Biomedical subjects

T Raap

Publications and source records attributed to T Raap.

4 recordsLinked to original sources

PubMed2000

Interphase FISH detection of BCL2 rearrangement in follicular lymphoma using breakpoint-flanking probes.

Rearrangement of the BCL2 gene is an important parameter for the differential diagnosis of non-Hodgkin lymphomas. Although a relatively large proportion of breakpoints is clustered, many are missed by standard PCR. A FISH assay is therefore desired. Up to now, a lack of probes flanking the BCL2 gene has limited the possibilities for a FISH assay to an approach based on colocalization of probes for BCL2 and the immunoglobulin heavy chain (IGH) locus. Intrinsically high rates of false positive nuclei and high interobserver variability make such assays unsuitable for use on lymphoma tissue samples, where tumor cells often form only a minority of the cell population. Using YAC end cloning techniques and screening of a PAC library, we have isolated PAC clones flanking the BCL2 gene. Using these PACs, and several cosmid clones in the second BCL2 intron, we developed a segregation-based interphase FISH assay with two probe combinations enabling separate detection of 5' and 3' (mbr/mcr) breakpoints. The assay was applied to a series of 40 follicular lymphomas. To evaluate the results, the same lymphomas were analyzed by DNA fiber FISH with a 600-kb set of BCL2 DNA clones labeled in alternating colors in combination with a color barcode covering the IGH locus. This approach allowed precise mapping of BCL2 breakpoints, and simultaneously showed juxtaposition of IGH genes to BCL2. Comparison of the results of interphase and fiber FISH showed complete correlation. Five cases were negative with both FISH techniques as well as with Southern blotting. Interestingly, all of these 5 cases lacked BCL2 overexpression as determined by immunohistochemistry, against 3 of 35 rearrangement-positive follicular lymphomas. Furthermore, absence of t(14;18) seemed to be correlated with a higher histologic grade (grades 2 and 3 according to Berard). These data indicate that the segregation-based interphase FISH assay detects 100% of BCL2 rearrangements. Because interpretation of the results is straightforward and requires no extensive experience, this assay may be the best available diagnostic test for BCL2 rearrangement. Genes Chromosomes Cancer 27:85-94, 2000.

3' Untranslated Regions↗

PubMed2000

Neurotransmitter modulation of interleukin 6 (IL-6) and IL-8 secretion of synovial fibroblasts in patients with rheumatoid arthritis compared to osteoarthritis.

OBJECTIVE: The sensory nervous system with the 2 neurotransmitters substance P (SP) and calcitonin gene related peptide (CGRP) is proinflammatory in experimental models of arthritis. The role of the sympathetic nervous system with norepinephrine (NE), adenosine, beta-endorphin, and methionine enkephalin (MENK) is not clearly understood. We studied the influence of these neurotransmitters on secretion of interleukin 6 (IL-6) and IL-8 in primary cultures of synovial fibroblasts of patients with rheumatoid arthritis (RA) compared to osteoarthritis (OA). METHODS: Fibroblasts were isolated using fresh synovial tissue of 5 patients with RA and 5 with OA who underwent knee joint replacement surgery. Modulation of spontaneous secretion of IL-6 and IL-8 was investigated in vitro using the neurotransmitters noted above. RESULTS: In RA fibroblasts, CGRP increased IL-6 and IL-8 secretion at 10(-10) to 10(-8) M (p at least < 0.01), which was not observed in OA fibroblasts. SP had no effect on either cytokine in RA fibroblasts but stimulated IL-8 secretion at 10(-8) M in OA fibroblasts (p < 0.01). In RA fibroblasts, adenosine and NE inhibited secretion of both cytokines at low concentrations (10(-8) M; p < 0.01). However, in OA fibroblasts there was a NE induced increase of IL-8 and IL-6 secretion at 10(-7) and 10(-6) M (p < 0.01), but no inhibition at lower concentrations (10(-8) M; p = NS). In RA fibroblasts, beta-endorphin and MENK inhibited IL-8 secretion at 10(-9) to 10(-7) M (p < 0.01), whereas in OA fibroblasts the dose response curve was shifted to lower concentrations (10(-12) M, 10(-11) M; p < 0.01). CONCLUSION: In OA fibroblasts, the sympathetic neurotransmitters were stimulatory at higher concentrations. CGRP was the most potent stimulatory neurotransmitter in RA fibroblasts whereas the sympathetic adenosine, NE, beta-endorphin, and MENK were inhibitory. This indicates a dualism of action of sympathetic and sensory neurotransmitters, with inhibitory and stimulatory effects on cytokine secretion of RA fibroblasts.

Aged↗

PubMed1995

Cytometry for CGH.

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In Situ Hybridization, Fluorescence↗

PubMed1990

Identification and characterization of normal length nonfluorescent Y chromosomes: cytogenetic analysis, southern hybridization and non-isotopic in situ hybridization.

In two female patients with a 45,X/46,X, +mar karyotype the marker chromosomes were identified as normal length nonfluorescent Y chromosomes (nlYnf) using non-isotopic in situ hybridization (NISH) complementary to routine cytogenetic analysis and Southern hybridization. The recognition of the nlYnf as isodicentric in both patients illustrates and confirms the usefulness and importance of NISH in the identification and characterization of this and many other types of complex chromosome rearrangements.

Adolescent↗