MSK/Derm (U.W.) Flashcards
Leukocyte Adhesion Deficiency
s(x)- recurrent infections, especially S. aureus, without purulence
- might notice CD18 missing from leukocyte surfaces. causes no integrin formation, so leukocyte can’t migrate causing leukocytosis
what connects osteocytes?
- gap junctions
- allows osteocytes to communicate with bone surface and regulate bony remodeling
eczema dermatitis treatment with corticosteroid causes what side effect
dermal atrophy due to decrease production of ECM and GAGs
what can augment azathioprine’s action?
ALLOPURINOL
azathioprine can be inactivated by Xanthine Oxidase. Xanthine Oxidase inhibitor Allopurinol can therefore increase Azathioprine being converted to ACTIVE metabolites, by blocking the inactivating pathway
Pirimformis Syndrome
Piriformis M goes through greater sciatic foramen, inferiorly in the greater sciatic foramen, the sciatic n also passes.
s(x)- pain on buttock and posterior thigh
pain upon external rotation of extended thigh and abduction of flexed thigh
mosaic pattern with prominent cement lines accompanied by bony pain is what disease?
Paget’s
thymus is derived from what? what other structure has the same derivative?
3rd pharyngeal pouch
inferior parathyroid glands
where do you give an intragluteal injection
anterolateral preferred, if not, then superolateral
injection in which quadrant affects the superior gluteal N
superomedial
injection in which quadrant affects the sciatic N
superomedial, inferomedial and lateral
blood supply to femoral head
medial circumflex A
Falling onto an outstretched arm, aka hyperextension injury often causes what?
supracondylar fracture
anterolateral displacement of supracondylar fracture injures?
radial N
anteromedial displacement of supracondylar fracture injures?
median N and brachial A
what type of HS response in MG
Type II- antibody mediated
Osgood Schattler Disease
Repeated quads contraction and growth spurt can cause patellar tendon to separate from TIBIAL TUBERCLE causing a secondary ossification center and focal pain there, with pain on extension
Nursemaid’s Elbow
Radial head subluxation (aka no longer interacting at elbow joint) bc of pulling force on arm causing annular ligament to be displaced/torn.
*hints- child< 5yo, holds arm tightly to body, refuses to flex elbow
most common cause of axillary N injury
anterior shoulder displacement
patellar fracture causes what movement problem
knee extension
what artery runs with the Radial N
Deep Brachial A
what artery runs with the Axillary N
PCHA
empty can test (abduct arm 90 degree, flex 30 deg, thumbs to the floor, resistance from above arm) tests integrity of what muscle
suprapinatus
Xeroderma Pigmentosa
Autorecessive mut in nucleotide excision repair, usually due to endonuclease defect
Chediak Higashi
oculocutaneous albinism + immunodeficiency + neuro symptoms ( nystagmus/ CN defects)
- defect in neutrophil phagosome lysosome function
- findings: giant lysosomal inclusions
what is the pathophysiology of scurvy
vit C deficiency
Vit C needed for post translation modification of collagen occuring at RER , specifically hydroxylation of proline and lysine residues that contribute to strength
Alkaptonuria?
- cause
- symptoms
- findings
- autosomal recessive deficiency in homogentisic acid dioxygenase (step in tyrosine metabolism) causes a build up of homogentisic acid, which accumulates in connective tissue/bone
- blue/black spots in sclera and auricular cartilage; arthritis in spine/joints, black urine
what does ATP binding to myosin cause
detachment of myosin head from actin filament (note this is NOT the power stroke!!)
appropriate way to start treatment for Rheumatoid Arthritis?
- induction with glucocorticoid (prednisone) or NSAID
- also start DMARDs (MTX, sulfasalazine tnfa) but these take weeks to kick in
t(x) for dermatophytosis ?
Terbinafine- blocks squalene epoxidasethereby inhibiting ergosterol synthesis
ecthyma gagrenosum
pseudomonas aeruginosa
Thoracic Outlet Syndrome
Ulnar impingement/lower plexus symptoms (pinky is tingly/numb) + pain/ parasthesia/edema due to subclavian A/V and brachial plexus impingement
**hint: often an extra RIB is mentioned
hint- often due to overhead injury like pitching
leukocytoclastic vasculitis
non-blanching palpable purpura on lower extremities following drug interaction (penicllin, cephalosporins)
cause: cutaneous small vessel vasculitis
Polyarteritis Nodosa
segmental, transmural inflammation of artery wall
- often causes GI ischemia, and ischemia of other organs- excluding lungs
idiopathic, but STRONG RELATION TO HEP B
antibodies against desmosomes
pemphigus vulgaris
antibodies against hemidesmosomes
bullous pemphigoid
graft v host disease
seen in tissue donations that has high concentration of lymphocytes (Liver, bone marrow).
Tcell of the graft attack host MHC antigens
pellagra
vit B3 (niacin) deficiency 3D's: diarrhea, dementia, dermatitis - without NAD, isocitrate dehydrogenase, malate dehydrogenase, and alphaketoglutarate dehydrogenase will not function
Giant Cell Arteritis is mediated by?
cytokines, specifically IL6
grotton papule
dermatomyositis
Ehlers Danlos
defect in Procollagen Peptidase.
Procollagen peptidase cleaves procollaged N and C terminals to make tropocollogen (in ECM)
if these N and C terminals are not cleaved, the procollagen remains SOLUBLE and is not able to crosslink
what type of sweat gland is involved in acne vulgaris
sebaceous sweat glands, which are holocrine sweat glands
osteogenica imperfecta
autosomal dominant mutation is type 1 collagen (found in osteoid)
poison ivy pathophysiology
urushiol is the toxin, it conjugates with hapten (a peptide). once presented on MHCI and II cells it elicits hapten sensitive T cells to proliferate.
CD8+ T cells then kill all keratinocytes expressing hapten causing the blistering
initial testing for GCA suspicion
ESR and CRP .. then temporal artery biopsy to confirm
Dermatitis Herpetiform pathophys and association
- self reactive IgA against gliadin crossreacts with epidermal gliadin
- assn- Celiac’s
action of latissimus dorsi
extension, adduction, and internal rotation of arm
why is raloxifene better than tamoxifen for osteoporosis
tamoxifen can cause estrogen agonist effects on the uterus causing endometrial hyperplasia/cancer
where as raloxifene has estrogen antagonist activity on the uterus
clinical use of calcipotriene, calcitriol, and tacalcitol ?
psoriasis
Vit D analogs inhibit keratinocyte proliferation and stimulate keratinocyte differentiation
remember vitamin D is a nuclear transcription factor
McCune Albright Syndrome clinical symptoms
large cafe au lait spots, fibrous dysplasia (osteolytic bone lesions), and endocrine abnormalities(like puberty before 7) = Mccune albright
McCune Albright pathogenesis
somatic mosaicism causing mutation in GNAS gene–> constitutively active alpha subunit of Gprotein/adenylate cyclase/CAMP
acute rheumatic fever cause of death
pancarditis
mode of diagnosing osteomyelitis
blood cultures
MRI of spine-most sensitive
dystrophin role
- linker protein that makes sarcolemma stable
- connects cytoskeleton (actin) to transmembrane proteins
Muscular Dystrophy- duchenne and becker
Xlinked recessive myopathy due to frameshift deletion of dystrophin
-gower’s sign
- muscle filled with fat (psuedohypertrophy)
(note becker’s MD is similar but is not a frameshift deletion, just a frameshift truncation, so less severe)
Stewart-Treves Syndrome
cutaneous angiosarcoma (a misnomer because it is a sarcoma of lymph).usually following a lymphnode dissection.
where does osteomyelitis affect children?
-METAPHYSIS of long bone because slower moving blood and fenestration is ideal for infection
