Day 2 Flashcards
Does a partial agonist always have a lower maximal efficacy than a full agonist? Does a partial agonist always have a lower potency than a full agonist? (FA15 p246) (FA16 p240) (SU p12-14)
Partial agonist – acts on same site as full agonist / BUT lower maximal effect (decreased efficacy) Potency is an independent variable
How is cystic fibrosis diagnosed? (FA15 p84) (FA16 p72) (SU p113) (H p2149)
Sweat test : >60mEq/L Cl- on >2 occasions Genetic testing (when sweat test equivocal)
Can present with contraction alkalosis and hypokalemia (ECF effects analogous to a patient taking a loop diuretic) because ECF H2O/Na losses and concomitant renal K/H wasting.
Increased immunoreactive trypsinogen (newborn screening)
What are the common causes of metabolic acidosis with an elevated anion gap? (FA15 p538) (FA16 p543) (SU p150)
Metabolic Acidosis with AG
M: methanol U: uremia D: diabetic ketoacidosis P: propylene glycol I: INH /iron tablets L: lactic acidosis E: ethylene glycol S: Salicylates (aspirin)
You are conducting a study to determine the reduction in risk of developing a relapsing depressive episode with antidepressant X when compared to a placebo treatment. What is this determination called? What is attributable risk, and how is it calculated? (FA15 p50) (FA16 p34) (SU p395)
Relative Risk Reduction vs. Absolute Risk Reduction
**
Absolute risk reduction
Attributable risk = A/(A+B) - C/(C+D)
Given the following clinical situations, classify each as type I, II, III, or IV hypersensitivity. (FA15 p212) (FA16 p204-205) (SU p381) Asthma exacerbation Poison ivy dermatitis Goodpasture syndrome Arthus reaction Anaphylaxis Serum sickness Autoimmune hemolytic anemia Liver transplant rejection Rh incompatibility (erythroblastosis fetalis) TB skin test (PPD)
Type I Type IV Type II Type III Type I Type III Type II Type IV Type II FOUR T's Type IV
What effect does stress have on adipocytes? (Phys p825)
Stress –> Sympathetic activation –> Epi and NE released from adrenal medulla –>
Activation of triglyceride lipase in fat cells –>
Rapid breakdown of TGs and mobilization of fatty acids used by muscles as energy
What is the mechanism of action of leuprolide? (FA15 p596) (FA16 p601) (SU p225)
GnRH analog with agonist properties
Agonist = when used in pulsatile fashion
Antagonist = when used in continuous fashion (down regulates GnRH receptor in pituitary –> decreases FSH/LH)
Used for uterine fibroids, endometriosis, precocious puberty, prostate cancer, infertility
“Leuprolide can be used in lieu of GnRH”
A chronic alcoholic with cirrhosis begins to experience a tremor and blurred vision. You suspect that these symptoms might be due to hyperammonemia due to his progressive liver disease. What is another hereditary cause of hyperammonemia? What are some other findings associated with hyperammonemia? (FA15 p106) (FA16 p93) (SU p298)
Urea cycle enzyme deficiency Ornithine Transcarbamylase (OTC) deficiency - increased ammonia levels - orotic acid in blood and urine - decreased BUN - symptoms of hyperammonemia \+tremor \+slurred speech \+somnolence \+vomiting \+cerebral edema \+ blurred vision
Ammonia accumulation - asterixis, slurring of speech, somnolence, vomiting, cerebral edema, blurring of vision
What features distinguish a thyroglossal duct cyst from a branchial cleft cyst? What is the remnant of the thyroglossal duct? Explain the development of the thyroid gland. (FA15 p312) (FA16 p306) (SU p167-168)
Thyroglossal duct cyst – anterior neck mass that moves with swallowing
Branchial cleft cyst – persistent cervical sinus cyst in lateral neck (does not move with swallowing)
Foramen cecum = remnant of thyroglossal duct
Thyroid tissue derived from endoderm
Thyroid diverticulum arises from primitive pharynx –> descends into neck beginning at foramen cecum –>
thyroid remains connected to tongue by thyroglossal duct –>
If duct persists it becomes the pyramidal lobe of thyroid
Parafollicular cells derived from neural crest cells
A 46-year-old schizophrenic woman has been treated with an atypical antipsychotic with good results for several years. Routine labs reveal a precipitous drop in her WBCs. Which drug is this patient likely taking, and how frequently must her labs be drawn to watch for this problem? (FA15 p521) (FA16 p525) (SU p54) (GG p330)
Atypical antipsychotic that drops WBC – Clozapine
WBC should be monitored weekly
Atypical antipsychotic that drops WBC – Clozapine
WBC should be monitored weekly
Tamoxifen & Raloxifene
SERM (selective estrogen receptor modulators) receptor antagonists in breast and agonists in bone
Other uses –
Osteoporosis
Tamoxifen - risk of endometrial cancer, also “hot flashes”
Both - risk of DVT, PE
How does an anterior shoulder dislocation present differently than a posterior shoulder dislocation? (COA p814-815)
Anterior Dislocation vs. Posterior Dislocation
Arm position
Neurovascular compromise
Classic scenario
Physical exam
External rotation Slight abduction vs. Internal rotation Adduction Unable to externally rotate the arm ----------------------------- Axillary artery Axillary nerve vs. Unusual to have any neurovascular compromise ----------------------------- Blow to the arm while abducted, externally rotated, and extended (blocking a basketball shot) vs. Seizure Electrocution
Prominent acromion process
Loss of normal roundness of shoulder
Appears more angular vs. Posterior shoulder with BULGE
Anterior shoulder relatively flat
Which primary bone tumor fits each of the following descriptions? (FA15 p401, 428) (FA16 p401, 429) (SU p231, 392)
Most common malignancy arising within bone
11;22 translocation
Soap-bubble appearance on x-ray
Onion-skin appearance of bone (layers of new bone in periosteum)
Codman’s triangle (periosteal elevation) on x-ray
May arise from osteochondroma or appear as a primary tumor
Anaplastic small cells, aggressive mets, good chemo response
Most common malignant bone tumor in children
Multiple Myeloma -------------------------- Ewing Sarcoma -------------------------- Giant Cell tumor (Osteoclastoma) -------------------------- Ewing sarcoma -------------------------- Osteosarcoma -------------------------- Chondrosarcoma -------------------------- Ewing Sarcoma -------------------------- Peds: Osteosarcoma
MEMORIZE LAB VALUES IN BONE DISORDERS
A 45-year-old woman receives a kidney transplant and receives cyclosporine as part of her anti-rejection regimen. What is the mechanism of action of cyclosporine? (FA15 p218) (FA16 p212)
(SU p385)
Calcineurin inhibitor
binds cyclophilin, blocks T cell activation of NFATc by preventing IL-2 transcription
Less activation of NFATc and less IL-2
Inhibits T cell growth, differentiation, and activation
You are treating a 63-year-old woman with small cell lung cancer who develops SIADH. She becomes disoriented secondary to hyponatremia. Consequently, you rapidly correct the low serum sodium with demeclocycline and water restriction. The patient’s sodium level and disorientation improve, but several days later the patient develops diplopia. What is the cause of this patient’s diplopia?
(FA15 p456) (FA16 p492)
Osmotic Demyelination Syndrome = Central Pontine Myelinolysis Diplopia Dysarthria Paralysis Locked-in syndrome
What are some of the possible causes of pericarditis? (FA15 p299) (FA16 p294) (SU p91) (R p573)
Pericarditis Infection (coxsackievirus, TB) Neoplasm Autoimmune (SLE, RA) Uremia Cardiovascular (acute STEMI, Dressler syndrome) Radiation therapy
A unilateral lesion to the lateral corticospinal tract results in motor deficits ipsilateral to the lesion. Where in the lateral corticospinal tract is the motor innervation to the legs located? (FA15 p469)
(FA16 p472) (SU p33)
Legs (Lumbosacral) are Lateral in Lateral corticospinal, spinothalamic tracts
In cystic fibrosis thick, mucous secretions inhibit digestive enzymes, which can lead to malabsorption of fat and fat-soluble vitamins. What are the fat-soluble vitamins? What are the corresponding symptoms of fat-soluble vitamin deficiency? (FA15 p88-94, 361) (FA16 p76-81, 358) (SU p113, 461)
D – Rickets in children (bone pain, deformity / osteomalacia in adults (bone pain, muscle weakness) / hypocalcemic tetany
Breast fed infants should receive oral vitamin D
Deficiency is exacerbated by low sun exposure, pigmented skin, prematurity
—————————————
E – Hemolytic anemia / acanthocytosis / muscle weakness / posterior column and spinocerebellar tract demyelination
Fragile RBCs
Muscle weakness
Demyelination of CNS
—————————————
K – neonatal hemorrhage with increased PT & PTT but normal bleeding time
Coagulation factor defects
Osteoporosis
Coronary artery disease
A 22-year-old man recently lost his leg in a tragic accident involving alcohol and heavy machinery. Just prior to discharge, a vigilant nurse informs you that the patient has been very depressed about his lost limb, and she overheard him talking to a friend about just ending his life with his dad’s gun when he gets out of the hospital. What needs to be done? (FA15 p58) (FA16 p42)
Assess seriousness of threat
Evaluate risk factors for depression
- Male sex - Depression - Alcohol use - Organized plan - Access to gun
If it is serious, suggest that the patient remain in the hospital voluntarily
Patient can be hospitalized involuntarily if he/she refuses
What branchial arch derivative abnormality causes facial abnormalities by affecting Meckel’s cartilage? What cranial nerves are affected in this abnormality? From what germ layers are the branchial arches derived? (FA15 p564-566) (FA16 p568-570) (SU p226-227)
1st Arch
Maxillary Process
Mandibular Process
CN V2 and CN V3
Mesoderm – muscles and arteries
Neural Crest - bones and cartilage
KNOW POUCHES, ARCHES, CLEFTS
A 22-year-old man who recently immigrated from a developing country is seen at the county health clinic with a complaint of a chronic but recently worsening productive cough and sinusitis symptoms (e.g., headache). He also mentions to you privately that he and his wife have not been able to have children despite trying for two years. While you note this last complaint, you order a chest x-ray out of concern this man may have TB given his immigration status. The chest x-ray appears backwards on the display, but you realize this man’s heart is actually on the opposite side of his chest. What is the primary defect in this syndrome, and what are the characteristic symptoms/signs? (FA15 p74)
(FA16 p60) (SU p102)
Dextrocardia, recurrent respiratory infection, infertility issues
= Kartagener Syndrome (Primary Ciliary Dyskinesia)
immotile cilia due to a dynein arm defect
A mutation in which proto-oncogene is most commonly associated with Hirschsprung disease?
(R p751)
RET gene mutation
When screening a population for a particular disease, would you rather have a high sensitivity or a high
specificity? (FA15 p49) (FA16 p33) (SU p16) What test is used to screen for HIV? What test is used to
confirm a positive HIV screen? (FA15 p168) (FA16 p158) (SU p353)
High sensitivity
ELISA
Western Blot
How do primary and secondary hyperaldosteronism differ in their effect on plasma renin levels? What
agent is used to treat primary hyperaldosteronism? (FA15 p633) (FA16 p639) (SU p185, 165)
1 Hyperaldosteronism – adrenal adenoma, idiopathic adrenal hyperplasia / HIGH ALDO, low renin
2 Hyperaldosteronism – renovascular HTN, JG cell tumor/ HIGH ALDO HIGH RENIN
Hyperaldosteronism
Tx: Spironolactone
Amyloidosis and sarcoidosis are associated with which cardiomyopathy? What are some other
diseases or conditions associated with this cardiomyopathy? (FA15 p296) (FA16 p291) (SU p89)
Restrictive or Obliterative Cardiomyopathy
Sarcoidosis
Amyloidosis
Post-radiation fibrosis
Endocardial fibroelastosis
Loffler Syndrome – endomyocardial fibrosis with a prominent eosinophilic infiltrate
Hemochromatosis (also dilated cardiomyopathy)
What does the eustachian (auditory) tube connect? What is its purpose? What drug is commonly
prescribed for eustachian tube dysfunction? (H p248-249)
Eustachian (auditory) tube – connects the middle ear to the nasopharynx
Makes the pressure in the middle ear the same as atmosphere pressure
Intranasal steroids to treat
What is the most common renal malignancy in adults? What is the associated gene deletion with this
malignancy? (FA15 p545) (FA16 p550) (SU p163)
Renal Cell carcinoma
- hematuria, flank pain, palpable flank mass
gene deletion = Chromosome 3
associated with von Hippel-Lindau syndrome
A pediatric patient presents with a noticeable right flank mass. The patient’s mother also reports
blood in the patient’s urine. What malignancy would be most likely in this scenario? What is the
WAGR complex? (FA15 p546) (FA16 p551) (SU p163)
Wilm's Tumor (nephroblastoma) 2-4 year old with: -Flank pain -Flank mass -Hematuria
WT1 or WT2 mutation on chromosome 11
WAGR complex Wilms tumor Aniridia (absence of iris) Genitourinary malformations Retardation mental/motor (WT1 deletion)
