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R Kofler

Publications and source records attributed to R Kofler.

At least 91 records · Page 5Linked to original sources
PubMed1989

[Two-dimensional echotomography in the prevention of congenital hip dysplasia].

Examination of the infant hip with real time ultrasonography is spreading and affirming in these last years. It allows accurate and reliable investigation of the anatomic structures which are not visualized on a radiograph, so that it appears of great interest in the early screening of congenital dislocation of the hip (CDH). In this paper, the authors examine and discuss some particular features of the sonograms which are usually employed for the investigation of neonatal hips, attempting to dissolve some doubts and perplexities which commonly come out in the first approach to a new diagnostic image technique. The systematic examination of infant hips with real time ultrasonography promises a decisive improvement in the problem of the early diagnosis of CDH.

Hip Dislocation, Congenital↗
PubMed1988

[Molecular genetic analysis of autoantibody production in systemic lupus erythematosus].

This review summarizes studies from our and other laboratories attempting to define the molecular and clonotypic origin of autoantibodies that typify systemic autoimmune diseases such as lupus and rheumatoid arthritis. Comparative restriction fragment length polymorphism (RFLP) studies investigating the immunoglobulin (Ig) germline gene organization in lupus-prone strains of mice suggested that the disease can develop in different Ig heavy (H) and light (L) chain haplotypes, and that the Ig germline genes in lupus mice are probably normal. Analysis of the Ig gene segments expressed in monoclonal autoantibodies from autoimmune mice revealed that similar, and in some instances even identical, gene segments are expressed in autoantibodies and in antibodies to exogenous antigens, and that anti-self and anti-non-self responses are encoded by the same, or at least an overlapping germline gene repertoire. A large variety of Ig variable (V), diversity (D), and joining (J) gene segments can encode autoantibodies with different specificities, and both germline genes and somatically-mutated genes can be expressed in such antibodies.

Animals↗
PubMed1988

A new murine Ig VH gene family.

A novel murine VH gene family, termed VH10, has been found and characterized. Based on RFLP analysis, this family exhibits extensive polymorphism among inbred strains of mice and encompasses two to five members, depending on the Igh haplotype. Analyses of recombinant inbred strains suggest a map position of this family 5' to the 7183 and Q52 VH gene families. A VH10 gene has been found to encode anti-DNA autoantibodies from lupus mice; another one may be a pseudogene.

Amino Acid Sequence↗
PubMed1988

Immunoglobulin kappa light chain variable region gene complex organization and immunoglobulin genes encoding anti-DNA autoantibodies in lupus mice.

We have investigated the genetic origin of autoantibody production in several strains of mice that spontaneously develop a systemic lupus erythematosus-like disease. Restriction fragment length polymorphism analyses of gene loci encoding kappa light chain variable regions (Igk-V) demonstrated, as shown previously for the Ig heavy chain locus, that autoantibody production and disease occur in different Igk-V haplotypes. Moreover, autoimmune mice with known genetic derivation inherited their Igk-V loci essentially unaltered from their nonautoimmune ancestors. New Zealand black lupus mice, with unknown genetic derivation, had a possibly recombinant Igk-V haplotype, composed of V kappa loci that were primarily indistinguishable from those of nonautoimmune strains from either of the two potential donor haplotypes. The heavy and light chain gene segments (variable, diversity, joining) encoding anti-DNA antibodies were diverse and often closely related, or even identical, to those found in antibodies to foreign antigens in normal mice. Only 1 of 11 sequenced variable region genes could not be assigned to existing variable region gene families; however, corresponding germline genes were present in the genome of normal mice as well. These data argue against abnormalities in the genes and mechanisms generating antibody diversity in lupus mice and suggest a remarkable genetic and structural diversity in the generation of anti-DNA binding sites.

Amino Acid Sequence↗
PubMed1987

Specificity and molecular characteristics of monoclonal IgM rheumatoid factors from arthritic and non-arthritic mice.

Two-hundred twenty-four hybridomas secreting monoclonal IgM rheumatoid factor (hIgMRF) derived from MRL-lpr/lpr, MRL-+/+ and C57BL/6-lpr/lpr autoimmune mice were analyzed with regard to IgG subclass and domain specificity, and some for VH gene expression patterns. Among these mice, only MRL-lpr/lpr develop arthritis. Clonotypes specific for each of the four mouse IgG subclasses and clonotypes reacting with more than one IgG subclass were identified. Although each panel contained several clonotypes, the predominant one differed in each strain (MRL-lpr/lpr, anti-IgG2a; MRL-+/+, combined anti-IgG2a and 2b; C57BL/6-lpr/lpr, anti-IgG1 or combined anti-IgG1, 2a, and 3). The IgG domains recognized by these monoclonals were defined with mutant Ig carrying IgG1 heavy chains that lacked either the CH1 or CH3 domains, variant Ig carrying hybrid IgG2b-2a heavy chains, and IgG fragments. Inhibition of hIgMRF binding to IgG substrates by protein A was also assessed. Most determinants were assigned to the CH3 domain, but determinants in the hinge region, CH2 domain, and in some instances, even in the Fab portion, could also be identified. Hybridization of cytoplasmic RNA from 35 classes of diverse IgG subclass specificity with VH gene probes representing seven of the approximately 10 VH families (7183, S107, Q52, J558, J606, 36-60, X24) indicated that approximately 90% of these clones expressed VH genes belonging to the large J558 gene family. The results indicate that murine IgMRF are extremely heterogeneous in IgG subclass and domain specificities; the genetic background influences RF specificity characteristics that may relate to pathogenicity; and considering the complexity of the J558 VH gene family and reported RF heavy chain assignments to additional VH gene families, it appears that VH genes encoding RF are diverse.

Animals↗
PubMed1987

Molecular analysis of the murine lupus-associated anti-self response: involvement of a large number of heavy and light chain variable region genes.

The mRNA encoding heavy and light chains of a hybridoma-derived monoclonal IgM, kappa anti-immunoglobulin (rheumatoid factor) and an IgG3, kappa anti-histone autoantibody from systemic lupus erythematosus and arthritis-prone MRL/Mp-lpr/lpr mice have been molecularly cloned, and the nucleotide sequences corresponding to their variable regions have been determined. To investigate whether autoantibodies with specificities frequently observed in lupus disease might share common structural components, the sequences obtained in this study have been compared with those of a monoclonal MRL/Mp-lpr/lpr IgM, kappa anti-DNA autoantibody previously analyzed in our laboratory (J. Exp. Med. 1985. 161: 805). The 3 immunoglobulins employed different heavy chain variable region (VH) genes belonging to the large J588 VH gene family, kappa light chain variable region (V kappa) genes from 3 different V kappa groups, and different diversity and joining segments. Our findings suggest that murine lupus-associated autoantibodies of different specificities do not have genetic components in common to signal their self-reactive nature and are encoded by a large number of immunoglobulin gene elements.

Animals↗
PubMed1987

The genetic origin of murine lupus-associated autoantibodies.

Systemic lupus erythematosus and rheumatoid arthritis in human and murine systems are characterized by circulating autoantibodies and immune complex deposition in various organs causing tissue damage and disease. To define the molecular and clonotypic origin of these anti-self responses, and to determine whether abnormalities in Ig genes or somatic mechanisms generating autoantibody diversity may contribute to lupus etiology, we performed molecular analyses of the Ig germline gene organization and the Ig gene segments expressed in monoclonal autoantibodies from autoimmune mice. Comparative restriction fragment length polymorphism analysis of a large number of Ig gene loci from autoimmune and normal mice indicated that (a) lupus can develop in different Ig heavy and kappa light chain variable region gene haplotypes, and (b) the Ig germline genes in lupus mice might be normal. To determine whether autoantibodies are encoded by unique Ig gene segments present in the normal germline repertoire, but not expressed in exogenous responses, we compared nucleic acid sequences encoding lupus autoantibodies and antibodies against foreign antigens. Similar, and in some instances even identical, gene segments were expressed in both types of antibodies, indicating that anti-self and anti-foreign responses use the same, or at least an overlapping, germline gene repertoire. A large variety of Ig variable, diversity, and joining gene segments encoded these autoantibodies with different specificities. Hence, the overall murine lupus-associated anti-self response may be essentially unrestricted. Furthermore, limited evidence has been obtained that both germline genes and somatically mutated genes encode autospecificity, making gross abnormalities in mechanisms for somatic mutation of Ig variable genes unlikely.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Monoclonal antibodies against human, bovine and rat prolactin: epitope mapping of human prolactin and development of a two-site immunoradiometric assay.

Nine mouse hybridoma cell lines producing monoclonal antibodies (MCA) against human prolactin (hPRL), 19 cell lines against bovine prolactin (bPRL) and one MCA against rat prolactin (rPRL) were established. The MCA were characterized by one- and two-site radioimmunoassays (RIA) as well as indirect immunofluorescence (IIF) and used for epitope mapping of hPRL and immunoradiometric assays (IRMA). Interspecies cross-reactivity studies by RIA revealed two groups of anti-hPRL MCA: seven which reacted only with hPRL and two additionally recognizing bPRL and ovine prolactin (oPRL). The anti-bPRL MCA, which were tested on pituitary sections by IIF could be divided into 17 MCA cross-reacting with the closely related oPRL, and two MCA which showed additional cross-reactions with equine prolactin. The anti-rPRL antibody reacted exclusively with rPRL in direct binding RIA studies. No intraspecies cross-reactions with the closely related protein hormones placental lactogen and GH were detected. To elucidate the antigenic surface of hPRL all MCA directed against hPRL were then used for two-site epitope mapping studies in which pairs of MCA were assessed for simultaneous reaction with the same antigen. The native hormone was incubated with the first, solid-phase bound, so called 'capture MCA', and this complex treated with a second, 125I-labelled 'detection MCA'. Based on the results of these combinations, at least three sterically non-overlapping and (taking RIA cross-reaction studies into consideration) two additional epitopes could be defined.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Evidence for a new murine immunoglobulin heavy chain variable region gene family.

In the course of a previous study addressing autoantibody generation in murine models for generalized autoimmune disorders, we observed a nonfunctional immunoglobulin heavy chain transcript in a B cell hybridoma from lupus-prone MRL-Mp-lpr/lpr mice. This transcript, the cDNA sequence of which is presented here, is of general interest for murine immunoglobulin genetics as it cannot be ascribed to any known heavy chain variable region gene (Vh) family by nucleic acid sequence homology criteria and, hence, may represent a new Vh gene family. The sequence showed about equal nucleotide similarity (70-73%) to 3 other Vh gene families (S107, J606, 7183) and less than 65% similarity to members of the remaining 6 Vh gene families. Nucleic acid sequence comparisons with unpublished immunoglobulin sequences uncovered a highly homologous (greater than 95%) functional Vh transcript indicating that the suggested Vh gene family also encodes expressed antibody molecules.

Animals↗
PubMed1987

Genomic organization and expression of B and T cell antigen receptor genes in murine lupus.

Studies with genomic DNAs of lupus mice and monoclonal autoantibodies suggest that autoantibody expression does not result from defects in immunoglobulin germline genes nor in mechanisms generating antibody repertoires. Genomic and expression abnormalities of T cell antigen receptor genes have been identified in lupus mice, but their possible contribution to disease manifestations remains to be established.

Animals↗
PubMed1986

Delineation of a defect in T cell receptor beta genes of NZW mice predisposed to autoimmunity.

In an attempt to determine whether genes involved in T cell antigen recognition are structurally abnormal and thereby promote murine systemic lupus, we analyzed the structural integrity of the D, J, and C region elements of the T cell receptor alpha and beta chain genes in all major lupus strains and several normal strains. Within the limits of restriction fragment length polymorphism analysis, all strains had an identical genomic organization, except the NZW mice, in which a deletion of the C beta 1-D beta 2-J beta 2 elements was found. Sequence analysis of NZW genomic elements containing this deletion placed its probable origin within the first exon of C beta 1, and extending to a complementary region within the first exon of C beta 2. The significance of this abnormality in the pathogenesis of systemic autoimmune disease remains to be determined.

Animals↗
PubMed1985

Ig heavy chain variable region gene complex of lupus mice exhibits normal restriction fragment length polymorphism.

B cell hyperactivity, hypergammaglobulinemia, and autoantibody expression, the hallmarks of systemic lupus erythematosus, might be associated with structural abnormalities within the Ig heavy chain variable region (Igh-V) gene complex. The Igh-V loci from several lupus-prone mouse strains, their ancestors, and other nonautoimmune mice were therefore analyzed by restriction fragment length polymorphisms with DNA probes corresponding to seven VH gene families. These seven families comprise the majority of the known polymorphic murine VH gene repertoire, including some involved in autoantibody generation. Our study showed that the Igh-V loci from lupus and haplotype-matched nonlupus mice resulted in essentially identical restriction fragment patterns, a finding which suggests that the Igh-V gene complex does not carry a primary defect responsible for autoimmune disease.

Animals↗
PubMed1985

Genetic elements used for a murine lupus anti-DNA autoantibody are closely related to those for antibodies to exogenous antigens.

The mRNAs encoding heavy and light chains of a hybridoma-derived monoclonal IgM kappa anti-DNA autoantibody from lupus-prone MRL/Mp-lpr/lpr mice (Ighj) have been transcribed into cDNA copies and molecularly cloned, and their complete nucleotide sequences have been determined. The mRNA for the heavy chain variable region, including leader peptide and 5' untranslated region, is transcribed from a heavy chain variable region (VH) gene closely related (and possibly allelic) to VH genes of the C57BL/6 (Ighb) nitrophenyl antibody family. The deduced amino acid sequence corresponding to the light chain variable region of this autoantibody shows extensive similarities with non-autoantibody molecules of the V kappa 1 group, suggesting a common variable gene origin. The joining segments, constant regions, and 3' untranslated regions of both the heavy and light chain mRNAs are nearly identical to corresponding sequences of non-autoantibodies from normal mice. Our findings suggest that this anti-DNA autoantibody originated from the same germline repertoire as antibodies to exogenous antigens.

Animals↗
PubMed1984

Development of an enzyme-linked immunosorbent assay for the detection of autoantibodies against thyroglobulin in chickens.

This paper describes the development of an enzyme immunoassay (EIA) for the detection of autoantibodies against thyroglobulin in an avian system. In this system EIA offers an efficient and alternative approach to already established methods such as double diffusion in gel, passive haemagglutination, indirect immunofluorescence and radioimmunoassay. The optimization of the different incubation steps is described and the expression of results of observed antibody activity is discussed.

Animals↗