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Biomedical subjects

Y Mogi

Publications and source records attributed to Y Mogi.

49 records · Page 3Linked to original sources
PubMed1991

[A remarkable effect of K-18 (IgG-melphalan complex) in a case of RAEB with hypoplastic marrow].

A 63-year-old male with refractory anemia with excess of blasts (RAEB) and hypoplastic marrow was treated with K-18 (240 mg/day P.O.). On admission, peripheral blood revealed pancytopenia. Bone marrow specimen revealed severe hypocellularity with 18.9% of the blast cells. Ten months later, the blast cells in the bone marrow decreased to 3.8%, and complete remission (CR) was obtained. CR was eight weeks. Duration of response (CR + PR) continued for about eight months. K-18 is an antitumor agent with minimal side effects, and seems to be effective for RAEB with hypoplastic marrow.

Anemia, Refractory, with Excess of Blasts↗
PubMed1990

The production of transforming growth factor-beta in acute megakaryoblastic leukemia and its possible implications in myelofibrosis.

Acute myelofibrosis is often associated with acute megakaryoblastic leukemia (AMKBL). Although the exact mechanism for the progression of myelofibrosis in AMKBL is unclear, certain humoral factors from megakaryoblastic cells, the precursors of platelets, may be involved in the enhancement of collagen synthesis by bone marrow fibroblasts. The present study, therefore, is an investigation of the possible pathogenic role of transforming growth factor-beta (TGF-beta), known to be a very potent collagen-stimulating factor found in platelets in the myelofibrosis of AMKBL. The results obtained were as follows: (1) Conditioned media from peripheral megakaryoblasts taken from an AMKBL patient and from established megakaryoblast cell lines (MEG-01) had much greater stimulatory effects on collagen synthesis in bone marrow fibroblasts than conditioned media from other leukemic cell types. (2) Based on an assessment of soft agar colony formation, there was greater TGF-beta activity in media that had been conditioned from megakaryoblasts than in media from other leukemic cell types. (3) When compared with other leukemic-cell types, megakaryoblasts showed substantially greater expression of TGF-beta mRNA that was hybridized at 2.5 kb with a TGF-beta cDNA probe, and TGF-beta polypeptides were detected at 13 Kd with anti-TGF-beta antibodies. (4) The addition of the anti-TGF-beta antibody inhibited the stimulatory effects of the megakaryoblast conditioned medium on collagen synthesis in bone marrow fibroblasts. These results clearly suggest that megakaryoblasts produce and secrete an active form of TGF-beta and stimulate collagen synthesis in bone marrow fibroblasts in a paracrine manner.

Animals↗
PubMed1990

Kinetics of internalization and cytotoxicity of transferrin-neocarzinostatin conjugate in human leukemia cell line, K562.

Human serum transferrin was conjugated with an anticancer-active polypeptide, neocarzinostatin, by using N-succinimidyl 1-3-(2-pyridyldithio)propionate. The conjugate consisted of 1.8 mol of neocarzinostatin per 1 mol of transferrin on average and retained cytotoxic activity against human tumor cells. This conjugate was capable of binding to the transferrin receptor of human myelogenous leukemia K562 cells and was internalized by endocytosis. The LD50 values of the conjugate and neocarzinostatin alone in the presence of excess native bovine transferrin were 0.20 microgram/ml and 1.80 micrograms/ml, respectively, suggesting that the effect of the conjugate was greater than that of neocarzinostatin alone. A pulse-chase experiment using 125I-labeled conjugate revealed that 25% of the internalized conjugate was degraded in lysosomes and the rest was recycled back to the cell surface without degradation. About 75% of this conjugate recycled back to the cell surface in 18.3 min (3.4 min for receptor binding and 14.9 min for recycling to the cell surface through the acidosomes), while the rest was delivered from the cell surface to the lysosome in 19.6 min. This phenomenon was confirmed by chasing the radioactivity in subcellular fractions separated by Percoll density gradient centrifugation. Therefore, it was concluded that this conjugate is internalized specifically by transferrin receptors and is at least partly transferred to and accumulated in lysosomal compartments, resulting in the inhibition of cellular DNA synthesis.

Antibiotics, Antineoplastic↗
PubMed1989

[A case of cutaneous T cell lymphoma improved with local administration of tumor necrosis factor].

A 63-aged woman with cutaneous T cell lymphoma successfully treated with local administration of tumor necrosis factor (TNF) was reported. She was admitted to our hospital because of tumors and subcutaneous nodules on her bilateral inner thigh. A pathological study of her skin of right inner thigh showed mononuclear atypical cells with hyperlobulated nuclei. In peripheral blood the same lymphoid cells were found. Immunohistochemical staining of these cells was positive for OKT-3 and OKT-4, but negative for OKT-8. No lymph node swelling and no visceral involvement were detected by a CT scan and a Echography of the chest and the abdomen. A diagnosis of cutaneous T cell lymphoma was made (stage IIb TNM classification). Although the chemotherapy of VEPA and CHOP was done, about 70% (PR) of the bilateral inner thigh tumors were retracted. Owing to the interstitial pneumonia aroused in the period of bone marrow suppression and cardiomyopathy after chemotherapy, we gave up further systemic chemotherapy. And then the local administration of TNF was done and the disappearance of the bilateral inner thigh tumors was obtained. Our therapy with local administration of TNF for CTCL in the first report.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1989

[Blood coagulation and metastasis].

To elucidate the correlation of platelet aggregating activity of tumor cells and their metastatic potentials, we established a highly and a low metastatic clone with a different platelet aggregating activity from murine fibrosarcoma (Meth A). The parental Meth A cell and its low metastatic clone (ML-01) showed a typical platelet aggregation pattern with a certain lag time, while a highly metastatic clone (MH-02) showed a biphasic aggregation with no lag time in which the first reversible aggregation was caused by ADP released from MH-02, since it was eliminated by apyrase treatment. The highly metastatic potential, however, was not solely due to the platelet aggregating activity because the administration of PGI2-analogue TEI-8153A did not completely inhibit their pulmonary metastasis. In fact, MH-02 attached more preferentially to type IV collagen or endothelial cell than ML-01 in vitro. These results suggest that MH-02 exerts its high metastatic property through the mechanisms involving multiple factors such as the increased platelet aggregating potential or enhanced adhesiveness.

Animals↗
PubMed1988

Effect of combined administration of a prostacyclin analogue and adriamycin against the artificial metastasis of Meth A cell.

Antimetastatic effect of a stable prostacyclin analogue (PGI2-TEI8153) in combination use with adriamycin (ADM) was investigated. Meth A cell, which had membrane protein of 18,000 daltons specifically bound to platelets, induced platelet aggregation dose-dependently. This platelet aggregation was totally suppressed by PGI2-TEI8153. PGI2-TEI8153 also suppressed the pulmonary arrest as well as pulmonary metastasis of Meth A cells. Combined use of PGI2-TEI8153 and ADM exerted much less antimetastatic effect than that with PGI2-TEI8153 alone, indicating the counteracting effect of ADM against the PGI2-TEI8153. However, this combination use brought about additive antimetastatic effects with 2-fold reduction of pulmonary nodules compared to that of ADM alone. Consequently, even the anticancer drug itself has a negative influence on metastasis, the combined use of PGI2-TEI8153 with it is promising for the prevention of metastasis.

Animals↗
PubMed1984

[Studies on platelet aggregation induced by human cultured carcinoma cell lines].

Attempts were made to clarify the mechanism of platelet aggregation and to characterize the platelet aggregating material employing established human cancer cell lines. Eleven out of the nineteen human cancer cell lines investigated showed platelet aggregating activity. The existence of divalent cation was required for the platelet aggregation induced by HMV-1 tumor cells. The platelet aggregations induced by tumor cells (HMV-1, PC-10, 3LL) were not suppressed by specific thrombin inhibitor (MD-805). The platelet aggregating activities of tumor cells (HMV-1, M 7609) were diminished by treatment with trypsin but not with collagenase or neuraminidase. Aggregating activity was preserved with a preparation of membrane from these tumor cells, although it was abolished by heating(100 degrees C 15 min) or sonication. By SDS PAGE (autoradiography), membrane proteins with MW of 20,000 daltons which specifically bound to platelets were commonly found in cells with platelet aggregating activity (HMV-1, M 7609), but were absent in platelet non-aggregating cells (HGC-25). It is therefore concluded that platelet aggregation induced by human tumor cells does not require the coexistence of thrombin, but is evoked by direct interaction of platelets with aggregating proteins (MW 20,000 daltons) on the cell membrane.

Arginine↗
PubMed1983

Identification of enzymes that are effective for isolating protoplasts from grass leaves.

Cellulase C(1), cellulase Cx, and xylanase were isolated and purified from a cellulase preparation of Trichoderma viride as enzymes effective in the isolation of protoplasts from oat leaves. Pectin lyase which is specific for methyl-galacturonide linkages was also found to be a useful enzyme for the isolation of protoplasts from the tissues. This suggested that pectic polysaccharides with a high degree of esterification may play an important role in cell walls of Gramineae. It was necessary to use the mixture of cellulase C(1), cellulase Cx, xylanase, and pectin lyase for the rapid isolation of protoplasts, while a small amount of protoplasts could be isolated from oat leaves by cellulase C(1) plus xylanase or cellulase C(1) plus pectin lyase. The mixture of four enzymes also was effective in the isolation of protoplasts from the leaves of wheat, barley, and corn.

Journal Article↗
PubMedDate not supplied

The near-infrared electronic endoscope for diagnosis of esophageal varices.

We developed an electronic endoscope sensitive to light delivered by an infrared laser, which makes it possible to visualize submucosal vessels of the gastrointestinal tract. The system consists of a modified electronic endoscope and an image processing unit. A high output laser diode was chosen as the source of the infrared ray with a wavelength of 815 nm, an output of 200 milliwatts, and a band width of 30 nm. Using this instrument, esophageal varices were classified into three categories: venous dilation, dark spot, and diffuse dark area. The venous dilation and dark spot appearances correlated with early esophageal varices, which were rarely seen with visible light. On the other hand, the diffuse dark area appearance was considered to be a high risk sign of future bleeding. This system is useful not only for the early diagnosis of esophageal varices, but also for the localization of optimal puncture sites and the evaluation of the effect of sclerotherapy.

Adult↗