河北小五台山叶生丝孢菌

小五台山自然保护区位于河北省西部,为河北省第一高峰。变化悬殊的地形,使其由低谷到亚高山草甸呈明显独特的垂直植被类型分布带,山势陡峻,谷路隘险,具有华北地区罕见的森林植被及丰富的植物资源。狭谷陡峰,葳蒐险奇的地形地貌,又形成了多变的气候特征,因此蕴藏着相当丰富的真菌资源。作者1990年8月在该地区考察期间,共采集涉及林木、农作物、花卉、蔬菜等植物病害标本240份。本文报道小五台山的丝孢菌(Hyphomycetes)14属40种,其中有二个新种:(木来)木菌绒孢(Mycovellosiella coni Y.L.Guo, sp. nov.),五味子色链隔孢(Phaeoramularia schisandrae Y.L. Guo, sp. nov.)和7个中国新记录种:沼泽尾孢(Cercospora paludicola Speg.),白面子菌绒孢[Mycovellosiella ariae(Fuckel) U. Braun],薯蓣菌绒孢[Mycovellosiella dioscorae(Vassiljevski) Pons & Sutton],当归柱隔孢(Ramularia angelicae v. Hohnel),白芷柱隔孢[Ramularia heraclei(Oud.)Sacc.),莴苣柱隔孢(Ramularia lactucosa Lamb. & Fautr.)和虎耳草柱隔孢(Ramularia saxifragae Syd.)。(木来)来木菌绒孢(Mycovellosiella coni Y.L. Guo, sp. nov.)生于山茱萸科(Cornaceae)华尔特氏掠子木(Cornus walteri Wanger.)叶上。子实体生于叶背面。次生菌丝体表生。无子座。分生孢子梗1-3根从气孔伸出或作为侧枝单生于表生菌丝上,近无色,分枝,曲膝状,1-2个隔膜,5.0-50.0 × 2.5-4.0 μm。分生孢子圆柱形,无色,链生并具枝链,0-4个隔膜,6.5-45.0 × 2.0-4.0 μm。在山茱萸科尚无菌绒孢属的报道,且该菌与已报道的尾孢属菌形态特征也不同,故定为新种。五味子色链隔孢(Phaeoramularia schisandrae Y.L. Guo, sp. nov.)生于五味子科(Schisandraceae)五味子[Schisandra chinensis (Tunz.) Baill.]叶上,子实体生于叶背面。菌丝体内生。具子座。分生孢子梗紧密簇生,浅青黄褐色,不分枝,曲膝状,1-5个隔膜,20.0-75.0 (-95.0) × 4.0-5.0 μm。分生孢子圆柱形,近无色,链生并具枝链,1-4个隔膜,15.0-40.0 × 3.0-4.0 μm。五味子科既无尾孢菌属也无色链隔孢属的报道。文中为新种提供了拉丁文简介、描述和图,新记录种进行了简要描述。研究的标本保藏在中国科学院微生物研究所真菌标本室(HMAS)。     

In vivo anti inflammatory effects of the M20 IL-1 Inhibitor: I. Effects on acute inflammatory parameters

Previous studies have described an IL-1 Inhibitor produced by a myelomonocytic line developed in our laboratory (Eur J Immunol 1986; 16: 1449). This IL-1 Inhibitor was secreted by the M20 line constitutively in addition to IL-1, from which it could be separated. We have recently shown that the M20 IL-1 Inhibitor is distinct from the IL-1ra.In vitro this factor inhibited IL-1 induced proliferative responses as well as PGE₂ secretion by IL-1 induced fibroblasts. We also showed for the first time (Lymphokine Research 1988; 7(3): 268) that an IL-1 inhibitor can reduce IL-1 induced inflammatory effects. This study describes the specific effect of the M20 IL-1 Inhibitor on IL-1 induced parameters of inflammation: fever, leukocytosis and local foot pad swelling or lymph node enlargement. Purified preparations of the IL-1 Inhibitor, when injected together with IL-1, or before the IL-1, reduced fever, leukocytosis, foot pad swelling and lymph node enlargement caused by IL-1. Similar responses were obtained by injection of IL-6 or TNF, but were unaffected by the IL-1 Inhibitor, when injected together.These results indicate that the M20 IL-1 Inhibitor acts specifically on IL-1 induced responsesin vivo. The potential importance of this factor as an anti-inflammatory and immune regulatory factor, is supported by the findings of this study.Abbreviations IL-1 Interleukin 1 - IL-6 Interleukin 6 - IL-1ra Interleukin 1 receptor antagonist - TNF tumor necrosis factor     

Photo-induction of electrical current with the cyanobacteriumAgmenellum quadruplicatum PR-6

We investigated the possibility of eliciting a measurable photoinduced electrical current from the cyanobacteriumAgmenellum quadruplicatum PR-6 (Synechococcus PCC 7002). This proved virtually impossible for intact cells. However, treated PR-6 cells fixed in an alginate matrix on tin oxide as the active electrode in a three electrode electrochemical cell gave rise to a significant light response. Cell treatments involving toluene, chloroform or detergents were effective and gave current responses up to 250 nA. Drying the cyanobacterial matrix increased the current yield at least fifty-fold. These effects were observed for light wavelengths > 650 nm and were not influenced by inhibitors or enhancers of photosynthesis nor by sustained argon bubbling of the electrolyte.French pressure cell lysates facilitated distinction between two light induced current components. Lysates prepared without CaCl₂ gave current induction kinetics that were indistinguishable from those on chemically treated cells i.e. slowly rising to a stable maximum in 10–15 min. When CaCl₂ was present during lysis, a rapidly induced (<1 s) unstable component was observed. Toluenization of PR-6 either prior to or post lysing abolished the CaCl₂ related effect. CaCl₂ had no effect on current induction in strain PR-6008, which lacked the and subunits of phycocyanin and exhibited slow current induction kinetics.The observed effects are interpreted as responses of components of the photosystems of PR-6 rather than in terms of an integrated photosynthetic process.     

EFFECTS OF SUBSTRATE RELIEF ON THE DISTRIBUTION OF PERIPHYTON IN LABORATORY STREAMS. II. INTERACTIONS WITH IRRADIANCE1

Laboratory streams were used in a 42-day experiment designed to investigate how the spatial and temporal distribution of lotic periphyton created by current flow over cobble-size substrates is a affected by irradiance. The streams contained 22.5 × 22.5 × 4 cm substrate blocks and were exposed to either 385, 90 or 20 μE·m^?2·s^?1. We monitored periphyton succession in fast current regimes on top of blocks and in slower current regimes on surfaces recessed between blocks. The absolute differences in AFDW algal biomass between top and recessed substrates were significantly affected by irradiance and time. At the end of the experiment, biomass in streams exposed to 385 μE·m^?2·s^?1. was approximately 2 and 8 times greater than in streams exposed to 90 and 20 μE·m^?2·s^?1, respectively. Differences in biomass were greater between irradiance levels than between top and recessed substrates within an irradiance level. Irradiance also had a greater effect than current regime on the taxonomic composition of assemblages. Oscillatoria agardhii Gomont and Navicula minima Grun. characterized assemblages at 20 μE·m^?2·s^?1, whereas Fragilaria vaucheriae (Kütz.), Nitzschia oregona Sov., Navicula arvensis Hust. and Stigeoclonium tenue (Ag.) Kütz. were more abundant at the two higher irradiances. Detrended correspondence analysis indicated that the rate of succession was relatively high for assemblages at high irradiance and in the slow current regimes between blocks. The results suggested that in natural streams, periphyton patches produced by large differences in irradiance should have a greater effect on periphyton heterogeneity than substrate-induced patches. Moreover, the heterogeneity of algal patches produced by hydrologic differences over a substrate is constrained by irradiance level.     

培养大鼠颈上神经节单烟碱受体通道及突触电流的膜片钳研究

在培养１─２周的大鼠颈上神经节交感神经元标本上,用膜片钳技术记录了单烟碱受体通道电流及胆碱能突触电流,并分析了它们之间的关系。单烟碱受体通道至少有三种亚导状态,即１５ｐＳ,２７ｐＳ,３８ｐＳ,其中以２７ｐＳ最常见。通道有两种开放模式,即单个短促开放与长串开放。对应的平均开放时间分别为τ＿１＝１．７１ｍｓ,τ＿２＝１２．２４ｍｓ。对自发突触电流的分析表明,其下降相的衰减时间常数（τ＝１５．７±１ｍｓ）与上述长串开放的持续时间相当,提示在突触传递过程中,突触前末梢释放的ＡＣｈ引起了突触后神经元烟碱受体通道的长串开放。     

湿度和温度对酰化紫膜LB膜M衰减的影响

用闪光动力学光谱仪测量了酰化紫膜ＬＢ膜中Ｍ衰减速率的变化。酰化紫膜ＬＢ膜的衰减无论是悬浮液状态,还是ＬＢ膜中,均比未修饰的要慢。在温度为２０℃时,酰化紫膜ＬＢ随着相对湿度的增加,Ｍ衰减加快。在相对湿度较低时（ＲＨ３４—７５％）,变化较平缓,即Ｍ的衰减加快不明显;在相对湿度较高时（ＲＨ８４—９５％）,Ｍ衰减明显加快。温度的变化则随相对湿度不同而不同。相对湿度较低时,随着温度的升高,Ｍ衰减加快;相对湿度较高时,Ｍ衰减反而减慢。酰化紫膜悬浮液的Ｍ衰减随着温度的升高而明显加快．这说明酰化紫膜ＬＢ膜中ＢＲ水合程度可能是直接影响Ｍ衰减的因素之一。     

Cloning single-stranded DNA

DNA sequence and expression analyses have greatly benefited from using M13 and pUC derived cloning vectors and their polycloning sites. A chronology of the original concepts and experiments is reviewed.     

Cholinomimetics Increase Glutamate Outflow via an Action on the Corticostriatal Pathway: Implications for Alzheimer's Disease

Abstract: Physostigmine, the acetylcholinesterase inhibitor (0.3 mg/kg, i.m.), increased extracellular glutamate but not aspartate concentrations in the striatum of anaesthetised rats, determined using microdialysis and HPLC. The rise was both tetrodotoxin and calcium dependent. In contrast, neither physostigmine (10 µ M ) added to the perfusion fluid nor vehicle (injected intramuscularly) affected amino acid concentrations. To obtain evidence that the action of acetylcholine was to modulate positively cortical pyramidal neurone activity via the M₁ receptor, the selective M₁ agonist PD 142505-0028 (10 µ M ) was topically applied to the frontal cortex. Like physostigmine, PD 142505-0028 rapidly increased glutamate but not aspartate concentrations in the striatum. Moreover, the effect of intramuscular physostigmine was blocked by a topically applied M₁ antagonist. These new data add to our hypothesis that cholinomimetics increase pyramidal neurone function.     

Extracellular pH modulates the Ca2+ current activated by depletion of intracellular Ca2+ stores in human macrophages

Intracellular Ca²⁺ (Ca_i) signaling following the binding of surface receptors activates a Ca²⁺ permeable plasma membrane conductance which has been shown to be associated with store depletion in a number of cell types. We examined the activation of this conductance in human monocyte-derived macrophages (HMDMs) using whole-cell voltage-clamp techniques coupled with fura-2 microfluorimetry and characterized the importance of external pH (pH_o) as a modulator of current amplitude. Current activation was observed following experimental maneuvers designed to deplete intracellular Ca²⁺-stores including: (i) dialysis of the cell with 100 m inositol 1,4,5-triphosphate (IP₃), (ii) intracellular dialysis with high concentrations of the Ca²⁺ buffers EGTA and BAPTA, or (iii) exposure of the cell to the Ca²⁺-ATPase inhibitor thapsigargin (1 m). Currents associated with store depletion were inwardly rectifying with kinetics, inactivation, and selectivity that appeared similar irrespective of the mode of activation. Currents were Ca²⁺ selective with a selectivity sequence of Ca²⁺ > Sr²⁺ Mg²⁺ = Mn²⁺ = Ni²⁺. The Ca²⁺ influx current was modulated by changes in pH_o; modulation was not produced as a consequence of changes in internal pH (pH_i). External acidification led to a reversible reduction in current amplitude with a pKa at pH 8.2. Changes in pH_o alone failed to induce current activation. These observations are consistent with a scheme by which changes in pH_o, as would be encountered by macrophages at sites of inflammation, could change the time course and magnitude of the Ca_i transient associated with receptor activation by regulating the influx of Ca²⁺ ions.The authors wish to gratefully acknowledge the expert technical assistance of Weiwen Xie without whom the study could not have been completed. This work was supported by National Institutes of Health GM36823.     

Intra- and Interpopulation Genome Variation In Meloidogyne arenaria

The genetic heterogeneity of two M. arenaria race 2 populations (designated Pelion and Govan) was examined using RFLP analysis of 12 clonal lines established from single egg masses (six distinct clonal lines from each population). These populations are essentially identical by traditional biochemical and race identification schemes; however, the Govan population is more aggressive than the Pelion population, producing larger galls and exhibiting greater reproductive capabilities on many soybean cultivars and experimental accessions. Variation at the genomic DNA level was examined using probes representative of expressed DNA sequences present in the eukaryotic genome. Ribosomal DNA, interspersed repeated sequences, and cDNA probes were tested for detection of polymorphism within and between single egg mass lines of each population. Cloned cDNAs and ribosomal intergenic spacer sequences detect polymorphism both within and between populations, demonstrating the usefulness of these sequence classes for molecular genetic analysis of population structure and genome evolution.