Etc. Flashcards
What T cell response plays a role in the pathogenesis of shock after the binding of a superantigen?
Secretion of cytokines
What is the most important protective function of IgM in an extracellular bacterial infection?
Complement activation
Upon rechallenge with a microbe, a person is protected from infection. What accounts for this?
Long-lived plasma cells are actively producing antibodies in the absence of antigen.
What is the mechanism by which immune complexes are cleared from circulation?
C3b solubilizes ICs and attaches to red blood cells via complement receptors
What is the most efficient class of antibody at activating complement?
IgM
Which cells are granulocytes?
Neutrophils
Eosinophils
Basophils
Dendritic cells play a vital role in activation of which cells?
T helper cells
Memory cells
B cells represent what percentage of total lymphocyte population?
25%
TH1 cells promote ______ and ________, or TH2 cells, which promote _____ and ______.
cytotoxic T cells / cell-mediated immunity
B cells / humoral immunity
Which antibody has a dimeric structure?
IgA
What are the functions of antibodies in extracellular infections?
- Neutralization of toxins
- Opsonization of pathogens
- Activation of complement
- Activation of effector cells
What is the humoral response dependent upon?
T helper cells activating B cells
Which cytokines secreted by CD4 cells promote B cell development?
IL-2
IL-4
IL-5
Which immune response is designed to fight intracellular infections and protozoans such as Plasmodium and Toxoplasma?
Cell-mediated immunity
What happens after a Th1 cell recognizes an antigen on MHC II of a B cell?
It activates the B cell by expressing CD40L (second signal) and secreting IFN-gamma. Once activated, the B cell/APC will ramp up production of NO and superoxides.
What are some intracellular fungi?
Histoplasma, Cryptococcus and Pneumocystis
What are some intracellular protozoa?
Toxoplasma
Leishmania
Plasmodium
Which cytokine activates Th1 cells and NK cells?
IL-12
Second degree sunburn
Necrotic epidermis
Dermal hyperemia
Third degree sunburn
Necrosis of dermis AND epidermis
Fluid loss
Is Imatinib specific for the Bcr-Abl oncogene product?
Imatinib is a low-molecular-weight competitive inhibitor of the ATP binding site of Bcr-Abl, c-Abl, platelet-derived growth factor receptor (PDGFRa and b), and c-Kit; hence it is NOT absolutely specific for the Bcr-Abl oncogene product.
In 532 chronic phase CML patients in whom interferon treatment had failed, what percentage obtained a hematologic complete response?
95% obtained a hematologic complete response, with only 9% relapse after a median follow-up of 18 months
Cytarabine mechanism
2’-deoxycytidine analog;
phosphorylated to aracytidine triphosphate;
2’-hydroxyl trans to 3’-hydroxyl hinders rotation of base and inhibits DNA chain elongation
Inhibits DNA polymerase
Cytarabine toxicity
Bone marrow depression
