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Biomedical subjects

Toshiaki Tachibana

Publications and source records attributed to Toshiaki Tachibana.

At least 19 recordsLinked to original sources
PubMed2006

Oxidative stress causes heart failure with impaired mitochondrial respiration.

Elderly people insidiously manifest the symptoms of heart failure, such as dyspnea and/or physical disabilities in an age-dependent manner. Although previous studies suggested that oxidative stress plays a pathological role in the development of heart failure, no direct evidence has been documented so far. In order to investigate the pathological significance of oxidative stress in the heart, we generated heart/muscle-specific manganese superoxide dismutase-deficient mice. The mutant mice developed progressive congestive heart failure with specific molecular defects in mitochondrial respiration. In this paper, we showed for the first time that the oxidative stress caused specific morphological changes of mitochondria, excess formation of superoxide (O(2)(*)(-)), reduction of ATP, and transcriptional alterations of genes associated with heart failure in respect to cardiac contractility. Accordingly, administration of a superoxide dismutase mimetic significantly ameliorated the symptoms. These results implied that O(2)(*)(-) generated in mitochondria played a pivotal role in the development and progression of heart failure. We here present a bona fide model for human cardiac failure with oxidative stress valuable for therapeutic interventions.

Animals↗
PubMed2005

Establishment and characterization of EB virus-free normal B-lymphocyte and interleukin-6-producing poorly differentiated adenocarcinoma cell lines derived from gastric tumor tissue.

We successfully established two cell lines, an adenocarcinoma cell line (designated as HIGS) and Epstein-Barr virus-free normal B-lymphocyte cell line (designated as HIGS-BL), derived from a moderately to poorly differentiated adenocarcinoma of the stomach, and examined their characteristics. The tumor delivered to our laboratory from an operating room was cut into small pieces and cultured on the dishes. HIGS and HIGS-BL were established from each individual dish after the onset of primary culture. Although their culture methods were the same, the HIGS cell line was not established from the dishes growing HIGS-BL cells. In addition, HIGS-BL cells were scarcely observed in the HIGS cell dishes. Because of these factors, we have considered until now that HIGS-BL cells may inhibit the growth of HIGS cells or cause damage to HIGS cells by unknown mechanisms. Injection of HIGS-BL cells, other B-lymphocyte cell lines, or the conditioned media of HIGS-BL cells into nude mice bearing HIGS-grafted tumors was performed individually. When HIGS and HIGS-BL cells were co-cultured in the same dishes, HIGS-BL cells inhibited the proliferation of HIGS cells. The inhibition of grafted tumor growth was confirmed by the injection of not only the HIGS-BL cells but also the B-lymphocytes. Furthermore, this inhibition was only observed when the conditioned medium of B-lymphocytes was injected into the nude mice. These results suggested that the secretory products by general B-lymphocytes (including HIGS-BL) have some ability to inhibit the proliferation of HIGS cells. In addition, susceptibility tests to anti-cancer drugs suggested that HIGS cells were sensitive to CDDP, ADM and MMC, and HIGS-BL cells were sensitive to CDDP. If CDDP was used for chemotherapy in the patient, the drug produced atrophy of HIGS-BL cells. The study about HIGS and HIGS-BL cells reported the necessity for novel therapeutic approaches in oncotherapy.

Adenocarcinoma↗
PubMed2005

Establishment and characterization of human glioblastoma cell line (HUBT-n).

We succeeded in primary culture of 3 in 4 cases of glioblastomas. The long-term passage cultures were not done from the primary cultures of original tumor, but glioblastoma cell line (HUBT-n) was established from a xenograft of nude mouse. This line grew well without interruption for 4 years and was subcultivated over 120 times. The cells were spindle like or round in shape and neoplastic and pleomorphic features contained glial fibrillar acid protein (GFAP) and S-100 protein and grew multilayering without contact inhibition. A bough-shaped long projection was noted from a small cell. One of the characteristics of the HUBT-n cells was existence of well developed intermediate filaments in their cytoplasm. The cells proliferated rapidly, and the population doubling time was about 32 hours. The chromosome number showed a narrow distribution of diploid range. Abnormal constitution was observed in all cells by G-band karyotyping. The culture cells were easily transplanted into the subcutis of nude mouse and produced the tumor resembling the original tumor.

Aged↗
PubMed2005

Establishment and characterization of a human malignant choroids plexus papilloma cell line (HIBCPP).

A cell line designated "HIBSPP" was established from a human malignant choroids plexus papilloma of 29-year-old Japanese woman. This line grew well without interruption for 3 years and was subcultivated over 70 times. The cells were spindle, oval, and polygonal in shape, and neoplastic and pleomorphic features, a jigsaw puzzle-like arrangement, multilayering and forming papillary structures without contact inhibition. The cells proliferated slowly, and the population doubling time was about 69 hours. The chromosome number showed a wide distribution of aneuploidy. The mode was in the hypotetraploid range, and many marker chromosomes were observed. The culture cells were easily transplanted into the subcutis of nude mice and produced the tumor resembling the original tumor.

Adult↗
PubMed2005

Proliferation and tube formation of periodontal endothelial cells.

Angiogenesis is indispensable to guide a regeneration of good periodontal tissue in the wound healing after periodontal surgery. Hepatocyte growth factor is well known for a strong angiogenic factor and it may play important roles in the periodontal tissue during periodontal wound healing. In exploring the promotion of angiogenesis in the periodontal ligament, proliferative and tubulogenic responses of endothelial cells to hepatocyte growth factor and to soluble factors secreted by fibroblasts were investigated. Pavement-shaped cells isolated from a human periodontal ligament were identified as the endothelial cell by their granular immunoreactivity for factor VIII. The proliferation of the endothelial cells was accelerated by the addition of hepatocyte growth factor or fibroblast-conditioned medium, and far more by adding both than either. The endothelial cells seeded on the agar containing both hepatocyte growth factor and fibroblast products formed a dense network in a shorter time than on the agar containing either. The endothelial cells in the dense network took a tube-like structure with lumen and were covered with laminin. These results suggest that hepatocyte growth factor administered into the regenerating periodontal tissue may promote, synergistically with local factors produced by the activated fibroblast, the proliferation and tubulogenesis of the remaining endothelial cells.

Adolescent↗
PubMed2004

Ghrelin directly regulates bone formation.

UNLABELLED: To clarify the role of ghrelin in bone metabolism, we examined the effect of ghrelin in vitro and in vivo. Ghrelin and its receptor, GHS-R1a, were identified in osteoblasts, and ghrelin promoted both proliferation and differentiation. Furthermore, ghrelin increased BMD in rats. Our results show that ghrelin directly affects bone formation. INTRODUCTION: Ghrelin is a gut peptide involved in growth hormone (GH) secretion and energy homeostasis. Recently, it has been reported that the adipocyte-derived hormone leptin, which also regulates energy homeostasis and opposes ghrelin's actions in energy homeostasis, plays a significant role in bone metabolism. This evidence implies that ghrelin may modulate bone metabolism; however, it has not been clarified. To study the role of ghrelin in skeletal integrity, we examined its effects on bone metabolism both in vitro and in vivo. MATERIALS AND METHODS: We measured the expression of ghrelin and growth hormone secretagogue receptor 1a (GHS-R1a) in rat osteoblasts using RT-PCR and immunohistochemistry (IHC). The effect of ghrelin on primary osteoblast-like cell proliferation was examined by recording changes in cell number and the level of DNA synthesis. Osteoblast differentiation markers (Runx2, collagen alpha1 type I [COLI], alkaline phosphatase [ALP], osteocalcin [OCN]) were analyzed using quantitative RT-PCR. We also examined calcium accumulation and ALP activity in osteoblast-like cells induced by ghrelin. Finally, to address the in vivo effects of ghrelin on bone metabolism, we examined the BMD of Sprague-Dawley (SD) rats and genetically GH-deficient, spontaneous dwarf rats (SDR). RESULTS: Ghrelin and GHS-R1a were identified in osteoblast-like cells. Ghrelin significantly increased osteoblast-like cell numbers and DNA synthesis in a dose-dependent manner. The proliferative effects of ghrelin were suppressed by [D-Lys(3)]-GHRP-6, an antagonist of GHS-R1a, in a dose-dependent manner. Furthermore, ghrelin increased the expression of osteoblast differentiation markers, ALP activity, and calcium accumulation in the matrix. Finally, ghrelin definitely increased BMD of both SD rats and SDRs. CONCLUSIONS: These observations show that ghrelin directly stimulates bone formation.

Adipocytes↗
PubMed2004

New method for forming large embryoid bodies using the wall of the culture dish along with an analysis of their structural characteristics.

Early embryonic stem (EES) cells, which were established from 2 cell stage embryos obtained from ddY mice, had similar characteristics as embryonic stem (ES) cells. These cells were maintained in an undifferentiated stage in growth media supplemented with leukemia inhibitory factor (LIF) and were capable of differentiating into triploblastic tissues under various growth factors. It has been known that normal sized embryoid bodies (EBs) are formed by removing LIF. In this study, large EBs gradually formed along the side wall of a culture dish, particularly at the boundary between the air and the growth medium when cells were cultured for a considerable period of time and without subculturing. We call this method the "wall adhesion culture" procedure. The method itself is simple and do not need any instruments except plastic dishes because only the side walls of the dishes were utilized. The mean thickness of the large EBs was about 1.5 mm 3 months after establishing the static culture. Their surface was covered with a monolayer of cells and they contained an eosinophilic cell matrix. By electron microscopy, some characteristic structures was observed, such as intracisternal A particles which were present inside the swelling of the rough endoplasmic reticulum. Since many tissues derived from ES cells are obtained through EBs, it is expected that efficient acquisition of sufficient quantities of these structures using the wall adhesion culture procedure will be a shortcut for using ES cells in regenerative medicine.

Animals↗
PubMed2004

Establishment and characterization of a nerve cell line (NC-HIMT) from HIMT cells derived from a human ovarian immature teratoma with special reference to the induction of neuron differentiation by retinoic acid.

A nerve cell line designated NC-HIMT was established from a HIMT cell line derived from a benign ovarian, three germ layer immature teratoma removed from a 21-year-old Japanese female. The HIMT cells were elongated, ellipsoid or spherical in shape, whose karyotype was on the high side of normal diploidy. Small amounts of retinoic acid enhanced differentiation and maturation of the HIMT cells into nervous tissue, and the NC-HIMT cell line was established by the colony isolating technique when the HIMT cell line was cultured in the presence of retinoic acid-supplemented medium. After establishment, the NC-HIMT cell line was cultured and maintained in retinoic acid-free growth medium. Even though these cells were cultured without retinoic acid, the phenotype of nerve cells remained and the cells were also maintained in a state of high normal diploidy. The nerve cells contacted each other with their long cell projections and formed networks. Immunocytochemical observations using anti-bovine NSE, alpha-internexin, neurofilament 200kD, peripherin and GFAP confirmed that the cells were either nerve cells or glia cells. These results assume that HIMT cells, which were derived from an immature teratoma, have progenitor and/or stem cells which can differentiate into nerve and/or glial cells.

Adult↗
PubMed2004

Biological characteristics of cultured cells derived from various types of human brain tumors.

We placed in culture brain tumors from 45 cases (7 cases of astrocytoma, 2 from oligodendrogliomas, 2 glioblastomas, 2 ependymomas, 13 meningiomas, 6 pituitary adenomas, 5 neurinomas, a malignant lymphoma, a choroid plexus papilloma, and 6 metastatic tumors) and succeeded in making a primary culture from 33, and maintained 17 in vitro over a considerable period of time (greater than three months). In the early period of the primary cultures, the astrocytoma cells had cytoplasmic processes which contacted each other, the oligodendroglioma cells were small and spindle-shaped, the glioblastoma cells were neoplastic with pleopmorphic features and possessed cytoplasmic processes, the ependymoma cells formed a rosette-like cell arrangement, the meningioma cells were spindle- or round-shaped cells and characterized as forming psammoma bodies, the pituitary adenoma cells were round- or oval-shaped cells and produced growth hormone (GH), adenocorticoid tropic hormone (ACTH), prolactin, or other hypophyseal hormones, the choroid plexus papilloma cells were round-or polygonal and showed a papillary cell arrangement, the neurinoma cells were spindle- or fibrous-shaped cells, and the malignant lymphoma cells were round and formed cell aggregates floating in the culture medium.

Adenoma↗
PubMed2004

Establishment and characterization of JHUCS-1 cell line derived from carcinosarcoma of the human uterus.

The cell line designed JHUCS-1 was established from a carcinosarcoma (malignant mixed mesodermal tumor) of the uterus that was surgically removed from a 57-year-old Japanese woman. We carefully examined the histopathology of the original tumor after the cell line was established and noted differentiation into a neuroendocrine carcinoma within the tumor's epithelial components. Immunohistochemical staining of the tumorous tissue that had been heterotransplanted was positive for Leu7. Additionally, secretary granules were observed in the grafted cells as determined by electron microscopy. These results support the existence of neuroendocrine cells within the JHUCS-1 cell line.

Animals↗
PubMed2004

Establishment and characterization of a human ovarian small cell carcinoma, hypercalcemic type, cell line (OS-1) secreting PTH, PthrP and ACTH--special reference to the susceptibility of anti-cancer drugs.

We successfully established a novel cell line (OS-1) derived from human ovarian small cell carcinoma, hypercalcemic type secreted PTH, PTH-rP and ACTH. The OS-1 cell line was established from metastatic focus of uterus. A patient was 25-year-old Japanese woman. The first she received left ovariectomy on April 2002. The histopathological diagnosis was ovarian small cell carcinoma, pT2c, Nx, Mx. Then on June 2003, metastatic focus of uterus was ectomied. A part of the recurrent tumor of uterus was cut into small pieces with razor blades, and dissociated with 0.1% trypsin-0.02% EDTA/ PBS(-) solution at room temperature. The single cells and small cell clusters were seeded into 60mm dishes and cultured in growth medium (GM: DMEM/F12 supplemented with 20% fetal bovine serum and 0.1% non-essential amino acids solution) at 37 degrees C, 4.7% CO2 in humidified air. Medium was exchanged twice a week. The OS-1 cells grew as floating cultures in the dishes. Radioimmunoassay of the conditioned media was revealed that the cultures secreted large amount of PTH, PTHrP and ACTH simultaneously. Susceptibilities of anti-cancer drugs to the OS-1 cells were examined using oxygen electrode meter (Daikin), and the results suggested VLB and TXL were effective, and CDDP, CPT-11, VP-16, VCR, CPA, MMC and CBDCA were not effective. In our knowledge, it is the first report that the cell line secreting PTH, PTHrP and ACTH was successfully established from ovarian small cell carcinoma, hypercalcemic type. We expect that OS-1 cell line contribute to study on the mechanism of ectopic hormone secretion and susceptibility of anti cancer drugs to the small cell carcinoma.

Adrenocorticotropic Hormone↗
PubMed2004

In vitro culture of various typed meningiomas and characterization of a human malignant meningioma cell line (HKBMM).

We placed on culture the 13 cases of meningiomas, succeeded in making a primary culture of 10 cases and maintained 5 cases in vitro over considerable period of time (over three month), and one cell line derived from a malignant meningioma were established. In the early period of the primary culture, meningioma cells were spindle- or round-shaped cells. In the case of psammomatous type, the cultured cells were characterized as forming psammoma bodies. A cell line designated "HKBMM" was established from a human malignant meningioma occurred from frontal lobe. This line grew well without interruption for 5 years and was subcultivated over 120 times. The cells were spindle and fibrous in shape, and neoplastic and pleomorphic features, and multilayering without contact inhibition. The cells proliferated rapidly, and the population doubling time was about 29 hours. The chromosome number showed a wide distribution of aneuploidy. The mode was in the diploid range. The culture cells were easily transplanted into the subcutis of nude mice and produced the tumor resembling the original tumor.

Animals↗
PubMed2004

Relation between polysomnographic measures during nocturnal sleep and a quotient of behavioral development in infants with developmental disabilities.

Polysomnographic features during nocturnal sleep were investigated in 27 infants with developmental disabilities. With the use of a multiple regression analysis, 78% of the variance of a Development Quotient (DQ) measured by a questionnaire on behavioral development for infants was explained by sleep measures. Of 14 sleep measures employed in the study, (1) cumulative awakening time during a nocturnal sleep time, (2) duration of REM stage, and (3) percentage of REM to total sleep time were important in association with the DQ. The findings are consistent with the sleep-cognition hypothesis proposed by Espie, et al.

Child Development↗
PubMed2003

New approach for the establishment of an hepatocyte cell line derived from rat early embryonic stem cells.

A cell line with the characteristics of hepatocytes was established from rat early embryonic stem cells (REES). This cell line was established using a new novel method of Ishiwata et al. from two cell embryos taken from the spontaneous dwarf rat (SDR). The hepatocyte cell line (REES-hep) was instituted from dark red colored tissue in embryos during embryogenesis using REES cell line cultured in the presence of embryotrophic factors. These cell lines were cultured with DMEM/F12 medium supplemented 10% FBS and 1 ng/ml of LIF. They were found to maintain their diploid state, were characterized with 42 normal chromosomes and proliferated to confluence; contact inhibition was also present. These cells produced albumin when cultured using a collagen sponge gel system and reconstructed in a funicular form resembling the cell cords of liver. The cells also produced albumin and bilirubin when transplanted into the spleen of SDR Reconstruction of a REES-hep cell line from early embryonic stem cells should help in treating hepatic insufficient patients. It will be valuable for further research, as an introduction to cell transplantation and application for use in a bio-hybrid typed liver apparatus.

Albumins↗
PubMed2003

The differentiation of early embryonic stem cells into adipocytes-like cells.

An early embryonic stem cell line, EES-6 cells, was established from 2-cell stage embryos of ddY mice. The cells were maintained in an undifferentiated state with D-MEM/F12 medium supplemented with 10% fetal bovine serum (FBS) (GM) and 1 ng of leukemia inhibitory factor (LIF) without any feeder cells. In this study, EES cells were cultured with a medium containing embryotrophic factors (ETFs) which promoted the differentiation of EES cells into white and brown adipocytes-like cells for a period of 5 days. Lipid droplets in brown adipocyte-like cells were stained with Sudan III; however, large lipid-like droplets in white or brown adipocyte-like cells were unstained with either Sudan III or alcian blue. These findings have numerous possibilities for therapeutic use such as regeneration of skin and wound healing.

Adipocytes↗
PubMed2003

Immunocytochemical study of the GH cells in the anterior pituitary gland of human fetus II. Anencephalic fetus.

In order to elucidate the effects of hypothalamic regulation on the morphology of GH cells, light and electron microscopic immunocytochemical examinations were carried out comparing GH cells in the anterior pituitary gland of anencephalic fetus with those of normal fetuses. Three types of GH cells were identified in the anterior pituitary gland of anencephalic fetus as well as in the normal fetus. Type-I is a small, round cell containing a few small secretory granules. Type-III is a large, polygonal cell with numerous large secretory granules. Type-II is a polygonal cell with medium-sized secretory granules. The Type-II GH cell was predominant in both anencephalic and normal fetuses. The most striking difference between anencephalic and normal fetuses was the presence of atypical forms of the Type II cell. These were polygonal cells containing secretory granules, which were either immunopositive or immunonegative to anti-human GH (anti-hGH) serum. Furthermore, two other types of GH cells were identified. The somatomammotroph (SM cell) contained GH and PRL in different granules within the same cell. Also, a different type of the GH cell was noted containing two varieties of secretory granules; one was immunolabeled only with anti-hGH and the other was not immunolabeled to either anti-hGH or anti-human PRL (anti-hPRL). From these results, we suggest that an absence of hypothalamic regulation in the anencehpalic does not seriously modify GH cell morphology but induces an altered GH storage pattern in some of the cells.

Anencephaly↗
PubMed2003

Establishment and characterization of a human malignant mesothelioma cell line (HMMME).

A cell line designated "HMMME" was established from the pleural fluids of a malignant mesothelioma patient. This line grew well without interruption for 12 years and was subcultured over 200 times. The cells were spindle and roundish in shape and displayed a monolayer sheet in an epithelial pavement cell arrangement. They were neoplastic, had pleomorphic features, and easily formed multilayering without contact inhibition. The cell cytoplasm was strongly positive against anti-vimentin, anti-calretinin and anti-pan-keratin, but negative against anti-BerEP4. The cells proliferated rapidly, and the population doubling time was about 42 hours. Their chromosome number showed a wide distribution of aneuploidy with a mode in the diploid range; many marker chromosomes were observed. The cultured cells were easily transplanted into the subcutaneous of nude mice and produced a tumor classified as a malignant mesothelioma.

Animals↗