世界柽麦蛾属支序生物地理学研究（鳞翅目： 麦蛾科）

基于对世界柽麦蛾属昆虫外部形态和外生殖器的形态学研究,选择了66个性状演变系列,通过PAUP*4b10软件对柽麦蛾属51种昆虫进行了支序系统学分析。分析结果认为heluanensis种团并不是一个单系群,柽麦蛾属被重新作了7个种团的划分。在支序系统学分析的基础上,柽麦蛾属昆虫的14个地理分布区域等级关系被重建,显示出古地中海地区复杂的历史,同时说明在该属分布格局中扩散事件客观存在。     

The O18 antigens (lipopolysaccharides) of Escherichia coli. Structural characterization of the O18A, O18A1, O18B and O18B1-specific polysaccharides.

The O-specific polysaccharide moieties (PS) of the O18A, O18A1, O18B, and O18B1 antigens (lipopolysaccharides, LPS) consist of L-rhamnose (Rha), N-acetyl-D-glucosamine, D-galactose, and D-glucose in different molar ratios. By using chemical fragmentation, methylation, as well as one- and two-dimensional NMR spectroscopy, the structures of these polysaccharides were found to be [formula: see text] In O18A-PS and O18A1-PS x = 2, whereas in O18B-PS and in O18B11-PS x = 3. In all four polysaccharides alpha-D-Galp (residue D) is substituted at O-3. This substituent L (residue E) is beta-D-GlcpNAc-(1 in O18A-PS and O18A1-PS and it is alpha-D-Glcp-(1 in O18B-PS and O18B1-PS. Whereas there is no further substituent on the main chain of the O18A and O18B polysaccharides, in O18A1-PS and O18B1-PS the alpha-D-GlcpNAc residue A is substituted with alpha-Glcp-(1 (residue F), which is linked to O-6 in O18A1-PS and to O-4 in O18B1-PS. These results show that the O18 antigen comprises a group of four related LPS (O18A and O18B, with their glucosylated forms O18A1 and O18B1). The results are discussed with respect to epitope definition and biochemical implications.     

Factors affecting gas transfer across the placenta and the oxygen supply to the fetus

The factors that affect placental gas exchange are reviewed, with particular reference to recent measurements of the effect of changes in one or more of these factors on O2 delivery to the fetus and on fetal O2 uptake. Fetal or maternal placental blood flows and blood O2 capacities can be altered by 50% without any major change occurring in fetal O2 uptake: umbilical venous O2 content and fetal O2 delivery fall, but the O2 consumption of the fetus is maintained by increasing the fractional extraction of O2 from the blood. There is evidence that the fetus can also cope with a reduction in blood O2 affinity resulting from replacement of fetal with maternal blood. The critical level of O2 delivery is about 0.6 mmol.min-1.kg-1 in the fetal sheep. When O2 delivery is reduced below this level, by decreasing maternal placental blood flow, raising or lowering fetal haematocrit, decreasing maternal O2 capacity, or decreasing fetal O2 affinity, fetal O2 uptake tends to fall. The resultant tissue hypoxia and inability to maintain oxidative metabolism is reflected in a lowering of arterial blood pH and base excess. Whilst the results of short-term experiments suggest that there exists a large reserve for placental O2 transfer and fetal O2 supply, there is evidence that fetal O2 uptake is more tightly linked to O2 delivery when the latter is reduced for a period of days or weeks. In the long term, restriction of the supply of O2 and nutrients leads to a reduced rate of fetal growth and a reprogramming of tissue development.     

努布拉鼠兔(Ochotona nubrica Thomas,1922)的分类订正

努布拉鼠兔(Ochotona nubrica)的分类地位迄今未能得到合理解决,曾被列为草原鼠兔(O.pusilla)、灰鼠兔(O.roylei)或藏鼠兔(O.thibetana)的同物异名。作者根据原始文献、地模标本及邻近地模产地的标本与有关的鼠兔种类进行对比研究,证实了努布拉鼠兔既不同于藏鼠兔,也不同于灰鼠兔,而是一个有效物种。     

Radiation sensitization of E. coli B/r by mixtures of oxygen and nitrous oxide

Oxygen (O2) sensitizes bacterial cells in at least two mechanistically different ways, depending on the specific O2 concentration present during irradiation. Based on previous work from this laboratory, it has been proposed that nitrous oxide (N2O) and low concentrations of O2 share a common mechanism for damage. This mechanism, involving the production of superoxide anion radicals (O2-), is different from that which causes damage at high O2 concentrations. Others, however, have presented evidence that N2O and O2 (usually tested only at high concentrations) act in different ways to sensitize bacterial cells. We have now measured the radiation sensitivity in mixtures of N2O and O2 to observe additivity patterns and to determine if these two agents have any common processes for sensitization. We found that some low O2 concentrations do not increase the response in N2O, although they can have significant sensitizing effects in N2. This lack of additivity is taken as evidence for a common mechanism of damage from N2O and low concentrations of O2. In contrast, damage from high concentrations of O2 is additive to the damage from N2O. The greatest sensitivity, observed with a gas mixture of about 15 per cent O2/85 per cent N2O, is equivalent to the response in 100 per cent N2 plus the maximum amount of damage O2 can cause plus the maximum amount of damage N2O can cause. This additivity is taken as evidence that N2O and high concentrations of O2 sensitize in different ways. Thus, O2 is known to sensitize these bacteria in at least two different ways; one of these is apparently also the way N2O sensitizes.     

A single amino acid substitution in a mannosyltransferase, WbdA, converts the Escherichia coli O9 polysaccharide into O9a: generation of a new O-serotype group

wbdA is a mannosyltransferase gene that is involved in synthesis of the Escherichia coli O9a polysaccharide, a mannose homopolymer with a repeating unit of 2-alphaMan-1,2-alphaMan-1,3-alphaMan-1, 3-alphaMan-1. The equivalent structural O polysaccharide in the E. coli O9 and Klebsiella O3 strains is 2-alphaMan-1,2-alphaMan-1, 2-alphaMan-1,3-alphaMan-1,3-alphaMan-1, with an excess of one mannose in the 1,2 linkage. We have cloned wbdA genes from these O9 and O3 strains and shown by genetic and functional studies that wbdA is the only gene determining the O-polysaccharide structure of O9 or O9a. Based on functional analysis of chimeric genes and site-directed mutagenesis, we showed that a single amino acid substitution, C55R, in WbdA of E. coli O9 converts the O9 polysaccharide into O9a. DNA sequencing revealed the substitution to be conserved in other E. coli O9a strains. The reverse substitution, R55C, in WbdA of E. coli O9a resulted in lipopolysaccharide synthesis showing no ladder profile instead of the conversion of O9a to O9. This suggests that more than one amino acid substitution in WbdA is required for conversion from O9a to O9.     

Interrelationship between oxygen consumption,superoxide anion and hydrogen peroxide formation in phagocytosing guinea pig polymorphonuclear leucocytes

The paper presents an experimental procedure for a simultaneous assay of oxygen consumption, O2- release and H2O2 accumulation at a very early stage of the respiratory burst that is induced by phagocytosis in guinea pig polymorphonuclear leucocytes. The main findings are as follows: (a) The oxygen consumption that is measurable does not correspond to all oxygen that is reduced. The relationship between the actual oxygen consumed and the amount that is reduced depends on the fate of the intermediate products O2- and H2O2. (b) O2- is measurable extracellularly by the reduction of cytochrome c. When cytochrome c oxidizes the extracellular O2-, molecular oxygen is formed. This fact is shown by a decrease of oxygen consumption. The molar ratio between the O2- detected and the oxygen given back is 1. (c) The amount of O2- released from the cells accounts for only a small part of oxygen actually reduced. (d) H2O2 is detectable only in the presence of NaN3. In this condition almost all oxygen consumed is recovered in the form of H2O2. The molar ratio O2/H2O2 is near unity. The amount of H2O2 derived from dismutation of O2- released is only an aliquot of the total H2O2 accumulated. Thus, most of H2O2 is derived from intracellular sources. (e) In the absence of inhibitors of H2O2 degrading reactions, no detectable accumulation of peroxide occurs. Under these conditions, the main part of H2O2 formed is degraded in almost equal amount by catalase and myeloperoxidase, while only a small aliquot is degraded by NaN3 insensitive reactions.     

Diarrheagenic Escherichia coli categories among the traditional enteropathogenic E. coli O serogroups--a review

The so called enteropathogenic Escherichia coli (EPEC) O serogroups include typical and atypical EPEC, enterohaemorrragic E. coli, enterotoxigenic E. coli, and enteroaggregative E. coli. The aim of this article is to review the composition of each O serogroup and the major serotypes, clones, and additional virulence characteristics of each of these diarrheagenic categories. Their adherence patterns and genetic relationships are also presented. The review is based on the study of 805 strains of serogroups O26, O55, O86, O111, O114, O119, O125, O126, O1127, O128, and O142 most of which isolated in Sao Paulo from children with diarrhea between 1970 and 1990. Since some O serogroups include more than one diarrheagenic category O serogrouping only should be abandoned as a diagnostic method. However serotyping is a reliable method for those serotypes that correspond to clones.     

新疆棘豆属棘豆组的修订

通过对大量标本和文献的研究,并结合野外居群的观察分析,澄清了《中国植物志》棘豆组中存在的分类学问题,对新疆棘豆属棘豆组植物的分类进行修订,确认产于新疆的棘豆属棘豆组植物8种、1变型,并重新编制了新疆棘豆属棘豆组的分种检索表,以及各种的分类学处理及地理分布.研究结果表明:少花棘豆归并在宽瓣棘豆中,其中少花棘豆为新异名;冰河棘豆应改为球花棘豆;冰川棘豆的学名更正为Oxytropis proboscidea;将黑萼棘豆并入长茎棘豆组中.此外,棘豆组增加了3个类群:等瓣棘豆、伊朗棘豆和奇台棘豆,其中等瓣棘豆和伊朗棘豆为新疆新记录种,白花球花棘豆为新变型.     

Orthaea (Ericaceae-Vaccinieae): New species and redefinition of the genus

A historical review of Orthaea is provided and the present generic concept is amplified to include Empedoclesia and Lysiclesia . A key to the 31 recognized species is given. Orthaea paniculata, O. glandulifera, O. oedipus , and O. coriacea are described as new. New combinations are Orthaea caudata, O. minor, O. panamensis, O. brachysiphon , and O. stipitata .     

lac repressor forms stable loops in vitro with supercoiled wild-type lac DNA containing all three natural lac operators

We have analyzed protein-DNA complexes formed between lac repressor and linear or differently supercoiled lac DNA (802 or 816 base-pairs in length), which carry all three natural lac operators (O1, O2 and O3) in their wild-type sequence context and spacing and compared them with constructs that contain specifically mutated "pseudo-operators" O2 or O3. We used gel retardation assays to identify the nature of the complexes according to their characteristic electrophoretic mobility and dissociation rate measurements to determine their stability. With linear DNA we found only indirect evidence for loop formation between O1 and O2. In covalently closed DNA minicircles the formation of a loop between O1 and O2 could be demonstrated by the observation that O1-O2 containing DNA with low negative supercoiling (sigma = -0.013 and less) is constricted by binding of lac repressor, resulting in an increased electrophoretic mobility. At elevated negative supercoiling (sigma = -0.025, -0.037, -0.05) O1-O2 containing DNA complexed with lac repressor migrates significantly slower than the corresponding O1-DNA, indicating loop formation. The dissociation of lac repressor-operator complexes is decreased with increasing negative supercoiling for all tested operator combinations of O1, O2 and O3. However, in the presence of at least two natural lac operators on the same DNA minicircle the enhancement of stability is particularly large. This indicates that a DNA loop is formed between these two lac operators, O1 and O2 as well as O1 and O3, since negative supercoiling is known specifically to promote the formation of looped structures. Additionally, we observe a dependence of dissociation rate on the spatial alignment of the operators as a result of changing helical periodicity in differently supercoiled DNA and consider this to be further evidence for loop formation between O1 and O2 as well as O1 and O3.     

Genetic relationships among Orobanche species as revealed by RAPD analysis

RAPD markers were used to study variation among 20 taxa in the genus OROBANCHE: O. alba, O. amethystea, O. arenaria, O. ballotae, O. cernua, O. clausonis, O. cumana, O. crenata, O. densiflora, O. foetida, O. foetida var. broteri, O. gracilis, O. haenseleri, O. hederae, O. latisquama, O. mutelii, O. nana, O. ramosa, O. rapum-genistae and O. santolinae. A total of 202 amplification products generated with five arbitrary RAPD primers was obtained and species-specific markers were identified. The estimated Jaccard's differences between the species varied between 0 and 0.864. The pattern of interspecific variation obtained is in general agreement with previous taxonomic studies based on morphology, and the partition into two different sections (Trionychon and Orobanche) is generally clear. However, the position in the dendrogram of O. clausonis did not fit this classification since it clustered with members of section TRIONYCHON: Within this section, O. arenaria was relatively isolated from the other members of the section: O. mutelii, O. nana and O. ramosa. Within section Orobanche, all O. ramosa populations showed a similar amplification pattern, whereas differences among O. crenata populations growing on different hosts were found. Orobanche foetida and O. densiflora clustered together, supporting the morphological and cytological similarities and the host preferences of these species.     

Molecular systematics of five Onchocerca species (Nematoda: Filarioidea) including the human parasite, O. volvulus, suggest sympatric speciation

The genus Onchocerca (Nematoda: Filarioidea) consists of parasites of ungulate mammals with the exception of O. volvulus, which is a human parasite. The relationship between O. volvulus, O. ochengi and O. gibsoni remains unresolved. Based on morphology of the microfilariae and infective larvae, vector transmission and geographical distribution, O. ochengi and O. volvulus have been placed as sister species. Nevertheless, the cuticle morphology and chromosomal data (O. volvulus and O. gibsoni have n=4 while O. ochengi is n=5) suggest that O. gibsoni could be more closely related to O. volvulus than O. ochengi. Sequences from the 12S rRNA, 16S rRNA and ND5 mitochondrial genes have been used to reconstruct the phylogeny of five Onchocerca species including O. volvulus. Analyses with maximum likelihood and maximum parsimony showed that O. ochengi is the sister species of O. volvulus, in accordance with the classification based on morphology and geographical location. The separate specific status of the species O. gutturosa and O. lienalis was supported, although their phylogenetic relationship was not well resolved. The analyses indicated that the basal species was O. gibsoni, a South-East Asian and Australasian species, but this result was not statistically significant. The possible involvement of sympatric speciation in the evolution of this group of parasites is discussed.     

Cloning and sequence of a region encoding a surface polysaccharide of Vibrio cholerae O139 and characterization of the insertion site in the chromosome of Vibrio cholerae O1

Vibrio cholerae serogroup O139 Bengal is the first documented serogroup other than O1 to cause epidemic cholera. The O139 Bengal strains are very similar to V. cholerae serogroup O1 biotype El Tor strains. The major differences between the two serogroups are that O139 Bengal contains a distinct O antigen and produces a polysaccharide capsule. We previously described three Tn phoA mutants of O139 strain AI1837 which abolish both O antigen and capsule production. These Tn phoA insertions were mapped to a 21.5 kb Eco RI fragment of the O139 chromosome. We describe here the cloning and mapping of this 21.5 kb Eco RI fragment and it was shown to complement each of the mutants in trans to produce O antigen and capsule. The Eco RI fragment contains 13 kb of DNA that is specific to O139 and 8.5 kb of DNA that is common to O1 and O139. Sequence analysis of the 13 kb of O139-specific DNA revealed that it contains 11 open reading frames all of which are transcribed in the same direction. Eight of the 11 open reading frames are homologous to sugar biosynthesis genes from other organisms. Using extended polymerase chain reactions, we show that the extent of the DNA region in O139 that is not present in O1 is approximately 35kb. The site of insertion of this O139-specific DNA in the O1 chromosome was mapped to the rfb _O1 region. We also demonstrate that O139 Bengal strain AI1837 contains a deletion of 22 kb that in serogroup O1 strains contains the rfb region. Therefore, O139 Bengal probably arose from an O1 strain that had undergone genetic rearrangements including deletion of the O1 rfb region and acquisition of a 35 kb region of DNA which encodes O139 surface polysaccharide.     

O2- activates leaf injury, ethylene and salicylic acid synthesis, and the expression of O3-induced genes in O3-exposed tobacco

O3 is the major component of photochemical oxidants and gives rise to visible injuries on plant leaves. In O3-exposed plants, O2- is produced before the formation of the injury, but the role that O2- plays in plant response to 03 exposure is still unknown. To clarify its role, we observed the behavior of plants during O3 exposure after pretreatment with tiron, which is an O2- scavenger. When tiron-pretreated tobacco cv. Bel W3 was exposed to O3, leaf damage was attenuated. In O3-exposed tobacco, tiron inhibited increases in the levels of ethylene and salicylic acid, which promote leaf injury. Tiron pretreatment also suppressed increases in the expression of O3-induced genes. These results suggest that O2- is involved in many plant responses induced by O3 exposure. Bel B, a tobacco cultivar that is genetically related to Bel W3, is reported to be more resistant to O3 than Bel W3, but the reason for this difference is unclear. We investigated the differences between the responses of Bel B and tiron-pretreated Bel W3 to O3 exposure, and we discuss the reasons for the resistance to O3 by comparing the phenotype of Bel B with that of tiron-pretreated Bel W3.     

中国四川和宁夏巨须隐翅虫亚属的新种和新纪录(鞘翅目,隐翅虫科,巨须隐翅虫亚科)

报道中国四川和宁夏巨须隐翅虫属Oxyporus Fablicius,巨须隐翅虫亚属subgenus Oxyporus12个种.记述了 4新种,黄缘巨须隐翅虫Oxyporus aureomarginatus,北川巨须隐翅虫O.beichuanus,海螺沟巨须隐翅虫O.hailuogou和肩斑巨须隐翅虫O.humerosus.简述了1新亚种,扬氏高山巨须隐翅虫O.altus yangae的特征.首次记述了黑胸巨须隐翅虫O.nigricollis Zheng的雄性.提供了高山巨须隐翅虫Oxyporus altus Huang,Zhao et Li,仙台巨须隐翅虫O.germanus Sharp,黑腹蕈巨须隐翅虫O.humerocroceus Huang,Zhao et Li,溪巨须隐翅虫O.riparius Zheng,橘红巨须隐翅虫O.rufus(Linné),中华巨须隐翅虫O.sinicus Huang,Zhao et Li,和横沟巨须隐翅虫O.transversesrlcatus Bernhauer的新分布.所有研究标本都附有彩色整体外形图,新种和新的雄性配有特征图.     

Morphological studies of Asian rice and its related wild species and the recognition of a new Australian taxon

In order to clarify the taxonomy and the interrelationships among Asiatic cultivated rice, Oryza sativa , and its related wild species ( O. rufipogon, O. nivara and O . barthii ), 41 morphological characters were examined. Numerical taxonomic methods were used to analyse the data and to illustrate species relationships.
Distinctive differences among the materials studied suggest the retention of O. rufipogoon, O. nivara and O . sativa as three distinct species. The origin of O. sativa from O. nivara through domestication is discussed. An annual wild taxon from Australia, which had been classified as a form of O. nivara , is shown to be distinct from typical O. nivnra and is raised to specific rank. This species has been named O. meridionalis Ng.     

Reaction of diazoalkanes with 1-substituted 2, 4-dioxopyrimidines. Formation of O2, N-3 and O4-alkyl products.

In non-aqueous solution, diazomethane and diazoethane react with the O2, O4 and N-3 sites of uridine, thymidine, 1-methyluracil and 1-methylthymine. Diazoethane has a higher affinity for alkylating oxygens than does diazomethane. The relative ratio of O2:O4:N-3 methyl products is 1:2:16 and of ethyl products the ratio is 1:1:2. When the diazoethane reaction is performed in neutral buffered solution, the same proportion of O2:O4:N-3 ethyl products is found, but the extent of reaction is very low. O2-alkylation greatly labilizes the glycosidic bond of thymidine and uridine toward acid hydrolysis. All O2 and O4 alkyl 1-substituted 2,4-dioxopyrimidines are dealkylated in weak acid but the O2 alkyl group is the more stable.     

Phylogeny of the genus Omphalotus based on nuclear ribosomal DNA-sequences

The evolutionary history of the genus Omphalotus was inferred from DNA sequences of the ITS1-5.8S-ITS2 rDNA region. We analyzed 32 collections from different geographical areas: O. olearius (Europe), O. illudens (Europe, North America), O. subilludens (North America), O. olivascens var. olivascens (North America) and var. indigo (Mexico), O. mexicanus (Middle America), O. nidiformis (Australia), and O. japonicus (Japan). Phylogenetic analysis was performed declaring Nothopanus eugrammus as outgroup. Our analyses show that the genus Omphalotus is split into two major clades, the first consisting of O. illudens and O. mexicanus and the second comprising O. olearius, O. olivascens, O. japonicus, O. nidiformis and O. subilludens. Moreover, the often discussed synonymy of O. illudens and O. olearius is rejected. Omphalotus japonicus, a species formerly placed in the genus Lampteromyces Sing. for morphological reasons, clustered as the sister group of O. olearius.     

Tissue oxygenation in septic respiratory failure

The relationships between tissue oxygenation and the different haemodynamic and respiratory parameters were studied in 20 patients with ARDS of septic origin. Good regressions were found between O2 delivery and cardiac index (r = 0.8507), O2 delivery and systemic vascular resistance (r = -0.7051), O2 extraction ratio and mixed venous O2 saturation (r = 0.8978), O2 consumption and cardiac index (r = 0.6593), O2 consumption and systemic vascular resistance (r = -0.6548), and O2 consumption and mixed venous O2 saturation (r = -0.7068). The correlation among the parameters of tissue oxygenation was more expressed between O2 extraction ratio and O2 consumption (r = 0.7285), than between O2 delivery and O2 consumption (r = 0.6095). A better result was achieved by multiple regression analysis, where the multiple r was 0.9748 between O2 consumption and O2 delivery + O2 extraction ratio, whereas the other variables did not increase the multiple r significantly. These regressions also proved the relationship following from the Fick equation, that is O2 consumption is the result of O2 delivery multiplied with the O2 extraction ratio.