Dear listeners! Warning: this course contains shocking materials and is not recommended for viewing to persons with weak psyche, minors and pregnant women. The course describes subject and methods of Pathophysiology, its place within system of biomedical sciences and history. It includes General Nosology (concept of health and disease, general etiology and pathogenesis, pathological processes and states, role of causal factors, conditions, reactivity and somatotype in pathology). It gives systematic of locally and centrally driven typical pathological processes: arterial, venous and combined hyperemiae, stasis, inflammation, immunopathological processes (including allergy and autoimmune disorders) acute phase response, fever, stress, shock, etc. Course deals with functional, metabolic and informational aspects of typical pathologic processes, like disorders of signaling, reception, post – receptor translation, programming and program archiving, conflicts of programs in living systems. It contains the consequent analysis of the injury and defensive responses as regards separate cells, organs and tissues and the whole organism. The lectures based on author’s original three-volumed textbook and workshop in Pathophysiology republished in Russia many times.
2_3 "General Aetiology & General Pathogenesis"
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From the course by Saint Petersburg State University
General Pathophysiology
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From the lesson
General Nosology. Health and Disease
Meet the Instructors
Churilov Leonid PavlovichAssociate Professor, Full Member of International Academy of Sciences (Health and Ecology)
Department of Pathology, Faculty of Medicine
The next section of our talk about general aetiology and general pathogenesis.
Aetiology is a section of General Nosology which deals with the causes,
causative factors, and conditions of diseases,
their primary interaction with organism.
Aetiology reveals and theoretically describes
set of risk factors and anti-risk factors for every particular disease.
The list of risk factors can be very long.
For example, for the disease named atherosclerosis,
there are 232 large and small officially recognized risk factors.
Every risk factor increases the probability of disease,
or it increases the severity of disease if the disease already exists.
Anti-risk factor, vice-versa, facilitate the prevention of
disease or decreases its severity.
The next thing about aetiology is that aetiology is
very necessary for many practical branches of healthcare.
For example, for epidemiology,
aetiological knowledge is necessary for purposeful rational prevention of disease.
Aetiology also contributes into therapy, into surgery,
because both need aetiotropic treatment,
and they need to also to know aetiology of
diseases for aetiological classification of diseases.
But in some cases,
if the process is autochthonic,
like in my previous example,
aetiotropic treatment is not possible because mosquito has already flew away.
How can you treat the aetiological factor if it no longer exists, but process continues?
How can you apply aetiotropic treatment if the aetiologic factor no longer in action?
For cases like that,
we need pathogenetic treatment,
and that is next section of our talk.
Look at this example: LEPRA.
LEPRA is severe infectious disease.
You can see a symptom of the disease, so-called lion's face.
You can put diagnosis,
but you do not know the mechanism.
You do not know the aetiology.
You do not know the pathogenesis.
Then, pathologists come and start to explore.
And we have already mentioned in my previous lecture, discovered that globes,
this are skin macrophages,
and you can see inside of them, acidophilic bacteria.
And that person with microscope, Armauer Hansen,
determined which bacteria is responsible for LEPRA.
He discovered myco bacteria of LEPRA.
And as soon as he discovered aetiological factor,
aetiotropic treatment became possible.
And you can see here the
Drugs for example dapsone,
invented by pharmacists especially to heat that mycobacteria leprae.
So if you do not know the aetiology you cannot apply etiotropic treatment.
Now a few words about general pathogenesis.
General pathogenesis is a section of General Nosology and it answers
the question how, how disease develops.
Aetiology answer the question why,
why disease started, but disease has also duration, cause, outcome,
individual specifics, and all of them belongs to the domain of pathogenesis.
Pathogenesis is a doctrine of the mechanisms of disease development,
cause, individual variance, and outcomes.
It answers how it develops.
Infact, pathogenesis is a cybernetics of disease,
cybernetics of it's self-motion, self-movement.
It is system of causative links and relations.
And one may separate within pathogenesis, within pathogenetic mechanisms,
two tendencies, the tendency of healing or sanogenesis,
and the tendency of aggravation or autopathokinesis.
As a result,
pathogenesis is not just a straight way to health or straight way to coffin.
Pathogenesis is very, very complicated
network of the links between reasons and consequences.
And pathogenesis combines tendency of sanogenesis
and tendency of self injury or autopathokinesis.
Pathogenesis is very important for practical medicine.
It gives to health care information necessary for disease classification,
pathogenetic classification, inflammatiory disease,
marrow plastic disease, the difference is in pathogenesis not in aetiology.
Also pathogenesis gives the information necessary for correct diagnosis.
How to combine all data of clinical examination or
of patients interview of laboratory studies.
To combine it, you need to construct this network of
links between various data you obtained as medical doctors,
so you construct the model of pathogenesis for correct diagnosis.
Pathogenesis also establishes in practical medicine,
correct forecast and correct pathogenetic treatment.
Look at this picture, you can see here two triangles.
One of them is bottom up.
These are two tendencies of pathogenesis,
sanogenic tendency and pathogenic tendency.
Pathogenic is from health through the premorbid state to disease,
and sanogenic is vice versa,
from disease to health.
It is like two trains moving opposite direction on different rails,
but situation in a real disease is much more complicated.
It is not like two parallel lines of rails,
one separate from another.
These trains, train of sanogenesis and train of autopathokinesis, they may
stand on the same rails and they may crush each other.
Now let us talk a little bit about acute diseases and chronic diseases.
What is the principal difference? Is it time?
Are all acute diseases short?
No, not all acute diseases are of short duration.
For example, acute renal failure.
Between the initial catastrophic event and
the moment when patient survived and completely restores all renal functions,
between the beginning and recuperation,
there are 12 months,
and it is acute renal failure.
It is acute in first day,
it is acute after first week, it is acute after first month,
and even in the last stage before complete recuperation after several months,
it is still acute.
It will never be chronic.
So not all acute processes and acute diseases with time,
are transfigurated into chronic ones.
For example, acute renal failure is never transformed into chronic.
Chronic renal failure also exist but that is train on another rails.
Chronic renal failure or correlate of progressive nephrosclerosis,
it starts as primary chronic process.
It is chronic from the first day of its existence.
Atherosclerosis is chronic process and it never was acute,
it started as chronic.
Acute maxillary sinusitis with time,
may transfigurate into chronic maxillary sinusitis.
But acute leukemia, never is transfigurated into chronic one.
These are different diseases.
Chronic leukemia is primary chronic,
acute leukemia is acute until the last day.
Even after several months,
it is still acute.
Why? Because acute leukemia and chronic leukemia has different clonal basis.
Acute leukemia is because
malignant leukemic clone of cell does not differentiate at all.
Chronic leukemia is another thing.
Malignant clone is differentiating,
even it can accomplish rather advanced degree of majoring but still malignant.
So, not everything which is acute is short.
Some acute processes are very long and still acute.
Not all chronic processes in medicine start with acute phase,
some of them start as primary chronic.
There are acute diseases which never get chronic,
for example chronic shock.
It is not possible to have chronic shock.
Shock is acute from the very beginning until the very end.
So what is the main difference between acute and chronic?
It is not time,
it is not duration, but what is it?
It is autochthonicity, autochthony.
The main difference between acute and chronic process is a degree of autochthony.
Acute processes in medicine are highly autochthonic.
They are independent from the continuation of the action of the causative agent.
But chronic processes, they require constant pushing action of causative agent.
In acute process, causative aetiologic agent is just a trigger.
In the chronic process,
it is constantly pushing force. Look at this picture.
If you will push kidney,
it will go down the slope automatically without
any additional force from the top of hill down hill.
And in the right side of picture,
to mount kidney on the top,
you need constant pushing force.
So for chronic process,
you need constant pushing force.
For example, for chronic renal failure,
you need constant pushing process like sugar diabetes for example, or autoimmunity.
But for acute renal failure,
you need just catastrophic event with short action of the aetiologic agent.
And after car accident,
after a traumatic shock,
which lasts several minutes or several hours,
kidney is not healthy for 12 month.
That is the difference between acute and chronic.
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