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171.
耐钙心肌细胞的分离和电生理特性观察 总被引:11,自引:1,他引:11
用快速、恒压的无钙和胶原酶Tyrode液相继灌流豚鼠心脏冠脉系统后,再经无钙液室温浸泡心脏和用改变的K-B液帮助分离细胞的恢复,可获得耐钙的游离心肌细胞。全细胞电流记录:静息电位为-72±9mV(n=12),并显示出快内向电流(INa),可被异搏定阻断的慢钙离子流和时间依赖性外向钾流(Ik);单通道记录分别显示了Na+Ca2+和K+通道的电压依赖性等特征。结果表明了用此法分离的细胞具有耐钙性和正常电生理特性。 相似文献
172.
The soybean cyst nematode Heterodera glycines Ichinohe is a severe agricultural pest for which genetic resources are limited. In this study, 295 simple sequence repeats (SSRs) were identified from 259 expressed sequenced tags (ESTs), which were selected from 9,443 unigenes. The successful primer pairs were designed against six regions. In total, 30 alleles were identified from 30 individuals using the six markers, with an average of five alleles per locus (range, 4–7). The observed and expected heterozygosities were 0.074–0.900 and 0.266–0.775, respectively. Significant departure from Hardy-Weinberg equilibrium was found at three of the six loci. The EST-based SSR markers developed in this study may contribute to better under-standing of the genetic structure of H. glycines populations. 相似文献
173.
Zhou Q Li M Wang X Li Q Wang T Zhu Q Zhou X Wang X Gao X Li X 《International journal of biological sciences》2012,8(1):118-123
Breast milk is a complex liquid rich in immunological components that affect the development of the infant's immune system. Exosomes are membranous vesicles of endocytic origin that are found in various body fluids and that can mediate intercellular communication. MicroRNAs (miRNAs), a well-defined group of non-coding small RNAs, are packaged inside exosomes in human breast milk. Here, we identified 602 unique miRNAs originating from 452 miRNA precursors (pre-miRNAs) in human breast milk exosomes using deep sequencing technology. We found that, out of 87 well-characterized immune-related pre-miRNAs, 59 (67.82%) are presented and enriched in breast milk exosomes (P < 10(-16), χ(2) test). In addition, compared with exogenous synthetic miRNAs, these endogenous immune-related miRNAs are more resistant to relatively harsh conditions. It is, therefore, tempting to speculate that these exosomal miRNAs are transferred from the mother's milk to the infant via the digestive tract, and that they play a critical role in the development of the infant immune system. 相似文献
174.
Flow cytometric analysis of the chromosomes and stability of a wheat cell-culture line 总被引:3,自引:0,他引:3
T. Schwarzacher M. L. Wang A. R. Leitch G. Moore J. S. Heslop-Harrison N. Miller 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(1):91-97
A rapidly growing, long-term suspension culture derived from Triticum aestivum L. (wheat) was synchronized using hydroxyurea and colchicine, and a chromosome suspension with chromosomes was made. After staining with the DNA-specific fluorochromes Hoechst 33258 and Chromomycin univariate and bivariate flow-cytometry histograms showed 15 clearly resolved peaks corresponding to individual chromosome
types or groups of chromosomes with similar DNA contents. The flow karyotype was closely similar to a histogram of DNA content
measurements of Feulgen-stained chromosomes made by microdensitometry. We were able to show the stability of the flow karyotype
of the cell line over a year, while a parallel subculture had a slightly different, stable, karyotype following different
growth conditions. The data indicate that flow cytometric analysis of plant karyotypes enables accurate, statistically precise
chromosome classification and karyotyping of cereals. There was little overlap between individual flow-histogram peaks, so
the method is useful for flow sorting and the construction of chromosome specific-recombinant DNA libraries. Using bivariate
analysis, the AT:GC ratio of all the chromosomes was remarkably similar, in striking contrast to mammalian flow karyotypes.
We speculate about a fundamental difference in organization and homogenization of DNA sequences between chromosomes within
mammalian and plant genomes.
Received: 24 April 1996 / Accepted: 24 May 1996 相似文献
175.
以聚丙烯酰胺凝胶电泳方法测定了331例辽宁满族新生儿脐带血血红蛋白F中Gγ/Aγ比值。结果显示:高Gγ(>80%)者4例,占1.21%,其基因频率(f)为0.00604,低Gγ(30-48%)者6例,占1.81%,其基因频率为0.00906,其余正常,Gγ平均值为65.23±6.38%。未发现AγT链。对其中八例异常者(4例高Gγ值,4例低Gγ值)的染色体DNA进行了基因图谱分析,确定4例高Gγ值者基因型有两种:Gγ-Gγ/Gγ-Aγ二例,Gγ-AGγ-Aγ/Gγ-Aγ二例;4例低Gγ值者基因型有二种,分别为:Aγ-Aγ/Gγ-Aγ二例和-GAγ/Gγ-Aγ二例。其中Aγ-Aγ基因型在中国人群中未见报道过。 相似文献
176.
177.
Loiselle DR Thelin WR Parker CE Dicheva NN Kesner BA Mocanu V Wang F Milgram SL Warren MR Borchers CH 《Journal of proteome research》2005,4(3):992-997
In this work, a method for improved protein identification of low-abundance proteins using unstained gels, in combination with robotics and matrix-assisted laser desorption/ionization tandem mass spectrometry, has been developed and evaluated. Omitting the silver-staining process resulted in increased protein identification scores, an increase in the number of peptides observed in the MALDI mass spectrum, and improved quality of the tandem mass spectrometry data. 相似文献
178.
Vibrational optical coherence elastography (OCE) is a promising tool for extracting the mechanical property of soft tissue. Purpose of this study is focusing on settling the optimal frequency range for vibrational OCE with evenly distributed stress filed. A finite element model of 2% agar phantom was built by ANSYS with a vibration stimulation frequency range from 200 to 3000 Hz. Practical experiments were carried out for cross‐validation with the same frequencies and sample. Lateral and horizontal stress filed distributions under different frequencies were mathematically evaluated by coefficient of variance and degree of linearity. Results from simulation and practical experiment cross‐validated each other and 1000 Hz was set as the maximum ideal frequency for vibrational OCE, while the minimum frequency is set by theoretical calculation with a result of 250 Hz. An ex vivo biological sample was utilised to testify performance of vibrational OCE with excitation frequencies in and out of concluded optimal range, which showed that stiffness was better mapped out in optimal frequency range. 相似文献
179.
180.
W. Y. Chan T. B. Ng Joyce S. Y. Lam Jack H. Wong K. T. Chu P. H. K. Ngai S. K. Lam H. X. Wang 《Applied microbiology and biotechnology》2010,85(4):985-993
Earlier investigations disclose that some plant ribosome-inactivating proteins (RIPs) adversely affect mouse embryonic development.
In the present study, a mushroom RIP, namely lyophyllin from Lyophyllum shimeji, was isolated, partially sequenced, and its translation inhibitory activity determined. Its teratogenicity was studied by
using a technique entailing microinjection and postimplantation whole-embryo culture. It was found that embryonic abnormalities
during the period of organogenesis from E8.5 to E9.5 were induced by lyophyllin at a concentration as low as 50 μg/ml, and
when the lyophyllin concentration was raised, the number of abnormal embryos increased, the final somite number decreased,
and the abnormalities increased in severity. The affected embryonic structures included the cranial neural tube, forelimb
buds, branchial arches, and body axis, while optic and otic placodes were more resistant. Lyophyllin at a concentration higher
than 500 μg/ml also induced forebrain blisters within the cranial mesenchyme. When the abnormal embryos were examined histologically,
an increase of cell death was found to be associated with abnormal structures, indicating that cell death may be one of the
underlying causes of teratogenicity of the mushroom RIP. This constitutes the first report on the teratogenicity of a mushroom
RIP. 相似文献