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Biomedical subjects

M Kikuchi

Publications and source records attributed to M Kikuchi.

At least 271 records · Page 15Linked to original sources
PubMed1999

Enhanced insulin-stimulated activation of phosphatidylinositol 3-kinase in the liver of high-fat-fed rats.

Insulin receptor substrate (IRS)-1 and IRS-2, which mediate phosphatidylinositol (PI) 3-kinase activation, play essential roles in insulin-induced translocation of GLUT4 and in glycogen synthesis. In this study, we investigated the process of PI 3-kinase activation via binding with IRS-1 and -2 in liver, muscle, and fat of high-fat-fed rats, a model of insulin-resistant diabetes. In the liver of high-fat-fed rats, insulin increased the PI 3-kinase regulatory subunit p85alpha and the PI 3-kinase activities associated with IRS-1 3.6- and 2.4-fold, and with IRS-2, 4.7- and 3.0-fold, respectively, compared with those in control rats. The tyrosine phosphorylation levels of IRS-1 and IRS-2 were not significantly altered, however. In contrast with the liver, tyrosine phosphorylation levels and associated PI 3-kinase proteins and activities were decreased in the muscle and adipose tissue of high-fat-fed rats. Thus, high-fat feeding appears to cause insulin resistance in the liver by a mechanism different from the impaired PI 3-kinase activation observed in muscle and adipose tissue. Taking into consideration that hepatic PI 3-kinase activation is severely impaired in obese diabetic models such as Zucker fatty rats, it is possible that the mechanism by which a high-fat diet causes insulin resistance is quite different from that associated with obesity and overeating due to abnormality in the leptin system. This is the first report to show increased PI 3-kinase activation by insulin in an insulin-resistant diabetic animal model. These findings may be important for understanding the mechanism of insulin resistance in human NIDDM, since a high-fat diet is considered to be one of the major factors exacerbating insulin insensitivity in humans.

Adipose Tissue↗
PubMed1999

No correlation of plasma cell 1 overexpression with insulin resistance in diabetic rats and 3T3-L1 adipocytes.

Membrane glycoprotein plasma cell 1 (PC-1) has been shown to be increased in type 2 diabetes and involved in insulin resistance through inhibiting the insulin receptor tyrosine kinase, which was demonstrated using cultured breast cancer cells. However, other reports have shown contradictory results in Chinese hamster ovary cells and in vitro kinase assay. Thus, we considered it necessary to investigate the effect of PC-1 using highly insulin-sensitive cells. Here, we used two of the following approaches: 1) investigating PC-1 expression levels in insulin-responsive tissues in rat models of diabetes and 2) overexpressing PC-1 in 3T3-L1 adipocytes. We found that PC-1 was highly expressed in insulin-responsive tissues, such as liver and adipose tissue, in normal rats. However, high-fat feeding or streptozotocin-induced diabetes did not change its expression levels in liver, adipose tissue, and skeletal muscle. Thus, PC-1 expression levels were not associated with high-fat-diet-induced insulin resistance or hyperglycemia. Although PC-1 was increased in adipose tissue in Zucker fatty rats (protein level, by 50%; mRNA level, by 90%), its expression levels in liver and skeletal muscle, tissues that are more responsible for whole body glucose metabolism than adipose tissue, did not significantly differ from those in normal rats. Next, we overexpressed PC-1 in 3T3-L1 adipocytes using an adenovirus transfection system. PC-1 expression was markedly increased to a level 16-fold greater than that in normal human adipose tissue, which is higher than the previously reported levels in diabetic patients. However, insulin-induced tyrosine phosphorylation of the insulin receptor and insulin receptor substrate 1, activation of phosphatidylinositol 3-kinase, and glucose uptake were not affected by PC-1 overexpression. These results strongly suggest that increased PC-1 expression is not causally related to insulin resistance.

3T3 Cells↗
PubMed1999

Intravascular large cell lymphoma: clinicopathological, immuno-histochemical and molecular genetic studies.

Intravascular large cell lymphoma (IVLL) is a rare neoplasm characterized by a proliferation of lymphoma cells within the blood vessels. Its cell origin and clinicopathological characteristics have not been well understood. The study uses 5 male and 4 female patients who were diagnosed as having IVLL from 1978 to 1996. We examined cell lineage and adhesion molecules using immunohistochemical staining and performed a molecular analysis by using polymerase chain reaction (PCR) on the IgH gene, on T-cell receptor chain genes, and the Epstein-Barr virus (EBV) and in situ hybridization on EBV. The immunohistochemical and PCR results disclosed 8 cases of B- cell and one of T-cell lymphoma. Three of four cases whose frozen specimens were available expressed CD5. PCR showed EBV in 7 of 9 cases, although EBV was found by in situ hybridization in only 3 cases. Lymphoma cells express CD11a and CD49d (VLA-4), while endothelial cells expressed CD54 (CD11a ligand) and CD106 (CD49d ligand). Such interaction of these adhesion molecules might contribute to the intravascular proliferation of lymphoma cells. Furthermore, the CD5 expression of lymphoma cells suggests that IVLL most likely originates from a unique subtype of B cells, although their normal counterpart remains uncertain.

Aged↗
PubMed1999

Bone marrow aplasia with prominent atypical plasmacytic proliferation preceding acute lymphoblastic leukemia.

A two-year-old boy presented with pancytopenia. Bone marrow examination revealed an aplastic marrow with prominent immature plasma cell proliferation, which mimicked plasma cell leukemia. Immunohistochemistry, however, revealed a polyclonal population consistent with a reactive process, excluding plasma cell neoplasia. Administration of granulocyte-colony stimulating factor resulted in recovery of normal hematopoiesis with resolution of plasmacytosis. Seven months later, the patient had an elevated white blood cell count and bone marrow findings diagnostic of acute lymphoblastic leukemia. To the best of our knowledge this is the first reported case of bone marrow aplasia with prominent polyclonal plasmacytosis presenting as a prodrome of acute lymphoblastic leukemia in childhood.

Anemia, Aplastic↗
PubMed1999

Clonality of primary pulmonary lymphoproliferative disorders; using in situ hybridization and polymerase chain reaction for immunoglobulin.

Primary pulmonary lymphoproliferative disorders (PLDs) are histologically divided into a neoplastic state of high and low grade malignant lymphoma (ML), and a reactive state of follicular bronchitis/bronchiolitis (FB) and lymphoid interstitial pneumonia (LIP). We reviewed 19 cases with PLDs, including 4 cases each of high and low grade B cell ML, 6 FB cases, and 5 cases of LIP. To clarify the clonality of the proliferating cells, we performed an immunohistochemical examination (IHC), in situ hybridization (ISH) for the immunoglobulin light chain and a polymerase chain reaction (PCR) analysis of the immunoglobulin heavy chain gene using DNA obtained from paraffin sections. In addition, a Southern blot analysis was also performed in 6 cases using fresh materials. In IHC, all ML were positive for L26 (CD20), while the monoclonality of the kappa light chain was observed in only one high grade case. However, using ISH we could detect the clonality in three of four high grade ML cases and in one of four low grade ML cases. In FB and LIP, no clonality of immunoglobulin by ISH was observed. In a PCR analysis for the immunoglobulin heavy chain gene, we could detect one or two prominent bands in all 8 cases of high and low grade ML. On the other hand, in all cases of FB and LIP, we could only detect either an oligoclonal or polyclonal population. In summary, the presence of monoclonality of ISH and/or PCR for the immunoglobulin heavy chain gene were limited in the neoplastic state, but not in the reactive state.

Adult↗
PubMed1999

Antifungal activities of D0870 against fluconazole-resistant Candida albicans.

We compared the in vitro and in vivo antifungal activities of D0870, a new triazole antifungal agent, with those of other antifungal agents against 8 clinical isolates of fluconazole-resistant Candida albicans. Microdilution testing was performed according to National Committee for Clinical Laboratory Standards (NCCLS) document M27-T. Minimal inhibitory concentration of D0870 (<0.004-1.0 micro g/ml) was lower than those of fluconazole (2->64 microEg/ml) and itraconazole (0.031-8.0 microEg/ml). In systemic infection models with C. albicans in normal and immunosuppressed mice, D0870 at 0. 3-30 mg/kg/day for 5 days after infection prolonged survival of the animals and showed the highest efficacy among the triazole antifungal agents. At pH 7 and 37C in Sabouraud dextrose broth (SDB), D0870 inhibited the growth of C. albicans and acted cytocidally against one of the middle-resistant strains. In an in vivo study against this strain, D0870 at 10 mg/kg/day for 5 days after infection significantly reduced kidney colony counts (2850+406-997+537 CFU/kidney, P<0.05) on day 7 after infection in comparison with those of the control mice at 24 h after infection. Plasma concentration of D0870 after a single oral administration at 10 mg/kg maintained a sufficient level for interpretation of in vivo antifungal activities. These results suggest that D0870 has strong antifungal activities against clinical isolates of fluconazole-resistant C. albicans in vitro and in vivo, and that these strong activities are at least partially concerned with the fungicidal action.

Animals↗
PubMed1999

Decreased expression of telomerase-associated RNAs in the proliferation of stem cells in comparison with continuous expression in malignant tumors.

Telomerase, an enzyme associated with cellular immortality, is expressed by malignant tumor and stem cells, especially germ cells. Normal somatic cells, however, usually do not express telomerase. In the malignant tumor, deregulation of telomerase is thought to facilitate tumorigenesis and cellular immortality by providing cancer cells unlimited proliferation capacity. We investigated the relationship between proliferation activity and in situ expression of the telomerase RNA component (human telomerase RNA component, hTERC). In addition, in situ hybridization of the telomerase-associated proteins (telomerase-associated protein 1, TEP1; human telomerase reverse transcriptase, TERT), and MIB-1 immunohistochemistry for proliferation activity were performed, using the malignant tumors of adenocarcinoma, squamous cell carcinoma, and malignant lymphoma, and somatic tissues of testis, endometrium, stomach, skin, and lymph nodes. In the somatic tissues, the stem cells expressed telomerase-associated RNA, but no proliferation activity. When the proliferation activity of the stem cells increased, however, the telomerase-associated expressions decreased. In the malignant tumors, both proliferation activity and expression of the telomerase-associated RNA significantly increased. Deregulation of telomerase, in addition to proliferation activity, is associated with tumorigenesis.

Antigens, Nuclear↗
PubMed1999

Production of a high level of specific IgG4 antibody associated with resistance to albendazole treatment in HLA-DRB1*0901-positive patients with strongyloidiasis.

Strongyloidiasis, a human intestinal infection with Strongyloides stercoralis, is difficult to treat with drugs. The factors influencing this phenomenon remain unclear. To determine the host factors involved in response to treatment, 46 patients with strongyloidiasis were treated with albendazole, followed-up for 1 year, and separated into two groups: cured and non-cured. Serum levels of specific IgA, IgE, IgG, IgG1, and IgG4 antibodies were estimated using S. stercoralis antigen. Significantly higher titers of IgG4 antibody were observed in the non-cured group than in the cured group (P = 0.016). A total of 88 patients were typed for HLA-DRB1 alleles and analyzed for serum levels of antibody. The S. stercoralis-specific IgG4 antibody titers were significantly higher in the HLA-DRB1*0901-positive group than in the negative group (corrected P = 0.044). These results suggest that HLA-DRB1*0901 is a possible genetic marker for resistance to treatment of S. stercoralis that is associated with elevation of S. stercoralis-specific IgG4 antibody titer.

Aged↗
PubMed1999

[Non-SU, insulin secretagogues].

The chemical structures, mechanisms of actions, bioavailabilities, insulinotrophic and hypoglycemic actions, and clinical trials of three novel oral hypoglycemic agents, NN-623, A-4166 and KAD-1229 are overviewed. They are non-SU insulin secretagogues and they induce quicker and shorter hypoglycemia than sulphonylureas do, presumably because they are rapidly absorbed into (Tmax: < 30 min) and excreted from blood (T 1/2: < 60 min). They bind to the SU-receptors and suppress K-ATP channels like sulphonylureas do. They stimulate mainly the initial phase of insulin release and evoke a decrease in postprandial rises in plasma glucose in several animals and humans. Clinical trials demonstrated they are efficacious and safe in the treatment of NIDDM subjects. They are useful as a first choice drug for the early stage of NIDDM.

Cyclohexanes↗
PubMed1999

[Clinical effects of combination therapy with cefozopran and tobramycin for severe infections in patients with hematologic diseases].

We studied clinical effect of a combination therapy with cefozopran (CZOP) and tobramycin (TOB) for infections in 80 patients with hematologic diseases in 15 institutes. Combined doses with CZOP 2 g and TOB 60-90 mg twice a day had been given intravenously. Of the 80 patients, 61 patients (42 with acute leukemia, 10 with malignant lymphoma, 3 with aplastic anemia, 2 with chronic myeloid leukemia, 2 with multiple myeloma, and 2 with myelodysplastic syndrome) were evaluable. Those consisted of 6 patients with septicemia, 49 with suspected septicemia, 3 with pneumonia, and 3 with other infections. Clinical efficacy by the treatment was excellent in 24, good in 17, fair in 9, and poor in 11 patients, and the overall efficacy rate including excellent and good was 67.2%. Microbiologically, 5 of the 6 patients with septicemia (1 coagulase negative Staphylococcus, 2 S. pneumoniae, 1 S. oralis, and 1 E. coli) were responded. The efficacy rate in patients with severe granulocytopenia showing 100/microliter or lesser neutrophil counts during the drug administration was 57.1% (12/21). Side effects and abnormal changes of clinical laboratory findings were observed in 5 patients, and 16 patients, respectively, but most of them were mild. The findings above suggested that the combination therapy with CZOP and TOB is useful as an empiric therapy for severe infections in patients with hematologic diseases.

Adult↗
PubMed1999

Establishment and characterization of a serous papillary adenocarcinoma cell line of the human ovary in a serum-free culture.

In order to clarify the biologic characteristics of serous papillary adenocarcinoma of the human ovary, we tried to establish a continuous cell line using four primary tumor specimens derived from four patients with such tumors. We also evaluated c-myc, MYCN and c-erbB2 gene amplification in the cultured cells, and the xenografts, as well as in these four primary tissue specimens by a Southern blot analysis. One continuous cell line, named as FU-OV-1, was established in a serum-free culture system and this line propagated continuously for 96 serial passages over a 2-year-period in vitro. FU-OV-1 reproduced and still maintained the characteristics of the original tumor. C-myc gene amplification was found in the FU-OV-1 cells, and the xenografts, as well as in only the primary tumor of FU-OV-1 out of the four primary serous papillary adenocarcinomas. However, neither MYCN amplification nor c-erbB2 amplification was observed in any tumor specimens including FU-OV-1 cells. In conclusion, FU-OV-1 is thus considered to be a useful system for studying the biological behavior of serous papillary adenocarcinoma in the human ovary. The results of this study suggest that c-myc gene amplification might thus be associated with the progression of this tumor both in vitro and in vivo.

Adult↗
PubMed1999

[Work expansion and teamwork in the clinical examination department].

Changes in hospital management and examination rooms are needed along with revisions of medical laws and medical fees. Clinical examination engineers should improve hospital management by implementing user service, cost performance and effective use of skills to ensure proper treatment.

Interprofessional Relations↗
PubMed1999

Fas and nicotinic acetylcholine receptor in human myasthenic thymus--immunohistochemical study.

We studied the immunohistochemical localization of Fas and nicotinic acetylcholine receptor (nAChR) in the human thymus with myasthenia gravis (MG). Thymuses were obtained from thirteen patients with MG, (thymic hyperplasia 8; thymoma 5) and six normal controls. Antibodies against Fas, nAChR protein isolated from fetal calf thymus (nAChR-FCT), CD3, CD4, and CD8 were used. In both hyperplastic thymus and controls, Fas antigen was found in medullary epithelial cells especially in those around Hassall's corpuscle, in subcapsular epithelial cells, and partially in the cortex. There were no apparent differences between myasthenic thymus and the controls. In the thymic medulla the anti-nAChR-FCT antibody showed a similar staining pattern to the antibody against Fas. The nAChR and the Fas were suggested to be present in the same cell. Then six thymomas were double immunostained with antibodies against Fas and nAChR-FCT. A part of neoplastic epithelial cells were double positive for both Fas and nAChR. The present results show the first observation on the colocalization of the Fas and nAChR in thymic epithelial cells. These antigens were supposed to work on triggering mechanism of autoimmunity in MG.

Adolescent↗
PubMed1999

CD56+CD7+ stem cell leukemia/lymphoma with D2-Jdelta1 rearrangement.

OBJECT: We describe the characteristics of three patients with CD56+CD7+ stem cell leukemia/lymphoma. METHODS: These blasts were analyzed for morphologic, karyotypic, immunophenotypic, and immunogenotypic features using Southern blot and polymerase chain reaction analysis. MATERIALS: Peripheral blood, bone marrow aspirates, or biopsied mediastinal tumor specimens of three CD56+CD7+ stem cell leukemia/lymphoma patients were investigated. RESULTS: The bone marrow of all patients showed myeloperoxidase (MPO) negative blast cells with basophilic cytoplasm and distinct nucleoli with no azurophilic granules. The blasts of two patients were classified as acute lymphoblastic leukemia (L2). The liver, spleen, and lymph nodes were unaffected in all patients. All had an aggressive clinical course. The blasts were strongly positive for both CD7 and CD56 but negative for other T-lineage associated antigens, including CD1, CD2, surface membrane CD3, cytoplasmic CD3c (2/2), CD4, CD5 and CD8. The additional antigens were recognized as follows: CD19 (1/3 cases) as a B lineage, CD33 (1/3) as a myeloid marker, CD34 (2/3) as a stem cell, CD38 (1/1) and HLA-DR (2/3). When the patients relapsed, the phenotypes changed to blasts positive for CD5, CD10 and CD13 in patient 1, CD5 in patient 2, and CD33 in patient 3. MPO, however, remained negative. Cytogenetic analysis showed no common abnormal karyotype. All had a common D2-Jdelta1 induced by T-cell specific enhancer. Rearrangement of TCR beta and gamma genes occurred in patient 2, and IgH and TCR beta underwent rearrangement in patient 3. CONCLUSION: Although a more comprehensive case analysis is necessary, these data suggest the possibility that the blasts of the present cases come from a common lymphoid precursor (T, NK, and B cell) or from a NKT precursor as the fourth lymphoid lineage.

Acute Disease↗