Publications by authors named "U Ahlgren"

We previously demonstrated that the lungs of deceased COVID-19 patients were filled with a clear hydrogel consisting of hyaluronan (HA). In this translational study, we investigated the role of HA at all stages of COVID-19 disease to map the consequences of elevated HA on morbidity and identify the mechanism of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-induced HA production. A reduced alveolar surface area was observed in the lungs of deceased COVID-19 patients compared to healthy controls, as visualized by a 3D rendering of lung morphology using light-sheet fluorescence microscopy.

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Pancreatic islets of Langerhans play a pivotal role in regulating blood glucose homeostasis, but critical information regarding their mass, distribution and composition is lacking within a whole organ context. Here, we apply a 3D imaging pipeline to generate a complete account of the insulin-producing islets throughout the human pancreas at a microscopic resolution and within a maintained spatial 3D context. These data show that human islets are far more heterogenous than previously accounted for with regards to their size distribution and cellular make up.

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Article Synopsis
  • Optical Projection Tomography (OPT) and light sheet fluorescence microscopy (LSFM) are advanced imaging techniques used for creating detailed 3D images of mouse brains, but tissue autofluorescence limits the anatomical detail.
  • T1-weighted MR images from 19 cleared brains were used to create an MR template, which was then fused with OPT and LSFM images for better visualization and identification of brain structures and infections.
  • The study resulted in two optimized templates for BABB and DBE cleared brains, facilitating anatomical mapping of fluorescent signals on MR images and enhancing neuroscience research applications.
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Viral tropism within the brain and the role(s) of vertebrate immune response to neurotropic flaviviruses infection is largely understudied. We combine multimodal imaging (cm-nm scale) with single nuclei RNA-sequencing to study Langat virus in wildtype and interferon alpha/beta receptor knockout (Ifnar) mice to visualize viral pathogenesis and define molecular mechanisms. Whole brain viral infection is imaged by Optical Projection Tomography coregistered to ex vivo MRI.

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The rodent pancreas is the prevalent model system for preclinical diabetes research. However, due to the compound endocrine-exocrine organization of the gland, with the endocrine islets of Langerhans scattered by the thousands throughout the much greater exocrine parenchyma, stereological assessments of endocrine cell mass, commonly insulin-producing ß-cells, are exceedingly challenging. In recent years, optical mesoscopic imaging techniques such as optical projection tomography (OPT) and light sheet fluorescence microscopy (LSFM) have seen dramatic developments, enabling 3D visualization of fluorescently labeled cells in mm- to cm-sized tissues with μm resolution.

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