How Medicine Holds Keys for Conservation
Transcriber: Lauren Hill
Reviewer: Amanda Zhu
If you’ve ever had an X-ray, ultrasound,
CT or MRI performed,
you may have experienced
the unique feeling
of looking at your body from the inside.
It’s so strange to see a part of yourself
that you’re both intimately familiar with
and yet have never seen.
Those images are created
with a variety of techniques
using sound waves
and radiation and magnets.
But for simplicity’s sake,
let’s envision them each as tiny pixels
that come together to give us a picture
that gives us a deeper meaning
about our bodies.
These images are not
just for human bodies.
They’re also revolutionizing conservation.
I’m a marine mammal veterinarian,
and you and I are going to follow
the path of a pixel
to see how this work is changing the way
that we treat wildlife
and care for our natural world.
Let’s start in California
in the United States
with a sea lion named Cronutt.
Cronutt suffered brain damage
and developed epilepsy
after being exposed to domoic acid,
which is a biotoxin that’s
naturally produced by marine algae.
Toxin producing algal blooms are becoming
more frequent and more persistent
as our ocean warms from climate change,
affecting both mammals like Cronutt
and humans alike.
After multiple attempts at rehabilitation
and clearly unable
to survive on his own in the wild,
Cronutt went to live
at Six Flags Discovery Kingdom,
where they managed his epilepsy
with medication.
Our brains have nerve cells, or neurons.
Some excite and others inhibit or calm.
In certain forms of epilepsy,
the inhibitory neurons are lost,
leading to the over-stimulated
electrical activity of a seizure.
The pixels in MRI images can show us
where damage has occurred,
where neurons are active,
and even how different regions
of the brain connects with one another.
Dr. Scott Baraban’s lab
at the University
of California, San Francisco
has been researching
a new cell transplant therapy.
He uses specialized cells
that will turn into interneurons
to replace the damaged cells
with healthy ones.
These special cells integrate
into the circuitry of the brain
and restore the calming function,
effectively rewiring the brain
and stopping seizures.
Over time, Cronutt’s seizures
and behavior changes got worse,
and he was near death last year.
He needed one last shot.
An interdisciplinary team
of 27 specialists
from both the veterinary
and human medical fields came together.
We used both CT and MRI
to highlight the portion of his brain
called the hippocampus, which is shown
in the MRI image on the left,
outlined in the red box.
These images guided neurosurgeons
with a specially tailored needle
to deposit the cells
directly into the damaged site.
Last October,
Cronutt became the first sea lion ever
to receive an interneuron transplant.
And eight months later,
we’re cautiously optimistic
as he remains seizure-free.
Let’s next follow the path of a pixel
to Valencia, Spain.
Dr. Daniel Garcia leads
the veterinary team at Oceanographic,
where they rehabilitate
stranded sea turtles.
Many of these turtles are bycaught,
entangled in trawling nets
and dragged up from the depths.
Dr. Garcia’s team discovered by accident
while treating turtle patients
that sea turtles
can get decompression sickness,
or “the bends,”
when nitrogen bubbles out of the blood
during a rapid ascent to the surface.
We used to think that sea turtles
couldn’t get the bends,
because of unique adaptations
in their anatomy, physiology and behavior.
These animals can stay underwater
for up to seven hours at a time
without getting decompression sickness.
So what makes bycaught turtles different?
But bycaught turtles
are examined around the world,
and these bubbles
hadn’t been noted before,
Dr Garcia’s team made the discovery
thanks to collaborations.
First, they developed
strong collaborations
with the fisherman who were
accidentally catching the turtles.
Instead of looking for bubbles
inside of a long dead turtles,
the fishermen gave the team
almost immediate access to live turtles
directly after they were caught.
The fishermen also gave
detailed observations
describing a certain group of turtles
that seemed fine but would later die
several hours after being admitted
for rehabilitation.
The team also collaborated
with human physicians
to discover the disease.
They use CT to pinpoint the gas bubbles
and discover the damaged
tissue around them.
This CT image of the body of a sea turtle
shows the lighter areas that are gas
throughout the body of a turtle.
And these aren’t just tiny micro bubbles.
I want you to fill your mouth up with air
and really puff your cheeks out.
That’s the total volume of nitrogen gas
that might be found
inside the body of a turtle,
bubbles blocking blood vessels
and cutting off oxygen
to the brain, heart and beyond.
The team also discovered
a key to treatment.
Like the treatment for humans,
gas bubbles can diffuse
back into the blood
if the body’s re-pressurized.
They first developed
a crude decompression chamber
out of an autoclave.
And the result is just how I would imagine
we would send a sea turtle to space.
Over a decade, the team and the clinic
refined their techniques
to include a full-size hyperbaric chamber
that was originally designed to treat
human scuba divers with the bends.
And now the rate of recovery and release
for animals that arrive
at the clinic alive
is now 95 percent successful.
These advanced imaging techniques
are also revolutionizing
marine mammal medicine in Hong Kong.
Dr. Brian Cot, originally trained
as a diagnostic radiographer,
learning his expertise
in imaging, like CT and MRI,
that was originally designed
to treat human patients,
He recognized that the value
could be applied
to marine animals as well.
And he now leads the virtopsy,
or virtual autopsy, project,
with the cetacean stranding
response program in Hong Kong.
A body that washes up, dead on the beach,
can still provide a wealth of information.
Post-mortem exams
typically open the carcass
and examine the organs
in a systematic way.
It’s a treasure hunt,
and important things can be missed,
particularly if the body
is very decomposed.
Virtopsy combines CT and MRI
to give a guide to pathologists
before they even start their exam,
which improves their accuracy.
Tiny lesions that might have been missed
with routine sampling
are pinpointed for a thorough exam.
Two-dimensional images
can be combined into 3D renderings.
These groups of pixels
are particularly effective
for identifying lesions in bone
or gas bubbles like we saw
in the turtles in Valencia
or identifying trauma to organs,
and it’s safer.
Because the carcasses are neatly wrapped,
the risk to rescuers of catching
a zoonotic disease spread from an animal
is much lower.
Dr. Cot is based at
the City University of Hong Kong,
and his team includes both human
and veterinary radiologists,
veterinarians, technicians
and pathologists.
The project is a collaboration
between government, academia,
aquaria and non-governmental foundations.
Over the past six years,
240 marine animals were stranded
along Hong Kong waters,
and virtopsy was performed
on 74 percent of them.
That’s virtually every animal
that could be safely retrieved.
All of this incredible work
is happening simultaneously
all around the world.
All of it includes advanced imaging
that we couldn’t have
imagined a century ago
to peer deep within the body.
And it’s happening
while the threats we face
and our collective
human impact on the world
is accelerating.
I’m often asked, “Why?”
Why spend the money or the resources
to treat a single sea lion
or rehabilitate a few sea turtles?
I’m a veterinarian,
and I took an oath
to improve individual animal welfare
and relieve suffering.
And for Cronutt and those sea turtles,
these procedures saved their lives
and made all the difference.
But some critics say
that treating individual animals
is not enough,
and they’re absolutely right,
that in the big picture,
the individual impact is minimal.
When we’re tackling
the big conservation issues we face,
treating single animals
should be our last resort.
It’s not realistic on a large scale.
Brain surgery will not be the answer
for the majority
of brain damaged wild sea lions.
Decompression chambers won’t be the option
for the majority of bycaught sea turtles.
Few of the animals
that strand around the world
will pass through a CT
before their body is examined,
and the majority
will never be examined at all.
If we base our actions
only on the patients in front of us
and on our individual impact,
then that impact will remain minimal.
We have to think of our actions
outside of the scope of individual impact
and larger than ourselves.
Consider all of the ways that this work
does help more animals
and different species.
A first example is that sea lions,
like Cronutt, are helping humans today
and will continue
to help them in the future.
Biotoxins, like domoic acid,
are a growing threat
to both human and animal health.
They are a key example
of the direct effect that climate change
is having on our health.
And decades of research
on domoic acid in sea lions
has led to collaborations
where the public health department
uses reports of seizing sea lions
to better target their toxin sampling
and protect human health.
Cronutt himself is charismatic,
and his story may bring a glimmer of hope
to someone with a pet
or a loved one with epilepsy.
His procedure can be refined
to help other sea lions.
And although not a reality today,
treating Cronutt advances
this type of cell transplant therapy
towards one day helping humans
with incurable epilepsy.
A second example
is that complex discoveries
can lead to accessible
conservation solutions.
Discovering decompression
sickness in turtles
gave us direct clues on how to minimize
the disease’s effects -
no CT or decompression chamber needed.
We learned that if trawling times
are less than an hour,
the risk of decompression
sickness is very small.
If turtle excluder devices are used,
the risk is very small.
These devices allow turtles
to exit trawling nets
through a specialized escape hatch.
And for parts of the world
where rehabilitation is not an option,
releasing otherwise unharmed animals
back into the water as quickly as possible
may help the animals
to naturally decompress themselves.
Discovering decompression sickness
required complex tools,
but the solutions that arose
are accessible for all.
A third example is that this type of work
is leading to direct conservation support
around the world.
As our technology advances,
we have an even larger responsibility
to use it for the benefit of all.
Virtopsy makes exams easier,
faster and safer,
and it stores massive amounts of pixels.
These images preserve
the exam indefinitely.
Now reaching out across the world
for a second opinion
becomes possible and easier;
studies, over time, become more robust.
Imagine the difference between studying
a three-dimensional image like this one
compared with studying
a photograph of a bone.
Two vulnerable Indo-Pacific species
live in Hong Kong waters,
the finless porpoise
and the humpback dolphin.
For finless porpoise,
relatively little is known
about this species
in regions such as India
or the Persian Gulf.
Detailed virtopsy findings in Hong Kong
can be combined with surveys
of where these animals live
and how they use their habitat
to provide experts with a complete picture
on how to best protect them.
For humpback dolphins,
they live close to shore lines
throughout their range,
and these shorelines
are exactly where the majority
of our human impacts happen.
Understanding what human caused trauma,
such as entanglement or ship strike,
looks like in the body
of an Indo-Pacific humpback dolphin
can help responders recognize the trauma
in similar species,
such as a critically endangered
Atlantic humpback dolphin.
When we have a sick patient
in front of us,
time is of the essence.
It’s of the essence for us,
for wildlife species, for our ocean
and for the most important patient
that any of us will ever see:
our planet.
We must use these technologies
and innovations
to take ourselves outside
of the stretches of our imagination.
We must take these moonshots.
And yet equally as importantly,
we must transform the lessons
that arise from these complex procedures
into actions that are accessible for all.
So the next time that you see
an amazing image,
a captivating group of pixels,
remember that the healing impact
can extend far beyond a single patient.
Thank you.