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HY Musc/Derm extras
Day 8
Question | Answer |
---|---|
What drug can be used in place of long term aspirin therapy in patients who have an asthmatic reaction to aspirin? | Clopidogrel |
Name the 4 main NSAIDs. | Ibuprofen, naproxen, indomethacin, and ketorolac. |
Which anti-inflammatory drugs should not be used in a patient with sulfa allergies? | COX-2 inhibitors (e.g., celecoxib) |
What is the difference between the mechanism of action of aspirin and that of acetaminophen? | Aspirin irreversibly inhibits cyclooxygenase while acetaminophen reversibly inhibits it. |
Which of the following properties does acetaminophen lack: antipyretic, analgesic, anti-inflammatory? | Anti-inflammatory |
What antidote can also be used to prevent contrast-induced nephropathy and as a mucolytic (breaks down mucus plugs) when inhaled? | N-acetylcysteine (used in acetaminophen toxicity) |
Which class of drugs inhibits osteoclastic activity and reduces both the formation and reabsorption of hydroxyapatite? | Bisphosphonates (all end in -dronate: etidronate, pamidronate, alendronate, risedronate, zoledronate) |
Why do bisphosphonates require the patient to remain in an upright position for several hours after taking the drug? Which bisphosphonate is an exception to this rule? | B/c they can cause corrosive esophagitis. Zoledronate does not cause this side effect. |
Which class of drugs should never be given to gout patients? | Salicylates; only very high doses will clear uric acid, and only minimally; low to medium doses will actually decrease uric acid clearance |
What test should be given before starting a patient on a TNF-alpha inhibitor (etanercept, infliximab, adalimumab)? | TB test (e.g., PPD skin test); drugs like infliximab predispose to reactivation of latent TB due to decreased macrophage function |
What is the difference between the composition of etanercept and infliximab and adalimumab? | EtanerCEPT is a reCEPTor that binds TNF. InfliximAB and adalimumAB are anti-TNF AntiBodies (AB) |
What are the layers of the epidermis from base to surface? | stratum Basalis, stratum Spinosum, stratum Granulosum, stratum Lucidum, stratum Corneum (Betty Sue's Grandma Loves Cupcakes) |
How are the epidermal layers altered in psoriasis? | Stratum Granulosum is decreased and Stratum Spinosum is increased |
How does the epidermis receive nutrients? | Via diffusion (no blood vessels in the epidermis) |
"Tight junction" that prevents diffusion across paracellular space | Zona occludens |
Name 2 proteins that compose the zona occludens (tight junction). | Claudins and occludins (occludins occlude stuff from moving across the paracellular space) |
"Intermediate junction" that surrounds the perimeter just below the zona occludens (tight junction) | Zona adherens |
What two proteins make up the zona adherens (intermediate junction)? | Cadherins connecting to actin (CADherins are Calcium dependent ADhesion molecules) |
"Desmosome" that acts as a small, discrete site of attachment | Macula adherens |
What two proteins are involved in the macula adherens (desmosome)? | Cadherins attaching to intermediate filaments (keratin, desmoplakin) |
Antibodies against the macula adherens are seen in which disease? | Pemphigus vulgaris (macula adherens=desmosomes) |
Allows adjacent cells to communicate for electric and metabolic functions (e.g., cardiac cells) | Gap junctions |
What proteins are involved in gap junctions? | Connexons (with central channel) |
What protein maintains the integrity of the basement membrane? What does it bind to? | Integrin; binds to laminin in the BM |
Connects cells to underlying EC matrix | Hemidesmosome |
Which disease involves antibodies against hemidesmosomes? | Bullous pemphigoid |
What sign indicates tearing of the ACL? | Positive drawer sign |
What sign indicates a torn MCL (medial collateral ligament)? | Abnormal passive abduction |
What is the unhappy triad of the knee? | 1. Medial collateral ligament (MCL) 2. Anterior cruciate ligament (ACL) 3. Lateral (or medial) meniscus |
Which landmark is used for a pudendal n block? | Ischial spine (pudendal n block aka saddle n block is used to relieve pain in childbirth) |
Which landmark is used to do a lumbar puncture? | Iliac crest (for spinal tap, cord ends at L1/L2, so keep needle between L3-L5) |
Which rotator cuff m is most commonly injured? | Supraspinatus |
Which rotator cuff m is injured in a pitching injury? | Infraspinatus (laterally rotates the arm) |
At what site does rotator cuff impingement typically occur? During what type of actions is it injured? What test is used to diagnose? | Occurs at the acromion with repetitive overhead actions (swimming, tennis serves), and is dx with empty can test (+ if patient finds it painful to abduct arm 15 degrees with thumb turned down) |
What is the other name for a lateral epicondylitis? | Tennis elbow (laTEral=TEnnis) |
What is the other name for a medial epicondylitis? | Golf elbow |
Lack of which structure in the m fiber may lead to uncoordinated contraction of individual fibers? | T tubules (depolarization travels along m cell and down the T tubule) |
Which m cell receptors mediate calcium-induced calcium release? | Ryanodine receptors (mutated in malignant hyperthermia) |
How do osteocytes communicate? | Via gap junctions |
Garnder on knees all the time. What type of injury will he have? | Pre-patellar bursa |
During m contraction, which band always remains the same length? | A band (A is Always the same, while H and I bands shrink) |
At which m receptor do CCBs like nifedipine act? | Dihydropyridine receptors (first step in calcium-induced calcium release prior to ryanodine receptors) |
At which m receptor does dantrolene have an inhibitor effect? | Ryanodine receptors (used to treat malignant hyperthermia) |
Slow twitch, red fibers, increased mitochondria and myoglobin concentration (increased oxidative phosphorylation)--> sustained contraction | Type 1 muscle (1 slow, red ox) |
Fast twitch; white fibers due to decreased mitochondria and myoglobin concentration (increased anaerobic glycolysis) | Type 2 muscle |
Which muscle type is predominantly seen in postural skeletal m (mm of spine and soleus m of the calf)? | Type 1 |
Which muscle type becomes hypertrophied during weight training (eg., lats, biceps, deltoids)? | Type 2 |
What causes the myosin head to detach from the actin filament? | ATP binding |
Lack of ATP for the skeletal and cardiac m contraction cycle leads to what finding? | Rigor mortis |
What causes the conformational change that moves tropomysoin out of the way so actin/myosin cycling can occur? | Ca binding to troponin |
Release of what two substances generates the power stroke? | Release of ADP and inorganic phosphate (Pi) |
Name 4 drugs/classes that inhibit myosin light chain kinase (MLCK) to prevent contraction of sm m. | 1. NO 2. Dihydropyridine CCB (nifedipine) 3. Epinephrine (@ B2 receptors) 4. Prostaglandin E2 |
Name 3 drugs/classes/substances that stimualte myosin lgiht chain phosphatase to promote sm m relaxation. | 1. Sildenafil 2. NO 3. LPS of gram neg organisms |
Which myosin light chain leads to sm m relaxation? | Myosin light chain phosphatase (myosin + actin) |
Which myosin light chain leads to sm m contraction? | Myosin light chain kinase (MLCK) (myosin P + actin-->cross-bridge formation) |
Where do osteoblasts come from (hint: it's not, "when a man and a woman really love each other...")? | Msenechymal stem cells in the periosteum KNOW THIS FOR SURE! |
Woven bone formed directly without cartilage; later remodeled to lamellar bone | Membranous ossification (flat bone growth in the skill, facial bones, and axial skeleton) |
What is the most reliable indicator of osteoblast activity? | Bone-specific alkaline phosphatase (osteoblasts release it) |
Give 3 reliable indicators of osteoclast activity. | 1. TRAP 2. Urinary hydroxyproline 3. Urinary deoxypyridinoline (most reliable of the 3) |
What are the chances of one normal parent and one parent with achondroplasia having a child with the disease? | AD: 50% chance of disease, 50% chance of normal |
What are the chances that two parents with achondroplasia will have the disease? | AD: 50% chance of disease, 25% chance of carrier, 25% chance of spontaneous abortion (homozygous for mutation) |
What gene is responsible for limb lengthening? | FGF gene |
What is the genetic abnormality underlying achondroplasia? | Constitutive activation of fibroblast growth factor receptor 3 (FGFR3) which inhibits chondrocyte proliferation |
Do patients with achondroplasia have problems with infertility? | Generally no problems with fertility; do need to deliver via C-section b/c of narrow pelvic outlet |
What diuretics are useful in women with osteoporosis? | Thiazides (decrease urinary calcium excretion and may improve bone density) |
Which diuretics are contraindicated in women with porous bones? | Furosemide (loops lose calcium!) |
What are the risk factors for osteoporosis? | Older age, smoking, corticosteroids, white, thin, no weight bearing exercise (step up, you!), poor calcium and vit D, hypogonadism, heparin |
How are mild cases of osteoporosis treated? | Estrogen (SERMS) adn/or calcitonin (builds bone) |
Why are severe cases of osteoporosis treated with pulsatile rather than continuous PTH? | Continuous PTH will pull calcium out of your bones! |
How is osteoporosis diagnosed? | Dexa bone density scan of lumbar spine or femur |
What is the mechanism of action of the drug of choice in severe osteoporosis cases? | Bisphosphonates (-dronates): inhibit osteoclast activity; reduce both formation and resorption of hydroxyapatite (bone mineral complex) |
What type of factor is responsible for 75% of the peak bone mass differences among individuals? | Genetic factors |
What are the two most important factors for osteoclast differentiation? What produces them? | RANK-L and M-CSF; osteoblasts make these factors |
What is the triad of osteopetrosis? | 1. Anemia 2. Thrombocytopenia 3. Infection Basically pancytopenia |
What X-ray finding is seen in osteopetrosis? | Erlenmeyer flask bones that flare out (may cause cranial n impingement due to narrowed foramina) |
What digestive disorder can lead to osteomalacia/rickets? | Cholestasis, or anything that causes malabsorption of fat soluble vitamins (ADEK). |
How does PTH affect phosphate, alkaline phosphatase, and calcium levels in the serum? | Increases calcium and alk phos (generally), and decreases phosphate (PTH is the Phosphate Trasher Hormone) |
What virus is suspected to be involved in Paget's disease of the bone? | Paramyxovirus |
Increased hat size and hearing loss due to narrowed auditory foramen | Paget's disease of bone (most patients are asymptomatic though) |
Mosaic bone pattern with long bone chalk stick fractures | Paget's disease of bone |
Paget's disease can lead to what cardiac and oncogenic complications? | Increase blood flow from increased arteriovenous shunts may cause high-output heart failure; can lead to osteosarcoma |
What is the treatment for Paget's? | Bisphosphonates (-dronates) to inhibit osteoclasts (the primary problem in Paget's is overactive osteoclasts) |
Besides Paget's, what other disease may lead to hearing loss due to narrowing of the auditory foramen? | Osteopetrosis |
Cafe-au-lait/Coast of Maine spots, unilateral bone lesions, and precocious puberty | McCune Albright syndrome |
How are calcium, phosphate, and PTH serum levels affected in renal insufficiency? | Serum calcium is decreased (primary problem), phosphate is increased (diseased kidney is unable to excrete it), and PTH is increased (compensatory mech for loss of calcium) |
Colon polyps (can cause colorectal cancer), lipomas, and osteoma (benign bone tumors) | Gardner's syndrome (FAP): Gardner's grow lumps and bumps everywhere |
Familial retinoblastoma predisposes to which malignant bone tumor? | Osteosarcoma (also Paget's, bone infarcts, and radiation) |
Anaplastic small blue cell malignant tumor of bone that is extremely aggressive, but responsive to chemo. May have Homer-Wright rosettes. | Ewing's sarcoma (11;22) |
Expansile, glistening mass within the medullary cavity of older individuals; malignant | Chondrosarcoma |
What are the predisposing factors for osteoarthritis? | Age, obesity, joint deformity |
Which arthritis is non-inflammatory and has no systemic symptoms? | Osteoarthritis |
What is the treatment for osteoarthritis? | Acetaminophen, NSAIDs and COX-2i, inject joint w/steroids, inject hyaluronic acid into joints, opioids, joint replacement |
What type hypersensitivity is rheumatoid arthritis? | Type 3 |
Baker's cysts (behind the knee) | Rheumatoid arthritis |
What is rheumatoid factor? | IgM antibodies against IgG |
Which antibody is less sensitive than rheumatoid factor but more specific? | anti-CCP antibody |
What is the treatment for rheumatoid arthritis? | NSAIDs and anti-TNF agents (entercept, infliximab, and adalimumab) |
Which syndrome associated with an increased risk of dental carries is associated with rheumatoid arthritis? | Sjogren's syndrome |
Which virus can present with symmetric arthritis that mimics RA in adults, but resolves spontaneously? | Parvovirus (causes slapped cheek/Fifth's disease in children) |
Groin pain exacerbated by weight bearing; assoc'd with sickle cell disease, SLE, high dose steroid therapy, and alcoholism. | Avascular necrosis of the femoral head |
Type 1 collagen defect that causes problems with bone matrix formation | Osteogenesis Imperfecta (I=1) |
Dactylitis in young child | Sickle cell disease (painful swelling of hands and feet during a vaso-occlusive crisis) |
Beading on chest felt by palpation, bowed legs | Vit D deficiency (rickets in children; problem with osteoid matrix accumulation around trabecula) |
Lesch-Nyhan syndrome is associated with which joint disease? | Gout |
Which diuretics may precipitate gout? | Thizaide and loop diuretics (decrease excretion of uric acid) |
Which biochemical disease affecting the liver may lead to gout? | von Gierke's disease |
Yellow crystals under parallel light | Gout |
What is the MC location for tophus formation in gout? | The external ear (also olecranon bursa or Achilles tendon) |
Why does alcohol consumption precipitate gouty attacks? | B/c alcohol metabolites compete for the same excretion sites in kidney as uric acid, causing decreased uric acid secretion and subsequent buildup in blood |
Hot, swollen knee in a young, sexually active person (monoarticular, migratory arthritis with asymmetrical pattern) | Neisseria gonorrhea; dx with joint aspirate |
What are the MCC of chronic infectious arthritis? | TB (from mycobacterial dissemination) and Lyme disease |
Dactylitis (sausage fingers), pencil in cup deformity on x-ray | Psoriatic arthritis |
Patient who gets up early in morning and runs 5 miles to allow for functioning throughout the day (suffers from fusion of joints in the spine) | Ankylosing spondylitis |
Ankylosing spondylitis predisposes patients for what cardiac and pulmonary abnormalities? | Aortic regurg and pulmonary fibrosis or restrictive lung disease; may also limit chest expansion |
Arthritis after a diarrheal illness | Inflammatory bowel disease assoc'd seronegative spondyloarthropathy (HLA-B27) |
What is Reiter's triad? | 1. Conjuctivities and anterior uveitis 2. Urethritis 3. Arthritis Seen post-GI or chlamydia infections |
What organism can cause arthritis seen in Reiter's triad? | Shigella flexneri |
What is the treatment for seronegative spnodyloarthropathies? | NSAIDs, steroids, and anti-TNF agents (main tx) |
What is the treatment for SLE (4)? | 1. Glucocorticoids 2. NSAIDs 3. Hydroxychloroquine 4. Cyclophosphamide |
What lab test is specific for the renal disease of lupus? | Anti-dsDNA antibodies |
What is causes CD8 T cell injury to myofibers in polymyositis? | Overexpression of MHC Class I proteins on the sarcolemma |
Malar rash, heliotrope (eyelid) rash, "shawl and face" rash, Gottron's papules (on knuckles), and mechanic's hands. Increased risk of malignancy. | Dermatomyositis |
MC NMJ disorder | Myasthenia Gravis |
Myasthenia gravis is associated with which tumor? | Thymoma |
How can an edrophonium test be used to distinguish between under and over dosing of AChE inhibitors in myasthenia gravis treatment? | No response w/administration= cholinergic crisis-over treatement; discontinue use of AChE inhibitor. Improvement w/administration= myasthenia crisis= undertreatment; increase does of AChE inhibitors |
Which NMJ disease presents with weakness that improves with use? | Lambert-Eaton syndrome |
Which NMJ disease is assoc'd with paraneoplastic diseases (small cell lung cancer)? | Lambert-Eaton syndrome |
What test is used to diagnose Lambert-Eaton? | Isometric contraction test (examiner exerts force on limb to see if strength improves) |
Which NMJ disease presents with dry mouth, impotence, hyporeflexia, and weakness that improves throughout the day? | Lambert-Eaton syndrome |
Which bulking disease presents with puffy, taut skin with absence of wrinkles? | Scleroderma (progressive systemic sclerosis); 2 types: diffuse scleroderma (anti-Scl-70 Ab/anti-topoisomerase I Ab) and CREST (anti-centromere Ab) |
Which scleroderma (PSS) type has a more benign course with less visceral involvement and a slower progression? | CREST |
Which epidermal layer is increased in hyperkeratosis? | Stratum corneum (seen in psoriasis) |
Which epidermal layer shows hyperplasia in acanthosis? | Sratum spinosum (seen with acanthosis nigricans) |
Which dermatologic finding presents as hyperkeratosis with rention of nuclei in stratum corneum? | Parakeratosis |
Which dermatologic finding presents as separation of epidermal cells (seen in pemphigus vulgaris)? | Acantholysis |
How are lipomas treated? | with excision (benign) |
What is the MCC soft tissue tumor of childhood? From where does it arise? | Rhabdomyosarcoma; arises from skeletal m in head and neck region |
Epidermal hyperplasia, hyperkeratosis, and koilocytosis | Warts; verruca vulgaris on hands and condyloma acuminatum on genitals (caused by HPV) |
1 year old infant with h/o mild asthma who is bathed daily presents with puritic eruption on skin flexures. | Atopic dermatiis (excema) |
What type of hypersensitivity is allergic contact dermatitis? | Type 4 |
Silver, parakeratotic scaling, Auspitz sign (bleeding when scale is scratched off) | Psoriasis |
What is the sign of Leser-Trelat? | Sudden appearance of multiple seborrheic keratoses indicating an underlying malignancy (e.g., GI, lymphoid); not a pre-malignancy though |
Young people get moles, old people get _________. | Seborrheic keratoses (SKs) |
Normal melanocyte # with decreased melanin production due to decreased activity of tyrosinase; may be caused by failure of neural crest cell migration during development | Albinism |
Irregular areas of complete depigmentation caused by a decrease in the number of melanocytes | Vitiligo |
Crepitus from methane and CO2 production | Necrotizing fasciitis |
Keratinocytes in which skin layer are destroyed by the exotoxin in Staphylococcal scaled skin syndrome? | Stratum granulosum only |
Positive Nikolsky's sign (separation of epidermis upon manual stroking of skin) | Pemphigus vulgaris (don't confuse with Auspitz's sign of psoriasis where the silverly scale bleeds when scraped off); Bullous pemphigoid has a negative Nikolsky's sign |
Immunoflourescence reveals net-like or reticular pattern | Pemphigus vulgaris (Vulgar=common; COMMONers wear hair NETS and work in DESperate conditions= vulgaris has NET like pattern and antibodies against DESmosomes) |
Deposits of IgA at the tips of dermal papillae | Dermatitis herpetiformis; assoc'd with Celiac disease |
>30% of body surface area sloughing off and detaching; may be caused by seizure meds, sulfa drugs, -cillins, and allopurinol | TEN |
Derm disorder assoc'd with hepatitis C | Lichen planus (purple, pruritic, polygonal papules) |
Cutaneous horn. Tx? | Actinic keratosis; tx= 5-Fu |
Hyperplasia of the stratum spinosum assoc'd with hyperinsulinemia (e.g., from Cushing's disease, diabetes) and visceral malignancy (>40yo) | Acanthosis nigricans |
Herald patch followed days later by a "Christmas tree" distribution | Pityriasis rosea |
Skin cancer that is locally invasive, rarely mets, has keratin pearls, and has an "eaten away" appearance | SCC |
Locally invasive but never metastasizes; rolled, pearly borders with central ulceration commonly with telangiectasias | BCC |
S100 + skin cancer with significant risk of metastasis. Dysplastic nevus is precursor lesion. | Melanoma |
ABCDs of melanoma | Asymmetry Border irregularity Color Diameter |
What feature of a melanoma correlates with its risk of metastasis? | Depth (Breslow's depth); do NOT shave off otherwise you won't know the true depth; do punch biopsy instead |
Variant of SCC that grows rapidly (4-6 weeks) and regresses spontaneously (4-8 weeks) | Keratoacanthoma |
What is the precursor lesion for SCC? | Actinic keratosis |