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排序方式: 共有572条查询结果,搜索用时 31 毫秒
81.
Cukjati D Batiuskaite D André F Miklavcic D Mir LM 《Bioelectrochemistry (Amsterdam, Netherlands)》2007,70(2):501-507
In vivo cell electroporation is the basis of DNA electrotransfer, an efficient method for non-viral gene therapy using naked DNA. The electric pulses have two roles, to permeabilize the target cell plasma membrane and to transport the DNA towards or across the permeabilized membrane by electrophoresis. For efficient electrotransfer, reversible undamaging target cell permeabilization is mandatory. We report the possibility to monitor in vivo cell electroporation during pulse delivery, and to adjust the electric field strength on real time, within a few microseconds after the beginning of the pulse, to ensure efficacy and safety of the procedure. A control algorithm was elaborated, implemented in a prototype device and tested in luciferase gene electrotransfer to mice muscles. Controlled pulses resulted in protection of the tissue and high levels of luciferase in gene transfer experiments where uncorrected excessive applied voltages lead to intense muscle damage and consecutive loss of luciferase gene expression. 相似文献
82.
Use of multiplex PCR and CE for gene dosage quantification and its biomedical applications for SMN, PMP22, and alpha-globin genes 总被引:1,自引:0,他引:1
Hung CC Chien SC Lin CY Chang CH Chang YF Jong YJ Hsieh ST Hsieh WS Liu MS Lin WL Lee CN Su YN 《Electrophoresis》2007,28(16):2826-2834
Many genetic diseases are caused by the presence of point mutations, small insertions, and deletions in respective genes, and the number of diseases known to be caused by deletions and duplications involving large DNA genomes is increasing. These changes lead to underexpression or overexpression of the gene, according to changes in gene dosage. The methods for the detection of point mutations, small insertions, and deletions are well established, but the detection of larger genomic deletions or duplications is more difficult. Due to the lack of efficient and technically feasible protocols for gene dosage quantification, we describe a diagnostic protocol employing a combination of available methods. The efficient and accurate gene dosage quantification platform is combined with multiplex PCR and CE, and applied to detect dosages of several genes, including SMN, PMP22, and alpha-globin genes. The reliability of this novel methodology shows that it is a relatively speedy and low-cost procedure and a significant tool for genetic diagnosis. Its sensitivity and specificity for identifying deletion and duplication genotypes approach 100%. Moreover, once we establish this powerful system, we will further apply this technique to the rapid detection of trisomy syndromes and microdeletion syndromes, including trisomy 13, Down syndrome, DiGeorge syndrome, and others. 相似文献
83.
Ammonium is a toxic waste product that has been reported to negatively inhibit cell growth and recombinant glycosylation in
Chinese hamster ovary (CHO) cells; however, the effect of this toxicity on intracellular gene expression has received only
limited investigation. We used a differential display method to identify genes in CHO cells that were affected by ammonium
stress. Eight genes whose mRNA levels significantly changed in response to elevated ammonium were isolated and identified.
Five of the genes were identified as having lower expression under the ammonium stress, whereas three genes were identified
as having higher expression. Sequence homology with other mammalian organisms was used to attribute function to these newly
identified genes. The identified ammonium-sensitive genes were grouped into three broad functional groups: cellular processes,
energy metabolism, and genetic-information processing. The three cellular process-related genes had lower expression (anaphase-promoting
complex subunit 5, eukaryotic initiation factor 5A II, KIAA1091 protein). The two energy-related genes had higher expression
under ammonium stress (adenosine triphosphate synthase subunit C and mitofusin 1). Both of the genetic information-processing
genes (endoplasmic reticulum [ER]-resident protein ERdj5 and structure-specific recognition protein 1) had lower expression
under the ammonium stress, whereas the 26S proteasome subunit adenosine triphosphatase 3 gene had higher expression. These
preliminary results indicate that ammonium stress lowers expression of genes controlling cell cycle, protein folding, and
quality and raises genes that control energy metabolism and degradation. Our findings demonstrate the usefulness of mRNA differential-display
techniques for the detection of CHO cell genes affected by ammonium stress. 相似文献
84.
85.
N,N,N-Trimethylchitosan chloride with different degrees of quaternization has been synthesized and characterized by (1)H NMR spectroscopy. The particle size ranges from 150 to 600 nm, which is dependent on the N/P ratio and is less influenced by the degree of quaternization. The majority of the particles have a spherical morphology. The zeta potential of the particles increases with the N/P ratio and the quaternization degree of TMC. Short-term contact experiments show good biocompatibility of TMC, but long-term contact experiments reveal its high toxicity. This study suggests that TMC is a promising gene carrier, but further modification is still required to improve its cytocompatibility. 相似文献
86.
The mutual responses of higher plants to environment: physiological and microbiological aspects 总被引:3,自引:0,他引:3
Gang W Zhen-Kuan W Yong-Xiang W Li-Ye C Hong-Bo S 《Colloids and surfaces. B, Biointerfaces》2007,59(2):113-119
Higher plants are different from animals in many aspects, but the important difference may be that plants are more easily influenced by environment. Plants have a series of fine mechanisms for responding to environmental changes, which has been established during their long-period evolution and artificial domestication. The relationship between higher plants and environment is influenced mutually. The component in environment provides higher plants with nutrients for shaping themselves and higher plants simultaneously bring photosynthetic products and metabolites to surroundings, which is the most important part of natural circle. Photosynthetic products are realized mainly by physiological mechanisms, and microbiological aspects in environment (for instance, soil environment) impact the above processes greatly. The complete understanding of the relationship will extremely promote the sustainable utilization of plant resources and make the best use of its current potential under different scales. 相似文献
87.
合成了带正电荷密度不同的聚离子亚基化合物,探讨了聚合物结构对外源基因转染真核细胞的影响规律。从实验结果看,聚离子亚基化合物结构影响外源基因转染效率,但其影响程度与靶细胞的种类相关,对HeLa细胞,NIH3T3细胞,聚离子亚基化合物的正电荷密度加大,其促基因转移功能加强;而对PA317包装细胞,结果相反。 相似文献
88.
Andreas Humeny 《Chemie in Unserer Zeit》2003,37(6):380-387
The high accuracy, molecular resolution and sensitivity of matrix‐assisted laser desorption/ionisation time‐of‐flight mass spectrometry (MALDI‐TOF‐MS) make it an efficient method for analysing all kinds of biomolecules including nucleic acids, proteins/peptides, carbohydrates and lipids. MALDI‐TOF‐MS based high‐throughput genotyping of genetic heterogeneities possesses the potential of becoming a routine method. MAL‐DI‐TOF‐MS can be used for the identification of proteins and posttranslational modifications. Taken together, MALDI‐TOF‐MS represents a integrated platform technology in bioanalytics and molecular medicine. 相似文献
89.
90.
Christof M. Niemeyer Dietmar Blohm 《Angewandte Chemie (International ed. in English)》1999,38(19):2865-2869
The complete human genes (ca. 100 000) as well as the whole spectrum of biological diversity should soon be able to be analyzed simultaneously by means of DNA microarrays using the fast technical advances that are occurring in this area. The particular strength of array analysis, typically based on the hybridization of nucleic acid probes attached to microchips with labeled RNA or DNA samples, results from the highly redundant measurement of many parallel hybridization events (see picture), which leads to an extraordinary level of assay validation. 相似文献