normal menstrual cycle hormones stimulate the primary oocyte to resume differentiation. Prior to fertilization, secondary oocytes are arrested in metaphase of meiosis II

Question 30

Suppurative parotitis

Answer 30

Risk factors: decreased salivary flow (anticholinergics, calculi, neoplasms, dehydration, intubation)
Micro: staph aureus, anaerobes
Presentation: firm, erythematous pre/postauricular swelling
Trismus, dysphagia, fever, chills
Elevated serum amylase without pancreatitis

Question 31

Protein A MOA of staph aureus

Answer 31

Forms part of the outer peptidoglycan layer of S. aureus
Binds with the Fc portion of IgG antibodies at the complement binding site to prevent complement activation
Impaired opsonization and phagocytosis

Question 32

Zenker Diverticulum

Answer 32

Caused by abnormal spasm or diminished relaxation of the cricopharyngeal muscles during swallowing (cricopharyngeal motor dysfunction)

Question 33

Methotrexate side effects

Answer 33

Toxicity to oral and GI mucosa (ulcerations), hair follicles (alopecia), and BM (pancytopenia), hepatotoxicity, pulmonary fibrosis, increased risk for opportunistic infections

Question 34

Parasitic killing by eosinophils

Answer 34

IgE and IgG on parasite trigger eosinophil degranulation and release of cytotoxic protein (major basic protein) and ROS
Antibody-dependent cell-mediated cytotoxicity

Question 35

SE of Clozapine

Answer 35

Aganulocytosis (>neutropenia)
Seizures
Myocarditis
Metabolic Syndrome

***Make sure to monitor: absolute neutrophil count

Question 36

Listeria Monocytogenese

Answer 36

Requires intact cell-mediated immunity

Question 37

Flecainide

Answer 37

Class Ic antiarrhythmic
Rx: supraventricular tachycardias (a. fib)
Bind fast Na channels, blocking inward Na current and prolonging QRS
Slowest to dissociate > use-dependence (Na blocking effects intensify as the heart rate increases due to less time between action potential for the medication to dissociate)

Question 38

Dissemination intravascular coagulation in obstetrics

Answer 38

Placental damage > release of tissue factor from placenta into maternal circulation > activation of intravacular coagulation > circulating microthrombi > organ ischemia, fibrinolysis (+ D-dimer), platelet consumption, coag factor consumption > bleeding

Question 39

Prostatectomy potential consequence

Answer 39

Injury to prostatic plexus (in the fascia surrounding the gland) can cause erectile dysfunction (innervates the corpora cavernosa of the the penis)

Question 40

Treatment of congenital adrenal hyperplasia

Answer 40

Administer low doses of exogenous corticosteroids to suppress ACTH (adrencorticotropic hormone) secretion. By removing excessive ACTH stimulation, exogenous corticosteroids can decrease androgen production by the adrenal cortex