NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
10
29th January and 30th January.—Still very ill and depressed with puru-
lent discharge from the eyes.
Weight on 3oth January was 1,170 grammes.
31st January.—The animal is much better to-day and is eating well. After
this date it gradually improved : the weight increased rapidly, and the animal
ultimately recovered.
RABBIT 15.—Weight 1,610 grammes.
20th January 1902.—Received subcutaneously 4.8 milligrammes of venom,
i.e., 3 milligrammes per kilo.
21st January.—There is slight swelling at the site of inoculation : appears
slightly ill : there are, however, no marked symptoms.
22nd J anuary.—Weight 1,430 grammes. Is not eating much, but other-
wise appears to be in good health.
23rd January. —Weight 1,450 grammes. Depressed, but no marked
symptoms.
24th January. —Weight 1,390 grammes. Is very ill to-day : much emaci-
ated ; great muscular weakness.
25th January.—Weight 1,410 grammes. Has improved since yesterday.
26th January.—Is depressed and weak.
27th January.—Weight 1,140 grammes. Extreme emaciation and atrophy :
is very depressed : much muscular weakness, but no apparent paralysis.
28th January.—Found dead this morning.
Post-mortem examination revealed- no lesion of any of the internal organs.
As the above six experiments are typical examples of the chronic form of
intoxication with this venom, it is unnecessary to detail any more cases of this
class. It will be seen from the above data that this chronic condition of poison-
ing follows either an intravenous or a subcutaneous injection of the venom, if the
amount injected is not large enough to cause the acute form of intoxication.
Further, the symptoms of this chronic intoxication are well marked and distinctive.
Such a condition is never met with in experiments with cobra venom nor, in fact,
with the venom of any other species of snake with which I have worked.
These experiments, while confirming in the main points Wall's observations,
show that his description can be somewhat modified. Thus, he states that no
symptoms are observed during the first few days after the injection of the
poison. In my experience I have generally found that the animals are depressed
and refuse their food during this interval. Further, a careful weighment of the
animals shows that there is a progressive loss of weight even during this
early period, (vide monkey 6, and rabbits 9, 12, and 15). Again, Wall does
not mention the occurrence of paralysis in these chronic cases. He looks
upon the condition as being only one of great muscular weakness. I have not
been able to satisfy myself that there is no paralysis. There is, no doubt,
11
great muscular atrophy and, as a result, great weakness. In some of my cases,
however, I am inclined to think that paralysis accompanied this muscular
atrophy. Lastly, Wall has mentioned that no case under his observation
had recovered, if once these late symptoms had begun. I have observed
one such case which recovered, i.e., rabbit 12. This animal, as we have seen,
showed well marked symptoms, namely, loss of appetite and depression, great
loss of weight, muscular atrophy and a purulent discharge from the eyes. It
ultimately made a good recovery. This condition, even when well marked,
can be recovered from. In the great majority of cases, however, if the typical
symptoms have once appeared, a fatal result follows.
It is important and interesting to be able to put on record the histological
appearances which were found in the central nervous tissues of two of these
chronic cases, namely, monkeys 2 and 6. I am greatly indebted to Dr. Walter
K. Hunter of Glasgow for cutting, examining and describing the sections of
the tissues with which I provided him.
The following are Dr. Hunter's reports:—
MONKEY No. 2.—The tissues were fixed in perchloride of mercury, cut in
paraffin and stained according to Nissl's method by thionin and toluidin blue.
The parts examined were cortex, medulla and spinal cord. Sections were taken
from four levels of the medulla, from three levels of the cervical cord, from three
levels of the dorsal cord and from two levels of the lumbo-sacral enlargement.
In all of these there is evidence of the existence of diffuse chromatolysis
(primary degeneration), affecting a very considerable portion of the ganglion cells.
The change is most marked in the cortex, where one has difficulty in finding a
single normal cell. The vast majority of the cells have a rather deeply stained
plasma, and in this are scattered dust-like granules, the remnants of the Nissl
bodies. Many cells, too, show vacuolation of their plasma. This vacuolation
may probably be regarded as a fatty change. A few cells have their Nissl
bodies not yet entirely fragmented, but these are few in number, and it is doubt-
ful if one perfectly normal cell is to be found. In the medulla the changes are
not nearly so marked as in the cortex, but nevertheless throughout the whole of
the sections at the different levels in the medulla a very considerable proportion
of degenerated cells is to be seen. .These are most numerous in the VIIIth
nucleus, less so in the XIIth and less still in the Xth motor. In the XIIth
nucleus nearly all the cells show a certain breaking up of the Nissl granules,
but only in a small number of cells is there the typical dust-like fragmentation
affecting the whole cell as seen in the cells of the cortex.
The degenerative process is more marked in the cord than in the medulla,
though less so than in the cortex. It is about equally marked in the cervical,
dorsal and lumbo-sacral regions. In many of the sections through the cervical,
C 2
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and lumbo-sacral enlargements not more than 3 or 4 normal cells are to be seen.
Many cells have an almost clear plasma with a few dust-like granules scattered
throughout, but most of the cells have a darker plasma with more of these dust-
like granules. The degenerative process seems to affect the whole of the cell
uniformly, though in a few cells the fragmentation is more marked at the
periphery than round the nucleus. The nucleus in almost all the cells still
remains central.
Considering the appearances generally it may be said that the chromato-
lysis above described does not present the typical picture such as one sees it,
e.g., in a case of alcoholic neuritis. In the latter case the dust-like fragments
are better defined and more closely and orderly packed in the cell plasma. In
the case before us the fragmented granules are more scattered and, as has been
noted in the cortical cells, there is the vacuolation of the plasma. The
process here seems as if it were more acute than in alcoholic neuritis, more
as if the granules were being dissolved out, rather than definitely broken up.
MONKEY No. 6.—The parts of the nervous system examined were cortex,
pons, medulla and cord. Sections from these were stained by Nissl's method.
All the preparations showed at least some degeneration of cells, and in some
of the sections the degeneration was extremely well marked. Generally it was
more marked in the cells of the cord and cortex than in those of the nuclei
in the medulla and pons.
In the cervical cord not a single normal cell was to be found. Many cells
were simply outlines, without any granulation whatever (` ghost cells '). Some
cells stained more deeply and more diffusely than normal and the Nissl granules,
when present, were always fragmented. A good many cells were definitely
vacuolated. There seemed, too, a considerable diminution in the number of
the cells in each anterior horn. It was difficult to estimate this accurately, but
judging by comparison with monkey No. 2 the loss was undoubtedly almost
two-thirds of the normal number. In this cervical region some of the
sections included the posterior root ganglia. But the change in the cells of
these ganglia was much less marked than in the ganglion cells of the anterior
horns. Indeed, many of the posterior root ganglion cells seemed quite normal,
and few showed any marked degeneration. The contrast between the condition
of the anterior horn cells and the posterior root ganglion cells is a point to which
one would draw special attention. The appearances at the dorsal, lumbar and
sacral levels were much the same as were found in the cervical cord.
Of the ganglion cells in the medulla and pons a considerable proportion
showed well marked chromatolysis, but the changes were by no means so extreme
as those just described in the cord. This doubtless explains why movements
of the heart and respiration continued some time after paralysis of the other
muscles of the body.
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In the cortex the degenerative change was about as marked as in the
cord, there being many 'ghost cells ' and many more deeply stained cells, some
with fragmented granules and some with no granules at all. A considerable
proportion of the cells was vacuolated. It is difficult to give a reliable opinion
as to whether or not there was any considerable loss in the number of the cells
of the cortex.
The importance of these observations is at once evident. We have now
direct evidence of the action of the venom of Bungarus fasciatus on the nervous
system, an action which results in marked degenerative changes in the ganglion
cells of the cortex, cord, medulla and pons. These degenerative changes afford
also an explanation of the sympto ms which are observed in these chronic cases
of intoxication which I have described above. The depression, muscular
atrophy and paralysis are no doubt dependent on these pathological changes
which are so striking and well marked.
With these preliminary observations we have opened up a fruitful line of
research, the results of which should set at rest many disputed points as regards
the physiological actions of the venoms of the different species of poisonous
snakes. They should also, no doubt, throw some light on neuro-pathological
problems in general.
The action of the venom of Bungarus fasciatus on the blood
plasma in vivo and in vitro.
We have already seen (vide page 4) that, when a sufficiently large
quantity of the venom of Bungarus fasciatus is injected directly into the blood
stream of a rabbit, death takes place very rapidly, and that on post-mortem ex-
amination made immediately after death a more or less extensive intravascular
thrombosis is found. This clotting is confined to the pulmonary arteries and
right heart and does not appear to be present in the portal system of veins. The
quantity of poison which is necessary to produce this result is very much greater
than is the case with daboia venom. Further, the thrombosis is not nearly so
marked or so widespread as one finds with this latter venom. There can be
no doubt, however, that we are also dealing in this instance with the pheno-
menon of an increase of blood coagulability, brought about by the action of the
poison on the plasma, so great as to lead to an intravascular clotting in those
vessels in which it is more liable to occur, and that death in these cases is
due to thrombosis of the pulmonary arteries.
We have, now, to consider what is the condition of the blood coagulability in
those cases of intoxication, in which this temporary increase does not result in
a fatal thrombosis. When death takes place within a few hours after the
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injection of the poison, as we have seen occurs in the more rapidly fatal of the
acute class of nervous cases, the blood taken from the heart and from the inferior
vena cava is found to clot almost immediately after withdrawal, and the clots.
which form are firm and solid. This condition of blood coagulability was found
in four rabbits. The details of the experiments on these rabbits have already
been described, viz., rabbits 4, 5, 6 and 22. It is evident, then, that in this short
interval of time, viz., up to three or four hours, and with the quantities of venom
used, no appreciable diminution of the blood coagulability had developed,
When, however, death is delayed for a day or two after the injection of the
venom, there is evidence to show that an appreciable deficiency of blood coagu-
ability has developed. Thus, in the case of two rabbits, namely, Nos. 10 and 14,
the experiments on which have been recorded above, it was found that the blood
collected from the heart and from the inferior vena cava at the post-mortem
examinations made immediately after death clotted much more slowly than
normally, and that the clot which formed was loose and imperfect. These
animals died 48 and 26 hours, respectively, after the injection of the venom. In
addition to these observations the blood coagulation time has been estimated
at intervals in the case of five animals, namely, two rabbits and three monkeys,
which received an amount of venom that did not produce any acute nervous.
symptoms, and which later on developed nervous symptoms of the chronic type,
to which I have already drawn attention. The details of these observations are
given in the protocols, series No. II. A reference to this table will show that
in every instance a considerable deficiency in the blood coagulability was present.
This deficiency was observed on the first or second day after the injection of
the poison and persisted, as a rule, till the disease was ended by death or by
recovery.
In previous papers6 I have recorded similiar series of observations made
with both cobra and daboia venoms. In the case of the former poison I was
able to show that a slight diminution of blood coagulability takes place after the
subcutaneous injection of non-lethal doses, and that this diminution of blood
coagulability was more marked the nearer the quantity of venom injected ap-
proached to the minimum lethal dose. Further, in cases of cobra venom poisoning
one seldom sees any symptoms which might be due to this deficiency of blood
coagulability. Lastly, this poison causes no primary phase of increased coagu-
lability.
With daboia venom the lengthening of the blood coagulation time is much
more marked, amounting in some instances to a complete loss of coagulability, the
blood when drawn from the vessels remaining permanently liquid. Further, in
the case of intoxication with daboia venom I pointed out that symptoms, such as
widespread œdema and hæmorrhages, were observed, and that the marked defi-
15
ciency of blood coagulability might be an ætiological factor in the produc
-tion of these symptoms.
In the case before us now, i.e. , that of intoxication with the poison of
Bungarus fasciatus, the diminution of the blood coagulability is by no means ex--
cessive and cannot be said to be an important factor in the production of any
general symptoms observed. For, with the exception of an insignificant local
swelling at the site of injection no œdema is produced nor have any hæmorr--
hages been observed to occur. The symptoms referable to the action of the
poison on the nervous system are the predominant symptoms. The action of
this venom on the blood plasma in these chronic cases would appear to be of
very secondary importance.
We can now pass on to consider if the venom of Bungarus fasciatus has
any action on the coagulability of blood plasma in vitro. In one of the papers 7
above referred to I have put forward a method of testing in vitro the action of
snake venoms on whole blood and on plasma freed from red cells. This method
consists in adding different amounts of venom to blood, which has been kept
liquid by the addition of citrate of soda, and to citrate plasma which has been
completely freed from the red corpuscles by allowing them to sediment and
then syphoning off the clear supernatant fluid. Lime, in the form of a solu--
tion of chloride of calcium, is added in the quantity required. Working in this
way I showed that cobra venom completely prevents the clotting of citrate
plasma, which results normally from the addition of a small quantity of a soluble
salt of lime, and that daboia venom has a marked effect in increasing the coagu--
lability of citrate plasma. Even in small quantities, however, this latter
venom does not produce in vitro any diminution of blood coagulability, which
is such a prominent action in vivo.
This method was employed to study the action of the venom of Bungarus
fasciatus on citrate plasma in vitro (vide protocols, series Nos. III and IV).
In the first series of observations varying amounts of the venom were added
to 2 c.c. of citrate plasma, the plasma both of the donkey and of the horse being
employed. It was found that even 5 milligrammes of venom did not produce
after 24 hours a trace of clot in this amount of plasma. Now, I have already
shown that daboia venom in small quantities causes a firm clotting of citrate
horse plasma. It was found that any quantity of this poison between 3 and 5
milligrammes caused a firm clot in 2 c.c. of citrate horse plasma in less than
three hours; that with an amount between 0.4 and 1 milligramme clotting occur
-red but was delayed for about 20 hours; and that 0.2 milligramme caused only a
slight clot after 20 hours. The explanation of the failure in the experiments
with the venom of Bungarus fasciatus to cause clotting of citrate plasma in
vitro is probably to be found in the fact, that the venom was not added to the
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plasma in sufficient quantity. We have seen above that 8 to 10 milligrammes
per kilo. of this venom injected rapidly into the blood stream of a rabbit
are required to be certain of so increasing the blood coagulability as to lead
to a fatal intravascular thrombosis. Now, I have stated that a fatal intra-
vascular clotting can be brought about by 0. 1 milligramme per kilo. of daboia
venom, when injected intravenously into a rabbit, a quantity 80 to l00 times less.
than the amount of the venom of Bungarus fasciatus required to produce the
like effect. I have also mentioned that 0.4 milligramme of daboia venom causes
a firm clot to form after 20 hours in 2 c.c. of citrate plasma. Therefore, if there
is any analogy between the actions of these two venoms on the blood plasma, an
analogy which is almost certain in consideration of their actions on the blood
coagulability in vivo, we should expect that it would require between 30 and
40 milligrammes of the venom of Bungarus fasciatus to produce any clot in 2
c.c. of citrate plasma, provided always, as was the case in my experiments, that
the amount of citrate in the samples of plasma used was the same. It is to be
regretted that the quantity of venom at my disposal did not allow of such a large
amount as this being used. Therefore, until experiments are carried out with much
larger quantities of poison than I used, it is impossible to affirm that the action
of the venom of Bungarus fasciatus on the plasma is in any way different from
the action of daboia venom. It can, however, be said that daboia venom is in
this respect of much greater potency than the poison of Bungarus fasciatus.
We have seen above that in the more or less chronic cases of intoxica-
tion with the venom of Bungarus fasciatus there is a certain amount of defi-
ciency in the blood coagulability, but that there are few or no symptoms which
can be said to depend on this deficiency. A second series of experiments
was undertaken with the view of ascertaining if this poison had the power of
preventing the clotting of citrate plasma which results from the addition of a
soluble salt of lime. To each tube containing 2 c.c. of plasma varying amounts
of venom were added. From one to two hours afterwards there was added
to each tube a quantity of calcium chloride solution which clotted the control in
less than 15 minutes. A reference to the protocols (series No. IV) will show
that in every instance, both in the case of donkey plasma and in the case of
horse plasma, solid clotting took place after the addition of the lime solution.
In the paper to which I have referred above I showed that cobra venom
tested in the same manner, prevented the clotting of citrate plasma. The
action, therefore, of cobra venom on the blood plasma is evidently of a different
nature from that of the venom of Bungarus fasciatus. I showed, further, that
daboia venom, even in infinitesimal quantities, did not prevent this clotting.
From the consideration of all these experiments and observations it would
appear that the action of the venom of Bungarus fasciatus on the coagulability
1 7
of the blood plasma is analogous to that of daboia venom. The positive phase
of increased coagulability, which is seen in vivo when large quantities of this
venom are injected directly into the blood stream, is comparable to the similar
phenomenon brought about by small amounts of daboia venom. Again, both
these poisons produce in vivo a secondary negative phase of diminished coa-
gulability. This condition, however, is much better marked in cases of daboia
venom intoxication than in cases of poisoning with the venom of Bungarus
fasciatus, and is no doubt a factor in the ætiology of several of the symptoms
which are seen in cases of poisoning with the former venom. Further, when
tested in vitro with citrate plasma both these poisons failed to produce any
diminution in the normal coagulability of this plasma. The only discrepancy
in the analogy between these two venoms, as far as their action on the
coagulability of plasma is concerned, is the failure of the venom of Bungarus
fasciatus to produce clotting of citrate plasma. I have already explained the
reason of this failure in my experiments, namely, a deficiency in the amount
of venom added to each preparation. While, therefore, it is certain that the
actions of these two poisons on the blood plasma are similar, we have seen
that daboia venom is, as regards this particular action, of much greater
potency than the poison of Bungarus fasciatus, the action of which is mainly
on the nervous system. In this connection of analogous action of the venoms of
Daboia Russellii and Bungarus fasciatus it is interesting to remember that the
former snake is classified among the Viperidæ, and the latter among the Colubridæ.
The action of the venom of Bungarus fasciatus on the red blood
corpuscles in vivo and in vitro.
All experiments go to show that the venom of Bungarus fasciatus has
only a slight destructive action in vivo on the red blood corpuscles. In his
description of the physiological action of this poison Wall draws attention
to the fact that in a few fatal experimental cases he found an effusion of a
pale pinkish serum into the areolar tissue around the site of inoculation. In
no instance does he mention any symptoms or post-mortem appearances which
might be dependent on any great destruction of the red cells. The experience
I have had with this venom points to the same conclusion. I have never
seen any hæmoglobin-stained exudations, nor any red-stained discharge from
any ori fi ce. Furt her, at many p o s t - m o r t e m
e x a m i n a t i o n s , I h a v e c o l l e c t e d
blood from the heart and from the larger vessels, have allowed this blood to
clot and have noted that the serum which exuded from the clot was perfectly
clear and free from hæmoglobin. The venom of Bungarus fasciatus, therefore,
in vivo has only a slight if any destructive action on the red blood corpuscles.
Experiments were next undertaken to ascertain ìf this poison had any
D