Dogging Sepsis
Veterinarian Cynthia Otto: Tracking Immune Response Gone Haywire
Cynthia Otto Stalks Sepsis
Veterinarian Otto traces the cellular origins of sepsis.
Sepsis
Is a full-body reaction to injury or illness
Arises unpredictably
May result from blasts of nitric oxide (NO)
Question:
Is NO always harmful to humans?
Photo: Sabina Louise Pierce
Answer: No
NO is full of possibility
Normal Immune Response
Haywire Immune Response:
NO Way Out Hypothesis
Garage Gadget Tests Hypothesis
FCCC system
Controls and measures the amount of oxygen that passes over cells
Testing the link between hypoxia and NO production
FCCC delivers normal, low, or fluctuating levels of oxygen to cells
Researchers measure NO and iNOS levels in the cells
Results suggest intermittent hypoxia can cause inflammation
Forced-convection cell-culture system
(FCCC)
Photo: Alisa Zapp Machalek
Take a Breath
When you breathe, oxygen travels
Through branched passageways in your lungs (blue)
Through alveoli (yellow)
Into blood vessels (red)
Copyright Dennis Kunkel Microscopy, Inc.
Battle to Breathe
Animal Models for Human Conditions
Patient in intensive care unit on a ventilator
Otto used anesthetized rabbits to study how ventilators affect alveoli in the collapsed lungs of humans
Photo: Chris Gregerson
Findings: Otto's Rabbit Experiment
Oxygen levels fluctuated wildly in the ventilated, anesthetized rabbit.
The alveoli snapped open and closed with each pump of the ventilator.
The breathing machine could not maintain the inflated, semi-full structure typical of alveoli in healthy animals or people.
The continual stress of expanding and deflating alveoli appears to wear them out.
Ventilators may damage lungs by eroding their cellular fabric.
Research Applications
How might Otto's research of hypoxia and ventilator-associated lung damage be applied to the care of patients who suffer trauma or severe infection?