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Biomedical subjects

M Tanino

Publications and source records attributed to M Tanino.

At least 37 records · Page 2Linked to original sources

Saikosaponin b2 induces differentiation without growth inhibition in cultured B16 melanoma cells.

Treatment with 5 microM of saikosaponin (SS) b2 for 30 days was found to induce differentiation of B16 melanoma cells, with potentiation of expressions of melanogenesis and tyrosinase. To explore the mechanism of this effect, we observed the cell growth, cell cycle and morphology, and found that SSb2 did not affect any of these parameters. That is, SSb2 induced the differentiation of B16 melanoma cells without growth inhibition or cytotoxicity under conditions of low dose and long-term treatment. Phorbol ester, a protein kinase C (PKC) activator, markedly inhibited the expressions of melanogenesis and tyrosinase in both the control B16 melanoma cells and the long-term treated B16 melanoma cells. Down-regulation of the PKC activity may be involved in the effects of SSb2.

Animals↗

Irsogladine maleate may preserve gastric mucosal hydrophobicity against ethanol in phospholipids independent way in rats.

Irsogladine maleate (IM) has been used as a mucosal protective agent, whose action is partially explained as enhancement of mucosal blood flow, increase of cellular cyclic AMP and facilitation of gap-junctional intercellular communication. Effect of IM on rat gastric mucosal hydrophobicity, one of the mucosal barrier properties, was investigated, in comparison with that of 16,16-dimethyl prostaglandin E2 (dmPGE2). IM alone had no effect on mucosal hydrophobicity and mucosal phospholipids content. dmPGE2 alone did not change mucosal hydrophobicity significantly, but remarkably increased mucosal surface-active phospholipids. Intragastric administration of absolute ethanol significantly decreased gastric mucosal hydrophobicity and mucosal phospholipids content. IM could prevent the decrease in mucosal hydrophobicity by ethanol, maintaining the surface mucus gel layer and mucosal surface phospholipids almost as non-damaged control levels, whereas dmPGE2 also prevented the decrease in mucosal hydrophobicity by ethanol, with the surface epithelium being partially exfoliated and mucosal surface-active phospholipids showing remarkable enhancement. These results suggest that IM may preserve gastric mucosal hydrophobicity against ethanol, not through enhancement of mucosal phospholipids content like prostaglandin, but possibly through its reported stabilization action to the epithelial cell lining, which may preserve the surface epithelium with the mucous gel layer containing surface-active phospholipids, a possible origin of mucosal hydrophobicity.

Animals↗

Isolation of a highly metastatic cell line to lymph node in human oral squamous cell carcinoma by orthotopic implantation in nude mice.

To isolate a variant cell line with increased lymph node metastasising potential from human oral squamous cell carcinoma (SCC) we performed in vivo selection using orthotopic implantation in nude mice. Human oral SCC cells (HSC-3) were injected orthotopically into the tongue of nude mice. After 3 weeks their cervical lymph nodes were excised and the tumour cells metastasised to the lymph nodes were isolated and injected into the tongue of nude mice again, this procedure was performed three times. The resultant cells, designated as HSC-3-M3, metastasised to cervical lymph nodes in 90% of mice, while parental HSC-3 cells metastasised in only 30% of mice after injection into the tongue. HSC-3 and HSC-3-M3 cell lines which have the same origin but different lymphatic metastatic capacities could be a useful model system for studying mechanisms involved in lymph node metastasis of human oral SCC.

Animals↗

Inhibition of metastasis by a dialysable factor in fetal bovine serum in B16 melanoma cells.

Fetal bovine serum (FBS) supplemented to the culture medium inhibited the metastasis of B16BL6 melanoma cells in a dose-dependent manner. This metastasis-inhibiting activity was accompanied by growth-promoting activity, up to the concentration of 10% FBS. However, among the clones isolated from B16BL6 cells, there were clones in which FBS significantly inhibited the metastasis without promoting their growth. Dialysis (cutoff M.W. 8000 Da) removed the metastasis-inhibiting activity but not the growth-promoting activity from FBS. These results indicate that FBS has metastasis-inhibiting activity which is independent of growth-promoting activity, and that the metastasis-inhibiting activity is carried by molecules removed by dialysis.

Animals↗

Mutations of E2F-4 trinucleotide repeats in colorectal cancer with microsatellite instability.

Genetic instability at microsatellites in some colorectal cancer (CRC) have been linked to the defects of human mismatch repair genes, but the targets of these defective genes have been largely unknown. We screened CRC specimens for alteration of E2F-4 gene by analyzing both cDNA and genomic sequences along with replication error (RER+) phenotype. Two out of 20 sporadic CRC patients showed RER+ phenotype. We found tumor-specific copy number alteration in 13 consecutive trinucleotide (CAG) repeats within the coding exon of E2F-4 exclusively in these 2 specimens. Thus, E2F-4 may be a clue of the target gene of defective repair genes in CRC with genetic instability in addition to the TGF-beta type II receptor gene.

Base Sequence↗

Saikosaponin b2-induced apoptosis of cultured B16 melanoma cell line through down-regulation of PKC activity.

Saikosaponin (SS) b2 was found to inhibit the proliferation of B16 melanoma cells. To explore this mechanism, we employed flow cytometry to determine the distribution of DNA content. The cell cycle of B16 melanoma cells was accumulated in the G1 phase followed by induction of apoptosis. This suggests that SSb2-induced proliferation inhibition is caused by G1 phase accumulation and that apoptosis induction is G1-phase-accumulation dependent. Phorbol 12-myristate 13-acetate (PMA), a protein kinase C (PKC) activator, did not interfere with the proliferation and did not induce apoptosis of B16 melanoma cells by itself. However, PMA significantly abolished these effects of SSb2 in including proliferation inhibition and apoptosis induction. Down-regulation of the PKC activity may be involved in the effect of SSb2.

Animals↗

Secretory function of adrenal chromaffin cells cultured on polypyrrole films.

Polypyrrole (PPy) is a conducting polymer and is obtained electrochemically on an electrode such as indium-tin oxide (ITO). In this study, in order to develop a novel cell-culture system which makes it possible to communicate with cultured mammalian cells, bovine adrenal chromaffin cells were cultured on PPy-coated ITO plates for 7 days and the influence of PPy-coating on the cell functions was investigated. Since the chromaffin cells synthesize and secrete catecholamines such as adrenaline and noradrenaline, the amount of synthesized and released catecholamines from the chromaffin cells cultured on PPy-coating and ITO itself were measured. The cells on the PPy-coated ITO plate could be kept in culture, without any significant changes in morphology and in the secretory responsiveness to acetylcholine as compared with those of the cells cultured on collagen. On the contrary, the cells on the ITO plate lost the responsiveness, while the amount of catecholamines synthesized was affected little by both PPy and ITO surfaces. It is suggested that PPy supports the secretory function of the chromaffin cells when they are cultured on it. This paper describes that PPy films are applicable as a polymer-modified electrode which support the cell function without collagen.

Animals↗

Hepatocellular carcinoma complicating biliary cirrhosis caused by biliary atresia: report of a case.

A case of hepatocellular carcinoma complicating biliary cirrhosis caused by biliary atresia is reported. The patient had persistent severe jaundice with hepatosplenomegaly. A liver tumor was suspected because of the elevated serum alpha-fetoprotein and was shown by ultrasonography at 6 years of age. The tumor was treated with percutaneous ethanol injection therapy (PEIT). Nine months after initiation of PEIT, the patient died of massive bleeding from a metastatic tumor.

Biliary Atresia↗

The important role of PKC in controlling polyploidy formation in cultured fibrosarcoma cell line.

Induction of polyploidization by colcemid in cultured fibrosarcoma cells (Meth-A cells) was examined. Activators of protein kinase C (PKC), phorbol 12-myristate 13-acetate (PMA) and ATP, inhibited colcemid-induced polyploidization, but not colcemid-induced cell proliferation cessation. These findings suggest that a down-regulation of PKC activity results in checkpoint "dysfunction" which induces polyploidization and that inhibition of polyploidization induction by PMA and ATP is not a result of the inhibition of colcemid-induced depolymerization of tubulin.

Adenosine Triphosphate↗

Potentiation of K252a, a protein kinase inhibitor-induced polyploidization by cAMP in cultured fibrosarcoma cell line.

We found that K252a, a potent inhibitor of protein kinases (PK), induced DNA re-replication of Meth-A cells, i.e., DNA synthesis at a higher DNA ploidy without undergoing cytokinesis (polyploidization). The K252a-induced polyploidization was inhibited by phorbol 12-myristate 13-acetate (PMA), a protein kinase C (PKC) activator, suggesting that the polyploidization is caused through inhibition of PKC. By contrast, the polyploidization was potentiated by adenosine 3':5'-cyclic monophosphate (cAMP), a cAMP-dependent protein kinase (PKA) activator. These findings suggest that the cAMP-dependent signaling pathway and diacylglycerol (DAG)-dependent signaling pathway play an important role in regulating the induction of polyploidization in Meth-A cells, through a possible "cross-talk" between the two pathways.

Adenosine Triphosphate↗

Involvement of peanut agglutinin-binding sugar chains in experimental metastasis of B16 melanoma cells.

Involvement of PNA (peanut agglutinin)-binding sugar chains in experimental metastasis of B16M4 cells and their metastatic variants (B16F1, B16F10, and B16BL6) was investigated by using ginsenoside Rh2 (Rh2), which increased PNA binding to the cell surface without increasing concanavalin A or wheat germ agglutinin binding. The PNA binding to cell surface increased in parallel with the experimental metastatic ability in Rh2-treated B16M4 cells, and this increase in metastatic ability was suppressed when the cells were treated with PNA before i.v. injection of cells. Concanavalin A and wheat germ agglutinin did not have such inhibitory effects. Increased PNA binding was observed on glycoproteins of M(r) 75,000-85,000, and was suggested to be due to reduced sialylation of PNA-binding sugar chains on these glycoproteins. In Rh2-treated B16F10 and B16BL6 cells, the increase in experimental metastatic ability was also associated with increased PNA binding to cell surface and M(r) 75,000-85,000 glycoproteins. Although the mechanisms of these effects of Rh2 are unknown, these results suggested that the reduced sialylation of PNA-binding sugar chains on M(r) 75,000-85,000 is related to the increased experimental metastatic ability of Rh2-treated B16 melanoma cells.

Animals↗

Isolation and characterization of a low metastatic variant from EL-4 mouse T-lymphoma.

A variant cell line (EL-4ad) which adhered to a tissue culture dish was isolated from highly metastatic EL-4 murine T-lymphoma. The experimental and spontaneous metastatic ability of EL-4ad was lower than that of the EL-4 parent cell line. The cell surface phenotypes of both cell lines were CD2+3+4-8-45+TCR alpha beta+TCR gamma delta-, but the level of CD2 expression of EL-4ad was much lower than that of EL-4. Furthermore, EL-4ad had higher binding ability to fibronectin and expressed more PNA receptors on the cell surface than EL-4. These differences indicated that either the maturation stage of the less metastatic variant was lower than that of the parent cell line or the activation state of the two cell lines differed. EL-4ad showed higher in vitro invasiveness and adhesiveness to liver cells, and these characters were not consistent with the reduced metastatic ability of this variant. Neuraminidase-releasable cell surface sialic acid levels did not differ significantly between the cell lines. Neither cell line was adhesive to laminin, type IV collagen or reconstituted basement membrane. These metastasis-related properties could not explain the decreased metastatic ability of EL-4ad. On the other hand, EL-4ad was more sensitive to NK activity than EL-4 in vivo, and this was thought to be a major cause of its decreased metastatic ability. The molecules or mechanisms involved in the differentiation or activation of T-cells may be responsible for the sensitivity of tumor cells to NK activity.

Animals↗

Intrasplenic pancreatic pseudocyst: a case report.

An intrasplenic pseudocyst associated with the acute relapsing phase of chronic pancreatitis in a 51-year-old woman is reported, with a review of the Japanese literature. The patient was admitted with a complaint of left lateral and back pain. Abdominal US and CT revealed communicating cysts at the pancreatic tail and the subcapsule of the spleen. A repeat US and CT 1 month after admission demonstrated enlargement of the cyst at the pancreatic tail. ERCP revealed a dilated main pancreatic duct without any definite evidence of stenosis, and direct communication with the cyst at the pancreatic tail. Percutaneous cystography revealed that the subcapsular cyst of the spleen, the cyst of the pancreatic tail, and the main pancreatic duct communicated with each other. The cyst contained serous fluid with an amylase content of 57,500 IU/I. Distal pancreatectomy and splenectomy was performed. Histologically, there was a nonepithelial lining on the inner surface of the cysts at the pancreatic tail and the subcapsule of the spleen. Severe chronic inflammatory changes were present in the resected tail of the pancreas. Timely surgical treatment is advocated to reduce the mortality and morbidity associated with complications of intrasplenic pseudocysts.

Alcoholism↗

[A superficial carcinoma arising from a solitary hepatic cyst].

Reported is a rare superficial papillary adenocarcinoma arising from a congenital cyst, along with a survey of pertinent cases in the world literature. A 43-year-old male with a huge hepatic cyst was admitted to hospital for further examination. Since the cystic drainage done for alcoholic fixation was seromucinous initially but later contaminated by bile, an operation was initiated for dome resection and the closure of the biliary communication. At the time of the deroofing, however, small granulomas were found. And those were confirmed as being malignant by frozen section. Thus, an extended right lobectomy was performed for therapy. From its history and nature, this was considered to be a cancer arising in a congenital hepatic cyst.

Adenocarcinoma, Papillary↗

Studies on lymphocyte subsets in thymic tissue and functions of peripheral lymphocytes in patients with tumorous thymus with special reference to myasthenia gravis.

In order to obtain a better understanding of the immunological abnormalities present in myasthenia gravis (MG), which is often accompanied by thymoma or thymic hyperplasia, we investigated lymphocyte subsets and their functions using samples of thymoma or thymic hyperplasia tissues from 11 patients (6 cases with MG), and peripheral blood from 6 patients (4 cases with MG). In most thymic tissues from patients with MG, a maturating tendency of lymphocytes was generally observed. Especially in the medulla of thymic hyperplasia, an entirely peripheral blood type of T-lymphocytes, which were Leu-6- and either Leu-2a+ or 3a + 3b+, were encountered abundantly. Therefore, the presence of abnormal maturation of lymphocytes in the thymus or destruction of the barrier between the thymus and the peripheral blood in MG cases was indicated. In cases without MG, no such tendency was noted. As to the peripheral blood in patients with MG, concanavalin A-induced suppressor cells were significantly decreased (p less than 0.01). All of these changes were considered to be intimately related to the appearance of MG.

Adult↗

[A pathologic review of thymic neoplasms].

Pathology, particularly histology and histogenesis, of thymic neoplasms is reviewed. In this report, thymic neoplasms include thymoma, lymphoma, carcinoid and germ cell tumors (teratoma group) originating from the thymus. Ultrastructures, enzymohistochemistry and immunohistochemistry have increased the knowledge on the relation between the histogenesis, morphology and function of each neoplasm. Recently, various kinds of monoclonal antibodies have easily been available, and the use of them in immunohistochemistry is useful for differentiating the subpopulation of lymphocytes in thymomas. Some interpretations referring to the microenvironment by thymoma cells and developing T lymphocytes are described. We stressed that peanut lectin was useful for identifying cortical thymocytes in paraffin sections, and functions of S-100 protein positive cells in thymomas should be investigated for elucidating one of the questions concerning the microenvironment by thymoma cells.

Adult↗

Malignant fibrous histiocytoma of the lung.

A 75-year-old woman was admitted to a hospital for diagnosis of pulmonary infarction and died during treatment. An autopsy revealed a tumor 5 cm in diameter in the hilus of the left lung, spreading into the posterior mediastinum, and a metastasis was also found in the right lung. Histologically, this tumor consisted of two kinds of cells; one of fibroblast-like cells and the other of histiocyte-like cells, showing a storiform pattern. Furthermore, a positive staining for alpha 1-antitrypsin, but negative for CEA, keratin or S-100 protein was seen. Therefore, it was diagnosed as malignant fibrous histiocytoma (MFH) originating in the hilus of the left lung. In addition, many foci of hemorrhagic infarction due to metastasis and infiltration of the tumor into the pulmonary arteries were observed in the right lung. MFH is one of the rarest primary tumors of the lung.

Aged↗