Trigger 3 Flashcards
What is hypertrophic cardiomyopathy?
overgrowth of the heart muscle and thickening of the spetum
result in smaller chambers
How is it caused?
some hypertrophy occurs with cardiovascular exercise
Genetic disease causing mutations in the proteins of the sarcomere
What type of mutations occur in the proteins
42% occur in cardiac myosin binding protein C
40% occur in cardiac beta myosin heavy chain
What is Arrhythmogenic right ventricular cardimyopthy
enlargement of the right ventricle
disease of the desomosomes proteins
what are the stages of ARVC
Concealed - small change in right ventricle
Overt - noticable structural changes in the heart muscle, affecting pumping action and cause abnormal rhythms
Weakening - right ventricle becomes stretched, pumping weaker
left ventricle also affected
What are cardiomyocyte intercalacted discs
structures that connect the myosites together
what are cardiomyocyte intercalacted discs made up of
Desmosomes
Gap junctions
Adhere Junctions
What are Desmosomes
structure that holds cells together
made up of proteins
gives structural intergrity
link to intermediate filament cytoskeleton
Gap junctions
form direct pores between myocytes
continous electrical and metabolic connection between the cells
allows them to contract together
made of kenxin
Adhere junctions
anchors thin filament of the sacromere to the sarcolemma
describe direct immunohistochemistry
slice tissue using a chiroscat and fix in formalin
Insert primary antibodies which are against the antigen/protein of interest
Label antibody with reporting system - enzyme or flourscent congulated to antibody
Benefits of direct method
specific
quciker
disadvantage of direct
only one antibody for each protein
more expensive
describe indirect immunohistochemistry
slice tissue using a chiroscat and fix in formalin
Insert primary antibodies which are against the antigen/protien of intrest
Insert secondary antiobies which ahve been raised in another species against original IGg antibody
secondary antibody is coagulated to reporting system
Benfits of indirect method
sensitive can bind to more reporter antiobodies can bind more than one 2nd antibody to each 1st antibody allows applicfication useful when antigen is in low abundance
Disadvantage of indirect method
slower
can get non specific binding
steps of immunohistochemistry
slice tissue and fix slides in formalin 10 minutes
Block slide in serum, stops non-specific binding when you add antibodies later 30min - 1 hr
Wash in saline, removes anything that is not bound to tissue
Incubate with pirmary antibody 30min- 2hr
Wash
Incubate with secondary antibody 30min - 2hr
Enzymatic detection - Reveale antigen
What is pentrance
is the probabilty that a person carrying a diseas-assocaited genotype will develop that disease whithin a give time period
pentrance calcualtion
no. individuals displaying conditions/ no. with the mutation x 100
What is incomplete/reduced penetrance
when it has been demostrated that individauls who possess a disease associated genotype show absolutley no manifestion of that condition
- number of individuals who display the condition is less than those who carry
What is complete pentrance
if a person carrying a disease assocaited genotype always develops the condition
-number of individuals who display clinical features of the condition is equal to those who carry the mutaution
What is cost-effcetive analysis
cost of health care related to the net outcomes
assigns a value to the outcome
meaured in £ per life year saved
uses QALYs
what is cost benefit analysis
rescourse cost relative to the possible medical benefit
effectiveness measured in £
why does a myocyte action potential have a plateau
due to the inflow of Ca2+ through L-type channels
describe the myoctye exctiation contraction
AP deploarises membrane
Ca2+ flow through voltage gated channels
depolaristation of dihydropyridine receptor causing transformatonal change of L type channel
causes ryanodine receptor to open
CA2+ unbinds from calsequestin and pours into intracellular space
binds to troponin C
cross bridge cycling
order of heart muscle
Endothelium -lines inside of ventricles, thin Myocardium -thickest layer Pericardium -outside layer -visercal and partietal pericardium
What are GPCRS
membrane bound plasma proteins that couple hormone receptors to effector enzymes
7 transmemebrane domains
Describe the steps of the adenyly cylase mechanism
Hormones binds to receptor on membrane, cause conformational changes of the alpha s subunit
GDP released, GTP binds
Alpha subunit detaches
Alpha s -GTP complex migrates and binds to adenylyl cylase
activated adenylyl cyclase catalyses conversions of ATP to cAMP
cAMP activates protein kinase A
phosphorylates intracellular proteins
Describe steps of smooth muscle signalling
Hormone binds to receptor on membrane, cause conformational changes of the alpha q subunit
GDP released, GTP binds
Alpha subunit detaches
Alpha q -GTP complex migrates and binds to phopsplipase C
activated phospgolipase C, catalyses the liberation DAG and IP3 from PIP2
IP3 causes the release of Ca2+ from intracellular stores in the ER/SR
Ca2+ and DAG activate Protein Kinase C
CA2+ binds to calmodlin, activating MLC kinase
Kinase phosphorlyates light chain of myosin
ATP –> ADP
contraction
What does the Gq-R vasopressin cause
vasoconstriction
What does the Gs-R adrenaline cause
Vasodilation
What does the Gi-R adrenalin/noradrenline cause
vasoconstriction
Function of Gs
activates adenylyl cylase, increase cAMP
activates PKA, phophorylates downstream target prtoeins
Examples of Gs
beta adrenoceptor
Function of Gi
inhibits adenylate cyclase, decrease cAMP
Examples of Gi
muscarinic AChR
Function of Gq
activates phospholipase C, increase IP3, Ca2+, DAG
PKC activation, phosphorylates downstream proteins
Examples of Gq
muscarinic AChR
What is diagnostic sensitivty
% of patients with disease correctly test positive for disease
true positive/ true positive + false negative
What is diagnostic specificty
% of healthy people who have a negative test
true neagtive/ true negative + fasle positive
describe the vector preparation satge of recombinant dna technology
create an insertion site by restriction digestion
dephosphorylation of the vector may be necessary to prevent self-ligation
alkaline phosphate removes the 5’ phosphate groups, prevents self-ligation
describe the insert preparation satge of recombinant dna technology
perform restriction digestion to generate compatiable ends from subsequent slicing into the vector
the desired fragement can be purtified by running on agrose
describe the ligation preparation satge of recombinant dna technology
joining of vector and insert common enzymes (T4DNA ligase) links DNA ends between 5' phosphate ans 3' OH group
describe the tranformation preparation satge of recombinant dna technology
naturally occruing process in which bacterial cells take up foreign DNA at a low frequency
describe the colony screnning satge of recombinant dna technology
the transformational reaction contains a mix of cells with no vector, the vector with no insert, the insert alone and succesful vector and insert
bacteria without the vecor will not grow, where as bacteria with will grow due to anitbiotic resistance
What is recombinant dna technology
joining together of DNA molecules from two different species that are inserted into a host organism to produce new genetic combinations that are of value to science, medicine, agriculture, and industry.
