bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sodium dodecyl sulfate-agarose gel electrophoresis of urinary proteins: application to multiple myeloma
Authors: Le Bricon Thierry , Erlich Danielle , Bengoufa Djaouida , Dussaucy Michelle , Garnier Jean-Pierre , Bousquet Bernard 
Published: January 2020

Abstract
We evaluated a new sodium dodecyl sulfate-agarose gel electrophoresis (SDS-AGE) for urinary protein analysis in patients with multiple myeloma (MM; n = 47; ages, 62 ± 2 years, mean ± SE). Abnormal proteinuria (mean = 1872 ± 360 mg/24 h) was present in 95% of the samples; 75% of the patients had some sign of renal dysfunction (glomerular and/or tubular) according to their SDS-AGE pattern. A band suggesting Bence Jones proteinuria (BJP) was detected in 40 vs 33 specimens by routine AGE. Immunofixation identified BJP in 38 patients; the calculated sensitivity of SDS-AGE for BJP was 97%. Excellent correlation (P &lt;0.0001) was obtained with routine AGE (r = 0.994) and immunonephelometry (r = 0.963) for light chain quantification. SDS-AGE allows easy evaluation of renal dysfunction and shows high sensitivity for BJP detection. In a specialized laboratory, it is useful for following the progress of MM patients through the semiquantification of BJP.
Low percentage of aluminoxamine and ferrioxamine in uremic serum after desferrioxamine administration
Authors: Menéndez-Fraga Pilar , Fernández-Martín Jose L , Blanco-González Elisa , Cannata-Andía Jorge B 
Published: January 2020

AbstractHPLC was used to study the effectiveness of two different desferrioxamine (DFO) administration strategies (15 mg/kg DFO, 1 h or 44 h before dialysis) on generation of aluminoxamine and ferrioxamine in five hemodialysis patients. The percentage of ultrafilterable aluminum and iron in these patients was also investigated by electrothermal atomic absorption spectrometry. The administration of DFO in both schemes increased the ultrafilterable serum aluminum concentrations from a mean of 17.1 ± 1.6% to a mean of 75.7 ± 14.1%. However, 1 h after DFO infusion, only 38.8 ± 7.7% of the total serum aluminum was bound to DFO; 44 h after DFO infusion, only 15.8 ± 8.0% was bound. Similar results were obtained for ferrioxamine. These results suggest that the ultrafilterable serum fraction contains aluminum and iron chelated by DFO and by DFO metabolites, which retain similar metal-chelating abilities.
Predictive value of determinations of zinc protoporphyrin for increased blood lead concentrations
Authors: Froom Paul , Kristal-Boneh Estella , Benbassat Jochanan , Ashkanazi Ruth , Ribak Joseph 
Published: January 2020

Abstract
Blood lead (PbB) and red cell zinc protoporphyrin (ZPP) concentrations are widely used biomarkers for lead toxicity. It is uncertain, however, whether either or both are needed for monitoring lead exposure and how discordant PbB and ZPP values should be interpreted. We reviewed the results of PbB and ZPP determinations in 94 workers in a lead-battery plant over a 13-year period and retrieved all 807 sets of tests in which both PbB and ZPP were available, with a follow-up PbB value 6 months later. PbB exceeded 1.93 μmol/L (40 μg/dL) in 414 (51%), and 2.90 μmol/L (60 μg/dL) in 105 (14%) of the blood samples. We derived the test properties of various ZPP concentrations for concurrent “toxic” PbB concentrations, defined as ≥1.93 and 2.90 μmol/L (40 and 60 μg/dL). The results indicated that, given a population of lead-exposed workers with a 10% prevalence of PbB of ≥2.90 μmol/L (60 μg/dL), a policy of testing PbB only in those with ZPP &gt;0.71 μmol/L (40 μg/dL) would obviate 42% of the PbB tests, but would miss about three cases with toxic PbB concentrations in every 200 workers at risk. A finding of increased ZPP concentrations with a concurrent “nontoxic” PbB was associated with an increased risk of a toxic PbB concentration 6 months later. We conclude that (a) screening by testing only ZPP does not safeguard exposed persons against lead toxicity, and (b) the frequency of PbB monitoring should be guided by estimates of the risk of future lead toxicity in individual workers.
Effect of serum-clot contact time on clinical chemistry laboratory results
Authors: Zhang Dongbo J , Elswick R K , Miller W Greg , Bailey Jimmy L 
Published: January 2020

AbstractThe effect of serum-clot contact time on laboratory results was studied by dividing each blood specimen into four blood collection tubes. The control sera were separated from the clot within 30 min of the collection. The other tubes were incubated at 32 °C, and the sera were separated at 3, 6, and 24 h. The sera were stored at 4 °C and analyzed at the same time. The stability of the tests was determined by comparing the results of the 3-, 6-, and 24-h samples with the values from the 30-min samples. The acceptable limits around the 30-min values were derived from the analytical and intraindividual biological variation of the tests. A total of 63 analytes were studied. Potassium, phosphorous, and glucose were the least stable, and the serum should be separated from the clot within 3 h for these analytes. Albumin, bicarbonate, chloride, C-peptide, HDL-cholesterol, iron, LDL-cholesterol, and total protein should be separated within 6 h. The other analytes were stable for 24 h of serum-clot contact.
Correlation of plasma concentrations of cystatin C and creatinine to inulin clearance in a pediatric population
Authors: Stickle Douglas , Cole Barbara , Hock Karl , Hruska Keith A , Scott Mitchell G 
Published: January 2020

AbstractMeasurement of blood concentrations of cystatin C (cysC), a cysteine protease inhibitor present in human plasma, has been suggested for use as an indicator of glomerular filtration rate (GFR) in a manner analogous to the use of plasma creatinine (SCR). In this study, cysC and SCR were measured in plasma from pediatric patients (4–19 years) with renal disease for whom a “gold standard” measurement of GFR via inulin clearance (CIN) was available. The data analyses were divided into two age groups: group A (4–12 years, n = 26) and group B (12–19 years, n = 34). For both age groups, the linear correlation coefficient of [cysC]−1 vs CIN (mL/min/1.73 m2) (r = 0.765 for group A and r = 0.869 for group B) was less than that of the linear correlation coefficient of [SCR]−1 vs CIN (r = 0.841 for group A and r = 0.892 for group B). As a single measurement for detection of abnormal GFR, however, the optimum receiver-operator characteristic point for cysC measurement (for group A at cysC &gt;1.2 mg/L, sensitivity = 80%, specificity = 91%; and for group B at cysC &gt;1.4 mg/L, sensitivity = 87%, specificity = 100%) was numerically superior to that for SCR measurement (for group A at SCR &gt;8.0 mg/L, sensitivity = 67%, specificity = 100%; and for group B at SCR &gt;9.0 mg/L, sensitivity = 91%, specificity = 91%), using a reference value for normal GFR of CIN &gt; 90 mL/min/1.73 m2. However, these differences were not statistically significant. CysC measurement appears to be broadly equivalent to SCR measurement for estimation of GFR in pediatric patients.
Cardiac troponins I and T in patients with suspected acute coronary syndrome: a comparative study in a routine setting
Authors: Hetland Øyvind , Dickstein Kenneth 
Published: January 2020

Abstract
We compared cardiac troponin I (cTnI), using Access®, Sanofi Pasteur, and cardiac troponin T (cTnT), using Elecsys®, Boehringer Mannheim, in the first two routine blood samplings in a routine panel of cardiac markers for the biochemical diagnostic evaluation of patients with symptoms of acute myocardial infarction (AMI). No significant differences in the overall clinical performances of cTnI and cTnT were observed for the diagnosis of AMI (n = 68), but cTnI demonstrated lower initial sensitivity and higher specificity compared with cTnT. cTnT was increased to higher relative values than cTnI (P = 0.023). Discordances were found between cTnI and cTnT in sample I but not in sample II; positive cTnT/negative cTnI was more common than the opposite discordance (P = 0.027). cTnT was more frequently increased in patients with unstable angina pectoris (UAP) than cTnI (P = 0.038), with no significant differences between sample I and sample II; discordant results with respect to cTnI and cTnT appeared in 6 (33%) of these patients, all of which were positive for cTnT and negative for cTnI. Four patients with UAP (22%) developed AMI within 4 months; three were associated with increased cTnI and cTnT at the time of initial testing, and one was discordant (positive cTnT). In patients classified with no acute coronary syndrome (n = 84), five concordant positives for cTnI and cTnT were observed, indicating the existence of a myocardial injury of recent origin in these patients. AMI evolved in one of these patients 5 months later. We conclude that cTnT and cTnI detect acute myocardial injury with equal clinical performance in AMI patients classified by WHO criteria. cTnT was more frequently increased in patients with UAP than cTnI, but the clinical significance of this discordance could not be determined from this study.
Response of several markers of bone collagen degradation to calcium supplementation in postmenopausal women with low calcium intake
Authors: Kamel Saïd , Fardellone Patrice , Meddah Boumedienne , Lorget-Gondelmann Florence , Sebert Jean Luc , Brazier Michel 
Published: January 2020

AbstractWe investigated the response of bone-specific resorption markers in fasting urine samples from postmenopausal women with low daily dietary calcium (Ca) intake (&lt;800 mg/day) who received either Ca supplementation (1200 mg/day, n = 18) or placebo (n = 14) for 2 months. We measured urinary hydroxyproline, total pyridinoline, and deoxypyridinoline by HPLC, and free deoxypyridinoline (i-F-Dpd) and N- and C-telopeptide fragments of type I collagen (NTX and CTX) by immunoassays. Before supplementation, the urine concentrations of bone resorption markers in the 32 subjects were not statistically different from those measured in 21 subjects with daily dietary Ca intake &gt;800 mg/day. In contrast to the placebo group, Ca supplementation decreased all collagen-related degradation markers except i-F-Dpd as early as the first month. The magnitude of response after 2 months of Ca supplementation, expressed as mean percentage of decrease from baseline values or as individual Z scores, was greatest for the telopeptide assays. Furthermore, the percentage of change assessed at 2 months was greater than the within-person biological variability (CV) assessed in the placebo-treated women for NTX and CTX, whereas for the other markers the percentage of change was very close of the within-person CVs. We conclude that cross-linked telopeptide fragments of type I collagen most sensitively reflect the change in bone resorption after Ca supplementation.
Cross-reactivity of fosphenytoin in two human plasma phenytoin immunoassays
Authors: Kugler Alan R , Annesley Thomas M , Nordblom Gerald D , Koup Jeffrey R , Olson Stephen C 
Published: January 2020

AbstractThe cross-reactivity of fosphenytoin, a phosphate ester prodrug of phenytoin, was investigated in the Abbott phenytoin TDx®/TDxFLxTM fluorescence polarization immunoassay (TDx) and the Behring Diagnostics phenytoin Emit® 2000 enzyme-multiplied immunoassay (Emit). The first part of our study investigating cross-reactivity utilized in vitro correlation of the two immunoassays with a validated and specific phenytoin HPLC method used to assay plasma samples prepared in several phenytoin and fosphenytoin concentration combinations. Fosphenytoin cross-reacted with both immunoassays, but to a greater extent with TDx. In the second part of the study, empirically-derived models that best explained the in vitro data were used to predict “immunoassay-derived” phenytoin concentrations in plasma samples collected from actual patients after intravenous (IV) or intramuscular (IM) fosphenytoin dosing. The greatest degree of phenytoin concentration overestimation occurred at times when fosphenytoin concentrations were highest: within 1 to 2 h after IV infusion or during the first 2 to 4 h after IM injection. It is recommended that phenytoin concentrations not be monitored using these or other potentially nonspecific immunoanalytical methods for at least 2 h after IV fosphenytoin infusion or 4 h after IM fosphenytoin injection.
Biological variation of cystatin C: implications for the assessment of glomerular filtration rate
Authors: Keevil Brian G , Kilpatrick Eric S , Nichols Simon P , Maylor Paul W 
Published: January 2020

Abstract
To assess the inherent potential for detecting mild to moderate reductions in glomerular filtration rate, this study determined the biological variability of serum cystatin C and creatinine in 12 healthy subjects. After accounting for analytical variation, interindividual variance accounted for 93% and intraindividual variance accounted for 7% of serum creatinine biological variation. As such, to lie outside the assay reference interval, some subjects must exceed 13 SD from their usual mean value, whereas in others, a change of only 2 SD would be sufficient. For cystatin C, interindividual variation explained 25% and intraindividual variance explained 75% of biological variability. Therefore, the upper limit of the population reference interval for cystatin C is seldom more than 3–4 SD from the mean value of any healthy individual. The critical difference for sequential values significant at P ≤0.05 was calculated as 37% for serum cystatin C and 14% for serum creatinine. We conclude that cystatin C is potentially a better marker for detecting impaired renal function than serum creatinine, but serum creatinine is probably still the better marker for detecting temporal changes of renal function in individuals with established renal disease.
Evaluating stat testing options in an academic health center: therapeutic turnaround time and staff satisfaction
Authors: Kilgore Meredith L , Steindel Steven J , Smith John A 
Published: January 2020

Abstract
We compared centralized vs distributed methods for delivering “stat” test results for blood gas, glucose, and electrolyte assays. The parameters for comparison were as follows: (a) laboratory turnaround time (TAT), (b) therapeutic TAT, and (c) staff satisfaction. Therapeutic TAT, defined as the time from the initiating order to the receipt of the result and the implementation of any indicated change in treatment, was obtained by direct observation of testing procedures at the bedside and timing each step in the process. Observing therapeutic TAT yields information on the impact of laboratory testing methods in the context of clinical decision making. Therapeutic TAT was 1–2 min shorter for bedside testing compared with a satellite laboratory and 9–14 min shorter in the satellite laboratory compared with centralized testing. Satellite laboratories received the highest staff satisfaction scores, followed by bedside testing, with the central laboratory receiving the lowest scores.
Correlation of sperm motility with mitochondrial enzymatic activities
Authors: Ruiz-Pesini Eduardo , Diez Carmen , Lapeña Ana Cristina , Pérez-Martos Acisclo , Montoya Julio , Alvarez Enríque , Arenas Joaquín , López-Pérez Manuel J 
Published: January 2020

AbstractUntil now, little attention has been paid to the contribution of mitochondrial dysfunction to germinal tissue disorders. The target of this study was to investigate the relationship between sperm motility and mitochondrial respiratory chain enzyme activities. The results obtained showed that semen samples of control individuals (n = 33) have substantially higher activities of complexes I, II, and IV compared with those of asthenozoospermic subjects (n = 86). Moreover, a direct and positive correlation was found in the whole population studied between spermatozoa motility and all the mitochondrial respiratory complex activities assayed (I, II, I+III, II+III, and IV). The ratio of these enzymes to citrate synthase (a reliable enzymatic marker of mitochondrial volume) activities did not correlate with sperm motility. This suggests that motility depends largely on the mitochondrial volume within the sperm midpiece. These observations could be of physiopathological relevance because they suggest that factors affecting the mitochondrial energy production could be then responsible for particular cases of idiopathic asthenozoospermia.
Medicare’s demonstration of competitive bidding for clinical laboratory services: what it means for clinical laboratories
Authors: Hoerger Thomas J , Lindrooth Richard C , Eggleston Jennifer L 
Published: January 2020

Abstract
The purpose of Medicare’s Demonstration of Competitive Bidding for Clinical Laboratory Services is to determine whether competitive bidding can be used to provide quality laboratory services at prices below current Medicare reimbursement rates. Here, we present key features of the preliminary design for the demonstration. The following areas are covered: scope of the demonstration, bidding process, selection of winners, reimbursement, quality, and administration and monitoring. The role of the Health Care Financing Administration’s Laboratory Technical Advisory Committee is also described, and the future of competitive bidding in a Medicare managed care environment is evaluated. We close with some brief comments on how to succeed in competitive bidding for Medicare services.
Role of nitric oxide in cardiovascular disease: focus on the endothelium
Authors: Cannon Richard O 
Published: January 2020

Abstract
Nitric oxide is a soluble gas continuously synthesized by the endothelium. This substance has a wide range of biological properties that maintain vascular homeostasis, including modulation of vascular dilator tone, regulation of local cell growth, and protection of the vessel from injurious consequences of platelets and cells circulating in blood. A growing list of conditions, including those commonly associated as risk factors for atherosclerosis such as hypertension and hypercholesterolemia, are associated with diminished release of nitric oxide into the arterial wall either because of impaired synthesis or excessive oxidative degradation. Diminished nitric oxide bioactivity may cause constriction of coronary arteries during exercise or during mental stress and contribute to provocation of myocardial ischemia in patients with coronary artery disease. Additionally, diminished nitric oxide bioactivity may facilitate vascular inflammation that could lead to oxidation of lipoproteins and foam cell formation, the precursor of the atherosclerotic plaque. Numerous therapies have been investigated to assess the possibility of reversing endothelial dysfunction by enhancing the release of nitric oxide from the endothelium, either through stimulation of nitric oxide synthesis or protection of nitric oxide from oxidative inactivation and conversion to toxic molecules such as peroxynitrite. Accordingly, causal relationships between improved endothelial function and reduction in myocardial ischemia and acute coronary events can now be investigated.
Erythrocyte folate analysis: a cause for concern?
Authors: Wright Anthony J A , Finglas Paul M , Southon Susan 
Published: January 2020

AbstractNeural tube defects can be prevented by adequate intake of periconceptional folate, and inverse associations between folate status and cardiovascular disease and various cancers have been noted. Thus, there is renewed interest in the analysis of red cell folate (RCF) as an indicator of folate deficiency risk. Assessment of the assumptions that underpin RCF assays indicates that many are false. Published literature suggests that increased deoxy-hemoglobin (which can bind RCF electrostatically) yields more assayable folate, and increased oxy-hemoglobin (which cannot bind RCF) yields less assayable folate. It is argued that as deoxy-hemoglobin picks up oxygen and switches quaternary structure, any bound folate must, on purely theoretical grounds, become physically “trapped”. Venous blood taken for analysis is 65% to 75% saturated with oxygen, and pro-rata “trapping” will lead to serious underestimation of RCF. Hence, doubt is cast over the validity of all previous RCF values. Some strategies for accurately assessing RCF are suggested.
Simple method for the routine determination of betaine and N,N-dimethylglycine in blood and urine
Authors: Laryea Maurice D , Steinhagen Folkert , Pawliczek Sandra , Wendel Udo 
Published: January 2020

Abstract
A simple and convenient method using commercially available derivatization reagents is described for the measurement of betaine and N,N-dimethylglycine (DMG) in blood and urine. Precolumn derivatization of plasma or urine is performed directly in acetonitrile without extraction with p-bromophenacyl bromide and crown ether as catalyst. The p-bromophenacyl ester derivatives are then separated by high-performance liquid chromatography, using an isocratic system of acetonitrile and water containing choline. Effluent was monitored at 254 nm. The limit of detection was 5 μmol/L for betaine and 2 μmol/L for DMG. Analytical recovery was &gt;97% for both analytes. Total and within-day CVs were 2.0–4.4% and 0.9–2.2% for DMG. For betaine, the total and within-day CVs were 1.3–5.3% and 0.4–3.8%, respectively. The method is precise and cost-effective and has been used successfully to determine the concentrations of DMG and betaine in human plasma and urine.
Ligand assays: from electrophoresis to miniaturized microarrays
Authors: Ekins Roger P 
Published: January 2020

Abstract
The main developments in the “ligand assay” field in which I have been involved are traced. These include the original development of “first generation” competitive assays relying on radiolabeled analyte markers; the development of the first “second generation”, noncompetitive (ultrasensitive) methods, which rely on the use of labeled (monoclonal) antibodies and high specific activity nonisotopic labels (leading to the transformation of the immunodiagnostic field in the 1980s); and the development of the first “third generation” miniaturized, chip-based, microarray methods, which permit the simultaneous ultrasensitive measurement of many analytes in the same small sample. The latter—applicable both to immunoassay and to DNA/RNA analysis—are likely to revolutionize the diagnostic and pharmaceutical fields in the next decade.
Automated Flow Cytometry Compared with an Automated Dipstick Reader for Urinalysis
Authors: Langlois Michel R , Delanghe Joris R , Steyaert Sophia R , Everaert Karel C , De Buyzere Marc L 
Published: January 2020

Abstract
Recently, the Sysmex UF-100 flow cytometer was developed to automate urinalysis. We compared UF-100 test results with those of an automated dipstick reader. A cross-check of UF-100, dipstick, and microscopic sediment data was performed in 1001 urine samples. Good agreements (P &lt;0.001) were obtained between UF-100 and dipstick data for erythrocytes (r = 0.636) and leukocytes (r = 0.785). Even in urine with low conductivity, the UF-100 could detect lysed erythrocytes. The UF-100 bacterial count was higher among nitrite-positive urine samples (P &lt;0.0001) and was positively correlated with the UF-100 leukocyte count (r = 0.745; P &lt;0.001). In stored urine (24 h), bacterial counts increased, whereas the forward light scatter of leukocytes decreased (P &lt;0.01). Casts and yeast cells reported by the UF-100 should be confirmed by microscopic review because false positives occurred. We suggest that a computer-assisted cross-check of UF-100 and dipstick data allows a clinically acceptable sieving system to reduce the workload of microscopic sediment urinalysis.