Heme/Onc Flashcards
TTP (thrombotic thrombocytopenic purpura) pathophys
- due to impaired function of ADAMTS13 (vWf-cleaving protease)
- vWf multimers are PRO-thrombotic and cause:
- diffuse microvascular thrombosis
- microangiopathic anemia
- thrombocytopenia
- vWf multimers are PRO-thrombotic and cause:
- acquired (auto-Ab) or hereditary
relationship between HbF and HbA
- HbF (alpha 2-gamma 2):
- high oxygen affinity
- made in final 7 mo
- –switches to–
- HbA (alpha 2-beta 2):
- during first 6 months of lide, switch to this
What drives angiogenesis?
- vascular endothelial GF (VEGF)
- stimulation angiogenesis in: nml, chronically inflammed, healing, or neoplastic tissue
- Fibroblast GF (FGF)
- FGF-2 involved in endothelial cell proliferation, migration and differentiation
- –and–
- embryonic development, hematopoiesis, wound repair
Lead Poisoning
A. peripheral blood smear
B. high risk groups
A. periph smear:
- coarse erythrocyte basophilic stipling
- microcytic hypochromic anemia
B. high risk groups:
- young kids ingesting paint chips (old, rundown buildings)
- industrial workers inhaling particulate lead
Aplastic Anemia
- low Hgb
- thrombocytopenia
- no hematopoietic cells in bone marrow
- compensatory: increase in circulating EPO
Iron Overload (Hemosiderosis)
- common, serious complication of chronic hemolytic anemia AND frequent blood transfusions
- *hemosiderin accumulation
- chelation therapy reduces parenchymal iron deposition
What is a patient with chronic hemolytic anemia predisposed to?
- folic acid deficiency
- macrocytic changes due to an increase in erythrocyte turnover
What is the relationship between Vitamin K and clotting?
- Vit K is needed for carboxylation and functionality of conjugation factors 2,7,9,10
- newborns without prophylactic supplementation are at risk for bleeding complications
- patients with CF are at risk for Vit K deficiency due to poor absorption of fat-soluble vitamins
Burkitt Lymphoma
- aggressive rapid growth
- strry sky microscopic appearance
- Path: translocation of c-myc oncogene on long arm of chromosome 8 with IgHC region on chromosome 14
- produces a nuclear phosphoprotein (c-myc) that functions as a transcription activator
- “african mccormick with a sharp jaw line wears a burkha under the starry night sky”
Follicular lymphoma
- tumor cells express pan B-cell antigens: CD19, 20, 21, 10 (…a)
- t(14:18); bCl2-IgH
- overexpression of bcl2 protein products inhibits apopotosis of tumor cells and facilitates neoplastic growth
Spleen’s Job (2)
- BLOOD FILTER-can remove circulating pathogens
- major site of OPSONIZING Ab synthesisi
- asplenic pts prone to infections cause by ncapsulating organisms:
- S. pneumo
- H. flu
- N. mening
- spleen=most commonly injured organ with blunt abdo trauma
T-cell ALL
- CP: mediastinal mass that…
- can compress great vessels=SVC syndrome
- can compress eophagus=dysphagia
- can compress trachea=dyspnea and stridor
Folate deficiency
- inhibits the formation of dTMP
- causes limited DNA synthesis
- promotes megaloblastosis and erythroid precursor cell apoptosis
- thymidine supplementation can moderately INC dTMP levels, so it can reduce erythroid precursor cell apoptosis
A. Aplastic anemia
B. In a sickle cell pt what is the most common VIRAL cause of an APLASTIC CRISIS?
A. AA causes pancytopenia; BM is replaced by fat cells and marrow stroma
**absence of splenomegaly on PE
BM biopsy useful in making diagnosis; marked hypocellularity
B. an infection of erythroid progenitor cells with parvovirus B19 (non envelpped, single-stranded, DNA virus) is the most common viral causes/infection
others: autoimmune, drugs (CARBAMAZEPINE, CHLORAMPHENICOL), exposure to radiation or toxins
Vitamin K
- needed for CARBOXYLATION and functionality of coagulation factors 2,7,9,10
- newborns without prophylactic supplementation are at risk for bleeding complications
- pts with cystic ibrosis are at risk for Vit K deficiency due to poor absorption of fat-soluble vitamins
A pt with chronic hemolytic anemia is predisposed to: (2)
- folic acid deficiency
- macrocytic changes due to increase in erythrocyte turnover
HgbC due to missense mutation
- glutamate is subsituted by lysine (if it were valine, would get HbS) in beta-chain
- causes a decrease in negative charge of Hgb
- speed of Hgb during gel electrophoresis:
- HgbA>HgbS>HgbC
Hereditary breast cancer
- most commonly associated with mutations in BRCA1 and 2 (tumor suppressor genes involved in DNA repair, mutations increase risk of developping breast and ovarian cancer)
- CP: peau d’orange=pitting edema in subcutaneous breast tissue and skin thickening around exaggerated hair follicles
Intravascular hemolytic anemia
- INCREASED: LDH and bilirubin
- DECREASED: serum haptoglobin
Hemolytic disease of the Newborn (erythroblastosis fetalis)
- cause: maternal sensitization to Rh antigens during a prior pregnancy with and Rh(D+) fetus
Pure red cell aplasia
- rare form of marrow failure
- sever hypoplasia of marrow erythroid elements in the setting of normal granulopoiesis and thrombopoiesis
- associated with:
- thymoma
- lymphocytic leukemias
- parvovirus B19 infection
Undifferentiated/Anaplastic Tumors
- do NOT resemble tissue of origin
- composition:
- pleomorphic cells with large hyperchromatic nuclei that grow in disorganized fashion
- may have numerous abnormla mitoses and giant tumor cells
Tumor Lysis Syndrome
- can develop during chemo from cancers with rapid cell turnover (poorly differentiated lymphomas and leukemias)
- substantial tumor burden
- high sensitivity to chemo
- CP:
- hyperphosphatemia
- hypocalcemia
- hyperkalemia
- hyperuricemia
RCC and blood d/o
- RCC can cause anemia of chronic dz and iron deficiency anemia d/t chronic hematuria
- some renal cell tumors can produce erythropoietin and cause polycythemia
- rare in younger pts
common paraneoplastic syndromes
- CP, frequently assoc neoplasms, etiology
- Cushing syndrome
- small cell lung cancer, pancreatic CA
- ectopic production of adenocorticotropic hormone/corticotropin-releasing hormone
- SIADH (syndrom of inapprop antidiuretic hormone secretion)
- small cell lung ca
- ectopic vasopressin production
- subacute cerebellar degeneration
- small cell lung ca
- breat, ovarian, and uterina ca
- anti-Yo anti-P/Q and anti-Hu Ab
- Lambert-Eaton myasthenic syndrome
- small cell lung ca
- voltage gate calcium channel ab
- Myasthenia gravis
- thymoma
- acetylcholine receptor Ab
- Hypercalcemia
- squamous cell lung ca
- ectopic production of parathyroid hormone-related protein
- dermatomyositis/polymyositis
- variable
- autoimmune
- erythrocytosis
- renal cell ca
- ectopic erythropoietin production
Paraneoplastic cerebellar degeneration
- CP:
- progressively worsening dizziness
- limb and truncal ataxia
- dysarthria
- visual disturbances
- etio: immune resp against tumor cells that cross reacts with Purkinje neuron Ag leadint to cute onset rapid degen of the cerebellum
Restless leg syndrome
- CP:
- uncomfortabe urge to move legs with:
- unpleasant sensations in the legs
- onset with inactivity or at night
- relief with movemet (stretching, walking)
- uncomfortabe urge to move legs with:
- Etio:
- idiopathic
- iron deficiency
- uremia
- diabetes (especially with neuropathy)
- MS, PD
- drugs (antidepressants, metoclopramide)
- Tx:
- avoidance of aggravating factors (alcohol, sleep deprivation)
- supportive measures:
- leg massage, exercise, heating pads
- dopamine agonists (Pramipexole)
Xeroderma pigmentosum
- AR due to decreased ability to repair DNA following damage by UV light
- skin is nml at birth
- CP:
- erythema
- scaling
- subsequent hyperpigmentation and lentigo formation on light-exposed areas (especially face)
- later:
- skin of affected area shows atrophy, telengiectasias, intermingling areas of hypo and hyper-pigmenations
- skin malignancies (SCC, BCC, malignant melanoma) develop as early as 5-6 yo
- Etio: genes that code for various DNA repair enzymes are abnml
- leads to defects in excision of abnml nucleotides or defects in replacement of nucleotides following excision
dz associated with impaired DNA repair
- xeroderma pigmentosum
- Fanconi anemia (AR, hypersensitivity to DNA cross-linking agents)
- Bloom syndrome (AR, hypersensitivity to UV damage and chemotherapeutic agents)
Great saphenous vein
- located superficially inthe leg, longest vein in the body
- accessed by surgeons in the medial leg (most commonly) or less commonly, near its pt of termination in the femoral triangle of the upper thigh
- femoral triangle:
- inguinal ligament superior
- sartorius muscle lateral
- adductor longus muscle medially
Femoral Triangle
consists of (lateral to medial; NAVL):
- femoral nerve
- femoral artery
- emoral vein
- deep inguinal nods/lymphatic vessels
Hereditary angioedema
- inherited AD condition
- low C1 esterase inhibitor activity leads to increases in bradykinin activity
- causes episodes of painless, non-pitting, well-circumscribed edema
- face, neck, lips, tongue most commonly affected
- can also be acquired-associated with ACEi tx
- DONT use ACEi with these pts!!
Failures of Embryologic processes
- proliferation=unilat aplasia of the fibula
- apoptosis=a.i. dz due to persistence of autorxv B/T cells
- obliteration=branchial cleft cyst
- migration=Hirschsprung dz-failure of migration of neural crest cells that form the colonic ganglion cells
- fusion=hypospadias (failure of urethral folds to fuse)
TGA (transposition of the great arteries)
- diagnostic: aorta lying anterior to and to the right of the pulm artery
- TGA results from failure of fetal aorticopulmonary septum to spiral normally during septation of the truncus arteriosus
- life-threatening cyanosis at birth
Anaphylactic shock
- charac: vasodilatation, increased vascular permeabilit, bronchoconstriction
- epinephrine counteracts these physiological mechanism, so is drug of choice for tx
Actinic keratosis (AK)
- develops on chronically sun-exposed areas of the skin in predisposed indivs
- lesions consist of erythematous papules with a central scale and a rough “sandpaper-like” texture
- considered pre malignant lesions and have the potential to progress to squamous cell carcinoma
Bacterial meningitis
- classic triad: fever, stiff neck, altered mentation
- eval: prompt blood cultures, empiric AB, lumbar puncture and CSF analysis to confirm the diagnosis, id the offending organism, and determine AB susceptibility
Kozak consensus sequence
- occurs on eukaryotic mRNA
- defined by the following sequence:
- (gcc)gccRccAUGG
- R=adenine or guanine
- sequence helps initiate translation at the methionine start codon (AUG)
Seborrheic keratosis (SK)
- benign epidermal tumor, presents as tan or brown, round lesion with well-demarcated border and “stuck-on” appearance
- epi: middle-aged/elderly
- rapid onset of numerous SK=undiagnosed internal malignancy (Leser-Trelat sign)
Acanthosis nigricans
- CP: hyperpigmented, velvety plaques found on axilla or neck (flexural areas)
- assoc with insulin-resistant states: DM, obesity, acromegaly and visceral malignancy, or an endocrinopathy
Lichen planus
- 5 P’s: polygonal, planar, pruritic, purplish plaques on wrists, hands, trunk, legs
- fine white lines: Wickham striae may be rpesent on plaque surface
patent foramen ovale (PFO)
- usually remains functionally closed b/c LA pressure>RA pressure
- most pts: asymptomatic
- BUT! conditions that raise RA pressure above LA pressure (Valsalva) can produce a transient R-to-L shunt across the PFO…may result in paradoxical embolization (stroke in the setting of venous thromboembolism)
Rb protein
- regulator of the G1–>S phase transition
- present in one of two forms:
- active-hypO-phosphorylated
- inactive-HYPER-phosphorylated
- cells are allowed to transition unchecked via proliferation signals which activate CDK4 (=hyperphos)
- resting cells in the G0 phase contain active (hypophosphorylated) Rb protein
[cutaneous] Angiosarcoma (Stewart-Treves syndrome)
- RF: chronic lymphedema (axillary LN dissection is a RF for CL involving ipsi arm)
- histo: infiltration of the dermis with slit-like abnml vascular spaces
- prognosis: poor b/c tumor is usually widespread by time of diag
viral meningitis
- elevated protein
- nml glucose
- lymphocytic predominance
bacterial meningitis
- low glucose
- high protein
- neutrophilic predominance of CSF
Leprosy (Hansen dz)
- deforming infection of skin and nerves
- caused by Mycobacterium leprae
- transmission: inhygienic conditions, respiratory route, prolonged skin-to-skin contact
- also armadillo contact
- range of clinical manifestations depends on strength of cell-mediated immune response
- TT (tuberculoid leprosy)=least severe form often self-limited; limited intact CMI (Th1)
- CP: mild skin plaques, hypopigmentation, hair follicle loss, focally decreased sensation
- LL (lepromatous leprosy)=most severe form, occurs in pts with a weak CMI (Th2)
- CP: skin thickening, plaque-like hypopigmentation (often with hair loss), leonine facies, paresis, regional anesthesia, testicular destruction, blindness
Melanoma
- most common metastatic tumors to the brain: lung ca, renal ca, melanoma
- malignancy of melanocytes
- embryologically derived from neural crest cells
- ABCDE
- Asymmetry
- border irregularities-uneven edges, pigment fading
- Color variegation-brown, tan, red, blk
- diameter > or =6mm
- evolving: lesion changing in size, shape, color, or new lesion
Mitochondrial encephalomyopathy
- neuromuscular lesions, ragged skeletal mu fibers, lactic acidosis
- mitochondrial d/o follow maternal inheritance pattern
- mit responsible for ATP production via oxidative phosphorylation, so defect=lactic acidosis, affect tissue with highest metab rates (neural tissue, muscular tissue)
- heteroplasmy=having different mitochondrial genomes within a single cell
- variable clinical expression in affected family members
Giant cell arteritis (GCA)
- pt with HA, visual and muscular s/s. enlarged temporal artery, elevated erythrocyte sedimentation rate
- Prog: cell-mediated immunity
- production of cytokines, in particular IL-6 closely correlates to severity of s/s
what is an important difference between unfractionated heparin and LMWH?
- they can both bind to anti-thrombin to INC its activity against Factor 10a
- only unfractionated can bind both anti-thrombin and thrombin to allow anti-thrombin to inactivate thrombin
*
paroxysmal nocturnal hemoglobinuria (PNH)
- d/t gene defect (acquired mut in PIGA gene)
- causes absence of GPI anchor (needed to attach CD55/DAF and CD59/MAC inhibitory protein)
- CD55 and CD59 help inactivate complement and prevent MAC from forming on nml cells
- leads to uncontrolled complement-mediated hemolysis
- classic triad:
- hemolytic anemia (hemoglobinuria)
- pancytopenia
- thrombosis (at atypical sites) <ie></ie>
- chronic hemolysis can cause iron deposition in the kidney (hemosiderosis)
high-affinity hemoglobinopathies
- high-O2-affinity hemoglobins have a DEC P50 that is represented by a leftward shift of the oxygen dissociation curve
- reduced ability to release oxygen within the peripheral tissues (selfish bastard dont want to let the O2 go!), leading to:
- renal hypoxia
- INC erythropoietin synthesis
- compensatory erythrocytosis
caseating granulomas of TB
- almost always contain large epitheliod macrophages
- pale pink ranular cytoplasm
- surface CD14 at periphery
- surround a central region of necrotic debris
Pol mutation
- responsible for acquired resistance to HIV reverse transcriptase inhibitors and HIV protease inhibitors
- ENV gene mutations enable escape from host neutralizing Ab
- (high mutability of HIV1 allows for evasion of host humoral and cellular immune responses and the development of resistance to anti-retroviral drugs)
superficial inguinal nodes
- all skin from the umbilicus down including the anus (below the dentate.pectinate line) drains to the superficial inguinal LN…except for:
- testes
- glans penis (drains into deep inguinal LN)
- (cutaneous) posterior calf (drains into depp inguinal LN)
lymph from the testes
- fro the testes to the abdominal para-aortic (retroperitoneal) LN (paralleling blood supply from the testicular arteries which arise directly from the abdominal aorta
ISONIAZID and sideroblastic anemia
- ISONIAZID inhibits pyridoxine phosphokinase (converts B6 to active form) =pyridoxine (Vit B6) deficiency
- Pyridoxine (B6) active form is the cofactor for <delta>amino-levulinate synthase [catalyzes the rate-limiting step of heme synthesis]
</delta><ul>
<li>inhibition of this step can result in sideroblastic anemia--microcytic hypochromic anemia</li>
</ul></delta> - this is why B6 is prescribed with ISONIAZID!
How is sideroblastic anemia diagnosed
- BM examination with Prussian blue stain
Warfarin-induced skin necrosis
- in pts with protein C or S (natural ANTI-coagulants) deficiency who are started on WARFARIN
- after the initiation of WARFARIN a rapid drop in factor 7 and protein C levels
- if there is already protein C deficiency, transien procoag/ANTIcoag imbalance is exaggerated=relative hypercoag state with thrombotic occlusion of the microvasculature and skin necrosis
acute intermittent porphyria
- AD condition
- PP: porphobilinogen deaminase deficiency
- S/S: most pts remain asymptomatic
- minority:
- acute attacks with:
- abdominal pain + vomiting
- peripheral neuropathy
- neuro-psych symptoms
- reddish-brown urine
- minority:
- tx: IV glucose or heme preparations (hemin)
- down regulate ALA synthase (rate-limiting enzyme in hepatic pathway of heme synthesis) activity
hereditary spherocytosis: epidemiology and CP
- epi:
- AD inheritance (approx 75%)
- N. euro descent
- CP:
- hemolytic anemia
- jaundice
- splenomegaly
hereditary spherocytosis: lab findings
- INC mean corpuscular Hgb concentration
- spherocytes on peripheral smear
- NEG Coombs test
- INC osmotic fragility on acidified glycerol lysis test
- d/t DEC SA:volume ratio
hereditary spherocytosis: tx and complications
- tx: splenectomy
- complications:
- pigmented gallstones
- aplastic crises f/m parvovirus B19 infection
hereditary spherocytosis: pathophys
- red cell cytoskeleton abnormalities
- mc: plasma-membrane scaffolding proteins: spectrin and ankyrin
- without the scaffolding, spherocytes are less deformable than nml RBCs and are prone to sequestration and subsequent accelerated destruction in the spleen
ALA synthase
- UPregulated by CYP450 inducers:
- most anti-epileptics
- griseofulvin
- rifampin
- DOWNregulated by heme and glucose
hereditary spherocytosis: complications
- pigmented gallstones
- aplastic crises from parvovirus B19 infection
Factor V Leiden
- 1-9% Caucasians worldwide are heterozygote carriers
- modified to resist activated Protein C
- resulting HYPER-coaguable state predisposes to DVT=source of MOST PE
- also: cerbebral vein thrombosis and recurrent preagnancy loss
- mc c/o inherited thrombophiia
What are the two main uses for DDAVP/vasopressin therapy
- mild hemophilia A and type 1 von Wilebrand dz
- INC circulating factor 7 (vWF non covalently attached, increases its stability) and endothelial secretion of vWF to stop bleeding
- central diabetes insipidus and nocturnal enuresis
- binds to V2R in renal tubular cells
- leads to:
- INC aquaporin chanels
- INC water reabsorption
- DEC urine output
Metalloproteinases and Invasion
- zinc-containing enzymes that degrade the ECM and basement membrane
- composed mostly of: laminin and collagens 4 and 7
- tissue remodeling and embryogenesis
- also: tumor invasion through the BM and connective tissue
Metalloproteinases and BM penetration
- tumor cells DETACH from surrounding cells (process determined by DECreased expression of adehesion molecules-E-cadherins)
- tumor cells ADHERE to the BM, facilitated by INC expression of laminin and otehr adhesion molecules
- tumor cells INVADE the BM via enhanced secretion of proteolytic enzymes (metalloproteinases, cathepsin D protease)
cytochrome c
- mitochondrial enzyme
- activates caspases
- indirecty brings about cell death through intrinsic pathway apoptosis
What are the two phases of apoptosis
- initiation phase (two diff pathways)
- protein-hydrolyzing caspases activated
- execution phase
- caspases bring about cell death by cleaving cellular proteins and activating DNAses
What are the two diff pathways of the initiation phase of apoptosis
- intrinsic (mitochondrial)
- extrinsic (death receptor)
Intrinsic (mitochondrial) pathway of stage 1-initiation of apoptosis
- mit more permeable and pro-apoptotic substances are released into the cytoplasm in resp to stress or the cessation of survival signals
- ANTI-apoptotic proteins (Bcl-2 and Bcl-x) that are in mit membranes and cytoplasm are replaced with PRO-apoptotic proteins (Bak, Bax, Bim)
- PRO-apop allow INC permeability of mit=release of caspase-activating substances: cytochrome c
extrinsic pathway of stage 1-initiation of apoptosis
- engagement of death receptors on the cell surface: TNFR1 and Fas (CD95)
- after cross linkage of Fas with its ligand mulecules of Fas come together and form binding site for a death-domain containing adaptor protein called FADD
- FADD binds an inctive form of a caspase…cascade
TTP clinical features
- new onset neuro symptoms
- hemolytic anemia with schistocytes
- INC LDH
- DEC haptoglobin
- thrombocytopenia
- INC bleeding time
- nml PT/PTT
- acute kidney injury
HbS
- d/t pt mut (valine at 6th position of beta chain for glutamic acid)
- abnl beta chain-polymerize when deoxy or dehydrated
- aggregates in the deoxygenated state!!
- plymers form fibrou strands that reduce RBC membrane flexibility and promote sickling
- under what conditions does sickling occur?
- conditions assoc w/ anoxia: low pH and HIGH 2,3-BPG
- inflexible erythrocytes predispose to microvascular occlusion and micro-infarcts
What is the classic triad of Wiskott-Aldrich syndrome?
- triad:
- eczema
- thrombocytopenia
- combined B-lymphocyte and T-lymphocyte deficiency
- dz onset is early in life
- CP: repeated infections, espec by encapsulated organisms
Calcium Chelation
- pts who receive the equivalent of more than one body blood volume (5-6L) of whole blood transfusions –or– packed RBC over a pd of 24 hrs may develop: elevated plasma levels of CITRATE
- CITRATE is a substance added to stored blood
- CITRATE chelates calcium and magnesium and may reduce their plasma levels=paresthesias
What is one of the mc causes of folate deficiency anemia
- ALCOHOLISM d/t:
- poor dietary intake
- impaired folate absorption, utilization, and enterohepatic recycling
- anemia within a few WEEKS
pathophys of folate deificiency
- reduced form of folic acid: tetrahydrofolic acid is necess for synthesis of AA, thymidine, and purine
- impaired nucleotide syn=defective DNA production in blood cell precursors=abnml cell division and megaloblastic hyperplasia of the BM
- peripheral blood smear: pancytopenia, hypersegmented neutrophils containing nuclei with >5 lobes
- RBC abnormalities: ovalocytosis and macrocytosis: MCV>100 nanom^3
paraneoplastic cachexia
- cachexia:
- anorexia
- malaise
- anemia
- weight loss
- generalized wasting d/t underlying systemic dz
- mediated by TNF-alpha (“cachectin”)
- along with IL-6 and IL-1beta
- how?
- suppresses appetite and INC BMR
myeloma and amyloidosis
- AL myloid forms d/t accumulation of monoclonal Ig LC
- apple green on Congo red
- contrib to renal failure in MM
- (also deposited in heart, tongue, nervous system)
malig EBV associations
- Hodgkins and NHL (Burkitt)
- nasopharyngeal carcinoma
Hydroxyurea MOA
- Hydroxyurea INC fetal Hg (Hb F) synthesis
- reserved for pts with frequent pain crises
*
MTX and Folinic acid (LEUCOVORIN)
- leucovorin can reverse the toxicity of MTX in non-cancerous cells in the GI mucosa and BM if administered at the approp time
- Leuco=reduced form of folic acid that does NOT require the action of DHFR
- when used in combo with 5-FU, Leucovorin potentiates the cytotoxic action of 5-FU (by binding thymidylate synthetase)
- frequently used in CRC therapy regimens
Beta thalassemia
- DEC beta globin chain synthesis=hypochromic, microcytic anemia (MCV<80)
- reduced beta glbin synthesis:
- membrane damage
- death of red cell precursors in BM (ineffective erythropoiesis)
- lysis of circulating erythrocytes (extravascular hemolysis)
Plummer-Vinson syndrome
- characterized by:
- dysphagia (esophageal web formation)
- iron deficiency anemia
- koilonychia (spoon-shaped nails)
- shiny red tongue
- most symptoms resolve with iron supplementation
what are cells commonly seen in beta-thalassemia
- small red cells with INC area of ctl pallor
- alsooo:
- anisopoikilocytosis (variation in size and shape)
- target cells
- teardrop cells
- nucleated red cell precursors
- basophilic stippling
Hemophilia lab findings
- PTT prolongation
- nml bleeding time and nml PT
- 8A and 9B (malibu and bitch neighbor)
Hemophilia A and B clinical features
- delayed/prolonged bleeding after mild trauma or procedure:
- hemathrosis. hemophilic arthropathy
- intramuscular hematomas
- GI or GU tract bleeding
von Willenbrand disease
- mc inherited bleeding d/o
- AD pattern of inheritance and variable penetrance
- absence of vWfactor=
- impaired platelet function (prolonged bleeding time)
- coagulation pathway abnormalities (d/t DEC factor 8 activity)–prolonged PTT)
How do you spot Plasmodium infection on a peripheral blood smear
- Giemsa staining
- RBC have multiple small rings (trophozoites) and banana-shaped gametocytes
Aspirin and NSAIDS reversible or nah
- Aspirin is a NSAID that IRREVERSIBLY inhibits COX1 and 2 via ACETYLATION
- other NSAIDS (diclofenac, ibuprofen, indomethacin) REVERSIBLY inhibit
telomerase
- RNA-dependent DNA polymerase that synthesizes telomeric DNA sequences that can replace lost chromosomal ends of the telomers
- cancer cells typically contain INC telomerase activity to allow for continued proliferation
Raltegravir
- integrase inhibitor
- disrupts the ability of dbl-stranded HIV DNA to integrate into the host cells chromosomes=prevent host cellular machinery from transcribing viral mRNA
what is the area postrema/chemorceptor trigger zone (CTZ)
- in the fourth ventricle
- area postrema has a CTZ
- it can respond to many NT, drugs, toxins
- sends info to nucleus tractus solitarius (NTS) in the medula
what are inputs for the NTS
- area postrema
- GI tract (via vagus)
- vestibular system
- CNS (meninges, hypothalamus)
where do neurons from the NTS project
other medullary nuclei and coordinate the vomiting process
what are the 5 main receptors that regulate the vomiting reflex
- M1 muscarinic
- D2 dopaminergic
- H1 histaminic
- 5-HT3 serotonergic
- neurokinin 1 (NK1) receptors
in pts with sickle cell anemia and other chronic hemolytic d/o what is the mc c/o an anaplastic crisis?
infection of erythroid progenitor cells with parvovirus B19 (a non-enveloped ssDNA virus)
motion sickness, hyper-emsis gravidarum (Promethazine)
- antimuscarnics (anticholinergics): scopolamine
- antihistamines:
- Diphenhydramine
- Meclizine
- Promethazine
dx for chemotherapy-induced emesis
- DA-R ANT-agonists:
- Prochlorperazine
- Metoclopramide
-
Seretonin (5-HT3)-R ANT-agonists
- Ondansetron
- Granisetron
- Neurokinin 1-R ANT-agonist
- Aprepitant
- Fosaprepitant
What is the mc c/o primary (hereditary) hemochromatosis?
- HFE protein mutations
- inactivation of the HFE protein results in DEC hepcidin synthesis by heptocytes anddd INC DMT1 expression by enterocytes (**hepatocytes detect falsely low iron levels)
- ^^^leads to–>iron overload
- pts at INC risk for:
- liver cirrhosis
- hepatocellular carcinoma
nml HFE function
- interacts with transferrin receptor to INC endocytosis of the iron-transferrin complex
- once inside cell, transferin degraded, released iron added to labile iron pool
- controls expression of proteins involved in iron absorption and storage
when do pts develop the classic triad of HFE protein mutations
- when body iron levels exceed 20g:
- micronodular cirrhosis
- diabetes mellitus
- skin pigmentation (bronze diabetes)
- at INC risk for: hepatocellular carcinoma, CHF, testicular atrophy/hypogonadism
what is the tx for cyanide poisoning?
- NITRITIES
- oxidizing agents
- induce methemoglobinemia
- methemoglobin contains ferric (Fe3+) instead of ferroUS (Fe2+)
- CN binds to ferric more avidly than to mitochondrial cytochrome c oxidase enzyme, thus diminishing cyanide’s toxic effect
s/s cyanide poisoning
- reddish skin discoloration
- tachypnea
- HA
- tachycardia
- NV
- confusion
- weakness
- can progress to seizures and CV collapse
- d/t inability of tissue to extract arterial oxgen:
- severe LA + narrowing of venous-arterial PO2 gradient
What is methemoglobin
- hemoglobin with ferric iron (Fe3+)
- incapable of carrying oxygen, BUT has high affinity for cyanide
- binds and sequesters CN in th blood=inhibit it from banging a/r with cytochrome oxidase=limits its toxic effects
what are three antidotes for cyanide poisoning
- **inhaled amyl nitrite
- hydroxycobalamin (Vit B12 precursor)
- sodium thiosulfate
What are anaplastic cells?
- neoplastic cells that demonstrate a complete lack of differentiation
What are the (FIVE) main features of anaplastic tumors?
- loss of cellpolarity with complete disruption of nml tissue architecture
- cells coalesce into sheets/islands in a disorganized/infiltrative way
- significant variation in:
- shape/size of cells (cellular pleomorphism)
- nuclei (nuclear pleomorphism)
- disproportionately large nuclei (high N:C ratio) that are often deep-staining (HYPER-chromatic) with abundant, coarsely-clumped chromatin and large nucleoli
- numerous, often abnml mitotic figures
- giant, multinucleated tumor cells
define metaplasia and give an example
- metaplasia=process of switching from one differentiated cell type to another
- often occurs in response to irritants (tobacco smoke, gastric acid)
- ex: bronchial epithelial cells undergoing phenotypuc switch from columnar epithelium to squamous epithelium
AML peripheral blood smear
- very large nucleated cells with scant cytoplasm…BLAST CELLS
- in the cells: linear, purple-red inclusions=AUER RODS
AML CP
- complications of PAN-cytopenia
- fatigue from anemia
- bruising/bleeding from thrombocytopenia
- infections from possible functional neutropenia despite leukocytosis
- median white blood ct: 15k mm^3 (nml: 4k-10k)
WBC differential from highest to lowest:
- neutrophils like M.E. better
- neutrophils: 55-60
- lymphocytes: 25-35
- monocytes: 5
- eosinophils: 2
- basophils: <1
What are five important neutrophil chemotactic agents?
- C5a
- IL-8
- LTB4
- kallikrein
- platelet-activating factor
HEME is a PORPHYRIN
- synthesized in the liver for use in the cytochrome p450 enzyme system AND in the BM for Hgb
- deficiency in any of the enzyme respondible for porphyrin synthesis can result in porphyria
- CP result from accumulation of porphyrin precursors in blood, tissues, urine
- AIP attakcs are d/t accumulation of ALA and PBG
what causes an accumulation of ALA
- ALA synthase induction, typically precipitated by:
- certain medications:
- Phenobarbital
- Griseofulvin
- Phenytoin
- alcohol use
- smoking
- progesterone (eg puberty)
- low-calorie diet
- certain medications:
(FOUR) necessary components of PCR
- primers that are complementary to regions fo DNA flanking the segment of interest
- thermostable DNA polymerase
- deoxynucleotide triphosphates
- source DNA template strand
three steps of DNApolymerase in PCR
- denature
- anneal
- elongation
which signal-transduction pathway is activated when growth factor binds to its receptors?
- PI3k/Akt/mTOR
- GF binds receptor tyrosine kinase
- auto-phosphorylation of specific tyrosine residues within the receptor
- phosphotyrosine residues activate PI3k which phosphoryltes PIP2 (located in plasma membrane) to PIP3
- activation of Akt (protein kinase B)
- Akt activates mTOR
- mTOR translocates to the nucleus and induces genes involved in:
- cell survival
- ANTI-apoptosis
- angiogenesis
- mTOR activation is inhibited by PTEN (tumor suppressor protein that removes the phosphate group from PIP3)
inositol phospholipid pathway
- uses Gq proteins that stimulate hydrolysis of membrane-bound phospholipids via phospholipase C
- pathway INC cytoplasmic Ca2+ levels through IP3-mediated Ca2+ efflux from the ER
what is the clinical presentation of hemolytic anemia
- anemia
- elevated LDH (lactate dehydrogenase)
- indirect HYPER-bilirubinemia
What is the difference between hereditary scperocytosis and autoimmune hemolytic anemia?
- similar findings:
- indirect HYPER-bilirubinemia
- elevated LDH
- spherocytes on peripheral blood smea
- difference with AIHA:
- NOT heritable
- positive direct antiglobulin (Coombs) test
- propensity to develop a.i dz (eg SLE)
What are triggers of G6PD deficiency
- drugs:
- sulfonaide
- antimalarials
- fava beans
- infectious:
- viral hepatitis
- pneumonia
- typhoid
pentose phosphate pathway (HMP shunt)
- generates:
- NADPH-for use in reductive rxns
- ribose-5-phosphate, precursor for synthesis of nucleotides
- two types ofr rxns: oxidative (IRREVERSIBLE) and nonoxidtive (reversible!!)
- NON-oxi:
- rib5P excess=glycolytic intermediates used for ATP generation
- rib5P low: pathway REVERSES, uses transketolase and transaldolase to convert glycolytic intermediates to rib5P!!
What is a major difference between direct factor 10a inhibitors and direct thrombin (2a) inhibitors
- 10a INC:
- NO EFFECT on thrombin time
- PT
- activated PTT
- 2a (thrombin) INC:
- thrombin time
isotype switching
- occurs in germinal centers of LN
- requires interaction of the CD40-R on B-cells with the CD40 ligand (CD154) expressed by activated T-cells
- IgG=main serum Ig of the secondary resp
negative selection
- deletio of T-cell clones that strongly bind to self-MHC antigens
- occurs in the fetal thymus and contributes to teh development of tolerance to one’s own antigens
When are mature B-cells exposed to antigens?
- when they leave the BM and migrate to lymphoid organs and peripheral tissues
- once activated, there are two pathways:
- short lived plasma cells that release Ag-specific IgM through a T-cell independent process
- most of them: migrate to lymphoid follicles in LN cortex, form GC (site of B-cell proliferation d/r immune response)
what are thalassemias
- disorders presenting with reduced -or- absent globin chain production
- almost all thalassemia cases result in hypO-crhomia and microcytosis (low MCV)
chronic alcoholics and megaloblastic macrocytic anemias
- nutritional deficiency of vit B12 or folate
- impaired synthesis of purine and pyrimidine bases
- aka diminished thymidine synthesis
where does heme synthesis occur
- partly in the mitochondria (first and final three steps) and cytoplasm
- heme in synthesized principally in:
- erythrocyte precursor cells (in BM)
- hepatocytes (use heme in microsomal cytochrome P450 system)
bony metastasis
- two characterizations:
- osteolytic (lucent)-d/t osteoCLAST stimulation=aggressive ca
- osetoblastic (sclerotic)-d/t osteoBLAST=more indolent course
- bony pain in older man with osetoBLASTic lesions on imaging=highly suspicious for prostate ca
- renal cell ca bone mets are commonly osteoLYTIC
- myreloma cells suppress osteoblasts would cause osteoLYTIC lesions
(FIVE) osteoLYTIC bone mets
(THREE) osteoBLASTIC
(TWO) mixed
- multiple myeloma
- non-small cell lung ca
- NHL
- RCC
- melanoma
- prostate ca
- small cell lung ca
- hodgkin
- GI
- breast
proto-oncogenes (1-hit GAIN of function)
-
RAS (GTP-binding protein)
- cholangiocarcinoma
- pancreatic adenocarcinoma
-
MYC (TF)
- burkitt lymphoma
-
ERBB1 (EGFR)
- lung adenocarcinoma
-
ERBB2 (HER2)
- breast cancer
-
ABL
- CML
-
BRAF
- hairy cell leukemia
- melanoma
tumor suppressor genes (2-hit LOSS of function)
-
BRCA1/2 (DNA repair genes)
- breast and ovarian ca
-
APC/beta-catenin (Wnt signaling pathway)
- colon, gastric, and pancreatic ca
- familial adenomatous polyposis (FAP)
-
TP53 (genomic stability)
- **most cancers**
- Li-Farumeni syndrome
-
RB (G1/S transition inhibitor)
- retinoblastoma
- osetosarcoma
-
WT1 (urogenital differentiation)
- Wilms tumor
-
VHL (ubiquitin ligase component)
- RCC
- VHL syndrome
tumor suppressor genes are involved in (FOUR) processes
- DNA repair
- cellular differentiation
- checkpoint control of the cell cycle
- transcription factor regulation
HEPCIDIN-acute phase reactant
- synthesized by LIVER
- acts as central regulator of iron homeostasis
- synthesis INC by:
- high iron levels
- inflamm conditions
- levels lowered by:
- hypoxia
- INC erythropoiesis
- influences body iron storage thru interaction with FERROPORTIN (TM protein, transfers intracellular iron to circulation)
- **upon binding hepcidin, ferro is internalized and degraded=
- DEC intestinal iron absorption
- inhibits release of iron by macrophages
8:14
Burkitt lymphoma (c-myc activation)
burke ATE 14 c nugs
9:22 Philly
CML (BCR-ABL)
brooke and abel got 9 camels when they turned 22
11:14
mantle cell lymphoma (cyclin D1 activation)
the clock on the mantle is lucky plus 3
14:18
follicular lymphoma (BCL-2 activation)
dbl 7 and 9
15:17
M3 type of AML
wizard AML started at 15, was an M3 by 17
GBM macro and micro
- mc primary brain neoplasm in adults
- macro:
- areas of necrosis and hemorrhage
- poorly demarcated from surrounding tissue
- micro:
- pseudopalisading necrosis (foci of necrosis surrounded by tumor cells)
- new vessel formation
- small round cells, bizarre giant cells, large number of mitoses
THREE common causes of acquired thrombocytopenia
- INC platelet consumption
- sequestration
- and/or destruction
ITP (immune thrombocytopenic purpura)
- a.i. destruction of platelets by anti-platelet Ab
- likely igG auto-Ab vs. platelet membrane glycoproteins GP2b/3a
- peripheral blood smear: isolated thrombocytopenia
- tx: systemic immunosuppression (corticosteroids)
- sometimes assoc w/ HIV or Hep C
OSA and secondary polycythemia
- OSA is characterized by recurrent episodes of asphyxia during slep
- peritubular cells in the renal cortex sense hypoxia and respond by releasing erythropoietin into the bloodstream
- deficient erythropoietin production is the reason many pts with CKD develop anemia
- erythropoietin stimulates erythrocyte production by binding to erythropoietin receptors on erythrocyte precursors in the BM=secondary polycythemia
cyclophosphamide and ifosfamide SE
- hemorrhagic cystitis
- caused by urinary excretion of toxic metabolite acrolein
- prevented by:
- aggressive hydration
- bladder irrigation
- admin of MESNA-sulfhydryl compound that binds acrolein in the urine
Iron deficiency secondary to menstrual blood loss-LABS
- DEC BM iron stores (ferritin and heosiderin LOW)
- DEC serum ferritin
- INC serum total iron binding capacity (TIBC)–reflecting INC serum transferrin
- DEC serum iron concentration
- DEC blood Hgb
- microcytic, hypO-chromic RBC
ferritin and transferrin
- ferritin:
- cellular iron storage protein
- marker of iron stores
- serum ferritin is DEC in iron deficiency, ELEVATED in iron overload
- acute phase reactant, may be elevated in pts with infections or inflamm dz
- transferrin
- transports iron through the plasma
- iron deficiency=make more transferrin
Whats so special about Type O moms
Ab are predom IgG–can cross placental and cause hemolysis in the fetus
All the directions of all the blots
- Northern: specific (m)RNA
- Southern: specific DNA in an unknown sample
- microarray-similer to south and north, involves hybridization of a large number of probes at once (genomic DNA or cDNA)
- Southwest: DNA-binding proteins
- Western: proteins
what is the correlation between half-lives and a transient hypercoaguable state
- occurs d/r first few days of warfarin therapy
- in addition to inhibiting Vit K-dependent clotting factors, warfarin also DEC carboxylation of Protein C and S
- C and S normally ANTI-coag through deactivation of factors 5 and 8
- Prot C has a short half-life=anti coag activity quickly reduced when warfarin therapy starts
- now have pro-coag form DEC protein C and pro-coag from persistent clotting factor 2,9,10
- tx: overlapping co-admin of heparin (heparin bridge)
DIC vs. TTP-HUS
- DIC:
- pts bleed
- coagulation cascade activated
- PT and PTT prolonged
- low fibrinogen and INC FDP
- TTP-HUS
- usually do NOT bleed
- only platelets are activated
- nml PT and PTT
- nml fibrinogen
What does the number of reticulocytes in the peipheral blood indicate
- indication of how effectively the BM is producing RBCs and thus responding to anemia
- low or nml retic ct in setting of anemia=underproduction anemia