2015.04.12 (2)

Question 1

Mucicarmine stain

Answer 1

Detects polysaccharide capsule of Cryptococcus neoformans.

Red-stained capsule is a major virulence factor.

Question 2

Cryptococcus neoformans

Answer 2

Polysaccharide capsule that stains with mucicarmine.

Seen in tissue as round yeast cells with narrow-based buds.

Affects immunocompromised patients and is transmitted via respiratory route. May cause pulmonary disease.

Methenamine silver (GMS) and India ink staining is used too.

Subacute or chronic meningoencephalitis is most common presentation.

Question 3

Round yeast with broad-based budding and a thick, doubly-reflective wall

Answer 3

Blastomyces dermatitidis

causes lung disease and disseminated mycosis

Question 4

Histoplasma capsulatum

Answer 4

dimorphic fungus that causes tb-like pulmonary disease. causes disseminated mycosis in immunocompromised.

Found intracellulary in tissue (within macrophages) as small, ovoid, budding yeast cells

Question 5

Coccioides immitis

Answer 5

causes lung disease in immunocompetent people and disseminated mycosis in immunocompromised individuals.

large, irregulary sized, thick-walled spherules that contain small, round endospores.

Question 6

Enteropeptidase/Enterokinase

Answer 6

enzyme produced in the duodenum required for activation of trypsinogen into trypsin.

Enteropeptidase deficiency causes diarrhea, growth retardation and hypoproteinemia

Question 7

Pulsatile GnRH agonists adminstration

Answer 7

Stimulates FSH and LH for treatment of infertility.

Question 8

Constant (nonpulsatile) GnRH adminstration

Answer 8

Causeds down-regulation of GnRH receptors, which suppresses LH and FSH secretion.

Usually syntheteic analogue (leuprolide) is used.

Used for treatment of precocious puberty, prostate cancer, endometriosis, dysfunctional uterine bleeding (where suppression of HPA ovarian axis is indicated)

Question 9

Pleural effusion vs. Atelectasis

Answer 9

Opacified lung with lung volume loss (atelectasis) causes trachea deviation towards the opacified lung.

Trachea deviation away from opacified lung occurs with pleural effusion.

Question 10

Severe allergic asthma

Answer 10

Frequent exacerbations requiring oral steroids. Patients are initially treated with inhaled steroids and long-acting beta-agonists. However, symptom control is difficult because these patients are frequently resistant and need oral steroids.

Anti-IgE antibodies given as subcutaneous injection have been shown to be effective in patients with moderate-to-severe allergic asthma.

Omalizumab (recombinant humanized IgG1 monoclonal antibody that binds with IgE to inhibit IgE activity) is effective in reducing dependency on both oral and inhaled steroids.

Question 11

Visceral Obesity

Answer 11

Visceral fat is fat surround internal organs and has a much stronger correlation with insulin resistance than subcutaneous fat.

Measuring waist-to-hip ratio indirectly measures the viseral fat.

Question 12

Pulmonary abscesses

Answer 12

local suppurative collections within lung parenchyma that result in necrosis of the surrounding lung tissue.

destruction due to release of lysosomal enzymes from neutrophils and macrophages (initially to digest offending pathogens and debris, but can damage surrounding parenchyma, setting the stage for abscess formation)

Question 13

Major basic protein

Answer 13

contained in eosinophils

cationic protein that causes significant damage to parasites.

occasionally causes lysis of epithelial cells, resulting in host tissue damage.

Question 14

IFN-r production by CD4+ lymphocytes

Answer 14

responsible for phagolysosome formation, inducible nitric oxide synthase release, and development of granulomas and caseous necrosis

Question 15

Anticipation

Answer 15

Tendency for clinical symptoms to worsen and/or occur earlier in subsequent generations.

Common in disorders associated with trinucleotide repeats - Fragile X syndrome, myotonic dystrophy, and Friedrich ataxia.

Question 16

Pleiotropy

Answer 16

Mutation of one gene leads to multiple phenotypic abnormalities

Question 17

Genomic imprinting

Answer 17

selective inactivation of genes of either maternal or paternal origin, causing a phenomenon called “parent-of-origin gene expression”

Parder-Willi - deletion from the father; children show insatiable hunger and thirst and emotional lability

Angelman - deletions inherited from mother; “happy puppet” syndrome since children show jerky movements and happy predisposition.

Question 18

Treatment of diabetic ketoacidosis

Answer 18

IV hydration with normal saline and insulin.

This leads to decrease in serum glucose, osmolality, and potassium, as well as increases in serum bicarbonate and sodium.

Question 19

What causes increased insulin resistance in overweight individuals?

Answer 19

Free fatty acids and serum triglycerides

Question 20

Beta-hydroxybutyrate

Answer 20

Marker of insulin deficiency

Present in type I diabetes mellitus.

Question 21

Primary hyperparathyroidism

Answer 21

Parathyroid adenoma that causes “bones, stones, abdominal groans, and psychic moans”. Hypercalcemia:

1. PTH mediated increase in renal tubular Ca reabsorption
2. Increased production of calcitrol in kidneys causing increased GI Ca absorption
3. PTH-mediated increase in bone resorption

Involves cortical (compact) bone in appendicular skeleton. Subperiosteal erosions in phalanges of hand, granular “salt and pepper” skull, and osteolytic cysts in long bones (Osteitis fibrosa cystica).

Question 22

Osteoporosis

Answer 22

Trabecular thinning with fewere interconnections.

Question 23

Osteopetrosis

Answer 23

“marble bone disease”

decreased osteoclastic bone resoprtion, which results in accumulation of woven bone and diffuse skeletal thickening

Persistence of primary spongiosa in the medullary cavity with no mature trabeculae

Question 24

Hartnup Disease

Answer 24

Can result in niacin deficiency due to excess loss of dietary tryptophan, resulting from defective intestinal and renal tubular absorption of that amino acid.

Niacin (B3) is synthesized from tryptophan and tryptophan is an essential amino acid.

Aminoacidura (containing neutral amino acids, not proline, hydroxyproline and arginine - differentiates from Fanconi syndrome)

Question 25

Tetanospasmin

Answer 25

travel by retrograde axonal transport into the CNS. binds ganglioside receptors on neuronal membranes and the light chain inhibits release of glycine and GABA from inhibitory interneurons.

leads to sustained muscle contraction:

masseter muscle spasm (lockjaw), opisthotonos, dysphagia, facial muscle spasm (Risus sardonicus)

Question 26

Rinne test

Answer 26

Compares sound heard from mastoid bone to the external auditory meatus. (Air-conducted sound usually louder and longer than bone-conducted sound).

+ (normal): if sound is heard best at external auditory meatus.

Sensorineural hearing loss would be normal.

- (abnormal): if vibration heard better at mastoid

Suggests conductive hearing loss.

Question 27

Weber test

Answer 27

Differentiates between conductive and sensorineural hearing loss and localizes affected ear.

Vibration is normally heard equally in both ears.

Conductive hearing loss causes lateralization to the affected ear, as the conduction deficit masks ambient noise.

Sensorineural hearing loss causes lateralization to the unaffected ear, as the unimpaired inner ear can better sense the vibration.

Question 28

Adverse effects of protease inhibitors

Answer 28

Lipodystrophy - deposition of fat on back and abdomen and decreased adipose on the extremities, leading to “buffalo hump” appearance with central obesity and peripheral wasting.

Hyperglycemia

Inhibition of P450 (Should not use with Rifampin which increases activity of P450 and decreases serum protease inhibitors - Rifabutin should be used instead)

Question 29

TMP-SMX Side effects

Answer 29

Megaloblastic anemia, Steven-Johnson syndrome and toxic epidermal necrolysis

Question 30

Lipoic acid

Answer 30

Coenzyme for:

alpha-ketoglutarate dehydrogenase + branched-chain ketoacid dehydrogenase (deficiency results in maple syrup urine disease)

pyruvate dehydrogenase (deficiency results in lactic acidosis)

Question 31

Pyruvate kinase deficiency

Answer 31

causes hemolytic anemia due to failure of glycolysis and resultant failure to generate sufficient ATP to maintain erythrocyte structure.

Splenic hypertrophy results from increased work of the splenic parenchyma, which must removed these deformed erythrocytes from the circulation.

Question 32

Accumulation of sphingomyelin resulting in splenomegaly

Answer 32

Niemann-Pick disease

Question 33

Accumulation of glucocerebrosides responsible for splenomegaly

Answer 33

Gaucher disease

Question 34

Vinca alkaloid (Vincristine or Vinblastine)

Answer 34

Function by inhibiting microtubule formation.

Causes cell cycle-specific cytotoxicity during hte M phase of the cell cycle as the replicated chromosomes are unable to align and segregate.

Vincristine - neurotoxicity, peripheral neuropathy (because impaired transporting organelles from neuronal cell body to axon terminals)

Question 35

Nifedipine

Answer 35

Causes peripheral vasodilation which may result in reflex tachycardia.

This antihypertensive drug is useful for patients with bradycardia.

Question 36

Tardive dyskinesia

Answer 36

Involuntary perioral movements, such as biting, chewing, grimacing, and tongue protrusions

involuntary choreoathetoid movements of the head, limbs, and trunk may also be observed.

Develops 4 months - 4 years after treatment with antipsychotics. May be irreversible.

Question 37

Atypical antipsychotics and extrapyramidal symptoms

Answer 37

Risperidone - most likely to cause EPS

Clozapine - least likely to cause EPS. but is associated with agranulocytosis, which is why it is a medication of last resort

Question 38

Acute dystonia

Answer 38

4 hours - 4 days after antipsychotic medication

Muscle spasms or stiffness, tongue protrusions or twisting, opisthotonus, and oculogyric crisis (sustained elevation of the eyes in an upward position)

Treatmetn: antihistamines or anticholinergics

Question 39

Arcarbose and Miglitol

Answer 39

Alpha-glucosidase inhibitors that decrease the activity of disaccharidases on the intestinal border.

Cause flatulence, GI bloating, abdominal pain, and rash.

Question 40

TNF-alpha

Answer 40

Produced by macrophages in response to infection, as well as by some neoplastic cells.

Can induce a wasting syndrom (cachexia - anorexia, malaise, anemia, weight loss).

Mediates paraneoplastic cachexia in humans by suppressing appetite, inhibiting lipoprotein lipase and increasing insulin resistance of peripheral tissues.

Question 41

Colchicine

Answer 41

Used for acute gouty arthritis and prophylaxis of recurrent gouty arthritis.

Inhibits leukocyte migration and phagocytosis by blocking tubulin polymerization.

Nause and diarrhea are common side effects.

Question 42

Metronidazole when combined with alcohol

Answer 42

Metronidazole can cause disulfiram-like effects when combined with alcohol (Disulfiram is an aldehyde dehydrogenase inhibitor that causes adverse effects after alcohol consumption).

Metronidazole is used to treat giardiasis, trichomonas vaginitis, and bacterial vaginosis

Question 43

Treatment of Candida vaginitis

Answer 43

Fluconazole

Question 44

Microglia

Answer 44

Move to area of ischemic infarct approximately 3-5 days after the onset of ischemia and phagocytize the fragments of neurons, myelin, and necrotic debris.

Cystic space replaces the necrosis and astrocytes form a glial scar along the periphery.

Question 45

Adenomyosis

Answer 45

Presence of endometrial glandular tissue within the myometrium.

Causes menorrhagia and dysmenorrhea

PE reveals uniformly enlarged uterus (due to uterine SM hypertrophy and hyperplasia)

Question 46

Leiomyoma

Answer 46

Common benign pseudoencapsulated tumor of monoclonal uterine smooth muscle cells.

PE reveals irregularly enlarged uterus or uterine mass.

Question 47

Endometrial adenocarcinoma

Answer 47

most common type of endometrial carcinoma

Glandular structures with malignant-appearing cells (nuclear atypia, increased mitotic activity) invade the uterine wall by direct extension.

Most common presentation: abnormal uterine bleeding in a postmenopausal woman.

Question 48

Endometriosis

Answer 48

Presence of normal endometrial tissue in abnormal locations (outside the uterus)

These ectopic foci of endometrial tissue undergo menstrual-type bleeding causing cyclic pelvic pain (dysmenorrhea) due to local inflammation and fibrosis

Question 49

Peptic ulcers with least risk of malignancy

Answer 49

Duodenal ulcers

Question 50

Syringomyelia

Answer 50

Disproportionate loss of pain and temperature sensation (dissociated anesthesia) involving the arms and hands.

Formation of a cavity (syrinx) in the cervical region of the spinal cord.

The syrinx damages the ventral white commissure, leading to bilateral loss of pain and temperature sensation that is limited to the affected levels (typically arms and hands); distal sensation is preserved.

Destruction of motor neurons in the ventral horns causes flaccid paralysis and atrophy of the intrinsic muscles of the hand.

Question 51

Non-selective beta-blockers and hypoglycemia

Answer 51

During hypoglycemia: adrenergic symptoms (sweating, tremor, palpitations) are early signs. CNS symptoms develop later.

Non-selective b-blockers can inhibit epinephrine and norepinephrine-mediated compensatory reactions to hypoglycemia. Mask its adrenergic symptoms.

Blockade of b2 receptors inhibits hepatic gluconeogenesis and peripheral glycogenolysis and lipolysis and exacerbate hypoglycemia.

Selective b1 antagonists should be used instead if a b-blocker is necessary

Question 52

Superior Vena Cava

Answer 52

Intrathoracic spread of bronchogenic carcinoma or non-Hodgkin lymphoma may lead to compression of the superior vena cava, causing impaired venous return from the upper part of the body.

Signs and symptoms include dyspnea, facial swelling, and dilated collateral veins in the upper trunk.