[SEM observation on leaf epidermis of different Ephedra species].

OBJECTIVE: Characters of stem epidermis, leaf epidermis and stoma could be used as important microcosmic morphological characteristic when inheritance trend is studied in Ephedra breeding and identification. METHOD: The stomatic density, stoma major axis and mimor axis, stomatic morphylogy, characters of leaf and stem epidermis of 6 Ephedra plants' stems were examined by SEM. RESULT: The stomatic density and characteristic of leaf epidermis and stem epidermis in six Ephedra species was differenc, there were no obvious morphological differences in stoma shape and size. The guard cells were covered with heavy cuticle and sunken stomata, which were the typical characteristics of xerophytes. The stomas of leaf lower epidermis were oblong or hexagon, but the stomas of steam epidermis were narrowed-oblong or dumbbell-shape, they all belonged to anomalous type. CONCLUSION: The stoma type and characters of Ephedra plants is stable and conservative, there was no obvious morphological differences in stoma shape and size between species, so it is difficult to distinguish different species by the variance of stomas, but that can be applyed to distinguish Ephedra from others at plant taxonomy.

[Antibody detection in sera of patients with Schistosomiasis japonica by dot immunogold filtration assay].

Serum antibody of schistosomiasis patients was detected by dot immunogold filtration method (DIGFA) in laboratory and field, and F-ELISA was used as control. The results showed that there was no significant difference between these two assays in sensitivity and specificity (P > 0.05), with a high coincidence. DIGFA is easy to operate and may deserve a wide application in the diagnosis of schistosomiasis.

[Screening and identification of egg mimotope of Schistosoma japonicum].

OBJECTIVE: To explore egg mimotope of Schistosoma japonicum that can be used in the development of diagnostic reagents for schistosomiasis. METHODS: By performing three rounds of biopanning in the affinity selection before picking out single clones for identification, target specific phages were effectively enriched from a random 15-peptides phage library with an immobilized mAb 6B12 which is specific to egg antigen of S. japonicum as a bait. By using ELISA, competitive ELISA with natural egg antigen as competitor, and Western blotting, 13 phage clones with high affinity and specificity to 6B12 were obtained and amplified from 400 single clones. RESULTS: DNA sequencing revealed that all the 13 selected single clones were identical in displaying gene sequence. Serum samples were tested by ELISA for the presence of IgG antibodies to the phages with mimic epitope, and showed that there was a significant difference between healthy volunteers and schistosomiasis patients. CONCLUSION: It is possible that the phage display peptide antigen, egg mimotope of S. japonicum may be a replacement of natural egg antigen for the diagnosis of schistosomiasis.