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Biomedical subjects

Satoshi Otani

Publications and source records attributed to Satoshi Otani.

9 recordsLinked to original sources
PubMed2005

The formation of primordial germ cells from germline cells in spherical embryos derived from the blastodisc of 2-cell embryos in goldfish, Carassius auratus.

The property of primordial germ cells (PGCs) in fragmented goldfish embryos was investigated. When 1- and 2- cell embryos were cut at several perpendicular levels at the animal-vegetal axis, cells expressing vas mRNA were observed in the resultant embryos derived from all kinds of animal fragments. Blastodisc fragments from the 1- to 2-cell stage developed to spherical embryos containing yolk body with a yolk syncytial layer (YSL). Germ ring and no tail expression were not observed in the spherical embryo. When the spherical embryo labeled with tracer dye or GFP-nos1 3'UTR mRNA was transplanted onto the animal part of the blastoderm in a host embryo at the blastula stage, PGCs of spherical embryo origin were detected around the gonadal ridges in the resultant embryos which developed normally. These results suggest that small animal fragments should contain factors sufficient for PGC differentiation and that PGCs differentiate without mesoderm induction, since mesoderm is not induced in a spherical embryo.

Animals↗
PubMed2005

Low serum ferritin levels as a clue to colonic cancer detection in two patients with coronary artery disease: a case report.

We diagnosed colonic cancer using low serum ferritin levels as a clue in two patients with cardiac or cardiopulmonary disease. In the course of the follow-up, the serum ferritin levels decreased to less than 18 ng/mL without significant appearance of iron-deficiency anemia. One patient showed positive immunological fecal occult blood test results whereas the other not. Both patients rejected further colonoscopy because of their concern for stress in relation to their cardiac or cardiopulmonary diseases, but instead agreed to positron emission computed tomography (PET) using a F-18 deoxyglucose at their own expense. In both patients, PET documented abnormal tracer accumulation in the colon. From the results of PET imaging, they eventually agreed to colonoscopy. A colonic adenocarcinoma was detected at the site of the positive PET finding in each patient. Both patients underwent curative resection of the cancer. The detection of the levels of serum ferritin may be available for the screening colonic cancer in patients declining colonoscopic examination.

Adenocarcinoma↗
PubMed2004

The germ line lineage in ukigori, Gymnogobius species (Teleostei: Gobiidae) during embryonic development.

In order to determine the origin and migration of ukigori primordial germ cells (PGCs), we observed the aggregation of vasa mRNA by whole mount in situ hybridization. To observe PGC migration in the germ layers, we analyzed HE-stained paraffin sections. The germ line lineages were derived from the edge of the first, second and third cleavage furrows. During subsequent cleavages, vasa mRNA aggregations were respectively taken into four to eight cells in each embryo and vasa expressing cells proliferated from the sphere stage. At the bud to early somitogenesis period, PGCs aligned from head to tail bud regions on both sides of the embryonic body. During the late somitogenesis period, PGCs mainly aggregated just underneath the body axis. After gut formation, PGCs aligned along both sides of the gut at the 4th- to 8th- somite regions. Finally, PGCs reached the genital ridge via the inside of the lateral plate mesoderm and dorsal peritoneum. These results suggest that localized patterns of vasa transcripts and the migration routes of PGCs are different among fish (Teleost) species, perhaps depending on the amount of germinal cytoplasm derived maternally and the timing of endoderm differentiation.

Animals↗
PubMed2004

Embryonic stages from cleavage to gastrula in the loach Misgurnus anguillicaudatus.

Early developmental staging from the zygote stage to the gastrula is a basic step for studying embryonic development and biotechnology. We described the early embryonic development of the loach, Misgurnus anguillicaudatus, based on morphological features and gene expression. Synchronous cleavage was repeated for 9 cycles about every 27 min at 20 degrees C after the first cleavage. After the 10th synchronous cleavage, asynchronous cleavage was observed 5.5 h post-fertilization (hpf), indicating the mid-blastula transition. The yolk syncytial layer (YSL) was formed at this time. Expressions of goosecoid and no tail were detected by whole-mount in situ hybridization from 6 hpf. This time corresponded to the late-blastula period. Thereafter, epiboly started and a blastoderm covered over the yolk cell at 8 hpf. At 10 hpf, the germ ring and the embryonic shield were formed, indicating the stage of early gastrula. Afterward, the epiboly advanced at the rate of 10% of the yolk cell each hour. The blastoderm covered the yolk cell completely at 15 hpf. The embryonic development of the loach resembled that of the zebrafish in terms of morphological change and gene expression. Therefore, it is possible that knowledge of the developmental stages of the zebrafish might be applicable to the loach.

Acetic Acid↗
PubMed2004

[Experimental study for a combination chemo-immunotherapy using dendritic cells].

This study was designed to seek for the optimal anticancer agents for a combination of chemotherapy and specific immunotherapy using dendritic cells (DC) in gastric cancer. We investigated the immuno-suppressive activity of anticancer agents on human peripheral blood mononuclear cells (PBMC), apoptosis inducing activity on gastric cancer cells and expression of Toll-like receptor (TLR)-4 mRNA on immatureDCs (iDCs) by paclitaxel (TXL) and docetaxel (TXT). We further compared the cytotoxicity of cytotixic T lymphocytes (CTLs) induced by DCs pulsed with tumor cell lysate and apoptotic cells induced by TXT. Although most of the anticancer agents demonstrated the suppression activity on proliferation of PBMC in a dose dependent manner, TXT, doxifluridine and irinotecan did not show the suppressive activity on PBMC even in the highest drug concentration. About 60% of gastric cancer cells demonstrated apoptosis after a 24-48 hour treatment with both TXL and TXT. Expression of TLR-4 mRNA in iDCs was up-regulated by TXT, not by TXL, and peaked at 2 hours after the treatment. CTLs induced by DCs pulsed with tumor cell lysate and apoptotic cells showed a similar killing activity to target cells. These results suggest that TXT appears to be an optimal anticancer agent for a combination therapy with chemotherapy and tumor specific immunotherapy using dendritic cells in gastric cancer.

Adult↗
PubMed2003

Recovery of fertility in male hybrids of a cross between goldfish and common carp by transplantation of PGC (primordial germ cell)-containing graft.

In germ-line chimera, gametes originate from both the donor and recipient. In order to increase the proportion of gametes from the donor, the elimination or reduction of primordial germ cells (PGCs) from the recipient is required. In the present study, histological and genetic analyses were performed in the chimeric fish obtained when sterile goldfish x common carp hybrid and fertile goldfish embryos were used as a recipient and donor, respectively. Chimerism was induced by transplantation of the lower part of the goldfish blastoderm into the hybrid blastoderm at the blastula stage. Neither spermatid nor spermatozoa were observed in the testis of the male hybrid. Motile sperm were obtained from 15 chimeric males by human chorionic gonadotropin (HCG) injection. When the sperm of chimeric fish were genetically analyzed, only goldfish-specific repetitive DNA sequences were detected. These results revealed that chimeric fish of the cross between a sterile male hybrid and fertile goldfish produced sperm exclusively derived from the donor goldfish.

Animals↗
PubMed2002

Germ cell lineage from a single blastomere at 8-cell stage in shiro-uo (ice goby).

Shiro-uo (ice goby; teleost fish), Leucopsarion petersii, shows a unique cleavage pattern characterized by two tires of blastomeres at 8-cell stage, like that of echinoderm and amphibian embryo. Such a pattern is suitable to isolation and cell lineage experiments. In this study, cell lineage of germ-line was traced by histological observation and cell labelling experiment at the 8-cell stage. Primordial germ cells (PGCs) were first detected histologically at the 10-somite stage, and migrated to gonadal anlage at 10 days post-fertilization, through usual way described in other teleost species. When a single blastomere was labelled with tracer dye at 8-cell stage, both upper and lower tires generated labelled PGCs at gonadal anlage although upper tires occasionally. This result suggests that all blastomeres at the 8-cell stage have potential to produce PGCs in shiro-uo.

Animals↗
PubMed2002

The germ cell lineage identified by vas-mRNA during the embryogenesis in goldfish.

vas RNA has been identified in germ-line cells and its precursors in zebrafish, with the result that the germ-line lineage can be traced throughout embryogenesis. In the present study, we described vas localization and the migration of vas-positive cells in goldfish, using whole mount in situ hybridization. The signals of vas mRNA localization appeared at the marginal part of the first to third cleavage planes. The eight signals were detected during the period from the 8- cells to the 512-cell stage. At the late-blastula stage, additional numbers of vas-positive cells were observed, suggesting the proliferation of these cells. At the segmentation period, vas-positive cells showed a long extended distribution along the embryonic axis, but did not form any clusters. vas-positive cells were occasionally distributed at the head region, especially around the future otic vesicle. These signals were inherited to the primordial germ cells, suggesting that vas-positive cells were primordial germ cells (PGCs) in goldfish.

Animals↗