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Biomedical subjects

D Catovsky

Publications and source records attributed to D Catovsky.

At least 55 records · Page 3Linked to original sources
PubMed2000

Interleukin-6 and other gp130-dependent cytokines selectively inhibit proliferation of macrophage-lineage hemopoietic progenitor cells.

OBJECTIVE: Hemopoiesis is regulated by cytokines with positive or negative effects on proliferation of lineage-committed or multipotent hemopoietic stem cells. We have investigated the roles of interleukin-6 and other gp130-dependent ligands on the proliferation of macrophage-lineage hemopoietic progenitor cells. METHODS: The responses of human and murine hemopoietic cells to combinations of cytokines involving interleukin-6 or related factors were assessed in short-term culture by clonogenic assay. RESULTS: Interleukin-6, leukemia inhibitory factor, and ciliary neurotrophic factor inhibited formation of colonies stimulated by macrophage colony-stimulating factor. These effects were dose dependent and selective for macrophage-lineage precursors. Progenitors from murine peripheral blood were inhibited by 37-93% in cultures containing interleukin-6 (11 experiments; median, 68%). Macrophage progenitors from murine bone marrow were also inhibited by interleukin-6 but were less sensitive (seven experiments; median, 48%). In cultures costimulated with leukemia inhibitory factor, peripheral blood and bone marrow progenitors were inhibited by 82% and 58%, respectively. Ciliary neurotrophic factor inhibited macrophage colonies by 66%. Multilineage bone marrow colony formation was not affected. In cultures of human bone marrow cells stimulated with macrophage colony stimulating factor and stem cell factor, interleukin-6 inhibited colony formation by 51-74%. Bone marrow colonies stimulated by granulocyte-macrophage colony stimulating factor were not inhibited by costimulation with interleukin-6. CONCLUSIONS: These results suggest a novel mechanism for the negative regulation of macrophage-lineage hemopoietic cells. They also demonstrate new properties of interleukin-6 and certain other gp 130-dependent ligands.

Animals↗
PubMed2000

Frequent deletions at 11q23 and 13q14 in B cell prolymphocytic leukemia (B-PLL).

Deletions of the long arm of chromosomes 11 and 13 are the most frequent structural chromosome aberrations in various types of lymphoproliferative disorders. However, these regions have not been studied so far in B cell prolymphocytic leukemia (B-PLL). We have investigated the incidence of 13q deletions in 18 B-PLL cases by fluorescence in situ hybridization (FISH), using molecular probes for the RB1 and D13S25 loci. Chromosome 11q deletions were evaluated by FISH using the yeast artificial chromosome (YAC) clone 755b11 from the chromosome 11q22.3-q23.1 region, which has been previously shown to be deleted in 20% of cases of chronic lymphocytic leukemia. Chromosome 11q23 deletions were found in 7/18 (39%) cases of B-PLL. Monoallelic loss of RB1, D13S25 and BRCA2 was present in 10/18 (55%), 6/18 (33%) and 3/18 (16%) of the cases, respectively. All the cases with D13S25 and BRCA2 deletion showed RB1 loss. Deletions of 13q14 and 11q23 are frequent chromosome aberrations in B-PLL and, in contrast to CLL, there is a preferential loss of RB1 with respect to the D13S25 locus suggesting that allelic loss of the RB1 gene may play a role in the pathogenesis of B-PLL.

Adult↗
PubMed2000

Familial chronic lymphocytic leukaemia: a survey and review of published studies.

B-cell chronic lymphocytic leukaemia (CLL) is the most common form of leukaemia. To gain insight into the role of inherited factors in the disease, we have conducted a survey of the family histories of 268 CLL patients and have reviewed published familial cases and epidemiological studies. The results of our survey and published studies strongly support the hypothesis that a subset of the disease can be ascribed to a genetic predisposition. The most likely genetic model for inherited predisposition appears to be dominantly acting genes with pleiotropic effects because in many families CLL appears to be associated with other lymphoproliferative disorders.

Adult↗
PubMed2000

p53 allele deletion and protein accumulation occurs in the absence of p53 gene mutation in T-prolymphocytic leukaemia and Sezary syndrome.

In a series of 24 patients with chronic T-lymphoid disorders [13 T-prolymphocytic leukaemia (T-PLL) and 11 Sezary syndrome] we have studied (i) chromosome 17p abnormalities and p53 allele deletion by fluorescence in situ hybridization; (ii) mutation in the exons of the p53 gene by direct DNA sequencing; and (iii) p53 protein expression by immunocytochemistry and, in some cases, also by flow cytometry with DO-1, a monoclonal antibody to the p53 protein. The study revealed p53 deletion and accumulation of p53 protein in the absence of mutation in the exons that included the hot-spots and differs from that described in B-prolymphocytic leukaemia. Seven T-PLL and five Sezary syndrome patients had p53 overexpression, and five T-PLL and nine Sezary syndrome patients showed p53 deletion. Although the majority of cases with p53 accumulation had p53 deletion, the proportion of cells with the deletion did not correlate with the proportion of cells positive for p53 expression. Two cases of T-PLL showed strong p53 expression in the absence of p53 deletion, and one case of Sezary syndrome with p53 deletion in 97% of cells did not express p53. These findings suggest that a non-mutational mechanism exists for the accumulation of p53 protein in these T-cell disorders. The oncogenic effect of the accumulating wild-type protein has been reported in other malignancies. Whether haploidy resulting from p53 deletion contributes to this mechanism has yet to be determined. Alternatively, the frequent loss of the p53 gene could be associated with the deletion of an adjacent gene, which could be involved in the pathogenesis of these diseases.

Adult↗
PubMed2000

T-cell prolymphocytic leukaemia: antigen receptor gene rearrangement and a novel mode of MTCP1 B1 activation.

T-cell prolymphocytic leukaemia (T-PLL) is a sporadic, mature T-cell disorder in which there is usually an aberrant T-cell receptor alpha (TCRA) rearrangement that activates the TCL1 or MTCP1-B1 oncogenes. As mutations of the Ataxia Telangiectasia (A-T) gene, ATM, are frequent in T-PLL and as ATM seems to act as a tumour suppressor through a mechanism involving V(D)J recombination, we examined V(D)J recombination in T-PLL. Using Southern blotting and the polymerase chain reaction, two of 60 TCRG coding joints were abnormal. In all cases, both TCRD alleles were deleted, IGH was germline, and patterns of TCRB and TCRA rearrangement were normal. However, in a case harbouring t(X;7)(q28;q35), we identified TCRB segment J beta 2.7 juxtaposed to MTCP1 exon 1. This is the first time that TCRB has been implicated in MTCP1 B1 activation. The structure of the breakpoint supports a model in which translocation activates a cryptic MTCP1 promoter. This analysis of V(D)J recombination is consistent with it being a variable that is independent of ATM in T-PLL.

Alleles↗
PubMed2000

Disease features in acute myeloid leukemia with t(8;21)(q22;q22). Influence of age, secondary karyotype abnormalities, CD19 status, and extramedullary leukemia on survival.

Over a period of 14 years, 50 patients (12 children and 38 adults) of whom 46 had acute myeloid leukemia (AML) and 4 had myelodysplastic syndrome characterized by the t(8;21)(q22;q22) translocation were referred to the Royal Marsden Hospital. The clinicopathological features of these cases were analyzed to determine the influence of age, secondary karyotype abnormalities, and expression of the lymphoid marker CD19 on event free survival, and presence of extramedullary leukemia on overall survival. They were treated with a variety of chemotherapy protocols and some had bone marrow transplantation. There appeared to be no difference in survival between children (age <17 years) and adults (age >16 years). Out of the 50 cases, 16 (32%) had the (8;21) translocation alone, 17 (34%) had additional loss of a sex chromosome and the remaining 17 (34%) had other karyotype abnormalities of which deletion or translocation of the long arms of a #9 was most common (observed in 8 of the 17 patients). The karyotype groups had a significant impact on survival, the group with loss of a sex chromosome having a poorer outcome and the group with abnormalities of chromosome 9 having a better outcome. CD19 positivity was seen in 21 of the 33 cases (63%) in whom it was measured compared to 11% observed in controls with AML without a t(8;21). CD19 status did not exert any influence on event free survival. Extramedullary leukemia (EML) occurred in 5 of the 50 cases (10%). In one patient it was observed at diagnosis but in the others it presented concurrent with bone marrow relapse. The overall survival of patients with EML was worse than that of the other patients but did not achieve statistical significance and was probably adversely affected by other factors.

Acute Disease↗
PubMed2000

Follicular lymphoma. A series of 11 patients with minimal or no treatment and long survival.

Follicular lymphoma is the commonest low-grade lymphoma. Its indolent nature even in advanced stages and the failure of conservative or aggressive treatments to achieve a cure have questioned the need for immediate treatment. Eleven patients with follicular lymphoma who had minimal or no treatment were retrospectively reviewed. Median age was 44 years. Staging was: I (4), III (6) and IV (1). Eight were confirmed to have follicular lymphoma of whom six did not receive treatment at presentation. Four of these patients remain in remission after 14 to 30 years of follow-up and the other two have relapsed after 10 and 13 years of follow-up, respectively. Two patients who were treated at diagnosis remained disease free for 18 years. Three patients had diffuse large cell lymphoma on review. They received no treatment, radiotherapy or chemotherapy and have been in remission for 36, 14 and 23 years respectively. The overall survival is 58% at 30 years, and median survival has not been reached for the whole group. Observation seems to be a valid alternative to treatment in patients with stages I to III until signs of progression.

Adult↗
PubMed2000

Clinical overview of pentostatin (Nipent) use in lymphoid malignancies.

We summarize the results of our experience over the past 15 years using pentostatin (Nipent; SuperGen, San Ramon, CA) to treat a range of mature B- and T-cell malignancies. This includes 145 patients with postthymic T-cell malignancies in whom disease subtype was found to be the most significant predictor of response, with the best response rates seen in Sézary syndrome (62%) and T-prolymphocytic leukemia (45%). However, there are no long-term survivors among patients with this group of disorders, and strategies using pentostatin in combination with other therapies, such as CAMPATH-1H, are currently being explored. Among the mature B-cell diseases, pentostatin in both standard- and low-dose regimens is effective in advanced, relapsed/refractory B-chronic lymphocytic leukaemia, showing no cross-resistance with other purine analogs such as fludarabine. Our largest series treated with pentostatin consists of 165 patients with hairy cell leukemia. The follow-up period in this group extends to more than 10 years, with a projected event-free survival rate at 5 years of 60% and an overall survival rate of 97%.

Antibiotics, Antineoplastic↗
PubMed2000

Pentostatin treatment of cutaneous T-cell lymphoma.

Mycosis fungoides is an indolent primary cutaneous T-cell lymphoma (CTCL) that usually progresses from localized skin lesions to systemic disease. Sézary syndrome is a distinct variant characterized by generalized erythroderma and circulating cerebriform cells in the peripheral blood. The malignant cell in both diseases is a mature T cell, usually with a CD4-positive, CD8-negative phenotype. Among the treatment modalities used in these diseases are skin-directed therapy, single-agent and combination systemic chemotherapy, and, more recently, bioimmunotherapy. Pentostatin (Nipent), a potent inhibitor of adenosine deaminase, has activity in a wide range of lymphoid malignancies. At The Royal Marsden Hospital, we treated 29 cutaneous T-cell lymphoma patients with pentostatin, including 16 with Sézary syndrome, 5 with mycosis fungoides, and 8 with other cutaneous T-cell lymphomas. The median age of patients was 61 years (range, 26 to 87 years), with a male-female ratio of 2.5:1. The majority (N = 20) had received prior therapy. Pentostatin was administered at a dose of 4 mg/m2/wk for 4 weeks, and injections were continued every 1 to 2 weeks until maximum response. The overall response rate was 35%. However, only patients with Sézary syndrome achieved a good response, demonstrating an overall response rate of 62% (three complete responses plus seven partial responses). The median disease-free interval for responders was 9 months (range, 3 to 84 months). There was no significant treatment-related toxicity. We conclude that pentostatin is an effective single-agent therapy for patients with Sézary syndrome but not for those with other cutaneous T-cell lymphomas.

Adult↗
PubMed2000

Quantitative expression of CD23 and its ligand CD21 in chronic lymphocytic leukemia.

BACKGROUND AND OBJECTIVES: Cells from the great majority of patients with chronic lymphocytic leukemia (CLL) express CD23. A recent histologic study has shown that CD23 is expressed more strongly in the proliferating centers of the lymph nodes, where the large prolymphocytoid cells are located. The aim of our study was to quantify the expression of CD23 and CD21 in small and prolymphocytoid cells from patients with CLL and B-cell lymphomas, and correlate this expression with clinical parameters. DESIGN AND METHODS: Using quantitative flow cyto-metry we analyzed the antigen density of CD23 and CD21 in: 1) 101 cases of chronic lymphocytic leukemia, 84 typical, 14 with increased prolymphocytes (CLL/PL) and 3 atypical, 2) 15 cases of CD23 positive B-cell lymphoma with circulating lymphoma cells and 3) 8 normal subjects. The results were correlated with morphology and clinical staging. RESULTS: Cells from CLL and CLL/PL have a significantly higher number of CD23 molecules than normal and lymphoma B-cells (p<0.001 and p<0.001, respectively). Differences were not significant for CD21. CLL and CLL/PL cases had similar values of CD23 and CD21 molecules, but analysis at a single level showed that prolymphocytes in typical CLL and CLL/PL expressed significantly higher CD23 (p=0.001, p=0.006) and CD21 (p=0.001, p=0.001) than small lymphocytes. There was no correlation between CD23 or CD21 antigen density and clinical stages although there was a trend for a brighter CD23 in stage C patients. INTERPRETATION AND CONCLUSIONS: Since interaction between CD23 and CD21 is important for B-cell activation, proliferation and tumor formation, findings that both molecules are upregulated in prolymphocytes suggest that this is the proliferating cell component in CLL and underline the association between progression and increased prolymphocytes in typical CLL and CLL/PL.

Bone Marrow Cells↗
PubMed1999

Myeloid- and lymphoid-specific breakpoint cluster regions in chromosome band 13q14 in acute leukemia.

Abnormalities of chromosome band 13q14 occur in hematologic malignancies of all lineages and at all stages of differentiation. Unlike other chromosomal translocations, which are usually specific for a given lineage, the chromosomal translocation t(12;13)(p12;q14) has been observed in both B-cell and T-cell precursor acute lymphoblastic leukemia (BCP-, TCP-ALL), in differentiated and undifferentiated acute myeloblastic leukemia (AML), and in chronic myeloid leukemia (CML) at progression to blast crisis. The nature of these translocations and their pathologic consequences remain unknown. To begin to define the gene(s) involved on chromosome 13, we have performed fluorescence in situ hybridization (FISH) using a panel of YACs from the region, on a series of 10 cases of acute leukemia with t(12;13)(p12;q14) and 1 case each with "variant" translocations including t(12;13)(q21;q14), t(10;13)(q24;q14) and t(9;13)(p21;q14). In 8/13 cases/cell lines, the 13q14 break fell within a single 1.4 Mb CEPH MegaYAC. This YAC fell immediately telomeric of the forkhead (FKHR) gene, which is disrupted in the t(2;13)(q35;q14) seen in pediatric alveolar rhabdomyosarcoma. Seven of the 8 cases with breaks in this YAC were AML. In 4/13 cases, the 13q14 break fell within a 1.7-Mb YAC located about 3 Mb telomeric of the retinoblastoma (RB1) gene: all 4 cases were ALL. One case of myelodysplastic syndrome exhibited a break within 13q12, adjacent to the BRCA2 gene. These data indicate the presence of myeloid- and lymphoid-specific breakpoint cluster regions within chromosome band 13q14 in acute leukemia.

Adult↗
PubMed1999

p53 gene deletion and trisomy 12 in hairy cell leukemia and its variant.

The deletion or mutation of the p53 tumour suppressor gene on chromosome 17p13 is known to be associated with aggressive disease in several B-cell malignancies. The present study describes the p53 gene status in 20 cases of hairy cell leukemia (HCL) and in 12 cases of its morphological variant (HCL-V) by fluorescence in situ hybridization (FISH). A high incidence of p53 deletion was found in both diseases (75-100% of cases). However, a significant difference was observed between the proportion of cells with p53 deletion in HCL-V cases (mean 31%) and HCL cases (mean 12%) P value < 0.01. The observed difference correlates with the well known tendency for transformation and poor response to therapy in HCL-V and seven cases of HCL-V with greater than 22% of cells with p53 deletion showed features of disease progression and transformation. Trisomy 12 was present in 8.5% of the cells in one case of HCL-V and in 6-8% of cells in three cases of HCL.

Alleles↗
PubMed1999

B cell prolymphocytic leukaemia (B-PLL) with complex karyotype and concurrent abnormalities of the p53 and c-MYC gene.

We report the cytogenetic, molecular and biological characterization of a case of B-PLL with a complex karyotype and concurrent abnormalities on the p53 and c-MYC genes. Conventional cytogenetics suggested that both 17q arms were translocated to chromosomes 1q and 14p, respectively, whereas both 17p arms were not identified. In addition, a Burkitt's-like variant translocation t(2;8) was found. Study of loss of heterozygosity at 17p13 and p53 direct sequencing demonstrated the presence of only one copy of the p53 gene. A 27 bp deletion in exon 8 that resulted in the expression of a p53 protein lacking nine amino acids from the DNA binding region was also found. To confirm the presence of one copy of the p53 gene and localize it, fluorescent in situ hybridization (FISH) studies using a p53 gene probe was performed. Only one signal of p53 was visualized. Moreover, the DAPI profile of the chromosome containing the hybridization spot for the p53 probe did correspond to the cytogenetic marker identified as der(14)t(14;17). Whole chromosome 14 paint, centromere-specific for chromosome 17 and p53 gene probes were cohybridized to the preparations. This demonstrated that the der(14) contained the 17 centromere and distally the p53 gene suggesting that the der(14) contained the short arm of chromosome 17 with the breakpoint occurring in the long arm. FISH studies confirmed the involvement of c-MYC and KAPPA in the t(2;8) translocation. To our knowledge, this is the first case of B-PLL with inactivation of the p53 gene by mutation together with a Burkitt's-like t(2;8) translocation involving the c-MYC gene. The cooperation of these genes may have conferred a growth advantage which was critical in the development of this aggressive form of B-PLL.

Aged↗
PubMed1999

Linkage analysis for ATM in familial B cell chronic lymphocytic leukaemia.

B cell chronic lymphocytic leukaemia (CLL) shows evidence of familial aggregation, but the inherited basis is poorly understood. Mutations in the ATM gene have been demonstrated in CLL. This, coupled with a possibly increased risk of leukaemia in relatives of patients with Ataxia Telangiectasia, led us to question whether the ATM gene is involved in familial cases of CLL. To examine this proposition we typed five markers on chromosome 11q in 24 CLL families. No evidence for linkage between CLL and ATM in the 24 families studied and the best estimates of the proportion of sibling pairs that share no, one or both haplotypes at ATM were not different from their null expectations. This would imply that ATM is unlikely to make a significant contribution to the three-fold increase in risk of CLL seen in relatives of patients.

Adult↗
PubMed1999

FISH analysis for BCL-1 rearrangements and trisomy 12 helps the diagnosis of atypical B cell leukaemias.

We have investigated the diagnostic value of fluorescence in situ hybridisation (FISH) to detect t(11;14) and trisomy 12 in 53 cases with a B cell leukaemia difficult to classify on clinical and laboratory grounds. These cases were initially diagnosed by morphology and immunophenotype and in 33 of them, on tissue histology, as follows: chronic lymphocytic leukaemia (CLL), 20, 18 of them with atypical features; B cell prolymphocytic leukaemia (B-PLL), two; mantle-cell lymphoma (MCL), 15; splenic lymphoma with villous lymphocytes (SLVL), five; lymphoplasmacytic lymphoma, six; follicular lymphoma, one and, four cases remained unclassifiable. FISH demonstrated BCL-1 rearrangement in the circulating cells from 15 cases classified as: MCL (10), atypical CLL (three) and B-PLL (two). A definitive diagnosis of MCL was made on review of the spleen histology in one out of the three atypical CLL with BCL-1 rearrangement. Trisomy 12 was detected in eight cases which included four atypical CLL, one typical CLL, two MCL and one unspecified B cell lymphoma by histology and morphology. One of the MCL had both trisomy 12 and BCL-1 rearrangement and the other was CD5+, CD23+ and had a CLL score of 3, suggesting the latter diagnosis. Our findings demonstrate that FISH analysis is useful to clarify the nature of the disease in patients presenting with a B cell leukaemia in which the diagnosis is difficult by conventional methods. FISH established with certainty the diagnosis of MCL by showing BCL-1 rearrangement in over two-thirds of cases in which this was suspected, including blastoid forms, and confirmed the diagnosis of most cases of atypical CLL.

Chromosomes, Human, Pair 12↗