The Presence of (+)-S-Adenosyl-l-Methionine in the Rat Brain and Its Lack of Effect on Phenylethanolamine N-Methyltransferase Activity

Abstract: (+)-S-Adenosyl- l -methionine [(+)-SAM] was isolated from rat brain and was quantified by HPLC followed by UV spectrophotometric measurements and by ¹H-NMR. Its estimated ratio in brain is 3% of total SAM. Because of its commercial unavailability, (+)-SAM was also prepared from chemically synthesized SAM by separation of the two diastereoisomers on a preparative reverse-phase Nucleosil C8 column. The (+) diastereoisomer thus obtained was then assayed in vitro both as an inhibitor and a substrate of phenylethanolamine N -methyltransferase. Enzymatic activity was measured by HPLC analysis. It was shown that (+)-SAM has no effect on phenylethanolamine N -methyltransferase activity; therefore, it is unlikely that (+)-SAM plays any possible role in regulation of adrenaline synthesis in the brain.     

Action of α-l-fucoside fromOctopus vulgaris hepatopancreas on phospholipid vesicles containing the fucosylated ganglioside FucGM1

The behaviour of a highly purified -l-fucosidase (E.C. 3.2.1.51) extracted from octopus hepatopancreas was studied with phospholipid vesicles composed of phosphatidylcholine (PC) and phosphatidylserine (PS) containing the fucosylated ganglioside FucGM1, a potential natural substrate of the enzyme. The substrate recognition and hydrolysis take place only with PS/FucGM1 mixtures via an association process of the enzyme with the vesicles at acidic pH; the enzyme rapidly and stably binds to PS vesicles but not to PC vesicles. The data suggest that only the PS-associated enzyme is able to hydrolyse FucGM1 embedded in the same bilayer. The enzyme association with FucGM1/PS vesicles is a prerequisite for ganglioside hydrolysis but is followed by irreversible enzyme inactivation.     

白粒济宁3号小麦品种的选育

用快中子照射红粒济宁3号小麦干种子,后代获得白粒植株,经选育而成白粒济宁3号。白粒济宁3号与红粒济宁3号比,除籽粒颜色差别外,籽粒蛋白含量显著高于红粒济宁3号,而落黄性、籽粒饱满度、千粒重、产量均略低于红粒济宁3号,该品种累计种植面积10余万亩。     

中国优质水果资源的分布与适宜生态环境

根据农业部在80年代两次组织评选出的全国189个优质水果产地的生态环境资料,用微型电子计算机系统建立数据库,统计分析柑桔、苹果和梨优质产品的构成比例、产区分布地域及其适宜的环境指标和主栽品种的生态适应性,为果树良种区域化栽培与选育提供依据。     

Comparison of the conserved region in the dnaA gene from three mollicute species

Abstract Polymerase chain reaction was carried out to amplify the conserved region (789 bp in the case of Mycoplasma capricolum ) of the dnaA gene (1350 bp in the case of M. capricolum ) of 15 representatives of the class Mollicutes using degenerate oligonucleotide primers. The dnaA gene fragments were amplified from M. mycoides subsp. capri, Spiroplasma apis and S. citri . The amino acid sequences deduced from the nucleotide sequences of the amplified fragments showed very low similarities to those of the corresponding regions of four walled bacteria. The values of similarity between any two of the three mollicute species were lower than those between any two of the four walled bacteria.     

一株C3形态多重耐药大肠杆菌噬菌体生物学特性和基因组分析

【目的】多重耐药菌的出现对公共卫生安全构成严重威胁,本研究分离多重耐药大肠杆菌噬菌体,研究其生物学特性和基因组特征,为耐药菌的噬菌体疗法提供理论依据。【方法】使用双层平板法从污水样本中分离纯化大肠杆菌噬菌体;磷钨酸染色后通过透射电镜观察形态;测定其宿主范围,测定温度和pH稳定性、一步生长曲线和体外抑菌效果等生物学特性;体内抑菌试验评估噬菌体对多重耐药大肠杆菌N1203-1Af感染的大蜡螟幼虫的保护作用;基于全基因组测序对其基因组特点进行分析。【结果】本研究分离共得到5株大肠杆菌噬菌体,分别命名为pEC-S163-2.1、pEC-S163-2.2、pEC-M1167-5Ar.1、pEC-m1291-2Dr.1和pEC-N1203-2Af.1;电镜结果显示噬菌体pEC-N1203-2Af.1属于短尾噬菌体中罕见的C3形态型,头部较长,长是宽的2–3倍;pEC-N1203-2Af.1可裂解受试15株大肠杆菌中的3株;感染10 min后进入指数增长期,–20-50℃、pH值为4.0–10.0的环境下均能够保持稳定活性;大蜡螟幼虫感染大肠杆菌N1203-2Af后噬菌体pEC-N1203-2Af....     

The effect of salinity on the reproduction of coastal submerged macrophytes in experimental communities

The effects of salinity on the reproduction of coastal submerged macrophyte species were studied on samples of communities from six seasonal marshes in two outdoor experiments performed in autumn and in spring. The submerged macrophyte communities were submitted to five different salinity levels (0, 1, 2, 4 and 6 g/1 Cl^?1). In a companion paper (Grillas, van Wijck & Bonis 1993) three groups of species were distinguished on the basis of their biomass production over the salinity range 0 to 6 g/1 Cl^?1: (1) glycophytes (non-salt-tolerant species), (2) salt-tolerant species and (3) halo-phytes. This part of the study describes the impact of salinity on the reproduction of the individual species during the two experiments. The species differ in their capacity to reproduce in the autumn; only Zannichelliapedunculata and Tolypella hispánica were able to produce fruits in that season. For all species reproduction was greater in spring and strongly correlated with biomass, except for Chara canescens. Differences in reproductive effort over the salinity range amplified the halophytic nature of Ruppia marítima and Chara canescens and the intolerance of Callitriche truncata and Chara contraria. For the other species, reproductive effort did not differ significantly over the salinity range. Regarding the effect of salinity on biomass and reproductive effort of individual species, there were large differences in the total weight of propagules produced at the community level and in the relative contribution of individual species. The resulting quantitative changes in the species composition of the seed bank could affect the structure of the communities by their effects on the establishment and survival of species populations.     

Structure determination of feline panleukopenia virus empty particles

Various crystal forms of the single-stranded DNA, feline panleukopenia virus (FPV), a parvovirus, have been grown of both full virions and empty particles. The structure of empty particles crystallized in an orthorhombic space group P2₁2₁2₁, with unit cell dimensions a = 380.1 Å, b = 379.3 Å, and c = 350.9 Å, has been determined to 3.3 Å resolution. The data were collected using oscillation photography with synchrotron radiation. The orientations of the empty capsids in the unit cell were determined using a self-rotation function and their positions were obtained with an R-factor search using canine parvovirus (CPV) as a model. Phases were then calculated, based on the CPV model, to 6.0 Å resolution and gradually extended to 3.3 Å resolution by molecular replacement electron density averaging. The resultant electron density was readily interpreted in terms of the known amino acid sequence. The structure is contrasted to that of CPV in terms of host range, neutralization by antibodies, hemagglutination properties, and binding of genomic DNA. © Wiley-Liss, Inc.     

血清SIRT1水平与射血分数保留的心力衰竭患者炎性因子、氧化应激的相关性分析及对预后的影响研究

摘要 目的：探讨血清去乙酰化酶1（SIRT1） 水平与射血分数保留的心力衰竭（HFpEF）患者炎性因子、氧化应激的相关性,分析SIRT1预测HFpEF患者预后的价值。方法：选择2019年10月至2021年6月青岛阜外心血管病医院收治的190例HFpEF患者为HFpEF组,92例心功能正常的健康体检志愿者为对照组。HFpEF患者出院后随访12个月,统计随访期间不良心血管事件发生情况,多因素Logistic回归分析HFpEF患者预后不良的影响因素。结果：HFpEF组血清SIRT1水平低于对照组（P＜0.05）,白细胞介素（IL）-6、肿瘤坏死因子-α（TNF-α）、C反应蛋白（CRP）、丙二醛（MDA）、晚期氧化蛋白产物（AOPP）水平高于对照组（P＜0.05）。HFpEF患者血清SIRT1水平与IL-6、TNF-α、CRP、MDA、AOPP呈负相关（r=-0.496、-0.502、-0.419、-0.533、-0.542,P＜0.05）。190例患者2例失访,余188例HFpEF患者中41例预后不良,147例预后良好。预后不良组美国纽约心脏病协会（NYHA）Ⅳ级比例、IL-6、TNF-α、CRP、MDA、AOPP、N末端B型利钠肽前体（NT-proBNP）水平、左室收缩末期内径（LVEDS）、左室舒张末期内径（LVEDD）、二尖瓣舒张早期血流峰值（E）与舒张晚期血流峰值（A）（E/A）高于预后良好组（P＜0.05）,血清SIRT1水平、左心室射血分数（LVEF）低于预后良好组（P＜0.05）。高IL-6、高MDA、高NT-proBNP是HFpEF患者预后不良的危险因素（P＜0.05）,SIRT1是HFpEF患者预后不良的保护因素（P＜0.05）。结论：HFpEF患者血清SIRT1水平降低,与HFpEF患者炎症反应、氧化应激以及预后不良的发生有关,可作为HFpEF患者预后评估的辅助指标。     

Complex structural effects of two hemispheric climatic oscillators on the regional spatio-temporal expansion of a threatened bird

Links between climatic conditions in the eastern equatorial Pacific and extratropical ecological processes remain unexplored. The analysis of a 20‐year time series of spatial and numeric dynamics of a threatened Mediterranean bird suggests, however, that such couplings can be remarkably complex. By providing a new ecological time‐series modelling approach, we were able to dissect the joint effects of the El Niño/Southern Oscillation (ENSO), the North Atlantic Oscillation (NAO), regional weather, population density and stochastic variability on the expansion dynamics of the White‐headed duck (Oxyura leococephala) in Spain. Our results suggest that the spatial and numeric dynamics of ducks between peak brood emergence and wintering were simultaneously affected by different climatic phenomena during different phases of their global cycles, involving time lags in the numeric dynamics. Strikingly, our results point to both the NAO and the ENSO as potentially major factors simultaneously forcing ecological processes in the Northern Hemisphere, and suggest a new pathway for non‐additive effects of climate in ecology.