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86 terms

Heme/Onc

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How long do RBCs live?
120 days
What does Poikilocytosis mean?
Varying shapes of RBCs
What is contained in the dense granule of a platelet?
ADP calcium
What is contained in the alpha-granule of a platelet?
vWF, fibrinogen
What is the receptor for fibrinogen on a platelet?
GpIIb/IIIa
What is the receptor for vWF?
Gp1b
Petechiae are a sign for?
Thrombocytopenia
How long do platelets last?
8-10days
In infection, an increase in WBCs with bands (left shift) suggests what TYPE of infection?
extracellular bacteria
In infection, a granulocytosis suggests what TYPE of infection?
Fungus
In infection, a monocytosis suggests what TYPE of infection?
intracellular bacteria
In infection, an eosinophilia suggests what TYPE of infection?
Parasite
Monocytosis AND granulocytosis suggest what etiology of infection?
Viral
In what conditions do you see hypersegmetented polys?
vitamin B12 and folate deficiency
What enzyme is responsible for the green pus of neutrophils?
Myeloperoxidase
What is the role of lactoferrin?
binds iron and inhibits growth of phagocytosed bacteria and some fungi
Which blood cell has a kidney bean shaped nucleus?
monocyte, only in the blood, in the tissue they're macrophages
What cytokine is responsible for differentiation of monocytes?
gamma-interferon
What is the cell surface marker for macrophages?
CD14, CD40, also has MHC II and B7, Fc and C3b receptors which when activated enhance phagocytosis
What cell surface receptor of macrophages binds LPS?
CD14
What are the contents of an eosinophilic granule?
major basic protein, histaminase and arylsulfatase to limit the reaction
What are the contents of a basophilic granule?
histamine, heparin, vasoactive amines, leukotrienes (LTD4)
What are the contents of a mast cell granule?
histamine, heparin, eosinophil chemotactic factors.
Cell with metachromasia on giemsa stain and degranulation via cross linking of IgE?
Mast cell
Uncontrolled proliferation of mast cells causing itching, flushing, abdominal cramps, and PUD?
Systemic mastocytosis: PUD is from increased gastric acid from excessive histamine release
MOA of cromolyn sodium?
Prevents degranulation (mast cell membrane stabilizer)
What is the cell marker for suppressor T cells?
CD28
Can IgM cross the placenta?
No
Can IgG cross the placenta?
Yes
How do you preventerythroblastosis fetalis?
Rh antigen on RBC surface of fetus of mother who is Rh-, mother is exposed, makes anti-Rh IgG. THE NEXT PREGNANCY IS AT RISK. We treat using Rho(D) immune globulin (Rhogam) during first pregnancy to bind any spare Rh that might sensitize mom.
A deficiency of factor VIII gives you?
Hemophilia A
A deficiency of factor IX gives you?
Hemophilia B
Vitamin K is responsible for the gamma carboxylation of what factors?
2, 7, 9, 10, C, S
For acute blood loss and severe anemia, what type of blood transfusion do we use?
Packed RBCs, these increase Hb and O2 carrying capacity
To stop significant bleeding (thrombocytopenia, qualitative platelet defects) what type of blood transfusion do we use?
Platelets, these will increase the platelet count, usually given in a 6 pack of units or more for therapeutic effect
How do we treat DIC, cirrhosis, and warfarin-over-anticoagulation?
Fresh frozen plasma, which will increase coagulation factor levels by about 20%
How do we treat coagulation factor deficiencies involving fibrinogen and factor VIII?
Cryoprecipitate which contains fibrinogen, factor VIII, and factor XIII
Patient who was recently transfused has tingling in his fingers. What went wrong?
Citrate pretreatment of his transfusion binds calcium, hypocalemia
Lysis of RBCs in an old blood unit causes what electrolyte discrepancy?
Hyperkalemia: presents with peaked T waves, wide QRS and arrhythmias
Aplastic anemia is associated with what antibiotic?
Chloramphenicol
What is the MOA of Chloramphenicol?
Inhibits ribosomyl peptidyl transferase and blocks peptide bond formation at 50S
What do we use Chloramphenicol for?
Menigitis (H.flu, N. menigidis, S. pneumo) but not really because of it's side effects. Just keep in mind if patient with penicillin allergy comes in with aplastic anemia
Is Chloramphenicol induced aplastic anemia dose independent or dependent?
dose independent
Why do babies get grey baby syndrome?
Administration of chloramphenicol, they don't have UDP-glucuronyl transferase
Patient with fatigue, malaise, pallor, purpura, mucosal bleeding, petechiae after exposure to benzene?
Aplastic anemia: failure of myeloid stem cells
Causes of aplastic anemia?
radiation and drugs (benzene, chloramphenicol, alkylating agents, antimetabolites)
Viral agents (parvoB19, EBV, HIV, HCV)
Fanconi's anemia (DNA repair defect)
Idiopathic (immune mediated, primary stem cell defect) can follow hepatitis
How do you treat aplastic anemia?
Remove any offending exposure, allogenic bone marrow transplantation, RBC and platelet transfusions, G-CSF or GM-CSF:: complete recovery in less than 10% of all cases
MOA of methotrexate?
folic acid analog that inhibits dihydrofolate reductase
MOA of 5-FU?
Pyrimidine analog -> complexes w/ folic acid --> inhibits thymidylate synthase and decreases dTMP
MOA of 6-MP?
Purine analog --> decreases purine synthesis, but must be activated by HGPRTase
MOA of 6-TG?
Purine analog, but this one you can give with allopurinol as it is not metabolized by xanthine oxidase (6-MP)
MOA of Cytarabine?
Pyrimidine analog --> inhibits DNA polymerase
Which anticoagulant is associated with neutropenia?
Ticlopidine
What do you give for severe warfarin toxicity?
Fresh frozen plasma (if less severe, vitamin K supplement will suffice)
What drug do you use for long term prophylaxis against pulmonary embolism?
Warfarin
How do you treat von Willebrand's disease?
DDAVP (desmopressin) releases vWF stored in endothelium
PT monitors which pathway?
Extrinsic
PTT monitors which pathway?
Intrinsic
What conditions are caused by EBV?
Monospot positive mono, Hodgkin's lymphoma, Burkitts lymphoma, nasopharyngeal carcinoma, hairy leukoplakia, Lymphoepithelioma
What monoclonal antibody binds CD20?
Rituxumab
Most common cause of sepsis in sickle cell patients?
S. pnumoniae (followed by H. flu)
What is the triad of wiscott aldrich syndrome?
ezcema, recurrent infections and thrombocytopenia
What is the pathogenesis of wiscott aldrich syndrome?
XR- progressive deletion of B and T cells resulting in increased IgE, IgA, and decreased IgM (defective response to polysaccaride antigens)
What is the translocation in Burkitt's lymphoma?
t(8:14) moves the c-myc gene next to the heavy chain
What is the translocation in mantle cell lymphoma?
t(14:18) moves the bcl-2 gene closer the the heavy chain. bcl-2 inhibits apoptosis --> superduper dividing machine!
Describe the framework for Burkitt's lymphoma?
P: Adolescents or young adults, starry sky appearance, sheets of lymhocytes with interspersed macrophages, Jaw lesion in africa, abdomen/pelvic mass in sporadic form.
M: t(14:18) of the c-myc gene moves to the heavy Ig chain, associated with EBV
C: Leukemic phase rare, prognosis is rare, abdominal lesions can cause bowel obstruction, jaw lesions: loosening of teeth
Dx: PCR/Fish for c-myc, bone marrow biopsy, B markers (IgM)
Tx:CDOX regimen, rituxumab (monclonal against CD20)
Describe the framework for Diffuse large B-cell lymphoma?
P: Older males
Describe the framework for Follicular lymphoma?
P: Adults with painless adenopathy, waxing and waning in size (otherwise asymptomatic), associated with immunodeficiency, scanty cytoplasm with twisted nuclei that resemble germinal centers
M: t(14:18) bcl-2 translocation which is an anti-apoptotic gene, which when translocated next to the heavy chain, causes overexpression in B-cells and immortal cells
C: Difficult to cure, indolent course, 8-10 year survival waxing and waning
Dx: Lymph node biopsy, usually express Bcl-2
Tx:Radiation
Infant born with extensive extramedullary hematopoeisis, splenomegally, severe anemia, kernicterus. Dx?
Erythroblastosis fetalis from maternal type II sensitization to fetal Rh +, IgG can cross the placenta and destroy fetal RBCs
Ganciclovir and zidovudine increase the risk of what side effect?
Neutropenia
What do you administer for a DVT?
Warfarin is first line
What inhibits the Pt and the PTT but not the TT?
Direct factor Xa inhibitors: idraparinux, rivaroxaban, apixaban
Mutation to what receptor renders an individual resistant to HIV infection?
Homozygous mutation of CCR5 will make an individual resistant, heterzygotes have a slower course
Explain the binding of HIV to cells.
gp120 identifies the host T cell and binds CD4 and CCR5, gp 41 mediates fusion and entry.
How do you test for HIV?
Begin with ELISA (sensitive but has a high false positive rate), then confirm with western blot (specific, but has a high falses negative rate). We use PCR to monitor viral load.
Why might an HIV negative infant born to an HIV positive mother present with a positive ELISA?
gp120 can cross the placenta
What do you give an HIV positive mother to prevent transmission?
Zidovudine (Nucleotide reverse transcriptase inhibitor, causes megaloblastic anemia
Thymomas are associated with what conditions?
Myasthenia Gravis, pure red cell aplasia, Lambert-Eaton Syndrome
What conditions have schistocytes?
DIS, TTP-HUS, traumatic hemolysis
What conditions have spur cells (acanthocytes)?
Liver disease, abetalipoproteinemia
Which conditions have basophilic stippling?
Thalassemias, anemia of chronic disease, iron deficiency, lead poisoning
What condition has bite cells?
G6PD
What two conditions have spherocytes?
Spherocytosis and autoimmune hemolytic disease
What conditions have target cells?
HbC disease, Asplenia, liver disease, thalassemia
Which coagulation factor has the shortest half-life?
Factor 7, expect to see in alcoholics with liver failure since it's the first to go out. Easy though, since all the other ones don't impact the pT.
What do you see on peripheral smear for DIC?
Schistocytes: also seen in TTP.HUS, and traumatic hemolysis (heart valves)