A Permanent Preparation of Urease, and Its Use for Rapid and Accurate Determination of Urea.

Slyke, Donald D. Van; Cullen, Glenn E.

doi:10.1001/jama.1914.25610450002016c

Cited by 46 publications

(21 citation statements)

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“…Nevertheless, if a large number of the cells are injured so that their individ.ual ability to function is impaired, the effect upon the ratio should be the same, and, if this impairment is very marked, the ratio should fall even when no urea is injected. The urea of both the blood and the urine was determined in our experiments by the Van SlykeCullen modification of Marshal's urease method (14,15).…”

Section: Methodsmentioning

confidence: 99%

I. Renal Function Influenced by Intestinal Obstruction

McQuarrie

Whipple

1919

Journal of Experimental Medicine

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Associated with the intoxication of intestinal obstruction there exists a definite impairment of the excretory function of the kidneys. The degree of functional depression corresponds roughly with the intensity of the clinical intoxication. The decrease in the urea ratio and in the capacity of the kidneys to excrete sodium chloride is more marked than is the percentage decrease of phenolsulfonephthalein elimination. The great increase in the non-protein nitrogen of the blood usually observed in acute intestinal obstruction, which has hitherto been explained as being due entirely to an increased rate of protein catabolism, is due in part to retention of the products released from the injured cell protein. It is probable that the impaired renal function is due to direct action of the toxic substances upon the renal epithelium. The actual demonstration of this renal injury is perhaps the strongest evidence so far obtained to prove the presence of an actual toxic substance in the blood during intestinal obstruction. This obscure disability of the kidneys during the height of the intoxication of acute ileus should always be considered in the clinical management of this condition. It may also serve as a guide to indicate the degree of intoxication.

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Section: Methodsmentioning

confidence: 99%

I. Renal Function Influenced by Intestinal Obstruction

McQuarrie

Whipple

1919

Journal of Experimental Medicine

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“…of saturated boric acid, and the mixture of bromcresol green and methyl red suggested by Ma and Zuazaga (6) was used as an indicator. Urea and ammonia nitrogen were determined by the method of Van Slyke and Cullen (7).…”

Section: Methodsmentioning

confidence: 99%

Metabolic Alterations Following Thermal Burns. I. Nitrogen Balance in Experimental Burns1

Meyer

Joseph²,

Hirshfeld³

et al. 1945

J. Clin. Invest.

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Several investigators (1 to 4) have shown that a negative nitrogen balance exists following a burn. It was suggested that the prevention or alleviation of this loss of nitrogen might promote healing and improve the prognosis of the severely burned patient. Since, however, it is difficult to evaluate the significance of nitrogen balance studies in patients because of the marked variation in their age, their nutritional status previous to burning, and the depth and severity of their injury, it seemed advisable to carry out nitrogen balance studies in animals under controlled conditions. METHODS AND MATERIALSAdult female mongrel dogs were selected for the study. They were fed 10 or 11 grams per kilogram of body weight of the following mixture in parts per hundred: casein 37.4, dextrose 26.4, Crisco 22.2, salt mixture (U.S.P. Salt Mixture No. 1) 3.5, dried yeast 6.8, bone ash 2.7, and cod liver oil 1.0. The amount of food consumed daily by each animal was weighed, and samples of each batch of food were analyzed for nitrogen content. After the dogs had consumed this diet for a preliminary period of ten days to two weeks, they were placed in metabolism cages. Urine was collected under toluene and a daily aliquot removed and pooled for a 5-day period. At the beginning of the study, and at the end of each 5-day period, the bladder was catheterized to insure full collection. Feces, marked with carmine, were preserved with an acid-alcohol solution, dried on the steam bath and ground to a powder.The nitrogen balance and body weight were followed for three 5-day periods to insure nitrogen equilibrium or a slightly positive balance and the maintenance of relatively constant weight. The animals were then burned under anesthesia (intravenous nembutal). Hot irons with a uniform surface area (12.57 cm.) were employed so that an estimate of the surface area burned could be calculated.

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“…The introduction of enzymes as reagents and the use of measurement in the ultraviolet wavelength range led to increased sensitivity, decreased sample volume, and simpler analytical procedures. Urease, which converts urea to ammonium ion, was used as early as 1914 (24 ). The modern clinical chemistry laboratory now uses a wide variety of photometric techniques, including fluorescence, fluorescence polarization, nephelometry, chemiluminescence, phosphorescence, and electrochemiluminescence.…”

Section: International Year Of Chemistry 2011mentioning

confidence: 99%

International Year of Chemistry 2011: A Guide to the History of Clinical Chemistry

Kricka

Savory

2011

Clinical Chemistry

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BACKGROUND This review was written as part of the celebration of the International Year of Chemistry 2011. CONTENT In this review we provide a chronicle of the history of clinical chemistry, with a focus on North America. We outline major methodological advances and trace the development of professional societies and journals dedicated to clinical chemistry. This review also serves as a guide to reference materials for those interested in the history of clinical chemistry. The various resources available, in sound recordings, videos, moving images, image and document archives, museums, and websites dedicated to diagnostic company timelines, are surveyed. SUMMARY These resources provide a map of how the medical subspecialty of clinical chemistry arrived at its present state. This information will undoubtedly help visionaries to determine in which direction clinical chemistry will move in the future.

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A Permanent Preparation of Urease, and Its Use for Rapid and Accurate Determination of Urea.

Cited by 46 publications

References 0 publications

I. Renal Function Influenced by Intestinal Obstruction

I. Renal Function Influenced by Intestinal Obstruction

Metabolic Alterations Following Thermal Burns. I. Nitrogen Balance in Experimental Burns1

International Year of Chemistry 2011: A Guide to the History of Clinical Chemistry

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