Image Processing and Analysis of Mucosal Calretinin Staining to Define the Transition Zone in Hirschsprung Disease: A Pilot Study.

PURPOSE: Quantification of calretinin-stained mucosal nerve fibers by image processing and analysis (IPA) may objectively define the transition zone (TZ) of Hirschsprung disease (HD). We tested the utility of IPA as an adjunctive tool in HD. MATERIALS AND METHODS: Calretinin immunostain was performed on 15 HD pull-through specimens, and multiple images were captured from the proximal aganglionic zone, TZ, and probable normal zone (NZ). Pixel count (PC), defined as the percentage of brown-stained pixels in the mucosa, was quantified and plotted against distance from the rectal distal end. To validate the method, PCs from 45 images were compared with three-tiered visual scoring by five pathologists. Results were correlated against pertinent variables, which were retrieved from the clinical record. RESULTS: The PC gradually increased in the TZ toward the proximal resection margin in 10/13 (77%) cases. The PC variation in the probable NZ and around the circumference was substantial by the coefficient of variation. The mean PC of images with a visual score of 1 was less than scores of 2 and 3 by all five (100%) pathologists (p < 0.01). One patient had possible TZ pull-through that was clinically confirmed. CONCLUSION: While the mucosal calretinin staining gradually increases in the TZ, for now, the boundaries of the TZ cannot be accurately defined by mucosal biopsies given the substantial variation of staining around the circumference at the same distance and in the NZ. However, the IPA technique does provide a continuous variable and warrants further utility in HD studies.

Intracytoplasmic granulocytic morulae counts on confirmed cases of ehrlichiosis/anaplasmosis in the Northeast.

OBJECTIVES: To characterize the number of granulocytes needed to count on peripheral smear to identify diagnostic anaplasmosis morulae. METHODS: Retrospective case study where the peripheral smears of 14 confirmed cases of anaplasmosis were examined. The granulocytes were counted up to 100 and 200 until a morula was identified. The mean counts of three pathologists were calculated to determine the minimum number of granulocytes needed to count for identifying diagnostic morulae. RESULTS: Morulae were identified before a count of 100 granulocytes in 11 (78.6%) cases and between 100 and 200 granulocytes in 3 (21.4%) cases. All 14 (100%) cases had morulae identified before counting 200 granulocytes. CONCLUSIONS: Peripheral smears are a useful, cost-effective, and time-effective tool for diagnosing anaplasmosis. In positive cases, diagnostic morulae can be identified with a count of 200 granulocytes.

Regulation of the association of alpha 6 beta 4 with vimentin intermediate filaments in endothelial cells.

The adhesion of microvascular endothelial cells to their underlying basement membrane is important for the maintenance of vascular integrity. Most integrins function in endothelial cell adhesion by forming a transmembrane link between their basement membrane ligand and the actin microfilament cytoskeleton. The alpha 6 beta 4 laminin-binding integrin, however, associates with vimentin intermediate filaments (IFs) in microvascular endothelial cells and therefore is likely to uniquely contribute to the barrier function of the endothelium. In this study, we examined the regulation of alpha 6 beta 4-vimentin IF association. We first tested the requirement for alpha 6 beta 4-laminin interactions and actin microfilament assembly. We found that alpha 6 beta 4 associated with vimentin IFs when cells were adherent to either laminin 5 or fibronectin, indicating that this association can occur independent of alpha 6 beta 4-ligand interactions. Additionally, we found that alpha 6 beta 4 was associated with vimentin IFs prior to cell spreading, indicating that changes in the microfilament cytoskeleton associated with changes in cell shape are also not required. Thus, although the association of alpha 6 beta 4 with vimentin IFs may strengthen cell adhesion by providing endothelial cells with an additional transmembrane linkage between the basement membrane and the cytoskeleton, this association is not itself regulated by alpha 6 beta 4-mediated adhesion. Finally, we tested the role of plectin in the association of alpha 6 beta 4 with vimentin IFs. Plectin is known to bind in vitro to both IFs and the beta 4 cytoplasmic domain (beta 4 tail), suggesting that it may be important for this linkage. Therefore, we generated deletion mutants of the beta 4 tail and compared the ability of alpha 6 beta 4 containing these deletions to associate with vimentin IFs. We targeted the two regions of the beta 4 tail known to bind to plectin IN VITRO: the N-terminal and C-terminal plectin binding sites. We found that deletion of the N-terminal binding site inhibited the association of alpha 6 beta 4 with vimentin IFs. Thus, plectin-beta 4 tail interactions may play an important role in connecting alpha 6 beta 4 with vimentin IFs and may prove to be important targets in the regulation of this association in endothelial cells.