AIM To construct a non-normalized cDNA library from Agkistrodon acutus venom gland as an imtial step to develop new and more effective venom by genetic engineering technique for screening and expressing target genes. METHODS The total RNA was extracted from fresh venom gland using Trizol. mRNA was reversely transcripted to cDNA using superscriptⅡ reverse transcriptase. Second-strand synthesis was performed using DNA polymeraseⅠ. After adding EcoRⅠ adaptor, phosphorylating the end and digesting with XhoⅠ, the cDNA was collected in five fractions (<0.25 kb, 0.25-0.5 kb, 0.5-1 kb, 1-2 kb and >2 kb) using the QIAquick Gel Extraction kit and ligated to pBluescriptⅡ vectors. The five libraries obtained were plated by infecting E.coli DH10B, constructing a cDNA library of Agkistrodon acutus venom gland. Sequencing clones at random, 8696 high quality 5′ end expressed sequenced tags (ESTs) were obtained and analyzed. The initial sequences were assembled into 2855 clusters. Among which, one of the clusters (Agkihagin) consisting of 74 ESTs was identified as a novel metalloprtoteinase based on RT-PCR and sequence analysis. RESULTSThe titers of library were 2.048×106. The novel metalloproteinase belonged to PⅢ type metalloproteinase. Its open reading frame was composed of 1827 nucleotides and coded a pre-zymogen of 608 amino acid with zinc-binding domain for metalloproteinase and Asp-Glu-Cys-Asp(DECD) domain for disintegrin. CONCLUSION The capacity of cDNA library of venom gland is above the general level of cDNA library. It would be a helpful platform to construct a catalog for transcripts in the venom gland of the Agkistrodon acutus. The sequence analysis indicates that the deduced amino acid sequence of the identified gene for metalloproteinase share the highest 87% identity with the metalloproteinase genes of other snakes in the GenBank. It lays a good foundation for the study of structure-function relationships of snake venom metalloproteinases.

Objective:To evaluate the safety and effectiveness of the accurate puncture during sacral neuromodulation (SNM) guided with 3D printing navigation template based on reconstruction techniques using fusing sacral CT and MRI images.Methods:Totally 42 patients operated with SNM were selected in Renji Hospital, School of Medicine, Shanghai Jiaotong University from July 2016 to August 2017. The patients were randomly divided into control group ( n=22) and experimental group ( n=20) using random number table. The conventional cross-positioning technique under X-ray was used for puncture during SNM in the control group. While in the experimental group, the sacral CT and MRI images were fused for reconstruction and design of the navigation template, printed by 3D technique for the puncture in SNM. The times of punctures, the average time for puncture operation, the time of intraoperative testing of the stimulator device, the minimum onset voltage of the stimulator, the X-ray radiation dose, postoperative curative effect (rate of secondary transformation) and the incidence rate of complications were compared between the two methods using independent-simple t test or χ 2 test. Results:Compared to control group, fewer times of punctures, shorter time needed for puncture operation, shorter time of intraoperative testing of the stimulator, smaller radiation dose and minimum effective voltage were found in the experimental group ( P<0.05). There were 15 and 16 patients who completed the secondary transformation in the control group and experimental group, and there was no significant difference between the two groups (χ2=0.757, P=0.384). There were 3 cases of complications in the control group, including 2 cases of infection and 1 case of bleeding, while no complications in the experimental group. Conclusions:CT and MRI images fusion reconstruction-guided 3D printing navigation template can help perform accurate and safe punctures in SNM. Compared to conventional puncture positioned under X-ray, it can effectively improve the puncture efficiency, and reduce the radiation dose in the operation.