Neural electrophysiological effect of crude venom of conus textile from the south China Sea.

In the present study, we characterized effects of the crude venom from Conus textile, a marine molluscivorous snail collected from the South China Sea, on neural electrophysiological activity in insect, molluscan and mammalian species. Our results demonstrate that the venom reversibly blocks the cholinergic synaptic transmission of cockroach Periplaneta americana central nervous system, partially blocks Na(+) currents in rat hippocampal CA(1) pyramidal neurons, and enhances the excitability and spontaneous activity of the giant neurons of garden snail Achatina fulica.

An eligible biological allograft patch in tension-free herniorrhaphy of swine.

Current patches made from macromolecular compounds or composix for tension-free herniorrhaphy are still unsatisfactory in biocompatibility. The ideal patch should be a biological patch with good biocompatibility. Herein allograft patches modified by tissue engineering were used in tension-free herniorrhaphy of swines. Tough membrane tissues from swine were modified with patented tissue engineering techniques to develop allograft patches for tension-free herniorrhaphy. Histological, and physical tests of the allograft patch were performed subsequently, which revealed that the allograft patch was sufficient and satisfactory for tension-free herniorrhaphy. The allograft patches were next used in tension-free herniorrhaphy of abdominal external hernia models of swines and compared to polypropylene patches. Serous CD4+, CD8+ T cells, interleukin-1ß (IL-1ß), and tumor necrosis factor α (TNF-α) were determined preoperatively and postoperatively. Local pathological changes were recorded postoperatively in swines. In vivo application of the allograft patches revealed that there were no significant serous cellular immune responses in swines, and inflammation induced by allograft patches was significantly lower compared to polypropylene patches, the allograft patches gradually degenerated and new collagen fibers appeared. Abdominal external hernias were cured with allograft patches and without relapse. The modified allograft patch with satisfactory biocompatibility was eligible and sufficient in tension-free herniorrhaphy of swine. Clinical trials should be performed for further evaluation of the allograft patch.

Studies on conotoxins of Conus betulinus.

The biological activity and toxicity of crude venom from Conus betulinus, which was collected from the South China Sea, were studied. The venom shows Ach receptor activity, K+ current effect, and low toxicity. Four peptide components, named BeTXIa, BeTXIb, BeTXIIa, and BeTXIIb, were purified by gel-filtration with Sephadex followed by HPLC, and finally sequenced on an ABI model 491 sequencer. The low-molecular-weight peptides BeTXIa and b have 14 and 15 amino acid residues, respectively, while BeTXIIa and b have 27 and 30 amino acid residues, respectively. The results indicate that BeTXs from the venom of C. betulinus are a set of small peptides with a high cysteine content like known conotoxins. However, it is meaningful to find that these sequences have specific chemical characteristics in their cysteine framework which differ greatly from known cysteine frameworks in conotoxin structures.