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Biomedical subjects

C R Bartram

Publications and source records attributed to C R Bartram.

At least 163 records · Page 9Linked to original sources
PubMed1989

Detection of minimal residual disease in acute lymphoblastic leukemia by in vitro amplification of rearranged T-cell receptor delta chain sequences.

Human T-cell receptor (TCR) delta-chain diversity mainly originates from high junctional variability, since only a limited number of germline elements is available. This extraordinary diversity at the V.J junction, due to the use of two D delta elements and extensive incorporation of N nucleotides, constitutes a specific clonal marker for cell populations exhibiting rearranged TCR delta genes. To this end we amplified in vitro by polymerase chain reaction (PCR) the TCR delta junctional region of five acute lymphoblastic leukemias (ALL), isolated respective DNA fragments, and used them directly as clonospecific probes. The combination of PCR technology and hybridization to clonospecific probes permitted the detection of leukemia DNA at dilution of 1:100,000 in all five cases. Moreover, we were able to investigate one of the ALL patients 11 months after achieving continuous complete remission. Conventional Southern blot analysis failed to detect rearranged TCR genes at this stage. However, residual leukemic cells could readily be detected by PCR technique. We conclude that the strategy proposed here is a very sensitive tool to detect minimal residual disease in a significant proportion of human lymphoid neoplasias.

Base Sequence↗
PubMed1989

Phenotypic and genotypic heterogeneity in infant acute leukemia. I. Acute lymphoblastic leukemia.

We have studied the immunophenotypic and genotypic features in 35 infants aged less than 1 year with acute lymphoblastic leukemia (ALL) or acute undifferentiated leukemia (AUL). A CD10 (common ALL antigen)-negative, CD19-positive pre-pre-B ALL phenotype was observed in 24 infants. Seventeen of them had blast cells coexpressing myeloid-associated markers such as CD15A (VIM-D5, MZ17) and/or VIM-2, but neither myeloperoxidase nor platelet peroxidase was detected in five of these cases analyzed by electron microscopy. Five patients showed a typical common ALL, five a pre-B ALL phenotype, and one infant was unclassifiable by surface-marker and morphologic analysis. Cytogenetic data, available in 21 of these patients, revealed chromosomal abnormalities involving 11q23 in 10 infants with a CD10-negative pre-pre-B ALL. Immunoglobulin (Ig) and T cell receptor (TCR) gamma, beta and delta gene analysis of 31 infants showed Ig heavy-chain gene rearrangement in all but one patient with evidence for clonal evolution in six and kappa-light-chain rearrangement in three infants. TCR beta-chain and TCR gamma-chain rearrangement occurred in six and five patients respectively, while TCR delta-chain rearrangement was identified in 15 patients. Our data indicate that ALL in infancy may present with heterogeneous immunophenotypic and genotypic features. The high frequency of coexpression of B-lineage and myeloid surface markers as well as of chromosomal rearrangement involving 11q23 suggests that the clonogenic cell of infant ALL may relate to a multipotent progenitor cell in most cases.

Antibodies, Monoclonal↗
PubMed1989

Phenotypic and genotypic heterogeneity in infant acute leukemia. II. Acute nonlymphoblastic leukemia.

We have studied the immunophenotypic and genotypic characteristic of acute nonlymphoblastic leukemias (ANLL) in infants aged less than one year. Sixty-four percent of cases (16/25) showed a myeloid or myelomonocytic differentiation pattern and 10 of these were classified as FAB M5 (7 M5a, 3 M5b). Only seven of the latter cases expressed the CD14 antigen. Acute megakaryocytic leukemia with a high number of glycoprotein IIb/IIIa or IIIa positive blasts were identified in five patients. Erythroleukemia with a high percentage of rather mature glycophorin A positive erythroblasts were diagnosed in two infants. Cytogenetic studies were successfully performed in all 20 cases investigated. Abnormalities involving chromosome 11 were present in 10 of 17 patients with an abnormal karyotype including five cases with a t(9;11)(p21;q23). Immunoglobulin (Ig) and T cell receptor (TCR) gene analyses were performed in 20 patients. A rearrangement of Ig heavy chain sequences was detected in five cases (20%), one of whom exhibited multiple rearranged fragments. Three of these patients showed additional TCR delta-chain gene rearrangements, while Ig kappa, TCR beta- as well as TCR gamma-chain genes showed a germline configuration in all cases analyzed. Our study confirms the high incidence of myelomonocytic and monoblastic subtypes in infants with ANLL, which are particularly closely associated with chromosome 11 abnormalities. However, we also observed an unexpected high frequency of megakaryoblastic leukemias as well as erythroleukemias. As previously reported for ALL in infants, ANLL of infancy shows a similar heterogeneity regarding phenotypic and genotypic features.

Antigens, Differentiation↗
PubMed1988

Immunoglobulin and T-cell receptor gene rearrangements in Hodgkin's disease.

We have examined tumor tissue DNA obtained from 32 cases of Hodgkin's disease of the following subtypes: lymphocyte predominance, six; nodular sclerosing, eight; mixed cellularity, 14; lymphocyte depleted, 4; using immunoglobulin and T-cell receptor beta and gamma gene probes. Immunoglobulin heavy chain rearrangements were detected in five patients; in three of them only a minor clonal cell population was visible. T-cell receptor gene rearrangement was not observed in any patient examined. Three patients exhibiting minor clonal immunoglobulin rearrangements showed polyclonal T-cells in the same sample. There was no correlation between the presence and intensity of the rearranged bands and the number of Reed-Sternberg cells. Our data do not confirm recent reports of a frequent occurrence of immunoglobulin or T-cell receptor gene rearrangements in Hodgkin's disease and suggest no possible relation between Reed-Sternberg cells and B- or T-lymphocytes, respectively.

DNA, Neoplasm↗
PubMed1988

Point mutation of the ras protooncogenes and chromosome aberrations in acute nonlymphocytic leukemia and preleukemia related to therapy with alkylating agents.

Nine cases of overt acute nonlymphocytic leukemia and four cases of preleukemia or a myelodysplastic syndrome, all related to intensive treatment with alkylating agents, were studied cytogenetically and investigated using a rapid and sensitive dot blot screening procedure for point mutations in the Ha-ras, Ki-ras, and N-ras protooncogenes within codons 12, 13, and 61. The technique involves a selective amplification of genomic DNA sequences containing the codon sequence of interest, in combination with oligonucleotide hybridization. Examining fractionated mononuclear cells from bone marrow or peripheral blood, an N-ras mutation at position 13 was observed in one patient with overt leukemia, resulting in a base change from GGT to TGT thus converting glycine to cysteine. The other cases exhibited no ras gene mutations. It is surprising that c-ras mutations are only occasionally observed in overt acute nonlymphocytic leukemia related to treatment with alkylating agents, as such abnormalities have often been observed in acute nonlymphocytic leukemia de novo, and as many alkylating agents are known to produce DNA adducts leading to point mutations and substitution of single amino acids. The fact that deletions of varying parts of the long arms of chromosomes 5 and 7 are observed in most cases of therapy-related acute nonlymphocytic leukemia and preleukemia, as confirmed by our own series of 71 patients, suggests that loss of heterozygosity for specific alleles on the two chromosomes, rather than activation of a protooncogene, could be an important step in leukemogenesis.

Acute Disease↗
PubMed1988

Clonal variation in childhood acute lymphoblastic leukaemia at early and late relapse detected by analyses of phenotype and genotype.

To increase our knowledge of the clonal relationship of leukaemia relapse, the genotypes and phenotypes of ten children with acute lymphoblastic leukaemia (ALL) were examined at initial diagnosis and relapse. Seven patients were phenotyped as common ALL, two as mixed, and one as T-cell ALL (T-ALL). Comparative analyses of immunoglobulin (Ig) heavy and light chain as well as T-cell receptor beta-chain (T beta) sequences revealed clonal variations, i.e. appearance of a novel or an evoluted leukaemic cell clone in five patients coinciding with the loss of common acute lymphoblastic leukaemic antigen (CALLA) in four cases, irrespective of early or late relapse. Conversion of early B- to T-ALL or lymphoblastic to non-lymphoblastic leukaemia was not noted in any of the patients examined. Our results suggest that clonal variation is a frequent event in childhood ALL.

Antigens, Differentiation↗
PubMed1988

Incidence of ras gene mutations in neuroblastoma.

Using a rapid dot-blot screening procedure based on DNA amplification and hybridization to synthetic oligonucleotide probes, we investigated 18 neuroblastomas in various clinical stages for the presence of ras mutations. In none of the samples was a mutation in the relevant codons 12, 13 or 61 of Ha-ras, Ki-ras or N-ras found. These data virtually exclude the participation of mutated ras genes in the genesis of neuroblastoma.

DNA Mutational Analysis↗
PubMed1988

Rapid and non-radioactive prenatal diagnosis of beta thalassaemia and sickle cell disease: application of the polymerase chain reaction (PCR).

The standard method for the prenatal diagnosis of the haemoglobinopathies is by restriction enzyme mapping of chorionic villus DNA using Southern blotting and radioactively labelled gene probes. An improvement of the procedure which involves the selective amplification of DNA fragments by the polymerase chain reaction allows one to visualize restriction fragments directly without the use of radioactivity and within 2 d after obtaining the sample. We report here the prenatal diagnosis of two pregnancies at risk for homozygous beta thalassaemia and homozygous sickle cell disease using this novel approach.

Anemia, Sickle Cell↗
PubMed1988

Activation of the mas oncogene during transfection of monoblastic cell line DNA.

Using the tumorigenicity assay, we observed an activation of the mas oncogene during transfection of human acute myelocytic leukemia (CTV-2) DNA. Respective transfectants contained amplified mas sequences characterized by rearrangements in 5' and 3' noncoding regions that were transcribed into a 3.3 kb mas RNA species. Our data represent the second report on activation of the mas gene.

Animals↗
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↗
PubMed1988

Ambiguous phenotypes and genotypes in 16 children with acute leukemia as characterized by multiparameter analysis.

Ambiguous phenotypes and genotypes were observed in 16 children with acute leukemia. Surface marker, cytogenetic, molecular genetic, and DNA flow cytometric analyses as well as standard morphologic and cytochemical studies were used to divide the patients into three groups. The first group comprised five children with acute leukemia whose blast cells were morphologically lymphoid, while immunophenotyping disclosed simultaneous expression of early pre-B cell and myeloid features. Molecular genetic studies showed evidence of heavy-chain immunoglobulin (Ig) gene rearrangements in all patients. Cytogenetic data, available in three of these children, revealed t(4;11). In five of the 16 patients, morphologic and surface marker analyses indicated the coexistence of two separate cell populations, one with myeloid and the other with early pre-B cell features. Further evidence of B cell commitment in these patients was provided by demonstration of Ig heavy-chain gene rearrangements in all five patients. Surprisingly, one of the five patients showed oligoclonal Ig heavy-chain as well as monoclonal gene rearrangement for the beta chain of the T cell receptor (beta-TCR). The last group consisted of four cases with otherwise typical acute lymphoblastic leukemia (ALL), early pre-B cell phenotype, and coexpression of myeloid or T cell-associated antigens, and two children with unequivocal acute myeloid leukemia (AML) and coexpression of T cell antigens. Gene rearrangement of Ig heavy-chain could be demonstrated in five of six patients, additional Ig light-chain gene rearrangement in two children with ALL, and bigenotypic features (Ig heavy-chain and beta-TCR gene rearrangement) in one patient. In none of the 16 patients did flow cytometry disclose clonal abnormalities of leukemic cell DNA content. Based on these findings, we suggest that malignant transformation in the first and second group of patients took place at a stage ontogenetically close to the pluripotent stem cell, whereas ambiguous phenotypes in the third group resulted from aberrant gene expression or insufficient reagent specificity.

Acute Disease↗
PubMed1988

Evidence for pluripotent stem cell origin of idiopathic myelofibrosis: clonal analysis of a case characterized by a N-ras gene mutation.

Three cases of idiopathic myelofibrosis were screened for the presence of mutations at codon 12, 13, or 61 of the ras gene family by a rapid method based on polymerase chain reaction and hybridization to mutation-specific oligonucleotides. PB cells of one patient showed a point mutation at codon 12 of the N-ras oncogene. This molecular genetic hallmark was used to investigate the clonal relationship of different cell lineages by cell separation analysis. Presence of the N-ras 12 mutation in granulocytes, monocytes, B cells, and T lymphocytes, as well as erythroblasts, indicates that idiopathic myelofibrosis originates from a pluripotent stem cell, at least in this patient.

Clone Cells↗
PubMed1988

Mutations in ras genes in myelocytic leukemias and myelodysplastic syndromes.

Acute myelocytic leukemias (AML) are characterized by a remarkably high incidence (approximately 30%) of point mutations affecting codons 12, 13, or 61 within ras genes. A predominant involvement of N-ras sequences has been established. Neither Philadelphia chromosome-positive chronic myelocytic leukemia nor other chronic myeloproliferative disorders show a similar frequency. However, a proportion of myelodysplastic syndromes, namely, the chronic myelomonocytic subtype (CMML) also show this molecular feature. The following is a brief discussion of the possible biologic and clinical implications of these observations.

Genes, ras↗
PubMed1988

T cell receptor alpha mRNA transcription in T-lymphoblastic transformation of chronic myelocytic leukemia.

Analysis at the DNA and RNA level revealed a mature genetic marker profile in a case of T type blast crisis of chronic myelocytic leukemia. T cell receptor beta chain gene rearrangement as well as T cell receptor alpha mRNA transcription was demonstrated in blasts of the malignant clone. Corresponding findings were obtained from immunological phenotyping. Blasts were found to be CD7+, CD1+, CD3+, CD4+, CD8+, and TdT- and classified as common/mature thymocytes. The presence of the breakpoint cluster region gene on chromosome 22 excluded the possibility of a second neoplastic process.

Adult↗