Biomedical subjects
Publications and source records attributed to M Cramer.
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Antigen-binding receptors of T lymphocytes were analyzed in two different ways. First, the idiotypic properties of T helper cells are studied using anti-idiotypic antisera prepared against isolated antibodies specific for A-CHO. These anti-idiotypic antisera are defined by immunogenetic and immunochemical means with respect to their reactivity with heavy- or light-chain-associated idiotypic determinants. Second, antigen-binding receptors are isolated from enriched T-and B-lymphocyte preparations and compared with respect to their reactivity with antigen and with class- or allotype-specific anti-Ig antisera. The results provide an incomplete picture of the T-cell receptor which shares with antibodies the variable region of the heavy chain but probably no other variable or constant portion.
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In previous publications it was shown by avidity measurements, cross-reactivity patterns and genetic analyses, that the tetrapeptide T-T-G-G is the immuno-dominant epitope of the synthetic polypeptide (T, G)-A--L. In the present study this close immunological relationship between the random multichain copolymer (T, G)-A--L and the ordered analogue (T-T-G-G)-A--L is extended by two additional criteria. First, the immune response against (T-T-G-G)-A--L in H-2k nonresponder mouse strains can be reconstituted to high antibody levels by complexing this antigen to methylated bovine serum albumin, as was tested earlier for (T,G)-A--L. The antibodies elicited upon reconstitution in both antigenic systems are directed mainly against the same determinant, T-T-G-G. Second, isoelectric focusing analysis of specific antisera developed with radiolabeled antigen revealed restricted 7 S IgG antibody populations in high responder and reconstituted high and low responder mice. The spectra were found to be of similar complexity in the (T,G)-A--L and in the (T-T-G-G)-A--L system. From these data it was concluded that the repertoires of specific B cells to T-T-G-G are very similar in high and low responder strains, and the defect in the H-2k low responder systems should be located at the level of T-B cell cooperation.
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In response to community needs and pressures, increasing numbers of small crisis centers and hotline services have emerged. This emergence of services has been possible in part because of the mounting number of eager and interested volunteers. These services want and need training for the volunteers. This article examines the problem of evaluating the kind of information and the kind of training that hotline volunteers were given in a brief training program.
This study focused on some of the determinants of schematic interactional distance based on an analysis of social learning processes. It was hypothesized that closer interpersonal constructions would be associated with a more positive rather than negative self-concept, a greater rather than lesser degree of trust, and a covert positive rather than negative self-disclosure to a significant other. One hundred fifty-nine male and female undergraduate students were administered the Tennessee Self Concept Scale and Jourard's Self-Disclosure Questionnaire. Of these Ss, 82 were also given either positive or negative covert self-disclosure conditions. Interactional distances consisted of "Self" placements in relation to several key social target representations. The results supported the hypothesis regarding the relationship between self-concept and psychological distance, but only for females. There was also a tendency for more trusting females to produce closer distances than less trusting females. These results, as well as the obtained significant sex differences in distancing responses and in renditions of vertical displacements, were discussed within the context of culturally determined sex role differences.
Immune responsiveness to the streptococcal group polysaccharides at the clonal level can conveniently be monitored by analytical isoelectric focusing combined with autoradiography. The parameters investigated in this paper can be summarized as follows: [1] Within the first week after injection antistreptococcal p0lysaccharide responses are characterized by IgM antibodies, followed by subclass restriction in Balb/c mice to IgG2a antibodies. [2] The clonal pattern of specific IgG2a antibodies established in the second week after immunization does not change within the following 6 weeks. [3] Persistence of a specific response pattern established within a primary immunization course holds for Balb/c mice and rabbits for as long as 12 to 13 months. [4] Repeated immunization courses in mice and rabbits maintain established clonal antibody patterns in toto. Temporal variations of clonal expression are generally quantitative rather than qualitative. B-cell memory within this system is therefore stable and long-lived.
The immune response of nine inbred and one outbred strain of mice to the streptococcal group A polysaccharide was investigated with respect to magnitude and restriction. Analytical isoelectric focusing served as a tool to estimate the degree of restriction of Group A polysaccharide-specific antibodies. It proved feasible to distinguish low and intermediate from high responder strains, and to delineate strain-specificity of isoelectric focusing spectra of the immune sera. For example, immune sera of BALB/c mice, restricted high responders, and of C57BL/6 mice, heterogeneous low responders, had distinct focusing properties. Responsiveness was a dominant autosomal genetic trait in C57BL/6 x BALB/c F(1) hybrid mice, irrespective of the maternal and the paternal genotype; the immune sera of these mice had their own, rather uniform isoelectric focusing spectra whereby structural genes of the low responder strain were expressed to predominant levels in 81% of the hybrids. Responsiveness in C57BL/6 x BALB/c F(2) progeny segregated into 79% high and 21% low responders, and showed no genetic linkage to the following characteristics: hair color, sex, H-2 type, and Ig allotype of the heavy chain. The isoelectric focusing properties of these immune sera indicated segregation into patterns like BALB/c mice (40%), F(1) hybrids (48%), and C57BL/6 mice (12%). Since this segregation is independent of any of the above criteria in these F(2) mice a regulatory gene(s) is postulated that controls the clonal pattern of the immune response.
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Immunization of BALB/c mice with Group A streptococcal vaccines leads to the induction of high levels of monoclonal antibody populations. Subsequent immunization of these mice with Group A-variant streptococcal vaccines induces a significant level of monoclonal antibody of A-variant antigen specificity revealed by labeled group A-variant polysaccharide. During these course Av and Av' immunizations, the monoclonal Group A-specific antibodies were also restimulated to levels usually higher than the variant-specific antibodies. With two exceptions, these homogeneous antibody populations were not cross-reactive in vitro with the related antigen. Such cross-stimulation of monoclonal antibodies was interpreted as a function of particular membrane properties of the Ig receptor-bearing memory cells which, for restimulation, would only require the structurally closely related antigen which serves as a backbone to the original antigen, and not necessarily the exact fit of the homologous immunodominant group.
Immunization of rabbits from a closed colony with streptococcal Group A-variant vaccines identified about two-thirds of them as low and heterogeneous responders. One-third of the rabbits showed a restriction of the response independent from the magnitude. Selective breeding from one monoclonal high-responder male and two restricted high-responder female rabbits succeeded in segregation of high-responder progeny after two generations. Their antibody levels were on the average 2.5 times higher than those of the random group of rabbits and a small group of low-responder offspring. Immunization of 13 offspring originating from rabbits bred for restricted high response to the streptococcal Group C polysaccharide revealed that 11 progeny were restricted high responders and 2 progeny monoclonal high responders. This finding suggests that high responsiveness to the Groups A-variant and C polysaccharides is inherited as genetically linked traits. Selective breeding combinations between restricted and monoclonal high-responder rabbits by brother-sister matings succeeded in narrowing the isoelectric focusing spectra of Group A-variant-specific antibodies in the offspring. It furthermore revealed a preferential expression of monoclonal antibodies after three generations with a similar net charge as those identified first in the original monoclonal paternal parent. These data suggest that similar copies of structural genes for the variable regions are transmitted from the parent to the progeny.
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