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PubMed1999

Multicenter comparison of the digene hybrid capture CMV DNA assay (version 2.0), the pp65 antigenemia assay, and cell culture for detection of cytomegalovirus viremia.

We compared the Digene Hybrid Capture CMV DNA Assay version 2.0, the pp65 antigenemia assay, traditional tube culture, and shell vial culture for the detection of cytomegalovirus (CMV) viremia in several patient populations at three centers. Of 561 blood specimens collected from 402 patients, complete clinical and laboratory data were available for 489. Using consensus definitions for true positives and true negatives, the sensitivities of the Hybrid Capture assay, antigenemia, shell vial, and tube culture were 95, 94, 43, and 46%, respectively. The specificities of the Hybrid Capture assay and antigenemia were 95 and 94%, respectively. At all three study sites, the detected level of CMV viremia was significantly higher with the Hybrid Capture assay or antigenemia than with shell vial and tube culture. In a group of 131 healthy nonimmunosuppressed volunteers, the Hybrid Capture assay demonstrated a specificity of over 99%. The Hybrid Capture assay is a standardized assay that is simple to perform and can utilize whole blood specimens that have been stored for up to 48 h. The high sensitivity and specificity of the Hybrid Capture assay along with its simplicity and flexibility make it a clinically useful assay for the detection of CMV viremia in immunocompromised or immunosuppressed patients. Further evaluation to determine its role in predicting CMV disease and for monitoring the therapeutic response to anti-CMV therapy is needed.

Adolescent↗

PubMed2001

Qualitative plasma PCR assay (AMPLICOR CMV test) versus pp65 antigenemia assay for monitoring cytomegalovirus viremia and guiding preemptive ganciclovir therapy in allogeneic stem cell transplantation.

The performances of a commercially available qualitative plasma PCR assay (AMPLICOR CMV test; Roche Diagnostics) and the pp65 antigenemia assay (AG) were evaluated for the monitoring of cytomegalovirus (CMV) viremia in 43 allogeneic stem cell transplant recipients. In addition, the suitabilities of both assays for triggering the initiation of preemptive ganciclovir therapy were assessed. A total of 37 CMV viremic episodes were detected in 28 patients. Positivity of plasma PCR testing in one or more consecutive specimens was the only marker of CMV viremia in 18 of the 37 episodes (PCR positive and AG negative, n = 50 specimens). Five episodes were diagnosed on the basis of a single positive AG result (AG positive and PCR negative, n = 5 specimens); both assays were eventually positive (PCR positive and AG positive, n = 27 specimens) for 14 viremic episodes; for these episodes, conversion of the PCR assay result to a positive result occurred an average of 1 week before conversion of the AG result. Overall, the concordance between the two methods was 90%, and the sensitivities of the plasma PCR assay and AG for the detection of CMV viremic episodes were 86.5 and 51.3%, respectively. Two patients who tested positive by both assays simultaneously progressed to CMV end-stage organ disease, despite the initiation of preemptive ganciclovir therapy. Conversion of the AG result to a negative result upon administration of preemptive ganciclovir therapy occurred a median of 7.5 days earlier than conversion of the plasma PCR assay result. Nineteen of the 28 patients with CMV viremia received AG-guided preemptive ganciclovir therapy; had the positivity of the plasma PCR assay triggered the initiation of preemptive therapy, 9 additional patients would have been unnecessarily treated since none of them developed CMV end-stage organ disease. Although the AMPLICOR CMV assay is more sensitive than AG, the latter appears to be more suitable both for guiding the initiation of preemptive therapy and for monitoring a patient's response to antiviral therapy.

Antiviral Agents↗

PubMed2003

Real-time PCR assay compared to nested PCR and antigenemia assays for detecting cytomegalovirus reactivation in adult T-cell leukemia-lymphoma patients.

We analyzed the efficiency of the quantitative real-time PCR assay for cytomegalovirus (CMV) reactivation in adult T-cell leukemia-lymphoma (ATL) patients and compared the results with those obtained with qualitative nested PCR and antigenemia assays. The viral load obtained by the real-time PCR assay closely paralleled the number of antigen-positive cells obtained with the antigenemia assay. Real-time PCR revealed that a large number of DNA copies could be present even in samples assessed as negative or low in antigen-positive cells (0 to 10 antigen-positive cells/50,000 cells) by antigenemia assay. CMV copy numbers did not differ between the negative and low-antigen-positive groups. When the input concentration for real-time PCR assay was 2,500 to 5,000 copies/ml, the positivity rate for the nested PCR assay was 47.3%, while the positivity rate was more than 90% at an input concentration of >/=50,000 copies/ml. Real-time PCR is more sensitive than the antigenemia and nested PCR assays. Moreover, real-time PCR was able to detect CMV reactivation earlier than the antigenemia and nested PCR assays through the use of longitudinal analysis in four ATL patients with CMV pneumonia. In longitudinal assessments, analysis of the results suggested that a cutoff level of 5,000 copies/ml might be used to initiate treatment. Real-time PCR is more suitable for monitoring CMV reactivation in ATL patients than the antigenemia and nested PCR assays. CMV viral loads of 5,000 copies/ml are proposed as the cutoff for initiating antiviral therapy in ATL patients.

Adult↗

PubMed2005

Evaluation of the COBAS Hepatitis C Virus (HCV) TaqMan analyte-specific reagent assay and comparison to the COBAS Amplicor HCV Monitor V2.0 and Versant HCV bDNA 3.0 assays.

Performance characteristics of the COBAS hepatitis C virus (HCV) TaqMan analyte-specific reagent (TM-ASR) assay using the QIAGEN BioRobot 9604 for RNA extraction were evaluated and compared to the COBAS Amplicor HCV Monitor V2.0 (Amplicor) and Versant HCV bDNA 3.0 (Versant) assays using clinical samples. Calibration of TM-ASR using Armored RNA allowed determination of the distribution of HCV RNA in clinical samples, using 22,399 clinical samples. Limit of detection, linearity, and inter- and intraassay assay precision were determined for the TM-ASR assay using multiple clinical specimen panels across multiple determinations. Genotype specificity for the TM-ASR assay was determined using samples with different HCV RNA genotypes evaluated and compared against predetermined results. Contamination control of the TM-ASR assay was evaluated using pools of HCV RNA-positive and -negative samples tested in a checkerboard pattern over 12 runs of 96 samples. Correlation of the TM-ASR, Amplicor, and Versant assays was determined using 100 paired clinical samples and Deming regression analysis. The TM-ASR performed well with respect to linearity, precision, and contamination control. The correlation between TM-ASR and the Amplicor and Versant assays was poor, with large differences between assay results for individual samples. Calibration of the TM-ASR assay with Armored RNA allowed for a wide dynamic range and description of the distribution of HCV RNA in clinical samples.

DNA, Viral↗

PubMed1999

Homogeneous Cell- and Bead-Based Assays for High Throughput Screening Using Fluorometric Microvolume Assay Technology.

High throughput drug screening has become a critical component of the drug discovery process. The screening of libraries containing hundreds of thousands of compounds has resulted in a requirement for assays and instrumentation that are amenable to nonradioactive formats and that can be miniaturized. Homogeneous assays that minimize upstream automation of the individual assays are also preferable. Fluorometric microvolume assay technology (FMAT) is a fluorescence-based platform for the development of nonradioactive cell- and bead-based assays for HTS. This technology is plate format-independent, and while it was designed specifically for homogeneous ligand binding and immunological assays, it is amenable to any assay utilizing a fluorescent cell or bead. The instrument fits on a standard laboratory bench and consists of a laser scanner that generates a 1 mm(2) digitized image of a 100-µmm deep section of the bottom of a microwell plate. The instrument is directly compatible with a Zymark Twistertrade mark (Zymark Corp., Hopkinton, MA) for robotic loading of the scanner and unattended operation in HTS mode. Fluorescent cells or beads at the bottom of the well are detected as localized areas of concentrated fluorescence using data processing. Unbound flurophore comprising the background signal is ignored, allowing for the development of a wide variety of homogeneous assays. The use of FMAT for peptide ligand binding assays, immunofluorescence, apoptosis and cytotoxicity, and bead-based immunocapture assays is described here, along with a general overview of the instrument and software.

Journal Article↗

PubMed2003

Clinical and technical evaluation of the ACS:OV serum assay and comparison with three other CA125-detecting assays.

BACKGROUND: In this study the clinical and technical performance of the CA125- detecting Bayer ACS:OV immunoluminometric serum assay was compared with three other well-established CA125-detecting assays. METHODS: A total of 1112 serum samples was included in this evaluation: 462 from apparently healthy women, 153 from patients with benign ovarian disease, 163 from patients with malignant ovarian disease, 10 from patients with borderline ovarian malignancies and 78 samples from 12 ovarian cancer patients during monitoring of disease. Serum samples from women with malignant endometrial (n = 68) and colon (n = 32) diseases were also included. Moreover, serum samples from women with benign uterine disease and endometriosis (n = 136) plus 10 serum samples from men (n = 7) and women (n = 3) with human anti-mouse antibodies (HAMA) after immunoscintigraphy were included. All samples were tested in duplicate with the Bayer ACS:OV, the Centocor CA125 II, the Abbott IMx CA125 and the Roche (formerly Boehringer Mannheim) Enzymun-Test CA125 II assays. RESULTS: The clinical performance of the Bayer ACS:OV assay, assessed in various patient groups, was similar to that of the two other automated assays. In serum from patients with benign diseases the highest values were found in patients with benign ovarian tumours. In the ovarian cancer patients followed during the course of disease we found similar marker patterns with all four assays. In contrast to the Roche Enzymun-CA125 II assay and to a lesser extent the Centocor CA125 II assay, the Bayer ACS:OV assay was less sensitive to interference from HAMA. CONCLUSION: The Bayer ACS:OV assay is a precise and reliable test for the quantification of CA125 in serum.

Biomarkers, Tumor↗

PubMed2001

Assessment of HER-2/neu status in breast cancer. Automated Cellular Imaging System (ACIS)-assisted quantitation of immunohistochemical assay achieves high accuracy in comparison with fluorescence in situ hybridization assay as the standard.

This retrospective study of formalin-fixed infiltrating breast cancer specimens compared manual immunohistochemical assay with a new image analyzer-assisted immunohistochemical quantitation method, using fluorescence in situ hybridization assay (FISH) as the standard. Following the manual immunohistochemical assay, 189 cases, including most manual immunohistochemically positive and some random negative cases, were analyzed by FISH assay for Her-2/neu gene amplification and by the Automated Cellular Imaging System (ACIS) for immunohistochemical staining. Using the FISH standard, the ACIS immunohistochemical assay attained a higher concordance rate and sensitivity than the manual immunohistochemical assay (91.0% and 88% vs 85.7% and 71%, respectively), with only a slight decrease in specificity (93% vs 96%, respectively). In particular, the ACIS immunohistochemical assay resulted in a higher correlation with the FISH assay in the manual immunohistochemical assay 2+ cases. The ACIS immunohistochemical assay achieved higher accuracy than the manual method according to receiver operating characteristic curve analysis. The ACIS method represents a substantial improvement over the manual method for objective evaluation of the HER-2/neu status.

Breast Neoplasms↗

PubMed1993

Determination of the catalytic activity of phospholipase A2: E. coli-based assay compared to a photometric micelle assay.

Phospholipase A2 activity in human sera was determined of the basis of the E. coli assay and compared to a photometric micelle assay. The E. coli assay is based on the hydrolysis of phospholipids from [1-14C]oleic acid-labelled E. coli biomembranes. In the photometric assay the phospholipase A2 acts on mixed phospholipid micelles. The amount of fatty acid produced is quantitated in a subsequent photometric assay by coupling in the reaction to the coenzyme A metabolism. The E. coli membranes are essentially resistant to other lipases in human sera, i.e. lipoprotein lipases, hepatic triacylglycerolipase or pancreatic lipase and thus a very specific substrate for the phospholipase A2 of human serum. The photometric assay, though, is susceptible to other lipases in human serum. The ratio of [1-14C]oleic acid to released total fatty acids served as the basis for the calculation of the true enzymatic activity. The assay closely correlated with the photometric assay based on mixed micelles in the higher ranges of phospholipase A2 activity, but not in the normal range. The sensitivity is higher by at least two powers of 10. The human serum phospholipase A2 strongly preferred E. coli membranes as substrate to the mixed micelles containing phosphatidylcholine/phosphatidylethanolamine. In conclusion, the modified phospholipase A2 assay based on E. coli membranes is a sensitive, specific, reliable, and convenient method for the measurement of phospholipase A2 activity in human sera. The photometric assay suffers from low sensitivity but has the advantage of practicability in a normal routine laboratory, including the amenability to automation.

Acute-Phase Proteins↗

PubMed1999

Comparison of the sensitivity and specificity of an automatic ligase chain reaction assay system with a one-step polymerase chain reaction assay in the diagnosis of Mycobacterium tuberculosis complex.

BACKGROUND: Polymerase chain reaction (PCR) and ligase chain reaction (LCR) are two nucleic acid amplification-based molecular methods. The former has been used widely in the identification of Mycobacterium tuberculosis (M. tuberculosis). In contrast, the LCR assay which was recently introduced is not well known in our medical communities in Taiwan. To determine which method is more reliable and suitable for the identification of M. tuberculosis in our clinics, we compared the sensitivity and specificity of these two methods. METHODS: An automatic LCR assay system and a manual one-step PCR assay were studied in a side by side comparison of their performance in detection of M. tuberculosis. The automatic LCR system uses the single copy antigen protein b (Pab) gene and the manual one-step PCR assay uses the multi-copy IS6110 insertion element as the target DNA; both target DNA sequences are found specifically in M. tuberculosis complex. RESULTS: Both assays detected two of the M. tuberculosis complex strains, M. tuberculosis and M. bovis, but not other mycobacterial strains. In addition, both methods, which were based on different amplification principles, showed compatible sensitivity; as low as 10 and 100 copies of M. tuberculosis genomes were detected by the LCR and PCR assays, respectively. When the template DNA was less than 1000 copies, however, the automatic LCR assay system showed a lower reproducibility than that of the one-step PCR assay. CONCLUSION: Our results suggest that in addition to the PCR assay, the LCR assay is a useful method for the molecular identification of M. tuberculosis complex strains.

DNA Ligases↗

PubMedDate not supplied

Comparison of the dot blot hybridization assay with antigen detection assays for the diagnosis of infectious bursal disease virus infections.

The use of cDNA probes as diagnostic tools for detecting infectious bursal disease virus (IBDV) antigens was compared with the agar-gel precipitin (AGP) and immunofluorescence (IF) assays. Specific-pathogen-free chickens were inoculated with the STC or IN strains of IBDV in three separate experiments. Tissue samples were collected at various intervals postinoculation (PI) and examined for viral antigens using the IF assay, the AGP assay, and the hybridization assay. Viral antigen was detected by the AGP assay for a period of approximately 3 days beginning 2 days PI and by the IF assay for approximately 4 days beginning 2 days PI. Virus was detected by the hybridization assay through the length of all the experiments (longest experiment was 24 days) beginning 1 day PI. These results suggested that the hybridization assay is more sensitive than the IF assay and the AGP assay.

Animals↗

PubMed1980

Specific immunodiagnosis of hepatoma by tube leukocyte adherence inhibition assay and a modified method of repeated tube leukocyte adherence inhibition assay.

Tube leukocyte adherence inhibition (LAI) assays were performed with normal liver extract as nonspecific antigen and with hepatoma extract as specific antigen in patients with hepatoma. Titration experiments revealed that the optimal extract concentration was 400 micrograms/ml when expressing the results in terms of a nonadherence index. The results of tube LAI assays were positive in 26 of 40 cases (65%) of hepatoma. The results were negative in all cases of other liver diseases and other cancers. The tube LAI assay was repeated after discarding the non-adherent cells in the initial tube LAI assay with normal liver extract. The nonadherence index of the repeated tube LAI assay we devised was significantly higher than that of the original tube LAI assay (p less than 0.001) in patients with hepatoma. Ten of 12 patients with hepatoma in whom the results of the original tube LAI assay were negative showed positive results in the repeated tube LAI assay. The present study suggests that the problem of false-negative results in tube LAI assay can be solved by repeating the tube LAI assay.

Antigens, Neoplasm↗

PubMed1982

Assay of prekallikrein in human plasma: comparison of amidolytic, esterolytic, coagulation, and immunochemical assays.

Using the substrate H-D-Pro-Phe-Arg-p-nitroanilide-HCl, an amidolytic assay was designed to measure prekallikrein in plasma. At a substrate concentration of 1 mM (Km = 0.2 mM), the amidolysis of purified kallikrein at 1 coagulant unit/ml was observed to be 2.47 mumole/min/ml. Conditions for plasma prekallikrein activation were optimized to approach complete activation when compared to the amidolytic activity of the purified plasma kallikrein. Plasma treated with chloroform to destroy inhibitors of kallikrein was activated with dilute kaolin (final concentration 1 mg/ml) for 1 min at 25 degrees C. Activated plasma prekallikrein had 78% (1.92 mumole/min/ml) of activity of purified kallikrein at plasma concentration. Comparison of this amidolytic assay with immunochemical, esterolytic, and coagulant assays of three subject populations (normals, women on birth control pills, and patients with hepatocellular disease) showed good correlation both in normals and in the patient groups between the amidolytic and esterolytic assays (r = 0.89). Each enzymatic assay correlated with the immunochemical assay (r = 0.72, r = 0.68, respectively). However, comparison of each of these assays with the coagulant assay showed no significant correlation due to the large inherent error of the latter assay. This standardized plasma prekallikrein amidolytic assay should facilitate studies of plasma prekallikrein concentration in physiologic and pathologic conditions and help identify activation of the contact phase of coagulation in disease states.

Blood Coagulation Tests↗

PubMed1982

Avidity of antibodies to dsDNA: comparison of IFT on Crithidia luciliae, Farr assay, and PEG assay.

The Farr assay is thought to detect only antibodies to DNA of relative high avidity. This is due to the high salt concentration of the employed ammonium sulfate precipitation, which dissociates DNA-anti-DNA complexes of low avidity. A recently introduced method to detect anti-DNA, the PEG assay, circumvents these dissociating reaction conditions by using polyethylene glycol instead of ammonium sulfate to precipitate the complexes; we therefore thought to measure antibodies to DNA of low avidity as well. We tested this assumption in several ways. It was found that the PEG assay detects a population of antibodies to DNA that are missed by the Farr assay. Complexes made with these antibodies were salt labile and could readily be dissociated by means of excess DNA, whereas Farr-positive antibodies formed stable complexes with DNA. Avidity studies using the method described by Celada et al. indicated that the anti-DNA detected by the PEG assay but missed by the Farr assay was of relatively low avidity. An inverse correlation between avidity and slope of the binding curves in the PEG assay was observed. These results confirm the notion that the PEG assay detects antibodies to DNA of low avidity. The fact that the Farr assay does not measure these antibodies confers possible diagnostic importance upon the PEG assay.

Antibody Affinity↗

PubMed1987

Comparative study on nude mice isotope assay (NM-IA) and subrenal capsule assay (SRCA) sensitivity tests of anticancer agents.

A comparative study on nude mice isotope assay (NM-IA) and subrenal capsule assay (SRCA) was done to evaluate the usefulness of in vivo assays for predicting individual tumor sensitivity against anticancer agents. Sixty-one fresh tumor specimens collected at surgery, under sterile conditions, were examined. Mitomycin C (MMC), 5-fluorouracil (5-FU), cyclophosphamide (CPM), adriamycin (ADM) and cis-DDPlatinum (CDDP) were used in both assays. In NM-IA, the tumor sensitivity was determined by the amount of 3H-thymidine incorporated into the tumor which had been implanted into subcutaneous spaces of BALB/c nude mice. In the SRCA, the relative increase in weight of the tumor implanted into the subrenal capsular space of ddY mice was determined and measurements made to evaluate the chemosensitivity. Evaluability rates of the trials were 86.9 per cent with both assays and the response rates were 35.8 per cent in NM-IA and 34.0 per cent in SRCA, respectively. Against MMC, 5-FU, CPM, ADM and CDDP, overall consistency rates between the two assays were 77.8 per cent, 88.6 per cent, 72.7 per cent, 81.8 per cent and 68.2 per cent, respectively. In 8 of these 53 evaluated assays, correlations between the results of assays and clinical effects were examined and overall predictive accuracy rates were 87.5 per cent with both assays. Significant differences between these two in vivo chemosensitivity tests were not evident.

Animals↗

PubMedDate not supplied

The peripubertal male rat assay as an alternative to the Hershberger castrated male rat assay for the detection of anti-androgens, oestrogens and metabolic modulators.

A range of chemicals with various levels of activity as actual or potential endocrine disrupters have been evaluated for activity in the peripubertal male rat assay. The chemicals studied included anti-androgens (vinclozolin), cyproterone acetate, flutamide, 2, 2-bis(4-chlorophenyl)-1,1-dichloroethylene (DDE), metabolic modulators (anastrazole, finasteride, ketoconazole) and oestrogens (butyl benzyl phthalate (BBP), methoxychlor, bisphenol A (BPA), diethylstilboestrol (DES)), the suspected anti-androgen dibutyl phthalate (DBP) and the non-oestrogen fenitrothion. Dosing extended over postnatal days (pnd) 22-35, 36-50, 36-55 and 22-35, with recovery to pnd 55 or 22-55. The endpoints studied were changes in the weights of testes, epididymides, seminal vesicles and prostate. Changes in body weight and the weights of the liver and kidney were also monitored. In some experiments changes in the day of prepuce separation (PPS) were also determined. Only BBP and BPA were inactive in all the assays conducted. Changes in the weight of reproductive tissues provided a sensitive indicator of activity for the remaining chemicals with the exception of DDE, for which higher dose levels could have been used. However, none of the curtailed periods of exposure were able to detect all of the agents. Diethyl stilboestrol, and to a lesser extent DBP and DDE, delayed PPS when exposure occurred over the period pnd 22-55. A complex dependence of the day of PPS on the period of exposure and the body weight of the test animals was observed, and caution is recommended when assessing this endpoint in the presence of reductions in body weight. It is concluded that reproductive tissue weight changes in the peripubertal male have shown sensitivity to a range of biochemical modulators, oestrogens and anti-androgens, and that as such the assay warrants further evaluation. Measurement of delays in PPS may be of value in cases of large delays, but delays of 1-2 days will be difficult to interpret with confidence. The present results are discussed within the context of the sexually mature male rat assay described by O'Connor and the castrated male rat assay described by Hershberger, both of which are the subject of current international study. It is concluded that a decision on the usefulness of the peripubertal male rat assay must await the generation of further data on each of these three assays. There is an urgent need for international agreement on a list of reference endocrine disrupters and their active dose levels, with which to validate individual endocrine disruption assays and batteries of assays.

Anastrozole↗

PubMed1998

Comparison of a novel micro-assay for insulin autoantibodies with the conventional radiobinding assay.

Measurement of insulin autoantibodies (IAA) with a novel micro radiobinding assay which requires only 20 microl of serum was compared with that in a conventional radiobinding assay which uses 600 microl of serum. IAA were measured with both assays in samples from 94 new onset insulin-dependent diabetes mellitus (IDDM) patients, 97 control subjects. and 48 first degree relatives of IDDM patients selected for having IAA in the conventional radiobinding assay. Overall, 227 (95%) of 239 samples tested were concordant. and IAA levels correlated well (r2 = 0.7) between the two assays. Discordant results were obtained in 7 new onset patients, 4 control subjects, and 1 first degree relative, and these had low IAA levels in the respective assays. Sensitivity and specificity in the new onset IDDM patients and control subjects were 69% and 98% for the micro radiobinding assay and 72% and 98% for the conventional radiobinding assay. The use of the micro radiobinding assay should greatly facilitate islet related antibody screening, particularly in children.

Adolescent↗

PubMed2003

Immature rat uterotrophic assay of 18 chemicals and Hershberger assay of 30 chemicals.

We performed an immature rat uterotrophic assay of 18 chemicals and Hershberger assay of 30 chemicals to assess the relationship between the results of two assays. The chemicals tested by the uterotopic assay were 4-n-amylphenol, p-dodecyl-phenol, p-(tert-pentyl)phenol, 4-cyclohexylphenol, 4-(1-adamantyl)phenol, 4,4'-thiobis-phenol, diphenyl-p-phenylenediamine, 4-hydroxyazobenzene, 4-(phenylmethyl)phenol, 4,4'-(hexafluoroisopropylidene)diphenol, 2,2-bis(4-hydroxyphenyl)-4-methyl-n-pentane, 4,4'-(octahydro-4,7-methano-5H-inden-5-ylidene)bisphenol, 4,4'-dihydroxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 4-hydroxybenzophenone, 2,4,4'-trihydroxybenzophenone, testosterone enanthate, and methyltestosterone. The chemicals tested by the Hershberger assay were the 18 chemicals tested in the uterotrophic assay plus the following: 17 alpha estradiol, estrone, equilin, norethindrone, norgestrel, ethynyl estradiol, bisphenol A, bisphenol B, bisphenol F, 4-tert-octylphenol, p-cumyl phenol, and nonylphenol. All chemicals examined in this study were positive in a reporter gene assay for ER-alpha. In the immature rat uterotrophic assay, all chemicals induced uterotrophy and p-(tert-pentyl)phenol, 4,4'-thiobis-phenol, 4-(phenylmethyl)phenol, 4,4'-(hexafluoroisopropylidene)diphenol, 2,2-bis(4-hydroxyphenyl)-4-methyl-n-pentane, 4,4'-(octahydro-4,7-methano-5H-inden-5-ylidene)bisphenol, 4,4'-dihydroxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 4-hydroxybenzophenone, and 2,4,4'-trihydroxybenzophenone exerted both estrogen agonistic effect and reduced the estrogenic effect of ethynylestradiol. In the Hershberger assay, a clear androgen agonistic effect was detected in the androgen derivatives testosterone enanthate and methyltestosterone.

Androgen Antagonists↗

PubMed1999

A novel assay for serum complement activity: C42 generation assay.

BACKGROUND: In most clinics, laboratory tests for serum complement are limited to immunochemical determinations of C3 and C4 and are occasionally extended to the hemolytic titration of total complement functional activity (CH50). However, these tests are often not sufficient for the analysis of low CH50 serum. METHODS: A novel assay for serum complement activity, the C42 generation assay, has been developed. The principle of this assay is based on the hemolysis of sensitized sheep erythrocytes (EA) by complement components in two sera: C42 (the classical pathway C3 convertase) is generated on EA by C1, C4 and C2 in the first serum, followed by a second reaction leading to hemolysis by C3-C9 supplied by the addition of the second serum in the presence of EDTA. RESULTS: This methodology permits the evaluation of two distinct serum complement activities of a test serum. The combined activity of C1, C4 and C2, as well as the combined activity of C3-C9, can be estimated from the observed degrees of hemolysis. Information obtained from this assay is helpful for the analysis of test serum determined to have decreased CH50. Several clinical cases are presented in which this assay was utilized. CONCLUSIONS: The C42 generation assay is another functional assay of serum complement which can provide information beyond that obtained from the typical serum CH50 assay. Since intermediate cells or isolated complement components are not necessary, this assay can be employed rapidly and economically in a clinical setting.

Animals↗