Objective To explore the histochemical staining for distinguishing and local izing nerve fibers and fascicles at histological level in three-dimensional reconstruction of peri pheral nerves. Methods The right median nerve was harvested from one fresh cadaver and embedded in OCT compound. The sample was serially horizontally sl iced with 6 μm thickness. All sections were stained with Karnovsky-Roots method (group A, n=30) firstly and then stained with toluidine blue (group B, =28) and Ponceau 2R (group C, n=21) in proper sequence. The results of each step were taken photos (× 100). After successfully stitching, the two-dimensional panorama images were compared, including texture feature, the number and aver gray level of area showing acetylchol inesterase (AchE) activity, and result of auto microscopic medical image segmentation. Results In groups A, B, and C, the number of AchE-positive area was (21.63 ± 4.06)× 102, (20.64 ± 3.51)× 102, and (20.54 ± 5.71)× 102, respectively, showing no significant difference among 3 groups (F=0.64, P=0.54); the mean gray level was (1.41 ± 0.06)× 102, (1.10 ± 0.05)× 102, and (1.14 ± 0.07)× 102, respectively, showing significant differences between group A and groups B and C (P lt; 0.001). In the image of group A, only AchE-positive area was stained; in the image of group B, myelin sheath was obscure; and in the image of group C, axons and myelin sheath could be indentified, the character of nerve fibers could be distinguished clearly and accurately, and the image segmentation of fascicles could be achieved easier than other 2 images. Conclusion The image of Karnovsky-Roots-toluidine blue-Ponceau 2R staining has no effect on the AchE-positive area in the image of Karnovsky-Roots staining and shows better texture feature. This improved histochemical process may provide ideal image for the three-dimensional reconstruction of peri pheral nerves.
Objective To investigate how to establish stable mice cervical heart transplantation model. Methods Totally, 40 male C57 mice with the age of 6-8 weeks and weight of 19-24 g were randomly divided into recipients and donors (n=20 in each group). Mice cervical heart transplantation model was established by connecting the ascending aorta of donors to the right cervical common artery of recipients through end to side anastmosis and the pulmonary artery of donors to the right external jugular vein of recipients through end to end anastmosis. Results More than 95% recipients survived after surgery. Cold ischemia time was 15±5 min, warm ischemia time 23±6 min, and the whole operation took about 55±15 min. The recipients survived more than 30 d with functional heart grafts. Histologically, there was no difference between the heart graft one month after the transplantion and the normal heart. Conclusion Cervical heart transplantation of mice model is reliable and feasible, which is easy to monitor the survival condition of heart graft by visual examination and palpation, which will benefit the basic research in transplantation field.