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排序方式: 共有1584条查询结果,搜索用时 234 毫秒
31.
GS Wengler A Lanfranchi T Frusca R Verardi A Neva D Brugnoni S Giliani M Fiorini P Mella F Guandalini E Mazzolari S Pecorelli LD Notarangelo F Porta AG Ugazio 《Canadian Metallurgical Quarterly》1996,348(9040):1484-1487
BACKGROUND: X-linked severe combined immunodeficiency (SCIDXI) is an inherited immune defect which leads to death in infancy from severe infections. The defect is caused by mutations of the IL-2RG gene that encodes for the common gamma chain shared by several cytokine receptors. The disease is characterised by lack of T and NK cells with normal numbers of B cells. SCIDXI can be cured by bone marrow transplantation (BMT) or prevented by abortion after prenatal diagnosis. METHODS: A male fetus was diagnosed as having SCIDXI by molecular, immunophenotypic, and functional analyses. The fetus was injected intraperitoneally under ultrasound guidance with CD34 haematopoietic progenitor cells purified from paternal bone marrow and T-cell depleted by E rosetting. Chimerism analysis was by HLA-DQ alpha typing and gamma-chain staining on cord blood. FINDINGS: A healthy 3.6 kg boy was delivered by caesarean section at 38 weeks of gestation with no clinical or laboratory signs of graft-versus-host disease. Engraftment of donor-derived CD2 cells was found at birth. At 3.5 months of age the infant is well and his T-cell counts and function are normal. INTERPRETATION: In-utero transplantation of haematopoietic progenitor cells allowed immune reconstitution of a fetus with SCIDXI and may be an alternative to elective abortion. Our report should encourage applications of this method to other inherited disorders curable by BMT. 相似文献
32.
LD Castiel 《Canadian Metallurgical Quarterly》1996,30(1):91-100
Large granular lymphocytes require adherence to hyphae of Candida albicans to inhibit growth of this fungus. This study was undertaken to identify the lymphocyte surface structures that mediate this adhesion. Monoclonal antibodies specific for epitopes of the alpha subunit (CD11b) and the beta 2 subunit (CD18) of Mac-1 eliminated lymphocyte adhesion to C. albicans hyphae. Significant inhibition of lymphocyte adhesion to C. albicans was also achieved with known protein ligands of Mac-1. These proteins included the extracellular matrix proteins vitronectin, laminin, and fibrinogen as well as two engineered peptides containing RGD (arginine-glycine-aspartic acid) sequences. Carbohydrates including N-acetyl-D-glucosamine which have been demonstrated to inhibit Mac-l-mediated adhesion to whole yeast and yeast zymosan also blocked lymphocyte adhesion to hyphae. These results identify Mac-1 (CD11b/CD18) as the surface structure that mediates lymphocyte adhesion to C. albicans. A model is proposed for lymphocyte Mac-1 activation by microbial ligands. 相似文献
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RK Achazi C Flenner DR Livingstone LD Peters K Schaub E Scheiwe 《Canadian Metallurgical Quarterly》1998,121(1-3):339-350
The cytochrome P450 system of the oligochaetes Eisenia f. fetida (tiger worm) and Enchytraeus crypticus (pot worm) was analysed using ethoxy-, pentoxy- and benzoxyresorufin as substrates for monooxygenase activity. Whole body microsomes of the earthworm E.f. fetida displayed PentROD activity in the range from 0.26 to 1.05 pmol mg protein-1 min-1 and BenzROD activity in the range from 0.14 to 0.30 pmol mg protein-1 min-1. Exposure of the animals for up to four weeks to 100 mg fluoranthene or benzo[a]pyrene kg-1 soil (dry weight) did not induce significant changes in the activity of these monooxygenases. In E. crypticus EROD activity was in the range from 2.10 to 6.18 pmol mg protein-1 min-1 and PentROD activity in the range from 1.75 to 4.78 pmol mg protein-1 min-1. Short-term exposure to BaP by feeding reduced the EROD activity significantly by 45%, but did not effect PentROD activity. After long-term (8 weeks) exposure to BaP in the agar-agar medium EROD activity was not changed but PentROD had decreased to zero. In both species cytochrome P420 and NADPH-cytochrome C reductase activity were present. In E.f. fetida microsomes are associated with the giant haemoglobin. Both can be separated by gel filtration on a Sepharose B2 column or by hydrophobic interaction chromatography after solubilisation with cholate. NADPH-cytochrome C reductase elutes together with haemoglobin. Cytochrome P420 is eluted with Emulgen 911 and can be further purified by ion exchange chromatography using HA-Ultrogel. By SDS-PAGE of the purified microsomal proteins three protein bands are visualised in the range of cytochrome P450 displaying an apparent molecular mass of 54, 56 and 58 kDa. Only the 54-kDa protein interacts weakly with perch (Perca fluviatilis) CYP1A antibodies, while two proteins with an apparent molecular mass of 65 and 71 kDa give a strong antibody signal. 相似文献
35.
JL Cohen J Cheirif DS Segar LD Gillam JS Gottdiener E Hausnerova DE Bruns 《Canadian Metallurgical Quarterly》1998,32(3):746-752
We investigated whether changes in iron metabolism and the transferrin receptor (TRF-R) expression were involved in the antileukaemic effects of arabinoside cytosine (ara-C). Treatment with 100 nM ara-C for 48h reduced thymidine uptake and increased the surface expression of the TRF-R on leukaemic blasts derived from 13/16 (81%) patients and on the HL-60 and U-937 cell lines. Whereas intracellular non-haem iron was strongly depleted 24 h after ara-C addition, TRF-R up-regulation and recovery of intracellular non-haem iron concentration occurred together after a longer exposure of the cultured cells to the drug. Since iron is an essential regulator of cell proliferation we have evaluated the effects of the combination between ara-C and the iron chelator desferioxamine (DSF) on the growth of HL-60 and U-937 cells. We found that desferioxamine strongly potentiated the effects of ara-C on leukaemic cell growth inhibition and apoptosis. This is the first report of a positive interaction between ara-C and an iron chelator in terms of antileukaemic effects. 相似文献
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UV absorbance spectroscopy is the most common method for detecting nucleic acid structural transitions and obtaining thermodynamic parameters. UV-detected melting has been used to determine stabilities of nucleic acid hairpins, duplexes, triplexes, and higher order structures and to determine thermodynamic effects of unusual or modified bases and mismatched base-pairs. We report that in some cases UV absorbance spectroscopy is an inadequate analytical technique for these purposes. Some critical transitions are invisible to UV absorbance spectroscopy. For example, the conversion of dodecamer d(CGCAAATTCGCG) from hairpin to random coil is not accompanied by hyperchromism. Circular dichroism (CD) spectroscopy (263 nm) clearly detects two transitions for this dodecamer, each giving a pronounced change in ellipiticity. The concentration dependence of the low-temperature transition and the concentration independence of the high-temperature transition indicate that the predominant state converts from duplex to hairpin to random coil as the temperature increases. These assignments are confirmed by comparison to oligonucleotides of similar sequence that undergo a hairpin to coil transition only. In contrast to CD spectroscopy, UV absorbance spectroscopy shows only a single transition. The transition detected by UV absorbance spectroscopy corresponds to the low-temperature transition detected by CD. UV absorbance spectroscopy does not detect the second transition at any wavelength (from 218 to 310 nm) (by changes) in either absorbance or its derivative with temperature. 相似文献
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Cleyo Harris Travis O. Brenden Chris S. Vandergoot Matthew D. Faust Seth J. Herbst Charles C. Krueger 《Journal of Great Lakes research》2021,47(1):48-58
Infrequent captures of invasive, non-native grass carp (Ctenopharyngodon idella) have occurred in Lake Erie over the last 30+ years, with recent evidence suggesting wild reproduction in the lake’s western basin (WB) is occurring. Information on grass carp movements in the Laurentian Great Lakes is lacking, but an improved understanding of large-scale movements and potential areas of aggregation will help inform control strategies and risk assessment if grass carp spread to other parts of Lake Erie and other Great Lakes. Twenty-three grass carp captured in Lake Erie’s WB were implanted with acoustic transmitters and released. Movements were monitored with acoustic receivers deployed throughout Lake Erie and elsewhere in the Great Lakes. Grass carp dispersed up to 236 km, with approximately 25% of fish dispersing greater than 100 km from their release location. Mean daily movements ranged from <0.01 to 2.49 km/day, with the highest daily averages occurring in the spring and summer. The Sandusky, Detroit, and Maumee Rivers, and Plum Creek were the most heavily used WB tributaries. Seventeen percent of grass carp moved into Lake Erie’s central or eastern basins, although all fish eventually returned to the WB. One fish emigrated from Lake Erie through the Huron-Erie Corridor and into Lake Huron. Based on our results, past assessments may have underestimated the potential for grass carp to spread in the Great Lakes. We recommend focusing grass carp control efforts on Sandusky River and Plum Creek given their high use by tagged fish, and secondarily on Maumee and Detroit Rivers. 相似文献
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