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Biomedical subjects

K Kaji

Publications and source records attributed to K Kaji.

At least 109 records · Page 6Linked to original sources
PubMed1988

[Culture of human blood vessel endothelial cells--a simple and inexpensive culture method].

The purpose of this review is to introduce a simple and inexpensive culture method for human umbilical blood vessel endothelial cells. The medium used is MCDB-104 supplemented with 10% fetal bovine serum, 70 ng/ml endothelial cell growth factor from new-born bovine brains, 10 ng/ml murine epidermal growth factor, and 100 micrograms/ml heparin. The culture dishes are coated with gelatin. Under these conditions, endothelial cells from human vessels were grown with doubling times of 18-22 hrs and reached saturation densities of 8-12 x 10(4) cells/cm2. To determine the lifespan of the endothelial cells, the cells were serially subcultivated weekly at an inoculum size of 1,000 cells/cm2. Human endothelial cells from umbilical vein and artery were grown for 21 to 37 passages with 55 to 125 population doublings. This culture method seems to be useful for studying cell proliferation and functions of human endothelial cells.

Animals↗
PubMed1987

Identification of the 190 kD microtubule-associated protein in cultured fibroblasts and its association with interphase and mitotic microtubules.

We previously investigated the biochemical characteristics of microtubule-associated proteins (MAPs) of the adrenal medulla and adrenal cortex and found that they contain a new kind of MAP with a molecular weight of 190,000 (190 kD MAP) as a major species (Kotani, S., H. Murofushi, S. Maekawa, C. Sato, and H. Sakai. Eur. J. Biochem. 156, 23-29, 1986). We now have used an affinity purified anti-(190 kD MAP) antibody and show by indirect immunofluorescent microscopy the association of this MAP with microtubules in situ in TIG-3 cells (human embryonic lung fibroblasts). The 190 kD MAP was present along the interphase and mitotic microtubules, and there was no marked difference between the staining pattern with anti-tubulin and that with anti-(190 kD MAP) antibodies, evidence that the localization of 190 kD MAP is not restricted to the subset of microtubules. We also isolated MAPs from TIG-3 cells and identified their 190 kD MAP as a major heat-stable component. Several other unidentified polypeptides were recovered in the MAP fraction specifically.

Fibroblasts↗
PubMed1986

Megakaryocytopoiesis in vitro of patients with essential thrombocythaemia: effect of plasma and serum on megakaryocytic colony formation.

To clarify the mechanism of increased numbers of megakaryocytes in patients with essential thrombocythaemia (ET), we studied in vitro megakaryocytopoiesis in ET and other myeloproliferative disorders, using a megakaryocytic colony assay in methylcellulose containing plasma or serum and medium conditioned by phytohaemagglutinin (PHA) stimulated leucocytes (PHA-LCM). Megakaryocytic colony formation was supported well by heparinized or citrated plasma and citrated serum which was harvested after clot formation of citrated plasma. Whole serum was inhibitory for megakaryocytic colony growth. The addition of platelet releasates and partially purified platelet derived growth factor (PDGF) resulted in a decrease in the number of megakaryocytic colonies. These findings suggested that platelet-derived factor(s) in serum was inhibitory to megakaryocytic colony formation. ET plasma supported the megakaryocytic colony formation by normal or ET bone marrow cells better than normal plasma. Moreover, in ET bone marrow cells, spontaneous megakaryocytic colonies were formed in the absence of PHA-LCM. Increased megakaryocytopoiesis in ET may be ascribed to (i) increased megakaryocyte-colony stimulating activity (Meg-CSA) in plasma and (ii) increased sensitivity to Meg-CSA or autonomous proliferation of megakaryocytic progenitor cells.

Adult↗
PubMed1986

[Effect of CDDP on cultured glioma cell lines: analysis of cell kinetics by flow cytometry].

The cytokinetic response of cultured glioma cell lines to cis-dichlorodiammine platinum (II) (CDDP) was investigated by flow-cytometry using the BUdR-Hoechst technique. By this technique, the percentage of cells in the various components and the relative phase durations were calculated rapidly and simply. In the presence of CDDP ID50, perturbation of the cell cycle was shown and the cell cycle time was prolonged three times longer than in controls in the GB2 cell line. Comparison of histograms obtained at certain time intervals, cell-cycle perturbation by CDDP such as G2-block with prolongation of the S-phase and further G1 accumulation were demonstrated.

Animals↗
PubMed1985

Inhibitory effect of transforming growth factor-beta on DNA synthesis of adult rat hepatocytes in primary culture.

A transforming growth factor-beta (TGF-beta) found in platelets strongly inhibited DNA synthesis of adult rat hepatocytes in primary culture stimulated by insulin plus EGF or by hepatocyte growth factor (HGF) from rat platelets, but not the syntheses of secretory and intracellular proteins by the cells. TGF-beta had no cytotoxic effect, as judged by phase-contrast microscopic examination of the cell morphology. The inhibition of DNA synthesis by TGF-beta was correlated with marked decrease in the labeling index. TGF-beta did not inhibit growth of hepatoma cell line. These findings indicate that TGF-beta is a strong growth inhibitor of adult rat hepatocytes and may block their shift from the G1 phase to the S phase. The physiological role of TGF-beta in inhibiting growth of adult hepatocytes during liver regeneration is discussed.

Animals↗
PubMed1984

Progressive loss of the proliferative response of senescing WI-38 cells to platelet-derived growth factor, epidermal growth factor, insulin, transferrin, and dexamethasone.

Normal human diploid cell lines such as WI-38 display a progressive loss of responsiveness to the mitogenic components in serum. Using a serum-free, hormone-growth factor supplemented medium for WI-38 cells (Phillips & Cristofalo, 1980, 1981), we examined the dose-response relationships of cells to the individual growth factor at various in vitro ages. Although as cultures senesced, they became progressively less responsive to mitogenic stimulation, the concentration of epidermal growth factor (25 ng/ml), insulin (5 micrograms/ml), transferrin (5 micrograms/ml), and dexamethasone (55 ng/ml) that elicited the maximum proliferative response did not change as a function of age. As cultures age they may require increasing amounts of platelet-derived growth factor to elicit the maximum mitogenic response.

Cell Division↗
PubMed1984

[Anti-hyperlipidemic effect of iodine eggs: studies on the mechanism of its action].

The anti-hyperlipidemic effect of the iodine egg was found to be in the neutral lipid (NL) fraction in its yolk. For the purpose of clarifying the hypolipidemic effect of the iodine-containing NL fraction, the effect of clofibrate (CPIB) was investigated. CPIB was found to lower TC, atherogenic index [(TC-HDL cholesterol)/HDL cholesterol], TG and FFA, but not FC; while NL lowered TC, FC and the atherogenic index, but not TG and FFA. Cholesterol metabolites, probably metabolized in the liver, were examined. Hepatic cholesterol level was increased by NL and CPIB. The ratio of fecal bile acid of the excretion type, lithocholic acid (LCA) to deoxycholic acid (DCA), increased when NL and CPIB were administered, but the hepatic HMG-CoA reductase activity, responsible for the endogenous cholesterol synthesis, was not altered. Thus, the anti-hyperlipidemic mechanism of NL may be the mobilization of peripheral cholesterol to the liver, probably for the disposal by excretion as bile acids.

Animals↗
PubMed1984

[Antihyperlipidemic effect of iodine egg: search for active ingredients and their iodine contents].

Active fractions that possess the hypocholesterolemic effect of iodine egg yolk lipid fraction have been investigated with male Wistar strain rats fed on a cholesterol-rich diet. Iodine egg yolk lipid was extracted by Folch's (chloroform: methanol) method and was refractionated into a neutral lipid (IEY-NL) fraction and a polar lipid (IEY-PL) fraction. The iodine content in each fraction was determined. The animals were kept on the cholesterol-rich diet for 5 days, and then they were fed the fractions in addition to the above diet for 10 more days. The hypocholesterolemic effect was seen most significantly with the IEY-NL fraction. The serum total cholesterol level in rats receiving this fraction was 70% as compared with that of the Ch group (fed on the cholesterol diet). However, the liver total cholesterol level was not affected or rather increased by the IEY-NL fraction. Another fraction (IEY-PL) showed no such effect. Iodine content in the IEY-NL fraction was quite low (0.2 ppm) compared with the other fractions. The daily dose in terms of iodine in the IEY-NL fraction was only the amount equivalent to 1/50 of the reported daily requirement for the rat. The IEY-NL fraction induced the hypocholesterolemic effect, though it contained only a trace of iodine.

Animals↗
PubMed1984

[Antihyperlipidemic effect of iodine egg: Search for the screening method and active ingredients].

A screening method for the hypolipidemic effect of iodine egg and its active fractions have been investigated with Wistar strain male rats fed on a cholesterol-rich diet. The animals were kept on the cholesterol-rich diet for 5 days, and then iodine egg was fed to them in addition to the above diet for 10 more days. The present method was the most adequate for screening the hypolipidemic effect. Iodine egg yolk was fractionated into the following 3 fractions by Folch's method: Protein ( IEY -P), water-soluble ( IEY -A) and lipid ( IEY -L) fractions. The hypolipidemic effect of these fractions was determined with the screening method. The marked hypolipidemic effect was induced by the IEY -L fraction. The serum total cholesterol level in rats that received the fraction was 57% as compared with that of the ch group (fed on the cholesterol-rich diet). The other groups showed no such effect. Serum thyroid hormone levels were not affected by the IEY -L fraction which was found to be the active hypolipidemic fraction of iodine egg. The thyroid gland did not seem to participate directly in such a hypolipidemic effect.

Animals↗
PubMed1983

Isolation of deuterated histones from yeast grown on media dissolved in 2H2O.

We have succeeded in growing Saccharomyces cerevisiae (baker's yeast) on media containing 2H2O and isolating the core histones highly deuterated in the non-exchangeable positions. The deuterated histones obtained here are of great value for their possible widespread use for structural studies of chromatin.

Deuterium↗
PubMed1982

Ploidy of human embryonic fibroblasts during in vitro aging.

The DNA content of single nuclei in confluent cultures of aging human embryonic fibroblasts, TIG-3, was measured by means of flow cytofluorometry. In the early and late stages of their in vitro lifespan, they had considerable numbers of 4C, 8C and 16C nuclei. In the other period more than 95% of their nuclei were 2C nuclei. These results were confirmed by karyotype analysis. Presumably, the polyploid cells in young cell populations are removed due to their low growth potential and those in old cell populations are accumulated as a result of cellular aging. The saturation density of TIG-3 cells increased at the beginning of their lifespan and thereafter decreased. The rise in their saturation density seems to reflect cell selection advantageous for young diploid cells.

Cell Survival↗