PART I PATHOLOGICAL INVESTIGATION - (a) The disintegration of the neutrophil polymorphnuclear cells of the blood of a tuberculous individual is accelerated (when clotting is prevented.) in
vitro by the addition of tuberculin.
(b) This acceleration is not related to the degree
of skin hypersensitivity to tuberculin demonstrated
in the sale individual.
(c) The young polymorph is more susceptible to tuberculin than the more mature cell. This is a
tentative conclusion and the subject is worthy of
further investigation.
(d) The lymphocytes of a tuberculous individual
(within the conditions of this experiment) are much
less susceptible to damage by tuberculin.
(e) The action of tuberculin on the monocytes of a
tuberculous individual cannot be accurately determined because the number of these cells is too small.
(f) Tuberculin causes swelling and disappearance of
the granules, with-eventual disintegration of the
nucleus of the neutrophil polymorph from the sensitised body.
(g) Owing to the possibility of unavoidable error,
a method involving the differential counting of
leucocytes would not appear to be entirely suitable
for measuring accurately the cytotoxic effect of
tuberculin on the white blood corpuscles.
(h) A method suitable for measuring the cytotoxic
action of tuberculin on blood leucocytes in the
laboratory of the average hospital has not been
evolved.
(i) Heparin in the dilutions used is suitable for
an investigation of this nature involving the incubation of blood and the examination of the leucocytes.
(i) If the action of tuberculin on the neutrophil
polymorphs is taken as indicating, at least in some
part, the systemic response of the body, then the
local and systemic responses to tuberculin do not
necessarily correspond.
(k) Measurement of the action of tuberculin on
tissue cells would probably be a more reliable index
to tissue sensitivity than the response of the skin,
as it is independent of factors such as circulation
known to alter the response of the skin to excitor
substances.
(l) This finding may throw some light on the variable results obtained when an attempt has been made to
correlate changes in skin sensitivity with the clinical course of the disease in tuberculous patients.
Fluctuations in the skin reaction, which take place
in the course of the disease, may not necessarily be
accompanied by changes in systemic tissue sensitivity.
(m) The ease of performance, however, of the intracutaneous tuberculin test is of considerable importance in assessing its value as a measure of
tissue sensitivity.
PART II THERAPEUTIC INVESTIGATION - a) Para- aminosalicylic acid in the form of the
sodium para- aminosalicylate salt exerts a beneficial
effect in pulmonary tuberculosis.
b) This effect is-greatest in exudative lesions
and consists in the promotion of resolution of these
lesions.
c) The effect is not of a sufficient degree to
alter permanently the course of the disease in the
majority of advanced cases.
d) The greatest amount of benefit from P.A.S.
occurs in the first three months of treatment.
e) P.A.S. is instrumental in reducing the size
of certain cavities. The exact nature of the
change which takes place is not known.
f) P.A.S. produces an improvement in the general
condition of patients suffering from pulmonary tuberculosis.
g) A marked initial fall occurs in the blood
sedimentation rate following the administration of
P.A.S. in ,patients suffering from pulmonary tuberculosis.
h) No serious or irreversible toxic effects ensue
from the administration of the drug.
i) Within the limits of this uncontrolled study,
the effect of P.A.S. is not strikingly related to
the length of course, or level of blood concentration
obtained.
j) Para- aminosalicylic acid is not a therapeutic
agent of the first importance in the treatment of
pulmonary tuberculosis, and its value in the future
may lie in combination with streptomycin.
