jaundice, often some days before the skin becomes yellow; and in many
disorders of the liver not severe enough to cause jaundice. It also
occurs in diseases with extensive and rapid destruction of red
blood-corpuscles. Both bile-pigment and bile acids may be found. They
generally occur together, but the pigment is not infrequently present
alone. Bilirubin, only, occurs in freshly voided urine, the other
pigments (biliverdin, bilifuscin, etc.) being produced from this by
oxidation as the urine stands. The acids are almost never present
without the pigments, and are, therefore, seldom tested for
clinically.
_Detection of Bile-pigment_.--Bile-pigment gives the urine a
greenish-yellow, yellow, or brown color, which upon shaking is
imparted to the foam. Cells, casts, and other structures in the
sediment may be stained brown or yellow. This, however, should not be
accepted as proving the presence of bile without further tests.
* * * * *
(1) Smith's Test.--Overlay the urine with tincture of iodin diluted
with nine times its volume of alcohol. An emerald-green ring at the
zone of contact shows the presence of bile-pigments. It is convenient
to use a conical test-glass, one side of which is painted white.
(2) Gmelin's Test.--This consists in bringing slightly yellow nitric
acid into contact with the urine. A play of colors, of which green and
violet are most distinctive, denotes the presence of bile-pigment.
Colorless nitric add will become yellow upon standing in the sunlight.
The test may be applied {88} in various ways: by overlaying the acid
with the urine; by bringing a drop of each together upon a porcelain
plate; by filtering the urine through thick filter-paper, and touching
the paper with a drop of the acid; and, probably best of all, by
precipitating with lime-water, filtering, and touching the precipitate
with a drop of the acid.
* * * * *
_Detection of Bile Acids_.--Hay's test is simple, sensitive, and
fairly reliable, and will, therefore, appeal to the practitioner. It
depends upon the fact that bile acids lower surface tension. Other
tests require isolation of the acids for any degree of accuracy.
* * * * *
Hay's Test.--Upon the surface of the urine, which must not be warm,
sprinkle a little finely powdered sulphur. If it sinks at once, bile
acids are present to the amount of 0.01 per cent. or more; if only
after gentle shaking, 0.0025 per cent. or more. If it remains
floating, even after gentle shaking, bile acids are absent.
* * * * *
5. Hemoglobin.--The presence in the urine of hemoglobin or pigments
directly derived from it, accompanied by few, if any, red corpuscles,
constitutes _hemoglobinuria_. It is a rare condition, and must be
distinguished from _hematuria_, or _blood_ in the urine, which is
common. In both conditions chemic tests will show hemoglobin, but in
the latter the microscope will reveal the presence of red corpuscles.
Urines which contain notable amounts of hemoglobin have a reddish or
brown color, and may deposit a sediment of brown, granular pigment.
Hemoglobinuria occurs when there is such extensive destruction of red
blood-cells within the body that the liver cannot transform all the
hemoglobin set free into bile-pigment. The most important examples are
seen in {89} poisoning, as by mushrooms and potassium chlorate, in
malignant malaria (blackwater fever), and in the obscure condition
known as "paroxysmal hemoglobinuria." This last is characterized by
the appearance of large quantities of hemoglobin at intervals, usually
following exposure to cold, the urine remaining free from hemoglobin
between the attacks.
_Detection_.--Teichmann's test (p. 202) may be applied to the
precipitate after boiling and filtering, but the guaiac test is more
convenient in routine work.
* * * * *
Guaiac Test.--Mix equal parts of "ozonized" turpentine and fresh
tincture of guaiac which has been diluted with alcohol to a light
sherry-wine color. In a test-tube or conical glass overlay the urine
with this mixture. A bright blue ring will appear at the zone of
contact within a few minutes if hemoglobin be present. The guaiac
should be kept in an amber-colored bottle. Fresh turpentine can be
"ozonized" by allowing it to stand a few days in an open vessel in the
sunlight.
This test is very sensitive, and a negative result proves the absence
of hemoglobin. Positive results are not conclusive, because numerous
other substances--few of them likely to be found in the urine--may
produce the blue color. That most likely to cause confusion is pus,
but the blue color produced by it disappears upon heating. The thin
film of copper often left in a test-tube after testing for sugar may
give the reaction, as may also the fumes from an open bottle of
bromin.
* * * * *
6. Diazo Substances.--Certain unknown substances sometimes present in
the urine give a characteristic color reaction--the "diazo reaction"
of Ehrlich--when treated with diazo-benzol-sulphonic acid and ammonia.
This reaction has much clinical value provided its limitations {90} be
recognized. It is at best an empirical test and must be interpreted in
the light of clinical symptoms. Although it has been met with in a
considerable number of diseases, its usefulness is practically limited
to typhoid fever, tuberculosis, and measles.
(1) Typhoid Fever.--Practically all cases give a positive reaction,
which varies in intensity with the severity of the disease. It is so
constantly present that it may be said to be "negatively
pathognomonic": if negative at a stage of the disease when it should
be positive, typhoid is almost certainly absent. Upon the other hand,
a reaction when the urine is highly diluted (1:50 or more) has much
positive diagnostic value, since this dilution prevents the reaction
in most conditions which might be mistaken for typhoid; but it should
be noted that mild cases of typhoid may not give it at this dilution.
Ordinarily the diazo appears a little earlier than the Widal
reaction--about the fourth or fifth day--but it may be delayed. In
contrast to the Widal, it begins to fade about the end of the second
week, and soon thereafter entirely disappears. An early disappearance
is a favorable sign. It reappears during a relapse, and thus helps to
distinguish between a relapse and a complication, in which it does not
reappear.
(2) Tuberculosis.--The diazo reaction has been obtained in many forms
of the disease. It has little or no diagnostic value. Its continued
presence in pulmonary tuberculosis is, however, a grave prognostic
sign, even when the physical signs are slight. After it once appears
it generally persists more or less intermittently until death, the
average length of life after its appearance being about six months.
The reaction is often temporarily present in {91} mild cases during
febrile complications, and has then no significance.
(3) Measles.--A positive reaction is frequently obtained in measles,
and may help to distinguish this disease from German measles, in which
it does not occur.
* * * * *
Technic.--Although the test is really a very simple one, careful
attention to technic is imperative. Many of the early workers were
very lax in this regard. Faulty technic and failure to record the
stage of the disease in which the tests were made have probably been
responsible for the bulk of the conflicting results reported.
Certain drugs often given in tuberculosis and typhoid interfere with
or prevent the reaction. The chief are creosote, tannic acid and its
compounds, opium and its alkaloids, salol, phenol, and the iodids. The
reagents are:
(1) Saturated solution sulphanilic acid in 5 per cent. hydrochloric
acid.
(2) 0.5 per cent. aqueous solution sodium nitrite.
(3) Strong ammonia.
Mix forty parts of (1) and one part of (2). In a test-tube take equal
parts of this mixture and the urine, and pour 1 or 2 c.c. of the
ammonia upon its surface. If the reaction be positive, a garnet ring
will form at the junction of the two fluids; and upon shaking, a
distinct pink color will be imparted to the foam. The color of the
foam is the essential feature. If desired, the mixture may be well
shaken before the ammonia is added: the pink color will then instantly
appear in that portion of the foam which the ammonia has reached, and
can be readily seen. The color varies from eosin-pink to deep crimson,
depending upon the intensity of the reaction. A doubtful reaction
should be considered negative.
* * * * *
7. Pancreatic Reaction.--Cammidge has shown that in cases of
pancreatitis a substance capable of forming {92} crystals with
phenylhydrazin can be developed by boiling the urine with a mineral
acid, and has offered the following test as an aid in diagnosis of
this obscure condition. The nature both of this substance and the
antecedent substance from which it is derived is not known. As
originally proposed, the test was complicated and probably not
trustworthy, but with his improved and simplified technic, Cammidge
has had very promising results. In 200 consecutive examinations in
which the diagnosis was confirmed, _postmortem_ or at operation, 67
cases of pancreatitis (65 chronic, 2 acute) gave positive reactions; 4
cases of cancer of the pancreas were positive, 12 negative; 4 cases in
which no pancreatitis was found were positive, 113 were negative.
Normal urines do not give the reaction. The difficulty and importance
of diagnosis in pancreatitis warrant inclusion of the method here even
though its true value cannot be definitely assigned. While the test is
somewhat tedious, all the manipulations are simple and require no
apparatus but flasks, test-tubes, and funnels.
* * * * *
Technic.--Careful attention to detail is imperative. An ordinary
routine examination is first made. Albumin and sugar, if present, must
be removed: the former, by acidifying with acetic acid, boiling, and
filtering; the latter, by fermentation with yeast after the first step
of the method proper. An alkaline urine should be made slightly acid
with hydrochloric acid.
(1) Forty cubic centimeters of the urine, which has been rendered
perfectly clear by repeated filtration through the same filter-paper,
are placed in a small flask, treated with 1 c.c. concentrated
hydrochloric acid and gently boiled on a sand-bath for ten minutes, a
funnel with long stem being placed in the neck of the flask to act as
a condenser (Fig. 28). After {93} boiling, the urine is cooled in a
stream of cold water and brought to its original bulk with distilled
water; 8 gm. of lead carbonate are then added to neutralize the acid.
The fluid is allowed to stand a few minutes and then filtered through
well-moistened fine-grained filter-paper until perfectly clear.
[Illustration: FIG. 28.--"Pancreatic reaction" flasks fitted with
funnel condensers on a sand-bath (Robson and Cammidge).]
(2) The filtrate is shaken up with 8 gm. powdered tribasic lead
acetate and filtered. The excess of lead is then removed by passing
hydrogen sulphid gas through the fluid or by shaking well with 4 gm.
finely powdered sodium sulphate, heating to boiling, cooling to as low
a temperature as possible in a stream of water, and filtering as
before until perfectly clear.
(3) Ten cubic centimeters of the filtrate are then made up to 17 c.c.
with distilled water, and added to a mixture of 0.8 gm. phenylhydrazin
hydrochlorate, 2 gm. powdered sodium acetate, and 1 c.c. 50 per cent.
acetic acid in a small flask {94} with funnel condenser. This is
boiled on a sand-bath for ten minutes, and filtered while hot through
filter-paper moistened with hot water into a test-tube with a 15 c.c.
mark. Should the filtrate not reach this mark, make up to 15 c.c. with
hot distilled water. Allow to cool slowly.
(4) In well-marked cases of pancreatitis a yellow precipitate appears
within a few hours; in milder cases, it may not appear for twelve
hours. The microscope shows this sediment to consist of "long, light
yellow, flexible, hair-like crystals arranged in sheaves, which, when
irrigated with 33 per cent. sulphuric acid, melt away and disappear in
ten to fifteen seconds after the acid first touches them" (Fig. 29).
[Illustration: FIG. 29.--Improved "pancreatic reaction." Crystals
obtained from a case of chronic pancreatitis with gall-stones in the
common duct (X200) (from a photo by P. J. Cammidge).]
(5) To exclude traces of glucose which might be overlooked in the
preliminary examination a control test should be carried out in the
same manner with omission of step (1).
* * * * *
{95} 8. Drugs.--The effect of various drugs upon the color of the
urine has been mentioned (p. 50). Most poisons are eliminated in the
urine, but their detection is more properly discussed in works upon
toxicology. A few drugs which are of interest to the practitioner, and
which can be detected by comparatively simple methods, are mentioned
here.
Acetanilid and Phenacetin.--The urine is evaporated by gentle heat to
about half its volume, boiled for a few minutes with about one-fifth
its volume of strong hydrochloric acid, and shaken out with ether. The
ether is evaporated, the residue dissolved in water, and the following
test applied: To about 10 c.c. are added a few cubic centimeters of 3
per cent. phenol, followed by a weak solution of chromium trioxid
(chromic acid) drop by drop. The fluid assumes a red color, which
changes to blue when ammonia is added. If the urine is very pale,
extraction with ether may be omitted.
Antipyrin.--This drug gives a dark-red color when a few drops of 10
per cent. ferric chlorid are added to the urine. The color does not
disappear upon boiling, which excludes diacetic acid.
Arsenic.--_Reinsch's Test_.--Add to the urine in a test-tube or small
flask about one-seventh its volume of hydrochloric acid, introduce a
piece of bright copper-foil about one-eighth-inch square, and boil for
several minutes. If arsenic be present, a dark-gray film is deposited
upon the copper. The test is more delicate if the urine be
concentrated by slow evaporation. This test is well known and is
widely used, but is not so reliable as the following:
_Gutzeit's Test_.--In a large test-tube place a little {96}
arsenic-free zinc, and add 5 to 10 c.c. pure dilute hydrochloric acid
and a few drops of iodin solution (Gram's solution will answer), then
add 5 to 10 c.c. of the urine. At once cover the mouth of the tube
with a filter-paper cap moistened with saturated aqueous solution of
silver nitrate (1:1). If arsenic be present, the paper quickly becomes
lemon-yellow, owing to formation of a compound of silver arsenid and
silver nitrate, and turns black when touched with a drop of water. To
make sure that the reagents are arsenic-free, the paper cap may be
applied for a few minutes before the urine is added.
Atropin will cause dilatation of the pupil when a few drops of the
urine are placed in the eye of a cat or rabbit.
Bromids can be detected by acidifying about 10 c.c. of the urine with
dilute sulphuric acid, adding a few drops of fuming nitric acid and a
few cubic centimeters of chloroform, and shaking. In the presence of
bromin the chloroform, which settles to the bottom, assumes a yellow
color.
Iodin--from ingestion of iodids or absorption from iodoform
dressings--is tested for in the same way as the bromids, the
chloroform assuming a pink to reddish-violet color. To detect traces,
a large quantity of urine should be rendered alkaline with sodium
carbonate and greatly concentrated by evaporation before testing.
Lead.--No simple method is sufficiently sensitive to detect the traces
of lead which occur in the urine in chronic poisoning. Of the more
sensitive methods, that of Arthur Lederer is probably best suited to
the practitioner:
It is essential that all apparatus used be lead-free. Five hundred
cubic centimeters of the urine are acidified {97} with 70 c.c. pure
sulphuric acid, and heated in a beaker or porcelain dish. About 20 to
25 gm. of potassium persulphate are added a little at a time. This
should decolorize the urine, leaving it only slightly yellow. If it
darkens upon heating, a few more crystals of potassium persulphate are
added, the burner being first removed to prevent boiling over; if it
becomes cloudy, a small amount of sulphuric acid is added. It is then
boiled until it has evaporated to 250 c.c. or less. After cooling, an
equal volume of alcohol is added, and the mixture allowed to stand in
a cool place for four or five hours, during which time all the lead
will be precipitated as insoluble sulphate.
The mixture is then filtered through a small, close-grained
filter-paper (preferably an ashless, quantitative filter-paper), and
any sediment remaining in the beaker or dish is carefully washed out
with alcohol and filtered. A test-tube is placed underneath the
funnel; a hole is punched through the tip of the filter with a small
glass rod, and all the precipitate (which may be so slight as to be
scarcely visible) washed down into the test-tube with a jet of
distilled water from a wash-bottle, using as little water as possible.
Ten cubic centimeters will usually suffice. This fluid is then heated,
adding crystals of sodium acetate until it becomes perfectly clear. It
now contains all the lead of the 500 c.c. urine in the form of lead
acetate. It is allowed to cool, and hydrogen sulphid gas is passed
through it for about five minutes. The slightest yellowish-brown
discoloration indicates the presence of lead. A very slight
discoloration can be best seen when looked at from above. For
comparison, the gas may be passed through a test-tube containing an
equal amount of distilled water. The quantity of lead can be {98}
determined by comparing the discoloration with that produced by
passing the gas through lead acetate (sugar of lead) solutions of
known strength. One part of lead acetate crystals contains 0.54 part
of lead. Hydrogen sulphid is easily prepared in the simple apparatus
shown in Fig. 30. A small quantity of iron sulphid is placed in the
test-tube; a little dilute hydrochloric acid is added; the cork is
replaced; and the delivery tube is inserted to the bottom of fluid to
be tested.
[Illustration: FIG. 30.--A simple hydrogen sulphid generator.]
Mercury.--Traces can be detected in the urine for a considerable time
after the use of mercury compounds by ingestion or inunction.
About a liter of urine is acidified with 10 c.c. hydrochloric acid,
and a small piece of copper-foil or gauze is introduced. This is
gently heated for an hour, and allowed to stand for twenty-four hours.
The metal is then removed, and washed successively with very dilute
sodium hydroxid solution, alcohol, and ether. When dry, {99} it is
placed in a long, slender test-tube, and the lower portion of the tube
is heated to redness. If mercury be present, it will volatilize and
condense in the upper portion of the tube as small, shining globules
which can be seen with a hand-magnifier or low power of the
microscope. If, now, a crystal of iodin be dropped into the tube and
gently heated, the mercury upon the side of the tube is changed first
to the yellow iodid and later to the red iodid which are recognized by
their color.
Morphin.--Add sufficient ammonia to the urine to render it distinctly
ammoniacal, and shake thoroughly with a considerable quantity of pure
acetic ether. Separate the ether and evaporate to dryness. To a little
of the residue in a watch-glass or porcelain dish add a few drops of
formaldehyd-sulphuric acid, which has been freshly prepared by adding
one drop of formalin to 1 c.c. pure concentrated sulphuric acid. If
morphin be present, this will produce a purple-red color, which
changes to violet, blue-violet, and finally nearly pure blue.
Phenol.--As has been stated, the urine following phenol poisoning
turns olive-green and then brownish-black upon standing. Tests are of
value in recognizing poisoning from ingestion and in detecting
absorption from carbolized dressings.
The urine is acidulated with hydrochloric acid and distilled. To the
first few cubic centimeters of distillate is added 10 per cent.
solution of ferric chlorid drop by drop. The presence of phenol causes
a deep amethyst-blue color, as in Uffelmann's test for lactic acid.
Phenolphthalein, which is now being used as a cathartic under the name
of _purgen_, gives a bright pink color when the urine is rendered
alkaline with caustic soda.
{100} Quinin.--A considerable quantity of the urine is rendered
alkaline with ammonia and extracted with ether; the ether is
evaporated, and a portion of the residue dissolved in about twenty
drops of dilute alcohol. The alcoholic solution is acidulated with
dilute sulphuric acid, a drop of an alcoholic solution of iodin
(tincture of iodin diluted about ten times) is added, and the mixture
is warmed. Upon cooling, an iodin compound of quinin (herapathite)
will separate out in the form of a microcrystalline sediment of green
plates.
The remainder of the residue may be dissolved in a little dilute
sulphuric acid. This solution will show a characteristic blue
fluorescence when quinin is present.
Resinous drugs cause a white precipitate like that of albumin when
strong nitric acid is added to the urine. This is dissolved by
alcohol.
Salicylates, salol, and similar drugs give a bluish-violet color,
which disappears upon heating, upon addition of a few drops of 10 per
cent. ferric chlorid solution. When the quantity of salicylates is
small, the urine may be acidified with hydrochloric acid and extracted
with ether, the ether evaporated, and the test applied to an aqueous
solution of the residue.
Tannin and its compounds appear in the urine as gallic acid, and the
urine becomes greenish-black (inky, if much gallic acid be present)
when treated with a solution of ferric chlorid.
III. MICROSCOPIC EXAMINATION
A careful microscopic examination will often detect structures of
great diagnostic importance in urine which seems perfectly clear, and
from which only very slight {101} sediment can be obtained with the
centrifuge. Upon the other hand, cloudy urines with abundant sediment
are often shown by the microscope to contain nothing of clinical
significance.
Since the nature of the sediment soon changes, the urine must be
examined while fresh, preferably within six hours after it is voided.
The sediment is best obtained by means of the centrifuge. If a
centrifuge is not available, the urine may be allowed to stand in a
conical test-glass for six to twenty-four hours after adding some
preservative (p. 48). The "torfuge" (Fig. 31) is said to be a very
satisfactory substitute for the centrifuge, and is readily portable.
[Illustration: FIG. 31.--Wetherill's torfuge.]
A small amount of the sediment should be transferred to a slide by
means of a pipet. It is very important to do this properly. The best
pipet is a small glass tube which has been drawn out at one end to a
tip with rather small opening. The tube or glass containing the
sediment is held on a level with the eye, the larger end of the pipet
is closed with the index-finger, which must be dry, and the {102} tip
is carried down into the sediment. By carefully loosening the finger,
but not entirely removing it, a small amount of the sediment is then
allowed to run slowly into the pipet. Slightly rotating the pipet will
aid in accomplishing this. After wiping off the urine which adheres to
the outside, a drop from the pipet is placed upon a clean slide. A
hair is then placed in the drop and a large cover-glass applied. Many
workers use no cover. This offers a thicker layer and larger area of
urine, the chance of finding scanty structures being proportionately
increased. It has the disadvantage that any jarring of the room (as by
persons walking about) sets the microscopic field into vibratory
motion and makes it impossible to see anything clearly; and, since it
does not allow of the use of high-power objectives, one cannot examine
details as one often wishes to do. A large cover-glass with a hair
beneath it avoids these disadvantages, and gives enough urine to find
any structures which are present in sufficient number to have clinical
significance, provided other points in the technic have been right. It
is best, however, to examine several drops; and, when the sediment is
abundant, drops from the upper and lower portions should be examined
separately.
In examining urinary sediments microscopically no fault is so common,
nor so fatal to good results, as improper illumination (see Figs. 2
and 3), and none is so easily corrected. The light must be central and
very subdued. The two-thirds objective should be used as a finder,
while the one-sixth is reserved for examining details.
It is well to emphasize that _the most common errors which result in
failure to find important structures, when present, are lack of care
in transferring the sediment to the slide, too strong illumination,
and too great magnification_.
{103} In order to distinguish between similar structures it is often
necessary to watch the effect upon them of certain reagents. This is
especially true of the various unorganized sediments. They very
frequently cannot be identified from their form alone. With the
structures still in focus, a drop of the reagent may be placed at one
edge of the cover-glass and drawn underneath it by the suction of a
piece of blotting-paper touched to the opposite edge; or a small drop
of the reagent and of the urine may be placed close together upon a
slide and a cover gently lowered over them. As the two fluids mingle,
the effect upon various structures may be seen.
Urinary sediments may be studied under three heads: A. Unorganized
sediments. B. Organized sediments. C. Extraneous structures.
A. UNORGANIZED SEDIMENTS
In general these have little diagnostic or prognostic significance.
Most of them are substances normally present which have been
precipitated from solution either because present in excessive amounts
or, more frequently, because of some alteration in the urine (as in
reaction, concentration, etc.) which may be purely physiologic,
depending upon changes in diet or habits. Various substances are
always precipitated during decomposition, which may take place either
within or without the body. Unorganized sediments may be classified
according to the reaction of the urine in which they are most likely
to be found:
In acid urine: uric acid, amorphous urates, sodium urate, calcium
oxalate, leucin and tyrosin, cystin, and fat-globules. Uric acid, the
urates, and calcium oxalate are {104} the common deposits of acid
urines; the others are less frequent, and depend less upon the
reaction of the urine.
In alkaline urine: phosphates, calcium carbonate, and ammonium urate.
Other crystalline sediments (Fig. 32) which are rare and require no
further mention are: calcium sulphate, cholesterin, hippuric acid,
hematoidin, fatty acids, and indigo.
[Illustration: FIG. 32.--Unusual urinary crystals (drawn from various
authors): 1, Calcium sulphate (colorless); 2, cholesterin (colorless);
3, hippuric acid (colorless); 4, hematoidin (brown); 5, fatty acids
(colorless); 6, indigo (blue); 7, sodium urate (yellowish).]
1. In Acid Urine.--(1) Uric-acid Crystals.--These crystals are the red
grains--"gravel" or "red sand"--which are often seen adhering to the
sides and bottom of a vessel containing urine. Microscopically, they
are yellow or reddish-brown crystals, which differ greatly in size and
shape. The most characteristic forms (Plate III and Fig. 33) are
"whetstones"; roset-like clusters of prisms and whetstones; and
rhombic plates, which have usually a paler color than the other forms
and are sometimes colorless. Recognition of the crystals depends less
upon their shape than upon their color, the reaction of the urine, and
the facts that they are soluble in caustic soda solution and insoluble
in hydrochloric or acetic acid. {105} When ammonia is added, they
dissolve and crystals of ammonium urate appear.
[Illustration: PLATE III. Uric-acid crystals with amorphous urates
(after Peyer).]
[Illustration: FIG. 33.--Forms of uric acid: 1, Rhombic plates; 2,
whetstone forms; 3, 3, quadrate forms; 4, 5, prolonged into points; 6,
8, rosets; 7, pointed bundles; 9, barrel forms precipitated by adding
hydrochloric acid to urine (Ogden).]
A deposit of uric-acid crystals has no significance unless it occurs
before or very soon after the urine is voided. Every urine, if kept
acid, will in time deposit its uric acid. Factors which favor an early
deposit are high acidity, diminished urinary pigments, and excessive
excretion of uric acid. The chief clinical interest of the crystals
lies in their tendency to form calculi, owing to the readiness with
which they collect about any solid object. Their presence in the
freshly voided urine in clusters of crystals suggests stone in the
kidney or bladder, especially if blood is also present (see Fig. 62).
(2) Amorphous Urates.--These are chiefly urates of {106} sodium and
potassium which are thrown out of solution as a yellow or red
"brick-dust" deposit. In pale urines this sediment is almost white. It
disappears upon heating. A deposit of amorphous urates is very common
in concentrated and strongly acid urines, especially in cold weather,
and has no clinical significance. Under the microscope it appears as
fine yellowish granules, often so abundant as to obscure all other
structures (Plate III). In such cases the urine should be warmed
before examining. Amorphous urates are readily soluble in caustic soda
solutions. When treated with hydrochloric or acetic acid they slowly
dissolve and rhombic crystals of uric acid appear.
Rarely, sodium urate occurs in crystalline form--slender prisms,
arranged in fan- or sheaf-like structures (Fig. 32).
(3) Calcium Oxalate.--Characteristic of calcium oxalate are colorless,
glistening, octahedral crystals, giving the appearance of small
squares crossed by two intersecting diagonal lines--the so-called
"envelop crystals" (Fig. 47). They vary greatly in size, being
sometimes so small as to seem mere points of light with medium-power
objectives. Unusual forms, which, however, seldom occur except in
conjunction with the octahedra, are colorless dumb-bells, spheres, and
variations of the octahedra (Fig. 34). The spheres might be mistaken
for globules of fat or red blood-corpuscles. Crystals of calcium
oxalate are insoluble in acetic acid or caustic soda. They are
dissolved by strong hydrochloric acid, and recrystallize as octahedra
upon addition of ammonia. They are sometimes encountered in alkaline
urine.
[Illustration: FIG. 34.--Various forms of calcium oxalate crystals
(Ogden).]
The crystals are commonly found in the urine after ingestion of
vegetables rich in oxalic acid, as tomatoes, {107} spinach, asparagus,
and rhubarb. They have no definite significance pathologically. They
often appear in digestive disturbances, in neurasthenia, and when the
oxidizing power of the system is diminished. Like uric acid, their
chief clinical interest lies in their tendency to form calculi, and
their presence in fresh urine, together with evidences of renal or
cystic irritation, should be viewed with suspicion, particularly if
they are clumped in small masses.
(4) Leucin and Tyrosin.---Crystals are deposited only when the
substances are present in considerable amount. When present in smaller
amount, they will usually be deposited if a drop of the urine be
slowly evaporated upon a slide. They generally appear together, and
are of rare occurrence, usually indicating severe fatty destruction of
the liver, such as occurs in acute yellow atrophy and
phosphorus-poisoning.
The crystals cannot be identified from their morphology alone, since
other substances, notably calcium phosphate (Fig. 38) and ammonium
urate, may take similar or identical forms.
_Leucin crystals_ (Fig. 35) are slightly yellow, oily-looking spheres,
many of them with radial and concentric {108} striations. Some may be
merged together in clusters. They are not soluble in hydrochloric acid
nor in ether.
[Illustration: FIG. 35.--Leucin spheres and tyrosin needles
(Stengel).]
_Tyrosin_ crystallizes in very fine colorless needles, usually
arranged in sheaves, with a marked constriction at the middle (Fig.
35). It is soluble in ammonia and hydrochloric acid, but not in acetic
acid.
[Illustration: FIG. 36.--Cystin crystals from urine of patient with
cystin calculus (X250).]
(5) Cystin crystals are colorless, highly refractive, rather thick,
hexagonal plates with well-defined edges. They lie either singly or
superimposed to form more or less irregular clusters (Fig. 36). Uric
acid sometimes {109} takes this form and must be excluded. Cystin is
soluble in hydrochloric acid, insoluble in acetic; it is readily
soluble in ammonia and recrystallizes upon addition of acetic acid.
Cystin crystals are very rare, and when found, point to cystin
calculus.
(6) Fat-globules.--Fat appears in the urine as highly refractive
globules of various sizes, frequently very small. These globules are
easily recognized from the fact that they are stained black by osmic
acid and red by Sudan III. The stain may be applied upon the slide, as
already described (p. 103). Osmic acid should be used in 1 per cent.
aqueous solution; Sudan III in saturated solution in 70 per cent.
alcohol.
Fat in the urine is usually a contamination from unclean vessels,
oiled catheters, etc. A very small amount may be present after
ingestion of large quantities of cod-liver oil or other fats. In fatty
degeneration of the kidney, as in phosphorus-poisoning and chronic
parenchymatous nephritis, fat-globules are commonly seen, both free in
the urine and embedded in cells and tube-casts.
In _chyluria_, or admixture of chyle with the urine as a result of
rupture of a lymph-vessel, minute droplets of fat are so numerous as
to give the urine a milky appearance. Chyluria occurs most frequently
as a symptom of infection by _Filaria sanguinis hominis_.
2. In Alkaline Urine.--(1) Phosphates.--While most common in alkaline
urine, phosphates are sometimes deposited in neutral or feebly acid
urines. The usual forms are: (_a_) Ammoniomagnesium phosphate
crystals; (_b_) acid calcium phosphate crystals; and (_c_) amorphous
phosphates. All are readily soluble in acetic acid.
(_a_) _Ammoniomagnesium Phosphate Crystals_.--They are {110} the
common "triple phosphate" crystals, which are generally easily
recognized (Figs. 37 and 63, and Plate IV). They are colorless, except
when bile-stained. Their usual form is some modification of the prism,
with oblique ends. Most typical are the well-known "coffin-lid" and
"hip-roof" forms. The long axis of the hip-roof crystal is often so
shortened that it resembles the envelop crystal of calcium oxalate. It
does not, however, have the same luster; this, and its solubility in
acetic acid, will always prevent confusion.
[Illustration: FIG. 37.--Various forms of triple-phosphate crystals
(Ogden).]
When rapidly deposited, as by artificial precipitation, triple
phosphate often takes feathery, star- or leaf-like forms. These
gradually develop into the more common prisms. X-forms may be produced
by partial solution of prisms.
(_b_) _Acid Calcium Phosphate Crystals_.--In feebly add, neutral, or
feebly alkaline urines acid calcium phosphate, wrongly called "neutral
calcium phosphate," is not infrequently deposited in the form of
colorless prisms {111} arranged in stars and rosets (Fig. 38, 1). The
individual prisms are usually slender, with one beveled, wedge-like
end, but are sometimes needle-like. They may sometimes take forms
resembling tyrosin (Fig. 38, 2), calcium sulphate, or hippuric acid,
but are readily distinguished by their solubility in acetic acid.
Calcium phosphate often forms large, thin, irregular, usually
granular, colorless plates, which are easily recognized (Fig. 38, 3).
[Illustration: FIG. 38.--Crystals of calcium phosphate: 1, Common form
(copied from Rieder's Atlas); 2, needles resembling tyrosin (drawn
from nature); 3, large, irregular plates (from nature).]
(_c_) _Amorphous Phosphates_.--The earthy phosphates are thrown out of
solution in most alkaline and many neutral urines as a white,
amorphous sediment, which may be mistaken for pus macroscopically.
Under the microscope the sediment is seen to consist of numerous
colorless granules, distinguished from amorphous urates by their
color, their solubility in acetic acid, and the reaction of the urine.
The various phosphatic deposits frequently occur together. They are
sometimes due to excessive excretion of phosphoric acid, but usually
merely indicate that the urine has become, or is becoming, alkaline.
{112} (2) Calcium carbonate may sometimes be mingled with the
phosphate deposits, usually as amorphous granules, or, more rarely, as
colorless spheres and dumb-bells, Fig. 39, which are soluble in acetic
acid with gas-formation.
[Illustration: FIG. 39.--Indistinct crystalline sediment (dumb-bell
crystals) of calcium carbonate. Similar crystals are formed by calcium
oxalate and calcium sulphate (after Funke).]
(3) Ammonium Urate Crystals.--This is the only urate deposited in
alkaline urine. It forms opaque yellow crystals, usually in the form
of spheres (Plate IV, and Fig. 63), which are often covered with fine
or coarse spicules, "thorn-apple crystals." Sometimes dumb-bells,
compact sheaves of fine needles, and irregular rhizome forms are seen
(Fig. 40). Upon addition of acetic acid they dissolve, and rhombic
plates of uric acid appear.
[Illustration: FIG. 40.--Crystals of ammonium urate (one-half of the
forms copied from Rieder's Atlas, the others from nature).]
[Illustration: PLATE IV. Sediment of alkaline fermentation (after
Hofmann and Ultzmann).]
{113} These crystals occur only when ammonia is present in excess.
They are generally found along with the phosphates in decomposing
urine and have no clinical significance.
B. ORGANIZED SEDIMENTS
The principal organized structures in urinary sediments are:
tube-casts; epithelial cells; pus-corpuscles; red blood-corpuscles;
spermatozoa; bacteria; and animal parasites. They are much more
important than the unorganized sediments just considered.
1. Tube-casts.--These interesting structures are albuminous molds of
the uriniferous tubules. Their presence in the urine probably always
indicates some pathologic change in the kidney, although this change
may be very slight or transitory. Large numbers may be present in
temporary irritations and congestions. _They do not in themselves,
therefore, imply organic disease of the kidney._ They probably occur
only in urine which contains, or has recently contained, albumin.
While it is not possible to draw a sharp dividing-line between the
different varieties, casts may be classified as: (1) Hyaline casts;
(2) waxy casts; (3) granular casts; (4) fatty casts; (5) casts
containing organized structures--(_a_) epithelial casts; (_b_)
blood-casts; (_c_) pus-casts; (_d_) bacterial casts. As will be seen,
practically all varieties are modifications of the hyaline.
The significance of the different varieties is more readily understood
if one considers their mode of formation. Albuminous material, the
source and nature of which are not definitely known, probably enters
the lumen of a uriniferous tubule in a fluid or plastic state. It
there hardens into a mold, which, when washed out by the {114} urine,
retains the shape of the tubule, and contains within its substance
whatever structures and débris were lying free within the tubule or
were loosely attached to its wall. If the tubule be small and have its
usual lining of epithelium, the cast will be narrow; if it be large or
entirely denuded of epithelium, the cast will be broad. A cast,
therefore, indicates the condition of the tubule in which it is
formed.
The search for casts must be carefully made. The urine must be fresh,
since hyaline casts soon dissolve when it becomes alkaline. It should
be thoroughly centrifugalized. When the sediment is abundant, casts,
being light structures, will be found near the top. In cystitis, where
casts may be entirely hidden by the pus, the bladder should be
irrigated to remove as much of the pus as possible and the next urine
examined. In order to prevent solution of the casts the urine, if
alkaline, must be rendered acid by previous administration of boric
acid or other drugs.
(1) Hyaline Casts.--Typically, these are colorless, homogeneous,
semitransparent, cylindric structures, with parallel sides and usually
rounded ends. Not infrequently they are more opaque or show a few
granules or an occasional cell, either adhering to them or contained
within their substance. Generally they are straight or curved; less
commonly, convoluted. Their length and breadth vary greatly: they are
sometimes so long as to extend across several fields of a medium-power
objective, but are usually much shorter; in breadth, they vary from
one to seven or eight times the diameter of a red blood-corpuscle.
(See Figs. 2, 41, 42, and 46.)
[Illustration: FIG. 41.--Hyaline casts showing fat-droplets and
leukocytes (obj. one-sixth) (Boston).]
[Illustration: FIG. 42.--Various kinds of casts: _a_, Hyaline and
finely granular cast; _b_, finely granular cast; _c_, coarsely
granular cast; _d_, brown granular cast; _e_, granular cast with
normal and abnormal blood adherent; _f_, granular cast with renal
cells adherent; _g_, granular cast with fat and a fatty renal cell
adherent (Ogden).]
Hyaline casts are the least significant of all the casts, {115} and
occur in many slight and transitory conditions. Small numbers are
common following ether anesthesia, in fevers, after excessive
exercise, and in congestions and irritations of the kidney. They are
always present, and are usually stained yellow when the urine contains
much bile. While they are found in all organic diseases of the kidney,
they {116} are most important in chronic interstitial nephritis. Here
they are seldom abundant, but their constant presence is the most
reliable urinary sign of the disease. Small areas of chronic
interstitial change are probably responsible for the few hyaline casts
so frequently found in the urine of elderly persons.
Very broad hyaline casts commonly indicate complete desquamation of
the tubular epithelium, such as occurs in the late stages of
nephritis.
(2) Waxy Casts.--Like hyaline casts, these are homogeneous when
typical, but frequently contain a few granules or an occasional cell.
They are much more opaque than the hyaline variety, and are usually
shorter and broader, with irregular, broken ends, and sometimes appear
to be segmented. They are grayish or colorless, and have a dull waxy
look, as if cut from paraffin (Figs. 43 and 61). They are sometimes
composed of material which gives the amyloid reactions. Waxy casts are
found in most advanced cases of nephritis, where they are an
unfavorable sign.
[Illustration: FIG. 43.--Waxy casts (upper part of figure). Fatty and
fat-bearing casts (lower part of figure) (from Greene's "Medical
Diagnosis").]
Casts which resemble waxy casts but have a distinctly {117} yellow
color, as if cut from beeswax (so-called "fibrinous casts"), are often
seen in acute nephritis. They have less serious significance than the
true waxy variety.
(3) Granular Casts.--These are merely hyaline casts in which numerous
granules are embedded (Figs. 42, 44, 46, and 61).
_Finely granular casts_ contain many fine granules, are usually
shorter, broader, and more opaque than the hyaline variety, and are
more conspicuous. Their color is grayish or pale yellow.
[Illustration: FIG. 44.--Granular and fatty casts and two compound
granular cells (Stengel).]
_Coarsely granular casts_ contain larger granules and are darker in
color than the finely granular, being often dark brown owing to
presence of altered blood-pigment. They are usually shorter and more
irregular in outline, and more frequently have irregularly broken
ends.
(4) Fatty Casts.--Small droplets of fat may at times be seen in any
variety of cast. Those in which the droplets are numerous are called
fatty casts (Figs. 43 and 44). The fat-globules are not difficult to
recognize. Staining with osmic acid or Sudan (p. 109) will remove any
doubt as to their nature.
{118} The granules and fat-droplets seen in casts are products of
epithelial degeneration. Granular and fatty casts, therefore, always
indicate partial or complete disintegration of the renal epithelium.
The finely granular variety is the least significant, and is found
when the epithelium is only moderately affected. Coarsely granular,
and especially fatty casts, indicate a serious parenchymatous
nephritis.
(5) Casts Containing Organized Structures.--Cells and other structures
are frequently seen adherent to a cast or embedded within it. (See
Figs. 41 and 42). When numerous, they give name to the cast.
(_a_) _Epithelial casts_ contain epithelial cells from the renal
tubules. They always imply desquamation of epithelium, which rarely
occurs except in parenchymatous inflammations (Figs. 60 and 61).
[Illustration: FIG. 45.--Red blood-corpuscles and blood-casts
(courtesy of Dr. A. Scott) (obj. one-sixth) (Boston).]
(_b_) _Blood-casts_ contain red blood-corpuscles, usually much
degenerated (Figs. 45 and 60). They always indicate hemorrhage into
the tubules, which is most {119} common in acute nephritis or an acute
exacerbation of a chronic nephritis.
(_c_) _Pus-casts_ (see Fig. 62), composed almost wholly of
pus-corpuscles, are uncommon, and point to a chronic suppurative
process in the kidney.
(_d_) True _bacterial casts_ are rare. They indicate a septic
condition in the kidney. Bacteria may permeate a cast after the urine
is voided.
[Illustration: FIG. 46.--Hyaline and granular casts, mucous threads,
and cylindroids. There are also a few epithelial cells from the
bladder (Wood).]
The structures most likely to be mistaken for casts are:
(1) Mucous Threads.--Mucus frequently appears in the form of long
strands which slightly resemble hyaline casts (Fig. 46). They are,
however, more ribbon-like, have less well-defined edges, and usually
show faint longitudinal striations. Their ends taper to a point or are
split or curled upon themselves, and are never evenly rounded, as is
commonly the case with hyaline casts.
(2) Cylindroids.--This name is sometimes given to the {120} mucous
threads just described, but is more properly applied to certain
peculiar structures more nearly allied to casts. They resemble hyaline
casts in structure, but differ in being broader at one end and
tapering to a slender tail, which is often twisted or curled upon
itself (Fig. 46). They frequently occur in the urine along with
hyaline casts, and have no definite pathologic significance.
(3) Masses of amorphous urates or phosphates or very small crystals
(Fig. 47), which accidentally take a cylindric form, or shreds of
mucus covered with granules, closely resemble granular casts.
Application of gentle heat or appropriate chemicals will serve to
differentiate them. When urine contains both mucus and granules, large
numbers of these "pseudo-casts," all lying in the same direction, can
be produced by slightly moving the cover-glass from side to side. It
is possible--as in urate infarcts of infants--for urates to be molded
into cylindric bodies within the renal tubules.
[Illustration: FIG. 47.--Calcium-oxalate crystals, showing a
pseudo-cast of small crystals (Jakob).]
(4) Hairs and fibers of wool, cotton, etc. These could be mistaken for
casts only by beginners. One can easily {121} become familiar with
their appearance by suspending them in water and examining with the
microscope (Fig. 57).
(5) Hyphæ of molds are not infrequently mistaken for hyaline casts.
Their higher degree of refraction, their jointed or branching
structure, and the accompanying spores will differentiate them (Fig.
58).
[Illustration: FIG. 48.--Renal epithelium from nephritic urine: _a_,
Polyhedral epithelium in nephritis of scarlet fever; _b_ and _c_,
different grades of fatty degeneration in renal epithelium in chronic
nephritis (X400) (after Bizzozero).]
2. Epithelial Cells.--A few cells from various parts of the urinary
tract occur in every urine. A marked increase indicates some
pathologic condition at the site of their origin. It is sometimes, but
by no means always, possible to locate their source from their form.
Any epithelial cell may be so granular from degenerative changes that
the nucleus is obscured. They are usually divided into three groups:
(1) Small, round, or polyhedral cells are about the size of
pus-corpuscles, or a little larger, with a single round nucleus. Such
cells may come from the deeper layers of any part of the urinary
tract. They are uncommon in normal urine. When they are dark in color,
very granular, and contain a comparatively large nucleus, they
probably come from the renal tubules, but their origin in the kidney
is not proved unless they are found embedded in casts. Renal cells are
abundant in parenchymatous nephritis, especially the acute form. They
are nearly always fatty--most markedly so in chronic parenchymatous
nephritis, where their {122} substance is sometimes wholly replaced by
fat-droplets ("compound granule cells") (see Figs. 44, 48, 60, and
61).
(2) Irregular cells are considerably larger than the preceding. They
are round, pear-shaped, or spindle-shaped, or may have tail-like
processes, and are hence named large round, pyriform, spindle, or
caudate cells respectively. Each contains a round or oval distinct
nucleus. Their usual source is the deeper layers of the urinary tract,
especially of the bladder. Caudate forms come most commonly from the
pelvis of the kidney (see Figs. 49, _b_, 50, 62, and 63).
[Illustration: FIG. 49.--Epithelial cells from urethra and bladder:
_a_, Squamous cells from superficial layers; _b_, irregular cells from
deeper layers (Jakob).]
(3) Squamous or pavement cells are large flat cells, each with a
small, distinct, round or oval nucleus (Fig. 49, _a_). They are
derived from the superficial layers of the ureters, bladder, urethra,
or vagina. Those from the bladder are generally rounded, while those
from the vagina are larger, thinner, and more angular. Great numbers
of these vaginal cells, together with pus-corpuscles, may be present
when leukorrhea exists.
{123} [Illustration: FIG. 50.--Caudate epithelial cells from pelvis of
kidney (Jakob).]
3. Pus-corpuscles.--A very few leukocytes are present in normal urine.
They are more abundant when mucus is present. An excess of leukocytes,
mainly of the polymorphonuclear variety, with albumin, constitutes
_pyuria_--pus in the urine.
When at all abundant, pus forms a white sediment resembling amorphous
phosphates macroscopically. Under the microscope the corpuscles appear
as very granular cells, about twice the diameter of a red
blood-corpuscle (Figs. 51 and 63). In freshly voided urine many
exhibit ameboid motion, assuming irregular outlines. Each contains one
irregular nucleus or several small, rounded nuclei. The nuclei are
obscured or entirely hidden by the granules, but may be brought
clearly into view by running a little acetic acid under the
cover-glass. This enables one to easily distinguish pus-corpuscles
from small round epithelial cells, which resemble them in size, but
have a single, rather large, round nucleus.
Pyuria indicates suppuration in some part of the urinary {124}
tract--urethritis, cystitis, pyelitis, etc.--or may be due to
contamination from the vagina, in which case many vaginal epithelial
cells will also be present. In general, the source of the pus can be
determined only by the accompanying structures (epithelia, casts) or
by the clinical signs.
A fairly accurate idea of the quantity of pus from day to day may be
had by shaking the urine thoroughly and counting the number of
corpuscles per cubic millimeter upon the Thoma-Zeiss blood-counting
slide.
[Illustration: FIG. 51.--Pus-corpuscles: _a_, As ordinarily seen; _b_,
ameboid corpuscles; _c_, showing the action of acetic acid (Ogden).]
4. Red Blood-corpuscles.--Urine which contains blood is always
albuminous. Very small amounts do not alter its macroscopic
appearance. Larger amounts alter it considerably. Blood from the
kidneys is generally intimately mixed with the urine and gives it a
hazy reddish or brown color. When from the lower urinary tract, it is
not so intimately mixed, and settles more quickly to the bottom, the
color is brighter, and small clots are often present.
Red blood-corpuscles are not usually difficult to recognize with the
microscope. When very fresh, they have a normal appearance, being
yellowish discs of uniform size (normal blood). When they have been in
the urine any {125} considerable time, their hemoglobin may be
dissolved out, and they then appear as faint colorless circles or
"shadow cells" (abnormal blood), and are more difficult to see (Fig.
52; see also Figs. 45 and 60). They are apt to be swollen in dilute
and crenated in concentrated urines. The microscopic findings may be
corroborated by chemic tests for hemoglobin, although the microscope
may show a few red corpuscles when the chemic tests are negative.
[Illustration: FIG. 52.--Blood-corpuscles: _a_, Normal; _b_, abnormal
(Ogden).]
When not due to contamination from menstrual discharge, blood in the
urine, or _hematuria_, is always pathologic. Blood comes from the
kidney tubules in severe hyperemia, in some forms of nephritis, and in
renal tuberculosis and malignant disease. The finding of blood-casts
is the only certain means of diagnosing the kidney as its source.
Blood comes from the pelvis of the kidney in renal calculus (Fig. 62),
and is then usually intermittent, small in amount, and accompanied by
a little pus and perhaps crystals of the substance forming the stone.
Considerable hemorrhages from the bladder may occur in vesical
calculus, tuberculosis, and newgrowths. Small amounts of blood
generally accompany acute cystitis.
5. Spermatozoa are generally present in the urine of men after
nocturnal emissions, after epileptic convulsions, and in
spermatorrhea. They may be found in the urine of both sexes following
coitus. They are easily recognized {126} from their characteristic
structure (Fig. 53). The one-sixth objective should be used, with
subdued light and careful focusing.
[Illustration: FIG. 53.--Spermatozoa in urine (Ogden).]
[Illustration: FIG. 54.--Micrococcus ureæ (after von Jaksch).]
6. Bacteria.--Normal urine is free from bacteria in the bladder, but
becomes contaminated in passing through the urethra. Various
non-pathogenic bacteria, notably _Micrococcus ureæ_ (Fig. 54), are
always present in decomposing urine. In suppurations of the urinary
tract pus-producing organisms may be found. In many infectious
diseases the specific germs may be eliminated in {127} the urine
without producing any local lesion. Typhoid bacilli have been known to
persist for months and even years after the attack.
Bacteria produce a cloudiness which will not clear upon filtration.
They are easily seen with the one-sixth objective in the routine
microscopic examination. Ordinarily, no attempt is made to identify
any but the tubercle bacillus and the gonococcus.
Tubercle bacilli are nearly always present in the urine when
tuberculosis exists in any part of the urinary tract, but are often
difficult to find, especially when the urine contains little or no
pus.
* * * * *
Detection of Tubercle Bacilli in Urine.--The urine should be obtained
by catheter after careful cleansing of the parts.
(1) Centrifugalize thoroughly, after dissolving any sediment of urates
or phosphates by gentle heat or acetic acid. Pour off the supernatant
fluid, add water, and centrifugalize again. Addition of one or two
volumes of alcohol will favor centrifugalization by lowering the
specific gravity.
(2) Make thin smears of the sediment, adding a little egg-albumen if
necessary to make the smear adhere to the glass; dry, and fix in the
usual way.
(3) Stain with carbol-fuchsin, steaming, for at least three minutes.
(4) Wash in water, and then in 20 per cent. nitric acid until only a
faint pink color remains.
(5) Wash in water.
(6) Soak in alcohol fifteen minutes or longer. This decolorizes the
smegma bacillus (p. 35), which is often present in the urine, and
might easily be mistaken for the tubercle bacillus. It is unlikely,
however, to be present in catheterized specimens. It is always safest
to soak the smear in alcohol for several {128} hours or over night,
since some strains of the smegma bacillus are very resistant.
(7) Wash in water.
(8) Apply Löffler's methylene-blue solution one-half minute.
(9) Rinse in water, dry between filter-papers, and examine with the
one-twelfth objective.
When the bacilli are scarce, the following method may be tried. It is
applicable also to other fluids. If the fluid is not albuminous, add a
little egg-albumen. Coagulate the albumen by gentle heat and
centrifugalize. The bacilli will be carried down with the albumen.
Separate the albumen, mix with artificial gastric juice (for
preparation of which see test for pepsin, p. 222), and set in an
incubator or warm place until digested. Finally, centrifugalize and
stain as described above. The bacilli do not stain so well as in the
ordinary methods.
A careful search of many smears may be necessary to find the bacilli.
They usually lie in clusters (see Plate V). Failure to find them in
suspicious cases should be followed by inoculation of guinea-pigs;
this is the court of last appeal, and must also be sometimes resorted
to in order to exclude the smegma bacillus.
* * * * *
In gonorrhoea gonococci are sometimes found in the sediment, but more
commonly in the "gonorrheal threads," or "floaters." In themselves,
these threads are by no means diagnostic of gonorrhea. Detection of
the gonococcus is described later (p. 264).
[Illustration: PLATE V. Tubercle bacilli in urinary sediment; X800
(Ogden).]
7. Animal parasites are rare in the urine. Hooklets and scolices of
_Tænia echinococcus_ (Fig. 55) and embryos of _Filaria sanguinis
hominis_ have been met. In Africa the ova, and even adults, of
_Distoma hæmatobium_ are common, accompanying "Egyptian hematuria."
[Illustration: FIG. 55.--1, Scolex of tænia echinococcus, showing
crown of hooklets; 2, scolex and detached hooklets (obj. one-sixth)
(Boston).]
[Illustration: FIG. 56.--Embryo of "vinegar eel" in urine, from
contamination; length, 340 µ; width, 15 µ. An epithelial cell from
bladder and three leukocytes are also shown (studied with Dr. J. A.
Wilder).]
Other parasites, most of which are described in Chapter VI, may be
present from contaminations. A worm {129} which is especially
interesting is _Anguillula aceti_, the "vinegar eel." This is
generally present in the sediment of table vinegar, and may reach the
urine through use of vinegar in vaginal douches, or through
contamination of the bottle in which the urine is contained. It has
been mistaken for _Strongyloides intestinalis_ and for _Filaria
sanguinis hominis_. It closely resembles the former in {130} both
adult and embryo stages. The young embryos have about the same length
as filaria embryos, but are nearly twice as broad and the intestinal
canal is easily seen (compare Figs. 56 and 107).
C. EXTRANEOUS STRUCTURES
The laboratory worker must familiarize himself with the microscopic
appearance of the more common of the numerous structures which may be
present from accidental contamination (Fig. 57).
[Illustration: FIG. 57.--Extraneous matters found in urine: _a_,
Flax-fibers; _b_, cotton-fibers; _c_, feathers; _d_, hairs; _e_,
potato-starch; _f_, rice-starch granules; _g_, wheat-starch; _h_,
air-bubbles; _i_, muscular tissue; _k_, vegetable tissue; _l_,
oil-globules.]
_Yeast-cells_ are smooth, colorless, highly refractive, spheric or
ovoid cells. They sometimes reach the size of {131} a leukocyte, but
are generally smaller (see Fig. 88, _l_). They might be mistaken by
the inexperienced for red blood-corpuscles, fat-droplets, or the
spheric crystals of calcium oxalate, but are distinguished by the
facts that they are not of uniform size; that they tend to adhere in
short chains; that small buds may often be seen adhering to the larger
cells; and that they do not give the hemoglobin test, are not stained
by osmic acid or Sudan but are colored brown by Lugol's solution, and
are insoluble in acids and alkalis. Yeast-cells multiply rapidly in
diabetic urine, and may reach the bladder and multiply there.
_Mold fungi_ (Fig. 58) are characterized by refractive, jointed, or
branched rods (hyphæ), often arranged in a network, and by highly
refractive, spheric or ovoid spores. They are common in urine which
has stood exposed to the air.
[Illustration: FIG. 58.--Aspergillus from urine (Boston).]
_Fibers_ of wool, cotton, linen, or silk, derived from towels, the
clothing of the patient, or the dust in the air are present in almost
every urine. _Fat-droplets_ are most frequently derived from unclean
bottles or oiled catheters. _Starch-granules_ may reach the urine from
towels, the {132} clothing, or dusting-powders. They are recognized by
their concentric striations and their blue color with iodin solution.
_Lycopodium granules_ (Fig. 59) may also reach the urine from
dusting-powders. They might be mistaken for the ova of parasites.
_Bubbles of air_ are often confusing to beginners, but are easily
recognized after once being seen. _Scratches_ and _flaws_ in the glass
of slide or cover are likewise a common source of confusion to
beginners.
[Illustration: FIG. 59.--Granules of lycopodium (Saxe).]
IV. THE URINE IN DISEASE
In this section the characteristics of the urine in those diseases
which produce distinctive urinary changes will be briefly reviewed.
1. Renal Hyperemia.--_Active hyperemia_ is usually an early stage of
acute nephritis, but may occur independently as a result of temporary
irritation. The urine is generally decreased in quantity, highly
colored, and strongly acid. Albumin is always present--usually in
traces only, but sometimes in considerable amount for a day or two.
The sediment contains a few hyaline and finely granular casts and an
occasional red blood-cell. In very severe hyperemia the urine
approaches that of acute nephritis.
{133} [Illustration: FIG. 60.--Sediment from acute hemorrhagic
nephritis: Red blood-corpuscles; leukocytes; renal cells not fattily
degenerated; epithelial and blood-casts (Jakob).]
[Illustration: FIG. 61.--Sediment from chronic parenchymatous
nephritis: hyaline (with cells attached), waxy, brown granular, fatty,
and epithelial casts; fattily degenerated renal cells; and a few white
and red blood-corpuscles (Jakob).]
_Passive hyperemia_ occurs most commonly in diseases of the heart and
liver and in pregnancy. The quantity of urine is somewhat low and the
color high, except in pregnancy. Albumin is present in small amount
only. The sediment contains a very few hyaline or finely granular
{134} casts. In pregnancy the amount of albumin should be carefully
watched, as any considerable quantity, and especially a rapid
increase, strongly suggests approaching eclampsia.
2. Nephritis.--The various degenerative and inflammatory conditions
grouped under the name of nephritis have certain features in common.
The urine in all cases contains albumin and tube-casts, and in all
well-marked cases shows a decrease of normal solids, especially of
urea and the chlorids. The characteristics of the different forms are
well shown in the table on opposite page, modified from Hill.
{135} THE URINE IN NEPHRITIS
PHYSICAL. CHEMIC. MICROSCOPIC.
---------------------+---------------------+------------------------
Acute nephritis.
| |
Quantity diminished, | Urea and chlorids | Sediment abundant, red
often very greatly. | low. Much albumin: | or brown. Many casts,
Color dark; may be | up to 1.5 per cent. | chiefly granular, blood
red or smoky. | Reaction acid. | and epithelial
Specific gravity, | | varieties. Red
1.020 to 1.030. | | blood-cells abundant.
| | Numerous renal
| | epithelial cells and
| | leukocytes.
---------------------+---------------------+------------------------
Chronic parenchymatous nephritis.
| |
Quantity usually | Urea and chlorids | Sediment rather
diminished. Color | low. Largest | abundant. Many casts of
variable, often pale | amounts of albumin: | all varieties: fatty
and hazy. Specific | up to 3 per cent. | casts and casts of
gravity, 1.010 to | Reaction acid. | degenerated epithelium
1.020. | | most characteristic.
| | Blood present in
| | traces: abundant only
| | in acute exacerbations.
| | Numerous fattily
| | degenerated renal
| | epithelial cells, often
| | free globules of fat,
| | and a few leukocytes.
---------------------+---------------------+------------------------
Chronic interstitial nephritis.
| |
Quantity markedly | Urea and chlorids | Sediment very slight.
increased, | low in well-marked | Few narrow hyaline and
especially at night. | cases. Albumin | finely granular casts.
Color pale, clear. | present in traces | No blood except in
Specific gravity, | (often overlooked), | acute exacerbations.
1.005 to 1.015. | increasing in late | Very few renal cells.
| stages. Reaction | Uric acid and
| acid. | calcium-oxalate
| | crystals common.
---------------------+---------------------+------------------------
Amyloid degeneration of kidney.
| |
Quantity moderately | Slight decrease of | Sediment slight.
increased. Color | urea and chlorids. | Moderate number of
pale, clear. | Variable amounts of | hyaline, finely
Specific gravity, | albumin and | granular, and sometimes
1.012 to 1.018. | globulin. | waxy casts.
---------------------+---------------------+------------------------
3. Renal Tuberculosis.--The urine is pale, usually cloudy. The
quantity may not be affected, but is apt to be increased. In early
cases the reaction is faintly acid and there are traces of albumin and
a few renal cells. In advanced cases the urine is alkaline, has an
offensive odor, and is irritating to the bladder. Albumin in varying
amounts is always present. Pus is nearly always present, though
frequently not abundant. It is generally intimately mixed with the
urine, and does not settle so quickly as the pus of cystitis. Casts,
though present, are rarely abundant, and are obscured by the pus.
Small amounts of blood are common. Tubercle bacilli are nearly always
present, although animal inoculation may be necessary to detect them.
4. Renal Calculus.--The urine is usually somewhat concentrated, with
high color and strongly acid reaction. Small amounts of albumin and a
few casts may be present as a result of kidney irritation. Blood is
frequently present, especially in the daytime and after severe
exercise. Crystals of the substance composing the calculus--uric {136}
acid, calcium oxalate, cystin--may often be found. The presence of a
calculus generally produces pyelitis, and variable amounts of pus then
appear, the urine remaining acid in reaction.
5. Pyelitis.--In pyelitis the urine is slightly acid, and contains a
small or moderate amount of pus, together with many spindle and
caudate epithelial cells. Pus-casts may appear if the process extends
up into the kidney tubules (see Fig. 62). Albumin is always present,
and its amount, in proportion to the amount of pus, is decidedly
greater than is found in cystitis.
[Illustration: FIG. 62.--Sediment from calculous pyelitis: numerous
pus-corpuscles, red blood-corpuscles, and caudate and irregular
epithelial cells; a combination of hyaline and pus-cast; and a few
uric-acid crystals (Jakob).]
6. Cystitis.---In _acute_ and _subacute_ cases the urine is acid and
contains a variable amount of pus, with many epithelial cells from the
bladder--chiefly large round, pyriform, and rounded squamous cells.
Red blood-corpuscles are often numerous.
In _chronic_ cases the urine is generally alkaline. It is {137} pale
and cloudy from the presence of pus, which is abundant and settles
readily into a viscid sediment. The sediment usually contains abundant
amorphous phosphates and crystals of triple phosphate and ammonium
urate. Vesical epithelium is common. Numerous bacteria are always
present (see Fig. 63).
[Illustration: FIG. 63.--Sediment from cystitis (chronic): numerous
pus-corpuscles, epithelial cells from the bladder, and bacteria; a few
red blood-corpuscles and triple phosphate and ammonium urate crystals
(Jakob).]
7. Vesical Calculus, Tumors, and Tuberculosis.--These conditions
produce a chronic cystitis, with its characteristic urine. Blood,
however, is more frequently present and more abundant than in ordinary
cystitis. With neoplasms, especially, considerable hemorrhages are apt
to occur. Particles of the tumor are sometimes passed with the urine.
No diagnosis can be made from the presence of isolated tumor cells. In
tuberculosis tubercle bacilli can generally be detected.
8. Diabetes Insipidus.--Characteristic of this disease is the
continued excretion of very large quantities of pale, watery urine,
containing neither albumin nor sugar. The {138} specific gravity
varies between 1.001 and 1.005. The daily output of solids, especially
urea, is increased.
9. Diabetes Mellitus.--The quantity of urine is very large. The color
is generally pale, while the specific gravity is nearly always
high--1.030 to 1.050, very rarely below 1.020. The presence of glucose
is the essential feature of the disease. The amount of glucose is
often very great, sometimes exceeding 8 per cent., while the total
elimination may exceed 500 gm. in twenty-four hours. It may be absent
temporarily. Acetone is generally present in advanced cases. Diacetic
acid may be present, and usually warrants an unfavorable prognosis.
{139}