bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of Creatinine in Small Quantities of Plasma
Authors: Martinez Edward , Doolan Paul D
Published: January 2020

Two technics for the determination of creatinine in plasma have been described. One consists of an adaptation of the method reported by Van Pilsum, in which certain modifications dealing primarily with the color reaction have been introduced. This method depends on the conversion of creatinine to methylguanidine and employs the Sakaguchi reaction for guanidine groups. It is highly specific and is recommended when accuracy is the predominant requirement. The method has been employed in experimental studies performed on small animals and in renal clearance studies in which the most accurate approximation of glomerular filtration is needed. The appropriate dilution can be made from the original sample if a high creatinine value is anticipated. A second procedure, consisting of an adaptation of the conventional picric acid method, is described. Although less specific, the method is simple, rapid, and can be performed with conventional equipment. It is recommended for routine use.
Determination of Citrulline in Plasma
Authors: Mockler Mary P , Menebroker Lucille R , Humoller Fred L , Barak Anthony J
Published: January 2020

The Archibald method for the determination of plasma citrulline has been modified to eliminate the dialysis step in order to separate citrulline from plasma proteins. Instead these are precipitated with picric acid and the picrate ion removed by passage through an anion exchange column. By adding phenylhydrazine to the reaction mixture, a color complex is formed which obeys Beer's law throughout the range of concentration studied. Recovery of added citrulline amounted to about 90-110 per cent.
X-Ray Spectroscopy in the Clinical Laboratory
Authors: Natelson Samuel , Sheid Bertrum
Published: January 2020

Chlorine and sulfur are assayed in serum with the X-ray spectrometer. The serum samples are dried in confined spots on a long strip of filter paper. The strip is passed continuously through the X-ray field and the element assayed by the peak of the curve drawn on the recorder. An attachment for the spectrometer is described for this purpose, as well as an instrument for making the confined spots. Results for chlorine in serum are compared with those obtained by mercurimetric titration. The results are comparable as regards accuracy and reproducibility. Using 20 µ1. of serum and the automatic feed, the results for chlorine indicate a reproducibility, by X-ray, of ± 3.4 per cent (2σ).

No significant difference was observed in comparing the values for sulfur obtained by X-ray with those obtained by ashing and treatment with barium chloranilate. The X-ray technic with 25 µ1. of serum is reproducible to ± 2.2 per cent (2σ). Serum was dialyzed against saline and assayed for sulfur content before and after dialysis. The dialyzable sulfur is small in comparison with the total protein sulfur. In comparing normal and pathologic sera with respect to their sulfur-to-protein content ratio it is observed that this varies apparently because the serum globulins contain amounts of sulfur different from serum albumin. The abnormal protein observed in multiple myeloma contains less than half the sulfur of the albumin from the same patient. This was determined by scanning the electrophoretic pattern of the serum for sulfur and protein.

It is pointed out that the X-ray technic is practical for routine analysis in the clinical laboratory in that no reagents are required for total sulfur, chlorine, calcium and potassium; furthermore, only an ultramicrosample is needed and the instrument is easily adapted to automatic operation. Results are comparable with those obtained by conventional methods with regards to accuracy and precision.
Straylight Error in a Spectrophotometer
Authors: Hoch H , Turner Malcolm , Williams R C
Published: January 2020

A method is described for arriving at a calibration equation expressing concentration in terms of absorbancy. This equation is based on the assumption of a constant stray radiant energy or a constant dark current compensation error. The deviation from linearity was found to correspond to 0.1 per cent stray radiant energy at 273 mµ in a Beckman spectrophotometer.
Assay of Fibrinogen in Small Blood Samples
Authors: Wycoff H D
Published: January 2020

A procedure is presented for the assay of fibrinogen in small samples of blood. A 0.2-ml. sample of whole blood is mixed in the syringe with 0.3 ml. of isotonic citrate-phosphate buffer and centrifuged in special tubes in which the cell volume is measured. From these measurements the dilution of the supernatant plasma is calculated. The plasma is assayed for fibrinogen and this result is corrected for dilution. Plasma fibrinogen values obtained in this way are comparable to those obtained with other methods that require larger samples of whole blood.
Study of the Saccharogenic Method for the Determination of Serum and Urine Amylase
Authors: Henry Richard J , Chiamori Neil
Published: January 2020

A modification of Somogyi's saccharogenic method for the determination of amylase activity has been presented for serum and urine. The starch substrate employed is buffered sufficiently to control the pH of sera and urines. A study was made of the effect of varying enzyme and starch concentrations, pH, chloride and buffer concentrations, and temperature. Also studied were various starches and other substrates, several methods for quantitating reducing substances formed, stability of samples, precision, and normal values. Identification of intermediate and end products was made by paperchromatographic technics. Above a limiting concentration of starch, representing saturation of enzyme with substrate, a linear reaction rate was observed for a period of time that was found to be directly related to the initial starch concentration. Kjeldahl's law of proportionality has thus been confirmed for the ra-amylase activity of serum and urine. Evidence is presented that deviation from a linear reaction rate occurs at about the time the starch and high molecular weight dextrins no longer saturate the enzyme. Following this point, hydrolysis of lower molecular-weight sugars gradually becomes the preponderant reaction.
Clinical Applications of Infrared Spectroscopy
Authors: Klein Bernard , Weissman Milton , Berkowitz Judith
Published: January 2020

The infrared absorption spectra of typical prostatic, dental, and salivary gland calculi are presented. Similarly, the spectrum given by typical biliary tract calculi is demonstrated. Examples of the extension of this method of identification to common toxicologic problems are shown. The advantages of the potassium-bromide presseddisk preparation for analyses of these substances in the solid state are indicated and discussed.
Metabolic Characterization of Polymorphonuclear Leukocytes
Authors: Estes Frances L , Austin Nancy S , Gast Joseph H
Published: January 2020

The viability and cellular integrity of polymorphonuclear leukocytes obtained from intraperitoneal exudates are maintained in the absence of serum or added organic material. Under these conditions the endogenous oxygen consumption has a p11 optimum of 7.0 to 7.2. In the presence of glucose the oxygen consumption is inhibited and this inhibition correlates with the concentration of glucose added over a range of 0.2 to 1.0 µM. The inhibition can be overcome in part by prolonged incubation, by the addition of cytochrome C, or by succinate addition.
Factors Affecting the Estimation of Pregnanediol in Human Urine
Authors: Duboff G S , Saraiya H , Behrman S J
Published: January 2020

The chromatographic and spectrophotometric features of the estimation of pregnanediol in urine has been re-evaluated. Spectral data for pregnanetriol and pregnanediol and critical features for the preparation of the activated alumina chromatographic column are given. Pregnanediol excretion patterns of 4 successive menstrual cycles in a female of reproductive age is given.
Formation of Artifactual Ammonia in Blood by Action of Alkali
Authors: Reinhold John G , Chung Charles C
Published: January 2020

Data are presented that demonstrate that ammonia is formed in the course of the analysis of blood samples. The formation has been traced to the decomposition of protein by the action of alkali.

The pH established during the diffusion process was of critical importance in the measurements. A technic is described by which ammonia is displaced from blood by a sodium borate buffer at a pH that avoids spontaneous production of ammonia from blood protein. The Seligson-Seligson microdiffusion apparatus is used. Instructions are given for the collection of blood samples and the preparation of reagents and standard solutions.
Bubble Mixing Device for Blood Sampling by Automatic Analysis
Authors: Naumann Hans N , Olsen Abbie M , Young Joseph M
Published: January 2020

A mixing device is described for resuspending sedimented blood cells in specimens being processed by automatic chemical analysis. Method, which requires use of anticoagulant, may be used with any unstable suspension or emulsion processed automatically.
Evaluation of a Reconstituted Dried Serum as a Clinical Chemistry Standard in the Abnormal Range
Authors: Klein Bernard , Weissman Milton
Published: January 2020

A lyophilized serum chemistry reference standard containing constituents in the "abnormal" range has been evaluated for use as a proficiency standard. The findings indicate that it is a satisfactory material for such use and as a reference standard, provided that it is used in accordance with the manufacturer's directions. Interferences contributing to inaccurate results in the analysis of bilirubin, cholesterol, and uric acid are indicated and discussed. It is recommended that the standard be used for the preparation of calibration curves for bilirubin and uric acid.
Measurement of Serum Lactic Dehydrogenase
Authors: Ells H Alan
Published: January 2020

A colorimetric method is described for the measurement of serum lactic dehydrogenase (LDH) activity. The method employs phenazine methosulfate to mediate electron transfer between reduced diphosphopyridine nucleotide and 2,6-dichloroindophenol, and allows continuous measurement of the reaction rate in the direction lactate to pyruvate. The LDH of a number of normal and pathologic sera was measured by the present method and by the ultraviolet spectrophotometric method. Agreement between the two methods is good.
Amino-aciduria and Mental Retardation
Authors: Zellweger Hans
Published: January 2020

The different biochemical disturbances leading to or associated with mental retardation are reviewed. Clinical symptomatology, pathogenesis, and possible treatment of some forms of mental retardation and amino-aciduria are discussed.
Studies on Hepatic Sulfobromophthalein Removal During Infusion
Authors: Pagliardi E , Giangrandi E
Published: January 2020

Experiments were performed with the infusion of sulfobromophthalein (BSP) for brief periods (15 min.) in man, following an initial massive dose of dye at the beginning of the experiment. Infusion was such as to ensure a continuous increase in the plasma BSP level. In these conditions, BSP removal due to the storage capacity of the liver was studied. The rate of removal was found to depend on the concentration gradients of BSP/protein in the serum and in the liver cell. It was also shown that the values for the hepatic removal determined according to this method are correlated in a highly significant manner with the values for the BSP clearance.
New Cholesterol Reagent
Authors: Zak B , Epstein E
Published: January 2020

A study was carried out on a new cholesterol reagent which was reported to be a saturated solution of ferrous sulfate in glacial acetic acid. This solution was shown to be unstable and it is suggested that the reactive state of the metal involved is that of the more stable trivalent ferric iron.
Paper Electrophoresis of Native Gastric Juice after Concentration by Dialysis against Carbowax 6000
Authors: Ishimori Akira , Jerzy Glass George B
Published: January 2020

A method is presented for the concentration of native gastric juice by dialysis against a 30% solution of Carbowax 6000 in distilled water, prior to paper electrophoresis. Detailed descriptions of the dialysis procedure and subsequent vertical paper electrophoresis are given. The data show that the dialysis procedure is comparable to the lyophilization technic and has the advantage of faster processing, which makes the method applicable to routine clinical use in many diagnostic applications.
Identification of Cholesterol in Fluid from an Intracranial Cyst by X-Ray Diffraction
Authors: Parsons Jonathan , Bartone John R
Published: January 2020

The use of X-ray diffraction to identify crystals from the fluid obtained from a brain tap is illustrated. The procedure for making this type of analysis is described and a very brief description of X-ray diffraction process given. Photographs of the powder diffraction patterns are included, as well as a table giving the interplanar distances and relative intensities corresponding to the pattern for cholesterol.
Critical Evaluation of a New Ultramicro System for Routine Clinical Chemistry Procedures
Authors: O'Brien Donough , Ibbott Frank , Pinfield Ann
Published: January 2020

A critical appraisal is presented of 11 clinical chemical methods presently available with the Beckman/Spinco Ultramicro Analytical System. After certain modifications, the suggested technics, with the exception of that for serum bicarbonate estimation, offer acceptable standards of accuracy for clinical work.
Determination of the pH of Hemolyzed Packed Red Cells from Arterial Blood
Authors: Purcell May K , Still Gertrude M , Rodman Theodore , Close Henry P
Published: January 2020

A technic is described for the determination of the in vivo pH of red blood cell hemolysates. The mean arterial red cell pH of 20 normal subjects was 7.19 with a range of 7.15 to 7.22. The fiducial probability at the 0.95 level is 7.13 to 7.25. The mean difference in pH between plasma and cells was 0.21, with a range of 0.15 to 0.23.

It is suggested that changes in pH of erythrocytes may reflect changes in other less accessible cells of the body and that the determination may be a useful research and clinical procedure in the study of metabolic and respiratory derangements.
An Evaluation of Four Methods of Measuring Urinary Creatinine
Authors: Cooper James Martin , Biggs H G
Published: January 2020

Four different methods were evaluated for the determination of the creatinine content of a series of 24-hour urine samples. The results indicate that the methods of Folin, Hare, and Van Pilsum give essentially the same values. The precision of the method of Sullivan and Irreverre was extremely poor and the values obtained were 2-8 times higher than those obtained by the other technics.

The compound, 1,4-naphthoquinone, used in the procedure of Sullivan and Irreverre, was synthesized and compared with a commercial sample. Data concerning 1,4-naphthoquinone-2-potassium sulfonate is given to clarify its identity.
Optimal Conditions for the Enzymatic Determination of L-Lactic Acid
Authors: Olson G F
Published: January 2020

A simple enzymatic method for the determination of lactic acid with muscle lactic dehydrogenase is described. L(+) Lactate in amounts from 0.04 µM to 0.4 µM can be directly measured by following the formation of reduced diphosphopyridine nucleotide at 340 mµ.

The effect of varying the concentrations of reactants in the test system was studied, and the optimal concentrations for stoichiometric conversion of lactate to pyruvate were determined. When lactic acid concentrations in plasma, liver, and heart muscle were determined by both enzymatic and chemical methods, identical results were obtained. The advantages of the present enzymatic procedure over chemical methods are discussed.
Lactic Dehydrogenase in the Serum of Newborn Infants with Jaundice
Authors: McCoord Augusta B , Jameson Dorothy H , Daugherty Viola R
Published: January 2020

The concentration of LDH in the serum of normal newborn infants tends to be greater than in that of normal older children and adults. The concentration of LDH in the serum of infants suffering from erythroblastosis fetalis is very variable and may be increased much above that of normal infants. A considerable number of babies with erythroblastosis fetalis have higher concentrations of LDH and lower concentrations of indirect-reacting bilirubin in their serum than do babies with physiologic jaundice (hyperbilirubinemia). However, among the infants studied, there is no consistent correlation between the concentration of serum LDH and that of indirect-reacting bilirubin. In infants being treated by exchange transfusion, the rise and fall of serum LDH and bilirubin tend to parallel each other.
Serum Amylase Determination by Somogyi's Amyloclastic Method with Use of a Photometric End-Point
Authors: Reif Arnold E , Nabseth Donald C
Published: January 2020

Somogyi's amyloclastic amylase assay has been modified by substitution of a spectrophotometric end point for visual observation, thereby increasing precision without changing the Somogyi assay units.

A method of estimating starch concentration from the intensity of the starchiodine color reaction is described; absorbance is directly proportional to starch concentration.

Somogyi's finding that corn starch is the substrate showing least variation inability to be degraded by amylase has been confirmed; a rapid method of standardizing the substrate is described.

High amylase activities obtained using the amyloclastic method with sera containing lysed red cells are artifacts resulting from the interference of hemoglobin with the starch-iodine color reaction; the extent of the interference has been delineated, and means of avoiding it are described.
Micro Immunochemical Method for Estimating High- and Low-Density Lipoproteins
Authors: Searcy R L , Carroll V P , Carlucci J S , Bergquist L M
Published: January 2020

A rapid technic is proposed for immunochemically measuring total, high- and low-density lipoprotein cholesterol as well as total low-density lipoprotein precipitates in small quantities of human serum. Lipoprotein cholesterol values obtained by the method are reproducible and correlate well with those yielded by paper electrophoresis. The immunochemical procedure has been used to assess serum lipid fractions in 10 patients during a short-term course of sodium dextro-thyroxine therapy.
1960 Survey of Clinical Chemistry Procedures used by Members of the American Association of Clinical Chemists
Authors: Rice Eugene W , Grogan Betty S
Published: January 2020

The results of the survey of the analytical procedures currently used in the clinical laboratories of members of the American Association of Clinical Chemists for the routine determination of 14 selected blood constituents are presented. The data are analyzed critically and discussed in relation to the question of standardization of bioanalytical procedures.
Beta Radiation Self Absorption of Precipitates Collected on Filter Paper
Authors: Gottschalk Raymond G , Hoch Hans , Stidworthy George H
Published: January 2020

Different yields of precipitate and different types of self absorption curves were obtained when radioactive sulfur was precipitated as BaSO4 in the presence and in the absence of salt. An equation was derived for expressing the self absorption of precipitates collected on filter paper which takes into account the yield of precipitate and the partial penetration of the precipitate into the filter paper. From the computed estimates of the parameters, it was concluded that the precipitate obtained in the absence of salt penetrates into the filter paper. This conclusion was supported by microscopic observations.

The Denis method of oxidation followed by barium precipitation and filtration is well suited for the determination of total and isotopic sulfur because of complete recovery and lack of penetration of the precipitate into the filter paper. The count rates of radiosulfur treated by this method fit the usual equation reflecting an exponential absorption of beta radiation better than empirical linear relationships. A filtration apparatus is described which permits the determination of the radioactivity of a precipitate without removing the filter paper from its support.
Gel Electrophoresis
Authors: Raymond Samuel , Nakamichi Masumi
Published: January 2020

Gel electrophoresis is discussed and it is shown that this medium is still in the developmental stage for the resolution of serum proteins. It is the procedure of choice for the analysis of hemoglobins.
Electrometric Titration of Copper and Zinc in Biologic Material
Authors: Johnson Nathaniel C
Published: January 2020

Copper and zinc are determined in biologic material by titration with tetraethylenepentamine (Tetren) at selected pH levels by means of a dual polarized mercury electrode. The procedure is rapid and eliminates wet ashing of organic material.
Serum Lipase Determination with an Olive Oil Substrate Using a Three-Hour Incubation Period
Authors: MacDonald Roderick P , LeFave Royal O
Published: January 2020

The effect of various emulsifying agents, pH, buffers, and accelerators on the Cherry-Crandall procedure for determining serum lipase was studied. A method is proposed which uses a 3-hour incubation period. Olive oil emulsified with 7% acacia is the substrate. This is buffered with tris buffer, pH 8.0; magnesium acetate and EDTA are added as accelerators. Other conditions which result in an increased rate of hydrolysis are discussed.
An o-Toluidine Method for Body-Fluid Glucose Determination
Authors: Dubowski Kurt M
Published: January 2020

Since publication of the above paper, we have found that a procedure similar to the one described for determination of aldosaccharides in body fluids using o-toluidine in glacial acetic acid solution was described by Eric Hultman in Nature183, 108 (1959). A modification of Hultman's procedure has recently been described by A. Hyvärinen and E. A. Nikkilä in Clin. Chim. Acta7, 140 (1962).

The omission of reference to Dr. Hultman's paper was entirely unintentional. Our own procedure was, of course, derived entirely experimentally, based upon Dr. O. M. Forsell's suggestion to us of Mar. 13, 1960, that we should consider the use of o-toluidine as a glucose reagent; and this suggestion is properly credited in the paper as a personal communication. The papers by Hultman and by Hyvärinen and Nikkilä nicely confirm some of the significant experimental details and results of our procedure; but obviously the Hultman paper has priority with respect to this principle.
X-Ray Spectrometry in the Clinical Laboratory
Authors: Natelson Samuel , Sheid Bertrum , Leighton Donald R
Published: January 2020

A procedure is described for estimating the bromide content of human serum from individuals not receiving bromide medication. In the procedure, the serum is ashed and dissolved in hydrochloric acid. The solution is dehydrated with the calculated amount of acetic anhydride and the precipitated sodium chloride is washed with additional glacial acetic acid to remove the bromides. The sodium chloride is removed by centrifugation and the bromides recovered by evaporation of the acetic acid. The residue is dissolved in methanol and transferred to filter paper for assay in the X-ray spectrometer. The procedure, with the omission of ashing, is applicable to sea water. When it was applied to sea water, strontium as well as bromide could be visualized on the recorder of the instrument and assayed.

Normal human serum was found to contain a mean level of 252 µg. bromide per 100ml., with a range (2σ) of ± 42 µg./100 ml.
Serum Protein Determination by Automatic Recording Refractometry
Authors: Marsh W H , Fingerhut B
Published: January 2020

The results of a preliminary study of the feasibility of using recording differential refractometry for total serum protein determination indicate that the method has some merit.
Blood Oxygen Determination by Gas Chromatography
Authors: Chambliss K Wayne , Nouse Don C
Published: January 2020

One hundred blood specimens have been analyzed for blood oxygen content simultaneously by the Van Slyke gasometric technic and gas chromatographic technic. The two technics agree within ±0.83 Vol.%.

The gas chromatography instrument must be standardized by comparing its results with another blood oxygen procedure such as the Van Slyke technic.

Suggestions are made for the improvement of the gas chromatography equipment.
Standard of Purity for Cholesterol
Authors: Radin Nathan , Gramza Adalbert L
Published: January 2020

Three recrystallization technics were used to fractionate five commercial cholesterol products and one artificial mixture. One technic involved the recrystallization of cholesterol from absolute ethyl alcohol, the second technic involved the recrystallization of cholesterol from glacial acetic acid, and the third technic used the dibromide derivative method. The molar absorptivities for the various crystal batches were in the range of 1610 to 1750 L. mole-1 cm.-1 at 620 mµ with a modified Liebermann-Burchard procedure. The molar absorptivities were in the range of 9,800 to 11,500 L. mole-1 cm.-1 at 560 mµ with a modified sulfuric acid-iron method. The original products and the ethyl alcohol recrystallized products showed molar absorptivities at the lower limits of the ranges, while the glacial acetic acid and dibromide derivative recrystallized cholesterol showed molar absorptivities at the higher limits of the ranges. Absorption peaks at 235 mµ for methyl alcohol solutions of the cholesterol preparations were used to estimate cholesterol impurities on the basis of 7-keto cholesterol acetate absorption values. The decrease of absorption in the ultraviolet spectral region established that impurities were removed from the cholesterol preparations studied.
Simple Open Fusion for an Iodine Screen Test
Authors: Baginski Eugene S , Zak Bennie
Published: January 2020

A procedure is described for the screening of serum samples for contamination with iodine. It is extremely rapid, obviates any cross-contamination problem, and is not influenced by the organic compounds of raw serum or filtrates. Studies indicate that the open-combustion technic is a reliable screening system for the handling of large numbers of samples.
A Mercurimetric Chloride Determination Suitable for Icteric Sera
Authors: Fingerhut B , Marsh W H
Published: January 2020

A modification of the direct mercurimetric determination of serum chloride suitable for icteric sera is presented. The method is simple, rapid, and accurate. No deproteinization of the sample is required. The results agree well with the standard protein-free filtrate procedure of Schales and Schales.
Changes in the Serum Protein Levels During Wound Tissue Regeneration
Authors: DiLallo Lilita , Haley Harold B , Williamson Martin B
Published: January 2020

The effect of wounding and formation of regenerating wound tissue on the level of the serum proteins was studied in rats on a protein-free diet. It was found that the level of the globulin component having the third greatest electrophoretic mobility, probably part of the α2-globulin fraction, rose about 60% within 3 days after wounding and did not begin to return to normal until about 10 days later. Concomitantly, the level of the globulin with least mobility, presumably the -globulin component, decreased about 35% and also began to return to normal within 2 weeks after wounding. Varying the rate of healing, by the addition of protein or methionine to the diet, had no effect on the changes in the serum globulin levels. The newly formed α2-globulins were shown to be distinct from fetuin.
The Fate of Large Doses of Creatine Injected Intraperitoneally into Normal Rats
Authors: Van Pilsum John F , Warhol Richard M
Published: January 2020

Four young adult male rats were given an intraperitoneal injection of 227 mg. creatine and their urines collected for 48 hr. The creatine and creatinine in the carcass and urine of these 4 rats and in those of 4 control rats were determined.

Eighty-nine per cent of the injected dose was recovered-83% in the urine and 6% in the carcass. The data are interpreted to indicate that there was no significant destruction of creatine under these experimental conditions in the normal rat.
Direct Determination of Calcium in Icteric Serum
Authors: Fingerhut B , Miller H
Published: January 2020

A rapid method suitable for the direct titrimetric determination of calcium in icteric sera is presented. The major portion of serum chromogens are oxidized to colorless products by either a mixture of hydrogen peroxide and potassium ferricyanide or by sodium hypochlorite. Ethylenediamine tetraacetic acid (EDTA) is the titrant used and either calcein or Cal-Red is suitable as the specific calcium indicator. Results compare favorably with those obtained by the method of Clark and Collip.
A Spectrophotometric Method for Measuring Serum Trypsin Inhibitor Capacity
Authors: Homer George M , Katchman Bernard J , Zipf Robert E
Published: January 2020

The spectrophotometric method of Schwert and Takenaka (11) for the assay of trypsin esterolytic activity has been modified for the measurement of the trypsin inhibitor capacity of serum. An average value of 0.99 mg. of trypsin inhibited per milliliter of serum (3 S.D. = ±0.30) was determined for 50 control subjects. Patient serum assay values determined with this method have been found similar to those determined with the modified Kunitz method using l131-labeled casein as the substrate-in the normal range for a variety of pathologic conditions and in the elevated range for abnormalities of the pancreas and generalized cancer conditions. From the standpoints of accuracy, simplicity, and speed this technic is believed to be an improvement over previous methods for the measurement of this serum variable.
Modification of the Fluorescence Attachment for the Beckman Model DU Spectrophotometer
Authors: Rockenmacher Morris , Farr Andrew F
Published: January 2020

Details are given for the modification of the fluorescence attachment for the Beckman DU instrument so that all filters are easily changed. The versatility of the instrument is improved as the attachment does not have to be removed when the instrument is used as a spectrophotometer.
A Modified Ninhydrin Colorimetric Method for the Determination of Plasma Alpha-Amino Nitrogen
Authors: Fisher Lillian J , Bunting Sylvia L , Rosenberg Leon E
Published: January 2020

The present report describes the development of and results with a modified ninhydrin colorimetric method for the determination of free plasma -amino nitrogen. Precipitation of the plasma proteins with a hydrochloric acid-sodium tungstate reagent, filtration of the deproteinized filtrate through glass wool plugs, and reduction of the pH of the reaction resulted in improved reproducibility, lower water blank readings, and lower plasma -amino nitrogen concentrations which agreed closely with values obtained using other standard technics. The stoichiometry of the modified reaction and recovery of standard amino acid solutions were investigated and found to be satisfactory. A comparative study with the ninhydringasometric technic showed that the modified colorimetric procedure described herein yielded values in very close agreement with the more laborious manometric determination. Fasting venous plasma samples obtained from 21 normal volunteers yielded a mean plasma concentration of 3.85 mg./100 ml. The report concludes from these observations that the modified colorimetric procedure provides an accurate, simple, and rapid estimation of the total free amino acid content of human blood plasma.
In Vitro Stabilization of Blood Glucose with Water
Authors: Meites Samuel , Bohman Nancy
Published: January 2020

The loss in glucose that shed blood undergoes on standing may be effectively inhibited for 2 hr., prior to protein precipitation, by a dilution with water of 1:80 (v/v). The inhibitory effect of water is independent of glucose concentration and temperature (up to and including room temperature). Incorporation of the dilution into the glucose oxidase method of Washko and Rice (4) makes the method particularly appropriate for the newborn.
A Quantitative Method of Determining Urinary Phenols
Authors: Barness Lewis A , Mellman William J , Tedesco Thomas , Young Diana G , Nocho Robert
Published: January 2020

A quantitative method for the determination of urinary phenols is described. Data obtained in 20 children by this method are similar to averages in adults obtained by others. This is exceeded by the excretion of a phenylketonuric infant when placed on excessive intakes of phenylalanine.
Differential Fluorometry in Catecholamine Determination: A Simplified Method of Calculation
Authors: Brunjes Shannon , Wybenga Donald
Published: January 2020

A method for calculating the results of differential fluorometry in the determination of epinephrine and norepinephrine is described. A form which outlines the calculations in steps is illustrated. This simplified method is applicable to differential fluorometry and other procedures which involve solving two equations simultaneously.
The Accurate Gasometric Determination of the Oxygen-Hemoglobin Equilibrium in Dilute Solutions of Sheep Hemoglobin
Authors: Roughton F JW
Published: January 2020

Apparatus and technique are described for the accurate gasometric macrodetermination of the oxygen-hemoglobin equilibrium in dilute solutions containing around 0.15 gm. Hb/100 ml., equivalent to blood diluted 100:1.

At the bottom of the equilibrium curve, i.e., in the range 0-2% Hb02, the method is accurate to ± 0.05% HbO2. Over the main part of the curve the mean accuracy is ± 0.5% Hb02. From such data, together with indirect kinetic information as to the character of the extreme top of the equilibrium curve, it has been possible, in the case of dilute sheep Hb solutions, to compute all four constants in Adair's general intermediate compound equation for the equilibrium between oxygen and hemoglobin.

Comparison of the results at pH 7.1 and 9.1 suggests that the first two oxygen molecules combine independently at both pH's. Interaction sets in at the third and more markedly at the fourth stage, but there are detailed differences in the degrees of interaction at these last two stages at the two pH's.

It is hoped that these equilibrium data in dilute sheep Hb solution will be of service in interpreting kinetic experiments on the rates of the reactions of oxygen and hemoglobin, which so far can only be carried out in dilute solutions of the latter.
A Mathematical Treatment of the Blood Dissociation Curve for Oxygen
Authors: Margaria Rodolfo
Published: January 2020

A quantitative description of Bohr's effect can be made from the oxygen dissociation curves of hemoglobin at different pHs, and the dissociation constants of the 02-linked acidic group of Hb (KR) and Hb02 (Ko) have been calculated as, respectively, 1.29 1O-8 and 3.42 10-7 at37°.

On the assumption that the oxygenation of hemoglobin takes place in four successive steps, the constant for each equilibrium can easily be calculated, and the values given. It appears that the oxygenation takes place with the same affinity for the first three steps, while the affinity for the fourth oxygenation is 125 times greater.

On the basis of these results a simplification of Adair's formula is given, containing only two constants, one (K) being representative of the affinity of the oxygen for the first three hemes, and the other (in)being the increase of affinity for the fourth oxygenation. This formula seems to fit most data in the literature of hemoglobin solutions and of blood in vivo and in vitro.

The physiological effects and the functional importance of the increased affinity for the fourth oxygenation are described, and the possibility that disturbances of the Hb oxygenation process may be due to the lack of this process is considered.
A Rapid Procedure for Catalase Determination in Blood and Tissue Samples with the Van Slyke Manometric Apparatus
Authors: Kirk John Esben
Published: January 2020

A precise and rapid gasometric procedure is described for catalase determination in blood and tissue samples. The enzyme activity assay is performed with the Van Slyke manometric apparatus. In the developed technicw, a 45-sec. reaction period is used, and a large liquid-gas interphase is provided with the purpose of preventing the oxygen diffusion from becoming a rate-limiting factor. Under the devised methodological conditions, the rate of oxygen evolution closely follows a parabolic curve which permits the calculation of the initial activity velocity of the enzyme. The oxygen evolvement is directly proportional to the quantity of catalase present in the analyzed sample. Less than 4 min. are required for each catalase measurement.
A Procedure for Quantitative Determination of the Diaphorase Activity of Connective Tissue
Authors: Kirk John Esben
Published: January 2020

A quantitative procedure is described in which the diaphorase activity of samples with a high connective-tissue content is measured visually through determination of the decolorization time of 2,6-dichlorophenolindophenol in the presence of DPNH and NaCN. The decolorization time values are directly converted to standard Mahler diaphorase units.
Artificial intelligence with multi-functional machine learning platform development for better healthcare and precision medicine
Authors: Ahmed Zeeshan , Mohamed Khalid , Zeeshan Saman , Dong XinQi
Published: January 2020

Precision medicine is one of the recent and powerful developments in medical care, which has the potential to improve the traditional symptom-driven practice of medicine, allowing earlier interventions using advanced diagnostics and tailoring better and economically personalized treatments. Identifying the best pathway to personalized and population medicine involves the ability to analyze comprehensive patient information together with broader aspects to monitor and distinguish between sick and relatively healthy people, which will lead to a better understanding of biological indicators that can signal shifts in health. While the complexities of disease at the individual level have made it difficult to utilize healthcare information in clinical decision-making, some of the existing constraints have been greatly minimized by technological advancements. To implement effective precision medicine with enhanced ability to positively impact patient outcomes and provide real-time decision support, it is important to harness the power of electronic health records by integrating disparate data sources and discovering patient-specific patterns of disease progression. Useful analytic tools, technologies, databases, and approaches are required to augment networking and interoperability of clinical, laboratory and public health systems, as well as addressing ethical and social issues related to the privacy and protection of healthcare data with effective balance. Developing multifunctional machine learning platforms for clinical data extraction, aggregation, management and analysis can support clinicians by efficiently stratifying subjects to understand specific scenarios and optimize decision-making. Implementation of artificial intelligence in healthcare is a compelling vision that has the potential in leading to the significant improvements for achieving the goals of providing real-time, better personalized and population medicine at lower costs. In this study, we focused on analyzing and discussing various published artificial intelligence and machine learning solutions, approaches and perspectives, aiming to advance academic solutions in paving the way for a new data-centric era of discovery in healthcare.
The MB score: a new risk stratification index to predict the need for advanced tools in lead extraction procedures
Authors: Bontempi Luca , Curnis Antonio , Della Bella Paolo , Cerini Manuel , Radinovic Andrea , Inama Lorenza , Melillo Francesco , Salghetti Francesca , Marzi Alessandra , Gargaro Alessio , Giacopelli Daniele , Mazzone Patrizio
Published: January 2020

Aims

A validated risk stratification schema for transvenous lead extraction (TLE) could improve the management of these procedures. We aimed to derive and validate a scoring system to efficiently predict the need for advanced tools to achieve TLE success.

Methods and results

Between November 2013 and March 2018, 1960 leads were extracted in 973 consecutive TLE procedures in two national referral sites using a stepwise approach. A procedure was defined as advanced extraction if required the use of powered sheaths and/or snares. The study population was a posteriori 1:1 randomized in derivation and validation cohorts. In the derivation cohort, presence of more than two targeted leads (odds ratio [OR] 1.76, P = 0.049), 3-year-old (OR 3.04, P = 0.001), 5-year-old (OR 3.48, P < 0.001), 10-year-old (OR 3.58, P = 0.008) oldest lead, implantable cardioverter-defibrillator (OR 3.84, P < 0.001), and passive fixation lead (OR 1.91, P = 0.032) were selected by a stepwise procedure and constituted the MB score showing a C-statistics of 0.82. In the validation group, the MB score was significantly associated with the risk of advanced extraction (OR 2.40, 95% confidence interval 2.02-2.86, P < 0.001) and showed an increase in event rate with increasing score. A low value (threshold = 1) ensured 100% sensibility and 100% negative predictive value, while a high value (threshold = 5) allowed a specificity of 92.8% and a positive predictive value of 91.9%.

Conclusion

In this study, we developed and tested a simple point-based scoring system able to efficiently identify patients at low and high risk of needing advanced tools during TLE procedures.
A combined subunit vaccine comprising BP26, Omp25 and L7/L12 against brucellosis
Authors: Gupta Sonal , Singh Damini , Gupta Manish , Bhatnagar Rakesh
Published: January 2020

The current vaccines against brucellosis, namely Brucella abortus strains 19 and RB51, prevent infection in animals but pose potential risks like virulence and attenuation reversal. In this milieu, although subunit vaccination using a single potent immunogen of B. abortus, e.g. BP26 or Omp25 or L7/L12 etc., appears as a safer alternative, nonetheless it confers inadequate protection against the zoonosis compared to attenuated vaccines. Hence, we have investigated the prophylactic potential of a combined subunit vaccine (CSV) comprising the BP26, Omp25 and L7/L12 antigens of B. abortus, in mice model. Sera obtained from CSV immunized mice groups showed heightened IgG titers against all the three components and exhibited specificity upon immunoblotting, reiterating their authenticity. Further, the IgG1/IgG2a ratio obtained against each antigen revealed a predominant Th2 immune response in CSV immunized mice group. However, on assessing the levels of Th1-dependent (IFN-γ and TNF-α) and Th2-dependent (IL-4 and IL-10) cytokines in different formulations, prominent IFN-γ levels were elicited in CSV immunized mice. Further, upon infection with virulent B. abortus 544, the combined subunit vaccinated mice displayed superior degree of protection (Log10 reduction) than the individual vaccines; however, B. abortus S19 showed the highest protection. Altogether, this study suggests that co-immunization of three B. abortus immunogens as a CSV complements and triggers a mixed Th1/Th2 immune response leading to superior degree of protection against pathogenic B. abortus 544 infection.
Creation of the Person-Centered Wellness Home in Older Adults
Authors: Mielenz Thelma J , Tracy Melissa , Jia Haomiao , Durbin Laura L , Allegrante John P , Arniella Guedy , Sorensen Julie A
Published: January 2020

Background and Objectives

Extending the Patient-Centered Medical Home (PCMH) model into the community may address the poor linkage between medical clinics and underserved communities. Our first of three objectives was to determine if peer leaders and wellness coaches can be the relationship center of wellness care. We evaluated the Self-management Resource Center Small Group Programs (SMRCSGP), plus wellness coaching, as a booster intervention in older adults with chronic diseases. Second, we evaluated the role of personal health records (PHR) prototype as the linkage between the clinic and community. Using input from these two objectives, we lay the groundwork for the Person-centered Wellness Home (PCWH).

Research Design and Methods

Participants enrolled from five South Bronx New York City Housing Authority communities. We conducted a pragmatic, randomized controlled trial using two arms (n = 121): (1) SMRCSGP and (2) SMRCSGP plus wellness coaching initiated as a booster after SMRCSGP completion. Adjusted individual growth models compared the slope differences for outcomes. We conducted a social networking analysis on the ties between wellness coaches and participants. PCMH-certified physicians completed in-depth interviews on the PHR prototype. An adaptation from the consensus-workshop model summarized the priority PCWH items.

Results

There was an improvement in self-reported physical functioning (2.0 T-score units higher, p = .03) by the wellness coaching group, but the groups did not differ on physical activity. From the social networking analysis, connections were stable over time with wellness-coaches and participants. The Consensus Conference identified eight major components of the PCWH.

Discussion and Implications

Wellness coaching post-SMRCSGP was a booster to physical function, an upstream outcome for physical activity. During the Consensus-Conference, community-based prevention marketing and personal navigators for connecting to a PCMH emerged as novel components. This supports future work in training community health workers as peer leaders to provide evidence-based programs and other PCWH components.
3D revelation of phenotypic variation, evolutionary allometry, and ancestral states of corolla shape: a case study of clade Corytholoma (subtribe Ligeriinae, family Gesneriaceae)
Authors: Hsu Hao-Chun , Chou Wen-Chieh , Kuo Yan-Fu
Published: January 2020

Background

Quantification of corolla shape variations helps biologists to investigate plant diversity and evolution. 3D images capture the genuine structure and provide comprehensive spatial information.

Results

This study applied X-ray micro-computed tomography (μCT) to acquire 3D structures of the corollas of clade Corytholoma and extracted a set of 415 3D landmarks from each specimen. By applying the geometric morphometrics (GM) to the landmarks, the first 4 principal components (PCs) in the 3D shape and 3D form analyses, respectively, accounted for 87.86% and 96.34% of the total variance. The centroid sizes of the corollas only accounted for 5.46% of the corolla shape variation, suggesting that the evolutionary allometry was weak. The 4 morphological traits corresponding to the 4 shape PCs were defined as tube curvature, lobe area, tube dilation, and lobe recurvation. Tube curvature and tube dilation were strongly associated with the pollination type and contained phylogenetic signals in clade Corytholoma. The landmarks were further used to reconstruct corolla shapes at the ancestral states.

Conclusions

With the integration of μCT imaging into GM, the proposed approach boosted the precision in quantifying corolla traits and improved the understanding of the morphological traits corresponding to the pollination type, impact of size on shape variation, and evolution of corolla shape in clade Corytholoma.