bluuebunny/crossref_metadata_2025_split huggingface dataset:
Atherogenic nature of triglycerides, postprandial lipidemia, and triglyceride-rich remnant lipoproteins
Authors: Zilversmit D B 
Published: January 2020

Abstract
In addition to low-density lipoproteins, plasma chylomicrons and very-low-density lipoproteins (VLDL) contribute to atherogenesis. When triglyceride-rich particles bind to arterial endothelium and to deendothelialized areas, locally present lipoprotein lipase initiates triglyceride hydrolysis and decreases the size of the adhering particles. Additional changes in composition are brought about by the exchange of lipids between chylomicron/VLDL remnants and the cholesteryl ester-rich low- and high-density lipoproteins. These exchanges are mediated by lipid transfer proteins in plasma. Animal studies with doubly labeled lipoproteins show that the size of lipoprotein particles determines their rate of entering the artery and contributes to the formation of lesions. This model supports epidemiologic studies that have identified plasma triglycerides as a risk factor for atherogenesis. The model for a causal role of pre- and postprandial triglyceride-rich lipoproteins in atherogenesis suggests that measuring them may improve the assessment of cardiovascular risk factors.
Prostate-specific antigen in milk of lactating women
Authors: Yu H , Diamandis E P 
Published: January 2020

Abstract
Prostate-specific antigen (PSA) is believed to be a highly specific marker for normal and cancerous prostatic tissue. We recently found that 30-40% of breast tumors produce PSA. Other data from our group suggest that normal breast can also produce PSA under conditions of stimulation by steroid hormones. In addition, we detected PSA in amniotic fluid. Here we report the presence of PSA in breast milk of lactating women. PSA concentrations in breast milk were quite variable, ranging from &lt; 0.01 microgram/L in 4 of 38 milks to 350 micrograms/L; the median was 0.47 microgram/L. PSA concentration in breast milk was not correlated with mother's age or the sex of the newborn. It did tend to decrease with increasing time postdelivery, but was still detectable 2 weeks postdelivery. PSA in milk was equally measurable by a highly sensitive PSA assay based on time-resolved fluorometry and by the IMx automated PSA method. As confirmed by Western blot analysis, PSA in milk was present predominantly in its 33-kDa form; the PSA-alpha 1-antichymotrypsin complex (100 kDa) was also present but its concentration was &lt; 25% of total PSA. We conclude that the female breast can produce PSA and that PSA is secreted into the milk during lactation; however, the biological role of PSA in milk is unknown. These and other data presented by our group suggest that PSA, a serine protease, may play a role in control of growth in mammary and other tissues through regulation of growth factors, cytokines, and growth-factor-binding proteins.
A molecular protocol for diagnosing myotonic dystrophy
Authors: Guida M , Marger R S , Papp A C , Snyder P J , Sedra M S , Kissel J T , Mendell J R , Prior T W 
Published: January 2020

Abstract
Myotonic dystrophy (DM) is an autosomal dominant genetic disease caused by an unstable CTG repeat sequence in the 3' untranslated region of the myotonin protein kinase gene. The CTG repeat is present 5-30 times in the normal population, whereas DM patients have CTG expansions of 50 to several thousand repeats. The age of onset of the disorder and the severity of the phenotype is roughly correlated with the size of the CTG expansion. We developed a molecular protocol for the diagnosis of DM based on an initial polymerase chain reaction screen to detect normal-sized alleles and small expansions, followed by an improved Southern protocol to detect larger expansions.
Apolipoprotein AI, AII, and AIV isoforms in plasma determined by automated isoelectric focusing with PhastSystem and immunofixation
Authors: Schaefer J R , Hackler R , Brand S , Schwarz S , Kleine T O , Steinmetz A 
Published: January 2020

Abstract
Distinct genetic variants of apolipoprotein (apo) AI have been shown to influence concentrations of high-density lipoprotein (HDL) cholesterol. The genetic polymorphism of apo AIV may modulate HDL-cholesterol, plasma triglycerides, and lipoprotein(a) concentrations. There is evidence for an antagonizing role of apo AII in reverse cholesterol transport. Since genetic polymorphisms and variants of these apolipoproteins are detectable by isoelectric focusing (IEF), we developed a rapid and easy automated method for IEF analysis of apos AI, AII, and AIV on self-made or commercially available gels, using the PhastSystem. Diluted plasma or serum samples (1 microL) are applied automatically onto the gel and IEF is carried out for 35-45 min. Afterwards, the apo A bands are precipitated by specific polyclonal antibodies and visualized by automated silver staining. This rapid procedure is suitable as a routine or screening method for IEF analysis of these major HDL apolipoproteins.
Continuous-flow assay with immobilized enzymes for determining of inorganic phosphate in serum
Authors: Luque de Castro M D , Quiles R , Fernández-Romero J M , Fernández E 
Published: January 2020

Abstract
An automated method for the determination of inorganic phosphate based on flow-injection analysis and on the use of immobilized enzymes is reported. The method features a linear range between 0.1 and 20 mumol/L with a CV &lt; 2.1% and 3.4% for the within-run and between-run studies, respectively, and a sampling throughput of 40 h-1. The sensitivity of the method makes a 1:250 dilution of the serum samples feasible, thus making undetectable the interferences from analytes commonly present in serum. The method shows an excellent correlation with conventional automated analyzers based on the same enzymatic reaction (Hitachi, r = 0.988) but with the catalyst in solution, and with the Kodak Ektachem method (r = 0.974) based on the use of dry reagents and formation of the phosphomolybdo heteropolyacid.
Highly sensitive and specific HPLC with fluorometric detection for determination of plasma epinephrine and norepinephrine applied to kinetic studies in humans
Authors: Willemsen J J , Ross H A , Jacobs M C , Lenders J W , Thien T , Swinkels L M , Benraad T J 
Published: January 2020

Abstract
An HPLC separation method combined with fluorometric detection was extended to enable simultaneous assessment of plasma 3H-labeled and endogenous epinephrine (E) and norepinephrine (NE). Forearm fractional extraction (FFE) of 3H-labeled E and NE and of endogenous E was measured in 40 healthy volunteers who were receiving a continuous infusion of 3H-labeled E and NE. Concentrations of arterial and venous E were 26.8 +/- 1.95 (mean +/- SE) and 6.8 +/- 0.75 ng/L, respectively. Arterial and venous NE and dopamine (DA) were also measured, with respective values of 140.7 +/- 8.5 and 192.1 +/- 15.1 for NE, and 13.1 +/- 0.78 and 11.3 +/- 0.70 ng/L for DA. The FFE of 3H-labeled E was slightly but significantly higher (0.790 +/- 0.016) than the that of either 3H-labeled NE or endogenous E (0.748 +/- 0.0146 and 0.745 +/- 0.0185, respectively; P &lt; 0.001), the correlations being highly significant (r = 0.80, P &lt; 0.001) in both cases. The small difference between the FFE of E and of 3H-labeled E allows the calculation of the apparent spillover of E. However, this spillover was negligible compared with forearm NE spillover (0.0112 +/- 0.0031 vs 1.369 +/- 0.128 ng/L per minute. The high sensitivity of this measurement of venous E widens the possibilities for studying E kinetics under physiological conditions.
Subclass typing of IgG paraproteins by immunofixation electrophoresis
Authors: Klouche M , Bradwell A R , Wilhelm D , Kirchner H 
Published: January 2020

Abstract
We present a simple method for subclass typing of IgG paraproteins, with which we have demonstrated a large number of paraproteins that were undetected by conventional immunofixation techniques. The types and distribution of IgG subclass paraproteins were analyzed in 92 human sera in which IgG paraproteins had been demonstrated. The IgG subclass paraproteins were separated by agarose gel electrophoresis rapidly and simply and then typed with the use of sheep anti-human monospecific IgG1-IgG4 antibodies. In 24 of the sera analyzed, IgG subclass typing revealed 25 additional monoclonal bands that were not detected by conventional immunofixation electrophoresis with anti-IgG antisera. Most of these belonged to a different subclass type. The overall subclass frequencies were 68% IgG1, 13% IgG2, 16% IgG3, and 3% IgG4. The distribution of paraprotein subclasses, however, was different in monoclonal gammopathies of undetermined significance in which more IgG3 was shown, whereas in non-Hodgkin lymphomas the number of IgG2 paraproteins was greater than expected; this finding may have diagnostic and prognostic significance.
Generation and characterization of monoclonal antibodies to human type-5 tartrate-resistant acid phosphatase: development of a specific immunoassay of the isoenzyme in serum
Authors: Chamberlain P , Compston J , Cox T M , Hayman A R , Imrie R C , Reynolds K , Holmes S D 
Published: January 2020

Abstract
We have characterized four monoclonal antibodies (mAbs) to the purple ("tartrate-resistant," band 5) acid phosphatase of the human osteoclast (TRAP) and used these to develop a specific serum immunoassay. All four mAbs are of high affinity (Ka = 1-5 x 10(8) L/mol) with a very fast Kassoc (0.2-2.0 x 10(5) L mol-1 s-1) and a moderate Kdissoc (1-3 x 10(-3) s). Two of the mAbs were selected to develop a time-resolved fluorescence immunoassay to measure serum concentrations of TRAP. The mean serum immunoreactive TRAP in a group of healthy premenopausal women and men was 3.7 +/- 1.8 micrograms/L (mean +/- SD) and 3.5 +/- 1.6 micrograms/L, respectively. Significantly higher concentrations of TRAP were found in postmenopausal women (6.3 +/- 2.3 micrograms/L) and in eight patients with Gaucher disease (19.3 +/- 4.7 micrograms/L). Further studies are required to investigate the value of serum TRAP as a marker of bone resorption.
Diagnosis of premature rupture of membranes with an improved alpha-fetoprotein monoclonal antibody kit
Authors: Kishida T , Hirao A , Matsuura T , Katamine T , Yamada H , Sagawa T , Fujimoto S 
Published: January 2020

Abstract
We developed a new kit for detecting alpha-fetoprotein (AFP) in leaked amniotic fluid (Eur J Obstet Gynecol Reprod Biol 1995;58:67-72). Later, we developed an improved AFP kit utilizing the same AFP monoclonal antibody. We compared this improved AFP test with the nitrazine test for 137 patients. The nitrazine test correctly diagnosed 62.1% of the cases, but the improved AFP kit diagnosed 98.0% for &lt; 37 weeks of gestation (P &lt; 0.001). The nitrazine test showed a specificity of 58.3%, whereas the AFP kit showed a 100% rate for detecting &gt; or = 37 weeks of gestation (P &lt; 0.01). The reaction time with the AFP kit is 90 s. This study has confirmed a high clinical efficacy of the improved AFP test kit as a method of diagnosis of premature rupture of fetal membranes.
Citrate in urine determined with a new citrate lyase method
Authors: Petrarulo M , Facchini P , Cerelli E , Marangella M , Linari F 
Published: January 2020

Abstract
An enzyme-spectrophotometric method to determine citrate in biological fluids is proposed, based on citrate lyase-catalyzed and phenylhydrazine reactions. The enzyme converts citrate into oxaloacetate, which, in the presence of phenylhydrazine, is transformed into the corresponding phenylhydrazone. The ultraviolet-absorbing product is determined by absorbance measurement at 330 nm. The method is more precise and twice as sensitive as the traditional citrate lyase method and, because it does not require the use of additional enzymes and coenzymes, is cheaper and simpler. Mean analytical recovery of citrate averaged 100.7% +/- 2.2%, imprecision (CV) of the assay for citrate at 0.96 mmol/L (urine) was 2.0%, and the lower limit of quantification was 0.08 mmol/L. Results correlated well with those by both ion-chromatographic and traditional citrate lyase methods.
Reliability of salivary testosterone measurements: a multicenter evaluation
Authors: Dabbs J M , Campbell B C , Gladue B A , Midgley A R , Navarro M A , Read G F , Susman E J , Swinkels L M , Worthman C M 
Published: January 2020

Abstract
The reliability of salivary testosterone assays was evaluated by nine laboratories in four countries. Each laboratory used its own RIA procedures to assay samples from a set of 100 male and 100 female subjects. Agreement among the laboratories on mean scores was within the range reported by Read (Ann N Y Acad Sci 1993; 694: 161-76). Overall agreement on individual scores, as indicated by the intraclass correlation coefficient computed within subjects across laboratories, was r = 0.87 for men and r = 0.78 for women. Mean agreement between each laboratory and the combined set of all other laboratories (via Fisher's Z-transformation) was r = 0.61 for men and r = 0.58 for women. We take these latter values to be the best estimates of the average reliability of laboratories in their ordering of individual samples.
Analyzer-dependent differences in results for ionized calcium, ionized magnesium, sodium, and pH
Authors: Hristova E N , Cecco S , Niemela J E , Rehak N N , Elin R J 
Published: January 2020

Abstract
We compared two ion-selective analyzers (AVL 988-4 and NOVA CRT) for determining ionized calcium (iCa2+), ionized magnesium (iMg2+), sodium (Na+), and pH in serum specimens from healthy and diseased individuals. For assays of three levels of protein-based control materials, total imprecision (CV) was &lt; 3% for all analytes except iMg2+ (&lt; or = 6.5% on NOVA, and &lt; or = 4.9% on AVL). We found a significant difference between the analyzers (P &lt; 0.001) for the mean iMg2+ concentration in patients but no significant correlation (r = 0.253) between the analyzers for iMg2+ in specimens from healthy volunteers, even though the mean iMg2+ concentration did not differ significantly between these groups. The reference interval (central 95 percentiles) for iMg2+ with AVL (0.44-0.60 mmol/L) was contained within that of NOVA (0.39-0.64 mmol/L). The AVL gave higher values for iCa2+ (P &lt; 0.001) and lower values for pH (P &lt; 0.001) in specimens from normal volunteers and patients. The mean value for Na+ in patients' samples was significantly higher by the NOVA (P &lt; 0.01) than by the AVL analyzer. Thus, we found significant differences between these two analyzers for all four analytes.
Calcium ion binding to clinically relevant chemical modifications of human serum albumin
Authors: Vorum H , Fisker K , Otagiri M , Pedersen A O , Kragh-Hansen U 
Published: January 2020

Abstract
Calcium binding to glycated, penicilloylated, acetylated, and normal defatted human serum albumin as well as to mercapt- and nonmercaptalbumin was studied by equilibrium dialysis of radioactive Ca2+. Binding was quantified by five Scatchard constants [ni = 1, (i = 1-4) and n5 = 10]. Glycation resulted in increased k1- and k2-values and unchanged k3-k5-values, whereas penicilloylation increased all five association constants. The increments were greater the more pronounced the modification, and the enhancements caused by penicilloylation were, for the same degree of modification, greater than those produced by glycation. In contrast, acetylation by acetylsalicylate did not affect calcium binding. Likewise, binding to mercapt- and nonmercaptalbumin was the same, a finding showing that the thiol group of cysteine 34 is not important for calcium binding. D-Glucose and penicillin G are known to react with lysine residues of albumin, and the enhancement of binding resulting from glycation or penicilloylation is probably brought about by unspecific electrostatic effects, possibly supplemented by conformational changes of the protein molecule. The relative importance of the three domains of human serum albumin for calcium binding is discussed.
Variation in measurement of prostate-specific antigen: importance of method and lot variability
Authors: Wener M H , Daum P R , Brawer M K 
Published: January 2020

Abstract
Equivalence between Hybritech Tandem and Abbott IMx PSA methods have been reported by some but not all previous investigators. To determine reasons for these differing conclusions, we measured serum PSA with three different lots each of IMx and Tandem-E kits. Overall, mean IMx results were significantly lower than Tandem-E results; however, for selected sera, the IMx results were consistently higher than the Tandem-E results. Lot-to-lot differences for the IMx method were significantly greater than those with the Tandem-E method. Most IMx/Tandem-E lot-to-lot comparisons had linear regression slopes that differed significantly from 1.0, but some did not. Conclusions concerning the equivalence of the IMx and the Tandem-E methods can be influenced both by variations in the proportions of free PSA in sera in tested populations and by lot-to-lot differences in the IMx method.
Enzymatic method for determining ketone body ratio in arterial blood
Authors: Uno S , Takehiro O , Tabata R , Ozawa K 
Published: January 2020

Abstract
We have developed a new, sensitive, and rapid method for measuring the ketone body concentration in arterial blood and determining the arterial blood ketone body ratio. The procedure involves the sequential use of the enzymes 3-hydroxybutyrate dehydrogenase (3-HBDH; EC 1.1.1.30) and NADH oxidase, followed by a color-generating reaction with the hydrogen peroxide produced by the oxidase reaction. The amount of oxidized chromogen produced is proportional to the 3-hydroxybutyrate (3-HBA) concentration. The acetoacetate (AcAc) concentration is obtained after complete conversion of the AcAc to 3-HBA, in the presence of 3-HBDH. The total 3-HBA concentration is measured and then subtracted from the total ketone body concentration to give the AcAc concentration. This procedure may be applied to plasma samples and the absorbance change measured with an automated chemistry analyzer. Ketone body concentration may be determined over the range 0 to 400 mumol/L. The analysis takes approximately 12 min and requires only 30 microL of plasma.
Lipid peroxidation and antioxidants as biomarkers of tissue damage
Authors: Gutteridge J M 
Published: January 2020

Abstract
Disturbance of the balance between the production of reactive oxygen species such as superoxide; hydrogen peroxide; hypochlorous acid; hydroxyl, alkoxyl, and peroxyl radicals; and antioxidant defenses against them produces oxidative stress, which amplifies tissue damage by releasing prooxidative forms of reactive iron that are able to drive Fenton chemistry and lipid peroxidation and by eroding away protective sacrificial antioxidants. The body has a hierarchy of defense strategies to deal with oxidative stress within different cellular compartments, and superimposed on these are gene-regulated defenses involving the heat-shock and oxidant stress proteins.
Induced gene transcription: implications for biomarkers
Authors: Sewall C H , Bell D A , Clark G C , Tritscher A M , Tully D B , Vanden Heuvel J , Lucier G W 
Published: January 2020

Abstract
Numerous xenobiotics regulate cellular functions by altering transcription of target genes. Use of sensitive and specific biomarkers based on gene transcript levels may help clarify the shape of the dose-response curve in the low-dose region associated with human exposures to environmental concentrations of chemicals. We have quantified gene transcription induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin in both animal models and humans with the use of Northern analysis and PCR-based methods. In addition, we describe a rapid and sensitive in vitro assay that we have used to screen chemicals and biological samples for their ability to alter gene transcription. Whereas some of the endpoints in our studies such as cytochrome P-450 1A1 are predictive indicators of exposure and dose, other gene responses such as growth factors are more complex and represent a critical event, progression, or adaptation to a pathological alteration. In conclusion, measurement of toxicant-induced gene transcription will contribute to the usefulness of biomarkers in addressing issues of human health and environmentally induced disease.
Markers of neurotoxicity: from behavior to autoantibodies against brain proteins
Authors: Evans H L 
Published: January 2020

Abstract
Evidence of potentially neurotoxic exposures may be obtained in peripheral indicator media, but molecular or cellular evidence of neurotoxic effects has not been as readily available, primarily because the nervous system of living humans is beyond the reach of direct measures. Although there is limited evidence that molecular changes in the blood can provide information about neurotoxicity, several new approaches are being investigated. One is that the immune system may preserve evidence of damage to the nervous system. Debris from damaged cells in the nervous system may present as antigens, giving rise to autoantibodies, which may be detectable in blood for a long time after injury. Progress will depend on more control experiments and clarification of confounding variables. Validation of new molecular markers must go hand in hand with documentation of impaired function, most commonly measured as behavioral or neurophysiological changes. These noninvasive markers will be measured with greater sensitivity and precision, thanks to innovative computer technology. The practical advantages of the new markers may be as important as their contribution to our understanding of the mechanisms by which the nervous system defends against chemical insult.
Manifestations of chemically induced liver damage
Authors: Batt A M , Ferrari L 
Published: January 2020

Abstract
Possible liver damage induced by chemicals or drugs must be detected early during drug development or industrial exposure, although damage is still difficult to predict, especially when immunotoxicity is involved. Liver toxicity may result from cytolysis, steatosis, cholestasis, phospholipidosis, or vascular lesions, most the outcome of a disadvantageous balance between chemicals or metabolites vs protective mechanisms, resulting from chemical dosage, genetic factors, or the immunoallergic status of the patient. Drug metabolism, lipid peroxidation, and thiol oxidation are frequently involved in liver toxicities. Classical guidelines in toxicology propose many methods for liver toxicity assessment: histology; chemical changes in hepatic tissue (lipids, glutathione, enzymes); physiological changes in biosynthesis (proteins, glycoproteins); excretion function (fructose); drug metabolism; and concentrations of related enzymes (alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and gamma-glutamyltransferase) in blood. In vitro studies in human or animal hepatocytes or tumor-derived cell lines are useful in detecting hepatocellular lesions by cell viability, glutathione concentration, amount of lactate dehydrogenase released, cellular ATP, morphology (blebs), and drug metabolism.