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J Fairman

Publications and source records attributed to J Fairman.

16 recordsLinked to original sources

Molecular anatomy of chromosome 7q deletions in myeloid neoplasms: evidence for multiple critical loci.

Complete or partial deletions of the long arm of chromosome 7 (7q- and -7) are nonrandom abnormalities seen in primary and therapy-induced myelodysplasia (MDS) and acute myelogenous leukemia (AML). Monosomy 7, occurring as the sole cytogenetic anomaly in a small but significant number of cases, may denote a dominant mechanism involving critical tumor suppressor gene(s). We have determined the extent of allele loss in cytogenetically prescreened MDS and AML patients for microsatellite markers from chromosome 7q22 and 7q31. Whereas >80% of these cases revealed allele loss for the entire region, a rare case of the 7q- chromosome showed allele loss for only the proximal 7q31.1 loci flanked by the markers D7S486 and D7S2456, and a case of monosomy 7 revealed allele loss for loci at both 7q31 and 7q22 with retention of sequences between these sets of loci. Furthermore, a case of AML with no cytogenetic anomaly of chromosome 7 revealed a submicroscopic allelic imbalance for a third distal locus, D7S677. These findings suggest the presence of three distinct critical loci that may contribute alone or in combination to the evolution of MDS and AML. The data also provide molecular evidence for unbalanced translocation with noncontiguous deletions, as an alternate mechanism underlying monosomy 7.

Chromosomes, Human, Pair 7

5q- in a child with refractory anemia with excess blasts: similarities to 5q- syndrome in adults.

A 19-month-old boy was referred to our institution because of chronic macrocytic anemia and severe thrombocytopenia. At age 17 months, he had developed petechiae. He had a leukocyte count of 4.4 x 10(9)/L, hemoglobin concentration of 7.9 g/dL, packed cell volume of 21%, mean corpuscular volume of 101 fL, and platelet count of 19 x 10(9)/L. At the time of referral, a bone marrow aspirate and biopsy revealed myelodysplastic changes that included megakaryocytic hyperplasia with hypolobated megakaryocytes, megaloblastoid erythropoiesis, 12% blast cells, and bone marrow fibrosis; the diagnosis was refractory anemia with excess blasts (RAEB). Cytogenetic analysis showed the following abnormalities: 47, XY, inv(3)(p21q25), del(5)(q22q31), +21/46, XY. By dinucleotide polymorphism analysis, the 5q22-q31 loci were normal in peripheral blood granulocytes. Because of severe thrombocytopenia that became refractory to platelet transfusions and because of possible progression to leukemia, the patient received an unrelated-donor bone marrow transplant. Recovery was complicated by a visceral fungal infection, but the patient now has normal, fully reconstituted bone marrow function. This patient is the youngest to be reported with RAEB and a 5q- anomaly accompanied by thrombocytopenia, megakaryocytic hyperplasia with hypolobated megakaryocytes, and macrocytic anemia with megaloblastoid erythropoiesis, similar to "5q- syndrome" in adults.

Anemia, Refractory

The unexplored 5q13 locus: a role in hematopoietic malignancies.

Deletions and translocations at 5q13 point out a locus involved in the development of acute myeloblastic leukemia (AML) and myelodysplastic syndromes (MDS) as well as other neoplasms. The chromosomal rearrangements of 5q13 are well documented, but have not been a primary focus of research. In this report, we provide evidence for a novel critical locus at 5q13.3, encoding gene(s) which may be disrupted by chromosomal translocations or deletions. Rare cases of myeloid neoplasms with t(5q13) as the sole chromosomal anomaly argue for a gene which gives rise to fusion proteins. Our preliminary studies have localized one of the critical genes to a <3 Mb. interval between the polymorphic markers AFMB347yf9 and GATAP18104 at the band 5q13.3. Other results also suggest that the 5q 13.3 locus may span a fragile site which undergoes unbalanced translocations and interstitial deletions accompanied by loss of significant segments of chromosome 5. Molecular reagents generated by the human genome mapping and sequencing initiative will allow us to characterize the critical genes at 5q13.3 and facilitate genotypic analysis of AML and MDS.

Chromosome Fragile Sites

Localization of SMAD5 and its evaluation as a candidate myeloid tumor suppressor.

Acquired interstitial or complete losses of chromosome 5 are recurring anomalies associated with preleukemic myelodysplasia and acute myelogenous leukemia with a poor prognosis. Previous studies have delineated a potential myeloid tumor suppressor locus to a <2.4-Mb interval between the genes for IL9 and EGR1 on 5q31. In this report, we have localized the SMAD5 gene, a homologue of the tumor suppressor genes SMAD4/DPC-4 and SMAD2/JV18.1, to the minimal myeloid tumor suppressor locus and characterized its open reading frame and genomic organization. SMAD5 transcripts are readily detectable in hematolymphoid tissues and leukemic blasts. Absence of intragenic mutations in the remaining SMAD5 allele of leukemic patients and multiple solid tumor cell lines prescreened for loss of heterozygosity suggests that SMAD5 may not be a common target of somatic inactivation in malignancy.

Base Sequence

Translocations and deletions of 5q13.1 in myelodysplasia and acute myelogenous leukemia: evidence for a novel critical locus.

Acquired partial and complete deletions of chromosome 5 (5q-, -5) are common cytogenetic anomalies associated with myelodysplasia (MDS) and acute myeloid leukemia (AML). A critical region of consistent loss at 5q31.1 (in > 90% of cases) has led us and others to postulate the presence of a key negative regulator(s) of leukemogenesis. Although the interstitial deletion limits vary among patients, del(5) (q13q33) and del(5)(q13q35) constitute major subsets. Furthermore, it is not rare to encounter deletions, translocations, or paracentric inversions involving 5q11 to 5q13, which indicates inactivation or disruption of important gene(s) at that locus. In this report, we have localized a novel locus at 5q13.1 to a 2.0-Mb interval between the anonymous markers D5S672 and GATA-P1804. This locus resided within the region of loss in 12 of 27 patients with anomalies of chromosome 5; one of these cases had apparent retention of both alleles of all the telomeric loci. Fluorescence in situ hybridization (FISH) studies demonstrate that the AML cell line ML3 is disrupted at 5q13.1 by a translocation involving chromosome 3, with apparent retention of the entire chromosome 5 sequence. Our results suggest that this novel proximal locus encodes a critical gene that may be deleted or disrupted in a subset of MDS/AML patients with chromosome 5 anomalies.

Adult

Physical mapping of the minimal region of loss in 5q- chromosome.

Acquired interstitial loss of all or part of the long arm of human chromosome 5 (5q-) is an anomaly that is seen frequently in patients with preleukemic myelodysplasia and acute myelogenous leukemia. Loss of a critical region of overlap at band 5q31.1 in all of these cases, with various cytogenetic breaks, signifies the existence of a key negative regulator of leukemogenesis. Previous studies have defined the proximal and distal ends of the critical region to reside between the genes for IL9 and EGR1, respectively. In this report, we describe a yeast artificial chromosome contig spanning this myeloid tumor suppressor locus. The combined order of the polymorphic loci is centromere-IL9-(D5S525-D5S558-D5S89-D5S526 -D5S393)-D5S399-D5S396-D5S414-EGR1 and telomere. The physical distance between the IL9 and EGR1 genes is estimated to be < 2.4 Mb. Here we report the utility of these polymorphic loci by detecting a submicroscopic deletion of 5q31; an acute myelogenous leukemia patient with a three-way translocation, t(5;18;17)(q31;p11;q11), as the sole anomaly revealed allele loss of the D5S399 and D5S396 loci.

Alleles

Consistent loss of the D5S89 locus mapping telomeric to the interleukin gene cluster and centromeric to EGR-1 in patients with 5q- chromosome.

Interstitial deletions of the long arm of chromosome 5 are common in a number of disorders of leukemic and preleukemic myeloid disorders. Although the limits of these deletions vary among patients, a region of cytogenetic overlap that includes band 5q31 is deleted consistently, suggesting loss of 5q31 loci critical for normal myeloid differentiation and leukemogenesis. An anonymous genomic DNA segment D5S89, previously mapped to 5q21-31, detects consistent loss of alleles in cases showing the 5q- chromosome at presentation or relapse. Analysis of a panel of natural-deletion somatic-cell hybrids in conjunction with irradiation hybrids containing fragments of human chromosome 5q shows that the D5S89 locus is telomeric to the interleukin (IL) genes (IL-3, IL-4, IL-5, IL-9, and granulocyte-macrophage colony-stimulating factor [GM-CSF]) and interferon response factor-1 (IRF-1) gene and centromeric to the early response transcription factor (early growth response gene-1 [EGR-1]) on 5q31. To further define the principal region of loss, we have isolated and characterized yeast artificial chromosomes (YACs) spanning D5S89. The presence of several CpG islands within the 300-kb YAC is suggestive of multiple transcription units. However, IL-4, IL-5, IRF-1, IL-3, GM-CSF, and EGR-1 genes were not detected in the YAC clone spanning D5S89, implying that none of these genes are in the vicinity of the D5S89 marker. Further characterization of these YACs should facilitate the isolation of novel candidate genes that may play a role in the evolution of the abnormal phenotype associated with 5q- chromosome.

Adult

Development of a sensitive PCR to detect allele loss in a model hematopoietic neoplasm.

Loss or gain of an entire chromosome and interstitial deletions or amplifications are hallmarks of several hematopoietic neoplasms. These chromosomal anomalies can be identified by conventional cytogenetic analysis of bone marrow aspirates. We have developed a PCR-based assay to detect loss of chromosome 5q31 loci, in the model system of myeloid disorders with the 5q- chromosome (interstitial deletion of 5q), by taking advantage of a highly polymorphic dinucleotide repeat within the interleukin-9 (IL9) gene on 5q31. In a given sample, quantitation of amplification of individual alleles in a Phosphorimager allowed the representation of alleles to be expressed as a ratio of the larger to the smaller allele. Comparison of these ratios in paired DNA samples from Ficoll buoyant and pelletted fractions provides evidence for allele loss. Results presented here demonstrate that this technique of comparison of ratios of isotope incorporation could be expanded to Investigate any deletion or numerical abnormality in hematopoietic tumors.

Alleles

New nurses, new spaces: a preview of the AACN History Study.

This article previews selected findings of the American Association of Critical-Care Nurses History Project that is being conducted under the auspices of the Center for the Study of the History of Nursing at the University of Pennsylvania. Using methods of social history research, we reviewed pertinent literature, studied documents of institutions and organizations, and interviewed a broad array of participants. Analysis of this evidence resulted in a history of the evolution of nursing and hospital care for patients with life-threatening illnesses during the 40-year period since 1950. We explored the effects of changing public and professional ideas about the nature of critical illness, the effects of technology, and the historical dimensions of critical care nursing. Special attention was given to the events and circumstances that led to the development of AACN and the reciprocal relationships between AACN and the care of critically ill people.

Critical Care