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CHEMICAL SPOT TEST IN DIAGNOSIS OF URÆMIA
1061 First attack.-The patient was aged 29 when the first attack of pneumococcal meningitis occurred on April 16th, 1932. The onset was abrupt, characterised by severe frontal headache. Within five hours he was unconscious, and when admitted to Prof. A. Patrick’s ward in Dundee Royal Infirmary seven hours after the onset he was unconscious and violent. With intervals during which he was rational his condition remained the same for 18 days. Then he gradually improved, and when he was discharged from hospital on June 28th he appeared to have recovered. Papillcedema, which had been severe, had subsided, and no visual defect remained. He was examined at monthly intervals thereafter and showed no sign of the disease. On Dec. 7th, 1932, lumbar puncture revealed a normal cerebro-spinal fluid. After that date he did not report again. The diagnosis had been confirmed by culture of pneumococci from the cerebro-spinal fluid. Second attark.-The patient had been in good health since December, 1932, and had resumed his occupation as a shepherd. Occasionally he had complained of slight frontal headache. On March 5th, 1934, he had been working during the morning. At midday he complained of severe headache of sudden onset. About 7 P.M. he became unconscious, and on admission to Dundee Royal Infirmary on the following morning he was unconscious and violent. His appearance resembled that observed at the commencement of the first attack of meningitis two years before. The cerebro-spinal fluid was turbid, under normal tension, and contained 11,300 cells per c.mm., all polymorphonuclears. Pneumococci were present in the film, and were grown in pure culture. The organism was found by Prof. W. J. Tulloch to belong to type IV. During the first attack of meningitis, lumbar puncture, performed daily, had appeared to afford relief, and it was proposed to carry out the same treatment during the present illness. His condition failed to improve, however, and he died three days after the onset of the disease on March 8th. Post-mortem /:K.eg’s.—At autopsy, by Prof. D. F. Cappell, the brain was found to be soft and hyperasmic. Green purulent exudate had collected at the base of the brain and round the brain stem. A thin film of exudate covered the cortex of the cerebral hemispheres. The middle ear on both sides and the cranial sinuses were healthy. There was no evidence of lung consolidation, and there was no respiratory catarrh. No primary focus could be demonstrated which might have been responsible for infection of the meninges.
clinical picture during the corresponding in both attacks was similar. The abrupt period onset with headache, followed within a few hours by mental excitement, restlessness, and unconsciousness, occurred in both attacks. In the first attack the cerebro-spinal fluid was less turbid, and contained fewer pus cells (1650 per c.mm., as against 11,300 in the second attack). In both no primary focus of infection could be found clinically, and in the second autopsy failed to reveal it. The
I am indebted to Prof. Patrick for to publish the case.
permission
precipitated the proteins with trichloracetic acid, and after filtering developed the colour in a clear filtrate. Blood specimens containing a normal amount of urea (20-40 mg. per 100c.cm.) developed no perceptible colour, whereas those much above normal in
respect to urea content showed the characteristic coloration, which was the more intense the higher the amount of urea present. The reaction thus outlined, though attention was called to it by Hunt,2 does not seem to have been
employed to any large extent in this country, probably because the time and labour involved is only slightly less than some of the direct Nesslerisation or hypobromite methods, which go further in achieving a roughly quantitative estimation of blood-urea. For several-years past in this laboratory a simpler modification of the reaction has been in
use
and has
proved invaluable in routine work. This consists merely in applying a drop of Ehrlich’s reagent directly to a drop of plasma placed on a white filter paper. Where there is much nitrogen retention the spot on the filter paper shows immediately the characteristic greenish colour, no appreciable colour being present with normal or slightly raised blood-urea. More recently attention has been given to the best means of applying the spot reaction directly to whole blood, so as to provide a test which might well be done at the bedside. The technique described below, employing a composite reagent, has been found to work very satisfactorily and takes only one minute to perform on a given sample of blood. Erhlich’s reagent (10 g. p-dimethyl100 c.cm. concentrated HC1, made up to a total volume of 300 c.cm. with distilled water), add 20 per cent. trichloracetic acid drop by drop with shaking until the cloudiness which forms with each drop
Reagent.-To the aminobenzaldehyde,
just faintly persists. Tec/MMMe.—To a
*
small volume of blood placed in a narrow test-tube-a few drops of oxalated finger blood will suffice-add an approximately equal volume of the reagent. Shake the mixture vigorously for a few seconds, and then pour a drop of the somewhat thick coagulum on to a white filter paper. The filtrate spreads as a gradually extending circle, leaving a brown centre of precipitated protein. Attention is then directed to that part of the spot external to the dark centre. With true uremia the spot shows a distinct green colour. Blood specimens with normal or only slightly raised urea content show no coloration against the white background. The subsequent development of the outer area of the spot has a certain amount of interest in a confirmatory sense. When dry the degree of yellow of a ursemia spot very slowly intensifies, and after the lapse of several hours the spot becomes a bright canary yellow. Bloods displaying little or no,urea retention eventually leave only a dull pale green spot. no substitute for the bloodit ought in general to be indeed estimation ; followed up by an exact determination. It is, however, eminently suitable for conditions of emergency where it is desired to ascertain at once whether or not there is gross retention of nitrogen.
The test is of
course
urea
CHEMICAL
SPOT TEST IN DIAGNOSIS OF URÆMIA
BY JOCELYN
PATTERSON, M.Sc., Ph.D.
BIOCHEMIST, CHARING CROSS
HOSPITAL
(From the Institute of Pathology, Charing Cross Hospital) A
by
TEST diagnostic of high blood-urea was devised Weltmann and Barrenscheen,’- who utilised the
reaction between
urea and p-dimethylaminobenzaldehyde (Ehrlich’s reagent), which gives rise to a yellowish-green coloration of somewhat low intensity. Preparatory to applying the reagent to blood they
1Weltmann, O., and Barrenscheen, H. K.: Klin. Woch., 1922,
i., 1100.
2 Hunt,
SHROPSHIRE
T. C.: THE LANCET,
ORTHOPAEDIC
1929, ii., 751.
HOSPITAL.-The long
task of reconstructing this institution was reported at the recent annual meeting to be making fair progress. The trustees of the James Laing Trust have given 10,000 for memorials, to form part of the building, of the late James and Nancy Laing. Last year 1328 patients were treated-787 adults and 541 children. The adults stayed on an average 118, and the children 105 days. There was a credit balance on the year of JE301.
clinical picture during the corresponding in both attacks was similar. The abrupt period onset with headache, followed within a few hours by mental excitement, restlessness, and unconsciousness, occurred in both attacks. In the first attack the cerebro-spinal fluid was less turbid, and contained fewer pus cells (1650 per c.mm., as against 11,300 in the second attack). In both no primary focus of infection could be found clinically, and in the second autopsy failed to reveal it. The
I am indebted to Prof. Patrick for to publish the case.
permission
precipitated the proteins with trichloracetic acid, and after filtering developed the colour in a clear filtrate. Blood specimens containing a normal amount of urea (20-40 mg. per 100c.cm.) developed no perceptible colour, whereas those much above normal in
respect to urea content showed the characteristic coloration, which was the more intense the higher the amount of urea present. The reaction thus outlined, though attention was called to it by Hunt,2 does not seem to have been
employed to any large extent in this country, probably because the time and labour involved is only slightly less than some of the direct Nesslerisation or hypobromite methods, which go further in achieving a roughly quantitative estimation of blood-urea. For several-years past in this laboratory a simpler modification of the reaction has been in
use
and has
proved invaluable in routine work. This consists merely in applying a drop of Ehrlich’s reagent directly to a drop of plasma placed on a white filter paper. Where there is much nitrogen retention the spot on the filter paper shows immediately the characteristic greenish colour, no appreciable colour being present with normal or slightly raised blood-urea. More recently attention has been given to the best means of applying the spot reaction directly to whole blood, so as to provide a test which might well be done at the bedside. The technique described below, employing a composite reagent, has been found to work very satisfactorily and takes only one minute to perform on a given sample of blood. Erhlich’s reagent (10 g. p-dimethyl100 c.cm. concentrated HC1, made up to a total volume of 300 c.cm. with distilled water), add 20 per cent. trichloracetic acid drop by drop with shaking until the cloudiness which forms with each drop
Reagent.-To the aminobenzaldehyde,
just faintly persists. Tec/MMMe.—To a
*
small volume of blood placed in a narrow test-tube-a few drops of oxalated finger blood will suffice-add an approximately equal volume of the reagent. Shake the mixture vigorously for a few seconds, and then pour a drop of the somewhat thick coagulum on to a white filter paper. The filtrate spreads as a gradually extending circle, leaving a brown centre of precipitated protein. Attention is then directed to that part of the spot external to the dark centre. With true uremia the spot shows a distinct green colour. Blood specimens with normal or only slightly raised urea content show no coloration against the white background. The subsequent development of the outer area of the spot has a certain amount of interest in a confirmatory sense. When dry the degree of yellow of a ursemia spot very slowly intensifies, and after the lapse of several hours the spot becomes a bright canary yellow. Bloods displaying little or no,urea retention eventually leave only a dull pale green spot. no substitute for the bloodit ought in general to be indeed estimation ; followed up by an exact determination. It is, however, eminently suitable for conditions of emergency where it is desired to ascertain at once whether or not there is gross retention of nitrogen.
The test is of
course
urea
CHEMICAL
SPOT TEST IN DIAGNOSIS OF URÆMIA
BY JOCELYN
PATTERSON, M.Sc., Ph.D.
BIOCHEMIST, CHARING CROSS
HOSPITAL
(From the Institute of Pathology, Charing Cross Hospital) A
by
TEST diagnostic of high blood-urea was devised Weltmann and Barrenscheen,’- who utilised the
reaction between
urea and p-dimethylaminobenzaldehyde (Ehrlich’s reagent), which gives rise to a yellowish-green coloration of somewhat low intensity. Preparatory to applying the reagent to blood they
1Weltmann, O., and Barrenscheen, H. K.: Klin. Woch., 1922,
i., 1100.
2 Hunt,
SHROPSHIRE
T. C.: THE LANCET,
ORTHOPAEDIC
1929, ii., 751.
HOSPITAL.-The long
task of reconstructing this institution was reported at the recent annual meeting to be making fair progress. The trustees of the James Laing Trust have given 10,000 for memorials, to form part of the building, of the late James and Nancy Laing. Last year 1328 patients were treated-787 adults and 541 children. The adults stayed on an average 118, and the children 105 days. There was a credit balance on the year of JE301.