bluuebunny/crossref_metadata_2025 huggingface dataset:
The Determination of Thiamine in Small Amounts of Whole Blood and Serum by a Simplified Thiochrome Method
Authors: Myint Than , Houser Harold B
Published: January 2020

This simplified thiochrome method for the determination of thiamine eliminates deproteinization, sample dilution (other than reagent), and purification by adsorption column; pH need not be adjusted as it is automatically controlled. The method depends upon the hydrolysis of whole blood and serum with N HCI, N/10 HCI, and diastase enzyme. Reproducibility was good; the mean differences (± S.D.) between duplicate blood and serum samples were 2.36 ± 2.87 and 1.5 ± 1.70 mµg./ml., respectively. Recovery of added thiamine ranged from 94 to 104% with a mean of 99.5 ± 3.41%. Storage of hydrolysates for 30 days did not change the results, and low serum concentrations could be measured in serum. Whole blood and serum values of thiamine in 44 healthy adults ranged from 11.3 to 47.8 mµg./ml. (mean, 29.3) and from trace amounts to 20.5 mµg./ml. (mean, 10.2), respectively.
Automated and Manual Direct Methods for the Determination of Blood Urea
Authors: Marsh Walton H , Fingerhut Benjamin , Miller Henry
Published: January 2020

Automated and manual direct methods for the determination of urea in blood or serum are described. These methods determine urea by the colored product formed when urea, in relatively weak acid solution, reacts with diacetyl monoxime in the presence of thiosemicarbazide and ferric ion. Results are compared with those obtained by urease conversion of urea to ammonia and measurement of the ammonia by nesslerization.
An Automated Fluorometric Method for Determination of Lactic Dehydrogenase in Serum
Authors: Brooks Lewis , Olken Harry G
Published: January 2020

A simple automated method for the determination of lactic dehydrogenase (LDH) activity in serum by the forward lactate → pyruvate reaction is presented. Enzyme activity is determined by measuring the fluorescence of DPNH formed after a fixed incubation time. Detailed studies of various parameters of the reaction, reproducibility, and recovery data, and a comparison with two manual methods for LDH are presented.
A New Method for the Continuous Monitoring of Blood Glucose by Measurement of Dissolved Oxygen
Authors: Kadish Arnold Henry , Hall David A
Published: January 2020

Glucose concentration may be determined enzymatically by a glucose-oxidase procedure in which the amount of oxygen depletion from a solution saturated with oxygen is observed. The difference between the initial and final oxygen levels as detected by a polarographic oxygen analyzer is a measure of glucose concentration. Blood is sampled continuously by means of a double-lumen catheter inserted into an arm vein and connected to the flow system. A peristaltic proportioning pump then propels glucose-oxidase reagent and the blood-heparin mixture through a dialyzer. The reagent-dialysate mixture passes through a 1-min. delay coil before passing to the polarographic oxygen sensor. Glucose concentration is proportional to the oxygen depletion in the mixture flowing past the sensor. The studies outlined in this paper describe work directed towards the development of a miniature system intended for continuous monitoring and control of blood-glucose level.
Use of Constant Temperature and Sodium Borohydride in the Trihydroxyindole Method for Catecholamines
Authors: Gerst Elizabeth Carlsen , Steinsland Odd S , Walcott William W
Published: January 2020

Small temperature variations during fluorescent analysis with the trihydroxyindole method can introduce significant errors in the measurement of 15µg./L. or less of epinephrine or norepinephrine. To minimize temperature differences, we have devised a simple, constant-temperature system for the Farrand fluorometer.

Decomposition of ascorbic acid prior to and during analysis also must be prevented. Sodium borchydride was found to be an effective stabilizing agent that contributes negligible fluorescence.These modifications minimize or eliminate much of the difficulty previously encountered in the use of the trihydroxyindole method.
A Quantitative Procedure for the Determination of Nitrofurantoin in Whole Blood and Plasma
Authors: Conklin John D , Hollifield Richard D
Published: January 2020

A rapid, quantitative procedure for the determination of nitrofurantoin in 0.5 ml. of whole blood and plasma is presented. The method has a sensitivity of 2 mg./L., with recoveries of 95-100%. The absorbance-concentration curve is linear to 60 mg./L.
Light Sensitization and Peroxides in Sweat
Authors: Seutter E , Sutorius Annelies H M , Govaert F J
Published: January 2020

Mucopolysaccharides which can be described as relatively stable peroxides were isolated from the sweat of 2 light-sensitive patients. The mucopolysaccharides have been characterized by infrared absorbance in KBr at 867 cm.-1 Upon grinding of the Pellet, this absorbance disappears and gives a stronger one at 848 cm.-1
Some Variables Which Influence the Activated Partial Thromboplastin Time Assay
Authors: Lenahan Jane G , Phillips George E
Published: January 2020

Variables that influence results in the activated partial thromboplastin time assay, are the material used as the activator, its concentration and contact time with the plasma, and varying concentrations of calcium chloride. A reliable and reproducible assay system is described.
Determination of Iron in Serum or Plasma by Atomic Absorption Spectrophotometry
Authors: Rodgerson Denis O , Helfer Ray E
Published: January 2020

The determination of serum iron has been shown to be feasible by the use of a modified single-beam atomic absorption spectrophotometer. The effect of interfering substances is eliminated by the use of standards prepared in physiological concentrations of protein. Average percentage recovery of added iron was 97.9 with an over-all coefficient of variation of 1.6%. Disparities between samples due to the effect of unequal viscosities and flow rates were overcome by the integration of the record curve generated by a measured volume of sample. Comparison between the method presented and a colorimetric procedure gave a higher mean value and normal range for plasma quantitated by atomic absorption spectrophotometry.
Investigation of a Potential Source of Difficulty in the Use of the AutoAnalyzer
Authors: Davis H A , Sterling Rex E , Wilcox Alan A , Waters William E
Published: January 2020

An investigation of the deleterious action of alkaline ferricyanide on the glass heating coil of the AutoAnalyzer showed not only an increase in fragility of the coil with use but a substantial increase in coil volume, a change which can cause standard readings to exceed acceptable limits.
Osmolality of Normal Human Saliva at Body Temperature
Authors: Sawinski Vincent J , Goldberg Allen Fred , Loiselle Raymond J
Published: January 2020

Osmotic pressure of unstimulated mixed saliva from young adult males was measured by a vapor pressure osmometer. Results on 92 fresh samples showed a normal range of 21-77 mosm./L., whereas 90 frozen samples had a normal range of 0-76 mosm./L. A significant difference (p < 0.001) existed between the 2 groups.
Urinary Chorionic Gonadotrophin Determination
Authors: Watson Derek
Published: January 2020

Successful laboratory tests for early pregnancy utilize the endogenous production and excretion of chorionic gonadotrophin (CG). There is wide variation in sensitivity and specificity of various biological and commercially available immunochemical methods for determining urinary CG levels. Normal values for immunochemically reactive CG during the first trimester of pregnancy are given.

Serial determinations of CG have diagnostic value in assessing various abnormal pregnancy states. An abnormally increased urinary output of CG is observed in some neoplasms—e.g., chorionepithelioma, and a rapidly rising CG level is strongly suggestive of molar pregnancy. Urinary CG levels falling below the normal range mayindicate an ectopic pregnancy or an inevitable, incomplete, or "missed" abortion.

The immunochemical CG determination also offers a sensitive, simple, and convenient routine method for following patients who have been treated for hydatidiformmole or chorionepithelioma.
Determination of Uric Acid
Authors: Nishi H Harold
Published: January 2020

The Archibald colorimetric procedure for determination of uric acid has been adapted for automation. The major differences from the original manual procedure after sodium hydroxide treatment of the serum sample are neutralization with hydrochloric acid and dialysis of the serum instead of precipitation to remove protein. At the rate of 40 samples per hour, the automated procedure shows good correlation with the manual procedure.
Urinary Coproporphyrin Isomer Distribution in the Dubin-Johnson Syndrome
Authors: Koskelo Pentti , Toivonen Ilkka , Adlercreutz Herman
Published: January 2020

Urinary coproporphyrin isomer distribution was studied in 13 patients suffering from the Dubin-Johnson syndrome and several control groups. In patients with the Dubin-Johnson syndrome the isomer distribution was quite the reverse to that of normal persons. The urinary isomer distribution was in the normal range in patients with Gilbert's syndrome, hemolytic jaundice, and fatty liver. In many patients with different acute and chronic liver diseases, a clear deviation from the normal urinary isomer distribution was seen. There was, however, no overlapping with the Dubin-Johnson syndrome. Even the fecal coproporphyrin isomer distribution deviated significantly from the normal in favor of Isomer I.
Automated Atomic Absorption Spectrophotometry
Authors: Klein Bernard , Kaufman James H
Published: January 2020

A procedure is described for the automated simultaneous determination of serum calcium and phosphate. Calcium is assayed by atomic absorption spectrophotometry. Phosphate is determined by the molybdenum blue reaction in an improved flow system with a more sensitive reducing agent.
Lactate Dehydrogenase Isoenzymes
Authors: Krieg Arthur F , Rosenblum Lawrence J , Henry John B
Published: January 2020

Five lactate dehydrogenase isoenzymes are normally observed in human serum: H4 (LDH1), H3M (LDH2), H2M2 (LDH3), HM3 (LDH4), and M4 (LDH5). This study presents evidence that these isoenzymes vary in the ratio of LDH activity (pyruvate → lactate) to LDH activity (lactate → pyruvate).
Rapid Enzymatic Measurement of Blood Lactate and Pyruvate
Authors: Marbach Edward P , Weil Max Harry
Published: January 2020

A modification of enzymatic technics for measurement of concentrations of lactate and pyruvate in blood is described. A common protein-free filtrate is prepared by adding blood directly to cold 5% metaphosphoric acid. Theoretical yields are obtained. Recoveries for lactate range from 98 to 102% and for pyruvate from 97 to 104%. Assay of both lactate and pyruvate is simplified and has a high order of reliability. Since both analyses are completed within a period of 20 mm., the method is especially valuable in the emergent clinical situation in which measurements of lactate and pyruvate are obtained for assessment of the severity of shock and other forms of cardiorespiratory failure.
Recalibration of the Gilford Absorbance Indicator
Authors: Collier H Bruce
Published: January 2020

The Gilford Absorbance Indicator was recalibrated, for absolute absorbance readings, with (1) a U. S. Bureau of Standards calibrated cobalt-blue glass standard; (2) a standard cobalt ammonium sulfate solution at 512 mµ (3) standard potassium chromate solutions at 373 mµ These three standards agreed with 1%. Readings on the indicator's absorbance scale had decreased by about 7% over 2 years.
Structure of Sickle Cell Hemoglobin and Molecular Mechanism of the Sickling Phenomenon
Authors: Murayama Makio
Published: January 2020

Precision scale models of sickle cell hemoglobin molecules indicate that the genetic substitution of valine for glutamic acid at the sixth position in the two beta chains allows an intramolecular hydrophobic bond to form. This changes the conformation in such a way as to allow molecular stacking. Results of subjection of Hb S solution to temperature change, to high hydrostatic pressure, and to propane are consistent with the presence of such a bond. Examination of sickled erythrocytes in a magnetic field and in polarized light indicates that the Hb S molecules are aligned in situ. Filaments interpreted as hollow cables of six Hb S monofilaments have been demonstrated by electron microscopy.
An Improved Extraction Procedure for the Determination of Triglycerides and Cholesterol in Plasma or Serum
Authors: Ryan Will G , Rasho Oshana M
Published: January 2020

A simple method of preparing extracts of plasma or serum suitable for determination of both triglycerides and cholesterol is described. Its chief advantage over present procedures is in a considerable saving of time and labor involved in the preparation of large numbers of samples. The method appears to give a more complete extraction of glycerides and compares favorably with existing methods of extracting cholesterol.
A Simple Method for the Determination of Lipoprotein Lipase
Authors: Stutman Leonard J , Dolliver Marilyn
Published: January 2020

A rapid method for determining the in-vivo effect of small amounts of intravenous heparin utilizing thin-layer chromatography is presented. A dense band of stainable fatty acids appears and represents nonesterified acids after the fatty acid esters have been hydrolyzed by lipoprotein lipase and determines, therefore, whether the enzyme is activated by heparin.
Effects of Age and Rearing Conditions of Macacca mulatta on Blood Proteins and Protein-Bound Carbohydrates
Authors: Beasley John W , Seal Ulysses S
Published: January 2020

Measurements of blood constituents were made on monkeys, Macacca mulatta, reared in conditions of severe social isolation which are known to lead to behavioral deficits in adult life. Alterations were found in the levels of hemoglobin, total plasma protein, and haptoglobin, while the levels of fibrinogen and protein-bound carbohydrates were identical with controls. Differences among the deprived monkeys did not resemble differences found among human schizophrenic patients. An effect of age on some of these measures in the rhesus monkey also was noted.
The Use of a Reagent Gel To Locate LDH Isoenzymes Separated on Cellulose Acetate Membranes
Authors: Myers R C , Van Remortel H
Published: January 2020

In a technic for locating the isoenzymes of LDH following electrophoresis on cellulose acetate membranes, the membrane is laid on an agar gel containing all of the necessary reagents.
A New and Rapid Method for the Determination of Glucose by Measurement of Rate of Oxygen Consumption
Authors: Kadish Arnold Henry , Litle Robert L , Sternberg James C
Published: January 2020

Glucose levels in serum, plasma, and urine are determined rapidly and conveniently by a new glucose oxidase method employing a polarographic oxygen sensor with a circuit modified to record the rate of oxygen consumption. The maximum apparent rate of oxygen consumption relative to the rate obtained with a glucose standard provides a direct measure of the glucose level in the sample; results are obtainable within 20 sec. after sample (100 µl.) addition and within 3 min. after a blood sample is withdrawn from a patient. Interferences associated with prior colorimetric glucose oxidase methods are avoided by measuring oxygen consumption instead of hydrogen peroxide formation. The method is described and results are presented showing a standard deviation of less than 1.5% on replicate determinations and a bias of 1% with respect to data obtained on the same samples by the automated ferricyanide method.
Use of Nuclear Magnetic Resonance in Determining Molecular Structure of Urinary Constituents of Low Molecular Weight
Authors: Dean John A
Published: January 2020

Nuclear magnetic resonance is applied to elucidate organic compounds of low molecular weight that occur in urine. Spectrums of specific compounds are shown, as are closely related compounds, to illustrate NMR principles and their application in practice.
Recovery of Uric Acid from Serum
Authors: Fales Frank W
Published: January 2020

Uric acid added to serum is incompletely recovered in tungstic acid filtrates of serum. Contrary to previous views, the poor recovery is not the result of the adsorption of uric acid upon the precipitated protein, nor is it the result of the presence in the filtrates of inhibitors of the color-forming reaction between the sodium carbonate and phosphotungstic acid reagents, and the uric acid. Evidence is presented which implicates adsorption on filter paper as the cause of the poor recovery of uric acid from acid filtrates. Excellent recoveries are obtained when the protein precipitated by tungstic acid is removed by centrifugation.
Micromethod for Tocopherol Determination in Blood Serum
Authors: Fabianek J , Defilippi J , Rickards T , Herp A
Published: January 2020

An improved microprocedure for the determination of tocopherol in blood serum is reported. Tocopherol is oxidized by ferric chloride and the pink complex of ferrous ions with 4,7-diphenyl-10,10-phenanthroline (bathophenanthroline) is determined spectrophotometrically. The test is more sensitive than colorimetric methods using 2,2',2''-tripyridine,2,2'-bipyridine (bipyridyl) or 2,4,6-tripyridyl-s-triazine. The use of phosphoric acid prevents the photochemical reduction of ferric chloride and also reduces interference of carotene to a minimum. The amount of carotene oxidized by ferric chloride in the first 5 min. is negligible in the presence of bathophenanthroline. As its further oxidation is stopped by phosphoric acid, the contribution of carotene to the ferrous-bathophenanonthroline complex is insignificant.
A Shortened Method for the Fluorometric Determination of Phenylalanine
Authors: Ambrose John A
Published: January 2020

As a result of a study of the classic ninhydrin reaction with amino acids (which results in the production of Ruhemann’s purple), and the fluorescence reaction occurring between ninhydrin and phenylalanine in the presence of a dipeptide, the initial incubation period in the fluorescence reaction was shortened from 2 hr. to 16 min. This improvement in the fluorometric method for the determination of phenylalanine was accomplished by (1) decreasing the initial incubation pH from 5.8 to 5.0, and (2) increasing the incubation temperature from 60° to 85°. A study of the effect of pH on the fluorescence level in both the acid and alkaline reactions demonstrated the presence of fluorescence pH plateaus. These plateaus indicate that the fluorescence level was relatively unaffected by a change in pH within specified ranges. A study of the specificity led to the discovery that the inclusion of a peptide control was necessary to correct for one type of nonspecific fluorescence. To make this correction, it was necessary to add the reading of the serum blank to that of the reagent blank, and to subtract this total from the sample reading.
A Single Column Method for the Determination of Urinary δ-Aminolevulinic Acid
Authors: Sun Mu-Wan , Stein Edward , Gruen Frances W
Published: January 2020

A simple method for determination of urinary δ-aminolevulinic acid is described. Its advantage over procedures now in use is in the utilization of a single ion-exchange column instead of two ion-exchange columns, with resulting saving of time, labor, and material. The method is accurate and useful in screening for lead poisoning.
A Simple Nonchromatographic Determination of Glycerophosphatide in Serum
Authors: Rosenthal Arthur F , Han Stella Ching-Hsien
Published: January 2020

Glycerophosphatide phosphorus is determined in ether-methanol extracts of blood serum by a nondigestive procedure which utilizes a sulfuric-periodic acid reagent. Sphingomyelin phosphorus is not liberated. The method shows good agreement with the sum of lecithin, cephalin, and lysolecithin phosphorus when the lipids are separated by thin-layer chromatography. Lecithin in an artificial lipid mixture is determined readily. The ether-methanol extraction gives results comparable to that of a standard chloroform-methanol extract.
Oxygen Flask Decomposition of Blood Serum: Application To PBI Determination
Authors: Zaroda Ray A
Published: January 2020

A novel approach is presented for converting organically bound iodide of blood serum into the corresponding inorganic state for protein-bound iodine measurement. The technic consists of oven-drying 1 ml resin-treated serum in a collodion-impregnated filter paper holder, burning the dried sample in a Schoniger oxygen flask, and absorbing the decomposition products in a suitable absorbing medium. The extract is then submitted to an automated, analytic, photometric assay method based on the iodide-iodine catalysis of the cerium-arsenic reaction. The procedure eliminates the possibility of cross-contamination because each sample is handled in a separate, sealed reaction flask. The method yields reproducible results which compare favorably with PBI technics currently in existence. The investigation represents the first known instance of the Schoniger process being applied to iodine determinations in the 1-10 [Lg/100 ml range.
An Automated Method for the Measurement of Plasma Hemoglobin
Authors: Spiegel Herbert E , Tonchen Alice E
Published: January 2020

An automated method for the determination of hemoglobin concentrations normally present in plasma is described. The method was developed from the manual technics of Crosby and Furth, and Hanks (2, 7). The procedure is based on the development of a green chromogen which results when hemoglobin reacts with benzidine and hydrogen peroxide. The results of the automated method compared well with the manual procedure. In addition, there was good precision over the concentration range of 1-5 mg/100 ml. Normals were found to range between 0.8 to 4.6 mg/100 ml with a mean of 2.4 mg/100 ml.
Automated Fluorometric Method For The Determination of Serum Calcium
Authors: Fingerhut Benjamin , Poock Alfred , Miller Henry
Published: January 2020

An automated fluorometric procedure for serum calcium has been developed which can be used for a wider variety of pathologic serums than the automated fluorometric and colorimetric technics generally being used at present. The method is based upon measurement of the fluorescence produced by calcein with calcium in a serum dialysate. Results are in good agreement with the Clark-Collip procedure. Recovery experiments averaged 98-101%. The standard deviation for duplicate determinations averaged ±0.20 mg/100 ml.
Direct Manual Determination of Serum Total Cholesterol with a Single Stable Reagent
Authors: Wybenga D R , Pileggi V J , Dirstine P H , Giorgio John Di
Published: January 2020

We describe a simple, direct, and specific manual method for quantitative determination of total cholesterol in serum. In the method, which requires no extraction of the serum, a single stable reagent and 50 µl of sample is used. Serum cholesterol concentrations determined by this method did not differ statistically from those obtained by the reference method of Abell et al. Hemoglobin, bilirubin, and γ-globulin do not interfere unless present at markedly supranormal concentrations. Inter-run precision is about ±3% (95% confidence limits).
Determination of Amphetamine, Methamphetamine, and Related Amines in Blood and Urine by Gas Chromatography with Hydrogen-Flame Ionization Detector
Authors: Lebish Paul , Finkle Bryan S , Brackett J W
Published: January 2020

A sensitive gas-chromatographic method suitable for clinical and forensic purposes is presented for measuring methamphetamine, amphetamine, and other phenethylamines in blood and urine. When testing blood, we include a known quantity of a homologous standard, n-propylamphetamine hydrochloride, in the tungstic-acid solution used to precipitate blood proteins; the acid filtrate is washed, alkalinized, and extracted with ether. Extracted phenethylamines are converted to the corresponding acetamides, which are then concentrated and gas-chromatographed. The method for urine is similar except the known quantity of n-propylamphetamine hydrochloride is added to the sample, the protein precipitation is omitted, and chloroform is the extracting solvent. Suitable tests are described for the more stringent confirmation of amphetamine and methamphetamine required for court testimony. Retention data obtained from both a polar and a nonpolar column packing are presented for over 50 compounds related to phenethylamine.
On-Line Dilutor for Use with Flame Photometers
Authors: Habig R L , Williamson W R
Published: January 2020

This note describes a reliable, convenient way to provide automatic, on-line dilution of samples for flame photometry. The method applies to any flame photometer that has a vertical aspirating needle
Cerebrospinal Fluid Proteins: Concentration by Membrane Ultrafiltration and Fractionation by Electrophoresis on Cellulose Acetate
Authors: Windisch Rita M , Bracken Mark M
Published: January 2020

A membrane ultrafiltration system is described and evaluated for rapidly concentrating cerebrospinal fluid before cellulose acetate electrophoresis. Results with this system were compared with those obtained by use of vacuum ultrafiltration through a collodion sac. Mean values for the various protein fractions were determined for normal cerebrospinal fluid. The results, in percentage of total protein, after membrane and vacuum ultra-filtration concentration were, respectively: 3.8 and 5.2% prealbumin, 65.5 and 63.9% albumin, 3.6 and 3.6% ∝1-globulin, 6.8 and 6.1% arglobulin, 12.4 and 12.9% a-globulin, and 7.6 and 8.2% γ-globulin.
Rapid Method for Determining Alkaline Phosphatase Activity in Serum with Thymolphthalein Monophosphate
Authors: Roy A V
Published: January 2020

The use of sodium thymolphthalein monophosphate in measuring alkaline phosphatase activity of serum is described. Thymolphthalein liberated in the reaction is conveniently measured by raising the pH of the medium, which produces a color and also stops the hydrolysis. The effects of pH, kind and molarity of buffer, temperature, and enzyme and magnesium con-centrations were studied. Results by this procedure correlate well with those obtained by a standard procedure in which liberated p-nitrophenol is de-termined. Advantages of the present method include excellent linearity, high precision, short incubation, and reagent stability.
Plasma Fibrinogen: Determination, Normal Values, Physiopathologic Shifts, and Fluctuations
Authors: Grannis George F
Published: January 2020

The determination of plasma fibrinogen, either as clottable protein or protein precipitable with glycine or ammonium sulfate, is evaluated in terms of principles of analysis, analytic error, normal and abnormal ranges, physiologic stability, and pathologic variability of fibrinogen concentration. The quantitative comparison of analytic error, population ranges, and individual variability should permit more precise interpretation of clinical data than previously has been possible.
Determination of Oxalic Acid in Biological Material
Authors: Hodgkinson A
Published: January 2020

The properties of oxalic acid are reviewed, together with the use that may be made of these in various methods of oxalate analysis, which are critically compared. Information is given on the oxalate content of biological fluids, urinary calculi, tissues, and foods.
Normal Concentrations of Lactate, Glucose, and Protein in Cerebrospinal Fluid, and the Diagnostic Implications of Abnormal Concentrations
Authors: Pryce J D , Gant P W , Saul K J
Published: January 2020

Normal values for glucose, lactate, and protein in cerebrospinal fluid have been established and the relationships among them studied. Normal protein concentration is related to age. Glucose and lactate values are correlated with each other and with sex and age. By the technique of pattern appreciation, these estimations provide a useful confirmatory test for cerebrovascular accidents and for differentiating intracranial hemorrhage from other types of accident and from bloody spinal fluid taps, and they have considerable prognostic value in assessing the milder cases. They also have a restricted value in certain other conditions.
A Computer-Assisted Electrode System for Measuring Blood pH, pO2, pCO2, Sodium, and Potassium
Authors: Neff G W , Radke W A , Sambucetti C J , Widdowson G M
Published: January 2020

An experimental automatic electrode system was constructed to determine the feasibility of making routine determinations of blood pH, pO2, pCO2, sodium, and potassium in intensive care units. The equipment standardizes itself automatically every 25 min, and is self-cleaning after a blood specimen has been analyzed. The analyzer is connected on-line to an IBM 1800 computer on an interrupt basis. There was no significant difference between the results for pH, pO2, and pCO2 obtained with this machine and those by manual methods. The precision obtainable for the five determinations is given. The relationship between blood and plasma sodium and potassium activities determined with the glass electrodes and plasma sodium and potassium concentrations determined by flame photometry is discussed.
An Automated Fluorometric Method for Determination of Malate Dehydrogenase Activity in Serum
Authors: Schwartz P L , Burns H J
Published: January 2020

An automated system for the sensitive, reproducible determination of malate dehydrogenase activity in serum is described and evaluated. After incubation of serum at 25°C and double dialysis, fluorometry is used to measure the disappearance of NADH during reaction. Certain precautions are necessary to maintain the stability of NADH and oxaloacetate and to assure washout of adsorbed serum components from the system. Control serum (Enza-trol) is used as an enzyme reference material. Results from the automated method agree well with those from an independent manual method. Replicability is excellent, and results from samples stored at 4° or -20°C are essentially the same as those from fresh samples. A mean value of 36.6 ± 8.5 U of malate dehydrogenase per liter was obtained on sera from 34 healthy adults, a value that agrees well with normal values obtained by others.
Ultraviolet-Absorbing Components of Urine from Mentally Retarded Children. III
Authors: Lis Elaine W , Lis Adam W , deHackbeil Konrad F
Published: January 2020

Urinary excretion of ultraviolet light-absorbing end-products of metabolism was studied in mentally retarded children and a single plasma dialysate from a nephrectomized adult male. Aliquots were fractionated on Dowex-1 columns with 1 mol/liter and 4 mol/liter formic acid gradients. Resolved peaks were pooled and suitable aliquots submitted to two-dimensional ascending paper chromatography. Among previously unidentified components, 5-alkyl substituted uracil was found in the plasma dialysate obtained from the nephrectomized male. Citrullinemia was shown to be associated with a high excretion of what we believe to be orotic acid. Another familial disorder of central nervous system function complicated by mental retardation and aggressive destructive behavior (not Lesch-Nyhan syndrome) was characterized on the basis of a urinary metabolic profile. In some mentally retarded children, excretion of creatinine varied enormously. Creatinine, submitted to a systematic, quantitative procedure for assessing the behavioral and physiologic state in mice, had properties of a weak minor tranquilizer; its sedative attributes may be responsible for light sleep preconditioning.
Use of Metamizol in Determining Phospholipid Phosphorus in Serum
Authors: Guirgis Fayez K , Habib Yehia A
Published: January 2020

Metamizol (methampyrone) is used as the reducing agent for determination of phospholipid phosphorus in serum. The analysis, rapid and easy, yields results that agree well with those obtained by well-established procedures.
Evaluation of Light-Scattering Index (Nephelometry) for Assessing Serum Triglycerides and Lipoprotein Phenotypes
Authors: Helman Edith Zak , Blevins Eleanor J , Gleason Irene O
Published: January 2020

Light-scattering measurements (nephelometry) of serum after filtration through appropriate filters is a rapid method for physically determining triglyceride concentrations and lipoprotein phenotypes. A correlation coefficient of greater than 0.9 was obtained when aliquots of the same specimen were tested for triglycerides by light scattering in an Aminco-Bowman Spectrophotofluorometer and by a chemical (Van Handel and Zilversmit) method. Lipoprotein phenotyping by agarose gel electrophoresis and by light-scattering measurement corresponded excellently. In equivocal cases, nephelometric results agreed better with the triglyceride and cholesterol data than did the electrophoretic method.
Application of the Phenol—Hypochlorite Reaction to Measurement of Ammonia Concentrations in Kjeldahl Digests of Serum and Various Tissues
Authors: Shahinian Antranik H , Reinhold John G
Published: January 2020

Conditions have been defined that enable the use of nitroprusside as a catalyst for the phenol-hypochlorite reaction when the latter is applied to measurement of nitrogen in Kjeldahl digests containing mercury. This is accomplished by lowering the concentration of mercury to a range where it remains effective in accelerating the destruction of organic matter during digestion but no longer reacts with nitroprusside. In addition, the use of minimal concentrations of nitroprusside diminishes further the possibility of interference by mercury and has the added advantage of decreasing the pH dependence of indophenol blue formation. The sensitivity of the reaction makes possible measurement of nitrogen in very small samples with relatively short digestion times.
Abnormal Concentrations of Nickel in Serum in Cases of Myocardial Infarction, Stroke, Burns, Hepatic Cirrhosis, and Uremia
Authors: McNeely Michael D , Sunderman F William , Nechay Maria W , Levine Howard
Published: January 2020

Nickel concentrations were measured by atomic absorption spectrometry in sera. The mean concentration of nickel in sera of 47 healthy adults was 2.6 SD ± 0.8) µg/liter. Abnormally high mean concentrations (µg/liter) of serum nickel were found in patients with: (a) acute myocardial infarction (13-36 h after onset), mean = 5.2 ± 2.8, N = 33, P <0.001; (b) acute stroke (37-72 h after onset), mean = 4.5, N = 12, P <0.005; and (c) acute burns (>25% body surface, 37-72 h after injury), mean = 7.2, N = 3, range = 4.1-10.9. Diminished mean concentrations of serum nickel were found in patients with: (a) hepatic cirrhosis, mean = 1.6 ± 0.8, N = 18, P <0.005; and (b) chronic uremia, mean = 1.7 ± 0.7, N = 12, P = <0.005. Normal mean concentrations of serum nickel were found in patients with: (a) acute myocardial ischemia without infarction (13-36 h after onset), mean = 3.3 ± 1.6, N = 22; (b) acute trauma with fractured bones (13-36 h after injury), mean = 2.7 ± 0.9, N = 19; (c) acute delirium tremens (13-36 h after admission), mean = 2.3 ± 0.9, N = 25; and (d) muscular dystrophy, mean = 2.3 ± 1.4, N = 10. In sera collected from 12 mothers immediately after normal delivery, the mean concentration of nickel was 3.0 ± 1.2 µg/liter, the same values as for sera from the umbilical cords of their 12 full-term infants.
Rapid Column-Chromatographic Measurement of Orotic Acid
Authors: Bellinger John F , Buist Neil R M
Published: January 2020

A rapid anion-exchange column-chromatographic method for measuring orotic acid is described. The method is of value in screening or quantitating abnormal amounts of this compound, but cannot be used to measure the small amounts normally present in urine.
Automated Procedure for Determination of Bilirubin in Human Sera
Authors: Cooper J D H
Published: January 2020

An automated procedure is presented, based on the method of Bruchner [Amer. J. Clin. Pathol. 32, 513 (1959)], for determination of both total and conjugated bilirubin. The method is standardized by use of bilirubin in human serum, which is stabilized by a mixture of formamide and cyanide. Hemoglobin does not interfere at concentrations less than 500 mg/100 ml, and the effect of lipemia is minimized.
A Digital pH Stat for Automated Kinetic Analysis
Authors: Karcher Raymond E , Pardue Harry L
Published: January 2020

A "pH stat" that spectrophotometrically monitors pH and electrolytically generates either acid or base has been developed to follow the rates of certain enzyme-catalyzed reactions. The pH is monitored by coupling a pH indicator to the main reaction. As reaction proceeds, the instrument coulometrically pulses titrant into the photometer cell as required to maintain a constant pH. Generation is accomplished with Pt and Ag-AgCl electrodes. Constant-current conditions are used so that a given number of pulses corresponds to a constant reaction interval. A series of flip-flops counts the pulses as they occur; a timing circuit records the time required to generate a set number of pulses. A reciprocal time computer provides automated readout in units of absolute enzyme activity. Initial experiments on the acetylcholinesterase system (pH 7.60) show linear enzyme dependence curves with scatter of 2% or less. The change in pH during a single cycle is less than 0.05 units and the precision for replicate samples is about 2%.
Influence of Statistical Method Used on the Resulting Estimate of Normal Range
Authors: Reed Allen H , Henry Richard J , Mason William B
Published: January 2020

The choice of statistical method can greatly influence the calculated normal range apart from any biological or chemical considerations. Nonparametric normal range estimates are, for practical purposes, as accurate as estimates that assume the distribution of data to be gaussian or loggaussian when the distribution assumed is true. When data are not distributed as assumed, nonparametric estimates are more accurate.
An Automated, Fluorometric Procedure for Determining Serum Lipase
Authors: Fleisher Martin , Schwartz Morton K
Published: January 2020

Currently available routine assays for lipase (glycerol ester hydrolase EC 3.1.1.3) are lengthy and laborious, and may utilize nonspecific substrates. An automated continuous-flow procedure has been developed for the fluorometric determination of serum lipase activity. This involves the use of a fluorescein fatty acid ester, monodecanoyl fluorescein (MDF), as substrate. This compound is not fluorescent, but one of its hydrolytic products, fluorescein, is intensely fluorochromatic. Under the conditions of the assay, in which 0.5 mmol of MDF is used per liter, the hydrolysis is linear with time and follows zero-order kinetics through the hydrolysis of at least 35% of the substrate. Determinations are carried out on 0.1 ml serum at the rate of 60 assays/hour. By this assay, mean activity in the serum of normal persons is 751 units (SD, 38 units).
A More Sensitive Spectrophotometric Method for Determination of Isoniazid in Serum or Plasma
Authors: Eidus Leslie , Harnanansingh Anita M T
Published: January 2020

A sensitive spectrophotometric method is described for determining isoniazid in serum or plasma. It is extracted from biological fluids by a mixture of organic solvents and re-extracted into hydrochloric acid. In this medium, isoniazid reacts with trans-cinnamaldehyde to form a derivative absorbing maximally at 340 nm. The method is five times more sensitive than published procedures in which vanillin or piperonal is used as coupling reagent for the estimation of isoniazid.
Antibodies to Testosterone-3-Bovine Serum Albumin, Applied to Assay of Serum 17β-ol Androgens
Authors: Chen Jeffrey C , Zorn Elinor M , Hallberg Marvin C , Wieland Ralph G
Published: January 2020

Testosterone was conjugated to bovine serum albumin at carbon 3, and antibodies to this conjugate were developed in virgin female rabbits. This antiserum, diluted 1:3200, was used to measure testosterone. With tritiated testosterone and anti-rabbit γ-globulin as the second antibody, a doseresponse curve was obtained for doses in the range 0.1-10 ng. The antibody cross-reacts extensively with dihydrotestosterone, so that dihydrotestosterone is measured with testosterone in extracted but unchromatographed serum. Results for pooled serum from men, as measured repeatedly by radioimmunoassay and competitive binding assay for testosterone, agreed well. Seventeen normal men had serum 17β-ol androgen concentrations of 667 ng/100 ml (SD, ±248); seventeen normal, menstruating women had a mean concentration of 69 ng/100 ml (SD, ±18). Values for 17β-ol androgens in adolescent males agreed reasonably with testosterone values reported by other investigators. Values are presented for patients with various androgenic disorders. This procedure is easy; many samples can be processed at one time.
Modified Semiautomated Method for Serum Thyroxine
Authors: Yee Hugh Y , Bowdell Judy , Jackson Bobette
Published: January 2020

A modified semiautomated technique is described for serum thyroxine. The AutoAnalyzer system used is both sensitive and "noise" free. Two screening steps are presented that minimize possible contamination of the AutoAnalyzer system. Sampling rate is 50/h and 1 ml of serum is required.
A Reliable Spot Test for Mucopolysaccharidoses
Authors: Berman E R , Vered J , Bach G
Published: January 2020

A new spot test for detecting excessive excretion of mucopolysaccharides in urine has been used with a group of 17 patients. Reliability of the test was evaluated by correlating clinical findings with qualitative and quantitative analyses of urinary mucopolysaccharides. Normal controls, with 3.8 to 10.0 mg of uronic acid in this form per liter of urine, gave negative spot tests; all cases of clinically diagnosed mucopolysaccharidoses (MPS) I, II, and III (Hurler’s, Hunter’s, and Sanfilippo’s syndromes, respectively) gave strongly positive ones. Two patients (female siblings) with Morquio’s syndrome (MPS IV) also gave positive spot tests, which were somewhat less intense than those given by patients with MPS I, II, or III. The test for Morquio’s syndrome, positive with fresh urine, was essentially negative with samples at -26°C for three months or longer. A group of seven patients having various degrees of skeletal deformities, mental retardation, dwarfism, or corneal opacities, but not fitting the presently accepted classification of mucopolysaccharidoses, gave negative spot tests, and chemical analyses of their urinary mucopolysaccharides showed normal patterns of excretion.
An AutoAnalyzer Procedure for Serum Iron and Total Iron-Binding Capacity, with Use of Ferrozine
Authors: Yee Hugh Y , Zin Anastasia
Published: January 2020

An AutoAnalyzer method has been developed in which the recently introduced reagent for iron, 3-(2-pyridyl)-5,6-bis(4-phenylsulfonic acid)-1,2,4-triazine ("ferrozine"), is used. With the Technicon colorimeter or Gilford 300-N spectrophotometer in use, sampling rates may be 30/h or 50/h, respectively. Sample volume is 0.8 ml, and measurements are made at 560 nm. A procedure for measuring total iron-binding capacity is also described.
Automated Procedure for Assay of 2,3-Diphosphoglycerate in Red Cells by Measuring Enzymatically Released Inorganic Phosphorus
Authors: Powell James B , Emery Clarence E , Peyton Gaylon A
Published: January 2020

An automated technique is reported for measuring erythrocyte 2,3-diphosphoglycerate (DPG). We have automated a specific method, in which the DPG phosphatase activity of phosphoglycerate mutase is used and potentiated by phosphoglycolate. Precision, accuracy, recovery, and comparability with a reference method are discussed.
Automated Quantitative Immunochemical Analysis of Human Immunoglobulins
Authors: Markowitz Harold , Tschida A R
Published: January 2020

A commercial automated continuous-flow procedure for estimating specific serum proteins has been evaluated for use in determination of IgG, IgA, IgM (both 19S and 7S), α1-antitrypsin, and cerebrospinal fluid proteins. Results of the automated procedure correlate well with manual methods, but are much more precise. Estimation of 7S IgM by the automated method is more accurate than estimation by radial immunodiffusion, because concentrations of 7S IgM are not spuriously elevated.
Simple, Rapid, Kinetic Method for Serum Creatinine Measurement
Authors: Lustgarten Jack A , Wenk Robert E
Published: January 2020

A study of the reaction between creatinine and alkaline picrate confirmed that there is a linear relation between absorbance change and creatinine concentration over the entire clinical range of values. The specificity and accuracy of the method are comparable to that of the end-point Jaffé reaction with deproteinization. The test is somewhat imprecise in the low range, but the simple, rapid procedure is appropriate for the monitoring of patients with glomerular disease and those undergoing therapeutic dialysis.
Simple Method for Determination of Urinary δ-Aminolevulinic Acid as an Index of Lead Exposure
Authors: Tomokuni Katsumaro , Ogata Masana
Published: January 2020

A simple method is described for the quantitative analysis of urinary δ-aminolevulinic acid. 2-Methyl3-carbethoxy-4-(3-propionic acid) pyrrole, produced by the condensation of δ-aminolevulinic acid with ethyl acetoacetate, is almost completely extracted from an aqueous solution with ethyl acetate without resorting to ion-exchange column chromatography. The pyrrole is determined colorimetrically by treating an aliquot of the extract with a modified Ehrlich’s reagent.
Effects of Various Medications on Values from the HABA and BCG Methods for Determining Albumin
Authors: Notrica Solomon , Miyada Don S , Baysinger Vern , Nakamura Robert M
Published: January 2020

We investigated the effects of acetylsalicylic acid, salicylic acid, sulfisoxazole, and phenobarbital—at concentrations at or just above those in serum after therapy—on results of the 2-(4'-hydroxyazobenzene) benzoic acid (HABA) and bromcresol green (BCG) methods for measuring serum albumin. Although the HABA method was more prone to such interference, only interference by salicylic acid with the HABA method is significant. Salicylic acid at a concentration of 400 mg/liter decreases the apparent values for HABA-albumin by about 10%.
Tris/Tris·HCl: A Standard Buffer for Use in the Physiologic pH Range
Authors: Durst Richard A , Staples Bert R
Published: January 2020

A buffer solution containing tris(hydroxymethyl)-aminomethane (0.01667 mol/kg) and its hydrochloride salt (0.0500 mol/kg) is proposed as a pH standard for the physiologically important pH range of 7.3 to 7.5. Standard pH values were assigned to this reference solution at temperatures from 0° to 50°C by means of measurements with hydrogen/silver chloride cells without transference. At 37°C, the assigned pH of this buffer solution is 7.382, with a temperature coefficient of -0.026 pH unit per degree Celsius. This new standard is more compatible with biologic fluids than is the previously certified phosphate buffer.
Rapid, Automated, Simultaneous Determination of Serum CO2 and Chloride with the "AutoAnalyzer I"
Authors: Kenny Margaret A , Cheng Mary H
Published: January 2020

A method for simultaneous, automated determination of serum CO2 and chloride is presented, in which the dialyzers of the more expensive AutoAnalyzer II system are combined with the usual components of the AutoAnalyzer I system. Thus, the innovative features of the AutoAnalyzer II system are used at low cost.
Microfluorometry of Glucose-6-Phosphate Dehydrogenase and 6-Phosphogluconate Dehydrogenase in Red Cells
Authors: Lowe Mei Lee , Stella Angelo F , Mosher Beatrice S , Gin Jerry B , Demetriou James A
Published: January 2020

A simple microfluorometric method is described for measuring glucose-6-phosphate dehydrogenase (GPD) and 6-phosphogluconate dehydrogenase (PGD) activities in human erythrocytes. Only 50 µl of whole blood is required. The cells are lysed with digitonin and the rate of NADPH generated in the enzymatic reactions is followed kinetically with a recording fluorometer. GPD activity is measured by subtracting the PGD activity from the combined activities of GPD and PGD. A correction is made for the quenching effect caused by hemoglobin. The entire analysis requires less than 1 h. No significant sex-related difference was observed. Both enzymes are stable at 30°C for seven days in samples collected either with heparin or in Alsever’s solution.