THE STOMACH
Laboratory methods may be applied to the diagnosis of stomach
disorders in: I. Examination of the gastric contents removed with the
stomach-tube. II. Certain other examinations which give information as
to the condition of the stomach.
I. EXAMINATION OF THE GASTRIC CONTENTS
Stomach digestion consists mainly in the action of pepsin upon
proteids in the presence of hydrochloric acid and in the curdling of
milk by rennin.
Pepsin and rennin are secreted by the gastric glands as
zymogens--pepsinogen and renninogen, respectively--which are converted
into pepsin and rennin by hydrochloric acid. Hydrochloric acid is
secreted by certain cells of the fundus glands. It at once combines
loosely with the proteids of the food, forming acid-albumin, the first
step in proteid digestion. Hydrochloric acid, which is thus loosely
combined with proteids, is called "combined" hydrochloric acid. The
acid which is secreted after the proteids present have all been
converted into acid-albumin remains as "free" hydrochloric acid, and,
together with pepsin, continues the process of digestion.
At the height of digestion the stomach-contents consist essentially
of: (1) Water; (2) free hydrochloric acid; (3) combined hydrochloric
acid; (4) pepsin; (5) rennin; {214} (6) mineral salts, chiefly acid
phosphates, of no clinical importance; (7) particles of undigested and
partly digested food; (8) various products of digestion in solution.
In pathologic conditions there may be present, in addition, various
microscopic structures and certain organic acids, of which lactic acid
is most important.
* * * * *
A routine examination is conveniently carried out in the following
order:
(1) Give the patient a test-meal upon an empty stomach, washing the
stomach previously if necessary.
(2) At the height of digestion, usually in one hour, remove the
contents of the stomach with a stomach-tube.
(3) Measure and examine macroscopically.
(4) Filter. A suction filter is desirable, and may be necessary when
much mucus is present.
(5) During filtration, examine microscopically and make qualitative
tests for--(_a_) free acids; (_b_) free hydrochloric acid; (_c_)
lactic acid.
(6) When sufficient filtrate is obtained, make quantitative
estimations of--(_a_) total acidity; (_b_) free hydrochloric acid;
(_c_) combined hydrochloric acid (if necessary).
(7) Make whatever additional tests seem desirable, as for blood,
pepsin, or rennin.
A. OBTAINING THE CONTENTS
Gastric juice is secreted continuously, but quantities sufficiently
large for examination are not usually obtainable from the fasting
stomach. In clinical work, therefore, it is desirable to stimulate
secretion with food--which is the natural and most efficient
stimulus--before attempting to collect the gastric fluid. Different
foods stimulate secretion to different degrees; hence for the sake of
uniform results certain standard "test-meals" have been {215} adopted.
Those mentioned here give practically the same results.
1. Test-meals.--It is customary to give the test-meal in the morning,
since the stomach is most apt to be empty at that time. If it be
suspected that the stomach will not be empty, it should be washed out
with water the evening before.
(1) Ewald's test-breakfast consists of a roll (or two slices of bread)
without butter and two small cups (300 to 400 c.c.) of water or weak
tea without cream or sugar. It should be well masticated. The contents
of the stomach are to be removed one hour afterward. This test-meal is
used for most routine examinations. Its disadvantage is that it
introduces, with the bread, a variable amount of lactic acid and
numerous yeast-cells. This source of error may be eliminated by
substituting a shredded whole-wheat biscuit for the roll.
(2) Boas' test-breakfast consists of a tablespoonful of rolled oats in
a quart of water, boiled to one pint, with a pinch of salt added. It
should be withdrawn in forty-five minutes to one hour. This meal does
not contain lactic acid, and is usually given when detection of lactic
acid is important, as in suspected gastric cancer. The stomach should
always be washed with water the evening previous.
2. Withdrawal of the Contents.--The Boas stomach-tube, with bulb, is
probably the most satisfactory form. It should be of rather large
caliber, and have an opening in the tip and one or two in the side
near the tip. When not in use, it should be kept in a vessel of borax
solution, and should be well washed in hot water both before and after
using.
It is important confidently to assure the patient that introduction of
the tube cannot possibly harm him; and {216} that, if he can control
the spasm of his throat, he will experience very little choking
sensation. When patients are very nervous, it is well to spray the
throat with cocain solution.
The tube should be dipped in warm water just before using: the use of
glycerin or other lubricant is undesirable. With the patient seated
upon a chair, his clothing protected by towels or a large apron, and
his head tilted forward, the tip of the tube, held as one would a pen,
is introduced far back into the pharynx. He is then urged to swallow,
and the tube is pushed boldly into the esophagus until the ring upon
it reaches the incisor teeth, thus indicating that the tip is in the
stomach. If, now, the patient cough or strain as if at stool, the
contents of the stomach will usually be forced out through the tube.
Should it fail, the fluid can generally be pumped out by alternate
compression of the tube and the bulb. If unsuccessful at first, the
attempts should be repeated with the tube pushed a little further in,
or withdrawn a few inches, since the distance to the stomach is not
the same in all cases. The tube may become clogged with pieces of
food, in which case it must be withdrawn, cleaned, and reintroduced.
If, after all efforts, no fluid is obtained, another test-meal should
be given and withdrawn in forty-five minutes.
As the tube is removed, it should be pinched between the fingers so as
to save any fluid that may be in it.
The stomach-tube must be used with great care, or not at all, in cases
of gastric ulcer, aneurysm, uncompensated heart disease, and marked
arteriosclerosis. Except in gastric ulcer, the danger lies in the
retching produced, and the tube can safely be used if the patient
takes it easily.
{217} B. PHYSICAL EXAMINATION
Under normal conditions, 30 to 50 c.c. of fluid can be obtained one
hour after administering Ewald's breakfast. More than 60 c.c. points
to motor insufficiency; less than 20 c.c., to too rapid emptying of
the stomach, or else to incomplete removal. Upon standing, it
separates into two layers, the lower consisting of particles of food,
the upper of an almost clear, faintly yellow fluid. The extent to
which digestion has taken place can be roughly judged from the
appearance of the food-particles.
The _reaction_ is frankly acid in health and in nearly all pathologic
conditions. It may be neutral or slightly alkaline in some cases of
gastric cancer and marked chronic gastritis, or when contaminated by a
considerable amount of saliva.
A small amount of _mucus_ is present normally. Large amounts, when the
gastric contents are obtained with the tube and not vomited, point to
chronic gastritis. Mucus is recognized from its characteristic slimy
appearance when the fluid is poured from one vessel into another.
A trace of _bile_ may be present as a result of excessive straining
while the tube is in the stomach. Larger amounts are very rarely
found, and generally point to obstruction in the duodenum. Bile
produces a yellowish or greenish discoloration of the fluid.
_Blood_ is often recognized by simple inspection, but more frequently
requires a chemic test. It is bright red when very fresh, and dark,
resembling coffee-grounds, when older.
_Particles of food_ eaten hours, or even days, previously, may be
found, and indicate deficient motor power.
{218} Search should always be made for _bits of tissue_ from the
gastric mucous membrane or newgrowths. These, when examined by a
pathologist, will sometimes render the diagnosis clear.
C. CHEMIC EXAMINATION
A routine chemic examination of the gastric contents involves
qualitative tests for free acids, free hydrochloric acid, and organic
acids, and quantitative estimations of total acidity, free
hydrochloric acid, and sometimes combined hydrochloric acid. Other
tests are applied when indicated.
1. Qualitative Tests.--(1) Free Acids.--The presence or absence of
free acids, without reference to the kind, is easily determined by
means of Congo-red.
* * * * *
Congo-red Test.--Take a few drops of a strong alcoholic solution of
Congo-red in a test-tube, dilute with water to a strong red color, and
add a few cubic centimeters of filtered gastric juice. The appearance
of a _blue color_ shows the presence of some free acid (Plate IX, B,
B'). Since the test is more sensitive to mineral than to organic
acids, a marked reaction points to the presence of free hydrochloric
acid.
Thick filter-paper soaked in Congo-red solution, dried, and cut into
strips may be used, but the test is much less delicate when thus
applied.
* * * * *
(2) Free Hydrochloric Acid.--In addition to its digestive function,
free hydrochloric acid is an efficient antiseptic. It prevents or
retards fermentation and lactic-acid formation, and is an important
means of protection against the entrance of pathogenic organisms into
the body. It is never absent in health.
* * * * *
{219} Amidobenzol Test.--To a little of the filtered gastric juice in
a test-tube, or to several drops in a porcelain dish, add a drop of
0.5 per cent. alcoholic solution of dimethylamido-azobenzol. In the
presence of free hydrochloric acid there will at once appear a
_cherry-red color_, varying in intensity with the amount of acid
(Plate X, C). This test is very delicate; but, unfortunately, organic
acids, when present in large amounts (above 0.5 per cent.), give a
similar reaction.
Boas' Test.--This test is less delicate than the preceding, but is
more reliable, since it reacts only to free hydrochloric acid.
In a porcelain dish mix a few drops of the gastric juice and the
reagent, and slowly evaporate to dryness over a flame, _taking care
not to scorch_. The appearance of a _rose-red color_, which fades upon
cooling, shows the presence of free hydrochloric acid (Plate IX, 1).
_Boas' reagent_ consists of 5 gm. resublimed resorcinol, and 3 gm.
cane-sugar, in 100 c.c. alcohol. The solution keeps well, which, from
the practitioner's view-point, makes it preferable to Günzburg's
phloroglucin-vanillin reagent (phloroglucin, 2 gm.; vanillin, 1 gm.;
absolute alcohol, 30 c.c.). The latter is just as delicate, is applied
in the same way, and gives a sharper reaction (Plate IX, 2), but is
unstable.
* * * * *
(3) Organic Acids.--Lactic acid is the most common, and is taken as
the type of the organic acids which appear in the stomach-contents. It
is a product of bacterial activity. Acetic and butyric acids are
sometimes present. Their formation is closely connected with that of
lactic acid, and they are rarely tested for. When abundant, they may
be recognized by their odor upon heating.
Lactic acid is never present at the height of digestion in health.
Although usually present early in digestion, it disappears when free
hydrochloric acid begins to appear. {220} Small amounts may be
introduced with the food. Pathologically, small amounts may be present
whenever there is stagnation of the gastric contents with deficient
hydrochloric acid, as in many cases of dilatation of the stomach and
chronic gastritis. The presence of notable amounts of lactic acid is
significant of gastric cancer, and is probably the most valuable
single symptom of the disease. In the great majority of cases
detection of more than 0.1 per cent. (see Strauss' test) warrants a
diagnosis of malignancy.
As already stated, the Ewald test-breakfast introduces a small amount
of lactic acid, but rarely enough to respond to the tests given here.
In every case, however, in which its detection is important, Boas'
test-breakfast should be given, the stomach having been thoroughly
washed the evening before.
* * * * *
Uffelmann's Test for Lactic Acid.--Thoroughly shake up 5 c.c. of
filtered stomach fluid with 50 c.c. of ether for at least ten minutes.
Collect the ether and evaporate over a water-bath. Dissolve the
residue in 5 c.c. water and test with Uffelmann's reagent as follows:
In a test-tube mix three drops concentrated solution of phenol and
three drops saturated aqueous solution of ferric chlorid. Add water
until the mixture assumes an amethyst-blue color. To this add the
solution to be tested. The appearance of a _canary-yellow color_
indicates the presence of lactic acid (Plate IX, A, A').
Uffelmann's test may be applied directly to the stomach-contents
without extracting with ether, but is then neither sensitive nor
reliable.
[Illustration: PLATE IX.
A, Uffelmann's reagent; A', A after the addition of gastric fluid
containing lactic acid; B, water to which three drops of Congo-red
solution have been added; B', change induced in B when gastric fluid
containing free hydrochloric acid is added (Boston).
1, Resorcin-test for free hydrochloric acid; 2, Günzburg's test for
hydrochloric acid (Boston).]
Strauss' Test for Lactic Acid.--This is the best test for clinical
work, since it gives a rough idea of the quantity present. Strauss'
instrument (Fig. 87) is essentially a separating funnel with a mark at
5 c.c. and one at 25 c.c. Fill to the 5 c.c. mark {221} with filtered
stomach fluid, and to the 25 c.c. mark with ether. Shake thoroughly
for ten or fifteen minutes, let stand until the ether separates, and
then, by opening the stop-cock, allow the liquid to run out to the
5 c.c. mark. Fill to the 25 c.c. mark with water, and add two drops of
tincture of ferric chlorid diluted 1:10. Shake gently. If 0.1 per
cent. or more lactic acid be present, the water will assume a strong
yellowish-green color. A pale green will appear with 0.05 per cent.
[Illustration: FIG. 87.--Separatory funnel for Strauss' lactic acid
test (Sahli).]
* * * * *
(4) Pepsin and Pepsinogen.--Pepsinogen itself has no digestive power.
It is secreted by the gastric glands, and is transformed into pepsin
by the action of a free acid. Although pepsin digests proteids best in
the presence of free hydrochloric acid, it has a slight digestive
activity in the presence of organic or combined hydrochloric acids.
The amount is not influenced by neuroses or circulatory disturbances.
Absence or marked diminution, therefore, indicates organic disease of
the stomach. It is an important point in diagnosis between functional
and organic conditions. Pepsin is rarely or never absent in the
presence of free hydrochloric acid.
* * * * *
Test for Pepsin and Pepsinogen.--With a cork-borer cut small cylinders
from the coagulated white of an egg, and cut these into discs of
uniform size. The egg should be cooked very slowly, preferably over a
water-bath, so that the white may be readily digestible. The discs may
be preserved in glycerin, but must be washed in water before using.
{222} Place a disc in each of three test-tubes.
Into tube No. 1 put 10 c.c. distilled water, 5 grains pepsin, U.S.P.,
and 3 drops of the official dilute hydrochloric add.
Into tube No. 2 put 10 c.c. filtered gastric juice.
Into tube No. 3 put 10 c.c. filtered gastric juice and 3 drops dilute
hydrochloric acid.
Place the tubes in an incubator or warm water for three hours or
longer. At intervals, observe the extent to which the egg-albumen has
been digested. This is recognized by the depth to which the disc has
become translucent.
Tube No. 1 is used for comparison, and should show the effect of
normal gastric juice.
Digestion of the egg in tube No. 2 indicates the presence of both
pepsin and free hydrochloric acid.
When digestion fails in tube No. 2 and occurs in No. 3, pepsinogen is
present, having been transformed into pepsin by the hydrochloric acid
added. Should digestion fail in this tube, both pepsin and pepsinogen
are absent.
* * * * *
(5) Rennin and Renninogen.--Rennin is the milk-curdling ferment of the
gastric juice. It is derived from renninogen through the action of
hydrochloric acid. Lime salts also possess the power of transforming
renninogen into the active ferment.
Deficiency of rennin has the same significance as deficiency of
pepsin, and is more easily recognized. Since the two enzyms are almost
invariably present or absent together, the test for rennin serves also
as a test for pepsin.
* * * * *
Test for Rennin.--Neutralize 5 c.c. filtered gastric juice with very
dilute sodium hydroxid solution; add 5 c.c. fresh milk, and place in
an incubator or in a vessel of water at about 104° F. Coagulation of
the milk in ten to fifteen minutes shows a normal amount of rennin.
Delayed coagulation denotes a less amount.
{223} Test for Renninogen.--To 5 c.c. neutralized gastric juice add
2 c.c. of 1 per cent. calcium chlorid solution and 5 c.c. fresh milk,
and place in an incubator. If coagulation occurs, renninogen is
present.
* * * * *
(6) Blood.--Blood is present in the vomitus in a great variety of
conditions. When found in the fluid removed after a test-meal, it
commonly points toward ulcer or carcinoma. Blood can be detected in
nearly one-half of the cases of gastric cancer. The presence of
swallowed blood must be excluded.
* * * * *
Test for Blood in Stomach-contents.--To 10 c.c. of the fluid add a few
cubic centimeters of glacial acetic acid and shake the mixture
thoroughly with an equal volume of ether. Separate the ether and apply
to it the guaiac test (p. 89); or evaporate and apply the hemin test
(p. 202) to the residue. When brown particles are present in the
fluid, the hemin test should be applied directly to them.
* * * * *
2. Quantitative Tests.--(1) Total Acidity.--The acid-reacting
substances which contribute to the total acidity are free hydrochloric
acid, combined hydrochloric acid, acid salts, mostly phosphates, and,
in some pathologic conditions, the organic acids. The total acidity is
normally about 50 to 75 _degrees_ (see method below), or, when
estimated as hydrochloric acid, about 0.2 to 0.3 _per cent._
* * * * *
Töpfer's Method for Total Acidity.--In an evaporating dish or small
beaker (an "after-dinner" coffee-cup is a very convenient substitute)
take 10 c.c. filtered stomach-contents and add three or four drops of
the indicator, a 1 per cent. alcoholic solution of phenolphthalein.
When the quantity of stomach fluid is small, 5 c.c. may be used, but
results are less accurate than with a larger amount. Add decinormal
solution {224} of sodium hydroxid drop by drop from a buret, until the
fluid assumes a rose-red color which does not become deeper upon
addition of another drop (Plate X, A, A'). When this point is reached,
all the acid has been neutralized. The end reaction will be sharper if
the fluid be saturated with sodium chlorid. A sheet of white paper
beneath the beaker facilitates recognition of the color change.
In clinical work the amount of acidity is expressed by the number of
cubic centimeters of the decinormal sodium hydroxid solution which
would be required to neutralize 100 c.c. of the gastric juice, each
cubic centimeter representing one _degree_ of acidity. Hence multiply
the number of cubic centimeters of decinormal solution required to
neutralize the 10 c.c. of stomach fluid by ten. This gives the number
of degrees of acidity. The amount may be expressed in terms of
hydrochloric acid, if one remember that each degree is equivalent to
0.00365 per cent. hydrochloric acid.
_Example_.--Suppose that 7 c.c. of decinormal solution were required
to bring about the end reaction in 10 c.c. gastric juice; then
7 X 10 = 70 _degrees_ of acidity; and, expressed in terms of
hydrochloric acid, 70 X 0.00365 = 0.255 _per cent._
Preparation of decinormal solutions is described in text-books on
chemistry. The practitioner will find it best to have them made by a
chemist, or to purchase from a chemic supply house.
[Illustration: PLATE X. A, Gastric fluid to which a 1 per cent.
solution of phenolphthalein has been added; B, gastric fluid to which
a 1 per cent. solution of alizarin has been added; C, gastric fluid to
which a 0.5 per cent. solution of dimethylamido-azobenzol has been
added; A', A after titration with a decinormal solution of sodium
hydroxid; B', B after titration with a decinormal solution of sodium
hydroxid; C', C after titration with a decinormal solution of sodium
hydroxid (Boston).]
* * * * *
(2) Hydrochloric Acid.--After the Ewald and Boas test-breakfasts, the
amount of free hydrochloric acid varies normally between 25 and 50
degrees, or about 0.1 to 0.2 per cent. In disease, it may go
considerably higher, or may be absent altogether.
When the amount of free hydrochloric acid is normal, organic disease
of the stomach probably does not exist.
_Increase_ of free hydrochloric acid above 50 degrees {225}
(_hyperchlorhydria_) generally indicates a neurosis, but also occurs
in most cases of gastric ulcer and beginning chronic gastritis.
_Decrease_ of free hydrochloric acid below 25 degrees
(_hypochlorhydria_) occurs in some neuroses, chronic gastritis, early
carcinoma, and most conditions associated with general systemic
depression. Marked variation in the amount at successive examinations
strongly suggests a neurosis. Too low values are often obtained at the
first examination, the patient's dread of the introduction of the tube
probably inhibiting secretion.
_Absence_ of free hydrochloric acid (_achlorhydria_) occurs in most
cases of gastric cancer and far-advanced chronic gastritis, in many
cases of pernicious anemia, and, sometimes, in hysteria.
The presence of free hydrochloric acid presupposes a normal amount of
combined hydrochloric acid, hence the combined need not be estimated
when the free acid has been found. When, however, free hydrochloric
acid is absent, it is important to know whether any acid is secreted,
and an estimation of the combined acid then becomes of great value.
The normal average after an Ewald breakfast is about 10 to 15 degrees.
* * * * *
Töpfer's Method for Free Hydrochloric Acid.--In a beaker take 10 c.c.
filtered stomach fluid and add four drops of the indicator, a 0.5 per
cent. alcoholic solution of dimethylamido-azobenzol. A red color
instantly appears if free hydrochloric acid be present. Add decinormal
sodium hydroxid solution, drop by drop from a buret, until the last
trace of red just disappears, and a canary-yellow color takes its
place (Plate X, C, C'). Read off the number of cubic centimeters of
decinormal solution added, and calculate the degrees, or {226}
percentage of free hydrochloric acid, as in Töpfer's method for total
acidity.
When it is impossible to obtain sufficient fluid for all the tests, it
will be found convenient to estimate the free hydrochloric acid and
total acidity in the same portion. After finding the free hydrochloric
acid as just described, add four drops phenolphthalein solution, and
continue the titration. The amount of decinormal solution used in both
titrations indicates the total acidity.
Töpfer's Method for Combined Hydrochloric Acid.--In a beaker take
10 c.c. filtered gastric juice and add four drops of the indicator, a
1 per cent. aqueous solution of sodium alizarin sulphonate. Titrate
with decinormal sodium hydroxid until the appearance of a
bluish-violet color which does not become deeper upon addition of
another drop (Plate X, B, B'). It is difficult, without practice, to
determine when the right color has been reached. A reddish-violet
appears first. The shade which denotes the end reaction can be
produced by adding two or three drops of the indicator to 5 c.c. of 1
per cent. sodium carbonate solution.
Calculate the number of cubic centimeters of decinormal solution which
would be required for 100 c.c. of stomach fluid. This gives, in
degrees, _all the acidity except the combined hydrochloric acid_. The
combined hydrochloric acid is then found by deducting this amount from
the total acidity, which has been previously determined.
_Example_.--Suppose that 5 c.c. of decinormal solution were required
to produce the purple color in 10 c.c. gastric juice; then
5 X 10 = 50 = _all the acidity except combined hydrochloric acid_.
Suppose, now, that the total acidity has already been found to be 70
degrees; then 70 - 50 = 20 _degrees_ of combined hydrochloric acid;
and 20 X 0.00365 = 0.073 _per cent._
* * * * *
(3) Organic Acids.--There is no simple direct quantitative method.
After the total acidity has been {227} determined, organic acids may
be removed from another portion of the gastric filtrate by shaking
thoroughly with an equal volume of neutral ether, allowing the fluids
to separate, and repeating this process until the gastric fluid has
been extracted with eight or ten times its volume of ether. The total
acidity is then determined, and the difference between the two
determinations indicates the amount of organic acids.
(4) Pepsin.--No direct method is available. The following is
sufficient for clinical purposes:
* * * * *
Hammerschlag's Method.--To the white of an egg add twelve times its
volume of 0.4 per cent. hydrochloric acid (dilute hydrochloric acid,
U.S.P., 4 c.c.; water, 96 c.c.), mix well, and filter. This gives a 1
per cent. egg-albumen solution. Take 10 c.c. of this solution in each
of three tubes or beakers. To _A_ add 5 c.c. gastric juice; to _B_,
5 c.c. water with 0.5 gm. pepsin; to _C_, 5 c.c. water only. Place in
an incubator for an hour and then determine the amount of albumin in
each mixture by Esbach's method. Tube _C_ shows the amount of albumin
in the test-solution. The difference between _C_ and _B_ indicates the
amount of albumin which would be digested by normal gastric juice. The
difference between _C_ and _A_ gives the albumin which is digested by
the fluid under examination. It has been shown that the amounts of
pepsin in two fluids are proportionate to the squares of the products
of digestion. Thus, if the amounts of albumin digested in tubes _A_
and _B_ are to each other as 2 is to 4, the amounts of pepsin are to
each other as 4 is to 16.
Certain sources of error can be eliminated by diluting the gastric
juice several times before testing.
* * * * *
{228} D. MICROSCOPIC EXAMINATION
A drop of unfiltered stomach-contents is placed upon a slide, covered
with a cover-glass, and examined with the two-thirds and one-sixth
objectives.
Under normal conditions little is to be seen except great numbers of
starch-granules, with an occasional epithelial cell, yeast-cell, or
bacterium. Starch-granules are recognized by their concentric
striations and the fact that they stain blue with iodin solutions.
[Illustration: FIG. 88.--General view of the gastric contents: _a_,
Squamous epithelial cells from esophagus and mouth; _b_, leukocytes;
_c_, cylindric epithelial cells; _d_, muscle-fibers; _e_, fat-droplets
and fat-crystals; _f_, starch-granules; _g_, chlorophyl-containing
vegetable matters; _h_, vegetable spirals; _i_, bacteria; _k_,
sarcinæ; _l_, budding (yeast) fungi (Jakob).]
Pathologically, remnants of food from previous meals, red
blood-corpuscles, pus-cells, sarcinæ, and excessive numbers of
yeast-cells and bacteria may be encountered (Fig. 88).
Remnants of food from previous meals indicate deficient gastric
motility.
Red Blood-corpuscles.--Blood is best recognized by the chemic tests
already given. The corpuscles {229} sometimes retain a fairly normal
appearance, but are generally so degenerated that only granular
pigment is left.
Pus-cells.--Pus is rarely encountered in the fluid removed after a
test-meal. Considerable numbers of pus-corpuscles have been found in
some cases of gastric cancer. Swallowed sputum must always be
considered.
Sarcinæ.--These are small spheres arranged in cuboid groups often
compared to bales of cotton. They frequently form large clumps and are
easily recognized. They stain brown with iodin solution. They signify
fermentation. Their presence is strong evidence against the existence
of gastric cancer, in which disease they rarely occur.
Yeast-cells.--As already stated, a few yeast-cells may be found under
normal conditions. The presence of considerable numbers is evidence of
fermentation. Their appearance has been described (p. 130). They stain
brown with iodin solution.
[Illustration: FIG. 89.--Boas-Oppler bacillus from case of gastric
cancer (Boston).]
Bacteria.--Numerous bacteria may be encountered, especially in the
absence of free hydrochloric acid. The _Boas-Oppler bacillus_ is the
only one of special significance. {230} It occurs in the majority of
cases of cancer, and is rarely found in other conditions. Carcinoma
probably furnishes a favorable medium for its growth.
These bacilli (Fig. 89) are large (5 to 10 µ long), non-motile, and
usually arranged end to end in chains. They stain brown with iodin
solution, which distinguishes them from _Leptothrix buccalis_ (p.
270), which is not infrequently found in stomach fluid. They also
stain by Gram's method. They are easily seen with the one-sixth
objective in unstained preparations, but are best recognized with the
one-twelfth, after drying some of the fluid upon a cover-glass,
fixing, and staining with Löffler's methylene-blue or by Gram's
method.
A few large non-motile bacilli are frequently seen; they cannot be
called Boas-Oppler bacilli unless they are numerous and show something
of the typical arrangement.
E. THE GASTRIC CONTENTS IN DISEASE
In the diagnosis of stomach disorders the practitioner must be
cautioned against relying too much upon examinations of the
stomach-contents. A first examination is especially unreliable. Even
when repeated examinations are made, the laboratory findings must
never be considered apart from the clinical signs.
The more characteristic findings in certain disorders are suggested
here.
1. Dilatation of the Stomach.--Evidences of retention and fermentation
are the chief characteristics of this condition. Hydrochloric acid is
commonly diminished. Pepsin may be normal or slightly diminished.
Lactic acid may be detected in small amounts, but is usually absent
when the stomach has been washed before giving the {231} test-meal.
Both motility and absorptive power are deficient. The microscope
commonly shows sarcinæ, bacteria, and great numbers of yeast-cells.
Remnants of food from previous meals can be detected with the naked
eye or microscopically.
2. Gastric Neuroses.--The findings are variable. Successive
examinations may show normal, increased, or diminished hydrochloric
acid, or even entire absence of the free acid. Pepsin is usually
normal.
In the neurosis characterized by continuous hypersecretion
(gastrosuccorrhea), 40 c.c. or more of gastric juice can be obtained
from the fasting stomach. Should the fluid contain food-particles, it
is probably the result of retention, not hypersecretion.
3. Chronic Gastritis.--Free hydrochloric acid may be increased in
early cases. It is generally diminished in well-marked cases, and is
often absent in advanced cases. Lactic acid is often present in
traces, rarely in notable amount. Secretion of pepsin and rennin is
always diminished in marked cases. Mucus is frequently present, and is
very significant of the disease. Motility and absorption are generally
deficient. Small fragments of mucous membrane may be found, and when
examined by a pathologist, may occasionally establish the diagnosis.
4. Achylia Gastrica (Atrophic Gastritis).--This condition may be a
terminal stage of chronic gastritis. It is sometimes associated with
the blood-picture of pernicious anemia. It gives a great decrease, and
sometimes entire absence of hydrochloric acid and ferments. The total
acidity may be as low as 1 or 2 degrees. Small amounts of lactic acid
may be present. Absorption and motility are usually not affected.
{232} 5. Gastric Carcinoma.--As far as the laboratory examination
goes, the cardinal signs of this disease are absence of free
hydrochloric acid and presence of lactic acid and of the Boas-Oppler
bacillus. These findings are, however, by no means constant.
It is probable that some substance is produced by the cancer which
neutralizes the free hydrochloric acid, and thus causes it to
disappear earlier than in other organic diseases of the stomach.
The presence of lactic acid is the most suggestive single symptom of
gastric cancer. In the great majority of cases its presence in notable
amount (0.1 per cent. by Strauss' method) after Boas' breakfast, the
stomach having been washed the evening before, warrants a diagnosis of
malignancy.
Carcinoma seems to furnish an especially favorable medium for the
growth of the Boas-Oppler bacillus, hence this micro-organism is
frequently present.
Blood can be detected in the stomach fluid by the chemic tests in
nearly one-half of the cases, and is more common when the newgrowth is
situated at the pylorus. Blood is present in the stool in nearly every
case.
Evidences of retention and fermentation are the rule in pyloric
cancer. Tumor particles are sometimes found late in the disease.
6. Gastric Ulcer.--There is excess of free hydrochloric acid in about
one-half of the cases. In other cases the acid is normal or
diminished. Blood is often present. The diagnosis must be based
largely upon the clinical symptoms, and where ulcer is strongly
suspected, it is probably unwise to use the stomach-tube.
{233} II. ADDITIONAL EXAMINATIONS WHICH GIVE INFORMATION AS TO THE
CONDITION OF THE STOMACH
1. Absorptive Power of the Stomach.--This is a very unimportant
function, only a few substances being absorbed in the stomach. It is
delayed in most organic diseases of the stomach, especially in
dilatation and carcinoma, but not in neuroses. The test has little
practical value.
* * * * *
Give the patient, upon an empty stomach, a three-grain capsule of
potassium iodid with a glass of water, taking care that none of the
drug adheres to the outside of the capsule. At intervals test the
saliva for iodids by moistening starch-paper with it and touching with
yellow nitric acid. A blue color shows the presence of an iodid, and
appears normally in ten to fifteen minutes after ingestion of the
capsule. A longer time denotes delayed absorption.
_Starch paper_ is prepared by soaking filter-paper in boiled starch
and drying.
* * * * *
2. Motor Power of the Stomach.--This refers to the rapidity with which
the stomach passes its contents on into the intestine. It is very
important: intestinal digestion can compensate for insufficient or
absent stomach digestion only so long as the motor power is good.
Motility is impaired to some extent in chronic gastritis. It is
especially deficient in dilatation of the stomach due to atony of the
gastric wall or to pyloric obstruction, either benign or malignant. It
is increased in most conditions with hyperchlorhydria.
The best evidence of deficient motor power is the detection of food in
the stomach at a time when it should be empty, _e.g._, before
breakfast in the morning. When more than 60 c.c. of fluid are obtained
with the tube one hour after a Ewald breakfast, deficient motility may
be inferred.
* * * * *
{234} Ewald's salol test is scarcely so reliable as the above. It
depends upon the fact that salol is not absorbed until it reaches the
intestine and is decomposed by the alkaline intestinal juices.
The patient is given 15 grains of salol with a test-breakfast, and the
urine, passed at intervals thereafter, is tested for salicyluric acid.
A few drops of 10 per cent. ferric chlorid solution are added to a
small quantity of the urine. A violet color denotes the presence of
salicyluric acid. It appears normally in sixty to seventy-five minutes
after ingestion of the salol. A longer time indicates impaired motor
power.
* * * * *
3. To Determine Size and Position of Stomach.--After removing the
test-meal, while the tube is still in place, force quick puffs of air
into the stomach by compression of the bulb. The puffs can be clearly
heard with a stethoscope over the region of the stomach, and nowhere
else.
If desired, the patient may be given a dram of sodium bicarbonate in
solution, followed immediately by the same amount of tartaric acid,
also in solution; or he may take the two parts of a seidlitz powder
separately. The carbon dioxid evolved distends the stomach, and its
outline can easily be determined by percussion.
{235}