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91.
YU-311 is a monoclonal antibody reacting with cytosine arabinoside (AraC)-resistant human leukemic cell line and identifies a 92 kDa membrane protein. We have examined YU-311 reactivity with various hematopoietic disorders by an immunohistochemical method and evaluated a correlation between YU-311 expression and refractoriness to chemotherapy, retrospectively. YU-311 reacted with AraC-resistant human leukemia cell lines, in which a 92 kDa membrane protein was identified by Western blotting, whereas drug-resistant cell lines to other than AraC failed to express YU-311 antigen. The frequency of YU-311 positivity was significantly increased in relapsed cases. Only five cases were positive for YU-311 at diagnosis and 24 cases at relapse. Unexpectedly, only eight cases of relapsed leukemia/lymphoma expressed YU-311 and P-glycoprotein simultaneously. Most of the YU-311-positive relapsed cases showed clinical refractoriness for chemotherapy and then failed to induct complete remission or relapsed at short periods with short disease-free duration. These findings indicate that YU-311 expression is closely associated with some aspects of drug resistance, especially with AraC resistance.  相似文献   
92.
In order to determine in what condition and by what mechanism gp 120 can deplete not only CD4 but also CD8 T cells, an in vitro system was established in which peripheral blood lymphocytes from healthy donors were treated with recombinant gp 120. We found that gp 120 can deplete both CD4 and CD8 T cells when they have recently been activated and are exposed to IL-2-deficient conditions. Bioassay of the Fas ligand (FasL) demonstrated augmented expression and release of soluble FasL by CD4 T cells in the supernatant of this culture. The administration of anti-FasL mAb and anti-Fas mAb, both of which exhibit neutralizing activity, completely abolished the depletion of these two T cell populations in culture. Based on these findings, we concluded that FasL depletes Fas antigen expressing CD4 and CD8 T cells by programmed cell death.  相似文献   
93.
94.
The mode of degradation of long chain keto acids by two microorganisms was investigated.Escherichia coli K-12 converted 12-ketooctadecanoic acid to 4-ketodecanoic acid, accumulating some amounts of intermediates, 10-ketohexadecanoic, 8-ketotetradecanoic and 6-ketododecanoic acids. In contrast,Candida tropicalis completely metabolized the keto acid with transient accumulation of the metabolites mentioned above. The difference between the metabolism byE. coli of hydroxy acid and keto acid is that 12-hydroxyoctadecanoic acid is degraded as far as 6-hydroxydodecanoic acid, while 12-ketooctadecanoic acid can be degraded as far as 4-ketodecanoic acid.  相似文献   
95.
This study explored the relationship between three indices of intersubtest scatter and level of cognitive deterioration in a sample of 104 patients with dementia of Alzheimer's type, who ranged in age between 52 and 84 years. Scatter was highly related to education and premorbid level of functioning. Advancement of dementia was shown to be associated with decrease in scatter, which suggests caution in interpretation of high magnitude of inter-subtest scatter as an indication of brain dysfunction. Easy-to-calculate range of scatter proved to be adequate measure of scatter. Calculation of more complex indices, such as PVI, provides only minimal incremental gain.  相似文献   
96.
97.
A new simple technique applied to the ring method for determining surface tension of molten salts is described. A small-sized motor which is operated by a light-sensitive phototransistor and is suspended from a balance pan is used for lowering and rising the ring. The present method was tested by determinating the surface tension of molten NaNO(3), KNO(3), and HTS (molten NaNO(3)-KNO(3)-NaNO(2); 7-44-49 mol%). Published values for molten NaNO(3) and KNO(3) are convenient for checking whether our obtained data are adequate or not. No data, to our knowledge, are available for the surface tension of HTS. In these experiments, it was shown that the new method performed well.  相似文献   
98.
Au/CeO2 and Ir/CeO2 catalysts were observed by a transmission electron microscope in order to investigate the nano-structures of Au and Ir particles and CeO2 grains and the interface structure between metallic particles and CeO2. An annular dark field scanning transmission electron microscope (ADF-STEM) and an energy dispersive X-ray spectroscopy (EDS) revealed that the metallic particles smaller than 2 nm in diameter are highly dispersed on CeO2 supports in both catalysts. For model samples of larger CeO2 particles with flat facets of low-index surfaces, high resolution transmission electron microscopy observations of Au/CeO2 and Ir/CeO2 interfaces were made and the epitaxial relationship between Au and CeO2, (111)[110]Au//(111)[110]CeO2 has been found for the first time.  相似文献   
99.
The distribution and fate of nitrogenous compounds in a small lake was investigated. It was clarified from the direct chemical measurement that about 50–60% of ammonia nitrogen was converted to organic nitrogen and a part of them would sink down during flowing through a lake.  相似文献   
100.
BACKGROUND: The recent recognition of the association of Epstein-Barr virus (EBV) with T-cell/natural killer cell (T/NK-cell) lymphoma has documented that particular types of EBV-containing T/NK-cell lymphoma are frequently complicated by hemophagocytic syndrome (HPS). This observation suggests that both EBV and proliferating T/NK-lymphoma cells play significant roles in the development of HPS. Cytokines released from neoplastic T cells are presumed to account for the activation of macrophages, which is followed by a complex cascade of cytokine production, resulting in full-blown HPS. Five patients with B-cell lymphoma complicated by HPS were studied for elevated serum cytokines, the association of EBV, and CD25 expression of lymphoma cells; the aim of this study was to verify whether the mechanisms of HPS development hypothesized for T/NK-cell lymphoma also operate in B-cell lymphoma. METHODS: Sera were analyzed for the presence of inflammatory and immunoregulatory cytokines. Flow cytometry, immunohistology (IH), in situ hybridization (ISH), polymerase chain reaction (PCR), and Southern blot analysis were performed using bone marrow aspirates, biopsy specimens, and autopsy specimens. RESULTS: Immunophenotypic and Southern blot studies verified that the lymphoma cells of all five patients were of B-cell lineage. Bone marrow aspirates demonstrated histiocytosis with extensive hemophagocytic activity. Marked elevation of serum cytokines and expression of CD25 were observed in all five patients. However, the results of PCR, ISH using EBER1 probe, and IH for latent membrane protein indicated that these lymphoma cells were free of EBV infection. CONCLUSIONS: In patients with B-cell lymphoma, EBV infection is not necessarily required for the initiation of HPS. In this article, the pathogenesis of HPS assumed to be operative in B-cell lymphoma is discussed with reference to T/NK-cell lymphoma complicated by HPS.  相似文献   
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