大气污染对35种园林植物生长的影响

对广东省佛山市大气监测的结果表明,酸性硫化物和毒性氟化物是陶瓷工业产生的主要污染物质。采用现场盆栽试验方法。比较分析了生长在佛山市陶瓷城附近高浓度SO2和氟化物大气污染环境下的35种园林绿化植物的株高、基径、冠幅等生长指标的差异,并采用综合生长指标评价方法对参试植物进行相应的抗性分级,选出8种抗性植物（铁冬青、菩提榕、环榕、仪花、小叶榕、红花油茶、幌伞枫、白桂木）,17种中等抗性植物（小叶胭脂、腊肠树、毛黄肉楠、红桂木、茶花、吊瓜、火焰木、铁力木、柳叶楠、猫尾木、灰莉、密花树、海南红豆、复羽叶栾树、灰木莲、大头茶、印度紫檀）,8种敏感植物（华润楠、海南木莲、格木、日本杜英、蓝花楹、观光木、蝴蝶树、白木香、乐昌含笑、无忧树）。     

Endothelin-1 and insulin induce cellular inactivation of protein kinase FA/glycogen synthase kinase-3α in a common signaling pathway

In this study, we investigate the effects of endothelin-1 (ET-1) and insulin on the cellular activity of protein kinase F_A/glycogen synthase kinase-3 (kinase F_A/GSK-3) in rat adipocytes. The cellular activity of kinase F_A/GSK-3 is inhibited to 50% of control within 30 min when cells are treated with 1 nM ET-1 at 37°C; in addition, significant inhibition to 60% of control is observed at as low as 1 pM ET-1. Conversely, ET-1 at concentrations up to 1 nM has no direct effect on purified kinase F_A/GSK-3 in vitro. Immunoblotting analysis further reveals that the protein level of this kinase is not significantly changed when treated with 1 nM ET-1 for 30 min. Similar to ET-1, insulin as low as 10 nM can also induce inactivation of kinase F_A/GSK-3 to 50% of control in adipocytes when processed under identical conditions. Most importantly, when treated with both insulin and ET-1, the activity of kinase F_A/GSK-3 can be decreased only to 50% of control. Taken together, the results provide initial evidence that ET-1 and insulin may regulate this important multisubstrate/multifunctional protein kinase in a common signaling pathway in cells.     

Beta-adrenergic mechanisms in arterial hemodynamics: A comparison between normotensive and hypertensive rats

The purpose of this study was to determine whether -adrenergically mediated cardiovascular functions such as arterial pressure (AP), heart rate (HR), stroke volume (SV), cardiac output (CO), peripheral resistance (R_p), arterial impedance (Z_c), mean arterial compliance (C_m) and pulse wave reflection (P_b) were altered in the spontaneously hypertensive rat (SHR) compared to the normotensive Wistar Kyoto rat (WKY). In pentobarbital-anesthetized and artificially ventilated rats, the aortic pressure wave was recorded with a high-fidelity Millar sensor, and aortic flow wave with an electromagnetic flow probe. The pressure and flow waves were subjected to Fourier transform so as to analyze impedance spectra. Acute -adrenergic blockade was produced by an intravenous injection of propranolol (nonselective) and atenolol (selective ₁-blocker) at doses of 2 and 5 mg/kg, respectively. Steady-state parameters were obtained 15–20 min after intravenous administration. The SHR had higher AP, HR, R_p and Z_c than the WKY. SV and CO remained unaltered while C_m was lower. In response to propranolol, the mean AP was increased by 7 mm Hg in the WKY, but did not change in the SHR. Moreover, significant decreases occurred in HR, CO and C_m in addition to increases in R_p, Z_c and P_b. These changes between the SHR and WKY were only slight. Atenolol caused decreases in AP, HR and CO in both SHR and WKY, but did not significantly alter the R_p, Z_c, C_m and P_b. Again, the atenolol-induced changes in AP, HR and CO did not appear to be significantly different between SHR and WKY. The results indicate that -adrenergic effects on the heart, Windkessel and resistance vessels are neither greatly enhanced nor impaired during the development of hypertension. In the hypertensive state, significant -adrenergic mechanisms still exert tonic vasodilatory effects on the large and small arterial system.     

Oligo-N-acetyllactosaminoglycans bearing Galβ1-4(Fucα1-3)GlcNAc sequences reveal lower affinities than their nonfucosylated,or α(1-2) fucosylated counterparts for immobilized wheat germ agglutinin

Relative affinities of several fucosylated and nonfucosylated oligo-N-acetyllactosaminoglycans for immobilized wheat germ agglutinin (WGA) were studied using a chromatographic technique. (1-3) Fucosylation of theN-acetylglucosamine unit(s) in mono- and biantennary saccharides of the Gal1-4GlcNAc-R type strongly reduced the WGA-affinity. In contrast, (1-2) fucosylation of the nonreducing galactose unit(s) of the saccharides did not reduce the affinity.     

与BT型细胞质雄性不育水稻相关联的双链RNA

以改进的Kemble′s方法提取BT型水稻细胞质雄性不育系及相应保持系线粒体核酸,在电泳分离后的不育系线粒体核酸中发现一特异双链RNA(dsRNA)分子,进一步实验表明,它是线粒体外的成份。与真菌中普遍发现的dsRNA病毒类颗粒(virus-like particles,VLP)相似,这种颗粒也能以细胞质遗传的方式稳定遗传。在表现为杂种优势的F_1代(不育系×恢复系)也发现有这种颗粒,但在F_1代黄化苗相对成熟的基部,此颗粒相对线粒体有减少的趋势,推测是因为F_1核背景不适合此VLP的生存而逐渐被排斥。电镜观察估测dsRNA分子量为6.0×10~6。这种VLP在BT型水稻细胞质雄性不育系中的普遍存在及其遗传行为表明其与不育可能有关。     

Embryonic and post-embryonic lethals induced by diethyl sulfate in mature sperm of Drosophila melanogaster.

It has recently been reported that, in Drosophila melanogaster, when sperm treated with diethyl sulfate was stored in the females, II–III translocations were detected as from the 6th day after the treatment, though none was recovered without storage. Chromosome breaks being currently considered the main cause of dominant lethality and the embryonic period lasting about one day at 25°C, it was thought of interest to study the ability of DES to induce this type of damage with and without storage. It was found that the treatment increased embryonic lethality (measured as frequency of unhatched eggs) and post-embryonic lethality (measured as frequency of larval and pupal death) over the control values. The frequency of embryonic lethals after storage in the females for 6 days was similar to that shown by the unstored samples. In contrast with this, the yield of post-embryonic lethality was markedly raised by that storage time. It is suggested that: (1) lesions are induced as “pre-breaks”, and storage and cell divisions are instrumental in their opening; (2) potential breaks can undergo DNA replication and cell division as such and become open in different cell cycles, impairing embryonic and post-embryonic development; (3) chromosome breaks induced by DES seem to behave in a way similar to those induced by other mono- and poly-functional alkylating agents; and (4) when the potential ability of chemical compounds to induce chromosome breaks is assessed, post-embryonic lethality can be used as a simple one-generation preliminary test, to establish delayed effects.     

Antennulary sensory organs in cyprids of Octolasmis and Lepas (Crustacea: Thecostraca: Cirripedia: Thoracica): a scanning electron microscopic study

Cypris larvae of the pedunculate barnacles Octolasmis angulata (Poecilasmatidae), Lepas australis, L. pectinata, and Dosima fascicularis (Lepadidae) were studied with scanning electron microscopy, focusing on the sensory setae and the attachment disc on the antennules. The antennules of O. angulata did not exhibit any remarkable trait, but carry the same number of setae as seen in most other thoracicans. The third segment is bell-shaped and quite distinct from the second and its attachment disc is surrounded by a skirt. We found several potential synapomorphies in antennulary morphology between cyprids of the lepadid species but none of them were shared with the cyprids of Octolasmis; the list of unique lepadid characters includes: one additional, preaxial seta on the second segment; multiple similar (up to eight) postaxial setae (PS3) on the third segment, unlike all other thoracicans, where there is only a single PS3; the third segment consists almost entirely of the attachment disc, which is distended and surrounded by two parallel rows of radial setae; on the fourth segment the terminal seta E is diminutive. We found no traits in cyprids of Octolasmis that seem to be adaptations to their attachment site within the branchial chamber of swimming crabs and, in particular, no similarities with cyprids of rhizocephalan barnacles, many of which also attach in the gill chamber. The synapomorphies between cyprids of the lepadid species may be adaptations to their life in the neuston.     

着床期小鼠子宫内膜Le~y糖蛋白的动态变化

为了解子宫内膜Ｌｅ~ｙ糖蛋白在胚泡着床期间的变化,以及与胚泡表面阶段特异性Ｌｅ~ｙ抗原出现的关系,应用对Ｌｅ~ｙ寡糖特异的ＡＨ－６单抗为探针,通过ＳＤＳ－ＰＡＧＥ和Ｗｅｓｔｅｒｎｂｌｏｔ免疫酶标染色,观察了小鼠子宫内膜Ｌｅ~ｙ糖蛋白在着床期的动态变化和分布特点。结果表明：（１）未孕及着床前后的小鼠子宫内膜均含Ｌｅ~ｙ糖蛋白Ｍｒ５０～２００ｋＤ）,未孕内膜的含量明显高于着床期间的样品;（２）在着床日（Ｄ４）样品可见微量１６ｋＤ的Ｌｅ~ｙ糖蛋白条带;（３）未孕至Ｄ４的子宫内膜均有Ｌｅ~ｙ糖蛋白分泌至宫腔,但呈渐减趋势,未孕样品Ｌｅ~ｙ糖蛋白主要为分泌型,而Ｄ４样品Ｌｅ~ｙ糖蛋白主要存在于子宫内膜,宫腔液含量很少;结果提示子宫内膜Ｌｅ~ｙ糖蛋白在着床期间具有含量、组成和分布上的动态变化,这些变化可能与胚泡着床以及胚泡在宫腔内其表面Ｌｅ~ｙ糖抗原转为阳性密切有关。     

Amyloid-β aggregates induced by β-cholesteryl glucose-embedded liposomes

Senile plaques that is characterized as an amyloid deposition found in Alzheimer's disease are composed primarily of fibrils of an aggregated peptide, amyloid β (Aβ). The ability to monitor senile plaque formation on a neuronal membrane under physiological conditions provides an attractive model. In this study, the growth behavior of amyloid Aβ fibrils in the presence of liposomes incorporating β-cholesteryl-D-glucose (β-CG) was examined using total internal reflection fluorescence microscopy, transmittance electron microscopy, and other spectroscopic methods. We found that β-CG on the liposome membrane induced the spontaneous formation of spherulitic Aβ fibrillar aggregates. The β-CG cluster formed on liposome membranes appeared to induce the accumulation of Aβ, followed by the growth of the spherulitic Aβ aggregates. In contrast, DMPC and DMPC incorporated cholesterol-induced fibrils that are laterally associated with each other. A comparison study using three types of liposomes implied that the induction of glucose contributed to the agglomeration of Aβ fibrils and liposomes. This agglomeration required the spontaneous formation of spherulitic Aβ fibrillary aggregates. This action can be regarded as a counterbalance to the growth of fibrils and their toxicity, which has great potential in the study of amyloidopathies.     

An apigenin-induced decrease in K-antigen production by Sinorhizobium sp. NGR234 is y4gM- and nodD1-dependent

Cultured cells of Sinorhizobium sp. NGR234 produce an abundance of capsular polysaccharides, or K antigens; however, cells that are cultured in the presence of apigenin, a nod gene inducer, exhibited a significant reduction in K-antigen production. The flavonoid-induced modulation in capsule production appeared to be related to the phase-shift changes associated with bacteroid differentiation. Therefore, the polysaccharides were extracted from Sinorhizobium sp. NGR234 bacteroids recovered from Vigna unguiculata cv Red Caloona root nodules, and subsequent analyses showed that the bacteroid extracts were virtually devoid of K-antigen. Polysaccharide extracts from two nodulation mutants cultured in the presence of apigenin were then analyzed, and the results showed that the flavonoid-inducible decrease in K-antigen production is y4gM- and nodD1-dependent.