Clinical Sciences Flashcards
X-linked recessive inheritance who is affected?
Males
Who transmits x-linked recessive disorders?
Heterozygote female carriers
What does the golgi add to proteins for trafficking to lysosomes?
Mannose-6-phosphate
What kind of disease is Gaucher’s?
Lysosomal storage disease
Enzyme replacement therapy for Gaucher’s?
IV Taliglucerase alfa
Function of RER?
- Translation and folding of new proteins
- Manufacture of lysosomal enzymes
- Site of N-glycosylation
- Examples of cells with extensive RER include pancreatic cells, goblet cells, plasma cells
Function of SER?
- Steroids, lipid synthesis
2. Examples of cells with extensive SER include those of the adrenal cortex, hepatocytes, testes, ovaries
Function of Golgi apparatus?
- Modifies, sorts and packages molecules that are destined for cell secretion
- Addition of mannose-6-phosphate to proteins designates transport to lysosome
Function of mitochondrion?
Aerobic respiration, contains mitochondrial genome as circular DNA
Function of nucleus?
DNA maintenance and RNA transcription
Function of lysosome?
Breakdown of large molecules such as proteins and polysaccharides
Function of nucleolus?
Ribosome production
Function of ribosome?
Translation of RNA into proteins
Function of peroxisome?
Catabolism of very long chain fatty acids and amino acids, results in the formation of hydrogen peroxide
Function of proteasome?
Along with the lysosomal pathway is involved in the degradation of protein molecules that have been tagged with ubiquitin
Which phase of the cell cycle determines cell cycle length?
G1 phase
Which phase of the cell cycle is influenced by p53?
G1
What is the cell cycle regulated by?
Proteins called cyclins which in turn control cyclin-dependent kinase enzymes
What is G0?
‘Resting’ phase, quiescent cells such as hepatocytes and more permanently resting cells such as neurones
What is G1?
- Gap 1, cells increase in size
- Determines length of cell cycle
- Under influence of p53
Regulatory proteins of G1?
- Cyclin D/CDK4
- Cyclin D/CDK6
- Cyclin E/CDK2 - regulates transition from G1 to S phase
What is S phase?
- Synthesis of DNA, RNA and histones
2. Centrosome duplication
Regulatory proteins of S phase?
Cyclin A/CDK2 - active in S phase
What is G2?
Cells continue to increase in size
Regulatory proteins of G2?
Cyclin B/CDK1 - regulates transition from G2 to M phase
What is M?
Mitosis, nuclear division, shortest phase of the cell cycle
What can funnel plots be used for?
To show publication bias in meta-analyses
How are funnel plots drawn?
Treatment effects on the horizontal axis and study size on the vertical axis
How does one interpret a funnel plot?
- A symmetrical, inverted funnel shape indicates that publication bias is unlikely
- An asymmetric funnel indicates a relationship between treatment effect and study size. This indicates either publication bias or a systematic difference between smaller and larger studies (small study effects)
What does a box and whisker plot show?
Graphical depiction of dataset quartiles, median and variability outside the upper and lower quartiles
What is a chi squared test for?
To determine if two independent groups differ from each other, it evaluates binary outcomes
What is a Kruskal-Wallis test?
A non-parametric test which compares the means of two or more independent groups
What is per-protocol analysis?
- Usually used to attempt to determine if a treatment has a biological effect
- It involves removal of participants from the data in a study who do not meet all the requirements of the protocol criteria for the study
2 types of cell division?
Mitosis and meiosis
Mitosis mushkies?
- Occurs in somatic cells
- Results in 2 diploid daughter cells
- Daughter cells are genetically identical to parent cell
Meiosis mushkies?
- Occurs in gametes
- Results in 4 haploid daughter cells
- Daughter cells contain one homologue of each chromosome pair and are therefore genetically different
What is a haploid cell?
Only have a single copy of each chromosome, e.g. gametes (ova and spermatozoa)
Phases of mitosis?
- Prophase
- Prometaphase
- Metaphase
- Anaphase
- Telophase
- Cytokinesis
Prophase?
Chromatin in the nucleus condenses
Prometaphase?
Nuclear membrane breaks down allowing the microtubules to attach to the chromosomes
Metaphase?
Chromosomes aligned at middle of the cell
Anaphase?
Paired chromosomes separate at the kinetochores and move to the opposite sides of the cell
Telophase?
Chromatids arrive at opposite poles of the cell
Cytokinesis?
Actin-myosin complex in the centre of the cell contacts resulting in it being \pinched’ into two daughter cells
