1. |
|
|
2. |
- Dam, Gitte, et al.
(author)
-
Prospective Study of Chromogranin A as a Predictor of Progression in Patients with Pancreatic, Small-Intestinal, and Unknown Primary Neuroendocrine Tumors
- 2020
-
In: Neuroendocrinology. - : S. Karger AG. - 0028-3835 .- 1423-0194. ; 110:3/4, s. 217-224
-
Journal article (peer-reviewed)abstract
- Background: Retrospective studies are conflicting but most of them report that an increase in plasma chromogranin A (CgA) predicts tumor progression in neuroendocrine tumor (NET) patients. Prospectively, we investigated if a change in plasma CgA is associated with tumor burden changes in NET patients with disseminated disease. Methods: We included 239 patients treated at 5 NET centers from December 2010 to December 2013. CgA was measured within 6 weeks of a CT or MRI in a patient undergoing at least 2 scan examinations performed over a period of 1-24 months. In a post hoc analysis, CgA measured 3-6 months prior to the CT/MRI was analyzed. Changes in tumor size were evaluated by RECIST1.1. A 25% change in CgA was chosen to discriminate between increased, decreased, or unchanged levels. Results: In 671 events (2 CT/MRI scans and 2 corresponding CgA measurements), we found a weak positive correlation between the RECIST 1.1 responses and change in plasma CgA from baseline (Spearman's rank correlation coefficient: 0.15; p < 0.05). Of 304 events in the post hoc analysis, 58 showed progression, 228 showed stable disease, and 18 showed regression, with a median change in CgA of 19% (IQR: 57 to -20%), -12% (23 to -38%), and -73% (-55 to -83%), respectively. The correlation coefficient for all sites was 0.17 (p = 0.003), and it was 0.16 (p = 0.07), 0.18 (p = 0.04), and 0.20 (p = 0.21) for small-intestinal (n = 137), pancreatic (n = 123), and unknown primary NET (n = 40), respectively. In the 58 patients showing tumor progression, the sensitivity and specificity of an increased CgA concentration were 36 and 82%, respectively, with positive and negative predictive values of 32 and 85%. Conclusions: In this prospective study of gastroenteropancreatic NET patients, we observed only a weak association between a change in plasma CgA and changes in tumor burden. CgA as a single biomarker was thus inadequate to predict tumor progression.
|
|
3. |
- Fortes-Lima, Cesar A., PhD, 1985-, et al.
(author)
-
Population structure and admixture during the expansion of Bantu-speaking peoples across sub-Saharan Africa
-
Other publication (other academic/artistic)abstract
- The migration of Bantu-speaking groups out of West Africa, thought to have started around 4 000 years ago, is known as the Bantu expansion. This movement of people changed the genetic landscape of sub-equatorial Africa. To investigate the demographic history and population structure in Bantu-speaking populations (BSP), we genotyped 1,740 individuals, including 1,487 Bantu speakers from 143 populations across 13 sub-Saharan African countries. We find patterns of fine-scale population structure that correlate with linguistics and geography. Bantu speakers received significant amounts of admixture through interaction with local groups from the regions that they expanded into. Spatial modeling indicated possible migration corridors during the Bantu-expansion. Inferences based on modern-day genomes, however, need to be supported by ancient DNA studies. We demonstrated the utility of our dataset as an exhaustive modern-day African comparative dataset for ancient DNA studies by comparing our data to published aDNA studies. By gathering the largest set of genome-wide data to date, enriched with new data from previously unsampled regions and people, we shed new light on the intricacies of the Bantu expansion.
|
|
4. |
- Fortes-Lima, Cesar A., PhD, 1985-, et al.
(author)
-
The genetic legacy of the expansion of Bantu-speaking peoples in Africa
- 2024
-
In: Nature. - : Springer Nature. - 0028-0836 .- 1476-4687. ; 625:7995, s. 540-547
-
Journal article (peer-reviewed)abstract
- The expansion of people speaking Bantu languages is the most dramatic demographic event in Late Holocene Africa and fundamentally reshaped the linguistic, cultural and biological landscape of the continent1-7. With a comprehensive genomic dataset, including newly generated data of modern-day and ancient DNA from previously unsampled regions in Africa, we contribute insights into this expansion that started 6,000-4,000 years ago in western Africa. We genotyped 1,763 participants, including 1,526 Bantu speakers from 147 populations across 14 African countries, and generated whole-genome sequences from 12 Late Iron Age individuals8. We show that genetic diversity amongst Bantu-speaking populations declines with distance from western Africa, with current-day Zambia and the Democratic Republic of Congo as possible crossroads of interaction. Using spatially explicit methods9 and correlating genetic, linguistic and geographical data, we provide cross-disciplinary support for a serial-founder migration model. We further show that Bantu speakers received significant gene flow from local groups in regions they expanded into. Our genetic dataset provides an exhaustive modern-day African comparative dataset for ancient DNA studies10 and will be important to a wide range of disciplines from science and humanities, as well as to the medical sector studying human genetic variation and health in African and African-descendant populations.
|
|
5. |
- Lyttkens, Kerstin, et al.
(author)
-
Evaluation of the image quality of ink-jet printed paper copies of digital chest radiographs as compared with film : A receiver operating characteristic study
- 1994
-
In: Journal of Digital Imaging. - 0897-1889. ; 7:2, s. 61-68
-
Journal article (peer-reviewed)abstract
- Paper copies of digital radiographs printed with the continuous ink-jet technique have proved to be of a high enough quality for demonstration purposes. We present a study on the image quality of ink-jet printed paper copies of digital chest radiographs, based on receiver operating characteristic (ROC) analysis. Eighty-three digital radiographs of a chest phatom with simulated tumors in the mediastinum and right lund, derived from a computed radiography (CR) system were presented in two series of hard copies as ink-jet printed paper copies and as laser recorded film. The images, with a matrix of 1,760×2,140 pixels, were printed with a spatial resolution of 10 pixels/mm in the CR film recorder as well as in the ink-jet printer. On film, every image was recorded in two versions, one optimized for the mediastinum and one for the lungs. On paper, only one image was printed; this constituted an effort to optimize both the mediastinum and the lungs. The ink-jet printed images, printed on a matt coated paper, were viewed as on-sight images with reflected light. The exdaminations were reviewed by six radiologists, and ROC curves were constructed. No significant difference was found between the performance of film and that of ink-jet paper prints. Because the cost for a paper copy is only a tenth of that of film, remarkable cost reductions can be achieved by using the ink jet technique instead. Our results show that further quality studies of ink-jet printed images are worthwhile.
|
|