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排序方式: 共有2188条查询结果,搜索用时 250 毫秒
1.
Junichi Ishihara Nagahiro Saijo Yasutsuna Sasaki Hidehiko Nakano Akira Ozaki Hidenobu Takahashi Masanori Sakurai Kazuhiko Nakagawa Masaaki Iigo Fumihiko Kanzawa Akio Hoshi Weon Seon Hong James R. Jett Terumi Takahashi 《Cancer immunology, immunotherapy : CII》1987,24(3):185-189
Summary The antitumor effect of recombinant human tumor necrosis factor (rH-TNF) on two clones of rat fibrosarcoma with different metastatic potential to lymph nodes was examined. The colony formation of clone A, which has high metastatic potential, was completely inhibited by continuous exposure to rH-TNF at 50 U/ml. In contrast, colony formation of clone G, which has low metastatic potential, was not inhibited by high concentrations of rH-TNF (10,000 U/ml). The inhibitory effect of rH-TNF on colony formation by clone A was also observed with a 1-h exposure to rH-TNF. This effect was time and concentration dependent, as determined by the colony assay, 3H-thymidine uptake assay, and 51Cr-release assay. 3H-thymidine and 3H-uridine uptake per cell of clone A exposed to rH-TNF was not decreased. This suggests that the mechanisms of the antitumor effect of rH-TNF were not due to inhibition of DNA and RNA synthesis of tumor cells. In vivo growth and lymph node metastases of clone A inoculated i.p. to Donryu strain rats were completely suppressed by 14 consecutive i.p. injections of 105 or 106 U/kg per day of rH-TNF. On the other hand the growth of clone G was not influenced by rH-TNF administration. 相似文献
2.
Kiyoshi Takahashi Tadashi Yoshino Tadaatsu Akagi Katsuya Miyatani Kazuhiko Hayashi Hiroshi Sonobe Yuji Ohtsuki 《Virchows Archiv. B, Cell pathology including molecular pathology》1990,59(1):159-164
In order to clarify the function of human S100β- positive T-cells, S100β-positive T-leukemia cells (S100β TLC) were examined in vitro. S100β TLC were obtained from the peripheral blood of a patient with S100β-positive T-cell leukemia and enriched by an E-rosetting method. Two dimensional flow cytometric analysis indicated that the
vast majority of the E-positive fraction were S100β TLC expressing CD3 and CD8 antigens. Although S100β TLC expressed CD3 antigen, they were negative for the α/β and γ/δ T-cell antigen receptor (TCR) defined by monoclonal antibodies
(mabs) WT-31 and δ TCS-1, respectively. It was speculated that S100β TLC initially expressed α/β TCR but lost it during malignant transformation. When S100β TLC were cultured for 24 h, they acquired cytotoxic activity towards various NK-sensitive cell lines including K-562, Molt-3
and CEM-CCLF, but did not exhibit lysing activity towards NK-resistant cell lines including Raji, Daudi and MT-1. Despite
the NK-activity of cultured S100β TLC, they lacked the morphological features of large granular lymphocytes (LGL). S100β TLC did not exhibit lymphokine-activated killer (LAK) activity. When S100β TLC were cocultivated with NK-sensitive cells or NK-resistant cells, they selectively bound to NK-sensitive cells, indicating
that they lysed target cells by cell-to-cell contact. The finding that S100 β TLC lacked TCR molecules and their NK activity
was not inhibited by mabs reactive with the CD3-TCR complex indicated that the CD3-TCR complex was not involved in their target
recognition. These findings suggest that S100 β-positive T-cells are functionally similar to NK cells. We discuss the roles
of S100 β-positive T-cells in the human immune system. 相似文献
3.
H+-translocating ATPase and pyrophosphatase (PPase) associatedwith the tonoplast of Chara corallina were isolated with theaid of a perfusion technique, and the effects of ions on theiractivities were studied. All the alkali metal cations testedstimulated the ATPase and ATPdependent H+ pumping activitiesonly by 10 to 40%. Anions, on the other hand, strongly affectedthe activities. Potassium salts of Cl- and Br- stimulated them,while F- and NO3- inhibited them. By contrast, the H+-translocatingPPase was insensitive to anions but sensitive to cations. Theorder of cation stimulation was Rb+=K+>Cs+>Na+=Li+>choline+.NO3- (50 mil), thought to be a specific inhibitor of the tonoplast-typeH+-ATPase, inhibited the ATPdependent H+ pumping almost completelybut the ATPase activity by only about 50%. Na+ inhibited thePP1-dependent H+ pumping (I5O=5OmM) in the presence of 50 mMKCl but not the ATP-dependent one. The PPase was more sensitiveto F- (I50=400µM) than the ATPase. Both the H+-ATPaseand the H+-PPase required Mg2+ for their activities, althoughan excess was inhibitory to both. The different sensitivitiesof the PP1-dependent and the ATP-dependent H+- pumping enzymesto ions correspond to the tonoplast enzymes of higher plantsand may be used as "markers" to distinguish between these enzymesin characean cells (Received October 2, 1987; Accepted May 18, 1988) 相似文献
4.
Kiyoshi Takahashi Katsuya Miyatani Hiroyuki Yanai Ho Jong Jeon Kotaro Fujiwara Tadashi Yoshino Kazuhiko Hayashi Tadaatsu Akagi Ken Tsutsui Koichi Mizobuchi 《Virchows Archiv. B, Cell pathology including molecular pathology》1992,62(1):105-113
Monocytic leukemia (MoL) cells were obtained from the peripheral blood of a patient in whom the leukemic cells infiltrating
various lymphoreticular organs exhibited features intermediate between interdigitating reticulum cells (IDC) and ordinary
phagocytic macrophages, whereas the leukemic cells in the peripheral blood were essentially monocytic and lacked such features.
Peripheral blood CD4+ T-cells were established as an interleukin-2-dependent T-cell line. When the MoL cells were exposed
for a few days to conditioned medium from the T-cell line, they extended several dendritic cytoplasmic projections and became
intensely positive for HLA-DR antigen, cytoplasmic S-100β protein, and CD1 antigen. Functionally, the conditioned medium significantly
down-regulated Fc-mediated and Fc-independent phagocytic activities, and the levels of lysosomal enzymes such as lysozyme
and nonspecific esterase in the MoL cells. Moreover, the conditioned medium significantly up-regulated the accessory cell
function of the MoL cells as measured by the primary allogenic mixed leukocyte reaction (MLR). Furthermore, the conditioned
medium significantly down-regulated the expression of CD14 antigen.
Biochemical analysis indicated that the factor responsible for these changes is a protein which is distinct from known human
cytokines and whose molecular weight is approximately 31 kDa. These findings suggest that IDC are closely related the monocytic
lineage and that helper T-cells play an important role in constructing the microenvironment of T-lymphoid tissues which is
necessary for the differentiation and maturation of IDC. 相似文献
5.
Rhizome induction and plantlet regeneration of Cymbidium goeringii from flower bud cultures in vitro
Apical flower buds of Cymbidium goeringli Reichenbach fil. (ca 2 mm long) exeised from infloreseences (ca 5 cm long) were explanted on modified Murashige & Skoog medium (=MS medium) supplemented with N6-benzyladenine (BA) and -naphthaleneacetic acid (NAA). Within 107 days of culture, swelling growth, chlorophyll synthesis, and subsequent rhizome differentiation were observed. MS medium containing 0.1 mg l-1 BA and 10 mg l-1 NAA was found to be optimal for initiating rhizome development and subsequent plantlet regeneration.Explants cultured on MS medium supplemented with 1 mg l-1 NAA alone formed a mass of rhizome branches. Multiple shoots of rhizome branches were induced from apical segments when rhizomes were transferred to MS medium containing 0.1 mg l-1 BA and 10 mg l-1 NAA.Abbreviations NAA
-naphthaleneacetic acid
- BA
N6-benzyladenine 相似文献
6.
Molecular dynamics simulation of trp-aporepressor in a solvent. 总被引:1,自引:0,他引:1
Molecular dynamics simulations of Escherichia coli trp-aporepressor were carried out in the absence and presence of explicit water molecules. The vacuum simulations resulted in significant deformation of the initial X-ray structure. A solvated simulation with a nonbonded cut-off radius of 9 A gave a better result, and the most satisfactory result was obtained when electrostatic interactions within a cut-off radius of 18 A were considered by a twin-range method. The trajectory from the last simulation was used to analyze the dynamical properties of the aporepressor. The root-mean-square fluctuations of the residues showed the rigidity of the central core and the flexibility of the DNA-binding sites, consistent with the X-ray temperature factors. The dynamical cross-correlation map indicated a significant negative correlation between the central core and the two DNA-binding sites, and thus reproduced the three-domain format (a central core and two DNA-binding heads) from a dynamical point of view. The core region showed weak, but many, intra- and inter-molecular correlations, while the helix-turn-helix DNA-binding motifs were free from correlations with other regions. 相似文献
7.
Isolation and Identification of α-(γ-Aminobutyryl)-Hypusine 总被引:2,自引:2,他引:0
A new dipeptide, alpha-(gamma-aminobutyryl)-hypusine, was identified in bovine brain. This compound was isolated from trichloroacetic acid-soluble fraction of bovine brain with five steps of ion-exchange chromatography. Its structure was postulated by routine chemical analyses and determined by synthesis. The amount of the compound isolated from 1.2 kg of bovine brain was 870 nmol. 相似文献
8.
An oxygen-evolving complex has been highly purified from the thermophilic cyanobacterium Synechococcus sp. The complex, which reproducibly showed 5 major polypeptide bands of 47, 40, 35, 30 and 9 kDa on SDS-polyacrylamide gel electrophoresis and contained 3.2 Mn per QA, had an oxygen-evolving activity of 300–400 μmol/mg chl per h in the presence of 5 mM MnCl2; or CaCl2. The complex most likely represents a minimum functional unit of the photosynthetic oxygen evolution. 相似文献
9.
A Someya 《Microbiology and immunology》1986,30(6):573-588
A hybridoma clone secreting rat monoclonal antibody (MAB) designated as 3F3.5F and which reacted with a population of activated tumoricidal mouse peritoneal macrophage (M phi) was produced by the fusion of mouse myeloma cells with rat spleen cells immunized against adherent BCG-activated mouse peritoneal exudate cells (adherent BCG-PEC). The antibody was cytotoxic and of the rat IgM class. The specific reactivity of the antibody with mouse primary cells and cell lines was examined by complement-dependent cytotoxicity and indirect immunofluorescence flow cytometry analysis. The antibody was found to bind to about 40% of the adherent BCG-PEC activated in vivo and elicited peritoneal macrophages activated in vitro by lymphokine and lipopolysaccharide (LPS), to about 35% of polymorphonuclear neutrophils (PMN) 15 hr after intraperitoneal injection of BCG, to about 30% of bone marrow cells from BCG-infected mice, to about 10% of P815 mastocytoma cells and to thioglycollate-induced PEC to some degree. It did not bind to other cells tested including BCG-induced peritoneal lymphocytes, non-tumoricidal PEC, thymocytes, spleen cells, resting bone marrow cells from normal mice, lymphomas, myelomas, fibroblasts, or macrophage-cell lines. Pretreatment of adherent BCG-PEC with MAB 3F3.5F and rabbit complement caused a considerable decrease in tumor cytotoxicity toward P815 cells, but the same pretreatment of non-adherent BCG-PEC had no inhibitory effect on natural killer activity for YAC-1 cells. 相似文献