00:01
So you can have
too little inflammation,
you can have
too much inflammation,
and these will be
important diseases.
00:08
So believe it or not,
there are patients
walking around out there
not too many,
but a few
that have defects in the synthesis
of their integrins.
00:16
So they don't bind
with firm adhesion
to the immunoglobulin
superfamily.
00:21
As a result,
they get recurrent infections.
00:24
They just don't get the cells
sticking to the endothelium,
so they can crawl across.
00:30
You can also have defects that lead
to diminished sialyl-Lewis X.
00:34
Remember,
sialyl-Lewis X
is going to be that
complex of sugars,
that binds to our selectins.
00:42
And if we don't make
the sialyl-Lewis X,
we don't get rolling.
00:46
Those patients also
get recurrent infections
because they don't have enough
acute inflammation.
00:53
You can also have defects
in phagolysosome formations.
00:56
So you've eaten a bug,
and you're getting ready
to bring in a lysosome
and have them fuse
to destroy that bug.
01:03
And yet, you have diseases
where you don't have that.
01:06
You don't have that fusion.
01:08
That's called
Chediak-Higashi syndrome.
01:10
Again, a rarity,
but it proves the point
about the biological importance
of each of these steps.
01:15
And these patients
get recurrent infections.
01:18
And then you can have
defects in microbicidal activity.
01:21
So there are patients who have
defects in the NADPH oxidase,
that's the one
that's going to be responsible
for getting protons
into that primary granule,
so that we can generate
the oxygen free radicals
and hydrogen peroxide.
01:35
And those patients
get recurrent infections.
01:39
Gee.
01:41
Cleverly, some bacteria have
learned how to make catalase.
01:44
They called it catalase is an enzyme
that degrades hydrogen peroxide.
01:49
If the bacteria
get into that primary granule,
and it make a lot of catalase,
we never make
the hypochlorous acid.
01:55
We don't make the bleach,
that's going to kill the bacteria.
01:58
And they do quite well.
01:59
So there are certain fairly
nasty bugs that make catalase,
and you will encounter those
in microbiology.
02:07
And there's too much inflammation.
02:09
So again, a lot of the
inflammatory mediators
are pretty much nonspecific.
02:15
They will kill bacteria,
pathogens, yes,
but they will also kill
normal tissue.
02:20
And you can have as you have here,
ongoing inflammation
that's just causing a lot of
tissue necrosis and damage.
02:29
When you have nothing
but pure neutrophils and bugs,
that's abscess.
02:34
And there is no tissue left behind.
It's just a collection of pus.
02:40
So that's exuberant,
acute inflammation.
02:42
You can have a loss of function
because of the appropriate
acute inflammatory response.
02:46
So in pneumonia,
we have bacteria in the lungs,
we recruit neutrophils,
we have increased
vascular permeability,
that's all part of
getting rid of the bug
and clearing the pneumonia.
02:57
But in the meantime,
all the airspace is filled up with
bacteria, and neutrophils, and water
from the
increased vascular permeability.
03:05
And so you may have
diminished function.
03:07
You may have hypoxia.
03:08
That's just part and parcel
of the normal response in the lung.
03:13
And then you can have
a systemic effects
of acute inflammation.
03:16
So, in sepsis,
the appropriate response to
elements of the bacterial cell wall
will sometimes give a very
profound cytokine activation.
03:27
When that happens,
those cytokines
that would normally
in a localized environment
just cause increased capillary,
post capillary venial permeability,
and will cause vasodilation.
03:41
Now, if you have those same
mediators in the entire body,
you have hypotension.
03:47
So in a localized environment,
doing exactly the right thing,
too much of the systemic mediators
being released
and you get no blood pressure,
hypotension.
03:57
Normally too,
in a localized environment,
we will want to make
the vessels procoagulant
because we're anticipating
there will be injury
and we want them to clot
appropriately.
04:07
And yet, if we do that now
systemically
because high levels of mediators,
we will get thrombosis everywhere,
not good.
04:16
So the combination of hypotension
and systemic thrombosis,
called disseminated
intravascular coagulation
is how septic shock
manifests itself.
04:29
So you can have
too little or too much.
04:32
Usually want to be
right in the middle.
04:36
With that we've covered
this huge range of territory
having to do with
acute inflammation.
04:41
The beginning of the process
that will allow us
to clear and digest dead stuff.
04:49
To get rid of the bacteria that
may have caused the dead stuff,
and then begin
the process of healing.