PubMed Health⌕ Search

Biomedical subjects

M Ichimaru

Publications and source records attributed to M Ichimaru.

At least 91 records · Page 5Linked to original sources
PubMed1987

Dysmegakaryocytopoiesis in acute leukaemias: its predominance in myelomonocytic (M4) leukaemia and implication for poor response to chemotherapy.

Megakaryocytopoiesis was morphologically investigated in 129 adults with de novo acute leukaemia. Three types were identified: type I (84 cases), no detectable megakaryocytes; type II (32 cases), quantitatively preserved megakaryocytes with normal morphology; type III (13 cases); quantitatively preserved megakaryocytes but with distinct dysplastic changes such as micromegakaryocytes and megakaryocytes with multiple small separated nuclei. Type III was found in M1 (one out of 21 cases), M2 (one out of 20 cases). M4 (eight out of 24 cases), M6 (two out of four cases) and hypoplastic leukaemia (one out of 13 cases). M3 cases were all classified into type I. Most of acute lymphoid leukaemia cases (21 cases) belonged to type II. Among AML cases, the complete remission (CR) rate by intensive chemotherapy with daunorubicin and cytosine arabinoside was significantly lower in type III (11%) than in types I (87%) and II (71%). Among M4 cases, CR rates in type III (14%) was also significantly lower than those in type I (75%) and II (100%). Thus, the present study indicates the importance of recognizing dysmegakaryocytopoiesis in AML for clarification of the heterogeneous biology or pathophysiology of acute leukaemias and formulation of an appropriate therapeutic strategy.

Acute Disease↗
PubMed1987

Transmission of human T cell lymphotropic virus type I by blood transfusion before and after mass screening of sera from seropositive donors.

The human T cell lymphotropic virus type I (HTLV-I) is transmitted by blood transfusions that contain cell components as one of the virus transmission modes. We carried out mass screening of sera from seropositive donors by a gelatin particle agglutination test to prevent the spread of HTLV-I by transfusion. Seroconversion rates were compared before and after screening. The results show a remarkable decrease in the rate of infection from 53.6 to 0.9%. Therefore, it is certain that screening by the agglutination method prevents the spread of HTLV-I transmission in blood transfusions.

Antibodies, Viral↗
PubMed1987

Japanese patients with leukaemia following the use of Thorotrast including a patient with marked chromosomal rearrangements.

It is estimated that 20,000-33,000 persons have been injected with Thorotrast in Japan. By August 1984, 12 patients with leukaemia following the use of Thorotrast have been reported. Their clinical and haematological data indicate that most of the patients were males over 50 years of age and that the most frequent type of leukaemia involved the stem cells common to the granulocytic, erythroid and/or megakaryocytic lines. This assumption was supported by the evidence of marked chromosomal rearrangements in 100% of the cells from the bone marrow in our case. The median latent period from the administration of Thorotrast to the onset of leukaemia in Japan was 35 years, ranging from 16 to 45 years, which indicates that patients who were injected with Thorotrast should be carefully followed up in the future.

Acute Disease↗
PubMed1987

Milk-borne transmission of HTLV-I from carrier mothers to their children.

In order to clarify the natural transmission route of human T-cell leukemia virus type I (HTLV-I) from mother to child, we have followed two groups of children with ages of 1 to 3 years who were nourished either with HTLV-I-infected breast milk, or with non-infected milk from sero-positive, HTLV-I carrier mothers. Tests for the presence of antibody against HTLV-I revealed that 4 of 6 children in the former group developed HTLV-I infection, while only 1 of 14 children in the latter group became infected. The difference in HTLV-I infection rate for the children in the two groups was statistically significant (P less than 0.01 by chi-square). Furthermore, 2 of 4 elder siblings in the former group developed HTLV-I infection, whereas only one of 8 elder siblings in the latter group became infected. The overall rate of HTLV-I infection of breast-fed children born to HTLV-I-carrier mothers was 25% (8/32) by 3 years of age. Five of 6 mothers with HTLV-I-infected cells in the milk also possessed infected cells in their peripheral blood. Conversely 5 of 6 mothers without infected cells in the peripheral blood possessed no infected cells in their breast milk, suggesting that HTLV-I-infected cells in the peripheral blood can enter the breast milk. None of the 8 breast-fed children born to carrier mothers whose peripheral blood and breast milk-borne cells were negative, developed HTLV-I infection, suggesting that HTLV-I transmission from mother to child is dependent upon the number of HTLV-I-infected cells in carrier mothers.

Adult↗
PubMed1987

[Phase I study of a recombinant gamma interferon (S-6810)].

A phase I study of a recombinant gamma interferon (S-6810) was conducted in a cooperative study involving 11 institutions. S-6810 was administered at doses of 2, 4, 8, 12, 32 and 64 X 10(6) U/m2 by one-hour infusion for 5 consecutive days. A total of 40 courses were administered to 31 patients. High fever exceeding 38 degrees C with chills occurred in about 80% of patients. The incidences of other toxicities were fatigue in 50%, gastrointestinal toxicities in 30-40%, and changes in hepatic enzymes and hematologic toxicities in 20-30%. Dose-limiting factors were judged to be hypotension, leukopenia and central nervous toxicity. Maximum tolerated dose was 64 X 10(6) U/m2 and an optimal dose for phase II study was considered to be 6 X 10(6) U/m2 by daily chronic schedule. Blood concentration was highest at the end of infusion, and then decreased rapidly with a biphasic curve. The peak concentrations were elevated by escalation of doses. A partial response was observed in a patient with mycosis fungoides.

Adult↗
PubMed1987

Cytogenetic and cytochemical studies on progenitor cells of primary acquired sideroblastic anemia (PASA): involvement of multipotent myeloid stem cells in PASA clone and mosaicism with normal clone.

By cytogenetic and cytochemical analyses of individual hematopoietic colonies, we investigated clonality in progenitor compartments of primary acquired sideroblastic anemia (PASA). Two of our four subjects had reduced but countable numbers of CFU-E, BFU-E, and GFU-GM in methylcellulose culture. In one patient with cytogenetic abnormality of 47, XX, +8 in 67% of the bone marrow cells, cytogenetic analysis of individual erythroid bursts and granulocyte/macrophage colonies demonstrated two populations with and without 8 trisomy, the trisomy clone being 38% in BFU-E and 50% in CFU-GM. These findings indicate involvement of multipotent stem cells in PASA clone and mosaicism of two distinct populations in erythroid as well as granulocyte/macrophage progenitor compartments, the abnormal PASA clone and probably the normal clones. In another case with no cytogenetic abnormality, repeated iron staining showed that 31% to 40% of CFU-E and 25% to 54% of BFU-E had erythroblasts with heavy iron deposits. An ultrastructural analysis of 25 individual erythroid bursts revealed that 32% had highly dysplastic erythroblasts with marked ferruginous iron accumulation in the mitochondria. The other 68% and 15 normal bursts from a healthy control did not have noticeable dysplastic changes and iron deposits in the mitochondria. This cytochemical/ultrastructural mosaicism seems to be compatible with the cytogenetic mosaicism. However, whether the BFU-E derived from abnormal PASA clone selectively manifest iron accumulation in the mitochondria or whether the PASA clone itself shows variable degrees of abnormal iron metabolism remains to be determined by simultaneous performance of ultrastructural and cytogenetic analysis for single bursts.

Adult↗
PubMed1986

Significance of chromosome 14 anomaly at band 14q11 in Japanese patients with adult T-cell leukemia.

The chromosomes of leukemic blood cells in eight Japanese patients with acute adult T-cell leukemia (ATL) were examined by a direct method or short-term culture method without any mitogens. Six patients showed a chromosome 14 anomaly with a break at band q11-13: inv(14)(q11q32) in two patients, t(11;14)(p13;q13) in one patient, t(14;14)(q11;q32) in addition to del(14)(q11q13) in another, and only del(14)(q11q13) in two patients. Thus, a proximal 14q rearrangement exists in ATL as in other types of T-cell malignancies. Based on these facts, the pathogenesis of ATL is discussed in reference to the literature.

Chromosome Aberrations↗
PubMed1986

Prognostic significance of the morphological dysplastic changes in chronic myelogenous leukemia.

Various morphological dysplastic changes were observed in patients with chronic myelogenous leukemia, especially in the acute crisis. To clarify their significance, we divided 45 patients in the acute crisis into two groups by our scoring system, the dysplastic group and the non-dysplastic group. Five of 25 subjects in the non-dysplastic group entered complete remission. None of 20 subjects in the dysplastic group did so, and the mean survival after the onset of acute crisis is significantly shorter in the dysplastic group than in the non-dysplastic group. Some patients in the dysplastic group had obvious dysplastic changes several months before the acute crisis. These findings suggest that acute crises in some cases may occur with or be preceded by the development of dysplastic clones similar to myelodysplastic syndrome; these patients respond poorly to conventional chemotherapy.

Adult↗