Ascorbic acid analogue 6-Deoxy-6-[18F] fluoro-L-ascorbic acid as a tracer for identifying human colorectal cancer with SVCT2 overexpression

L-ascorbic acid (AA) was reported to have an anti-cancer effect over 40 years. In recent years, several ongoing clinical trials are exploring the safety and efficacy of intravenous high-dose AA for cancer treatment. The lack of appropriate imaging modality limits the identification of potentially suitable patients for AA treatment. This study focuses on identifying AA-sensitive tumor cells using molecular imaging. 6-Deoxy-6-[¹⁸F] fluoro-L-ascorbic Acid (¹⁸F-DFA), a structural analog of AA, was synthesized and labeled to visualize the metabolism of AA in vivo. Colorectal cancer (CRC) cell lines with high and low expression of sodium-dependent vitamin C transporters 2 (SVCT2) were used for a series of cellular uptake tests. PET imaging was performed on xenograft tumor-bearing mice. More AA uptake was observed in CRC cells with high SVCT2 expression than in cells with low SVCT2 expression. The substrate (unlabeled AA) can competitively inhibit the ¹⁸F-DFA tracer uptake by CRC cells. The biodistribution of ¹⁸F-DFA in mice showed high radioactivity was seen in organs such as adrenal glands, kidneys, and liver that were known to have high concentrations of AA. Both PET imaging and tissue distribution showed that cancer cells with high SVCT2 expression enhanced the accumulation of ¹⁸F-DFA in mice after tumor formation. Immunohistochemistry was used to verify the corresponding results. As a radiotracer, ¹⁸F-DFA can provide powerful imaging information to identify tumor with high affinity of AA, and SVCT2 can be a potential biomarker in this process.     

Electrophoretic and morphological comparisons in ten rain forest species of Shorea (Dipterocarpaceae)

Differences identified by electrophoretic separation of enzymes and other proteins are providing increasing informative for the study of evolutionary affinities within a genus. Zymogran compared with a scheme of putative affinities derived from a standard taxonomic classi based on consciously weighted morphological characters, as well as with indices of similarity on an array of morphological criteria relating to twigs, stipules, leaves, inflorescences and structure for 10 species of Shorea from southeast Malaysia. Shorea ovalis is placed in a separate of the genus from the other nine species; S. leprosula, S. parviflia and S. curtisii are related other on R^p data and a high degree of similarity is shown between these three spec S. dasyphylla .     

不同训练负荷太极拳运动对早中期帕金森病患者康复疗效

目的 通过对比对照组和太极拳运动组，评价太极拳运动在早中期帕金森病患者康复作用。方法 45例帕金森病患者随机分为：对照组（n=15），不接受干预；太极拳1组（n=15）采用24式简化太极拳练习，40 min/次，3次/周；太极拳2组（n=15）采用24式简化太极拳练习，60 min/次，3次/周。在基线、12周、24周运动后采用患者跌倒功效量表（FES）、起立-行走计时测试（TUGT）、Berg平衡量表评分（BBS）、统一帕金森病评定量表（UPDRS） Ⅲ评分、汉密尔顿焦虑抑郁量表评分（HAMD、HAMA）、匹兹堡睡眠质量指数评分（PSQI）进行评估。结果 太极拳1组，24周对比基线在TUGT、BBS评分的改善上有统计学意义（P<0.05）。太极拳2组，24周对比基线在TUGT、 BBS评分的改善上有统计学意义（P<0.05）,24周对比12周在TUGT的改善上有统计学意义（P<0.05）。结论 太极拳运动可以改善早中期帕金森病患者的平衡障碍，可降低跌倒风险。     

Phylogeographic and demographic effects of Quaternary climate oscillations in Hexinia polydichotoma (Asteraceae) in Tarim Basin and adjacent areas

In order to investigate the genetic diversity and influence of climate oscillations on evolutionary processes of organisms in Northwest China, we selected Hexinia polydichotoma, a species endemic to China, and examined the phylogeographic structure and historical factors that influenced the evolutionary history of this species in its entire cover range, Tarim Basin and adjacent areas. In the study, 17 haplotypes were identified in H. polydichotoma on the basis of two chloroplast DNA sequences (trnH–psbA and ycf6–psbM). Shown in the network, the two common haplotypes, A and D, respectively, mainly distribute along the northern and southern rims of the basin. The analyses of molecular variance analysis suggest that genetic variation primarily occurs among populations, and all populations were subdivided into five groups by SAMOVA. Geographic range expansion along the southern and northern rims of the basin was supported by the significant value for Tajima’s D and by the unimodal mismatch distribution. It is possible that during the interglacial period of the middle Pleistocene, a large amount of snow and glacial ice melted from the mountains surrounding Tarim Basin. This increased water, the expanding desert, and the dispersal ability of H. polydichotoma were important factors driving not only geographic range expansion, but also the current phylogeographic structure of this species. It is possible that during the middle Pleistocene, the climatic fluctuations resulted in expansion and contraction cycles of river systems and oases, and may consequently have caused population fragmentation.