00:00
Don’t let them do that to you.
00:01
Okay, so let’s take a look at our G6PD
and a couple of things
that are important for us.
00:06
So here,
I want you to move to the left and I
want you to identify glucose here.
00:11
And then this is the glycolytic pathway.
00:14
We’re going to branch off
the glycolytic pathway
and there’s my rate-limiting enzyme, G6PD,
glucose-6-phosphate dehydrogenase.
00:22
What are you going to form?
Look, you took NADP and you formed NADPH.
00:28
Where do you actually
require that NADPH for?
You’re going to take oxidized
glutathione and you will reduce it.
00:35
Remember in biochemistry, if you reduce
something, what does that mean to you?
Oh, yeah, you create the active form.
00:41
So here’s my GSH,
that is the reduced
form of glutathione.
00:45
Ladies and gentlemen,
that is what protects us.
00:49
That is what protects the RBC.
00:52
Against whom?
Free radicals.
00:55
What does a free radical mean to you?
Oxygen and company.
00:59
So for example, do you
remember superoxides?
Do you remember hydrogen peroxide?
Which one are we seeing here?
That’s hydrogen peroxide.
01:09
That’s a free radical.
01:10
But where did it come from?
Take a look at that box.
01:13
Infections most commonly.
01:16
Doesn’t that then produce free radicals?
Of course, drugs such as –
Remember antimalarials.
01:22
I told you if you’re about
to go to a tropical country
and you’re taking antimalarials
for months and months and months.
01:29
You’re introducing free radicals.
01:31
What was the name of that bean in the
Mediterranean that they consume in their diet?
The fava bean.
01:36
So all of these would then be
introducing a free radical,
that GSH, which is the glutathione.
01:43
We’ll take the free radical, hydrogen
peroxide and make it into water,
which is completely benign and
it’s a neutralizer, isn’t it?
So imagine, please, that your
patient doesn’t have G6PD.
01:59
You're not going
to produce NADPH.
02:01
You don’t activate glutathione.
02:02
Uh-oh, free radical damage.
02:05
What is it going to cause damage to?
That hemoglobin.
02:08
What do you call that hemoglobin now?
Heinz body.
02:12
Who are you going to attract?
Phagocytic cell.
02:15
What do you produce?
Bite cells.
02:17
What was that other
thing that I told you?
Not only do we have hemolytic anemia, but
you also have susceptibility to infection.
02:24
What kind of organisms?
Catalase-positive.
02:29
Everything that we just talked
about here is what you’re seeing.
02:31
It’s all lined up, X-linked recessive.
02:35
And then the last little part that I wish
to add is the part on the top, very right,
and you find that if you
don’t have G6PD deficiency,
you end up forming
your Heinz bodies.
02:45
In terms of its hemolysis,
it could either intravascular or it
could be extravascular, is that clear?
Take a look at that arrow, where it
says G6PD deficiency, that’s important.
02:55
Intra or extravascular,
both instances occur.
03:03
What we’re looking at here in
this picture is your Heinz body.
03:08
How does this occur?
Free radical exposure,
fava beans,
infections,
drugs.
03:14
What are you going to find next?
You’re going to find bite cells.