Week 2 Flashcards
what are the 3 developmental processes of T and B lymphocytes?
rearrangement of their germline Ag receptor genes
selection of functional receptors
negative selection to eliminate self reactive clones
which are the polymeric and multimeric isotopes?
polymeric: IgM and IgA
monomeric: IgD, IgE, IgG
what are the brief functions of IgM, IgG and IgE?
IgM = classical pathway activation IgG= placental transfer IgE= high affinity binding to mast cells and basophils
definition of BCR
Ab bound to transmembrane proteins that allow a signal to be sent and the epitope interacts with Ag binding site on BCR
what are complementary determining regions?
part of the variable chain in Ig
hypervariable regions within Vh and Vl - determine Ag specificity
Ab bind antigens via amino acids in CDRs
which gene segments are involved in the heavy chain of Ig genes?
V, J, D gene segments
multiple C regions
which gene segments are involved in the light chain of Ig genes?
V and J gene segments
1 constant region
what are the enzymes involved in DNA recombination?
RAG-1 & RAG-2 recombinases, kinases and ligases
what is the order of somatic recombination in terms of heavy and light chains?
heavy chain rearrange first
light chains rearrange second
what are the functions of the V and C regions?
V region- Ag binding
C region - signal transduction; interacts with effector cells and molecules
describe Fab and Fc receptor and how they are cleaved?
fab: binds Ag and has 1 V region and 1 C region
Fc: involved in Ag recognition
both can be cleaved by papain
general function of IgM?
activation of classical pathway
which Ab is involved in placental activation?
IgG1
what is the order for somatic recombination in light chains?
V and J gene segments join - RNA splicing joins VJ to C region
what is the order for somatic recombination in heavy chain?
D and J gene segments join
then V segment joins DJ complex
VDJ is joined by C segments
where are germinal centres located?
within secondary lymph nodes
how are germinal centres formed?
after Ag activates B cell it receives help from CD4 helper T cells (Tfh) and together moves into the deep follicle of LT
what happens in germinal centers?
somatic hypermutation, IgG class switching, differentiation into plasma/ memory cells
time course of leukocyte migration (neutrophils/ monocytes)
neutrophils infiltrate in the first 6-24 hours
then replaced by monocytes 24-48 hours
brief points about vascular response to inflammation
increased microvascular permeability - plasma proteins move into extravascular tissue = increased blood viscosity and stasis
transudate vs excudate?
transudate = fluid pushed out into extravsacualr tissue due to increased HP excudate= fluid leaks out of capillaries due to inflammation
brief summary of cellular response of inflammation?
margination and rolling of leukocytes along endothelium
adhesion to the endothelium
transmigration out of the vessel between endothelial cell
migration into interstitial tissue toward a stimulus by chemotaxis
3 functions of leukocytes?
phagocytosis
release of substances that destroy EC microbes and sea tissue
production of mediators that amplify inflammatory response = more recruitment/ activation
what is D-dimer?
when fibrin degradation occurs D dimer results
indicates activation of fibrinolytic system
how does prevalence relate to predicted values?
low prevalence = low PPV and high NPV
high prevalence = high PPV and low NPV
goal of motivational interview?
make the patient themselves aware of the potential for change in behaviour resulting in improved health
3 components of motivation?
willing
able
ready
what does motivational interviewing help get rid of?
doubt and ambivalence
what theory does motivational interviewing use?
transtheoretical model
what are the 4 determinants of chronic disease?
social factors
behavioural factors
biological factors
environmental factors
trans theoretical model?
precontemplation contemplation preparation action maintenance relapse
indications for motivational interviewing?
SNAP risk factors medication adherence adherence to recommended screening and dx tests gambling pain management management of CD substance use disorder
what are the 5A’s?
ask assess advice assist arrange
Grace Model?
generate a gap - between patients current situation and what they want
roll with resistance - ambivalence is normal, alter strategy if there is resistance
avoid arguments - they increase resistance
can do attitude - encourage self efficacy and hope
express empathy - listen, communicate, acceptance/ support; gently persuade while respecting personal vie w
what is RULE? - in motivational interviewing
resist the righting reflex
understand your patients motivation
listen with empathy
empower your patient
what are the cell derived mediators in acute inflammation?
histamine cytokines chemokines leukotrienes prostaglandins platelet activating factor
what are the plasma derived mediators in acute inflammation?
complement
kinins
what mediators are involved in vasodilation?
PG, NO, histamine
what mediators are involved in increased vascular permeability?
histamine, 5HT, leukotrienes, C3a C5a, substance P, PAF, BK
what mediators are involved in chemotaxis, leukocyte recruitment and activation?
TNF, IL1, chemokine, C3a/C5a, leukotriene B4, bacterial products
what mediators are involved in fever?
PG, IL1, TNF
what mediators are involved in pain?
BK and PG
what mediators are involved in tissue damage?
lysosomal enzymes or leukocytes, ROS and NO
risk vs hazard?
hazard = inherit dangerousness risk = ability to cause harm
what are the types of risk?
individual community acute chronic primary secondary political/ reputational
what is risk mitigation?
the systematic reduction in the extent of exposure to a risk factor and the likelihood of its occurrence
what is risk perception impacted by?
trust origin control awareness age affected nature scope imagination uncertainty familiarity specificity personal impact fun/pleasure
risk matrices?
A risk matrix is a matrix that is used during risk assessment to define the level of risk by considering the category of probability or likelihood against the category of consequence severity. This is a simple mechanism to increase visibility of risks and assist management decision making.
prevention paradox and risk?
low chance of something happening in a large population
high chance of something happening in a small population
what does the C region on the AB bind?
Complement, FC receptor
involved in signal transduction
what Ig isotopes are involved in opsonization?
IgG1 works best for Ab binding to pathogen
IgM works best for complement binding to pathogen
which bacteria must be opsonized before phagocytosed?
Pyogenic bacteria such as Haemophilus influenzae, Streptococcus
pneumoniae, Streptococcus pyogenes and Staphylococcus aureus must
be opsonised before they are phagocytosed.
what substance do leukocytes secrete to help them cross the basement membrane?
collagenase
what is the course of leukocytes once they are outside the vessel?
leukocytes move to the site of infection by along a chemical gradient
they bind to specific cell surface receptors which trigger the assembly of cytoskeletal contractile elements necessary for movement
leukocytes move by extending pseudopods that pull cell in the direction of the extension
how do B cell tumours form?
malignant transformation of these cells by translocation of proto-oncogenes into the Ig loci
CLL, ALL, myeloma
what results from defective Ig gene rearrangement?
SCID, brutons TK def
what results from defective class switching?
hyperIgM
what are the 3 ‘rulers’ in motivational interviewing?
importance ruler
readiness ruler
confidence ruler
