| 2. |
- Ohlsson, B., et al.
(författare)
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Detection of hepatic metastases in colorectal cancer : A prospective study of laboratory and imaging methods
- 1993
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Ingår i: European Journal of Surgery, Acta Chirurgica. - 1102-4151. ; 159:5, s. 275-281
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To assess and compare the accuracy of imaging methods (ultrasonography (US), computed tomography (CT), angiography, arterially enhanced CT with computed tomographic arterial portography (CTA)), biochemical analyses, and surgical assessment during the operation, in detecting the presence or absence of hepatic metastases in patients with colorectal cancer. Design: Open study. Setting: University of Lund, Sweden. Subjects: 71 consecutive patients without clinical evidence of liver metastases at the time of the operation for removal of the primary tumour. Interventions: Regular biochemical tests for five to seven years, and CT and US one year after operation in all patients without confirmed metastases. Main outcome measures: Presence or absence of hepatic metastases. Results: Accuracy of surgical assessment, angiography, US, CT and CTA was 90, 77, 80, 82 and 83%, respectively, and corresponding predictive values of a negative test were 87, 75, 77, 80 and 84%. Measurement of bilirubin concentration and hepatic enzyme activities were not helpful, and that of carcinoembryonic antigen had an accuracy of only 70%. Accuracy and predictive values were not improved by combining tests. Conclusion: The accuracy of US, CT or CTA was not good enough to merrit routine use before operations for colorectal cancer. They are potentially valuable for monitoring progress at follow up, but this remains to be confirmed.
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| 4. |
- Ohlsson, M, et al.
(författare)
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Transcriptional regulation of the rat tissue type plasminogen activator gene : localization of DNA elements and nuclear factors mediating constitutive and cyclic AMP-induced expression.
- 1993
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Ingår i: Molecular and Cellular Biology. - 0270-7306 .- 1098-5549. ; 13:1, s. 266-75
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Tidskriftsartikel (refereegranskat)abstract
- We have characterized tissue type plasminogen activator (tPA) promoter elements and nuclear factors required for follicle-stimulating hormone (FSH)-induced transcription of the rat tPA gene in granulosa cells and constitutive expression of the gene in the rat neuroblastoma cell line B103. Run-on transcription analysis of isolated nuclei revealed that B103 cells transcribe the tPA gene at a high and constitutive level, while FSH was found to induce tPA gene transcription in a rapid and transient manner in granulosa cells. The maximal FSH-induced transcription rate was obtained after 20 min and was similar in the absence or presence of the protein synthesis inhibitor cycloheximide. However, in the presence of cycloheximide, tPA transcription was not turned off but continued at a high rate for several hours. This phenomenon may at least partly explain the earlier finding that tPA mRNA is superinduced by FSH in the presence of cycloheximide. DNase I footprinting analysis of the first 621 bp of the tPA promoter revealed a total of six regions that interact with nuclear factors from B103 and granulosa cells. Deletion of the promoter region from positions -269 to -621, a region that includes the two most-upstream footprints, had no effect on constitutive or FSH-induced transcription in transient expression experiments. Nuclear extracts from both granulosa cells and B103 cells showed strong binding to a consensus cyclic AMP-responsive element (CRE) at positions -178 to -185 and a neighboring binding site for nuclear factor 1 (NF1) at positions -145 to -158. The factors binding to these two regions were identified as members of the CRE-binding protein and NF1 families of transcription factors, respectively. Footprints were also obtained over two GC boxes at positions -64 to -71 and -41 to -49. These footprints were more pronounced with nuclear extracts from B103 cells than with extracts from untreated or FSH-treated granulosa cells, but gel shift assays indicate that similar amounts of two distinct factors bind to the two GC boxes in both cell types. Transfection experiments using promoter constructs with inactivated promoter elements indicate that both the CRE and NF1 sites contribute to the FSH responsiveness of the rat tPA gene in granulosa cells, while only the NF1 site is important for constitutive expression in B103 cells. The two GC boxes were found to be necessary both for constitutive expression in B103 cells and for FSH-induced expression in granulosa cells, and inactivation of both GC boxes essentially eliminated the tPA promoter activity in both cell types.
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