February UWorld Flashcards
Presence of this serological marker increases the risk of vertical transmission of Hep B
HBeAg
Most specific marker for diagnosis of acute Hep B infection
Anti-HBcAg IgM
First line tx for generalized anxiety disorder
SSRIs (fluoxetine, paroxetine, sertraline, citalopram)
[FLashbacks PARalyze SEnior CITizens]
SNRIs (venlafaxine, duloxetine)
Strep pneumoniae vaccine contains what components
Adults- Polysaccharide vaccine
Children- Conjugate vaccine
Ethambutol use and side effect
TB
Optic neuropathy
Spironolactone location of action in nephron; ion effects
Principal cells of collecting tubules;
Causes decreased Na reabsorption, decreased K/H secretion
Intellectual disability in child, history of seizures, abnormal pallor of catecholaminergic brain nuclei, musty odor- Dx?
Phenylkentonuria (deficiency of phenylalanine hydroxylase)
Inducers of CYP450
Chronic alcohol use, St. John’s wort, phenytoin, phenobarbital, nevirapine, rifampin, griseofulvin, carbamazepine [Chronic alcoholics STeal PHEN-PHEN and NEVer Refuse GReasy CARBs]
Most important prognostic factor of PSGN
Age (younger = better prognosis)
Enzymes inhibited by lead
Ferrochelatase and d-aminolevulinic acid (ALA) dehydratase
Symptoms of lead poisoning
Anemia, ALA accumulation, and elevated zinc protoporphyrin;
Long term: neurotoxicity
Rett syndrome
Neurodevelopment disorder mainly in girls. Normal development until 5-18 mo; loss of motor and language skills; stereotypic hand movements; MECP2 mutation
Budding yeast with thick capsule
Cryptococcus neoformans
Diagnosis of cryptococcus
India ink stain of CSF shows halos due to polysaccharide capsule
Dorsal and ventral pancreatic buds form what structures, respectively
Pancreatic tail, body, most of the head, and small accessory pancreatic duct;
Uncinate process, portion of pancreatic head, and proximal portion of the main pancreatic duct
Phenotypic mixing
Host cell is coinfected with two viral strains and progeny virions contain unchanged parental genome from one strain and nucleocapsid (or envelope) proteins from the other strain
Chi-square test is used for what
To test association between two categorical variables
Anastomosis that connects SMA and IMA
Marginal artery
Function and location of enhancer sequences in DNA
Increase rate of transcription;
May be located upstream, downstream, or within introns of the gene
Function and location of promote region
Site where RNA pol3 bind to DNA- functions to initiate transcription;
Located 25-75 bases upstream from associated gene
Immune response to pulmonary TB infection
CD4+ Th1 lymphocytes and macrophages (the latter mediated by IFNg and IL2)
Venous component of internal and external hemorrhoids drain to what veins, respectively
Internal: middle rectal vein -> internal iliac vein
And superior rectal vein -> inferior mesenteric vein
External: inferior rectal veins -> internal iliac vein
Inheritance pattern of NF1
Single gene AD
NF1 gene on chromosome 17
Presentation of NF1
Variable, can include all or none: Cafe-au-lait spots Neurofibromas Lisch nodules in eyes Pseudoarthrosis Other tumors (meningiomas, astrocytomas, gliomas, pheochromocytomas)
Anti-Rh immunoglobulin belongs to which class of Ab?
IgG
Intestinal atresia of the midgut is most like due to
Vascular occlusion
Intellectual disability, gait/posture abnormality, eczema, and musty body odor are signs of
PKU
Omalizumab MOA and clinical use
Anti-IgE monoclonal Ab (binds mostly unbound serum IgE and blocks FcERI);
Asthma add-on therapy for sever allergic asthma
Pleiotropy
Occurrence of multiple phenotypic manifestations, often in different organ systems, from a single gene
Iliohypogastric nerve- motor and sensory functions
Motor: anterolateral abdominal wall muscles
Sensory: innervates skin in suprapubic region (anterior branch); innervates gluteal region (lateral branch)
Northern, Western, Southwestern, Southern blots are used for what
mRNA, proteins, DNA-bound proteins, DNA, respectively
Coronary dominance is determined by
…the coronary artery supplying the posterior descending artery (PDA)
Which branch supplies blood to the AV node
Posterior descending artery
Where does the posterior descending artery originate from
Right coronary artery (70% of population); Left circumflex (10%); codominant (20%)
What causes DiGeorge syndrome
Maldevelopment of the third and fourth pharyngeal pouch derivatives
What area of the LN is poorly developed in DiGeorge syndrome
Paracortex
Marfan syndrome is a defect in what
Fibrillin-1 gene
What is fibrillin-1; defect in this causes what dz
Major component of microfibrils that form a sheath around elastin fibers; Marfan syndrome
Why does verapamil not affect skeletal muscles
Verapamil blocks L-type calcium channels on plasma membrane; skeletal muscles do not depend on extracellular calcium influx to cause calcium release from SR
DOC for PTSD
SSRI, or SNRI
Immunologic mechanism behind hyperacute transplant rejection
Preformed IgG antibodies against graft in recipient’s circulation
External hemorrhoids are innervated by
Inferior rectal nerve, a branch of the pudendal nerve
Fetal hemoglobin is made of what subunits
2 alpha and 2 gamma protein subunits
What is bacillary angiomatosis and what causes it
Benign red-purple papular skin lesions; caused by Bartonella infection (cat-scratch dz)
Mechanism behind granulomatous diseases (sarcoidosis, TB) causing hypercalcemia
They have PTH-independent conversion of calcitriol (active form of Vit D) due to expression of 1-a-hydroxylase activity in activated macrophages
Presentation of hemochromatosis
Classic triad of micronodular cirrhosis, diabetes mellitus, and skin pigmentation
Cause of annular pancreas
Failure of the ventral pancreatic bud to properly migrate and fuse with the dorsal bud during the 7th and 8th week of development
What is genomic imprinting, and what causes it
Phenomena in which an offspring’s genes are expressed in a paren-specific manner;
Cytosine methylation by S-adenosyl-methionine (SAM)
Case-control study
Selects individuals with a particular disease (cases), individuals without that disease (controls), and then evaluates previous exposure status
Conn syndrome
Primary hyperaldosteronism due to aldosterone producing adenoma
t(15;17) is translocation of what two genes; what condition does it cause
Retinoic acid receptor alpha (RARA) on 17 and promyelocytic leukemia (PML) on 17;
Acute Promyelocytic Leukemia (APML)
Heart sound heart with atrial left-to-right shunt
Wide and fixed splitting of S2
Stop codons
UAA, UGA, UAG
Decreased AFP and increased nuchal translucency on ultrasonography
Down syndrome
Meniere disease presentation
Triad of tinnitus in affected ear, vertigo, and sensorineural hearing loss
Gonadal abnormalities in Turner Syndrome
Streak ovaries, amenorrhea, infertility
Turner syndrome karyotype
45 X
Extragonadal manifestations of Turner syndrome
Short stature, shield chest, webbed neck, bicuspid aortic valve, coarctation of aorta, horseshoe kidney
Reassortment
Mixing of genomic segments in segmented viruses that infect the same host cell (genetic shift of influenza A)
Hormone-sensitive lipase
Enzyme found in adipose tissue that catalyzes breakdown of TG into FFA and glycerol; activated by stress hormones (catecholamines, glucagon, ACTH) and inhibited by insulin
MOA of fibrates
Activate peroxisome proliferator-activated receptor alpha (PPAR-a), which increases LPL activity
Predicted respiratory compensation for MAc
Pco2 = 1.5 [HCO3-] + 8 +/- 2
Cause of staphylcoccal scalded skin syndrome; sxs
Production of exotoxin exfoliatin by staph species; widespread epidermal sloughing, even with gentle pressure (Nicholsky’s sign)
Organophosphates- MOA and end organ effects
AChE inhibitor;
muscle weakness, paralysis, lethargy, seizures, miosis, bradycardia, increased lacrimation/salivation
Fungus with polysaccharid capsule; stains red on mucicarmine stain and has a clear unstained zone with India ink stain
Cryptococcus neoformans
Adenomyosis; sxs
Presence of endometrial glandular tissue within the myometrium;
Heavy menstrual bleeding, dysmenorrhea, uniformly enlarged uterus
Role of voltage-gated calcium channels in neurotransmission
Fusion and release of NT vesicles into the synaptic cleft
Caseating granulomas consist of immunological cells; what surface markers do these cells display
Epithelioid macrophages; CD14
Embryologic defect in hydrocele
Patent processus vaginalis
Screening test for Celiac dz
Serology test for IgA anti-endomysial and anti-tissue transglutaminase antibodies
Bordatella pertussis characteristics
Gram - coccobacillus; Adenylate cyclase and pertussis toxin; tracheal cytotoxin
Type 2 error in a study
Concluding that there is no difference between groups when one truly exists
Power of a study
1 - B (type 2 error)
Blood supply to the ovary is in what ligament
Infundibulopelvic ligament (suspensory ligament of the ovary)
Causes of polyhydramnios
Fetal GI obstruction (esophageal, duodenal, or intestinal atresia), anencephaly, high fetal cardiac output (anemia)
Serum B-hCG test can detect pregnancy ___ days after fertilization/implantation;
Urine can detect ___ days after
8;
14
Koilocyte is a hallmark sign of infection with what pathogen
HPV
Koilocyte characteristics
Pyknotic, superficial or immature squamous cells with a dense, irregularly staining cytoplasm and perinuclear halo-like clearing;
raisinoid appearance of nucleus
Mechanism of exchange of genes between 2 nonsegmented, double-stranded DNA genomes
Recombination
Uterine leiomyoma; symptoms
Monoclonal tumor;
Uterine enlargement causing bulk-related symptoms (constipation if on posterior uterine wall presses on colon, urinary urgency/imcomplete emptying if uterus is displaced upwards); can cause reproductive difficulties if in the uterine cavity
3 main causes of HIV-associated esophagitis; endoscopic findings of each
Candida albicans (pseudomembranes), HSV-1 (“punched out” ulcers), CMV (linear ulcerations)
Microscopic findings of HSV-1 and CMV
HSV-1: eosinophilic intranuclear inclusions (Cowdry type A) in multinuclear squamous cells
CMV: Intranuclear and cytoplasmic inclusions
Inactivated influenza vaccine has what effect
Induces neutralizing antibodies against the hemagglutinin antigen; prevents live virus from entering cells via endocytosis
Live-attenuated viral vaccines induce what immunological response
Stimulate MHC class I antigen-processing pathway and can generate cytotoxic CD8+ T lymphocytes that kill infected cells
Most vulnerable structure to injury during hysterectomy
Ureter
Monosaccharide with fastest rate of metabolism in the glycolytic pathway
Fructose-1-phosphate bc it bypasses phosphofructokinase (a major regulatory step in glycolysis)
Underlying mechanism for Turner syndrome
Paternal meiotic non-disjunction
Fever, malaise, maculopapular rash of palms and soles
Treponemal infection (syphilis)
Projection
Immature defense mechanism involving the misattribution of one’s unacceptable feelings or thoughts to another person who does not actually have them (eg, boy thinks his parents are angry at him while they are going through divorce, when it is actually him that’s angry)
Dizygotic twins: mono- or di- chorionic/amniotic
Dichorionic diamniotic
Monozygotic twins: mono- or di- chorionic/amniotic
Early septation (0-4 days): dichorionic diamniotic Septation at 5-7 days: monochorionic diamniotic Late sepatation (8-12 days): monochorionic monoamniotic (high fetal fatality rate)
Virchow’s triad
Stasis, hypercoagulability, endothelial damage (exposed collage triggers coag cascade)
Ovarian venous drainage
R ovarian vein drains into IVC;
L ovarian vein drains into L renal vein
Serological markers seen with HBV vaccination
Anti-HBs
Serological markers seen with HBV recovery
Anti-HBs and anti-HBc IgG
Down syndrome quadruple screen results (a-fetoprotein, unconjugated estriol, B-hCG, inhibin A)
Low maternal serum AFP, low estriol, high B-hCG, high inhibin A
% of data within 1, 2, and 3 standard deviations
68%, 95%, 99.7%
ACh release form presynaptic terminal vesicles at the NMJ depends on what substance
Ca
Major immune mechanism against giardiasis
CD4+ T helper cells, and secretory IgA production (prevents and clears infection by binding to trophozoites and impairing their adherence to the upper small-bowel mucosa)
Thiazide diuretics MOA
Inhibit Na/Cl cotransporter in early distal tubule
Familial hypocalciuric hypercalcemia
benign AD disorder caused by defective Ca-sensing by parathyroid and renal tubule cells;
prevents PTH from being suppressed in response to an increase in serum Ca
Lab findings that differentiate familiar hypocalciuric hypercalcemia from primary hyperparathyroidism
Both will have elevated Ca and PTH levels, but FHH will have low urinary Ca excretion due to impaired renal Ca sensing
MOA of zafirlukast and montelukast
Leukotriene D4 antagonists;
Increases airway caliber and reduces mucosal inflammation
Side effects of niacin
Flushing, hyperglycemia, hepatotoxicity, and decreased renal excretion of uric acid (increased risk for acute gouty arthritis)
Pts with Down syndrome are at increased risk of what cancer
Acute lymphoblastic leukemia and acute myelogenous leukemia
Gram + rod with tumbling motility
Listeria monocytogenes
Confounding
When a perceived association between an exposure and an outcome is actually explained by a confounding variable associated with both the exposure and the outcome (eg, age is a confounding variable when comparing IQ and shoe size; if controlled for age, there is no correlation between the two)
HSV-1 characteristics
DNA, double-stranded, enveloped
Type IV hypersensitivity
Delayed T-cell mediated type; sensitized T cells encounter antigen and release cytokines that lead to macrophage activation; ex: contact dermatitis, GvH dz, MS
Head “pounding” with involuntary head bobbing
Widened pulse pressure
Widened pulse pressure with large stroke volume and heart murmur
Aortic regurgitation
Classic triad of congenital rubella syndrome
PDA (or pulmonary arterial hypoplasia), cataracts, and deafness, +/- “blueberry muffin” rash
Live attenuated vaccines are for what diseases
Smallpox, yellow fever, rotavirus, chickenpox, Sabin polio virus, MMR, Influenza (intranasal)
Difference between PKU d/t phenylalanine hydroxylase deficiency vs dihydrobiopterin reductase deficiency is…
Phenylalanine hydroxylase def. can be corrected by limiting phenylalanine intake and supplementing tyrosine; BH2 reductase is required to form DOPA (which is required for dopamine), so prolactemia is present too (from lack of negative feedback in pituitary)
Nitrates effects
Primary venodilators that increase peripheral venous capacitance –> lowers LVEDP; modest effect on arteriolar dilation
Gomori trichrome stain of muscle biopsy showing muscle fibers with blotchy red appearance
Mitochondrial myopathies
Causes of SCID
MC- Defective IL-2R gamma chain (x-linked)
Adenosine deaminase deficiency (AR)
Sxs of SCID
Failure to thrive, chronic diarrhea, thrush, recurrent viral/bacterial/fungal/protozoal infections
Findings of SCID
Decreased T-cell receptor excision circles (TRECs); absence of thymic shadow, germinal centers, and T cells
Side effects of lithium
Diabetes insipidus, hypothyroidism, tremor
Symptoms of acute intermittent porphyrias
5 Ps: Painful abdomen, Port wine-colored urine, Polyneuropathy, Psychological disturbances, Precipitated by drugs, alcohol, starvation
Treatment for AIP
Glucose and Heme (both inhibit ALA synthase)
AIP is caused by deficiency of what enzyme
Porphobilinogen deaminase
Vincristine/vinblastine MOA; side effects
Bind B-tubulin and inhibit its polymerization into microtubules –> M-phase arrest;
SE: neurotoxicity (peripheral neuropathy), constipation
Candida albicans morphology
Budding yeast with pseudohyphae
Signs of increased intracranial pressure in newborn
AMS, enlarging head circumference/fontanelle, downward-driven eyes
Telomerase function
RNA-dependent DNA polymerase that synthesizes telomeric DNA sequences that can replace the lost chromosomal ends of telomeres (cancer cells have increased activity of telomerase to allow continued proliferation)
Presentation of Wiskott-Aldrich syndrome
Thrombocytopenia, Eczema, Recurrent infections (combined B- and T-lymphocyte deficiency) (WATER)
Sickle cell patients are predisposed to infections by…
Encapsulated organisms (pneumococcal)
Common presentation of sickle cell dz in children
Dactylitis (small infarctions in bones of extremities)
Mechanism behind warfarin-induced skin necrosis; how to avoid this
Transient hypercoagulability state d/t shorter half-life of Protein C;
“heparin bridge”- coadministration of heparin to combat transient hypercoag
MOA of enoxaparin
LMWH; binds and activates ATIII, increasing its affinity for factor Xa; end effect- prevents factor Xa from activating prothromin –> thrombin
Fibrinolytic drugs
tPA, alteplase, reteplase, streptokinase, tenecteplase
PECAM is responsible for what step in leukocyte extravasation
Diapedesis/transmigration: WBC travels between endothelial cells and exits blood vessels
Leukocyte adhesion deficiency type 1: what’s the defect and how does it present
Defect in LFA-1 integrin (CD18) protein on phagocytes;
Recurrent bacterial skin and mucosal infections W/O pus formation; delayed separation of umbilical cord (>30 days)
Follicular lymphoma genetics and effects
t(14;18)- translocation of heavy-chain Ig (14) and BCL-2 (18);
Overexpression of bcl-2 (inhibits apoptosis); presents with painless “waxing and waning” LAD
Hypocalcemia following RBC/whole blood transfusion is d/t…
Citrate anticoagulant in whole blood chelates Ca and Mg, reducing their blood levels
Complement binding site on IgG and IgM is located where on Ig molecule?
Fc portion, closer to the hinge region
Absence of B cells = malformation of which region of LNs?
Germinal centers (contains proliferating B cells) and primary lymphoid follicles
Red cell index most specific for spherocytosis
Elevated mean corpuscular hemoglobin concentration (MCHC); small, round RBCs with less SA and less cyto => increased concentration of Hb within cell
Rivaroxaban/apixaban: MOA and uses
MOA: directly inhibit factor Xa
Uses: DVT/PE (riva) and stroke prophylaxis in Afib patients
Human multi-drug resistance gene (MDR1) codes for what?
P-glycoprotein (transmembrane ATP-dependent efflux pump protein): allows tumor cells to reduce chemo drugs in cytosol
Folate deficiency inhibits formation of…
dTMP
MC viral cause of aplastic crisis
Parvovirus B19
Findings necessary to diagnose TTP
Microangiopathic hemolytic anemia and thrombocytopenia
Desmopressin MOA in treating hemophilia and von Willebrand dz
Increases vWF release from endothelial cells (W-P bodies); increases circulating factor VIII levels
Major clinical manifestations of Factor V Leiden
DVT (–> PE), cerebral vein thromboses, recurrent pregnancy loss
Heparin reversal agent
Protamine sulfate
Heparin MOA
Increases effect of ATIII; lowers the activity of thrombin (factor IIa) and factor Xa
Rapid reversal agent against warfarin
Fresh frozen plasma (vit K takes days since new coag factors have to be synthesized)
Painless, waxing/waning LAD
Follicular lymphoma- t(14;18) IgH;bcl-2
What feature of a LN biopsy would be most indicative of malignancy?
Monoclonal lymphocytic proliferation (polyclonal = benign)
Nevirapine and efavirenz: use and MOA
Use: antiretroviral drugs for HIV
MOA: Nonnucleoside reverse transcriptase inhibitors (NNRTIs)- inhibit synthesis of viral DNA from the RNA template
Monoclonal antibody against HER-2
Trastuzumab
Peau d’orange and dermal lymphatic invasion
Inflammatory breast cancer
Why don’t localized intestinal carcinoid tumors produce carcinoid syndrome?
Their secretory products (serotonin, bradykinin, PG) are metabolized by liver via first-pass effect. Must metastasize to liver to bypass metabolism and cause carcinoid syndrome (flushing, watery diarrhea, bronchospasm)
Glanzmann thrombasthenia
Defect in platelet plug formation due to decreased GpIIb/IIIa
GpIIb/IIIa inhibitors
Abciximab, eptifibitide, tirofiban
Treatment for constitutively active tyrosine kinase activity
Imatinib
Why are patients with sickle cell dz or other hemolytic anemias more prone to develop folic acid deficiency?
Bc of increased rate of erythrocyte turnover
Pathophys of sideroblastic anemia
Decreased heme synthesis due to X-linked defect in d-ALA synthase gene
Sideroblastic anemia may be caused by what drug
Isoniazid (inhibits pyridoxine phosphokinase, leading to pyridoxine deficiency- pyridoxine is the cofactor for d-ALA synthase)
Apoptosis is mediated via what protein
Caspase
Rasburicase MOA and clinical use
MOA: recombinant version of urate oxidase- catalyzes conversion of uric acid to allantoin (5-10x more soluble than uric acid = increased excretion)
Use: Prevents and treats hyperuricemia and the resulting renal manifestations of tumor lysis syndrome
Protein that regulates G1 –> S phase transition
Retinoblastoma (Rb) protein;
Active Rb is hypophosphorylated and serves as a “brake” to stop the cell from dividing
Inactive Rb is hyperphosphorylated
Adverse effect of TMP
Megaloblastic anemia, leukopenia, granulocytopenia
“TMP Treats Marrow Poorly)
Dermatomyositis
Systemic AI dz characterized by proximal muscle weakness; heliotrope rash (erythematous periorbital); Gottron’s papules (raised erythematous plaques over the joints and bony prominences of the hands); muscle biopsy is diagnostic and shows mononuclear perimysial infiltrates and atrophy with CD4+ T cells; may occur as paraneoplastic syndrome
What are integrins
Membrane proteins that maintain integrity of basolateral membrane by binding to collagen and laminin in basement membrane (also binds fibronectin)
Hypersegmented neutrophils are associated with…
Vit. B12 or folate deficiency
Auer rods are seen in what disorder
AML
Difference in immunostaining of B cell leukemia and T cell leukemia
B cell will stain TdT+, CD10+, CD19+
T cell will stain TdT+, CD2-8+
Translocation seen in Burkitt lymphoma
t(8;14)– translocation of c-myc (8) and heavy-chain Ig (14)
c-myc functions as a transcription activator
How to distinguish CML from leukemoid reaction
CML will have decreased leukocyte alkaline phosphatase (LAP); leukemoid reactions have increased LAP
Translocation seen in CML
t(9;22), BCR-ABL;
Increases tyrosine kinase activity
Treatment for CML
Imatinib (tyrosine kinase inhibitor)
What does an M spike on serum protein electrophoresis indicate?
Multiple myeloma
PNH pathophysiology; clinical presentation; treatment
Impaired synthesis of GPI anchor for CD55+ DAF that protects RBC from complement leads to complement-mediated intravascular hemolysis;
Pres: triad of hemolytic anemia, pancytopenia, and venous thrombosis
Tx: Eculizumab (terminal complement inhibitor)
Amyl nitrite is used for ____ poisoning
Cyanide (Nitrites are oxidizing substances that induce production of metHb, which binds to cyanide, preventing its binding to mitochondrial cytochrome enzymes)
Key growth factors for angiogenesis
Vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF)
Things that can induce hemolytic episodes in G6PD deficiency
Sulfa drugs (TMP-SMX), antimalarials, infections, fava beans
Gene mutation associated with chronic myeloproliferative disorders
V617F JAK2 mutation
Drugs that can cause aplastic anemia
Chloramphenicol, benzenes, carbamazepines, alkylating agents, antimetabolites, sulfonamides
Treatment for Human epidermal growth factor receptor 2 positive breast cancer
Trastuzumab (tyrosine kinase inhibitor bc HER2 is a TK)
6-mercaptopurine is activated by what enzyme? Inactivated by what enzyme
Activated by hypoxanthine-guanine phosphoribosyl transferase (HGPRT);
Inactivated by thiopurine methyltransferase (TPMT) and xanthine oxidase (XO);
Must be careful if pt is on allopurinol (XO inhibitor) as it increases toxicity of 6-MP
Histological characteristic of eosinophil
Bi-lobed nucleus, packed with large eosinophilic (red or pink) granules of uniform size
Unilateral pulmonary opacification on xray with same side tracheal deviation is d/t…
Obstructive lesion in mainstem bronchus, which causes obstructive atelectasis and complete lung collapse (as air diffuses out of alveoli);
Pleural effusion will cause the same xray finding, but with contralateral tracheal deviation
Why do reticulocytes appear blue on Wright-Giemsa stain?
Residual ribosomal RNA
MOA of varenicline
Partial agonist of nAChR in CNS;
Reduces withdrawal by partially activating receptors;
Attenuates the rewarding effects of smoking by blocking attachment of nicotine
MOA of raltegravir
HIV antiviral- integrase inhibitor (prevents HIV double-stranded DNA from integrating with host DNA, which prevents viral mRNA transcription)
Transformation (bacteria) definition; which organisms can undergo transformation
Ability to take up naked DNA;
S. pneumo, H. influenza type b, Neisseria (SHiN)
Myeloperoxidase
Blue-green heme-containing enzyme that gives sputum its color; released by neutrophil granules to form bleach
Function of leukotriene B4
Neutrophil chemotactic agent
Cause of high chloride content in venous RBCs
“Chloride shift”- as CO2 enters RBC, CA turns it into H+ and HCO3-, which then diffuse out of the RBC. Cl- ions diffuse into the RBC to maintain electrical neutrality
Metalloproteinase
Enzyme that degrades ECM and BM;
Normal process of tissue remodeling;
Increased expression in tumor cells (invasion through BM and connective tissue
Reid index- how to calculate and what does it indicate
Thickness of mucous gland layer/thickness of bronchial wall;
Index > 0.4 indicates chronic bronchitis
Chronic granulomatous disease- Cause, presentation,
Defect in NADPH oxidase in neutrophil and macrophage phagolysosomes;
Recurrent bacterial and fungal infections by catalase + organisms
Catalase + organisms
Nocardia, pseudomonas, listeria, aspergillus, candida, E. coli, staphylococci, serratia, B cepacia, H pylori (CATs Need PLACESS to Belch Hairballs)
Calcified, supradiaphragmatic and pleural plaques; ferriginous bodies found in alveolar sputum
Asbestosis
Airway/GI infections, AI dz, atopy, anaphylaxis to transfusion
Selective IgA deficiency
Interstitial fibrosis presents with increased or decreased radial traction on airway walls
Increased
Ghon complex
Hilar LAD + peripheral granulomatous lesion in middle or lower lung lobe;
Primary TB infection
Inhibitors of P450
Acute alcohol abuse, ritonavir, amiodarone, cimetidine, ketoconazole, sulfonamides, isoniazid, grapefruit juice, quinidine, macrolides (except azithro)
(AAA RACKS In GQ Magazine
Where is surfactant stored/released from?
Lamellar bodies of TII pneumocytes
Hirschsprung is a/w with disorder
Down syndrome
Inspissated fecal mass obstructing the ileum is a finding in what disorder
CF
Major stimulator of central chemoreceptors
Increase in PaCO2
Major stimulator of peripheral chemoreceptors (carotid and aortic bodies)
Primarily hypoxemia (also PaCO2 increase and pH decrease)
Peptostreptococcus, fusobacterium, bacteroides, and provatella cause what
Aspiration causes lung abscess
H. influenzae type b capsule contains…
Polyribosylribitol phosphate (PRP)
Long bone fracture followed by hypoxemia, petechial rash over chest, and neurologic abnormalities is indicative of…
Fat embolism
MOA of 5-FU
Thymidylate synthase
MOA of methotrexate
Inhibits dihydrofolate reductase
Effect of leucovorin on methotrexate and 5-FU
Leucovorin is folinic acid (THF derivative) that “rescues” methotrexate toxicity but worsens 5-FU toxicity
Methacoline MOA and clinical use
MOA: muscarinic cholinergic agonist
Use: Bronchoprovocation technique for asthma diagnosis; causes bronchoconstriction and increased airway secretions
CREST syndrome
Localized variant of systemic scleroderma (triad of autoimmunity, noninflammatory vasculopathy, and collagen deposition with fibrosis);
Calcinosis, Raynaud, Esophageal dysmotility, sclerodactyly, telangiectasia
Causes of cheyne-stokes breathing
Advanced CHF (cycle of hyperventilation causing hypocapnia, which causes periods of apnea, which causes hypercapnia, which causes hyperventilation), neurologic dz (stroke, brain tumor, traumatic brain injury)
Hair cell leukemia
Mature B-cell tumor; cells have filamentous projections; marrow fibrosis causes dry tap; massive splenomegaly, stains TRAP; tx = cladribine
Deficiency of what vitamin predisposes to squamous metaplasia
Vit A (vit A and it’s metabolite retinoic acid are required to maintain specialized epithelia, such as mucus-secreting columnar epithelium)
Histological findings of mesothelioma
Psammoma bodies; long, slender microvilli; abundant tonofilaments
Particles lodged within terminal bronchioles are removed by what mechanism
Mucociliary clearance;
Particles distal to this are removed by macrophages
Legionella: sxs, lab findings, diagnosis
Sxs: High fever, pneumonia, diarrhea, HA/confusion
Lab findings: hyponatremia
Diagnosis: urine antigen test
Function of TNF-a
Mediates septic shock. Activates endothelium. Causes WBC recruitment, vascular leak. Causes cachexia in malignancy.
Factor V Leiden: pathophys; complications
Production of mutant factor V that is resistant to degradation by activated protein C;
Complications include DVT, cerebral vein thromboses, and recurrent pregnancy loss
Sxs of spinal metastasis; MC cancers that met to bone
Constant pain, not responsive to position changes, worse at night.
Prostate, breast, kidney, thyroid, lung (PB/KTL- “lead kettle”)
Pathogenesis of chronic transplant rejection
CD4+ T cells respond to recipient APCs presenting donor peptides, including allogeneic MHC
Effect of pCO2 on cerebral blood flow
Decrease in pCO2 (hyperventilation) causes vasoconstriction of cerebral vessels, causing a decrease in CBF
Celecoxib MOA; benefits over other NSAIDs
Reversibly inhibits COX2, which mediates inflammation and pain;
Spares COX1, which helps maintain gastric mucosa; thus does not have corrosive effects of other NSAIDs on GI lining;
Spares platelet function as TXA2 production is dependent on COX1
Primary biliary cirrhosis: pathophysiology; clinical features; biopsy findings
Pathophys: Chronic AI liver dz characterized by destruction of small to mid-sized intrahepatic ducts with resulting cholestasis;
Clinical fts: fatigue, itching, hepatomegaly
Biopsy findings: patchy lymphocytic inflammation with destruction of intrahepatic ducts; necrosis and micronodular regeneration of periportal tissues
Uses for 5-HT3 antagonist
N/V caused by GI irritants (infections, CTX, distention)
Replication of HBV
Partial dsDNA -> + RNA template -> partial dsDNA progeny
Anti-HAV IgG indicates what
Prior infection and/or prior vaccination; protects against reinfection
Presentation of tracheoesophageal fistula with esophageal atresia in neonate
Drooling (inability to swallow saliva), choking, coughing, cyanosis with feeds (d/t reflux of foods and aspiration);
Xray will show stomach bubble due to air from trachea entering distal esophagus
Lynch syndrome (HNPCC)
AD mutation of DNA mismatch repair genes (MSH2 & MLH1) with subsequent microsatellite instability
Function of IL-10
Attenuates inflammatory response; decreases expression of MHCII and Th1 cytokines (IFN-y and IL-2); inhibits activated macrophages and dendritic cells (TGF-B also attenuates the immune response)
Indications for Vitamin D supplementation in infants
Exclusively breast fed, low sunlight exposure, dark pigmented skin
Indications for iron supplementation in infants
Low birth weight/Pre-term
Tx for H. pylori
Clarithromycin, amoxicillin, PPI
Most specific test for acute cholecystitis
Nuclear medicine hepatobiliary scan (cholescintigraphy)
What stains magenta in a PAS stain? What is a PAS stain useful for?
Glycogen and mucopolysaccharides (PASs the Sugar);
Useful for diagnosing Whipple disease (Tropheryma whipplei)
Function of pudendal nerve
Sensory: external genitalia and skin around anus/perineum
Motor: pelvic floor muscles, external urethral and anal sphincters
Damage to pudendal nerve causes what sxs
Fecal incontinence, urinary incontinence, sexual dysfunction, perineal pain
Drugs used for methicillin-resistant Staph
Vancomycin, daptomycin, linezolid
Daptomycin: mechanism, clinical use, and adverse effects
MOA: lipopeptide used for Gram + organisms; creates transmembrane channels that cause intracellular ion leakage
Use: S. aureus skin infections (esp. MRSA), bacteremia, VRE, endocarditis
SE: myopathy, CPK increase
DOC for supraventricular tachycardia
Adenosine
IL-8
Released by macrophages;
Induces neutrophil chemotaxis and phagocytosis
Mechanism of glycogen synthesis upgregulation by insulin
Insulin binds cell surface receptors which have intrinsic tyrosine kinase activity; IRS-1 is phosphorylated, which activates phosphatidylinositol-3-kinase (PI3K), which then activates protein phosphatase, which dephosphorylates glycogen synthase (activating it)
“Blowing” early decrescendo murmur
Aortic regurgitation
Glioblastoma features
Highly malignant primary brain tumor; found in cerebral hemispheres, can cross corpus callosum (“butterfly glioma”); “psudopalisading” pleomorphic tumor cells border central areas of necrosis and hemorrhage (seen grossly); stain astrocytes for GFAP
DOC for OCD
SSRI
Bicuspid aortic valve most likely leads to…
aortic stenosis in 50s; abnormally shaped valve can cause hemodynamic stress, accelerating the aging process and causing premature atherosclerosis and calcification of the aortic valve
Abusive head trauma in a baby can result in
subdural hematoma and retinal hemorrhages
Choriocarcinoma: What is it, when/how can it develop, features seen, lab findings, how/where does it spread, tx, prognosis
Malignant ovarian neoplasm of the ovary (malignancy of trophoblastic tissue);
Can develop during or after pregnancy in mother or baby;
NO chorionic villi present, increased frequency of bilateral/multiple theca-lutein cysts;
Increased B-hCG;
Hematogenous spread- lungs most common (SOB, hemoptysis);
Very responsive to CTX
Mitochondrial dysfunction presentation
Myopathy (muscle weakness, myalgia), nervous system dysfunction (neuropathy, seizures), lactic acidosis, ragged red fibers on biopsy
Dobutamine: MOA and effects
B-adrenergic agonist (primarily at B1 receptors, slight agonist at B2 receptors);
Positive inotropic effect, slight positive chronotropic effect
Adverse effects of foscarnet
Nephrotoxicity;
electrolyte imbalances (hypo- or hypercalcemia, hypo- or hyperphosphatemia, hypomagnesemia, hypokalemia);
Hypocalcemia and hypomagnesemia can lead to seizures
List the opioid analgesics
Morphine, fentanyl, codeine, loperamide, methadone, meperidine, dextromethorphan, diphenoxylate, pentazocine
Enteric bacteria produce what vitamins
Vitamine K and folate
Achondroplasia pathophys
Point mutation in FGFR3 (fibroblast growth factor receptor 3), causing overexpressiong of FGFR3, which inhibits chondrocyte proliferation and prevents endochondral ossification in the long bones
Microscopic findings in ALS
Loss of neurons in anterior horn (LMN lesion);
Degeneration and atrophy of lateral corticospinal tracts (UMN lesion);
Loss of neurons in motor nuclei of CN V, IX, X, XII
Clinical findings of tabes dorsalis
Sensory ataxia (wide-based gait, positive Romberg sign), lancinating pains, neurogenic urinary incontinence, Argyll Robertson pupils
Prinzmetal angina: definition, triggers, tx
Episodic, transient attacks of coronary vasospasm (at rest and at night), producing temporary transmural myocardial ischemia with ST- elevation;
Triggers include smoking, cocaine, dihyrdoergotamine/triptans
Tx: smoking/drug cessation, vasodilator therapy (nitrates, CCBs)
Immunological response responsible for Crohns Dz
Th1 cells (secrete IFN-g, IL-2, and TNF) causing intestinal damage; non-caseating granulomas
Location of AV node
Endocardial surface of the RA, near the insertion point of the leaflet of the triscuspid valve, near the opening of the coronary sinus
