ORCID Profile
0000-0003-1803-0745
Current Organisations
KU Leuven
,
Wildlife Conservation Society
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Publisher: Public Library of Science (PLoS)
Date: 09-05-2019
Publisher: Elsevier BV
Date: 11-2020
Publisher: Oxford University Press (OUP)
Date: 29-06-2022
Abstract: Cell-free DNA (cfDNA) analysis holds great promise for non-invasive cancer screening, diagnosis, and monitoring. We hypothesized that mining the patterns of cfDNA shallow whole-genome sequencing datasets from patients with cancer could improve cancer detection. By applying unsupervised clustering and supervised machine learning on large cfDNA shallow whole-genome sequencing datasets from healthy in iduals (n = 367) and patients with different hematological (n = 238) and solid malignancies (n = 320), we identified cfDNA signatures that enabled cancer detection and typing. Unsupervised clustering revealed cancer type-specific sub-grouping. Classification using a supervised machine learning model yielded accuracies of 96% and 65% in discriminating hematological and solid malignancies from healthy controls, respectively. The accuracy of disease type prediction was 85% and 70% for the hematological and solid cancers, respectively. The potential utility of managing a specific cancer was demonstrated by classifying benign from invasive and borderline adnexal masses with an area under the curve of 0.87 and 0.74, respectively. This approach provides a generic analytical strategy for non-invasive pan-cancer detection and cancer type prediction.
Publisher: Wiley
Date: 11-2019
DOI: 10.1002/AJUM.12177
Publisher: Elsevier BV
Date: 12-2020
Publisher: Springer Science and Business Media LLC
Date: 08-2019
DOI: 10.1038/S41556-019-0360-Z
Abstract: Endometrial disorders represent a major gynaecological burden. Current research models fail to recapitulate the nature and heterogeneity of these diseases, thereby h ering scientific and clinical progress. Here we developed long-term expandable organoids from a broad spectrum of endometrial pathologies. Organoids from endometriosis show disease-associated traits and cancer-linked mutations. Endometrial cancer-derived organoids accurately capture cancer subtypes, replicate the mutational landscape of the tumours and display patient-specific drug responses. Organoids were also established from precancerous pathologies encompassing endometrial hyperplasia and Lynch syndrome, and inherited gene mutations were maintained. Endometrial disease organoids reproduced the original lesion when transplanted in vivo. In summary, we developed multiple organoid models that capture endometrial disease ersity and will provide powerful research models and drug screening and discovery tools.
Publisher: Public Library of Science (PLoS)
Date: 29-03-2021
DOI: 10.1371/JOURNAL.PONE.0248294
Abstract: With increasing livestock numbers, competition and avoidance are increasingly shaping resource availability for wild ungulates. Shifts in the dietary niche of wild ungulates are likely and can be expected to negatively affect their fitness. The Mongolian Gobi constitutes the largest remaining refuge for several threatened ungulates, but unprecedentedly high livestock numbers are sparking growing concerns over rangeland health and impacts on threatened ungulates like the Asiatic wild ass (khulan). Previous stable isotope analysis of khulan tail hair from the Dzungarian Gobi suggested that they graze in summer but switch to a poorer mixed C3 grass / C4 shrub diet in winter, most likely in reaction to local herders and their livestock. Here we attempt to validate these findings with a different methodology, DNA metabarcoding. Further, we extend the scope of the original study to the South Gobi Region, where we expect higher proportions of low-quality browse in the khulan winter diet due to a higher human and livestock presence. Barcoding confirmed the assumptions behind the seasonal diet change observed in the Dzungarian Gobi isotope data, and new isotope analysis revealed a strong seasonal pattern and higher C4 plant intake in the South Gobi Region, in line with our expectations. However, DNA barcoding revealed C4 domination of winter diet was due to C4 grasses (rather than shrubs) for the South Gobi Region. Slight climatic differences result in regional shifts in the occurrence of C3 and C4 grasses and shrubs, which do not allow for an isotopic separation along the grazer-browser continuum over the entire Gobi. Our findings do not allow us to confirm human impacts upon dietary preferences in khulan as we lack seasonal s les from the South Gobi Region. However, these data provide novel insight into khulan diet, raise new questions about plant availability versus preference, and provide a cautionary tale about indirect analysis methods if used in isolation or extrapolated to the landscape level. Good concordance between relative read abundance of C4 genera from barcoding and proportion of C4 plants from isotope analysis adds to a growing body of evidence that barcoding is a promising quantitative tool to understand resource partitioning in ungulates.
Publisher: Wiley
Date: 07-02-2022
DOI: 10.1002/IJGO.14097
Abstract: To investigate the association between personal history, anthropometric features and lifestyle characteristics and endometrial malignancy in women with abnormal vaginal bleeding. Prospective observational cohort assessed by descriptive and multivariable logistic regression analyses. Three features—age, body mass index (BMI calculated as weight in kilograms ided by the square of height in meters), and nulliparity—were defined a priori for baseline risk assessment of endometrial malignancy. The following variables were tested for added value: intrauterine contraceptive device, bleeding pattern, age at menopause, coexisting diabetes/hypertension, physical exercise, fat distribution, bra size, waist circumference, smoking/drinking habits, family history, use of hormonal/anticoagulant therapy, and sonographic endometrial thickness. We calculated adjusted odds ratio, optimism‐corrected area under the receiver operating characteristic curve (AUC), R 2 , and Akaike's information criterion. Of 2417 women, 155 (6%) had endometrial malignancy or endometrial intraepithelial neoplasia. In women with endometrial cancer median age was 67 years (interquartile range [IQR] 56–75 years), median parity was 2 (IQR 0–10), and median BMI was 28 (IQR 25–32). Age, BMI, and parity produced an AUC of 0.82. Other variables marginally affected the AUC, adding endometrial thickness substantially increased the AUC in postmenopausal women. Age, parity, and BMI help in the assessment of endometrial cancer risk in women with abnormal uterine bleeding. Other patient information adds little, whereas sonographic endometrial thickness substantially improves assessment.
Publisher: Wiley
Date: 30-09-2019
DOI: 10.1002/UOG.20427
Publisher: Wiley
Date: 09-2017
DOI: 10.1002/UOG.18109
Publisher: Wiley
Date: 15-09-2022
DOI: 10.1002/UOG.24904
Abstract: To describe the clinical and ultrasound features of ovarian mature cystic teratomas (MCTs). This was a retrospective study. From the International Ovarian Tumor Analysis (IOTA) database, we identified patients with a histologically confirmed diagnosis of MCT who had undergone transvaginal ultrasound examination between 1999 and 2016 (IOTA phases 1, 2, 3 and 5) in one of five centers. Ultrasound was performed by an experienced examiner who used the standardized IOTA examination technique and terminology. In addition to extracting data from the IOTA database, available two‐dimensional grayscale and color or power Doppler images were reviewed retrospectively to identify typical ultrasound features of MCT described previously and detect possible new features using pattern recognition. All images were reviewed by two independent examiners and further discussed with two ultrasound experts to reach consensus. Included in the study were 454 patients with histologically confirmed MCT. Median age was 33 (range, 8–90) years and 66 (14.5%) patients were postmenopausal. Most MCTs were described by the original ultrasound examiner as unilocular (262/454 (57.7%)) or multilocular (70/454 (15.4%)) cysts with mixed echogenicity of cystic fluid (368/454 (81.1%)), acoustic shadowing (328/454 (72.2%)) and no or little vascularization on color Doppler (color score 1, 240/454 (52.9%) color score 2, 123/454 (27.1%)). The median largest lesion diameter was 66 (range, 15–310) mm. A correct preoperative diagnosis of MCT was suggested by the original ultrasound examiner in 372/454 (81.9%) cases. On retrospective review of ultrasound images of 334 MCTs that had quality sufficient for assessment, ‘dots and/or lines’ and/or ‘echogenic white ball’ (typical features according to the literature) were present in 271/334 (81.1%) masses. We identified four new ultrasound features characteristic of MCT: ‘cotton wool tufts’, ‘mushroom cap sign’, ‘completely hyperechogenic lesion’ and ‘starry sky sign’. At least one classical or novel ultrasound feature was present in 315/334 (94.3%) MCTs. Twenty‐nine (8.7%) MCTs manifested vascularized solid tissue, of which seven exhibited no typical features. We provide a comprehensive overview of conventional and newly described ultrasound features of MCTs. Only a small proportion of MCTs did not manifest any of the typical features. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.
Publisher: Springer Science and Business Media LLC
Date: 08-11-2019
DOI: 10.1186/S13048-019-0577-2
Abstract: Epithelial ovarian cancer (EOC) remains the most lethal gynecological cancer in developed countries, indicating the need for further research. Although current cancer models prove useful, they have major limitations. Organoids, a novel in vitro 3D cell culture technique, derived from stem cells, could provide a bridge between the current preclinical platforms. However, this technique is still in its early stages. After conducting a systematic literature search, only sixteen manuscripts concerning ovarian related organoids could be retrieved. In this review, we discuss current tumor models, including organoids and provide a comprehensive review about organoids of ovarian tissue. Potential future applications are addressed, proving organoids to be an interesting platform for modeling tumorigenesis, drug testing and screening and other applications. Recent advancements could usher in a new era of highly personalized medicine in EOC.
Publisher: Wiley
Date: 10-2018
DOI: 10.1002/UOG.20021
Publisher: Wiley
Date: 10-2020
DOI: 10.1002/UOG.22286
Publisher: Frontiers Media SA
Date: 20-04-2021
DOI: 10.3389/FCELL.2021.661472
Abstract: The pelviperineal organs of the female reproductive tract form an essential cornerstone of human procreation. The system comprises the ectodermal external genitalia, the Müllerian upper-vaginal, cervical, endometrial and oviductal derivatives, and the endodermal ovaries. Each of these organs presents with a unique course of biological development as well as of malignant degeneration. For many decades, various preclinical in vitro models have been employed to study female reproductive organ (patho-)biology, however, facing important shortcomings of limited expandability, loss of representativeness and inadequate translatability to the clinic. The recent emergence of 3D organoid models has propelled the field forward by generating powerful research tools that in vitro replicate healthy as well as diseased human tissues and are amenable to state-of-the-art experimental interventions. Here, we in detail review organoid modeling of the different female reproductive organs from healthy and tumorigenic backgrounds, and project perspectives for both scientists and clinicians.
Publisher: Wiley
Date: 30-09-2019
DOI: 10.1002/UOG.20442
Publisher: Wiley
Date: 10-2020
DOI: 10.1002/UOG.23483
Publisher: Wiley
Date: 17-06-2023
DOI: 10.1002/UOG.26293
Publisher: BMJ Publishing Group Ltd
Date: 10-2021
Publisher: Public Library of Science (PLoS)
Date: 22-06-2016
Publisher: Elsevier BV
Date: 07-2023
Publisher: Springer Science and Business Media LLC
Date: 28-04-2022
DOI: 10.1038/S41525-022-00300-5
Abstract: Fragmentation patterns of plasma cell-free DNA (cfDNA) are known to reflect nucleosome positions of cell types contributing to cfDNA. Based on cfDNA fragmentation patterns, the deviation in nucleosome footprints was quantified between diagnosed ovarian cancer patients and healthy in iduals. Multinomial modeling was subsequently applied to capture these deviations in a per s le nucleosome footprint score. Validation was performed in 271 cfDNAs pre-surgically collected from women with an adnexal mass. We confirmed that nucleosome scores were elevated in invasive carcinoma patients, but not in patients with benign or borderline disease. Combining nucleosome scores with chromosomal instability scores assessed in the same cfDNA improved prediction of malignancy. Nucleosome scores were, however, more reliable to predict non-high-grade serous ovarian tumors, which are characterized by low chromosomal instability. These data highlight that compared to chromosomal instability, nucleosome footprinting provides a complementary and more generic read-out for pre-surgical diagnosis of invasive disease in women with adnexal masses.
Publisher: Cold Spring Harbor Laboratory
Date: 20-02-2022
DOI: 10.1101/2022.02.16.22268780
Abstract: Cell-free DNA (cfDNA) analysis holds great promise for non-invasive cancer screening, diagnosis and monitoring. We hypothesized that mining the patterns of big datasets of shallow whole genome sequencing cfDNA from cancer patients could improve cancer detection. By applying unsupervised clustering and supervised machine learning on large shallow whole-genome sequencing cfDNA datasets from healthy in iduals (n=367), patients with different hematological (n=238) and solid malignancies (n=320), we identify cfDNA signatures that enable cancer detection and typing. Unsupervised clustering revealed cancer-type-specific sub-grouping. Classification using supervised machine learning model yielded an overall accuracy of 81.62% in discriminating malignant from control s les. The accuracy of disease type prediction was 85% and 70% for the hematological and solid cancers, respectively. We demonstrate the clinical utility of our approach by classifying benign from invasive and borderline adnexal masses with an AUC of 0.8656 and 0.7388, respectively. This approach provides a generic and cost-effective strategy for non-invasive pan-cancer detection.
Publisher: Elsevier BV
Date: 04-2020
Publisher: Medknow
Date: 2020
Publisher: S. Karger AG
Date: 2022
DOI: 10.1159/000522524
Abstract: b i Objectives: /i /b The aim of this study was to develop a model that can discriminate between different etiologies of abnormal uterine bleeding. b i Design: /i /b The International Endometrial Tumor Analysis 1 study is a multicenter observational diagnostic study in 18 bleeding clinics in 9 countries. Consecutive women with abnormal vaginal bleeding presenting for ultrasound examination ( i n /i = 2,417) were recruited. The histology was obtained from endometrial s ling, D& C, hysteroscopic resection, hysterectomy, or ultrasound follow-up for & #x3e year. b i Methods: /i /b A model was developed using multinomial regression based on age, body mass index, and ultrasound predictors to distinguish between: (1) endometrial atrophy, (2) endometrial polyp or intracavitary myoma, (3) endometrial malignancy or atypical hyperplasia, (4) proliferative/secretory changes, endometritis, or hyperplasia without atypia and validated using leave-center-out cross-validation and bootstrapping. The main outcomes are the model’s ability to discriminate between the four outcomes and the calibration of risk estimates. b i Results: /i /b The median age in 2,417 women was 50 (interquartile range 43–57). 414 (17%) women had endometrial atrophy 996 (41%) had a polyp or myoma 155 (6%) had an endometrial malignancy or atypical hyperplasia and 852 (35%) had proliferative/secretory changes, endometritis, or hyperplasia without atypia. The model distinguished well between malignant and benign histology ( i c /i -statistic 0.88 95% CI: 0.85–0.91) and between all benign histologies. The probabilities for each of the four outcomes were over- or underestimated depending on the centers. b i Limitations: /i /b Not all patients had a diagnosis based on histology. The model over- or underestimated the risk for certain outcomes in some centers, indicating local recalibration is advisable. b i Conclusions: /i /b The proposed model reliably distinguishes between four histological outcomes. This is the first model to discriminate between several outcomes and is the only model applicable when menopausal status is uncertain. The model could be useful for patient management and counseling, and aid in the interpretation of ultrasound findings. Future research is needed to externally validate and locally recalibrate the model.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 26-01-2018
Abstract: Until the past century or so, the movement of wild animals was relatively unrestricted, and their travels contributed substantially to ecological processes. As humans have increasingly altered natural habitats, natural animal movements have been restricted. Tucker et al. examined GPS locations for more than 50 species. In general, animal movements were shorter in areas with high human impact, likely owing to changed behaviors and physical limitations. Besides affecting the species themselves, such changes could have wider effects by limiting the movement of nutrients and altering ecological interactions. Science , this issue p. 466
Publisher: Wiley
Date: 30-09-2019
DOI: 10.1002/UOG.20474
Publisher: Wiley
Date: 08-2022
DOI: 10.1002/UOG.24910
Abstract: The primary aim of this study was to describe the ultrasound features of various endometrial and other intracavitary pathologies in women without abnormal uterine bleeding (AUB) using the International Endometrial Tumor Analysis (IETA) terminology. The secondary aim was to compare our findings with published data on women with AUB. This was a prospective observational study of women presenting at one of seven centers specialized in gynecological ultrasonography, from 2011 until 2018, for indications unrelated to AUB. All patients underwent transvaginal ultrasound using the IETA examination and measurement techniques. Ultrasonography was performed as part of routine gynecological examination or follow‐up of non‐endometrial pathology, or as part of the work‐up before undergoing treatment for infertility, uterine prolapse or ovarian pathology. Ultrasound findings were described using the IETA terminology. Endometrial s ling was performed after the ultrasound scan. The histological endpoints were endometrial atrophy, proliferative or secretory endometrium, endometrial hyperplasia without atypia, endometrial polyp, intracavitary leiomyoma, endometrial intraepithelial neoplasia (EIN), endometrial cancer (EC) and insufficient tissue. The findings in our cohort of women without AUB were compared with those in a published cohort of women with AUB who were examined with transvaginal ultrasound between 2012 and 2015 using the same IETA examination technique and terminology. In this study (IETA3), we included 1745 women without AUB who underwent a standardized transvaginal ultrasound examination followed by either endometrial s ling with histological diagnosis ( n = 1537) or at least 1 year of clinical and ultrasound follow‐up ( n = 208). Of these, 858 (49.2%) women were premenopausal and 887 (50.8%) were postmenopausal. Histology showed the presence of EC and/or EIN in 29 (1.7%) women, endometrial polyps in 1028 (58.9%), intracavitary myomas in 66 (3.8%), proliferative or secretory changes or hyperplasia without atypia in 144 (8.3%), endometrial atrophy in 265 (15.2%) and insufficient tissue in five (0.3%). Most cases of EC or EIN (25/29 (86.2%)) were diagnosed after menopause. The mean endometrial thickness in women with EC or EIN was 11.2 mm (95% CI, 8.9–13.6 mm), being on average 2.4 mm (95% CI, 0.3–4.6 mm) thicker than their benign counterparts. Women with malignant endometrial pathology manifested more frequently non‐uniform echogenicity (22/29 (75.9%)) than did those with benign endometrial pathology (929/1716 (54.1%)) (difference, +21.8% (95% CI, +4.2% to +39.2%)). Moderate to abundant vascularization (color score 3–4) was seen in 31.0% (9/29) of cases with EC or EIN compared with 12.8% (220/1716) of those with a benign outcome (difference, +18.2% (95% CI, –0.5% to +36.9%)). Multiple multifocal vessels were recorded in 24.1% (7/29) women with EC or EIN vs 4.0% (68/1716) of those with a benign outcome (difference, +20.2% (95% CI, +4.6% to +35.7%)). A regular endometrial–myometrial junction was seen less frequently in women with EC or EIN (19/29 (65.5%)) vs those with a benign outcome (1412/1716 (82.3%)) (difference, –16.8% (95% CI, –34.2% to +0.6%)). In women with endometrial polyps without AUB, a single dominant vessel was the most frequent vascular pattern (666/1028 (64.8%)). In women with EC, both in those with and those without AUB, the endometrium usually manifested heterogeneous echogenicity, but the endometrium was on average 8.6 mm (95% CI, 5.2–12.0 mm) thinner and less intensely vascularized (color score 3–4: difference, –26.8% (95% CI, –52.2% to –1.3%)) in women without compared to those with AUB. In both pre‐ and postmenopausal women, asymptomatic endometrial polyps were associated with a thinner endometrium, and they manifested more frequently a bright edge, a regular endometrial–myometrial junction and a single dominant vessel than did polyps in symptomatic women, and they were less intensely vascularized. We describe the typical ultrasound features of EC, polyps and other intracavitary histologies using IETA terminology in women without AUB. Our findings suggest that the presence of asymptomatic polyps or endometrial malignancy may be accompanied by thinner and less intensely vascularized endometria than their symptomatic counterparts. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.
Publisher: Springer Science and Business Media LLC
Date: 06-2020
Publisher: Wiley
Date: 09-2022
DOI: 10.1002/UOG.26015
Publisher: Wiley
Date: 26-07-2021
DOI: 10.1111/ELE.13848
Abstract: The forage maturation hypothesis (FMH) states that energy intake for ungulates is maximised when forage biomass is at intermediate levels. Nevertheless, metabolic allometry and different digestive systems suggest that resource selection should vary across ungulate species. By combining GPS relocations with remotely sensed data on forage characteristics and surface water, we quantified the effect of body size and digestive system in determining movements of 30 populations of hindgut fermenters (equids) and ruminants across biomes. Selection for intermediate forage biomass was negatively related to body size, regardless of digestive system. Selection for proximity to surface water was stronger for equids relative to ruminants, regardless of body size. To be more generalisable, we suggest that the FMH explicitly incorporate contingencies in body size and digestive system, with small‐bodied ruminants selecting more strongly for potential energy intake, and hindgut fermenters selecting more strongly for surface water.
Publisher: Wiley
Date: 10-2020
DOI: 10.1002/UOG.22214
Location: Belgium
Location: United States of America
No related grants have been discovered for Buuveibaatar Bayarbaatar.