bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metabolism of anabolic androgenic steroids
Authors: Schänzer W 
Published: January 2020

Abstract
Anabolic androgenic steroids (AAS) are misused to a high extent in sports by athletes to improve their physical performance. Sports federations consider the use of these drugs in sports as doping. The misuse of AAS is controlled by detection of the parent AAS (when excreted into urine) and (or) their metabolites in urine of athletes. I present a review of the metabolism of AAS. Testosterone is the principal androgenic steroid and its metabolism is compared with that of AAS. The review is divided into two parts: the general metabolism of AAS, which is separated into phase I and phase II metabolism and includes a systematic discussion of metabolic changes in the steroid molecule according to the regions (A-D rings), and the specific metabolism of AAS, which presents the metabolism of 26 AAS in humans.
Use of precision profiles to evaluate precision of the automated leukocyte differential
Authors: Hübl W , Tlustos L , Bayer P M 
Published: January 2020

Abstract
The commonly used methods of assessing the precision of the automated leukocyte differential have certain drawbacks that affect the validity and comparability of results. In the present report, we introduce a procedure based on building precision profiles from a large number of within-run imprecision experiments. The profiles are fitted to the function for the CV of proportions, which yields the number of theoretically differentiated leukocytes. Differences between fitted curves are evaluated for statistical significance by the F-test. As an example, we compared the precision of two hematology analyzers, a flow-cytometric technique involving fluorescence-labeled monoclonal antibodies, and the manual differential. We were able to establish definite differences in precision between different analyzers and different leukocyte classes. Our data also indicated that conventional within-run imprecision studies may completely misjudge analyzer precision. Furthermore, we could demonstrate that the precision of analyzers that analyze a fixed amount of blood rather than a fixed number of leukocytes is strongly influenced by the leukocyte count of the sample, leading to high imprecision for leukopenic samples. We believe the proposed procedure is a useful addition to currently used protocols; it yields clear results and creates a statistical basis of comparison between various instruments and techniques of differentiation.
Robust, reliable biosensor for continuous monitoring of urea during dialysis
Authors: Della Ciana L , Caputo G 
Published: January 2020

Abstract
We developed a new urea sensor for the on-line monitoring of hemodialysis adequacy. The biosensor consisted of an immobilized urease cartridge placed between magnetoinductive conductivity cells. The biosensor output was taken as the conductivity difference between these cells. The device was placed on the ultrafiltrate line of a paired filtration dialysis system. The amount of urease present in the cartridge was sufficient for the complete conversion to ammonium carbonate of urea up to 35 mmol/L. Agreement was good between the urea concentration by the biosensor method and an automated analyzer for seven patients: range 8.07-30.3 mmol/L (22.6-84.8 mg/dL blood urea nitrogen, BUN); intercept 0.20 +/- 0.1 mmol/L (0.55 +/- 0.4 mg/dL BUN); slope 1.01 +/- 0.01; r 0.997; S(y/x) 0.40 mmol/L (1.11 mg/dL BUN). The device proposed meets the requirements of accuracy, cost, ruggedness, and ease of use (no calibration required) for a biosensor to be used for continuous monitoring of hemodialysis.
Validation of HPLC-amperometric detection to measure serotonin in plasma, platelets, whole blood, and urine
Authors: Pussard E , Guigueno N , Adam O , Giudicelli J F 
Published: January 2020

Abstract
We describe an isocratic liquid-chromatographic method with amperometric detection for determination of serotonin by rapid sample preparation. Platelet-poor plasma and platelets were injected after a single deproteinization step with perchloric acid. Addition of sodium borohydride to whole blood avoids oxidation of serotonin during the deproteinization step without any chromatographic interferences. We purified urinary serotonin by two successive cationic and anionic extraction steps. After urine dilution, urinary 5-hydroxyindoleacetic acid (5-HIAA) was measured under the same chromatographic conditions. Platelet serotonin concentrations correlated more closely with whole-blood serotonin concentrations after correction for platelet number than with concentrations expressed in nmol/L. This suggests that whole-blood serotonin measurements should be corrected for platelet count to eliminate the variability of circulating platelets. Combined determination of serotonin in whole blood and urine and of 5-HIAA in urine provides a useful tool for detecting and monitoring carcinoid tumors.
Development of a two-site solid-phase immunochemiluminescent assay for measurement of dimeric inhibin-A in human serum and other biological fluids
Authors: McConnell D S , Padmanabhan V , Pollak T B , Groome N P , Ireland J J , Midgley A R 
Published: January 2020

Abstract
Inhibin is a heterodimeric glycoprotein that inhibits the secretion of follitropin from the pituitary and has been isolated in two distinct forms composed of a common alpha subunit and either a beta A or beta B subunit. Utilizing paired monoclonal antibodies specific to the alpha and beta A subunit, we have developed an immunochemiluminescent assay for dimeric inhibin-A. The assay is capable of quantifying free and bound inhibin-A in human serum and follicular fluid. The limit of detection is 10 ng/L. Related proteins exhibit little cross-reactivity or interference. Recovery is excellent. Whereas samples from men and postmenopausal women are near the detection limit of the assay, inhibin-A is higher in the luteal than the follicular phase of normally cycling women, 20-fold higher during in vitro fertilization treatment, and approximately 200-fold greater in pregnancy. The assay measures inhibin-A in follicular fluid from a variety of other species.
Rapid method for visual identification of specific DNA sequences based on DNA-tagged liposomes
Authors: Rule G S , Montagna R A , Durst R A 
Published: January 2020

Abstract
We describe a rapid method for visually determining specific DNA sequences at femtomole concentrations. Liposomes, encapsulating a red dye and labeled with oligonucleotide, were used in a capillary migration-sandwich hybridization assay. Capture probe was immobilized on nitrocellulose strips, and liposomes, migrating along each strip, formed a visually discernible band in the presence of target DNA. One femtomole of synthetic target sequence could be detected in &lt; 10 min. Sufficiently stringent hybridization conditions can be used to allow the discrimination of a 10% mismatch sequence from perfectly complementary DNA. A 366-base PCR product was detected at 200 fmol.
Development and evaluation of a urine protein expert system
Authors: Ivandić M , Hofmann W , Guder W G 
Published: January 2020

Abstract
Based on the quantitative determination of creatinine, total protein, albumin, alpha 1-microglobulin, IgG, alpha 2-macroglobulin, and N-acetyl-beta, D-glucosaminidase in urine in combination with a test strip screening, the findings of hematuria, leukocyturia, and proteinuria can be assigned to prerenal, renal, or postrenal causes. Using this graded diagnostic strategy as a knowledge base, we developed a computerbased expert system for urine protein differentiation ("UPES") as a decision-supporting tool. The knowledge base was implemented as a combination of "if/then" rules and two-step bivariate distance classification of marker proteins. The knowledge for this form of pattern recognition was derived from the results for a set of 267 patients with clinically and histologically documented nephropathies. To determine the diagnostic value of UPES, we tested another set of data: results for 129 urine analyses from 94 patients. Using these data, the system reached 98% concordance with the clinical diagnoses for the patients and was superior to the diagnostic interpretations of four human experts. UPES has been successfully integrated into the laboratory routine process, including automated data import.
Validation protocol of analytical hemostasis systems: measurement of anti-Xa activity of low-molecular-weight heparins
Authors: Houbouyan L , Boutière B , Contant G , Dautzenberg M D , Fievet P , Potron G , Vassault A , Gourmelin Y 
Published: January 2020

Abstract
A standard validation protocol adapted to the chromogenic assay of anti-Xa activity of low-molecular-weight heparins was used in a multicenter study to assess its suitability for comparing and evaluating analytical hemostasis systems. The protocol included: familiarization with the system (repeatability); assessment of limits of linearity, detection limits, and cross-contamination; and validation (reproducibility and accuracy of measurements of treated patients' plasmas). We calibrated the systems with the same range of lyophilized plasmas daily and evaluated repeatability and reproducibility by using a single batch of lyophilized plasmas at three anti-Xa activities. The two automated systems tested [SB 300 (Gilford) and ACL (IL)] and the two semiautomated systems [ST 888 (D. Stago) and Chromotimer (Behring)] gave similar mean values. Dispersion of results was lower with the automated systems than with the semiautomated ones, especially at low anti-Xa activities, a tendency that also was observed for reproducibility. Because each analytical system gave linear results for activities as great as 1000 IU/L, suitable sample dilution is advisable for higher anti-Xa activities. Accuracy was greater in the automated systems. We conclude that this protocol is feasible and is applicable to validation of other analytical hemostasis instruments, in particular the latest generation of fully automated instruments.
Clinical studies of drug effects in humans
Authors: Ray W A 
Published: January 2020

Abstract
Many important drug properties cannot be predicted from in vitro or animal studies but must be quantified from studies of clinically relevant endpoints in humans. Clinical study designs include the randomized controlled trial (RCT) and a variety of observational designs. In RCTs, randomization usually ensures treatment group comparability with respect to other factors, so outcome differences reflect treatment differences per se. Properly conducted RCTs thus are the strongest study design, the mainstay of mandatory premarketing studies, and essential for evaluation of therapeutic efficacy. RCT limitations include frequent use of surrogate endpoints, limited power, short-term follow-up, and cross-contamination of study groups. For ethical reasons, some questions cannot be studied with RCTs. The simplest observational design, the case series, has limited value because it lacks a denominator. Limitations of cohort and case-control studies include misclassification, selection bias, and confounding. Despite their limitations, properly conducted experimental and observational clinical studies provide essential data for clinical practice.
Toxic effects of immunosuppressive drugs: mechanisms and strategies for controlling them
Authors: Shaw L M , Kaplan B , Kaufman D 
Published: January 2020

Abstract
Since cyclosporine (CsA) was introduced into clinical practice in late 1983 to prevent rejection in transplant patients, there has been an almost explosive growth in the number and types of transplants and the number of transplant centers, an increase in the life expectancy of the transplanted organ, and substantial decreases in rates of acute rejection and life-threatening infections. Despite these successes, major improvements in immunosuppressive therapy are needed, especially a reduction in toxic side effects and a rigorous definition of the relation between drug concentration and clinical effects. Such improvements may be achievable with the incorporation of new drugs such as tacrolimus and mycophenolate mofetil into immunosuppression protocols and the development of rigorously defined therapeutic drug-monitoring programs.
Clinical evaluation of the poisoned patient and toxic syndromes
Authors: Liang H K 
Published: January 2020

Abstract
Poisonings and toxic exposures are prominent causes of morbidity and mortality in patients that present to the emergency department. The American Association of Poison Control Centers, in its 1994 annual report, cites a 10% increase in the number of reported cases of poison exposure. The clinical evaluation and management of such patients remain challenging. Few specific antidotes are available for the many potential poisonings that occur annually. Rapid stabilization, resuscitation, and recognition of major toxic syndromes, along with appropriate utilization of laboratory testing, guide the clinician in the treatment of such patients.
Pediatric poisonings
Authors: Goepp J G 
Published: January 2020

Abstract
In a general exposition of clinical and laboratory issues in the emergency management of poisoning in the pediatric patient I briefly discuss the epidemiology of poisonings in the child population, the categories of poisons to which children are exposed most frequently, and clinical and laboratory considerations, focusing on the importance of understanding the pharmacological properties of the compound involved. I review diagnostic and therapeutic decision-making in light of the characteristics of the known or suspected chemical involved. Finally, the information presented is integrated in a discussion of two cases of poisoned patients in a hospital emergency department.
Comparative sensitivities and specificities of the mass measurements of CK-MB2, CK-MB, and myoglobin for diagnosing acute myocardial infarction
Authors: Laurino J P , Bender E W , Kessimian N , Chang J , Pelletier T , Usategui M 
Published: January 2020

Abstract
We evaluated the clinical utility of the mass measurement of the tissue isoform of creatine kinase MB isoenzyme (CK-MB2) in the diagnosis of an acute myocardial infarction (AMI) by determining its sensitivity, specificity, and predictive value relative to those of CK-MB mass and myoglobin. Samples were obtained at 0, 4, 8, and 16 h postpresentation from 100 patients (41% with AMI). The order of sensitivity for the sample proportions taken at 0-2 h from the onset of symptoms was myoglobin &gt; CK-MB2 &gt; CK-MB. At all other time points, the sensitivity of CK-MB2 either equaled or surpassed that of both CK-MB and myoglobin, although the 95% confidence intervals for the population proportions each of these markers overlapped. Of the 41 AMI patients, 31 (76%) exhibited concurrent abnormal increases of CK-MB and %CK-MB2; the other 10 (24%; 8 non-Q wave, 2 Q wave) exhibited abnormal values for %CK-MB2 before their CK-MB exceeded the upper limit of normal. The specificity of myoglobin was statistically lower than that for either CK-MB2 or CK-MB at all time points.
Evaluation of the Du Pont Axial Separation system
Authors: Perkins S L , Adams G A 
Published: January 2020

Abstract
We evaluated the Du Pont Axial Separation Technology (AST) system, which permanently separates a blood specimen into serum or plasma and cells in 1 min. Blood was collected in axial processing containers by standard venipuncture techniques and processed in an Axial Separation Module. Paired patient samples (n = 48 serum pairs, n = 50 plasma pairs) revealed no clinically significant differences in results for common chemistry analytes from samples collected in Becton Dickinson Vacutainer Tubes and centrifuged conventionally vs those from samples collected and processed in the AST system, except for a bias in serum (but not plasma) lactate dehydrogenase activity. This bias was dependent on the extent of stretching of the clot during processing and could be minimized by clotting the blood sample horizontally (axially). We believe the rapid separation of blood by the AST system has the potential to substantially reduce preanalytical specimen handling time.
Using Shewhart p control charts of external quality-assurance program data to monitor analytical performance of a clinical chemistry laboratory
Authors: Chesher D , Burnett L 
Published: January 2020

Abstract
We have investigated the application of Shewhart's p control charts in our external quality-assurance program to monitor the long-term performance of our laboratory's analytical quality. The p control charts have been able to detect long-term changes in our laboratory's analytical performance that would have been difficult to detect by more-conventional techniques. We have explored methods for interpreting these charts as well as some of their limitations, which include minimum subgroup size and dependence on constant specification limits. These charts may be not only a simple method for the long-term monitoring of analytical performance of a laboratory, but also of use to the organizers of external quality-assurance programs.
Towards artificial antibodies prepared by molecular imprinting
Authors: Ansell R J , Ramström O , Mosbach K 
Published: January 2020

Abstract
The new technique of molecular imprinting has increasingly been adopted by research laboratories worldwide during the last few years. We have studied the use of such imprints against drugs as artificial antibody-binding mimics in competitive radioimmuno-style binding assays. The recognition sites "molded" in the polymers mimic the binding sites of natural antibodies in their interactions with the target antigen. Binding constants are as low as 4.0 nmol/L for a small number of well-defined sites, and cross-reactivities are similar to or better than those observed with biological antibodies. In some cases, the polymers have been used to determine drug concentrations in human serum specimens.
Luminescent oxygen channeling assay (LOCI): sensitive, broadly applicable homogeneous immunoassay method
Authors: Ullman E F , Kirakossian H , Switchenko A C , Ishkanian J , Ericson M , Wartchow C A , Pirio M , Pease J , Irvin B R , Singh S , Singh R , Patel R , Dafforn A , Davalian D , Skold C , Kurn N , Wagner D B 
Published: January 2020

Abstract
Luminescent oxygen channeling assay (LOCI) is a homogeneous immunoassay method capable of rapid, quantitative determination of a wide range of analytes--including high and very low concentrations of large and small molecules, free (unbound) drugs, DNA, and specific IgM. Assays have been carried out in serum and in lysed blood. Reliable detection of 1.25 microU/L thyrotropin (TSH) and 5 ng/L hepatitis B surface antigen (HBsAg) corresponds to detection limits approximately 3- and approximately 20-fold lower, respectively, than those of the best commercially available assays. An assay of chorionic gonadotropin is capable of quantification over a 10(6)-fold range of concentrations without a biphasic response. Latex particle pairs are formed in the assay through specific binding interactions by sequentially combining the sample and two reagents. One particle contains a photosensitizer, the other a chemiluminescer. Irradiation causes photosensitized formation of singlet oxygen, which migrates to a bound particle and activates the chemiluminescer, thereby initiating a delayed luminescence emission. Assay times range from 1 to 25 min.
Ultra-specific immunoassays for small molecules: roles of wash steps and multiple binding formats
Authors: Self C H , Dessi J L , Winger L A 
Published: January 2020

Abstract
New immunometric forms of immunoassay are much more flexible to use than competitive-format immunoassays for small molecular analytes. An example of the utility of this flexibility is the ability to wash the capture antibody after it has been exposed to analyte but before addition of the labeled reagent. This simple maneuver has a large impact on the specificity obtained from already highly specific assays. We also show that specificity can be further increased by means of our multiple binding assay approach, in which the final reading reflects analyte binding to two different primary capture monoclonal antibodies.
Detection of immobilized amplicons by ELISA-like techniques
Authors: Oroskar A A , Rasmussen S E , Rasmussen H N , Rasmussen S R , Sullivan B M , Johansson A 
Published: January 2020

Abstract
The NucleoLink surface is a physically modified, thermostable, optically clear resin. It allows the covalent binding of 5'-phosphorylated oligonucleotides. Target DNA amplification by polymerase chain reaction (PCR) is accomplished by asymmetric amplification on the covalently immobilized primer that develops into immobilized amplicons. A DNA fragment of bovine leukemia virus is used as a model system for the detection of immobilized amplicons by ELISA-like techniques. Covalently bound oligonucleotides are also utilized as capture probe in the hybridization-based signal amplification for detection of an infectious organism.
Regulatory hurdles in bringing an in vitro diagnostic device to market
Authors: Smith K M , Kates J A 
Published: January 2020

Abstract
We discuss the hurdles that developers and manufacturers of in vitro diagnostic devices face in obtaining regulatory approval to market their products in the US. A thorough understanding of medical device regulation and the early planning of a clinical and regulatory strategy are imperative in assuring successful and timely launches of new products. Finally, it is critical for manufacturers to establish a working partnership with the Food and Drug Administration to expedite their new product applications.
A parallel revolution: payment for new in vitro diagnostic technologies
Authors: Ivor L P 
Published: January 2020

Abstract
To secure a successful product in today's era of cost containment, manufacturers and developers of new in vitro diagnostic technologies must consider payment issues--coverage and reimbursement by healthcare insurers--as critical market forces that must be addressed in the business plan. Similar to the regulatory hurdles involving 510(k)s and premarket applications, the requirements for payment are related to the unique features of the technology, its costs, and its effect on clinical outcomes. Because cost containment continues to be a driving force for change in healthcare, the business plan must not only include strategies for optimal payment at the product's introduction, but also contain provisions for continuous monitoring of the payment environment throughout the product's life cycle.