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At least 19 recordsLinked to original sources
PubMed1991

Biological assays for interleukin 1 detection. Comparison of human T lymphocyte, murine thymocyte and NOB-1 assays.

Various biological assays are used for qualitative and quantitative measurements of interleukin 1 (IL-1) in supernatants from cell cultures. The purpose of the present study was to compare the specificity and variability of three cellular IL-1 bioassays: the PHA co-stimulatory human T lymphocyte proliferation assay, the PHA co-stimulatory murine thymocyte (THY) proliferation assay, and the 2-step NOB-1 conversion assay. Three different ways of IL-1 unit calculation, based on a semi-logarithmic plot, a double-logarithmic plot, or a probit-analysis plot were also compared. The T lymphocyte assay can be used only to demonstrate qualitative differences in IL-1-like activity, whereas the THY assay is excellent as a semi-quantitative assay, with a low intra-assay variability, but also with a low specificity. The NOB-1 assay is probably more specific with respect to IL-1 measurement, although, with a high intra-assay variance. The THY and the NOB-1 assays both have a high inter-assay variability, and measurement of samples from longitudinal clinical studies must be done in one and the same analysis if quantitative differences are to be illustrated. Probit analysis for unit calculation is recommended. To generate a consensus view as to assay performance, collaborative laboratory studies are needed.

Animals↗
PubMed1999

Evaluation of a bacteriophage-based assay (phage amplified biologically assay) as a rapid screen for resistance to isoniazid, ethambutol, streptomycin, pyrazinamide, and ciprofloxacin among clinical isolates of Mycobacterium tuberculosis.

Rapid molecular assays for the detection of mutations associated with rifampin resistance in Mycobacterium tuberculosis are commercially available. However, they are complex and expensive and have predictive values of 90 to 95%. Molecular assays for other drugs are less predictive of resistance. Ideally, assays based on phenotypic markers should be used for susceptibility testing, but these can take weeks to complete. We previously described a rapid phenotypic assay, the phage amplified biologically (PhaB) assay, for the rapid determination of rifampin and isoniazid susceptibility in clinical isolates of M. tuberculosis. In this study, we extended the assay to the study of ethambutol, pyrazinamide, streptomycin, and ciprofloxacin. After the optimization of antibiotic concentrations and incubation conditions, the assay was applied to each drug for a total of 157 isolates. The correlations between the results of the PhaB assay and the resistance ratio method were 94% for isoniazid, 96% for streptomycin, 100% for ciprofloxacin, 88% for ethambutol, and 87% for pyrazinamide. For ciprofloxacin, ethambutol, and pyrazinamide, significantly better correlations were found when a 90% reduction in plaque count was used as the cutoff. Turnaround times for the PhaB assay were 2 to 3 days, compared with 10 days for the resistance ratio method. We believe that this low-cost assay may have widespread applicability for the rapid screening of drug resistance in M. tuberculosis isolates, especially in developing countries.

Antitubercular Agents↗
PubMed1991

Animal test or chromatography? Validated high-performance liquid chromatographic assay as an alternative to the biological assay for ornipressin.

Ornipressin is a peptide drug which is usually assayed by a test on live rats. In order to reduce the animal experiments an alternative method was developed which uses gradient high-performance liquid chromatography (HPLC) on reversed-phase. The HPLC method was validated and shown to be selective and precise. Correlation studies were performed on samples of different dosage strengths and on thermally degraded samples, showing good correlation with the results obtained by the biological assay. The HPLC method was applied on various batches of ornipressin in bulk and in pharmaceutical preparations. HPLC is a rapid and inexpensive method which can replace the animal assay. A new quality control concept is proposed which uses HPLC for the analysis of ornipressin in bulk and in pharmaceutical preparations. With this concept animal testing can be reduced by 90%.

Amino Acid Sequence↗
PubMed1989

An overview of the strengths and limitations of biological assays in quality control.

Biological assays have been an integral part of the regulation of biological products in the United States since licensing of the first product in 1902. Bioassays have been used along with other methodologies in the assessment of identity, purity, safety, potency and stability. The technology of production, i.e. normal or recombinant, has not altered the use or value of these assays. Although many scientists and regulators would prefer to replace all in vivo bioassays with other assays, there is a reluctance to agree that this will be possible, at least in the near future. Scientific efforts are continuing to be focussed on the development of more precise, reliable and less cumbersome assay methods. This paper presents an overview of the strengths and limitations of bioassays as used in quality control, followed by a discussion of specific biological products as models for these principles.

Biological Assay↗
PubMed1986

The reduction of the number of animals used in the biological assay of insulin.

The biological control of insulin is vital as it is administered daily to a large proportion of the population during the major part of their lives. The development of the biological assay of insulin will be described with the progressive evolution of methods eventually to dispense with the need for animals. From the quantal Mouse Convulsion Method using around 600 mice per sample to the quantitative Mouse Blood Glucose method using an average of 120 mice per sample in which the fall in the blood glucose levels is used to estimate the potency of insulin by its hypoglycaemic effect. This was followed by the development of the in vitro Radioreceptor Method which is a procedure based on competition between the binding of insulin and [125I]-insulin to cells of the cultured human IM-9 cell line. The production of highly purified insulin by the Pharmaceutical Industry has made possible the recent introduction of new High Performance Liquid Chromatography technology.

Animal Testing Alternatives↗
PubMed1990

A validated HPLC assay for salmon calcitonin analysis. Comparison of HPLC and biological assay.

A high-performance liquid chromatographic (HPLC) method is described for the assay of salmon calcitonin. The method uses a 5-microns octadecasilyl silica column (100 x 4.6 mm) at 50 degrees C and an initial mobile phase (flow rate 1 ml min-1) comprising 35% of B (1 M tetramethylammonium hydroxide-water-acetonitrile, 8:392:600) and 65% of A (1 M tetramethylammonium hydroxide-water-acetonitrile, 20:880:100) with linear gradient elution over 21 min to a final mobile phase of 57% B; solutions A and B are adjusted to pH 2.5 with phosphoric acid. Detection was by UV spectrophotometry at 210 nm. The method has been shown to be selective, precise and rapid and, in a collaborative study to give excellent correlation with the results obtained by using the biological assay method of the European Pharmacopoeia. The method, which has been applied successfully to the assay of different batches of salmon calcitonin in bulk drug and in formulated products, is recommended for adoption as the pharmacopoeial assay method.

Amino Acid Sequence↗
PubMed1988

Comparison of relevant biological assays for the determination of biological active erythropoietin.

Human recombinant erythropoietin (rh EPO), a glycoprotein hormone which is an obligatory growth factor for the proliferation and differentiation of committed erythroid progenitor cells, has been purified to homogeneity and compared to human urinary erythropoietin (EPO). Erythropoietin levels will be determined and standardized by in vivo bioassays in which endogenous erythropoietin production has been reduced by hypertransfusion or hyperbaric atmosphere. The effect of EPO on the rate of red cell production or Fe59 incorporation is used as measure of its erythropoietin content. Both in vivo assay systems will be compared with respect to standardization for routine laboratory use. For in vitro characterization of EPO the classical assay for Fe59 incorporation in in vitro rat bone marrow cells will be compared to the proliferation and H3 Thd uptake by treatment with phenylhydrazin enriched erythroid progenitors from mouse spleens. (The direct physiological effect of EPO on stem cells will be shown by differences in BFUe progenitor levels). Rh EPO is jointly developed by Integrated Genetics (Boston) and Behringwerke AG (Marburg).

Animals↗
PubMed2000

An automated biological assay to determine levels of the trypanocidal drug melarsoprol in biological fluids.

For the investigation of the pharmacokinetic properties of a drug, methods for sensitive and precise quantification are a prerequisite. Only few functional methods exist for the determination of the trypanocidal drug melarsoprol in biological fluids: A bioassay which requires microscopical evaluation and two HPLC methods, which require sample extraction and are difficult to automatize due to the drug's properties. We report the development of an automated biological assay, based on the fluorescent dye Alamar blue. To validate the assay for melarsoprol, 108 serum and 37 cerebrospinal fluid (CSF) samples were spiked with melarsoprol at concentrations of 17-92 ng/ml for CSF and 17 ng/ml-2.2 microg/ml for serum. The precision (repeatability) expressed as the interday average coefficient of variation was 9.9% for serum and 18.8% for CSF samples over the respective concentration range. The accuracy (measurement for the systematic error) of the test was 99.4% for serum and 96.4% for CSF. The assay's limit of quantitation with the use of the trypanosome stock STI 704 BABA was 4 ng/ml for both serum and CSF samples.

Animals↗
PubMed2002

[Study on the biological assay of Herba Leonuri--analysis the dosage response curve of Herba Leonuri and oxytocin and establishment of adequate potency pattern].

OBJECTIVE: To establish the effective patten of Herba Leonuri to be suitable for biological assay. METHODS: By comparing the dosage-effect curve of Herba Leonuri and oxytocin the suitable effective pattern was set up. RESULTS: The experiment suggest that the uterus contract height from 20 mm to 85 mm is the adequate effective range. In this range, the effect both Herba Leonuri and oxytocin should plot as a straight line against the log dose and two lines are basically parallel. CONCLUSION: In the light of establishing effective pattern, the biological assay of Herba Leonuri may pattern the method of oxytocin biological assay to regard oxytocin as standard. The result error of Herba Leonuri assay is under 20%, not exceed the demand limits of biological assay.

Animals↗
PubMed1996

Survey and assessment of mammalian estrogen biological assays for hazard characterization.

With the growing awareness and concern regarding estrogens in the environment, the selection of reliable and appropriate methods for their detection and characterization has taken on considerable importance. The relevant literature covering the period from 1920 to 1996 was surveyed to identify methods that have been used to assay estrogens in mammalian systems. The estrogen biological assays identified were grouped into four categories: (1) reproductive tract response; (2) non-reproductive-tract target tissue response; (3) estrogen receptor binding; and (4) estrogen receptor-dependent transcriptional expression. The biological assays were summarized and their advantages and disadvantages discussed. A possible testing scheme also was provided to characterize estrogens, anti-estrogens, and pro-estrogens (chemicals metabolically converted to estrogens)..

Animals↗
PubMed1998

Biological assay for the detection of metallo-beta-lactamases in Bacteroides fragilis.

A biological assay was developed for the detection of carbapenemases, particularly metallo-beta-lactamases, in Bacteroides fragilis. The isolates tested possessed the gene (cfiA) responsible for metallo-beta-lactamase production, and showed reduced susceptibility to imipenem. Carbapenemase activity was investigated spectrophotometrically and by a biological assay in which sonicates of bacterial cells were mixed with imipenem in wells cut into Isosensitest agar inoculated with an Escherichia coli indicator organism. After incubation, zones of inhibition were measured. Reductions in zone size compared to a beta-lactamase-negative control, indicating carbapenemase production, were observed with all strains that exhibited hydrolysis of imipenem when measured spectrophotometrically, and with one isolate in which activity was not detected by spectrophotometry. Inclusion of EDTA in the well mixtures abolished the reduction in zone size, indicating the presence of metallo-beta-lactamase. This simple method can detect weak carbapenemase activity that may be overlooked by spectrophotometry.

Bacterial Proteins↗
PubMed1976

A new biological assay method for histamine-sensitizing factor using survival time as a response.

A new biological assay method using survival time of mice as a graded response after histamine challenge has been developed for the histamine-sensitizing factor of pertussis bacilli. The method is relatively precise and reproducible in estimation and fairly sensitive in the validity tests of biological assay. Effect of endotoxin on the estimation by the proposed method was also investigated in case the method is applied to the control test of pertussis vaccine.

Animals↗
PubMed1999

Gonadorelin-induced testosterone release: a biological assay for quality assurance of gonadorelin in veterinary medicine.

Two experiments were conducted with bulls administered norgestomet and gonadorelin to determine if the gonadorelin-induced release of testosterone could be developed into a biological assay for quality assurance of gonadorelin. Implants containing norgestomet (0 to 36 mg) reduced the episodic release (r = -.81; P < .05) and mean concentrations of testosterone (r = -.82; P < .05). Gonadoreline-induced testosterone release increased (r = .99; P < .05) with increasing dosage of gonadorelin (up to 5 micrograms) in norgestomet-implanted bulls (36 mg). Maximal testosterone was released (> sixfold increase) with 5 to 40 micrograms of gonadorelin. In summary, the gonadorelin-induced testosterone release in bulls administered a synthetic progestin is a sensitive (0.008 microgram per kg body weight for 5 micrograms of gonadorelin) biological assay with a rapid turnaround time for the confirmation of gonadorelin potency. Based on a per-kg-body-weight basis, the norgestomet-treated bull is the most sensitive biological assay model.

Animals↗
PubMed1995

Biological assays for Ras transformation.

The rodent fibroblast systems described above have provided sensitive and rapid biological assays to characterize the properties of normal and mutated Ras proteins. Furthermore, these assays have provided in vitro systems to measure the ability of other cellular components to modulate Ras signal transduction and transformation. However, while these assays provide an excellent measure of Ras-transforming activity, the fact that these cells are of fibroblastic origin, and can be transformed by a single hit, indicates that caution should be used in extrapolating observations from NIH 3T3 transformation assays to the situation in human tumors. Therefore, using human epithelial cell-based assays that more closely approximate the cell types where mutated ras alleles are most frequently detected may provide more realistic assays for examining the biochemical and biological consequences of aberrant Ras function in human tumors. Nevertheless, despite these cautions, these rodent transformation assays will continue to be the best and most widely applied assays for Ras biological activity.

3T3 Cells↗