close

Вход

Забыли?

вход по аккаунту

?

The use of colloidal mercuric sulphide in morphological studies.

код для вставкиСкачать
T H E USE O F COLLOIDAL MERCURIC SULPHIDE I N
MORPHOLOGICAL STUDIES
TRUMAN SQ!UIRE POTTERi
Laboratory of Preventive Medicine, The University of Chicago
The introduction of finely divided particulate matter into
the living organism with a determination of its differential
localization is a method long used in biological studies. The
types of material so employed have been various, ranging
from solid carbon particles to the highly dispersed colloidal
trypan blue.
The method, as often used! with the higher animals, however, is seriously limited by the fact that most types of
suspended particles when introduced directly into the blood
stream tend to aggregate in embolic masses. Such masses
not only cause anomalies in distribution, but so far threaten
the life of the animal as to restrict seriously the amount of
material which may be injected and also the time allowed for
its distribution.
I n the course of studies of the blood capillaries of the liver,
in relation to tuberculous lesions, I have made extensive use
of the intravenous injection of various types of particulate
matter into living birds and mammals. With most of the
substances used I have encountered the limitations referred
to above, but in colloidal mercuric sulphide have found a
reagent so free from these liirnitations that I wish to emphasize its superiority as a pigment for in-vivo injection.
The colloidal mercuric-sulphide suspensions which I used
were specially prepared by Hermann Hille,2 Chicago, and
Seymour Coman Fellow i n Preventive Medicine.
A. M. A., vol. 92, p. 1349, April 20,
1929.
* Council on Pharm. and Chem.: Journal
197
198
TRUMAN SQUIRE POTTER
did not contain the alcohol or tricresol sometimes added as
preservatives. They were free from any trace of hydrogen
sulphide. The dispersion of the mercuric sulphide in these
preparations is such that the particles cannot be resolved by
the highest powers of the microscope ; they are demonstrable
by the ultramicroscope. The color of the suspension is jet
black, and the stability is very great. When the suspension
is evaporated to dryness, there results a black lustrous
enamel, which redisperses in added water.
The concentration of mercuric sulphide in the suspensions
used was varied from 1 to 8 per cent. The total amount of
the sulphide which may be given as a single injection is very
great. Pigeons receiving even such massive injections that
their blood contains 2 per cent mercuric sulphide survive
for a sufficient period to afford a general distribution of the
pigment and its differential localization. Corresponding
amounts may be used in rabbits, guinea-pigs, and monkeys.
Such large doses, of course, are indicated chiefly where it
is desired to obtain the maximal in-vivo injection of the
vascular bed. For general experimentation much smaller
doses are employed. Thus 1 cc. of a 1 per cent suspension
injected into a 300-gram pigeon suffices to demonstrate the
localization of the pigment in fixed-tissue phagocytes.
The mercuric sulphide, as one of the most generally insoluble salts known, is not extracted in the technique of tissue
fixation and staining. Even in special methods the use of
formalin, potassium dichromate, alcohol, toluol, sodium thiosulphate, and even 25 per cent C.P. sulphuric acid does not
filch the pigment. One precaution, however, must be observed-the avoidance of iodine. The briefest treatment of
sections with Lugol’s solution, for instance, will result in
the complete removal of the pigment. This fact in itself,
however, may be employed to great advantage in control
sections where it is desired to examine cellular structures
otherwise obscured by the mercuric sulphide.
As previously stated, the dispersion of the colloid is of a
very high order in the preparations furnished by Hille. When,
USE O F COLLOIDAL M E R C U R I C S U L P H I D E
199
for special reasons, it is desired to inject the mercuric
sulphide in a less dispersed form, it may be aggregated by
subjecting the suspension to evaporation by moderate heat.
The primary purpose of this paper is to call attention to
colloidal mercuric sulphide as a favorable pigment for in-vivo
injection, and the particular morphological findings which
have.been obtained by its use will be the subject of a subsequent publication. It may be stated at this time, however,
that the earliest removal of the pigment from the blood
stream is accomplished by those fixed-tissue phagocytes
which Kyes3 designated hemophages ; that in pigeons the
endothelium of the venous siinusoids of the liver, as impregnated by the sulphide, forms a complete vascular wall; and
that in the histogenesis of tubercles in the liver of pigeons,
occlusion of the venous capillaries by enlargement and fusion
of the hemophages is an early and determining factor both
in giant-cell and tubercle formation.*
Ryes: Internat. Monat. Anat. u. P'hysiol., 1914, Bd. 31, S. 543.
'Rogers: Amer. Rev. Tuberculosis, 1928, vol. 17, p. 192 (footnote, p. 200).
a
Документ
Категория
Без категории
Просмотров
0
Размер файла
145 Кб
Теги
colloidal, sulphide, morphological, use, studies, mercuric
1/--страниц
Пожаловаться на содержимое документа