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C B Reimer

Publications and source records attributed to C B Reimer.

At least 55 records · Page 3Linked to original sources
PubMed1984

Phase I study of intravenous gamma globulin in multiple myeloma.

Seventeen patients with multiple myeloma were given intravenous immunoglobulin at doses ranging from 150 mg/kg to 500 mg/kg in a phase I study. The intravenous immunoglobulin was well tolerated with only three transient episodes of mild clinical toxicity during 27 infusions. In no instance was hepatic or renal toxicity seen. Marked biologic variability over the one month study period in total IgG levels in patients with non-IgG myeloma and IgG subclasses in many of the patients was observed, making intravenous immunoglobulin half-life determinations based on IgG or IgG subclass levels problematical. The decay of functional antibody to hepatitis B surface antigen was determined. Analysis of the hepatitis antibody data suggested that intravenous immunoglobulin half-life was in the range of seven to 20 days for the entire study group and was not related to the isotype of the myeloma paraprotein or to the baseline levels of IgG. No infections were observed in the study group during the study period, but the potential for infection prophylaxis by intravenous immunoglobulin in myeloma patients must be evaluated in a randomized, prospective, controlled phase III study.

Adult↗
PubMed1984

Clinical interpretation of maternal serum alpha-fetoprotein concentrations.

Concentrations of maternal serum alpha-fetoprotein provide the basis for decisions to proceed to ultrasonography and amniocentesis in the multistaged screening/diagnostic process used for the prenatal detection of open neural tube defects, abdominal wall defects, and twins. The concentration of maternal serum alpha-fetoprotein at or above which women should be advised that amniocentesis is available (cutoff levels for amniocentesis) varies, depending upon a number of factors, such as maternal weight, race, residence, and gestational age. We briefly describe a methodology for computing the predicted risks of fetal conditions associated with a given concentration of maternal serum alpha-fetoprotein adjusted for important variables. This adjustment methodology provides a straightforward means for clinical laboratories to report results of assays of maternal serum alpha-fetoprotein in terms of predicted risks, to facilitate understanding by the physician and patient of the clinical meaning of the results of maternal serum alpha-fetoprotein testing.

Amniocentesis↗
PubMed1984

Application of a solid-phase immunofluorometric assay to the selection of monoclonal antibody specific for the adenovirus group-reactive hexon antigen.

An immunofluorometric assay (IFMA) has been evaluated as a screening assay to detect monoclonal antibodies to the group-specific antigen of the adenovirus hexon component. The antibodies were produced as mouse ascitic fluids from hybridoma cells generated from Balb/C mice immunized with purified adenovirus type 2 hexon component and crude adenovirus type 3 culture supernatants. The purified IgG fractions from all monoclonal ascitic fluids tested were identified as the IgG1 K mouse isotype. Antibody titers ranged from 102,400 to 204,800 by the IFMA, from 200 to 12,800 by indirect FA, and were generally nonreactive in counterelectrophoresis, complement fixation, hemagglutination-inhibition, serum neutralization, and immune electron microscopy titrations. The IFMA is a reliable method for quantitating low levels of specific antibody in large numbers of test samples, and is therefore ideal as a screening assay for monoclonal antibody in tissue culture fluids and in mouse ascitic fluids.

Adenoviruses, Human↗
PubMed1984

Evaluation of thirty-one mouse monoclonal antibodies to human IgG epitopes.

Stable clones of 31 mouse hybridomas that produce monoclonal antibodies (MAbs) against human IgG antigenic determinants were obtained. The number of hybridomas of different specificity described are: 2 anti-IgG1 Fc, 1 anti-IgG2 Fc, 1 anti-IgG2 Fd, 2 anti-IgG3 Fc, 2 anti-IgG3 hinge, 3 anti-IgG4 Fc, 3 anti-IgG4 Fd, 2 anti-nG4m(b), 4 anti-IgGFc, 2 anti-IgGFd, 1 anti-kappa, 1 anti-lambda, 1 anti-non IgG1, 2 anti-non IgG2, 2 anti-non-IgG3, 2 anti-non-IgG4. Evidence is presented validating their specificity. Some MAbs demonstrated to be avid, potent, and specific for well defined IgG-subclass epitopes may be partially or completely inactive in other assay systems, presumably because of different presentations of antigen epitopes. In general, this problem requires careful writing of protocols describing the use of MAbs.

Animals↗
PubMed1984

Detection of IgG-associated determinants in reduced and alkylated preparations of human IgG3 by monoclonal antibodies.

Using classical typing antisera, previous experiments have failed to demonstrate IgG3 in partially reduced and alkylated preparations of human IgG intended for intravenous application (IGIV). To establish that IgG3 is actually present in such preparations, we designed an enzyme-linked immunosorbent assay (ELISA) using monoclonal antibodies as solid-phase reagents and protein A-purified IgG3 as antigen. Three different samples of reduced and alkylated antigen were used: (1) IgG3 isolated from a ready-for-infusion IGIV; (2) IgG3 which was purified from an intramuscular (Cohn fraction II) IgG solution before being subjected to a mild reduction and alkylation procedure, and (3) completely reduced and alkylated IgG3. The reduction and alkylation procedure did not affect the solubility of IgG3, indicating that IGIV prepared in this manner should contain normal quantities of IgG3. In the ELISA, solid-phase monoclonals which were cross-reactive with multiple IgG subclasses clearly reacted with reduced and alkylated IgG3. Furthermore, there was no substantial difference between the quantities of modified and native antigen required for 50% maximal ELISA signal. In contrast, solid-phase monoclonals with IgG3-restricted specificity did not recognize reduced and alkylated material. These results indicate that IGIV prepared by reduction and alkylation has a normal IgG3 content and confirm that some IgG3-specific determinants are altered by the modification procedure.

Alkylation↗
PubMed1983

Detection and characterization of mouse monoclonal antibodies to epidemic typhus rickettsiae.

A solid-phase immunofluorometric assay was used to detect mouse monoclonal antibodies to epidemic typhus rickettsiae, Rickettsia prowazekii (the immunizing antigen), and to murine typhus rickettsiae, Rickettsia typhi, a related antigen. Of the 649 hybridoma cultures obtained, 628 contained antibodies either to R. prowazekii or to both R. prowazekii and R. typhi. A total of 72 cultures were cloned by limiting dilution and yielded 137 antibody-producing clones. Of these, 104 produced antibodies specific for R. prowazekii, 22 produced antibodies that reacted with R. prowazekii and R. typhi, and 11 produced antibodies that reacted with R. prowazekii, R. typhi, and R. canada. The immunoglobulin isotypes of the mouse monoclonal antibodies produced were identified by a related indirect immunofluorometric assay technique with fluorescein isothiocyanate-conjugated antisera specific for each isotype. Antibodies were also evaluated by indirect fluorescent antibody tests, and antibodies from selected clones were found to neutralize rickettsial toxic activity in mice.

Animals↗
PubMed1982

Immunoglobulin M and G antibody response to type- and subtype-specific antigens after primary and secondary exposures of mice to influenza A viruses.

A mouse model of influenza infection was studied to help define parameters that may affect serodiagnosis of human infections by immunoassays. Antibodies to both type- and subtype-specific influenza A antigens were measured by a solid-phase immunofluorometric assay. Dilute mouse sera were added to purified influenza virus that had been covalently bound to polyaminostyrene microbeads, and the bound antibody was detected by fluorescein isothiocyanate-labeled isotype-specific antisera. Results were consistent in that upon exposure of mice by either infection alone or by vaccination after infection, both immunoglobulin M (IgM) and IgG antibodies reactive with newly encountered subtype specific viral antigens were measured. IgG antibody was usually detectable by the solid-phase immunofluorometric assay several days before it could be detected by a hemagglutination inhibition test. Increased levels of antibody of the IgG1, IgGa, IgG2b, and IgG3 subclasses were also measured during influenza infection. Surprisingly, response to type-specific viral antigens was of the IgG class in primary as well as in secondary exposure. The results suggest that for serodiagnosis of influenza infections by detection of specific IgM antibody, the assay should use subtype-specific antigens.

Animals↗
PubMed1982

Evaluation of a solid-phase immunoassay with fluorescein isothiocyanate-conjugated heterogeneous or monoclonal antibodies for identification of virus isolates, with influenza virus as a model.

A solid-phase immunofluorescence assay was evaluated for the identification of viruses isolated in tissue culture, with influenza virus as a model. Purified immunoglobulin G (IgG) from hyperimmune rabbit sera specific for contemporary strains of influenza A or B was covalently attached to microscopic plastic beads to capture virus. Fluorescein isothiocyanate (FITC)-conjugated antibodies of different specificities were then reacted with bound antigen, and the resulting complexes were quantified in a suitable filter fluorometer. The assay, with appropriately absorbed FITC-conjugated second antibody, reliably identified virus present in harvests from cell cultures infected with clinical specimens. For influenza A (H1N1) virus, sensitivity of detecting antigen was about 8- to 32-fold less when an FITC-conjugated monoclonal Igg antibody pool specific for epitopes in three different antigenic sites on influenza hemagglutinin was used as the second antibody as compared to when IgG from hyperimmune sera specific for virus or its components was used as the second antibody. The immunofluorometric assay provides a method for quantitative detection of viral antigen in tissue culture fluids and objective identification of virus type and subtype with FITC-conjugated reagents.

Animals↗
PubMed1982

Characterization of antibody responses in legionellosis with an immunofluorometric assay.

A solid-phase immunofluorometric assay was used to qualitatively characterize and precisely measure human immunoglobulin class-specific antibody responses in legionellosis. Stable antigen preparations consisted of cells grown at 25 degrees C that were killed, fixed with Formalin vapors, washed, and lyophilized. Working-curve material consisted of dilutions of selected convalescent sera. Linear regressions of logit transformations of relative fluorescence intensities versus the logarithm of the relative concentrations of sera were determined to give immunoglobulin class-specific antibody levels from uninfected and infected individuals. Each fluorescence intensity obtained with immunoglobulin class-specific antibody was converted to a multiple of the median fluorescence intensity obtained with sera from uninfected individuals. A presumptive-positive acute-phase legionellosis serum was defined for each immunoglobulin class by a multiple of the normal median fluorescence intensity that was greater than the multiple of the normal median from approximately 97% of the uninfected population.

Antibodies, Bacterial↗
PubMed1981

Alpha fetoprotein screening and diagnosis of fetal open neural tube defects: the need for quality control.

A workshop, held in May, 1978, at the National Institute of Child Health and Human Development, considered the quality control of reagents and assays for measuring alpha fetoprotein (AFP) in maternal serum and amniotic fluid for the antenatal screening and diagnosis of open neural tube defects. The recommendations, published in detail elsewhere and summarized in this article, were based on what was known to be readily achievable and on estimates of the effect of assay performance on screening and diagnostic sensitivity and specificity. Main points considered included: (1) choice of units for AFP measurement and interpretation, (2) need for National AFP Reference Preparations and the need for a scientific panel to assess the adequacy of these reference materials, (3) information needed from reagent manufacturers, (4) criteria for assay performance, (5) biological sources of reagents, (6) need for laboratory and epidemiologic monitoring, and (7) need for a minimum assay workload.

Amniotic Fluid↗
PubMed1981

Effect of test system on the ability of monoclonal antibodies to detect antigenic drift in influenza A(H1N1) virus haemagglutinins.

Results of analysing antigenic variation in the haemagglutinin (HA) molecule of naturally occurring influenza A (H1N1) viruses from 1977 to 1979 with monoclonal antibodies were found to be dependent in some instances on the test system used. In several instances A/USSR/90/77 HA-specific monoclonal antibodies had sharply reduced haemagglutination-inhibition (HI) titres with variant virus although they bound to the variant and A/USSR/90/77 HAs with similar efficiencies as judged by titration in a sensitive and accurate solid-phase immunofluorimetric assay. In another instance, the converse situation was observed: monoclonal antibodies having a reduced efficiency of binding to the HA of a variant virus nevertheless had comparable HI titres with the variant and with A/USSR/90/77. The chemical basis and epidemiological significance of these observations remain to be elucidated. Nevertheless, the finding that the reaction of monoclonal antibodies can, in some cases, be markedly dependent on the test system employed is of significance for the efficient design and correct interpretation of immunochemical studies which employ monoclonal antibodies to investigate the basis for variation in influenza strains.

Antibodies, Monoclonal↗
PubMed1980

Quantitative characterization of specificity and potency of conjugated antibody with solid-phase, antigen bead standards.

An immunofluorescent assay was used to characterize precisely the potency and specificity of fluorescein-conjugated immunoglobulin class-specific and polyvalent anti-sera. Stable antigen standards consisted of highly purified immunoglobulin antigens covalently bound to polyaminostyrene beads. Linear regressions of weighted logit transformations of relative fluorescent intensities versus the logarithm of relative conjugate concentrations were determined. The potency of conjugates was compared using two different methods derived from the logit transformation. Inappropriate specificities were measured in some conjugates described as immunoglobulin 'class-specific'.

Antibodies, Anti-Idiotypic↗
PubMed1980

Detection of monoclonal influenza antibodies synthesized in culture by hybridoma cells with a solid-phase indirect immunofluorometric assay.

A solid-phase indirect immunofluorometric assay for measuring reactions of mouse monoclonal antibodies with antigen has been developed, with influenza virus as a model. Purified IgG from hyperimmune rabbit sera is covalently linked to polyaminostyrene beads, to which influenza viruses are then bound immunologically to make solid-phase antigens. Alternatively, the virus is covalently coupled directly to the beads. Mouse antibodies, produced by hybridoma cells in culture, are reacted with constant amounts of solid-phase antigens, and then indirectly quantitated by adding FITC-labeled antimouse Ig and measuring the fluorescent intensity with a filter-fluorometer. The assay system permits rapid screening for low levels of antibodies synthesized by hybridoma cells in culture. It is about 25- to 150-fold more sensitive than hemagglutination inhibition tests in detecting monoclonal antibodies reactive with influenza virion HA protein.

Animals↗