Biomedical subjects

N Kamada

Publications and source records attributed to N Kamada.

At least 109 records · Page 6Linked to original sources

PubMed1997

A role for macrophage scavenger receptors in atherosclerosis and susceptibility to infection.

Macrophage type-I and type-II class-A scavenger receptors (MSR-A) are implicated in the pathological deposition of cholesterol during atherogenesis as a result of receptor-mediated uptake of modified low-density lipoproteins (mLDL). MSR-A can bind an extraordinarily wide range of ligands, including bacterial pathogens, and also mediates cation-independent macrophage adhesion in vitro. Here we show that targeted disruption of the MSR-A gene in mice results in a reduction in the size of atherosclerotic lesions in an animal deficient in apolipoprotein E. Macrophages from MSR-A-deficient mice show a marked decrease in mLDL uptake in vitro, whereas mLDL clearance from plasma occurs at a normal rate, indicating that there may be alternative mechanisms for removing mLDL from the circulation. In addition, MSR-A-knockout mice show an increased susceptibility to infection with Listeria monocytogenes or herpes simplex virus type-1, indicating that MSR-A may play a part in host defence against pathogens.

Animals↗

PubMed1997

Frequent jumping translocations of chromosomal segments involving the ABL oncogene alone or in combination with CD3-MLL genes in secondary leukemias.

Seven secondary leukemia patients were treated for solid tumors or malignant lymphoma with anticancer drugs or radiation. We studied bone marrow samples from these patients by fluorescence in situ hybridization (FISH). Of the seven patients, three had increased signals for the ABL oncogene (9q34) on interphase nuclei and at metaphase. One of the three patients also had four signals for the CD3 (MLL) region (11q23). Whole painting probes revealed that these chromosomal regions were translocated onto structurally abnormal chromosomes, resulting in partial tri-, tetra- or penta-somy of these regions. We called this type of translocation "segmental jumping translocation (SJT)." SJT of the ABL oncogene was not detected in samples from 15 patients with de novo acute myelocytic leukemia (AML), 12 with myelodysplastic syndrome (MDS), or 20 with chronic myelocytic leukemia (CML) at the chronic phase. Furthermore, monosomy 7 was also found in the patients with the gene amplification. These results indicate that SJT of ABL and/or CD3 (MLL) genes is associated with the leukemogenesis of secondary leukemia. The SJT may be one mechanism of gene amplification.

Aged↗

PubMed1997

The prevention of graft-versus-host disease by the serum of liver retransplanted rats.

The effect of serum from orthotopic liver retransplanted rats (re-OLT serum) on graft-versus-host disease (GVHD) was studied in rats. In the re-transplantation model of rat liver, orthotopic liver transplantation (OLT) was carried out in the DA (RT1a) into PVG (RT1c) combination; two days later the DA liver was removed and a new PVG liver implanted into the same recipient (re-OLT). In the in vivo GVHD model, male PVG rats were sublethally irradiated and injected intravenously with 3 x 10(8) DA or BN (RT1n) spleen through the penial vein. Within 1 h of the inoculation, rats of the experimental group were injected with 1 ml of re-OLT serum taken at postoperative day (POD) 7. Rats in the control group received 1 ml of normal PVG serum or syngeneic re-OLT serum (PVG-PVG, PVG-PVG). All PVG rats in the control groups died of GVHD within 21 days after the inoculation of DA or BN spleen lymphocytes. However, when the animals were treated with re-OLT serum, 100% (6/6) of the rats survived more than 60 days, following inoculation with DA lymphocytes but not with BN lymphocytes. The POD 7 re-OLT serum showed a strong inhibition against DA anti-PVG mixed lymphocyte reaction (MLR), although re-OLT serum did not contain soluble DA class I antigens, anti-DA class I or II antibody. The potential GVHD inhibitory factors in re-OLT serum may be two unique immunosuppressive proteins, which have been detected by SDS PAGE and reported previously. We conclude that re-OLT serum has immunosuppressive factors, which, at least in part, prevented the induction of GVHD in rats.

Animals↗

PubMed1997

Application of fluorescence in situ hybridization to detect residual leukemic cells with 9;22 and 15;17 translocations.

We performed fluorescence in situ hybridization (FISH) upon 9;22 and 15;17 translocation-positive bone marrow cells to monitor the clinical course of 46 patients with chronic myelocytic leukemia (CML) and nine with acute promyelocytic leukemia (AML M3) who received chemotherapy and/or bone marrow transplantation (BMT). M-BCR-ABL and PML-RAR alpha probes were used to detect translocations of t(9;22) and t(15;17), respectively. Signals from CML patients treated with interferon (17 patients) or BMT (29 patients) were 0.5-15% positive for the 9;22 translocation. Among nine M3 patients who received extensive chemotherapy or BMT, 1-5% were positive for the 15;17 translocation. A highly sensitive FISH procedure using both translocation probes and a whole chromosome Y probe was established and applied to eight sex-mismatched BMT patients (seven CML and one AML M3), in which 0.1-0.6% of signals positive for the specific translocations were detected. These results suggested that interphase FISH is powerful enough to identify minor cell populations of 9;22 or 15;17 translocations after therapy, as well as to detect specific chromosome abnormalities at diagnosis.

Bone Marrow↗

PubMed1997

Alterations of p16 and p15 genes in acute leukemia with MLL gene rearrangements and their correlation with clinical features.

p16 and p15 genes are putative tumor suppressor genes located on chromosome 9p21. In acute leukemias, alterations of p16 and p15 genes have been reported to occur exclusively in lymphoid lineage. We analyzed alterations of p16 and p15 genes in 46 acute leukemias with MLL gene rearrangements by Southern blot analysis, and investigated the association with clinical characteristics. We identified homozygous deletion of p16 and p15 genes in five (19%) of 27 acute lymphoblastic leukemias (ALLs) and in two (11%) of 19 acute myeloid leukemias (AMLs). Patients with homozygous deletion of p16 and p15 genes showed higher average leukocyte counts (343 x 10(9)/l vs 271 x 10(9)/l) and lower estimated 2-year survival rates than those with normal p16 and p15 genes (14.3 vs 30.7%), although the differences were not statistically significant. In addition, we investigated mutation of p16 gene by polymerase chain reaction single strand conformation polymorphism (PCR-SSCP) in 31 patients, but no mutation was found in the patients tested. Our results suggest that alterations of p16 and p15 genes are involved in a subset of acute leukemias with MLL gene rearrangement not only of lymphoid but also of myeloid phenotype. Homozygous deletion of p16 and p15 genes may be a possible adverse prognostic factor, although further analysis would be needed to confirm it.

Adolescent↗

PubMed1997

Alterations of p53 and Rb genes in a novel human GM-CSF-dependent myeloid cell line (OHN-GM) established from therapy-related leukaemia.

A novel GM-CSF-dependent myeloid cell line, OHN-GM, was established from a patient who developed acute myelogenous leukaemia (AML) as a consequence of myelodysplastic syndrome (MDS). As the patient had previously received cytotoxic chemotherapy for Hodgkin's disease, the MDS and AML were probably related to such therapy. Sequential karyotypic analysis established a del(5q) as the initial cytogenetic abnormality. Additional alterations, including t(10;13)(q24;q14), had developed subsequently during disease progression. Southern blot analysis of OHN-GM cells suggested deletion of one allele of the IRF-1 gene, although no aberrant transcripts were detected. Fluorescence in situ hybridization analysis revealed the deletion of the Rb gene due to the t(10;13)(q24;q14) translocation, and Western blot analysis demonstrated the absence of Rb protein in OHN-GM cells. Finally, the OHN-GM cells exhibited two missense point mutations in highly conserved regions of the p53 gene. These observations suggest that a multistep process, involving alterations of Rb and p53 genes, may have contributed to the patient's disease development and progression. To our knowledge, OHN-GM is the first cell line derived from a therapy-related AML. These cells may aid the investigation of leukaemogenesis as well as the biology of secondary leukaemia.

Antigens, Surface↗

PubMed1997

Genetic analysis of 8;21 chromosomal translocation without AML1 gene involvement in MDS-AML.

We have investigated a case of acute myelocytic leukaemia derived from myelodysplastic syndrome (MDS-AML) with an 8;21 translocation. In this case the AML1/MTG8 (ETO) fusion transcript was not detected by reverse transcriptase-polymerase chain reaction (RT-PCR), and the rearrangement of the AML1 gene locus was not detected by Southern blot nor pulse field gel electrophoresis (PFGE) analyses using specific probes for the AML1 gene. Fluorescence in-situ hybridization (FISH) study using cosmid probes for 21q22 revealed that the breakpoint of 21q22 was telomeric to the AML1 gene locus and centromeric from D21S259, 351, 3421 loci. This is the first report concerning the t(8;21)(q22;q22) carrying AMLs (de novo AML, MDS-AML and therapy-related AML) to show that the breakpoint at 21q22 is located outside the AML1 gene locus. It is also noteworthy that the cell-surface antigen expression pattern of the bone marrow (BM) blasts was changed from CD7+ CD2+ CD13+ CD33+ CD19- CD11b+ CD14+ CD36+ to CD7- CD2- CD13+ CD19+ CD11b- CD14- CD33+ CD34+ CD36- CD56+ during leukaemic progression, and the pattern in leukaemic phase was similar to the characteristic phenotype of de novo AML cases with t(8;21), when the AML1/MTG8 fusion transcripts are always detected by RT-PCR.

Blotting, Southern↗

PubMed1997

Alopecia areata associated with myasthenia gravis and thymoma: a case of alopecia with marked improvement following thymectomy and high level prednisolone administration.

A 57-year-old Japanese woman who suffered from alopecia areata associated with myasthenia gravis (MG) and thymoma responded well to thymectomy and high doses of glucocorticosteroid administration. Several treatments for alopecia areata including administration of systemic prednisolone were attempted, but loss of hair on the scalp progressed. After thymectomy and high level glucocorticosteroid administration for MG, the lesions on the scalp improved within four weeks. Consequently, we suggest that this thymectomy and high level glucocorticosteroid administration assisted in improving the immune dysfunction causing the alopecic lesions in this patient.

Alopecia Areata↗

PubMed1997

Detection of residual host cells in sex-mismatched bone marrow transplantation in various hematological diseases by fluorescence in situ hybridization.

Thirty-eight sex-mismatched bone marrow transplantation patients with various hematological diseases were followed-up using fluorescence in situ hybridization. Probes specific for various translocations, the X chromosome (DXZ1) and the whole Y chromosome (WCP Y), were used to assess successful engraftment and residual host cells. The combination of translocation and WCP Y probes enabled the identification of host and donor cells in addition to the identification of malignant vs. normal cells in the transplant recipient. Fifteen patients were sequentially followed up. The results obtained using the combination of translocation plus WCP Y probes were more reliable than those with DXZ1 plus WCP Y probes, or the translocation probe alone, especially when the percentage of residual leukemic cells detected by the translocation probe alone was around the cut-off level.

Bone Marrow Transplantation↗

PubMed1997

Production of 5,8,11-Eicosatrienoic Acid (Mead Acid) by a (Delta)6 Desaturation Activity-Enhanced Mutant Derived from a (Delta)12 Desaturase-Defective Mutant of an Arachidonic Acid-Producing Fungus, Mortierella alpina 1S-4.

Enhanced production of 5,8,11-eicosatrienoic acid (Mead acid, 20:3(omega)9) was attained by a mutant fungus, Mortierella alpina M209-7, derived from (Delta)12 desaturase-defective M. alpina Mut48. The 20:3(omega)9 production by M209-7 was 1.3 times greater than that by its parent strain, Mut48. This is thought to be due to its enhanced (Delta)6 desaturation activity, which was 1.4 times higher than that of Mut48. In both strains, 87 to 88% of the total lipids comprised triacylglycerol (TG) and 85% of 20:3(omega)9 was contained in TG. On optimization of the culture conditions for M209-7, earlier glucose feeding and shifting of the growth temperature from 28 to 19(deg)C on the second day were shown to be effective. Under the optimal conditions with a 10-liter jar fermentor, 20:3(omega)9 production reached 1.65 g/liter of culture medium (corresponding to 118 mg/g of dry mycelia and 28.9% of total fatty acids), which is about twice that reported previously (0.8 g/liter).

Journal Article↗

PubMed1997

Germ-line contribution of embryonic stem cells in chimeric mice: influence of karyotype and in vitro differentiation ability.

The effect of the karyotype and the ability to differentiate in vitro upon germ-line transmission by A3-1 embryonic stem (ES) cells in chimeric mice were examined. Germ-line transmission was confirmed in ES cells exhibiting 38% and more of the normal karyotype, but no chimeric mice and/or germ-line transmitters were observed regardless of the karyotype when the cystic embryoid body (CEB) was formed on day 8 and later in the suspension culture. Germ-line transmission of the ES cells was not significantly influenced by formation of the simple embryoid body (SEB). Germ-line transmitters were preferentially observed in chimeras when the ES cell contribution to coat color was markedly increased, but this contribution to coat color varied regardless of the karyotype or in vitro differentiation ability. These results suggest that A3-1 ES cells which exhibit CEB at 7 days after suspension culture and approximately 40% of normal karyotype are capable of germ-line transmission in chimeric mice.

Animals↗

PubMed1997

Characterization of acute leukemia with t(4;12).

Acute leukemia with t(4;12)(q11-13;p12-13) is rare but has unique characteristics. The incidence of t(4;12) in acute leukemias was about 0.6% in our laboratory. Twelve patients with acute leukemia with t(4;12) have been reported until now. They included eight acute myeloid (AML: M0 2, M1 3, M2 1, M4 1, and M7 1), three acute lymphoblastic (ALL: L1) and one acute unclassified leukemia (AUL). There were some differences between adults and children with t(4;12). The eight adult patients included seven with AML and one with AUL, two of whom had a history of exposure to mutagenic agents and/or genotoxic therapy. Three patients had the CD7+ HLA-DR+ CD13+ CD34+ c-kit+ phenotype, suggesting that the leukemic cells were of stem cell origin. Four children expressed the B lymphoid phenotype (HLA-DR+ CD10+ CD19+) although one had myeloperoxidase positivity. It was difficult for adult patients to achieve complete remission with the usual therapy regimen, whereas children with t(4;12) seemed to be easier to treat. Rearrangement of the TEL gene located on the short arm of chromosome 12 (12p13), was investigated in two adult patients. FISH analysis using the YAC probe that covers the TEL gene region, revealed split signals in these patients, suggesting a break inside or near the TEL gene. The t(4;12) abnormality is associated with unique characteristics of acute leukemia namely stem cell or secondary AML in adults, and B lymphoid leukemia in children.

Acute Disease↗

PubMed1997

Clonal identification of trisomies 3, 5 and X in angioimmunoblastic lymphadenopathy with dysproteinemia by fluorescence in situ hybridization.

Trisomies 3, 5 and X in six Japanese patients with AILD were detected by fluorescence in situ hybridization (FISH). Trisomies 3 and X were detected using centromeric probes. Cosmid probes locating on 5q31.1, the commonly deleted region, was used to detect trisomy 5. FISH detected three patients with trisomy 3 alone, one with trisomy 5 alone and one with all the three trisomies analysed. The sample that showed all three aberrations was further analysed by dual color FISH. The three trisomies were present on different cells. The AILD cells with trisomy 5 tended to replicate slowly, whereas those with trisomy 3 seem to have a proliferative advantage. An increase in the histopathological stage was reflected in the increase in the percentage of trisomy 3 cells in one patient.

Aged↗

PubMed1997

Sequential interphase FISH analysis of m-BCR/ABL chimeric gene-positive cells in Ph-positive acute myeloid leukemia.

We report a case of Philadelphia (Ph)-positive AML in which interphase fluorescence in situ hybridization (FISH) analysis was performed from diagnosis throughout the course of therapy using major (M-) breakpoint cluster region (BCR)/minor (m-) BCR and ABL cosmid probes. We also investigated the existence of the M-BCR or m-BCR at the RNA or DNA level by the reverse transcriptase polymerase chain reaction and Southern blot analysis, respectively. Complete remission with a normal karyotype was achieved after several regimens of chemotherapy and peripheral blood stem cell transplantation (PBSCT), but relapse occurred and his cells became 100% Ph-positive. We detected the m-BCR/ABL fusion gene by interphase FISH analysis using an m-BCR/ABL translocation probe, and found that FISH analysis was useful for classifying the BCR, identifying minimal residual disease, and for predicting imminent relapse after chemotherapy and PBSCT.

Acute Disease↗

PubMed1997

The multiple roles of macrophage scavenger receptors (MSR) in vivo: resistance to atherosclerosis and susceptibility to infection in MSR knockout mice.

Both type I and type II MSRs are integral membrane proteins containing a collagenous domain and elicit an extraordinarily wide range of ligand binding capability. They were found during the search for the molecule(s) responsible for the accumulation of modified LDL during atherogenesis. However, all prior the evidence relating to their physiological and pathophysiological roles in vivo had been indirect. Targeted disruption of the MSR gene results in a reduction in the size of atherosclerotic lesions in an apo E deficient animal. Macrophages from MSR deficient mice exhibit a marked decrease in modified LDL uptake in vitro, whereas modified LDL clearance from plasma remains normal, suggesting that there are alternative mechanisms for the uptake of modified LDL from the circulation. In addition, MSR knockout mice are more susceptible to L. monocytogenes and HSV-1 infection, indicating a role for MSR in host defense against various pathogens.

Animals↗

PubMed1997

Clinical importance of interleukin-2 receptor alpha-chain expression in acute leukemia. The Japan Cooperative Group of Leukemia/Lymphoma.

To clarify the clinical importance of interleukin-2 (IL-2) receptor (IL-2R) expression in acute leukemia, we examined 517 adult patients with acute leukemia and CML blast crisis (CML-BC). IL-2R alpha was expressed in 42/311 AML, 5/11 acute unclassified leukemia, 24/116 pre-B ALL, 2/32 T-ALL, and 27/47 CML-BC, while IL-2R beta was expressed only in 2 T-ALL. Expression of IL-2R alpha was closely associated with that of different lineage markers, CD11b, CD34, and Ph1+ abnormality. IL-2R alpha(+) non-T leukemic cells did not respond to IL-2. Clinical outcome of IL-2R alpha (+) leukemia showed lower response to conventional chemotherapy and poorer prognosis than IL-2R alpha (-) cases. Serum IL-2R alpha level in IL-2R alpha (+) cases increased at the onset. Our findings indicate the diagnostic importance of IL-2R alpha expression in acute leukemia as a prognostic risk factor with a close relation to the particular cellular characteristics.

Acute Disease↗

PubMed1997

Nuclear proteins binding to the recombination hotspot region of the retinoic acid receptor alpha gene.

Acute promyelocytic leukemia (APL) has been characterized by 15;17 chromosomal translocation, which involves the retinoic acid receptor alpha (RARA) gene on chromosome 17 and the PML gene on chromosome 15. An extremely restricted region (ERR) of 50 bps within the second intron of the RARA gene was identified as the cluster region of breakpoints by sequencing analyses. ERR was tested by in vitro transfection-recombination assay, and was shown to be the recombination hot spot. In this study, presence of DNA binding proteins to the 148 bps DNA fragment which contains ERR was confirmed by gel-mobility shift analysis in the nuclear extract of NIH3T3 cells and human leukemia cell lines. Furthermore, in vitro study with the mouse sarcoma cell lines using the recombination reporter plasmid containing ERR showed that ERR might be involved in the homologous recombination in addition to the illegitimate recombination. The DNA binding proteins specific to ERR might play an important role in chromosome translocation.

3T3 Cells↗

PubMed1996

Establishment and characterization of a novel acute promyelocytic leukemia cell line (UF-1) with retinoic acid-resistant features.

All-trans retinoic acid (RA) induces complete remission in a high proportion of patients with acute promyelocytic leukemia (APL). Nevertheless, most of these patients develop RA resistance and relapse. The mechanisms of RA resistance by APL cells are still unclear. To understand the characteristics of human leukemia, human leukemic cell lines are useful tools for study. APL cells have a strikingly low proliferation potential in vitro; thus, only one APL cell line has been established. We developed a novel APL cell line (UF-1) from a patient clinically resistant to all-trans RA. Cell surface markers in the UF-1 cells were positive for CD7, CD13, CD33, and CD38. Cytogenetic analyses revealed additional abnormalities, 46XX, add(1)(q44), add(6)(q12), add(7)(q36), t(15;17) (q21;q21). Molecular analyses showed a PML/RAR alpha fusion transcript. Sequence analysis of the RAR alpha gene in RA-resistant HL-60 cells disclosed a point mutation in codon 411 (C to T substitution), whereas UF-1 cells showed the normal sequence. All-trans RA did not change morphological features of the cell, NBT reduction activity, or their expression of CD11b antigens as determined by FACS analysis except at 10(-6) mol/L. RA also did not alter the growth curve of the cells as determined by the MTT assay. These findings suggest that the UF-1 cell is the first permanent cell line with spontaneous RA-resistant APL cells. This RA-resistant APL cell line may be a useful model for molecular studies on the block of leukemic cell differentiation and as a means to investigate the mechanisms of RA resistance.

Adult↗