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At least 19 recordsLinked to original sources
PubMed1989

Chromosome 22 breakpoints in variant Philadelphia translocations and Philadelphia-negative chronic myeloid leukemia.

The standard t(9;22)(q34;q11) found in Philadelphia (Ph) chromosome positive chronic myeloid leukemia (CML) involves a highly restricted (5.8 kb) chromosome 22 breakpoint cluster region (bcr), which results in the formation of a chimeric gene comprising exons from the 5' end of bcr and protooncogene c-abl coding sequences from chromosome 9. In a survey of 21 patients with hematologic and clinical features of CML we detected rearrangement of the chromosome 22 bcr by gene probe analysis in all cases, including 16 with a standard t(9;22), two with variant Ph translocations [t(10;22)(q26;q11);t(11;22)(p15;q11)], one with a complex Ph translocation [t(9;11;22)(q34;q13;q11)], one with a complex translocation and a masked Ph[t(9;14;22) (q34;q24;q11)], and one Ph-negative case with a t(1;9)(p32;q34). These observations further substantiate the suggestion that, despite karyotypic heterogeneity, a common underlying molecular lesion, the bcr-abl gene chimera, is involved in the disease pathogenesis of CML.

Adult↗
PubMed1989

Philadelphia chromosome negative acute lymphoblastic leukemia preceding Philadelphia positive chronic myelogenous leukemia.

A patient with Philadelphia chromosome (Ph) negative acute lymphoblastic leukemia (ALL, FAB type L1) developed Ph-positive chronic myelogenous leukemia (CML) after more than 2 years in complete remission. Subsequently, Ph-positive lymphoblastic transformation occurred, which was again successfully treated. Thereafter, the CML state was interrupted twice more by blast crisis. The additional chromosomal abnormalities were atypical for Ph-positive CML. The course is interpreted as a possible example of the multistep development of CML. Blastic transformation occurring prior to the Ph chromosome has been reported in only two cases previously.

Adult↗
PubMed1991

Essential thrombocythemia with the Philadelphia chromosome and BCR-ABL gene rearrangement. An entity distinct from chronic myeloid leukemia and Philadelphia chromosome-negative essential thrombocythemia.

A 64-year-old woman presented with a platelet count of 3,225 x 10(9)/L. Bone marrow morphology showed massive megakaryocytic hyperplasia; cytogenetic studies showed the presence of the Philadelphia chromosome (Ph). The presence of a rearrangement involving the major breakpoint cluster region (mbcr) on chromosome 22 was confirmed by Southern blotting techniques. A diagnosis of Ph positive essential thrombocythemia (ET) was made. Such cases constitute less than 5% of patients with ET and it has been proposed that they be considered examples of chronic myelogenous leukemia (CML) because of a shared propensity to progress to blast crisis. An argument is presented for retaining Ph positive ET as an entity separate from Ph negative ET and Ph positive CML.

Blotting, Southern↗
PubMed1992

Specific point mutations that activate v-abl are not found in Philadelphia-negative chronic myeloid leukaemia, Philadelphia-negative acute lymphoblastic leukaemia or blast transformation of chronic myeloid leukaemia.

The involvement of the BCRlABL fusion gene in patients with Philadelphia (Ph) chromosome positive chronic myeloid leukaemia (CML) and acute lymphoblastic leukaemia (ALL) is well characterised, but the molecular events underlying the cases of Ph-negative CML and ALL that lack BCR gene involvement and those that cause transformation of Ph-positive CML are unknown. The murine ABL gene can be activated by genetic events that do not involve the BCR gene, including the introduction of two specific point mutations in exons VII and XI respectively, as found in the homologous sequence of the v-abl oncogene. We therefore sought evidence for analogous point mutations in the ABL gene in patients with Ph-negative, BCR-negative CML (n = 25), Ph-negative ALL (n = 18) and in Ph-positive CML in transformation (n = 28). We used restriction fragment length polymorphism and single strand conformational polymorphism techniques to analyse DNA amplified fragments of selected ABL coding regions from leukaemia cells. We identified only normal wild-type DNA sequences. The absence of these transforming point mutations does not exclude the possibility that the ABL gene in such patients could be activated by other means.

Adult↗
PubMed1975

[Myelomonocytic leukemia with Philadelphia-positive and Philadelphia-negative cell lines in early childhood (author's transl)].

The authors report on an infant with myeloproliferative syndrome of the myelomonocytic type. The findings fulfilled the criteria for juvenile chronic myeloid leukemia except that there was no increase of fetal hemoglobulin and no depression of erythrocyte carbonic anhydrase I. In one half of the bone marrow cells a Ph1-chromosome was found. During the course of the disease the Ph1-positive clone was successively replaced by cell lines with different chromosomal aberrations. The relationship between the cytogenetic mosaicism and the clinical and laboratory findings is discussed.

Adult↗
PubMed1986

Use of the Philadelphia collar as an alternative to the halo vest in patients with C-2, C-3 fractures.

We analyzed retrospectively 27 individuals with C-2, C-3 fractures, 8 of whom were treated with a Philadelphia collar rather than the more commonly used halo vest. Successful fusion without neurological deficit occurred in all cases whether treatment was by Philadelphia collar (n = 8), halo apparatus (n = 16), or prolonged bed rest (n = 3). There was an increase in subluxation in 3 patients in both the Philadelphia collar group and the halo apparatus group. However, 1 of the 3 in the collar group was uncooperative and discarded his collar during treatment. If he is excluded, the subluxation rate in the Philadelphia collar group is 27%; the rate in the halo group is 19%. The Philadelphia collar seems to be an acceptable means of stabilizing the neck in C-2, C-3 fractures, but one must consider the degree of cervical movement in the collar (as detected by dynamic x-ray films), patient reliability, and patient age. The presence of subluxation did not preclude successful fusion in either the Philadelphia collar or the halo vest groups.

Adolescent↗
PubMed1987

The effect of long-term marrow culture on the nonadherent Philadelphia chromosome-positive clone in chronic myelogenous leukemia: preliminary observations.

To evaluate the effect of long-term culture on the Philadelphia chromosome-positive nonadherent hemopoietic clone in chronic myelogenous leukemia, bone marrow aspirates from five patients were grown in culture for three to four weeks. In addition to control cultures, samples were incubated with recombinant alpha-interferon. Cytogenetic studies performed on the nonadherent hemopoietic cells demonstrated suppression of the Philadelphia chromosome-positive clones, and appearance of cells with normal diploid karyotype in two of the five patients studied; cells from the remaining three patients showed persistent Philadelphia chromosome-positive cells in 100% of the metaphases. Exposure to alpha-interferon did not enhance the suppression of the Philadelphia chromosome-positive clones. A good correlation was noted between in vitro results and in vivo cytogenetic response: the two patients whose in vitro studies showed diploid clones achieved complete hematologic remission and suppression of Philadelphia chromosome-positive metaphases with therapy. Our data suggest that long-term culture favors the growth of normal clones over Philadelphia chromosome-positive clones in the nonadherent hemopoietic cells of some patients with chronic myelogenous leukemia. The value of the procedure as an in vitro predictive test for residual normal stem cells and response to therapy and for autologous marrow in vitro purging needs further exploration.

Adult↗
PubMed1989

Localization of preferential sites of rearrangement within the BCR gene in Philadelphia chromosome-positive acute lymphoblastic leukemia.

The Philadelphia chromosome associated with acute lymphoblastic leukemia (ALL) has been linked to a hybrid BCR/ABL protein product that differs from that found in chronic myelogenous leukemia. This implies that the molecular structures of the two chromosomal translocations also differ. Localization of translocation breakpoints in Philadelphia chromosome-positive ALL has been impeded due to the only partial characterization of the BCR locus. We have isolated the entire 130-kilobase BCR genomic locus from a human cosmid library. A series of five single-copy genomic probes from the 70-kilobase first intron of BCR were used to localize rearrangements in 8 of 10 Philadelphia chromosome-positive ALLs. We have demonstrated that these breakpoints are all located at the 3' end of the intron around an unusual restriction fragment length polymorphism caused by deletion of a 1-kilobase fragment containing Alu family reiterated sequences. This clustering is unexpected in light of previous theories of rearrangement in Philadelphia chromosome-positive chronic myelogenous leukemia that would have predicted a random dispersion of breakpoints in the first intron in Philadelphia chromosome-positive ALL. The proximity of the translocation breakpoints to this constitutive deletion may indicate shared mechanisms of rearrangement or that such polymorphisms mark areas of the genome prone to recombination.

Base Sequence↗
PubMed1986

Clinical and prognostic features of Philadelphia chromosome-negative chronic myelogenous leukemia.

Between 1965 and 1982, 105 patients with a diagnosis of Philadelphia chromosome-negative chronic myelogenous leukemia were referred to our institution with minimal or no prior therapy. The median age was 63 years and 64% were males. The overall median survival from time of referral was 14 months; 53% of patients survived 1 year and only 10% survived beyond 5 years. At the time of analysis, 92 patients (88%) were dead, 56% of deaths being preceded by a blastic crisis. Compared with Philadelphia chromosome-positive disease, patients with Philadelphia chromosome-negative chronic myelogenous leukemia were older and had a significantly higher incidence of anemia, thrombocytopenia, monocytosis, marrow blasts, decreased marrow megakaryocytes and a lower incidence of basophilia and thrombocytosis. Chromosomal abnormalities occurred in 33% of patients and consisted most frequently of trisomy 8, or an additional chromosome C, loss of the Y chromosome, or abnormalities in chromosomes #5 and #7. Of nine pretreatment characteristics significantly associated with poor survival, a multivariate analysis identified four to have independent additive prognostic significance: severe thrombocytopenia, hemoglobin levels less than 10 g/dl, increasing peripheral blasts and promyelocytes, and age 60 years or older. Monocytosis was not of prognostic significance. The derived prognostic model divided patients into three risk groups, low, intermediate, and high, with median survivals of 36, 16, and 3 months, respectively. The authors conclude that Philadelphia chromosome-negative chronic myelogenous leukemia is a distinct entity among the myeloproliferative syndromes with characteristic clinical and laboratory features and a poor prognosis. Prognostic factors and related risk categories were demonstrated within this disease entity.

Adolescent↗
PubMed1988

Clinical presentation and natural history of patients with essential thrombocythemia and the Philadelphia chromosome.

Six women presented with the clinical picture of essential thrombocythemia (ET) without the anemia, marked splenomegaly, and extreme leukocytosis characteristic of chronic myelogenous leukemia (CML). All had the Philadelphia chromosome on karyotype analysis of the bone marrow. Peripheral basophilia was present in four cases, providing a clinical clue that the Philadelphia chromosome might be present. Marrow biopsy showed granulocytic hyperplasia and either small megakaryocytes or sheets of megakaryocytes with marked atypia, findings that are more typical of CML than ET. The clinical importance of finding the Philadelphia chromosome in patients who seem to have ET is in assessing prognosis. ET generally follows a chronic, indolent course. However, five of these six patients who had the Philadelphia chromosome underwent clinical transition to the accelerated phase of CML or blastic leukemia in 4-7 years.

Adult↗
PubMed1988

Heterogeneity of genomic fusion of BCR and ABL in Philadelphia chromosome-positive acute lymphoblastic leukemia.

Philadelphia chromosome-positive acute lymphoblastic leukemia occurs in two molecular forms, those with and those without rearrangement of the breakpoint cluster region on chromosome 22. The molecular abnormality in the former group is similar to that found in chronic myelogenous leukemia. To characterize the abnormality in the breakpoint cluster region-unrearranged form, we have mapped a 9;22 translocation from the Philadelphia chromosome-positive acute lymphoblastic leukemia cell line SUP-B13 by using pulsed-field gel electrophoresis and have cloned the DNA at the translocation junctions. We demonstrate a BCR-ABL fusion gene on the Philadelphia chromosome. The breakpoint on chromosome 9 is within ABL between exons Ia and II, and the breakpoint on chromosome 22 is approximately equal to 50 kilobases upstream of a breakpoint cluster region in an intron of the BCR gene. This upstream BCR breakpoint leads to inclusion of fewer BCR sequences in the fusion gene, compared with the BCR-ABL fusion gene of chronic myelogenous leukemia. Consequently, the associated mRNA and protein are smaller. The exons from ABL are the same. Analysis of leukemic cells from four other patients with breakpoint cluster region-unrearranged Philadelphia chromosome-positive acute lymphoblastic leukemia revealed a rearrangement on chromosome 22 close to the breakpoint in SUP-B13 in only one patient. These data indicate that breakpoints do not cluster tightly in this region but are scattered, possibly in a large intron. Given the large size of BCR and the heterogeneity in breakpoint location, detection of BCR rearrangement by standard Southern blot analysis is difficult. Pulsed-field gel electrophoresis should allow detection at the DNA level in every patient and thus will permit clinical correlation of the breakpoint location with prognosis.

Chromosome Mapping↗
PubMed1988

Generation of a monoclonal antibody specific for Hb G-Philadelphia [alpha 2(68)(E17)Asn----Lys beta 2] and development of an immunoassay.

A murine hybridoma was generated which secreted a monoclonal antibody (Mab) that specifically recognized the alpha 2(68)(E17)Asn----Lys beta 2 substitution of Hb G-Philadelphia. Hybridomas were produced by fusion of RBF/DnJ immune splenic lymphocytes with FOX-NY murine myeloma cells and selected in adenine-aminopterin-thymidine (AAT) medium. Culture fluids were screened by ELISA for antibody reacting with Hb G-Philadelphia but not Hb A. One such culture was cloned by limiting dilution, expanded and injected into pristane-primed, cyclophosphamide-suppressed BALB/c mice for ascites production. An enzyme-linked immunoassay was developed by conjugating hemoglobin in hemolysates or purified hemoglobins to the plastic surface of wells of a microtiter plate. The ascites fluid containing the Hb G-Philadelphia Mab was added to the wells followed by goat anti-mouse IgG conjugated with horseradish peroxidase. After the addition of substrate (tetramethylbenzidine), a deep blue color developed, signifying a positive reaction. We analyzed 58 hemolysates (17 adult, 41 cord) containing a G-variant along with 28 control hemolysates (12 cords comprising FA, FAC, FAS, FSS, FCC phenotypes; 16 adults consisting of AA, AS, SS, SC, S-beta thal, AD-Los Angeles phenotypes). Of the 58 hemolysates containing a G-variant, 53 were positive by ELISA and confirmed by radioimmunoassay (RIA). Four of the five hemolysates negative for Hb G-Philadelphia were shown to be Hb G-Montgomery by RIA. None of the control hemolysates were positive. The assay could be completed in 1 hr and represents a technological advance in hemoglobin identification.

Animals↗
PubMed1989

Engulfment of the Philadelphia strain of Legionella pneumophila within pseudopod coils in human phagocytes. Comparison with other Legionella strains and species.

In this paper we report our ultrastructural studies of the early phagocytosis of two different strains of L. pneumophila serogroup (SG) 1 (Philadelphia 1 and Knoxville 1) and of L. micdadei. These bacteria replicate, in vivo as well as in vitro, in eukaryotic cells e.g. in monocytes and macrophages. Whether or not the mode of entry of these organisms in phagocytes contributes to their intracellular survival is presently unknown. Whilst internalization of bacteria of the Philadelphia 1 strain occurred within a pseudopod coil, organisms of the Knoxville 1 strain and L. micdadei were phagocytized in the classical manner, i.e. between pseudopods. No ultrastructural differences were observed between the two strains of L. pneumophila SG 1 whereas L. micdadei appeared as shorter rods with an extracellular layer of relatively low electron density. The phenomenon of coiling phagocytosis was not affected by heat-killing the bacteria or preopsonization with specific antibody. Formation of phagolysosomes was seen when cells of the Knoxville strain and L. micdadei were used but not with the Philadelphia strain. In our experiments, the occurrence of coiling phagocytosis was specific for the Philadelphia 1 strain of L. pneumophila and independent of bacterial virulence. Thus, it seems most unlikely that the coiling phenomenon plays any important role in the resistance of Legionella to the killing abilities of phagocytic cells.

Humans↗
PubMedDate not supplied

[Clinical, structural and functional studies of HbG Philadelphia detected in a Moroccan newborn].

Hb G Philadelphia (alpha68 Asn leads to Lys) is widely distributed in black people but is uncommon in North-Africa. Only one case has been previously described in an Arab immigrant. The latter and our propositus originated from North-East morocco. Hb G alpha Philadelphia is stable. The abnormal hemoglobin represented 28% of total hemoglobin in the hemolysate of the propositus, a 7 month old child. At birth, 4 fractions were detected on electrophoresis: Hb A, Hb F, Hb G Philadelphia, which migrated like Hb S, and a mutant alpha2Ggamma2. The oxygen affinity of Hb G Philadelphia was slightly elevated. Cooperativity and Bohr effect were normal. The abnormal hemoglobin was also detected in the father of the propositus in the heterozygote state: its clinical and hematological data were normal. No evidence of thalassemia trait was found in the family. The percentage of abnormal hemoglobin obtained in the propositus and his father is in accordance with the presence of two loci for the alpha chain on the homologous chromosome.

Electrophoresis, Cellulose Acetate↗
PubMed2026

Cytogenetic Diversity of Variant Philadelphia Translocations in Chronic Myeloid Leukemia.

INTRODUCTION: Chronic myeloid leukemia (CML) is a disease characterized by Philadelphia (Ph) translocations. These translocations can be classical or variant. The structural features and diagnostic implications of variant Philadelphia translocations remain incompletely defined, and they display considerable cytogenetic heterogeneity. METHODS: In this retrospective study, variant Ph translocations identified by conventional cytogenetic analysis and fluorescence in situ hybridization (FISH) were systematically classified among 639 patients diagnosed with CML. A total of 35 patients with variant Ph translocations were included in the analysis. Molecular follow-up data, when available, were assessed using RT-qPCR analyses in a subset of patients. RESULTS: Chromosome analysis revealed 2 simple and 33 complex variant Ph translocations. FISH analysis, performed in 20 patients, identified deletions involving BCR, ABL1, or both in a limited number of cases. Additional chromosomal abnormalities and secondary translocations accompanied variant Ph translocations in four patients. The partner chromosomes involved in variant Ph translocations showed marked diversity, involving multiple chromosomal loci. CONCLUSION: Variant Philadelphia chromosome translocations in CML exhibit substantial cytogenetic diversity, reflecting the complexity of their underlying genomic architecture. The rarity and heterogeneity of these rearrangements complicate their classification and interpretation in routine diagnostic practice. Descriptive reporting of variant Ph translocations may contribute to a better understanding of their diagnostic complexity and support more accurate cytogenetic interpretation in CML.

Humans↗
PubMed1990

Neutrophilic myelofibrosis presenting as Philadelphia chromosome negative BCR non-rearranged chronic myeloid leukemia.

Chronic myeloid leukemia consists of Philadelphia chromosome positive disease in 90% of cases, and a further 5%, although Philadelphia chromosome negative, exhibit bcr gene rearrangements consistent with the disease. The remaining 5% of cases have a heterogeneous clinical picture with a course unlike that of classical chronic myeloid leukemia, and may belong to different pathologic entities. We report five cases belonging to the latter group, initially identified as Philadelphia chromosome negative, bcr non-rearranged chronic myeloid leukemia, that developed progressive leucocytosis, absolute monocytosis, myelodysplasia, extramedullary hematopoiesis, and had evidence of myelofibrosis. These cases may represent a distinct clinical entity characterized by neutrophilic myelofibrosis, which can be identified prospectively by clinical and pathologic criteria. Standard therapy for treating chronic myeloid leukemia or idiopathic myelofibrosis may not be appropriate for this group.

Adult↗