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Biomedical subjects

M Nagasawa

Publications and source records attributed to M Nagasawa.

At least 19 recordsLinked to original sources
PubMed1992

Cloning and expression of the epsilon 4 subunit of the NMDA receptor channel.

The primary structure of a novel subunit of the mouse NMDA (N-methyl-D-aspartate) receptor channel, designated epsilon 4, has been revealed by cloning and sequencing the cDNA. The epsilon 4 subunit shares high amino acid sequence identity with the epsilon 1, epsilon 2 and epsilon 3 subunits of the mouse NMDA receptor channel, thus constituting the epsilon subfamily of the glutamate receptor channel. Expression from cloned cDNAs of the epsilon 4 subunit together with the zeta 1 subunit in Xenopus oocytes yields functional NMDA receptor channels. The epsilon 4/zeta 1 heteromeric channel exhibits high apparent affinities for agonists and low sensitivities to competitive antagonists. The epsilon 4 subunit is thus distinct in functional properties from the epsilon 1, epsilon 2 and epsilon 3 subunits, and contributes further diversity of the NMDA receptor channel.

Amino Acid Sequence↗
PubMed1992

Use of a carrier for quantitation of a new dihydropyridine calcium antagonist (OPC-13340) in human plasma by highly sensitive gas chromatography with negative-ion chemical ionization mass spectrometry.

A sensitive gas chromatographic-mass spectrometric method for the quantitation of (+/-)-methyl 3-phenyl-2(E)-propenyl 1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5-pyridinedicarboxylate (OPC-13340, I), a new dihydropyridine calcium antagonist with a potent and long-acting antihypertensive and antianginal effect, was developed in order to elucidate its pharmacokinetics. Dihydropyridine calcium antagonist have been usually quantifed by this technique in the negative-ion chemical ionization mode. However, direct application of this method to quantify trace amounts of I in biological fluids completely failed, owing to its adsorption on the column and oxidation of its dihydropyridine ring. Human plasma containing I and (+/-)-[2H3]methyl 3-phenyl-2(E)-propenyl 1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5-pyridinedicarboxylate (II), the internal standard, was extracted with n-hexane-diethyl ether under weakly basic conditions (pH 8). In order to prevent adsorption of the compounds on the column, (+/-)-[2H5]ethyl 3-phenyl-2(E)-propenyl 1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5-pyridinedicarboxylate (III), an analogue of I, was added to the extracts as a carrier. In addition, this carrier was also effective in preventing the oxidation of I. The quantitation limit of I in human plasma by this method was found to be less than 30 pg/ml. Thus, the method is sufficiently sensitive to study the pharmacokinetics of I in humans.

Calcium Channel Blockers↗
PubMed1992

Purification of brush border membrane vesicles from rat renal cortex by size-exclusion chromatography.

Size-exclusion chromatography with controlled pore glass (CPG) was used in the further purification of renal brush border membrane vesicles (BBMV) isolated by the Ca precipitation method. The BBMV obtained had an almost spherical shape and their average diameter was about 95 nm in isotonic solution. The specific activities of alkaline phosphate and leucine aminopeptidase in the BBMV preparation were increased 18- and 17-fold, respectively, over those in the crude homogenate. The uptake of D-glucose by the purified BBMV in the presence of a sodium gradient reached 8.53 nmol/mg protein at 20 s. These results indicate that CPG chromatography is suitable procedure by which to obtain purified renal BBMV of homogenous size and with high specific marker enzyme activity for use in the study of membrane transport.

Animals↗
PubMed1992

Paraganglioma of the posterior mediastinum: value of magnetic resonance imaging.

A case of paraganglioma arising in the posterior mediastinum in a 29-year-old man diagnosed by magnetic resonance imaging is reported. Excision of mediastinal paraganglioma is often hazardous because of its rich vascular supply and tendency to involve surrounding structures. Magnetic resonance imaging is valuable for the preoperative diagnosis of this vascular tumor as well as for determination of its resectability and appropriate surgical procedure.

Adult↗
PubMed1992

A new tetracycline antibiotic with antitumor activity. I. Taxonomy and fermentation of the producing strain, isolation and characterization of SF2575.

A new antitumor antibiotic SF2575 has been isolated from a culture filtrate of Streptomyces sp. SF2575. The molecular formula was determined to be C40H43NO15 by elemental analysis, mass and 13C NMR spectral analyses. The spectral data revealed SF2575 to be a new tetracycline antibiotic. It was active against Gram-positive bacteria and exhibited antitumor activity against P388 leukemia in mice.

Animals↗
PubMed1992

Peroxidase-negative and myelomonocytic antigen-positive acute leukemia.

Between 1983-1988 bone marrow samples obtained from 195 peroxidase-negative leukemia patients were analyzed for their surface antigens. Thirteen of these patients (6.7%) had myelomonocytic-positive and lymphoid-negative antigens. These leukemic cells reacted with CD13 in eight patients, CD33 in seven, CD11 in six and CDw41 in two. In none of these patients did the leukemic cells react with CD1, CD2, CD3, CD4, CD5, CD8, CD10, CD19 or CD20. Leukemic cells from two patients were reactive with CD7. These leukemic cells demonstrated L2 morphology in 11 patients and L1 morphology in one patient. The leukemic cells from the final patient were diagnosed as those of leukemic transformation of myelodysplastic syndrome. Chromosomal abnormality was observed in approximately half of the patients examined (6/10). Cytochemical analysis revealed that the leukemic cells were negative for periodic acid Schiff stain but positive for acid phosphatase. The prognosis of these patients was markedly poor as compared to acute lymphocytic leukemia or typical peroxidase-positive nonlymphocytic leukemia. Complete remission was induced in only 30% of patients and duration of survival was short (4.7 months). This suggests that myelomonocytic antigen-positive peroxidase-negative acute leukemia is a distinct type of leukemia and may require more aggressive therapy to improve survival.

Acid Phosphatase↗
PubMed1992

[Endoscopic endobronchial metastasis].

Although the incidence of endobronchial metastasis in cases of extrathoracic tumors is 2 to 5 percent in autopsy reports, it is about 30 percent according to endoscopic examination (so-called endoscopic endobronchial metastasis). To confirm the nature of endoscopic endobronchial metastasis, we reviewed the records from 1980 to 1990, presuming the primary foci of metastasis. Of the 36 patients with metastatic pulmonary tumor, 6 (16.7%) were diagnosed as having endobronchial metastasis endoscopically. The primary tumors were colonic cancer (2), prostatic cancer (2), cancer of the tongue (1), and renal cell carcinoma (1). The chest X-ray findings were nodular shadow (3), atelectasis (2), and hilar lymphadenopathy with atelectasis (1). Three patients were treated by lobectomy and the others by systemic therapy alone. The presumed primary foci of metastasis were peripheral lung (3), mediastinal lymph node (1), and undetermined (2). The results of the present study suggest that so-called endoscopic endobronchial metastasis does not necessarily imply metastasis to the bronchial wall.

Aged↗
PubMed1992

[Changes of plombage-operations in respiratory surgery].

The first plombage-operation for pulmonary tuberculosis was by Dr. Nagaishi (1947) and Dr. Wilson, who developed the plombage method employing hollow polymethylmethacrylate spheres. Although the method presented a relatively effective option at a time when no effective drugs were available, its use was discontinued because of such complications as lung injury, cavity-perforation, and empyema. Therefore, soft elastic resin materials, such as those used in sponge-plombage and air-plombage, replaced the hard resin materials. Each plombage method is associated with a certain medical historical period, in Japan. Still the "Kinchyu" method was used. However, the complication of chronic empyema with bronchopleural fistula was difficult to treat. A notable recent method is the pedicled omentum plombage method, which is effective in the treatment of patients who have not responded to standard operations. Finally there was surely a clinical significance in each medical historical period.

Adult↗
PubMed1992

Hepatitis virus infection (HBV and HCV) in eleven Japanese hemodialysis units.

To evaluate hepatitis C virus (HCV) and hepatitis B virus (HBV) infection in hemodialysis (HD) units, serum samples from 607 HD patients and 150 staff members at 11 HD units in Japan were collected, and were compared with those from 704 ordinary blood donors as a control. Serum samples subjected to a first generation ELISA for antibody to HCV (anti-C100-3) and were tested by ELISA for HB surface antigen (HBs-Ag), antibody to HBs-Ag, and antibody to HB core antigen (anti-HBc) as HBV markers. We also tested for HCV infection with a second generation ELISA (for antibodies to C22-3, C33c, and C100-3) in 120 HD patients and 30 staff members at 2 selected HD units. Of 607 HD patients, 104 (17%) were positive for anti-C100-3 and 221 (36%) for HBV markers, indicating a much higher prevalence of HCV and HBV infection among HD patients than among ordinary blood donors (0.9% and 18%, respectively). Of 159 patients without a history of blood transfusion, 17 (11%) were positive for anti-C100-3, showing that HCV infection can be acquired without transfusion. The incidence of anti-C100-3 varied from 0% to 53% at different HD units, and HBV markers varied from 17% to 50%. Our study detected a high prevalence of co-infection with HBV and HCV, suggesting that HCV infection may contribute to chronic liver dysfunction in HD patients. Out of 150 staff members, 3 (2%) were positive for anti-C100-3, whereas 25 (17%) were positive for anti-HBc (indicating prior HBV infection).(ABSTRACT TRUNCATED AT 250 WORDS)

Enzyme-Linked Immunosorbent Assay↗
PubMed1992

[A case of mediastinal liposarcoma].

Primary liposarcomas of the mediastinum are rare neoplasms comprising only 0.13-0.75% of mediastinal tumors. We report a case of liposarcoma arising in the right posterior mediastinum. A 74-year-old man without symptoms was admitted to our hospital for evaluation of an abnormal shadow on chest roentgenogram. Computed tomogram (CT) and magnetic resonance (MR) imaging revealed a mediastinal tumor. The tumor was surgically removed, and the diagnosis of well-differentiated liposarcoma was established. MR imaging was superior to CT in evaluation of tumor extent, but not in differential diagnosis as liposarcoma or lipoma.

Aged↗
PubMed1992

[A case of so-called carcinosarcoma of the lung].

A 65-year-old male was admitted to our institute because of bloody sputum. A tumor in right S6 was detected by X-ray, CT and MRI. Bronchoscopic study showed that the right lower bronchus was occluded by the tumor, in which non-epithelial malignant cells were detected. Therefore right bilobectomy was performed. This tumor was a pedunculated endobronchial type measuring 6 x 4 x 3cm. Histologically, the tumor presented carcinomatous (squamous cell carcinoma and adenocarcinoma) and sarcomatous elements. Immunohistologically, many malignant cells were positively stained by vimentin and muscle-actin, which suggested differentiation from muscle components.

Aged↗
PubMed1992

[Therapeutic application of Nd-YAG laser treatment for the chest surgery area].

Laser therapy is now a well-established procedure and an accepted method of treatment in thoracic surgery. Therefore, using Nd-YAG laser (Model Md-50 Y) at hospital, we had discussed for the technique and its indication of laser therapeutic application against chest diseases. The following results were obtained; 1) The first object of endoscopic laser therapy is to keep the normal air-way from tracheobronchial stenosis or its bleeding as fast as possible. 2) As this laser techniques are not only the quick expansion of the residual lung but also relative absence of air-leak and blood loss, they are indicated for open lung biopsy or partial resection of metastatic lung tumors, particularly in patients with poor pulmonary function. 3) In conjunction with standard surgical technique of chest surgery, this laser treatment provides numerous other possibilities which facilitate the achievement of the therapeutic goal of surgical operation on the lungs.

Adult↗
PubMed1991

Antiproliferative and differentiative effects of recombinant interleukin-4 on a granulocyte colony-stimulating factor-dependent myeloblastic leukemic cell line.

The effect of recombinant human interleukin-4 (IL-4) on a granulocyte colony-stimulating factor (G-CSF)-dependent human myeloblastic leukemic cell line, OCI-AML1a, was investigated. IL-4 suppressed the clonogenic cell growth in methylcellulose culture, inhibited the uptake of 3H thymidine in a dose-dependent manner at 5 to 100 U/mL, and consequently suppressed the growth of clonogenic cells in short- and long-term suspension cultures. In addition, IL-4 markedly increased the number of adherent cells. These adherent cells were alpha-naphthyl-butyrate (alpha-NB) esterase-positive and showed macrophage-like appearance, increased expression of CD14, CD11b, CD23, and Ia, and significantly decreased clonogenicity. On the other hand, nonadherent cells growing in suspension showed only slight increase in proportion of alpha-NB esterase-positive or monocyte/macrophage-like cells and increased CD23 expression by an addition of IL-4. The clonogenicity of the nonadherent cells was not significantly influenced by IL-4. By addition of the media conditioned by OCI-AML1a cells in the presence of IL-4, the clonogenic cells growth of OCIAML1a cells was suppressed and adherent cells were markedly increased. The suppressive and differentiative effects on OCI/AML1a cells of the conditioned media and IL-4 itself were almost completely abolished by anti-IL-4 antibody. Furthermore, the neutralizing antibodies against transforming growth factor-beta 2 (TGF-beta 2), tumor necrosis factor-alpha (TNF-alpha), or IL-6 did not influence the effect of recombinant IL-4. Taken together, IL-4 was shown to suppress the growth and induce differentiation toward adherent macrophage-like cells of the G-CSF-dependent myeloblastic cell line. The effect of IL-4 may be direct, and not secondary via inducing production of other cytokines such as TGF-beta, TNF-alpha, or IL-6 by leukemic cells.

Cell Adhesion↗
PubMed1991

Effect of recombinant interleukin 5 on the generation of cytotoxic T cells (CTL).

The effect of recombinant human interleukin 5 (rhIL5) on the generation of CTL was investigated by using autologous EBV-transformed B cells as the target. Exogenous IL5 augmented the CTL generation, and its effect was most active at the concentration of 10 ng/ml, and when added at the late phase of culture in this system. IL5 augmented specific CTL activity rather than MHC nonrestricted CTL activity as detected with K562 and Daudi when compared to that augmented by IL2. IL5 did not increase the expression of p55 or p75 IL2R nor the responsiveness to IL2. Taken together with the finding that IL5 augmented the CTL activity even in the presence of cyclosporin A, the effect of IL5 on the CTL generation seems not to act through the IL2-IL2R system.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1991

A B cell line from a patient with pure red cell aplasia produces an immunoglobulin that suppresses erythropoiesis.

A 4-year-old boy with pure red cell aplasia was investigated. Immunophenotypic analysis of peripheral blood lymphocytes revealed a marked increase of CD20+ cells, which fell from 25.9% in the active stage to 9.7% in remission. The plasma contained a suppressive activity against CFU-e and BFU-e formation by the patient's bone marrow cells, which disappeared when the disease went into remission. Prednisone (2 mg/kg/day) therapy was tried for 5 weeks, but produced no improvement. Subsequently, high-dose gamma-globulin therapy induced complete remission of anemia. A lymphoblastoid B cell line obtained from the patient before therapy produced a factor that suppressed erythropoiesis but not granulopoiesis. The suppressive activity resided in the immunoglobulin fraction and was adsorbed by an anti-immunoglobulin column. These results indicate that expansion of B cells producing an immunoglobulin which suppressed erythropoiesis was involved in the pathogenesis of the disease in this patient.

B-Lymphocytes↗
PubMed1991

Generation and function of gamma delta T cells after allogeneic bone marrow transplantation in humans: comparison in absence or presence of HLA-matched or mismatched thymus.

We have observed two patients who exhibited an exclusive increase of delta TCS1+ subset of gamma delta T cells in the peripheral blood after bone marrow transplantation (BMT). In one case with severe combined immunodeficiency (SCID) who received haploidentical BMT from his father, gamma delta T cells appeared only after thymus transplantation. However, his T cell-mediated immunity remained severely defective despite the generation of T cells of donor origin. In the other case with aplastic anemia, delta TCS1- gamma delta T cells began to increase in the peripheral blood later. This indicates that the thymus is necessary for the generation of gamma delta T cells and that the delta TCS1+ subset is dominant in the early stages of their ontogeny. delta TCS1+ T cell lines were established from both patients, and allo-reactivity was investigated. The cell line from the latter case reacted to recipient cells in a mixed lymphocyte reaction, but did not show cytotoxity to the allogeneic cells including recipient cells. The other cell line, from the former case, did not react to either donor or recipient cells. This indicates that an intact thymus is needed for gamma delta T cells to acquire allo-reactivity. Both cell lines showed MHC non-restricted cytotoxity against NK-sensitive target cells.

Adolescent↗
PubMed1991

Adaptation of low-phosphate diet in renal brush borders of spontaneously hypertensive rats.

A LPD seems to increase the Pi uptake by vesicles of the BBM of the renal cortex. This study was done to find if there was adaptation to a LPD in the BBM vesicles from the superficial or deep cortex in SHR, with WKY rats as control. The fractional excretion of Pi of SHR on the LPD was higher than that of WKY rats (p less than 0.01). The Vmax of Pi uptake in BBM vesicles from superficial cortex of WKY rats on the LPD was greater (p less than 0.05) than in such rats on a diet with a normal level of phosphate. Thus, the adaptation to a LPD was normal in WKY rats. However, in BBM vesicles from the superficial cortex of SHR kidneys, the difference in this Vmax depending on diet was insignificant. In BBM vesicles of the deep cortex of SHR kidneys, this Vmax was higher (p less than 0.01) on the LPD. The apparent Km was not significantly different in different groups or parts of the renal cortex. These results suggest that BBM vesicles in the superficial cortex of SHR kidneys did not adapt to the LPD. The less adaptation in SHR in vivo indicates that there may be a defect in Pi transport in BBM vesicles of the superficial cortex of SHR kidneys.

Adaptation, Physiological↗