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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. |
- Jacobson, Annica, 1974-
(författare)
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Regulation of hyaluronan biosynthesis : Expression in vitro and importance for tumor progression
- 2002
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Hyaluronan, a component of the extracellular matrix, is synthesized by either of three hyaluronan-synthesizing enzymes termed Has1, Has2 and Has3. The expression level of each Has gene varies between cell types of mesenchymal origin and is differentially regulated in response to external stimuli. For example, stimulation of mesothelial cells with PDGF-BB induced an up-regulation of the Has2 gene, whereas the Has1 and Has3 genes remained unaffected. The induction of Has2 gene expression correlated well with increased Has2 protein levels and accumulation of hyaluronan. Moreover, treatment of mesothelial cells with hydrocortisone suppressed hyaluronan synthesis in cell culture primarily through down-regulation of the Has2 gene. Thus, among the Has isoforms, Has2 seems to be most markedly regulated in response to external stimuli.In an attempt to investigate the importance of hyaluronan in tumor progression, the hyaluronan synthesizing enzyme Has2 and the hyaluronan degrading enzyme Hyal1 were over-expressed in a rat colon adenocarcinoma cell line, PROb. We found that Has2 gene over-expression in colon carcinoma cells promoted cell growth in vitro and progression of transplantable tumors. In contrast, over-expression of Hyal1 lead to a considerable reduction of growth rates both in vivo and in vitro. A linear correlation between tumor growth rate and hyaluronan amount in tumor tissue was observed. In another tumor model, experimental anaplastic thyroid carcinoma, the effects of TGF-β inhibition on hyaluronan and collagen contents in tumor xenografts were investigated. We found that inhibition of TGF-β, a stimulator of hyaluronan and collagen synthesis, lead to reduced collagen deposition whereas the hyaluronan levels in stromal tissue only marginally differed. Our results indicate that a high ratio of collagen to hyaluronan may be characteristic of a pathogenic mechanism that leads to elevated interstitual tumor pressure.
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| 3. |
- Johansson, Rolf, et al.
(författare)
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Adaptation of Multi-Joint Movements during Postural Disturbances.
- 2004
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Ingår i: Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference. - 1557-170X. - 0780384393 ; 1, s. 149-152
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Konferensbidrag (refereegranskat)abstract
- The objective was to investigate the adaptation ofthe multi-segmented body movements induced over time byvibratory proprioceptive stimulation of the calf muscles and by galvanic vestibular stimulation. Twelve normal subjects were with eyes open or eyes closed exposed to vibratory stimulation of two different amplitudes and frequencies, or to simultaneously applied galvanic and vibratory stimulation. Multi-input multi-output system identification methods as well as quantitative analysis were applied to the biomechanical experimental data of anteroposterior and lateral body movements and torques induced towards the ground. The immediate adaptive response to the stimulation onset was that the subjects adopted a more rigid posture with coordinated movements of primarily head-shoulder and headhip body segments. The body-movement amplitudes at allmeasured sites as well as the amplitudes of the ground support forces decreased over time as a result of another, somewhat slower adaptation process. The subjects required more time to adapt to a rigid movement pattern when the subjects were simultaneously exposed to both galvanic and vibratorystimulation. Moreover, the accuracy of the MIMO model andcorrelation analysis between measured torque variance andhead; shoulder; hip and knee movement variance suggests thatforce platform recordings reflect both in anteroposterior and lateral direction the body movements at these sites.
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