Association of mitochondrial haplogroup D and risk of esophageal cancer in Taihang Mountain and Chaoshan areas in China

Both the Taihang Mountain area in north-central China and Chaoshan area in the southeastern littoral of China are areas with high risk of esophageal cancer (EC). Our previous study confirmed that populations from the two areas might share similar matrilineal backgrounds and found that mitochondrial DNA (mtDNA) haplogroup D, especially subhaplogroups D4a and D5a, might be genetic background markers of EC in Chaoshan area. Here, to further determine whether D4a, D5a, and D might be susceptibility markers for EC in the two high-risk areas, we performed a case–control study with larger samples and analyzed the distributions of these three haplogroups in subjects (controls [n = 898] and patients [n = 768]) from the two areas. D4a haplogroup was significantly associated with increased risk of EC in Taihang Mountain subjects, especially women. D5 haplogroup was associated with EC at the general population level in the Taihang Mountain area and in subjects ≤ 60 years, especially women ≤ 60 years, in the Chaoshan area. D haplogroup was associated with EC only in subjects ≤ 60 years, especially men ≤ 60 years, in the Chaoshan area. D4a and D5 showing positive association with EC in the Taihang Mountain area became the predominant subhaplogroups of D in Chaoshan controls. In conclusion, D, D4a, and D5 haplogroups might be susceptibility markers for EC in the two high-risk areas in China, particularly D4a and D5 for the Taihang Mountain area and D and D5 for the Chaoshan area.     

Functional expression of human pyruvate carboxylase for reduced lactic acid formation of Chinese hamster ovary cells (DG44)

To investigate the effect of human pyruvate carboxylase (hPC) on lactate formation in Chinese hamster ovary (CHO) cell lines, FLAG-tagged hPC was introduced into a dihydrofolate-deficient CHO cell line (DG44). Three clones expressing high levels of hPC, determined by Western blotting using an anti-FLAG monoclonal antibody, and a control cell line were established. Immunocytochemistry revealed that a substantial amount of expressed hPC protein was localized in the mitochondria of the cells. hPC expression did not impair cell proliferation. Rather, it improved cell viability at the end of adherent batch cultures with the serum-containing medium probably because of reduced lactate formation. Compared with control cells, specific lactate production rate of the three clones was decreased by 21–39%, which was because of a decreased specific glucose uptake rate and yield of lactate from glucose. Reduced lactate formation by hPC expression was also observed in suspension fed-batch cultures using a serum-free medium. Taken together, these results demonstrate that through the expression of the hPC enzyme, lactate formation in CHO cell culture can be efficiently reduced.     

螺旋CT三维重建技术在胫骨平台骨折的诊疗应用分析

目的探讨螺旋CT三维重建在胫骨平台骨折中的临床应用。方法回顾性分析2007-2008年55例胫骨平台骨折病例．手术前均常规行X线摄片,行螺旋CT三维重建并与术中所见对照。结果所有病例螺旋CT三维重建明确地显示了骨折,并在骨折的分型和关节面碎裂情况的描述上较平片优越,与手术中所见一致。结论CT多种成像后处理技术可清晰显示骨折的部位、骨折线的走行方向、骨质碎裂程度和移位的距离以及关节面塌陷情况等,对术前分型、制订手术治疗方案具有重要的参考价值。     

Difference in microchip electrophoretic mobility between partially and fully PEGylated poly(amidoamine) dendrimers

The objective of this study was to investigate the difference in electrophoretic mobility between partially and fully poly(ethylene glycol)-conjugated poly(amidoamine) dendrimers (part-PEG-PAMAM and full-PEG-PAMAM, respectively) using a microchip capillary gel electrophoresis (MCGE). While MCGE allowed size-based separation of PEG-PAMAMs prepared with monomethoxy PEG-nitrophenyl carbonate, full-PEG-PAMAMs migrated slower than part-PEG-PAMAMs that were similar in size or larger. When the measured molecular weights obtained from MCGE analysis and the calculated molecular weights were plotted, each part-PEG-PAMAM and full-PEG-PAMAM showed correlation coefficients greater than 0.98. This study indicates that MCGE would be useful for characterizing PEG-PAMAMs with different PEGylation degrees.     

Circular RNA circ‐RCCD promotes cardiomyocyte differentiation in mouse embryo development via recruiting YY1 to the promoter of MyD88

Congenital heart disease (CHD) is the most common birth defect, affecting approximately 1% of live births. Genetic and environmental factors are leading factors to CHD, but the mechanism of CHD pathogenesis remains unclear. Circular RNAs (circRNAs) are kinds of endogenous non‐coding RNAs (ncRNAs) involved in a variety of physiological and pathological processes, especially in heart diseases. In this study, three significant differently expressed circRNA between maternal embryonic day (E) E13 and E17 was found by microarray assay. Among them, the content of circ‐RCCD increases with the development of heart and was enriched in primary cardiomyocytes of different species, which arouses our attention. Functional experiments revealed that inhibition of circ‐RCCD dramatically suppressed the formation of beating cell clusters, the fluorescence intensity of cardiac differentiation marker MF20, and the expression of the myocardial‐specific markers CTnT, Mef2c, and GATA4. Next, we found that circ‐RCCD was involved in cardiomyocyte differentiation through negative regulation of MyD88 expression. Further experiments proved that circ‐RCCD inhibited MyD88 levels by recruiting YY1 to the promoter of MyD88; circ‐RCCD inhibited nuclear translocation of YY1. These results reported that circ‐RCCD promoted cardiomyocyte differentiation by recruiting YY1 to the promoter of MyD88. And, this study provided a potential role and molecular mechanism of circ‐RCCD as a target for the treatment of CHD.     

High Performance Liquid Chromatography of Hydroperoxides Formed by Autoxidation of Vegetable Oils

Trilinoleoylglycerol (TL) was autoxidized at 37°C in the dark. Monohydroperoxides (MHP) obtained from the oxidized products were analyzed by high performance liquid chromatography (HPLC). Several peaks which appeared in the chromatogram were identified by infrared (IR), gas chromatography mass spectrometry (GC-MS) and enzymatic hydrolysis. Some positional and geometrical isomers of their hydroperoxy fatty acid components were separated using both absorption and reversed phase systems. Furthermore, 1-hydroperoxylinoleoyl-2,3-dilinoleoyl-glycerol and 1,3-dilinoleoyl-2-hydroperoxylinoleoylglycerol were partly separated by HPLC using an absorption system. MHP obtained from autoxidized corn oil, safflower oil and soybean oil were separated into some peaks by HPLC, although resolution into the individual isomers was incomplete. When oxidized oils were subjected to HPLC analysis directly, a linear relationship was observed between the peak areas of MHP and peroxide value in the range of 10 ~ 50 meq/kg.     

Root developmental responses to phosphorus nutrition

Phosphorus is an essential macronutrient for plant growth and development. Root system architecture (RSA) affects a plant's ability to obtain phosphate, the major form of phosphorus that plants uptake. In this review, I first consider the relationship between RSA and plant phosphorus-acquisition efficiency, describe how external phosphorus conditions both induce and impose changes in the RSA of major crops and of the model plant Arabidopsis, and discuss whether shoot phosphorus status affects RSA and whether there is a universal root developmental response across all plant species. I then summarize the current understanding of the molecular mechanisms governing root developmental responses to phosphorus deficiency. I also explore the possible reasons for the inconsistent results reported by different research groups and comment on the relevance of some studies performed under laboratory conditions to what occurs in natural environments.     

新疆维吾尔族妇女宫颈癌组织中乳头瘤病毒16型E6基因的克隆和序列分析

为了分析新疆南部地区维吾尔族妇女宫颈癌组织中HPV16型E6基因结构特点，从中国新疆南部地区维吾尔族妇女宫颈癌活检组织标本中提取DNA，以宫颈癌活检组织标本DNA为模板进行PCR扩增，获得HPV16 E6基因，将其克隆到pUCm-T载体上，并对其进行基因全序列分析.PCR检测结果显示宫颈癌组织中HPV16 E6阳性率为82.35%（14/17）；测序结果显示，新疆株HPV16 E6基因全长456 bp，大小与德国标准株一致.E6基因的第247位碱基发生T→G突变，并由此引起所编码的氨基酸亦发生改变.上述结果表明，中国新疆南部地区维吾尔族妇女宫颈癌患者组织中HPV16 E6的基因结构与德国标准株HPV16 E6基因之间存在差异.