A multiscale three-dimensional (3D) virtual histology approach is presented, based on two configurations of propagation phase-contrast X-ray tomography, which have been implemented in close proximity at the GINIX endstation at the beamline P10/PETRA III (DESY, Hamburg, Germany). This enables the 3D reconstruction of characteristic morphological features of human pancreatic normal and tumor tissue, as obtained from cancer surgery, first in the form of a large-scale overview by parallel-beam illumination, followed by a zoom into a region-of-interest based on zoom tomography using a Kirkpatrick–Baez mirror with additional waveguide optics. To this end 1 mm punch biopsies of the tissue were taken. In the parallel tomography, a volumetric throughput on the order of 0.01 mm3 s−1 was achieved, while maintaining the ability to segment isolated cells. With a continuous rotation during the scan, a total acquisition time of less than 2 min was required for a full tomographic scan. Using the combination of both setups, islets of Langerhans, a three-dimensional cluster of cells in the endocrine part of the pancreas, could be located. Cells in such an islet were segmented and visualized in 3D. Further, morphological alterations of tumorous tissue of the pancreas were characterized. To this end, the anisotropy parameter Ω, based on intensity gradients, was used in order to quantify the presence of collagen fibers within the entire biopsy specimen. This proof-of-concept experiment of the multiscale approach on human pancreatic tissue paves the way for future 3D virtual pathology.

/pdf/3d-virtual-histology-of-human-pancreatic-tissue-by-2gojbtahhv.pdf

3D virtual histology of human pancreatic tissue by multiscale phase-contrast X-ray tomography.

The umbilical artery lumen closes rapidly at birth, preventing neonatal blood loss, whereas the umbilical vein remains patent longer. Here, analysis of umbilical cords from humans and other mammals identified differential arterial-venous proteoglycan dynamics as a determinant of these contrasting vascular responses. The umbilical artery, but not the vein, has an inner layer enriched in the hydrated proteoglycan aggrecan, external to which lie contraction-primed smooth muscle cells (SMC). At birth, SMC contraction drives inner layer buckling and centripetal displacement to occlude the arterial lumen, a mechanism revealed by biomechanical observations and confirmed by computational analyses. This vascular dimorphism arises from spatially regulated proteoglycan expression and breakdown. Mice lacking aggrecan or the metalloprotease ADAMTS1, which degrades proteoglycans, demonstrate their opposing roles in umbilical vascular dimorphism, including effects on SMC differentiation. Umbilical vessel dimorphism is conserved in mammals, suggesting that differential proteoglycan dynamics and inner layer buckling were positively selected during evolution.

Vascular dimorphism ensured by regulated proteoglycan dynamics favors rapid umbilical artery closure at birth.

The Pathobiology of Pulmonary Arterial Hypertension.

The Pathobiology of Pulmonary Arterial Hypertension

Diffuse, interstitielle Lungenerkrankungen (ILD) des Sauglings- und Kindesalters (chILD) zeigen ein vom Erwachsenenalter deutlich abweichendes Krankheitsspektrum. Die etablierten Klassifikationen trennen dabei zwischen fur das fruhe Kindesalter typischen ILD und ILD ohne spezifischen Bezug zum Kindesalter. Die Einordnung beruht dabei auf einer synoptischen Betrachtung der Befunde von Klinik, Bildgebung, Genetik und Pathologie. Eine Lungenbiopsie wird in der Regel eingesetzt, um eine spezifische chILD-Diagnose bei bislang unklarem Befund zu erheben oder eine rasch progrediente Lungensymptomatik bzw. einen prolongierten Symptomverlauf abzuklaren. Da auch Pathologen auserhalb von Referenzzentren mit padiatrischen Lungenbefunden konfrontiert werden, stellt diese Ubersicht relevante klinische und morphologische Befunde charakteristischer chILD vor.

/pdf/interstitial-lung-disease-in-infancy-and-early-childhood-4aggt1fl4x.pdf

Interstitial lung disease in infancy and early childhood

This study aimed to explore the value of synchrotron-based phase-contrast microcomputed tomography (micro-CT) in pulmonary vascular pathobiology. The microanatomy of the lung is complex with intricate branching patterns. Tissue sections are therefore difficult to interpret. Recruited intrapulmonary bronchopulmonary anastomoses (IBAs) have been described in several forms of pulmonary hypertension, including alveolar capillary dysplasia with misaligned pulmonary veins (ACD/MPV). Here, we examine paraffin-embedded tissue using this nondestructive method for high-resolution three-dimensional imaging. Blocks of healthy and ACD/MPV lung tissue were used. Pulmonary and bronchial arteries in the ACD/MPV block had been preinjected with dye. One section per block was stained, and areas of interest were marked to allow precise beam-alignment during image acquisition at the X02DA TOMCAT beamline (Swiss Light Source). A ×4 magnifying objective coupled to a 20-µm thick scintillating material and a sCMOS detector yielded the best trade-off between spatial resolution and field-of-view. A phase retrieval algorithm was applied and virtual tomographic slices and video clips of the imaged volumes were produced. Dye injections generated a distinct attenuation difference between vessels and surrounding tissue, facilitating segmentation and three-dimensional rendering. Histology and immunohistochemistry post-imaging offered complementary information. IBAs were confirmed in ACD/MPV, and the MPVs were positioned like bronchial veins/venules. We demonstrate the advantages of using synchrotron-based phase-contrast micro-CT for three-dimensional characterization of pulmonary microvascular anatomy in paraffin-embedded tissue. Vascular dye injections add additional value. We confirm intrapulmonary shunting in ACD/MPV and provide support for the hypothesis that MPVs are dilated bronchial veins/venules.

/pdf/synchrotron-based-phase-contrast-micro-ct-as-a-tool-for-38v0isxt4w.pdf

Synchrotron-based phase-contrast micro-CT as a tool for understanding pulmonary vascular pathobiology and the 3-D microanatomy of alveolar capillary dysplasia

In children with single ventricle physiology, increased pulmonary vascular resistance may impede surgical progression or result in failing single ventricle physiology. The use of pulmonary vasodilators has been suggested as a potential therapy. However, knowledge on indication, dosage, and effect is limited. A retrospective case notes review of all (n = 36) children with single ventricle physiology, treated with pulmonary vasodilators by the UK Pulmonary Hypertension Service for Children 2004–2017. Therapy was initiated in Stage 1 (n = 12), Glenn (n = 8), or TCPC (n = 16). Treatment indications were high mean pulmonary arterial pressure, cyanosis, reduced exercise tolerance, protein-losing enteropathy, ascites, or plastic bronchitis. Average dose of sildenafil was 2.0 mg/kg/day and bosentan was 3.3 mg/kg/day. 56% had combination therapy. Therapy was associated with a reduction of the mean pulmonary arterial pressure from 19 to 14 mmHg (n = 17, p < 0.01). Initial therapy with one or two vasodilators was associated with an increase in the mean saturation from 80 to 85%, (n = 16, p < 0.01). Adding a second vasodilator did not give significant additional effect. 5 of 12 patients progressed from Stage 1 to Glenn, Kawashima, or TCPC, and 2 of 8 from Glenn to TCPC during a mean follow-up time of 4.7 years (0–12.8). Bosentan was discontinued in 57% and sildenafil in 14% of treated patients and saturations remained stable. Pulmonary vasodilator therapy was well tolerated and associated with improvements in saturation and mean pulmonary arterial pressure in children with single ventricle physiology. It appears safe to discontinue when no clear benefit is observed.

/pdf/pulmonary-vasodilator-therapy-in-children-with-single-180jupx5j9.pdf

Pulmonary Vasodilator Therapy in Children with Single Ventricle Physiology: Effects on Saturation and Pulmonary Arterial Pressure.

In pulmonary arterial hypertension, plexiform lesions are associated with severe arterial obstruction and right ventricular failure. Exploring their structure and position is crucial for understand...

Distinct types of plexiform lesions identified by synchrotron-based phase-contrast micro-CT

The use of pulmonary vasodilator therapy in children born preterm is largely unknown. Our aim was to map prescription patterns in children with bronchopulmonary dysplasia in Sweden.This was a descriptive national registry-based study of children <7 years who had been prescribed a pulmonary vasodilator during 2007-2017, were born preterm and classified as having bronchopulmonary dysplasia. Information on prescriptions, patient characteristics and comorbidities were retrieved from the Swedish Prescribed Drug Register and linked to other national registers.The study included 74 children, 54 (73%) born at 22-27 weeks' gestation and 20 (27%) at 28-36 weeks. Single therapy was most common, n = 64 (86.5%), and sildenafil was prescribed most frequently, n = 69 (93%). Bosentan, iloprost, macitentan and/or treprostinil were used mainly for combination therapies, n = 10 (13.5%). Patent ductus arteriosus or atrial septal defect were present in 29 (39%) and 25 (34%) children, respectively, and 20 (69%) versus 3 (12%) underwent closure. Cardiac catheterisation was performed in 19 (26%) patients. Median duration of therapy was 4.6 (1.9-6.8, 95% CI) months. Mortality was 9%.Preterm children with bronchopulmonary dysplasia were prescribed pulmonary vasodilators, often without prior catheterisation. Sildenafil was most commonly used. Diagnostic tools, effects, and drug safety need further evaluation. 

http://umu.diva-portal.org/smash/get/diva2:1722518/FULLTEXT01

Ida Jeremiasen

Papers

Synchrotron-based phase-contrast micro-CT as a tool for understanding pulmonary vascular pathobiology and the 3-D microanatomy of alveolar capillary dysplasia

Pulmonary Vasodilator Therapy in Children with Single Ventricle Physiology: Effects on Saturation and Pulmonary Arterial Pressure.

Distinct types of plexiform lesions identified by synchrotron-based phase-contrast micro-CT

Outpatient prescription of pulmonary vasodilator therapy to preterm children with bronchopulmonary dysplasia

Pulmonary Vasodilator Therapy in Children Born Preterm with Bronchopulmonary Dysplasia (BPD): A Nationwide Study