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Biomedical subjects

M Tomonaga

Publications and source records attributed to M Tomonaga.

At least 361 records · Page 20Linked to original sources
PubMed1987

Isochromosome 17q in a case of myelofibrosis with myeloid metaplasia terminating in blastic transformation.

A case of myelofibrosis with myeloid metaplasia in a 61-year-old female patient is reported. Cytogenetic studies were performed using short-term culture without phytohemagglutinin. A chromosomal aberration of an isochromosome 17q, [i(17q)], was revealed in 88% of the metaphases of peripheral blood cells in the blastic phase. However, all metaphases of bone marrow cells in the chronic phase showed a normal karyotype. Furthermore, i(17q) was also observed in 10% of the metaphases of spleen cells examined 8 months before blastic transformation. In this case, therefore, the cells with i(17q) were associated with an abnormal clone of blastic transformation, with the abnormal clone originating in the spleen with myeloid metaplasia.

Aged↗
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

Focal cervical poliopathy causing juvenile muscular atrophy of distal upper extremity: a pathological study.

A new clinical entity under the name of "juvenile muscular atrophy of unilateral upper extremity" was first described in 1959. Although about 150 cases in Japan, and several additional cases in other countries, have been clinically reported in the literature, the pathology has remained unknown because of the benign course of the disease. The first necropsy findings are reported, obtained from a patient with this disease, who died of lung cancer at the age of 38, 23 years after the onset of the disease. The lesions existed only in the anterior horns of the spinal cord at C5 approximately T1, particularly marked at C7 and C8, showing shrinkage and necrosis, degeneration of various degrees of large and small nerve cells, and mild gliosis. The pathological findings differ from those of reported cases of spinal vascular disorders, but some circulatory insufficiency in the territory of the spinal cord would seem to be suggested, although the underlying aetiology remains unknown.

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↗
PubMed1987

Leukemic blast cell colony formation in semisolid culture with erythropoietin: a case report of acute poorly differentiated erythroid leukemia.

The bone marrow of a patient with acute undifferentiated leukemia developed unique colonies after a 14-day culture in erythropoietin (EPO)-containing methylcellulose. The colonies consisted of 20 to 200 nonhemoglobinized large blast cells. Cytogenetic analysis of single colonies revealed hypotetraploid karyotypes with several marker chromosomes that were identical to those found in directly sampled bone marrow. The concurrently formed erythroid bursts showed only normal karyotypes. No leukemic colony formation was observed in other culture systems with either colony-stimulating activity (CSA) or phytohemagglutinin-stimulated leukocyte-conditioned medium (PHA-LCM). The leukemic colonies exhibited a complete EPO-dose dependency similar to that of the patient's normal BFU-E. Although cytochemical and immunologic marker studies of the bone marrow cells failed to clarify the cell lineage of the leukemic cells with extraordinarily large cell size, ultrastructural study revealed erythroid differentiation such as siderosome formation in the cytoplasm and ferritin particles in the rhophecytosis invaginations. These findings indicate that the patient had poorly differentiated erythroid leukemia and that some of the clonogenic cells might respond to EPO in vitro. Corresponding to this biological feature, the leukemic cells were markedly decreased in number in response to repeated RBC transfusions, and partial remission was obtained. These observations suggest that erythroid leukemia distinct from erythroleukemia (M6) with a myeloblastic component, can develop as a minor entity of human acute leukemia.

Acute Disease↗
PubMed1987

[Effect of tamoxifen on the treatment of pituitary adenomas with bromocriptine].

Administration of 2-Br- alpha-ergocryptine (bromocriptine = CB-154) in combination with an estrogen-receptor blocking agent tamoxifen were performed in two patients with prolactinoma and non-functioning adenoma, respectively. Case 1 was a 50-year-old male with hyperprolactinemia, impaired pituitary function and visual disorders, in whom a large invasive sellar mass lesion was disclosed by CT scans, which extended supra- and parasellarly and extracranially into paranasal sinuses and pterygopalatine fossa on the left side. As the effect of bromocriptine therapy was partial in tumor size reduction and decrease of serum PRL level and it could not be gained further improvement except for the well recovered visual acuity, tamoxifen was used together with bromocriptine resulting further reduction of tumor size and normalization of serum PRL level. Unexpectedly the medication was ceased during and after a couple of bypass surgery for angina pectoris, and it was followed by elevation of serum PRL level and regrowth of the sellar tumor as well as impairment of vision. By tamoxifen therapy the visual acuity showed some improvement, but the serum PRL level and the tumor size remained as before. Then the combination therapy with bromocriptine and tamoxifen was started again. Case 2 was a 38-year-old female with three children, who had secondary amenorrhea, galactorrhea, borderline level of serum PRL with impaired pituitary function and visual disorders. Under the diagnosis of a non-functioning pituitary adenoma with supra-sellar extension, a craniotomy was done and intracapsular partial removal of the tumor was made, revealing a chromophobe adenoma in light microscopy and undifferentiated cell adenoma in electron-micrographs.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMed1986

Degeneration of Betz cells in motor neuron disease. A Golgi study.

A morphological study using a modified Golgi impregnation technique was carried out on Betz cells in the motor area of eight patients with motor neuron disease (MND) and age-matched controls without abnormal neuropathological findings during routine examination. Betz cells were categorized as normal (type I), or those with moderate (type II) or marked (type III) degeneration of dendrites. Types II and III Betz cells tended to be dominant in the cases of MND, whereas type I Betz cells constituted the highest percentage in most of the control cases. The frequently observed morphological alterations of Betz cells in MND were accumulation of lipofuscin, degeneration or loss of dendrites, and reactive astrocytic gliosis around the Betz cell soma. It was suggested that Betz cell changes in MND are not only due to aging but also to evident pathological processes, since the above-mentioned findings were more extensive in the MND cases than in the control cases. Also, the so-called lower motor neuron disease belongs to one basic disease termed "motor neuron disease", because the pathological changes of Betz cells were observed even in cases of spinal progressive muscular atrophy alone or associated with progressive bulbar palsy, which are devoid of pyramidal tract degeneration and signs of upper motor neuron lesion.

Aged↗
PubMed1986

The structure analysis of Hirano bodies by digital processing on electron micrographs.

To clarify the structure of Hirano bodies, electron micrographs of Hirano bodies taken at various tilting angles have been studied by digital image analysis. On the electron micrographs, the beaded filaments of Hirano bodies were turned into a pattern of lattice-like arrays by changing the tilting angles. Based on computer-processed diffraction patterns and filtered images, it is proposed that the filaments of Hirano bodies are helical strands with a pitch of 185 A. A model for the helical strand drawn by microcomputer at various angles of rotation is in accordance with the filtered images of the tilted filaments. Computer simulation also reveals that the helical strands appear to be lattice-like when they are arranged in parallel.

Dementia↗