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Biomedical subjects

K Akashi

Publications and source records attributed to K Akashi.

At least 91 records · Page 5Linked to original sources
PubMed1995

Quantitative analysis of AML1/ETO transcripts in peripheral blood stem cell harvests from patients with t(8;21) acute myelogenous leukaemia.

Peripheral blood stem cells (PBSC) have been used increasingly for haemopoietic reconstitution after marrow-ablative chemotherapy in patients with acute leukaemia because of the possibility that there is a lower risk of leukaemic contamination. We have developed a titration assay using a competitive reverse transcriptase polymerase chain reaction (RT-PCR) which is able to estimate the number of AML1/ETO transcripts so that minimal residual disease (MRD) can be monitored quantitatively in patients with t(8;21) acute myelogenous leukaemia (AML). Using a qualitative RT-PCR method, AML1/ETO transcripts could be detected in all samples from 15 first PBSC harvests and 11 second PBSC harvests obtained from 15 patients with t(8;21) AML. With our competitive RT-PCR assay, the number of AML1/ETO transcripts was found to be lower in the second PBSC harvest than that in the first in every individual. Furthermore, MRD in PBSC harvests was less than that in the corresponding bone marrow obtained on the day of PBSC collection in the individual patients studied. In 10 patients who received autologous blood stem cell transplantation (ABSCT), we could not find a relationship between the number of AML1/ETO transcripts in the infused PBSC harvests and the clinical outcome after ABSCT. The present study clearly indicates that although PBSC harvests collected after consolidation chemotherapy are contaminated by leukaemic cells, the degree of leukaemic contamination may decrease as chemotherapy is repeated. The mobilization of PBSC by repeated chemotherapy may provide an advantageous source of haemopoietic stem cells for ABSCT.

Adolescent↗
PubMed1995

Characterization of blasts from a patient with eosinophilic blast crisis of chronic myelogenous leukaemia.

We investigated the biological characteristics of 'eosinophilic' leukaemic blasts from a patient with eosinophilic blast crisis of chronic myelogenous leukaemia (CML). Southern blot analysis of the bcr gene demonstrated the identical single rearranged band in both the leukaemic blasts and mature eosinophils. IL-3, IL-5 and GM-CSF significantly enhanced proliferation and differentiation of these leukaemic blasts, and only eosinophils were generated from in vitro cultures. Those eosinophils expressed the B3A2 chimaeric messenger RNA seen in the leukaemic blasts. These observations indicate that eosinophil progenitors may be involved in the development of eosinophilic blast crisis of CML and that IL-3, IL-5 and GM-CSF act on the leukaemic eosinophil progenitors.

Blast Crisis↗
PubMed1995

Relationship of infused CFU-GM and CFU-Mk mobilized by chemotherapy with or without G-CSF to platelet recovery after autologous blood stem cell transplantation.

Although hematologic reconstitution is usually rapid after autologous blood stem cell transplantation (ABSCT), there is an occasional delay in platelet recovery. We studied the hematologic recovery of 27 adult patients with hematologic malignancies who received marrow-ablative chemotherapy and ABSCT to determine whether or not the numbers of infused mononuclear cells (MNC), colony-forming units granulocyte/macrophage (CFU-GM), and colony-forming units megakaryocyte (CFU-Mk) were related to the speed of platelet recovery after ABSCT. Peripheral blood stem cells were collected using chemotherapy-induced mobilization with or without cytokine therapy. While the number of MNC infused did not show a significant correlation with time to platelet recovery as well as granulocyte and reticulocyte recovery, the logarithmic number of CFU-GM-infused did (p < 0.01). We also found a significant correlation between the logarithmic number of CFU-Mk-infused and the time to platelet recovery (p < 0.01). These findings suggest that the number of CFU-GM-infused is a reliable indicator of hematopoietic recovery and that the number of CFU-Mk-infused is no more reliable than CFU-GM for predicting platelet recovery after ABSCT.

Adolescent↗
PubMed1994

Single amino acid substitution (58Pro-->Ser) in HTLV-I tax results in loss of ras cooperative focus formation in rat embryo fibroblasts.

Two tax genes cloned from a healthy HTLV-I carrier in whom the viral genome is clonally integrated into peripheral CD4+CD8+ cells showed a considerable difference in ras cooperative focus forming ability in rat embryo fibroblasts (REF). Sequence analysis revealed differences in two codons of the two genes. SH-1tax and SH-2tax. Studies using recombinants between these two tax genes showed that the deficiency in ability of SH-1tax to cooperate with ras in focus formation in REF was caused by a 58Pro-->Ser substitution. This amino acid substitution did not affect other tax functions such as colony formation in soft agar, focus formation in Rat-1 cells, immortalization of REF, and transcriptional activation through the CREB/ATF and NFkB/rel pathways. These results suggest that the domain of tax required for cooperative focus formation with ras in primary rat fibroblasts may be different from those required for other tax functions.

Animals↗
PubMed1994

Cytomegalovirus (CMV) antigenaemia for rapid diagnosis and monitoring of CMV-associated disease after bone marrow transplantation.

A technique for the rapid detection of cytomegalovirus (CMV) antigen-positive blood leucocytes (CMV antigenaemia) was evaluated in 15 marrow transplant patients as a means of diagnosis and for monitoring CMV-associated disease. CMV antigenaemia was determined by direct immunoperoxidase staining of leucocytes with a peroxidase-labelled monoclonal antibody, HRP-C7, which binds an immediate-early antigen of human CMV. CMV antigenaemia occurred in 7/15 marrow transplant patients (47%) and was initially detected between 4 and 6 weeks after transplantation. CMV-associated diseases developed in 3/15 patients (20%). All patients with CMV-associated disease had a relatively large number of CMV antigen-positive leucocytes, exceeding 10 per 50,000 white blood cells (WBCs). In the remaining 12 patients, CMV antigen-positive leucocytes were less than 10 per 50,000 WBCs or were undetectable. CMV-associated disease did not develop in these patients during the period of monitoring. CMV antigen-positive leucocytes were detected more frequently in patients who developed acute graft-versus-host disease (GVHD) or haemorrhagic cystitis than in those without such complications. CMV antigens were detectable from 1 to 4 weeks before the onset of CMV-associated disease which allowed initiation of ganciclovir treatment at an early stage. The degree of CMV antigenaemia paralleled the clinical symptoms and signs, higher degrees of antigenaemia being associated with more significant disease. Thus, the detection of CMV antigen-positive blood leucocytes is useful for the diagnosis and monitoring of CMV-associated disease following bone marrow transplantation.

Acute Disease↗
PubMed1994

Involvement of interferon-gamma and macrophage colony-stimulating factor in pathogenesis of haemophagocytic lymphohistiocytosis in adults.

We investigated the role of monocyte/macrophage-activating cytokines in pathogenesis of haemophagocytic lymphohistiocytosis (HLH) in 21 adult patients. Sera from patients with active HLH contained extremely high levels of macrophage colony-stimulating factor (M-CSF) and of interferon-gamma (IFN-gamma). These levels returned to almost normal during remission. Neither interleukin-4 nor granulocyte/macrophage colony-stimulating factor could be detected. Active HLH sera also contained high concentrations of inflammatory monokines, such as interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-alpha). Serum concentrations of soluble CD8 and soluble interleukin-2 receptor were extremely high during active HLH, and returned to virtually normal levels during remission. Circulating CD2+ T-cells obtained from patients with active HLH spontaneously secreted M-CSF and IFN-gamma in vitro, whereas circulating monocytes did not produce detectable levels of both M-CSF and IFN-gamma, but produced high levels of IL-6 and TNF-alpha. These findings suggest that IFN-gamma and M-CSF at least partly from T-cells, such as CD8+ T-cells, might contribute to activation of monocytes or histiocytes, resulting in the up-regulated monokine production and haemophagocytosis in HLH.

Adolescent↗
PubMed1994

Detection of human herpes virus 6 (HHV 6) in the skin of a patient with primary HHV 6 infection and erythroderma.

Human herpes virus 6 (HHV 6) has been implicated as the causative agent of exanthema subitum in young children. Recently, we reported two cases of a severe, infectious, mononucleosis-like syndrome resulting from a primary HHV 6 infection in immunocompetent adults. Both of these patients had the skin condition generally referred to as "erythroderma". A skin-biopsy specimen from one of them, a 43 year old man, was examined. Using immunohistochemical staining and in situ hybridisation, lymphocytes infected with HHV 6 were found in the skin. It is proposed that the erythroderma in immunocompetent adults infected with primary HHV 6 is provoked by infiltration of infected inflammatory cells or infected neoplastic lymphocytes into the dermis.

Adult↗
PubMed1994

Successful second autologous blood stem cell transplantation after G-CSF-combined conditioning for the treatment of high-risk acute myelogenous leukemia.

We describe a patient with acute myelogenous leukemia (AML) who received his second autologous blood stem cell transplantation (ABSCT) following a G-CSF-combined pre-transplant conditioning regimen. The patient underwent ABSCT during first remission but suffered a relapse 8 months later. After achieving second remission, he was prepared for his second ABSCT; recombinant human granulocyte colony-stimulating factor (rhG-CSF) was administered in combination with Ara C, in addition to the same conditioning regimen as that used before the first ABSCT. There was no increase in regimen-related toxicity after this second G-CSF-combined conditioning regimen when compared with that observed after the first ABSCT. To date, the patient's second remission following the second ABSCT has lasted 26 months, which has exceeded that following the first ABSCT. The G-CSF-combined pretransplant conditioning regimen for ABSCT may be effective in the treatment of high-risk AML by increasing the chemosensitivity of the residual leukemic cells.

Adult↗
PubMed1994

Effects of macrophage colony-stimulating factor (M-CSF) on the mobilization of peripheral blood stem cells.

We studied the effects of human urinary macrophage colony-stimulating factor (huM-CSF) on the mobilization of peripheral blood stem cells (PBSC) following cytotoxic chemotherapy in 6 patients with acute leukemia. After complete remission (CR) was achieved, two courses of consolidation chemotherapy consisting of an intermediate dose of cytosine arabinoside were administered to the patients. During a recovery phase after each course of consolidation chemotherapy, two successive cycles of leukapheresis were performed every other day. M-CSF was administered intravenously at a dose of 8 x 10(6) U/day during a recovery phase after the second course of consolidation chemotherapy (cytotoxic plus M-CSF mobilization). There was no significant difference in white blood cell (WBC) or platelet recovery between the first and second cycles, regardless of the administration of M-CSF. Furthermore, between cytotoxic and cytotoxic/M-CSF mobilization, significant differences were not observed in the harvest of mononuclear cells (average 1.43 x 10(8)/kg vs 1.62 x 10(8)/kg), granulocyte/macrophage progenitor cells (CFU-GM) (1.82 x 10(4)/kg vs 3.07 x 10(4)/kg) or erythroid progenitor cells (BFU-E) (2.86 x 10(4)/kg vs 2.66 x 10(4)/kg). Thus M-CSF is not effective for expanding a pool of circulating hematopoietic stem cells when administered at a conventional dose during hematologic recovery following chemotherapy.

Acute Disease↗
PubMed1993

Hematopoietic progenitor cells from patients with adult T-cell leukemia-lymphoma are not infected with human T-cell leukemia virus type 1.

The in vivo host range of human T-cell leukemia virus type 1 (HTLV-1) has not been definitively established. To determine if hematopoietic stem cells from patients with adult T-cell leukemia-lymphoma (ATL) are infected with HTLV-1, we used a clonogenic progenitor assay followed by the polymerase chain reaction for the detection of HTLV-1 DNA. In vitro growth characteristics of myeloid (CFU-GM) and erythroid (BFU-E) progenitor cells among nonadherent T-cell-depleted bone marrow (BM) mononuclear cells (NA-T-MNCs) from 10 patients with ATL was not significantly different from those of HTLV-1-seronegative controls (P = .20); numbers of colonies per 1 x 10(5) NA-T-MNCs were 34.9 +/- 7.6 for CFU-GM and 39.0 +/- 12.5 for BFU-E in patients with ATL, whereas those were 32.1 +/- 9.5 for CFU-GM and 41.4 +/- 12.7 for BFU-E in normal controls. HTLV-1 DNA was not detected in individual colonies formed by CD34+ cells from any of the patients. Similarly HTLV-1 DNA was not detected in 1 x 10(3) CD34+ cells sorted on a fluorescence-activated cell sorter (FACS) from six patients with ATL studied. In contrast, HTLV-1 DNA was detected in BM mononuclear cells from all patients. These observations clearly indicate that hematopoietic progenitor cells from patients with ATL are normal in their colony-forming capacity and that CD34+ cells from patients with ATL are not infected with HTLV-1 in vivo.

Adult↗
PubMed1993

Group I introns in the liverwort mitochondrial genome: the gene coding for subunit 1 of cytochrome oxidase shares five intron positions with its fungal counterparts.

The complete nucleotide sequence of the mitochondrial DNA (mtDNA) from a liverwort, Marchantia polymorpha, contains thirty-two introns. Twenty-five of these introns possess the characteristic secondary structures and consensus sequences of group II introns. The remaining seven are group I introns, six of which happen to interrupt the gene coding for subunit 1 of cytochrome oxidase (cox1). Interestingly, the insertion sites of one group II and four group I introns in the cox1 gene coincide with those of the respective fungal mitochondrial interns. Moreover, comparison of the four group I introns with their fungal counterparts shows that group I introns inserted at identical genomic sites in different organisms are indeed related to one another, in terms of the peptide sequences generated from the complete or fragmental ORFs encoded by these introns. At the same time, the liverwort introns turned out to be more divergent from their fungal cognates than the latter are from one another. We therefore conclude that vertical transmission from a common ancestor organism is the simplest explanation for the presence of cognate introns in liverwort and fungal mitochondrial genomes.

Amino Acid Sequence↗
PubMed1993

Cotranscriptional expression of mitochondrial genes for subunits of NADH dehydrogenase, nad5, nad4, nad2, in Marchantia polymorpha.

Three genes for the subunits of the NADH dehydrogenase (nad5, nad4, and nad2) are tandemly clustered on the liverwort mitochondrial genome. Their gene products showed high levels of amino acid sequence identity with the corresponding subunits from higher plant mitochondria (82.8-84.4%), and significant levels of identity with those from liverwort chloroplast (32.0-33.5%). Podospora anserina mitochondria (21.4-45.9%), and human mitochondria (18.4-27.9%). In addition, these three subunits from liverwort mitochondria have conserved amino acid residues in their central regions. The gene nad5 is interrupted by a 672 bp group I intron, while genes nad4 and nad2 are interrupted by group II introns of 899 bp and 1418 bp, respectively. Northern blot analysis using exon-intron specific probes indicated that these three genes are transcribed as a single precursor mRNA of 9.6 kb in length and are processed into mature mRNA molecules in liverwort mitochondria. Several regions of this nad gene cluster are repeated in the liverwort mitochondrial genome.

Amino Acid Sequence↗
PubMed1993

A randomized phase II trial of low-dose aclarubicin vs very low-dose cytosine arabinoside for treatment of myelodysplastic syndromes.

We performed a randomized phase II trial comparing low-dose aclarubicin (LC-ACR) with very low-dose cytosine arabinoside (VLD-AC) in 39 consecutive untreated patients with myelodysplastic syndromes (MDS), including refractory anemia (RA), RA with excess of blasts (RAEB) and RAEB in transformation (RAEB-t). Nineteen patients received the VLD-AC therapy; 2 good responses (GR) and 2 partial responses (PR) were obtained in 11 patients with RAEB and RAEB-t, while 2 PR were obtained in 8 RA patients. Eighteen patients received the LD-ACR therapy; 2 GR and 4 PR were obtained in 11 RAEB/RAEB-t patients while 2 PR in 7 RA patients. There was no significant difference in the therapeutic effects and survival between these two groups of patients. These observations suggest that the LD-ACR therapy is effective in some patients with MDS and can be used as an alternative to the low-dose Ara-C therapy.

Aclarubicin↗
PubMed1993

B-lymphoid/myeloid stem cell origin in Ph-positive acute leukemia with myeloid markers.

We report two cases of Philadelphia chromosome (Ph)-positive acute leukemia with definite myeloid markers. Ph was the sole chromosomal abnormality at presentation, and neither eosinophilia, basophilia, thrombocytosis nor hepatosplenomegaly was present. In both cases, Ph+ myeloblasts showed positive stain for myeloperoxidase and naphthol ASD chloroacetate esterase, which fulfilled the FAB criteria of acute myelogenous leukemia (AML). Ph+ myeloblasts co-expressed myeloid and B-lymphoid antigens (CD10, CD13, CD19 and CD33). In case 1, myeloblasts rearranged M-BCR, and the expression of M-BCR/ABL chimeric RNA was demonstrated by using the reverse transcription polymerase chain reaction (RT-PCR). They also clonally rearranged IGH. Ph clone disappeared on cytogenetic analysis in remission, and granulocytes in remission did not have rearranged M-BCR. In case 2, morphocytochemically distinct myeloid and lymphoid blast populations were seen. Myeloblasts and lymphoblasts were enriched > 96% as CD19-/CD33+ and CD19+/CD33- populations, respectively. Both of them possessed the identical rearrangement of IGH and M-BCR, indicating a common leukemic progenitor cell origin. Furthermore, m-BCR/ABL was detected in addition to M-BCR/ABL on RT-PCR. Accordingly, both cases were diagnosed as de novo Ph+ acute leukemia rather than as chronic myelogenous leukemia in blastic crisis. Their mixed B-lymphoid/myeloid characteristics strongly suggest that so-called 'Ph+ AML' is derived from Ph+ myeloid/B-lymphoid stem cells.

Adolescent↗
PubMed1993

Kinetics of circulating haematopoietic progenitors during chemotherapy-induced mobilization with or without granulocyte colony-stimulating factor.

Kinetics of circulating haematopoietic progenitors was analysed during chemotherapy- or chemotherapy plus granulocyte colony-stimulating factor (G-CSF)-induced mobilization of peripheral blood stem cells. Circulating progenitors including colony-forming unit granulocyte/macrophage (CFU-GM), burst forming-unit erythroid (BFU-E) and multilineage colony forming unit (CFU-Mix) were studied serially on alternate days during a recovery phase from chemotherapy for consolidation of complete remission. In 18 patients with acute leukaemia, 27 courses of consolidation chemotherapy were performed with a combination of an intermediate-dose cytosine arabinoside with etoposide (Ara-C/Etop) or mitoxantron (Ara-C/Mit). G-CSF (5 micrograms/kg) was administered during the recovery phase in 6/14 courses with Ara-C/Etop and in 4/13 courses with Ara-C/Mit. G-CSF induced a significant and synchronized increase of circulating CFU-GM, BFU-E and CFU-Mix by more than 4-fold at their peaks. The peak of CFU-GM was significantly correlated with that of both BFU-E and CFU-Mix, irrespective of additional G-CSF mobilization. G-CSF also produced a significant increase of monocytes in a synchronized fashion with an increase of circulating CFU-GM. Interestingly, peripheral blood monocytes spontaneously produced high concentrations of IL-6; a significant correlation was observed between absolute monocyte counts and plasma levels of IL-6 or peak levels of CFU-GM. These observations indicate that the addition of G-CSF to chemotherapy-induced mobilization can facilitate further expansion of a blood progenitor pool during the haematopoietic recovery, probably through the stimulation of monocytes to proliferate and to induce their monokine production such as IL-6. The data also suggest that absolute monocyte counts may be a useful indicator to predict the peak of circulating progenitors for collecting autologous blood stem cells.

Adolescent↗
PubMed1993

Granulocyte colony-stimulating factor (G-CSF)-induced mobilization of circulating haemopoietic stem cells.

We studied the utility of G-CSF for harvesting circulating haematopoietic stem cells in patients with leukaemia or lymphoma based on a comparative study in a single patient. Two successive cycles of leukapheresis following cytotoxic chemotherapy were performed in 22 patients as follows: the first cycle was performed with cytotoxic mobilization in all patients while the second cycle was randomized into two groups: cytotoxic (n = 10) and cytotoxic plus G-CSF (cytotoxic/G-CSF) (n = 12) mobilization. Repetitive cytotoxic mobilization did not alter the yields of mononuclear cells (MNC), myeloid (CFU-GM), and erythroid (BFU-E) progenitors. In contrast, cytotoxic/G-CSF mobilization produced significantly higher yields of MNC (2.6-fold), CFU-GM (5.5-fold), and BFU-E (3.9-fold) than did cytotoxic mobilization alone (P < 0.01). The ratio of CFU-GM to BFU-E was not affected by G-CSF. Furthermore, G-CSF led to an earlier peak of CFU-GM following chemotherapy. G-CSF is thus effective in expanding the pool of circulating haematopoietic progenitors.

Acute Disease↗