After this procedure, the distal colon is then usually located at the centre, whilst the proximal colon at the outside of the roll. Traditionally, this involves turning the murine colon into a Swiss roll, a technique whereby the entire intestine (approximately 6–7 cm in length) is cut longitudinally, laid flat, then rolled into a spiral before chemical fixation and paraffin embedding 13. In the specific case where the morphology of crypt budding is of interest, the challenging shapes of the crypts make it difficult to (routinely) prepare such sections along individual crypts, resulting in colonic cross sections with crypts that are only partially visible (see Fig.
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Conversely, when it is necessary to capture the entire crypt on a microscope slide, for instance to study crypt budding, the physical sections of the colon need to be taken along individual crypts, perpendicular to the colonic mucosa and across different tissue layers 11, 12. Paraffin sections of the physically flattened and embedded colons may then be taken parallel to the colonic mucosa 10 to study the shapes of the crypt cross sections (see Fig. Small tissue samples of the colon are typically isolated, cut open longitudinally and flattened before being embedded in wax blocks to examine the morphological changes of colonic crypts 6– 9. Standard practice in CRC research involves the use of animal models, where animals are sacraficed and their colon excised. This leads to asymmetrical branching or budding, where the splitting process does not complete, and the daughter crypt remains attached to its parent. During the early developmental stages of colorectal cancer (CRC), the fission process is disturbed 2, 4, 5. The process begins with a single parent crypt that splits into two identical daughters 2, 3.
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1), multiply through a symmetric branching process called ‘crypt fission’. In health, crypts or colonic crypts, which are tubular glands in the colon 1 (see Fig. Our 3D cyclorama method can provide novel insights into a wide spectrum of applications where digital unrolling or flattening is necessary, including long bones, teeth roots and ancient scrolls. This enables the study of features extending over several layers of the tube’s depth, demonstrated here by two case studies: (i) microvilli in the human placenta and (ii) 3D-printed adhesive films for drug delivery.
DIGITAL THICKNESS GRID MAPPING AIRCRAFT STRUCTURE SERIES
It employs principles from electrostatics to reform the tube into a series of onion-like surfaces, which are mapped onto planar panoramic views. Here, we present, verify and validate our ‘3D cyclorama’ method that digitally unrolls deformed tubes of non-uniform thickness. To study crypt budding in situ and in three dimensions (3D), we employ X-ray micro-computed tomography to image intact colons, and a new method we developed (3D cyclorama) to digitally unroll them. The challenging shapes of the budding crypts make it difficult to prepare paraffin sections for conventional histology, resulting in colonic cross sections with crypts that are only partially visible. During the early stages of colorectal cancer, the normal fission process is disturbed, leading to asymmetrical branching or budding. Colonic crypts are tubular glands that multiply through a symmetric branching process called crypt fission.