Search PubMed⌕ Search

Biomedical subjects

J G Bodmer

Publications and source records attributed to J G Bodmer.

At least 37 records · Page 2Linked to original sources
PubMed1995

Defining the allelic variants of HLA-A30 in the Sardinian population using amplification refractory mutation system--polymerase chain reaction.

HLA-A30 is present in the Sardinian population at a frequency of 23%. We have designed a system using nested ARMS-PCR to determine the relative frequencies of the HLA-A*30 allelic variants (A*3001, A*3002, and A*3003) within this population. The use of a nested PCR approach, in which the first-round reaction provides HLA-A*30 specificity and template DNA for the subsequent nested reactions, is a powerful means of discriminating between alleles of very similar sequence. Using this method, we performed subtyping of 35 serologically defined HLA-A30 Sardinian individuals, and taking into account homozygotes, identified 38 A*30 alleles. Of these, 33 typed as A*3002, four typed as A*3001, and one sample did not conform to the patterns of reactivity of any of the published A*30 alleles. Haplotype information showed strong linkage disequilibrium between A*3002 and B18. This study underlines the potential of DNA-based methods for typing HLA class I in terms of adding further levels of definition to studies of population structure and also as a means of identifying new alleles.

Alleles↗
PubMed1995

Candidate regions for a testicular cancer susceptibility gene.

Epidemiological data suggest the presence of a susceptibility gene for testicular cancer in some families. Families with multiple cases of testicular cancer are rare and almost all those reported have only two affected members. We have performed a sib-pair analysis on 35 families in which there are either two or three affected brothers. These families have been typed for 220 autosomal microsatellite markers spaced 10-20 cM throughout the genome. Six regions which gave a LOD score of more than 1.0 on formal linkage analysis or a P value of 0.05 or less using a non-parametric approach are considered as candidate regions for a susceptibility gene. Of particular interest is one region on chromosome 4. Two neighbouring probes in this region both scored positively with LOD score of 2.60 on multipoint analysis. An International Testis Cancer Linkage Consortium has been formed to pool resources and will investigate these findings further with the world-wide collection of families.

Genetic Linkage↗
PubMed1995

Sequencing-based typing reveals new insight in HLA-DPA1 polymorphism.

An HLA-DPA1 sequencing-based typing (SBT) system has been developed to identify DPA1 alleles. Up to now eight DPA1 alleles have been defined. Six can be discriminated based upon exon 2 polymorphism. The three subtypes of DPA1*01: DPA1*0101, DPA1*0102 and DPA1*0103, have identical exon 2 sequences but show differences in exon 4. Exon 4 sequences were known for only the three DPA1*01 subtypes and for DPA1*0201. We now present additional sequence information for exon 4 and the unknown segments at the 3' end of exon 2. Additionally with the use of this sequencing technique it is also possible to identify previously unidentified polymorphism. We have studied the exon 2 and exon 4 polymorphism of DPA1 in 40 samples which include all known DPA1 alleles. A new allele, DPA1*01 new, was identified which differs by one nucleotide in exon 2 from DPA1*0103, resulting in an aspartic acid at codon 28. The DPA1*01 subtypes DPA1*0101 and DPA1*0102 could not be confirmed in samples which previously were used to define these subtypes, and consequently they do not exist. The exon 4 sequence of DPA1*0201 is corrected based on sequence data of DAUDI, the cell line in which DPA1*0202 was originally defined. The exon 4 regions of the remaining four alleles were resolved: the exon 4 regions of the alleles DPA1*02021 and DPA1*02022 were found to be identical to the--corrected--DPA1*0201 whereas the exon 4 region of DPA1*0301 differs by one nucleotide compared to DPA1*0103. The DPA1*0401 exon 4 region differs by one nucleotide compared to the corrected DPA1*0201.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1994

A clinical and epidemiological study of human leukocyte antigen-DPB alleles in Hodgkin's disease.

An international study to investigate the role of human leukocyte antigen (HLA)-DPB alleles in Hodgkin's disease was conducted with 17 participating centers in 12 countries. A total of 741 patients and 686 controls were typed using polymerase chain reaction amplification of HLA-DPB alleles and subsequent sequence specific oligonucleotide hybridization. The frequency of HLA-DPB1*0301 was found to be significantly increased in white patients, compared with ethnically matched controls. In this population group, the DPB1*0301 allele is associated with a relative risk of 1.95 (P < 0.01). There was also a significant reduction in the frequency of HLA-DPB1*0401 in patients from Japan and Taiwan (relative risk, 0.15; P < 0.01). Clinical analysis from data on 551 patients demonstrated a significantly inferior remission duration in patients with HLA-DPB1*0901, overall (P < 0.05), and in the Japanese and Taiwanese populations (P = 0.02), where this allele is most prevalent. This analysis suggests an epidemiological as well as a possible prognostic association between HLA-DPB alleles and Hodgkin's disease.

Alleles↗
PubMed1994

Proliferation of Reed-Sternberg cells and variants in Hodgkin's disease.

The proliferative activity and the origin of multinucleated Reed-Sternberg cells and mononuclear variants in Hodgkin's disease have been studied in the past using several techniques. The presence of both proliferating-cell nuclear antigen and the cell-proliferation-associated antigen Ki-67 have also been reported in Hodgkin's disease. P34cdc2 is the protein product of the cell-cycle-control cdc-2 gene. Using a monoclonal antibody against the protein p34, cases of three different histological subtypes of Hodgkin's disease have been studied along with normal tonsil and follicular lymphoma as controls. In all these cases of Hodgkin's disease, positive p34 staining was seen in the majority of Reed-Sternberg cells and mononuclear variants (> 80%), along with a proportion of small lymphocytes, mainly T cells. Staining was predominantly cytoplasmic and occasionally additional nuclear signals were apparent. In two cases, double immunostaining with the anti-p34 antibody and CM-1 for p53 demonstrated positive signals for both proteins within the same neoplastic cells. Although the presence of p34 in Reed-Sternberg or variant cells reflects mitosis and hence suggests proliferation, the possibility of endomitosis remains and may explain the multinucleated appearance of Reed-Sternberg cells.

CDC2 Protein Kinase↗