medical-notes/content/Vetenskaplig artikel/Methods & Main Results.md

Modell/material

• 197 hematologically normal females
  • 23 new born
  • 94 young adult (median 30)
  • 80 eldery (over 75)
• purified neutrofils
• purified T-cells

The model is human hematopoiesis across age and the material is lineage-purified blood cells

methods:

1. cell separation (neutrofil and T-cell)
2. x-chromosome inactivation analysis (humana PCR)
3. T-cell clonality check

Note

They separated neutrophils and T cells, measured X-inactivation skewing, and checked that T-cells were not dominating.

What was compared / tested

• Age groups: newborn vs young adults vs elderly
• Cell lineages: neutrophils vs T cells
• Readout: degree of X-chromosome inactivation skewing

Results

1. X chromosome usage is similar in newborns and young adults.
2. Neutrophils from elderly individuals show strongly uneven X chromosome usage.
3. T-cells show much less uneven X chromosome usage and no dominant clonal expansion

Figure

!image-183.png Notes

• This graph shows the distribution of X chromosome usage in 23 newborn females
• X-axis: in % how uneven the X chromosome usage is
  • 50% means perfectly (50% maternal / 50% paternal)
  • 0/100% means all cells use the same chromosome
• Y-axis: number of individuals in each group

Conclusion:

• Newborns mostly show balanced use of the two X chromosomes.

!image-184.png Notes

• This graph shows the purified neutrofils from 80 elderly (y >= 75) females

Fig 1. Distribution of X-chromosome inactivation patterns from peripheral blood of haematologically normal females in three different age groups