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Biomedical subjects

D Pinkel

Publications and source records attributed to D Pinkel.

At least 73 records · Page 4Linked to original sources
PubMed1994

Detection of a human chromosomal translocation t(8;9) in a baby with multiple malformations using two-color fluorescence in situ hybridization.

A human chromosomal translocation t(8;9) was detected using two-color fluorescence in situ hybridization with probes capable of staining the entire lengths of each of these chromosomes. The chromosome 8 probe was labeled with biotin and detected with Texas red, while the chromosome 9 probe was labeled with AAF and detected with FITC. In normal metaphase spreads, two metaphases from the proband, two red, one green and one part red and part green derivative chromosome were seen. The bicolor chromosome corresponded to translocation of a chromosome 8 segment to the distal part of the q region of one chromosome 9, as originally indicated by banding analysis. In interphase nuclei of the proband, four domains with bright fluorescence were recognized in many nuclei. Two were red, one was green, and the fourth had portions of both colors, indicating the presence of the translocation.

Abnormalities, Multiple↗
PubMed1994

High-dose mercaptopurine followed by intermediate-dose cytarabine in relapsed acute leukemia.

PURPOSE: This phase I/II study was designed to explore the feasibility, toxicity, and potential efficacy of administering high-dose continuous intravenous mercaptopurine (6MP) followed by intermediate-dose continuous intravenous cytarabine (Ara-C) to children with relapsed or unresponsive acute leukemia. PATIENTS AND METHODS: Twenty-three children with relapsed or unresponsive acute leukemia (13 myeloid, 10 lymphoid) were entered onto the study. After initial hydration and alkalinization, 1,000 or 1,250 mg/m2 of 6MP was administered by continuous intravenous infusion over 24 hours. Following another period of hydration, 500 mg/m2 of Ara-C was administered by continuous intravenous infusion daily for 4 days. In 17 children, plasma concentrations of 6MP were measured at hours 4, 24, and 27 of the 6MP infusions. Plasma concentrations of Ara-C were measured at hours 8, 24, 48, 72, and 96 of the Ara-C infusions. Intracellular Ara-C triphosphate (Ara-CTP) concentrations were measured in peripheral-blood leukemia cells of the five patients with sufficient cells for measurement. Children who developed remission received repeated courses of this regimen every 3 to 4 weeks until relapse or completion of 12 courses. RESULTS: Of 13 children with acute myeloid leukemia (AML), six developed complete remissions (CRs) lasting 7 months to nearly 4 years. Two children remain in CR with normal growth, development, and health 3 years after cessation of treatment. Of 10 children with acute lymphoid leukemia (ALL), one had a CR of 2 months' duration. Dose-limiting toxicity consisted of severe hematosuppression with fever, neutropenia, and serious infection. There were two toxic deaths. The mean steady-state plasma concentrations of 6MP were approximately 4 mumol/L and of Ara-C approximately 3 mumol/L. The median Ara-CTP concentration in peripheral-blood leukemia cells was 308 mumol/L at hour 8 of the Ara-C infusion. CONCLUSION: High-dose continuous intravenous 6MP followed by intermediate-dose intravenous Ara-C produced CRs of longer than 6 months in approximately half of children with relapsed or unresponsive AML. Further study of this drug regimen is justified.

Acute Disease↗
PubMed1994

Comparison of two schedules of intermediate-dose methotrexate and cytarabine consolidation therapy for childhood B-precursor cell acute lymphoblastic leukemia: a Pediatric Oncology Group study.

PURPOSE: To compare efficacy and toxicity of two schedules of intermediate-dose methotrexate (IDM) and cytarabine (Ara-C) in remission consolidation of childhood acute lymphoblastic leukemia (ALL). PATIENTS AND METHODS: In 1986, the Pediatric Oncology Group (POG) began a randomized trial to test two schedules of consolidation chemotherapy in children with newly diagnosed B-precursor cell ALL. MTX and Ara-C were given as overlapping 24-hour infusions. The dose and sequence of MTX and Ara-C administration were based on a preclinical model that had demonstrated synergism between these two agents. Two hundred fifteen patients in complete remission were randomized to front-loading consolidation therapy in which six MTX/Ara-C infusions were administered at 3-week intervals from the 7th through the 19th week of therapy. Two hundred thirteen patients in complete remission were randomized to receive standard consolidation therapy in which the six MTX/Ara-C infusions were given every 12 weeks from the 7th through the 67th week of therapy. RESULTS: Both regimens produced similar rates of adverse side effects, except for a higher incidence of CNS toxicity in individuals randomized to the front-loading arm (32 of 215 v 12 of 213 patients, P = .002). Leukoencephalopathy occurred in three patients on the front-loading regimen and was permanent in one. By Kaplan-Meier analysis, the probability of continuing in complete remission for 5 years was 79% (SE = 5%) and 85% (SE = 5%) for good-risk patients, and 66% (SE = 6%) and 61% (SE = 7%) for poor-risk patients randomized to front-loading and standard regimens, respectively. CONCLUSION: Although differences in complete remission durations were not statistically significant by log-rank analysis (P = .62 for good-risk patients, .89 for poor-risk patients, and .99 overall), the results are comparable to those in previous studies using more toxic agents as components of remission consolidation therapy.

Adolescent↗
PubMed1994

Fluorescence in situ hybridization in cancer and radiation biology.

This review describes molecular cytogenetic approaches to genetic analysis including fluorescence in situ hybridization, primed in situ labeling and comparative genomic hybridization. It also summarizes the applications of this technology to physical mapping, cancer diagnosis and prognostication and in radiation biology.

Animals↗
PubMed1993

Treatment of acute lymphoblastic leukemia. 30 years' experience at St. Jude Children's Research Hospital.

BACKGROUND: Therapy for childhood lymphoblastic leukemia has evolved during the past three decades, but key questions about what are the least toxic, most effective forms of treatment remain unanswered because of the lack of comprehensive follow-up information. METHODS: To assess long-term outcome in the series of clinical trials conducted at St. Jude Hospital, we compared the results of treatment typical of four eras: exploratory combination chemotherapy (era 1, 1962 to 1966; 91 patients), regimens for the control of meningeal leukemia (era 2, 1967 to 1979; 825 patients), limited intensification of therapy (era 3, 1979 to 1983; 428 patients), and extended intensification of therapy (era 4, 1984 to 1988; 358 patients). ("Intensification" refers to strategies of systemic chemotherapy that are more aggressive than conventional ones.) The major end points were survival and event-free survival; we also calculated the relative risk of treatment failure and the rate of relapse or death after treatment ended (post-treatment failure rate). RESULTS: The probability of event-free survival improved significantly in each successive era (P < 0.001 by the log-rank test), reaching 71 percent in era 4. There was a decrease of approximately 50 percent in the risk of treatment failure from one era to the next in each subgroup of patients defined according to different combinations of the leukocyte count, race, age, and sex. Leukemia appeared to be eradicated in patients who remained in complete remission for three years or more after treatment in era 4. The incidence of death due to nonleukemic causes remained 4 to 6 percent despite the trend toward more intensive treatment. An estimated 765 patients (45 percent) are long-term survivors; most of them (80 percent) have no health problems related to leukemia or its treatment. CONCLUSIONS: The development and successful application of preventive therapy for meningeal leukemia, followed by the intensification of systemic chemotherapy, has progressively improved the rate of cure of childhood lymphoblastic leukemia, with relatively few adverse sequelae.

Adolescent↗
PubMed1993

Intravenous mercaptopurine: life begins at 40.

PURPOSE: This review is intended to provide a concise portrayal of the background, rationale, and current use of intravenous infusions of mercaptopurine (6MP) in patients with acute leukemia. DESIGN: After a brief description of the mode of action of 6MP and the formulation, pharmacokinetics, and history of its intravenous administration, the rationale for current use of intravenous 6MP infusion is explained. Subsequently, the review summarizes and discusses clinical experience with intravenous 6MP alone and in combination with intravenous methotrexate (Mtx) and cytarabine (Ara-C). RESULTS: Although still an investigative drug, intravenous 6MP has been used for 40 years and currently is being administered extensively to children with previously untreated acute lymphoid leukemia (ALL) in frontline protocol studies. The reasons are the better and more consistent bioavailability of intravenous versus oral MP, higher blood and CSF levels, compliance, and preliminary evidence suggesting superior remission experience for intravenous Mtx and 6MP than for Mtx alone. The apparent lack of late adverse sequelae with 6MP as compared with other antileukemia drugs adds to this interest. CONCLUSION: The new life of intravenous 6MP at age 40 years illustrates the need for continued investigation of significant anticancer drugs as insights and technology progress.

Acute Disease↗
PubMed1993

Libraries for each human chromosome, constructed from sorter-enriched chromosomes by using linker-adaptor PCR.

We describe here the production of complex libraries enriched in sequences from each human chromosome type, starting with only a few thousand sorter-purified chromosomes. In this procedure, DNA is extracted from the sorted chromosomes, digested to completion by using the frequently cutting restriction endonuclease Sau3A1, and ligated, on each end, to an adaptor oligonucleotide. These fragments are then amplified using PCR with a sequence homologous to the adaptor oligonucleotide as a primer. We have used this procedure to produce PCR libraries for each of the 24 human chromosomes. These libraries were characterized by gel electrophoresis and found to be composed of a continuum of sequences ranging in size from a few hundred to approximately 1,000 bp. The libraries, when used as probes for fluorescence in situ hybridization, stained the target chromosomes more or less continuously, even after PCR amplification for more than 200 cycles. These libraries are useful as hybridization probes to facilitate molecular cytogenetic studies and as sources of probes either for identification of polymorphic short tandemly repeated sequences or for development of sequence-tagged sites.

Base Sequence↗
PubMed1993

Comparative genomic hybridization: a rapid new method for detecting and mapping DNA amplification in tumors.

Recent evidence indicates that many more genes than the currently known oncogenes may undergo amplification in tumors. We have developed a new technique, Comparative Genomic Hybridization (CGH), which allows rapid detection of DNA amplification anywhere in the tumor genome and maps the amplified sequences on normal chromosomes. CGH is based on a competitive in situ hybridization of differentially labeled tumor DNA and normal DNA to a normal human metaphase spread. Regions of gain of DNA sequences are seen as an increased color ratio of two fluorochromes used to detect the labeled DNAs. Over 20 different regions of amplification have been identified using CGH.

Chromosome Mapping↗
PubMed1993

Detection of aneuploid human sperm by fluorescence in situ hybridization: evidence for a donor difference in frequency of sperm disomic for chromosomes 1 and Y.

Fluorescence in situ hybridization with repetitive-sequence DNA probes was used to detect human sperm disomic for chromosomes 1 and Y in three healthy men. Data on these same men had been obtained previously, using the human-sperm/hamster-egg cytogenetic technique, providing a cytogenetic reference for validating sperm hybridization measurements. Air-dried smears were prepared from semen samples and treated with DTT and lithium diiodosalicylate to expand sperm chromatin. Hybridization with fluorescently tagged DNA probes for chromosomes 1 (pUC177) or Y (pY3.4) yielded average frequencies of sperm with two fluorescent domains of 14.2 +/- 2.4/10,000 and 5.6 +/- 1.6/10,000 sperm, respectively. These frequencies did not differ statistically from frequencies of hyperploidy observed for these chromosomes with the hamster technique. In addition, frequencies of disomic sperm from one donor were elevated approximately 2.5-fold above those of other donors, for both chromosomes 1 (P = .045) and Y (P = .01), consistent with a trend found with the hamster technique. We conclude that fluorescence in situ hybridization to sperm chromosomes provides a valid and promising measure of the frequency of disomic human sperm.

Aneuploidy↗
PubMed1992

Comparative genomic hybridization for molecular cytogenetic analysis of solid tumors.

Comparative genomic hybridization produces a map of DNA sequence copy number as a function of chromosomal location throughout the entire genome. Differentially labeled test DNA and normal reference DNA are hybridized simultaneously to normal chromosome spreads. The hybridization is detected with two different fluorochromes. Regions of gain or loss of DNA sequences, such as deletions, duplications, or amplifications, are seen as changes in the ratio of the intensities of the two fluorochromes along the target chromosomes. Analysis of tumor cell lines and primary bladder tumors identified 16 different regions of amplification, many in loci not previously known to be amplified.

Chromosome Mapping↗
PubMed1992

ERBB2 amplification in breast cancer analyzed by fluorescence in situ hybridization.

We illustrate the use of fluorescence in situ hybridization (FISH) for analysis of ERBB2 oncogene copy number, the level of amplification (here defined as the ratio of ERBB2 copy number to copy number of chromosome 17 centromeres), and the distribution of amplified genes in breast cancer cell lines and uncultured primary breast carcinomas. The relative ERBB2 copy number determined by FISH in 10 breast cancer cell lines correlated strongly with Southern blot results (r = 0.98) when probes for an identical reference locus were used in the two methods. Metaphase analysis of cell lines showed that amplified ERBB2 copies always occurred in intrachromosomal clusters but that the number and chromosomal location of these clusters varied among the cell lines. In interphase nuclei of primary tumors showing ERBB2 amplification (10/44), ERBB2 copies were seen as one to four clusters, also suggesting intrachromosomal localization. Regardless of the average level of amplification, all these tumors contained highly amplified cell subpopulations with at least 25, and sometimes more than 100, ERBB2 copies per cell. Tumors that did not show amplification by FISH (34/44) had an average of one to five ERBB2 copies scattered randomly in the nuclei and completely lacked cells with high copy levels. FISH results on primary tumors were concordant with slot blot results on amplification and with immunohistochemical detection of overexpression. Quantitative analysis of ERBB2 amplification by FISH may improve prognostic assessments based on the pattern of amplification and detection of heavily amplified tumor cell subpopulations.

Breast Neoplasms↗
PubMed1992

Deletion of chromosome 17p loci in breast cancer cells detected by fluorescence in situ hybridization.

Allelic loss of tumor suppressor genes on chromosome 17p has been implicated in the progression of breast cancer. This is in principle detectable by fluorescence in situ hybridization if the loss occurs by deletion. In order to determine if detectable deletions occur in primary breast cancer, we used dual-color hybridization with chromosome 17 pericentromeric and region-specific DNA probes to study 19 primary breast cancers. The copy numbers of 17 centromere and 17p13.1 sequences were compared with the loss of heterozygosity (LOH) for probe YNZ22 at 17p13.3 detected by restriction fragment length polymorphism. Nine of 11 cases showing LOH also showed the major population of nuclei with a deletion. The remaining two tumors with LOH were trisomic for both the centromere and 17p13.1 cosmid. In contrast, seven of eight tumors without LOH had no deletions by fluorescence in situ hybridization. These data suggest that the dominant mechanism of allelic loss at 17p in breast cancer is a physical deletion and that analysis of deletions by fluorescence in situ hybridization is a rapid and sensitive approach to studying chromosomal aberrations.

Alleles↗
PubMed1992

Molecular cytogenetics in human cancer diagnosis.

This report summarizes the application of fluorescence in situ hybridization for detection and diagnosis of human cancers and for detection of residual cancer cells. This approach allows individual interphase cancer cells to be stained so that aberrations such as aneusomies, translocations, deletions, and gene amplification can be seen in the light microscope. This is accomplished using probes for repeated sequences found at the chromosome centromeres, whole chromosome probes, and/or probes for specific aberrant sequences.

Chromosome Aberrations↗
PubMed1992

Molecular cytogenetics: diagnosis and prognostic assessment.

This review describes molecular cytogenetic techniques for detection and characterization of genetic aberrations associated with human disease. The techniques of fluorescence in situ hybridization, primed in situ labeling and comparative genome hybridization are described, as are probes for repeated sequences, whole chromosomes and specific loci. Also reviewed are applications of these technologies to pre- and neonatal diagnosis and to the characterization of human malignancies.

Base Sequence↗
PubMed1992

Lessons from 20 years of curative therapy of childhood acute leukaemia.

The past 20 years of curative therapeutics of childhood acute leukaemia has been largely a period of consolidation of gains, refinement of techniques and dissemination of expertise and technology. However, certain lessons have been learned. First, cure can be permanent but the complexity and cost of curative treatment currently restricts its accessibility; prevention or simple curative treatment is needed. Secondly, cure of the child demands that the risk of adverse sequelae of treatments be carefully balanced with known therapeutic benefits. Thirdly, preventive meningeal irradiation is no longer required. Fourth, treatment intensification is self-limiting. Adverse reactions can cancel out or exceed therapeutic benefits, resulting in a lower cure rate or a similar cure rate with lower quality of cure. Finally, morphology, immunophenotype and genotype of acute leukaemia are important criteria for selecting and scheduling drug therapy. Genotype may be the most important since leukaemia is a genetic disorder for which morphology and immunophenotype are mere reflections. However, none of these features, individually or together, are sufficient to explain all the difference in outcome among children on a given treatment plan or to completely fulfill the need of criteria for selection of treatment. Acute leukaemia remains an unsolved problem demanding considerably more basic and clinical research to meet the need for prevention and simple dependable curative treatment.

Acute Disease↗