Biomedical subjects

J A van den Berghe

Publications and source records attributed to J A van den Berghe.

7 recordsLinked to original sources

PubMed2000

Static cytometry identifies hyperdiploid childhood ALL.

Hyperdiploid acute lymphoblastic leukemia of childhood has long been identified with a good prognosis. Identification of this subgroup before treatment commences would enable the most appropriate regimen to be selected. Static cytometry permits an assessment of the DNA content of morphologically selected interphase cells. The blast cells from seven retrospective and seven prospective cases were studied and the ploidy levels compared with the bone marrow karyotype. Static cytometry rapidly identified the hyperdiploid karyotype and, as it was performed specifically on blast cells, it also identified the percentage of these blast cells that were hyperdiploid.

Aneuploidy↗

PubMed1989

Rapid sexing of human embryos by non-radioactive in situ hybridization: potential for preimplantation diagnosis of X-linked disorders.

Sixty spare human embryos at various stages of preimplantation development were prepared for cytogenetic analysis. Fluorescent staining of those with metaphases allowed scoring for the presence of a Y chromosome. In situ hybridization was then performed using a biotinylated Y-specific sequence, and the probe was detected by a standard streptavidin-linked alkaline phosphatase system. This enabled comparison of the chromosomal sex with that obtained after in situ hybridization in 28 embryos, and the sexing result obtained by the two methods was concordant in all cases. A further 21 embryos in which no metaphase chromosomes were obtained were sexed by biotinylated in situ hybridization only. Overall, 66 per cent of male interphase nuclei demonstrated a Y-specific hybridization signal. Results were obtained in under 24 h, which may permit the sexing of an embryo biopsied during cleavage and the transfer of sexed embryos at the blastocyst stage to the mother's uterus in the same cycle as oocytes are collected for in vitro fertilization.

Blastocyst↗

PubMed1989

Three infants having null acute lymphoblastic leukemia with chromosome rearrangements at 11q23: no involvement of a heritable fragile site in this band.

Three families are presented in which an infant with null acute lymphoblastic leukemia had a karyotype rearrangement involving a break at 11q23. Peripheral blood was obtained, where possible, from both parents and from the child during periods of remission. The blood was stimulated with phytohemagglutinin and cultured under conditions that enhance expression of heritable folate-sensitive fragile sites. In all individuals studied very low levels of fra(11)(q23.3) were observed. These levels were far below those recorded for expression of the heritable folate-sensitive site fra(11)(q23.3) but are comparable with expression of the common fragile site fra(11)(q23.3) under these conditions.

Chromosome Banding↗

PubMed1988

Regional chromosomal localisation of APOA2 to 1q21-1q23.

Using in situ hybridisation, we have mapped APOA2 to the 1q21-1q23 region of chromosome 1. DNA hybridisation to somatic cell hybrids made from cells carrying a balanced translocation between X and 1 confirms the localisation as proximal to 1q23. This was further confirmed by the presence of two polymorphic alleles in a cell line carrying a deletion of 1q25-1q32.

Animals↗

PubMed1987

Novel non-isotopic in situ hybridization technique detects small (1 Kb) unique sequences in routinely G-banded human chromosomes: fine mapping of N-myc and beta-NGF genes.

A novel in situ hybridization technique is described. This non-radioactive technique combines, for the first time, the high spacial resolution and rapid signal development of the non-isotopic approach with the previously unrivalled sensitivity of autoradiography. The procedure, which employs biotin labelled DNA probes and a streptavidin-alkaline phosphatase based detection system, is compatible with pre G-banding and can be performed on archival material. Unique sequences as small as 1 Kb are detectable. Using this technique, we have mapped the N-myc oncogene and the gene for beta-Nerve Growth Factor to 2p24 and 1p13 respectively.

Alkaline Phosphatase↗

PubMed1987

High-resolution in situ hybridization technique using biotinylated NMYC oncogene probe reveals periodic structure of HSRs in human neuroblastoma.

Gene amplification in mammalian cells commonly manifests itself as homogeneously staining chromosomal regions (HSRs). These are frequently seen in neuroblastoma and have been shown to be the site of amplification of the NMYC oncogene. We have used a nonisotopic, high-resolution in situ hybridization technique to reveal a hitherto unrecognized periodic microstructure within HSRs of a human neuroblastoma cell line.

Biotin↗

PubMed1986

Comparative studies between a new human rhabdomyosarcoma cell line, JR-1 and its tumour of origin.

A new human embryonal rhabdomyosarcoma cell line, designated JR-1, is described that closely resembles the tumour from which it was derived. Comparative studies, by light and electron microscopy reveal morphological features such as myofibre formation, that are concordant with embryonal rhabdomyosarcoma. Immunohistological investigations using a panel of monoclonal antibodies indicate that the cell surface antigen profile of the JR-1 cell line is similar to other embryonal rhabdomyosarcomas. In addition the cell line expresses the cytoplasmic intermediate filament protein desmin, only found in cells of rhabdoid origin. Karyotyping JR-1 shows the cells to contain variable numbers of chromosomes (range 44-100). DNA flow cytometry indicates that cells have an DNA content which is approximately twice normal. The JR-1 cell line has a doubling time of 29 h in culture and, in common with several other human cell lines, produces xenografts in nude mice within 6 weeks of inoculation. With detailed studies on the original tumour and the JR-1 cell line, the latter should prove an excellent model system for investigating the biology of rhabdomyosarcoma.

Animals↗