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Biomedical subjects

J Inazawa

Publications and source records attributed to J Inazawa.

At least 235 records · Page 13Linked to original sources

The unbalanced 1;7 translocation in de novo myelodysplastic syndrome and its clinical implication.

In our chromosome study of 97 patients with myelodysplastic syndrome (MDS), six showed an unbalanced translocation between chromosomes 1 and 7 [-7, +der(1)t(1;7)(p11;p11)]. All of them had morphologic myelodysplasia in trilineage of bone marrow cells, and cytopenia was the major finding in the peripheral blood. All six patients had symptoms of infection at the time of diagnosis, and five showed immunologic abnormalities (polyclonal hypergammaglobulinemia in four and increased marrow plasma cells in three). None of the patients survived more than 11 months after the diagnosis; the median survival time was 4 months. Both of the two patients whose karyotypes were reexamined in the course of their disease showed karyotypic evolution accompanying the coincidental leukemic transformation. Six patients with MDS who had the same chromosome abnormality [t(1;7)] are described and their characteristic clinical features are presented.

Adolescent↗

Long arm deletion of chromosome 7 unrelated to original karyotype in recurrent t(8;21) acute myeloblastic leukemia.

We describe a chromosomal abnormality, 7q-, unrelated to the original karyotype in a patient with recurrent t(8;21) acute myeloblastic leukemia. The 7q-, del(7)(q22q34), was seen in otherwise karyotypically normal cells. Cyclophosphamide was administered for 5 months during the maintenance therapy. Our observations indicate that unrelated karyotypes, besides karyotypic evolution, may be implicated in tumor cell heterogeneity and may support the previous documentation of a possibly causal relationship between chemotherapy and development of 7q-. A larger study will be required to elucidate the biologic significance, if any, of the unrelated karyotypes.

Adult↗

Diverse responses to retinoid in morphological differentiation, tumorigenesis and N-myc expression in human neuroblastoma sublines.

We established the subline RT-BMV-C6 from the parent human neuroblastoma cell line RT-BM by a process that required repeated subculture of cells, which were prone to disaggregation. RT-BMV-C6 and the parent cloned line, RT-BM-1, had an identical marker chromosome, confirming that both lines were derived from a common progenitor. In the analysis of surface antigen expression, RT-BMV-C6 did not react with UJ-127-11, Leu7 or KP-NAC2 MAbs to which RT-BM-1 showed positive binding. The levels of both N-myc amplification and expression in RT-BMV-C6 were twice as high as the level obtained in RT-BM-1. Colony-forming efficiency in soft agar was 2.0 +/- 0.8% for RT-BMV-C6 and 3 times greater than that for RT-BM-1 (0.6 +/- 0.1%). When 100 x 10(6) cells of RT-BM-1 and RT-BMV-C6 were inoculated into nude mice, tumor incidence was significantly higher for RT-BMV-C6 (6/6; 100%) than for RT-BM-1 (0/6; 0%). Our data show that N-myc is closely related to tumorigenicity in NB. When RT-BM-1 and RT-BMV-C6 were co-cultured with a new synthetic retinoid, polyprenoic acid (E5166), and dibutyryl cyclic AMP, RT-BM-1 was induced to neuronal differentiation, defined by the formation of neuronal processes and expression of neurofilaments, whereas RT-BMV-C6 was not. However, when exposed to E5166, N-myc expression of RT-BMV-C6 was more strongly reduced than that of RT-BM-1, and colony formation of RT-BMV-C6 was significantly inhibited as compared to RT-BM-1. These findings suggest that the reduction of N-myc expression might closely correlate with growth inhibition accompanying neuronal differentiation of neuroblastoma cells.

Animals↗

Distribution of breakpoint within the breakpoint cluster region (bcr) in chronic myelogenous leukemia with a complex Philadelphia chromosome translocation.

We analyzed, by Southern blot hybridization, the site of breakpoint within the breakpoint cluster region (bcr) in six patients with a complex Philadelphia chromosome (Ph) translocation and in 23 unselected patients with a standard Ph. The breakpoint was found within the 5.8 kb bcr in all 29 patients. When the bcr was subdivided into four parts, fragments I-IV, based on the restriction enzyme sites, among the six patients with a complex Ph, two had a breakpoint at fragment I, three at fragment II, and one at fragment III. This distribution of breakpoints in patients with a complex Ph did not differ significantly from that in patients with a standard Ph. A deletion of an allele within the bcr was found in three patients (50%) with a complex Ph and in three (13%) with a standard Ph. The internal bcr deletion may be more common in patients with a complex Ph.

Alleles↗

Rejoining between 9q+ and Philadelphia chromosomes results in normal-looking chromosomes 9 and 22 in Ph1-negative chronic myelocytic leukemia.

Rearrangement of the breakpoint cluster region (bcr) and the chromosomal location of c-abl and 3'-bcr were studied in two patients with Philadelphia chromosome (Ph1)-negative chronic myelocytic leukemia (CML). One patient (patient 1) had a normal karyotype and the other (patient 2), 46,XY,inv(3)(q21q26). Both patients showed the bcr rearrangement by Southern blot analysis with a 1.2kb 3'-bcr probe. In situ hybridization studies demonstrated the location of the homologous sequences of bcr on chromosome 22 in patient 1, and on chromosomes 9 and 22 in patient 2. These findings indicate that the morphologically normal-looking chromosomes 9 and 22 in patient 2 are the result of a retranslocation between chromosomes 9q+ and 22q-, abnormalities which were first formed by a standard Ph1 translocation.

Adult↗

A case of incomplete DiGeorge syndrome associated with partial monosomy 22q11.1 due to maternal 14;22 translocation.

We report a boy with some clinical symptoms compatible with a diagnosis of incomplete DiGeorge syndrome. He had a dismorphic face, micrognathia, cleft palate, and heart anomalies similar to DiGeorge syndrome, but lacked aplasia of the thymus or hypoparathyroidism typical of the syndrome. High-resolution banding analysis revealed that his karyotype was 45,XY,-14,-22, +der(14)(14pter----14q32.32::22q11.21----22qter), the consequence of a maternal reciprocal translocation between chromosomes 14 and 22. Precise localization of the gene responsible for the present DiGeorge syndrome was assigned to subband 22q11.1.

Adult↗

Simultaneous existence of double minute chromosomes and a homogeneously staining region in a retinoblastoma cell line (Y79) and amplification of N-myc at HSR.

We observed double minute chromosomes (dmin) and a homogeneously staining region (HSR) in the same metaphase cells obtained from a retinoblastoma cell line, Y79. All of the 132 metaphases examined contained an HSR on the short arm of chromosome 1(1pHSR) and five cells (3.8%) had two to four dmin. To determine whether 1pHSR and dmin carried amplified N-myc sequences, we performed an in situ hybridization using an N-myc probe. Silver grains clustered on and along the 1pHSR, but not on the dmin. These findings indicate that the HSR on chromosome 1 is associated with amplification of N-myc in Y79 cells.

Chromosome Aberrations↗

Regional assignment of nonspecific cross-reacting antigen (NCA) of the CEA gene family to chromosome 19 at band q13.2.

Nonspecific cross-reacting antigen (NCA) is a member of the carcinoembryonic antigen (CEA) gene family. Recently, a DNA segment for part of the human NCA gene was isolated and sequenced. We mapped this gene by Southern blot analysis of hybrid cells and by in situ hybridization. The Southern blot analysis indicated that the NCA gene is on human chromosome 19 and the in situ hybridizations localized the gene to band 19q13.2.

Animals↗

Clinical and cytogenetic features in six patients with chronic myelogenous leukemia and a complex Philadelphia translocation.

Six patients with chronic myelogenous leukemia and a complex Philadelphia (Ph1) translocation are described. The complex Ph1 translocations were a three-way translocation in five patients and a five-way translocation in one. Additional chromosomal aberrations were detected in four of five patients when the blastic crisis supervened. The median survival time was 42 months. The remaining patient died of acute myocardial infarction 23.5 months after the diagnosis of CML was made. There seems no difference between these six patients and those with the standard Ph1 with respect to clinical, hematologic and cytogenetic findings.

Adolescent↗

[Relation of karyotypic findings to chemotherapy response in patients with preleukemia].

In 1982, the French-American-British (FAB) Cooperative Group proposed the myelodysplastic syndrome (MDS), which comprised a group of heterogeneous hematologic disorders characterized by various degrees of cytopenias and a possibility of leukemic transformation. And chromosome findings of bone marrow cells from patients with this syndrome are reported to have one of the greatest prognostic significance. In our chromosome study of 97 patients with MDS, we found clonally abnormal karyotypes in 61 patients (63%), including the whole chromosome or partial loss of long arm of chromosome 7 (-7/7q-) in 18 patients and a partial loss of chromosome 5 (5q-) in 14 patients. Among these 97 patients, 26 received cytostatic chemotherapy (small dose of cytarabine; 23 patients, small dose of behenoyl Ara-C; 2, and intensive combined chemotherapy; 1) as well as supportive care. Among these 26 treated cases, pretreatment hematological characteristics or FAB subclassifications were not associated with response to chemotherapy. In contrast, only one of 9 patients with -7/7q- and/or 5q- achieved a partial remission, while 5 of 8 patients with other abnormal karyotypes and 4 of 9 patients with normal karyotype achieved a complete (4 patients) or a partial remission. In conclusion, pretreatment cytogenetic findings can predict the potential responders to this chemotherapy, and may be one of the most important factors in the selection of the treatment for this ill-managed syndrome.

Adult↗

[Clinical evaluation of a combination therapy with aztreonam and clindamycin for severe infections in leukemia and related disorders].

A combination of aztreonam (AZT) and clindamycin (CLDM) was evaluated for severe infections associated with leukemia and related disorders. AZT is a monobactam antibiotic which has strong bactericidal effect against Gram-negative bacteria including Pseudomonas aeruginosa. CLDM which has strong antibacterial spectrum against Gram-positive and anaerobic bacteria, was chosen as a partner of AZT in order to complement the weak points of AZT. Fifty six patients were treated with the combination therapy. Among them, 51 patients were evaluable for the effectiveness. Five patients were excluded from the evaluation because 3 patients were subjected to additional therapy with other agents such as amikacin, miconazole and pulse therapy of a large dose of methylprednisolone, one had a fever episode apparently due to primary disease, and the remaining one was discontinued of the combination therapy of administration due to mild nausea after 3 days. Excellent responses were obtained in 17 (33.3%) patients and good responses in 20 (39.2%) patients, with a total rate of effectiveness of 72.5%. One patient with whom the combination therapy was stopped due to nausea, was included in the final evaluation of side effects. Side effects were observed in 2 patients of 50 and 40 years of ages (2/52, 3.8%), both of whom suffered with nausea. In the 50 years patient of acute myeloblastic leukemia, nausea occurred in a slight degree in 3 hours after the combined regimen was started. But, it disappeared during the continuation of the combination therapy. In the 40 years patient of acute myelomonocytic leukemia, mild nausea occurred after 3 day administration of the combined regimen. It disappeared soon after the cessation of the treatment. These results indicated that a combination of AZT and CLDM was an effective and safe regimen for the treatment of severe infections in patients with hematological disorders.

Adult↗