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Biomedical subjects

T Kominami

Publications and source records attributed to T Kominami.

15 recordsLinked to original sources
PubMed1998

Unequal divisions at the third cleavage increase the number of primary mesenchyme cells in sea urchin embryos.

To clarify the distribution and behavior of the maternal factors that direct the differentiation of primary mesenchyme cells (PMC) in sea urchin embryos, unequal division was induced at the third cleavage with the treatment of dinitro-phenol (DNP), and the numbers of differentiated PMC were examined. The most surprising finding was that the number of PMC was considerably increased in some of the DNP-treated embryos. This increase n the number of PMC was suggested to be closely related to the size of the precocious micromeres formed at the 8-cell stage. By measuring both the size of the precocious micromeres and the number of PMC in individual embryos, it was suggested that almost all the descendants of the precocious micromeres differentiated into PMC, if the volume was less than 26 pL (about three times the volume of normal micromeres). Cell tracing experiments ascertained that precocious micromeres with small volumes behave just like micromeres formed at the fourth cleavage in normal embryos. The obtained results indicated that the maternal factors present in sea urchin embryos can direct, at least, more than three times the number of PMC, and that the number of cell divisions of the PMC lineage is not strictly regulated.

Animals↗
PubMed1998

Role of cell adhesion in the specification of pigment cell lineage in embryos of the sea urchin, Hemicentrotus pulcherrimus.

To clarify the role of cell adhesion in the specification of pigment cell lineage in sea urchin embryos, cell contacts were inhibited by Ca2+-free artificial seawater (ASW) treatment, and the number of differentiated pigment cells was examined by the method devised for the present study. Obtained results showed that inhibition of cell contacts during mid-to-late blastula stage greatly affects the number of pigment cells. Treatment with Ca2+-free ASW during 7.5-10.5 h of development drastically decreased the number of pigment cells, indicating that cell adhesion during this period is indispensable for the specification of pigment cell lineage. On the other hand, the number of pigment cells were increased by the treatment during 9.5 12.5 h of development. It was suggested that this increase was caused by excess divisions of the precursor cells, that is, the division schedule of the precursor cells was altered by inhibition of cell contacts at this period. Interestingly, the number of pigment cells was a multiple of four in a majority of embryos in which pigment cells were drastically decreased in number. These findings suggest that the founder blastomeres of the pigment cell lineage are specified during 7-10 h of development, and that these blastomeres divide twice before they differentiate into pigment cells.

Animals↗
PubMed1993

Intraductal papillary neoplasm of the pancreas.

BACKGROUND: In 1989, Morohoshi et al. reported an intraductal papillary neoplasm of the pancreas (IPNP), which was a morphologically distinct, but rare tumor. METHODS: Two cases with IPNP were analyzed by immunohistochemical and DNA flow cytometric methods. RESULTS: The patients included a 67-year-old man and a 71-year-old woman. Both tumors were characterized by a well-defined papillary growth in the cystically dilated main pancreatic ducts, associated with papillary and nonpapillary hyperplasia. Immunohistochemically, the tumor cells of both cases were positive for the epithelial markers (AE1/AE3 and CAM 5.2), and in one of the two cases, the tumor cells and hyperplastic cells surrounding the tumor conspicuously revealed multiple hormonal markers such as serotonin, somatostatin, glucagon, gastrin, and pancreatic polypeptide. The nuclear DNA content of the tumor cells of the first case, which showed moderate cellular atypia, was considered to be diploid, whereas that of the second case, which revealed severe atypia, was aneuploid. CONCLUSIONS: These results suggested that these tumors arose from multipotential stem cells capable of epithelial and neuroendocrine differentiation, and results of the flow cytometric study was related to the degree of cellular atypia of the tumors.

Adenocarcinoma, Mucinous↗
PubMed1992

A case of localized peritonitis caused by obstructive colitis proximal to rectal carcinoma: a rare manifestation of obstructive colitis.

A case of obstructive colitis associated with rectal carcinoma in a 56 year old Japanese man is reported herein. He presented to Shinkokura Hospital with severe abdominal pain following a one month history of anal bleeding and mild abdominal pain. On palpation, muscle guarding was observed in the left lower quadrant and the white blood cell count was 14,200/mm3. An exploratory laparotomy was performed under the provisional diagnosis of acute abdomen, which revealed localized peritonitis 8 cm oral to an area of rectal carcinoma. An anterior resection of the lesion was therefore performed together with a descendo-proctostomy. The histopathologic diagnosis revealed adenocarcinoma and obstructive colitis involving the entire thickness of the sigmoid colon and resultant fibrino-purulent peritonitis. His post-operative course was uneventful and he was continuing to do well on the 30th postoperative day, at the time of writing. The clinical significance of this combination of obstructive colitis with rectal carcinoma is briefly discussed following the presentation of this case.

Adenocarcinoma↗
PubMed1991

Spontaneous isolated intra-abdominal mesenteric fibromatosis. Case report.

Magnetic resonance imaging in a 54-year-old Japanese man showed a huge low-intensity abdominal mass on T1 WI and a high-intensity tumoral structure with low-intensity bundles on T2 WI. The histologic diagnosis was intra-abdominal mesenteric fibromatosis. As the levels of tissue estrogen and progesterone receptors were not elevated (both less than 5 FMOL/mg), tamoxifen treatment was not indicated.

Fibroma↗
PubMed1990

Perioperative blood transfusion and gastric cancer: adverse effects or unfavourable conditions of pretreatment?

The use of perioperative blood transfusion (PBT), the immunological status pre-operatively and at discharge from hospital, and the clinical course were examined retrospectively in 124 patients who underwent 'curative' resection for gastric cancer at Shinkokura Hospital, Japan from 1979 to 1988. The general condition of patients with PBT was worse than that of those without PBT and the pre-operative immunological status of patients with PBT was less favourable than that of those without PBT. At the time of discharge from hospital the immunological condition remained worse for patients who had been given PBT. The clinical course of patients with PBT was significantly worse. A dose-response relationship was evident but the types of blood products did not influence the outcome. Cox regression analysis adjusting for potentially confounding prognostic factors revealed that the clinical course was not altered by perioperative blood transfusion itself. These observations do not support the idea of adverse effects of perioperative blood transfusion on outcome of patients undergoing 'curative' resection for gastric cancer.

Actuarial Analysis↗
PubMed1988

Determination of dorso-ventral axis in early embryos of the sea urchin, Hemicentrotus pulcherrimus.

To elucidate a relationship between early cleavage planes and dorso-ventral (DV)-axis of sea urchin embryos, a fluorescent dye, Lucifer Yellow CH, was iontophoretically introduced into one blastomere at the 2-cell stage, and the location of the progeny cells was determined in the half-labeled prism larvae by examining the embryos from the animal pole. The boundary plane which divides the embryonic tissue into the labeled and nonlabeled parts was (1) coincident with, (2) perpendicular to, or (3) obliquely crossing the larval plane of bilateral symmetry. The oblique boundaries took only two angles mutually symmetrical with regard to the DV-axis of embryos. Combining these labeling patterns, the tissue of prism larvae could be divided into 8 sectors around the animal-vegetal axis. When the 2-cell stage embryos with different diameters of sister blastomeres were labeled with the dye, one end of the boundary plane was again found at one of the 8 boundary points noticed in equally cleaved embryos, while the other was observed to fall in the middle of a sector. These results indicate that the DV-axis of the embryo is established according to the spatial arrangement of blastomeres during the 5-6th cleavage stages when blastomeres align in 8 rows in meridional direction. It was also suggested that intercellular communication takes part in the determination of the fate of individual founder blastomeres during the two subsequent cleavages, i.e., 7-8th cleavage stages.

Animals↗
PubMed1987

Purification and characterization of a major glycoprotein in rat hepatoma plasma membranes. One of the membrane proteins released by phosphatidylinositol-specific phospholipase C.

A major glycoprotein of rat hepatoma plasma membranes was selectively released as a soluble form by incubating the membrane with phosphatidylinositol-specific phospholipase C. The soluble form corresponding to the glycoprotein was also prepared by butan-1-ol extraction of microsomal membranes at pH 5.5, whereas extraction at pH 8.5 yielded an electrophoretically different form with a hydrophobic nature. The soluble glycoprotein extracted at pH 5.5 was purified by sequential chromatography on concanavalin A-Sepharose, Sephacryl S-300 and anti-(alkaline phosphatase) IgG-Sepharose, the last step being used to remove a contaminating alkaline phosphatase. The glycoprotein thus purified was a single protein with Mr 130,000 in SDS/polyacrylamide-gel electrophoresis, although it behaved as a dimer in gel filtration on Sephacryl S-300. The glycoprotein was analysed for amino acid and carbohydrate composition. The composition of the carbohydrate moiety, which amounted to 64% by weight, suggested that the glycoprotein contained much larger numbers of N-linked oligosaccharide chains than those with O-linkage. It was confirmed that the purified glycoprotein was immunologically identical not only with that released by the phospholipase C but also with the hydrophobic form extracted with butan-1-ol at pH 8.5. The results indicate that the glycoprotein of rat hepatoma plasma membranes, which has an unusually high content of carbohydrate, is another membrane protein released by phosphatidylinositol-specific phospholipase C, as documented for alkaline phosphatase, acetylcholinesterase and Thy-1 antigen.

1-Butanol↗
PubMed1985

Electrophoretic characterization of hepatic alkaline phosphatase released by phosphatidylinositol-specific phospholipase C. A comparison with liver membrane and serum-soluble forms.

Alkaline phosphatase was solubilized from plasma membrane of rat liver with butanol-ol, bile acids or sodium deoxycholate, and electrophoretically compared with a soluble form in serum which was derived from the liver. The three enzyme preparations from the plasma membrane migrated at the same position on polyacrylamide-gel electrophoresis in the presence of either Triton X-100 or sodium dodecyl sulphate. The mobility of them, however, was distinctly different from that of the serum-soluble form of the liver-derived alkaline phosphatase. On the other hand, phosphatidylinositol-specific phospholipase C isolated from Bacillus cereus was used to release alkaline phosphatase from plasma membrane. The released alkaline phosphatase was demonstrated to have the same mobility as the serum-soluble form on polyacrylamide-gel electrophoresis in the presence or absence of detergents. The phospholipase C also converted the butan-1-ol-extracted membrane form into the serum-soluble form. The results suggest that release of alkaline phosphatase from the liver into serum is not simply caused by a detergent effect of bile salts, but involves an enzymic hydrolysis of phosphatidylinositol, with which alkaline phosphatase may strongly interact in the membrane.

1-Butanol↗
PubMed1985

pH-dependent conversion of liver-membranous alkaline phosphatase to a serum-soluble form by n-butanol extraction.

Alkaline phosphatase released from rat liver plasma membrane under usual conditions was electrophoretically not identical with a soluble form in serum which was derived from the liver. The liver-membranous alkaline phosphatase, however, was converted to the serum-soluble form when the liver plasma membrane was treated with n-butanol under the acidic conditions lower than pH 6.5. Such pH-dependent conversion of the enzyme was not observed in plasma membrane of rat ascites hepatoma AH-130 cells. The converting activity for alkaline phosphatase was detected not only in plasma membrane but also in lysosomal membrane of rat liver.

1-Butanol↗
PubMed1984

Induction of rat hepatic alkaline phosphatase and its appearance in serum: electrophoretic characterization of liver-membranous and serum-soluble forms.

Simultaneous bile duct ligation and colchicine injection (2 mg/kg body weight) in rats caused a remarkable induction of alkaline phosphatase in the liver. Concomitantly, a marked elevation of the enzyme activity occurred in the serum, and three activity peaks (peaks I, II, and III) were separated by Sephadex G-200 gel filtration. By several criteria for alkaline phosphatase isoenzymes it was determined that the liver-derived enzyme was distributed in peak I (30% of total serum activity) as a vesicle-bound form and in peak II (65%) as a soluble form, while the intestinal enzyme was contained in peak III (5%). The serum alkaline phosphatase in peaks I and II was compared with the liver enzyme extracted from plasma membrane with n-butanol. Under non-reducing conditions, the soluble form of peak II showed an electrophoretic mobility different from that of the liver enzyme; in the presence of sodium dodecyl sulfate the serum-soluble form migrated a little more slowly than the liver one, while in the presence of Triton X-100 the former migrated much faster than the latter. The sedimentable fraction of peak I was found to contain two forms corresponding to the serum-soluble and liver-membranous forms. Neuraminidase treatment of these two forms reduced their mobilities but did not abolish the relative difference in their mobilities on gel electrophoresis in the presence of either Triton X-100 or sodium dodecyl sulfate. Under reducing conditions, however, each form (which was dissociated into single subunits) migrated with an identical mobility on sodium dodecyl sulfate gel electrophoresis. These results suggest that the hepatic alkaline phosphatase exists as conformationally different forms in the serum and the liver membrane (even solubilized), but the difference is no longer preserved after their denaturation into subunits.

Alkaline Phosphatase↗
PubMed1984

Allocation of mesendodermal cells during early embryogenesis in the starfish, Asterina pectinifera.

The volume of archenteron tissue (mesendoderm) in the early-to-middle gastrula of the starfish Asterina pectinifera was nearly one-quarter of whole embryo. Treatment with LiCl during 7-10 h increased this volume ratio by about 30%, whereas the total volume and the total number of cells of whole embryo remained unchanged. Such a relative increase in mesendodermal part and simultaneous reduction in ectodermal part by LiCl treatment was confirmed by counting the number of constituent cells of these parts at early bipinnaria stage. Pulse treatment with LiCl revealed that the effective period of the treatment is limited from 7 to 10 h of development, when tightly packed blastulae are formed through increase in adhesiveness of blastomeres. These results indicate that a fraction of presumptive ectodermal cells can change its fate to mesendoderm during 7-10 h of development. Cellular interactions during a specific stage of development are suggested to be involved in the determination of mesendodermal tissue.

Animals↗
PubMed1983

Establishment of embryonic axes in larvae of the starfish, Asterina pectinifera.

In order to clarify the relationships between the first cleavage plane and the embryonic axes, early cleavage pattern of the fertilized eggs of the starfish. Asterina pectinifera was reexamined. It was ascertained that the polar bodies were formed at the site to which the germinal vesicle had closely located before the initiation of the meiotic division, and that the first cleavage plane passed near this site of polar body formation. While some of the early embryos of this starfish were observed to show various cleavage patterns during early cleavage stage, more than 70% of the embryos developed according to, so to say, the 'typical' cleavage pattern. Next, horseradish peroxidase (HRP) was injected into one of the blastomeres of the 2-cell- or 8-cell-stage embryos. The embryos were allowed to develop up to either the early gastrula or the early bipinnaria stage and stained to detect the descendants of the blastomere injected with HRP. In early gastrulae still retaining radial symmetry, the activity of HRP injected at the 2-cell stage was found only in one side of the embryo partitioned by one of the symmetrical planes. When one of the four blastomeres lying nearer to the polar bodies at the 8-cell stage was marked with HRP, its descendants constituted one quarter of the anterior part of the gastrula, and descendants of a blastomere opposite the polar bodies were found in the posterior region of the embryo. It was concluded that the animal-vegetal (AV) axis was pre-existing in the fertilized egg and that the first cleavage plane contained this primary axis. In early bipinnariae with their dorsoventral (DV) axes already established, the region of activity of the HRP injected at the 2-cell stage was still demarcated by a plane which passed through the AV axis, but the plane of the boundary had no fixed relation to the DV axis. The results indicate that the first cleavage plane does not necessarily correspond to the median plane of the starfish larva, unlike the case in sea-urchin eggs (Hörstadius & Wolsky, 1936). In other words, the DV axis of the starfish embryo is not predetermined in the fertilized egg, and might be established in the course of development through cell-to-cell interactions, while the AV axis is established mainly according to the pre-existing egg polarity.

Animals↗