1. |
|
|
2. |
|
|
3. |
- Hedin, J., et al.
(author)
-
The influence of non-standard orbits on ICRH power deposition in tokamaks
- 2000
-
In: Nuclear Fusion. - : IOP Publishing. - 0029-5515 .- 1741-4326. ; 40:11, s. 1819-1824
-
Journal article (peer-reviewed)abstract
- The distribution function and power deposition during ICRH in a tokamak plasma are analysed. The importance of self-consistent calculations and the formation of son-standard drift orbits are addressed. It is found that for high power ICRH, the presence of non-standard orbits are crucial for describing the distribution function. For a standard minority heating scenario with the ion cyclotron resonance located at the high field side, the absorption of the wave power is shifted to the low field side (LFS) because of the orbit topology and the evolving wave field profile. The high energy tail of the distribution function of the resonating ions is found to be dominated by ions in passing orbits, of which some reside completely on the LFS of the tokamak.
|
|
4. |
|
|
5. |
|
|
6. |
- Rask, Katarina, 1966, et al.
(author)
-
Increased expression of the transcription factors CCAAT-enhancer binding protein-beta (C/EBBeta) and C/EBzeta (CHOP) correlate with invasiveness of human colorectal cancer.
- 2000
-
In: International journal of cancer. Journal international du cancer. - 0020-7136. ; 86:3, s. 337-43
-
Journal article (peer-reviewed)abstract
- Regulation of cell differentiation is most often impaired in malignant tumors and may represent a key mechanism for the progression of the disease. CCAAT-enhancer binding protein (C/EBP) is a family of transcription factors involved in the regulation of embryonic gut development in rodents, which has also been detected in various malignancies, e.g., liposarcomas and breast and ovarian epithelial tumors. We studied the relationship between C/EBP and tumor histology (Duke's invasive stage and pathological grade) in colorectal cancer. Immunoblotting techniques were used on microdissected fresh frozen tumor specimens, and expression of C/EBPalpha, C/EBPbeta and C/EBPzeta (CHOP) was analyzed in addition to that of the cell-cycle regulator p53 and the proliferation marker PCNA. Expression of C/EBPbeta (LAP isoforms) was markedly increased in all tumors compared with normal colon mucosa. Although the inter-patient variability was large, we found that LIP, the isoform of C/EBPbeta known to inhibit transcription, was expressed at higher levels in Duke's stage B tumors compared with Duke's stage A, whereas Duke's C tumors had the lowest LIP expression. A similar relationship was seen for CHOP. The cell-cycle regulator gene p53 was the only factor that clearly correlated with pathological grade: a decrease in p53 expression was demonstrated. Our data suggest that genetic and cellular events involving C/EBPbeta and CHOP are important for tumor invasion and that these events do not appear to be related to the pathological grade of the tumor.
|
|
7. |
- Sundfeldt, Karin, 1962, et al.
(author)
-
E-cadherin-catenin complex in the rat ovary: cell-specific expression during folliculogenesis and luteal formation.
- 2000
-
In: Journal of reproduction and fertility. - : Bioscientifica. - 0022-4251. ; 118:2, s. 375-85
-
Journal article (peer-reviewed)abstract
- The cadherins and their cytoplasmic counterparts, the catenins, form the adherens junctions, which are of importance for tissue integrity and barrier functions. The development and maturation of the ovarian follicle is characterized by structural changes, which require altered expression or function of the components involved in cell-cell contacts. The present study examined the cell-specific localization and temporal expression of epithelial cadherin (E-cadherin) and alpha- and beta-catenin during follicular development, ovulation and corpus luteum formation in the immature gonadotrophin- and oestrogen-stimulated rat ovary. Immunohistochemistry and immunoblotting demonstrated the expression of E-cadherin in theca and interstitial cells of immature ovaries before and after injection of equine chorionic gonadotrophin (eCG). E-cadherin was not detected in granulosa cells, except in the preantral follicles located to the inner region of the ovary. The content of E-cadherin in theca and interstitial cells decreased after an ovulatory dose of hCG. Granulosa cells of apoptotic follicles did not express E-cadherin. Oestrogen treatment (diethylstilboestrol) of immature rats for up to 3 days did not result in a measurable expression of E-cadherin in granulosa cells. alpha- and beta-catenin were expressed in all ovarian compartments. The concentration of beta-catenin was constant during the follicular phase, whereas the content of alpha-catenin decreased in granulosa cells after treatment with diethylstilboestrol or hCG. The expression of alpha-catenin was also reduced in theca and interstitial cells after hCG. alpha- and beta-catenin were present in most ovarian cells at all stages of folliculogenesis. Therefore, the catenins have the potential to associate with different members of the cadherin family and to participate in the regulation of cytoskeletal structures and intracellular signalling. The restricted expression of E-cadherin in granulosa cells of preantral follicles indicates a role in the recruitment of these follicles to subsequent cycles. The specific decrease of alpha-catenin in granulosa cells and the reduction of both alpha-catenin and E-cadherin in theca cells of ovulatory follicles might reflect some of the molecular changes in cell-cell adhesion associated with ovulation and luteinization.
|
|