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Biomedical subjects

A Miwa

Publications and source records attributed to A Miwa.

At least 73 records · Page 4Linked to original sources
PubMed1998

A rare atypical myeloproliferative-disorder-like hemopathy with marked dysplasia, peripheral dominant myeloblast proliferation and extramedullary hematopoiesis was converted into typical acute myeloid leukemia with an interval of complete hematological remission.

We describe a patient with leukocytosis with all the stages of neutrophilic series, peripheral dominant myeloblast proliferation, marked dysplasia of myeloid and erythroid series, and extramedullary hematopoiesis of the lymph nodes. A cytogenetic study of the bone marrow cells showed normal karyotype, and molecular analysis of the leukemic cells showed negative for BCR-ABL by RT-PCR. After chemotherapy, the patient went into complete remission with a normal blood and bone marrow profile with no dysplasia. On relapse, the hematological findings showed a typical bone marrow dominant acute myeloid leukemia, with the leukemic cells having a chromosomal abnormality. The patient exhibited the combined features of myeloproliferative disorder, myelodysplastic syndrome, peripheral dominant myeloblast proliferation (so-called peripheral leukemia) and typical acute myeloid leukemia throughout the clinical course. This is thought to be a rare overlapping disease involving these distinct hematological conditions that do not usually occur in the same patient.

Acute Disease↗
PubMed1998

Tyrosine phosphorylation of proteins in primary human myeloid leukemia cells stimulated by cytokines: analysis of the frequency of phosphorylation, and partial identification and semi-quantification of signaling molecules.

We investigated tyrosine phosphorylation of proteins in primary human leukemia cells stimulated by granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage CSF (GM-CSF), interleukin-3 (IL-3), tumor necrosis factor (TNF), thrombopoietin (TPO) and phorbol myristate acetate (PMA) in 61 patients with acute myeloid leukemia (AML), nine patients with chronic myeloid leukemia (CML) in blastic crisis and four patients in chronic phase, and compared these data of leukemia with those of normal human immature hematopoietic cells. These cytokines and PMA induced tyrosine phosphorylation of proteins in a manner characteristic for each cytokine or PMA in AML cells. G-CSF, GM-CSF and IL-3 frequently phosphorylated p92, p80, p70, p44 and p42. p95 was frequently phosphorylated by G-CSF, and was phosphorylated in one third of the cases by TPO. On the other hand, TNF selectively induced tyrosine phosphorylation of p42, and PMA selectively induced that of p44 and p42. In marked contrast to AML cells, CML cells responded poorly to cytokines with protein tyrosine phosphorylation, and normal human bone marrow mononuclear cells and CD34-positive cells also showed poor response to cytokines. The results of the immunoprecipitation studies showed tyrosine phosphorylation of signal transducers and activators of transcription (Stat) 5 induced by G-CSF, GM-CSF, IL-3 and/or TPO in six cases, that of extracellular signal-regulated kinase (ERK) by GM-CSF in two cases and that of p38 by TNF in three cases. Intracellular amount of Stat5 was markedly increased in AML cells compared with that in CML cells and normal human bone marrow cells. whereas intracellular amount of ERK and p38 was uniformly abundant in both leukemic and normal cells. These results show cytokine-specific and amplified tyrosine phosphorylation of proteins in AML cells and suggest that amplified response might, at least in part, result from the increased amount of signaling molecules such as Stat5.

Acute Disease↗
PubMed1998

Development of novel chitosan derivatives as micellar carriers of taxol.

PURPOSE: To develop an intravenous injectable carrier composed of chitosan derivatives for taxol. METHODS: A chitosan with lauryl groups attached to amino groups to provide the hydrophobic moieties and, carboxymethyl groups attached to hydroxy groups to provide the hydrophilic moieties (N-lauryl-carboxymethyl-chitosan = LCC), was newly synthesized. The solubility of taxol in LCC micelles in aqueous solution was examined. The hemolysis test of LCC and the growth inhibition experiment of taxol-loading micelle using KB cells were also performed as in vitro assay. RESULTS: It was found that LCC solubilized taxol by forming micelles with particle sizes less than 100nm. This particle size was considered effective for passive targeting for tumors. The concentration of taxol in the micellar solution was very high, with a maximum of 2.37mg/mL. This maximum was 1000 times above that in a saturated solution of taxol at pH 7.4. Hemolysis testing as an in vitro assay indicated that LCC was safer than Polysorbate 80 (TO-10M) as intravenous surfactant in terms of induction of membrane damage. As judged by cytostatic activity against KB cells, taxol retained activity even when included in LCC micelles. LCC-entrapped taxol was more effective in cytostatic activity than free taxol in low concentrations. CONCLUSIONS: The results of solubilization capacity examination, hemolysis testing, and cytostatic activity suggest that LCC may be useful as a carrier of taxol.

Animals↗
PubMed1998

Abnormality of very long-chain fatty acids of erythrocyte membrane in alcoholic patients.

Profiles of very long-chain fatty acids were studied in the erythrocyte membrane of five alcoholic patients. We identified three fatty acids as cis-16-pentacosenoic acid (C25:1), cis-17-hexacosenoic acid (C26:1), and hexacosenoic acid (C26:1), and hexacosanoic acid (C26:0) by gas chromatography-mass spectrometry. The ratios of C26:1/C22:0, C26:0/C22:0, C24:1/C22:0, and C24:0/C22:0 were increased. These findings suggest that active oxygen species or free radicals generated by chronic alcohol consumption in alcohol patients interrupt the peroxisomal beta-oxidation of fatty acids, because very long-chain fatty acids are mainly metabolized by the peroxisomal beta-oxidation system. This is the first study showing accumulation of very long-chain fatty acids in the erythrocyte membrane of alcoholic patients.

Alcoholism↗
PubMed1998

Primary prostatic lymphoma of mucosa-associated lymphoid tissue.

We present a case of primary prostatic lymphoma referring to a 57-year-old man, who was admitted with the symptom of bladder outlet obstruction, and had a history of urination difficulty for two years. The symptoms and signs were compatible with a diagnosis of benign prostatic hypertrophy (BPH). The pathology of the specimen obtained from transurethral prostatectomy showed B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) type. The patient has been asymptomatic and under complete remission after completion of chemotherapy consisting of doxorubicin, cyclophosphamide, vincristine and prednisone for 6 cycles.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1998

[Survival in patients with clear cell carcinoma of the ovary].

Thirty-one patients with clear cell ovarian carcinoma who underwent primary surgery and postoperative therapy were retrospectively evaluated. Eighteen patients (58%) had International Federation of Gynecology and Obstetrics (FIGO) stage I disease, 3 patients (9.7%) stage II disease, and 10 patients (32.3%) stage III and IV disease. Patients with stage III and IV disease demonstrated a significantly poor prognosis compared with patients who had stage I or II disease (p < 0.01). No patients with stage III and IV disease survived 5 years. p53 protein expression and proliferative activity (PA) were studied by immunohistochemical methods using p53 molecule and antibodies to PCNA (proliferative cell nuclear antigen). Intranuclear accumulations of p53 product were observed in 15 of 31 (48.4%). On the other hand, 15 of 31 (48.4%) patients stained positively for PCNA (> or = 60% of cancer cells stained positively). Positive p53 staining and highly PA were associated with poor survival. Two patients with stage I a relapsed were positive p53 and highly PA. Accordingly, consolidation chemotherapy is necessary for patients with stage I a who are positive p53 and highly PA. Platinum-based chemotherapy for patients who had minimal residual tumor was effective, but 5 patients who had > or = 2 cm tumor burden were not effective at all. The response rate for platinum-based chemotherapy was 20% (1/5) among p53 positive, in contrast to 66.7% (4/6) among p53 negative patients. So it seems that p53 positive patients are chemoresistant.

Adenocarcinoma, Clear Cell↗
PubMed1998

Clinicopathologic features of neuroendocrine carcinomas of the stomach: appraisal of small cell and large cell variants.

OBJECTIVE: To clarify the clinicopathologic features of neuroendocrine carcinomas (NECs) of the stomach, we reviewed 56 cases of surgically treated gastric carcinomas with a solid growth or with areas containing patterns characteristic for neuroendocrine (NE) tumors. METHODS: Of the 56 cases reviewed, we selected 33 cases of NEC based both on histologic patterns common to NE tumors and on histochemical/immunohistochemical results. RESULTS: The average age of patients with NEC was 69.8 years (range, 44-92 years). The majority of patients were men (male-female ratio, 23:10). The most frequently affected site was the upper third (46%) of the stomach. Grossly, 9 cases of NEC were fungating and 24 were ulcerated. As compared with 23 patients with non-NEC tumors, the patients with NECs had a worse prognosis. Histologically, NECs had a variety of histologic patterns, including solid, organoid, trabecular, pseudoglandular, spindle cell, and rosettelike. Based on both cell size and morphologic features, we subdivided NECs into 2 variants, namely, small cell NEC and large cell NEC. Our series included 12 cases of small cell NEC and 21 cases of large cell NEC. CONCLUSIONS: Compared with small cell NECs, large cell NECs had a higher mitotic count, larger polygonal cells, a lower nuclear-cytoplasmic ratio, coarser nuclear chromatin, and more frequent conspicuous nucleoli. Large cell NEC was an aggressive tumor with a very poor prognosis (median survival time, 15.2 months; 1-year survival rate, 58%), which approached that for small cell NEC.

Adult↗
PubMed1998

[A case of mediastinal teratoma discovered availing of pneumonia].

A 42-year-old woman was admitted to our hospital with hemosputum and an abnormal shadow on chest X-ray. Although her hemosputum disappeared after the treatment of pneumonia, the abnormal shadow was not improved. Chest CT showed a mediastinal mass. She underwent thoracotomy and the tumor, measuring 6 x 5 x 5 cm in size, was resected. Pathological diagnosis was a mature type teratoma with direct invasion to the lung. We have to take mediastinal teratoma into consideration as one of the causes of pneumonia.

Adult↗
PubMed1997

Alpha-pompilidotoxin (alpha-PMTX), a novel neurotoxin from the venom of a solitary wasp, facilitates transmission in the crustacean neuromuscular synapse.

A new neurotoxin, named alpha-pompilidotoxin (alpha-PMTX) has been found in the venom of the solitary wasp Anoplius safnariensis. In the neuromuscular synapse of the lobster walking leg preparation, alpha-PMTX (10-100 micro/M) caused great enhancement of both the excitatory and inhibitory postsynaptic potentials. Recordings of the excitatory post synaptic currents (EPSCs) at the synaptic sites showed that alpha-PMTX reversibly and dose-dependently potentiates EPSCs. Alpha-PMTX may act primarily on the presynaptic membrane but the mode of action of the toxin is clearly different from other known facilitatory neurotoxins, such as alpha-latrotoxin, apamin or charybdotoxin. This novel toxin will serve as a useful tool in the research field of neuroscience.

Animals↗
PubMed1997

Adenovirus-mediated expression of AMPA-type glutamate receptor channels in PC12 cells.

The alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type glutamate receptor channels are expressed ubiquitously in brain neurons and mediate fast excitatory neurotransmission. They are composed of four subunits, GluR1, GluR2, GluR3 and/or GluR4. We constructed recombinant adenoviruses encoding rat AMPA receptor subunit cDNAs, GluR1 (AxCAGluR1) and silently mutated GluR2 (AxCAGluR2X) with modified chicken beta-actin promoter and cytomegalovirus immediate-early enhancer. Using these adenoviral vectors, we transferred the GluR1 and GluR2 genes into PC12 cells that possess no functional AMPA receptor channels. PC12 cells infected with these viruses expressed GluR1 and GluR2 RNAs. Immunoblot analysis indicated that the expressed GluR1 and GluR2 proteins were equivalent to those of the rat brain. Functional expression of the AMPA receptor channels was examined using the whole-cell patch clamp technique. In AxCAGluR1-infected cells, the current-voltage (I-V) relationship of response to kainate, a non-desensitizing agonist of AMPA receptors, exhibited a strong inward rectification, indicating the formation of functional GluR1-homomeric channels. In cells infected with both AxCAGluR1 and AxCAGluR2X, the I-V relationship of kainate responses exhibited an outward rectification, indicating the formation of heteromeric GluR1/R2 channels. Immunocytochemical analysis revealed that the AMPA receptor subunit genes were transferred in more than 95% of the infected PC12 cells.

Adenoviridae↗
PubMed1997

Protein kinase C-independent correlation between P-glycoprotein expression and volume sensitivity of Cl- channel.

The possible correlation between P-glycoprotein (PGP) and volume-sensitive Cl- channel was examined in a pair of cell lines: a subline of the human epidermoid KB cell (KB-3-1) and the corresponding MDR1-transfected cell line (KB-G2). Western blot analysis and indirect immunofluorescence studies indicated that KB-G2, but not KB-3-1, exhibits the PGP expression. Patch-clamp whole-cell recordings showed that osmotic swelling activates Cl- currents not only in PGP-expressing but also in PGP-lacking cells. The amplitude of the maximal current was indistinguishable between both cells. Activation of protein kinase C (PKC) or loading with a PKC inhibitor failed to affect the swelling-induced activation of the Cl- currents in both cells. The relation between whole-cell Cl- currents and cell size measured simultaneously showed that volume sensitivity of the Cl- channel was augmented by the PGP expression irrespective of the activity of PKC on the plasma membrane. A similar increase in volume sensitivity of the Cl- channel was also induced by the expression of the ATP hydrolysis-deficient PGP mutant, K433M. We conclude that P-glycoprotein does not represent the volume-sensitive Cl- channel but that its expression modulates volume sensitivity of the Cl- channel in a manner independent of its ATPase activity or of the protein kinase C activity.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1997

Very long-chain fatty acid pattern in crush syndrome patients in the Kobe earthquake.

Profiles of very long-chain fatty acid were studied in the erythrocyte membrane of healthy controls and four patients with crush syndrome caused by the Great-Hanshin Earthquake. The identities of cis-17-hexacosenoic acid (C26:1) and hexacosanoic acid (C26:0) were verified by gas chromatography-mass spectrometry (GC-MS). The ratios C26:1/C22:0, C26:0/C22:0, C24:1/C22:0, and C20:1/C22:0 also were elevated. These findings suggest that active oxygen species and/or free radicals generated by ischemia-reperfusion in the crush syndrome result in beta-oxidation disorders in peroxisomes.

Adult↗
PubMed1997

Primary leiomyosarcoma arising in the lesser sac: report of a case.

We describe herein a very rare case of leiomyosarcoma arising in the lesser sac. A 58-year-old man with a psychiatric disorder was admitted to our department for the investigation of epigastralgia and nausea which he had been suffering since the previous month. A laparotomy revealed that the abdominal mass, found on physical examination, was a primary lesser omental tumor, histological examinations of which confirmed a diagnosis of leiomyosarcoma. The tumor cells showed a DNA diploid pattern. Leiomyosarcoma of the lesser sac is extremely unusual and it is important that it be distinguished from an extraluminal tumor of the abdomen.

DNA, Neoplasm↗
PubMed1997

Hepatocellular carcinoma presenting as extrahepatic mass on computed tomography.

The authors describe an extremely rare case of extrahepatic hepatocellular carcinoma. The patient was a 70-year-old man who was examined by a local doctor because of abdominal discomfort. Barium meal examination demonstrated a defect occupying the lesser curvature of the stomach from the middle of the corpus to the fornix. On an abdominal computed tomography (CT) scan, the lesion, 10 cm in diameter, touched the lower surface of the caudate lobe of the liver. Under laparotomy, the tumor was found between the caudate lobe of the liver and posterior wall of the gastric corpus. As the tumor appeared to be connected with the caudate lobe by a pedicle, only the tumor was resected. Histological examination showed the tumor to be hepatocellular carcinoma of Edmondson's grade III-IV, pedunculated type.

Aged↗