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931.
microRNAs (miRNAs)是一类功能性非编码RNA,在多种生物过程中具有重要作用.然而,miRNA的表达模式、调控网络以及参与肝纤维化的miRNA仍有待阐明.为了探讨与肝纤维化相关的miRNA及其靶基因的功能,为临床肝纤维化治疗提供理论依据,本研究前期已采用胆管结扎法(BDL)建立大鼠胆汁淤积性肝纤维化模型.从大鼠肝脏中提取总RNA,应用基因芯片技术对胆汁淤积性肝纤维化肝组织中miRNA和mRNA表达谱进行综合分析;结合生物信息方法分析在胆汁淤积性肝纤维化中差异表达miRNA可能的靶基因;实时荧光定量PCR技术检测TGF-β1处理人肝星状细胞LX-2细胞中miR-29a-3p、miR-194-5p和miR-22-3p相对表达水平.结果 表明,与正常肝组织相比,纤维化肝组织中有48个差异表达miRNA (FC>2,P<0.05),其中36个上调,12个下调;筛选出18个预测靶基因参与与纤维化相关的生物过程;TGF-β1处理LX-2细胞中miR-29a-3p、miR-194-5p和miR-22-3p相对表达水平显著下调(P<0.05).本研究筛选的差异表达miRNAs通过调节靶基因的表达在肝纤维化中可能发挥重要作用,将为miRNA在肝纤维化中的作用提供新的见解. 相似文献
932.
Dwarf bamboo species are monocarpic. They flower simultaneously and die after several decades. The type of flowering in the
genus Sasa ranges from sporadic to gregarious. In order to determine whether or not the sporadic flowering of dwarf bamboo is fixed
genetically, we investigated the distribution of clones using eight microsatellite (SSR) loci in a sporadic flowering patch
of Sasa cernua Makino, a major dwarf bamboo species found in central Hokkaido. In May 2006, flowering occurred on 60.5% of living culms
in a 1600 m2 patch. We established a 50 × 10 m study plot in this patch and noted 1267 clumps consisting of 2529 living culms. We investigated
all 1267 clumps and identified six multilocus genotypes as clones using five variable SSR loci. All flowering clumps belonged
to the same clone. On the other hand, non-flowering vegetative clumps were also discovered to be of the same clone. These
data suggest that all flowering culms originated from a single clone of a sporadic flowering patch of S. cernua. Clonal analysis for investigation of sporadic flowering of S. cernua revealed that only a portion of a clone flowers and dies instead of the whole clone. 相似文献
933.
Jurate Savickiene Grazina Treigyte Ceslava Aleksandraviciene Ruta Navakauskiene 《Central European Journal of Biology》2010,5(5):600-612
The biological effects of low-dose radiation have attracted attention, but data are currently insufficient to fully understand
the beneficial role of the phenomenon. In the present study, we have investigated the effects of low doses of gamma-irradiation
alone and in combination with all-trans-retinoic acid (RA) on proliferation, apoptosis and differentiation of the human promyelocytic leukemia HL-60 cells. Changes
in cell behavior and protein expression were determined with the use of light and fluorescent microscopy, immunocytochemical
and Western blot analysis. Low-dose irradiation with 1–100 cGy caused a dose-dependent inhibition of HL-60 cell proliferation,
and induced apoptosis and differentiation to granulocytes with an increase in the number of CD15-positive cells. Pre-irradiation
with 1–100 cGy for 24 h before treatment with RA promoted apoptosis but did not impair RA-induced differentiation. Both processes
were associated with a decrease in the expression of the proliferating cell nuclear antigen (PCNA), BCL-2, c-MYC, and changes
in both cytosolic and nuclear levels of protein tyrosine-phosphorylation as well as protein kinase C alpha or beta isoforms.
These results demonstrate the beneficial role of low-dose irradiation in modulating leukemia cell proliferation, differentiation
and apoptosis. 相似文献
934.
Depth of edge influence of the agricultural-forest landscape boundary,Southwestern China 总被引:2,自引:0,他引:2
The landscape boundary is an important component of a landscape and often plays an indispensable role in regulating ecological
flows. The primary objective of this study was to estimate how far the edge effects on agricultural-forest landscape boundaries
can penetrate into the forest and agricultural field. This will serve as a basis for understanding the interaction between
forest and agricultural fields in the mountainous area of southwestern China and provide scientific basis for the practice
of the policy of “returning agricultural field to forest.” Based on field investigations, three types of boundaries with six
sampling transects were selected. We investigated the soil moisture, soil nutrients and vegetation diversity along the transect
gradient and explored the depth of edge influence (DEI) with moving split-window techniques for analyzing the data. DEI for
soil moisture changed with the seasons, ranging from 6 m in the pepper field to 2 m in the forest during the dry season, and
from 12 m in the pepper field to 2 m in the forest after heavy rain. DEI based on soil organic matter ranged from 1.5 to 10 m
in the forest field, while it was not detected based on other soil nutrient factors. DEI based on vegetation diversity varied
from 4 to 26 m and from 10 to 31 m in the forest and agricultural fields, respectively. These results provide the scientific
basis for the policy “returning agricultural field to forest”. Based on these field observations, reducing human disturbance
and revegetating with natural shrubs and meadows could be more effective for vegetation conservation in terms of soil moisture
and soil nutrient content in the arid valley of the Minjiang River. 相似文献
935.
Fang-fang Zhuan Zhen-feng Zhang Di-ping Xu Yan-hong Si Han-Zhong Wang Ghopur Mijit 《中国病毒学》2007,22(4):316-325
lacZa-mini-attTn7 was inserted into the intergenic region between the gG and gD genes in a PRV bacterial artificial chromosome (BAC) by homologous
recombination in E. coli. The resulting recombinant BAC (pBeckerZF1) was confirmed by PCR and sequencing. Green fluorescent protein (GFP) gene was
then transposed into pBeckerZF1 by transposon Tn7 to generate pBeckerZF2. Recombinant viruses vBeckerZF1 and vBeckerZF2 were
generated by transfection with the corresponding BAC pBeckerZF1 or pBeckerZF2. The titers and cytopathic effect (CPE) observed
for by vBeckerZF1 and vBeckerZF2 was comparable to that of the parental virus vBecker3. vBeckerZF2 was serial passaged for
five rounds in cell culture, and the mini-Tn7 insertion was stably maintained in viral genome. These results show that recombinant
viruses can be rapidly and reliably created by Tn7-mediated transposition. This technology should accelerate greatly the pace
at which recombinant PRV can be generated and, thus, facilitate the use of recombinant viruses for detailed mutagenic studies.
Foundation item: Key technologies R&D program (2006BAD06A01) from the Ministry of Science and Technology of China. 相似文献
936.
A study was performed to validate 3 FMDV 3ABC-I-ELISA kits developed in China for the differentiation of FMDV infected and vaccinated animals. Sets of sera from naive and vaccinated cattle as well as from cattle that had been infected were tested for antibodies against nonstructural proteins (NSPs) of FMDV by commercial diagnosis kits, Ceditest® FMDV-NS (Ceditest® kit), UBI® FMDV NONSTRUCTURAL PROTEIN ELISA DIRECTION INSERT (UBI® kit) and a FMDV 3ABC-I-ELISA kit developed at the Lanzhou Veterinary Research Institute. The test parameters (sensitivity and specificity) of the three kits were determined, and the result obtained from FMD 3ABC-I-ELISA kit was compared with that obtained from two foreign kits. The results indicated that the coincidence rate between the FMDV 3ABC-I-ELISA and Ceditest® kits was 98.05%, and the coincidence rate between the FMDV 3ABC-I-ELISA and UBI® kits was 94.4%; the sensitivity of both Ceditest® and FMDV 3ABC-I-ELISA kit was 100%. However, the sensitivity of the UBI® kit was only 81.8%. With sera from naive or vaccinated non-infected animals, the specificity of all tests exceeded 90%. 相似文献
937.
Pierre-Paul Lizotte Lana E Hanford Jan J Enghild Eva Nozik-Grayck Brenda-Louise Giles Tim D Oury 《BMC developmental biology》2007,7(1):15
Background
The receptor for advanced glycation end products (mRAGE) is associated with pathology in most tissues, while its soluble form (sRAGE) acts as a decoy receptor. The adult lung is unique in that it expresses high amounts of RAGE under normal conditions while other tissues express low amounts normally and up-regulate RAGE during pathologic processes. We sought to determine the regulation of the soluble and membrane isoforms of RAGE in the developing lung, and its expression under hyperoxic conditions in the neonatal lung. 相似文献938.
Guangjie Li Futian Peng Lin Zhang Xingzheng Shi Zhaoyan Wang 《Molecular biology reports》2010,37(2):947-954
Sucrose non-fermenting-1-related protein kinase-1 (SnRK1) plays an important role in metabolic regulation in plant. To understand
the molecular mechanism of amino acids and carbohydrate metabolism in Malus hupehensis Rehd. var. pinyiensis Jiang (Pingyi Tiancha, PYTC), a full-length cDNA clone encoding homologue of SnRK1 was isolated from PYTC by Rapid Amplification
of cDNA Ends (RACE). The clone, designated as MhSnRK1, contains 2063 nucleotides with an open reading frame of 1548 nucleotides. The deduced 515 amino acids showed high identities
with other plant SnRK1 genes. Quantitative real-time PCR analysis revealed this gene was expressed in roots, stems and leaves. Exposing seedlings
to nitrate caused and initial decrease in expression of the MhSnRK1 gene in roots, leaves and stems in short term. Ectopic expression of MhSnRK1 in tomato mainly resulted in higher starch content in leaf and red-ripening fruit than wild-type plants. This result supports
the hypothesis that overexpression of SnRK1 causes the accumulation of starch in plant cells. All the results suggest that
MhSnRK1 may play important roles in carbohydrate and amino acid metabolisms. 相似文献
939.
940.
Most bio-industrial mammalian cells are cultured in serum-free media to achieve advantages, such as batch consistency, suspended growth, and simplified purification. The successful development of a serum-free medium could contribute to a reduction in the experimental variation, enhance cell productivity, and facilitate biopharmaceuticals production using the cell culture process. Commercial serum-free media are also becoming more and more popular. However, the cell line secrets its own recombinant product and has special nutritional requirements. How can the composition of the proprietary medium be adjusted to support the specific cell’s metabolism and recombinant protein? This article uses statistical strategies to modify the commercial medium. A design of experiments is adopted to optimize the medium composition for the hybridoma cell in a serum-free condition. The supplements of peptone, ferric citrate, and trace elements were chosen to study their impact on hybridoma growth and antibody production using the response surface methodology. The stimulatory effect of the developed formulation on hybridoma growth was confirmed by the steepest ascent path. The optimal medium stimulated the hybridoma growth and antibody production in three diverse systems: a static plate, an agitated spinner flask, and a hollow fiber reactor. The cells in the developed serum-free medium had a better antibody production as compared to that in the commercial medium in the hollow fiber reactor. Our results demonstrated that the facile optimization for medium and antibody production was successfully accomplished in the hybridoma cells. 相似文献