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T Boehm

Publications and source records attributed to T Boehm.

117 records · Page 7Linked to original sources
PubMed1988

Complex rearrangements within the human J delta-C delta/J alpha-C alpha locus and aberrant recombination between J alpha segments.

We have examined DNA rearrangements within a 120 kb cloned region of the human T cell receptor J delta-C delta/J alpha-C alpha locus. Three types of pattern emerge from an analysis of T cell lines and clones. Firstly, cells with two rearrangements within J delta-C delta; secondly, cells with one rearrangement within J delta-C delta and one or more J alpha rearrangements, and finally, cells with rearrangements within J alpha and consequential deletion of the delta locus. Further analysis by cloning of rearrangements within the J alpha locus show that, in addition to V alpha-J alpha joins, J alpha-J alpha aberrant recombinations occur and rearrangement data indicate that such events are frequent. A model is presented to account for such recombinations.

Amino Acid Sequence↗
PubMed1988

A cluster of chromosome 11p13 translocations found via distinct D-D and D-D-J rearrangements of the human T cell receptor delta chain gene.

Human T cell tumours have few consistently occurring translocations which provide markers for this disease. The translocation t(11;14)(p13;q11), however, seems to be an exception, since it has been repeatedly observed in T-ALL. We have analysed a number of T-ALL samples carrying the t(11;14) with a view to assessing the nature of the translocated sequences on chromosomes 11 and 14. Three of the tumours studied have breakpoints, at 14q11, within the T cell receptor delta chain locus, while a fourth appears to break in the J alpha region. The TCR delta sequences involved in the translocation junctions are made from D delta-D delta-J delta joins or from D delta-D delta joins, allowing us to define distinct human D delta and J delta segments. These results allow us to make a comparison between the human and mouse TCR delta loci, both as regards sequence and rearrangement hierarchies. The disparate translocation breakpoints at chromosome 14q11 contrast with the marked clustering of breaks at chromosome 11p13; in all four cases, the breakpoint occurs within a region of less than 0.8 kb of chromosome 11. The analysis of junctional sequences at the 11p13 breakpoint cluster region only shows a consensus heptamer-like sequence in one out of four tumours analysed. Therefore, recombinase-mediated sequence specific recognition is not the only cause of chromosomal translocation.

Animals↗
PubMed1988

The T-ALL specific t(11;14)(p13;q11) translocation breakpoint cluster region is located near to the Wilms' tumour predisposition locus.

A breakpoint cluster region (T-ALLbcr) has been previously described on 11p13 for T-ALL carrying t(11;14)(p13;q11). One further T-ALL breakpoint is described bringing to 5 out of 6 such translocations which are found to break within a maximum of 6.7 kb on chromosome 11p13. Studies of somatic cell hybrids derived from t(11;14)(p13;q11) T-ALL placed the T-ALLbcr between the genes for catalase (CAT) and the beta-subunit of follicle stimulating hormone (FSHB). This suggested a link between the T-ALLbcr and the Wilms' tumour predisposition locus (WT) since constitutional 11p13 deletions predispose to Wilms' tumour. Utilising somatic cell hybrids from patients with Wilms' tumours and aniridia, we show that while the T-ALLbcr maps distal to the catalase gene at 11p13, it maps outside the shortest region of overlap of a series of 11p13 deletions associated with Wilms'-Aniridia. The data suggest the order of genes at 11p13 to be: centromere-CAT-T-ALLbcr-WT-aniridia-FSHB-telomere. Therefore, the T-ALLbcr must lie very close to but may be distinct from the Wilms' predisposition locus at 11p13.

Aniridia↗
PubMed1988

Establishment of two Epstein-Barr virus negative Burkitt cell lines from a patient with AIDS and B-cell lymphoma.

To analyze the pathogenesis of B-cell lymphomas in patients with acquired immunodeficiency syndrome (AIDS), we studied two cell lines, Es I and Es III, established from one such lymphoma for the presence of sequences of the Epstein-Barr virus (EBV) and the human immunodeficiency virus [HIV; lymphadenopathy-associated virus (LAV/HTLV-III)] as well as for the presence of cytogenetic abnormalities and monoclonal rearrangements of immunoglobulin and T-cell receptor genes. Both cell lines expressed the same IgM, kappa phenotype as the original lymphoma. The karyotype of Es I was 46, XY, t(8;14), 2 p+, inv (6p), 17p-, and the cells of Es III had an additional i(7q). Immunoglobulin gene studies demonstrated the identical monoclonal rearrangements in both cell lines. Neither EBV nor HIV sequences were detectable in the malignant B cells at the genomic level, leading to the conclusion that mechanisms other than transformation by EBV or HIV may have contributed to the B-cell lymphoma in this patient and possibly also to the generally increased frequency in patients with AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1977

Severe persistent biphasic local (immediate and late) skin reactions to insulin.

A patient with adult-onset insulin-requirging diabetes mellitus had persistent severe local reactions to all available insulins of animal origin. Skin reactions were biphasic in nature with both immediate and late characteristics. An extensive immunologic investigation of this problem was undertaken, revealing evidence of reaginic antibody involvement in the reactions. Routine histologic studies suggested the possibility that Arthus-type mechanisms played a part, although this impression was not confirmed by immunofluorescent microscopy. A program of medical management provided some relief of symptoms.

Aspergillus fumigatus↗