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Biomedical subjects

G Laureys

Publications and source records attributed to G Laureys.

At least 37 records · Page 2Linked to original sources
PubMed1997

Cutaneous involvement in children with acute lymphoblastic leukemia or lymphoblastic lymphoma. The Children's Leukemia Cooperative Group of the European Organization of Research and Treatment of Cancer (EORTC).

OBJECTIVE: Skin involvement in children with acute monocytic leukemia or CD30-positive anaplastic large-cell lymphoma is well-known. In contrast, very little is known about the malignant cutaneous infiltrates in children with acute lymphoblatic leukemia (ALL) or lymphoblastic lymphoma (LBL). This study was designed to determine the frequency of these specific lesions in childhood ALL or LBL and the characteristics of such patients. DESIGN: We studied the clinical and biological findings of children with cutaneous involvement at initial diagnosis of ALL or LBL enrolled between August 1989 and March 1995 in the multicentric trial 58881 of the Children's Leukemia Cooperative Group of the European Organization of Research and Treatment of Cancer (EORTC). RESULTS: Among the 1359 children enrolled in the multicenter trial EORTC 58881, 24 presented with skin involvement at diagnosis. ALL was diagnosed in 15 patients and LBL in 9. In 15 cases, skin lesions were observed within a median time of 6 weeks (range, a few days to 8 months) before the diagnosis of the hematologic disease. Twenty-one children had at least one skin lesion located on the head. Diffuse cutaneous lesions were observed in 7 infants with high-risk ALL. Seventeen of the 24 children remain in the first complete remission (median follow-up of 3 years; range 2 months to 5 years) and 3 are in the second remission with a follow-up of 14 to 24 months. CONCLUSION: The present study demonstrates that cutaneous involvement can be an early manifestation of ALL or LBL. Cutaneous leukemic infiltrates can be observed in children with standard risk as well as in high-risk ALL. Cutaneous involvement in children with LBL is mainly associated with a B-cell precursor immunophenotype of the lymphomatous cells. The most frequent location of skin lesions in children with ALL or LBL is on the head. Further studies are needed to evaluate the prognosis of children with such involvement at diagnosis.

Age Factors↗
PubMed1997

Monosomy 22 in a mixed germ cell-sex cord-stromal tumor of the ovary.

We report the cytogenetic findings in a case of mixed germ cell-sex cord-stromal tumor of the ovary in a 5-month-old girl. Monosomy 22 was observed as the sole karyotypic abnormality. This result was confirmed by comparative genomic hybridization, which revealed no additional chromosomal imbalances. This is the first observation of a chromosomal aberration in a mixed germ cell-sex cord-stromal tumor of the ovary. Monosomy 22 has been previously observed in granulosa cell tumors of the ovary. This could suggest a common pathogenetic pathway for both types of tumors.

Chromosomes, Human, Pair 22↗
PubMed1996

Allelic loss of chromosome 1p as a predictor of unfavorable outcome in patients with neuroblastoma.

BACKGROUND: Neuroblastoma is a childhood tumor derived from cells of the neural crest, with a widely variable outcome. Differences in the behavior and prognosis of the tumor suggest that neuroblastoma can be divided into several biologic subgroups. We evaluated the most frequent genetic abnormalities in neuroblastoma to determine their prognostic value. METHODS: We used Southern blot analysis to study the allelic loss of chromosomes 1p, 4p, 11q, and 14q, the duplication of chromosome 17q, and the amplification of the N-myc oncogene in 89 neuroblastomas. We also determined the nuclear DNA content of the tumor cells. RESULTS: Allelic loss of chromosome 1p, N-myc amplification, and extra copies of chromosome 17q were significantly associated with unfavorable outcome. In a multivariate analysis, loss of chromosome 1p was the most powerful prognostic factor. It provided strong prognostic information when it was included in multivariate models containing the prognostic factors of age and stage or serum ferritin level and stage. Among the patients with stage I, II, or IVS disease, the mean (+/- SD) three-year event-free survival was 100 percent in those without allelic loss of chromosome 1p and 34 +/- 15 percent in those with such loss; the rates of three-year event-free survival among the patients with stage III and stage IV disease were 53 +/- 10 percent and 0 percent, respectively. CONCLUSIONS: The loss of chromosome 1p is a strong prognostic factor in patients with neuroblastoma, independently of age and stage. It reliably identifies patients at high risk in stages I, II, and IVS, which are otherwise clinically favorable. More intensive therapy may be considered in these patients. Patients in stages III and IV with allelic loss of chromosome 1p have a very poor outlook, whereas those without such loss are at moderate risk.

Blotting, Southern↗
PubMed1996

Multiple polysomies in nasal polyps in children.

Karyotyping of a nasal polyp from a 10-year-old girl revealed multiple numerical chromosome changes. Extra copies of chromosome 5, 7, 8, 12, 16, 17, 18, 19, 20, and 21 were present. Only one cytogenetically abnormal nasal polyp of a child has been reported in the literature. The karyotypes of the reported and the present case are remarkably similar. The significance of this finding in a nonneoplastic proliferation is discussed.

Aneuploidy↗
PubMed1995

Constitutional translocation t(1;17)(p36.31-p36.13;q11.2-q12.1) in a neuroblastoma patient. Establishment of somatic cell hybrids and identification of PND/A12M2 on chromosome 1 and NF1/SCYA7 on chromosome 17 as breakpoint flanking single copy markers.

Cytogenetic and molecular studies in neuroblastoma suggest the presence of a tumor suppressor gene at the distal band p36 of human chromosome 1. We described a constitutional translocation t(1;17)(p36;q12-q21), involving the critical region 1p36, in a patient with neuroblastoma, and hypothesized that the translocation predisposed the patient to tumor development. Here we report the molecular delineation of the translocation breakpoints. Somatic cell hybrids were generated by fusion of the patient's fibroblasts with the thymidine kinase deficient hamster cell line, a3. In hybrid cell lines which retained the human derivative chromosomes, the position of chromosome 1p and 17q DNA probes respective to the translocation breakpoints was determined by fluorescence in situ hybridization and Southern blot analysis. The chromosome 1p breakpoint was localized within a repetitive region encoding t-RNA genes, with 12A-2 (PND) as most distal and pHE2.6 (A12M2) as most proximal single-copy breakpoint flanking markers. For the chromosome 17 breakpoint, the proximal and distal flanking markers were identified as 7G4 (NF1) and cMCP-3 (SCYA7), respectively. In this study, cMCP-3 (SCYA7), encoding the human monocyte chemotactic protein-3, was mapped between NF1 and ERBB2. As a pivotal step towards breakpoint cloning, at present these flanking markers optimally delineate the breakpoint regions of both chromosomes 1 and 17 at the molecular level.

Animals↗
PubMed1995

Balanced translocation in a neuroblastoma patient disrupts a cluster of small nuclear RNA U1 and tRNA genes in chromosomal band 1p36.

Chromosomal band 1p36 probably harbours several neuroblastoma suppressor genes. A neuroblastoma patient has been described with a constitutional balanced translocation, t(1;17)(p36;q12-21). Cytogenetically, no loss of chromosomal material was visible. The 1p36 translocation breakpoint could therefore have inactivated one allele of a tumour suppressor gene, thus predisposing the patient to develop neuroblastoma. We localized this breakpoint by pulsed field gel electrophoresis, analysis of yeast artificial chromosomes, and fluorescence in situ hybridization. Here we report that the breakpoint is within a large cluster of small nuclear RNA U1 (RNU1) and some tRNA genes (TRE, TRN) on chromosomal band 1p36. The size of this cluster is over two megabases and it contains many other locally repeated sequences. Polyadenylated transcripts were identified for some of these sequences. In addition, the cluster is the target for integration of an adenovirus 5/SV40 hybrid virus. The translocation breakpoint maps distal of this viral integration site and proximal of marker PND.

Animals↗
PubMed1995

Tropisetron in the prevention of nausea and vomiting in 131 children receiving cytotoxic chemotherapy.

Tropisetron (Navoban, Sandoz Pharma Ltd., Basel, Switzerland), a selective antagonist of the serotonin receptor (5-HT3) dosed once-daily at 0.2 mg/kg (with a maximum of 5 mg daily), was evaluated in the prevention of chemotherapy-induced nausea and vomiting in 131 children with a median age of 5 years (age 10 weeks to 21 years). Acute lymphocytic leukemia was the most common malignancy (49%). Most children (82%) had received cytotoxic chemotherapy before enrollment. Patients received tropisetron during one or more courses of chemotherapy (455 courses in total). Tropisetron was administered slowly intravenously as a single dose before the start of chemotherapy on day 1 and intravenously or by mouth the subsequent days as a single daily dose (median treatment duration: 5 days). Response to tropisetron per 24 hour period on the first 5 days of each chemotherapy course was graded as complete (absence of both nausea and vomiting), partial (one to four vomits and/or less than 5 hours of nausea), or failure. Overall complete response on day 1 was observed in 305 out of 455 chemotherapy courses (67%). The patients receiving intravenous chemotherapy (N = 92) had a 70% complete response rate and a 26% partial response rate on day 1, both for course 1 and course 2. The percentage of complete responders increased the subsequent days of the course. Emesis after day 1 was observed primarily during courses with the most emetogenic chemotherapy. No side-effects of tropisetron other than a single case of diarrhoea were documented in this study.

Adolescent↗
PubMed1995

Molecular cytogenetic analysis of 1;17 translocations in neuroblastoma.

Loss of chromosome 1 short arm material, resulting from terminal deletions or unbalanced translocations, is a frequent finding in advanced neuroblastoma. In translocations, often relatively small portions of a second chromosome are translocated to the chromosome 1 short arm. The chromosomal origin of this translocated material could often not be identified using banding analysis only. Recent studies, applying fluorescent in situ hybridisation, showed that in the majority of these translocations, chromosome 17 is involved. In this study, the nonrandom occurrence of unbalanced 1;17 translocations is further supported by their presence in 3/7 neuroblastoma cell lines. Analysis of the 1p breakpoints extends our earlier observation of breakpoint heterogeneity. A similar scattering of 17q breakpoints was observed. The 1p and 17q breakpoints of the constitutional 1;17 translocation did not coincide with any of the 1;17 translocation breakpoints found in neuroblastoma cell lines. Cell lines, not containing 1;17 translocations, contained other chromosome 17 rearrangements. As a result, extra copies of 17q are found in all cell lines, suggesting a role for genes on 17q in neuroblastoma development. The possible significance of 1;17 translocations in neuroblastoma is discussed.

Chromosome Mapping↗
PubMed1995

Characterisation of the chromosome breakpoints in a patient with a constitutional translocation t(1;17)(p36.31-p36.13;q11.2-q12) and neuroblastoma.

Cytogenetic and molecular studies in neuroblastoma suggest the presence of a tumour suppressor gene at the distal chromosome band 1p36. Previously, we hypothesised that a constitutional translocation involving the region 1p36 [t(1;17)(p36;q12-q21)] in a patient with neuroblastoma predisposed him to tumour development. Here we report the molecular delineation of the translocation breakpoints. Somatic cell hybrids containing the derivative chromosomes were used to determine the position of chromosome 1p and 17q DNA probes respective to the breakpoints using fluorescence in situ hybridisation. The 1p breakpoint was localised between the PND and D1S56 loci. The chromosome 17q breakpoint is flanked by NF1 and SCYA7, as proximal and distal marker, respectively. We redefined the translocation as t(1;17)(p36.31-13;q11.2-q12). The identification of flanking markers of the breakpoints is a prerequisite for breakpoint cloning and identification of a putative neuroblastoma suppressor gene.

Chromosome Mapping↗
PubMed1995

Evidence for two tumour suppressor loci on chromosomal bands 1p35-36 involved in neuroblastoma: one probably imprinted, another associated with N-myc amplification.

Previous reports on possible genomic imprinting of the neuroblastoma tumour suppressor gene on chromosome 1p36 have been conflicting. Here we report on the parental origin of 1p36 alleles lost in 47 neuroblastomas and on a detailed Southern blot analysis of the extent of the 1p deletions in 38 cases. The results are remarkably different for tumours with and without N-myc amplification. In the N-myc single copy tumours we show that the lost 1p36 alleles are of preferential maternal origin (16 of 17 cases) and that the commonly deleted region maps to 1p36.2-3. In contrast, all N-myc amplified neuroblastomas have larger 1p deletions, extending from the telomere to at least 1p35-36.1. These deletions are of random parental origin (18 of 30 maternal LOH). This strongly suggests that different suppressor genes on 1p are inactivated in these two types of neuroblastoma. Deletion of a more proximal suppressor gene is associated with N-myc amplification, while a distal, probably imprinted, suppressor can be deleted in N-myc single copy cases.

Chromosome Deletion↗
PubMed1995

Control of nausea and vomiting by Navoban (tropisetron) in 131 children receiving cytotoxic chemotherapy.

One hundred and thirty-one children with a median age of 5 years were administered Navoban (tropisetron), a selective antagonist of the serotonin receptor (5-HT3), dosed once daily at 0.2 mg/kg (with a maximum of 5 mg daily) in a study aimed at evaluating the prevention of nausea and vomiting induced by anti-cancer chemotherapy. The most common malignancy (in 49% of patients) was acute lymphocytic leukaemia. Patients received Navoban during one or more courses of emetogenic chemotherapy for a total of 455 courses administered intravenously or intravenously and intrathecally (IV + IT). Most patients (89%) had already received cytotoxic chemotherapy before enrollment for the trial. On Day 1, Navoban was administered slowly and intravenously as a single dose before the start of chemotherapy, or by mouth as a single daily dose on subsequent days (median treatment duration = 5 days). On the first 5 days of each course of chemotherapy, response to Navoban per 24-hour period was graded as: complete (absence of both nausea and vomiting), partial (1-4 vomits and/or less than 5 hours of nausea), or failure (more than 4 vomits and/or at least 5 hours of nausea). Ninety-six per cent of the intravenous chemotherapy group and 97% of the IV + IT chemotherapy group had a complete (70% and 55% respectively) or partial (26% and 42% respectively) response during the first 24-hour period of the first course in which Navoban was used. The second and subsequent courses yielded similar percentages. Delayed emesis was observed mainly during those courses employing the most emetogenic chemotherapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Case of recurrent Flavimonas oryzihabitans bacteremia associated with an implanted central venous catheter (Port-A-Cath): assessment of clonality by arbitrarily primed PCR.

Flavimonas oryzihabitans bacteremias, which occurred immediately after the flushing or use of an implanted central venous catheter (Port-A-Cath) in two patients at the same pediatric ward, were studied by arbitrarily primed PCR. We conclude that the colonization of the Port-A-Cath with F. oryzihabitans described here lasted for several months.

Bacteremia↗
PubMed1994

Chromosome aberrations in fibrous dysplasia.

We report the cytogenetic findings of two cases of fibrous dysplasia, one occurring in the tibia, the other in the sphenoid. Both cases exhibited only one chromosome change: a t(6;11)(q15;p15) in the first case, a derivative chromosome 2 in the second. The previous cytogenetic report on fibrous dysplasia revealed only numerical changes. The significance of these inconsistent chromosomal findings in fibrous dysplasia is unclear.

Adult↗
PubMed1994

The human MCP-3 gene (SCYA7): cloning, sequence analysis, and assignment to the C-C chemokine gene cluster on chromosome 17q11.2-q12.

Monocyte chemotactic proteins (MCPs) are chemokines involved in macrophage recruitment during inflammation and cancer. A full-size MCP-3 cDNA was used to isolate the functional human MCP-3 gene. Based on restriction analysis, subclones were selected and the MCP-3 gene sequence was completed. In addition to a dense region with direct and inverted repeats and palindromic sequences, a double microsatellite (CA)n-(GA)n' was found at the 5'-end of the MCP-3 gene, and an RFLP was detected. The gene was regionally mapped by fluorescence in situ hybridization to human chromosome 17, subbands q11.2-q12. This site contains the MCP-subset of C-C chemokines and can be distinguished from the syntenic MIP-1 alpha locus. SCYA7 was assigned as the locus symbol of the MCP-3 gene. Double-labeling experiments confirmed the regional assignment of the MCP-3 gene close to the ERBB2 locus on human chromosome 17.

Amino Acid Sequence↗
PubMed1994

1;17 translocations and other chromosome 17 rearrangements in human primary neuroblastoma tumors and cell lines.

We report on the finding of a t(1;17) in two primary neuroblastomas. Subsequent fluorescence in situ hybridization (FISH) analysis revealed the presence of 1;17 translocations in four out of nine neuroblastoma cell lines. The chromosome 1 short arm breakpoints were determined using region-specific probes. FISH screening also demonstrated or confirmed the presence of 11;17 translocations in three cell lines and other chromosome 17 rearrangements in those cell lines that did not carry a t(1;17) or t(11;17). Our data extend previous cytogenetic findings and suggest that, in addition to the known involvement of chromosome 1, one or more genes on chromosome 17 also play a role in neuroblastoma development.

Adrenal Gland Neoplasms↗
PubMed1994

A multimegabase cluster of snRNA and tRNA genes on chromosome 1p36 harbours an adenovirus/SV40 hybrid virus integration site.

Adenovirus type 12 (Ad12) induces gaps at chromosomal bands 1p36, 1q21, 1q42-43 and 17q21 after infection of human embryonic kidney cells. Three of these bands harbour small nuclear RNA genes or pseudogenes, but the study of a possible relationship has been hampered by the lytic character of adenovirus infection. A non-lytic Ad5/SV40 hybrid virus preferentially integrates at 1p36 and the integration site has been cloned. Chromosomal band 1p36 encodes genes for small nuclear RNA U1 (RNU-1) and for the tRNAs of glutamic acid (TRE) and asparagine (TRN). Each of these genes is encoded by 15-30 copies. We studied the organization of these genes and of the viral integration site by pulsed field gel electrophoresis (PFGE) and analysis of yeast artificial chromosomes (YACs). We show that RNU-1, TRE and TRN genes are scattered over a region of probably more than 2 Mb with intergenic distances of up to 125 kb. The Ad5/SV40 integration site maps to identical chromosomal NotI fragments as RNU-1 and TRE. Fine mapping of a YAC shows that the integration site is within 40-70 kb of genes for RNU-1, TRN and TRE.

Adenoviruses, Human↗
PubMed1993

High-resolution fluorescence mapping of 46 DNA markers to the short arm of human chromosome 1.

We describe a high-resolution cytogenetic map for 46 DNA markers previously assigned to the short arm of human chromosome 1. Using fluorescence in situ hybridization on simultaneously R-banded prometaphase chromosomes, a refined map position was found for 45 probes. For 6 of these probes, additional hybridization sites were observed and for another 7 probes, conflicting results were found with regard to previous localizations. For some probes with overlapping map positions, probe order could be determined by dual-color hybridization on elongated chromosomes. The present high-resolution map can be used to refine the previously published composite map and also provides additional landmarks for the construction of a contig map of the short arm of chromosomes 1.

Chromosome Mapping↗