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排序方式: 共有640条查询结果,搜索用时 15 毫秒
1.
Dr. Emiko Matsumoto Kazushige Hirosawa Kiyoshi Takagawa Yoshiki Hotta 《Cell and tissue research》1988,252(2):293-300
Summary A Drosophila visual mutant rdgA has photoreceptive cells which degenerate gradually after eclosion. Fine structure of the retinular cells of rdgA
KS60
and rdgA
K014
was studied during early stages of degeneration to determine the initial morphological defects. The retinular cells of these two alleles showed the following structural abnormality within 1 day after eclosion: (1) rhabdomeres were small and irregular in shape; (2) cisternae of the rough endoplasmic reticulum were more numerous than those in normal retinular cells; (3) submicrovillar cisternae were absent; and (4) lysosomes were fewer than normal. Three-dimensional reconstruction of serial sections of the ommatidia showed that the degeneration of mutant rhabdomeres proceeds more rapidly in regions remote from the nuclei. These results suggest that the process of turnover of rhabdomeric microvilli is abnormal in rdgA. We also confirmed an increase of lysosomes and destruction of cellular organelles, as reported by previous investigators at more advanced stages of degeneration. 相似文献
2.
Kiyoshi Terao Emiko Ito Motoko Oarada Misako Ohkusu Katsukiyo Yazawa Yuzuru Mikami Kazuei Igarashi 《Mycopathologia》1992,119(2):115-125
An exotoxin (HS-6) produced by Nocardia otitidiscaviarum isolated from certain lesions of cutaneous nocardiosis of a male 82-year-old patient induced severe injuries in the pancreas, liver, stomach, small intestine, heart, thymus and kidney of male ICR mice. Mice given Nocardia-free preparation of HS-6 at a dose of 1 mg/kg of body weight developed several autophagic vacuoles in the pancreas and liver within 20 min after the i.p. injection. Thereafter, the autophagic vacuoles increased in number and size with time. About 24 hr after the administration of HS-6, the liver showed marked accumulation of fat droplets in the cytoplasm of the hepatocytes. Although they contained abundant autophagic vacuoles in the regions of RER, there were no lipomatoses in the acinar cells of the pancreas, those of the chief cells and smooth muscle cells of the stomach, Paneth cells, goblet cells, smooth muscle cells of the small intestine, and plasma cells in the digestive tract. Biochemical examinations revealed that HS-6 had no significant effect on the protein synthesis of reticulocytes. Inoculation of the Nocardia into the mouse peritoneal cavities caused marked granulomatoses in the pancreas, liver and regional lymph nodes, but did not develop autophagic vacuoles in RER regions of these organs. 相似文献
3.
The modulating activity of the culture supernatant of Con A-stimulated murine spleen cells for macrophages was investigated by using M-1 cells, which could differentiate into macrophage-like cells (referred to as M+1 hereafter), cocultured in a conditioned medium (CM) containing a differentiation factor (DF) obtained from the secondary culture of murine embryonic fibroblasts. DF induced Ia antigens on M-1 cells at a high rate in parallel with the appearance of Fc-receptor (FcR)-dependent phagocytic activity for erythrocytes coated with an antibody (EA). In contrast, Con A-sup alone had no modulating effect on M-1 cells. However, the Con A-sup stimulates synergistically M-1 cells with DF. Thus, coculture of M-1 cells with Con A-sup and DF generates M++1 cells which possess higher phagocytic activity than M+1 cells. These cells also exhibited stronger accessory cell activity than M+1 cells when tested for their promoting effect on IL-2 production by Sephadex G-10-passed spleen cells. The accessory cell activity of M++1 cells was further enhanced by culture with lymphocytes in the presence of indomethacin while that of M+1 cells did not change. These findings suggest that M-1 cells probably acquire potentiating, as well as inhibitory activity at the same time when cultured with DF and Con A-sup. The functional maturation caused by Con A-sup seemed to be associated with the expression of a receptor for a lymphokine, termed phagocytosis-augmenting factor (PAF) which is present in the Con A-sup. Such a receptor appeared to be common to macrophage lineage, since PAF in Con A-sup was absorbed out with splenic adherent cells and peritoneal exudate cells (PEC) in addition to M+1 cells, but not with nonadherent splenic lymphocytes or lymphoid cell line cells, such as EL-4 and L-1210. This fact suggests that PAF is different from interferon-gamma (IFN) which is known to modulate the function of lymphocytes. Inability of PAF to bind Cibacron Blue-Sepharose, unlike IFN, supports this notion. The molecular weight of PAF is approximately 2-3 X 10(4). Thus, the present studies suggest the requirement of at least two signals for the full maturation of macrophages, a cytokine represented by DF and a lymphokine, by PAF. 相似文献
4.
UV-induced mutagenesis in Escherichia coli B/r WP2 was enhanced by certain derivatives of methyl cinnamate which themselves were not mutagenic. Methyl ferulate, methyl isoferulate and methyl sinapate showed this effect markedly. Such an enhancement effect was absent with the derivatives of cinnamic acid and ethyl cinnamate and was not observed in Escherichia coli WP2s uvrA. Methyl sinapate also enhanced 4NQO-induced mutation and suppressed liquid-holding recovery in the above repair-proficient strain. The presence of methyl sinapate in plating agar medium decreased the survival of UV-irradiated cells of a recombination-repair-deficient strain, CM571 recA. However, the effect was not observed with those of WP2s uvrA. In an in vitro experiment in which the removal rate of thymine dimers was measured, methyl sinapate clearly inhibited this repair event. From these results, we conclude that methyl sinapate inhibits DNA excision repair, thus enhancing UV mutagenicity. 相似文献
5.
Isolation and characterization of a third proteoglycan (PG-Lt) from chick embryo cartilage which contains disulfide-bonded collagenous polypeptide 总被引:11,自引:0,他引:11
A Noro K Kimata Y Oike T Shinomura N Maeda S Yano N Takahashi S Suzuki 《The Journal of biological chemistry》1983,258(15):9323-9331
Chick embryo epiphyseal cartilage has been shown to contain three different proteoglycan species (PG-H, PG-Lb, and PG-Lt). This report is concerned with the purification and characterization of the third proteoglycan, PG-Lt. The proteoglycan can be separated from the other two by virtue of its low buoyant density in a CsCl density gradient and further purified by consecutive ion exchange and gel chromatography. The final preparation is composed of PG-Lt monomer and PG-Lt oligomer. The amino acid composition of PG-Lt is quite different from that of PG-H and PG-Lb and rather resembles that of collagens with respect to high content of glycine and high degrees of hydroxylation of proline and lysine. PG-Lt monomer is composed of disulfide-bonded subunits of Mr congruent to 120,000 and 190,000 as demonstrated by its gel electrophoretic behavior after reduction with 2-mercaptoethanol. The latter, but not the former, contains dermatan sulfate chains with glucuronic acid/iduronic acid residues and yields a protein-enriched core molecule of Mr congruent to 100,000 after digestion with chondroitinase ABC. Both of the protein subunits are completely digestible with bacterial collagenase. Immunofluorescence microscopic examination of cartilage tissues, using an antibody against PG-Lt, shows that this proteoglycan exists in both the cartilage matrix and perichondrial noncartilagenous region. When chondrocytes are plated onto tissue culture dishes, the antibody stains strands found on the cell surfaces and in the intercellular space of substrate-attached cell layers, suggesting that PG-Lt mediates cell-to-cell and cell-to-substrate contacts. 相似文献
6.
Investigations of rhubarb and the bark of Rhaphiolepis umbellata led to the isolation of new flavan-3-ol glucosides. Their structures were elucidated on the basis of 1H and 13C NMR analysis hydrolytic studies as (+)-catechin 5-O-β-d-glucopyranoside and (?)-catechin 7-O-β-d-glucopyranoside. 相似文献
7.
Tomokazu Indoh Sachiko Shirakawa Tohru Kubota Teruo Yashiki Emiko Isogai Nobuhiro Fujii 《Microbiology and immunology》1996,40(9):675-679
Persistent infections with mumps virus were established in several human lymphoid cells of T-cell origin (Molt-4, TALL-1, and CCRF-CEM) and human monocyte cells (U937 and THP-1). 2′,5′-Oligoadenylate synthetase (2–5AS) activity was demonstrated to be only slightly induced by interferon (IFN) or TPA (12-O-tetradecanoyl-phorbol-13-acetate) treatment in these cells. Treatment of the persistently infected cells with IFN or TPA did not stimulate an increase in the amount of synthetase mRNA. Induction of cell differentiation and augmentation of IFN production by TPA were demonstrated in U937 cells persistently infected with mumps virus (U937-MP). Similar results for IFN production were obtained from differentiated U937 cells. It is suggested that cell differentiation of U937 cells might be associated with the development of IFN inducibility. 相似文献
8.
Comparison of OspA Serotypes for Borrelia burgdorferi Sensu Lato from Japan,Europe and North America
Toshiyuki Masuzawa Bettina Wilske Tetsuro Komikado Hiroyuki Suzuki Hiroki Kawabata Nanao Sato Koichi Muramatsu Nobutake Sato Emiko Isogai Hiroshi Isogai Russell C. Johnson Yasutake Yanagihara 《Microbiology and immunology》1996,40(8):539-545
Sixty-one Borrelia burgdorferi sensu lato strains from various sources (ticks, human, and wild animals) in Japan and two strains from ticks in Far Eastern Russia were classified on the basis of reactivity with 16 monoclonal antibodies (mAb) to outer surface protein A (OspA) and by DNA-DNA hybridization assay. Eleven OspA serotypes (J1 to J11) were recognized among the Japanese and the Far East Russian isolates (serotypes J1 to J9 were identified as B. garinii, serotype J10 was identified as B. afzelii, and serotype J11 corresponded to B. japonica), whereas 7 OspA serotypes for North American and European isolates previously reported (Bettina Wilske et al, J. Clin. Microbiol. 31:340-350, 1993) were not observed except for OspA serotype 2 which showed identical reactivity with OspA serotype J10. This finding provides helpful information for understanding the geographical distribution of Lyme disease borrelia and the development of vaccine and diagnostic tests. In conclusion: 1. B. burgdorferi sensu stricto has not been observed in Japan, 2. Japanese B. afzelii isolates are closely related to those from Europe, 3. B. garinii isolates from Japan are highly heterogeneous and apparently different from European B. garinii isolates. 相似文献
9.
We have analyzed the esterase D (EsD) polymorphism at the nucleic acid level. Two common alleles, EsD1 and EsD2, are characterized by the substitution of one amino acid (Gly-to-Glu), which is caused by the point mutation of one nucleotide (G-to-A). Individuals exhibiting the EsD1 and EsD 2 phenotypes are homozygotes for EsD 1 and EsD 2 cDNAs, respectively. Individuals showing the EsD 2-1 phenotype have two kinds of cDNAs, viz., EsD 1 and EsD 2. The point mutation difference between the cDNAs of the EsD1 and EsD2 alleles results in a different SspI digestion site. A restriction fragment length polymorphism caused by this difference with respect to the SspI digestion site makes it possible to determine the EsD phenotype using DNA samples extracted from forensic materials with no EsD enzymatic activity. 相似文献
10.
Tomonari Tsutsumi Tetsuyuki Kobayashi Hiroshi Ueda Emiko Yamauchi Shiro Watanabe Harumi Okuyama 《Neurochemical research》1994,19(4):399-406
A membrane preparation from rat brain catalyzed the hydrolysis of [2-3H]glycerol-labeled lysophosphatidylinositol (lysoPI) to yield monoacylglycerol (MG) and inositolphosphates. This phospholipase C activity had an optimal pH of 8.2. The membrane preparation did not require the addition of Ca2+ for its maximum activity, but the activity was inhibited by addition of 0.1 mM EDTA to the assay mixture and was restored by simultaneous addition of 0.2 mM Ca2+. The activity was found to be localized in synaptic plasma membranes prepared by Ficoll and Percoll density gradients. The phospholipase C was highly specific for lysoPI; diacylglycerol formation from phosphatidylinositol, and MG formation from lysophosphatidylcholine, lysophosphatidylethanolamine, and lysophosphatidylserine were below 5% of that observed with lysoPI under the conditions used. We concluded that there is a pathway for phosphatidylinositol metabolism in brain synaptic membranes which is different from the well-characterized phosphoinositide-specific phospholipase C pathway.Abbreviations PI
phosphatidylinositol
- lysoPI
lysophosphatidylinositol
- lysoPI-PLC
lysophosphoinositide-specific phospholipase C
- PI-PLC
phosphoinositide-specific phospholipase C
- MG
monoacylglycerol
- PLC
phospholipase C
To whom to address reprint requests. 相似文献