Question: You’re working at the medical
examiner’s office at San
Francisco County Hospital. It has been a p…
You’re working at the medical
examiner’s office at San
Francisco County Hospital. It has been a particularly light
day,
with only one homicide and a dead chipmunk that you checked over
for rabies. The chipmunk didn’t have rabies, and you’re ready to go
home. Just as you’re flipping the switch, you get a call from your
secretary. “Francesca,” he says. “We’ve got a dead kid up here that
you’ll want to look at right away. Might be foul play.”
Thinking of your four-year old daughter at home, you grimace.
“OK, John, I’m heading to the morgue.” Performing autopsies on kids
is the least favorite part of your job. But you are paid to solve
medical mysteries, and it looks like you’ve got one here…
In the morgue, you find the report from the hospital. Glancing
over it, you notice a narrative of the girl’s last hours and read
it carefully:
At 10 am, mother returns from the store to find girl
vomiting. Not feeling well, and sleepy. Mother put girl to bed. Ten
minutes later, she noticed that the child’s breathing was irregular
and slow. She tried to wake her daughter, but was not able to do
so. The child became comatose. At noon, the girl was admitted to
the hospital, with no heartbeat or spontaneous breathing.
After collecting the samples you need from the body, you send
them off to the clinical laboratory scientists for analysis. A week
later you get the report below back…
• The girl died within two hours of first vomiting.
• Tissues sections from lung, heart, & kidneys show massive
cell death.
• Staining with cellular dyes indicates that the mitochondria
within the affected tissues were damaged.
• More detailed analysis of heart cells showed that ATP levels were
reduced in the mitochondria.
• ATP levels in the cytoplasm of these cells, however, were
normal.
• In addition, Acetyl-CoA molecule levels were normal.
• Using a new chromatographic technology developed last year, the
lab was able to determine levels of various sub-cellular components
in the heart cells. Highlights from that report are listed
below:
Metabolite Autopsy Finding: Glucose 102 μmol, Pyruvate 23 μmol,
NAD+ 6 μmol, NADH 383
μmol
Normal Levels: Glucose 100 μmol,
Pyruvate 25 μmol, NAD+ 75
μmol, NADH 50 μmol
You suspect that the girl may have somehow been poisoned and
ingested a chemical called: Cyanide
1) What effects does cyanide have on the four processes of
cellular respiration?
2) Would cyanide likely produce the autopsy report results
described above?
3) How would a young person come into contact with such a
chemical?
4) Does cyanide assert or refute the idea that this chemical
could be resposible for the mysterious death?
