bluuebunny/crossref_metadata_2025_split huggingface dataset:
A fluorescence polarization immunoassay evaluated for quantifying astromicin, a new aminoglycoside antibiotic.
Authors: Uematsu T , Sato R , Mizuno A , Nishimoto M , Nagashima S , Nakashima M 
Published: January 2020

Abstract
We evaluated a fluorescence polarization immunoassay (FPIA) procedure for measuring astromicin, a new aminoglycoside antibiotic. The calibration curve can be stored for at least 32 days without loss of accuracy. There were no interferences from hemoglobin (up to 4000 mg/L) or bilirubin (up to 200 mg/L), nor were there any cross-reactivities with amikacin, gentamicin, or tobramycin. Within-run precision (CV) for 20 replicates, each at concentrations of 5, 15, and 25 mg/L, was 1.25-2.11%. Between-run precision for these same concentrations, measured on five occasions, was 2.13-2.74%. Linear-regression analyses of data by FPIA (y) and HPLC (x) for plasma obtained from six healthy male volunteers who were given 200 mg of astromicin by 30-min intravenous infusion and for sera prepared by adding arbitrary amounts of astromicin showed highly significant correlations: r = 0.996 (n = 66), y = 0.96x - 0.48 mg/L and r = 0.981 (n = 59), y = 0.96x - 0.25 mg/L, respectively. This assay offers a rapid, efficient, and accurate system for therapeutic monitoring of astromicin in blood.
Glycated lysine increases in serum samples stored at -20 degrees C.
Authors: Schäffer L 
Published: January 2020

Abstract
The glycated lysine in serum protein was determined by HPLC measurement of furosine in hydrolyzed serum, with synthetic N alpha-Boc-N epsilon-(1-deoxy-D-fructosyl)-L-lysine as the standard. The glycated lysine value increased with time of storage when the serum was kept at -20 degrees C, possibly because of an ongoing reaction between glucose and the epsilon-amino groups of lysine in the frozen serum. The problem was eliminated by using storage at -70 degrees C or by acidifying the serum before storing it at -20 degrees C.
Fluorimetry of selenium in body fluids after digestion with nitric acid, magnesium nitrate hexahydrate, and hydrochloric acid.
Authors: Pettersson J , Hansson L , Ornemark U , Olin A 
Published: January 2020

Abstract
A digestion procedure involving nitric acid, magnesium nitrate hexahydrate, and hydrochloric acid suffices for selenium determinations in whole blood, serum, and urine by molecular fluorescence spectrometry. To test the accuracy of the method we compared the results with those from hydride-generation atomic absorption spectrometry, and we also analyzed reference materials.
Pancreatic amylase measured in serum by use of a monoclonal antibody immunochemically immobilized to a solid phase.
Authors: Mifflin T E , Hamilton M , Hubbard E , Kline M J , Bruns D E 
Published: January 2020

Abstract
We studied a method for measuring the pancreatic isoenzyme of amylase (EC 3.2.1.1) by use of a mouse monoclonal antibody against human salivary-type amylase (Clin Chem 1985;31:1283) coupled indirectly to particles of polyvinylidene fluoride via polyclonal goat anti-mouse immunoglobulin. These particles, in 200 microL of a suspension, could remove salivary amylase (activity 2200 U/L) from an equal volume of serum in 5 min. Measurement of amylase activity in the supernatant fluids from treated sera thus provided an assay of pancreatic amylase. Precision studies at three activity concentrations yielded within-run CVs of 1.6% to 1.7% (n = 25) and total CVs of 2.2% to 5.1% (20 days). Salivary amylase added to each of 10 sera was completely (99.8%, SD 1.6%) removed. The new method (y) showed the following regression statistics when compared with an electrophoretic method (x): slope = 0.989 (SD 0.019), intercept = -0.220% (SD 1.48%), SEE 4.0%, n = 51. Similar respective regression values were found for urine samples: slope = 0.934 (SD 0.053), intercept = 2.3 U/L (SD 3.2), SEE 8.4 U/L, n = 26. The following respective values were found when the new method (y) was compared with the previously described immunoprecipitation assay (x): slope = 1.02 (SD 0.02), intercept = 2.2% (SD 1.4%), SEE 3.3%, n = 23 sera. Reference intervals for pancreatic amylase activity in serum were established for three different substrates: maltotetraose, maltopentaose, and p-nitrophenylheptaoside.
Clinical and analytical evaluation of different methods for measurement of creatine kinase isoenzyme MB.
Authors: Schwartz J G , Brown R W , McMahan C A , Gage C L , Herber S A 
Published: January 2020

Abstract
We evaluated the clinical and analytical performance of the new immunochemiluminometric assay (ICMA; Ciba Corning) for measurement of creatine kinase isoenzyme MB (CK-MB), and compared it with three other methods: immunoradiometric assay (IRMA; International Immunoassay Labs); immunoinhibition assay (Seradyn); and an immunoinhibition/column method (Du Pont). Intra-test precision for all kits was good. We evaluated 32 patients' samples by all four methodologies. Only one of the four methods (aca, Du Pont) showed evidence of linearity. Efficiency in the diagnosis of myocardial injury in our study ranged from 53% (Seradyn) to 96% (Du Pont). We evaluated serial specimens from 20 separate patients by the IRMA and the ICMA to determine whether myocardial injury could be diagnosed earlier by the ICMA. In patients with acute myocardial infarction, the ICMA displayed positive values earlier and longer than the IRMA, suggesting that the ICMA is suited for screening for myocardial damage in hospitalized patients.
Effects of various serum proteins on quantification of fructosamine.
Authors: Rodriguez-Segade S , Lojo S , Camiña M F , Paz J M , Del Río R 
Published: January 2020

Abstract
We determined fructosamine concentrations with the CentrifiChem 600 centrifugal analyzer and the Hitachi 737 discrete analyzer. Reference intervals agreed with the most recently published results, and values in fasting patients were significantly correlated with glycated hemoglobin, plasma glucose, albumin, beta- and gamma-globulins, IgG, IgA, IgM, and total protein. Partial correlation analysis showed that only fructosamine and IgA were dependently related. In a group of nondiabetic patients with pathological values for IgA concentrations, 79.4% had pathological values for fructosamine. These results throw doubt on the clinical value of fructosamine determinations if serum IgA is not taken into account.
Differences between values for plasma and serum in tests performed in the Ektachem 700 XR Analyzer, and evaluation of "plasma separator tubes (PST)".
Authors: Doumas B T , Hause L L , Simuncak D M , Breitenfeld D 
Published: January 2020

Abstract
We measured 25 analytes in plasma and serum from the same blood specimen, using the Kodak Ektachem 700 XR Analyzer. For 22 of the analytes, values for plasma were practically the same as those for serum; for the other three, differences between concentrations in plasma and serum were significant, both statistically and medically. Values for the same analytes in plasma from regular heparinized tubes were essentially indistinguishable from those for plasma obtained by use of Plasma Separator Tubes (PST).
Alkaline phosphatase isoenzymes of liver and bone origin are incompletely resolved by wheat-germ-lectin affinity chromatography.
Authors: Gonchoroff D G , Branum E L , O'Brien J F 
Published: January 2020

Abstract
We used wheat-germ-lectin affinity chromatography as a tool to investigate the structure of alkaline phosphatase (ALP, EC 3.1.3.1) and to obtain fractions enriched in either bone or liver ALP activity. Liver and bone isoenzymes in serum samples were incompletely resolved except that the activity in the nonretained fraction (fraction 1) always represented pure liver isoenzyme and constituted a larger percentage of total activity in pooled sera with increased liver ALP activity than in pooled sera with increased bone activity. In contrast, a more avidly retained ALP activity, presumably with high glycosylation, was found in human serum with high activity of bone ALP. Using a solid-phase immunoassay, we examined the fractions obtained from the wheat-germ-lectin-Sepharose 4B column to determine whether the isoenzyme preference of the monoclonal antibody was markedly influenced by the degree of glycosylation. Whether samples contained high proportions of liver or of bone isoenzyme activity, the nonretained fraction contained a higher percentage of liver ALP, whereas the more strongly bound fraction contained a higher percentage of bone ALP. Except for eluted fractions that either contained no detectable N-acetylglucosamine or the highest percentage of it, the avidity of the liver-isoenzyme-specific monoclonal antibody for ALP seemed to be independent of the degree of glycosylation, suggesting that the epitope for monoclonal antibody may be expressed in some structure other than the carbohydrate moieties.
High-performance liquid-chromatographic analysis for serotonin and tryptamine excreted in urine after oral loading with L-tryptophan.
Authors: Tsuchiya H , Hayashi T , Tatsumi M , Hoshino Y , Ohtani S , Takagi N 
Published: January 2020

Abstract
We describe a method used for determining serotonin and tryptamine in urine after oral loading with their precursor amino acid. Several factors affecting prepurification and chromatographic separation of both indoleamines were optimized, including sample extraction and mobile-phase composition. Under optimal conditions, serotonin and tryptamine are extracted from urine samples together with an internal standard, and then they are separated by reversed-phase chromatography followed by native fluorescence detection. The analytical procedure is simple enough to apply to routine analysis and performable at low cost. Sensitivity and selectivity of the method are satisfactory enough to determine urinary serotonin and tryptamine. By pursuing urinary excretion of serotonin and tryptamine after oral loading with L-tryptophan (30 mg per kilogram body weight), our method proves that urinary excretion of both indoleamines increases immediately after loading and reaches a maximum in about 45 min.
Lp(a) lipoprotein concentration in serum of patients with heavy proteinuria of different origin.
Authors: Karádi I , Romics L , Pálos G , Domán J , Kaszás I , Hesz A , Kostner G M 
Published: January 2020

Abstract
We measured serum cholesterol, triglyceride, and lipoprotein Lp(a) concentrations in serum of 37 patients with massive proteinuria of different origin, comparing values with those for age- and sex-matched controls and finding significantly increased Lp(a) concentration in the total group of patients compared with controls. Lp(a) concentration was not correlated with serum cholesterol, triglyceride, serum creatinine, daily urinary protein loss, or selectivity index. Selecting the patients according to their histological diagnosis obtained by renal needle biopsy, we found divergent results in seven patients with minimal change disease (MCD) compared with 11 patients with membranoproliferative glomerulonephritis. Lp(a) in MCD patients did not differ from that controls (101 +/- 102 and 90 +/- 115 mg/L) and correlated positively with total daily urinary protein loss (r = 0.7962, P less than 0.05). In contrast, the patients with membranoproliferative glomerulonephritis had significantly higher Lp(a) values than the controls (219 +/- 222 mg/L), and Lp(a) concentrations correlated negatively with the daily protein loss in urine (r = -0.6545, P less than 0.05). The most surprising results were the marked Lp(a) concentrations in serum of three patients with primary amyloidosis and nephrosis syndrome. Our results indicate a regulatory role of the kidney in the metabolism of Lp(a) and different effects on the serum Lp(a) concentration, depending on the type of damage to renal tissue.
Calciferin and cathepsin D-like acid protease in serum in acute and chronic liver injuries in rats and humans.
Authors: Terayama H , Shimizu N , Fukuzumi R 
Published: January 2020

Abstract
Serum from patients with chronic liver diseases (chronic hepatitis, cirrhosis, and hepatomas) contained greater concentrations of calciferin (total 1.7-fold, free 3.3-fold) than that from normal subjects. There were also decreases in the concentration and affinity of the calciferin-binding protein(s) in the patients' sera, but the amount of cathepsin D (EC 3.4.23.5)-like acid protease (total and free) was within normal limits. In addition, rats with acute liver injuries (partial hepatectomy or CCl4 administration) showed increases in calciferin and acid protease in their serum. Rats subjected to continuous feeding of 3'-methyl-4-dimethylaminoazobenzene (a potent hepatocarcinogen) also showed an increase of both analytes in the earlier stages (two to eight weeks; acute phase). Later (13 weeks or more; chronic phase), however, only acid protease appeared to return to normal values.
Estrogen and progesterone receptor assays, by the EIA method (Abbott), of low-speed supernates of breast-cancer homogenates.
Authors: Hähnel R , Avenell M H , Hähnel E 
Published: January 2020

Abstract
Estrogen receptor (ER) and progesterone receptor (PR) assays were performed by solid-phase enzyme immunoassays (Abbott) on low-speed (2600 x g) and high-speed (100,000 x g) supernates of breast-cancer homogenates. The results were similar, indicating that ultracentrifugation is not essential for ER and PR assays with the Abbott kit.
Rate immunonephelometry and radial immunodiffusion compared for apolipoproteins AI and B assay.
Authors: Bachorik P S , Cloey T A 
Published: January 2020

Abstract
We measured apolipoproteins (apo) AI and B in fresh plasma samples and serum control pools by using two rate immunonephelometric assay (INA) methods (Beckman "Array" and Behring) and radial immunodiffusion (RID). Both INA methods on average gave apoAI values similar to those by RID in fresh plasma samples. The coefficients of correlation for the two INA-RID method pairs were as follows: Beckman INA vs RID, n = 94, r = 0.73; and Behring INA vs RID, n = 112, r = 0.66. The bias between the INA and RID methods was reflected reasonably well by either lyophilized or frozen control pools. For apoB, the Beckman INA measurements in fresh plasma averaged 40% lower than RID values, due almost entirely to the values assigned to calibration sera, but results by the two methods were highly correlated (n = 94, r = 0.93). The Behring INA values for fresh plasma averaged only 13% lower than RID values, but the two methods were less well correlated (n = 112, r = 0.74). Frozen control pools were most suitable for apoB analysis.
Changes in iron, zinc, and copper concentrations in serum and in their binding to transport proteins after cholecystectomy and cardiac surgery.
Authors: Fraser W D , Taggart D P , Fell G S , Lyon T D , Wheatley D , Garden O J , Shenkin A 
Published: January 2020

Abstract
Concentrations of iron, zinc, and copper and of their respective transport proteins transferrin, albumin, and ceruloplasmin were measured in serum after elective cholecystectomy and cardiac surgery. The pattern of changes in the concentrations of iron, zinc, and copper was reproducible, with an early increase in serum iron and zinc, then a decrease in the concentrations as these metals are dissociated from their serum transport proteins. Zinc and iron concentrations change before the increase in C-reactive protein, which begins 8 h after incision, whereas the copper concentration in the serum remains constant in the early postoperative period. Quantitative and kinetic differences were observed in both the trace metal and protein changes after cardiac surgery and cholecystectomy. These studies indicate the complexity of interpreting changes in trace elements in serum after surgery.
A sensitive method of screening for urinary porphobilinogen.
Authors: Buttery J E , Chamberlain B R , Beng C G 
Published: January 2020

Abstract
In this screening method for urinary porphobilinogen (PBG), urine is added to Dowex 2 resin under alkaline conditions in a test tube and mixed. The supernate is removed and the adsorbed PBG is eluted with acid and reacted with Ehrlich's reagent. We compared results with those by the Watson-Schwartz screening method, using urine samples from normal people with and without added PBG. At a PBG concentration of about five times the upper limit of normal, the resin method gave a sensitivity of 100%; the Watson-Schwartz method gave a sensitivity of 51%. At lower PBG concentrations of just over and twice the upper limit of normal, the sensitivity by the resin method was respectively 97% and 100%. With normal urine samples, the resin method gave negative results for all samples (100% specificity) and the Watson-Schwartz had 95% specificity. Our data indicate that the resin method is sensitive, specific, and reliable and is superior to the Watson-Schwartz method.
Effect of transport conditions on the stability of biochemical markers in blood.
Authors: Hankinson S E , London S J , Chute C G , Barbieri R L , Jones L , Kaplan L A , Sacks F M , Stampfer M J 
Published: January 2020

Abstract
We examined the stability of lipids, carotenoids, alpha-tocopherol, and endogenous hormones in plasma prepared from whole blood that had been mailed to a central location for processing. Initially, to simulate transport conditions, whole-blood samples were stored in the laboratory, either at room temperature or cooled, for up to 72 h before processing. In the latter samples, lipid concentrations changed up to 1.4% per day, carotenoids up to -5.5%, and hormones up to 9.5%. In a second study, analyte concentrations in plasma from cooled whole blood mailed via overnight courier were compared with those from plasma that had been immediately separated, frozen, and mailed via overnight courier. Concentrations of cholesterol, high-density lipoprotein subfraction 3, apolipoprotein B, and retinol were stable. Overall, for each marker except estradiol, the between-person variation was at least twice the within-person variation. In a third study, at least 340 micrograms of DNA was recovered from 30 mL of cool-shipped whole blood. Our results indicate that shipping whole-blood samples by overnight courier is feasible for assay of several biochemical markers of interest in epidemiological research.
Assessment of renal function by serum creatinine and creatinine clearance: glomerular filtration rate estimated by four procedures.
Authors: Van Lente F , Suit P 
Published: January 2020

Abstract
We compared creatinine concentrations in serum and urine and creatinine clearances determined by two Jaffé (Beckman's "Astra," Boehringer Mannheim Diagnostics) and two enzymatic (Kodak, Boehringer Mannheim Diagnostics) methods. Serum creatinine and creatinine clearances determined by each method were also compared with the glomerular filtration rate as measured with use of sodium [125I]iothalamate in patients with a wide range of renal function. Results between methods correlated excellently, but we saw clear method-dependent biases of up to 2.9 mg/L for serum. The highest serum creatinine values and the lowest creatinine clearances were obtained with Boehringer Mannheim Diagnostics' Jaffé method. The reciprocal of the serum creatinine and the creatinine clearance also correlated well with the glomerular filtration rate, but all methods over-estimated the glomerular filtration rates to varying degrees. Appropriate standardization of methods appears to be as important as method principle for establishing an accurate relationship between creatinine determinations and glomerular filtration rate.
Two-site immunochemiluminometric assay of intact human parathyrin in serum with use of a tracer peptide purified by reversed-phase high-performance liquid chromatography.
Authors: Böhler U , Blind E , Vogel G , Hitzler W , Flentje D , Schmidt-Gayk H 
Published: January 2020

Abstract
For this two-site immunochemiluminometric assay of intact human parathyrin (hPTH), the luminescent tracer was synthetic hPTH(53-84), conjugated via succinimide linkage to (aminobutyl)ethyl-isoluminol hemisuccinimide (abei-h). Purification of the labeled hPTH(53-84) by reversed-phase high-performance liquid chromatography allowed isolation of the conjugate having the highest incorporation of abei-h, 1.6 mol per mole of hPTH(53-84). The solid-phase antibody directed against the N-terminal part of hPTH was immobilized by adsorption onto the polystyrene surface of the assay tube and extracted the intact hPTH and N-terminal fragments. Another antibody against synthetic hPTH(53-84), which bound to the C-terminal part of intact hPTH, was indirectly labeled at its second free binding site with the abei-h-labeled hPTH(53-84). The assay has a detection limit of 0.5 pmol/L; it is accurate, precise, and reliable; and it shows a linear response for samples containing up to 100 pmol of hPTH per liter. The normal reference interval ranged from 1.8 to 5.9 pmol/L; 56 patients with primary hyperparathyroidism had concentrations ranging from 5.9 to 113 pmol/L. The concentrations detected in patients with idiopathic hypoparathyroidism were below the normal reference interval.
Alkaline phosphatase activity from human osteosarcoma cell line SaOS-2: an isoenzyme standard for quantifying skeletal alkaline phosphatase activity in serum.
Authors: Farley J R , Kyeyune-Nyombi E , Tarbaux N M , Hall S L , Strong D D 
Published: January 2020

Abstract
Earlier we described a kinetic assay for quantifying skeletal alkaline phosphatase (ALP) isoenzyme activity in serum. The precision of the assay depends on including ALP standards for the skeletal, hepatic, intestinal, and placental isoenzymes. We wondered whether human osteosarcoma cells could provide an efficient alternative to human bone or Pagetic serum as a source of the skeletal ALP standard. ALP activities prepared from five human osteosarcoma cell lines were compared with a bone-derived ALP standard with respect to heat stability and sensitivity to chemical effectors. Two of the cell lines (SaOS-2 and TE-85) contained ALP activities that resembled the bone-derived standard. We selected SaOS-2 cells for additional evaluation (as a potential source of isoenzyme standard), because they contained 40-50 times more ALP activity than did the TE-85 cells. To include the SaOS-2 cell-derived ALP activity in the quantitative isoenzyme assay, we diluted the enzyme in a solution containing heat-inactivated (i.e., ALP-negative) human serum. Surprisingly, this dilution caused a 60-125% increase in maximum enzyme activity. In the quantitative assay of ALP isoenzyme in serum, the SaOS-2 derived ALP was indistinguishable from the serum skeletal ALP standard, with respect to the above criteria and assay variations. Evidently ALP from SaOS-2 cells is suited as a standard for measuring skeletal ALP activity in this assay.
Strong association of a single nucleotide substitution in the 3'-untranslated region of the apolipoprotein-CIII gene with common hypertriglyceridemia in Arabs.
Authors: Taş S 
Published: January 2020

Abstract
A potential genetic marker for hypertriglyceridemia and coronary disease, an apolipoprotein-CIII gene allele displaying a single nucleotide substitution, was found in 71% of Arabs with primary hypertriglyceridemia. Over 96% of the unrelated adults possessing this allele showed hypertriglyceridemia. The same allele was found rarely among normotriglyceridemic subjects. In further support of involvement in hypertriglyceridemia, this allele was co-inherited with increased serum triglycerides in a three-generation family. Moreover, a gene dosage effect was also found. A mechanism of action for the allele is suggested by the findings that the subjects possessing the allele show markedly increased very-low-density lipoproteins, decreased high-density lipoproteins, and borderline chylomicronemia demonstrable by lipoprotein electrophoresis. Electrophoresis of the selectively amplified-restricted apolipoprotein-CIII DNA on agarose gel provides a rapid diagnostic test that allows identification of the subjects with this allele in less than a day.