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991.
992.
本文在大系列研究造血系统恶性肿瘤-白血病和白血病前期的基础上,对31例恶性肿瘤患者骨髓进行血液学、细胞和分子遗传学研究。发现恶性肿瘤患者骨髓有与白血病前期骨髓相似的病态造血(Myelodysplasia)和相关基因异常即c-erbB基因重排、扩增和c-erbA缺失。它们不仅同骨髓红系病态造血相关,也同巨核系病态造血相关。骨髓巨核系病态造血及其相关基因异常可能代表急性淋巴细胞白血病等多种恶性肿瘤的早期病变。而c-erbB重排及其相关的骨髓巨核系异常增生可能是肿瘤发病的遗传背景。 相似文献
993.
肺炎患儿白细胞变形能力和粘附功能的变化及临床意义 总被引:1,自引:2,他引:1
肺炎患儿白细胞变形能力和粘附功能的变化及临床意义林荣军1刘成玉2潘玉娟3徐丽园研究表明,白细胞与急性肺组织损伤有密切关系[1],白细胞在肺内聚集是产生急性肺损伤的重要环节,而细胞粘附分子(cAms)介导的各种白细胞的粘附,特别是中性粒细胞粘附和跨膜转... 相似文献
994.
Oyarzo MP Lin P Glassman A Bueso-Ramos CE Luthra R Medeiros LJ 《American journal of clinical pathology》2004,122(3):348-358
We report 12 cases of t(6;9)(p23;q34)-positive acute myeloid leukemia (AML), all classified using the criteria of the World Health Organization classification. There were 10 women and 2 men with a median age of 51 years (range, 20-76 years). Dysplasia was present in all cases (9 previously untreated), and basophilia was present in 6 (50%). Immunophenotypic studies showed that the blasts were positive for CD9, CD13, CD33, CD38, CD117, and HLA-DR in all cases assessed. CD34 was positive in 11 (92%) of 12, and terminal deoxynucleotidyl transferase was positive in 7 (64%) of 11 cases. The t(6;9) was the only cytogenetic abnormality detected in 7 cases (58%), and 5 cases had additional chromosomal abnormalities. Of 8 cases assessed, 7 (88%) had flt3 gene mutations. We conclude that t(6;9)-positive AML cases have distinctive morphologic features, an immunophenotype suggesting origin from an early hematopoietic progenitor cell, and a high frequency of flt3 gene mutations. 相似文献
995.
Wen-Po Lin Hsing-Lung Lai Yi-Lin Liu Yin-Mei Chiung Chia-Yang Shiau Jun-Ming Han Chuen-Mi Yang Yu-Tien Liu 《Journal of microbiology, immunology, and infection》2005,38(5):320-326
A recombinant plasmid, pYL-1, containing a tyrosinase gene whose expression is under the control of a phage T5 promoter and 2 lac operators, was constructed. Escherichia coli JM109 harboring pYL-1 was used for production of bacterial melanin. A simple procedure for the isolation and purification of melanin was developed. The ultraviolet (UV)-visible light absorption spectra of melanin prepared by chemical synthesis and derived from different organisms, including bacteria, a plant and an animal source, were determined. Melanins produced by both bacteria and chemical synthesis showed a steady increase of absorption at wavelengths of UV light ranging from approximately 200-400 nm, while melanin derived either from plant or animal sources showed an additional discrete absorption peak at wavelength 280 nm upon a similar steady increase of absorption. This additional absorption peak could be due to the presence of protein-bound melanins in animal and plant sources while a free form of melanin was obtained from bacteria and chemical synthesis. Analysis of the effect of bacterial melanin on the activity of antibiotics against E. coli revealed that the activities of polymyxin B, kanamycin, tetracycline, and ampicillin were markedly reduced in the presence of melanin, whereas the activity of norfloxacin was not affected. The reduction of the antibacterial activity may result directly from the interaction of antibiotics with melanin. However, the mechanism of this interaction remains to be demonstrated. 相似文献
996.
磷脂双层膜稳定性的理论分析 总被引:2,自引:0,他引:2
目的:越来越多磷脂双层膜的原子力显微镜扫描力谱显示溶液离子浓度对磷脂双层膜稳定性有很大影响,本文从理论角度研究溶液离子浓度对磷脂双层膜稳定性的影响,同时解释两个基于不同模型模拟结果差别的原因。方法:主要根据磷脂分子极性端带电特性,将极性端看作偶极子,然后基于偶极-偶极相互作用理论以及泊松-玻尔兹曼理论解决以上问题。结论:随着离子浓度的增加,磷脂双层膜趋于更加稳定;基于两个不同模型模拟结果差别的原因是高浓度溶液的强静电屏蔽作用。 相似文献
997.
基于互信息的医学图像配准实验 总被引:4,自引:2,他引:4
基于互信息的配准方法,包括互信息和归一化互信息方法,是目前医学图像配准中无创、自动且精度很高的一种方法。已经被广泛应用。但是在其目标函数中存在着一定程度的幅值振荡现象。特别是在单模态图像配准中。我们研究发现,产生这种振荡的原因除了插值赝像外,还有由配准过程中图像重叠部分发生变化而引起的熵的变化不确定性。由插值赝像所带来的振荡基本上可以被消除掉;由熵的变化不确定性所带来的振荡很难被消除,但是这种振荡作用在归一化互信息中影响不大。归一化互信息比互信息具有更高的稳健性,适合于更广的应用范围。 相似文献
998.
目的:观察盐酸替罗非班对平板运动试验中ST段抬高患者TIMI血流分级的影响。方法:将平板运动试验ST段抬高患者35例按就诊顺序随机双盲分为受试组(n=18)和对照组(n=17),受试组在对照组给予阿司匹林、氯吡格雷、肝素等基础治疗上加用盐酸替罗非班,所有患者疗程结束后均行选择性冠状动脉血管造影(SCA)检查,观察两组患者治疗后TIMI血流情况。结果:与对照组相比,受试组应用盐酸替罗非班后TIMI血流分级提高,达2级血流者比例高于对照组(44.44%比11.76%,P<0.05);受试组完全闭塞者比例明显低于对照组(5.56%比35.29%,P<0.05)。结论:盐酸替罗非班可以改善平板运动试验中ST段抬高患者TIMI血流分级。 相似文献
999.
Cellular characterization of blastocysts derived from rabbit 4-, 8- and 16-cell embryos and isolated blastomeres cultured in vitro 总被引:2,自引:0,他引:2
The purpose of this study was to investigate the developmental potential of isolated rabbit blastomeres under various culture conditions to gain insight into their ability to form the two cell lineages of a viable blastocyst. Intact embryos at the 4-cell, 8-cell, 16-cell stages and blastomeres isolated from 4-, 8- and 16-cell rabbit embryos (1/4, 1/8 or 1/16 blastomeres respectively) were cultured in drops of one of three different media, each supplemented with either fetal calf serum (FCS), bovine serum albumin (BSA) or polyvinyl alcohol (PVA). The effects of the extracellular matrix fibronectin (FN) on the development of isolated rabbit blastomeres were also investigated. Supplementation of the medium with FCS yielded a higher (P < 0.05) proportion of blastocysts than BSA or PVA, predominantly from 1/4 blastomeres. No major differences were found between the three basic culture media. In 1/4, 1/8 or 1/16 blastomeres, blastocyst formation rates were greater (P < 0.05) in groups cultured in matrix-free (54.5, 59.6 and 54.6% respectively) than in FN-coated groups (35.4, 46.0 and 26.1% respectively). Only in blastocysts derived from 1/4 blastomeres, were the numbers of inner cell mass (ICM) and total cells of blastocysts higher (P < 0.05) in FN-coated groups than in matrix-free groups (12.7 +/- 1.1 versus 8.5 +/- 0.7 ICM, 73.8 +/- 3. 7 versus 57.8 +/- 3.3 total cells). The percentage of blastocysts derived from single blastomeres with ICM cells decreased with increasing cell stage of the parent embryos in FN-coated (93.6, 78.3 and 44.0%, respectively) as well as matrix-free groups (96.2, 69.3 and 55.2%). In FN-coated groups, after 96 h (1/4) or 72 h (1/8 and 1/16) of culture, approximately 20-30% of blastomeres did not develop into normal blastocysts but formed sheets with 30-50 cells attached to the bottom of the dishes. These results indicate that the development of rabbit blastomeres shares important characteristics with those from mouse and domestic species and may thus aid in developing an efficient culture system for blastomeres, derived from human embryos. 相似文献
1000.
目的:从蛋白质可逆磷酸化修饰的角度初步勾勒出CCKB型受体介导的胞内信号转导途径。方法:培养的小鼠大脑皮质神经元分为实验组、对照组和受体拮抗剂组,在无磷培养基加入 [32P]-NaH2PO4标记细胞中的磷蛋白后,刺激组给予CCK8(10-7 mol/L),对照组加入等量的无磷培养基,受体拮抗剂组在分别加入CCKA型、CCKB型受体拮抗剂L364 718、L365 260以及L364 718+L365 260,浓度均为10-8 mol/L,孵育10 min后,再加入10-7 mol/L CCK8,37 ℃作用60 min,液氮中终止磷酸化反应。裂解细胞提取蛋白质,双向电泳分离,放射自显影7d后,获得磷酸化蛋白的放射自显影双向电泳图谱。采用PDQuest 2D分析软件对图谱进行差异分析,并在Swiss-Prot蛋白质数据库和自建磷蛋白数据库中查询定性。结果:CCK8作用60 min后,小鼠神经元CCK8信号转导相关磷酸化蛋白有:多种蛋白激酶、细胞信号分子、生长因子受体、转录因子等。加入L364 718后,神经元中PKCδ、P55G等的磷酸化水平降低,加入L365 260后, PKCα、PKGβ、OGFR、EGFR等的磷酸化水平呈现不同程度的降低,表明皮质神经元中CCKB受体介导的信号转导更复杂。结论:CCKA型、GGKB型受体均可介导CCK8在神经元的信号转导,但CCKB型受体可能发挥了更重要的作用,其介导的信号途径可能包括:肌醇磷脂信使系统、cAMP-PKA途径、MAPK途径、JNK途径、PI3K-PKB途径和cGMP-PKG途径。 相似文献