| 1. |
|
|
| 2. |
- Jin, Yuesheng, et al.
(författare)
-
Cytogenetic and fluorescence in situ hybridization characterization of clonal chromosomal aberrations and CCND1 amplification in esophageal carcinomas
- 2004
-
Ingår i: Cancer Genetics and Cytogenetics. - 0165-4608. ; 148:1, s. 21-28
-
Tidskriftsartikel (refereegranskat)abstract
- Cytogenetic analyses of four squamous cell carcinomas (SCC) of the esophagus showed complex numerical and structural abnormalities. Chromosomal bands or regions preferentially involved were 11q13, 8q10, 21q10, 3p10similar top11, 1p11similar toq11, 5p11similar toq11, and 14p11similar toq11. For the first time, to our knowledge, recurrent aberrations were identified in esophageal SCC, including homogenous staining region (hsr), isochromosomes i(3q) and i(21q), and ring chromosome. Losses of chromosomal material dominated over gains. Recurrent imbalances included under-representation of 4p13similar topter, 5q14similar toqter, 9p22similar topter, 10p, 11p13similar topter, 12p13similar topter, 17p10similar topter, 18p11similar topter, 21p, and 22p, as well as over-representation of 1q25similar toqter, 3q, 7q, and 8q. Interestingly, hsr at different chromosomal regions occur-red in three of four cases. With the application of fluorescence in situ hybridization (FISH) and multicolor combined binary ratio labeling-FISH with specific DNA probes, it could be shown that in two cases the hsr was derived from chromosome 11 material and that the amplicon included CCND1. Our results, together with previous molecular genetic findings, indicate that CCND1 might be a prime target in 11q13 amplification, and that amplification of this gene might be crucial in the tumorigenesis of esophageal SCC. These observed chromosomal aberrations and imbalances thus provide important information for further molecular genetic investigation of esophageal SCC. (C) 2004 Elsevier Inc. All rights reserved.
|
|
| 3. |
- Jin, Yuesheng, et al.
(författare)
-
Cytogenetic and molecular genetic characterization of immortalized human ovarian surface epithelial cell lines: consistent loss of chromosome 13 and amplification of chromosome 20
- 2004
-
Ingår i: Gynecologic Oncology. - : Elsevier BV. - 1095-6859 .- 0090-8258. ; 92:1, s. 183-191
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives. This study aimed at identifying the genetic events involved in immortalization of ovarian epithelial cells, which might be important steps in ovarian carcinogenesis. Methods. The genetic profiles of five human ovarian surface epithelial (HOSE) cell lines immortalized by retroviral transfection of the human papillomavirus (HPV) E6/E7 genes were thoroughly characterized by chromosome banding and fluorescence in situ hybridization (FISH), at various passages pre- and post-crisis. Results. In pre-crisis, most cells had simple, non-clonal karyotypic changes. Telomere association was the commonest aberration, suggesting that tolermase dysfunction might be an important genetic event leading to cellular crisis. After immortalization post-crisis, however, the karyotypic patterns were non-random. Loss of genetic materials was a characteristic feature. The commonest numerical aberrations were -13, -14, -16, -17, -18, and +5. Among them, loss of chromosome 13 was common change observed in all lines. The only recurrent structural aberration was homogeneously staining regions (hsr) observed in three lines. FISH and combined binary ratio labeling (COBRA)-FISH showed in two cases that the lists were derived from chromosome 20. Clonal evolution was observed in four of the lines. In one line, hsr was the only change shared by all subclones, suggesting that it might be a primary event in cell immortalization. Conclusion. The results of the present study suggested that loss of chromosome 13 and the amplification of chromosome 20 might be early genetic events involved in ovarian cell immortalization, and might be useful targets for the study of genomic aberrations in ovarian carcinogenesis. (C) 2003 Elsevier Inc. All rights reserved.
|
|
| 4. |
- Zhang, H, et al.
(författare)
-
Sequential cytogenetic and molecular cytogenetic characterization of an SV40T-immortalized nasopharyngeal cell line transformed by Epstein-Barr virus latent membrane protein-1 gene
- 2004
-
Ingår i: Cancer Genetics and Cytogenetics. - : Elsevier BV. - 0165-4608. ; 150:2, s. 144-152
-
Tidskriftsartikel (refereegranskat)abstract
- Cytogenetic and molecular cytogenetic analyses were performed on four sublines derived from a newly established, SV40T-immortalized nasopharyngeal (NP) cell line, NP69, with two of the sublines expressing LMP1, an Epstein-Barr virus-encoded gene. A total of seven cytogenetically related subclones were identified, all having highly complex karyotypes with massive numerical and structural rearrangements. Centromeric rearrangements in the form of isochromosomes and whole-ann translocations were prevalent. A cytogenetic sign of gene amplification [i.e., homogeneously staining region (HSR)] was detected at 1q25 in all metaphase cells analyzed. Multicolor combined binary ratio labeling fluorescence in situ hybridization (COBRA-FISH) was used to confirm the karyotypic interpretations. Furthermore, multicolor COBRA-FISH also showed that part of the HSR contained chromosome 20 material. Extensive clonal evolution could be observed by the assessment of karyotypic variation among different subclones and individual metaphase cells. The evaluation of clonal evolution enabled the identification of the temporal order of chromosome aberrations during cell immortalization and malignant transformation. A striking karyotypic similarity was found between sublines expressing LMP1 and an NP carcinoma cell line, with loss of genetic material from chromosome arm 3p being an important recurrent observation. More interestingly, the karyotypic features of NP69 were also similar to those of many epithelial malignancies. Our observations suggest that serial transformation of NP cell lines might provide a useful in vitro model for the study of the multistep neoplastic transformation of NP cells.
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
- Leon, Rosa, et al.
(författare)
-
Dislocation-induced spatial ordering of InAs quantum dots : Effects on optical properties
- 2002
-
Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 91:9, s. 5826-5830
-
Tidskriftsartikel (refereegranskat)abstract
- Misfit dislocations were used to modify the surface morphology and to attain spatial ordering of quantum dots (QDs) by molecular beam epitaxy. Effects of anneal time and temperature on strain-relaxed InxGa1-xAs/GaAs layers and subsequent spatial ordering of InAs QDs were investigated. Photoluminescence (PL) and time-resolved PL was used to study the effects of increased QD positional ordering, increased QD uniformity, and their proximity to dislocation arrays on their optical properties. Narrower inhomogeneous PL broadening from the QDs ordered on dislocation arrays were observed, and differences in PL dynamics were found.
|
|
| 9. |
- Zhang, Jin, et al.
(författare)
-
The effect of charge density and hydrophobic modification on dextran-based paper strength enhancing polymers
- 2000
-
Ingår i: Nordic Pulp & Paper Research Journal. - 0283-2631 .- 2000-0669. ; 15:5, s. 440-445
-
Tidskriftsartikel (refereegranskat)abstract
- The dry tensile strengths of bleached kraft pulp handsheets were measured as functions of the cationic charge density and hydrophobic substituents on 2 million Dalton dextran adsorbed onto the fibers before sheet making. The charge density controlled the maximum amount of dextran that could be adsorbed by the fibers which, in turn, influenced tensile strength. The lower the charge density, the higher were both the dextran adsorption capacity of fibers and the tensile strength of the resulting paper. Butanoic and hexanoic acid when condensed onto dextran gave hydrophobic domains which lowered paper strength linearly with hydrophobic content. An extension to the Page equation gave a semi-empirical model which predicted the major effects of hydrophobic substitution on paper strength.
|
|
| 10. |
- Zhang, X. L., et al.
(författare)
-
Automatic real-time control for gain-flattened fiber Raman amplifiers
- 2004
-
Ingår i: Optics Communications. - : Elsevier BV. - 0030-4018 .- 1873-0310. ; 239:01-3, s. 79-84
-
Tidskriftsartikel (refereegranskat)abstract
- An automatic control algorithm for flattening the gain of a fiber Raman amplifier is derived from the Raman scattering equations. A pseudo-inverse gain matrix is introduced to adjust the powers of the pump lasers. The algorithm is simple, fast, effective, robust and insensitive to the length and type of the fiber. It is demonstrated experimentally that the gain flattening for Raman amplifiers comprising various types and lengths of fiber and with different target gains can be achieved automatically with this algorithm. The algorithm converges for both small and large input signal. Flattened Raman gain with a fluctuation less than 0.40 dB over a 50-nm bandwidth for a 50-km SMF or less than 0.20 dB over a 40-nm bandwidth for a 6.6-km dispersion compensated fiber is realized in the experiment.
|
|
