A specific and sensitive sandwich enzyme immunoassay for human chorionic gonadotropin using antibodies against the carboxyl-terminal portion of the beta-subunit.
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Biomedical subjects
Publications and source records attributed to S Iwasa.
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A simple and sensitive radioimmunoassay procedure is described for the screening and detection of specific antibodies in hybridoma cell lines. The specific procedure was developed to screen for antibodies against human thyrotropin (hTSH), but the procedure is applicable to screening for any desired antibodies. The immunoglobulin G(IgG) fraction of goat anti-mouse IgG is used to coat wells of microtiter plates. Anti-hTSH antibodies are measured by incubating antiserum dilutions in the coated wells and detecting the bound IgG with radioiodinated hTSH. Unlabeled hTSH may also be detected by its ability to inhibit binding of 125I-hTSH to the coated wells. This assay technique meets the demands of simplicity, sensitivity, reproducibility, and rapidity as a screening assay of hybridoma cell lines capable of secreting anti h-TSH.
In order to investigate the validity of an enzyme immunoassay for glucagon, the glucagon levels of human plasma were determined by both enzyme immunoassay (EIA) and radioimmunoassay (RIA). After a glucose load, plasma glucagon measured by both EIA and RIA fell in 12 normal subjects. The glucagon levels measured by both assays during glucose tolerance test showed good agreement in a group of 10 patients. After arginine infusion, plasma glucagon increased in 6 normal subjects and 3 patients and glucagon values measured by EIA correlated well with those by RIA. The present study demonstrates correlation between glucagon levels measured by RIA and EIA and indicates the usefulness of EIA for determining glucagon in human plasma.
ACTH activity in glacial acetic acid extracts of normal rat tissues was studied by both ACTH RIA and a sensitive in vitro bioassay. ACTH immunoactivity was found in all tissues: brain, 278 +/- 54 (mean +/- SE; picograms per mg protein); stomach, 59 +/- 4; kidney, 47 +/- 3; colon, 40 +/- 4; small intestine, 37 +/- 4; liver, 18 +/- 2; and heart, 16 +/- 3. Tissue ACTH showed parallelism with ACTH standard in the RIA. No correlation existed between tissue ACTH and plasma ACTH in normal rats. Dexamethasone treatment (0.4 mg/day for 5 days) suppressed plasma ACTH, but did not affect tissue ACTH levels. When tissue extracts were passed through Sephadex G-75-SF columns, ACTH immunoactivity was exclusively eluted in the portion of bigger molecular weight than ACTH standard, except in the brain. Based on this column chromatography, the molecular weight of the main peak of activity was estimated as 26,000. Tissue ACTH-like material contained no detectable biological activity (less than 2 pg/100 ng tissue). However, biological activity was easily detectable after exposure of the tissue extracts to trypsin. When studied by immunoassay and bioassay, this 26,000 mol wt ACTH was digested and cleaved to 4,500 mol wt and biologically active ACTH with trypsin treatment. Tissue ACTH immunoactivity does not seem to be the result of artifacts: 1) extracts were adjusted to pH 8.0 and a common osmolality (150 mosmol/liter) before assay; 2) protein contents in RIA tubes were only 0.1-1.6 mg; 3) tissue extracts incubated with [125I]iodo-ACTH for 48 h produced less than 5% damage of labeled hormone, as assessed by moderate excess of antibody binding; 4) enzyme inhibitors did not modify tissue ACTH levels; and 5) ACTH immunoactivity of tissue extracts was absorbed by anti-ACTH immunocolumns. We conclude that high molecular weight ACTH-like materials are widespread in normal rat extrapituitary tissues and are probably a precursor form of 4500 mol wt ACTH.
A method has been developed for quantitative determination of the early appearing mouse paw swelling activity of pertussis vaccine. Mice were inoculated with the vaccine into the left hind paws. The difference in the thicknesses between the inoculated and the uninoculated paws was taken as the swelling response in 16 hr after inoculation. It was transformed into logarithm as a response metameter. A linear log dose-log response regression line was obtained over a relatively wide range of doses of the vaccine. No deviation from parallelism was significant among the regression lines of different vaccines tested. The swelling activities relative to that of a reference vaccine of diphtheria-pertussis-tetanus combined (DPT) vaccines recently produced in Japan were determined. The relative activities ranged from 0.6 to 2.5, being twice the mean width of the 95% confidence interval of the relative activity. Further experiments showed that the activity significantly correlated with endotoxin and histamine-sensitizing factor (HSF) but not with lymphocytosis-promoting factor (LPF). In addition, the multiple regression analysis of such relationship suggested that the swelling activity is accounted for by the combined action of endotoxin and HSF. A model experiment with a mixture of the two toxins supported this conclusion.
T-1982 (cefbuperazone) concentrations in antecubital venous blood and pelvic dead space exudate were examined in 4 patients who had received radical hysterectomy due to uterocervical cancer. Data analysis for the transfer of T-1982 into pelvic dead space exudate was performed with the stimulation curves prepared from pharmacokinetic parameters by the three-compartment model. When T-1982 was given at a dose of 1 g, the peak level in the venous blood was 83.7 micrograms/ml at 1 hour after the start of administration. With regards to T-1982 concentration in pelvic dead space exudate, the peak level of 19.3 micrograms/ml was observed at 2.24 hours after the start of administration and relatively high concentration of about 6.1 micrograms/ml was observed even at 8 hours after the start of administration. From the above results, it is concluded that T-1982 is a useful drug for the treatment of infections in the field of obstetrics and gynecology.
The effect of lymphocytosis-promoting factor (LPF) on antibody response in mice was estimated under different sets of experimental conditions. Four- and 6-week-old mice were intravenously inoculated with LPF. Three days later these mice were inoculated either intraperitoneally or intravenously with sheep red blood cell (SRBC) or human serum albumin (HSA) as an antigen. The adjuvant effect of LPF was demonstrated on antibody response in 6-week old mice to intraperitoneally inoculated SRBC but not to intravenously-inoculated one. When 4-week-old mice were immunized, hemagglutinin production in response to intraperitoneally inoculated SRBC was not enhanced by LPF. In addition, a rather suppressive effect of LPF at a comparatively high dose was demonstrated on hemagglutinin production in response to intravenously inoculated SRBC. Anti-HSA production was enhanced by inoculation of LPF in any combination of the mouse age and the route of antigen administration. These findings indicate that the adjuvant effect of LPF on antibody response in mice depends upon experimental conditions: the age of mice, the quality of antigen and the route of antigen administration used for immunization.
The study group was organized to evaluate the usefulness of cefmenoxime (CMX) injection, a new synthetic cephalosporin, for the treatment of infections in the field of obstetrics and gynecology. Fundamental and clinical studies were made by the society and the following results were obtained. 1. The peak distribution of CMX's MIC for E. coli, Klebsiella sp., Enterobacter sp., Bacteroides sp. and Peptococcus sp. isolated from obstetrical and gynecological infections with relatively high frequencies area 0.1, less than or equal to 0.05, 0.2, 3.13, 1.56 micrograms/ml, respectively, with an inoculation of 10(6) cells/ml. 2. When 1 g of CMX is administered by intravenous drip infusion for 1 hour, the maximum concentrations in various tissues of female genital organs were as follows: 14.2 and 13.2 micrograms/g in ovary and oviduct, respectively, at 1.20 hours after the start of administration, and 16.9 and 26.3 micrograms/g in corpus uteri and cervix uteri, respectively, after 1 hour. As for the transfer to the exudate in the pelvic dead cavity, the peak concentration was 15.6 micrograms/ml after 2.13 hours. 3. In the clinical studies, CMX was given to 258 cases with female genital organ infections and others. As for the clinical effects, with exclusion of 3 cases in which other antibiotics are concomitantly used, responses were excellent in 76 cases, good in 162 cases and poor in 17 cases, among 255 cases in total. The efficacy rate was 93.3%. The efficacy rates by diseases were 97.1% (68/70) for intrauterine infections, 88.8% (79/89) for intrapelvic infections, 98.4% (62/63) for adnexitis, and 100% (23/23) for infections of external genital organs. As for the clinical effects on causative bacteria, the efficacy rates were 100% (19/19) for single infections due to Gram-positive bacteria, 94.8% (55/58) for single infections due to Gram-negative bacteria, and 88.2% (15/17) for single infections due to anaerobic bacteria. And its efficacy rates were 89.6% (69/77) for mixed infection cases. Side effects were observed in 2 cases (0.8%); 1 case with eruption, and 1 case with diarrhea and vomiting. As for abnormal laboratory findings, lower white blood cell count was observed in 2 cases and elevation of the values regarding hepatic functions in 9 cases. All cases were returned to the normal after the completion of the administration. Cefmenoxime showed a satisfactory clinical efficacy and a potent bacteriological effect in treatment of the infections in the field of obstetrics and gynecology, and it has been concluded that cefmenoxime will be useful addition to the antibiotics for the therapy of these infections.
This paper, is concerned with fundamental and clinical studies of ceftizoxime, a newly developed cephalosporin derivative, in the field of obstetrics and gynecology. 1. Concentrations of ceftizoxime after administration 1 g of ceftizoxime by 1 hour drip infusion were determined in genital organs in 17 patients and the exudate of pelvic dead space in 6 patients. Simulated maximal concentrations with the ratios to the simulated peak serum levels were as follows: 27.9 micrograms/g for fundal myometrium with the ratio of 48%, 36.0 micrograms/g for portio vaginalis with 62%, 17.1 micrograms/g for ovary with 29%, 15.0 micrograms/g for oviduct with 26% and 16.2 micrograms/ml for the exudate of pelvic dead space with 30%. 2. Minimal inhibitory concentrations of ceftizoxime were determined against clinically isolated organisms from female genital infectious diseases. Ceftizoxime was found to have a potent in vitro activity against Gram negative bacilli; for example, 0.1 microgram/mg or low against E. coli and K. pneumoniae. Against P. aeruginosa, P. cepacia and b. fragilis, ceftizoxime had an activity which expected to be effective in the clinical use. 3. We gave ceftizoxime to 6 patients comprising 4 patients with puerperal fever, 1 with septic abortion and 1 with tubo-ovarian abscess in daily doses of 2 to 3 g by b.i.d or t.i.d intravenous drip infusion for 4--12 days. The results of the treatment were 'excellent' in 3 patients, 'good' in 2, and 'unevaluatable' in 1. 4. Adverse reactions occurred in 2 patients who showed eruption during the medication with ceftizoxime. These patients had allergic histories due to penicillin derivatives. From the above results it is concluded that ceftizoxime is a useful drug for infections in obstetrical and gynecological field.
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Ten cases of gynecological infection were treated successfully by a new cephalosporin derivative, cefotaxime (HR 756, CTX), which proved excellent in 4 cases and good in 6 cases. No adverse reaction was found to be induced by administration of this drug. Post-administration results were all normal for both renal and hepatic function tests. It is extremely difficult to accurately assess bacteriological efficacy of a drug in treatment of female genital infections. Nevertheless, we determined its MICs for a few number of strains we could isolate from clinical cases. Its MIC against 4 strains of B. fragilis inoculated at 10(8) cells/ml was 25 approximately 50 mcg/ml and was 1.56 approximately 3.13 mcg/ml at 10(6) cells/ml inoculation. Its MIC against 2 strains of Ps. cepacia was 12.5 mcg/ml at 10(8) cells/ml inoculation and 6.25 mcg/ml at 10(6) cells/ml inoculation. These MICs suggest that this drug is a very promising antimicrobial agent for treatment of gynecological infections, as been already indicated by clinical results of this drug.
A highly specific enzyme immunoassay for determining hCG was established by using beta-D-galactosidase as label. In order to increase the specificity of the assay, an antiserum against whole hCG was purified on a column of hCG beta carboxyl-terminal peptide (residues 123-145) covalently linked to Sepharose 4B. The antibody (N101S) thus prepared showed a weak cross-reactivity with human LH in an assay using hCG-enzyme conjugate, but the slight cross-reactivity was virtually avoided when an hCG beta carboxyl-terminal peptide was used as a peptide in the enzyme conjugate. N101S antibody was compared with antiserum (B1B) directed against a carboxyl-terminal peptide (123-145). In hCG measurement N101S gave about 30 times higher sensitivity than B1B, although the former antibody was less sensitive to carboxyl-terminal peptides of hCG beta. The enzyme immunoassay using a combination of N101S antibody and a carboxyl-terminal peptide (130-145)-enzyme conjugate was able to detect as little as 0.25 mIU of hCG without the interference of LH. The performance and validity of this assay were comparable to those of conventional radioimmunoassay.
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Formalinized chick erythrocytes agglutinated with Japanese encephalitis virus antigens over a wider range of pH (6.0-7.2) than fresh erythrocytes (pH 6.4-6.8). The virus antigens were unstable below pH 7.0 and therefore the use of the formalinized erythrocytes made it possible for a one-diluent system of the hemagglutination-inhibition tests to be used. In these tests phosphate-buffered saline at pH 7.0 was used throughout as a diluent for serum, antigen and erythrocytes, although the conventional system, using fresh erythrocytes, requires two buffers of different pHs, one an alkaline diluent for serum and antigen and the other an acidic diluent for erythrocytes.
We have developed a simple and sensitive chemiluminescence-linked immunoassay (CLIA) for determining mumps virus antibodies. Luminol molecules were used as markers, and polystyrene balls were used as antigen carriers. The CLIA was compared with an enzyme-linked fluorescence assay and a hemagglutination inhibition test on a total of 40 serum specimens obtained from 29 donors with natural infection or vaccination. There was good correlation between the three methods, and the sensitivity of the CLIA was about 10 times higher than that of the hemagglutination inhibition test, although it was slightly inferior to that of the enzyme-linked fluorescence assay. Moreover, the time course of light emission from the labeled antibody was rapid, and therefore in the CLIA the quantitation of the marker takes only a short time.
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An enzyme immunoassay of pancreatic glucagon was established by using E. coli beta-D-galactosidease [EC 3.2.1.23] as a marker. In order to increase the sensitivity of the immunoassay, different peptides obtained from glucagon fragments were used to produce the enzyme conjugate and the immunogen. Antiserum N6E raised against C-terminal fragment peptide (15-29) could be diluted to more than 1 : 100,000 in the assay and was highly specific for pancreatic glucagon. The antiserum reacted well with the C-terminal fragment peptide (21-29) as well as another fragment peptide (15-29) and pancreatic glucagon. The enzyme immunoassay using antiserum N6E and fragment peptide (21-29)-enzyme conjugate could detect as little as 1 to 2 pg of glucagon. The mean recovery of glucagon added to serum specimens was 104% and the coefficients of variation were 3.7-14.5% (within assay) and 9.0-18.5% (between assay).