bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of an Automated Preanalytical Robotic Workstation at Two Academic Health Centers
Authors: Holman J William , Mifflin Theodore E , Felder Robin A , Demers Laurence M 
Published: January 2020

AbstractBackground: Purchase of automated systems in today’s clinical laboratory needs justification based on demonstrable improvements in efficiency and a sound payback model. Few studies provide information on laboratory automation that focuses on the preanalytical portion of specimen processing.Methods: We recently evaluated an automated preanalytical processing unit (GENESIS FE500) at two academic health centers. This preanalytical unit processes blood specimens through automated specimen sorting, centrifugation, decapping, labeling, aliquoting, and placement of the processed specimen in the analytical rack. We quantified the output of the FE500 by processing &gt;3000 barcode-labeled specimens according to a protocol designed to test all of the features of this automated specimen-processing unit.Results: Depending on the batch size, aliquot number requested, and percentage of tubes that required centrifugation, the mean system output performance varied between 93 and 502 total tubes/h. Throughput increased when the batch size expanded from 40 or 100 samples (mean = 211 total tubes processed/h) to batch sizes of 200 and 300 tubes (mean = 474 total tube processed/h). The GENESIS FE500 processed specimen tubes differing in size from 13 × 65 mm (width × height) to 16 × 100. At one site, the FE500 was operated by one person, compared with the three individuals required to perform the same tasks manually. Finally, the specimen-processing error rate determined at one of the institutions was significantly reduced.Conclusions: We conclude that the GENESIS FE500 effectively reduces the labor associated with specimen processing; decreases the number of laboratory errors that occur with specimen sorting, labeling, and aliquoting; and improves the integrity of specimen handling throughout the steps of specimen processing.
Cystatin C: An Improved Estimator of Glomerular Filtration Rate?
Authors: Laterza Omar F , Price Christopher P , Scott Mitchell G 
Published: January 2020

AbstractBackground: Glomerular filtration rate (GFR) is routinely assessed by measuring the concentrations of endogenous serum markers such as blood urea nitrogen and serum creatinine (SCr). Although widely used, these endogenous markers are not ideal and do not perform optimally in certain clinical settings. The purpose of this review is to critically review the potential utility of cystatin C (CysC), especially in patient populations in which CysC may have an advantage over routinely used endogenous markers of GFR.Approach: In a narrative approach, we extensively review publications, primarily from the last 5 years, that address the development of methods to measure CysC, reference intervals, and the diagnostic accuracy of CysC to assess GFR. Between June 2000 and September 2001 Medline was searched using “cystatin c” as a textword, and articles that examined &gt;75 individuals (except for renal transplant studies) and/or used accepted “gold standards” for assessing GFR were selected for inclusion. A total of 17 studies are reviewed that provide reference interval data for several populations. A total of 24 studies make conclusions about the utility of CysC vs SCr and/or creatinine clearance, with 20 providing data on the sensitivity and specificity of CysC for detecting impaired GFR. These publications are organized into subgroups that deal with specific patient populations or clinical situations.Content: This review focuses on two areas: (a) the evolution of immunoassays used to determine the concentration of CysC in serum, their analytic sensitivity, and reference intervals; and (b) the diagnostic performance of CysC against other renal markers in the general population and in specific subpopulations of patients.Summary: Studies of reference intervals for CysC overwhelmingly demonstrated that CysC values in blood are independent of age and sex. Of the 24 studies that examined clinical utility, 15 concluded that CysC is superior to SCr, whereas 9 concluded that CysC is equivalent but provides no advantage. Summary ROC plot analysis of 20 studies that provide sensitivity and specificity data strongly suggests that CysC will be superior to SCr for detecting impaired GFR. Taken together, it is clear that CysC performs at least as well as SCr in the population at large and that it is likely to be superior to SCr in specific patient populations.
Diagnostic Value of Plasma Cystatin C as a Glomerular Filtration Marker in Decompensated Liver Cirrhosis
Authors: Orlando Rocco , Mussap Michele , Plebani Mario , Piccoli Pierpaolo , De Martin Sara , Floreani Maura , Padrini Roberto , Palatini Pietro 
Published: January 2020

AbstractBackground: Plasma creatinine concentration and calculated creatinine clearance are of limited value as glomerular filtration rate (GFR) markers in patients with decompensated liver cirrhosis. We assessed plasma cystatin C as an indicator of GFR in such patients.Methods: We studied 36 patients with decompensated liver cirrhosis and 56 noncirrhotic controls, both groups including individuals with normal and impaired renal function. GFR was measured in all individuals by inulin clearance, with values &lt;72 mL · min−1 · 1.73 m−2 considered decreased. We measured cystatin C and creatinine in plasma and calculated (from plasma concentrations) and measured creatinine clearances, using for them decision points of 1.25 mg/L, 115 μmol/L, and 72 and 72 mL · min−1 · 1.73 m−2, respectively.Results: Plasma cystatin C concentrations were similar in controls and cirrhotics and, at the usual cutpoint, could detect decreased GFR with similar sensitivities in the two groups (73% and 88%, respectively). Serum creatinine was markedly lower in cirrhotics and remained mostly within the reference interval at all GFR values; the diagnostic sensitivity of creatinine was much lower in cirrhotics than in controls (23% vs 64%). Lower diagnostic sensitivity was also observed for calculated creatinine clearance (53% vs 100% in controls), whereas similar sensitivities were found for measured creatinine clearance (86% and 81%) in controls and cirrhotics, respectively. ROC analysis showed that all four variables had similar diagnostic accuracies in cirrhotic patients. However, it also revealed that good diagnostic accuracies for plasma creatinine and calculated creatinine clearance can be obtained only if reference intervals different from those used for the general population are adopted.Conclusions: Plasma cystatin C concentration is an accurate GFR marker in cirrhotic patients. Plasma creatinine concentration and calculated creatinine clearance are of no practical value, as their reference values vary with the severity of the liver disease.
Single-Step Assays to Analyze CYP2D6 Gene Polymorphisms in Asians: Allele Frequencies and a Novel *14B Allele in Mainland Chinese
Authors: Ji Ling , Pan Shixiu , Marti-Jaun Jacqueline , Hänseler Edgar , Rentsch Katharina , Hersberger Martin 
Published: January 2020

AbstractBackground: Cytochrome P450-dependent monooxygenase 2D6 (CYP2D6) activity can be estimated by investigating the metabolism of model drugs or by genotyping the most common CYP2D6 alleles. For Caucasians, the CYP2D6 allele frequencies are well investigated, and single-step assays are available for genotyping, whereas allele analysis in mainland Chinese is limited.Methods: Two tetra-primer assays and one allele-specific amplification assay were developed to easily genotype the CYP2D6 alleles *8, *10, and *14 previously detected in Asians. Applying these assays in combination with established single-tube assays, we analyzed 223 DNA samples from Chinese volunteers for the CYP2D6 alleles *3, *4, *5, *6, *8, *10, and *14 and for duplication of CYP2D6.Results: Six different alleles were detected in mainland Chinese. The most frequent mutant allele was the intermediate metabolizer allele, CYP2D6*10, with a prevalence of 51.3%, followed by the poor metabolizer alleles CYP2D6*5 (7.2%) and a novel variant of CYP2D6*14. This novel *14B allele (2.0%) differs from the *14 allele by the absence of the C188T substitution and by the additional G1749C substitution. Furthermore, six duplication alleles of CYP2D6 were detected, including one duplication of the *10 allele (*10X2).Conclusions: The CYP2D6 allele frequencies in mainland Chinese shows some genetic diversity compared with Chinese from other regions: a novel *14B allele, a slightly higher frequency of the *5 allele, and a slightly lower frequency of the *10 allele than in most other Chinese populations.
Urokinase Plasminogen Activator and Its Inhibitor, PAI-1, as Prognostic Markers in Breast Cancer: From Pilot to Level 1 Evidence Studies
Authors: Duffy Michael J 
Published: January 2020

AbstractBackground: For optimum management of patients with cancer, accurate assessment of prognosis is essential. The primary determinant of outcome in malignancy is the formation of distant metastases. Urokinase plasminogen activator (uPA) is a serine protease causally involved in invasion and metastasis.Content: Data from model systems show that uPA is unequivocally involved in cancer dissemination. Consistent with its role in metastasis, multiple independent groups have shown that high uPA concentrations in primary breast cancers correlate with poor prognosis. For determining outcome, the prognostic impact of uPA was both independent of traditionally used factors and prognostic in patients with axillary node-negative disease. Paradoxically, high concentrations of plasminogen activator inhibitor (PAI-1), an endogenous inhibitor of uPA, also correlate with poor prognosis in patients with breast cancer, including the subgroup with node-negative disease. The prognostic value of uPA/PAI-1 in axillary node-negative breast cancer patients was recently confirmed in both a prospective randomized trial and a pooled analysis, i.e., two different level 1 evidence (LOE-1) studies.Conclusions: uPA and PAI-1 are among the first biological prognostic factors to have their clinical value validated using LOE-1 evidence studies. Determination of these analytes may help identify low-risk node-negative breast cancer patients for whom adjuvant chemotherapy is unnecessary.
Use of Horseradish Peroxidase- and Fluorescein-modified Cisplatin Derivatives for Simultaneous Labeling of Nucleic Acids and Proteins
Authors: van Gijlswijk Rob PM , Talman Eduard G , Peekel Inge , Bloem Judith , van Velzen Marcel A , Heetebrij Rob J , Tanke Hans J 
Published: January 2020

AbstractBackground: Microarray platforms will change immunochemical and nucleic acid-based analysis of cell homogenates and body fluids compared with classic analyses. Microarrays use labeled target and immobilized probes, rather than fixed targets and labeled probes. We describe a method for simultaneous labeling of nucleic acids and proteins.Methods: Horseradish peroxidase- and fluorescein-modified cisplatin derivatives were used for labeling of nucleic acids and proteins. These reagents, called the Universal Linkage System (ULS), bind to sulfur- and nitrogen-donor ligands present in amino acids and nucleotides. For automated screening of proteins and nucleic acids on microarrays, it is advantageous to label these biomolecules without pre- or postpurification procedures. The labeling of antibodies and nucleic acids in whole serum was therefore pursued.Results: Immunoglobulins in nonpurified serum were labeled efficiently enough to be used for immunochemistry. To investigate whether protein-adapted labeling allowed nucleic acid labeling as well, 1 μg of plasmid DNA was added to 1 μL of serum. DNA and serum proteins were simultaneously labeled, and this labeled DNA could be used as a probe for direct fluorescence in situ hybridization.Conclusion: ULS provides a direct labeling tool for the (simultaneous) modification of proteins and nucleic acids even in unpurified samples.
Rapid and Reliable Method for Cytochrome P450 2D6 Genotyping
Authors: Stamer Ulrike M , Bayerer Bettina , Wolf Stephanie , Hoeft Andreas , Stüber Frank 
Published: January 2020

AbstractBackground: Single-nucleotide polymorphisms and single-base deletions within the cytochrome P450 2D6 (CYP2D6) gene have been associated with a poor metabolizer (PM) phenotype and display a frequency of 7–10% in the Caucasian population.Methods: We developed a reliable and rapid procedure to identify five major PM-associated mutations (CYP2D6*4, *7, and *8) and deletions (CYP2D6*3 and *6) by real-time PCR with subsequent fluorometric melting point analysis of the PCR product. These polymorphisms within the CYP2D6 gene were detected by use of two primer pairs and five different pairs of hybridization probes. DNA extracted from whole blood of 323 individuals was analyzed, and results were compared with genotypes obtained by allele-specific multiplex PCR. In case of uncertain results, additional sequence analysis was performed.Results: Genotyping results by real-time PCR were 100% reliable, whereas conventional allele-specific multiplex PCR produced uncertain results for 12.1% of samples, as confirmed by sequence analysis. Costs for reagents and consumables were considerably higher for the real-time PCR technology, but labor time was reduced by 2 h compared with allele-specific PCR. The allele frequencies in the population investigated were 0.186 for allele *4, 0.026 for allele *5, 0.009 for allele *3, 0.031 for allele *6, and 0.002 for allele *8. The defective CYP2D6*7 allele was not found. In addition, three additional mutations were detected, one of them displaying a PM genotype.Conclusion: Genotyping of CYP2D6 by real-time PCR with fluorometric melting point analysis is a rapid and reliable method.
Urinary 17-Ketosteroids in Various Endocrine Disorders
Authors: Zakharycheva A A 
Published: January 2020

Abstract
On the basis of all that has been said, it is possible to state that the clinical determination of the 17-ketosteroids and their fractions (αand β) is very valuable for the diagnosis of disorders of the endocrine glands. However, in evaluating the data from these analyses, it is necessary to take into consideration the clinical picture and the results of other studies: pneumoadenography, the peripheral blood picture, biochemical data, characteristic changes in metabolism, etc.
The Rapid Determination of Calcium in Biologic Material
Authors: Appleton Harold D , West Marcia , Mandel Mary , Sala Angelo M 
Published: January 2020

Abstract
A rapid procedure for the routine determination of calcium in serum and urine has been described. 0.1 ml. of serum is titrated directly with standard EDTA, using either a calcein-KCl mixture or a calcein-thymolphthalein-KCl mixture. The end point with either indicating mixture is sharp. Excellent agreement is shown with the oxalate isolation and permanganate titration procedure.
Determination of Magnesium and Calcium in Urine
Authors: Carubelli Raul , Smith William O , Hammarsten James F 
Published: January 2020

Abstract
A procedure for the determination of both calcium and magnesium in urine is described.
The method consists of the separation of calcium from magnesium and individual spectrophotometric titrations of each using EDTA as a complexometric reagent and murexide and eriochrome black T as indicators.
Recoveries have proven very satisfactory.
The Standardization of the Van Den Bergh Reaction for Serum Bilirubin
Authors: Carter Robert E , McGann Charles J 
Published: January 2020

Abstract
Using commercially available bilirubin preparations, calibration curves for the van den Bergh reaction were obtained that differed significantly from many previously reported, The bilirubin preparations used were not considered the cause. Rather the indicator properties of azobilirubin and the instability of bilirubin pigment in conventionally employed solvents appear to account for the differences noted.
A Volumetric Method for Serum Sodium
Authors: Oesper Peter , Pauerstein Carl J 
Published: January 2020

Abstract
A simple, rapid method for determining sodium in serum is described; it requires no special equipment and no special training. Ions normally present in serum do not interfere at any conceivable physiologic concentration. The method has been tested on approximately 30 samples of serum with known sodium contents ranging from 103-175 mEq/L; the deviation from the flame photometer value averages approximately 3%.
A Procedure for the Determination of Cerebro spinal Fluid Total Protein and Gamma Globulin in Neurologic Disorders
Authors: Papadopoulos N M , Hess W C , O'Doherty D , McLane J E 
Published: January 2020

Abstract
A procedure for determinations of both γ-globulin and total protein is described. Its application for the analysis of samples of cerebrospinal fluid from non-neurologic, multiple sclerosis, and other central nervous system disorders, revealed a characteristically high ratio of γ-globulin to total protein in multiple sclerosis. These findings suggest that this simple chemical test may be used routinely as an aid in the diagnosis of multiple sclerosis.
A Simplified Procedure for the Routine Determination of Uric Acid
Authors: Sambhi Mohinder P , Grollman Arthur 
Published: January 2020

Abstract
1. A method for the colorimetric determination of serum uric acid is described which involves the adsorption of uric acid by an ionexchange resin and the addition of N-ethylmaleimide to remove interfering chromogens.
2. The procedure is simple, accurate, and suitable for routine clinical use.
3. The clinical significance of serum uric acid levels is discussed.
Excretion of Taurine during Healing of Experimental Wounds
Authors: Williamson Martin B , Passmann John M 
Published: January 2020

Abstract
A comparison of the excretion of amino acids by normal and wounded rats on a high protein and protein-free diet was made. The nontaurine amino acid nitrogen excretion was found to be the same the control and wounded animals, although the rats on the high protein diet excreted considerably more amino acid nitrogen than did those on the protein-free diet. The wounded animals on the high protein diet had the same total nitrogen output but excreted significantly larger amounts of taurine than did the nonwounded controls. The wounded animals given the protein-free diet excreted the same amount of taurine but produced more total nitrogen than did the control rats. On the basis of the total nitrogen-taurine excretion ratios, data indicate that cystine is conserved by the wounded as compared to the normal animals.
Storage of Blood Samples on Kieselguhr and the Determination of Cholinesterase Alkaline Phosphatase and Urea
Authors: Simmonds R A 
Published: January 2020

Abstract
A method is outlined for the storage of small volumes of blood and serum on kieselguhr tablets, the preparation of which is described.
Cholinesterase, alkaline phosphatase, and urea in blood samples stored in this manner have been determined, and the effects of temperature and duration of storage of the samples examined.
Determination of Serum Butanol-Extractable Iodine with a Modified Alkaline Incineration Procedure
Authors: Klein Daniel , Chernaik Joseph M 
Published: January 2020

Abstract
1. A method has been presented for the determination of serum butanol-extractable iodine. As in other methods, the serum is acidified and extracted with n-butanol, and the butanol extract is treated with Blau reagent to remove interfering compounds.
2. Total iodine in the butanol is determined by a modified alkaline incineration procedure. After removal of the butanol, crystalline bovine albumin is added, and a total iodine determination is carried out.
3. Careful consideration is given to the details of the procedure, including those for the construction of the standard iodide curve.
Commercial Control Sera in the Clinical Chemistry Laboratory
Authors: Klugerman Maxwell R , Boutwell Joseph H 
Published: January 2020

Abstract
1. The control of precision and accuracy in a clinical chemistry laboratory can be achieved only by knowledgeable and careful use of "concurrent standardization" together with the use of control sera in routine analysis. That is, within each series of analyses, both reference standards and control sera should be included as the only means by which the ultimate in reliability can be achieved.
2. The use of standard curves or calibration factors can be tolerated only when the pure reference standard is difficult to obtain, prepare, or maintain. In such cases, however, the curves or factors should be rechecked frequently and a control serum analyzed concurrently with the unknown.
3. The manufacturer or supplier should refrain from advertising his product as simultaneously a standard and a control. Secondly, he should ascertain the shelf-life of his product under the most rigorous conditions likely to be encountered and indicate this information on the label of the individual bottle or on the container of that lot of control sera. Finally, he should make every effort to reduce the cost of his product in order to make it practical for the clinical chemistry laboratory to establish and maintain an adequate control system.
Modification of the Spectrophotometric Determination of Ketone Bodies in Blood Enabling the Total Recovery of β-Hydroxybutyric Acid
Authors: Procos John 
Published: January 2020

Abstract
A method is described for the determination of ketone bodies in blood, based on (1) their conversion to acetone by boiling in Greenberg and Lester's microrefluxing units, (2) the reaction of acetone with alkaline salicylaldehyde by a modification of Thin and Robertson's microdiffusion technic, and (3) the colorimetric determination of salicylacetone in water.
A study of the effects of varying concentrations of dichromate and sulfuric acid on the recoveries of acetoacetic and β-hydroxybutyric acids is presented and the optimum reagent concentrations are established. Recoveries of 100 per cent are obtained for both acetoacetic and β-hydroxybutyric acids. The method is particularly sensitive to small changes of ketone bodies. In the range 0-8 mg. acetone per 100 ml. blood, differences of 0.06 mg./100 ml. are detected with ease.
A Method for Measurement of Cholesterol in Blood Serum
Authors: Mann George V 
Published: January 2020

Abstract
A method for measuring cholesterol in 0.1 ml. of blood serum is described. This uses the saponification and extraction procedure of Abell et al. (4) and the color reaction of Zlatkis et al. (7). The procedure is shown to be accurate and reproducible. It is compared with several commonly used procedures and shown to be equal or superior to these. An adaptation of the method to filter-paper stored samples described. The method is recommended for use in clinical laboratories.
Determination of Urinary Creatine
Authors: Kurohara Samuel S 
Published: January 2020

Abstract
A method of separation of creatine using ion-exchange chromatography is described. This method is suitable for serial determinations of urinary creatine despite a small contribution by creatinine and guanidino compounds to the color value of the α-naphthol and diacetyl reaction. The creatine coefficients of four patients, determined in duplicates, before and after the induction of creatinuria by X-irradiation are presented to illustrate the applicability of the method described.
Measurement of Urinary Estrogens
Authors: Hobkirk R 
Published: January 2020

Abstract
In a commentary on the existing methodology for the determination of urinary estrogens, data are given for normal ranges in nonpregnancy and pregnancy urine as well as the expected interferences due to medication and substances occurring in high concentrations in disease states. Because of the wide range of normal excretion values, the point is made that only serial analyses of a patient's physiologic course (e.g., in pregnancy associated with diabetes) are of clinical value.