| 1. |
- Yu, Ling-Zhu, et al.
(author)
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MEK1/2 regulates microtubule organization, spindle pole tethering and asymmetric division during mouse oocyte meiotic maturation.
- 2007
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In: Cell cycle (Georgetown, Tex.). - 1551-4005. ; 6:3, s. 330-8
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Journal article (peer-reviewed)abstract
- It is well known that MAPK plays pivotal roles in oocyte maturation, but the function of MEK (MAPK kinase) remains unknown. We have studied the expression, subcellular localization and functional roles of MEK during meiotic maturation of mouse oocytes. Firstly, we found that MEK1/2 phoshorylation (p-MEK1/2, indicative of MEK activation) was low in GV (germinal vesicle) stage, increased 2h after GVBD (germinal vesicle breakdown), and reached the maximum at metaphase II. Secondly, we found that P-MEK1/2 was restricted in the GV prior to GVBD. In prometaphase I and metaphase I, P-MEK1/2 was mainly associated with the spindle, especially with the spindle poles. At anaphase I and telophase I, p-MEK1/2 became diffusely distributed in the region between the separating chromosomes, and then became associated with the midbody. The association of p-MEK1/2 with spindle poles was further confirmed by its colocalization with the centrosomal proteins, gamma-tubulin and NuMA. Thirdly, we have investigated the possible functional role of MEK1/2 activation by intravenous administration and intrabursal injection of a specific MEK inhibitor, U0126, and by microinjection of MEK siRNA into oocytes. All these manipulations cause disorganized spindle poles and spindle structure, misaligned chromosomes and larger than normal polar bodies. Our results suggest that MEK1/2 may function as a centrosomal protein and may have roles in microtubule organization, spindle pole tethering and asymmetric division during mouse oocyte maturation.
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| 2. |
- Liu, Wen-Chun, et al.
(author)
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Genotyping of Hepatitis B Virus - Genotypes A to G by Multiplex Polymerase Chain Reaction
- 2008
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In: Intervirology. - : S. Karger AG. - 0300-5526 .- 1423-0100. ; 51:4, s. 247-252
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Journal article (peer-reviewed)abstract
- <i>Objectives:</i> Eight genotypes (A–H) of hepatitis B virus (HBV) are known with variations in nucleotide sequences greater than 8%. Several recent publications found that the clinical course and outcome of antiviral therapy depended on the genotype of the infecting HBV strain. Large epidemiological studies will require the availability of a system which is rapid, reliable and can be performed on a large number of samples. <i>Methods:</i> To establish a simple and accurate genotyping method, the study collected 369 HBV complete genomic sequences from the GenBank database. Type-specific primers were also designed that separated HBV genotypes A to G by multiplex polymerase chain reaction. <i>Results:</i> By comparison with the traditional restriction fragment length polymorphism method, over 93% of 441 samples were accurately genotyped by current assay, with a higher detection rate and sensitivity to detect mixed HBV infections. <i>Conclusions:</i> This methodology can be applied only to areas prevalent with HBV genotypes A to G. However, it provides an efficient alternative for clinical diagnosis and large-scale studies.
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| 3. |
- Liu, Wen-Chun, et al.
(author)
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Simultaneous quantification and genotyping of hepatitis B virus for genotypes A to G by real-time PCR and two-step melting curve analysis.
- 2006
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In: Journal of clinical microbiology. - 0095-1137. ; 44:12, s. 4491-7
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Journal article (peer-reviewed)abstract
- Both the viral titer and the genotype significantly determine clinical outcomes and responses to antiviral treatment in chronic hepatitis B virus (HBV) infection. A method was developed for large-scale A-to-G genotyping with simultaneous viral quantification. The assay was run on a LightCycler instrument using hybridization probes. The genotype was determined from the melting points of the probes in a two-step manner. Set 1 amplicons differentiated genotypes B, E, and F from A, C, D, and G and simultaneously quantified viremia by real-time PCR. Melting curve analysis using the set 2-1 amplicon or the set 2-2 amplicon reaction mixture was then used to differentiate these genotype groups into single genotypes. HBV DNA quantification was consistent with that of the Amplicor assay and linear in a range from 10(2) to 10(13) copies/ml. By comparison with the restriction fragment length polymorphism method, 92.3% of 441 samples were accurately genotyped by the current assay. The method should be useful for genotyping and quantification of HBV DNA in areas where all genotypes exist.
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