bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reassessment of the two‐site enzyme immunoassay for human epidermal growth factor (hegf) and measurement of immunoreactive hegf in human sera and urine
Authors: Takei Yoshifumi , Ezawa Hisayo , Hayashi Kyozo , Kurobe Masayuki 
Published: March 2007

AbstractWe reassessed the enzyme immunoassay (EIA) system for hEGF previously developed by our laboratory (Clin Chim Acta 156:51–60, 1985), since it appeared that the reported EIA system detected not only hEGF but also pS2 protein owing to minor contamination by pS2 protein in the hEGF sample used for immunization. In this study, we purified the hEGF sample using Benzamidine‐Sepharose 6B column chromatography as a critical step for purification and newly developed an EIA system with specificity for hEGF. We also measured the hEGF level in serum, plasma, and urine from normal subjects by our new EIA system and found that the values measured by the previous system were 1.2–5.8‐fold higher than the new system values. These results suggest that the previous system detected “hEGF” in excess owing to the nonspecificity of the antibody used. We investigated the molecular nature of immunoreactive hEGF detected in serum using our new system and confirmed that considerable amounts of immunoreactive hEGF exist as a high molecular weight form through S‐S linkage with some macromolecule(s) in human blood as reported previously (Biochem Int 12:677–683, 1986).©1995 wiley‐Liss, inc.
Acid citrate dextrose (acd) formula a as a new anticoagulant in the measurement of in vitro platelet aggregation
Authors: Pignatelli Pasquale , Pulcinelli Fabio M. , Ciatti Filippo , Pesciotti Marzia , Sebastiani Silvia , Ferroni Patrizia , Gazzaniga Pier Paolo 
Published: March 2007

AbstractTo evaluate whether the use of ACD Formula A may affect in vitro platelet function, blood samples were obtained from 21 healthy blood donors and anticoagulated in ACD (acid‐citrate dextrose, NIH Formula A), Na citrate 3.8%, and K3EDTA. Platelet count, mean platelet volume, and in vitro platelet aggregation were evaluated on each sample. No significant difference was observed in platelet count and mean platelet volume among the different samples. Conversely, the ACD treated platelets showed a higher reactivity to the agonists as demonstrated by a significant increase of the maximum percentages of aggregation induced by ADP, epinephrine, and collagen, as well as a significant decrease of secondary aggregation thresholds to ADP and epinephrine. In conclusion, it may be speculated that ACD Formula A is capable of better maintaining the intraplatelet signal transduction mechanisms during PRP preparation, thus improving the overall responsiveness of platelets.©1995 wiley‐Liss, inc.
Identification and characterization of c‐erbb‐2 proteins in serum, breast tumor tissue, and sk‐br‐3 cell line
Authors: Wu James T. , Zhang Ping , Astill Mark E. , Lyons Bradley W. , Wu Lily H. 
Published: March 2007

AbstractWe have identified and characterized c‐erbB‐2 protein molecules in sera from patients with carcinomas, in both cytosol and cell membrane extract from breast tumor tissue and in both the culture medium and cell extract of the SK‐BR‐3 cell line. These proteins were characterized by various chromatographic techniques and identified by the use of two immunoassays; one measures both the c‐erbB‐2 oncoprotein (p 185) and its ectodomain (p 120), and the other in‐house assay reacts specifically for p 185. We found that the majority of the immunoreactivity detected in the serum, tumor tissue cytosol, and conditioned cell medium was derived from the ectodomain molecule (p 120) of the c‐erbB‐2 oncoprotein (p 185), whereas only p185 was detected in the extracts from cell membrane of both tumor tissue and the SK‐BR‐3 cell line. The ectodomain molecules (p 120) found in the serum, cytosol, and cell medium were very similar in terms of molecular size and charge property. The molecular weight was determined to be 120 kDa by the size exclusion HPLC method. Both p 120 and p 185 are glycoproteins and were retained by the ConA Sepharose column. Both molecules are also heterogeneous in charge and multiple peaks could be identified in the elution profiles of anion exchange HPLC and chromatofocusing. This information should not only facilitate the isolation of these molecules, but also improve preparation of specific antibodies, preparation of calibrators, and development of improved assays for these proteins.©1995 wiley‐Liss, inc.
Measurement of c‐erbb‐2 proteins in sera from patients with carcinomas and in breast tumor tissue cytosols: Correlation with serum tumor markers and membrane‐bound oncoprotein
Authors: Wu James T. , Astill Mark E. , Gagon Shane D. , Bryson Lynn 
Published: March 2007

AbstractUsing a commercial kit with antibodies against the ectodomain of c‐erbB‐2 protein, we detected c‐erbB‐2 immunoreactivity in human serum. We found that the percentages of patients with elevated serum c‐erbB‐2 immunoreactivities were 35, 21, and 9% in breast, prostate, and ovarian carcinoma, respectively. The majority of the elevated immunoreactivities were associated with sera containing highly elevated tumor markers with the highest in breast carcinoma (35%) and lowest in ovarian cancer (9%). Excellent correlations were also observed between the serum levels of c‐erbB‐2 immunoreactivity and the dominant tumor markers in serial specimens from individual cancer patients. We could also detect the c‐erbB‐2 immunoreactivity in the cytosols prepared from the breast tumor tissue for estrogen and progesterone receptor (ER&PgR) measurements using the same commercial kit for serum studies, and the intact c‐erbB‐2 oncoprotein (p 185) in the extracts of the tissue membrane fractions with a different kit designed for tissue extract. The level of c‐erbB‐2 immunoreactivity in the cytosol from 124 human breast tumor specimens had an excellent correlation with the cell membrane concentrations of p 185 (γ = 0.89). Most of the elevated cytosol c‐erbB‐2 immunoreactivities were also found to associate with breast tumor specimens containing low concentrations of ER&PgR. It appears that measuring the c‐erbB‐2 immunoreactivity potentially could be used as a prognostic marker without performing tissue biopsies and also as a serum tumor marker for managing cancer patients.©1995 wiley‐Liss, inc.
Comparative study of the genepath group 4 reagent system and other chef systems for karyotype analysis of candida spp
Authors: Holmberg K. , Feroze F. 
Published: March 2007

AbstractThe commercial GenePath Group 4 Reagent Candida kit (BioRad), designed to simplify the electrophoretic karyotyping of Candida spp. was evaluated against several other established contour‐clamped homogeneous electric field (CHEF) systems for Candida. This comparison allowed assessment of both the GenePath system and the other CHEF systems regarding the sources of technical variability of the assays and variation in karyotypic analysis.The GenePath system appeared to be a simple, rapid and reliable tool for karyo‐typing of Candida spp. with a discriminatory power comparable with established CHEF systems. The evaluation showed that the variability of the CHEF systems for subtyping of Candida is largely a function of technical variabilities in the assay system (reagents, sample preparation, running conditions, and test performance), and of analytical variabilities due to imprecision or observers bias. Lack of standardization of these factors may contribute to variability among investigators and have an impact on the ultimate conclusions of an epidemiological study using CHEF methods.©1995 wiley‐Liss, inc.
Further simplification of ultrasensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) for anti‐htlv‐i igg using microplates and fluororeader
Authors: Ishikawa Setsuko , Hashida Seiichi , Nakamoto Hidetaka , Tanaka Satoshi , Kojima Masaaki , Ishikawa Eiji 
Published: March 2007

AbstractIn a previously reported ultrasensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) for anti‐HTLV‐I IgG, polystyrene beads were handled with tweezers, and bound b̃‐D‐galactosidase activity was measured with a fluorometer. The use of tweezers was causative of false‐positivity by carryover, and testing many samples was difficult. Recently, these drawbacks have been minimized using microplates and a fluororeader. However, tweezers were still required in the initial and final steps. In the present study, the immune complex, comprising 2,4‐dinitrophenyl‐antigen, anti‐HTLV‐I IgG, and antigen‐b̃‐D‐galactosidase conjugate, was formed in and trapped onto microplate wells coated with (anti‐2,4‐dinitrophenyl group) IgG. Subsequently, the microplate wells were incubated with ϵN‐2,4‐dinitrophenyl‐L‐lysine and polystyrene beads, modified by attaching to plates through cylindrical bars and coated with (antihuman IgG γgM‐chain) IgG, to transfer the immune complex from the microplate wells to the modified polystyrene beads. Alternatively, modified polystyrene beads coated with (anti‐2,4‐dinitrophenyl group) IgG and microplate wells coated with (antihuman IgG γgM‐chain) IgG were substituted for microplate wells coated with (anti‐2,4‐dinitrophenyl group) IgG and modified polystyrene beads coated with (antihuman IgG γgM‐chain) IgG, respectively. The fluorescence intensity for bound b̃‐D‐galactosidase activity was quickly measured with a fluororeader. Thus the modified polystyrene beads were transferred from wells to wells more quickly and easily without tweezers, eliminating false‐positivity due to carryover, and it became easy to test many samples with high sensitivity and reliability, although the assay of bound b̃‐D‐galactosidase activity became slightly more time‐consuming.©1995 wiley‐Liss, inc.
Use of pyruvate oxidase to overcome pyruvate inhibition during the lactate to pyruvate reaction for assaying lactate dehydrogenase in serum
Authors: Murthy Vadiraja V. 
Published: March 2007

AbstractAutomated assays of lactate dehydrogenase (LD) in serum are based on measuring the rate of NADH produced in a reverse LD reaction using lactate and NAD. The observed nonlinearity of LD reaction used in earlier assays performed in phosphate buffers has generally been attributed to the formation of a ternary complex of NAD, pyruvate, and phosphate. This is not satisfactory to explain the course of assay reaction carried out in organic buffers.Investigation of the possible causes of nonlinearity during the course of the reverse LD reaction during LD assays performed in Tris or other organic buffers indicated that inhibition of LD activity by pyruvate may be chiefly responsible for the observed effects, especially in serum exhibiting abnormally high LD enzyme activity. Most of the LD activity in serum was inhibited by 5 mMoles/L pyruvate. By contrast, the LD isoenzyme activities were inhibited partially at 0.5 mMole/L pyruvate, LD1 being the most and LD4 the least susceptible.In assays of serum samples with abnormally high LD and PYR concentration using LD reagent containing Tris buffer, pH 9.3, the inclusion of a bacterial pyruvate oxidase (PO) enabled the removal of pyruvate accumulating in situ, making it possible to assay LD activity in the absence of inhibitory concentration of pyruvate. The inclusion of 10 U/L of PO in our routine LD reagent was sufficient to overcome pyruvate inhibition, thus permitting the assay of serum exhibiting high LD activity, hence the extension of the upper limits of linearity of LD assay without compromising assay performance.
Urinary gonadotropin peptide: Collection of specimens and cutoff levels
Authors: Plebani Mario , Navaglia Filippo , Bacelle Lucio , Polonio Simonetta , Lazzari Francesca , Marchetti Maria 
Published: March 2007

AbstractA low‐molecular‐weight form of human chorionic gonadotropin (hCG), urinary gonadotropin peptide (UGP), has been isolated from the urine of pregnant women and of patients with cancer, mainly of gynecological origin. The clinical value of UGP measurement in gynecological diseases is under investigation but a preliminary study is necessary in order to ascertain whether there is a circadian rhythm in UGP production, to clarify the best way to express the results, and to establish the cutoff and decisional values.In our work we demonstrated a significant correlation between the UGP output and the UGP excretion normalized for urinary creatinine. A very significant agreement was even found in 24‐hr urine collections and UGP concentration of a single morning specimen from the same patients. No evident circadian rhythm was found, although some patients presented morning levels of UGP higher than in other collections.UGP postmenopausal levels were higher than premenopausal. The cutoff level, adopting the 95.0 percentile, was 200 pmol/mol creatinine.
Psa immunoreactivity detected in lncap cell medium, breast tumor cytosol, and female serum
Authors: Wu James T. , Zhang Ping , Astill Mark E. , Wilson Lori W. , Lyons Bradley W. , Wu Lily L. , Stephenson Robert 
Published: March 2007

AbstractWe made an effort to identify a reliable source for obtaining large quantities of both free (PSA) and PSA–ACT complex for the preparation of the calibrator for the PSA assay. Using size exclusion chromatography, we found both free PSA and PSA–ACT complex in the conditioned cell medium of the LNCaP cell line, which was derived from a human metastatic adenocarcinoma of the prostate. An assay specific for PSA–ACT reacted only with the PSA–ACT complex from cells grown in serum‐free medium, and not with the complex from the cell medium grown in 10% calf serum. We also found both free PSA and PSA–ACT complex in 15% of cytosols prepared from breast tumor tissues; the cytosol PSA concentrations ranged from 0.1 to 110 ng/ml. No correlation was found between cytosol PSA and concentrations of estrogen receptor, progestin receptor, epidermal growth factor receptor, cathepsin D, or the ectodomain of c‐erbB‐2 protein. Based on chromatographic characterizations and the slope of their dose‐response curves, it appears that both free PSA and PSA–ACT complex found in the cytosols are similar to PSA complex from the cell medium and the serum of prostate cancer patients. Ectopic PSA was also detected in pooled sera from patients with breast, ovarian, pancreatic, and colon carcinoma. The PSA concentrations in these serum pools increased with the level of their dominant tumor marker. In any event, the LNCaP cell medium appears to be a reliable source for obtaining both free and ACT‐complexed PSA of human tumor origin for the preparation of PSA assay calibrators.
Development of a microplate elisa for free psa and psa–act complex in serum
Authors: Wu James T. , Wilson Lorraine W. 
Published: March 2007

AbstractAn ELISA on microplate was established for the total serum PSA. We selected the monoclonal antibody for the assay from commercial sources making certain that it reacted with both free PSA and PSA–α1‐antichymotrypsin (PSA–ACT) complex from human serum with similar affinity (so‐called “equimolar”). We also chose a test format with polyclonal anti‐PSA antibodies coated on the well and monoclonal anti‐PSA antibodies for quantification to gain higher test sensitivity. Two different sample volumes from each specimen, 5 and 50 m̈l, were used for the assay in order not only to further increase test sensitivity and improve precision at both low and highly elevated PSA concentrations, but also to widen the assay concentration range (0–500 ng total PSA per ml). Using two sample volumes also reduces any hook effect and shortens the turn‐around time because repeated determinations are usually required when specimens contain highly elevated PSA concentrations. The use of pooled sera containing approximately 95% PSA–ACT complex and 5% free PSA as a calibrator allows for a close matching of the calibrator with serum specimens in immunoreactivity and PSA composition. Moreover, our assay shows no hook effect up to 15,000 ng/ml. The within‐day precision (% CV) in the critical concentration range of 4–12 ng/mL is approximately 5%. The PSA values obtained from this assay correlate well with that of the Hybritech kit (γ = 0.998, slope equals to 1.033), indicating that this kit can replace the Hybritech Tandem E PSA kit for serum PSA determination in clinical laboratories.
Evaluation of a dipstick method for the detection of human immunodeficiency virus infection
Authors: Beristain Claudio N. , Federico Rojkin L. , Lorenzo Luis E. 
Published: March 2007

AbstractSerology has been a fundamental tool to prevent post‐transfusional infection with human immunodeficiency virus (HIV) and for epidemiological surveys, the first step to attempt control of the pandemia. Enzyme immunoassay is in widespread use. Nevertheless, simpler methods are needed in many countries, where laboratory facilities and trained personnel are limited, and HIV prevalence is high. The evaluation of a simple and noninstrumented HIV antibody test is presented here. The test employs synthetic antigens of HIV‐1 and HIV‐2 attached to the teeth of a polystyrene comb, which fit into the wells of standard microtiter plates where samples are diluted. Captured antibodies are developed with colloidal gold‐labeled Protein A. Three seroconversion panels plus 662 samples were tested, including HIV‐1 and HIV‐2‐infected individuals, normal blood donors, and a noninfected baby born to a seroreactive mother. When compared with enzyme‐linked immunosorbent assay (ELISA) and Western blot, the dipstick showed 100% sensitivity and 98.7% specificity. The simplicity of result evaluations and excellent reagent stability make the dipstick suitable for small blood banks and for epidemiological surveys.
Further characterization of the plasma lipoprotein(a) distribution
Authors: Craig Wendy , Poulin Sue , Bostom Andrew , Eaton Charles , Laurino Joseph , Ledue Thomas , Ritchie Robert 
Published: March 2007

AbstractThe plasma lipoprotein(a) [Lp(a)] distribution in caucasians is heavily skewed to the right, with evidence of bimodality. As there is a well‐described inverse relationship between apolipoprotein(a) [apo(a)] size and Lp(a) concentration, it is likely that the presence of multiple apo(a) isoforms of differing frequency has a significant impact on the final distribution of Lp(a) concentrations. We have previously described an immunoblot method for examining the relationship between apolipoprotein(a) [apo(a)] size and lipoprotein(a) [Lp(a)] mass among samples heterozygous for apo(a) size, thus eliminating confounding by null or undetected apo(a) isoforms. In the present study, this method has been applied to examine the plasma Lp(a) distribution, independent of the effects of apo(a) isoform size and frequency. Seventy subjects heterozygous for apo(a) size were studied. To take into account the inverse relationship (P <0.001) between apo(a) isoform size and Lp(a) concentration, Lp(a) data associated with each apo(a) isoform were normalized as multiples of the median Lp(a) concentration for that isoform. These apo(a) isoform‐independent Lp(a) data demonstrated a strikingly multimodal distribution, with five major peaks. The relative frequencies of Lp(a) peaks 1–5 were 17.1%, 15.0%, 35.7%, 23.6%, and 8.6%, and associated median Lp(a) concentrations were 1.0, 6.2,15.0, 21.8, and 39.6 mg/dL, respectively. Multivariate analysis demonstrated that apo(a) isoform size accounted for 23% and isoform‐independent Lp(a) peaks for 59.5% of the variation in Lp(a) concentration. Further investigation of the characteristics of the apo(a) isoform‐independent Lp(a) distribution is warranted.
Estimating oxygen saturation of blood in vivo with MR imaging at 1.5 T
Authors: Wright Graham A. , Hu Bob S. , Macovski Albert 
Published: March 2007

AbstractThe use of magnetic resonance (MR) imaging is investigated for noninvasively estimating the oxygen saturation of human blood (%HbO2) in vivo by means of relaxation characteristics identified in earlier MR spectrometry studies. To this end, a sequence is presented for determining the T2 of vascular blood in regions in which motions of the body and of the blood itself present a major challenge. With use of this sequence on a commercial 1.5‐T whole‐body imager, the relationship between the T2 and %HbO2 of blood is calibrated in vitro for the conditions expected in vivo. T2 varies predictably from about 30 to 250 msec as %HbO2 varies from 30% to 96%. T2 values measured in situ for vascular blood in the mediastinum of several healthy subjects qualitatively reflected the behavior observed in vitro. Estimates of %HbO2 for these vessels obtained with the in vitro calibration appear reasonable, particularly for venous blood, although difficulties arise in selecting the appropriate calibration factors. These encouraging initial results support a more systematic study of potential sources of error and an examination of the accuracy of in vivo measurements by comparison with direct measurements of %HbO2 in vessels.
Intraluminal contrast enhancement and MR visualization of the bowel wall: Efficacy of PFOB
Authors: Rubin Daniel L. , Muller Holde H. , Nino‐Murcia Matilde , Sidhu Manrita , Christy Valerie , Young Stuart W. 
Published: March 2007

AbstractEfforts to develop satisfactory intraluminal gastrointestinal contrast agents for magnetic resonance (MR) imaging have focused on depicting only the bowel lumen to exclude possible involvement by a pathologic process. To determine whether the bowel wall can be adequately imaged with use of the contrast agent and whether bowel wall visualization is a better index of the utility of the contrast agent for MR imaging, perfluorooctylbromide (PFOB) was studied in human subjects. Twenty consecutive patients referred for abdominal or pelvic MR imaging were selected. All patients were given 400–1,000 mL of PFOB orally. MR imaging was performed at 0.38 and 1.5 T with T1‐ and T2‐weighted spin‐echo pulse sequences before and after administration of PFOB. The images were graded independently by three blinded readers. All readers reported significantly superior conspicuity of the bowel lumen and wall after PFOB than before PFOB administration (P < .002). Among the post‐PFOB studies, those with superior bowel wall visualization demonstrated superior overall image quality. In three patients, lesions were optimally demonstrated because the relationship of the process to the bowel wall, rather than just to the lumen, was identified. In two patients, masses arising within the bowel wall could be identified prospectively only when the bowel wall was adequately imaged. The authors conclude that while lumen identification is improved with PFOB, its greatest clinical utility may be in facilitating intestinal wall visualization.
Evaluation of a simple method for reconstructing asymmetrically sampled echo data
Authors: Mugler John P. , Brookeman James R. 
Published: March 2007

AbstractA simple method for reconstructing echo data with a large degree of sampling asymmetry was investigated. The method is based on the application of an optimized data sampling window before standard Fourier transform magnitude reconstruction. The performance of this “windowed direct” reconstruction was evaluated with theoretical simulations and experimental measurements and compared with that of the half‐Fourier method. With the proper selection of data sampling window parameters, highly asymmetric echo data reconstructed with standard Fourier transform magnitude algorithms produced images similar in quality to those reconstructed with the half‐Fourier method. Windowed direct reconstruction provides a simple and computationally fast alternative to more sophisticated algorithms and may be particularly applicable for specialized or developmental applications.