UPI-Net: Semantic Contour Detection in Placental Ultrasound

Semantic contour detection is a challenging problem that is often met in medical imaging, of which placental image analysis is a particular example. In this paper, we investigate utero-placental interface (UPI) detection in 2D placental ultrasound images by formulating it as a semantic contour detection problem. As opposed to natural images, placental ultrasound images contain specific anatomical structures thus have unique geometry. We argue it would be beneficial for UPI detectors to incorporate global context modelling in order to reduce unwanted false positive UPI predictions. Our approach, namely UPI-Net, aims to capture long-range dependencies in placenta geometry through lightweight global context modelling and effective multi-scale feature aggregation. We perform a subject-level 10-fold nested cross-validation on a placental ultrasound database (4,871 images with labelled UPI from 49 scans). Experimental results demonstrate that, without introducing considerable computational overhead, UPI-Net yields the highest performance in terms of standard contour detection metrics, compared to other competitive benchmarks.Comment: 9 pages, 8 figures, accepted at Visual Recognition for Medical Images (VRMI), ICCV 201

Optimization of biomarkers for morphological analysis of healthy and preeclamptic term human placental tissue sections using advanced fluorescence microscopy methods

Preeclampsia (PE) is a pregnancy-related disorder affecting 5-8% of women worldwide (4% in Norway). It is believed that placental ischemia is the initial event in the development of PE and is characterized by placental insufficiency and clinical symptoms such as hypertension and proteinuria. In this project, we aimed to study suitable biomarkers for morphological analysis of human term placenta from normal pregnancies and women with PE using advanced fluorescence microscopes. To reach this objective, we optimized the labeling steps for advanced fluorescence optical microscopy imaging of formalin-fixed paraffin-embedded (FFPE) and cryo-preserved tissue sections of the human placenta. Furthermore, morphological and subcellular differences between healthy and preeclamptic placentas were investigated. For this, various fluorescence microscopy techniques were explored, including whole-slide scanner, high-resolution deconvolution microscopy (DV) and super-resolution structured illumination microscopy (SIM), along with diverse image processing tools and analysis of the microscopy images. In this thesis, diverse strategies were examined for the labeling of placental biomarkers including immunofluorescence staining of laeverin, cytokeratin-7 (CK-7) and placental alkaline phosphatase (PLAP), as well as direct labeling of F-actin, membranes and nuclei via phalloidin-Atto 647 N, CellMask Orange (CMO) and DAPI, respectively. The microscopy investigation revealed actin spots abundantly localized in subtypes of the chorionic villi in both healthy and PE placentas, such as terminal villi (p-value 0.55), mature intermediate villi (p-value 0.50), immature intermediate villi (p-value 0.54) and stem villi (p-value 0.47), thus no observable differences. However, we found significant differences (p-value 0.015) of syncytial knots in PE compared to healthy tissue. A disorganized brushborder at the apical surface seems to be observed in the PE chorionic villi. Moreover, we found PLAP expression in the syncytial microvesicles in healthy placentas. The immunofluorescence study using laeverin and CK-7 antibodies seem to show co-localization in the syncytial plasma membrane in healthy placentas, though the labeled PE tissues showed laeverin expression in the syncytial plasma membrane and cytoplasm, including overexpression of laeverin in the fetal capillaries. In conclusion, the biomarkers explored in this study may have the potential to play an important role in understanding and predict PE in the future

Quantification of Placental Dysfunction in Pregnancy Complications

Background The pathogenetic mechanisms behind placental dysfunction-related complications like preeclampsia and intrauterine growth restriction have remained perplexing till now, in part because of lack of well-defined structural and functional molecular characterisation. There is growing evidence that links trophoblast debris and the existence of syncytial nuclear aggregates (SNA) to the pathogenesis of gestational diseases. Characterisation and quantification of structural and functional parameters of placental dysfunction may give researchers a clearer picture of the mechanisms underlying the development of high risk pregnancy. Methods Placental samples were obtained from normal term pregnancies, preterm controls, as well as from pregnancies complicated by preeclampsia (PET), intrauterine growth restriction (IUGR) and PET-IUGR. Formalin-fixed, paraffin-embedded sections were visualised with H&E, stained using immunohistochemistry (IHC) and digitally scanned. Using stereological methodology, volumes of placental SNAs, trophoblasts, villi and capillaries were measured. Three dimensional (3D) volume reconstructions of terminal placental villi with SNAs and fibrinoid degenerations were created. IHC-labelled slides were analysed by image analysis algorithms. Differential expression of placental genes and miRNAs, hypothesised to regulate cell death in placental dysfunction, were quantified using RT-qPCR. BeWo cell lines were carried out for in vitro validation of the effects miRNAs regulating programmed cell death (PCD) using flow cytometry and western blotting. Results Specific morphometric patterns of villous, trophoblasts, SNA and capillary volumes were demonstrated with characteristic higher SNAs and lower capillary volumes in PET placentae with reciprocal patterns in IUGR placentae showing a negative correlation pattern between nuclear aggregates and capillary volumes. Image analysis of immune-labelled slides showed a higher autophagy marker expression in PET and a positive correlation to SNAs as well as a balanced reciprocal expression patterns with apoptosis. Moreover, miR-204 transfected BeWo cells showed a similar balanced reciprocal regulation of autophagy and apoptosis expressions. Conclusion We have demonstrated that applying stereology-based and image analysis on digitised placental sections can be useful in quantifying and dissecting structural and functional patterns in normal and abnormal placental function. 3D reconstruction model are a novel approach towards placental characterisation in normal and complicated pregnancies. The study also showed that miR-204 plays a vital role in the regulation of placental autophagy and apoptosis, critical in the pathophysiology of placental dysfunction

Quantification of Placental Dysfunction in Pregnancy Complications

Background The pathogenetic mechanisms behind placental dysfunction-related complications like preeclampsia and intrauterine growth restriction have remained perplexing till now, in part because of lack of well-defined structural and functional molecular characterisation. There is growing evidence that links trophoblast debris and the existence of syncytial nuclear aggregates (SNA) to the pathogenesis of gestational diseases. Characterisation and quantification of structural and functional parameters of placental dysfunction may give researchers a clearer picture of the mechanisms underlying the development of high risk pregnancy. Methods Placental samples were obtained from normal term pregnancies, preterm controls, as well as from pregnancies complicated by preeclampsia (PET), intrauterine growth restriction (IUGR) and PET-IUGR. Formalin-fixed, paraffin-embedded sections were visualised with H&E, stained using immunohistochemistry (IHC) and digitally scanned. Using stereological methodology, volumes of placental SNAs, trophoblasts, villi and capillaries were measured. Three dimensional (3D) volume reconstructions of terminal placental villi with SNAs and fibrinoid degenerations were created. IHC-labelled slides were analysed by image analysis algorithms. Differential expression of placental genes and miRNAs, hypothesised to regulate cell death in placental dysfunction, were quantified using RT-qPCR. BeWo cell lines were carried out for in vitro validation of the effects miRNAs regulating programmed cell death (PCD) using flow cytometry and western blotting. Results Specific morphometric patterns of villous, trophoblasts, SNA and capillary volumes were demonstrated with characteristic higher SNAs and lower capillary volumes in PET placentae with reciprocal patterns in IUGR placentae showing a negative correlation pattern between nuclear aggregates and capillary volumes. Image analysis of immune-labelled slides showed a higher autophagy marker expression in PET and a positive correlation to SNAs as well as a balanced reciprocal expression patterns with apoptosis. Moreover, miR-204 transfected BeWo cells showed a similar balanced reciprocal regulation of autophagy and apoptosis expressions. Conclusion We have demonstrated that applying stereology-based and image analysis on digitised placental sections can be useful in quantifying and dissecting structural and functional patterns in normal and abnormal placental function. 3D reconstruction model are a novel approach towards placental characterisation in normal and complicated pregnancies. The study also showed that miR-204 plays a vital role in the regulation of placental autophagy and apoptosis, critical in the pathophysiology of placental dysfunction

Cell Culture

Cell culture is cell cloning technology that simulates in vivo environment conditions such as asepsis, appropriate temperature, and pH as well as certain nutritional conditions to enable cells to survive, grow, reproduce, and maintain their structure and function. Cell culture can be used to grow human, animal, plant, and microbial cells. Each type of cell culture has its own characteristics and essential conditions. This book focuses on the advanced technology and applications of cell culture in the research and practice of medical and life sciences. Chapters address such topics as primary cancer cell cultures, 2D and 3D cell cultures, stem cells, nanotechnology, and more