USMLE Rx: Week of 7/25/16 Flashcards
What is the main symptomatic difference between IgA nephropathy and PSGN?
IgA nephropathy can be asymptomatic
What causes aortic dissection in Marfans syndrome?
Cystic medial necrosis
What hematologic adverse effect can trimethoprim have?
Megaloblastic anemia
What is essential thrombocytosis?
A myeloproliferative disorder in which platelets are overproduced; symptoms include splenomegaly, TIAs, and burning of the hands and feet
What is the order of organs in which hematopoiesis occurs?
Yolk sac - liver - spleen - bone marrow
Why is pyridoxine given to those taking isoniazid?
Isoniazid inhibits both mycolic acid synthesis (necessary for bacterial cell walls) and pyridoxal kinase; pyridoxal kinase makes GABA, low levels of which can cause seizures
Quinidine can cause what cardiac abnormality?
Torsades
Tetracyclines can cause what two kidney disorders?
Nephrotoxicity and SIADH
SIADH can be revealed by ___________ tests.
water-deprivation
Tuberous sclerosis is associated with what cardiac abnormality?
Rhabdomyoma
Which nerve is commonly injured in posterior hip dislocations?
Inferior gluteal
Inability to stand from sitting or jump indicate what kind of impaired leg movement?
Hip extension
Right-sided heart valve dysfunction can be related to ________ syndrome. What lab test reveals this?
carcinoid; 5-hydroxyindoleacetic acid
Osteomalacia is due to _____________.
vitamin D deficiency
Osteomalacia will have ___________ alkaline phosphatase levels.
normal or low
What levels of calcium, phosphorus, and alkaline phosphatase would indicate Paget’s disease?
Normal Ca and Phos, and increased alk phos
What is osteitis fibrosis cystica?
A disorder in which hyperparathyroidism leads to increased osteoclast activity;
If you have increased calcium (say, from hyperparathyroid syndrome), what will happen to phosphate levels?
They will decrease by kidney excretion
What hematologic abnormality can high homocysteine levels cause?
Hypercoagulable state
What is the medication name of G-CSF?
Filgrastim
What antiarrhythmic can cause pulmonary fibrosis?
Amiodarone
Amiodarone, in addition to causing pulmonary fibrosis, can cause what endocrine abnormalities?
Hypo- and hyperthyroidism
Why does adenosine deaminase deficiency cause immunocompromisation?
ADA is needed to breakdown adenosine nucleotides (such as during cell turnover). Without ADA, adenosine triphosphate builds up, which sends negative feedback on purine synthesis. Lack of purine synthesis is especially damaging to rapidly growing cells, such as lymphocytes in an infection.
Those with SCID are at risk of ____________ infections.
Candida
How does cyclophosphamide work?
It is an alkylating agent.
With what chemotherapy is mesna given?
Cyclophosphamide
In what thalassemia is Barts hemoglobin seen?
Alpha thalassemia major – incompatible with life
What is HbH and in what disorder is it seen?
Beta tetramers – three-gene alpha deletion
What is the difference between montelukast and zileuton?
Montelukast inhibits the receptor for leukotrienes, while zileuton inhibits the synthesis of leukotrienes
What effects do alpha-1 and beta-2 stimulation have on vascular smooth muscle?
Alpha-1 = contract Beta-2 = relax
What activates natural killer cells?
The absence of MHC I
What enzyme is necessary for aldosterone synthesis (the lack of which leads to increased renin from positive feedback)?
21-alpha hydroxylase
Coarctation of the aorta is a feature of which genetic disorder?
Turner syndrome
What tuberculosis drug can cause color-blindness and loss of visual acuity?
Ethambutol
Although both smoking and schistosomiasis infection can cause squamous cell carcinoma of the urothelium, ___________ is more common.
cigarette smoking
Anaerobic metabolism takes place in the __________.
cytosol
Differentiate chronic and acute graft-versus-host disease.
Acute: occurs roughly 5 weeks after transplantation; manifests as dermatitis, hepatitis, and gastroenteritis
Chronic: occurs greater than 100 days after transplantation; manifests as sclerosis of the skin, dry oral mucosa, and GI ulcerations
Which of the sequelae can be decreased with use of antibiotics, PSGN or mitral stenosis?
Mitral stenosis
Differentiate vincristine/vinblastine and the taxols.
Vincristine and vinblastine prevent the microtubules from forming (just like how “Vin” Diesel’s hair never grows), while the taxols prevent depolymerization.
What receptor does rituximab target?
CD20 (“tu”-enty)
What two organs are prone to coagulative necrosis upon hypoxic death?
The heart and the kidneys
How does trastuzumab work?
Antibody-mediated cytotoxicity
What prostaglandins inhibit/promote thrombosis?
TXA2 promotes, PGI2 inhibits
Gout in a patient being treated for cancer can indicate?
Tumor lysis syndrome
Alpha-1-antitrypsin deficiency will generally present before ____________.
age 50
What is obstructive shock?
Pericardial tamponade
How does aortic root dissection lead to death?
Obstructive shock/tamponade
What is the most common fetal neoplasm? What histologic tissue type does it display?
Sacrococcygeal teratoma; multiple tissue types
Colorectal malignancies often present as ____________.
iron-deficiency anemias
Late menopause is a risk factor for _____________.
breast cancer
Direct hernias go through _____________, while indirect hernias go through _____________.
the abdominal wall; the inguinal canal
What happens after ventricular rupture?
Tamponade (not immediate death, but death soon thereafter)
The most common type of muscular dystrophy is ___________.
Duchenne’s
Huntington’s is autosomal __________.
dominant
How does multiple myeloma injure the kidneys?
It creates large, granular casts that block tubules
What immunoglobulin is most common in multiple myeloma?
IgG
What does angiotensin II do to smooth muscle cells?
Causes contraction
Explain the “Hot T-Bone stEAK” mnemonic.
This mnemonic is for IL 1 - IL 6: IL-1: Fever (hot) IL-2: T-cell differentiation (T) IL-3: Bone marrow stimulus (bone) IL-4: IgE production (stEak) IL-5: IgA production (steAk) IL-6: stimulate akute-phase proteins (steaK)
What cervical roots supply the musculocutaneous nerve?
Lateral cord (from C5 and C6)
What is the most common cause of death in a child with congenital diaphragmatic hernia?
Pulmonary hypoplasia
What kinds of anemia are associated with glossitis?
Iron, B12, and folate deficiency
What is the mnemonic for drugs that can induce lupus?
HIPP-E: Hydralazine Isoniazid Procainimide Phenytoin Enterecept
Pregnancy can cause ____________ vena cava syndrome, relieved by __________.
inferior; lying on the left side
Describe maple syrup urine disease.
An AR disorder in which the enzyme branched-chain alpha-keto acid dehydrogenase is deficient; as a result, isoleucine, leucine, and valine accumulate in the urine; undegraded, these enzymes cause metabolic acidosis and mental retardation
Which type of cell does GM-CSF affect?
The myeloid stem cell–progenitor of platelets, neutrophils, basophils, eosinophils, and macrophages
Describe the pathophysiology of McArdle disease.
Congenital lack of myophosphorylase that leads to intolerance of anaerobic metabolism; muscle cramps, myoglobinuria, and lack of venous lactate increase with exercise are all features
In addition to effacement of podocyte slits, what else causes symptoms in minimal change disease?
Loss of heparan sulfate in the glomerular basement membrane
The acid-fast stain is also called ________.
Ziehl-Neelsen staining
What can cause increased toxicity of digoxin?
Hypokalemia, because digoxin binds to the same receptor as potassium on the NaK pump; in the absence of K, more digoxin will bind
What is the best first-line treatment for candidiasis?
Nystatin
How does nystatin work?
It binds to ergosterol (a cholesterol specific to fungal membranes) and pokes holes in the membrane
What antiparasitics work by interrupting microtubule function?
Albendazole and mebendazole
The first-line treatment for pneumocystis jirovecii is ___________; if a patient has a sulfa allergy, then give ___________.
bactrim; pentamidine
What pharyngeal arch does the thymus develop from?
Third pouch
