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61.
Yoshihiro Kikkawa Hideki Abe Masahiro Fujita Tadahisa Iwata Yoshio Inoue Yoshiharu Doi 《Macromolecular chemistry and physics.》2003,204(15):1822-1831
Direct visualization of crystal growth in poly(L ‐lactide) thin films was carried out by using a temperature‐controlled atomic force microscopy (AFM). At the initial stage of crystallization, edge‐on lamellar crystals have nucleated and elongated. Subsequently, the edge‐on lamellar crystals showed S‐shaped morphology and changed their orientation from edge‐on manner to flat‐on one. The curvature of edge‐on lamellar crystal has been discussed in terms of inclination and distortion of polymer chains in the crystal. In addition, mechanism on the formation of flat‐on crystal from edge‐on lamellae was proposed as derivative growth on the basis of in situ AFM observation of crystal growth and enzymatic degradation.
62.
Szabolcs MJ Cannon PJ Thienel U Chen R Michler RE Chess L Yellin MJ 《Virchows Archiv : an international journal of pathology》2000,437(2):149-159
T cells have roles in the pathogenesis of native coronary atherosclerosis (CA) and transplant-associated coronary artery disease
(TCAD). The mechanisms by which T cells interact with other cells in these lesions are not fully known. CD154 is an activation-induced
CD4+ T cell surface molecule that interacts with CD40+ target cells, including macrophages and endothelial cells, and induces the production of pro-inflammatory molecules, including
CD54 (ICAM-1) and CD106 (VCAM-1). To investigate whether CD154-CD40 interactions might be involved in the pathogenesis of
CA or TCAD we performed immunohistochemical studies of CD154 and CD40 expression on frozen sections of coronary arteries obtained
from cardiac allograft recipients with CA (n=10) or TCAD (n=9). Utilizing four different anti-CD154 mAb we found that CD154 expression was restricted to infiltrating lymphocytes in
CA and TCAD. CD40 expression was markedly up-regulated on intimal endothelial cells, foam cells, macrophages and smooth muscle
cells in both diseases. Dual immunolabeling demonstrated many CD40+ cells co-expressed CD54 and CD106. The extent of CD40, CD54 and CD106 expression showed statistical significant correlation
with the severity of disease and the amount of intimal lymphocytes. Together these studies demonstrate the presence of activated
CD154+ and CD40+ cells in both CA and TCAD lesions and suggest that CD154-mediated interactions with CD40+ macrophages, foam cells, smooth muscle cells and/or endothelial cells may contribute to the pathogenesis of these diseases.
Received: 17 December 1999 / Accepted: 20 January 2000 相似文献
63.
Chen M Bennedsen M Zhai L Kharazmi A 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2001,109(12):801-808
A 65 kD membrane-associated NADH-fumarate reductase subunit, which has a molecular weight similar to that of one of the enzyme subunits from bacteria, was purified from Leishmania donovani promastigotes. NADH-fumarate reductase and other mitochondrial enzymatic activities of L. major and L. donovani promastigotes and amastigotes were investigated. The presence of NADH-fumarate reductase was demonstrated in digitonin-permeabilized L. major promastigotes and mitochondria of L. major and L. donovani promastigotes and amastigotes. The activity of solubilized NADH-fumarate reductase was measured in L. major and L. donovani promastigotes. Succinate exhibited a clear concentration-dependent inhibitory effect on fumarate reductase, whereas fumarate also exhibited a clear concentration-dependent inhibitory effect on succinate dehydrogenase. The data indicate that fumarate reductase is an obligatory component of the respiratory chain of the parasite. Since the enzyme is an important component in the intermediate metabolism in the Leishmania parasite and is absent in mammalian cells, it could be a potential target for antileishmanial drugs. 相似文献
64.
二氧化锗诱导L6成肌细胞株的MyoD基因表达 总被引:2,自引:0,他引:2
目的:探讨成肌细胞的MyoD基因在线粒体肌病发生发展中的作用。方法:采用二氧化锗(GeO2)处理大鼠的成肌细胞系L6,观察细胞形态的变化,利用MTT分析GeO2对成肌细胞的影响,用RT-PCR检测MyoD基因表达。结果:发现GeO2在损伤成肌细胞的同时,能够诱导MyoD基因的表达,表明MyoD基因在线粒体肌病的发生发展中起着重要作用。结论:MyoD基因表达的增强是线粒体肌病中骨骼肌萎缩的一个信号分子,MyoD基因表达有可能成为线粒体肌病检测的参考指标。 相似文献
65.
John V. Basmajian 《Psychosomatics》1982,23(1):67-73
Clinical electromyographic (EMG) biofeedback was an outgrowth of diagnostic electromyography and research on the fine control of motor units. In rehabilitation, EMG biofeedback has gained a firm place in the treatment of upper motor neuron lesions, particularly in retraining muscles and inducing relaxation of spastic muscles of stroke patients. In cerebral palsy and musculoskeletal disturbances, additional feedback transducers (e.g., electrogoniometers, pressure-sensitive and position-sensing devices) are gaining wider use. Spasmodic torticollis has proved to be particularly suitable for behavioral methods of treatment, including EMG feedback. 相似文献
66.
Y.?P.?Wang X.?X.?Zhao K.?Sonntag P.?Wehling R.?J.?SnowdonEmail author 《Chromosome research》2005,13(8):819-826
Genomic in-situ hybridization (GISH) was applied to study the behaviour of addition chromosomes in first and second backcross (BC) progenies
of hybrids between Brassica napus ssp. napus L. (AACC, 2n = 38) and Sinapis alba L. (SS, 2n = 24) produced by electrofusion. With GISH using genomic DNA of S. alba was used as probe it was possible to clearly distinguish both of the parental genomes and effectively monitor the fate of
S. alba chromosomes in the BC1 and BC2 progenies. GISH analysis confirmed the sesquidiploid genome composition (AACCS) of the BC1 progenies, which contained 38 chromosomes from B. napus and 12 chromosomes from S. alba. Genome painting in the pollen mother cells (PMCs) of the BC1 plants revealed intergenomic association between B. napus and S. alba chromosomes, whereby a maximum of 4 trivalents between AC and S chromosomes were identified at metaphase I. In the BC2 progenies, aneuploids with different numbers of additional chromosomes from S. alba, ranging from 1 to 7, were confirmed. Three putative monosomic alien addition lines were characterized, and the results are
discussed with respect to the potential for intergenomic chromosome recombination. 相似文献
67.
Two paralogous mitochondrial malate dehydrogenase 2 (Mdh2) genes of Xenopus laevis have been cloned and sequenced, revealing 95% identity. Fluorescence in-situ hybridization (FISH) combined with tyramide amplification discriminates both genes; Mdh2a was localized into chromosome q3
and Mdh2b into chromosome q8. One kb cDNA probes detect both genes with 85% accuracy. The remaining signals were on the paralogous
counterpart. Introns interrupt coding sequences at the same nucleotide as defined for mouse. Restriction polymorphism has
been detected in the first intron of Mdh2a, while the individual variability in intron 6 of Mdh2b gene is represented by an
insertion of incomplete retrotransposon L1Xl. Rates of nucleotide substitutions indicate that both genes are under similar
evolutionary constraints. X. laevis Mdh2 genes can be used as markers for physical mapping and linkage analysis. 相似文献
68.
R L McBride 《Appetite》1985,6(2):125-131
Five concentrations of an artificial orange drink were presented for sensory evaluation in three overlapping concentration ranges. Three sensory panels, each of 30 subjects, rated the concentrations for intensity of flavour (intensity scale), relation to ideal flavour intensity (ideal-point scale), and pleasantness (hedonic scale). Except for the two extreme concentrations, neither of which was presented in more than one range, in all three response tasks the mean rating for a given concentration varied with the concentration range in which it was presented. However, the mean ratings showed good correspondence across response tasks (e.g. the concentration perceived as "moderately sweet" on the intensity scale was perceived as "just right" on the ideal-point scale and of maximal pleasantness on the hedonic scale), suggesting a link between the intensity and hedonic dimensions of sensory experience. 相似文献
69.
山紫菀与紫菀镇咳祛痰作用的实验研究 总被引:2,自引:0,他引:2
本实验对山紫菀(蹄叶橐吾Ligularia fischeri Turcz.)作了镇咳、祛痰作用的研究,并与紫菀(Aster tataricus L.)在同等条件下进行了比较,它们的浓缩水煎剂均有明显的祛痰作用,而无明显的镇咳作用,二者之间无显著性差异。它们的挥发油乳剂及水煎剂也均未表现出明显的镇咳作用。紫菀挥发油毒性大于山紫菀。 相似文献
70.
Rainhardt Osieka R. Pannenbäcker Carl Gottfried Schmidt 《Investigational new drugs》1984,2(2):161-168
Summary Cyclophosphamide (CPA) is widely used against leukemic and lymphoproliferative diseases, but in vitro studies on response to this agent so far have been limited to instable derivatives with poor galenic properties. ASTA Z 7557 is a newly synthesized activated cyclophosphamide that circumvents the need for hepatic activation and has good stability. The critical cytotoxic lesions after exposure to bifunctional alkylating agents presumably are DNA interstrand crosslinks (ISC). We have, therefore, examined the formation and apparent removal of ISC after in vitro treatment with ASTA Z 7557 by use of the highly sensitive alkaline elution technique. Survival of murine L1210 cells was determined after 1 hour in vitro exposure with a D 37 value of 5.7 g/ml (from the initial shoulder part of the survival curve) and a Do value of 1.5 g/ml (from the exponential part of the curve). Previous labelling of L1210 cells by 125IUdR simplified the alkaline elution procedure but there was some cytotoxicity of the radiochemical itself with a reduction of cloning efficiency from 77% to 61 %. The maximum of ISC was observed at 6 h after initiation of treatment with much of the damage apparently removed at 24 h. The simultaneous presence of DNA single strand breaks (SSB), however, confounds the analysis of DNA damage at 24 h and early cytolysis and unaided death of human lymphocytes often preclude the analysis of macromolecular damage at this time. Human peripheral blood cells isolated from patients with leukemic or lymphoproliferative diseases showed a remarkable heterogeneity with regard to the formation of ISC at 3 h. Thus, analysis of macromolecular damage may become an additional prognostic factor for response to CPA beyond the morphologic classification of these diseases. 相似文献