Study on determination of 2-thioxothiazolidine-4-carboxylic Acid in urine by high performance liquid chromatography / 中华劳动卫生职业病杂志

Objective: To establish a high performance liquid chromatography method for the determination of 2-thioxothiazolidine-4-carboxylic acid (TTCA) in urine. Methods: After acidification with hydrochloric acid, TTCA in urine was first extracted by ethyl acetate with excessive sodium chloride, then gradient separated by a symmetry C18 column and then detected by a diode array detector. The quantification was based on a working curve of external standard method. Results: The linear relationship of TTCA in urine was good in the range of 0.03-10.00 mg/L, and the correlation coefficient was 0.9999. The detection limit and minimum quantitative concentration of TTCA in urine were 0.008 mg/L and 0.027 mg/L. The intra-assay precision of the method was 0.9%-1.4%, the inter-assay precision was 1.3%-3.5%, and the average recovery was 85.0%-92.7% while the concentrations of TTCA in urine was 0.8, 2.0 and 8.0 mg/L, respectively (n=6) . Conclusion: The gradient elution high performance liquid chromatography method has simple operation and high sensitivity, and it is suitable for the determination of TTCA on a low level in urine for occupational workers exposure to carbon disulfide.

Cloning and expression of three PAL genes in Astragalus membranaceus / 中草药

Objective To disclose the molecular mechanism of calycosin-7-O-β-D-glucoside (CG) accumulation in Astragalus membranaceus, we cloned PAL genes and analyzed the expression patterns of them and changes of CG contents in different tissues of A. membranaceus. Methods PAL genes were cloned with the methods of homology cloning and RACE technique using the total RNA as template and the analysis of bioinformatics on the cloned genes was carried out, gene expressions in root, stem, and leaf were determined with real-time PCR method, and CG content in root, stem, and leaf were analyzed by HPLC methods. Results Three PAL genes were cloned from A. membranaceus. The genbank accession number was KY086279 (AmPAL1), KY086280 (AmPAL2), and KY086281 (AmPAL3), respectively; The full-length cDNA of them was 2 508 bp, 2 401 bp, and 2 498 bp, respectively; And they all consisted of 2 157 bp open reading frame encoding 718 amino acids. Deduced AmPAL proteins had typical active sequences of PAL proteins, they were homology with other PAL proteins, and they shared the highest identities with PAL proteins of leguminous plants. Phylogenetic tree analysis showed AmPAL1 belonged to the different sub-class with the sub-class of AmPAL2 and AmPAL3. Real-time PCR analysis indicated that expression levels of AmPALs were different from each other, the expression level of AmPAL1 was the highest, the expression level of AmPAL2 was the next, and that of AmPAL3 was lowest in all detected tissues, and only the expression levels of AmPAL2 was similar to the changes of CG contents in different tissues (root > stem > leaf). Conclusion The cloned AmPAL1, AmPAL2, and AmPAL3 from A. membranaceus were typical genes of PAL, each might have different function in developing of different tissues, and AmPAL2 might involve in CG accumulation in different tissues.

Construction of a GFP-fused mouse PACRG baculovirus recombinant vector and expression of the fusion protein in Sf9 inset cells / 中华男科学杂志

<p><b>Objective</b>To construct a GFP-fused mouse Parkin co-regulated gene (PACRG) baculovirus recombinant PACRG/GFP-pFastBac1 vector and express the fusion protein in Sf9 insect cells.</p><p><b>METHODS</b>Full-length mouse PACRG cDNA was amplified by PCR and cloned in frame to the vector pFastBac1 with eGFP (rpFBac-PACRG-GFP recombinant vector). The plasmid was transformed into DH10Bac cells to obtain the recombinant bacmid plasmid, the bacmid was transfected into Sf9 insect cells, and the expressed PACRG/GFP fusion protein was analyzed by Western blot and fluorescence microscopy.</p><p><b>RESULTS</b>The construction of the PACRG/GFP-pFastBac1 baculovirus plasmid was confirmed by sequencing and restriction enzyme digestion. Western blot showed the expression of the fusion protein carrying a green fluorescence in the Sf9 insect cells.</p><p><b>CONCLUSIONS</b>Conclusion: A PACRG/GFP-pFastBac1 recombinant baculovirus vector was successfully constructed and the fusion protein was highly expressed in the Sf9 insect cells. Our findings have provided a basis for further studies on the structure of the PACRG protein and regulation of spermatogenesis.</p>

Interaction between SPAG6 and TAC1 proteins / 中华男科学杂志

<p><b>Objective</b>To construct eukaryotic expression plasmids of the Tac1 gene and explore the interaction between TAC1 and sperm-associated antigen 6 (SPAG6).</p><p><b>METHODS</b>RNA was extracted from the heart, liver, spleen, lung, kidney, brain, muscle, and testis of 10 Kunming male mice and, after reverse transcription into cDNA, the expression of Tac1 in the above tissues was observed by RT-PCR. Tac1/pEGFP-N2 and Tac1/pGADT7 recombinant plasmids were constructed and Tac1/pEGFP-N2 was transfected into CHO and COS-1 cells, followed by localization and detection of the protein expression of TAC1 by immunofluorescence staining and Western blot. The interaction between TAC1 and SPAG6 was determined by yeast two-hybrid experiment and Western blot.</p><p><b>RESULTS</b>Tac1 was expressed mainly in the testis, brain and heart. The results of restriction enzyme digestion and sequencing indicated successful construction of the recombinant plasmids, with the restriction fragment length of 390 bp. TAC1 was localized in the whole body of the CHO cells when transfected alone, but expressed in the microtubule of the cells when cotransfected with SPAG6, with the molecular weight of 40 000. Yeast two-hybrid experiment showed the colonies of TAC1 and SPAG6 on the culture plate without Leu, Trp and His, both contained in the yeast fusion protein.</p><p><b>CONCLUSIONS</b>The Tac1 recombinant plasmid was constructed successfully and the interaction between TAC1 and SPAG6 was confirmed with the plasmid.</p>