ABSTRACT
A competitive ELISA method is described for the measurement of total antibodies to the capsular polysaccharide of Haemophilus influenzae type b (HibCPS) in human sera. The competitive method showed an excellent correlation to the radioantigen binding assay (RABA, or Farr assay) and improved correlation of sera with low titers with respect to the more conventional noncompetitive method. Overestimation of samples in the low concentration range was no longer observed with the competitive ELISA method. The free HibCPS competition allowed us to eliminate the day-to-day background variation typical of some sera; thus, only values representing the true anti-HibCPS response were determined. The use of precoated microplates, which could be stored up to 8 months, greatly improved the speed of the procedure. An overall correlation coefficient of 0. 9660 was found when 407 serum samples with a wide variety of anti-HibCPS antibody levels were tested with the competitive ELISA and RABA. The regression line was very close to the ideal line, with a slope of 1.0045 and an intercept of -0.1996. A subset of 96 serum samples representative of all pre- and postimmunization samples was used to compare the competitive ELISA with a previously described ELISA method. The competitive method performed in two laboratories in different countries showed a better correlation with the RABA. The correlation factors were 0.9770 and 0.9816, respectively, while a factor of 0.9547 was found with the previously described noncompetitive procedure, which was better for this method than previously reported (r = 0.917). Therefore, the competitive ELISA is proposed for the assay of anti-HibCPS titers in sera from vaccinated subjects.
Subject(s)
Antibodies, Bacterial/blood , Enzyme-Linked Immunosorbent Assay/methods , Haemophilus Infections/immunology , Haemophilus Vaccines/immunology , Haemophilus influenzae type b/immunology , Adult , Haemophilus Infections/prevention & control , Humans , Infant , Infant, Newborn , Polysaccharides, Bacterial/blood , Radioimmunoprecipitation Assay/methods , Vaccines, Conjugate/immunologyABSTRACT
The cytogenetic effects of three benzimidazoles, i.e., benomyl, methyl thiophanate and methyl 2-benzimidazolecarbamate (MBC), were studied in mouse bone marrow cells by analyzing three genetic endpoints: micronuclei, structural chromosome aberrations plus or minus gaps, and aneugenic effects (hyperdiploidy or polyploidy). In general, the effects were small, but it was observed that benomyl and MBC significantly induced micronuclei as well as aneugenic effects, hyperdiploidy (no metaphases with more than one or two extra chromosomes, 2n + 1 or 2n + 2, were observed) and polyploidy (4n). The induction of chromosome gaps and breaks was less evident. Methyl thiophanate significantly induced micronuclei, but it was less effective than benomyl and MBC. Our results showed that micronuclei are a good indicator of aneugenic effects in mouse bone marrow cells. A curvilinear trend test has been devised to fit the curves originating from the time-dependent responses.
Subject(s)
Benzimidazoles/toxicity , Bone Marrow/drug effects , Carbamates , Chromosome Aberrations , Mutagens/toxicity , Analysis of Variance , Aneuploidy , Animals , Benomyl/toxicity , Bone Marrow Cells , Chi-Square Distribution , Male , Mice , Micronucleus Tests , Regression Analysis , Thiophanate/toxicityABSTRACT
Cyclophosphamide (CP)-induced micronuclei were evaluated in females of two strains of mice (C57BL and CD1), in F1 hybrid females and in fetuses (day 13 of gestation) obtained from different crosses. F1 adult hybrids from a cross between the strain with a high level of induced micronuclei (C57BL) and the strain with a low response (CD1) exhibited micronuclei values closer to the latter. CD1/CD1 fetuses showed a higher susceptibility than C57BL/C57BL ones. Heterozygous fetuses from reciprocal crosses, whatever the maternal genotype, showed the same sensitivity, which is very close to that of C57BL/C57BL fetuses. Phenobarbital (PB) pre-treatment modified the mutagenic response to CP depending on the genotype of the treated animal. These results demonstrate that the response to a pro-mutagen requiring metabolic activation depends to a large extent on the genetic background of the target animals, and that mother-fetus interactions in transplacental mutagenesis seem to depend more on the fetal than on the maternal genotype.
Subject(s)
Cyclophosphamide/toxicity , Maternal-Fetal Exchange , Mutagens , Mutation , Animals , Cell Nucleus/drug effects , Cell Nucleus/ultrastructure , Crosses, Genetic , Female , Fetus , Liver/drug effects , Liver/embryology , Liver/pathology , Male , Mice , Mice, Inbred C57BL , Mice, Inbred Strains , PregnancySubject(s)
Benzene/toxicity , Erythrocytes/ultrastructure , Animals , Cell Nucleus/drug effects , Cell Nucleus/ultrastructure , Female , Male , Mice , SplenectomySubject(s)
Blood Group Antigens , Isoantibodies , Twins, Monozygotic , Twins , ABO Blood-Group System , Female , Humans , Isoantibodies/analysis , Pregnancy , Rh-Hr Blood-Group SystemSubject(s)
Blood Proteins/genetics , Twins, Monozygotic , Twins , Adult , Aged , Child , Child, Preschool , Densitometry , Electrophoresis, Polyacrylamide Gel , Female , Humans , Middle Aged , PregnancyABSTRACT
The distribution of A1A2BO, MN, and Rh-Hr blood groups, of salivary ABH substances, and of natural antibodies, was assessed in a sample of 47 MZ twin pairs. The resulting distribution provides indications as to the level of genetic control over the quantitative expression of these traits.
