PubMed Health⌕ Search

Biomedical subjects

R Hanada

Publications and source records attributed to R Hanada.

At least 73 records · Page 4Linked to original sources
PubMed1996

Infrequent mutations of the TP53 gene and no amplification of the MDM2 gene in hepatoblastomas.

We have investigated the mutation of the TP53 gene in hepatoblastomas (HBLs) by using polymerase chain reaction-single strand conformation polymorphism and direct sequencing in 38 HBL tumor samples and in two HBL cell lines. We detected the TP53 gene mutation in an anaplastic hepatoblastoma cell line, but no aberration of the TP53 gene (exons 5-9) was found in tumor samples and in the other HBL cell line. The mutation of the cell line was a missense mutation from GAC (asparagine) to CAC (histidine) at codon 281, which was different from the G-to-T transversion of codon 249 that is frequently found in adult hepatocellular carcinomas (HCCs). In addition, we performed Southern blot analysis of the MDM2 gene, but we did not find MDM2 gene amplification in 19 cases tested. Our results suggest that, in contrast to the findings in HCCs in adults, TP53 gene aberrations are not involved in the development or progression of HBLs in children.

Adult↗
PubMed1996

Homozygous deletions of p16/MTS1 and p15/MTS2 genes are frequent in t(1;19)-negative but not in t(1;19)-positive B precursor acute lymphoblastic leukemia in childhood.

We analyzed 60 B precursor acute lymphoblastic leukemia (ALL) primary samples and 15 cell lines for homozygous deletions of p16 and p15 genes and mutations of p16 gene. These included five cell lines and 13 primary samples with the t(1;19)(q23;pl3), and eight primary samples with the t(9;22)(q34;qll). Of 10 cell lines without t(1;19), homozygous deletion of both p16 and p15 genes was found in eight cell lines (80%), and a rearrangement of p16 in one cell line (10%). In contrast, only one (20%) of the five cell lines with t(1;19) showed homozygous deletion or rearrangement of p16/p15 gene. Thirteen of 60 (22%) primary samples demonstrated p16 gene homozygous deletion. No case with t(1;19) showed homozygous deletion of p16 gene (0/13, 0%), while cases without t(1;19) showed considerable incidence of p16 gene homozygous deletion (13/47, 28%). These results suggest that the incidence of deletions of p16 gene differs according to the subtypes of B precursor ALL. We also compared the frequency of p16 gene homozygous deletion between the patients at diagnosis and at relapse. Nine of 45 (20%) samples at diagnosis and four of 22 (18%) samples at relapse showed p16 homozygous deletions. The similarity of the rate in these two groups raises the question of the role of p16 gene in progression of B precursor ALL. Mutations were found in three of the primary cases (5%); the mutations included two nonsense mutations at codon 72 and one missense mutation at codon 98. All the mutations found in this study were heterozygous, and the clinical relevance of p16 gene mutation is yet to be determined in these case

Base Sequence↗
PubMed1996

Frequency and clinical significance of the MLL gene rearrangements in infant acute leukemia.

We have analyzed the frequency and clinical significance of the MLL gene rearrangements in 42 cases of infant acute leukemias; including 37 cases of acute lymphoblastic leukemia (ALL) and five cases of acute myeloid leukemia (AML). MLL gene rearrangements were found in 27 of the 37 ALL cases (73 percent), and in all five AML cases. Cytogenetic studies showed 11q23 abnormalities in 24 of 27 ALL cases with MLL gene rearrangements. MLL gene rearrangements were significantly correlated with absence of CD10 expression and poor prognosis, but not with age under 6 months, hyperleukocytosis, myeloid-associated antigen expression, or CNS leukemia. The 3-year overall survival rate for ALL cases with MLL gene rearrangements was 5.3 +/- 5.2 percent, compared with 88.9 +/- 10.5 percent for cases with germline MLL (P=0.0001). Absence of CD10 expression was also associated with poor prognosis (9.9 +/- 6.6 percent vs 85.7 +/- 13.2 percent, P = 0.0003). Of the five AML cases, three have remained alive for 27 months to 67 months. These findings suggest that infant ALL with MLL gene rearrangement is strongly associated with poor prognosis. We consider that infant ALL should be treated on different chemotherapy protocols according to the presence or absence of MLL gene rearrangement.

Antigens, CD↗
PubMed1996

[Bone marrow transplantation from an unrelated donor in patient with congenital heart diseases].

A 9-year-old with chronic myelogenous leukemia (CML) who received bone marrow transplantation from an unrelated donor (UBMT), is reported. He also suffered from congenital heart disease (CHD) consisting of corrected transposition of the great arteries and dextrocardia. The cardiac output was within normal limits. The conditioning regimen included busulfan, melphalan, ALG and TLI. Cyclophosphamide was not used because of it cardiotoxicity. The HLA-phenotype of the donor was identical with that of the patient. DNA typing showed was haplodentical DRB1. The patient is alive 18 months after the UBMT. This case showed that UBMT was possible in a CML patient with CHD, without congestive heart failure.

Adult↗
PubMed1995

EWS-FLI-1 and EWS-ERG chimeric mRNAs in Ewing's sarcoma and primitive neuroectodermal tumor.

The t(11;22)(q24;q12) and t(21;22)(q22;q12) are specific chromosomal translocations found in the Ewing family of tumors including ES, PNET and Askin tumors. In these translocations, the amino-terminal portion of the EWS gene located in 22q12 fuses to the carboxyl-terminal portion of the FLI-1 gene located in 11q24 or the ERG gene located in 21q22, which belong to the ets oncogene superfamily of transcription activators. We investigated the chimeric mRNAs of 15 ESs (7 cell lines and 8 tumor samples) and 7 PNETs (3 cell lines and 4 tumor samples) using the RT-PCR method and sequencing. We detected 2 types of EWS-ERG chimeric mRNA in 2 ES cell lines and 1 PNET tumor sample in addition to 4 types of EWS-FLI-1 chimeric mRNA in 11 ESs (4 cell lines and 7 tumor samples) and 4 PNETs (2 cell lines and 2 tumor samples). There seemed to be no association between the type of chimeric mRNA and clinical features such as sex, age, primary site and histopathology of the patients. All of the chimeric mRNAs are generated from in-frame junctions and are thought to encode fusion proteins that may be the molecular mechanism involved in the Ewing family of tumors.

Adolescent↗
PubMed1995

Allelotype of neuroblastoma.

Although relatively high incidence of loss of heterozygosity (LOH) on chromosomes 1p, 11q, and 14q have been reported in neuroblastoma, it is still unclear whether or not LOH occurs specifically on these chromosome arms in neuroblastoma since only a few chromosomal arms have been examined for LOH in previous studies. Therefore, we screened 81 cases of tumors for LOH on all 22 autosomes and chromosome X using 35 restriction fragment length polymorphism markers and eight microsatellite markers. High incidence of LOH (> 20%) was observed on six chromosome arms; 1p (26%), 2q (30%), 9p (36%), 11q (24%), 14q (22%), and 18q (31%). Frequencies of LOH on other chromosome arms were less than 13%. Patients with 9p LOH in the tumors showed statistically significant association with advanced stage of the disease and poor prognosis (P = 0.037 and P = 0.003, respectively) independently from N-myc amplification, while LOH on other chromosomes did not show association with stage, prognosis, and N-myc amplification. Thus, besides LOH on chromosomes 1p, 11q, and 14q, LOH on chromosomes 2q, 9p, and 18q also occurs relatively frequently in neuroblastoma, indicating the involvement of multiple tumor suppressor genes in the development of neuroblastoma. It is possible that there is a novel tumor suppressor gene on chromosome 9p which is involved in the progression of neuroblastoma.

Alleles↗
PubMed1995

Homozygous deletions of p16/MTS1 gene are frequent but mutations are infrequent in childhood T-cell acute lymphoblastic leukemia.

Fifty-six primary childhood T-cell acute lymphoblastic leukemia (T-ALL) samples and 17 T-ALL cell lines were examined for mutations and homozygous deletions of the p16/MTS1 gene using polymerase chain reaction single-strand conformation polymorphism and Southern blot analysis. Homozygous deletions were found in 22 primary samples (39%) and in 10 cell lines (59%). In contrast, mutations including small deletions and/or insertions were identified in only 4 primary samples (7%) and in 2 cell lines (12%). Mutations included samples (7%) and in 2 cell lines (12%). Mutations included one nonsense mutation at codon 72, one missense mutation at codon 58, one deletion (29 bp from codon 52-61), one insertion (7 bp into codon 50), and two deletion/insertions (codon 63 and intron 1). Four of the six mutations caused subsequent stop codon and presumably produced truncated p16 protein. Our results suggest that p16 gene alterations are involved in the development of T-ALLs and that the inactivation of the p16 gene occurs mainly through homozygous deletions rather than mutations.

Base Sequence↗
PubMed1995

Mutations of the p53 and ras genes in childhood t(1;19)-acute lymphoblastic leukemia.

We have investigated the alterations of p53 and ras genes including H-, K-, and N-ras genes in 22 acute lymphoblastic leukemia (ALL) cases and five cell lines carrying t(1;19) by use of polymerase chain reaction (PCR)-single-strand conformation polymorphism (SSCP) analysis and direct sequencing. The mutations of the p53 gene were found in 2 of 20 t(1;19)-ALL cases at diagnosis (10%), all of 4 cases at relapse (100%), and 4 of the 5 cell lines (80%). Four of the five patients who died had missense mutations at codons 49, 177, 179, and 248. In cases examined sequentially, one had the same point mutation at codon 179 at both diagnosis and relapse, and another had the same p53 gene mutation at codon 240 both in leukemic cells at relapse and in a cell line derived at that time. The other case had no mutation at diagnosis but had the mutation at codon 177 at relapse and cell lines derived from blast cells at diagnosis, suggesting that a small number of leukemic cells with the p53 gene mutation at diagnosis might have escaped PCR-SSCP analysis. In cell lines, SCMC-L9 had three point mutations in the p53 gene at codons 175, 248, and 358, whereas SCMC-L10 had frame shift at codons 209-211. One case had a rare polymorphism at codon 11. We found only one mutation of the N-ras gene that was a 2-bp substitution of GGT(Gly) to GTC(Val) at codon 13 among 22 t(1;19)-ALL cases and five cell lines. This case showed no mutation of the p53 gene and has had a good course. These results suggest that in t(1;19)-ALL, mutations of the p53 and ras genes are infrequent at diagnosis and that p53 gene alterations may be associated with relapse phase or progression of t(1;19)-ALL.

Adolescent↗
PubMed1995

Mass screening and age-specific incidence of neuroblastoma in Saitama Prefecture, Japan.

PURPOSE: To provide the population-based incidence rate of neuroblastoma and to determine the effect of mass screening on the annual age-specific incidence of the tumor in Saitama Prefecture, Japan, from 1981 to 1992. METHODS: Data on screened infants and patients detected by the screening were obtained from the records of the Prefectural Screening Center. Data on neuroblastomas in this area were obtained from the Children's Cancer Registry of the Saitama Prefectural Government (Prefectural Registry) and from the Japan Children's Cancer Registry (National Registry). Population data were obtained from the Prefectural Census. Mass screening for 6-month-old infants was performed by qualitative assessment of urinary vanillylmandelic acid (VMA) from June 1981 to September 1989 and by quantitative measurement of VMA/creatinine (Cre) and homovanillic acid (HVA)/Cre from October 1989 to December 1992. RESULTS: Between 1981 and 1992, 199 cases of neuroblastoma, which include 74 cases detected by mass screening, were identified in Saitama Prefecture. The incidence rate for children under 15 years of age increased from 6.4/10(6) to 20.1/10(6), that for children 0 to 4 years of age increased from 17.0/10(6) to 64.1/10(6), and that for infants under 1 year of age increased from 27.9/10(6) to 260.4/10(6) during these 12 years. No significant reduction in the incidence rate was observed for children over 1 year of age. CONCLUSION: The incidence rate for children under 15 years of age increased with mass screening. The rate for infants was sharply increased, with no corresponding decrease in the rate for children at older ages. These data suggest that there is a subset of neuroblastoma that can be detected by mass screening at 6 months of age but would not be diagnosed later clinically.

Adolescent↗
PubMed1994

Histologic activity of the liver in children with transfusion-associated chronic hepatitis C.

Adults with chronic hepatitis C develop cirrhosis over a period of 6 to 20 years, but there are few reports of this disorder in children. To determine the histologic activity of chronic hepatitis C in children, we examined 31 biopsy specimens from 25 children (age range 3-16 years) with this disease. All patients were seropositive for antibody to hepatitis C virus by second-generation testing, and for HCV-RNA by the polymerase chain reaction. All cases were transfusion-associated. Patients were divided into two groups according to underlying disease: malignant disease or aplastic anemia (Group A, 17 cases) and non-malignant disease (Group B, eight cases). All patients in Group A, but only one in Group B, had received multiple transfusions. All patients in Group A had received intensive courses of cytotoxic and immunosuppressive agents. The histologic diagnosis was made using the standard criteria and Knodell's histology activity index. Chronic persistent hepatitis was more common in Group B (six patients) than in Group A (three patients). Chronic aggressive hepatitis 2B was found only in Group A (five patients). The mean histology activity index score was higher in Group A than in Group B (8.5 vs. 5.7). Six patients (four in Group A and two in group B) subsequently had a liver biopsy. The pathological diagnosis did not change after the second biopsy in any patient in Group B, while two patients in Group A showed a rapid progression of hepatitis. In each category of the histology activity index, periportal necrosis and intralobular necrosis were more severe in Group A than in Group B.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

[Perioperative management of ventricular septal defect and right coronary cusp prolapse in a patient with hemophilia A].

We performed an open heart surgery for ventricular septal defect and right coronary cusp prolapse in a 5-year-old boy with hemophilia A. He has only 3.5% of factor VIII activity. This paper describes a successful perioperative management of hemophilia A. Previous infusion study of factor VIII concentrate showed an administration of 500 units of factor VIII increased its level from 3.5 to 25% two hours after the infusion. With this result we administered 1,500 units of concentrate 14 and 2 hours before the operation, factor VIII level was 201% after the induction of anesthesia. Sternotomy was uneventfully performed. Subarterial VSD was patch closed and right coronary cusp hung down into the defect was plicated. After intra cardiac repair, we administered 2,000 units of VIII factor concentrate, followed by an injection of protamin and its level was 240% at CCU. During the initial 3 postoperative day, patient was maintained with 1,500 units of factor VIII every 12 hours. Chest drains were removed on 2 postoperative day with no evidence of bleeding. Additional infusion of 1,000 units per a day was continued on postoperative days 4 through 17th. Subsequently factor VIII level was maintained more than 60%, so that we achieved successful perioperative course in a patient with hemophilia A.

Aortic Valve Prolapse↗
PubMed1994

[A study of E2A gene in childhood acute lymphoblastic leukemia].

E2A gene rearrangements and E2A-PBX1 chimeric mRNA produced by t(1;19) were examined in 50 cases with acute lymphoblastic leukemia (ALL). Nine of 10 ALL cases with t(1;19) showed the rearrangement by Southern blotting using the E2A gene probe when digested with Xba I, Bgl II, and Eco RI, and the remaining one having hyperdiploidy which was considered to be a sign of good prognosis, lacked E2A rearrangement. Six of 7 ALL cases with t(1;19) that were tested showed the predicted 164 bps band of E2A-PBX1 chimeric mRNA by reverse transcriptase-polymerase chain reaction (RT-PCR), while a case having t(1;19) without E2A rearrangement and 10 cases lacking t(1;19) did not. Three ALL cases tested did not have E2A-PBX1 mRNA at the time complete remission 4 months after diagnosis. Forty ALL cases lacking t(1;19), including 4 cases with t(11;19), did not reveal rearrangement of E2A. We conclude that t(1;19)-ALL can be molecularly diagnosed, and minimal residual disease could be detected by the RT-PCR method.

Adolescent↗
PubMed1994

Clonal expansion of p53 mutant cells in leukemia progression in vitro.

Using the polymerase chain reaction followed by single-strand conformation polymorphism (PCR-SSCP) analysis and direct nucleotide sequence determination, the p53 gene was analyzed in six fresh leukemia samples from which cell lines with p53 mutations were established. Mutations of the p53 gene which were identical to those in the cell lines were observed in three of the fresh samples. In the other three samples, p53 gene mutations were not detected by the conventional PCR-SSCP method. However, when analyzed using allele-specific gene amplification, less than 10% of the leukemic cell population of the three samples, which were below the detection threshold of PCR-SSCP, were shown to have p53 gene mutations. Two samples taken at the initial presentation of two patients, whose relapse samples were shown to contain p53 mutant clones, were also available for analysis. A small population of clonal cells, comprising less than 1% of the population, was shown to have p53 gene mutations in both of these initial samples. These observations provide a potential biologic basis for the frequent findings of p53 mutations in leukemia cell lines and also suggest a potential role for p53 mutations in the clonal overgrowth of cells responsible for relapse of the disease.

Acute Disease↗
PubMed1993

Mutations of the p53 gene are involved in Ewing's sarcomas but not in neuroblastomas.

We have investigated the frequency of p53 gene mutations in Ewing's sarcoma (ES) and neuroblastoma (NB) by using polymerase chain reaction-single strand conformation polymorphism analysis for genomic DNA or complementary DNA generated from total RNA. Mutations of the p53 gene were found in six of seven ES cell lines: a missense mutation of TGC (Cys)-->TAC (Try) at codon 141 in one, a missense mutation of CGT (Arg)-->TGT (Cys) at codon 273 in one, a missense mutation of TGC (Cys)-->TTC (Phe) at codon 176 in three, and one base deletion of CGC-->CG at codon 283 in one. Further analysis of 14 ES and related primary tumors showed mutations of the p53 gene in only two: one base insertion of CCG-->CCCG at codon 152 in one and a missense mutation of GGC (Gly)-->GTC (Val) at codon 154 in the other. Both of the two tumors were obtained from patients with an advanced stage disease. Three of the eight ESs with mutations of the p53 gene showed the same missense mutation at codon 176, suggesting the mutational hot spot of the p53 gene in ESs. In contrast to ES, none of 6 NB cell lines or 48 NB tumors including advanced-stage ones with or without N-myc amplification showed any aberration of the p53 gene. Our findings suggest that mutations of the p53 gene in ES might represent late genetic events related to tumor progression, and that aberrations of the p53 gene might not be involved in the development or the progression of NB.

Adolescent↗
PubMed1993

Epstein-Barr virus-infected T lymphocytes in Epstein-Barr virus-associated hemophagocytic syndrome.

The clonal composition of EBV-infected cells was examined in three cases of EBV-associated hemophagocytic syndrome by analysis of the heterogeneity of terminal repetitive sequences in the EBV genome, indicating monoclonal expansion of EBV-infected cells in all cases. Involvement of T lymphoid cells was determined by in situ hybridization using 35S-labeled RNA probes specific for the small EBV-encoded nuclear RNAs, EBER1 and EBER2, in combination with immunostaining for the TCR-beta chain, CD45RO, CD20, CD30 and CD68 antigens in these three cases. The majority of lymphoid cells showing EBER transcripts were stained by antibodies against CD45RO and T cell receptor-beta. In contrast, EBER-specific signals were not detectable on B cells or hemophagocytic cells. These data support the concept that EBV-associated T cell proliferation is a primary feature of EBV-AHS.

Adolescent↗
PubMed1993

Clinical significance of TAL1 gene alteration in childhood T-cell acute lymphoblastic leukemia and lymphoma.

The TAL1 gene is altered as a consequence of t(1;14)(p32;q11) found in T-cell acute lymphoblastic leukemia (ALL) and shows site specific recombination (tald rearrangement). We investigated TAL1 gene alterations in 39 children with T-cell ALL, in 32 with B-precursor ALL, in three with ALL with myeloid-associated antigen, and in 18 with T-non-Hodgkin's lymphoma (T-NHL). tald rearrangement was found in nine of 39 T-cell ALL patients using Southern blot analysis with a TAL1 gene probe. Polymerase chain reaction (PCR) products predicted from the sequences of the corresponding tald alleles were shown in all of these patients. In contrast, no rearranged band was observed in other kinds of leukemia or in T-NHL patients. All of these patients with tald rearrangement had CD1- CD2+ CD4- CD7+ CD10- pheno-type. Of these, seven were classified as stage I thymic differentiation, and eight have survived for three to 59 months remission. Four of seven patients investigated had normal karyotypes, which has been reported to be associated with a good prognosis in T-cell ALL. We conclude that tald rearrangement is restricted to T-cell ALL, for which it provides a useful clonal marker. Such patients with this rearrangement may constitute a subgroup of T-cell ALL with a good prognosis.

Adolescent↗
PubMed1993

Analysis of the target cell for Epstein-Barr virus infection in Epstein-Barr virus associated hemophagocytic syndrome (EBV-AHS).

Epstein-Barr virus (EBV) infected cells were examined in three cases of EBV-associated hemophagocytic syndrome (EBV-AHS) by analysis of the heterogeneity of terminal repetitive sequences in the EBV genome, indicating monoclonal expansion of EBV-infected cells in all cases. Involvement of T lymphoid cells was determined by the finding of in situ hybridization using [35S]-labeled RNA probes specific for the small EBV-encoded nuclear RNAs, EBER1 and EBER2, in combination with immunostaining for the TCR-beta chain, CD45RO, CD20, CD30 and CD68 antigens in these three cases. The majority of lymphoid cells showing EBER transcripts were stained by antibodies against CD45RO and TCR-beta. In contrast, EBER-specific signals were not detectable on B cells or hemophagocytic cells. These data support the concept that subclinical EBV-associated T cell proliferation is the primary characteristic of EBV-AHS, rather than proliferations of hemophagocytosing histiocytes.

Adolescent↗