Week 1

Question 1

What is the major component of surfactant? Function?

Answer 1

Dipalmitoyl phosphatidylcholine (lecithin)
Function is to decrease alveolar surface tension and prevent alveolar collapse

Question 2

What causes cilia to be immotile in Kartageners syndrome?

Answer 2

Dynein arm defect

Question 3

What is phosphatidylglycerol?

Answer 3

A compound measured in amniotic fluid to determine fetal lung maturity, used in conjunction with lecithin:sphingomyelin ratio

Question 4

Adrenergic symptoms (heart palpitations, sweating, headaches) and high urine metanephrine indicate what? What is the treatment? SE of treatment?

Answer 4

Pheochromocytoma - tumor that releases EPI, NE, DA
Treatment incudes alpha adrenergic receptor antagonists
DOC is phenoxybenzamine - irreversible, nonselective alpha blocker
Blocking alpha receptors can lead to HYPOTENSION because vasoconstriction is impaired

Question 5

Classic signs of increased intracranial pressure? Sign of uncal herniation? Treatment?

Answer 5

Coma, bradycardia, HTN, hyperventilation and papilladema
A single fixed and dilated pupil can be a sign of ipsilateral uncal herniation
The immediate treatment is intubation with hyperventilation, elevating the head of the bed to 30 degrees, and using osmotic diuretics such as mannitol

Question 6

Why does hyperventilation help with increased ICP?

Answer 6

CO2 is a powerful vasodilator of cerebral blood vessels. Mechanical hyperventilation can lower CO2 and rapidly reduce ICP through vasoconstriction and a decrease in the volume of intracranial blood

Question 7

What accounts for 40-50% of all inherited thrombophilias?

Answer 7

Factor V leiden mutation (increased risk of recurrent thrombotic events, including unusual locations like the mesenteric veins)

Question 8

Von Willebrands deficiency causes…What is it due to?

Answer 8

Prolonged bleeding time (nose bleeds, prolonged bleeding after trauma or surgery, hematoma). The most common inherited bleeding disorder in the US. Due to improper or absent formation of vW fx, a protein that binds platelets to the endothelium during clot formation. This protein also carries fx VIII, an important component of the clotting cascade

Question 9

Von Hippel-Lindau disease is characterized by,,,

Answer 9

abnormal blood vessel growth leading to angiomas and hemangioblastomas in the retina, brain, and spinal cord

Question 10

Propylthiouracil (PTU) is a standard agent in the treatment of hyperthyroidism. What is its mechanism of action? What are the adverse effects?

Answer 10

Inhibits both the conversion of iodide to elemental iodine and the organification of iodine with tyrosine, therefore blocking the production of mono- and diiodotyrosine within thyroid follicular cells (thyroid is formed by combining iodine and a protein called thyroglobulin with the assistance of an enzyme called peroxidase, PTU inhibits iodine and peroxidase). PTU also acts peripherally to inhibit the conversion of T4 to T3 (the more active form).
Adverse effects include exfoliative skin rash (most common) and agranulocytosis (most severe but rare)

Question 11

Scarlet fever is caused by…

Answer 11

S. pyogenes or group A strep. It is mediated by a pyrogenic exotoxin and causes fever and diffuse erythema/rash

Question 12

What is Whipple’s disease? What does biopsy show?

Answer 12

Whipple’s disease is caused by an infection with Tropheryma whipplei (gram+, non-acid-fast, PAS + bacillus). Symptoms include athralgias, weight loss, diarrhea and abdominal pain. Biopsy shows accumulation of macrophages with brightly stained PAS+ intracellular material

Question 13

What viruses are in the flaviviridae family?

Answer 13

Flavus = yellow. Primarily spread through arthropod vectors. Linear SS (+) RNA family with icosahedral capsids.

Yellow fever, West nile virus, Dengue fever, Hepatitis C, Japanese encephalitis

Question 14

Vaginal bleeding in postmenopausal woman (55-65) should raise the concern for what? What is it associated with?

Answer 14

Endometrial cancer
Associated with the action of unopposed estrogen on the uterus such as nulliparity, obesity, early menarche, late menopause and exogenous estrogen use
*with hormonal replacement therapy, progesterone is administered along with estrogen to mitigate this effect

Question 15

What is Tamoxifen? What is it used for? Risks?

Answer 15

Tamoxifen is a partial agonist at the estrogen receptor. It blocks estrogen from binding at receptors in the breast making it a useful therapy for breast cancer BUT activates receptors in the endometrium leading to endometrial hyperplasia and an increased risk of endometrial cancer. Would see painless vaginal bleeding in a postmenopausal woman.
Other adverse effects: increased bone density, hypercoagulability, hot flashes, night sweats and vaginal discharge

Question 16

What are leiomyomas? What age group do they affect?

Answer 16

Benign soft tissue neoplasm. Commonly called uterine fibroids, they can cause irregular bleeding. Most occur in woman <40 years old, with regression occurring after menopause. Many are asymptomatic but clinical symptoms can include severe pelvic pain and heavy or irregular menstrual bleeding. Risk factors include AA race, early menarche, nulliparity, and a positive family history

Question 17

Epigastric pain improving after eating is…

Answer 17

Duodenal ulcer (vs. pain increasing after meals with gastric ulcer)

Question 18

Treatment of H. Pylori? (Triple therapy)

Answer 18

Omeprazole (PPI), clarithromycin, and either amoxicillin or metronidazole

Question 19

Neurofibromatosis type 2 is inherited in what manner?

Caused by? What is type 2 associated with?

Answer 19

Autosomal dominant
Caused by a mutation in the NF2 gene on chromosome 22
Type 2 is associated with bilateral acoustic neuromas

Question 20

Smudge cells are associated with what?

Answer 20

Chronic lymphocytic leukemia

Question 21

Patients with CML have marked leukocytosis and a peripheral blood smear showing…

Answer 21

myeloid cells in various stage of development, from mature granulocytes to metamyelocytes to myelocytes

Question 22

What is multiple myeloma? Hallmark symptoms?

Answer 22

Multiple myeloma is a cancer of plasma cells in which abnormal plasma cells multiply uncontrollably in the bone marrow and occasionally in other parts of the body
Hallmark symptoms: renal insufficiency, anemia, lytic bone lesions, and susceptibility to infection

Question 23

Initial treatment for myasthenia gravis? What is used to test for MG?

Answer 23

Pyridostigmine (duration of 3-6 hours), an acetylcholinesterase inhibitor. Prolongs the effects of acetylcholine by competing for attachment to AChE. Thymectomy is first line treatment in patients with generalized myasthenia gravis
Edrophonium is a readily reversible AChE inhibitor used for dx. Duration of action is only 19 minutes and is thus impractical for treatment

Question 24

What triggers release of catecholamines (epinephrine and norepinephrine) from the adrenal medulla? AKA how do you produce a situation in the lab that resembles pheochromocytoma HTN crisis

Answer 24

Direct stimulation by pre-ganglionic sympathetic neurons via acetylcholine. The adrenal medulla is a unique sympathetic neurotransmitter in that the nerves that supply it do not first synapse in other sympathetic ganglia. Presynaptic neurons typically use ACh as their NT. In this case the ACh binds to nicotinic ACh receptors in the adrenal medulla

Question 25

Niemann-Pick disease typically presents with? What is the deficiency? What does the enzyme convert?

Answer 25

Hepatosplenomegaly and progressive widespread neurodegeneration
*cherry-red spot on the macula & foam cells (lipin-laden macrophages)
Deficiency of sphingomyelinase (converts sphingomyelin to cerebroside)

Question 26

Lysosomal storage diseases are inherited?

Answer 26

AR except for Fabry which is XR

Question 27

Which disease is deficient in Hexosaminidase A? What does this enzyme convert? How does the disease present?

Answer 27

Tay-Sachs
Converts ganglioside M2 to ganglioside M3
The disease presents with progressive neurodegeneration and developmental delay. Children become blind, deaf and unable to swallow.
*Cherry red spot on macular, TS distinguishable from Neiman-Pick by absence of hepatosplenomegaly

Question 28

Gauchers disease: enzyme, presentation, light microscopy appearance

Answer 28

Enzyme deficient is B-Glucocerebrosidase (converts glucocerebroside to cerebroside)
Clinical manifestation includes hepatosplenomegaly, skeletal weakness and bone crises (aseptic necrosis of femur)
Macrophages appear as crumpled up paper on light microscopy and are known as Gaucher’s cells

Question 29

Fabry disease: enzyme, build up and findings

Answer 29

Enzyme: a-galactosidase A (trihexoside to lactosyl cerebroside)
Accumulated substrate: ceramide trihexoside
Findings: Peripheral neuropathy of hands/feet, angiokeratomas (tiny painless papules), cardiovascular/renal disease

Question 30

Krabbe’s disease: enzyme, build up and findings

Answer 30

Enzyme: Galactocerebrosidase (galactocerebroside to cerebroside)
Accumulated substrate: Galactocerebroside, psychosine
Findings: Normal at birth, 3-6 months; Peripheral neuropathy, developmental delay, optic atrophy, globoid cells

Question 31

APL is associated with what translocation? What genes does this involve? Treatment?

Answer 31

t (15;17) - PML and retinoid acid receptor

Treatment with retinoic acid frequently leads to clinical remission

Question 32

C-myc and immunoglobulin heavy chain locus translocation occurs between what chromosomes? What is the resulting disease?

Answer 32

t(8;14)

Burkitt’s lymphoma

Question 33

Burkitt’s lymphoma - what is the translocation (genes and chromosome number)

Answer 33

t(8;14)
8 - c-myc
14 - immunoglobulin heavy chain locus

Question 34

What virus is associated with congenital deafness?

Answer 34

Rubella - a less severe viral exanthem that starts on the face and spreads to the trunk and extremities. Many infections are subclinical, but rubella can cause severe birth defects, including congenital deafness, when infection occurs during the prenatal period`

Question 35

Mumps causes…

Answer 35

Caused by an RNA paramyxovirus that replicates in the upper respiratory tract and causes parotiditis and frequently orchitis. Pancreatitis and meningitis may also be present

Question 36

Measles presentation? Rare complication?

Answer 36

Presents with a relatively nonspecific prodrome of cough, fever and runny nose. The rash develops 1-2 days after the appearance of Koplik’s spots (red oral lesions with blue-white centers). Spreads from head to toe over a 3-day period. Rarely, it can cause subacute sclerosing panencephalitis in which patients exhibit pyschoneurologic deterioration 10 or more years after infection with the measles virus. It is a progressive disorder that can manifest with seizures, myoclonus, ataxia, and personality changes and eventually results in death

Question 37

What is an extraintestinal manifestation of IBS that commonly presents on the lower legs? Treatment?

Answer 37

Skin lesions such as pyoderma gangrenosum (half of all cases are extra intestinal IBS manifestations). Extremely painful and on the legs. Is not correlated with flares of IBS.
Treatment is steroids (because the sore is not infected but rather due to his own immune system)

Question 38

Anorexia nervosa is associated with what?

Answer 38

Osteoporosis (decreased estrogen over time)/stress fractures, amenorrhea, lanugo (fine body hair), severe weight loss, anemia and electrolyte imbalances

Question 39

What is the most common inflammatory marker in polymyositis?

Answer 39

Lymphocytes

In polymyositis, an infiltrate of CD8+ T-lymphoctytes and macrophages surround and destroy healthy muscle fibers

Question 40

What is HBV infection treated with? Hep c?

Answer 40

Hep B - Lamivudine and interferon-a

Hep C - Ribavirin and pegylated interferon-a2

Question 41

People who are homozygous for mutations of what receptor are immune to certain strains of HIV?

Answer 41

Mutations of the CCR5 chemokine receptor on macrophages that facilities viral entry into cells
Almost never seen in those of asian or african descent

Question 42

List the four mechanoreceptors and what stimuli they are responsible for

Answer 42

Meissner corpuscles: light discriminatory touch
Pacinian corpuscles: Perception of pressure, coarse touch, vibration and tension. *Often damaged in diabetic neuropathy
Ruffinini end organ and Merkel’s disks: sustained pressure, deep static touch (shapes, edges)

Question 43

SIADH causes? Results?

Answer 43

Causes: ectopic ADH (small cell lung cancer), CNS disorders/head trauma, pulmonary disease, drugs (cyclophosphamide)
Results in excessive water retention, hyponatremia with continued urinary Na+, urine osmolarity>serum osmolarity

Question 44

Which way does the oxygen-hemogobin dissociation curve shift if there is reduced affinity of hemoglobin for oxygen? What does this mean? What can cause it?

Answer 44

LEFT
Reduction in affinity enables increased delivery of oxygen to peripheral tissues
Increased temperature, acidity, increased metabolic demands (exercise) and 2,3-DPG can all shift the curve left

Question 45

Hepatic adenoma may be caused by what?

Answer 45

Oral contraceptive use
Rare, benign liver tumor often related to oral contraceptive or anabolic steroid use; may regress spontaneously or rupture (abdominal pain and shock)