A nodal gamma/delta T-cell lymphoma with an association of Epstein-Barr virus

The postthymic gamma/delta T-cell lymphoma is rare, and most occur as extranodal tumors, e.g., in hepatosplenic or cutaneous forms. We here report an unusual nodal case that initially presented as a T-zone lymphoma. The neoplasm recurred as systemic lymphadenopathy 25 months after complete remission with terminal high-grade transformation. Phenotypic analysis showed CD1-, CD2+, CD3+, CD4-, CD5-, CD7+, CD8+, CD10-, CD16-, CD19-, CD20-, CD21-, CD25-, CD56-, CD57-, T-cell receptor (TCR) alpha/beta antigens negative, TCR gamma/delta antigens positive, and an HLA-DR+ phenotype. Cytogenetic studies showed clonal chromosomal translocations involving chromosomes 1, 5, 6, 8, 15, and X in eight of 15 cells; t(X;5;1)(q13;q13;p22) and t(6;15;8)(p22;q26;q13). Genotypic analysis showed the same clone, characterized by the TCR gamma-chain gene rearrangement pattern, to be present in both initial and recurrent tumors. The lymphoma cells were also demonstrated to express the latent membrane protein-1 by immunohistochemistry and EBV-encoded small RNAs by in situ hybridization. Southern blot analysis using the probe of the terminal repeat demonstrated incorporation of multiple copies of EBV in the recurrent tumor. However, the initial lesion, which contained a smaller number of EBV-positive cells, showed no such evidence of clonal proliferation. These data suggest that EBV may be associated with high-grade transformation, although its exact role in lymphomagenesis remains uncertain. The present study also adds to our understanding of the clinicopathologic spectrum of gamma/delta T-cell neoplasia.

Tandem duplication of the MLL gene in myelodysplastic syndrome-derived overt leukemia with trisomy 11

Trisomy 11 as a sole chromosomal abnormality is a rare aberration observed in myelodysplastic syndrome (MDS) or acute myeloblastic leukemia (AML). Recently a partial tandem duplication of the MLL gene, located on chromosome band 11q23, has been identified in de novo AML with trisomy 11. We describe a 72-year-old woman suffering from MDS-derived overt leukemia with trisomy 11 and a tandem duplication of the MLL gene. At first the patient was found to have myeloblasts with Auer rods in the peripheral blood and diagnosed as MDS, refractory anemia with excess of blasts in transformation (RAEB-T). After 2 months a picture of overt leukemia (AML; M2) developed as shown by an increased number of myeloblasts. Various chemotherapy regimens had little effect, and she died of disease progression 15 months after admission. During her clinical course, the chromosome analyses consistently showed 47,XX, +11. Southern blot analysis of leukemic blasts on admission and in accelerated phase revealed identical rearranged bands of the MLL gene. Fluorescence in situ hybridization analysis excluded the possibility of masked translocation of the MLL gene to other chromosomes. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis using a forward exon 6 primer and a backward exon 3 primer demonstrated an in-frame fusion of exon 8 with exon 2. Our results indicated that a partial tandem duplication of exons 2-8 of the MLL gene could be observed in MDS-derived overt leukemia as well as de novo AML with trisomy 11.

Establishment of a novel human acute myeloblastic leukemia cell line (YNH-1) with t(16;21), t(1;16) and 12q13 translocations

The t(16;21)(p11;q22) translocation is a non-random chromosomal aberration observed in several types of human acute myeloblastic leukemia (AML), whereas the der(16)t(1;16) and chromosome rearrangements at 12q13 are frequently found in solid tumors. A novel cell line YNH-1 was established from peripheral blood cells of a 46-year-old male with AML (M1) carrying t(16;21) and t(1;16) translocations. YNH-1 has been maintained with a doubling time of 82 h for more than 20 months as a granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-3 (IL-3) dependent line. Morphologically YNH-1 cells were free-floating immature myeloblasts with lobulated nuclei and vacuoles in the cytoplasm. They were positive for myeloperoxidase but negative for alpha-naphthyl butylate esterase and chloroacetate esterase stainings. In surface marker analysis YNH-1 cells were positive for CD13, CD33 and CD34. Chromosomal analysis showed 46, XY, der(16)t(16;21)(p11;q22)t(1;16) (q12;q13), der(21)t(16;21)(p11;q22), der (6)t(6;12)(q13;q13), der(12)t(6;12)(q21;q13). These translocations were confirmed by fluorescence in situ hybridization (FISH) studies with the ERG-YAC clone and chromosome-specific DNA libraries. Both the FUS/ERG and ERG/FUS chimeric transcripts were identified by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. Thus, YNH-1 could be a useful tool for elucidating the pathophysiology and molecular mechanism in AML with t(16;21),t(1;16) and 12q13 translocations.

Rapid detection of lymphoma-specific translocations in interphase nuclei of non-Hodgkin's lymphoma by fluorescence in situ hybridization

We have recently developed a method to detect tumor-specific rearrangement of the IgH gene in interphase nuclei by fluorescence in situ hybridization. Tumor-specific IgH gene rearrangement is equivalent to 14q32.33 translocation. Using this approach, we detected 14q32.33 translocation in 29 of 70 patients with B-cell non-Hodgkin's lymphoma (NHL). Chromosome t(3;14) was found in 10 of these 29 patients, and were demonstrated as a fusion signal of BCL6 and VH gene probes in interphase nuclei. Furthermore, in another series of 11 patients and a NHL cell line, we demonstrated t(14;18) and t(11;14) in interphase and metaphase cells with a combination of BCL2 (or PRAD1) with IgH gene probes. Interphase FISH with lymphoma-associated gene probes is a rapid procedure for cytogenetic diagnosis of B-cell NHL.

Mitogen-inducible SIPA1 is mapped to the conserved syntenic groups of chromosome 19 in mouse and chromosome 11q13.3 centromeric to BCL1 in human

Sipa1, previously called Spa1, is transcriptionally induced in the murine lymphoid cells following mitogenic stimulation and encodes a protein with a domain related to Rap1 GTPase activating protein (Rap1GAP) at the N-terminus and to PEST sequences followed by a leucine zipper motif at the C-terminus. Herein mouse genomic Sipa1, which consisted of 16 exons, was cloned. Gene linkage analysis using (BXD) recombinant inbred strains indicated that Sipa1 was mapped to the most centromeric region of chromosome 19 syntenic with the long arm of human chromosome 11. Human SIPA1 cDNA exhibited a striking homology to that of mouse throughout the entire region, with the overall identity being 90% at the amino acid level. Human genomic clones, which hybridized with both mouse and human SIPA1 cDNA but not with RAP1GAP cDNA, were then isolated. Fluorescence in situ hybridization (FISH) analysis using the human genomic clones indicated that SIPA1 was indeed mapped to chromosome 11q13, most likely to the 11q13.3 subregion. It was further indicated by double-color FISH that SIPA1 was located in the centromeric neighborhood of CCND1/ PRAD1, a presumed BCL1 oncogene.

Fusion of the MLL gene with two different genes, AF-6 and AF-5alpha, by a complex translocation involving chromosomes 5, 6, 8 and 11 in infant leukemia

We analysed a complex translocation involving chromosomes 5, 6, 8 and 11 in a case of infant leukemia. Molecular analysis of the MLL gene revealed that MLL was fused with two different genes, AF-6 on chromosome 6q27 and AF-5alpha. AF-5alpha, the 11th partner gene fused with MLL, is a novel gene mapped to chromosome 5q12, which encodes a 31 kDa protein of 269 amino acids and contains a possible nuclear targeting sequence, a potential leucine zipper dimerization motif and an alpha-helical coiled-coil domain. In situ hybridization and molecular cloning analyses demonstrated that two different types of chromosomal recombination had occurred in the cells. One was a three-way translocation among chromosomes 6, 8 and 11, and the other was an insertion of a chromosome 5-derived segment into the breakpoint of chromosomes 8 and 11. Accordingly, the karyotype was defined as del(5)(q11.2q12), der(6)t(6;8) (q27;q11.2), der(8)(8pter-->8q11.2::5q11.2-->5q12::11q23-->++ +11qter), der(11)t(6;11) (q27;q23). Thus, the MLL gene created two different fusion mRNAs, since the chromosome 11 split into two different chromosomes 5 and 6. This is the first report demonstrating fusion of the MLL gene with two different genes by a complex translocation.

Microsatellite instability is an early genetic event in myelodysplastic syndrome but is infrequent and not associated with TGF-beta receptor type II gene mutation

We examined microsatellite instability (MSI) at 10 loci of dinucleotide repeats using the polymerase chain reaction (PCR) in patients with myelodysplastic syndrome (MDS). Bone marrow DNA was obtained from 45 patients repeatedly during the disease course and fibroblast DNA was also collected from 19 of them as a normal control. Three of the 19 patients showed an alteration at more than three loci, when the allele length was compared between their fibroblast DNA and the initial marrow DNA. On the other hand, none of the 45 patients showed an alteration when the initial sample was compared with the latest one. One of the three patients with MSI had refractory anemia and two refractory anemia with ring sideroblasts and none of them showed disease progression, complex chromosome abnormality, karyotypic evolution, or mutation of N-RAS or TP53. Moreover, a frameshift mutation within 10 repeating adenines of transforming growth factor beta type II receptor gene, which was recently recognized as a critical target of MSI, was not found in any of the patients including the three with MSI. These findings suggest that MSI is an early but infrequent genetic event and is independent of other critical genetic aberrations in the development of MDS.

Detection and quantification of TEL/AML1 fusion transcripts by polymerase chain reaction in childhood acute lymphoblastic leukemia

We investigated TEL/AML1 fusion mRNA in 108 children with acute lymphoblastic leukemia (ALL) (86 B-lineage ALL, 15 T-ALL, two mixed lineage ALL, and five other phenotypes) using reverse transcriptase-polymerase chain reaction (RT-PCR). TEL/AML1 transcripts were found in 14 patients (13%) including three relapsed patients, and were unexceptionally limited to B-lineage ALL patients. The incidence of TEL/AML1 transcripts among B-lineage ALL was 16% (14/86). The reciprocal AML1/TEL transcripts were detected in 12 (86%) of the 14 cases expressing a TEL/AML1 transcript. In three cases, the TEL gene was fused to exon 3 of the AML1 gene, and to exon 2 in the remaining cases. To evaluate the amount of TEL/AML1 molecules for the quantification of a minimal residual disease (MRD), a plasmid vector which contained either a long TEL/AML1 PCR product (464 bp) or a short one (425 bp) was used as a competitor. We amplified RNAs obtained from bone marrow (BM) at complete remission or from peripheral blood stem cell (PBSC) harvests in two representative cases. For one PBSC harvest showing a positive result, a competitive PCR was carried out to quantify the amount of MRD. A 1:4 dilution series of competitor vectors was constructed, and each vector was added to a PCR reaction which contain a constant amount of cDNA obtained from the PBSC harvest. An equivalent point was compared to that of corresponding samples at diagnosis. Using this method, MRD in the PBSC harvest was 3.9:10(3). Our results elucidated the incidence, lineage-specificity, and variant forms of TEL/AML1 fusion transcripts in childhood ALL. Since the percentage of other chromosomal translocations in childhood ALL is not more than 5%, TEL/AML1 transcript would be the most feasible clone-specific marker for these patients. In addition, our method could be a powerful tool for quantification of the TEL/AML1 transcript and for the detection of MRD.

Expression of Epstein-Barr virus latent infection genes and oncogenes in lymphoma cell lines derived from pyothorax-associated lymphoma

Malignant lymphomas frequently develop in the pleural cavity of patients with long-standing pyothorax. The term pyothorax-associated lymphoma (PAL) has been proposed for this type of tumor. Most PALs are diffuse lymphomas of the B-cell type and contain Epstein-Barr virus (EBV) DNA. We have established 2 lymphoma cell lines from biopsy specimens of PAL cases, OPL-1 and OPL-2, and examined their growth characteristics and the expression of EBV latent infection genes and oncogenes. OPL-2 exhibited a more rapid growth and higher saturation density than OPL-1, and only OPL-2 exhibited colony-forming activity in soft agar. OPL-1 and -2 were positive for B-cell differentiation markers and showed clonal surface immunoglobulins. Both line contained a single predominant form of episomal EBV DNA, indicating clonal cellular proliferation of an EBV-infected progenitor cell. OPL-1 and -2 contained type B and A EBV genome, respectively. Expression of EBV nuclear antigen (EBNA)2 mRNA and protein was detected by Northern and Western blot analysis in OPL-1, but not in OPL-2. On the other hand, the expression of latent membrane protein (LMP)1 mRNA in both OPL-1 and -2 was extremely weak and detectable only by reverse transcription-polymerase chain reaction. Protein expression of LMP1 was not observed by Western blot analysis or immunocytochemistry. Both lines expressed c-myc mRNA. Only OPL-1 expressed mRNA of c-fgr, an oncogene whose expression is upregulated by EBNA2. Both OPLs expressed bcl-2 mRNA without detectable expression of LMP1 protein.

Non-random chromosomal rearrangements and their implications in clinical features and outcome of multiple myeloma and plasma cell leukemia

Rearrangements of bands 14q32.3 and 19p13.3 and preferential deletion of the short arm of chromosome 1 were nonrandom chromosomal abnormalities in MM and PCL, warranting further investigation at the molecular level. From the viewpoint of clinical relevance, chromosome 14q32 translocation seems to be associated with leukemic manifestation, level of LDH, and shorter survival period from the time of chromosomal analysis. However, these results were obtained from patients with advanced disease, most of whom had already been treated with alkylating agents prior to cytogenetic analysis. To investigate the karyotypes of MM in the early stage and to determine correlations with clinical features, non-dividing cells should be analyzed. For this purpose, interphase FISH and/or comparative genomic hybridization are promising procedures to detect genomic alterations in early multiple myeloma.

Periosteal ganglion: a report of three new cases including MRI findings and a review of the literature

OBJECTIVE

To clarify the clinicopathological features of periosteal ganglion.

DESIGN

Three patients with periosteal ganglion were studied clinicopathologically.

PATIENTS

One patient was selected from the files of our institute and two from a consultation file.

RESULTS AND CONCLUSION

All three lesions were located over the medial aspect of the tibia. Plain radiographs showed cortical erosions of varying degrees and mild periosteal reaction of the medial side of the tibia. MR images demonstrated well-circumscribed lesions overlying the cortical bone of the tibia, shown as low-intensity areas on T1-weighted images. On T2-weighted images, lesions were homogeneous, lobulated, and showed a characteristic markedly increased signal intensity. These findings are helpful in making a diagnosis of periosteal ganglion. Each patient had an uneventful clinical course after an excision involving the wall of the ganglion, the adjoining periosteum, and the underlying sclerotic cortical bone.

1-kW, room-temperature, fast-axial-flow CO laser excited by a radio-frequency discharge

A fast-axial-flow rf-discharge-excited CO laser has been scaled up to produce an output power of more than 1 kW at room temperature (280-290 K). The discharge section is composed of eight discharge tubes, to which rf power is capacitively coupled. An output power of 1220 W is obtained with an Xe-added mixture, with corresponding electrical conversion eff iciency and specific output of 7.9% and 1.8 W/cm(3), respectively. Scaling characteristics of the scheme are discussed. The temperature dependence of the output, the output stability, and the beam properties are also reported.

Tumor-specific rearrangements of the immunoglobulin heavy-chain gene in B-cell non-Hodgkin's lymphoma detected by in situ hybridization

We have recently described the potential use of fluorescence in situ hybridization (FISH) to detect tumor-specific rearrangements of the immunoglobulin heavy-chain (IgH) gene in interphase nuclei. Using yeast artificial chromosome (YAC) clone Y6 containing variable region (VH) gene and bacteriophage clones Ig gamma, we analyzed 70 patients with B-cell non-Hodgkin's lymphoma (NHL) and compared the results with those obtained by the conventional G-banding method. Tumor-specific rearrangements of the IgH gene equivalent to 14q32 translocations were defined as separate signals of VH and Ig gamma genes or those of Ig gamma genes and referred to split signals. Twenty-nine patients (41.4%) showed split signals. Among these, 13 did not show 14q32 translocations by G-banding: three with other chromosomal abnormalities, one with normal karyotype, and nine with no analyzable metaphases. The partner sites of 14q32 translocations were identified in 17 patients by FISH: t(3;14)(q27;q32) including a complex variant was observed in nine patients, t(14;18)(q32;q21) in four, t(8;14)(q24;q32) in three, t(14;19)(q32;q13) in one, and t(11;14)(q13;q32) in one. Six of nine patients with t(3;14) or its variant and one of three with t(8;14) were diagnosed as having respective translocations only by FISH. Translocation t(3;14) was found most commonly, and was correlated histologically with diffuse lymphoma with large-cell components. These results indicate that interphase FISH with IgH gene probes promises to be a rapid and reliable method for use in the diagnosis of B-cell NHL.

Establishment of the novel B acute lymphoblastic leukemia (FAB L3) cell line KHM-10B with a 13q34 abnormality and constitutive expression of c-myc and max during cell cycle

We established and characterized a new acute lymphoblastic leukemia (ALL-L3 according to FAB classification, or Burkitt's type) cell line, KHM-10B. The morphology of the patient's lymphoblasts and KHM-10B cells corresponded to that of ALL-L3 cells. The cells were positive for HLA-DR, CD19 and surface immunoglobulin (mu, lambda). Southern blot analysis revealed that the fresh lymphoblasts and KHM-10B shared the same immunoglobulin gene rearrangement. Conventional cytogenetic analysis of fresh lymphoblasts from the patient and KHM-10B cells revealed the 13q34 abnormality, the second most common additional abnormality in Burkitt's lymphoma, but no detectable 8q24 involvement. Rearrangement of the c-myc oncogene was not detected by Southern blot analysis. However, a fluorescence in situ hybridization (FISH) assay identified a t(8;22)(q24;q11). The KHM-10B cells were arrested at S phase with hydroxyurea and thymidine, and the synchronized cells progressed through the cell cycle in drug-free medium. The expression of c-myc and max was observed throughout the cell cycle, as was found in the Burkitt's lymphoma cell in Raji. Our findings indicate that FISH analysis is of diagnostic value in detecting obscure chromosomal translocations and that max, as well as c-myc, is expressed constitutively in ALL-L3 and Burkitt's lymphoma cell lines.

Translocations and amplification of the BCL2 gene are detected in interphase nuclei of non-Hodgkin's lymphoma by in situ hybridization with yeast artificial chromosome clones

Translocation of the BCL2 gene in B-cell malignancies carrying t(14;18) and amplification of the BCL2 gene in a cell line (HBL-2) derived from a non-Hodgkin's lymphoma (NHL) were detected specifically in both metaphase spreads and interphase nuclei by fluorescence in situ hybridization (FISH) using yeast artificial chromosomes (YACs). A YAC clone containing the BCL2 gene yA153A6, a 360-kb clone spanning from approximately 60 kb upstream of BCL2 exon 1 to approximately 60 kb 3' of the minor breakpoint cluster region, was used for single-color FISH analysis. Seven patients with NHL and one patient with acute lymphoblastic leukemia were analyzed for BCL2 translocations. Interphase nuclei of NHL patients showed three signals when hybridized with the yA153A6 probe. This was expected because the YAC clone spans the BCL2 breakpoint regions on 18q21.3. In a patient with acute lymphoblastic leukemia, a positive signal for BCL2 was detected on der(14) at band 14q32.33 by single-color FISH with the yA153A6 probe, whereas no signals were detected on der(18). The amplification of BCL2 in the HBL-2 cell line was observed on a characteristic abnormal chromosome 18, add(18)(q23); the periodic pattern of the fluorescent signal of this region was suggestive of an amplicon. Using double-color FISH with YAC clones containing the more centromeric 18q21.3 gene gastrin-releasing peptide (y302F10) and the 14q32.33 gene (IgH; Y6), we detected t(14;18) by showing the juxtaposition of the 18q21.3 and 14q32.33 bands on the derivative chromosome 18. Interphase FISH with these YAC clones provided a rapid procedure for the diagnosis of B-cell malignancies carrying t(14;18). In addition, we showed that translocations and amplification of the BCL2 gene can be detected at the single-cell level.

The human thrombopoietin gene is located on chromosome 3q26.33-q27, but is not transcriptionally activated in leukemia cells with 3q21 and 3q26 abnormalities (3q21q26 syndrome)

We previously demonstrated that the EVI-1 gene was transcriptionally activated in the 3q21q26 syndrome and chromosomal breakpoints at 3q26 were clustered within 400 Kb of the EVI-1 gene. Since thrombocytosis is often observed in the 3q21q26 syndrome, we first mapped the thrombopoietin (TPO) gene and then we examined for transcriptional activation and chromosomal rearrangement of the TPO gene in four cases of the 3q21q26 syndrome. The TPO gene was assigned to chromosome 3q26.33-q27 by fluorescence in situ hybridization analysis. Although the TPO gene was mapped to the same locus as the EVI-1 gene, the distance between the TPO gene and the EVI-1 gene at 3q26 was more than 600 Kb and no gross chromosomal rearrangements of the TPO gene were detected by Southern blot analysis and pulsed field gel electrophoresis (PFGE) analysis. TPO transcripts were not detected in these leukemia cells by Northern blot analysis. These results indicate that activation of the TPO gene is not the main cause of thrombocytosis in the 3q21q26 syndrome.

Double mutations of the N-ras gene in a patient with acute myelomonocytic leukemia

We report a patient with acute myelomonocytic leukemia (AMMoL) who showed two independent point mutations of the N-ras gene at codons 12 and 13. Longitudinal analysis revealed that one mutation at codon 13 was detectable throughout his disease course and the other at codon 12 emerged as a second mutation 14 months after the diagnosis was made, at the refractory stage. Cloning to vector and subsequent sequencing confirmed that these mutations occurred in different alleles. Chromosome findings showed a simple abnormal karyotype at presentation and further karyotypic aberrations during his disease course, concomitantly with the second mutation of the N-ras gene. These findings revealed a close relationship among the disease progression, karyotypic evolution and a newly-appearing N-ras mutation.

Interphase and metaphase detection of the breakpoint of 14q32 translocations in B-cell malignancies by double-color fluorescence in situ hybridization

The breakpoint of 14q32 translocations found in B-cell malignancies was delineated specifically in both metaphase spreads and interphase nuclei by double-color fluorescence in situ hybridization (FISH) using bacteriophage clones containing the human immunoglobulin gamma chain gene locus (Ig gamma) and a cosmid clone, CY24-68, containing VH segments. CY24-68 is more telomeric than Ig gamma, separated by approximately 1 megabase (Mb). FISH studies were performed on four patients with non-Hodgkin's lymphoma (NHL), one with acute lymphoblastic leukemia (ALL), one with plasma cell leukemia (PCL), and three cell lines. In each patient with t(8;14), t(14;18), and t(3;14), the signal of Ig gamma gene was observed on der(14) and that of CY24-68 at respective partner sites of these translocations, 8q24.1, 18q21.3, and 3q27. Interphase nuclei with a signal of Ig gamma clearly separated from that of CY24-68 were more frequently encountered in all of the patients (45% to 74%) than those in normal controls (4% to 5%). Even in cases where only interphase nuclei were available for FISH studies, 14q32 translocations are detected as shown in two patients each with NHL and t(11;14)-carrying PCL. In two cell lines, HS-1 derived from ALL carrying t(8;14) and FR4 derived from a plasmacytoma carrying a complex form of t(8;14), the signal of Ig gamma was observed at the breakpoint region 8q24.1 of the der(8) in addition to the der(14), indicating that translocation event occurred within the Ig gamma locus. Intense Ig gamma signal was found at the breakpoint region on the der(14)t(11;14) in HBL-2 derived from NHL, indicating amplification of the Ig gamma gene, and presumably the resultant chimeric DNA between Ig gamma and DNA sequences at 11q13. The present approach allowed us to unequivocally detect tumor-specific breakpoints of 14q32 translocations. Furthermore, interphase FISH provides a rapid diagnostic procedure to detect 14q32 translocations in B-cell malignancies.

Characterization of a 14q+ marker chromosome in philadelphia chromosome positive acute lymphoblastic leukemia by DNA analysis and fluorescence in situ hybridization

We report a case of precursor-B acute lymphoblastic leukemia (ALL) with the Philadelphia chromosome (Ph) and a 14q+ chromosome whose additional material was a part of the long arm of der(9)t(9;22). A minor population carrying the standard Ph translocation without the 14q+ was also observed at the first presentation. The translocation of the BCR gene from chromosome 22 to the subtelomeric region of the 14q+ was confirmed by fluorescence in situ hybridization (FISH) using a yeast artificial chromosome (YAC) clone containing the BCR gene. The breakpoint of chromosome 14 could not be determined exactly but probably was at 14q24 or 14q32 by conventional chromosome analysis. Nevertheless, FISH using a YAC clone containing the human immunoglobulin heavy chain (IgH) gene locus, Southern blot, and pulsed-field gel electrophoresis (PFGE) analyses with IgJH probe, and loss of heterozygosity analysis at the alpha 1-antitrypsin (AT) gene locus showed lack of involvement of the IgH gene in the 14q+ and more centromeric breakage than the alpha 1-AT locus at 14q32.1. Thus, the formation of the 14q+ seemed to be a secondary genetic event after the Ph translocation and presumably played a minor role in the pathogenesis of B-cell malignancy in this case.

[Detection of minimal residual disease by means of FISH and PCR methods and its clinical evaluation]

The monitoring of MRD by FISH and PCR is now clinically evaluated for a prediction of the relapse of leukemia. However, these methods include several technical limitations. In FISH, an appropriate cut off value should be settled for each probe or procedure in estimating chromosomal gain, loss, or translocation and the sensitivity depends on the cut off values but it may reach to 10(-3). In PCR, the sensitivity is higher than that of FISH especially using genomic DNA as a template. However, the detection of chromosomal translocation-specific DNA or RNA constructs is currently applicable to limited cases and the amplification of Ig or TCR gene rearrangement has a major pitfall caused by the clonal evolution. Clinically, MRD can be an indicator for a prediction of the relapse. For example, a greater MRD on entering CR tends to be related with an early relapse, a return to MRD-positive after disappearance of MRD will be a sign of impending relapse, and MRD negativity at the termination of therapy may be correlated with a long-term disease free status. More precise evaluation of MRD is necessary with regard to therapeutic strategy.

[A combined consecutive therapy with fosfomycin and sulbactam/cefoperazone for bacterial infections associated with hematological diseases]

A combination antibacterial therapy with fosfomycin (FOM) and sulbactam/cefoperazone (SBT/CPZ) was applied to 78 patients with severe infections associated with hematological diseases. In this protocol, FOM was followed by SBT/CPZ and each drug was administered for 1 hour intravenously and consecutively. Among 72 evaluable patients, 43 patients had acute leukemia, myeloblastic or lymphoblastic, 22 had malignant lymphoma, 3 had multiple myeloma, and 4 had other hematological diseases as underlying diseases. Bacterial infections diagnosed were sepsis in 21 patients, suspected sepsis in 47, and other infections in 4. The overall efficacy rate of this treatment was 72.2%, and those for individual infections were 66.7% for sepsis, 74.5% for suspected sepsis, and 75.0% for other infectious diseases. Among 22 bacteria separated from patients with sepsis, 78.6% (11/14 strains) were eradicated by this treatment. This protocol was also effective in 57.1% (8/14) of patients whose granulocyte count was less than 100/mm3 during the course of treatment as well as in 83.3% (15/18) of patients with granulocyte count over 500/mm3. There was no difference in effectiveness between those patients to whom G-CSF was administered and those to whom it was not (17/24, 70.8% vs 35/48, 72.9%). As an adverse reaction, a transient increase of GOT and/or GPT was observed in 2 patients (2.8%). The consecutive administration treatment of FOM and SBT/CPZ is thus an effective and safe regimen for the treatment of patients with hematological diseases complicated by severe infections.

Neurofibromatosis 1 gene (NF1) mutation is a rare genetic event in myelodysplastic syndrome regardless of the disease progression

Neurofibromatosis 1 gene (NF1) is a tumor suppressor gene and the product of which down-regulates Nras protein by its GTPase activating protein-related domain (NF1-GRD). Although the incidence of NF1 mutation was reported to be rare in the chronic phase of myelodysplastic syndrome (MDS), there have been no previous reports on its configuration in patients showing the disease progression. We examined NF1 in 50 patients with MDS including 9 who had progressed to more advanced stages and 16 to acute leukemia. Six patients had an Nras mutation. We carried out allele specific restriction analysis (ASRA) to detect a mutation at the first nucleotide A of codon 1423 (AAG), a mutational hot spot. We also employed a polymerase chain reaction mediated single strand conformation polymorphism (PCR-SSCP) method to confirm the result of ASRA and to detect a point mutation in other sequences of FLR exon. In consequence, ASRA disclosed wild type configuration and PCR-SSCP showed no aberrant band in any sample examined whether the samples harboured an Nras mutation or not. We conclude that NF1 mutation does not play a crucial role in the development and the progression of MDS.

Intermediate lymphocytic lymphoma with both t(14;19)(q32.3;q13.1) and t(3;22)(q27;q11.2)

Chromosome translocations involving various chromosomes sites, including the sites of immunoglobulin loci (14q32,2p12,22q11) represent recurrent aberration in non-Hodgkin lymphoma (NHL). We report a novel case of intermediate lymphocytic lymphoma (ILL) with both t(14;19)(q32.3;q13.1) and t(3;22)(q27;q11.2). The t(14;19)(q32.3;q13.1) and t(3;22) (q27;q11.2) may represent reciprocal recombinations between immunoglobulin (Ig) H chain gene (14q32.3) and bcl-3(19q13.1) and between Ig lambda chain gene (22q11.2) and bcl-6 (3q27), respectively.

CAG expansions in a novel gene for Machado-Joseph disease at chromosome 14q32.1

We have identified a novel gene containing CAG repeats and mapped it to chromosome 14q32.1, the genetic locus for Machado-Joseph disease (MJD). In normal individuals the gene contains between 13 and 36 CAG repeats, whereas most of the clinically diagnosed patients and all of the affected members of a family with the clinical and pathological diagnosis of MJD show expansion of the repeat-number (from 68-79). Southern blot analyses and genomic cloning demonstrates the existence of related genes. These results raise the possibility that similar abnormalities in related genes may give rise to diseases similar to MJD.

Nonrandom chromosomal rearrangements of 14q32.3 and 19p13.3 and preferential deletion of 1p in 21 patients with multiple myeloma and plasma cell leukemia

Structural chromosomal abnormalities and their break-points were characterized in 17 patients with multiple myeloma (MM) and 4 with plasma cell leukemia by banding. Chromosome 14q32 translocations with a variety of partners were detected in 13 patients, and a variant translocation t(8;22)(q24.1;q11) was detected in 1. Three recurrent 14q32 translocations have been identified: t(6;14)(p21.1;q32.3) occurring in 3 cases, and t(11;14)(q13;q32.3) and t(14;18) (q32.3;q21.3) each occurring in 2 cases. Translocations t(1;14)(q21;q32.3), t(3;14)(p11;q32),t(7;14)(q11.2;q32.3), and t(11;14)(q23;q32.3) were found in each patient, whereas in the remaining 2 patients, partner chromosomes could not be determined. The band 19p13.3 was newly delineated as a recurrent breakpoint involved in translocations in MM. Chromosomes 1 and 6 were also commonly involved in structural abnormalities (14 and 10 patients, respectively), although no particular bands were noted. However, the short arm of chromosome 1 was preferentially involved in deletion, suggesting a certain antioncogene on 1p associated with the development of myeloma. In addition; fluorescence in situ hybridization was successfully applied to determine the nature of the structural abnormalities in a patient with t(8;22) translocation. The present findings suggest that there may be subsets of 14q32 translocations specific to MM.