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- Scott, David R, et al.
(författare)
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Use of human papillomavirus DNA testing to compare equivocal cervical cytologic interpretations in the United States, Scandinavia, and the United Kingdom
- 2002
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Ingår i: Cancer. - : John Wiley and Sons Inc.. - 1097-0142 .- 0008-543X. ; 96:1, s. 14-20
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Human papillomavirus (HPV) DNA testing may be useful in clarifying equivocal cervical cytologic interpretations. One application might be to standardize the meaning of equivocal interpretations from laboratories in various regions. Because international differences may be particularly marked, international comparisons of emerging data will require clear translations of "equivocal" and similar terms. METHODS: To perform a three-country comparison, the authors selected a morphologically diverse set of 188 conventional Papanicolaou tests initially classified as "squamous atypia" from a study of more than 20,000 women in Portland, Oregon (1989-1990). Previously, five U.S. expert cytopathologists independently interpreted the slides with screening cytotechnologists' marks in place. For this comparison, one British and two Scandinavian reviewers involved in HPV research reviewed the slides after original marks had been removed. The authors compared all eight reviewers' classifications of negative, equivocal, or abnormal in a series of pairwise comparisons using the kappa statistic. They then compared cytologic interpretations with HPV DNA testing. RESULTS: Oncogenic HPV DNA detection was significantly associated with increasingly abnormal interpretations for each reader. The British reader tended to rate tests as more abnormal than the American pathologists did, whereas the Scandinavians tended to rate tests as more normal. Reference to the HPV DNA standard clarified the tendency of readers to render systematically more or less severe interpretations. For example, the Scandinavian cytologists discounted subtle (often HPV-associated) changes in favor of cytologic certainty, making HPV triage of equivocal tests less applicable there. CONCLUSIONS: International research on cytopathology, particularly on the possible uses of HPV DNA testing, will require calibration of local cytologic definitions.
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| 2. |
- White, Eric J., et al.
(författare)
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DNA replication-timing analysis of human chromosome 22 at high resolution and different developmental states
- 2004
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 101:51, s. 17771-17776
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Tidskriftsartikel (refereegranskat)abstract
- Duplication of the genome during the S phase of the cell cycle does not occur simultaneously; rather, different sequences are replicated at different times. The replication timing of specific sequences can change during development; however, the determinants of this dynamic process are poorly understood. To gain insights into the contribution of developmental state, genomic sequence, and transcriptional activity to replication timing, we investigated the timing of DNA replication at high resolution along an entire human chromosome (chromosome 22) in two different cell types. The pattern of replication timing was correlated with respect to annotated genes, gene expression, novel transcribed regions of unknown function, sequence composition, and cytological features. We observed that chromosome 22 contains regions of early- and late-replicating domains of 100 kb to 2 Mb, many (but not all) of which are associated with previously described chromosomal bands. In both cell types, expressed sequences are replicated earlier than nontranscribed regions. However, several highly transcribed regions replicate late. Overall, the DNA replication-timing profiles of the two different cell types are remarkably similar, with only nine regions of difference observed. In one case, this difference reflects the differential expression of an annotated gene that resides in this region. Novel transcribed regions with low coding potential exhibit a strong propensity for early DNA replication. Although the cellular function of such transcripts is poorly understood, our results suggest that their activity is linked to the replication-timing program.
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