uWorld 55 Flashcards
what do C3a and C5a do
both are anaphlatoxins (so is C4a)
C3a: recruits and activates EOSINOPHILS and BASOPHILS
C5a: recruits and activates NEUTROPHILS
what are specific neutrophil chemotactic agents
N-FORMYlATED PEPTIDES
leukotrienes B4
5-HETE (the leukotriene precursor)
C5a
what is NEPRILYSIN
a metalloproteiase that cleaves and inactivates endogenous peptides including NATRIURETIC PEPTIDES, GLUCAGON, OXYTOCIN, and BRADYKININ
inhibition of neprilysin leads to increased levels of ENDOGENOUS NATRIURETIC PEPTIDES, which promote beneficial effects in heart failure
how do you treat and adrenal crisis
hydroxycortisone or dexamethasone
HIGH-FLOW IV FLUIDS
aflatoxins cause what mutation
G:C to T:A mutation in codon 249 of the p53 gene leading to hepatocellular carcinoma
what do short non-coding RNA sequence (microRNA and small interfering RNA) do
induce post translational gene silencing by base-pairing with complementary sequences within target mRNA molecules
a double stranded RNA molecule that is complementary to a region of mRNA fucks up what
mRNA translation (posttranscriptional modification)
what is RNA interference
an important mechanism in which short (20-30bp) non-coding RNA sequence induce POSTTRANSCRIPTIONAL GENE SILENCING
types of silencing RNA include SMALL INTERFERING RNA (siRNA) and microRNA (miRNA)
after being transcribed, miRNA undergoes processing in the nucleus to form a DOUBLE-STRANDED precursor that is then exported into the cytoplasm
there, the precursor is clever into a short RNA helix by a ribonuclease protein called DICER
individual strands are then separated and incorporated into RNA-INDUCED SILENCING COMPLEX (RISC)
multi protein complex uses its associated miRNA was a template to bind to complementary sequences found on target mRNAs
exact match results in mRNA degradation, but a partial match also causes translational repression by preventing ribosome and transcription factor binding
whats the difference b/w brown and black pigment stones (gallbladder)
BLACK stones: CHRONIC HEMOLYSIS (sickle cell, spherocytosis) or increased ENTEROHEPATIC CYCLING of bilirubin (ILEAL disease)
BROWN stones: BILIARY TRACT INFECTION (E coli, liver fluke) which release of microbial beta-glucronidases
BOTH result in increased UNCONJUGATED BILIRUBIN leading to calcium-bilirubinate precipitation
what do the gluteus medius and minus do
stabilize hip
abduct the thigh when limb is extended
whats the obturator internus do
fan-shaped muscle originating from the medial surface of the obturator membrane, ischium, and pubic rim
exits pelvis through he lesser sciatic foramen and insets on the greater trochanter of the femur
externally rotate thigh when extended and abduct the thigh when flexed (same as piriformis)
what does the piriformis do
originates on anterior aspect of sacrum and occupies most of the space in the greater sciatic foramen
inserts on the greater trochanter of the femur
externally rates the thigh when etude and abduct the thigh when flexed
what structures run above the piriformis and under it in the greater sciatic foramen
above: SUPERIOR gluteal vessels and superior gluteal nerve
below: INFERIOR gluteal vessels, internal pudendal vessels, multiple nerves (SCIATIC)
what is piriformis syndrome
muscle injury or hypertrophy compression SCIATIC nerve to cause sciatica-lied symptoms (pain, tingling, and numbness in buttocks and along the nerve distribution)
muscle can be tender with deep palpation or on stretching with adduction and internal rotation
conditions that cause GI irritation (infection, chemo, distention) causing EMESIS should be treated how
5-HT3 receptor antagonists (ondansetron)
the GI irritation results in increased mucosal SEROTONIN relate and activation of 5-HT3 receptor on vagal and spinal afferent nerves
what is pharyngoconjucntival fever
ACUTE onset FEVER, COUGH, CONGESTION, PHARYNGITIS, and OCNJUCTIVITIS
ADENOVIRUS
dsDNA virus (NAKED)
localized back pain, low-grade fever, recent staph bacteremia suggests what
VERTEBRAL OSTEOMYLITIS
hematogenous spread (skin or soft tissues, IV cath), direct invasions form trauma or local spinal procedures, or direct spread from adjacent soft tissue infection
BLOOD CULTURES and MRI of SPINE
what causes digital clubbing
prolonged hypoxia
lung cancer, TB, cystic fibrosis, suppurative lung disease (emphysema, bronchiectasis, and chronic lung abscesses)
cyanotic congenital heart disease (5Ts- especially tetralogy of fallot) and bacterial endocarditis
IBD, hyperthyroidism, and malabsorption
what does an S3 heart sound in an adult suggest
suggests VENTRICULAR ENLARGEMENT
chronic severe mitral regurg, chronic aortic regurg, heart failure associated with dilated or ischemic cardiomyopathy
heard during DIASTOLE, shortly after S2
heard with bell at APEX while patient is in the left lateral ducbitous position at END EXPIRATION
what does amyl nitrite inhalation do
causes VASODILATION, decrease in venous return and blood pressure
decreases intensity of S3 (so does furosemide and valsalva)
lower extremity cyanosis and clubbing in a 10 year old WITHOUT pulse difference in extremities suggests what
PATENT DUCTUS ARTERIOSUS complicated by Eisenmenger syndrome
(coarctation has pulse differences in upper and lower body)
what kind of hypersensitivities are seen in SLE
Type II: antibodies against blood cells (PANCYTOPENIA)
Type III: LUPUS NEPHRITIS- immune complex deposition causing PROTEINURIA and RBC CASTS
what does primaquine do in malaria treatment
kills HYPNOZOITES (the LATENT HEPATIC infection) that are caused by P VIVAX and OVALE
what is the most serious long term effect of chloroquine use
RETINOPATHY
