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K Akashi

Publications and source records attributed to K Akashi.

At least 19 recordsLinked to original sources
PubMed1992

Transfer RNA genes in the mitochondrial genome from a liverwort, Marchantia polymorpha: the absence of chloroplast-like tRNAs.

Twenty-nine genes for 27 species of tRNAs were deduced from the complete nucleotide sequence of the mitochondrial genome from a liverwort, Marchantia polymorpha. One to three species of tRNA genes corresponded to each of 20 amino acids including three species for leucine and arginine, two species for serine and glycine, and one for the rest of the amino acids. Interestingly, all tRNA genes were located in the semicircle of the liverwort mitochondrial genome except for the trnY and trnR genes. The region containing these tRNA genes was originally duplicated, and two trnR genes have diverged from each other. On the other hand, trnY and trnfM are present as two identical copies. The G:U and U:N wobbling between the first nucleotide of the anticodon and the third nucleotide of the codon permit the 27 tRNA identified species to translate almost all codons. However, at least two additional tRNA genes, trnl-GAU for AUY codon and trnT-UGU for ACR codon, are required to read all codons used in the liverwort mitochondrial genome. All of the identified tRNA genes are 'native' in liverwort mitochondria, not 'chloroplast-like' tRNAs as are found in the mitochondria of higher plants. This result implies that the tRNA gene transfer from chloroplast to mitochondrial genome in higher plants has occurred after the divergence from bryophytes.

Base Sequence↗
PubMed1992

Gene clusters for ribosomal proteins in the mitochondrial genome of a liverwort, Marchantia polymorpha.

We detected 16 genes for ribosomal proteins in the complete sequence of the mitochondrial DNA from a liverwort, Marchantia polymorpha. The genes formed two major clusters, rps12-rps7 and rps10-rpl2-rps19-rps3-rpl16-rpl5- rps14-rps8- rpl6-rps13-rps11-rps1, very similar in organization to Escherichia coli ribosomal protein operons (str and S10-spc-alpha operons, respectively). In contrast, rps2 and rps4 genes were located separately in the liverwort mitochondrial genome (the latter was part of the alpha operon in E. coli). Furthermore, several ribosomal proteins encoded by the liverwort mitochondrial genome differed substantially in size from their counterparts in E. coli and liverwort chloroplast.

Amino Acid Sequence↗
PubMed1992

Granulocyte colony-stimulating factor receptors on human acute leukemia: biphenotypic leukemic cells possess granulocyte colony-stimulating factor receptors.

Granulocyte colony-stimulating factor (G-CSF) receptors on the gated leukemic blast cells from newly diagnosed patients with acute leukemia or crisis of chronic myelogenous leukemia were investigated using flow cytometric detection. Surface marker analysis and cytochemical studies were conducted simultaneously to characterize the blast cells. Among 24 leukemia cases examined, G-CSF receptor-positive blast cells were detected in all 11 cases of acute myeloblastic leukemia even though the percentage range of positive cells was widely variable. On the other hand, they were not detected on the blast cells from patients with peroxidase-negative acute lymphoblastic leukemia with no myeloid surface antigens. However, G-CSF receptors were demonstrated in significant amounts on blast cells from 5 of 8 cases of peroxidase-negative acute leukemia expressing both myeloid and lymphoid surface antigens (biphenotypic leukemia). The percentage of blast cells positive for G-CSF receptors was significantly smaller in biphenotypic cases [33 +/- 14% (SD)] than in acute myeloblastic leukemia cases [65 +/- 22%] (P less than 0.01). The percentage expression of CD13 antigen by blast cells was significantly related to their percentage positivity for G-CSF receptors (rs = 0.50, P less than 0.05). These findings indicate that the distribution of flow cytometrically detectable G-CSF receptors on leukemic cells possessing myeloid characteristics may be related to the maturation process.

Antigens, CD↗
PubMed1992

Gene organization deduced from the complete sequence of liverwort Marchantia polymorpha mitochondrial DNA. A primitive form of plant mitochondrial genome.

Analysis of the mitochondrial DNA of a liverwort Marchantia polymorpha by electron microscopy and restriction endonuclease mapping indicated that the liverwort mitochondrial genome was a single circular molecule of about 184,400 base-pairs. We have determined the complete sequence of the liverwort mitochondrial DNA and detected 94 possible genes in the sequence of 186,608 base-pairs. These included genes for three species of ribosomal RNA, 29 genes for 27 species of transfer RNA and 30 open reading frames (ORFs) for functionally known proteins (16 ribosomal proteins, 3 subunits of H(+)-ATPase, 3 subunits of cytochrome c oxidase, apocytochrome b protein and 7 subunits of NADH ubiquinone oxidoreductase). Three ORFs showed similarity to ORFs of unknown function in the mitochondrial genomes of other organisms. Furthermore, 29 ORFs were predicted as possible genes by using the index of G + C content in first, second and third letters of codons (42.0 +/- 10.9%, 37.0 +/- 13.2% and 26.4 +/- 9.4%, respectively) obtained from the codon usages of identified liverwort genes. To date, 32 introns belonging to either group I or group II intron have been found in the coding regions of 17 genes including ribosomal RNA genes (rrn18 and rrn26), a transfer RNA gene (trnS) and a pseudogene (psi nad7). RNA editing was apparently lacking in liverwort mitochondria since the nucleotide sequences of the liverwort mitochondrial DNA were well-conserved at the DNA level.

Base Sequence↗
PubMed1992

Folinic acid does not mobilize hemopoietic progenitors following repeated consolidation chemotherapy for acute leukemia.

Folinic acid (FA) has been reported to expand the pool of peripheral blood stem cells (PBSC) after chemotherapy. We evaluated the efficacy of FA for harvesting PBSC following cytotoxic chemotherapy in 4 patients with acute leukemia. After achieving a complete remission (CR), 3 courses of chemotherapy for a consolidation of the CR were administered to the patients. Two successive cycles of leukapheresis were performed during the recovery phase from consolidation chemotherapy, which consisted of an intermediate dose of cytosine arabinoside. For the second cycle of leukapheresis, FA was administered intravenously at a dose of 50 mg/day following consolidation. The yields of either mononuclear cells or burst-forming units-erythroid (BFU-E) were not affected by FA administration. In contrast, the yields of colony-forming units-granulocyte/macrophage (CFU-GM) were significantly decreased in all patients compared to the CFU-GM yields after the first cycle of leukapheresis (P = 0.032). Thus FA is considered not to be effective in expanding the peripheral blood progenitor pool when given in a fashion different from the original report.

Acute Disease↗
PubMed1992

Continuous and simultaneous ultrasound Doppler velocimetry of the internal carotid and vertebral arteries: preliminary observations of cerebral blood flow changes with common carotid compression.

We have developed a new technique for simultaneous assessment of the four cervical cerebral arteries. Using a cervical brace with four freely adjustable Doppler probes attached, we studied four healthy young males and observed their cerebral blood flow changes during common carotid compression. The results indicated various reactivity in these subjects. We observed that carotid compression sometimes affects or stops the ipsilateral vertebral flow according to the intensity and location of compression. Also, the flow of the contralateral internal carotid artery (ICA) and vertebral artery (VA) showed remarkable increases greater than those due to ICA obliteration alone. This indicates the possibility that using only one probe during compression may often result in unknown obliteration of the ipsilateral VAs flow and could also produce other incomplete data. Moreover, with our technique, we would be able to assess the cerebral reserve more precisely and clearly in patients with carotid or vertebral occlusive diseases.

Adult↗
PubMed1992

Biological characteristics of CD7 positive acute myelogenous leukaemia.

We studied the biological characteristics of CD7+ acute myelogenous leukaemia (AML). We diagnosed nine out of 88 consecutive AML cases as CD7+ AML based on myeloperoxidase positivity and surface antigen expression. In eight of these nine cases more than 20% of leukaemic blasts were found to coexpress both CD7 and a myeloid-associated antigen, CD33, by a two-colour flow-cytometric assay, while in the remaining case more than 90% of blasts were positive for CD7 and myeloperoxidase. CD7+ AML was most frequently observed in M1 among AML subtypes according to the FAB classification. An early stage-specific antigen, CD34 was also expressed on leukaemic blasts from eight of these nine cases. Neither the T-cell receptor (TcR)-beta nor the TcR-gamma gene was clonally rearranged in any of the cases. We then studied the proliferative responses to stimulation by various growth factors. Among interleukin-3 (IL-3), granulocyte/macrophage colony-stimulating factor (GM-CSF), and granulocyte-CSF (G-CSF), IL-3 showed the strongest stimulatory effect on DNA synthesis and leukaemic blast colony formation in 8/9 and 6/8 CD7+ AML cases examined, respectively. On the other hand, the strongest stimulatory effect exerted by IL-3 on blast colony formation was observed in only six out of the 33 CD7- AML cases examined. Furthermore, CD7+ AML blasts could proliferate in response to stem cell factor (SCF); SCF alone showed stimulatory effects on blast colony formation (7/8 cases), and in 5/7 SCF-responding cases, stimulatory effects of SCF were more potent than those of IL-3. In addition, SCF enhanced blast colony formation synergistically with IL-3 in four of these seven cases. These data suggest that progenitor cells of CD7+ AML may possess the biological properties characteristic of immature haematopoietic stem cells.

Adolescent↗
PubMed1992

Interstitial 9q deletion in T-lymphoid/myeloid biphenotypic leukaemia.

We report the biological characteristics of leukaemic blasts from two cases of acute leukaemia with an interstitial deletion of the long arm of chromosome 9 (9q-). Case 1 (FAB: M1) showed del(9)(q12q22) as the sole karyotypic anomaly, and case 2 (FAB: M1) presented del(9) (q12q22) in association with trisomy 10. In both cases, leukaemic blasts presented unique cytological features, such as prominent vacuoles on Giemsa staining, or strong localization of myeloperoxidase resembling 'pseudo-Chediak-Higashi' granules. Immunophenotyping of blasts revealed the biphenotypic expression of T-lymphoid/myeloid antigens (CD2, CD7/CD33) in addition to CD34. Neither T-cell receptor beta (TCRB), T-cell receptor gamma (TCRG) nor Ig heavy chain (IGH) genes were clonally rearranged. Furthermore, there was neither rearrangement nor expression of ABL, which is located at 9q34, indicating that the deletion involved bands centrometric to 9q34 did not induce the activation of ABL. DNA synthesis of the blasts was stimulated (stimulation index greater than 2.0) in the presence of interleukin (IL)-3, IL-4, granulocyte colony-stimulating factor or erythropoietin (Epo). IL-3 and IL-4 could also support the in vitro growth of leukaemic blast colonies, and the IL-3- or IL-4-dependent blast colony growth was synergistically enhanced by the addition of IL-6 or Epo. These observations imply that T-lymphoid/myeloid or pluripotent stem cells may be closely involved in the development of 9q- AML.

Adolescent↗
PubMed1992

Cytotoxic drug and cytotoxic drug/G-CSF mobilization of peripheral blood stem cells and their use for autografting.

We analysed 99 courses of leukapheresis after the use of cytotoxic drugs or cytotoxic drugs plus G-CSF (cytotoxic/G-CSF) to mobilize peripheral blood stem cells (PBSC) in 68 patients with hematologic or solid malignancies. Mean yields of granulocyte-macrophage progenitor cells (CFU-GM) with cytotoxic/G-CSF mobilization were significantly higher than those with cytotoxic mobilization (18.6 vs 8.40 x 10(4)/kg). The optimal timing of collection was different between these two mobilizations; the mean number of days to a peak level of circulating CFU-GM after cytotoxic/G-CSF mobilization was less than that after cytotoxic mobilization (24.2 vs 27.7 days). The leukocyte level on the day of peak CFU-GM was significantly higher in cytotoxic/G-CSF mobilization than that in cytotoxic mobilization (mean 12.8 vs 2.7 x 10(9)/l), whereas the platelet level was not different (mean 132 vs 125 x 10(9)/l). Increasing patient age was not a major adverse factor for PBSC collection. Synchronous recovery of both leukocytes and platelets was critical for achieving a high CFU-GM yield in these two mobilizations. Following PBSC autotransplantation, the rate of trilineage hematologic reconstitution showed a significant correlation with the infused dose of CFU-GM, whether they were collected with cytotoxic or cytotoxic/G-CSF mobilization. These results suggest that G-CSF can expand the PBSC pool and that CFU-GM yield after cytotoxic/G-CSF mobilization may predict trilineage hemopoietic reconstitution after ABSCT, as well as cytotoxic mobilization.

Adolescent↗
PubMed1992

[Immunophenotypic analysis in acute leukemia].

Acute leukemias have been classified on French-American-British (FAB) criteria depending on the morphocytochemical features of blasts. Immunophenotyping and clonal rearrangement analysis of lineage-associated genes can decide a frozen stage of the hematopoietic differentiation process in blasts from acute leukemias. B-lineage acute lymphoblastic leukemia (ALL) and T-lineage ALL are systematically classified according to the sequential expression of differentiation-associated antigens. In acute myelogenous leukemia (AML), several new entities are proposed: AML-M0 is an AML without cytologic maturation, in which the myeloid commitment should be demonstrated by myeloperoxidase-positive microgranule on immunohistochemical staining or electron-microscopy, or by positive reaction for CD13 or CD33 antigens. CD7-positive AML is considered to be one of immature subtypes of AML, rather than hybrid leukemia. Thus, immunological studies on blasts enable us to discriminate a subgroup of leukemias, which will perhaps contribute to the improvement of treatment approach.

Acute Disease↗
PubMed1992

[i(17q) appearing in acute phase in Ph1-negative, BCR-negative CML].

A 36-year-old woman was referred to our hospital because of splenomegaly in February 1989. The leukocyte count was 55,500/microliter without hiatus leukemicus. The leukocyte alkaline phosphatase score was low (29). The bone marrow showed myeloid hyperplasia (24.8% myeloblasts) but no dysplastic change. The karyotype of the bone marrow cells was 46, XX and a diagnosis of Ph1 (-) CML was made. Treatment with VCR, 6MP and prednisolone made 7-month duration chronic phase, but the abnormal karyotype.[46, XX, i(17q)] gradually increased to 100% of bone marrow cells. The patient died in June 1990. The evidence that not only a BCR rearrangement but also messages of BCR/ABL fusion gene were negative made us able to differentiate this case from Ph1(-), BCR(+) CML. The addition of an i(17q) results in partial monosomy of 17q (17q13;p53 gene) and partial trisomy of 17q (17q11.2-12;G-CSF gene). We examined the rearrangement of p53 gene and G-CSF-dependent tumor cell growth in vitro, demonstrating one allelic loss of p53 gene and independent cell growth on G-CSF respectively. It is thought that in Ph1 (-), BCR (-) CML as well as in Ph1 (+) CML, an i(17q) is related to the progression but not to the initiation of these leukemias. However the precise mechanism, including p53 gene inactivation by point mutation, is still to be elucidated.

Adult↗
PubMed1991

Effects of interleukin-4 and interleukin-6 on the proliferation of CD34+ and CD34- blasts from acute myelogenous leukemia.

We studied the effects of interleukin-4 (IL-4) and IL-6 on the growth of leukemic blasts from 40 patients with acute myelogenous leukemia (AML). Patients were selected on the basis of negativity for a series of B-cell antigens including CD10 and CD19. Twenty-one cases were CD34-positive (CD34+) (greater than 15% of blasts) and the remaining 19 were CD34-negative (CD34-) (less than 3% of blasts). IL-4 alone (100 U/ml) could stimulate either DNA synthesis (with greater than 2.0 stimulation index) or leukemic blast colony formation in 24 of 40 AML patients. In the presence of other growth factors, IL-4 showed divergent effects on IL-3-, granulocyte-macrophage colony-stimulating factor-, granulocyte colony-stimulating factor-, or erythropoietin-dependent colony formation. These effects of IL-4 were observed in both CD34+ and CD34- AML cases. IL-6 (100 U/mL) alone could not stimulate DNA synthesis and blast colony formation except for one CD34+ case. On the other hand, IL-6 showed synergistic effects on IL-3- and IL-4-dependent blast colony formation in 10 of 12 and 7 of 9 CD34+ AML cases, respectively. Among CD34- AML cases, such synergism was seen only in 1 of 12 cases for IL-3-dependent colony formation and in 3 of 7 cases for IL-4-dependent colony formation. The divergent effect of IL-4 and the synergistic effect of IL-6 were also observed in purified CD34+ leukemic blast populations, indicating that these phenomena are not mediated by accessory cells. The present study suggests that IL-4, alone or in combination with other growth factors, has divergent effects on the growth of AML progenitors irrespective of the CD34 expression, and that IL-6 acts synergistically with IL-3 or IL-4 on the growth of leukemic progenitors preferentially in CD34+ AML.

Adolescent↗
PubMed1991

Simultaneous occurrence of myelomonocytic leukemia and multiple myeloma: involvement of common leukemic progenitors and their developmental abnormality of "lineage infidelity".

We investigated the origin of leukemic progenitors in a case of the simultaneous occurrence of myelomonocytic leukemia and multiple myeloma (IgG-kappa). At presentation, myeloperoxidase and nonspecific esterase-positive myelomonocytic cells had proliferated up to 12.2 x 10(9)/liter in the peripheral blood. Bone marrow cell differentials revealed the coexistence of myelomonocytic cells (30%) and atypical plasmacytoid cells (26%). Myelomonocytic cells in peripheral blood expressed both myeloid antigens (CD11b, CD13, CD14, CD15, CD33) and T/B-lymphoid antigens (CD2, CD4, CD5, CD7, CD10, PCA-1). Bone marrow mononuclear cells (BMMC) could be divided into PCA-1 strongly positive and PCA-1 weakly positive populations, which were considered to represent myeloma cells and myelomonocytic cells, respectively; the former were CD2-positive (CD2+), CD14-, and CD15-, whereas the latter were CD2+, CD14+, and CD15+. Immunohistochemical analysis revealed that, in addition to plasmacytoid cells, a minority of myelomonocytic cells showed a positive reaction for IgG staining, and production of IgG was observed in the culture supernatant of CD14+ myelomonocytic cells in peripheral blood. Southern blot analysis revealed the presence of two identical rearrangement bands of immunoglobulin heavy chain gene in both BMMC containing myeloma cells and myelomonocytic cells and CD14+ myelomonocytic cells in peripheral blood. In a long-term methylcellulose assay, peripheral blood mononuclear cells produced large compact colonies consisting of macrophages and IgG+ plasmacytoid cells (M phi/P colonies), while BMMC produced a different type of colonies consisting of CD14+ myelomonoblasts, macrophages, and IgG+ plasma cells (Mb/M phi/P colonies) in addition to M phi/P colonies. Recloning experiments showed that primary Mb/M phi/P colonies gave rise to both secondary M phi/P and Mb/M phi/P colonies. These observations strongly suggest that common leukemic progenitors provide both myeloma and myelomonocytic leukemia cells, and the mechanism of "lineage infidelity" is probably involved in the development of their "bilineal" differentiation.

Antigens, CD↗
PubMed1991

Colonic motility and transit in health and ulcerative colitis.

Preprandial and postprandial colonic motility and transit (scintigraphy), with respect to the splenic flexure, were studied in 10 patients with ulcerative colitis and in 9 healthy subjects. The healthy subjects had a postprandial increase in intraluminal pressure that was significantly (P less than 0.03) greater in the descending colon than in other regions of the colon. In ulcerative colitis, the pressure was decreased in all regions compared with healthy subjects, with no significant pressure gradient among different regions. In normal subjects, transit was quiescent during fasting; eating stimulated both antegrade and retrograde transit. In ulcerative colitis, transit was variable before as well as after the meal. Both healthy subjects and patients with ulcerative colitis had more rapid emptying from the splenic flexure into the sigmoid than into the transverse colon. More frequent, low-amplitude, postprandial propagating contractions occurred in ulcerative colitis (P less than 0.05) than in healthy subjects. Propagating contractions were always antegrade and caused a rapid movement of the tracer into the sigmoid. In conclusion, ulcerative colitis is characterized by (a) decreased contractility, (b) increased low-amplitude propagating contractions, and (c) variable transit. These disturbances may accentuate the diarrhea in ulcerative colitis.

Adult↗
PubMed1991

Characterization of leukaemic basophil progenitors from chronic myelogenous leukaemia.

We describe the unique characteristics of leukaemic basophils from a patient with chronic myelogenous leukaemia (CML). The leukaemic cells were immature basophil-like blasts and expressed CD4, CD7 and HLA-DR in addition to CD13 and CD33. Both immunoglobulin and T cell receptor genes were retained in germline configurations. Interleukin-1 (IL-1) or granulocyte-macrophage colony-stimulating factor (GM-CSF) as well as IL-3 or IL-4 enhanced the proliferation and differentiation of leukaemic cells and only basophils were generated from in vitro culture. These results suggest that basophil progenitors expressing CD4, CD7 and HLA-DR may be involved in the development of basophilic crisis of CML and that both IL-1 and GM-CSF may act on basophil progenitors as well as IL-3 or IL-4.

Antigens, CD↗