PubMed HealthSearch

Biomedical subjects

C Rittner

Publications and source records attributed to C Rittner.

At least 19 recordsLinked to original sources

[C6-polymorphism of the sixth component of complement: application to paternity cases (author's transl)].

The results of a study of the polymorphism of the sixth component of human complement by means of isoelectric focusing in polyacrylamide gels with subsequent C-dependent lysis in an agarose overlay containing C6 deficient rabbit serum are reported. The allele frequencies obtained (C6A = 0.613, C6B = 0.379, C6R = 0.008) are in good agreement with those previously published. The mode of inheritance in 47 families with 173 offspring as well as 26 mother-child combinations is in agreement with a formal genetical model: "C6A, C6B, C6A1 and C6B1 at an autosomal locus". The inclusion of this system into a blood group expertise in Germany can be recommended.

Adult

Polymorphism of the second component of human complement (C2). Observation of the rare phenotype (C2 2 (= C2 B) and data on the localization of the C2 locus in the HLA region.

The polymorphism of the second component of human complement was studied by means of isoelectric focusing in polyacrylamide gels with subsequent complement-dependent lysis of sensitized sheep erythrocytes in an agarose overlay containing C2-deficient or normal human serum. In a material of 289 unrelated individuals the following gene frequencies were observed: C21=0.965 and C22=0.035. The rare phenotype C2 2 (=C2 B) could be seen once in a child of a C2 1--2 heterozygous mother. The investigation of the C2/HLA relationship revealed a very close linkage: Among 62 informative meiotic divisions one recombination between HLA-B and C2 was found (i.e. 1.61%); in addition, C2(2) was significantly associated with HLA-B15 and -Cw3. In a family with an HLA-B/D(DR) crossover C2 segregated together with HLA-D(DR). This supports the assumption of a C2 structural locus outside HLA-B, probably near HLA-D(DR).

Alleles

Evidence for subtypic determinants in the HLA-DW3 cluster.

This study was undertaken to get more insight into the previously suggested heterogeneity of the HLA--DW3 cluster. Preliminary evidence of DW3 heterogeneity was derived from results of intrafamilial mixed lymphocyte culture tests (MLC) where cells of apparently homozygous offspring revealed unexpected stimulations of one of the parents' cells. Therefore, 15 different homozygous typing cells (HTCs) of DW3 specificity were tested against 43 HLA-DW3 heterozygous individuals. The response patterns of the 43 HLA-DW3 heterozygous cells toward 13 HTCs leads to the definition of at least three groups of DW3 stimulating cells. According to these patterns, four groups of responding cells could be classified. These results were confirmed by a MLC checkerboard experiment running all DW3-HTCs against each other. Discussing all possible explanations for these observations, the authors conclude that the existence of DW3 subtypes having some properties in common is the most likely interpretation of the results obtained. Family segregation studies will be needed to define the genotypic situation of the DW3 cluster.

Antibody Specificity

Evidence for a 'silent allele' GLO0 at the glyoxalase I locus.

In a three-generation family, the segregation of an apparent silent allele at the GLO I locus in association with the rare HLA haplotype 'AW30-CW4-BW35' was observed in four members. In two cases the assumption of homozygosity at the GLO locus would lead to mother-child exclusions. Phenotypically, the GLO activity in the GLO0 carriers is clearly diminished.

Alleles

[Distribution of the HL-A antigens in patients with pigeon breeder's lung].

HLA B8 was found in 29% of patients suffering from pigeon fancier's lung, as compared with a normal frequency of HLA B8 of 17%. In patients suffering from the acute form of the disease HLA B8 was found in 42%. HLA B13 and HLA BW17 could not be demonstrated in any patient with pigeon fancier's lung.

Adolescent

Pigeon breeders' lung lacking detectable antibodies.

Whereas fifteen pigeon fanciers suffering from extrinsic allergic alevolitis from avian dust had high titres of antibodies against pigeon antigens, antibodies were not demonstrable, even by immunofluorescence, in the serum of a symptomatic individual exposed to minimal amounts of avian dust. Following exposure to larger quantities of pigeon dust inhalation challenges, a low titre of antibodies appeared, but disappeared again after avoidance of the allergen. Cell-mediated immunity was elevated in the lymphocyte transformation test and also decreased after avoidance of allergen contact. Therefore, it seems likely that the antibody is not the only mediator of pigeon breeder's lung. Inhalation challenges and T cell-dependent immune reactivity may reveal more avian dust sensitive individuals suffering from fibrosis without the typical history of extrinsic allergic alevolitis and without detectable antibodies.

Allergens

Application of a computer program for the mapping of a gene locus to the disputed PGM3 localization on human chromosome 6.

The program GENEMAP, which performs the computations of a model for the mapping of a gene locus (Baur & Spitzer 1978), is applied to the localization of the phosphoglucomutase 3 with family data as published by Lamm et al. (1972), Rittner & Kalbheim (1975), Albert et al. (1977) and Kömpf et al. (1977). On the basis of Lamm's recombination fractions the combined odds were 13 : 1 in favor of an orientation of PGM3 to the HLA--B-side.

Chromosome Mapping

Three-point association of HLA-A,B,Bf haplotypes deduced in 200 parents of 100 families.

The association of HLA-A and -B antigens with Bf alleles was investigated in 200 parents from 100 unrelated families. There were significant associations between HLA-A3 and Bf-F, B7 and Bf-S, B8 and Bf-S, B12 and Bf-F, and BW 35 and Bf-F. Three-point HLA-A,B,Bf haplotype frequencies, linkage disequilibrium parameters, and chi-square values were determined both from the genotype and from the phenotype data. Although the HLA-B,Bf associations involve antigens that are also present in the highly associated A,B and B,D haplotypes of the Caucasian population, there was--with the possible exception of HLA-A3,B7,Bf-S--no significant three-point association for HLA-A,B,Bf.

Adult

Population data on two new HLA-D determinants, EI and RE.

Homozygous typing cells (HTC) for two new HLA-D determinants, EI and RE, defined by family studies, are described. The HLA-D typing experiments among more than 300 unrelated individuals showed phenotype frequencies of 0.045 for EI and 0.098 for RE. Since the tested population was also typed for its HLA-A and -B alleles, linkage disequilibrium parameters could be calculated: HLA-D type EI was statistically significantly associated with HLA-B13 and Bw17, HLA-D type RE with HLA-Bw40. These data support the working hypothesis that both EI and RE are new alleles of the HLA-D series.

Alleles

Genetic loci of components of the classical and alternate pathway of complement activation: a new dimension of the immunogenetic linkage group (HLA) on chromosome 6 in man.

In this review, a working hypothesis is put forward that functional cooperation of various types of cells and proteins in immune recognition, mediation and response is maintained by a common chromosomal region which evolved over millions of years from a common ancestor by gene duplication. In brief, the known functions of the H-2 complex are discussed (susceptibility and resistance to viral infection, immune response genes, T-B cell interaction as non-self recognition and response). The addition of loci of the classical and alternate pathway of complement activation to the HLA region (i.e., C2, C4 and the Bf system) is reviewed with respect to functional relationship to immune recognition and mediation mechanisms. As expected according to this hypothesis, genes for late-acting components (C3, C5, C7 and C8 in man, C5 in mice) have so far not proved to be linked to HLA.

Animals

Localization of the Bf locus within the HLA region. Report on an informative family and critical evaluation of available data on Bf mapping.

Since the estimation of recombination fractions is only an arbitrary means to map genetic loci on chromosomal regions, family studies of cases with informative cross-overs within the region in question are of decisive importance. This paper reports the study of a family with a HLA-B to HLA-D cross-over which is informative in the Bf system. The possible reasons for conflicting published data on Bf gene mapping are discussed.

Chromosome Mapping

Lack of linkage between gene(s) controlling the synthesis of the seventh component of complement and the HLA region on chromosome No. 6 in man.

The family of an individual was studied who lacks the seventh component of complement in his serum (C7 homozygous deficiency). Both parents are C7 heterozygous-deficient. In this investigation, the following parameters were determined: complement components in functional and immunochemical tests; HLA-A,B antigens, HLA-D (MLC) determinants; the Bf system; glyoxalase I and B cell antigens. No evidence for linkage between the immunogenetic linkage group on chromosome 6 and gene(s) controlling the synthesis of the seventh component of complement was obtained. This is in according with the assumption that only genes controlling components of the initiating rather than the membrane attack unit of complement are linked to the HLA region.

Child

[Program for the computation of plausibilities of paternity by means of serological findings. II. Demonstration of examples (author's transl)].

By demonstrating three actual cases of disputed paternity the validity of the computer program described in the first part of this paper is shown, namely: the information with respect to possible unrecognized exclusions pointing to chances of extended family studies; the standard deviation and distribution curve giving an actual survey of statistical parameters of a given case of disputed paternity.

Blood Group Antigens