2015.04.14

Question 1

Administration of human chorionic gonadotropin (hCG)

Answer 1

Stimulates LH surge which causes ovulation.

Menotropin (human menopausal gonadotrophin) acts like FSH and leads to formation of a dominant ovarian follicle.

Question 2

Potter Syndrome

Answer 2

Marked by pulmonary hypoplasia, limb deformities, and characteristic facies (suborbital creases, depressed nasal tip, low-set ears, and retrognathia) as a result of oligohydraminos.

Classically occurs in fetuses with bilateral renal agenesis, where lack of fetal urine causes oligohydraminos. (Amniotic fluid is required for proper lung development).

Question 3

Lesch-Nyhan Syndrome

Answer 3

X-linked recessive disorder caused by a defect in hypoxanthine-guanine phosphoribosyltransferase (HGPRT). Elevated uric acid levels. Developmental delays and hypotonia.

This results in failure of the purine salvage pathway. Because they are not recycled, increased amounts of purine bases hypoxanthine and guanine are degraded to uric acid.

De novo purine synthesis must increase to replace the lost bases. (PRPP to form phosphoribosylamine in first committed step of de novo synthesis by Phosphoribosyl phosphate amidotransferase)

Question 4

Pre-eclampsia

Answer 4

Triad of hypertension, proteinuria and edema in pregnancy.

May progress to HELLP syndrome (Hemolytic anemia, elevated liver enzymes, and low platelets)

Question 5

Factor V Leiden

Answer 5

Modifed to resist activated protein C.

Resulting hypercoaguable state predisposes to DVTs, which are the source of most pulmonary emboli.

Question 6

Glucose 6-phosphate dehydrogenase deficiency

Answer 6

Defect in the HMP shunt that impairs glutathione reduction due to failure to produce NADPH.

Glutathione reductase deficiency causes a similar clinical picture and is pathophysiologically similar to G6PD.

Question 7

Testicular Hydrocele

Answer 7

Serous fluid accumulates within the tunica vaginallis

Tunica vaginalis is embryologically derived from the peritoneum; when it remains in communication with the peritoneum (patent processus vaginalis), a communicating hydrocele results.

Question 8

Tunica albuginea

Answer 8

Fibrous tissue that overlies the corpus spongiosum and corpora cavernosa of the penis

Question 9

Spermatic fascia layers are derived from what?

Answer 9

External spermatic fascia - aponeurosis of external oblique abdominal muscle.

Cremasteric - from internal oblique abdominal muscle and aponeurosis

Internal - from transversalis fascia. Immediately overlies the spermatic cord and tunica vaginalis

Question 10

Psoriasis

Answer 10

Chronic inflammatory skin disorder characterized by sharply demarcated, salmon-colored, rounded plaques covered with a loosely adherent, silvery-white scale.

Cytokines lead to keratinocyte proliferation, inflammation, and angiogenesis.

Treatment: topical vitamin D analogs (calcipotriene, calcitriol, tacalcitol) which bind to vitamin D receptor (nuclear TF) and causes inhibition of keratinocyte proliferation/differentiation. Cyclosporine, Etanercept, Methotrexate, Ustekinumab

Question 11

Cyclosporine

Answer 11

Inhibits NFAT (nuclear factor of activated T cells) from entering the nucleus and modulating transcription activity, impairing the production and release of IL-2 (and inhibiting IL-2 activation of resting T-lymphocytes)

Question 12

Etanercept

Answer 12

Recombinat form of human TNF receptor that binds to TNF-a.

Question 13

Methotrexate

Answer 13

Folate antimetabolite that reversibly binds to dihydrofolate reductase, resulting in inhibition of purine and thymidylic acid synthesis.

In psoriasis, thought to target rapidly proliferating epithelial cells in the skin.

Question 14

Ustekinumab

Answer 14

Huamn monoclonal antibody that targets IL-12 and IL-23. Inhibits differentiation and activation of CD4 Th1 and Th17 cells.

Question 15

Lambert-Eaton Myasthenic Syndrome

Answer 15

Disorder of NMJ manifesting with proximal muscle weakness (difficulty rising from chair, climbing stairs), cranial nerve involvement, autonomic symptoms (dry mouth or impotence).

Antibodies directed against voltage-gated calcium channels that participate in acetylcholine release.

50% patients have a malignancy (usually small cell lung cancer).

Differentiate from myasthenia gravis: hyporeflexia/areflexia, autonomic symptoms and classic incremental response to reptietive stimulation

Question 16

Myasthenia Gravis

Answer 16

Autoantibodies against postsynaptic nicotinic acetylcholine receptors.

Leads to decreased numbers of functional acetylcholine receptors at the NMJ, which reduces the end-plate potential following acetylcholine release. Because threshold potential is not reached, muscle cells do not depolarize.

Improvement with cholinesterase inhibitors and with rest.

Question 17

Treatment of Myasthenia Gravis

Answer 17

Cholinesterase inhibitor (pyridostigmine, etc) which causes excessive cholinergic stimulation (of gut, causing nausea, cramping, sweating, diarrhea)

Scopolamine is a selective muscarinic ACh receptor antagonist that will reduce the effects of cholinesterase inhibitors in sites where ACh action is mediated by muscarinic receptors. (Won’t affect nicotinic receptors - skeletal muscle). Hyoscyamine works as well.

Question 18

Fever, vesiculoulcerative gingivostomatitis, and cervical lymphadenopathy

Answer 18

common clinical manifestations of primary infection with herpes simplex virus (HSV-1).

Reactivation of a latent HSV infection in the trigeminal ganglia generally results in more limited perioral blisters or “cold sores”

Question 19

CFTR transmembrane protein

Answer 19

In respiratory and gastric glands, imapired functioning of CFTR reduces luminal chloride secretion and increases sodium and net water absorption, resulting in dehydrated mucus and a more negative transpeithelial potential difference.

In sweat glands, abnormal CFTR function causes reduced luminal salt absorption, leading to production of hypertonic sweat and high chloride content.

Nasal transepithelial difference is more negative than normal due to chloride ions retained at mucosal surface

Question 20

Congenital Hypothyroidism

Answer 20

Presents soon after birth with hypotonia, poor feeding, jaundice, macroglossia, constipation, and umbilical hernia.

It should be diagnosed as early as possible to prevent the development of mental retardation.

Question 21

First dose hypertension

Answer 21

adverse effect when initiating ACE inhibitors

predisposing risk factors: hyponatremia, hypovolemia secondary to diuretics, low baseline blood pressure, high renin or aldosterone levels, renal impairment, and heart failure.

Question 22

High specificity antibody for Rheumatoid arthritis

Answer 22

Anti-cyclic citrullinated peptide antibodies

Question 23

Rheumatoid factors

Answer 23

autoantibodies targeting the Fc portion of human IgG

present in RA, SLE, mixed cryoglobulinemia, and other inflammatory conditions

Question 24

Acyclovir nephrotoxicity

Answer 24

excreted principally in the urine via glomerular filtration and tubular secretion.

when the acyclovir concentration in the collecting duct exceeds its solubility, crystallization, crystalluria, and renal tubular damage may result.

treatment: hydration

Question 25

Etoposide

Answer 25

targets topoisomerase II (which induces transiet breaks in both DNA strands to relieve + and - supercoiling)

inhibits topoisomerase II’s ability to seal the strand breaks it induces, causing chromosomal breaks to accumulate and eventual cell death.

Used in testicular cancer and small cell lung cancer.

Question 26

Glucocorticoids and hyperglycemia

Answer 26

predominantly catabolic - causing muscle weakness, skin thinning, impaired wound-healing, osteoporosis, and immunosuppresion.

However, they increase liver protein synthesis, specifically enzymes involved in gluconeogenesis and glycogenesis.

Peripheral antagonism of insulin effects leads to development of hyperglycemia

Question 27

Suspensory ligament of the ovary

Answer 27

Nerves, arteries, veins, and lymphatics supplying the ovary are all delivered by this ligament.

Question 28

Round ligament of the uterus

Answer 28

courses through the inguinal canal and links the horns of the uterus to the external genitalia

Question 29

Signet ring carcinomas

Answer 29

1 of 2 major types of gastric adenocarcinoma

Diffuse involvement of the stomach wall.

They have a plaque-like appearance and are ill-defined.

Often they infiltrate large areas of the stomach wall and cause a “leather-bottle stomach” (linitis plastica)

Question 30

Intestinal-type adenocarcinomas of the stomach

Answer 30

closely resemble colon cancers

grow as nodular, polypoid, and well-demarcated masses

well-formed glands that consist of columnar or cuboidal cells are seen

Question 31

Microangiopathic hemolytic anemia, acute renal failure, thrombocytopenia

Answer 31

Hemolytic uremic syndrome

Widespread capillary thrombi consume platelets and cause mechanical damage to erythrocytes.

Resultant hemolytic anemia causes pallor, weakness and tachycardia.

Increased bleeding time since reduced number of platelets. Decreased RBC count and hematocrit. Increased bleeding time, LDH, BUN, creatinine.

Question 32

Restlessness and purposeless jerking movements months after a sore throat

Answer 32

Sydenham chorea

Manifestation of acute rheumatic fever

anti-streptococcal antibodies that cross-react with the basal ganglia.

Question 33

Varencicline

Answer 33

partial agonist of nicotinic acetylcholine receptor

reduces nicotine cravings and decreases pleasurable effects of reward pathways

Question 34

Thromboangiitis obliterans

Answer 34

seen in heavy cigarette smokers before age 35.

hypersensitivity to intradermal injections of tobacco extracts

segmental thrombosing vasculitis often extends into contiguous veins and nerves, encasing them in fibrous tissue

Question 35

Transmural inflammation of arterial wall with fibrinoid necrosis

Answer 35

polyarteritis nodosa