Analysis of water-soluble nutrients in Lycium barbarum leaves and differences between different producing areas / 中国中药杂志

This study is to clarify the composition and content differences of water-soluble nutrients in Lycium barbarum leaves(LBLs) from different areas. The total polysaccharides, free monosaccharides and oligosaccharides, nucleosides and amino acids in 35 batches of LBLs were analyzed with use of spectrophotometry, HPLC-ELSD and UPLC-MS/MS. The results showed that LBLs contained abundant polysaccharides, fructose, glucose, sucrose and maltose, with an average contents of 39.07, 12.69, 8.99, 17.44, 8.32 mg·g~(-1), respectively. Besides, eight nucleosides and twelve amino acids were detected in LBLs, and their average total contents were 54.95, 336.9 μg·g~(-1). Principal component analysis(PCA) and partial least squares discrimination analysis(PLS-DA) of carbohydrate, nucleoside and amino acid showed that the water-soluble nutrients of the samples from Qinghai Province were significantly different from those from other areas mainly in asparagine, proline, glutamine, sucrose, adenine and guanosine. In this study, the compositions and contents of water-soluble nutrients in LBLs were preliminarily clarified, which provided basis for further development and utilization of LBLs resoures.

Construction of the expression vector for short-hairpin RNA-mediated Akt gene silencing in Lovo cells / 南方医科大学学报

<p><b>OBJEVTIVE</b>To construct a eukaryotic expression vector of short-hairpin RNA (shRNA) targeting human Akt gene and assess the effect of Akt gene silencing on the growth of colon cancer Lovo cells.</p><p><b>METHODS</b>Two shRNAs targeting human Akt gene were cloned into pENTRTM/U6 plasmid to obtain the entry clones, and the positive clones were verified by sequencing. After recombination of the pENTRTM/U6 entry constructs and Plenti6/Block-iT DEST vector, the positive clones were confirmed by sequencing. Lovo cells were transfected by the entry vector and DEST Vector, and RT-PCR and Western blotting were performed to detect the interference of Akt gene expressions.</p><p><b>RESULTS</b>The pENTRTM/U6 entry clones carrying Akt shRNA and pLenti6/DEST-pENTRTM/U6-Akt shRNA were successfully constructed. Both of the vectors were transfected into Lovo cells and resulted in obvious knockdown of the mRNA and protein expressions of Akt.</p><p><b>CONCLUSION</b>The Akt siRNA expression vector constructed can significantly inhibit Akt gene expression in Lovo cells, which facilitates further studies of Akt function and tumor gene therapy.</p>

Expression of neuron specific enolase gene in the brains of rats induced by iodine excess / 中国地方病学杂志

Objective To observe expression of neuron specific enolase (NSE) gene in the brain of rats induced by iodine excess. Methods One hundred and fifty one-month weaning Wistar rats were divided into ten groups according to 5 × 2 factorial experiment. Rats were fed with normal feedstuff and water of a series of iodine concentration by adding potassium iodide respectively: norrmal iodine (NI), five-fold high iodine (5HI), ten-fold high iodine(10HI), fifty-fold high iodine(50HI) and one hundred-fold iodine(100HI). After these rats were fed for three or six months, rat serum thyroid hormones were measured by radioimmunoassay including TT4, TT3, FT4, FT3, rT3 and the mRNA level of NSE in rat brain tissue was studied using RT-PCR technique. Results The levels of serum TT4 and TT3 were significantly different in five iodine level groups(F values were 18.867,27.287, both P < 0.01). The interaction between time and iodine level in TT4 was significant in our study(F values were 2.486, P < 0.05). The levels of TT4 and TT3 of 100 HI group at third and sixth month were lower than those of NI, 5HI, 10HI, 50HI groups in the same period (all P < 0.01). The levels of serum FT4, FT3 and rT3 were significantly different at different time(F values were 4.968,27.046,59.776 respectively, P < 0.05 or < 0.01) and in different iodine level groups(F values were 33.058,28.420,17.482 respectively, all P < 0.01). Moreover, the interaction between time and iodine level in FT3 and rT3 was significant in our study(F values were 6.894,5.233 respectively, both P < 0.01). FT4, FT3 and rT3 in 100HI group were lower than that of other iodine dosage groups at the same time (P < 0.05 or < 0.01). The levels of NSE mRNA in brain tissue was significantly different in five iodine level groups (F values were 29.006, P < 0.05). The levels of mRNA NSE of 100HI group in both three and six months (0.61 ± 0.19,0.61 ± 0.22) were all lower than that of any other groups[NI(0.73±0.13 and 0.72 ±0.26), 5HI (0.72 ± 0.15 and 0.72±0.16), 10HI (0.73 ±0.32 and 0.70±0.13), 50HI(0.71±0.18 and 0.69±0.31), all P < 0.05]. The results of correlation analyses show that the levels of serum FT3 and FT4 had correlations with the levels of NSE mRNA (P < 0.05) both in three and six months(r values were 0.987, 0.969 in three month, and 0.890, 0.910 in six month respectively). Conclusions The expression of NSE gene can tolerant the excess of iodine to a certain extent. Exposure to heavy excess iodine(100HI) can decrease the mRNA level of NSE gene. FT4 and FT3 may both have important roles on the regulation of NSE mRNA induced by excess iodine.

Overdose of iodine on expression of CCK gene in rat brains / 中华预防医学杂志

<p><b>OBJECTIVE</b>To observe the effect of overdose iodine on the expression of CCK gene in brains of rats and identify the possible mechanisms.</p><p><b>METHODS</b>One-month weaning Wistar rats were randomly divided into five groups which were fed with normal feedstuff and water supplemented with different concentrations of potassium iodide, named A group (iodine ration was about 6.15 microg per day), B group (iodine ration was about 30.75 microg per day), C group (iodine ration was about 61.5 microg per day), D group (iodine ration was about 307.5 microg per day) and E group (iodine ration was about 615 microg per day). Rats were sacrificed after being fed for three or six months. Then serum thyroid hormones were measured by radioimmunoassay and the mRNA level of CCK gene was studied by using RT-PCR technique.</p><p><b>RESULTS</b>At the end of three months, the values of thyroid hormones in E group [TT4 (45.2 +/- 13.7) nmol/L, TI'3 (0.65 +/- 0.20) nmol/L, FT3 (0.93 +/- 0.45) pmol/L, FT4 (7.07 +/- 2.43) pmol/L, rT3 (0.15 +/- 0.04) nmol/L] were all lower than those in A group [TT4 (76.0 +/- 18.8) nmol/L, TT3 (1.34 +/- 0.41) nmol/L, FT3 (2.45 +/- 0.62) pmol/L, FT4 (15.12 +/- 3.40) pmol/L, rT3 (0.24 +/- 0.04) nmol/L]. There were significant differences between E group and A group on the levels of serum TH (F values are 14.68, 16.03, 21.16, 20.25, 13.52 respectively, P < 0.01); FT3 levels in C and D groups were significantly decreased as compared to A and B groups (F = 21.16, P < 0.05). rT3 level in D group was significantly decreased compared with A,B and C groups (F = 13.52, P < 0.05). At the end of six months, the levels of serum TH in E group (TT4 (51.84 +/- 15.83) nmol/L, TT3 (0.77 +/- 0.22) nmol/L, FT4 (6.88 +/- 2.23) pmol/L, FT3 (0.74 +/- 0.28) pmol/L, rT3 (0.14 +/- 0.03) nmol/L) were lower than those in any other groups (F values were 6.05, 12.22, 11.25, 13.42, 5.89 respectively, P < 0.05). At the end of both three and six months, the mRNA levels of CCK gene in E group were lower than any other groups (F values were 4.04, 3.95 respectively, P < 0.01). The results of correlation analysis showed that serum FT4 had linear correlation with levels of CCK mRNA (r values were 0.990, 0.948 respectively; P < 0.05); However serum FT3 had no linear correlation with the levels of CCK mRNA (r values are 0.970, 0.932 respectively).</p><p><b>CONCLUSIONS</b>Exposure to overdose of iodine (iodine ration was 100-fold higher than that of A group) could decrease the mRNA level of CCK gene. Compared with FT3, FT4 might have more important role on the regulation of CCK mRNA induced by excess of iodine.</p>

Effects of various iodin-nutritional on activity of T4 5'-and 5-deiodinase in rat brain / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the changing of T4 5'-and 5-deiodinase within rat brain under various iodin-nutritional states.</p><p><b>METHODS</b>Animal model of iodine-deficiency rat was performed and the rats were divided into 4 groups by the intake of iodine-nutrition, and then killed at an age of 20 days. The thyroid hormones level in serum was measured by ELISA and the activity of T(4) 5'-and 5-deiodinase within brain was analyzed.</p><p><b>RESULTS</b>In less-iodine (LI) group,TT4 and FT4 were accounting for 3.5% of the neutral-iodine (NI) group's, and FT3 was 174.0% of NI group's (P < 0.05). In NI group,TT4 and FT4 were 114.5% and 127.7% of NI group's (P < 0.05). In high-iodine (HI) group, TT4 and FT4 were 61.86% and 62.0% of NI group's, and FT3 was 184.9% of NI group's (P < 0.05). In LI group, the activity of T4 5'-deiodinase tissue of per gram (1.95 +/- 0.32) ngT3.microgT4(-1).h was significantly higher than that of NI group (P < 0.05), and the activity of 5-deiodinase (1.38 +/- 0.21) ngrT3.microg T4(-1).h(-1) is significantly less than that of NI group (1.59 +/- 0.23) (P < 0.05). In HI group the activity of T4 5'-and 5-deiodinase tissue of per gram (1.12 +/- 0.19 and 1.73 +/- 0.36) ngrT3.microgT4(-1).h(-1)was significantly less than that of NI group (P < 0.05).</p><p><b>CONCLUSION</b>The activity of T4 5'-deiodinase in iodine deficiency heightens and that in iodine excess is debased, the activity of T4 5-deiodinase in iodine deficiency and in iodine excess is debased.</p>

A sandwich method of enzyme immunoassay for serum FT_4 / 中华内分泌代谢杂志

T_4 was coupled to human serum albumin(HSA)to make the conjugate T_4-HSA,a polyvalent T_4 analogue rather than monovalent T_4 per se alone.A new strategy for sandwich enzyme immunoassay model system of small molecular hapten hormones FT_4 was developed,such as intra-assay CV,inter-assay CV,average recovery, normal and abnormal values were fit for clinical application.The sensitivity was as much as 10 times higher than conventional competitive enzyme immunoassay.

Effects of different levels of iodine nutrition on liver typeⅠdeiodinase and brain typeⅡdeiodinase activities in rat / 中华内分泌代谢杂志

Wistar rats with different levels of iodine nutrition were killed after 3,6 and 12 months of experiments.Serum thyroid hormones were assayed with RIA.The activity of typeⅠdeiodinase(DⅠ)and typeⅡdeiodinase(DⅡ)was measured based on the release of radioiodide from the ~(125)Ⅰ-labeled substrate.The result showed that hypothyroidism reflected by decreased T_4 happened during the initial phase of iodine deficiency.The activity of DⅠand DⅡin rats was raised significantly in iodine deficiency groups.An excess of iodine inhibited DⅠactivity resulting in decreased serum TT_3 and FT_3.However,DⅡactivity increased in rats with iodine excess, attributing to the inactivation of T_3 and T_4 to the substrate of DⅡenzyme.