STEP1 Flashcards
maternal/fetal hep B transmission
babies of HBeAg+ mothers have 90% chance of infection
infected babies are mostly asymptomatic b/c immune-tolerant (so immune cell doesn’t hurt infected liver cells), but have 90% chance of progression to chronic hep B; this can be prevented with hep B vaccine
pernicious anemia
pernicious anemia (vitamin B12 deficiency) is caused by autoimmune destruction of parietal cells, which live in the superficial gastric glands
hydroceles
hydroceles can be communicating, caused by incomplete obliteration of processus vaginalis, and this can also cause an indirect inguinal hernia
lab tests for osteoblasts and clasts
Osteoblast activity - bone-specific alkaline phosphatase
Osteoclast activity - 1) urinary deoxypyridinoline, 2) tartrate-resistant acid phosphatase and urinary hydroxyproline
TSS cause
TSS is due to toxic shock syndrome toxin from staph aureus. This is a superantigen which activates helper T cells and antigen-presenting cells (macrophages)
microbiology bile
Enterococci grow in bile and 6.5% NaCl
Strep viridans is bile-insoluble and pneumoniae is bile-soluble
enterococcal infection mostly after cystoscopy, colonoscopy, or OB procedures
Achalasia
Achalasia = motility disorder from decreased inhibitory ganglion cells in esophageal wall => normal contraction of UES but decreased peristalsis in mid esophagus and incomplete relaxation at LES => dysphagia, regurg, and chest pain
Barium swallow => bird’s beak sign
Gout tx
Acute: NSAIDS
Chronic: allopurinol (XO inhibitor), probenecit (uricosuric) etc.
how does food => insulin release?
glucose enters pancreatic beta cells via GLUT-2, then is metabolized to make ATP which binds K+ channels, causing them to close => membrane depolarization => v-gated Ca++ channel opening => increased intracellular Ca++ => insulin release
Filtration Fraction
Filtration Fraction = GFR/RPF (renal plasma flow)
mild efferent constriction => increased GFR and FF
severe efferent constriction => decreased GFR and increased FF
normal GFR = 125
action of fructose 2,6 bisphosphate
fructose 2,6-bisphosphate activates PFK-1, driving glycolysis and inhibiting gluconeogenesis
Pentose Phosphate Pathway
Pentose Phosphate Pathway makes NADPH (reductive power) and ribose-5-phosphate (nucleotide precursor)
irreversible oxidative steps and reversible nonoxidative steps
both make r-5-p, nonoxidative uses up excess r-5-p but kicks into reverse if need for r-6-p exceeds what oxidative can handle
oxidative makes NADPH and needs g-6-p deydrogenase
nonoxidative only makes r-5-p and need transketolase and transaldolase
Tumor Lysis Syndrome
chemo => cell death -> K, phosphorous, and uric acid release
uric acid precipitates in acid environments (eg: distal tubule and collecting ducts
tx: urine alkalinization, hydration, allopurinol
Traveler’s diarrhea cause
ETEC (E. coli) which makes heat labile (LT, cholera toxin-like) and heat stable (ST) toxins
LT => increased cAMP
ST => increased cGMP
DiGeorge Syndrome
CATCH 22 => no 3rd and 4th pharyngeal pouches => no thymus => no TCs => viral, fungal, and protozoal infections
Chediak-Higashi
AR trafficking deficit => no phagolysosones => pyogenic infections, neutropenia, granules in leukocytes, albinism, neuro defects (nystagmus), recurrent pyogenic staph and strep infections
e. Coli virulence factors + effects
LPS => bacteremia and septic shock
K1 capsular polysaccharide => neonatal meningitis
verotoxin (shiga-like toxin) => bloody diarrhea
heat-stable + -labile enterotoxins => watery diarrhea
P fimbriae => UTIs
adrenal cortex zones (out to in)
zona glomerulosa - mineralocorticoids (aldosterone)
zona fasciculata - glucocorticoids (cortisol)
zona reticularis - androgens
Cushing syndrome v. disease
Cushing syndrome = glucocorticoid excess
Cushing disease = Cushing syndrome caused by an ACTH-secreting pituitary adenoma, which => hyperplasia of zona fasciculata and reticularis
Post-operative urinary retention + tx
from decreased contractility of bladder detrusor muscle
treatment = Bethanechol (muscarinic agonist)
Incidence
incidence = new cases / population at risk
need to subtract out those already infected
Maple Syrup Urine Disease
failure to break down BRANCH(maple tree)ed- chain amino acids Leu, Ile, and Val 2/2 a mutation in BCKDComplex - may improve w/ high-dose thiamine treatment as this is a coenzyme required by BCKD
Bipolar treatment
lithium, valproate, quetiapine
hyperacusis
increased sound sensitivity, comes from stapedius muscle paralysis due to facial nerve injury
effects of AV shunt from tissue injury
AV shunt (fistula) => decreased resistance => increased preload (blood flow to heart) and decreased afterload (blood pressure) => increased peak volume (end-diastolic volume) and decreased peak pressure (afterload)
RBC storage
Whole and packed RBCs usually stored with citrate anticoagulant. this can chelate calcium and magnesium, which becomes a problem (hypocalcemia or hypomagnesemia) after 5-6 liters. RBCs can also lose intracellular potassium, which can cause hyperkalemia
1st and 2nd pharyngeal arch derivatives
1st pharyngeal arch: trigeminal n, mandible, maxilla, zygoma, incus, malleus
2nd pharyngeal arch: facian n, stpaes, styloid, lesser horn of hyoid
BC cytokines
CD19,20,21
TC cytokines
CD4(helper) or CD8 (cytotoxic)
Who expresses CD 15?
granulocytes and Reed-Sternberg cells (hodgkin lymphoma) express CD15
Who expresses CD16?
NK cells, neurophils, and macrophages express CD16
sepsis cytokines
TNF-alpha
IL-1 and IL-6 are involved too
cell that doesn’t use ketones
ketones are used by all cells with mitochondria, including brain (though it will be unhappy)
RBCs have no mitochondria
Vincristine MOA
inhibits MT formation by binding beta-tubulin - causes cytotoxicity during M phase (cell division) - side effects include neurotoxicity (peripheral neurophathy)
cell cycle phases + chemo agents at each stage
G1: prep for DNA synth
G0: resting
S: DNA replication (blocked by etoposide, irinotecan, MTX, 5-fluorouracil)
G2: error correction or apoptosis (bleomycin and doxorubicin act here)
M: cell division (vinca alkaloids and taxanes act here)
cell cycle nonspecific chemo agent
cyclophosohamide
effects of increased duodenal acidity on bile composition
increased duodenal H+ => secretin release from duodenal S-cells => bicarb secretion from pancreatic cells - K+ stays the same and Cl- decreases
hip muscles and actions
Flexion: iliopsoas, rectus femoris, tensor fascia lata
Extension: gluteus maximus, semitendinosus, semimemganosus, biceps femoris (long head)
Abduction: gluteus medius and minimus
Adduction: adductor brevis, longus, and magnus
iliopsoas components + attachments
psoas major +psoas minor + iliacus - go from pelvis/spine to femur
primary myelofibrosis pathophys
from megakaryocytic hyperplasia => fiberblast proliferation + collagen in bone marrow => pancytopenia over time and eventually => hepatosplemomegaly from compensatory extramedulaary hematopoiesis
primary myelofibrosis lab tests
teardrop-shaped and nucleated RBCs on smear
mutations causing myeloproliferative disorders
except for CMP, myeloprolifeative disorders (polycythemia vera, essential thrombocytosis, primary myelofibrosis) are caused by JAK2 mutation => increased activation of JAK/STAT pathway
CML is from BCR-ABL (9:22) fusion protein (Philadelphia chromosome)
Role of femoral n.
quad motion, patellar reflex, and sensation over anteromedial thigh and leg
collagen types
Be (So Totally) Cool, Read Books
I - Bone, Skin, Tendons, ligaments, corena, vessels, scars - mut => osteogenesis imperfecta (most common)
II - Cartilage, vitreous humor, nucleus pulposus
III - Reticulin, vessels, skin, lungs, guts, bone marrow, lymph, granulation tissue - mut => vascular Ehlers-Danlos
IV - Basement membranes - mut => Alport syndome
nec fasc causes in order
strep pyogenes (GAS), staph aureus, c. perfringens, polymicrobial
Group A Strep lab tests + virulence factors
Strep pyogenes is G+, coag-, catalase-, PYR+, B-hemolytic, and bacitracin-sensitive
virulence factors: hyaluroonidase, M protein, toxins O and S
acoustic neuroma
schwann cell tumor from vestibulocochlear nerve (cerebellopontine angle => unilateral sensorineural hearing loss
antiemetic categories and examples
antimuscarinis (anticholiergics) - scopolamine
antihistamines - diphehydramine, promethazine, meclizine
Dopa R antagonists - prochlorperazine, metoclopramide
5-HT R antagonists - ondansetron, granisetron
neurokinin 1 R antagonists - aprepitant, fosaprepitant
last 3 rows good for chemo-induces vom
vomiting pathophys
vomiting reflex mediated by M1, D2, H1, 5-HT, and NK1 receptors
Hardy-Weinberg
p + q = 1
p^2 + 2pq + q^2 = 1
square root of prevalence = mutant allele frequency
eukaryotic TSS
CAAT and TATA
Pellagra
niacin (B3) deficiency => photosensitive dermatitis, diarrhea, dementia
What enzymes is vit B3 a cofactor for
pyruvate dehydrogenase
malate dehydrogenase
isocitrate dehydrogenase
alpha-ketoglutarate dehydrogenase complex
how long after fertilization is hCG positive in serum and urine?
8 days; 14 days
elastase
elastases are proteases in alveolar fluid produced by alveolar macrophages and by neutrophils; if excess => centriacinal or panacinar emphysema
increased affinity of Hgb for O2
Hgb mutations causing increased O2 affinity (left shift) => decreased O2 release in tissues => kidney hypoxia => epo release => erythrocytosis
regulation of glycogenolysis in liver and muscle
glycogenolysis in muscle cells increases during contraction b/c increased Ca from contraction => phosphorylase kinase (PK) activation => glycogen phosphorylase activation => glycogenolysis
In liver, PK is activated through epi and glucagon binding to GPCRs=> increased cAMP => PKA activation => PK activation
Diabetes Insipidus
From decreased ADH production (central) or resistance (nephrogenic)
If respond to exogenous ADH, it’s central. ADH is made in the paraventricular and supraoptic nuclei of the hypothalamus and stored in the post. pituitary.
Damage to post. pit. only causes temporary DI, while hypothalamus damage is permanent.
Rifaximin
Rifaximin is an antibiotic used in hepatic encephalopathy to decrease intestinal production and absorption of ammonia.
Lactulose
Used in hepatic encephalopathy to lower colonic pH and thus increase conversion of ammonia to ammonium.
Varenicline
Used in smoking cessation. Partial nAchR agonist which reduces withdrawal cravings and reduces the rewarding effects of nicotine.
alpha-1 antitrypsin deficiency
alpha-1 antitrypsin deficiency (AD) - made in liver, blocks proteolytic enzymes (like elastase)
deficinecy => increased tissue damage during inflammation => panacinar emphysema (worse with smoking)
also => intrahepatocyte accumulation of misfolded AAT => cirrhosis and HCC - on liver histology with periodic acid-Schiff see reddish-pink intracellular granules.
EHEC
Enterohemorrhagic e. Coli => bloody diarrhea - O157:H7 - makes Shiga-like toxin, which inactivate 60s ribosomal subunit
How long does depression have to last to qualify as Major Depressive Disorder?
> 2 weeks
RPGN immunofluorescence
RPGN => crescent formation (fibrin deposits) - IF shows these deposits
Langerhans giant cells
TB => caseating granuloma with Langerhans giant cells (not Langerhans cells) which are macrophages activated by CD4+ Th1 cells. They have multiple nuclei organized peripherally in a horseshoe shape
Stop codons
UAA, UAG, UGA
M pneumoniae
causes walking pneumonia: low-grade fever, malaise, chronic dry cough, CXR much worse than clinical appearance, need cholesterol to grow b/c only have cholesterol-rich cell membrane
Pharyngeal arch - Aortic arch - CN - key derivatives
1-1-Trigeminal (CN V) - maxillary artery
2-2-Facial (CN VII) - stapedial artery (regresses)
3-3- Glossopharyngeal (CN IX) - common carotid and proximal internal carotid arteries
4-4- Superior laryngeal branch of Vagus (CN X) - aortic arch, subclavian arteries
5-5-obliterated-obliterated
6-6-recurrent laryngeal branch of Vagus (CN X) - pulmonary arteries and ductus arteriosus
PSGN microscopy findings
2-4 wks post strep infection (skin or pharyngitis) => RBCs, proteinuria on UA
light microscopy: large, hypercellular glomeruli
IF: granualr deposits IgG, IgM, C3 along BM - lumpy bumpy
EM: IC depositions on epithelial side of BM
Digoxin
rate control in afib, slows AV node conduction via increased parasympathetic tone 2/2 sensitized arterial baroreceptors and increased efferent ganglionic transmission
statins and bile sequestrants
statins inhibit HMG CoA redutase, preventing hepatic cholesterol synth bile sequestrants (cholestyramine) bind bile acids in GI tract => increased synth of new bile acids, depletion of hepatic cholesterol, and increased HMG CoA reductase => increased hepatic cholesterol synth
ovulation trigger
LH surge
gonadotropin feedback in males
inhibin B from Sertoli cells inhibits FSH
testosterone from Leydig cells inhibits LH
TB granuloma formation
multinucleated giant cells and epitheliod macrophages develop due to Th1 cells release Inf-y, IL-12, and TNF-alpha
true and false diverticula
Meckel’s diverticulum: connects ileum to umbilicus; true diverticulum, so contains mucosa, submucosa, and smooth muscle
false diverticula (herniations through muscular layer) only have mucosa and submucosa
DRESS Sy
Drug Reaction with Eosinophilia and Systemic Symptoms - from anticonvulsants, allopurinol, sulfa, abx => fever, lymphadenopathy, facial edema, skin rash, hepato, renal, and pulmonary sx
Labs: eosinophilia, lymphocytosis, elevated ALT
Tx: remove drug
catecholamine synth
tyrosine -(tyrosine hydroxylase)-> DOPA -(dopa decarboxylase)-> Dopanime -(dopaine beta-hydroxylase)-> Norepinephrine -(PNMT)-> Epinephrine
last step is upregulated by Cortisol
protein A
Staph Aureus VF that’s part of cell wall, binds Fc portion of IgG Abs and prevents complement activation => decreased C3b and impaired opsonization and phagocytosis
mannitol toxicity and RFs
pulmonary edema - volume redistribution from tissues to plasma => increased hydrostatic pressure => leakage
RFs: CHF, hx of pulmonary edema
renal artery stenosis
occurs in elderly 2/2 atherosclerosis or women of childbearing age 2/2 fibromuscular displasia, => asymmetrical kidneys, pain after eating from ischemia, HTN, abdominal bruit
acute interstitial nephritis
from beta lactams, NSAIDs, sulfa, rifampin, and diuretics => type IV hypersensitivity (1-3 wks) => increased IgE, eosinophilia, eosinophiluria
Sx: fever, maculopaupular rash, acute renal fail, from renal interstitial edema, leukocyte inflammation
Ductal Carcinoma in Situ
pleomorphic cells with prominent central necrosis that don’t penetrate the BM; precursor to invasive ductal carcinoma (breast cancer)
alpha agonists
increase systolic and diastolic BP, via peripheral vasoconstriction => reflexive increased vagal tone => decreased HR, slowed AV node conduction
hand bones
lunate and scaphoid bones articulate with radius
straight line to pinky, here comes the thumb
scaphoid lunate triquetrum pisiform hamate capitate trapezoid trapezium
altitude
altitude => hypoxemia => hyperventilation => respiratory alkalosis (low PaCO2)
after a few days => chronic respiratory alkalosis and compensatory decreased serum bicarb (metabolic acidosis)
DNA binding protein examples
TFs (Myc, CREB), steroid Rs (cortisol, aldosterone, pregesterone), thyroid hormone R, fat-soluble vitamin Rs (vit D, retinoic acid), and DNA transcription and replication proteins
CN III palsy
ptosis, down and out gaze, fixed dilated pupil, loss of accommodation
strongyloides stercoralis
strongyloides stercoralis: roundworm filariform larvae penetrate skin, move to lungs via blood, get coughed up and swallowed, develop in intestine - eggs hatch to rhabditiform larvae which are pooped out
diagnose via rhabditiform larvae in stool
can cause autoinfection cycle => hyperinfection syndrome with multiorgan dysfcn and sepsis
tx = ivermectin
Acromegaly tests
Screen by checking for high IGF-1
Confirm with oral glucose tolerance test (hyperglycemia should suppress GH)
Hormones made in ant pit
Flat p(I)g FSH LH ACTH prolactin GH
Prolactinoma tx
Cabergaline
Bromocriptine
Don’t need surgery
Nonfunctional pituitary adenoma
Go find the adenoma GH FSH and LH TSH ACTH Lost in this order
herpetic gingivastomatitis
primary HSV-1 Tzank smear with multinucleated giant cells
mycoplasma pneumoniae lab
cold agglutination - Abs which are anti-RBC but only when cold, not at physiologic temp (cold agglutinins)
Other things that cause these are EBV and hematologic malignancies
Dengue
4 serotypes of Dengue virus - 2nd infection by a different serotypes => Abs worsen infection => Dengue hemorrhagic fever
Legionella RFs and labs
travel, nursing homes
hyponatremia, increased neutrophils
sporothrix schenckii
subcutateous mycosis from a thorn prick which spreads along lymphatics
congenital rubella
cataracts, sensorineural deabness, PDA
prevent by giving mom MMR vaccine weeks before delivery but some time after first few weeks gestation (live attenuated)
Aspergillus complications
can cause allergic bronchopulmonary aspergillosis (a type I hypersensitivity reaction) in people with asthma or CF; this leads to eosinophilia
influenza A superinfections
staph aureus, strep pneumoniae, haemophilus influenzae
cat scratch fever
bartonella hensleae - primary erythema and rash => lymphadenopathy
can also cause bacillary angiomatosis in immunocompromised people (red/purple vascular papules)
and culture-negative endocarditis
Th2 cell role
sensitized Th2 cells secrete IL-4 and IL-13, which drive BC class switching to IgE. They also make IL-5 (recruits eosinophils) and IL-10
candida immune response
purely TC-mediated (like PPD - type IV hypersensitivity)
opsonins
IgG, complement; IgM doesn’t opsonize but rather activates complement which does
Type III hypersensitivity
IC deposition which causes vasculitis and can use up complement (causing drop in blood levels)
n. meningitidis VF
LOS => shock; blood levels correlate with morbidity and mortality
strawberry tongue
scarlet fever
top causes of osteomyelitis
staph aureus and GAS, after bacteremia
scabies
rapidly spreading rash, more itchy at night, from hands up arms and torso
cryptococcus
CNS sx in HIV, non-enhancing lesions, positive latex agglutination test, budding yeast on india ink and light microscopy
obligate intracellular bacteria
Rickettsia, Chlamydia, Coxiella (need host ATP)
facultative intracellular bacteria
salmonella, neisseria, brucella, mycobacterium, listeria, francisella, legionella, yersinia pestis
parasite cause of biliary tract disease, cholangiocarcinoma
clonorchis sinensis
parasite cause of brain cysts, sz
taenia solium (neurocysticercosis)
parasite that causes hematuria, bladder SCC
schistosoma haematobium
parasite cause of liver cycsts
echinococcus granulosus (hydatid cyst)
parasite that causes microcytic anemia
ancylostoma, necator
parasite that causes myalgias and periorbital edema
trichinella spiralis
perianal pruritus
enterobius (tape test)
parasites that cause portal HTN
schistosoma mansoni and japonicum
parasite that causes vB12 deficiency
diphillobothrium latum (cobalamin)
B vitamin names
B1 - Thiamine - The B2 - Riboflavin - Responsible B3 - Niacin - Nutritionist B5 - Pantothenic acid - Puts B6 - Pyridoxine - Pineapple B7 - Biotin - Before B9 - Folate - Fried - least reserves B12 - Cobalamin - Chicken
DNA virus rules and exceptions
all ds except for parvovirus
all replicate in nucleus except for poxvirus
all icosahedral except for poxvirus
RNA virus rules and exceptions
all ss except for reoviruses
all replicate in cytoplasm except influenza (orthomyxovirus) and retroviruses
herpesvirus membrane origin
nuclear membrane (other enveloped viruses all cytoplasm)
reoviruses and main relevance
coltivirus - colorado tick fever
rotavirus - fatal diarrhea in kids
picornaviruses and main relevance
PERCH
Poliovirus - salk/sabin vaccines - IPV/OPV
Echovirus - aseptic meningitis
Rhinovirus - common cold
Coxsackievirus - aseptic meningitis, herpangina (mouth blisters, fever), hand/foot/mouth disease, myocarditis and peridarditis
Hepatitis A virus - acute hepatitis, smoking aversion
Hepevirus and main relevance
Hepatitis E virus
calicivirus and main relevance
norovirus - gastroenteritis
flaviviruses and main relevance
HCV, Yellow fever, Dengue, St. Louis encephalitis, West Nile (meningoencephalitis), Zika
togaviruses and main relevance
rubella, W and E equine encephalitis, Chikungunya virus
retroviruses and main relevance
HTLV - TC leukemia
HIV - AIDS
coronaviruses
SARS, MERS, common cold
orthomyxovirus
influenza virus
paramyxoviruses and main relevance
parainfluenza - croup
RSV - bronchiolitis in babies; tx = ribavirin
Measles (rubeola)
Mumps
rhabdovirus
rabies
filoviruses and main relevance
Ebola - rapidly fatal hemorrhagic fever
Margurg - same
arenaviruses and main relevance
LCMV - lymphocytic choriomeningitis virus
Lassa fever encephalitis - spread by rodents
bunyaviruses and main relevance
California encephalitis - arthropod borne
Sandfly/Rift Valley fever - arthropod borne
Crimean-Congo hemorrhagic fever - arthropod borne
Hantavirus - hemorrhagic fever, pneumonia - rodent poop
delta virus and main relevance
Hepatitis D virus - needs Hep B to replicate
aspergillus fumigatus manifestations
Invasive pulmonary aspergillosis - oportunistic infection in immunosuppressed and neutropenic pts
Aspergilloma - colonizing - fungus ball within preexisting lung cavity
Allergic bronchopulmonary aspergillosis - type I hypersensitivity reaction in pts with asthma or CF
c. diff treatment
Oral metronidazole or vancomycin
If recurrent, give fidaxomicin (RNA polymerase inhibitor)
Staph scalded skin syndrome
Widespread epidermal sloughing with gentle pressure (NIkolsky’s sign), plus fever, in infants and children; due to exfoliatin (exotoxin which cleaves desmoglein - basically a toxic pemphigus vulgaris) production by staph species; not usually fatal
lactose-fermenting G- rods
entereobacter cloacae, e. coli, klebsiella pneumoniae (pseudomonas aeruginosa does not ferment lactose)
all 4 cause UTIs in ppl with catheters
strep gallolyticus (formerly bovis) bacteremia
colon cancer eval
HSV-1 encephalitis
Most common cause of fatal sporadic encephalitis
Primary oropharyngeal infection -> brain via nose or reactivation of virus from trigeminal ganglion
Causes edema and hemorrhagic necrosis of the temporal lobe (uni- or bilateral)
Diseases associated with HLA B27
seronegative arthropathies: psoriatic arthritis, ankylosing spondylitis, IBD-associated arthritis, and reactive arthritis
Diseases associated with HLA DQ2/DQ8
celiac disease
Diseases associated with HLA DR2
MS, hay fever, SLE, Goodpasture syndrome
Diseases associated with HLA DR3
DM1, SLE, Graves, Hashimoto, Addison disease