Identification of soybean mosaic, southern bean mosaic and tobacco ringspot viruses from soybean in the People's Republic of China

Samples of soybean plants with virus-like symptoms were collected from several locations in the People's Republic of China in 1981. These samples were used to prepare inocula for mechanical inoculation to soybean. Twenty-one virus cultures were obtained, the identities of which were determined by serology, symptomatology and host range. Sixteen cultures contained only soybean mosaic virus, four of which were more pathogenic than any previously studied; one culture contained only tobacco ringspot virus, another only southern bean mosaic virus, and three other cultures mixed infections of soybean mosaic and southern bean mosaic viruses. This is the first report of the occurrence of tobacco ringspot virus and southern bean mosaic virus in soybean in the People's Republic of China.     

Phosphorylation of the oligosaccharide of uteroferrin by UDP-GlcNAc:glycoprotein N-acetylglucosamine-1-phosphotransferases from rat liver, Acanthamoeba castellani, and Dictyostelium discoideum requires alpha 1,2-linked mannose residues

We have investigated the oligosaccharide requirements of the UDP-GlcNAc:glycoprotein N-acetylglucosamine-1-phosphotransferases from rat liver, Acanthamoeba castellani, and Dictyostelium discoideum. Uteroferrin, an acid hydrolase, was phosphorylated by the three N-acetylglucosaminylphosphotransferases, and the phosphorylated oligosaccharides were isolated and analyzed by ion suppression high performance liquid chromatography. In all three cases, the phosphorylated species contained 6 or more mannose residues. Phosphorylation of the Man5GlcNAc2 oligosaccharide could not be detected even though this was the major species on the native uteroferrin. The Man5GlcNAc2 oligosaccharides lack alpha 1,2-linked mannose residues, whereas the larger oligosaccharides contain 1 or more mannose residues in this linkage. Treatment of intact uteroferrin with an alpha 1,2-specific mannosidase-generated molecules whose oligosaccharides consisted almost entirely of species with 5 mannose residues. The N-acetylglucosaminylphosphotransferases could no longer phosphorylate such molecules. These data indicate that at least 1 alpha 1,2-linked mannose residue must be present on uteroferrin's oligosaccharide for phosphorylation to occur.     

Application of intracellular ATP determination in lymphocytes for HLA-typing

The amount of adenosine triphosphate (ATP) in human lymphocytes was determined using a technique based on light emission from a bioluminescent reaction with luciferin-luciferase. The amount of ATP changed when cells were incubated in the presence of specific HLA antisera and complement. For determination of intracellular ATP a modified method was applied, which was based on reduction of extracellular ATP by the addition of ATPase. The results of titration of an anti-human lymphocyte serum using the bioluminescence assay were in agreement with the results of fluorescence vitality staining. Bioluminescent HLA-determination in 57 cell samples each tested with 5 different antisera also gave good agreement (95.8%) with the conventional method. From these experimental data the calculated ATP content per lymphocyte was 0.135 ± 0.058 pg ATP.     

Selective induction of coumarin 7-hydroxylase by pyrazole in D2 mice

Pyrazole, was given to DBA/2N (D2), C57BL/6N (B6) and AKR/N mice to study its effects on hepatic drug metabolism. A decrease in the total amount of microsomal cytochrome P-450 as well as in the activities of ethylmorphine demethylase and benzo[a]pyrene hydroxylase was found. On the other hand ethoxycoumarin de-ethylase was increased 1.5-2.5-fold (depending on the strain of mouse) and coumarin 7-hydroxylase as much as sevenfold (but only in D2 mice) after pyrazole treatment. This increase was much higher than that caused by phenobarbital, the only well known inducer of coumarin 7-hydroxylase. By reconstituting the mono-oxygenase complex after purification of cytochrome P-450 we found a 40-fold increase in coumarin 7-hydroxylase and eightfold increase in ethoxycoumarin de-ethylase after pyrazole treatment. This was found only in D2 mice. An antibody previously developed against a cytochrome P-450 fraction from the the D2 strain with a high coumarin 7-hydroxylase activity inhibited the microsomal coumarin 7-hydroxylase almost 100% after pyrazole pretreatment of the animals. In the case of control or phenobarbital-treated mice the inhibition was somewhat weaker. With the reconstituted mono-oxygenase complex the inhibition of coumarin 7-hydroxylase was almost 100% both for control and pyrazole-treated D2 mice. The data indicate that pyrazole causes an induction of the microsomal monooxygenase complex different from that caused by phenobarbital or 3-methylcholanthrene and selective for coumarin 7-hydroxylation or 7-ethoxycoumarin de-ethylation. This induction was strong in D2, weak in B6 and absent in AKR/N mice.     

安定减低家兔膈神经放电幅度的机制分析

本实验室曾经报道静脉注射安定对于清醒、麻痹、人工呼吸的家兔具有减低膈神经放电幅度、加快呼吸频率,缩短吸气时程(T_I)和呼气时程(T_E),降低动脉血压等作用。本工作在35只家兔中进一步分析了某些药物对安定的这些作用的影响。GABA 降低膈神经放电幅度和动脉血压,这与安定的作用相同,但 GABA 延长T_I、T_E和减慢呼吸频率,与安定的作用相反。事先用氨基酸脱羧酶抑制剂异烟肼处理,或用 GABA 受体拮抗剂印防己毒素处理,可阻遏安定减低膈神经放电幅度的作用。在事先用印防己毒素处理的家兔中,可见安定缩短 T_IT_E的作用不受影响。异烟肼或印防己毒素还能部分对抗安定的降压效应。阿片受体拮抗剂纳洛酮和5-HT 受体拮抗剂赛庚啶都不能阻遏安定降低膈神经放电幅度和动脉血压的作用。上述结果提示安定降低膈神经放电幅度的作用可能通过 GABA 这一中间环节,而内啡肽和5-HT可能不起重要作用。安定的降压作用需要有内源性 GABA 参与才得以持续较长时间,在减少GABA 或阻断 GABA 受体后,安定只有短暂的降压作用。     

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。     

苯胺嘧啶衍生物X-9通过下调整合素β1表达抑制肝细胞癌迁移侵袭

整合素在许多肿瘤细胞中高表达,并且参与肿瘤细胞的侵袭转移。在肝细胞癌中,整合素β1被报导高表达,并促进肿瘤细胞的侵袭。目前,对于整合素的表达调控癌细胞机制以及干预其表达进而抑制肿瘤细胞转移的研究较少。本研究探讨利用小分子化合物抑制整合素表达来抑制肿瘤细胞迁移和侵袭的可能。首先,对临床肝癌细胞患者癌组织和癌旁组织中的整合素β1的表达进行检测,发现其在癌组织中的表达显著高于癌旁组织（P<0.05）。对TCGA肿瘤数据库的生物信息学分析结果同样显示,整合素β1的高表达与肝癌的分期（P=0.019）和预后（P=0.013）相关。通过筛选发现,苯胺嘧啶衍生物X09可以抑制肝癌细胞中整合素β1的mRNA和蛋白质的表达（P<0.01）。细胞划痕愈合实验和细胞穿孔实验结果显示,苯胺嘧啶衍生物X-9能够抑制肝癌细胞的迁移和侵袭（P<0.01）。进一步的研究证实,在肝癌细胞中外源表达整合素β1可以逆转X-9对肝癌细胞迁移和侵袭的抑制;而在敲低整合素β1的细胞中,X-9对细胞的迁移和侵袭的抑制被消除。因此,鉴定出苯胺嘧啶衍生物X-9可以通过下调整合素β1表达,进而抑制肝癌细胞的迁移和侵袭。     

Eutrophication of Lakes Leman and Neuchâtel (Switzerland) indicated by oligochaete communities

In 1978–80, oligochaete communities of meso-eutrophic Lake Léman (Lake of Geneva) were compared to those of mesotrophic Lake Neuchâtel. Worm species were classified into three groups corresponding to their increasing tolerance to eutrophication: (1) oligotrophic species, mostly Peloscolex velutinus, Stylodrilus heringianus; (2) mesotrophic species, mostly Potamothrix vejdovskyi, P. bedoti; (3) eutrophic species, mostly Potamothrix hammoniensis, P. heuscheri, Tubifex tubifex. In both lakes, eutrophic species constituted the bulk of the communities in terms of absolute abundance. However, relative abundance of mesotrophic and eutrophic species was higher in Lake Léman; oligotrophic species were more important in Lake Neuchâtel. These data confirmed the trophic classification of lakes based on chemical parameters. The number of zero values, which perturbated statistical analysis, was reduced by using species groupings instead of isolated species. Thus, making the lakes more comparable even if different species were present in each one. Relative density values based on all samples were distributed among 4 density classes for the 3 species groupings. The 12 resulting frequencies described the community structure expressed in terms of eutrophication. Furthermore, these frequencies may be used for comparison of eutrophication levels in several lakes.     

Angiotensin biosynthesis and concentrations in brain of normotensive and hypertensive rats

We report here on the extraction and characterization of angiotensin I (ANG I) and angiotensin II (ANG II) from the brain of rats. High pressure liquid chromatography (HPLC) with different mobile phases combined with specific radioimmunoassays (RIA) proved to be a powerful tool for peptide characterization in biological samples; (Ile5)-ANG I, (Ile5)-ANG II and (Ile5)-ANG III could clearly be identified in cerebrospinal fluid (CSF), incubated in vivo and in vitro with renin, in total brain extracts, as well as in hypothalamus (HT), medulla oblongata (MO), cerebellum (CER) and cortex (CO). Angiotensin cleaved from CSF angiotensinogen and angiotensin extracted from brain showed retention times identical to those of plasma angiotensin and synthetic standard peptides, indicating that their amino acid sequence is probably identical. ANG I and ANG II were highest in the HT and lowest in the CO. Following bilateral nephrectomy (NX) both ANG I and ANG II persisted at control levels. Young 10 week old spontaneously hypertensive rats (SHRSP) showed significantly lower ANG I and ANG II concentrations in the HT compared with Wistar Kyoto rats (WKY). Intracerebroventricular (i.c.v.) administration of the converting enzyme inhibitor captopril caused a significant increase in ANG 1 in nephrectomized SHRSP but not in WKY. These differences were not found in 40 week old SHRSP. The data show that ANG I and ANG II are synthetized in the brain of rats. The lower concentrations and the enhanced accumulation of ANG I after converting enzyme blockade in nephrectomized young SHRSP indicate an increased turnover of angiotensin in hypertensive rats.