Biomedical subjects
Publications and source records attributed to Jeffrey L Clendenon.
Advances in microscopy now enable researchers to easily acquire multi-channel three-dimensional (3D) images and 3D time series (4D). However, processing, analyzing, and displaying this data can often be difficult and time- consuming. We discuss some of the software tools and techniques that are available to accomplish these tasks.
Cystic kidney disease has been linked to mutations in the Invs gene in mice with inversion of embryonic turning (inv/inv) and the INVS (NPHP2) gene in infants with nephronophthisis type 2 (NPHP2). The inv mouse model features multiorgan defects including renal cysts, altered left-right laterality, and hepatobiliary duct malformations transmitted in an autosomal recessive manner. Affected mice usually die of renal and liver failure by postnatal day 7. Although cardiopulmonary and liver anomalies have been carefully detailed, renal cysts have yet to be fully characterized in inv/inv. By use of three-dimensional visualization by two-photon microscopy, this study provides the first comprehensive analysis of in situ cyst formation and progression in inv/inv kidneys. At embryonic day 15, there is dilatation of Bowman's capsule followed temporally by corticomedullary cysts involving collecting ducts, proximal tubules, and thick ascending limbs. Collecting ducts of newborn inv/inv mice are uniformly and diffusely cystic from medulla to cortex, with normal diameters found only at their most proximal tips. Proximal tubules form fusiform cysts that alternate with segments of normal or narrowed caliber along torturous convolutions. Because defective cilia have been linked to situs inversus and cystogenesis, we examined inv/inv cilia by scanning and transmission electron microscopy. The former detected monocilia of expected length in cystic collecting ducts and proximal tubules; the latter demonstrated the usual 9 + 2 pattern in respiratory cilia. The inv mutant mouse has renal cysts resembling infantile NPHP2 and will provide broader insight into the role cilia play in renal cystogenesis.
BACKGROUND: Various structural components of human skin biopsy specimens are difficult to visualize using conventional histologic approaches. METHODS: We used two-photon microscopy and advanced imaging software to render three-dimensional (3D) images of in situ nerves, blood vessels, and hair follicles labeled with various fluorescent markers. Archived frozen human skin biopsy specimens were cryosectioned up to 150 micro m in thickness and fluorescently stained with rhodamine- or fluorescein-labeled antibodies or lectins. Optical sections were collected by two-photon microscopy and the resulting data sets were analyzed in three dimensions using Voxx software. RESULTS: Reconstructed image volumes demonstrated the complex 3D morphology of nerves, blood vessels and adnexal structures in normal mucocutaneous tissue. CONCLUSION: Two-photon microscopy and Voxx rendering software allow for detailed 3D visualization of structures within human mucocutaneous biopsy specimens, as they appear in situ, and facilitate objective interpretation of variations in their morphology. These techniques may be used to investigate disorders involving cutaneous structures that are difficult to visualize by means of traditional microscopy.
Confocal and two-photon fluorescence microscopy have advanced the exploration of complex, three-dimensional biological structures at submicron resolution. We have developed a voxel-based three-dimensional (3-D) imaging program (Voxx) capable of near real-time rendering that runs on inexpensive personal computers. This low-cost interactive 3-D imaging system provides a powerful tool for analyzing complex structures in cells and tissues and encourages a more thorough exploration of complex biological image data.