Biomedical subjects

Ikuo Miura

Publications and source records attributed to Ikuo Miura.

At least 19 recordsLinked to original sources

PubMed2007

Prognostic impact of chromosomal alteration of 3q27 on nodal B-cell lymphoma: correlation with histology, immunophenotype, karyotype, and clinical outcome in 329 consecutive patients.

Rearrangements involving the BCL6 gene are found in 30% of diffuse large B-cell lymphomas (DLBCLs). We evaluated the clinical characteristics and prognoses of patients with B-cell lymphoma carrying 3q27 translocations. Among the 59 patients having 3q27 translocation, 10.9% had follicular lymphoma (FL) and 23.1% had DLBCL. It is of interest that the prognostic significance was not found between FL and DLBCL with 3q27 translocations. Progression-free survival (PFS) rate was significantly higher in the FL patients with 3q27 translocation than in those with 18q21 translocation. PFS rate was significantly higher in the DLBCL patients with 3q27 translocation than in those with 18q21 translocation. These findings suggest that the presence of 3q27 translocation is a significant prognostic factor in DLBCL.

Adult↗

PubMed2006

A series of ENU-induced single-base substitutions in a long-range cis-element altering Sonic hedgehog expression in the developing mouse limb bud.

Mammal-fish-conserved-sequence 1 (MFCS1) is a highly conserved sequence that acts as a limb-specific cis-acting regulator of Sonic hedgehog (Shh) expression, residing 1 Mb away from the Shh coding sequence in mouse. Using gene-driven screening of an ENU-mutagenized mouse archive, we obtained mice with three new point mutations in MFCS1: M101116, M101117, and M101192. Phenotype analysis revealed that M101116 mice exhibit preaxial polydactyly and ectopic Shh expression at the anterior margin of the limb buds like a previously identified mutant, M100081. In contrast, M101117 and M101192 show no marked abnormalities in limb morphology. Furthermore, transgenic analysis revealed that the M101116 and M100081 sequences drive ectopic reporter gene expression at the anterior margin of the limb bud, in addition to the normal posterior expression. Such ectopic expression was not observed in the embryos carrying a reporter transgene driven by M101117. These results suggest that M101116 and M100081 affect the negative regulatory activity of MFCS1, which suppresses anterior Shh expression in developing limb buds. Thus, this study shows that gene-driven screening for ENU-induced mutations is an effective approach for exploring the function of conserved, noncoding sequences and potential cis-regulatory elements.

Animals↗

PubMed2006

Intravascular large B-cell lymphoma (IVLBCL): a clinicopathologic study of 96 cases with special reference to the immunophenotypic heterogeneity of CD5.

Intravascular large B-cell lymphoma (IVLBCL) is pathologically distinct with a broad clinical spectrum and immunophenotypic heterogeneity. A series of 96 patients with IVLBCL (median age, 67 years; range, 41-85 years; 50 men) was reviewed. Anemia/thrombocytopenia (84%), hepatosplenomegaly (77%), B symptoms (76%), bone marrow involvement (75%), and hemophagocytosis (61%) were frequently observed. The International Prognostic Index score was high or high-intermediate in 92%. For 62 patients receiving anthracycline-based chemotherapies, median survival was 13 months. CD5, CD10, Bcl-6, MUM1, and Bcl-2 were positive in 38%, 13%, 26%, 95%, and 91% of tumors, respectively. All 59 CD10- IVLBCL cases examined were nongerminal center B-cell type because they lacked the Bcl-6+MUM1- immunophenotype. CD5 positivity was associated with a higher prevalence of marrow/blood involvement and thrombocytopenia and a lower frequency of neurologic abnormalities among patients with CD10-IVLBCL. Compared with 97 cases of de novo CD5+CD10-diffuse LBCL, 31 cases of CD5+CD10-IVLBCL exhibited higher frequencies of poor prognostic parameters, except age. Multivariate analysis in IVLBCL revealed that a lack of anthracycline-based chemotherapies (P<.001, hazard ratio [HR]: 9.256), age older than 60 years (P=.012, HR: 2.459), and thrombocytopenia less than 100x10(9)/L (P=.012, HR: 2.427) were independently unfavorable prognostic factors; CD5 positivity was not. Beyond immunophenotypic diversity, IVLBCL constitutes a unique group with aggressive behavior.

Adult↗

PubMed2006

t(8;14)(q24;q32) in two patients with CD10-negative primary thyroid diffuse large B-cell lymphoma.

Diffuse large B-cell lymphoma (DLBCL) with the 8q24 translocation is occasionally seen in the gastrointestinal tract, but has rarely been reported in the thyroid gland. We experienced two cases of primary thyroid DLBCL having t(8;14)(q24;q32). The immunophenotype and karyotype of Case 1 (66-year-old female) and Case 2 (70-year-old female) were: CD10-, CD20+, BCL-2+/add(13)(q34), t(8;14)(q24;q32) and CD10-, CD20-, CD79a+, BCL-2-/t(8;14)(q24;q32), respectively. Although long-term complete remission could be achieved in both of our patients by conventional chemotherapy with/without radiation therapy, accumulation of further such cases is necessary to develop a standard treatment protocol and also to elucidate the pathogenesis of t(8;14)(q24;q32)-positive primary thyroid DLBCL.

Aged↗

PubMed2006

An XX/XY sex microchromosome system in a freshwater turtle, Chelodina longicollis (Testudines: Chelidae) with genetic sex determination.

Heteromorphic sex chromosomes are rare in turtles, having been described in only four species. Like many turtle species, the Australian freshwater turtle Chelodina longicollis has genetic sex determination, but no distinguishable (heteromorphic) sex chromosomes were identified in a previous karyotyping study. We used comparative genomic hybridization (CGH) to show that C. longicollis has an XX/XY system of chromosomal sex determination, involving a pair of microchromosomes. C-banding and reverse fluorescent staining also distinguished microchromosomes with different banding patterns in males and females in approximately 70% cells examined. GTG-banding did not reveal any heteromorphic chromosomes, and no replication asynchrony on the X or Y microchromosomes was observed using replication banding. We conclude that there is a very small sequence difference between X and Y chromosomes in this species, a difference that is consistently detectable only by high-resolution molecular cytogenetic techniques, such as CGH. This is the first time a pair of microchromosomes has been identified as the sex chromosomes in a turtle species.

Animals↗

PubMed2006

Multicenter phase II study of the CyclOBEAP (CHOP-like + etoposide and bleomycin) regimen for patients with poor-prognosis aggressive lymphoma.

Our aim was to study the efficacy of the addition of etoposide and bleomycin to a [cyclophosphamide (CPA), doxorubicin (DXR), vincristine (VCR), and prednisone (PDN)] CHOP-like regimen for the treatment of aggressive lymphoma. The CyclOBEAP regimen was administered over a total period of 12 weeks. Doxorubicin, 50 mg/m(2), was given every 2 weeks in combination with either cyclophosphamide, 1,000 mg/m(2), (weeks 1, 5, 9) or etoposide, 70 mg/m(2) qd x4 (weeks 3, 7, 11). During the alternate weeks, non-myelosuppressive vincristine, 1.4 mg/m(2) (maximum, 2.0 mg/body), was given either with bleomycin, 10 mg/m(2) (weeks 2, 6, 10), or alone (weeks 4,8,12). Prednisolone, 40 mg/m(2), was administered daily for 14 days during weeks 1-2, 5-6, and 9-10. There were 121 eligible patients and median age of 51 years. A complete response was achieved in 106 patients (88%) and a partial response in 11 patients. The 5-year overall survival (OS) rate was 72% and progression-free survival (PFS) rate was 62%. When the patients were divided according to the International Prognostic Index (IPI), the 5-year OS and PFS rates did not significantly differ among risk groups. When the patients with DLBCL were divided according to the IPI, the 5-year OS and PFS rates also did not significantly differ. World Health Organization (WHO) grade 4 neutropenia was observed in 91 patients and thrombocytopenia in 13 patients. No treatment-related deaths were observed. The addition of etoposide and bleomycin to CHOP therapy may enhance the effect of CHOP therapy for aggressive lymphoma. We will perform a prospective study of CyclOBEAP regimen combined with rituximab and test its safety and efficacy.

Adolescent↗

PubMed2006

Multicenter Phase II study of CyclOBEAP regimen for elderly patients with poor-prognosis aggressive lymphoma.

We treated elderly patients (65-69 years) who had aggressive lymphoma with the CyclOBEAP regimen, and we studied the safety and efficacy of this treatment. The CyclOBEAP regimen was administered over a total period of 12 weeks. Doxorubicin 40 mg/m(2) was given every 2 weeks in combination with either cyclophosphamide 800 mg/m(2) or etoposide 70 mg/m(2) qd x 3. During the alternate weeks, non-myelosuppressive vincristine 1.0 mg/m(2) was given either with bleomycin 10 mg/m(2) or alone. Prednisolone 40 mg/m(2) was administered daily for three 14-day periods during weeks 1-2, 5-6 and 9-10. There were 51 eligible patients. A complete response was achieved in 42 patients (82%). The 5-year overall survival (OS) rate was 60.6% and progression-free survival (PFS) rate was 51.8%. WHO grade 4 neutropenia was observed in 32 patients and thrombocytopenia in 8 patients. We showed that the CyclOBEAP regimen can be safely used in the treatment of aggressive lymphoma in elderly patients and it achieved a high rate of remission.

Aged↗

PubMed2006

Multicentre phase II study of the baseline BEACOPP regimen for patients with advanced-stage Hodgkin's lymphoma.

A German Hodgkin's lymphoma (HL) study group designed the BEACOPP (bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, prednisolone) regimen. In the BEACOPP regimen, treatment intervals were shortened and the dose-intensity was increased compared with those in the ABVD regimen (doxorubicin, bleomycin, vinblastine and darcarbacine), resulting in a long-term disease-free survival rate of approximately 75-80%. In the present study, we evaluated the safety and efficacy of the BEACOPP regimen. Between April 2001 and February 2004, 20 patients with HL of stage IIB or higher who had received no previous treatment were enrolled. The patients were aged 17-69 years (median 22 years). The histologic types were mixed cellularity in four cases and nodular sclerosis in 16 cases. The stages were stage IIB in four cases, stage III in 12 cases, and stage IV in four cases. Nineteen (95%) of the 20 patients achieved complete remission. The 3-year survival rate was 100% and the 3-year progression-free survival rate was 89.7%. Adverse drug reactions were grade 4 neutropenia in 12 patients, grade 3-4 thrombocytopenia in seven patients, and grade 3 or higher non-hematologic toxicities in two patients (stomatitis in one patient and ALT/AST elevation in one patient). The BEACOPP regimen for advanced-stage HL showed an excellent complete remission rate and high efficacy even in stage III/IV patients. However, a long-term risk of the BEACOPP regimen is the development of secondary leukemia or myelodysplastic syndrome. Therefore, long-term follow-up of these patients, including monitoring for toxicities, is necessary.

Adolescent↗

PubMed2006

Successful reduced-intensity hematopoietic stem cell transplantation in myelodysplastic syndrome with severe coronary artery disease.

A 60-year-old Japanese man with myelodysplastic syndrome (MDS) and effort angina was referred to our clinic for treatment of MDS. The patient was transfusion-dependent and displayed coronary artery disease (CAD) with 99% obstruction of the left anterior descending coronary artery. Treatment comprised reduced-intensity hematopoietic stem cell transplantation with administration of fludarabine phosphate (180 mg/m(2)) and busulfan (8 mg/kg), followed by allogeneic peripheral blood stem cell transplantation from an HLA-matched sister. The regimen was well tolerated, and engraftment occurred rapidly without any therapy-related complications, including cardiovascular attack. Sex chromosome analysis by fluorescence in situ hybridization revealed complete donor chimerism on day 29 for bone marrow cells and on day 59 for peripheral blood leukocytes. The patient became transfusion-independent on posttransplantation day 8. As of 22 months postoperatively, he remains well, with 100% Karnofsky performance status, a limited type of chronic graft-versus-host disease, and no recurrence of disease. The clinical course of the patient suggests that this preparative regimen allows safe allogeneic stem cell transplantation for MDS patients with severe CAD.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2006

Acute myelomonocytic leukemia with dysplastic bone marrow eosinophils showing t(5;17)(q13;q11) and a secondary chromosomal aberration, inv(16)(p13q22).

inv(16)(p13q22) is associated with de novo acute myelomonocytic leukemia with dysplastic bone marrow eosinophils (AMML Eo), which has a relatively favorable clinical course with a longer remission duration and better survival prospects. On the other hand, t(5; 17)(q13;q11), although relatively rare, has been reported to be a component of complex chromosomal abnormalities in myelodysplastic syndromes and secondary acute myeloid leukemia (AML). We treated a 29-year-old woman with the first reported case of de novo AMML Eo with inv(16)(p13q22) in addition to t(5; 17)(q13;q11). Although she attained complete remission (CR) immediately after induction therapy, the disease recurred 1 year after the completion of consolidation therapies. She underwent HLA-matched unrelated allogeneic bone marrow transplantation (UBMT), together with a myeloablative conditioning regimen, after achieving a second CR and has survived without a recurrence for more than 24 months since UBMT. In general, certain secondary chromosomal abnormalities are associated with the phenotype of the disease, which retains its essential biologic characteristics established by the primary abnormality. Accordingly, the primary nature of the leukemic cells in this case differs from the findings for core-binding factor AML with inv(16)(p13q22). We believe this report is the first of de novo AMML Eo with t(5; 17)(q13;q11) showing as a secondary chromosomal aberration with inv(16)(p13q22).

Adult↗

PubMed2006

[Acute monoblastic leukemia with tetrasomy 8].

Tetrasomy 8 is a rare chromosomal abnormality in acute leukemia, and it has recently been considered as a poor prognostic factor. A 20-year-old woman was admitted because of purpura on the upper and lower limbs in February 2002. On admission, her leukocyte count was 6.5 x 10(9)/l with 66% of blasts, the hemoglobin level was 11.2 g/dl, and the platelet count was 101 x 10(9)/l. The bone marrow aspirate contained 85.6% of peroxidase-negative, alpha-naphthyl-butyrate esterase-positive, and CD4+ CD56+ blast cells. Karyotypic analysis of the bone marrow cells showed 48, XY, + 8, + 8[17]/47, XY, +8[3]. The patient was diagnosed as having AML (M5a), and treatment with daunorubicin (70 mg x 5 days) and cytosine arabinoside (150 mg x 7 days) resulted in a complete remission. She relapsed four months later, however, with an extramedullary tumor in T12. Remission could not be achieved, and the patient underwent allogeneic peripheral blood stem cell transplantation from her HLA-identical mother. Her clinical course was almost uneventful except for a phlegmon in the right leg, but on day 49 a relapse occurred, and she died of acute renal failure on day 73. This case strongly illustrates the characteristic of tetrasomy 8 as a poor prognostic factor in acute leukemia.

Adult↗

PubMed2005

The dragon lizard Pogona vitticeps has ZZ/ZW micro-sex chromosomes.

The bearded dragon, Pogona vitticeps (Agamidae: Reptilia) is an agamid lizard endemic to Australia. Like crocodilians and many turtles, temperature-dependent sex determination (TSD) is common in agamid lizards, although many species have genotypic sex determination (GSD). P. vitticeps is reported to have GSD, but no detectable sex chromosomes. Here we used molecular cytogenetic and differential banding techniques to reveal sex chromosomes in this species. Comparative genomic hybridization (CGH), GTG- and C-banding identified a highly heterochromatic microchromosome specific to females, demonstrating female heterogamety (ZZ/ZW) in this species. We isolated the P. vitticeps W chromosome by microdissection, re-amplified the DNA and used it to paint the W. No unpaired bivalents were detected in male synaptonemal complexes at meiotic pachytene, confirming male homogamety. We conclude that P. vitticeps has differentiated previously unidentifable W and Z micro-sex chromosomes, the first to be demonstrated in an agamid lizard. Our finding implies that heterochromatinization of the heterogametic chromosome occurred during sex chromosome differentiation in this species, as is the case in some lizards and many snakes, as well as in birds and mammals. Many GSD reptiles with cryptic sex chromosomes may also prove to have micro-sex chromosomes. Reptile microchromosomes, long dismissed as non-functional minutiae and often omitted from karyotypes, therefore deserve closer scrutiny with new and more sensitive techniques.

Animals↗

PubMed2005

Implementation of the modified-SHIRPA protocol for screening of dominant phenotypes in a large-scale ENU mutagenesis program.

SHIRPA is a three-stage protocol for the comprehensive assessment of primarily mouse behavior. The first stage consists of high-throughput phenotyping of 33 behavioral observations and 7 metabolic or disease observations. We modified this part of the protocol by integrating new morphologic observations into the initial phenotype assay of behavior and dysmorphology. Behavioral observations assessed by this protocol, now referred to as the "modified-SHIRPA," are compatible with the original "SHIRPA" protocol. Using modified-SHIRPA, we screened dominant phenotypes of more than 10,000 G(1) progeny generated by crossing DBA/2J females with ENU-treated C57BL/6J males. To date, we have obtained 136 hereditary-confirmed mutants that exhibit behavioral and morphologic defects. Some independent mutant lines exhibited similar phenotypes, suggesting that they may represent alleles of the same gene or mutations in the same genetic pathway. They could hold great potential for the unraveling of the molecular mechanisms of certain phenotypes.

Animals↗

PubMed2005

Enamelin (Enam) is essential for amelogenesis: ENU-induced mouse mutants as models for different clinical subtypes of human amelogenesis imperfecta (AI).

Amelogenesis imperfecta (AI) is a group of commonly inherited defects of dental enamel formation, which exhibits marked genetic and clinical heterogeneity. The genetic basis of this heterogeneity is still poorly understood. Enamelin, the affected gene product in one form of AI (AIH2), is an extracellular matrix protein that is one of the components of enamel. We isolated three ENU-induced dominant mouse mutations, M100395, M100514 and M100521, which caused AI-like phenotypes in the incisors and molars of the affected individuals. Linkage analyses mapped each of the three mutations to a region of chromosome 5 that contained the genes encoding enamelin (Enam) and ameloblastin (Ambn). Sequence analysis revealed that each mutation was a single-base substitution in Enam. M100395 (Enam(Rgsc395)) and M100514 (Enam(Rgsc514)) were putative missense mutations that caused S to I and E to G substitutions at positions 55 and 57 of the translated protein, respectively. Enam(Rgsc395) and Enam(Rgsc514) heterozygotes showed severe breakage of the enamel surface, a phenotype that resembled local hypoplastic AI. The M100521 mutation (Enam(Rgsc521)) was a T to A substitution at the splicing donor site in intron 4. This mutation resulted in a frameshift that gave rise to a premature stop codon. The transcript of the Enam(Rgsc521) mutant allele was degraded, indicating that Enam(Rgsc521) is a loss-of-function mutation. Enam(Rgsc521) heterozygotes showed a hypomaturation-type AI phenotype in the incisors, possibly due to haploinsufficiency of Enam. Enam(Rgsc521) homozygotes showed complete loss of enamel on the incisors and the molars. Thus, we report here that the Enam gene is essential for amelogenesis, and that mice with different point mutations at Enam may provide good animal models to study the different clinical subtypes of AI.

Amelogenesis↗

PubMed2005

Primary effusion lymphoma of the pericardial cavity carrying t(1;22)(q21;q11) and t(14;17)(q32;q23).

We report a case of primary effusion lymphoma (PEL) in a 75-year-old woman without human immunodeficiency virus or hepatitis C virus, which presented as fever, chest pain, and pericardial effusion. The lymphoma cells were positive for CD20 and CD79a, and were negative for CD3 and CD10. Genomic human herpes virus 8 (HHV-8) and Epstein-Barr virus were not detected in the lymphoma cells. Cytogenetic analysis showed complex abnormalities by the G-banding technique, and spectral karyotyping (SKY) analysis provided more detailed characterization of the chromosomal aberrations, including t(1;22)(q21;q11) and t(14;17)(q32;q23). We did not detect C-MYC gene rearrangement or BCL-2 expression. She was treated successfully with six courses of the CHOP regimen. The present case demonstrated a rare category of PEL that is not associated with HHV-8 or C-MYC gene rearrangement. In addition, SKY analysis disclosed cryptic chromosomal abnormalities involving 1q21 and 17q23.

Aged↗

PubMed2005

Cytogenetic features of de novo CD5-positive diffuse large B-cell lymphoma: chromosome aberrations affecting 8p21 and 11q13 constitute major subgroups with different overall survival.

De novo CD5-positive diffuse large B-cell lymphoma (CD5(+)DLBCL) is regarded as a different clinicopathological entity from CD5-negative DLBCL (CD5(-)DLBCL) and mantle cell lymphoma (MCL). Because only a few published cytogenetic studies of de novo CD5(+)DLBCL are available, we investigated chromosomal changes in 23 Japanese patients who had de novo CD5(+)DLBCL. A characteristic of cytogenetic abnormalities in de novo CD5(+)DLBCL was a high incidence of chromosomal aberrations affecting 8p21 and 11q13. Major chromosomal breakpoints were concentrated at 8p21, 11q13, and 3q27. Patients with 8p21 aberrations showed aggressive clinical features, including advanced stage of disease, elevated serum LDH level, poor performance status, and an inferior survival curve compared with patients who had 11q13 changes (P = .043). Chromosomal abnormalities of both 8p21 and 11q13 were not observed in the same patient, and each abnormality showed different chromosomal gains and losses. These results indicate that de novo CD5(+)DLBCL may occur in previously unidentified subgroups that differ in their chromosomal abnormalities. The conflicting results of previous studies on prognosis may thus be explained in part by the differences in chromosomal changes.

Adult↗

PubMed2005

Origins of mouse inbred strains deduced from whole-genome scanning by polymorphic microsatellite loci.

Microsatellite loci are uniformly distributed at approximately 100-kbp intervals on all chromosomes except the chromosome Y, and genetic information about more than 9000 loci and high-throughput polymorphism analysis are now available. Taking advantage of these properties, we carried out whole-genome scanning using eight common inbred strains (CIS) of laboratory mice, including A/J, C57BL/6J, CBA/J, DBA/2J, SM/J, SWR/J, NC/Nga, and 129/SvJ, and eight wild-derived inbred strains (WIS), BGL2/Ms, CAST/Ei, JF1/Ms, MSM/Ms, NJL/Ms, PGN2/Ms, SK/CamEi, and SWN/Ms. We selected and located 1226 informative loci at 1.2-cM average intervals on all of the chromosomes of the 16 strains and compared the polymorphisms of the eight CIS with those from the eight WIS as subspecies representatives. More than 50% of the loci can be identified as WIS (therefore, subspecies-specific) alleles in the CIS genomes. We also discovered that the CIS chromosomes form a mosaic structure with an average ratio of domesticus to non-domesticus alleles of 3:1. Furthermore, the domesticus alleles were present much more frequently on the CIS chromosome X than on their autosomes, suggesting that successive backcrossing of non-domesticus stocks to domesticus stocks had been undergone at the beginning of CIS history.

Animals↗

PubMed2005

Fluorescence in situ hybridization monitoring of BCR-ABL-positive neutrophils in chronic-phase chronic myeloid leukemia patients during the primary stage of imatinib mesylate therapy.

We describe a method for monitoring chronic myeloid leukemia (CML) patients treated with imatinib that uses fluorescence in situ hybridization (FISH) to detect BCR-ABL in peripheral blood (PB) granulocytes. First, we compared this method, termed Neutrophil-FISH, with interphase FISH (i-FISH) analysis of bone marrow (BM), i-FISH analysis of PB mononuclear cells, and conventional cytogenetic analysis (CCA) of BM in 30 consecutive CML patients. We found the percentage of BCR-ABL-positive neutrophils as determined by Neutrophil-FISH to correlate best with the percentage of Philadelphia chromosome-positive metaphases in the BM determined by CCA (y = 0.8818x + 5.7249; r(2) = 0.968). We then performed a serial Neutrophil-FISH study of 10 chronic-phase CML patients treated with imatinib and found that the technique could clearly separate imatinib responders from nonresponders within 12 weeks of drug administration. There was a significant difference in the percentages of BCR-ABL-positive neutrophils between responder (mean 3 SD, 18.2% 3 11.8%) and nonresponder (82.4% 3 5.1%) groups at 12 weeks (P < .0001, Student t test).Together with real-time quantitative polymerase chain reaction analysis, Neutrophil-FISH represents another useful method for monitoring CML patients during the primary myelosuppressive stage of imatinib therapy because it is a quick, simple, and reliable method for assessing cytogenetic response.

Antineoplastic Agents↗