Step Review 2: Musculo, Respiratory, Renal, Hem Onc Flashcards
Which parts of the femur do the ACL and PCL originate from?
ACL: lateral condyle
PCL: medial condyle
What is the unhappy triad? Why is it slightly misleading?
ACL, MCL and medial meniscus tear. The lateral meniscus is more commonly injured
What bursa gets inflamed from excessive kneeling?
Prepatellar bursa (e.g. tile layer)
What bursa does a Baker cyst involve?
Gastrocnemius/semimembranosus bursa
Name the rotator cuff muscles and their innervations
Supraspinatus: suprascapular nerve
Infraspinatus: suprascapular nerve
teres minor: axillary nerve
Subscapularis: upper and lower subscapular nerves
Which is closer to the thumb: scaphoid or trapezium?
Trapezium
Between the trapezium, trapezoid, and triquetrum, which is in the proximal layer of wrist bones and which in the distal layer is most lateral?
Triquetrum is proximal (“try), trapezium is more lateral (thumb side)
Dislocation of which wrist bone may cause carpal tunnel syndrome? What might cause bilateral carpal tunnel?
Lunate, dialysis-related amyloidosis
Is sensation compromised in carpal tunnel?
No, the palmar cutaneous branch enters the hand external to the carpal tunnel.
Which ligament is cut to relieve carpal tunnel syndrome?
Transverse carpal ligament
What nerve does sensation over the lateral arm? Lateral forearm?
Lateral arm= axillary
Lateral forearm= musculocutaneous
What specific branch of the median nerve supplies the thumb?
The recurrent branch
What nerve supplies sensation to the posterior, medial hand?
Ulnar nerve, radial only does the radial side (e.g. opposite of median)
On the posterior hand, does the radial or median nerve do the tips of the thumb side fingers?
Median
Which nerve causes a winged scapula?
Long thoracic nerve (C5-C7)
What is klumpke palsy? How does an adult get it typically?
Total claw hand due to traction/tear of lower trunk of brachial plexus. Typically grabbing a tree branch on the way by or something similar
What is the action of lumbricals?
Extend DIP, PIP and flex MCP
What is compressed in thoracic outlet syndrome? Where?
Lower trunk of brachial plexus and subclavian vessels (scalene triangle)
What nerve might be injured if the arm cannot be abducted above the horizontal position?
Long thoracic nerve, serratus anterior, winged scapula
Injury when you see foot drop and loss of sensation on dorsum of foot? Where is the injury likely?
Common perineal (fibular), fibular neck
What nerve and muscle can result in trendelenurg sign/gait? Which side is injured relative to the sign
Superior gluteal nerve to the gluteus medius, lesion is on the opposite side that the lower hip is on
Which nerve everts the foot? Which inverts?
Peroneal everts, tibial inverts
What is a good landmark for pudendal nerve anesthesia?
Ischial spine
What artery is associated with the axillary nerve at the surgical neck of the humerus?
Posterior circumflex artery
What artery is associated with the long thoracic nerve?
Lateral thoraci artery
Where would you find the tibial nerve and artery at the ankle?
Posterior to the medial malleolus (tom, dick, and harry)
Describe the T-tubules and terminal cistern in skeletal and cardiac muscle
Skeletal: triad- 1 t-tubule+ 2 terminal cisternae
Cardiac: dyad- 1 t-tubule+ 1 terminal cisterna
What receptor at the sarcoplasmic reticulum is voltage-sensitive?
Dihydropyridine (it is coupled with the ryanodine receptor)
What causes the muscle power stroke?
Release of bound ADP and Pi by myosin
Which bands shorten in muscle contraction?
H band and I band (also distance between Z lines)
What amino acid is needed to synthesize arginine?
arginine
Is phosphorylated or dephosphorylated smooth muscle myosin actively contracting?
Phosphorylated
What type of bone formation is responsible for the base of the skull? Calvarium? Facial bones?
Base of the skull (and long bones): endochondral
Calvarium and facial bones: membranous ossification
Where do osteoblasts come from (cell line)?
Mesenchyme in periosteum
Why do achondroplasia patients have a large head relative to limbs? Genetic defect? What happens to homozygotes?
Because endochondral formation is affected and intramembranous ossification is not. Activating mutation of FGFR3. Homozygosity is lethal (AD)
What lab values are telling of osteoporosis? What part of the bone is lost?
None, labs are normal. Cortical and trabecular thinning
What is denosumab?
Monoclonal antibody against RANK-L
What mutation can cause osteopetrosis? What happens to the bone marrow? Tx?
Defective osteoclasts possibly caused by a carbonic anhydrase II mutation. The bone marrow may be filled in causing pancytopenia and extra medullary hematopoiesis. BMT is potentially curative as osteoclasts are derived from monocytes
What lab finding will you see in osteomalacia/rickets?
Increased osteoblast activity: increase in ALP (also typically low vitamin D)
What stage is first in Paget disease? What are two feared complications?
Osteoclastic. Arteriovenous malformations in new bone may cause high output heart failure. It also increases osteosarcoma risk
What artery is responsible for AVN of the femoral head?
Medial circumflex femoral artery
Soap-bubble appearance tumor. Where is it? What cell type?
Giant cell tumor. Typically epiphyseal end of long bones. ONLY EPIPHYSEAL TUMOR. Osteoclastoma/ multinucleate giant cells
What part of the bone do you expect to see osteosarcoma in? Ewing sarcoma?
Osteosarc: metaphysis
Ewing: diaphysis
What tumor is associated with onion skin periosteal reaction in bone? Mutation?
Ewing: t(11:22) (EWS-FLI-1)
What HLA is associated with RA? Antibodies? What is RF?
HLA-DR4, anti-CCP and RF( IgM to Fc of IgG)
Is osteoarthritis symmetric? Is RA?
RA is, osteoarthritis is not
How long must morning stiffness last in RA?
More than 1 hour
Does osteoarthritis or RA affect DIP?
Osteoarthritis
What would the histology of a rheumatoid nodule show?
Fibrinoid necrosis with palisading histiocytes
What is Caplan syndrome?
RA + pneumoconiosis
Which glycogen storage disease can cause gout?
Von-Gierke
What is the composition of pseudo gout crystals?
Calcium pyrophosphate
What finding in the joint, besides crystals is relatively specific for pseudo gout?
Chondrocalcinosis
Antibodies with Sjogren syndrome? Late enlarging parotid gland concern?
SS-A (anti-Ro), SS-B (anti-La)
MALT lymphoma
Triad with gonococcal arthritis?
Polyarthralgias, tenosynovitis, dermatitis
What are seronegative spondyloarthritis examples (4). What HLA? What does seronegative mean?
PAIR: Psoriatic arthritis, Ankylosing spondylitis, Inflammatory bowel disease, Reiters/Reactive
HLA-B27, no RF
Pencil in cup deformity of DIP on x-ray
Psoriatic arthritis
Heart problem associated with ankylosing spondylitis?
aortic regurgitation
Most common and severe renal involvement with Lupus?
Diffuse proliferative
Most common cause of death in lupus?
Cardiovascular disease
Which antibodies suggest poor prognosis with SLE?
Anti-dsDNA (renal disease)
Antihistone antibodies are sensitive for what?
Drug induced lupus
Recurrent thrombosis, spontaneous abortion in autoimmune patient? Necessary lab?
Antiphospholipid syndrome (lupus anticoagulant, anticardiolipin, or anti-beta2 glycoprotein antiboidies)
anti-U1 RNP antibodies?
MCTD
What finding will be in a sarcoid patient bronchoalveolar lavage fluid sample?
Elevated CD4+/CD8+ ratio
Treatment for a 20-50 yr old woman with widespread chronic MSK pain, poor sleep, stiffness, cognitive disturbances.
Fibromyalgia: TCAs, SNRIs, regular exercise, anticonvulsants
Antibodies in polymyositis/dermatomyositis?
anti-Jo (anti-histidyl tRNA), anti-SRP, anti-Mi-2
What type of cells and muscle inflammation are associated with polymyositis? Dermato?
Dermato: CD 4+ perimysial inflammation
Poly: Endomysial CD8+ inflammation
Both are progressive symmetric proximal muscle weakness
Fingertip pitting is associated with what?
Scleroderma
What is the most common cause of death with scleroderma?
Pulmonary sclerosis
Antibodies with scleroderma and CREST?
Scleroderma: anti-Scl-70 (anti DNA topoisomerase I)
CREST: anti-centromere
Color change in raynaud? What is raynaud syndrome vs. disease? Tx?
White to blue to red. Syndrome is secondary to a disease process, disease if primary. Tx with CCBs
Which layer of the epidermis has stem cells? What enzyme activity will be high here?
Stratum basale- telomerase
What filaments give desmosomes support?
Cytokeratin and desmoplakin
What forms adherens junctions? Significance of these junctions?
Cadherins connecting actin cytoskeletons of adjacent cells. Loss of E-cadherins promotes metastasis
What is the function of integrins? What do they bind to?
Maintain integrity of basolateral membrane by binding to COLLAGEN (via fibronectin) and LAMININ in the basement membrane
What is hyperkeratosis? What is parakeratosis?
Hyperkeratosis is thickening of the stratum corneum while parakaratosis is hyperkeratosis with retention of nuclei in the stratum corneum
Where is the edematous fluid in spongiosis?
Epidermis (intercellular spaces)
Difference in albinism and vitiligo?
Albinism is a inability to produce melanin (normal melanocyte number), vitiligo is a decrease in melanocyte number due to autoimmune destruction
What is another name for atopic dermatitis? What will you see in the serum? Location on body?
Eczema. increased IgE. On face in infants, then in antecubital fossae
Acanthosis with parakeratotic scaling and small microabscesses
Psoriasis
What layers are thickened in psoriasis? Decreased?
Corneum and spinosum are increased and the granulosum is decreased
Inflammatory facial skin with erythema and no comedones. May be associated with facial flushing in response to external stimuli like alcohol or heat.
rosacea
What causes hives/urticaria? Where is the edema (fluid)?
Mast cell degranulation, fluid is in the superficial DERMIS
What cancer is associated with vinyl chloride and arsenic exposures?
Hepatocellular angiosarcoma
How do you distinguish between bacillary angiomatosis and kaposi sarcoma?
BA: neutrophilic infiltrate
Kaposi: lymphocytic infiltrate
What should you consider in an ulcerative/bleeding mouth lesion in a pregnant woman?
Pyogenic granuloma (it’s benign even though it looks nasty)
Which has well defined borders? Erysipelas or cellulitis?
Erysipelas
What layers of skin are involved in staphylococcal scalded skin syndrome? TEN/SJS?
SSSS: Destroyed keratinocyte attachments in GRANULOSUM only (Nikolsky sign)
TEN/SJS: dermal-epidermal junction
Treatment for dermatitis herpetiformis?
Dapsone, gluten free diet
What percent of the body must be involved for it to be classified TEN? SJS?
TEN: >30%
SJS:
What type of cancer can actinic keratosis evolve into?
SCC
What is inflammatory lesions of subcutaneous fat, usually on anterior shins?
Erythema nodosum
Pruritic, purple, polygonal, planar, papules and plaques. What does mucosal involvement look like? Association? Histology?
Lichen Planus, mucosal involvement is Wickham striae
Sawtooth infiltrate of lymphocytes at dermal-epidermal junction. Associated with hepatitis C
“Christmas tree distribution” rash on trunk
Pityriasis rosea (regresses in 6-8 weeks)
What type of radiation causes sunburn? Tanning and photo aging?
UVB= sunBurn
UVA=tAnning and photoAging
Pink pearly nodules with telangiectasias,rolled borders and central crusting or ulceration.
Basal cell carcinoma
Which skin cancer has palisading nuclei?
BCC
Keratin pearls skin cancer? What does it look like grossly?
SCC, ulcerative red lesions with frequent scale
What do you suspect in a rapidly growing skin cancer that has a large keratin filled center?
Keratoacanthoma- a SCC variant that grows rapidly and may spontaneously regress over months
What mutation is often associated with melanoma? What drug targets this mutation?
BRAF V600E (kinase) vemurafenib is a BRAF kinase inhibitor
What is a PGI2 drug? PGE1? PGE2? What are PGE2 agonists used for?
PGI2= epoprostenol PGE1= alprostadil PGE2= dinoprostone, carboprost to increase uterine tone
What acid base disorder is caused by aspirin toxicity?
Mixed metabolic acidosis-respiratory alkalosis (resp. all early)- note also causes tinnitus
What is the effect of NSAIDs on stomach and kidney? How?
Gastric ulcer since PGs protect gastric mucosa and renal ischemia since PGs vasodilator afferent arteriole
Leflunomide MOA
Reversibly inhibits dihydroorotate dehydrogenase, preventing pyrimidine synthesis
What are bisphosphanates analogs of? What do they do?
Pyrophosphate, bind hydroxyapetite in bone, inhibiting osteoclast activity
Odd side effects of bisphosphonates?
Esophagitis, osteonecrosis of the jaw, atypical stress fractures
What is teriperatide?
Recombinant PTH
What does pegloticase do?
Probenecid?
Pegloticase: catalyzes uric acid metabolism to allantoin (water-soluble)
Probenecid: prevents reabsorption of uric acid in PCT, also inhibits penicillin secretion (can cause uric acid caliculi)
What is infliximab? Adalimumab?
Both are anti-TNF-alpha monoclonal antibodies
What is related to most achondroplasia mutations?
Sporadic and related to increased paternal age
What causes blue sclerae in OI?
Thinning of scleral collagen reveals underlying choroidal veins
What renal problems are associated with osteopetrosis?
Renal tubular acidosis (decreased carbonic anhydrase II results in decreased reabsorption of HCO3-
What causes frontal bossing in Rickets?
Osteoid deposition on the skull
What can possibly cause the onset of Paget disease of bone?
Viral infection such as paramyxovirus
Does Paget disease involve the entire skeleton?
No, it is a localized process
Bone pain plus systemic signs of infection
Osteomyelitis
What are sequestrum and involucrum?
Sequestrum is bone abscess and involucrum is the sclerosis around it in osteomyelitis
What is Gardner syndrome? Where are the tumors?
FAP +osteomas (face) and fibromatosis
What are the two main differences in osteoid osteoma and osteoblastoma?
O-O: cortex of long bone and presents as bone pain that RESOLVES WITH ASPIRIN
Osteoblastoma is larger, arises in the vertebrae and presents as bone pain that does NOT RESPOND TO ASPIRIN
Most common benign tumor of bone?
Osteochondroma (stalk)
Where do osteosarcomas arise?
Metaphysis of long bones
What cell line do Ewing Sarcomas arise from?
Neuroectoderm
Where do benign cartilage tumors typically originate? Malignant?
Benign: periphery
Malignant: central
What metastatic tumor to bone will produce an OSTEOBLASTIC lesion?
Prostate carcinoma
What is the major risk factor for osteoarthritis?
age
What histology does a rheumatoid nodule resemble?
Caseating granuloma
What are two extra-articular manifestations of ankylosing spondylitis?
Uveitis and aortitis (leads to aortic regurgitation)
Sausage fingers or toes?
Psoriatic arthritis
What might cause dermatomyositis?
It can be a paraneoplastic syndrome (e.g. gastric carcinoma)
If you hear lipoblast cell in a soft tissue situation, what should you think?
Liposarcoma
What is cardiac rhabdomyoma associated with?
Tuberous sclerosis
Cluster of grapes in young girl vagina?
Rhabdomyosarcoma (sarcoma botryoides)
What type of HSR is eczematous dermatitis?
Also called atopic dermatitis (type 1 HSR)
What type of glands are in acne? Name and classification
Sebaceous glands, holocrine
What does propionibacterium acnes do in sebaceous glands?
Produces lipase’s that break down sebum, releasing pro inflammatory fatty acids
How do benzoyl peroxide and isotretinoin treat acne?
Decrease keratin production
What layer of the skin do you see Munro micro abscesses in?
corneum
Sawtooth appearance of dermal epidermal junction. Association?
Lichen planus, Chronic hep. C
Targetoid rash and bullae, most common association? What if it has oral mucosa/lip involvement and fever?
Erythema multiforme, HSV, SJS
What is an odd risk factor for squamous cell carcinoma of the skin?
Immunosuppression (also AK, Arsenic)
What causes a freckle (ephelis)?
Increased number of melanosomes (not melanocytes)
What is the most common type of mole in adults? Where do nevi begin?
Intradermal, begin at dermal-epidermal junction (junctional)
Most important prognostic factor in predicting melanoma metastasis?
Depth of extension
What is formed in pseudo glandular phase of lung development? Canalicular? Saccular? When is respiration capable?
Pseudoglandular: terminal bronchioles
Canalicular: respiratory bronchioles and alveolar ducts (respiration possible here at 25 weeks)
Saccular: terminal sacs
What is the function of club cells?
Degrade toxins, act as reserve cells.
What is the relationship between radius and collapsing pressure? How does surfactant alter the collapsing pressure?
Increased radius means decreased collapsing pressure.
Surfactant decreases surface tension which decreases collapsing pressure
What is the L:S ratio in a lung that is healthy? What is the most important lecithin?
L:S >2 is healthy, the most important in surfactant is dipalmitoylphosphatidylcholine
What dos the foam stability index test measure?
Surfactant levels/ fetal lung maturity
What is a major complication of neonatal respiratory distress syndrome?
Necrotizing entercolitis
What three things can therapeutic O2 supplementation cause in a newborn?
Retinopathy of prematurity, Intraventricular hemorrhage, Bronchopulmonary dysplasia
Where does cartilage end? Goblet cells? Smooth muscle? Cilia?
Cartilage and goblet cells to end of bronchi
Smooth muscle to end of terminal bronchioles
Cilia terminate in respiratory bronchioles
What is the difference in lung volumes and capacities?
Volumes are non-overlapping, capacities are the sums of multiple lung volumes
Normal tidal volume and dead space volume?
Vt=500mL
Vd=150mL
What are alveolar, intrapleural, and airway pressures at FRC?
Alveolar and airway are 0 (no air moving), intrpleural pressure is negative (~-5)
What happens to lung compliance in normal aging?
Increases (e.g. COPD)
Which form of hemoglobin has high affinity for O2? Low?
Taut has low (deoxygenated), relaxed has high
What causes the difference in O2 affinity with fetal hemoglobin?
Decreased affinity for 2,3 BPG (higher affinity for O2 so it can be stolen from mom)
Chocolate colored blood. What is it? Can it be useful? Treatment?
Methemoglobinemia (Fe3+ that doesn’t bind O2)
Can be used to treat cyanide poisoning (nitrites followed by thiosulfate) because it has a higher affinity for CN than normal hemoglobin
Tx: Methylene blue and Vitamin C
What does caroxyhemoglobin do to Hb saturation curve?
Left shift (increased O2 affinity and won’t let go)
What poisoning can give a burnt almond smell?
Cyanide
When might oxygen demonstrate diffusion limited exchange? Will CO2 ever do this?
Fibrosis, emphysema (normally perfusion limited), no CO2 is never diffusion limited
What is the normal A-a gradient?
10-15 mmHg
Is V/Q ratio normally perfusion or ventilation driven?
Perfusion driven (V/Q is higher at apex and lower at base due to gravitational effects on blood flow)
Does 100% O2 help with V/Q of 0? What about infinity?
0=airway obstruction–> O2 doesn’t help
infinity=blood obstruction–> O2 does help
How is most CO2 transported in plasma?
As bicarbonate (90%)
Is Cl- higher in venous circulation or arterial? Why?
Arterial. At peripheral tissue, HCO3- produced in RBCs from the CO2 that it just picked up. This HCO3- is transported out of the cell in exchange for a chloride ion
What kind of acid-base disturbance is seen with moving to high altitude?
Respiratory alkalosis since ventilation increases to try to compensate for the lower oxygen in the air
How do PaCO2 and PaO2 change with exercise?
They don’t but venous CO2 content and O2 content do change
What sinus is typically involved in rhinosinusitis? Where does it drain? Most common cause?
Maxillary sinus that drains into middle meatus. Most common cause is viral URI which may cause superimposed bacterial infection
The sphenopalatine artery is a branch of what artery?
Maxillary
What is the virchow triad?
Stasis, Hyper-coagulability, Endothelial damage
Imaging test of choice for DVT?
Compression ultrasound
Do you see lines of Zahn in thrombi formed before or after death? What are the lines?
Before
pink=fibrin/platelets, red=RBCs
What is the classic triad of fat emboli?
Hypoxemia, neurologic abnormalities, petechial rash
Does high or low V/Q ratio cause problems in PE?
Low. Although the PE directly causes a high V/Q, it indirectly causes a low V/Q in the areas where blood is shunted. The oxygenation cannot keep up with the blood flow to these areas.
What is the Reid index? What is it in chronic bronchitis?
Thickness of mucosal gland layer to thickness of wall between epithelium and cartilage (>50%)
Describe centriacinar and panacinar emphysema
Centriacinar: smoking, upper lobes,
Panacinar: alpha-1 antitrypsin deficiency, lower lobes
What are Curschmann spirals and Charcot-Leyden Crystals formed from?
Curschmann: shed epithelium
Crystals: breakdown of eosinophils in sputum
What test helps diagnose asthma? What cardiac finding accompanies it?
Methacholine challenge, pulsus paridoxicus
Scoliosis and obesity can lead to what type of lung disease?
Restrictive
What type of HSR is hypersensitivity pneumonitis?
HSR types III and IV
Golden-brown fusiform rods resembling dumbbells (iron)
Asbestos bodies (ferruginous bodies)
Looks like sarcoid except the person works in aerospace industry and has less systemic symptoms
Berylliosis
What pneumoconiosis increases TB susceptibility? How?
Silicosis by disrupting phagolysosomes and impairing macrophages
Eggshell calcification of hilar lymph nodes
silicosis
What is the first step in ARDS? What cells are responsible for the initial damage?
Endothelial damage due to release of neutrophilic substances toxic to alveolar wall
At what pressure can we diagnose pulmonary HTN?
> 25 mm Hg at rest for mean pulmonary artery pressure
Arteriosclerosis, medial hypertrophy and intimal fibrosis of pulmonary arteries
Pulmonary Hypertension
What mutation can cause heritable PAH? What random bug can cause PAH?
inactivating mutation in BMPR2 gene (normally inhibits vascular smooth muscle proliferation). Schistosomiasis
When is fremitus over the lungs increased?
Consolidation such as lobar pneumonia
Milky appearing pleural effusion is from what?
Thoracic duct injury from trauma or malignancy (contains TGs)
Empiric treatment for lung abscess?
Clindamycin
Where are aspiration abscesses when: patient is supine, upright?
Supine: posterior right upper lobe or superior right lower lobe
Upright: basal right lower lobe
Is cytokeratin positive in mesothelioma? Carcinoma? What about calretinin?
Cytokeratin and calretinin are positive in almost all mesotheliomas and negative in most carcinomas.
Is smoking a mesothelioma risk factor?
No
Compression of what nerve by a pancoast tumor causes hoarseness?
Recurrent laryngeal
Seems like a lot of blood in head and neck, but not lower body?
SVC syndrome due to malignancy or thrombosis from indwelling catheters
What cancer is associated with subacute cerebellar degeneration? Mutation?
Small cell, L-myc activation
Name 3 activating mutations with adenocarcinoma of the lung. What is an associated physical finding?
KRAS, EGFR, ALK. Hypertrophic osteoarthropathy (clubbing)
What lung cancer can secrete B-hCG?
Large cell carcinoma
What is guaifenesin?
Expectorant. Things respiratory secretions but does not suppress cough reflex
How does N-acetylcysteine work for COPD patients?
Liquifies mucus by disrupting disulfide bonds
What drugs are good for aspirin induced asthma?
Antileukotrienes (e.g. montelukast)
What is omalizumab?
Binds unbound serum IgE and blocks binding to Fc
Inflammation of nasal mucosa with eosinophilic infiltrate.
Allergic rhinitis (associated with asthma and eczema)
Nasal polyp in kid? Adult?
Kid: CF
Adult: aspirin intolerant asthma
How would you expect an angiofibroma to present?
Adolescent males with profuse epistaxis (benign tumor of nasal mucosa)
Benign papillary tumor of the vocal cord?
Laryngeal papilloma (HPV 6,11)
Where does a laryngeal carcinoma come from?
Epithelial lining of true vocal cord
What form of pneumonia do viruses usually cause?
Atypical (interstitial) pneumonia
What is the difference in red and gray hepatization in lobar pneumonia?
Hemorrhage (RBCs) are in red, they are degraded in gray
What causes cold hemolytic anemia in mycoplasma? Specifically what Ig and what antigen on RBC?
I antigen (i) on RBC is targeted by IgM
Where is primary TB located? Secondary?
Primary in lower lobe, secondary in apex
What part of the meninges will TB spread to?
Base of brain
What happens to PaCO2 and PaO2 in chronic bronchitis? Why?
PaCO2 increases and PaO2 decreases due to mucus plugs
Most common cause of emphysema?
Smoking
What might A1AT deficiency cause besides emphysema? Histology?
Liver cirrhosis: mutant (misfolded) A1AT accumulates in the ER of hepatocytes resulting in pink, PAS (+) globules in hepatocytes
What are the two alleles for A1AT deficiency?
PiM is normal, PiZ is mutant
PiMZ: usually asymptomatic but up risk with smoking
PiZZ: significant risk for panacinar emphysema and cirrhosis
What type of T-cells mediate asthma initiation?
1st exposure causes Th2 cells to secrete IL-4 (class switch to IgE) and IL-5 (attracts eosinophils) and IL-10 (stimulates Th2, inhibits Th1). Reexposure causes IgE-mediated mast cell degranulation
What eosinophilic product is a major mediator of asthma inflammation (later stage)
Major basic protein
What type of lung problem does allergic bronchopulmonary aspergillosis cause?
Bronchiectasis
What induces fibrosis in IPF? What does it initially look like on CT? Eventually?
TGF-beta from injured pneumocytes
Initially is sub pleural, patchy fibrosis that eventually becomes diffuse with “honeycomb” lung
Asteroid/stellate bodies in giant cells?
Sarcoid
What if you see salivary and lacrimal gland destruction along with non-caseating granulomas in hilum?
Sarcoid, be careful with Sjogrens
Plexiform lesions in lungs
Pulmonary hypertension
What is the relation of maternal diabetes to NRDS?
Insulin decreases surfactant production
Why do you see necrotizing entercolitis and PDA with NRDS?
NRDS–> hypoxemia–> causes Nec.E and PDA
What is the second most frequent cause of lung cancer in US? How are we exposed?
Radon exposure, uranium in the soil decays to radon (ex. can be in basements)
Tumor composed of lung tissue and cartilage that may be calcified (in lung)
Bronchial hamartoma
What type of lung cancer is not amenable to surgical resection?
Small cell carcinoma
What cancer often forms a polyp-like mass in the bronchus?
Carcinoid tumor
What is a unique site of metastasis for lung tumors?
Adrenals
What serves as the interim kidney for the first semester? What forms the final kidney?
Interim: mesonephros
Final: metanephros
What parts of the kidney does the ureteric bud form? What layer is the rest of it from?
From ureter back to collecting ducts. The rest is formed by metanephric mesenchyme (glomerulus through DCT)
How does the metanephros part of the kidney form?
Induced by infiltration by the ureteric bud
What is a multicystic dysplastic kidney?
Nonfunctional kidney consisting of cysts and connective tissue
What is the pattern of blood flow through the kidney?
segmental, intralobar, arcuate, intralobular, afferent arteriole, glomerulus, efferent arteriole,peritubular capillaries/vasa recta
What is the JG apparatus?
Modified SM cells between the DCT and afferent arteriole that is responsible for renin secretion
What substance can be used to measure plasma volume? Extracellular volume?
Albumin for plasma volume, inulin/mannitol for extracellular volume
How much water is in each body compartment?
60% total body water, 40% ICF, 20% ECF
Plasma=25% ECF
Does creatinine clearance over or underestimate GFR? What about PAH with total renal plasma flow?
Creatinine overestimates slightly (some is secreted)
PAH underestimates slightly (some gets through)
Where do prostaglandins and ang. II have their effects on the renal vasculature?
Ang. II constricts the efferent arteriole while PGs dilate the afferent arteriole
How is glucose reabsorbed in the PCT?
Na+/glucose cotransport
How does PCT reabsorption affect tonicity?
It is isotonic
Where does PTH act to secrete phosphate and resorb calcium?
Phosphate in the PCT, Calcium in the DCT (e.g. thiazides)
What does angiotensin II do at the PCT?
Stimulates Na+/H+ exchange causing increased Na+, H20 and HCO3- reabsorption
How does the TALH cause Mg2+ and Ca2+ reabsorption?
The Na/K/2Cl transporter allows only forward motion of Na and Cl but allows K+ back leak. This causes a positive luminal potential that can drive cations through
Is the TALH permeable to water? DCT?
No and no
Where does urine become fully dilute?
Early DCT
Where is the most ANYTHING reabsorbed? Potentially besides Calcium and magnesium
PCT
How do thiazides cause calcium reabsorption?
If the Na-Cl cotransporter is blocked, the only way to provide sodium for the Na/K ATPase is through interstitial exchange of calcium from sodium. This allows more calcium influx from the lumen and the cycle continues (basically PTH does the same thing here)
What is fanconi syndrome? What notable drugs can cause it?
Generalized reabsorption defect in the PCT, expired tetracyclines
Locations of Bartter, Gitelman, Liddle Syndrome? Inheritance?
Alphabetic order Bartter: TALH (~loop diuretics) Gitelman: DCT (~thiazides) Liddle: Collecting ducts (~aldosterone, ACTIVATING) All are AR except Liddle is AD
What is syndrome of apparent mineralocorticoid excess? What else can cause it?
Hereditary deficiency of 11beta-hydroxysteroid dehydrogenase which normally converts cortisol to cortisone in aldosterone tissues. If not, cortisol acts on these receptors as if it was aldosterone.
Glycyrrhetinic acid from licorice
What happens to inulin concentration in the PCT along the length of it?
It increases in concentration but not amount due to water reabsorption
What three stimuli cause increased renin secretion?
decreased BP (JG cells) decreased Na+ delivery to DCT (macula densa) Beta-1 sympathetic activation (sympathetic tone)
Why do you not really see reflex bradycardia with angiotensin II?
It limits baroreceptor function
Where is Epo released from?
Interstitial cells in peritubular capillary bed
What does dopamine do to kidney function?
Secreted by PCT cells and promotes natriuresis.
Low dose: vasodilates everything in kidney
High dose: vasoconstrictor
Abdominal pain, kidney stones and mental disturbances?
Hypercalcemia
How do you calculate anion gap? What is normal?
Na-(HCO3+Cl), normal is 8-12
What should you check for in metabolic alkalosis?
Chloride
What is RTA type 1? Type 2? Type 4? Which is hyperkalemia?
Type 1: alpha-intercalated cells don’t secrete H+
Type 2: Defect in PCT HCO3- reabsorption
Type 4: Hypoaldosteronism–> hyperkalemia–> decreased NH3 synthesis in PCT and NH4+ excretion
In which RTA type is urine pH increased above 5.5?
Type 1, alpha intercalated cells are normally responsible for acidifying the urine
What causes type II RTA?
Fanconi syndrome and CAII inhibitors
If there are casts in the urine, where must the damage be?
Glomerulus or renal tubules
As nephrotic means protein, what does nephritic mean?
Inflammation–> hematuria
Starry sky granular appearance on IF? Also called lumpy-bumpy.
PSGN
What complement protein is associated with PSGN?
C3, thus serum C3 is decreased
Where are the immune complexes deposited in PSGN?
Subepithelial
What is the severe renal problem associated with lupus? Characteristic LM finding?
Diffuse proliferative glomerulonephritis.
Wire looping of capillaries
Episodic gross hematuria that occurs concurrently with respiratory or GI tract infections
IgA nephropathy (Berger disease, note NOT BUERGER disease)
Alport syndrome inheritance?
X-linked dominant
MPGN type I has what appearance on microscopy? What is type I associated with? Type II?
Tram track appearance
Type I: Hepatitis B or C (or idiopathic)
Type II: C3 nephritic factor (stabilizes C3 convertase causing down serum C3 levels)- dense deposit disease
What are the clinically significant effects of protein loss in nephrotic syndrome?
1) AT III loss–> hypercoagulability
2) Loss of Ig–> increased infection risk
What EM appearance do you see with membranous nephropathy (membranous glomerulonephritis)
Spike and dome appearance with subepithelial deposits
What antibodies are associated with Membranous Nephropathy?
Antibodies to Phospholipase A2 receptor
What is the most common kidney stone? Serum and urine findings?
Calcium oxalate stone in patient with hypercalciuria and normocalemia
What two kidney stones precipitate in low pH? High pH?
Low: uric acid and cystine
High: Ammonium magnesium phosphate, calcium phosphate
Which kidney stones are radiolucent?
Uric acid and cystine
What causes calcium oxalate stones?
Hypocitraturia
What do you suspect with a positive sodium cyanide nitroprusside test?
Cystine stones
Dilation of renal pelvis and calyces
Hydronephrosis
Well circumscribed kidney mass with central scar and large eosinophilic cells. Tx? What cells does it arise from?
Renal oncocytoma, often resected to exclude malignancy
Arises from collecting duct cells
What cell does renal cell carcinoma arise from?
PCT cells
What is WAGR complex?
Wilms tumor, Aniridia, GU malformations, Retardation
Chromosome for wilms tumor?
11
What is suggested by painless hematuria with no casts?
Bladder cancer
What can cause squamous cell carcinoma of the bladder?
Chronic irritation–> metaplasia–> cancer
E.g. schistosoma haematobium
Are there systemic signs with urinary tract infections?
No, usually only with pyelonephritis
What does positive urine nitrites indicate?
Gram negative bacteria
WBC casts and WBCs in urine suggests what?
Acute pyelonephritis
Are the glomeruli/vessels or cortex more affected with acute pyelonephritis?
Cortex, glomerulus mostly spared
What does thyroidization of the kidney indicate?
Chronic pyelonephritis (usually means something like vesicoureteral reflux or chronically obstructing stones)
What is renal osteodystrophy? What area of bones is affected?
Hypocalcemia, hyperphosphatemia, and failure of vitamin D hydroxylation with chronic renal disease. Causes subperiosteal thinning of bones
Serum BUN/Cr in prerenal vs. intrinsic renal failure
Prerenal: BUN/Cr >20
Intrinsic: BUN/Cr
What type of dyslipidemia is a consequence of renal failure?
Triglyceridemia
Pyuria of eosinophils and azotemia?
Acute interstitial nephritis
What is the effect on potassium levels of the maintenance and recovery phase of ATN?
Maintenance: risk of hyperkalemia (kidney can’t get rid of it)
Recovery: risk of hypokalemia (kidney is working well again)
Gross hematuria and proteinuria with sloughing of necrotic renal papillae
Renal papillary necrosis
Chromosomes for PKD1 and PKD2 in adult polycyctic kidney disease?
16, 4 respectively
What is dilated in AR polycystic kidney disease? Association?
Collecting ducts, hepatic fibrosis and hepatic cysts
What diuretic is CI in anuria?
Mannitol
Effect of loop diuretics on afferent arteriole?
Stimulate PGE release and thus afferent vasodilation
What is ethacrynic acid?
Non-sulfa loop inhibitor. More ototoxic
What is metolazone?
Thiazide diuretic
What are the effects of thiazides on glucose, lipids, uric acid?
hyper all of them
What does inhibition of ACE due to bradykinin?
Prevents inactivation (it is a potent vasodilator)
What is aliskiren?
Direct renin inhibitor (blocks angiotensinogen conversion to Ang. I)
How is dysplastic kidney inherited?
It isn’t, risk in subsequent pregnancy is very low
Baby with portal hypertension?
Polycystic kidney disease
ARF with oxalate crystals in the urine?
Ethylene glycol toxicity
What lipid changes are seen with nephrotic syndrome?
Hyperlipidemia and hypercholesterolemia to keep the osmolarity of the serum high
What might MCD be associated with rarely?
Hodgkin lymphoma
Which nephrotic syndrome will respond to steroids?
MCD
What nephritic and nephrotic syndromes are associated with SLE?
Nephrotic: Membranous nephropathy (caucasian one)
Nephritis: DPGN (severe)
Which kidney pathologies are associated with HBV and HCV?
Membranous nephropathy and membranoproliferative glomerulonephritis (type 1: tram tracks)
What is C3 nephritic factor? What is it associated with?
It is an autoantibody that stabilizes c3 convertase causing over activation of complement. Associated with dense deposit disease (Type II MPGN)
Why do you see microalbuminuria in diabetes?
Preferential hyaline arteriolosclerosis of the efferent arteriole causes hyper filtration (higher filtration pressure)
What are crescents composed of in RPGN?
Fibrin and macrophages
What type of nephritic syndrome does lupus cause? Broad class and specific?
DPGN which is crescentic glomerulonephritis
Can’t pee, can’t see, can’t hear a buzzing bee
Alport syndrome
Scarring at upper and lower kidney poles is characteristic of what?
Vesicoureteral reflux
What kidney stone is most commonly seen in children?
Cystine stones
What occurs with cystic development during dialysis?
Increased risk for renal cell carcinoma
What is angiomyolipoma associated with?
Tuberous sclerosis
How does VHL mutation cause renal carcinoma?
VHL leads to increased IGF-1 and increased HIF transcription factor which increases VEGF and PDGF
Major risk factor for sporadic renal carcinoma?
Cigarette smoke
Popular syndrome with Wilms tumor?
WAGR: Wilms, Aniridia, Genital abnormalities and Retardation
What are the two pathways to develop urothelial carcinoma? Describe the differences
1) Flat: starts high grade, flat development, EARLY p53 mutation
2) Papillary: low grade to high grade to invasion
In what circumstance can an adenocarcinoma arise in the lower urinary tract?
urachal remnant
What is the life span of RBCs and platelets?
RBC: 120 days
Platelets: 8-10 days
Why are reticulocytes blue on Wright-Giemsa stain?
residual ribosomal RNA
Where are platelets stored? How much?
1/3 stored in spleen
Where do you find collagenase, lysozyme and lactoferrin? B-glucuronidase?
First three specific granules of neutrophils, last one in azurophilic granules of neutrophils
What about macrophages initiates septic shock?
Lipid A from bacterial LPS binds CD14 on macrophages to initiate septic shock
What cells contain heparin and histamine?
Basophils and mast cells
When do you see basophilia?
CML
What MHC can B cells use to function as an APC?
MHC II- important for class switching
What is “the Hoff” in plasma cells?
Large golgi apparatus
What do HbS and HbC replace glutamate with?
Valine and lysine (+) respectively
What is the typical hemophilia inheritance pattern? Exception?
XR, except hemophilia C (factor XI) is AR
How does tPA work?
Causes plasminogen to be activated to plasmin which cleaves fibrin clots
What enzyme is required to activate vitamin K to be a cofactor for gamma-glutamyl carboxylase?
Epoxide reductase (warfarin targets this VKOR)
What clotting factor does vWF carry and protect? Which factor dies first?
VIII, VII
What mediates the transient vasoconstriction following endothelial damage?
Endothelin
What substance induces GPIIb/IIIa expression on platelets?
ADP
What is the MOA of clopidogrel? Ticlopidine? Abciximab? Tirofiban?
First two are ADP receptor blockers and the second two are direct GPIIb/IIIa inhibitors
What causes acanthocytes? Echinocytes? Difference?
Acanthocyte: abetalipoproteinemia
Echinocyte: more uniform and smaller projections
Echinocytes have projections that are more uniform and smaller
When do you see bite cells?
G6PD deficiency (post heinz body)
Where is the excess iron stored in ringed sideroblasts?
Mitochondria
What is a heinz body? Howell-Jolly body?
- Hb precipitates
- nuclear remnants in patients with hyposplenia/asplenia
What class of anemia does lead poisoning cause?
Microcytic (copper deficiency does too)
Spoon nails are associated with what?
Iron deficiency anemia
IDA, esophageal webs, dysphagia?
Plummer-Vinson Syndrome
What is HBH, Hb Barts?
HbH is 4 gamma chains and is seem with four allele deletion in alpha thal. Hb Barts is beta tetramers seen in 3 allele deletion in alpha thalassemia?
Who is more likely to have a cis deletion of the alpha thalasemia genes?
Asians
What is the genetic defect in beta thalassemia?
Point mutations in splice sites and promoter sequences
What two enzymes are inhibited by lead poisoning?
ALAD and ferrelchelotase
Where do you see lead lines?
Gingivae and metaphyses of long bones
What neuro signs do you see with lead poisoning? Treatment (what about kids?)
Foot and wrist drop
Dimercaprol and EDTA are 1st line, succimer used for chelation in kids
Defect in sideroblastic anemia? Causes?
X-linked defect in ALAS. Alcohol, lead, vitamin B6 deficiency, copper deficiency, INH
What is the treatment for sideroblastic anemia?
Vitamin B6
Defect in orotic aciduria? Blood findings?
Decreased UMP synthase, megaloblastic anemia refractory to folate and cobalamin
Difference in Diamond Blackfan anemia and fanconi anemia?
DBA is a defect in erythroid progenitor cells (actual anemia) associated with UE malformations. Fanconi anemia is DNA repair defect causing bone marrow failure, increased tumor chances, thumb/radial defects
What causes PNH? Treatment?
Impaired GPI anchor synthesis with holds DAF (CD55/59) onto RBCs. This deactivates complement normally to protect RBCs. Treatment is eculizumab (terminal complement inhibitor)
What causes warm hemolytic anemia? Cold?
Warm: IgG–> SLE and CLL
Cold: IgM–> mycoplasma and mono
What do corticosteroids do to WBC levels? how?
Increased neutrophils: impaired adhesion and migration out of blood
Decreased esoinophils: sequestered in LN
Decreased lymphocytes: apoptosis
Which step of heme synthesis requires vitamin B6 as a cofactor? What inhibits this step?
ALAS, heme/glucose
AIP and PCT enzymes?
AIP: PBGD
PCT: UROD
How does iron cause cell damage?
Peroxidation of membrane lipids
What causes immune thrombocytopenia?
Anti-GPIIb/IIIa antibodies (commonly due to viral illness)
What causes TTP? Pentad of sx?
ADAMTS13 deficiency (cleaves vWF multimers) Neuro sx, thrombocytopenia, hemolytic anemia, renal failure, fever
What is the inheritance of and treatment for vWF deficiency?
AD, treat with desmopressin
How do you detect antithrombin deficiency?
No direct effects, but causes a decrease in the PTT change with heparin administration.
What factors do proteins C and S target?
Five and eight
What electrolyte abnormalities may be caused by blood transfusion?
Hyperkalemia and hypocalcemia (citrate)
Which lymphoma type displays: noncontiguous spread? EBV association? Good prognosis?
Non-hodgkin, hodgkin, hodgkin
Cell markers for reed-sternberg cells?
CD 15 and 30
Cancer with lytic bone lesions and hypercalcemia besides multiple myeloma
Adult T-Cell Lymphoma
Atypical CD4+ cells with “cerebriform” nuclei and skin patches/plaques. What can it progress to?
Mycosis fungoides–> Sezary syndrome (T-cell leukemia)
Most common non-Hodgkin lymphoma in adults
DLBCL
Starry sky appearance? Where is the sporadic form? Mutation?
Burkitt, pelvis or abdomen, t(8:14) c-myc with Ig heavy chain
What might an eosinophilic protein in the urine make you consider? Blood finding?
Multiple Myeloma (Bence-Jones), Rouleaux formation
Neutrophils with bilobed nuclei: what are they and when do you see them?
Pseudo-Pegler-Huet anomaly and after chemotherapy
Indolent, waxing and waning lymphoma. Mutation?
Follicular lymphoma (BCL-2 t(14:18))
What does TdT+ mean? CD10+?
Lymphoblast (T or B cells), marker of pre B-cells
Which cancers are associated with Down syndrome?
B-ALL, AML
What are two odd places that ALL may spread to that require specific treatment? Mutation with good prognosis?
CNS and testes. t(12;21)
What do you suspect with CD20+, CD5+ cells? What type of cells are they? Specific finding?
CLL, B-cells, Smudge cells
Whats the difference with smudge and hairy cells on appearance?
Smudge cells are odd nuclei, hairy cells are talking about the cytoplasm
Hairy cell leukemia: Stains positive for what? Treatment?
TRAP+, Cladribine
What is a specific cell finding for AML? What is it? Translation? Treatment? Common presentation
Auer rods (myeloperoxidase), t(15;17), ATRA for treatment. Commonly presents as DIC
Basophilia suggests what?
CML
How do you differentiate CML neutrophils with a leukemoid reaction?
1) Low LAP as a result of low activity in malignant neutrophils
2) Increased basophils
3) Mutation (t(9;22)= BCR-ABL
Lytic bone lesions and skin rash or recurrent otitis media with mass involving mastoid bone. What do cells express?
Langerhans cell histiocytosis, S-100
Mutation with myeloproliferative disorders?
V617F JAK2
Severe, burning pain and red-blue coloration in extremities?
Erythromyalgia- rare but classic with PV, also possible with ET
What cancers can cause inappropriate absolute polycythemia as a paraneoplastic syndrome?
Renal cell carcinoma, hepatocellular carcinoma
What are the EPO levels in PV?
Low, feedback suppresses it
What does heparin work on?
Antithrombin III which lowers the activity of thrombin and factor Xa
Which is used in pregnancy, heparin or warfarin?
Heparin
How do you identify LMWH drugs? What do they do?
“-parin” is in name but not heparin. More specific for factor Xa
What antibody is associated with HIT?
IgG against platelet factor 4 (PF4)
What is bivalirudin?
Direct thrombin inhibitor derived from leech anticoagulant
What is streptokinase?
Thrombolytic
What is ticlopidine? Side effect?
ADP receptor blocker, neutropenia
What are cilostazol and dipyridamole?
Phosphodiesterase III inhibitors causing vasodilation and inhibition of platelet aggregation
What are eptifibatide and tirofiban?
GPIIb/IIIa inhibitors (“fib”), also abciximab
What activates azathioprine and 6-MP? What do they do?
HGPRT, purine analogs decreasing de novo purine synthesis
Side effects of cladribine (3)?
Myelosuppression, nephrotoxicity, neurotoxicity
What enzyme does 5-FU inhibit? How does leucovorin affect it?
Thymidylate synthase by covalently complexing folic acid. Leucovorin enhances the activity
What does methotrexate do? How does leucovorin affect it?
Dihydrofolate reductase inhibitor that is reversed by leucovorin.
What drug specifically acts in the G2 phase?
Bleomycin (free radical formation)
What drug is often used in childhood tumors?
Dactinomycin
What is the side effect of doxorubicin? What prevents it?
Cardiotoxicity (dilated cardiomyopathy) which can be prevented by dexrazoxane
How does cyclophosphamide work? Side effects? What prevents them?
Cross-links DNA at guanine N7.
Hemorrhagic cystitis prevented by mesna or NAC
What drugs are often used for brain tumors?
Nitrosoureas (-ustine, streptozocin)
How do you prevent cisplatin toxicity?
Prevent nephrotoxicity with amifostine and chloride diuresis
What is the MOA of irinotecan?
Inhibits topoisomerase I
What is the MOA of hydroxyurea?
Inhibits ribonucleotide reductase (DNA synthesis)
What is bevacizumab?Erlotinib? Cetuximab? Imatinib?
Monoclonal antibody against
VEGF, EGFR tyrosine kinase inhibitor, EGFR mab, tyrosine kinase inhibitor of BCR-ABL
What antibody increases the risk of PML?
Rituximab (CD 20)
What is Vemurafenib?
inhibit V600E BRAF mutation (V600E MUtated, bRAF INHIBition)
Toxicity of trastuzumab?
Cardiotoxicity (“heartceptin”)
What does vWF bind to besides platelets? Where does it come from?
Exposed subendothelial collagen. Weibel-Palade bodies and alpha granules of platelets
What is ITP caused by? What fixes it?
Plasma cells in the spleen produce IgG against platelet antigens like GPIIb/IIIa. Then spleen removes antibody bound platelets. Treatment is splenectomy
What is the effect of uremia on platelets?
Impairs both adhesion and aggregation
What activates factors XII and VII?
XII: sub endothelial collagen
VII: Tissue thromboplastin
What do you suspect with increased PTT that does not correct upon mixing normal plasma?
Coagulation factor inhibitor
Treatment for vWF disease? Inheritance?
AD, desmopressin which increase W-P body vWF release
What coagulation time can be watched for liver failure?
PT (factor VII is the first to go)
Why might you see thrombosis in HIT?
Because destroyed platelet fragments may activate remaining platelets (sort of paradoxical)
Name two odd things that can cause DIC. One is a cancer and the other is a toxin
Adenocarcinoma: mucin activates coagulation
Rattlesnake bite: venom activates coagulation
How does plasmin stop clotting? What stops plasmin?
Plasmin: 1) cleaves fibrin and fibrinogen
2) Destroys coagulation factors
3) Blocks platelet aggregation
It is stopped by alpha 2 antiplasmin
Name two things that can cause a disorder of fibrinolysis (plasmin over activation)
1) Radical prostatectomy: urokinase release activates plasmin
2) Cirrhosis: reduced alpha 2 antiplasmin production
Increased PT/PTT, increased bleeding time, increased fibrinogen split products. What is the platelet count? What is the treatment?
This is plasmin over activation (no D-dimer, increased FIBRINOGEN split). Normal platelet count. Treat with aminocaproic acid which blocks plasminogen activation
How do B12 and folate deficiency increase thrombosis risk?
They increase homocysteine levels by preventing conversion to methionine. Homocysteine damages endothelial cells and promotes thrombosis
What enzyme takes homocysteine to cystathionine?
cystathionine beta synthase (CBS)
Dyspnea and petichiae on skin?
Fat embolus (neuro sx too)
Squamous cells and debris in an embolus
Amniotic fluid embolus
What arteries provide dual supply to the lungs?
Pulmonary arteries and bronchial arteries
What is the general reason for microcytic anemia?
Decreased hemoglobin production–> extra division of RBC to maintain Hb concentration
What is heme composed of?
Iron and protoporphyrin
Where is iron absorbed?
Duodenum
Most likely causes of IDA in developing world elderly population?
Hookworms: Ancylostoma duodenale and Necator americanus
What is increased in erythrocytes in IDA?
Free erythrocyte protoporphyrin (FEP)
What causes sideroblastic anemia?
Decreased protoporphyrin synthesis (e.g. lead poisoning)
What step in protoporphyrin synthesis requires B6 as a cofactor?
ALAS
Where is iron trapped in sideroblastic RBCs? Why?
Iron is in the mitochondria because this is where it would normally join protoporphyrin to make heme
What drug can cause sideroblastic anemia? Habit? How?
INH causes B6 deficiency. Alcohol is a mitochondrial poison.
What is the state of iron in siderblastic anemia?
Iron overloaded state
Are the globin chains made in thalassemia defective?
No, just a decrease in synthesis
How many alpha thalassemia genes are there? Chromosome? What about beta?
Four alpha on chromosome 16
2 beta on chromosome 11
Which thalassemia is due to deletions and which to mutations?
Alpha is primarily due to deletions while beta is due to mutations
Which thalassemia is associated with extra medullary hematopoiesis?
Alpha
What causes macrocytic anemia generally?
Lack of DNA means RBCs cannot keep dividing and stay larger as a result
What is pernicious anemia? What deficiency is caused?
Autoimmune destruction of parietal cells leading to intrinsic factor and thus B12 deficiency
What is B12 converting that leads to SCD with deficiency? What step forms the MMA?
methylmalonylic acid to succinyl CoA
Propionyl CoA to MMA via Propionyl CoA carboxylase
What causes hemosiderinuria?
Renal tubular cells pick up some of the hemoglobin that is filtered into urine after intravascular hemolysis and break it down into iron. After cell builds up enough iron as hemosiderin it is shed and results in hemosiderinuria
Most common cause of death in adult sickle cell patients
Acute Chest Syndrome (vaso-occlusion in pulmonary microcirculation)
Where does sickling still occur in sickle cell trait?
Renal medulla (extreme hypoxia and hypertonicity)
What does the metabisulfate screen do?
Any cells with any amount of HbS sickle (trait and disease)
Why does PNH happen at night?
Mild respiratory acidosis with shallow breathing at night activates complement
What is the main cause of death in PNH? What cancer can develop and why?
Thrombosis of hepatic, portal or cerebral veins due to destroyed platelets releasing cytoplasmic contents
- AML, PNH is a defect in myeloid stem cells just like AML
Hemoglobinuria and back pain several hours after getting dapsone tx?
G6PD deficiency. Back pain since Hb is nephrotoxic
What is the cell mark on a heatopoietic stem cell that leads to myeloid and lymphoid cell lines?
CD34+
Why would severe infection cause leukopenia?
Increased movement of neutrophils into tissues
What is the most sensitive cell in the body to radiation?
Lymphocytes
What cell line leads to erythroblasts?
Myeloid stem cell
Decrease in what receptor indicates immature leukocytes?
Fc receptors (CD 16)
What is a notable case where you see eosinophilia? Basophilia?
Eosinophilia in Hodgkins lymphoma, basophilia in CML
What bacteria can produce lymphocytic leukocytosis?
Bordatella pertussis
What causes LAD in mononucleosis? Splenomegaly?
T-cell (CD8+) hyperplasia in lymph node paracortex and Periarterial lymphatic sheath (PALS)
What is TdT? When do you see it?
Lymphoblasts and it is a DNA polymerase
Which tumor is with down syndrome before 5 years old? After?
Before is AM (megakaryoblastic)L, After is ALL (LL= later later)
Leukemia that classically infiltrates gums?
Acute monocytic leukemia
What type of leukemia might myelodysplastic syndromes develop into?
AML
What do CLL cells express in regards to cell markers? What type of cells are they?
B cells that coexpress CD5 (normally on T cells) and CD20
Why do you get splenomegaly in Hairy Cell Leukemia?
They accumulate in the RED pulp (this is odd because WBCs normally live in white pulp)
What if you see lytic lesions, HSM, hypercalcemia and a rash?
ATLL (HTLV associated)
Aggregates of neoplastic CD4+ cells in the epidermis?
Pautrier micro abscesses with mycosis fungiodes
What can CML progress to? Why?
AML or ALL because the mutation is in a pluripotent stem cell
Does ET progress to marrow fibrosis or leukemia? Cause gout?
No and no, unlike other MPDs
What proliferates in myelofibrosis?
Megakaryocytets which produce excess PDGF and cause fibrosis of the marrow
In a lymph node draining a tissue with cancer, what area is hyperplastic?
Medulla (sinus histiocytes)
What three diseases are associated with marginal zone lymphoma? Another name of it? When is the marginal zone present?
Only present in chronic inflammation
H. pylori (MALToma), Hashimoto, Sjogren
Most common HL subtype? Best prognosis? Eosinophils?
Nodular sclerosis- most common
Lymphocyte-rich- best prognosis
Mixed cellularity- eosinophils
What IL might be high with multiple myeloma?
IL-6 stimulates plasma cell growth and Ig production
How does multiple myeloma cause bone lesions?
Activates RANK receptor on osteoclasts
What markers are positive in LCH?
CD1a+ and S100+