How to analyse a scientific paper – preclinical Flashcards
What is the definition of preclinical
Of or relating to research conducted prior to direct experimental treatment or observation of human subjects
What is the key aspect of preclinical research
structure and function relationships
e.g. how enzymes change and there function changes with them
How is preclinical trial different from basic research
Different from basic research- translational
What does preclinical research involve
- Atom
- Molecule
- Organelle
- Cell
- Tissue
- Organ
- Organ system
How can DNA structure and function change
Chromosome abnormalities
SNP
GWAS/Whole exome sequencing
Histone modification - epigenetic - this is about modifying particular genes without changing the DNA sequence
Recombinant cells – change a cell be expressing a particular gene in the cell in order to find out what that protein does
Gene editing- CRISPR - gives control over what genes are expressed in a particular cell
How can you modify RNA expression
PCR
- RT-PCR - what genes are expressed in what particular cells
- qPCR - at which particular levels the genes are expressed
- RNAseq - like an Microarray, but very sensitive and broader dynamic range
Microarrays - what RNA strands are expressed between two different conditions
How do you look at protein structure and quantification
Measure using ELISA - often used in clinic to measure the expression of particular protein
Mass spectrometry
X-ray crystallography - gives an idea fo the structure of the protein and how much proteins are available
NMR - structure of the protien
Cryo-EM - Structure of the coronavirus was released using this - get the structure of a protein
How does an ELISA work
use a secondary antibody to bind the protein and once we bound that particular protein can use histological like detection processes to give an immunological or fluoresce change to measure how much protein you have,
- useful to measure a level of a cytokine
How do you look at protein function and expression
Receptors/ion channels/enzymes/transporters e.g. calcium assay (can open the calcium ion channel in the membrane of the cell and allow the entrance of calcium, the more calcium is in the cell the more active the G protein cover receptor is )
Find some way of measuring their activity
Usually measure substrates or products
- Can use ELISA
Common- inflammatory markers, cytokines etc
Products of enzymes can be measured
- Lipids
Determine rates of formation/depletion
- Finds out how badly damaged the enzymes are
How do you wokr out receptor function
Remember your FunMed pharmacodynamics lectures
Agonists, antagonists, potency, efficacy
Use of drugs to understand physiology
Does my drug work?
Drugs bind to (usually) proteins, and alter function
What does an agonist do
acts to replicate the effects of the endogenous ligands and try to replicate the activity of the natural ligand
What does an antagonist do
- prevents the activation of the receptor or molecule
What does an inverse agonist do
- has a negative efficacy below the baseline response
How can you measure potency
can measure the potency by making it radioactive and seeing how well it sticks to a receptor
What is the definition of efficacy
the ability to produce a desired or intended result.
