bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comprehensive analytical strategy for mutation screening in 21-hydroxylase deficiency
Authors: Krone Nils , Roscher Adelbert Anton , Schwarz Hans Peter , Braun Andreas 
Published: January 2020

Abstract
Congenital adrenal hyperplasia (CAH) is an autosomal recessive disease with a wide range of clinical manifestations. It is most often caused by deficiency of steroid 21-hydroxylase, reflecting any of a wide range of mutations in the 21-hydroxylase (CYP21) gene. A major challenge in molecular diagnostics of CAH is the high homology between the CYP21 gene and the CYP21P pseudogene and the phenomenon of apparent gene conversion, which inactivates the functional gene. In this study we devised an improved stepwise diagnostic procedure involving nonradioactive Southern blotting and direct DNA sequencing. This strategy led to a successful elucidation of the molecular cause of the disease in 181 out of 182 unrelated alleles in a total of 91 clinically and biochemically characterized patients. We were able to identify all classical known disease-causing mutations of the 21-hydroxylase gene and a novel nonsense mutation (bp 670, A→C, Y97X). Our method also allows the reliable, secure diagnosis of the heterozygous configuration and may therefore be used for pre-, peri-, and postnatal diagnosis of CAH, even when informative data of the index patient are lacking. Furthermore, it can be used to confirm the diagnosis of CAH in newborns detected in 17-hydroxyprogesterone screening programs.
The precursor form of the human kallikrein 2, a kallikrein homologous to prostate-specific antigen, is present in human sera and is increased in prostate cancer and benign prostatic hyperplasia
Authors: Saedi Mohammad S , Hill Timothy M , Kuus-Reichel Kristine , Kumar Abhay , Payne Janice , Mikolajczyk Stephen D , Wolfert Robert L , Rittenhouse Harry G 
Published: January 2020

AbstractProstate-specific antigen (PSA, hK3) is a diagnostic marker for prostatic cancer but lacks the specificity to sufficiently distinguish between prostatic cancer and benign prostatic hyperplasia (BPH). Human glandular kallikrein 2 (hK2) has been proposed as a potential diagnostic marker for prostate cancer that could complement the current PSA test. Recently we demonstrated that proPSA is present in prostate cancer sera. This study examines the expression of prohK2 in prostate cells and its presence in human sera. Western blot analysis was used to assess prohK2 expression in the human carcinoma cell line, LNCaP. A highly specific and sensitive dual monoclonal immunoassay for prohK2 was developed and used to assess the presence of prohK2 in human sera. prohK2 was detected in the spent media of LNCaP cells. Furthermore, prohK2 was present at immunodetectable concentrations in human sera, and its concentration was increased in prostatic cancer and BPH. These results indicate for the first time that prohK2 is secreted by human prostate cells and is a major component of uncomplexed (free) hK2 in human sera. In addition, prohK2 in human sera is associated with prostate disease and thus may be a useful marker for prostatic cancer and BPH.
Urinary free deoxypyridinoline by chemiluminescence immunoassay: analytical and clinical evaluation
Authors: Rosano Thomas G , Peaston Robert T , Bone Henry G , Woitge Henning W , Francis Roger M , Seibel Markus J 
Published: January 2020

AbstractWe evaluated an automated chemiluminescence immunoassay (CLIA) developed for the measurement of urinary free deoxypyridinoline (DPD). The new DPD method by CLIA is based on the competition of DPD with particle-bound pyridinoline for a limited amount of monoclonal mouse anti-DPD antibody. Total imprecision (CV) was 3.2–9.0% at 30–270 nmol/L. Regression analysis of urinary DPD concentration (second morning-void) measured by CLIA (y) and enzyme immunoassay (EIA) for adult volunteers (n = 449) with and without bone disease revealed a best fit equation of: y = 1.08 ± 0.03x − 1.15 ± 0.98 nmol/L (r = 0.964, Sy‖x = 14 nmol/L). CLIA and EIA methods were correlated with HPLC measurement of urinary free DPD (r = 0.846 and 0.871, respectively). For healthy adults, the creatinine-normalized excretion of DPD (mean ± SD) measured by CLIA for 61 men (4.1 ± 1.2 μmol DPD/mol creatinine) and 76 premenopausal women (5.3 ± 1.8 μmol DPD/mol creatinine) did not differ significantly (P &gt;0.05) from DPD excretion measured by EIA, and both immunoassays showed a significant gender difference (P &lt;0.001) in reference intervals. In a clinical trial, DPD excretion (μmol DPD/mol creatinine) measured by CLIA differed substantially from the reference population for 54 untreated pagetic (12.7 ± 8.0 SD), 255 untreated osteoporotic (7.5 ± 4.1), 21 osteomalacic (12.4 ± 8.5), 17 primary hyperparathyroid (9.4 ± 4.4), and 14 secondary hyperparathyroid (9.2 ± 5.1) patients. Clinical sensitivities of the CLIA and EIA methods range from 38% to 80% in bone disorders and limit the use of the DPD measurement in disease detection. DPD excretion after pamidronate treatment in a subgroup of the pagetic patients fell dramatically as assessed by CLIA or EIA. We conclude that the automated CLIA method for DPD is a convenient and reliable method that may aid in the evaluation and management of bone disease and is applicable to high volume testing in the routine clinical laboratory.
Hemoglobin Rambam (β69[E13]Gly→Asp), a pitfall in the assessment of diabetic control: characterization by electrospray mass spectrometry and HPLC
Authors: Bissé E , Zorn N , Eigel A , Lizama M , Huaman-Guillen P , März W , Van Dorsselaer A , Wieland H 
Published: January 2020

AbstractHemoglobin (Hb) Rambam, or β69[E13]Gly→Asp, has been identified in a German woman also suffering from non-insulin-dependent diabetes mellitus and chronic obstructive pulmonary disease. This is the first observation of this Hb variant in a German family thus far. The detailed evaluation of its structure using electrospray mass spectrometry revealed new minor glycohemoglobin components and showed that the attachment of glucose to the β NH2 terminus occurred at an almost identical rate in both wild-type and mutant β-chains. However, the introduction of a carboxyl group at β69 seems to increase the glycation of ε-amino groups of lysine residues. The glycemic state in the propositus was well reflected by the total glycohemoglobin concentrations but not by the Hb A1C values, which did not reflect hemoglobin glycation in this patient. This case demonstrates that Hb A1C cannot be used reliably in the management of diabetic patients carrying Hb variants such as Hb Rambam. Functional studies of the whole blood of the heterozygous carrier demonstrated extremely low oxygen affinity, which may have been caused by increased 2,3-diphosphoglycerate related to chronic obstructive pulmonary disease and hyperthyroidism. None of the clinical symptoms could be directly associated to Hb Rambam.
Clinical evaluation of the Serum CrossLaps One Step ELISA, a new assay measuring the serum concentration of bone-derived degradation products of type I collagen C-telopeptides
Authors: Christgau Stephan , Rosenquist Christian , Alexandersen Peter , Bjarnason Nina Hannover , Ravn Pernille , Fledelius Christian , Herling Christian , Qvist Per , Christiansen Claus 
Published: January 2020

AbstractThe Serum CrossLapsTM One Step ELISA is a sandwich assay using two monoclonal antibodies specific for a β-aspartate form of the epitope EKAHDGGR derived from the carboxy-terminal telopeptide region of type I collagen α1-chain. Our objective was to assess the clinical value of the Serum CrossLaps assay for monitoring antiresorptive therapy in osteoporosis treatment. Samples obtained from postmenopausal women treated with different doses of cyclic or continuous hormone replacement therapy (HRT) with an estrogen analog (tibolone) or with a bisphosphonate (ibandronate) were measured in the Serum CrossLaps One Step ELISA at baseline and at various time points during therapy. The corresponding urine samples were measured in the urine CrossLapsTM ELISA and corrected for creatinine excretion. The serum CrossLaps measurements and corresponding urinary CrossLaps measurements were highly correlated (r &gt;0.8 for all studies). The serum and urine CrossLaps measurements showed a significant decrease among the women treated with clinically relevant doses of either of the antiresorptive agents. Furthermore, the annual percentage change in bone mineral density (BMD) correlated with the measured changes in CrossLaps concentration. The serum CrossLaps assay showed a specificity of 83–100% and a sensitivity of 59–83% for assessing BMD changes. The corresponding values for the creatinine-corrected urinary measurements were 83–92% specificity and 68–79% sensitivity. We conclude that performance of the convenient Serum CrossLaps One Step ELISA is at least equivalent to that of the urine text for follow up of antiresorptive treatment in osteoporosis. Further studies are needed to optimize its use in this and other clinical applications.
Lipoprotein(a) as a risk factor for ischemic heart disease: metaanalysis of prospective studies
Authors: Craig Wendy Y , Neveux Louis M , Palomaki Glenn E , Cleveland Meghan M , Haddow James E 
Published: January 2020

Abstract
Although in vitro studies support a pathophysiologic role for lipoprotein(a) [Lp(a)] in the development of atherosclerosis, and retrospective studies consistently report that there is a relationship between Lp(a) and ischemic heart disease (IHD), the conclusions drawn from prospective studies about this relationship have been inconsistent. To address this issue, we have performed a metaanalysis of data available from prospective studies. Lp(a) concentrations expressed as mass units vary markedly between studies, reflecting the need for assay standardization. In 12 of 14 prospective studies, Lp(a) concentrations are higher in subjects who later develop IHD (cases) than in those who do not (controls), although there is variation in the size of the effect. Sample storage temperature may contribute to this variability. When the studies are analyzed collectively, Lp(a) concentrations are significantly higher in cases than in controls, and the extent of the effect is similar in men and women. These findings provide evidence in support of a causal role for Lp(a) in the development of atherosclerosis. Measurement of Lp(a) may be useful to guide management of individuals with a family history of IHD or with existing disease. The separation in values between cases and controls is not, however, sufficient to allow the use of Lp(a) as a screening test in the general population.
Use of phenylalanine-to-tyrosine ratio determined by tandem mass spectrometry to improve newborn screening for phenylketonuria of early discharge specimens collected in the first 24 hours
Authors: Chace Donald H , Sherwin John E , Hillman Steven L , Lorey Fred , Cunningham George C 
Published: January 2020

AbstractWe compared the screening interpretation of fluorometric analytical results for phenylketonuria (PKU) with tandem mass spectrometry (MS/MS) in filter paper blood spots collected from newborns &lt;24 h of age. In MS/MS, both Phe and Tyr are quantified. Two hundred and eight blood spots collected from infants &lt;24 h of age were retrieved from storage from the California newborn screening program. These samples had been categorized on the basis of fluorometric analysis as initial negative, initial positive for hyperphenylalaninemia with negative determination on recall, or initial positive for hyperphenylalaninemia and confirmed on follow up as PKU or variant hyperphenylalaninemia. The retrieved samples were analyzed in a blinded fashion using MS/MS. Correlation analysis of fluorometry vs MS/MS for Phe concentration was high, with a Pearson correlation coefficient of 0.817. When 180 μmol/L was used as the cutoff Phe concentration for MS/MS and 258 μmol/L was used as the cutoff for fluorometry, all infants with confirmed classical PKU and variant hyperphenylalaninemia were detected. MS/MS analysis reduced the number of false-positive results from 91 to 3. Simultaneous quantification of Phe and Tyr by MS/MS with the use of a cutoff Phe/Tyr molar ratio of 2.5 further reduced the number of false positives to 1. Samples from affected infants showed a discernible trend of increasing Phe concentration and Phe/Tyr molar ratio with age of collection. These results demonstrate the utility of MS/MS in the routine PKU screening of early-discharge newborns. MS/MS reduces the false-positive rate of fluorometric screening almost 100-fold because of the improved accuracy and precision of Phe measurement and simultaneous confirmation with the Phe/Tyr molar ratio. In addition to the detection of PKU, MS/MS can also detect other aminoacidopathies and disorders of fatty acid and organic acid metabolism with lower false-positive rates than other methods currently used in newborn screening programs.
Characterization of frequent polymorphisms in intron 2 of CYP21: application to analysis of segregation of CYP21 alleles
Authors: Killeen Anthony A , Jiddou Renée R , Sane Kumud S 
Published: January 2020

AbstractThe gene encoding adrenal steroid 21-hydroxylase, CYP21, is located in the MHC class III region. Most cases of congenital adrenal hyperplasia (CAH) are caused by mutations in this gene, and most mutations appear to arise from gene conversion-like events involving the transfer of deleterious sequences from the pseudogene, CYP21P, which is located within 30 kb of CYP21. Approximately 20–30% of mutations are caused by deletions of CYP21. The second intron of CYP21 is polymorphic, and several base substitutions that include nt395, nt453, and nt601 have been reported; however, the frequencies of these polymorphisms are unknown. Using a combination of cleavase fragment length polymorphism analysis and direct sequencing, we examined the sequence of intron 2 in seven wild-type CYP21 genes and determined the frequency of polymorphisms at nt395, nt453, and nt601 in 48 chromosomes from the parental generation of Centre d’Étude du Polymorphisme Humain families. The observed frequencies of bases at these positions were as follows: 395C, 0.17; 395T, 0.83; 453C, 0.71; 453T, 0.29; 601A, 0.1; and 601C, 0.9. Using a PCR/restriction digestion approach to examine these intragenic markers, we could follow the segregation of alleles in informative families with 21-hydroxylase deficiency and identify deletions of CYP21. We emphasize that this method should be used in conjunction with other molecular genetic techniques for diagnosis of CAH. In addition to their potential use in families with CAH, these markers may be of use in genetic studies of the MHC in humans.
Quantitative reverse transcription-PCR assay of the RNA component of human telomerase using the TaqMan fluorogenic detection system
Authors: Yajima Tomomi , Yagihashi Atsuhito , Kameshima Hidekazu , Kobayashi Daisuke , Furuya Daisuke , Hirata Koichi , Watanabe Naoki 
Published: January 2020

AbstractWe established the validity of a quantitative reverse transcription (RT)-PCR assay for the RNA component of human telomerase (hTR), using the TaqMan fluorogenic detection system. Using this assay, we quantified hTR expression in two human pancreatic cancer cell lines, ASPC-1 and MIAPaCa-2. Our results indicated that hTR expression in MIAPaCa-2 was 1.99-fold higher than that in ASPC-1 cells. This TaqMan RT-PCR assay appears to be useful in determining the amount of hTR in clinical specimens.
Routine analysis of plasma busulfan by gas chromatography–mass fragmentography
Authors: Lai Wai-Kai , Pang Chi-Pui , Law Lap-Kay , Wong Raymond , Li Chi-Kong , Yuen Patrick Man-Pan 
Published: January 2020

Abstract
Busulfan (BU) is a widely used alkylating agent for antineoplastic therapy and marrow ablation in preparation for bone marrow transplantation (BMT). High-dose BU often leads to successful preparation and low relapse but is associated with veno-occlusive disease of liver. We established a protocol to determine postdosage plasma BU concentrations by gas chromatography–mass fragmentography in an attempt to relate clinical outcome to plasma BU concentrations. We used nonisotopic pusulfan as the internal standard. After extraction into ethyl acetate, BU and pusulfan were iodinated into 1,4-diiodobutane and 1,5-diiodopentane, respectively. Gas chromatography–mass spectrometry (GC–MS) analysis was carried out on an Hewlett–Packard (HP) 5890II gas chromatograph with a 30-m 100% methyl silicon narrow bore, fused-silica capillary column interfaced with an HP 5970A mass spectrometer. Helium was the carrier gas. The sample molecules were identified by total ion monitoring and quantified by selective ion monitoring of m/z 183 and 197. The calibration curve was linear to 4 mg/L. The limit of quantification was 0.04 mg/L, and the analytical recovery was ∼97%. The within-day and between-day imprecision (CV) was &lt;6% and 9%, respectively. In a preliminary study of 12 children, the BU areas under the BU-time curve were 616–949 μmol · min/L after the first dose and 793-1143 μmol · min/L after the fifth dose. We conclude that the GC–MS procedure is suitable for routine analysis of plasma BU.
Increased concentrations of prostate-specific antigen in maternal serum from pregnancies affected by fetal Down syndrome
Authors: Lambert-Messerlian Geralyn M , Canick Jacob A , Melegos Dimitrios N , Diamandis Eleftherios P 
Published: January 2020

Abstract
Down syndrome is one of the most common causes of mental retardation in the industrialized world. Prenatal serum screening to identify mothers at risk of carrying a fetus affected with Down syndrome is presently part of routine obstetrical care. Prostate-specific antigen (PSA) concentration was measured in stored second-trimester maternal serum samples from 19 pregnancies affected with fetal Down syndrome and in 95 samples from unaffected pregnancies, with each case matched to five controls for gestational age and duration of frozen sample storage. Concentrations of PSA in Down syndrome pregnancy were significantly higher (case median = 2.28 multiples of the median; P = 0.02) than in unaffected pregnancy. PSA concentrations were not significantly correlated with the current serum screening analytes, alpha-fetoprotein, unconjugated estriol, or human chorionic gonadotropin in either cases or controls. The increased maternal serum PSA concentrations in Down syndrome pregnancy and their relative independence from other markers suggest the possible utility of PSA as a prenatal screening marker for fetal Down syndrome.
Development of FlexSure® HP—an immunochromatographic method to detect antibodies against Helicobacter pylori
Authors: Schrier Wayne H , Schoengold Ronald J , Baker Josefina T , Norell Joyce L , Jaseph Corey L , Okin Yelena , Doe Jeam Y , Chandler Howard 
Published: January 2020

Abstract
We describe a solid-phase immunochromatographic serologic test, FlexSure® HP, to detect IgG antibodies against Helicobacter pylori. H. pylori colonize the stomach and proximal duodenum, cause ulcer disease and mucosa-associated lymphoid tissue lymphoma, and have a role in the development of other disorders, including gastric adenocarcinoma. FlexSure HP consists of a test strip, conjugate pad, and absorbent pad, in a novel reverse-flow chromatography format. In these studies, FlexSure HP was demonstrated to be specific for IgG antibodies against H. pylori. The reactive cutoff of the test was consistent with [13C]urea breath test and commercially available ELISAs. FlexSure HP had 94% sensitivity, 88% specificity, and 91% accuracy relative to [13C]urea breath test; and 95% sensitivity, 94% specificity, and 95% overall agreement relative to high-molecular-mass cell-associated protein enzyme immunoassay (HM-CAP EIA). FlexSure HP is a simple-to-perform, visually read test requiring no specialized training, equipment, or instrumentation, and yields rapid, accurate, qualitative results.
Multivariate discrimination for phenylketonuria (PKU) and non-PKU hyperphenylalaninemia after analysis of newborns’ dried blood-spot specimens for six amino acids by ion-exchange chromatography
Authors: Reilly Andrew A , Bellisario Ronald , Pass Kenneth A 
Published: January 2020

AbstractIon-exchange HPLC was developed for testing dried blood-spot specimens from newborns. The method is suitable for quantitative confirmatory testing of abnormal specimens detected in the New York State Newborn Screening Program. Positive specimens were initially identified among all New York State newborns with semiquantitative bacterial inhibition assays (BIA) for aminoacidopathies, including phenylketonuria (PKU) and non-PKU hyperphenylalaninemia (HP), maple syrup urine disease, and homocystinuria. A selection of 1346 specimens from routine BIA screening, including 131 newborns with PKU or persistent HP, were tested by HPLC. Of 179 BIA results that were falsely positive, 98 (55%) were also falsely positive by HPLC in which the Phe/Tyr ratio was the discriminator and the threshold was set to attain 100% sensitivity. Investigation of three multivariate discriminatory methods revealed that linear discriminant analysis excluded all but 35 (20%) of the BIA false-positives.
Plasma lipoprotein profiles change significantly during cardiac catheterization
Authors: Miida Takashi , Otsuka Hideaki , Tsuchiya Atsushi , Okada Masahiko 
Published: January 2020

AbstractMost patients in acute myocardial infarction (AMI) undergo emergent coronary angiography (CAG). However, when to analyze lipoprotein profiles in AMI is not clear. To determine whether lipoprotein profiles change during catheterization, we measured serum lipid and apolipoprotein concentrations in 65 patients (51 men and 14 women) before and after catheterization. Heparin was injected at 50 units/kg for CAG and 200 units/kg for percutaneous transluminal coronary angioplasty (PTCA). We found that cholesterol and triglyceride decreased by 9.4% (P &lt;0.001) and 53.1% (P &lt;0.001), respectively, after catheterization. Apolipoproteins also decreased significantly. Variables decreased two to five times more after PTCA than after CAG. Lipoprotein lipase mass was higher after PTCA (267.8 ± 135.3 μg/L) than after CAG (93.3 ± 48.4 μg/L; P &lt;0.05). In conclusion, lipoprotein profiles change during catheterization. We recommend avoiding analysis of lipoprotein profiles after emergent CAG in AMI.
Homogeneous assay for measuring low-density lipoprotein cholesterol in serum with triblock copolymer and α-cyclodextrin sulfate
Authors: Sugiuchi Hiroyuki , Irie Tetsumi , Uji Yoshinori , Ueno Tomohiro , Chaen Toshiko , Uekama Kaneto , Okabe Hiroaki 
Published: January 2020

AbstractWe have developed a fully automated method for measuring LDL-cholesterol (LDL-C) in human serum without the need for prior separation, using a nonionic surfactant, polyoxyethylene–polyoxypropylene block copolyether (POE-POP), and a sodium salt of sulfated cyclic maltohexaose, α-cyclodextrin sulfate. Of the surfactants tested, POE-POP with a higher molecular mass of the POP block and a greater hydrophobicity reduced the reactivity of cholesterol in lipoprotein fractions; the reactivity in descending order was LDL ≫ VLDL &gt; chylomicron ≈ HDL. Gel filtration chromatographic studies revealed that POE-POP removed lipids selectively from the LDL fraction and allowed them to participate in the cholesterol esterase–cholesterol oxidase coupling reaction system. By contrast, α-cyclodextrin sulfate reduced the reactivity of cholesterol, especially in chylomicrons and VLDL. A combination of POE-POP with α-cyclodextrin sulfate provided the required selectivity for the determination of LDL-C in serum in the presence of magnesium ions and a small amount of dextran sulfate without precipitating lipoprotein aggregates. There was a good correlation between the results of LDL-C assayed by the proposed method and the beta-quantification reference method involving 161 sera with triglyceride concentrations ranging from 0.3 to 22.6 mmol/L.