Synthesis of new olean-18(19)-ene derivatives from allobetulin

New olean-18(19)-ene triterpenoids were effectively synthesized by the interaction of allobetulin or its acetate with phosphorous oxychloride in refluxing pyridine. The structures of the synthesized 17-chloromethyloleane-18(19)-enes were confirmed by NMR spectroscopy and X-ray analysis.     

Effect of carbon disulphide on the cardiovascular system

Biochemical, histological and electron-microscopic examinations of the heart and the aorta of albino rats exposed to carbon disulphide in concentrations of 10, 50, 100 and 200 mg . m-3 were carried out. Changes in the metabolic and energetic processes in the myocardium and in the quantitative and qualitative characteristics of the connective tissue of the aortal vessel wall were observed. The established disorders follow the dose-effect dependence. The authors studied the effect of carbon disulphide in concentrations of 10 and 50 mg . m-3 on the electrophoretic spectrum of serum proteins, the quantitative and qualitative characteristics of fibrous structures in the myocardium and the aorta of albino rats fed on atherogenic diet (cholesterol, cholic acid and vitamin D2). The combination of carbon disulphide with the atherogenic factor leads to intensification of changes in the cardiovascular system and in serum proteins, observed after independent exposure to either of the factors. The combination of atherogenic diet and 10 mg . m-3 carbon disulphide induced symptoms of intoxication, decreased survival of the animals, and the developing sclerotic process was found to be more severe and to progress more rapidly than in animals subject to atherogenic diet alone. The obtained results testify to cardiovascular effect of carbon disulphide. The observed atherogenic effect of carbon disulphide in low concentrations is most probably connected with its direct effect on the myocardium and the vessels.     

Development of a system vector-host in methylotrophic bacteria

Cloning of methylotropic and other Gram negative bacteria's genes was performed using vectors derived from IncP4 plasmids. Plasmids, such s RSF1010 are 8.8 kb in length, have a high copy number and broad host range and can be mobilized efficiently by a number of conjugative plasmids. IncP4 plasmids have relatively few restriction enzyme's targets suitable for cloning. In this paper the construction of versatile and special purpose IncP4 vectors available for cloning DNA into broad range of bacterial species are described. The seria of versatile vectors involves the transposon containing plasmid and two-replicon vectors.In genetic construction of special vector for direct cloning of restriction fragments the genetic regulation elements of Tn 1 were used. On the base of IncP4 replicon special vectors for construction of bank genes (cosmids) and the vectors for cloning of regulation sequence were also constructed.     

MSI2通过下调circRNA_001214促进急性髓系白血病细胞HL60生长

Musashi-2（MSI2）是一种RNA结合蛋白质,对维持造血干细胞功能具有重要作用。研究表明,MSI2高表达能促进急性髓系白血病（acute myelocytic leukemia, AML）进展,但其作用机制尚不明确。本研究稳定沉默HL60细胞MSI2后,第1、2、3、4 d对照组的相对细胞生长率分别为1.931 ± 0.027、3.070 ± 0.073、4.017 ± 0.092和4.215 ± 0.246;敲减组分别为1.927 ± 0.035、2.564 ± 0.090、2.825 ± 0.097和3.223 ± 0.182,两组相比具有统计学差异,P<0.001;细胞凋亡明显增加(7.967% ± 0.698% vs 3.400% ± 0.322%., P<0.01);G₀/G₁期细胞比例明显增高（67.430% ± 4.390% vs. 50.360% ± 2.160%, P<0.01）;NUMB蛋白明显上调,LEF1明显下降。环状RNA（circular RNA, circRNA）芯片筛选和荧光定量PCR验证显示,MSI2沉默组circRNA_001214表达水平是对照组3.48倍。这一结果也在NALM6细胞得到证实。进一步用生物信息学分析,显示circRNA_001214最可能与miR-1273a、miR-1273e和miR 5095结合,进而影响参与细胞凋亡相关基因（CYCS、AKT1、BAX、TNFRSF10A、TNFRSF10D）、Wnt信号基因（WNT4、WNT2B、WNT7B、 DKK2、SFRP1、CSNKE1和LEF1）以及参与细胞代谢相关基因（RPE, PGAM4, PGAM1, TAT, CBS、RPE、SUCLG2、PGAM4、PGAM1和 IDNK）。总而言之,MSI2可能通过干扰circRNA_001214生成,减少靶miRNA对凋亡、Wnt信号及细胞代谢相关基因表达的影响,促进细胞生长。     

慢性心功能不全大鼠心脏和血淋巴细胞β-肾上腺素受体的改变

在主动脉与肾动脉缩窄造成的慢性心功能不全大鼠,血浆儿茶酚胺浓度增高;心脏β-肾上腺素受体(β-AR)数量增加,其中β_1-AR及其mRNA增加,而β_2-AR及其mRNA不变;左心房异丙基肾上腺素(ISO)浓度-收缩效应曲线右移;而心肌ISO浓度-cAMP蓄积曲线无显著改变;血淋巴细胞β-AR数量显著减少.结果提示心功能不全时心脏β_1-AR数量增多,但其介导的正性变力效应反而降低,在cAMP生成以后的信号转导过程或心肌收缩成分功能存在障碍,而血淋巴细胞β-AR的改变与心脏β-AR的功能改变平行.     

The character of protein-nucleic interaction in relation to the mtDNA-membrane complex

Summary Specific sites that interact with structural proteins of the mitochondrial inner membrane were found in mitochondrial DNA (mtDNA) of rat liver. Analysis of the isolated DNA fragments revealed their capacity to form a complex with membrane proteinsin vitro and allowed the detection of a protein with a molecular weight 40,000. The size of the fragments was found to be 12–18 nucleotide pairs with an average molecular weight 10,000 MtDNA sites recognized by membrane protein proved to be quite unique in having a secondary structure, a high content of AT sequences (82%) and oligopyrimidine blocks. It was shown that the light mtDNA strand, rich in adenine, is 60% more active in the binding with membrane mitochondria than the heavy one.     

FXR在胃粘膜肠化生及胃癌中的表达及其意义研究

目的:研究FXR在胃炎,胃粘膜肠化生及胃癌组织中的表达,分析其在胃癌发生中的意义。方法:采用免疫组化方法检测FXR在55例胃炎组织,61例胃黏膜肠化生组织及61例胃癌组织中的表达,利用统计学方法 SPSS17.0软件分析其在三种组织中的表达变化,结合文献回顾,分析FXR在胃癌发生中的意义。结果:FXR在胃黏膜肠化生中的表达明显高于胃炎组织(P0.05),而在胃癌组织中,FXR的表达显著低于胃粘膜肠化生组织(P0.05)。结论:FXR是一个潜在的胃癌发生生物标记物,其具体机制有待于进一步探索。