Shoichiro Tsuda

Detection of karyotypic abnormalities in most patients with acute nonlymphocytic leukemia by adding ethidium bromide to short-term cultures

A modified short-term culture method, in which cultured bone marrow cells were treated with ethidium bromide to prevent chromosome condensation was used to study the chromosomes of 70 patients with acute nonlymphocytic leukemia. Clonal karyotypic abnormalities were detected in 60 patients. Among these, 35 patients showed one of recurrent type specific alterations. A close relationship between karyotypes and clinical outcome was shown: thus, t(8;21) or a single miscellaneous chromosomal defect associated with a favourable prognosis whereas t(9;11) or a complex karyotype related to a poor prognosis. The ten cytogenetically normal patients did not appear to have a favourable prognosis.

Reciprocal t(14;19)(q32.3;q13.1) in a patient with B-cell lymphoma

A patient with B-cell lymphoma with a chromosome rearrangement of t(14;19)(q32.3;q13.1) is reported. This patient had leukemic features and an aggressive clinical course. The histopathologic diagnosis was malignant lymphoma, small noncleaved cell. Chromosome analysis of the cells from a cervical lymph node and peripheral blood showed a reciprocal translocation between chromosome 14 with a break at band q32.3 and chromosome 19 with a break at band q13.1, to which the bcl-3 gene has been mapped. Monoclonal rearrangement of the JH gene was detected by Southern blot analysis. However, we could not detect rearrangement of the bcl-3 gene. This case also had a t(2;8)(q13;q24.1), but the c-myc gene remained in its germline. This is the first case with the reciprocal t(14;19) and 8q24 chromosomal breakpoint in a B-cell lymphoid malignancy.

cis-diamminedichloroplatinum(II)-induced sister-chromatid exchanges and chromosome aberration formation in cultured human lymphocytes and their inhibition by sodium thiosulfate.

cis-Diamminedichloroplatinum(II) (cis-DDP)-induced sister-chromatid exchanges (SCEs) and chromosome aberration formation were studied in human lymphocytes. The mitotic index decreased abruptly at 2 X 10(-6) M cis-DDP and the frequency of SCEs was dose-related; a marked increase was recorded at 10(-6) M cis-DDP. A dose-dependent effect was also found for chromosome aberration formation at concentrations between 10(-11) and 4 X 10(-6) M. The aberrations observed were primarily chromatid breaks and gaps. We also examined the inhibition of these genotoxicities by treating the cells with sodium thiosulfate (STS). Simultaneous treatment with 10(-4)-10(-3) M STS (100-1000-fold molar ratio to cis-DDP) significantly reduced the frequency of SCEs induced by 10(-6) M cis-DDP. Furthermore, a 3-h delay in treating with STS significantly reduced cis-DDP-induced SCEs, but not chromosome aberration formation.

Myelodysplastic Syndrome Preceding Acute Myelomonocytic Leukemia with Dysplastic Marrow Eosinophilia and Inv(16)

A 44-year-old Japanese male having refractory anemia with excess of blasts (RAEB) preceding acute myelomonocytic leukemia (AMMoL) with dysplastic marrow eosinophilia (M4Eo in the FAB classification) is reported. Sequential cytogenetic studies revealed a specific chromosomal abnormality, inv(16) (p13q22), when RAEB was first diagnosed and again when overt leukemic transformation compatible with M4Eo was manifested. However, during the interval between the RAEB and AMMoL, an unrelated abnormal karyotype without inv(16), 47,XY,+9, was seen, when hematological data revealed remission after a low dose of cytosine arabinoside was administered. In this patient eosinophils in the marrow were involved in the leukemic process cytogenetically, because a few metaphases overlaid with eosinophilic granules had the inv(16) with other numerical abnormalities.

Chromosome Abnormalities of Gastric Cancer Detected in Cancerous Effusions

The chromosomes were examined in cancerous effusions obtained from 7 patients with gastric cancer. In 1 patient, the modal chromosome number was 46 with a normal chromosome complement in the majority of the cells examined. The other 6 patients revealed numerical and structural aberrations. Among the structural rearrangements detected, chromosome 3 was involved in the short arm and in the long arm, each in three patients; bands p25, q21, q23, and q27 were recurrently involved and a band q23 was lost in 3 patients. Rearrangements of chromosome 5 in the long arm and of chromosome 17 at or near the centromere were also observed in three patients each. Gains of chromosome 7 was seen in 5 patients and of chromosome 13 in 4. Some of these alterations may be specific for gastric cancer.

Induction of sister-chromatid exchanges by N-nitrosocimetidine in cultured human lymphocytes and its inhibition by chemical compounds

The effect of nitrosocimetidine (NC) on the frequency of sister-chromatid exchanges (SCEs) in human lymphocytes has been studied. The frequency of SCEs induced by a 1-h exposure to 2.6 X 10(-4) M NC was 4-fold greater than that in the solvent control. A 72-h exposure to NC had a similar dose-related effect. We also examined the effect of the sulfhydryl compounds cysteine, cysteamine, cystamine and glutathione, the reducing agent dithionite, and vitamins C and E on the NC-induced SCEs. None of these compounds induced SCEs. Cysteine, cysteamine, and cystamine significantly reduced the number of NC-induced SCEs, and the others did not.

DNA analysis using long-term preserved fixed cytogenetic preparations

SummaryDNA was isolated from cell pellets that had been stored in methanol-acetic acid (3 : 1) at −20°C up to 6 years. These cell pellets contained high molecular weight DNA sufficient for Southern blot hybridization. The method enables us to study the DNA of a patient after completing chromosome analysis or in cases where DNA samples are otherwise not available.

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.

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

SummaryWe 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.

Multiple Cranial Neuritis Associated with Large Granular Lymphocytosis

A patient with a unique form of large granular lymphocytosis and multiple cranial neuritis is reported. The patient presented with facial weakness, diplopia and dysarthria. An increase in large granular lymphocytes (LGLs) was seen in blood (1.8 x 10(9)/l), CSF (237/microliters) and bone marrow (20% in a normocellular bone marrow). The phenotype of the LGLs in CSF, blood and bone marrow was CD2+ CD3+ CD4+ CD8- CD16- CD56- and CD57-. The unique features of this case include the CD4+ phenotype, the relative abundance of CSF LGL and the clinical presentation.